Curable composition, cured product, and method of using curable composition

Abstract

To provide a curable composition with excellent curing properties and storage stability.SOLUTION: A curable composition for use as an adhesive or sealing material for an optical element fixing material comprises the following components (A) and (B), or comprises the following components (A), (B), and (C2). Component (A): A polysilsesquioxane compound (A) having one or more repeating units represented by the following formula (a-1), wherein the content of the repeating units represented by formula (a-1) in the polysilsesquioxane compound (A) is 90 to 100 mol% relative to all repeating units. Component (B): A thermal acid-generating agent. Component (C2): A silane coupling agent with an acid anhydride structure in the molecule.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable composition having excellent curability and storage stability, a cured product obtained by curing the curable composition, and a method of using the curable composition as an adhesive for an optical element fixing material or a sealing material for an optical element fixing material. [Background technology]

[0002] BACKGROUND ART Curable compositions have been improved in various ways depending on the intended use, and have been widely used industrially as raw materials for optical parts and molded articles, adhesives, coating agents, and the like. Furthermore, curable compositions have also been attracting attention as compositions for fixing optical elements, such as adhesives for fixing optical elements and sealing materials for fixing optical elements.

[0003] Optical elements include various lasers such as semiconductor lasers (LDs), light-emitting elements such as light-emitting diodes (LEDs), light-receiving elements, composite optical elements, optical integrated circuits, and the like. In recent years, optical elements that emit blue light or white light, which have shorter peak wavelengths, have been developed and widely used. The brightness of such light-emitting elements with shorter peak wavelengths has increased dramatically, and as a result, the amount of heat generated by the optical elements tends to increase.

[0004] However, with the recent trend toward higher brightness of optical elements, a problem has arisen in that the cured product of the composition for fixing an optical element is exposed to higher energy light or higher temperatures generated by the optical element for a long period of time, resulting in a decrease in adhesive strength.

[0005] In order to solve this problem, Patent Documents 1 to 3 propose compositions for fixing optical elements, which contain a polysilsesquioxane compound as the main component. When an optical element or the like is fixed using a composition for fixing an optical element, the composition for fixing an optical element is usually heated to be cured. However, when a composition for fixing an optical element having poor curing properties is used, it is necessary to extend the heating time or increase the heating temperature, which may cause deterioration of the optical element and its surrounding components or reduce the manufacturing efficiency of the product.

[0006] For this reason, efforts have been made to improve the curability of curable compositions containing polysilsesquioxane compounds. For example, Patent Document 4 describes a condensation reaction type silicone composition containing a specific polysilsesquioxane compound and a condensation reaction catalyst. Patent Document 4 also describes that the condensation reaction type silicone composition has various excellent properties and also has excellent curability (initial curability). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-359933 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-263869 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-328231 [Patent Document 4] WO2017 / 122762 issue Summary of the Invention [Problem to be solved by the invention]

[0008] As described above, the condensation reaction type silicone composition described in Patent Document 4 is said to have a variety of excellent properties and also excellent curability. However, the curing conditions described in the examples of Patent Document 4 involve heating at 120°C for 1 hour, followed by further heating at 150°C for 3 hours, and a curable composition with even better curability has been desired.

[0009] Furthermore, the inventors have found through their investigations that improving the curability of a curable composition may result in a decrease in storage stability.

[0010] The present invention has been made in view of the above-mentioned current state of the prior art, and aims to provide a curable composition excellent in curability and storage stability, a cured product obtained by curing the curable composition, and a method of using the curable composition as an adhesive for an optical element fixing material or a sealing material for an optical element fixing material. In the present invention, "excellent curability" means that when a curing reaction is carried out under predetermined conditions, the viscosity increases in a shorter time and the composition finally hardens. [Means for solving the problem]

[0011] In order to solve the above problems, the present inventors have conducted extensive research into curable compositions containing polysilsesquioxane compounds. As a result, the present inventors have found that a curable composition containing a polysilsesquioxane compound and a thermal acid generator has excellent curability and storage stability, which has led to the completion of the present invention.

[0012] Thus, according to the present invention, there are provided the following curable compositions [1] to [9], cured products

[10] and

[11] , and methods of using the curable compositions

[12] and

[13] . [1] A curable composition containing the following components (A) and (B): Component (A): a polysilsesquioxane compound having one or more repeating units represented by the following formula (a-1):

[0013] [ka]

[0014] [R 1 is a group selected from the group consisting of an unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted alkyl group having 1 to 10 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and a substituted aryl group having 6 to 12 carbon atoms. Component (B): Thermal acid generator [2] The curable composition according to [1], wherein the amount of repeating units represented by formula (a-1) in the component (A) is 70 to 100 mol % of all repeating units in the component (A). [3] The curable composition according to [1] or [2], wherein the mass average molecular weight (Mw) of the component (A) is 500 to 20,000. [4] The curable composition according to any one of [1] to [3], wherein the content of the component (A) is 40 mass % or more and less than 100 mass % of the solid content of the curable composition. [5] The curable composition according to any one of [1] to [4], wherein the component (B) is an onium salt-based thermal acid generator. [6] The curable composition according to any one of [1] to [5], wherein the component (B) satisfies the following requirement (I): [Requirement (I)] The peak temperature (acid generation temperature) of the maximum endothermic peak obtained by differential scanning calorimetry of component (B) is 80 to 180°C at a temperature range of 30 to 300°C and a heating rate of 10°C / min. [7] The curable composition according to any one of [1] to [6], wherein the content of the component (B) is more than 0 parts by mass and not more than 5 parts by mass per 100 parts by mass of the component (A). [8] The curable composition according to any one of [1] to [7], further comprising the following component (C): Component (C): Silane coupling agent [9] The curable composition according to any one of [1] to [8], further comprising a solvent and having a solid content concentration of 50% by mass or more and less than 100% by mass.

[10] A cured product obtained by curing the curable composition according to any one of [1] to [9] above.

[11] The cured product according to

[10] , which is an optical element fixing material.

[12] A method of using the curable composition according to any one of [1] to [9] above as an adhesive for an optical element fixing material.

[13] A method of using the curable composition according to any one of [1] to [9] above as a sealing material for an optical element fixing material. [Effects of the Invention]

[0015] According to the present invention, there are provided a curable composition having excellent curability and storage stability, a cured product obtained by curing the curable composition, and a method for using the curable composition as an adhesive for an optical element fixing material or a sealing material for an optical element fixing material. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention will be described in detail below, divided into the following sections: 1) curable composition, 2) cured product, and 3) method of using the curable composition.

[0017] 1) Curable composition The curable composition of the present invention contains the following components (A) and (B): Component (A): a polysilsesquioxane compound having one or more repeating units represented by the above formula (a-1) Component (B): Thermal acid generator

[0018] [Component (A)] The component (A) constituting the curable composition of the present invention is a polysilsesquioxane compound (hereinafter, sometimes referred to as "polysilsesquioxane compound (A)") having one or more repeating units represented by the following formula (a-1):

[0019] [ka]

[0020] In formula (a-1), R 1 is a group selected from the group consisting of an unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted alkyl group having 1 to 10 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and a substituted aryl group having 6 to 12 carbon atoms.

[0021] R 1 The "unsubstituted alkyl group having 1 to 10 carbon atoms" represented by the following formula (I) preferably has 1 to 6 carbon atoms, and more preferably has 1 to 3 carbon atoms. Examples of the "unsubstituted alkyl group having 1 to 10 carbon atoms" include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-nonyl group, and an n-decyl group.

[0022] R 1 The number of carbon atoms in the "substituted alkyl group having 1 to 10 carbon atoms" represented by the formula (I) is preferably 1 to 6, and more preferably 1 to 3. Note that this number of carbon atoms refers to the number of carbon atoms in the portion excluding the substituent (the alkyl group portion). Therefore, R 1 is a "substituted alkyl group having 1 to 10 carbon atoms", R 1 The number of carbon atoms may exceed 10. Examples of the alkyl group in the "substituted alkyl group having 1 to 10 carbon atoms" include the same groups as those given as the "unsubstituted alkyl group having 1 to 10 carbon atoms".

