MXPA01001712A - Thermosetting compositions containing epoxy functional polymers prepared by atom transfer radical polymerization - Google Patents

Abstract

A thermosetting composition comprising a co-reactable solid, particulate mixture of (a) epoxy functional polymer, and (b) co-reactant having functional groups reactive with the epoxy groups of (a), e.g., dodecanedioic acid, is described. The epoxy functional polymer is prepared by atom transfer radical polymerization and has well defined polymer chain architecture and polydispersity index of less than 2.5. The thermosetting compositions of the present invention have utility as powder coatings compositions.

Description

THERMO-COMPOUND COMPOSITIONS THAT CONTAIN POLYMERS E P OXI - FUNC I ONALE S PREPARED BY POLYMERIZATION OF RADICALS BY ATOMIC TRANSFER FIELD OF THE INVENTION The present invention relates to thermosetting compositions of one or more epoxy-functional polymers and one or more coreactants having functional groups that are reactive with the epoxides. The epoxy functional polymer is prepared by radical polymerization by atomic transfer and has a well defined polymer chain structure, molecular weight and molecular weight distribution. The present invention also relates to methods of coating a substrate, to substrates coated by such methods and to composite coating compositions. BACKGROUND OF THE INVENTION The reduction of the environmental impact of coating compositions, in particular that associated with air emissions of volatile organic compounds during their use, has been an area of increasing research and development. «-. , - .. í * in recent years. Consequently, the interest deposited on the powder coatings has been increasing due, in part, to their inherently low volatile organic content (VOC), which significantly reduces air emissions during the application process. While both thermoplastic and thermosetting powder coating compositions can be purchased commercially, thermosetting powder coatings are typically more desirable because of their superior physical properties, example hardness and solvent resistance. Low VOC coatings are particularly desirable in the original equipment manufacturing (OEM) market for automobiles, due to the relatively large volume of coatings used. However, in addition to the reduction of low VOC content, automobile manufacturing has very strict requirements as regards the coatings used. For example, it is typically required that the transparent outer layers for automotive OEMs have a combination of good external durability, resistance to acid corrosion and water stains, and excellent gloss and appearance. While liquid outer layers, in particular liquid coatings cured with epoxyacids, can provide such properties.

^^^^^^^ ^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ These have the undesirable drawback of higher VOC levels in relation to powder coatings, which have essentially zero levels of VOC. Epoxy-based powder coatings, such as epoxy acid powder coatings, are known and have been developed for use as transparent outer coatings for automotive OEMs. However, its use has been limited due to deficiencies in, for example, flow, appearance and storage stability. The Epoxy-based powder coating compositions typically contain a coreactant, for example a cross-linking agent, having functional groups that are reactive with the epoxides, for example dodecanedioic acid, and a functional epoxy polymer, for example an acrylic copolymer prepared in part from glycidyl methacrylate. The epoxy-functional polymers used in said epoxy-based powder coating compositions are typically prepared by standard, i.e., non-living, radical polymerization methods, which provide little control on the molecular weight, the molecular weight distribution and the structure of the polymer chain. The physical properties, for example the glass transition temperature (Tg) and the melt viscosity, of a §F The given polymer can be directly related to its molecular weight. Higher molecular weights are typically associated with, for example, higher Tg values and melt viscosities. The physical properties of a polymer having a broad molecular weight distribution, for example having a polydispersity index (IPD) above 2.0 or 2.5, can be characterized as an average of the individual physical properties of, and of the indeterminate interactions between, the various polymeric species that constitute it. As such, the physical properties of polymers having broad molecular weight distributions can be variable and difficult to control. The structure of the polymer chain, or architecture, of a copolymer can be described as the sequence of monomeric residues along the backbone or polymer chain. For example, an epoxy-functional copolymer prepared by standard techniques of radical polymerization will contain a mixture of polymer molecules having variable individual epoxy equivalent weights. Some of this polymer molecules can be really free of epoxy functionality. In a thermosetting composition, the formation of a three-dimensional crosslinked network depends on the functional equivalent weight, as well as on the architecture of the individual polymeric molecules that constitute it. Polymer molecules that have little or no reactive functionality (or that have functional groups that are unlikely to participate in the cross-linking reactions due to their location along the polymer chain) will contribute little or nothing to the formation of the three-dimensional crosslinked network, giving rise to non-optimal physical properties of the finally formed polymer, for example a cured or thermoset coating. The continuous development of new and improved epoxy-based powder coating compositions having essentially zero levels of VOC and a combination of favorable performance properties is desirable. In particular, it would be desirable to develop powder coating compositions based on epoxy containing epoxy-functional polymers with well-defined molecular weight and polymer chain structure and narrow molecular weight distributions, eg, IPD values less than 2.5. It is desirable to control the architecture and polydispersity of the polymer Epoxy, in the sense that it allows to obtain higher Tg and lower melt viscosities than comparable epoxy polymers prepared by conventional processes, giving rise to thermosetting particulate compositions which are They are resistant to caking and have better physical properties, International Patent Publication WO 97/18247 and US Patent Nos. 5,763,548 and 5,789. 487 disclose a radical polymerization process referred to as radical polymerization by atomic transfer (PRTA) PRTA is described as a radical radical polymerization that results in the formation of (co) polymers having a molecular weight and a predictable molecular weight distribution It is also described that the PRTA process provides highly uniform products with a controlled structure (ie controllable topology, composition, etc.) The patents x548 and '487 and the patent publication WO 97/18247 also describe (co) polymers prepared by PRTA, which are useful in a wide variety of applications, for example in paints and coatings. In addition to the present invention, there is provided a thermosetting composition consisting of a solid particulate mixture that can be coactivated by: (a) epoxy-functional polymer prepared by radical polymerization by atomic transfer initiated in ^^ ¡g¡g | g ^ jÍ ^^^^^^^^^^^^^^^^^^^^^^^ of an initiator that has at least one group that is transferable by radicals and where said epoxy-functional polymer contains at least one of the following polymer chain structures I and II: 5 I - [(M) p- (G) q] x- and II - [(G) q- (M) P] X- 10 where M is a residue, which is free of oxirane functionality, of at least one ethylenically unsaturated radical polymerizable monomer; G is a residue, having oxirane functionality, of at least one ethylenically unsaturated radical polymerizable monomer; p and q represent numbers means of the residues that appear in a block of residues in each polymer chain structure, and p, q and x are each individually selected for each structure, such that said epoxy-functional polymer has a number-average molecular weight of at least 250. , and 20 (b) coreactant having functional groups reactive with the epoxy groups of (a). According to the present invention, a method of coating a substrate with the thermal composition is also provided. ^^^^^^^^^^^^^^^^^^ ^^^^^ ^ ^ ^ ^ ^ ^ ^^^^^^^^^^^^^^^ - ¿ mourandcible described above. Also provided, according to the present invention, is a multi-component composite coating composition consisting of a base layer deposited from a pigmented film-forming composition and a transparent outer layer applied to the base layer. The transparent outer layer contains the thermosetting composition described above. Apart from the operational examples, or where indicated Anything different, all numbers expressing quantities of components, reaction conditions, etc., used in the specification and in the claims are to be understood as modified in all cases by the term "approximately". As used herein, the term "polymer" is intended to refer to both homopolymers, ie, polymers made from a single species of monomers, and copolymers, ie, polymers made from two or more species of monomers. DETAILED DESCRIPTION OF THE INVENTION The thermosetting compositions according to the present invention contain one or more epoxy-functional polymers. As used herein and in the claims, by " > »» - - ». , - ^ ^ -'THTrr - - - «^ ...« -. "Epoxy-functional lime" is meant a polymer having two or more epoxy groups in terminal and / or pendant positions, which are capable of reacting and forming covalent bonds with compounds containing reactive functional groups with epoxides, for example hydroxyl, thiol, amine and carboxylic acid groups The epoxy-functional polymer of the present invention is prepared by radical polymerization by atomic transfer (PRTA) .The PRTA method is described as a "living polymerization", that is to say, a polymerization with growth of the chain that propagates essentially without chain transfer and essentially without chain termination.The molecular weight of a polymer prepared by PRTA can be controlled by the stoichiometry of the reactants, ie, the initial concentration of the monomer (s) and of the initiator (s) In addition, the PRTA also provides polymers that have characteristic such as, for example, narrow molecular weight distributions, for example IPD values less than 2.5, and well-defined structure of the polymer chain, for example block copolymers and alternating copolymers. The PRTA process can be described, in general, as consisting of: polymerizing one or more polymeric monomers ristables by radicals in the presence of an initiation system, form a polymer and isolate the formed polymer. The initiation system consists of: an initiator that has an atom or group transferable by radicals; a transition metal compound, that is, a catalyst, which participates in a reversible redox cycle with the initiator, and a ligand, which coordinates with the transition metal compound. The PRTA process is described in greater detail in the international patent publication WO 97/18247 and in US Patents No. 5,763,548 and No. 5,789,487. In preparing the epoxy-functional polymers of the present invention, the initiator can be selected from the group consisting of linear or branched aliphatic compounds, cycloaliphatic compounds, aromatic compounds, polycyclic aromatic compounds, heterocyclic compounds, sulfonyl compounds, sulfenyl compounds, esters of carboxylic acids, polymeric compounds and mixtures thereof, each having at least one radical-transferable group, which is typically a halo group. The initiator can also be substituted with functional groups, for example oxiranyl groups, such as glycidyl groups. Additional useful primers and the various radical-transfer groups that may be associated thereto are described on pages 42 to 45 of the international patent publication WO 97/18247. Polymeric compounds (including oligomeric compounds) having radical-tradable groups can be used as initiators and are referred to herein as "macroinitiators". Examples of macroinitiators include, but are not limited to, polystyrene prepared by cationic polymerization and with a terminal halide, for example, chloride, and a polymer of 2- (2-bromopropionoxy) ethyl acrylate and one or more alkyl (meth) acrylates. , for example butyl acrylate, prepared by conventional non-living radical polymerization. Macroinitiators can be used in the PRTA process to prepare graft polymers, such as grafted block copolymers and comb coppers. On pages 31 to 38 of the international patent publication WO 98/01480, a further discussion of macroinitiators can be found. Preferably, the initiator can be selected from the group consisting of halomethane, methylene dihalide, haloform, carbon tetrahalide, l-halo-2,3-epoxypropane, methanesulfonyl halide, p-toluenesulfonyl halide, methanesulfenyl halide, p-toluenesulfenyl, 1-phenylethyl halide, C 1 -C 6 alkyl ester of 2-acid Ci-Cβ halocarboxylic acid, p-halomethylstyrene, monohexakis (-haloalkyl-C6-C6) benzene, diethyl-2-halo-2-methyl malonate, ethyl 2-bromoisobutyrate and mixtures thereof. A particularly preferred initiator is diethyl -2-bromo-2-5 methyl malonate. Catalysts that can be used in the preparation of epoxy functional polymers of the present invention include any transition metal compound that can participate in a redox cycle with the initiator and the polymer chain in growth. It is preferred that the transition metal compound does not form carbon-metal direct bonds with the polymer chain. The transition metal catalysts useful in the present invention can be represented by the following general formula III: III III MTn + Xn where MT is the transition metal, n is the formal charge on the transition metal and has a value of 0 to 7 and X is a counterion or covalently bonded component. Examples of the transition metal (MT) include, but are not limited to, Cu, Fe, Au, Ag, Hg, Pd, Pt, Co, Mn, Ru, Mo, Nb and Zn. Examples of X include, but are not limited to, halogen, hydroxy, oxygen, C?-C6 alkoxy, cyano, cyanate, thio- cyanate and azido. A preferred transition metal is Cu (I) and X is preferably halogen, for example chloride. Accordingly, a preferred class of transition metal catalysts are copper halides, for example Cu (I) Cl. It is also preferred that the transition metal catalyst contains a small amount, for example 1 mole percent, of a redox conjugate, for example Cu (II) Cl2 when Cu (I) Cl is used. Additional catalysts useful in the preparation of the epoxy functional polymers of the present invention are described on pages 45 and 46 of the international patent publication WO 97/18247. On pages 27 to 33 of the international patent publication WO 97/18247, redox conjugates are described. The ligands that can be used in the preparation of epoxy functional polymers of the present invention include, but are not limited to, compounds having one or more nitrogen, oxygen, phosphorus and / or sulfur atoms, which can be coordinated with the transition metal catalyst compound, for example through sigma and / or pi bonds. Examples of useful ligands include, but are not limited to: unsubstituted and substituted pyridines and bipyridines; porphyrins; cryptandos; crown ethers, for example 18-crown-6; polyamines, for example ethylene diamine; glycols, for example The alkylene glycols, such as ethylene glycol; carbon monoxide, and coordinating monomers, for example styrene, acrylonitrile and hydroxyalkyl (meth) acrylates. A preferred class of ligands are the substituted bipyridines, for example 4,4'-dialkyldipyridyls. Additional ligands are disclosed which can be used in the preparation of epoxy-functional polymers of the present invention on pages 46 to 53 of the international patent publication WO 97/18247. In preparing the epoxy-functional polymers of the present invention, the amounts and relative proportions of initiator, transition metal compound and ligand are those for which the PRTA is carried out with the greatest effectiveness. The amount of initiator used can vary widely and is typically present in the reaction medium at a concentration of 10"4 moles / liter (M) to 3 M, for example 10" 3 M to 10"1 M. As the molecular weight of the epoxy-functional polymer may be directly related to the relative concentrations of initiator and monomer (s), the molar ratio of initiator to monomer is an important factor in the polymer preparation. The molar ratio of initiator to monomer is typically in the range of 10"4: 1 to 0.5: 1, eg, 10 ~ 3: 1 to 5x10" 2: 1. In preparing the epoxy-functional polymers of the ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ j ^^^^^^^^ ^^^^^ j ^^^^^^^^ I sat invention, the molar ratio of transition metal compound to initiator is typically in the range of 10 ~: 1 to 10: 1, eg, 0.1: 1 to 5: 1. The molar ratio of ligand to transition metal compound is typically in the range of 0.1: 1 to 100: 1, for example, 0.2: 1 to 10: 1. The epoxy functional polymers useful in the thermosetting compositions of the present invention can be prepared in the absence of solvent, i.e., by means of a bulk polymerization process. In general, the epoxy-functional polymer is prepared in the presence of a solvent, typically water and / or an organic solvent. Suitable classes of organic solvents include, but are not limited to, esters of carboxylic acids, ethers, cyclic ethers, C5-C? Alca alkanes, C5-C8 cycloalkanes, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, amides, nitriles, sulfoxides. , sulfones and their mixtures. Supercritical solvents, such as C02, C-C4 alkannes and fluorocarbons, can also be used. A preferred class of solvents are aromatic hydrocarbon solvents, with particularly preferred examples being xylene and mixed aromatic solvents, such as those marketed by Exxon Chemical America under the trademark SOLVESSO. Additional solvents are described in greater detail on pages 53 to 56 of the international patent publication WO 97/18247. The epoxy functional polymer is typically prepared at a reaction temperature in the range of 25 ° C to 140 ° C, for example 50 ° C to 100 ° C, and a pressure in the range of 1 to 100 5 atmospheres, normally to the ambient pressure. Radical polymerization by atomic transfer is typically completed in less than 24 hours, for example, between 1 and 8 hours. When the epoxy functional polymer is prepared in the presence of a solvent, the solvent is removed after the polymer has been formed by suitable means known to those of ordinary skill in the art, for example vacuum distillation. Alternatively, the polymer can be precipitated from the solvent, filtered, washed and dried according to known methods. After removal of the solvent or separation therefrom, the epoxy-functional polymer typically has a solids content (measured by placing a 1 gram sample in an oven at 110 ° C for 60 minutes) of at least one 95 percent, and preferably at least 98 percent by weight, based on the total weight of the polymer. Before use in the thermosetting compositions of the present invention, the transition metal catalyst The PRTA and its associated ligand are typically separated or removed from the epoxy-functional polymer. The removal of the PRTA catalyst is achieved using known methods, including, for example, the addition of a catalyst binding agent to the mixture of the polymer, the solvent and the catalyst, followed by filtration. Examples of suitable catalyst binding agents include, for example, alumina, silica, clay or a combination thereof. A mixture of the polymer, the solvent and the catalyst of the PRTA can be passed through a bed of catalyst binding agent. Alternatively, the PRTA catalyst can be oxidized in situ and retained in the functional epoxy polymer. The epoxy-functional polymer can be selected from among The group consisting of linear polymers, branched polymers, hyperbranched polymers, star polymers, graft polymers and mixtures thereof. The shape, or coarse architecture, of the polymer can be controlled by choosing the initiator and the monomers used in its preparation.

