# Patent

## Title
Dye transfer inhibitors for detergents

## Abstract

This invention provides a liquid laundry detergent product with high detergency and freeze/thaw and high/low temperature stability. The detergent product is an aqueous medium having a content of sodium carbonate detergent builder, and a surfactant blend of specific amounts of two anionic salt compounds and two nonionic compounds of specific chemical structure, and an amphoteric compound.

## Background
The subject matter of this patent application is related to that disclosed in copending patent application Ser. No. 08/851,034, filed May 5, 1997; incorporated by reference.

The present invention relates to liquid detergent products which are adapted for home laundry machine washing of fabrics. More specifically the present invention relates to heavy duty liquid laundry detergent products which exhibit superior freeze/thaw and high/low temperature stability, and provide high detergency.

Compared with powder-form detergents, liquid detergents have handling advantages and other performance features. In particular, larger quantities of nonionic surfactants can be incorporated in liquid detergents than in powder-form detergents, which has the advantage of greater effectiveness against oily and greasy soil.

A water-based liquid detergent which contains a mixture of anionic and nonionic surfactants, and in which the nonionic surfactant is 20% or more of the liquid detergent, generally lacks homogeneity and typically undergoes phase separation. As another disadvantage, liquid detergents of this type often exhibit a higher viscosity than is desirable for normal laundry usage.

Further to liquid laundry detergent compositions, the incorporation of a major amount of detergent builder poses a significant formulation challenge since the presence of a major quantity of detergent builder inevitably causes the detergent composition to phase separate. Liquid detergent formulations that contain a detergent builder ingredient require careful control of the surfactant to builder ratio so as to prevent salting-out of the surfactant phase.

In another aspect, liquid laundry detergent compositions are susceptible to instability under extended freeze/thaw and high/low temperature conditions.

A variety of improved types of liquid detergent compositions are described in publications such as U.S. Pat. Nos. 3,929,680; 4,092,273; 4,105,592; 4,110,262; 4,201,686; 4,368,147; 4,490,285; 4,671,895; 4,747,977; 5,049,302; 5,132,053; 5,205,960; 5,215,683; 5,403,516; 5,409,629; 5,500,151; 5,529,724; 5,536,440; and 5,597,507; incorporated by reference.

There remains a continuing interest in the development of improved liquid detergent compositions which overcome one or more inherent disadvantages associated with liquid detergent products.

Accordingly, it is an object of this invention to provide a heavy duty liquid detergent composition which contains a high level of active surfactant ingredients.

It is another object of this invention to provide a liquid laundry detergent product which has a content of detergent builder, and which has clarity and stability without the inclusion of a hydrotrope constituent.

It is a further object of this invention to provide a liquid laundry detergent product which provides high detergency under fabric washing conditions, and which exhibits freeze/thaw and high/low temperature stability.

Other objects and advantages of the present invention shall become apparent from the accompanying description and examples.

One or more objects of the present invention are accomplished by the provision of a liquid laundry detergent product with high detergency and with freeze/thaw and high/low temperature stability, which is an aqueous medium having a content comprising (1) between about 0.5-12 weight percent of sodium carbonate detergent builder ingredient; and (2) between about 5-35 weight percent of a detergent active ingredient which is a surfactant blend comprising (a) between about 15-55 weight percent, based on the surfactant weight, of an anionic salt compound corresponding to the formula:

where R is a C.sub.10 -C.sub.16 alkyl group, and M is an alkali metal or ammonium cation, (b) between about 15-55 weight percent, based on the surfactant weight, of an anionic salt compound corresponding to the formula:

where R is a C.sub.10 -C.sub.16 alkyl group, and M is an alkali metal or ammonium cation, (c) between about 15-55 weight percent, based on the surfactant weight, of a nonionic compound corresponding to the formula:

where R is a C.sub.10 -C.sub.16 alkyl group, (d) between about 15-55 weight percent, based on the surfactant weight, of a nonionic compound corresponding to the formula:

where R is a C.sub.10 -C.sub.16 alkyl group, and (e) between about 0.5-15 weight percent, based on the surfactant weight, of an amphoteric compound.

