Background of the Invention Commercial dry cleaning systems currently employ potentially toxic and environmentally harmful halocarbon solvents, such as perchloroethylene. Carbon dioxide has been proposed as an alternative to such systems in U. S. Patent No. 4,012, 194 to Maffei.

German Patent Application DE3904514 A1 of Schollmeyer, published August 23,1990, describes a cleaning system combining various conventional anionic or nonionic surface active agents with supercritical C02. The system described therein appears to combine the detergency mechanism of conventional surface active agents with the solvent power of supercritical fluid carbon dioxide. A carbon dioxide dry cleaning system effective for liquid carbon dioxide is not provided.

U. S. Patent No. 5,683,473 to Jureller et al. (see also 5,683,977 to Jureller et al.) describes a dry cleaning system utilizing carbon dioxide in liquid form in combination with surfactants that contain a functional moiety that is C02-philic, which surfactants are not conventionally used for detergent cleaning. Since there are numerous advantages to employing conventional surfactants (e. g., cost, ready availability, established regulatory approval, established toxicology, etc), it would be

extremely desirable to have a dry cleaning system for liquid carbon dioxide that employs conventional surfactants that do not contain a C02-philic group.

U. S. Patent No. 5,858,022 to Romack et al. describes dry methods and compositions for dry cleaning in liquid carbon dioxide formulations in which a conventional surfactant (i. e., one that does not contain a C02-philic group) is used in combination with an organic co-solvent. The conventional surfactant is soluble in the organic co-solvent. Ingredients such as bleaches, whiteners, softeners, sizing, starching, enzymes, hydrogen peroxide or a source of hydrogen peroxide, are described at column 3 lines 39-43, but recommendations for the structure or composition of ingredients that are particularly advantageous in carbon dioxide cleaning formulations, as opposed to functional statements thereof, are not provided.

U. S. Patent No. 5,863,298 to Fulton et al. suggests methods of sizing and desizing yarn with a liquid carbon dioxide solvent for yarn processing, but does not suggest methods of sizing articles to be cleaned that can be used in a dry cleaning operation. Accordingly, there is a continued for additives or ingredients that can be advantageously employed with carbon dioxide cleaning formulations.

Summary of the Invention A method for dry-cleaning garments or fabrics in carbon dioxide, while also applying a sizing agent to the article, comprises contacting a garment or fabric article to be cleaned with a liquid dry cleaning composition for a time sufficient to clean the article, said liquid dry-cleaning composition comprising a mixture of carbon dioxide, surfactant, and a sizing agent. In a preferred embodiment, the sizing agent is a hydrocarbon resin having a molecular weight of from about 500 to about 3000 grams per mole. The contacting step is followed by the step of separating the article from the liquid dry cleaning composition with said sizing agent deposited thereon (preferably at a weight on goods of about. 05 to about 3 percent).

Preferably, the liquid dry cleaning composition is at ambient temperature, of about 0° C to 30° C. Preferably, the surfactant is soluble in the co-solvent. The surfactant may or may not be soluble in the C02. Hence, in one embodiment; the surfactant may contain a C02-philic group. However, in the preferred embodiment, the surfactant does not contain a C02-philic group. Hence, an advantage of the present

invention is that, by proper use of the co-solvent, conventional surfactants may be employed in a liquid carbon dioxide dry cleaning system.

Detailed Description of the Invention The term"clean"as used herein refers to any removal of soil, dirt, grime, or other unwanted material, whether partial or complete. The invention may be used to clean nonpolar stains (i. e., those which are at least partially made by nonpolar organic compounds such as oily soils, sebum and the like), polar stains (i. e., hydrophilic stains such as grape juice, coffee and tea stains), compound hydrophobic stains (i. e., stains from materials such as lipstick and candle wax), and particular soils (i. e., soils containing insoluble solid components such as silicates, carbon black, etc.).

