TWI846961B - Curable composition, cured product, and method of using the curable composition - Google Patents

Abstract

The present invention is a curable composition containing the following (A) components and (C) components, a cured product formed by curing the curable composition, and a method of using the curable composition as an adhesive for optical element fixing material or a sealing material for optical element fixing material. The curable composition of the present invention has a high refractive index and is suitable for use in the optical field. (A) component: has the following formula (a-1) [R ¹ represents an unsubstituted aryl group having 6 to 12 carbon atoms, or a substituted aryl group having 6 to 12 carbon atoms] a repeating unit [repeating unit (1)]; and having the following formula (a-2): A polysilsesquioxane compound having a repeating unit [repeating unit (2)] represented by [R ² represents an unsubstituted alkyl group having 1 to 10 carbon atoms or a substituted alkyl group having 1 to 10 carbon atoms], and satisfying the specific requirements of the relevant molecular structure. (C) Component: silane coupling agent.

Description

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

The present invention relates to a curable composition having a high refractive index and being suitable for use in the optical field, 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.

It is known that curable compositions have been improved in various ways according to their uses, and are widely used in the industry as raw materials for optical parts and molded bodies, adhesives, coatings, etc. Furthermore, curable compositions are attracting attention for use as compositions for optical component fixing materials such as adhesives for optical component fixing materials and sealing materials for optical component fixing materials.

Optical components include: various lasers such as semiconductor lasers (LD), light-emitting diodes (LEDs) and other light-emitting components, light-receiving components, composite optical components, optical integrated circuits, etc. In recent years, optical components with shorter peak wavelengths of blue light and white light have been developed and widely used. The high brightness of these light-emitting components with shorter peak wavelengths has greatly improved, and with this phenomenon, the heat generated by the optical components tends to increase.

However, with the recent increase in the brightness of optical components, the cured optical component fixing material composition is exposed to higher energy light and higher temperature heat generated by the optical component for a long time, which may cause a problem of reduced adhesion.

To solve this problem, patent documents 1 to 3 propose a composition for optical element fixing material having a polysilsesquioxane compound as a main component.

However, when using a curable composition to fix an optical element, etc., in order to improve the light extraction efficiency, a curable composition with an appropriate refractive index is sometimes selected in accordance with the refractive index of the surrounding components. For example, in order to suppress reflection at the interface between the sealant and the fixing material to improve the light extraction efficiency, it is best that the difference between the refractive index of the sealant and the fixing material is small. Therefore, when using a sealant with a higher refractive index, it is necessary to use a curable composition with a high refractive index to form the fixing material. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2004-359933 [Patent Document 2] Japanese Patent Publication No. 2005-263869 [Patent Document 3] Japanese Patent Publication No. 2006-328231

(The problem that the invention wants to solve)

The present invention is made in view of the above-mentioned known technical facts, and its purpose is to provide: a curable composition with a high refractive index and suitable for use in the optical field, a cured product formed by curing the curable composition, and a method of using the curable composition as an adhesive for optical element fixing material or a sealing material for optical element fixing material. (Means for solving the problem)

In order to solve the above problems, the inventors of the present invention have conducted in-depth research on curable compositions containing polysilsesquioxane compounds. The results show that: (i) By using a polysilsesquioxane compound containing a relatively high number of aromatic groups as the polysilsesquioxane compound, a high refractive index curable composition can be obtained; (ii) The curable composition containing a polysilsesquioxane compound containing a relatively high number of aromatic groups may cause cracking of the cured product; (iii) The curable composition containing a polysilsesquioxane compound containing a relatively high number of aromatic groups may cause poor adhesion of the cured product; (iv) By adjusting the amount of aromatic groups in the polysilsesquioxane compound, introducing a specific molecular structure into the polysilsesquioxane compound, and adding a silane coupling agent to the curable composition, the above problems (ii) and (iii) can be solved, and the present invention is thus completed.

Therefore, according to the present invention, the following curable compositions [1] to [7], cured products [8] and [9], and methods of using the curable compositions [10] and [11] are provided.

[1] A curable composition comprising the following components (A) and (C): Component (A): having the following formula (a-1):

[Chemistry 1]

[R ¹ represents an unsubstituted aryl group having 6 to 12 carbon atoms, or a substituted aryl group having 6 to 12 carbon atoms] a repeating unit [repeating unit (1)]; and having the following formula (a-2):

[Chemistry 2]

A polysilsesquioxane compound having a repeating unit [repeating unit (2)] represented by [ ^R2 represents an unsubstituted alkyl group having 1 to 10 carbon atoms or a substituted alkyl group having 1 to 10 carbon atoms], and a polysilsesquioxane compound satisfying the following requirements 1 and 2: [Requirement 1] The amount of the repeating unit (1) is 40 mol% or more and less than 80 mol% relative to the total amount of the repeating unit (1) and the repeating unit (2). [Requirement 2] The amount of the T2 site is 20 to 70 mol% relative to the total amount of the T site (T1 site) represented by the following formula (a-3), the T site (T2 site) represented by the following formula (a-4), and the T site (T3 site) represented by the following formula (a-5).

[Chemistry 3]

[G represents a group represented by ^R1 or ^R2 . ^R3 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. * is bonded to a silicon atom.] Component (C): a silane coupling agent. [2] The curable composition as described in [1], wherein the mass average molecular weight (Mw) of component (A) is 500 to 25,000. [3] The curable composition as described in [1] or [2], wherein the total amount of repeating units (1) and repeating units (2) in component (A) accounts for 90 to 100 mol% of the total repeating units in component (A). [4] The curable composition as described in any one of [1] to [3], wherein the content of component (C) is 0.1 to 70 parts by mass relative to 100 parts by mass of component (A). [5] The curable composition as described in any one of [1] to [4], wherein the total amount of component (A) and component (C) accounts for 50 to 100% by weight of the solid content of the curable composition. [6] The curable composition as described in any one of [1] to [5], wherein the curable composition further contains a diluent, and the solid content concentration is greater than 60% by weight and less than 100% by weight. [7] The curable composition as described in any one of [1] to [6], wherein the refractive index (nD) at 25°C is 1.46 to 1.56. [8] A cured product obtained by curing the curable composition as described in any one of [1] to [7]. [9] The cured product as described in [8] is an optical element fixing material. [10] A method of using the curable composition described in any one of [1] to [7] as an adhesive for an optical element fixing material. [11] A method of using the curable composition described in any one of [1] to [7] as a sealing material for an optical element fixing material. [Effects of the prior art]

The present invention can provide a curable composition having a high refractive index and being suitable for use in the optical field, 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.

The present invention is described in detail below in terms of: 1) the curable composition, 2) the cured product, and 3) the method of using the curable composition.

1) Curable composition The curable composition of the present invention comprises the following components (A) and (C). Component (A): A polysilsesquioxane compound having a repeating unit represented by the above formula (a-1) and a repeating unit represented by the above formula (a-2), characterized in that the polysilsesquioxane compound satisfies the above requirements 1 and 2 [hereinafter referred to as "polysilsesquioxane compound (A)"] Component (C): Silane coupling agent

[Component (A)] The polysilsesquioxane compound (A) constituting the curable composition of the present invention has a repeating unit [repeating unit (1)] represented by the following formula (a-1).