[0023] The number of atoms of the substituent in the "substituted alkyl group having 1 to 10 carbon atoms" (excluding the number of hydrogen atoms) is usually 1 to 30, and preferably 1 to 20. Examples of the substituent in the "substituted alkyl group having 1 to 10 carbon atoms" include a halogen atom such as a fluorine atom, a chlorine atom, or a bromine atom; a cyano group; and a group represented by the formula: OG. Here, G represents a protecting group for a hydroxyl group. The protecting group for a hydroxyl group is not particularly limited, and examples thereof include known protecting groups known as protecting groups for hydroxyl groups. Examples thereof include acyl protecting groups; silyl protecting groups such as trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, and t-butyldiphenylsilyl; acetal protecting groups such as methoxymethyl, methoxyethoxymethyl, 1-ethoxyethyl, tetrahydropyran-2-yl, and tetrahydrofuran-2-yl; alkoxycarbonyl protecting groups such as t-butoxycarbonyl; and ether protecting groups such as methyl, ethyl, t-butyl, octyl, allyl, triphenylmethyl, benzyl, p-methoxybenzyl, fluorenyl, trityl, and benzhydryl.

[0024] R 1 The number of carbon atoms in the "unsubstituted aryl group having 6 to 12 carbon atoms" represented by the following formula is preferably 6. Examples of the "unsubstituted aryl group having 6 to 12 carbon atoms" include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group.

[0025] R 1 The number of carbon atoms in the "substituted aryl group having 6 to 12 carbon atoms" represented by the formula (I) is preferably 6. Note that this number of carbon atoms refers to the number of carbon atoms in the portion excluding the substituent (the aryl group portion). Therefore, R 1 is a "substituted aryl group having 6 to 12 carbon atoms", R 1 The number of carbon atoms may exceed 12. Examples of the aryl group in the "substituted aryl group having 6 to 12 carbon atoms" include the same groups as those exemplified as the "unsubstituted aryl group having 6 to 12 carbon atoms".

[0026] The number of atoms of the substituent in the "substituted aryl group having 6 to 12 carbon atoms" is usually 1 to 30, and preferably 1 to 20 (excluding the number of hydrogen atoms). Examples of the substituent in the "substituted aryl group having 6 to 12 carbon atoms" include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, isobutyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and isooctyl; halogen atoms such as fluorine, chlorine, and bromine; and alkoxy groups such as methoxy and ethoxy.

[0027] Among these, R 1 As the alkyl group, an unsubstituted alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms and containing a fluorine atom, an alkyl group having 1 to 10 carbon atoms and containing a cyano group, or an unsubstituted aryl group having 6 to 12 carbon atoms is preferred.

[0028] R 1By using a polysilsesquioxane compound (A) in which R is an unsubstituted alkyl group having 1 to 10 carbon atoms, it becomes easier to obtain a curable composition that gives a cured product with superior heat resistance and adhesiveness. In this specification, "a cured product having excellent adhesiveness" means "a cured product having high adhesive strength."

[0029] R 1 By using the polysilsesquioxane compound (A) in which R is an alkyl group having 1 to 10 carbon atoms and a fluorine atom, it becomes easier to obtain a curable composition or a cured product having a low refractive index.

[0030] R 1 By using the polysilsesquioxane compound (A) in which R is an alkyl group having 1 to 10 carbon atoms and a cyano group, it becomes easier to obtain a curable composition that gives a cured product with excellent adhesion to highly polar adherends.

[0031] R 1 By using the polysilsesquioxane compound (A) in which is an unsubstituted aryl group having 6 to 12 carbon atoms, it becomes easier to obtain a curable composition or a cured product having a high refractive index.

[0032] The content of the repeating unit represented by the formula (a-1) in the polysilsesquioxane compound (A) is preferably 70 to 100 mol %, more preferably 80 to 100 mol %, and even more preferably 90 to 100 mol %, based on all repeating units. The content of the repeating unit represented by the formula (a-1) in the polysilsesquioxane compound (A) is, as will be described later, 1 It can be determined by measuring H-NMR.

[0033] The repeating unit represented by the formula (a-1) is represented by the following formula (a-2). 1 / 2 indicates that the oxygen atom is shared with an adjacent repeating unit.

[0034] [ka]

[0035] As shown in formula (a-2), the polysilsesquioxane compound (A) has a structure generally collectively called a T site, in which three oxygen atoms are bonded to a silicon atom and other groups (R 1 ) is bonded to the partial structure. Examples of the T site contained in the polysilsesquioxane compound (A) include those represented by the following formulae (a-3) to (a-5).

[0036] [ka]

[0037] In formulas (a-3) to (a-5), R 1 has the same meaning as above. 2 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. 2 Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group, and a t-butyl group. 2 They may all be the same or different. In the above formulae (a-3) to (a-5), * indicates that a Si atom is bonded.

[0038] The polysilsesquioxane compound (A) is soluble in various organic solvents, such as ketone solvents such as acetone; aromatic hydrocarbon solvents such as benzene; sulfur-containing solvents such as dimethyl sulfoxide; ether solvents such as tetrahydrofuran; ester solvents such as ethyl acetate; halogen-containing solvents such as chloroform; and mixed solvents consisting of two or more of these. Therefore, the polysilsesquioxane compound (A) in a solution state can be dissolved in these solvents. 29 Si-NMR can be measured.

[0039] Polysilsesquioxane compound (A) in solution 29By measuring Si-NMR, the content ratio of the T3 site represented by the formula (a-3), the T2 site represented by the formula (a-4), and the T1 site represented by the formula (a-5) can be determined. From the viewpoint of improving the adhesiveness of the cured product, the polysilsesquioxane compound (A) used in the present invention preferably contains 10 to 45 mol % of T2 sites, more preferably 15 to 40 mol %, and even more preferably 20 to 35 mol %. Furthermore, from the viewpoint of obtaining a hard cured product having excellent heat resistance, the polysilsesquioxane compound (A) used in the present invention preferably contains 50 to 90 mol % of T3 sites, more preferably 55 to 85 mol %, and even more preferably 60 to 80 mol %.

[0040] The polysilsesquioxane compound (A) is a compound having one R 1 and may be a polymer having two or more R 1 The compound may be a copolymer having the following formula:

[0041] When the polysilsesquioxane compound (A) is a copolymer, the polysilsesquioxane compound (A) may be any of a random copolymer, a block copolymer, a graft copolymer, an alternating copolymer, etc., but from the viewpoint of ease of production, etc., a random copolymer is preferred. The structure of the polysilsesquioxane compound (A) may be any of a ladder structure, a double-decker structure, a cage structure, a partially cleaved cage structure, a cyclic structure, and a random structure.

[0042] The mass average molecular weight (Mw) of the polysilsesquioxane compound (A) is usually 500 to 20,000, preferably 1,000 to 15,000, and more preferably 1,500 to 12,000. By using a polysilsesquioxane compound (A) having a mass average molecular weight (Mw) within the above range, it becomes easier to obtain a curable composition that gives a cured product having excellent heat resistance and adhesiveness.

[0043] The molecular weight distribution (Mw / Mn) of the polysilsesquioxane compound (A) is not particularly limited, but is usually 1.0 to 10.0, and preferably 1.1 to 6.0. By using a polysilsesquioxane compound (A) having a molecular weight distribution (Mw / Mn) within the above range, it becomes easier to obtain a curable composition that gives a cured product having excellent heat resistance and adhesiveness. The mass average molecular weight (Mw) and number average molecular weight (Mn) can be determined, for example, as values ​​converted into standard polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0044] In the present invention, the polysilsesquioxane compound (A) can be used alone or in combination of two or more. The content of the polysilsesquioxane compound (A) in the solid content of the curable composition is preferably 40 mass % or more and less than 100 mass %, more preferably 48 to 95 mass %, and even more preferably 56 to 90 mass %. In the present invention, the term "solid content" refers to components other than the solvent in the curable composition.

