A polyester is provided which facilitates the separation of blood into light and heavy phases via centrifugation in a blood collection vessel. The polyester is useful as a component of a partitioning composition formulated to have appropriate specific gravity to be positioned intermediate the light and heavy blood phases during centrifugation. The polyester composition can be prepared with relative ease compared to prior art polyesters useful in blood partitioning compositions. The polyesters of this invention comprise a dicarboxylic acid member, a polymeric fatty acid, a diol member and a moiety having at least one polymerizable carbon-carbon double bond and at least one functional group capable of reacting with the ends of the polyester chain. The polyesters have a lower viscosity when synthesized and are later cured to increase their viscosity to the desired level.

1. Field of the Invention
The present invention relates to polyesters useful for facilitating the separation of blood serum or plasma from the cellular portion of blood.
2. Description of the Related Art
The compositions of the present invention are conveniently formulated into a partitioning composition for use in a blood collection vessel in which the blood sample is subjected to centrifugation until the cellular portion and serum or plasma are completely separated.
Note that while blood is the most usual candidate for physiological separation, conceivably urine, milk, sputum, stool solutions, meconium, pus and the like could all be subject to physiological separation and assay for therapeutic agents and the subsequent discussion, while focusing on blood for clarity, is not meant to be limited to blood.
The physical and chemical properties of the partitioning composition are such that a continuous, integral seal is provided between the separated blood phases, thereby maintaining separation of the phases after centrifugation and simplifying removal of the serum or plasma from the blood collection vessel. The high volume testing of blood components in hospitals and clinics has led to the development of various devices to simplify the collection of blood samples and preparation of the samples for analysis. Typically, whole blood is collected in an evacuated, elongated glass tube that is permanently closed at one end and sealed at the other end by a rubber stopper having a diaphragm which is penetrated by the double-tipped cannula used to draw the patient""s blood. After the desired quantity of blood is collected, the collection vessel is subjected to centrifugation to yield two distinct phases comprising the cellular portion of the blood (heavy phase) and the blood serum or plasma (light phase). The light phase is typically removed from the collection vessel, e.g., via pipette or decantation, for testing.
It has been proposed heretofore to provide manufactured, seal-forming members, e.g., resilient pistons, spools, discs and the like, in blood collection vessels to serve as mechanical barriers between the two separated phases. Because of the high cost of manufacturing such devices to the close tolerances required to provide a functional seal, they have been supplanted by fluid sealant compositions. Fluid sealant compositions are formulated to have a specific gravity intermediate that of the two blood phases sought to be separated, so as to provide a partition at the interface between the cellular and serum phases. Such compositions typically include a polymer base material, one or more additives for adjusting the specific gravity and viscosity of the resultant composition, and optionally, a network former. Representative fluid sealant compositions developed in the past include: styrene beads coated with an anti-coagulant; silicone fluid having silica dispersed therein; a homogeneous, hydrophobic polyester including a suitable filler, e.g., silica; a liquid alpha-olefin-dialkylmaleate, together with an aliphatic amine derivative of smectite clay or powdered silica; the reaction product of a silicone fluid with a silica filler and a network former; and a mixture of compatible viscous liquids, e.g., epoxidized vegetable oil and chlorinated polybutene, and a thixotropy-imparting agent, e.g., powdered silica, and liquid polyesters, a thixotropic gel comprising a dual resin component including poly-alpha-pinene of lower density combined with chlorinated octadecene of higher density, said gel further comprising a radiation stabilizer, a network stabilizer, a thixotropic agent and a pigment, and a gelatinous material admixed with fine resin particles having an average particle size of 0.01 to 2 microns and having an internal crosslinking density of 0.1 to 3 mmol/g.
Ideally, a commercially useful blood partitioning composition should maintain uniform physical and chemical properties for extended time periods prior to use, as well as during transportation and processing of blood samples, readily form a stable partition under normal centrifugation conditions and be relatively inert or unreactive toward the substance(s) in the blood whose presence or concentration is to be determined.
Inertness to substances sought to be determined is a particular concern when blood collection vessels are used for therapeutic drug monitoring (TDM), which is assuming an increasingly important role in drug treatment strategies. TDM enables the administration of drugs in the appropriate therapeutic ranges, established through the accumulated experience of clinicians, and consequently reduces the number of patients receiving dosage levels that are either below detection limits or toxic. Administration of drugs under TDM allows one to take into account such factors as drug tolerance developed with passage of time, presence of multiple physical disorders and synergistic or antagonistic interactions with other therapeutic agents. Among the drugs recommended for administration under TDM are those having dangerous toxicity with poorly defined clinical endpoint, steep dose-response curve, narrow therapeutic range, considerable inter-individual pharmacokinetic variability or non-linear pharmacokinetics, as well as those used in long term therapy or in the treatment of life-threatening diseases. By way of example, the evaluation of blood levels of a number of tricyclic antidepressant compounds, such as imipramine or desipramine, in relation to an empirically established therapeutic range is reported to be particularly useful in the treatment of seemingly drug-refractive depression. TDM is likewise used to monitor the dosage of anticonvulsant drugs, such as phenytoin and phenobarbital which are administered in the treatment of epilepsy, anti-tumor drugs, such as methotrexate, and other more commonly prescribed drugs, including, but not limited to digoxin, lidocaine, pentobarbital and theophylline.
Reports of studies on the effect of blood partitioning compositions on drug concentrations in serum and plasma indicate that care must be taken in the selection of polymeric materials which come into contact with the blood samples obtained for drug assay. See, for example, P. Orsulak et al., Therapeutic Drug Monitoring, 6:444-48 (1984) and Y. Bergquist et al. Clin. Chem., 30:465-66 (1984). The results of these studies show that the blood partitioning compositions provided in blood collection vessels may account for reduced serum or plasma values, as a result of drug absorption by one or more components of the composition. The reported decreases in measured drug concentrations appears to be time dependent. One report concludes that the observed decreases in drug concentrations may effectively be reduced by minimizing the interval between collection and processing. Another report recommends that blood samples be transported to the laboratory as soon as possible, with processing occurring within 4 hours. A commercially useful blood collection vessel, however, must produce accurate test results, taking into account routine clinical practices in large institutions, where collection, transportation and processing of blood samples may realistically take anywhere from about 1-72 hours.
Conventional polyester fluids are inadequate penetration barriers and therapeutic agents will diffuse into them and be partially absorbed with time, which interferes with quantitative assay for their presence. Attempts to solve this problem have centered around techniques for making the polyester itself more hydrophobic. Most therapeutic agents have high solubility parameters and associated high hydrophilicity (associated with high polarity functional groups like amines) because they must be soluble in aqueous liquids like blood, and water has a high solubility parameter. So, the direction has been to less hydrophilic, more hydrophobic, polymers to avoid the possibility of the therapeutic agents partially dissolving in a medium solubility parameter, medium polarity, polyester, and thus be more fully available in the serum phase for analysis. Imparting hydrophobic character to the polyester has been done via two main techniques. Firstly, a random polymer has been made of a diol and large quantities of a dicarboxylic acid with pendent, long (C9 to C13) olefin groups. Secondly, a random polymer has been made of a diol and large quantities of a dicarboxylic with a long olefin along its backbone, such as a C36 dimerized fatty acid. Such polyester compositions have proved useful as functional blood partitioning compositions having reduced affinity for therapeutic agents present in blood such as phenobarbital and imipramine. See, for example, W. L. O""Brien, U.S. Pat. No. 5,124,434, the entire disclosure of which is incorporated by reference in the present specification, as if set forth herein in full.
However many of these polyesters are highly viscous and difficult to transfer to the sample collection vials. It is therefore desirable to have a material that will facilitate physiological separations but does not have the difficulties associated with transferring highly viscous liquids.
We have now quite unexpectedly discovered novel high molecular weight polyester compositions which are useful in blood separation tubes and which are derived from a short-chain dibasic acid, a polymeric fatty acid, a branched-chain saturated aliphatic diol or a mixture of diols having a branched-chain diol as the principal component and a moiety having at least one polymerizable carboncarbon double bond and at least one functional group capable of reacting with the ends of the polyester chain. These polyester compositions are advantageously employed in small amounts in blood separation tubes and form a tight seal between the light and heavy phases of the blood. The polyester compositions are not affected by contact with the blood and they do not alter the blood components. The polyesters of the invention can be synthesized having one viscosity and then later be further polymerized or cured to increase their viscosity to a desired level. The density of the polymers is such that during the blood separation ultracentrifugation procedure they locate at the interface between the serum or plasma phase and heavier cellular phase. When centrifugation is terminated the polymers form a continuous integral barrier within the assembly to prevent the phases from recombining or mixing especially when decanting or pipetting the light phase. A small but effective amount, generally 2 to 5 grams, of the polyester sufficient to form the barrier between the phases is inserted directly into the separation tube either before or after the blood sample is collected. The polyester is in the form of a liquid having a density at room temperature in the range of about 1.01 to about 1.09.
More particularly, the polyesters of the invention comprise as repeating units:
A=(xe2x80x94C:Oxe2x80x94RAxe2x80x94O:Cxe2x80x94) wherein A is the residue of a polymeric fatty acid, particularly preferred is the residue of C36 dimer acid and wherein RA is an aliphatic or aromatic moiety having from about 20 to about 50 carbon atoms, preferably from about 22 to about 42 carbon atoms;
B=(xe2x80x94C:Oxe2x80x94RBxe2x80x94O:Cxe2x80x94) wherein RB is a member selected from the group consisting of a divalent aliphatic chain of 1-46 carbon atoms, preferably of from 1-34 and more preferably of from 3 to 34 carbon atoms; a divalent cycloaliphatic chain of 3-34 carbon atoms; a divalent arylene chain of from 6-34 carbon atoms, preferably of from 9-34; a divalent alkarylene chain of from 7-34 carbon atoms, a divalent alkarylalkylene chain of from 8-34 carbon atoms and mixtures thereof;
C=(xe2x80x94Oxe2x80x94RCxe2x80x94Oxe2x80x94) wherein RC is a member selected from the group consisting of compounds of the formula: RC=(CHnRm)k wherein n=0, 1,2, or 3; Rxe2x95x90H, C1 to C10 alkyl, CH2OCH2CH2, CH2CH2OCH2CH2O CH2CH2; m=0, 1, or 2; n+m=2; k=1 to 10; examples of the (xe2x80x94Oxe2x80x94Rcxe2x80x94Oxe2x80x94) member include, but are not limited to, 1,2 propylene glycol, 1,3 and 1,4 butanediol, 3-methyl 1,5 penanediol, diethylene glycol, triethylene glycol and the like; and
D=the residue of a compound having at least one polymerizable carbon-carbon double bond and at least one functional group capable of reacting with the ends of the polyester chain.
