Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
DRY CLEANING COMPOSITIONS WITH ANTI-STATIC BENEFITS
Document Type and Number:
WIPO Patent Application WO/1997/000991
Kind Code:
A1
Abstract:
Dry cleaning compositions are formulated with anti-static agents and are suitable for home use. Thus, cleaning compositions comprising water, butoxy propoxy propanol, optional 1,2-octanediol and optional surfactants are formulated with anionic anti-static agents such as sulfonated polystyrene or sulfonated polystyrene/maleic anhydride polymers to provide anti-static benefits to garments. The composition is placed on a pad or other carrier and tumbled with garments in a hot air clothes dryer. The garments are cleaned and free from static electricity.

Inventors:
ROETKER TIMOTHY CLAIRE
MASTERS RONALD ANTHONY
Application Number:
PCT/US1996/007125
Publication Date:
January 09, 1997
Filing Date:
May 17, 1996
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
PROCTER & GAMBLE (US)
International Classes:
C11D3/20; C11D3/37; D06L1/00; D06L1/02; D06L1/04; (IPC1-7): D06L1/00; C11D3/20; C11D3/37; D06L1/02; D06L1/04
Foreign References:
US5055215A1991-10-08
DE1925047A11970-11-19
EP0328174A21989-08-16
US4692277A1987-09-08
EP0429172A11991-05-29
US5238587A1993-08-24
Other References:
GUTH J. ET AL.: "MULTIFUNCTIONAL SULFONATED POLYMERS FOR HOUSEHOLD APPLICATIONS", HAPPI HOUSEHOLD AND PERSONAL PRODUCTS INDUSTRY, vol. 31, no. 12, 1 December 1994 (1994-12-01), pages 104, 106, 108, XP000472861
Download PDF:
Claims:
WHAT IS CLAIMED IS:
1. A dry cleaning and spot removal composition, characterized in that it comprises: (a) at least 0.5%, by weight, of an anionic antistatic agent; (b) from 1% to 30%, by weight, of an organic cleaning solvent; (c) optionally, at least 0.01%, by weight of a polyacrylate emulsifier; (d) optionally, from 0.05% to 5%, by weight, of detersive surfactants; and (e) water.
2. A composition according to Claim 1 wherein the antistatic agent is a water soluble sulfonated polymer.
3. A composition according to Claim 2 wherein the antistatic agent is a member selected from the group consisting of sulfonated polystyrene and copolymers of sulfonated polystyrene with unsaturated monomers.
4. A composition according to Claim 1 wherein the organic solvent is a member selected from the group consisting of the monomethyl, monoethyl monopropyl, and monobutylethers of propoxylated propanol, and mixtures thereof.
5. A composition according to Claim 1 wherein the polyacrylate emulsifier has a molecular weight in the range from 100,000 to 10,000,000.
6. A composition according to Claim 1 wherein the detersive surfactant is a member selected from the group consisting of amine oxides, alkyl ethoxy sulfates, alcohol ethoxylates, and mixtures thereof.
7. A composition according to Claim 6 wherein the alkyl ethoxy sulfate surfactant is in its magnesium salt form.
8. A composition according to Claim 1 which additionally comprises at least 0.05%, by weight, of 1,2octanedioI.
9. A method for cleaning fabrics and providing an antistatic benefit thereto, comprising applying to said fabrics a composition according to Claim 1.
10. A method according to Claim 9 which is conducted in a hot air clothes dryer.
11. An article for cleaning fabrics, comprising an integral carrier containing a composition according to Claim 1.
Description:
DRY CLEANING COMPOSITIONS WITH ANTI-STATIC BENEFITS

FIELD OF THE INVENTION

The present invention relates to dry cleaning compositions which are especially adapted for use in the home. The compositions contain anionic ingredients which reduce static electricity on fabrics.

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of co-pending application Serial No. 08/493,198, filed June 20, 1995.

BACKGROUND OF THE INVENTION

By classical definition, the term "dry cleaning" has been used to describe processes for cleaning textiles using nonaqueous solvents. Dry cleaning is an old art, with solvent cleaning first being recorded in the United Kingdom in the 1860's. Typically, dry cleaning processes are used with garments such as woolens which are subject to shrinkage in aqueous laundering baths, or which are judged to be too valuable or too delicate to subject to aqueous laundering processes. Various hydrocarbon and halocarbon solvents have traditionally been used in dry cleaning processes, and the need to handle and reclaim such solvents has mainly restricted the practice of conventional dry cleaning to commercial establishments.

In addition to the cleaning function, dry cleaning also provides important "refreshment" benefits. For example, dry cleaning removes undesirable odors and extraneous matter such as hair and lint from garments, which are then generally folded or pressed to remove wrinkles and restore their original shape. One problem sometimes associated with non-immersion dry cleaning processes relates to the tendency of fabrics to acquire a static charge, thereby resulting in undesirable static "cling". In some instances, this problem can be exacerbated when in-home dry cleaning processes are conducted in a hot air clothes dryer.

