MXPA00004914A - Coating compositions containing a highly fluorinated hydroxyl containing additive - Google Patents

Abstract

A coating composition that forms a finish that is soil resistant and easily cleaned having a binder of (A) an acrylic polymer of polymerized hydroxyl containing monomers of hydroxy alkyl (meth)acrylates having 1-4 carbon atoms in the alkyl groups and polymerized monomers from the group of alkyl (meth)acrylates having 1-18 carbon atoms in the alkyl groups, styrene or any mixtures of the above and the acrylic polymer has a weight average molecular weight of about 2,000-20,000 determined by gel permeation chromatography;(B) an acrylic polymeric additive of polymerized hydroxyl containing monomers of hydroxy alkyl (meth)acrylates having 1-4 carbon atoms in the alkyl groups, polymerized monomers from the group of alkyl (meth)acrylates having 1-18 carbon atoms in the alkyl groups, styrene or any mixtures of the above and polymerized fluoro alkyl containing monomer represented by formula (I) where R is selected from the group of hydrogen or an alkyl group having 1-2 carbon atoms, X is a divalent radical and Rf is a fluoro alkyl containing group having 4-20 carbon atoms and the additive has a weight average molecular weight of about 1,000-15,000 determined by gel permeation chromatography;and (C) an organic cross-linking agent;and where a cured layer of the coating of the composition has a combination of advancing water contact angle of at least 100°and a hexadecane advancing contact angle of at least 40°. Articles coated with the composition also are part of this invention.

Description

COMPOSITIONS OF COATING CONTAINING AN ADDITIVE THAT CONTAINS HYDROXY OR HIGHLY FLUORATED BACKGROUND OF THE INVENTION FIELD OF THE INVENTION This invention is concerned with a coating composition of an acrylic polymer and a crosslinking agent such as a polyisocyanate or a melamine crosslinking agent and containing highly fluorinated hydroxyl additive which forms a finish that is relatively free from powder under conditions of external use and is easily cleaned when it is soiled, for example, by washing with water.

DESCRIPTION OF PREVIOUS TECHNIQUE Acrylic polymer-containing coating compositions crosslinked with a polyisocyanate are well known as shown in U.S. Patent 3,558,564 issued to Vasta on January 26, 1971 and U.S. Patent 4,156,678 issued to Krueger on May 29, 1979. Coating compositions of acrylic polymer blends and fluorocarbon constituents containing acrylic polymer forming antifreeze coatings are well known. Clear coatings containing acrylic polymers that have small amounts of fluorocarbon constituents that are applied over REF .: 119024 metal base coatings to provide automotive finishes that have good weather resistance, has high water and oil repellency and stain resistance as shown in Sugimura et al. US Patent 4,812,337 issued March 14, 1989. Fluorinated polyurethanes which are used as powder release agents are shown in U.S. Patent 3,759,874 issued to Gresham on September 18, 1973. Fluorinated isocyanate polyurethanes which are used as adhesives are shown in U.S. Patent 3,972,856 issued to Mitsch et al. August 1976. Protective coatings of fluorinated polyurethanes of fluorinated diols or triols are shown in U.S. Patent 4,782,130 issued to Re, et al. On November 1, 1988. There is a need for an additive containing fluoro carbide that can be added to a conventional coating composition that will form a rec composition A location that is high in solids content, can be applied with conventional equipment and cure to a hard, strong, durable and weather resistant finish without being baked at elevated temperatures and the finish is resistant to fouling and is easily cleaned. Preferably the coating composition has a low content of fluorocarbon constituents that reduces the cost of the composition because the fluorocarbon constituent is expensive.

BRIEF DESCRIPTION OF THE INVENTION A coating composition is described which contains about 45-80% by weight of a binder and 20-55% by weight of a carrier liquid; wherein the binder contains: (A) an acrylic polymer comprising hydroxyl-containing hydroxyl-containing monomers of hydroxy alkyl (meth) acrylates having from 1-4 carbon atoms in the alkyl groups and polymerized monomers selected from the group of (meth) ) alkyl acrylates containing from 1-18 carbon atoms in the alkyl, styrene or any mixture of those mentioned above and the acrylic polymer has a weight average molecular weight of about 2,000-20,000 as determined by gel permeation chromatography , (B) an acrylic polymeric additive of about 10-45% by weight, based on the weight of the additive, of polymerized hydroxyl-containing monomers of hydroxy alkyl (meth) acrylates having from 1-4 carbon atoms in the alkyl groups, 5-80% by weight, based on the weight of the additive, of polymerized monomers of the group of alkyl (meth) acrylates having 1-18 carbon atoms in the alkyl groups, styrene or any mixtures of the aforementioned and 10-50% by weight, based on the weight of the polymerized fluoroalkyl-containing monomer additive which is represented by the formula: CH = CR- COXR wherein R is selected from the group of hydrogen or an alkyl group having 1-2 carbon atoms, X is a divalent radical and Rf is a group containing fluoroalkyl having 4-2C atoms. carbon and the additive has a weight average molecular weight of about 1,000-15,000 determined by gel permeation chromatography, and (C) an organic crosslinking agent; and wherein a cured coating layer of the composition has a combination of advance contact angle to the water of at least 100 ° and a lead contact angle to the hexadecane of at least 40 °. Articles coated with the composition are also part of this invention.

