Hardening components

Abstract

The present invention relates to a curable composition which comprises (A) a polyoxyalkylene-based polymer having a silicon-containing reactive group, (B) a (meth)acrylic-ester-based polymer having a trialkoxysilyl group, and (C) a specific silane compound having a guanidine group. Because a nonorganotin catalyst is used for this curable composition, the curable composition has excellent compatibility among the components, tends less to come to have defects due to catalyst transition, is excellent in terms of curability and adhesiveness, and gives cured objects having excellent mechanical performance.

Description

[Technical Field]

[0001] The present invention relates to a curable composition, and more particularly to a curable composition comprising a polyoxyalkylene polymer having a silicon-containing reactive group, a (meth)acrylic acid ester polymer having a trialkoxysilyl group, and a silane compound having a guanidine group. [Background technology]

[0002] Organic polymers having at least one silicon-containing reactive group per molecule are known to undergo a curing reaction with moisture (water in the air) even at room temperature, yielding rubber-like cured products with excellent mechanical properties. Such polymers have already been disclosed in the literature (Patent Documents 1-4) and are widely used in industrial production, sealing materials, adhesives, paints, and other applications. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 52-73998A [Patent Document 2] Japanese Patent Publication No. 11-130931A [Patent Document 3] WO2016 / 002907A [Patent Document 4] WO2015 / 158864A [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Curable compositions containing the above-mentioned silicon-containing reactive groups of organic polymers typically use organotin compounds as curing catalysts. However, depending on the application, their use may be restricted by the laws of the EU (European Union) and other countries. Therefore, it is sometimes necessary to reduce or eliminate the use of organotin compounds as much as possible. However, problems can arise even when non-organotin compounds are used as curing catalysts. For example, when organotitanic acid esters, organozirconate esters, organoaluminate esters, etc. are used as alternative metal catalysts, they often exhibit low catalytic activity in silanol condensation, and gelation problems may also occur. Furthermore, while carboxylic acids, amine compounds, and amidine compounds are expected to have little environmental impact because they do not contain metals, many catalysts, such as 1,8-diazabicyclo[5.4.0]undeca-7-ene (DBU), have low compatibility within the composition. Therefore, such catalysts tend to undergo transitions, which can easily lead to separation, leaching, or contamination of the substrate. Patent Document 4 discloses that compatibility issues can be improved by using a silane having an amidine group or a guanidine group as a catalyst.

[0005] The inventors have found through research that the catalytic activity of catalysts varies greatly depending on the type of organic polymer having silicon-containing reactive groups. In the case of sealants or adhesives containing polymers having silicon-containing reactive groups, the above-mentioned prior art still has room for improvement in terms of improving the curability and adhesion of curable compositions, reducing the transition of non-organotin catalysts, and ensuring the mechanical strength of cured products.

[0006] The main object of the present invention is to provide a curable composition using a non-organotin catalyst that has excellent curability and adhesion and can ensure the mechanical performance of the cured product. The non-organotin catalyst has good compatibility within the curable composition and a low tendency to cause precipitation defects due to transitions.

[0007] Another object of the present invention is to provide a cured product based on the above-mentioned curable composition.

[0008] Another object of the present invention is to provide an adhesive based on the above curable composition.

[0009] Another object of the present invention is to provide a sealing material based on the above curable composition.

Means for Solving the Problems

[0010] The present invention includes the following technical solutions.

[0011] [1] A curable composition comprising: (A) a polyoxyalkylene polymer having a silicon-containing reactive group, (B) a (meth)acrylate polymer having a trialkoxysilyl group, and (C) a catalyst represented by the general formula (1).

[0012]

Chemical formula

[0013] -Si(R 7 ) 3-b X b (2) (In the formula, R 7Each is independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 20 carbon atoms, or a triorganosiloxy group represented by -OSi(R’)3, where each R’ is independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, each X independently represents a hydroxyl group or a hydrolyzable group, and b is an integer of 1 to 3.) [3] The component (A) is the curable composition according to [1] or [2], having an average of 1.1 or more silicon-containing reactive groups per molecule.

[0014] [4] The component (A) is the curable composition according to any one of [1] to [3], having a main chain structure containing polyoxypropylene.

[0015] [5] R 1 ~R 6 Each is independently an alkyl group having 1 to 6 carbon atoms, and is the curable composition according to any one of [1] to [4].

[0016] [6] R 1 ~R 6 Each is independently a methyl group, an ethyl group and / or a propyl group, and m is an integer of 2 to 4, and is the curable composition according to [5].

[0017] [7] The component (C) is one or more selected from tetramethylguanidinepropyltrimethoxysilane, tetramethylguanidinepropylmethyldimethoxysilane, tetramethylguanidinepropyldimethylmethoxysilane and tetramethylguanidinepropyltriethoxysilane, and is the curable composition according to any one of [1] to [5].

[0018] [8] The curable composition further optionally contains as component (D) a (meth)acrylic acid ester polymer having a silicon-containing reactive group other than a trialkoxysilyl group, wherein the content of component (B) is 18% or more of the total mass of components (A), (B), and (D), as described in any of [1] to [7].

[0019] [9] A curable composition according to any one of [1] to [8], characterized in that the content of component (C) is 0.1 to 10 parts by weight per 100 parts by weight of the total mass of component (A) and component (B).

[0020] A cured product obtained by curing any one of the curable compositions described in

[10] , [1], to [9].

[0021] An adhesive comprising a curable composition as described in any one of

[11] [1] to [9].

[0022] A sealing material comprising a curable composition described in any one of

[12] [1] to [9]. [Effects of the Invention]

[0023] The curable composition of the present invention employs a non-organotin catalyst, resulting in excellent compatibility between each component, a low tendency for defects due to catalyst transitions, and superior curability and adhesion. The cured product exhibits excellent mechanical properties. However, the above description does not represent all embodiments and advantages of the present invention. [Modes for carrying out the invention]

[0024] The embodiments of the present invention will be described below, but the present invention is not limited thereto. The present invention is not limited to the configurations described below, and various modifications can be made within the scope of the claims. Furthermore, embodiments or examples that appropriately combine the technical means described in different embodiments or examples are also included within the technical scope of the present invention. In addition, all documents mentioned herein are incorporated herein by reference.

[0025] Furthermore, unless otherwise specified, the technical terms and terms used in this invention have the same implications as those generally understood by those skilled in the art.

[0026] In the present invention, "alkoxy group" refers to an alkyl group bonded to another part of the compound via an oxygen atom.

[0027] In this invention, "(meth)acrylic acid ester" refers to "acrylic acid ester and / or methacrylic acid ester," and "(meth)acrylic acid" refers to "acrylic acid and / or methacrylic acid." Similar expressions also have the same implications.

[0028] Unless otherwise specified, in the present invention, "silyl group" refers to a -SiH3 group obtained from silane, wherein at least one hydrogen atom of the silyl group may be substituted with an organic group (for example, an alkyl group having 1 to 20 carbon atoms and / or a halogen atom). In particular, the silyl group may include a trimethylsilyl group and a triethylsilyl group, etc.

[0029] In the context describing the present invention (particularly in the context of the appended claims), the words “one,” “one kind,” “the,” and similar expressions should be interpreted as intended to be both singular and plural unless otherwise specified or unless there is a clear inconsistency in the context.

[0030] In this specification, a numerical range expressed as "number A to number B" or "number A - number B" includes the upper and lower limit numbers A and B.

[0031] In this specification, "alkyl group having 1 to 20 carbon atoms" refers to an alkyl group having 1 to 20 carbon atoms. Other similar descriptions have the same implications.

[0032] In this specification, the expression "may" includes both cases where some action is taken and cases where no action is taken. In this specification, "optional" or "optionally" means that any event or situation described thereafter may or may not occur, and such description includes cases where the event occurs and cases where it does not occur.

[0033] In this specification, "several specific / preferred embodiments," "other several specific / preferred embodiments," "several specific / preferred technical configurations," "other several specific / preferred technical configurations," etc., means that certain elements (e.g., features, structures, properties, and / or characteristics) related to the embodiment are included in at least one embodiment described herein, and may or may not be included in other embodiments. It should be understood that such elements can be incorporated into various embodiments in any appropriate manner.

[0034] In the specification and claims of the present invention, the expression “includes” and any variation thereof are intended to include the non-exclusive concept of “inclusion.” For example, a process, method or system, product or equipment comprising a series of steps or units is not limited to the listed steps or units, and may optionally include steps or units not listed, or selectively include other steps or units specific to those processes, methods, products or equipment.

