阅读说明：本技术 固化性聚倍半硅氧烷化合物、固化性组合物、固化物和固化性组合物的使用方法 (Curable polysilsesquioxane compound, curable composition, cured product, and method for using curable composition ) 是由 梅田明来子 宫胁学 中山秀一 于 2019-09-27 设计创作，主要内容包括：本发明提供：固化性聚倍半硅氧烷化合物,其是具有下述式(a-1)所示的重复单元的固化性聚倍半硅氧烷化合物,其特征在于,满足与～(29)Si-NMR相关的特定要件,质均分子量(Mw)为特定的范围；含有该固化性聚倍半硅氧烷化合物的固化性组合物；将该固化性组合物固化而成的固化物；以及将上述固化性组合物用作光元件固定材料用粘接剂或光元件固定材料用密封材料的方法。本发明的固化性组合物是固化性优异、并且折射率低的组合物。式(a-1)中,R～1表示以组成式：C-mH-((2m-n+1))F-n表示的氟烷基。m表示1～10的整数,n表示2以上且(2m+1)以下的整数。D表示连接R～1和Si的连接基(其中,亚烷基除外)或单键。(The present invention provides: a curable polysilsesquioxane compound having a repeating unit represented by the following formula (a-1), characterized by satisfying the following relation 29 A specific requirement relating to Si-NMR, wherein the mass average molecular weight (Mw) is in a specific range; a curable composition containing the curable polysilsesquioxane compound; a cured product obtained by curing the curable composition; and a method for using the curable composition as an adhesive for optical element-fixing materials or a sealing material for optical element-fixing materials. The curable composition of the present invention has excellent curability and a low refractive index. In the formula (a-1), R 1 Expressed by the compositional formula: c m H (2m‑n+1) F n A fluoroalkyl group represented by the formula (I). m represents an integer of 1 to 10, and n represents an integer of 2 or more and (2m +1) or less. D represents the bond R 1 And a linking group of Si (wherein, alkylene is excluded) or a single bond.)

1. A curable polysilsesquioxane compound which is a curable polysilsesquioxane compound having a repeating unit represented by the following formula (a-1), characterized in that: the following requirements 1 and 2 are satisfied,

[ chemical formula 1]

R¹Expressed by the compositional formula: c_mH_(2m-n+1)F_nWherein m represents an integer of 1 to 10, n represents an integer of 2 to (2m +1), and D represents a connecting R¹And Si, with the exception of alkylene groups in said linking group,

[ element 1]

In the determination of curable polysilsesquioxane compounds²⁹Si-NMR in a region of-62 ppm or more and less than-52 ppm [ region (2) ]]1 or 2 or more peaks were observed in a region of-52 ppm or more and less than-45 ppm [ region (1) ]]And a region of-73 ppm or more and less than-62 ppm [ region (3)]At least one region in the above (1) or (2) or more peaks are observed, and Z2 derived from the following formula is 20 to 40%,

[ mathematical formula 1]

P1: an integrated value in the region (1);

p2: an integrated value in the region (2);

p3: the value of the integral in the region (3),

[ element 2]

The curable polysilsesquioxane compound has a mass average molecular weight (Mw) of 4,000 to 11,000.

2. The curable polysilsesquioxane compound according to claim 1, wherein the proportion of the repeating unit represented by formula (a-1) to all repeating units is 25mol% or more.

3. The curable polysilsesquioxane compound according to claim 1 or 2, further comprising a repeating unit represented by the following formula (a-2),

[ chemical formula 2]

R²Represents an unsubstituted alkyl group having 1 to 10 carbon atoms or an unsubstituted aryl group having 6 to 12 carbon atoms.

4. The curable polysilsesquioxane compound according to claim 3, wherein the proportion of the repeating unit represented by formula (a-2) relative to all repeating units is more than 0mol% and 75mol% or less.

5. The curable polysilsesquioxane compound according to any one of claims 1 to 4, wherein the measurement is performed²⁹In Si-NMR, 1 or 2 or more peaks are observed in the region (3), and Z3 derived from the following formula is 60 to 80%,

[ mathematical formula 2]

。

6. A curable composition characterized by: contains the following component (A) and a solvent having a boiling point of 254 ℃ or higher,

(A) the components: the curable polysilsesquioxane compound according to any one of claims 1 to 5.

7. The curable composition according to claim 6, further comprising a component (B),

(B) the components: a silane coupling agent having a nitrogen atom in the molecule.

8. The curable composition according to claim 6 or 7, further comprising a component (C),

(C) the components: a silane coupling agent having an acid anhydride structure in the molecule.

9. The curable composition according to any one of claims 6 to 8, further comprising a component (D),

(D) the components: fine particles having an average primary particle diameter of 5 to 40 nm.

10. A cured product obtained by curing the curable composition according to any one of claims 6 to 9.

11. The cured product according to claim 10, which is an optical device-fixing material.

12. A method for using the curable composition according to any one of claims 6 to 9 as an adhesive for optical device-fixing materials.

13. A method for using the curable composition according to any one of claims 6 to 9 as a sealing material for an optical device-fixing material.

Technical Field

The present invention relates to: a curable polysilsesquioxane compound; a curable composition containing the curable polysilsesquioxane compound, having excellent curability and a low refractive index; a cured product having high adhesive strength, which is obtained by curing the curable composition; and a method for using the curable composition as an adhesive for optical element-fixing materials or a sealing material for optical element-fixing materials.

Background

Conventionally, curable compositions have been improved variously depending on the application, and are widely used industrially as a raw material, an adhesive, a coating agent, and the like for optical components or molded articles.

The curable composition has also attracted attention as a composition for an optical element fixing material, such as an adhesive for an optical element fixing material or a sealing material for an optical element fixing material.

Examples of the optical device include various lasers such as a semiconductor Laser (LD), a light emitting device such as a Light Emitting Diode (LED), a light receiving device, a composite optical device, and an optical integrated circuit.

In recent years, optical devices that emit blue light or white light having a short peak wavelength have been developed and widely used. The brightness of the light-emitting element having a short peak wavelength of light emission has been dramatically increased, and the amount of heat generated by the light-emitting element tends to further increase.

However, with the recent increase in luminance of optical devices, there has been a problem that the adhesive strength is reduced when a cured product of the composition for an optical device-fixing material is exposed to light of higher energy or heat of higher temperature generated by the optical device for a long time.

In order to solve this problem, patent documents 1 to 3 propose: a composition for optical element fixing material containing polysilsesquioxane compound as main component.

However, even cured products of the compositions described in patent documents 1 to 3 may have difficulty in obtaining heat resistance while maintaining sufficient adhesion.

In addition, when an optical element or the like is fixed using a curable composition, it is often important to form a cured product having a refractive index that matches a target refractive index. In particular, since many conventional curable compositions and cured products thereof have a high refractive index, a curable composition having a lower refractive index is required.

Patent document 4 describes a curable composition containing a fluoroalkyl-containing curable polysilsesquioxane compound as a curable composition that provides a cured product having a low refractive index.

However, as shown in the examples of patent document 4, when a curable composition containing a curable polysilsesquioxane compound having a high proportion of repeating units having fluoroalkyl groups is used, it is difficult to obtain a cured product having high adhesive strength. As described above, the cured product of the curable composition described in patent document 4 has a trade-off relationship between high adhesive strength and low refractive index. Therefore, when the curable composition described in patent document 4 is used, it is difficult to obtain a cured product having both high adhesive strength and low refractive index.

It is also known that workability and the like are improved by adding a filler or the like to the curable composition.

