Curable composition and its cured product

Abstract

To provide a curable composition which contains a polyoxyalkylene-based polymer having a reactive silyl group and can give a cured product with high strength.SOLUTION: The curable composition contains: a polyoxyalkylene-based polymer (A) having a reactive silyl group; and an organopolysiloxane (B). (B) has a T3 ratio represented by [T3 / (Q1+Q2+Q3+Q4+T1+T2+T3+D1+D2+M1)]×100 of 20% or more and 45% or less. Q1, Q2, Q3 or Q4 represents a constituent unit derived from a tetraalkoxysilane and having one, two, three or four siloxane bonds; T1, T2 or T3 represents a constituent unit derived from a monoorganotrialkoxysilane and having one, two or three siloxane bonds; D1 or D2 represents a constituent unit derived from a diorganodialkoxysilane and having one or two siloxane bonds; and M1 represents a constituent unit derived from a triorganomonoalkoxysilane and having one siloxane bond.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable composition comprising a polymer having a reactive silyl group, a cured product thereof, and a method for producing the composition. [Background technology]

[0002] Organic polymers having silicon-containing groups (hereinafter referred to as "reactive silyl groups") that have hydroxyl groups or hydrolyzable groups on silicon atoms and can form siloxane bonds are known as moisture-reactive polymers and are included in many industrial products such as adhesives, sealants, coatings, paints, and sealants, and are used in a wide range of fields. Among such reactive silyl group-containing polymers, those with a polyoxyalkylene polymer as the main chain skeleton are widely used.

[0003] A known technique involves compounding a silicone resin with an organic polymer containing such reactive silyl groups to improve the mechanical properties that develop after curing. A silicone resin is a polymer in which the main chain consists of siloxane bonds in an inorganic skeleton and organic groups such as methyl or phenyl groups in the side chains. This resin can be produced by the hydrolysis and dehydration condensation reaction of organoalkoxysilanes.

[0004] One type of such silicone resin is polysilsesquioxane, which is synthesized from trifunctional organotrialkoxysilanes. For example, Patent Document 1 discloses a crosslinked composition containing a polymer having a reactive silyl group and a silicone resin containing silsesquioxane units. Patent Document 2 also discloses a composition containing silsesquioxane containing a phenyl group and an alkoxy group, a silylated polymer containing an alkoxysilane group, and a carbonate filler. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Special Table 2014-521819 Gazette

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] [End]]The polyoxyalkylene polymer having a reactive silyl group cures to form a cured product, but there is room for improvement in the strength exhibited by the cured product.

[0007] In view of the above situation, an object of the present invention is to provide a curable composition containing a polyoxyalkylene polymer having a reactive silyl group and capable of providing a cured product with high strength.

Means for Solving the Problems

[0008] As a result of intensive studies by the present inventors to solve the above problems, it has been found that the strength after curing can be improved by blending a silicone resin having specific structural units in a specific ratio with a polyoxyalkylene polymer having a reactive silyl group, and the present invention has been achieved.

[0009] That is, the present invention is a curable composition containing a polyoxyalkylene polymer (A) having a reactive silyl group and an organopolysiloxane (B), The organopolysiloxane (B) has a T3 ratio represented by the formula: [T3 / (Q1+Q2+Q3+Q4+T1+T2+T3+D1+D2+M1)]×100 of 20% or more and 45% or less (In the formula, Q1, Q2, Q3, or Q4 each refers to a structural unit derived from tetraalkoxysilane and forming 1, 2, 3, or 4 siloxane bonds, [End]]T1, T2, or T3 each refers to a structural unit derived from monoorganotrialkoxysilane and forming 1, 2, or 3 siloxane bonds, D1 or D2 each refers to a structural unit derived from an organodialkoxysilane and forming one or two siloxane bonds. M1 refers to a structural unit derived from a triorganomonoalkoxysilane and forming one siloxane bond, and relates to a curable composition. The present invention also relates to a cured product obtained by curing the curable composition. Furthermore, the present invention is a method for producing the curable composition, a step of mixing the polyoxyalkylene-based polymer (A) having the reactive silyl group and the organopolysiloxane (B) in a solvent, and a step of distilling off the solvent, and also relates to the production method.

Effects of the Invention

[0010] According to the present invention, it is possible to provide a curable composition containing a polyoxyalkylene-based polymer having a reactive silyl group and capable of giving a high-strength cured product.

Modes for Carrying Out the Invention

[0011] The embodiments of the present invention will be specifically described below. The curable composition according to the present disclosure contains at least a polyoxyalkylene-based polymer (A) having a reactive silyl group and an organopolysiloxane (B).

[0012] <<Polyoxyalkylene-based Polymer (A) Containing Reactive Silyl Group>> The polyoxyalkylene-based polymer (A) containing a reactive silyl group has a polymer skeleton composed of a plurality of repeating units and a terminal structure bonded to the end of the polymer skeleton. The polymer skeleton refers to the polymer main chain composed of a plurality of repeating units. The polymer skeleton of the polymer (A) may be linear or branched.

[0013] The polymer skeleton is preferably composed only of a plurality of linked repeating units, or a polymer skeleton composed only of the plurality of repeating units and a structure derived from the initiator used during polymerization. The repeating units refer to oxyalkylene units, for example, oxyalkylene units having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms.

[0014] The term "terminal structure" refers to a region that does not contain repeating units constituting the polymer skeleton and is bonded to the end of the polymer skeleton. Preferably, the terminal structure is bonded to an oxyalkylene unit located at the end of the polymer skeleton via an oxygen atom. Furthermore, it is preferable that the reactive silyl group present in polymer (A) is included in the terminal structure. In this case, each terminal structure may contain a reactive silyl group, or terminal structures containing reactive silyl groups and terminal structures not containing reactive silyl groups may coexist.

[0015] <Reactive silyl group> Polyoxyalkylene polymer (A) has a reactive silyl group. This reactive silyl group is a silicon-containing group that has a hydroxyl group or a hydrolyzable group on a silicon atom and can form a siloxane bond through hydrolysis and dehydration condensation reactions, and can specifically be represented by the following general formula (1). -Si(R 1 ) 3-a (X) a (1) In formula (1), R 1 Each of these independently represents a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may have a hetero-containing group. Each of these independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3.

[0016] R 1 This is a hydrocarbon group having 1 to 20 carbon atoms. The number of carbon atoms is preferably 1 to 12, more preferably 1 to 6, and particularly preferably 1 to 4. The hydrocarbon group may be an unsubstituted hydrocarbon group or a hydrocarbon group having substituents.

[0017] R 1 A hetero-containing group that a hydrocarbon group may have as a substituent is a group containing a heteroatom. Here, atoms other than carbon atoms and hydrogen atoms are defined as heteroatoms.

[0018] Suitable examples of heteroatoms include N, O, S, P, Si, and halogen atoms. For hetero-containing groups, the sum of the number of carbon atoms and the number of heteroatoms is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4.

[0019] Preferred examples of hetero-containing groups include hydroxyl groups; mercapto groups; halogen atoms such as Cl, Br, I, and F; nitro groups; cyano groups; alkoxy groups such as methoxy, ethoxy, n-propyloxy, and isopropyloxy groups; alkylthio groups such as methylthio, ethylthio, n-propylthio, and isopropylthio groups; acyl groups such as acetyl, propionyl, and butanoyl groups; acyloxy groups such as acetyloxy, propionyloxy, and butanoyloxy groups; substituted or unsubstituted amino groups such as amino groups, methylamino, ethylamino, dimethylamino, and diethylamino groups; substituted or unsubstituted aminocarbonyl groups such as aminocarbonyl, methylaminocarbonyl, ethylaminocarbonyl, dimethylaminocarbonyl, and diethylaminocarbonyl groups; and cyano groups.

[0020] R 1Specific examples of the hydrocarbon group having 1 to 20 carbon atoms as R include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethyl-n-hexyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-octadecyl group, n-nonadecyl group, n-icosyl group; alkenyl groups such as vinyl group, 2-propenyl group, 3-butenyl group, 4-pentenyl group; cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; aryl groups such as phenyl group, naphthalene-1-yl group, naphthalene-2-yl group, o-phenylphenyl group, m-phenylphenyl group, p-phenylphenyl group; aralkyl groups such as benzyl group, phenethyl group, naphthalene-1-ylmethyl group, naphthalene-2-ylmethyl group. Groups in which these hydrocarbon groups are substituted with the above-mentioned hetero atom-containing groups are also preferred as R 1 are preferred.

[0021] R 1 Preferred examples of R include, for example, alkyl groups such as methyl group and ethyl group; alkyl groups having a hetero atom-containing group such as chloromethyl group and methoxymethyl group; cycloalkyl groups such as cyclohexyl group; aryl groups such as phenyl group; aralkyl groups such as benzyl group; and the like. R 1 is preferably a methyl group, a methoxymethyl group, or a chloromethyl group, more preferably a methyl group or a methoxymethyl group, and even more preferably a methyl group.

