WO1999046319A1

WO1999046319A1 - Abrasion resistant polymeric foam and stain receivers made therefrom

Info

Publication number: WO1999046319A1
Application number: PCT/US1999/005460
Authority: WO
Inventors: Timothy Clair Roetker; Thomas Allen Desmarais; Bruce Albert Yeazell
Original assignee: The Procter & Gamble Company
Priority date: 1998-03-13
Filing date: 1999-03-12
Publication date: 1999-09-16
Also published as: CN1300306A; JP2002506100A; CA2323875A1; BR9909245A; EP1064321A1

Abstract

An abrasion resistant stain receiver made of polymeric foam wherein the polymeric foam is produced from an oil and water emulsion, wherein the oil phase of the emulsion comprises at least about 30 % by weight of a toughening monomer selected from the group consisting of styrene, ethyl styrene and mixtures thereof. Preferably, the abrasion resistant stain receiver contains a cross-linking monomer selected from the group consisting of divinyl benzene, hexane diacrylate and mixtures thereof, wherein the weight ratio of toughening monomer to cross-linking monomer in the oil phase of the emulsion is greater than about 1:1. The polymeric foam resists flaking when used as a stain receiver in a fabric stain removal operation.

Description

ABRASION RESISTANT POLYMERIC FOAM AND STAIN RECEIVERS MADE THEREFROM

FIELD OF THE INVENTION

The present invention relates to an improved foam stain receiver that is used to spot-clean fabrics and that is abrasion resistant.

BACKGROUND OF THE INVENTION

Fabric cleaning and refreshment processes such as laundering and dry cleaning operations typically are used to clean entire garments. However, in some circumstances the user wishes only to clean localized areas of fabrics. Alternatively, the user may wish to spot-clean localized areas of stain before subjecting the entire fabric garment to an overall dry cleaning or laundering operation.

It has been determined that certain absorbent polymeric foam materials are especially useful in spot cleaning operations. These polymeric foams are prepared from High Internal Phase Emulsions (hereafter referred to as "HIPEs")- See, for example, U.S. Patent No. 5,260,345 (DesMarais et al.) issued November 9, 1993, U.S. Patent No. 5,268,224 (DesMarais et al.) issued December 7, 1993, DYER '207 and DESMARAIS '222 (each of which is incorporated herein by reference), which generally describe HIPE-derived polymeric foams. In a typical operation, the polymeric foam functions as a "stain receiver" by drawing the liquid cleaning composition through the stained/spotted area of the fabric. Thus, the stain/spot material which has been mobilized by the cleaning composition is captured in the polymeric foam. Importantly, the polymeric foam minimizes the tendency of the stain/spot to spread laterally on the fabric, thereby minimizing the formation of "rings" on the fabric.

In a preferred spot cleaning operation, a polymeric foam stain receiver is positioned beneath a stained area of fabric. A cleaning composition is then applied to the stain and worked into the stain by mechanical action. Such mechanical action preferably comprises using compressional, mainly Z-directional force in the manner disclosed herein. It has now been determined that previously described polymeric foam, when used as the stain receiver, may not be sufficiently robust to withstand vigorous forces encountered during the cleaning operation. Simply stated, the polymeric stain receiver may be sufficiently friable under mechanical force that it may begin to disintegrate, with the result that the polymeric foam flakes off. This results in a messy appearance in the area where the spot cleaning process is being conducted. Moreover, the polymeric foam flakes may be undesirably transferred to the fabric being spot-cleaned.

One method of overcoming the problems associated with prior foam stain receivers is disclosed in U.S. Provisional Application No.60/053, 191. This application is directed to a polymeric foam stain receiver enrobed in a coversheet. While this method of protecting the polymeric foam is effective, it adds costs and processing steps to the manufacturing of stain receivers. Hence, there is a continuing need for improved polymeric foam stain receivers that resist abrasion whereby they do not flake or disintegrate during use.

Having discovered the problems associated with polymeric foam when used in the present manner, the invention herein employs a new composition for the polymeric stain receiver, thereby minimizing such problems.

BACKGROUND ART

WO 97/00993 Al, published January 9, 1997 to Weller, et al.; WO 97/00990A2, published January 9, 1997 to Tyerech, et al.; GB 2,302,553A, published January 22, 1997 to Telesca, et al.; GB 2,302,878A, published February 5, 1997 to Weller, et al.; and GB 2,302,879A, published February 5, 1997 to Sidoti, et al. all relate to in-dryer fabric cleaning. U.S. 4,532,722, issued to S. H. Sax, August 6, 1985, relates to a fabric conditioning device for use in a laundry dryer. A peracid-containing dry cleaning composition is described in U.S. 4,013,575, issued to H. Castrantas, et al., March 22, 1977. Dry cleaning processes are disclosed in: U.S. 5,547,476 issued 8/20/96 to Siklosi & Roetker; U.S. 5,591,236 issued 1/7/97 to Roetker; U.S. 5,630,847 issued 5/20/97 to Roetker; U.S. 5,630,848 issued 5/20/97 to Young, et al.; U.S. 5,632,780 issued 5/27/97 to Siklosi; EP 429,172A1, 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. 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; 4,594,362; 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; EP0 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", HAPPI. April 1989, pp. 78-82.