In another embodiment this invention provides a detergent active composition which is a surfactant blend comprising (a) between about 15-55 weight percent of an anionic salt compound corresponding to the formula:

where R is a C.sub.10 -C.sub.16 alkyl group, and M is an alkali metal or ammonium cation, (b) between about 15-55 weight percent of an anionic salt compound corresponding to the formula:

where R is a C.sub.10 -C.sub.16 alkyl group, and M is an alkali metal or ammonium cation, (c) between about 15-55 weight percent of a nonionic compound corresponding to the formula:

where R is a C.sub.10 -C.sub.16 alkyl group, (d) between about 15-55 weight percent of a nonionic compound corresponding to the formula:

where R is a C.sub.10 -C.sub.16 alkyl group, and (e) between about 0.5-15 weight percent of an amphoteric compound.

As described more fully hereinafter, a present invention liquid laundry detergent product is a clear homogeneous aqueous solution which is stable under freeze/thaw and high/low temperature conditions, and which provides high detergency when utilized in home laundry machine washing of fabrics.

A present liquid laundry detergent product does not include any non-detergent solubilizer or hydrotrope to achieve clarity and stability. A specific combination of specific surfactant and detergent builder ingredients is an essential aspect of the present invention.

Suitable water-soluble detergent builder compounds for a present invention liquid laundry detergent product as defined herein include alkali metal and ammonium carbonates, bicarbonates, sesquicarbonates, silicates, phosphates, orthophosphates, pyrophosphates, tripolyphosphates, borates, and the like. Sodium and potassium carbonates, bicarbonates and sesquicarbonates are illustrative of preferred types of inorganic salt detergent builder compounds.

A present invention laundry detergent product can contain other optional detergent adjuncts, which include lather boosters such as alkanolamines, lather depressants such as alkyl phosphates or silicones, anti-redeposition agents such as sodium polycarboxylate, oxygen-releasing bleaching agents such as sodium perborate or sodium percarbonate, fabric softening agents, fluorescent agents, perfumes, enzymes, germicides, colorants, and the like.

A preferred type of anti-redeposition agent is sodium polyacrylate having a molecular weight of 2000-50,000.

It is generally desirable to include between about 1-15 weight percent of sodium or potassium silicate ingredient in the liquid laundry detergent product to provide buffering capacity and to prevent corrosion of metal parts in washing machines.

The four detergent active anionic/nonionic constituents of the novel surfactant composition of a present invention laundry detergent product are prepared as a blended admixture by a partial sulfation procedure similar to that described in U.S. Pat. No. 4,464,292, incorporated by reference.

In a typical sulfation procedure, a selected nonionic ethoxylated alcohol mixture is admixed with 96-100% concentrated sulfuric acid, in a proportion of about 0.5-2 moles of sulfuric acid per mole of nonionic ethoxylated alcohol mixture. The exothermic reaction admixture is maintained at a temperature between about 90.degree.-150.degree. F. for a sufficient period between about 0.5-45 minutes to convert about 30-80 weight percent of the initial ethoxylated alcohol mixture to a sulfate ester derivative.

The resulting partially sulfated nonionic ethoxylated alcohol blend is a liquid admixture of residual unsulfated ethoxylated alcohols, and sulfated ethoxylated alcohols, and lesser quantities of residual unsulfated unethoxylated alcohols, and sulfated unethoxylated alcohols.

A commercial nonionic ethoxylated alcohol product such as Neodol 23-3 is composed of a liquid mixture of C.sub.12 -C.sub.13 alcohols which have an average content of three ethoxylate groups per alcohol molecule. A commercial nonionic ethoxylated alcohol product such as Neodol 23-3 typically has a content of up to about 20 weight percent of unethoxylated alcohols such as C.sub.12 -C.sub.13 alcohols. Nominally 24-3 refers to a mixture of C.sub.12 -C.sub.14 alcohols which have an average content of three ethoxylate groups per alcohol molecule, and 26-7 refers to a mixture of C.sub.12 -C.sub.16 alcohols which have an average content of seven ethoxylate groups per alcohol molecule.

The blend of partially sulfated nonionic ethoxylated alcohol constituents is neutralized with a basic reagent such as alkali metal hydroxide or carbonate, and then combined with an amphoteric constituent to provide the novel detergent active surfactant composition of the present invention.

