WO1992020776A1

WO1992020776A1 - Liquid hand soap composition

Info

Publication number: WO1992020776A1
Application number: PCT/US1992/003631
Authority: WO
Inventors: Eftichios Van Vlahakis
Original assignee: Eftichios Van Vlahakis
Priority date: 1991-05-15
Filing date: 1992-04-29
Publication date: 1992-11-26
Also published as: AU1991792A

Abstract

A non-gelling, liquid soap composition made from ground bar soap particles of approximately 1/4 inch in diameter, water and a nonionic surfactant such as nonylphenol. This liquid soap composition will not gel, even when the soap particles are tallow and coconut based. Five parts per million of a household bleach may be added as a disinfectant. Other additives, such as cocamide DEA, sodium lauryl sulfate and sodium xylene sulfonate, enhance the properties of the liquid soap composition.

Description

LIQUID HAND 80AP COMPOSITION

DESCRIPTION

Technical Field

The invention is directed to a liquid soap composition, especially one suited for use as a hand soap. In particular, the invention is a liquid hand soap composition that is made from a raw material obtained by grinding used bar soap into small pieces. Background Of The Invention

Bar soaps are extremely popular for use at bathroom sinks for cleansing hands. Such bar soaps are also widely used during bathing near bathtubs and shower stalls. After a period of time, these bar soaps are reduced in size to a point where they are no longer easily usable. The resulting small soap pieces are discarded.

Small soap pieces also become available from the rooms of hotel guests. Each small bar soap supplied by the hotel is individually wrapped. Frequently, this bar soap is collected by room attendants after only one use, and this once-used bar soap is then discarded.

Liquid hand soaps have become increasingly popular over recent years, and this may be attributable to certain advantages over bar soaps. First, liquid hand soaps are contained in dispensers with mechanical pumps. The liquid soap is dispensed from these pumps into one of the hands of the user. As a result, the liquid soap never contacts the sink upon which its dispenser rests. In contrast, bar soaps are typically wetted during use. The bar soap is then placed onto the sink, countertop or soap dish in which it is stored, resulting in an unsightly film or *soap scum.* Attempts have been made to reconcile the waste resulting in the discarding of small pieces of bar soaps with the popularity of liquid hand soaps. Particularly, the Applicant is aware of and participated in prior attempts to manufacture a liquid hand soap from in excess of 2 percent (wt.) ground bar soap. At less than 2 percent, gelation does not occur. The attempts at in excess of 2 percent (wt.) ground bar soap, however, have been unsuccessful as a result of the formation of an undesirable gel in the liquid soap formulation. Prior art generally relevant to this field includes several United States patents. These patents include U.S. Patent Nos. 4,035,122, issued to Cavanaugh on July 12, 1977, and entitled "Soap Saving Device* 4,252,665, issued to Casey et al. on February 24, 1981, and entitled Disinfectant Cleaning Compositions"; 4,257,907, issued to Langguth et al. on March 24, 1981, and entitled "Disinfectant Cleaning Compositions"; 4,344,529, issued to Ibarzabal on August 17, 1982, an entitled "Combined Soap Holder And Press"; 4,387,040, issued to Straw on June 7, 1983, and entitled "Liqui Toilet Soap"; 4,518,517, issued to Eigen et al. on Ma 21, 1985, and entitled "Non-Antimicrobial Deodorant Cleansing Composition"; 4,738,987, issued to Mattson et al. on April 19, 1988, and entitled "Composition For Skin Care"; and 4,806,269, issued to Shimizu on February 21, 1989, and entitled "Waste Oil Processing Substance."

U.S. Patent No. 4,035,122 discloses a device which compresses small soap pieces and reforms those pieces into a bar of a desired configuration. This patent does not appear to disclose liquid soap formulations.

U.S. Patent Nos. 4,252,665 and 4,257,907 are both assigned to a common assignee and are directed to aqueous cleaning compositions comprising parachlorophenol, an alkali metal salt, a surfactant and a detergency boosting acrylic copolymer. These compositions are said to have germicidal effectiveness. These disclosures do not, however, relate to a liquid soap formulation formed from ground soap pieces.

U.S. Patent No. 4,344,529 discloses a combined soap holder and soap press. The invention described in this patent combines remnant, small soap pieces with a new bar soap. It does not relate to liquid soap formulations.

