Portable ultrasound tubular transducer, that generates cavitation in liquids, of the type that comprises at least one electromechanical transducer assembly, characterized in that at least one electromechanical transducer assembly is embedded inside a metallic pipe, and comprises one or more piezoelectric crystals which are power-fed from the exterior, and which are coupled to a first mass embedded at one end of said metallic pipe and to a second mass disposed in the interior of such metallic pipe and linked with said first mass, said portable tubular transducer being provided with a subjection medium.

The invention relates to an ultrasound portable tubular transducer that generates cavitation in liquids, in which an electromechanical transducer, is solderless embedded, at one end and inside a metallic pipe. The transducer resonates at the resonant frequency of the pipe. The transducer""s other end has embedded either a countermass or other electromechanical transducer of identical characteristics and identical assemblage and with connecting cables running through the countermass or through a node of minimal vibration of the metallic pipe, where a smaller diameter pipe is fixed for its support, which is particularly apt to perform tasks that require ultrasound cavitation in liquids.
The transducer of the present invention has several uses that are advantageous. One such use is the cleaning of different types of pieces or parts without requiring the use of stainless steel containers or any other specific-form container. Another such use is the cleaning of different pieces or parts using different cleaning liquids without requiring the use of several cleaning machines. Another use is the cleaning of different pieces or parts taking advantage of using existing recipients such as vats, sinks, buckets, boxes used in surgery, as well as glass containers. Another use is the cleaning of receptacles filled with liquids such as tanks or sinks. A further use is the cleaning of volumes that can be filled with liquids such as dosing apparatuses, mixing or kneading machines, as well as the interior part of pipes.
At present, the ultrasonic cleaning of different pieces is performed in a liquid medium contained inside stainless steel vats with transducers glued to their exteriors. These transducers being of the Langevin type which make them vibrate, thus provoking a phenomenon called cavitation. This cavitation causes an effect analogous to a microscopic brushing to the visible as well as the non-visible pieces or parts.
The size of the vat to be used and the required ultrasonic power are determined by the size or by the quantity of the pieces to be cleaned.
This is a costly solution because this method requires stainless steel vats of different sizes which have low efficiency and are very noisy. When the use of several transducers to make vibrate the vats and the vats to make vibrate the liquid are required, too much energy is lost. In addition, detuning of the transducers among themselves generates intense noise which is not only uncomfortable but harmful to the health of the user. This solution is of limited reliability because the transducers are glued and may become unglued. In addition, this method is not very flexible because the washing can only take place inside the machine.
Another type of solution is the use of submergible transducers. This method typically consists of using several transducers of the Langevin type which are glued inside a hermetic stainless steel box. In this method tubular-type transducers can also be used. These transducers are of greater efficiency.
Tubular transducers permit greater freedom because the vat does not have to be a stainless steel one, they generate the ultrasound in homogenous form, occupy little space, and the transducer or transducers to be used may be determined by the power density needed.
When each tubular transducer is excited by means of a self-syntony generator and when no vibration from the walls of the vat takes place as the working principle, the noise is reduced to a great extent and the efficiency is increased significantly.
These transducers are placed in a fixed manner to the vat. The user will be searching their best position and will work with the transducers being totally submerged in order to dissipate the heat in the liquid. This means these transducers have not been thought of for portable use.
Transducers of this type are found in U.S. Pat. No. 5,200,666 to Walter et al., and in U.S. Pat. No. 6,111,337 to Christensen.
In order to make up for all the above-mentioned disadvantages, in the present invention, the electromechanical transducer or transducers are coupled at the inside end of the metallic pipe that resonates and that serves, at the same time, as container, and that is supported by a handling means such as a pipe with a diameter smaller than that of the resonant metallic pipe and that is located in the center of the resonant metallic pipe or in the countermass embedded at one end of the metallic pipe.
In the countermass configuration, where the electromechanical transducer is located inside one of the ends of the metallic pipe, a greater ultrasound intensity is radiated at this end. This is of particular interest to a portable application, since this allows this end to face the dirtiest parts of the piece or part to be washed.
In addition, this configuration allows for better dissipation of the heat than in other known tubular transducers, because the surface in contact with the liquid is greater.
Since the countermass presents minimum vibration and the coupling to the smaller diameter pipe supporting it is weak, the vibrations are not transmitted and do not generate discomfort to the user while he sustains it with the hand.
In the symmetrical configuration where two electromechanical transducers are equal at the ends, the difference in radiation between the ends and the pipe is not too great, as this receives twice the power. This is desirable as the objective is to place the pipe in front of the piece or part to be cleaned. Also the heat is better dissipated in the liquid because the tubular transducer has more surface in contact with same.
Since the center of the pipe has a minimum vibration and coupling to the smaller diameter pipe that supports it is weak, the vibrations are not transmitted and therefore do not generate disturbances to the user while he sustains it with the hand or to any mechanism of support.
In both cases an abrupt change of impedance is produced when the transducers are taken out of the liquid, wherefrom if one were to operate the transducers in a continuous manner, taking the tubular transducer out of one vat and transferring it to another vat without damaging the tubular transducer, it is necessary to constantly sense the impedance by means of reading, in real time, the output tension and the current output from the generator in such manner that, when the impedance goes to below an established value Z min=V output/I output, at this moment, the energy coming from the generator must be interrupted. This energy can then be reestablished in a continuous manner only when the impedance returns to its normal level.
This way, overheating of the electromechanical transducer is avoided. At the same time, it allows for the taking out and for the placing in of the portable transducer of the invention in different vats and liquids at will, and without having to shut off the generator every time, thus avoiding operational mistakes.
The portable characteristic amplifies enormously the amount of possible applications and extends the use of ultrasound.
It is worth noting that with ultrasound it is possible to clean with biodegradable liquids that are not contaminant. This means that as its use increases it improves both the conditions for the environment as well as the conditions for the users.
For example, it allows the cleaning of different pieces with different liquids in vats with different shapes and different materials using the same transducer and passing said transducer from one vat to another.
It also allows for the use of an existing sink, such as a kitchen sink, to clean silverware, dishes, or any other item desired.
The tubular transducer may also be mounted at an end of a flexible pipe where the energy-conducting cables go, which configuration permits introduction of the transducer into clogged pipes and be able to get the clogging material or rust out, thereby increasing their useful lives. This being an innovative application that avoids costly changes of pipes.
Because of its portability the transducer of the invention can also be placed or introduced inside a cavity such as a small lattice, a can of paint, a deposit, or it may be introduced in a throw-away container.
An additional advantage is the fact that the electromechanical transducer is housed inside a pipe that radiates the ultrasound, this acts as a container making it much more compact, lighter, with less amount of pieces than those used by other tubular transducers and consequently much more economic.
Another additional advantage of this innovating configuration is that the tubular transducer is assembled by means of the embedding, with pressure, of its pieces, rather than by welding, or turning on the lathe of coupling acoustic transformers, thus reducing the manufacturing processes, the need for special care due to overheating in the welding process, the quality control of the welding process, thus eliminating a possible rupture zone and the origin of its greatest cost.
Another advantage of the embedding with pressure of its constitutive pieces is that, since the cavitation effect tends to concentrate in the discontinuities, for example, and particularly in the welding process, not having any welded parts, the major cause for greater wear of the material disappears, and a longer useful life for the transducer is therefore attained.
If, instead of having an assemblage for manual or portable use, a fixed mounting is used in a wall or at the bottom of a container, like other tubular transducers, this can be obtained with the advantage of its smaller size and lower cost.
According to the frequency of its use, the power used, and the application desired, the transducer of the invention can be manufactured with different lengths and diameters.
The tubular transducer, object of the present invention, that has two electromechanical transducer assemblies is used in applications that require more power. In addition, its manufacturing characteristics permit the economic use of titanium, a noble metal but an expensive one, since it takes a minimum amount of this metal, and, due to its configuration, it does not require complex mechanical processes or welding. This way it is possible to obtain a much more resistant and economical transducer than those now existing.
Other uses or applications of the transducer of the present invention are the treatment of waters, the degasification of liquids, the homogenization of mixtures, and the dilution in solvents, in which a compact and economical transducer, like this one, increases its usage possibilities.
The object of the present invention is then an ultrasound portable tubular transducer to generate the cavitation in liquids, of the type comprising at least a system of electromechanical transducer embedded, without welding, at one end and inside a metallic pipe, that resonates at the resonant frequency of the metallic pipe, and that at its other end has embedded a countermass or other electromechanical transducer system of identical characteristics and assembly, and with connection cables running either through the countermass or through a node of minimum vibration of the metallic pipe, where there is fixed a smaller diameter pipe, for its subjection.
The portable ultrasound tubular transducer basically consist of the combination of three elements or assemblies:
an electromechanical transducer assembly where electric power is converted in mechanical energy; a metallic pipe that makes itself resonate, and a countermass that resonates at the same frequency and that is used as a part of a subjection medium of the transducer. If the countermass is not employed, this is replaced by other electromechanical transducer assembly.
In a preferred version of the electromechanical transducer assembly one or more pre-stressed piezoelectric crystals are used, for example by means of a central rod, coupled to two masses that conform a resonant motor, one of them being embedded in the metallic pipe.
The number of crystals and their diameter depend on the frequency and the power at which its use is intended.
This electromechanical transducer assembly is coupled to the pipe which length and diameter are determined according to the specific application.
The countermass is embedded in the other end of the metallic pipe and has a central perforation for the assemblage of the smaller diameter pipe for the support of the portable transducer and for the passage of the cables, or for the connection of a hollow flexible pipe that allows the passage of the feeding cables and the introduction of the portable transducer inside a pipework.
When two electromechanical transducers assemblies are employed which assemblies are embedded in both ends of the pipe, the countermass is not used, the metallic pipe being provided with a smaller diameter pipe which is welded in its middle part to support the transducer and for passage of the cables.

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An apparatus for efficiently detecting errors in a system having a plurality of memory devices. The present invention uses a single parity bit configuration to detect common data errors caused by faulty memory devices including multiple data errors within one memory device. This is accomplished by effectively turning a multiple bit error detection situation into a single bit error detection situation. Thus, instead of allocating a contiguous block of bits to the same memory unit, the present invention allocates bits across all memory units in a round-robin fashion. The parity domains are defined such that multiple errors within one SRAM can be detected despite only using a single bit parity configuration.

