Vinyl-based polymer, production method therefor, and curable resin composition

Abstract

Provided is a vinyl-based polymer having a crosslinkable functional group. A cured object of the vinyl-based polymer has a recovery of 75% or greater and an elongation at break of 300-600%.

Description

Vinyl polymer, method for producing same, and curable resin composition

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to Japanese Patent Application No. 2023-217244, filed on December 22, 2023, the entire contents of which are incorporated herein by reference. The present disclosure relates to a vinyl polymer, a method for producing the same, and a curable resin composition.

[0002] Vinyl polymers having crosslinkable functional groups are widely known as curable resins used in industrial applications. Vinyl polymers having crosslinkable groups are blended with other components as needed to form curable resin compositions, which are widely used to produce various cured products such as paints, adhesives, pressure-sensitive adhesives, sealants, molding materials, and rubber sheets.

[0003] Patent Document 1 discloses a vinyl polymer having crosslinkable silyl groups at both ends, obtained by living radical polymerization, as a vinyl polymer to be blended in a curable resin composition for producing a cured product.

[0004] Japanese Patent Application Publication No. 11-130931

[0005] In recent years, with the improvement in the durability of buildings themselves, there has been a demand for high levels of tensile properties, heat resistance, and weather resistance in sealants used in buildings. In particular, in applications where outdoor use is expected, such as construction applications, it is desirable that the cured product (particularly the surface) obtained by curing a curable resin composition has weather resistance (hereinafter also referred to as "dynamic weather resistance") that can withstand dynamic deformation of the cured product itself due to temperature, humidity, etc.

[0006] The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a vinyl polymer from which a cured product having excellent tensile properties, heat resistance, and weather resistance can be obtained.

[0007] As a result of intensive studies to solve the above problems, the present inventors have found that a vinyl polymer having a crosslinkable functional group, the physical properties of which fall within specific ranges in a cured product of the vinyl polymer, can provide a cured product excellent in tensile properties, heat resistance, and weather resistance (particularly dynamic weather resistance). Specifically, the present disclosure provides the following vinyl polymer, a method for producing the same, and a curable resin composition.

[0008] [1] A vinyl polymer having crosslinkable functional groups, wherein the cured product of the vinyl polymer has a recovery rate of 75% or more and a breaking elongation of 300 to 600%. [2] The vinyl polymer of [1], wherein the average number of the crosslinkable functional groups per molecule is 1.8 or more. [3] The vinyl polymer of [1] or [2], wherein structural units derived from a (meth)acrylic acid alkyl ester having an alkyl group containing 10 or more carbon atoms in the ester moiety account for 0.1 to 50% by mass of all structural units constituting the vinyl polymer. [4] The vinyl polymer of any of [1] to [3], wherein the proportion of structural units derived from a (meth)acrylic acid alkyl ester having an alkyl group containing 2 or less carbon atoms in the ester moiety is 20% by mass or less of all structural units constituting the vinyl polymer. [5] The vinyl polymer according to [1] or [2], which contains structural units derived from an alkyl (meth)acrylate ester having an alkyl group with 10 or more carbon atoms in the ester moiety in an amount of 0.1 to 50 mass % based on all structural units constituting the vinyl polymer, and the proportion of structural units derived from an alkyl (meth)acrylate ester having an alkyl group with 2 or less carbon atoms in the ester moiety is 20 mass % or less based on all structural units constituting the vinyl polymer. [6] The vinyl polymer according to any of [1] to [5], which is a block copolymer consisting of polymer block (A) / polymer block (B) / polymer block (A). [7] The vinyl polymer according to [6], wherein the polymer block (A) has the crosslinkable functional group. [8] The vinyl polymer according to [1] to [7], which has a weight average molecular weight (Mw) of 30,000 to 100,000 and a molecular weight distribution (Mw / Mn) of 1.80 or less. [9] A curable resin composition containing the vinyl polymer of any one of [1] to [8] and an oxyalkylene polymer having a crosslinkable silyl group.

[10] The curable resin composition of [9], wherein the mass ratio of the vinyl polymer to the oxyalkylene polymer is 10 / 90 to 90 / 10, expressed as vinyl polymer / oxyalkylene polymer.

[11] The curable resin composition of [9] or

[10] , which is used for a sealant, an adhesive, a pressure-sensitive adhesive, or a paint.

[0009]

[12] The method for producing a vinyl polymer according to any one of [1] to [8], comprising a polymerization step of polymerizing a vinyl monomer, wherein the vinyl monomer comprises a vinyl monomer having a crosslinkable functional group, and in the polymerization step, polymerization is carried out while continuously or intermittently supplying into a reactor at least a part of the total amount of the vinyl monomer having a crosslinkable functional group used in the production of the vinyl polymer.

[13] The method for producing a vinyl polymer according to

[12] , wherein the vinyl polymer is produced by living radical polymerization.

[0010]

[14] A method for producing a vinyl polymer having a crosslinkable functional group, wherein the vinyl polymer is a block copolymer consisting of polymer block (A) / polymer block (B) / polymer block (A), and the average number of crosslinkable functional groups per molecule is 1.8 or more, the method comprising: a first polymerization step of polymerizing a vinyl monomer in the presence of a living radical polymerization controller and a polymerization initiator to obtain the polymer block (A); and a second polymerization step of polymerizing a vinyl monomer in the presence of the polymer block (A) obtained in the first polymerization step and the polymerization initiator to form the polymer block (B), wherein the vinyl monomer used in the first polymerization step includes a vinyl monomer having a crosslinkable functional group, and the first polymerization step is carried out while continuously or intermittently supplying at least a portion of the total amount of the vinyl monomer having a crosslinkable functional group used to produce the polymer block (A) into a reactor.

[15] The method for producing a vinyl polymer according to

[14] , wherein the living radical polymerization controller is a chain exchange transfer polymerization controller.

[16] The method for producing a vinyl polymer according to

[14] or

[15] , wherein the ratio of the vinyl monomer having a crosslinkable functional group to be continuously or intermittently fed into a reactor is 10 to 100 mass % based on the total amount of the vinyl monomer having a crosslinkable functional group used in producing the polymer block (A).

[0011] According to the vinyl polymer of the present disclosure, it is possible to obtain a cured product that exhibits excellent tensile properties, heat resistance, and weather resistance (particularly dynamic weather resistance).

[0012] The present disclosure will be described in detail below. In this specification, "(meth)acrylic" means acrylic and / or methacrylic. "(meth)acrylate" means acrylate and / or methacrylate. "(meth)acryloyl" means acryloyl and / or methacryloyl.

[0013] <Vinyl Polymer> The vinyl polymer of the present disclosure (hereinafter also simply referred to as "vinyl polymer") is a polymer that has a crosslinkable functional group, and a recovery rate of a cured product of the polymer of 75% or more, and a breaking elongation of 300 to 600%.

[0014] (Crosslinkable Functional Group) Examples of the crosslinkable functional group possessed by the vinyl polymer include a crosslinkable silyl group, a silanol group, a carboxyl group, a hydroxyl group, an epoxy group, an oxazoline group, an isocyanate group, and a polymerizable unsaturated group. Among these, the crosslinkable functional group possessed by the vinyl polymer is preferably a crosslinkable silyl group, in that it can provide a cured product obtained using the vinyl polymer with better elongation at break and strength at break, and it is easy to control the reactivity.

[0015] Examples of crosslinkable silyl groups include alkoxysilyl groups and halogenosilyl groups. Specific examples of these include trimethoxysilyl groups, triethoxysilyl groups, triisopropoxysilyl groups, tris(2-propenyloxy)silyl groups, methyldimethoxysilyl groups, diethoxymethylsilyl groups, ethyldiethoxysilyl groups, diisopropoxymethylsilyl groups, (chloromethyl)dimethoxysilyl groups, and (ethoxymethyl)dimethoxysilyl groups. Of these, alkoxysilyl groups are preferred because they exhibit good reactivity and high storage stability.

[0016] The crosslinkable silyl group as a whole can be regarded as one reaction point. Therefore, in this specification, the entire crosslinkable silyl group is considered to be one crosslinkable functional group. For example, vinyltrimethoxysilane is a vinyl monomer having a trimethoxysilyl group as the crosslinkable functional group, and the number of crosslinkable functional groups in one molecule is one. Furthermore, vinylmethyldimethoxysilane is a vinyl monomer having a methyldimethoxysilyl group as the crosslinkable functional group, and the number of crosslinkable functional groups in one molecule is one.

[0017] (Restoration Rate) A vinyl polymer has a restoration rate of 75% or more when cured. Here, the restoration rate of a cured vinyl polymer refers to the ratio of the strain recovered after removing a load to the strain when a load is applied to the cured vinyl polymer for a certain period of time and the cured vinyl polymer is stretched. That is, it is possible to apply a load to a cured vinyl polymer for a certain period of time and stretch the cured vinyl polymer, and after removing the load, the behavior of at least a part of the strain of the cured vinyl polymer is observed, so that the restoration rate of the cured vinyl polymer can be determined. Specifically, the gauge length [mm] before stretching is expressed as L ０ The distance between the gauge lines [mm] when stretched by applying a load for a certain period of time is L １ The distance between the gauge lines [mm] after removing the load is L ２ In this case, the restoration rate (unit: %) of the cured product is expressed by the following formula (1): １ -L ２ ) / (L １ -L ０ ) × 100 … (1)

[0018] The restoration rate expressed by the above mathematical formula (1) can be used as an index of the rubber elasticity of a vinyl polymer. That is, the higher the restoration rate of a cured vinyl polymer, the higher the rubber elasticity of the vinyl polymer can be evaluated. The restoration rate of a cured vinyl polymer can be adjusted to a desired range by controlling the average number of crosslinkable functional groups per vinyl polymer molecule, the type of crosslinkable functional group, and the position at which the crosslinkable functional group is introduced. Details of the method for measuring the restoration rate of a cured product follow the method described in the Examples below.

[0019] When the recovery rate of a cured product of a vinyl polymer, expressed by the above formula (1), is less than 75%, the weather resistance of the cured product obtained using a curable resin composition containing the vinyl polymer is insufficient. From the viewpoint of obtaining a cured product exhibiting good weather resistance (particularly dynamic weather resistance), the recovery rate of the cured product of the vinyl polymer is preferably 76% or more, more preferably 78% or more, and even more preferably 80% or more. When the recovery rate is within the above range, even if the cured product repeatedly expands and contracts due to environmental changes such as temperature and humidity, the occurrence of cracks and wrinkles in the cured product due to such expansion and contraction can be effectively suppressed. The upper limit of the recovery rate is not particularly limited, and is a value of 100% or less.

[0020] (Elongation at break) The breaking elongation of the cured product obtained by curing the vinyl polymer is 300 to 600%. If the breaking elongation of the cured product of the vinyl polymer is less than 300%, the cured product will have poor flexibility. Therefore, for example, when the vinyl polymer is applied as a sealant for an exterior wall material, the cured product (sealant) will be unable to follow the expansion and contraction of the exterior wall material (more specifically, fluctuations in joint width) due to vibration, temperature, humidity, etc., and as a result, cracks and wrinkles will easily occur in the cured product. Furthermore, if the breaking elongation of the cured product of the vinyl polymer exceeds 600%, the strength of the cured product will decrease. From the viewpoint of achieving a well-balanced improvement in the weather resistance (particularly dynamic weather resistance) and strength of the cured product, the breaking elongation of the cured product of the vinyl polymer is preferably 305% or more, more preferably 310% or more. The breaking elongation of the cured vinyl polymer is preferably 550% or less, more preferably 500% or less, and even more preferably 450% or less. The breaking elongation of the cured vinyl polymer is a value measured in accordance with JIS K 6251:2017. The breaking elongation of the cured vinyl polymer can also be adjusted to a desired range by controlling the average number of crosslinkable functional groups per vinyl polymer molecule, the type of crosslinkable functional group, and the introduction position of the crosslinkable functional group. Details of the measurement method follow the method described in the Examples below.

[0021] Herein, the "cured product of a vinyl polymer" which is the object (i.e., test piece) for measuring the recovery rate and elongation at break is a cured product obtained by using the vinyl polymer alone or from a composition containing the vinyl polymer and not containing any component other than a solvent and a curing component (specifically, a crosslinking agent and a curing catalyst, which will be described later) in order to evaluate the recovery rate and elongation at break of the vinyl polymer itself. In terms of ease of formation of a cured product, a cured product formed from a composition consisting of a vinyl polymer and a curing component, or a composition consisting of a vinyl polymer, a solvent, and a curing component can be preferably used as the cured product of the vinyl polymer.

[0022] For example, in the case of a vinyl polymer having a crosslinkable silyl group as the crosslinkable functional group, a cured product formed from a composition consisting of a vinyl polymer having a crosslinkable silyl group and a curing catalyst, or a composition consisting of a vinyl polymer having a crosslinkable silyl group, a curing catalyst, and a solvent, is used as the test piece. In this case, the amount of curing catalyst can be appropriately set, but can be, for example, 0.3 to 3.0 parts by mass per 100 parts by mass of the vinyl polymer having a crosslinkable silyl group. The details of the procedure for preparing the specimen for measuring the recovery rate and elongation at break follow the method described in the Examples below.

[0023] The vinyl polymer of the present disclosure is not particularly limited as long as it has a crosslinkable functional group, and the cured product has a recovery rate of 75% or more and a breaking elongation of 300 to 600%, and the type and structure of the monomer constituting the vinyl polymer are not particularly limited. Preferred embodiments of the vinyl polymer of the present disclosure will be described in detail below.

[0024] (Monomer) As the monomer constituting the vinyl polymer, a vinyl monomer having a crosslinkable functional group (hereinafter also referred to as a "crosslinkable group-containing vinyl monomer") is preferably used, since a vinyl polymer having a crosslinkable functional group can be easily obtained.

[0025] Specific examples of the crosslinkable group-containing vinyl monomer include crosslinkable silyl group-containing vinyl compounds, unsaturated carboxylic acids, unsaturated acid anhydrides, hydroxy group-containing vinyl compounds, epoxy group-containing vinyl compounds, primary or secondary amino group-containing vinyl compounds, oxazoline group-containing vinyl compounds, and isocyanate group-containing vinyl compounds, etc. The crosslinkable group-containing vinyl monomer may be one of these or two or more of them.

