CA2383709A1 - Non combustible nonaqueous compositions - Google Patents

Abstract

Non-aqueous cleaning compositions and methods, especially for dry cleaning textiles, utilise 0.5-80wt.% of at least one perfluorinated compound, 2-98wt.%
of a solvent naphta, mineral spirit or medium aliphatic hydrocarbon, and 1-98 wt.% glycol ether or glycol ether acefale.

Description

NON COMBUSTIBLE NONAQUEOUS COMPOSITIONS
Field of the Invention The present invention relates to compositions designed to replace perchloroethylene for dry-cleaning, and as an alternative to the low flash point replacement solvents for perchloroethylene. The invention provides methods for substantially raising the flash points of low flash point petroleum solvents currently in use in the dry cleaning industry. The invention renders the solvents nonflammable and non-combustible while retaining, indeed enhancing their ability to remove stains, grease, fatty acids, oil and soil, among other contaminants, from textiles, fabrics and garments normally encountered in the dry cleaning industry and uniforms, fabrics and garments normally encountered in the uniform rental business. The present invention also relates to degreaser formulations for use in removing grease and oil from equipment, machinery and the like. In addition, the present invention may also be used to separate and concentrate oil removed from garments by distillation, obviating the need to dispose of it as a perchloroethylene contaminated hazardous waste.
Background of the Invention Garments and other fabrics, including carpeting curtains, industrial uniforms etc. become soiled with stains, fatty acids and other contaminants which attach to dust attracted to the garment during the normal course of wear.
At present these garments are cleaned, primarily by drycleaning, using perchloroethylene which has no flash point. More recently other fluids for dry cleaning have emerged. These fluids, typically non-halogenated petroleum solvents require a new generation of machine equipped with oxygen sensors and/or nitrogen injection to prevent combustion or explosions in the equipment because of the fluids low flash point. These solvents are generically termed petroleum solvents. Most notably stoddard solvent, mineral spirits, Exxon Chemical Dry-cleaning Fluids DF2000 and Exxsol D 40, a product with trade name Drylene, and Shell Chemical Company's Shell Sol 142 HT. All have flash points below 150 degrees F, are flammable, and are therefore classified III A solvents by NFPA (National Fire Prevention Association) because of their propensity to combust or explode in dry cleaning equipment. Typically the ignition source for combustion is a static charge. Rarely, but sometimes, the ignition source is a cigarette lighter inadvertently left in a garment pocket. In Japan and China where stoddard solvent and mineral spirits are in common use fires and explosions in dry-cleaning equipment is a frequent occurrence.
The present invention enables use of these low flash point solvents by elevating their flash points to preclude flammability and combustibility classifications and risks.
Objects of the Present Invention It is the object of the present invention to provide compositions for commercial dry-cleaning of textiles and related articles with compositions having flash points exceeding 100°C by modifying the flash points of the flammable and combustible hydrocarbon solvents utilizing components with zero ozone depleting potential.
It is a further objective of the present invention to maintain the essential physical properties of the petroleum solvents to maintain their suitability as dry-cleaning fluids.
Still another objective of the present invention is to raise the vapor pressure of the solvents to accelerate garment drying while maintaining high solvent flash points.
Summar~r of the Invention The present invention relates to compositions and methods of removal of contaminants from textiles and related fabrics and garments and grease and oil from machinery and related equipment utilizing compositions which provide a high occupational safety threshold because of their high flash points, pose no significant risk to ground water, are environmentally compatible and which are substantially biodegradable. Compositions according to the present invention preferably are substantially non-toxic, substantially biodegradable liquids at room temperature or higher, are not hazardous air pollutants (HAP's), have insignificant VOC potential, have zero Ozone Depletion Potential (ODP) and are effective in removing substantial quantities of contaminants from fabrics and especially garments such as industrial uniforms and gloves.
Compositions according to the present invention avoid the use of perchloroethylene, mineral spirits or chlorinated fluorinated hydrocarbons (CFC's). The present compositions may be utilized as effective substitutes for perchloroethylene in commercial cleaning processes and as degreasers.
The present compositions have many of the favorable physical and chemical characteristics of perchloroethylene without the attendant unfavorable characteristics, most notably, the environmental incompatibility of perchloroethylene.
The present compositions present no groundwater threat because of their densities (7.51bs/gal to 8.2 lbs/gal), compared to perchloroethylene with a density of 13.47 lbs/gal. The present compositions may accommodate surfactants which may aid the removal of fatty acids, stains and other contaminants from fabrics, especially clothing. In addition, the present compositions are compatible with most, if not all, of the commercial fibers used in fabrics. Like perchloroethylene, the present compositions advantageously do not substantially change the shape or deform the underlying fibers of the cloth. The compositions impart, what is known in the vernacular of dry-cleaners, a nice hand (smooth feel) to the garments and they are generally stable during cleaning operations and at drying, separation and distillation temperatures.
Cleaning compositions are essentially non-aqueous and according to the present invention comprise:
(i) about to to about 98% by weight of a glycol ether and or glycol ether acetate;
(ii) about 2o to about 98o by weight of a solvent naphtha, mineral spirits, or medium aliphatic hydrocarbon;
and (iii) about 0.5o to about 80o by weight of at least one perfluoro compound.
The composition may further comprise a hydrofluoroether Alternatively, the essentially non-aqueous composition may comprise:
(i) about 1% to about 98o by weight of a glycol ether and or glycol ether acetate;

