Coatings and primers

Abstract

A method for coating a substrate containing at least one chemical group is provided by contacting the substrate surface with a compound containing at least one carbon-carbon double bond or a mixture of a first monomer M1 and a second monomer M2. Then, at least a portion of the formed complex is exposed to actinic radiation, which initiates the reaction between the photoactive group and the carbon-carbon double bond to form a covalent bond, and the wavelength of the actinic radiation is adapted to be absorbed by the photoactive group. This method is tolerant to a large extent to the suppression of impurities in the substrate surface. Greater uniformity of the modulus of elasticity across the substrate and added layers can be achieved. Adding an additional topcoat results in a surface with increased hardness and improved scratch resistance. Applying a topsheet improves abrasion resistance.

Description

[Technical Field]

[0001] The present invention generally relates to coatings or primers. Further coatings, and optionally topcoats, can be applied on top of the coatings. Thin coatings are created by bringing a substrate surface into contact with a compound or mixture, and then initiating a reaction that forms covalent bonds by irradiating the photoreactive groups on the substrate surface, or reactive chemical groups in a liquid mixture that react with the photoreactive chemical groups on the surface. [Background technology]

[0002] In many industrial processes, it is desirable to deposit a dry, thin film with residual reactive groups onto a substrate. This film is then used in a later stage to adhere another object, such as a coating or film, to the first substrate.

[0003] In the polymer film industry, rollers are used to apply tension to the film fabric, and because the rollers are in contact with both sides of the film, liquids, partially liquids, or highly viscous films pose a risk of contaminating the rollers and transferring dust and other undesirable surface defects. In other cases, it is preferable to activate the surface of one part and use the activated surface of the other part for transport between them, which is much easier if the surface of the activated substrate is dry.

[0004] In multilayer UV-curing coating systems using the latest technology, a standard technique for ensuring interlayer adhesion is to intentionally under-cure the first lacquer. The next lacquer layer then reacts with the under-cured top layer of the previous layer, thereby ensuring good adhesion. In acrylic systems, under-curing is typically achieved via oxygen inhibition, which tends to leave a thin, less reactive layer on top of the lacquer. When the next layer is applied, the oxygen becomes ineffective, and the oxygen-inhibited layer reacts with the bottom of the subsequent layer, resulting in complete interlayer adhesion. If carefully executed during preparation, it is possible to have drying of the contact film with a sufficient amount of residual reactive groups to obtain good bonding to the next layer.

[0005] In very thin coating layers, oxygen diffusion from the atmosphere generally affects the top 1-3 microns of the coating. Therefore, it is extremely difficult to control bulk polymerization and film formation while suppressing oxygen in the submicron region, making oxygen suppression methods impractical.

[0006] Japanese Patent No. 5568311 discloses nanoparticles that adhere to a substrate via polymerizable groups on the nanoparticles. The nanoparticles may be in the form of additives to a monomer mixture, or in the form of an emulsion or solution, and are attached to the substrate using chemical radiation. The nanoparticles thus adhered can be used as is or as adhesion promoters for subsequent layers.

[0007] U.S. Patent No. 7,455,891 discloses a method for applying a thin primer layer to a corona, plasma, or flame-activated surface. The primer is in the form of a solution, emulsion, or suspension and is dried before a chemical beam or electromagnetic wave is used to react the primer with the surface. The primer can form a final coating or serve as the base for a second coating that forms a final surface.

[0008] Japanese Patent No. 2006510774 discloses a method for bonding a film to a corona, low-temperature plasma, flame, or strongly radiation-treated organic or inorganic surface using a primer containing an initiator or initiator monomer blend in the form of a molten, suspension, solution, or emulsion. The method includes a first heating step for forming an adhesive layer and an optionally chemical beam step. A further coating is applied and reacts with the primer layer to form a final article.

[0009] U.S. Patent No. 6,733,847 discloses a method for depositing a thin primer layer onto a corona, plasma, or flame-activated surface. The primer comprises a monomer having a hydrogen-donating group and an ethylenically unsaturated group. The layer spontaneously adheres to the surface via the hydrogen-donating group. The layer can then be reacted with a coating composition that can react with the ethylenically unsaturated group to form a final coated object.

[0010] Japanese Patent No. 2014063762 discloses a chemically wire-cured silicone aqueous dispersion primer formulation for polymer resin surfaces.

[0011] U.S. Patent No. 4,495,020 discloses an isocyanate-containing primer composition for providing a surface suitable for bonding polyester plastic articles to other or similar type plastic articles.

[0012] U.S. Patent No. 9,692,412 discloses coating formulations for plastics and transparent inorganic substrates, which include polyacrylates, diisocyanates, polyether polyols, and photopolymerizable and hydroxyl group-containing compounds.

[0013] U.S. Patent Application Publication No. 2003 / 01502767 discloses a primer composition comprising a polymer reacted with, for example, maleic anhydride.

[0014] European Patent No. 0574352 discloses a process for modifying the surface properties of a pre-formed polymer substrate and imparting properties altered by graft polymerization to the substrate, comprising placing the polymer substrate in a plasma to form free radicals on the substrate, contacting the substrate having free radicals with oxygen to form hydroperoxy groups on the surface of the substrate, and graft polymerizing an ethylenically unsaturated monomer and a crosslinking agent onto the surface of the polymer substrate.

[0015] U.S. Patent Application Publication No. 2017 / 0290955 discloses a medical device for implantation in the body, comprising a polymer substrate and a layer of poly(vinylpyrrolidone-alt-maleic anhydride) formed on the surface of the polymer substrate, wherein the polymer chains of poly(vinylpyrrolidone-alt-maleic anhydride) intertwine with the polymer substrate to form a lubricating hydrophilic layer.

[0016] U.S. Patent No. 6,582,754 discloses a method for coating a material surface, comprising: (a) covalently bonding a compound containing an ethylenically unsaturated double bond to the material surface; (b) polymerizing a monomer containing a reactive group or a crosslinkable group on the surface to provide a primary polymer coating containing a reactive group or a crosslinkable group; (c) if the monomer in step (b) contains a reactive group, reacting the reactive group of the primary coating with a further compound containing an ethylenically unsaturated double bond to graft polymerize a hydrophilic monomer and optionally a comonomer having a crosslinkable group onto the primary coating obtained according to step (b); and (d) if a crosslinkable group is present in step (b) or (c), initiating the crosslinking of the group.

[0017] Chinese Patent No. 104945983 and Chinese Patent No. 104945985 disclose monofunctional methacrylates that form polymer chains with maleic anhydride. In the first step, a polyanhydride is formed that will react with epoxy in a subsequent step. Thus, the anhydride reacts with the polyanhydride. Since monofunctional methacrylates are used, no crosslinking network is formed. The introduction discloses that the material was prepared by first synthesizing an acrylic resin having pendant anhydride groups, then subjecting it to a modified epoxy resin and an epoxy-modified acrylic resin, thereby preparing a one-component epoxy-modified acrylic coating with excellent adhesion, good hardness, and gloss.

[0018] U.S. Patent No. 2019 / 263072 discloses a method for joining composite substrates, wherein a curable surface treatment layer is applied to a curable composite substrate and subsequently co-cured. After co-curing, the composite substrate is fully cured, but the surface treatment layer remains partially cured. The surface treatment layer may be a resin film or a peel ply made of resin-impregnated cloth. If a peel ply is used, the peel ply is peeled off after co-curing, leaving a thin film of partially cured resin. Subsequent dry physical surface treatment, such as plasma, is performed to physically modify the surface of the surface treatment layer. After the dry physical surface treatment, the composite substrate has a chemically active bondable surface that is adhesively bonded to another composite substrate to form a covalent bond structure.

[0019] U.S. Patent No. 5,254,395 discloses a coating system for forming a highly abrasion-resistant, chemical-resistant, and impact-resistant protective finish for a substrate. The coating system is based on using two coatings having different properties but excellent adhesion to each other. The outermost or surface coating layer is a highly crosslinked rigid polymer that adheres to a base coating layer beneath a compatible soft polymer. The outer rigid polymer preferably comprises a highly crosslinked acrylic copolymer derived from at least 40% by weight of a polyfunctional aliphatic acrylate monomer having three or more functional groups, while the underlying softer polymer preferably comprises a crosslinked aliphatic urethane acrylate copolymer and a polyfunctional aliphatic acrylate monomer having three or more functional groups.

[0020] British Patent No. 2107723 discloses a process for treating a substrate curable by exposure to chemical radiation, the process comprising preparing a solution comprising water, 0.1 to 75% by weight of acrylic acid and 0.01 to 5% by weight of a suitable surfactant, depositing a layer of the solution onto the substrate, and exposing the treated substrate to chemical radiation.

[0021] U.S. Patent No. 8,227,050 discloses a UV-curable coating composition comprising one or more monomers, one or more polyfunctional oligomers, one or more pigments, one or more photoinitiators, and a volatile organic solvent.

[0022] International Publication No. 2012 / 042059 discloses a method for producing a thiol-ene polymer article, comprising the steps of: a) reacting a compound containing at least two thiol groups with a compound containing at least two carbon-carbon double bonds in a non-stoichiometric ratio to obtain a first intermediate article, wherein the first intermediate article contains at least one unreacted group selected from unreacted thiol groups and unreacted carbon-carbon double bonds; and b) contacting the first intermediate article with a second article, wherein the surface of the second article contains at least partially reactive groups; and reacting at least some of the unreacted groups on the first intermediate article with chemical groups on the second article to obtain covalent bonds and form a final article.

[0023] International Publication No. 2019 / 185302 discloses a primer formulation for melamine in which it has been observed that a complex formed between a secondary amine and a carbon-carbon double bond can be initiated by chemical radiation. The present invention is useful for coatings when a sufficient amount of chemical radiation can penetrate the liquid layer and generate a sufficient amount of covalent bonds between the substrate and the coating.