[Chemistry 4]

[ ^R1 represents an unsubstituted aryl group having 6 to 12 carbon atoms, or a substituted aryl group having 6 to 12 carbon atoms.]

Since the repeating unit (1) has R ¹ , the polysilsesquioxane compound having the repeating unit (1) has a higher refractive index. Therefore, the curable composition of the present invention has a higher refractive index.

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

The carbon number of "aryl group with 6 to 12 carbon atoms and having a substituent" of ^R1 is preferably 6. In addition, the carbon number refers to the carbon number of the part excluding the substituent (aryl part). Therefore, when ^R1 is "aryl group with 6 to 12 carbon atoms and having a substituent", the carbon number of ^R1 may exceed 12. The aryl group of "aryl group with 6 to 12 carbon atoms and having a substituent" of ^R1 may be the same as exemplified for "aryl group with 6 to 12 carbon atoms and having no substituent".

The "aryl group having a substituent and having 6 to 12 carbon atoms" of R ¹ has a substituent having an atom number of 1 to 30 (excluding hydrogen atoms) and preferably 1 to 20. The "aryl group having a substituent and having 6 to 12 carbon atoms" of R ¹ includes, for example, alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and iso-octyl; halogen atoms such as chlorine and bromine; and alkoxy groups such as methoxy and ethoxy.

Among them, from the viewpoint of efficiently preparing a high refractive index curable composition, R ¹ is preferably an unsubstituted aryl group having 6 to 12 carbon atoms, and more preferably a phenyl group.

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

The polysilsesquioxane compound (A) may further have a repeating unit represented by the following formula (a-2) [repeating unit (2)].

[Chemistry 5]

[ ^R2 represents an unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted alkyl group having 1 to 10 carbon atoms.]

The polysilsesquioxane compound can have a high molecular weight by having a repeating unit (2), and can enhance the flexibility of the molecular chain. Therefore, the hardened material of the hardening composition of the present invention is not prone to cracking, and the hardening composition of the present invention has excellent adhesion.

The carbon number of the "unsubstituted alkyl group having 1 to 10 carbon atoms" of R ² is preferably 1 to 6, more preferably 1 to 3. Examples of the "unsubstituted alkyl group having 1 to 10 carbon atoms" of R ² include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, and n-decyl.

The "alkyl group with 1 to 10 carbon atoms having a substituent" of ^R2 preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. In addition, the carbon number refers to the carbon number of the substituent excluding the carbon atoms outside (alkyl part). Therefore, when ^R2 is "alkyl group with 1 to 10 carbon atoms having a substituent", there may be a case where the carbon number of ^R2 exceeds 10. For example, the alkyl group of "alkyl group with 1 to 10 carbon atoms having a substituent" of ^R2 is the same as the example of "alkyl group with 1 to 10 carbon atoms having no substitution".

"Alkyl group with 1 to 10 carbon atoms and having a substituent", the number of substituent atoms (excluding hydrogen atoms) is usually 1 to 30, preferably 1 to 20. "Alkyl group with 1 to 10 carbon atoms and having a substituent", the substituent can be, for example, halogen atoms such as chlorine atoms and bromine atoms; cyano group, etc.

Among them, ^R2 is preferably an unsubstituted alkyl group having 1 to 10 carbon atoms, more preferably an unsubstituted alkyl group having 1 to 6 carbon atoms, and particularly preferably an unsubstituted alkyl group having 1 to 3 carbon atoms. By using a polysilsesquioxane compound (A) in which ^R2 is an unsubstituted alkyl group having 1 to 10 carbon atoms, the molecular weight of the polysilsesquioxane compound (A) can be efficiently controlled.

The polysilsesquioxane compound (A) may have one type of R ² or may have two or more types of R ² .

The polysilsesquioxane compound (A) may be any of a random copolymer, a block copolymer, a graft copolymer, an alternating copolymer, etc., and preferably a random copolymer from the viewpoint of ease of production. Furthermore, the structure of the polysilsesquioxane compound (A) may be any of a ladder structure, a double-layer structure, a cage structure, a partially cracked cage structure, a ring structure, and a random structure.

Repeating unit (1) and repeating unit (2) are represented by the following formula (a-6):

[Chemistry 6]

[G represents a group represented by R ¹ or R ^2. R ¹ and R ² are the same as above. O _1/2 represents sharing an oxygen atom with adjacent repeating units]

As shown in formula (a-6), the polysilsesquioxane compound (A) has a partial structure in which three oxygen atoms are bonded to a silicon atom generally referred to as a "T site", and another group (group represented by G) is bonded to one oxygen atom. The T site contained in the polysilsesquioxane compound (A) can be, for example, a T site (T1 site) represented by the following formula (a-3), a T site (T2 site) represented by the following formula (a-4), and a T site (T3 site) represented by the following formula (a-5).

[Chemistry 7]

In formula (a-3), (a-4) and (a-5), G has the same meaning as above. R ³ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Examples of "alkyl group having 1 to 10 carbon atoms" of R ³ include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, etc. Multiple R ³ may be completely the same or different from each other. In the above formulas (a-3) to (a-5), * is bonded to a silicon atom.

When the polysilsesquioxane compound (A) is synthesized, the product contains more T1 sites and T2 sites at the beginning of the reaction, but as the reaction proceeds, the amount of these sites decreases, while the amount of T3 sites gradually increases. Therefore, a polysilsesquioxane compound containing a higher proportion of T1 sites or T2 sites is a low molecular weight compound, while a polysilsesquioxane compound containing a higher proportion of T3 sites is a high molecular weight compound, and the movement of the molecular chain is restricted. Furthermore, as indicated by the number of residual reactive groups (-OR ³ ), a polysilsesquioxane compound having a high ratio at the T1 site or the T2 site has sufficient reactivity, whereas a polysilsesquioxane compound having a high ratio at the T3 site tends to have poor reactivity.

The polysilsesquioxane compound (A) satisfies the above-mentioned requirement 1. That is, in the polysilsesquioxane compound (A), the amount of the repeating unit (1) is 40 mol% or more and less than 80 mol% relative to the total amount of the repeating unit (1) and the repeating unit (2). The curable composition of the present invention contains a polysilsesquioxane compound that satisfies requirement 1, and therefore has a high refractive index. In addition, since the curable composition satisfies requirement 1, the cured product is less likely to crack and has improved adhesion. From the perspective of being able to obtain these effects in a balanced manner, the amount of the repeating unit (1) relative to the total amount of the repeating unit (1) and the repeating unit (2) is preferably 45-77 mol%, more preferably 50-74 mol%, and particularly preferably 55-71 mol%.

The ratio of the repeating unit (1) to the repeating unit (2) in the polysilsesquioxane compound (A) can be obtained, for example, by measuring the ²⁹ Si-NMR of the polysilsesquioxane compound (A). The polysilsesquioxane compound (A) is soluble in various organic solvents, for example, 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 composed of two or more of these solvents. Therefore, using these solvents, the ²⁹ Si-NMR of the polysilsesquioxane compound (A) in a solution state can be measured.