1. Field of the Invention
The present invention is generally related to general purpose, stored program, digital computers and more particularly relates to efficient means for performing memory error detection.
2. Description of the Prior Art
A key design element of high reliability computer systems is that of error detection and correction. It has long been recognized that the integrity of the data bits within the computer system is critical to ensure the accuracy of operations performed in the data processing system. The alteration of one data bit in a data word can dramatically affect arithmetic calculations or can change the meaning of a data word as interpreted by other sub-systems within the computer system. Often the cause of an altered data bit is traced to a faulty memory element within the computer system and therefore it is critical that error detection be performed on the memory elements.
One method for performing error detection on the memory elements is to associate an additional bit, called a "parity bit", along with the binary bits comprising an addressable word. This method involves summing without carry the bits representing a "one" within a data word and providing an additional "parity bit" so that the total number of "ones" across the data word including the added parity bit is either odd or even. The term "Even Parity" refers to a parity mechanism which provides an even number of ones across the data word including the parity bit. Similarly, the term "Odd Parity" refers to a parity mechanism which provides an odd number of ones across the data word including the parity bit.
A typical system which uses parity as an error detection mechanism has a parity generation circuit for generating the parity bit. When the system stores a data word into memory, the parity generation circuit generates a parity bit from the data word and the system stores both the data word and the corresponding parity bit into an address location in a memory. When the system reads the address location where the data word is stored, both the data word and the corresponding parity bit are read from the memory. The parity generation circuit then regenerates the parity bit from the data bits read from the memory device and compares the regenerated parity bit with the parity bit that is stored in memory. If the regenerated parity bit and the original parity bit do not compare, an error is detected and the system is notified.
It is readily known that a single parity bit in conjunction with a multiple bit data word can detect a single bit error within the data word. However, it is also readily known that a single parity bit in conjunction with a multiple bit data word can be defeated by multiple errors within the data word. As calculation rates increase, circuit sizes decrease, and voltage levels of internal signals decrease, the likelihood of a multiple errors within a data word increase. Therefore, methods to detect multiple errors within a data word are essential.
System designers have developed methods for detecting multiple errors within multiple bit data words by providing multiple parity bits for each multiple bit data word. Although this technique has been successfully used, it significantly increases the overhead required to perform error detection because the parity generation circuit is more complex and the additional parity bits must be stored along with each data word. It can readily be seen that each additional parity bit that is included within a system adds a significant amount of overhead to the system.
Parity generation techniques are also used to perform error correction within a data word. Error correction is typically performed by encoding the data word to provide error correction code bits that are stored along with the bits of the data word. Upon readout, the data bits read from the addressable memory location are again subject to the generation of the same error correction code signal pattern. The newly generated pattern is compared to the error correction code signals stored in memory. If a difference is detected, it is determined that the data word is erroneous. Depending on the encoding system utilized it is possible to identify and correct the bit position in the data word indicated as being incorrect. The system overhead for the utilization of error correction code signals is substantial. The overhead includes the time necessary to generate the error correction codes, the memory cells necessary to store the error correction codes for each corresponding data word, and the time required to perform the decode when the data word is read from memory. These represent disadvantages to the error correction code system.
As can be seen from the previous discussion, a single parity bit system which stores the parity bit along with the data word requires the least amount of overhead within the system. The disadvantage of a single parity bit system is that only single bit failures can be detected. In prior art systems, a parity bit is typically provided for each data word that is stored within a memory device. Furthermore, the parity bit and the corresponding data word are typically stored at the same address location within the memory device. This is true even if there are multiple memory devices within the computer system. That is, each memory unit is treated independent from the others and therefore each memory unit stores both data words and the corresponding parity bits. Typically, there are three types of errors that occur within a memory device. The first type of error is an error in any single bit within the memory device. These errors will be detected by a single parity bit being stored along with the corresponding data word as discussed above. The second type of error is an error in multiple bits in a memory device. For example, if bit 0 and bit 1 both failed, they may cancel each other out when it comes to computing the parity bit, and the error may go undetected. This is a result of the two bits being in the same "parity domain". A parity domain is defined as a group of bits from which the parity bit is being calculated. Thus some multiple bit errors in a memory device will not be detected under the single bit parity method as described above. The third type of error is a chip failure. For example, if an address driver in a memory device fails, a location within the memory device other than the intended location may be read, but a valid parity bit could still result. Thus a chip failure may not be detected under the single parity bit method as described above.
It is apparent that the previously described single bit parity configuration is highly desirable because of the low system overhead but the ability of this configuration to detect typical errors within a memory device is limited.

Multiple memory bit/chip failure detection


A broad-range light-detection system. In some embodiments, the system includes apparatus and methods for detecting light with high accuracy over a broad range of intensities. In other embodiments, the system includes apparatus and methods for automatically scaling the detection range to improve detection based on the intensity of the detected light. In yet other embodiments, the system includes apparatus and methods for detecting light with increased speed, particularly in applications involving analysis of successive samples.

Systems that involve the detection of light are used in a variety of contexts. In particular, systems that involve the detection and subsequent analysis of light are used in performing optical spectroscopic assays, including luminescence and absorption assays. These assays are used to characterize the components and properties of molecular systems, and recently have been used in high-throughput screening procedures to identify candidate drug compounds. Optical spectroscopic assays include fluorescence polarization (FP), fluorescence resonance energy transfer (FRET), fluorescence lifetime (FLT), total internal reflection (TIR) fluorescence, fluorescence correlation spectroscopy (FCS), and fluorescence recovery after photobleaching (FRAP), and their phosphorescence analogs, among others. Optical spectroscopic assays also include absorption assays.
Unfortunately, light detection systems suffer from a number of shortcomings. Such systems may be limited in range, so that they accurately detect light only within some relatively narrow range of intensities. Such systems also may require user intervention to alter the detection range, if the range may be altered at all. Such systems also may be limited to either discrete or analog detection, so that either they discretely count individual quanta or photons of light, or they integrate an analog value corresponding to such quanta, but they do not do both. Such systems also may require significant periods of time to make measurements. These shortcomings may be found singly or in combination, and these shortcomings may be particularly significant in the context of high-throughput screening, where it may be necessary to perform tens or hundreds of thousands of measurements per day.


All purpose cleaning or microemulsion compositions more environmentally friendly, which is especially effective in the removal of oily or greasy soils contains a positively charged surfactant-polymer complex, a hydrocarbon ingredient, a cosurfactant, and water.

The present invention relates to a hard surface cleaning composition containing a positively charged complex.
This invention relates to an improved all-purpose liquid cleaner designed in particular for cleaning hard surfaces and which is effective in removing grease soil and/or bath soil and in leaving unrinsed surfaces with a shiny appearance.
In recent years all-purpose liquid detergents have become widely accepted for cleaning hard surfaces, e.g., painted woodwork and panels, tiled walls, wash bowls, bathtubs, linoleum or tile floors, washable wall paper, etc. Such all-purpose liquids comprise clear and opaque aqueous mixtures of water-soluble synthetic organic detergents and water-soluble detergent builder salts. In order to achieve comparable cleaning efficiency with granular or powdered all-purpose cleaning compositions, use of water-soluble inorganic phosphate builder salts was favored in the prior art all-purpose liquids. For example, such early phosphate-containing compositions are described in U.S. Pat. Nos. 2,560,839; 3,234,138; 3,350,319; and British Patent No.1,223,739.
In view of the environmentalist""s efforts to reduce phosphate levels in ground water, improved all-purpose liquids containing reduced concentrations of inorganic phosphate builder salts or non-phosphate builder salts have appeared. A particularly useful self-opacified liquid of the latter type is described in U.S. Pat. No. 4,244,840.
However, these prior art all-purpose liquid detergents containing detergent builder salts or other equivalent tend to leave films, spots or streaks on cleaned unrinsed surfaces, particularly shiny surfaces. Thus, such liquids require thorough rinsing of the cleaned surfaces which is a time-consuming chore for the user. In order to overcome the foregoing disadvantage of the prior art all-purpose liquid, U.S. Pat. No. 4,017,409 teaches that a mixture of paraffin sulfonate and a reduced concentration of inorganic phosphate builder salt should be employed. However, such compositions are not completely acceptable from an environmental point of view based upon the phosphate content. On the other hand, another alternative to achieving phosphate-free all-purpose liquids has been to use a major proportion of a mixture of anionic and nonionic detergents with minor amounts of glycol ether solvent and organic amine as shown in U.S. Pat. No. 3,935,130. Again, this approach has not been completely satisfactory and the high levels of organic detergents necessary to achieve cleaning cause foaming which, in turn, leads to the need for thorough rinsing which has been found to be undesirable to today""s consumers.
Another approach to formulating hard surfaced or all-purpose liquid detergent composition where product homogeneity and clarity are important considerations involves the formation of oil-in-water (o/w) microemulsions which contain one or more surface-active detergent compounds, a water-immiscible solvent (typically a hydrocarbon solvent), water and a xe2x80x9ccosurfactantxe2x80x9d compound which provides product stability. By definition, an o/w microemulsion is a spontaneously forming colloidal dispersion of xe2x80x9coilxe2x80x9d phase particles having a particle size in the range of 25 to 800 xc3x85 in a continuous aqueous phase.
In view of the extremely fine particle size of the dispersed oil phase particles, microemulsions are transparent to light and are clear and usually highly stable against phase separation.
Patent disclosures relating to use of grease-removal solvents in o/w microemulsions include, for example, European Patent Applications EP 0137615 and EP 0137616xe2x80x94Herbots et al; European Patent Application EP 0160762xe2x80x94Johnston et al; and U.S. Pat. No. 4,561,991xe2x80x94Herbots et al. Each of these patent disclosures also teaches using at least 5% by weight of grease-removal solvent.