The polyesters are broadly characterized as being inert, hydrophobic, homogeneous compositions having molecular weights of from about 1,000 to 5,000 before curing, and can achieve molecular weights of from about 5000 to 500,000 after curing, densities in the range of from about 1.015 to about 1.060 g/cm3 and 100 deg. C. viscosities (kinematic) in the range of from about 100 to about 1000 centistokes before curing, which after curing can be increased to about 500 to greater than 10,000 centistrokes. Preferably, these polyesters will have 100 degree C. viscosities (kinematic) in the range of from about 100 to about 1000 centistokes before curing, which can be increased by curing to about 3,000 to about 6,000 centistrokes, and a density between of about 1.020 to about 1.050 g/cm3. The molar ratio of the sum of RA and RB to RC is in the range from about 1:1.5 to about 1:0.67.
The polyesters of this invention comprise a polymeric fatty acid (the repeating unit A), a dicarboxylic acid member (the repeating unit B), a diol member (the repeating unit C) and a moiety (the D component) having at least one polymerizable carbon-carbon double bond and at least one functional group capable of reacting with the ends of the polyester chain. Especially useful polyesters are derived from polymeric fatty acids having 70% by weight or more C36 dimer acid, adipic, azelaic or sebacic acids, neopentyl glycol or a mixture of neopentyl glycol and 1,2-propanediol and acrylic or methacrylic acid.
The polyesters of the present invention can be used as a functional blood partitioning composition and can optionally be formulated together with other ingredients such as suitable filler and compatible surfactant.
The polyesters of the invention can be formulated together with other ingredients, typically a suitable filler and compatible surfactant, into functional blood partitioning compositions. The density of the finished blood partitioning composition is controlled within prescribed limits, so that during centrifugation the composition becomes stably positioned at the interface between the serum or plasma phase and heavier cellular phase and, when centrifugation is terminated, forms a continuous integral barrier within the blood collection vessel to prevent the two phases from recombining or mixing, especially when decanting or pipetting the serum or plasma. The polyester blood partitioning composition can be transferred into the blood collection vessel and cured, preferably by radiation, to increase the viscosity of the polyester composition to the desired level. The polyester-based blood partitioning compositions of the invention are suited for use in TDM procedures.
Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein are to be understood as modified in all instances by the term xe2x80x9caboutxe2x80x9d. Practice within the numerical limits stated is generally preferred. Also, throughout this description, unless expressly stated to the contrary: percent, xe2x80x9cpartsxe2x80x9d of, and ratio values are by weight; the description of a group or class of materials as suitable or preferred for a given purpose in connection with the invention implies that mixtures of any two or more of the members of the group or class are equally suitable or preferred; description of constituents in chemical terms refers to the constituents at the time of addition to any combination specified in the description or of generation in situ by chemical reactions specified in the description, and does not necessarily preclude other chemical interactions among the constituents of a mixture once mixed.
The polyesters according to the invention having the repeating units as set forth above, have molecular weights from about 1,000 to about 5,000 before curing, and can achieve molecular weights from about 5000 to 500,000 after curing. The polyesters of the invention are produced in the form of liquids, having a density at room temperature in the range of from about 1.01 to about 1.09. The inertness of these polyesters makes them useful in TDM programs. The polyesters of the invention are also highly hydrophobic, exhibiting negligible water solubility. The physical and chemical properties of these polyesters are uniformly maintained over extended periods prior to use, as well as during transportation and processing of blood samples. These polyesters have the ability to undergo the ultracentrifugation necessary for the blood partitioning procedure without any detectable adverse effect.
The compositions of this invention have 100 degree C. viscosities (kinematic) in the range of from about 100 to about 1000 centistokes before curing, which after curing can be increased to about 500 to greater than 10,000 centistrokes, and a density in the range of from about 1.015 to about 1.060 g/cm3. More preferably they have a 100 degree C. kinematic viscosity in the range 3,000 to 6,000 and density in the range 1.020 to 1.050 g/cm3.
Polyesters having the above-described properties are especially useful as blood partitioning agents in blood collection vessels where they provide a continuous integral barrier or seal between the serum and clot portions of blood. In other words, the polyester completely partitions the separated phases so that the serum and cellular or clot portions are no longer in contact at any point, forming a unitary seal which firmly adheres to the inner surface of the blood collection vessel. By forming a continuous, integral barrier in this way, it is possible to easily remove the serum or plasma portion by decanting or pipetting, with the clot portion remaining undisturbed in the collection vessel.
The polyesters of this invention comprise the reaction product of a polymeric fatty acid, resulting in the repeating xe2x80x9cAxe2x80x9d unit; a dicarboxylic acid, resulting in the repeating xe2x80x9cBxe2x80x9d unit; a diol, resulting in the repeating xe2x80x9cCxe2x80x9d unit; and a moiety xe2x80x9cDxe2x80x9d having at least one polymerizable carbon-carbon double bond and at least one functional group capable of reacting with the ends of the polyester chain. The molar ratio of the sum of the dicarboxylic acid member and the polymeric fatty acid to the diol member is in the range from about 1:1.5 to about 1:0.67
The xe2x80x9cAxe2x80x9d unit of the invention is the residue of a polymeric fatty acid, particularly preferred is the residue of C36 dimer acid. Suitable polymeric fatty acids have the formula:
HOOCxe2x80x94RAxe2x80x94COOH
wherein RA is an aliphatic or aromatic moiety having from about 20 to about 50 carbon atoms, preferably from about 22 to about 42 carbon atoms. The polymeric fatty acids suitable for use in the polyesters of the invention, are obtained by the polymerization of olefinically unsaturated monocarboxylic acids having from 16 to 22 carbon atoms, such as oleic acid, linolenic acid, linoleic acid, eleostearic acid and the like. Polymeric fatty acids and processes for their production are known to the art and by way of illustration reference may be had to U.S. Pat. Nos. 2,793,219 and 2,955,121, the entire disclosures of which are herein incorporated by reference. Polymeric fatty acids useful for this invention preferably will have as their principal component a C36 dimer acid. C36 dibasic acids are obtained by the dimerization of two moles of a C18 unsaturated monocarboxylic acid such as oleic acid or linoleic acid or mixtures thereof (e.g., tall oil fatty acids). They typically contain 75% by weight or more C36 dimer acid and have an acid value in the range 180-215, saponification value in the range 190-215 and neutral equivalent from 265 to 310. The dimer acids may be hydrogenated prior to use. To increase the C36 dimer content and reduce the amount of by-product acids including unreacted mono-basic acid trimer and higher polymer acids, the polymeric fatty acid can be molecularly distilled or otherwise fractionated. Especially useful polyester compositions are obtained using polymeric fatty acids having C36 dibasic acid contents of 85% by weight or more.
The xe2x80x9cBxe2x80x9d unit of the invention is the residue of a diacid. Diacids suitable for use as the dicarboxylic acid member, component xe2x80x9cBxe2x80x9d of the polyesters, include oxalic acid and dicarboxylic acids of the formula:
HOOCxe2x80x94R1xe2x80x94COOH
where R1 is a divalent alkylene chain having from 1 to 46 carbon atoms, and preferably is selected from the group consisting of divalent aliphatic chains of 1-34 carbon atoms and more preferably of from 3 to 34 carbon atoms; divalent cycloaliphatic chains of 3-34 carbon atoms; arylene chains of from 6-34 carbon atoms, preferably of from 9-34; alkarylene chains of from 7-34 carbon atoms, and alkarylalkylene chains of from 8-34 carbon atoms.
Suitable diacids useful in the practice of the present invention include, but are not limited to malonic acid, succinic acid, methylmalonic acid, fumaric acid, maleic acid, acetylene dicarboxylic acid, glutaric acid, ethylmalonic acid, dimethylmalonic acid, methylsuccinic acid, citraconic acid, glutasconic acid, itaconic acid, mesaconic acid, adipic acid, 2-dimethylsuccinic acid, 3methylglutaric acid, hydromuconic acid, muconic acid, pimelic acid, butylmalonic acid, diethylmalonic acid, 2-dimethylglutaric acid, 2-ethyl, 2-methylsuccinic acid, 3-methyladipic acid, cyclopentanedicarboxylic acid, suberic acid, cyclohexanedicarboxylic acid, isophthalic acid, terephthalic acid, azelaic acid, 5-norbomene-2,3-dicarboxylic acid, phenylmalonic acid, sebacic acid, camphoric acid, 1-cyclohexanediacetic acid, cyclohexylsuccinic acid, benzylmalonic acid, phenylene diacetic acid, phenylsuccinic acid, undecanedioic acid, 3phenylglutaric acid, 1,10-decanedicarboxylic acid, 4-phenylenedipropionic acid, naphthalene dicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 4-biphenyidicarboxylic acid, diphenic acid, hexadecanedioic acid, octadecanedioic acid, octadecenedioic acid, dimer acids and mixtures thereof. Especially preferred are adipic, azelaic, sebacic, and dodecanedioic acids.
It will be apparent to those skilled in the art that the various art-recognized equivalents of the aforementioned dicarboxylic acids, including lower alkylesters, anhydrides and acid chlorides thereof, may be employed in preparing the polyesters of the invention. Accordingly, as used herein, the term xe2x80x9cacidxe2x80x9d is intended to encompass such acid derivatives. Methyl esters are particularly advantageous for the preparation of the polyesters described herein. Mixtures of acids, anhydrides and esters may also be reacted to obtain the desired product.