SUMMARY OF THE INVENTION The present invention encompasses a polymeric foam and an abrasion resistant stain receiver comprising polymeric foam, wherein the polymeric foam comprises a polymerized water- in-oil emulsion having:

1) an oil phase comprising: a) from about 85 to about 98% by weight of a monomer component, said monomer component comprising: i) from about 25 to about 70% by weight of a substantially water-insoluble, monofunctional monomer capable of forming a polymer having a Tg of about 25°C or less; ii) from about 25 to about 65% by weight of a substantially water-insoluble, monofunctional comonomer capable of imparting toughness about equivalent to that provided by styrene; iii) from about 5 to about 25% by weight of a first substantially water- insoluble, polyfunctional crosslinking agent selected from the group consisting of divinylbenzenes, trivinylbenzenes, divinyltoluenes, divinylxylenes, divinylnaphthalenes divinylalkylbenzenes, divinylphenanthrenes, divinylbiphenyls, divinyldiphenylmethanes, divinylbenzyls, divinylphenylethers, divinyldiphenylsulfides, divinylfurans, divinylsulfide, divinylsulfone, and mixtures thereof; and iv) from 0 to about 15% by weight of a second substantially water-insoluble, polyfunctional crosslinking agent selected from the group consisting of polyfunctional acrylates, methacrylates, acrylamides, methacrylamides, and mixtures thereof; v) wherein the weight ratio of the monofunctional comonomer capable of imparting toughness (ii) to the sum of the first and second polyfunctional crosslinking agents (iii + iv) is at least about 1:1 preferably at least about 2:1, more preferably at least about 3:1, and most preferably at least about 5:1; b) from about 2 to about 15% by weight of an emulsifier component which is soluble in the oil phase and which is suitable for forming a stable water-in-oil emulsion; and

2) a water phase comprising from about 0.2 to about 20% by weight of a water- soluble electrolyte; and

3) a volume to weight ratio of water phase to oil phase of at least about 16:1.

In another mode of the present invention the polymeric foam is produced from an emulsion having a water to oil weight ratio of at least about 16:1, preferably at least about 20:1. In a preferred mode of the present invention the oil phase of the emulsion comprises from about 30 to about 65% of the monofunctional comonomer capable of imparting toughness about equivalent to that provided by styrene

In one convenient mode of this invention, a spot removal process is defined using the following steps:

1. Place the stained area of the fabric over and in fluid-receiving contact with an abrasion resistant stain receiver comprising polymeric foam according to his invention;

2. Apply enough composition, preferably from a bottle with a narrow spout which directs the composition onto the stain (without unnecessarily saturating the surrounding area of the fabric), to saturate the localized stained area - about 10 drops; more may be used for a larger stain.

3. Optionally, allow the composition to penetrate the stain for 3-5 minutes. (This is a pre- treat or pre-hydration step for better cleaning results.)

4. Optionally, apply additional composition - about 10 drops; more may be used for larger stains.

5. Apply mechanical force to the stained area. This can be done, for example, by using the tip of the bottle spout to mechanically manipulate the stain. Alternatively, one can use the spot removal device shown in the Figure to work the stain completely out. Rock the device (i.e. force applied in the downward "Z" direction) firmly against the stain for 20- 120 seconds, longer for tougher stains. Do not rub (i.e., force applied in the side-to-side "X-Y" direction) the stain with the device, since this can harm the fabric.

6. Remove the fabric from contact with the abrasion resistant stain receiver.

7. Optionally, the fabric can be blotted with the abrasion resistant stain receiver, with other polymeric foams and absorbent materials, or between paper towels to remove excess cleaning composition.

In an alternate mode, the cleaning/refreshment composition can be applied to the stain (Step 2 and/or 4) by spraying, daubing or by padding the composition on from a carrier sheet, or by any other convenient means.

All percentages, ratios and proportions herein are by weight, unless otherwise specified. All documents cited are, in relevant part, incorporated herein by reference.

BRIEF DESCRIPTION OF THE DRAWING

Figure 1 illustrates the use of a cleaning device by using hand pressure to rock the device, thereby causing the protuberances which extend outwardly from the arcuate, convex head to impinge on the stained (207) fabric and to impart a cleaning force perpendicular to the stain. The polymeric foam stain receiver (501) according to this invention is shown underlaying the stained area of fabric.

DETAILED DESCRIPTION OF THE INVENTION

The stain receiver used herein comprises polymeric foams which are in the form of water- absorbent foams having a controlled capillary size. The physical structure and resulting high capillarity of polymeric foams provide very effective water absorption, while at the same time the chemical composition of the polymeric foam typically renders it highly lipophilic. Thus, the polymeric foam can essentially provide both hydrophilicity and lipophilicity simultaneously. (The polymeric foams can be treated to render them hydrophilic. Both the hydrophobic or hydrophilic foam can be used herein.)

The acquisition and absorbency of the polymeric foam with respect to the liquid pre- spotting compositions herein is superior to most other types of absorbent materials. For example, the polymeric foam has a capacity of about 6 g (H2O) per gram of foam at a suction pressure of 100 cm of water. By contrast, cellulose wood fiber structures have essentially no capacity above about 80 cm of water. Since, in the present process, the volume of liquid pre-spotter used is relatively low (a few milliliters is typical) the amount of polymeric foam used can be small. This means that the pad of polymeric foam which underlies the stained area of fabric can be quite thin and still be effective.

For pre-spotting, the stained area of the garment or fabric swatch is placed over a section of polymeric foam, followed by treatment with the liquid cleaning solution, preferably in conjunction with force applied using the tip of the dispenser tube to provide mechanical agitation. The mechanical manipulation and the detergency effect of the solution serve to loosen the soil and transfer it through the fabric and into the polymeric foam. While spot cleaning progresses, the suction effects of the polymeric foam's capillaries cause the cleaning solution and stain debris to be carried into the polymeric foam, where the stain debris is largely retained. At the end of this step the stain, as well as almost all of the cleaning solution, is found to have been removed from the fabric being treated and transferred to the polymeric foam. This leaves the fabric surface only damp, with a minimum residue of the cleaning solution/stain debris which can lead to undesirable rings on the fabrics.