(ii) about 0.5o to about 80o by weight of at least one perfluoro compound.
(iii) about 2o to about 98% by weight of a solvent naphtha, mineral spirit, or medium aliphatic hydrocarbon; and (iiii) about 0.5% to about 80o by weight of a hydrofluoroether.
In yet another embodiment, the essentially nonaqueous composition may comprise (i) about to to about 98o by weight of a glycol ether or glycol ether acetate;
(ii) about 2% to about 98% by weight of a solvent naphtha, mineral spirit, or medium aliphatic hydrocarbon; and (iii) about 0.5o to about 80o by weight of a hydrofluoroether.
As defined herein ~~essentially nonaqueous" means that the composition contains less than about to of water.
Preferred amounts of glycol ethers for the present compositions range from about 1% to about 98o by weight, more preferably about 3o to about 60o by weight, even more preferably about 4% to about 40o by weight, even more preferably about 5% to about 15o by weight. Preferred amounts of the aliphatic hydrocarbon for use in the cleaning composition in the present invention range from about 2o to about 98o by weight, more preferably from about 30o to about 97o by weight, even more preferably from about 63o to about 95% by weight. The amount of perfluorocarbon compounds in the cleaning compositions according to the present invention preferably ranges from about 0.5o to about 80o by weight, more preferably from about 2o to about 60o by weight, more preferably from about 3% to about 40% by weight, even more preferably about 3o to about 30o by weight and even more preferably about 4o to about 25o by weight. Preferred amounts of hydrofluoroethers for use in the cleaning composition in the present invention preferably range from about 0.5% to about 80% by weight, more preferably from about 2% to about 60o by weight, even more preferably about 3o to about 30o by weight and even more preferably about 4% to about 25% by weight.
Compositions according to the present invention may optionally include at least one component selected from the group consisting of, for example, an antimicrobial agent, a fabric finishing agent, an anionic surfactant to facilitate incorporation of small quantities of water to assist in removal of water soluble stains from fabrics and garments, or mixtures thereof.
Compositions according to the present invention have densities which are generally less than that of water and are preferably biodegradable, preferably with BOD's of greater than about 20 ppm, more preferably greater than about 40 ppm.
The present compositions are particularly environmentally advantageous because they are readily biodegradable and they are lighter than water. As such, the present preferred compositions pose little, if any risk to contaminate groundwater.
The invention is further directed to methods for removing one or more contaminants from textiles, fabrics, garments, flexible and/or inflexible surfaces comprising applying the compositions of the present invention to said textiles, fabrics, garments or surfaces in amounts effective to remove said contaminants from said textiles, fabrics, garments or surfaces. Optionally, the contaminants removed from the garment which are initially present in a composition/contaminant mixture may separated from the cleaning composition by distillation and may be recovered or isolated. They often include oil and related hydrocarbons which may be used as fuel, thereby obviating the need to dispose of the distillation still bottom as hazardous waste.
Detailed Description of the Invention The following definitions will be used throughout the specification to define the present invention.
The term ~~contaminant(s)" shall be used to describe most substances which are not normally found in fabrics or other flexible and inflexible surfaces such as machinery and metal surfaces in their clean, uncontaminated state and are generally removed from fabrics or other surfaces during cleaning processes. Contaminants include but are not limited to fats, fatty acids, in particular, triglycerides and fatty acids, fat like substances, salts, food remnants, sweat, blood stains, soil, oil, grease and related lubricants and numerous other synthetic and natural or biological contaminants or lubricants which are normally not found on the surfaces and textiles to be cleaned according to the present invention. The most common contaminants which are removed by compositions according to the present invention include triglycerides, fatty acids and related fatty food contaminants and grease, oil and related lubricants. One of ordinary skill will recognize that the instant invention will be effective in removing a wide variety of surface contaminants; however, in many instances, depending upon the chemical nature of the contaminant, the present compositions may need to be modified within the teachings of the invention in order to maximize removal of a particular contaminant.
Examples of hydrofluoroether compounds include but are not limited to ethoxy-nonafluorobutane, ethyl perfluoroisobutyl ether, ethyl perfluorobutyl ether, methoxy-nonafluorobutane, methyl nonafluoroisobutyl ether, methyl nonafluorobutyl ether and their isomers.
The term perfluoro compounds is used in the present specification to describe compounds CnF2n+2,n-3 to 8.
The compositions of the present invention further comprise a hydrofluoroether/trans-1,2-dichloroethylene mixture. In one embodiment, it is an azeotropic mixture. In another embodiment, the ratio of hydrofluoroether:trans-1,2-dichloroethylene is from about 5:95 to about 95:5.
The term "glycol ether" and "glycol ether acetate"
are used throughout the specification to describe certain preferred components which are used in the compositions according to the present invention. Primarily, propylene glycol ethers and ether acetates and ethylene glycol ethers and ether acetates may be used. Exemplary glycol ethers for use in the present invention , include, without limitation ethylene and propylene glycol substituted ethers, such as propylene glycol t-butyl ether, ethylene glycol methyl ether, diethylene glycol methyl ether, diethylene glycol methyl ether, triethylene glycol methyl ether, ethylene glycol methyl ether, diethylene glycol ethyl ether, triethylene glycol ethyl ether, ethylene glycol n-propyl ether, diethylene glycol n-propyl ether, triethylene glycol n-propyl ether, ethylene glycol isopropyl ether, diethylene glycol isopropyl ether, triethylene glycol isopropyl ether, ethylene glycol n-propyl ether, diethylene glycol n-propyl ether, triethylene glycol n-propyl ether, ethylene glycol n-butyl ether, diethylene glycol n-butyl ether, trietheylene glycol n-butyl ether, propylene glycol methyl ether(PM), dipropylene glycol methyl ether, dipropylene glycol dimethyl ether, tripropylene glycol methyl ether, propylene glycol ethyl ether, dipropylene glycol ethyl ether, tripropylene glycol ethyl ether, propylene glycol n-propyl ether (PnP), dipropylene glycol n-propyl ether, propylene glycol n-propyl ether (PnP), dipropylene glycol n-propyl ether, propylene glycol isopropyl ether, dipropylene glycol isopropyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, , aromatic based-glycol ethers, ethylene glycol methyl ether acetate, diethylene glycol methyl ether acetate, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate and mixtures thereof. These compounds are available from a number of sources including Dow Chemical Corp. and Arco Chemical Company, among others. The inclusion of equivalents of these glycol ethers and glycol ether acetates are also contemplated by the present invention.
Preferred glycol ethers and glycol ether acetates for use in the present invention have relatively high vapor pressures and low boiling points to facilitate the rapid drying of fabrics and to accelerate distillation.
The terms "aliphatic hydrocarbon", "solvent naphtha", "mineral spirits", refers to paraffins, normal and iso, consisting of both open and branched chain structure. Naphtha -generic, loosely defined term refers to a range of light petroleum distillates.
Included in the naphtha classification are light crude naphtha (LCN) liquid distillation fractions with boiling range 32° to 100°C (90° to 175°F), and heavy crude naphtha with boiling range 163° to 218°C (325° to 425°F).
The following examples are provided to illustrate the present invention and should not be misunderstood to limit the scope of the present invention in any way.