Articles that can be cleaned by the method of the present invention are, in general, garments and fabrics (including woven and non-woven) formed from materials such as cotton, wool, silk, leather, rayon, polyester, acetate, fiberglass, furs, etc., formed into items such as clothing, work gloves, rags, leather goods (e. g., handbags and brief cases), etc.

1. Cleaningprocesses.

The present invention may be carried out in any suitable carbon-dioxide based dry cleaning system, such as those described in U. S. Patents Nos. 5,858,022 to Romack et al. or 5,683,473 to Jureller et al., the disclosures of which are incorporated by reference herein in their entirety.

Liquid dry-cleaning compositions useful for carrying out the present invention typically include water. The source of the water is not critical in all applications. The water may be added to the liquid solution before the articles to be cleaned are deposited therein, may be atmospheric water, may be the water carried by the garments, etc.

In one embodiment of the invention, better particulate cleaning may be obtained in the absence of water added to the dry-cleaning composition. There is inherently water present on or in the garments or articles to be cleaned as they are placed in the cleaning vessel. This water serves in part to adhere particulate soil to the articles to be cleaned. As the water is removed from the garments into the cleaning composition during the cleaning process, the removal of water from the

article to be cleaned facilitates the removal of particulates from the articles to be cleaned. Thus, decreasing the amount of water originally in the cleaning system can serve to facilitate the cleaning of particulate soil from the articles to be cleaned by the action of the water inherently carried by the article to be cleaned.

Liquid dry-cleaning compositions useful for carrying out the present invention typically comprise: (a) from zero (0), 0.02,0.05 or 0.1 to 5 or 10 percent (more preferably from. 1 to 4 percent) water; (b) carbon dioxide (to balance; typically at least 30 percent); (c) surfactant (preferably from 0.1 or. 5 percent to 5 or 10 percent total, which may be comprised of one or more different surfactants); and (d) from 0.1 to 50 percent (more preferably 1,2 or 4 percent to 30 percent) of an organic co-solvent.

(e) a sizing agent (discussed below), preferably in an amount of from about 0.1% to 25%, preferably between 1 and 5%.

Percentages herein are expressed as percentages by weight unless otherwise indicated.

The composition is provided in liquid form at ambient, or room, temperature, which will generally be between zero and 50° Centigrade. The composition is held at a pressure that maintains it in liquid form within the specified temperature range. The cleaning step is preferably carried out with the composition at ambient temperature.

The organic co-solvent is, in general, a hydrocarbon co-solvent. Typically the co-solvent is an alkane co-solvent, with Cl0 to C20 linear, branched, and cyclic alkanes, and mixtures thereof (preferably saturated) currently preferred. The organic co-solvent preferably has a flash point above 140°F, and more preferably has a flash point above 170°F. The organic co-solvent may be a mixture of compounds, such as mixtures of alkanes as given above, or mixtures of one or more alkanes. Additional compounds such as one or more alcohols (e. g., from 0 or 0.1 to 5% of a C1 to C15 alcohol (including diols, triols, etc.)) different from the organic co-solvent may be included with the organic co-solvent.

Examples of suitable co-solvents include, but are not limited to, aliphatic and aromatic hydrocarbons, and esters and ethers thereof, particularly mono and di-esters and ethers (e. g., EXXON ISOPAR L, ISOPAR M, ISOPAR V, EXXON EXXSOL, EXXON DF 2000, CONDEA VISTA LPA-170N, CONDEA VISTA LPA-210,

cyclohexanone, and dimethyl succinate), alkyl and dialkyl carbonates (e. g., dimethyl carbonate, dibutyl carbonate, di-t-butyl dicarbonate, ethylene carbonate, and propylene carbonate), alkylene and polyalkylene glycols, and ethers and esters thereof (e. g., ethylene glycol-n-butyl ether, diethylene glycol-n-butyl ethers, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, and dipropylene glycol methyl ether acetate), lactones (e. g., (gamma) butyrolactone, (epsilon) caprolactone, and (delta) dodecanolactone), alcohols and diols (e. g., 2- propanol, 2-methyl-2-propanol, 2-methoxy-2-propanol, 1-octanol, 2-ethyl hexanol, cyclopentanol, 1,3-propanediol, 2,3-butanediol, 2-methyl-2,4-pentanediol) and polydimethylsiloxanes (e. g., decamethyltetrasiloxane, decamethylpentasiloxane, and hexamethyldisloxane), etc.

