US 3392046 A
Description (OCR text may contain errors)
United States Patent FIBROUS ORGANIC MATERIAL HAVING AFFIXED THERETO A POLYPERFLUORO ALKYL METH- ACRYLATE ESTER AND METHOD FOR MAK- ING SAME Herman Lowell Marder, Plainfield, N.J., assignor to Colgate-Palmolive Company, New York, N.Y., a corporation of Delaware No Drawing. Filed June 17, 1963, Ser. No. 288,442
12 Claims. (Cl. 117-143) ABSTRACT OF THE DISCLOSURE Fibrous Organic material are rendered water, oil, stain and soil repellent by treatment with emulsions or solutions of perfluoro alkyl methacrylate polymers containing a terminal CF group.
The present invention relates to the preparation of omega-fiuoroor terminal -CF polymers of methacrylic acid and to the treatment of fibrous materials such as paper, leather, textiles and the like with the aforesaid omega-fluoroor terminal -CF polymers.
The development of the principles of water repellency for obtaining textile materials which resist wetting by water cover the period of 1935 to 1940. Prior to that period, textile materials were coated with various compositions such as rubber, linseed oil-rubber mixtures, synthetic dopes, and other bizarre compositions which formed a continuous coating on the woven material and prevented water penetration.
Without understanding the basic principles of surface free energy, contact angle and spreading coeflicient, several unrelated practical developments evolved during the period from 1935 to 1940 which changed the art of textile waterproofing. In Germany, especially at Chemische Fabrike Pferze, a series of parafiin wax emulsions was developed which, when padded onto textiles, produced a high contact angle of water drops on the surface and a high degree of shower resistance without changing the porosity or air permeability of the textile material. These treated fabrics were non-wettable by water or water borne liquids and stains because of the change in free energy of the fiber surfaces and not because of closing or plugging the holes in the interstices of the fabric.
By the use of the new wax emulsion-metallic salt compositions, it was then possible to produce fabrics which had the feel and appearance of conventional textiles, but did not look like oil-cloths, or rubberized coated fabrics. The only practical limitation of such compositions was the durability to washing and dry cleaning. Such products comprise generally a composition containing:
(a) A paraffin wax or mixtures of vegetable wax esters such as carnauba, candililla, or sugar cane wax.
(b) An emulsifying agent, generally glue, gelatin, and
(c) An aluminum or zirconium salt, usually formates or acetates. The primary function of such salts is to insolubilize the glue and other emulsifiers after the emulsion is deposited on fabrics.
A large variety of such products are still in use as low cost non-durable water repellants for textiles. Since neither thermosetting nor reaction with the fiber occurs with such products, they all ane non-durable to washing and dry-cleaning. Other than water repellency for rain wear fabrics, such products produce fabrics which have a fair degree of spot and stain resistance to water-borne stains.
The search for durable or relatively permanent water "Ice repellents, especially for cellulosic fibers, evolved from the deficiencies of the wax emulsions. One of the first, if not the first, product to overcome the deficiencies of the wax emulsions was made available in Great Britain under the name of Velan. This was octadecyloxymethyl pyridinium chloride, a quaternary ammonium compound made by the chloromethylation of octodecanol followed by quaternization with pyridine. This compound is unstable and under acid conditions reacts with surfaces containing active hydrogen, e.-g., the hydroxyl group of cellulose fibers (ZOH) as indicated by the following formula:
Fabrics treated with such a compound are durably water repellent, are porous, soft, and appear like untreated fabrics. The stearamidomethyl analogue of Velan having a composition corresponding to the formula:
017E356 ONHCH IE G is known commercially as Zelan and Norane R. The advantage of the stearamide product is greater initial water repellency and greater durability to washing. Such products are still leaders in rain wear fabric finishes.
Other fiber reactive and durable water repellents have been developed and are represented by silicone water repellents, methylol stearamide compositions, hydrophobic resins, octadecyl ketene dimer and others.
