MX2008009773A - Coating system for cement composite articles - Google Patents

Abstract

Acoated article which includes a cement fiberboard substrate and a radiation-curable coating system applied to the substrate. The coating system includes one or more olefinic compounds and one or more PVC dispersion resins, and may be provided in the form of one or more coating compositions that may be applied in one or more layers.

Description

COATING SYSTEM FOR ARTICLES OF CEMENT COMPOSITIONS BACKGROUND OF THE INVENTION Articles of cement compositions are becoming increasingly common for use in building materials. Many of these items are prepared from inexpensive materials, such as cement, wood fibers (cellulose), natural fibers (glass) and polymers. These articles are usually prepared in the form of cement fiberboard substrates such as panels or wallboards. The substrate or articles can be made using methods such as extrusion or using a Hatschek machine. In northern climates, damage from the repeated freezing and thawing of adsorbed water on substrates of cement fiber boards represents a significant problem. Continuous exposure to moisture, freeze-thaw cycles, UV exposure and atmospheric carbon dioxide can cause physical and chemical changes in articles made from cement fiberboard compositions over time. Coating systems or coating compositions can prevent exposure to elements such as UV light, carbon dioxide and water, or they can help reduce the damage that can occur due to the exposure of these Ref: 194429 elements. Several such systems are available to protect items of fiber cement boards. However, there is a need for coating systems and coating compositions that provide a superior seal, have the ability to cure quickly or can provide improved results when an article coated with the composition is subjected to wet adhesion tests and multiple freeze cycles. - defrosting. BRIEF DESCRIPTION OF THE INVENTION The present invention provides in one aspect a coated article comprising a cement fiber board substrate and a radiation curable coating system applied to the substrate, wherein the coating system comprises one or more olefinic compounds and one or more polyvinyl chloride (PVC) dispersion resins. The coating system described may be applied in one or more layers, may be substantially free of solvents or volatile carriers, or may optionally include a photoinitiator system. In another aspect, the invention provides a method for preparing a coated article, which method comprises providing a cement fiber board substrate, coating at least a portion of the substrate with the coating system described above and curing by radiation the coating. The above summary of the present invention is not intended to describe each described embodiment or each implementation of the present invention. The following description more particularly exemplifies illustrative modalities. At various locations throughout the application, a guide is provided through lists of examples, examples of which can be used in various combinations. In each case, the aforementioned list only serves as a representative group and should not be construed as an exhaustive list. The details of one or more embodiments of the invention are presented in the appended figure and the following description. Other features, objects, and advantages of the invention will be apparent from the description and the figure, and from the claims. BRIEF DESCRIPTION OF THE FIGURE Figure 1 is a cross-sectional view of a coated cement fiber article. Similar reference symbols in the various figures in the illustration indicate similar elements. The elements in the illustration are not to scale. DETAILED DESCRIPTION OF THE INVENTION The terms "a", "an", "the, the, the,", "at least one" and "one or more" are used interchangeably.

The mention of numerical ranges by endpoints includes all the numbers included within the range (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc. ). The term "comprises" and variations thereof does not have a limiting meaning in which the terms appear in the description or in the claims. Thus, for example, a composition comprising a wax compound means that the composition includes one or more wax compounds. The terms "acrylate esters" and "methacrylate esters" refer to esters of acrylic acid and esters of methacrylic acid, respectively. They may be cited as (meth) acrylates or (meth) acrylate esters. The term "olefinic compound" refers to any monomer, oligomer or polymer containing reactive ethylenic unsaturation, such as vinyls (meth) acrylates, vinyl ethers, allylic ethers, vinyl esters, unsaturated oils (including mono, di and triglycerides), acids unsaturated fatty acids, and the like. The term "olefinic group" refers to the reactive ethylenic unsaturated functional group in an olefinic compound. The