DETAILED DESCRIPTION OF THE INVENTION The coating compositions of this invention are primarily used as a clear coating on a pigmented base coat containing solid color pigments or metal flake pigments or mixtures thereof. The coating composition can also be used as a conventional pigmented mono-coating or coating base composition. Conventional spray equipment can be used to apply these coating compositions which are cured at ambient temperatures or slightly elevated temperatures which decrease the drying time. The resulting finish has excellent luster and image distinction and excellent repellency to dust, water and oil, is easily cleaned by washing with water or a mixture of surfactant with water or can be cleaned by wiping and has good resistance to staining and resistance to the weather. Preferably, the coating composition is a clear coating composition, that is, it does not contain pigments or a small amount of transparent pigment. The composition has a relatively high solids content of about 45-80% by weight of binder and about 20-55% by weight of a carrier which is usually an organic carrier which can be a solvent for the binder or a mixture of solvents and no solvents that would form a non-aqueous dispersion. The composition has a low VOC (volatile organic content) and complies with current pollution regulations. The coating composition when applied to a substrate and fully cured has a water lead contact angle of at least 100 °, preferably 100-120 ° and a hexadecane lead contact angle of at least 40 ° , preferably 45-85 ° and more preferably 60-85 °. The contact angles are measured by the Sessile drop method which is fully described in A.W. Adamson, The Physical Chemistry of Surfaces, 5th Ed., Wiley & Sons, New York, 1990, Chapter II which is incorporated herein by reference. Briefly, in the Sessile drop method, a drop of liquid, either water or solvent, is. placed on a surface and the tangent is determined precisely at the point of contact between the drop and the surface. An advance angle is determined by increasing the size of the liquid drop and a back angle is determined by decreasing the size of the liquid drop. Additional information regarding the equipment and procedure necessary to measure these contact angles are more fully described in R.H. Dettre, R.E. Johnson Jr., Wettability, Ed. By J.C. Berg, Marcel Dekker, New York, 1993, Chapter I which is incorporated herein by reference. The relationship between water contact angles, organic liquid and dust cleaning and retention capacity are described in chapters XII and XIII of A.W. Adamson, mentioned above. In general, the higher the contact angle the more resistant the surface is to dust or fouling and the surface is easier to clean. The coating compositions of this invention have relatively high contact angles and are dust resistant and are easily cleaned. Usually, the coating composition contains about 30-89% by weight, based on the weight of the binder, of an acrylic polymer, 1-20% by weight, based on the weight of the binder, of an acrylic polymeric additive and 10-50% by weight, based on the weight of the binder, of a crosslinking agent. The acrylic polymer used in the coating composition is prepared by a conventional polymerization process in which the monomers, solvents and polymerization initiators are charged in a period of time of between 1-24 hours, preferably in a period of time of between 2-8 hours, to a conventional polymerization reactor wherein the constituents are heated to about 60-175 ° C, preferably about 140-170 ° C. The acrylic polymer formed has a weight average molecular weight of about 2,000-20,000, preferably about 5,000-10,000. The molecular weight referred to herein is determined by gel permeation chromatography using polystyrene as the standard. Typical polymerization initiators that are used in the process are initiators of the azo type such as azo-bis-isobutyronitrile, 1,1'-azo-bis (cyanocyclohexane), peroxy acetates such as t-butyl peracetate, peroxides such as di-t-butyl peroxide, benzoates such as t-butyl perbenzoate, octoates such as t-butylperoctoate and the like. Typical solvents that may be used in the process are ketones such as methyl amyl ketone, methyl isobutyl ketone, methyl ethyl ketone, aromatic hydrocarbons such as toluene, xylene, alkylene carbonates such as propylene carbonate, n-methyl pyrrolidone, ethers, esters, acetates and mixtures of any of those mentioned above. Typical polymerizable monomers that are used to form acrylic polymer are alkyl (meth) acrylates, this means alkyl acrylates and alkyl methacrylates, having 1-18 carbon atoms in the alkyl group such as methyl methacrylate, ethyl acrylate , ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl methacrylate, butyl acrylate, isobutyl methacrylate, butyl methacrylate, t-butyl methacrylate, pentyl acrylate, pentyl methacrylate, hexyl acrylate, hexyl methacrylate , octyl acrylate, octyl methacrylate, nonyl acrylate, nonyl methacrylate, decyl acrylate, decyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, other useful monomers are styrene, alpha methyl styrene , acrylamide, methacrylamide, acrylonitrile, hydroxy methacrylamide and the like; or any