By the present invention, it has been discovered that certain multi-functional sulfonated polymers such as sulfonated polystyrene ("SPS") and copolymers of sulfonated polystyrene with various monomers including maleic anhydride (i.e., "SSMA" copolymer) provide anti-static benefits to fabrics when employed in a dry cleaning process. One advantage of this invention is that it provides the anti-static benefit without the problems encountered in using a traditional cationic anti¬ static agent such as ditallowdimethylammonium chloride (DTDMAC) or ditallowdimethyl- ammonium methylsulfate (DTDMAMS). The SPS and SSMA anti-stats herein are compatible with anionic ingredients whereas typical cationic static control agents are not Moreover, unlike DTDMAC, SPS and SSMA are soluble in water, thus facilitating the formulation of combined

cleaning plus anti-static products and delivery of the anti-static agent to fabrics. Furthermore, unlike conventional dryer softener sheets, SPS and SSMA do not need to rely on dryer heat to release and spread on fabrics to achieve the static control benefit Accordingly, when spot treating stains on fabrics prior to tumbling in the dryer, the risk of staining is lower when using such water- soluble anti-stats which do not need to rely on melting and spreading to be effective.

It is an object ofthe present invention to provide cleaning compositions which contain anti¬ static agents. It is another object herein to provide a non-immersion dry cleaning process which imparts anti-static benefits to fabrics. It is yet another object herein to provide an in-home dry cleaning process with anti-static benefits. These and other objects are secured herein, as will be seen from the foregoing disclosures.

BACKGROUND ART Dry cleaning processes are disclosed in: EP 429J72A1, published 29.05.91, Leigh, et al.; and in U.S. 5,238,587, issued 8 24/93, Smith, et al. Other references relating to dry cleaning compositions and processes, as well as wrinkle treatments for fabrics, include: GB 1,598,911; and U.S. Patents 4,126,563, 3,949,137, 3,593,544, 3,647,354; 3,432,253 and 1,747,324; and German applications 2,021,561 and 2,460,239, 0,208,989 and 4,007,362. Cleaning pre-spotting compositions and methods are also disclosed, for example, in U.S. Patents 5,102,573; 5,041,230; 4,909,962; 4,115,061; 4,886,615; 4,139,475; 4,849,257; 5,112,358; 4,659,496; 4,806,254; 5,213,624; 4,130,392; and 4,395,261. Sheet substrates for use in a laundry dryer are disclosed in Canadian 1,005,204. U.S. 3,956,556 and 4,007,300 relate to perforated sheets for fabric conditioning in a clothes dryer. U.S. 4,692,277 discloses the use of 1,2-octanediol in liquid cleaners. Multifunctional Sulfonated Polymers for Household AppUcations are disclosed by Guth, et al., in happi, December, 1994, beginning at page 105. See also U.S. Patents 3,591,510; 3,737,387 3,764,544; 3,882,038; 3,907,496; 4,097,397; 4,102,824; 4,336,024; 4,606,842; 4,758,641 4,797,310; 4,802,997; 4,943,392; 4,966,724; 4,983,317; 5,004,557; 5,062,973; 5,080,822 5,173,200; EP 0 213 500; EPO 261 718; G.B. 1,397,475; WO 91/09104; WO 91/13145; WO 93/25654 and Hunt, D.G. and N.H. Morris, "PnB and DPnB Glycol Ethers", HAPPL April 1989, pp. 78-82.

SUMMARY OF THE INVENTION The present invention encompasses a dry cleaning and spot removal composition, comprising:

(a) at least about 0.5%, by weight, of an anionic anti-static agent;

(b) from about 1% to about 30%, by weight, of an organic solvent;

(c) optionally, but preferably, at least about 0.01%, typically from about 0.01% to about 0.20%, by weight, of a polyacrylate emulsifier,

(d) optionally, from about 0.05% to about 5%, by weight, of detersive surfactants; and

(e) water.

The anionic anti-static agent used herein is preferably a multi-functional sulfonated polymer which is film forming on fabric surfaces and effective at dispersing the static electrical charges which cause fabric "cling". Preferred anti-static agents herein are water-soluble sulfonated polymers, especially members selected from the group consisting of sulfonated polystyrene and copolymers of sulfonated polystyrene with unsaturated monomers.

The organic solvent used herein is preferably a member selected from the group consisting of butoxy propoxy propanol (BPP; preferred herein), methoxy propoxy propanol (MPP), ethoxy propoxy propanol (EPP), propoxy propoxy propanol (PPP), and mixtures and all isomers thereof, although other water-insoluble solvents may be used. The polyacrylate emulsifier preferred for use herein is available commercially from a variety of sources, and preferably has a molecular weight in the range from about 100,000 to about 10,000,000.

The compositions herein optionally can also comprise a detersive surfactant which is preferably a member selected from the group consisting of amine oxides, alkyl ethoxy sulfates, and mixtures thereof. The alkyl ethoxy sulfate surfactants are preferably in their magnesium salt form. In yet another mode, the compositions herein additionally comprise at least about 0.05%, by weight, of 1,2-octanediol as a highly preferred wetting agent

The invention also encompasses a method for cleaning fabrics, comprising applying to said fabrics a composition according to the present invention, and especially wherein said method is conducted in a hot air clothes dryer.