The equivalents ratio of short-chain dibasic acid (xe2x80x9cBxe2x80x9d component of the polyester) to polymeric fatty acid (xe2x80x9cAxe2x80x9d component of the polyester) will range from about 4:1 to 32:1 and more preferably will be in the range 5:1 to 19:1. An essentially stoichiometric amount of the dibasic acid mixture is reacted with the branched-chain diols(s) to obtain the polyesters.
The xe2x80x9cCxe2x80x9d unit in the polyester of the invention is the residue of a diol. Suitable diols useful in the polyester of the invention comprise one or more esterifiable dihydric alcohol components of the formula:
HOxe2x80x94RCxe2x80x94OH
wherein RC=(CHnRm)k wherein n=0, 1 or 2; R=H, C1 to C10 alkyl, CH2OCH2CH2, CH2CH2OCH2CH2OCH2CH2; m=0, 1 or 2; n+m=2; k=1 to 10.
Preferred diols are branched-chain aliphatic dihydric alcohols having 3 to 8 carbon atoms. Mixtures of branched-chain diols are also advantageously employed as are mixtures of a branched-chain and straight-chain aliphatic saturated diols wherein the branched-chain diol constitutes at least 50 percent by weight, and more preferably, greater than 70 percent by weight of the total diols present. When using a mixture of branched-chain and straight-chain aliphatic saturated diols, the preferred molar ratio of the respective diols is from about 1:1 to about 99:1, preferably from about 3.5:1 to about 99:1, and more preferably from about 5:1 to about 99:1. The hydroxyl groups of the diol may be either primary or secondary, however, diols having tertiary hydroxyl groups are not recommended. For the purpose of this invention a diol containing a secondary hydroxyl group is considered to be a branched-chain diol. Useful branched-chain diols include, but are not limited to, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,4trimethyl-1,3-pentanediol, 3-methyl-2,3-pentanediol, 1,2-propanediol, 1,3butanediol, 1,2-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol and the like. Preferred diols for this invention contain from 3 to 5 carbon atoms and exceptional results are obtained using neopentyl glycol or a mixture of neopentyl glycol and 1,2-propanediol. In one of the preferred embodiments of this invention where a mixture of neopentyl glycol and 1,2-propanediol is used the equivalents ratio of the respective diols ranges from about 1:1 to about 99:1, preferably from about 3.5:1 to about 99:1, and more preferably from about 5:1 to about 99:1. Useful straight-chain (linear) aliphatic diols can have from 2 to 8 carbon atoms and include, but are not limited to, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and the like. Additional useful diols within the scope of the invention are diethylene glycol and triethylene glycol.
Additionally, a dimer diol which is a compound of the formula:
HOxe2x80x94RAxe2x80x94OH
wherein RA is defined as above is within the scope of useful diols for the present invention. These dimer diols are more fully described in U.S. Pat. No. 5,101,009 which is incorporated herein by reference.
D= is a residue of a compound having at least one polymerizable carbon-carbon double bond and at least one functional group capable of reacting with the ends of the polyester chain. The D moiety can be the residue of any ethylenically unsatuarated mono- or poly-functional compound capable of reacting with the ends of the polyester chain, examples of which include, but are not limited to, acrylic acid, methacrylic acid; acrylate or methacrylate esters such as methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, particularly preferred compounds are acrylic and methacrylic alkyl esters wherein the alkyl group has from 1 to 4 carbon atoms; hydroxyalkyl acrylates and methacrylates of the following formula:
CH2=CR2xe2x80x94C(O)Oxe2x80x94R3xe2x80x94OH
wherein R2 is hydrogen or methyl and R3 is a linear or a branched alkylene group having from 2 to 10 carbon atoms, preferably from 2 to 6 carbon atoms, examples of which include but are not limited to, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 3-hydroxypentyl acrylate, 6-hydroxynonyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 2-hydroxypentyl methacrylate, 5-hydroxypentyl methacrylate, 7-hydroxyheptyl methacrylate and 5-hydroxydecyl methacrylate; oligomers substituted with multiple acrylate ester groups mixed with low molecular weight monofunctional, difunctional, or trifunctional acrylate monomers, for example hexanediol diacrylate; vinyl esters, such as vinyl acetate; ethylenically unsaturated monocarboxylic acids and reactive derivatives thereof (acid halide (e.g., chloride), anhydride, ester, salt) examples of which include, but are not limited to, alpha, beta-ethylenically unsaturated carboxylic acids containing from about 3 to about 8 carbon atoms; monovinyl esters of saturated and unsaturated aliphatic, monobasic and polybasic acids, such as the vinyl esters of the following acids: propionic, isobutyric, caproic, oleic, stearic, acrylic, methacrylic, crotonic, succinic, maleic, fumaric, itaconic hexahydrobenzoic, citric, tartaric, etc., as well as the corresponding allyl, methallyl, etc., esters of the aforementioned acids, the itaconic acid monoesters and diesters, such as the methyl, ethyl, butyl esters, etc.; the maleic and fumaric acid monoesters.
Conventional esterification procedures and equipment are used to obtain the polyester of the invention. The reactive components are normally added to the reaction vessel as a unit charge and the reaction mixture is then heated with agitation at a temperature from about 120 degree to about 250 degree C. for a period of time sufficient to substantially complete the esterification reaction. The reaction may be driven to completion by application of vacuum (typically 1-5 mm Hg absolute at about 150 degree to about 250 degree C.) until the desired properties are obtained. Vacuum distillation removes the final traces of water, any excess reactants and small amounts of other volatile materials present in the reaction mixture. Alternatively, all the reactive components except the moiety having at least one polymerizable carbon-carbon double bond and at least one functional group capable of reacting with the ends of the polyester chain can be added to the reaction vessel and heated until they are melted and form a homogeneous mixture at which point the moiety having at least one polymerizable carbon-carbon double bond and at least one functional group capable of reacting with the ends of the polyester chain can be added and the reaction carried out as described previously.
If improvement in color is desired, the polyester may be bleached by any of the well known and accepted bleaching methods, e.g., using hydrogen peroxide or chlorite. Alternatively, the polyester may be decolorized by filtering through a filter aid, e.g., charcoal or bleaching clay.
The rate of esterification can be enhanced by the use of known esterification catalysts. If a catalyst is used it is not necessary that it be present throughout the entire reaction. It is sometimes advantageous in order to obtain products having good color and low acid value, preferably less than 10, to add the catalyst during the final stages of the reaction. At the same time the pressure can be reduced for even better results. While the esterification can be carried out entirely at atmospheric pressure it is most desirable to reduce the pressure, typically to about 1-50 mm Hg. at about 150 degree to about 250 degree C., during the latter stages to facilitate removal of the final traces of water and excess glycol which may be present and to reduce the acid value to the desired level. Suitable esterification catalysts for enhancing the rate of esterification of free carboxyl groups include phosphoric acid, sulfuric acid, toluenesulfonic acid, methane sulfonic acid, sodium carbonate and the like. The amount of such catalyst may vary widely, but most often will be in an amount from about 0.1% to about 0.5% by weight, based on the total reactant charge. Catalysts useful for effecting ester interchange include dibutyltin diacetate, stannous oxalate, alkyl tin oxides, such as dibutyltin oxide; tetrabutyl titanate, zinc acetate and the like. These catalysts are generally employed in an amount ranging from about 0.01% to 0.05% by weight, based on the total resistant charge. When such catalysts are used, it is not necessary that they be present throughout the entire reaction. It is sometimes advantageous in order to obtain products having good color and relatively low acid value, on the order of 2 mg KOH/gm, or less, to add the catalyst during the final stages of the reaction. Upon completion of the reaction, the catalyst may be deactivated and removed by filtration or other conventional means.
Reaction solvents, such as benzene, toluene, xylene and the like may be employed for the reaction. However, the use of reaction solvents is not necessary. It is generally considered desirable to conduct the reaction without solvents since the resultant polyester can be directly used as it is obtained from the reaction vessel. A small excess (based on the equivalents of acid present) of a volatile diol component may be used if desired. The excess diol serves as the reaction medium and reduces the viscosity of the reaction mixture. The excess diol is distilled off as the esterification is carried to completion and may be recycled to the reactor, if desired. Generally, about 20% by weight excess volatile diol will suffice. The preferred volatile diol is 1,2-propanediol. It will be evident to one skilled in the art that, if the esterification is carried out in a continuous or semi-continuous manner, it will be necessary to replenish the reactants as they are consumed. Multiple vessel arrangements can be used for continuous production of these polyesters.
The polyesters of this invention can optionally be made into blood partitioning compositions by formulating with up to about 35 weight percent of an inert filler. These fillers can be added to the polyester to increase the density of the polyester composition since all of the commonly used fillers have densities greater than that of the polyester. The fillers also impart thixotropic properties to the barrier compositions. Polyesters containing small amounts of inert fillers, particularly silica, exhibit improved flow characteristics during centrifuging so that the compositions more readily located at the interface between the light and heavy phases. When centrifuging is terminated, however, the compositions return to their original state and form a highly viscous, continuous and integral barrier between the clot and serum portions. The inert fillers used are in a finely powdered state and preferably constitute from about 0.5 to 25 weight percent of the total composition. While silica, including the various amorphous form of silica, such as precipitated silica and fumed silica, and the hydrophobic silicas treated with silanes or polysiloxanes, are particularly useful with the polyesters of this invention, other inert materials such as alumina, talc and other silicates, bentonite and other naturally occurring montmorillonite-rich mineral clays can also be employed.
Preparation of blood partitioning compositions using the polyesters of the invention may be carried out in the manner described in commonly owned U.S. Pat. Nos. 4,101,422 and 4,148,764, the entire disclosures of which are incorporated by reference in the present specification, as if set forth herein in full.
