Automatic dishwashing compositions containing water soluble cationic surfactants are shown to reduce spotting and filming on plastic articles while reducing damage to the plastic articles.

The present disclosure is in the field of machine dishwashing. More specifically, the disclosure relates to automatic dishwashing detergents in granular, liquid, gel, solid and tablet form which contain a cationic, water soluble surfactant for the purpose of improving the final appearance of washed plastic articles.
Machine dishwashing detergents constitute a generally recognized distinct class of detergent compositions. In general, machine dishwashing detergents are mixtures of ingredients whose purpose, in combination, is to breakdown and remove food soils; to inhibit foaming caused by certain food soils; to promote the wetting of wash articles in order to minimize or eliminate visually observable spotting and filming; to remove stains such as might be caused by beverages such as coffee and tea or by vegetable soils such as carotenoid soils; to prevent a buildup of soil films on wash ware surfaces; and to reduce or eliminate tarnishing of flatware. It is particularly critical to a consumer""s perception of how well a machine dishwashing detergent performs that residual spotting and filming on wash articles be controlled or prevented entirely.
In conventional institutional and domestic dishwashing, a strongly alkaline solution is produced and used to wash dishes, glasses, and other cooking and eating utensils. One or more rinse cycles then follow this main wash cycle, in which any removed soil as well as the remaining detergent are expelled from the washing machine. A subsequent drying cycle may optionally be employed. Ordinary tap water can be used in preparing the strongly alkaline cleaning and rinse solutions, however, in European applications, this tap water is often treated (softened) to remove hardness ions such as calcium and magnesium with the result that hard water residues on washware are reduced. Nevertheless, spotting and filming from soil residues and precipitates can remain a problem, especially if the ion exchange unit serving the dishwashing machine is operating inefficiently. This problem can be minimized with a machine dishwashing composition containing a relatively high level of polyphosphate which acts to sequester hardness ions and to aid in soil removal and stabilization. In addition, these detergents usually contain a chlorine bleaching system for stain removal and for an added cleaning boost via oxidation of proteinaceous soils, thus helping to eliminate spotting on glassware.
Although the cleaning performance of these conventional detergent compositions is satisfactory, high phosphate levels, chlorine bleach, and high alkalinity have potential environmental and consumer drawbacks. As a result, an alternative technology was developed to deliver less alkaline products. Similarly, nonphosphated builders are substituted to further improve the environmental profile of the composition. As a consequence of the reduced cleaning efficiency of the modified composition, various detersive enzymes including amylolytic and proteolytic enzymes are included in the detergent composition in order to boost removal of starchy and proteinaceous soils, respectively. Because these enzymes are not compatible with chlorine bleach systems, an oxygen bleaching system can be substituted which can result in a reduction in bleach performance. Often, enzymatic compositions based on oxygen bleaches are formulated with a phosphate builder, in markets where local legislation will allow, to assure good overall performance. An unfortunate weakness in the performance of this alternative technology, both in formulations which are phosphated (i.e., containing inorganic phosphate builder salts) and those which are nonphosphated, is that they can often leave wash ware spotted or with a visible coating of film which is aesthetically unacceptable in both domestic and institutional environments. A consumers perception of residual spotting and filming can give rise to an unfavorable rating of an otherwise premium performing machine dishwashing product.
In order to substantially prevent the formation of spotting and filming, dedicated additives are included into the wash and/or rinse cycles of the washing machine. Preferably, dedicated rinse aids have commonly been added to the water used for performing the rinsing step(s). The precise mechanism through which rinse aids work is not established. One theory holds that a surfactant in the rinse aid is adsorbed on the washware surface at temperatures at or above its cloud point, and thereby reduces the solid/liquid interfacial energy and contact angle. This reduction leads to the formation of a continuous sheet which drains evenly from the surface and minimizes the formation of spots and film. The delivery of a similar sheeting action from the main wash has thus far proven very difficult.
Commonly available rinse aids have primarily focused on reducing spotting and filming on surfaces such as glass, ceramics, china, and metal. However, plastic washware is becoming more commonly used, especially in the institutional market. A special problem with plasticware is the possible chemical attack and crazing of the ware in the presence of certain components of the rinse aid or of the main wash detergent formulation. Many effective rinse aid components, such as fatty alcohol or alkyl phenol-based nonionic surfactants, also strongly attack plastic articles. The terms plasticware and plastic articles are defined herein to include articles composed of polycarbonate, melamine, polypropylene, polyester resin, polysulfone, and the like.
It is an object of the present disclosure to provide compositions, suitable for use in machine dishwashing methods, having the ability to provide excellent sheeting properties on plastic wash articles and so producing said articles which are aesthetically acceptable and free from spots and film. Further, such an acceptable plasticware appearance is achieved without endangering said articles due to attacking or crazing. Surprisingly, it has been discovered that a preferred embodiment of the present disclosure can deliver this appearance benefit from the main wash while at the same time maintaining an overall good cleaning performance towards soiled articles.
U.S. Pat. No. 5,298,289 describes the treatment and after-treatment of surfaces, especially metals, with derivatives of polyphenol compounds. These compositions are also said to be useful in treating plastic and painted surfaces to improve rinsability without water breaks. The surfactants employed are a combination of previously known anionic and nonionic surfactants.
European Patent Publication 0,432,836 describes the use of alkyl polyglycoside surfactants in rinse aid compositions on polycarbonate.
U.S. Pat. Nos. 5,880,088 and 5,880,089 discuss a rinse aid composition consisting, in part, of a polyalkylene oxide modified poly dimethylsiloxane or polybetaine modified polysiloxane surfactant, in combination with a fluorinated hydrocarbon surfactant. This composition is claimed to be compatible with plasticware.
The prior art is silent on the use of cationic surfactants in machine dishwashing formulations for the improvement of the final appearance of plastic washware.
It has now been discovered that a class of water soluble, cationic surfactants provide an unexpected and enhanced appearance benefit to plastic articles when incorporated in the dishwashing process, as evidenced, in part, by a reduction in the formation of spots and film on the washed articles. For a preferred class of water soluble, cationic surfactants, it has surprisingly also been discovered that this enhanced benefit is not accompanied by any compromise in the article durability due to chemically caused attack or crazing.
The essential surfactants may be incorporated at any point in the dishwashing process and have been found to improve the appearance of washed plastic articles. Thus, the surfactants may be incorporated into typical detergent or rinse aid formulations and in any desired form such as tablets, powders, granulates, pastes, liquids, and gels. Additionally, is has surprisingly been found that the final appearance benefit can be realized via incorporation in the main wash.
Preferably, the machine dishwashing detergents have:
a) an effective amount of a defined cationic, water soluble surfactant; and
b) an effective amount of a builder.
xe2x80x9cWater solublexe2x80x9d surfactants are, unless otherwise noted, herein defined to include solutes which, because of their molecular weight or chemical composition, are soluble to at least the extent of 0.01% by weight in distilled water at 25xc2x0 C. xe2x80x9cCationicxe2x80x9d surfactants herein include solutes in which at least one of the groups making up the chemical structure contains a cationic charge over a portion of the wash pH range of pH 6 to pH 11. Surfactants, as defined in xe2x80x9cPrinciples of Colloid and Surface Chemistryxe2x80x9d, by P. C. Hiemenz and R. Rajagopalan, are a particular class of solutes which show a dramatic effect on the surface tension of the solvent. Water soluble cationic surfactants are thus distinguished from water soluble cationic polymers in that the former are surface active and have a molecular weight which is typically about 1000 or below while the latter have a molecular weight well in excess of 1000 and do not dramatically affect the surface tension of water.
It is expected that the wash pH at which the preferred detergents would be employed would either naturally fall within the pH range 6-11 or, optionally, would be buffered in that range.
The compositions preferably contain a water soluble, cationic surfactant and a phosphate or nonphosphate builder.
When the compositions utilize a water-soluble phosphate builder, this builder preferably present at a level of from 1 to 90% by weight, preferably from 10 to 80% by weight, most preferably from 20 to 70% by weight of the composition. Specific examples of water-soluble phosphate builders are the alkali metal, ammonium and alkanol ammonium tripolyphosphates, sodium, potassium and ammonium pyrophosphate, sodium and potassium orthophosphate, sodium polymeta/phosphate in which the degree of polymerization ranges from about 6 to 21, and salts of phytic acid. Sodium or potassium tripolyphosphate is most preferred.
When the compositions utilize a water-soluble nonphosphate builder, this builder is preferably present at a level of from 1 to 90% by weight, preferably from 10 to 80% by weight, most preferably from 20 to 70% by weight of the composition. Suitable examples of non-phosphorus-containing inorganic builders include water-soluble alkali metal carbonates, bicarbonates, sesquicarbonates, borates, silicates, metasilicates, and crystalline and amorphous aluminosilicates. Specific examples include sodium carbonate (with or without calcite seeds), potassium carbonate, sodium and potassium bicarbonates, silicates including layered silicates and zeolites. A particularly preferred layered silicate is SKS-6 (available from Hoechst) although others such as SKS-5, SKS-7 and SKS-11 (also available from Hoechst), may also be used. U.S. Pat. No. 4,605,509 provides suitable examples of preferred aluminosilicates. Many useful aluminosilicates are commercially available and these may be crystalline or amorphous in nature. Preferred aluminosilicates include Zeolite A, Zeolite B, Zeolite MAP and Zeolite X. The particle size for these zeolitic materials should be in the preferred range of 0.1-10 microns diameter while individual particles may be even smaller than 0.1 microns so that a large surface area, which promotes exchange kinetics, is exposed. This large surface area also facilitates the role of zeolites in their role as surfactant carriers. This advantage of modifying zeolite and other builder morphology to most efficiently also serve as surfactant carriers can always be suitably exploited by those skilled in the art.
Organic detergent builders can also be used. These are typically, but are not restricted to, polycarboxylate materials. Polycarboxylate builders are those which have at least two carboxylate groups present in the compound and may be used either in the acidic form or as the neutralized soluble salt form. The alkali metal salts, such as lithium, sodium, and potassium or the ammonium or alkanol ammonium salts are the preferred forms. Within the class of polycarboxylate builders are various sub-classes of materials.
Citrate derived builders, preferably their soluble alkali metal salts, most preferably the sodium salt, are especially important with respect to machine dishwashing formulations. This importance is derived from their biodegradability and from their agricultural based availability. Malonates and dipicolinates are another subclass of builder materials.