It also is known from British Patent Application GB 2144763A to Herbots et al, published Mar. 13, 1985, that magnesium salts enhance grease-removal performance of organic grease-removal solvents, such as the terpenes, in o/w microemulsion liquid detergent compositions. The compositions of this invention described by Herbots et al. require at least 5% of the mixture of grease-removal solvent and magnesium salt and preferably at least 5% of solvent (which may be a mixture of water-immiscible non-polar solvent with a sparingly soluble slightly polar solvent) and at least 0.1% magnesium salt.
However, since the amount of water immiscible and sparingly soluble components which can be present in an o/w microemulsion, with low total active ingredients without impairing the stability of the microemulsion is rather limited (for example, up to 18% by weight of the aqueous phase), the presence of such high quantities of grease-removal solvent tend to reduce the total amount of greasy or oily soils which can be taken up by and into the microemulsion without causing phase separation.
The following representative prior art patents also relate to liquid detergent cleaning compositions in the form of o/w microemulsions: U.S. Pat. No. 4,472,291xe2x80x94Rosario; U.S. Pat. No. 4,540,448xe2x80x94Gauteer et al; U.S. Pat. No. 3,723,330xe2x80x94Sheflin; etc.
Liquid detergent compositions which include terpenes, such as d-limonene, or other grease-removal solvent, although not disclosed to be in the form of o/w microemulsions, are the subject matter of the following representative patent documents: European Patent Application 0080749; British Patent Specification 1,603,047; 4,414,128; and 4,540,505. For example, U.S. Pat. No. 4,414,128 broadly discloses an aqueous liquid detergent composition characterized by, by weight:
(a) from 1% to 20% of a synthetic anionic, nonionic, amphoteric or zwitterionic surfactant or mixture thereof;
(b) from 0.5% to 10% of a mono- or sesquiterpene or mixture thereof, at a weight ratio of (a):(b) being in the range of 5:1 to 1:3; and
(c ) from 0.5% 10% of a polar solvent having a solubility in water at 15xc2x0 C. in the range of from 0.2% to 10%. Other ingredients present in the formulations disclosed in this patent include from 0.05% to 2% by weight of an alkali metal, ammonium or alkanolammonium soap of a C13-C24 fatty acid; a calcium sequestrant from 0.5% to 13% by weight; non-aqueous solvent, e.g., alcohols and glycol ethers, up to 10% by weight; and hydrotropes, e.g., urea, ethanolamines, salts of lower alkylaryl sulfonates, up to 10% by weight. All of the formulations shown in the Examples of this patent include relatively large amounts of detergent builder salts which are detrimental to surface shine.
A pH neutral microemulsion composition based on paraffin sulfonate and ethoxylated nonionic surfactant is able to deliver improved grease cleaning versus built, alkaline compositions. Besides the improved grease cleaning, this approach is much safer to surfaces as well as less aggressive on consumer""s hands (Loth et alxe2x80x94U.S. Pat. No. 5,075,026).
The microemulsion technology provides outstanding oil uptake capacity because of the adjustment of the curvature of the surfactant micelles by the molecules of the cosurfactant. Rod-like micelles are preferred as they can xe2x80x9cswallowxe2x80x9d oil to become globular without increasing the surface of contact between the hydrophobic core of the micelle and the hydrophilic continuous phase.
In diluted usage however, the microemulsion state is usually lost and the cleaning performance relies on the adsorption efficacy and leaving character of the surfactant system. Nonionic surfactants perform very well on grease, as they are excellent grease xe2x80x9csolubilizersxe2x80x9d. Actually, they spontaneously form swollen micelles. In moderate climate countries such as the northern states of the United States and the northern countries of Europe, the soil on the hard surfaces contains a major proportion of greasy materials. It is accordingly not surprising that the anionic-nonionic surfactant based microemulsion is very efficient in those countries. However, nonionic surfactants do not impart oil repelling properties and can not deliver soil antiattachment properties on treated hard surfaces so as to achieve next time easier cleaning of said treated surface.
The instant invention teaches hard surface cleaning containing a positively charged complex of an anionic surfactant which is an alkali metal salt of a nonfluorinated anionic surfactant or an ammonium salt of a nonfluorinated anionic surfactant, or a mixture thereof, which exhibits very low surface tensions with a polycationic polymer that imparts oil repelling properties and delivers soil antiattachment properties on treated hard surfaces and delivers this desired property.
The present invention provides an improved, clear, liquid hard surface cleaning composition having improved interfacial tension which improves cleaning hard surfaces such as plastic, vitreous and metal surfaces having a shiny finish, oil stained floors, automative engines and other engines. More particularly, the improved cleaning compositions exhibit good grease soil removal properties and leave the cleaned surfaces shiny without the need of or requiring only minimal additional rinsing or wiping. The latter characteristic is evidenced by little or no visible residues on the unrinsed cleaned surfaces and, accordingly, overcomes one of the disadvantages of prior art products. The instant compositions exhibit a grease release effect in that the instant compositions impede or decrease the anchoring of greasy soil on surfaces that have been cleaned with the instant compositions as compared to surfaces cleaned with a microemulsion composition which means that the grease soiled surface is easier to clean upon subsequent cleanings.
Surprisingly, these desirable results are accomplished even in the absence of polyphosphate or other inorganic or organic detergent builder salts and also in the complete absence or substantially complete absence of grease-removal solvent.
The invention generally provides a stable, clear all-purpose, hard surface cleaning composition especially effective in the removal of oily and greasy oil. The cleaning composition includes, on a weight basis:
about 0.1% to about 20%, more preferably about 0.2% to about 15% of a positively charged complex comprising at least one alkali metal salt of a nonfluorinated anionic surfactant or an ammonium salt of a nonfluorinated anionic surfactant, or a mixture thereof and a polycationic polymer;
about 0 to about 25%, more preferably 1% to 20%, of a water-mixable cosurfactant having either limited ability or substantially no ability to dissolve oily or greasy soil;
0 to about 1.5% of a fatty acid;
0 to about 5% of magnesium sulfate heptahydrate;
about 0 to about 5.0% of a perfume or water insoluble hydrocarbon; and
the balance being water, said proportions being based upon the total weight of the composition.
The cleaning composition can be in the form of a microemulsion in which case the concentration of the water mixable cosurfactant is about 0 to about 25 wt. %, preferably about 1 wt. % to about 20 wt. % and the concentration of the perfume or water insoluble hydrocarbon is about 0.4 wt. % to about 5.0 wt. %. The dispersed oil phase of the o/w microemulsion is composed essentially of a water-immiscible or hardly water-soluble perfume.
The present invention relates to a stable all purpose hard surface cleaning or microemulsion composition containing a surfactant-polymer complex for delivering soil antiattachment properties. The invention also relates to a light duty liquid composition or light duty liquid microemulsion composition. This present invention also useful in the formation of toilet bowl cleaners.
The present invention relates to a stable hard surface cleaning composition approximately by weight: 0.1% to 20% of a positively charged complex of an alkali metal salt of a nonfluorinated anionic surfactant or an ammonium salt of a nonfluorinated anionic surfactant, or a mixture thereof and a polycationic polymer, 0 to 25% of a cosurfactant, 0 to 5% of a water insoluble hydrocarbon or a perfume and the balance being water, wherein the cleaning composition can be in the form of a microemulsion in which case the concentration of the water mixable cosurfactant is about 0 to about 25.0 wt. %, preferably about 0.1 wt. % to about 25.0 wt. % and the concentration of the perfume or water insoluble hydrocarbon is about 0.4 wt. % to about 5.0 wt. %.
When mixing an alkali metal salt such as sodium of a nonfluorinated anionic surfactant or an ammonium salt of a nonfluorinated anionic surfactant, or a mixture thereof and a polycationic polymer, attractive interactions are developed that are very strong and lead to the formation of anionic-cationic complexes in-situ. The complex interactions take place along the polymer backbone, so that surfactant-polymer complexes exist in solution. Attention must be paid not to complex all the positive charges on the polycationic polymer so as to still have enough electric charges on the whole structure so that the complex is positively charged so as to keep the complex water soluble (otherwise phase separation or precipitation might occur). The presence of positive charges on the surfactant-polymer system allows subsequent anchorage on substrate surface for modifying the surface energy.
One of the objects of the instant invention is to deliver higher proportions of anionic surfactant in the adsorbed layer at the solid-water interface. This is due to a boosted adsorption tendency by means of neutralization between the negative charge of the anionic surfactant and the positive charge of the polycationic polymer that is used in admixture with the anionic surfactant in the instant compositions and due to an increased hydrophobic character imparted to the polymer by the anionic surfactant linked to its backbone. Two anionic surfactants can be used in composition wherein one of the anionic surfactants will possibly preferentially associate with the polycationic polymer through electrostatic interactions.
According to the present invention, the role of the hydrocarbon is provided by a non-water-soluble perfume. Typically, in aqueous based compositions the presence of a solubilizers, such as alkali metal lower alkyl aryl sulfonate hydrotrope, triethanolamine, urea, etc., is required for perfume dissolution, especially at perfume levels of 1% and higher, since perfumes are generally a mixture of fragrant essential oils and aromatic compounds which are generally not water-soluble. Therefore, by incorporating the perfume into the aqueous cleaning composition as the oil (hydrocarbon) phase of the ultimate o/w microemulsion composition, several different important advantages are achieved.
First, the cosmetic properties of the ultimate cleaning composition are improved: the compositions are both clear (as a consequence of the formation of a microemulsion) and highly fragranced (as a consequence of the perfume level).
Second, the need for use of solubilizers, which do not contribute to cleaning performance, is eliminated.
Third, an improved grease release effect and an improved grease removal capacity in neat (undiluted) usage of the composition or after dilution of the composition can be obtained without detergent builders or buffers or conventional grease removal solvents at neutral or acidic pH and at low levels of active ingredients while improved cleaning performance can also be achieved in diluted usage.
As used herein and in the appended claims the term xe2x80x9cperfumexe2x80x9d is used in its ordinary sense to refer to and include any non-water soluble fragrant substance or mixture of substances including natural (i.e., obtained by extraction of flower, herb, blossom or plant), artificial (i.e., mixture of natural oils or oil constituents) and synthetically produced substance) odoriferous substances. Typically, perfumes are complex mixtures of blends of various organic compounds such as alcohols, aldehydes, ethers, aromatic compounds and varying amounts of essential oils (e.g., terpenes) such as from 0% to 80%, usually from 10% to 70% by weight. The essential oils themselves are volatile odoriferous compounds and also serve to dissolve the other components of the perfume.
