Curable composition and cured product

Abstract

The present invention provides a curable composition that exhibits excellent mechanical properties in the cured product while suppressing an increase in viscosity. [Solution] The curable composition according to the present disclosure comprises a (meth)acrylic copolymer (A) having reactive silicon groups and a polyoxyalkylene polymer (B) having reactive silicon groups, wherein the proportion of molecules with a number average molecular weight of 100,000 or more in the (meth)acrylic copolymer (A) is 7% by weight or less, and the number average molecular weight of the polyoxyalkylene polymer (B) is 15,000 or more.

Description

[Technical Field]

[0001] This invention relates to curable compositions and cured products. [Background technology]

[0002] Conventionally, curable compositions obtained by mixing a linear polyoxyalkylene polymer having alkoxysilyl groups with a branched polyoxyalkylene polymer having alkoxysilyl groups are known (for example, Patent Document 1). Such curable compositions are used in a wide range of applications such as sealants, adhesives, and paints. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2021 / 157584 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the conventional technologies described above had room for improvement in terms of the viscosity of the curable composition and the mechanical properties of the cured product. One aspect of the present invention aims to realize a curable composition that has excellent mechanical properties of the cured product while suppressing an increase in viscosity. [Means for solving the problem]

[0005] To solve the above problems, a curable composition according to one aspect of the present invention is a curable composition comprising a (meth)acrylic copolymer (A) having reactive silicon groups and a polyoxyalkylene polymer (B) having reactive silicon groups, wherein the proportion of molecules with a number average molecular weight of 100,000 or more in the (meth)acrylic copolymer (A) is 7.0% by weight or less, and the number average molecular weight of the polyoxyalkylene polymer (B) is 15,000 or more. [Effects of the Invention]

[0006] According to one aspect of the present invention, it is possible to provide a curable composition that has excellent mechanical properties in the cured product while suppressing an increase in viscosity. [Modes for carrying out the invention]

[0007] One embodiment of the present invention will be described in detail below. Unless otherwise specified in this specification, "A to B" representing a numerical range means "greater than or equal to A and less than or equal to B".

[0008] [1. Curable composition] A curable composition according to one embodiment of the present invention comprises a (meth)acrylic copolymer (A) having reactive silicon groups and a polyoxyalkylene polymer (B) having reactive silicon groups, wherein the proportion of molecules with a number average molecular weight of 100,000 or more in the (meth)acrylic copolymer (A) is 7.0% by weight or less, and the number average molecular weight of the polyoxyalkylene polymer (B) is 15,000 or more. Hereinafter, the (meth)acrylic copolymer (A) having reactive silicon groups will also be referred to as polymer (A), and the polyoxyalkylene polymer (B) having reactive silicon groups will also be referred to as polymer (B).

[0009] In a curable composition obtained by mixing a (meth)acrylic copolymer having reactive silicon groups and a polyoxyalkylene polymer having reactive silicon groups, it is generally necessary to increase the molecular weight of both the (meth)acrylic copolymer and the polyoxyalkylene polymer from the viewpoint of improving the mechanical properties of the cured product.

[0010] However, mixtures of high molecular weight polymers can increase viscosity and reduce workability. Furthermore, when the inventors investigated various combinations of (meth)acrylic copolymers and polyoxyalkylene polymers, they found that polyoxyalkylene polymers with a number average molecular weight of 15,000 or more may have compatibility issues with (meth)acrylic copolymers.

[0011] As a result of further intensive research by the inventors, it was found that a (meth)acrylic copolymer (polymer (A)) having a proportion of molecules with a number average molecular weight of 100,000 or more of 7.0% by weight or less exhibits good compatibility and suppresses viscosity increase even when mixed with a polyoxyalkylene polymer (polymer (B)) having a number average molecular weight of 15,000 or more. Furthermore, it was found that the cured product obtained from a curable composition containing polymer (A) and polymer (B) in this manner exhibits excellent mechanical properties.

[0012] In this specification, suppression of viscosity increase means that the viscosity of the curable composition is lower than that of polymer (A) alone or polymer (B) alone. The viscosity of the curable composition can be measured by the method described in the examples.

[0013] In this specification, "excellent mechanical properties of a cured product" means that it is superior to a cured product obtained from a curable composition that does not contain polymer (A) and / or polymer (B) in at least fracture stress and fracture elongation. The fracture stress and fracture elongation of the cured product can be measured by the method described in the examples.

[0014] <1-1. (Meth)acrylic copolymer (A)> The curable composition comprises a (meth)acrylic copolymer (A) having reactive silicon groups. In this specification, (meth)acrylic means acrylic and / or methacrylic.

[0015] Examples of reactive silicon groups include the reactive silicon group represented by the following formula (1): -Si(R 3 ) 3-a (X) a (1) (In the formula, R 3 Each of these independently represents a substituted or unsubstituted hydrocarbon group with 1 to 20 carbon atoms, and R 3 (The group may be substituted with a heteroatom-containing group. Each X independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3.) The reactive silicon group has a hydroxyl group or a hydrolyzable group on a silicon atom, so it can form a siloxane bond through hydrolysis and condensation reactions.

[0016] R 1 The number of carbon atoms of the hydrocarbon group in is preferably 1 to 10, more preferably 1 to 5, and still more preferably 1 to 3. R 1 Specific examples include a methyl group, an ethyl group, a chloromethyl group, a methoxymethyl group, and an N,N-diethylaminomethyl group. Preferably, R 1 is a methyl group, an ethyl group, a chloromethyl group, or a methoxymethyl group, and more preferably a methyl group or a methoxymethyl group.

[0017] Examples of the hydrolyzable group for X include a halogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group, an alkenyloxy group, and the like. Among these, alkoxy groups such as a methoxy group and an ethoxy group are more preferable because their hydrolysis property is mild and easy to handle, and a methoxy group and an ethoxy group are particularly preferable. A reactive silicon group having an alkoxy group as a hydrolyzable group is also specifically referred to as an alkoxysilyl group.

[0018] Specific examples of reactive silicon groups include, but are not limited to: trimethoxysilyl group, triethoxysilyl group, tris(2-propenyloxy)silyl group, triacetoxysilyl group, methyldimethoxysilyl group, methyldiethoxysilyl group, ethyldimethoxysilyl group, (chloromethyl)dimethoxysilyl group, (chloromethyl)diethoxysilyl group, (methoxymethyl)dimethoxysilyl group, (methoxymethyl)diethoxysilyl group, (N,N-diethylaminomethyl)dimethoxysilyl group, and (N,N-diethylaminomethyl)diethoxysilyl group. Among these, methyldimethoxysilyl group, trimethoxysilyl group, triethoxysilyl group, (chloromethyl)dimethoxysilyl group, (methoxymethyl)dimethoxysilyl group, (methoxymethyl)diethoxysilyl group, and (N,N-diethylaminomethyl)dimethoxysilyl group are preferable because they exhibit high activity and allow obtaining a cured product having good mechanical properties. From the viewpoint of excellent shape retention after application of the curable composition, a methyldimethoxysilyl group is preferable. From the viewpoints of good initial strength development of the cured product and obtaining a highly rigid cured product, a trimethoxysilyl group is preferable.