[0035] <Curable composition> The curable composition of the present invention comprises component (A), which is a polyoxyalkylene polymer having a silicon-containing reactive group; component (B), which is a (meth)acrylic acid ester polymer having a trialkoxysilyl group; component (C), which is a catalyst represented by general formula (1); and other components of any choice. The above components may be used individually or in combination of two or more. Each component will be described in order below.

[0036] <Ingredient (A)> Component (A) in the present invention is a polyoxyalkylene polymer having silicon-containing reactive groups. Polyoxyalkylene polymers have a relatively low glass transition temperature and high moisture permeability, resulting in relatively good cold resistance and adhesion of the resulting cured product. In the present invention, the main chain skeleton of the polyoxyalkylene polymer is not particularly limited, and examples include polyoxyethylene, polyoxypropylene, polyoxybutylene, polytetrahydrofuran, polyoxyethylene-polyoxypropylene copolymer, polyoxypropylene-polyoxybutylene copolymer, etc. In one specific embodiment of the present invention, component (A) employs a main chain structure including the case of polyoxypropylene.

[0037] (Silicon-containing reactive group) In the present invention, a silicon-containing reactive group means a group having a hydroxyl group or a hydrolyzable group bonded to a silicon atom, which can form a siloxane bond and crosslink through a silanol condensation reaction accelerated by a catalyst. The hydrolyzable group refers to a group that reacts with water to form a hydroxyl group. In some specific embodiments of the present invention, component (A) has one or more silicon-containing reactive groups represented by general formula (2).

[0038] -Si(R 7 ) 3-b X b (2) In the formula, R 7Each of the following is independently a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C7-C20 aralkyl group, or a triorganosiloxy group represented by -OSi(R')3, where R' is independently a substituted or unsubstituted C1-C20 alkyl group, X is independently a hydroxyl group or a hydrolyzable group, and b is an integer from 1 to 3. When substitution is made in the above-mentioned groups, the substituent may include a heteroatom-containing group or a halogen atom. Examples of heteroatom-containing groups include oxygen-containing groups such as methoxy, ethoxy, phenoxy, and furyl groups; nitrogen-containing groups such as N,N-dimethylamino, N-phenylamino, N,N-dimethylaminomethyl, N,N-dimethylaminoethyl, and N,N-diethylaminomethyl groups; and sulfur-containing groups such as chenyl groups. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine.

[0039] The hydrolyzable group is not particularly limited and any conventionally known hydrolyzable group is acceptable. Examples include hydrogen atoms, halogen atoms, alkoxy groups, acyloxy groups, ketoximate groups, amino groups, amide groups, aminooxy groups, mercapto groups, alkenyloxy groups, etc. From the viewpoint of hydrolysis stability and ease of handling, alkoxy groups are more preferred, and methoxy groups and ethoxy groups are particularly preferred.

[0040] The number of hydrolyzable groups or hydroxyl groups bonded to a single silicon atom is between 1 and 3. When two or more hydrolyzable groups or hydroxyl groups are bonded to a silicon-containing reactive group, the bonded groups may be the same or different.

[0041] From the viewpoint of curability, b in the above general formula (2) is preferably 2 or 3.

[0042] In the above general formula (1), R 7Examples include alkyl groups such as methyl and ethyl groups; cycloalkyl groups such as cyclohexyl groups; aryl groups such as phenyl groups; aralkyl groups such as benzyl groups; or triorganosiloxy groups represented by -OSi(R')3 where R' is independently a methyl or phenyl group. Of these, from the viewpoint of raw material utilization, R 7 And it is particularly preferable that R' is a methyl group.

[0043] Examples of silicon-containing reactive groups include trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group, dimethoxymethylsilyl group, diethoxymethylsilyl group, diisopropoxymethylsilyl group, (chloromethyl)dimethoxysilyl group, and (methoxymethyl)dimethoxysilyl group. From the viewpoint of obtaining excellent curability, trimethoxysilyl group, triethoxysilyl group, dimethoxymethylsilyl group, and (methoxymethyl)dimethoxysilyl group are preferred. From the viewpoint of easier production, trimethoxysilyl group and dimethoxymethylsilyl group are more preferred.

[0044] The number of silicon-containing reactive groups in component (A) per molecule is preferably 1.1 or more on average, more preferably 1.1 to 5, and even more preferably 1.3 to 4. If the number of silicon-containing reactive groups in a molecule is less than 1.1, the curing ability may be insufficient, making it difficult to obtain a cured product with excellent rubber elasticity. In the present invention, by appropriately increasing the number of silicon-containing reactive groups in component (A) under certain conditions, it becomes easier to obtain a cured product with excellent tensile strength.

[0045] The silicon-containing reactive group may be present at the ends of the main chain or side chains of the polyoxyalkylene polymer, or at both the ends of the main chain and side chains of the organic polymer. The term "end" includes the chain ends and the structures near them of the polymer molecular chain. Specifically, it is defined as the bonding portion from the end to a number of atoms that represent 20% (preferably 10%) of the total number of bonding atoms among the bonding atoms constituting the polymer molecular chain. When expressed in terms of the number of bonding atoms, the end is defined as the portion from the end of the polymer molecular chain to the 30th atom, preferably the 20th atom. In particular, when the silicon-containing reactive group is present only at the ends of the main chain, the effective network size of the final cured product becomes longer, making it easier to obtain a rubbery cured product that exhibits high elongation and low elastic modulus. In some specific embodiments of the present invention, component (A) is a polyoxylated propylene polymer having trimethoxysilyl groups and / or methyldimethoxysilyl groups at its ends.

[0046] (Method for synthesizing component (A)) In some specific embodiments of the present invention, the polyoxyalkylene polymer is a product obtained by reacting a polymer having hydroxyl groups at its termini with a compound containing a silicon-containing reactive group that reacts with the carbon-carbon unsaturated bond, after introducing carbon-carbon unsaturated bonds to the termini of the polymer.

[0047] As a polymerization method for precursors of polyoxyalkylene polymers, i.e., polymers having hydroxyl groups at their terminals, a method is preferred in which an epoxy compound is polymerized with an initiator having hydroxyl groups using a metal cyanide complex catalyst such as a zinc hexacyanocobaltate glyme complex. Examples of initiators having hydroxyl groups include ethylene glycol, propylene glycol, glycerin, pentaerythritol, low molecular weight polypropylene glycol, polyoxypropylene triol, allyl alcohol, polypropylene monoallyl ether, and polypropylene monoalkyl ether, which have one or more hydroxyl groups. Examples of epoxy compounds include alkylene oxides such as ethylene oxide and propylene oxide; and glycidyl ethers such as methyl glycidyl ether and allyl glycidyl ether. Among these, propylene oxide is preferred.

[0048] In some preferred embodiments of the present invention, a method for introducing a carbon-carbon unsaturated bond at the terminal is employed, in which a polymer having a hydroxyl group at the terminal is treated with an alkali metal salt, and then reacted with an epoxy compound having a carbon-carbon unsaturated bond and / or a halogenated hydrocarbon compound having a carbon-carbon unsaturated bond.

[0049] In this invention, by using an alkali metal salt when reacting a polymer having hydroxyl groups at its terminals with an epoxy compound having carbon-carbon unsaturated bonds, the epoxy compound having carbon-carbon unsaturated bonds can be uniformly reacted with all terminal sites of the polymer. Examples of alkali metal salts used in this invention include sodium hydroxide, sodium alkoxide, potassium hydroxide, potassium alkoxide, lithium hydroxide, lithium alkoxide, cesium hydroxide, and cesium alkoxide. From the viewpoint of availability, sodium methoxide is preferred. The alkali metal salt may be used in a dissolved state in a solvent (e.g., methanol, ethanol, etc.). The amount of alkali metal salt added in this invention is preferably such that the molar ratio to the hydroxyl groups of the polymer is 0.6 or more, and more preferably such that the molar ratio is 0.8 or more. If the amount of alkali metal salt added is too small, the reaction may not proceed sufficiently, and if the amount added is too large, the alkali metal salt may remain as an impurity and cause side reactions.