[0026] Examples of the crosslinkable silyl group-containing vinyl compound include vinyl silanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, and vinyldimethylmethoxysilane; trimethoxysilylpropyl (meth)acrylate, triethoxysilylpropyl (meth)acrylate, methyldimethoxysilylpropyl (meth)acrylate, dimethylmethoxysilylpropyl (meth)acrylate, trimethoxysilylmethyl (meth)acrylate, methyldimethoxysilylmethyl (meth)acrylate, and 8-(trimethoxysilyl) (meth)acrylate. )octyl and other alkoxysilyl group-containing (meth)acrylic acid esters; aromatic vinyl group-containing alkoxysilanes such as p-styryltrimethoxysilane, p-styrylmethyldimethoxysilane, p-styryldimethylmethoxysilane, p-styryltriethoxysilane, p-styrylmethyldiethoxysilane, and p-styryldimethylethoxysilane; alkoxysilyl group-containing vinyl ethers such as trimethoxysilylpropyl vinyl ether; and alkoxysilyl group-containing vinyl esters such as vinyl trimethoxysilylundecanoate. Crosslinkable silyl group-containing vinyl compounds are suitable in that they form a crosslinked structure by dehydration condensation between crosslinkable silyl groups, allowing efficient polymerization reactions and subsequent crosslinking reactions when producing a vinyl polymer.

[0027] Examples of unsaturated carboxylic acids include (meth)acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, cinnamic acid, and monoalkyl esters of unsaturated dicarboxylic acids (monoalkyl esters of maleic acid, fumaric acid, itaconic acid, citraconic acid, etc.). Examples of unsaturated acid anhydrides include maleic anhydride, itaconic anhydride, citraconic anhydride, etc.

[0028] Examples of hydroxy group-containing vinyl compounds include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and mono(meth)acrylic acid esters of polyalkylene glycols (e.g., polyethylene glycol, polypropylene glycol, etc.). Examples of epoxy group-containing vinyl compounds include glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth)acrylate.

[0029] Examples of the primary or secondary amino group-containing vinyl compound include amino group-containing (meth)acrylic acid esters such as aminoethyl(meth)acrylate, aminopropyl(meth)acrylate, N-methylaminoethyl(meth)acrylate, and N-ethylaminoethyl(meth)acrylate; and amino group-containing (meth)acrylamides such as aminoethyl(meth)acrylamide, aminopropyl(meth)acrylamide, N-methylaminoethyl(meth)acrylamide, and N-ethylaminoethyl(meth)acrylamide.

[0030] Examples of the oxazoline group-containing vinyl compound include 2-isopropenyl-2-oxazoline, 2-vinyl-2-oxazoline, etc. Examples of the isocyanate group-containing vinyl compound include 2-isocyanatoethyl (meth)acrylate, (meth)acryloyl isocyanate, etc.

[0031] Of these, the crosslinkable group-containing vinyl monomer is preferably a crosslinkable silyl group-containing vinyl compound, since it can give a cured product that is excellent in elongation at break and strength at break and also exhibits good weather resistance.

[0032] The average number of crosslinkable functional groups per molecule of the vinyl polymer is preferably 1.8 or more. When the average number of crosslinkable functional groups per molecule of the vinyl polymer is 1.8 or more, the recovery rate of the cured product of the vinyl polymer can be increased, and the weather resistance (particularly dynamic weather resistance) of the cured product obtained using the curable resin composition can be further improved. From this viewpoint, the average number of crosslinkable functional groups per molecule of the vinyl polymer is more preferably 2.0 or more, even more preferably 2.2 or more, even more preferably 2.4 or more, even more preferably 2.7 or more, and even more preferably 3.0 or more. Furthermore, in order to improve the elongation at break of the cured product obtained using the curable resin composition, the average number of crosslinkable functional groups per molecule of the vinyl polymer is preferably 8.0 or less, more preferably 7.0 or less, even more preferably 6.0 or less, and even more preferably 5.5 or less.

[0033] The preferred range of the average number of crosslinkable functional groups per molecule in the vinyl polymer can be set by appropriately combining the above-mentioned upper and lower limits. Specifically, the average number of crosslinkable functional groups per molecule in the vinyl polymer is preferably 1.8 to 8.0, more preferably 2.0 to 7.0, even more preferably 2.2 to 6.0, and still more preferably 2.4 to 5.5.

[0034] The average number of crosslinkable functional groups in the vinyl polymer is １ For example, when determining the average number of crosslinkable functional groups in a vinyl polymer having crosslinkable silyl groups as crosslinkable functional groups, first, the structural units constituting the polymer are identified, and the monomers used in the polymerization are determined. １The polymer composition and the molar fraction of the crosslinkable silyl group-containing monomer are calculated from the integral of the signal at around 3.5 ppm in the H-NMR spectrum, which is derived from a hydrogen atom bonded to a carbon atom of the alkoxysilane. The average number of crosslinkable silyl groups per molecule can then be calculated by multiplying this molar fraction by the number average molecular weight (Mn) obtained by GPC measurement.

[0035] The vinyl polymer may contain a structural unit derived from a crosslinkable group-containing vinyl monomer (hereinafter also referred to as a "crosslinkable group-containing vinyl unit") as well as a structural unit derived from a vinyl monomer other than the crosslinkable group-containing vinyl monomer (hereinafter also referred to as an "other vinyl monomer"). The other vinyl monomer is not particularly limited as long as it is a monomer copolymerizable with the crosslinkable group-containing vinyl monomer. Specific examples of the other vinyl monomer include (meth)acrylic acid alkyl ester compounds, (meth)acrylic acid aliphatic cyclic ester compounds, (meth)acrylic acid aromatic ester compounds, and compounds represented by the following formula (1): CH ２ =CR １ -C(=O)O-(R ２ O) ｎ -R ３ ...(1) (In formula (1), R １ represents a hydrogen atom or a methyl group, R ２ represents a linear or branched alkylene group having 2 to 6 carbon atoms; R ３ represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms. n represents an integer of 1 to 100.) Examples of suitable monomers include compounds represented by the formula (I), styrene-based compounds, maleimide compounds, amide group-containing vinyl compounds, and fluorine-containing (meth)acrylic acid ester compounds. The other monomer constituting the vinyl polymer may be one or more of these.

[0036] Specific examples of the (meth)acrylic acid alkyl ester compound include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, and icosyl (meth)acrylate.

[0037] Specific examples of the aliphatic cyclic ester compound of (meth)acrylic acid include cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentanyl (meth)acrylate.

[0038] Specific examples of aromatic ester compounds of (meth)acrylic acid include phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxymethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, and 3-phenoxypropyl (meth)acrylate.

[0039] Regarding the compound represented by formula (1), when n in formula (1) is 1, the compound represented by formula (1) has an oxyalkylene structure such as an oxyethylene chain, an oxypropylene chain, or an oxybutylene chain. Specific examples of the compound in which n in formula (1) is 1 (i.e., a (meth)acrylic acid alkoxyalkyl ester compound) include methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, n-propoxyethyl (meth)acrylate, n-butoxyethyl (meth)acrylate, methoxypropyl (meth)acrylate, ethoxypropyl (meth)acrylate, n-propoxypropyl (meth)acrylate, n-butoxypropyl (meth)acrylate, methoxybutyl (meth)acrylate, ethoxybutyl (meth)acrylate, n-propoxybutyl (meth)acrylate, and n-butoxybutyl (meth)acrylate.

[0040] When n in the above formula (1) is 2 or more, the compound represented by the above formula (1) has a polyoxyalkylene structure such as a polyoxyethylene chain, a polyoxypropylene chain, or a polyoxybutylene chain. ２ may be the same or different from each other. That is, a compound in which n in the above formula (1) is 2 or more may have different types of polyoxyalkylene structures in one molecule, such as a block structure consisting of polyoxyethylene / polyoxypropylene.

[0041] Specific examples of the compound in which n in the above formula (1) is 2 or more include polyoxyethylene (meth)acrylate, polyoxypropylene (meth)acrylate, polyoxybutylene (meth)acrylate, polyoxyethylene-polyoxypropylene (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, lauroxypolyethylene glycol (meth)acrylate, stearoxypolyethylene glycol (meth)acrylate, octoxypolyethylene glycol polypropylene glycol (meth)acrylate, nonylphenoxypolypropylene glycol (meth)acrylate, and phenoxypolyethylene glycol polypropylene glycol (meth)acrylate.

[0042] Specific examples of the styrene-based compound include styrene, α-methylstyrene, β-methylstyrene, vinylxylene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, p-n-butylstyrene, p-isobutylstyrene, p-t-butylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, p-isopropenylphenol, m-isopropenylphenol, o-isopropenylphenol, o-vinylbenzoic acid, m-vinylbenzoic acid, p-vinylbenzoic acid, divinylbenzene, and vinylnaphthalene.

[0043] Specific examples of the maleimide compound include maleimide and N-substituted maleimide compounds. Examples of the N-substituted maleimide compound include N-alkyl-substituted maleimide compounds such as N-methylmaleimide, N-ethylmaleimide, N-n-propylmaleimide, N-isopropylmaleimide, N-n-butylmaleimide, N-isobutylmaleimide, N-tert-butylmaleimide, N-pentylmaleimide, N-hexylmaleimide, N-heptylmaleimide, N-octylmaleimide, N-laurylmaleimide, and N-stearylmaleimide; N-cyclopentylmaleimide; N-cycloalkyl-substituted maleimide compounds such as N-cyclohexylmaleimide and N-cycloalkyl-substituted maleimide compounds such as N-phenylmaleimide, N-(4-hydroxyphenyl)maleimide, N-(4-acetylphenyl)maleimide, N-(4-methoxyphenyl)maleimide, N-(4-ethoxyphenyl)maleimide, N-(4-chlorophenyl)maleimide, N-(4-bromophenyl)maleimide, and N-benzylmaleimide.

[0044] Specific examples of amide group-containing vinyl compounds include (meth)acrylamide, (meth)acrylamide derivatives, and N-vinylamide monomers. Of these, specific examples of (meth)acrylamide derivatives include tert-butyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, and (meth)acryloylmorpholine. Specific examples of N-vinylamide monomers include N-vinylacetamide, N-vinylformamide, and N-vinylisobutylamide.

[0045] Specific examples of the fluorine-containing (meth)acrylic acid ester compound include trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate, perfluoroethylene, perfluoropropylene, and vinylidene fluoride.

[0046] In addition to the above, other vinyl monomers include, for example, vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate; alkenes such as ethylene and propylene; conjugated dienes such as butadiene and isoprene; vinyl chloride, vinylidene chloride, allyl chloride, and allyl alcohol.

[0047] The other vinyl monomer preferably includes a (meth)acrylic acid alkyl ester compound, since it is easy to obtain a vinyl-based polymer having a low Tg and excellent fluidity. As the (meth)acrylic acid alkyl ester compound, a (meth)acrylic acid alkyl ester in which the alkyl group (R) contained in the ester moiety (-COOR) has 1 to 20 carbon atoms can be preferably used, since it is easy to obtain a vinyl-based polymer having a low glass transition temperature (Tg) and excellent fluidity. The (meth)acrylic acid alkyl ester compound constituting the vinyl-based polymer is more preferably a (meth)acrylic acid alkyl ester having an alkyl group having 2 to 20 carbon atoms in the ester moiety, even more preferably a (meth)acrylic acid alkyl ester having an alkyl group having 2 to 18 carbon atoms in the ester moiety, and even more preferably a (meth)acrylic acid alkyl ester having an alkyl group having 4 to 18 carbon atoms in the ester moiety. Furthermore, the vinyl-based polymer preferably includes a structural unit derived from an acrylic monomer, and more preferably includes a structural unit derived from an acrylic acid alkyl ester compound, since it can be a polymer having excellent weather resistance and fluidity.

[0048] In the vinyl polymer, from the viewpoint of obtaining a vinyl polymer having excellent fluidity, the proportion of structural units derived from a (meth)acrylic acid alkyl ester compound is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, still more preferably 85% by mass or more, and even more preferably 90% by mass or more, based on the total structural units constituting the vinyl polymer. Note that the (meth)acrylic acid acrylic ester compound constituting the vinyl polymer may be one type or two or more types.

[0049] In consideration of the mechanical properties of the vinyl polymer, the vinyl polymer preferably has a structural unit derived from a (meth)acrylic acid alkyl ester having an alkyl group in the ester moiety with 4 to 18 carbon atoms. From the viewpoint of achieving both fluidity and mechanical properties of the vinyl polymer, in the (meth)acrylic acid alkyl ester having an alkyl group in the ester moiety with 4 to 18 carbon atoms, the number of carbon atoms in the alkyl group in the ester moiety is preferably 4 to 16, and more preferably 4 to 15.

[0050] In the vinyl polymer, the proportion of structural units derived from a (meth)acrylic acid alkyl ester having an alkyl group having 4 to 18 carbon atoms in the ester moiety is preferably 25% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, still more preferably 50% by mass or more, and even more preferably 60% by mass or more, based on all structural units constituting the vinyl polymer, from the viewpoint of obtaining a vinyl polymer that exhibits fluidity and excellent mechanical properties.

[0051] In particular, in terms of facilitating the production of a vinyl polymer having a low Tg and excellent fluidity, it is preferable that the vinyl polymer contain a structural unit derived from a (meth)acrylic acid alkyl ester having an alkyl group having 10 or more carbon atoms in the ester moiety. By using a vinyl polymer having a low Tg and excellent fluidity as a component of a curable resin composition, the workability of the curable resin composition can be improved. Furthermore, by containing a structural unit derived from a (meth)acrylic acid alkyl ester having an alkyl group having 10 or more carbon atoms in the ester moiety, when a polymer different from the vinyl polymer (e.g., a polyoxyalkylene polymer, hereinafter also referred to as "other polymer") is blended into the curable resin composition during the preparation of the curable resin composition containing the vinyl polymer, compatibility with the other polymer can be improved. This is advantageous in that the mechanical properties of the cured product obtained from the curable resin composition can be improved.