U.S. Patent No. 4,387,040 discloses a stable liquid toilet soap. It includes both a potassium soap and a viscosity controlling composition comprising coconut diethanolamide and sodium sulfate. This patent does not, however, disclose the use of solid soap pieces in the manufacture of a liquid soap composition.

U.S. Patent No. 4,518,517 discloses the use of "soap chips" and "detergent chips" in its Examples 5 and 6. These examples are not, however, directed to liquid soap compositions, but solid soap and detergent bars. Examples 1 through 4 are directed to liquid detergents, but it does not appear that these liquid detergents are made from solid soap particles or chips. U.S. Patent No. 4,738,987 discloses a composition for skin care that is the product of a homogeneous dispersion of water, soap, an alkali metal silicate and sulfonated castor oil. The soap ingredient is in a solid form, but is powdered or finely granulated to facilitate dispersion. Tallow and coconut soaps are among those which may be used, as disclosed at column 3, lines 15-26. Nonylphenol is not a component of any of these formulations.

Finally, U.S. Patent No. 4,806,269 discloses a waste oil processing substance capable of converting waste cooking oil into soap. This soap can be used for washing purposes.

fl__mm»τv n The nvention

In its broadest form, the invention is a liquid soap composition that comprises a ground bar soap and a non-ionic surfactant, preferably nonylphenol. It has been found that nonylphenol, when blended with soap particles of about 1/4 inch in diameter or less, will prevent the formation of gels in liquid hand soaps that are made from ground pieces of tallow and coconut bar soaps. Suitable ground bar soaps for use in the invention include those having a 70 percent or less tallow content and a 30 percent or more coconut content. Five parts per million of a household bleach may be added as a disinfectant.

Various additives may be added to the liquid soap solution to enhance its properties. Thus, a preferred liquid soap composition in accordance with the invention includes 5 parts of a ground bar soap, 85.8 parts water, 1.7 parts nonylphenol, 2.5 parts cocamide DEA, 2.5 parts sodium lauryl sulfate and 2.5 parts sodium xylene sulfonate.

This invention provides a new and beneficial use for the small soap pieces from households and hotels that have, until now, been discarded. It provides the solution to the problem of gel formation in prior liquid soaps made with small bar soap pieces.

Detailed Description Of The Preferred F™*"^ ™**"^

An important raw material for use with this invention is the bar soap that is normally used once in hotels and then discarded. Any kind of bar soap will be suitable for the invention, including the commonly used bar soaps having a 70-80 percent tallow content and a 20- 30 percent coconut content. This bar soap may be ground in a ball mill, or a similar comminuting device, to a diameter of 1/4 inch or less. Most preferred for the invention are bar soaps that have a tallow content of 70 percent and a coconut content of 30 percent. Thus, to the extent that the bar soaps used in this invention have a tallow content in excess of 70 percent, additional liquid or solid coconut- based soap should be added to increase the coconut content of the soap component to at least 30 percent, and to decrease the tallow content of the soap component to a level not exceeding 70 percent.

Preferably, one should not use a tallow content as high as 80 percent. It has been found that when the tallow content of the soap component is as high as 80 percent, the liquid soap composition resulting is not stable. With an 80 percent tallow content for the soap component and with the soap component of the liquid soap composition at 5 percent (wt.), the liquid soap composition gels after two weeks.

The most preferred tallow and coco ranges for the soap component of the liquid soap composition are between 50-70 percent tallow soap and 30-50 percent coco soap.

An additional essential ingredient is a non- ionic surfactant, such as a nonylphenol. The nonylphenol preferred for this invention is believed to include nine moles of an ethylene oxide polyethoxylate, and is commercially available from Union Carbide Corporation under the brand name Tergitol™ NP-9. Tergitol NP-9 is a nonylphenol polyethylene glycol ether. This nonylphenol, as a percentage of the weight of the final liquid soap, should amount to at least 1.7 percent (wt) . It is believed that equivalent performance may be obtained through the use of closely adjacent homologs, such as octylphenols, heptylphenols or decylphenols.

Nonylphenols are preferred, however, as they are both more readily available and environmentally acceptable.