Linear epoxy-functional polymers can be prepared using initiators having one or two radical-transferrable groups, for example diethyl-2-halo-2-methyl malonate and, -dichloroxylene. Polymers can be prepared The branched epoxy functional groups using branching monomers, ie, monomers containing radical-transferable groups or more than one ethylenically unsaturated radical-polymerizable group, for example 2- (2-5-bromopropionoxy) ethyl acrylate, -chloromethylstyrene and bis (methacrylate) of diethylene glycol. Hyperbranched epoxy functional polymers can be prepared by increasing the amount of branching monomer used. Star-functional epoxy polymers can be prepared using initiators having three or more groups transferable by radicals, for example hexakis (bromomethyl) benzene. As is known to those of ordinary skill in the art, star polymers can be prepared by core-arm or arm-core methods. In the core-arm method, The star polymer is prepared by polymerizing monomers in the presence of the polyfunctional initiator, for example hexakis (bromomethyl) benzene. Polymer chains, or arms, of similar composition and architecture grow outward from the initiator core in the core-arm method. 20 In the arm-core method, the arms are prepared separately from the core and may eventually have different composition, architecture, molecular weight and IPD. The arms can have different epoxy equivalent weights and some ^^^ ß ^^^^^^^^^^^^^^^^^^ 1 ^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^ s ^^^^ * ^^^^^ ßÉ ^^^ fc ^^^ 6 can be prepared without any epoxy functionality. After the preparation of the arms, they join the nucleus. For example, the arms can be prepared by PRTA using glycidyl-functional initiators. These arms can then be attached to a core having three or more active hydrogen groups that can react with epoxides, for example carboxylic or hydroxyl groups. The core may be a molecule such as citric acid, or a star-core polymer polymer prepared by PRTA and having terminal groups containing reactive hydrogen, for example carboxylic acid, thiol or hydroxyl groups. The reactive hydrogen groups in the core can react with the glycidyl-functional or epoxy-functional initiator residue along the backbone of the arms. An example of a core prepared by PRTA methods that can be used as a core in a core arm-core polymer PRTA is described as follows. In the first step, 6 moles of methyl methacrylate are polymerized in the presence of one mole of 1,3,5-tris (bromomethyl) benzene. In the second stage, 3 moles of 2-hydroxyethyl methacrylate are fed into the reaction mixture. You can connect three arms prepared by Vivid PRTA of variable composition or equivalent and each containing a single epoxide group, ^ a-Jj-MBüBf * ^^^ g ^^^^^^^^^^^^^^^ j ^^^^^^^^^^^^^^^^^^^^^^^ ^^^^ M ^^ e ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ from an epoxide-functional initiator, to the hydroxy-terminated core by reaction between the hydroxy groups of the core and the epoxide group of each of the arms. Residues having oxirane functionality can be introduced into the living arms of the star-arm-core polymer by continuing the PRTA process in the presence of radically polymerizable ethylenically unsaturated oxirane-functional monomers, for example glycidyl methacrylate. Epoxy-functional polymers can be prepared in the form of graft polymers using a macroinitiator, as previously described herein. The graft, branched, hyperbranched and star polymers are described in greater detail on pages 79 to 91 of the international patent publication WO 97/18247. The polydispersity index (IPD) of the epoxy-functional polymers useful in the present invention is typically less than 2.5, more typically less than 2.0, and preferably less than 1.8, for example 1.5. As used herein and in the claims, the "polydispersity index" is determined by the following equation: (weight average molecular weight (Mp) / number average molecular weight (Mn)). A monodisperse polymer has an IPD of 1.0. In addition, such a ^^ ^ jÉfeí ^^^^^ mo is used here, Mn and Mp are determined by gel permeation chromatography using polystyrene standards. The general polymeric chain structures I and II represent, together or separately, one or more structures containing the architecture of the polymer chain, or backbone, of the functional epoxy polymer. The subscripts p and q of the general polymeric chain structures I and II represent the average numbers of residues that appear in the M and G blocks of the residues, respectively. The subscript x represents the number of segments of blocks M and G, that is, x-segments. The subscripts p and q may each be the same or different for each x-segment. The following are presented for purposes of illustration of the various polymeric architectures that are represented by the polymeric chain structures I and II. Polyblock polymer architecture: When x is 1, p is 0 and q is 5, the general structure of polymer chain I represents a homoblock of 5 residues G, as is more specifically represented by the following general formula IV. IV - (G) - (G) - (G) - (G) - (G) - Architecture of diblock copolymer: When x is 1, p is 5 and q is 5, the general structure of polymer chain I represents a diblock of 5 M residues and 5 G residues, as is more specifically represented by the following general formula V. 5 V - (M) - (M) - (M) - (M) - (M) - (G) - (G) - (G) - (G) - (G) - Alternating copolymer architecture: When x is greater than 1, for example 5, ypyq are each 1 for each x segments, the polymeric chain structure I represents an alternating block of residues M and G, as more specifically represented by the following general formula VI. VI - (M) - (G) - (M) - (G) - (M) - (G) - (M) - (G) - (M) - (G) - 15 Gradient copolymer architecture: When x is greater than 1, for example 3, and p and q are each independently in the range of, for example, 1 to 3, for each x segments, the polymer chain structure I represents a block in gradient of residues M and G, as 20 is more specifically represented by the following general formula VII. VII - (M) - (M) - (M) - (G) - (M) - (M) - (G) - (G) - (M) - (G) - (G) - (G) - ^^ g ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ j ^^^^^^^^^^ »^^^ ^^ ßBaíaß ^^^^^^ g! ^^^^^ Gradient copolymers can be prepared from two or more monomers by PRTA methods and are generally described as having an architecture that changes gradually and in a way systematic and predictable throughout the polymer skeleton. The gradient copolymers can be prepared by PRTA methods (a) by varying the ratio of monomers fed into the reaction medium in the course of the polymerization, (b) using a monomer feed containing monomers with different polymerization rates or (c) with a combination of (a) and (b). The gradient copolymers are described in greater detail on pages 72 to 78 of the international patent publication WO 97/18247. Still referring to the general polymeric chain structures I and II, M represents one or more types of residues that are free of oxirane functionality and p represents the average total number of M residues that appear per block of M residues (M block) in x segments. The - (M) p- portion of the general structures I and II represents (1) a homoblock of a single type of M residues, (2) an alternating block of two types of M residues, (3) a polyblock of two or more types of waste M or (4) a block in gradient of two or more types of waste M.

