JP7420610B2 - Curable composition, cured product, and method of using the curable composition - Google Patents

Description

The present invention provides a curable composition with excellent curability, a cured product obtained by curing the curable composition, and an adhesive for an optical element fixing material or a sealant for an optical element fixing material using the curable composition. Concerning how to use it as a material.

In the past, curable compositions have been variously improved depending on their uses, and have been widely used industrially as raw materials for optical parts and molded bodies, adhesives, coating agents, and the like.
In addition, curable compositions have also attracted attention as compositions for optical device fixing materials, such as adhesives for optical device fixing materials and sealing materials for optical device fixing materials.

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 whose peak wavelength is shorter have been developed and widely used. The brightness of such light-emitting elements with short peak wavelengths of light emission has progressed dramatically, and as a result, the amount of heat generated by optical elements tends to further increase.

However, with the increase in brightness of optical devices in recent years, the cured product of the composition for optical device fixing materials is exposed to higher energy light and higher temperature heat generated from optical devices for a long time, resulting in a decrease in adhesive strength. A problem arose.

In order to solve this problem, Patent Documents 1 to 3 propose optical element fixing material compositions containing a polysilsesquioxane compound as a main component.
When fixing an optical element or the like using a composition for an optical element fixing material, the composition for an optical element fixing material is usually heated and cured.
However, when using optical element fixing material compositions with poor curability, it is necessary to lengthen the heating time or increase the heating temperature, which may cause deterioration of the optical element and surrounding components, or cause the product to deteriorate. There was a risk that the manufacturing efficiency of the product would be reduced.

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 describes that the condensation reaction type silicone composition has excellent various properties as well as excellent curability (initial curability).

Japanese Patent Application Publication No. 2004-359933 Japanese Patent Application Publication No. 2005-263869 JP2006-328231A WO2017/122762

As mentioned above, the condensation reaction type silicone composition described in Patent Document 4 is said to be excellent in various properties and also in curability.
However, the curing conditions described in the examples of Patent Document 4 are heating at 120°C for 1 hour and then heating at 150°C for 3 hours, and there is a demand for a curable composition with even better curability. It had been.

The present invention has been made in view of the above-mentioned state of the prior art, and provides a curable composition with excellent curability, a cured product obtained by curing the curable composition, and a curable composition comprising: An object of the present invention is to provide a method for use 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 performed under predetermined conditions, the viscosity increases in a shorter time and the material is finally cured.

In order to solve the above problems, the present inventors have conducted extensive studies on curable compositions containing polysilsesquioxane compounds.
As a result, it was discovered that a curable composition containing a polysilsesquioxane compound and a carboxyl group-containing compound having two or more carboxyl groups in the molecule has excellent curability, and the present invention was completed.

According to the present invention, the following curable compositions [1] to [9], cured products [10] and [11], and methods of using the curable compositions [12] and [13] are provided. be done.
[1] A curable composition containing the following components (A) and (B).
Component (A): polysilsesquioxane compound having one or more repeating units represented by the following formula (a-1)

[R ¹ is an unsubstituted alkyl group having 1 to 10 carbon atoms, a substituent alkyl group having 1 to 10 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and a substituent having 6 to 12 carbon atoms; It is a group selected from the group consisting of 6 to 12 aryl groups. ]
(B) Component: Carboxy group-containing compound having two or more carboxy groups in the molecule [2] The amount of the repeating unit represented by formula (a-1) in component (A) is the total number of repeats of component (A). The curable composition according to [1], which is 70 to 100 mol% in units.
[3] The curable composition according to [1] or [2], wherein component (A) has a weight average molecular weight (Mw) of 500 to 20,000.
[4] The curable composition according to any one of [1] to [3], wherein the content of component (A) is 40% by mass or more and less than 100% by mass based on the solid content of the curable composition.
[5] The curable composition according to any one of [1] to [4], wherein component (B) has a molecular weight of 90 to 200.
[6] Component (B) is at least one selected from the group consisting of aliphatic polycarboxylic acids, alicyclic polycarboxylic acids, aromatic polycarboxylic acids, and oxypolycarboxylic acids, [ The curable composition according to any one of [1] to [5].
[7] The curable composition according to any one of [1] to [6], wherein the content of component (B) is more than 0 parts by mass and 10 parts by mass or less based on 100 parts by mass of component (A). thing.
[8] The curable composition according to any one of [1] to [7], further containing the following component (C).
Component (C): silane coupling agent [9] Curable according to any one of [1] to [8], further containing a solvent and having a solid content concentration of 50% by mass or more and less than 100% by mass. Composition.
[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.

According to the present invention, a curable composition having excellent curability, a cured product obtained by curing the curable composition, and the curable composition can be used as an adhesive for an optical element fixing material or as an optical element fixing material. A method for use as an encapsulant is provided.

Hereinafter, the present invention will be explained in detail by dividing into 1) a curable composition, 2) a cured product, and 3) a method of using the curable composition.

1) Curable composition The curable composition of the present invention contains the following component (A) and component (B).
(A) Component: Polysilsesquioxane compound having one or more repeating units represented by the above formula (a-1) Component (B): Carboxy group-containing having two or more carboxy groups in the molecule Compound

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

In formula (a-1), R ¹ is 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 substituent-containing aryl group having 6 to 12 carbon atoms.

