WO1994001522A1

WO1994001522A1 - 1,1-dichloro-1-fluoroethane based dry cleaning composition

Info

Publication number: WO1994001522A1
Application number: PCT/US1993/005988
Authority: WO
Inventors: Rajat Subhra Basu; Kane David Cook
Original assignee: Allied-Signal Inc.
Priority date: 1992-07-10
Filing date: 1993-06-22
Publication date: 1994-01-20
Also published as: MX9304017A; CN1081203A; AU4412293A

Abstract

Compositions comprising 1,1-dichloro-1-fluoroethane and at least one surfactant selected from the group consisting of anionic surfactant and nonionic surfactant are stable and have utility as dry cleaning solvents. The compositions remove soils and prevent redeposition of soils.

Description

1 .1 -DICHLORO-1 -FLUOROETHANE BASED DRY CLEANING COMPOSITION

BACKGROUND OF THE INVENTION

This invention relates to dry cleaning compositions consisting essentially of 1 , 1 -dichloro-1 -fluoroethane and at least one surfactant selected from the group consisting of anionic surfactant and nonionic surfactant.

Dry cleaning involves running soiled garments through a solvent. Generally, fabrics which should not be washed in water such as silk, wool, leather, and fine fabric have to be dry-cleaned. Other types of clothing are also dry-cleaned for improved cleaning. Typical stains on such garments include water-soluble stains such as food stains which are not readily removed by organic solvents. It has been found that water-soluble stains in addition to solvent-soluble stains can be removed in a dry-cleaning process if the dry cleaning composition contains a surfactant.

Typical dry cleaning equipment includes a washer having a circulating line and pump. The solvent passes through the washer and then out through a filter before returning to the washer. The filter removes the soil and clarifies the solvent so that it can be re-used. In a batch dry-cleaning system for example, soiled garments are tumbled through the solvent; the solvent is then filtered and can be re-used.

A commonly used dry cleaning solvent is perchloroethylene which has a boiling point of about 121 °C. This compound is disadvantageous for use as a dry cleaning solvent because it is toxic.

Chlorofluorocarbon solvents, such as trichlorotrifluoroethane, have attained widespread use in recent years as effective, nontoxic, and nonflammable agents useful in various solvent applications including dry cleaning. One isomer of trichlorotrifluoroethane is

1 ,1 ,2-trichloro-1 ,2,2-trifluoroethane (known in the art as CFC-1 13). CFC-1 13 has a boiling point of about 47 °C and has been found to have satisfactory solvent power for greases, oils, waxes, and the like.

Although chlorine is known to contribute to the solvency capability of a compound, fully halogenated chlorofluorocarbons and hydrochlorocarbons are suspected of causing environmental problems in connection with the earth's protective ozone layer. Thus, the art is seeking new compounds which do not contribute to environmental problems but yet provide the solvency properties of CFC-1 13. From an environmental standpoint, hydrochlorofluorocarbons are of interest because they are considered to be more stratospherically safe than the currently used fully halogenated chlorofluorocarbons. Mathematical models have substantiated that hydrochlorofluorocarbons, such as 1 ,1-dichloro-1-fluoroethane (known in the art as HCFC-141b), will not adversely affect atmospheric chemistry, being a negligible contributor to ozone depletion and to green-house global warming in comparison to the fully halogenated species.

In any dry cleaning system, it is desirable to remove oily and solid soil, remove water-soluble soil, avoid redeposition of soil, and avoid shrinkage of any garment. It would also be desirable to have a dry cleaning composition which would not adversely affect atmospheric chemistry while removing soil, preventing soil redeposition, and avoiding garment shrinkage.

Kokai Patent Publication 139,861 , published June 1 , 1989, discloses a dry cleaning agent of 99 weight percent of an azeotropic composition of 67 weight percent 1 ,1-dichloro-2,2,2-trifluoroethane and 33 weight percent 1 ,1-dichloro-1-fluoroethane, and 1 weight percent sodium dodecyl benzene sulfonate. Unfortunately, the compatibility of an azeotropic composition of 1 ,1 - dichloro-2,2,2-trifluoroethane and 1 ,1-dichloro-1-fluoroethane with polymeric materials such as buttons is not as good as desired.

SUMMARY OF THE INVENTION

Our solution to the need in the art for dry cleaning compositions which would not adversely affect atmospheric chemistry while removing soil, preventing soil redeposition, and avoiding garment shrinkage is dry cleaning compositions consisting essentially of 1 ,1-dichloro-1-fluoroethane and at least one surfactant selected from the group consisting of anionic surfactant and nonionic surfactant. Preferably, the present dry cleaning compositions consist essentially of from about 96 to about 99.98 weight percent 1 ,1-dichloro-1 - fluoroethane and from about 0.02 to about 4 weight of at least one surfactant selected from the group consisting of anionic surfactant and nonionic surfactant.

DETAILED DESCRIPTION OF THE INVENTION

We have found a dry cleaning composition which not only will provide better cleaning efficiency compared with CFC-1 13 and perchloroethyiene but also will provide less redeposition of soil on garments. The present novel dry-cleaning compositions consist essentially of 1 ,1-dichloro-1-fluoroethane and at least one surfactant selected from the group consisting of anionic surfactant and nonionic surfactant.

Preferably, the novel compositions consist essentially of effective amounts of 1 ,1-dichloro-1-fluoroethane and at least one surfactant selected from the group consisting of anionic surfactant and nonionic surfactant. The term "effective amounts" as used herein means the amount of each component which upon combination with the other component, results in the formation of the present dry cleaning composition with its desirable cleaning properties and redeposition minimization properties. The present dry cleaning compositions are advantageous for the following reasons. Each component is a negligible contributor to ozone depletion. Also, the compositions will provide better cleaning efficiency compared with CFC-1 13 and better toxicity and compatibility to materials compared to perchloroethylene and also will provide less redeposition of soil on garments.