Ingredients which have been found to provide improved cleaning and better foam stability include cocamide DEA, sodium lauryl sulfate and sodium xylene sulfonate. A relatively small amount of a household bleach kills bacteria that may be present in the used soap particles and the water. Household bleach, as widely available in grocery and discount stores, is actually a 6.57 percent bleach in water solution. A 5 percent bleach in water solution is adequate for use in the invention, although no deleterious effects will occur as a result of the use of household bleach in lieu of and in the same amounts as this 5 percent solution. Although bleach is the preferred disinfectant, any commercial, non-toxic disinfectant is acceptable. An additional advantage of liquid soap compositions in accordance with the present invention is that they are biodegradable.

Formulation 1 The solids component of a suitable "recycled* liquid soap composition in accordance with the invention is made from the following ingredients:

30 parts (wt.) granulated bar soap (70 tallow/30 coco) 5 to 10 parts (wt.) nonylphenol

10 to 15 parts (wt.) cocamide DEA 10 to 15 parts (wt.) sodium lauryl sulfate 10 to 15 parts (wt.) sodium xylene sulfonate 5 parts per million (vol.) household bleach Ten to twenty parts (wt.) of this solids component is blended in 80 to 90 parts (wt.) water, thereby forming the liquid soap composition of the invention. In weight percentages, one of the preferred compositions which is within the scope of the above- described composition has a content of about 5 parts ground bar soap, 85.8 parts water, 1.7 parts nonylphenol (NP-9) , 2.5 parts cocamide DEA, 2.5 parts sodium lauryl sulfate and 2.5 parts sodium xylene sulfonate. About 5 parts per million (vol.) household bleach is also added to this blend.

No special processing or heating of these ingredients is necessary. Rather, the bar soap is comminuted to the proper size and the remaining ingredients are blended with the soap particles in a mixing tank. A commercial blender is used to thoroughly mix the contents of the tank. The water used may be at room temperature, i.e., about 75^* Fahrenheit.

It has been found that nonylphenol, when blended with soap particles of about 1/4 inch or less in diameter, will prevent the formation of gels in liquid hand soaps made from ground pieces of tallow and coconut bar soaps.

It has been found through testing that the ground and liquid soap content of the present invention can reach 7 percent, with a stable liquid soap composition being formed. Preliminary testing has also tentatively shown that the ground and/or liquid soap content of the present invention can reach 10 percent, with a stable liquid soap composition believed to be formed. As a percentage of the weight of the liquid soap composition, the soap content (i.e., weight of ground bar soap and/or liquid soap) should be from 3-10 percent by weight. Amounts of ground and/or liquid soap at the higher ends of 3-10 percent range are unnecessary for the preparation of a suitable liquid hand soap, and merely add to the expense of the liquid hand soap.

Additional liquid soap compositions in accordance with the invention may be made as follows: Formulation 2 .total soap content 6 percent. Ca. 82 parts (wt.) water (QS 100) 0.01 parts (wt.) 5 percent bleach 4.5 parts (wt.) ground bar soap (80/20) 4.5 parts (wt.) Ninol 11 CM

4.5 parts (wt.) NP-9 0.5 parts (wt.) potpourri fragrance 0.5 parts (wt.) herbal fragrance 0.5 parts (wt.) morpholine 1.5 parts (wt.) liquid cocosoap (40 percent liquid) 1.5 parts (wt.) sodium metasilicate

Ninol 11 CM is a product of the Stepan Chemical Company.

Tergitol NP-9 is a nonylphenol polyethylene glycol ether that is a product of the

Union Carbide Corporation.

The manufacture of this formulation is like that of Formulation 1, with a few exceptions. The water, bleach and ground soap are all pre-blended for approximately 10 minutes in a mixing tank to form a slurry. The remaining ingredients are then added to the mixing tank and blended until a solution of uniform texture and color is achieved. An all-purpose cleaner results from this liquid soap formulation.

Formulation 3 (total soap content 4.5 percent.