The present invention also pertains to a method of partitioning blood comprising the steps of
(i) placing an effective amount of the polyester of the invention described above into a blood collecting tube;
(ii) curing the polyester of the invention;
(iii) introducing the blood to be partitioned into the tube, and
(iv) effecting the partitioning of the said blood through the action of centrifugal force.
One method by which the new compositions of this invention can be cured or converted to the infusible state, alone or in admixture with other monomers or polymers is by exposure to radiation alone or in the presence of radical generating catalysts such as benzoin, benzoin ethers, and Michler""s Ketone. The free radical initiator is typically present at from about 0.01 to about 20% by weight of the polymerizable/curable components. Examples of useful radiation include ultraviolet light and ionizing radiation such as generated by X-Ray machines; electron accelerators such as van der Graaf machines, travelling wave linear accelerators, particularly of the type described in U.S. Pat. No. 2,736,609, natural and synthetic radioactive material, for example cobalt 60, etc. To ensure that the composition does not prematurely polymerize, a free radical inhibitor may be added to the polymerizable composition. Examples of suitable inhibitors include hydroquinone and the methyl ether thereof or butylated hydroxy toluene at a level of from about 5 ppm to about 2000 ppm by weight of the polymerizable components. Additives which are particularly useful in prolonging the shelf-life of the composition can also be used, e.g., ultra-violet stabilizers such as FLORSTAB(copyright) UV-II from Kromachem.
In the method of partitioning blood, according to the invention, the composition, optionally containing a photoinitiator, is placed in a blood collection tube and subsequently exposed to a radiation source until the desired viscosity is obtained. Sources of radiant energy appropriate for initiating cure of the formulations have been described extensively in the literature and are well known to those skilled in the art. These include various sources of particulate and non-particulate radiation producing wavelengths generally less than 700 nanometers. Especially useful is actinic radiation in the 180-440 nm range which can be conveniently obtained by use of one of several commercially available ultra-violet sources specifically intended for this purpose. These include low, medium and high pressure mercury vapor lamps, He-Cd and Ar lasers, xenon arc lamps, etc. Photoinitiator systems having a corresponding sensitivity to light in this wave band can be incorporated into the formulation and upon irradiation lead to the formation of reactive species capable of initiating free radical polymerization. Similarly, free radical polymerization may be induced by exposure of the formulation to an electron beam without the use of a photoinitiator. Equipment capable of generating a curtain of electrons with energies between 150 and 300 KeV is particularly suitable for this purpose and its use is well documented in the literature.
Particularly preferred sources of radiation emit electromagnetic radiation predominantly in the ultra-violet band. When such a source is used, the polymerizable composition preferably contains a photoinitiator susceptible to ultra-violet radiation, e.g., benzoin, benzoin ethers, alpha, alpha-dimethoxy-alpha-phenylacetophenone, diethoxyacetophenone, alpha-hydroxy-alpha, alpha-dimethylacetophenone, and 1-benzoylcyclohexanol.
The amount of radiation necessary to cure the composition will of course depend on the angle of exposure to the radiation, the quantity of composition placed in the collection tube, and the amount of polymerizable groups in the partitioning composition, as well as the presence or absence of a free radical initiating catalyst. For any given composition, experimentation to determine the amount of radiation sensitive pi bonds not cured following exposure to the radiation source is the best method of determining the amount and duration of the radiation required. Typically, an ultra-violet source with a wavelength between 200 and 420 nm (e.g., a filtered mercury arc lamp) is directed at a measured quantity of partitioning composition carried on a conveyor system which provides a rate of passage past the ultra-violet source appropriate for the radiation absorption profile of the composition (which profile is influenced by the degree of cure desired, the effective quantity of partitioning composition to be cured, and the rate of polymerization of the composition).
Determination of the extent of interaction between the polyesters of the invention and commonly monitored drugs may be carried out using well known recovery experiments and drug measurement techniques, such as, gas chromatography, gas-liquid chromatography, high-performance liquid chromatography, thin layer chromatography or immunoassay techniques, including radioimmunoassay, enzyme immunoassay, fluorescence polarization immunoassay, nephelometric assay, and the like. A variety of suitable procedures are reported in the literature. See, for example, Bergqvist, et al., supra. Such determinations may be carried out using human serum, or commercially available bovine serum, if desired.

Method and partitioning blood using polyesters


A elevated, portable non-slip cutting board for use in cutting and supporting foodstuffs, household and miscellaneous items comprising a rigid, planar baseboard to which is fixed a traction means having at least 13 downwardly directed, spaced apart projections of such a height, width, and spatial arrangement as to provide support, stability, and the free flow of fluid underneath the cutting board and which provides enhanced traction to retard slippage of the cutting board during the cutting or support process.

1. Field of the Invention
This invention relates generally to a cutting board for safely supporting or cutting foodstuffs, household items and other materials. Safety results by employment of downwardly directed projections from the traction surface which sufficiently raise the cutting board off the countertop, floor or planar surface and provide gripping non-slip traction during the cutting or support process, allowing juice and other fluids to flow under the board and avoiding pooling under and around or planing of the board thereby minimizing the growth of microbes and diminishing the likelihood of a slippery and dangerous condition.
2. Description of Related Art
Cutting boards are well known in the art and are primarily designed to provide a surface on which to cut food and other materials while protecting the countertop, but most fail to provide a reliably safer device. Cutting food stuffs and other materials is a potentially dangerous task, i.e. using a sharp knife or cleaver under pressure against often times frozen, hard, or cumbersome items, often in a wet environment created from fluids seeping from items during the cutting process and invariably without use of any safety or protective equipment or gear. Foods oozing fluids when cut are frequently encountered on cutting boards. The household kitchen counter is the most frequent surface on which such cutting occurs and family members during regular day to day meal preparation are the most frequent users. This environment and type of unprotected untrained user presents a situation which demands extra safety precautions.
The structure of cutting boards known in the art either fails to address this safety hazard or incompletely or inadequately solves the problem. For example, U.S. Pat. No. 5,984,294 issued to Bodomolny discloses a cutting board with a replaceable cutting surface and traction elements in the form of rubber feet individually attached, spaced rubber treads or rubber grip fastened by adhesives or stainless steel screws on the bottom surface. Bodomolny does not teach or suggest the use of unitarily molded traction elements, parameters related to height, quantity, spacing, shape, surface area, and the overall bottom surface configuration set forth in the present invention. Planing and reduced traction resulting from fluid dynamics as related to the available space under the cutting board and traction resulting therefrom are never addressed in terms of the height, number, configuration and individual shape of the projections, on which the present invention focuses.
U.S. Pat. No. 4,930,759 issued to Potter discloses a cutting board with a spiked platform to engage and retain food to be cut, a knife blade guide, a plurality of channeled depressions on the top surface for the temporary retention of juices and food related debris as opposed to the raised bottom surface for traction and to prevent slippage created by the planing effect of accumulated fluid in direct contact with the cutting board disclosed in the present invention. Potter provides a food retaining element that applies to the item to be cut as opposed to restricting movement of the cutting board apparatus on the countertop.
U.S. Pat. No. 5,527,022 issued to Gibson discloses a rectangular cutting board with a leveling component composed of a flexible, friction, enhancing material such as rubber, located at the four corners of the board. The present invention enhances traction by increasing the number of surface area contacts with an overall plurality of flexible projections (a minimum of 13 is preferred) molded or configured, or attached as part of, and which are spatially arranged, and spaced apart over the entire underside of a traction surface, not just the four corners. The location and plurality (at least 13) of flexible friction contacts in the present invention not only enhances the ability of the cutting board to support the item placed on the board surface, which is often heavy, but also increases the traction arising from the greater number of elevating contact points and greater surface area of the projections in contact with the countertop. When there are only a few projections located only at the corners, the cutting board may actually be subject to slippage arising not only, from the minimal number and amount of surface contact area, but also from the bowing of the cutting board under the weight of the item placed on the board surface. When an item to be cut is heavy, the weight, distributed in the central most portion of the cutting board, with support only at the four corners, without additional support underneath, may actually reduce surface area contact at the corners. Center weight compression caused the supports to tilt inwardly which not only decreases the amount of friction contact but also permits fluid to flow under the projections contact thereby allowing planing to occur. This situation may even worsen when the downward cutting force adds even more non-supported force directed centrally on the cutting board.
Applicant believes that when at least 13 flexible friction contact projections providing a predetermined surface area contact are spatially arranged over the entire bottom of the traction surface and are spaced apart, the weight of the item to be cut is not only supported directly thereunder, but also, the weight of the item enhances the force of frictional contact of the projections.
Although non-slip cutting boards have long existed as butcher block countertops and similar large, heavy and stationary devices, these devices take up space, are cumbersome, and neither portable nor easily or adequately cleaned, such as in a dishwasher.
The need arises not only, for a cutting board which provides overall traction and diminishes slippage of the board, but also enhances support of food or other materials over the entire cutting surface, and is elevated to channel fluids underneath the cutting board, is portable, space saving, dishwasher safe, and more sanitary.
The present invention provides a cutting board designed to satisfy the aforementioned deficiencies.
A food cutting board comprising an elevated, non-slip cutting and support board having a baseboard fused with or fixedly attached to and supported by a bottom traction surface having a patterned plurality of spaced apart flexible projections with flat surfaces that provide a predetermined total surface area contact which grip the countertop surface for traction and for enhanced support of food or other objects, particularly in the central portion of the cutting board during the cutting process. Due to the elevated position of the cutting and support surface created by the plurality of projections, an area underneath the cutting board exists to accommodate and channel away juices and fluids. The channels for fluids under the cutting board diminishes the likelihood of microbial growth on and around the board due to the increased flow and aeration available under the board rather than accumulating about the perimeter of the board nearer the food as is the situation when the cutting board sits flush on the countertop during use. The plurality of projections and the total surface area contact for traction reduces the likelihood of a planing effect which is more likely with no elevation of the cutting board above the countertop and/or friction contact projections located at only the four corners of the underside of the cutting board. The chance of slippage and potential for physical injury is reduced when planing is avoided. The elevation is such as to allow free flow of fluid and air thereunder but not so high as to complicate use or create instability.