Any surfactant can be used to carry out the present invention, including both surfactants that contain a CO2-philic group (such as described in PCT Application W096/27704) linked to a CO2-phobic group (e. g., a lipophilic group) and (more preferably) surfactants that do not contain a C02-philic group (i. e., surfactants that comprise a hydrophilic group linked to a hydrophobic (typically lipophilic) group). A single surfactant may be used, or a combination of surfactants may be used.

Numerous surfactants are known to those skilled in the art. See, e. g., McCutcheon's Volume 1: Emulsifiers & Detergents (1995 North American Edition) (MC Publishing Co., 175 Rock Road, Glen Rock, NJ 07452). Examples of the major surfactant types that can be used to carry out the present invention include the: alcohols, alkanolamides, alkanolamines, alkylaryl sulfonates, alkylaryl sulfonic acids, alkylbenzenes, amine acetates, amine oxides, amines, sulfonated amines and amides, betaine derivatives, block polymers, carboxylated alcohol or alkylphenol ethoxylates, carboxylic acids and fatty acids, diphenyl sulfonate derivatives, ethoxylated alcohols, ethoxylated alkylphenols, ethoxylated amines and/or amides, ethoxylated fatty acids, ethoxylated fatty esters and oils, fatty esters, fluorocarbon-based surfactants, glycerol esters, glycol esters, hetocyclic-type products, imidazolines and imidazoline derivatives, isethionates, lanolin-based derivatives, lecithin and lecithin derivatives, lignin and lignin derivatives, maleic or succinic anhydrides, methyl esters, monoglycerides and derivatives, olefin sulfonates, phosphate esters, phosphorous organic derivatives, polyethylene glycols, polymeric (polysaccharides, acrylic acid, and acrylamide) surfactants, propoxylated and ethoxylated fatty acids alcohols or

alkyl phenols, protein-based surfactants, quaternary surfactants, sarcosine derivatives, silicone-based surfactants, soaps, sorbitan derivatives, sucrose and glucose esters and derivatives, sulfates and sulfonates of oils and fatty acids, sulfates and sulfonates, ethoxylated alkylphenols, sulfates of alcohols, sulfates of ethoxylated alcohols, sulfates of fatty esters, sulfonates of benzene, cumene, toluene and xylene, sulfonates of condensed naphthalenes, sulfonates of dodecyl and tridecylbenzenes, sulfonates of naphthalene and alkyl naphthalene, sulfonates of petroleum, sulfosuccinamates, sulfosuccinates and derivatives, taurates, thio and mercapto derivatives, tridecyl and dodecyl benzene sulfonic acids, etc.