[0019] The number of reactive silicon groups represented by formula (1) contained in polymer (A) is preferably 0.5 or more per molecule, may be more than 0.5, and may be 1.0 or more. The number of reactive silicon groups contained in polymer (A) is preferably 10.0 or less per molecule, more preferably 6.0 or less, still more preferably 2.0 or less, and particularly preferably 1.5 or less. When the number of reactive silicon groups falls within the above range, the physical properties of the curable composition and the cured product become better.

[0020] The main chain of polymer (A) mainly consists of structural units derived from (meth)acrylic acid ester monomers. The structural units derived from (meth)acrylic acid ester monomers preferably account for 50% or more by weight of the total weight of the main chain in polymer (A), more preferably 70% or more by weight, and even more preferably 90% or more by weight. Examples of (meth)acrylic acid ester monomers include (meth)acrylic acid ester monomers without reactive silicon groups and (meth)acrylic acid ester monomers having reactive silicon groups.

[0021] Examples of (meth)acrylic acid ester monomers that do not have a reactive silicon group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2- Examples include butoxyethyl, isopropoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, 2-aminoethyl (meth)acrylate, ethylene oxide adducts of (meth)acrylic acid, trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, perfluoromethyl perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate. Only one of these may be used, or two or more may be used.

[0022] Examples of (meth)acrylic acid ester monomers having a reactive silicon group include 3-(trimethoxysilyl)propyl (meth)acrylate, 3-(triethoxysilyl)propyl (meth)acrylate, 3-(methyldimethoxysilyl)propyl (meth)acrylate, 3-(methyldiethoxysilyl)propyl (meth)acrylate, 2-(trimethoxysilyl)ethyl (meth)acrylate, 2-(methyldimethoxysilyl)ethyl (meth)acrylate, (trimethoxysilyl)methyl (meth)acrylate, (triethoxysilyl)methyl (meth)acrylate, (methyldimethoxysilyl)methyl (meth)acrylate, and 3-((methoxymethyl)dimethoxysilyl)propyl (meth)acrylate. One of these may be used, or two or more may be used.

[0023] From the viewpoint of exhibiting good compatibility with polymer (B), polymer (A) preferably contains structural units derived from highly polar monomers and structural units derived from low-polarity monomers. Examples of highly polar monomers include (meth)acrylic acid ester monomers having an alkyl group or alkoxyalkyl group with 1 to 3 carbon atoms. Examples of low-polarity monomers include (meth)acrylic acid ester monomers having an alkyl group with 8 to 20 carbon atoms.

[0024] Examples of highly polar monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, and 2-methoxyethyl (meth)acrylate. From the viewpoint of exhibiting good compatibility with polymer (B), it is preferable that the highly polar monomer is one or more selected from the group consisting of methyl methacrylate, methyl acrylate, ethyl acrylate, and 2-methoxyethyl acrylate.

[0025] Examples of low-polarity monomers include n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate. From the viewpoint of exhibiting good compatibility with polymer (B), it is preferable that the low-polarity monomer is one or more selected from the group consisting of 2-ethylhexyl acrylate, n-octyl acrylate, dodecyl acrylate, and octadecyl acrylate.

[0026] Polymer (A) preferably contains 5% to 30% by weight of structural units derived from the high-polarity monomer, more preferably 10% to 25% by weight, and even more preferably 10% to 20% by weight. If the content of structural units derived from the high-polarity monomer is 5% by weight or more, the compatibility with polymer (B) is further improved. If the content of structural units derived from the high-polarity monomer is 30% by weight or less, the viscosity can be further reduced.

[0027] Furthermore, polymer (A) preferably contains 15% to 38% by weight of structural units derived from the low-polarity monomer, more preferably 15% to 35% by weight, and even more preferably 15% to 30% by weight. If the content of structural units derived from the low-polarity monomer is 15% by weight or more, the compatibility with polymer (B) is further improved. If the content of structural units derived from the low-polarity monomer is 38% by weight or less, the viscosity can be further reduced.

[0028] In other words, from the viewpoint of compatibility and viscosity, it is preferable that polymer (A) contains 5% to 30% by weight of constituent units derived from the high-polarity monomer and 15% to 38% by weight of constituent units derived from the low-polarity monomer.

[0029] In polymer (A), the molar ratio of constituent units derived from high-polarity monomers to constituent units derived from low-polarity monomers is preferably 3.0 or less, but may be 2.0 or less. If the molar ratio is 3.0 or less, the viscosity can be further reduced. The lower limit of the molar ratio is not particularly limited, but may be, for example, 0.5 or more, or 1.0 or more.

[0030] The number-average molecular weight of polymer (A) is preferably 4,000 to 80,000, more preferably 5,000 to 50,000, and even more preferably 5,000 to 30,000. If the number-average molecular weight is 4,000 or higher, the properties of polymer (A) can be fully exhibited. If the number-average molecular weight is 80,000 or lower, the viscosity will not become too high, and sufficient workability can be ensured.

[0031] The molecular weight distribution (weight-average molecular weight / number-average molecular weight) of polymer (A) is preferably 5.0 or less, more preferably 4.0 or less, and even more preferably 3.0 or less. A smaller molecular weight distribution tends to reduce the viscosity of the curable composition and improve workability.

[0032] Weight-average molecular weight and number-average molecular weight can be measured, for example, by gel permeation chromatography (GPC). For GPC measurements, chloroform can be used as the mobile phase and a polystyrene gel column as the stationary phase. Furthermore, these molecular weights can be calculated in terms of polystyrene equivalents.

[0033] In polymer (A), the proportion of molecules with a number average molecular weight of 100,000 or more is 7.0% by weight or less, preferably 5.0% by weight or less, and more preferably 3.0% by weight or less. The proportion of molecules with a number average molecular weight of 100,000 or more may be 0% by weight or more. The proportion of molecules with a number average molecular weight of 100,000 or more can be determined from the integrated molecular weight distribution curve obtained by GPC measurement, and more specifically, it can be measured by the method of the examples.

[0034] The polymerization method for polymer (A) is not particularly limited and includes free radical polymerization and living radical polymerization. These polymerization methods are disclosed in the above-mentioned Patent Document 1, Japanese Patent Publication No. 2007-302749, Japanese Patent Publication No. 3-14068, Japanese Patent Publication No. 4-55444, Japanese Patent Publication No. 6-211922, etc.

[0035] From the viewpoint of easily obtaining polymer (A) in which the proportion of molecules with a number average molecular weight of 100,000 or more is 7% by weight or less, free radical polymerization is preferred. Free radical polymerization is a method that uses an azo compound or peroxide as a polymerization initiator and randomly copolymerizes (meth)acrylic acid ester monomers having reactive silicon groups and (meth)acrylic acid ester monomers not having reactive silicon groups. When this method is used, reactive silicon groups tend to be randomly introduced into the main chain of polymer (A).

[0036] The polymer (A) may contain a (meth)acrylic random copolymer (Aa) that contains constituent units derived from (meth)acrylic acid ester monomers having reactive silicon groups and constituent units derived from (meth)acrylic acid ester monomers not having reactive silicon groups. The (meth)acrylic random copolymer (Aa) may have a molecular weight distribution of 2.0 or more. Such a (meth)acrylic random copolymer (Aa) is easily obtained by the free radical polymerization method. The polymer (A) may consist only of the (meth)acrylic random copolymer (Aa).