The invention also encompasses an article for cleaning fabrics, comprising a carrier, preferably an integral carrier, releasably containing an amount of the cleaning and anti-static composition herein sufficient to clean a designated load of soiled fabrics, i.e., typically from about 5- 50 grams of composition per kilogram of fabrics. All percentages, ratios and proportions herein are by weight, unless otherwise specified.

All documents cited are, in relevant part, incorporated herem by reference. DETAILED DESCRIPTION OF THE INVENTION The ingredients of the dry cleaning compositions and their use in the process ofthe present invention are described seriatim hereinafter. 1 ??™ 11 ^ Compositions - The chemical compositions which are used to provide the cleaning function in the present dry cleaning process comprise ingredients which are safe and effective for their intended use. Since the process herein does not involve an aqueous rinse step, the cleaning compositions employ ingredients which do not leave undesirable residues on fabrics when employed in the manner disclosed herein. Moreover, since the process may be carried out in a hot air clothes dryer, the compositions contain only ingredients whose flash points render them safe for such use. The cleaning compositions preferably do contain some water, since water not only aids in the cleaning function, but also can help remove wrinkles and restore fabric drape and appearance,

especially in hot air dryers. While conventional laundry detergents are typically formulated to provide good cleaning on cotton and cotton/polyester blend fabrics, the cleaning compositions herein must be formulated to safely and effectively clean and refresh fabrics such as wool, silk, rayon, rayon acetate, and the like. In addition, the cleaning compositions herein comprise ingredients which are specially selected and formulated to minimi y -e dye removal from the fabrics being cleaned. In this regard, it is recognized that the solvents typically used in immersion dry cleaning processes can remove some portion of certain types of dyes from certain types of fabrics. However, such removal is tolerable in immersion processes since the dye is removed relatively uniformly across the surface of the fabric. In contrast it has now been determined that high concentrations of certain types of cleaning ingredients at specific sites on fabric surfaces can result in unacceptable localized dye removal. The preferred cleaning compositions herein are formulated to minimize or avoid this problem

The dye removal attributes of the present cleaning compositions can be compared with art- disclosed cleaners using photographic or photometric measurements, or by means of a simple, but effective, visual grading test Numerical score units can be assigned to assist in visual grading and to allow for statistical treatment of the data, if desired. Thus, in one such test a colored garment (typically, silk, which tends to be more susceptible to dye loss than most woolen or rayon substrates) is treated by padding-on cleaner using an absorbent white paper hand towel. Hand pressure is applied, and the amount of dye which is transferred onto the white towel is assessed visually. Numerical units ranging from: (1) "I think I see a little dye on the towel"; (2) "I know I see some dye on the towel"; (3) I see a lot of dye on the towel"; through (4) "I know I see quite a lot of dye on the towel" are assigned by panelists.

Having due regard to the foregoing considerations, the following illustrates the ingredients used in the cleaning compositions herein, but is not intended to be limiting thereof. (a) Anti-static Agent - The compositions will comprise at least about 0.5%, typically from about 2% to about 8%, by weight of the anionic anti-static agent The objective is to provide at least about 75 mg, preferably from about 100 mg to about

400 mg, of anti-static agent per kilogram of fabrics being cleaned.

(b) Solvent - The compositions will preferably comprise at least about 4%, typically from about 5% to about 25%, by weight ofthe solvent The objective is to provide at least about 0.4 g, preferably from about 0.5 g to about 2.5 g, of solvent per kg of fabrics being cleaned.

(c) Emulsifier - The compositions will preferably comprise sufficient polyacrylate emulsifier to provide a stable, homogeneous composition comprising components (a), (b) and (d). For the emulsifiers disclosed herein, levels as low as 0.05%, preferably 0.07% to about 0.20%, by weight are effective. Levels above about 0.2% are unnecessary and are preferably not used, thereby avoiding residues on

fabrics.

(d) Optionals - The compositions herein may comprise various optional ingredients, including perfumes, certain surfactants, carriers and the like. If used, such optional ingredients will typically comprise from about 0.1% to about 10%, by weight of the compositions, having due regard for residues on the cleaned fabrics.

(e) Water -The compositions will comprise at least about 60%, typically from about 80% to about 95%, by weight of water. Stated otherwise, the objective is to provide at least about 6 g of water per kg of fabrics being cleaned.

The preferred anti-static agents herein are sulfonated polymers. As reported by Guth, et al., ibid, incorporated herein by reference, these materials include, but are not limited to, sulfonated polystyrenes (SPS) having molecular weights in the 100,000-700,000 range and copolymers of sulfonated styrene and maleic anhydride (SSMA), having a molecular weight of about 20,000.

These materials are used herein in their water-soluble, typically sodium salt form. Other, equivalent water-soluble sulfonated polymers, may also be used. The preferred anti-static agents herein are available under the VERSAFLEX trade name from National Starch and Chemical

Company as, for example, VERSAFLEX 157 (SSMA); VERSAFLEX 207 (SSMA); VERSAFLEX

1001 (SPS); VERSAFLEX 2004 (SPS); and VERSAFLEX 7000 (SPS).