Amphoteric surfactants are commercially available under tradenames which include Sipoteric (Alcolac), Zwittergent (Calbiochem), Appho (Capital City Products), Deriphat (Henkel), Amphoterge (Lonza), Armeen (Akzo), Mirataine (Miranol), Monaterics (Mona Industries), Mafo (PPG/Mazer Chemicals), Alkateric (Rhone-Poulenc), Scheroterics (Scher Chemicals), Varion (Sherex Chemical Co.), and Emcol (Witco).

A preferred class of amphoteric surfactant compounds are N--(C.sub.8 -C.sub.18 aliphatic) derivatives of aminoalkanoic acids in the form of alkali metal or ammonium salts. This type of compound can be prepared by the reaction of a primary amine with a C.sub.2 -C.sub.6 acrylic type monomer: NHCH.sub.2 CH.sub.2 CO.sub.2 M+R--CH.sub.2 N(CH.sub.2 CH.sub.2 CO.sub.2 M).sub.2

where M is hydrogen or a metal cation, and R is a C.sub.8 -C.sub.18 aliphatic radical which typically is a mixture derived from a natural product such as coconut oil or tallow.

Illustrative of preferred quaternary surfactants are the alkali metal salt form of N-coco 3-aminopropionic acid, N-lauryl/myristyl 3-aminopropionic acid, N-tallow 3-iminopropionic acid, N-coco 3-aminobutanoic acid, and the like. Sodium, N-coco 3-aminopropionate is a particularly preferred amphoteric surfactant, because it exhibits an optimal enhancing effect on the detergency of an invention heavy duty liquid laundry detergent product.

The superior freeze/thaw and high/low temperature stability, in addition to detergency properties, of an invention liquid laundry detergent product mainly are attributable to the content of the partially sulfated and neutralized anionic/nonionic surfactant blend which has the specifications described herein. The inclusion of an amphoteric surfactant and a detergent builder provides further enhancement of the detergency properties.

The following examples are further illustrative of the present invention. The components and specific ingredients are presented as being typical, and various modifications can be derived in view of the foregoing disclosure within the scope of the invention.

A Standard Wash Test for detergency performance by instrumental evaluation of soiled swatches washed with a detergent formulation in a washing machine is conducted with the following equipment and procedures. Standard Test Swatches Per Treatment Number                     Supplier ______________________________________ SOIL SWATCHES 4        Standard Soil on Cotton Test Fabrics 4        Dust Sebum on Cotton Scientific Services 4        Clay on Cotton    Scientific Services 4        Dust Sebum on Poly/Cotton Scientific Services 4        Clay on Poly/Cotton Scientific Services STAIN SWATCHES 4        Beef Gravy on Cotton Scientific Services 4        Ketchup on Cotton Scientific Services 4        Coffee on Cotton  Scientific Services 4        Grass on Cotton   Scientific Services WHITENESS SWATCHES 4        Merc. Combed Broadcloth Test Fabrics 100% Cotton S419 ______________________________________

The four swatches are split for duplicate machine treatments. 250 ppm software program. attached to pillowcases. There are four pillowcases with swatches attached for each treatment. Two pillowcases are put in one washer and the other two are put in a duplicate washer. used; for over 100 ppm 2:1 hardness solution used) to add to washer is determined. Desired hardness for each washer for wash and rinse cycles is measured out. reached. ##EQU1## 7. Washer to be used for each treatment and duplicate sets are randomly selected. setting. The machines are started and the temperatures are adjusted. Starting with the first washer, agitate, then add water hardness solution and detergent. Test load and pillowcases with labeled swatches attached and randomly added. The machine is set for 14 minutes. The washer is started, and agitation is timed for 12 minutes. rinse/spin cycle is started. hardness solution is added to water, and the washer is allowed to complete cycles. dried on medium to high setting in dryer. stripping detergent and 1 cup of bleach on hot setting. The cycle is repeated with 1 cup of bleach. The ballast is dried in industrial dryer on medium setting for about 30 minutes. swatches are read on the colorview. Swatches are read on the labeled side and in the same position on colorview orifice as initial readings. ##EQU2## Prewash: -b.sub.o).sup.2 !.sup.1/2

Postwash: -b.sub.o).sup.2 !.sup.1/2

Final Swatch readings the 95% confidence level for treatment comparison is calculated using StatGraphics program, with anova analysis of variance, multiple range test.