[0037] <1-2. Polyoxyalkylene polymer (B)> The curable composition contains a polyoxyalkylene polymer (B) having a reactive silicon group. The reactive silicon group is the same as the reactive silicon group represented by formula (1) described in the section on polymer (A).

[0038] The number of reactive silicon groups in polymer (B) is preferably more than 0.5 per molecule, more preferably 1.2 to 6.0, and even more preferably 1.5 to 2.5. If the number of reactive silicon groups is within the above range, the curable composition can be given good curability.

[0039] The reactive silicon groups in polymer (B) are preferably located at at least one end of the molecule, and more preferably at both ends. If the reactive silicon groups are located at the ends of the molecule, the cured product can be given good rubber elasticity. A polymer (B) in which the reactive silicon groups are located at one end of the molecule and a polymer (B) in which the reactive silicon groups are located at both ends of the molecule may be used in combination.

[0040] The main chain skeleton of polymer (B) is a polymer having repeating units represented by the following general formula (2): -RO- (2) In general formula (2), R is an alkylene group having 1 to 14 carbon atoms. More preferably, R is an alkylene group having 2 to 4 carbon atoms. Examples of repeating units represented by general formula (2) include -CH2O-, -CH2CH2O-, -CH2CH(CH3)O-, -CH2CH(C2H5)O-, -CH2C(CH3)2O-, -CH2CH2CH2CH2O-, etc. Polymer (B) may consist of only one type of repeating unit, or it may consist of two or more types of repeating units.

[0041] Specific examples of the main chain skeleton of polymer (B) include polyacetal, polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, and polyoxypropylene-polyoxybutylene copolymer. Among these, polyoxypropylene is preferred.

[0042] The structure represented by general formula (2) preferably accounts for 50% or more by weight of the total weight of the main chain in polymer (B), more preferably 70% or more by weight, and even more preferably 90% or more by weight. Polymer (B) may contain urethane bonds or urea bonds in its main chain structure.

[0043] The molecular weight distribution (weight-average molecular weight Mw / number-average molecular weight Mn) of polymer (B) is not particularly limited, but is preferably narrow. Specifically, it is preferably less than 2.0, more preferably 1.6 or less, even more preferably 1.5 or less, and particularly preferably 1.4 or less. Furthermore, from the viewpoint of improving various mechanical properties such as the durability and elongation of the cured product, the molecular weight distribution of the polyoxyalkylene polymer is preferably 1.2 or less. The molecular weight distribution of polymer (B) can be determined from the number-average molecular weight and weight-average molecular weight obtained by gel permeation chromatography (GPC) measurement.

[0044] The number-average molecular weight of polymer (B), as measured by GPC in terms of polystyrene-equivalent molecular weight, is preferably 15,000 or more, more preferably 18,000 or more, and more preferably 20,000 or more. Furthermore, the number-average molecular weight of polymer (B) is preferably 50,000 or less, more preferably 40,000 or less, and even more preferably 30,000 or less. If the number-average molecular weight of polymer (B) is within the above range, mixing it with polymer (A) is less likely to increase viscosity.

[0045] The polymerization method for polyoxyalkylene polymers is not particularly limited and includes, for example, polymerization using an alkaline catalyst such as KOH, polymerization using a transition metal compound-porphyrin complex catalyst such as a complex obtained by reacting an organoaluminum compound with porphyrin as shown in Japanese Patent Publication No. 61-215623, polymerization using a complex metal cyanide catalyst as shown in Japanese Patent Publication Nos. 46-27250, 59-15336, U.S. Patent Nos. 3278457, 3278458, 3278459, 3427256, 3427334, and 3427335, polymerization using a catalyst consisting of a polyphosphazene salt as shown in Japanese Patent Publication No. 10-273512, and polymerization using a catalyst consisting of a phosphazene compound as shown in Japanese Patent Publication No. 11-060722.

[0046] To illustrate with an example, first, an epoxy compound is polymerized with an initiator containing hydroxyl groups to obtain a hydroxyl-terminated polymer. After reacting the hydroxyl groups of this polymer with an alkali metal salt (e.g., sodium methoxide), a halogenated hydrocarbon compound containing carbon-carbon unsaturated bonds (e.g., allyl chloride) is reacted to introduce carbon-carbon unsaturated bonds to the polymer ends. Then, by reacting with a hydrosilane compound containing reactive silicon groups (e.g., methyldimethoxysilane, trimethoxysilane), a polyoxyalkylene polymer containing reactive silicon groups can be obtained.

[0047] The mixing ratio of polymer (A) to polymer (B) in the curable composition can be adjusted as appropriate. From the viewpoint of balancing the viscosity of the curable composition and the mechanical properties of the cured product, the mixing ratio of polymer (A) to polymer (B) is preferably 90 / 10 to 10 / 90 by weight, more preferably 80 / 20 to 20 / 80, even more preferably 70 / 30 to 30 / 70, and particularly preferably 60 / 40 to 40 / 60.

[0048] <1-3. Additives> The curable composition may contain various additives in addition to polymers (A) and (B). By including these additives, the physical properties of the curable composition and the cured product can be adjusted. Examples of additives include condensation catalysts, adhesion promoters, plasticizers, fillers, property modifiers, thixotropic agents, photocurable substances, air oxidation curable substances, antioxidants, and light stabilizers. These additives may be used individually or in combination of two or more types.

[0049] (Condensation catalyst) The curable composition can be crosslinked and cured by forming siloxane bonds using a known condensation catalyst. An example of such a condensation catalyst is a tin-based curing catalyst. The amount of tin-based curing catalyst added is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the total amount of polymer (A) and polymer (B).

[0050] Specific examples of tin-based curing catalysts include dialkyltin carboxylates (dibutyltin dilaurate, dibutyltin diacetate, dibutyltin diethylhexanolate, dibutyltin dioctate, dibutyltin dimethyl malate, dibutyltin diethyl malate, dibutyltin dibutyl malate, dibutyltin diisooctyl malate, dibutyltin ditridecyl malate, dibutyltin dibenzyl malate, dibutyltin maleate, dioctyltin diacetate, dioctyltin distearate, dioctyltin dilaurate, dioctyltin diethyl malate, dioctyltin diisooctyl malate, etc.); dialkyltin oxides (dibutyltin oxide, dioctyltin oxide, mixtures of dibutyltin oxide and phthalate esters, etc.); tetravalent tin compounds (dialkyltin oxide, dialkyltin diacetate, etc.) and low molecular weight compounds having alkoxysilyl groups. Examples include reaction products with silicon compounds (such as tetraethoxysilane, methyltriethoxysilane, diphenyldimethoxysilane, and phenyltrimethoxysilane); divalent tin compounds (such as tin octoate, tin naphthenate, and tin stearate); monoalkyltin compounds (such as monobutyltin compounds (monobutyltin trisoctoate, monobutyltin triisopropoxide, etc.) and monooctyltin compounds); reaction products or mixtures of amine compounds and organotin compounds (such as reaction products or mixtures of laurylamine and tin octoate); chelate compounds (such as dibutyltin bisacetylacetonate, dioctyltin bisacetylacetonate, dibutyltin bisethylacetonate, and dioctyltin bisethylacetonate); and tin alkoxides (such as dibutyltin nitride, dibutyltin diethylate, dioctyltin nitride, and dioctyltin diethylate).

