BAR COMPOSITIONS WITH ALKYL GLYCERYLETHER SULFONATE SURFACTANT
FIELD This invention relates to a soap-containing laundry detergent bar composition comprising synthetic surfactants and builders. The process to make such composition is also included herein.
BACKGROUND In societies where mechanical washing machines are not common, laundry detergent bars comprising synthetic organic surfactants and detergency builders are used in the laundering of clothes. Technical developments in the field of laundry detergent bars have concerned formulating bars which are effective in cleaning clothes; which have acceptable sudsing characteristics in warm and cool water and in hard and soft water; which have acceptable in-use wear rates, hardness, durability, and feel; which have low smear; and which have a pleasing odor and appearance. Methods for making laundry detergent bars are also well known in the art. Prior art disclosing laundry bars and methods for making laundry bars include: U.S. Pat. 3,178,370, Okenfuss, issued on April 13, 1965; and Philippine Pat. 13,778, Anderson, issued on September 23, 1980.
Soaps are often used in combination with synthetic detergents in such bars.
U.S. Pat. 2,988,511 , Mills, issued on June 13, 1961 , discloses soap/synthetic bars wherein the synthetic detergent is alkyl glyceryiether sulfonate (AGS). The patent teaches that the bars produce high lather and are mild to the skin, and that AGS is an effective dispersant for soap scum.
Philippine Pat. 13788, Anderson, issued on September 23, 1961 , discloses built synthetic detergent laundry bars. The builders are pyrophosphate and carbonate. AGS (identified as "alkyl glyceryl ether sulfate") is disclosed
among the suitable synthetic surfactants for use in the bars. Examples XVII and XXIII contain AGS. Soap is also disclosed as a suitable surfactant but is not shown in combination with AGS. None of the existing art provides all of the advantages and benefits of the present invention. Preparation of alkyl glyceryl ether sulfonates are described in detail in U.S. Pat. 3,024,273, Whyte et al., issued on March 6, 1962.
Because these products are used in intimate contact with skin, there is a continuing need to improve their mildness properties. At the same time, it is necessary to maintain good cleaning performance, good bar physical characteristics (i.e. good bar feel and resistance to wearing away fast in use). Also, because the consumer of this type of product usually associates good cleaning performance with high sudsing, in most instances, it is desirable to maintain high sudsing characteristics when formulating laundry bars.
SUMMARY
The present invention relates to a built laundry detergent bar composition comprising:
(a) from about 20% to about 60% of a C8-C22 soap;
(b) from about 1.75% to about 10% alkyl glyceryiether sulfonate surfactant of the formula
OH
I ROCH2CHCH2SO3M wherein R is a Cβ - C22 alkyl or alkenyl group and M is a salt forming anion; and;
(c) an organic or inorganic detergency builder; wherein the weight ratio of (a) to (b) is from about 4:1 to about 20:1.
These and other features, aspects, and advantages of the present invention will become evident to those skilled in the art from a reading of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION While the specification concludes with claims particularly pointing out and distinctly claiming the invention, it is believed the present invention will be better understood from the following description.
All percentages are by weight of total composition unless specifically stated otherwise. All ratios and proportions herein are by weight, unless otherwise specified. All temperatures are in degrees Celsius (°C) unless otherwise specified. As used herein, "comprising" means that other steps and other ingredients which do not affect the end result can be added. This term encompasses the terms "consisting of and "consisting essentially of. All cited references are incorporated herein by reference in their entireties. Citation of any reference is not an admission regarding any determination as to its availability as prior art to the claimed invention. As used herein, the term "alkyl" means a hydrocarbyl moiety which is straight or branched, saturated or unsaturated (Included in the term "alkyl" is the alkyl portion of acyl groups.). Unless otherwise specified, alkyl are preferably saturated or unsaturated with double bonds, preferably with one or two double bonds. The term "tallow" is used herein in connection with materials with fatty acid mixtures which typically are linear and have an approximate carbon chain length distribution of 2% C-|4, 29% Cie. 23% C<|8- 2% palmitoleic, 41% oleic, and 3% linoleic (the first three fatty acids listed are saturated). Other mixtures with similar distribution, such as those derived from various animal tallow and lard, are also included within the term tallow. The tallow can also be hardened (i.e., hydrogenated) to convert part or all of the unsaturated fatty acid moieties to saturated fatty acid moieties.