[0052] When the vinyl polymer contains a structural unit derived from an alkyl (meth)acrylate having an alkyl group having 10 or more carbon atoms in the ester moiety, a (meth)acrylate alkyl ester having an alkyl group having 10 to 18 carbon atoms in the ester moiety can be preferably used as the alkyl (meth)acrylate constituting the structural unit, from the viewpoint of ensuring the fluidity of the vinyl polymer.

[0053] In the vinyl polymer, the proportion of structural units derived from a (meth)acrylic acid alkyl ester having an alkyl group with 10 or more carbon atoms in the ester moiety is preferably 0.1% by mass or more, more preferably 1.0% by mass or more, even more preferably 2% by mass or more, even more preferably 5% by mass or more, still more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on all structural units constituting the vinyl polymer. From the viewpoint of improving the fluidity of the vinyl polymer, the proportion of structural units derived from a (meth)acrylic acid alkyl ester having an alkyl group with 10 or more carbon atoms in the ester moiety is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, based on all structural units constituting the vinyl polymer.

[0054] A preferred range of the proportion of structural units derived from a (meth)acrylic acid alkyl ester having an alkyl group with 10 or more carbon atoms in the ester moiety in the vinyl polymer can be set by appropriately combining the above-mentioned upper and lower limits. Specifically, the proportion of structural units derived from a (meth)acrylic acid alkyl ester having an alkyl group with 10 or more carbon atoms in the ester moiety in the vinyl polymer is preferably 0.1 to 50 mass%, more preferably 1.0 to 45 mass%, even more preferably 2 to 40 mass% or more, and even more preferably 5 to 40 mass% or more, based on the total structural units constituting the vinyl polymer.

[0055] In order to appropriately increase the viscosity of the vinyl polymer, it is preferable that the vinyl polymer contain a relatively small proportion of structural units derived from (meth)acrylic acid alkyl esters having an alkyl group with 2 or less carbon atoms in the ester moiety, such as methyl (meth)acrylate and ethyl (meth)acrylate. Specifically, in the vinyl polymer, the proportion of structural units derived from (meth)acrylic acid alkyl esters having an alkyl group with 2 or less carbon atoms in the ester moiety is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 2% by mass or less, and even more preferably 1% by mass or less, based on the total structural units constituting the vinyl polymer. Note that the vinyl polymer may not contain structural units derived from (meth)acrylic acid alkyl esters having an alkyl group with 2 or less carbon atoms in the ester moiety. That is, the proportion of structural units derived from (meth)acrylic acid alkyl esters having an alkyl group with 2 or less carbon atoms in the ester moiety in the vinyl polymer may be 0% by mass.

[0056] The vinyl polymer is particularly suitable in that it contains structural units derived from (meth)acrylic acid alkyl esters having an alkyl group with 10 or more carbon atoms in the ester moiety in an amount of 0.1 to 50 mass % relative to all structural units constituting the vinyl polymer, and the proportion of structural units derived from (meth)acrylic acid alkyl esters having an alkyl group with 2 or less carbon atoms in the ester moiety is 20 mass % or less relative to all structural units constituting the vinyl polymer, thereby ensuring the fluidity (i.e., low viscosity) of the vinyl polymer and improving workability, while also enabling the cured product obtained from the curable resin composition containing the vinyl polymer to have excellent tensile properties, weather resistance, and heat resistance.

[0057] The method for introducing a crosslinkable functional group is not limited to the method of polymerizing a crosslinkable group-containing vinyl monomer, and other methods may also be used. Examples of other methods for introducing a crosslinkable functional group include the following methods 1 and 2. Method 1: A method in which a structural unit derived from an unsaturated carboxylic acid is introduced into a vinyl polymer, and a carboxyl group in the structural unit derived from the unsaturated carboxylic acid is reacted (addition reaction) with a crosslinkable group-containing epoxy compound (preferably a crosslinkable silyl group-containing epoxy compound). Method 2: A method in which a structural unit derived from an epoxy group-containing vinyl compound is introduced into a vinyl polymer, and an epoxy group in the structural unit derived from the epoxy group-containing vinyl compound is reacted (addition reaction) with a crosslinkable group-containing amine compound (preferably a crosslinkable silyl group-containing amine compound).

[0058] (Molecular Weight Characteristics) The polystyrene-equivalent number average molecular weight (Mn) of the vinyl polymer measured by GPC is preferably in the range of 10,000 to 300,000. An Mn of 10,000 or more is preferable in that when a cured product is produced from the vinyl polymer, the strength, weather resistance, and heat resistance of the cured product can be sufficiently increased. Furthermore, an Mn of the vinyl polymer of 300,000 or less can ensure good fluidity and coatability.

[0059] From the viewpoint of the strength, weather resistance, and heat resistance of the cured product, the Mn of the vinyl polymer is more preferably 15,000 or more, even more preferably 20,000 or more, still more preferably 25,000 or more, and even more preferably 30,000 or more. From the viewpoint of ensuring the flowability of the polymer, the upper limit of the Mn of the vinyl polymer is more preferably 200,000 or less, even more preferably 150,000 or less, still more preferably 100,000 or less, and even more preferably 70,000 or less. The preferred range of Mn of the vinyl polymer is more preferably 15,000 to 200,000, even more preferably 20,000 to 150,000, still more preferably 25,000 to 90,000, and even more preferably 30,000 to 70,000.

[0060] Furthermore, the vinyl polymer preferably has a weight average molecular weight (Mw) in terms of polystyrene measured by GPC in the range of 15,000 to 300,000. When the Mw is 15,000 or more, when a cured product is produced from the vinyl polymer, the strength, weather resistance, and heat resistance of the cured product can be sufficiently high. When the Mw of the vinyl polymer is 300,000 or less, good fluidity and coatability can be ensured.

[0061] From the viewpoint of the strength, weather resistance, and heat resistance of the cured product, the Mw of the vinyl polymer is more preferably 20,000 or more, even more preferably 25,000 or more, still more preferably 30,000 or more, and even more preferably 35,000 or more. From the viewpoint of ensuring the flowability of the polymer, the upper limit of the Mw of the vinyl polymer is more preferably 200,000 or less, even more preferably 150,000 or less, and even more preferably 100,000 or less. The preferred range of the Mw of the vinyl polymer is more preferably 20,000 to 200,000, even more preferably 20,000 to 150,000, still more preferably 30,000 to 150,000, and even more preferably 30,000 to 100,000.

[0062] For vinyl polymers, the molecular weight distribution (Mw / Mn) obtained by dividing the weight average molecular weight (Mw) by the number average molecular weight (Mn) is preferably 1.90 or less, more preferably 1.85 or less, even more preferably 1.80 or less, even more preferably 1.75 or less, still more preferably 1.70 or less, and still more preferably 1.65 or less, from the viewpoint of obtaining a cured product excellent in tensile properties (elongation at break, strength at break, etc.) and weather resistance. The lower limit of the molecular weight distribution (Mw / Mn) is not particularly limited, but may be, for example, 1.05 or more, or 1.10 or more.

[0063] (Viscosity) The viscosity of the vinyl polymer is preferably 50 to 1000 Pa·s. When the vinyl polymer has a viscosity within the above range, it can be a polymer with high mechanical strength while having good fluidity and coatability. From the viewpoint of obtaining a polymer with sufficiently high mechanical strength, the viscosity of the vinyl polymer is more preferably 60 Pa·s or more, even more preferably 70 Pa·s or more, even more preferably 80 Pa·s or more, and even more preferably 90 Pa·s or more. Furthermore, from the viewpoint of ensuring fluidity and coatability, the viscosity is more preferably 900 Pa·s or less, even more preferably 800 Pa·s or less, and even more preferably 600 Pa·s or less. The viscosity of the vinyl polymer is a value measured using an E-type viscometer at 25°C. Details of the viscosity measurement method follow the method described in the Examples below.

[0064] (Structure of vinyl polymer) The order of monomer arrangement in the vinyl polymer is not particularly limited. The vinyl polymer may be any of a random copolymer, a block copolymer, an alternating copolymer, and a graft copolymer. Among these, the vinyl polymer is preferably a block copolymer, since it is easy to control the position at which the crosslinkable functional group is introduced, and therefore it is easy to obtain a cured product excellent in tensile properties, weather resistance, and heat resistance.

[0065] (Block Copolymer) When the vinyl polymer of the present disclosure is a block copolymer, the block copolymer (hereinafter also simply referred to as "block copolymer") may have two or more polymer blocks having different polymer compositions, and its structure is not particularly limited. A preferred example of the block copolymer is a vinyl polymer having a polymer block (A) having a crosslinkable functional group and a polymer block (B) having a different polymer composition from that of the polymer block (A).

[0066] Polymer Block (A) Examples of monomers constituting the polymer block (A) include the compounds exemplified as specific examples of monomers constituting vinyl polymers. Among these, the polymer block (A) preferably has a structural unit derived from a (meth)acrylic acid alkyl ester compound, and more preferably has at least a structural unit derived from a (meth)acrylic acid alkyl ester having an alkyl group having 2 to 18 carbon atoms.

[0067] In the polymer block (A), the proportion of structural units derived from (meth)acrylic acid alkyl ester compounds is preferably 50% by mass or more relative to all structural units constituting the polymer block (A), from the viewpoint of obtaining a vinyl polymer having excellent mechanical properties and excellent weather resistance. From this viewpoint, the proportion of structural units derived from (meth)acrylic acid alkyl ester compounds in the polymer block (A) is more preferably 55% by mass or more, even more preferably 60% by mass or more, and even more preferably 70% by mass or more. The upper limit of the proportion of structural units derived from (meth)acrylic acid alkyl ester compounds in the polymer block (A) is, for example, 99% by mass or less, preferably 98% by mass or less, and more preferably 95% by mass or less, from the viewpoint of fully obtaining the improving effect due to the introduction of crosslinkable functional groups.

[0068] In the polymer block (A), the proportion of structural units derived from a crosslinkable group-containing vinyl monomer (i.e., crosslinkable group-containing vinyl units) is preferably 1% by mass or more relative to all structural units constituting the polymer block (A). Setting the proportion of crosslinkable group-containing vinyl units to 1% by mass or more is advantageous in that sufficient improvement in mechanical strength can be achieved. The proportion of crosslinkable group-containing vinyl units in the polymer block (A) is preferably 2% by mass or more, more preferably 5% by mass or more. On the other hand, from the viewpoint of ensuring flexibility of the vinyl polymer, the upper limit of the crosslinkable group-containing vinyl units is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less, relative to all structural units constituting the polymer block (A).

[0069] The number average molecular weight (Mn) of the polymer block (A) measured by GPC in terms of polystyrene is preferably in the range of 1,000 to 80,000. An Mn of 1,000 or more is preferable because, when a cured product is produced using the block copolymer, the strength and durability of the cured product can be sufficiently increased. On the other hand, an Mn of 80,000 or less is preferable because good fluidity and coatability can be ensured.

[0070] From the viewpoint of the strength of the cured product, the Mn of the polymer block (A) is more preferably 2,000 or more, even more preferably 3,000 or more, still more preferably 3,500 or more, and even more preferably 4,000 or more. From the viewpoint of ensuring the fluidity of the block copolymer, the upper limit of the Mn of the polymer block (A) is more preferably 60,000 or less, even more preferably 40,000 or less, still more preferably 20,000 or less, and even more preferably 10,000 or less. A preferred range of the Mn of the polymer block (A) can be set by appropriately combining the above-mentioned upper and lower limits. The Mn of the polymer block (A) is more preferably 2,000 to 60,000, even more preferably 3,000 to 40,000, still more preferably 3,500 to 20,000, and even more preferably 4,000 to 10,000.

[0071] The polymer block (A) preferably has a weight average molecular weight (Mw) in terms of polystyrene, measured by GPC, in the range of 1,200 to 100,000. An Mw of 1,200 or more is preferable because, when a cured product is produced using the block copolymer, the strength and durability of the cured product can be sufficiently increased. An Mw of 100,000 or less is preferable because good fluidity and coatability can be ensured.

[0072] From the viewpoint of the strength of the cured product, the Mw of the polymer block (A) is more preferably 2,000 or more, even more preferably 3,000 or more, even more preferably 4,000 or more, and even more preferably 5,000 or more. From the viewpoint of ensuring the fluidity of the block copolymer, the upper limit of the Mw of the polymer block (A) is more preferably 80,000 or less, even more preferably 60,000 or less, even more preferably 40,000 or less, and even more preferably 15,000 or less. A preferred range of the Mw of the polymer block (A) can be set by appropriately combining the above-mentioned upper and lower limits. The Mw of the polymer block (A) is more preferably 2,000 to 80,000, even more preferably 3,000 to 60,000, even more preferably 4,000 to 40,000, and even more preferably 5,000 to 15,000.

[0073] When a block copolymer has a plurality of polymer blocks (A), the number average molecular weight of the polymer block (A) represents the sum of the number average molecular weights of all the polymer blocks (A). For example, when the block copolymer is an (A)-(B)-(A) triblock copolymer consisting of polymer block (A) / polymer block (B) / polymer block (A), the "number average molecular weight of the polymer block (A)" refers to the sum of the number average molecular weights of the two polymer blocks (A) contained in the block copolymer. The same applies to the weight average molecular weight and the polymer block (B).

[0074] From the viewpoint of obtaining a cured product excellent in tensile properties (elongation at break, strength at break, etc.) and weather resistance, the molecular weight distribution (Mw / Mn) of the polymer block (A) is preferably 1.80 or less, more preferably 1.75 or less, even more preferably 1.70 or less, and still more preferably 1.50 or less. The lower limit of the molecular weight distribution (Mw / Mn) may be, for example, 1.05 or more, or 1.10 or more.

[0075] Polymer Block (B) Examples of monomers constituting the polymer block (B) include the compounds exemplified as specific examples of monomers constituting a vinyl polymer. Among the above-exemplified monomers, the polymer block (B) is preferably a polymer having a (meth)acrylic acid alkyl ester compound as a main structural unit, more preferably a polymer having a (meth)acrylic acid alkyl ester having an alkyl group with 2 to 18 carbon atoms in the ester moiety as a main structural unit, in that it can give a vinyl polymer with excellent flexibility, and even more preferably a polymer having a (meth)acrylic acid alkyl ester having an alkyl group with 4 to 18 carbon atoms in the ester moiety as a main structural unit.