The polysilsesquioxane compound (A) satisfies the above requirement 2. That is, in the polysilsesquioxane compound (A), the amount of the above T2 site is 20-70 mol% relative to the total amount of the T1 site, the T2 site and the T3 site, and the T2 site is contained more. The curable composition of the present invention satisfies requirement 2 in addition to requirement 1, so that the cured product of the curable composition of the present invention is less likely to crack and the adhesion is further improved.

That is, the curable composition containing polysilsesquioxane compounds with more T1 sites will undergo excessive hydrolysis and condensation reactions during curing, and cracks are likely to occur in the cured product due to the shrinkage during curing. Furthermore, polysilsesquioxane compounds containing more T3 sites are high molecular weight compounds with poor mobility, so the cured product of the curable composition containing such polysilsesquioxane compounds is prone to residual stress and cracks.

On the other hand, the curable composition containing polysilsesquioxane compounds with more T2 sites can be cured without excessive hydrolysis and condensation reactions, so the cured product is less likely to crack. Furthermore, since the molecular weight of the polysilsesquioxane compound containing more T2 sites is not too high and has moderate mobility, the cured product of the curable composition containing polysilsesquioxane compounds with more T2 sites is less likely to have residual stress and is less likely to crack.

From the viewpoint of easily obtaining the above-mentioned effect, the amount of the T2 site is 20-70 mol%, preferably 22-60 mol%, more preferably 24-55 mol%, and particularly preferably 26-50 mol%, relative to the total amount of the T1 site, the T2 site, and the T3 site.

Furthermore, the amount of the T1 site is preferably 0-40 mol%, more preferably 0-30 mol%, particularly preferably 0-20 mol%, and most preferably 0-10 mol% relative to the total amount of the T1 site, the T2 site, and the T3 site. By appropriately containing the T1 site in the polysilsesquioxane compound (A), a curable composition with better curability can be obtained. Furthermore, the amount of the T3 site is preferably 10-80 mol%, more preferably 20-70 mol%, and particularly preferably 30-50 mol% relative to the total amount of the T1 site, the T2 site, and the T3 site. By appropriately containing the T3 site in the polysilsesquioxane compound (A), the generation of byproducts due to the condensation reaction during curing can be suppressed.

The content ratio of the T1 site, the T2 site, and the T3 site can be determined by measuring ²⁹ Si-NMR of the polysilsesquioxane compound (A) in a solution state. For example, when acetone is used as the measurement solvent and TMS (tetramethylsilane) is used as the internal standard, in formulas (a-3) to (a-6), G is the signal derived from the silicon atom at the T site of the phenyl group, the T1 site is observed at -65 to -58 ppm, the T2 site is observed at -74 to -65 ppm, and the T3 site is observed at -82 to -75 ppm; in formulas (a-3) to (a-6), G is the signal derived from the silicon atom at the T site of the methyl group, the T1 site is observed at -50 to -46 ppm, the T2 site is observed at -61 to -52 ppm, and the T3 site is observed at -70 to -61 ppm.

The mass average molecular weight (Mw) of the polysilsesquioxane compound (A) is preferably 500-25,000, more preferably 700-20,000, particularly preferably 1,000-15,000, and most preferably 2,000-10,000. By using a polysilsesquioxane compound (A) having a mass average molecular weight (Mw) within the above range, a curable composition that is less likely to crack after curing can be easily obtained.

The molecular weight distribution (Mw/Mn) of the polysilsesquioxane compound (A) is not particularly limited, and is generally 1.0 to 10.0, preferably 1.1 to 6.0, and more preferably 1.1 to 4.0. By using a polysilsesquioxane compound (A) having a molecular weight distribution (Mw/Mn) within the above range, a curable composition that can provide a cured product with better heat resistance and adhesion can be easily obtained. The mass average molecular weight (Mw) and the number average molecular weight (Mn) can be obtained, for example, by using gel permeation chromatography (GPC) with tetrahydrofuran (THF) as a solvent and obtaining a standard polystyrene conversion value.

The total amount of the repeating units (1) and (2) in the polysilsesquioxane compound (A) is preferably 90 to 100 mol %, more preferably 95 to 100 mol %, and particularly preferably 98 to 100 mol % of the total repeating units in the polysilsesquioxane compound (A).

The 25°C refractive index (nD) of the polysilsesquioxane compound (A) is preferably 1.46 to 1.56, more preferably 1.48 to 1.55, and particularly preferably 1.50 to 1.55. When the 25°C refractive index (nD) of the polysilsesquioxane compound (A) is in the range of 1.46 to 1.56, a high refractive index curable composition and a cured product can be easily obtained. The refractive index (nD) of the polysilsesquioxane compound (A) can be measured using an Abbe refractometer.

In the present invention, the polysilsesquioxane compound (A) may be used alone or in combination of two or more.

The method for synthesizing the polysilsesquioxane compound (A) is not particularly limited. For example, the polysilsesquioxane compound (A) can be synthesized by condensing at least one of the silane compounds (1) represented by the following formula (a-7) with at least one of the silane compounds (2) represented by the following formula (a-8).

[Chemistry 8]

(In the formula, R ¹ is synonymous with the above. R ⁴ is an alkyl group having 1 to 10 carbon atoms; X ¹ is a halogen atom, and p is an integer of 0 to 3. Multiple R ⁴ and multiple X ¹ may be the same or different from each other.)

[Chemistry 9]

(In the formula, R ² is synonymous with the above. R ⁵ is an alkyl group having 1 to 10 carbon atoms; X ² is a halogen atom; q is an integer of 0 to 3. Multiple R ⁵ and multiple X ² may be the same or different from each other.)

The "alkyl group having 1 to 10 carbon atoms" for R ⁴ and R ⁵ may be the same as the "alkyl group having 1 to 10 carbon atoms" for R ^3. Examples of the halogen atom for X ¹ and X ² include a chlorine atom and a bromine atom.

Specific examples of the silane compound (1) include: Unsubstituted aryl trialkoxysilane compounds such as phenyltrimethoxysilane and phenyltriethoxysilane; Unsubstituted aryl halogen alkoxysilane compounds such as phenylchlorodimethoxysilane, phenylchlorodiethoxysilane, phenyldichloromethoxysilane, phenyldichloroethoxysilane; Unsubstituted aryl trihalogen silane compounds such as phenyltrichlorosilane; 4-methylphenyltrimethoxysilane, 4-methoxyphenyltrimethoxysilane, 4-chlorophenyltrimethoxysilane, 4-methylphenyltriethoxysilane, 4-methoxy Aryl trialkoxysilane compounds with substitution such as phenyltriethoxysilane and 4-chlorophenyltriethoxysilane; Aryl halogen alkoxysilane compounds with substitution such as 4-methylphenylchlorodimethoxysilane, 4-methoxyphenylchlorodimethoxysilane, 4-chlorophenylchlorodimethoxysilane, 4-methylphenyldichloromethoxysilane, 4-methoxyphenyldichloromethoxysilane, 4-chlorophenyldichloromethoxysilane; Aryl trihalogen silane compounds with substitution such as 4-methylphenyltrichlorosilane, 4-methoxyphenyltrichlorosilane, 4-chlorophenyltrichlorosilane, etc. The silane compounds (1) can be used alone or in combination of two or more.

