Sclerotic composition

Abstract

To provide a curable composition which comprises a polysilsesquioxane-based polymer and a reactive silyl group-containing polyether polymer, can form a cured product having high strength and has good thixotropic property.SOLUTION: There is provided a curable composition which comprises a polysilsesquioxane polymer (A), a polyalkylene oxide polymer having a reactive silyl group (B1) and / or a poly(meth)acrylic polymer having a reactive silyl group (B2), a curing catalyst (C) and silica (D). (A) has an alkoxysilyl group (a1) and / or a silanol group (a2), an alkyl group having 1 to 10 carbon atoms (b1) and / or an aryl group having 6 to 10 carbon atoms (b2), a polyalkylene oxide polymer chain (c1) and / or a linear poly(meth)acrylic polymer chain (c2). One end of (c1) and / or (c2) is bonded to a polysilsesquioxane skeleton.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable composition containing a polysilsesquioxane polymer.

Background Art

[0002] An organic polymer having a silicon-containing group (hereinafter referred to as "reactive silyl group") having a hydroxyl group or a hydrolyzable group on a silicon atom and capable of forming a siloxane bond is known as a moisture-reactive polymer and is included in many industrial products such as adhesives, sealants, coating materials, paints, and adhesives, and is used in a wide range of fields. As such an organic polymer containing a reactive silyl group, those having a polyalkylene oxide polymer as a main chain skeleton and those of (meth)acrylic polymers are widely used.

[0003] As a method for improving the mechanical properties exhibited after curing an organic polymer having such a reactive silyl group, a technique of blending a polysilsesquioxane-based polymer with the organic polymer is known. A polysilsesquioxane-based polymer is a siloxane-based polymer formed by a hydrolysis / dehydration condensation reaction of an organotrialkoxysilane, and has a compositional formula: (RSiO 1.5 ) n represented by. In the above formula, R represents a monovalent organic group such as a methyl group.

[0004] For example, Patent Document 1 discloses a crosslinked composition containing a polymer having a reactive silyl group and a silicone resin containing a silsesquioxane unit. Further, Patent Document 2 discloses a composition containing a 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

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The curable composition used as a sealing material, an adhesive, etc. is required to be able to form a high-strength cured product and, in addition, to have a property of being less likely to sag immediately after being applied to a substrate, that is, thixotropy. However, conventional curable compositions containing a polysilsesquioxane-based polymer and a reactive silyl group-containing organic polymer have insufficient thixotropy and may be likely to sag immediately after being applied to a substrate.

[0007] In view of the above situation, an object of the present invention is to provide a curable composition containing a polysilsesquioxane-based polymer and a reactive silyl group-containing organic polymer, which can form a high-strength cured product and has good thixotropy.

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 in a curable composition containing a polysilsesquioxane-based polymer and a reactive silyl group-containing organic polymer, by introducing a polyalkylene oxide polymer chain and / or a linear poly(meth)acrylic polymer chain into the polysilsesquioxane-based polymer and blending silica, the above problems can be solved, and the present invention has been completed.

[0009] That is, the present invention relates to a curable composition containing a polysilsesquioxane polymer (A), a polyalkylene oxide polymer (B1) having a reactive silyl group and / or a poly(meth)acrylic polymer (B2) having a reactive silyl group, a curing catalyst (C), and silica (D). The polysilsesquioxane polymer (A) has a polysilsesquioxane skeleton, an alkoxysilyl group (a1) and / or a silanol group (a2) bonded to the polysilsesquioxane skeleton, an alkyl group (b1) having 1 to 10 carbon atoms and / or an aryl group (b2) having 6 to 10 carbon atoms directly bonded to the silicon atom of the polysilsesquioxane skeleton, and a polyalkylene oxide polymer chain (c1) and / or a linear poly(meth)acrylic polymer chain (c2). One end of the polyalkylene oxide polymer chain (c1) and / or the linear poly(meth)acrylic polymer chain (c2) is bonded to the polysilsesquioxane skeleton. Preferably, the weight ratio of the total of the alkyl group (b1) having 1 to 10 carbon atoms and the aryl group (b2) having 6 to 10 carbon atoms to the total of the polyalkylene oxide polymer chain (c1) and the linear poly(meth)acrylic polymer chain (c2) is 10:90 to 90:10. Preferably, the proportion of the polysilsesquioxane polymer (A) in the total of the polysilsesquioxane polymer (A), the polyalkylene oxide polymer (B1) having a reactive silyl group and / or the poly(meth)acrylic polymer (B2) having a reactive silyl group is 1 to 90% by weight. Preferably, the content of the silica (D) is 1 to 60 parts by weight with respect to 100 parts by weight in total of the polysilsesquioxane polymer (A), the polyalkylene oxide polymer (B1) having a reactive silyl group and / or the poly(meth)acrylic polymer (B2) having a reactive silyl group. Preferably, the silica (D) is hydrophilic fumed silica. Further, the present invention may be a sealing material or an adhesive containing the curable composition, or may be a cured product obtained by curing the curable composition.

Effects of the Invention

[0010] According to the present invention, a curable composition containing a polysilsesquioxane polymer and a reactive silyl group-containing organic polymer can be provided, which can form a cured product with high strength and has good thixotropy.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be specifically described.

[0012] The curable composition according to the present disclosure contains at least a polysilsesquioxane polymer (A), a polyalkylene oxide polymer (B1) having a reactive silyl group and / or a poly(meth)acrylic polymer (B2) having a reactive silyl group, a curing catalyst (C), and silica (D). In this curable composition, the alkoxysilyl group (a1) and / or silanol group (a2) of the polysilsesquioxane polymer (A) and the reactive silyl group of the polyalkylene oxide polymer (B1) and / or poly(meth)acrylic polymer (B2) are hydrolyzed and dehydrated and condensed to cure, forming a cured product.

[0013] <<Polysilsesquioxane Polymer (A)>> The polysilsesquioxane polymer (A) according to the present disclosure has at least a polysilsesquioxane skeleton, an alkoxysilyl group (a1) and / or a silanol group (a2), an alkyl group (b1) having 1 to 10 carbon atoms and / or an aryl group (b2) having 6 to 10 carbon atoms, and a polyalkylene oxide polymer chain (c1) and / or a linear poly(meth)acrylic polymer chain (c2).

[0014] The polysilsesquioxane skeleton refers to a siloxane-based polymer skeleton represented by the compositional formula (RSiO 1.5 ) n and is composed of a hydrolysis condensate of an alkoxysilane component containing at least organotrialkoxysilane.

[0015] The organotrialkoxysilane refers to a silane compound having one organic group bonded to a silicon atom and three alkoxy groups bonded to the silicon atom, and is represented by the formula: RSi(OR’)3. In the formula, R represents the organic group, and OR’ represents the alkoxy group. The organic group refers to an organic group other than the alkoxy group, and includes at least an alkyl group having 1 to 10 carbon atoms and / or an aryl group having 6 to 10 carbon atoms.

[0016] The alkoxy group: OR’ bonded to the silicon atom is the same group as the alkoxy group in the alkoxysilyl group (a1) that the polysilsesquioxane polymer (A) may have, and specifically may be an alkoxy group having 1 to 3 carbon atoms. More specifically, a methoxy group, an ethoxy group, and a propoxy group can be mentioned, a methoxy group and an ethoxy group are preferable, and a methoxy group is more preferable. The alkoxy group may be only one type, or two or more types may be mixed.