Ca. 75.5 parts (wt.) water (QS 100) 0.01 parts (wt.) 5 percent bleach

3.0 parts (wt.) ground bar soap (80/20)

1.5 parts (wt.) ethylene diamine tetra acetate

8.0 parts (wt.) butyl cellosolve

2.5 parts (wt.) NP-9 7.0 parts (wt.) caustic soda (50 percent)

1.5 parts (wt.) liquid cocosoap (40 percent solids content)

1.0 parts (wt.) sodium metasilicate The steps in the manufacture of Formulation 3 are identical to the steps in the manufacture of Formulation 2. A heavy duty cleaner results from this liquid soap formulation.

Formulation 4 (total soap content 7.0 percent) Ca. 79 parts (wt.) water (QS 100) 0.01 parts (wt.) 5 percent bleach 4.0 parts (wt.) ground bar soap (70/30) 3.0 parts (Wt.) Steol CS-460

3.0 parts (wt.) NP-9 3.0 parts (wt.) liquid cocosoap (40 percent solids content) 1.5 parts (wt.) Acrysol ICS-1 2.5 parts (wt.) Ninol 11 CM

4.0 parts (wt.) sodium xylene sulfonate

Steol CS-460 is a 60 percent (cone.) sodium salt of a coconut ether sulfate ammonium salt.

Acrysol ICS-I is a thickener or stabilizer from the Rohm and Haas Company. The steps in the manufacture of Formulation 4 are identical to the steps in the manufacture of Formulation 2. Formulation 4 is suitable for use as a liquid hand soap. The Acrysol ICS-I acts as both a thickener and stabilizer, and also imparts a pleasant "milky* look to the finished liquid soap composition.

While the specific embodiments have been illustrated and described, numerous modifications come to mind without markedly departing from the spirit of the invention. The scope of protection is, thus, only intended to be limited by the scope of the accompanying claims.

Claims

CLAIMS What I claim is:

1. A liquid soap composition, comprising: a. 5 parts (wt.) of a ground bar soap; b. 85.8 parts (wt.) water; c. 1.7 parts (wt.) of a non-ionic surfactant; d. 2.5 parts (wt.) cocamide DEA; e. 2.5 parts (wt.) sodium lauryl sulfate; and f. 2.5 parts (wt.) sodium xylene sulfonate.

2. The liquid soap composition of Claim 1, wherein said ground bar soap has a 70 percent or less tallow content and a 30 percent or more coconut content.

3. The liquid soap composition of Claim 1, wherein said non-ionic surfactant is nonylphenol.

4. The liquid soap composition of Claim 2, wherein said non-ionic surfactant is nonylphenol.

5. The liquid soap composition of Claim 1, further comprising at least 5 parts per million (vol.) bleach.

6. A liquid, non-gelling soap composition, comprising a ground bar soap and nonylphenol.

1. The liquid soap composition of Claim 6, wherein said ground bar soap has a seventy to 70-80 percent tallow content and a 20-30 percent coconut content.

8. The liquid soap composition of Claim 6, wherein said ground bar soap is present in an amount of from 3- 10 percent (wt.).

9. The liquid soap composition of Claim 7, wherein said ground bar soap is present in an amount of from 3- 10 percent (wt.).

10. The liquid soap composition of Claim 6, wherein said ground bar soap is present in an amount of from 3- 7 percent (wt.) .

11. A liquid soap composition comprising 10-20 percent by weight of a solid component, and 80-90 percent by weight of a liquid component, said solid component comprising: 30 parts by weight of a granulated bar soap;

5 to 10 parts by weight of a non-ionic surfactant;

10 to 15 parts cocamide DEA;

10 to 15 parts by weight sodium lauryl sulfate; and said liquid component comprising water, said liquid component also including a disinfectant in an amount of approximately five (5) ppm.

12. The liquid soap composition of Claim 11, wherein said granulated bar soap has a tallow content of 70 percent or less and a coconut content of 30 percent or more.

13. The liquid soap composition of Claim 11, wherein said non-ionic surfactant is nonylphenol.

14. The liquid soap composition of Claim 12, wherein said non-ionic surfactant is nonylphenol.

15. A liquid, non-gelling soap composition including a soap component obtained from ground bar soap, said soap component having a tallow content of 50-70 percent and a coconut content of 30-50 percent.

16. The liquid, non-gelling soap composition of Claim 15, wherein said composition further comprises nonylphenol.

17. The liquid, non-gelling soap composition of Claim 16, wherein said nonylphenol is present in an amount not less than 1.7 percent (wt.).