The preferred solvent herein is butoxy propoxy propanol (BPP) which is available in commercial quantities as a mixture of isomers in about equal amounts. The isomers, and mixtures thereof, are all useful herein. The isomer structures are as follows. Other useful solvents include methoxy propoxy propanol (MPP), ethoxy propoxy propanol (EPP) and propoxy propoxy propanol

(PPP). The MPP, EPP and PPP solvents also exist as isomers and isomer mixtures, all of which are useful herein. Mixtures ofthese solvents can also be used. n—C 4 H9—O—CH 2 CH 2 CH 2 —O—CH 2 CH 2 CH 2 —OH

H

H BPP is outstanding for cleaning, and is so effective that it allows the amount of the relatively expensive 1,2-octanediol wetting agent noted hereinafter to be minimized. Moreover, it allows for the formulation of effective cleaning compositions herein without the use of conventional surfactants. Importantly, the odor of BPP is of a degree and character that it can be relatively easily masked by conventional perfume ingredients. While BPP is not completely miscible with water and, hence, could negatively impact processing of the cleaning compositions herein, that potential

problem is successfully overcome by means of the PEMULEN-type polyacrylate emulsifiers, in the manner disclosed hereinafter.

It has now been determined that 1,2-octanediol ("OD") affords special advantages in the formulation of the cleaning compositions herein. From the standpoint of aesthetics, OD is a relatively innocuous and low odor material. Moreover, OD appears to volatilize from fabric surfaces without leaving visible residues. This is especially important in a dry cleaning process of the present type which is conducted without a rinse step. From the performance standpoint OD appears to function both as a solvent for greasy/oily stains and as what might be termed a "pseudo-surfactant" for particulate soils and water-soluble stains. Whatever the physical-chemical reason, OD has now been found to be a superior wetting agent with respect to both cleaning and ease-of-use in the present context of home-use cleaning compositions and processes. If used, OD will comprise at least about 0.05%, typically from about 0.1% to about 1.5%, by weight of the cleaning compositions herein.

The BPP solvent used herein is preferably a mixture ofthe aforesaid isomers. In a preferred mode, the cleaning compositions comprise a mixture ofthe 1,2-octanediol and BPP, at a weight ratio of OD:BPP in the range of from about 1:250 to about 2:1, preferably from about 1:200 to about 1:5. Similar ratios can be used with the MPP, EPP and PPP solvents.

The highly preferred emulsifier herein is commercially available under the trademark PEMULEN, The B. F. Goodrich Company, and is described in U.S. Patents 4,758,641 and 5,004,557, incorporated herein by reference. PEMULEN polymeric emulsifiers are high molecular weight polyacrylic acid polymers. The structure of PEMULEN includes a small portion that is oil- loving (lipophilic) and a large water-loving (hydrophilic) portion. The structure allows PEMULEN to function as a primary oil-in-water emulsifier. The lipophilic portion adsorbs at the oil-water interface, and the hydrophilic portion swells in the water forming a network around the oil droplets to provide emulsion stability. An important advantage for the use of such polyacrylate emulsifiers herein is that cleaning compositions can be prepared which contain solvents or levels of solvents that are otherwise not soluble or readily miscible with water. A further advantage is that effective emulsification can be accomplished using PEMULEN-type emulsifier at extremely low usage levels (0.05-0.2%), thereby minimizing the level of any residue left on fabrics following product usage. For comparison, typically about 3-7% of conventional anionic or nonionic surfactants are required to stabilize oil-in-water emulsions, which increases the likelihood that a residue will be left on the fabrics. Another advantage is that emulsification (processing) can be accomplished effectively at room temperature.

Importantly, the anionic anti-static agents in the manner of this invention are compatible with the anionic PEMULEN-type emulsifiers. This allows for the formulation of stable, effective anti-stat/cleaning compositions . In contrast, the use of conventional cationic anti-static agents would presumably result in undesirable interactions with the anionic emulsifier.

While the cleaning compositions herein function quite well with only the anti-static agent BPP, PEMULEN, 1,2-octanediol and water, they may also optionally contain detersive surfactants to further enhance their cleaning performance. While a wide variety of detersive surfactants such as the C j 2-Ci6 alkyl sulfates and alkylbenzene sulfonates, the C^-C j g ethoxylated (EO 0.5-10 avg.) alcohols, the C 12 -Ci4 N-methyl glucamides, and the like can be used herein, it is highly preferred to use surfactants which provide high grease/oil removal. Included among such preferred surfactants are the C12-C16 alkyl ethoxy sulfates (AES), especially in their magnesium salt form, and the Cι 2 - i6 dimethyl amine oxides. An especially preferred mixtures comprise MgAEjS/MgAE^ .5S/C12 dimethyl amine oxide, at a weight ratio of about 1:1:1, and MgAE j S/Ci^ dimethyl amine oxide at a 2:1 weight ratio. If used, such surfactants will typically comprise from about 0.05% to about 2.5%, by weight ofthe cleaning compositions herein.

In addition to the preferred ingredients disclosed above, the cleaning compositions herein may comprise various other optional ingredients, such as perfumes, preservatives, co-solvents, brighteners, salts for viscosity control pH adjusters or buffers, anti-static agents, softeners, colorants, mothproofing agents, insect repellents, and the like.