For illustrative purposes, when block M is prepared from, for example, 10 moles of methyl methacrylate, the - (M) p- portion of structures I and II represents a homoblock of 10 residues of methyl methacrylate. In case block M is prepared from, for example, 5 moles of methyl methacrylate and 5 moles of butyl methacrylate, the - (M) p- portion of the general structures I and II represents, depending on the preparation conditions, as is known to one of ordinary skill in the art: (a) a diblock of 5 residues of methyl methacrylate and 5 residues of butyl methacrylate having a total of 10 residues (ie, p = 10); (b) a diblock of 5 residues of butyl methacrylate and 5 residues of methyl methacrylate having a total of 10 residues; (c) an alternating block of residues of methyl methacrylate and butyl methacrylate starting with a residue of methyl methacrylate or with a residue of butyl methacrylate and having a total of 10 residues; or (d) a gradient block of methyl methacrylate and butyl methacrylate residues that starts with methyl methacrylate residues or with butyl methacrylate residues and has a total of 10 residues. In addition, with respect to the general polymeric chain structures I and II, G represents one or more types of resin. duos that have oxirane functionality and q represents the average total number of G residues that appear per block of G residues (block G). Accordingly, the portions - (G) q- of the polymer chain structures I and II can be described in a manner similar to that of the - (M) p- portions indicated above. The residue M of the polymeric chain general structures I and II is derived from at least one ethylenically unsaturated radical polymerizable monomer. As used Here and in the claims, "radically polymerizable ethylenically unsaturated monomer" and similar terms are intended to include vinyl monomers, allylic monomers, olefins and other ethylenically unsaturated monomers that are radically polymerizable. The classes of vinyl monomers from which M can be derived include, but are not limited to, (meth) acrylates, vinyl aromatic monomers, vinyl halides and vinyl esters of carboxylic acids. As used herein and in the claims, by the terms "(meth) acrylate" and the like are referred to both methacrylates and acrylates. Preferably, the residue M is derived from at least one of alkyl (meth) acrylates having from 1 to 20 carbon atoms in the alkyl group. As an example specific peaks of alkyl (meth) acrylates having from 1 to 20 carbon atoms in the alkyl group from which the residue M can be derived include, but are not limited to, methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, propyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, (met) tere-butyl acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, isobornyl (meth) acrylate, Cyclohexyl (meth) acrylate and 3,3,5-trimethylcyclohexyl (meth) acrylate. The residue M can also be selected from monomers having more than one (meth) acrylate group, for example (meth) acrylic anhydride and diethylene glycol bis (meth) acrylate. The residue M can also be selected from alkyl (meth) acrylates containing radical-transferable groups which can act as branching monomers, for example 2- (2-bromo-propionoxy) ethyl acrylate. Specific examples of vinyl aromatic monomers from which M can be derived include, but are not limited to, styrene, p-chloromethylstyrene, divinylbenzene, vinylnaphthalene and divinylnaphthalene. The vinyl halides from which M can be derived include, but are not limited to, chloride ^^^^^^ A ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^ j ^^^^^^^^^ jí ^^^^^^^^^^? ^^^^^^^^^^ vinyl and vinylidene fluoride. The vinyl esters of carboxylic acids from which M can be derived include, but are not limited to, vinyl acetate, vinyl butyrate, vinyl 3,4-dimethoxybenzoate and vinyl benzoate. As used herein and in the claims, by "olefin" and similar terms reference is made to unsaturated aliphatic hydrocarbons having one or more double bonds, such as those obtained by fractionation of petroleum fractions. Specific examples of olefins from which M can be derived include, but are not limited to propylene, 1-butene, 1,3-butadiene, isobutylene and diisobutylene. As used herein and in the claims, by "allylic monomer (s)" reference is made to monomers containing substituted and / or unsubstituted allylic functionality, that is, one or more radicals represented by the following general formula VIII, VIII H2C = C (R4) -CH2- where R4 is hydrogen, halogen or a Ci to C4 alkyl group. Most commonly, R 4 is hydrogen or methyl and, consequently, general formula VIII represents the unsubstituted (meth) allyl radical. Examples of allylic monomers include, ** .. ^ afa .. although without limitation: (meth) allyl alcohol; (meth) allyl ethers, such as methyl (meth) allyl ether; allyl esters of carboxylic acids, such as (meth) allyl acetate, (meth) allyl butyrate, 5 (meth) allyl 3,4-dimethoxybenzoate and (meth) allyl benzoate. Other radically polymerizable ethylenically unsaturated monomers from which M can be derived include, but are not limited to: cyclic anhydrides, for example maleic anhydride, 1-cyclopentene-1, 2-dicarboxylic anhydride and itaconic hydrido; esters of acids which are unsaturated, but not unsaturated, ethylene, for example undecylenic acid methyl ester, and diesters of ethylenically unsaturated di-basic acids, for example diethyl maleate. 15 Residue G of general polymer chain structures I and II typically derived from monomers having epoxy functionality, ie, epoxide or oxirane. Preferably, residue G is derived from at least one (meth) acrylate, (meth) acrylate, 3, 4-epoxycyclohexylmethyl (meth) acrylate 2- (3,4-epoxy-clohexyl) ethyl and allyl glycidyl ether. In a particularly preferred embodiment of the present invention, the residue G is derived from glycidyl methacrylate. Alternatively, the epoxy functionality can be incorporated into the epoxy-functional polymer by post-reaction, such as by preparing a hydroxyl-functional polymer and converting it to an epoxy-functional polymer by reaction with epichlorohydrin. The subscripts p and q represent the average number of residues that appear in a block of residues in each polymer structure. Typically, p and q each independently has a value of 0 or more, preferably at least 1 and more preferably at least 5 each is general polymer-structures I and II. Also, subscripts p and q are each independently, preferably less than 20 and, more preferably, less value of typically less than 15 100 each of general polymer structures I and II. The values of the subscripts p and q may vary between any combination of these values, including the indicated values. Moreover, the sum of p and q is at least 1 in an x-segment and q is at least 1 in at least one x-segment in the polymer. The subscript x of the polymeric general structures I and II typically has a value of at least 1. In addition, the subscript x typically has a value less than 100, preferably less than 50, and more preferably less than 10. The value of the subscript x may vary between any combination of these values, including the indicated values. If more than one of structures I and / or II appear in the polymer molecule, x can have different values for each structure (like p and q), allowing a variety of polymeric architectures, such as gradient copolymers. The epoxy-functional polymer of the present invention can further be described as having at least one of the following general polymeric chain structures IX and X: IX f - [[(M) p- (G) q] x- (M) rT] z and X f- t [(G) q- (M) p] x- (G) sT] z where p, q, x, M and G have the same meanings as those described here previously. The subscripts r and s represent the average numbers of residues that appear in the respective waste blocks M and G. The portions - (M) r- and - (G) s - of the general formulas IX and X have meanings similar to those previously described here with respect to the portions - (M) p- and - (G) q-. Structures IX and X can represent the polymer itself or, alternatively, each of the structures can ~~ - * - * ^ ^ ^ ^ j ^^^^^^ XK ^^^ contain a terminal segment of the polymer. For example, when z is 1, structures IX and X may represent a linear polymer, prepared by PRTA using an initiator having 1 group transferable by radicals. When z is 2, structures IX and X may represent a linear "leg" extending from an initiator having 2 groups transferable by radicals. Alternatively, when z is greater than 2, structures IX and X can each represent an "arm" of a star polymer prepared by PRTA, using an initiator having at least 2 radical-transferable groups. The symbol f of the general formulas IX and X is, or is derived from, the initiator residue used in the PRTA preparation of the polymer and is free of the group transferable by initiator radicals. For example, when an epoxy-functional polymer is initiated in the presence of benzyl bromide, the symbol f, more specifically f-, is the benzyl residue, The symbol f can also be derived from the starter residue. For example, when the epoxy-functional polymer is initiated using epichlorohydrin, the symbol f, more specifically f-, is the 2,3-epoxypropyl residue, OR CH The 2,3-epoxypropyl residue can then be converted into, for example, a 2,3-dihydroxypropyl residue. Derivatives or conversions of the initiator residue are preferably carried out at a point in the PRTA process in which the loss of epoxy functionality along the polymer backbone is minimal, for example before incorporating a block of residues having epoxy functionality. In general formulas IX and X, the subscript z is equal to the number of epoxy-functional polymer chains that are attached to f. The subscript z is at least 1 and can have a wide range of values. In the case of comb or graft polymers, where f is a macroinitiator having several radical transferable groups, z may have a value above 10, for example 50, 100 or 1,000. Typically, z is less than 10, preferably less than 6, and more - ^ ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡is 1 or 2. In a preferred embodiment of the present invention, z is 1 or 2. The symbol T of the general formulas IX and X is, or is derived from, the group transferable by radicals of the initiator. For example, when the epoxy-functional polymer is prepared in the presence of diethyl-2-bromo-2-methyl malonate, T may be the bromine group transferable by radicals. The group transferable by radicals may eventually be (a) eliminated or (b) chemically converted into another re-sto. In (a) or in (b), the symbol T is here considered to be derived from the group transferable by radicals of the initiator. The group which can be transferred by radicals can be removed by substitution with a nucleophilic compound, for example an alkali metal alkoxylate. However, in the present invention, it is desirable that the method by which the radical-transferable group is chemically removed or converted is also relatively smooth with respect to the epoxy functionality of the polymer. Many nucleophilic substitution reactions can result in loss of epoxy functionality of the polymer. In a preferred embodiment of the present invention, when the radical-transferable group is a halogen, the halogen can be removed by means of a mild dehalogenation reaction, which does not reduce the epoxy functionality of the polymer. The reaction is typically carried out as a post-reaction after the polymer has been formed and in the presence of at least one PRTA catalyst. Preferably, the posthalogenation reaction is carried out in the presence of a PRTA catalyst and its associated ligand. The gentle dehalogenation reaction is carried out by contacting the halogen-finished epoxy-functional polymer of the present invention with one or more ethylenically unsaturated compounds, which are not readily polymerizable by radicals in at least a portion of the low-level spectrum of conditions. which radical polymerizations are carried out by atomic transfer, to which reference will hereafter be made as "limited ethylenically unsaturated compounds polymerizable by radicals" (LEIPR compound). As used herein, "halogen-terminated" and similar terms are also intended to include pendant halogens, for example as they would be present in branched, comb and star polymers. Without wishing to be bound by any theory, we believe, based on the evidence available, that the reaction between the epoxy-functional polymer finished in halogen and one or more LEIPR compounds leads to (1) the elimination of the group k ^^ «^^« ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^ ^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^ broken the carbon-halogen terminal bond. The dehalogenation reaction is typically conducted at a temperature in the range of 0 ° C to 200 ° C, for example 0 ° C to 160 ° C and a pressure in the range of 0.1 to 100 atmospheres, for example from 0.1 to 50 atmospheres. The reaction is also typically carried out in less than 24 hours, for example between 1 and 8 hours. While the LEIPR compound can be added in less than a stoichiometric amount, it is preferably added in at least one stoichiometric amount relative to the moles of the terminal halogen present in the epoxy functional polymer. When added in an excess of a stoichiometric amount, the LEIPR compound is typically present in an amount not greater than 5%. mole percent, for example 1 to 3 mole percent, in excess of the total moles of terminal halogen. Among the limited radically polymerizable ethylenically unsaturated compounds useful for the dehalogenation of the epoxy-functional polymer of the composition of the The present invention under mild conditions includes those represented by the following general formula XI.