In the present invention the precise composition of the perfume is of no particular consequence to cleaning performance so long as it meets the criteria of water immiscibility and having a pleasing odor. Naturally, of course, especially for cleaning compositions intended for use in the home, the perfume, as well as all other ingredients, should be cosmetically acceptable, i.e., non-toxic, hypoallergenic, etc.
The hydrocarbon such as a perfume is present in the hard surface cleaning composition in an amount of from 0 to 5% by weight, preferably 0.4% to 5% by weight, more preferably from 0.4% to 3.0% by weight, especially preferably from 0.5% to 2.0% by weight. If the hydrocarbon (perfume) is added in amounts more than 5% by weight, the cost is increased without any additional cleaning benefit and, in fact, with some diminishing of cleaning performance insofar as the total amount of greasy or oily soil which can be taken up in the oil phase of the microemulsion will decrease proportionately.
Furthermore, although superior grease removal performance will be achieved for perfume compositions not containing any terpene solvents, it is apparently difficult for perfumers to formulate sufficiently inexpensive perfume compositions for products of this type (i.e., very cost sensitive consumer-type products) which includes less than 20%, usually less than 30%, of such terpene solvents.
Thus, merely as a practical matter, based on economic consideration, the microemulsion compositions of the present invention may often include as much as 0.2% to 7% by weight, based on the total composition, of terpene solvents introduced thereunto via the perfume component. However, even when the amount of terpene solvent in the cleaning formulation is less than 1.5% by weight, such as up to 0.6% by weight or 0.4% by weight or less, satisfactory grease removal and oil removal capacity is provided by the inventive diluted microemulsions.
In place of the perfume one can employ a water insoluble paraffin or isoparaffin having 6 to 18 carbon at a concentration of 0 to 5 wt. percent, preferably 0.4 to 5.0 wt. percent, more preferably 0.4 to 3.0 wt. %.
The positively charged complex contained in the instant compositions comprises a complex of:
(a) an alkali metal salt such as sodium of a nonfluorinated anionic surfactant or an ammonium salt of a nonfluorinated anionic surfactant, or a mixture thereof; and
(b) a polycationic polymer, wherein the molar ratio of the anionic surfactant to the positively charged binding sites available on the polycationic polymer backbone is 0.95:1 to 0.05:1, more preferably 0.9:1 to 0.1:1. The instant composition contains about 0.1 to about 20 wt. %, more preferably about 0.2 to about 15 wt. % of the positively charged complex.
Suitable water-soluble non-soap, anionic surfactants which are nonfluorinated which are used in the instant compositions include those surface-active or detergent compounds which contain an organic hydrophobic group containing generally 8 to 26 carbon atoms and preferably 10 to 18 carbon atoms in their molecular structure and at least one water-solubilizing group selected from the group of sulfonate, sulfate and carboxylate so as to form a water-soluble detergent. Usually, the hydrophobic group will include or comprise a C8-C22 alkyl, alkyl or acyl group. Such surfactants are employed in the form of water-soluble salts and the salt-forming cation usually is selected from the group consisting of sodium, potassium, ammonium, magnesium and mono-, di- or tri-C2-C3 alkanolammonium, with the sodium, magnesium and ammonium cations again being preferred.
Examples of suitable sulfonated anionic surfactants are the well known higher alkyl mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates containing from 10 to 16 carbon atoms in the higher alkyl group in a straight or branched chain, C8-C15 alkyl toluene sulfonates and C8-C15 alkyl phenol sulfonates.
A preferred sulfonate is linear alkyl benzene sulfonate having a high content of 3-(or higher) phenyl isomers and a correspondingly low content (well below 50%) of 2-(or lower) phenyl isomers, that is, wherein the benzene ring is preferably attached in large part at the 3 or higher (for example, 4, 5, 6 or 7) position of the alkyl group and the content of the isomers in which the benzene ring is attached in the 2 or 1 position is correspondingly low.
Other suitable anionic surfactants are the olefin sulfonates, including long-chain alkene sulfonates, long-chain hydroxyalkane sulfonates or mixtures of alkene sulfonates and hydroxyalkane sulfonates. These olefin sulfonate detergents may be prepared in a known manner by the reaction of sulfur trioxide (SO3) with long-chain olefins containing 8 to 25, preferably 12 to 21 carbon atoms and having the formula RCHxe2x95x90CHR1 where R is a higher alkyl group of 6 to 23 carbons and R1 is an alkyl group of 1 to 17 carbons or hydrogen to form a mixture of sultones and alkene sulfonic acids which is then treated to convert the sultones to sulfonates. Preferred olefin sulfonates contain from 14 to 16 carbon atoms in the R alkyl group and are obtained by sulfonating an xcex1-olefin.
Other examples of suitable anionic sulfonate surfactants are the paraffin sulfonates containing 10 to 20, preferably 13 to 17, carbon atoms. Primary paraffin sulfonates are made by reacting long-chain alpha olefins and bisulfites and paraffin sulfonates having the sulfonate group distributed along the paraffin chain are shown in U.S. Pat. Nos. 2,503,280; 2,507,088; 3,260,744; 3,372,188; and German Patent 735,096.
Examples of satisfactory anionic sulfate surfactants are the C8-C18 alkyl sulfate salts the ethoxylated C8-C18 alkyl ether sulfate salts having the formula R(OC2H4)nOSO3M wherein n is 1 to 12, preferably 1 to 5, and M is a metal cation selected from the group consisting of sodium, potassium, ammonium, magnesium and mono-, di- and triethanol ammonium ions. The alkyl sulfates may be obtained by sulfating the alcohols obtained by reducing glycerides of coconut oil or tallow or mixtures thereof and neutralizing the resultant product.
On the other hand, the ethoxylated alkyl ether sulfates are obtained by sulfating the condensation product of ethylene oxide with a C8-C18 alkanol and neutralizing the resultant product. The alkyl sulfates may be obtained by sulfating the alcohols obtained by reducing glycerides of coconut oil or tallow or mixtures thereof and neutralizing the resultant product. The ethoxylated alkyl ether sulfates differ from one another in the number of moles of ethylene oxide reacted with one mole of alkanol. Preferred alkyl sulfates and preferred ethoxylated alkyl ether sulfates contain 10 to 16 carbon atoms in the alkyl group.
The ethoxylated C8-C12 alkylphenyl ether sulfates containing from 2 to 6 moles of ethylene oxide in the molecule also are suitable for use in the inventive compositions. These surfactants can be prepared by reacting an alkyl phenol with 2 to 6 moles of ethylene oxide and sulfating and neutralizing the resultant ethoxylated alkylphenol.
Other suitable anionic surfactants are the C9-C15 alkyl ether polyethenoxyl carboxylates having the structural formula R(OC2H4)nOX COOH wherein n is a number from 4 to 12, preferably 5 to 10 and X is selected from the group consisting of CH2, (C(O)R1 and
wherein R1 is a C1-C3 alkylene group. Preferred compounds include C9-C11 alkyl ether polyethenoxy (7-9)C(O)CH2CH2COOH, C13-C15 alkyl ether polyethenoxy (7-9)
and C10-C12 alkyl ether polyethenoxy (5-7) CH2COOH. These compounds may be prepared by condensing ethylene oxide with appropriate alkanol and reacting this reaction product with chloracetic acid to make the ether carboxylic acids as shown in U.S. Pat. No. 3,741,911 or with succinic anhydride or phthalic anhydride. Obviously, these anionic surfactants will be present either in acid form or salt form depending upon the pH of the final composition, with salt forming cation being the same as for the other anionic surfactants.
The polycationic polymer is a polyacrylamide dialkyl dimethyl ammonium chloride copolymer having about 25 wt. % to 90 wt. % of the dialkyl dimethyl ammonium chloride monomer and is depicted by the structure of:
wherein m is about 5000 to about 60000.
Another useful polycationic polymer is a polyvinyl pyrrolidone/vinyl imidazole/quaternized vinyl-imidazole [40/40/20] terpolymer. The ratio of comonomers in the foregoing terpolymer is not particularly critical and can be modified to provide the desired soil antiattachment effect.
A cosurfactant can be optionally used in forming the microemulsion composition.
Three major classes of compounds have been found to provide highly suitable cosurfactants over temperature ranges extending from 5xc2x0 C. to 43xc2x0 C. for instance; (1) water-soluble C3-C4 alkanols, polyethylene glycols of the formula HO(CH2CH2O)nH wherein n is about 8 to about 14, polypropylene glycol of the formula HO(CH3CHCH2O)nH wherein n is a number from 2 to 18 and copolymers of ethylene oxide and propylene oxide and mono C1-C6 alkyl ethers and esters of ethylene glycol and propylene glycol having the structural formulas R(X)nOH and R1(X)nOH wherein R is C1-C6 alkyl, R1 is C2-C4 acyl group, X is (OCH2CH2) or (OCH2(CH3)CH) and n is a number from 1 to 4; (2) aliphatic mono- and di-carboxylic acids containing 2 to 10 carbon atoms, preferably 3 to 6 carbons in the molecule; and (3) triethyl phosphate. Additionally, mixtures of two or more of the three classes of cosurfactant compounds may be employed where specific pH""s are desired.
When the mono- and di-carboxylic acid (Class 2) cosurfactants are employed in the instant microemulsion compositions at a concentration of 2 to 10 wt. %, the microemulsion compositions can be used as a cleaners for bathtubs and other hard surfaced items, which are acid resistant thereby removing lime scale, soap scum and greasy soil from the surfaces of such items damaging such surfaces. If these surfaces are of zirconium white enamel, they can be damaged by these compositions.
An aminoalkylene phophoric acid at a concentration of 0.01 to 0.2 wt. % can be optionally used in conjunction with the mono- and di-carboxylic acids, wherein the aminoalkylene phosphoric acid helps prevent damage to zirconium white enamel surfaces. Additionally, 0.05 to 1% of phosphoric acid can be used in the composition.