While durable water repellents had been developed initially for outerwearand raincoat-type applications, in the period 1950 and 1956 such products began to be used widely on mens suitings, dress goods, and upholstery materials. It has been observed that fabrics treated with such durable water repellents have a high degree of soil resistance to water-borne soils and stains. However, a major limitation of such finishes is that they attract oily soils, and the fabrics are not stain repellent to oily materials such as oils, greases, gravy, mayonnaise, etc.
The fabrics treated with polymerized perfiuoroalkyl esters of acrylic acid, e.g., those described in US. Patent No. 2,642,416, possess some of the advantages of the hereinbefore discussed durable water repellents plus the capability of resistance to staining by oil-borne stains. However, these polyacrylic acid esters are deficient in practical use since they are prone to enhance the tenacious adherence of particulate soil on the surface of the fabric. As a result, it is not practical to use these materials on white fabrics. For example, a garment treated with such materials, and rendered thereby oil and water repellent and resistant to liquid stains to a degree, would nevertheless be soiled in use by contact with particulate soiling materials so as to appear dirty and esthetically unacceptable. Therefore, it is evident that there are mechanisms of soiling involved, other than contact with staining liquids, in the practical use of repellent materials and the presently known materials are inherently self-defeating in this respect.
In contrast to the aforedescribed deficiency of the polyperfluoroalkyl esters of acrylic acid, it has now been found that all of the advantages of these repellents are retained and, in addition, the deficiencies of the aforesaid poly-acrylic acid esters are overcome by the use of the novel polymeric materials herein described. Fi-
brous materials are made repellent to particulate soils and the residue of the aforesaid particulate soil remaining on the fibrous material after conventional laundering is markedly reduced, by aflixing to the fibrous material polymerized perfluoroalkyl esters of methacrylic acid.
The polyperfluoroalkyl esters of methacrylic acid have Table II is a comparison of 2 HM-8 and 3 HM-7 polymeric coatings on 80 x 80 cotton fabric obtained by padding the fabric with 1% solutions of each polymer in 1,3-bis(trifluoromethyl)benezene, followed by drying to remove the solvent. The coatings exhibit the following characteristics TABLE 11 Liquid Repellency Rating Staining Characteristics Polymer Water Spray Oil Water Borne Oil Borne Repel- Launder- Repel- Launderlency ability lency ability (a) 2 HM-8 100 100/90 6. 4 8. 8 8. 9. 0
(b) 3 HM-7 50/0 0+ 5. 4 8. 4 4. 8 6. 8
(c) Untreated Cotton 0 1.8 5.4 1.8 5.6
compositions corresponding to the following repeating unit:
C Ha -CHz- O=C OCH2(C F2) CF;
where F is fluorine and x is 1 to 20, preferably 2 to 12.
The monomer should be polymerized sufliciently so that it is not soft and tacky and should be substantially free from unconverted monomer and other low molecular weight telomers. The inherent viscosity which is a measure of the degree of polymerization will vary depending upon the particular fluorinated ester but will be usually within the range of about 0.2 to 3, and preferably at least about 0.5, said inherent viscosity being determined by the method described in Sorenson and Campbell, Preparative Methods of Polymer Chemistry, Interscience Publishers, N.Y., 1961. The invention in its broadest aspect is not limited to this range since lower and higher polymers are useful also. In general it is considered that the number of repeating units (n) will be at least about 10 which can be illustrated by enclosing the above formula in brackets followed by the subscript n.