The polymeric foams of this invention exhibit superior abrasion resistance when subjected to the mechanical agitation discussed above. As used herein "abrasion resistant" is intended to mean the polymeric foam produces or sheds few or no small flakes that can be transferred to the fabric being treated. "Tearing" as used herein means the polymeric foam is ripped or ruptured by the mechanical force applied during the fabric treatment process. It is important to note that "tearing" and "abrading" are not necessarily related. Abrasion relates to the release of small flakes of polymeric foam which are both unsightly and difficult to remove from fabrics, while tearing typically results in substantial damage to the polymeric foam but does not necessarily impart any undesirable effects to the fabric being treated. For example, a polymeric foam may have excellent abrasion resistance while being prone to tearing. It is generally preferred that the polymeric foams for use in the present invention resist both abrasion and tearing, but the present invention is geared primarily to improving abrasion resistance.

While the composition of the present abrasion resistant polymeric foams, specifically, the weight percentage of toughening monomers and the ratio of toughening monomers to cross-linking monomers, forms an integral part of the present invention, the method of manufacturing the polymeric foam for use as the stain receiver forms no part of this invention. The manufacture of polymeric foam is very extensively described in the patent literature; see, for example: U.S. 5,260,345 to DesMarais, Stone, Thompson, Young, LaVon and Dyer, issued November 9, 1993; U.S. 5,268,224 to DesMarais, Stone, Thompson, Young, LaVon and Dyer, issued December 7, 1993; U.S. 5,147,345 to Young, LaVon and Taylor, issued September 15, 1992 and companion patent U.S. 5,318,554 issued June 7, 1994; U.S. 5,149,720 to DesMarais, Dick and Shiveley, issued September 22, 1992 and companion patents U.S. 5,198,472, issued March 30, 1993 and U.S. 5,250,576 issued October 5, 1993; U.S. 5,352,711 to DesMarais, issued October 4, 1994; PCT application 93/04115 published March 4, 1993, and U.S. 5,292,777 to DesMarais and Stone, issued March 8, 1994; U.S. 5,387,207 to Dyer, DesMarais, LaVon, Stone, Taylor and Young, issued February 7, 1995; U.S. 5,500,451 to Goldman and Scheibel, issued March 19, 1996; and U.S. 5,550,167 to DesMarais, issued August 27, 1996, and U.S. 5,650,222 to DesMarais et al, issued July 22, 1997, all incorporated herein by reference. Typical conditions for forming the polymeric foams of the present invention are described in detail in co-pending U.S.

Patent Application Serial No. , filed March 13, 1998 by T. A. DesMarais, et al. (P&G

Case No. 7051 - titled "ABSORBENT MATERIALS FOR DISTRIBUTING AQUEOUS LIQUIDS"), the disclosure of which is incorporated herein by reference.

Stain receiver pads made of polymeric foam can be used in either of two ways. In one mode, the uncompressed foam is used. Uncompressed polymeric foam pads having a thickness in the range of about 0.3 mm to about 15 mm are useful. In another mode, certain polymeric foams have sufficient capillary forces such that they are stable in the compressed state. Such foams are described in the above-mentioned '207 and '222 patents. These foams can be used in a compressed state and will swell as liquid pre-spotter with its load of stain material is imbibed. In another mode, the Tg of the foam may be much higher than the use temperature and will remain compressed (compositions 2 and 3 in the Table LA). Compressed polymeric foams having thicknesses in the range of about 0.5 mm to about 4.7 mm are suitable herein. The preparation of polymeric foam is described in the patents cited hereinabove. With the exception of the discovered importance of oil phase monomer ratio that provides improved abrasion resistance, the processes described in the cited patents may be used to prepare the present foams. The following Example illustrates the preparation of a compressed foam for use herein. Preparation of Emulsion and Polymeric Foams Therefrom

A) Emulsion Preparation

Anhydrous calcium chloride (36.32 kg) and potassium persulfate (189 g) are dissolved in 378 liters of water. This provides the water phase stream to be used in a continuous process for forming the emulsion.

The oil phase is prepared by mixing at least about 25%, preferably at least about 30%, and most preferably at least about 35% by weight of a toughening monomer selected from the group consisting of styrene, ethyl styrene and mixtures thereof with the other optional ingredients, such as emulsifiers, and crosslinking monomers. Preferably the weight ratio of toughening monomer to cross-linking monomer in the oil phase of the emulsion is greater than about 1:1, preferably greater than about 2: 1, more preferably greater than about 3: 1, and most preferably greater than about 5: 1.

Separate streams of the oil phase (25°C) and water phase (53°-55°C) are fed to a dynamic mixing apparatus. Thorough mixing of the combined streams in the dynamic mixing apparatus is achieved by means of a pin impeller. The pin impeller comprises a cylindrical shaft of about 36.8 cm in length with a diameter of about 2.5 cm. The shaft holds 6 rows of pins, 3 rows having 33 pins and 3 rows having 32 pins, each having a diameter of 0.5 cm extending outwardly from the central axis of the shaft to a length of 2.5 cm. The pin impeller is mounted in a cylindrical sleeve which forms the dynamic mixing apparatus, and the pins have a clearance of 1.5 mm from the walls of the cylindrical sleeve.