Specific examples of the silane compound (2) include: Unsubstituted alkyltrialkoxysilane compounds such as methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, etc.; Unsubstituted alkylhalogenalkoxysilane compounds such as methylchlorodimethoxysilane, methylchlorodiethoxysilane, methyldichloromethoxysilane, methylbromodimethoxysilane, ethylchlorodimethoxysilane, ethylchlorodiethoxysilane, ethyldichloromethoxysilane, ethylbromodimethoxysilane, etc.; Unsubstituted alkyltrihalogensilane compounds such as methyltrichlorosilane, methyltribromosilane, ethyltrichlorosilane, ethyltribromosilane, etc.; 2- Alkyl trialkoxysilane compounds with substitution such as cyanoethyl trimethoxysilane, 3-chloropropyl trimethoxysilane, 2-cyanoethyl triethoxysilane, 3-chloropropyl triethoxysilane, etc.; Alkyl halide alkoxysilane compounds with substitution such as 2-cyanoethyl chlorodimethoxysilane, 3-chloropropyl chlorodimethoxysilane, 2-cyanoethyl chlorodiethoxysilane, 3-chloropropyl chlorodiethoxysilane, 2-cyanoethyl dichloromethoxysilane, 3-chloropropyl dichloromethoxysilane, 2-cyanoethyl dichloroethoxysilane, 3-chloropropyl dichloroethoxysilane, etc.; Alkyl trihalide silane compounds with substitution such as 2-cyanoethyl trichlorosilane, 3-chloropropyl trichlorosilane, etc. The silane compounds (2) may be used alone or in combination of two or more.

There is no particular limitation on the method of polycondensing the above-mentioned silane compound. For example, a predetermined amount of polycondensation catalyst is added to the silane compound in a solvent (or in the absence of a solvent), and then the mixture is stirred at a predetermined temperature. More specifically, for example: (a) a predetermined amount of acid catalyst is added to the silane compound, and then the mixture is stirred at a predetermined temperature; (b) a predetermined amount of alkaline catalyst is added to the silane compound, and then the mixture is stirred at a predetermined temperature; (c) a predetermined amount of acid catalyst is added to the silane compound, and after stirring at a predetermined temperature, an excess amount of alkaline catalyst is added to make the reaction system alkaline, and then the mixture is stirred at a predetermined temperature, etc. Among these, method (a) is preferred from the viewpoint of being able to efficiently obtain the target polysilsesquioxane compound (A).

The condensation catalyst used may be either an acid catalyst or an alkaline catalyst. Moreover, two or more condensation catalysts may be used in combination, but it is preferred to use at least an acid catalyst. The acid catalyst may be, for example, an inorganic acid such as phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, and nitric acid; an organic acid such as citric acid, acetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. Among them, it is preferred to select at least one from phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, citric acid, acetic acid, and methanesulfonic acid.

Examples of the alkaline 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, picolinidine, 1,4-diazabicyclo[2.2.2]octane, and imidazole; tetramethylammonium hydroxide, tetraethyl hydroxide; Organic hydroxides such as ammonium; metal alkoxides such as sodium methoxide, sodium ethoxide, sodium tert-butyloxide, potassium tert-butylate; metal hydrides such as sodium hydroxide and calcium hydroxide; metal hydroxides such as sodium hydroxide, potassium hydroxide, and calcium hydroxide; metal carbonates such as sodium carbonate, potassium carbonate, and magnesium carbonate; metal bicarbonates such as sodium bicarbonate and potassium bicarbonate, etc.

The amount of the condensation catalyst used is generally in the range of 0.05-10 mol%, preferably 0.1-5 mol%, relative to the total mol amount of the silane compound.

When a solvent is used during the polycondensation, the solvent used can be appropriately selected in combination with the type of silane compound. 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 methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutyl alcohol, 2-butanol, and 3-butanol, etc. These solvents can be used alone or in combination of two or more.

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 molar amount of the silane compound.

The temperature for polycondensing the silane compound is generally 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 is difficult to suppress gelation. The reaction is generally completed in 30 minutes to 30 hours.

When the polysilsesquioxane compound (A) is synthesized by the above method, the part of ^OR4 or ^X1 of the silane compound (1) and ^OR5 or ^X2 of the silane compound (2) that has not been subjected to dealcoholization etc. will remain in the polysilsesquioxane compound (A). Therefore, in addition to the repeating unit represented by the above formula (a-5), the polysilsesquioxane compound (A) also contains the repeating units represented by the above formula (a-3) and formula (a-4).

[Component (C)] The component (C) constituting the curable composition of the present invention is a silane coupling agent. Since the curable composition of the present invention contains the component (C), the cured product of the curable composition of the present invention has better adhesion at room temperature and at high temperature.

The so-called "silane coupling agent" refers to a silane compound having: a silicon atom, a functional group, and a hydrolyzable group bonded to the above silicon atom. The so-called "functional group" refers to a group that is reactive with other compounds (mainly organic substances), such as: an amine group, a substituted amine group, an isocyanate group, a urea group, a group having an isocyanurate skeleton, and other nitrogen atom groups; an anhydride group (having an anhydride structural group); a vinyl group; an allyl group; an epoxy group; a (meth) acrylic group; a hydroxyl group, etc. In the present invention, the silane coupling agent can be used alone or in combination of two or more.

The content of the silane coupling agent is preferably 0.1 to 70 parts by mass, more preferably 1 to 60 parts by mass, particularly preferably 5 to 55 parts by mass, optimally 10 to 50 parts by mass, and most optimally 15 to 45 parts by mass relative to 100 parts by mass of the polysilsesquioxane compound (A). By using a curable composition having a silane coupling agent content within the above range, a cured product having better adhesion at room temperature and at high temperature can be formed.

The silane coupling agent is preferably a silane coupling agent having a nitrogen atom in the molecule or a silane coupling agent having an acid anhydride structure in the molecule, and is more preferably a silane coupling agent having an isocyanurate structure or a silane coupling agent having a succinic anhydride structure in the molecule.

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 following formula (c-2), or a dialkoxyarylsilane compound.

[Chemistry 10]

In the above formula, ^Ra represents an alkoxy group having 1 to 6 carbon atoms, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy, etc. Multiple ^Ra groups may be the same or different from each other. ^Rb represents an alkyl group having 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, etc.; or an aryl group having a substituent or no substituent, such as phenyl, 4-chlorophenyl, 4-methylphenyl, 1-naphthyl, etc.

R ^c represents an organic group having 1 to 10 carbon atoms and having a nitrogen atom. In addition, R ^c may further bond to other silicon-containing groups. Specific examples of organic groups having 1 to 10 carbon atoms of R ^c include N-2-(aminoethyl)-3-aminopropyl, 3-aminopropyl, N-(1,3-dimethyl-butylene)aminopropyl, 3-ureapropyl, N-phenyl-aminopropyl, etc.

In the compound represented by the above formula (c-1) or (c-2), when R ^c is bonded to other silicon-containing organic groups, the compound may be, for example, a silane coupling agent of the isocyanurate type bonded to other silicon atoms via an isocyanurate skeleton, or a silane coupling agent of the urea type bonded to other silicon atoms via a urea skeleton.