[0022] Examples of X include, for example, a hydroxyl group, hydrogen, halogen, 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, an alkoxy group is preferred, and a methoxy group and an ethoxy group are more preferred, because of their mild hydrolyzability and easy handling.

[0023] a is 1, 2, or 3. 2 or 3 is preferred for a.

[0024] Specific examples of the reactive silyl group include, but are not limited to, trimethoxysilyl, triethoxysilyl, tris(2-propenyloxy)silyl, triacetoxysilyl, dimethoxymethylsilyl, diethoxymethylsilyl, dimethoxyethylsilyl, (chloromethyl)dimethoxysilyl, (chloromethyl)diethoxysilyl, (methoxymethyl)dimethoxysilyl, (methoxymethyl)diethoxysilyl, (N,N-diethylaminomethyl)dimethoxysilyl, and (N,N-diethylaminomethyl)diethoxysilyl. Among these, dimethoxymethylsilyl, trimethoxysilyl, triethoxysilyl, and (methoxymethyl)dimethoxysilyl are preferred because they yield cured products with good mechanical properties. From the viewpoint of activity, trimethoxysilyl group, (chloromethyl)dimethoxysilyl group, and (methoxymethyl)dimethoxysilyl group are more preferred, and trimethoxysilyl group and (methoxymethyl)dimethoxysilyl group are particularly preferred. From the viewpoint of stability, dimethoxymethylsilyl group and triethoxysilyl group are more preferred, and dimethoxymethylsilyl group is particularly preferred.

[0025] The average number of reactive silyl groups per molecule of polyoxyalkylene polymer (A) is preferably greater than 1.0, more preferably 1.3 or more, and even more preferably 1.6 or more. In particular, due to the excellent effect of improving the strength of the cured product by incorporating organopolysiloxane (B), the average number of reactive silyl groups per molecule of polymer (A) is preferably 2.0 or more, more preferably 2.2 or more, and particularly preferably 2.5 or more. Furthermore, there is no particular upper limit to the average number, but it is preferably 6 or less, and more preferably 5 or less. The average number of reactive silyl groups per molecule of polymer (A) can be calculated from the results of NMR measurement.

[0026] Furthermore, the average ratio of the number of reactive silyl groups to the number of terminals in the polymer backbone in one molecule of polyoxyalkylene polymer (A) is not particularly limited and may be 1.0 or less, or greater than 1.0. The upper limit of the average ratio is also not particularly limited, but is preferably 5 or less, and more preferably 3 or less. The numerical value of the average ratio can be calculated from the results of NMR measurement.

[0027] In this specification, the average ratio of the number of reactive silyl groups to the number of terminals of the polymer skeleton refers to the average number of reactive silyl groups contained per terminal structure of the polymer skeleton, and is expressed as average number of reactive silyl groups in one polymer molecule / number of terminals of the polymer skeleton in one polymer molecule. The number of terminals of the polymer skeleton in one polymer molecule is 2 if the polymer skeleton is entirely linear, and 3 or more if the polymer skeleton is entirely branched. Furthermore, if the polymer skeleton is a mixture of linear and branched structures, it may be between 2 and 3.

[0028] In polyoxyalkylene polymers (A), the terminal structures having reactive silyl groups are not particularly limited, but typical examples include terminal structures represented by the following general formulas (2) or (3).

[0029] -OR 6 -CH(R 7 )-CH2-Si(R 1 ) 3-a (X) a (2) In formula (2), R 6 R represents a direct bond or a divalent hydrocarbon group having 1 to 4 carbon atoms. 7 R represents hydrogen or an alkyl group having 1 to 6 carbon atoms. The oxygen at the leftmost end indicates oxygen in a repeating unit located at the end of the polymer backbone, or oxygen bonded to a repeating unit located at the end of the polymer backbone. 1 X and a are the same as those described above for equation (1).

[0030] R 6Preferably, the hydrocarbon group is a divalent hydrocarbon group having 1 to 3 carbon atoms, and more preferably a divalent hydrocarbon group having 1 to 2 carbon atoms. The hydrocarbon group is preferably an alkylene group, and methylene, ethylene, propylene, or butylene groups can be used. Methylene is particularly preferred.

[0031] R 7 Preferably, the alkyl group is hydrogen or an alkyl group having 1 to 4 carbon atoms, and more preferably, hydrogen or an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and the like. 7 Hydrogen, methyl groups, and ethyl groups are preferred, with hydrogen and methyl groups being more preferred.

[0032] [ka]

[0033] In formula (3), R 8 R represents a direct bond or a divalent bonding group with 1 to 6 carbon atoms. 9 R represents hydrogen or a hydrocarbon group having 1 to 10 carbon atoms. n is an integer from 1 to 10. The oxygen at the leftmost end indicates oxygen in a repeating unit located at the end of the polymer backbone, or oxygen bonded to a repeating unit located at the end of the polymer backbone. 1 , R 6 , R 7 X and a are the same as those described above for equations (1) and (2).

[0034] R 8 This may be a divalent organic group having 1 to 6 carbon atoms. The organic group is preferably a hydrocarbon group or a hydrocarbon group containing an oxygen atom. The number of carbon atoms is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 to 2. 8 The preferred members are -CH2OCH2-, -CH2O-, and -CH2-, with -CH2OCH2- being more preferred.

[0035] R 9Preferably, the group is hydrogen or a hydrocarbon group having 1 to 5 carbon atoms, more preferably hydrogen or a hydrocarbon group having 1 to 3 carbon atoms, and even more preferably hydrogen or a hydrocarbon group having 1 to 2 carbon atoms. Particularly preferred are a hydrogen atom and a methyl group, and most preferably a hydrogen atom.

[0036] <polymer skeleton> Examples of polymer skeletons for polyoxyalkylene polymers (A) include polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymers, and polyoxypropylene-polyoxybutylene copolymers. Each polymer may be mixed in block form, graft form, etc. Among these, polyoxypropylene is particularly preferred. Polyoxyalkylene polymers (A) preferably contain 50% by weight or more of the polyoxyalkylene repeating units in their polymer skeleton, and more preferably 70% by weight or more.

[0037] The polyoxyalkylene polymer (A) may be a polymer having any one polymer skeleton, or a mixture of two or more polymers having different polymer skeletons. Furthermore, the mixture may be a mixture of polymers manufactured separately, or a mixture manufactured simultaneously to achieve any desired mixed composition.

[0038] The number-average molecular weight of the polyoxyalkylene polymer (A) is not particularly limited, but is preferably 3,000 to 100,000, more preferably 3,000 to 50,000, and particularly preferably 3,000 to 30,000 as the polystyrene-equivalent molecular weight in GPC. When the number-average molecular weight is within the above range, the amount of reactive silyl groups introduced is appropriate, making it possible to relatively easily produce a polyoxyalkylene polymer (A) with a manageable viscosity and excellent workability while keeping manufacturing costs within a reasonable range. In particular, since a cured product exhibiting high strength can be obtained, the number-average molecular weight of the polyoxyalkylene polymer (A) is preferably 7,000 or more, more preferably 10,000 or more, and even more preferably 12,000 or more.

[0039] The molecular weight of polyoxyalkylene polymer (A) can also be expressed as the end-group-reduced molecular weight, which is determined by directly measuring the end-group concentration of the polymer precursor before the introduction of reactive silyl groups using titration analysis based on the principles of the hydroxyl value measurement method specified in JIS K 1557 and the iodine value measurement method specified in JIS K 0070, and considering the structure of the polymer (degree of branching determined by the polymerization initiator used). Alternatively, the end-group-reduced molecular weight of polyoxyalkylene polymer (A) can be determined by creating a calibration curve between the number-average molecular weight obtained by general GPC measurement of the polymer precursor and the above-mentioned end-group-reduced molecular weight, and then converting the number-average molecular weight obtained by GPC of polyoxyalkylene polymer (A) to the end-group-reduced molecular weight.

[0040] The molecular weight distribution (Mw / Mn) of the polyoxyalkylene polymer (A) is not particularly limited, but a narrow range is preferred. Specifically, it is preferably less than 2.0, more preferably 1.6 or less, even more preferably 1.5 or less, particularly preferably 1.4 or less, even more preferably 1.3 or less, and most particularly preferably 1.2 or less. The molecular weight distribution of the polyoxyalkylene polymer (A) can be determined from the number-average molecular weight and weight-average molecular weight obtained by GPC measurement.

[0041] <Method for producing a reactive silyl group-containing polyoxyalkylene polymer (A)> Next, a method for producing a reactive silyl group-containing polyoxyalkylene polymer (A) will be described. A reactive silyl group-containing polyoxyalkylene polymer (A) can be produced by introducing a reactive silyl group into a precursor polymer that is capable of introducing a reactive silyl group. Specifically, a polyoxyalkylene polymer (A) can be produced by first introducing a carbon-carbon unsaturated bond into a polyoxyalkylene polymer (P) having a hydroxyl group at its terminal, utilizing the reactivity of the hydroxyl group to obtain a precursor polymer having a carbon-carbon unsaturated bond, and then reacting the precursor polymer with a reactive silyl group-containing compound that is reactive with the carbon-carbon unsaturated bond to introduce a reactive silyl group.