[0076] In polymer block (B), the proportion of structural units derived from a (meth)acrylic acid alkyl ester compound is preferably 50% by mass or more relative to all structural units constituting polymer block (B), from the viewpoint of obtaining a vinyl polymer having excellent mechanical properties. The proportion of structural units derived from a (meth)acrylic acid alkyl ester compound in polymer block (B) is more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more.

[0077] When the fluidity of the block copolymer is taken into consideration, the polymer block (B) preferably has a structural unit derived from an alkyl acrylate ester having an alkyl group of 4 to 8 carbon atoms in the ester moiety. Furthermore, when considering improving compatibility with other polymers (e.g., polyoxyalkylene polymers) to be blended in the curable resin composition when preparing a curable resin composition containing the block copolymer, the polymer block (B) preferably has a structural unit derived from an alkyl (meth)acrylate ester having an alkyl group of 10 or more carbon atoms in the ester moiety, and more preferably has a structural unit derived from an alkyl (meth)acrylate ester having an alkyl group of 10 to 18 carbon atoms in the ester moiety.

[0078] In polymer block (B), the proportion of structural units derived from a (meth)acrylic acid alkyl ester having an alkyl group having 4 to 8 carbon atoms in the ester moiety is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and still more preferably 70% by mass or more, based on all structural units constituting polymer block (B), from the viewpoint of obtaining a block copolymer that exhibits sufficient fluidity and is excellent in mechanical properties.

[0079] From the viewpoint of improving compatibility with other polymers, the proportion of structural units derived from a (meth)acrylic acid alkyl ester having an alkyl group having 10 or more carbon atoms (preferably 10 to 18 carbon atoms) in the ester moiety is preferably 1% by mass or more, and more preferably 5% by mass or more, based on all structural units constituting polymer block (B). The upper limit is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less, and even more preferably 30% by mass or less, based on all structural units constituting polymer block (B).

[0080] The polymer block (B) may further have a crosslinkable functional group. When the polymer block (B) has a crosslinkable functional group, examples of the crosslinkable functional group include the groups exemplified as the crosslinkable functional groups possessed by vinyl polymers. From the viewpoint of forming a uniform crosslinked structure, it is preferable to concentrate crosslinking points in the polymer block (A). From this viewpoint, it is preferable that the ratio of structural units derived from the crosslinkable group-containing vinyl monomer to all structural units constituting the polymer block (B) is lower than the ratio of structural units derived from the crosslinkable group-containing vinyl monomer to all structural units constituting the polymer block (A).

[0081] Specifically, the proportion of structural units derived from crosslinkable group-containing vinyl monomers (i.e., crosslinkable group-containing vinyl units) in polymer block (B) is preferably 15% by mass or less relative to all structural units constituting polymer block (B). A proportion of crosslinkable group-containing vinyl units in polymer block (B) of 15% by mass or less is preferable in that sufficient flexibility of the block copolymer can be ensured. The proportion of crosslinkable group-containing vinyl units in polymer block (B) is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 2% by mass or less, and even more preferably 1% by mass or less relative to all structural units constituting polymer block (B).

[0082] The number average molecular weight (Mn) of the polymer block (B) measured by GPC in terms of polystyrene is preferably in the range of 9,000 to 250,000. When Mn is 9,000 or more, when a cured product is produced using the block copolymer, the strength and durability of the cured product can be sufficiently high. Furthermore, when Mn is 250,000 or less, good fluidity and coatability can be ensured. Furthermore, when Mn of the polymer block (B) is in the above range, the molecular weight of the molecular chain portion corresponding to the distance between crosslink points can be sufficiently ensured.

[0083] From the viewpoint of the strength of the cured product, etc., the Mn of the polymer block (B) is more preferably 14,000 or more, even more preferably 19,000 or more, still more preferably 23,000 or more, and even more preferably 25,000 or more. From the viewpoint of ensuring the fluidity of the polymer, etc., the upper limit of the Mn of the polymer block (B) is more preferably 150,000 or less, even more preferably 100,000 or less. A preferred range of the Mn of the polymer block (B) can be set by appropriately combining the above-mentioned upper and lower limits. The Mn of the polymer block (B) is more preferably 14,000 to 150,000, even more preferably 19,000 to 100,000, and even more preferably 23,000 to 80,000.

[0084] The polymer block (B) preferably has a weight average molecular weight (Mw) in terms of polystyrene, measured by GPC, in the range of 10,000 to 300,000. When the block copolymer is used to produce a cured product, the strength and durability of the cured product can be sufficiently high. When the block copolymer is used to produce a cured product, the Mw of the block copolymer is 300,000 or less. This ensures good flowability and coatability, and also ensures a sufficient molecular weight of the molecular chain portion corresponding to the distance between crosslinking points.

[0085] From the viewpoint of the strength of the cured product, the Mw of the polymer block (B) is more preferably 15,000 or more, even more preferably 20,000 or more, still more preferably 25,000 or more, and even more preferably 30,000 or more. From the viewpoint of ensuring the flowability of the polymer, the upper limit of the Mw of the polymer block (B) is more preferably 250,000 or less, even more preferably 200,000 or less. A preferred range of the Mw of the polymer block (B) can be set by appropriately combining the above-mentioned upper and lower limits. The Mw of the polymer block (B) is more preferably 15,000 to 250,000, even more preferably 20,000 to 200,000, and even more preferably 30,000 to 200,000.

[0086] The molecular weight distribution (Mw / Mn) of the polymer block (B) is preferably 3.0 or less from the viewpoint of obtaining a polymer having excellent weather resistance. The molecular weight distribution of the polymer block (B) is more preferably 2.5 or less, even more preferably 2.2 or less, and still more preferably 2.0 or less. The lower limit of the molecular weight distribution of the polymer block (B) is not particularly limited, but from the viewpoint of ease of production, it is, for example, 1.05 or more.

[0087] Block Copolymer Structure Examples of block copolymer structures having polymer block (A) and polymer block (B) include an (A)-(B) diblock consisting of polymer block (A) and polymer block (B), an (A)-(B)-(A) triblock consisting of polymer block (A) / polymer block (B) / polymer block (A), a (B)-(A)-(B) triblock consisting of polymer block (B) / polymer block (A) / polymer block (B), and an (A)-(B)-(A)-(B)-(A) pentablock consisting of polymer block (A) / polymer block (B) / polymer block (A) / polymer block (B) / polymer block (A). The block copolymer may further include a polymer block (C) other than polymer block (A) and polymer block (B). Examples of the monomer constituting polymer block (C) include the compounds exemplified as specific examples of the monomer constituting the present polymer.

[0088] Among these, the block copolymer is preferably a triblock copolymer, and more preferably an (A)-(B)-(A) triblock copolymer, because by using as few blocks as possible, it is possible to obtain a polymer that exhibits excellent weather resistance while ensuring ease of production. With such a structure, the polymer block (A) having a structural unit derived from a crosslinkable group-containing vinyl monomer acts as a crosslinked segment, thereby easily forming a uniform crosslinked structure while ensuring the molecular weight between crosslinking points, and is advantageous in that the mechanical strength and weather resistance of the resulting cured product can be increased.

[0089] In the block copolymer, the proportions of polymer block (A) and polymer block (B) are not particularly limited, but from the viewpoint of sufficiently introducing crosslinking points into the block copolymer to obtain a polymer with high mechanical strength and weather resistance, the proportion of polymer block (A) is preferably 2 parts by mass or more per 100 parts by mass of the total amount of polymer block (A) and polymer block (B). The proportion of polymer block (A) is more preferably 4 parts by mass or more, even more preferably 6 parts by mass or more, even more preferably 8 parts by mass or more, and even more preferably 10 parts by mass or more per 100 parts by mass of the total amount of polymer block (A) and polymer block (B). The upper limit of the content of polymer block (A) is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, even more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less per 100 parts by mass of the total amount of polymer block (A) and polymer block (B).

[0090] <Production of Block Copolymers> The polymerization method for obtaining a block copolymer is not particularly limited as long as it contains two or more polymer blocks. For example, various controlled polymerization methods such as living radical polymerization and living anionic polymerization can be used to obtain a block copolymer with precisely controlled molecular weight and molecular weight distribution. Alternatively, a block copolymer may be produced by coupling polymers having functional groups. Among these, production by living radical polymerization is preferred because it is easy to operate, can be applied to a wide range of monomers, and can reduce the content of metal components that may affect durability at high temperatures, thereby producing a cured product with excellent heat resistance.

[0091] When producing a vinyl polymer by living radical polymerization, known polymerization methods can be used as the living radical polymerization method. Specific examples of living radical polymerization methods include exchange chain transfer mechanism-type living radical polymerization methods, bond-dissociation mechanism-type living radical polymerization methods, and atom transfer mechanism-type living radical polymerization methods. Of these, exchange chain transfer mechanism-type living radical polymerization methods are preferred because they can be applied to the widest range of vinyl monomers and have excellent controllability over polymerization. From the viewpoint of ease of implementation, reversible addition-fragmentation chain transfer polymerization (RAFT) methods are particularly preferred.

[0092] In the RAFT method, polymerization proceeds via a reversible chain transfer reaction in the presence of a living radical polymerization control agent (RAFT agent) and a polymerization initiator. As the RAFT agent, various known RAFT agents such as dithioester compounds, xanthate compounds, trithiocarbonate compounds, and dithiocarbamate compounds can be used. Among these, dithioester compounds or trithiocarbonate compounds are preferably used, and trithiocarbonate compounds are more preferably used, due to their excellent polymerization controllability of (meth)acrylic acid ester compounds. Examples of compounds having a trithiocarbonate group include S,S-dibenzyltrithiocarbonate, bis[4-(2,3-dihydroxypropoxycarbonyl)benzyl]trithiocarbonate, bis[4-(2-hydroxyethoxycarbonyl)benzyl]trithiocarbonate, and 1,4-bis(alkylsulfanylthiocarbonylsulfanylmethyl)benzene (for example, 1,4-bis(n-dodecylsulfanylthiocarbonylsulfanylmethyl)benzene).

[0093] The RAFT agent may be a monofunctional agent having only one active site per molecule, or a polyfunctional agent having two or more active sites per molecule. Polymerization is preferably carried out using a bifunctional RAFT agent, since this allows for efficient production of an (A)-(B)-(A) triblock block copolymer consisting of polymer block (A) / polymer block (B) / polymer block (A). The amount of the RAFT agent used can be adjusted appropriately depending on the type of monomer and RAFT agent used, etc.

[0094] For example, when an (A)-(B)-(A) triblock polymer consisting of polymer block (A) / polymer block (B) / polymer block (A) is obtained by living radical polymerization using a bifunctional RAFT agent (e.g., S,S-dibenzyltrithiocarbonate), the target product can be efficiently obtained by a method including the following two-stage polymerization process for polymerizing a vinyl-based monomer. That is, in the first step (first polymerization step), a vinyl-based monomer is polymerized in the presence of a RAFT agent and a polymerization initiator to obtain polymer block (A). Next, in the second step (second polymerization step), a vinyl-based monomer is polymerized in the presence of the polymer block (A) obtained in the first polymerization step and a polymerization initiator to form polymer block (B). This allows an (A)-(B)-(A) triblock polymer consisting of polymer block (A) / polymer block (B) / polymer block (A) to be obtained. Furthermore, by a similar method, it is also possible to obtain a block copolymer having a higher order than a triblock copolymer (for example, an (A)-(B)-(A)-(B)-(A) pentablock copolymer).

[0095] As the polymerization initiator, known radical polymerization initiators such as azo compounds, organic peroxides, and persulfates can be used. Among these, azo compounds are preferred because they are easy to handle safely and are less likely to cause side reactions during radical polymerization. Specific examples of azo compounds include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], and 2,2'-azobis(N-butyl-2-methylpropionamide). Only one polymerization initiator may be used, or two or more polymerization initiators may be used in combination. Furthermore, the polymerization initiator used in the first polymerization step and the polymerization initiator used in the second polymerization step may be the same or different.

[0096] The amount of polymerization initiator used is not particularly limited and can be set appropriately depending on the polymerization method used. For example, in the case of the RAFT method, from the viewpoint of obtaining a polymer with a narrower molecular weight distribution, the amount of polymerization initiator used per 1 mol of RAFT agent is preferably 0.5 mol or less, and more preferably 0.4 mol or less. Furthermore, from the viewpoint of stably carrying out the polymerization reaction, the lower limit of the amount of polymerization initiator used per 1 mol of RAFT agent is preferably 0.01 mol or more, and more preferably 0.05 mol or more. The amount of polymerization initiator used per 1 mol of RAFT agent is preferably 0.01 to 0.5 mol, and more preferably 0.05 to 0.4 mol.

[0097] In the case of the RAFT method, the polymerization reaction may be carried out, if necessary, in the presence of a chain transfer agent such as an alkylthiol compound having 2 to 20 carbon atoms. Furthermore, if necessary, a dehydrating agent such as trimethyl orthoacetate or triethyl orthoacetate may be mixed into the reaction system.

[0098] The polymerization method of living radical polymerization is not particularly limited, and various methods such as solution polymerization, emulsion polymerization, miniemulsion polymerization, suspension polymerization, and bulk polymerization can be appropriately employed. For example, when using a solution polymerization method, the polymerization reaction is carried out using a known polymerization solvent. Various solvents can be used as the polymerization solvent, and examples thereof include saturated hydrocarbon compounds, aromatic compounds, ester compounds, ketone compounds, alcohol compounds, ether compounds, nitrile compounds, and water. As the polymerization solvent, it is preferable to use a solvent capable of dissolving the monomer, and it is more preferable to use an organic solvent capable of dissolving the monomer. Note that one type of polymerization solvent may be used alone, or two or more types may be used in combination.