Among these, silane coupling agents having nitrogen atoms in the molecule are preferably isocyanurate-based silane coupling agents and urea-based silane coupling agents from the viewpoint of being able to easily obtain a cured product with better adhesion, and more preferably silane coupling agents having 4 or more alkoxy groups bonded to the silicon atom in the molecule. The so-called "4 or more alkoxy groups bonded to the 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.

An example of an isocyanurate-based silane coupling agent having 4 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 4 or more alkoxy groups bonded to a silicon atom is a compound represented by the following formula (c-4).

[Chemistry 11]

In the formula, ^Ra has the same meaning as above. t1-t5 are independent integers of 1-10, preferably 1-6, and more preferably 3.

Among them, the silane coupling agent having a nitrogen atom in the molecule is preferably used, for example: 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 compounds and urea compounds.

When the curable composition of the present invention contains a silane coupling agent having a nitrogen atom in the molecule, the amount contained is not particularly limited. The amount is preferably 100:0.1 to 100:65, more preferably 100:0.3 to 100:60, particularly preferably 100:1 to 100:50, most preferably 100:3 to 100:40, and most preferably 100:5 to 100:35, based on the mass ratio of the above-mentioned 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]. The curable composition containing the component (A) and the silane coupling agent having a nitrogen atom in the molecule in such a ratio will have better heat resistance and adhesion of the cured product.

The silane coupling agent having an acid anhydride structure in the molecule is an organic silicon compound having both an acid anhydride structure group and a hydrolyzable group in one molecule. Specifically, the compound represented by the following formula (c-5) can be cited:

[Chemistry 12]

In the formula, Q represents an anhydride structural group; ^Rd represents an alkyl group with 1 to 6 carbon atoms, or a phenyl group with a substituent (or without a substituent); ^Re represents an alkoxy group with 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, ^Rd can be the same or different from each other. When k is 2 or 3, multiple ^Re can be the same or different from each other. When i is 2 or 3, multiple Q can be the same or different from each other. Q can be exemplified by the following formula:

[Chemistry 13]

(wherein h is an integer from 0 to 10), and more preferably a group represented by (Q1).

Silane coupling agents having an acid anhydride structure in the molecule include, for example, tri(carbon number 1-6) alkoxysilyl(carbon number 2-8) alkyl succinic anhydrides such as 2-(trimethoxysilyl) ethyl succinic anhydride, 2-(triethoxysilyl) ethyl succinic anhydride, 3-(trimethoxysilyl) propyl succinic anhydride, 3-(triethoxysilyl) propyl succinic anhydride, di(carbon number 1-6) alkoxysilyl(carbon number 2-8) alkyl succinic anhydrides such as 2-(dimethoxysilyl) ethyl succinic anhydride, (carbon number 1-6) alkoxydisilyl(carbon number 2-8) alkyl succinic anhydrides such as 2-(methoxydimethylsilyl) ethyl succinic anhydride,

Trihalosilyl (carbon number 2~8) alkyl succinic anhydrides such as 2-(trichlorosilyl)ethyl succinic anhydride and 2-(tribromosilyl)ethyl succinic anhydride; Dihalosilyl (carbon number 2~8) alkyl succinic anhydrides such as 2-(dichlorosilyl)ethyl succinic anhydride; Halogenated disilyl (carbon number 2~8) alkyl succinic anhydrides such as 2-(chlorodimethylsilyl)ethyl succinic anhydride.

Among them, the silane coupling agent having an anhydride structure in the molecule is preferably tri(1-6 carbon atoms)alkoxysilyl(2-8 carbon atoms)alkylsuccinic anhydride, more preferably 3-(trimethoxysilyl)propylsuccinic anhydride or 3-(triethoxysilyl)propylsuccinic anhydride.

When the curable composition of the present invention is a silane coupling agent having an acid anhydride structure in the molecule, the content is not particularly limited. According to the mass ratio of the above-mentioned 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], the amount is preferably 100:0.1~100:30, more preferably 100:0.3~100:20, particularly preferably 100:0.5~100:15, and most preferably 100:1~100:10. The curable composition containing the component (A) and the silane coupling agent having an acid anhydride structure in the molecule according to this ratio will have better adhesion.

[Curing composition] The curable composition of the present invention is the total amount of component (A) and component (C), which preferably accounts for 50-100% by mass, and more preferably 70-100% by mass, of the solid content of the curable composition. In the present invention, the so-called "solid content" refers to the components in the curable composition excluding the solvent.

The curable composition of the present invention may also contain microparticles (hereinafter referred to as "microparticles (B)") having an average primary particle size of 5 nm or more and 40 nm or less of component (B). The curable composition containing microparticles (B) has excellent workability in the coating step. From the perspective of easily obtaining this effect, the average primary particle size of microparticles (B) is preferably 5 to 30 nm, more preferably 5 to 20 nm.

The average primary particle size of the microparticles (B) can be obtained by observing the shape of the microparticles using a transmission electron microscope.

The material of the microparticles (B) may be, for example, 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 silicon dioxide; polysilicon; organic components such as acrylic polymers, etc. Furthermore, the surface of the microparticles (B) used may also be modified.

The microparticles (B) may be used alone or in combination of two or more. When the curable composition of the present invention contains microparticles (B) [(B) component], the content of the (B) component is not particularly limited. According to the mass ratio of the (A) component to the (B) component [(A) component: (B) component], the content is preferably 100:0.1~100:90, more preferably 100:0.2~100:60, particularly preferably 100:0.3~100:50, optimally 100:0.5~100:40, and most optimally 100:0.8~100:30. By using the (B) component within the above range, the effect of the weighted (B) component can be more pronounced.

The curable composition of the present invention may also contain other ingredients within the scope that does not harm the purpose of the present invention. Such other ingredients may include, for example, antioxidants, ultraviolet absorbers, light stabilizers, etc.

Antioxidants are added to prevent oxidation degradation during heating. Examples of antioxidants include phosphorus-based antioxidants, phenol-based antioxidants, and sulfur-based antioxidants.

Examples of phosphorus-based antioxidants include phosphites, oxophosphine phenanthroline oxides, etc. Examples of phenol-based antioxidants include monophenols, bisphenols, and polymer phenols, etc. Examples of sulfur-based antioxidants include dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, and distearyl 3,3'-thiodipropionate, etc.

The antioxidants may be used alone or in combination of two or more. The amount of the antioxidant contained is not particularly limited, but is usually 10% by mass or less relative to the component (A).

The UV absorber is added for the purpose of improving the light resistance of the obtained cured product. Examples of UV absorbers include salicylic acid, diphenyl ketone, benzotriazole, hindered amine, etc. UV absorbers can be used alone or in combination of two or more. The content of the UV absorber is not particularly limited, but is usually less than 10% by mass relative to component (A).

Light stabilizers are added for the purpose of improving the light resistance of the obtained cured product. 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-piperidinyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidinyl)imino}], etc. Such light stabilizers can be used alone or in combination of two or more. The content of light stabilizers is usually less than 20% by mass relative to component (A).

The curable composition of the present invention may also contain a diluent. The diluent is not particularly limited as long as it can dissolve (or disperse) the components of the curable composition of the present invention. The diluent may be used alone or in combination of two or more.