The capabilities of these novel perfiuoroalkyl esters of methacrylic acid having a terminal CF group are to be distinguished from the capabilities of either (1) methacrylic acid esters having a terminal CHF group or (2) acrylic acid esters having a terminal CF group. The novel methacrylic acid esters having a terminal CF group of the present invention endow the treated substrate or fabric with a more universal resistance to soiling than is given to fabrics or substrates by either acrylic acid esters having a terminal CF group or the methacrylic acid esters having a terminal -CHF group. This is established by the data presented in the following tables using the test procedures described hereinafter involving comparisons of the properties of the polymers of the following three materials:
TABLE I Liquid Repellency Rating Polymer Water Spray Oil (a) 3 HM-7 70 01- (b) 2 HM-8 70/0 50 (c) Untreated Cotton 0 0 It is apparent from the above data in Tables I and II that the 2 HM-8 polymer of the present invention confers markedly superior liquid repellency to water and especially oil as compared to the 3 HM-7 polymer under the same conditions as illustrated by the higher ratings in the liquid repellancy tests.
Similarly, it is apparent from Table II that the 2 HM-8 polymer exhibits particularly unusual and effective antistaining characteristics in comparison to the effects produced by the 3 HM7 polymer (the higher the rating number approaching 10 means the greater the resistance to staining, and the higher the launderability number meaning the better removal of the stain).
Another unique property of the polymers of the present invention such as the 2 HM-S is their resistance to particulate soil. As indicated, fabric treated with the corresponding poly-acrylate esters exhibit elfective liquid repellency properties also, but these materials are particularly deficient in resistance to dry soil. The marked superiority of the methacrylate polymers of the present invention in comparison to the acrylate types is illustrated in Table III wherein the 2 HM-S polymer is compared to the previously-described 2 I-IA-8 and to a commercial product having a polymer of a modified fluoroacrylate ester known as FC-208. For these tests, the cotton fabric is padded as described with a 2% concentration of the polymers and dried. The treated materials are subjected to staining by particulate oily dirt and the reflectance of the fabric is measured before and after washing, in comparison to an untreated control. In the table, a higher value indicates greater whiteness and therefore less staining of the fabric by the particulate soil.
The unusual properties of the fabric treated with the 2 HM-8 polymer of the present invention is self-evident from the data. The 2 HM-8 polymer-treated fabric, before laundering, exhibited much greater resistance to dry soil as compared to the untreated cotton as a control. In contrast, the fabrics treated with the 2HA-8 and FC-208 materials exhibited no significant improvement in resistance to the particulate soil since their reflectance value before laundering were approximately the same as the untreated fabric.
The comparative reflectance values after laundering are particularly significant also. After washing, the fabric treated with the 2 HM-8 polymer was found to be as clean as the untreated cotton. In contrast, the fabrics treated with the acrylate polymers were found to be far dirtier than the untreated cotton indicating incomplete removal of the adsorbed soil to a substantial degree. Thus, these polymeric materials appear to promote retention of particulate soil in addition to offering no resistance to its pickup on the fabric. A moments reflection recognizes that the major mechanism of soiling is the dynamic contact of a clean surface, such as the neckband or the cufi of the sleeve of a mans shirt with a surface having thereon particulate soil such as the dust and dirt held on the neckband or cuff by the oily exudations of the human skin. Thus, a mans shirt treated with the other polymers indicated above will appear tattle-tale grey after washing, whereas a shirt treated with the 2 HM-8 polymer of the present invention will appear clean, white, and not tattle-tale grey.
The data presented above clearly establish that although the difference in chemical structure between the novel perfluoroalkyl esters of the present invention in one comparison appears to be only the difference between an ester of acrylic acid and an ester of methacrylic acid and in the other instance the difference is between a terminal -CHF group and a terminal CF group, nevertheless these differences appear to make the critical factor essential to superior universal or overall resistance to soiling, and particularly the difference between washed fabrics which are grey and washed fabrics having the white, clean appearance of untreated fabric.
The novel monomeric esters of the present invention are prepared by the classical methods of organic chemistry such as the esterification of methacrylic acid with the alpha, alphadihydroperfluoroalkanol [CF (CH CH OH] with distillation of the water produced or by reaction of methacrylyl chloride with the perfluoroalkanol in the presence of an acid acceptor or by the reaction of methacrylic anhydride with the perfluoroalkanol.
