GB2188654A - Stable liquid diperoxyacid bleach - Google Patents

Description

GB2188654A 1

SPECIFICATION

Stable liquid diperoxyacid bleach Reference to Related Application 5 This application is a continuation-in-part of U.S. Patent Application Serial No. 846,381, filed March 31, 1986.

Technical Field

The present invention relates to stable liquid diperoxyacid bleach compositions useful for 10 bleaching fabrics, hard surfaces and other substrates. The compositions contain water-insoluble aliphatic diperoxyacid particles, C11-C13 linear alkylbenzene sulfonate surfactant, cumene sulfonate as an optional ingredient, magnesium sulfate, sodium of potassium sulfate as an optional ingredi ent, and water. The compositions also have a pH of from about 2 to about 4.5 and a viscosity of from about 50 to about 1000 cps at 2WC. The ingredients are combined at certain carefully 15 balanced levels and ratios, as hereinafter described, to provide compositions exhibiting good physical and chemical stability.

Background Art

European Patent Application 160,342, Humphreys et al, published November 6, 1985, dis- 20 closes aqueous liquid bleaching compositions containing organic peroxyacid particles suspended in an acidic surfactant-structured liquid.

U.S. Patent 3,996,152, Edwards et al, issued December 7, 1976, discloses stable, low-pH gels containing peroxyacid bleach particles and a non-starch thickening agent.

U.S. Patent 4,100,095, Hutchins, issued July 11, 1978, discloses the stabilization of peroxya- 25 cid bleaches by the use of certain exotherm control agents.

Despite the above attempts to stabilize liquid diperoxyacid bleaching compositions, there is a continuing need for the development of physically and chemically stable liquid diperoxyacid bleaches having a high level of diperoxyacid and a low viscosity.

30 Summary of the Invention

The present invention relates to a stable liquid bleach composition comprising, by weight:

(a) from about 10% to about 25% of water-insoluble diperoxyacid particles of the formula HOOOC(CH2),,COOOH, wherein n is from about 7 to about 14, said particles having an average size of from about 0.5 to about 15 microns; 35 (b) from about 2% to about 6%, on an acid basis, of a C,,_C,3 linear alkylbenzene sulfonate surfactant; (c) from about 0% to about 8%, on an acid basis, of cumene sulfonate; (d) from about 5% to about 15% of magnesium sulfate; (e) from 0% to about 7% sodium or potassium sulfate; and 40 (f) from about 40% to about 78% water said composition containing from about 3% to about 14% of (b) and (c), from about 5% to about 16% of (d) and (e), and from about 12% to about 30% of (b), (c), (d) and (e); the weight ratio of (a) to (d) being less than about 3:1; and said composition having a pH of from about 2 to about 4.5 and a viscosity of from about 50 to about 1000 eps at 2WC. 45 Detailed Description of the Invention

The liquid bleach compositions herein contain water-insoluble aliphatic diperoxyacid particles, C,,-C,, linear alkylbenzene sulfonate surfactant, cumene sulfonate as an optional ingredient, magnesium sulfate, sodium or potassium sulfate as an optional ingredient and water. These 50 essential ingredients are combined at certain carefully balanced levels and ratios to obtain compositions having a high level of peroxyacid bleach, low product viscosity, and good physical and chemical stability. The composition generally remain as stable suspensions having little or no separation of ingredients during storage, preferably for as long as 2 months at room tempera ture. The compositions also have chemical (i.e., peroxyacid) stability of at least about 80%, with 55 the preferred compositions having at least about 90% stability after 2 months storage at room temperature.