[0042] (polymerization) The polymer skeleton of polyoxyalkylene polymers can be formed by polymerizing an epoxy compound onto a hydroxyl group-containing initiator using conventionally known methods, thereby obtaining a polyoxyalkylene polymer (P) with hydroxyl groups at its ends. While there are no particular limitations on the specific polymerization method, polymerization methods using complex metal cyanide catalysts such as zinc hexacyanocobaltate glyme complexes are preferred because they yield hydroxyl group-terminated polymers with a small molecular weight distribution (Mw / Mn).

[0043] The initiator having a hydroxyl group is not particularly limited, but examples include ethylene glycol, propylene glycol, glycerin, pentaerythritol, low molecular weight polyoxypropylene glycol, low molecular weight polyoxypropylene triol, butanol, allyl alcohol, low molecular weight polyoxypropylene monoallyl ether, and low molecular weight polyoxypropylene monoalkyl ether.

[0044] The epoxy compound is not particularly limited, but examples include alkylene oxides such as ethylene oxide and propylene oxide, and glycidyl ethers such as methyl glycidyl ether and butyl glycidyl ether. Propylene oxide is preferred.

[0045] (Reaction with alkali metal salts) In introducing carbon-carbon unsaturated bonds to a polyoxyalkylene polymer (P) having hydroxyl groups at its terminals, it is preferable to first react the polyoxyalkylene polymer (P) with an alkali metal salt to convert the terminal hydroxyl groups into metal-oxy groups. Alternatively, a complex metal cyanide catalyst can be used instead of an alkali metal salt. Through these steps, a metal-oxy group-terminated polyoxyalkylene polymer (D) is formed.

[0046] The alkali metal salt is not particularly limited, but examples include sodium hydroxide, sodium alkoxide, potassium hydroxide, potassium alkoxide, lithium hydroxide, lithium alkoxide, cesium hydroxide, cesium alkoxide, and the like. The alkali metal salt may be used in the reaction in a dissolved state in the solvent.

[0047] (Reaction with electrophile (E)) Next, by reacting a metal-oxy group-terminated polyoxyalkylene polymer (D) with an electrophile (E) having a carbon-carbon unsaturated bond, the metal-oxy group can be converted into a structure containing a carbon-carbon unsaturated bond. This results in the formation of a polyoxyalkylene polymer (F) having a carbon-carbon unsaturated bond in its terminal structure.

[0048] The electrophile (E) having a carbon-carbon unsaturated bond is not particularly limited as long as it is a compound that can react with the metaloxy group of the polyoxyalkylene polymer (D) and introduce a carbon-carbon unsaturated bond into the polyoxyalkylene polymer. Examples include organic halides (E1) having a carbon-carbon unsaturated bond and epoxy compounds (E2) having a carbon-carbon unsaturated bond.

[0049] The organic halide (E1) having a carbon-carbon unsaturated bond can react with the metaloxy group through a halogen substitution reaction to form an ether bond, thereby introducing a structure containing a carbon-carbon unsaturated bond as the terminal structure of a polyoxyalkylene polymer.

[0050] The organic halide (E1) having a carbon-carbon unsaturated bond is preferably a halogenated hydrocarbon compound having a carbon-carbon double bond. The polyoxyalkylene polymer (G) obtained by reacting this compound has a carbon-carbon double bond at the terminal end of the polymer backbone. The halogenated hydrocarbon compound having a carbon-carbon double bond is not limited, but can be represented by the following general formula (7). ZR 6 -C(R 7 )=CH2(7)

[0051] In formula (7), R 6 and R 7 These are the R values ​​mentioned above for general formula (2), respectively. 6 and R 7 It is the same group as above. Z represents a halogen atom. When a reactive silyl group, which will be explained later, is introduced into a polyoxyalkylene polymer (F) having a carbon-carbon unsaturated bond in its terminal structure, obtained by reacting the organic halide (E1), the terminal structure represented by the general formula (2) above can be formed.

[0052] Specific examples of halogenated hydrocarbon compounds having carbon-carbon double bonds include, but are not limited to, vinyl chloride, allyl chloride, methallyl chloride, vinyl bromide, allyl bromide, methallyl bromide, vinyl iodide, allyl iodide, and methallyl iodide. Allyl chloride and methallyl chloride are preferred due to their ease of handling. Furthermore, methallyl chloride, methallyl bromide, and methallyl iodide are preferred because they improve the average ratio of the number of reactive silyl groups to the number of terminals in the polymer skeleton.

[0053] The epoxy compound (E2) having a carbon-carbon unsaturated bond reacts with the metaloxy group by a ring-opening addition reaction of the epoxy group to form an ether bond, thereby introducing a structure containing a carbon-carbon unsaturated bond and a hydroxyl group as the terminal structure of the polyoxyalkylene polymer. In the ring-opening addition reaction, by adjusting the amount of epoxy compound (E2) used relative to the metaloxy group and the reaction conditions, one or more epoxy compounds (E2) can be added to a single metaloxy group.

[0054] The epoxy compound (E2) having a carbon-carbon unsaturated bond is not limited to, but an epoxy compound having a carbon-carbon double bond is preferred and can be represented by the following general formula (8).

[0055] [ka]

[0056] In formula (8), R 8 and R 9 These are the R values ​​mentioned above for general formula (3), respectively. 8 and R 9 It is the same base as [the other].

[0057] Specific examples of epoxy compounds (E2) having carbon-carbon unsaturated bonds are not particularly limited, but allyl glycidyl ether, methallyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, and butadiene monooxide are preferred from the viewpoint of reaction activity, with allyl glycidyl ether being particularly preferred.

[0058] As described above, when an epoxy compound (E2) having a carbon-carbon unsaturated bond is reacted with a metaloxy group-terminated polyoxyalkylene polymer (D), a new metaloxy group is generated by ring-opening of the epoxy group. Therefore, after reacting with the epoxy compound (E2), an organic halide (E1) having a carbon-carbon unsaturated bond can be reacted consecutively. This method is preferable because it can further increase the amount of carbon-carbon unsaturated bond introduced into the polymer and the amount of reactive silyl group introduced. When a reactive silyl group, as described below, is introduced into a polyoxyalkylene polymer (F) having a carbon-carbon unsaturated bond in its terminal structure, obtained by the method using both the epoxy compound (E2) and the organic halide (E1), the terminal structure represented by the general formula (3) can be formed.

[0059] (Introduction of reactive silyl groups) By hydrosilylation reacting a polyoxyalkylene polymer (F) (precursor polymer) having carbon-carbon unsaturated bonds in its terminal structure with a hydrosilane compound (G) having a reactive silyl group, a reactive silyl group can be introduced into the polymer. This allows for the production of a reactive silyl group-containing polyoxyalkylene polymer (A). The hydrosilylation reaction has the advantages of being easy to carry out, allowing for easy adjustment of the amount of reactive silyl group introduced, and resulting in a polymer with stable physical properties.

[0060] Specific examples of the hydrosilane compound (G) having the reactive silyl group include halosilanes such as trichlorosilane, dichloromethylsilane, chlorodimethylsilane, dichlorophenylsilane, (chloromethyl)dichlorosilane, (dichloromethyl)dichlorosilane, bis(chloromethyl)chlorosilane, (methoxymethyl)dichlorosilane, (dimethoxymethyl)dichlorosilane, and bis(methoxymethyl)chlorosilane; trimethoxysilane, triethoxysilane, dimethoxymethylsilane, diethoxymethyl Lusilane, dimethoxyphenylsilane, ethyldimethoxysilane, methoxydimethylsilane, ethoxydimethylsilane, (chloromethyl)methylmethoxysilane, (chloromethyl)dimethoxysilane, (chloromethyl)diethoxysilane, bis(chloromethyl)methoxysilane, (methoxymethyl)methylmethoxysilane, (methoxymethyl)dimethoxysilane, bis(methoxymethyl)methoxysilane, (methoxymethyl)diethoxysilane, (ethoxymethyl)diethoxysilane, (3,3,3-triph (Oropropyl)dimethoxysilane, (N,N-diethylaminomethyl)dimethoxysilane, (N,N-diethylaminomethyl)diethoxysilane, [(chloromethyl)dimethoxysilyloxy]dimethylsilane, [(chloromethyl)diethoxysilyloxy]dimethylsilane, [(methoxymethyl)dimethoxysilyloxy]dimethylsilane, [(methoxymethyl)diethoxysilyloxy]dimethylsilane, [(diethylaminomethyl)dimethoxysilyloxy]dimethylsilane, [(3,3,3-tri Examples include alkoxysilanes such as [fluoropropyl]dimethoxysilyloxy]dimethylsilane; acyloxysilanes such as diacetoxymethylsilane and diacetoxyphenylsilane; ketoximate silanes such as bis(dimethylketoximate)methylsilane and bis(cyclohexylketoximate)methylsilane; isopropenyloxysilanes (deacetone-free type) such as triisopropenyloxysilane, (chloromethyl)diisopropenyloxysilane, and (methoxymethyl)diisopropenyloxysilane.