A minor portion of the effluent exiting the dynamic mixing apparatus is withdrawn and enters a recirculation zone; see PCT U.S. 96/00082 published 18 July 96 and EPO 96/905110.1 filed 11 January 96. The Waukesha pump in the recirculation zone returns the minor portion to the entry point of the oil and water phase flow streams to the dynamic mixing zone.

The combined mixing and recirculation apparatus set-up is filled with oil phase and water phase at a ratio of 4 parts water to 1 part oil. The dynamic mixing apparatus is vented to allow air to escape while filling the apparatus completely. The flow rates during filling are 7.6 g/sec oil phase and 30.3 cc/sec water phase.

Once the apparatus set-up is filled the vent is closed. Agitation is then begun in the dynamic mixer, with the impeller turning at 650 RPM and recirculation is begun at a rate of about 30 cc/sec. The flow rate of the water phase is then steadily increased to a rate of 151 cc/sec over a time period of about 1 min., and the oil phase flow rate is reduced to 5 g/sec over a time period of about 3 min. The recirculation rate is steadily increased to about 150 cc/sec during the latter time period. The back pressure created by the dynamic mixer and static mixing zone (TAH Industries Model Number 101-212) at this point is about 4 PSI (28 kPa), which represents the total back pressure of the system. The Waukesha pump speed is then steadily decreased to a yield a recirculation rate of about 75 cc/sec.

B) Polymerization of Emulsion

The HIPE flowing from the static mixer at this point is collected in a round polyethylene tub, 40 in. (102 cm) in diameter and 12.5 in (31.8 cm) high, with removable sides, much like a springform pan used in cooking cakes. A pipe-like polyethylene insert 12.5 in (31.8 cm) in diameter at its base is firmly affixed to the center of the base and is 12.5 in (31.8 cm) high. The HIPE-containing tubs are kept in a room maintained at 65° C for 18 hours to bring about polymerization and form the foam.

C) Foam Washing and Dewatering

The cured polymeric foam is removed from the curing tubs. The foam at this point has residual water phase (containing dissolved emulsifiers, electrolyte, initiator residues, and initiator) about 25-35 times (25-35X) the weight of polymerized monomers. The foam is sliced with a sharp reciprocating saw blade into sheets which are 0.185 inches (0.47 cm) in thickness. These sheets are then subjected to compression in a series of 2 porous nip rolls equipped with vacuum which gradually reduce the residual water phase content of the foam to about 6 times (6X) the weight of the polymerized material. At this point, the sheets are then resaturated with a 1.5% CaCl2 solution at 60°C, are squeezed in a series of 3 porous nip rolls equipped with vacuum to a water phase content of about 2X. The CaCl2 content of the foam is between about 3 and 5%.

The foam remains compressed after the final nip at a thickness of about 0.030 in. (0.075 cm). The foam is then dried in air for about 16 hours. Such drying reduces the moisture content to about 9-17 % by weight of polymerized material. At this point, the foam sheets are very drapeable. In this collapsed state, the density of the foam is about 0.14 g/cc. Optionally, a liquid- impermeable backing sheet (e.g., 1 mil. polypropylene) can be applied to the foam pad to prevent liquid strike-through when the pad is being used.

Reinforcing Means - As noted above, for use as a stain receiver in the pre-spotting operation herein, a sheet of the polymeric foam is placed beneath and in close contact with one- side of the stained area of a fabric. A portion of pre-spotting composition is dispensed onto the fabric and manipulated into the stain by mechanical means. The excess pre-spotting composition and its load of stain material are thereby transferred into the underlying polymeric pad. The composition of the present polymeric foams, and specifically, the weight percentage of toughening monomers and the ratio of toughening monomers to cross-linking monomers, substantially improves abrasion resistance and minimizes flaking of the polymeric pad when mechanical agitation is applied thereto. But to further minimize transfer of flakes to the fabric being treated it may be desirable to use reinforcing means comprising a liquid-permeable coversheet that enrobes the polymeric foam sheet and which freely allows passage of the liquid cleaning composition herein through the coversheet and into the foam.

Typical materials used as reinforcing means are as follows.

1. Formed-film material with uniform or "dual" sized holes; see, for example, U.S. Patents 4,324,246; 4,342,314; 4,609,518; and EP 0,165,807 for the manufacture of formed films.

2. Poly-chiffon - 100% polyester woven fabric.

3. 18 grams/meter^ (gsm) spunbonded polyester sheet (Reemay).

4. 18 gsm carded polypropylene sheet.*

5. Women's nylon hosiery - 88% nylon, 12% Lycra® Spandex®

6. Organza - 100% polyester woven fabric.

7. 14 gsm thermally bonded air laid woven made with bicomponent annular fiber - polypropylene inner core with polyethylene outer shell.

^♦Commercially used in disposable absorbent products such as diapers.

The polymeric foam can be encased in the reinforcing means by any convenient process which essentially "wraps" the foam within at least one layer of the reinforcing sheet material. If desired, the polymeric can be only partially encased such that only the uppermost part of the polymeric which is directly impacted by mechanical force during the spot-cleaning operation is abrasion resistant. Since the back of the polymeric may be covered with a liquid impermeable backing sheet, such backing sheet will also provide reinforcement. However, and depending on the type of equipment which is available, it may be simpler to encase the entire polymeric pad.

As noted, the reinforcing means can be applied to the foam pad in any convenient manner. Optionally, the reinforcing means can be held in place by means of adhesives, or the like. Preferably, the reinforcing means is applied in any manner that ensures it is in close contact with the polymeric pad to provide optimum reinforcement.