The compositions of the present invention have a pH of from about 2 to about 4.5, preferably from about 2.5 to about 4, most preferably from about 3 to about 3.5, when measured at WC for best peroxyacid bleach stability. 60 The compositions also have a viscosity of from about 50 to about 1000 cps, preferably from about 60 to about 750 cps, more preferably from about 75 to about 500 cps, and most preferably from about 100 to about 350 cps, at 2WC, when measured with an LTV Brookfield

Viscometer, using a No. 3 spindle and a setting of 60 rpm. This relatively low viscosity is desired for convenient pouring from a container by the user. 65 2 GB2188654A 2 The compositions of the present invention contain from about 10% to about 25%, preferably from about 12% to about 22%, more preferably from about 14% to about 20%, by weight, of substantially water-insoluble diperoxyacid particles of the formula HOOOC(CHI)nCOO0H, wherein n is from about 7 to about 14, preferably from about 8 to 12. The particles have an average size of from about 0.5 to about 15, preferably from about 0.5 to about 10, microns. A particularly 5 preferred material is 1,12-diperoxydodecanedioic acid (DPDA).

The compositions contain from about 2% to about 6%, preferably from about 2% to about 4%, by weight on an acid basis, of a water-soluble (e.g., alkali metal, ammonium or alkylolam monium) C,I-C,3 linear alkylbenzene suffonate surfactant. The alkylbenzene sulfonate contributes to physical stability by dispersing the peroxyacid particles. However, since it also increases 10 product viscosity, particularly when used at higher levels within the claimed range and when shorter carbon chain (e.g., Cl, or C12) alkylbenzene suifonates are selected, the type and level of alkylbenzene sulfonate must be selected along with the other ingredients herein to provide the desired viscosity. The C13 alkylbenzene sulfonates are particularly preferred.

The compositions can also contain from 0% to about 8%, preferably from about 1% to about 15 6%, most preferably from about 2% to about 5%, by weight on an acid basis, of a watersoluble (e.g., alkali metal, ammonium or alkylolammonium) cumene sulfonate. Cumene sulfonate also functions as a dispersant for the peroxyacid particles, and it significantly decreases viscosity. It thus can serve as a thinning agent as a partial replacement for the C11-C13 linear alkylbenzene sulfonate surfactant. 20 The bleach compositions herein further contain from about 5% to about 15%. preferably from about 8% to about 12%, by weight, of magnesium sulfate. The magnesium sulfate helps to suspend the diperoxyacid particles via density matching in range of from about 1.15 to about 1.22 g/mi. Magnesium sulfate also functions as an effective exotherm control agent in the present compositions. 25 The compositions further contain from 0% to about 7%. preferably from about 2% to about 6%, by weight, of sodium sulfate or potassium sulfate. Sodium and potassium sulfate, and to a lesser extent the cumene sulfonate, can be used to help match the density of, and thereby suspend. the peroxyacid particles. Mixtures of sodium or potassium sulfate, cumene sulfonate and magnesium sulfate are preferred to avoid adding excessive magnesium hardness to the wash 30 water. The mixture of these salts also appears to be more effective at physically stabilizing the peroxyacid particles since less of the mixture is required to stabilize the composition than when magnesium sulfate alone is used. However, sodium and potassium sulfate significantly increase viscosity, and so their use must be limited to meet the desired viscosity range.

Finally, the compositions contain from about 40% to about 78%, preferably from about 50% 35 to about 70%, by weight, of water.

In addition to the above, the C,,-C,, alkylbenzene sulfonate and cumene sulfonate together should represent from about 3% to about 14%, preferably from about 4% to about 12%, most preferably from about 4% to about 10%, by weight, of the composition to provide sufficient dispersant for the peroxyacid particles while maintaining the desired low viscosity. 40 The magnesium sulfate and sodium or potassium sulfate should represent from about 5% to about 16%, preferably from about 10% to about 15%, by weight of the composition in order to adequately suspend the peroxyacid particles. The weight ratio of magnesium sulfate to sodium or potassium sulfate is preferably from about 1:1 to about 4A, more preferably from about 2:1 to about 3A, for the desired combination of exotherm stability, low wash water hardness, and 45 low viscosity.

The Cl,-C,, alkylbenzene sulfonate, cumene sulfonate, magnesium sulfate and sodium or potassium sulfate together should represent from about 12% to about 30%, preferably from about 14% to about 25%, by weight of the composition to provide sufficient dispersing and suspending agents. 50 The weight ratio of diperoxyacid particles to magnesium sulfate should also be less than about 3:11, preferably less than about 2.5A, for best exotherm stability.