[0061] Hydrosilylation reactions are preferably carried out in the presence of a hydrosilylation catalyst to accelerate the reaction. Known hydrosilylation catalysts include metals such as cobalt, nickel, iridium, platinum, palladium, rhodium, and ruthenium, as well as complexes thereof, and these can be used. Specifically, examples include platinum supported on a carrier such as alumina, silica, or carbon black; chloroplatinic acid; chloroplatinic acid complexes consisting of chloroplatinic acid with alcohols, aldehydes, or ketones; platinum-olefin complexes [e.g., Pt(CH2=CH2)2(PPh3), Pt(CH2=CH2)2Cl2]; platinum-vinylsiloxane complexes [e.g., Pt{(vinyl)Me2SiOSiMe2(vinyl)}, Pt{Me(vinyl)SiO}4]; platinum-phosphine complexes [e.g., Ph(PPh3)4, Pt(PBu3)4]; and platinum-phosphine complexes [e.g., Pt{P(OPh)3}4]. From the viewpoint of reaction efficiency, platinum catalysts such as chloroplatinic acid and platinum-vinylsiloxane complexes are preferred.

[0062] <<Organopolysiloxane (B)>> Organopolysiloxane (B) is a polymer in which the main chain is composed of siloxane bonds and the side chains have organic groups such as methyl groups and phenyl groups. Organopolysiloxane (B) is a hydrolysis condensate of an alkoxysilane component containing at least a monoorganotrialkoxysilane.

[0063] The aforementioned monoorganotrialkoxysilane refers to a silane compound having one organic group directly bonded to a silicon atom and three alkoxy groups directly bonded to a silicon atom, and is represented by the formula RSi(OR')3. In the formula, R represents the aforementioned organic group, and OR' represents the alkoxy group. The aforementioned organic group refers to any organic group other than an alkoxy group.

[0064] The alkoxy group (OR') directly bonded to the silicon atom is not particularly limited, but is preferably an alkoxy group having 1 to 3 carbon atoms. Specifically, examples include a methoxy group, an ethoxy group, and a propoxy group, with methoxy and ethoxy groups being preferred, and methoxy groups being more preferred. The alkoxy group may be just one type, or two or more types may be mixed together.

[0065] The organic group directly bonded to the silicon atom is not particularly limited, but is preferably a substituted or unsubstituted hydrocarbon group, for example, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms.

[0066] Examples of C1-C10 alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, and decyl groups. The number of carbon atoms in the alkyl group is preferably 1-4, more preferably 1-3, even more preferably 1-2, and particularly preferably 1. The alkyl group may be unsubstituted, or it may have a halogen atom, an alkoxy group, an acyl group, or other hetero-containing group as a substituent. The alkyl group may be of a single type, or two or more types may be used in combination.

[0067] Examples of the aryl group having 6 to 12 carbon atoms include phenyl, tolyl, xylyl, and naphthyl groups. The number of carbon atoms in the aryl group is preferably 6 to 10, more preferably 6 to 8, even more preferably 6 to 7, and particularly preferably 6. The aryl group may be unsubstituted, or it may have a hetero-containing group such as a halogen atom, alkoxy group, or acyl group as a substituent. The aryl group may be of only one type, or two or more types may be used in combination.

[0068] Specific examples of monoorganotrialkoxysilanes in which the organic group is an alkyl group are not particularly limited, but include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltriisopropoxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltriisopropoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, pentyltriisopropoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, etc. Among these, methyltrialkoxysilane is preferred, and methyltrimethoxysilane is particularly preferred.

[0069] The specific examples of monoorganotrialkoxysilanes in which the organic group is an aryl group are not particularly limited, but include phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, tolyltrimethoxysilane, tolyltriethoxysilane, tolyltripropoxysilane, xyltrimethoxysilane, xyltriethoxysilane, xyltripropoxysilane, naphthyltrimethoxysilane, naphthyltriethoxysilane, naphthyltripropoxysilane, and the like. Among these, phenyltrialkoxysilane is preferred, and phenyltrimethoxysilane is particularly preferred.

[0070] From the viewpoint of improving the compatibility between the polyoxyalkylene polymer (A) and the organopolysiloxane (B) and further improving the strength of the cured product obtained by curing the curable composition, it is preferable to use a monoorganotrialkoxysilane in combination with a monoorganotrialkoxysilane in which the organic group is an alkyl group and a monoorganotrialkoxysilane in which the organic group is an aryl group as the monoorganotrialkoxysilane.

[0071] The alkoxysilane component may contain only monoorganotrialalkoxysilane, or it may further contain, in addition to monoorganotrialalkoxysilane, at least one selected from the group consisting of tetraalkoxysilane, diorganodialkoxysilane, and triorganomonoalkoxysilane.

[0072] The tetraalkoxysilane refers to a silane compound having four alkoxy groups directly bonded to a silicon atom. The diorganodialkoxysilane refers to a silane compound having two organic groups directly bonded to a silicon atom and two alkoxy groups directly bonded to a silicon atom. The triorganomonoalkoxysilane refers to a silane compound having three organic groups directly bonded to a silicon atom and one alkoxy group directly bonded to a silicon atom.

[0073] The alkoxysilane component preferably contains the monoorganotrialalkoxysilane as its main component. Specifically, the proportion of the monoorganotrialalkoxysilane in the alkoxysilane component is preferably 80 to 100 mol%, more preferably 90 to 100 mol%, even more preferably 95 to 100 mol%, and particularly preferably 99 to 100 mol%.

[0074] In organopolysiloxane (B), the ratio of the constituent unit T3, which originates from monoorganotrialkoxysilane and forms three siloxane bonds, to the sum of all constituent units (i.e., the sum of Q1, Q2, Q3, Q4, T1, T2, T3, D1, D2, and M1): [T3 / (Q1+Q2+Q3+Q4+T1+T2+T3+D1+D2+M1)]×100 is within a specific range.

[0075] Here, we define the constituent units derived from tetraalkoxysilane as follows: a constituent unit forming one siloxane bond is Q1, a constituent unit forming two siloxane bonds is Q2, a constituent unit forming three siloxane bonds is Q3, and a constituent unit forming four siloxane bonds is Q4. A constituent unit derived from a monoorganotrialkoxysilane is defined as follows: a constituent unit forming one siloxane bond is defined as T1, a constituent unit forming two siloxane bonds is defined as T2, and a constituent unit forming three siloxane bonds is defined as T3. A structural unit derived from a diorganodialkoxysilane is defined as D1 if it forms one siloxane bond, and as D2 if it forms two siloxane bonds. We define M1 as a structural unit derived from a triorganomonalkoxysilane and forming one siloxane bond.

[0076] The ratio of T3 mentioned above is based on organopolysiloxane (B) 29 In the NMR chart obtained by measurement using Si-NMR, the peak area is calculated as the percentage of the peak area originating from T3 to the total peak area, based on the peak areas originating from Q1, Q2, Q3, Q4, T1, T2, T3, D1, D2, and M1, respectively.

[0077] The T3 ratio of organopolysiloxane (B) is within the range of 20% to 45%. If the T3 ratio is less than 20%, the effect of improving the strength of the cured product cannot be sufficiently obtained even when organopolysiloxane (B) is blended with polyoxyalkylene polymer (A). Furthermore, if the T3 ratio exceeds 45%, the curing reaction of the curable composition proceeds too quickly, or the viscosity of the curable composition becomes too high, making it difficult to handle. Preferably, the T3 ratio is between 25% and 40%.

[0078] The ratio of T3 can be controlled by adjusting the proportion of monoorganotrialalkoxysilane in the alkoxysilane component, the amount of water used in the hydrolysis and dehydration condensation reaction to form the organopolysiloxane, the type and amount of catalyst, the reaction temperature, and the amount of alcohol removed in the hydrolysis reaction.

[0079] Furthermore, for organopolysiloxane (B), the ratio of the sum of T1, T2, and T3 out of the total of all constituent units: [(T1+T2+T3) / (Q1+Q2+Q3+Q4+T1+T2+T3+D1+D2+M1)]×100 is preferably 80-100%, more preferably 90-100%, even more preferably 95-100%, and particularly preferably 99-100%. The sum of T1, T2, and T3 is the same as the ratio of T3 described above. 29 It can be calculated based on measurements using Si-NMR.

[0080] From the viewpoint of improving compatibility with the polyoxyalkylene polymer (A) and further improving the strength of the cured product obtained by curing the curable composition, it is preferable that the organopolysiloxane (B) has both an alkyl group having 1 to 10 carbon atoms (b1) and an aryl group having 6 to 12 carbon atoms (b2) as organic groups directly bonded to the silicon atom.