Carrier - When used in a dry cleaning operation, the cleaning compositions are preferably used in combination with a carrier, such that the cleaning composition performs its function as the surfaces ofthe fabrics being cleaned come in contact with the surface ofthe carrier.

The carrier can be in any desired form, such as powders, flakes, shreds, and tbe like. However, it will be appreciated that such comminuted carriers would have to be separated from the fabrics at the end of the cleaning process. Accordingly, it is highly preferred that the carrier be in the form of an integral pad or sheet which substantially maintains its structural integrity throughout the cleaning process. Such pads or sheets can be prepared, for example, using well-known methods for manufacturing non-woven sheets, paper towels, fibrous batts, cores for bandages, diapers and catamenials, and the like, using materials such as wood pulp, cotton, rayon, polyester fibers, and mixtures thereof. Woven cloth pads may also be used, but are not preferred over non-woven pads due to cost considerations. Integral carriers may also be prepared from natural or synthetic sponges, foams, and the like.

The carriers are designed to be safe and effective under the intended operating conditions of the present process. The carriers must not be flammable during the process, nor should they deleteriously interact with tbe cleaning composition or with the fabrics being cleaned. In general, non-woven polyester-based pads or sheets are quite suitable for use as the carrier herein.

The carrier used herein is most preferably non-linting. By "non-linting" herein is meant a carrier which resists the shedding of visible fibers or microfibers onto the fabrics being cleaned, i.e., the deposition of what is known in common parlance as "lint". A carrier can easily and adequately be judged for its acceptability with respect to linting by rubbing it on a piece of dark blue woolen cloth and visually inspecting the cloth for lint residues.

The non-linting sheet or pad carriers used herein can be prepared by several means, including but not limited to: preparing the carrier from a single strand of fiber, employing known bonding techniques commonly used with nonwoven materials, e.g., point bonding, print bonding, adhesive resin saturation bonding, adhesive/resin spray bonding, stitch bonding and bonding with binder fibers. In an alternate mode, a carrier can be prepared using an absorbent core, said core being made from a material which, itself, may shed lint The core is then enveloped within a sheet of porous, non-linting material having a pore size which allows passage of the cleaning compositions, but through which lint from the core cannot pass. An example of such a carrier comprises a cellulose or polyester fiber core enveloped in a non-woven polyester scrim. The carrier should be of a size which provides sufficient surface area that effective contact between the surface ofthe carrier and the suiface ofthe fabrics being cleaned is achieved. Of course, the size ofthe carrier should not be so large as to be unhandy for the user. Typically, the dimensions of the carrier will be sufficient to provide a macroscopic surface area (both sides of the carrier) of at least about 360 cm 2 , preferably in the range from about 360 cm 2 to about 3000 cm 2 . For example, a rectangular carrier may have the dimensions (x-direction) of from about 20 cm to about 35 cm, and (y-direction) of from about 18 cm to about 45 cm.

The carrier is intended to contain a sufficient amount of the cleaning composition to be effective for its intended purpose. The capacity ofthe carrier for the cleaning composition will vary according to the intended usage. For example, carrier/cleaning composition pads or sheets which are intended for a single use will require less capacity than such pads or sheets which are intended for multiple uses. For a given type of carrier the capacity for the cleaning composition will vary mainly with the thickness or "caliper" (z-direction; dry basis) of the sheet or pad. For purposes of illustration, typical single-use polyester sheets used herein will have a thickness in the range from about OJ mm to about 0.7 mm and a basis weight in the range from about 30 g/m 2 to about 100 g/m 2 . Typical multi-use polyester pads herein will have a thickness in the range from about 0.2 mm to about 1.0 mm and a basis weight in the range from about 40 g/m 2 to about 150 g/m 2 . Open-cell sponge sheets will range in thickness from about OJ mm to about 1.0 mm. Of course, the foregoing dimensions may vary, as long as the desired quantity of the cleaning composition is effectively provided by means of the carrier. The preferred carrier herein comprises a binderless (or optional low binder), hydroentangled absorbent material, especially a material which is formulated from a blend of cellulosic, rayon, polyester and optional bicomponent fibers. Such materials are available from Dexter, Non-Wovens Division, The Dexter Corporation as HYDRASPUN®, especially Grade 10244. The manufacture of such materials forms no part αf this invention and is already disclosed in the literature. See, for example, U.S. Patents 5,009,747, Viazmensky, et al., April 23, 1991 and 5,292,581, Viazmensky, et al., March 8, 1994, incorporated herein by reference. Preferred materials for use herein have the following physical properties.

Grade Optional

10244 Tarf s Ran e

Basis Weight gm/m 2 55 35-75

Thickness microns 355 100-1500

Density gm/cc 0J55 0J-0.25

Dry Tensile gm/25 mm

MD 1700 400-2500

CD 650 100-500

Wet Tensile gm/25 mm

MD* 700 200-1250

CD* 300 100-500

Brightness % 80 60-90

Absorption Capacity % 735 400-900 (H 2 0)

Dry Mullen gm/cm^ 1050 700-1200

MD - machine direction; CD - cross direction

As disclosed in U.S. 5,009,747 and 5,292,281, the hydroentangling process provides a nonwoven material which comprises cellulosic fibers, and preferably at least about 5% by weight of synthetic fibers, and requires less than 2% wet strength agent to achieve improved wet strength and wet toughness.