mixtures of these monomers and hydroxy alkyl (meth) acrylates ie hydroxy alkyl acrylates and hydroxy alkyl methacrylates having from 1-4 carbon atoms in the alkyl groups such as hydroxy methyl acrylate, hydroxy ethyl methacrylate , hydroxy ethyl acrylate, hydroxy ethyl methacrylate, hydroxy propyl methacrylate, hydroxy propyl acrylate, hydroxy butyl acrylate, hydroxy butyl methacrylate and the like. Preferred acrylic polymers which form high quality coatings contain polymerized monomers of an alkyl methacrylate having from 2-6 carbon atoms in the alkyl group, an alkyl acrylate having from 2-8 carbon atoms in the alkyl group, an hydroxy alkyl acrylate having 2-4 carbon atoms in the alkyl and styrene group. A particularly preferred polymer contains butyl methacrylate, butyl acrylate, styrene and hydroxy propyl acrylate. The acrylic polymer additive used in the coating composition is prepared in a manner similar to the above acrylic polymer in a conventional polymerization process wherein the monomers, except the fluoroalkyl-containing monomer, solvent and polymerization initiator are charged over a period of time of 1-24 hours, preferably in a period of 2-8 hours, in a conventional polymerization reactor in which the constituents are heated to about 60-175 ° C, preferably about 140-170 ° C. The polymer formed has a weight average molecular weight of about 1,000-15,000, preferably about 1,000-10,000. The aforementioned polymerization initiators, solvents and the other above monomers such as alkyl (meth) acrylate, hydroxy alkyl (meth) acrylate can and / or styrene can be used to prepare the additive including acrylamide, methacrylamide, acrylonitrile, hydroxy methacrylamide and the like. The polymeric acrylic additive contains about 10-45% by weight of hydroxy alkyl (meth) acrylate, 5-80% by weight of another alkyl (meth) acrylate mentioned above, styrene and the like and 10-50% of monomers which contain fluoroalkyl. The fluoroalkyl-containing monomers that are used in the acrylic polymeric additive are represented by the formula: wherein R is hydrogen or an alkyl group having 1-2 carbon atoms, X is a divalent radical, preferably a hydrocarbon group having 2-20 carbon atoms and more preferably X is - (CH2) n - wherein n is an integer of 1-18 and Rf is a fluoroalkyl-containing group having 4-20 carbon atoms and preferably a straight-chain or branched-chain fluoroalkyl group having 4-20 carbon atoms that optionally it may contain an oxygen atom. Commonly useful fluoroalkyl-containing monomers are perfluoro methyl ethyl methacrylate, perfluoro propyl ethyl methacrylate, perfluoro butyl ethyl methacrylate, perfluoro pentyl ethyl methacrylate, perfluoro hexyl ethyl methacrylate, perfluoro octyl ethyl methacrylate, perfluoro decyl ethyl methacrylate, perfluoro lauryl ethyl methacrylate, perfluoro stearyl ethyl methacrylate, perfluoro methyl ethyl acrylate, perfluoro ethyl ethyl acrylate, perfluoro butyl ethyl acrylate, perfluoro pentyl ethyl acrylate, perfluoro hexyl ethyl acrylate, perfluoro octyl ethyl acrylate, perfluoro decyl ethyl, perfluoro lauryl ethyl acrylate, perfluoro stearyl ethyl acrylate and the like. More preferred are perfluoro alkyl ethyl methacrylates, wherein the perfluoroalkyl group contains 4-20 carbon atoms. Other useful fluoroalkyl-containing monomers are represented by the formula: wherein: R is as defined above, R1 is a fluoroalkyl group containing 4-12 carbon atoms, R2 is an alkyl group containing 1-4 carbon atoms and n is an integer of 1-4. Typical of these monomers are the following: CH, O C8FI7S02N (CH2) 2- O- C- CH = CH2 Preferred acrylic polymeric additives which form a high quality coating contain polymerized monomers of an alkyl methacrylate having from 2-6 carbon atoms in the alkyl group, an alkyl acrylate having from 2-8 carbon atoms in the alkyl group, a hydroxy alkyl acrylate having 2-4 carbon atoms in the alkyl, styrene and perfluoroalkyl ethyl methacrylate group having 4-20 carbon atoms in the alkyl group. A particularly preferred polymer contains butyl methacrylate, butyl acrylate, styrene, hydroxy propyl acrylate and the above-mentioned perfluoroalkyl-containing monomer. Other useful acrylic polymeric additives contain polymerized monomers of an alkyl methacrylate having from 2-6 carbon atoms in the alkyl group, an alkyl acrylate having from 2-8 carbon atoms in the alkyl, styrene, alkylene methacrylate group glycol and a perfluoro alkyl ethyl methacrylate having 4-20 carbon atoms in the alkyl group. Other useful polymeric additives contain butyl methacrylate, butyl acrylate, hydroxy propyl acrylate, ethylene triglycol methacrylate and the perfluoro alkyl ethyl methacrylate monomer mentioned above. The coating composition contains an organic crosslinking agent capable of crosslinking with the hydroxyl groups of the polymeric additive and the acrylic polymer. Preferably, an organic polyisocyanate crosslinking agent or an alkylated melamine crosslinking agent. Any of the aromatic, aliphatic, conventional cycloaliphatic isocyanates, trifunctional isocyanates and isocyanate functional adducts of polyols and diisocyanates can be used. Typically useful diisocyanates are 