[0081] In this preferred embodiment, in organopolysiloxane (B), the molar ratio of the alkyl group (b1) directly bonded to the silicon atom to the aryl group (b2) directly bonded to the silicon atom is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, and even more preferably 30:70 to 70:30.

[0082] Furthermore, since the cured product obtained by curing the curable composition exhibits good elongation, the molar ratio of the alkyl group (b1) directly bonded to the silicon atom to the aryl group (b2) directly bonded to the silicon atom is preferably 10:90 to 70:30, more preferably 10:90 to 50:50, and even more preferably 10:90 to 40:60.

[0083] Preferably, the organopolysiloxane (B) further has alkoxysilyl groups and / or silanol groups. By having these alkoxysilyl groups and / or silanol groups, the organopolysiloxane (B), together with the polyoxyalkylene polymer (A), can exhibit curability by hydrolysis and dehydration condensation reactions.

[0084] The alkoxysilyl groups that the organopolysiloxane (B) may have are some alkoxy groups that were present in the alkoxysilane component used as a raw material and remained unreacted during the production of organopolysiloxane (B). These alkoxysilyl groups may be, for example, alkoxysilyl groups having 1 to 3 carbon atoms. Specifically, examples include methoxysilyl groups, ethoxysilyl groups, and propoxysilyl groups, with methoxysilyl groups and ethoxysilyl groups being preferred, and methoxysilyl groups being more preferred. There may be only one type of alkoxysilyl group, or two or more types may be mixed together.

[0085] The silanol groups (-SiOH) that the organopolysiloxane may have are formed when some of the alkoxysilane components used as raw materials undergo hydrolysis during the production of organopolysiloxane (B), and the dehydration condensation reaction does not proceed, meaning that they remain without forming siloxane bonds.

[0086] The number-average molecular weight of organopolysiloxane (B) is preferably 400 to 10,000, and more preferably 500 to 5,000. The number-average molecular weight of organopolysiloxane (B) can be measured by GPC.

[0087] (Manufacturing of organopolysiloxane (B)) Organopolysiloxane (B) can be produced by hydrolysis and dehydration condensation of an alkoxysilane component containing the monoorganotrialkoxysilane with water and, optionally, a condensation catalyst.

[0088] The hydrolysis and dehydration condensation reactions described above are preferably carried out with the addition of water. At this time, the T3 ratio and molecular weight of organopolysiloxane (B) can be controlled by adjusting the amount of water used. From this viewpoint, the amount of water used is preferably 30 mol% to 50 mol%, more preferably 32 mol% to 49 mol%, and even more preferably 35 mol% to 45 mol%, based on 100% of the total number of moles of alkoxy groups on silicon atoms contained in the alkoxysilane component.

[0089] The hydrolysis and dehydration condensation reactions described above are preferably carried out in the presence of a condensation catalyst to accelerate the reaction. Known condensation catalysts can be used. Specifically, basic catalysts, acidic catalysts, neutral salts, etc. Acidic catalysts and neutral salts are preferred as condensation catalysts, and neutral salts are more preferred, as they improve the storage stability of the resulting organopolysiloxane (B).

[0090] As an acidic catalyst, organic acids are preferred due to their compatibility with alkoxysilane components, and phosphate esters and carboxylic acids are more preferred. Specific examples of organic acids include ethyl acid phosphate, butyl acid phosphate, dibutyl pyrophosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, isotridecyl acid phosphate, dibutyl phosphate, bis(2-ethylhexyl) phosphate, formic acid, acetic acid, butyric acid, isobutyric acid, and the like.

[0091] Examples of basic catalysts include amine compounds such as N-ethylmorpholine, N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, Nt-butyldiethanolamine, triethylamine, n-butylamine, hexylamine, triethanolamine, diazabicycloundecene, and ammonia, as well as metal hydroxides such as sodium hydroxide and potassium hydroxide.

[0092] A neutral salt is a normal salt composed of a strong acid and a strong base. For example, a neutral salt is a salt composed of a combination of a cation selected from the group consisting of Group 1 element ions, Group 2 element ions, tetraalkylammonium ions, and guanidinium ions, and an anion selected from the group consisting of Group 17 element ions (excluding fluoride ions), sulfate ions, nitrate ions, and perchlorate ions. In particular, Group 17 element ions are preferred as anions because they are highly nucleophilic, and Group 1 element ions and Group 2 element ions are preferred as cations that are not bulky so as not to inhibit nucleophilic activity.

[0093] The specific compounds of the neutral salt are not particularly limited, but preferred examples include lithium chloride, sodium chloride, potassium chloride, rabidium chloride, cesium chloride, magnesium chloride, calcium chloride, strontium chloride, lithium bromide, sodium bromide, potassium bromide, rabidium bromide, cesium bromide, magnesium bromide, calcium bromide, strontium bromide, lithium iodide, sodium iodide, potassium iodide, rabidium iodide, cesium iodide, magnesium iodide, calcium iodide, and strontium iodide.

[0094] The amount of condensation catalyst added can be adjusted as appropriate, but for example, it may be around 50 ppm to 3% by weight relative to the alkoxysilane component. However, in order to improve the stability of organopolysiloxane (B), it is preferable to use as little condensation catalyst as possible, within the range in which the effect of shortening the reaction time by the condensation catalyst is achieved.

[0095] The reaction temperature during the hydrolysis and dehydration condensation steps can be appropriately set by those skilled in the art, but it is preferable to heat the reaction solution to a range of 50 to 110°C. The reaction time during the hydrolysis and dehydration condensation steps can also be appropriately set by those skilled in the art, but it may be, for example, 10 minutes to 12 hours.

[0096] The ratio of polyoxyalkylene polymer (A) to organopolysiloxane (B) in the curable composition according to this disclosure can be appropriately determined considering the curability of the composition and the strength of the resulting cured product. Because it exhibits excellent strength-improving effects after curing, the proportion of polyoxyalkylene polymer (A) in the total of polyoxyalkylene polymer (A) and organopolysiloxane (B) is preferably 60-99% by weight, more preferably 60-95% by weight, even more preferably 65-90% by weight, and particularly preferably 65-85% by weight.

[0097] After producing organopolysiloxane (B), a step may be taken to remove the alcohol generated by the hydrolysis of the alkoxysilane component during production. This step is preferably carried out after mixing the polyoxyalkylene polymer (A) and the organopolysiloxane (B) containing the alcohol. This makes it possible to obtain a mixture in which the polyoxyalkylene polymer (A) and organopolysiloxane (B) are uniformly mixed while reducing the content of volatile components such as alcohol. The alcohol removal step can be carried out by subjecting the mixture to vacuum distillation to remove the alcohol. The conditions for vacuum distillation can be appropriately set by those skilled in the art, but the temperature may be, for example, around 60 to 160°C.

[0098] <<Curing catalyst (C)>> The curable composition according to this disclosure preferably further contains a curing catalyst (C) for the purpose of promoting a reaction that hydrolyzes and dehydrates the reactive silyl groups of the polyoxyalkylene polymer (A), i.e., a curing reaction.

[0099] However, the curable composition relating to this disclosure may not contain the curing catalyst (C). In such a case, a person who obtains a curable composition that does not contain the curing catalyst (C), or a person who uses such a composition, can create a curable composition containing the curing catalyst (C) by appropriately blending or adding the curing catalyst (C) to the composition.

[0100] Conventional known curing catalysts (C) can be used, specifically organotin compounds, metal carboxylate salts, amine compounds, carboxylic acids, alkoxy metals, inorganic acids, etc.

[0101] Specific examples of organotin compounds include dibutyltin dilaurate, dibutyltin dioctanoate, dibutyltin bis(butyl maleate), dibutyltin diacetate, dibutyltin oxide, dibutyltin bis(acetylacetonate), reaction products of dibutyltin oxide and silicate compounds, reaction products of dibutyltin oxide and phthalate esters, dioctyltin diacetate, dioctyltin dilaurate, dioctyltin bis(ethyl maleate), dioctyltin bis(octyl maleate), dioctyltin bis(acetylacetonate), dioctyltin distearate, dioctyltin oxide, and reaction products of dioctyltin oxide and silicate compounds. Due to the growing environmental concerns in recent years, dioctyltin compounds are preferred.

[0102] Specific examples of metal carboxylate salts include tin carboxylate, bismuth carboxylate, titanium carboxylate, zirconium carboxylate, iron carboxylate, potassium carboxylate, calcium carboxylate, and cesium carboxylate. Various metals can be combined with the following carboxylic acids as carboxylate groups.

[0103] Specific examples of amine compounds include amines such as octylamine, 2-ethylhexylamine, laurylamine, and stearylamine; nitrogen-containing heterocyclic compounds such as pyridine, 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), and 1,5-diazabicyclo[4,3,0]nonene-5 (DBN); guanidines such as guanidine, phenylguanidine, and diphenylguanidine; biguanides such as butyl biguanide, 1-o-tolylbiguanide, and 1-phenylbiguanide; amino group-containing silane coupling agents; and ketimine compounds.