The number of carbon atoms in the "unsubstituted alkyl group having 1 to 10 carbon atoms" represented by R ¹ is preferably 1 to 6, more preferably 1 to 3.
Examples of "unsubstituted alkyl group having 1 to 10 carbon atoms" include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n- Examples include pentyl group, n-hexyl group, n-octyl group, n-nonyl group, n-decyl group and the like.

The carbon number of "the alkyl group having 1 to 10 carbon atoms having a substituent" represented by R ¹ is preferably 1 to 6, more preferably 1 to 3. Note that this number of carbon atoms means the number of carbon atoms in the portion excluding substituents (alkyl group portion). Therefore, when R ¹ is "a substituent-containing alkyl group having 1 to 10 carbon atoms", the number of carbon atoms in R ¹ may exceed 10.
Examples of the alkyl group of the "substituted alkyl group having 1 to 10 carbon atoms" include those shown as "unsubstituted alkyl group having 1 to 10 carbon atoms".

The number of atoms of the substituent in the "substituent-containing alkyl group having 1 to 10 carbon atoms" (excluding the number of hydrogen atoms) is usually 1 to 30, preferably 1 to 20.
Examples of the substituent of the "substituent-containing alkyl group having 1 to 10 carbon atoms" include halogen atoms such as fluorine atom, chlorine atom, and bromine atom; cyano group; group represented by the formula: OG; and the like.
Here, G represents a hydroxyl protecting group. There are no particular restrictions on the hydroxyl-protecting group, and examples thereof include known protecting groups known as hydroxyl-protecting groups. For example, acyl-based protecting groups; silyl-based protecting groups such as trimethylsilyl group, triethylsilyl group, t-butyldimethylsilyl group, t-butyldiphenylsilyl group; methoxymethyl group, methoxyethoxymethyl group, 1-ethoxyethyl group , tetrahydropyran-2-yl group, tetrahydrofuran-2-yl group, etc.; alkoxycarbonyl-based protecting groups such as t-butoxycarbonyl group; methyl group, ethyl group, t-butyl group, octyl group , allyl group, triphenylmethyl group, benzyl group, p-methoxybenzyl group, fluorenyl group, trityl group, benzhydryl group; and the like.

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

The number of carbon atoms in "aryl group having 6 to 12 carbon atoms and having a substituent" represented by R ¹ is preferably 6. Note that this number of carbon atoms means the number of carbon atoms in the portion excluding substituents (the aryl group portion). Therefore, when R ¹ is "an aryl group having a substituent and having 6 to 12 carbon atoms", the number of carbon atoms in R ¹ may exceed 12.
Examples of the aryl group of the "substituted aryl group having 6 to 12 carbon atoms" include those shown as "unsubstituted aryl group having 6 to 12 carbon atoms".

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

Among these, R ¹ is an unsubstituted alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms having a fluorine atom, an alkyl group having 1 to 10 carbon atoms having a cyano group, or an unsubstituted alkyl group having 1 to 10 carbon atoms. An aryl group having 6 to 12 carbon atoms is preferred.

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

By using the polysilsesquioxane compound (A) in which R ¹ is an alkyl group having 1 to 10 carbon atoms and having a fluorine atom, a curable composition or cured product with a low refractive index can be easily obtained.

By using a polysilsesquioxane compound (A) in which R ¹ is an alkyl group having 1 to 10 carbon atoms and having a cyano group, a curable composition that provides a cured product with excellent adhesiveness to highly polar adherends can be obtained. It becomes easier to obtain.

By using the polysilsesquioxane compound (A) in which R ¹ is an unsubstituted aryl group having 6 to 12 carbon atoms, a curable composition or cured product with a high refractive index can be easily obtained.

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%, based on all repeating units. More preferably 90 to 100 mol%.
The content ratio of the repeating unit represented by the formula (a-1) in the polysilsesquioxane compound (A) can be determined by measuring ²⁹ Si-NMR, as described below.

The repeating unit represented by the formula (a-1) is represented by the following formula (a-2). In this specification, O _1/2 represents that an oxygen atom is shared with an adjacent repeating unit.

As shown in formula (a-2), the polysilsesquioxane compound (A) has three oxygen atoms bonded to a silicon atom, which are generally collectively referred to as T sites, and other groups (R ¹ ). It has a partial structure in which one is combined.
Examples of the T site contained in the polysilsesquioxane compound (A) include those represented by the following formulas (a-3) to (a-5).

In formulas (a-3) to (a-5), R ¹ represents the same meaning as above. R ² represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms for R ² include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, and t-butyl group. All of the plurality of ^R2s may be the same or different. Furthermore, in the above formulas (a-3) to (a-5), * is bonded to a Si atom.

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

By measuring ²⁹ Si-NMR of the polysilsesquioxane compound (A) in a solution state, the T3 site represented by the formula (a-3), the T2 site represented by the formula (a-4), and the formula The content ratio of the T1 site shown in (a-5) can be determined.
The polysilsesquioxane compound (A) used in the present invention preferably contains 10 to 45 mol% of T2 sites, more preferably 15 to 40 mol%, from the viewpoint of improving the adhesiveness of the cured product. , 20 to 35 mol% is even more preferred.
In addition, from the viewpoint of obtaining a cured product that is hard and has excellent heat resistance, the polysilsesquioxane compound (A) used in the present invention preferably contains 50 to 90 mol% of T3 sites, and preferably contains 55 to 85 mol% of T3 sites. Those containing 60 to 80 mol% are even more preferred.