[0050] In the present invention, preferred epoxy compounds having carbon-carbon unsaturated bonds include, from the viewpoint of reaction activity, allyl glycidyl ether, methacrylate glycidyl acrylate, glycidyl methacrylate, butadiene monooxide, and 1,4-cyclopentadiene monoepoxide, with allyl glycidyl ether being particularly preferred. The amount of epoxy compound having carbon-carbon unsaturated bonds added may be any amount considering the amount of carbon-carbon unsaturated bonds introduced to the polymer and its reactivity. In particular, the molar ratio to the hydroxyl groups contained in the polymer is preferably 0.2 or higher, more preferably 0.5 or higher. Furthermore, the molar ratio is preferably 5.0 or lower, and more preferably 2.0 or lower. Examples of halogenated hydrocarbon compounds having carbon-carbon unsaturated bonds used in the present invention include vinyl chloride, allyl chloride, methyl chloride, vinyl bromide, allyl bromide, methyl bromide, vinyl iodide, allyl iodide, and methyl iodide, but from the viewpoint of ease of handling, allyl chloride and methyl chloride are more preferred. The amount of halogenated hydrocarbon compound having carbon-carbon unsaturated bonds added is not particularly limited, but the molar ratio of the halogenated hydrocarbon compound to the hydroxyl groups contained in the polyoxyalkylene polymer is preferably 0.7 or higher at the lower limit, more preferably 1.0 or higher, and preferably 5.0 or lower at the upper limit, and more preferably 2.0 or lower.

[0051] The introduction of silicon-containing reactive groups can be carried out using known methods. For example, the following introduction methods can be cited.

[0052] (I) A method for adding a hydrosilane compound to a polymer having carbon-carbon unsaturated bonds by a hydrosilylation reaction.

[0053] (II) A method for reacting a polymer having carbon-carbon unsaturated bonds with a compound (also called a silane coupling agent) that simultaneously has a group capable of reacting with carbon-carbon unsaturated bonds to form a bond, and a silicon-containing reactive group. Examples of silane coupling agents capable of reacting with carbon-carbon unsaturated bonds to form a bond include, but are not limited to, mercapto groups.

[0054] (III) A method for reacting an organic polymer having functional groups such as hydroxyl groups, epoxide groups, and isocyanate groups in its molecule with a compound having a functional group that is reactive to said functional group and a silicon-containing reactive group.

[0055] Method (I) is preferred because the reaction is simple, the amount of silicon-containing reactive group introduced can be adjusted, and the physical properties of the resulting silicon-containing reactive group-containing polyoxyalkylene polymer are stable. Method (II) is preferred because it offers many reaction options and allows for easy increase in the introduction rate of silicon-containing reactive group. Method (I) or method (III), in which an organic polymer having a hydroxyl group at the terminal is reacted with a compound having an isocyanate group and a silicon-containing reactive group, is preferred because it can achieve a high conversion rate in a relatively short reaction time.

[0056] In method (I), chlorosilanes and alkoxysilanes are preferred as hydrosilane compounds. In particular, alkoxysilanes are most preferred because the resulting curable composition has stable hydrolysis properties and is easy to handle. Among the alkoxysilanes, methyldimethoxysilane is preferred because it is readily available and the resulting curable composition containing the organic polymer has high curability, storage stability, elongation properties, and tensile strength of the cured product. In addition, trimethoxysilane is preferred from the viewpoint of curability and resilience of the resulting curable composition. The hydrosilylation reaction may be accelerated using various catalysts. As catalysts for hydrosilylation, known catalysts such as various complexes of cobalt, nickel, iridium, platinum, palladium, rhodium, ruthenium, etc., may be used.

[0057] (II) The method includes, but is not limited to, a method of introducing a compound having a mercapto group and a silicon-containing reactive group into the unsaturated bonding site of a polymer by a radical addition reaction in the presence of various radical initiators and / or radical sources. Examples of the above-mentioned compounds having a mercapto group and a silicon-containing reactive group include, but is not limited to, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldiethoxysilane, mercaptomethyltrimethoxysilane, and mercaptomethyltriethoxysilane.

[0058] In method (III), the method for reacting an organic polymer having a hydroxyl group with a compound having an isocyanate group and a silicon-containing reactive group includes, for example, the method disclosed in Japanese Patent Publication No. 3-47825, but is not limited thereto. Examples of compounds having an isocyanate group and a silicon-containing reactive group include, but is not limited to, γ-isocyanate-propyltrimethoxysilane, γ-isocyanate-propylmethyldimethoxysilane, γ-isocyanate-propyltriethoxysilane, γ-isocyanate-propylmethyldiethoxysilane, isocyanate-methyltrimethoxysilane, isocyanate-methyltriethoxysilane, isocyanate-methyldimethoxymethylsilane, isocyanate-methyldiethoxymethylsilane, and the like.

[0059] The number-average molecular weight of component (A), as calculated in terms of polystyrene molecular weight using gel permeation chromatography (GPC), is preferably 3,000 to 100,000, and more preferably 5,000 to 30,000. If the number-average molecular weight is less than 3,000, the amount of silicon-containing reactive groups introduced per unit weight of the polyoxyalkylene polymer increases, which may be unsuitable from the viewpoint of manufacturing costs. Furthermore, if the number-average molecular weight exceeds 100,000, the curable composition tends to become highly viscous, which is undesirable from the viewpoint of handling. The molecular weight of the polyoxyalkylene polymer can also be expressed as the calculated molecular weight based on the end groups. The reduced molecular weight based on the end groups is determined by directly measuring the concentration of the end groups in the organic polymer precursor before the introduction of silicon-containing reactive groups, using titration analysis based on the principles of the hydroxyl value measurement method specified in JIS K1557 and the iodine value measurement method specified in JIS K 0070, while also taking into account the structure of the organic polymer (degree of branching determined by the polymerization initiator used). For polyoxyalkylene polymers, the reduced molecular weight based on the end groups may be obtained by creating calibration curves for the number average molecular weight obtained by general GPC measurement and the reduced molecular weight based on the end groups in the organic polymer precursor, and then converting the number average molecular weight obtained by GPC for the polyoxyalkylene polymer. The molecular weight distribution (Mw / Mn) of component (A) is not particularly limited, but 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. The molecular weight distribution of component (A) can be determined from the number-average molecular weight (Mn) and weight-average molecular weight (Mw) obtained by GPC measurement.

[0060] In another optional embodiment, the main chain of component (A) may contain urethane bonds and / or urea bonds, to the extent that it does not significantly affect the effects of the present invention.

[0061] Component (A) may contain only one type of polyoxyalkylene polymer having a silicon-containing reactive group, or it may be a composition containing two or more types of polyoxyalkylene polymers having a silicon-containing reactive group. In some specific embodiments of the present invention, component (A) is at least one selected from the group consisting of polyoxyalkylene polymers having 1.3 to 4 trimethoxysilyl groups and methyldimethoxysilyl groups per molecule, containing a silicon-based group, and having a number average molecular weight of 10,000 to 35,000.

[0062] The weight ratio of component (A) to the total weight of the curable composition may be adjusted as appropriate. Considering handling, curability, and cost, the weight ratio is preferably 18 to 90 wt%, more preferably 23 to 85 wt%, and particularly preferably 30 to 80 wt%.

[0063] <Ingredient (B)> The inventors have found that by adding a (meth)acrylic acid ester polymer having a trialkoxysilyl group (component (B)) to a curable composition and then carrying out a catalytic reaction using component (C) of the present invention, the curability is significantly improved and the curing time is shortened. If component (B) is not added, the catalytic activity of component (C) relative to component (A) is low. Furthermore, when using other (meth)acrylic acid ester polymers that do not have a trialkoxysilyl group, sufficient curability cannot be obtained even if a similar catalyst is used in combination or the amount of catalyst is increased.

[0064] Component (B) consists mainly of (meth)acrylate ester monomers as the main monomer units constituting its main chain. The (meth)acrylate ester monomers are not particularly limited, and various monomers can be used. Specifically, for example, 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, and (meth)acrylate Nonyl, Decyl (meth)acrylate, Dodecyl (meth)acrylate, Phenyl (meth)acrylate, Toluyl (meth)acrylate, Benzyl (meth)acrylate, 2-Methoxyethyl (meth)acrylate, 3-Methoxybutyl (meth)acrylate, 2-Hydroxyethyl (meth)acrylate, 2-Hydroxypropyl (meth)acrylate, Stearyl (meth)acrylate, Glycidyl (meth)acrylate, 3-(Dimethoxymethylsilyl)propyl (also known as γ-(meth)acryloyl) Examples include oxypropyldimethoxymethylsilane, 2-(dimethoxymethylsilyl)ethyl (meth)acrylate, 2-(dimethoxymethylsilyl)methyl (meth)acrylate, 2-(diethoxymethylsilyl)methyl (meth)acrylate, 3-[(methoxymethyl)dimethoxysilyl]propyl (meth)acrylate, ethylene oxaside 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, trifluoromethyl (meth)acrylate, bis(trifluoromethyl)methyl (meth)acrylate, 2-trifluoromethyl-2-perfluoroethylethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate.These (meth)acrylic acid ester monomers can be used one or more times. The content of (meth)acrylic acid ester monomer units is preferably 50% by weight or more, and more preferably 70% by weight or more, relative to the total (meth)acrylic acid ester polymer.