[0017] The organotrialkoxysilane includes at least an organotrialkoxysilane in which the organic group is an alkyl group and / or an organotrialkoxysilane in which the organic group is an aryl group.

[0018] Specific examples of the organotrialkoxysilane in which the organic group is an alkyl group are not particularly limited, and examples include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltriisopropoxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltriisopropoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, pentyltriisopropoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, etc. Among them, methyltrialkoxysilane is preferable, and methyltrimethoxysilane is particularly preferable.

[0019] Specific examples of the organotrialkoxysilane in which the organic group is an aryl group are not particularly limited. For example, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, tolyltrimethoxysilane, tolyltriethoxysilane, tolyltripropoxysilane, xylyltrimethoxysilane, xylyltriethoxysilane, xylyltripropoxysilane, naphthyltrimethoxysilane, naphthyltriethoxysilane, naphthyltripropoxysilane, etc. may be mentioned. Among them, phenyltrialkoxysilane is preferable, and phenyltrimethoxysilane is particularly preferable.

[0020] The alkoxysilane component may contain an organotrialkoxysilane in which the organic group is an alkyl group and may not contain an organotrialkoxysilane in which the organic group is an aryl group. Conversely, it may contain an organotrialkoxysilane in which the organic group is an aryl group and may not contain an organotrialkoxysilane in which the organic group is an alkyl group. Further, it may contain both an organotrialkoxysilane in which the organic group is an alkyl group and an organotrialkoxysilane in which the organic group is an aryl group.

[0021] When the alkoxysilane component contains both, the molar ratio (alkyl group: aryl group) of the organotrialkoxysilane in which the organic group is an alkyl group and the organotrialkoxysilane in which the organic group is an aryl group is preferably 1:99 to 99:1 from the viewpoint of the strength of the cured product obtained by curing the curable composition. In particular, from the viewpoint of the appearance of the cured product, 45:55 to 99:1 is preferable.

[0022] In the alkoxysilane component, from the viewpoint of the physical properties exhibited by the polysilsesquioxane polymer (A), the total proportion occupied by organotrialkoxysilane in which the organic group is an alkyl group and organotrialkoxysilane in which the organic group is an aryl group is preferably 80 to 100 mol%, more preferably 90 to 100 mol%, still more preferably 95 to 100 mol%, and particularly preferably 99 to 100 mol%. Examples of alkoxysilanes other than organotrialkoxysilane in which the organic group is an alkyl group and organotrialkoxysilane in which the organic group is an aryl group include organotrialkoxysilane in which the organic group does not correspond to either the alkyl group or the aryl group, diorganodialkoxysilane, triorganomonoalkoxysilane, and tetraalkoxysilane.

[0023] <Alkoxysilyl group (a1) and / or silanol group (a2)> The polysilsesquioxane polymer (A) has an alkoxysilyl group (a1) and / or a silanol group (a2), and these groups are bonded to the polysilsesquioxane skeleton. By having these alkoxysilyl groups (a1) and / or silanol groups (a2), the polysilsesquioxane polymer (A) can exhibit curability by hydrolysis and dehydration condensation reactions.

[0024] The alkoxysilyl group (a1) is a group represented by -SiOR', and is a part of the alkoxy groups contained in the raw material alkoxysilane that remained unreacted during the production of the polysilsesquioxane polymer (A). The alkoxysilyl group may be, for example, an alkoxysilyl group having 1 to 3 carbon atoms. Specifically, examples include methoxysilyl group, ethoxysilyl group, and propoxysilyl group, with methoxysilyl group and ethoxysilyl group being preferred, and methoxysilyl group being more preferred. The alkoxysilyl group may be only one type or two or more types may be mixed.

[0025] The silanol group (a2) is a group represented by -SiOH, and after a part of the alkoxy groups contained in the alkoxysilane as a raw material has undergone a hydrolysis reaction during the production of the polysilsesquioxane polymer (A), the dehydration condensation reaction does not proceed, that is, it remains without forming a siloxane bond.

[0026] <Alkyl group (b1) and / or aryl group (b2)> The polysilsesquioxane polymer (A) further has an alkyl group (b1) having 1 to 10 carbon atoms and / or an aryl group (b2) having 6 to 10 carbon atoms. These alkyl groups (b1) and / or aryl groups (b2) are directly bonded to the silicon atoms of the polysilsesquioxane skeleton and are substituents on the silicon atoms.

[0027] Examples of the alkyl group (b1) having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, etc. The number of carbon atoms of the alkyl group is preferably 1 to 4, more preferably 1 to 3, still more preferably 1 to 2, and particularly preferably 1. The alkyl group may have no substituent, or may have a hetero-containing group such as a halogen atom, an alkoxy group, or an acyl group as a substituent. The alkyl group may be only one type, or two or more types may be used in combination.

[0028] Examples of the aryl group (b2) having 6 to 10 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, etc. The number of carbon atoms of the aryl group is preferably 6 to 10, more preferably 6 to 8, still more preferably 6 to 7, and particularly preferably 6. The aryl group may have no substituent, or may have a hetero-containing group such as a halogen atom, an alkoxy group, or an acyl group as a substituent. The aryl group may be only one type, or two or more types may be used in combination.

[0029] The molar ratio of the alkyl group (b1) to the aryl group (b2) (alkyl group: aryl group) may be 0:100 to 100:0, or may be 1:99 to 99:1. In particular, from the viewpoint of the appearance of the cured product, 45:55 to 99:1 is preferable.

[0030] <Polyalkylene oxide polymer chain (c1) and / or linear poly(meth)acrylic polymer chain (c2)> The polysilsesquioxane polymer (A) further has a polyalkylene oxide polymer chain (c1) and / or a linear poly(meth)acrylic polymer chain (c2). Due to the presence of these polymer chains, a high-strength cured product can be formed, and the thixotropy of the curable composition can be improved. The polysilsesquioxane polymer (A) may have a polyalkylene oxide polymer chain (c1) and not have a poly(meth)acrylic polymer chain (c2), or conversely, may have a poly(meth)acrylic polymer chain (c2) and not have a polyalkylene oxide polymer chain (c1). Also, it may have both a polyalkylene oxide polymer chain (c1) and a poly(meth)acrylic polymer chain (c2).

[0031] In the polysilsesquioxane polymer (A), one end of these polyalkylene oxide polymer chains (c1) and / or linear poly(meth)acrylic polymer chains (c2) is bonded to the polysilsesquioxane skeleton. That is, among the plurality of ends that the polymer chain has, only one specific end is bonded to the polysilsesquioxane skeleton, and the ends other than the specific end are not bonded to the polysilsesquioxane skeleton and are in a free state. Therefore, the polyalkylene oxide polymer chain (c1) and / or the linear poly(meth)acrylic polymer chain (c2) can be said to be monovalent substituents.

[0032] Those in which both ends of the polyalkylene oxide polymer chain or the linear poly(meth)acrylic polymer chain are bonded to the polysilsesquioxane skeleton, crosslinking two polysilsesquioxane skeletons (for example, the structure shown in paragraph 0021 of JP-A-2013-49928) are excluded from the scope of the present disclosure.

[0033] The above-described free ends do not have a reactive silyl group. Therefore, for example, a polymer chain having a reactive silyl group at the end as described in paragraph 0131 of JP-A-2009-185169 is excluded from the scope of the present disclosure. In the polysilsesquioxane polymer (A), the polyalkylene oxide polymer chain (c1) and the linear poly(meth)acrylic polymer chain (c2) preferably do not have a reactive silyl group.