This Example illustrates the increased detergency of a liquid laundry detergent product in accordance with the present invention.

Ethoxylated alcohol mixtures are sulfated to a 58% conversion level with a 1.2 molar excess of 99.6% sulfuric acid.

Textile swatches with different types of stains and soils are utilized.

a 120 g 58% converted ES prepared by mixing 45.95 g 23-3 and 45.95 g 26-7 with 28.10 g 99.6% H.sub.2 SO.sub.4 ; 113.23 g of the ES mix neutralized with 50% NaOH (32.69 g) to pH 7-9 in 800 g distilled water; qs with distilled water to 1000 g.

The comparative data in the Table demonstrate that a present invention liquid detergent formulation B performs well in textile stain and soil cleaning tests in comparison with formulations A and C which have correspondence with a commercial heavy duty liquid detergent product.

Similar enhancement of detergency is observed when amphoteric Deriphat 151C (Henkel) sodium salt is replaced with amphoteric N-lauryl/myristyl 3-aminopropionic acid or N-tallow 3-imino(propionic acid).sub.2 or N-coco 3-aminobutanoic acid sodium salt.

The amphoteric functionality of the surfactant is a contributing factor to the increased detergency of an invention liquid laundry detergent product.

The comparative data demonstrate that the invention composition of five anionic/nonionic and amphoteric surfactants enhances the detergency of a heavy duty liquid laundry detergent product.

Comparative testing also demonstrates that a specific blend of 3 ethoxy mole and 7 ethoxy mole ethoxylated alcohol and ethoxylated alcohol sulfate (50 weight % 3 mole/50 weight % 7 mole) in combination with Deriphat 151C (N-coco 3-aminopropionic acid) sodium salt passes 3 cycle freeze-thaw and 2 week high/low temperature stability tests when admixed with 3% soda ash in an aqueous medium. ______________________________________ STANDARD WASH RESULTS AT 95.degree. F./100 PPM IN PRESENCE OF SODA ASH PERCENT STAIN/SOIL REMOVAL ______________________________________ A CONTROL ES 17.7 g.sup.(1) ASH 3.0 g ______________________________________ STAINS Grass          Cotton   53.23 Coffee         Cotton   57.60 Beef Gravy     Cotton   81.85 Ketchup        Cotton   90.85 Makeup         Cotton   33.83 EMPA 116       Cotton   35.54 EMPA 117       Polycotton 30.22 SOILS Sebum          Cotton   43.21 Standard       Cotton   22.90 EMPA 101       Cotton   28.83 Clay           Cotton   54.02 Sebum          Polycotton 54.35 EMPA 104       Polycotton 28.41 Clay           Polycotton 72.47 ______________________________________ B ES 17.7 g C 151C.sup.(2) 4.0 g ES 21.7 g ASH 3.0 g ASH 3.0 g ______________________________________ STAINS Grass       Cotton    53.56     55.76 Coffee      Cotton    62.55     62.01 Beef Gravy  Cotton    84.43     82.76 Ketchup     Cotton    92.15     90.59 Makeup      Cotton    32.95     35.65 EMPA 116    Cotton    37.77     36.60 EMPA 117    Polycotton 39.02     32.60 SOILS Sebum       Cotton    44.31     43.50 Standard    Cotton    26.55     24.94 EMPA 101    Cotton    33.79     28.53 Clay        Cotton    52.41     55.16 Sebum       Polycotton 53.53     57.46 EMPA 104    Polycotton 33.23     28.75 Clay        Polycotton 71.62     73.47 ______________________________________ A CONTROL ES 17.7 g.sup.(1) ASH 3.0 g ______________________________________ WHITENESS INDEX delta B             -0.54 delta WIE           2.93 pH 1 min.           9.30 10 min.             9.30 OVERALL STAIN REMOVAL 54.73 OVERALL SOIL REMOVAL 43.46 ______________________________________ B ES 17.7 g C 151C 4.0 g ES 21.7 g ASH 3.0 g ASH 3.0 g ______________________________________ WHITENESS INDEX delta B            0.51      -0.55 delta WIE          2.84      2.87 pH 1 min.          9.3       9.30 10 min.            9.3       9.20 OVERALL STAIN REMOVAL 57.49     56.57 OVERALL SOIL REMOVAL 45.06     44.54 ______________________________________ LSD ______________________________________ STAINS Grass            Cotton   2.86 Coffee           Cotton   5.28 Beef Gravy       Cotton   2.19 Ketchup          Cotton   2.22 Makeup           Cotton   3.08 EMPA 116         Cotton   2.70 EMPA 117         Polycotton 2.13 SOILS Sebum            Cotton   3.71 Standard         Cotton   2.86 EMPA 101         Cotton   2.45 Clay             Cotton   2.41 Sebum            Polycotton 2.33 EMPA 104         Polycotton 3.35 Clay             Polycotton 3.50 WHITENESS INDEX delta B                   0.10 delta WIE                 0.30 OVERALL STAIN REMOVAL 2.92 OVERALL SOIL REMOVAL  2.94 ______________________________________ EMPA 116 = Blood, milk and carbon black on cotton. EMPA 117 = Blood, milk and carbon black on poly/cotton. EMPA 101 = Carbon black and olive oil on cotton. EMPA 104 = Carbon black and olive oil on poly/cotton .sup.(1) weight of surfactant blend in test sample. .sup.(2) Deriphat 151C (Henkel) amphoteric surfactant; Ncoco derivative o 3aminopropionic acid which is converted to a sodium salt before formulation. LSD = least statistical difference.