[0024] It is desirable to be able to provide coatings for substrates other than those containing secondary amines. Regarding thermosetting substrates containing secondary amines, the elastic modulus is high; for example, melamine-formaldehyde has an elastic modulus exceeding approximately 7 GPa. On the other hand, the added layer described in International Publication No. 2019 / 185302 has a considerably lower elastic modulus, and it is desirable to provide substrates and related coating technologies with a lower difference in elastic modulus between the substrate and the coated layer.

[0025] In the case of primers according to prior art, curing must be adjusted so that a sufficient number of reactive groups remain when the primer is applied. It is desirable to provide a method that is less sensitive to curing conditions, and in particular less sensitive to excessive curing.

[0026] The problem with the conventional technology is that certain impurities in the substrate, or intentionally added compounds such as antioxidants, can act as inhibitors, resulting in the inability or at least interference of the reaction with conventional photoinitiators for film formation.

[0027] Another problem in the prior art is to provide a primer that can harden to a dry state, i.e., touch-dry, in order to facilitate handling before the subsequent coating is applied and cured. [Overview of the Initiative]

[0028] The object of the present invention is to eliminate at least some of the drawbacks of the prior art and to provide an improved coating and / or primer.

[0029] In the first embodiment, a method for coating a substrate is provided, and this method is a) To provide a substrate comprising at least one chemical group selected from the group consisting of aromatic rings, sulfur, and peroxides, wherein at least a portion of the at least one chemical group is on the surface of the substrate. b) At least a portion of the substrate surface, i) A compound comprising at least one carbon-carbon double bond, which may also contain a chemical group capable of abstracting hydrogen, ii) A mixture comprising a first monomer M1 and a second monomer M2, wherein the monomers can undergo a polymerization reaction to form a copolymer covalently bonded to a substrate, and at least one of the ratios r1 and r2 is less than 0.45, and k 11 and k 22 One of them is at least 10 times larger than the other, provided that r1=r2=0, k 11 and k22 Except when the conditions regarding it are not applicable, r1 = k 11 / k 12 and r2 = k 22 / k 21 and wherein k 11 is the growth rate constant of the growth reaction added to the copolymer chain ~M1 growing the monomer M1 * and wherein k 12 is the growth rate constant of the growth reaction added to the copolymer chain ~M1 growing the monomer M2 * and wherein k 21 is the growth rate constant of the growth reaction added to the copolymer chain ~M2 growing the monomer M1 * and wherein k 22 is the growth rate constant of the growth reaction added to the copolymer chain ~M2 growing the monomer M2, contacting one of the mixture * and c) Initiating the reaction using actinic rays to form a covalent bond by reaction of the at least one chemical group on the surface of the substrate with i) a compound or ii) monomers M1 and M2, and as a result, i) a polymer or ii) a copolymer covalently bonded to the substrate surface is formed d) Applying at least one of a coating and a sheet to the surface of the substrate e) Curing at least one coating including the continuous steps of

[0030] In a second aspect, a substrate coated according to the above method is provided

[0031] The present invention is very suitable for applications where improved adhesion to various substrates is desired

[0032] Furthermore, especially when a top coating is added to the coating, the resulting surface has high hardness and improved scratch resistance. For example, when a thermoplastic sheet or film is added, the wear resistance is improved

[0033] The elastic modulus of the substrate according to the present invention matches the elastic modulus of the coated layer more favorably than that of the prior art. For example, the substrate according to the present invention, which includes PP or PET, has an elastic modulus of less than 3 GPa, which matches the elastic modulus of the added layer containing acrylate more favorably. Therefore, by using the present invention, it is possible to avoid weakened layers with significantly different elastic moduli.

[0034] Furthermore, it has the advantage of allowing the primer to harden to a non-sticky or non-wetting state after the topcoat or subsequent coating has been applied and cured.

[0035] The method according to the present invention is less sensitive to curing conditions, and in particular less sensitive to very high doses of chemical radiation. The reaction method according to the present invention stops the reaction after step c) with the initial composition, and any remaining excess groups do not react in any way to over-curing within reasonable boundaries, ensuring a sufficient amount of remaining reactive groups for reaction with the second layer in subsequent steps.

[0036] This method is suitable for chemical wire curing under inert conditions, such as a nitrogen atmosphere. Because this method does not involve oxygen inhibition, it is less susceptible to over-curing of the top surface than current primer formulations.

[0037] The method according to the present invention has low susceptibility to aging due to the low homopolymerization rate and glassy state of the excess reactive groups after curing, which hinders diffusion and therefore further reduces homopolymerization. Furthermore, although this may overlap with other descriptions, various aspects of the present invention are shown below. However, the present invention is not limited to the following. [1] A method for coating a substrate, a) To provide a substrate comprising at least one chemical group selected from the group consisting of aromatic rings, sulfur, and peroxides, wherein at least a portion of the at least one chemical group is located on the surface of the substrate. b) At least a portion of the surface of the substrate, i) A compound comprising at least one carbon-carbon double bond, which may also contain a chemical group capable of abstracting hydrogen, ii) The first monomer M 1 and the second monomer M 2 A mixture comprising the monomers, wherein the monomers undergo a polymerization reaction to form a copolymer covalently bonded to the substrate, and the ratio r 1 and r 2 At least one of them is less than 0.45, k 11 and k 22 One of them is at least 10 times larger than the other, provided that r 1 =r 2 If = 0, k 11 and k 22 Except in cases where the above conditions relating to r do not apply, 1 =k 11 / k 12 and r 2 =k 22 / k 21 And, In the formula, k 11 is monomer M 1 Growing copolymer chain ~M 1 * This is the growth rate constant of the growth reaction applied, In the formula, k 12 is monomer M 2 Growing copolymer chain ~M 1 * This is the growth rate constant of the growth reaction applied, In the formula, k 21 is monomer M 1 Growing copolymer chain ~M 2 * This is the growth rate constant of the growth reaction applied, In the formula, k 22 is monomer M 2 Growing copolymer chain ~M 2 * The growth rate constant of the growth reaction added is the contact between one of the mixtures, First monomer M 1 and the second monomer M 2 However, the following options are available: i)M 1 It is acrylic, M 2 It is a male art, ii) M 1 It is acrylic, M 2 It is vinyl ether, iii) M 1 It is methacrylate, M 2 It is vinyl ether, iv)M 1 It is acrylic, M 2 It is an allyl ether, v)M 1 It is methacrylate, M 2 It is a male art, vi)M 1 It is methacrylate, M 2 It is maleimide, vii)M 1 It is acrylic, M 2 It is maleimide, viii)M 1 It is vinyl ether, M 2 It is a male art, ix)M 1 It is styrene, and M 2 It is a Maleart. It is one of them, c) Initiate the reaction using a chemical beam, and the at least one chemical group on the surface of the substrate and i) the compound or ii) the monomer M 1 and M 2 Through a reaction with the above, a covalent bond is formed, and as a result, i) a polymer or ii) a copolymer is formed covalently bonded to the surface of the substrate. f) Applying at least one of a coating and a sheet to the surface of the substrate, g) curing at least one of the coatings, A method comprising a series of steps. [2] The method according to [1], further comprising the step of removing, after step c), at least a portion of the i) compound or ii) the mixture that has not reacted to form a covalent bond. [3] The method according to [1] or [2], wherein the substrate comprises at least one selected from the group consisting of polyolefins, polymers containing aromatic groups, polymers containing ether groups, and polymers containing sulfur. [4] The method according to any one of [1] to [3], wherein the substrate comprises at least one selected from the group consisting of polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polymethyl methacrylate (PMMA), poly-p-phenylene oxide (PPO), acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), polystyrene (PS), polyether ether ketone (PEEK), and polycarbonate (PC). [5] The method according to any one of [1] to [4], wherein the surface is treated with at least one selected from the group consisting of corona treatment, plasma treatment and flame treatment prior to step b). [6] The method according to any one of [1] to [5], wherein the compound contains an electron-withdrawing group adjacent to at least one carbon-carbon double bond. [7] The method according to any one of [1] to [6], wherein electron-withdrawing groups are present on both sides of the at least one carbon-carbon double bond in the compound. [8] i) the compound or ii) the mixture is dissolved in at least one solvent before contact with the substrate surface, according to any one of [1] to [7]. [9] i) The compound or ii) The mixture is not dissolved or diluted in a solvent before contact with the substrate surface, according to any one of [1] to [8].

[10] The method according to any one of [1] to [9], wherein the substrate surface further comes into contact with at least one compound containing at least one thiol group in step b).

[11] The method according to

[10] , wherein the ratio (r) of the number of thiol groups to the number of carbon-carbon double bonds in step b) satisfies 0.05 ≤ r ≤ 20.

[12] The method according to

[10] , wherein the ratio (r) of the number of thiol groups to the number of carbon-carbon double bonds in step b) satisfies 0.2 ≤ r ≤ 5.

[13] The method according to

[10] , wherein the ratio (r) of the number of thiol groups to the number of carbon-carbon double bonds in step b) satisfies one of 0.3 ≤ r ≤ 0.9 and 1.1 ≤ r ≤ 3.

[14] The method according to any one of [1] to

[13] , wherein in step b), a Norrish type II photoinitiator is brought into contact with the surface of the substrate.

[15] The method according to any one of [1] to

[14] , wherein the contact in step b) is performed by coating layers having a thickness at intervals of 0.2 μm to 20 μm.

[16] The method according to any one of [1] to

[15] , wherein i) the compound or ii) the mixture to be applied in step b) is provided in an acidic mixture.

[17] The method according to any one of [1] to

[16] , wherein all the ingredients added in step b) are provided in a single formulation.

[18] The method according to

[17] , wherein the formulation is acidic and comprises a Norrish type II photoinitiator in addition to the compound.