Thus, for example, 1,1-dihydropentadecafluorooctylmethacrylate was prepared from the following charge in the manner described hereinafter.
300 cubic centimeters flask equipped with a stirrer, a Dean-Stark azeotrope apparatus, a condenser on the top of the Dean-Stark apparatus, with a thermometer.
PROCEDURE (1) Charged reactants; heated eight minutes before condensed water and benzene refluxed and accumulated in the trap. (In the following log consider the foregoing enumerated eight minutes as zero time).
Cubic centimeters Time (minutes) Water distilled 1 Theoretically only 1.8 cubic centimeters should have been produced in the complete esterlfication of the perfluoroalka- I101. The excess water arises from the water in the reactants.
(2) Attached simple distilling head, thermometer and condenser, nitrogen capillary (no stirring) and water suction to the reaction flask. The reaction mixture was dis tilled at reduced pressure to obtain the following fractions:
Pressure, Temper- Weight, Fraction No. mm. of Hg atpz, gm.
I 83-20 43-85 40. 7 II 20 72-102 8. 3
(Water acidentally was introduced.) Fractions I and II were combined washed with water and redistilled with 0.05 grams of hydroquinone.
Weight of Fractions I and II-34-6 grams Fraction 2-2 was practically percent of the monomer, dihydropentadecafluorooctyl ester of methacrylic acid. Fraction 21 was a mixture of the alcohol and the aforesaid monomer.
Similar methacrylate monomers are prepared in like manner from other fluorinated alcohols having a similar structure such as the corresponding 1,1 dihydro butyl, nonyl, decyl and dodecyl alcohols and the like (all other hydrogens being replaced by fluorine).
The monomeric methacrylic acid esters of perflu-oroalkanols having a terminal -CF group are polymerizable by known emulsion polymerization techniques employing anionic, non-ionic, and cationic surfactants. The method of polymerization may be by emulsion, solution or bulk, with ionic or radical catalysts. A preferred emulsion technique is exemplified by the following example:
CHARGE Grams Deionized water 28.00 Sodium lauryl sulfate 0.50 Sodium tetraborate 0.07 1,1-dihydropentadecafluorooctylmethacrylate 14.00 Potassium persulfate .08
PROCEDURE (1) Charged flask with all materials except the persulfate catalyst. Swept nitrogen through without agitation for 15 minutes. Heated contents of flask with stirring to 48.5 C. in 16 minutes.
(2) Added 0.04 gram of persulfate. In 40 minutes a trace of trubidity indicated initiation of the polymerization. Heated the contents of the flask for 68 minutes more and added 0.02 gram of persulfate.
(3) Heated contents of the flask 16 minutes more and added 0.02 gram persulfate. Heated contents of flask for three and a half hours more, and then cooled the flask and contents. Maximum temperature 50-55 C., total time11.6 hours.
(4) Poured 35.4 grams of reaction emulsion into jar. The emulsion was calculated to contain 26.7 percent solids when dried to a hard polymer.
The polymer emulsion is usually dried at elevated temperature to remove the unconverted monomer. The 2 HM-8 polymer obtained is a hard, tough material which is non-rubbery and non-tacky at room temperature. This solid melts to form a clear viscous liquid when heated to about 550 F. Upon analysis, it corresponds to the structure:
-[CH t The polymeric materials may be applied in any suitable manner. For example, the substrate, e.g. cotton, was
contacted with the finishes in a laboratory textile paddler in a conventional one dipone nip to a wet pick-up of the desired concentration of finish. Thus, for a deposition of one percent of solids from a one percent concentration of solids in solvent or aqueous emulsion at a 90 percent wet pick-up the concentration of polymer in the aqueous emulsion or in the solvent is increased from one percent for 100 percent wet pick-up to 1/0.9 or 1.1 percent. Thus, for example, a known weight of 80 x 80 cotton print cloth (Style #400-test fabrics) was immersed in a known quantity of water and an aqueous emulsion of the polymer slowly added to provide the test concentration of polymer in the bath for an 80 to 90 percent wet pick-up. The bath was agitated for 10 minutes, the test cotton removed from the bath, and passed through the rollers once (one nip). The test cotton was then dried and cured at a temperature in the range of room temperature to about 375 F.