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-biphenylene diisocyanate, toluene diisocyanate, biscyclohexyl diisocyanate, tetramethylene xylene diisocyanate, ethyl ethylene diisocyanate, 2,3- diisocyanate. dimethyl ethylene, 1-methyltrimethylene diisocyanate, 1,3-cyclopentylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-phenylene diisocyanate, 1,5-naphthalene diisocyanate, bis- (4-isocyanatocyclohexyl) -methane , 4-4 '-diisocyanate diphenyl ether and the like. Typical trifunctional isocyanates that may be used are triphenylmethane triisocyanate, 1,3-benzene triisocyanate, 2,4,5-toluene triisocyanate and the like. Oligomers of diisocyanates such as the trimer of hexamethylene diisocyanate which is sold under the tradename of "Desmodur" N-3390 can also be used. Isocyanate-functional adducts can be used which are formed from an organic polyisocyanate and a polyol. Any of the aforementioned polyisocyanates can be used with a polyol to form an adduct. Polyols such as trimethylol alkanes such as trimethylolpropane or ethane can be used. A useful adduct is the reaction product of tetramethylxylidine diisocyanate and trimethylol propane and is sold under the tradename "Cythane" 3160. A fluorinated organic polyisocyanate crosslinking agent which is an adduct of a fluorinated monofunctional alcohol and one of the organic polyisocyanates conventional aforementioned can also be used. Approximately 0.1-33 mole percent of isocyanate active groups of one of the polyisocyanate are reacted with the fluorinated monofunctional alcohol to form fluorinated organic polyisocyanate. Typically, the constituents are reacted with a catalyst for about 0.1-4 hours at a temperature of about 50-120 ° C to form the adduct. Typical fluorinated monofunctional alcohols used to form the functional isocyanate adducts are represented by the formula: wherein Rf is a fluoroalkyl-containing group having at least 4 carbon atoms and preferably a straight chain or branched chain fluoroalkyl group having 4-20 carbon atoms which optionally may contain oxygen atoms as ether groups or may contain 1-5 chlorine atoms or 1-5 hydrogen atoms. Preferably, Rf is a perfluoroalkyl group containing 4-20 carbon atoms. Y is a divalent radical, preferably -CH2CH20-, -S02N (R4) CH2CH20-, -CH2-, -0-, CH20- wherein R4 is an alkyl group preferably containing 1-4 carbon atoms, R3 is H or an alkyl group having 1-4 carbon atoms, H and methyl are preferred, n is 0-1 and m is 1-30, provided that if n is 0, then m must be greater than or equal to; if Y is -O-, m must be greater than or equal to 1; m is preferably 1-20. The following are preferred fluorinated monofunctional alcohols: wherein Rf is a perfluoroalkyl group having 6-12 carbon atoms and n is 5-15; H- (CF2CF2) -CH2OH where n is 1-6 / wherein R5 is an alkyl group having 1-4 carbon atoms and n is 1-30; CF3- (0-? C-3 CF2) -O- (CH-CH-0) m-H F wherein n is 0-10 and m is 1-20; Y ^ ^ n2 < ~ n2 where Rf is as described above. Alkylated melamine crosslinking agents can be used in the composition. These crosslinking agents are generally partial or fully alkylated melamine formaldehyde compounds which can be monomeric or polymeric and if they are polymeric have a degree of polymerization of about 1-3. The typical alcohols used to alkylate these resins are methanol, ethanol, propanol, butanol, isobutanol and the like. Typically useful alkylated melamine crosslinking agents are commercially available and include the following: Cymel® 301, 350, 373, 385, 1161 or 1168, or Resimine® 714, 730, 731, 735 and 745. Usually, a strong acid catalyst or its salt is added in an amount of approximately 0.1-3% by weight, based on the weight of the binder, to reduce the temperature, of curing. Para-toluenesulfonic acid, dadecylbenzenesulfonic acid, phosphoric acid or the amine or ammonium salts of these acids can be used. To improve the weather resistance of a clear coating composition of about 0.1-10% by weight, based on the weight of the binder, of ultraviolet light stabilizers, filters, quenchers and antioxidants are usually added. Typically, ultraviolet light filters and stabilizers include the following: Benzophenones such as hydroxy dodecyl oxy benzophenone, 2,4-dihydroxy benzophenone, hydroxy benzophenones containing sulphonic acid groups and the like. Benzoates such as diphenylol propane dibenzoate, diphenylol propane benzoate butyl tertiary and the like. Triazines such as 3, 5-dialkyl-4-hydroxy phenyl triazine derivatives, sulfur-containing derivatives of dialkyl-4-hydroxy phenyl triazine, hydroxy phenyl-1,3,5-triazine and the like. Triazoles such as 2-phenyl-4- (2,2'-dihydroxybenzoyl) -triazole, substituted benzotriazoles such as hydroxy-phenyltriazole and the like. Hindered amines such as bis (1, 2, 2, 6, 6-pentamethyl-4-piperidinyl sebacate), di [4 (2, 2, 6, 6, tetramethyl piperidinyl)] sebacate and the like and any mixtures of any of the previous ones. When an isocyanate crosslinking agent is used, the coating composition contains a sufficient amount of a catalyst to cure the composition at ambient temperatures. In general, about 0.01-2% by weight, based on the weight of the binder, of catalyst of one of the following catalysts is used for a polyisocyanate