The polysilsesquioxane compound (A) may have one type of R ¹ (homopolymer) or may have two or more types of R ¹ (copolymer).

When the polysilsesquioxane compound (A) is a copolymer, the polysilsesquioxane compound (A) can be any of a random copolymer, a block copolymer, a graft copolymer, an alternating copolymer, etc. However, from the viewpoint of ease of manufacture, etc., a random copolymer is preferable.
Further, 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. .

The weight average molecular weight (Mw) of the polysilsesquioxane compound (A) is usually 500 to 20,000, preferably 1,000 to 15,000, 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 provides a cured product with better heat resistance and adhesiveness.

The molecular weight distribution (Mw/Mn) of the polysilsesquioxane compound (A) is not particularly limited, but is usually 1.0 to 10.0, preferably 1.1 to 6.0. By using a polysilsesquioxane compound (A) having a molecular weight distribution (Mw/Mn) within the above range, a curable composition that provides a cured product with better heat resistance and adhesiveness can be easily obtained.
The mass average molecular weight (Mw) and the number average molecular weight (Mn) can be determined, for example, as standard polystyrene equivalent values by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

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) is preferably 40% by mass or more and less than 100% by mass, more preferably 48 to 95% by mass, even more preferably 56% by mass, based on the solid content of the curable composition. ~90% by mass.
In the present invention, "solid content" refers to components other than the solvent in the curable composition.

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).

In the formula, R ¹ represents the same meaning as above. R ³ represents an alkyl group having 1 to 10 carbon atoms, X ¹ represents a halogen atom, and p represents an integer of 0 to 3. The plurality of R ³ and the plurality of X ¹ may be the same or different from each other.
Examples of the alkyl group having 1 to 10 carbon atoms for R ³ include those shown as the alkyl group having 1 to 10 carbon atoms for R ² .
Examples of the halogen atom for X ¹ include a chlorine atom and a bromine atom.

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

Substituted alkyltrialkoxysilane compounds such as 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 2-cyanoethyltrimethoxysilane, 2-cyanoethyltriethoxysilane;
3,3,3-trifluoropropylchlorodimethoxysilane, 3,3,3-trifluoropropylchlorodiethoxysilane, 3,3,3-trifluoropropyldichloromethoxysilane, 3,3,3-trifluoropropyldichloro Substituted alkylhalogenoalkoxysilane compounds such as ethoxysilane, 2-cyanoethylchlorodimethoxysilane, 2-cyanoethylchlorodiethoxysilane, 2-cyanoethyldichloromethoxysilane, 2-cyanoethyldichloroethoxysilane;
Substituted alkyltrihalogenosilane compounds such as 3,3,3-trifluoropropyltrichlorosilane and 2-cyanoethyltrichlorosilane;

Phenyltrialkoxysilane compounds with or without substituents, such as phenyltrimethoxysilane and 4-methoxyphenyltrimethoxysilane;
Phenylhalogenoalkoxysilane compounds with or without substituents, such as phenylchlorodimethoxysilane, phenyldichloromethoxysilane, 4-methoxyphenylchlorodimethoxysilane, 4-methoxyphenyldichloromethoxysilane;
Examples include phenyltrihalogenosilane compounds with or without substituents, such as phenyltrichlorosilane and 4-methoxyphenyltrichlorosilane.
These silane compounds (1) can be used alone or in combination of two or more.

The method of polycondensing the silane compound (1) is not particularly limited. For example, a method may be mentioned in which a predetermined amount of a polycondensation catalyst is added to the silane compound (1) in a solvent or without a solvent, and the mixture is stirred at a predetermined temperature. More specifically, (a) a method in which a predetermined amount of an acid catalyst is added to the silane compound (1) and stirred at a predetermined temperature; (b) a method in which a predetermined amount of a base catalyst is added to the silane compound (1). , a method of stirring at a predetermined temperature, (c) adding a predetermined amount of acid catalyst to the silane compound (1), stirring at a predetermined temperature, and then adding an excess amount of a base catalyst to make the reaction system basic. , a method of stirring at a predetermined temperature, and the like. Among these, method (a) or (c) is preferred because the desired polysilsesquioxane compound (A) can be obtained efficiently.

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

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

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 mol of the silane compound (1).

When using a solvent during polycondensation, the solvent to be used can be appropriately selected depending on the type of silane compound (1), etc. For example, 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. Alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, s-butyl alcohol, and t-butyl alcohol; and the like. These solvents can be used alone or in combination of two or more. In addition, when employing the method (c) above, after performing a 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) are added to the reaction solution, A polycondensation reaction may be further carried out under basic conditions.

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

The temperature at which the silane compound (1) is polycondensed is usually from 0°C to the boiling point of the solvent used, preferably from 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 becomes too high, it becomes difficult to suppress gelation. The reaction is usually completed in 30 minutes to 30 hours.

Note that depending on the type of monomer used, it may be difficult to increase the molecular weight. For example, monomers in which R ¹ is an alkyl group having a fluorine atom tend to be less reactive than monomers in which R ¹ is a normal alkyl group. In such a case, the polysilsesquioxane compound (A) having the desired molecular weight can be easily obtained by reducing the amount of catalyst and carrying out the reaction under mild conditions for a long time.