## Claims

1. A liquid laundry detergent product which is a clear, homogeneous aqueous solution that is stable under freeze/thaw and high/low temperature conditions and which provides high detergency, said product comprising: builder ingredient; comprising: neutralized anionic/nonionic surfactant blend containing: component comprising: where R is a C.sub.10 -C.sub.16 alkyl group, and M is an alkali metal or ammonium cation; and where R is a C.sub.10 -C.sub.16 alkyl group; and component comprising: where R is a C.sub.10 -C.sub.16 alkyl group, and M is an alkali metal or ammonium cation; and where R is a C.sub.10 -C.sub.16 alkyl group; and wherein (1)(a) comprises from about 30% to about 80% by weight of the (1)(a)(I) anionic salt compound and from 20 to about 70% by weight of the (1)(a)(ii) nonionic compound; about 80% by weight of the (B)(1)(a)(I) anoinic salt compound and from about 20% to about 70% by weight of the (B)(1)(a)(ii) nonionic compound.

2. A laundry detergent product in accordance with claim 1 wherein the detergent builder ingredient comprises a mixture of sodium bicarbonate and sodium carbonate.

3. A laundry detergent product in accordance with claim 1 wherein the detergent builder ingredient comprises a mixture of sodium sesquicarbonate and sodium carbonate.

4. A laundry detergent product in accordance with claim 1 wherein the amphoteric surfactant comprises an N--(C.sub.8 -C.sub.18 aliphatic) derivative of an aminoalkanoate salt.

5. A laundry detergent product in accordance with claim 1 wherein the amphoteric surfactant comprises sodium N-coco 3-amino-propionate.

6. A laundry detergent product in accordance with claim 1 wherein the amphoteric surfactant comprises sodium N-lauryl/myristyl 3-aminopropionate.

7. A laundry detergent product in accordance with claim 1 wherein the amphoteric surfactant comprises disodium N-tallow 3-imino-propionate.

8. A laundry detergent product in accordance with claim 1 wherein the amphoteric surfactant comprises disodium N-lauryl 3-imino-propionate.

9. A laundry detergent product in accordance with claim 1 wherein the amphoteric surfactant comprises sodium N-coco 3-aminobutanoate.

10. A laundry detergent product in accordance with claim 1 which contains between about 1-15 weight percent of alkali metal silicate corrosion inhibitor.

11. A detergent active composition in accordance with claim 2 wherein the amphoteric surfactant comprises a N--(C.sub.8 -C.sub.18 aliphatic) derivative of an aminoalkanoate salt.

