WO1998016611A1

WO1998016611A1 - Laundry bar compositions comprising dihydric alcohol

Info

Publication number: WO1998016611A1
Application number: PCT/US1996/016238
Authority: WO
Inventors: Kennie Uy Dee; Gerard Abellera Latoga
Original assignee: The Procter & Gamble Company
Priority date: 1996-10-11
Filing date: 1996-10-11
Publication date: 1998-04-23
Also published as: AU7263896A; JPH10512921A

Abstract

The present invention is directed to a synthetic laundry bar composition comprising synthetic surfactant, wherein at least 20 % of the total surfactant is alkyl sulfate. The composition delivers significant improvement in the physical properties of the bar by minimizing bar brittleness, with the addition of low levels of dihydric alcohol, especially propylene glycol.

Description

LAUNDRY BAR COMPOSITIONS COMPRISING DIHYRDRIC ALCOHOL

FIELD OF THE INVENTION The present invention relates to synthetic laundry bar compositions having improved physical properties.

BACKGROUND OF THE INVENTION 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. Synthetic laundry bars typically comprise a synthetic anionic surfactant such as the alkali metal salt of an alkyl benzene sulfonic acid or alkali metal salt of an alkyl sulfate and one or more alkaline builders such as alkali metal polyphosphates, carbonates or silicates. 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 April 13, 1995; and Philippine Pat. 13,778, Anderson, issued September 23, 1980.

One common problem with a bar's physical property is brittleness. Without being limited by theory, it is believed that the addition of certain surfactants, especially alkyl sulfate. causes brittleness. Furthermore, the addition of bleach is thought to cause brittleness. When bars are too brittle, the bars break and/or crumble, especially when the bars are being transported from one location to another. The broken bars are undesirable to consumers and leads to waste of the product. Aesthetically, consumers prefer to purchase bars that are not broken. In addition, it is not preferable to have bars break into pieces while a consumer is handling the bar. It has now been found that a synthetic laundry bar composition comprising synthetic surfactant and no more than about 10% soap delivers significant improvement in the physical properties of the bar by minimizing bar brittleness, with the addition of low levels of dihydric alcohol, especially propylene glycol.

SUMMARY OF THE INVENTION The present invention is directed to a synthetic laundry detergent bar composition comprising:

A. from about 10% to about 40% synthetic anionic surfactant, wherein at least 20% of the total surfactant component is alkyl sulfate;

B. no more than about 10% soap;

C. from about 5% to about 50% detergent builder; and C. from about 0.05% to about 2% dihydric alcohol.

Such a detergent composition satisfies the need for a laundry bar composition with improved physical properties by minimizing bar brittleness.

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 with the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention it has been found that synthetic laundry bars have good physical properties with an effective amount of dihydric alcohol.

All percentages, ratios and proportions herein are by weight, unless otherwise specified. All temperatures are in degrees Celsius (°C) unless otherwise specified. All documents cited are in relevant part, incorporated herein by reference.

As used herein, the term "alkyl" means a hydrocarbyl moiety which is straight or branched, saturated or unsaturated. 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% C14, 29% Ci6, 23% C\$, 2% palmitoleic, 41% oleic, and 3% linoleic (the first three fatty acids listed are saturated). Other mixtures with similar distribution, such as those from palm oil and 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% Cg, 7% C₁₀, 48% Cj2, 17% C14, 9% C₁₆, 2% C_{1 8}, 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. Synthetic Anionic 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. (Included in the term "alkyl" is the alkyl portion of acyl groups.) Examples of this group of synthetic surfactants are the sodium and potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (Cg-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 C\ ι_ι 3 LAS. The alkali metal salts, particularly the sodium salts of these surfactants are preferred. Alkyl benzene sulfonates and processes for making them are disclosed in U.S. Patent Nos. 2,220,099 and 2,477,383.

Other synthetic anionic surfactants suitable for use herein are the sodium alkyl glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates.

Preparation of alkyl glyceryl ether sulfonates are described in detail in U.S. Pat.

3,024,273, Whyte et al., issued March 6, 1962.

