| PATENT ASSIGNEE'S COUNTRY | USA |
| UPDATE | 09.00 |
| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | 19.09.00 |
| PATENT TITLE |
Waterborne fluoropolymer solutions for treating hard surfaces |
| PATENT ABSTRACT |
A method for imparting water, oil or stain repellency to HARD SURFACES comprising application to the surface of an effective amount of a composition comprising monomers copolymerized in the following percentages by weight: (a) from about 40% to about 90% of at least one monomer of formula I: R.sub.f --Q--A--C(O)--C(R).dbd.CH.sub.2 I wherein R.sub.f is a straight or branched-chain perfluoroalkyl group of 2 to about 20 carbon atoms, R is H or CH.sub.3, A is O, S, or NR.sub.1 wherein R.sub.1 is H or a C.sub.1 -C.sub.4 alkyl, and Q is alkylene of 1 to about 15 carbon atoms, hydroxyalkylene of 3 to about 15 carbon atoms, --(C.sub.n H.sub.2n) (OC.sub.q H.sub.2q).sub.m --, --SO.sub.2 --NR.sub.1 (C.sub.n H.sub.2n)-- or --CONR.sub.1 (C.sub.n H.sub.2n)-- wherein R.sub.1 is H or C.sub.1 -C.sub.4 alkyl, n is 1 to about 15, q is 2 to about 4, and m is 1 to about 15; (b) from about 2% to about 50% of a monomer of formula IIA or IIB or a mixture thereof: (CH.sub.2 .dbd.C(R)COZ(CH.sub.2).sub.r.sup.+ NR.sub.2 R.sub.3 R.sub.4)X.sup.- IIA and CH.sub.2 .dbd.C(R)COZ(CH.sub.2).sub.r NR.sub.2 R.sub.3 (O) IIB wherein R is H or CH.sub.3, R.sub.2 and R.sub.3 are each independently C.sub.1 -C.sub.4 alkyl, hydroxyethyl, or benzyl or R.sub.2 and R.sub.3 together with the nitrogen atom form a morpholine, pyrrolidine, or piperidine ring, R.sub.4 is H or C.sub.1 -C.sub.4 alkyl or R.sub.2, R.sub.3, and R.sub.4 together with the nitrogen form a piperidine ring, Z is --O-- or --NR.sub.4 -- r is 2 to 4, and X.sup.- is an anion, provided that the nitrogen is from about 40% to 100% salinized, quaternized, or present as amine oxide. |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | 11.02.99 |
| PATENT REFERENCES CITED | This data is not available for free |
| PATENT PARENT CASE TEXT | This data is not available for free |
| PATENT CLAIMS |
What is claimed: 1. A hard surface of rigid construction or building material which has been treated by a method for imparting water, oil or stain repellency, said method comprising application without heating to the surface of an effective amount of a composition consisting of monomers copolymerized in the following percentages by weight: (a) from about 40% to about 90% of at least one monomer of formula I: R.sub.f --Q--A--C(O)--C(R).dbd.CH.sub.2 I wherein R.sub.f is a straight or branched-chain perfluoroalkyl group of 2 to about 20 carbon atoms, R is H or CH.sub.3, A is O, S, or NR.sub.1 wherein R.sub.1 is H or a C.sub.1 -C.sub.4 alkyl, and Q is alkylene of 1 to about 15 carbon atoms, hydroxyalkylene of 3 to about 15 carbon atoms, --(C.sub.n H.sub.2n)(OC.sub.q H.sub.2q).sub.m --, --SO.sub.2 NR.sub.1 (C.sub.n H.sub.2n)-- or --CONR.sub.1 (C.sub.n H.sub.2n)-- wherein R.sub.1 is H or C.sub.1 -C.sub.4 alkyl, n is 1 to about 15, q is 2 to about 4, and m is 1 to about 15; (b) from about 2% to about 50% of a monomer of formula IIA or IIB or a mixture thereof: (CH.sub.2 .dbd.C(R)COZ(CH.sub.2).sub.r.sup.+ NR.sub.2 R.sub.3 R.sub.4)X.sup.- IIA and CH.sub.2 --C(R)COZ(CH.sub.2).sub.r NR.sub.2 R.sub.3 (O) IIB wherein R is H or CH.sub.3, R.sub.2 and R.sub.3 are each independently C.sub.1 -C.sub.4 alkyl, hydroxyethyl, or benzyl or R.sub.2 and R.sub.3 together with the nitrogen atom form a morpholine, pyrrolidine, or piperidine ring, R.sub.4 is H or C.sub.1 -C.sub.4 alkyl or R.sub.2, R.sub.3, and R.sub.4 together with the nitrogen form a piperidine ring, Z is --O-- or --NR.sub.4 -- r is 2 to 4, and X.sup.- is an anion, provided that the nitrogen is from about 40% to 100% salinized, quaternized, or present as amine oxide. 2. The surface of claim 1 wherein the material is selected from the group consisting of brick, stone, wood, concrete, ceramics, tile, glass, stucco, gypsum drywall, particle board, chip board, granite, marble, flagstone, and sandstone. 3. The surface of claim 1 wherein an amount of the composition applied to the surface is such to deposit from about 0.01 g fluorine per meter squared to about 4 g fluorine per meter squared. 