[0034] The manner in which the polysilsesquioxane skeleton is bonded to the polyalkylene oxide polymer chain (c1) and / or the linear poly(meth)acrylic polymer chain (c2) is not particularly limited, but from the viewpoint of stability, it is preferably bonded via a siloxane bond (-Si-O-). Such a siloxane bond can be formed by the reaction of an alkoxysilane component described later with a polyalkylene oxide polymer having a reactive silyl group at one end and / or a linear poly(meth)acrylic polymer having a reactive silyl group at one end.

[0035] The polymer skeleton of the polyalkylene oxide polymer chain (c1) is not particularly limited, and examples thereof include polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, polyoxypropylene-polyoxybutylene copolymer, and the like. Among them, polyoxypropylene is preferred.

[0036] The polyalkylene oxide polymer chain (c1) preferably has a linear polymer backbone. Further, among the two terminals of the linear polymer backbone, it is preferable that only one terminal is bonded to the polysilsesquioxane backbone.

[0037] The polymer backbone of the poly(meth)acrylic polymer chain (c2) is preferably composed of (meth)acrylate-based monomers. Such (meth)acrylate-based monomers are not particularly limited. 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, nonyl (meth)acrylate, 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, 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, 2-perfluorohexadecylethyl (meth)acrylate, etc. may be mentioned. Among these, (meth)acrylate alkyl esters are preferable, acrylate alkyl esters are more preferable, and butyl acrylate is particularly preferable.

[0038] Further, a (meth)acrylic acid ester monomer and other copolymerizable monomers may be used in combination. However, the proportion of the (meth)acrylic acid ester monomer in the total monomers constituting the poly(meth)acrylic polymer chain (c2) is preferably 60% by weight or more and 100% by weight or less, more preferably 80% by weight or more, still more preferably 90% by weight or more, and particularly preferably 95% by weight or more.

[0039] The poly(meth)acrylic polymer chain (c2) has a linear polymer backbone, and only one of the two terminals of the linear polymer backbone is bonded to the polysilsesquioxane backbone. For example, those in which the poly(meth)acrylic polymer chain is bonded to the polysilsesquioxane backbone at a portion other than the terminal of the polymer backbone (for example, in the middle of the polymer backbone) are excluded from the scope of the present disclosure.

[0040] The proportion of the polymer chain (c1) and / or (c2) contained in the polysilsesquioxane polymer (A) is not particularly limited. However, in order to sufficiently enjoy the effects achieved by the polymer chain (c1) and / or (c2), the total of the alkyl group (b1) having 1 to 10 carbon atoms and the aryl group (b2) having 6 to 10 carbon atoms: the total weight ratio of the polyalkylene oxide polymer chain (c1) and the linear poly(meth)acrylic polymer chain (c2) is preferably 10:90 to 90:10. More preferably, it is 15:85 to 85:15. Also, it may be 20:80 to 80:20, or may be 30 to 70:70:30.

[0041] The number average molecular weight of the polysilsesquioxane polymer (A) is preferably 400 to 10,000, and more preferably 500 to 5,000. The number average molecular weight of the polysilsesquioxane polymer (A) can be measured by GPC.

[0042] <Production of Polysilsesquioxane Polymer (A)> The polysilsesquioxane polymer (A) can be produced by subjecting an alkoxysilane component containing the aforementioned organotrialkoxysilane, a polyalkylene oxide polymer having a reactive silyl group at one end, and / or a linear poly(meth)acrylic polymer having a reactive silyl group at one end to hydrolysis and dehydration condensation reactions with water, optionally in the presence of a condensation catalyst.

[0043] When the reaction proceeds between the alkoxy groups in the alkoxysilane component, a polysilsesquioxane skeleton is formed. Also, when the reaction proceeds between the alkoxy group in the alkoxysilane component and the reactive silyl group of the polyalkylene oxide polymer or the poly(meth)acrylic polymer, a polyalkylene oxide polymer chain (c1) and / or a linear poly(meth)acrylic polymer chain (c2) binds to the polysilsesquioxane skeleton.

[0044] Further, during the reaction, some of the alkoxy groups contained in the alkoxysilane component remain unreacted, and / or after the alkoxy groups undergo hydrolysis reaction, the dehydration condensation reaction does not proceed and they remain, so that the produced polysilsesquioxane-based polymer (A) has an alkoxysilyl group (a1) and / or a silanol group (a2).

[0045] It is preferable to carry out the hydrolysis and dehydration condensation reactions by adding water. At this time, by adjusting the amount of water used, the amount of the alkoxysilyl group and / or silanol group possessed by the obtained polysilsesquioxane-based polymer and the molecular weight of the polysilsesquioxane-based polymer can be controlled. From this viewpoint, the amount of water used is preferably 20 mol% or more and 80 mol% or less, more preferably 25 mol% or more and 70 mol% or less, still more preferably 30 mol% or more and 60 mol% or less, and particularly preferably 35 mol% or more and 50 mol% or less with respect to 100% of the total number of moles of the alkoxy groups on the silicon atoms contained in the alkoxysilane component.

[0046] The hydrolysis and dehydration condensation reactions are preferably carried out in the presence of a condensation catalyst to promote the reactions. Known condensation catalysts can be used. Specifically, basic catalysts, acidic catalysts, neutral salts, etc. can be mentioned. To improve the storage stability of the resulting polysilsesquioxane polymer, acidic catalysts and neutral salts are preferred as the condensation catalyst, and neutral salts are more preferred.

[0047] As the acidic catalyst, organic acids are preferred from the viewpoint of compatibility with the alkoxysilane component, 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, etc.

[0048] Examples of the basic catalyst include amine compounds such as N-ethylmorpholine, N-methyldiethanolamine, N-ethyldiethanolamine, N-n-butyldiethanolamine, N-t-butyldiethanolamine, triethylamine, n-butylamine, hexylamine, triethanolamine, diazabicycloundecene, ammonia, etc., and metal hydroxides such as sodium hydroxide, potassium hydroxide, etc.

[0049] The neutral salt is a normal salt composed of a strong acid and a strong base. For example, it is a salt composed of any one selected from the group consisting of Group I element ions, Group II element ions, tetraalkylammonium ions, and guanidinium ions as the cation, and any one selected from the group consisting of Group XVII element ions (excluding fluoride ions), sulfate ions, nitrate ions, and perchlorate ions as the anion. In particular, as the anion, Group XVII element ions are preferred because of their high nucleophilicity, and as the cation, Group I element ions and Group II element ions are preferred as ions that are not bulky so as not to inhibit the nucleophilic action.

[0050] The specific compounds of the neutral salt are not particularly limited, but preferred specific examples include lithium chloride, sodium chloride, potassium chloride, rubidium chloride, cesium chloride, magnesium chloride, calcium chloride, strontium chloride, lithium bromide, sodium bromide, potassium bromide, rubidium bromide, cesium bromide, magnesium bromide, calcium bromide, strontium bromide, lithium iodide, sodium iodide, potassium iodide, rubidium iodide, cesium iodide, magnesium iodide, calcium iodide, strontium iodide, and the like.

[0051] The addition amount of the condensation catalyst can be adjusted as appropriate. For example, it may be about 50 ppm to 3% by weight based on the alkoxysilane component. However, in order to improve the stability of the polysilsesquioxane polymer (A), within the range where the effect of shortening the reaction time by the condensation catalyst is achieved, the smaller the amount of the condensation catalyst used, the more preferable it is.