This cutting board for inhibiting movement or slippage on the countertop, comprises a rigid, durable, flat, planar baseboard with an overlying, abutting, flexible bottom traction surface with downwardly directed, spaced apart projections of equal height, but which may be of equal or variable size and shape and which extend over substantially the entire bottom traction surface.
The preferred shape of the baseboard and traction surface is substantially rectangular, however any geometric shape, e.g. hexagonal, octagonal, circular, oval, triangular, rhomboidal, free form shape or shape designed to resemble animate or inanimate objects, could be used so long as sized to accommodate the material to be cut or supported.
A plurality of projections having substantially flat bottoms, preferably integrally molded and directed downwardly from the underside of the traction surface are of a height to allow sufficient fluid flow underneath while maintaining stability and ease of use. These projections are situated and spatially arranged uniformly or sporadically over substantially the entire underside of the traction surface in a manner that fosters stability and the free flow of fluid thereunder. The projections are preferably flat topped, cubic, truncated cone, pyramidical columnar, hemispherical, discoidal, polyhedral, discoidal, cylindrical, or in the form of longitudinal concentric or spiral ridges, or other 3-dimensional geometric or free form shape, configuration and dimension to elevate the baseboard off the support surface while providing support, traction and flow through spaces thereunder and a predetermined contact surfaced area available to engage the countertop.
An elevated, non-slip cutting board assembly which is composed of a durable, continuous, flat planar, rigid body having an upper surface suitable for engagement with a knife or other cutting blade and a base having a substantially planar cutting surface and an underlying, abutting traction component of shape and size identical to the baseboard. The traction component is comprised of a planar top surface and bottom surface having at least 13 downwardly directed, spaced apart projections of equal height, spatially arranged over and emanating from the bottom of the traction component and extending substantially out to and along the perimeter of said cutting board.
The spaced apart projections support and elevate the cutting board body above the countertop providing sufficient air channels under the cutting board to allow fluid to flow underneath the cutting board. The projections are spatially arranged over substantially the entire underside of the traction surface to provide a predetermined minimum amount of surface area engagement with a countertop surface for greater support and enhanced frictionally gripping of the cutting board with the countertop.
A more specific characterization of the present invention is that of an elevated, non-slip cutting board which is composed of a rectangular, substantially flat, polyethylene baseboard and an underlying, abutting flexible silicon bottom traction element of a shape substantially identical to the baseboard. The traction component has top and bottom flat surfaces. From the bottom surface of the traction component emanates a plurality of downwardly directed, spaced apart octahedron shaped projections of equal height, spatially arranged thereon and extending substantially to and along the perimeter of the cutting board. The total combined surface area of contact of the projections with the countertop as compared to the amount of overall planar area of the cutting board is between, 3:4 and 1:10. The cutting board further includes a human hand-sized opening for use as a handle for carrying, hanging, and stabilizing the cutting board during use.
It is a general object of the present invention to provide a portable, dishwasher safe, elevated cutting board supported thereunder by a plurality of projections which grip the countertop, channel juices and excess fluids thereunder, provide greater support, reduce slippage, minimize the likelihood of microbal growth thereon or around, and which does not mar the countertop or surface on which the cutting board rests.
In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.


The present invention includes a layered liquid detergent composition in a water-soluble single use package, the composition comprising at least two layers, the at least two layers comprising a surfactant, a colored inorganic electrolyte, and water. In the inventive compositions at least one of the layers (the electrolyte layer) is colored. Preferred compositions include a dye in the surfactant layer, so that the compositions contain at least two layers, with two distinct colors. Preferred compositions are transparent and are enclosed within a transparent body.

A water-soluble single-use package comprising multiple, distinctly colored layers of liquid detergent in the water-soluble body portion and a process of its preparation.
Detergent compositions are provided in many forms, of which granular and liquid compositions are the most prevalent. More recently, unit dose forms of detergent have been proposed in the form of compressed tablets of detergent powder or water-soluble packages, which are consumed during a single cleaning application. The unit dose forms are preferred by some consumers, in that the dose is pre-measured and, consequently, the unit dose form is faster, easier and less messy to use. Water-soluble packages filled with liquid detergent composition are desired especially by consumers who are used to liquid detergents.
Water-soluble unit dose packages containing liquids are known. See, for instance, Kennedy (U.S. Pat. No. 4,973,416), Dickler et al. (U.S. Pat. No. 6,037,319), Haq (U.S. Pat. No. 4,416,791) and Richardson (U.S. Pat. No. 4,115,292). The packages may contain various amounts, including relatively high, amounts of water. See for instance WO 94/14941, EP 518 689, WO 97/27743, and JP 06/340,899.
It is sometimes desirable to separate various ingredients of the detergent composition. See for instance WO 01/60966 disclosing a multi-compartment water-soluble pouch. It is also desirable to increase the visual appeal of the package and, also, provide a unique appearance to be associated by consumers with a particular product. In addition, it is desirable to provide a visual signal to a consumer of the presence of special (e.g., benefit) ingredient in the composition.
EP 116422, EP 175485, GB 1247189, WO 99/47635, and Ginn (U.S. Pat. No. 4,348,292) disclose dual layer liquid cleaning compositions in a bottle or a water insoluble package. The layers are achieved by employing an electrolyte, which when added to an aqueous surfactant solution, forces the separation of the surfactant from the aqueous phase. The phenomenon of separating an organic component from an aqueous layer, by the addition of a salt (electrolyte) is known as xe2x80x9csalting out.xe2x80x9d The salt increases the ionic character of water and drives the organic, less polar, component away.
It is desirable to provide a layered liquid detergent composition in a water-soluble single use package. Unfortunately, this presents a problem since bottled layered compositions frequently contain ingredients which would threaten the integrity of the water-soluble package. An especially unique challenge of providing layers of liquid laundry detergent compositions within a water-soluble package is that the integrity of the water soluble package has to be maintained, despite the presence of water in the composition. Furthermore, if layers are desired of different color, a problem exists, since most dyes partition in organic layer. The dyes that partition into an electrolyte layer, do not as a rule do so to the exclusion of the surfactant layer and thus there is a leaking of color into the surfactant layer.
The present invention includes a layered liquid detergent composition in a water-soluble single use package, the composition comprising at least two layers, with a surfactant, a transition metal inorganic electrolyte, water and optionally other ingredients distributed within the layers. The inventive compositions include water, yet the water-soluble package remains intact on storage.
The following detailed description and the examples illustrate some of the effects of the inventive compositions. The invention and the claims, however, are not limited to the following description and examples.
Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word xe2x80x9cabout.xe2x80x9d All amounts are by weight of the liquid detergent composition, unless otherwise specified.
It should be noted that in specifying any range of concentration, any particular upper concentration can be associated with any particular lower concentration.
For the avoidance of doubt the word xe2x80x9ccomprisingxe2x80x9d is intended to mean xe2x80x9cincludingxe2x80x9d but not necessarily xe2x80x9cconsisting ofxe2x80x9d or xe2x80x9ccomposed of.xe2x80x9d In other words, the listed steps or options need not be exhaustive.
xe2x80x9cWater-soluble bodyxe2x80x9d as used herein means soluble in cold water, i.e. soluble at 5xc2x0 C. and above.
xe2x80x9cLiquidxe2x80x9d as used herein means that a continuous phase or predominant part of the composition is liquid and that a composition is flowable at 20xc2x0 C.
xe2x80x9cColored inorganic electrolytexe2x80x9d as used herein means an electrolyte containing a transition metal cation, which in aqueous solution produces color.
xe2x80x9cTransparentxe2x80x9d as used herein includes both transparent and translucent and means that an ingredient, or a mixture, or a phase, or a composition, or a package according to the invention preferably has a transmittance of more than 25%, more preferably more than 30%, most preferably more than 40%, optimally more than 50% in the visible part of the spectrum (approx. 410-800 nm). Alternatively, absorbency may be measured as less than 0.6 (approximately equivalent to 25% transmitting) or by having transmittance greater than 25% wherein % transmittance equals: {fraction (1/10)}absorbancyxc3x97100%. For purposes of the invention, as long as one wavelength in the visible light range has greater than 25% transmittance, it is considered to be transparent/translucent.
The term xe2x80x9ccompositionxe2x80x9d or xe2x80x9cliquid detergent compositionxe2x80x9d as used herein means the final detergent composition (i.e., the detergent composition itself, but not the water-soluble body), including at least two layers. The at least two layers comprise between them a surfactant, a colored inorganic electrolyte, water and any optional ingredients described below.
The package is preferably made of a clear, sealable, cold water soluble film such as polyvinyl alcohol. Thickness could range from 25 to 100 xcexcm, more preferably from 35 to 80 xcexcm, most preferably from 45 to 55 xcexcm. Other materials from which the package can be made include but are not limited to methyl hydroxy propyl cellulose and polyethylene oxide. Polyvinyl alcohol is preferred due to its ready availability and low cost. One supplier of polyvinyl alcohol film is Monosol Inc. European suppliers of suitable films include but are not limited to Monosol supplied by Monosol Inc. or PT supplied by Aicello or K-series supplied by Kurary or Hydrafilm supplied by Rainier Specialty polymers ltd, or QSA series by Polymer Films, Inc.
Preferably the water-soluble film of the base wall is the same material as that used to make the body wall. Both thermoforming and cold forming (e.g., with water) are possible.
The essential ingredients of the inventive laundry compositions are surfactant, a colored inorganic electrolyte and water.
Surfactant
The compositions of the invention contain one or more surface active agents (surfactants) selected from the group consisting of anionic, nonionic, cationic, ampholytic and zwitterionic surfactants or mixtures thereof. The preferred surfactant detergents for use in the present invention are mixtures of anionic and nonionic surfactants although it is to be understood that any surfactant may be used alone or in combination with any other surfactant or surfactants. The surfactant should comprise at least 5%, e.g., 5% to 80%, preferably at least 10% to 80%, more preferably 15% to 40%; even more preferably 15% to 35% of the composition.