However, since a curable composition containing a filler or the like or a cured product thereof tends to have a high refractive index, a curable composition having a low refractive index even when a filler or the like is added is desired.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2004-359933;

patent document 2: japanese patent laid-open publication No. 2005-263869;

patent document 3: japanese patent laid-open publication No. 2006-328231;

patent document 4: WO2017/110948 (US 2018/0355111A 1).

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above-described actual situation of the conventional art, and an object thereof is to provide: a curable composition having excellent curability and a low refractive index; a curable polysilsesquioxane compound that can be used as a component of the curable composition; a cured product having high adhesive strength, which is obtained by curing the curable composition; and a method for using the curable composition as an adhesive for optical element-fixing materials or a sealing material for optical element-fixing materials.

In the present invention, the "curable composition" refers to a composition which changes into a cured product by satisfying a predetermined condition such as heating.

In the present invention, the "curable polysilsesquioxane compound" refers to a polysilsesquioxane compound that changes to a cured product by itself when predetermined conditions such as heating are satisfied, or a polysilsesquioxane compound that functions as a curable component in the curable composition.

Means for solving the problems

In order to solve the above problems, the present inventors have conducted intensive studies on a curable polysilsesquioxane compound having a fluoroalkyl group.

As a result, the following were found:

(1) the problem of the decrease in the adhesive strength of a cured product caused by introducing (introducing) a fluoroalkyl group into a curable polysilsesquioxane compound is solved by using a curable polysilsesquioxane compound (hereinafter, sometimes referred to as "curable polysilsesquioxane compound (a)") having a specific repeating unit and satisfying both a requirement relating to a molecular structure (later-described requirement 1) and a requirement relating to a molecular weight (later-described requirement 2); and

(2) the curable composition containing the curable polysilsesquioxane compound (a) has excellent curability, and therefore has an advantage that a curing reaction can be carried out without excessively heating the composition.

Further found that: the curable composition containing the curable polysilsesquioxane compound (a) and the solvent having a boiling point of 254 ℃ or higher has the same operability as immediately after coating because the viscosity change is small even when the composition is left for a long time after coating.

The present invention has been completed based on these findings.

Thus, the present invention provides the following curable polysilsesquioxane compounds of [1] to [5], the curable compositions of [6] to [9], the cured products of [10] and [11], and the methods of using the curable compositions of [12] and [13 ].

[1] A curable polysilsesquioxane compound which is a curable polysilsesquioxane compound having a repeating unit represented by the following formula (a-1), characterized in that: the following requirements 1 and 2 are satisfied,

[ chemical formula 1]

R¹Expressed by the compositional formula: c_mH_(2m-n+1)F_nWherein m represents an integer of 1 to 10, n represents an integer of 2 to (2m +1), and D represents a connecting R¹And Si (a linking group) (wherein alkylene is excluded) or a single bond,

[ element 1]

In the determination of curable polysilsesquioxane compounds²⁹Si-NMR in a region of-62 ppm or more and less than-52 ppm [ region (2) ]]1 or 2 or more peaks were observed in a region of-52 ppm or more and less than-45 ppm [ region (1) ]]And a region of-73 ppm or more and less than-62 ppm [ region (3)]At least one region in the above (1) or (2) or more peaks are observed, and Z2 derived from the following formula is 20 to 40%,

[ mathematical formula 1]

P1: an integrated value in the region (1);

p2: an integrated value in the region (2);

p3: the value of the integral in the region (3),

[ element 2]

The curable polysilsesquioxane compound has a mass average molecular weight (Mw) of 4,000 to 11,000.

[2] [1] the curable polysilsesquioxane compound according to the present invention, wherein the proportion of the repeating unit represented by the formula (a-1) is 25mol% or more based on the total repeating units.

[3] [1] the curable polysilsesquioxane compound according to [1] or [2], which further comprises a repeating unit represented by the following formula (a-2),

[ chemical formula 2]

R²Represents an unsubstituted alkyl group having 1 to 10 carbon atoms or an unsubstituted aryl group having 6 to 12 carbon atoms.

[4] [3] the curable polysilsesquioxane compound according to the present invention, wherein the proportion of the repeating unit represented by the formula (a-2) relative to all the repeating units is more than 0mol% and 75mol% or less.

[5] [1]～[4]The curable polysilsesquioxane compound of any one of the above, wherein, in the measurement²⁹In Si-NMR, 1 or 2 or more peaks are observed in the region (3), and Z3 derived from the following formula is 60 to 80%,

[ mathematical formula 2]

。

[6] A curable composition characterized by: contains the following component (A) and a solvent having a boiling point of 254 ℃ or higher,

(A) the components: [1] the curable polysilsesquioxane compound according to any one of [1] to [5 ].

[7] [6] the curable composition further comprising the following component (B),

(B) the components: a silane coupling agent having a nitrogen atom in the molecule.

[8] The curable composition according to [6] or [7], which further comprises the following component (C),

(C) the components: a silane coupling agent having an acid anhydride structure in the molecule.

[9] The curable composition according to any one of [6] to [8], further comprising the following component (D),

(D) the components: fine particles having an average primary particle diameter of 5 to 40 nm.

[10] A cured product obtained by curing the curable composition according to any one of [6] to [9 ].

[11] [10] the cured product of the optical element-fixing material.

[12] A method for using the curable composition according to any one of the above [6] to [9] as an adhesive for an optical element-fixing material.

[13] A method for using the curable composition according to any one of the above [6] to [9] as an encapsulating material for an optical device-fixing material.

Effects of the invention

According to the present invention, there is provided: a curable composition having excellent curability and a low refractive index; a curable polysilsesquioxane compound that can be used as a component of the curable composition; a cured product having high adhesive strength, which is obtained by curing the curable composition; and a method for using the curable composition as an adhesive for optical element-fixing materials or a sealing material for optical element-fixing materials.

Detailed Description

The invention is divided into the following: 1) the curable polysilsesquioxane compound, 2) the curable composition, 3) the cured product, and 4) the method for using the curable composition will be described in detail.

1) Curable polysilsesquioxane compound

The curable polysilsesquioxane compound [ curable polysilsesquioxane compound (a) ] of the present invention is characterized in that: the curable polysilsesquioxane compound having a repeating unit represented by the following formula (a-1) satisfies the requirements 1 and 2.

[ chemical formula 3]

R¹Expressed by the compositional formula: c_mH_(2m-n+1)F_nA fluoroalkyl group represented by the formula (I). m represents an integer of 1 to 10, and n represents an integer of 2 or more and (2m +1) or less. D represents the bond R¹And a linking group of Si (wherein, alkylene is excluded) or a single bond.

In the formula (a-1), R¹Expressed by the compositional formula: c_mH_(2m-n+1)F_nA fluoroalkyl group represented by the formula (I). m represents an integer of 1 to 10, and n represents an integer of 2 or more and (2m +1) or less. m is preferably an integer of 1 to 5, more preferably an integer of 1 to 3.

By using a compound having R¹The curable polysilsesquioxane compound of (2) can give a curable composition having a low refractive index.

As a constituent formula: c_mH_(2m-n+1)F_nThe fluoroalkyl group represented by (a) may be, for example: CF (compact flash)₃、CF₃CF₂、CF₃(CF₂)₂、CF₃(CF₂)₃、CF₃(CF₂)₄、CF₃(CF₂)₅、CF₃(CF₂)₆、CF₃(CF₂)₇、CF₃(CF₂)₈、CF₃(CF₂)₉Etc. perfluoroalkyl groups; CF (compact flash)₃CH₂CH₂、CF₃(CF₂)₃CH₂CH₂、CF₃(CF₂)₅CH₂CH₂、CF₃(CF₂)₇CH₂CH₂And the like.