XI R3 Ri C = C R3 R2 In the general formula XI, Ri and R2 can be identical or different organic groups, such as: alkyl groups of 1 to 4 carbon atoms, aryl groups, alkoxy groups, ester groups, alkyl sulfur groups, acyloxy groups and alkyl groups containing nitrogen, where at least one of the groups Ri and R2 is an organic group, while the other may be an organic group or hydrogen. For example, when one of Ri or R2 is an alkyl group, the other may be an alkyl, aryl, acyloxy, alkoxy, arene, sulfur-containing alkyl group or nitrogen-containing and / or nitrogen-containing alkyl groups. The R3 groups can be the same or different groups selected from hydrogen or lower alkyl, selected in such a way that the reaction between the terminal halogen of the epoxy-functional polymer and the LEIPR compound is not avoided. In addition, a group R3 can be linked to the Ri and / or R2 groups to form a cyclic compound. It is preferred that the LEIPR compound be free of groups ^^ ¿_Jjfe3¿ifc¿ fc¿? »BJ ^ aí &g & ^ _ ^ i? C ^ halogen. Examples of suitable LEIPR compounds include, but are not limited to, 1,1-dimethylethylene, 1,1-diphenylethylene, isopropenyl acetate, alpha-methylstyrene, 1,1-dialkoxyolefin, and mixtures thereof. Further examples include dimethyl itaconate and diisobutene (2,4,4-trimethyl-pentene). For purposes of illustration, the reaction between the halogen-finished epoxy-functional polymer and the LEIPR compound, for example alpha-methylstyrene, is summarized in the following general scheme 1. General scheme 1 In the general scheme 1, P-X represents the epoxy-functional polymer finished in halogen. For each of the general polymeric structures IX and X, the subscripts r and s each independently have a value of 0 or more. The subscripts r and s each independently have a value typically less than 100, preferably less than 50, and more preferably less than 10, for each of the general polymer structures IX and X. The values of r and s may each vary between any combination of these values, including the indicated values. The functional-epoxy polymer typically has an epoxy equivalent weight of at least 128 grams / equivalent and, preferably, at least 200 grams / equivalent. The epoxy equivalent weight of the polymer is also typically less than 10,000 grams / equivalent, preferably less than 5,000 grams / equivalent and, more preferably, less than 1,000 grams / equivalent. The epoxy equivalent weight of the epoxy-functional polymer can vary between any combination of these values, including the indicated values. The number average molecular weight (Mn) of the polymer Epoxy-functional is typically at least 250, more typically at least 500, preferably at least 1,000 and, more preferably, at least 2,000. The epoxy-functional polymer also typically has an Mn of less than 16,000, preferably less than 10,000 and, more preferably, less of 5,000. The Mn of the epoxy-functional polymer can vary between any combination of these values, including the indicated values. The epoxy-functional polymer can be used in the corapo- thermosetting composition of the present invention as a resinous binder or as an additive with a separate resinous binder, which can be repaired by PRTA or by conventional polymerization methods. When used as an additive, the epoxy-functional polymer described herein typically has low functionality; for example, it can be monofunctional and with a correspondingly high equivalent weight. The epoxy-functional polymer is typically present in the thermosetting composition of the present invention in an amount of at least 0.5 percent by weight, more typically at least 30 percent by weight, preferably at least 50 percent by weight. weight and, more preferably, at least 60 weight percent, based on the total weight of the resin solids of the thermosetting composition. The thermosetting composition also typically contains epoxy-functional polymer present in an amount of less than 99.5 weight percent, more typically less than 95 weight percent, preferably less than 90 weight percent, and more preferably, less than 80 percent by weight, based on the total weight of the resin solids of the thermosetting composition. The epoxy functional polymer can be present in the thermosetting composition of the present invention in an amount in a range between any ^ g ^^^^^^^^^^^^^ j ^^^ g ^^^^^^^^^ combination of these values, including the indicated values. The thermosetting composition of the present invention also contains one or more coreactants having functional groups reactive with the epoxy functionality of the epoxy functional polymer. The coreactant (b) of the composition is not prepared by radical polymerization methods by atomic transfer. The coreactant may have functional groups selected from the group consisting of hydroxyl, thiol, primary amines, secondary amines, carboxyl and mixtures thereof. Useful buffers having amine functionality include, for example, dicyandiamide and substituted dicyan-diamides. Preferably, the coreactant has carboxylic acid groups. In one embodiment of the present invention, the coreactant has carboxylic acid functionality and is substantially crystalline. By "crystalline" it is meant that the coreactant contains at least some crystalline domains and, correspondingly, may contain some amorphous domains. Although not necessary, it is preferred that the coreactant has a lower melt viscosity than that of the epoxy-functional polymer (at the same temperature). As used herein and in the claims, by "functional groups reactive with the epoxy groups of the epoxy functional polymer" is meant that the coreactant has at least two functional groups that are reactive with the epoxy functionality. Preferably, the coreactant is a carboxylic acid functional coreactant, typically containing from 4 to 20 carbon atoms. Examples of coreactants useful in the present invention include, but are not limited to, dodecanedioic acid, azelaic acid, adipic acid, 1,6-hexanedioic acid, succinic acid, pimelic acid, sebacic acid, maleic acid, citric acid, acid itaconic, acoinic acid and its mixtures. Other suitable acid-carboxylic-functional coreactants include those represented by the following general formula XII, XII In general formula XII, R is the residue of a polyol, E is a divalent linking group having from 1 to 10 carbon atoms and n is an integer from 2 to 10. Examples of polyols from which R can derive. of the general formula XII are included, but without limitation, ethylene glycol, di (ethylene glycol), trimethylolethane, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol and their mixtures. Divalent linking groups from which E may be selected include, but are not limited to, methylene, ethylene, propylene, isopropylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, cyclohexylene, eg, 1-2. cyclohexylene, substituted cyclohexylene, for example 4-methyl-1, 2-cyclohexylene, phenylene, for example 1,2-phenylene, and substituted phenylene, for example 4-methyl-1,2-phenylene and 4-carboxylic acid-1,2-phenylene. The divalent linking group E is preferably aliphatic. The co-reactive represented by general formula XII is typically prepared from a polyol and a dibasic acid or cyclic anhydride. For example, trimethylolpropane and hexahydro-4-methylphthalic anhydride react with each other at a molar ratio of 1: 3, respectively, to form a carboxylic acid functional coreactant. This particular co-reactant can be described in relation to general formula XII as follows: R is the trimethylolpropane residue, E is the divalent linking group 4-methyl-1,2-cyclohexylene and n is 3. The carboxylic acid coreactants -functional described here with reference to general formula XII, they are also intended to include any unreacted starting material and / or coproducts, for example oligomeric species, resulting from their preparation and contained therein. The co-reactant is typically present in the thermosetting compositions of the present invention in an amount of at least 10 percent by weight and, preferably, at least 15 percent by weight, based on the total weight of the resin solids. of the composition. The coagulation 10 is also typically present in the composition in an amount of less than 70 weight percent, more typically less than 50 weight percent, preferably less than 30 weight percent, and, more preferably, less than 25 weight percent, based on the total weight of the resin solids of the composition. The amount of coreactant present in the thermosetting composition of the present invention may vary between any combination of these values, including the values indicated. The equivalent ratio of epoxy equivalents in the epoxy-functional polymer (a) to the equivalents of reactive functional groups in the coreactant (b) is typically from 0.5: 1 to 2: 1 and, preferably, from 0.8: 1 to 1.5: 1. Although equivalent ratios outside these ranges fall ^ W »? | S! ¡^^« ^ > ^^ s ^^^ Sgé ^^^ ^ & ^ within the scope of the present invention, are generally less desirable due to the appearance and performance deficiencies in the cured films obtained from them. The thermosetting composition of the present invention also typically includes one or more cure catalysts to catalyze the reaction between the reactive functional groups of the coreactant and the epoxy groups of the polymer. Examples of curing catalysts for acid-functional coreactants are tertiary amines, for example methyldi-cocoamine, and tin compounds, for example triphenyltin hydroxide. The curing catalyst is typically present in the thermosetting composition in an amount of less than 5 weight percent, eg, from 0.25 weight percent to 2.0 weight percent, based on the total weight of the resin solids in the composition. The thermosetting compositions according to the present invention may optionally include one or more co-curatives that are different from co-reactant (b) and are not prepared by PRTA methods. As used herein, by "cocurative" 20 is meant a compound having a functionality that is not reactive with the epoxide groups of the epoxy-functional polymer (a). For example, the co-curative may have functional groups that are reactive with: functional groups ^^^^^^^^^^^^^^^^ g ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^ gg ^ ¡a ^^ ¿^^^^^^^^^^^^^^^^^^^^^^^^ ü ^^^^^^ & of the coreactant (b) and / or the hydroxyl groups formed as a result of the reaction between the functional groups of the coreactant (b) and the epoxide groups of the epoxy functional polymer (a). Co-curatives may be included in the composition to optimize physical properties (e.g., resistance to impact, scratching and cracking) of the polymers obtained with it. If used, co-ccessives are typically present in the composition in amounts of less than 10 weight percent, for example 1 to 5 weight percent, based on the total weight of the resin solids of the thermosetting composition. . A useful class of co-curatives are topped polyisocyanates having two or more topped isocyanate groups, which are known to those of ordinary skill in the art. An example of a particularly useful polyisocyanate co-curative is a trimer of l-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (isophorone diisocyanate or DIIF) capped with 2-butanone oxime or e-caprolactam. The thermosetting composition of the present invention may also include pigments and fillers. Examples of pigments include, but are not limited to, inorganic pigments, for example titanium dioxide and iron oxides.; organic pigments, for example phthalocyanines, anthraquinones, quinacridones and thioindigos, and carbon blacks. Examples of fillers include, but are not limited to, silica, for example precipitated silicas, clay and barium sulfate. When used in the composition of the present invention, the pigments and fillers are typically present in amounts of 0.1 percent to 70 percent, based on the total weight of the thermosetting composition. More often, the thermosetting composition of The present invention is used as a transparent composition substantially free of pigments and fillers. The thermosetting composition of the present invention may optionally contain additives, such as waxes, for the flow and the humidification; degassing additives, such as benzoin; Adjuvant resins to modify and optimize the properties of the coating, and absorbers of ultraviolet (UV) light. These eventual additives, when used, are typically present in amounts of up to percent by weight, based on the total weight of resin solids of the thermosetting composition. The thermosetting composition of the present invention is typically prepared by first dry mixing the epoxy-functional polymer, coreactant and additives, such as flow control agents, degassing agents and catalysts, in a mixer, for example a Henshel paddle mixer. The mixer is operated for a sufficient period of time to result in a homogeneous mixture of the charged materials therein. The homogeneous dry mixture is then melt blended in an extruder, for example a double helix co-rotating extruder, operated in a temperature range of 80 ° C to 140 ° C, for example 100 ° C to 125 ° C. Optionally, the thermosetting composition can be melt blended in two or more stages. For example, a first molten mixture is prepared in the absence of curing catalyst. A second molten mixture is prepared at a lower temperature from a dry mixture of the first molten mixture and the curing catalyst. When used as a powder coating composition, the melt-blended thermosetting composition is typically milled at an average particle size of, for example, 15 to 30 microns. According to the present invention, there is also provided a method of coating a substrate, consisting of: (a) applying to said substrate a thermosetting composition, (b) coalescing said thermosetting composition to form a substantially continuous film and (c) curing said composition thermosetting by application of heat, wherein said thermosetting composition consists of a solid particulate mixture that can be corked as previously described herein. The thermosetting composition of the present invention can be applied to the substrate by any appropriate means that is known to those of ordinary skill in the art. In general, the thermosetting composition is in the form of dry powder and applied by spray application. Alternatively, the powder can be suspended in a liquid medium, such as water, and applied by spraying. When the language "solid particulate mixable additive" is used in the specification and claims, the thermosetting composition may be in the form of a dry powder or in the form of a suspension. When the substrate is electrically conductive, the thermosetting composition is typically applied electrostatically. The application by electrostatic spray involves, in general, the extraction of the thermosetting composition from a fluidized bed and its propulsion through a corona field. The particles of the thermosetting composition are charged as they pass through the corona field and are attracted and deposited on the electrically conductive substrate, which is grounded. As the charged particles begin to accumulate, the substrate is isolated, thus limiting further deposition of particles. This isolation phenomenon typically limits the growth of the film of the deposited composition to a maximum of 3 to 6 mils (75 to 150 microns). Alternatively, when the substrate is not electrically conductive, for example as in the case of many plastic substrates, the substrate is typically preheated before application of the thermosetting composition. The preheated temperature of the substrate is equal to or higher than the melting point of the thermosetting composition, but lower than its curing temperature. With spray application on preheated substrates, film build-ups of the thermosettable composition can be achieved above 6 mil (150 microns), for example 10 to 20 mils (254 and 508 microns). Substrates which may be coated by the method of the present invention include, for example, ferrous substrates, aluminum substrates, plastic substrates, for example plastics based on sheet molding compounds, and wood.