4. The surface of claim 1 wherein for the monomer of formula I, Rf is a straight chain perfluoroalkyl group of 2 to about 20 carbon atoms, A is O, and Q is alkylene of 1 to about 15 carbon atoms. 5. The surface of claim 4 wherein the monomer of formula I is CF.sub.3 CF.sub.2 (CF.sub.2).sub.x C.sub.2 H.sub.4 OC(O)--C(H).dbd.CH.sub.2 or CF.sub.3 CF.sub.2 (CF.sub.2)x C.sub.2 H.sub.4 OC(O)--C(CH.sub.3).dbd.CH.sub.2 wherein x is an even integer from 2 to 18, or mixtures thereof. 6. The surface of claim 1 wherein formula I is perfluoroalkylethyl (meth)acrylate and formula IIA or IIB is diethylaminoethyl (meth)acrylate. -------------------------------------------------------------------------------- |
| PATENT DESCRIPTION |
FIELD OF THE INVENTION This invention relates to a method for treating hard surfaces including construction materials with a waterborne fluorochemical copolymer composition to impart water, oil and stain repellency. BACKGROUND OF THE INVENTION Hard surface materials used primarily for building or construction purposes such as brick, stone, wood, concrete, ceramics, tile, glass, stucco, plaster, gypsum drywall, particle board or chip board, are generally rigid or semi-rigid materials that are frequently exposed to weathering or to water-based cleaners which tend to penetrate and ultimately degrade the materials. They may also be exposed to solvents or oils.which tend to stain or otherwise affect their appearance or useful life. Treating agents for such materials should confer both oil and water repellency to the substrate in a single treatment, and should have a suitably long life with outdoor exposure. The use of fluorochemical copolymers for imparting oil and water repellency to textiles and paper products is known. For example, U.S. Pat. No. 4,147,851 of Raynolds issued Apr. 3, 1979, discloses that copolymers comprising 50% to 85% by weight of a perfluoroaliphatic acrylate/methacrylate monomer and 15% to 50% by weight of dialkylaminoalkyl acrylate/methacrylahte monomer or the corresponding amine salt, quaternary or amine oxide monomer are useful in oil and water repellency applications on textiles, leather and paper products. This patent does not teach that such copolymers have desirable properties when applied as a waterborne composition to hard surfaces with outdoor exposure. However, the use of certain other fluorochemical copolymers for imparting water, oil and stain repellency to hard surfaces is.known. Such copolymers include a fluorinated polyester/isocyanate/ catalyst composition in a diluting solvent. Use of perfluoropolyethers is known for protection against atmospheric pollutants. An acrylate/fluoroacrylate/ silicone or polyethylene wax/water-soluble stabilizer/water-insoluble coalescent agent/water composition is known for use in an anti-soiling treatment of construction materials. U.S Pat. No. 4,931,505 issued in 1990 discloses a coating composition comprising (A) a fluorine-containing copolymer with a fluorine content based on fluoroolefin of at least 10% by weight, and (B) a fluorine-containing copolymer of a polyfluorocarbon monomer with a hydrophilic group-containing monomer wherein said hydrophilic group is a member of a group containing, among others, a quaternary ammonium salt and an amine salt. It is said to provide a weather and stain resistant coating layer on surfaces such as metal, glass, and the like, but the coating solutions contain relatively high percentages of flammable volatile solvents, and these coatings can change the appearance of the coated surface by adding an adhering film. Thus, known compositions for treating hard surfaces can contain volatile-solvents which tend to pollute the atmosphere and are increasingly subject to adverse regulations, are flammable, add a coating layer to the substrate which affects its appearance or produce films which can blister or peel away from the substrate. There is a need for a treatment composition which imparts durable water, oil and stain repellency to hard surfaces with a minimum release of volatile organiic solvents. Preferably the treating compositions are soluble or self-dispersible in water for ease of application and cleanup, form coatings which do not change the appearance of the hard surface, and are not:subject to blistering or peeling. The present