[19] The method according to

[17] , wherein the thickness of the coating layer containing the compound or ii) the mixture and the absorbance of the coating layer at the wavelength of the chemical line are adapted so that the reaction still starts in step c).

[20] The method described in any of [1] to

[19] , wherein the irradiation is performed by UV radiation.

[21] The method according to any one of [1] to

[20] , wherein the surface in step b) comes into contact with the compound in a certain pattern.

[22] The method according to any one of [1] to

[20] , wherein the irradiation is performed in a pattern.

[23] The method according to any one of [1] to

[22] , wherein the compound is in contact with at least a portion of the surface of the substrate by inkjet in step b).

[24] The method according to any one of [1] to

[23] , wherein at least step c) is performed in an inert atmosphere. [Modes for carrying out the invention]

[0038] Before the present invention is disclosed and described in detail, it should be understood that the present invention is not limited to the specific compounds, compositions, methods, substrates, and materials disclosed herein, and that such compounds, compositions, methods, substrates, and materials may vary to some extent. It should also be understood that the scope of the present invention is limited only by the appended claims and their equivalents, and that the terms used herein are used solely for the purpose of describing specific embodiments and are not intended to limit them.

[0039] As used herein and in the appended claims, the singular forms "a," "an," and "the" refer to multiple subjects unless the context clearly indicates otherwise.

[0040] Unless otherwise defined, any terms and scientific terms used herein are intended to have meanings that are generally understood by those skilled in the art to which the present invention pertains.

[0041] As used herein, (meth)acrylate is a general term encompassing both acrylate and methacrylate.

[0042] As used herein, a photoreactive group means a chemical group that is essentially chemically inert under the conditions in question and becomes reactive when exposed to a chemical ray. Typically, but not always, the chemical ray is ultraviolet light.

[0043] As used herein, hydrogen abstraction is the removal of a hydrogen atom from a molecule. Therefore, a chemical group capable of abstracting hydrogen is a chemical group capable of removing a hydrogen atom.

[0044] All percentages and ratios throughout the specification and claims are calculated by weight unless otherwise indicated. For example, ratio r is calculated based on the number of chemical groups, not by weight.

[0045] In the first embodiment, a method for coating a substrate is provided, and this method is a) To provide a substrate comprising at least one chemical group selected from the group consisting of aromatic rings, sulfur, and peroxides, wherein at least a portion of the at least one chemical group is on the surface of the substrate. b) At least a portion of the substrate surface, i) A compound comprising at least one carbon-carbon double bond, which may also contain a chemical group capable of abstracting hydrogen, ii) A mixture comprising a first monomer M1 and a second monomer M2, wherein the monomers can undergo a polymerization reaction to form a copolymer covalently bonded to a substrate, and at least one of the ratios r1 and r2 is less than 0.45, and k 11 and k 22One of them is at least 10 times larger than the other, provided that r1=r2=0, k 11 and k 22 Except for the fact that the conditions regarding r1=k do not apply, 11 / k 12 and r²=k 22 / k 21 And, In the formula, k 11 This is the monomer M1 growing copolymer chain ~M1 * This is the growth rate constant of the growth reaction applied, In the formula, k 12 This involves growing monomer M2 into copolymer chain ~M1 * This is the growth rate constant of the growth reaction applied, In the formula, k 21 This involves growing monomer M1 into copolymer chain ~M2 * This is the growth rate constant of the growth reaction applied, In the formula, k 22 This is the monomer M2 growing copolymer chain ~M2 * The growth rate constant of the growth reaction added is the contact between one of the mixtures, c) The reaction is initiated using a chemical beam to form a covalent bond between at least one chemical group on the surface of the substrate and i) the compound or ii) monomers M1 and M2, resulting in the formation of i) a polymer or ii) copolymer covalently bonded to the surface of the substrate. d) Applying at least one of a coating and / or a sheet to the surface of the substrate, e) Curing at least one coating This includes a series of steps.

[0046] We consider two different monomers M1 and M2. A copolymer chain ~M1 is formed by attaching monomers M1 and M2 to one end of a polymer chain, respectively. * and ~M2 * Considering its growth, the following reactions occur.

number

[0047] Next, r1 and r2 are given by r1 = k 11 / k 12 and r²=k 22 / k 21 It is defined as follows, where k 11 , k 12 , k 21 , and k 22 is the growth rate constant for the above growth reaction. r1 is ~M1 * Reactivity between M1 and ~M1 * This is interpreted as the reactivity with M2. r2 is ~M2 * Reactivity between ~M2 and M2 * This is interpreted as a reaction with M1. The growing polymer chain is a copolymer having either M1 or M2 at one end. At least a portion of the copolymer is covalently bonded to the substrate surface. In one embodiment, copolymers that are not covalently bonded to the surface are washed away after the reaction. The ratios r, r1, and r2 are different ratios.

[0048] At least one of r1 and r2 is less than 0.45. Either r1 is less than 0.45, or r2 is less than 0.45, or both r1 and r2 are less than 0.45. In one embodiment, at least one of r1 and r2 is less than 0.1. In one embodiment, at least one of r1 and r2 is less than 0.05. In one embodiment, one of r1 and r2 is 0 or close to 0. In one embodiment, both r1 and r2 are 0 or close to 0. This ratio indicates that homopolymerization is suppressed in one of the reactions.

[0049] rate constant k 11 , k 22 Regarding this, one is at least 10 times larger than the other, and 10 × k 11 ≤k 22 or 10 × k 22 ≤k 11Therefore, it is found that in one reaction, the homopolymerization rate is much faster than in the other. The selection of this parameter makes it possible to apply and cure the polymerization of the coating in different steps. After the first curing, reactive groups remain for the second curing reaction. When r1=r2=0, an alternating copolymer without homopolymerization exists, and k 22 and k 11 The conditions regarding r1 do not apply. This also applies when both r1 and r2 are approximately 0, such that r1 ≈ r2 ≈ 0. This condition is met when both r1 and r2 are less than 0.05.

[0050] low k 22 In the case of a mixture where r1 > r2, even if M1 is in excess, M2 will remain as a residual group that reacts later.

[0051] The term monomer should be interpreted as a polymerizable unit, encompassing both monomers and polymerizable oligomers. This allows for reactions with polymerized oligomers.

[0052] In one embodiment, in step b), the substrate surface is brought into contact with a mixture containing a first monomer M1 and a second monomer M2. In one embodiment, the first monomer M1 and the second monomer M2 are selected from the following options. i) Acrylate and mareal, ii) Acrylate and vinyl ether, iii) Methacrylate and vinyl ether, iv) Acrylates and allyl ethers, v) Methacrylate and maleate, vi) Methacrylate and maleimide, vii) Acrylate and maleimide viii) vinyl ether and maleate, and ix) Styrene and Maleate It is one of them.

[0053] The first monomer M1 and the second monomer M2 are selected from one of options i) to ix). Options i) to ix) each contain two different groups, and the first and second monomers are selected so that there is one of each. In one embodiment, the first monomer M1 and the second monomer M2 are acrylate and maleate. In one embodiment, the first monomer M1 and the second monomer M2 are acrylate and vinyl ether. In one embodiment, the first monomer M1 and the second monomer M2 are methacrylate and vinyl ether. In one embodiment, the first monomer M1 and the second monomer M2 are acrylate and allyl ether. In one embodiment, the first monomer M1 and the second monomer M2 are methacrylate and maleate. In one embodiment, the first monomer M1 and the second monomer M2 are methacrylate and maleimide. In one embodiment, the first monomer M1 and the second monomer M2 are acrylate and maleimide. In one embodiment, the first monomer M1 and the second monomer M2 are vinyl ether and maleate. In another embodiment, the first monomer M1 and the second monomer M2 are styrene and maleate. Therefore, the first monomer M1 and the second monomer M2 can be the selected pair described above.

[0054] The above monomer pair satisfies the requirement regarding the ability to undergo polymerization reactions and form a copolymer covalently bonded to the substrate. The above monomer pair also satisfies the requirement that at least one of the ratios r1 and r2 is less than 0.45, and further k 11 and k 22 The requirement that one of them is at least 10 times larger than the other is satisfied. Therefore, the above list of monomer pairs can substitute for the above general requirement for monomers.

[0055] This method includes step d) applying at least one of a coating and / or a sheet to the substrate surface. A liquid coating can be applied and then preferably cured, or a sheet or film can be applied. Therefore, a selection from liquid coatings, sheets, and films is applied in step d).

[0056] This method includes a subsequent step e) for curing at least one coating or sheet applied in step d). Such step e) is performed after step d). When the coating is the final coating, it is sometimes called a topcoat. Adding a topcoat to a coating, in particular, results in a surface with high hardness and improved scratch resistance. If the outermost layer is a coating film, abrasion resistance can be improved. In one embodiment, a second coating is applied after step c). This second coating can be called a topcoat if no further coatings are applied. The properties of the resulting finished coated substrate, including the topcoat, are dramatically improved when using this method. In one embodiment, at least one further coating is applied after step c). Thus, in one embodiment, the coating is used as a primer. The coating can also be used as a single coating or as a topcoat on another coating.

[0057] In one embodiment, the second layer applied in step d) is an article such as a thermoplastic sheet. When added, design elements such as an embossed structure become possible. When added, abrasion resistance is greatly improved.

[0058] In one embodiment, the sheet comprises polypropylene and / or polyethylene or other polymer material, which has the advantage of being transparent to chemical rays that can come into contact with a liquid containing carbon-carbon double bonds to initiate a surface reaction of photoactive groups located on the surface away from light. Thus, the applied sheet is fixed to the surface by curing with a chemical ray, the chemical ray is applied through the applied sheet and reaches the interface between the applied sheet and the substrate surface.

[0059] In another embodiment, a thermoplastic sheet containing PET is activated by irradiation on at least one surface of the sheet, and after the sheet, in step d), it comes into contact with a treated substrate, with the irradiated surface of the sheet facing downward relative to the substrate. This step is necessary because PET is typically not transparent to the relevant wavelengths.