[0051] (Adhesion-enhancing agent) When a curable composition is used as a sealant, there is a risk of delamination from the substrate, such as siding boards, due to changes in joint width caused by external forces. Adding an adhesion promoter can reduce the risk of such delamination. Furthermore, using an adhesion promoter may eliminate the need to use a primer to improve adhesion. In this case, simplification of the construction work can be expected. The amount of adhesion promoter to be added is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the total amount of polymer (A) and polymer (B).

[0052] Examples of adhesion-improving agents include silane coupling agents.Specific examples of silane coupling agents include isocyanate group-containing silanes (γ-isocyanatetopropyltrimethoxysilane, γ-isocyanatetopropyltriethoxysilane, γ-isocyanatetopropylmethyldiethoxysilane, γ-isocyanatetopropylmethyldimethoxysilane, etc.); amino group-containing silanes (γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-(β-aminoethyl)-γ-aminopropyltri Methoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldiethoxysilane, γ-ureidopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-benzyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, etc.); mercapto group-containing silanes (γ-mercaptopropyltrimethoxysilane, γ- Mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, etc.); Epoxy group-containing silanes (γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, etc.); Carboxysilanes (β-carboxyethyltriethoxysilane, β-carboxyethyltriethoxysilane, etc.) Examples include: carboxyethylphenylbis(2-methoxyethoxy)silane, N-(β-carboxymethyl)aminoethyl-γ-aminopropyltrimethoxysilane, etc.; vinyl-type unsaturated group-containing silanes (vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-acroyloxypropylmethyltriethoxysilane, etc.); halogen-containing silanes (γ-chloropropyltrimethoxysilane, etc.); and isocyanurate silanes (tris(trimethoxysilyl)isocyanurate, etc.).Furthermore, derivatives obtained by modifying silane coupling agents, such as amino-modified silyl polymers, silylated amino polymers, unsaturated aminosilane complexes, phenylamino long-chain alkylsilanes, aminosilylated silicones, and silylated polyesters, can also be used as silane coupling agents.

[0053] (Plasticizer) When a plasticizer is used in combination with a filler described later, the elongation of the cured product increases, and a larger amount of filler can be mixed in. The amount of plasticizer to be added is preferably 5 to 800 parts by weight, more preferably 10 to 600 parts by weight, and even more preferably 10 to 500 parts by weight, per 100 parts by weight of the total amount of polymer (A) and polymer (B).

[0054] Examples of plasticizers include phthalates (dibutyl phthalate, diheptyl phthalate, di(2-ethylhexyl) phthalate, diisodecyl phthalate, butyl benzyl phthalate, etc.); non-aromatic dibasic acid esters (dioctyl adipate, dioctyl sebacate, dibutyl sebacate, isodecyl succinate, etc.); aliphatic esters (butyl oleate, methyl acetylricinoleate, etc.); polyalkylene glycol esters (diethylene glycol dibenzoate, triethylene glycol dibenzoate, pentaerythritol ester, etc.); phosphate esters (tricresyl phosphate, tributyl phosphate, etc.); trimellitic acid esters; polystyrenes (polystyrene, poly-α-methylstyrene, etc.); polybutadiene; polybutene; polyisobutylene; butadiene-acrylonitrile; polychloroprene; chlorinated paraffins; hydrocarbon oils ( Examples include alkyldiphenyls, partially hydrogenated terphenyls, etc.; process oils; polyethers (polyether polyols (polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc.), and derivatives obtained by converting the hydroxyl groups of polyether polyols to ester groups, ether groups, etc.); epoxy plasticizers (epoxidized unsaturated oils and fats, epoxidized unsaturated fatty acid esters, alicyclic epoxy compounds, epichlorohydrin derivatives, and mixtures thereof); polyester plasticizers obtained from dibasic acids and dihydric alcohols (polyesters obtained from sebaciic acid, adipic acid, azelaic acid, phthalic acid, etc., and ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, etc.); and vinyl polymers (obtained by polymerizing vinyl monomers such as acrylic plasticizers in various ways).

[0055] (filling material) Examples of fillers include wood flour; reinforcing fillers (pulp, cotton chips, asbestos, mica, walnut shell powder, rice husk powder, graphite, white clay, silica (fumed silica, settling silica, crystalline silica, fused silica, dolomite, anhydrous silicic acid, hydrated silicic acid, etc.), carbon black, etc.); fillers (heavy calcium carbonate, colloidal calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium dioxide, bentonite, organic bentonite, ferric oxide, red iron oxide, aluminum powder, flint powder, zinc oxide, activated zinc oxide, zinc powder, zinc carbonate, shirasu balloons, etc.); and fibrous fillers (asbestos, glass fibers and glass filaments, carbon fibers, Kevlar fibers, polyethylene fibers, etc.).

[0056] The amount of filler added is preferably 5 to 5000 parts by weight, more preferably 10 to 2500 parts by weight, and particularly preferably 15 to 1500 parts by weight, based on 100 parts by weight of the total amount of polymer (A) and polymer (B).

[0057] (Property modifier) By using a property modifier, the tensile properties of the cured product can be adjusted. For example, the hardness of the cured product can be increased, or conversely, its hardness can be decreased to increase its elongation. The amount of property modifier added is preferably 0.1 to 80 parts by weight, and more preferably 0.1 to 50 parts by weight, per 100 parts by weight of the total amount of polymer (A) and polymer (B).

[0058] Examples of property modifiers include alkylalkoxysilanes (methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, n-propyltrimethoxysilane, etc.); alkylisopropenoxysilanes (dimethyldiisopropenoxysilane, methyltriisopropenoxysilane, γ-glycidoxypropylmethyldiisopropenoxysilane, etc.); alkoxysilanes with functional groups (γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyldimethylmethoxysilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, etc.); silicone varnishes; and polysiloxanes.

[0059] (Thixotropic agent (dripping prevention agent)) Thixotropic agents (anti-sagging agents) can prevent the curable composition from sagging and improve workability. The amount of thixotropic agent added is preferably 0.1 to 50 parts by weight, and more preferably 0.2 to 25 parts by weight, per 100 parts by weight of the total amount of polymer (A) and polymer (B).

[0060] Examples of thixotropic agents include polyamide waxes; hydrogenated castor oil derivatives; and metal soaps (such as calcium stearate, aluminum stearate, and barium stearate).

[0061] (light curing substance) Photocurable materials are substances that undergo a chemical change and physical changes (such as hardening) in a short time when exposed to light. By including photocurable materials, the tackiness (residual tack) of the cured surface can be reduced. Typical photocurable materials can be cured by leaving them undisturbed at room temperature for one day in a sunny location indoors (such as near a window). The amount of photocurable material to be added is preferably 0.01 to 30 parts by weight per 100 parts by weight of the total amount of polymer (A) and polymer (B).

[0062] Many types of photocurable materials are known, including organic monomers, oligomers, resins, and compositions containing these, and their types are not particularly limited. Examples of photocurable materials include unsaturated acrylic compounds, polyvinyl polycinnamates, and azidized resins.