Alternatively, these polymerized perfluoroalkyl esters of methacrylic acid having a terminal CF group also can be applied to the substrate from a solution in a solvent for the esters such as tritiuoromethyl benzene, i.e., trifiuorotoluene, hexafluoroxylene, aliphatic fluoroesters such as methylperfiuoroacetate and similar perfiuoro organic solvents. Presently, it is preferred to use trifluorotoluene as the solvent. For example, pentadecafiuorooctyl me-thacrylate as a 1 percent solution in his (trifluoromethyl) benzene was applied to cotton cured 10 minutes at 300 F. and subjected to the tests described herein after was found to exhibit excellent water-repellency, oil-repellency and dry stain repellency.
In general, the polymer is deposited from a liquid medium such as the aqueous emulsion so that the treated fibrous material has an elemental fluorine analysis in the range of 0.05 to 5%. The polymer is usually deposited on the fabric in an amount of 0.1 to by weight of the fabric. The fabric treated with the polymeric materials may be dried in any suitable manner, including air-drying, i.e., room temperature of about 70- 75 F., to about 375 F. It is preferred to air-dry followed by curing, though the curing may be of the wet fabric directly, at an elevated temperature in known manner such as up to about 375 F. for about 5 to 60 minutes, preferably about 200 to 375 F.
For rating the efiicacy of a finish to provide (1) waterrepellency, (2) oil-repellency, (3) dry-stain repellency, and (4) resistance to staining by water-borne stains and oil-borne stains, four procedures or tests are used.
Water repellency This test is a modification of the spray test designated AATCC Standard Test Method 22-1952 to emphasize ratings when hydrophobic properties of the finish confine the area of Wetting but permit wetting through. Thus, a spray rating number 70/0 indicates a 70 spray rating pattern. The 0 in the denominator indicates wetting to the under surface of the cloth at the wet areas but does not differentiate between small or large areas of wetting through.
The AATCC Standard Test Method 22-1952 is applicable to any textile fabric. It measures the resistance of fabrics to wetting by a water spray and the results depend primarily on the degree of hydrophobicity inherent in the fibers and yarns and the subsequent treatments applied. Water is sprayed against the taut surface of a test specimen. Evaluation of the wetted pattern is readily brought about by comparing the wetted pattern with standard wetting pattern pictures:
100No sticking or wetting of upper surface 90Slight random sticking or wetting of upper surface 80Wetting of upper surface at spray points 70--Partial wetting of whole of upper surfaces 50Complete wetting of Whole of upper surfaces 0Complete wetting of whole of upper and lower surfaces.
The test specimens of a minimum size of 7" x 7" are conditioned at 70. F. and 65 percent relative humidity for a minimum of four hours before testing.
The test specimen, fastened securely and wrinkle-free in a metal hoop having a diameter of 6 inches is placed and centered 6 inches under a standard spray nozzle at an angle of 45 degrees to the horizontal. Two hundred and fifty milliliters of water at i2 F. is poured into the funnel attached above the spray nozzle. The spray lasts 25 to 30 seconds at the end of which time the hoop is taken by one edge and the opposite edge tapped smartly once against a solid object with the wet side facing the solid; this procedure is repeated with the hoop reversed 180 degrees.
Oil repellency This test is a modification of the test described in the publication of the Minnesota Mining and Manufacturing Company 3M Textile Chemicals Appendix A, Test Methods, page 1.
The modification is concerned with a refinement of the rating system. The oil repellency rating in the numerator refers to the normal 3M rating system. The number in the denominator refers to the highest rated drop not wet through as observed when turning the specimen over at the end of the specified period of three minutes. To determine fine points in ratings below 50/0, the following symbols were designated:
Period with no wetting Symbol or penetration 0+ 2 to 30 seconds 0+2 30 to seconds 0+3 1 90 seconds to just below 3 minutes.