[0060] In one embodiment, the acrylic coating is applied as at least one further coating, i.e., a second coating.

[0061] In one embodiment, the method further includes, after step c), a step of removing at least a portion of the i) compound or ii) mixture that has not reacted to form a covalent bond. Excess molecules and any other optional additives can be removed by washing or other suitable means.

[0062] For example, corona, plasma, or flame surface-activated polyolefins, polymers containing aromatic groups, polymers containing ethers, and polymers containing sulfur can be successfully coated. The adhesion of the subsequent topcoat is greatly improved. In one embodiment, the substrate comprises at least one selected from the group consisting of polyolefins, polymers containing aromatic groups, polymers containing ether groups, and polymers containing sulfur. In one embodiment, the surface is treated with at least one selected from the group consisting of corona treatment, plasma treatment, and flame treatment prior to step b).

[0063] There are several different substrates that can be used in the present invention. In one embodiment, the substrate includes at least one selected from the group consisting of polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polymethyl methacrylate (PMMA), poly-p-phenylene oxide (PPO), acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), polystyrene (PS), polyether ether ketone (PEEK), and polycarbonate (PC).

[0064] In one embodiment, an electron-withdrawing group is present adjacent to at least one carbon-carbon double bond in the compound. In another embodiment, electron-withdrawing groups are present on both sides of at least one carbon-carbon double bond in the compound. When a compound containing at least one thiol group is present, the electron-withdrawing group has the advantage of giving a faster reaction.

[0065] In one embodiment, i) the compound or ii) the first monomer M1 and the second monomer M2 are dissolved in at least one solvent before contact with the substrate surface. In an alternative embodiment, i) the compound or ii) the first monomer M1 and the second monomer M2 are not dissolved or diluted in a solvent before contact with the substrate surface. In the latter embodiment, i) the compound or ii) the first monomer M1 and the second monomer M2 are used alone. In the latter embodiment, additional additives may be added to i) the compound or ii) the first monomer M1 and the second monomer M2. In one embodiment, if i) the compound or ii) the first monomer M1 and the second monomer M2 are not dissolved or diluted in a solvent, it may be possible to select a low viscosity i) the compound or ii) the first monomer M1 and the second monomer M2, and as a result, roller coating can be performed efficiently with the appropriate thickness.

[0066] In one embodiment, the substrate surface is further contacted with at least one compound containing at least one thiol group in step b). In one embodiment, the ratio (r) of the number of thiol groups to the number of carbon-carbon double bonds in step b) satisfies 0.05 ≤ r ≤ 20. In another embodiment, the ratio r satisfies 0.2 ≤ r ≤ 5. In yet another embodiment, the ratio r satisfies one of 0.3 ≤ r ≤ 0.9 and 1.1 ≤ r ≤ 3, and therefore the latter embodiment requires a non-stoichiometric ratio between thiol groups and carbon-carbon bonds. The addition of thiols has the advantage that the surface can be dried so that the surface of the substrate is dry after step c). The substrate is then easier to handle and can be subsequently coated with a further coating in step d). (The ratio r is different from ratios r1 and r2).

[0067] In one embodiment, the i) compound or ii) the first monomer M1 and the second monomer M2 that are brought into contact with the substrate surface in step b) are pure substances, and in an alternative embodiment of step b), the substrate surface is brought into contact with a formulation containing the i) compound or ii) the first monomer M1 and the second monomer M2. Such a formulation may also contain additional compounds, additives, and solvents.

[0068] In one embodiment, i) the compound or ii) the first monomer M1 and the second monomer M2 are inkjet-printed onto the surface in step b). In one embodiment, i) the compound or ii) the first monomer M1 and the second monomer M2 are brought into contact with at least a portion of the substrate surface by inkjet printing in step b). In addition to or instead of the above, other known coating methods such as roller coating, anilox roll coating, spraying, and dipping can be used.

[0069] In one embodiment, the first monomer M1 is acrylate, and r1 is less than 10. This embodiment is also applied when the second monomer M2 is acrylate instead. This improves the bonding with acrylate.

[0070] In one embodiment, one of r1 and r2 is greater than 0.1. This promotes film formation.

[0071] In one embodiment, k 11 and k 22 One of the values ​​is less than 3000 l / (mol s). This reduces the tendency for over-hardening. Over-hardening such a mixture is extremely difficult. The growth constant is measured by the rotational sector method.

[0072] In one embodiment, in step b), the Norrish type II photoinitiator is brought into contact with the substrate surface. In one embodiment, any additional substances brought into contact with the substrate surface in step b), such as the Norrish type II photoinitiator, are added together with i) the compound or ii) the first monomer M1 and the second monomer M2. In another embodiment, they are added separately before and / or after contacting i) the compound or ii) the mixture with the substrate surface. In one embodiment, the photoinitiator is present in the mixture in step b). In one embodiment, the Norrish type II photoinitiator is present in the mixture in step b).

[0073] Photoinitiators based on hydrogen abstraction can also be called Norrish type II photoinitiators. Electrically excited carbonyl compounds are hydrogen abstractors that can be considered Norrish type II photoinitiators. Suitable carbonyl compounds for Norrish type II photoinitiators include aromatic ketones and quinones, such as benzophenone, ketosulfone, thioxanthene, 1,2-diketone, anthraquinone, fluorenone, xanthone, acetophenone derivatives, benzoin ether, benzyl ketal, phenylglyoxylate, mono- and bis-acylphosphine. In one embodiment, the Norrish type II initiator is an initiator selected from the group consisting of benzophenone, thioxanthone, 1,2-diketone, and anthraquinone. Suitable Norrish type II initiators are disclosed by CRIVELLO JV et al. in "Volume III: Photoinitiators for Free Radical Cationic & Anionic Photopolymerization," 2nd edition, edited by BRADLEY G., John Wiley & Sons Ltd, London, UK, 1998, pp. 287-294, which are incorporated herein by reference in their entirety.

[0074] In one embodiment, the Norrish type II photoinitiator is present in the formulation added in step b) in an amount of 0.1 to 15% by weight, based on the weight of the photosensitive composition that comes into contact with the substrate surface.

[0075] In one embodiment, the contact in step b) is performed by coating layers having a thickness of 0.2 to 20 μm. In step b), coating techniques known to those skilled in the art can be used to coat i) the compound or ii) the first monomer M1 and the second monomer M2 and other components.

[0076] In one embodiment, all components added in step b) are provided in a single formulation. This simplifies the addition process. Then, all the compounds and additional substances are coated into a single mixture.

[0077] In one embodiment, the i) compound or ii) the first monomer M1 and the second monomer M2 to be applied in step b) are provided in an acidic mixture. For certain applications, acidity improves shelf life. In one embodiment, the formulation is acidic and contains a Norrish type II photoinitiator in addition to the i) compound or ii) the first monomer M1 and the second monomer M2. A low pH in the acidic formulation improves the shelf life of the Norrish type II photoinitiator. The combination of a Norrish type II photoinitiator and an acidic pH is particularly suitable for improving the shelf life of the formulation added in step b).

[0078] In one embodiment, irradiation is performed by UV radiation. Many photoreactive groups become reactive upon UV irradiation at an appropriate energy.

[0079] In one embodiment, in step b), the surface is brought into contact with i) the compound or ii) the first monomer M1 and the second monomer M2 in a pattern. This allows for partial treatment of the substrate surface to form a desired pattern. Therefore, it is possible to form a pattern by applying i) the compound or ii) the first monomer M1 and the second monomer M2 in a desired pattern.

[0080] In one embodiment, irradiation is performed in a pattern. This provides an additional possibility for surface modification of the substrate surface in a desired pattern. Pattern irradiation is performed by known methods, such as applying a mask or irradiating with a laser. Thus, it is possible to form a pattern on the substrate by irradiating only a portion of the surface where photosensitive groups are present.

[0081] In one embodiment, the thickness of the coating layer containing i) the compound or ii) the first monomer M1 and the second monomer M2, and the absorbance of the coating layer at the wavelength of the chemical rays, are adapted so that the reaction still begins in step c). After considering the description, those skilled in the art can adjust the thickness of the coating layer and the absorbance of the coated formulation so that sufficient irradiation reaches the substrate surface when the layer is coated. The absorbance is adjusted by adjusting the concentration of the components in the formulation that absorb the chemical rays at the relevant wavelengths. The Lambert-Beer law can assist those skilled in the art in this regard.

[0082] In one embodiment, at least step c) is carried out in an inert atmosphere. In another embodiment, steps b) and c) are carried out in an inert atmosphere. In another embodiment, steps b), c) and d) are carried out in an inert atmosphere. In another embodiment, steps b), c), d) and e) are carried out in an inert atmosphere. In another embodiment, steps a), b), c), d) and e) are carried out in an inert atmosphere. In one embodiment, the inert atmosphere contains 98% by weight or more of an inert gas, preferably 99% by weight or more of an inert gas, more preferably 99.5% by weight or more of an inert gas. Alternatively, the inert atmosphere contains 95% by weight or more of an inert gas. In one embodiment, the inert atmosphere contains 2% by weight or less of oxygen, preferably 1% by weight or less of oxygen, more preferably 0.5% by weight or less of oxygen. In one embodiment, the inert gas contains nitrogen. When an inert atmosphere is used, the method is less susceptible to overhardening of the top surface because there is no oxygen inhibition.

[0083] In a second embodiment, a substrate coated according to the method described above is provided.

[0084] The substrate contains molecules that are surface-accessible peroxides and / or sulfur and / or aromatic groups. A compound containing at least one C=C double bond is added to the substrate. Alternatively, a first monomer M1 and a second monomer M2 are added to the substrate.