The term "coconut oil" is used herein in connection with materials with fatty acid mixtures which typically are linear and have an approximate carbon chain length distribution of about 8% Cβ, 7% C<ιo, 48% Cη2, 17% C14, 9% C-|6-
2% C18. 7% oleic. and 2% linoleic (the first six fatty acids listed being saturated).
Other sources having similar carbon chain length distribution in their fatty acids, such as palm kernel oil, and babassu oil, are included within the term coconut oil.
In accordance with the present invention, it has been found that built laundry bars with excellent mildness to skin, cleaning performance, sudsing and physical characteristics can be achieved by using a surfactant system comprising alkyl glyceryiether sulfonate and soap. Alkyl Glyceryiether Sulfonate
The compositions of the present invention include alkyl glyceryiether sulfonate. Alkyl glyceryiether sulfonate (AGS) surfactant employed in the
compositions of this invention can be prepared by reacting fatty alcohols with a slight excess of epichlorohydrin and then sulfonating the resulting chloroglyceryl ether by using a Streckerization reaction with a sulfite salt (e.g. sodium sulfite). The resulting product is a mixture in which the primary component is alkyl glyceryiether sulfonate having the formula:
OH
I ROCH2CHCH2SO3M wherein R is Cø - C22 (preferably C12-C18) alkyl or alkenyl, and M is a water- solubilizing, salt-forming cation such as alkali metal (e.g. sodium or potassium), ammonium, or mono-, di-, or tri- C^ - C3 alkylammonium or C-| - C3 mono-, di-, or tri- hydroxyalkylammonium. Minor amounts of the corresponding diglycerylether disulfonate and triglyceryl trisulfonate salts and some isomers may also be present. Preparation of AGS is described in detail in U.S. Pat. 3, 024,273, Whyte et al, issued on March 6, 1962.
AGS can also be produced as an aqueous paste, which can then be converted to a dried flake form for ease of handling. Typical moisture for the AGS flake is 2-3%.
AGS comprises from about 1.75% to about 10%, preferably from about 2.5% to about 8.5% of the final bar composition. Soap
The compositions of the present invention include soap. As used herein, "soap" means salts of fatty acids. The fatty acids are linear or branched containing from about 8 to about 24 carbon atoms, preferably from about 10 to about 20 carbon atoms. The average carbon chain length for the fatty acid soaps is from about 12 to about 18 carbon atoms, preferably from about 14 to about 16 carbon atoms. Preferred salts of the fatty acids are alkali metal salts, such as sodium and potassium, especially sodium. Also preferred salts are ammonium and alkylolammonium salts. The fatty acids of soaps useful in the subject invention bars are preferably obtained from natural sources such as plant or animal esters; examples include coconut oil, palm oil, palm kernel oil, olive oil, peanut oil, corn oil, sesame oil, rice bran oil, cottonseed oil, babassu oil, soybean oil, castor oil, tallow, whale oil, fish oil, grease, lard, and mixtures thereof. Preferred fatty acids are obtained from coconut oil, tallow, palm oil (palm stearin oil), palm kernel oil, and mixtures
thereof. Fatty acids can be synthetically prepared, for example, by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the Fischer-Tropsch process.
Alkali metal soaps can be made by direct saponification of the fats and oils or by the neutralization of the free fatty acids which are prepared in a separate manufacturing process. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium and potassium tallow and coconut soaps.
Preferred soap raw materials for the subject invention bars are soaps made from mixtures of fatty acids from tallow and coconut oil. Typical mixtures have tallowxoconut fatty acid ratios of 85:15, 80:20, 75:25, 70:30, and 50:50; preferred ratios are about 80:20 to 65:35.
Preferred soap raw materials for the subject invention are neat soaps made by kettle (batch) or continuous saponification. Neat soaps typically comprise from about 65% to about 75%, preferably from about 67% to about 72%, alkali metal soap; from about 24% to about 34%, preferably from about 27% to about 32%, water; and minor amounts, preferably less than about 1% total, of residual materials and impurities, such as alkali metal chlorides, alkali metal hydroxides, alkali metal carbonates, glycerin, and free fatty acids. Another preferred soap raw material is soap noodles or flakes, which are typically neat soap which has been dried to a water content of from about 10% to about 20%. The other components above are proportionally concentrated.