Percent n-Heptane Oil Repelleney Rating Percent Nujol (by volume) (by volume) 1 No hold out to Nujol.
The standard oil-heptane mixture are contained in small stoppered medicine dropper bottles. A drop of each mixture is placed on the fabric to be tested. The appearance of the test oil is observed through the drop. Note whether wetting or penetration occurs. The number corresponding to that mixture containing the highest percentage of n-heptane which does not penetrate or wet the fabric after three minutes is considered the oil repellency rating of the system.
The change in the optical refractivity of the drop is often an indication of wetting. In some cases wetting can be determined better by observing the other side of the fabric. In some cases of 0 oil/heptane rating, the symbol 0+ has been used to indicate some resistance to wetting by oil.
Stain repellency (liquid stains) The fabrics to be tested are stretched lightly on 12" x 31 frames. All or part of the frame area is used depending upon the amount of the test fabric available. The frames are supported at both ends with the fabric about 8 inches above a black horizontal surface. The fabric touches nothing except the frame.
Three inch medicine droppers are used to draw the liquid stains from their containers. Each stopper is callbrated and marked on the exterior for a volume of one cubic centimeter. The liquid stain is squeezed vertically downward from a height of 2 inches above the cloth.
After five minutes the unabsorbed stain is wiped off the fabric with two sweeps of Kleenex tissue and the stains rated as follows:
Duplicate sets of stains are applied in separate areas so that one-half of the fabric can be Washed. Generally, the wash is carried out with 50 grams of Fab, a cotton cycle, and a dummy lead to total 5 pounds in a Norge Home Automatic Washer.
WATER STAINS Instant tea Blue-black ink Grape juice Salad mustard Chocolate syrup OIL STAINS Salad oil 20/20 motor oil Oleomargarine Tomato sauce 10. Hand Lotion 8 cc. dry powder/200 cc. water applied 160 F. 2 Melted and applied at 160F.
In all cases the stains are allowed to dry on the fabrics for twenty-four hours before washing.
Dry soil test Fifteen to twenty 6" x 8" numbered specimens, usually 80 X 80 cotton, including at least one untreated control are tumbled for thirty minutes with 10 percent, based on the weight of the fabric of Cyanamid Soil. The tumbling is carried out in a 5 liter capacity Five Minute Home Cleaner at 44 r.p.m. Six No. 8 neoprene rubber stoppers are distributed among the specimens to increase mechanical action. At the end of the tumbling, the specimens are removed and each shaken up and down fifteen times by hand to remove surface dirt.
The specimens are then cut to produce two pieces each 4" x 3". One half, i.e., one piece is washed with 50 grams of Fab in a cotton cycle with a five pound dummy load, then hung to dry and lightly ironed under a clean cotton cloth.
The degree of soil is determined with the Photovolt Reflectance Meter (Tri Blue filter). Six readings per specimen are made and the arithmetic average reported.
The Cyanamid Soil is prepared by blending the dry ingredients thoroughly. The blended dry ingredients are dried in a forced draft convection oven for eight hours at 50 C., then milled twenty-five hours with ceramic balls and stored in a polyethylene bag.
Dry soil ingredients 1 R. '1. Vanderbilt Peer1ess" grade or equivalent.
2 Davison Chemical Company.
3 Benny and Smith Company, Molaceo.
4 C. K. Williams Company.
In addition to the improved overall or total repellency exhibited by fabric treated with said polymers, the polymers are generally more heat, light and chemically stable than various fiuoro chemical sizing agents known in the art.
Although the present invention has been described with reference to particular embodiments and examples, it will be apparent to those skilled in the art that variations and modifications of this invention can be made and that equivalents can be substituted therefor without departing from the principles and true spirit of the invention.