In the formula (a-1), D represents a bond R¹And a linking group of Si (wherein, alkylene is excluded) or a single bond.

Examples of the linking group of D include: and arylene groups having 6 to 20 carbon atoms such as 1, 4-phenylene, 1, 3-phenylene, 1, 2-phenylene, and 1, 5-naphthylene.

The curable polysilsesquioxane compound (A) may have 1 type of (R)¹The compound (homopolymer) of (E) -D), may have 2 or more (R)¹A compound (copolymer) of (D).

When the curable polysilsesquioxane compound (a) is a copolymer, the curable polysilsesquioxane compound (a) may be any of a random copolymer, a block copolymer, a graft copolymer, an alternating copolymer, and the like, and a random copolymer is preferable from the viewpoint of ease of production and the like.

The structure of the curable polysilsesquioxane compound (a) may be any of a ladder structure, a double-layer structure, a cage structure, a partially split cage structure, a cyclic structure, and a random structure.

The proportion of the repeating unit represented by the formula (a-1) contained in the curable polysilsesquioxane compound (a) is preferably 25mol% or more, more preferably 25 to 90mol%, and still more preferably 25 to 85mol% based on the total repeating units.

By using the curable polysilsesquioxane compound (A) in which the proportion of the repeating unit represented by the formula (a-1) is 25mol% or more based on the total repeating units, a curable composition having a lower refractive index can be obtained.

The curable polysilsesquioxane compound (a) may be a polymer (copolymer) further having a repeating unit represented by the following formula (a-2).

[ chemical formula 4]

In the formula (a-2), R²Represents an unsubstituted alkyl group having 1 to 10 carbon atoms or an unsubstituted aryl group having 6 to 12 carbon atoms.

As R²The unsubstituted alkyl group having 1 to 10 carbon atoms includes: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, and the like.

As R²The unsubstituted aryl group having 6 to 12 carbon atoms includes: phenyl, 1-naphthyl, 2-naphthyl, and the like.

As R²The substituent of the aryl group having 6 to 12 carbon atoms and having a substituent(s) includes: an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, and an isooctyl group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, etc.; alkoxy groups such as methoxy and ethoxy.

Among these, as R²In view of the ease of obtaining a cured product having higher adhesive strength and more excellent heat resistance, the alkyl group having 1 to 10 carbon atoms is preferably unsubstituted, the alkyl group having 1 to 6 carbon atoms is more preferably unsubstituted, and the alkyl group having 1 to 3 carbon atoms is particularly preferably unsubstituted.

When the curable polysilsesquioxane compound (A) is a compound having a repeating unit represented by the formula (a-2), the curable polysilsesquioxane compound (A) is a curable polysilsesquioxane compoundThe alkyl compound (A) may have 1R²The compound of (1) may have 2 or more kinds of R²The compound of (1).

When the curable polysilsesquioxane compound (a) is a compound having a repeating unit represented by the formula (a-2), the proportion thereof is preferably more than 0mol% and 75mol% or less, more preferably 10 to 75mol%, and still more preferably 15 to 75mol% with respect to all repeating units.

By using the curable polysilsesquioxane compound (a) in which the proportion of the repeating unit represented by the formula (a-2) is within the above-described range, a cured product having higher adhesive strength and more excellent heat resistance can be easily obtained.

The ratio of the repeating unit represented by the formula (a-1) or the formula (a-2) in the curable polysilsesquioxane compound (A) can be determined, for example, by measuring the content of the curable polysilsesquioxane compound (A)²⁹Si-NMR.

The curable polysilsesquioxane compound (a) is soluble in the following various organic solvents: 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 a mixed solvent comprising 2 or more of them, and the like, and thus the curable polysilsesquioxane compound (A) in a solution state can be measured using these solvents²⁹Si-NMR。

The repeating unit represented by the formula (a-1) or the repeating unit represented by the formula (a-2) is a repeating unit represented by the following formula (a-3).

[ chemical formula 5]

G represents (R)¹-D) or R²。R¹、D、R²Each means the same as described above. O is_1/2Indicates that the oxygen atom is common to the adjacent repeating units.

As shown in the formula (a-3), the curable polysilsesquioxane compound (a) has a partial structure in which 3 oxygen atoms are bonded to a silicon atom and 1 other group (group represented by G) is bonded thereto, which is generally collectively referred to as a T site.

Examples of the T site contained in the curable polysilsesquioxane compound (A) include T sites represented by the following formulae (a-4) to (a-6).

[ chemical formula 6]

In the formulae (a-4), (a-5) and (a-6), G represents the same meaning as described above. R³Represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. As R³The alkyl group having 1 to 10 carbon atoms includes: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, and the like. Plural R³May be the same or different from each other. In the above formulae (a-4) to (a-6), a silicon atom is bonded thereto.

The T sites represented by the formulae (a-4) and (a-5) contain a group (R) which can contribute to the polycondensation reaction³-O). Therefore, the polysilsesquioxane compound including a plurality of these T sites is excellent in reactivity. Further, a composition containing such a polysilsesquioxane compound is excellent in curability.

On the other hand, the T sites represented by the formulae (a-5) and (a-6) are bonded to 2 or more silicon atoms (silicon atoms in adjacent T sites). Therefore, polysilsesquioxane compounds containing a plurality of these T sites tend to have a large molecular weight.

Therefore, the polysilsesquioxane compound including a plurality of T sites represented by formula (a-5) has a large molecular weight and has sufficient reactivity.

The present invention is based on this finding.

That is, the curable polysilsesquioxane compound (a) of the present invention satisfies the following requirement 1.

[ element 1]

In the determination of curable polysilsesquioxane compounds²⁹Si-NMR in a region of-62 ppm or more and less than-52 ppm [ region (2) ]]Observe 1 or 2The peak is in a region of-52 ppm or more and less than-45 ppm [ region (1) ]]And a region of-73 ppm or more and less than-62 ppm [ region (3)]At least one region in the above (1) or (2) or more peaks are observed, and Z2 derived from the following formula is 20 to 40%.

The phrase "a peak observed in the region (1)" means that the peak top is in the range of the region (1). The same applies to "the peak observed in the region (2)" and "the peak observed in the region (3)".

[ mathematical formula 3]

P1: an integrated value in the region (1);

p2: an integrated value in the region (2);

p3: the integrated value in the area (3).

In the present specification, "integrated value in region (1)," integrated value in region (2), "and" integrated value in region (3) "refer to values calculated using-52 ppm to-45 ppm, -62ppm to-52 ppm, -73ppm to-62 ppm as integration ranges, respectively.

The peaks observed in the region (1), the region (2) and the region (3) are derived from silicon atoms in the T site represented by the formula (a-4), the formula (a-5) and the formula (a-6), respectively.

Therefore, the curable polysilsesquioxane compound satisfying requirement 1 contains 20 to 40% of T sites represented by formula (a-5) with respect to the total T sites.

As described above, the curable polysilsesquioxane compound has a relatively large molecular weight and sufficient reactivity, and therefore, can be used as a curable component of a curable composition.

In condition 1, the value of Z2 is preferably 24 to 36%, more preferably 27 to 32%. When Z2 is too small, the reactivity is insufficient, and when Z2 is too large, the storage stability is lowered.