Additional examples of surfactants that can be used to carry out the present invention include alcohol and alkylphenol polyalkyl ethers (e. g., TERGITOL 15-S-3TM secondary alcohol ethoxylate, TRITON X-207Tm dinonylphenol ethoxylate, NEODOL 91-2.5TM primary alcohol ethoxylate, RHODASURF BC-410TM isotridecyl alcohol ethoxylate, RHODASURF DA-630TM tridecyl alcohol ethoxylate) alkylaryl carbonates, including salts and derivatives thereof (e. g., acetic acid, MARLOWET 4530TM dialkylphenol polyethylene glycol acetic acid, MARLOWET 1072 alkyl polyethylene glycol ether acetic acid), alkoxylated fatty acids (e. g., NOPALCOL 1- TWTM diethylene glycol monotallowate, TRYDET 2600TM polyoxyethylene (8) monostearate), alkylene oxide block copolymers (e. g., PLURONICTM and TETRONICTM products), acetylenic alcohols and diols (e. g., SURFYNOLTM and DYNOLTM products), mono-and di-esters of sulfosuccinic acid (e. g., AEROSOL OTTM sodium dioctyl sulfosuccinate, AEROSOL IB-45TM sodium diisobutyl sulfosuccinate, MACKANATE DC-50 dimethicone copolyol disodium sulfosuccinate, SOLE TERGE-8TM oleic acid isopropanolamide monoester of sodium sulfosuccinate), sulfosuccinamic acid and esters thereof (e. g. AEROSOL 18TM disodium-N-octadecyl sulfosucciniamate, AEROSOL 22TM tetrasodium N- (1,2- dicarboxyethyl)-N octadecyl sulfosuccinamate) sorbitan esters including derivatives thereof (e. g., SPAN 80TM sorbitan monoleate, ALKAMULS 400-DOTM sorbitan dioleate, ALKAMULS STOTM sorbitan trioleate, TWEEN 81TM polyoxyethylene (5) sorbitan monoleate, TWEEN 21 polyoxyethylene (4) sorbitan monolaurate), isothionates including derivatives thereof (e. g., GEROPON AC-270TM sodium cocoyl isothionate), polymeric alkylaryl compounds and lignins, including derivatives thereof (e. g., LIGNOSITE 50TM calcium lignosulfonate), alkylaryl sulfonic acids and salts

thereof (e. g., CALIMULSE EM-99TM branched dodecylbenzene sulfonic acid, WITCONATE C-50HTM sodium dodecylbenzene sulfonate, WITCONATE P10-59TM amine salt of dodecylbenzene sulfonate), sulfonated amines and amides (e. g., CALIMULSE PRSTM isopropylamine sulfonate), Betaine and sultaine derivatives, and salts thereof (e. g., lauryl sulfobetaine, dodecyldimethyl (3-sulfopropyl) ammonium hydroxide, FOAMTAIN CAB-ATM cocamidopropyl betaine ammonium salt, FOAMTAINE SCABTM cocamidopropyl hydroxy sultaine), e. g., imidazolines including derivatives thereof (e. g., MONOAZOLINE OTM substituted imidazoline of oleic acid, MONOAZOLINE TTM substituted imidazoline of Tall Oil), oxazolines including derivatives thereof (e. g., ALKATERGE ETM oxazoline derivative, ALKATERGE T-IVTM ethoxylated oxazoline derivative), carboxylated alcohol or alkylphenol ethoxylates including derivatives thereof (e. g., MARLOSOL OL7TM oleic acid polyglycol ester), diphenyl sulfonates including derivatives thereof (e. g., DOWFAXTM detergent diphenyl oxide disulfonate, DOWFAXTM dry detergent: sodium n-hexadecyl diphenyl oxide disulfonate, DOWFAXTM Dry hydrotrope: sodium hexyl diphenyloxide disulfonate) fluorinated surfactants (e. g., FLUORAD Foc-120 ammonium perfluoroalkyl sulfonate, FLUORAD FC-135TM fluoroalkyl quaternary ammonium iodides, FLUORAD Foc-143 ammonium perfluoroalkyl carboxylates), lecithins including lecithin derivatives (e. g., ALCOLEC BSTM soy phosphatides), phosphate esters (e. g., ACTRAFOS SA-216 aliphatic phosphate ester, ACTRAFOS I I OTM phosphate ester of complex aliphatic hydroxyl compound, CHEMPHOS Toc-310 aromatic phosphate ester, CALGENE PE-112NTM phosphated mono-and diglycerides), sulfates and sulfonates of fatty acids (e. g., ACTRASOL PSRTM sulfated castor oil, ACTRASOL SR75TM sulfated oleic acid), sulfates of alcohols (e. g., DUPONOL CTM sodium lauryl sulfate, CARSONOL SHSTM sodium 2-ethyl-1-hexyl sulfate, CALFOAM TLS-40TM triethanolamine lauryl sulfate), sulfates of ethoxylated alcohols (e. g., CALFOAM ES-301 sodium lauryl ether sulfate), amines, including salts and derivatives thereof (e. g., Tris (hydroxymethyl) aminomethane, ARMEENTM primary alkylamines, ARMAC HTTM acetic acid salt of N-alkyl amines) amide sulfonates (e. g., GEROPON TC-42TM sodium N-coconut acid-N-methyl taurate, GEROPON TC 270TM sodium cocomethyl tauride), quaternary amines, including salts and derivatives thereof (e. g., ACCOSOFT 750TM methyl bis (soya amidoethyl)-N-polyethoxyethanol quaternary ammonium