After the reaction is complete, if an acid catalyst is used, the reaction solution is neutralized by adding an alkaline aqueous solution such as sodium hydrogen carbonate, or if a base catalyst is used, the reaction solution is neutralized by adding an acid such as hydrochloric acid to the reaction solution. The desired polysilsesquioxane compound (A) can be obtained by neutralizing by adding and removing the salts generated at that time by filtration or washing with water.

When producing the polysilsesquioxane compound (A) by the above method, the portion of OR ³ or X ¹ of the silane compound (1) in which dealcoholization etc. did not occur is ) remains in the Therefore, in the polysilsesquioxane compound (A), in addition to the T site shown by the above formula (a-3), there are T sites shown by the above formula (a-4) and formula (a-5). May be included.

[(B) component]
Component (B) constituting the curable composition of the present invention is a carboxyl group-containing compound having two or more carboxyl groups in the molecule (hereinafter sometimes referred to as "polyhydric carboxylic acid (B)"). be.
Since the curable composition of the present invention contains polyhydric carboxylic acid (B), it has excellent curability.
Furthermore, the use of polyhydric carboxylic acid (B) may improve the adhesiveness of the cured product.

The molecular weight of the polyhydric carboxylic acid (B) is usually 90 to 200, preferably 90 to 150, more preferably 90 to 104.
By setting the molecular weight of the polyhydric carboxylic acid (B) to 200 or less, the curing reaction can be efficiently promoted and high adhesive strength can be maintained. Furthermore, by setting the molecular weight of the polyvalent carboxylic acid (B) to 90 or more, the adhesiveness of the cured product is improved.
The number of carboxy groups in the polyvalent carboxylic acid (B) is usually 2 to 4, preferably 2 to 3, and more preferably 2 per molecule.
Even if a monohydric carboxylic acid is used, it is difficult to obtain the effects of the present invention. Furthermore, the curability of the curable composition and the adhesiveness of the cured product may be reduced.

Examples of the polycarboxylic acid (B) include aliphatic polycarboxylic acids, alicyclic polycarboxylic acids, aromatic polycarboxylic acids, oxypolycarboxylic acids, and the like.

An aliphatic polycarboxylic acid is a compound having an aliphatic skeleton (excluding an alicyclic skeleton) and two or more carboxy groups in the molecule.
Examples of the aliphatic polycarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, itaconic acid, and the like.

Alicyclic polyhydric carboxylic acid is a compound having an alicyclic skeleton and two or more carboxy groups in the molecule.
Examples of the alicyclic polycarboxylic acid include hexahydrophthalic acid and tetrahydrophthalic acid.

Aromatic polyhydric carboxylic acid is a compound having an aromatic skeleton and two or more carboxy groups in the molecule.
Examples of aromatic polycarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid.

Oxypolyhydric carboxylic acid is a compound having a hydroxy group and two or more carboxy groups in the molecule.
Examples of the oxypolycarboxylic acid include tartronic acid, malic acid, tartaric acid, citric acid, and the like.

Among these, aliphatic polycarboxylic acids are preferable as polycarboxylic acids (B) because they can efficiently promote the curing reaction and maintain high adhesive strength, and oxalic acid, malonic acid, succinic acid, and glutaric acid are preferred as polycarboxylic acids (B). , adipic acid is more preferred, and oxalic acid is particularly preferred.

The polyhydric carboxylic acids (B) can be used alone or in combination of two or more.
The content of the polyhydric carboxylic acid (B) is usually more than 0 parts by mass and 10 parts by mass or less, preferably 0.01 to 8 parts by mass, based on 100 parts by mass of the polysilsesquioxane compound (A). More preferably 0.05 to 6 parts by weight, still more preferably 0.1 to 4 parts by weight, even more preferably 0.3 to 3 parts by weight, particularly preferably 0.7 to 2 parts by weight. It is.
If the polyhydric carboxylic acid (B) is too large, the adhesiveness of the cured product may decrease.

[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 form a cured product with better adhesive properties.
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.
A functional group refers to a group that is reactive with other compounds (mainly organic substances), such as a group 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. ; acid anhydride group; vinyl group; allyl group; epoxy group; (meth)acrylic group; mercapto group; and the like.
In the present invention, the silane coupling agents can be used alone or in combination of two or more.
When the curable composition of the present invention contains a silane coupling agent, the content 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, based on 100 parts by mass of the polysilsesquioxane compound (A).

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 preferable.

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 with better heat resistance and adhesiveness.

Examples of the silane coupling agent having a nitrogen atom in the molecule include a trialkoxysilane compound represented by the following formula (c-1), a dialkoxyalkylsilane compound represented by the formula (c-2), or a dialkoxysilane compound represented by the formula (c-2). Examples include arylsilane compounds.

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, and a t-butoxy group. The plurality of ^Ras may be the same or different.
R ^b is an alkyl group having 1 to 6 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group; or phenyl group, 4-chlorophenyl group, 4- Represents an aryl group with or without a substituent, such as a methylphenyl group or a 1-naphthyl group.

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

Among the compounds represented by the above formula (c-1) or (c-2), when R ^c is an organic group bonded to another silicon atom-containing group, the compound has an isocyanurate skeleton. Examples include silane coupling agents (isocyanurate-based silane coupling agents) and silane coupling agents having a urea skeleton (urea-based silane coupling agents).