[0063] (Air-oxidized and hardening substance) An air-oxidation-curable substance refers to a compound having unsaturated groups that can be crosslinked and cured by oxygen in the air. By including an air-oxidation-curable substance, the stickiness (residual tack) of the cured surface can be reduced. A typical air-oxidation-curable substance can be cured, for example, by leaving it undisturbed in the air at room temperature for one day. The amount of air-oxidation-curable substance to be added is preferably 0.01 to 30 parts by weight per 100 parts by weight of the total amount of polymer (A) and polymer (B).

[0064] Examples of air-oxidation curable substances include drying oils (tung oil, linseed oil, etc.); various alkyd resins obtained by modifying drying oils; substances obtained by modifying acrylic polymers, epoxy resins, silicone resins, etc. with drying oils; 1,2-polybutadiene; 1,4-polybutadiene; polymers or copolymers of C5-C8 dienes; and various modified products of polymers or copolymers of C5-C8 dienes (malein-modified products, boiled oil-modified products, etc.).

[0065] (Antioxidants and light stabilizers) Various antioxidants and light stabilizers are known. For example, substances described in [Kenichi Saruwatari et al., "Antioxidant Handbook," Taiseisha, 1976] and [Zenjiro Osawa (ed.), "Degradation and Stabilization of Polymer Materials," CMC, 1990, pp. 235-242] are listed. The amount of antioxidant and / or light stabilizer to be added is preferably 0.1 to 20 parts by weight each, per 100 parts by weight of the total amount of polymer (A) and polymer (B).

[0066] Examples of antioxidants include hindered phenol antioxidants, thioether antioxidants, and phosphorus antioxidants. Specific examples of hindered phenol antioxidants include 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, mono(or di or tri)(α-methylbenzyl)phenol, 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 2,2'-methylenebis(4-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), and 2,5-di-t-butyl Hydroquinone, 2,5-di-t-amyl hydroquinone, triethylene glycol-bis-[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] [Pionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxyhydrocinnamamide), 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzyl Zen, bis(3,5-di-t-butyl-4-hydroxybenzylphosphonate ethyl)calcium, tris-(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 2,4-bis[(octylthio)methyl]o-cresol, N,N'-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl]hydrazine, tris(2,4-di-t-butylphenyl)phosphite, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2'-hydroxy-5'-t-octylphenyl)-benzotriazole Examples include azole, methyl-3-[3-t-butyl-5-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate-polyethylene glycol (molecular weight approximately 300) condensate, hydroxyphenylbenzotriazole derivatives, 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonate bis(1,2,2,6,6-pentamethyl-4-piperidyl), and 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate.

[0067] Examples of light stabilizers include hindered amine compounds, benzotriazole compounds, triazine compounds, benzophenone compounds, and benzoate compounds. Specific examples of hindered amine compounds include dimethyl-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate succinate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}], N,N'-bis(3-aminopropyl)ethylenediamine-2,4-bis[N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino]-6-chloro-1,3,5-triazine condensate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, and bis(2,2,6,6-tetramethyl-4-piperidinyl) succinate ester.

[0068] [2. Form of curable composition] The curable composition may be a one-component type or a two-component type. A one-component curable composition is prepared by pre-mixing all the components and then sealing and storing it. A one-component curable composition hardens after use due to moisture in the air. On the other hand, in a two-component curable composition, a main component containing polymer (A) and polymer (B) and a curing agent containing components such as a curing catalyst, filler, plasticizer, and water are prepared separately. A two-component curable composition is used by mixing the main component and the curing agent. A two-component curable composition may also contain agents other than the main component and curing agent (such as colorants and retarders).

[0069] [3. Uses of curable compositions] One embodiment of the present invention also includes a cured product obtained by curing the above-described curable composition. The uses of the curable composition and its cured product are not particularly limited. For example, a sealant or adhesive containing the above-described curable composition or cured product is also included in one embodiment of the present invention. More specific applications include sealing materials for construction and industrial use (including highly durable elastic sealing materials used in working joints, as well as sealing materials for siding boards, double-glazed windows, and vehicles), electrical and electronic component materials (such as back-sealing agents for solar cells), electrical insulation materials (such as insulating coatings for wires and cables), adhesives, elastic adhesives, contact adhesives, tile adhesives, reactive hot-melt adhesives, paints, powder coatings, coating materials, foams, sealing materials for can lids, electrical and electronic potting agents, films, gaskets, casting materials, various molding materials, artificial marble, sealing materials for rust prevention and waterproofing of cut edges of wired or laminated glass, vibration isolation, vibration damping, sound insulation, and seismic isolation materials (used in automobiles, ships, home appliances, etc.), liquid sealants (used in automobile parts, electrical components, various machine parts, etc.), and waterproofing agents.

[0070] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0071] One embodiment of the present invention may include the following configuration: <1> A curable composition comprising a (meth)acrylic copolymer (A) having reactive silicon groups and a polyoxyalkylene polymer (B) having reactive silicon groups, wherein the proportion of molecules with a number average molecular weight of 100,000 or more in the (meth)acrylic copolymer (A) is 7% by weight or less, and the number average molecular weight of the polyoxyalkylene polymer (B) is 15,000 or more. <2> The (meth)acrylic copolymer (A) comprises a structural unit derived from a highly polar monomer and a structural unit derived from a low-polarity monomer, wherein the highly polar monomer is a (meth)acrylic acid ester monomer having an alkyl group or alkoxyalkyl group having 1 to 3 carbon atoms, and the low-polarity monomer is a (meth)acrylic acid ester monomer having an alkyl group having 8 to 20 carbon atoms. <1> The curable composition described above. <3> The (meth)acrylic copolymer (A) contains 5% to 30% by weight of constituent units derived from the high-polarity monomer and 15% to 38% by weight of constituent units derived from the low-polarity monomer. <2> The curable composition described above. <4> In the (meth)acrylic copolymer (A), the molar ratio of constituent units derived from high-polarity monomers to constituent units derived from low-polarity monomers is 3.0 or less. <2> or <3> The curable composition described above. <5> The aforementioned highly polar monomer is one or more selected from the group consisting of methyl methacrylate, methyl acrylate, ethyl acrylate, and 2-methoxyethyl acrylate. <2> ~ <4> A curable composition as described in any one of the following. <6> The low-polarity monomer is one or more selected from the group consisting of 2-ethylhexyl acrylate, n-octyl acrylate, dodecyl acrylate, and octadecyl acrylate. <2> ~ <5> A curable composition as described in any one of the following. <7> The (meth)acrylic copolymer (A) has 0.5 or more reactive silicon groups represented by the following formula (1) per molecule. <1> ~ <6> A curable composition as described in any one of the following. -Si(R 3 ) 3-a (X) a (1) (wherein each R 3 independently represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and R 3 may be substituted with a heteroatom-containing group. Each X independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2 or 3.) <8> The curable composition according to any one of <1> to <7>, wherein the (meth)acrylic copolymer (A) comprises a (meth)acrylic random copolymer (Aa) containing a structural unit derived from a (meth)acrylate monomer having a reactive silicon group and a structural unit derived from a (meth)acrylate monomer having no reactive silicon group, and the molecular weight distribution of the (meth)acrylic random copolymer (Aa) is 2.0 or more. <9> The curable composition according to any one of <1> to <8>, wherein the polyoxyalkylene polymer (B) has a reactive silicon group represented by the following formula (1). -Si(R 3 ) 3-a (X) a (1) (wherein each R 3 independently represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and R 3 may be substituted with a heteroatom-containing group. Each X independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2 or 3.) <10> A cured product obtained by curing the curable composition according to any one of <1> to <9>. <11> A sealing material or an adhesive comprising the curable composition according to any one of <1> to <9>. EXAMPLES

[0072] Specific examples of the present invention are shown below, but the present invention is not limited to the following examples.