Nonionic Surfactant
Nonionic synthetic organic detergents which can be used with the invention, alone or in combination with other surfactants, are described below. Nonionic surfactants are typically included.
Preferred nonionic surfactants are nonionic surfactants which are pourable liquids, gels or pastes at 25xc2x0 C. Nonionic detergent surfactants normally have molecular weights of from about 300 to about 11,000. Mixtures of different nonionic detergent surfactants may also be used, provided the mixture is a liquid gel or paste at 25xc2x0 C. Optionally, the composition may comprise one or more nonionic surfactants which are solid at 25xc2x0 C. These dissolved and/or dispersed in either or both liquid layers.
As is well known, the nonionic detergents are characterized by the presence of an organic hydrophobic group and an organic hydrophilic group and are typically produced by the condensation of an organic aliphatic or alkyl aromatic hydrophobic compound with ethylene oxide (hydrophilic in nature). Typical suitable nonionic surfactants are those disclosed in U.S. Pat. Nos. 4,316,812 and 3,630,929 and applicants published European specification EP-A-225,654.
Usually, the nonionic detergents are polyalkoxylated lipophiles wherein the desired hydrophile-lipophile balance is obtained from addition of a hydrophilic polyalkoxy group to a lipophilic moiety. A preferred class of nonionic detergent is the alkoxylated alkanols wherein the alkanol is of 9 to 18 carbon atoms and wherein the number of moles of alkylene oxide (of 2 or 3 carbon atoms) is from 3 to 12. Of such materials it is preferred to employ those wherein the alkanol is a fatty alcohol of 9 to 11 or 12 to 15 carbon atoms and which contain from 5 to 8 or 5 to 9 alkoxy groups per mole.
Exemplary of such compounds are those wherein the alkanol is of 12 to 15 carbon atoms and which contain about 7 ethylene oxide groups per mole, e.g. Neodol(copyright) 25-7 and Neodol(copyright) 23(copyright)-6.5, which products are made by Shell Chemical Company, Inc. The former is a condensation product of a mixture of higher fatty alcohols averaging about 12 to 15 carbon atoms, with about 7 moles of ethylene oxide and the latter is a corresponding mixture wherein the carbon atoms content of the higher fatty alcohol is 12 to 13 and the number of ethylene oxide groups present averages about 6.5. The higher alcohols are primary alkanols.
Other useful nonionics are represented by the commercially well-known class of nonionics sold under the trademark Plurafac(copyright). The Plurafacs(copyright) are the reaction products of a higher linear alcohol and a mixture of ethylene and propylene oxides, containing a mixed chain of ethylene oxide and propylene oxide, terminated by a hydroxyl group. Examples include C13-C15 fatty alcohol condensed with 6 moles ethylene oxide and 3 moles propylene oxide, C13-C15 fatty alcohol condensed with 7 moles propylene oxide and 4 moles ethylene oxide, C13-C15 fatty alcohol condensed with 5 moles propylene oxide and 10 moles ethylene oxide, or mixtures of any of the above.
Another group of liquid nonionics are commercially available from Shell Chemical Company, Inc. under the Dobanol(copyright) trademark: Dobanol(copyright) 91-5 is an ethoxylated C9-C11 fatty alcohol with an average of 5 moles ethylene oxide and Dobanol(copyright) 23-7 is an ethoxylated C12-C13 fatty alcohol with an average of 7 moles ethylene oxide per mole of fatty alcohol.
In the compositions of this invention, preferred nonionic surfactants include the C12-C15 primary fatty alcohols with relatively narrow contents of ethylene oxide in the range of from about 7 to 9 moles, and the C9 to C11 fatty alcohols ethoxylated with about 5-6 moles ethylene oxide.
Another class of nonionic surfactants which can be used in accordance with this invention are glycoside surfactants. Glycoside surfactants suitable for use in accordance with the present invention include those of the formula:
ROxe2x80x94Rxe2x80x2Oyxe2x80x94(Z)x.
wherein R is a monovalent organic radical containing from about 6 to about 30 (preferably from about 8 to about 18) carbon atoms; Rxe2x80x2 is a divalent hydrocarbon radical containing from about 2 to 4 carbons atoms; 0 is an oxygen atom; y is a number which can have an average value of from 0 to about 12 but which is most preferably zero; Z is a moiety derived from a reducing saccharide containing 5 or 6 carbon atoms; and x is a number having an average value of from 1 to about 10 (preferably from about 1.5 to about 10).
A particularly preferred group of glycoside surfactants for use in the practice of this invention includes those of the formula above in which R is a monovalent organic radical (linear or branched) containing from about 6 to about 18(especially from about 8 to about 18) carbon atoms; y is zero; z is glucose or a moiety derived therefrom; x is a number having an average value of from 1 to about 4 (preferably from about 1 to 4).
Nonionic surfactants particularly useful for this application include, but are not limited to: alcohol ethoxylates (e.g. Neodol(copyright) 25-9 from Shell Chemical Co.), alkyl phenol ethoxylates (e.g. Tergitol(copyright) NP-9 from Union Carbide Corp.), alkylpolyglucosides (e.g. Glucapon(copyright) 600CS from Henkel Corp.), polyoxyethylenated polyoxypropylene glycols (e.g. Pluronic((copyright) L-65 from BASF Corp.), sorbitol esters (e.g. Emsorb(copyright) 2515 from Henkel Corp.), polyoxyethylenated sorbitol esters (e.g. Emsorb(copyright) 6900 from Henkel Corp.), alkanolarnides (e.g. Alkarnide(copyright) DC212/SE from Rhone-Poulenc Co.), and N-alkypyrrolidones (e.g. Surfadone(copyright) LP-100 from ISP Technologies Inc.).
Mixtures of two or more of the nonionic surfactants can be used.
Anionic Surfactant
Anionic surface active agents which may be used in the present invention are those surface active compounds which contain a long chain hydrocarbon hydrophobic group in their molecular structure and a hydrophilic group, i.e.; water solubilizing group such as sulfonate, sulfate or carboxylate group. The anionic surface active agents include the alkali metal (e.g. sodium and potassium) water soluble higher alkyl benzene sulfonates, alkyl sulfonates, alkyl sulfates and the alkyl polyether sulfates. They may also include fatty acid or fatty acid soaps. The preferred anionic surface active agents are the alkali metal, ammonium or alkanolamide salts of higher alkyl benzene sulfonates and alkali metal, ammonium or alkanolamide salts of higher alkyl sulfonates. Preferred higher alkyl sulfonates are those in which the alkyl groups contain 8 to 26 carbon atoms, preferably 12 to 22 carbon atoms and more preferably 14 to 18 carbon atoms. The alkyl group in the alkyl benzene sulfonate preferably contains 8 to 16 carbon atoms and more preferably 10 to 15 carbon atoms. A particularly preferred alkyl benzene sulfonate is the sodium or potassium dodecyl benzene sulfonate, e.g. sodium linear dodecyl benzene sulfonate.
The primary and secondary alkyl sulfonates can be made by reacting long chain alpha-olefins with sulfites or bisulfites, e.g. sodium bisulfite. The alkyl sulfonates can also be made by reacting long chain normal paraffin hydrocarbons with sulfur dioxide and oxygen as described in U.S. Pat. Nos. 2,503,280, 2,507,088, 3,372, 188 and 3,260,741 to obtain normal or secondary higher alkyl sulfonates suitable for use as surfactant detergents.
The alkyl substituent is preferably linear, i.e. normal alkyl, however, branched chain alkyl sulfonates can be employed, although they are not as good with respect to biodegradability. The alkane, i.e. alkyl, substituent may be terminally sulfonated or may be joined, for example, to the carbon atom of the chain, i.e. may be a secondary sulfonate. It is understood in the art that the substituent may be joined to any carbon on the alkyl chain. The higher alkyl sulfonates can be used as the alkali metal salts, such as sodium and potassium. The preferred salts are the sodium salts. The preferred alkyl sulfonates are the C10 to C18 primary normal alkyl sodium and potassium sulfonates, with the C10 to C15 primary normal alkyl sulfonate salt being more preferred.
Mixtures of higher alkyl benzene sulfonates and higher alkyl sulfonates can be used as well as mixtures of higher alkyl benzene sulfonates and higher alkyl polyether sulfates.
Also normal alkyl and branched chain alkyl sulfates (e.g., primary alkyl sulfates) may be used as the anionic component).
The higher alkyl polyether sulfates used in accordance with the present invention can be normal or branched chain alkyl and contain lower alkoxy groups which can contain two or three carbon atoms. The normal higher alkyl polyether sulfates are preferred in that they have a higher degree of biodegradability than the branched chain alkyl and the lower poly alkoxy groups are preferably ethoxy groups.
The preferred higher alkyl poly ethoxy sulfates used in accordance with the present invention are represented by the formula:
Rxe2x80x2xe2x80x94O(CH2 CH2 O)pxe2x80x94SO3 M,
where Rxe2x80x2 is C8 to C20 alkyl, preferably C10 to C18 and more preferably C12 to C15; p is 2 to 8, preferably 2 to 6, and more preferably 2 to 4; and M is an alkali metal, such as sodium and potassium, or an ammonium cation. The sodium and potassium salts are preferred.
A preferred higher alkyl poly ethoxylated sulfate is the sodium salt of a triethoxy C12 to C15 alcohol sulfate having the formula:
C12-15xe2x80x94Oxe2x80x94(CH2 CH2 O)3xe2x80x94SO3 Na
Examples of suitable alkyl ethoxy sulfates that can be used in accordance with the present invention are C12-15 normal or primary alkyl triethoxy sulfate, sodium salt; n-decyl diethoxy sulfate, sodium salt; C12 primary alkyl diethoxy sulfate, ammonium salt; C12 primary alkyl triethoxy sulfate, sodium salt: C15 primary alkyl tetraethoxy sulfate, sodium salt, mixed C14-15 normal primary alkyl mixed tri- and tetraethoxy sulfate, sodium salt; stearyl pentaethoxy sulfate, sodium salt; and mixed C10-18 normal primary alkyl triethoxy sulfate, potassium salt.