EXAMPLES
The task was to prepare compositions which enhance the performance characteristics, from both a safety and performance point of view, of petroleum solvents, naphthas and mineral spirits, solvents which are presently used in dry-cleaning. In their present application they present a severe ignition and explosion hazard in use. Severe constraints are placed on siting of facilities using petroleum solvents because of the inherent fire hazard the storage and use of these low flash point solvents pose.
The following compositions were made and assessed for their ability to clean typical contaminants from textiles.
They were also evaluated for their solvent effect on typical textiles and fabrics used in industrial gloves and uniforms, and in normal dry-cleaning fabrics.
Each composition was tested using the Taggart Closed Test flash point method to assess its flammability or combustibility.
The following components were used in the following examples to produce compositions exemplary of the present invention. Dipropylene glycol dimethyl ether(DMM) was obtained from DOW Chemical Co., Midland, Michigan.
COVI-OX-T-70 is a mixed mixed tocopheral concentrate.
COVI-OX-T-70 was obtained from Henkel Chemical Co., Kankakee, Illinois. HFE-7100 and HFE-7200 are hydrofluoroethers.
HFE-7100, HFE-7200. All components designated PF are perfluoro compounds.PF-5070, PF-5058, PF-5060, PF-5070, PF-5052, PF-5056, and PF-5080 were obtained from the 3M
Company, St. Paul Minnesota. Stoddard solvent, mineral spirits and Shell Sol 142 HT were obtained from Shell Chemical Co., Houston, Texas, DF-2000 was obtained from Exxon Chemical Co., Houston Texas. DF-2000 and Shell Sol 142-HT are hydrotreated medium aliphatic hydrocarbon solvents.
In producing the compositions, the individual components may be added and stirred to provide a completely mixed product. In these examples, for the most part, the components were added in the order in which they appear. In most instances, the product was clear at room temperature.