[0099] Specific examples of polymerization solvents include saturated hydrocarbon compounds such as hexane, heptane, and cyclohexane; aromatic compounds such as benzene, toluene, xylene, and anisole; ester compounds such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl formate, and methyl propionate; ketone compounds such as acetone, methyl ethyl ketone, and cyclohexanone; alcohol compounds such as methanol, ethanol, and 2-propanol; ether compounds such as tetrahydrofuran; and nitrile compounds such as acetonitrile. Other polymerization solvents that may be used include dimethylformamide, dimethyl sulfoxide, and water. It is preferable to use a solvent capable of dissolving the monomer as the polymerization solvent. One polymerization solvent may be used alone, or two or more polymerization solvents may be used in combination.

[0100] The amount of the polymerization solvent used is preferably 5 to 200 parts by mass, more preferably 10 to 100 parts by mass, per 100 parts by mass of the total amount of the monomers used in the polymerization reaction. Using 100 parts by mass or less of the polymerization solvent is preferred because a high polymerization rate can be achieved in a short period of time. Using 10 parts by mass or more of the polymerization solvent is also preferred because the heat of polymerization can be efficiently removed and an increase in the reaction temperature can be suppressed.

[0101] The method for feeding the raw materials may be a batch-type initial lump-sum feeding in which all the raw materials are fed at once, a semi-continuous feeding in which at least some of the raw materials are continuously fed into the reactor, or a continuous polymerization method in which all the raw materials are continuously fed and at the same time the product is continuously withdrawn from the reactor.

[0102] In terms of easily obtaining the vinyl polymer of the present disclosure, it is preferable to carry out the polymerization step of polymerizing the vinyl monomer while continuously or intermittently supplying at least a portion of the total amount of the crosslinkable group-containing vinyl monomer into the reactor. This method is thought to be able to suppress the variation in the number of crosslinkable functional groups per polymer molecule, and to introduce a uniform number of crosslinkable functional groups into each polymer. That is, it is thought to be able to reduce the proportion of molecules having more crosslinkable functional groups than the average number of crosslinkable functional groups introduced, molecules having fewer crosslinkable functional groups than the average number, and molecules having no crosslinkable functional groups, relative to the average number of crosslinkable functional groups per polymer molecule. This suppresses the variation in the crosslinked structure when the vinyl polymer is crosslinked, and as a result, a cured product having excellent weather resistance and heat resistance can be obtained.

[0103] When obtaining an (A)-(B)-(A) triblock polymer consisting of polymer block (A) / polymer block (B) / polymer block (A) as a vinyl polymer, for the reasons described above, the triblock polymer is preferably produced by a method including the first and second polymerization steps, in which the first polymerization step is carried out while continuously or intermittently supplying at least a portion of the total amount of crosslinkable group-containing vinyl monomer used to produce polymer block (A) into a reactor. In this case, crosslinkable functional groups can be introduced into polymer blocks (A) located at both ends of the vinyl polymer while suppressing variation in the number of intermolecular crosslinkable functional groups. This allows for the production of a cured product exhibiting excellent weather resistance and heat resistance.

[0104] When the crosslinkable group-containing vinyl monomer is continuously or intermittently supplied to the reactor during the production of polymer block (A), all of the crosslinkable group-containing vinyl monomer used to produce polymer block (A) may be continuously or intermittently supplied to the reactor after the initiation of polymerization (i.e., after the addition of the polymerization initiator). Alternatively, a portion of the crosslinkable group-containing vinyl monomer used to produce polymer block (A) may be charged to the reactor before the initiation of polymerization (i.e., before the addition of the polymerization initiator), and the remaining crosslinkable group-containing vinyl monomer may be continuously or intermittently supplied to the reactor after the initiation of polymerization. From the viewpoint of highly uniformity in the number of crosslinkable functional groups per polymer molecule, it is preferred to charge a portion of the crosslinkable group-containing vinyl monomer used to produce polymer block (A) to the reactor before the initiation of polymerization and to continuously or intermittently supply the remaining portion to the reactor after the initiation of polymerization. In the following, among the vinyl monomers used in the production of polymer block (A), a monomer charged into a reactor before the start of polymerization is also referred to as an "initially charged monomer", and a monomer continuously or intermittently supplied into a reactor after the start of polymerization is also referred to as a "continuously supplied monomer".

[0105] With respect to the ratio of the crosslinkable group-containing vinyl monomer used in the production of polymer block (A), the ratio of the continuously supplied monomer is preferably 10 to 100% by mass of the total amount of the crosslinkable group-containing vinyl monomer used in the production of polymer block (A). From the viewpoint of ensuring a uniform number of crosslinkable group-containing vinyl monomers introduced into each molecule of polymer block (A), the ratio of the continuously supplied monomer to the total amount of the crosslinkable group-containing vinyl monomer used in the production of polymer block (A) is more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, even more preferably 50% by mass or more, and even more preferably 60% by mass or more. Furthermore, the ratio of the continuously supplied monomer to the total amount of the crosslinkable group-containing vinyl monomer used in the production of polymer block (A) is more preferably 95% by mass or less, even more preferably 90% by mass or less.

[0106] The supply mode of the continuously supplied monomer is not particularly limited as long as the crosslinkable group-containing vinyl monomer can be supplied into the reactor over a predetermined time period after the initiation of polymerization. For example, the crosslinkable group-containing vinyl monomer may be supplied into the reactor continuously (i.e., without interruption) or intermittently (i.e., intermittently). In order to more uniformly introduce the crosslinkable group-containing vinyl monomer into each molecule of the polymer block (A), the supply mode of the crosslinkable group-containing vinyl monomer after the initiation of polymerization is preferably continuous supply.

[0107] The timing for starting the continuous or intermittent supply of the crosslinkable group-containing vinyl monomer may be simultaneous with the initiation of polymerization, or may be after a predetermined time has elapsed since the initiation of polymerization. From the viewpoint of introducing the crosslinkable group-containing vinyl unit into the end of the vinyl polymer and thereby obtaining a cured product excellent in weather resistance and heat resistance, the continuous or intermittent supply of the crosslinkable group-containing vinyl monomer may be started simultaneously with or immediately after the initiation of polymerization. When the crosslinkable group-containing vinyl monomer is supplied into the reactor after the initiation of polymerization, the crosslinkable group-containing vinyl monomer is supplied over, for example, 10 minutes to 8 hours, and preferably over 30 minutes to 6 hours.

[0108] The reaction temperature and reaction time in the polymerization reaction can be appropriately set depending on the type of polymerization method used, the types of monomers and polymerization solvents used, etc. For example, in the case of the RAFT method, the reaction temperature is preferably 40°C or higher and 100°C or lower, more preferably 45°C or higher and 90°C or lower, and even more preferably 50°C or higher and 80°C or lower. A reaction temperature of 40°C or higher is preferred because the polymerization reaction can proceed smoothly, and a reaction temperature of 100°C or lower is preferred because side reactions can be suppressed and restrictions on the initiators and polymerization solvents that can be used are relaxed. The reaction time is, for example, 1 hour or higher and 48 hours or lower, and preferably 2 hours or higher and 24 hours or lower.

[0109] By the above polymerization, a solution containing a vinyl polymer is obtained as a polymer-containing solution. The polymer-containing solution obtained by polymerization may be subjected to a known solvent removal treatment, thereby isolating and / or purifying the vinyl polymer. Furthermore, if necessary, the following reaction steps may be carried out, and then the obtained polymer may be isolated and / or purified. The treatment for isolating and purifying the polymer may be carried out according to a known method.

[0110] When the vinyl polymer obtained by the polymerization has a thiocarbonylthio group derived from a RAFT agent, a step of reacting the vinyl polymer with a nucleophilic agent (hereinafter also referred to as a "post-treatment step") may be carried out. By reacting the nucleophilic agent with the thiocarbonylthio group of the vinyl polymer, the thiocarbonylthio group is converted to a thiol group, and the thiol group reacts with unreacted monomers remaining in the polymerization system (for example, acrylate compounds in the reaction system) (Michael addition reaction), thereby obtaining a vinyl polymer from which the thiocarbonylthio group has been removed.

[0111] Examples of the nucleophilic agent include ammonia, primary and / or secondary amine compounds, alkali metal alkoxides, hydroxides, thiols, etc. Among these, from the viewpoint of reactivity, primary and / or secondary amine compounds are preferably used as the nucleophilic agent.

[0112] The amount of the nucleophile used is preferably an amount such that the molar equivalent of the nucleophile relative to the thiocarbonylthio group is 2 to 90 mol equivalents. From the viewpoint of reaction efficiency, the amount of the nucleophile used is preferably 2.5 mol equivalents or more relative to the thiocarbonylthio group, more preferably 3 mol equivalents or more, and even more preferably 3.5 mol equivalents or more. Furthermore, from the viewpoint of reducing the influence of odor due to unreacted nucleophile, the amount of the nucleophile used is preferably 75 mol equivalents or less relative to the thiocarbonylthio group, more preferably 60 mol equivalents or less, and even more preferably 50 mol equivalents or less.

[0113] As the reactor used in the reaction of the thiocarbonylthio group with the nucleophilic agent, known reactors such as a batch reactor and a tubular reactor can be used. The reaction temperature is preferably 10°C or higher, more preferably 15°C or higher, and even more preferably 25°C or higher, in order to increase the reaction efficiency. Furthermore, in order to prevent side reactions (e.g., nucleophilic reactions to the polymer main chain, etc.), the reaction temperature is preferably 80°C or lower, more preferably 60°C or lower, and even more preferably 50°C or lower. The reaction pressure is usually normal pressure, but may be increased or reduced as necessary. From the viewpoint of reaction efficiency, the reaction time is preferably 1 hour or longer, more preferably 2 hours or longer. Furthermore, the upper limit of the reaction time is preferably 48 hours or shorter, more preferably 24 hours or shorter, in order to suppress side reactions such as nucleophilic reactions to the polymer main chain. When a polymer solution is obtained by the above reaction, the polymer can be isolated by subjecting the polymer solution to a known solvent removal treatment.

[0114] <<Curable Resin Composition>> The vinyl polymer of the present disclosure has high weather resistance and is therefore suitable for applications such as sealants, adhesives, pressure-sensitive adhesives, and coating materials. The vinyl polymer of the present disclosure can be used alone for applications such as sealants, adhesives, pressure-sensitive adhesives, and coating materials, but may also be used as a curable resin composition containing various components such as known additives, as needed. For example, a curable resin composition can be obtained by blending a necessary crosslinking agent, a curing accelerator (also referred to as a curing catalyst), another polymer having a crosslinkable functional group, etc., depending on the type of crosslinkable functional group possessed by the vinyl polymer. In addition, a cured product suitable for the application can be obtained by molding the curable resin composition and, as needed, subjecting it to heat treatment or the like.

[0115] Other polymers having crosslinkable functional groups Examples of other polymers having crosslinkable functional groups include hydrocarbon polymers such as polyoxyalkylene polymers having crosslinkable functional groups, polyester polymers having crosslinkable functional groups, polyurethane polymers having crosslinkable functional groups, polybutadiene polymers having crosslinkable functional groups, hydrogenated polybutadiene polymers having crosslinkable functional groups, and polyisobutylene polymers having crosslinkable functional groups; polyamide polymers; bisphenol polymers, etc. Among these, in terms of excellent mechanical properties of the cured product, it is preferable that the curable resin composition of the present disclosure contains a polyoxyalkylene polymer having a crosslinkable functional group together with the vinyl polymer of the present disclosure. Examples of the crosslinkable functional groups possessed by the other polymers include the groups exemplified as the crosslinkable functional groups that the vinyl polymer of the present disclosure may have.

[0116] The polyoxyalkylene polymer having a crosslinkable functional group (hereinafter also referred to as a "crosslinkable polyoxyalkylene polymer") may be a polymer having a repeating unit represented by the following formula (2): ４ -...(2) (In formula (2), R ４ represents a divalent hydrocarbon group.

[0117] R in the above formula (2) ４ Examples of the structure include the following: -(CH ２ ) ｍ - (m is an integer from 1 to 10) -CH(CH ３ ) CH ２ - -CH(C ２ H ５ ) CH ２ - -C(CH ３ ) ２ CH ２ The crosslinkable polyoxyalkylene polymer may contain one or a combination of two or more of the above repeating units. Among these, —CH(CH ３ ) CH ２ - is preferred.

[0118] As the crosslinkable functional group possessed by the crosslinkable polyoxyalkylene polymer, a crosslinkable silyl group is preferred in terms of excellent compatibility with the vinyl polymer of the present disclosure, excellent mechanical properties of the cured product, and excellent weather resistance, and an alkoxysilyl group is more preferred in terms of ease of control of reactivity.

[0119] The method for producing a crosslinkable polyoxyalkylene polymer is not particularly limited, and examples thereof include a polymerization method using a corresponding epoxy compound or diol compound as a raw material, with an alkali catalyst (e.g., KOH), a polymerization method with a transition metal compound-porphyrin complex catalyst, a polymerization method with a composite metal cyanide complex catalyst, and a polymerization method using phosphazene.

[0120] The average number of crosslinkable silyl groups contained in one molecule of the crosslinkable polyoxyalkylene polymer is preferably in the range of 1 to 4, more preferably in the range of 1.5 to 3, from the viewpoint of the mechanical properties and adhesiveness of the cured product. The position of the crosslinkable silyl group contained in the crosslinkable polyoxyalkylene polymer is not particularly limited, and the crosslinkable silyl group can be located in a side chain and / or at the end of the polymer. The crosslinkable polyoxyalkylene polymer to be blended in the curable resin composition may be either a linear polymer or a branched polymer. These may also be used in combination.

[0121] The number average molecular weight (Mn) of the crosslinkable polyoxyalkylene polymer, measured by GPC in terms of polystyrene, is preferably 5,000 or more, more preferably 10,000 or more, and even more preferably 15,000 or more, from the viewpoint of mechanical properties. The upper limit of Mn is preferably 60,000 or less, more preferably 50,000 or less, and even more preferably 40,000 or less, from the viewpoint of achieving low viscosity and improving workability when applying the curable resin composition. The range of Mn is preferably 5,000 to 60,000, more preferably 10,000 to 60,000, and even more preferably 15,000 to 50,000.