The curable polysilsesquioxane compound (a) is preferably: in the determination of²⁹In Si-NMR, 1 or 2 or more peaks are observed in the region (3), and Z3 derived from the following formula is 60 to 80%.

[ mathematical formula 4]

The curable polysilsesquioxane compound (A) having a Z3 content of 60 to 80% comprises 60 to 80% of T sites represented by the formula (a-6) relative to the total T sites.

The curable polysilsesquioxane compound (A) having a value of Z3 in the range of 60 to 80% is more excellent in the balance between the molecular weight and the reactivity.

From the viewpoint of more easily obtaining this effect, the value of Z3 is more preferably 64 to 76%, and still more preferably 68 to 73%.

The value of Z2 or Z3 can be measured, for example, under the conditions described in the examples²⁹Si-NMR gave P1 to P3, which were then calculated according to the above formula.

The curable polysilsesquioxane compound (a) satisfies the above requirement 2.

That is, the mass average molecular weight (Mw) of the curable polysilsesquioxane compound (A) is 4,000 to 11,000, preferably 4,000 to 8,000, and more preferably 6,000 to 7,000.

As described above, the curable polysilsesquioxane compound satisfying requirement 1 tends to have a large molecular weight. The requirement 2 makes the molecular weight range clear.

By using the curable polysilsesquioxane compound (a) having a mass average molecular weight (Mw) within the above-described range as the curable component, a curable composition that gives a cured product having high adhesive strength and excellent heat resistance can be obtained.

The molecular weight distribution (Mw/Mn) of the curable polysilsesquioxane compound (A) is not particularly limited, but is usually in the range of 1.0 to 10.0, preferably 1.1 to 6.0. By using the curable polysilsesquioxane compound (a) having a molecular weight distribution (Mw/Mn) within the above-described range as the curable component, a curable composition that gives a cured product having more excellent adhesiveness and heat resistance can be obtained.

The mass average molecular weight (Mw) and the number average molecular weight (Mn) can be determined as standard polystyrene values based on Gel Permeation Chromatography (GPC) using Tetrahydrofuran (THF) as a solvent, for example.

The curable polysilsesquioxane compound (a) can be produced, for example, by polycondensing a compound represented by the following formula (a-7) (hereinafter, may be referred to as "silane compound (1)") or a silane compound (1) and a compound represented by the following formula (a-8) (hereinafter, may be referred to as "silane compound (2)") in the presence of a polycondensation catalyst.

[ chemical formula 7]

In the formulae (a-7), (a-8), R¹、R²And D represents the same meaning as described above. R⁴、R⁵Each independently represents an alkyl group having 1 to 10 carbon atoms, X¹、X²Each independently represents a halogen atom, and p and q each independently represent an integer of 0 to 3. Plural R⁴、R⁵And a plurality of X¹、X²May be respectively the same as or different from each other.

As R⁴、R⁵The alkyl group having 1 to 10 carbon atoms of (A) may be mentioned as R²The alkyl group having 1 to 10 carbon atoms is the same as the alkyl group given above.

As X¹、X²Examples of the halogen atom of (2) include: chlorine atom and bromine atom, etc.

Examples of the silane compound (1) include: CF (compact flash)₃Si(OCH₃)₃、CF₃CF₂Si(OCH₃)₃、CF₃CF₂CF₂Si(OCH₃)₃、CF₃CF₂CF₂CF₂Si(OCH₃)₃、CF₃CH₂CH₂Si(OCH₃)₃、CF₃CF₂CF₂CF₂CH₂CH₂Si(OCH₃)₃、CF₃CF₂CF₂CF₂CF₂CF₂CH₂CH₂Si(OCH₃)₃、CF₃CF₂CF₂CF₂CF₂CF₂CF₂CF₂CH₂CH₂Si(OCH₃)₃、CF₃(C₆H₄)Si(OCH₃)₃(4- (trifluoromethyl) phenyltrimethoxysilane), CF₃Si(OCH₂CH₃)₃、CF₃CF₂Si(OCH₂CH₃)₃、CF₃CF₂CF₂Si(OCH₂CH₃)₃、CF₃CF₂CF₂CF₂Si(OCH₂CH₃)₃、CF₃CH₂CH₂Si(OCH₂CH₃)₃、CF₃CF₂CF₂CF₂CH₂CH₂Si(OCH₂CH₃)₃、CF₃CF₂CF₂CF₂CF₂CF₂CH₂CH₂Si(OCH₂CH₃)₃、CF₃CF₂CF₂CF₂CF₂CF₂CF₂CF₂CH₂CH₂Si(OCH₂CH₃)₃、CF₃(C₆H₄)Si(OCH₂CH₃)₃Fluoroalkyl trialkoxysilane compounds such as 4- (trifluoromethyl) phenyltriethoxysilane;

CF₃SiCl(OCH₃)₂、CF₃CF₂SiCl(OCH₃)₂、CF₃CF₂CF₂SiCl(OCH₃)₂、CF₃SiBr(OCH₃)₂、CF₃CF₂SiBr(OCH₃)₂、CF₃CF₂CF₂SiBr(OCH₃)₂、

CF₃CF₂CF₂CF₂SiCl(OCH₃)₂、CF₃CH₂CH₂SiCl(OCH₃)₂、CF₃CF₂CF₂CF₂CH₂CH₂SiCl(OCH₃)₂、CF₃CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl(OCH₃)₂、CF₃CF₂CF₂CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl(OCH₃)₂、CF₃(C₆H₄)SiCl(OCH₃)₂4- (trifluoromethyl) phenylchlorodimethoxysilane, CF₃SiCl(OCH₂CH₃)₂、CF₃CF₂SiCl(OCH₂CH₃)₂、CF₃CF₂CF₂SiCl(OCH₂CH₃)₂、CF₃CF₂CF₂CF₂SiCl(OCH₂CH₃)₂、CF₃CH₂CH₂SiCl(OCH₂CH₃)₂、CF₃CF₂CF₂CF₂CH₂CH₂SiCl(OCH₂CH₃)₂、CF₃CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl(OCH₂CH₃)₂、CF₃CF₂CF₂CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl(OCH₂CH₃)₂、CF₃(C₆H₄)SiCl(OCH₂CH₃)₂Fluoroalkyl halogenodialkoxysilane compounds such as 4- (trifluoromethyl) phenylchlorodiethoxysilane;

CF₃SiCl₂(OCH₃)、CF₃CF₂SiCl₂(OCH₃)、CF₃CF₂CF₂SiCl₂(OCH₃)、CF₃CF₂CF₂CF₂SiCl₂(OCH₃)、CF₃CH₂CH₂SiCl₂(OCH₃)、CF₃CF₂CF₂CF₂CH₂CH₂SiCl₂(OCH₃)、CF₃CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl₂(OCH₃)、CF₃CF₂CF₂CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl₂(OCH₃)、CF₃(C₆H₄)SiCl₂(OCH₃) 4- (trifluoromethyl) phenyldichloromethoxysilane, CF₃SiCl₂(OCH₂CH₃)、CF₃CF₂SiCl₂(OCH₂CH₃)、CF₃CF₂CF₂SiCl₂(OCH₂CH₃)、CF₃CF₂CF₂CF₂SiCl₂(OCH₂CH₃)、CF₃CH₂CH₂SiCl₂(OCH₂CH₃)、CF₃CF₂CF₂CF₂CH₂CH₂SiCl₂(OCH₂CH₃)、CF₃CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl₂(OCH₂CH₃)₂、CF₃CF₂CF₂CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl₂(OCH₂CH₃)、CF₃(C₆H₄)SiCl₂(OCH₂CH₃) Fluoroalkyl dihaloalkoxy silane compounds such as 4- (trifluoromethyl) phenyldichloroethoxy silane;