invention provides such a composition. SUMMARY OF THE INVENTION The present invention comprises a method for imparting water, oil or stain repellency to hard surfaces comprising application to the surface of an effective amount of a composition comprising monomers copolymerized in the following percentages by weight: (a) from about 40 to about 90% of at least one monomer of formula I: R.sub.f --Q--A--C(O)--C(R).dbd.CH.sub.2 I wherein: R.sub.f is a straight or branched-chain perfluoroalkyl group of 2 to about 20 carbon atoms, R is H or CH.sub.3, A is O, S or NR.sub.1 wherein R.sub.1 is H or C.sub.1 -C.sub.4 alkyl, and Q is alkylene of 1 to about 15 carbon atoms, hydroxyalkylene of 3 to about 15 carbon atoms, --(C.sub.n H.sub.2n) (OC.sub.q H.sub.2q)m--, --SO.sub.2 --NR.sub.1 (C.sub.n H.sub.2n)--, or --CONR.sub.1 (C.sub.n H.sub.2n)--, wherein R.sub.1 is H or C.sub.1 -C.sub.4 alkyl, n is 1 to about 15, q is 2 to about 4, and m is 1 to about 15; and (b) from about 2% to about 50% of a monomer of formula IIA or IIB or a mixture thereof: (CH.sub.2 .dbd.C(R)COZ(CH.sub.2).sub.r.sup.+ NR.sub.2 R.sub.3 R.sub.4)X.sup.- IIA and CH.sub.2 .dbd.C(R)COZ(CH.sub.2).sub.r NR.sub.2 R.sub.3 (O) IIB wherein R is H or CH.sub.3, R.sub.2 and R.sub.3 are each independently C.sub.1 -C.sub.4 alkyl, hydroxyethyl, or benzyl or R.sub.2 and R.sub.3 together with the nitrogen atom form a morpholine, pyrrolidine, or piperidine ring, R.sub.4 is H or C.sub.1 -C.sub.4 alkyl or R.sub.2, R.sub.3, and R.sub.4 together with the nitrogen form a piperidine ring, Z is --O-- or --NR.sub.4 -- r is 2 to 4, and X.sup.- is an anion, provided that the nitrogen is from about 40% to 100% salinized, quaternized, or present as amine oxide. The present invention further comprises the above method wherein the composition further comprises from about 0% to about 25% of a monomer selected from the group consisting of glycidyl (meth)acrylaLe, blocked isocyanatoalkyl(meth)acrylate, acrylamide, vinylidene chloride, (meth)acrylic acid, sulfatoalkyl(meth)acrylate, polyoxyehttlylelie (met-h)acrylate, styrene and vinyl toluene. The present invention further comprises a hard surface treated in accordance with the method of this invention. DETAILED DESCRIPTION OF THE INVENTION Superior water, oil and stain repellency can be imparted to hard surfaces including construction materials such as brick, stone, wood, concrete, ceramics, tile, glass, stucco, gypsum drywall, particle board, or chip board by the application of certain waterborne fluorochemical copolymer compositions. These can be applied to the surface by any convenient means such as painting with a brush, wiping with a sponge or cloth, spraying,.and other means. The highly efficient copolymers useful for this process or method of treatment are characterized in that they contain monomers copolymerized in the following percentages by weight, relative to the total weight of the copolymers: (a) from about 40% to about 90% of at least one monomer of formula I: R.sub.f --Q--A--C(O)--C(R).dbd.CH.sub.2 I wherein: R.sub.f is a straight or branched-chain perfluoroalkyl group of 2 to about 20 carbon atoms, R is H or CH.sub.3, A is O, S or NR.sub.1 wherein R.sub.1 is H or C.sub.1 -C.sub.4 alkyl, and Q is alkylene of 1 to about 15 carbon atoms, hydroxyalkylene of 3 to about 15 carbon atoms, --(C.sub.n H.sub.2n)(OC.sub.q H.sub.2q).sub.m --, --SO.sub.2 --NR.sub.1 (C.sub.2 H.sub.2n)--, or --CONR.sub.1 (C.sub.n H.sub.2n)--, wherein R.sub.1 is H or C.sub.1 -C.sub.4 alkyl, n is 1 to about 15, q is 2 to about 4, and m is 1 to about 15; and (b) from about 2% to about 50% of a monomer of formula IIA or IIB or a mixture thereof: (CH.sub.2 .dbd.C(R)COZ(CH.sub.2).sub.r.sup.+ NR.sub.2 R.sub.3 R.sub.4)X.sup.- IIA and CH.sub.2 .dbd.C(R)COZ(CH.sub.2).sub.r NR.sub.2 R.sub.3 (O) IIB wherein R is H or CH.sub.3, R.sub.2 and R.sub.3 are each independently C.sub.1 -C.sub.4 alkyl, hydroxyethyl, or benzyl or R.sub.2 and R.sub.3 together with the nitrogen atom form a morpholine, pyrrolidine, or piperidine ring, R.sub.4 is H or C.sub.1 -C.sub.4 alkyl or R.sub.2, R.sub.3, and R.sub.4 together with the nitrogen form a piperidine ring, Z is --O-- or --NR.sub.4 -- r is 2 to 4, and X.sup.