Compositions - The user of the present process can be provided with various compositions to use as spot removers. One problem associated with known fabric spot remover compositions is their tendency to leave visible residues on fabric surfaces. Such residues are problematic and are preferably to be avoided herein since the present process does not involve conventional immersion or rinse steps. Accordingly, the pre-spotting compositions herein should, most preferably, be substantially free of various polyacrylate-based emulsifiers, polymeric anti-static agents, inorganic builder salts and other residue-forming materials, except at low levels of about 0.1%-0.3%, and preferably 0%, of the final compositions. Stated otherwise the compositions herein should be formulated so as to leave substantially no visible residue on fabrics being treated according to the practice of this invention.

Accordingly, in a preferred aspect of this invention there are provided liquid pre-spotting (i.e., spot-cleaning) compositions which are substantially free of materials which leave visible residues on the treated fabrics. This necessarily means that the preferred pre-spotting compositions are formulated to contain the highest level of volatile materials possible, preferably water, typically about 95%, preferably about 97.7%, a cleaning solvent such as BPP at a low, but effective, level, typically about 1% to about 4%, preferably about 2%, and surfactant at levels of about 0.1 to about 0.7%. Advantageously, when thus formulated such compositions exist as aqueous solutions rather than as suspensions or emulsions. Thus, such compositions do not require use of additional emulsifiers, thickening agents, suspending agents, and the like, all of which can contribute to the formation of undesirable visible residues on the fabric.

Indeed, as an overall proposition, any of the chemical compositions which are used to provide the pre-spotting function herein comprise ingredients which are safe and effective for their intended use, and, as noted above, preferably do not leave unacceptable amounts of visible residues on the fabrics. While conventional laundry detergents are typically formulated to provide good cleaning on cotton and cotton/polyester blend fabrics, the compositions herein must be formulated to also safely and effectively clean and refresh fabrics such as wool, silk, rayon, rayon acetate, and the like. In addition, the compositions herein comprise ingredients which are specially selected and formulated to minimize dye removal or migration from the stain site of fugitive, unfixed dye 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 compositions herein are formulated to minimize or avoid this problem.

The dye removal attributes of the present 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 fabrics) is treated by padding-on cleaner/refresher 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.

In addition to the foregoing considerations, the compositions used herein are preferably formulated such that they are easily dispensed and not so adhesive in nature that they render dispensing from the container to be unhandy or difficult. However, and while not intending to be limiting of the present invention, the preferred compositions disclosed herein afford a spot-cleaning process which is both effective and aesthetically pleasing when used in the manner disclosed herein. Aqueous Spot Stain Cleaning Compositions

(a) Water -The preferred, low residue compositions herein may comprise from about 90%, preferably from about 95.5% to about 99.9%, by weight, of water.

(b) Solvent - The compositions herein may comprise from about 0% to about 10%, by weight, of butoxy propoxy propanol (BPP) solvent or other solvents as disclosed herein. Preferred spot cleaners will comprise 1-4% BPP.

(c) Surfactant - The compositions herein may optionally comprise from about 0.05% to about 2%, by weight, of surfactants, such as MgAES and NH4AES, amine oxides, ethoxylated alcohols or alkyl phenols, alkyl sulfates, and mixtures thereof. The use of surfactants limited to the lower end of the range is preferred for some dyes and fabric types. Typically, the weight ratio of BPP solvent: surfactant(s) is in the range of from about 10: 1 to about 1:1. One preferred composition comprises 2% BPP/0.25% Neodol 23 6.5. Another preferred composition comprises 4% BPP/0.4% AS. A highly preferred composition comprises 2% BPP/0.3% MgAEi S/0.03% dodecyldimethylamine oxide.

(d) Optionals - The compositions herein may comprise minor amounts of various optional ingredients, including bleach stabilizers, perfumes, preservatives, and the like. If used, such optional ingredients will typically comprise from about 0.05% to about 2%, by weight, of the compositions, having due regard for residues on the cleaned fabrics.

(e) Bleach - The compositions herein may also optionally comprise from 0% to about 7%, by weight, of hydrogen peroxide. Preferred spot cleaners will comprise from 0% to about 3% hydrogen peroxide. It will be appreciated that peroxide sources other than H2O2 can be used herein. Thus, various per-acids, per-salts, per- bleaches and the like known from the detergency art can be used. However, such materials are expensive, difficult to formulate in liquid products, can leave residues on fabrics and offer no special advantages over H2O2 when used in the present manner. (f) Chelator - Compositions which contain H2O2 will also typically contain a chelating agent. The chelating agent is selected from those which, themselves, are stable in aqueous H2O2 and which stabilize the H2O2 by chelating vagrant metal ions. Such chelating agents are typically already present at low, peroxide- stabilizing amounts (0.01-1%) in commercial sources of hydrogen peroxide. A variety of phosphonate chelators are known in stabilizing H2O2. The amino phosphonates are especially useful for this purpose. Various amino phosphonates are available as under the DEQUEST® trade name from the Monsanto Company, St. Louis, Missouri. Representative, but non-limiting, examples include ethylenediamine tetrakis (methylene phosphonic) acid, diethylenetriamine penta(methylene phosphonic) acid, and the water-soluble salts thereof. Amino tris(methylene phosphonic) acid or its water-soluble salts (as DEQUEST 2000®) is a preferred chelator. The pH range of the compositions helps provide stability to the hydrogen peroxide and is typically in the acid-slightly basic range from about 3 to about 8, preferably about 6.