[0052] The reaction temperature when carrying out the hydrolysis and dehydration condensation step can be appropriately set by those skilled in the art. For example, it is preferable to heat the reaction solution in the range of 50 to 110°C. Also, the reaction time when carrying out the hydrolysis and dehydration condensation step can be appropriately set by those skilled in the art. For example, it may be about 10 minutes to 12 hours.

[0053] The step of removing the alcohol generated by the hydrolysis of the alkoxysilane component during the production of the polysilsesquioxane polymer (A) may be carried out after the hydrolysis and dehydration condensation step. Thereby, the content of volatile components such as alcohol contained in the polysilsesquioxane polymer (A) can be reduced. The step of removing the alcohol can be carried out by subjecting the mixed solution to vacuum distillation to distill off the alcohol. The conditions of the vacuum distillation can be appropriately set by those skilled in the art. For example, the temperature may be about 60 to 160°C.

[0054] <Polyalkylene oxide polymer having a reactive silyl group at one end> The polyalkylene oxide polymer that can be used for producing the polysilsesquioxane polymer (A) according to the present disclosure has a reactive silyl group only at one end of its polymer backbone.

[0055] The reactive silyl group is a silyl group having a hydroxyl group or a hydrolyzable group on a silicon atom, and is a group in which a hydrolysis and dehydration condensation reaction can proceed in the presence of water and, if necessary, a condensation catalyst. Examples of the hydrolyzable group include hydrogen, halogen, alkoxy group, acyloxy group, ketoximate group, amino group, amide group, acid amide group, aminooxy group, mercapto group, alkenyloxy group, etc. Among these, alkoxy groups such as methoxy group and ethoxy group are more preferable because of their mild hydrolyzability and easy handling, and methoxy group and ethoxy group are particularly preferable.

[0056] The reactive silyl group possessed by the polyalkylene oxide polymer is not particularly limited, and examples thereof include trimethoxysilyl group, triethoxysilyl group, tris(2-propenyloxy)silyl group, triacetoxysilyl group, dimethoxymethylsilyl group, diethoxymethylsilyl group, dimethoxyethylsilyl group, (chloromethyl)dimethoxysilyl group, (chloromethyl)diethoxysilyl group, (methoxymethyl)dimethoxysilyl group, (methoxymethyl)diethoxysilyl group, (N,N-diethylaminomethyl)dimethoxysilyl group, (N,N-diethylaminomethyl)diethoxysilyl group, etc.

[0057] Since the polymer backbone of the polyalkylene oxide polymer is the same as the polymer backbone of the above-described polyalkylene oxide polymer chain (c1), the description thereof is omitted.

[0058] As a method for producing a polyalkylene oxide polymer having a reactive silyl group only at one end, a polyalkylene oxide polymer having a hydroxyl group only at one end is produced by polymerizing an epoxy compound with respect to an initiator having one hydroxyl group, and then, using a known method, converting the hydroxyl group into a reactive silyl group-containing group.

[0059] As the initiator having one hydroxyl group, a monohydric alcohol can be used. For example, methanol, ethanol, 2-propanol, n-butanol, iso-butanol, 2-butanol, t-butanol, 2-ethylhexanol, decyl alcohol, lauryl alcohol, tridecanol, cetyl alcohol, stearyl alcohol, oleyl alcohol and the like can be mentioned. Further, low molecular weight polyoxypropylene monoalkyl ether and the like can also be mentioned.

[0060] The number average molecular weight of the polyalkylene oxide polymer having a reactive silyl group at one end is not particularly limited, but in terms of polystyrene equivalent molecular weight by GPC measurement, 500 to 50,000 is preferable, 500 to 30,000 is more preferable, and 1,000 to 10,000 is particularly preferable.

[0061] The weight average molecular weight of the polyalkylene oxide polymer having a reactive silyl group at one end is not particularly limited, but in terms of polystyrene equivalent molecular weight by GPC measurement, 500 to 80,000 is preferable, 3,000 to 70,000 is more preferable, and 5,000 to 65,000 is particularly preferable.

[0062] <Linear poly(meth)acrylic polymer having a reactive silyl group at one end> The poly(meth)acrylic polymer that can be used for producing the polysilsesquioxane polymer (A) according to the present disclosure is a polymer having a linear polymer backbone, and has a reactive silyl group only at one end of the linear backbone. Details of the reactive silyl group are the same as those of the reactive silyl group described above for the polyalkylene oxide polymer, so the description is omitted.

[0063] Since the monomer constituting the poly(meth)acrylic polymer is the same as the (meth)acrylate monomer described above with respect to the poly(meth)acrylic polymer chain (c2), the description thereof is omitted.

[0064] As a method for introducing a reactive silyl group only at one end of the polymer skeleton of the poly(meth)acrylic polymer, a known method can be used without particular limitation. As an example, a method of polymerizing a monomer in the presence of a chain transfer agent having a mercapto group and a reactive silyl group can be mentioned. By using such a chain transfer agent, a reactive silyl group can be introduced only at one end of the polymer skeleton of the linear poly(meth)acrylic polymer.

[0065] The chain transfer agent is not particularly limited, and examples thereof include γ-mercaptopropyldimethoxymethylsilane, γ-mercaptopropyltrimethoxysilane, (mercaptomethyl)dimethoxymethylsilane, (mercaptomethyl)trimethoxysilane, and the like.

[0066] The amount of the chain transfer agent used is preferably 0.1% by weight or more and 20% by weight or less, more preferably 0.3% by weight or more and 15% by weight or less, and still more preferably 0.5% by weight or more and 7% by weight or less, based on the total amount of the total monomer and the chain transfer agent constituting the poly(meth)acrylic polymer.

[0067] The polymerization method for producing a linear poly(meth)acrylic polymer having a reactive silyl group at one end is not particularly limited, but may be a general free radical polymerization. In free radical polymerization, it is preferable to use a polymerization initiator such as an azo compound or a peroxide.

[0068] The number average molecular weight of the linear poly(meth)acrylic polymer having a reactive silyl group at one end is not particularly limited, but in terms of the polystyrene equivalent molecular weight measured by GPC, it is preferably 500 to 50,000, more preferably 500 to 30,000, and particularly preferably 1,000 to 10,000. Among them, since a polymer with low viscosity can be obtained, the number average molecular weight is preferably 7,000 or less.

[0069] The weight average molecular weight of the linear poly(meth)acrylic polymer having a reactive silyl group at one end is not particularly limited, but in terms of the polystyrene equivalent molecular weight measured by GPC, it is preferably 500 to 80,000, more preferably 3,000 to 70,000, and particularly preferably 5,000 to 65,000. Among them, since a polymer with low viscosity can be obtained, the weight average molecular weight is preferably 15,000 or less.

[0070] <<Polyalkylene oxide polymer (B1) having a reactive silyl group>> The polyalkylene oxide polymer (B1) has a reactive silyl group. The reactive silyl group refers to a silicon-containing group having a hydroxyl group or a hydrolyzable group on a silicon atom and capable of forming a siloxane bond by a hydrolysis / dehydration condensation reaction, and specifically, it can be represented by the following general formula (1). -Si(R 1 ) 3-a (X) a (1) In formula (1), R 1 each independently represents a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may have a heteroatom-containing group. X each independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3.

[0071] R 1 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 a substituent.

[0072] R1 The heteroatom-containing group which may have a hydrocarbon group as a substituent is a group containing a heteroatom. Here, an atom other than a carbon atom and a hydrogen atom is defined as a heteroatom.