[0065] The monomer units constituting the main chain may include units formed from monomers containing a (meth)acryloyl group, other than the (meth)acrylic acid ester monomers described above. Examples of such monomers include (meth)acrylic acid; amide group-containing monomers such as N-methylolacrylamide and N-methylolmethacrylamide; epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate; and monomers containing nitrogen groups such as diethylaminoethyl acrylate and diethylaminoethyl methacrylate. One or more of these monomers may be used. Furthermore, the monomer units constituting the main chain may include units made from monomers that do not contain a (meth)acryloyl group (i.e., monomers that do not contain either an acryloyl group or a methylacryloyl group). Examples of such monomers include vinyl monomers copolymerizable with the (meth)acrylic acid ester monomers described above. Such vinyl monomers are not particularly limited and include, for example, styrene monomers such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, styrenesulfonic acid and its salts; fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, vinylidene fluoride; silicon-containing vinyl monomers such as vinyltrimethoxysilane, vinyltriethoxysilane; maleic anhydride, maleic acid, maleic acid monoalkyl esters and maleic acid dialkyl esters; fumaric acid, fumaric acid monoalkyl esters and fumaric acid dialkyl esters; maleimide, methyl maleic acid Examples include maleimide monomers such as imides, ethyl maleimide, propyl maleimide, butyl maleimide, hexyl maleimide, octyl maleimide, dodecyl maleimide, stearyl maleimide, phenyl maleimide, and cyclohexyl maleimide; nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile; vinyl ester monomers such as vinyl acetate and vinyl propionate; alkene monomers such as ethylene and propylene; conjugated diene monomers such as butadiene and isoprene; vinyl chloride; vinylidene chloride; allyl chloride; and allyl alcohol. One or more of these monomers can be used.

[0066] In some specific embodiments of the present invention, the main monomer units constituting the main chain of component (B) include methacrylate monomers and acrylic acid monomers.

[0067] Examples of trialkoxysilyl groups in component (B) include trimethoxysilyl groups, triethoxysilyl groups, and triisopropoxysilyl groups. In some preferred embodiments of the present invention, the trialkoxysilyl group is a trimethoxysilyl group.

[0068] The (meth)acrylic acid ester polymer, which is a precursor for producing component (B), may be produced by known methods. Such methods include, for example, conventional radical polymerization methods that use azo compounds, peroxides, etc., as polymerization initiators. Specifically, radical polymerization methods include methods in which polymerization initiators, chain transfer agents, solvents, etc., are added to carry out the polymerization reaction.

[0069] The method for introducing trialkoxysilyl groups into (meth)acrylic acid ester polymers is not particularly limited, but for example, the following method can be used.

[0070] (i): A method of copolymerizing a monomer having a trialkoxysilyl group with a monomer that does not have a silicon-containing reactive group. However, when this method is used, the trialkoxysilyl group tends to be randomly introduced into the main chain of the polymer. Examples of monomers having a trialkoxysilyl group include 3-(trimethoxysilyl)propyl (meth)acrylate and 3-methylacryloyloxypropyltrimethoxysilane (also known as γ-methylacryloyloxypropyltrimethoxysilane).

[0071] (ii) A polymerization reaction that produces a (meth)acrylic acid ester polymer using a mercaptosilane compound having a trialkoxysilyl group as a chain transfer agent. This method allows the trialkoxysilyl group to be introduced to the end of the polymer. An example of a mercaptosilane compound having a trialkoxysilyl group is 3-mercaptopropyltrimethoxysilane (also known as γ-mercaptopropyltrimethoxysilane).

[0072] Another method involves introducing silicon-containing reactive groups by modifying the terminal functional groups of (meth)acrylic acid ester polymers synthesized by active radical polymerization. Since (meth)acrylic acid ester polymers obtained by active radical polymerization readily accept the introduction of functional groups at the polymer's terminals, silicon-containing reactive groups can be introduced at the polymer's terminals through modification. Any modification reaction can be used for this method, and for example, the following methods can be employed: a method using a compound having a functional group that can react with the terminal reactive group obtained by polymerization and a silicon-containing group; a method using a compound having a functional group that can react with the terminal reactive group and a double bond to introduce a double bond at the polymer's terminal, and then introducing a silicon-containing reactive group by hydrosilylation, etc.

[0073] The methods described above may be used in any combination. For example, when combining method (i) and method (ii), a (meth)acrylic acid ester polymer having trialkoxysilyl groups at both the main chain end and the side chain end of the molecular chain can be obtained.

[0074] In some specific embodiments of the present invention, component (B) may include other silicon-containing reactive groups, such as a dimethoxymethylsilyl group or a diethoxymethylsilyl group, and preferably a dimethoxymethylsilyl group. The method for introducing the other silicon-containing reactive group is the same as the method for introducing the trialkoxysilyl group.

[0075] In the present invention, component (B) may contain only one type of (meth)acrylic acid ester polymer having a trialkoxysilyl group, or it may be a composition containing two or more types of (meth)acrylic acid ester polymers having a trialkoxysilyl group. The molecular weight of component (B) is not particularly limited. In some specific embodiments of the present invention, the number average molecular weight of component (B) is 1,500 or more, preferably 3,500 or less, as the molecular weight converted to polystyrene in GPC.

[0076] In a curable composition, the mass ratio (also called the content ratio) of component (A) to component (B) is not particularly limited. In some specific embodiments of the present invention, the percentage of component (B) to the total mass of component (A), component (B), and any component (D) is 18% or more, more preferably 20% or more, and more preferably 30% or more. In some other specific embodiments of the present invention, the mass ratio of component (A) to component (B) is (9-1.2):1, more preferably (5-1.5):1. If the content of component (B) is too low, the effect of improving curability is difficult to exhibit, and if the content of component (B) is too high, the mechanical strength of the cured product tends to decrease. Also, if component (A) is not added to the curable composition, component (C) does not easily exhibit sufficient curing catalytic activity with respect to component (B).

[0077] <Component (C)> The non-organotin catalyst used in the present invention mainly comprises a silane compound having a guanidine group, represented by general formula (1).

[0078] [ka] In the formula, R 1 ~R 4 , R 6 Each of these is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and R 5 Each of these is independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, m is an integer from 2 to 5, and a is an integer from 0 to 2.

[0079] In this invention, we have unexpectedly discovered the following about such compounds: namely, they exhibit high catalytic activity and short curing time in a curable composition system consisting of components (A) and (B) in this invention; they also exhibit high compatibility within the composition of this invention, are easy to process, and have a lower tendency to undergo catalyst separation or transition compared to catalysts such as DBU; and furthermore, the mechanical performance of the cured product is ensured, and the cured product can be firmly attached to the surface of various substrates, particularly polymethyl methacrylate substrates, polyvinyl chloride substrates, and metal substrates. Note that aryl-substituted biguanide catalysts such as 1-o-tolyl biguanide are solids at room temperature, and therefore, when added to a curable composition as a curing catalyst at the end, they can cause problems such as agglomeration in terms of dispersibility. On the other hand, component (C) in this invention is a liquid even at room temperature and therefore has excellent dispersibility.

[0080] In this invention, R 1 ~R 4 , R 6 Each of these is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and R 5 Each of these is independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. C1 to 20 alkyl groups include linear or branched alkyl groups, and include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, isohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, etc. Furthermore, R 1 ~R 6 Each of these is independently an alkyl group having 1 to 6 carbon atoms, such as a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, isohexyl group, etc. In some specific embodiments of the present invention, R 1 ~R 4 , R 6Each of these is independently a hydrogen atom or a substituted C1-C20 alkyl group, and examples of such substituents include halogens, hydroxyl groups, carboxyl groups, nitro groups, cyano groups, methoxy groups, ethoxy groups, phenoxy groups, furyl groups, chenyl groups, etc. In some preferred embodiments of the present invention, R 1 ~R 4 , R 6 Each of them is independently hydrogen and an alkyl group having 1 to 6 carbon atoms, and R 5 Each of these is independently an alkyl group having 1 to 6 carbon atoms, and furthermore, R 1 ~R 6 Each of these is independently an alkyl group having 1 to 6 carbon atoms. In some preferred embodiments of the present invention, R 1 ~R 6 Each of these is independently a methyl group, an ethyl group, and / or a propyl group. In another preferred embodiment of the present invention, m is an integer from 2 to 4, and furthermore, m is 3. In some specific embodiments of the present invention, component (C) is one or more selected from tetramethylguanidinepropyltrimethoxysilane, tetramethylguanidinepropylmethyldimethoxysilane, tetramethylguanidinepropyldimethylmethoxysilane, and tetramethylguanidinepropyltriethoxysilane. Considering availability and cost, etc., in general formula (1), R 1 ~R 4 , R 6 Each of the elements is independently methyl, m is preferably 3, and a is preferably 0. That is, as component (C), commercially available tetramethylguanidine propyltrimethoxysilane (CAS registration number: 69709-01-9) is preferred. Its molecular formula is as follows.