Preferably, a mixture of anionic and nonionic surfactants is used.

The preferred dry cleaning compositions are in the following Table I. In the Table I, the numerical ranges are understood to be prefaced by "about":

TABLE I

Examples of useful nonionic surfactants include alcohol polyethenoxylate; alkylphenol polyethylenoxylate; alkanolamide; ethylene oxide; propylene oxide; glycerγl ester; polyglyceryl ester; sorbitan ester; and tertiary acetylenic glycol. The preferred nonionic surfactant is tertiary acetylenic glycol.

Examples of useful anionic surfactants include alkγlbenzene sulfonate; alky I sulfate; alkγl polγoxγethyiene phosphate; alkylphenyl polγoxyethγlene phosphate; alpha-olefin sulfonate; dialkγl sulfosuccinate; lignin sulfonate; naphthalene sulfonate; and petroleum sulfonate. The preferred anionic surfactant is dialkyi sulfosuccinate.

Preferably, tertiary acetylenic glycol and dialkyi sulfosuccinate are used together in the present dry cleaning composition.

In one process embodiment of the invention, the compositions of the invention may be used to clean fabric by treating the fabric with the compositions in any manner well known to the art such as by tumbling the soiled garments through the present compositions and air drying them in conventional dry-cleaning machines.

The HCFC-141b, anionic surfactant, and nonionic surfactant components of the novel solvent compositions of the invention are known materials.

EXAMPLES 1-2

The following compositions are made with tertiary acetylenic glycol as the nonionic surfactant and dialkyi sulfosuccinate as the anionic surfactant. The components in Table II are in weight percent.

TABLE

EXAMPLES 3-4 AND COMPARATIVES A-D

This Example is a cleaning test of fabrics soiled with oils. A polycotton cloth was used as the testing fabric. Synthetic oil stain and oil dag (a mixture of graphite and mineral oil) were used as oily soil. Perchloroethylene and CFC- 1 13 were tested for comparative purposes. The dry cleaning composition of Example 1 is used for Examples 3 and 4.

The cleaning test results are shown in Tables III (oil stain) and IV (oil dag) below. In Tables III and IV, Comp stands for Comparative. In Tables III and IV, 1 means the best, 2 means better, 3 means good, and 4 means bad. The cleaning efficiency was gauged based on the degree of light absorption. The best solvent has a degree of light absorption which is close to that of the clean cloth. Note that the present composition will be equal to or superior than either CFC-1 13 or perchloroethylene as a dry cleaning composition.

TABLE

TABLE IV

EXAMPLES 5-6 AND COMPARATIVES E-H

These Examples are redeposition tests wherein clean fabrics were placed in a carbon black solution. The redeposition experiment was done as follows. An equal amount of each type of soil was placed in each of these solvent blends. Perchloroethylene and CFC-1 13 in combination with surfactants were tested. The dry cleaning composition of Example 1 and 2 are used for Examples 5 and 6. A piece of an inch square of clean polycotton cloth was dipped into the solvents for 5 minutes. During this period, a mechanical agitation was applied. The contaminated fabric was removed from the solvents at the end of 5 minutes and allowed to air dry. The difference in light absorption between the clean cloth and the washed ones was measured by a photometer.

The present 1 ,1-dichloro-1-fluoroethane based dry cleaning compositions perform equal to or better than compositions of CFC-1 13 and perchloroethylene with the same surfactants.

Claims

What is claimed is:

1. Compositions consisting essentially of from about 96 to about 99.98 weight percent 1 ,1 -dichloro-1 -fluoroethane and from about 0.02 to about 4 weight percent of at least one surfactant selected from the group consisting of anionic surfactant and nonionic surfactant.

2. The compositions of claim 1 wherein anionic surfactant is present.

3. The compositions of claim 1 wherein nonionic surfactant is present.

4. The compositions of claim 1 wherein a mixture of anionic surfactant and nonionic surfactant is present.

5. The compositions of claim 1 wherein said nonionic surfactant is selected from the group consisting of alcohol polyethenoxylate; alkylphenol poly ethylenoxy late ; alkanolamide; ethylene oxide; propylene oxide; glyceryl ester; polyglyceryl ester; sorbitan ester; and tertiary acetylenic glycol.

6. The compositions of claim 1 wherein said anionic surfactant is selected from the group consisting of alkylbenzene sulfonate; alkyl sulfate; alkyl polyoxyethylene phosphate; alkylphenyl polyoxyethylene phosphate; alpha-olefin sulfonate; dialkyi sulfosuccinate; lignin sulfonate; naphthalene sulfonate; and petroleum sulfonate.

7. The compositions of claim 1 consisting essentially of from about 97 to about 99.8 weight percent said 1 , 1 -dichloro-1 -fluoroethane, from about 0.1 to about 1 .5 weight percent of said anionic surfactant,, and from about 0.1 to about 1.5 weight percent of said nonionic surfactant.

8. The compositions of claim 1 consisting essentially of from about 97.6 to about 99.8 weight percent said 1 , 1-dichloro-1-fluoroethane, from about 0.1 to about 1.2 weight percent of said anionic surfactant, and from about 0.1 to about 1.2 weight percent of said nonionic surfactant.

9. The compositions of claim 1 consisting essentially of from about 98 to about 99.8 weight percent said 1 ,1-dichloro-1-fluoroethane, from about 0.1 to about 1 weight percent of said anionic surfactant, and from about 0.1 to about 1 weight percent of said nonionic surfactant.

10. The compositions of claim 1 wherein said anionic surfactant is dialkyi sulfosuccinate and said nonionic surfactant is tertiary acetylenic glycol.