In addition to the improved cleaning performance, it has now been discovered that the hydroentangled carrier material used herein provides an additional, unexpected benefit due to its resiliency. In-use, the dry cleaning sheets herein are designed to function in a substantially open configuration. However, the sheets are packaged and sold to the consumer in a folded configuration. It has been discovered that carrier sheets made from conventional materials tend to undesirably revert to their folded configuration in-use. This undesirable attribute can be overcome by perforating such sheet, but this requires an additional processing step. It has now been discovered that the hydroentangled materials used to form the carrier sheet herein do not tend to re-fold during use, and thus do not require such perforations (although, of course, perforations may be used, if desired). Accordingly, this newly-discovered and unexpected attribute ofthe preferred carrier materials herein makes them optimal for use in the manner of the present invention.

Container - The present cleaning process is conducted using a flexible container. The fabrics to be cleaned are placed within the container with the carrier/cleaning composition article, and the container is agitated, thereby providing contact between the carrier/cleaning composition and the surfaces cf the fabrics.

The flexible container used herein can be provided in any number of configurations, and is conveniently in the form of a flexible pouch, or "bag", which has sufficient volume to contain the fabrics being cleaned. Suitable containers can be manufactured from any economical material, such

as polyester, polypropylene, and the like, with the proviso that it must not melt if used in contact with hot dryer air. It is preferred that the walls of the container be substantially impermeable to water vapor and solvent vapor under the intended usage conditions. It is also preferred that such containers be provided with a sealing means which is sufficiently stable to remain closed during the cleaning process. Simple tie strings or wires, various snap closures such as ZIP LOK® closures, and

VELCRO®-type closures, contact adhesive, adhesive tape, zipper-like closures, and the like, suffice.

The container can be of any convenient size, and should be sufficiently large to allow tumbling of the container and fabrics therein, but should not be so large as to interfere with the operation of the tumbling apparatus. With special regard to containers intended for use in hot air clothes dryers, the container must not be so large as to block the air vents. If desired, the container may be small enough to handle only a single shirt, blouse or sweater, or be sufficiently large to handle a man's suit

Process - The present cleaning process can be conducted in any manner which provides mechanical agitation, such as a tumbling action, to the container with the fabrics being cleaned. If desired, the agitation may be provided manually. However, in a convenient mode a container with the carrier/cleaning composition and enveloping the soiled fabric is sealed and placed in the drum of an automatic clothes dryer. The drum is allowed to revolve, which imparts a tumbling action to the container and agitation of its contents concurrently with the tumbling. By virtue of this agitation, the fabrics come in contact with the carrier releasably containing and carrying the cleaning composition. The composition is released to the fabrics by contact with the carrier. It is preferred that heat be employed during the process. Of course, heat can easily be provided in a clothes dryer.

The tumbling and optional (but preferred) heating is carried out for a period of at least about 10 minutes, typicaUy from about 20 minutes to about 30 minutes. The process can be conducted for longer or shorter periods, depending on such factors as the degree and type of soiling of the fabrics, the nature (rf the soils, the nature of the fabrics, the fabrw load, the amount of heat applied, and the like, according to the needs ofthe user. The following illustrates a typical process in more detail, but is not intended to be limiting thereof.

EXAMPLE I A dry cleaning article in sheet form is assembled using a sheet substrate and a cleaning composition prepared by admixing the following ingredients.

Ingredient % (wt)

SPS 1 (100% solids basis) 2.0%

PEMULEN TR-l 2 0J5

BPP 3 7.0 1,2-octanediol 0.5

Surfactant Mixture 4 0.50

KOH 0.08

Perfume 0.75

Water and Minors 5 Balance

Sulfonated polystyrene available as VERSAFLEX 1001 from National Starch. 2 PEMULEN TR-2, B. F. Goodrich, may be substimted. 3 Isomer mixture, available from Dow Chemical Co. Mixture of MgAEjS, MgAEg 5S and Cj2 amine oxide, in the range of 1:1:1 to 0.5:1:1. A 1:1 to 2:1 mixture αf MgAEjS/C^ amine oxide can also be used. ^Includes preservatives such as KATHON®.

A non-linting carrier is prepared using stock HYDRASPUN® Grade 10244 fabric, described above. The fabric is cut into carrier sheets, approximately 9 in. (22.9 cm) x 10 in. (25.4 cm), i.e., 580.6 cm 2 sheets.

23 Grams of the above-noted cleaning composition are evenly applied to the sheet by spreading onto the sheet with a roller or spatula using hand pressure. In an alternative mode, the cleaning composition can be applied by dipping or spraying the composition onto the substrate, followed by squeezing with a roller or pair αf nip rollers, i.e., by "dip-squeezing" or "spray squeezing". The external surfaces of the sheet are damp but not tacky to the touch.