[0085] A crucial characteristic is that the reaction is initiated by direct irradiation of chemical groups on the substrate surface. These chemical groups directly absorb energy from the chemical rays. Such chemical groups can also be called photoreactive groups. In the case of peroxides, the peroxide cleaves into alkoxy radicals and free hydroxyl radicals or alkoxy radicals bound to the surface, depending on the molecular structure of the peroxide bonded to the surface.

[0086] Substitutive phenyl groups are excited by UV light, forming triplet or singlet states. These excited states can react with carbon-carbon double bonds in many ways. a) In the presence of a hydrogen donor, a triplet state of a substituted phenyl ring (terephthalate in the case of PET) formed by UV radiation of a specific minimum energy forms a biradical structure on the phenyl ring. These radicals can form covalent bonds with the carbon-carbon double bond, or form peroxy radicals in the presence of atmospheric oxygen, which form peroxides upon hydrogen abstraction, and which can form alkoxy radicals that react with the carbon-carbon double bond to form a covalent bond when cleaved by UV light. b) In some cases, a radical anion is formed, which can react with an electron-deficient carbon-carbon double bond via an anionic addition reaction.

[0087] Photoinitiators are not required, but are added in some embodiments. In practice, the addition of photoinitiators is generally not advisable because they may absorb chemical rays and therefore cannot be used to initiate the reaction. UV-absorbing compounds such as photoinitiators should generally only be tolerated in trace amounts. The amount of photoinitiators typically used to initiate various reactions is generally too much. In one embodiment, no photoinitiator is added. In one embodiment, there is no photoinitiator, or any other compound that absorbs chemical rays, at all. Under some conditions, a certain amount of a specific photoinitiator may be tolerated and used. Such conditions include: a) The wavelengths at which the chemical groups on the surface of the substrate absorb energy are sufficiently different from the wavelengths at which the photoinitiator absorbs light. b) The coating layer containing the photoinitiator is very thin so that a sufficient amount of radiation reaches the chemical groups on the surface of the substrate anyway, and / or the coating layer containing the photoinitiator is diluted so that a sufficient amount of radiation reaches the chemical groups on the surface of the substrate anyway.

[0088] The above conditions can also be combined with an increase in the intensity and / or dose of the chemical beam.

[0089] Conventional primer coatings are typically applied in layers ranging from 10 to 30 microns and are designed to form a film with minimal UV radiation. UV radiation below 370 nm reaching the bottom of the layer is always very low. Adhesion of such films by prior art is either due to surface energy matching or to a secondary spontaneous reaction between hydroxyl groups present after corona treatment and isocyanate groups in the primer.

[0090] Since the chemical groups are present on the substrate surface, the chemical rays must pass through the coated solution layer to reach the substrate surface. In comparable prior art, photoinitiators or other UV-blocking compounds are used in similar systems, which either prevent the chemical rays from reaching the surface or prevent them from reaching it at all, making this method impossible to use or impossible to observe in most systems. The inventors believe this is why this effect has not been observed previously.

[0091] As a result of the reaction, covalent bonds are formed. The presence of covalent bonds can be confirmed, for example, by the inability to remove the film by boiling the substrate and film in water for two hours. A removed film indicates the absence of covalent bonds. A film that still adheres after boiling in water for several hours (two hours) may indicate the presence of covalent bonds and / or molecular entanglement, i.e., an IPN (interpenetrating network)-like structure. Therefore, a removed film ensures the absence of covalent bonds. However, a film that still adheres after boiling in water for several hours may indicate covalent bonds or alternative entanglement of polymer chains. Therefore, to ensure the presence of covalent bonds when the film remains adhered, it is necessary to rule out polymer chain entanglement, i.e., an IPN-like structure.

[0092] Covalent bonding can be distinguished from adhesion originating from IPN-like morphology by taking a cross-cut of the coated substrate and examining the interface between the substrate and the coating. In the case of primarily covalent bonding, the surface structure of the substrate remains essentially intact, whereas in the case of primarily IPN-like morphology, there is a transition region between the coating and the substrate that differs from the original substrate surface structure, which can be detected by spectroscopic measurements (e.g., IR or Raman microscopy), SEM, optical microscopy, or similar methods. If adhesion from IPN-like morphology is ruled out, it can be concluded that covalent bonding must be present.

[0093] In general, the level of the photoinitiator or other absorbing compound should not be so high that it prevents the reaction of chemical groups on the surface of the substrate from starting. Therefore, in one embodiment, the photoinitiator is present in an amount that does not hinder the initiation of the reaction in which cleaved chemical groups on the surface of the substrate react with carbon-carbon double bonds to form covalent bonds.

[0094] In general, film formation by double bond consumption should not be too rapid, so that an insufficient amount of chemical radiation can form covalent bonds between the carbon-carbon double bonds and the photoreactive groups before the carbon-carbon double bonds are consumed or diffusion to the surface is hindered by the high viscosity of the evolving network.

[0095] Because the diffusion of carbon-carbon double bonds is rapid until late in film formation, delayed gelation in thiol-enes, where the viscosity does not change essentially before the gelation point, is suitable to counteract this effect if necessary. Furthermore, the initiator-free initiation ability of thiol-enes is advantageous because chemical rays at the effective wavelength are hardly absorbed, and most of the chemical rays reach the photoreactive groups on the surface. These are therefore further advantages of adding compounds containing at least one thiol group.

[0096] Chemical rays (typically UV rays) should reach the surface of the substrate where the photosensitive groups are located. This can be achieved by irradiation of the surface. In one embodiment, this can be achieved by irradiation passing through the substrate, provided that it is transparent and / or very thin at the relevant wavelengths. Solutions containing compounds with at least one C=C double bond should not excessively absorb chemical rays. The product of the thickness of such a coated solution and its absorption at the relevant wavelengths should not be too high so that sufficient chemical rays can reach the surface of the substrate where the photosensitive groups are present. Higher absorption of radiation in such solutions can be compensated to some extent by thinner coated solutions.

[0097] A similar principle applies to the coating solution and / or sheet applied in step d), that at least an effective amount of chemical radiation should reach the surface groups. In such embodiments, the optical path passes through the coating solution or sheet before reaching the opposite side of the thermoplastic sheet. In the case of thermoplastic sheets according to the prior art, the UV-activated adhesive is designed to react very rapidly to form a solid polymer, and essentially all carbon-carbon double bonds are consumed within a timeframe too short to observe covalent bonding by chemical radiation activation of photoreactive groups on the thermoplastic sheet surface facing the applied primer. This explains why the effect had not been noticed previously.

[0098] The following table shows examples of suitable pairs of monomers M1 and M2 that are suitable for use together in the present invention. [Table 1]

[0099] The values ​​of r1 and r2 are calculated using the Alfrey Price Qe formula, where r1 = (Q1 / Q2)exp[-e1(e1-e2)] and r2 = (Q2 / Q1)exp[-e2(e2-e1)]. Published Q and e values ​​for monomer pairs can be used to estimate r1 and r2 when the actual copolymerization has not been studied in detail. 11 and k 22 This information is obtained from literature.

[0100] k 22 Regarding the term "low" in the table, 11 This indicates a value much lower than the given value, i.e., more than 10 times lower. This is not true if both r1 and r2 are very close to 0. Very close to 0 is interpreted as less than 0.05. [Table 2]

[0101] Both maleate and fumarate exist in unsaturated polyesters and are therefore included in the present invention, although their rate constants differ slightly from each other.

[0102] As explained in more detail above, K 11 k is the growth rate constant for M1 homopolymerization, and 22 This is the growth rate constant for M2 homopolymerization.

[0103] It should be understood that the present invention is not limited to the specific embodiments shown herein. The scope of the present invention is limited only by the appended claims and equivalents, and the embodiments are provided for illustrative purposes only and are not intended to limit the scope of the invention. [Examples]

[0104] Example 1 (Bo-PET) Thin films of Bo-PET (biaxially oriented polyethylene terephthalate) were cut to serve as substrates. The pieces were wiped with IPA (isopropyl alcohol). A thin layer of either pure hexanediol diacrylate (HDDA) or a commercially available UV-curing acrylate topcoat (UE1664) from Bona AB containing a photoinitiator was applied to the PET film as a primer at a thickness of approximately 1 μm (1 g / sqm). The PET film with the primer layer was placed in a curing apparatus including a conveyor belt and a fixed medium-pressure mercury lamp that irradiates with UVA, UVB, UVC, and UVV. Different UV doses were tested.

[0105] The surface properties of the primer layer immediately after UV exposure were tested using a gloved finger and a spatula to determine whether the primer layer had hardened. If a gloved finger or spatula left a mark on the primer layer, the surface was determined to be "wet." If a gloved finger or spatula left no mark on the primer layer, the surface was determined to be "dry." If part of the surface was dry and other parts were wet, or if very faint marks were observed, the surface was determined to be "almost dry." If the surface was sticky to the touch of a gloved finger, the surface was determined to be "sticky." These results are shown under "Surface Properties" in the table below.

[0106] Next, a thicker layer of Bona AB's UV-curing acrylate topcoat (UE1664) was applied over the primer layer using a 22 μm rod applicator, and cured in the same apparatus at 1.4 J / cm². 2 The layer was completely cured and dried by applying a UV dose of (UVA).

[0107] The adhesion of the coating layer to the substrate was tested using a standard tape test ("cross-hatch test") according to the cross-cut test described in ISO 2409. In short, each was approximately 1 mm 2 In a square pattern of 25 areas, cuts were made through the coating to the substrate. The tape was pressed onto the coating and quickly pulled off. The resulting damage was evaluated by assessing the amount of coating removed by the tape, with CH=0 representing the best adhesion (no removal of coating) and CH=5 representing the worst adhesion (all or almost all of the coating removed).

[0108] For reference, a 22 μm thick UV-curable acrylate-based topcoat was applied and cured, and no primer layer was applied to the PET film before testing in the same manner as above.