[0104] Specific examples of carboxylic acids include acetic acid, propionic acid, butyric acid, 2-ethylhexanoic acid, lauric acid, stearic acid, oleic acid, linoleic acid, neodecanoic acid, and versatic acid.

[0105] Specific examples of alkoxy metals include titanium compounds such as tetrabutyl titanate, titanium tetrakis (acetylacetonate), and diisopropoxytitanium bis (ethylacetoacetate), as well as aluminum compounds such as aluminum tris (acetylacetonate) and diisopropoxyaluminum ethylacetoacetate, and zirconium compounds such as zirconium tetrakis (acetylacetonate).

[0106] Other curing catalysts that can be used include fluorine anion-containing compounds, photoacid generators, and photobase generators.

[0107] As the curing catalyst (C), two or more different catalysts may be used in combination. For example, using the aforementioned amine compound with a carboxylic acid, or with an amine compound with an alkoxy metal, may improve reactivity.

[0108] As for the amount of curing catalyst (C), from the viewpoint of achieving both improved curing reaction speed and workability during curing, it is preferable that it be about 0.01 to 20 parts by weight, more preferably 0.1 to 15 parts by weight, and particularly preferably 0.1 to 10 parts by weight, per 100 parts by weight of the total of polyoxyalkylene polymer (A) and organopolysiloxane (B).

[0109] <<Curable composition>> The curable composition according to this disclosure may contain various additives as needed, in addition to a polyoxyalkylene polymer (A), an organopolysiloxane (B), and an optional curing catalyst (C). Examples of such additives include fillers, adhesion promoters, plasticizers, anti-sagging agents, antioxidants, light stabilizers, UV absorbers, property modifiers, compounds containing epoxy groups, photocurable substances, oxygen-curable substances, and organic resins other than the polyoxyalkylene polymer (A).

[0110] Furthermore, other additives not mentioned above may be added to the curable composition as needed for the purpose of adjusting the various physical properties of the curable composition or cured product. Examples of such other additives include, for example, tackifying resins, solvents, diluents, epoxy resins, surface modifiers, foaming agents, curing modifiers, flame retardants, silicates, radical inhibitors, metal deactivators, ozone degradation inhibitors, phosphorus-based peroxide decomposers, lubricants, pigments, and antifungal agents.

[0111] The curable composition according to this disclosure is a composition mainly comprising a polyoxyalkylene polymer (A) that can exhibit fluidity at room temperature, and is preferably composed of a composition that is substantially free of solvents. The curable composition according to this disclosure can exhibit fluidity at room temperature even if it is substantially free of solvents, is easy to handle before curing, and does not require the removal of solvents during or after curing.

[0112] Specifically, the solvent content in the curable composition according to this disclosure may be 15% by weight or less of the total amount of the curable composition. The solvent content is preferably 10% by weight or less, more preferably 5% by weight or less, and even more preferably 1% by weight or less. The aforementioned solvent refers to a component that is liquid at room temperature and capable of dissolving or dispersing the polyoxyalkylene polymer (A) and the organopolysiloxane (B). The aforementioned solvent may also be an alcohol generated by the hydrolysis of the alkoxysilane component during the production of the organopolysiloxane (B) as described above.

[0113] To produce the curable composition, the polyoxyalkylene polymer (A) and the organopolysiloxane (B) can be mixed by appropriate means. However, from the viewpoint of ease of mixing and uniformity, it is preferable to mix the polyoxyalkylene polymer (A) and the organopolysiloxane (B) in a solvent. After mixing, the solvent can be removed by distillation, thereby obtaining a curable composition with reduced solvent content while uniformly mixing the polyoxyalkylene polymer (A) and the organopolysiloxane (B). The method for removing the solvent by distillation is not particularly limited, and known methods can be applied. Furthermore, it is preferable to add and mix the curing catalyst (C) after the solvent has been removed by distillation.

[0114] The aforementioned curable composition can be prepared as a one-component type, where all components are pre-mixed, sealed, and stored, and then cured by moisture in the air after application. The one-component curable composition preferably contains substantially no water, with a water content of 5% by weight or less, and more preferably 1% by weight or less. From the viewpoint of workability, the one-component type is preferred.

[0115] Furthermore, a curing agent can be prepared by blending components such as a curing catalyst (C), filler, plasticizer, and water, and mixing the curing agent with a main component containing a polyoxyalkylene polymer (A) and organopolysiloxane (B) before use. The main component of the two-component type preferably contains substantially no water, preferably 5% by weight or less, and more preferably 1% by weight or less.

[0116] Furthermore, the curable composition may be a two-component type comprising agent A, which includes a polyoxyalkylene polymer (A), organopolysiloxane (B), and a curing catalyst (C), and agent B, which includes another curable resin, water, etc. Agent A preferably contains substantially no water, and the water content is preferably 5% by weight or less, and more preferably 1% by weight or less.

[0117] Prior to curing, the curable composition is shaped into a desired form by methods such as coating, casting, or filling. The coated, casting, or filling curable composition can be cured at room temperature, or it can be cured under heat. The heat curing conditions are not particularly limited, but a temperature of 60 to 220°C and a time of 1 to 120 minutes is preferred, and a temperature of 100 to 200°C and a time of 5 to 60 minutes is more preferred.

[0118] The curable composition according to this disclosure can be used as an adhesive, sealant, sealing material for sealing work in buildings, ships, automobiles, buses, roads, home appliances, etc., as well as a molding agent, paint, spray agent, etc. Furthermore, the cured product obtained by curing the curable composition can be suitably used as a waterproofing material, waterproof coating material, vibration damping material, vibration control material, soundproofing material, foaming material, etc.

[0119] The following sections list preferred embodiments of this disclosure, but the present invention is not limited to these sections. [Item 1] A curable composition containing a polyoxyalkylene polymer (A) having a reactive silyl group and an organopolysiloxane (B), The organopolysiloxane (B) has a T3 ratio expressed by the formula: [T3 / (Q1+Q2+Q3+Q4+T1+T2+T3+D1+D2+M1)]×100 which is between 20% and 45%. (In the formula, Q1, Q2, Q3, or Q4 each refer to a constituent unit derived from a tetraalkoxysilane and forming one, two, three, or four siloxane bonds, respectively.) T1, T2, or T3 refer to constituent units derived from monoorganotrialkoxysilanes, each forming one, two, or three siloxane bonds, respectively. D1 or D2, respectively, refers to a structural unit derived from a diorganodialkoxysilane, forming one or two siloxane bonds. M1 refers to a structural unit derived from a triorganomonalkoxysilane that forms one siloxane bond, and is a curable composition. [Item 2] The curable composition according to item 1, wherein the organopolysiloxane (B) has an alkyl group having 1 to 10 carbon atoms (b1) and an aryl group having 6 to 10 carbon atoms (b2) as organic groups directly bonded to a silicon atom. [Item 3] The curable composition according to item 1 or 2, wherein the proportion of the polyoxyalkylene polymer (A) in the total of the polyoxyalkylene polymer (A) and the organopolysiloxane (B) is 60 to 99% by weight. [Item 4] A curable composition according to any one of items 1 to 3, further containing a curing catalyst (C). [Item 5] The polyoxyalkylene polymer (A) is a curable composition according to any one of items 1 to 4, wherein the number average molecular weight is 10,000 or more. [Item 6] The curable composition according to any one of items 1 to 5, wherein the content of the solvent in the curable composition is 15% by weight or less based on the total amount of the curable composition. [Item 7] A cured product obtained by curing any of the curable compositions described in items 1 to 6. [Item 8] A method for producing a curable composition as described in any of items 1 to 7, A step of mixing the polyoxyalkylene polymer (A) having the reactive silyl group and the organopolysiloxane (B) in a solvent, and A manufacturing method comprising the step of distilling off the aforementioned solvent. [Item 9] The manufacturing method according to item 8, comprising the step of mixing a curing catalyst (C) after the step of distilling off the solvent. [Examples]

[0120] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0121] The number-average molecular weight and weight-average molecular weight in each synthesis example are GPC molecular weights measured under the following conditions. Liquid delivery system: Tosoh HLC-8420GPC Column: Tosoh TSKgel SuperH series Solvent: THF Molecular weight: Polystyrene equivalent Measurement temperature: 40℃

[0122] The end-group-reduced molecular weight in each synthesis example is determined by calculating the hydroxyl value according to the measurement method of JIS K 1557 and the iodine value according to the measurement method of JIS K 0070, taking into account the structure of the organic polymer (degree of branching determined by the polymerization initiator used).

[0123] The average number of silyl groups introduced into each polymer shown in each synthesis example was calculated by NMR measurement.