Another suitable surfactant 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 0.5 to about 20 and M is a water- soluble cation, for example, an alkali metal cation (e.g., sodium, potassium, lithium), preferably sodium or potassium, especially sodium.

The preferred AES surfactant has a saturated linear alkyl with an average of 14 to 15 carbon atoms, a range of from about 14 to about 15 carbon atoms, an average of about one ethoxy unit per molecule, and is a sodium salt (Ci4_i 5AEι S03Na).

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 alkyl group and from about 8 to 20 carbon atoms in the alkane moiety. Preferred synthetic anionic surfactants are C I Q-18 linear alkyl benzene sulfonates,

C 10- 14 alkyl glyceryl ether sulfonates, and Ci Q-18 ^a^yl sulfates. The amount of synthetic anionic surfactant in the composition herein is from about 10% to about 40%, preferably from about 15% to about 30%. Of the total surfactant component, bars of this invention have at least about 20% alkyl sulfate, preferably at least about 40% alkyl sulfate, most preferably at least about 50% alkyl sulfate. Builders

The laundry bars of the invention contains from about 5% to about 50%, preferably from about 10% to about 30% detergent builder. These detergent builders can be, for example, water-soluble alkali-metal salts of phosphate, pyrophosphates, orthophosphates, tripolyphosphates, higher polyphosphates, and mixtures thereof. Preferred builders are a water-soluble alkali-metal salt of tripolyphosphate, and a mixture of tripolyphosphate and pyrophosphate. The builder can also be a non-phosphate detergent builder. Specific examples of non-phosphate, inorganic detergency builders include water-soluble inorganic carbonate and bicarbonate salts. The alkali metal (e.g., sodium and potassium) carbonates, bicarbonates, and silicates are particularly useful herein. Specific preferred examples of builders include sodium tripolyphosphates (STPP) and tetra sodium pyrophosphates (TSPP), and mixtures thereof. Other specifically preferred examples of builders include zeolites and polycarboxylates.

Sodium carbonate is a particularly preferred ingredient in the subject invention compositions, since in addition to its use as a builder, it can also provide alkalinity to the composition for improved detergency, and also can serve as a neutralizing agent for acidic components added in the composition processing. Sodium carbonate is particularly preferred as a neutralizing inorganic salt for an acid precursor of an anionic surfactant used in such compositions, such as the alkyl ether sulfuric acid and alkyl benzene sulfonic acid.

Co-polymers of acrylic acid and maleic acid are preferred in the subject compositions as auxiliary builders, since it has been observed that their use in combination with fabric softening clay and clay flocculating agents further stabilizes and improves the clay deposition and fabric softening performance. Dihydric Alcohol

The dihydric alcohol to be used in the present invention contain two hydroxyl groups connected to different carbon atoms. The preferred dihydric alcohol has two to six carbon atoms. Examples of useful dihydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, butylene glycol (2,3- dihydroxy butane), pentamethylene glycol (1,5- pentanediol), hexylene glycol and dipropylene glycol.

Propylene glycol is preferred, especially, 1 ,2- propylene glycol (diethylene glycol) and 1,3- propylene glycol (triethylene glycol).

The amount of dihydric alcohol in the present bar composition is from about 0.05% to about 2%, more preferably from about 0.1% to about 0.5%, and most preferably from about 0.2% to about 0.25%. Soap

In addition to the synthetic anionic surfactant, soap may optionally be added as a co-surfactant.

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 optionally present in the compositions herein at levels of no more than about 10%), by weight of the composition. If included, a preferred level of soap is from about 1% to about 8%, more preferably 2% to about 6%.

Adjunct Ingredients

Bleach

A preferred optional component in the laundry bar is an oxygen bleach component. The oxygen bleaching component can be a source of "OOH group, such as sodium perborate monohydrate, sodium perborate tetrahydrate and sodium percarbonate. Sodium percarbonate (2Na2Cθ3-3H2θ2) 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 per se, such as a formula:

CH3(CH2)w-NH-C(0)-(CH₂)zC03H 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, if any, can be added to the bar, if any, at a level up to 20%, preferably from about 1% to about 10%, more preferably from about 2% to about 6%.