The bleaching compositions of the present invention can, of course, be employed by them selves as bleaching agents. However, such compositions will more commonly be used as one element of a total bleaching or laundering composition. 55 Bleaching compositions herein can contain any of the optional ingredients known for use in such compositions.

The compositions herein can contain minor amounts, generally less than about 5%, preferably less than about 2%, most preferably less than about 1%, by weight, of other synthetic surfac tants, such as other anionic, nonionic, cationic and zwitterionic surfactants, or mixtures thereof. 60 known in the art. However, such additional surfactants, particularly nonionic and cationic surfac tants, have been found to increase viscosity and to cause phase separation when used at higher levels, and thus are not preferred for use herein. Preferably, the compositions are substantially free of such other surfactants.

Since the peroxyacid compounds used in the compositions of the present invention are subject 65 3 GB2188654A 3 to the loss of available oxygen when contacted by heavy metals, it is desirable to include a chelating agent in the compositions. Such agents are preferably present in an amount ranging from 0.005% to about 1.0% by weight of the composition. The chelating agent can be any of the well-known agents, including those described in U.S. Patent 3,442,937, issued May 6, 1969 to Sennewald et al., U.S. Patent 2,838,459, issued July 10, 1958 to Sprout, Jr., and U.S. 5 Patent 3,192,255, issued June 29, 1965 to Cann. Preferred chelating agents are picolinic acid and dipicolinic acid.

Bleaching compositions of the present invention are utilized by adding them to water in an amount sufficient to provide from about 1.0 ppm to 100 ppm available oxygen in solution.

Generally, this amounts to about 0.01% to 0.4% by weight of composition in solution. Fabrics 10 to be bleached are then contacted with such aqueous bleaching solutions.

The compositions of the present invention can also be used in combination with conventional fabric laundering detergent compositions. Such compositions can contain standard detergent ingredients, such as the surfactants and builders described in U.S. Patent 4,100,095, Hutchins et al., issued July 11, 1978, incorporated herein by reference. Preferred detergent compositions are 15 described in U.S. Patent 4,561,998, Wertz, et al., issued December 31, 1985, and U.S. Patent 4,507,219, Hughes, issued March 26, 1985, both incorporated herein by reference.

Preferably, detergent compositions formulated for use with bleaching compositions herein have a pH of from about 9 to about 12, preferably from about 9.5 to about 11.5, more preferably from about 10 to about 11. They preferably contain from about 2% to about 15%, more 20 preferably from about 4% to about 10%, by weight, of monoethanolamine. The combination of such an alkaline composition with a bleaching composition herein preferably delivers a wash water pH of from about 7.8 to about 9, preferably from about 7.9 to about 8.5, which is desired for good bleaching performance, a minimum of fabric yellowing, and a minimum of bleach decomposition by the monoethanolamine. 25 The following examples illustrate the compositions of the present invention.

All parts, percentages and ratios used herein are by weight unless otherwise specified.

Example 1

The following composition was prepared by high shear mixing of the components in an 30 Eppenbach mixer while in an ice bath. The DPDA and water were added to the mixer before turning the mixer on. The suds suppessor was added to minimize foaming while mixing and to minimize air entrapment in the finish composition. The other components were added in the order listed at the indicated times after turning on the mixer.

35 Component Grams Wt. Time 1, 1 2-Diperoxydodecanedioic 10,821.6 18.0 0 acid (DPDA) (26.68% active slurry) Water (additional) 1896 11.8 0 n_ Suds suppressor 12.8 0.08 1 min.

C, linear alkylbenzene 417.8 2.5 3 min.

suifonic acid (96% active) Sodium cumene sulfonate 463.4 1.45 3 min.

(50% active) 45 Dipiocolinic acid 1.6 0.01 3 min.

Sodium sulfate 641.6 4.0 1 hr.25 min.

Magnesium sulfate 1684.2 10.5 2 hr. 10 min.

Sodium hydroxide (50% 104 0.32 3 hr. 10 min.

active) 50 Balance primarily water.