Among these, as the silane coupling agent having a nitrogen atom in the molecule, isocyanurate-based silane coupling agents and urea-based silane coupling agents are preferred, as they tend to yield cured products with excellent adhesive properties; , those having four or more alkoxy groups bonded to silicon atoms in the molecule are preferred.
Having 4 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 4 or more.

Examples of the isocyanurate-based silane coupling agent having four or more alkoxy groups bonded to a silicon atom include a compound represented by the following formula (c-3). Examples of the urea-based silane coupling agent having four or more alkoxy groups bonded to a silicon atom include a compound represented by the following formula (c-4).

In the formula, R ^a represents 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.

Among these, 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 a combination of the above-mentioned isocyanurate compound and urea compound are preferably used.

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 amount is equal to the amount of the above component (A) and the silane coupling agent having a nitrogen atom in the molecule. The mass ratio of the silane coupling agent [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, still more preferably 100:3 to 100:40, particularly preferably 100:5 to 100:35.
A cured product of a curable composition containing component (A) and a silane coupling agent having a nitrogen atom in the molecule in such a ratio has better heat resistance and adhesiveness.

A silane coupling agent having an acid anhydride structure in its molecule is an organosilicon compound having both a group having an acid anhydride structure and a hydrolyzable group in one molecule. Specifically, a compound represented by the following formula (c-5) may be mentioned.

In the formula, Q represents a group having an acid anhydride structure, R ^d represents an alkyl group having 1 to 6 carbon atoms or a phenyl group with or without a substituent, and R ^e represents a carbon It represents an alkoxy group or a halogen atom of numbers 1 to 6, 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 may be the same or different. When k is 2 or 3, the plural ^Re may be the same or different. When i is 2 or 3, the plural Qs may be the same or different.
Examples of Q include groups represented by the following formulas, and the group represented by (Q1) is particularly preferred.

In the formula, h represents an integer from 0 to 10.

Examples of silane coupling agents having an acid anhydride structure in the molecule include 2-(trimethoxysilyl)ethyl succinic anhydride, 2-(triethoxysilyl)ethyl succinic anhydride, and 3-(trimethoxysilyl)propyl succinic anhydride. acid, tri(carbon number 1 to 6) alkoxysilyl(carbon number 2 to 8) alkyl succinic anhydride, such as 3-(triethoxysilyl)propyl succinic anhydride;
Di(C1 to C6) alkoxymethylsilyl(C2 to C8) alkylsuccinic anhydride such as 2-(dimethoxymethylsilyl)ethylsuccinic anhydride;
(C1 to C6) alkoxydimethylsilyl (C2 to C8) alkyl succinic anhydride, such as 2-(methoxydimethylsilyl)ethylsuccinic anhydride;

Trihalogenosilyl (2 to 8 carbon atoms) alkyl succinic anhydride, such as 2-(trichlorosilyl)ethyl succinic anhydride, 2-(tribromosilyl)ethyl succinic anhydride;
Dihalogenomethylsilyl (2 to 8 carbon atoms) alkyl succinic anhydride, such as 2-(dichloromethylsilyl)ethyl succinic anhydride;
Examples include halogenodimethylsilyl (2 to 8 carbon atoms) alkyl succinic anhydride such as 2-(chlorodimethylsilyl)ethyl succinic anhydride.

Among these, as a silane coupling agent having an acid anhydride structure in the molecule, tri(carbon number 1-6) alkoxysilyl(carbon number 2-8) alkyl succinic anhydride is preferred, and 3-(trimethoxysilyl ) Propyl succinic anhydride or 3-(triethoxysilyl)propyl succinic anhydride is particularly preferred.

When the curable composition of the present invention contains a silane coupling agent having an acid anhydride structure in the molecule, the content is not particularly limited, but the amount is the same as the component (A) and the silane coupling agent having an acid anhydride structure in the molecule. The mass ratio of the silane coupling agent having an acid anhydride structure [component (A): silane coupling agent having an acid anhydride structure in the molecule] is preferably 100:0.1 to 100:30, more preferably 100: The amount is 0.3 to 100:20, more preferably 100:0.5 to 100:15, and even more preferably 100:1 to 100:10.
A cured product of a curable composition containing component (A) and a silane coupling agent having an acid anhydride structure in the molecule in such proportions has better adhesive properties.

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

When fine particles are added, it may be possible to obtain a curable composition with excellent workability in the coating process. Materials for 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; aluminum silicate and silicic acid. Metal silicates such as calcium and magnesium silicate; inorganic components such as silica; silicones; organic components such as acrylic polymers; and the like.
Further, the surface of the fine particles used may be modified.

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 usually preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on component (A).

Antioxidants are added to prevent oxidative deterioration during heating. Examples of the antioxidant include phosphorus antioxidants, phenolic antioxidants, sulfur antioxidants, and the like.

Examples of phosphorus antioxidants include phosphites, oxaphosphaphenanthrene oxides, and the like. Examples of phenolic antioxidants include monophenols, bisphenols, and polymeric phenols. Examples of the sulfur-based antioxidant include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, and the like.

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 component (A).

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

A light stabilizer is added for the purpose of improving the light resistance of the resulting cured product.
Examples of the light stabilizer include 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} and the like.
These light stabilizers can be used alone or in combination of two or more. The content of the light stabilizer is usually 20% by mass or less based on component (A).