Organic Solvent - The preferred cleaning 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 useful herein. The isomer structures are as follows: n— C4H9— O— CH₂CH₂CH₂— O— CH₂CH₂CH₂— OH

CH₃ I n— C₄H₉— O— CH₂CH₂CH₂— O— CH₂— C— OH

H

While the spot cleaning compositions herein function quite well with only the BPP, water and surfactant, they may also optionally contain other ingredients to further enhance their stability. Hydrotropes such as sodium toluene sulfonate and sodium cumene sulfonate, short-chain alcohols such as ethanol and isopropanol, and the like, can be present in the compositions. If used, such ingredients will typically comprise from about 0.05% to about 5%, by weight, of the stabilized compositions herein.

Surfactants - Nonionics such as the ethoxylated C I Q-CJO alcohols, e.g., NEODOL 23-6.5, can be used in the compositions. The alkyl sulfate surfactants which may be used herein as cleaners and to stabilize aqueous compositions are the Cg-Ci g primary ("AS"; preferred C10-C14, sodium salts), as well as branched-chain and random C10-C20 alkyl sulfates, and Ci ₀-Ci ₈ secondary (2,3) alkyl sulfates of the formula CH₃(CH₂)_x(CHOS0₃ ^"M⁺) CH₃ and CH₃ (CH )_y(CHOS0₃ ^"M⁺) CH₂CH₃ where x and (y + 1) are integers of at least about 7, preferably at least about 9, and M is a water-solubilizing cation, especially sodium, as well as unsatu rated sulfates such as oleyl sulfate. Alkyl ethoxy sulfate (AES) surfactants used herein are conventionally depicted as having the formula R(EO)_xS0₃Z, wherein R is Cιo^_Ci6 alkyl, EO is -CH2CH2-O-, x is 1-10 and can include mixtures which are conventionally reported as averages, e.g., (EO)2 5, (EO)₍5 5 and the like, and Z is a cation such as sodium ammonium or magnesium (MgAES). The C^-Cjg alkyl dimethyl amine oxide surfactants can also be used. A preferred mixture comprises MgAEι S/Ci 2 dimethyl amine oxide at a weight ratio of about 10:1. Other surfactants which improve phase stability and which optionally can be used herein include the polyhydroxy fatty acid amides, e.g., C12-C14 N-methyl glucamide. AS stabilized compositions preferably comprise 0.1%-0.5%, by weight, of the compositions herein. MgAES and amine oxides, if used, can comprise 0.01%-2%, by weight, of the compositions. The other surfactants can be used at similar levels.

Other Optionals - In addition to the water, the preferred BPP solvent, the optional H2O2 and the surfactants disclosed above, liquid compositions used herein may comprise various optional ingredients, such as perfumes, preservatives, brighteners, salts for viscosity control, pH adjusters or buffers, and the like. The following illustrates preferred ranges for cleaning compositions for use herein, but is not intended to be limiting thereof.

Ingredient % (wt.) Formula Range

BPP (Solvent) 0.05-5

Surfactant 0-2

Perfume 0.01-1.5

Water Balance pH range from about 6 to about 8. Other solvents or co-solvents which can optionally be used herein include various glycol ethers, including materials marketed under trademarks such as Carbitol, methyl Carbitol, butyl Carbitol, propyl Carbitol, and hexyl Cellosolve, and especially methoxy propoxy propanol (MPP), ethoxy propoxy propanol (EPP), propoxy propoxy propanol (PPP), and all isomers and mixtures, respectively, of MPP, EPP, and BPP, as well as butoxy propanol (BP), and the like, and mixtures thereof. If used, such solvents or co-solvents will typically comprise from about 0.5% to about 2.5%, by weight, of the aqueous compositions herein. Non-aqueous (less than 50% water) compositions which optionally can be used in the pre-spotting step, can comprise the same solvents.

Dispenser - In one mode, the dispenser used herein comprises a container for the liquid pre-spotting composition, said container having a dispensing means which comprises a spout, preferably in the form of a hollow tube, which is connected to said container and is in communication with the interior of the container. In-use, a portion of the liquid composition within the interior of said container flows from the container through said spout, out the distal tip of said spout, and onto the stain which is being treated. The user manipulates the composition by daubing, smearing, pressing, or the like, using the distal tip to work the composition into the stain. A circular, rubbing motion is typical. By this means, the composition can be focused on the stained area. As the stain is loosened by the combined use of the aforesaid mechanical manipulation and the pre-spotting composition, the stain residues and the pre-spotting composition are transferred away from the fabric and into the underlying stain receiver. The fabric is then preferably re- positioned so that a fresh area of stain receiver underlies other stained areas, and the process is repeated until the pre-spotting operation is completed. The fabrics can then be used, as desired, or otherwise laundered or dry-cleaned.

Stain Removal Device - In another mode, a preferred embodiment of the arcuate device shown in Figure 1, the length of the arcuate base member (403) with its convex, generally rectangular configuration is about 2 inches (5 cm); its width is about 1.25 inches (3.2 cm); and its thickness is about 5/16 inch (0.8 cm). The width of shaft (404) at its mid-point is about 1 inch (2.54 cm) and its thickness at its midpoint is about 0.75 inch (1.9 cm). The length of the shaft

(404) extending perpendicularly outward from the rear of the arcuate base to the base of bulb

(405) is about 1.25 inches (3.2 cm). The bulb (405) which serves as a hand (or palm) rest has a circumference at its widest point of about 5.75 inches (14.6 cm). The combination of shaft and bulb thus comprise the hand grip for the device. The overall height of the device measured from the center of the top of the bulb (405) to the center point of the front face of the convex base is about 3 inches (7.6 cm). The dimensions of the sponge layer (402) and protuberances (401) are as given above.