crosslinking agent: triethylene diamine, alkyl tin laurates such as dibutyl tin dilaurate, diacetate of dibutyl tin, tertiary amines and the like. The preferred is dibutyltin dilaurate. In generalAgents flow control are I used in the composition in amounts of about 0.1-5% by weight, based on the weight of the binder, such • as polyacrylic acid, polyalkylacrylates, copolymers of dimethyl polysiloxane polyether modified and polydimethyl siloxane modified polyester . When the coating composition is used as a clear coating composition usually on a pigmented base coat, it may be desirable to use pigments in the coating composition having the same refractive index as the dry coating. Normally useful pigments have a particle size of about 0.015 to 50 microns and are used in a weight ratio of pigment to binder of about 1: 100 to 10: 100 and are inorganic siliceous pigments such as silica pigment having an index of refraction of approximately 1.4-1.6. It is highly desirable to use at least some fluorinated organic polyisocyanate crosslinking agent, as described above, in the pigmented basecoat over which the clear coating of this invention is applied to significantly reduce cratering in the basecoat. Usually, about 5-40% by weight, based on the weight of the binder, the fluorinated polyisocyanate is used in the basecoat. When the coating composition is used as a clear coating on a vehicle such as a car, truck, bus, train or on construction equipment, industrial equipment, structures such as tanks, bridges, exterior or interior of buildings, a base coating that can be a solvent-based or water-based composition is first applied and then the clear coating is usually applied by conventional means such as spraying or electrostatic spraying. The clear coating is dried and cured at ambient temperatures but moderately high temperatures of up to about 90 ° C can be used to shorten the drying time. The coating composition can be used as a conventional pigmented coating composition containing pigments in a pigment-to-binder ratio of about 0.1 / 100-100 / 100. The composition can be used to coat any of the aforementioned articles and substrates and provides a finish that has good luster and is resistant to weather, hard and tough. The following examples illustrate the invention.

All parts and percentages are on a weight basis unless otherwise specified. The molecular weight is determined by gel permeation chromatography using polystyrene as the standard.

EXAMPLE 1 A solution of fluorinated acrylic polymeric additive A was prepared by charging the following constituents in a reactor equipped with a heat source, a thermometer and a stirrer.

Serving 1 Parts in weight Methyl amyl ketone 465.83 Portion 2 Monomer of butyl methacrylate (BMA) 368.10 Styrene monomer (S) 204.51 Hydroxy propyl acrylate monomer 521.43 (HPA) Fluoro alkyl methacrylate monomer 272.67 ethyl (FAMA) - (fluoroalkyl group containing C-4 approximately 5%, C-6 approximately 30%, C-8 approximately 30%, C-10 approximately 20%, C-12 approximately 10%, C-14 approximately 5%) Methyl amyl ketone 3.14 Serving 3 Peroxy Acetate of T-butyl 45.93 Methyl amyl ketone 76.27 Portion 4 Methyl amyl ketone _ 42.12 Total 2,000.00 Portion 1 was charged to the reaction vessel and completely covered with nitrogen and Portion 2 was premixed and added for a period of 240 minutes while retained the resulting mixtat its reflux temperatof about 150 ° C. Portion 3 was premixed and added at the same time as portion 2 to the reaction mixtfor a period of 255 minutes and then portion 4 was added and the reaction mixtwas maintained at its reflux temperatfor an additional 60 minutes. . The resulting polymer solution was cooled to room temperat Solution A of the resulting fluorinated acrylic polymeric additive has a solids content by weight of about 70%, a polymer of BMA / S / HPA / FAMA in the following percentages 26.9% / 15.0% / 38.2% / 19.9% and the polymer has a weight average molecular weight of about 4,500. A solution B of fluorinated acrylic polymeric additive was prepared using the same constituents and process except that the proportion of monomers was changed and the resulting polymer has the following composition BMA / S / HPA / FAMA 17% / 15% / 38% / 30% An acrylic polymer solution I was prepared by charging the following constituents in a reactor equipped with a heat source, a thermometer and a stirrer: Serving 1 Parts in weight Methyl amyl ketone 699.20 Portion 2 Monomer of butyl methacrylate (BMA) 583.80 Styrene monomer (S). 