term "reactive sites" or "reactive groups" refers to a group that can react to form a covalent bond that binds or otherwise binds two or more molecules. The present invention provides a system of coating for a cement fiber board substrate, such as a product of wallboard of cement fiberboard or other article of cement composition. The coating system is a radiation curable coating system applied to the substrate, wherein the coating system includes one or more olefinic compounds and one or more PVC dispersion resins. The coating system disclosed includes one or more coating compositions that can be applied in one or more layers. With reference to Figure 1, a coated article 10 of the present invention is shown in a schematic cross-sectional view. The article 10 includes a cement fiber board substrate 12. The substrate is typically very heavy and may for example have a density from about 1 to about 1.6 g / cm3 or more. The first main surface 12 of the substrate 12 may be embossed with small peaks or ridges 16 and valleys 18, for example, in order to resemble coarse sawn wood. The main surface 12 may have a variety of other surface configurations, and may resemble a variety of construction materials other than coarse sawn wood. The layer or layers 20 of the described coating system are placed at the top and partially penetrate the surface 14, and are applied desirably to article 10 at the site where article 10 is made. Layers 20 help protect substrate 12 against one or more of exposure to moisture, freeze-thaw cycles, UV exposure or atmospheric carbon dioxide. The layers 20 can also provide a firmly adhered base layer on which one or more firmly adhered layers of final top cover 22 can be formed. The final top cover 22 is desirably both decorative and weather resistant, and can be applied to article 10 in the site where article 10 is manufactured after article 10 has been attached to a building or other surface. The described articles can be coated on one or more surfaces with the described radiation curable coating system. The coating system includes one or more coating compositions that can be applied in one or more layers. Coating systems can be provided in a variety of modalities. In an exemplary embodiment, the coating system includes a first coating composition that includes at least one olefinic compound, and a second coating composition that includes at least one PVC dispersion resin. The two coating compositions can be applied to the substrate sequentially or concurrently and cured sequentially or simultaneously using radiation. In another exemplary embodiment the coating system includes at least one olefinic compound and at least one PVC dispersion resin, and can be applied to the substrate and cured using radiation. The coating systems described have particular utility for coating the undersurface of a cement fiber board items while being transported on a transport system (eg, belts, rolls, air tables or the like), as described in the PCT application also pending of the applicant Serial No. (Proxy Control No. 160-P-793 O01) filed the same day together with the present and entitled METHOD FOR COVERING A CEMENT FIBER BOARD ARTICLE. The olefinic compound is the described coating systems seems to work as a reactive penetrant. This can be better appreciated by observing the coating system after it is applied to the substrate but before the radiation curing is performed. The olefinic compound appears to improve wetting or penetration, and may help introduce other components into the coating system within the pores in the substrate. The olefinic compound also appears to help the cured coating adhere to the substrate after curing. PVC dispersion resin seems to limit wetting or penetration, and can help prevent other components from penetrating very deeply into the coating system within the pores in the substrate that can not be adequately cured by radiation. The PVC dispersion resin also appears to help the subsequently applied coatings (e.g., topcoat) adhere to the coated substrate. Preferred coating systems may also include one or more of the following additional features: - increasing the resistance of the article to water pick-up (within the article); - increase the surface integrity of the article (for example, by acting to reinforce the fiber and cement matrix similar to a binder in other composite materials); protect against the expansion of the article under freezing / thawing conditions; or - increasing the integrity of the edges of the article by joining the layers of the fiber together. A variety of cement fiberboard substrates may be employed in the articles described. The described substrates typically include a filler. Exemplary fillers include wood, fiberglass, polymers or mixtures thereof. Substrates can be made using methods such as extrusion, the