methyl sulfate, ARQUADTM N-alkyl trimethyl ammonium chloride, ABIL QUAT 3272TM diquaternary polydimethylsiloxane), amine oxides (e. g., AMMONYX COTM cetyl dimethylamine oxide, AMMONYX SOTM stearamine oxide), esters of glycerol, sucrose, glucose, sarcosine and related sugars and hydrocarbons including their derivatives (e. g., GLUCATE DOTM methyl glucoside dioleate, GLICEPOL 180TM glycerol oleate, HAMPOSYL AL-30 ammonium lauroyl sarcosinate, HAMPOSYL MTM N-myristoyl sarcosine, CALGENE CCTM propylene glycol dicaprylate/dicaprate), polysaccharides including derivatives thereof (e. g., GLUCOPON 225 DKTM alkyl polysaccharide ether), protein surfactants (e. g., AMITER LGS-2 dioxyethylene stearyl ether diester of N-lauroyl-L-glutamic acid, AMISOFT CATM cocoyl glutamic acid, AMISOFT CS l l sodium cocoyl glutamate, MAYTEIN KTSTM sodium/TEA lauryl hydrolyzed keratin, MAYPON 4CTM potassium cocoyl hydrolyzed collagen), and including thio and mercapto derivatives of the foregoing (e. g, ALCODETT polyoxyethylene thioether, BURCO TMETM ethoxylated dodecyl mercaptan), etc.

Thus the present invention may be carried out using conventional surfactants, including but not limited to the anionic or nonionic alkylbenzene sulfonates, ethoxylated alkylphenols and ethoxylated fatty alcohols described in Schollmeyer German Patent Application DE 39 04514 A1, that are not soluble in liquid carbon dioxide and which could not be utilized in the invention described in U. S. Patent No.

5,683,473 to Jureller et al. or U. S. Patent No. 5,683,977 to Jureller et al.

As will be apparent to those skilled in the art, numerous additional ingredients can be included in the dry-cleaning composition, including detergents, bleaches, whiteners, softeners, sizing, starches, enzymes, hydrogen peroxide or a source of hydrogen peroxide, fragrances, etc.

In practice, in a preferred embodiment of the invention, an article to be cleaned and a liquid dry cleaning composition as given above are combined in a closed drum. The liquid dry cleaning composition is preferably provided in an amount so that the closed drum contains both a liquid phase and a vapor phase (that is, so that the drum is not completely filled with the article and the liquid composition). The article is then agitated in the drum, preferably so that the article contacts both the liquid dry cleaning composition and the vapor phase, with the agitation carried out for a time sufficient to clean the fabric. The cleaned article is

then removed from the drum. The article may optionally be rinsed (for example, by removing the composition from the drum, adding a rinse solution such as liquid C02 (with or without additional ingredients such as water, co-solvent, etc.) to the drum, agitating the article in the rinse solution, removing the rinse solution, and repeating as desired), after the agitating step and before it is removed from the drum. The dry cleaning compositions and the rinse solutions may be removed by any suitable means, including both draining and venting.