- is an anion, provided that the nitrogen is from about 40% to 100% salinized, quaternized, or present as amine oxide. The composition used in the method of the present invention is preferably in the form of a dispersion. It is typically employed as an aqueous dispersion. Preferably in the monomer of formula I, R.sub.f is a straight chain prefluoroalkyl group of 2 to about 20 carbon atoms, A is O, and Q is an alkylene of 1 to about 15 carbon atoms. Suitable monomers of formula I include CF.sub.3 CF.sub.2 (CF.sub.2).sub.x C.sub.2 H.sub.4 OC(O)--C(H).dbd.CH.sub.2 or CF.sub.3 CF.sub.2 (CF.sub.2)x C.sub.2 H.sub.4 OC(O)--C(CH.sub.3).dbd.CH.sub.2 wherein x is an even integer of from 2 to about 18, or mixtures thereof. More preferably the monomer of formula I is a perfluoroalkylethyl acrylate or methacrylate, with a perfluorocarbon chain length (R.sub.f) distribution predominantly in the range of 8 to 14 carbons. Such monomers are known and can be prepared by either esterification of the appropriate alcohol CF.sub.3 CF.sub.2 (CF.sub.2).sub.x C.sub.2 H.sub.4 OH, with acrylic acid or methacrylic acid or by tranesterification with methyl acrylate or methyl methacrylate, for example, as described in U.S. Pat. No. 3,282,905. The alcohols are commercially available as mixtures wherein x varies. The proportion of the monomer of formula I is at least 40% relative to the total weight of the copolymer. If it is present in lower amounts, the repellency can be unacceptably poor. The proportion should be less than 90%. If it is present in higher amounts, the amounts of the solubilizing monomer of formula II may be too low, resulting in decreased dispersibility. Preferably the proportion of the monomer formula I is between 50% and 85% by weight, and still more preferably between 65% and 85%, for the best balance of dispersion stability, solubility and repellency performance. The proportion of the monomer of formula IIA or IIB is at least 2% for adequate solubilization. A proportion above 50% could impair oil and water repellency. Preferably the proportion of the monomer of formula II (as salinized, quaternized, or present as amine oxide), by weight is between 5% and 40%, and still more preferably between 15 and 30% for the best balance of properties. Preferably the monomer of formula IIA or IIB is diethylaminoethyl methacrylate. It is at least 40% salinized, ruaternized, or present as amine oxide for adequate solubilizing effect, but may be as high as 100% in this form. The salinization, quaternization or conversion to amine oxide can be performed on the copolymer containing the free amine, or can be carried out on the amine group before polymerization with equally good results. The salinizing group can be an acetate, halide, sulfate or other known salinizing group. The amine salt monomers are prepared by reacting the corresponding tertiary dialkylaminoalkyl acrylate or dialkylaminoalkyl methacrylate ester or corresponding acrylamide or methacrylamide with an organic or inorganic acid, such as hydrochloric, hydrobromic, sulfuric or acetic acid. The tertiary dialkylaminoalkyl acrylate or dialkylaminoalkyl methacrylate esters are known in the art and can be prepared by either reacting a tertiary amine alcohol of the formula, HO(CH.sub.2).sub.r NR.sub.2 R.sub.3 with acryloyl or methacryloyl halide or, preferably, by transesterification with methyl acrylate or methyl methacrylate. The tertiary dialkylaminoalkyl acrylamides or methacrylamides are prepared by acylating the corresponding dialkylaminoalkyl amine with acryloyl or methacryloyl halide in the presence of an acid acceptor such as triethylamine or pyridine. The quaternary ammonium monomers are prepared by reacting the aforesaid acrylate or methacrylate esters of corresponding acrylamide or methacrylamide with a di-(lower alkyl) sulfate, a lower alkyl halide, trimethyl-phosphate or triethylphosphate. Dimethyl sulfate and diethyl sulfate are preferred quaternizing agents. The amide oxide monomers are prepared by reacting the aforesaid acrylate or methacrylate ester or corresponding acrylamide or methyacrylamide with conventional oxidizing agents such as hydrogen peroxide or peracetic acid and the like. The nature of the anion, X.sup.-, in the quaternary ammonium and amine salt monomer is, in general, determined by the method of synthesis. Usually, X.sup.