The curable composition of the present invention may contain a solvent. The solvent is not particularly limited as long as it can dissolve or disperse the components of the curable composition of the present invention.
As a solvent, acetates such as diethylene glycol monobutyl ether acetate and 1,6-hexanediol diacetate; tripropylene glycol-n-butyl ether; glycerin diglycidyl ether, butanediol diglycidyl ether, diglycidyl aniline, neopentyl glycol glycidyl ether , cyclohexanedimethanol diglycidyl ether, alkylene diglycidyl ether, polyglycol diglycidyl ether, polypropylene glycol diglycidyl ether, and other diglycidyl ethers; trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, and other triglycidyl ethers; 4 - Vinylhexene oxides such as vinylcyclohexene monooxide, vinylcyclohexene dioxide, and methylated vinylcyclohexene dioxide; and the like.
One type of solvent can be used alone or two or more types can be used in combination.

When the curable composition of the present invention contains a solvent, the content thereof is such that the solid content concentration is preferably 50% by mass or more and less than 100% by mass, more preferably 60 to 90% by mass, and even more preferably 65% by mass. The amount is ~85% by mass. When the solid content concentration is within this range, it becomes easier to obtain a curable composition that has excellent workability in the coating process.

The curable composition of the present invention can be prepared, for example, by mixing the above components (A) and (B) and, if desired, other components in a predetermined ratio and defoaming the mixture.
The mixing method and defoaming method are not particularly limited, and known methods can be used.

After the curable composition of the present invention is prepared, it is preferably stored refrigerated or frozen until it is used. By refrigerating or freezing the curable composition of the present invention, it can be stored for a long period of time.

The curable composition of the present invention contains a polysilsesquioxane compound (A) and a polycarboxylic acid (B). Therefore, the curable composition of the present invention has excellent curability.
The excellent curability of the curable composition of the present invention can be confirmed, for example, by the method described in the Examples.
That is, 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 Co., Ltd., product name "Madoka"), the stirring torque increases. . Therefore, by measuring the time it takes for the stirring torque to reach 0.049 N·cm, the curability can be quantified.
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.

As mentioned above, the curable composition of the present invention has excellent curability. Therefore, by using the curable composition of the present invention, the working time can be shortened compared to the case where conventional curable compositions are used.

2) Cured product The cured product of the present invention is obtained by curing the curable composition of the present invention.
A method for curing the curable composition of the present invention includes 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.

The cured product of the present invention preferably has excellent heat resistance and adhesive properties.
The heat resistance and adhesiveness of the cured product can be confirmed, 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 applied surface is placed on an adherend, the composition is pressed, and the composition is heated and cured. This was left on the measurement stage of a bond tester preheated to a predetermined temperature (for example, 100°C) for 30 seconds, and the adhesive was measured horizontally (shearing direction) from a position 100 μm above the adherend. Apply stress and measure the adhesive strength between the test piece and the adherend.

The adhesive strength of the cured product of the present invention is preferably 15 N/4 mm ² or more, more preferably 25 N/4 mm ² or more, and 30 N/4 mm ² or more under the measurement conditions described in the Examples. is even more preferable.
In this specification, "4 mm ² " means "2 mm square", that is, 2 mm x 2 mm (a square with one side of 2 mm).

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 with excellent heat resistance and adhesive properties is more preferably used as an optical element fixing material.

3) Method of using 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, optical integrated circuits, and the like.

<Adhesive for optical element fixing material>
The curable composition of the present invention can be suitably used as an adhesive for an optical element fixing material.
A method for using the curable composition of the present invention as an adhesive for an optical device fixing material is to apply the composition to one or both adhesive surfaces of the materials to be bonded (optical device and its substrate, etc.). After crimping, the materials to be bonded may be hardened by heating to firmly bond the materials to be bonded. The amount of the curable composition of the present invention to be applied is not particularly limited, and may be any amount that allows the materials to be bonded to be firmly bonded together by curing. Usually, the amount is such that the thickness of the coating film of the curable composition is 0.5 to 5 μm, preferably 1 to 3 μm.

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

The heating temperature during heat curing depends 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.

<Encapsulant for optical element fixing material>
The curable composition of the present invention can be suitably used as a sealing material for an optical element fixing material.
As a method for using the curable composition of the present invention as a sealing material for an optical element fixing material, for example, the composition is molded into a desired shape to obtain a molded body containing an optical element, and then this Examples include a method of manufacturing an optical element sealing body by heating and curing the material.
The method for molding the curable composition of the present invention into a desired shape is not particularly limited, and a known molding method such as a normal transfer molding method or a casting method can be employed.

The heating temperature during heat curing depends 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.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples. However, the present invention is not limited to the following examples.

(Average molecular weight measurement)
The mass average molecular weight (Mw) and number average molecular weight (Mn) of the polysilsesquioxane compound obtained in the production example were measured using the following equipment and conditions using standard polystyrene equivalent values.
Device name: HLC-8220GPC, manufactured by Tosoh Corporation Column: TSKgelGMHXL, TSKgelGMHXL, and TSKgel2000HXL connected in sequence Solvent: Tetrahydrofuran Injection volume: 80 μl
Measurement temperature: 40℃
Flow rate: 1ml/min Detector: Differential refractometer

(Measurement of IR spectrum)
The IR spectrum of the polysilsesquioxane compound obtained in the production example was measured using a Fourier transform infrared spectrophotometer (PerkinElmer, Spectrum 100).