[0073] Preferable examples of the heteroatom include N, O, S, P, Si, and a halogen atom. For the heteroatom-containing group, the total of the number of carbon atoms and the number of heteroatoms is preferably from 1 to 10, more preferably from 1 to 6, and still more preferably from 1 to 4.

[0074] R 1 Preferable examples of R include, for example, an alkyl group such as a methyl group and an ethyl group; an alkyl group having a heteroatom-containing group such as a chloromethyl group and a methoxymethyl group; a cycloalkyl group such as a cyclohexyl group; an aryl group such as a phenyl group; an aralkyl group such as a benzyl group; and the like. R 1 is preferably a methyl group, a methoxymethyl group, and a chloromethyl group, more preferably a methyl group and a methoxymethyl group, and still more preferably a methyl group.

[0075] Examples of X include, for example, a hydroxyl group, hydrogen, a 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 preferable, and a methoxy group and an ethoxy group are more preferable because of their mild hydrolyzability and easy handling.

[0076] a is 1, 2, or 3. As a, 2 or 3 is preferable, and 2 is particularly preferable from the viewpoints of curability and strength of the cured product.

[0077] Specific examples of the reactive silyl group include, but are not limited to, a trimethoxysilyl group, a triethoxysilyl group, a tris(2-propenyloxy)silyl group, a triacetoxysilyl group, a dimethoxymethylsilyl group, a diethoxymethylsilyl group, a dimethoxyethylsilyl group, a (chloromethyl)dimethoxysilyl group, a (chloromethyl)diethoxysilyl group, a (methoxymethyl)dimethoxysilyl group, a (methoxymethyl)diethoxysilyl group, a (N,N-diethylaminomethyl)dimethoxysilyl group, a (N,N-diethylaminomethyl)diethoxysilyl group, etc. Among these, a dimethoxymethylsilyl group, a trimethoxysilyl group, a triethoxysilyl group, and a (methoxymethyl)dimethoxysilyl group are preferable because a cured product having good mechanical properties can be obtained. From the viewpoint of activity, a trimethoxysilyl group, a (chloromethyl)dimethoxysilyl group, and a (methoxymethyl)dimethoxysilyl group are more preferable, and a trimethoxysilyl group and a (methoxymethyl)dimethoxysilyl group are particularly preferable. From the viewpoint of stability, a dimethoxymethylsilyl group and a triethoxysilyl group are more preferable, and a dimethoxymethylsilyl group is particularly preferable.

[0078] The average number of reactive silyl groups per molecule of the polyalkylene oxide polymer (B1) is preferably more than 1.0, more preferably 1.3 or more, and still more preferably 1.6 or more. The upper limit of the average number is not particularly limited, but is preferably 6 or less, and more preferably 5 or less. Incidentally, the average number of reactive silyl groups per molecule of the polymer (B1) can be calculated from the results of NMR measurement.

[0079] Examples of the polymer backbone of the polyalkylene oxide polymer (B1) include polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, polyoxypropylene-polyoxybutylene copolymer, etc. Each polymer may be mixed in a block form, graft form, etc. Among these, polyoxypropylene is particularly preferred. The polyalkylene oxide polymer (B1) preferably contains 50% by weight or more, more preferably 70% by weight or more of the repeating unit of the alkylene oxide in the polymer backbone.

[0080] The polyalkylene oxide polymer (B1) may be a polymer having any one kind of polymer backbone, or a mixture of two or more polymers having different polymer backbones. Further, for the mixture, it may be a mixture of polymers produced separately, or a mixture produced simultaneously so as to have an arbitrary mixing composition.

[0081] The number average molecular weight of the polyalkylene oxide polymer (B1) is not particularly limited, but as the polystyrene equivalent molecular weight in GPC, 3,000 to 100,000 is preferable, 3,000 to 50,000 is more preferable, and 3,000 to 30,000 is particularly preferable. When the number average molecular weight is within the above range, since the introduction amount of the reactive silyl group is appropriate, a polyalkylene oxide polymer (B1) having an easy-to-handle viscosity and excellent workability can be relatively easily produced while suppressing the production cost within an appropriate range.

[0082] The molecular weight of the polyalkylene oxide polymer (B1) can also be expressed as the molecular weight in terms of end groups determined by directly measuring the end group concentration by titration analysis based on the hydroxyl value measurement method of JIS K 1557 and the principle of the iodine value measurement method defined in JIS K 0070 for the polymer precursor before the introduction of the reactive silyl group, taking into account the structure of the polymer (degree of branching determined by the polymerization initiator used). The molecular weight in terms of end groups of the polyalkylene oxide polymer (B1) can also be obtained by creating a calibration curve of the number average molecular weight determined by general GPC measurement of the polymer precursor and the molecular weight in terms of end groups, and converting the number average molecular weight determined by GPC of the polyalkylene oxide polymer (B1) into the molecular weight in terms of end groups.

[0083] The molecular weight distribution (Mw / Mn) of the polyalkylene oxide polymer (B1) is not particularly limited, but it is preferably narrow. Specifically, it is preferably less than 2.0, more preferably 1.6 or less, still more preferably 1.5 or less, particularly preferably 1.4 or less, even more particularly preferably 1.3 or less, and most particularly preferably 1.2 or less. The molecular weight distribution of the polyalkylene oxide polymer (B1) can be determined from the number average molecular weight and the weight average molecular weight obtained by GPC measurement.

[0084] The production method of the polyalkylene oxide polymer (B1) is not particularly limited, and it can be produced by a known method, for example, as disclosed in International Publication No. 2016 / 03571.

[0085] <<Poly(meth)acrylic polymer (B2) having a reactive silyl group>> The (meth)acrylic acid ester monomer constituting the main chain of the poly(meth)acrylic polymer (B2) having a reactive silyl group is not particularly limited, and various ones can be used. Specifically, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, 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-trimethoxysilyl)propyl (meth)acrylate, (3-dimethoxymethylsilyl)propyl (meth)acrylate, (2-trimethoxysilyl)ethyl (meth)acrylate, (2-dimethoxymethylsilyl)ethyl (meth)acrylate, trimethoxysilylmethyl (meth)acrylate, (dimethoxymethylsilyl)methyl (meth)acrylate, ethylene oxide adduct 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, 2-perfluorohexadecylethyl (meth)acrylate and other (meth)acrylic acid monomers can be mentioned.

[0086] Examples of monomer units other than those described above include acrylic acids such as acrylic acid and methacrylic acid; monomers containing an amide group such as N-methylolacrylamide and N-methylolmethacrylamide; monomers containing an epoxy group such as glycidyl acrylate and glycidyl methacrylate; monomers containing a nitrogen-containing group such as diethylaminoethyl acrylate and diethylaminoethyl methacrylate, and the like.

[0087] The poly(meth)acrylic polymer (B2) may be a polymer obtained by copolymerizing a (meth)acrylic acid ester monomer and a vinyl monomer copolymerizable therewith. The vinyl monomer is not particularly limited, and examples thereof include styrene monomers such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, styrenesulfonic acid and its salts; fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, and vinylidene fluoride; silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; maleic anhydride, maleic acid, monoalkyl esters and dialkyl esters of maleic acid; fumaric acid, monoalkyl esters and dialkyl esters of fumaric acid; maleimide monomers such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, and cyclohexylmaleimide; nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide; vinyl ester monomers such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate; alkenyl monomers such as ethylene and propylene; conjugated diene monomers such as butadiene and isoprene; vinyl chloride, vinylidene chloride, allyl chloride, allyl alcohol, and the like, and a plurality of these may be used as copolymerization components.