Upon application to the substrate, the thermosetting composition is then coalesced to form a substantially continuous film. The coalescence of the applied composition is generally achieved by the application of heat at a temperature equal to or higher than the melting point of the composition, but less than its curing temperature. In the case of preheated substrates, the application and coalescence steps can be carried out essentially in a single step. The coalesced thermosetting composition is then cured by application of heat. As used herein and in the claims, "cured" means a three-dimensional crosslinking network formed by the formation of covalent bonds, for example, between the reactive functional groups of the coreactant and the epoxy groups of the polymer. The temperature at which the thermosetting composition of the present invention cures is variable and depends, in part, on the type and amount of the catalyst employed. Typically, the thermosetting composition has a coating temperature in the range of 130 ° C to 160 ° C, for example 140 ° C to 150 ° C. According to the present invention, there is further provided a coating composition composed of multiple components consisting of: (a) a base layer deposited from a pigmented film-forming composition and (b) a transparent outer layer applied on said base layer, wherein said transparent outer layer is deposited from a transparent film-forming thermosetting composition, consisting of a solid particulate mixable as previously described herein. Reference is made to the multi-component composite coating composition described herein as a colored-plus-clear coating composition. The pigmented film-forming composition from which the base layer is deposited can be any of the compositions useful in coating applications, particularly in automotive applications, in which colored-plus-clear coating compositions are widely used. The pigmented film-forming compositions conventionally contain a resinous binder and a pigment that acts as a colorant. Particularly useful resinous binders are acrylic polymers, polyesters, including alkalis, and polyurethanes. Resinous binders for the basecoat composition Pigmented film former can be materials based on organic solvents, such as those described in US Pat. No. 4,220,679, see column 2, line 24, column 4, line 40. In addition, water-based coating compositions, such as those described in US Pat. 4,403,003, 4,147,679 and 5,071,904, as a binder in the pigmented film-forming composition. The pigmented film forming basecoating composition is colored and may also contain metallic pigments. Examples of suitable pigments can be found in US Pat. 4,220,679, 4,403,003, 4,147,679 and 5,071,904. The components that may be present eventually in the pigmented film-forming basecoating composition are those that are well known in the art of surface coating formulation and include surfactants, flow control agents, thixotropic agents, fillers, gassing agents, organic cosolvents. , catalysts and other common auxiliary compounds. Examples of these eventual materials and of the suitable amounts are described in U.S. Pat. aforementioned 4,220,679, 4,403,003, 4,147,769 and 5,071,904.

The pigmented film-forming basecoating composition can be applied to the substrate by any of the conventional coating techniques, such as spraying, spraying, immersion or spill, but is more often applied by spraying. The usual spray techniques and equipment can be used for air spraying, airless spraying and electrostatic spraying, using manual or automatic methods. The pigmented film forming composition is applied in an amount sufficient to obtain a base layer with a film thickness typically of 0.1 to 5 mils (2.5 to 125 microns) and, preferably, 0.1 to 2 microns. milipulgadas (2,5 to 50 microns). After the deposition of the pigmented film-forming basecoating composition on the substrate and before the application of the transparent outer layer, the basecoat may be cured or alternatively dried. Upon drying the deposited base layer, the organic solvent and / or water is removed from the basecoat film by heating or air passing over its surface. Suitable drying conditions will depend on the particular basecoat composition used and the environmental humidity in the case of certain water-based compositions. In general, the drying of the deposited base layer is carried out over a period of 1 to 15 minutes and at a temperature of 21 ° C to 93 ° C. The transparent outer layer is applied to the base layer deposited by any of the methods by which it is known that the powder coatings are applied. Preferably, the transparent outer layer is applied by electrostatic spray application, as previously described herein. When the transparent outer layer is applied on a deposited base layer that has been dried, the two coatings can be co-cured to form the multi-component composite coating composition of the present invention. Both the base layer and the transparent layer are heated together to jointly cure the two layers. Typically, curing conditions of 130 ° C to 160 ° C are employed for a period of 20 to 30 minutes. The transparent outer layer typically has a thickness in the range of 0.5 to 6 mils (13 to 150 microns), for example 1 to 3 mils (25 to 75 microns). The present invention is described in more detail in the following examples, which are intended to be illustrative only, since numerous modifications and variations thereto will be obvious to those skilled in the art. Unless otherwise indicated, all parts and percentages are by weight. a »» .. s.ta < ! -.... -. i. s ^ iatSM ^ ¡? s ^ m. ~ ^ i ^? ~ r ^^ ~ i < ?? Synthesis Examples A-D Synthesis Examples A-D describe the preparation of epoxy-functional acrylic polymers used in the powder coating compositions of Examples 1-4. The epoxy-functional polymer of Example A is a comparative polymer prepared by non-living radical polymerization. The epoxy-functional polymers of Examples B-D are representative of polymers useful in the thermosetting coating compositions of the present invention. The physical properties of the polymers of Examples AD are summarized in Table 1. In the Synthesis Examples AD, the following abbreviations are used for the monomers: glycidyl methacrylate (MAG), isobutyl methacrylate (MAIB) and iso-15 bornyl methacrylate (MAIBo). The molar ratio of MAG to MAIB to MAIBo was 6: 4: 2 in each of the Synthesis Examples A-D. The block copolymer structures shown in each of Examples B-D are general formulas representative of block copolymers. Example A A comparative epoxy-functional polymer was prepared by standard radical polymerization, ie, uncontrolled or non-living, from the ingredients listed in Table 1. ^^ gj ^? w ^^^ »^^^^ ß < ¿^^^^^^ i ^^^ ^ blah A.