[0073] [Evaluation Method] <Number average molecular weight, weight average molecular weight, molecular weight distribution> In the following examples and comparative examples, the "number-average molecular weight," "weight-average molecular weight," and "molecular weight distribution (ratio of weight-average molecular weight to number-average molecular weight)" were calculated using a standard polystyrene-based method with gel permeation chromatography (GPC). A polystyrene cross-linked gel (TSKguardcolumn SuperHZ-H; manufactured by Tosoh Corporation) was packed as the GPC column, and chloroform was used as the GPC solvent for the measurements.

[0074] Furthermore, the proportion of molecules with a number-average molecular weight of 100,000 or more in polymer (A) was determined from the integrated molecular weight distribution curve obtained during GPC measurement. The integrated molecular weight distribution curve was obtained by detection using a differential refractometer (RI). This proportion will also be referred to as the "proportion of molecules with a molecular weight of 100,000 or more" in the table described later.

[0075] <Evaluation of compatibility> Polymer (A) and polymer (B) were mixed in a 50:50 weight ratio, and then stirred and mixed using a planetary stirring mixer (1600 rpm × 1.5 min + 2200 rpm × 3.0 min). The resulting mixture was left in a 60°C oven for 2 hours, and then its state was observed visually. After that, the mixture was left to stand at room temperature for 1 month, and its state was observed visually. If the mixture was uniform and clear after standing at room temperature for 1 month, it was considered "miscible," and if it was cloudy or phase-separated, it was considered "immiscible."

[0076] <Viscosity Evaluation> The viscosity of the curable composition was measured at 25°C using an E-type viscometer (VISCOMETER TV-25, manufactured by Toki Sangyo Co., Ltd., measuring cone: CORD-4, 13°×R14, rotation speed 1.0 rpm).

[0077] <Evaluation of mechanical properties> A reaction mixture of 2 parts by weight of tin octylate and 0.5 parts by weight of laurylamine was added to 100 parts by weight of the curable composition and thoroughly mixed. The resulting mixture was poured into a mold and degassed under reduced pressure. Then, it was heated and cured at 50°C for 20 hours to obtain a sheet-like cured material with rubber elasticity.

[0078] The obtained sheet-like cured material was punched out into a No. 3 dumbbell shape according to JIS K 6251 to obtain test specimens. Using the obtained test specimens, tensile tests (tensile speed 200 mm / min) were performed at 23°C and 50% relative humidity using an Autograph machine manufactured by Shimadzu Corporation, and the stress at 100% elongation (M100), stress at fracture (Tb), and elongation at fracture (Eb) were measured.

[0079] <Gel fraction> The sheet-like cured material, obtained using the same method as for evaluating mechanical properties, was immersed in toluene for 24 hours, then removed and heat-dried. The gel fraction (%) was calculated from the weight change of the cured material before and after immersion in toluene.

[0080] [Production of (meth)acrylic copolymer (A)] (Manufacturing Example 1) 193.8 g of butyl acetate was placed in a separable flask (1) equipped with a stirrer and reflux condenser, and nitrogen bubbling was performed at room temperature for 30 minutes. 44.4 g of methyl acrylate (MA), 181.8 g of butyl acrylate (BA), 60.3 g of octadecyl methacrylate (SMA), and 13.5 g of 3-(methyldimethoxysilyl)propyl (meth)acrylate (KBM-502, manufactured by Shin-Etsu Chemical Co., Ltd.) were placed in a three-necked flask equipped with a stirrer and mixed by stirring to obtain a homogeneous solution. Subsequently, 6.00 g of 2,2'-azobis(2-methylbutyronitrile) (V-59, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 131.5 g of butyl acetate were placed in the same three-necked flask and mixed by stirring to obtain a homogeneous solution, which was then prepared as dropwise solution (2). Furthermore, 2.50 g of V-59 and 22.20 g of butyl acetate were placed in another two-necked flask, and a homogeneous solution was obtained by stirring to obtain an additional initiator solution (3).

[0081] Polymerization was initiated by adding dropwise solution (2) to a separable flask (1) that had been heated in an oil bath until the internal temperature reached 105°C. The entire volume of dropwise solution (2) was added dropwise over approximately 3 hours. Subsequently, initiator solution (3) was added to the separable flask (1) over approximately 1.0 hour, followed by stirring for approximately 2 hours to obtain the polymer reaction solution. Butyl acetate was removed from the polymer reaction solution under reduced pressure using an evaporator to obtain the target (meth)acrylic copolymer (A-1). The weight-average molecular weight of the (meth)acrylic copolymer (A-1) obtained by GPC was 7,000, and the molecular weight distribution was 2.6.

[0082] <Manufacturing Examples 2-6> Polymerization was carried out in the same manner as in Production Example 1, except that the materials were weighed according to Table 1, to obtain (meth)acrylic copolymers (A-2) to (A-6).

[0083] [Table 1]

[0084] <Manufacturing Example 7> (preparation) (Meth)acrylic acid ester monomers were mixed in the proportions shown in Table 3. Specifically, 707 g of butyl acrylate, 107 g of ethyl acrylate, and 186 g of octadecyl acrylate (total: 1000 g) were mixed. This mixture is referred to as the "(meth)acrylic acid ester monomer mixture."

[0085] (polymerization) The inside of a stainless steel reaction vessel equipped with a stirrer was deoxygenated. 5.8 g of cuprous bromide and 200 g of a (meth)acrylic acid ester monomer mixture were charged into this reaction vessel and heated and stirred. Next, 90 g of acetonitrile and 10.7 g of the initiator (diethyl 2,5-dibromoadipate) were added and mixed. After adjusting the temperature of the mixture to approximately 65°C, pentamethyldiethylenetriamine was added to start the polymerization reaction. Subsequently, the remaining 800 g of the (meth)acrylic acid ester monomer mixture was added sequentially to allow the polymerization reaction to proceed. During the polymerization reaction, pentamethyldiethylenetriamine was added as needed to adjust the polymerization rate. The total amount of pentamethyldiethylenetriamine used throughout the polymerization reaction was 1.7 g. As polymerization progressed, the temperature of the reaction system tended to rise due to the heat of reaction, but the temperature of the reaction system was adjusted to approximately 80-90°C. When the monomer conversion rate (polymerization reaction rate) reached 95%, volatile components were removed by vacuum defloration to obtain a polymer concentrate. The time required up to this stage was 4 hours.

[0086] To the obtained polymer concentrate, 200 g of 1,7-octadiene, 360 g of acetonitrile, and 3.1 g of pentamethyldiethylenetriamine were added. Next, the reaction system was heated and stirred for several hours while adjusting the temperature to approximately 70-90°C to allow the 1,7-octadiene to react with the polymer's terminals.