Ether polycarboxylates are another important example of polycarboxylate builders. This class can be exemplified by the particularly preferred oxydisuccinate which has been revealed by Lamberti et. al. in U.S. Pat. No. 3,635,830 and by Berg et. al. in U.S. Pat. No. 3,128,287. Other examples of ether polycarboxylates include the xe2x80x9cTMS/TTDSxe2x80x9d builders disclosed in U.S. Pat. No. 4,663,071. Cyclic ether polycarboxylates as disclosed in U.S. Pat. Nos. 4,158,635; 4,120,874; 4,102,903; 3,923,679; and 3,835,163 are also builders which can be employed. Other classes of materials that fall into the category of ether polycarboxylates builders are the tartrate monoacetates, tartrate diacetates, oxydiacetates, tartrate monosuccinates, tartrate disuccinates and carboxymethyloxy succinates. 3,3-Dicarboxy-4-oxa-1,6-hexanedionates and the related compounds which are revealed in U.S. Pat. No. 4,566,984, mellitic acid and 3,5-dicarboxybenzoic acid are also suitable builders.
Another sub class of polycarboxylates are those derived by substitution onto an ammonia core or the aminopolycarboxylates. Examples within this class, but not restricted to, are ethylenediamine tetraacetates, methyl glycinediacetates and the particularly preferred nitrilotriacetates.
Builders derived from succinic acid are also useful in machine dishwashing formulations. Examples of these include the C5-C20 alkyl and alkenyl succinates. Particularly preferred examples of these are lauryl succinates (disclosed in European Patent Application 86200690) and 2-dodecenylsuccinate. Other non-limiting examples include myristyl-succinate, palmitylsuccinate and 2-pentadecenylsuccinate.
Polymeric polycarboxylates also serve as valuable building materials in machine dishwashing formulations. These include polycarboxylates such as polyacrylates, polymaleates, polyacetates, polyhydroxyacrylates, polyacrylatelpolymaleate and polyacrylate/ polymethacrylate copolymers, acrylate/maleate/vinyl alcohol terpolymers, and polyacetal carboxylates, and polyaspartates and mixtures thereof. Such carboxylates are described in U.S. Pat. Nos. 4,144,226, 4,146,495 and 4,686,062. Other examples of polymeric builders include oxidized starches and oxidized heteropolymeric polysaccharides. The acrylate/maleate copolymers and acrylate/maleate/vinyl alcohol terpolymers are especially preferred.
Simple fatty acid monocarboxylates, either in acid or salt form of the C12-C20 fatty acids, may be used either in conjunction with the other mentioned builders, esp. the succinates or tartarates, or alone to provide more building capacity. While such builders can act as antifoaming/defoaming systems, which is a desirable attribute in machine dishwashing formulations, they tend, under hard water conditions, to deposit residues on surfaces and hence are not preferred.
Organic builders that do not rely on the carboxylate functionality also exist and examples of these include the fatty acid sulfonates, phytates, phosphonates (see for e.g. U.S. Pat. Nos. 3,159,581; 3,213,030; 3,422,021, 3,400,148 and 3,422,137), alkanehydroxyphosphonates (e.g. Ethane-1-hydroxy-1,1-diphosphonate) and polyhydroxysulfonates (e.g. 3,5-dihydroxy-2,4,6-trisulfonic acid phenol),
Alkali metal citrates, nitrilotriacetates, oxydisuccinates, polyphosphonates organic builders. The citrates and oxydisuccinates can also be used in combinations with BRITESIL and/or layered silicates.
The foregoing detergent builders are meant to illustrate but not limit the types of builders that can be employed.
xe2x80x9cWater solublexe2x80x9d surfactants are, unless otherwise noted, herein defined to include solutes which, because of their molecular weight or chemical composition, are soluble to at least the extent of 0.01% by weight in distilled water at 25xc2x0 C. xe2x80x9cCationicxe2x80x9d surfactants herein comprise solutes in which at least one of the groups making up the chemical structure contains a cationic charge over a portion of the wash pH range of pH 6 to pH 11. xe2x80x9cSurfactantsxe2x80x9d, as defined in xe2x80x9cPrinciples of Colloid and Surface Chemistryxe2x80x9d, by P. C. Hiemenz and R. Rajagopalan, are a particular class of solutes which show a dramatic effect on the surface tension of the solvent. Water soluble cationic surfactants are thus distinguished from water soluble cationic polymers in that the former are surface active and have a molecular weight which is typically about 1000 or below while the latter have a molecular weight well in excess of 1000 and do not dramatically affect the surface tension of water.
It is expected that the wash pH at which the preferred detergents would be employed would either naturally fall within the range 6-11 or, optionally, would be buffered in that range.
Specifically, surfactants useful in this invention may be represented structurally as organic quatemary ammonium compounds as in formula I:
wherein R1 can generally be a straight, branched, or cyclic; saturated or unsaturated; substituted or unsubstituted group containing from about 6 to about 20 carbon atoms. R2, R3, and R4 can generally each independently be a straight, branched, or cyclic; saturated or unsaturated; substituted or unsubstituted group containing from about 1 to about 10 carbon atoms or a poly oxyalkene condensate of about 1 to about 25 oxyalkene units. It is understood that two of R2, R3, and R4 may be taken together with the nitrogen group to which they are attached to form an aliphatic or aromatic heterocycle as in derivatives of pyrrole, pyrrolidone, or piperidine. Similarly, it is understood that R2, R3, and R4 may be taken together with the nitrogen group to which they are attached to form an aromatic heterocycle as in derivatives of pyridine. X is an anion chosen from chloride, iodide, bromide, methyl sulfate, ethyl sulfate, sulfate and the like.
In a preferred embodiment of the present invention, R1 is a linear, saturated group containing from about 6 to about 20 carbon atoms, R2 is a linear, saturated group containing from about 1 to about 2 carbon atoms, R3 is a linear, saturated group containing from about 1 to about 2 carbon atoms or is a poly oxyethene condensate given by the general formula:
xe2x80x94(CH2CH2O)mHxe2x80x83xe2x80x83(II)
and R4 is a linear, saturated group containing from about 1 to about 2 carbon atoms or is a poly oxyethene condensate given by the general formula:
xe2x80x94(CH2CH2O)nHxe2x80x83xe2x80x83(III)
with the understanding that the integers m and n are such that their sum is from about 3 to about 40 and with the stipulation that one of R3 or R4 must be a poly oxyethene condensate. X is an anion chosen from chloride, iodide, bromide, methyl sulfate, ethyl sulfate, sulfate and the like.
Examples of preferred cationic surfactants include, but are not limited to, methyl bis-(polyethoxy ethanol) coco ammonium chloride, methyl bis-(2-hydroxyethyl) coco ammonium chloride, and methyl bis-(polyethoxy ethanol) tallow ammonium chloride. These materials are provided by the witco Corporation under the trade names Rewoquat CPEM, Variquat 638, and as the experimental compound DPSC 287-21, respectively.
In a particularly preferred embodiment, R1 is a linear, predominately saturated group containing primarily from about 8 to about 18 carbon atoms, as would be found in derivatives from tallow or coconut oil, R2 is a methyl or an ethyl radical, R3 is a methyl or an ethyl radical or is a poly oxyethene condensate given by the general formula:
xe2x80x83xe2x80x94(CH2CH2O)mHxe2x80x83xe2x80x83(II)
and R4 is a methyl or an ethyl radical or is a poly oxyethene condensate given by the general formula:
xe2x80x94(CH2CH2O)nHxe2x80x83xe2x80x83(III)
with the understanding that the integers m and are such that their sum is from about 10 to about 20 and with the stipulation that one of R3 or R4 must be a poly oxyethene condensate. It has been found that if the sum of m and n are less than about 10, the disclosed benefits decrease. X is an anion chosen from chloride, iodide, bromide, methyl sulfate, ethyl sulfate, sulfate and the like.
Examples of cationic surfactants comprising the particularly preferred embodiment include, but are not limited to, methyl bis-(polyethoxy ethanol) coco ammonium chloride and ethyl bis-(polyethoxy ethanol) tallow ammonium chloride. These materials are provided by the Witco Corporation under the trade names Variquat K-1215 and Adogen 66, respectively.
An effective amount of said cationic-surfactant is 0.1 to 20%, preferably 0.5 to 10%, most preferably 1 to 5%, all by weight, of the total detergent formulation.
In addition to the essential ingredients described herein above, the presently disclosed compositions may be formulated as detergent compositions having conventional ingredients, preferably selected from enzymes, buffering systems, oxygen bleaching systems, surfactants, heavy metal ion sequestrants, antiscalants, corrosion inhibitors, and antifoams.
Enzymes capable of facilitating the removal of soils from a substratexe2x80x94detersive enzymesxe2x80x94may also be present in a combined amount of up to about 10% by weight of active enzyme. Such enzymes include proteases, amylases, lipases, esterases, cellulases, pectinases, lactases and peroxidases as conventionally incorporated into detergent compositions. While compositions with single enzymes may be used it is highly preferred for machine dishwashing formulations to use combinations of two or more enzymes. Furthermore, since most formulations contain oxidative bleaches, enzymes, especially amylases and proteases, which have been engineered to have improved bleach stability are highly preferred. Such engineering of enzymes is known (see for e.g. J. Biol. Chem. 260, 11, 1985, 6518-6521).
While enzymes may be derived from yeast, fungal, bacterial, animal or vegetable origin, the choice of which one to use is really determined by finding the most suitable intersection of the optima with respect to activity v/s pH, and stability to heat, bleach and other functional ingredients (e.g. surfactants, builders etc.) present in the formulation. It is known that with respect to such selection criteria bacterial proteases and amylases and fungal cellulases are preferred.
Examples of proteases include Alcalase(copyright), Savinase(copyright) and Esperase(copyright) from Novo Industries A/S; Purafect OxP(copyright), ex. Genencor; and Maxatase(copyright) from International BioSynthetics Inc. Other examples of proteases include Protease A and Protease B as disclosed in European Patent Application 130,756 published Jan. 9 1985 and the proteases disclosed in U.S. Pat. Nos. 5,677,272 and 5,679,630. The proteases Alcalase and Savinase are preferred enzymes.
Examples of amylases include Termamyl(copyright) and Duramyl(copyright) from Novo Industries A/S; Purafect OxAm(copyright), from Genencor Int. and Rapidase(copyright) from International BioSynthetics Inc and amylases such as those described in British Patent Specification No. 1,296,839. The amylases Termamyl and Duramyl are preferred. Amylase variants produced by site directed mutagenesis of precursor amylases which are currently available and which have increased stability, relative to current references such as Termamyl in one or more properties such as temperature stability, especially at wash temperatures of 45-75xc2x0 C.; alkaline stability, especially at wash pH values of 8.5-11 and oxidative stability, especially in the presence of environments containing peracids are especially preferred. Examples of such stability enhanced amylases are disclosed in WO/94/02597 wherein variants of precursor enzymes such as Termamyl(copyright) have been disclosed.