CF₃SiCl₃、CF₃CF₂SiCl₃、CF₃SiBr₃、CF₃CF₂SiBr₃、CF₃CF₂CF₂SiCl₃、CF₃CF₂CF₂CF₂SiCl₃、CF₃CH₂CH₂SiCl₃、CF₃CF₂CF₂CF₂CH₂CH₂SiCl₃、CF₃CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl₃、CF₃CF₂CF₂CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl₃、CF₃(C₆H₄)SiCl₃4-trifluoromethylphenyltrichlorosilane, CF₃SiCl₃、CF₃CF₂SiCl₃、CF₃CF₂CF₂SiCl₃、CF₃CF₂CF₂CF₂SiCl₃、CF₃CH₂CH₂SiCl₃、CF₃CF₂CF₂CF₂CH₂CH₂SiCl₃、CF₃CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl₃、CF₃CF₂CF₂CF₂CF₂CF₂CF₂CF₂CH₂CH₂SiCl₃、CF₃(C₆H₄)SiCl₃Fluoroalkyl trihalosilane compounds such as 4- (trifluoromethyl) phenyltrichlorosilane.

The silane compound (1) may be used alone in 1 kind, or in combination of 2 or more kinds.

Among these, the silane compound (1) is preferably a silane compound contained in fluoroalkyl trialkoxy silane compounds.

Examples of the silane compound (2) include: alkyltrialkoxysilane compounds such as methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltripropoxysilane, n-propyltributoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, and isooctyltriethoxysilane;

alkylhaloalkoxysilane compounds such as methylchlorodimethoxysilane, methylchlorodiethoxysilane, methyldichlormethoxysilane, methylbromodimethoxysilane, ethylchlorodimethoxysilane, ethylchlorodiethoxysilane, ethyldichloromethoxysilane, ethylbromodimethoxysilane, n-propylchlorodimethoxysilane, n-propyldichloromethoxysilane, n-butylchlorodimethoxysilane and n-butyldichloromethoxysilane;

alkyltrihalosilane compounds such as methyltrichlorosilane, methyltrtribromosilane, ethyltrichlorosilane, ethyltribromosilane, n-propyltrichlorosilane, n-propyltribromosilane, n-butyltrichlorosilane, isobutyltrichlorosilane, n-pentyltrichlorosilane, n-hexyltrichlorosilane, and isooctyltrichlorosilane.

The silane compound (2) may be used alone in 1 kind, or in combination of 2 or more kinds.

Among these, the silane compound (2) is preferably a silane compound contained in alkyltrialkoxysilane compounds.

The method for polycondensing the silane compound is not particularly limited, and a known method can be used. However, the following problems are involved in the preparation of the curable polysilsesquioxane compound (a), and therefore, it is necessary to study the reaction conditions in particular.

One of the problems in the preparation of the curable polysilsesquioxane compound (a) is as shown in the above-mentioned patent document 4. That is, as can be seen from table 1 of patent document 4: as the use ratio of the silane compound having a fluoroalkyl group increases, the resulting polymer tends to have a low molecular weight.

Since the reactivity of the silane compound (1) and the reactivity of the silane compound (2) are greatly different from each other, it is difficult to obtain a curable polysilsesquioxane compound satisfying the requirements 1 and 2 by directly utilizing conventional findings relating to the polycondensation reaction of the silane compound (2).

In the examples of patent document 4, a polymer is actually produced by performing a polycondensation reaction using a silane compound having a fluoroalkyl group. However, as described above, in the production method described in this document, the mixing ratio of the silane compound used for the reaction greatly affects the reaction, and therefore the molecular weight of the polymer cannot be controlled.

As described later, by using the reaction conditions described in the examples of patent document 4, although it is possible to use a silane compound (silane compound having a fluoroalkyl group) having poor reactivity as a monomer, it is difficult to obtain a curable polysilsesquioxane compound satisfying requirements 1 and 2 even when the reaction conditions are used (comparative examples 1 to 3).

The present inventors have studied the polycondensation reaction using the silane compound (1), and as a result, they have found that: the curable polysilsesquioxane compound satisfying requirements 1 and 2 can be obtained by conducting the polycondensation reaction under relatively mild conditions over a long period of time.

Specifically, the curable polysilsesquioxane compound (a) can be produced by conducting a polycondensation reaction of a silane compound in a solvent or without a solvent at a predetermined temperature using an appropriate amount of an acid catalyst to obtain a reaction liquid containing a production intermediate, adding a base to neutralize the reaction liquid, and then conducting a polycondensation reaction.

Examples of the solvent include: water; aromatic hydrocarbons such as benzene, toluene, and xylene; esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and methyl propionate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, and tert-butanol. These solvents may be used alone in 1 kind, or in combination of 2 or more kinds.

In the case of using a solvent, the amount of the solvent used is usually 0.001 to 10.000 liters, preferably 0.010 to 0.9 liters, per 1mol of the total mol amount of the silane compounds.

As the acid catalyst, there can be mentioned: inorganic acids such as phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, and nitric acid; and organic acids such as citric acid, acetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. Among these, at least 1 selected from phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, citric acid, acetic acid and methanesulfonic acid is preferable.

The amount of the acid catalyst used is usually 0.01 to 2.00mol%, preferably 0.05 to 1.00mol%, and more preferably 0.10 to 0.30 mol% based on the total mol amount of the silane compound.

The reaction temperature in the presence of an acid catalyst is usually 20 to 90 ℃, preferably 25 to 80 ℃.

The reaction time in the presence of an acid catalyst is usually 1 to 48 hours, preferably 3 to 24 hours.

The mass average molecular weight (Mw) of the production intermediate obtained by the reaction in the presence of an acid catalyst is usually 800 to 5,000, preferably 1,200 to 4,000.

Examples of the base used for neutralizing the reaction solution include: ammonia water; organic bases such as trimethylamine, triethylamine, pyridine, 1, 8-diazabicyclo [5.4.0] -7-undecene, aniline, picoline, 1, 4-diazabicyclo [2.2.2] octane, imidazole and the like; organic salt hydroxides such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; metal alkoxides such as sodium methoxide, sodium ethoxide, sodium tert-butoxide, and potassium tert-butoxide; metal hydrides such as sodium hydride and calcium hydride; metal hydroxides such as sodium hydroxide, potassium hydroxide, and calcium hydroxide; metal carbonates such as sodium carbonate, potassium carbonate, and magnesium carbonate; and metal hydrogen carbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate.

The amount of the base used for neutralizing the reaction solution is usually in the range of 0.01 to 2.00mol%, preferably 0.05 to 1.00mol%, and more preferably 0.10 to 0.70, relative to the total mol amount of the silane compounds.

The amount (mol) of the base used for neutralizing the reaction solution is preferably 0.5 to 5.0 times, more preferably 0.8 to 3.0 times, and still more preferably 1.0 to 2.0 times the amount (mol) of the acid catalyst used before step 1.

The pH of the neutralized reaction solution is usually 6.0 to 8.0, preferably 6.2 to 7.0, and more preferably 6.4 to 6.9.

The reaction temperature of the reaction after neutralization is usually 40 to 90 ℃, preferably 50 to 80 ℃.

The reaction time of the reaction after neutralization is usually 20 to 200 minutes, preferably 30 to 150 minutes.