[0081] [ka] The catalyst of general formula (1) of the present invention may also be in the form of a tautomer. Within the scope of the present invention, all conceivable tautomers of the catalyst of the present invention are considered to have equivalent effects. The catalyst in the present invention may exist in a protonated form.

[0082] Within the limits that do not impair the effects of the present invention, component (C) may be used in combination with other curing catalysts, such as other guanidine catalysts, non-tin catalysts such as amidines, or small amounts of tin catalysts. From the viewpoint of toxicity or environmental impact, it is preferable to suppress the content of tin elements in the curable composition as much as possible. The content of tin compounds in the curable composition is preferably 1000 ppm or less, more preferably 500 ppm or less, and even more preferably the curable composition does not contain tin compounds, i.e., a non-tin catalyst is used in the curable composition. In a preferred embodiment of the present invention, the present invention includes only one type of silanol condensate catalyst as component (C). The amount of component (C) used is not particularly limited. In some specific embodiments of the present invention, the content (amount used) of component (C) is 0.1 to 10 parts by weight, more preferably 0.5 to 8 parts by weight, and more preferably 1 to 5 parts by weight, relative to 100 parts by weight of the total mass of component (A) and component (B). If the content of component (C) is too low, the reaction rate may be insufficient, and if the content is too high, the reaction rate will be too fast, which will shorten the handling time of the composition, resulting in poor workability or poor storage stability.

[0083] <Other polymers> Within the limits that do not impair the effects of the present invention, the composition of the present invention may contain, in addition to components (A) and (B), a (meth)acrylic acid ester polymer having another silicon-containing reactive group (hereinafter referred to as "(meth)acrylic acid ester polymer (D)"). Examples of silicon-containing reactive groups of (meth)acrylic acid ester polymer (D) include a dimethoxymethylsilyl group and a diethoxymethylsilyl group, with a dimethoxymethylsilyl group being preferred. Considering the required curability, when the total amount of component (B) and (meth)acrylic acid ester polymer (D) is 100% by weight, the content of component (B) is 60% by weight or more, more preferably 80% by weight or more, and even more preferably does not contain (meth)acrylic acid ester polymer (D).

[0084] <Other ingredients> Within the limits that do not impair the effects of the present invention, the curable composition of the present invention may contain other components in addition to the above-mentioned components (A) to (C) and any component (D). These other components are described below.

[0085] In some specific embodiments of the present invention, the curable composition of the present invention comprises a plasticizer. The plasticizer may be any known plasticizer, and specific examples of plasticizers include phthalate ester compounds such as dibutyl phthalate, diisononyl phthalate (DINP), diheptyl phthalate, di(2-ethylhexyl) phthalate, diisodecyl phthalate (DIDP), and butyl benzyl phthalate; terephthalate esters such as bis(2-ethylhexyl) 1,4-benzenedicarboxylate; non-phthalate ester compounds such as diisononyl 1,2-cyclohexanedicarboxylate; dioctyl adipicate, dioctyl sebacate, and sebacin This includes aliphatic polycarboxylic acid ester compounds such as dibutyl acid, diisodecyl succinate, and tributyl acetylcitrate; unsaturated fatty acid ester compounds such as butyl oleate and methyl acetylricinoleate; alkyl sulfonate phenyl esters; phosphate ester compounds such as tricresyl phosphate and tributyl phosphate; trimellitic acid ester compounds; paraffin chloride; hydrocarbon oils such as alkyldiphenyl and partially hydrogenated terphenyl; and epoxide plasticizers such as epoxidized soybean oil and benzyl epoxidstearate. Furthermore, the plasticizer may also include polymeric plasticizers, such as polyoxyalkylenes; (meth)acrylic acid ester polymers; esters of polyalkylene glycols such as diethylene glycol dibenzoate, triethylene glycol dibenzoate, and pentaerythritol ester; polyesters obtained from dibasic acids such as sebacic acid, adipic acid, azelaic acid, and phthalic acid, and dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol; polyethers obtained by urethaneizing the hydroxyl groups of polyether polyols, polyethers obtained by carboxylic acid esterification, and polyethers obtained by terminal etherification; polystyrenes such as polystyrene and poly-α-methylstyrene; polybutadiene, polybutene, polyisobutylene, butadiene-acrylonitrile, and polychloroprene; and hydrogenated polybutadiene oligomers such as hydrogenated α-olefins. These may be used individually or in combination of two or more. Plasticizers are effective in reducing the viscosity of the composition and improving its processability.In one specific embodiment of the present invention, the plasticizer is preferably one or more types selected from phthalate esters, saturated or unsaturated fatty acid ester compounds, phosphate ester compounds, epoxide plasticizers, or polymer plasticizers, and is particularly preferably diisononyl phthalate. The content of the plasticizer is preferably 10 to 120 parts by weight, and more preferably 20 to 100 parts by weight, per 100 parts by weight of the total mass of component (A) and component (B). If the amount is less than 10 parts by weight, the viscosity reduction effect is weak and the processability is insufficient. If the amount exceeds 120 parts by weight, sufficient mechanical performance cannot be obtained, for example, the tensile strength of the cured product decreases.

[0086] In some specific embodiments of the present invention, the curable composition of the present invention further comprises an inorganic filler. The inorganic filler is not particularly limited and may be any known general inorganic filler, such as reinforcing fillers such as fumed silica, precipitated silica, crystalline silica, fused silica, calcined clay, clay and kaolin; calcium carbonate, dolomite, anhydrous silicic acid, hydrated silicic acid, magnesium carbonate, diatomaceous earth, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, aluminum fine powder, zinc oxide, activated zinc oxide, resin powders such as PVC powder and PMMA powder; and fibrous fillers such as glass fibers. These may be used individually or in combination of two or more. The inorganic filler is effective in improving the dispersion stability of the composition and the strength of the cured product. In particular, from the viewpoint of ease of handling, availability and cost, the inorganic filler is preferably calcium carbonate. The calcium carbonate may be at least one selected from heavy calcium carbonate, precipitated calcium carbonate and calcium carbonate obtained after surface treatment of these calcium carbonates. Precipitating calcium carbonate includes light calcium carbonate with a longitudinal size of 1 μm or more, and colloidal calcium carbonate with an average particle diameter of 1 μm or less. The average particle diameter of heavy calcium carbonate is preferably 0.3 to 10 μm, more preferably 0.7 to 7 μm, particularly preferably 0.7 to 5 μm, and most preferably 1.1 to 4 μm. Because excellent mechanical properties can be obtained, the inorganic filler is preferably selected from colloidal calcium carbonate or surface-treated colloidal calcium carbonate. Examples of surface treatment agents include fatty acids such as stearic acid, fatty acid esters, modified fatty acids, resin acids such as rosin, paraffin, polyethylene wax, and cationic surfactants. In some specific embodiments, the inorganic filler is preferably colloidal calcium carbonate treated with fatty acids or resin acids. The content of the inorganic filler is preferably 10 to 500 parts by weight, more preferably 50 to 450 parts by weight, and even more preferably 200 to 400 parts by weight, based on 100 parts by weight of the total mass of component (A) and component (B). If the amount is less than 10 parts by weight, it may adversely affect dispersion stability and strength, and if it exceeds 500 parts by weight, the viscosity of the composition system tends to increase and processability decreases.

[0087] In some specific embodiments of the present invention, the curable composition of the present invention further comprises a stabilizer. Specific examples of stabilizers include antioxidants, light stabilizers, and ultraviolet absorbers. Antioxidants can improve the weather resistance of the cured product. Examples of antioxidants include hindered phenols, monophenols, bisphenols, and polyphenols, with hindered phenols such as Irganox 245 being particularly preferred. The content of the antioxidant is preferably 0.1 to 10 parts by weight, and particularly preferably 0.2 to 5 parts by weight, per 100 parts by weight of the total mass of component (A) and component (B). Light stabilizers can prevent deterioration of the cured product due to photo-oxidation. Specific examples of light stabilizers include benzotriazole compounds, hindered amine compounds, and benzoate compounds, with hindered amine compounds being particularly preferred. The content of the light stabilizer is preferably 0.1 to 10 parts by weight, and further preferably 0.2 to 5 parts by weight, per 100 parts by weight of the total mass of component (A) and component (B). UV absorbers can improve the weather resistance of the surface of the cured product. Specific examples of UV absorbers include benzophenone compounds, benzotriazole compounds, salicylate compounds, substituted tolyl compounds, and metal chelate compounds, with benzotriazole compounds being particularly preferred. The content of the UV absorber is 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, per 100 parts by weight of the total mass of component (A) and component (B).