Hatschek method, or other methods known in the art. See, for example, US Pat. No. 2005/0208285 Al (corresponds to International Patent Application No. O 2005/071179 Al); Australian Patent Application No. 2005100347; International Patent Application No. WO 01/68547 Al; International Patent Application No. WO 98/45222 Al; U.S. Patent Application Ser. No. 2006/0288909 Al, and Australian Patent Application No. 198060655 A. Non-limiting examples of substrates include sheet products for walls, boards and the like, for uses including fencing, roofing, flooring, wallboard. , boards for showers, plates for twisted walls, plates for vertical walls, panels for ceiling, boards of garrison, replicas of shingle tables of shaped edge and replicas of stone or stucco. One or both of the main surfaces of the substrate may be profiled or embossed to look like fibrous or rough-sawed wood or other construction product, or festooned or cut resembling shingle boards. The uncoated substrate surface typically contains a plurality of pores with micron or submicron scale cross sectional dimensions. A variety of suitable cement fiber substrates are commercially available. For example, several preferred fiber cement wallboard products are available from James Hardie Products Inc. of Mission Viejo, CA including those sold as HARDIEHOME (TM) wallboard, HARDIPANEL (TM) vertical wallboard, HARDI PLANK (TM) curved wallplates, HARDIESOFFIT (TM) panels , planks HARDITRIM (TM) and HARDISHINGLE (TM) wall plates. These products are available with an extended warranty, and are said to resist moisture damage, requiring only low maintenance, that do not crack, spoil or delaminate, that resist damage to prolonged exposure to moisture, rain, snow , salt, air and termites, which are non-combustible, and which offer the warmth of the wood and the durability of the cement fiber. Other suitable fiberboard wallboard substrates include AQUAPANEL (TM) cement board products from Knauf USG Systems GmbH & Co. KG of Iserlohn, Germany, cement board products CEMPLANK (TM), CEMPANEL (TM) and CEMTRIM (TM) of Cemplank of Mission Viejo, CA; WEATHERBOARDS (TM) cement board products from CertainTeed Corporation of Valley Forge, PA; MAXITOJE (TM), MAXISHAKE (TM) and MAXISLATE (TM) cement board products from MaxiTile Inc. of Carson, CA; cement board products BRESTONE (TM), CINDERSTONE (TM), LEDGESTONE (TM), NEWPORT BRICK (TM), SIERRA PREMIUM (TM) and VINTAGE BRICK (TM) from Nichiha U.S. A., Inc. of Norcross, GA; Cement board products EVERNICE (TM) of Zhangjiagang Evernice Building Materials Co., Ltd. of China and E BOARD (TM) cement board products from Everest Industries Ltd. of India. A variety of olefinic compounds can be used in the coating systems described. The olefinic compounds are different from the PVC dispersion resins, and are carbon containing compounds with at least one unsaturation site that can react, optionally in the presence of an initiator, to provide polymeric or crosslinked products. Non-limiting examples of olefinic compounds include monomers such as (meth) acrylates, vinyls, vinyl ethers, allylic ethers, vinyl esters, unsaturated oils (including mono, di and triglycerides), unsaturated fatty oils, and the like or mixtures thereof. The olefinic compounds also include oligomers or polymers having at least one unsaturation site that can react, optionally in the presence of an initiator, to provide the polymeric or crosslinked products. Exemplary olefinic monomers include esters of (meth) acrylate of unsubstituted or substituted C 1 -C 5 alcohols such as tripropylene glycol, isobornyl alcohol, isodecyl alcohol, phenoxyethyl alcohol, trishydroxyethyl isocyanurate, trimethylolpropane ethoxylate (TMPTA), ditrimethylolpropane ethoxylate (diTMPTA), hexanediol, neopentyl ethoxylated glycol, propoxylated neopentyl glycol, ethoxylated phenol, polyethylene glycol, bisphenol A ethoxylate, trimethylpropane, propoxylated glycerol, pentaerythritol, tetrahydrofurfuryl alcohol, beta-carboxyethyl alcohol, or combinations thereof. For example, the olefinic monomer can be isobornyl (meth) acrylate, isodecyl (meth) acrylate, phenoxyethyl (meth) acrylate, trimethylpropane tri (meth) acrylate, alkoxylated cyclohexanedimethanol di (meth) acrylate, tri (meth) acrylate. ) trimethylpropane ethoxylate acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, pentaerythritol tri (meth) acrylate, tetra (meth) ) pentaerythritol acrylate, di- (trimethylpropane-tetra (meth) acrylate), propoxylated glycerol tri (meth) acrylate, beta-carboxyethyl (meth) acrylate, bisphenol A ethoxylate di (meth) acrylate, di (meth) ethoxylated neopentyl acrylate, propoxylated neopentyl glycol di (meth) acrylate, trimetiolopropane di- (tetra (meth) acrylate) or combinations thereof. Preferred olefinic monomers include trimethylolpropane tri (meth) acrylate, bisphenol A ethoxylate di (meth) acrylate, propoxylated glycerol tri (meth) acrylate, trimethylolpropane ethoxylate tri (meth) acrylate, di- (tetra (met)) trimethylolropane acrylate), or combinations thereof. The monomer olefinic may contain a (C1-C15) alcohol radical such as hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxybutyl, 4-hydroxybutyl, 1-hydroxypentyl, 5-hydroxypentyl , 1-hydroxyhexyl, 6-hydroxyhexyl, 1,6-dihydroxyhexyl, 1, -dihydroxybutyl, and the like. Exemplary allyl ether monomers contain one or more allyl ether groups that typically bind to a core structure group that can be based on a wide variety of polyhydric alcohols. Non-limiting examples of suitable polyhydric alcohols include neopentyl glycol, trimethylol propane, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, trimethylene glycol, triethylene glycol, trimethylolethane, pentaerythritol, glycerol, diglycerol, 1-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol. , and any of the other polyols mentioned above in relation to the (meth) acrylate esters. Other exemplary allyl ether monomers include hydroxyethyl allyl ether, hydroxypropyl allyl ether, trimethylolpropane monoallyl ether, trimethylolpropane diallyl ether, trimethylolethane monoallyl ether, trimethylolethane diallyl ether, glycerol monoallyl ether, glycerol diallyl ether, pentaerythritol monoallyl ether , diallyl ether of pentaerythritol, triallyl ether of pentaerythritol, ether 1, 2, 6-monoallyl hexanetriol, 1, 2, 6-hexanetriol diallyl ether, and the like. Preferred allyl ethers include polypropoxylated and ethoxylated forms of allylic ethers. Exemplary vinyl ether monomers contain one or more vinyl ether groups and include an ether-hydroxybutyl vinyl ester, 1,4-cyclohexanedimethanol monovinyl ether, 1,4-cyclohexanedimethanol divinyl ether, monovinyl ether of ethylene glycol, divinyl ether of ethylene glycol, monovinyl ether of diethylene glycol, divinyl ether of diethylene glycol, divinyl ether of triethylene glycol, and the like. Preferred vinyl ether monomers include propoxylated or ethoxylated forms of vinyl ether monomers. The olefinic compounds can include latex polymers or polyurethane dispersions having olefinic groups attached. These compounds can be prepared as described in the PCT Application also pending applicants Serial No. (Proxy Control No. 160-P-1790 O01) filed on the same date and entitled COATING SYSTEM FOR ARTICLES OF CEMENT COMPOSITIONS .

A subset of the aforementioned olefinic compounds (eg, di (meta) hexanediol crilate, trimethylolpropane tri (meta) crilate and di-trimethylolpropane tetra (meta) crilate have multiple reactive groups ( example, two or more). These monomers or oligomers can function as crosslinking agents. The coating systems described or the coating compositions preferably contain from about 20 to about 95% by weight of olefinic compounds based on the total weight of the non-volatile components in the coating system, preferably from about 30 to about 90% by weight. weight and more preferably from about 50 to about 80% by weight. A variety of PVC dispersion resins can be used in the coating systems and methods described. A PVC dispersion resin typically contains resin particles (or a mixture of particles of various resins or mixed resins) in a liquid plasticizer. The PVC dispersion resin may include, for example, a PVC homopolymer, a copolymer or a combination thereof, and various additives. PVC dispersion resins can be made by emulsion polymerization, micro-suspension polymerization or by a process involving both techniques. PVC dispersion resins typically have very fine particles (eg, an average particle diameter of about 0.1 μp to about 1.5 μm). Typically, PVC dispersion resin particles show little or no porosity and has a very high surface area. When plasticizer is added to a dispersion resin (for example about 40 phr or more, a liquid suspension is obtained which can be called plastisol or organosol.) Copolymers of vinyl chloride and other monomers such as acetates and acrylates can be used to produce resins The PVC dispersion resins are typically produced by suspension polymerization and have an average particle size range of about 25 μp to 75 μp. The example commercially available PVC dispersion resins include GEON (TM) resins. ) (eg, GEON 137, 171, and 172) from PolyOne Corporation, Avon Lake, OH and NORVINYL (T) resins (eg, NORVINYL S6261, S6571, S7060 and S8060) from Hydro Polymers, Oslo, Norway. of coating or coating compositions described preferably contain from about 5 to about 80% by weight of PVC dispersion resin based on weight total of the non-volatile components in the coating system, more preferably from about 10 to about 70% by weight and more preferably from about 20% to about 50% by weight. The described coating systems may include one or more optional silicates (eg, a salt of silicate). Exemplary silicates include lithium silicate, potassium silicate, sodium silicate, ammonium silicate and the like. The amount of silicate can be for example from about 20 to about 50% by weight, from about 5 to about 40% by weight or from about 10 to about 35% by weight, based on the total weight of the non-volatile components. Silicates are available through a variety of chemical suppliers, for example potassium silicate is available from PQ Corporation, Valley Forge, PA. Wet adhesion tests and "freeze-thaw" cycles have shown, under laboratory conditions, that they stimulate long-term simulated exterior exposure found in northern climates. A Wet Adhesion test can be carried out in the following manner to evaluate the adhesion of the coating system after a substrate of coated cement fiber board has been saturated with water. According to this procedure, the coated substrates (eg, cement fiber boards) are soaked in water at room temperature for 24 hours. After soaking, the boards are removed from the water and kept at room temperature for 24 hours. A 3M HD 250 tape of 15.24 cm (6 inches) in length is applied to the surface of the board with the long axis of the tape in the direction of any Embossed pattern that may be present. The tape is pressed firmly on the board to ensure full contact. The tape is removed after pulling quickly at an angle of 9 degrees from the board. The "wet adhesion" performance is rated based on the percent of the coating removed from the cement board. Performance is also evaluated by noting where a fault occurs. For example, failure can occur between the interfacial coating layers, between the coating and the board surface, or within the board itself. Preferred coating systems or coating compositions typically have less than 25% coating removal, more preferably less than 15% coating removal. In addition, the failure is preferably within the board as indicated by a significant amount of board fiber that adheres to the removed coating. Preferred coated articles can withstand at least 30 freeze-thaw cycles, when tested in accordance with Test Method A of ASTM D6944-03. As it is said, this ASTM test method mentions a sequence of 30 cycles. However, instead of simply graduating a specimen as "approved" at the end of the 30 cycles, the test is desirably lengthened to include additional cycles. More preferably, the coated articles can withstand at least 75 freeze-thaw cycles, more preferably at least 125 freeze-thaw cycles and optimally at least 175 freeze-thaw cycles. The coating systems described or the coating compositions preferably have an improved volatile organic content (VOC), that is, lower. Coating systems or coating compositions desirably have a VOC of less than about 5% based on the total weight of the coating system, preferably a VOC of less than about 2%, more preferably a VOC of less than about 0.5%. The olefinic compounds are curable by radiation, for example, visible light, ultraviolet light, has of electrons, microwaves, gamma radiation, infrared radiation and the like. An initiator system is not required for electron beam curing but for other sources of radiation it will typically be chosen based on the particular type of healing energy (eg, UV, visible light or other energy) and cationic healing mechanism, of free radicals, cationic or other. Therefore, in a preferred embodiment, the coating system is curable by electron beams and does not require an initiator. In another preferred embodiment, the coating system is UV curable and polymerizable by free radicals, and includes a UV photoinitiator system that generates free radicals in response to UV light and therefore cures the coating. Non-limiting examples of initiators include peroxide compounds, azo compounds, cationic generating initiators, cleavage-type initiators, abstraction-type initiators, and the like. Exemplary peroxide compounds include t-butyl perbenzoate, t-amyl perbenzoate, eumenohydroperoxide, t-amyl peroctoate, methyl ethyl ketone peroxide, benzoyl peroxide, cyclohexanone peroxide, 2,4-pentanedione peroxide. , di-t-butyl peroxide, t-butyl hydroperoxide, and di- (2-ethylhexyl) peroxydicarbonate. Preferably, the curing agent is t-butyl perbenzoate, methyl ethyl ketone peroxide, or eumeno hydroperoxide. The methyl ethyl ketone peroxide is conveniently employed as a solution of dimethyl phthalate, for example LUPERSOL (TM) DDM-9 by Ato-Chem. Exemplary azo compounds include 2,2-azo bis- (2,4-dimethylpentane-nitrile), 2,2-azo bis- (2-methylbutanonitrile) and 2,2-azobis- (2-methylpropanenitrile). Exemplary cationic gene photoinitiators include super acid-generating photoinitiators such as triaryliodonium salts, triarylsulfonium salts, and the like. A preferred triarylsulfonium salt is triphenyl sulfonium hexafluorophosphate.

Exemplary cleavage-type photoinitiators include alpha, alpha-diethoxyacetophenone (DEAP); dimethoxyphenylacetophenone (IRGACURE (TM) 651); hydroxycyclohexylphenylketone (IRGACURE (TM) 184); 2-hydroxy-2-methyl-1-phenylpropan-1-one (DAROCUR (TM) 1173); a 25:75 mixture of bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentyl phosphine oxide and 2-hydroxy-2-methyl-1-phenylpropan-1-one (IRGACURE (TM) 1700), a 50:50 mixture of hydroxycyclohexylphenyl ketone and benzophenone (IRGACURE (TM) 500), a 50:50 mixture of 2,4,4, ß-trimethylbenzoyl-diphenyl-phosphine oxide and 2-hydroxy-2-methyl-1-phenyl -propan-1-one (DAROCUR (TM) 4265), acryl phosphine bis (IRGACURE (TM) 819) and phosphine oxide (IRGACURE (TM) 2100), all available from Ciba Corporation, Ardsley, NY Other excision-like primers include 2, 4, 6-trimethylbenzoyl-diphenylphosphine oxide (LUCIRIN (TM) TPO) from BASF Corporation and a 70:30 mixture of oligo 2-hydroxy-2-methyl- [4- (1-methyl vinyl) phenyl] propan- l-one and 2-hydroxy-2-methyl-l-phenylpropan-l-one (KIP (TM) 100) available from Sartomer (Exton, Pa.) | Preferred cleavage-type photoinitiators are hydroxycyclohexylphenyl ketone, 2-hydroxy- 2-methyl-l-phenylpropan-l-one, benzophenone, 2,4,6-trimethylbenzoyl-diphenyl ether osphine bis acrylic phosphine and a 70:30 mixture of 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propan-l-one and 2-hydroxy-2-methyl-1-phenylpropan-1-one Non-limiting examples of photoinitiators type Hydrogen abstraction includes benzophenone, substituted benzophenones (eg, ESCACURE (TM) TZT from Fratelli-Lamberti) and other diaryl ketones such as xanthones, thioxanthones, Michler's ketone, benzyl, quinones and substituted derivatives of all the above. Camphorquinone is an example of a compound that can be used when it is desired to cure a coating system with visible light. For compositions or coating systems having an olefinic compound that includes a mixture of two or more of a functional group of (meth) acrylate, an allylic ether and a vinyl ether, a combination of curing processes can be used. For example, a coating composition having a (meth) acrylate and vinyl ether functional group may typically include an alpha cleaving or hydrogen abstraction type photoinitiator for polymerization of the (meth) acrylate groups and a cationic generating photoinitiator for polymerization of the vinyl ether groups. If desired, the composition of the coating system may also include a co-initiator or synergistic photoinitiator. Non-limiting examples of co-initiators include (1) tertiary aliphatic amines such as methyl diethanol amine and triethanol amine; (2) aromatic amines such as amylparadimethylaminobenzoate, 2-n-butoxyethylbenzoate, 4- (dimethylamino), 2- (dimethylamino) ethyl benzoate, ethyl-4- (dimethylamino) benzoate and 2-ethylhexyl-4- (dimethylamino) benzoate; (3) (meth) acrylated amines such as EBECR YL (T) 7100 and UVECR YL (TM) P 104 and Pl 15, all from UCB RadCure Specialties; and (4) mixtures of amino-functional acrylate resins or oligomers or methacrylate such as EBECR YL (TM) 3600 or EBECRYL (TM) 3703, both from UCB RadCure Specialties. Combinations of the four preceding categories of coinitiators can also be used. In the case of UV radiation curing systems, the preferred amount of photoinitiator present in the coating systems described may be from about 0.02 to about 15% by weight of the non-volatile components. More preferably the photoinitiator can be from about 0.5 to about 10% by weight, and more preferably the photoinitiator can be from about 0.75 to about 5% by weight of the non-volatile components. Other methods may be used to cure the coating systems in combination with methods described herein. Those other curing methods include thermal curing, chemical curing, anaerobic curing, wet curing, oxidative curing, and the like. The methods may require the inclusion of a corresponding healing initiator or curing agent in the composition. For example, curing can be introduced by means of peroxide, metal curing packages can induce an oxidative cure, or multifunctional amines (eg isophorone diamine) can effect a curing of chemical crosslinking through the addition of Michael of amine groups on the groups unsaturated reactive acrylate. If these additional initiators are present in the coating system typically they can constitute approximately 0.1-12% by weight of the curable coating system. The means for carrying out the methods are known to those skilled in the art or can be determined using standard methods. Other optional components for use in the coating systems of the present are described in Koleske et al., Paint and Coatings Industry, April, 2003, pages 12-86. Typical performance enhancing additives that may be employed include surface active agents, pigments, dyes, inks, surfactants, dispersants, defoamers, thickeners, thermal stabilizers, leveling agents, coagulants, biocides, molds, anti-cratering agents, indicators of curing, plasticizers, fillers, settling inhibitors, ultraviolet light absorbers, optical brighteners, and the like to modify properties. Coating systems may also contain a coalescent or many optional coalescents known in the art. The optional coalescent is preferably a VOC coalescent as described in U.S. Pat. No. 6,762,230. Exemplary coating systems that can be used in coating systems are listed below. This is not intended to be an exhaustive list of examples of coating systems. Examples include the following compositions: A One or more olefinic compounds (e.g., monomers, oligomers, or polymers) and one or more PVC dispersion resins; and B One or more olefinic compounds (e.g., monomers, oligomers, or polymers) and one or more PVC dispersion resins and an initiator. Composition A - An example of a coating system suitable for use in the invention includes a mixture of (i) olefinic monomers or oligomers, (eg, trimethylolpropane triacrylate (TPTA)) (available from Sartomer) and (ii) a PVC dispersion (eg, GEON 137, 171 or 172 of PolyOne Corporation or NORVIVNYL S6261, S6571, S7060 or S8060 of Hydro Polymers) Composition B - An example of a coating system suitable for use in the invention includes a mixture of (i) olefinic monomers or oligomers (e.g., trimethylolpropane triacrylate (TMTPTA) (available from Sartomer); (ii) a PVC dispersion (eg, GEON 137, 171 or 172 from PolyOne Corporation or NORVIVNYL S6261, S6571, S7060 or S8060 from Hydro Polymers); and (iii) an initiator (e.g., DAROCURE 1173 (D-1173)). The present method includes applications of suitable coating systems that can be applied as a single layer or as multiple applications of at least one coating composition. The specific application and the order of application of the coating compositions can be easily determined by a person skilled in the art of preparing or applying such compositions. The example descriptions of these coating systems are provided below. The specific routes for the preparation of coated articles include: - Applying a coating system, and subjecting the coating system to radiation curing (e.g., electron beam or UV curing); and - Applying a coating composition, applying one or more additional coating compositions, and subjecting the resulting coating system to radiation curing (e.g., electron beam or UV curing). Consequently, the described articles can be prepared by applying the coating system as a Single layer or coating system can be applied as multiple layers. Coating compositions applied using multiple coating layers can allow mixing of the coating layers on one surface. In any of the above application routes when there is a carrier (e.g., water or solvent) present in one or more of the compositions, the coated article may be subjected to rapid drying to remove at least a portion of any carrier that may be I presented. The coating compositions are preferably applied at about 75 to 100% solids by weight and preferably at about 85% to 100% solids. The coating systems may be applied by any number of application techniques including but not limited to brushing (e.g., using a brush coater), direct roll coating, roll reverse coating, flood coating, dip coating, coating vacuum, curtain coating and sprinkling. Each of the various techniques offers a unique set of advantages and disadvantages depending on the profile of the substrate, the morphology and the tolerable application efficiencies. The described coating systems can be advantageously applied, for example, to a cement fiberboard substrate by coating with roller or spray. Low viscosities facilitate uniform film control. The thickness of the applied film can be controlled by varying the speed of application. A dry film thickness (DFT) of the coating system on the cement fiberboard substrate can for example be in the range of, but not limited to, about 0.005 to about 0.1 mm (about 0.2). to about 4 mils), more preferably from about 0.008 to about 0.08 mm (about 0.3 to about 3 mils). It is preferred that the coated articles be coated on at least one major surface with the coating system. More preferably, the coated articles are coated on a major surface and up to four minor surfaces including any edge. More preferably, coated articles are coated on all major surfaces (e.g., both), and up to four minor surfaces including any edges. Multiple layers of the described coating systems can be applied. A primer (eg, a latex primer) or topcoat (eg, a topcoat that contains latex) may be applied or both a primer and a top coat directly to the coating system. If desired, this can be done at the site where the fiber cement board substrate is manufactured. The coating systems and compositions herein may be used in place of or in addition to coatings that the prior art has categorized as "sealants," "primers," and "top coatings." However, the systems and compositions may not agree precisely in any category by itself and the terms should not be limited. It is also indicated that the described coating systems and coating compositions can be used with other coating compositions such as those described in the following applications, US Pat. Nos. Series 60 / 764,103, 60 / 764,044 and 60 / 674,131, each filed on January 31, 2006, and 60/802, 185, filed on May 19, 2006. All patents, patent applications, and Literature cited in the specification are hereby incorporated by reference in their entirety. In the case of any inconsistency, the present description will prevail, including any definition in it. The invention has been described with reference to various specific and preferred embodiments and techniques. However, it must be understood that any variation and modification may be made while remaining within the spirit and scope of the invention. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (18)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A coated article, comprising: a substrate of fiber cement board; and a radiation curable coating system applied to the substrate, characterized in that the coating system comprises: one or more olefinic compounds; and one or more polyvinyl chloride dispersion resins. The article according to claim 1, characterized in that the coating system includes two or more coating compositions that can be applied in two or more layers. 3. The article according to any preceding claim, characterized in that the coating system additionally comprises an initiator system. 4. The article according to claim 3, characterized in that the coating system comprises an ultraviolet light photoinitiator. 5. The article according to any preceding claim, characterized in that the system of The coating comprises a first composition comprising an olefinic compound and a second composition comprising a polyvinyl chloride dispersion resin. 6. The article according to any preceding claim, characterized in that the coating system comprises a composition comprising both an olefinic compound and a polyvinyl chloride dispersion resin. The article according to any preceding claim, characterized in that the olefinic compound comprises a (meth) acrylate, vinyl, vinyl ether, allylic ether, vinyl ester, unsaturated oil, unsaturated fatty acid, or a combination thereof. 8. The article according to any preceding claim, characterized in that the olefinic compound comprises trimethylolpropane tri (meth) acrylate, ethoxylated di (meth) acrylate of bisphenol A, propoxylated glycerol tri (meth) acrylate, tri (meth) acrylate of trimethylolpropane ethoxylate, di- (tetra (meth) acrylate trimethyolpropane), or a combination thereof. 9. The article according to any preceding claim, characterized in that the olefinic compound comprises a monomer. 10. The article according to any preceding claim, characterized in that the compound Olefinic comprises an oligomer. The article according to any preceding claim, characterized in that the polyvinyl chloride dispersion resin comprises resin particles in a liquid plasticizer, and wherein the particles have an average particle diameter of about 0.1 microns to about 1.5 microns. The article according to any preceding claim, characterized in that a primer containing latex or an upper covering containing latex is applied on the coating system, and wherein the cement fiberboard substrate is in the form of a product. of iron for wall. 13. The article according to any preceding claim, characterized in that the coated article when cured by radiation can withstand at least 30 freeze-thaw cycles. 14. The article according to claim 13, characterized in that the coated article can withstand at least 175 freeze-thaw cycles. 15. The article according to any preceding claim, characterized in that the coating system has a content of volatile organic compounds of less than about 5% based on the total weight of the coating system. 16. The article according to claim 15, characterized in that the coating system has a content of volatile organic compounds of less than about 0.5% based on the total weight of the coating system. 17. A method for making a coated article, characterized in that it comprises: providing a substrate of fiber cement board; coating at least a portion of the substrate with a radiation curable coating system comprising one or more olefinic compounds, and one or more polyvinyl chloride dispersion resins; and radiation cure the coating. 18. The method according to claim 17, characterized in that it comprises coating the substrate with a first coating composition comprising the olefinic compound or more olefinic compounds followed by a second coating composition comprising one or more chloride dispersion resins of polyvinyl.