[0124] The T3 ratio of the polysiloxanes shown in each synthesis example was measured as follows. The constituent units derived from monoorganotrialkoxysilane are classified into three types: T1, which forms one siloxane bond; T2, which forms two siloxane bonds; and T3, which forms three siloxane bonds. Using a BRUKER AVANCE III HD500 with deuterated chloroform as the solvent, organopolysiloxanes are analyzed. 29 Si-NMR was measured, and the ratio of the peak area derived from the T3 structure to the sum of the peak areas derived from the T1, T2, and T3 structures was defined as the T3 ratio of the polysiloxane. Note that in each synthesis example, the constituent units Q1-4 derived from tetraalkoxysilane, D1-D2 derived from diorganodialkoxysilane, and M1 derived from triorganomonoalkoxysilane are not included, and the ratio of these constituent units is 0.

[0125] (Synthesis Example 1) Using polyoxypropylene glycol with a number-average molecular weight of approximately 2,000 as an initiator, propylene oxide was polymerized with a zinc hexacyanocobaltate-grime complex catalyst to obtain polypropylene oxide with a number-average molecular weight of 27,900 (measured by the same method as above) and a molecular weight distribution Mw / Mn = 1.21, having hydroxyl groups at both ends. Subsequently, a methanol solution of NaOMe equivalent to 1.2 times the volume of the hydroxyl groups of this hydroxyl-terminated polypropylene oxide was added, and the methanol was removed by distillation. Then, allyl chloride was added to convert the terminal hydroxyl groups to allyl groups. Unreacted allyl chloride was removed by vacuum defoliation. To 100 parts by weight of the obtained unpurified polypropylene oxide with allyl groups, 300 parts by weight of n-hexane and 300 parts by weight of water were mixed and stirred, and the water was removed by centrifugation. Another 300 parts by weight of water was added to the obtained hexane solution and stirred, and the water was removed again by centrifugation, and the hexane was removed by vacuum defoliation. From the above, a polypropylene oxide with a number-average molecular weight of 27,900 (measured by the same method as above) and a molecular weight distribution Mw / Mn = 1.21, having allyl groups at the terminal sites, was obtained. 100 parts by weight of the obtained polypropylene oxide with allyl groups was reacted with 0.9 parts by weight of dimethoxymethylsilane at 90°C for 2 hours using 36 ppm of an isopropanol solution of a platinum vinylsiloxane complex with a platinum content of 3 wt% as a catalyst. Unreacted dimethoxymethylsilane was then removed under reduced pressure to obtain polyoxypropylene (A-1) with a number-average molecular weight of 28,500, having dimethoxymethylsilyl groups at the terminal sites. Polymer (A-1) was found to have an average of 0.8 dimethoxymethylsilyl groups at each terminal and an average of 1.6 dimethoxymethylsilyl groups per molecule.

[0126] (Synthesis Example 2) Using a polyoxypropylene triol with a number-average molecular weight of approximately 4,500 as an initiator, propylene oxide was polymerized using a zinc hexacyanocobaltate grime complex catalyst to obtain polyoxypropylene (P-1) with a number-average molecular weight of 24,600 (end-group equivalent molecular weight 17,400) and a molecular weight distribution Mw / Mn = 1.31, with hydroxyl groups at the ends. 1.2 molar equivalents of sodium methoxide in a 28% methanol solution were added to the hydroxyl groups of the obtained hydroxyl-terminated polyoxypropylene (P-1). After removing methanol by vacuum defoliation, an additional 1.5 molar equivalents of allyl chloride were added to the hydroxyl groups of the polymer (P-1) to convert the terminal hydroxyl groups to allyl groups. Unreacted allyl chloride was removed by vacuum defoliation. The obtained unpurified polyoxypropylene was mixed and stirred with n-hexane and water, then the water was removed by centrifugation, and the metal salts in the polymer were removed by vacuum defoliation of the hexane from the resulting hexane solution. From the above steps, polyoxypropylene (Q-1) having allyl groups at its termini was obtained. To 500 g of this polymer (Q-1), 50 μl of platinum divinyldisiloxane complex solution (3% by weight isopropanol solution in terms of platinum) was added, and 6.4 g of dimethoxymethylsilane was slowly added dropwise while stirring. After reacting at 100°C for 2 hours, the unreacted dimethoxymethylsilane was removed under reduced pressure to obtain polyoxypropylene (A-2) with dimethoxymethylsilyl groups at its termini and a number-average molecular weight of 26,200. Polymer (A-2) was found to have an average of 0.7 dimethoxymethylsilyl groups at each termini and an average of 2.2 dimethoxymethylsilyl groups per molecule.

[0127] (Synthesis Example 3) To 500 g of polymer (Q-1) obtained in Synthesis Example 2, 50 μl of platinum divinyldisiloxane complex solution (3 wt% isopropanol solution in terms of platinum) was added, and 6.9 g of trimethoxysilane was slowly added dropwise while stirring. After reacting at 100°C for 2 hours, the unreacted trimethoxysilane was removed by distillation under reduced pressure to obtain polyoxypropylene (A-3) with a number average molecular weight of 26,200 and trimethoxysilyl groups at the ends. Polymer (A-3) was found to have an average of 0.7 trimethoxysilyl groups at each end and an average of 2.0 trimethoxysilyl groups per molecule.

[0128] (Synthesis Example 4) To the hydroxyl groups of polyoxypropylene glycol with a number-average molecular weight of approximately 4,500, 1.2 equivalents of a methanol solution of sodium methoxide were added, and the methanol was removed by distillation at 130°C. Then, 1.5 equivalents of 3-chloro-1-propene were added at 130°C to convert the hydroxyl groups to allyl groups. After removing the remaining salts, 36 ppm of platinum divinyldisiloxane complex (a solution of isopropyl alcohol at 3% by mass in terms of platinum) and 6.0 parts by weight of methyldimethoxysilane were added to 100 parts by weight of the obtained allyl-terminated polyoxypropylene, and the mixture was reacted at 90°C for 2 hours. After that, the unreacted dimethoxymethylsilane was removed by distillation under reduced pressure to obtain polyoxypropylene (A-4) with a number-average molecular weight of 5,000 and dimethoxymethylsilyl groups at the ends. Polymer (A-1) was found to have an average of 0.7 dimethoxymethylsilyl groups at each end and an average of 1.4 groups per molecule.

[0129] (Synthesis Example 5) Using polyoxypropylenediol 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 hydroxyl-terminated polyoxypropylene with a number average molecular weight of approximately 15,000. Subsequently, 1.2 equivalents of a methanol solution of sodium methoxide was added to the hydroxyl groups of this hydroxyl-terminated polyoxypropylene, and the methanol was removed by distillation at 140°C. Then, 1.6 equivalents of 3-chloro-1-propene were added to convert the terminal hydroxyl groups to allyl groups. Next, 36 ppm of platinum divinyldisiloxane complex (a solution of isopropyl alcohol at 3% by mass in terms of platinum) and 1.7 parts by weight of methyldimethoxysilane were added to 100 parts by weight of the obtained allyl-terminated polyoxypropylene, and the mixture was reacted at 90°C for 2 hours. After that, the unreacted dimethoxymethylsilane was removed under reduced pressure to obtain polyoxypropylene (A-5) with a number-average molecular weight of 15,000 and dimethoxymethylsilyl groups at the ends. Polymer (A-5) was found to have an average of 0.8 dimethoxymethylsilyl groups at each end and an average of 1.6 dimethoxymethylsilyl groups per molecule.

[0130] (Synthesis Example 6) In a four-necked flask equipped with a stirrer, 74.4 parts by weight of phenyltrimethoxysilane, 98.1 parts by weight of methyltrimethoxysilane, 23.6 parts by weight of water (40 mol% relative to 100 mol% of alkoxy groups in the alkoxysilane component), and 0.1 parts by weight of 10% LiBr aqueous solution were added at room temperature. The mixture was then heated and reacted under reflux due to the methanol generated for 6 hours to obtain a methanol solution of polysiloxane (B-1). In polysiloxane (B-1), the molar ratio of methyl groups directly bonded to silicon atoms to phenyl groups is 50:50. The T3 ratio of polysiloxane (B-1) was found to be 29%.

[0131] (Synthesis Example 7) In a four-necked flask equipped with a stirrer, 74.4 parts by weight of phenyltrimethoxysilane, 98.1 parts by weight of methyltrimethoxysilane, 26.5 parts by weight of water (45 mol% relative to 100 mol% of alkoxy groups in the alkoxysilane component), and 0.1 parts by weight of 10% LiBr aqueous solution were added at room temperature. The mixture was then heated and reacted under reflux due to the methanol generated for 6 hours to obtain a methanol solution of polysiloxane (B-2). In polysiloxane (B-2), the molar ratio of methyl groups and phenyl groups directly bonded to silicon atoms was 50:50. The T3 ratio of polysiloxane (B-2) was found to be 35%.