The use of lipase enzymes in ADD formulations is known in the art as disclosed in U.S. Pat. No. 5,719,112. Commercial examples of lipases include Lipolase(copyright)xe2x80x94derived from Humicola lanuginosaxe2x80x94from Novo Industries A/S, Amano-CES from Toyo Jozo Co., Tagata, Japan, and lipases derived from Chromobacter viscosum available from U.S. Biochemical Corp., U.S.A and Diosynth Co., The Netherlands. Lipolase(copyright) and variants of lipases from Humicola lanuginosa as disclosed in WO92/05249 are preferred.
Cellulases such as those disclosed in U.S. Pat. No. 4,435,307, GB-A-2,075,028 and GB-A-2,095,275 may also be included in the instant invention. The commercially available Carezyme(copyright) from Novo Industries A/S is especially preferred.
The relatively fragile nature of enzymes necessitates the use of techniques to stabilize them from other reactive species present in the composition or under in-use conditions. Such techniques have been revealed in U.S. Pat. Nos. 3,600,319; 3,519,570 and in Eur. Pat. Application No. 0 199 405. Means for incorporating enzymic materials into detergent compositions are disclosed in U.S. Pat. No. 3,553,139.
The buffering system may be present in order to deliver a pH of about 6 to about 11 in the wash water. A controlled pH profile during the entire wash cycle allows for maximum efficiency to be obtained from the various cleaning agents such as enzymes, bleaches and surfactants. Soils are naturally acidic and their presence will tend to lower the intrinsic pH of the wash solution. Resistance to such undesirable pH fluctuations are achieved by the use of buffering agents. The preferred pH range of aqueous solutions of machine dishwashing formulations is 6.5-11 with the particularly preferred range being from 7.0-10.5. The pH delivery and buffering in the system can be provided by various ingredients which can be selected from water-soluble alkali metal (a) carbonates, bicarbonates and/or sesquicarbonatesxe2x80x94(b) citrates (c) hydroxides (d) borates (esp. borax) (e) silicates (f) crystalline and amorphous aluminosilicates (g) phytic acid and mixtures or combinations of (a)-(g).
Nonlimiting examples within the class of materials designated silicates include sodium silicate, sodium metasilicate and layered silicates such as those described in U.S. Pat. No. 4,664,839 which are comprised of SiO2:Na2O ratios in the range of 1.6:1 to 3.2:1. Commercially available layered silicates include NaSKS-5(copyright), NaSKS-6(copyright), NaSKS-7(copyright), and NaSKS-11(copyright), all from Hoechst. Other silicates commerically available include the BRITESIL(copyright) H20 AND BRITESIL(copyright) H24 from PQ Corp. Silicates are normally incorporated in at levels where they do not negatively impact the spotting and filming performance of the machine dishwashing formulation.
Particularly preferred options are sodium and potassium carbonate, sodium and potassium bicarbonates, sodium citrate, borax, sodium metasilicate and the silicates BRITESIL(copyright) H20 and NaSKS-6(copyright) as well as binary combinations of sodium citrate and sodium carbonate.
Other ingredients added into the formulation for improved building and sequestration can also serve the role of a primary and/or supplementary buffering agent. These include, in a non limiting list of examples, ethylenediamine tetraacetates, nitrilotriacetates, tartarate monosuccinates, tartarate disuccinates, oxydisuccinates, carboxymethoxysuccinates and sodium benzene polycarboxylate salts.
Other techniques for controlling pH such as pH jump systems, and the use of dual compartments have been previously disclosed and are well known in the art.
In certain cases it may be advantageous to have a controlled change of the pH during the wash cycle and techniques such as the delayed release of acidity as disclosed in U.S. Pat. No. 5,747,438 or the use of enzymatic systems to provide delayed release of alkalinity such as those disclosed in WO 9736984 are known to those skilled in the art. Such practices are not excluded from the present disclosure.
The following are preferred oxygen bleach sources:
Peroxy Bleaching Agentsxe2x80x94The oxygen bleaching agents of the compositions include organic peroxy acids and diacylperoxides. Typical monoperoxy acids useful herein include alkyl peroxy acids and aryl peroxy acids such as:
i) peroxybenzoic acid and ring-substituted peroxybenzoic acids, e.g., peroxy-alpha-naphthoic acid, and magnesium monoperoxyphthalate
ii) aliphatic and substituted aliphatic monoperoxy acids, e.g., peroxylauric acid, peroxystearic acid, epsilon-phthalimido-peroxyhexanoic acid and o-carboxybenzamido peroxyhexanoic acid, N-nonylamidoperadipic acid and N-nonylamidopersuccinic acid.
iii) Cationic peroxyacids such as those described in U.S. Pat. Nos. 5,422,028, 5,294,362; and 5,292,447, are herein incorporated by reference.
iv) Sulfonyl peroxyacids such as compounds described in U.S. Pat. No. 5,039,447 (Monsanto Co.), herein incorporated by reference.
Typical diperoxy acids useful herein include alkyl diperoxy acids and aryl diperoxy acids, such as:
v) 1,12-diperoxydodecanedioic acid
vi) 1,9-diperoxyazelaic acid
vii) diperoxybrassylic acid; diperoxysecacic acid and diperoxy-isophthalic acid
viii) 2-decyldiperoxybutan-1,4-dioic acid
ix) N,N1-terephthaloyl-di(6-aminopercaproic acid).
A typical diacylperoxide useful herein includes dibenzoylperoxide.
Inorganic peroxygen compounds are also suitable. Examples of these materials are salts of monopersulfate (available commercially as the trisalt Oxone(copyright) from Dupont Chem. Co.), perborate monohydrate, perborate tetrahydrate, percarbonate, pyrophosphate peroxyhydrate, urea peroxyhydrate, and sodium peroxide and mixtures thereof. Sodium perborate monohydrate and sodium percarbonate are particularly preferred.
Preferred peroxy bleaching agents include epsilon-phthalimido-peroxyhexanoic acid, o-carboxybenzamidoperoxyhexanoic acid, and mixtures thereof.
The organic peroxy acid is present in the composition in an amount such that the level of organic peroxy acid in the wash solution is about 1 ppm to about 300 ppm AvOx, preferably about 2 ppm to about 200 ppm AvOx.
The oxygen bleaching agent may be incorporated directly into the formulation or may be encapsulated by any number of encapsulation techniques.
A preferred encapsulation method is described in U.S. Pat. No. 5,200,236 issued to Lang et al., herein incorporated by reference. In the patented method, the bleaching agent is encapsulated as a core in a paraffin wax material having a melting point from about 40xc2x0 C. to 50xc2x0 C. The wax coating has a thickness of from 100 to 1500 microns.
Bleach Precursorsxe2x80x94Suitable peracid precursors for peroxy bleach compounds have been amply described in the literature, These include, but are not limited to, those referenced in GB Nos. 836,988; 855,735; 907,356; 907,358; 907,950; 1,003,310 and 1,246,339; U.S. Pat. Nos. 3,332,882; 4,128,494; 4,412,934; 4,634,551 and 4,915,854 and WO 96/16155.
Typical examples of precursors are polyacylated alkylene diamines, such as N,N,Nxe2x80x2,Nxe2x80x2-tetraacetylethylene diamine (TAED) and N,N,Nxe2x80x2,Nxe2x80x2-tetraacetylmethylene diamine (TAMD); acylated glycolurils, such as tetraacetylglycoluril (TAGU); xylose tetraacetate, glucose pentaacetate, triacetylcyanurate, sodium sulfophenyl ethyl carbonic acid ester, sodium acetyloxybenene sulfonate (SABS), sodium nonanoyloxy benzene sulfonate (SNOBS) and choline sulfophenyl carbonate. Peroxybenzoic acid precursors are known in the art, e.g., as described in GB-A-836,988. Examples of suitable precursors are phenylbenzoate; phenyl p-nitrobenzoate; o-nitrophenyl benzoate; o-carboxyphenyl benzoate; p-bromophenylbenzoate; sodium or potassium benzoyloxy benzene-sulfonate; and benzoic anhydride.
Another class of bleach activators are the benzoxazin derivatives as have been disclosed in U.S. Pat. No. 4,966,723.
U.S. Pat. No. 4,634,551 discloses a class of precursor compounds which upon perhydrolysis lead to the formation of peracids containing amide groups within their structure. Examples of such precursors include, in a non limiting sense, (6-octanamido-caproyl)oxybenzenesulfonate, (6-nonanamido-caproyl)oxybenzenesulfonate and (6-decanamido-caproyl)oxybenzenesulfonate. Mixtures of such compounds also constitute suitable precusors. Another class of precursor molecules are the acyl lactams such as the acyl valerolactams and the acyl caprolactams. The acyl substituent on these lactam derivatives can be an alkyl, aryl, alkaryl, or alkoxyaryl, containing from about 1 to 12 carbon atoms or substituted phenyl groups containing 6 to 18 carbon atoms. Examples of such acyl groups non limitingly include benzoyl, octanoyl, nonanoyl, decanoyl, undecenoyl, and 3,5,5-trimethylhexanoyl. U.S. Pat. No. 4,545,784 reveals acylcaprolactams adsorbed onto sodium perborate.
Quaternary substituted bleach precursors are also well known in the art. Examples of such compounds have been disclosed in U.S. Pat. Nos. 5,686,015; 5,269,962; 5,106,528; 5,093,022; 4,988,451; 4,904,406; 4,818,426; 4,397,757; 4,283,301 as well as in British Pat. 1,382,594 and in EP 552,812 A1; EP 475,512; EP 458,396 and EP 284,292.
Other types of bleach precursors, some multiply substituted and others with cationic groups have been revealed in U.S. Pat. Nos. 5,560,862; 5,584,888 and 5,460,747.
U.S. Pat. No. 5,753,138 teaches on the use of bleach precursors which are effective at low concentrations of perhydroxide while U.S. Pat. No. 5,739,096 teaches about the use of cyanopyridine N-oxides as bleach activators.
Preferred peroxygen bleach precursors are sodium p-benzoyloxybenzene sulfonate, N,N,Nxe2x80x2,Nxe2x80x2-tetraacetylethylene diamine, sodium nonanoyloxybenzene sulfonate and choline sulfophenyl carbonate.