[0109] The results are shown in the table below. [Table 3]

[0110] The results in the table above show that adhesion is significantly improved compared to the reference example (#5) by using a thin primer layer of either pure HDDA or UV-curing acrylate topcoat UE1664, which activates the substrate surface when exposed to UV light. However, once the thin UE1664 is cured to dry, the interlayer adhesion between the primer layer and the thick topcoat is compromised, resulting in a failure of the cross-hatch test. This demonstrates the difficulty of obtaining the dry primer layer required in some applications while still maintaining interlayer adhesion with the subsequently applied coating layer.

[0111] Example 2 (PET) Another example follows the exact same procedure as above, but uses a 2mm thick PET sheet (polyethylene terephthalate) purchased from Nordbergs Tekniska AB as the base material. [Table 4]

[0112] In a thin undercoat layer of HDDA before the topcoat, excellent results were obtained on the PET sheet using cross-hatching. No surface was used.

[0113] Example 3 (BoPET, thicker HDDA) Another experiment was conducted using the same method and substrate as in Example 1, but instead of applying a 1 μm undercoat layer, a layer of HDDA approximately 14 μm thick was applied. In this case, the uncured HDDA on the PET substrate was wiped off before applying the topcoat. [Table 5]

[0114] Example 4 (Non-stoichiometric acrylate on boPET) Another experiment using the same method and substrate as in Example 1 was performed using either a formulation of 70 wt% HDDA (1,6-hexanediol diacrylate) and 30 wt% PETMA (pentaerythritol-tetramercaptoacetate) (Formulation "A") or a formulation of 69.75 wt% HDDA, 29.75 wt% PETMA, and 0.5 wt% ITX (Formulation "B"), where ITX is a Norrish type II photoinitiator, as a primer. Both of these formulations have a thiol / acrylate ratio of approximately 0.5, and therefore the nonstoichiometric ratio of acrylate functional groups to thiol functional groups is approximately 100%. The primer layer was applied in a layer of approximately 1 μm thickness (1 g / sqm), as before.

[0115] The adhesion of the coating to the substrate was tested using a cross-hatch test.

[0116] Subsequently, a portion of the sample was immersed in boiling water for two hours, dried, and retested using the cross-hatch test. [Table 6]

[0117] The results above indicate that both formulations A and B pass the cross-hatch test even when dry, meaning that the interlayer adhesion is not compromised. Furthermore, the adhesive properties of the tested samples are not affected even after boiling for two hours.

[0118] Example 5 (PP) Two different types of polypropylene (PP) substrates were used: i) raw PP sheets of different colors ("homogeneous PP") and ii) filled PP films of different colors ("filled PP"), all of which were uncoated.

[0119] Wipe the substrate with IPA, and immediately before applying the primer layer (or topcoat if the reference does not include a primer), apply a 30cm layer. 2Corona treatment was performed using a handheld experimental corona treatment device (Electro-technic products, model BD-20) while moving the electrode over a distance of 5-10 mm for 30 seconds on a large substrate.

[0120] The primer formulations used were both "Formulation A" and "Formulation B" as described in the example above, as well as a formulation (referred to as "Formulation C") consisting of Sartomer monomer SR9020 with 3% ITX and Norrish type II photoinitiator.

[0121] A thin primer layer is applied to a layer approximately 1 μm thick (1 g / m²). 2 The material was then applied to the substrate as described above. Next, the substrate and primer were exposed in the same "Hg" mercury curing apparatus as described in Example 1, but in one example, the primer layer was exposed with a 365nm UV LED exposure apparatus instead (365nm, 3000mJ / cm2, 30mW / cm²). 2 After exposure, the surface properties of the primer were inspected using gloved fingers and a spatula, as described in Example 1. Finally, the same topcoat as in Example 1 was applied with a 22 μm rod applicator and exposed to 1400 mJ / cm². 2 The material was cured using a mercury curing device with UVA radiation doses.

[0122] For reference, as in Example 1, a primer layer was not applied to the corona-treated substrate before applying and curing a 22 μm thick UV-curing acrylate-based topcoat.

[0123] The evaluation was performed using the cross-hatch test described in Example 1.

[0124] Subsequently, a portion of the sample was immersed in boiling water for two hours, dried, and retested using the cross-hatch test. [Table 7]

[0125] Please note that on a dark-colored substrate of filled PP (#26), a 22μm UE1664 topcoat layer will not cure at all.

[0126] Example 6 (PE) In another experiment using the exact same method as in Example 4 (IPA wipe, corona treatment, primer application, UV, topcoat application, and UV), an unprocessed polyethylene (PE) surface of quality "PE1000 natur" purchased from Nordbergs Tekniska AB was used. [Table 8]

[0127] Example 7 (Variation of non-stoichiometry) As mentioned above, filled PP (dark color) was used as the base material.

[0128] As the undercoat layer, a formulation consisting of a variation of formulation A (HDDA and PETMA) was used, and various non-stoichiometric amounts calculated as the ratio of thiol groups to acrylate groups were employed.

[0129] The PP substrate was first wiped with IPA, followed by corona treatment (exactly the same as described in Example 5).

[0130] Next, the primer mixture was immediately applied in a layer approximately 1 μm thick (1 g / sqm) and exposed to a UV mercury lamp at a dose of 2 × 700 mJ / cm2, as measured by UVA (same procedure as in Example 1). Immediately after each 700 mJ / cm2 (UVA) pass, the surface was tested with gloved fingers and a spatula to determine the surface properties, as described in Example 1. Subsequently, a layer of UV acrylate topcoat UE1664 approximately 22 μm thick (22 g / sqm) was applied using a rod applicator and cured by exposure to 1400 mJ / cm2, as measured by UVA.

[0131] Finally, the adhesion of the coating was tested using the cross-hatch test described in Example 1. [Table 9]

[0132] Example 8 (double bond) In this example, the following substrates were used: filled PP (dark color), BoPET, and PE (all as described above).

[0133] Monomer DVE-3 (triethylene glycol divinyl ether) or TAOE (tetra(allyloxy)ethane) was used as the undercoat layer.

[0134] The filled PP (dark color) substrate was corona-treated in exactly the same way as described in Example 5. The BoPET and PE substrates were not corona-treated.

[0135] A primer layer was applied to a thickness of approximately 1 μm (1 g / sqm) and UV-cured using a mercury lamp (measured at 2 × 700 mJ / cm2 using UVA) as before. Subsequently, a layer of UV acrylate UE1664 approximately 22 μm thick was applied and UV-cured (measured at 1400 mJ / cm2 using UVA).

[0136] Finally, the adhesion of the coating was tested using the cross-hatch test described above. [Table 10]

[0137] Example 9 Several different materials were used as substrates. The materials used were: "BoPET film," a thin film of transparent Bo-PET (biaxially oriented polyethylene terephthalate); "PET film," a thin film of transparent PET (polyethylene terephthalate) (0.1 mm thick) purchased from Nordbergs Tekniska AB; "PET 2mm," a 2 mm thick sheet of white PET (polyethylene terephthalate) purchased from Nordbergs Tekniska AB; "Filled PP," an opaque, glossy filled PP sheet purchased from Direktlaminat AB; "PE film," a thin film of polyethylene (PE) (0.25 mm thick) purchased from Nordbergs Tekniska AB; "PE 6mm," a 6 mm thick sheet of unprocessed PE (polyethylene) (quality "PE1000 natur") purchased from Nordbergs Tekniska AB; and "PMMA," a 2 mm thick sheet of transparent PMMA (poly(methyl methacrylate)) purchased from Nordbergs Tekniska AB. The thickness was 2mm, and the surface was hardened acrylic, which was "acrylic".

[0138] The hardened "Acrylate" surface was prepared using a gray melamine board purchased from Direktlaminat AB, coated with a 1μm thick layer of Mercene Labs M1814, and exposed to a medium-pressure mercury lamp at 600mJ / cm². 2 The surface was UV-cured with UVA, and a 12μm layer of Bona AB UV-curing acrylate topcoat (UE1664) was applied. The surface was then treated with a medium-pressure mercury lamp at 1400mJ / cm². 2 It was prepared by UV curing with (UVA) light, completely curing the layer, and then drying it.

[0139] All of the above materials were cut and used as the base material. The pieces were wiped clean with dry tissue paper.

[0140] Two different primer formulations were prepared: "Formulation X" using 49.4 wt% Ebecryl 2221 (a hexa-functional aromatic urethane acrylate oligomer) from Allnex Belgium SA / NV, 49.4 wt% Rapi-Cure DVE-3 (triethylene glycol divinyl ether), and 1.6 wt% Speedcure-2 ITX (a Norrish type II photoinitiator of the thioxanthone family, 2-isopropylthioxanthone) from Lambson Limited; and "Formulation Y" using 48.8 wt% trimethylolpropane diallyl ether 90, 48.8 wt% Ebecryl 2221, and 2.4 wt% Speedcure-2 ITX from Lambson Limited, purchased from Perstorp Specialty Chemicals AB.

[0141] All substrates made from PE or PP (i.e., "filled PP", "PE film", and "PE 6mm") were corona-treated using a handheld laboratory corona treatment device (model BD-20 from Electro-technic products) at a distance of 5 - 10 mm on a large substrate of 30 cm for 30 seconds while moving the electrode immediately before applying the primer layer (top coat in the case of the reference without primer). 2 A thin layer of "Formulation X" or "Formulation Y" was applied as a primer on the substrate as a layer with a thickness of approximately 1 μm (1 g / sqm). The substrate with the primer layer was placed in a curing device containing a conveyor belt and a fixed medium-pressure mercury lamp that irradiates UVA, UVB, UVC, and UVV, and was exposed to a total dose of 600 mJ / cm

[0142] (UVA). 2

[0143] The surface properties of the primer layer immediately after UV exposure were tested using gloved fingers and a spatula to determine whether the primer layer had hardened. If a gloved finger or spatula left a mark on the primer layer, the surface was determined to be "wet." If a gloved finger or spatula left no mark on the primer layer, the surface was determined to be "dry." If part of the surface was dry and other parts were wet, or if very faint marks were observed, the surface was determined to be "almost dry." These results are shown in the "Surface Properties" column of the table below.