Soaps are present in the compositions herein at levels of from about 20% to about 60%, preferably from about 28% to about 47.5%. The ratio of soap to AGS in the compositions herein is from about 4:1 to about 20:1 , preferably from about 4:1 to about 15:1 , most preferably from about 4:1 to about 10:1. Builders
The compositions of the present invention include builders. The laundry bars of the invention contains from 1% to about 60%, preferably from about 5% to about 25% organic or inorganic detergent builder. Because of the efficiency of AGS in dispersing soap curd, the amount of builder in formulating bars of the present invention for use in water of a given hardness can be less than when other anionic synthetic detergents are formulated with soap in laundry bars.
Builders are generally selected from the various water-soluble, alkali metal, ammonium or substituted ammonium phosphates, polyphosphates, phosphonates, polyphosphonates, carbonates, silicates, borates, polyhydroxy sulfonates, polyacetates, carboxylates, and polycarboxylates. Preferred are the alkali metal, especially sodium, salts of the above.
Specific examples of inorganic phosphate builders are sodium and potassium tripolyphosphate, pyrophosphate, polymeric metaphosphate having a degree of polymerization of from about 6 to 21 , and orthophosphates. Examples of polyphosphonate builders are the sodium and potassium salts of ethylene diphosphonic acid, the sodium and potassium salts of ethane 1-hydroxy-1 , 1- diphosphonic acid and the sodium and potassium salts of ethane, 1 ,1 ,2- triphosphonic acid. Other phosphorous builder compounds are disclosed in U.S. Patents 3,159,581 ; 3,213,030; 3,422,021 ; 3,422,021 ; 3,422,137; 3,400,176 and 3,400,148, all of which are incorporated herein by reference. Examples of nonphosphorus, inorganic builders which can be used herein are sodium and potassium carbonate, bicarbonate, sesquicarbonate, tetraborate decahydrate, and silicates having a weight ratio of Siθ2 to alkali metal oxide of from about 0.5 to about 4.0, preferably from about 1.0 to about 2.4. Water- soluble, nonphosphorus organic builders useful herein include the various alkali metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates and polyhydroxy sulfonates. Examples of polyacetate and polycarboxylate builders are the sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylene diamine tetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, and citric acid.
Polymeric polycarboxylate builders are set forth in U.S. Patent 3, 308,067, Diehl, issued on March 7, 1967, the disclosure of which is incorporated herein by reference. Such materials include the water soluble salts of homo- and copolymers of aliphatic carboxylic acids such as maleic acid, itaconic acid, mesaconic acid, fumaric acid, aconitic acid, citraconic acid and methylenemalonic acid.
Other suitable polycarboxylates for use herein are the polyactetal carboxylates described in U.S. Patent 4,144,226, issued on March 13, 1979 to Crutchfield et al., and U.S. Patent 4,246,495, issued on March 27, 1979 to Crutchfield et al., both of which are incorporated herein by reference. These
polyacetal carboxylates can be prepared by bringing together under polymerization conditions an ester of glyoxylic acid and a polymerization initiator. The resulting polyacetal carboxylate ester is then attached to chemically stable end groups to stabilize the polyacetal carboxylate against rapid depolymerization in alkaline solution, converted to the corresponding salt, and added to a detergent composition. Particularly preferred polycarboxylate builders are the ether carboxylate builder compositions comprising a combination of tartrate monosuccinate and tartrate disuccinate described in U.S. Patent 4,633,071 , Bush et al., issued on May 5, 1987, the disclosure of which is incorporated herein by reference.
Water-soluble silicate solids represented by the formula Siθ2#M2θ, M being an alkali metal, and having a Siθ2*M2θ weight ratio of from about 0.5 to about 4.0, are useful salts in the detergent granules of the invention at levels of from about 2% to about 15% of an anhydrous weight basis, preferably from about 3% to about 8%. Anhydrous or hydrated particulate silicate can be utilized as well.
Preferred builders for use herein are the sodium and potassium salts of tripolyphosphate, pyrophosphate and carbonate. Additional Components In addition to the AGS and soap, the compositions of the present invention further include other surfactants.