The peroxygen bleach precursors are preferably present in the composition in an amount from about 1 to about 20 weight percent, preferably from about 1 to about 15 wt. %, most preferably from about 2 to about 15 wt. %. To deliver a functional peroxygen bleach from a precursor, a source of hydrogen peroxide is required. The hydrogen peroxide source is preferably a compound that delivers hydrogen peroxide on dissolution. Preferred sources of hydrogen peroxide are sodium perborate, either as the mono- or tetrahydrate and sodium percarbonate. The source of hydrogen peroxide, when included in these compositions is present at a level of about 1% to about 40% by weight, preferably from about 2% to about 30% by weight, most preferably from about 4% to about 25% by weight.
Bleach Catalystxe2x80x94An effective amount of a bleach catalyst can also be present in the invention. A number of organic catalysts are available such as the activated imines as described in U.S. Pat. Nos. 5,753,599; 5,693,603; 5,041,232; 5,047,163 and 5,463,115 and those containing quatemary imine salts as described in U.S. Pat. No. 5,550,256 and 5,482,515. Another class of organic bleach catalysts are the dioxiranes as have been disclosed in U.S. Pat. Nos. 5,755,993; 5,525,121 and 3,822,114.
Transition metal bleach catalysts are also useful, especially those based on manganese, iron, cobalt, titanium, molybdenum, nickel, chromium, copper, ruthenium, tungsten and mixtures thereof. These include simple water-soluble salts such as those of iron, manganese and cobalt as well as catalysts containing complex ligands.
The German patent DE1,529,905 teaches on the use of diimine complexes of manganese, iron, cobalt, ruthenium or molybdenum as bleach catalysts.
Suitable examples of manganese catalysts containing organic ligands are described in U.S. Pat. No. 4,728,455, U.S. Pat. No. 5,114,606, U.S. Pat. No. 5,153,161, U.S. Pat. No. 5,194,416, U.S. Pat. No. 5,227,084, U.S. Pat. No. 5,244,594, U.S. Pat. No. 5,246,612, U.S. Pat. No. 5,246,621, U.S. Pat. No. 5,256,779, U.S. Pat. No. 5,274,147, U.S. Pat. No. 5,280,117 and European Pat. App. Pub. Nos. 544,440, 544,490, 549,271 and 549,272. Preferred examples of these catalysts include MnIV2(u-O)2(1,4,7-trimethyl-1,4,7-triazacyclononane)2(PF6)2, MnIII2(u-O)1(u-OAc)2(1,4,7-trimethyl-1,4,7-triazacyclononane)2(ClO4)2, MnIV4(u-O)1(1,4,7-triazacyclononane)4(ClO4)4, MnIIIMnIV4(u-O)1(u-OAc)2(1,4,7-trimethyl-1,4,7-triazacyclononane)2(ClO4)3, MnIV(1,4,7-trimethyl-1,4,7-triazacyclononane)-(OCH3)3(PF6), and mixtures thereof. Other metal-based bleach catalysts include those disclosed in U.S. Pat. No. 4,430,243 and U.S. Pat. No. 5,114,611.
Iron and manganese salts of aminocarboxylic acids in general are useful herein including iron and manganese aminocarboxylate salts disclosed for bleaching in the photographic color processing arts. A particularly useful transition metal salt is derived from ethylenediaminedisuccinate and any complex of this ligand with iron or manganese.
Another type of bleach catalyst, as disclosed in U.S. Pat. No. 5,114,606, is a water soluble complex of manganese (II), (III), and/or (IV) with a ligand which is a non-carboxylate polyhydroxy compound having at least three consecutive Cxe2x80x94OH groups. Preferred ligands include sorbitol, iditol, dulsitol, mannitol, xylithol, arabitol, adonitol, meso-erythritol, meso-inositol, lactose and mixtures thereof. Especially preferred is sorbitol.
U.S. Pat. No. 5,114,611 teaches a bleach catalyst comprising a complex of transition metals, including manganese, cobalt, iron or copper with a non-(macro)-cyclic ligand. Other examples include Mn gluconate, Mn(CF3SO3)2, and binuclear Mn complexed with tetra-N-dentate and bi-N-dentate ligands, including [bipy2MnIII(u-O)2MnIVbipy2]-(ClO4)3.
Other bleach catalysts are described, for example, in European Pat. App. Pub. Nos. 408,131 (cobalt complexes), 384,503 and 306,089 (metallo-porphyrins), U.S. Pat. No. 4,728,455 (manganese/multidenate ligand), U.S. Pat. No. 4,711,748 (absorbed manganese on aluminosilicate), U.S. Pat. No. 4,601,845 (aluminosilicate support with manganese, zinc or magnesium salt), U.S. Pat. No. 4,626,373 (manganese/ligand), U.S. Pat. No. 4,119,557 (ferric complex), U.S. Pat. No. 4,430,243 (chelants with manganese cations and non-catalytic metal cations), and U.S. Pat. No. 4,728,455 (manganese gluconates).
Useful catalysts based on cobalt are described in Pat. App. Pub. Nos. WO 96/23859, WO 96/23860 and WO 96/23861 and U.S. Pat. Nos. 5,559,261 and 5,703,030. WO 96/23860 describes cobalt catalysts of the type [ConLmXp]zYz, where L is an organic ligand molecule containing more than one heteroatom selected from N, P, O and S; X is a coordinating species; n is preferably 1 or 2; m is preferably 1 to 5; p is preferably 0 to 4 and Y is a counterion. One example of such a catalyst is N,Nxe2x80x2-Bis(salicylidene)ethylenediaminecobalt (II). Other cobalt catalysts described in these applications are based on Co(III) complexes with ammonia and mon-, bi-, tri- and tetradentate ligands such as [Co(NH3)5OAc]2+ with Clxe2x88x92, OAcxe2x88x92, PF6xe2x88x92, SO4=, and BF4xe2x88x92 anions.
Certain transition-metal containing bleach catalysts can be prepared in situ by the reaction of a transition-metal salt with a suitable chelating agent, for example, a mixture of manganese sulfate and ethylenediaminedisuccinate. Highly colored transition metal-containing bleach catalysts may be co-processed with zeolites to reduce the color impact.
When present, the bleach catalyst is typically incorporated at a level of about 0.0001 to about 10% by wt., preferably about 0.001 to about 5% by weight.
Optionally, a surfactant selected from the list including anionic, nonionic, cationic, amphoteric, and zwifteronic surfactants and mixtures of these surface active agents may be included in the machine dishwashing formulation. Such surfactants are well known in the detergent arts and are described at length in xe2x80x9cSurface Active Agents and Detergentsxe2x80x9d, Vol. 2 by Schwartz, Perry and Birch, Interscience Publishers, Inc., 1959, herein incorporated by reference.
Preferred surfactants are one or a mixture of:
Anionic surfactantsxe2x80x94Anionic synthetic detergents can be broadly described as surface active compounds with one or more negatively charged functional groups. An important class of anionic compounds are the water-soluble salts, particularly the alkali metal salts, of organic sulfur reaction products having in their molecular structure an alkyl radical containing from about 6 to 24 carbon atoms and a radical selected from the group consisting of sulfonic and sulfuric acid ester radicals.
Primary Alkyl Sulfates
R7OSO3M
where R7 is a primary alkyl group of 8 to 18 carbon atoms and M is a solubilizing cation. The alkyl group R7 may have a mixture of chain lengths. It is preferred that at least two-thirds of the R7 alkyl groups have a chain length of 8 to 14 carbon atoms. This will be the case if R7 is coconut alkyl, for example. The solubilizing cation may be a range of cations which are in general monovalent and confer water solubility. An alkali metal, notably sodium, is especially envisaged. Other possibilities are ammonium and substituted ammonium ions, such as trialkanolammonium or trialkylammonium.
Alkyl Ether Sulfates
R7O(CH2CH2O)nSO3M
where R7 is a primary alkyl group of 8 to 18 carbon atoms, n has an average value in the range from 1 to 6 and M is a solubilizing cation. The alkyl group R7 may have a mixture of chain lengths. It is preferred that at least two-thirds of the R7 alkyl groups have a chain length of 8 to 14 carbon atoms. This will be the case if R7 is coconut alkyl, for example. Preferably n has an average value of 2 to 5.
Fatty Acid Ester Sulfonates
R8CH(SO3M)CO2R9
where R8 is an alkyl group of 6 to 16 atoms, R9 is an alkyl group of 1 to 4 carbon atoms and M is a solubilizing cation. The group R8 may have a mixture of chain lengths. Preferably at least two-thirds of these groups have 6 to 12 carbon atoms. This will be the case when the moiety R8CH(-)CO2(-) is derived from a coconut source, for instance. It is preferred that R9 is a straight chain alkyl, notably methyl or ethyl.
Alkyl Benzene Sulfonates
R10ArSO3M
where R10 is an alkyl group of 8 to 18 carbon atoms, Ar is a benzene ring (C6H4) and M is a solubilizing cation. The group R10 may be a mixture of chain lengths. Straight chains of 11 to 14 carbon atoms are preferred.
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. Olefin sulfonates having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms. U.S. Pat. No. 3,332,880 contains a description of suitable olefin sulfonates.
Organic phosphate based anionic surfactants include organic phosphate esters such as complex mono- or diester phosphates of hydroxyl-terminated alkoxide condensates, or salts thereof. Included in the organic phosphate esters are phosphate ester derivatives of polyoxyalkylated alkylaryl phosphate esters, of ethoxylated linear alcohols and ethoxylates of phenol. Also included are nonionic alkoxylates having a sodium alkylenecarboxylate moiety linked to a terminal hydroxyl group of the nonionic through an ether bond. Counterions to the salts of all the foregoing may be those of alkali metal, alkaline earth metal, ammonium, alkanolammonium and alkylammonium types.
Particularly preferred anionic surfactants are the fatty acid ester sulfonates with formula:
R8CH(SO3M)CO2R9
where the moiety R8CH(-)CO2(-) is derived from a coconut source and R9 is either methyl or ethyl; primary alkyl sulfates with the formula:
R7OSO3M
wherein R7 is a primary alkyl group of 10 to 18 carbon atoms and M is a sodium cation; and paraffin sulfonates, preferably with 12 to 16 carbon atoms to the alkyl moiety.