( ^29Si -NMR measurement)
In order to investigate the repeating unit and its amount of the polysilsesquioxane compound obtained in the production example, ²⁹ Si-NMR measurement was performed under the following conditions.
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: 5s
Total number of times: 9200 times Observation width: 30kHz

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

(Waveform processing analysis)
For each peak in the spectrum after Fourier transformation, the chemical shift was determined based on the position of the peak top, and integration was performed.

(Manufacturing example 1)
After charging 71.37 g (400 mmol) of methyltriethoxysilane into a 300 ml eggplant-shaped flask, while stirring, add 0.10 g of 35% by mass hydrochloric acid (0.10 g relative to methyltriethoxysilane) to 21.6 ml of distilled water. An aqueous solution in which .
While stirring the contents, 140 g of propyl acetate and 0.12 g of 28% by mass ammonia water (0.5 mol% relative to methyltriethoxysilane) were added thereto, and the mixture was stirred as it was at 70° C. for 3 hours.
After the reaction solution was allowed to cool to room temperature, purified water was added thereto to perform a liquid separation treatment, and this operation was repeated until the pH of the aqueous layer reached 7. The organic layer was concentrated using an evaporator, and the concentrate was vacuum-dried to obtain a 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.
IR spectrum data of PSQ(A1) is shown below.
Si-CH ₃ : 1272 cm ^-1 , 1409 cm ^-1 , Si-O: 1132 cm ^-1
Further, as a result of ²⁹ Si-NMR spectrum measurement, the ratio of peak integral values of T1, T2, and T3 was 0:24:76.

(Manufacturing example 2)
A 300 mL eggplant-shaped 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 stirred. While adding an aqueous solution obtained by dissolving 0.0675 g of 35% by mass hydrochloric acid (the amount of HCl is 0.65 mmol, 0.25 mol% with respect to the total amount of silane compounds) in 14.0 g of distilled water, The whole mixture was stirred at 30°C for 2 hours, then heated to 70°C and stirred for 20 hours.
While stirring the contents, a mixed solution of 0.0394 g of 28% by mass ammonia water (the amount of NH ₃ is 0.65 mmol) and 46.1 g of propyl acetate was added thereto to adjust the pH of the reaction solution to 6.9. The mixture was stirred at 70° C. for 40 minutes.
After the reaction solution was allowed to cool to room temperature, 50 g of propyl acetate and 100 g of water were added thereto for liquid separation treatment to obtain an organic layer containing the reaction product. Magnesium sulfate was added to this organic layer for drying. After removing magnesium sulfate by filtration, the organic layer was concentrated using an evaporator, and the resulting concentrate was then vacuum-dried 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.
IR spectrum data of PSQ (A2) is shown below.
Si-CH ₃ : 1272 cm ^-1 , 1409 cm ^-1 , Si-O: 1132 cm ^-1 , C-F: 1213 cm ^-1
Further, as a result of ²⁹ Si-NMR spectrum measurement, the ratio of peak integral values of T1, T2, and T3 was 2:27:71.

(Manufacturing 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. While stirring, 0.15 g (1.5 mmol) of phosphoric acid was added as a catalyst, and the mixture was further stirred at 25° C. for 16 hours.
After the reaction was completed, the reaction solution was concentrated to 50 ml using an evaporator, 100 ml of ethyl acetate was added to the concentrate, and the mixture was neutralized with a saturated aqueous sodium hydrogen carbonate solution. After standing still for a while, the organic layer was separated. The organic layer was then washed twice with distilled water and then dried over anhydrous magnesium sulfate. After filtering off magnesium sulfate, the filtrate was concentrated to 50 ml using an evaporator, the resulting concentrate was dropped into a large amount of n-hexane to precipitate it, and the precipitate was separated by decantation. The obtained precipitate was recovered by dissolving it in methyl ethyl ketone (MEK), and the solvent was distilled off under reduced pressure using an evaporator. By vacuum drying the residue, a polysilsesquioxane compound (A3) [PSQ (A3)] was obtained. The mass average molecular weight (Mw) of PSQ (A3) was 1,870, and the molecular weight distribution (Mw/Mn) was 1.42.
IR spectrum data of PSQ (A3) is shown below.
Si-Ph: 698 cm ^-1 , 740 cm ^-1 , Si-O: 1132 cm ^-1 , -CN: 2259 cm ^-1
Further, as a result of ²⁹ Si-NMR spectrum measurement, the ratio of peak integral values of T1, T2, and T3 was 0:33:67.

(Manufacturing example 4)
After charging 28.91 g (145.8 mmol) of phenyltrimethoxysilane into a 300 ml eggplant-shaped flask, while stirring, add 0.0376 g of 35% by mass hydrochloric acid (based on phenyltrimethoxysilane) to 7.874 g of distilled water. An aqueous solution in which HCl (0.25 mol %) was dissolved was added, and the entire volume was stirred at 30° C. for 2 hours, then heated to 70° C. and stirred for 5 hours.
After the reaction solution was allowed to cool to room temperature, 50 g of propyl acetate and 100 g of water were added thereto for liquid separation treatment to obtain an organic layer containing the reaction product. Magnesium sulfate was added to this organic layer for drying. After removing magnesium sulfate by filtration, the organic layer was concentrated using an evaporator, and the resulting concentrate was then vacuum-dried to obtain a polysilsesquioxane compound (A4). The mass average molecular weight (Mw) of PSQ (A4) was 1,100, and the molecular weight distribution (Mw/Mn) was 1.20.
IR spectrum data of PSQ (A4) is shown below.
Si-Ph: 698cm ^-1 , 740cm ^-1 , Si-O: 1132cm ^-1
Further, as a result of ²⁹ Si-NMR spectrum measurement, the ratio of peak integral values of T1, T2, and T3 was 5:53:42.

