WO2000055290A1

WO2000055290A1 - Laundry prespotter

Info

Publication number: WO2000055290A1
Application number: PCT/US2000/006092
Authority: WO
Inventors: Anne M. Brunn
Original assignee: S. C. Johnson & Son, Inc.
Priority date: 1999-03-16
Filing date: 2000-03-09
Publication date: 2000-09-21
Also published as: AU3732200A

Abstract

Disclosed herein are surfactant complexes and methods for using them. The complexes contain multiple nonionic surfactants that have HLB values that are distinct from each other, yet within a narrow HLB range. The surfactants are complexed with associative polymeric thickeners. These complexes can be used as laundry pre-spotters.

Description

LAUNDRY PRESPOTTER

Technical Field The present invention relates to water soluble surfactant complexes used for laundry pre-spotters. More particularly it relates to surfactant/associative polymeric thickener complexes where multiple nonionic surfactants with distinct HLB values are present in relatively low concentrations.

Background Art

Laundry detergents are often deficient in handling stains due to grass, blood, oil, greases, and certain other sources. Various compositions have therefore been developed as "pre-spotters" or "pre-washes". See e.g. U.S. patent 5,205,960. The disclosure of this patent (and of all other publications described herein) are incorporated by reference as if fully set forth herein.

Such compositions are typically applied directly to difficult stains a few minutes before the normal washing process. However, those pre-spotters which are the most effective against stains can sometimes also lift the dye from cloth so as to create an undesirable faded area. More generally, it is desirable to have effective hard surface cleaners that use relatively low levels of surfactants.

There have been some attempts to combine polymeric thickeners with surfactants to improve cleaning characteristics. See e ^ U.S. patents 5,648,326 and 5,652,208, and PCT publication WO 98/12297. While these thickeners do improve performance, particularly when the thickener is of the type described in WO 98/12297, some stains continue to remain resistant to cleaning by such prespotters.

Disclosure of Invention In one aspect the invention provides a laundry prespotter surfactant complex. The complex has at least 2% and less than 10%, by weight, of nonionic surfactant which is a mixture of a first nonionic surfactant and a second, different nonionic surfactant. The nonionic surfactants individually have an average HLB value of between 7.5 and 14 and individually have an average HLB value that is at least 1.0 different from the other nonionic surfactant. Preferably, one of the HLB values is between 7.5 and 9 and the other HLB value is between 12 and 14.

There is also from 0.01% to 10% by weight of an associative polymeric thickener that has more than two alkyl tails that have between ten and twenty- four carbons in them and at least 5% (preferably at least 50%, even more preferably at least 80%) by weight water.

In an alternative form, the complex also has a third nonionic surfactant that individually has an average HLB value between 7.5 and 14 and individually has an average HLB value that is at least 1.0 different from both of the other nonionic surfactants.

The third surfactant preferably has an HLB value of between 10.5 to 11.5.

When two nonionic surfactants are used, there is preferably less than 5% total nonionic surfactant.

The nonionic surfactants are preferably ethoxylated long chain (e.g. C₆-C₂₂) alcohols; propoxylated/ethoxylated long chain alcohols such as poly-tergents from Olin

Corp. and Plurafac from BASF Corp.; ethoxylated nonylphenols, such as the Surfonic N Series available from Huntsman Corp.; ethoxylated octylphenols, including the Triton X Series available from Rohm & Haas; and ethoxylated secondary alcohols, such as the Tergitol Series available from Union Carbide. Most preferably tri-decyl alcohols such as Iconol TDA-3, TDA-6, and/or TDA-8 (available from BASF Corp) and another ethoxylated alcohol such as Plurafac AO8-A (also available from BASF Corp.) are used. In this regard, Iconol TDA-3 has an HLB of about 8, Iconol TDA-6 has an HLB of about 11, Iconol TDA-8 has an HLB of about 13, and Plurafac A08-A has an HLB of about 13. Also, they are compatible with each other, and each has desirable characteristics for fabric cleaning.

If desired, anionic, cationic, or amphoteric surfactants can also be added, but this is usually not preferred.