Synthetic anionic surfactants which are suitable for use herein include the water-soluble salts, preferably the alkali metal, ammonium and alkylolammonium salts of organic sulfuric reaction products having in their molecular structure an alkyl group containing from about 10 to about 20 carbon atoms and a sulfonic acid or sulfuric acid ester group. Examples of this group of synthetic surfactants are the sodium and potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (Cs-18 carbon atoms) such as those produced by reducing the glycerides of tallow or coconut oil; and the sodium and potassium alkyl benzene sulfonates in which the alkyl group contains from about 9 to about 15 carbon atoms, in straight chain or branched chain configuration, e.g., those of the type described in U.S. Patents 2,220,099 and 2,477,383. Especially valuable are linear straight chain alkyl benzene sulfonates in which the average number of carbon atoms in the alkyl group is from about 11 to 13, abbreviated as
Cl 1-13 LAS. The alkali metal salts, particularly the sodium salts of these surfactants are preferred.
Other suitable surfactants for use herein are sodium or potassium salts of alkyl ethoxy ether sulfates (AES) having the following formula: RO(C2H4θ)xSθ3M
In the above structure R is alkyl of from about 10 to about 20 carbon atoms. On average, R is from about 13 to about 16. R is preferably saturated and linear. In the above structure, x is an integer from 1 to about 20 and M is a water-soluble cation, for example, an alkali metal cation (e.g., sodium, potassium, lithium), preferably sodium.
The preferred AES surfactant has a saturated linear alkyl with an average of 14 to 15 carbon atoms, an average of about one ethoxy unit per molecule, and is a sodium salt (Ci4-i5AE-|Sθ3Na).
In addition, suitable synthetic anionic surfactants include the water-soluble salts of esters of alpha-sulfonated fatty acids containing from about 6 to 20 carbon atoms in the fatty acid group and from about 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxyalkane-1 -sulfonic acids containing from about 2 to 9 carbon atoms in the acyl group and from about 9 to about 23 carbon atoms in the alkane moiety; water-soluble salts of olefin and paraffin sulfonates containing from about 12 to 20 carbon atoms; and beta-alkyloxy alkane sulfonates containing from about 1 to 3 carbon atoms in the alkyloxy group and from about 8 to 20 carbon atoms in the alkane moiety.
Preferred synthetic anionic surfactants, if included, are C-|rj-18 linear alkyl benzene sulfonates, CiO-14 alkyl glyceryl ether sulfonates, C10-I8 a'M sulfates, and mixtures thereof. The amount of synthetic anionic surfactant in the composition herein is from about 0.5% to about 11%, preferably from about 1% to about 10%, most preferably from about 1.5% to about 7%.
The detergent bars of the present invention can contain other optional surfactants other than anionic surfactants, which are commonly used in detergent products.
Useful other optional surfactants can be nonionic, and can include: Alkyl polysaccharides, alkyl polyglucosides, such as described in U.S. Patent 4,565,647, Llenado; Polyhydroxy fatty acid amides, of the formula R-C(O)- N(R')-Z, wherein R is C5-C31 hydrocarbyl, preferably C11-C17 alkyl or alkenyl, R' is H, C1-C4 hydrocarbyl, 2-hydroxyethyl, 2-hydroxypropyl, or a mixture
thereof, preferably methyl, and Z is polyhydroxy(linear)hydrocarbyl chain having at least 3 hydroxyls directly connected to the chain, preferably -CH2- (CHOH)4-CH2OH, such as described in EP 550,652; Semi-polar nonionic surfactants, such as water-soluble amine oxide, water-soluble phosphine oxide, and water-soluble sulfoxide surfactants; and Water-soluble nonionic synthetic surfactants broadly defined as compounds produced by the condensation of ethylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. The length of the polyoxyethylene group which is condensed with any particular hydrophobic group can be readily adjusted to yield water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.
Cationic surfactants can also be used in the detergent compositions herein and suitable quaternary ammonium surfactants are selected from mono C6-C16, preferably C6-C10 N-alkyl or alkenyl ammonium surfactants wherein remaining N positions are substituted by methyl, hydroxyethyl or hydroxypropyl groups.