Any suitable cleaning apparatus may be employed, including both horizontal drum and vertical drum apparatus. When the drum is a horizontal drum, the agitating step is carried out by simply rotating the drum. When the drum is a vertical drum it typically has an agitator positioned therein, and the agitating step is carried out by moving (e. g., rotating or oscillating) the agitator within the drum. A vapor phase may be provided by imparting sufficient shear forces within the drum to produce cavitation in the liquid dry-cleaning composition. Finally, in an alternate embodiment of the invention, agitation may be imparted by means of jet agitation as described in U. S.

Patent No. 5,467,492 to Chao et al., the disclosure of which is incorporated herein by reference. As noted above, the liquid dry cleaning composition is preferably an ambient temperature composition, and the agitating step is preferably carried out at ambient temperature, without the need for associating a heating element with the cleaning apparatus.

Particularly preferred apparatus for carrying out the present invention, in which sizing can be added in like manner to detergent, is disclosed in commonly owned, copending patent application of James P. DeYoung, Timothy J. Romack, and James B. McClain, Serial No. 09/312,556, titled Detergent Injection Systems for Carbon Dioxide Cleaning Apparatus, filed May 14,1999, the disclosure of which is incorporated by reference herein in its entirety.

2. Sizing avents.

As noted above, a sizing agent is preferably added to the cleaning composition during the cleaning step so that the sizing agent is deposited on the articles to be cleaned when they are removed from the cleaning apparatus. As will be appreciated, the sizing agent must be selected so that it is uniformly and cleanly deposited, to impart the desired feel and appearance to the cleaned article, without imparting blemishes or clumps, or rendering the cleaned article unduly rigid.

It has now been found that low molecular weigh hydrocarbon resins are particularly advantageous for use as sizing agents in carbon dioxide cleaning processes. These materials are particularly advantageous because of their solubility in carbon dioxide, combined their relatively high deposition rate on the articles to be cleaned without undue removal or extraction from the articles. Further, these materials are advantageous because, the deposition of relatively low amounts provides the desired feel and appearance to the articles to be cleaned.

In general, low molecular weight hydrocarbon resins are resins characterized by a molecular weight of about 500,600 or 800 up to about 1500,2000 or 3000 grams per Mole. In general, such hydrocarbon resins are characterized by a chain length of C4 or C5 to C9 or C10. Suitable resins are available from a variety of sources, such as the ESCOREZTM hydrocarbon resins available from Exxon Chemical, Houston, Texas, USA, and PICCOTAC BTM, hydrocarbon resin (MW=1650), available from Hercules Inc., Wilmington, Delaware USA.

The present invention is explained in greater detail in the following non- limiting examples. In these examples, weight on goods (WOG) is expressed as the percentage increase in weight of the goods resulting from the deposition of size thereon.

EXAMPLE 1 Carbon Dioxide Dry-Cleaning Composition An additional example of a liquid carbon dioxide dry cleaning system that can be used to carry out the present invention is a mixture that contains: 4.2% ISOPAR MTM organic solvent; 0.24% water; 0.196% TRITONTM RW-20 (commercial detergent available from Union Carbide; a secondary amine ethoxylate); 0.048% TRITONTM GR-7M detergent (a commercial detergent of Union Carbide; sodium dioctyl sulfosuccinate in aromatic and aliphatic hydrocarbons) 0.48% TERGITOLTM 15-S-3 detergent (a commercial detergent of Union Carbide; a secondary alcohol ethoxylate); and liquid carbon dioxide to balance.