[0045] The method for producing the polysilsesquioxane compound (A) is not particularly limited. For example, the polysilsesquioxane compound (A) can be produced by polycondensing at least one silane compound (1) represented by the following formula (a-6):

[0046] [ka]

[0047] In the formula, R 1 has the same meaning as above. 3 represents an alkyl group having 1 to 10 carbon atoms, and X 1 represents a halogen atom, and p represents an integer of 0 to 3. 3 , and multiple X 1 may be the same as or different from each other. R 3As the alkyl group having 1 to 10 carbon atoms, R 2 Examples of the alkyl group include the same alkyl groups having 1 to 10 carbon atoms as those given above. X 1 Examples of the halogen atom include a chlorine atom and a bromine atom.

[0048] Specific examples of the silane compound (1) include alkyltrialkoxysilane compounds such as methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and ethyltrippropoxysilane; alkylhalogenoalkoxysilane compounds such as methylchlorodimethoxysilane, methylchlorodiethoxysilane, methyldichloromethoxysilane, methylbromodimethoxysilane, ethylchlorodimethoxysilane, ethylchlorodiethoxysilane, ethyldichloromethoxysilane, and ethylbromodimethoxysilane; Alkyltrihalogenosilane compounds such as methyltrichlorosilane, methyltribromosilane, ethyltrichlorosilane, and ethyltribromosilane;

[0049] substituted alkyltrialkoxysilane compounds such as 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 2-cyanoethyltrimethoxysilane, and 2-cyanoethyltriethoxysilane; substituted alkylhalogenoalkoxysilane compounds such as 3,3,3-trifluoropropylchlorodimethoxysilane, 3,3,3-trifluoropropylchlorodiethoxysilane, 3,3,3-trifluoropropyldichloromethoxysilane, 3,3,3-trifluoropropyldichloroethoxysilane, 2-cyanoethylchlorodimethoxysilane, 2-cyanoethylchlorodiethoxysilane, 2-cyanoethyldichloromethoxysilane, and 2-cyanoethyldichloroethoxysilane; substituted alkyltrihalogenosilane compounds such as 3,3,3-trifluoropropyltrichlorosilane and 2-cyanoethyltrichlorosilane;

[0050] phenyltrialkoxysilane compounds, such as phenyltrimethoxysilane and 4-methoxyphenyltrimethoxysilane, which may or may not have a substituent; phenylhalogenoalkoxysilane compounds having or having no substituents, such as phenylchlorodimethoxysilane, phenyldichloromethoxysilane, 4-methoxyphenylchlorodimethoxysilane, and 4-methoxyphenyldichloromethoxysilane; phenyltrihalogenosilane compounds, such as phenyltrichlorosilane and 4-methoxyphenyltrichlorosilane, which may or may not have a substituent; and the like. These silane compounds (1) can be used singly or in combination of two or more.

[0051] The method for polycondensing the silane compound (1) is not particularly limited. For example, a method can be used in which a predetermined amount of a polycondensation catalyst is added to the silane compound (1) in a solvent or without a solvent, followed by stirring at a predetermined temperature. More specifically, examples include (a) a method in which a predetermined amount of an acid catalyst is added to the silane compound (1) and the mixture is stirred at a predetermined temperature, (b) a method in which a predetermined amount of a base catalyst is added to the silane compound (1) and the mixture is stirred at a predetermined temperature, and (c) a method in which a predetermined amount of an acid catalyst is added to the silane compound (1) and the mixture is stirred at a predetermined temperature, and then an excess amount of a base catalyst is added to make the reaction system basic, followed by stirring at a predetermined temperature. Among these, methods (a) and (c) are preferred because they allow the desired polysilsesquioxane compound (A) to be obtained efficiently.

[0052] The polycondensation catalyst used may be either an acid catalyst or a base catalyst. Two or more polycondensation catalysts may be used in combination, but it is preferred to use at least an acid catalyst. Examples of the acid catalyst include inorganic acids such as phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, and nitric acid; and organic acids such as citric acid, acetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. Among these, at least one selected from phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, citric acid, acetic acid, and methanesulfonic acid is preferred.

[0053] Examples of the base catalyst include aqueous ammonia; organic bases such as trimethylamine, triethylamine, lithium diisopropylamide, lithium bis(trimethylsilyl)amide, pyridine, 1,8-diazabicyclo[5.4.0]-7-undecene, aniline, picoline, 1,4-diazabicyclo[2.2.2]octane, and imidazole; organic hydroxides such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; metal alkoxides such as sodium methoxide, sodium ethoxide, sodium t-butoxide, and potassium t-butoxide; metal hydrides such as sodium hydride and calcium hydride; metal hydroxides such as sodium hydroxide, potassium hydroxide, and calcium hydroxide; metal carbonates such as sodium carbonate, potassium carbonate, and magnesium carbonate; and metal hydrogencarbonates such as sodium hydrogencarbonate and potassium hydrogencarbonate.

[0054] The amount of the polycondensation catalyst used is usually in the range of 0.05 to 10 mol %, preferably 0.1 to 5 mol %, based on the total molar amount of the silane compound (1).

[0055] When a solvent is used during polycondensation, the solvent can be appropriately selected depending on the type of silane compound (1). Examples of suitable solvents include water; aromatic hydrocarbons such as benzene, toluene, and xylene; esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and methyl propionate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, s-butyl alcohol, and t-butyl alcohol. These solvents can be used alone or in combination of two or more. Furthermore, when using the above method (c), after polycondensation reaction in an aqueous system in the presence of an acid catalyst, an organic solvent and an excess amount of a basic catalyst (such as aqueous ammonia) can be added to the reaction solution, and further polycondensation reaction can be carried out under basic conditions.

[0056] The amount of the solvent used is 0.1 liters or more and 10 liters or less, preferably 0.1 liters or more and 2 liters or less, per mole of the total amount of the silane compound (1).

[0057] The temperature at which the silane compound (1) is polycondensed is usually in the range of 0°C to the boiling point of the solvent used, preferably in the range of 20°C to 100°C. If the reaction temperature is too low, the polycondensation reaction may not proceed sufficiently. On the other hand, if the reaction temperature is too high, it becomes difficult to suppress gelation. The reaction is usually completed within 30 minutes to 30 hours.

[0058] Depending on the type of monomer used, it may be difficult to increase the molecular weight. For example, R 1 is an alkyl group having a fluorine atom, R 1 In such cases, the polysilsesquioxane compound (A) having the desired molecular weight can be more easily obtained by reducing the amount of catalyst and carrying out the reaction for a long period of time under mild conditions.

[0059] After completion of the reaction, if an acid catalyst was used, the reaction solution is neutralized by adding an aqueous alkali solution such as sodium bicarbonate, or if a base catalyst was used, the reaction solution is neutralized by adding an acid such as hydrochloric acid, and the salt generated during this process is removed by filtration or washing with water, to obtain the desired polysilsesquioxane compound (A).

[0060] When the polysilsesquioxane compound (A) is produced by the above method, the OR of the silane compound (1) 3 or X 1 The portion of the polysilsesquioxane compound (A) that has not undergone dealcoholization or the like remains in the polysilsesquioxane compound (A). Therefore, the polysilsesquioxane compound (A) may contain T sites represented by the formulas (a-4) and (a-5) in addition to the T site represented by the formula (a-3).

[0061] [(B) component] The component (B) that constitutes the curable composition of the present invention is a thermal acid generator. The thermal acid generator refers to a compound that generates an acid component such as a Lewis acid or a Bronsted acid when heated. The curable composition of the present invention contains a thermal acid generator, and therefore has excellent curability and storage stability.