[0144] Next, a thicker layer of Bona AB's UV-curing acrylate topcoat (UE1664) was applied over the primer layer using a 22 μm rod applicator, and cured in the same apparatus at 1.4 J / cm². 2 The layer was completely cured and dried by applying a UV dose of (UVA).

[0145] The adhesion of the coating layer to the substrate was tested using a standard tape test ("cross-hatch test") according to the cross-cut test described in ISO 2409. In short, each was approximately 1 mm 2 In a square pattern of 25 areas, cuts were made through the coating to the substrate. The tape was pressed onto the coating and quickly pulled off. The resulting damage was evaluated by assessing the amount of coating removed by the tape, with CH=0 representing the best adhesion (no removal of coating) and CH=5 representing the worst adhesion (all or almost all of the coating removed).

[0146] For reference, a 22 μm thick UV-curing acrylate-based topcoat was applied and cured, and no primer layer was applied to the substrate before testing in the same manner as above.

[0147] The results are shown in the table below. [Table 11]

[0148] The results in the table above demonstrate the potential for curing dry or nearly dry films on various polymer substrates, as well as the improved adhesion of the films to both the substrate and the subsequent topcoat.

[0149] Example 10, different monomer pairs The following monomers and oligomers were used: AIPE (unsaturated polyester derived from maleic anhydride co-reacted with a polyfunctional alcohol, Sir Industriale, Italy), styrene (Sigma Aldrich), Rapi-Cure DVE-3 (triethylene glycol divinyl ether) "DVE3", SR350D (trimethylolpropane triacrylate, Arkema), APE (pentaerythritol allyl ether, Perstorp Chemicals), BMI1500 (difunctional maleimide, Caplinq) "BMI", Eb2221 (polyfunctional acrylate from Allnex Belgium SA / NV) "Eb2221", SR9020 (trifunctional acrylate, Sartomer), and SR238 (HDDA, hexanediol diacrylate, Arkema). Ten different monomer mixtures were prepared by mixing these monomers and oligomers in weight ratios according to the table below. All 10 monomer mixtures were treated with 2.4 wt% Speedcure-2 ITX (photoinitiator) from Lambson Limited to create 10 corresponding formulations. [Table 12] [Table 13] All percentages are based on weight.

[0150] The above mixture was applied to a 50 μm thick Mitsubishi PET film at a thickness of 1 g / m². 2 Apply and cure according to the table below, where N represents the number of passes under the lamp, and 135 mJ / cm² per pass. 2(UVA). After evaluating the curing state, AD+ (abbreviation for "almost dry plus") indicates the state just before the film is completely dry according to the description of the dryness evaluation in the previous example. The sample was coated with UT7710 (Bona acrylic topcoat) using a 22-micron rod. Measured with UVA using the same apparatus as in the previous example to 1.2 J / cm 2 (UVA) to cure the topcoat.

[0151] The results are shown in the following table. All exposures marked "mJ" in the table refer to "mJ / cm2 (UVA)".

Table 14

[0152] This example shows the applicability of the present invention to several monomer pairs, all of which are characterized by a very large processing window for UV exposure and very good adhesion to PET foil. Formulations 8, 9, and 10 consisting of acrylate oligomers and acrylate monomers with photoinitiators show that when the formulation is cured to an almost dry state, the adhesion between the topcoat and the substrate is insufficient, indicating the drawback of the high rate of homopolymerization of the reactive groups utilized for interlayer adhesion to the topcoat when a dry film is required in the manufacturing process.

[0153] Example 11 The cured and dried formulation X film on a 50-μm-thick Toray PET film prepared according to Example 9 was stored in the dark at room temperature for 5 months. An acrylic topcoat was applied and cured according to Example 9. The results are shown in the following table.

Table 15

[0154] The above example shows that the reactivity towards the acrylic topcoat remains intact after a long storage period at room temperature.

[0155] Example 12 To test the effect of UV radiation dose on the primer (particularly the effect of high UV radiation dose on adhesion to the next coating layer), several different UV radiation doses were tested.

[0156] We used a 2mm thick sheet of white PET (polyethylene terephthalate) called "PET 2mm," purchased from Nordbergs Tekniska AB, cut into small pieces, and used them as the base material. We wiped the pieces clean with dry tissue paper.

[0157] The primer formulation used was "Formulation X," which contained 49.4% by weight of Ebecryl 2221, 49.4% by weight of Rapi-Cure DVE-3, and 1.6% by weight of Speedcure-2 ITX from Lambson Limited.

[0158] A thin layer of "Formulation X" was applied to the substrate as a primer to a thickness of approximately 1 μm (1 g / sqm). The substrate with the primer layer was placed in a curing apparatus including a conveyor belt and a fixed medium-pressure mercury lamp that irradiates with UVA, UVB, UVC, and UVV, and exposed to different UV doses as shown in the table below.

[0159] The surface properties of the primer layer immediately after UV exposure were tested using gloved fingers and a spatula to determine whether the primer layer had hardened. If a gloved finger or spatula left a mark on the primer layer, the surface was determined to be "wet." If a gloved finger or spatula left no mark on the primer layer, the surface was determined to be "dry." If part of the surface was dry and other parts were wet, or if very faint marks were observed, the surface was determined to be "almost dry." These results are shown under "Surface Properties" in the table below.

[0160] Next, a thicker layer of Bona AB's UV-curing acrylate topcoat (UE1664) was applied over the primer layer using a 22 μm rod applicator, and cured in the same apparatus at 1.4 J / cm².2 The UV dose of (UVA) was applied to completely cure and dry the layer.

[0161] The adhesion of the coating layer to the substrate was tested using the standard tape test ("cross-hatch test") according to the cross-cut test described in ISO 2409. Briefly, 25 regions each approximately 1 mm 2 in a square pattern are cut through the coating to the substrate. A tape is pressed onto the coating and quickly pulled off. The resulting damage is evaluated by assessing the amount of coating removed by the tape, with CH = 0 representing the best adhesion (no coating removal) and CH = 5 representing the worst adhesion (all or almost all of the coating is removed).

[0162] For reference, a UV-curable acrylate-based topcoat with a thickness of 22 μm was applied, cured, and no primer layer was applied onto the substrate before testing as described above.

[0163] The results are shown in the following table.

Table 16

[0164] The results in the above table show that the primer can form a film, withstand a large amount of excess UV beyond the amount for film formation, and still provide good adhesion to the topcoat.

[0165] Example 13, several different substrates Several different common plastics were used as substrates, and the following from Norbergs Tekniska AB We obtained PPO (polyphenylene oxide) quality "grayish blue 6mm", ABS (acrylonitrile butadiene styrene copolymer) quality "white 2mm", PVC-XT (extruded polyvinyl chloride) quality "gray 1mm", HIPS (high-impact polystyrene) quality "white 2mm", PEEK (polyether ether ketone) quality "natural calendered 2mm", PMMA (polymethyl methacrylate) "transparent 4mm", and PC (polycarbonate) quality "transparent 1mm".

[0166] The PS (polystyrene) sample was cut from the lid of a large 150mm polystyrene petri dish obtained from VWR.

[0167] A 12 μm thick layer of UT7710 (Bona acrylic topcoat) was applied to a substrate with good adhesion to UT7710, and 1.4 mJ / cm² of medium-pressure mercury lamp was applied. 2 The acrylic surface was prepared by curing it with a dose of UVA.

[0168] The substrate was wiped with lint-free paper before use, but no other cleaning or surface activation was performed. Compound Y was applied in a layer approximately 1 μm thick (1 g / m²). 2 It was applied with ).

[0169] A substrate with a primer layer cured using an apparatus including a Conober belt and a fixed medium-pressure mercury lamp that irradiates UVA, UVB, UVC, and UVV. The substrate with the primer layer is passed through the curing apparatus multiple times, and in each pass the primer and substrate are irradiated at 135 mJ / cm². 2 The subjects were exposed to UVA. After each pass (passes 1-6), the surface properties of the primer were evaluated using gloved fingers and a spatula, in the same manner as in the example above.

[0170] In the table below, "W" is an abbreviation for "wet," "AD" is an abbreviation for "almost dry," "D" is an abbreviation for "dry," and "AD+" is an abbreviation for "almost dry plus," which is a state exactly between "almost dry" and "dry."

[0171] 6 passes or 810 mJ / cm 2 (UVA), all samples were dry or nearly dry, and UT7710 (Bona acrylic topcoat) was applied using a 22 micron rod and cured at 1.4 J / cm 2 (UVA), and crosshatch was evaluated. Another set of samples was subjected to twice the dose (1620 mJ / cm 2 UVA), tested for treatment and crosshatch. As a reference, the substrate was coated with UT7710 without pretreatment of formulation Y, referred to as "without primer" in the table below. The experiments using twice the UV dose and the reference without primer (Y pretreatment) had the same topcoat and were applied in the same way.

[0172] The results are shown in the table below. All exposures marked "mJ" in the table refer to "mJ / cm2 (UVA)".

Table 17

[0173] This example shows good results on some plastics without the need for abrasive, solvent or corona pretreatment. This shows the ability to withstand excessive exposure in most substrate types. The progress of drying also shows a very wide processing window that is resistant to both excessive and insufficient exposure, since the AD state already conforms to many industrial processes.

[0174] Example 14 To test the effect of UV dose on the primer (especially the effect of UV dose on adhesion to the substrate and the next coating layer), several different UV doses were tested.