COMPONENT PERCENT (raeight) DMM 1 1.00 COVI-OX-T-70 2 1.00 HFE-7100 3 1.00 PF-5058 3 1.00 Shell Sol 142 HT 4 96.00 1- DMM, dipropylene glycol dimethyl ether. One of a group of ethers which are useful in the present invention although propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol n-propyl ether, and dipropylene glycol methyl ether have sufficiently high vapor pressures to be useful.
2- An antioxidant useful to prevent hydro peroxide formation in glycol ethers 3- HFE-7100, HFE-7200, PF-5070, PF-5080, PF-5058, PF-5052, PF-5056, and PF-5060. Several of a group of Perfluoro compounds used to effectively suppress flash points of the low flash point petroleum solvents and glycol ethers although perfluoro compounds with carbons atoms varying from C3-C18 are useful.

4- Naphtha, Shell Sol 142 HT, DF-2000, Stoddard solvent, and mineral spirits. A group of low flash point petroleum fractions, primarily a combination of C9-C12 aliphatic hydrocarbons.

COMPONENT PERCENT

(weight) DMM 1.00 COVI-OX-T-70 1.00 HFE-7100 1.00 PF-5058 1.00 Shell Sol 142 HT 96.00 1 5 DMM 5 . 0 0 COVI-OX-T-70 1.00 HFE-7100 5.00 PF-5058 3.00 Shell Sol 142 HT 86.00 DMM 15.00 COVI-OX-T-70 1.00 HFE-7100 10.00 PF-5058 5.00 Shell Sol 142 HT 69.00 DMM 4.00 Dimethylpolysiloxane .10 HFE-7100 1.00 HFE-71DE 5.00 PF-5070 5.00 Shell Sol 142 HT 85.90 4.00 Shell Sol 142 HT 75.00 HFE-71D90 5.00 HFE-7100 15.00 PF-5058 1.00 1 0 DMM 5 . 0 0 Shell Sol 142 HT 80.00 COVI-OX-T-70 .10 HFE-7100 10.00 PF-5060 4.90 DMM 5.00 Shell Sol 142 HT 88.52 HFE-7100 4.00 COVI-OX-T-70 .10 PF-5060 2.38 DMM 1.00 Stoddard Solvent 80.90 COVI-OX-T-70 .10 HFE-7100 10.00 PF-5058 8.00 pNp 1.00 DF-2000 96.00 COVI-OX-T-70 .10 HFE-7100 1.90 PF-5058 1.00 pNp 5.00 DF-2000 86.90 COVI-OX-T-70 .10 HFE-7100 5.00 PF-5058 3.00 pNp 15.00 DF-2000 69.00 COVI-OX-T-70 .10 HFE-7100 10.00 PF-5058 5.90 pNp 3.00 DPM 1.00 DF-2000 89.90 COVI-OX-T-70 .10 HFE-7100 1.00 PF-5070 5.00 DMM 1.00 Odorless Mineral Spirits 80.90 COVI-OX-T-70 .10 HFE-7200 10.00 PF-5058 8.00 DMM 5.00 DF-2000 80.02 COVI-OX-T-70 .10 HFE-7200 4.88 PF-5060 10.00 1.00 DF-2000 90.00 COVI-OX-T-70 .10 HFE-7200 6'88 PF-5060 2.02 DF-2000 93.00 HFE-7100 3.00 PF-5058 4.00 DF-2000 90.00 HFE-7100 5.00 PF-5058 5.00 Shell Sol 142-HT 95.00 HFE-7100 5.00 PF-5058 5.00 Shell Sol 142-HT 92.00 HFE-7200 3.00 PF-5052 5.00 Shell Sol 142-HT 95.00 HFE 7100 1.00 PF-5080 4.00 Shell Sol 142-HT 95.00 HFE-7200 2.00 PF-5060 3.00 Shell Sol 142 95.00 HFE-7100 1.00 PF-5070 4.00 DF-2000 92.00 HFE-7200 2.00 PF-5052 6.00 DF-2000 96.00 HFE-7200 1.00 PF-5060 3.00 DF-2000 95.00 HFE-7100 1.00 PF-5080 4.00 DF-2000 95.00 HFE-7100 1.00 PF-5070 4.00 The specific embodiments herein disclosed, since these embodiments are intended as illustrations of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.
Various references are cited herein, the disclosures of which are incorporated by reference in their entireties.