[0062] The thermal acid generator preferably has a maximum endothermic peak temperature (acid generation temperature) of 80 to 180°C, as determined by differential scanning calorimetry at a temperature range of 30 to 300°C and a heating rate of 10°C / min. A curable composition containing a thermal acid generator having an acid generation temperature of 80°C or higher under the above conditions has superior storage stability, while a curable composition containing a thermal acid generator having an acid generation temperature of 180°C or lower under the above conditions has superior curability. Since these effects are more easily obtained, the acid generation temperature under the above conditions is preferably 90 to 170°C, more preferably 100 to 160°C.

[0063] Examples of the thermal acid generator include onium salt-based thermal acid generators, which contain an onium cation component and an anion component. Examples of the onium cation component include an organic sulfonium ion, an organic ammonium ion, an organic phosphonium ion, and an organic iodonium ion.

[0064] Examples of organic sulfonium ions constituting onium salt-based thermal acid generators include cations represented by the following formula (b-1).

[0065] [ka]

[0066] In formula (b-1), R 4 , R 5 , R 6are each independently a group selected from the group consisting of an unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted alkyl group having 1 to 10 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and a substituted aryl group having 6 to 12 carbon atoms.

[0067] R 4 ~R 6 The "unsubstituted alkyl group having 1 to 10 carbon atoms" represented by the following formula (I) preferably has 1 to 6 carbon atoms, and more preferably has 1 to 3 carbon atoms. Examples of the "unsubstituted alkyl group having 1 to 10 carbon atoms" include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-nonyl group, and an n-decyl group.

[0068] R 4 ~R 6 The number of carbon atoms in the "substituted alkyl group having 1 to 10 carbon atoms" represented by the formula (I) is preferably 1 to 6, and more preferably 1 to 3. Note that this number of carbon atoms refers to the number of carbon atoms in the portion excluding the substituent (the alkyl group portion). Therefore, R 4 ~R 6 is a "substituted alkyl group having 1 to 10 carbon atoms", R 4 ~R 6 The number of carbon atoms may exceed 10. Examples of the alkyl group in the "substituted alkyl group having 1 to 10 carbon atoms" include the same groups as those given as the "unsubstituted alkyl group having 1 to 10 carbon atoms".

[0069] The number of atoms of the substituent in the "substituted alkyl group having 1 to 10 carbon atoms" (excluding the number of hydrogen atoms) is usually 1 to 30, and preferably 1 to 20. Examples of the substituent in the "substituted alkyl group having 1 to 10 carbon atoms" include aryl groups such as phenyl, o-tolyl, m-tolyl, p-tolyl, 1-naphthyl, and 2-naphthyl.

[0070] R 4 ~R 6The number of carbon atoms in the "unsubstituted aryl group having 6 to 12 carbon atoms" represented by the following formula is preferably 6. Examples of the "unsubstituted aryl group having 6 to 12 carbon atoms" include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group.

[0071] R 4 ~R 6 The number of carbon atoms in the "substituted aryl group having 6 to 12 carbon atoms" represented by the formula (I) is preferably 6. Note that this number of carbon atoms refers to the number of carbon atoms in the portion excluding the substituent (the aryl group portion). Therefore, R 4 ~R 6 is a "substituted aryl group having 6 to 12 carbon atoms", R 4 ~R 6 The number of carbon atoms may exceed 12. Examples of the aryl group in the "substituted aryl group having 6 to 12 carbon atoms" include the same groups as those exemplified as the "unsubstituted aryl group having 6 to 12 carbon atoms".

[0072] The number of atoms of the substituent in the "substituted aryl group having 6 to 12 carbon atoms" is usually 1 to 30, and preferably 1 to 20 (excluding the number of hydrogen atoms). Examples of the substituent in the "substituted aryl group having 6 to 12 carbon atoms" include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, isobutyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and isooctyl; alkoxy groups such as methoxy and ethoxy; hydroxyl; and acyloxy groups such as acetyloxy and propionyloxy.

[0073] Examples of organic ammonium ions that constitute onium salt-based thermal acid generators include cations represented by the following formula (b-2).

[0074] [ka]

[0075] In formula (b-2), R7 , R 8 , R 9 , R 10 are each independently a group selected from the group consisting of an unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted alkyl group having 1 to 10 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and a substituted aryl group having 6 to 12 carbon atoms. R 7 ~R 10 As for R 4 ~R 6 Examples include those similar to those expressed as:

[0076] Examples of organic phosphonium ions constituting onium salt-based thermal acid generators include cations represented by the following formula (b-3).

[0077] [ka]

[0078] In formula (b-3), R 11 , R 12 , R 13 , R 14 are each independently a group selected from the group consisting of an unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted alkyl group having 1 to 10 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and a substituted aryl group having 6 to 12 carbon atoms. R 11 ~R 14 As for R 4 ~R 6 Examples include those similar to those expressed as:

[0079] Examples of organic iodonium ions that constitute onium salt-based thermal acid generators include cations represented by the following formula (b-4).

[0080] [ka]

[0081] In formula (b-4), R15 , R 16 are each independently a group selected from the group consisting of an unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted alkyl group having 1 to 10 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and a substituted aryl group having 6 to 12 carbon atoms. R 15 , R 16 As for R 4 ~R 6 Examples include those similar to those expressed as:

[0082] Among these, the onium cation component is preferably an organic sulfonium ion or an organic ammonium ion, since it has an appropriate acid generation temperature from the viewpoint of achieving both the curability and storage stability of the curable composition and is easy to control the reactivity of the acid generation reaction, and more preferably an organic sulfonium ion represented by the following formula (b-5):

[0083] [ka]

[0084] In formula (b-5), Ar represents an aryl group which has or has no substituent, such as a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 1-naphthyl group, or a 2-naphthyl group.

[0085] Examples of the anion component of the onium salt-based thermal acid generator include trifluoromethanesulfonate anion, hexafluorophosphate anion, hexafluoroantimonate anion, perfluorobutanesulfonate anion, tetrakis(pentafluorophenyl)borate anion, and tetrafluoroborate anion.

[0086] Among these, the anion component is preferably a hexafluorophosphate anion, a hexafluoroantimonate anion, or a tetrakis(pentafluorophenyl)borate anion, as these tend to produce a cured product with excellent optical properties, with a hexafluorophosphate anion being more preferred.

[0087] The thermal acid generators can be used alone or in combination of two or more. The content of the thermal acid generator is usually more than 0 parts by mass and not more than 5 parts by mass, preferably 0.001 to 3.0 parts by mass, more preferably 0.005 to 2.0 parts by mass, even more preferably 0.010 to 1.5 parts by mass, and particularly preferably 0.015 to 1.0 part by mass, relative to 100 parts by mass of the polysilsesquioxane compound (A). If the content of the thermal acid generator is too high, the adhesiveness of the cured product may decrease.

[0088] [Curable composition] The curable composition of the present invention may contain a silane coupling agent as component (C). By using a curable composition containing a silane coupling agent, it becomes easier to obtain a cured product with superior adhesiveness. The silane coupling agent refers to a silane compound having a silicon atom, a functional group, and a hydrolyzable group bonded to the silicon atom. The functional group refers to a group that is reactive with other compounds (mainly organic substances), and examples thereof include groups having a nitrogen atom such as an amino group, a substituted amino group, an isocyanate group, a ureido group, and a group having an isocyanurate skeleton; an acid anhydride group; a vinyl group; an allyl group; an epoxy group; a (meth)acrylic group; a mercapto group; and the like. In the present invention, the silane coupling agent may be used alone or in combination of two or more.