Table A Ingredients Parts by weight Load 1 Xylene 1 199.3 Load 2 MAG 2 183.3 MAIBo 1 164.4 MAIB 1 504.0 Load 3 Xylene 443, 1 Starter (a) 485.2 Load 4 Xylene 186.7 Load 5 Xylene 23.1 Initiator (a) 23.1 (a) Initiator of free t-amyl peroxyacetate LUPERSOL 555-M60 (60% by weight of odorless mineral spirits), from Elf-Atochem North America, Inc. Charge 1 was heated to reflux temperature at atmospheric pressure, under a blanket of nitrogen, in a 12-liter round bottom flask equipped with a rotary vane stirrer, a reflux condenser, a thermometer and a heating jacket coupled together in a loop feedback through a temperature controller, a nitrogen inlet opening and two addition openings. While in reflux conditions, Charges 2 and 3 were charged to the flask at the same time over a period of 3 hours and 3.5 hours, respectively. After the addition of Loads 2 and 3 had been completed, Charge 4 was divided into two equal parts and used to wash any residual material remaining in the addition funnels of Loads 2 and 3 and into the flask. Charge 5 was then charged into the flask, followed by two hours under reflux conditions. The contents of the flask were then distilled in vacuo. While still molten, the distilled contents of the flask were transferred to a suitable open hollow vessel and allowed to cool to room temperature and harden. Example B An epoxy-functional pentablock copolymer useful in the thermosetting compositions of the present invention was prepared by radical polymerization by atomic transfer from the ingredients listed in Table B. The epoxy-functional block copolymer of this example is diagrammatically summarized. as follows: (MAIB) 2- (MAG) 3- (MAIB) 2- (MAG) 3- (MAIBo) 2 Table B Ingredients Parts by weight Load 1 Toluene 158.8 Copper (II) bromide (b) 10.9 Copper powder (c) 44.5 2,2'-Bipyridilc > 15.31 Diethyl-2-bromo-2-methylmalonate 177.2 MAIB 198.8 Load 2 Toluene 158.8 MAG 298.2 Load 3 Toluene 158.8 MAIB 198.8 Load 4 Toluene 158, 9 MAG 298.2 Load 5 Tolueno 158.9 MAIBo 311.2 (b) Copper (II) bromide was in the form of flakes and was obtained from Aldrich Chemical Company. (c) The copper powder had an average particle size of 25 microns and a density of 1 gram / cm 3 and was commercially obtained from OMG Americas. _.- Sa¿J », YA, ^^^^ ^ ^^^^^ g ^^^^^^^^^ ^^ ^ ^ ^ ^ Charge 1 was heated and maintained at 90 ° C for 1 hour in a flask of 2 liters and 4 necks equipped with a stirring blade of motor-driven stainless steel, a water cooled condenser and a heating jacket and a thermometer connected through a temperature feedback control device. The contents of the flask were cooled to 70 ° C and Charge 2 was added over a period of 15 minutes, followed by 1 hour at 70 ° C. The contents of the flask were then heated to 90 ° C and Charge 3 was added over a period of 15 minutes, followed by 1 hour at 90 ° C. Charge 4 was then added over a period of 15 minutes after cooling the contents of the flask to 70 ° C, followed by 1 hour at 70 ° C. After heating the contents of the flask to 90 ° C, Charge 5 was added over a period of 15 minutes, followed by 2 hours at 90 ° C. Upon cooling to room temperature, the contents of the flask were filtered and then distilled in vacuo. While they were still molten, the distilled contents of the flask were transferred to a suitable open hollow vessel and allowed to cool to room temperature and harden. EXAMPLE C An epoxy-functional tetrablock copolymer useful in the thermosetting compositions of the present invention was prepared by radical polymerization by atomic transfer from the ingredients listed in Table C. The epoxy-functional block copolymer of this example is summarized diagrammatically as follows: (MAG) 3- (MAIB) 4- (MAG) 3- (MAIBo) 2 Table C Ingredients Parts by weight Load 1 Toluene 158.8 Copper (II) bromide (b) 10.9 Copper powder (c) 44.5 2,2 '- Bipyridyl 15.31 Diethyl -2-bromo-2 - methylmalonate 177.2 MAG 298.2 Load 2 Toluene 158.8 MAIB 398.2 Load 3 Toluene 158.8 MAG 298.2 Load 4 Toluene 158.9 MAIBo 311.2 Load 1 was heated to 70 ° C and maintained at that temperature. ^ ^ ^ ^ ^ ^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ liters and 4 necks equipped as described in Example B. The contents of the flask were heated to 90 ° C and Charge 2 was added over a period of 15 minutes, followed by 1.5 hours at 90 ° C. . After the contents of the flask were cooled to 70 ° C, Charge 3 was added over a period of 15 minutes, followed by 1 hour at 70 ° C. After heating the contents of the flask to 90 ° C, Charge 4 was added over a period of 15 minutes, followed by 2 hours at 90 ° C. The contents of the flask were cooled, filtered and distilled in vacuo as described in Example B.

Example D An epoxy-functional hexablock copolymer useful in the thermosetting compositions of the present invention was prepared by radical polymerization by atomic transfer with the ingredients listed in Table D. The epoxy-functional block copolymer of this example is diagrammatically summarized as follows : (MAG) 2- (MAIB) 2- (MAG) 2- (MAIB) 2- (MAG) 2- (MAIBo) 2 Table D Ingredients Parts by weight Load 1 Toluene 127.0 Copper (II) bromide (b) 10.9 Copper powder (c) 44.5 2,2 '- Bipyridyl Diethyl-2-bromo-2-methylmalonate MAG Load 2 Tolueno 127 0 MAIB 199 1 Load 3 Tolueno 127 0 MAG 198, 8 Load 4 Tolueno 127, 0 MAIB 199, 1 Load 5 Tolueno 127, 0 MAG 198, 8 Load 6 Tolueno 127, 0 MAIBo 311, 2 Charge 1 was heated and maintained at 70 ° C for one hour in a 2-liter, 4-necked flask equipped as shown. described in Example B. The contents of the flask at 90 ° C and Charge 2 was added over a period of 15 minutes, followed by 1 hour at 90 ° C. After the contents of the flask were cooled to 70 ° C, Charge 3 was added over 15 minutes and then maintained at 70 ° C for 1 hour. After heating the contents of the flask to 90 ° C, Charge 4 was added over 15 minutes and then maintained at 90 ° C for 1 hour. The contents of the flask were cooled to 70 ° C and Charge 5 was added over 15 minutes, followed by 1 hour at 70 ° C. After heating the contents of the flask to 90 ° C, Charge 6 was added over 15 minutes, followed by 2 hours at 90 ° C. The contents of the flask were cooled, filtered and distilled in vacuo as described in Example B.

TABLE 1 PHYSICAL DATA OF THE POLYMERS OF EXEMPLIFICATION EXAMPLES AD EXAMPLE EXAMPLE EXAMPLE A B Y P LO B CD M n (d) 1369 2448 2087 2300 Mp 2873 3538 2803 3482 Mz 4588 4689 3477 4642 Mpi 2927 3499 2986 3622 IPD (e) 2.1 1.4 1.3 1.5 Medium point Pg (° C) (f) 25.3 41.3 43.3 43.2 Fused viscosity at 129 655 689 467 125 ° C (poise) (g) Viscosity in fusion at 90 439 461 323 130 ° C (poise) Melt viscosity at 64 286 296 213 135 ° C (poise) Melt viscosity at 48 190 194 146 140 ° C (poise) Melt viscosity at 36 131 133 103 145 ° C (poise) Melt viscosity at 28 87 87 71 150 ° C (poise) Epoxy equivalent weight 327 370 380 390 (h) 99.6 99.6 99.5 99.6 Percentage by weight of solids (i) (d) The molecular weight data were obtained by means of - ^?. ^ g. Ifr-heSt «g =» ^^ faith «^^^ a? Áí ^^^^^^^^^^ & ^^^^^^^^^^ sf of gel permeation chromatography using patterns of polystyrene. The abbreviations are summarized as follows: number average molecular weight (Mn), weight average molecular weight (Mp), average molecular weight z (Mz) and peak molecular weight (Mpi). (e) polydispersity index (IPD) = (Mp / Mn). (f) The midpoints of the glass transition temperature (Tg) were determined by means of differential scanning calorimetry. The polymer samples underwent a stress release cycle, followed by heating at a rate of 10 ° C / minute. (g) Melt viscosities at 125 ° C to 150 ° C were determined using a Brookfield CAP 2000 High Temperature Viscometer. (h) Epoxy equivalent weights (polymer grams / epoxy equivalent) were determined by titration using a solution of 0.1 Normal perchloric acid, (i) The percentage by weight of solids, based on the total weight, was determined from samples of 0.2 grams at 110 ° C / 1 hour. Examples of powder coating 1-4 Examples 2-4 of powder coating are representative of thermosetting coating compositions according to the present invention, while Example 1 of powder coating is a comparative example. The powder coating compositions were prepared with the ingredients listed in Table 2. (j) Dodecanedioic acid. (k) An acrylic flow additive with 100 percent by weight solids prepared thanks to the polymerization of radi- : & ^ Or any tfMM ^ & s free limes nonliving methacrylate N, N-dimethylaminoethyl acrylate, isobutyl acrylate and 2-ethylhexyl. (1) WAX C MICRO POWDER additive, marketed by Hoechst-Celanese, who describe it as ethylenebysterolamide. (m) TINUVIN 444 ultraviolet light stabilizer, marketed by Ciba-Geigy Corp., who described it as [bis (methyl-2, 2,6,6-6-tetramethyl-4-piperidinyl)] 2-tert-butyl dipropionate. 2- (4-hydroxy-3,5-di-tert-butylbenzyl). (n) Ultraviolet light stabilizer CGL-1545, commercialized by Ciba-Geigy Corp., who described it as 2- [4- (2-hydroxy-3- (2-ethylhexyloxy) -propyl) oxy] -2-hydroxyphenyl) 4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine. (o) Anti-yellowing agent GCA-1, marketed by Sanko Chemical Corp. (p) ARMEEN M2C amine catalyst, commercialized by Akzo-Nobel Corp., who describe it as methyldicocoamine. The ingredients listed in Table 2 were premixed in a Henshel dry mixer for 30 to 60 seconds. The melt premixes were then mixed in a corotatory double-screw extruder Werner & Pfleider at a helix speed of 450 revolutions per minute, to form a molten extrudate with a temperature of 100 ° C to 125 ° C. The molten extrudate was pressed to form a The thin film was cooled and solidified on a set of ice-cold stainless steel rollers, broken into smaller pieces, milled and classified to form transparent thermosetting powder coating compositions with an average size of particle from 17 to 27 microns. The clear powder coating compositions of Examples 1-4 were applied by electrostatic sputtering on test panel substrates and cured at 145 ° C for 30 minutes. The substrates of the test panels had previo been coated with a cured black electrocoat primer marketed by PPG Industries, Inc. as an ED-5051 electroimprimer. The applied powder coating compositions had cured film thicknesses of 66 to 74 microns. The appearance of the powder-coated test panels was evaluated and the results are summarized in Table 3. ^^^^^^^^^^^^^^ g ^^^^^^^^^^ ÍB ^^^^^^^^^^^ (q) Brightness values at 20 ° were obtained using a BYK Gardner Optical Brightness-Brightness Meter according to the method of operation suggested by the manufacturer. (r) Long wave values were obtained using a BYK Wave-sea Plus instrument according to the method of operation suggested by the manufacturer. Longer wavelength values of less magnitude are indicative of smoother coatings in appearance. (s) The voltage values were obtained using a BYW Wavescan Plus instrument according to the method of operation suggested by the manufacturer. The voltage values of greater magnitude are indicative of coatings with more lysis in terms of appearance. The results summarized in Table 3 show that the compositions of thermosetting powder coating according to the present invention, ie, Examples 2, 3 and 4, provide coatings having a similar coatings obtained with the comparative compositions 5 aspect erative, ie, Example 1. in addition, it was observed that the compositions of powder coating of Examples 2, 3 and 4 had good physical stability at room temperature, that is, remaining free flow and showed no signs of sintering or agglutination after 24 hours. However, it was observed that the comparative powder coating composition of Example 1 had very poor physical stability at room temperature (sintering, binding and becoming almost solid in less than 24 hours). The present invention has been described in relation to specific aspects of particular embodiments thereof. It is not intended to consider such details as limitations of the scope of the invention, except to the extent and extent to which they are included in the appended claims. á a i &fc- »^ ^ tó l ^^^^^ íjS? g ^^^^^ É ^^^^^ £ ggí ^^^^^