Representative members of the polypropylene glycol include dipropylene glycol and polypropylene glycol having a molecular weight of 200 to 1000, e.g., polypropylene glycol 400. Other satisfactory glycol ethers are ethylene glycol monobutyl ether(butyl cellosolve), diethylene glycol monobutyl ether(butyl carbitol), propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, triethylene glycol monobutyl ether, mono, di, tri propylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, triethylene glycol monohexyl ether, tetraethylene glycol monohexyl ether, pentaethylene glycol monohexyl ether, propylene glycol tertiary butyl ether, ethylene glycol monoacetate and dipropylene glycol propionate.
Representative members of the aliphatic carboxylic acids include C3-C6 alkyl and alkenyl monobasic acids such as acrylic acid and propionic acid and dibasic acids such as glutaric acid and mixtures of glutaric acid with adipic acid and succinic acid, as well as mixtures of the foregoing acids.
While all of the aforementioned glycol ether compounds and acid compounds provide the described stability, the most preferred cosurfactant compounds of each type, on the basis of cost and cosmetic appearance (particularly odor), are diethylene glycol monobutyl ether or pentaethylene glycol monohexyl ether, and a mixture of adipic, glutaric and succinic acids, respectively. The ratio of acids in the foregoing mixture is not particularly critical and can be modified to provide the desired odor. Generally, to maximize water solubility of the acid mixture glutaric acid, the most water-soluble of these three saturated aliphatic dibasic acids, will be used as the major component.
Generally, weight ratios of adipic acid: glutaric acid:succinic acid is 1-3:1-8:1-5, preferably 1-2:1-6:1-3, such as 1:1:1, 1:2:1, 2:2:1, 1:2:1.5, 1:2:2, 2:3:2, etc. can be used with equally good results.
Still other classes of cosurfactant compounds providing stable microemulsion compositions at low and elevated temperatures are the mono-, di- and triethyl esters of phosphoric acid such as triethyl phosphate.
The amount of cosurfactant which might be required to stabilize the microemulsion compositions will, of course, depend on such factors as the surface tension characteristics of the cosurfactant, the type and amounts of the complex and perfumes, and the type and amounts of any other additional ingredients which may be present in the composition and which have an influence on the thermodynamic factors enumerated above. Generally, amounts of cosurfactant in the range of from 0 to 25 wt. %, preferably from 0.5 wt. % to 20 wt. %, especially preferably from 1 wt. % to 10 wt. %, provide stable microemulsions for the above-described levels of primary surfactants and perfume and any other additional ingredients as described below.
As will be appreciated by the practitioner, the pH of the final microemulsion will be dependent upon the identity of the cosurfactant compound, with the choice of the cosurfactant being effected by cost and cosmetic properties, particularly odor. For example, microemulsion compositions which have a pH in the range of 1 to 10 may employ either the class 1 or the class 4 cosurfactant as the sole cosurfactant, but the pH range is reduced to 1 to 8.5 when the polyvalent metal salt is present. On the other hand, the class 2 cosurfactant can only be used as the sole cosurfactant where the product pH is below 3.2. However, where the acidic cosurfactants are employed in admixture with a glycol ether cosurfactant, compositions can be formulated at a substantially neutral pH (e.g., pH 7xc2x11.5, preferably 7xc2x10.2).
The ability to formulate neutral and acidic products without builders which have grease removal capacities is a feature of the present invention because the prior art o/w microemulsion formulations most usually are highly alkaline or highly built or both.
The final essential ingredient in the inventive hard surface cleaning compositions having improved interfacial tension properties is water. The proportion of water in the microemulsion compositions generally is in the range of 60 wt. % to 97 wt. %, preferably 80 wt. % to 97 wt. % of the usual diluted o/w microemulsion composition.
The present invention also relates to a stable concentrated microemulsion or acidic microemulsion composition comprising approximately by weight:
(a) 0.1 to 20% of a positively charged complex as previously herein defined;
(b) 0 to 1.5% of a fatty acid;
(c) 1 to 25% of a cosurfactant;
(d) 0.4 to 5% of a water insoluble hydrocarbon or perfume;
(e) 0 to 10% of at least one dicarboxylic acid;
(f) 0 to 1% of phosphoric acid;
(g) 0 to 0.2% of an aminoalkylene phosphoric acid;
(h) 0 to 5% of magnesium sulfate heptahydrate; and
(i) the balance being water.
The present invention also relates to a light duty liquid composition or light duty liquid microemulsion composition which comprises approximately by weight:
(a) 0.1% to 20% of the previously defined positively charged complex;
(b) 0 to 5% of a perfume, an essential oil or a water insoluble hydrocarbon;
(c) 0 to 25% of a cosurfactant; and
(d) the balance being water.
In addition to the above-described essential ingredients required for the formation of the all purpose cleaning or microemulsion composition, the compositions of this invention may often and preferably do contain one or more additional ingredients which serve to improve overall product performance.
One such ingredient is a source of acidity such as hydrochloric acid or sulfuric acid for use in the formation of toilet bowl cleaners.
Another optional ingredient for use herein is an inorganic or organic salt of oxide of a multivalent metal cation, particularly Mg++. The metal salt or oxide provides several benefits including improved cleaning performance in dilute usage, particularly in soft water areas, and minimized amounts of perfume required to obtain the microemulsion state. Magnesium sulfate, either anhydrous or hydrated (e.g., heptahydrate), is especially preferred as the magnesium salt. Good results also have been obtained with magnesium oxide, magnesium chloride, magnesium acetate, magnesium propionate and magnesium hydroxide. These magnesium salts can be used with formulations at neutral or acidic pH since magnesium hydroxide will not precipitate at these pH levels.
Although magnesium is the preferred multivalent metal from which the salts (inclusive of the oxide and hydroxide) are formed, other polyvalent metal ions also can be used provided that their salts are nontoxic and are soluble in the aqueous phase of the system at the desired pH level.
Thus, depending on such factors as the pH of the system, the nature of the surfactant-polymer complex and cosurfactant, as well as the availability and cost factors, other suitable polyvalent metal ions include aluminum, copper, nickel, iron, calcium, etc. It should be noted, for example, that with the preferred nonfluorinated anionic detergent calcium salts will precipitate and should not be used. It has also been found that the aluminum salts work best at pH below 5 or when a low level, for example 1 weight percent, of citric acid is added to the composition which is designed to have a neutral pH. Alternatively, the aluminum salt can be directly added as the citrate in such case. As the salt, the same general classes of anions as mentioned for the magnesium salts can be used, such as halide (e.g., bromide, chloride), sulfate, nitrate, hydroxide, oxide, acetate, propionate, etc.
The proportion of the multivalent salt generally will be selected so that at the appropriate weight ratio between the anionic surfactant and the polycationic polymer to deliver desired performance from the surfactant-polymer mixture in terms of adsorption properties on hard surfaces and soil antiattachment on treated hard surfaces, the physical stability of the total composition is kept, that can be impaired due to an increased hydrophobicity of the anionic surfactant in the presence of multivalent salt instead of alkali metal cation such as the sodium salt thereof. As a consequence, the proportion of the multivalent salt will be selected so that the added quantity will neutralize from 0.1 to 1.5 equivalents of the anionic surfactant, preferably 0.9 to 1.4 equivalents of the acid form of the anionic surfactant. At higher concentrations of anionic surfactant, the amount of multivalent salt will be in range of 0.5 to 1 equivalents per equivalent of anionic surfactant.
The hard surface cleaning compositions can optionally include from 0 to 1.5 wt. %, preferably from 0.1 wt. % to 1.0 wt. % of the composition of a C8-C22 fatty acid or fatty acid soap as a foam suppressant. The addition of fatty acid or fatty acid soap provides an improvement in the rinseability of the composition whether applied in neat or diluted form. Generally, however, it is necessary to increase the level of cosurfactant to maintain product stability when the fatty acid or soap is present. If more than 1.5 wt. % of a fatty acid is used in the instant compositions, the composition will become unstable at low temperatures as well as having an objectionable smell.
As example of the fatty acids which can be used as such or in the form of soap, mention can be made of distilled coconut oil fatty acids, xe2x80x9cmixed vegetablexe2x80x9d type fatty acids (e.g. high percent of saturated, mono-and/or polyunsaturated C18 chains); oleic acid, stearic acid, palmitic acid, eiocosanoic acid, and the like, generally those fatty acids having from 8 to 22 carbon atoms being acceptable.
The all-purpose liquid cleaning or microemulsion composition of this invention may, if desired, also contain other components either to provide additional effect or to make the product more attractive to the consumer. The following are mentioned by way of example: Colors or dyes in amounts up to 0.5% by weight; bactericides in amounts up to 1% by weight; preservatives or antioxidizing agents, such as formalin, 5-chloro-2-methyl-4-isothaliazolin-3-one, 2,6-di-tert.butyl-p-cresol, etc., in amounts up to 2% by weight; and pH adjusting agents, such as sulfuric acid or sodium hydroxide, as needed. Furthermore, if opaque compositions are desired, up to 4% by weight of an opacifier may be added.
In final form, the all-purpose cleaning or clear microemulsions exhibit stability at reduced and increased temperatures. More specifically, such compositions remain clear and stable in the range of 4xc2x0 C. to 50xc2x0 C., especially 10xc2x0 C. to 43xc2x0 C. Such compositions exhibit a pH in the acid or neutral range depending on intended end use. The liquids are readily pourable and exhibit a viscosity in the range of 6 to 60 milliPascalxc2x7Second (mPas.) as measured at 25xc2x0 C. with a Brookfield RVT Viscometer using a #1 spindle rotating at 20 RPM. Preferably, the viscosity is maintained in the range of 10 to 40 mPas.
The compositions are directly ready for use or can be diluted as desired and in either case no or only minimal rinsing is required and substantially no residue or streaks are left behind. Furthermore, because the compositions are free of detergent builders such as alkali metal polyphosphates they are environmentally acceptable and provide a better xe2x80x9cshinexe2x80x9d on cleaned hard surfaces.
When intended for use in the neat form, the liquid compositions can be packaged under pressure in an aerosol container or in a pump-type sprayer for the so-called spray-and-wipe type of application.