[0089] When the curable composition of the present invention contains a silane coupling agent, the content thereof is not particularly limited and can be appropriately determined depending on the purpose. The content of the silane coupling agent is usually 95 parts by mass or less, preferably 65 parts by mass or less, and more preferably 35 parts by mass or less, per 100 parts by mass of the polysilsesquioxane compound (A).

[0090] As the silane coupling agent, a silane coupling agent having a nitrogen atom in the molecule or a silane coupling agent having an acid anhydride structure in the molecule is preferred.

[0091] A curable composition containing a silane coupling agent having a nitrogen atom in the molecule or a silane coupling agent having an acid anhydride structure in the molecule tends to give a cured product having superior heat resistance and adhesiveness.

[0092] Examples of silane coupling agents having a nitrogen atom in the molecule include trialkoxysilane compounds represented by the following formula (c-1), dialkoxyalkylsilane compounds or dialkoxyarylsilane compounds represented by the following formula (c-2), and the like.

[0093] [ka]

[0094] In the above formula, R a represents an alkoxy group having 1 to 6 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, or a t-butoxy group. a They may be the same or different. R b represents an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a t-butyl group; or an aryl group having or having no substituent, such as a phenyl group, a 4-chlorophenyl group, a 4-methylphenyl group, or a 1-naphthyl group.

[0095] R c represents an organic group having a nitrogen atom and having 1 to 10 carbon atoms. c may further be bonded to another group containing a silicon atom. R c Specific examples of the organic group having 1 to 10 carbon atoms include an N-2-(aminoethyl)-3-aminopropyl group, a 3-aminopropyl group, an N-(1,3-dimethyl-butylidene)aminopropyl group, a 3-ureidopropyl group, and an N-phenyl-aminopropyl group.

[0096] Among the compounds represented by the above formula (c-1) or (c-2), R c However, examples of compounds that are organic groups bonded to other groups containing silicon atoms include silane coupling agents having an isocyanurate skeleton (isocyanurate-based silane coupling agents) and silane coupling agents having a urea skeleton (urea-based silane coupling agents).

[0097] Among these, as silane coupling agents having a nitrogen atom in the molecule, isocyanurate-based silane coupling agents and urea-based silane coupling agents are preferred because they tend to give cured products with superior adhesiveness, and further, those having four or more alkoxy groups bonded to silicon atoms in the molecule are preferred. "Having four or more alkoxy groups bonded to a silicon atom" means that the total number of alkoxy groups bonded to the same silicon atom and alkoxy groups bonded to different silicon atoms is four or more.

[0098] An example of an isocyanurate-based silane coupling agent having four or more alkoxy groups bonded to a silicon atom is a compound represented by the following formula (c-3): An example of an urea-based silane coupling agent having four or more alkoxy groups bonded to a silicon atom is a compound represented by the following formula (c-4):

[0099] [ka]

[0100] In the formula, R a has the same meaning as above. t1 to t5 each independently represent an integer of 1 to 10, preferably an integer of 1 to 6, and particularly preferably 3.

[0101] Among these, as the silane coupling agent having a nitrogen atom in the molecule, it is preferable to use 1,3,5-N-tris(3-trimethoxysilylpropyl)isocyanurate, 1,3,5-N-tris(3-triethoxysilylpropyl)isocyanurate (hereinafter referred to as "isocyanurate compound"), N,N'-bis(3-trimethoxysilylpropyl)urea, N,N'-bis(3-triethoxysilylpropyl)urea (hereinafter referred to as "urea compound"), and combinations of the above-mentioned isocyanurate compounds and urea compounds.

[0102] When the curable composition of the present invention contains a silane coupling agent having a nitrogen atom in the molecule, its content is not particularly limited, but the mass ratio of the above component (A) to the silane coupling agent having a nitrogen atom in the molecule [component (A):silane coupling agent having a nitrogen atom in the molecule] is preferably 100:0.1 to 100:90, more preferably 100:0.3 to 100:60, more preferably 100:1 to 100:50, even more preferably 100:3 to 100:40, and particularly preferably 100:5 to 100:35. The curable composition containing the component (A) and the silane coupling agent having a nitrogen atom in the molecule in such a ratio will produce a cured product with excellent heat resistance and adhesiveness.

[0103] Silane coupling agents having an acid anhydride structure in the molecule are organosilicon compounds that have both a group having an acid anhydride structure and a hydrolyzable group in one molecule.Specific examples include compounds represented by the following formula (c-5).

[0104] [ka]

[0105] In the formula, Q represents a group having an acid anhydride structure, and R d represents an alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted phenyl group, and R erepresents an alkoxy group having 1 to 6 carbon atoms or a halogen atom, i and k represent integers of 1 to 3, j represents an integer of 0 to 2, and i+j+k=4. When j is 2, R d When k is 2 or 3, multiple R e When i is 2 or 3, multiple Qs may be the same or different. Examples of Q include groups represented by the following formulae, and the group represented by (Q1) is particularly preferred.

[0106] [ka]

[0107] In the formula, h represents an integer of 0 to 10.

[0108] Examples of silane coupling agents having an acid anhydride structure in the molecule include tri(C1-C6)alkoxysilyl(C2-C8)alkyl succinic anhydrides, such as 2-(trimethoxysilyl)ethyl succinic anhydride, 2-(triethoxysilyl)ethyl succinic anhydride, 3-(trimethoxysilyl)propyl succinic anhydride, and 3-(triethoxysilyl)propyl succinic anhydride; Di(C1-C6)alkoxymethylsilyl(C2-C8)alkyl succinic anhydrides such as 2-(dimethoxymethylsilyl)ethyl succinic anhydride; (C1-C6)alkoxydimethylsilyl(C2-C8)alkyl succinic anhydrides such as 2-(methoxydimethylsilyl)ethyl succinic anhydride;

[0109] Trihalogenosilyl (C2-C8) alkyl succinic anhydrides such as 2-(trichlorosilyl)ethyl succinic anhydride and 2-(tribromosilyl)ethyl succinic anhydride; Dihalogenomethylsilyl (C2-C8) alkyl succinic anhydrides such as 2-(dichloromethylsilyl)ethyl succinic anhydride; halogenodimethylsilyl (having 2 to 8 carbon atoms) alkyl succinic anhydrides such as 2-(chlorodimethylsilyl)ethyl succinic anhydride; and the like.

[0110] Among these, as the silane coupling agent having an acid anhydride structure in the molecule, tri(C1 to C6)alkoxysilyl(C2 to C8)alkyl succinic anhydride is preferred, and 3-(trimethoxysilyl)propyl succinic anhydride or 3-(triethoxysilyl)propyl succinic anhydride is particularly preferred.

[0111] When the curable composition of the present invention contains a silane coupling agent having an acid anhydride structure in the molecule, its content is not particularly limited. The content of the silane coupling agent having an acid anhydride structure in the molecule is an amount such that the mass ratio of the above component (A) to the silane coupling agent having an acid anhydride structure in the molecule [component (A):silane coupling agent having an acid anhydride structure in the molecule] is preferably 100:0.1 to 100:30, more preferably 100:0.3 to 100:20, more preferably 100:0.5 to 100:15, and even more preferably 100:1 to 100:10. The curable composition containing the component (A) and the silane coupling agent having an acid anhydride structure in the molecule in such a ratio will have a cured product with excellent adhesiveness.

[0112] The curable composition of the present invention may contain other components as long as the object of the present invention is not impaired. Examples of other components include fine particles, antioxidants, ultraviolet absorbers, light stabilizers, and solvents.

[0113] The addition of fine particles may sometimes result in a curable composition that is easy to work with in the coating process. Examples of the material of the fine particles include metals, metal oxides, minerals, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, metal hydroxides such as aluminum hydroxide, metal silicates such as aluminum silicate, calcium silicate and magnesium silicate, inorganic components such as silica, silicones, and organic components such as acrylic polymers. The particles used may also be surface-modified.