12. A detergent active composition in accordance with claim 2 wherein the amphoteric surfactant comprises sodium N-coco 3-amino-propionate.

13. A detergent active composition in accordance with claim 2 wherein the amphoteric surfactant comprises sodium N-lauryl/myristyl 3-aminopropionate.

14. A detergent active composition in accordance with claim 2 wherein the amphoteric surfactant comprises disodium N-tallow 3-imino-propionate.

15. A detergent active composition in accordance with claim 2 wherein the amphoteric surfactant comprises disodium N-lauryl 3-imino-propionate.

16. A detergent active composition in accordance with claim 2 wherein the amphoteric surfactant comprises sodium N-coco 3-aminobutanoate.

17. A product according to claim 1, wherein the first partially sulfated and neutralized anionic/nonionic surfactant component (B)(1)(a) comprises about 58% by weight of the (B)(1)(a)(i) anionic salt compound and about 42% by weight of the (B)(1)(a)(ii) nonionic compound.

18. A product according to claim 1, wherein the second partially sulfated and neutralized anionic/nonionic surfactant component (B)(1)(b) comprises from about 30% to about 80% by weight of the (B)(1)(b)(i) anionic salt compound and from about 20% to about 70% by weight of the (B)(1)(b)(ii) nonionic compound.

19. A product according to claim 1, wherein the second partially sulfated and neutralized anionic/nonionic surfactant component (B)(1)(b) comprises about 58% by weight of the (B)(1)(b)(i) anionic salt compound and about 42% by weight of the (B)(1)(b)(ii) nonionic compound.

20. A product according to claim 1, wherein the partially sulfated and neutralized anionic/nonionic surfactant blend (B)(1) comprises about 50% by weight of the first partially sulfated and neutralized anionic/nonionic surfactant component (B)(1)(a) and about 50% by weight of the second partially sulfated and neutralized anionic/nonionic surfactant component (B)(1)(b).

21. A product according to claim 1, wherein the product is free of hydrotropes.

22. A detergent active composition which, when combined with water and a sodium carbonate detergent builder ingredient so as to form an aqueous liquid laundry detergent product comprising from about 5 to about 35 weight percent of the detergent active composition and from about 0.5 to 12 weight percent of the sodium carbonate detergent builder ingredient, is capable of providing such detergent product with clarity, homogeneity, stability under freeze/thaw and high/low temperature conditions and high detergency properties, said detergent active composition comprising: neutralized anionic/nonionic surfactant blend containing: component comprising: where R is a C.sub.10 -C.sub.16 alkyl group, and M is an alkali metal or ammonium cation; and where R is a C.sub.10 -C.sub.16 alkyl group; and component comprising: where R is a C.sub.10 -C.sub.16 alkyl group, and M is an alkali metal or ammonium cation; and where R is a C.sub.10 -C.sub.16 alkyl group; and

23. A composition according to claim 22, wherein the first partially sulfated and neutralized anionic/nonionic surfactant component (1)(a) comprises about 58% by weight of the (1)(a)(i) anionic salt compound and about 42% by weight of the (1)(a)(ii) nonionic compound.

24. A composition according to claim 22, wherein the second partially sulfated and neutralized anionic/nonionic surfactant component (1)(b) comprises from about 30% to about 80% by weight of the (1)(b)(i) anionic salt compound and from about 20% to about 70% by weight of the (1)(b)(ii) nonionic compound.

25. A composition according to claim 22, wherein the second partially sulfated and neutralized anionic/nonionic surfactant component (1)(b) comprises about 58% by weight of the (1)(b)(i) anionic salt compound and about 42% by weight of the (1)(b)(ii) nonionic compound.

26. A composition according to claim 22, wherein the partially sulfated and neutralized anionic/nonionic surfactant blend comprises about 50% by weight of the first partially sulfated and neutralized anionic/nonionic surfactant component and about 50% by weight of the second partially sulfated and neutralized anionic/nonionic surfactant component.

27. A composition according to claim 22, wherein the surfactant blend is capable of providing said liquid laundry detergent product with said clarity and stability in the absence of a hydrotrope.