[0088] In some specific embodiments of the present invention, the curable composition of the present invention further comprises a thickening agent. The thickening agent comprises a silane coupling agent, a reaction product of a silane coupling agent, or a compound other than a silane coupling agent.Specific examples of silane coupling agents include, for example, amino group-containing silanes such as γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, 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, (aminomethyl)dimethoxymethylsilane, (aminomethyl)trimethoxysilane, (phenylaminomethyl)dimethoxymethylsilane, (phenylaminomethyl)trimethoxysilane, bis(3-trimethoxysilylpropyl)amine, and γ-mercaptopropyltri Mercapto group-containing silanes such as methoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, and γ-mercaptopropylmethyldiethoxysilane; epoxy group-containing silanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β-(3,4-epoxidecyclohexyl)ethyltrimethoxysilane, and β-(3,4-epoxidecyclohexyl)ethyltriethoxysilane. Examples include silanes; reaction products of amino group-containing silanes and epoxy group-containing silanes; reaction products of mercapto group-containing silanes and epoxy group-containing silanes; reaction products of amino group-containing silanes and epoxide resins; reaction products of mercapto group-containing silanes and epoxide resins; siloxane acetates, such as ethoxysilane, tetraethoxysilane tetramer, and tetraethoxysilane hexamer; and vinyl group silanes, such as vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltriethoxysilane. These silane coupling agents may be used individually or in combination of two or more. Reaction products of various silane coupling agents may also be used.Examples of the reaction products include reaction products of isocyanate silane and hydroxyl group-containing compounds, reaction products of isocyanate silane and amino group-containing compounds, reaction products of aminosilane and (meth)acryloyl group-containing compounds (Michael addition reaction products), reaction products of aminosilane and epoxy group-containing compounds, reaction products of epoxy group silane and carboxylic acid group-containing compounds, and reaction products of epoxy group silane and amino group-containing compounds. Reaction products of silane coupling agents themselves may also be used, such as reaction products of isocyanate silane and aminosilane, reaction products of aminosilane and (meth)acryloyl group-containing silane, reaction products of aminosilane and epoxy group silane, and reaction products of aminosilane and acid anhydride-containing silane. One or more of these reaction products can be used. Specific examples of thickeners other than silane coupling agents are not particularly limited, but include, for example, epoxide resins, phenolic resins, sulfur, alkyl titanates, aromatic polyisocyanates, etc. The thickening agent may be used alone or in a mixture of two or more types. The addition of a thickening agent can improve adhesion to the substrate. The amount of thickening agent per 100 parts by weight of the total mass of component (A) and component (B) is usually in the range of 0.1 to 20 parts by weight, preferably in the range of 0.5 to 15 parts by weight.

[0089] In some specific embodiments of the present invention, the curable composition of the present invention may further contain a dehydrating agent. Examples of dehydrating agents include synthetic zeolite, activated alumina, silica gel, quicklime, magnesium oxide, alkoxysilane compounds (e.g., n-propyltrimethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, methyl silicate, ethyl silicate, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, etc.), oxazolidine compounds, isocyanate compounds, etc., and more preferably vinyltrimethoxysilane. The content of the dehydrating agent is preferably 0.1 to 20 parts by weight, and particularly preferably 0.5 to 10 parts by weight, per 100 parts by weight of the total mass of component (A) and component (B).

[0090] The curable composition of the present invention may contain various additives as needed for the purpose of adjusting the curable composition or other physical properties of the cured product. Examples of such additives include flame retardants, radical inhibitors, metal deactivators, ozone degradation inhibitors, phosphorus-based peroxide decomposers, lubricants, pigments, foaming agents, solvents, and antifungal agents. Each type of additive may be used individually or in combination of two or more types.

[0091] In some specific embodiments of the present invention, the curable composition further comprises calcium carbonate, a plasticizer, a small amount of antioxidant, a thickener, and a dehydrating agent, in addition to components (A) to (C).

[0092] <Preparation of curable composition> In this invention, components (A), (B), and optionally added component (D) are uniformly mixed using a conventional method, and then a polymer mixture is obtained by distilling off a solvent such as isobutyl alcohol using an evaporator. Subsequently, other components are added to the polymer mixture to prepare the curable composition of the present invention.

[0093] The curable composition of the present invention may be prepared as a one-component type, in which the polymer mixture and other components are pre-combined and sealed for storage, and then cured by moisture in the air after application. Alternatively, it may be prepared as a two-component type, in which a curing agent, which is pre-combined with components such as a curing catalyst, filler, plasticizer, and water, is mixed with the polymer composition immediately before use. From the viewpoint of workability, the one-component type is preferred.

[0094] When preparing the curable composition of the present invention as a single-component composition, it is preferable to dehydrate and dry any water-containing components beforehand, or to dehydrate them by reducing pressure during kneading. When dehydrating or drying solid materials such as powders, heat drying or reduced-pressure dehydration is preferred, and when dehydrating or drying liquid materials, reduced-pressure dehydration or a method using a dehydrating agent is preferred.

[0095] The method for preparing the curable composition of the present invention is not particularly limited, but conventional methods may be used, such as blending the above components and kneading them at room temperature or under heating using a mixer, roll, kneader, etc., or dissolving and mixing the components using a small amount of solvent.

[0096] <Cured product> When the curable composition of the present invention is exposed to the atmosphere, a three-dimensional network structure is formed by the action of moisture, and it hardens to become a cured product with rubber elasticity.

[0097] <Application> The curable composition of the present invention can be used in applications such as adhesives, and can be used as a sealing material, waterproofing material, molding material, vibration damping material, soundproofing material, foaming material, paint, spray material, etc. for buildings, ships, automobiles, roads, etc. Because the curable composition of the present invention has excellent mechanical properties and adhesive properties for the cured product obtained, its use as a sealing material or adhesive is more preferable among the above materials. In particular, it can be used for gap sealing and elastic adhesive joints in construction and industrial applications, and for elastic paints with crack crosslinking function, or for the protection and / or sealing of ceilings, floors, verandas, parking lots, or concrete pipes.

[0098] The present invention will be described in more detail below with reference to examples, comparative examples, and synthesis examples, but the present invention is not limited to the following examples.

[0099] (Examples) The number-average molecular weights listed below were measured using gel permeation chromatography (GPC) (Tosoh Corporation, HLC-8120GPC). A TSKgelH type column (Tosoh Corporation) was used. A tetrahydrofuran (THF) solution containing the dissolved polymer was prepared and measured at 40°C. The number-average molecular weight (Mn) was calculated using a conversion based on standard polystyrene.

[0100] For component (A), the average number of silicon-containing reactive groups per molecule is determined by the high resolution of the protons of the carbon directly bonded to the silicon-containing reactive groups. 1The result was determined by quantitative analysis using 1H NMR.

[0101] <Preparation of component (A)> (Synthesis Example 1-1) Using polypropylene glycol with a number average molecular weight of 3,000 as an initiator and zinc hexacyanocobalt glycol dimethyl ether complex catalyst, propylene oxide was polymerized to obtain polyoxypropylene with hydroxyl groups at both ends and a number average molecular weight of 30,000. Subsequently, 1.2 molar equivalents of a methanol solution of sodium methoxide were added relative to the hydroxyl groups of the polyoxypropylene. After removing the methanol by vacuum defoliation, 1.3 molar equivalents of allyl chloride were added to the reaction solution relative to the hydroxyl groups of the polyoxypropylene to convert the terminal hydroxyl groups to allyl groups. The obtained unpurified polyoxypropylene with allyl groups at the ends was mixed with n-hexane and water, stirred, and then the water was removed by centrifugation. The metal salts in the polymer (polyoxypropylene) were removed from the obtained hexane solution by vacuum defoliation of the hexane. The obtained polyoxypropylene having allyl groups at the terminal was reacted with trimethoxysilane in the presence of a platinum-based catalyst to obtain polyoxypropylene (MS-1) having trimethoxysilyl groups at the terminal and a number-average molecular weight of 30,000. (MS-1) has hydrolyzable silyl groups and has an average of 1.5 trimethoxysilyl groups per molecule.