A dry cleaning sheet of the foregoing type is unfolded and placed flat in a plastic bag having a volume of about 25,000 cm 3 together with about 2 kg of dry gaπnents to be cleaned. The bag is closed, sealed and placed in a conventional hot-air clothes dryer. When the garments and the dry cleaning sheet are placed in the bag, the air is preferably not squeezed out of the bag before closing and sealing. This allows the bag to billow, thereby providing sufficient space for the fabrics and cleaning sheet to tumble freely together. The dryer is started and the bag is tumbled for a period of 20-30 minutes at a dryer air temperature in the range from about 50°C to about 85°C. During this time, tbe dry cleaning sheet remains substantially in the desired open position, thereby providing effective contact with the fabrics. After the machine cycle is complete, the bag and its contents are removed from the dryer, and the spent dry cleaning sheet is discarded. The plastic bag is retained for re-use. The garments are cleaned, refreshed, and substantially free from static electricity. The water present in the cleaning composition serves to minimize wrinkles in the fabrics.

In an alternate mode, heavily soiled areas of the fabric being cleaned can optionally be pre- treated by pressing or rubbing a fresh dry cleaning sheet according to this invention on the area. The sheet and pre-treated fabric are then placed in the container, and the dry cleaning process is conducted in the manner described herein.

The compositions prepared in the manner of this invention can also be directly applied to isolated spots and stains on fabrics in the manner of a spot remover product The following illustrates this aspect of the invention, but is not intended to be limiting thereof.

EXAMPLE π A spot remover composition comprises the following:

Ingredients % (wU

SSMA (100% solids basis)* 1.0

PEMULEN 0J5

BPP** 7.0 1,2- ctanediol 0.5

Perfume 0.75

Water Balance

Sulfonated styrene/maleic anhydride, available as VERSAFLEX 207 from National Starch. ♦♦ May be replaced by an equivalent amount of MPP, EPP and PPP, respectively, or mixtures thereof, and mixtures thereof with BPP.

The composition is directly padded or sprayed onto spots and stains, followed by nibbing, to effect their removal. In an alternate mode, the composition can be gelled or thickened using conventional ingredients to provide a "stick-form" spot remover. Spot-cleaned fabrics can then be placed in a container together with a sheet containing about 20 g of the foregoing conφosition and tumbled in an automatic clothes dryer in the manner of Example I. The fabrics are cleaned, refreshed and are substantially free of static.

Having thus described and exemplified the present invention, the following further illustrates various cleaning compositions which can be formulated and used in the practice thereof.

EXAMPLE m Ingredient % (wt) Formula Range

Anionic Anti-stat 0.5-15%

BPP* 5-25%

1,2-Octanediol 0.1-7%

M AE^ 0.01-0.8% MgAEg S 0.01-0.8%

C 12 Dimethyl Amine Oxide 0.01-0.8%

PEMULEN** 0.05-0.20%

Perfume 0.01-1.5%

Water Balance pH Range from about 6 to about 8.

May be replaced by MPP, EPP or PPP, respectively. Other co-solvents which can be used herein together with the BPP, MPP, EPP and PPP primary solvents include various glycol ethers, including materials marketed under trademarks such as CarbitoL methyl CarbitoL butyl Carbitol, propyl CaibitoL hexyl Cellosolve, and the like. If desired, and having due regard for safety and odor for in- home use, various conventional chlorinated and hydrocarbon dry cleaning solvents may also be used. Included among these are 1,2-dichloroethane, trichloroethylene, isoparaffins, and mixtures thereof. ♦♦ As disclosed in U.S. Patents 4,758,641 and 5,004,557, such polyacrylates include homopolymers

which may be crosslinked to varying degrees, as weU as non-crosslinked. Prefeπed herein are homopolymers having a molecular weight in the range of from about 100,000 to about 10,000,000, preferably 200,000 to 5,000,000.

ExceUent cleaning performance is secured using any of the foregoing non-immersion processes and articles to provide from about 5 g to about 50 g of the cleaning compositions per kilogram of fabric being cleaned. Use of the polyacrylate emulsifier at the indicated low levels minimizes residues on the fabrics.

EXAMPLE TV A dry cleaning composition with reduced tendency to cause dye "bleeding" or removal from fabrics as disclosed above is as foUows. The composition is fully compatible with tbe anti-static agents disclosed above.

INGREDIENT PERCENT (wt (RANGE)

Butoxypropoxy propanol (BPP) 7.000 4.0 - 25.0%

NEODOL 23 - 6.5* 0.750 0.05 - 2.5% 1,2-Octanediol 0.500 OJ - 10.0%

Perfume 0.750 OJ - 2.0%

Pemulen TR-l 0J25 0.05 - 0.2%

Potassium Hydroxide (KOH) 0.060 0.024 - 0J0

Potassium Chloride 0.075 0.02 - 0.20 Water (distiUed or deionized) 90.740 60.0 - 95.0%

Target pH = 7.0

SheU; alcohol, ethoxylated with average EO of 6.5.