Because the compositions as prepared are aqueous liquid formulations and since no particular mixing is required to form the all purpose cleaning or microemulsion compositions, the compositions are easily prepared simply by combining all the ingredients in a suitable vessel or container. The order of mixing the ingredients is not particularly important and generally the various ingredients can be added sequentially or all at once or in the form of aqueous solutions of each or all of the primary detergents and cosurfactants can be separately prepared and combined with each other and with the perfume. The magnesium salt, or other multivalent metal compound, when present, can be added as an aqueous solution thereof or can be added directly. It is not necessary to use elevated temperatures in the formation step and room temperature is sufficient.


A capacitive card module is composed of a plurality of capacitive switch elements arranged on a carrier layer. In order to reduce parasitic coupling capacitances, the carrier layer is provided with a first shielding surface fashioned as an interconnect grid and connected to a voltage potential, and second shielding surfaces are located in the grid regions of the first shielding surface. The first shielding surface is composed of a conductor material that is electrically more conductive than that of the second shielding surfaces.

1. Field of the Invention
The present invention relates to a capacitive card module which has a plurality of capacitive switch elements arranged side-by-side on an insulating carrier layer and which are connected to one another and respectively composed of conductor surfaces allocated to one another and fashioned into capacitor surfaces.
2. Description of the Prior Art
Capacitive card modules are being utilized to an increasing degree in newly-designed keyboards of professional data processing technology in order to improve the reliability of the keyboards and in order to simultaneously reduce the manufacturing cost.
European patent application Serial No. 88 11 3995.0, for example, discloses a keyboard mechanism wherein a key plate, together with a frame element and a seating part, is fashioned as a one-piece formed part and whereby a capacitive card module is directly secured to the underside of the key plate.
Compared to traditional keyboards whose keys act on switch elements that, via a respective galvanic contact, connect a row line and a column line to one another in a key matrix, the row and column lines in keyboards having capacitive switch elements are not galvanically connected to one another.
For this reason, decoupling elements such as, for example, respective diodes connected in series with the galvanic contacts are likewise not required.
A capacitive switch element can be realized in a simple manner with two conductor surfaces fashioned on a conductor card to form capacitor surfaces these conductor surfaces being connected to respective row lines or, respectively, column line of the key matrix. The actuation of a key merely produces a variation of the capacitance of an appertaining capacitive switch element. This can either occur on the basis of the basis of the approach of a dielectric element or, on the other hand, by reducing the distance between the capacitor surfaces can likewise occur by enlarging one of the capacitor surfaces.
A change in capacitance between row lines and column lines can be recognized with the assistance of an evaluation electronic circuit connected to all row and column lines and an actuated key can be identified with reference to the participating lines.
Function outages due to oxidized or deformed galvanic contacts, as well as due to malfunctioning decoupling element, can therefore not occur in keyboards having capacitive switch elements.
Since capacitive switch elements are composed only of individual conductor surfaces and the conductor surfaces are usually connected to one another via row and column lines, it was obvious for the purpose of reducing costs to provide a common printed circuitboard for all capacitive switch elements of a keyboard, no other electronic component being located on the printed circuitboard. As a rule, such a printed circuitboard is fashioned as a flexible PC foil and is then referred to as a capacitive switch foil.
Involved evaluation electronics is required for such capacitive switch foils obtainable in a great variety of embodiments, since only a very slight change in capacitance occurs as a rule given actuation of a capacitive switch element. Moreover, the change in capacitance to be recognized given actuation of a key is further reduced by parasitic coupling capacitances that can form due to interconnects extending in parallel to one another due to capacitive switching elements lying in tight proximity to one another.
It is therefore an object of the present invention to improve a capacitive card module of the type set forth above such that the influence of parasitic coupling capacitances is reduced.
The above object is achieved, according to the present invention in a capacitive card module having a plurality of capacitive switch elements arranged side-by-side on an insulated carrier member and connected to one another, the capacitive switch elements being respectively composed of conductor surfaces allocated to one another and fashioned into capacitor surfaces, and is characterized in that the insulating carrier layer comprises an electrically conductive first shielding surface fashioned as an interconnect grid at its side facing away from the capacitive switch elements and is provided with a terminal for voltage potential, in that the first shielding surface comprises a second shielding surface in mesh regions which are in electrical contact with the first shielding surface, in that the first shielding surface is composed of a conductor material that is electrically more conductive than that of the second shielding surfaces. According to another feature of the invention, the second shielding surfaces form a closed area and cover the first shielding surface at at least one side.
According to another feature of the invention, the conductor material of the first shielding surface is composed of silver and that of the second shielding surface is composed of graphite.
The expense for the evaluation electronics can be kept low with a card module constructed in accordance with the present invention. The reason for this become clear only given the assumption that the interconnect surfaces of the first shielding surface are negligible overall compared to the surface covered by the second shielding surfaces. It is then assured, in particular, that the two arbitrary lines (row-column lines) of the capacitive card module between which a parasitic coupling capacitance may exist under certain circumstances no longer have any coupling capacitances to the first shielding surface, but do have to the second shielding surfaces.
In principle, coupling capacitances to shielding surfaces are desired so that the electrical noise charges can be coupled by parasitic coupling capacitances from a disturbing line onto a disturbed line can flow off to a voltage potential, usually to ground potential. This is possible in the capacitive card module constructed in accordance with the present invention because the second shielding surfaces are electrically connected to the first shielding surface and the latter is connected to a voltage potential (ground potential). Since, then, both the disturbing as well as the disturbed lines are each connected to the voltage potential via coupling capacitances, these two coupling capacitances are fundamentally connected in series and are therefore connected in parallel to the parasitic coupling capacitance. What is disadvantageous is that the parasitic coupling capacitance is thereby further increased and electrical noise charges can increasingly flow onto the disturbed line.
In the ideal case, electrical noise charges should flow off via the coupling capacitance to the shielding surface and should then flow optimally unimpeded to a voltage potential (ground potential). Electrical noise charges, however, should be impeded from flowing via the coupling capacitances and a shielding surface from one line to another line, for example from a row line onto a column line.
This is achieved in the card module constructed in accordance with the present invention in that the second shielding surfaces have a lower electrical conductivity when compared to the first shielding surface. Electrical noise charges that proceed via a coupling capacitance onto the second shielding surfaces must overcome a certain resistance (for example 10 ohms given graphite) dependent on the electrical conductivity of the second shielding surface until they arrive onto an interconnect of the first shielding surface in which they can then flow off to the voltage potential without impediment (extremely good conductivity, for example 1 ohm given silver). In order to return via a coupling capacitance onto a line, the electrical noise charges would then again have to overcome the resistance of the second shielding surfaces, for which reason the plurality of noise charges proceeding via the shielding surfaces onto a line can be kept low with a card module constructed in accordance with the present invention compared to what is possible given card modules that comprise only one shielding surface composed of a single continuous area.
The conductor materials of silver and graphite can be galvanically combined with one another without problems and also well-suited for being applied in a silk screening process. In order to protect the unusually thin interconnects of the interconnect grid, it is advantageous to fashion the second conductor surfaces as a closed surface and to cover the interconnect grid as a whole. Moreover, the expense for the application of the second shielding surfaces in a silk screening process is thus reduced.


A disposable substantially damp cleansing article is disclosed having a cleansing composition impregnated onto a flexible substrate such as a non-woven cloth. The impregnated compositions include lathering surfactants and water, the compositions having a viscosity ranging from about 50 to about 300,000 centipoise. Amounts of water range from greater than 15% to no higher than about 40% by weight of the total article. Speed of lather formation and foam volume increases within the window of the stated viscosity and water range.

1. Field of the Invention
The invention concerns low-cost, easily manufacturable disposable single use, substantially damp, cleansing articles.
2. The Related Art
Personal cleansing and conditioning products have traditionally been marketed in a variety of forms such as bar soaps, creams, lotions, and gels. These formulations have attempted to satisfy a number of criteria to be acceptable to consumers. These criteria include cleansing effectiveness, skin feel, skin mildness and lather volume. Ideal personal cleansers should gently cleanse the skin or hair, cause little or no irritation, and not leave the skin or hair overly dry after frequent use.
A series of granted and pending patent applications have been published by Procter and Gamble describing disposable personal cleansing products purportedly addressing many of the aforementioned functionality concerns. These products are substantially dry articles having deposited onto a woven or non-woven cloth a cleansing composition of surfactant, structurant, skin conditioning agent and other performance ingredients. The term xe2x80x9csubstantially dryxe2x80x9d is defined in most of these documents as maximum 10%, but in some instances as high as 15% water. Particularly preferred levels are 5% or less. A commercial embodiment sold in the U.S. is Olay(copyright) Daily Facial Cleansing Cloths having water levels of 3-4% by weight of the total cloth article. The technology is described in the following patents.
U.S. Pat. No. 5,951,991 (Wagner et al.) focuses on providing the substrate with a conditioning emulsion separately impregnated from the lathering surfactant onto the cloth substrate. U.S. Pat. No. 5,980,931 (Fowler et al.) emphasizes impregnation of oil soluble conditioning agents. WO 99/55303 (Albacarys et al.) describes skin care actives formulated with the cleansing composition.
Manufacturing processes for these products are reported in U.S. Pat. Nos. 5,952,043 and 5,863,663, both to Mackey et al. These patents teach use of a continuous lipid phase with a high melting waxy material deposited onto the wipe substrate. The material is intended to be sufficiently brittle so as to be easily disrupted by low shear contact (e.g. during wiping of the skin) to readily release an internal skin conditioning phase, yet the material is required to be sufficiently tough to avoid premature release of the internal phase during the rigors of processing. A problem with this technology is that through compromise the continuous external lipid phase/internal polar phase is neither sufficiently robust for processing and handling nor sufficiently releasable under wash conditions to allow efficient release of conditioning agent onto the skin.
More recent publications in this area include WO 01/08542 A1 (Cen et al.), WO 01/08655 A1 (Phipps et al.), WO 01/08656 A1 (Smith et al.), WO 01/08657 A1 (Lorenzi et al.) and WO 01/08658 A1 (Cawkwell et al.), all to Procter and Gamble. These documents extend the wipe technology to bonded double layer substrates of contrasting textural properties. A rougher of the two sides may act as a gripping surface while the other may be used for delivering cleansing aids. The articles are described as being substantially dry defined as a Moisture Retention ratio of less than 0.95 gms. The ratio reports weight for total non-bound liquids in the article but is not synonymous with water content. Water levels are not defined.
Our evaluations of dry wipes produced by the known technology has indicated slow latherability. We attribute the problem to the relatively thick coating deposited onto the wipe substrate. Another probable source of the problem is the relatively low water content. A need exists for a cleansing wipe of improved foamability and one which can be efficiently manufactured.
Accordingly, it is an object of the present invention to provide a disposable, cleansing product which upon contact with water rapidly lathers and generates a rich long lasting foam.
Another object of the present invention is to provide a disposable cleansing product having a cleansing composition coatable onto a flexible wiping cloth in a process that minimizes foam generation during manufacture.
Still another object of the present invention is to provide a disposable cleansing product which may include an impregnated composition allowing for improved manufacturability, better aesthetics and increased latherability.
These and other objects of the present invention will become more apparent in light of the following summary and disclosure.
A substantially damp cleansing product is provided which includes:
(i) a water insoluble substrate; and
(ii) a cleansing composition impregnated onto the substrate including:
(a) at least one lathering surfactant present in an amount sufficient to foam;
(b) water; and
xe2x80x83wherein the water is present at greater than 15% by weight of the product, but no higher than about 40%, and the composition having a viscosity as measured on a Haake CV 20 Rheometer with 30 mm profiled parallel plates at 23xc2x0 C. ranging from about 50 to about 300,000 cp.
Now it has been discovered that there is a critical range of viscosity for the impregnated cleansing composition. Below a minimum viscosity, the composition foams poorly when the dry wipe is wetted with water by a consumer. Although not wishing to be bound by a theory, we believe the low viscosity compositions are readily washed away by water down the sink and unavailable for lathering. By contrast, a too high viscosity composition cannot be quickly activated with water for lathering by a consumer. There is a delay period.
Accordingly, the compositions of the present invention will have a viscosity ranging from about 50 to about 300,000 cp (centipoise). Thickness is measured on a Haake CV 20 Rheometer with 30 mm profiled parallel plates at 23xc2x0 C. A preferred viscosity range is from about 100 to about 250,000 cp, more preferably from about 150 to about 100,000, even more preferably from about 200 to about 50,000 cp, and optimally from about 400 to about 10,000 cp.
Another important discovery is the criticality of water levels. Substantially dry articles are poor at instantaneously generating a foam. Lathering surfactant cannot easily be activated at levels below 15% water. Some substantial amount of water must be present to allow the lathering surfactants to exit more rapidly from the substrate creating a foam. Minimum levels should be greater than 15%, preferably at least about 20%, more preferably at least about 25% by weight of the total cleansing product. These damp levels of water have the further advantage of giving pliability to the fabric substrate. A softer, more pleasant feel results.
Too much water should not be present. Large amounts of water impart a soggy poor aesthetic feel to the product. Even more significant, water encourages microbial growth. Much higher levels of preservatives are necessary with high water systems. Preservatives are not just a cost issue. Some consumers are hypoallergic to certain types of preservatives. Preserved systems must continuously be monitored to ensure that microbes have not mutated into strain resistant forms. Thus, maximum levels should be no higher than about 40% and preferably no higher than about 35% by weight of the cleansing product.
An essential element of compositions according to the present invention is that of a lathering surfactant. By a xe2x80x9clathering surfactantxe2x80x9d is meant a surfactant, which when combined with water and mechanically agitated generates a foam or lather. Preferably, these lathering surfactants should be mild, which means that they must provide sufficient cleansing or detersive benefits but not overly dry the skin or hair, and yet meet the lathering criteria described above.
The products of the present invention typically include at least one lathering surfactant in an amount from about 0.5% to about 60%, preferably from about 0.75% to about 40%, and more preferably from about 1% to about 20%, based on the weight of the impregnated composition.
A wide variety of lathering surfactants are useful herein and include those selected from the group consisting of anionic, nonionic, cationic, amphoteric and lathering surfactant mixtures thereof.
Among the anionic lathering surfactants useful herein are the following non-limiting examples which include the classes of:
(1) Alkyl benzene sulfonates in which the alkyl group contains from 9 to 15 carbon atoms, preferably 11 to 14 carbon atoms in straight chain or branched chain configuration. Especially preferred is a linear alkyl benzene sulfonate containing about 12 carbon atoms in the alkyl chain.
(2) Alkyl sulfates obtained by sulfating an alcohol having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms. The alkyl sulfates have the formula ROSO3xe2x88x92M+ where R is the C8-22 alkyl group and M is a mono- and/or divalent cation.
(3) Paraffin sulfonates having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms, in the alkyl moiety. These surfactants are commercially available as Hostapur SAS from Hoechst Celanese.
(4) Olefin sulfonates having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms. Most preferred is sodium C14-C16 olefin sulfonate, available as Bioterge AS 40(copyright)
(5) Alkyl ether sulfates derived from an alcohol having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms, ethoxylated with less than 30, preferably less than 12, moles of ethylene oxide. Most preferred is sodium lauryl ether sulfate formed from 2 moles average ethoxylation, commercially available as Standopol ES-2(copyright).
(6) Alkyl glyceryl ether sulfonates having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms, in the alkyl moiety.
(7) Fatty acid ester sulfonates of the formula: R1CH(SO3xe2x88x92M+)CO2R2 where R1 is straight or branched alkyl from about C8- to C18, preferably C12 to C16, and R2 is straight or branched alkyl from about C1 to C6, preferably primarily C1, and M+ represents a mono- or divalent cation.
(8) Secondary alcohol sulfates having 6 to 18, preferably 8 to 16 carbon atoms.
(9) Fatty acyl isethionates having from 10 to 22 carbon atoms, with sodium cocoyl isethionate being preferred.
(10) Dialkyl sulfosuccinates wherein the alkyl groups range from 3 to 20 carbon atoms each.
(11) Alkanoyl sarcosinates corresponding to the formula RCON(CH3)CH2CH2CO2M wherein R is alkyl or alkenyl of about 10 to about 20 carbon atoms and M is a water-soluble cation such as ammonium, sodium, potassium and trialkanolammonium. Most preferred is sodium lauroyl sarcosinate.
(12) Alkyl lactylates wherein the alkyl groups range from 8 to 12 carbon atoms, with sodium lauroyl lactylate sold as Pationic 138C(copyright) available from the Patterson Chemical Company as the most preferred.
(13) Taurates having from 8 to 16 carbon atoms, with cocoyl methyl taurate being preferred.
Nonionic lathering surfactants suitable for the present invention include C10-C20 fatty alcohol or acid hydrophobes condensed with from 2 to 100 moles of ethylene oxide or propylene oxide per mole of hydrophobe; C2-C10 alkyl phenols condensed with from 2 to 20 moles of alkylene oxides; mono- and di- fatty acid esters of ethylene glycol such as ethylene glycol distearate; fatty acid monoglycerides; sorbitan mono- and di-C8-C20 fatty acids; and polyoxyethylene sorbitan available as Polysorbate 80 and Tween 80(copyright) as well as combinations of any of the above surfactants.
Other useful nonionic surfactants include alkyl polyglucosides, saccharide fatty amides (e.g. methyl gluconamides) as well as long chain tertiary amine oxides. Examples of the latter category are: dimethylododecylamine oxide, oleyldi(2-hydroxyethyl)amine oxide, dimethyloctylamine oxide, dimethyldecylamine oxide, dimethyltetradecylamine oxide, di(2-ydroxyethyl)tetradecylamine oxide, 3-didodecyloxy-2-hydroxypropyldi(3-hydroxypropyl)amine oxide, and dimethylhexadecylamine oxide.
Amphoteric lathering surfactants useful for the present invention include aliphatic secondary and tertiary amines, preferably wherein the nitrogen is in a cationic state, in which the aliphatic radicals can be straight or branched chain and wherein one of the radicals contains an ionizable water solubilizing group such as carboxy, sulphonate, sulphate, phosphate or phosphonate. Illustrative substances are cocamidopropyl betaine, cocamphoacetate, cocamphodiacetate, cocamphopropionate, cocamphodipropionate, cocamidopropyl hydroxysultaine, cetyl dimethyl betaine, cocamidopropyl PG-dimonium chloride phosphate, coco dimethyl carboxymethyl betaine, cetyl dimethyl betaine and combinations thereof.
For purposes of the present invention, the total of all lathering surfactants to water may be in a weight ratio ranging from about 1:10 to about 5:1, preferably from about 1:4 to about 4:1, more preferably from about 1:3 to about 3:1, and optimally from about 1:2 to about 2:1.
A necessary element of the present invention is that of a water insoluble substrate. By xe2x80x9cwater insolublexe2x80x9d is meant the substrate does not dissolve or readily break apart upon immersion in water. A wide variety of materials can be used as the substrate. The following non-limiting characteristics are desirable: (i) sufficient wet strength for use, (ii) sufficient abrasivity, (iii) sufficient loft and porosity, (iv) sufficient thickness, and (v) appropriate size.
Non-limiting examples of suitable insoluble substrates which meet the above criteria include non-woven substrates, woven substrates, hydro-entangled substrates, air entangled substrates and the like. Preferred embodiments employ non-woven substrates since they are economical and readily available in a variety of materials. By non-woven is meant that the layer is comprised of fibers which are not woven into a fabric but rather are formed into a sheet, particularly a tissue. The fibers can either be random (i.e., randomly aligned) or they can be carded (i.e. combed to be oriented in primarily one direction). Furthermore, the non-woven substrate can be composed of a combination of layers of random and carded fibers.
Non-woven substrates may be comprised of a variety of materials both natural and synthetic. By natural is meant that the materials are derived from plants, animals, insects or byproducts. By synthetic is meant that the materials are obtained primarily from various man-made materials or from material that is usually a fibrous web comprising any of the common synthetic or natural textile-length fibers, or mixtures thereof.
Non-limiting examples of natural materials useful in the present invention are silk fibers, keratin fibers and cellulosic fibers. Non-limiting examples of keratin fibers include those selected from the group consisting of wool fibers, camel hair fibers, and the like. Non-limiting examples of cellulosic fibers include those selected from the group consisting of wood pulp fibers, cotton fibers, hemp fibers, jute fibers, flax fibers, and mixtures thereof.
Non-limiting examples of synthetic materials useful in the present invention include those selected from the group consisting of acetate fibers, acrylic fibers, cellulose ester fibers, modacrylic fibers, polyamide fibers, polyester fibers, polyolefin fibers, polyvinyl alcohol fibers, rayon fibers and mixtures thereof. Examples of some of these synthetic materials include acrylics such as Acrilan(copyright), Creslan(copyright), and the acrylonitrile-based fiber, Orion(copyright); cellulose ester fibers such as cellulose acetate, Arnel(copyright), and Acele(copyright); polyamides such as Nylons (e.g., Nylon 6, Nylon 66, and Nylon 610); polyesters such as Fortrel(copyright), Kodel(copyright), and Dacron(copyright); polyolefins such as polypropylene, polyethylene; polyvinyl acetate fibers and mixtures thereof.
Non-woven substrates made from natural materials consist of webs or sheets most commonly formed on a fine wire screen from a liquid suspension of the fibers.
Substrates made from natural materials useful in the present invention can be obtained from a wide variety of commercial sources. Non-limiting examples of suitable commercially available paper layers useful herein include Airtex(copyright), an embossed airlaid cellulosic layer having a base weight of about 71 gsy, available from James River Corporation, Green Bay, Wis.; and Walkisoft(copyright), an embossed airlaid cellulosic having a base weight of about 75 gsy, available from Walkisoft U.S.A., Mount Holly, N.C.
Non-woven substrates made from synthetic material useful in the present invention can also be obtained form a wide variety of commercial sources. Non-limiting examples of suitable non-woven layer materials useful herein include HFE-40-047, an apertured hydroentangled material containing about 50% rayon and 50% polyester, and having a basis weight of about 43 grams per square yard (gsy), available from Vertec, Inc., Walpole, Mass.; HEF 140-102, an apertured hydro-entangled material containing about 50% rayon and 50% polyester, and having a basis weight of about 56 gsy, available from Veratec, Inc., Walpole, Mass.; Novenet(copyright) 149-191, a thermo-bonded grid patterned material containing about 69% rayon, about 25% polypropylene, and about 6% cotton, and having a basis weight of about 100 gsy, available from Veratec, Inc., Walpole, Mass.; HEF Nubtex(copyright) 149-801, a nubbed, apertured hydro-entangled material, containing about 100% polyester, and having a basis weight of about 70 gsy, available from Veratec, Inc. Walpole, Mass.; Keybak(copyright) 951V, a dry formed apertured material, containing about 75% rayon, about 25% acrylic fibers, and having a basis weight of about 43 gsy, available from Chicopee Corporation, New Brunswick, N.J.; Keybak(copyright) 1368, an apertured material, containing about 75% rayon, about 5% polyester, and having a basis weight of about 39 gsy, available from Chicopee Corporation, New Brunswick, N.J.; Duralace(copyright) 1236, an apertured, hydro-entangled material, containing about 100% rayon, and having a basis weight from about 40 gsy to about 115 gsy, available from Chicopee Corporation, New Brunswick, N.J.; Duralace(copyright) 5904, an apertured, hydro-entangled material, containing about 100% polyester, and having a basis weight from about 40 gsy to about 115 gsy, available from Chicopee Corporation, New Brunswick, N.J.; Sontaro(copyright) 8868, a hydro-entangled material, containing about 50% cellulose and about 50% polyester, and having a basis weight of about 60 gsy, available from Dupont Chemical Corp.
Most preferred as a substrate for purposes of this invention are non-woven substrates, especially blends of rayon/polyester and ratios of 10:90 to 90:10, preferably ratios of 20:80 to 80:20, optimally 40:60 to 60:40 by weight. A most useful substrate is a 70:30 rayon/polyester non-woven wipe article.
Anywhere from 1 to 100, preferably from 5 to 50 single wipes may be stored within a dispensing pouch or container, preferably a moisture impermeable pouch or container. During storage and between dispensing, the pouch or container is preferably resealable. Single wipe containing pouches may also be employed.
The water insoluble substrates of the present invention can comprise two or more layers, each having a different texture and abrasiveness. The differing textures can result from the use of different combinations of materials or from the use of a substrate having a more abrasive side for exfoliation and a softer, absorbent side for gentle cleansing. In addition, separate layers of the substrate can be manufactured to have different colors, thereby helping the user to further distinguish the surfaces. Although the present invention may be suitable for substrates with two or more layers having different texture and abrasiveness, the best effectiveness of the damp system can be found with single or multiple layered substrates of identical construction.
The amount of impregnating composition relative to the substrate may range from about 20:1 to 1:20, preferably from 10:1 to about 1:10 and optimally from about 2:1 to about 1:2 by weight.
Impregnating compositions of the present invention may also include silicones of a volatile and non-volatile variety. Typical volatile silicones are the cyclomethicones commercially available as Dow Corning 244, 245, 344 and 345. Linear volatile dimethicones are also suitable. Non-volatile silicones include polydimethyl siloxanes of a viscosity greater than 2 centistoke and silicone copolyols also known as dimethicone copolyol for which Dow Corning 193 is a commercial source. Amounts of the silicones may range from about 0.01 to about 20, preferably from about 0.5 to about 3% by weight of the impregnated composition.
Cationic conditioning agents in monomeric and polymeric type are also useful for purposes of this invention. Examples of the polymeric type include: cationic cellulose derivatives, cationic starches, copolymers of a diallyl quaternary ammonium salt and an acrylamide, quaternized vinylpyrrolidone vinylimidazole polymers polyglycol amine condensates, quaternized collagen polypeptide, polyethylene imine, cationized silicon polymer (e.g. Amodimethicone), cationic silicon polymers provided in a mixture with other components under the trademark Dow Corning 929 (cationized emulsion), copolymers of adipic acid and dimethylaminohydroxypropyl diethylenetriamine, cationic chitin derivatives, cationized guar gum (e.g. Jaguar C-B-S, Jaguar C-17, Jaguar C-16 etc. manufactured by the Celanese Company), quaternary ammonium salt polymers (e.g. Mirapol A-15, Mirapol AD-1, Mirapol AZ-1, etc., manufactured by the Miranol Division of the Rhone Poulenc Company). Most preferred is polyquaternium-11 available as Luviquat(copyright) PQ 11 sold by the BASF Corporation.
Examples of monomeric cationic conditioning agents are salts of the general structure:
wherein R1 is selected from an alkyl group having from 12 to 22 carbon atoms, or aromatic, aryl or alkaryl groups having from 12 to 22 carbon atoms; R2, R3, and R4 are independently selected from hydrogen, an alkyl group having from 1 to 22 carbon atoms, or aromatic, aryl or alkaryl groups having from 12 to 22 carbon atoms; and Xxe2x88x92 is an anion selected from chloride, bromide, iodide, acetate, phosphate, nitrate, sulfate, methyl sulfate, ethyl sulfate, tosylate, lactylate, citrate, glycolate, and mixtures thereof. Additionally, the alkyl groups can also contain ether linkages, or hydroxy or amino group substituents (e.g. the alkyl groups can contain polyethylene glycol and polypropylene glycol moieties). Preferably the anion is phosphate, especially preferred is hydroxy ethyl cetyl dimonium phosphate available as Luviquat(copyright) Mono CP from the BASF Corporation.
Amino silicones quats may similarly be employed. Most preferred is Silquat AD designated by the CTFA as Silicone Quaternium 8, available from Siltech Inc.
Amounts of each cationic agent may range from about 0.05 to about 5%, preferably from about 0.1 to about 3%, optimally from about 0.3 to about 2.5% by weight of the impregnated composition.
Water-binding agents are preferably included in compositions of the present invention. Water soluble binding agents such as polyhydric alcohols are particularly preferred. Typical polyhydric alcohols include glycerol (also known as glycerin), polyalkylene glycols and more preferably alkylene polyols and their derivatives, including propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol and derivatives thereof, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1,3-butylene glycol, 1,2,6-hexanetriol, ethoxylated glycerol, propoxylated glycerol and mixtures thereof. For best results the water-binding agent is preferably glycerin. Also particularly preferred are polyethylene glycol (average molecular weight ranging from about 200 to about 2,000,000, with PEG-9M and PEG-14M being preferred) and hexylene glycol. In certain types of compositions the latter agent may be inappropriate and therefore polyols other than hexylene glycol should be utilized. The amount of water-binding agent may range anywhere from about 0.5 to about 50%, preferably between about 1 and about 30% by weight of the composition.
The disposable, single use personal care cleansing products of the present invention are manufactured by separately or simultaneously adding onto or impregnating into a water insoluble substrate the cleansing composition including lathering surfactants and conditioners, wherein the resulting product is substantially dry. By xe2x80x9cseparatelyxe2x80x9d is meant that the surfactants and the conditioners can be added sequentially, in any order without first being combined together. By xe2x80x9csimultaneouslyxe2x80x9d is meant that the surfactants and conditioners can be added at the same time, with or without first being combined together.
The surfactant, conditioners, water-binding agents and any other optional ingredients can be added onto or impregnated into the water insoluble substrate by any means known to those skilled in the art. For example, addition can be through spraying, laser printing, splashing, dipping, soaking, or coating.
Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material ought to be understood as modified by the word xe2x80x9caboutxe2x80x9d.
The term xe2x80x9ccomprisingxe2x80x9d is meant not to be limiting to any subsequently stated elements but rather to encompass non-specified elements of major or minor functional importance. In other words the listed steps, elements or options need not be exhaustive. Whenever the words xe2x80x9cincludingxe2x80x9d or xe2x80x9chavingxe2x80x9d are used, these terms are meant to be equivalent to xe2x80x9ccomprisingxe2x80x9d as defined above.
The following examples will more fully illustrate the embodiments of this invention. All parts, percentages and proportions referred to herein and in the appended claims are by weight unless otherwise illustrated.

Unilever Home and Personal Care USA, division of Conopco, Inc.