In the above-mentioned production method, hydrolysis is mainly aimed at the reaction in the presence of an acid catalyst, and dehydration condensation is mainly aimed at the reaction after neutralization.

By performing the polycondensation reaction of the silane compound in this manner, the objective curable polysilsesquioxane compound (a) can be produced with high efficiency.

After the reaction is completed, the curable polysilsesquioxane compound (a) may be isolated by performing a known purification treatment.

The curable polysilsesquioxane compound of the present invention is a compound having a repeating unit having a fluoroalkyl group, and has sufficient reactivity and a relatively large molecular weight.

Such a curable polysilsesquioxane compound is useful as a curable component of a curable composition having excellent curability and a low refractive index.

2) Curable composition

The curable composition of the present invention is characterized in that: contains the following component (A) and a solvent having a boiling point of 254 ℃ or higher (hereinafter, sometimes referred to as "solvent (S1)").

(A) The components: curable polysilsesquioxane Compound (A)

In the curable composition of the present invention, 1 kind of the curable polysilsesquioxane compound (a) may be used alone, or 2 or more kinds may be used in combination.

The curable polysilsesquioxane compound (a) is contained in the curable composition of the present invention in an amount of usually 40 to 80% by mass, preferably 50 to 70% by mass, based on the entire solid content of the curable composition.

The boiling point of the solvent (S1) is 254 ℃ or higher, preferably 254 to 300 ℃.

Herein, the boiling point means the boiling point at 1013hPa (synonymous in the present specification).

The solvent (S1) is not particularly limited as long as it has a boiling point of 254 ℃ or higher and can dissolve the curable polysilsesquioxane compound (a).

Such a solvent (S1) is relatively slow to evaporate. Therefore, the curable composition containing the solvent (S1) has a small change in viscosity even when left for a long time after application, and thus can fix (mount) an optical element or the like well as immediately after application.

Specific examples of the solvent (S1) include: tripropylene glycol-n-butyl ether (boiling point 274 ℃), 1, 6-hexanediol diacrylate (boiling point 260 ℃), diethylene glycol dibutyl ether (boiling point 256 ℃), triethylene glycol butyl methyl ether (boiling point 261 ℃), polyethylene glycol dimethyl ether (boiling point 264 to 294 ℃), tetraethylene glycol dimethyl ether (boiling point 275 ℃), polyethylene glycol monomethyl ether (boiling point 290 to 310 ℃), and the like.

Among these, as the solvent (S1), tripropylene glycol-n-butyl ether and 1, 6-hexanediol diacrylate are preferable from the viewpoint of more easily obtaining the effect of the present invention.

The solvent (S1) may be used alone in 1 kind or in combination of 2 or more kinds.

The curable composition of the present invention may contain a solvent other than the solvent (S1).

As the solvent other than the solvent (S1), a solvent having a boiling point of 200 ℃ or higher and lower than 254 ℃ is preferable (hereinafter, sometimes referred to as "solvent (S2)").

The solvent (S2) is not particularly limited, and may be any solvent having a boiling point of 200 ℃ or higher and lower than 254 ℃ and capable of dissolving the curable polysilsesquioxane compound (a).

The curability of the curable composition is improved by using the solvent (S1) and the solvent (S2) in combination.

Specific examples of the solvent (S2) include: diethylene glycol monobutyl ether acetate (boiling point 247 ℃ C.), dipropylene glycol-n-butyl ether (boiling point 229 ℃ C.), benzyl alcohol (boiling point 204.9 ℃ C.), dipropylene glycol methyl ether acetate (boiling point 209 ℃ C.), diethylene glycol butyl methyl ether (boiling point 212 ℃ C.), dipropylene glycol-n-propyl ether (boiling point 212 ℃ C.), tripropylene glycol dimethyl ether (boiling point 215 ℃ C.), triethylene glycol dimethyl ether (boiling point 216 ℃ C.), diethylene glycol monoethyl ether acetate (boiling point 217.4 ℃ C.), diethylene glycol-n-butyl ether (boiling point 230 ℃ C.), ethylene glycol monophenyl ether (boiling point 245 ℃ C.), tripropylene glycol methyl ether (boiling point 242 ℃ C.), propylene glycol phenyl ether (boiling point 243 ℃ C.), triethylene glycol monomethyl ether (boiling point 249 ℃ C.), and the like.

Among these, the solvent (S2) is preferably a glycol-based solvent, preferably diethylene glycol monobutyl ether acetate or dipropylene glycol-n-butyl ether, and more preferably diethylene glycol monobutyl ether acetate, from the viewpoint of easily obtaining the effects thereof.

In the case of using the solvent (S1) and the solvent (S2) in combination, specifically, the following combination is preferable: a combination of tripropylene glycol-n-butyl ether (solvent (S1)) and diethylene glycol monobutyl ether acetate (solvent (S2)), a combination of 1, 6-hexanediol diacrylate (solvent (S1)) and diethylene glycol monobutyl ether acetate (solvent (S2)), a combination of tripropylene glycol-n-butyl ether (solvent (S1)) and dipropylene glycol-n-butyl ether (solvent (S2)), and a combination of 1, 6-hexanediol diacrylate (solvent (S1)) and dipropylene glycol-n-butyl ether (organic solvent (S2)).

The curable composition of the present invention contains a solvent in an amount of preferably 50 to 95% by mass, more preferably 60 to 85% by mass, in terms of solid content concentration. Since the solid content concentration is within this range, the effect of the solvent (S1) or the solvent (S2) can be sufficiently exhibited.

The total amount of the solvent (S1) and the solvent (S2) contained in the curable composition of the present invention is usually 50 to 100% by mass, preferably 70 to 100% by mass, and more preferably 90 to 100% by mass, based on the total amount of all solvents.

The content of the solvent (S1) in the curable composition of the present invention is usually 20 to 100 mass%, preferably 30 to 85 mass%, and more preferably 50 to 80 mass% with respect to the total amount of the solvent (S1) and the solvent (S2).

The curable composition containing the solvent (S1) or the solvent (S2) in such a ratio has a proper balance between adhesiveness and wet spreadability (characteristics relating to spreading of droplets described later).

The curable composition of the present invention may contain, as the component (B), a silane coupling agent having a nitrogen atom in the molecule (hereinafter, sometimes referred to as "silane coupling agent (B)").

The curable composition containing the silane coupling agent (B) is excellent in workability in the coating step, and can give a cured product having further excellent adhesiveness, peeling resistance, and heat resistance.

Here, the excellent workability in the coating step means that the amount of wire drawing is small or the wire drawing is immediately interrupted when the curable composition is discharged from the discharge pipe in the coating step and then the discharge pipe is pulled. By using the curable composition having such properties, contamination of the surroundings due to scattering of the resin or spreading of liquid droplets can be prevented.

The silane coupling agent (B) is not particularly limited as long as it has a nitrogen atom in the molecule. Examples thereof include: trialkoxysilane compounds represented by the following formula (b-1), dialkoxyalkylsilane compounds represented by the following formula (b-2), dialkoxyarylsilane compounds, and the like.

[ chemical formula 8]

In the above formula, R^aRepresents 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, a tert-butoxy group, or the like. Plural R^aMay be the same or different from each other.

R^bRepresents: alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, and the like; or an aryl group having a substituent or no substituent such as phenyl, 4-chlorophenyl, 4-methylphenyl, 1-naphthyl and the like.

R^cRepresents an organic group (organic group) having 1 to 10 carbon atoms and having a nitrogen atom. In addition, R^cMay be further bonded to groups containing other silicon atoms.