[0102] (Synthesis Example 1-2) The synthesis was carried out in the same manner as in Synthesis Example 1-1, except that a polyoxypropylene triol with a number-average molecular weight of 3,000 was used as an initiator and the amount of propylene oxide used to adjust the molecular weight was changed. Polyoxypropylene (MS-2) with a trimethoxysilyl group at the terminus and a number-average molecular weight of 29,000 was obtained. (MS-2) has hydrolyzable silyl groups and has an average of 2.4 trimethoxysilyl groups per molecule.

[0103] (Synthesis Examples 1-3) Using polypropylene glycol with a number average molecular weight of 3,000 as an initiator and zinc hexacyanocobalt glycol dimethyl ether complex catalyst, propylene oxide was polymerized to obtain polyoxypropylene with hydroxyl groups at both ends and a number average molecular weight of 30,000. Subsequently, 1.2 molar equivalents of a methanol solution of sodium methoxide was added to the hydroxyl groups of the polyoxypropylene. After removing methanol by vacuum defoliation, 1.0 molar equivalent of allyl glycidyl ether was added to the reaction solution and reacted at 130°C for 2 hours. Then, 0.3 molar equivalents of a methanol solution of sodium methoxide were added to remove methanol, and 1.8 molar equivalents of allyl chloride were added to the reaction solution to convert the terminal hydroxyl groups to allyl groups. The obtained unpurified polyoxypropylene with allyl groups was mixed with n-hexane and water, stirred, and then the water was removed by centrifugation. The metal salts in the polymer (polyoxypropylene) were removed from the obtained hexane solution by defloration under reduced pressure. The resulting polyoxypropylene, which has allyl groups at the terminals, was reacted with trimethoxysilane in the presence of a platinum-based catalyst to obtain polyoxypropylene (MS-3) having trimethoxysilyl groups at the terminals and a number-average molecular weight of 30,000. (MS-3) has hydrolyzable silyl groups and has an average of 3.4 trimethoxysilyl groups per molecule.

[0104] (Synthesis Examples 1-4) The synthesis was carried out in the same manner as in Synthesis Example 1-1, except that polyoxypropylene triol and polypropylene glycol, with a number-average molecular weight of 3,000 and a weight ratio of 1:1, were used as initiators, the amount of propylene oxide used to adjust the molecular weight was changed, and methyldioxymethylsilane was used instead of trimethoxysilane. Polyoxypropylene (MS-4) with methyldioxymethylsilyl groups at the termini and a number-average molecular weight of 21,000 was obtained. (MS-4) has hydrolyzable silyl groups and has an average of 1.8 methyldioxymethylsilyl groups per molecule.

[0105] (Synthesis Examples 1-5) The synthesis was carried out in the same manner as in Synthesis Example 1-1, except that the amount of propylene oxide used to adjust the molecular weight was changed and methyldioxymethylsilane was used instead of trimethoxysilane. Polyoxypropylene (MS-5) with methyldioxymethylsilyl groups at the termini and a number-average molecular weight of 26,000 was obtained. (MS-5) has hydrolyzable silyl groups and has an average of 1.3 methyldioxymethylsilyl groups per molecule.

[0106] (Synthesis Examples 1-6) The synthesis was carried out in the same manner as in Synthesis Example 1-1, except that the amount of propylene oxide used to adjust the molecular weight was changed and methyldioxymethylsilane was used instead of trimethoxysilane. Polyoxypropylene (MS-6) with methyldioxymethylsilyl groups at the termini and a number-average molecular weight of 15,000 was obtained. (MS-6) has hydrolyzable silyl groups and has an average of 1.6 methyldioxymethylsilyl groups per molecule.

[0107] (Synthesis Examples 1-7) The procedure was carried out in the same manner as in Synthesis Example 1-1, except that the amount of propylene oxide used to adjust the molecular weight was changed. Polyoxypropylene (MS-7) with a trimethoxysilyl group at the terminus and a number-average molecular weight of 15,000 was obtained. (MS-7) has hydrolyzable silyl groups and has an average of 1.6 trimethoxysilyl groups per molecule.

[0108] <Preparation of component (B)> (Synthesis Example 2-1) To 200 g of isobutyl alcohol heated to 105°C, a mixed solution consisting of 350 g of methyl methacrylate, 100 g of 2-ethylhexyl acrylate, 50 g of 3-methylacryloyloxypropyltrimethoxysilane, 25 g of γ-mercaptopropyltrimethoxysilane, 100 g of isobutyl alcohol, and 12.5 g of azobisisobutyronitrile (polymerization initiator) was added dropwise over 4 hours. Post-polymerization was then carried out for 2 hours. This yielded a (meth)acrylic acid ester polymer (A-1) solution with a solid content of approximately 60%. The number-average molecular weight of (A-1), measured by GPC, was 2,500.

[0109] (Synthesis Example 2-2) The synthesis was carried out in the same manner as in Synthesis Example 2-1, except that 350 g of methyl methacrylate, 100 g of 2-ethylhexyl acrylate, 25 g of 3-methylacryloyloxypropyltrimethoxysilane, and 10 g of γ-methylacryloyloxypropylmethyldimethoxysilane were used as monomers, without the addition of γ-mercaptopropyltrimethoxysilane. A solution of (meth)acrylic acid ester polymer (A-2) was obtained. The number-average molecular weight of (A-2), measured by GPC, was 2,800.

[0110] (Synthesis Example 2-3) The synthesis was carried out in the same manner as in Synthesis Example 2-1, except that 250 g of methyl methacrylate, 50 g of 2-ethylhexyl acrylate, 100 g of butyl acrylate, 50 g of stearyl methacrylate, and 35 g of γ-methylacryloyloxypropylmethyldimethoxysilane were used as monomers, without the addition of γ-mercaptopropyltrimethoxysilane, and 13.5 g of azobisisobutyronitrile (polymerization initiator) was used. A solution of (meth)acrylic acid ester polymer (A-3) was obtained. The number-average molecular weight of (A-3), measured by GPC, was 9,000.

[0111] (Synthesis Example 2-4) The synthesis was carried out in the same manner as in Synthesis Example 2-1, except that 50 g of methyl methacrylate, 350 g of butyl acrylate, 50 g of stearyl methacrylate, and 15 g of γ-methylacryloyloxypropylmethyldimethoxysilane were used as monomers, without the addition of γ-mercaptopropyltrimethoxysilane, and 2.5 g of azobisisobutyronitrile (polymerization initiator) was used. A solution of (meth)acrylic acid ester polymer (A-4) was obtained. The number-average molecular weight of (A-4), measured by GPC, was 18,000.

[0112] (Synthesis Example 2-5) The synthesis was carried out in the same manner as in Synthesis Example 2-1, except that 350 g of methyl methacrylate, 50 g of 2-ethylhexyl acrylate, 25 g of butyl acrylate, 50 g of stearyl methacrylate, and 30 g of γ-methylacryloyloxypropylmethyldimethoxysilane were used as monomers, without the addition of γ-mercaptopropyltrimethoxysilane, and 15 g of azobisisobutyronitrile (polymerization initiator) was used. A solution of (meth)acrylic acid ester polymer (A-5) was obtained. The number-average molecular weight of (A-5), measured by GPC, was 2,000.

[0113] (Synthesis Example 2-6) 1000g of butyl acrylate was added to a prepared 2000mL three-necked flask.

[0114] In a separately prepared stirring vessel, 53 mg of copper bromide (CuBr2), 54 mg of hexamethyltri(2-aminoethyl)amine (Me6TREN), and 1.8 g of methanol were added and stirred under a flow of nitrogen gas until a homogeneous solution was obtained. This homogeneous solution is called the copper solution.

[0115] In a separately prepared stirring vessel, 31 mL of methanol, 1.0 g of ascorbic acid, and 1.6 mL of triethylamine were added, and the mixture was stirred for 30 minutes under a flow of nitrogen gas to prepare a homogeneous solution called ascorbic acid solution.

[0116] (first step) 5.8 g of ethyl α-bromobutyrate (initiator), 20 wt% of the above butyl acrylate monomer, 14 g of 3-(trimethoxysilyl)propyl methacrylate, 152 g of methanol (manufactured by Wako Pure Chemical Industries, Ltd.), and the entire amount of copper solution were added to a separately prepared stirring vessel and stirred for 30 minutes under a flow of nitrogen gas to prepare a homogeneous solution. The jacket temperature was 45°C.

[0117] Subsequently, when the polymerization system temperature reached 40°C or higher, the ascorbic acid solution was continuously added dropwise to initiate the polymerization reaction. The dropping rate of the ascorbic acid solution was 144 mg / hour.