Claims (20)

WHAT IS CLAIMED IS:

1. A non-aqueous composition comprising:
i. about 0.5% to about 80% by weight of at least one perfluoro compound.
ii. about 2% to about 98% by weight of a solvent naphtha, mineral spirit, or medium aliphatic hydrocarbon; and iii. about 1% to about 98% by weight of a glycol ether or glycol ether acetate.

2. The composition according to claim 1 wherein said composition comprises about 3 to about 40%, more preferably about 3 to about 30% by weight and most preferably about 4%
to about 25% by weight of at least one perfluoro compound.

3. The composition according to claim 1 wherein said solvent naphtha, mineral spirit, or medium aliphatic hydrocarbon is selected from the group consisting of normal paraffins, iso paraffins and light petroleum distillates.

4. The composition according to claim 3 wherein said composition comprises about 30% to about 97% or preferably about 63% to about 95% by weight of petroleum distillates.

5. The composition according to claim 4 wherein said perfluoro compounds have about 3 to about 18 carbon atoms.

6. The composition according to claim 1 wherein said composition comprises about 3 to about 60% by weight, more preferably about 4 to about 40% by weight, or even more preferably about 5% to about 15% by weight of glycol ether.

7. The composition according to claim 1 which further comprises a hydrofluoroether compound.

8. The method according to claim 1 in which the hydrofluroether compound is hydrofluoroethylene.

9. The composition according to claim 1 which further comprises a hydrofluoroether compound/trans-1,2-dichloroethylene mixture.

10. The composition according to claim 9 in which the hydrofluoroether compound/trans-1,2-dichloroethylene mixture is a hydrofluoroethylene/trans-1,2-dichloroethylene mixture.

11. The composition according to claim 10 in which the hydrofluoroethylene/trans-1,2-dichloroethylene mixture is an azeotropic mixture.

12. The composition according to claim 10, in which the ratio of hydrofluoroethylene to trans-1,2-dichloroethylene is from about 5:95 to about 95:5.

13. The composition according to claim 1, in which the composition further comprises at least one component selected from the group consisting of an antimicrobial agent, a fabric finishing agent, an anionic surfactant and mixtures thereof.

14. An essentially nonaqueous composition comprising:
i. about 0.5% to about 80% by weight of at least one perfluoro compound.

ii. about 2% to about 98% by weight of a solvent naphtha, mineral spirit, or medium aliphatic hydrocarbon; and iii. about 0.5% to about 80% by weight of a hydrofluoroether compound.

15. The composition according to claim 14, in which the composition comprises a hydrofluoroether/trans-1,2-dichloroethylene mixture.

16. A nonaqueous composition comprising:
i. about 1% to about 98% by weight of a glycol ether or glycol ether acetate;
ii. about 2% to about 98% by weight of a solvent naphtha, mineral spirit, or medium aliphatic hydrocarbon; and iii. about 0.5% to about 80% by weight of a hydrofluoroether compound.

17. A method for removing one or more contaminants from textiles, fabrics, garments, flexible or inflexible surfaces comprising applying the nonaqueous composition of claim 1, 14 or 16 to said textiles, fabrics, garments, flexible or inflexible surfaces in an amount effective to remove said contaminants from said textiles, fabrics, garments, flexible or inflexible surfaces.

18. The method according to claim 17 in which the flexible or inflexible surface is machinery or metal surfaces.

19. The method according to claim 17, which further comprises (a)recovering a composition/contaminant mixture;
(b)distilling said composition/contaminant mixture of step (a) to separate said contaminant from said composition and (c) isolating said contaminant.

20. Use of the composition of claim 1, 14 or 16 for removing one or more contaminants from textiles, fabrics, garments, flexible or inflexible surfaces comprising applying the nonaqueous composition of claim 1, 14 or 16 to said textiles, fabrics, garments, flexible or inflexible surfaces.