When oxygen bleach is used, it is preferred that the dihydric alcohol be one wherein the two hydroxyl groups are separated by at least one carbon atom. Soil Suspending Agents

Soil suspending agents can be optionally 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. One such 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. A highly preferred soil suspending agent is a water-soluble salt of carboxymethylcellulose and carboxyhydroxymethylcellulose. Soil suspending agents should be used at levels up to about 5%, preferably about 0.1-1%). Other Optional Surfactants

The detergent bars of the present invention can contain other optional ingredients commonly used in detergent products. A typical listing of the classes and species of optional surfactants, (e.g. nonionic, zwitterionic and amphoteric surfactants) optional alkaline builders such as sodium carbonate trisodium phosphate sodium silicate, etc. and other ingredients useful herein appears in U.S. Pat. No. 3,664,961, issued to Norris on May 23, 1972, and EP 550,652, published on April 16, 1992. Such optional surfactants, if present, can be included at levels up to a total of about 10%), preferably about 0.5-3%.

In addition, a hydrotrope, or mixture of hydrotropes, can be 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. Moisture

The compositions of the subject invention comprise from about 1% to about 20% moisture, preferably from about 2% to about 10% moisture, more preferably from about 2% to about 5% moisture, of the final bar composition. Fabric Softening Clay

The fabric softening clay 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 50% by weight of the bar, more preferably from about 2% to about 20%, and most preferably about 3% 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. Clay Flocculating Agent 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 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. The amount of clay flocculating agent, if any, is about 0.2-2%, preferably about 0.5-1%.

Other Optional Adjunct Ingredients

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(mefhylene 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%.

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. 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, if any, is present 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. The amount of DTI included in the subject compositions, if any, is about 0.05-5%, preferably about 0.2-2%.

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, if any, 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 R are independently Ci to C J O hydrocarbyl. One preferred amine is ditallowmethyl amine; complexes of such amines with fatty acid of the formula R7COOH, wherein R7 is C9 to C22 hydrocarbyl, as disclosed in EP No. 0,133,804; complexes of such amines with phosphate esters of the formula R80-P(0)(OH)-ORQ and HO-P(0)(OH)-OR9, wherein R8 and R9 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 Rl O l lRl2 l3N⁺X", wherein Rio is alkyl having 8 to 20 carbons, Ri 1 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 12- 13 alkyl trimethyl ammonium chloride.

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 filler component of laundry bars. Fillers include minerals, such as talc and hydrated magnesium silicate-containing minerals, where the silicate is mixed with other minerals, e.g., old mother rocks such as dolomite. Filler materials are typically used, if included, 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. Such materials, if included, are typically at levels up to about 3%, preferably about 0.5-2%. Glycerine is commonly incorporated in laundry bar compositions. If included, it is typically at concentrations up to about 3%, preferably about 0.5-1.5%. 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-anilino-6- bis(2-hydoxyethyl) amino-l,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-l,3,5-triazin-2- yl) amino]stilbene-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. If included, they are typically at levels up to about 0.5%o.

Another optional component of the subject invention composition is a photobleach material, particularly phthalocyanine photobleaches which are described in U.S. Patent 4,033,718 issued July 5, 1977, incorporated herein by reference. Preferred photobleaches are metal phthalocyanine compounds, the metal preferably having a valance of +2 or +3; zinc and aluminum are preferred metals. Such photobleaches are available, for example, under the tradename TINOLUS or as zinc phthalocyanine sulfonate. The photobleach components, if included, are typically in the subject compositions at levels up to about 0.02%, preferably from about 0.001% to about 0.015%, more preferably from about 0.002% to about 0.01%.

Another useful optional component of the subject compositions are detergent enzymes. Particularly preferred are cellulase, lipase, protease, amylase, and mixtures thereof. Enzymes, if included, are typically at levels up to about 5%, preferably about 0.5-3%.

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 are mixed in the blender. The dihydric alcohol can be added at any step in the blending process; preferably, the dihydric alcohol is added after neutralization of the acid precursor of the surfactant. Alkyl benzene sulfonic acid (when used) is added into a mixture of alkaline inorganic salts, strong electrolyte salts, and fillers (preferably including sodium carbonate) and the resulting partly neutralized mixture is mechanically worked to effect homogeneity and to complete the neutralization of the mixture. Once the neutralization reaction is completed optional surfactants are added, followed by the builder and any additional optional components. If desired, polyphosphate can be used as an alkaline salt in the neutralization. The mixing can take from one minute to one hour, with the usual mixing time being from about four 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. 400 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.