Claims (69)

1. Claims 1. A thermosetting composition consisting of a solid particulate mixture that can be activated by: (a) an epoxy-functional block copolymer prepared by radical polymerization by atomic transfer initiated in the presence of an initiator having at least one radical-transferable group and wherein said epoxy polymer -functional contains at least one of the following polymer chain structures: f - [[(M) p- (G) q] x and f - [[(G) q- (M) p] x- where f is , or derived from, a residue of the free initiator of the radical-transferable group, M is a residue free of oxirane functionality of at least one ethylenically unsaturated radical-polymerizable monomer, G is an oxirane-functional residue of at least one polymerizable ethylenically unsaturated monomer by radicals, p and q represent number of waste media that appear in a block of waste in each polymer chain structure and p, q and x are each individually selected for each structure Such a process is such that said functional epoxy polymer has a number average molecular weight of at least 250, and (b) a coreactant having functional groups capable of reacting with the epoxy groups of (a).
2. 2. The composition of claim 1, wherein said coreactant is a carboxylic acid functional coreactant containing from 4 to 20 carbon atoms. The composition of claim 2, wherein said carboxylic acid functional co-reactant is selected from the group consisting of dodecanedioic acid, azelaic acid, adipic acid, 1,6-hexanedioic acid, succinic acid, pimelic acid, sebacic acid, maleic acid , citric acid, itaconic acid, aconitic acid and their mixtures. 4. The composition of claim 1, wherein said co-reactant is represented by the following general formula: where R is the residue of a polyol, E is a divalent linking group having from 2 to 10 carbon atoms and n is an integer from 2 to 10. 5. The composition of claim 4, wherein said polyol from which R is derived is selected from the group consisting of ethylene glycol, di (ethylene glycol), trimethylolethane, trimethylolpropane, pentaerythritol, ditrimethylolpropane and di-pentaerythritol; E is selected from the group consisting of 1,2-cyclohexylene and 4-methyl-1,2-cyclohexylene, and n is an integer from 2 to 6. The composition of claim 1, wherein said epoxy-functional polymer is selected from the group consisting of linear polymers, branched polymers, hyperbranched polymers, star polymers, graft polymers and their mixtures. The composition of claim 1, wherein said epoxy-functional polymer has a number average molecular weight of 500 to 16,000 and a polydispersity index of less than 2.0. The composition of claim 1, wherein said initiator is selected from the group consisting of linear or branched aliphatic compounds, cycloaliphatic compounds, aromatic compounds, polycyclic aromatic compounds, heterocyclic compounds, sulfonyl compounds, sulfenyl compounds, esters of carboxylic acids, polymeric compounds and mixtures thereof, each having at least one halide transferable by radicals 9. The composition of claim 8, wherein said initiator is selected from the group consisting of halo-methane, methylene dihalide, haloform, tetrahalide carbonate, l-halo-2, 3-epoxypropane, methanesulfonyl halide, p-toluenesulfonyl halide, methanesulfenyl halide, p-toluenesulfenyl halide, 1-phenylethyl halide, Ci-Cß alkyl ester of acid 2-halocarboxylic acid C? -C6, p-halomethylstyrene, monohexakis (-haloalkyl C? -C6) benzene, diethyl-2-halo-2-methyl malonate, e-2-bromoisobutyrate Linden and its mixtures. The composition of claim 1, wherein said epoxy-functional polymer has an epoxy equivalent weight of 128 to 10,000 grams / equivalent. 11. The composition of claim 1, wherein M is derived from at least one of vinyl monomers, allylic monomers and olefins. 12. The composition of claim 11, wherein M is derived from at least one of alkyl (meth) acrylates having from 1 to 20 carbon atoms in the alkyl group, vinyl aromatic monomers, vinyl halides, esters. vinyls of carboxylic acids and olefins, and G is derived from at least one of glycidyl (meth) acrylate, 3,4- (meth) acrylate ^^^^^^^^^^^^^^^^^^^^^^ ..-.ACE. ? ¡. ^. ^ «,. ,? KS j ^ S ^^^ a ^ M ^^^^ Aai sK ^? J ^ L? A ^ i epoxycyclohexylmethyl (meth) acrylate 2- (3,4-epoxycyclohexyl) ethyl, and allyl glycidyl ether. The composition of claim 1, wherein said epoxy functional polymer has at least one of the following polymer chain structures: f - [[(M) P- (G) q] x- (M) rT] 2 and f- [[(G) q- (M) P] X- (G) ST] 2 where f is, or derives from, the residue of said free initiator from said radical-transferable group; T is, or derives from, said group transferable by radicals of said initiator; x is independently from 1 to 100 for each structure; p and q are each independently within the range of 0 to 100 for each x-segment and for each structure, the sum of p and q being at least 1 for each x-segment and q being at least 1 for at least one x-segment; r and s are each independently for each structure in the range of 0 to 100; z is independently for each structure at least 1, and said epoxy-functional polymer has a polydispersity index of less than 2.0. The composition of claim 13, wherein said epoxy functional polymer has a number average molecular weight of 500 to 16,000 and a polydispersity index of less than 1.8. The composition of claim 13, wherein p is independently selected for each structure in the range of 1 to 20 and q is independently selected for each structure in the range of 1 to 20. 16. The composition of claim 13, wherein x is independently selected for each structure in the range of 1 to 50. 17. The composition of claim 15, wherein T is halide. 18. The composition of claim 17, wherein T derives from a post-dehalogenation reaction. 19. The composition of claim 18, wherein said posthalogenation post-reaction consists in contacting said epoxy-functional polymer with an ethylenically unsaturated, radically polymerizable limited compound. The composition of claim 19, wherein said ethylenically unsaturated radical polymerizable compound is selected from the group consisting of 1, 1-dimethylethylene, 1, 1-diphenylethylene, isopropenyl acetate, alpha-methylstyrene, 1, 1- dialkoxyolefin and combinations of these. 21. The composition of claim 1, wherein the ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^ g ^^^^^^^^^ gfe ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ g ^^^^^^^^^ gfe ^^^^^^^^^^^^^^^^^^^^^^^^^^^ The equivalent amount of epoxy equivalents in said epoxy functional polymer (a) with respect to the equivalents of reactive functional groups in said coreactant (b) is from 0.5: 1 to 2: 1. 22. The composition of claim 1, wherein said epoxy-functional polymer (a) is present in said thermosetting composition in amounts of 50 to 90 percent by weight, based on the total weight of the resin solids, and said co-reactant (b) is present in said thermosetting composition in amounts of 10 to 50 percent by weight, based on the total weight of the resin solids. 23. A method of coating a substrate, comprising: 15 (a) applying to said substrate a thermosetting composition, (b) coalescing said thermosetting composition to form a substantially continuous film, and (c) curing said thermosetting composition applied 20 heat-treatment, wherein said thermosetting composition consists of a solid particulate mixture that can be coactivated by: (i) a functional epoxy block copolymer prepared by radical polymerization by atomic transfer; t ^^ g ^^^^^^^^^^^^^^^^^^^^^^ & ^^^^^^^^^^ te ^^^^^^^^^^ ^^^^^^^^ teafej ^^^^^ c ^^^^^^ fat ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ initiator having at least one group transferable by radicals and wherein said functional epoxy polymer contains at least one of the following polymer chain structures: 5 f - [[(M) p- (G) q] x- and f- [ [(G) q- (M) P] X- where f is, or derives from, a residue of the free initiator of the radical-transferable group, M is a free residue of Oxirane functionality of at least one radically polymerizable ethylenically unsaturated monomer, G is an oxirane functional residue of at least one ethylenically unsaturated radical polymerizable monomer, and p and q represent average numbers of residues that appear in a residence block 15 duos in each polymer chain structure and p, q and x are each individually selected for each structure such that said epoxy-functional polymer has a number-average molecular weight of at least 250, and (ii) a co-reactant having functional groups 20 reagents with the epoxy groups of (i). 24. The method of claim 23, wherein said coreactant is a carboxylic acid functional coreactant containing from 4 to 20 carbon atoms. ^^^^^^^^ 7 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^ ^ ^^^^^^^^^^^^^^^^^^^ 25. The method of claim 24, wherein said carboxylic acid functional co-reactant is selected from the group consisting of dodecanedioic acid, azelaic acid, adipic acid, 1,6-hexanedioic acid, succinic acid, pimelic acid, sebacic acid, maleic acid, citric acid, itaconic acid, aconitic acid and their mixtures. 26. The method of claim 23, wherein said coreactant is represented by the following general formula: Where R is the residue of a polyol, E is a divalent linking group having from 2 to 10 carbon atoms and n is an integer from 2 to 10. The method of claim 26, wherein said po The liol from which R is derived is selected from the group consisting of ethylene glycol, di (ethylene glycol), trimethylolethane, trimethylolpropane, pentaerythritol, ditrimethylolpropane and dipentaerythritol; E is selected from the group consisting of 1,2-cyclohexylene and 4-methyl-1,2-cyclohexylene, and n is a 20 whole number from 2 to 6. j ^^^^^^^^^^^^^^^^^^^^^^ gi ^^^^^^^^^^^^^^^^^^^^^^ ^^ g ^^^^^^^^^^^^^^^^ * ^^^^^^^^^^^ 28. The method of claim 23, wherein said epoxy functional polymer is selected from the group consisting of linear polymers, branched polymers, hyperbranched polymers, star polymers, graft polymers and 5 their mixtures. 29. The method of claim 23, wherein said epoxy functional polymer has a number average molecular weight of 500 to 16,000 and a polydispersity index of less than 2.0. 30. The method of claim 23, wherein said initiator is selected from the group consisting of linear or branched aliphatic compounds, cycloaliphatic compounds, aromatic compounds, polycyclic aromatic compounds, heterocyclic compounds, sulfonyl compounds, sulfenyl compounds, esters of carboxylic acids, polymeric compounds and mixtures thereof, each having at least one halide transferable by radicals. 31. The method of claim 30, wherein said initiator is selected from the group consisting of halomethane, methylene dihalide, haloform, carbon tetrahalide, l-halo-2, 3-epoxypropane, methanesulfonyl halide, p-toluenesulfonyl, methanesulfenyl halide, p-toluenesulfenyl halide, 1-phenylethyl halide, alkyl ester : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ halocarboxylic Ci-Cß, p-halomethylstyrene, monohexakis (-haloalkyl Cx-Cß) benzene, diethyl-2-halo-2-methyl malonate, ethyl 2-bromoisobutyrate and their mixtures. 32. The method of claim 23, wherein said epoxy-functional polymer has an epoxy equivalent weight of 128 to 10. 