As R^cSpecific examples of the organic group having 1 to 10 carbon atoms include: n-2- (aminoethyl) -3-aminopropyl, N- (1, 3-dimethyl-butylene) aminopropyl, 3-ureidopropyl, N-phenyl-aminopropyl and the like.

In the compound represented by the above formula (b-1) or (b-2), R is^cExamples of the compound in the case of an organic group bonded to a group containing another silicon atom include: via the isocyanurate skeleton and othersA compound in which silicon atoms are bonded to form an isocyanurate-based silane coupling agent, or a compound in which silicon atoms are bonded to other silicon atoms through a urea skeleton to form a urea-based silane coupling agent.

Among these, the silane coupling agent (B) is preferably an isocyanurate-based silane coupling agent or a urea-based silane coupling agent, and more preferably a silane coupling agent having 4 or more alkoxy groups bonded to silicon atoms in the molecule, from the viewpoint of easily obtaining a cured product having higher adhesive strength.

The alkoxy group having 4 or more atoms bonded to silicon 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 4 or more alkoxy groups bonded to a silicon atom include: as the urea-based silane coupling agent having 4 or more alkoxy groups bonded to a silicon atom, a compound represented by the following formula (b-3) is exemplified: a compound represented by the following formula (b-4).

[ chemical formula 9]

In the formula, R^aThe same meanings as described above are indicated. t1 to t5 each independently represent an integer of 1 to 10, preferably an integer of 1 to 6, and particularly preferably 3.

Specific examples of the compound represented by the formula (b-3) include: 1,3, 5-N-tris [ (tri (1 to 6 carbon atoms) alkoxy) silyl (1 to 10 carbon atoms) alkyl ] isocyanurate such as 1,3, 5-N-tris (3-trimethoxysilylpropyl) isocyanurate, 1,3, 5-N-tris (3-triisopropoxysilylpropyl) isocyanurate, 1,3, 5-N-tris (3-tributoxysilylpropyl) isocyanurate;

1,3, 5-N-tris (3-dimethoxymethylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-dimethoxyethylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-dimethoxyisopropylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-dimethoxy-N-propylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-dimethoxyphenylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-diethoxymethylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-diethoxyethylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-diethoxyisopropylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-diethoxyn-propylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-diethoxyphenylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-diisopropoxymethylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-diisopropoxyethylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-diisopropoxylisopropylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-diisopropoxyesopropylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-diisopropoxyphenylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-dibutoxymethylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-dibutoxyethylsilylpropyl) isocyanurate, 1,3, 5-N-tris [ (di (C1-6) alkoxy) silyl (C1-10) alkyl ] isocyanurate such as 1,3, 5-N-tris (3-dibutoxy-N-propylsilylpropyl) isocyanurate, 1,3, 5-N-tris (3-dibutoxyphenylsilylpropyl) isocyanurate and the like.

Specific examples of the compound represented by the formula (b-4) include: n, N ' -bis [ (tri (C1-6) alkoxysilyl) (C1-10) alkyl ] urea such as N, N ' -bis (3-trimethoxysilylpropyl) urea, N ' -bis (3-triethoxysilylpropyl) urea, N ' -bis (3-tripropoxysilylpropyl) urea, N ' -bis (2-trimethoxysilylethyl) urea;

n, N '-bis [ (di (C1-6) alkoxy (C1-6) alkylsilyl (C1-10) alkyl) urea such as N, N' -bis (3-dimethoxymethylsilylpropyl) urea, N '-bis (3-dimethoxyethylsilylpropyl) urea, and N, N' -bis (3-diethoxymethylsilylpropyl) urea;

n, N ' -bis [ (di (C1-6) alkoxy (C6-20) arylsilyl (C1-10) alkyl) urea such as N, N ' -bis (3-dimethoxyphenylsilylpropyl) urea or N, N ' -bis (3-diethoxyphenylsilylpropyl) urea.

The silane coupling agent (B) may be used alone in 1 kind, or in combination with 2 or more kinds.

Among these, as the silane coupling agent (B), it is preferable to use: 1,3, 5-N-tris (3-trimethoxysilylpropyl) isocyanurate, 1,3, 5-N-tris (3-triethoxysilylpropyl) isocyanurate (hereinafter, referred to as "isocyanurate compound"), N '-bis (3-trimethoxysilylpropyl) urea, N' -bis (3-triethoxysilylpropyl) urea (hereinafter, referred to as "urea compound"), and a combination of the above isocyanurate compound and urea compound.

In the case of using the isocyanurate compound and the urea compound in combination, the ratio of the both is preferably 100: 1-100: 200. more preferably 100: 10-100: 110. by using an isocyanurate compound and a urea compound in combination at such a ratio, a curable composition which gives a cured product having higher adhesive strength and more excellent heat resistance can be obtained.

When the curable composition of the present invention contains a silane coupling agent (B) [ (B) component ], the content of the (B) component is not particularly limited, and the amount thereof is determined by the mass ratio of the (a) component to the (B) component [ (a) component: (B) component ] is preferably 100: 0.1 to 100: 90. more preferably 100: 0.3-100: 60. more preferably 100: 1-100: 50. more preferably 100: 3-100: 40. particularly preferably 100: 5-100: 30, in an amount of less than 30.

A cured product of the curable composition containing the components (a) and (B) in such a ratio has higher adhesive strength and more excellent heat resistance.

The curable composition of the present invention may contain, as the component (C), a silane coupling agent having an acid anhydride structure in the molecule (hereinafter, sometimes referred to as "silane coupling agent (C)").

The curable composition containing the silane coupling agent (C) is excellent in workability in the coating step, and can give a cured product having higher adhesive strength and more excellent peeling resistance and heat resistance.

Examples of the silane coupling agent (C) include: tri (C1-C6) alkoxysilyl (C2-C8) alkylsuccinic anhydrides such as 2- (trimethoxysilyl) ethylsuccinic anhydride, 2- (triethoxysilyl) ethylsuccinic anhydride, 3- (trimethoxysilyl) propylsuccinic anhydride and 3- (triethoxysilyl) propylsuccinic anhydride;

di (C1-C6) alkoxymethylsilyl (C2-C8) alkylsuccinic anhydride such as 2- (dimethoxymethylsilyl) ethylsuccinic anhydride;

(C1-C6) alkoxydimethylsilyl (C2-C8) alkylsuccinic anhydride such as 2- (methoxymethylsilyl) ethylsuccinic anhydride;

trihalosilyl (C2-C8) alkyl succinic anhydrides such as 2- (trichlorosilyl) ethyl succinic anhydride and 2- (tribromosilyl) ethyl succinic anhydride;

dihalomethylsilyl (having 2 to 8 carbon atoms) alkylsuccinic anhydrides such as 2- (dichloromethylsilyl) ethylsuccinic anhydride;

and halogenated dimethylsilyl (C2-C8) alkyl succinic anhydrides such as 2- (chlorodimethylsilyl) ethyl succinic anhydride.

The silane coupling agent (C) may be used alone in 1 kind, or in combination with 2 or more kinds.

Among these, the silane coupling agent (C) is preferably a tri (C1-6) alkoxysilyl (C2-8) alkylsuccinic anhydride, and particularly preferably 3- (trimethoxysilyl) propylsuccinic anhydride or 3- (triethoxysilyl) propylsuccinic anhydride.