[0087] (purification) At the end of the reaction, an oxygen-nitrogen mixed gas was introduced into the gas phase of the reaction vessel. Next, the reaction solution was heated and stirred for several hours while maintaining the reaction system temperature at approximately 70-90°C, thereby bringing the polymerization catalyst contained in the reaction solution into contact with oxygen. Then, acetonitrile and unreacted 1,7-octadiene were removed by defoliation under reduced pressure to obtain a polymer concentrate.

[0088] After diluting the polymer concentrate with 1000g of butyl acetate, 10g of a filtration aid (radiolite #800: manufactured by Showa Chemical Industry Co., Ltd.) was added and the mixture was stirred, and the insoluble catalyst components were filtered out.

[0089] The filtrate was placed in a stainless steel reaction vessel equipped with a stirrer, and 5 g each of adsorbents (Kyoward 700SEN-S and Kyoward 500SH) were added. Next, an oxygen-nitrogen mixed gas was introduced into the gas phase of the reaction vessel, and the mixture was heated and stirred at approximately 100°C for 30 minutes. Then, insoluble components (such as adsorbents) were filtered off to obtain a clear filtrate. After repeating this operation once, the filtrate was concentrated to obtain a crude polymer product.

[0090] To the crude polymer product, 1.5 g of a heat stabilizer (Sumilyzer GS: manufactured by Sumitomo Chemical Co., Ltd.) and 5 g each of adsorbents (Kyoward 700SEN-S and Kyoward 500SH) were added. The system was heated, and the crude polymer product was purified by adsorption under reduced pressure at a high temperature of approximately 180-200°C for 2-4 hours. Next, 5 g and 20 g of the adsorbents (Kyoward 700SEN and Kyoward 500SH) were added, respectively. Then, the gas phase in the reaction vessel was changed to an oxygen-nitrogen mixed gas atmosphere, and adsorption purification was continued by heating and stirring at a high temperature of approximately 180-200°C for 2-6 hours. Next, the polymer was diluted with 1000 g of butyl acetate, and the adsorbents were removed by filtration. The filtrate was concentrated to obtain a polymer having alkenyl groups at both ends. The number of alkenyl groups introduced into the polymer was 2.0 per molecule on average.

[0091] (Introduction of alkoxysilyl groups) To the obtained polymer, 20 g of methyldimethoxysilane (DMS), 3 g of methyl orthoformate, and 0.13 g of an isopropanol solution (3.0 wt%) of a bis(1,3-divinyl-1,1,3,3-tetramethyldisiloxane) platinum complex catalyst were mixed and heated and stirred at approximately 100°C. After about 1 hour, volatile components (unreacted DMS, etc.) were removed by distillation under reduced pressure to obtain (meth)acrylic copolymer (A-7). The number of alkoxysilyl groups introduced into (meth)acrylic copolymer (A-7) was an average of 2.0 per molecule.

[0092] [Table 2]

[0093] [Table 3]

[0094] [Production of polyoxyalkylene polymer (B)] <Manufacturing Example 9> Using polyoxypropylene glycol with a number-average molecular weight of approximately 4,500 as an initiator, polymerization of propylene oxide was carried out with a zinc hexacyanocobaltate grime complex catalyst to obtain polyoxypropylene (Q-1) with a number-average molecular weight of 27,900 (end-group equivalent molecular weight of 17,700) and a molecular weight distribution Mw / Mn = 1.21, with hydroxyl groups at both ends.

[0095] To the hydroxyl groups of the obtained polyoxypropylene (Q-1), 1.2 molar equivalents of sodium methoxide were added as a 28% methanol solution. After removing the methanol by vacuum defoliation, an additional 1.5 molar equivalents of allyl chloride were added to the hydroxyl groups of polyoxypropylene (Q-1) to convert the terminal hydroxyl groups to allyl groups. Unreacted allyl chloride was removed by vacuum defoliation.

[0096] The obtained unpurified polyoxypropylene was mixed and stirred with n-hexane and water, and the water was removed by centrifugation. The metal salts in the polymer were removed from the resulting hexane solution by defloration of hexane under reduced pressure. Thus, polyoxypropylene (R-1) having allyl groups at the terminals was obtained.

[0097] To 500 g of polyoxypropylene (R-1), 50 μL of platinum divinyldisiloxane complex solution (3% by weight isopropanol solution in terms of platinum) was added, and 4.8 g of dimethoxymethylsilane was slowly added dropwise while stirring. The resulting mixed solution was reacted at 100°C for 2 hours, and then the unreacted dimethoxymethylsilane was removed under reduced pressure to obtain polyoxypropylene (B-1) with a number-average molecular weight of approximately 28,500, having dimethoxymethylsilyl groups at its termini. It was found that polyoxypropylene (B-1) has an average of 0.8 dimethoxymethylsilyl groups at each termini and an average of 1.6 dimethoxymethylsilyl groups per molecule.

[0098] <Manufacturing Example 10> Using polyoxypropylene glycol with a number-average molecular weight of approximately 4,500 as an initiator, polymerization of propylene oxide was carried out with a zinc hexacyanocobaltate grime complex catalyst to obtain polyoxypropylene (Q-2) with a number-average molecular weight of 27,900 (end-group equivalent molecular weight of 17,700) and a molecular weight distribution Mw / Mn = 1.21, with hydroxyl groups at both ends.

[0099] To the hydroxyl groups of the obtained polyoxypropylene (Q-2), 1.0 molar equivalent of sodium methoxide was added as a 28% methanol solution. After removing methanol by vacuum defoliation, 1.0 molar equivalent of allyl glycidyl ether was added to the hydroxyl groups of polyoxypropylene (Q-2) and the reaction was carried out at 130°C for 2 hours. Subsequently, methanol was removed by adding 0.3 molar equivalents of a methanol solution of sodium methoxide, and then 1.8 molar equivalents of allyl chloride were added to convert the terminal hydroxyl groups to allyl groups.

[0100] The obtained unpurified polyoxypropylene was mixed and stirred with n-hexane and water, then the water was removed by centrifugation. The metal salts in the polymer were removed by defloration of the hexane from the resulting hexane solution under reduced pressure. This yielded polyoxypropylene (R-2) having multiple carbon-carbon unsaturated bonds at its ends. It was found that polyoxypropylene (R-2) had an average of 2.0 carbon-carbon unsaturated bonds introduced at each end.

[0101] To 500 g of the obtained polyoxypropylene (R-2), 50 μL of platinum divinyldisiloxane complex solution (3% by weight isopropanol solution in terms of platinum) was added, and 8.0 g of dimethoxymethylsilane was slowly added dropwise while stirring. After reacting the resulting mixed solution at 100°C for 2 hours, the unreacted dimethoxymethylsilane was removed by distillation under reduced pressure to obtain polyoxypropylene (B-2) with a number-average molecular weight of 28,800 and multiple dimethoxymethylsilyl groups at its termini. It was found that polyoxypropylene (B-2) has an average of 1.7 dimethoxymethylsilyl groups at each termini and an average of 3.4 dimethoxymethylsilyl groups per molecule.