15-25 Grams of composition o the foregoing type and containing the anti-static agent are placed on a carrier sheet for use in the manner disclosed herein. A preferred carrier substrate comprises a binderless (or optional low binder), hydroentangled absorbent material, especiaUy a material which is formulated from a blend αf ceUulosic, rayon, polyester and optional bicomponent fibers. Such materials are available from Dexter, Non-Wovens Division, The Dexter Corporation as

HYDRASPUN®, especiaUy Grade 10244. The manufacture αf such materials forms no part of this invention and is already disclosed in the literature. See, for example, U.S. Patents 5,009,747, Viazmensky, et al., April 23, 1991 and 5,292,581, Viazmensky, et al., March 8, 1994, incorporated herein by reference. Preferred materials for use herein have the foUowing physical properties.

Grade Optional

10244 Tar ets Range

Basis Weight gm/m 2 55 35-75 Thickness microns 355 100-1500 Density gm/cc 0J55 0J- .25 Dry Tensile gm/25 mm

MD 1700 400-2500

CD 650 100-500 Wet Tensile gm/25 mm

MD* 700 200-1250

CD* 300 100-500 Brightness 80 60-90 Absorption Capacity 735 400-900(H 2 0) Di MuUen gm/cm 2 1050 700-1200

MD - machine direction; CD - cross direction As disclosed in U.S. 5,009,747 and 5,292,281, the hydroentangling process provides a nonwoven material which comprises ceUulosic fibers, and preferably at least about 5% by weight of synthetic fibers, and requires less than 2% wet strength agent to achieve improved wet strength and wet toughness.

Surprisingly, this hydroentangled carrier is not merely a passive absorbent for the cleaning compositions herein, but actuaUy optimizes cleaning performance. While not in en ing to be limited by theory, it may be speculated that this carrier is more effective in delivering the cleaning conφosition to soUed fabrics. Or, this particular carrier might be better for removing soils by contact with the soUed fabrics, due to its mixture of fibers. Whatever the reason, improved dry cleaning performance is secured. In addition to the improved cleaning performance, it has now been discovered that this hydroentangled carrier material provides an additional, unexpected benefit due to its resiliency. In- use, the dry cleaning sheets herein are designed to function in a substantiaUy open configuration. However, the sheets are packaged and sold to the consumer in a folded configuration. It has been discovered that carrier sheets made from conventional materials tend to undesirably revert to their folded configuration in-use. This undesirable attribute can be overcome by perforating such sheet but this requires an additional processing step. It has now been discovered that the hydroentangled matwi- j l g used to form the carrier sheet herein do not tend to re-fold during use, and thus do not require such perforations (although, of course, perforations may be used, if desired). Accordingly, this newly-discovered and unexpected attribute ofthe carrier materials herein makes them optimal for use in the manner ofthe present invention.

A sheet of the foregoing type is placed together with the fabrics to be dry cleaned in a flexible containment bag having dimensions as noted hereinabove and sealing means. In a preferred mode, the containment bag is constructed of thermal resistant film in order to provide resistance to hot spots (350°F-400°F; 177°C to 204°C) which can develop in some dryers. This avoids internal self-sealing and external surface deformation of the bag, thereby aUowing the bag to be re-used.

In a preferred embodiment 0.0025 mm to 0.0075 mm thickness nylon film is converted

into a 26 inch (66 cm) x 30 in. (76 cm) bag. Bag manufacture can be accomplished in a conventional manner using standard impulse heating equipment air blowing techniques, and the like. In an alternate mode, a sheet of nylon is simply folded in half and sealed along two of its

In addition to thermally stable "nylon-only" bags, the containment bags herein can also be prepared using sheets of co-extruded nylon and/or polyester or nylon and/or polyester outer and/or inner layers surrounding a less theπnaUy suitable inner core such as polypropylene. In an alternate mode, a bag is constructed using a nonwoven outer "shell" comprising a heat-resistant material such as nylon or polyethylene terephthalate and an inner sheet of a polymer which provides a vapor barrier. The non-woven outer sheU protects the bag from melting and provides an improved tactile impression to the user. Whatever the construction, the objective is to protect the bag's integrity under conditions of thermal stress at temperatures up to at least about 400-500 (204°C to 260°C). Nylon VELCRO®-type, ZIP-LOK®-type and/or zipper-type closures can be used to seal the bag, in- use. Besides the optional nonionic surfactants used herein, which are preferably Cg-C j g ethoxylated (E01-15) alcohols or the corresponding ethoxylated alkyl phenols, the compositions used herein can contain enzymes to fiirther enhance cleaning performance. Lipases, amylases and protease enzymes, or mixtures thereof, can be used. If used, such enzymes wiU typicaUy comprise from about 0.001% to about 5%, preferably from about 0.01% to about 1%, by weight of the composition. Commercial detersive enzymes such as LIPOLASE, ESPERASE, ALCALASE, SAVINASE and TERMAMYL (all ex. NOVO) and MAXATASE and RAPTDASE (ex. International Bio-Synthesis, Inc.) can be used.

The compositions herein can optionaUy be stabilized for storage using conventional preservatives such as KATHON® at a level of 0.001%-1%, by weight If the compositions herein are used in a spot-cleaning mode, they are preferably pressed

(not rubbed) onto the fabric at the spotted area using an appUcator pad comprising looped fibers, such as is available as APLDC 200 or 960 Uncut Loop, from Aplix, Inc., Charlotte, NC. An underlying absorbent sheet or pad αf looped fibers can optionaUy be placed beneath the fabric in this mode of operation.