[0114] These fine particles can be used alone or in combination of two or more. The content of the fine particles is not particularly limited, but is generally preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, of the component (A).

[0115] The antioxidant is added to prevent oxidative deterioration during heating. Examples of the antioxidant include phosphorus-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants.

[0116] Examples of phosphorus-based antioxidants include phosphites, oxaphosphaphenanthrene oxides, etc. Examples of phenol-based antioxidants include monophenols, bisphenols, polymeric phenols, etc. Examples of sulfur-based antioxidants include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, etc.

[0117] These antioxidants can be used alone or in combination of two or more. The content of the antioxidant is not particularly limited, but is usually 10% by mass or less based on the component (A).

[0118] The ultraviolet absorber is added for the purpose of improving the light resistance of the resulting cured product. Examples of ultraviolet absorbers include salicylic acids, benzophenones, benzotriazoles, and hindered amines. The ultraviolet absorber may be used alone or in combination of two or more. The content of the ultraviolet absorber is not particularly limited, but is usually 10% by mass or less based on the component (A).

[0119] The light stabilizer is added for the purpose of improving the light resistance of the resulting cured product. Examples of light stabilizers include hindered amines such as poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidine)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidine)imino}]. These light stabilizers can be used alone or in combination of two or more. The content of the light stabilizer is usually 20 mass % or less based on the component (A).

[0120] The solvent is not particularly limited as long as it can dissolve or disperse the components of the curable composition of the present invention. Examples of the solvent include acetates such as diethylene glycol monobutyl ether acetate and 1,6-hexanediol diacetate; tripropylene glycol-n-butyl ether; diglycidyl ethers such as glycerin diglycidyl ether, butanediol diglycidyl ether, diglycidyl aniline, neopentyl glycol glycidyl ether, cyclohexanedimethanol diglycidyl ether, alkylene diglycidyl ether, polyglycol diglycidyl ether, and polypropylene glycol diglycidyl ether; triglycidyl ethers such as trimethylolpropane triglycidyl ether and glycerin triglycidyl ether; and vinylhexene oxides such as 4-vinylcyclohexene monoxide, vinylcyclohexene dioxide, and methylated vinylcyclohexene dioxide. The solvents can be used alone or in combination of two or more.

[0121] When the curable composition of the present invention contains a solvent, the content thereof is preferably an amount such that the solid content concentration is 50% by mass or more and less than 100% by mass, more preferably 60 to 90% by mass, and even more preferably 65 to 85% by mass. When the solid content concentration is within this range, a curable composition that is excellent in workability in the coating step can be easily obtained.

[0122] The curable composition of the present invention can be prepared, for example, by mixing the above-mentioned components (A) and (B), and, if desired, other components, in predetermined ratios, followed by degassing. The mixing method and degassing method are not particularly limited, and known methods can be used.

[0123] The curable composition of the present invention contains a polysilsesquioxane compound (A) and a thermal acid generator, and therefore has excellent curability and storage stability.

[0124] The excellent curability of the curable composition of the present invention can be confirmed, for example, by the method described in the Examples. Specifically, when a sample of the curable composition is placed on a stainless steel plate heated to 150°C and stirred using an automatic curing time measuring device (manufactured by Cyber ​​Corporation, product name "Madoka"), the stirring torque increases. Therefore, the curability can be quantified by measuring the time it takes for the stirring torque to reach 0.049 N·cm. The time required for the stirring torque to reach 0.049 N·cm is preferably 1000 seconds or less, more preferably 800 seconds or less, and even more preferably 500 seconds or less.

[0125] As described above, the curable composition of the present invention has excellent curability. Therefore, by using the curable composition of the present invention, working time can be shortened compared to when using conventional curable compositions.

[0126] The excellent storage stability of the curable composition of the present invention can be confirmed, for example, by the method described in the Examples. That is, in a rheometer, a cone plate with a radius of 50 mm and a cone angle of 0.5° is used, and the shear rate is 2 s at 25°C. -1 The viscosity at this time is measured to obtain the initial viscosity, and then the sample is allowed to stand at 25°C for 24 hours, and the viscosity is measured under the same conditions to obtain the viscosity after standing. The storage stability can be quantified by calculating the rate of increase in viscosity from the obtained measured values ​​based on the following formula. [Viscosity increase rate] = [Viscosity after standing] / [Initial viscosity] The viscosity increase rate under the above measurement conditions is preferably 1.40 or less, more preferably 1.25 or less, and even more preferably 1.10 or less.

[0127] As described above, the curable composition of the present invention has excellent storage stability, and therefore can be stored for a long period of time without being frozen or refrigerated.

[0128] 2) Cured product The cured product of the present invention is obtained by curing the curable composition of the present invention. The curable composition of the present invention can be cured by heat curing. The heating temperature during curing is usually 80 to 140° C., more preferably 90 to 120° C. The heating time is usually 30 minutes to 5 hours, preferably 1 to 3 hours.

[0129] The cured product of the present invention preferably has excellent heat resistance and adhesiveness. The heat resistance and adhesiveness of the cured product can be evaluated, for example, as follows. That is, a predetermined amount of the curable composition of the present invention is applied to the mirror surface of a silicon chip, the coated surface is placed on an adherend, pressed together, and cured by heat treatment. This is left for 30 seconds on the measurement stage of a bond tester preheated to a predetermined temperature (e.g., 100°C), and stress is applied horizontally (in the shear direction) to the adhesive surface from a position 100 μm above the adherend to measure the adhesive strength between the test piece and the adherend.

[0130] The adhesive strength of the cured product of the present invention is 15 N / 4 mm under the measurement conditions described in the examples. 2 More than 25N / 4mm is preferable. 2 More preferably, it is 30N / 4mm or more. 2 More preferably, it is equal to or greater than this. In this specification, "4 mm 2 " means "2mm square," that is, 2mm x 2mm (a square with each side measuring 2mm).

[0131] A cured product having excellent heat resistance and adhesiveness can be efficiently formed, for example, by curing a curable composition containing the component (C). A cured product having excellent heat resistance and adhesiveness is more preferably used as a material for fixing optical elements.

[0132] 3) Method of using the curable composition The method of the present invention is a method of using the curable composition of the present invention as an adhesive for an optical element fixing material or a sealing material for an optical element fixing material. Examples of optical elements include light-emitting elements such as LEDs and LDs, light-receiving elements, composite optical elements, and optical integrated circuits.

[0133] <Adhesive for fixing optical elements> The curable composition of the present invention can be suitably used as an adhesive for fixing optical elements. The curable composition of the present invention can be used as an adhesive for fixing optical elements by applying the composition to one or both bonding surfaces of the materials to be bonded (such as an optical element and its substrate), pressing the composition together, and then heating and curing the composition to firmly bond the materials to be bonded together. The amount of the curable composition to be applied is not particularly limited, as long as it is an amount that can firmly bond the materials to be bonded together upon curing. Typically, the amount is such that the thickness of the coating film of the curable composition becomes 0.5 to 5 μm, preferably 1 to 3 μm.

[0134] Substrate materials for bonding optical elements include glasses such as soda lime glass and heat-resistant hard glass; ceramics; sapphire; metals such as iron, copper, aluminum, gold, silver, platinum, chromium, titanium and alloys of these metals, and stainless steel (SUS302, SUS304, SUS304L, SUS309, etc.); and synthetic resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ethylene-vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyether ether ketone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyimide, polyamide, acrylic resin, norbornene-based resin, cycloolefin resin, and glass epoxy resin.

[0135] The heating temperature during heat curing varies depending on the curable composition used, but is usually 80 to 150° C., more preferably 90 to 130° C. The heating time is usually 30 minutes to 5 hours, preferably 1 to 3 hours.