After 3 hr. 30 min., the pH of the composition was determined to be 3.20 at 20'C. After 4 hr. 10 min., the pH was again determined to be 3.20 at 20'C and the mixer was turned off.

The composition was a stable suspension of the ingredients. It has a viscosity of about 350 cps 55 at about 20T. The DPDA had an average particle size of about 2-5 microns.

The above describes the preferred process for making the composition since high shear mixing of the components in an ice bath, their order of addition and the approximate times of addition have all been found to be important to obtain the desired physical stability.

After 9 days, there still was no physical separation of the composition. A 951 gram sample 60 of the composition was removed from the bottom and analyzed. It contained 18.29% DPDA and 10.81% magnesium sulfate. Since the target composition was 18.0% DPDA, chemical stability was very good.

After 11 days, about 48 grams of water were removed from the bottom of the composition.

Since this represents only about 0.3% of the composition, physical stability was very good. 65 4 GB2188654A 4 After 18 days, the original composition was transferred, along with 5 other samples of similar composition and preparation, to a 55 gallon drum and mixed by hand. The mixture was analyzed to contain 18.29% DPIDA. It had a viscosity of about 350 cps, a density of 1.187 g/mi, and a pH of 3. 20, all measured at 2WC. The next day, samples of the mixture were placed in storage at 40OF (4.44OC), 50'F (10'C), 70OF (21.1OC), 90OF (32.2Q and 100'F (37. 8'C). 5 After 17 days, the samples had very good physical and chemical stability, as indicate below.

Physical Stability 40OF - OK. Very slight clear aqueous layer on top.

50OF - OK. No separation. 10 70OF - OK. No separation. 90OF - OK. Less than about 2% clear aqueous layer on bottom. 100OF - Less than about 5% clear aqueous layer on bottom.

Chemical Stability 15 50OF - 18.25% DPIDA 70OF - 18.21 % DPIDA 90OF 18.28% DPIDA The above composition is preferably used in combination with the following detergent compo- sition. The detergent composition was prepared by adding the following components to a mixing 20 tank in the order listed with continuous mixing.

It GB2188654A 5 Wt. % Wt. % Components Assay Product Stock Sodium C 14-15 alky poly- 5 ethoxylate (2.25) sulfate 48.8 11.3 23.2 1 C 13 linear alkylbenzene sulfonic acid 96.0 8.0 8.33 10 Sodium diethylenetriamine pentaacetate 41.0 0.35 0.7 Propylene glycol 100.0 10.5 10.5 15 Monoethanolamine 100.0 5.0 3.0 Brightener mix 100.0 - 6.21 2 C 12-13 alcohol polyethoxy- 20 late (6.5) 100.0 9.0 7.0 Ethanol 92.0 10.48 7.3 Potassium hydroxide 45.0 2.48 5.51 25 Sodium hydroxide 50.0 2.94 5.88 Boric Acid 100.0 1.25 1.25 Water - 5.65 30 Sodium 2-dodecenyl succinate 80.0 5.53 6.9 C 12-14 fatty acid 100.0 3.5 3.5 35 Citric acid 50.0 4.0 8.0 Calcium formate 10.0 0.12 1.2 TEPA-E 15-18 80.0 3.0 3.75 40 pH trim to 10.5 - - - Protease enzyme (2.0 AU/g) 100.0 1.16 1.16 Amylase enzyme 45 (375 AM. U/g) 100.0 0.16 0.16 Perfume 100.0 0.25 0.25 Dye 100.0 0.08 0.08 50 Water - to 100% 3.25 55 Paste also contains 16.2% ethanol and 35% water.

2Contains 32.2% monoethanolamine, 32.2% water, 32.2% C12-,3 alcohol polyethoxylate (6.5), and 3.36% of brightener.

Alcohol and monoethoxylated alcohol removed.

Tetraethylene pentaimine ethoylated with 15-18 moles (avg.) of ethylene oxide at each 60 hydrogen site.