When the curable composition of the present invention contains a diluent, the content is preferably 60% by mass or more and less than 100% by mass, more preferably 65 to 98% by mass, and particularly preferably 70 to 95% by mass. The polysilsesquioxane compound (A) used in the present invention is mostly of a small molecular weight. The curable composition containing such a polysilsesquioxane compound (A) has good coating properties even if it does not contain a large amount of diluent (i.e., even if the solid content concentration is high). When a curable composition with a high solid content concentration is used, even if the drying conditions and curing conditions of the coating are not strictly controlled, because the cured product contains almost no solvent, a cured product with certain characteristics can be stably formed.

The curable composition of the present invention has a high refractive index because it contains a polysilsesquioxane compound (A). The refractive index (nD) of the curable composition of the present invention at 25°C is usually 1.46 or more, preferably 1.46 to 1.56, particularly preferably 1.46 to 1.54, and most preferably 1.47 to 1.53. The refractive index (nD) of the curable composition can be measured using the method described in the embodiments.

The curable composition of the present invention is prepared by mixing the above-mentioned component (A) and component (C), and other components as needed, in a predetermined ratio and defoaming. The mixing method and defoaming method are not particularly limited, and known methods can be used.

2) Cured product The cured product of the present invention is obtained by curing the curable composition of the present invention. The method for curing the curable composition of the present invention is, for example, heat curing. The heating temperature during curing is usually 100-200°C, and the heating time is usually 10 minutes to 20 hours, preferably 30 minutes to 10 hours.

The hardened material of the present invention has excellent heat resistance and adhesion. The fact that the hardened material of the present invention has these characteristics can be confirmed, for example, as follows. That is, a predetermined amount of the hardening composition of the present invention is applied on the mirror surface of a silicon wafer, and the coated surface is placed on an adherend, pressed, and heat-treated to harden. It is placed on a measuring platform of a welding tester that has been preheated to a predetermined temperature (e.g., 23°C, 100°C) for 30 seconds, and a stress is applied to the adhesive surface in the horizontal direction (shear direction) from a height of 50μm from the adherend, and the adhesion between the test piece and the adherend is measured.

The adhesive force of the cured product of the present invention is preferably 100N/ ^4mm2 or more at 23°C, more preferably 120N/ ^4mm2 or more. The adhesive force of the cured product of the present invention is preferably 40N/ ^4mm2 or more at 100°C, more preferably 45N/ ^4mm2 or more. In this specification, " ^4mm2 " means "2mm square", i.e., 2mm×2mm (a square with a side length of 2mm).

The hardened material of the present invention has a high refractive index and excellent adhesion. Therefore, the hardened material of the present invention is preferably used as an adhesive layer with a high refractive index. The 25°C refractive index (nD) of the hardened material of the present invention is usually above 1.46, preferably 1.46~1.56, more preferably 1.46~1.54, and particularly preferably 1.47~1.53. The refractive index (nD) of the hardened material can be measured using an Abbe refractometer.

Due to the above characteristics, the hardened material of the present invention is preferably used as an optical element fixing material.

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 optical element fixing material or a sealing material for optical element fixing material. The optical element may be, for example, a light-emitting element such as LED, LD, a light-receiving element, a composite optical element, an optical integrated circuit, etc.

<Adhesive for optical element fixing material> The curable composition of the present invention is preferably used as an adhesive for optical element fixing material. The method of using the curable composition of the present invention as an adhesive for optical element fixing material is, for example, to apply the composition on the adhesive surface of one (or both) of the bonding materials (optical element and its substrate, etc.), and after pressing, heat curing is performed to make the bonding materials firmly adhere to each other. There is no particular limitation on the amount of the curable composition applied, as long as the amount is used to make the bonding materials firmly adhere to each other. Usually, the coating thickness of the curable composition is 0.5~5μm, preferably 1~3μm.

The substrate material for bonding optical components can be exemplified by: glass such as sodium calcium glass and heat-resistant hard glass; ceramics; sapphire; iron, copper, aluminum, gold, silver, platinum, chromium, titanium and their metal alloys; metals such as stainless steel (SUS302, SUS304, SUS304L, SUS309, etc.); polyethylene terephthalate; Ester, polybutylene terephthalate, polyethylene naphthalate, ethylene-vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyetheretherketone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyimide, polyamide, acrylic resin, norbornene resin, cycloolefin resin, glass epoxy resin and other synthetic resins, etc.

The heating temperature during heat curing depends on the curable composition used, etc., and is usually 100-200°C. The heating time is usually 10 minutes to 20 hours, preferably 30 minutes to 10 hours.

<Sealing material for optical element fixing material> The curable composition of the present invention is suitable for use as a sealing material for optical element fixing material. The method of using the curable composition of the present invention as a sealing material for optical element fixing material is, for example, a method of forming the composition into a desired shape to obtain a molded body containing an optical element, and then heat-curing it to produce an optical element sealed body. The method of forming the curable composition of the present invention into a desired shape is not particularly limited, and a conventional transfer molding method, injection molding method, or other known molding method can be used.

The heating temperature during heat curing depends on the curable composition used, etc., and is usually 100-200°C. The heating time is usually 10 minutes to 20 hours, preferably 30 minutes to 10 hours.

The obtained optical component sealed body has excellent heat resistance and adhesion because it uses the curable composition of the present invention. [Example]

The present invention is described in more detail below with reference to the following embodiments. However, the present invention is not limited to the following embodiments.

(Average molecular weight measurement) The mass average molecular weight (Mw) and number average molecular weight (Mn) of polysilsesquioxane compounds are standard polystyrene conversion values and are measured according to the following equipment and conditions. Apparatus name: HLC-8220GPC, manufactured by Tosoh Corporation Column: TSKgelGMHXL, TSKgelGMHXL, and TSKge12000HXL connected in sequence Solvent: Tetrahydrofuran Injection volume: 20μl Measurement temperature: 40℃ Flow rate: 0.6ml/min Detector: Differential refractometer

( ²⁹ Si-NMR measurement) In order to investigate the repeating unit and amount of polysilsesquioxane compounds, ²⁹ Si-NMR measurement was performed under the following conditions. Apparatus: AV-500 manufactured by Bruker BioSpin ²⁹ Si-NMR resonance frequency: 99.352MHz Probe: 5mmϕ solution probe Measurement temperature: room temperature (25°C) Sample rotation speed: 20kHz Measurement method: reverse gated decoupling method ²⁹ Si deflection angle: 90° ²⁹ Si 90° Pulse width: 8.0μs Repeat time: 5s Number of integrations: 9200 times Observation width: 30kHz

( ²⁹ Si-NMR sample preparation method) In order to shorten the relaxation time, Fe(acac) ₃ , a relaxation reagent, was added for measurement. Polysilsesquioxane compound concentration: 15 mass % Fe(acac) ₃ concentration: 0.6 mass % Measurement solvent: Acetone Internal standard: TMS

(Waveform processing analysis) For each peak of the mass spectrum after Fourier transformation, the chemical shift is obtained from the peak top position, and each peak is integrated according to the following range. The ratio of the T1 site, T2 site, and T3 site is calculated from the obtained value. T site with phenyl group (T1: -65~-58ppm, T2: -74~-65ppm, T3: -82~-75ppm) T site with methyl group (T1: -50~-46ppm, T2: -61~-52ppm, T3: -70~-61ppm)

(Refractive index) The refractive index (nD) of the polysilsesquioxane compound was measured at 25°C using a multi-wavelength Abbe refractometer (DR-M2, manufactured by ATAGO Co., Ltd.).