[0122] Commercially available crosslinkable polyoxyalkylene polymers may be used. Specific examples include "MS Polymer S203," "MS Polymer S303," "MS Polymer S810," "Silyl SAX510," "Silyl SAX220," "Silyl SAT200," "Silyl SAT350," "Silyl EST280," and "Silyl SAT30," all manufactured by Kaneka Corporation, and "Excestar ES-S2410," "Excestar ES-S2420," "Excestar ES-S3430," and "Excestar ES-S4530" (all trade names) manufactured by AGC.

[0123] When the curable resin composition contains a crosslinkable polyoxyalkylene polymer, the content thereof is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, relative to 100 parts by mass of the total amount of the vinyl polymer and the crosslinkable polyoxyalkylene polymer of the present disclosure. By setting the content of the crosslinkable polyoxyalkylene polymer within the above range, a cured product with excellent mechanical properties can be obtained. Furthermore, from the viewpoint of obtaining a cured product exhibiting excellent weather resistance, the upper limit of the content of the crosslinkable polyoxyalkylene polymer is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 85 parts by mass or less, relative to 100 parts by mass of the total amount of the vinyl polymer and the crosslinkable polyoxyalkylene polymer of the present disclosure.

[0124] The mass ratio of the vinyl polymer to the crosslinkable oxyalkylene polymer of the present disclosure, expressed as vinyl polymer / oxyalkylene polymer, is preferably 5 / 95 to 95 / 5, more preferably 10 / 90 to 90 / 10, and even more preferably 15 / 85 to 85 / 15.

[0125] Crosslinking Agent (Curing Agent) Examples of the crosslinking agent (curing agent) include an epoxy compound having two or more epoxy groups, an isocyanate compound having two or more isocyanate groups, an aziridine compound having two or more aziridinyl groups, an oxazoline compound having an oxazoline group, a metal chelate compound, a butylated melamine compound, etc. When a crosslinking agent is added, among these, epoxy compounds, isocyanate compounds, and aziridine compounds are preferred, and among these, isocyanate compounds are preferred in that they can give a cured product with good physical properties under high temperature conditions.

[0126] When the curable resin composition contains a crosslinking agent, the content thereof is usually 0.01 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the total of the vinyl polymer and the polyoxyalkylene polymer of the present disclosure. The content of the crosslinking agent is preferably 0.03 to 5 parts by mass, more preferably 0.05 to 2 parts by mass.

[0127] Curing Accelerator (Curing Catalyst) Known compounds such as tin-based catalysts, titanium-based catalysts, and tertiary amines can be used as the curing accelerator (curing catalyst). Examples of tin-based catalysts include dibutyltin dilaurate, dibutyltin diacetate, dibutyltin diacetonate, and dioctyltin dilaurate. Specific examples include products manufactured by Nitto Kasei Co., Ltd., such as "Neostan U-28," "Neostan U-100," "Neostan U-200," "Neostan U-220H," "Neostan U-303," and "SCAT-24." Examples of titanium-based catalysts include tetraisopropyl titanate, tetra-n-butyl titanate, titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethyl acetylacetonate, dibutoxytitanium diacetylacetonate, diisopropoxytitanium diacetylacetonate, titanium octylene glycolate, and titanium lactate. Examples of tertiary amines include triethylamine, tributylamine, triethylenediamine, hexamethylenetetramine, 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), diazabicyclononene (DBN), N-methylmorpholine, and N-ethylmorpholine.

[0128] The amount of the curing accelerator to be added is preferably 0.1 to 5 parts by mass, and more preferably 0.5 to 2 parts by mass, per 100 parts by mass of the total amount of the vinyl polymer and polyoxyalkylene polymer of the present disclosure.

[0129] In addition to the above, other components that can be added to the curable resin composition include, for example, a plasticizer, a filler, a pigment, an adhesion promoter, a dehydrating agent, an antioxidant, an ultraviolet absorber, a crosslinking agent (also called a curing agent), and an oil.

[0130] Examples of plasticizers include liquid polyurethane resins, polyester-based plasticizers obtained from dicarboxylic acids and diols; etherified or esterified products of polyalkylene glycols such as polyethylene glycol and polypropylene glycol; polyether-based plasticizers such as sugar-based polyethers obtained by addition polymerization of alkylene oxides such as ethylene oxide and propylene oxide to a sugar polyhydric alcohol such as sucrose, followed by etherification or esterification; polystyrene-based plasticizers such as poly-α-methylstyrene; and poly(meth)acrylates without crosslinkable functional groups. Of these, poly(meth)acrylates without crosslinkable functional groups are preferred in terms of durability, such as weather resistance, of the cured product. Among these, polymers with a Mw of 1,000 to 7,000 and a glass transition temperature of −30° C. or lower are preferred.

[0131] The amount of the plasticizer used is preferably in the range of 0 to 100 parts by mass, or alternatively in the range of 0 to 90 parts by mass, or alternatively in the range of 10 to 90 parts by mass, relative to 100 parts by mass of the total amount of the vinyl polymer and the polyoxyalkylene polymer of the present disclosure.

[0132] Examples of fillers include light calcium carbonate having an average particle size of about 0.02 to 2.0 μm, heavy calcium carbonate having an average particle size of about 1.0 to 5.0 μm, titanium oxide, carbon black, synthetic silicic acid, talc, zeolite, mica, silica, calcined clay, kaolin, bentonite, aluminum hydroxide, barium sulfate, glass balloons, silica balloons, and polymethyl methacrylate balloons. These fillers can improve the mechanical properties of the cured product, and can increase the tensile strength and tensile elongation.

[0133] Among these, preferred fillers are light calcium carbonate, heavy calcium carbonate, and titanium oxide, which are effective in improving physical properties, and a mixture of light calcium carbonate and heavy calcium carbonate is more preferred. The amount of filler blended is preferably 20 to 300 parts by mass, more preferably 50 to 200 parts by mass, per 100 parts by mass of the total amount of the vinyl polymer and polyoxyalkylene polymer of the present disclosure. When a mixture of light calcium carbonate and heavy calcium carbonate is used, the ratio of light calcium carbonate to heavy calcium carbonate is preferably in the range of 90 / 10 to 50 / 50 by mass. Titanium oxide, carbon black, or the like may be blended as a pigment in the curable resin composition.

[0134] Examples of adhesion promoters include aminosilanes such as those sold under the trade names "KBM602," "KBM603," "KBE602," "KBE603," "KBM902," and "KBM903" by Shin-Etsu Silicones Co., Ltd., and those sold under the trade name "SH6020" by Dow Corning Toray Co., Ltd. Examples of dehydrating agents include methyl orthoformate, methyl orthoacetate, and vinylsilane.

[0135] Examples of the antiaging agent that can be used include ultraviolet absorbers such as benzophenone compounds, benzotriazole compounds, and oxalic acid anilide compounds, light stabilizers such as hindered amine compounds, antioxidants such as hindered phenols, heat stabilizers, and mixtures thereof.

[0136] Examples of ultraviolet absorbers include those manufactured by BASF under the trade names "Tinuvin 571," "Tinuvin 1130," and "Tinuvin 327." Examples of light stabilizers include those manufactured by BASF under the trade names "Tinuvin 292," "Tinuvin 144," and "Tinuvin 123," and those manufactured by Sankyo Co., Ltd. under the trade name "Sanol 770." Examples of heat stabilizers include those manufactured by BASF under the trade names "Irganox 1135," "Irganox 1520," and "Irganox 1330." In addition, a product manufactured by BASF under the trade name "Tinuvin B75," which is a mixture of ultraviolet absorber, light stabilizer, and heat stabilizer, may also be used.

[0137] For the purpose of adjusting the performance, coatability, processability, etc. of the curable resin composition containing the vinyl polymer of the present disclosure, other thermoplastic resins may be blended into the curable resin composition. Specific examples of thermoplastic resins include polyolefin resins such as polyethylene and polypropylene, styrene resins such as polystyrene, vinyl resins such as polyvinyl chloride, polyester resins, polyamide resins, etc. Also, known elastomers may be blended.

[0138] The curable resin composition of the present disclosure can be prepared as a one-component curable resin composition in which all ingredients are blended in advance and stored in a sealed container, and the composition cures by absorbing moisture in the air after application. Alternatively, the composition can be prepared as a two-component curable resin composition in which ingredients such as a curing catalyst, filler, plasticizer, and water are blended separately as a curing agent, and the curing agent and the resin composition are mixed before use. Of these, the one-component type is more preferred in terms of ease of handling and the ability to prevent errors in blending during application.

[0139] The curable resin composition containing the vinyl polymer of the present disclosure exhibits good fluidity when heated from room temperature (25° C.) to about 150° C. Therefore, it can be applied to various coating processes as well as molding processes using various methods such as extrusion molding, injection molding, and slip casting.

[0140] The present disclosure will be specifically described below based on examples, but the present disclosure is not limited to these examples. In the following, "parts" and "%" mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Details of the analysis methods for the polymers obtained in the Synthesis Examples, Comparative Synthesis Examples, Production Examples, and Comparative Production Examples are as follows.

[0141] <<Method for Analyzing Vinyl Polymers>> <Molecular Weight Measurement> Using a gel permeation chromatograph (model "HLC-8320", manufactured by Tosoh Corporation), the weight average molecular weight (Mw) and number average molecular weight (Mn) calculated in terms of polystyrene were obtained under the following conditions. The molecular weight distribution (Mw / Mn) was calculated from the obtained values. Measurement conditions Column: TSKgel SuperMultiporeHZ-M x 4, manufactured by Tosoh Corporation Column temperature: 40°C Eluent: Tetrahydrofuran Detector: RI

[0142] <Viscosity Measurement> Using a TVE-20H viscometer (cone / plate type, manufactured by Toki Sangyo Co., Ltd.), E-type viscosity was measured under the following conditions: Measurement conditions: Cone shape: angle 1°34', radius 24 mm (less than 10 Pa·s) angle 3°, radius 7.7 mm (10 Pa·s or more) Temperature: 25°C±0.5°C

[0143] <Gas Chromatography (GC) Measurement> Measurement Conditions Column: Capillary column CP-Wax52CB (60 m × 0.32 mm ID, df = 0.5 μm) manufactured by Agilent Corporation and DB-1 (30 m × 0.32 mm ID, df = 1.0 μm) manufactured by Agilent Corporation Solvent: Tetrahydrofuran Column temperature: 50°C (5 min), 7°C / min, 230°C (5 min)

[0144] <Measurement of Nonvolatile Content of Polymerization Solution> Approximately 0.5 g of a sample was placed in a weighing bottle whose weight had been measured in advance [weight of weighing bottle = B (unit: g)], and the weighing bottle was accurately weighed [weight of sample and weighing bottle before drying = W0 (unit: g)]. The sample was placed in a hot air circulation dryer together with the weighing bottle and dried at 155°C for 45 minutes. The weight of the dried sample together with the weighing bottle was measured [weight of sample and weighing bottle after drying = W1 (unit: g)], and the mass of nonvolatile content in the sample [X (unit: g)] was calculated using the following formula (2): X = (W1 - B) / (W0 - B) (2)

[0145] <Average Number of Crosslinkable Silyl Groups per Vinyl Polymer Molecule> The average number of crosslinkable silyl groups (alkoxysilyl groups) (hereinafter also referred to as "f(Si)") was calculated using the following formula from the amount (parts by mass) of the monomer having a crosslinkable silyl group, assuming that the total amount of the monomers used in the synthesis of the vinyl polymer was 100 parts by mass: f(Si) = {amount of crosslinkable silyl group-containing monomer / (molecular weight of crosslinkable silyl group-containing monomer × 100 / Mn)}

[0146] <Restoration Rate> The restoration rate [%] of the cured vinyl polymer was determined by the following procedure. 100 parts of the vinyl polymer, 70 parts of methyl ethyl ketone, and 20 parts of propylene glycol methyl ether acetate were mixed and dissolved at room temperature, and then 1 part of curing catalyst U-220H (dibutyltin diacetylacetonate, Neostan U-220H (manufactured by Nitto Kasei Co., Ltd.)) was added and mixed to prepare a mixed solution. This mixed solution was slowly poured into a box-shaped container made of a 2 mm thick Teflon (registered trademark) sheet so that the dried film would be 2 mm thick. The mixture was then left to stand at 23°C and 50% RH for at least one week to obtain a cured sheet. A tensile test dumbbell (JIS K 6251 Type 2) was prepared from the cured sheet and used as a test specimen. Using a tensile tester (Autograph AGS-J, manufactured by Shimadzu Corporation), the test piece was stretched at a rate of 5 mm / min so that the gauge length (dumbbell No. 2: 20 mm) became 32 mm, and the test piece was held for 24 hours. Next, the test piece removed from the tensile tester was placed on a 2 mm thick Teflon (registered trademark) sheet, and after 1 hour, the gauge length (L ２ The measurement was carried out under an environment of 23°C and 50% RH. The recovery rate was calculated using the following formula when the test piece could be stretched under the above measurement conditions and recovery behavior was observed after removal from the tensile tester. Recovery rate [%] = (L １ -L ２ ) / (L １ -L ０ ) × 100 where L ０ L: Gauge distance before extension [mm] １ : Gauge distance when extended [mm] L ２: Gauge length [mm] 1 hour after removal from the tensile tester. Here, L ０ = 20 [mm], L １ = 32 [mm].

[0147] <Tensile Properties> Using a tensile test dumbbell (JIS K 6251 Type 2) prepared in the same manner as in the measurement of recovery rate as a test specimen, tensile properties were measured using a tensile tester (Autograph AGS-J, manufactured by Shimadzu Corporation). The measurement was carried out under conditions of a temperature of 23°C, 50% RH, and a tension speed of 200 mm / min, and the breaking elongation (El, unit %), breaking strength (Ts, unit MPa), and strength at 50% elongation (M50, unit MPa).