The compositions are preferably used in a volume ratio of detergent composition to liquid bleach of about 5.5A. The detergent composition is designed for a usage level of about 0.55 cups in a typical U.S. laundering process. This delivers a concentration of product in the wash water of about 0.22% by weight. Usage of about 0. 1 cups (i.e., about 25 mi) of the liquid 65 6 GB2188654A 6 bleach would deliver about 10 ppm of available oxygen to the wash water. The detergent composition and liquid bleach are preferably simultaneously codispensed from a dual compart ment bottle at a volume ratio of detergent to bleach of about 5.5A.

The mixture of the succinate and fatty acid builders in the above detergent composition is preferred because it causes less fabric yellowing and measuring cup residue than all fatty acid 5 formula when used with the above liquid bleach.

Example 11

Other compositions of the present invention, which can be prepared as in Example 1, are as follows: 10 Wt.% Components A B c D 1,12-Diperoxydodecanedioic 12.5 - 25.0 21.0 15 acid 1,9-Diperoxyazelaic acid - 15.0 - - Water 73.0 63.0 56.0 65.0 20 c 13 linear alkylbenzene 4.0 3.0 4.0 - sulfonic acid C 11.4 linear alkylbenzene - - - 3.0 25 sulfonic acid Sodium cumene sulfonate - 2.0 - - Magnesium sulfate 6.6 13.0 10.5 9.2 30 Sodium sulfate 3.1 - 2.5 - Potassium sulfate - - 1.0 35 Suds suppressor - 0.1 0.02 0.02 Dipicolinic acid 0.01 0.02 0.01 0.01 Sodium hydroxide to pH: 3.8 3.2 3.35 3.25 40 Viscosity (cps at 20OC) 450 900 Average particle size about 2-5 microns, after preparation. 45 Within the range of 50-1000.

50 Example fit

After storage of an about 22.3 kg sample of the liquid bleach mixture of Example 1 for about 8 months at about 20'C, a clear aqueous layer (about 6 kg) was removed from the bottom of the sample and the remainder was analyzed to contain the following:

7 GB2188654A 7 Components WtA 1,12-Diperoxydodecanedioic acid MPDA) 16.3 5 Water 57.0 Suds suppressor 0. 11 C 13 linear alkylbenze 10 sulfonic acid 3.4 Sodium cumene sulfonate 1.8 Dipicolinic acid 0.01 15 Sodium sulfate 3.5 Magnesium sulfate 9.2 Miscellaneous balance 20 The composition had a viscosity of about 850 cps, measured at 20'C. An additional 6.4 parts of sodium cumene sulfonate (50% active) was added to 100 parts of the composition to reduce its viscosity to about 240 cps at 20'C. This composition had a pH of about 2.6. Its pH was 25 adjusted to about 3.15 by adding a 50% solution of sodium hydroxide, resulting in a finished liquid bleach containing about 15.5% DPIDA.

The above liquid bleach composition is preferably used in combination with the following liquid detergent composition, which was prepared by adding the components to a mixing tank in the order listed with continuous mixing. 30 8 GB2188654A 8 Wt. Wt.

Components Assay Product Stock c 13 linear alkylbenzene 1 5 sulfonic acid 45.0 7.87 17.49 Sodium C 14-15 alkyl poly- 2 ethoxylate (2.25) sulfate 48.4 11.86 24.51 10 Propylene glycol 100.0 8.38 3.53 Sodium diethylenetriamine pentaacetate 41.0 0.30 0.73 Brightener mix 100.0 - 6.70 3 15 Monoethanolamine 100.0 4.5 2.50 c 12-13 alcohol polyethoxy- 20 late (6.5) 100.0 4.93 2.93 Ethanol 92.0 3.94 - Sodium hydroxide 50.0 4.19 5.38 25 Potassium hydroxide 45.0 1.18 2.62 c 12-14 fatty acid 100.0 9.86 9.86 Citric acid 50.0 3.94 7.88 30 Calcium formate 10.0 0.12 1.20 Sodium formate 30.0 0.86 2.77 c 12 alkyltrimethylammonium 35 chloride 37.0 0.6 1.62 TEPA-E 15-18 80.0 1.97 2.46 pH trim to 10.5 40 Protease enzyme (2.0 AU/g) 100.0 0.74 0.74 Amylase enzyme (375 AM. Ulg) 100.0 0.16 0.16 Dye 100.0 0.08 0.08 45 Perfume 100.0 0.25 0.25 Water - to 100% 6.59 50 Paste also contains 1.4% sodium hydroxide, 8.44% monoethanola mine, 25% propylene glycol, and 20.16% water.