[0136] <Sealant for fixing optical elements> The curable composition of the present invention can be suitably used as a sealing material for fixing optical elements. Examples of methods for using the curable composition of the present invention as a sealing material for an optical element fixing material include a method in which the composition is molded into a desired shape to obtain a molded body containing an optical element, and then the molded body is heated and cured to produce a sealed optical element. The method for molding the curable composition of the present invention into a desired shape is not particularly limited, and known molding methods such as ordinary transfer molding and casting can be used.

[0137] The heating temperature during heat curing varies depending on the curable composition used, but is usually 80 to 150° C., more preferably 90 to 130° C. The heating time is usually 30 minutes to 5 hours, preferably 1 to 3 hours. [Example]

[0138] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0139] (average molecular weight measurement) The mass average molecular weight (Mw) and number average molecular weight (Mn) of the polysilsesquioxane compounds obtained in the Production Examples were measured using the following apparatus under the following conditions, with values ​​calculated in terms of standard polystyrene. Device name: HLC-8220GPC, manufactured by Tosoh Corporation Column: TSKgel GMHXL, TSKgel GMHXL, and TSKgel 2000HXL connected in sequence Solvent: tetrahydrofuran Injection volume: 80μl Measurement temperature: 40℃ Flow rate: 1ml / min Detector: differential refractometer

[0140] (IR spectrum measurement) The IR spectrum of the polysilsesquioxane compound obtained in the Production Examples was measured using a Fourier transform infrared spectrophotometer (Spectrum 100, manufactured by PerkinElmer).

[0141] ( 29 Si-NMR measurement) To investigate the repeating units and their amounts in the polysilsesquioxane compounds obtained in the production examples, 29 Si-NMR measurements were carried out. Equipment: Bruker Biospin AV-500 29 Si-NMR resonance frequency: 99.352MHz Probe: 5mmφ solution probe Measurement temperature: room temperature (25℃) Sample rotation speed: 20kHz Measurement method: Inverse gate decoupling method 29 Si flip angle: 90° 29 Si 90° pulse width: 8.0 μs Repeat time: 5 seconds Accumulation count: 9200 times Observation width: 30kHz

[0142] ( 29 Si-NMR sample preparation method To shorten the relaxation time, Fe(acac)3 was added as a relaxation reagent. Polysilsesquioxane compound concentration: 30% by mass Fe(acac)3 concentration: 0.7% by mass Measurement solvent: acetone Internal standard: TMS

[0143] (waveform processing analysis) For each peak in the spectrum after Fourier transformation, the chemical shift was determined from the peak top position and integrated.

[0144] (Measurement of Acid Generation Temperature of Thermal Acid Generator) Differential scanning calorimetry was performed on each thermal acid generator using a differential scanning calorimeter (manufactured by TA Instruments; product name: DSC Q2000Auto) under the following conditions: starting temperature 30°C, measurement temperature range 30 to 300°C, and heating rate 10°C / min. From the obtained DSC curve, the peak temperature (°C) of the maximum endothermic peak was calculated to obtain the acid generation temperature of each thermal acid generator.

[0145] (Production Example 1) A 300 ml eggplant-shaped flask was charged with 71.37 g (400 mmol) of methyltriethoxysilane, and then an aqueous solution of 0.10 g of 35 mass % hydrochloric acid (0.25 mol % relative to methyltriethoxysilane) dissolved in 21.6 ml of distilled water was added while stirring. The entire mixture was stirred at 30°C for 2 hours, then heated to 70°C and stirred for 5 hours. While continuing to stir the contents, 140 g of propyl acetate and 0.12 g of 28 mass % aqueous ammonia (0.5 mol % relative to methyltriethoxysilane) were added thereto, and the mixture was stirred at 70° C. for 3 hours. The reaction mixture was allowed to cool to room temperature, and then purified water was added thereto for separation. This process was repeated until the pH of the aqueous layer reached 7. The organic layer was concentrated using an evaporator, and the concentrate was dried under vacuum to obtain polysilsesquioxane compound (A1) [PSQ(A1)]. The mass-average molecular weight (Mw) of PSQ(A1) was 7,800, and the molecular weight distribution (Mw / Mn) was 4.52. The IR spectrum data of PSQ(A1) is shown below. Si-CH3: 1272 cm -1 ,1409cm -1 , Si-O: 1132 cm -1 Also, 29 As a result of Si-NMR spectrum measurement, the peak integral ratio of T1, T2, and T3 was 0:24:76.

[0146] (Production Example 2) A 300 mL recovery flask was charged with 17.0 g (77.7 mmol) of 3,3,3-trifluoropropyltrimethoxysilane and 32.33 g (181.3 mmol) of methyltriethoxysilane, and then, while stirring, an aqueous solution obtained by dissolving 0.0675 g of 35 mass % hydrochloric acid (the amount of HCl was 0.65 mmol, 0.25 mol% relative to the total amount of the silane compounds) in 14.0 g of distilled water was added, and the entire mixture was stirred at 30°C for 2 hours, then heated to 70°C and stirred for 20 hours. While continuing to stir the contents, a mixed solution of 0.0394 g of 28% by mass ammonia water (NH3 content: 0.65 mmol) and 46.1 g of propyl acetate was added thereto to adjust the pH of the reaction solution to 6.9, and the mixture was stirred at 70°C for 40 minutes. After allowing the reaction mixture to cool to room temperature, 50 g of propyl acetate and 100 g of water were added and the mixture was separated to obtain an organic layer containing the reaction product. Magnesium sulfate was added to this organic layer and the mixture was dried. After filtering off the magnesium sulfate, the organic layer was concentrated using an evaporator, and the resulting concentrate was then dried under vacuum to obtain polysilsesquioxane compound (A2) [PSQ(A2)]. The mass-average molecular weight (Mw) of PSQ(A2) was 5,500, and the molecular weight distribution was 3.40. The IR spectrum data of PSQ(A2) is shown below. Si-CH3: 1272 cm -1 ,1409cm -1 , Si-O: 1132 cm -1 ,CF:1213cm -1 Also, 29 As a result of Si-NMR spectrum measurement, the ratio of the peak integral values ​​of T1, T2, and T3 was 2:27:71.

[0147] (Production Example 3) A 300 ml eggplant-shaped flask was charged with 20.2 g (102 mmol) of phenyltrimethoxysilane, 3.15 g (18 mmol) of 2-cyanoethyltrimethoxysilane, and 96 ml of acetone and 24 ml of distilled water as solvents. Then, while stirring the contents, 0.15 g (1.5 mmol) of phosphoric acid was added as a catalyst, and the mixture was stirred at 25°C for an additional 16 hours. After the reaction was completed, the reaction mixture was concentrated to 50 ml using an evaporator. 100 ml of ethyl acetate was added to the concentrate and neutralized with saturated aqueous sodium bicarbonate. After allowing to stand for a while, the organic layer was separated. The organic layer was then washed twice with distilled water and dried over anhydrous magnesium sulfate. After filtering off the magnesium sulfate, the filtrate was concentrated to 50 ml using an evaporator. The resulting concentrate was added dropwise to a large amount of n-hexane to precipitate, and the precipitate was separated by decantation. The resulting precipitate was dissolved in methyl ethyl ketone (MEK) and recovered, and the solvent was removed under reduced pressure using an evaporator. The residue was dried in vacuo to obtain polysilsesquioxane compound (A3) [PSQ(A3)]. The mass-average molecular weight (Mw) of PSQ(A3) was 1,870, and the molecular weight distribution (Mw / Mn) was 1.42. The IR spectrum data of PSQ(A3) is shown below. Si-Ph:698cm -1 ,740cm -1 , Si-O: 1132 cm -1 ,-CN:2259cm -1 Also, 29As a result of Si-NMR spectrum measurement, the ratio of the peak integral values ​​of T1, T2, and T3 was 0:33:67.