307.28 Butyl acrylate monomer (BA) 343.20 Hydroxy propyl acrylate monomer 783.60 (HPA) Methyl amyl ketone 4.72 Portion 3 Peroxy T-butyl acetate 69.01 Methyl amyl ketone 114.59 Portion 4 Methyl amyl ketone 33.28 Total 2,938.68 Portion I was charged to the reaction vessel and was completely covered with nitrogen and portion 2 was premixed and added for a period of 240 minutes while retaining the resulting mixtat its reflux temperatof about 150 ° C. Portion 3 was premixed and added at the same time as portion 2 to the reaction mixtfor a period of 255 minutes and then portion 4 was added and the reaction mixtwas maintained at its reflux temperatfor an additional 60 minutes. . The resulting polymer solution was cooled to room temperat The resulting acrylic polymer solution I has a solids content by weight of about 70%, a polymer of BMA / S / BA / HPA at the following percentages 30% / 15% / 17% / 38% and the polymer has a weight average molecular weight of approximately 7,000. A clear acrylic composition I was prepared as follows: Serving 1 Parts in weight Methyl ethyl ketone 2.54 Toluene 2.67 Ester dibasic acid (ester mixtof 1.79 adipic acid, glutaric acid and succinic acid Butyl acetate Cellosolve 4.96 Portion 2 Solution I of acrylic polymer (prepared 72.79 above) Portion 3 Resilient S (polymer flow additive 0.35 acrylic) "Tinuvin" 328-2- (2-hydroxy-3, 5-diterciary 5.58 amyl phenol) -2H-benzotriazole) "Tinuvin" 292- (1, 2, 2, 6, 6-pentamethyl-4- 0.87 piperidinyl) sebacate Dibutyl tin dilaurate 0.92 Acetate PM 7.38 Total 100.00 The constituents of portion I were charged into a mixing vessel in the order shown with continuous mixing. Portion 2 was added and mixed for 15 minutes. The constituents of portion 3 were charged into the mixing vessel in the order shown with constant mixing. The resulting composition has a solids content of approximately 53.5%. A clear coating composition I (control) was prepared by mixing the clear acrylic composition I mentioned above with a polyisocyanate solution in a volume ratio of 3/1. The polyisocyanate solution contains 90% by weight of the trimer of hexamethylene diisocyanate and 10% by weight of a solvent of n-butyl acetate / solvent Aromatic 100 in a ratio of 1: 1. The clear coating compositions A and B were prepared by mixing the clear coating composition I above with respectively 2.0% and 5.0% by weight of a solution A of fluorinated acrylic polymeric additive, prepared above. Similarly, clear coating compositions C and D were prepared by mixing the above clear coating composition with respectively 2.0% and 5.0% by weight of a solution B of fluorinated acrylic polymeric additive, prepared above. A set of two cold rolled, phosphatized steel panels that have been. Coated with a cured electrocoat primer composition of a crosslinked resin of a polyepoxy hydroxy ether with a polyisocyanate were coated by spraying with a white base coat composition of an acrylic polymer containing an organic polyisocyanate crosslinking agent at a film thickness dry about 18-23 microns. The base coat is allowed to remain approximately 10 minutes to allow the solvent to evaporate and then the above prepared clear coating composition I (control) was applied by spraying. Two coatings were applied with a solvent evaporation time of 2 minutes between the application of each coating. The resulting film was dried at about 83 ° C for about 30 minutes. The dry film thickness of the clear coating was about 44-56 microns. The resulting clear coating was smooth and essentially crater-free and has an excellent appearance. The clear coating compositions A-D were applied in the same manner to separate the phosphatized steel panels coated with primer and basecoat as mentioned above. In each case, the resulting clear coating was smooth and essentially free of craters and has an excellent appearance. The following tests were carried out in each of the panels and the results are shown in Table I: forward and backward contact angles for water and hexadecane. Luster measured at 20 ° Distinction of image DOI Fog Hardness (measured in knoops) L, a, b, values of color angle Test of resistance to soiling Resistance to fouling test A soil substitute was prepared by mixing 10 g of Nujol (mineral oil), 20 g of carbon black, 500 ml of heptane and 1 liter of polymeric beads "Surlyn" (polymer of an acrylic ionomer). The resulting suspension was completely mixed and then the heptane solvent was distilled using a vacuum distiller. A polyvinyl chloride tube 2.54 cm long and 7.62 cm outer diameter was placed on the surface of a test panel. Three grams of the soil substitute prepared above were poured into the tube and rolled gently on the surface of the test panel for a total of fifty rotations. The soil substitute was poured and the tube segment was removed. The test panel was then bent sharply twice on the side of a garbage can to remove the slightly adhering dust. The amount of excess powder in the panel was measured in delta E units with a color analyzer. The data in Table I show that clear coating compositions A-D containing a fluorinated acrylic polymeric additive have a higher contact angle for water and for hexadecane as compared to control which does not contain the additive. The fouling resistance test shows that the AD coating compositions containing the fluorinated acrylic polymeric additive provide a finish which is resistant to fouling and is also easily washed or cleaned by wiping as compared to the clear coating composition made from the control which does not contain a fluorinated acrylic polymeric additive. The control has low contact angles and exhibits poor fouling resistance in the fouling resistance test and poor cleaning ease. All coating compositions with and without the fluorinated acrylic polymeric additive have comparable luster, image distinction, fog and hardness and have an acceptable color.