[0148] <<Production and Evaluation of Vinyl Polymers>> <Production of Polymer Block (A)> [Synthesis Example 1] Production of Polymer a-1 A 1 L flask equipped with a stirrer and a thermometer was charged with S,S-dibenzyl trithiocarbonate (hereinafter also referred to as "DBTTC") (6.7 parts), 2,2'-azobis(2,4-dimethylvaleronitrile) (hereinafter also referred to as "V-65") (0.29 parts), n-butyl acrylate (hereinafter also referred to as "BA") (59.0 parts), ethyl acrylate (hereinafter also referred to as "EA") (3.9 parts), n-tetradecyl acrylate (hereinafter also referred to as "TDA") (15.7 parts), methyldimethoxysilylpropyl methacrylate (hereinafter also referred to as "DMS") (5.4 parts), ethyl acetate (85.1 parts) and trimethyl orthoacetate (hereinafter also referred to as "MOA") (21.3 parts), and the mixture was thoroughly degassed by nitrogen bubbling and heated to 58 ° C. to initiate polymerization. After the start of polymerization, DMS (16.1 parts) was continuously added dropwise to the 1 L flask over 2 hours starting immediately after the start of polymerization. Two hours after the start of polymerization, the temperature was raised to 70°C over 1 hour, and the reaction was continued at 70°C for a further 4 hours. The reaction was then stopped by cooling to room temperature, yielding a solution containing polymer a-1. The molecular weight of the resulting polymer a-1 was measured by gel permeation chromatography (GPC) (in terms of polystyrene), and found to be Mn 4,700, Mw 6,130, and Mw / Mn 1.30. The reaction rates of the monomers measured by gas chromatography (GC) were BA: 80%, EA: 87%, TDA: 83%, and DMS: 100%. The nonvolatile content of the polymerization solution, measured by the above method, was 43.1%.

[0149] [Synthesis Examples 2 to 17 and Comparative Synthesis Examples 1 to 3] Production of Polymers a-2 to a-17 and ca-1 to ca-3 Polymers a-2 to a-17 and ca-1 to ca-3 were obtained by the same procedure as in Synthesis Example 1, except that the raw materials used were charged as shown in Tables 1 and 2. The molecular weight of each polymer, the non-volatile concentration of the polymerization solution, and the reaction rate of each monomer were measured and are shown in Tables 1 and 2. In Tables 1 and 2, "initial charge monomer" refers to the monomer charged into a 1-L flask (reactor) before the start of polymerization, and "continuously supplied monomer" refers to the monomer continuously supplied dropwise into the 1-L flask (reactor) over 2 hours immediately after the start of polymerization.

[0150] [Synthesis Example 18] Production of Polymer a-18 A 1 L flask equipped with a stirrer and a thermometer was charged with DBTTC (6.7 parts), BA (49.0 parts), EA (4.0 parts), TDA (25.0 parts), p-styryltrimethoxysilane (hereinafter also referred to as "STMS") (5.5 parts), ethyl acetate (24.0 parts), and MOA (12.0 parts), and one-third of the amount of V-65 (0.77 parts) was added to the 1 L flask, thoroughly degassed by nitrogen bubbling, and the temperature was raised to 75 ° C. to initiate polymerization. After the start of polymerization, three divided amounts of V-65 (0.77 parts) were added to the 1 L flask at 1.0 hour and 2.0 hours after the start of polymerization. In addition, STMS (16.5 parts) was divided into four portions and added at 0.5 hour, 1.0 hour, 1.5 hour, and 2.0 hours after the start of polymerization, respectively. Two hours after the start of polymerization, the temperature was raised to 80° C. over one hour, and the reaction was continued for another two hours at 80° C. Thereafter, the reaction was stopped by cooling to room temperature, and a solution containing polymer a-18 was obtained.

[0151]

[0152]

[0153] The abbreviations for the compounds in Tables 1 and 2 represent the following (the same applies to Tables 3 to 8): BA: n-butyl acrylate TDA: n-tetradecyl acrylate SA: octadecyl acrylate (stearyl acrylate) EA: ethyl acrylate MMA: methyl methacrylate DMS: methyldimethoxysilylpropyl methacrylate TMS: trimethoxysilylpropyl methacrylate MTMS: trimethoxysilylmethyl methacrylate STMS: p-styryltrimethoxysilane DBTTC: S,S-dibenzyltrithiocarbonate V-65: 2,2'-azobis(2,4-dimethylvaleronitrile) MOA: trimethyl orthoacetate

[0154] <Production of Triblock Copolymer> [Synthesis Example 19] Production of Triblock Copolymer b-1 A 1 L flask equipped with a stirrer and a thermometer was charged with a solution containing polymer a-1 obtained in Synthesis Example 1 (purity 47%, therefore, 5.3 parts as polymer a-1 (11.3 parts x 0.47 = 5.3 parts)), BA (71.0 parts), EA (4.8 parts), TDA (19.0 parts), 2,2'-azobis(2-methylbutyronitrile) (hereinafter also referred to as "ABN-E") (0.157 parts), ethyl acetate (16.0 parts) and MOA (4.0 parts), and the mixture was thoroughly degassed by nitrogen bubbling, and polymerization was initiated in a thermostatic bath at 70 ° C. Six hours after the start of polymerization, the reaction was stopped by cooling to room temperature to obtain a solution containing triblock copolymer b-1. The "purity" is a value (unit: %) expressed as the ratio of the total amount of monomers to the total amount charged during polymerization (total amount of monomers, control agent, initiator, and solvent). The molecular weight of the obtained triblock copolymer b-1 was Mn 70,000, Mw 97,000, and Mw / Mn 1.39. The reaction rates of each monomer measured by gas chromatography (GC) were BA: 92%, EA: 88%, and TDA: 90%. The obtained triblock copolymer b-1 has a polymer block (A) consisting of BA, EA, TDA, and DMS, and a polymer block (B) consisting of BA, EA, and TDA, and is a triblock copolymer having a block structure of (A)-(B)-(A) (polymer block (A) / polymer block (B) / polymer block (A)).

[0155] [Synthesis Examples 20 to 47 and Comparative Synthesis Examples 4 to 6] Production of triblock copolymers b-2 to b-29 and cb-1 to cb-3 Triblock copolymers b-2 to b-29 and cb-1 to cb-3 were obtained in the same manner as in Synthesis Example 19, except that the raw materials used were as shown in Tables 3 and 4. The molecular weight of each polymer and the reaction rate of each monomer were measured and are shown in Tables 3 and 4.

[0156]

[0157]

[0158] In Tables 3 and 4, the abbreviations for compounds other than those listed in Tables 1 and 2 represent the following: ABN-E: 2,2'-azobis(2-methylbutyronitrile)

[0159] <Preparation of Pentablock Copolymer> [Synthesis Example 48] Preparation of Pentablock Copolymer c-1 The solution containing the triblock copolymer b-1 obtained in Synthesis Example 19 (98.88 parts) and MOA (0.23 parts) were charged, thoroughly degassed by nitrogen bubbling, and heated to 60°C. After the internal temperature stabilized at 60°C, ABN-E (0.015 parts) was added to initiate polymerization. DMS (1.12 parts) was added in four portions at 0 hours, 0.5 hours, 1.0 hours, and 1.5 hours after the start of polymerization. Seven hours after the start of polymerization, the reaction was stopped by cooling to room temperature, and a solution containing pentablock copolymer c-1 was obtained. The molecular weight of the pentablock copolymer c-1 was Mn 69,000, Mw 103,000, and Mw / Mn 1.49. The reaction rates of each monomer measured by gas chromatography (GC) were 92% for BA, 91% for EA, 90% for TDA, and 99% for DMS. The resulting pentablock copolymer c-1 had a polymer block (A) consisting of BA, EA, TDA, and DMS, and a polymer block (B) consisting of BA, EA, and TDA, and was a pentablock copolymer having a block structure of (A)-(B)-(A)-(B)-(A) (polymer block (A) / polymer block (B) / polymer block (A) / polymer block (B) / polymer block (A)). The composition ratio of polymer block (A) to polymer block (B) calculated from the polymerization rate was (A) / (B) ≈ 15 / 85 (wt %).

[0160] [Synthesis Examples 49 to 77 and Comparative Synthesis Examples 7 to 9] Production of pentablock copolymers c-2 to c-30 and cc-1 to cc-3 Pentablock copolymers c-2 to c-30 and cc-1 to cc-3 were obtained by the same procedure as in Synthesis Example 48, except that the raw materials used were as shown in Tables 5 and 6. The molecular weights of each polymer were measured and are shown in Tables 5 and 6. The compositional ratios of polymer block (A) and polymer block (B) were also calculated and are shown in Tables 5 and 6.

[0161]

[0162]

[0163] <Post-treatment Steps of Pentablock Copolymer> [Production Example 1] Production of Triblock Copolymer d-1 A solution containing block copolymer c-1 (100.0 parts) obtained in Synthesis Example 48 was thoroughly degassed by nitrogen bubbling, and then n-propylamine (0.36 parts) was charged, and the decomposition reaction of the thiocarbonyl group was initiated in a thermostatic bath at 40°C. After 5 hours, the reaction was stopped by cooling to room temperature, yielding a solution containing block copolymer d-1. The solution containing block copolymer d-1 was reduced in pressure to 20 kPa, and volatile components (unreacted monomers, solvent, etc.) were continuously distilled off using a thin-film evaporator maintained at 120°C, and the non-volatile component, block copolymer d-1, was recovered. Block copolymer d-1 is a triblock copolymer having a block structure of (A)-(B)-(A) (polymer block (A) / polymer block (B) / polymer block (A)) that includes a polymer block (A) consisting of BA, EA, TDA, and DMS, and a polymer block (B) consisting of BA, EA, and TDA, and is a Michael adduct of a thiol formed by decomposition of the thiocarbonylthio group of block copolymer c-1 with an amine and a residual acrylate compound contained in block copolymer c-1. １H-NMR analysis confirmed that the peak (4.8 ppm) of hydrogen bonded to the carbon adjacent to the thiocarbonylthio group observed in block copolymer c-1 disappeared in block copolymer d-1, and peaks (3.3 ppm, 2.9 ppm) derived from a Michael adduct with the residual acrylate compound (terminal molecular structure represented by the following general formula (3)) appeared. Furthermore, the molecular weight of block copolymer d-1 was Mn 41,600, Mw 71,400, and Mw / Mn = 1.72. The polymer composition calculated from the monomer charge ratio and the reaction rate of each monomer measured by gas chromatography (GC) was BA units: 73.4 mass%, TDA units: 19.5 mass%, EA units: 4.9 mass%, and DMS units: 2.2 mass%. The average number of crosslinkable silyl groups per molecule was calculated to be 4.0. The block copolymer d-1 had an E-type viscosity of 198 Pa s. Furthermore, a dumbbell for a tensile test (JIS K 6251 No. 2 type) was prepared using the block copolymer d-1, and the recovery rate and tensile properties were measured. The recovery rate was 84%, the elongation at break (EI) was 339%, the strength at break (Ts) was 0.25 MPa, and the strength at 50% elongation (M50) was 0.06 MPa.

[0164]

[0165] [Production Examples 2 to 30 and Comparative Production Examples 1 to 3] Block copolymers d-2 to d-30 and cd-1 to cd-3 were obtained by the same procedure as in Production Example 1, except that the raw materials used were as shown in Tables 7 and 8 and the desolvation temperature was appropriately adjusted. The molecular weight, polymer composition, average number of crosslinkable silyl groups per molecule, viscosity, recovery rate, and tensile properties of each polymer were measured and are shown in Tables 7 and 8.

[0166]

[0167]

[0168] Comparative Production Example 4: Production of Telechelic Polymer Copper(I) bromide (0.25 parts), pentamethyldiethylenetriamine (1.00 g), BA (302.4 g), TDA (80.4 g), EA (20.1 g), and anisole (247 g) were charged into a 1 L flask equipped with a stirrer and a thermometer, and the mixture was thoroughly degassed by bubbling with nitrogen. Ethylene bis(2-bromoisobutyrate) (1.37 g) was added, and polymerization was initiated in a thermostatic bath at 80°C. Six hours after the initiation of polymerization, volatiles were removed by heating and stirring under reduced pressure at 80°C. To this mixture, acetonitrile (200 g), 1,7-octadiene (15.4 g), and pentamethyldiethylenetriamine (1.21 g) were added, and stirring was continued for 8 hours. The mixture was heated and stirred under reduced pressure at 80°C to remove volatiles, yielding a polymer-containing concentrate (1). Toluene was added to the concentrate (1) to dissolve the polymer, and then diatomaceous earth was added as a filter aid, aluminum silicate as an adsorbent, and hydrotalcite was added. The mixture was heated and stirred at an internal temperature of 100 ° C. under an oxygen-nitrogen mixed gas atmosphere (oxygen concentration 6%). The solids in the mixture were removed by filtration, and the filtrate was heated and stirred at an internal temperature of 100 ° C. under reduced pressure to remove volatiles, yielding a polymer-containing concentrate (2). Furthermore, per 100 parts by mass of the concentrate (2), 3 parts by mass of aluminum silicate as an adsorbent, 3 parts by mass of hydrotalcite, and 0.5 parts by mass of Irganox 1010 (manufactured by BASF) as an antioxidant were added, and the mixture was heated and stirred under reduced pressure (vacuum pressure of 10 Torr or less, average temperature about 175 ° C.) to obtain a treated liquid (1). Next, 3 parts by mass of aluminum silicate as an adsorbent, 3 parts by mass of hydrotalcite, and 0.5 parts by mass of Irganox 1010 (manufactured by BASF) as an antioxidant were added to 100 parts by mass of the treatment liquid (1), and the mixture was heated and stirred in an oxygen-nitrogen mixed gas atmosphere (oxygen concentration 6%) at an internal temperature of 150° C. Subsequently, toluene was added, and then the solid content in the mixture was removed by filtration. The filtrate was heated and stirred under reduced pressure at an internal temperature of 60° C. to remove volatile components, thereby obtaining a polymer having alkenyl groups.The polymer having alkenyl groups, dimethoxymethylsilane (2.97 g), methyl orthoformate (1.49 g), and platinum catalyst [a xylene solution of bis(1,3-divinyl-1,1,3,3-tetramethyldisiloxane) platinum complex catalyst: hereinafter referred to as platinum catalyst] (10 mg of platinum per kg of polymer) were mixed and stirred under a nitrogen atmosphere at 100°C to obtain a reaction mixture. The alkenyl groups were confirmed to have disappeared. １ The reaction mixture was concentrated under reduced pressure at an internal temperature of 60°C to obtain a polymer (referred to as polymer cd-4) which was poly(n-butyl acrylate) having dimethoxysilyl groups at its terminals. The molecular weight of the obtained polymer cd-4 was measured to be Mn 42,000, Mw 54,300, and Mw / Mn 1.29. The average number of crosslinkable silyl groups introduced per molecule of polymer cd-4 was also measured. １ The number of units was calculated to be 2.0 by H-NMR analysis. The E-type viscosity of polymer cd-4 was 205 Pa s. Furthermore, a dumbbell for a tensile test (JIS K 6251 No. 2 type) was prepared using polymer cd-4, and the recovery rate and tensile properties were measured. The recovery rate was 58%, the breaking strength (Ts) was 0.30 MPa, the strength at 50% elongation (M50) was 0.09 MPa, and the breaking elongation (El) was 353%.