[0088] As the poly(meth)acrylic polymer (B2), a (co)polymer composed of a (meth)acrylic acid ester monomer or a copolymer composed of a (meth)acrylic acid ester monomer and a styrene monomer is preferable because of excellent physical properties. A (co)polymer composed of a (meth)acrylic acid ester monomer is more preferable, and a (co)polymer composed of an acrylic acid ester monomer is particularly preferable.

[0089] The poly(meth)acrylic polymer (B2) has a reactive silyl group. Details of the reactive silyl group are the same as those of the reactive silyl group of the polyalkylene oxide polymer (B1), so the description is omitted.

[0090] The production method of the poly(meth)acrylic polymer (B2) is not particularly limited, and it can be produced by a known method, for example, as disclosed in International Publication No. 2016 / 03571.

[0091] The monomer composition of the poly(meth)acrylic polymer (B2) can be selected according to the use and purpose. For applications that require strength, those having a relatively high glass transition temperature (Tg) are preferable, preferably 0°C or higher and 200°C or lower, and more preferably those having a Tg of 20°C or higher and 100°C or lower. Note that Tg is determined by the above-mentioned Fox's formula.

[0092] The number average molecular weight of the poly(meth)acrylic polymer (B2) is not particularly limited, but in terms of the polystyrene equivalent molecular weight measured by GPC, it is preferably 500 or more and 50,000 or less, and more preferably 500 or more and 30,000 or less.

[0093] In the curable composition according to the present disclosure, the content of the polysilsesquioxane polymer (A) can be appropriately determined in consideration of the curability of the composition, the strength of the resulting cured product, etc. However, among the total of the polysilsesquioxane polymer (A) and the polyalkylene oxide polymer (B1) having a reactive silyl group and / or the poly(meth)acrylic polymer (B2) having a reactive silyl group, the proportion of the polysilsesquioxane polymer (A) is preferably 1 to 90% by weight, more preferably 2 to 70% by weight, still more preferably 3 to 60% by weight, particularly preferably 4 to 50% by weight, and most preferably 5 to 40% by weight.

[0094] <<Curing catalyst (C)>> The curable composition according to the present disclosure preferably contains a curing catalyst (C) for the purpose of promoting the reaction of hydrolyzing and dehydrating and condensing the alkoxysilyl group (a1) and / or silanol group (a2) of the polysilsesquioxane polymer (A) with the reactive silyl group of the polyalkylene oxide polymer (B1) and / or the poly(meth)acrylic polymer (B2), that is, the curing reaction.

[0095] As the curing catalyst, conventionally known ones can be used, and specifically, organotin compounds, metal carboxylates, amine compounds, carboxylic acids, alkoxy metals, inorganic acids, etc. can be mentioned.

[0096] Specific examples of the organotin compound include dibutyltin dilaurate, dibutyltin dioctanoate, dibutyltin bis(butyl maleate), dibutyltin diacetate, dibutyltin oxide, dibutyltin bis(acetylacetonate), the reaction product of dibutyltin oxide and a silicate compound, the reaction product of dibutyltin oxide and a phthalic acid ester, dioctyltin diacetate, dioctyltin dilaurate, dioctyltin bis(ethyl maleate), dioctyltin bis(octyl maleate), dioctyltin bis(acetylacetonate), the reaction product of dioctyltin oxide and a silicate compound, etc. Due to the increasing environmental concerns in recent years, dioctyltin compounds are preferred.

[0097] Specific examples of the metal carboxylate include tin carboxylate, bismuth carboxylate, titanium carboxylate, zirconium carboxylate, iron carboxylate, potassium carboxylate, cesium carboxylate, and the like. As the carboxylic acid group, various metals can be combined with the following carboxylic acids.

[0098] Specific examples of the amine compound include amines such as octylamine, 2-ethylhexylamine, laurylamine, stearylamine, etc.; nitrogen-containing heterocyclic compounds such as pyridine, 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), 1,5-diazabicyclo[4,3,0]nonene-5 (DBN), etc.; guanidines such as guanidine, phenylguanidine, diphenylguanidine, etc.; biguanides such as butylbiguanide, 1-o-tolylbiguanide, 1-phenylbiguanide, etc.; amino group-containing silane coupling agents; ketimine compounds, and the like.

[0099] Specific examples of the carboxylic acid include acetic acid, propionic acid, butyric acid, 2-ethylhexanoic acid, lauric acid, stearic acid, oleic acid, linoleic acid, neodecanoic acid, versatic acid, and the like.

[0100] Specific examples of the alkoxy metal include titanium compounds such as tetrabutyl titanate, titanium tetrakis(acetylacetonate), diisopropoxytitanium bis(ethylacetoacetate), etc., aluminum compounds such as aluminum tris(acetylacetonate), diisopropoxyaluminum ethylacetoacetate, etc., and zirconium compounds such as zirconium tetrakis(acetylacetonate).

[0101] As other curing catalysts, fluoride anion-containing compounds, photoacid generators, and photobase generators can also be used.

[0102] Two or more different types of catalysts may be used in combination as the curing catalyst. For example, by using the above-mentioned amine compound in combination with a carboxylic acid or an amine compound in combination with an alkoxy metal, an effect of improving reactivity may be obtained.

[0103] From the viewpoint of the curing rate, it is preferable to use at least one selected from the group consisting of a tetravalent tin compound and an amine compound having an amidine skeleton as the curing catalyst (C).

[0104] From the viewpoint of achieving both an improvement in the curing reaction rate and workability during curing, the blending amount of the curing catalyst (C) is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 15 parts by weight, still more preferably 0.1 to 10 parts by weight, even more preferably 0.5 to 7 parts by weight, and particularly preferably 1 to 5 parts by weight with respect to a total of 100 parts by weight of the polysilsesquioxane polymer (A), the polyalkylene oxide polymer (B1), and / or the poly(meth)acrylic polymer (B2).

[0105] <<Silica (D)>> The curable composition according to the present disclosure further contains silica (D). Thereby, the curable composition can have improved thixotropy and can form a high-strength cured product after curing.

[0106] The type of silica (D) is not particularly limited, and fumed silica, precipitated silica, crystalline silica, fused silica, etc. can be used. Among them, fumed silica is preferable from the viewpoints of the thixotropy improvement effect and the strength of the cured product.

[0107] The fumed silica is silica obtained by hydrolyzing silicon tetrachloride as a raw material in a flame of oxygen and hydrogen, and is also called dry silica. Its structure is generally said to be formed by aggregation and fusion of a plurality of small particles to form a bulky aggregate.

[0108] As the fumed silica, either hydrophobic fumed silica or hydrophilic fumed silica can be used, but hydrophilic fumed silica is preferable from the viewpoints of the thixotropy improvement effect and the strength of the cured product described above.

[0109] The hydrophobic fumed silica refers to fumed silica particles that have been hydrophobized by performing a surface treatment to chemically immobilize compounds such as organosilicon compounds and silicone oils on the surface of the fumed silica particles by utilizing the reactivity of silanol groups (Si-OH) present on the surface of the fumed silica. Specifically, as the surface treatment agent, dimethyldichlorosilane, polydimethylsiloxane, hexamethyldisilazane, octyltrimethoxysilane, octyltrichlorosilane, etc. are used, but it is not limited to these. The hydrophilic fumed silica refers to fumed silica that has not been subjected to the above-described surface treatment, has silanol groups on the silica surface, and exhibits hydrophilicity.