[0148] The compounds used in the examples and comparative examples are shown below. (Component A) PSQ(A1)~(A3)

[0149] (Component B and comparative compounds) Thermal acid generator (B1): a compound represented by the following formula (acid generation temperature: 150°C)

[0150] [ka]

[0151] Thermal acid generator (B2): a compound represented by the following formula (acid generation temperature: 125°C)

[0152] [ka]

[0153] Thermal acid generator (B3): a compound represented by the following formula (acid generation temperature: 125°C)

[0154] [ka]

[0155] Thermal acid generator (B4): KING INDUSTRIES thermal acid generator, product name "CXC-1612" (a salt consisting of hexafluoroantimonate anion and a quaternary ammonium cation) (acid generation temperature: 115°C)

[0156] Hardening accelerator (X1): Hydrochloric acid Curing accelerator (X2): Ti complex

[0157] (C component) Silane coupling agent (C1): 1,3,5-N-tris[3-(trimethoxysilyl)propyl]isocyanurate Silane coupling agent (C2): 3-(trimethoxysilyl)propylsuccinic anhydride

[0158] Example 1 To 100 parts by mass of PSQ (A1), a mixed solvent of diethylene glycol monobutyl ether acetate:tripropylene glycol-n-butyl ether = 40:60 (mass ratio), 30 parts by mass of silane coupling agent (C1), and 3 parts by mass of silane coupling agent (C2) were added, and the whole was stirred. To this, 1 part of thermal acid generator (B1) (added as a 10 mass% ethyl acetate solution) was added, and the whole was thoroughly mixed to obtain a curable composition.

[0159] (Examples 2 to 19, Comparative Examples 1 to 7) A curable composition was obtained in the same manner as in Example 1, except that the components in Example 1 were changed to those shown in Table 1.

[0160] The curable compositions obtained in the examples and comparative examples were subjected to the following measurements and tests, and the results are shown in Table 1.

[0161] [Curing evaluation] The curing time of the curable composition was measured by the following method using an automatic curing time measuring device "Madoka" (manufactured by Cyber ​​Corporation). 0.30 mL of sample was placed on a stainless steel plate heated to 150°C and stirred. The stirring torque increased over time, and the time (seconds) until the stirring torque reached 0.049 N·cm was measured. The stirring conditions were as follows: Rotation speed of stirring blade: 200 rpm Rotation speed of stirring blade: 80 rpm (The stirring blades are made of polytetrafluoroethylene.) Gap (distance between heating plate and stirring blade): 0.3mm

[0162] [Adhesion strength evaluation] A square with a side length of 2 mm (area of ​​4 mm 2The curable compositions obtained in the Examples and Comparative Examples were applied to the mirror surface of a silicon chip (1.5 mm thick) to a thickness of approximately 2 μm, and the applied surface was placed on an adherend (silver-plated copper plate) and pressed against it. The composition was then cured by heat treatment at 100°C for 2 hours to obtain an adherend with a test piece attached. This adherend with the test piece attached was left for 30 seconds on the measurement stage of a bond tester (manufactured by Daige, Series 4000) that had been preheated to 100°C, and a stress was applied in the horizontal direction (shear direction) to the adhesive surface at a speed of 200 μm / s from a position 100 μm above the adherend, and the adhesive strength (N / 4 mm) between the test piece and the adherend at 100°C was measured. 2 ) was measured.

[0163] [Evaluation of viscosity increase rate] Using a rheometer (Anton Paar, MCR301) with a cone plate of 50 mm radius and 0.5° cone angle, the shear rate was 2 s at 25°C. -1 The viscosity at that time (initial viscosity) was measured. The sample was allowed to stand at 25°C for 24 hours, and then the viscosity was measured under the same conditions. From the obtained measured values, the viscosity increase rate was calculated based on the following formula. [Viscosity increase rate] = [Viscosity after standing] / [Initial viscosity]

[0164] [Table 1]

[0165] The following can be seen from the above examples and comparative examples. In the curable compositions of Examples 1 to 19, in the curability evaluation test, cured products were obtained in a short time of 1000 seconds or less, demonstrating excellent curability. Furthermore, the cured products obtained in Examples 1 to 19 had a small rate of viscosity increase and excellent storage stability. On the other hand, the curable compositions of Comparative Examples 1 to 3 and Comparative Example 6 are poor in curability. Furthermore, the curable compositions of Comparative Examples 4 and 5 gelled due to the large rate of viscosity increase, and were therefore poor in storage stability.

Claims

1. A curable composition used as an adhesive for an optical element fixing material or a sealing material for an optical element fixing material, the curable composition containing the following components (A) and (B) (however, curable compositions containing an epoxy resin that does not contain silicon in the molecule or an oxetane resin that does not contain silicon in the molecule are excluded): Component (A): A polysilsesquioxane compound having one or more repeating units represented by the following formula (a-1), wherein the content of the repeating units represented by the formula (a-1) in the polysilsesquioxane compound (A) is 90 to 100 mol % based on all repeating units: 【Chemical 1】 [R １ is a group selected from the group consisting of an unsubstituted alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms and having a substituent selected from a halogen atom and a cyano group, an unsubstituted aryl group having 6 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms and having a substituent selected from an alkyl group, a halogen atom, and an alkoxy group. Component (B): Thermal acid generator

2. The curable composition according to claim 1, wherein the content of the repeating unit represented by formula (a-1) in the polysilsesquioxane compound (A) is 90 to 100 mol % (excluding 90 mol %) based on all repeating units.

3. A curable composition used as an adhesive for an optical element fixing material or a sealing material for an optical element fixing material, comprising the following component (A) and component (B): Component (A): A polysilsesquioxane compound having one or more repeating units represented by the following formula (a-1), wherein the content of the repeating units represented by the formula (a-1) in the polysilsesquioxane compound (A) is 100 mol % based on all repeating units: 【Chemistry 2】 [R １ is a group selected from the group consisting of an unsubstituted alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms and having a substituent selected from a halogen atom and a cyano group, an unsubstituted aryl group having 6 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms and having a substituent selected from an alkyl group, a halogen atom, and an alkoxy group. Component (B): Thermal acid generator

4. The curable composition according to any one of claims 1 to 3, further comprising the following component (C): Component (C): Silane coupling agent

5. A curable composition comprising the following components (A), (B), and (C2): Component (A): a polysilsesquioxane compound having one or more repeating units represented by the following formula (a-1): 【Chemistry 3】 [R1 is a group selected from the group consisting of an unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted alkyl group having 1 to 10 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and a substituted aryl group having 6 to 12 carbon atoms.] Component (B): Thermal acid generator Component (C2): a silane coupling agent having an acid anhydride structure in the molecule

6. The curable composition according to any one of claims 1, 3 and 5, wherein the weight average molecular weight (Mw) of component (A) is 500 to 20,000.

7. The curable composition according to claim 1 , wherein the content of the component (A) is 40 mass % or more and less than 100 mass % of the solid content of the curable composition.

8. 6. The curable composition according to claim 1, wherein the component (B) is an onium salt-based thermal acid generator.

9. 6. The curable composition according to claim 1, wherein the component (B) satisfies the following requirement (I): [Requirement (I)] The peak temperature of the maximum endothermic peak (acid generation temperature) of component (B) obtained by differential scanning calorimetry measurement at a temperature range of 30 to 300°C and a heating rate of 10°C / min is 80 to 180°C.

10. The curable composition according to claim 1 , wherein the amount of the component (B) is more than 0 parts by mass and not more than 5 parts by mass per 100 parts by mass of the component (A).

11. The curable composition according to claim 1 , further comprising a solvent, and having a solids concentration of 50% by mass or more but less than 100% by mass.

12. A cured product obtained by curing the curable composition according to any one of claims 1 to 11.

13. The cured product according to claim 12, which is a material for fixing optical elements.

14. A method of using the curable composition according to any one of claims 1 to 11 as an adhesive for fixing optical elements.

15. A method of using the curable composition according to any one of claims 1 to 11 as a sealing material for fixing optical elements.

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