What is claimed is:
1. Fibrous organic material having afiixed thereto in an amount suificient to render said material resistant to water, oil, water-borne stains, oil-borne stains and dry soils, a polymer of a perfiuoroalkylmethacrylate ester having the formula where F is a fluorine and x is 1 to 20.
2. Cotton having afiixed thereto a polymer in an amount sufficient to render the cotton repellent to particulate soil and reducing the residue of said particulate soil remoining after cotton and afiixed polymer have been laundered in a conventional manner, and making said cotton and afiixed polymer resistant to water, oil, waterborne stains, oil-borne stains and dry soils, said polymerrepellent comprising perfiuoroalkylmethacrylate ester, said perfluoroalkylmethacrylate ester having the formula where F is fluorine and x is 1 to 20.
3. Cotton in accordance with claim 2 wherein said polymer has an inherent viscosity in the range of about 0.2 to 3 and x is 2 to 12.
4. Cotton as defined in claim 2 wherein the perfluoro ester is pentadecafluorooctylmethacrylate.
5. A method of making fibrous organic material repellent to particulate soil and to reduce the residue of said particulate soil remaining on said fibrous material after laundering whilst making said fibrous material resistant to water, oil, water-borne stains, oil-borne stains and dry soils which comprises depositing a polymer of perfluoromethacrylate ester on said fibrous material, said ester having the formula:
CH3 HzC=CI7 O=CO--CH2(CF2);CF3
where F is fluorine and X is 1 to 20, maintaining said treated fibrous material at a temperature in the range of room temperature to about 375 F. and obtaining treated fibrous material having a fluorine content in the range of 0.05 to 5 percent.
1 l 6. The method set forth in claim 5 wherein the treated fibrous material'is air-dried and then cured at an elevated temperature up to about 375 F. for about five to sixty minutes.
7. A method as defined in claim 5 is deposited by padding.
8. A method as defined in claim 5 wherein the polymer is deposited from a perfiuoro organic solvent.
9. A method as defined in claim 5 wherein the polymer is deposited from an aqueous emulsion.
10. A method of making fibrous organic material sub strate resistant to soiling by particulate soil and to reduce the residue of said particulate soil remaining on said fibrous material after laundering whilst making said fibrous material resistant to water, oil, water-borne stains, oil-borne stains and dry soils which comprises contacting said substrate, with an aqueous emulsion of polymeric perfluoroalkylmethacrylate ester, said ester having the formula:
wherein the polymer where F is fluorine and X is 1 to 20 in amount to provide at least about 0.1 to about percent by weight of said poly-perfluoroalkylmethacrylate based upon the weight of said substrate, separating the so-treated substrate from said aqueous emulsion and drying said treated substrate at a temperature in the range of room temperature to about 375 F.
11. A method of making fibrous organic material re- 12 sistant to soiling by particulate soil and to reduce the residue of said particulate soil remaining on said fibrous ma terial after laundering whilst making said fibrous material resistant to water, oil, water-borne stains, oil-borne stains and dry soils which comprises contacting fibrous material hereinafter designated substrate, with a solution of a polymeric perfiuoroalkylmethacrylate ester in per fiuoro-organic solvent, said ester having the formula;
CH3 H C=( l 0=o0-0Hz(cFz),oF3
where F is fluorine and x is 1 to 20, separating the sotreated substrate from said perfluoro organic solvent, and curing said separated substrate at a curing temperature above room temperature and not in excess of about 375 F. to remove substantially all of said perfluoro-organic solvent.
12. The method set forth in claim 11 wherein the perfluoro-organic solvent is bis-trifluoromethyl benzene.
References Cited UNITED STATES PATENTS 2,642,416 6/1953 Ahlbrecht et a1. 26083.5 3,102,103 8/1963 Ahlbrecht et a1. 26029.6 3,282,905 11/1966 Fasick et al 26089.5
WILLIAM D. MARTIN, Primary Examiner.
T. G. DAVIS, Assistant Examiner.