EXAMPLE 2 Carbon Dioxide Drv-Cleaning Composition An additional example of a liquid carbon dioxide dry cleaning system that can be used to carry out the present invention is a mixture that contains: 3.07% ISOPAR MTM organic solvent; 1.32% DPMA (diopropylene glycol monomethyl ether acetate); 0.087% water; 0.023% TRITONTM GR-7M detergent (a commercial detergent of Union Carbide; sodium dioctyl sulfosuccinate in aromatic and aliphatic hydrocarbons) 0.5% TERGITOLTM 15-S-3 detergent (a commercial detergent of Union Carbide; a secondary alcohol ethoxylate); and liquid carbon dioxide to balance.

The liquid dry cleaning systems of Examples 1 and 2 are currently preferred.

EXAMPLE 3 Carbon Dioxide Dry-Cleanin Composition An additional example of a liquid carbon dioxide dry cleaning system that can be used to carry out the present invention, particularly useful for the cleaning of particulate soil, is a mixture that contains: 4. 2% ISOPAR MTM organic solvent; 0.196% TRITONTM RW-20 (commercial detergent available from Union Carbide; a secondary amine ethoxylate); 0.048% TRITONTM GR-7M detergent (a commercial detergent of Union Carbide; sodium dioctyl sulfosuccinate in aromatic and aliphatic hydrocarbons) 0.48% TERGITOLTM 15-S-3 detergent (a commercial detergent of Union Carbide; a secondary alcohol ethoxylate); and liquid carbon dioxide to balance.

EXAMPLE 4 Carbon Dioxide Dry-Cleaning Composition An additional example of a liquid carbon dioxide dry cleaning system that can be used to carry out the present invention, also particularly useful for cleaning particulate soil, is a mixture that contains: 3.07% ISOPAR MTM organic solvent; 1.32% DPMA (diopropylene glycol monomethyl ether acetate); 0.023% TRITONTM GR-7M detergent (a commercial detergent of Union Carbide; sodium dioctyl sulfosuccinate in aromatic and aliphatic hydrocarbons) 0.5% TERGITOLTM 15-S-3 detergent (a commercial detergent of Union Carbide; a secondary alcohol ethoxylate); and liquid carbon dioxide to balance.

EXAMPLES 5-6 Evaluation of Sizing Agents The goal of these expamples was to evaluate the stability of different sizing materials. Stability was evaluated as a function of concentration and time.

The detergent formulation can be added to the carbon dioxide to provide a dry cleaning formulation in the wash vessel in the form of an aliquot or"pill". The pill is pre-pressurized under a head pressure of carbon dioxide gas to about 700 psi prior to addition to the wash vessel. If it is assumed that the volume of the pill is 1.5L and the total amount of goods equals 601bs. (27kg), then to achieve a 0.25% WOG, one would need to add 67.5g of size to the clothes or 0.045g size/mL of soap in the pill. Thus: (0.0025) (27,000g) =67.5g size; 67.5g size/1.5L=0.045g size/mL fluid in the pill.

Initial studies showed that the stability of the sizing materials under pre-pressurization conditions in the cleaning apparatus is inversely proportional to the molecular weight.

That is, stability increases with decreasing molecular weight. Three lower molecular weight materials, two C5 hydrocarbon resins (1100 and 1400g/mole) and a C5-C9 hydrocarbon resin (450g/mol), were used. These materials were various ESCOREZTM hydrocarbon resins, available from Exxon Chemical, Houston, Texas, USA. As shown below, the C5 hydrocarbon resin, ESCOREZTM 1580 (MW=1100), is the most

stable of the materials evaluated for the length of time that it must sit in the pill (about 20 minutes). These results indicate that the material is stable at a concentration of 0.03g size/mL ISOPAR MTM solvent, which would deliver approximately 0.17% WOG. Since this WOG seemed small, we wanted to evaluate how much size is extracted from garments after being washed in C02 to determine how much size should be added. Further experiments indicated that very little size is extracted from garments washed in C02, unlike perc and petroleum.