Nonionic surfactantsxe2x80x94Nonionic surfactants can be broadly defined as surface active compounds with one or more uncharged hydrophilic substituents. A major class of nonionic surfactants are those compounds produced by the condensation of alkylene oxide groups with an organic hydrophobic material which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements. Illustrative, but not limiting examples, of various suitable nonionic surfactant types are:
polyoxyalkene condensates of aliphatic carboxylic acids, whether linear- or branched-chain and unsaturated or saturated, especially ethoxylated and/or propoxylated aliphatic acids containing from about 8 to about 18 carbon atoms in the aliphatic chain and incorporating from about 2 to about 50 ethylene oxide and/or propylene oxide units. Suitable carboxylic acids include xe2x80x9ccoconutxe2x80x9d fatty acids (derived from coconut oil) which contain an average of about 12 carbon atoms, xe2x80x9ctallowxe2x80x9d fatty acids (derived from tallow-class fats) which contain an average of about 18 carbon atoms, palmitic acid, myristic acid, stearic acid and lauric acid.
polyoxyalkene condensates of aliphatic alcohols, whether linear- or branched-chain and unsaturated or saturated, especially ethoxylated and/or propoxylated aliphatic alcohols containing from about 6 to about 24 carbon atoms and incorporating from about 2 to about 50 ethylene oxide and/or propylene oxide units. Suitable alcohols include xe2x80x9ccoconutxe2x80x9d fatty alcohol, xe2x80x9ctallowxe2x80x9d fatty alcohol, lauryl alcohol, myristyl alcohol and oleyl alcohol.
Ethoxylated fatty alcohols may be used alone or in admixture with anionic surfactants, especially the preferred surfactants above. The average chain lengths of the alkyl group R11 in the general formula:
R11O(CH2CH2O)nH
is from 6 to 20 carbon atoms. Notably the group R11 may have chain lengths in a range from 9 to 18 carbon atoms.
The average value of n should be at least 2. The numbers of ethylene oxide residues may be a statistical distribution around the average value. However, as is known, the distribution can be affected by the manufacturing process or altered by fractionation after ethoxylation. Particularly preferred ethoxylated fatty alcohols have a group R11which has 9 to 18 carbon atoms while n is from 2 to 8.
Also included within this category are nonionic surfactants having a formula:
wherein R12 is a linear alkyl hydrocarbon radical having an average of 6 to 18 carbon atoms, R13 and R14 are each linear alkyl hydrocarbons of about 1 to about 4 carbon atoms, x is an integer of from 1 to 6, y is an integer of from 4 to 20 and z is an integer from 4 to 25.
One preferred nonionic surfactant of the above formula is Poly-Tergent SLF-18 a registered trademark of the Olin Corporation, New Haven, Conn. having a composition of the above formula where R12 is a C6-C10 linear alkyl mixture, R13 and R14 are methyl, x averages 3, y averages 12 and z averages 16. Another preferred nonionic surfactant is:
wherein R15 is a linear, aliphatic hydrocarbon radical having from about 4 to about 18 carbon atoms including mixtures thereof; and R16 is a linear, aliphatic hydrocarbon radical having from about 2 to about 26 carbon atoms including mixtures thereof; j is an integer having a value of from 1 to about 3; k is an integer having a value from 5 to about 30; and l is an integer having a value of from 1 to about 3. Most preferred are compositions in which j is 1, k is from about 10 to about 20 and l is 1. These surfactants are described in WO 94/22800. Other preferred nonionic surfactants are linear fatty alcohol alkoxylates with a capped terminal group, as described in U.S. Pat. No. 4,340,766 to BASF. Particularly preferred is Plurafac LF403 ex. BASF.
Another nonionic surfactant included within this category are compounds of formula:
R17xe2x80x94(CH2CH2O)qH
wherein R17 is a C6-C24 linear or branched alkyl hydrocarbon radical and q is a number from 2 to 50; more preferably R17 is a C8-C18. linear alkyl mixture and q is a number from 2 to 15.
polyoxyethylene or polyoxypropylene condensates of alkyl phenols, whether linear- or branched-chain and unsaturated or saturated, containing from about 6 to 12 carbon atoms and incorporating from about 2 to about 25 moles of ethylene oxide and/or propylene oxide.
polyoxyethylene denvadives of sorbitan mono-, di-, and tri-fatty acid esters wherein the fatty acid component has between about 12 and about 24 carbon atoms. The preferred polyoxyethylene derivatives are of sorbitan monolaurate, sorbitan trilaurate, sorbitan monopalmitate, $orbitan tripalmitate, sorbitan monostearate, sorbitan monoisostearate, sorbital tristearate, sorbitan monooleate, and sorbitan trioleate. The polyoxyethylene chains may contain between about 4 and about 30 ethylene oxide units, preferably about 10 to about 20. The sorbitan ester derivatives contain 1, 2 or 3 polyoxyethylene chains dependent upon whether they are mono-, di- or tn-acid esters.
polyoxyethylene-polyoxypropylene block copolymers having formula:
HO(CH2CH2O)a(CH(CH3)CH2O)b(CH2CH2O)cH
or
HO(CH(CH3)CH2O)d(CH2CH2O)e(CH(CH3)CH2O)fH
wherein a, b, c, d, e and f are integers from 1 to 350 reflecting the respective polyethylene oxide and polypropylene oxide blocks of said polymer. The polyoxyethylene component of the block polymer constitutes at least about 10% of the block polymer. The material preferably has a molecular weight of between about 1,000 and about 15,000, more preferably from about 1,500 to about 6,000. These materials are well-known in the art. They are available under the trademark xe2x80x9cPluronicxe2x80x9d and xe2x80x9cPluronic Rxe2x80x9d, a product of BASF Corporation.
Alkyl Glycosides
R21O(R22O)n(Z1)p
wherein R21 is a monovalent organic radical (e.g., a monovalent saturated aliphatic, unsaturated aliphatic or aromatic radical such as alkyl, hydroxyalkyl, alkenyl, hydroxyalkenyl, aryl, alkylaryl, hydroxyalkylaryl, arylalkyl, alkenylaryl, arylalkenyl, etc.) containing from about 6 to about 30 (preferably from about 8 to 18 and more preferably from about 9 to about 13) carbon atoms; R22 is a divalent hydrocarbon radical containing from 2 to about 4 carbon atoms such as ethylene, propylene or butylene (most preferably the unit (R22O)n represents repeating units of ethylene oxide, propylene oxide and/or random or block combinations thereof); n is a number having an average value of from 0 to about 12; Z1 represents a moiety derived from a reducing saccharide containing 5 or 6 carbon atoms (most preferably a glucose unit); and p is a number having an average value of from 0.5 to about 10 preferably from about 0.5 to about 5.
Examples of commercially available materials from Henkel Kommanditgesellschaft Aktien of Dusseldorf, Germany include APG 300, 325 and 350 with R21 being C9-C11, n is 0 and p is 1.3, 1.6 and 1.8-2.2 respectively; APG 500 and 550 with R21 is C12-C13, n is 0 and p is 1.3 and 1.8-2.2, respectively; and APG 600 with R21 being C12-C14, n is 0 and p is 1.3.
While esters of glucose are contemplated especially, it is envisaged that corresponding materials based on other reducing sugars, such as galactose and mannose are also suitable.
Amine oxides having formula:
R18R19R20Nxe2x95x90O
wherein R18, R19 and R20 are saturated aliphatic radicals or substituted saturated aliphatic radicals. Preferable amine oxides are those wherein R18 is an alkyl chain of about 10 to about 20 carbon atoms and R19 and R20 are methyl or ethyl groups or both R18 and R19 are alkyl chains of about 6 to about 14 carbon atoms and R20 is a methyl or ethyl group.
Amphoteric synthetic detergentsxe2x80x94can be broadly described as derivatives of aliphatic tertiary amines, in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contain from about 8 to about 18 carbons and one contains an anionic water-solubilizing group, i.e., carboxy, sulpho, sulphato, phosphato or phosphono. Examples of compounds falling within this definition are sodium 3-dodecylamino propionate and sodium 2-dodecylamino propane sulfonate.
Zwitterionic synthetic detergentsxe2x80x94can be broadly described as derivatives of aliphatic quaternary ammonium, phosphonium and sulphonium compounds in which the aliphatic radical may be straight chained or branched, and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic water-solubilizing group, e.g., carboxy, sulpho, sulphato, phosphato or phosphono. These compounds are frequently referred to as betaines. Besides alkyl betaines, alkyl amino. and alkyl amido betaines are encompassed within this invention.
Particularly preferred nonionic surfactants are polyoxyethylene and polyoxypropylene condensates of linear aliphatic alcohols.
The preferred range of surfactant is from about 0.5 to about 30% by wt., more preferably from about 0.5 to about 15% by weight of the composition.
Sequestrants
The detergent compositions herein may also optionally contain one or more transition metal chelating agents. These components may also have calcium and magnesium chelation capacity, but preferentially they show selectivity to binding heavy metal ions. Such chelating agents can be selected from the group consisting of amino carboxylates, amino phosphonates, polyfunctionally-substituted aromatic chelating agents and mixtures therein. Without intending to be bound by theory, it is believed that the benefit of these materials is due in part to their exceptional ability to remove iron and manganese ions from washing solutions by formation of soluble chelates.
Amino carboxylates useful as optional chelating agents include ethylenediaminetetraacetates, N-hydroxyethylethylenediaminetriacetates, nitrilotriacetates, ethylenediamine tetraproprionates, triethylenetetraamine-hexaacetates, diethylenetriaminepentaacetates, ethylenediamine disuccinate, and ethanoldiglycines, alkali metal, ammonium, and substituted ammonium salts therein and mixtures therein.
Amino phosphonates are also suitable for use as chelating agents in the compositions of the invention when at least low levels of total phosphorus are permitted in detergent compositions, and include ethylenediaminetetrakis (methylenephosphonates) and diethylenetriaminepentakis (methylenephosphonates). Preferably, these amino phosphonates do not contain alkyl or alkenyl groups with more than about 6 carbon atoms.
Polyfunctionally-substituted aromatic chelating agents are also useful in the compositions herein. See U.S. Pat. No. 3,812,044, issued May 21, 1974, to Connor et al. Preferred compounds of this type in acid form are dihydroxydisulfobenzenes such as 1,2-dihydroxy-3,5-disulfobenzene.
If utilized, these chelating agents will generally comprise from about 0.1% to about 10% by weight of the detergent compositions herein. More preferably, if utilized, the chelating agents will comprise from about 0.1% to about 5.0% by weight of such composition.
Anti-Scalants
Scale formation on dishes and machine parts can be a significant problem. It can arise from a number of sources but, primarily it results from precipitation of either alkaline earth metal carbonates, phosphates or silicates. Calcium carbonate and phosphates are the most significant problem. To reduce this problem, ingredients to minimize scale formation can be incorporated into the composition. These include polyacrylates of molecular weight from 1,000 to 400,000 examples of which are supplied by Rohm and Haas, BASF and Alco Corp. and polymers based on acrylic acid combined with other moieties. These include acrylic acid combined with maleic acid, such as Sokalan CP5 and CP7 supplied by BASF or Acusol 479N supplied by Rohm and Haas; with methacrylic acid such as Colloid 226/35 supplied by Rhone-Poulenc; with phosphonate such as Casi 773 supplied by Buckman Laboratories; with maleic acid and vinyl acetate such as polymers supplied by Hxc3xcls; with acrylamide; with sulfophenol methallyl ether such as Aquatreat AR 540 supplied by Alco; with 2-acrylamido-2-methylpropane sulfonic acid such as Acumer 3100 supplied by Rohm and Haas or such as K-775 supplied by Goodrich; with 2-acrylamido-2-methylpropane sulfonic acid and sodium styrene sulfonate such as K-798 supplied by Goodrich; with methyl methacrylate, sodium methallyl sulfonate and sulfophenol methallyl ether such as Alcoperse 240 supplied by Alco; polymaleates such as Belclene 200 supplied by FMC; polymethacrylates such as Tamol 850 from Rohm and Haas; polyaspartates; ethylenediamine disuccinate; organo polyphosphonic acids and their salts such as the sodium salts of aminotri(methylenephosphonic acid) and ethane 1-hydroxy-1,1-diphosphonic acid. The anti-scalant, if present, is included in the composition from about 0.05% to about 10% by weight, preferably from 0.1% t o about 5% by weight, most preferably from about 0.2% to about 5% by weight.
Corrosion Inhibitors
The composition my optionally contain corrosion inhibitors to reduce the tarnishing of silver flatware. Such inhibitors include benzotriazole and other members of the azole family. Particularly preferred are azoles, including imidazoles. Additional antitarnish additives include water-soluble bismuth compounds such as bismuth nitrate as taught in GB 2,297,096 A; heavy metal salts of copper, iron, manganese, zinc, or titanium (EP 0 636 688 A1, GB 2,283,494 A); paraffin oil; and non-paraffin oil organic agents such as fatty esters of mono or polyhydridic alcohols as claimed in EP 0 690 122 A2.
Antifoams
The compositions, when formulated for use in machine dishwashing compositions, preferably include an antifoam system. Suitable antifoam systems for use herein may include essentially any known antifoam compound, including, for example, silicone antifoams, silicone oil, mono- and distearyl acid phosphates, mineral oil, and 2-alkyl and alcanol antifoam compounds. Even if the machine dishwashing composition contains only defoaming surfactants, the antifoam assists to minimize foam which food soils can generate. The compositions may include 0.02 to 2% by weight of antifoam, preferably, 0.05 to 1.0%.
Form of the Composition
The machine dishwashing compositions disclosed herein can be formulated in any desirable form such as powders, granulates, pastes, liquids, gels, solids or tablets. As an example, the process of preparing a granulate may involve preparing a slurry of the ingredients identified above and drying the mixture by means of suitable equipment such as a turbine dryer (Turbogranulation dryer ex Vomm-Turbo Technology, Vomm Impianti E Processi SrL, Milan, Italy). Also, the process may involve preparing the slurry, spray-drying the slurry by conventional techniques using a spray tower in which the slurry is atomized and dried in a hot air stream, followed by restructuring the resulting powder, optionally after milling, in a granulation process (Lxc3x6dige recycler and Lodige plow shear). In a particularly preferred process, the slurry is sprayed onto fine (recycled) particles and then dried to form gradually growing co-granules. Another attractive possibility is to dry the slurry in a rotary drum granulator and to spray slurry onto recirculated fines, thus building up coarser particles. These particles are either simultaneously or subsequently dried to give a co-granule with a more homogeneous moisture distribution than those obtained by use of a turbine dryer.
The process of preparing a tablet may involve admixing the ingredients identified above, transferring the mixture to the tablet die, and compressing with a compaction pressure from about of 3xc3x97106 kg/m2 to about 3xc3x97107 kg/m2. It may be preferable to pre-granulate some or all of the ingredients, optionally with surfactant to enhance dissolution, to give granulates of size 100-2000 microns and mix these together with any remaining material prior to compaction. Another possibility is to pre-coat the granulate with any liquid component of the composition via, for example, a fluid bed, pan coater or rolling drum to give encapsulates. The encapsulates are then compressed with a compaction pressure from about 1xc3x97106 kg/m2 to about 3xc3x97107 kg/m2.
Machine Dishwashing Method
A preferred machine dishwashing method includes treating soiled articles selected from crockery, glassware, hollowware, silverware and cutlery and mixtures thereof, with an aqueous solution having dissolved or dispersed therein an effective amount of a machine dishwashing composition disclosed herein. By an effective amount of the machine dishwashing composition it is meant from 8 g to 60 g of the composition dissolved or dispersed in a wash solution of volume from 3 to 10 liters, as typical product dosages and wash solution volumes commonly employed in conventional machine dishwashing methods.

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


An inexpensive generally retrofitable drop-in cartridge-unit of light-weight pneumatic-cylinder design for replacing the conventional metal/compression-spring member housed within the frame of a gun, thereby providing significantly smoother, quiter, more rapid, and more reliable cyclic-action upon firing of the gun. The preferred embodiment cartridge-unit is internally configured whereby a near constant spring-load rise is provided as the bolt-action slides aftward, thereby effectively spreading resultant recoil-action inertial-kickback more evenly throughout the bolt-travel. Hence, substantially reducing disturbing kickback, enabling a more rapid succession of shots per given shot-grouping owing to the shooter""s improved recovery-time. Various iterations are set forth, including those of single, double, and tripple telescopic-action, and a hybrid/metal-pneumatic variant, as well as generic-variants providing manual and automatic pneumatic-pressure adjustment. Plus, a further iteration facilitating manual adjustment of air-gun thrust-pressure.

1. Field of the Invention
This invention relates to recoil reducing buffering (or attenuating) devices for firearm (employing an explosive charge) guns of various types, sizes, and degrees of automation; and more specifically, it relates to those types of counter-recoil apparatus employing a pneumatic-cylinder as its primary kinetic-energy absorption mechanism for both reducing mechanical-shock to the gun-structure, and to improve aiming-accuracy by reduction of xe2x80x9caim throw-offxe2x80x9d imposed by each firing kick-back; xe2x80x94also, the disclosure sets forth features to provide improved projectile powering means applicable to air-guns.
2. Relevant Prior-Art
Background research discovery provides some prior patent-art regarded as germane to this disclosure, chronologically for example U.S. Pat. No. 836,502 (Filed: April 1906) shows a portion of an early automated firearm breech employing a built-in air-chamber fitted with an annular plunger-piston acting against a recoil-spring while engaged forwardly by a rearwardly recoiling-rod member of the breech mechanism.
In U.S. Pat. No. 900,865 (Filed: March 1907) is shown an automatic magazine-fed handgun having a built-in air-chamber fitted with a plunger-piston, whereby the tubular air-chamber reacts aftward around the plunger-piston.
In U.S. Pat. No. 1,297,240 (Filed: December 1916) is shown an automatic machine-gun having a built-in air-chamber fitted with a plunger-piston, whereby rearward action of the breech-bolt is rebuffed via both a recoil-spring and the momentary compression of captive air which reactively induced compression is regulatable via an adjustable screw-adjusted relief-valve device.
In U.S. Pat. No. 1,398,452 (Filed: September 1919) is shown an automatic-rifle having an aftwardly built-in air-chamber and breech-piston arrangement obviating need of a recoil-spring.
In U.S. Pat. No. 1,351,141 (Filed: April 1920) is shown a hydraulic (oil filled) recoil-buffer spool device for automated firearms, wherein a restricting orifice is staged between two longitudinally opposite chambers; and whereby a discharge of breech pressurized oil is forced past a preferably tapered longitudinal needle-valve arranged coaxially within said orifice. The arrangement in combination with a substantially conventional recoil-spring thus serving to modulate the otherwise jolt of sliding-bolt action upon firing of the gun.
In U.S. Pat. No. 3,3298,282 (Filed: February 1965 from Germany) is shown a built-in pneumatic recoil modulator device in combination with a conventional recoil-spring for automatic type firearms, wherein a fixed full-area piston is driven within an aftwardly traveling tubular breech extension chamber; the piston thus acting in concert with the helical-spring to more smoothly arrest aftward travel of the breech-bolt.
In U.S. Pat. No. 3,636,813 (Filed: June 1969 from Germany) is shown an elaborate dual-cylinder hydraulic counter-recoil device employing full-area pistons acting within a pair of tubular barrels; which apparatus is intended for modulating the inertia-forces of recoil encountered in relatively heavy artillery weaponry thus unsuitable for hand-portable guns.
In U.S. Pat. No. 3,599,530 (Filed: November 1969) is shown an elaborate said automatic-replenisher for the hydro-pneumatic recoil systems of relatively large caliber weaponry; unsuitable for hand-portable guns.
In U.S. Pat. No. 3,901,125 (Filed: March 1973) is exemplified an automatic-pistol of the popular Colt/45-caliber sidearm type, wherein is provided a combination conventional recoil-spring and a fixed delayed-action pneumatic-chamber driven over-upon by an aftward moving cupped front breech-plug (92), whereupon piston 102 (having an O-ring seal) ensues to build-up a compressive resistance to the recoiling breech inertia. The inventor teaches that the greater breach-loading sustained by the higher recoil-resistance, enables the sent projectile to travel further down the barrel before the bolt opens, allegedly improving aiming accuracy and repeated firing comfort owing to reduced xe2x80x9ckickxe2x80x9d. The pneumatic members are at ambient-pressure (not pre-pressurized) prior to firing, and a resilient rubber-cushion (132) is required to absorb final travel; xe2x80x94some contemplation is given to a retrofitable pneumatic device adaptable to such an older gun (col.-3/lines. 4-15).
In U.S. Pat. No 4,307,653 (Filed: September 1979) and U.S. Pat. No. 4,445,644 (Filed: May 1981) are shown generic variants of a recoil buffer with interacting first and second gas-chambers (note: xe2x80x94neither of which is pre-pressurized, and some iterations include an oil medium), wherein upon recoil after firing, a compressive force is applied to the first chamber, whereby a gas/pressure-differential is generated between first and second longitudinal chambers, thus producing a gas flow into the second chamber via a venting fluid-diode restrictor device; hence, the apparatus is a type of shock-absorber only, still requiring a conventional metal recoil-spring for cyclic-action.
In U.S. Pat. No. 4,388,855 (Filed: October 1980) is shown a built-in pneumatic decelerator device for a firearm, wherein a breech air-chamber (8, not pre-pressurized) also contains a metal recoil-spring (60) and is moved aftwardly upon firing of the gun, causing fixed hollow piston member (12) to effectively slide into the air-chamber, thus compressing both the spring and the air captive therein.
In U.S. Pat. No. 4,492,050 (Filed: April 1983 from U.K.) is shown an air-powered gun having a gas-tight pressure-chamber for launching a projectile, which chamber is pressurized via a manually-actuated cocking-pump, and has no relevance to combating recoil action.
In U.S. Pat. Nos. 4,850,329 and 5,193,517 (Filed: January 1988 and June 1991) from U.K. by the Theoben-group; Is shown a firing-mechanism for air-powered guns, wherein a longitudinal cylinder (4) with an internally sliding primary-piston (5) having an extended-skirt portion also contains a free-sliding bobbin-piston (1) acting as an inertial-mass within the extended-skirt; said bobbin-piston having an axial air-port and an optional coil-spring urging bobbin-piston toward the gun""s discharge-port, the effect of which is to reduce accuracy disturbing kinetic-energy at the end of the primary-piston""s projectile launching travel.
In U.S. Pat. No. 5,076,139 (Filed: August 1990) is shown an exemplified conventional semi-automatic Beretta(mfg.) side-arm gun said to have a problematical hammering condition of the slide against the frame at maximum slide-travel, which creates destructing structural cracks in the frame. A resilient shim-like buffer device is thus retrofitable, which is said to significantly relieve the peak-loads imposed upon the frame; however, the simple device only treats the symptom, and does not eliminate the inherent mechanical defect inherent in this metal recoil-spring design.
In U.S. Pat. No. 5,265,852 (Filed: October 1991) is shown a gas-spring of the type employed widely in the tooling-Industry to reduce shock-forces encountered during mating of metal-dies; and noteworthy here is the use of a rod-like piston member, which owing to it""s reduced piston-area relative to the cylinder-bore cross-section, is able to travel within the cylinder without creating excessive increase in Internal working-pressure (as compared to a full-area piston operating within a closed cylinder).
In U.S. Pat. No. 5,339,789 (Filed: July 1992 from Germany) is shown a low-recoil air-rifle, whereto the gun-mechanism referenced by the gun-barrel/breech (20) is mounted atop a wooden-stock portion (26), whereto a special mounting is provided between the gun-barrel and the gun-stock, which employs a roller and inclined-ramp mechanism serving to alter the vector of recoil-forces sufficiently as to greatly reduce loss of target in the sights upon firing of the air-rifle. However, such an extensive alteration to conventional existing guns is not a prectical consideration.
In U.S. Pat. No. 5,513,730 (Filed: September 1995) is shown a so-called non-linear longitudinal recoil/shock-absorber apparatus for mounting abaxially to a gun-barrel for example, so as to react in a manner said to reduce recoil kick upon firing of the gun. A specially configured helical-spring is located inside the cylinderical body of the shock-absorber, which becomes axially torqued as to cause the spring to diametrically expand and impinge frictionally against the internal-wall of the cylinder chamber containing oil. However, it is believed that after extended use, the level of shock-absorption deteriorates owing to internal wear.
In U.S. Pat. No. 5,727,286 (Filed: March 1996 from Taiwan) is shown a pneumatic door-closer of the elongate cylinder type, having an adjustable/needle-valve at the otherwise occluded end of the cylinder, and a piston-shaft extending oppositely from the cylinder. However, the internal piston-head is of the full-area type, and the primary feature of the invention is a two-stage linear-action loading, whereby internal-steps upon both the cylinder-wall and the piston-shaft facilitates a convenient xe2x80x9chold-extendedxe2x80x9d function, until the user applies an overcoming retraction force, whereby the piston-shaft is biased back inward of the cylinder.
In U.S. Pat. No. 5,797,593 (Filed: December 1996from Japan) is shown an oil-dampened cylindrical so-called gas-spring apparatus common to modern automotive use as a hatch-strut, which is referenced here primarily owing to its pre-pressurized factory-sealed swedged-over non-rechargable O-ring construction.
In U.S. Pat. No. 6,059,273 (Filed: February 1995 from Sweden) is shown a cylinderical gas-spring having a full-area piston-head designed to provide relatively light initial longitudinal axial/thrust-resistance of the outwardly extending piston-shaft (4), and includes a cooperating donut-piston sliding internally on the piston-shaft, whereby greater resistance is provided once the piston-shaft has receeded slightly into the cylinder; this variable resistance action being facilitated via the internal gas-pressure/differential being impossed upon the full piston face versus the piston""s partial opposite-side surface-area.
Therefore, in full consideration of the preceding patent review, there is determined a need for an improved form of device to which these patents have been largely addressed. The instant inventor hereof believes their newly improved firearm recoil pneumatic modulator device, commercially referred to as the RECOILX-Cartridge(trademark), currently being developed for production under auspices of the Bergstrom-Mfg./Mkt.Co., exhibits certain advantages as shall be revealed in the subsequent portion of this instant disclosure.
A.) In view of the foregoing discussion about the earlier invention art, it is therefore important to make it pellucid to others interested in the art that the object of this instant invention disclosure is to provide a cylindrical preferably xe2x80x9cdrop-inxe2x80x9d pneumatic unit in place of a conventional helically-coiled steel recoil-spring heretofore typically existing within the breech-mechanism or stock-region of a conventional gun (rifled-bore firearm) or a conventional shotgun (smooth-bore firearm) of both semi-automatic and fully-automatic types thereof (as well as those heavier sorts of firearm weaponry such as semi-automatic shotguns, submachine-guns, plus military granade-launchers and cannons); xe2x80x94which serves to improve the firearm""s so called recoil-action characteristic by generally making the rate of breech opening and closing more constant as compared to that rate characteristic of metal helically-wound metal (generally carbon-steel) recoil-springs.
By replacing (OEM-substituting or aftermarket retrofitting) a conventional recoil-spring with my novel gas-spring apparatus, the former progressive-rate metal/compression-spring (becoming very increasingly resistive as the breech-mechanism travels aftward) action becomes transformed into a nearly constant-rate of recoil-action provided by my special pneumatic/compression-spring. My basic gas-spring unit also greatly abrogates the usual spring-noise resonance (virtually eliminating familiar xe2x80x9ccah""chingxe2x80x9d like vibration), while obviating off-axis (longitudinal-axis) forces, whereby reduced cycling-time (improving firing-rate), and a substantially reduced xe2x80x9ckickxe2x80x9d is realized; xe2x80x94which improved recovery-time (time required to realign a gun""s sights upon target) correlates to a consistently tighter grouping of shots at any demonstrated target distance, and significantly quieter, smoother, and more precision feeling firing-action; xe2x80x94which is thus also substantially less stressful to both gun and gunner. Accordingly, it is further asserted that these types of guns can also now be keenly redesigned as to take advantage of the significantly lower gun-frame stesses imposed by our particular gas-spring cartridge configuration, when offered as a standard OEM(original equipment manufacturer) provision.
B.) Another object of this invention disclosure is to set forth a gas-spring apparatus preferably in the form of a removable cartridge unit according to preceding item-A; wherein the cross-sectional area of the piston within the fluid-cylinder body of the cartridge is preferably substantially smaller than the cross-sectional area of the fluid-cylinder, whereby I thus refer to the piston generally as a piston-rod, owing that it preferably is less than half the cross-sectional area of the fluid-cylinder itself. Therefore, as the piston-rod makes its stroke through the fluid-cylinder, the relative differential-ratio of piston-rod cross-section diameter to cylinder cross-sectional diameter thus enables a so-called near constant compressive resistance of the piston-rod as it is plunged into the cylinderical gas-chamber of the cylinder-body. Moreover, owing to this preferred relatively diminutive effective piston-diameter, there are preferably no fluid gas-tight seals moving with the piston-rod; the fluid-seals rather being preferably fixed within the entry-bore through which the piston-rod travels. The cylinder-body is preferably of conventional circular cross-section configuration, although a non-circular shape could optionally sulfice if such were desired.
Hence, it is necessarily understood that as the manufacturing design-engineer changes the critical diameter of the piston-rod relative to the diameter of the cylinder-body, a given factory-filled static-pressure setting withstanding, xe2x80x94the characteristic increase in dynamic-pressure (a product of relative gas-chamber diameter X recoil-stroke length or travel) can now be virtually tailored to the design-engineer""s preference, from a nearly flat or xe2x80x9cnear constantxe2x80x9d compression energy profile when plotted as a graphic-chart, to a relatively steeply sloped profile compression-pressure rise more approximating that of a conventional metal/recoil-spring (albeit absent of adverse spurious mechanical aberrations characteristic of compression-springs), xe2x80x94simply by designing the piston-rod to a diameter approximating that of the cylinder within which it is operating.
In most gun applications, the ideal passive (not introducing spurious mechanical aberrations) rebuffing action enabled by invention of this disclosure, is to realize the afore stated near constant fluidic compression pressure-rise within the gas-chamber, as the piston-rod is being driven into the gas-chamber by the gun""s conventional breach action. Understandably, the diameter of the piston-rod must necessarily be designed in keeping with the degree of counter-pressure required to sustain the imposed force of the recoil-action; xe2x80x94plus, in some cases, owing to excessively confined operating-space, I am also setting forth generic-variant cartridge iterations employing compound telescopic configurations (such as a piston-rod within a piston-rod, acting either in the same direction or in opposite directions).
Generally speaking however, my cartridges are employed in a manner whereby the cylinder body portion is fixed, the usually lighter-weight piston-rod member thus acting therein against fluid-pressure, xe2x80x94moves during recoil action; xe2x80x94however if preferred, the converse arrangement can be adapted, whereby the piston-rod remains fixed and instead the cylinder-body moves yieldingly to the gun""s breech-mechanism. Alternately, it is also possible in some guns, that both the cylinder-body and the piston-rod move relative to one another; xe2x80x94either of these three implementations nevertheless achieving the object of eliminating the conventional metal/recoil-spring as shall be illustrated later herein.
Another design option is to employ seals having different coefficient-of-friction drag-loading (lighter or heavier slip-resistance) acting upon the piston-rod; a light loading generally being more suitable for guns having a positive breech locking mechanism, while a heavier type of seal-drag characteristic of generally greater contact-area is considered to be particularly appropriate for guns inherently relying upon the initial breakaway-resistance of the breech block mechanism to build-up breech-chamber pressure.
C.) Another object of this invention disclosure is to set forth the gas-spring apparatus for firearms in the form of a preferably removable drop-in cartridge unit according to preceding items-AandB, wherein the first/end-wall (or head end) portion forming the forward end of the longitudinal cylindrical body""s imperforate gas-chamber no preferably also forms a longitudinally arranged secondary/cylindrical-chamber within which is contained a free-floating inertial-mass device. This novel inertial-mass serves to effectively prolong the forward impulse during closure-sequence of a conventional breech-mechanism in a semi or-automatic or full-automatic firearm, the inertial-mass normally being held aftward within the secondary/cylindrical-chamber by a shuttle/compression-spring. In some such firearms, as the aftwardly driven bolt commences to engage and scoop the next round of ammunition slidably forward into the breech chamber, whereby the bolt necessarily becomes secured forwardly in some way (such as via a rotational cam-locking action), an irregularly-sized round or mere dirt can cause difficulty with this cyclic procedure, resulting in a so-called xe2x80x9cbounce-backxe2x80x9d event and a jam like misfire of that round (which must usually be manually cleared). Hence, I have found that the presence of an assisting secondary/inertial-mass can provide sufficient additional urging (in addition to that being provided by our gas-spring portion alone) of breech-bolt closure as to virtually overcome the impediment and efficiently drive the breech-bolt mechanism into its fully forward and securely locked position. The secondary/inertial-mass is basically a type of active-weight such as a heavy metal slug or collar, or even particulates (such as loose lead-shot), in any case necessarily normally held rearwardly in some way; xe2x80x94accordingly, as the primary-mass comes to a halt, the secondary/inertial-mass continues to thus move forward sufficiently as to effectively prolong the closing force of the breech-bolt.
D.) Another object of this invention disclosure is to set forth the gas-spring article for firearms in the form of a preferably removable drop-in cartridge unit according to preceding items-AandB, wherein I have found that some firearm implementations benefit from a novel two-in-one combination of our gas-spring operating as an assembly in longitudinal cooperation with a xe2x80x9cboosterxe2x80x9d metal/compression-spring member arranged coaxially to the gas-spring casing for those firearm applications where an increased breech closing speed is needed. Another iteration of this objective is to alternately include a xe2x80x9cmagnetic-springxe2x80x9d comprising a pair of rare-earth (preferably of neodymium type) permanent-magnets, PM-1 being arranged fixed with the gas-spring cartridge cylinder go aftward end-wall, the requisite opposing PM-2 being affixed to the inboard-terminus of the piston-rod. Thus, with their interfacing magnetic-poles arranged necessarily either plus-to-plus (+:+) or equivalently minus-to-minus (xe2x88x92:xe2x88x92), a powerful resistive energy is resultantly encountered as the piston-rod approaches its momentary aftwardly driven position.
Another related iteration of this magnetic complement to the basic gas-spring cartridge unit is in the form of a resistive-breakaway configuration, whereby the PM-1xe2x80x2 member is affixed to the inboard-terminus of the piston-rod so as to attractively interact with a PM-2xe2x80x2 an annular (encircling the concentric piston-rod) magnet affixed proximal the forward end-wall of the cartridge body. In this alternate magnetic embodiment, the function of the interacting Permanent-magnets (PM-1xe2x80x2 and PM-2xe2x80x2) is to generate a high initial-breakaway resistance, which would be particularly useful in possibly entirely obviating need for a mechanical breakaway-cam type of breech-mechanism. Thus, with their interfacing magnetic-poles arranged necessarily either plus-to-minus (+:xe2x88x92) or equivalently minus-to-plus (xe2x88x92:+), a powerful attractive magnetic-energy field is resultantly encountered as the piston-rod""s inward-terminus portion approaches its normal forwardly resting position.
E.) Another object of this invention disclosure is to set forth the gas-spring article for firearms in the form of a preferably removable drop-in cartridge unit substantially according to preceding items-AandB, yet wherein the cylindrical-wall bore portion however can be configured at the factory with variable diameters along the piston-rod""s linear path, enabling the designer still further options in the form of operating characteristics.
Accordingly, four such generic-variations are being set forth, essentially as follows: xe2x80x94all employing a piston-rod having a piston-head with an annular-seal which impinges against a reduced diameter (necked-down) portion of the cylindrical-chamber. However, in this embodiment the piston-head becomes effective only in selective portions of the gas-chamber; for example the cylindrical-wall diameter is in the generic variations of this embodiment narrowed either forwardly, aftwardly, forwardly and afterwardly, or only centrally (approximately medially), xe2x80x94thereby modifying both the pneumatic and frictional resistance and rate characteristics at which the piston-rod translates through the cylindrical-chamber.
A further generic-variant embodiment of this iteration can be realized by optionally eliminating the annular-seal from the piston-head, and establishing a critically sized by leakage-gap relative to any necked-down cylindrical-wall surfacing; thereby enabling the designer to variably regulate rate of piston-rod movement throughout the travel of the piston-rod upon firing of the gun.
F.) Another object of this invention disclosure is to set forth the gas-spring article for firearms in the form of a preferably removable drop-in cartridge unit according to preceding items-AandB, wherein the longitudinal cylindrical body of our gas-spring cartridge includes a slider-piston having an annular-seal impinging radially upon the inside-diameter of the cylindrical body while supported against the constant thrust of gas-chamber pressure via an externally adjustable preferably male/screw-threaded member acting in cooperation upon mating female/screw-threads provided upon the tubular piston-rod. Hence, the slider-piston serves to conveniently enable a degree of user adjustment of the gas-chamber positive-pressure by resultantly displacing the slider-piston forward (increasing chamber pressure) or aftward (reducing chamber pressure) relative to the gas-chamber as may be desired by the user; for example, in order to thereby tunably compensate for different types of ammunition, which explosive force directly effects the recoil reaction of the gun.
G. ) Another object of this invention relates specifically to air-powered guns instead of explosive-powered guns, wherein is provided a novel manually-selective pressure-modulator device, enabling convenient adjusting of the potential propulsive force contained within the gas-spring propulsion-chamber, which instead of an explosive-charge, serves to thrust a projectile from a conventional compressed-gas (generally air) powered gun. The overall gas-spring principle operating in similar fashion to our afore covered uniquely adjustable gas/recoil-spring for firearms, described in preceding item-C.
The pressure-modulator preferably basically comprises a longitudinally slidable attenuator-piston arranged aftwardly within the imperforate cylinderical-chamber of the air-gun""s manually actuated gas/propulsion-spring chamber (having a longitudinal-axis) and a trigger released manually recockable longitudinally reciprocating-piston having a forward thruster-head acting to launch a projectile placed within the staging-chamber of the gun""s longitudinal barrel-bore. The attenuator-piston is provided with a coaxial screw-threaded adjustor-shank extending longitudinally aftward from the air-guns""s cylindrical-chamber; whereby manual rotation of the adjustor-shank (clockwise or counter-clockwise) moves the attenuator-piston forward or aftward, as to thereby effectively vary the compression-ratio of the air contained captively within the cylindrical-chamber as desired by the gunner.
H.) GENERAL SUMMARY OF ADVANTAGES: xe2x80x94our Gas-spring serves to provide the following benefits . . . a.) to substantially reduce recoil; b.) to significantly improve time to aim; c.) to minimize vibration gain smoothness; d.) to eliminate spring noise; e.) to eliminate lateral forces; f.) to improve cycling time and durability; g.) to facilitate breech-bolt action characteristics otherwise unattainable; h.) to provide aftermarket drop-in retrofitting; i.) to enable gun-structure redesign for lighter-weight; j.) to provide quick and easy field-adjustment attuning of both firearms (breech-bolt resistance for different ammunition) and air-guns (pellet, dye-ball propulsive-thrust).

Firearm pneumatic counter-recoil modulator and airgun thrust-adjustor


A means for a physically challenged user to gain access to their anus in order to clean the area through a wiping action. The device has a handle that operates through a positionable mid-section to a pair of spreader elements used to spread the cheeks of the buttocks while a wiping element covered by a sleeve is brought forward through leverage, wherethen while holding the handle wiping can be performed through repetitive parallel movement of the device.

1. Field of the Invention
The present invention relates generally to personal hygiene and, more specifically, to a device with an operable handle and positional midsection having spreading elements for spreading the cheeks of one's buttocks to gain access to ones anus wherethen a wiping element having a disposable sleeve is moved forward between said spreading elements in order to be rubbed in a wiping action across said anus to clean the area after defecation. Comprising the device in a positional mid section containing a flexible displacement element attached to a handle that is depressed to transfer downward force through said displacement element on to a pivot point having a plurality of linkages wherethen if force is applied, said force causes the spreader elements to transverse outward in a spreading action meanwhile simultaneously having a set of hinged elements and linkage utilized through the same downward displacement and lever action to bring the wiping element forward to perform a cooperating wiping and spreading function. Additionally the present invention allows for the easy change and replacement of sleeves that fit over the wiping element by use of slipping a sleeve onto the element for use and removing said sleeve after use by utilizing a tab that may be manipulated downward to slide said sleeve off the element for contact free disposal.
The device can also be used to push out dry fecal matter by appropriately positioning the spreading elements around the anus or by placing lubricant on one spreading element and inserting into the anus to moisten dried material for evacuation.
2. Description of the Prior Art
There are other wiping devices designed for wiping ones anus. Typical of these is U.S. Pat. No. 1,818,388 issued to Farley on Aug. 11, 1931
Another patent was issued to Leonard et al. on Jan. 11, 1966 as U.S. Pat. No. 3,228,398. Yet another U.S. Pat. No. 4,075,033 was issued to Knox et al. on Feb. 21, 1978 and still yet another was issued on Sep. 3, 1991 to Tetrault as U.S. Pat. No. 5,044,040.
Another patent was issued to Steffen et al on Oct. 22, 1996 as U.S. Pat. No. 5,566,418. Yet another U.S. Pat. No. 6,058,524 was issued to Deveer on May 9, 2000. Another was issued to Saatjian et al. on Aug. 7, 2001 as U.S. Pat. No. 6,269,515 and still yet another was issued on Feb. 10, 2004 to Hillman as U.S. Pat. No. 6,689,224.
Another patent was issued to Paille on Jul. 31, 2007 as U.S. Pat. No. 7,249,392. Yet another British Patent No. GB2237981 was issued to Feldmann on Nov. 13, 1989. Another was issued to Wenger on Jul. 6, 2000 as PCT Patent No. WO00/38563 and still yet another was issued on Sep. 20, 2006 to Buckingham as British Patent No. GB2424173.