The normal alkyl ethoxy sulfates are readily biodegradable and are preferred. The alkyl poly-lower alkoxy sulfates can be used in mixtures with each other and/or in mixtures with the above discussed higher alkyl benzene, alkyl sulfonates, or alkyl sulfates.
The alkali metal higher alkyl poly ethoxy sulfate can be used with the alkylbenzene sulfonate and/or with an alkyl sulfonate or sulfonate, in an amount of 0 to 70%, preferably 10 to 50% and more preferably 10 to 20% by weight of entire composition.
Anionic surfactants particularly useful for this application include, but are not limited to: linear alkyl benzene sulfonates (e.g. Vista(copyright) C-500 from Vista Chemical Co.), alkyl sulfates (e.g. Polystep(copyright) B-5 from Stepan Co.), polyoxyethylenated alkyl sulfates (e.g. Standapol(copyright) ES-3 from Stepan Co.), alpha olefin sulfonates (e.g. Witconate(copyright) AOS from Witco Corp.), alpha sulfo methyl esters (e.g. Alpha-Step(copyright) MC-48 from Stepan Co.), alkyl ether sulfates and isethionates (e.g. Jordapon(copyright) Cl from PPG Industries Inc.).
Anionic surfactants may be added pre-neutralized or, preferably, may be formed in situ, by neutralizing a precursor acid (fatty acid in the case of soaps). Further, the anionic precursor or fatty acid should be over-neutralised (i.e. there should be an excess of the alkaline material used to form the counter-ion). Inorganic salt, preferably, sodium or potassium salt of the anionic precursor acid is preferred to improve detergency, but organic salt results in improved transparency.
Cationic Surfactants
Many cationic surfactants are known in the art, and almost any cationic surfactant having at least one long chain alkyl group of about 10 to 24 carbon atoms is suitable in the present invention. Such compounds are described in xe2x80x9cCationic Surfactantsxe2x80x9d, Jungermann, 1970, incorporated by reference.
Specific cationic surfactants which can be used as surfactants in the subject invention are described in detail in U.S. Pat. No. 4,497,718, hereby incorporated by reference.
As with the nonionic and anionic surfactants, the compositions of the invention may use cationic surfactants alone or in combination with any of the other surfactants known in the art. Of course, the compositions may contain no cationic surfactants at all.
Amphoteric Surfactants
Ampholytic synthetic detergents can be broadly described as derivatives of aliphatic or aliphatic derivatives of heterocyclic secondary and tertiary amines in which the aliphatic radical may be a straight chain or a branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and at least one contains an anionic water-solubilizing group, e.g. carboxylate, sulfonate, sulfate. Examples of compounds falling within this definition are sodium 3(dodecylamino)propionate, sodium 3-(dodecylamino)propane-1-sulfonate, sodium 2-(dodecylamino)ethyl sulfate, sodium 2-(dimethylamino)octadecanoate, disodium 3-(N- carboxymethyldodecylamino)propane 1-sulfonate, disodium octadecyl- imminodiacetate, sodium 1-carboxymethyl-2-undecylimidazole, and sodium N, N-bis(2-hydroxyethyl)-2-sulfato-3-dodecoxypropylamine. Sodium 3-(dodecylamino)propane-l-sulfonate is preferred.
Zwitterionic surfactants can be broadly described as derivatives of secondary and tertiary amines, derivatives of heterocyclic secondary and tertiary amines, or derivatives of quaternary ammonium, quaternary phosphonium or tertiary sulfonium compounds. The cationic atom in the quaternary compound can be part of a heterocyclic ring. In all of these compounds there is at least one aliphatic group, straight chain or branched, containing from about 3 to 18 carbon atoms and at least one aliphatic substituent containing an anionic water solubilizing group, e. g., carboxy, sulfonate, sulfate, phosphate, or phosphonate.
Specific examples of zwitterionic surfactants which may be used are set forth in U.S. Pat. No. 4,062,647, hereby incorporated by reference.
Preferably, the surfactant in the laundry compositions of the invention is anionic and/or nonionic, especially linear alkylbenzene sulfonate, alkyl ether sulfate, alcohol ethoxylates and mixtures thereof.
For higher foaming formulations (top-loading washing machines), mixtures of anionic and nonionic surfactants are especially preferred, for optimum greasy stain and particulate soil removal. When mixtures are used, the most effective mixtures employ anionic to nonionic ratio of from 10: 1 to 1:10, preferably from 5:1 to 1:5, most preferably from 3:1 to 1:3.
When low foaming formulations are desired, e.g., for front-loading machines, nonionic surfactants are employed, in the absence of, or lower levels of, anionic surfactants, alone or in combination with cationic surfactants and/or antifoams.
Electrolyte
The electrolyte employed in the present invention contains a transition metal cation, such that the electrolytes (salts) containing such cations will produce a colored aqueous solution. Suitable cations include, but are not limited to cobalt, copper (cuprous and cupric), chrome, nickel, iron (ferric and ferrous), zinc, zinc, manganese, vanadium (vanadyl), palladium and cadmium.
Suitable anions include but are not limited to sulphate, nitrate, fluoride, chloride, bromide, iodide, acetate, tartrate, ammonium tartrate, benzenesulphonate, benzoate, bicarbonate, carbonate, bisulphate, bisulphite, sulphate, sulphite, borate, borotartrate, bromate, butyrate, chlorate, camphorate, chlorite, cinnamate, citrate, disilicate, dithionate, ethylsulphate, ferricyanide, ferrocyanide, fluorosilicate, formate, glycerophosphate, hydrogenphosphate, hydroxostannate, hypochlorite, hyponitrite, hypophosphite, iodate, isobutyrate, lactate, laurate, metaborate, metasilicate, methionate, methylsulphate, nitrite, oleate, orthophosphate, orthophosphite, orthosilicate, oxalate, perborate, perchlorate, phosphate, polyfluoride, polychloride, polyiodide, polybromide, polysulphide, polysulphate, polysulphite, salicylate, silicate, sorbate, stannate, stearate, succinate or valerate, dichromate, chromate, nitrate, throyonate, permanganate, bromide, chloride, fluoride, gluconate, phenolsulfate, selenate.
It has been found, as part of the present invention, that the use of the colored inorganic electrolyte results in formulations which contain a colored electrolyte layer, with the color not leaking into the surfactant layer. Furthermore, it is possible to have stable multi-colored formulations, with the colored inorganic electrolyte in the electrolyte layer, and an organic dye in the surfactant layer.
Suitable electrolytes include but are not limited to the following:
Mixtures of electrolytes may be employed.
Electrolyte may be pre-formed or formed in situ. Electrolytes may be anhydrous or partially or fully hydrated (bound water).
Preferably, the colored inorganic electrolytes suitable for use in the present invention meet both of the following criteria:
(1) they have a high salting out ability;
(2) they are able to lower water activity.
Preferred electrolytes are selected from the group consisting of nickel, cupric and cobaltous salts of sulfate and chloride, because these result in the most pleasing colors for a laundry detergent.
The liquid detergent composition of the invention generally includes from 5 to 50%, more preferably from 10 to 40%, most preferably from 5 to 35% of the colored inorganic electrolyte, in order to attain a stable layered composition, at optimum cost. The concentration of electrolyte to create a two-layered composition depends on the surfactant concentration, the water amount and the identity of the electrolyte. The concentration needed may be predicted by calculating the ionic strength of the electrolyte at a particular concentration. It has been found as part of the present invention that the preferred electrolytes and preferred concentrations are those that have a calculated ionic strength of at least 4.2, preferably at least 4.4, more preferably at least 5.
Ionic strength represents interactions of ions with water molecules and other ions in the solution. Ionic strength may be calculated as follows:
I=xc2xdxcexa3Zi2mj
xcexa3=a sum for i number of ions
I=ionic strength
z=valence factor
m=molal concentration of the ith ion concentration
In the preferred embodiment, in order to control the intensity of the color and to further lower the cost, the colored inorganic electrolyte is employed at lower concentrations, just sufficient to deliver the desired color. Such lower concentrations, however, might not be sufficient to achieve the separation of layersxe2x80x94which function is accomplished by an additional inorganic or organic electrolyte. When mixtures of the colored inorganic electrolyte are employed with additional inorganic or organic electrolytes, the amount of the colored inorganic electrolyte is in the range of from 0.001 to 10%, preferably from 0.01 to 5%, more preferably from 0.05 to 5%, optimally from 0.5 to 3%, while the total amount of all the electrolyte is from 1 to 50%, more preferably from 5 to 40%, most preferably from 5 to 35%, and optimally from 10 to 30%. Again, the ionic strength calculation may be usefully applied to mixtures of electrolytes, to determine the total concentration of the electrolyte necessary to achieve the separation of the layers.
xe2x80x9cOrganic electrolytexe2x80x9d as used herein means an electrolyte containing an organic cation. xe2x80x9cOrganic cation,xe2x80x9d in turn, means a non-metal, positively charged ionic entity. Suitable organic cations include but are not limited to ammonium, ammonium hydroxide, amines, more preferably alkanolamines (e.g., monoethanolamine, diethanolamine, triethanolamine, isopropylamine). Preferred organic electrolytes are selected from the group consisting of monoethanolamine, triethanolamine, and ammonium oxide salts of citrate, carbonate, bicarbonate, borate and sulfate. Monoethanolamine salt is the most effective. Monoethanolamine citrate, monoethanolamine carbonate and monoethanolamine borate are the most preferred, due to their ability to also function as builders and/or buffering agents in the detergent composition. Monoethanolamine citrate is optimum, due to its optimum ability to salt out a surfactant and/or reduce the water activity.
xe2x80x9cAdditional inorganic electrolytexe2x80x9d as used herein means an electrolyte containing an alkali or alkaline earth metal cation. Suitable additional inorganic electrolytes include but are not limited to sodium, potassium, lithium, magnesium, and calcium salts. Preferred electrolytes are selected from the group consisting of sodium and potassium salts of citrate, carbonate, bicarbonate, borate and sulfate. Sodium salt is the most cost-effective. Sodium citrate, sodium carbonate and sodium borate are the most preferred, due to their ability to also function as builders and/or buffering agents in the detergent composition. Sodium citrate is optimum, due to its optimum ability to salt out a surfactant and/or reduce the water activity.