[0169] <<Production and Evaluation of Curable Resin Compositions>> <Production of Curable Resin Composition> [Example 1] Using the block copolymer d-1 obtained in Production Example 1 as the vinyl polymer base resin, each component was blended according to the blending ratio shown in Table 9 below, to prepare a curable resin composition according to a conventional method.

[0170]

[0171] Details of the compounds in Table 9 are as follows:・Polyoxyalkylene polymer: modified silicone Excestar ES-S4530 (manufactured by AGC) ・UP-1020: acrylic plasticizer, ARUFON (registered trademark) UP-1020 (manufactured by Toagosei Co., Ltd.) ・Light calcium carbonate: Viscolite-EL20 (manufactured by Shiraishi Calcium Co., Ltd.) ・Heavy calcium carbonate: Super SS (manufactured by Maruo Calcium Co., Ltd.) ・R-820: titanium oxide R-820 (manufactured by Ishihara Sangyo Kaisha, Ltd.) ・B75: antioxidant, Tinuvin B75 (manufactured by Ciba Specialty Co., Ltd.) ・SH6020: 3-(2-aminoethylamino)propyltrimethoxysilane, SH6 020 (manufactured by Dow Corning Toray Co., Ltd.) ・SZ6300: vinyltrimethoxysilane, SZ6300 (manufactured by Dow Corning Toray Co., Ltd.) U-220H: tin catalyst (dibutyltin diacetylacetonate), Neostan U-220H (manufactured by Nitto Kasei Co., Ltd.)

[0172] Examples 2 to 30, Comparative Examples 1 to 4 Using the vinyl polymers obtained in Production Examples 2 to 30 and Comparative Production Examples 1 to 4, curable resin compositions were prepared in the same manner as in Example 1.

[0173] <Evaluation> The curable resin compositions prepared above were evaluated by the following methods. The evaluation results are shown in Tables 10, 11, and 12.

[0174] (Tensile Properties) Each curable resin composition was applied to a Teflon (registered trademark) sheet at room temperature (25°C) to a thickness of 2 mm, and then aged for 5 days at 23°C and 50% RH (relative humidity), followed by aging for 1 day in a saturated steam atmosphere at 50°C to produce a cured sheet. A dumbbell for tensile testing was prepared from the resulting cured sheet, and measurements were performed using a tensile tester (Autograph AGS-J, manufactured by Shimadzu Corporation). The shape of the dumbbell for tensile testing was based on Type 3 of JIS K 6251, a Japanese Industrial Standard. Specifically, the strength at 50% elongation (M50, unit: MPa), breaking strength (Ts, unit: MPa), and breaking elongation (El1, unit: %) were measured at a tensile speed of 200 mm / min under conditions of 23°C and 50% humidity.

[0175] (Heat Resistance) The above-mentioned dumbbells for tensile testing were heated in a dryer at 100°C for 42 days, and then aged for 1 day under conditions of 23°C and 50% RH (relative humidity). Thereafter, a tensile test was carried out using a tensile tester (Autograph AGS-J, manufactured by Shimadzu Corporation) at a tensile speed of 200 mm / min, and the breaking elongation (El ２ , unit %) was measured, and the retention rate of breaking elongation (El ２ The greater the retention rate of elongation at break and the greater the value of elongation at break, the more excellent the heat resistance.

[0176] (Recovery Rate) The above-mentioned tensile test dumbbell was stretched at a rate of 5 mm / min using a tensile tester (Autograph AGS-J, manufactured by Shimadzu Corporation) so that the gauge length (dumbbell No. 3: 20 mm) became 40 mm, and this was maintained for 24 hours. Next, the tensile test dumbbell was removed from the tensile tester and placed on a 2 mm thick Teflon (registered trademark) sheet, and after 1 hour, the length between the gauge lines (L2) was measured. The measurement was carried out in an environment of a temperature of 23°C and 50% RH. The recovery rate was calculated using the following formula when the test specimen could be stretched under the above measurement conditions and recovery behavior was observed in the test specimen removed from the tensile tester. Recovery rate [%] = (L １ -L ２ ) / (L １ -L ０ ) × 100 where L ０ L: Gauge distance before extension [mm] １ : Gauge distance when extended [mm] L ２ : Gauge length [mm] 1 hour after removal from the tensile tester. Here, L ０ = 20 [mm], L １ = 40 [mm].

[0177] (Workability) Each curable resin composition was applied to a substrate with a trowel, and the ease of application of the curable resin composition (liquid) was evaluated according to the following criteria. ⊚: The curable resin composition can be spread smoothly when the temperature is 5°C. ◯: The trowel becomes heavy and it is difficult to spread when the temperature is 5°C, but it can be spread smoothly at 10°C or higher. Δ: The trowel becomes heavy and it is difficult to spread when the temperature is 10°C, but it can be spread smoothly at 23°C. ×: The trowel is heavy even when the temperature of the curable resin composition is 23°C, and it cannot be spread smoothly.

[0178] (Weather Resistance) Each curable resin composition was applied to a Teflon (registered trademark) sheet at room temperature (25°C) to a thickness of 2 mm, and then aged for 5 days under conditions of 23°C and 50% RH (relative humidity), and then for 1 day in a saturated water vapor atmosphere at 50°C to produce a cured sheet. The obtained cured sheet was placed in a metaling weather meter (DAIPLA METAL WEATHER KU-R5NCI-A manufactured by Daipla Wintes Co., Ltd.) and subjected to an accelerated weather resistance test. The irradiation conditions were 63°C, 70% RH, and an illuminance of 80 mW / cm. ２ The test was carried out with a 2-minute shower once every 2 hours. After 600 hours, 900 hours, and 1200 hours, the surface condition was visually inspected to evaluate the weather resistance based on the presence or absence of cracks on the surface and the degree of wrinkles and slack, and the evaluation was made based on the following criteria: ○: No change in surface condition; △: No cracks, but wrinkles and slack have occurred; ×: Cracks have occurred.

[0179] (Dynamic Weathering Resistance) The cured sheets prepared in the above weathering resistance evaluation were cut into 15 mm x 70 mm strips to prepare test specimens. The cut test specimens were placed in a metaling weather meter (DAIPLA METAL WEATHER KU-R5NCI-A manufactured by Daipla Wintes) and subjected to an accelerated weathering test. The irradiation conditions were 63°C, 70% RH, and an illuminance of 80 mW / cm. ２The test was carried out with a 2-minute shower once every 2 hours. After 300 hours, the test specimen was stretched at a rate of 5 mm / min using a tensile tester under conditions of 23°C and 50% RH so that the gauge length was 60 mm (at 100% elongation). Two gauge lines were marked in the center of the strip-shaped test specimen so that the gauge length was 30 mm. The surface condition (between the gauge lines, stretched portion) was visually inspected to evaluate the presence or absence of cracks on the surface, and judged based on the following criteria: ○: No change in surface condition; △: Partial cracks occurred; ×: Cracks occurred over the entire surface.

[0180]

[0181]

[0182]

[0183] As is clear from the results of Examples 1 to 30, the sealants containing vinyl polymers d-1 to d-30 were excellent in weather resistance (particularly dynamic weather resistance). Furthermore, the curable resin compositions of Examples 6, 10, 11, 15, 16, and 19, which contained vinyl polymers containing relatively large amounts of (meth)acrylic acid alkyl esters having an alkyl group having 10 or more carbon atoms, were also excellent in workability.

[0184] On the other hand, Comparative Examples 1 to 4, which used vinyl polymers cd-1 to cd-4, had poor weather resistance (particularly dynamic weather resistance). A detailed study revealed that the vinyl polymers cd-1 and cd-2 used in Comparative Examples 1 and 2 were prepared by adding the entire amount of the hydrolyzable silyl group-containing vinyl compound at the start of polymerization when synthesizing the polymer block (A), which presumably prevented the crosslinkable silyl groups from being uniformly introduced between the polymer molecules. Therefore, when the polymers were cured, a uniform crosslinked structure was not formed, which is thought to have reduced weather resistance.

[0185] The vinyl polymer CD-3 used in Comparative Example 3 had an average number of crosslinkable silyl groups of 1.5, and it is believed that the cured product produced using this vinyl polymer CD-3 had a low crosslink density and insufficient weather resistance. The vinyl polymer CD-4 used in Comparative Example 4 is a telechelic polymer (having crosslinkable silyl groups at the polymer terminals), with one crosslinkable silyl group at each terminal. This telechelic polymer had a lower crosslink density than the vinyl polymers D-1 to D-30, and its recovery rate was insufficient, which is believed to have resulted in reduced weather resistance (particularly dynamic weather resistance).

[0186] As described above, the vinyl polymer of the present disclosure has excellent tensile properties (elongation at break and strength at break) and recovery properties, and also exhibits good fluidity (low viscosity), resulting in excellent handleability. Such a vinyl polymer of the present disclosure can be widely applied in various fields, including coatings for automobile parts, electrical appliances, and medical-related products, packings, gaskets, and hose materials, as well as adhesive raw materials, construction and civil engineering components, and daily necessities. Furthermore, a curable resin composition containing the vinyl polymer of the present disclosure exhibits high weather resistance (particularly dynamic weather resistance) and heat resistance. Therefore, the curable resin composition can be used as an adhesive, a sealant, a paint, a coating agent, a molding material, a rubber sheet, and the like, and is particularly suitable for use as a sealant.

[0187] The present invention is not limited to the above-described embodiments, and encompasses various modifications and equivalent modifications within the scope of the spirit of the present invention. Therefore, in light of the above teachings, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are to be understood as falling within the scope and spirit of the present invention.

Claims

1. A vinyl polymer having a crosslinkable functional group, the vinyl polymer having a cured product with a recovery rate of 75% or more and a breaking elongation of 300 to 600%.

2. The vinyl polymer according to claim 1, wherein the average number of said crosslinkable functional groups per molecule is 1.8 or more.

3. The vinyl polymer according to claim 1, which contains structural units derived from an alkyl (meth)acrylate ester having an alkyl group having 10 or more carbon atoms in the ester moiety in an amount of 0.1 to 50 mass % based on the total structural units constituting the vinyl polymer.

4. The vinyl polymer according to claim 1, wherein the proportion of structural units derived from an alkyl (meth)acrylate ester having an alkyl group having 2 or less carbon atoms in the ester moiety is 20 mass% or less based on the total structural units constituting the vinyl polymer.

5. The vinyl polymer according to claim 1, comprising 0.1 to 50% by mass of structural units derived from (meth)acrylic acid alkyl esters having an alkyl group with 10 or more carbon atoms in the ester moiety relative to all structural units constituting the vinyl polymer, and the proportion of structural units derived from (meth)acrylic acid alkyl esters having an alkyl group with 2 or less carbon atoms in the ester moiety is 20% by mass or less relative to all structural units constituting the vinyl polymer.

6. The vinyl polymer according to claim 1, which is a block copolymer consisting of polymer block (A) / polymer block (B) / polymer block (A).

7. The vinyl polymer according to claim 6, wherein the polymer block (A) has the crosslinkable functional group.

8. The vinyl polymer according to claim 1, having a weight average molecular weight (Mw) of 30,000 to 100,000 and a molecular weight distribution (Mw / Mn) of 1.80 or less.

9. A curable resin composition comprising: the vinyl polymer according to any one of claims 1 to 8; and an oxyalkylene polymer having a crosslinkable silyl group.

10. The curable resin composition according to claim 9, wherein a mass ratio of the vinyl polymer to the oxyalkylene polymer, expressed as vinyl polymer / oxyalkylene polymer, is 10 / 90 to 90 / 10.

11. The curable resin composition according to claim 9, which is for use as a sealant, adhesive, pressure sensitive adhesive or coating material.

12. A method for producing a vinyl polymer according to any one of claims 1 to 8, comprising a polymerization step of polymerizing a vinyl monomer, the vinyl monomer comprising a vinyl monomer having a crosslinkable functional group, and in the polymerization step, polymerization is carried out while continuously or intermittently supplying into a reactor at least a portion of the total amount of the vinyl monomer having a crosslinkable functional group used in the production of the vinyl polymer.

13. The method for producing a vinyl polymer according to claim 12, wherein the vinyl polymer is produced by living radical polymerization.

14. A method for producing a vinyl polymer having a crosslinkable functional group, wherein the vinyl polymer is a block copolymer consisting of polymer block (A) / polymer block (B) / polymer block (A), and the average number of the crosslinkable functional groups per molecule is 1.8 or more, the method comprising: a first polymerization step of polymerizing a vinyl monomer in the presence of a living radical polymerization control agent and a polymerization initiator to obtain the polymer block (A); and a second polymerization step of polymerizing a vinyl monomer in the presence of the polymer block (A) obtained in the first polymerization step and a polymerization initiator to form the polymer block (B), wherein the vinyl monomer used in the first polymerization step includes a vinyl monomer having a crosslinkable functional group, and in the first polymerization step, polymerization is carried out while continuously or intermittently supplying into a reactor at least a portion of the total amount of the vinyl monomer having a crosslinkable functional group used to produce the polymer block (A).

15. The method for producing a vinyl polymer according to claim 14, wherein the living radical polymerization inhibitor is a polymerization inhibitor of the exchange chain transfer mechanism type.

16. The method for producing a vinyl polymer according to claim 14 or 15, wherein the ratio of the vinyl monomer having a crosslinkable functional group to be continuously or intermittently fed into a reactor is 10 to 100 mass % based on the total amount of the vinyl monomer having a crosslinkable functional group used in the production of the polymer block (A).

Images