- is an halide ion, such as chloride, bromide, or iodide, or an acetate ion, a sulfate ion, a phosphate ion or an alkylsulfate ion. It is known, however, that quaternary ammonium salts can also be prepared by reacting a tertiary amine with an alkyl ester of benzene or toluenesulfonic acid; in such event, X.sup.- is a benzenesulfonate or toluenesulfonate anion. Up to about 25% by weight of other monomers may optionally be incorporated into the copolymers to provide adhesion to specific substrates, impart film formation properties, provide stability at wider pH ranges, or provide compatibility with added solvents for specific applications. This optional monomer is any polymerizable monomer including but not limited to crosslinkable monomers such as glycidyl (meth)acrylate, (blocked) isocyanatoalkyl-(meth)acrylates, and acrylamides, vinyl monomers such as vinylidene chloride, alkyl (meth)acrylates such as ethylhexyl methacrylate and stearyl methacrylate, ionomers such as (meth)acrylic acid and sulfatoalkyl(meth)acrylates, nonionic water-soluble monomers such as polyoxyethylene (meth)acrylates, and aromatics such as styrene and vinyl toluene. The polymerization of the monomers of formula I and IIA or IIB, and any optional monomer present is conveniently initiated by any free radical initiator inclhulding azo initiators such as 2,2'-azobis(2,4-dimethylvaleronitrile). Such Azo initiators are sold by E. I. du Pont de Nemours and Company, Wilmington, Del., commercially under the name of "VAZO" 67, 52 and 64, and by Wako Pure Industries, Ltd., under the name "V-501". If desired, a chain transfer agent such as dodecyl mercaptan may be added before polymerization. Initiator or chain transfer agent concentration is typically 0.1 to 2% based on the weight of the total monomers. The polymerization step is carried out in a solvent such as acetone, methylisobutyl ketone, ethyl acetate, isopropanol, or other ketones, esters and alcohols or mixtures thereof. After polymerization, the above solvent can be retained in the final composition if required for an intended application, or it can be removed by distillation to form a waterborne composition with a very low volatile organic content. A dispersion of the composition is prepared using conventional means known to those skilled in the art. The method for imparting water, oil, or stain repellency to hard surfaces of the present invention has several advantages over previously known methods. The copolymer composition used in the present invention provides durable water, oil, and stain repellency to a wide variety of hard surfaces. The copolymer composition used in the present invention can be readily dispersed in water without added surfactants, and forms dispersions with very low volatile content, very low flammability, and excellent stability under high shear conditions and high temperatures. The dispersions are easy to apply without requiring a pretreatment, can be applied to damp materials, and cleanup is easy. The dispersions are stable when subjected to freeze/thaw cycling, and have excellent stability at high ionic strength, with consequently excellent stability in hard water. Coatings formed using the method of the present invention do not change the appearance of the coated surface, do not require heating to achieve good oil and water repellency, and are not subject to blistering or peeling because moisture trapped in the surface is allowed to vaporize freely. Due to these advantages the method of the present invention is useful for imparting water, oil, or stain repellency to a wide variety of hard surfaces subject to a variety of adverse conditions. Materials such as brick, stone, wood, concrete, ceramics, tile, glass, stucco, gypsum drywall, particle board or chip board subject to outdoor weathering, cleaners, solvents or oils benefit from the method of the present invention. The repellency benefits provided are suitably durable under the various adverse conditions encountered. The following examples illustrate the preparation of compositions for the inventive process and their use on various hard surfaces. Other methods of preparation will be apparent to those skilled in the art. |
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