Associative thickeners are water-soluble or water swellable polymers that have chemically attached hydrophobic groups that are capable of nonspecific hydrophobic associations. They are also known as hydrophobically modified water soluble polymers.

Associative thickeners have traditionally been used in latex paint technology as rheological altering material. See, Associative Thickeners. (Handbook Coat. Addition) Schaller and Sperry, Dekker, New York, N.Y., (1992) Vol. 2, pp. 105-63. They have also been used in liquid soap compositions for altering the rheology of the compositions to alleviate post-use dripping problems of liquid hand soaps from soap dispensing units.

More recently, they have been used with high levels of surfactants in certain cleaners. The preferred associative thickeners utilized in the present invention are water soluble and impart pseudo plastic characteristics to laundry pre-spotter compositions after the polymer is neutralized to a pH of 5.5 or more. Such associative thickeners are generally supplied in the form of an acidic aqueous emulsion or dispersion.

Some associative thickeners of this type are addition polymers of three components: an alpha-beta-monoethylenically unsaturated monocarboxylic acid or dicarboxylic acid of from 3 to 8 carbon atoms such as acrylic acid or methacrylic acid to provide water solubility, a monoethylenically unsaturated copolymerizable monomer lacking surfactant capacity such as methyl acrylate or ethyl acrylate to obtain the desired polymer backbone and body characteristics, and a monomer possessing surfactant capacity which provides the pseudo plastic properties to the polymer and is the reaction product of a monoethylenically unsaturated monomer with a nonionic surfactant compound wherein the monomer is copolymerizable with the foregoing monomers.

Additional associative polymer thickeners include maleic anhydride copolymers reacted with nonionic surfactants such as ethoxylated C₁₂-C₁₄ primary alcohol available under the trade name Surfonic L Series from Huntsman Corp. and Gantrez AN-119 from

ISP.

Especially preferred thickeners are alkali-soluble acrylic emulsion polymers available under the trademark Acusol^® from Rohm and Haas Co. Acusol 823A is a 30% active emulsion polymer composed of 44% methacrylic acid, 50% ethyl acrylate and 6% stearyl oxypoly ethyl methacrylate emulsion polymer having approximately 10 moles of ethylene oxide. See also the polymers generally described in U.S. Patent 4,351,754.

Acusol 820 is also suitable as are Rheovis CR and CRX from Allied Colloids and ALCO

EXP 2244 and 2245 from ALCO Chemical.

The associative thickener is preferably about 1-3% by weight (0.3-0.9% active polymer solids) when the complex is be used as a laundry pre-spotter or hard surface cleaner.

Various conventional additives can be used with the complexes. Mildly alkaline pH (e.g. about 7-9%) can be achieved with NaOH (or KOH) buffered with citric acid.

Borax can be added as a builder salt (as can other known builders and chelating agents). Standard enzymes, stain release agents, dispersing agents, solvents, preservatives, and fragrances can also be included such as Savinasa 16.OL (enzyme; Novo); Sokalan HP22

(an acetated polyvinyl alcohol stain release agent; BASF); Acusol 445N (a dispersing agent); and Kathon CG-ICP and Proxel GXL (preservatives from Rohm & Haas and ICI

PLC/Zeneca Limited, respectively). Dyes, optical brighteners, corrosion inhibitors, defoamers, bactericides, bacteriostats, and the like can also be added. Extra additives of this type will normally total less than 15% by weight of a pre-spotter composition.

In another form, a method of laundering an article is disclosed. One applies an effective amount of the above complexes to a stain on an article to be laundered, and then launders the article. In yet another form, the invention provides a method of cleaning a stain from the surface of a clothing article. One applies an effective amount of the above complex to a stain on the article surface. One then waits at least two hours before laundering the article and then launders the article.

The complexes of the present invention can be delivered by pouring, spraying, or discharge from a squeeze bottle. Rubbing the complex onto the stain improves the effectiveness of the complex.