Ampholytic surfactants can also be used in the detergent compositions herein, which include aliphatic derivatives of heterocyclic secondary and tertiary amines; zwitterionic surfactants which include derivatives of aliphatic quaternary ammonium, phosphonium and sulfonium compounds; water-soluble salts of esters of alpha-sulfonated fatty acids; betaines having the formula R(R1)2N+R2COO-, wherein R is a C6-C 8 hydrocarbyl group, preferably a 10-C16 alkyl group or C10-C16 acylamido alkyl group, each R1 is typically C1-C3 alkyl, preferably methyl and R2 is a C1-C5 hydrocarbyl group, preferably a C1-C3 alkylene group, more preferably a C1-C2 alkylene group. Examples of suitable betaines include coconut acylamidopropyldimethyl betaine; hexadecyl dimethyl betaine; C 2-14 acylamidopropylbetaine; C8-14 acylamidohexyldiethyl betaine; 4[C 4-16 acyimethylamidodiethylammonio]-1- carboxybutane; C16-I8 acylamidodimethylbetaine; C 12-16 acylamidopentanediethylbetaine; and
[C12-16 acylmethylamidodimethylbetaine. Preferred betaines are C12-I8 dimethyl-ammonio hexanoate and the C10-I8 acylamidopropane (or ethane) dimethyl (or diethyl) betaines; and the sultaines having the formula (R(R1 )2N+R2SO3- wherein R is a C6-C18 hydrocarbyl group, preferably a
C10-C16 alkyl group, more preferably a C12-C13 alkyl group, each R1 is typically C1-C3 alkyl, preferably methyl, and R2 is a C1-C6 hydrocarbyl group, preferably a C1-C3 alkylene or, preferably, hydroxyalkylene group. Examples of suitable sultaines include C12-C14 dimethylammonio-2-hydroxypropyl sulfonate, C12-C14 amido propyl ammonio-2-hydroxypropyl sultaine, C12-C14 dihydroxyethylammonio propane sulfonate, and C16-I8 dimethylammonio hexane sulfonate, with C 12-14 amido propyl ammonio-2-hydroxypropyl sultaine being preferred.
In addition, a hydrotrope, or mixture of hydrotropes, can be optionally present in the laundry detergent bar. Preferred hydrotropes include the alkali metal, preferably sodium, salts of toluene sulfonate, xylene sulfonate, cumene sulfonate, sulfosuccinate, and mixtures thereof. Preferably, the hydrotrope is added to the linear alkyl benzene sulfonic acid prior to its neutralization. The hydrotrope, if present, will preferably be present at from about 0.5% to about 5% of the laundry detergent bar.
The fabric softening clay that can optionally be used in the present composition is preferably a smectite-type clay. The smectite-type clays can be described as expandable, three-layer clays; i.e., alumino-silicates and magnesium silicates, having an ion exchange capacity of at least about 50 meq/100 g. of clay. Preferably the clay particles are of a size that they can not be perceived tactilely, so as not to have a gritty feel on the treated fabric of the clothes. The fabric softening clay can be added to the bar to provide about 1% to about 30% by weight of the bar, more preferably from about 5% to about 20%, and most preferably about 8% to 14%. While any of the smectite-type clays described herein are useful in the present invention, certain clays are preferred. For example, Gelwhite GP is an extremely white form of smectite-type clay and is therefore preferred when formulating white granular detergent compositions. Volclay BC, which is a smectite-type clay mineral containing at least 3% iron (expressed as Fe2θ3) in the crystal lattice, and which has a very high ion exchange capacity, is one of the most efficient and effective clays for use in the instant compositions from the standpoint of product performance. On the other hand, certain smectite-type clays are sufficiently contaminated by other silicate minerals that their ion exchange capacities fall below the requisite range; such clays are of no use in the instant compositions.
It has been found that the use of a clay flocculating agent in a laundry bar containing softening clay provides surprisingly improved softening clay deposition onto the clothes and clothes softening performance, compared to that of laundry bars comprising softening clay alone. The polymeric clay flocculating agent that can be optionally present in the composition, is selected to provide improved deposition of the fabric softening clay. Typically such materials have a high molecular weight, greater than about 100,000. Examples of such materials can include long chain polymers and copolymers derived from monomers such as ethylene oxide, acrylamide, acrylic acid, dimethylamino ethyl methacrylate, vinyl alcohol, vinyl pyrrolidone, and ethylene imine. Gums, like guar gums, are suitable as well. The preferred clay flocculating agent is a poly(ethylene oxide) polymer.
A particularly preferred optional component of the present invention is a detergent chelant. Such chelants are able to sequester and chelate alkali cations (such as sodium, lithium and potassium), alkali metal earth cations (such as magnesium and calcium), and most importantly, heavy metal cations such as iron, manganese, zinc and aluminum. Preferred cations include sodium, magnesium, zinc, and mixtures thereof. The detergent chelant is particularly beneficial for maintaining good cleaning performance and improved surfactant mileage, despite the presence of the softening clay and the clay flocculating agent.