Wet Abrasion Scrub Test The abrasion resistance of polymeric foams can be measured by the Wet Abrasion Scrub Test. A Wet Abrasion Scrub Tester can be used to perform these tests, and one such Tester was used for the comparative tests reported in Example I, below. Specifically, the Tester used to generate the data reported in Tables IA and IB was manufactured by Sheen, Model REF 903PG. Other methods of testing abrasion resistance and machines for such tests will be known to those skilled in the art.

The Sheen Wet Abrasion Scrub Tester can hold up to four bottles which are capable of containing fluid, and which have a blunt, convex tip for dispensing the fluid. The bottles are inverted so that the blunt tip is pointing downward toward, and perpendicular (90°) to the base of the Tester. A sheet of polymeric foam is placed on the Tester's base followed by a fabric swatch, which is placed on top of the polymeric sheet, and the edges of both the polymeric sheet and the swatch are secured so that they remain stationary during the test. A silk swatch was used for the tests reported in Example I. A predetermined amount of fluid is then applied to the fabric swatch. While any amount of water or other common fluids can be selected, 3 gms of a cleaning composition similar to the one defined in Example II below is used for the tests reported in Example I. The bottle tips are then placed in contact with the fabric swatch.

The bottles can be weighted such that they apply a controlled amount of force to the sheet of polymeric foam. Any number of bottles and any appropriate weight can be used. For the comparative tests reported in Example I, three bottles are used for each test, one bottle has no load (Ogms), the second bottle carries a 200gm load and the third bottle has a 400gm load. The Tester then reciprocates the bottles back and forth along a straight line across the surface of the fabric swatch that is resting on the polymeric foam sheet. The tester can be reciprocated for any appropriate amount of time. At the end of the test the polymeric foam is visually compared to a sheet of reference polymeric foam which has undergone the same test.

The following Examples further illustrate the stain removal operation of the present invention, but are not intended to be limiting thereof.

EXAMPLE I

Tables IA and IB list the compositions of nine polymeric foams according to the present inventionn,, and one conventional polymeric foam that was used as the reference material. TABLE I TAA

TABLE LB

The Abrasion Resistance and Tearing tests are conducted versus the Reference polymeric foam. The ratings are based on visual comparisons of polymeric foam subjected to the Wet Abrasion Scrub Test that is defined above. Each polymeric foam, including the reference, is tested at Ogms, 200gms and 400gms. The results of the three tests for each polymeric foam are compared to the three tests for the reference polymeric foam.

Key to Abrasion Resistance Rating:

+++ = Substantially Better Abrasion Resistance

++ = Better Abrasion Resistance

+ = Slightly Better Abrasion Resistance

Key to Tearing Rating:

** = Little or no tearing occurred

* = Slight tearing but less tearing than the Reference.

- = More tearing than the Reference.

EXAMPLE II The spot cleaning operation herein for removing stain from a localized area on a fabric is conducted by: (a) underlaying the area containing said stain with the absorbent, polymeric foam stain receiver reinforced with non-woven spun-bonded polyester fabric, basis weight ca. 18 grams/meter^;

(b) applying a liquid cleaner (pre-spotter) composition to said stain from a container having a dispenser spout; and

(c) rubbing or pressing said cleaning composition into said stain using the distal tip of said spout, whereby said stain is transferred into the abrasion resistant polymeric stain receiver.

In this mode, the face of the distal tip of said spout can be concave, convex, flat, or the like. The combination of container plus spout is referred to herein conjointly as the "dispenser".

A typical dispenser herein has the following dimensions, which are not to be considered limiting thereof. The volume of the bottle used on the dispenser is typically 2 oz. - 4 oz. (fluid ounces; 59 mis to 118 mis). The larger size container bottle can be high density polyethylene. Low density polyethylene is preferably used for the smaller bottle since it is easier to squeeze. The overall length of the spout is about 0.747 inches (1.89 cm). The spout is of a generally conical shape, with a diameter at its proximal base (where it joins with the container bottle) of about 0.596 inches (1.51 cm) and at its distal of 0.182 inches (4.6 mm). The diameter of the channel within the spout through which the pre-spotting fluid flows is approximately 0.062 inches (1.57 mm). In this embodiment, the channel runs from the container bottle for a distance of about 0.474 inches (1.2 cm) and then expands slightly as it communicates with the concavity to form the exit orifice at the distal end of the spout.

Compositions for use herein with the aforesaid dispenser and the abrasion resistant polymerized foam stain receiver is as follows. INGREDIENT Nonionic Comp. Anionic Comp.

Hydrogen peroxide 1 1

Amino tris(methylene phosphonic acid)* 0.04 0.05

Butoxypropoxypropanol (BPP) 2 2

Neodol 23 6.5 0.3

NH Coconut Ei S — 0.3

Dodecyldimethylamine oxide — 0.03

Magnesium chloride — 0.02

Magnesium sulfate — 0.02

Hydrotrope, perfume, other minors, — 0.1

Kathon preservative 0.0003 0.0003

Water (deionized or distilled) 96.6 96.5 Target pH** 6.0 6.0

^♦Stabilizer for hydrogen peroxide

**Range pH 5-8

EXAMPLE III

Examples of preferred, high water content, low residue compositions for use herein are as follows. The compositions are listed as "nonionic" or "anionic", depending on the type of surfactant used therein.