[0102] <Manufacturing Example 11> Using polyoxypropylene glycol with a number-average molecular weight of approximately 4,500 as an initiator, polymerization of propylene oxide was carried out with a zinc hexacyanocobaltate grime complex catalyst to obtain polyoxypropylene (Q-3) with a number-average molecular weight of 14,300 (end-group equivalent molecular weight of 9,100) and a molecular weight distribution Mw / Mn = 1.21, with hydroxyl groups at both ends.

[0103] To the hydroxyl groups of the obtained polyoxypropylene (Q-3), 1.2 molar equivalents of sodium methoxide were added as a 28% methanol solution. After removing the methanol by vacuum defoliation, an additional 1.5 molar equivalents of allyl chloride were added to the hydroxyl groups of polyoxypropylene (Q-3) to convert the terminal hydroxyl groups to allyl groups. Unreacted allyl chloride was removed by vacuum defoliation.

[0104] The obtained unpurified polyoxypropylene was mixed and stirred with n-hexane and water, and the water was removed by centrifugation. The metal salts in the polymer were removed by defloration of the hexane from the obtained hexane solution under reduced pressure. Thus, polyoxypropylene (R-3) having allyl groups at the terminals was obtained.

[0105] To 500 g of polyoxypropylene (R-3), 50 μL of platinum divinyldisiloxane complex solution (3% by weight of isopropanol solution in terms of platinum) was added, and 8.4 g of dimethoxymethylsilane was slowly added dropwise while stirring. The resulting mixed solution was reacted at 100°C for 2 hours, and then the unreacted dimethoxymethylsilane was removed under reduced pressure to obtain polyoxypropylene (B-3) with a number-average molecular weight of 14,600 and dimethoxymethylsilyl groups at the ends. It was found that polyoxypropylene (B-3) has an average of 0.8 dimethoxymethylsilyl groups at each end and an average of 1.5 dimethoxymethylsilyl groups per molecule.

[0106] [Evaluation of compatibility] As shown in Table 4, the compatibility of each polymer (A) and polymer (B) combination was evaluated. The evaluation results are shown in Table 4.

[0107] [Table 4]

[0108] As shown in Table 4, polymers (A-5) or (A-6) with a number-average molecular weight of 100,000 or more exceeding 7% by weight were incompatible when combined with high molecular weight polymers (B-1) or (B-2).

[0109] [Examples 1-8, Comparative Examples 1-5] A curable composition was prepared by mixing polymer (A) and polymer (B) according to the weight ratios shown in Table 5. The compositions and evaluation results of Examples 1-8 and Comparative Examples 1-5 are shown in Table 5.

[0110] [Table 5]

[0111] As shown in Table 5, Examples 1 to 8 each contain one of the polymers (A-1) to (A-4) in which the proportion of molecules with a number average molecular weight of 100,000 or more is 7% by weight or less, and either polymer (B-1) or polymer (B-2) in which the number average molecular weight is 15,000 or more. Examples 1 to 8 all exhibited lower viscosity compared to both the viscosity of polymer (A) alone and the viscosity of polymer (B) alone.

[0112] On the other hand, Comparative Example 1 includes polymer (A-7) in which the proportion of molecules with a number average molecular weight of 100,000 or more exceeds 7% by weight, and polymer (B-1). Comparative Example 1 showed a higher viscosity compared to polymer (B-1) alone. Furthermore, Comparative Examples 2 to 5 include any of polymers (A-1) to (A-4) and polymer (B-3) with a number average molecular weight of less than 15,000. Comparative Examples 2 to 5 showed a higher viscosity compared to polymer (B-3) alone.

[0113] Furthermore, the mechanical properties of the cured products were evaluated for Examples 1, 3, 5, and 7, and Comparative Example 1. The evaluation results are shown in Table 6.

[0114] [Table 6]

[0115] As described above, Examples 1, 3, 5, and 7 each contain one of the polymers (A-1) to (A-4) in which the proportion of molecules with a number average molecular weight of 100,000 or more is 7% by weight or less, whereas Comparative Example 1 contains a polymer (A-7) in which the proportion of molecules with a number average molecular weight of 100,000 or more is greater than 7% by weight. The cured products of Examples 1 to 4 all showed greater stress at break (Tb) and elongation at break (Eb) compared to the cured product of Comparative Example 1, and exhibited superior mechanical properties. [Industrial applicability]

[0116] One aspect of the present invention can be used in curable compositions where suppressed viscosity and excellent mechanical properties of the cured product are required.

Claims

1. A curable composition comprising a (meth)acrylic copolymer (A) having reactive silicon groups and a polyoxyalkylene polymer (B) having reactive silicon groups, In the (meth)acrylic copolymer (A), the proportion of molecules with a number average molecular weight of 100,000 or more is 7.0% by weight or less. A curable composition wherein the number average molecular weight of the polyoxyalkylene polymer (B) is 15,000 or more.

2. The (meth)acrylic copolymer (A) comprises structural units derived from high-polarity monomers and structural units derived from low-polarity monomers. The aforementioned highly polar monomer is a (meth)acrylic acid ester monomer having an alkyl group or alkoxyalkyl group having 1 to 3 carbon atoms. The curable composition according to claim 1, wherein the low-polarity monomer is a (meth)acrylic acid ester monomer having an alkyl group having 8 to 20 carbon atoms.

3. The curable composition according to claim 2, wherein the (meth)acrylic copolymer (A) contains 5% to 30% by weight of structural units derived from the high-polarity monomer and 15% to 38% by weight of structural units derived from the low-polarity monomer.

4. The curable composition according to claim 2, wherein the molar ratio of constituent units derived from a highly polar monomer to constituent units derived from a low polar monomer in the (meth)acrylic copolymer (A) is 3.0 or less.

5. The curable composition according to claim 2, wherein the highly polar monomer is one or more selected from the group consisting of methyl methacrylate, methyl acrylate, ethyl acrylate, and 2-methoxyethyl acrylate.

6. The curable composition according to claim 2, wherein the low-polarity monomer is one or more selected from the group consisting of 2-ethylhexyl acrylate, n-octyl acrylate, dodecyl acrylate, and octadecyl acrylate.

7. The curable composition according to claim 1, wherein the (meth)acrylic copolymer (A) has 0.5 or more reactive silicon groups represented by the following formula (1) per molecule. -Si(R ３ ) ３－ａ (X) ａ (1) (In the formula, R ３ Each of these independently represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and R ３ (The group may be substituted with a heteroatom-containing group. Each X independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3.)

8. The (meth)acrylic copolymer (A) includes a (meth)acrylic random copolymer (Aa) containing a constituent unit derived from a (meth)acrylic acid ester monomer having a reactive silicon group and a constituent unit derived from a (meth)acrylic acid ester monomer not having a reactive silicon group. The curable composition according to claim 1, wherein the molecular weight distribution of the (meth)acrylic random copolymer (Aa) is 2.0 or greater.

9. The curable composition according to claim 1, wherein the polyoxyalkylene polymer (B) has a reactive silicon group represented by the following formula (1). -Si(R ３ ) ３－ａ (X) ａ (1) (wherein R ３ each independently represent a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and R ３ may be substituted with a heteroatom-containing group. Each X independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2 or 3.)

10. A cured product obtained by curing a curable composition according to any one of claims 1 to 9.

11. A sealant or adhesive comprising the curable composition according to any one of claims 1 to 9.

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