[0110] Examples of commercially available products of the hydrophilic fumed silica include AEROSIL 50, AEROSIL 90G, AEROSIL 130, AEROSIL 200, AEROSIL 300 (all manufactured by Nippon Aerosil Co., Ltd.), etc., and any of them can be used.

[0111] The blending amount of silica (D) may be about 0.1 to 100 parts by weight with respect to a total of 100 parts by weight of the polysilsesquioxane polymer (A) and the polyalkylene oxide polymer (B1) and / or the poly(meth)acrylic polymer (B2). However, from the viewpoints of the above-described thixotropy improvement effect and the strength of the cured product, 1 to 60 parts by weight is preferable, 2 to 30 parts by weight is more preferable, 3 to 20 parts by weight is further preferable, and 4 to 15 parts by weight is particularly preferable.

[0112] <<Curable Composition>> The curable composition according to the present disclosure may contain various additives as necessary, in addition to a polysilsesquioxane polymer (A), a polyalkylene oxide polymer (B1) and / or a poly(meth)acrylic polymer (B2), a curing catalyst (C), and silica (D). Examples of such additives include fillers other than silica, adhesion imparting agents, plasticizers, anti-sagging agents, antioxidants, light stabilizers, ultraviolet absorbers, physical property modifiers, compounds containing epoxy groups, photocurable substances, oxygen-curable substances, and organic resins other than the polyalkylene oxide polymer (B1) and / or the poly(meth)acrylic polymer (B2).

[0113] Also, for the purpose of adjusting various physical properties of the curable composition or the cured product, other additives other than those described above may be added to the curable composition as necessary. Examples of such other additives include, for example, tackifying resins, solvents, diluents, epoxy resins, surface property improvers, foaming agents, curing property adjusters, flame retardants, silicates, radical inhibitors, metal deactivators, ozone degradation inhibitors, phosphorus-based peroxide decomposers, lubricants, pigments, fungicides, and the like.

[0114] The curable composition can be prepared as a one-component type in which all the compounding components are pre-compounded and sealed for storage and cured by moisture in the air after construction. The one-component curable composition preferably does not substantially contain water, and the water content is preferably 5% by weight or less, more preferably 1% by weight or less. Also, as a curing agent, components such as a curing catalyst, a filler, a plasticizer, and water are compounded, and the curing agent and the main agent containing the polysilsesquioxane polymer (A), the polyalkylene oxide polymer (B1) and / or the poly(meth)acrylic polymer (B2) can be prepared as a two-component type to be mixed before use. The main agent of the two-component type preferably does not substantially contain water, and the water content is preferably 5% by weight or less, more preferably 1% by weight or less. From the viewpoint of workability, the one-component type is preferred.

[0115] Prior to curing, the curable composition is shaped into a desired form by methods such as coating, casting, or filling. The curable composition that has been coated, cast, or filled and shaped can be cured at room temperature or under heating. The heat curing conditions are not particularly limited, but are preferably at a temperature of 60 to 220°C for 1 to 120 minutes, and more preferably at a temperature of 100 to 200°C for 5 to 60 minutes.

[0116] The curable composition according to the present disclosure can be used as an adhesive, a pressure-sensitive adhesive, a sealing material for sealing applications in buildings, ships, automobiles, buses, roads, household appliances, etc., a mold release agent, a paint, a spraying agent, etc. Further, the cured product obtained by curing the curable composition is suitably used as a waterproof material, a film waterproof material, a vibration-proof material, a damping material, a sound-proof material, a foaming material, etc.

Examples

[0117] Examples are given below to explain the present invention more specifically, but the present invention is not limited to these examples.

[0118] 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: HLC-8420GPC manufactured by Tosoh Corporation Column: TSKgel SuperH series manufactured by Tosoh Corporation Solvent: THF Molecular weight: Polystyrene conversion Measurement temperature: 40°C

[0119] The end group equivalent molecular weight in each synthesis example was determined by obtaining the hydroxyl value by the measurement method of JIS K 1557 and the iodine value by the measurement method of JIS K 0070, and considering the structure of the organic polymer (the degree of branching determined by the polymerization initiator used).

[0120] The average number of introduced silyl groups of each polymer shown in each synthesis example was calculated by NMR measurement.

[0121] (Synthesis Example 1) Using butanol as an initiator, propylene oxide was polymerized with a zinc hexacyanocobaltate glyme complex catalyst to obtain polyoxypropylene having a hydroxyl group at one end, a number average molecular weight of 7800 (molecular weight in terms of end groups: 5000), and a molecular weight distribution Mw / Mn = 1.48. Subsequently, 1.2 molar equivalents of sodium methoxide as a 28% methanol solution was added to the hydroxyl group of this hydroxyl-terminated polyoxypropylene. After distilling off methanol by vacuum devolatilization, 2.0 molar equivalents of allyl chloride was added to the hydroxyl group of the polymer to convert the terminal hydroxyl group to an allyl group, and unreacted allyl chloride was removed by vacuum devolatilization under reduced pressure. The obtained unpurified polyoxypropylene was mixed and stirred with n-hexane and water, and then water was removed by centrifugation. The hexane in the obtained hexane solution was removed by vacuum devolatilization under reduced pressure to remove metal salts in the polymer. Thus, polyoxypropylene having an allyl group only at one end was obtained. To 500 g of the obtained polymer, 50 μl of a platinum divinyldisiloxane complex (a 2-propanol solution containing 3% by weight of platinum) was added, and while stirring, 9.5 g of dimethoxymethylsilane was slowly added dropwise. After reacting the mixed solution at 100 °C for 2 hours, unreacted dimethoxymethylsilane was distilled off under reduced pressure to obtain polyoxypropylene (c1’-1) having a dimethoxymethylsilyl group only at one end. It was found that the polymer had an average of 0.8 dimethoxymethylsilyl groups only at one end.

[0122] (Synthesis Example 2) Into a four-necked flask equipped with a stirrer, at room temperature, 10.0 parts by weight of polyoxypropylene (c1’-1) having a dimethoxymethylsilyl group only at one end obtained in Synthesis Example 1, 88.3 parts by weight of methyltrimethoxysilane and 66.9 parts by weight of phenyltrimethoxysilane as silane monomers, 21.2 parts by weight of water (40 mol% with respect to 100 mol% of the alkoxy groups in the alkoxysilane component), and 0.1 part by weight of a 10% aqueous LiBr solution were added, and then the mixture was heated and reacted for 6 hours under reflux with the generated methanol. Methanol was removed from the obtained methanol solution under heating and reduced pressure to obtain a polysilsesquioxane polymer (A-1) having a polyalkylene oxide polymer chain (c1-1). It was confirmed by 1 1H NMR that the polysilsesquioxane polymer (A-1) has an alkoxysilyl group (a1) and / or a silanol group (a2). Only one end of the polyalkylene oxide polymer chain (c1) is bonded to the polysilsesquioxane skeleton.