EXAMPLE 5 Pre-Pressurization of Various Hydrocarbon Resins All pre-pressurization experiments were conducted at 17°C by adding 5 mL of a solution of size in ISOPAR MTM solvent to a 10-mL view cell. A second 10-mL view cell was filled 3/4 full with CO2. Vapor side communication was opened between the two cells. T=0 is the time in which the two cells were equilibrated. Results with various potential sizing agents are given in Tables 1-3 below.

TABLE 1: ESCOREZTM 2520 C5-9 Hydrocarbon Resin (MW=450g/mol). Time0.01g size/mL 0. 02g size/mL0.04g size/mL ISOPARMTM ISOPAR MTMISOPARMTM WOG=0.06% WOG=0. 11 % WOG=0.22% T=0Clearwith ClearwithClearwith convectioncurrents convectioncurrentsconvectioncurrents T=10"Startedtoforma2-phasecloudytop min secondphaselayer,clearbottom layer T=202-phasebothlayers 2-phasebothlayers" minclear"jelly-like areclear"jelly-like material"onbottom material"onbottom ofcell ofcell T=45Phasesinverted 2-phasetoplayer" min"jelly-likematerial"hazybottomlayer intoplayer clear TABLE 2: ESCOREZ 1580 C5 Hydrocarbon Resin (MW=1100g/mol) Time0.02gsize/mL0.03gsize/mL0.045gsize/mL ISOPARMTMISOPARMTMISOPARMTM WOG=0.11 % WOG=0. 17% WOG=0.25% T=0Clearwith ClearwithClearwith convectioncurrentsconvectioncurrentsconvectioncurrents T=30 sec""Hazy T=1min""Verycloudy T=2min 2-phasecloudytop layer,clearbottom layer T=4min 3-phase! T=5min3-phasedropletson window T=10 2-phasecloudytop minlayer,clearbottom layer-droplets T=20""" min min min TABLE 3: ESCOREZ 1310 LC C5 Hydrocarbon Resin (MW=1400g/mol) Time0.003gsize/mL0.02gsize/mL0.04gsize/mL ISOPARMTMISOPARMTMISOPARMTM WOG=0.017%WOG=0.11% WOG=025% T=0 ClearwithClearwithClearwith convectioncurrentsconvectioncurrentsconvectioncurrents T=30 sec""" T=1min Cloudy T=2min 2-phasecloudytop layer,murkybottom layer T=4 min 3-phase! T=6min3-phasedropletson window T=10"Startedtoform2-2-phasecleartop minphaseslayer,cloudybottom layer-droplets T=25Startedtoform2-2-phases" min phases T=35 2 phases"" mincloudytoplayer clearbottomphase T=452-phases2-phases mincleartoplayerhazytoplayer cloudybottomlayerclearbottomlayer

EXAMPLE 6 Extraction Experiments In addition to the stability testing in the view cell, extraction experiments were conducted in a prototype apparatus. Heavily sized fabric sized with partially hydrolyzed poly (vinyl acetate) from wrinkle resistant khaki pants was cut into 4-inch square. These swatches were pre-weighed and washed 4 times using a charge soap that makes up approximately 5% of the C02-based solvent, as follows: 90.9% Isopar M organic solvent; 1.1% dioctyl sulfosuccinate, sodium salt (AOT-100); 3.5% Tergitol 15-S-3 surfactant; 0.5% Triton RW-20 surfactant; and 4.0% water.

The swatches were damp coming out of apparatus and were allowed to equilibrate for 24 hours prior to the final weighing and ironing.

It was difficult to quantify the amount of size extracted from the swatches as their weights varied significantly. (Possible sources of error include moisture in the air, time out of the wheel between runs, moisture uptake from the detergent and any soap deposition that may have occurred.) However, there was no apparent difference between swatches washed repeatedly and a virgin swatch. The washed swatches were ironed and appeared to hold a crease as well as the virgin sample.

The foregoing is illustrative of the present invention, and is not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein.