MXPA97008947A - Recubrimie substrates - Google Patents

Abstract

The present invention relates to: In a method for coating a substrate, preferably a cellulosic substrate, an aqueous coating composition comprising a polymer having carbonyl functional portions, can be coated, in tandem, directly on or under a coating Cured by UV radiation. The method provides a system with low content of volatile organic substances (VOC), which offers good adhesion between the two coatings.

Description

SUBSTRATES OF COVERING This invention relates to a method for coating, in tandem, substrates with heat-stable, highly entangled coatings, or with water-based coatings. In particular, although not exclusively, the invention relates to a method for coating, in tandem, cellulosic substrates with both UV-curable coatings, with high solids content, as with water-borne paints. Cellulosic substrates, particularly composite cellulosic substrates, such as MDF, hardboard and particle board, are widely used in the manufacture of interior furniture and other board applications. Often, to prevent the penetration of water into the substrate, which would otherwise cause damage to the substrate due to the swelling of the fibers by hydration, the substrate is coated with a UV-curable coating with high solids content. and with low content of volatile organic substances (VOC), which, once cured, seal the substrate and provide an effective barrier against water ingress. Unfortunately, UV-curable coatings with high solids content tend to be more suitable for clear, rather than pigmented, applications. Therefore, when required for decorative purposes, substrates sealed with clear coatings cured by UV will normally be subsequently painted with a pigmented topcoat, based on organic solvents. With the increasing pressure of environmental and governmental regulations, there is a strong desire to reduce or eliminate organic substances in paints. However, currently, in many coating markets, paints containing organic solvents still dominate, because water-based alternative paints, with low VOC, fail to meet the performance criteria required for them. In particular, in the case of cellulosic substrates, although the combination of UV curable sealant, with high solids content, in conjunction with pigmented waterborne top coatings, seems to offer a route for low energy, low VOC coatings with attractive economy, due to the severe adhesion problems traditionally found between the upper coatings that carry water and the highly interlaced lower coatings, and the successful performance of this system has not been carried out. A number of prior art documents disclose waterborne compositions for coating various substrates. For example: JP-A-7102218 (Nippon Carbide Industries KK) discloses an aqueous coating composition, comprising a core / shell polymer, having actacetyl groups in the shell polymer, hydrazine derivatives with residual hydrazine groups and / or amines with two or more amine groups, and pigments. The composition described is suitable for coating many substrates, including metal substrates, plastic substrates, wood, leather and inorganic substrates, such as concrete or mortar, and on old films such as on vinyl chloride, alkyd resins and other previous painting movies. The plastic substrates disclosed are ABS sheets, polystyrene sheets and steel sheets covered with vinyl chloride, these plastics are generally known to be thermoplastic materials. DE-A-4344391 (Rohm GmbH) discloses aqueous dispersions of film-forming polymers, based on polymethyl (meth) acrylate esters, for coating surfaces of thermoplastic parts. The film forming polyester can be polymerized from a monomer system comprising up to 15% of crosslinkable onomers with an acetoacetyl group, such as acetoacetoxyethyl methacrylate (AAEM). US-A-5213901 and US-A-5227423 (Rohm and Haas Company) disclose an aqueous binder composition comprising a copolymer formed from a monomer system including from 10 to 35% by weight of an adhesion promoting monomer in damp, selected from the group consisting of monomers containing ethylene oxide, cyanoacetoxy and acetoacetoxy, and hydroxymethyldiacetone acrylamide. The binder is disclosed for use as a paint. US-A-5278225 (Wacker-Chemie GmbH) discloses aqueous dispersions of copolymers comprising acetoacetoxy functional groups and inooxy crosslinking agents, useful as binders to produce coatings, coatings and impregnations in the field of coatings. It is disclosed that the dispersions are particularly suitable as adhesives for bonding to polyolefin surfaces previously treated by corona and flame. EP-A-0697417 (Rohm and Haas Company) discloses a latex binder to produce a high gloss coating on a substrate to the environment, this substrate can be chalk, wood or cement. The binder is said to comprise a latex polymer that carries a functional acid part and a functional enamine side, which results from the reaction of the functional side of acetoacetyl on the latex polymer, with ammonia or amine. While the prior art documents generally teach the use of aqueous coatings on various substrates, none of these documents discloses or suggests that aqueous coatings can be successfully applied to highly entangled polymeric surfaces, such as those found when a substrate is coated with an adhesive. thermostable material and thus replace the coatings that carry solvents, which are commonly used for this very specific application. Where reference is made to the coating of polymeric surfaces in the prior art documents, these polymeric surfaces have been thermoplastic materials, these materials are generally understood to be not highly interlaced materials. It is an object of the present invention to provide a low VOC system for coating, in tandem, substrates with both highly entangled coatings and water based coatings. According to the present invention, there is provided a method comprising coating, in tandem, a substrate with (i) a highly interlaced coating, formed of a UV curable composition, and (ii) a cured coating, formed of an aqueous composition comprising a polymer having, as polymerized units, from 0.1 to 100%, preferably from 1 to 50% and even more preferably from 5 to 20% by weight of the polymer of at least one monomer capable of producing carbonyl functional parts in the polymer.

The substrate can be first coated with a highly interlaced coating (i), followed by the cured coating (ii), or the substrate can be first coated with the cured coating (ii), followed by the highly entangled coating (i) . The method of the present invention provides a low VOC system for coating, in tandem, substrates with both a highly interlaced coating and a water-based coating. The highly interlaced coating (i) is preferably formed of a thermosetting material. This material can be a UV curable composition, which, before curing, can be a high solids composition or a water borne composition comprising suitable components curable by UV radiation. UV curable coatings can generally be divided into two main categories: 1) free radical polymerized (meth) acrylate functionalized polymers and 2) cationically polymerized epoxides. Functionalized polymers of methacrylate and acrylate generally comprise oligomers and functional monomers of (meth) acrylate, combined with a photoinitiator to facilitate curing by UV radiation. These (meth) acrylate functional oligomers are typically prepared by a) the reaction of difunctional epoxides with methacrylic or acrylic acid, b) the condensation product of difunctional isocyanates with functional (meth) acrylates of hydroxy, or c) the condensation product of (meth) acrylic acid and hydroxyl groups in a polyester backbone, or a hydroxy acrylate with residual acid groups in the backbone of the polyester. Cationic systems are based on cycloaliphatic epoxides and a photoinitiator, which decompose to give a "super" acid with UV radiation. The super acid catalyses the cationic polymerization of the epoxy (See Radiation Curing In Polymer Science And Technology, Vol. 1: Funada entos in Methods, Edited by JP Fouassier and JE Rabek, published by Elsevier Applied Science (1993). UV radiation, after exposure to the UV radiation process, produces highly entangled coatings, which have traditionally proven to be difficult to adhere to on top water-based coatings, without the use of an intermediate coating.Preferably, the coating (i) is cured in the presence of oxygen, more preferably in the presence of air.The cured coating (ii) is formed of an aqueous composition comprising a functional carbonyl polymer, which preferably includes polymerized units of one or more monomers selected from the group consisting of monomers containing ethylene oxide, monomers containing cyanoacetoxy, monomers containing they contain acetoacetoxy, acro-lein, methacrolein, vinyl-alkyl (-020) -ketones and amides containing keto, such as diacetone-acrylamide. Monomers containing ethyleneureide, cyanoacetoxy-containing monomers and acetoacetoxy-containing monomers are described in detail in US-A-5213901 in column 3, line 48, to column 4, line 38. In a particularly preferred embodiment, the The aqueous composition comprises a polymer that includes from 0.1 to 100%, more preferably from 1 to 50% and especially preferred from 5 to 20% by weight of polymerized units, of one or more functional acetoacetyl monomers, having the structure: A - (- C - C - C -) B H in which: R? is H, an alkyl with 1 to 10 carbon atoms, or phenyl; A is any of: R2 R3 0 \ IC = C - (- R4-) a - (- X -) n - (- C - Y-) m - (- R5-) q / H R2 R- O II C "(- * 4 -) a "i" x ") n" (- C - Y -) - (- R5-) a - O H wherein: R2 is H, alkyl having 1 to 10 carbon atoms, or phenyl, substituted phenyl, halogen, CO2CH3 or CN; R3 is H, alkyl having 1 to 10 carbon atoms, or phenyl, substituted phenyl or halogen; R 4 is alkylene or substituted alkylene, having 1 to 10 carbon atoms, or substituted phenylene or phenylene; R5 is alkylene or substituted alkylene, having 1 to 10 carbon atoms; a, m, n and q are, independently, any of 0 or 1; X and Y are, independently, either of -NH- or -0-; B is A, alkyl having 1 to 10 carbon atoms, or phenyl, substituted phenyl or a group or heterocyclic, preferably (C4 to CIO). Particularly preferred monomers are acetoacetoxyethyl methacrylate (AAEM), acetoacetoxyethyl acrylate (AAEA), acetoacetoxypropyl methacrylate, allyl acetoacetate, acetoacetoxybutyl methacrylate, 2,3-di (acetoacetoxy) propyl methacrylate, vinyl acetoacetate, or combinations thereof . Optionally, the polymer used in the coating (ii) is a copolymer comprising carbonyl functionality, wherein this copolymer includes, as polymerized units, from 0 to 99.9%, preferably from 50 to 99%, more preferably from 80 to 95% by weight of one or more copolymerizable monomers. Preferably, the copolymerizable monomers are selected from the group consisting of unsaturated and unsubstituted, saturated and momonetilinically unsaturated carboxylic acid ester monomers, such as methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylate Butyl, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, oleyl (meth) acrylate, (meth) acrylate, (meth) acrylate of stearyl, methyl itaconate, methyl fumarate, butyl fumarate, glycidyl methacrylate, dicyclopentadienyl (meth) acrylate, isocyanatoethyl methacrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, (meth) acrylate of N, N'-dimethylamino and vinyl acetate; monomers of substituted and unsubstituted carboxylic acids and their anhydrides, such as (meth) acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid and maleic anhydride; monomers of substituted and unsubstituted (meth) acrylamides; styrene and substituted styrene monomers; other substituted and unsubstituted vinyl monomers, such as vinyl chloride, vinylidene chloride and N-vinylpyrrolidone; other substituted and unsubstituted alkylene monomers, such as ethylene, propylene, butylene and isopropylene; and acrylonitrile and methacrylonitrile. If desired, the polymer used in the coating (ii) may also comprise, as polymerized units, from 0.1 to 25% by weight of polyfunctional, substituted and unsubstituted, ethylenically unsaturated monomers, such as allyl methacrylate, diallyl phthalate, butylene glycol di (meth) acrylate, 1,6-hexane-diol diacrylate and divinylbenzene. These monomers tend to induce entanglement or premature gel formation of the copolymer. The polymer used in the coating (ii) is preferably a thermoplastic or substantially entangled copolymer, when applied (in an uncured state) to the substrate. The polymer used in the coating (ii) may comprise a functional acid part pending to supply the polymer with an acid number of from 1 to 325, preferably from 3 to 130. The desired acid number is achieved by controlling the amount of the functional monomer acid used in the polymer, by a known method.

The polymer used in coating (ii) preferably has a glass transition temperature, Tg, of -40 to + 1202C, as measured by differential scanning calorimetry. The Tg is supplied as the mid-point of inflection using the half-height method. A polymer having a Tg of 0 to 902C is the preferred raster. The polymer preferably has a weight average molecular weight per GPC of 500 to 5,000,000. This weight average molecular weight per GPC can be adjusted through the appropriate use of methods known in the art, such as by the use of chain transfer agents. The weight average molecular weight by "GPC" is this average molecular weight, as determined by gel permeation chromatography, as described on page 4 of The Characterization of Polymers, published by Rohm and Haas Company in 1976, which uses Polymethyl methacrylate as the standard. The average particle size, measured as the diameter of the polymer particles, suitable for use in the coating (ii) is preferably 20 to 1000 nm, more preferably 30 to 500 nm. The aqueous composition in the coating (ii) may comprise at least two mutually incompatible copolymers, at least one of which is a polymer having the carbonyl functional parts described above. These mutually incompatible copolymers can be present in the following morphological configurations, for example, core / shell particles, with complete shell phases surrounding a single core, core / shell particles with shell phases that incompletely encapsulate the core, particles of core / shell with a multiplicity of cores, interpenetrating network particles and multilobal particles, described in commonly assigned US-A-4791151. In all these cases, the majority of the surface area of the particles will be occupied by at least one external phase 'and the interior of the particles will be occupied by at least one internal sewer. The mutual incompatibility of the two polymer compositions can be determined in various ways known in the art. The use of scanning electron microscopy, which uses dyeing techniques to make the difference between the appearance of the phases, for example, is one such technique. In a further embodiment of the invention, the polymer used in the coating (ii) can be mixed with other polymers, such as those normally found in paints and other coatings. For example, the copolymer (ii) can be mixed with a polyurethane, a polyester, a polyamide, an acrylic copolymer, a styrene-acrylic copolymer or another polymer, or mixtures of two or more of these polymers.

Polymerization techniques that can be used to prepare the polymer are well known in the art. The polymer can be prepared by the aqueous polymerization in solution or emulsion, with the emulsion polymerization being preferred. The polymerization can be a redox or thermal initiation process, which employs conventional free radical initiators, such as, for example, ammonium and alkyl sulfates, hydrogen peroxide, benzoyl peroxide or t-butyl peroctoate, at typically from 0.05 to 3% by weight, based on the total weight of the monomer. Redox systems using the same initiators coupled with suitable reducing agents, such as, for example, isoascorbic acid, sodium bisulfite or sodium sulfoxylate-formaldehyde, can be used at similar levels. The polymer preferably comprises from 1 to 100% of the total solids in the coating (ii). Typically, the coating (ii) will preferably comprise 80 to 30% water. The coating (ii) may comprise additional ingredients, such as thickeners, surfactants, pigments, leveling aids, waxes, slip aids, coalescents and / or plasticizers, these materials being typical ingredients of waterborne paints and coatings. The coating may also include a subsequent entanglement agent, such as polyaziridine, polyisocyanate, polycarbodiimide, polyepoxide, polyaminoplast, polyalkoxysilane, polyoxazolidine, polyamine and polyvalent metal compounds, to improve the cure time of the water-based coating, once that has been applied to the substrate. Preferably, the substrate is a cellulosic material, such as wood or paper or a composite material thereof, such as MDF, hardboard, particleboard or cardboard. In a particularly preferred embodiment, the cellulosic material is selected from the group consisting of wood, MDF, hardboard and particle board. These materials typically find application in the manufacture of interior furniture and home accessories. In this embodiment, preferably the cellulosic substrate is first coated with a highly interlaced coating (i), which can act as a sealant or subcoat, to prevent the ingress of water into the substrate fibers, and then the substrate, with a highly interlaced coating, is subsequently coated with the water-based coating (ii). The water-based coating can be a paint, which includes a pigment and other components traditionally found in these formulations, to give, once cured, the proper decorative effect to the substrate. In another embodiment, the cellulosic substrate is a paper material, such as is traditionally used in printing or packaging applications. Here, the water-based coating (ii) can first be applied to the substrate, for example in the form of an ink, and then the water-based cured coating (ii) and the substrate are both coated with the coating (ii) ) highly interlaced. The invention will now be described with reference to the following examples: Examples Several polymers in emulsion A were prepared up to I, as detailed in Table I, by the following procedure: Procedure for the Preparation of Polymer A A 5-liter, round bottom, 4-neck, round-bottomed reaction flask containing an initial charge of the copper of 850 g of deionized water (DI) and 35.5 g of Na sulfate (E0) 4 of lauryl (30%), was heated to 852C under a nitrogen sweep. At 85 ° C, an aliquot of a Monomer Emulsion (EM) comprising 750 g of DI water, 38.8 g of (E0) 4 sulfate) was charged to the reaction vessel.

Na-lauryl (30%), 538 g of butyl acrylate (BA), 697.9 g of methyl methacrylate (MMA), 145.4 g of acetoacetoxy-ethyl methacrylate (AAEM) and 72.7 g of methacrylic acid (MAA). The nitrogen sweep was discontinued. A catalyst solution consisting of 3.7 g of sodium persulfate (NaPS) was added at a batch temperature of 84se and the batch underwent an exothermic reaction at 88se. After the crest exothermic reaction, the batch was kept for an additional 5 minutes. Then a solution consisting of 3.6 g of sodium carbonate (Na2C03) dissolved in 55 g of DI water was charged to the batch. The remaining monomer emulsion, together with a co-charge consisting of 1.8 g of NaPS dissolved in 90 g of DI water, was then fed to the pan in 90 minutes. The reaction temperature was maintained at 85 ± 22C throughout the loading period. Upon completion of the monomer emulsion, the emulsion container was rinsed with 45 g of DI water, which was fed to the copper. When all the charges were completed, the batch was kept for 15 minutes at that temperature. Thirty (30) g of DI water were added to the batch before cooling. At 60-65 ° C, a redox initiator (0.05 parts of t-butyl hydroperoxide and 0.034 parts of isoascorbic acid / 100 parts) was added. A neutralization solution consisting of 67 g of 29% ammonia in 200 g of DI water was added. The viscosity was adjusted with 96 g of DI water.

Process for the Preparation of Polymers B through I The process described in Polymer A was used to prepare all additional examples. The exact charges of the monomers and the copper are described in Table I. The raw material used in Table I is defined as follows: BA Butyl acrylate MMA Methyl methacrylate AAEM Acetoacetoxy ethyl methacrylate DAAM Diacetone acrylamide MEEU Methacryloxyethylethyleneurea MAA Methacrylic acid n-DDM n-Dodecyl-mercaptan Agent Tensoactive A Nonoxynol-4-ammonium sulfate Sodium surfactant agent B Luret-sulphate TABLE TABLE I (Continued) TABLE I (Continued) Examples 1-13 Water-based coatings, comprising one or more of the above emulsion polymers, were prepared by adding the listed ingredients, while stirring, with a conventional laboratory mixer.

Example # 1 (Comparative): Example # 2 100 g of Polymer I 100 g of Polymer-A 2.85 g of diethylene glycol - 2.88 g of diethylene glycol monobutyl ether raonobutyl ether 8.55 g of ethylene glycol - 8.62 g of ethylene glycol monobutyl ether monobutyl ether 17.4 g of water 21.3 g of water Example # 3: Example # 4: 100 g of Polymer B 100 g of Polymer C 2.88 g of diethylene glycol - 2.88 g of diethylene glycol monobutyl ether - monobutyl ether 8.62 g of ethylene glycol - 8.62 g of ethylene glycol monobutyl ether monobutyl ether 24.2 g of water 18.8 g of water Example # 5: Example # 6: 100 g of Polymer D 100 g of Polymer E 2.88 g of diethylene glycol - 2.88 g of diethylene glycol monobutyl ether monobutyl ether 8.62 g of ethylene glycol - 8.62 g of ethylene glycol monobutyl ether monobutyl ether 22. 4 g of water 17.6 g of, water Example # 7: Example # 8: 100 g of Polymer F 100 g of Polymer G 2.55 g of diethylene glycol - 2.03 g of diethylene glycol monobutyl ether monobutyl ether 7.64 g of ethylene glycol - 6.07 g of ethylene glycol monobutyl ether monobutyl ether 16. 4 g of water 21.3 g of water 1.55 g of Acrysol ™ RM-8W Example # 9: Example # 10: 100 g of Polymer H 10 g of Example 1 2.55 g of diethylene glycol-10.2 g of Example 3 monobutyl ether 7.64 g of ethylene glycol monobutyl ether 10.1 g of water Example # 11: Example # 12 : 10 g of Example 1 25 g of Example 1 5.1 g of Example 3 8.8 g of Pigment Grind A Example # 13: Pigment Grind A: 25 g of Example 3 855.4 g of water 8.5 g of Pigment Grind A 140.4 g of Tamol® 731 23.8 g of Triton® CF-10 11.8 g of Tego® Foamer 800 2688 g of Ti-Pure ® R-700 Diethylene glycol monobutyl ether is supplied by Union Carbide, Chemicals and Plastics Company Inc., 39 Old Ridgebury Rd, Danbury CT 06817-0001; Ethylene glycol monobutyl ether is supplied by Union Carbide, Chemicals and Plastics Company Inc., 39 Old Ridgebury Rd, Danbury CT 06817-0001; The Acrysol® RM-8 is supplied by Rohm and Haas Company, Independence Mali West, Philadelphia PA 19105; Tamol® is supplied by Rohm and Haas Company, Independence Mali West, Philadelphia PA 19105; Triton® CF-10 is supplied by Union Carbide, Chemicals and Plastics Company Inc., 39 Old Ridgebury Rd, Danbury CT 06817-0001; Tego® Foamex 800 is supplied by Goldschmidt Chemical Corp., P. 0. Box 1299, 914 Randolph Rd., Hope ell, VA 23860; Ti-Pure® R-700 is supplied by Dupont Company, Chemicals and Pigments Division, Wilmington, DE 19898.

Substrate preparation Five different UV curable materials were used to coat the substrate and they are listed below along with the dispenser. A coiled wire rod # 12 was used to apply a wet film thickness of 37.5 μm (microns) on a hardboard substrate of the Masonite type. The first coating was allowed to dry for 10 minutes, then irradiated with 1 UV lamps @ 200 watts / 2.5 cm, using an AETEK UV processor, Van Dyke Rd Plainfield Illinois 60544. The UV line speed was 12 m per minute . The coating was then polished with grit sandpaper 240. A second coating was applied, as before, and allowed to dry for 10 minutes and then irradiated with 2 UV lamps @ 200 watts / 2.5 cm at a line speed of 12 m per minute. Coating # 1: CDG # UV-102, supplied by Coating Development Group, P. O. Box 14817, Philadelphia, PA 19134; Coating # 2: CDG # WM0010, supplied by Coating Development Group, P. 0. Box 14817, Philadelphia, PA 19134; Coating # 3: UV sealer / filler # 107R000, supplied by Forest Paint Company, 1011 McKinley Ave. Eugene Oregon 97402; Coating # 4: Magic Light Clear Sealer # 107R014, supplied by Forest Paint Company, 1011 McKinley Ave. Eugene Oregon 97402; Coating # 5: Off White UV Primer # 99-4647-07, supplied by Forest Paint Company, 1011 McKinley Ave. Eugene Oregon 97402.

Coating # 1 is described by the supplier as an acrylic urethane. Coating # 2 is described by the supplier as a cationic UV sealer. Coating # 3 is described by the supplier as a polyester UV filler. Coating # 4 is described by the supplier as a polyester / epoxy UV filler. Coating # 5 is described by the supplier as a first-hand UV coating of epoxy. The Masonite substrates coated with UV were then coated with a # 1- # 13 water-based formulation. The Examples # 1- # 13 were placed in a 175 μm wet film (microns) on the coated boards, which were prepared as described above. The wet coatings were allowed to dry for 30 minutes at 25 seconds. The boards were then placed in a 502C oven for 30 minutes. After waiting at least 24 hours, the adhesion was classified using a Gardner crosslinked adhesion tester (sheet PA-2054) and following the test method of ASTM D-3359. The coating was marked with the adhesion tester and a Scotch® Magic® tape (# 810) was applied to the marked area. The tape was removed according to the test method of ASTM D-3359. The classification of the adhesion for each of the examples in the UV coated and cured boards are given in Table II. Table II 0 indicates complete removal of the coating; 5 indicates that no coating was removed; 2, 3, and 4 represent intermediate levels of adhesion.

The results clearly show that the Examples 2 to 11 and Example 13, which are in accordance with the invention, all exhibit improved adhesion relative to the two comparative examples, Example # 1 and Example @ 12, which do not incorporate the invention. The above results are not predictable from the prior art. As demonstrated below, coatings that can adhere well and thus be suitable for coating a particular thermoplastic substrate may not adhere well to another thermoplastic substrate. Therefore, it is not possible to predict that a composition that adheres well to and is suitable for coating a thermoplastic material with low interlacing, will adhere well to and be suitable for coating a highly interlaced thermoset material, such as a UV coating. The following examples also indicate otherwise, that a composition that adheres well to a highly interlaced thermoset substrate may not adhere well to a thermoplastic substrate. Examples 1, 3, 8 and 9 above were placed on the following thermoplastic materials: 1) Plexiglas® - a polymethyl methacrylate supplied by Atohaas North America, 100 Independence Mali West, Philadelphia, PA. 2) GE Noryl® PX844 - a high impact poly-styrene mixed polymer and polyphenylene oxide, supplied by Standard Plaque Inc. 17271 Francis St. Melvindale, MI 48122. 3) GE Lexan® ML4291-7502 - a polycarbonate supplied by Standard Plaque Inc. 17271 Francis St. Melvindale, MI 48122. 4) GE Cycolac AR-3501 - an ABS plastic, supplied by Standard Plaque Inc. 17271 Francis St. Melvindale, MI 48122. Examples # 1, 3, 8 and 9 above were placed in wet film thicknesses of 175 μm, on four plastic materials. The wet coatings were allowed to dry for 30 minutes at 25 ° C. The boards were then placed in an oven at 50 ° C for 30 minutes. After waiting at least 24 hours, the adhesion was classified using a Gardner crosslinked adhesion tester (sheet PA-2054) and following the test method ASTM D-3359. The coating was marked with the adhesion tester. Scotch® tape was applied Magic® (# 810) to the marked area. The tape was removed as indicated in the test method of ASTM D-3359. The classification of the adhesion for the examples on the plastic are given in Table III.

Table III The results clearly show that even a non-carbonyl functional polymer exhibits adhesion to the following thermoplastic plastics: polymethyl methacrylate, polycarbonate and ABS, and thus the polymers containing carbonyl function required in the invention, are not necessary to obtain the adhesion . When compared to data for UV curable materials, these data emphasize the fact that adhesion is not predictable and is much more difficult to obtain in highly entangled thermostatic materials, such as UV cured coatings. In contrast, only one of the examples containing the functional carbonyl polymer exhibited high impact polystyrene / polyphenylene oxide mixed thermoplastic. In essence it was found that functional carbonyl polymers are not required to obtain adhesion to thermoplastics, such as PMMA, PC and ABS, and that functional carbonyl polymers do not appear to provide adhesion to PPO / HIPS thermoplastics. The highly entangled UV-curable materials used in the present invention are a unique class of materials that o a unique set of problems not considered for standard thermoplastics.

Claims (10)

1. CLAIMS 1. A method comprising coating, in tandem, a substrate with (i) a highly interlaced coating, formed of a UV curable composition and (ii) a cured coating, formed of an aqueous composition including a polymer, the which has, as polymerized units, from 0.1 to 100%, preferably from 1 to 50% and even more preferably from 5 to 20% by weight, of the polymer of at least one monomer capable of contributing outstanding carbonyl functional groups to the polymer.
2. 2. A method, as claimed in claim 1, wherein the substrate is first coated with a highly interlaced coating (i), followed by the cured coating (ii).
3. 3. A method, as claimed in the claim 1, in which the substrate is first coated with the cured coating (ii), followed by the highly interlaced coating (i). A method, as claimed in any of the preceding claims, wherein the coating (ii) is formed of an aqueous composition comprising a polymer that includes, as polymerized units, one or more monomers, selected from the group consisting of monomers containing ethyleneureide, cyanoacetoxy-containing monomers, acetoacetoxy-containing monomers, acrolein, methacrolein, vinyl-C 1 -C 20 -alkyl ketones and amides containing keto, such as diacetone acrylamide. A method, as claimed in claim 5, in which the aqueous composition comprises a polymer that includes from 0.1 to 100%, more preferably from 1 to 50% and especially preferred from 5 to 20% by weight, of polymerized units of one or more functional acetoacetyl monomers, having the structure: 0 R] _ 0 11 I 11 A - (- C - C - C -) - B H wherein: R] _ is H, an alkyl with 1 to 10 carbon atoms, or phenyl; A is any of: R2 R3 O \ IC = C - (- R4-) a - (- X -) n - (- C - Y-) m - (- R5-) q / H * 2 R- O ti C "(- R4") to" i "x") n "i" c "Y -) - (- R5-) s" ° - H wherein: R2 is H, alkyl having 1 to 10 carbon atoms, or phenyl, substituted phenyl, halogen, CO2CH3 or CN; R3 is H, alkyl having 1 to 10 carbon atoms, or phenyl, substituted phenyl or halogen; R 4 is alkylene or substituted alkylene, having 1 to 10 carbon atoms, or substituted phenylene or phenylene; R5 is alkylene or substituted alkylene, having 1 to 10 carbon atoms; a, m, n and q are, independently, any of 0 or 1; X and Y are, independently, either of -NH- or -0-; B is A, alkyl having 1 to 10 carbon atoms, or phenyl, substituted phenyl or a heterocyclic group. 6. A method, as claimed in claim 5, wherein the monomers are: acetoacetoxyethyl methacrylate (AAEM), acetoacetoxyethyl acrylate (AAEA), acetoacetoxypropyl methacrylate, allyl acetoacetate, acetoacetoxybutyl methacrylate, methacrylate 2,3-di (acetoacetoxy) propyl, vinyl acetoacetate, or combinations thereof. A method, as claimed in any of the preceding claims, wherein the polymer used in the coating (ii) is a copolymer comprising the carbonyl functionality, wherein this copolymer comprises, as polymerized units, from 0 to 99.9% , preferably from 50 to 99%, more preferably from 80 to 95%, by weight, of one or more copolymerizable monomers. Preferably, the copolymerizable monomers are selected from the group consisting of unsaturated and unsubstituted, saturated and momonetillenically unsaturated carboxylic acid ester monomers, such as methyl (meth) acrylate, (meth) ethyl acrylate. (meth) butyl acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, oleyl (meth) acrylate, palm (methyl) acrylate stearyl (meth) acrylate, methyl itaconate, methyl fumarate, butyl fumarate, glycidyl methacrylate, dicyclopentadienyl (meth) acrylate, isocyanatoethyl methacrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, met) N, N'-dimethylamino acrylate and vinyl acetate; monomers of substituted and unsubstituted carboxylic acids and their anhydrides, such as (meth) acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid and maleic anhydride; monomers of substituted and unsubstituted (meth) acrylamides; styrene and substituted styrene monomers; other substituted and unsubstituted vinyl monomers, such as vinyl chloride, vinylidene chloride and N-vinylpyrrolidone; other substituted and unsubstituted alkylene monomers, such as ethylene, propylene, butylene and isopropylene; and acrylonitrile and methacrylonitrile. A method, as claimed in any of the preceding claims, wherein the polymer used in coating (ii) comprises, as polymerized units, from 0.1 to 25% by weight of polyfunctional, substituted or unsubstituted ethylenically unsaturated monomers, such such as allyl methacrylate, diallyl phthalate, 1,4-butylene glycol di (meth) acrylate, 1,6-hexanediol diacrylate and divinylbenzene. A method, as claimed in any of the preceding claims, wherein the polymer used in the coating (ii) comprises functional sloping portions sufficient to supply the polymer with an acid number of from 1 to 325, preferably from 3 to 130 10. A method, as claimed in any of the preceding claims, wherein the polymer used in the coating (ii) has a glass transition temperature between -40 and + 120QC and / or a weight-average molecular weight by the gel permeation chromatography (GPC) of 500 to 5,000,000 and / or an average particle size of 20 to 1000 nm, more preferably 30 to 500 nm.