The detergent chelant is preferably a phosphonate chelant, particularly one selected from the group consisting of diethylenetriamine penta(methylene phosphonic acid), ethylene diamine tetra(methylene phosphonic acid), and mixtures and salts and complexes thereof, and an acetate chelant, particularly one selected from the group consisting of diethylenetriamine penta(acetic acid), ethylene diamine tetra(acetic acid), and mixtures and salts and complexes thereof. Particularly preferred are sodium, zinc, magnesium, and aluminum salts and complexes of diethylenetriamine penta(methylene phosphonate) diethylenetriamine penta (acetate), and mixtures thereof.
Preferably such salts or complexes have a molar ratio of metal ion to chelant molecule of at least 1 :1 , preferably at least 2:1.
The detergent chelant can be included in the laundry bar at a level up to about 5%, preferably from about 0.1 % to about 3%, more preferably from about 0.2% to about 2%, most preferably from about 0.5% to about 1.0%. Such
detergent chelant component can be used beneficially to improve the surfactant mileage of the present laundry bar, meaning that for a given level of anionic surfactant and level of detergent chelant, equivalent sudsing and cleaning performance can be achieved compared to a similar bar containing a higher level of the anionic surfactant but without the detergent chelant.
Another preferred additional component of the laundry bar is fatty alcohol having an alkyl chain of 8 to 22 carbon atoms, more preferably from 12 to 18 carbon atoms. Fatty alcohol is effective at reducing the bar wear rate and smear (mushiness) of laundry bars. A preferred fatty alcohol has an alkyl chain predominantly containing from 16 to 18 carbon atoms, so-called "high-cut fatty alcohol," which can exhibit less base odor of fatty alcohol relative to broad cut fatty alcohols. Typically fatty alcohol is contained in the laundry bar at up to a level of 10%, more preferably from about 0.75% to about 6%, most preferably from about 2% to about 5%. The fatty alcohol is generally added to a laundry bar as free fatty alcohol. However, low levels of fatty alcohol can be introduced into the bars as impurities or as unreacted starting material. For example, laundry bars based on coconut fatty alkyl sulfate can contain, as unreacted starting material, from 0.1% to 3.5%, more typically from 2% to 3%, by weight of free coconut fatty alcohol on a coconut fatty alkyl sulfate basis. Another preferred optional component in the laundry bar is a dye transfer inhibiting (DTI) ingredient to prevent diminishing of color fidelity and intensity in fabrics. A preferred DTI ingredient can include polymeric DTI materials capable of binding fugitive dyes to prevent them from depositing on the fabrics, and decolorization DTI materials capable of decolorizing the fugitives dye by oxidation. An example of a decolorization DTI is hydrogen peroxide or a source of hydrogen peroxide, such as percarbonate or perborate. Non-limiting examples of polymeric DTI materials include polyvinylpyrridine N-oxide, polyvinylpyrrolidone (PVP), PVP-polyvinylimidazole copolymer, and mixtures thereof. Copolymers of N-vinylpyrrolidone and N-vinylimidazole polymers (referred to as "PVPI") are also preferred for use herein.
Another preferred optional component in the laundry bar is a secondary fabric softener component in addition to the softening clay. Such materials can be used at levels of about 0.1% to 5%, more preferably from 0.3% to 3%, and can include: amines of the formula R4R5R6N, wherein R4 is C5 to C22 hydrocarbyl, R5 and RQ are independently C1 to C10 hydrocarbyl. One
preferred amine is ditallowmethyl amine; complexes of such amines with fatty acid of the formula R7COOH, wherein R7 is Cg to C22 hydrocarbyl, as disclosed in EP No. 0,133,804; complexes of such amines with phosphate esters of the formula R8θ-P(O)(OH)-ORg and HO-P(O)(OH)-OR9, wherein Rs and Rg are independently C1 to C20 alkyl of alkyl ethoxylate of the formula -alkyl- (OCH2CH2); cyclic amines such as imidazolines of the general formula 1 -(higher alkyl) amido (lower alkyl)-2-(higher alkyl)imidazoline, where higher alkyl is from 12 to 22 carbons and lower alkyl is from 1 to 4 carbons, such as described in UK Patent Application GB 2,173,827; and quaternary ammonium compounds of the formula R10R11 12R13N+X~, wherein R10 is alkyl having 8 to 20 carbons, R11 is alkyl having 1 to 10 carbons, R12 and R13 are alkyl having 1 to 4 carbons, preferably methyl, and X is an anion, preferably Cl" or Br, such as C-|2-13 alkyl trimethyl ammonium chloride.