Ingredient Nonionic (%) Anionic (%)

Butoxypropoxypropanol (BPP) 2.00 2.00

NEODOL 23 6.5 0.250 —

NH₄Coconut Eι S* — 0.285

Dodecyldimethylamine oxide — 0.031

MgCl₂ — 0.018

MgS0₄ — 0.019

Hydrotrope, perfume, other minors — 0.101

KATHON preservative 0.0003 0.0003

Water 97.750 97.547

^♦Ammonium salt of C12-C14 (coconut alkyl) ethoxy (EO-1) sulfate.

In a highly preferred mode, the liquid Nonionic or Anionic composition is applied to the stained area from a dispenser in the manner of Example I to remove stain from fabrics.

Claims

What is claimed is:

1. A polymeric foam which comprises a polymerized water-in-oil emulsion having:

1) an oil phase characterized by: a) from 85 to 98% by weight of a monomer component, said monomer component characterized by: i) from 25 to 70% by weight of a substantially water-insoluble, monofunctional monomer capable of forming a polymer having a Tg of 25 ┬░C or less; ii) from 25 to 65% by weight of a substantially water-insoluble, monofunctional comonomer capable of imparting toughness about equivalent to that provided by styrene; iii) from 5 to 25% by weight of a first substantially water-insoluble, polyfunctional crosslinking agent selected from the group consisting of divinylbenzenes, trivinylbenzenes, divinyltoluenes, divinylxylenes, divinylnaphthalenes divinylalkylbenzenes, divinylphenanthrenes, divinylbiphenyls, divinyldiphenylmethanes, divinylbenzyls, divinylphenylethers, divinyldiphenylsulfides, divinylfurans, divinylsulfide, divinylsulfone, and mixtures thereof; and iv) from 0 to 15% by weight of a second substantially water-insoluble, polyfunctional crosslinking agent selected from the group consisting of polyfunctional acrylates, methacrylates, acrylamides, methacrylamides, and mixtures thereof; v) wherein the weight ratio of the monofunctional comonomer capable of imparting toughness (ii) to the sum of the first and second polyfunctional crosslinking agents (iii + iv) is at least 1: 1; b) from 2 to 15% by weight of an emulsifier component which is soluble in the oil phase and which is suitable for forming a stable water-in-oil emulsion; and

2) a water phase characterized by from 0.2 to 20% by weight of a water-soluble electrolyte; and

3) a volume to weight ratio of water phase to oil phase of at least 16:1.

2. The polymeric foam material of claim 1 wherein the weight ratio of the monofunctional comonomer capable of imparting toughness (ii) to the sum of the first and second polyfunctional crosslinking agents (iii + iv) is at least 2: 1.

3. The polymeric foam material of claim 1 wherein the weight ratio of the monofunctional comonomer capable of imparting toughness (ii) to the sum of the first and second polyfunctional crosslinking agents (iii + iv) is at least 3:1.

4. The polymeric foam material of claim 1 wherein the weight ratio of the monofunctional comonomer capable of imparting toughness (ii) to the sum of the first and second polyfunctional crosslinking agents (iii + iv) is at least 5:1.

5. The polymeric foam of claim 1 wherein the oil phase of the emulsion comprises from 30 to 65% of the monofunctional comonomer capable of imparting toughness equivalent to that provided by styrene.

6. An abrasion resistant stain receiver characterized by the polymeric foam of claim 1.

7. An abrasion resistant stain receiver characterized by the polymeric foam of claim 2.

8. An abrasion resistant stain receiver characterized by a polymeric foam which comprises a polymerized water-in-oil emulsion having:

1) an oil phase characterized by: a) from 85 to 98% by weight of a monomer component, said monomer component characterized by: i) from 25 to 70% by weight of a substantially water-insoluble, monofunctional monomer capable of forming a polymer having a Tg of 25┬░C or less; ii) from 25 to 65% by weight of a substantially water-insoluble, monofunctional comonomer capable of imparting toughness about equivalent to that provided by styrene; iii) from 5 to 25% by weight of a first substantially water-insoluble, polyfunctional crosslinking agent selected from the group consisting of divinylbenzenes, trivinylbenzenes, divinyltoluenes, divinylxylenes, divinylnaphthalenes divinylalkylbenzenes, divinylphenanthrenes, divinylbiphenyls, divinyldiphenylmethanes, divinylbenzyls, divinylphenylethers, divinyldiphenylsulfides, divinylfurans, divinylsulfide, divinylsulfone, and mixtures thereof; and iv) from 0 to 15% by weight of a second substantially water-insoluble, polyfunctional crosslinking agent selected from the group consisting of polyfunctional acrylates, methacrylates, acrylamides, methacrylamides, and mixtures thereof; v) wherein the weight ratio of the monofunctional comonomer capable of imparting toughness (ii) to the sum of the first and second polyfunctional crosslinking agents (iii + iv) is at least 1:1; b) from 2 to 15% by weight of an emulsifier component which is soluble in the oil phase and which is suitable for forming a stable water-in-oil emulsion; and

3) a volume to weight ratio of water phase to oil phase of at least 16:1.

9. A process for cleaning stained areas on fabrics by:

(a) placing the stained area of the fabric over and in contact with the abrasion resistant stain receiver of claim 7 or 8;

(b) applying enough cleaning composition to saturate the localized stained area;

(c) optionally, allowing the composition to penetrate the stain for 3-5 minutes;

(d) optionally, applying additional composition;

(e) applying mechanical force to the stained area;

(f) removing the fabric from contact with the stain receiver article; and

(g) optionally, blotting the fabric between paper towels or other absorbent materials to remove excess cleaning composition.