[0123] (Synthesis Example 3) 0.84 g of cuprous bromide, 8.79 g of acetonitrile, 20.0 g of n-butyl acrylate and 1.76 g of diethyl 2,5-dibromoadipate were added, and the mixture was stirred at 70 to 80 °C for about 30 minutes. Pentamethyldiethylenetriamine was added thereto to initiate the reaction. From 30 minutes after the start of the reaction to 2 hours, 80.0 g of n-butyl acrylate was continuously added. Pentamethyldiethylenetriamine was appropriately added during the reaction so that the internal temperature was 70 °C to 90 °C. The total amount of pentamethyldiethylenetriamine used during the polymerization was 0.15 g. Four hours after the start of the reaction, the volatile components were removed by heating and stirring under reduced pressure at 80 °C. 35.0 g of acetonitrile, 21.0 g of 1,7-octadiene and 0.34 g of pentamethyldiethylenetriamine were added thereto and stirring was continued for 8 hours. The mixture was heated and stirred under reduced pressure at 80 °C to remove the volatile components. Butyl acetate was added to this concentrate to dissolve the polymer. Then, diatomaceous earth as a filter aid, aluminum silicate as an adsorbent, and hydrotalcite were added, and the mixture was heated and stirred at an internal temperature of 100 °C in an oxygen-nitrogen mixed gas atmosphere (oxygen concentration 6%). The solid content in the mixed solution was removed by filtration, and the filtrate was heated and stirred under reduced pressure at an internal temperature of 100 °C to remove volatile components. Furthermore, aluminum silicate, hydrotalcite, and a thermal degradation inhibitor were added to this concentrate, and the mixture was heated and stirred under reduced pressure (average temperature about 175 °C, degree of vacuum 10 Torr or less). Furthermore, aluminum silicate and hydrotalcite were added as adsorbents, and an antioxidant was added, and the mixture was heated and stirred at an internal temperature of 150 °C in an oxygen-nitrogen mixed gas atmosphere (oxygen concentration 6%). Butyl acetate was added to this concentrate to dissolve the polymer. Then, the solid content in the mixed solution was removed by filtration, and the filtrate was heated and stirred under reduced pressure to remove volatile components, obtaining a polymer having an alkenyl group. This polymer having an alkenyl group, dimethoxymethylsilane (2.0 molar equivalents relative to the alkenyl group), methyl orthoformate (1.0 molar equivalent relative to the alkenyl group), and a platinum catalyst [xylene solution of bis(1,3-divinyl-1,1,3,3-tetramethyldisiloxane)platinum complex catalyst: hereinafter referred to as the platinum catalyst] (10 mg of platinum per 1 kg of the polymer) were mixed and heated and stirred at 100 °C in a nitrogen atmosphere. It was confirmed that the alkenyl group had disappeared, and the reaction mixture was concentrated to obtain an acrylic polymer (B2-1) having a dimethoxymethylsilyl group at the end. The number average molecular weight of the acrylic polymer was 24,700, the molecular weight distribution was 1.3, and the average number of dimethoxymethylsilyl groups at the end per molecule was 1.9.

[0124] (Example 1) As component (A), 30 parts by weight of the polysilsesquioxane polymer (A-1) obtained in Synthesis Example 2, as component (B), 70 parts by weight of the acrylic polymer (B2-1) obtained in Synthesis Example 3, and as component (D), 2 parts by weight of hydrophilic fumed silica (manufactured by Evonik Industries AG, trade name: AEROSIL 300) were mixed and thoroughly kneaded, and then passed through a small three-roll paint mill three times. Thereafter, dehydration under reduced pressure was carried out at 120 °C for 2 hours, and after cooling to 50 °C or lower, 3 parts by weight of vinyltrimethoxysilane (manufactured by Momentive Performance Materials Inc., trade name: Silquest A-171) as a dehydrating agent, 2 parts by weight of γ-(2-aminoethyl)aminopropyltrimethoxysilane (manufactured by Momentive Performance Materials Inc., trade name: Silquest A-1120) as an adhesion-imparting agent, 1.5 parts by weight of tin(II) octylate (manufactured by Nitto Kasei Co., Ltd., trade name: Neostan U-28) as a curing catalyst (C), and 0.25 part by weight of laurylamine (manufactured by Wako Pure Chemical Industries, Ltd.) were added and kneaded to obtain a curable composition.

[0125] (Example 2, Comparative Examples 1 to 4) As shown in Table 1, a curable composition was obtained in the same manner as in Example 1 except that the blending amounts of the respective components were changed.

[0126] (Viscosity) Each curable composition was filled into a 100-ml cup so that no bubbles were present. Using a BS-type viscometer (manufactured by Tokyo Keiki Inc.) and rotor No. 7, the viscosities of each curable composition at 23 °C and 50% RH under conditions of 2 rpm and 10 rpm were measured. The viscosity ratio was calculated by dividing the value of the viscosity measured at 2 rpm by the value of the viscosity measured at 10 rpm. The results are shown in Table 1. The larger the numerical value of the viscosity ratio, the better the thixotropy.

[0127] (Tensile physical properties) Each curable composition was formed into a sheet-like specimen with a thickness of 3 mm, and was completely cured by placing it under the conditions of 23°C and 50% RH for 3 days and then in a dryer at 50°C for 4 days. After punching out into a No. 3 dumbbell shape, a tensile test was carried out at a tensile speed of 200 mm / min using an autograph manufactured by Shimadzu Corporation, and the breaking strength (denoted as TB) was measured. The results are shown in Table 1.

[0128]

Table 1

[0129] From Table 1, it can be seen that in Examples 1 and 2 in which the components (A), (B), (C), and (D) were blended, the values of the breaking strength of the cured product were larger compared with Comparative Examples 1 to 4 that did not contain any one or more of the components. Moreover, it can be understood that the viscosity ratio of the curable composition showed a large value and the thixotropy was good.

Claims

1. A curable composition comprising: a polysilsesquioxane polymer (A); a poly(meth)acrylic polymer (B2) having a reactive silyl group; a curing catalyst (C); and silica (D), optionally containing a polyalkylene oxide polymer (B1) having a reactive silyl group, wherein the polysilsesquioxane polymer (A) has a polysilsesquioxane skeleton, an alkoxysilyl group (a1) and / or a silanol group (a2) bonded to the polysilsesquioxane skeleton, an alkyl group (b1) having 1 to 10 carbon atoms and / or an aryl group (b2) having 6 to 10 carbon atoms directly bonded to the silicon atom of the polysilsesquioxane skeleton, a polyalkylene oxide polymer chain (c1) and / or a linear poly(meth)acrylic polymer chain (c2), and only one end of the polyalkylene oxide polymer chain (c1) and / or the linear poly(meth)acrylic polymer chain (c2) is bonded to the polysilsesquioxane skeleton.

2. The curable composition according to claim 1, wherein the weight ratio of the total of the alkyl group (b1) having 1 to 10 carbon atoms and the aryl group (b2) having 6 to 10 carbon atoms to the total of the polyalkylene oxide polymer chain (c1) and the linear poly(meth)acrylic polymer chain (c2) is 10:90 to 90:

10.

3. The curable composition according to claim 1 or 2, wherein the proportion of the polysilsesquioxane polymer (A) in the total of the polysilsesquioxane polymer (A), the polyalkylene oxide polymer (B1) having a reactive silyl group, and the poly(meth)acrylic polymer (B2) having a reactive silyl group is 1 to 90% by weight.

4. The curable composition according to any one of claims 1 to 3, wherein the content of the silica (D) is 1 to 60 parts by weight with respect to 100 parts by weight in total of the polysilsesquioxane polymer (A), the polyalkylene oxide polymer (B1) having a reactive silyl group, and the poly(meth)acrylic polymer (B2) having a reactive silyl group.

5. The curable composition according to any one of claims 1 to 4, wherein the silica (D) is hydrophilic fumed silica.

6. A sealing material containing the curable composition according to any one of claims 1 to 5.

7. An adhesive containing the curable composition according to any one of claims 1 to 5.

8. A cured product obtained by curing the curable composition according to any one of Claims 1 to 5.

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