[0118] When the temperature of the polymerization system was monitored and measured, the temperature rose as soon as the ascorbic acid was added dropwise, reached a maximum temperature, and then gradually decreased. When the temperature difference between the polymerization system temperature and the jacket temperature reached 1°C, a small amount of the reaction solution in the polymerization system was taken and analyzed by gas chromatography, and it was found that 90% by weight of butyl acrylate monomer had been consumed.

[0119] (Second process) The butyl acrylate monomer remaining from the first step was continuously added dropwise to the polymerization system over 150 minutes, and polymerization was carried out until 94% by weight of the monomer was consumed, as determined by gas chromatography analysis.

[0120] (Third step) Subsequently, 13 g of 3-(trimethoxysilyl)propyl methacrylate was added to the polymerization system. Ascorbic acid solution was continuously added over 1.5 hours to complete the polymerization.

[0121] The jacket temperature was changed to 80°C to allow the solvent to evaporate. After evaporation, the jacket temperature was cooled to below 60°C.

[0122] (purification) 1000 g of butyl acetate was added to a mixer with a temperature-controlled jacket, and the evaporated polymer was mixed in. The mixture was stirred until the solution was homogeneous. An adsorbent was added to the homogeneous solution, and the mixture was stirred for 1 hour. 10 g of Kyoward 500SH (manufactured by Kyowa Chemical Industry Co., Ltd.) and 10 g of Kyoward 700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) were used as adsorbents. After stirring, the resulting mixture was filtered to obtain the supernatant solution of the polymer. The solvent in the solution was then evaporated to obtain the acrylic acid polymer (A-6). The number-average molecular weight of the obtained (A-6) was 38,000.

[0123] <Preparation of Polymer Mixture> In the example where components (A) ((MS-1) to (MS-7)) and components (B) ((A-1) to (A-6)) are used in combination, the polymer mixture is first obtained by the following method, and then the cured composition is prepared.

[0124] The solution of the (meth)acrylic acid ester polymer obtained in the synthesis example was homogeneously mixed with component (A) so that the weight of the (meth)acrylic acid ester polymer in terms of solid content matched the weight shown in the table. Then, the isobutyl alcohol was removed using an evaporator to obtain the polymer mixture.

[0125] (Examples 1-4 and Comparative Examples 1-8) Under conditions of 23°C / 50%RH (i.e., 23°C, 50% relative humidity), the polymer mixture prepared by the method described above was weighed according to the parts by weight listed in Table 1, and the silane and catalyst were added in the same parts by weight as shown in Table 1 and thoroughly mixed. The mixture was placed in a small cup, and the surface of the mixture was touched at regular short intervals. The time until a surface skin was formed was measured as the curing time. The results are shown in Table 1.

[0126] <Preparation of curable composition> (Examples 5-8 and Comparative Examples 9-11) Components (A) and (B) were weighed according to the weight ratios shown in Table 2, and after being uniformly mixed, the isobutyl alcohol was removed using an evaporator to obtain a polymer mixture.

[0127] 100 parts by weight of the obtained polymer mixture was thoroughly mixed with a composition consisting of 50 parts by weight of diisononyl phthalate as a plasticizer, 60 parts by weight of heavy calcium carbonate (trade name LM2200), 100 parts by weight of precipitated calcium carbonate (trade name 200A), and 1 part by weight of an antioxidant (trade name Irganox 245).

[0128] The resulting mixture was dehydrated under reduced pressure at 120°C for 2 hours and cooled to below 50°C. Then, under conditions of 23°C / 50%RH, 2 parts by weight of vinyltrimethoxysilane (trade name WD-21) and 2 parts by weight of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane (trade name WD-51) were added. Finally, 2 parts by weight of tetramethylguanidinepropyltrimethoxysilane (trade name N-GCF) was added as a curing catalyst and kneaded to obtain a curable composition. The composition, which was substantially free of moisture, was sealed in a moisture-proof barrel.

[0129] (Comparative Examples 12-13) The procedure was carried out in the same manner as in Examples 5 to 8, except that the curing catalyst was changed from tetramethylguanidine propyltrimethoxysilane to 1,8-diazabicyclo[5.4.0]undeca-7-ene (trade name DBU, manufactured by Sunapro Co., Ltd.) (abbreviated as DBU in the following table) or a solution of phenylguanidine dissolved in dipropylene glycol n-butyl ether (45 wt% solution) (abbreviated as PGF in the following table).

[0130] (Evaluation of characteristics) The surface curing time of the curable compositions obtained in Examples 5-8 and Comparative Examples 9-13 was measured, and the tensile properties of the cured products and the adhesive properties of the curable compositions were measured and evaluated. The presence or absence of catalyst precipitation was also examined. The results are shown in Table 2.

[0131] <Surface hardening time (SFT)> The curable composition was spread with a spatula to a thickness of approximately 3 mm. At regular intervals, a mini spatula was brought into contact with the surface of the mixture, and the time until the mixture no longer adhered to the spatula was observed. This time was recorded as the surface curing time.

[0132] <Tensile properties> The curable composition was filled into a 3mm thick polyethylene mold to prevent air bubbles from forming, and aged for 3 days at 23°C / 50%RH, and then for 4 days at 50°C to obtain a cured product. Based on JIS K 6251, the obtained cured product was punched out to obtain a No. 7 dumbbell-shaped test sheet, and then a tensile test (tensile speed 200 mm / min, 23°C, relative humidity 50%) was performed to measure the stress at 50% elongation, stress at 100% elongation (M50, M100), strength at break (TB), and elongation at break (%). The results are shown in Table 2.

[0133] <Adhesiveness> Under conditions of 23°C / 50%RH, the curable composition was spread onto substrates (polycarbonate, acrylic, aluminum, and rigid PVC) into a rectangle approximately 30 mm long, 15 mm wide, and 10 mm thick, and pressed to ensure close bonding with the substrate. The mixture was cured under similar conditions for 7 days, after which a test was conducted to peel the cured material by hand at a 90° angle. CF represents 100% cohesive failure, and AF represents failure at the adhesive interface. CF70% means 70% cohesive failure.

[0134] <Surface observation> The curable composition was cured at 23°C / 50%RH for 7 days to obtain a cured product. The cured product was observed visually to check for the presence or absence of catalyst deposition on its surface. [Table 1]

[0135] [Table 2] As can be seen from Tables 1 and 2, when the curable composition contains component (A), a specific component (B), and a catalyst suitable for the present invention, there is no catalyst precipitation, the curing rate is significantly improved, and the tensile properties and adhesive properties of the curable composition after curing are excellent.

Claims

1. Component (A) A polyoxyalkylene polymer having a silicon-containing reactive group, Component (B) A (meth)acrylic acid ester polymer having a trialkoxysilyl group, Component (C) comprises a catalyst represented by general formula (1), 【Chemistry 1】 (In the formula, R １ ~R ４ , R ６ Each is independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and R ５ Each of these is independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, m is an integer from 2 to 5, and a is an integer from 0 to 2. The curable composition is characterized in that component (A) has one or more silicon-containing reactive groups represented by general formula (2). -Si(R 7 ) 3-b X b (2) (In the formula, each R7 is independently a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C7-C20 aralkyl group, or a triorganosiloxy group represented by -OSi(R')3; each R' is independently a substituted or unsubstituted C1-C20 alkyl group; each X is independently a hydroxyl group or a hydrolyzable group; and b is an integer from 1 to 3.)

2. The curable composition according to claim 1, characterized in that component (A) has an average of 1.1 or more silicon-containing reactive groups per molecule.

3. R １ ~R ６ The curable composition according to claim 1 or 2, characterized in that each of them is independently an alkyl group having 1 to 6 carbon atoms.

4. R １ ~R ６ The curable composition according to claim 3, characterized in that each of the groups is independently a methyl group, an ethyl group, and / or a propyl group, and m is an integer from 2 to 4.

5. The curable composition according to claim 3, characterized in that the component (C) is one or more selected from tetramethylguanidinepropyltrimethoxysilane, tetramethylguanidinepropylmethyldimethoxysilane, tetramethylguanidinepropyldimethylmethoxysilane, and tetramethylguanidinepropyltriethoxysilane.

6. The curable composition further optionally contains component (D), which is a (meth)acrylic acid ester polymer having silicon-containing reactive groups other than trialkoxysilyl groups. The curable composition according to claim 1, characterized in that the content of component (B) is 18% or more of the total mass of component (A), component (B), and component (D).

7. A cured product obtained by curing the curable composition according to any one of claims 1 to 6.

8. An adhesive comprising the curable composition according to any one of claims 1 to 6.

9. A sealing material comprising the curable composition according to any one of claims 1 to 6.

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