000 grams / equivalent. The method of claim 23, wherein M is derived from at least one of vinyl monomers, allylic monomers and olefins. 34. The method of claim 33, wherein M is derived from at least one of alkyl (meth) acrylates having from 1 to 20 carbon atoms in the alkyl group, aromatic vinyl monomers, vinyl halides, vinyl acid esters carboxylic and olefin, and G derived from at least one of glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 2- (3,4-epoxycyclohexyl) ethyl (meth) acrylate, and allyl glycidyl ether . 35. The method of claim 23, wherein said epoxy-functional polymer has at least one of the following polymer chain structures: f- [[(M) p- (G) q] x- (M) rT] 2 f- [[(G) q- (M) p] x- (G) s-T] where f is, or derives from, the residue of said free initiator from said radical-transferable group; T is, or derives from, said group transferable by radicals of said initiator; x is independently from 1 to 100 for each structure; p and q are each independently within the range of 0 to 100 for each x-segment and for each structure, the sum of p and q being at least 1 for each x-segment and q being at least 1 for at least one x-segment; r and s are each independently for each structure in the range of 0 to 100; z is independently for each structure at least 1, and said functional epoxy polymer has a polydispersity index of less than 2.0. 36. The method of claim 35, wherein said epoxy functional polymer has a number average molecular weight of 500 to 16,000 and a polydispersity index of less than 1.8. 37. The method of claim 35, wherein p is independently selected for each structure in the range of 1 to 20 and q is independently selected for each structure in the range of 1 to 20. 38. The method of claim 35, wherein x is independently selected for each structure in the range of 1 to 50. j ^ >e ^ g 39. The method of claim 35, wherein T is halide. 40. The method of claim 39, wherein T derives from a post-dehalogenation reaction. 41. The method of claim 40, wherein said post-reaction of dehalogenation consists in contacting said epoxy-functional polymer with a radically polymerizable ethylenically unsaturated compound limited. 42. The method of claim 41, wherein said limited radically polymerizable ethylenically unsaturated post is selected from the group consisting of 1,1-dimethylethylene, 1,1-diphenylethylene, isopropenyl acetate, alpha-methylstyrene, 1, 1- dialkoxyolefin and combinations of these. 43. The method of claim 23, wherein the equivalent ratio of epoxy equivalents in said epoxy functional polymer (i) to equivalents of reactive functional groups in said coreactant (ii) is from 0.5: 1 to 2. :1. 44. The method of claim 23, wherein said epoxy-functional polymer (i) is present in said thermosetting composition in amounts of 50 to 90 percent by weight, based on the total weight of the resin solids, and saying coreactant (ii) is present in said thermosetting composition in amounts of 10 to 50 percent by weight, based on the total weight of the resin solids. 45. A substrate coated by the method of claim 23. 46. A multi-component composite coating composition comprising: (a) a base layer deposited from a pigmented film-forming composition and (b) a layer transparent outer layer applied on said base layer, wherein said transparent outer layer is deposited from a transparent film-forming thermosetting composition, consisting of a solid particulate mixture that can be coactivated by: (i) an epoxy-functional block copolymer prepared by radical polymerization by atomic transfer initiated in the presence of an initiator having at least one group transferable by radicals and wherein said epoxy-functional polymer contains at least one of the following polymer chain structures: f- [[(M) p- (G ) q] x- f - [[(G) q- (M) p] where f is, or derives from, a residue of the free initiator from the radical transferrable group, M is a residual of oxirane functionality of at least one ethylenically unsaturated radical polymerizable monomer, G is an oxirane functional residue of at least one ethylenically unsaturated radical polymerizable monomer, and p and q represent average numbers of residues that appear in a block of residues in each structure of polymer chain and p, q and x are each individually selected for each structure such that said epoxy functional polymer has a number average molecular weight of at least 250, and (ii) a coreactant having functional groups capable of reacting with the epoxy groups of (i). 47. The multi-component component coating composition of claim 46, wherein said coreactant is a carboxylic acid functional coreactant containing from 4 to 20 carbon atoms. 48. The multi-component composite coating composition of claim 47, wherein said carboxylic acid functional reactant is selected from the group consisting of dodecanedioic acid, azelaic acid, adipic acid, 1,6-hexanedioacetic acid, acid succinic, pimelic acid, sebacic acid, maleic acid, citric acid, acid Itaconic, aconitic acid and its mixtures. 49. The multi-component composite coating composition of claim 46, wherein said co-reactant is represented by the following general formula: where R is the residue of a polyol, E is a divalent linking group having 2 to 10 carbon atoms and n is an integer from 2 to 10. 50. The coating composition composed of multiple components of claim 49, wherein said polyol from which R is derived is selected from the group consisting of ethylene glycol, di (ethylene glycol), trimethylolethane, trimethylolpropane, pentaeptritol, ditrimethylolpropane and dipentaerythritol; E is selected from the group consisting of 1,2-cyclohexylene and 4-methyl-l, 2-cyclohexylene, and n is an integer from 2 to 6. 51. The coating composition composed of multiple components of claim 46, wherein said epoxy-functional polymer is selected from the group consisting ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ linear polymers, branched polymers, hydroxyethyl perramificados polymers, polymers star polymers of grafting and their mixtures. 52. The coating composition composed of multi feet components of claim 46, wherein said epoxy -functional polymer has a number average molecular weight of 500 to 16,000 and a polydispersity of less than 2.0. 53. The multi-component composite coating composition of claim 46, wherein said initiator is selected from the group consisting of linear or branched aliphatic compounds, cycloaliphatic compounds, aromatic compounds, polycyclic aromatic compounds, heterocyclic compounds, sulfonyl compounds, sulfenyl compounds, esters of carboxylic acids, polymeric compounds and mixtures thereof, each having at least one halide transferable by radicals. 54. The multi-component composite coating composition of claim 53, wherein said initiator is selected from the group consisting of halomethane, methylene dihalide, haloform, carbon tetrahalide, 1- halo-2,3-epoxypropane, methanesulfonyl halide , p-toluenesulfonyl halide, methanesulfenyl halide, p-toluenesulfenyl halide, 1-phenylethyl halide, C 1 -C alkyl ester C6 of 2-halocarboxylic acid C? -C6, p-halomethylstyrene, mo-nohexakis (-haloalkyl C? -C6) benzene, diethyl-2-halo-2-methyl malonate, ethyl 2-bromoisobutyrate and their mixtures. 55. The composite composition of multiple component feet of claim 46, wherein said epoxy functional polymer has an epoxy equivalent weight of 128 to 10,000 grams / equivalent. 56. The multi-component composite coating composition of claim 46, wherein M derives from at least one among vinyl monomers, allylic monomers and olefins. 57. The coating composition composed of multiple components of claim 56, wherein M is derived from at least one of (meth) acrylates having 1 to 20 carbon atoms in the alkyl group, vinyl aromatic monomers, halides vinyl, vinyl esters of carboxylic acids and olefins, and G derived from at least one of glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 2- (3,4-epoxycyclohexyl) (meth) acrylate ethyl, and allyl glycidyl ether. 58. The multi-component composite coating composition of claim 46, wherein said epoxy-functional polymer has at least one of the following ^^^] ¡__ ^ _ ^^ u ^^^^^^^^ f ^^ 'yiY ^^ S Y A, ^ to ^ .. ^ i ^ ^ ^ ^ ^ ^ polymer chain structures: f- [[(M) p- (G) q] x- (M) rT] 2 and f - [[(G) q- (M) p] x- (G) sT] 2 Where f is, or derives from, the residue of said free initiator from said radical-transferable group; T is, or derives from, said group transferable by radicals of said initiator; x is independently from 1 to 100 for each structure; p and q are each independently within the range of 0 to 100 10 for each x-segment and for each structure, the sum of p and q being at least 1 for each x-segment and q being at least 1 for at least one x-segment; r and s are each independently for each structure in the range of 0 to 100; z is independently for each structure at least 1, and said epoxy-functional polymer has a polydispersity index of less than 2.0. 59. The multi-component composite coating composition of claim 58, wherein said epoxy-functional polymer has a number average molecular weight of 20,500 to 16,000 and a polydispersity index of less than 1.8. 60. The multi-component composite coating composition of claim 58, wherein p is independently selected for each structure in the range of ^^^^^^^^^^^^^^^ jB ^ WWfcMj ^^ & ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^ te ^^^^^^^^^^^^ a, ^^^^ - ,, 1 to 20 and q is independently selected for each structure in the range of 1 to 20. 61. The coating composition Composite of multiple components of claim 58, wherein x is independently selected for each structure in the range of 1 to 50. 62. The multi-component composite coating composition of claim 58, wherein T is halide. 63. The composite coating composition of multiple 10-component components of claim 62, wherein T is derived from a post-dehalogenation reaction. 64. The multi-component composite coating composition of claim 63, wherein said dehalogenation post reaction comprises contacting said functional epoxy polymer with an ethylenically unsaturated, radically polymerizable, limited compound. 65. The multi-component composite coating composition of claim 64, wherein said ethylenically unsaturated compound polymerizable by 20 radicals is selected from the group consisting of 1,1-dimethylethylene, 1,1-diphenylethylene, isopropenyl acetate, alpha-methylstyrene, 1,1-dialkoxyolefin and combinations thereof. 66. The multi-component composite coating composition of claim 46, wherein the equivalent ratio of epoxy equivalents in said epoxy-functional polymer (i) to equivalents of reactive functional groups in said co-reactant (ii) is 0 , 5: 1 to 2: 1. 67. The multi-component composite coating composition of claim 46, wherein said epoxy-functional polymer (i) is present in said thermosetting composition in amounts of 50 to 90 percent by weight, based on the total weight of the composition. the resin solids, and said co-reactant (ii) is present in said thermosetting composition in amounts of 10 to 50 percent by weight, based on the total weight of the resin solids. 68. A substrate having said multi-component coating composition of claim 46 deposited thereon. 69. A substrate having said multi-component coating composition of claim 58 deposited thereon.