EXAMPLE 2 A clear coating composition E was prepared by mixing together the following constituents: Parts by weight Solution I of acrylic polymer 215. 4 (prepared in Example 1) "Cymel" 1168 80.1 (alkylated melamine formaldehyde resin) Solution B of fluorinated acrylic polymeric additive 10.7 (prepared in Example 1) Catalyst (aromatic sulfonic acid in isopropanol) 1.8 Total 308.0 Composition E of clear coating was applied in the same manner as in Example 1 to phosphatized steel panels coated with an electrocoating primer and a basecoat as described in Example 1 and cured to provide a clear coating that was smooth, essentially free of craters and has an excellent appearance. The panels were tested as in example 1 and the test results are shown in table I. ? * forward / backward contact angle for water and hexadecane

Claims (1)

CLAIMS 1. A coating composition containing from about 45-80% by weight of a binder and 20-55% by weight of a carrier liquid; characterized in that the binder comprises: (A) an acrylic polymer comprising polymerized hydroxyl-containing monomers consisting of hydroxy alkyl (meth) acrylates having from 1-4 carbon atoms in the alkyl groups and polymerized monomers selected from the group of (meth) alkyl acrylates containing from 1-18 carbon atoms in the alkyl, styrene or any mixture of the above groups and the acrylic polymer has a weight average molecular weight of about 2,000-20,000 as determined by gel permeation chromatography , (B) an acrylic polymeric additive consisting essentially of about 10-45% by weight, based on the weight of the additive, of polymerized hydroxyl-containing monomers consisting of hydroxy alkyl (meth) acrylates having 1-4 carbon atoms in the alkyl groups, 5-80% by weight, based on the weight of the additive, of polymerized monomers selected from the group consisting of ( met) alkyl acrylates having 1-18 carbon atoms in the alkyl, styrene or any mixtures of those mentioned above and 10-50% by weight, based on the weight of the monomer additive containing polymerized fluoroalkyl which is represented by the formula: O wherein R is selected from the group consisting of hydrogen or an alkyl group having 1-2 carbon atoms, X is a divalent radical and Rf is a fluoroalkyl containing group having 4-20 carbon atoms and the additive has a weight average molecular weight of about 1, 000-15, OOO determined by gel permeation chromatography, and (C) an organic crosslinking agent; and wherein a cured coating layer of the composition has a combination of advance contact angle to water of at least 100 ° and a lead contact angle to the hexadecane of at least 40 °. 2. The coating composition according to claim 1, characterized in that the fluoroalkyl-containing monomer is represented by the formula: wherein R is as defined in claim 1, n is an integer of 1-11 and Rf is a straight or branched chain fluoroalkyl group having 4-20 carbon atoms. 3. The coating composition according to claim 2, characterized in that the acrylic polymeric additive consists essentially of polymerized monomers of an alkyl methacrylate having 2-6 carbon atoms in the alkyl group, an alkyl acrylate having 2-8 carbon atoms in the alkyl group, a hydroxy alkyl acrylate having 2-4 carbon atoms in the alkyl group, styrene and a fluoroalkyl-containing monomer, wherein R is CH3, n is 2 and Rf is a fluoro group alkyl having 4-20 carbon atoms and the crosslinking agent is an organic polyisocyanate crosslinking agent and the cured layer of the composition has a water-to-water contact angle of 100-120 ° and an advancing contact angle to the hexadecane of 45-85 °. 4. The coating composition according to claim 3, characterized in that the acrylic polymeric additive consists essentially of butyl methacrylate, butyl acrylate, styrene, hydroxy propyl acrylate and the fluoroalkyl-containing monomer. 5. The coating composition according to claim 1, characterized in that the fluoroalkyl-containing monomer is represented by the formula: R2 OI li R1 -S? 2-N- (CH2) noC-CR = CH2 wherein R is defined in claim 1, R1 is a fluoroalkyl group having 4-12 carbon atoms, R2 is an alkyl group which has 1-4 carbon atoms and n is an integer of 1-4. 6. The coating composition according to claim 1, characterized in that the crosslinking agent is an organic polyisocyanate selected from the group of aromatic diisocyanate., aliphatic diisocyanate, cycloaliphatic diisocyanate, aromatic triisocyanate, aliphatic triisocyanate or an oligomer of a diisocyanate. The coating composition according to claim 1, characterized in that the crosslinking agent is a fluorinated organic polyisocyanate of a fluorinated monofunctional alcohol adduct and an organic polyisocyanate wherein the fluorinated monofunctional alcohol is represented by the formula: wherein Rf is a group containing fluoroalkyl having at least 4 carbon atoms, X is a divalent radical, R3 is H or an alkyl group having 1-4 carbon atoms, n is 0-1 and m is 1- 30, provided that when n is 0, then m must be equal to or greater than 1, and where about 0.1-33 mole percent of active isocyanate groups are reacted with the fluorinated monofunctional alcohol. 