The compounds used in Examples and Comparative Examples are shown below.
(A component)
PSQ (A1) ~ (A4)

(Component B and comparative compound)
Polyvalent carboxylic acid (B1): Oxalic acid polyvalent carboxylic acid (B2): Adipic acid polyvalent carboxylic acid (B3): Citric acid polyvalent carboxylic acid (B4): Phthalic acid polyvalent carboxylic acid (B5): Cyclohexanedicarboxylic acid Acid carboxyl group-containing compound (X1): Formic acid carboxyl group-containing compound (X2): Propionic acid carboxyl group-containing compound (X3): Butyric acid

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

(Example 1)
A mixed solvent of diethylene glycol monobutyl ether acetate: tripropylene glycol-n-butyl ether = 40:60 (mass ratio) was added to 100 parts by mass of PSQ (A1), and the whole was stirred. To this, add 0.5 parts of polyhydric carboxylic acid (B1) (added as a 20% by mass methanol solution), 30 parts by mass of silane coupling agent (C1), and 3 parts by mass of silane coupling agent (C2), and add A curable composition was obtained by thoroughly mixing and defoaming.

(Examples 2 to 14, Comparative Examples 1 to 5)
A curable composition was obtained in the same manner as in Example 1, except that each component was changed to those shown in Table 1.

The following measurements and tests were conducted using the curable compositions obtained in Examples and Comparative Examples. The results are shown in Table 1.

[Cureability evaluation]
Using an automatic curing time measuring device "Madoka" (manufactured by Cyber Co., Ltd.), the curing time of the curable composition was measured by the following method.
0.30 mL of the sample was placed on a stainless steel plate heated to 150°C and stirred. Since the stirring torque increases over time, the time (seconds) until the stirring torque reaches 0.049 N·cm was measured. The stirring conditions are as follows.
・Rotation speed of stirring blade: 200 rpm
・Revolution speed of stirring blade: 80 rpm
・Gap (distance between heating plate and stirring blade): 0.3mm

[Adhesive strength evaluation]
The curable compositions obtained in Examples and Comparative Examples were each applied to the mirror surface of a square silicon chip with a side length of 2 mm (area: 4 mm ² ) to a thickness of about 2 μm, The coated surface was placed on an adherend (silver-plated copper plate) and pressed. Thereafter, it was cured by heat treatment at 130° C. for 2 hours to obtain an adherend with a test piece attached. The adherend with the test piece was left on the measurement stage of a bond tester (manufactured by Dage, series 4000) preheated to 100°C for 30 seconds, and the test piece was measured at a speed of 200 μm/cm from a height of 100 μm from the adherend. Stress was applied to the adhesive surface in the horizontal direction (shear direction) at s, and the adhesive force (N/4 mm ² ) between the test piece and the adherend at 100° C. was measured.

The following can be understood from the above examples and comparative examples.
The curable compositions of Examples 1 to 14 exhibited excellent curability, with cured products being obtained in a short time of 1000 seconds or less in the curability evaluation test.
On the other hand, the curable compositions of Comparative Examples 1 to 7 have poor curability.

Claims (11)

A curable composition used as an adhesive for an optical element fixing material or a sealing material for an optical element fixing material,
A curable composition containing the following component (A) and component (B).
Component (A): polysilsesquioxane compound having one or more repeating units represented by the following formula (a-1)

[R ¹ is an unsubstituted alkyl group having 1 to 10 carbon atoms, a substituent alkyl group having 1 to 10 carbon atoms, an unsubstituted aryl group having 6 to 12 carbon atoms, and a substituent having 6 to 12 carbon atoms; It is a group selected from the group consisting of 6 to 12 aryl groups. ]
(B) Component: Carboxy group-containing compound having two or more carboxy groups in the molecule The curable composition according to claim 1, wherein the amount of the repeating unit represented by formula (a-1) in component (A) is 70 to 100 mol% of the total repeating units of component (A). The curable composition according to claim 1 or 2, wherein the weight average molecular weight (Mw) of component (A) is 500 to 20,000. The curable composition according to any one of claims 1 to 3, wherein the content of component (A) is 40% by mass or more and less than 100% by mass based on the solid content of the curable composition. The curable composition according to any one of claims 1 to 4, wherein component (B) has a molecular weight of 90 to 200. Component (B) is at least one selected from the group consisting of aliphatic polycarboxylic acids, alicyclic polycarboxylic acids, aromatic polycarboxylic acids, and oxypolycarboxylic acids. 5. The curable composition according to any one of 5. The curable composition according to any one of claims 1 to 6, wherein the content of component (B) is more than 0 parts by mass and 10 parts by mass or less based on 100 parts by mass of component (A). The curable composition according to any one of claims 1 to 7, further comprising the following component (C).
(C) Component: Silane coupling agent The curable composition according to any one of claims 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. A cured product obtained by curing the curable composition according to any one of claims 1 to 9. The cured product according to claim 10, which is an optical element fixing material.