Yet another optional component in the laundry bar is a bleach component. The bleaching component can be a source of _OOH group, such as sodium perborate monohydrate, sodium perborate tetrahydrate and sodium percarbonate. Sodium percarbonate (2Na2CO3-3H2O2) is preferred since it has a dual function of both a source of HOOH and a source of sodium carbonate. Another optional bleaching component is a peracid p_er se, such as a formula: CH3(CH2)w-NH-C(O)-(CH2)zCO3H wherein z is from 2 to 4 and w is from 4 to 10. The bleaching component can contain, as a bleaching component stabilizer, a chelating agent of polyaminocarboxylic acids, polyaminocarboxylates such as ethylenediaminotetraacetic acid, diethylenetriaminopentaacetic acid, and ethylenediaminodisuccinic acid, and their salts with water-soluble alkali metals. The bleach components can be added to the bar at a level up to 20%, preferably from about 1% to about 10%, more preferably from about 2% to about 6%.
Sodium sulfate is a well-known filler that is compatible with the compositions of this invention. It can be a by-product of the surfactant sulfation and sulfonation processes, or it can be added separately. Other filler materials include bentonite and talc.
Calcium carbonate (also known as Calcarb) is also a well known and often used component of laundry bars. Such materials are typically used at levels up to 40%, preferably from about 5% to about 25%.
Binding agents for holding the bar together in a cohesive, soluble form can also be used, and include natural and synthetic starches, gums, thickeners, and mixtures thereof.
Soil suspending agents can be used. In the present invention, their use is balanced with the fabric softening clay/clay flocculating agent combination to provide optimum cleaning and fabric softening performance. Soil suspending agents can also include water-soluble salts of carboxymethylcellulose and carboxyhydroxymethylcellulose. A preferred soil suspending agent is an acrylic/maleic copolymer, commercially available as Sokolan, from BASF Corp. Other soil suspending agents include polyethylene glycols having a molecular weight of about 400 to 10,000, and ethoxylated mono- and polyamines, and quaternary salts thereof.
Optical brighteners are also preferred optional ingredients in laundry bars of the present invention. Preferred optical brighteners are diamino stilbene, distyrilbiphenyl-type optical brighteners. Preferred as examples of such brighteners are 4,4'-bis{[4-aniiino-6-bis(2-hydoxyethyl) amino-1 ,3,5-trizin-2- yl]amino}stilbene-2,2'-disulfonic acid disodium salt, 4-4'-bis(2-sulfostyryl) biphenyl and 4,4'-bis[(4-anilino-6-morpholino-1 ,3,5-triazin-2-yl) aminojstilbene- 2,2'-disulfonic acid disodium salt. Such optical brighteners, or mixtures thereof, can be used at levels in the bar of from about 0.05% - 1.0%.
Dyes, pigments, germicides, and perfumes can also be added to the bar composition Processing
The detergent laundry bars of the present invention can be processed in conventional soap or detergent bar making equipment with some or all of the following key equipment: blender/mixer, mill or refining plodder, two- stage vacuum plodder, logo printer/cutter, cooling tunnel and wrapper.
In a typical process the raw materials, including the AGS, are mixed in the blender. The mixing can take from one minute to one hour, with the usual mixing time being from about two to twenty minutes. The blender mix is charged to a surge tank. The product is conveyed from the surge tank to the mill or refining plodder via a multi-worm conveyer.
After milling or preliminary plodding, the product is then conveyed to a double vacuum plodder, operating at high vacuum, e.g. 600 to 740 mm of mercury vacuum, so that entrapped air is removed. The product is extruded and
cut to the desired bar length, and printed with the product brand name. The printed bar can be cooled, for example in a cooling tunnel, before it is wrapped, cased, and sent to storage.
The following examples further describe and demonstrate the preferred embodiments within the scope of the present invention. The examples are given solely for the purpose of illustration, and are not to be construed as limitations of the present invention since many variations thereof are possible without departing from its spirit and scope.
BAR EXAMPLES
The invention will be illustrated by the following examples. The compositions are expressed as "parts per 100 parts of laundry bar":