2Paste also contains 16.2% ethanol, 5.12% sodium hydroxide, and 30.3% water.

3Contains 7.46% monoethanolamine, 29.82% CU-13 alcohol polyethoxylate (6. 5), 59.65% water, 55 and 3.07% brightener.

Alcohol and monoethoxylated alcohol removed.

Tetraethylene pentaimine ethoylated with 15-18 moles (avg.) of ethylene oxide at each hydrogen site.

6G The compositions are preferably used in a volume ratio of detergent composition to liquid 60 bleach of about 4A. The detergent composition is designed for a usage level of about 0.5 cups in a tyical U.S. laundering process. This delivers a concentration of product in the wash water of about 0.2% by weight. Usage of about 0.125 cups (i.e., about 30 mi) of the liquid bleach would deliver about 10 ppm of available oxygen to the 'wash water. The detergent composition and liquid bleqch are preferably simultaneously codispensed from a single dosing, dual compartment 65 9 GB2188654A 9 cup at a volume ratio of detergent to bleach of about 4: 1.

Claims (14)

1. A stable liquid bleach composition comprising, by weight:

(a) from about 10% to about 25% of water-insoluble diperoxyacid particles of the formula 5 HOOOC(CH2)nCOO0H, wherein n is from about 7 to about 14, said particles having an average size if from about 0.5 to about 15 microns; (b) from about 2% to about 6%, on an acid basis, of a C111C13 linear alkylbenzene sulfonate surfactant; (c) from about 0% to about 8%, on an acid basis, of cumene sulfonate; 10 (d) from about 5% to about 15% of magnesium sulfate; (e) from 0% to about 7% sodium or potassium sulfate; and (f) from about 40% to about 78% water said composition containing from about 3% to about 14% of (b) and (c), from about 5% to about 16% of (d) and (e), and from about 12% to about 30% of (b), (c), (d) and (e); the weight 15 ratio of (a) to (d) being less than about 3:1; and said composition having a pH of from about 2 to about 4.5 and a viscosity of from about 50 to about 1000 cps at 2WC.

2. The composition of Claim 1 wherein the diperoxyacid is 1,12diperoxydodecanedioic acid.

3. The composition of Claim 1 wherein the diperoxyacid particles have an average size of from about 0.5 to about 10 microns. 20

4. The composition of Claim 1 wherein (b) is a C13 linear alkylbenzene sulfonate.

5. The composition of Claim 1 wherein the composition has a viscosity of from about 500 cps at 2WC.

6. The composition of Claim 2 wherein (b) is a C13 linear alkylbenzene sulfonate.

7. The composition of Claim 6 comprising from about 2% to about 4% Of C,3 linear alkylben- 25 zene sulfate and from about 1% to about 6% of cumene sulfonate.

8. The composition of Claim comprising from about 8% to about 12% of magnesium sulfate from about 2% to about 6% of sodium sulfate.

9. The composition of Claim 8 comprising from about 14% to about 20% of the 1,12- diperoxydodecanedioic acid. 30

10. The composition of Claim 9 having a viscosity of from about 100 to about 350 cps at 200C.

11. The composition of Claims 10 having a pH of from about 3 to about 3.5 at 2WC.

12. The composition of Claim 1 comprising from about 1% to about 6% of cumene sulfon ate. 35

13. The composition of Claim 12 having a viscosity of from about 100 to about 350 cps at 200C.

14. The composition of Claim 13 comprising from about 14% to about 20% of 1,12 diperoxydodecanedioic acid.

Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd, Dd 8991685, 1987.

Published at The Patent Office, 25 Southampton Buildings, London, WC2A 1 AY, from which copies may be obtained.