Suitable anions for the additional inorganic electrolyte and the organic electrolyte are selected from the list above.
When the colored inorganic electrolyte is the sole electrolyte employed, it may be necessary to pre-dissolve the electrolyte in heated water or to heat the formulation, in order to attain the layer separation.
Water
The liquid detergent compositions of the invention may (but do not have to) contain significant amounts of water. The inclusion of water is beneficial, in order to incorporate hydrophilic ingredients into the composition. By virtue of employing the inorganic electrolyte as taught herein, the layered composition is attained which may contain high amounts of water, yet the water present in the composition does not dissolve the water-soluble package enveloping the composition.
The liquid detergent composition of the invention generally includes from 1 to 70% of total (free and bound) water, preferably from 5 to 70%, more preferably from 5 to 50%, most preferably from 10 to 50%, and optimally from 25 to 40%, in order to obtain clarity and ease of the dispersion of the composition during use (% by weight of the composition). Yet, by virtue of employing the electrolyte as taught herein the water activity of the inventive compositions is generally low: typically less than 0.94, preferably less than 0.93, more preferably less than 0.9, optimally less than 0.8, in order to obtain compositions which contain optimum amounts of water, yet may be stored safely in a water-soluble package.
Measurement of Water Activity
Water activity (Aw) is the ratio of the vapor pressure of a solution to that of pure water. It is related to the inverse of the relative humidity of the atmosphere above the sample at equilibrium.
Apparatus: Aqualab CX-2 Water Activity meter; Sample containers; Transfer pipets.
Preparation of Salt Standards
1. Salt standards should be prepared in deionized water every six months, or as to needed. They are stored at room temperature, and are used to calibrate the water activity machine with each use.
2. A super-saturated solution must be made of each salt.
3. To prepare a super-saturated solution, keep adding salt crystals to deionized water, shaking well, until there is undissolved salt at the bottom of the jar.
4. Keep the salt solutions at room temperature overnight to reach equilibrium.
5. If salt remains undissolved at the bottom of the jar, a super-saturated solution has been reached. If all of the salt is dissolved, repeat steps 3 and 4.
Aqualab Procedure to Measure Water Activity
1. The Aqualab measures the inverse of the relative humidity of a solution, by evaluating the condensation that forms on a mirror within the machine. Samples containing high levels of propylene glycol are not usually run with the Aqualab because PPG coats the mirror.
2. Turn on the machine so that it can warm up for at least one hour prior to use.
3. Test all samples and standards in duplicate.
4. The Aqualab must be standardized before samples are run. Deionized water should always be evaluated at the beginning of the run. Chose the appropriate salt solutions that are closest to the projected Aw of the test sample, so that the sample""s value is bracketed with standards. After the standards are run, the test samples are evaluated.
5. Use a transfer pipet to add the sample to the sample containers. The containers should only be filled half-way. Load the container in the sleeve of the Aqualab, and push in the sleeve.
6. Turn the Aqualab dial from the upright position (xe2x80x9copen/loadxe2x80x9d) to the left position (xe2x80x9creadxe2x80x9d) to start reading the sample.
7. When the sample is finished (within a few minutes), the machine will beep until the dial is turned back to the upright position. Record the Aw and the temperature.
8. Every 6-8 samples, new standards should be run. In addition, standards should be run after the last sample to ensure that the machine remained calibrated.
Note: the Aqualab variability is +/xe2x88x920.0003 units.
The liquid laundry detergent according to the invention comprises at least two layers. Both layers are preferably isotropic (a single phase when viewed macroscopically), after standing still for at least 24 hours at 20xc2x0 C. xe2x80x9cIsotropicxe2x80x9d is used herein to describe each layer of the inventive composition, since the composition overall contains at least two layers and thus could not be isotropic overall.
Both layers are preferably transparent/translucent. At least one layer (the electrolyte layer) is colored. Generally, the layers are attained when the sufficient amount of the electrolyte is added to the surfactant. The amount differs in each specific case, depending on the identity and the amount of the surfactant(s), water and electrolyte(s). The discussion of ionic strength above is relevant here, since the electrolyte should be present in a sufficient concentration to force surfactant salting out, thus creating layers.
Preferred compositions comprise two layers, with the top layer containing majority, preferably all, of the surfactant, and the bottom layer containing the majority, preferably all, of the electrolyte.
When shaken, the layers within the composition coalesce. Yet, they separate into visible layers, with each layer regaining its clarity, upon standing for at most 24 hours at 20xc2x0 C.
It should be noted that in the final composition, the compositions of the resultant layers do not necessarily correspond with the compositions of the respective layers prior to their being combined into a single composition. This is because of reaction between ingredients, in particular the acidic ingredients and the basic ingredients (e.g., sodium hydroxide) and also, because of possible migration of material between the two layers, or emulsification of some of the layers within each other. Consequently, it is to be understood that the composition of the components as herein described pertains to the compositions prior to their being combined into a single composition. By virtue of employing a surfactant and an electrolyte in the amounts as herein described (and optional ingredients, including those described below), the composition separates into at least two layers, wherein the composition of the layers may differ from the composition of the initial components.
Generally the ranges of the surfactant, electrolyte, and water content within either the respective components or the layers are as follows (% by weight of the relevant component):
The volume ratio of the two components in the final composition is generally in the range of from 10:90 to 90:10, more preferably from 20:80 to 80:20, most preferably from 70:30 to 30:70, and optimally from 40:60 to 60:40, in order to provide the most pleasing appearance and optimum cleaning benefits. The resulting layers have the volume ratios in the same ranges as described above (but the layer ratio may not be the same as the starting component ratio). More than two layers may be present. The additional layer may be a capsule, dispersion or emulsion layer, as described below under Optional Ingredients. Also possible is that a surfactant component may include both highly polar and highly non-polar ingredients, which might separate into more than one organic-rich layer.
Hydrotrope
A particularly preferred optional ingredient is a hydrotrope, which prevents liquid crystal formation. The addition of the hydrotrope thus aids the clarity/transparency of the composition. The hydrotrope is typically included in the surfactant layer. Suitable hydrotropes include but are not limited to propylene glycol, ethanol, urea, salts of benzene sulphonate, toluene sulphonate, xylene sulphonate or cumene sulphonate. Suitable salts include but are not limited to sodium, potassium, ammonium, monoethanolamine, triethanolamine. Preferably, the hydrotrope is selected from the group consisting of propylene glycol, xylene sulfonate, ethanol, and urea to provide optimum performance. The amount of the hydrotrope is generally in the range of from 0 to 30%, preferably from 0.5 to 20%, most preferably from 1 to 15%.
Dye
Another particularly preferred ingredient is a dye, in order to create a composition with at least two visually appealing colored layers. Typically, a dye is an organic molecule and so will partition into the organic (surfactant) layer. It is possible, although less usual that a dye may partition into the electrolyte layer, but the dyes that partition into the surfactant layer are preferred. This is because a dye that partitions into an electrolyte layer will still partially partition (or leak into) the surfactant layer. By virtue of employing a colored inorganic electrolyte in the inventive compositions, a two-colored composition may be attained, with the dye in the surfactant layer.
Suitable dyes include but are not limited to:
Of these, the Azo and Pyrene families of dyes are less preferred, because these dyes will likely partition into both layers (leak). The inventive compositions generally include from 0.0001 to 1%, more preferably from 0.0005 to 0.1%, most preferably from 0.0001 to 0.1% of the dye, in order to provide a pleasing appearance (% by weight of the composition).
Following dyes will most likely partition in the surfactant layer, regardless of the component to which they are added. These dyes have a direct affinity for the surfactant or organic type layer.
Relatively, the following dyes will partition into both layers:
Capsules
The liquid compositions may include encapsulated ingredients, preferably in the form of transparent or colored capsules or an emulsion, or a dispersion. These capsules, emulsion, or dispersion, may be distributed in one or more layers of the inventive compositions, or may be present as an additional layer. Preferred ingredients to be encapsulated are enzymes, bleaches, colorants, perfumes, and mixtures thereof to minimize the damage to these ingredients from water or surfactant, or alkaline ingredients, and/or to enhance the appearance of the product. Preferred inventive compositions comprise from 0.5 to 20%, more preferably from 0.1 to 10%, most preferably from 0.3 to 6%, and optimally from 0.5 to 5%, in order to attain optimum performance and/or appearance (% by weight of the composition).
The preferred laundry composition may further include one or more well-known laundry ingredients, such as builders (from 0.1 to 20%), anti-redeposition agents, fluorescent dyes, perfumes, soil-release polymers, colorant, enzymes, buffering agents, antifoam agents, UV-absorber, etc. Electrolytes may serve as builders in the composition, yet additional builders may be present.
The pH of the inventive compositions is generally in the range of from 2.5 to 12.5, preferably in the range of from 4 to 10, most preferably from 6 to 9, in order to attain optimum laundry cleaning.
Preferably, the detergent composition is a transparent/translucent two-colored composition packaged in the transparent/translucent body.
The packages of the invention may be prepared from polyvinyl alcohol film, or other suitable material, which is filled, then sealed, preferably heat-sealed or water-sealed.
The packages may be filled in any suitable way. Preferably, the liquid detergent composition is pre-mixed (both components) and filled in the same manner as a single phase composition would be. The composition may also be filled component by component.
The package may take many shapes as viewed in a plan view, such as rectangular, square, triangle, round, etc. In one preferred embodiment, the package is in a polyhedral shape (e.g., tetrahedron or a pyramid).
In use, the package is mixed with water (e.g., inside a laundry machine), in order to dissolve the body and to release the contents of the package.

Water-soluble package with multiple distinctly colored layers of liquid laundry detergent

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