[0132] (Synthesis Example 8) In a four-necked flask equipped with a stirrer, 74.4 parts by weight of phenyltrimethoxysilane, 98.1 parts by weight of methyltrimethoxysilane, 29.5 parts by weight of water (50 mol% relative to 100 mol% of alkoxy groups in the alkoxysilane component), and 0.1 parts by weight of 10% LiBr aqueous solution were added at room temperature. The mixture was then heated and reacted under reflux due to the methanol generated for 6 hours to obtain a methanol solution of polysiloxane (B-3). In polysiloxane (B-3), the molar ratio of methyl groups directly bonded to silicon atoms to phenyl groups is 50:50. The T3 ratio of polysiloxane (B-3) was found to be 44%.

[0133] (Synthesis Example 9) In a four-necked flask equipped with a stirrer, 111.6 parts by weight of phenyltrimethoxysilane, 49.0 parts by weight of methyltrimethoxysilane, 19.8 parts by weight of water (40 mol% relative to 100 mol% of alkoxy groups in the alkoxysilane component), and 0.1 parts by weight of 10% LiBr aqueous solution were added at room temperature. The mixture was then heated and reacted under reflux due to the methanol generated for 6 hours to obtain a methanol solution of polysiloxane (B-4). In polysiloxane (B-4), the molar ratio of methyl groups directly bonded to silicon atoms to phenyl groups is 25:75. The T3 ratio of polysiloxane (B-4) was found to be 21%.

[0134] (Synthesis Example 10) In a four-necked flask equipped with a stirrer, 37.2 parts by weight of phenyltrimethoxysilane, 147.1 parts by weight of methyltrimethoxysilane, 27.3 parts by weight of water (40 mol% relative to 100 mol% of alkoxy groups in the alkoxysilane component), and 0.1 parts by weight of 10% LiBr aqueous solution were added at room temperature. The mixture was then heated and reacted under reflux due to the methanol generated for 6 hours to obtain a methanol solution of polysiloxane (B-5). In polysiloxane (B-5), the molar ratio of methyl groups directly bonded to silicon atoms to phenyl groups was 75:25. The T3 ratio of polysiloxane (B-5) was found to be 38%.

[0135] (Comparative Synthesis Example 1) In a four-necked flask equipped with a stirrer, 74.4 parts by weight of phenyltrimethoxysilane, 98.1 parts by weight of methyltrimethoxysilane, 41.3 parts by weight of water (70 mol% relative to 100 mol% of alkoxy groups in the alkoxysilane component), and 0.1 parts by weight of 10% LiBr aqueous solution were added at room temperature. The mixture was then heated and reacted under reflux due to the methanol generated for 6 hours to obtain a methanol solution of polysiloxane (B'-1). In polysiloxane (B'-1), the molar ratio of methyl groups and phenyl groups directly bonded to silicon atoms was 50:50. The T3 ratio of polysiloxane (B'-1) was found to be 47%.

[0136] (Examples 1-6 and Comparative Examples 1-5) Components (A) and (B) were mixed so that the solid content ratio was as shown in Table 1. Methanol was removed by distillation under reduced pressure. Tin(II) octoate (manufactured by Nitto Chemical Industries, Ltd., trade name: Neostan U-28) and laurylamine (manufactured by Wako Pure Chemical Industries, Ltd.) were added in the weight ratios shown in Table 1 and mixed by hand. Degassing was performed using a centrifuge to obtain a curable composition. The tensile properties of the obtained curable composition were measured as follows.

[0137] The details of the polysiloxane used in Comparative Example 5 are as follows. DOWSIL US-CF2403 Resin: Polymethylsilsesquioxane (manufactured by DOWSIL), T3 ratio 19%

[0138] (Tensile properties) Each curable composition was formed into a 3 mm thick sheet-like test specimen and fully cured by drying at 23°C and 50% RH for 3 days, followed by drying in a 50°C oven for 4 days. After punching out a No. 3 dumbbell shape, a tensile test was performed at a tensile speed of 200 mm / min using a Shimadzu Autograph, and the breaking strength (indicated as TB) was measured.

[0139] [Table 1]

[0140] Table 1 shows that, compared to Comparative Examples 1-3 which consist of component (A) alone, Examples 1-6, which contain component (B) with a T3 ratio of 20-45%, exhibit a significant improvement in tensile strength. On the other hand, in Comparative Example 4, which contained polysiloxane with a T3 ratio of 47%, the curing was too fast, making it impossible to prepare test specimens. Furthermore, in Comparative Example 5, which contained polysiloxane with a T3 ratio of 19%, a decrease in tensile strength occurred compared to Comparative Example 3.

[0141] (Examples 7-13 and Comparative Examples 6-10) Component (A) and component (B) were mixed so that the solid content ratio was as shown in Table 2. Methanol was removed by distillation under reduced pressure, and 50 parts by weight of surface-treated colloidal calcium carbonate (manufactured by Shiraishi Kogyo Co., Ltd., product name: Shiratsuya CCR) was added and kneaded thoroughly. The mixture was then passed once through three small paint rolls. After this, dehydration was carried out under reduced pressure at 120°C for 2 hours, and after cooling to below 50°C, 3 parts by weight of vinyltrimethoxysilane (manufactured by Momentive Performance Materials, product name: Silkquest A-171) as a dehydrating agent, 2 parts by weight of γ-(2-aminoethyl)aminopropyltrimethoxysilane (manufactured by Momentive Performance Materials, product name: Silkquest A-1120) as an adhesion promoter, and curing catalyst (C) were added in the weight ratios shown in Table 2. The mixture was kneaded, filled into a moisture-proof cartridge-type container, and sealed to obtain a curable composition. The tensile properties of the obtained curable composition were measured as shown above.

[0142] The details of the curing catalyst (C) in Table 2 are as follows. Neostan U-220H: Dibutyltin diacetylacetonate (manufactured by Nitto Chemical Co., Ltd.) Neostan U-28: Tin(II) octylate (manufactured by Nitto Chemical Industries, Ltd.) Laurylamine (manufactured by Wako Pure Chemical Industries, Ltd.)

[0143] [Table 2]

[0144] Compared to Comparative Example 6, which contains component (A) alone, Example 7, which incorporates component (B) into component (A), shows improved tensile strength. The same can be said from the comparison between Comparative Example 7 and Examples 8, 12, and 13, between Comparative Example 8 and Example 9, between Comparative Example 9 and Example 10, and between Comparative Example 10 and Example 11.

Claims

1. A curable composition containing a polyoxyalkylene polymer (A) having a reactive silyl group and an organopolysiloxane (B), The organopolysiloxane (B) has a ratio of the sum of T1, T2, and T3 out of the total of all constituent units: [(T1 + T2 + T3) / (Q1 + Q2 + Q3 + Q4 + T1 + T2 + T3 + D1 + D2 + M1)] × 100 which is 80 to 100%, and the T3 ratio, expressed by the formula: [T3 / (Q1 + Q2 + Q3 + Q4 + T1 + T2 + T3 + D1 + D2 + M1)] × 100, is 20% or more and 45% or less. (In the formula, Q1, Q2, Q3, or Q4 each refer to a constituent unit derived from tetraalkoxysilane and forming one, two, three, or four siloxane bonds, respectively.) T1, T2, or T3 each refer to a constituent unit derived from a monoorganotrialkoxysilane, forming one, two, or three siloxane bonds, respectively. D1 or D2, respectively, refers to a structural unit derived from a diorganodialkoxysilane and forming one or two siloxane bonds. M1 refers to a structural unit derived from a triorganomonalkoxysilane that forms one siloxane bond. The organopolysiloxane (B) is a curable composition having an alkyl group (b1) having 1 to 10 carbon atoms and / or an aryl group (b2) having 6 to 10 carbon atoms as organic groups directly bonded to a silicon atom.

2. The curable composition according to claim 1, wherein the organopolysiloxane (B) has an alkyl group having 1 to 10 carbon atoms (b1) and an aryl group having 6 to 10 carbon atoms (b2) as organic groups directly bonded to a silicon atom.

3. The curable composition according to claim 1 or 2, wherein the proportion of the polyoxyalkylene polymer (A) in the total of the polyoxyalkylene polymer (A) and the organopolysiloxane (B) is 60 to 99% by weight.

4. The curable composition according to claim 1 or 2, further comprising a curing catalyst (C).

5. The curable composition according to claim 1 or 2, wherein the polyoxyalkylene polymer (A) has a number average molecular weight of 10,000 or more.

6. The curable composition according to claim 1 or 2, wherein the content of the solvent in the curable composition is 15% by weight or less with respect to the total amount of the curable composition.

7. A cured product obtained by curing the curable composition according to claim 1 or 2.

8. A method for producing the curable composition described in claim 1 or 2, A step of mixing the polyoxyalkylene polymer (A) having the reactive silyl group and the organopolysiloxane (B) in a solvent, and A manufacturing method comprising the step of distilling off the aforementioned solvent.

9. The manufacturing method according to claim 8, further comprising the step of mixing a curing catalyst (C) after the step of distilling off the solvent.

Images