(Production Example 1) After placing 9.34 g (47.1 mmol) of phenyltrimethoxysilane and 8.40 g (47.1 mmol) of methyltriethoxysilane in a 300 ml eggplant-shaped flask, an aqueous solution of 0.025 g of 35 mass% hydrochloric acid (0.25 mol% of HCl relative to the total amount of silane compounds) dissolved in 5.09 g of distilled water was added while stirring, and the whole was stirred at 30°C for 2 hours, and then the temperature was raised to 80°C and stirred for 20 hours. After the reaction solution was left to cool to room temperature, 50 g of propyl acetate and 100 g of water were added thereto, and a separation treatment was performed to obtain an organic layer containing the reaction product. Magnesium sulfate was added to the organic layer for drying. After removing magnesium sulfate by filtration, the organic layer is concentrated using an evaporator, and then the obtained concentrate is vacuum dried to obtain a polysilsesquioxane compound (A1).

(Production Example 2) In a 300 ml eggplant-shaped flask, 12.55 g (63.3 mmol) of phenyltrimethoxysilane and 4.83 g (27.1 mmol) of methyltriethoxysilane were placed, and an aqueous solution of 0.024 g of 35% by mass hydrochloric acid (0.25 mol% of HCl relative to the total amount of silane compounds) dissolved in 4.88 g of distilled water was added while stirring, and the whole was stirred at 30°C for 2 hours, and then the temperature was raised to 80°C and stirred for 20 hours. While continuing to stir the contents, 17 g of propyl acetate and 0.149 g of 28% by mass ammonia water (2.5 mol% relative to phenyltriethoxysilane) were added thereto, and the temperature was raised to 80°C and stirred for 20 hours. After the reaction solution was left to cool to room temperature, liquid separation, drying treatment, etc. were performed in the same manner as in Production Example 1 to obtain a polysilsesquioxane compound (A2).

(Production Example 3) After placing 9.34 g (47.1 mmol) of phenyltrimethoxysilane and 8.40 g (47.1 mmol) of methyltriethoxysilane in a 300 ml eggplant-shaped flask, an aqueous solution of 0.294 g (3.00 mol% of HCl relative to the total amount of silane compounds) of 35% by mass of hydrochloric acid dissolved in 5.09 g of distilled water was added while stirring, and the whole was stirred at 30°C for 2 hours, and then the temperature was raised to 80°C and stirred for 20 hours. After the reaction solution was left to cool to room temperature, 50 g of propyl acetate and 100 g of water were added thereto, and a separation treatment was performed to obtain an organic layer containing the reaction product. Magnesium sulfate was added to the organic layer for drying. After removing magnesium sulfate by filtration, the organic layer is concentrated by an evaporator, and then the concentrate is vacuum dried to obtain a polysilsesquioxane compound (A3).

(Comparative Production Example 1) After placing 14.455 g (72.9 mmol) of phenyltrimethoxysilane in a 300 ml eggplant-shaped flask, an aqueous solution of 0.0188 g of 35 mass% hydrochloric acid (0.25 mol% of HCl relative to phenyltrimethoxysilane) dissolved in 3.937 g of distilled water was added while stirring, and the whole was stirred at 30°C for 2 hours, and then the temperature was raised to 70°C and stirred for 22 hours. While continuing to stir the contents, 15 g of propyl acetate and 0.0109 g of 28 mass% ammonia water (0.25 mol% relative to phenyltriethoxysilane) were added thereto, and the temperature was raised to 80°C and stirred for 20 hours. After the reaction solution was left to cool to room temperature, liquid separation, drying treatment, etc. were performed in the same manner as in Production Example 1 to obtain a polysilsesquioxane compound (A4).

(Comparative Preparation Example 2) After placing 28.77 g (145.1 mmol) of phenyltrimethoxysilane and 0.2675 g (1.5 mmol) of methyltriethoxysilane in a 300 ml eggplant-shaped flask, an aqueous solution of 0.477 g (3 mol% of HCl relative to the total amount of the silane compound) of 35% by mass of hydrochloric acid dissolved in 8.24 g of distilled water was added while stirring, and the whole was stirred at 30°C for 2 hours, and then the temperature was raised to 80°C and stirred for 20 hours. After the reaction solution was left to cool to room temperature, liquid separation and drying treatment were performed in the same manner as in Preparation Example 1 to obtain a polysilsesquioxane compound (A5).

The detailed contents of the obtained polysilsesquioxane compound (PSQ) are shown in Table 1.

[Table 1] Table 1 Repeating unit (1) (mol%) Repeating unit (2) (mol%) Mass average molecular weight (Mw) Molecular weight distribution (Mw/Mn) Refractive index (nD) Ratio of T site (mol%) T1 T2 T3 Manufacturing Example 1 PSQ(A1) 50 50 2800 1.9 1.513 0 31 69 Manufacturing Example 2 PSQ(A2) 70 30 2400 1.5 1.539 0 28 72 Manufacturing Example 3 PSQ(A3) 50 50 16900 6.3 1.513 0 twenty two 78 Comparative Manufacturing Example 1 PSQ(A4) 100 0 1700 1.3 1.566 4 27 69 Comparative Manufacturing Example 2 PSQ(A5) 99 1 1700 1.3 1.563 0 36 64

The compounds used in the Examples, Comparative Examples and Reference Examples are as follows:

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

(Filling agent) Silica particles: (manufactured by Nippon Silica Co., Ltd., product name "AEROSIL RX300", average primary particle size: 7nm, specific surface area: ^210m2 /g)

(Example 1) In 100 parts by mass of polysilsesquioxane compound (A1), 5 parts by mass of silica microparticles are added, and a mixed solvent of diethylene glycol monobutyl ether acetate: tripropylene glycol n-butyl ether = 40:60 (mass ratio) is further added, and the whole is stirred. After dispersion treatment using a three-roll mill, 30 parts by mass of silane coupling agent (C1) and 3 parts by mass of silane coupling agent (C2) are added, and the whole is fully mixed and defoamed to obtain a curable composition with a solid content concentration of 80% by mass.

(Example 2) In Example 1, except that the polysilsesquioxane compound (A1) was replaced with the polysilsesquioxane compound (A2), the content of the silicon dioxide particles was changed to 20 parts by mass, and the amount of the mixed solvent was changed, the rest was the same as in Example 1 to obtain a curable composition with a solid content concentration of 80% by mass.

(Example 3) Except that in Example 1, the polysilsesquioxane compound (A1) is replaced with the polysilsesquioxane compound (A3), the rest is the same as in Example 1 to obtain a curable composition with a solid content concentration of 80 mass %.

(Comparative Example 1) In Example 1, except that the polysilsesquioxane compound (A1) was replaced with the polysilsesquioxane compound (A4), the content of the silicon dioxide particles was changed to 20 parts by mass, and the amount of the mixed solvent was changed, the rest was the same as in Example 1 to obtain a curable composition with a solid content concentration of 80% by mass.