Examples of the invention are set forth hereinafter by way of illustration and are not intended to be in any way limiting of the invention.

EXAMPLES A-H

Synthetic laundry bars of the present invention, having the following compositions are prepared by conventional blending, milling and plodding procedures.

Component % Weight

A B C D

Tallow Soap (Na) 5 0 0 0

Coconut Soap (Na) 0 5 0 0

Alkyl Sulfate (Na) 20 20 30 25

Linear Alkyl Benzene 0 0 0 5

Sulfonate (Na)

STPP 15 15 15 15

Carboxymethyicellulose 1 1 1 1

Sodium Carbonate 10 10 10 10

Moisture 5 5 5 5

(1,2) Propylene glycol 0.5 0.5 0.5 0.5

Misc. ! Balance Balance Balance Balance

Total 100 100 100 100 'Misc. ingredients include detersive adjuvant ingredients, including Calcium Carbonate)

Component % Weight

E F G H

Tallow Soap (Na) 0 5 5 0

Alkyl Sulfate (Na) 20 20 20 30

AES (C45E1 S) 5 0 0 0

Linear Alkyl Benzene 0 5 0 0

Sulfonate (Na)

Perborate 0 0 0 6

STPP 15 15 15 15

Carboxymethylcellulose 1 1 1 1

Sodium Carbonate 10 10 10 10

Moisture 5 5 5 3

(2,3) Butylene glycol 0.5 0 0.5 0

(1,2) Propylene glycol 0 0.5 0 0.5

Misc.¹ Balance Balance Balance Balance

Total 100 100 100 100

'Misc. ingredients include detersive adjuvant ingredients, including Calcium Carbonate)

Claims

WHAT IS CLAIMED IS:

1. A synthetic laundry detergent bar composition comprising:

B. no more than about 10% soap;

C. from about 5% to about 50% detergent builder; and

D. from about 0.05% to about 2% dihydric alcohol.

2. A bar composition as claimed in Claim 1, further comprising an oxygen bleach.

3. A bar composition as claimed in Claim 1, wherein said dihydric alcohol has from two to six carbon atoms.

4. A bar composition as claimed in Claim 2, wherein said oxygen bleach is selected from the group consisting of sodium perborate, sodium carbonate, and mixtures thereof.

5. A bar composition as claimed in Claim 2, wherein said synthetic anionic surfactant is selected from the group consisting of C J O-18 ^nnear alkyl benzene sulfonates, C 10-14 alkyl glyceryl ether sulfonates, C j ø- 18 alkyl sulfates, and mixtures thereof.

6. A bar composition as claimed in Claim 3, wherein said dihydric alcohol is selected from the group consisting of propylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, butylene glycol (2,3- dihydroxy butane), pentamethylene glycol (1,5- pentanediol), hexylene glycol, dipropylene glycol, and mixtures thereof.

7. A bar composition as claimed in Claim 3, wherein said detergent builder is selected from the group consisting of water-soluble alkali-metal salts of phosphate, pyrophosphates, orthophosphates, tripolyphosphates, higher polyphosphates, and mixtures thereof.

8. A synthetic laundry detergent bar composition comprising:

A. from about 15% to about 30% synthetic anionic surfactant, wherein at least 20% of the total surfactant component is alkyl sulfate;

B. from about 1% to about 8% soap;

C. from about 10% to about 30% detergent builder; and

D. from about 0.01% to about 0.5% dihydric alcohol selected from the group consisting of propylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, butylene glycol (2,3- dihydroxy butane), pentamethylene glycol (1,5- pentanediol), hexylene glycol, dipropylene glycol, and mixtures thereof.

9. A bar composition as claimed in Claim 8, further comprising no more than about 20% oxygen bleach.

10. A bar composition as claimed in Claim 9, further comprising from about 1% to about 10% oxygen bleach selected from the group consisting of sodium perborate, sodium carbonate, and mixtures thereof.