8. The coating composition according to claim 1, characterized in that the crosslinking agent is an alkylated melamine formaldehyde crosslinking agent. 9. The coating composition according to claim 1, characterized in that it contains pigment in a pigment-to-binder ratio of about 0.1 / 100-100 / 100. The composition according to claim 1, characterized in that it contains about 45-80% by weight of a binder and 20-55% by weight of an organic liquid carrier; wherein the binder comprises: (A) about 30-89% by weight, based on the weight of the binder, of an acrylic polymer consisting essentially of about 20-50% by weight, based on the weight of the acrylic polymer, of polymerized hydroxyl-containing monomers consisting of hydroxy alkyl (meth) acrylates having 1-4 carbon atoms in the alkyl groups and 50-80% by weight, based on the weight of the acrylic polymer of polymerized monomers selected from the group consisting of of alkyl (meth) acrylates having 1-18 carbon atoms in the alkyl, styrene or any mixture of the above groups and the acrylic polymer has a weight average molecular weight of about 2,000-20,000 as determined by gel permeation chromatography , (B) about 1-20% by weight, based on the weight of the binder, of an acrylic polymeric additive consisting essentially of about 10-45% by weight, based on the weight of the additive, of polymerized hydroxyl-containing monomers consisting of hydroxy alkyl (meth) acrylates having 1-4 carbon atoms in the alkyl groups, 5-80% by weight, based on the weight of the acrylic polymer, of polymerized monomers selected from the group which consists of alkyl (meth) acrylates, having 1-18 carbon atoms in the alkyl, styrene or any mixtures of the above groups and 10-50% by weight, based on the weight of the additive, of fluoroalkyl-containing monomer polymerized represented by the formula: wherein R is selected from the group consisting of hydrogen or an alkyl group having 1-2 carbon atoms, n is an integer of 1-11 and Rf consists of a group containing straight or branched chain fluoroalkyl having 4-20 carbon atoms and the acrylic polymer has a weight average molecular weight of about 1,000-10,000, determined by gel permeation chromatography and (C) about 10-50% by weight, based on the weight of the binder, an organic polyisocyanate crosslinking agent selected from the group consisting of aromatic diisocyanate, aliphatic diisocyanate, cycloaliphatic diisocyanate, aromatic triisocyanate, aliphatic triisocyanate or an oligomer of a diisocyanate and wherein a cured coating layer of the composition has a combination of 100-120 ° water advance contact and a hexadecane advance contact angle of 40-85 °. 11. The coating composition according to claim 1, characterized in that it contains about 0.1-10% by weight, based on the weight of the binder, of an ultraviolet light stabilizer or an antioxidant or mixtures thereof. 12. A substrate coated with a dry and cured layer of the composition of claim 1. 13. A substrate coated with a pigmented base coat which is coated with a clear layer of the cured dry composition of claim

1. CONTAINS HIGHLY FLUORID HYDROXYL SUMMARY OF THE INVENTION A coating composition is described which forms a finish which is resistant to fouling and is easily cleaned, having a binder of (A) an acrylic polymer of polymerized hydroxyl-containing monomers of alkyl (meth) acrylates having 1-4 carbon atoms in the alkyl groups and polymerized monomers of the group of alkyl (meth) acrylates having 1-18 carbon atoms in the alkyl, styrene or any mixture of the above groups and the acrylic polymer has a molecular weight weight average of approximately 2,000-20,000 determined by gel permeation chromatography; (B) an acrylic polymeric additive of polymerized hydroxyl-containing monomers of hirdoxy alkyl (meth) acrylates having 1-4 carbon atoms in the alkyl groups, polymerized monomers of the group of alkyl (meth) acrylates having 1 to 4 carbon atoms; -18 carbon atoms in the alkyl groups, styrene or any mixture of the above and polymerized fluoroalkyl-containing monomer represented by the formula (I), wherein R is selected from the group of hydrogen or an alkyl group having 1-2 atoms of carbon, X is a divalent radical and Rf is a fluoroalkyl-containing group having 4-20 carbon atoms and the additive has an average weight-in-weight molecular weight of about 1,000-15,000 determined by gel permeation chromatography; and (C) an organic crosslinking agent; and wherein a cured layer of the coating of the composition has a combination of advance contact angle with water of at least 100 ° and a lead contact angle with hexadecane of at least 40 °. Articles coated with the composition are also part of this invention.