It will be appreciated that it has been discovered that providing multiple nonionic surfactants within the specified HLB range, yet distinct from each other by at least one HLB value (e.g. 8, 11 and 13) markedly improves cleaning characteristics for certain types of stains. The objects of the present invention therefore include providing surfactant complexes of the above kind:

(a) which contain relatively small amounts of surfactant, yet are still highly effective;

(b) which can be used as a laundry pre-spotter with little or no effect on the natural color of most common clothing items;

(c) which use only environmentally acceptable materials; and

(d) which are particularly useful on stains that have in them a variety of staining materials.

These and still other objects and advantages of the present invention will be apparent from the description which follows. The following description is merely of the preferred embodiments. The claims should therefore be looked to in order to understand the full scope of the invention.

Detailed Description of Invention The compositions of the present invention will now be illustrated by the following examples, wherein all percentages are by weight. Liquid compositions in the examples listed below were prepared as follows. We mixed 75 ?F tap water with borax, citric acid, Acusol 823, and enough sodium hydroxide to reach pH 5.5 to 6.0. We then added the Sokolan HP-22, the surfactants, Acusol 445N, and the fragrance. We then added the remainder of the sodium hydroxide, followed by the enzyme, Kathon, and Proxel.

After treatment of a selection of fabrics that were stained with commonly found staining materials, we judged the effectiveness of the above formulae using a variety of different techniques. In one approach we used colorimeter analysis. In another we had a panel of observers give their subjective rating.

For example, in one experiment we compared the effectiveness of Formula A with an identical formula except that the latter formula had Neodol 23-4 (at a 4% amount) substituted for the two nonionic surfactants in Formula A. Both prespotters were tested on swatches of four types of fabric: white cotton; blue cotton; white 65/35 polyester/cotton blend; blue 65/35 polyester/cotton blend. A panel of seventeen different types of staining materials typically encountered by a consumer (e.g. chocolate; motor oil; grass; etc.) was used. After the stains dried, a standard amount of prespotter being tested was applied and the swatches were allowed to sit for a similar period before washing. They were then washed in a standard washing machine using a conventional washing protocol. For each of the fabric types the Formula A achieved overall better performance, with the results being particularly striking for blue cotton fabric. These tests confirmed that the use of the multiple nonionic surfactants with specified HLB values in combination with the associative polymeric thickener leads to surprising effectiveness. While the above surfactants complexes are preferred, a variety of other complexes including other multiple nonionics are also intended to be within the scope of the claims. Thus, the claims below should be looked to in order to understand the full scope of the present invention.

Industrial Applicability This invention provides laundry pre-spotters that are especially effective against stains containing multiple different components.

Claims

Claims:

1. A laundry prespotter surfactant complex, comprising: at least 2% and less than 10%, by weight, of nonionic surfactant, wherein the nonionic surfactant comprises a mixture of a first nonionic surfactant and a second, different nonionic surfactant, both of the nonionic surfactants individually having an average HLB value between 7.5 and 14 and individually having an average HLB value that is at least 1.0 different from the other nonionic surfactant, from 0.01% to 10% by weight of an associative polymeric thickener that has more than two alkyl tails that have between ten and twenty-four carbons in them; and at least 5% by weight water.

2. The complex of claim 1, wherein the first and the second nonionic surfactants are both selected from the group consisting of ethoxylated alcohols, propoxylated alcohols, and ethoxylated/propoxylated alcohols.

3. The complex of claim 1, further comprising a third nonionic surfactant that individually has an average HLB value between 7.5 and 14 and individually having an average HLB value that is at least 1 HLB different from both of the other nonionic surfactants.

4. The complex of claim 1 , wherein there is at least 50% by weight water.

5. The complex of claim 1, wherein there is at least 80% by weight water.

6. The complex of claim 1, wherein the associative polymeric thickener an emulsion polymer of methacrylic acid, ethyl acrylate and stearyl oxypoly ethyl methacrylate emulsion polymer with ethylene oxide.

7. The complex of claim 1, further comprising an enzyme, borax, citric acid, and sodium hydroxide.

8. A method of laundering an article, comprising the steps of: applying an effective amount of the claim 1 complex to a stain on an article to be laundered; and then laundering the article.

9. A method of cleaning a stain from the surface of a clothing article, comprising the steps of; apply an effective amount of the claim 1 complex to a stain on the article surface; thereafter waiting at least two hours before laundering the article; and then laundering the article.