[0175] Transparent PC (polycarbonate) "PC" with a thickness of 1 mm purchased from Nordbergs Tekniska AB was cut into small pieces and used as the substrate. The pieces were wiped clean with a dry tissue paper.

[0176] The primer formulation used was "Formulation X," which contained 49.4% by weight of Ebecryl 2221, 49.4% by weight of Rapi-Cure DVE-3, and 1.6% by weight of Speedcure-2 ITX from Lambson Limited.

[0177] A thin layer of "Formulation X" was applied to the substrate as a primer to a thickness of approximately 1 μm (1 g / sqm). The substrate with the primer layer was placed in a curing apparatus including a conveyor belt and a fixed medium-pressure mercury lamp that irradiates with UVA, UVB, UVC, and UVV, and exposed to different UV doses as shown in the table below.

[0178] The surface properties of the primer layer immediately after UV exposure were tested using gloved fingers and a spatula to determine whether the primer layer had hardened. If a gloved finger or spatula left a mark on the primer layer, the surface was determined to be "wet." If a gloved finger or spatula left no mark on the primer layer, the surface was determined to be "dry." If part of the surface was dry and other parts were wet, or if very faint marks were observed, the surface was determined to be "almost dry." These results are shown under "Surface Properties" in the table below.

[0179] Next, a thicker layer of Bona AB's UV-curing acrylate topcoat (UE1664) was applied over the primer layer using a 22 μm rod applicator, and cured in the same apparatus at 1.4 J / cm². 2 The layer was completely cured and dried by applying a UV dose of (UVA).

[0180] The adhesion of the coating layer to the substrate was tested using a standard tape test ("cross-hatch test") according to the cross-cut test described in ISO 2409. In short, each was approximately 1 mm 2In a square pattern of 25 areas, cuts were made through the coating to the substrate. The tape was pressed onto the coating and quickly pulled off. The resulting damage was evaluated by assessing the amount of coating removed by the tape, with CH=0 representing the best adhesion (no removal of coating) and CH=5 representing the worst adhesion (all or almost all of the coating removed).

[0181] For reference, a 22 μm thick UV-curing acrylate-based topcoat was applied and cured, and no primer layer was applied to the substrate before testing in the same manner as above.

[0182] The results are shown in the table below. [Table 18]

[0183] The results in the table above indicate that the primer performs well across a wide range of UV radiation levels.

[0184] Example 15 To test the concept of the primer under inert conditions, a sealed Addixx Inert Box (model IB-K162504SR-UF with quartz window from Addixx Specialities, Budingen, Germany) was used. The Addixx Inert Box features a quartz window on the top lid to allow UV irradiation of its contents and two valves to allow purging of atmospheric gas with an inert gas.

[0185] Chemical nitrogen (exceptionally clean nitrogen gas from Linde Industrigaser of Sweden, with less than 5 ppm of O2 and humidity) was connected to an Addixx Inert Box, and downstream of it, another sealed box was placed containing an oxygen detector (a Greisinger GMH3692 oxygen detector with a GGO381 sensor).

[0186] A primer formulation, "Formulation Z," containing 50% by weight Ebecryl 2221 and 50% by weight Rapi-Cure DVE-3 (triethylene glycol divinyl ether) from Allnex Belgium SA / NV was prepared. A thin layer of Formulation Z was applied to a 50 μm thick Toray PET film at a thickness of approximately 1 μm (1 g / sqm). The PET film with the primer layer was placed in an Addixx Inert Box and purged with nitrogen gas for several minutes until the oxygen detector reading was less than 0.5% (less than 5000 ppm), after which the valve was closed. The nitrogen-filled Addixx Inert Box containing the primed PET film was then placed in a curing apparatus containing a conveyor belt and fixed medium-pressure mercury lamps irradiating with UVA, UVB, UVC, and UVV. Different UV doses were tested.

[0187] The surface properties of the primer layer immediately after UV exposure were tested using a gloved finger and a spatula to determine whether the primer layer had hardened. If a gloved finger or spatula left a mark on the primer layer, the surface was determined to be "wet." If a gloved finger or spatula left no mark on the primer layer, the surface was determined to be "dry." If part of the surface was dry and other parts were wet, or if very faint marks were observed, the surface was determined to be "almost dry." If the surface was sticky to the touch of a gloved finger, the surface was determined to be "sticky." These results are shown in the "Surface Properties" column of the table below.

[0188] Next, a thicker layer of Bona AB's UV-curing acrylate topcoat (UT7710) was applied over the primer layer using a 22 μm rod applicator, and cured in the same apparatus under atmospheric conditions at 1.4 J / cm². 2 The layer was completely cured and dried by applying a UV dose of (UVA).

[0189] The adhesion of the coating layer to the substrate was tested using a standard tape test ("cross-hatch test") according to the cross-cut test described in ISO 2409. In short, each was approximately 1 mm2 In a square pattern of 25 areas, cuts were made through the coating to the substrate. The tape was pressed onto the coating and quickly pulled off. The resulting damage was evaluated by assessing the amount of coating removed by the tape, with CH=0 representing the best adhesion (no removal of coating) and CH=5 representing the worst adhesion (all or almost all of the coating removed).

[0190] For reference, a 22 μm thick UV-curable acrylate-based topcoat was applied and cured, and no primer layer was applied to the PET film before testing in the same manner as above.

[0191] The results are shown in the table below. [Table 19]

[0192] The results in the table above indicate that the primer performs well under inert conditions across a wide range of UV radiation levels.

Claims

1. A method for coating a substrate, a) To provide a base material, wherein the base material is - Aromatic group-containing polymers selected from the group consisting of polyethylene terephthalate (PET), polycarbonate (PC), and polystyrene (PS), • Polyetheretherketone (PEEK), - Polyolefins selected from the group consisting of polypropylene (PP) and polyethylene (PE), and • Polymethyl methacrylate (PMMA), Selected from the group consisting of, To provide a substrate in which at least a portion of at least one chemical group selected from the group consisting of aromatic rings, sulfur, and peroxides is present on the surface of the substrate, b) At least a portion of the surface of the substrate, i) A compound comprising at least one carbon-carbon double bond, which may also contain a chemical group capable of abstracting hydrogen, ii) The first monomer M １ and the second monomer M ２ which is a mixture comprising the monomers capable of undergoing a polymerization reaction to form a copolymer covalently bonded to the substrate, and at least one of the ratios r １ and r ２ is less than 0.45, and one of k １１ and k ２２ is at least 10 times greater than the other, provided that when r １ = r ２ = 0, the said conditions regarding k １１ and k ２２ do not apply, except that r １ = k １１ / k １２ and r ２ = k ２２ / k ２１ and In the formula, k １１ is monomer M １ Growing copolymer chain ~ M １ ＊ This is the growth rate constant of the growth reaction applied, In the formula, k １２ is monomer M ２ Growing copolymer chain ~ M １ ＊ This is the growth rate constant of the growth reaction applied, In the formula, k ２１ is monomer M １ Growing copolymer chain ~ M ２ ＊ This is the growth rate constant of the growth reaction applied, In the formula, k ２２ is monomer M ２ Growing copolymer chain ~ M ２ ＊ The growth rate constant of the growth reaction added is the contact with one of the mixtures, First monomer M １ and the second monomer M ２ However, the following options are available: i) M １ It is acrylic, M ２ It is a male art, ii) M １ It is acrylic, M ２ It is vinyl ether, iii) M １ It is methacrylate, M ２ It is vinyl ether, iv) M １ It is acrylic, M ２ It is an allyl ether, v) M １ It is methacrylate, M ２ It is a male art, vi) M １ It is methacrylate, M ２ It is maleimide, vii) M １ It is acrylic, M ２ It is maleimide, viiii) M １ It is vinyl ether, M ２ It is a male art, ix) M １ It is styrene, M ２ It is a Maleart. It is one of them, c) Initiate the reaction using a chemical beam, and the at least one chemical group on the surface of the substrate and i) the compound or ii) the monomer M １ and M ２ Through a reaction with the above, a covalent bond is formed, and as a result, i) a polymer or ii) a copolymer is formed covalently bonded to the surface of the substrate. f) Applying at least one of a coating and a sheet to the surface of the substrate, g) Curing the at least one coating, A method comprising a series of steps.

2. The method according to claim 1, further comprising the step of removing, after step c), at least a portion of the i) compound or ii) the mixture that has not reacted to form a covalent bond.

3. The method according to claim 1 or 2, wherein the surface is treated with at least one selected from the group consisting of corona treatment, plasma treatment and flame treatment prior to step b).

4. The method according to any one of claims 1 to 3, wherein an electron-withdrawing group is present adjacent to the at least one carbon-carbon double bond in the compound.

5. The method according to any one of claims 1 to 4, wherein electron-withdrawing groups are present on both sides of the at least one carbon-carbon double bond in the compound.

6. The method according to claim 1, wherein the ratio (r) of the number of thiol groups to the number of carbon-carbon double bonds in step b) satisfies 0.05 ≤ r ≤ 20.

7. The method according to claim 1, wherein the ratio (r) of the number of thiol groups to the number of carbon-carbon double bonds in step b) satisfies 0.2 ≤ r ≤ 5.

8. The method according to claim 1, wherein the ratio (r) of the number of thiol groups to the number of carbon-carbon double bonds in step b) satisfies one of 0.3 ≤ r ≤ 0.9 and 1.1 ≤ r ≤ 3.

9. The method according to any one of claims 1 to 8, wherein in step b), a Norrish type II photoinitiator is brought into contact with the surface of the substrate.

10. The method according to any one of claims 1 to 9, wherein i) the compound or ii) the mixture to be applied in step b) is provided in an acidic mixture.

11. The method according to any one of claims 1 to 10, wherein all the components added in step b) are provided in a single formulation.

12. The method according to any one of claims 1 to 11, wherein the compound is in contact with at least a portion of the surface of the substrate by inkjet in step b).

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