(Comparative Example 2) In Example 1, except that the polysilsesquioxane compound (A1) was replaced with the polysilsesquioxane compound (A5), the silane coupling agent (C1) and the silane coupling agent (C2) were not used, and the amount of the mixed solvent was changed, the rest was the same as in Example 1 to obtain a curable composition with a solid content concentration of 78 mass %.

(Comparative Example 3) In Example 1, except that silane coupling agent (C1) and silane coupling agent (C2) were not used and the amount of mixed solvent was changed, the rest was the same as Example 1 to obtain a curable composition with a solid content concentration of 75 mass%.

The following measurements and tests were performed using the curable compositions obtained in the Examples, Comparative Examples, and Reference Examples. [Refractive index measurement] The refractive index (nD) of the curable composition was measured at 25°C using a multi-wavelength Abbe refractometer (manufactured by ATAGO Co., Ltd., DR-M2).

[Evaluation of crack resistance] The curable compositions obtained in the examples and comparative examples were coated on the mirror surface of a square glass wafer with a side length of 0.5 mm to a thickness of about 2 μm, and the coated surface was placed on an adherend (silver-plated copper plate) and pressed. Then, the adherend was cured by heating at 170°C for 2 hours to obtain a test piece. In addition, 20 test pieces were prepared for each curable composition. The resin portion (fillet portion) exuded from the glass wafer was observed using a scanning electron microscope (KEYENCE VE-9800S), and the number of samples with cracks was counted. Samples with a crack occurrence rate of 0% or more and less than 25% were rated "A", those with a crack occurrence rate of 25% or more and less than 50% were rated "B", and those with a crack occurrence rate of 50% or more and less than 100% were rated "C".

[Evaluation of Adhesion Strength] The curable compositions obtained in the Example and the Comparative Example were coated on the mirror surface of a 2mm square ( ^4mm2 area) silicon wafer to a thickness of about 2μm, and the coated surface was placed on an adherend (silver-plated copper plate) and pressed. Then, the adhesive was cured by heating at 170℃ for 2 hours to obtain an adherend with a test piece. The adherend with the test piece was placed on the measuring platform of a welding tester (Dage, Series 4000) preheated to a predetermined temperature (23°C, 100°C) for 30 seconds. A stress was applied to the adhesive surface in the horizontal direction (shear direction) at a speed of 200 μm/s from a height of 50 μm from the adherend. The adhesion (N/4mm ² ) between the test piece at 23°C and 100°C and the adherend was measured.

The measurement results and evaluation results are shown in Table 2.

[Table 2] Table 2 Composition of the curable composition (by weight) Solid content concentration (mass %) Refractive index (nD) Turtle crack resistance evaluation Adhesion strength (N/4mm ² ) PSQ Silane coupling agent Silicon dioxide particles (C1) (C2) 23℃ 100℃ Embodiment 1 PSQ(A1) 100 30 3 5 80 1.488 A 129.7 51.4 Embodiment 2 PSQ(A2) 100 30 3 20 80 1.495 A 149.1 83.4 Embodiment 3 PSQ(A3) 100 30 3 5 80 1.488 A 166.8 67.7 Comparison Example 1 PSQ(A4) 100 30 3 20 80 1.507 C 116.0 59.3 Comparison Example 2 PSQ(A5) 100 0 0 5 78 1.532 A 26.8 9.5 Comparison Example 3 PSQ(A1) 100 0 0 5 75 1.494 A 62.4 37.5

The following is known from the above-mentioned Examples, Comparative Examples and Reference Examples. The curable compositions of Examples 1 to 3 have a polysilsesquioxane compound (PSQ(A1), PSQ(A2), PSQ(A3)) containing a repeating unit (1), and thus the refractive index is appropriately improved. Furthermore, the curable compositions of Examples 1 to 3 contain a silane coupling agent. Moreover, any one of PSQ(A1), PSQ(A2) and PSQ(A3) contains a repeating unit (2) and appropriately contains a T2 site. Therefore, the cured materials of Examples 1 to 3 are excellent in both crack resistance and adhesion. On the other hand, the curable composition of Comparative Example 1 also contains a polysilsesquioxane compound (PSQ(A4)) containing a high proportion of the repeating unit (1), and thus the refractive index is high. However, PSQ (A4) does not have a repeating unit (2) and the ratio of the T2 site is not high, so the hardened material of the hardening composition of Comparative Example 1 has poor crack resistance. On the other hand, the hardening compositions obtained in Comparative Examples 2 and 3 do not contain a silane coupling agent, so the hardened materials do not have sufficient adhesion strength.

without.

without.

Claims (12)

A curable composition comprises the following components (A) and (C): Component (A): having a repeating unit [repeating unit (1)] represented by the following formula (a-1): [Chemical 1] R ¹ SiO _3/2 (a-1), wherein R ¹ represents an unsubstituted aryl group having 6 to 12 carbon atoms or a substituted aryl group having 6 to 12 carbon atoms; and having a repeating unit [repeating unit (2)] represented by the following formula (a-2), wherein the total amount of the repeating unit (1) and the repeating unit (2) in the component (A) accounts for 90 to 100 mol% of the total repeating units in the component (A); [Chemical 2] R ² SiO _3/2 (a-2), wherein R ² is a polysilsesquioxane compound which represents an unsubstituted alkyl group having 1 to 10 carbon atoms or a substituted alkyl group having 1 to 10 carbon atoms, and satisfies the following requirements 1 and 2: [Requirement 1] the amount of the repeating unit (1) is 40 mol% or more and less than 80 mol% relative to the total amount of the repeating unit (1) and the repeating unit (2); [Requirement 2] the amount of the T2 site is 20 to 70 mol% relative to the total amount of the T site (T1 site) represented by the following formula (a-3), the T site (T2 site) represented by the following formula (a-4), and the T site (T3 site) represented by the following formula (a-5); [Requirement 3]

Wherein, G represents a group represented by ^R1 or ^R2 , ^R3 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, * is bonded to a silicon atom, and (C) component: a silane coupling agent. The curable composition as described in claim 1, wherein the mass average molecular weight (Mw) of component (A) is 500~25,000. The curable composition as described in claim 1, wherein the silane coupling agent of component (C) is a silane coupling agent having an acid anhydride structure in the molecule. The curable composition as described in claim 1, wherein the content of component (C) is 0.1 to 70 parts by mass relative to 100 parts by mass of component (A). The curable composition as described in claim 1, wherein the total amount of component (A) and component (C) accounts for 50-100% by mass of the solid content of the curable composition. The curable composition as described in claim 1 further contains the following (B) component, the mass ratio of (A) component to (B) component [(A) component: (B) component] is 100:0.1~100:90, (B) component: microparticles of silicon dioxide with an average primary particle size of 5nm or more and 40nm or less. The curable composition as described in claim 1, further comprising a diluent, wherein the solid content concentration is greater than 60% by mass and less than 100% by mass. The curable composition as described in any one of claims 1 to 7, wherein the refractive index (nD) at 25°C is 1.46~1.56. A hardened material obtained by hardening the hardening composition described in any one of claims 1 to 8. The hardened material in claim 9 is a fixing material for optical components. A method for using a curable composition is to use the curable composition described in any one of claim 1 to claim 8 as an adhesive for fixing an optical component. A method for using a curable composition is to use the curable composition described in any one of claim 1 to 8 as a sealing material for fixing an optical component.