When the curable composition of the present invention contains a silane coupling agent (C) [ (C) component ], the content of the (C) component is not particularly limited, and the amount thereof is determined by the mass ratio of the (a) component to the (C) component [ (a) component: (C) component ] is preferably 100: 0.1 to 100: 30. more preferably 100: 0.3-100: 20. more preferably 100: 0.5-100: 15. more preferably 100: 1-100: 10, in a quantity of 10.

The cured product of the curable composition containing the component (C) in such a ratio has higher adhesive strength.

The curable composition of the present invention may contain, as the component (D), fine particles having an average primary particle diameter of 5 to 40nm (hereinafter, sometimes referred to as "fine particles (D)").

The curable composition containing the fine particles (D) is excellent in workability in the coating step.

From the viewpoint of more easily obtaining the effect, the average primary particle diameter of the fine particles (D) is preferably 5 to 30nm, more preferably 5 to 20 nm.

The average primary particle diameter of the fine particles (D) can be determined by observing the shape of the fine particles using a transmission electron microscope.

The specific surface area of the fine particles (D) is preferably 10 to 500m²A concentration of 20 to 300m²(ii) in terms of/g. Since the specific surface area is within the above range, a curable composition having more excellent workability in the coating step can be easily obtained.

The specific surface area can be determined by the BET multipoint method.

The shape of the fine particles (D) may be any of spherical, chain, needle, plate, sheet, rod, fiber, etc., and is preferably spherical. Here, the spherical shape means not only a spherical shape but also an approximately spherical shape including a spheroid shape that can be approximated to a sphere, such as a spheroid, an oval shape, a candy shape, a cocoon shape, and the like.

The constituent components of the fine particles (D) are not particularly limited, and include: a metal; a metal oxide; minerals; metal carbonates such as calcium carbonate and magnesium carbonate; metal sulfates such as calcium sulfate and barium sulfate; metal hydroxides such as aluminum hydroxide; metal silicates such as aluminum silicate, calcium silicate, and magnesium silicate; inorganic components such as silica; an organosilicon; organic components such as acrylic polymers.

In addition, the particles (D) used may be particles whose surfaces have been modified.

The metal is an element belonging to group 1 (excluding H), 2 to 11, 12 (excluding Hg), 13 (excluding B), 14 (excluding C and Si), 15 (excluding N, P, As and Sb), or 16 (excluding O, S, Se, Te and Po) in the periodic table.

Examples of the metal oxide include: titanium oxide, aluminum oxide, boehmite, chromium oxide, nickel oxide, copper oxide, titanium oxide, zirconium oxide, indium oxide, zinc oxide, and composite oxides thereof, and the like. The fine particles of metal oxide also include sol particles composed of these metal oxides.

Examples of the mineral include: smectite, bentonite, etc.

Examples of smectites include: montmorillonite, beidellite, hectorite, saponite, stevensite, nontronite, sauconite, and the like.

Examples of the silica include: dry silica, wet silica, surface-modified silica (silica whose surface has been modified), and the like.

The fine particles (D) may be used alone in 1 kind or in combination of 2 or more kinds.

Among these, silica, metal oxides, and minerals are preferable, and silica is more preferable as the fine particles (D) from the viewpoint of easily obtaining a cured product excellent in transparency.

Among the silicas, surface-modified silicas are preferable, and hydrophobic surface-modified silicas are more preferable, from the viewpoint of easily obtaining a curable composition having more excellent workability in the coating step.

Examples of the hydrophobic surface-modified silica include: silica having a surface to which a tri (C1-20) trialkylsilyl group such as a trimethylsilyl group, a di (C1-20 alkyl) silyl group such as a dimethylsilyl group, or an alkylsilyl group having 1-20 carbon atoms such as an octylsilyl group is bonded; silica obtained by treating the surface with silicone oil, and the like.

The hydrophobic surface-modified silica can be obtained, for example, by surface-modifying silica particles with a silane coupling agent such as a trialkylsilyl group having three (1 to 20 carbon atoms), a di (alkyl group having 1 to 20 carbon atoms) silyl group, or an alkylsilyl group having 1 to 20 carbon atoms, or by treating silica particles with a silicone oil. Further, commercially available surface-modified silica may be used as it is.

When the curable composition of the present invention contains fine particles (D) [ (D) component ], the content of the (D) component is not particularly limited, and the amount thereof is determined by the mass ratio of the (a) component to the (D) component [ (a) component: (D) component ] is preferably 100: 0.1 to 100: 90. more preferably 100: 0.2-100: 60. more preferably 100: 0.3-100: 50. more preferably 100: 0.5-100: 40. more preferably 100: 0.8-100: 30, in an amount of less than 30. By using the component (D) in the above range, the effect of adding the component (D) can be more exhibited.

The curable composition of the present invention may contain an average primary particle diameter of more than 0.04μm is 8μFine particles of m or less (hereinafter, sometimes referred to as "fine particles (E)") are used as the component (E).

By using the curable composition containing the fine particles (E), a cured product having excellent peeling resistance can be formed.

From the viewpoint of easily obtaining the effect, the average primary particle diameter of the fine particles (E) is preferably 0.06 to 7μm, more preferably 0.3 to 6μm, more preferably 0.5 to 4μm。

The average primary particle diameter of the fine particles (E) can be determined by measuring the particle size distribution by a laser light scattering method using a laser light diffraction/scattering particle size distribution measuring apparatus (for example, product name "LA-920" manufactured by horiba ltd.).

The shape of the fine particles (E) may be any of spherical, chain, needle, plate, sheet, rod, fiber, etc., and is preferably spherical. Here, the spherical shape means not only a spherical shape but also an approximately spherical shape including a spheroid shape that can be approximated to a sphere, such as a spheroid, an oval shape, a candy shape, a cocoon shape, and the like.

The constituent components of the fine particles (E) include the same components as those exemplified as the constituent components of the fine particles (D).

The fine particles (E) may be used alone in 1 kind or in combination of 2 or more kinds.

Among these, from the viewpoint of easily obtaining the above-mentioned effects, the fine particles (E) are preferably at least one fine particle selected from the group consisting of a metal oxide whose surface is covered with silicone, silica and silicone, and more preferably silica and silicone.

When the curable composition of the present invention contains fine particles (E) [ (E) component ], the content of the (E) component is not particularly limited, and the amount thereof is determined by the mass ratio of the (a) component to the (E) component [ (a) component: (E) component ] is preferably 100: 0.1 to 100: 40. more preferably 100: 0.2-100: 30. more preferably 100: 0.3-100: 20. more preferably 100: 0.5-100: 15. more preferably 100: 0.8-100: 12, in the total amount. By using the component (E) in the above range, the effect of adding the component (E) can be more exhibited.

The curable composition of the present invention may contain other components (component (F)) than the above-mentioned components (A) to (E) within a range not to impair the object of the present invention.

Examples of the component (F) include: antioxidants, ultraviolet absorbers, light stabilizers, and the like.

The antioxidant is added to prevent oxidative deterioration during heating. As the antioxidant, there may be mentioned: phosphorus antioxidants, phenol antioxidants, sulfur antioxidants, and the like.

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

These antioxidants may be used singly or in combination of two or more. The amount of the antioxidant used is usually 10% by mass or less based on the 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.

The ultraviolet absorber may be used alone or in combination of two or more.

The amount of the ultraviolet absorber used is usually 10% by mass or less based on the component (A).

The light stabilizer is added for the purpose of improving the light resistance of the resulting cured product.

Examples of the light stabilizer include: and hindered amines such as poly [ {6- (1,1,3,3, -tetramethylbutyl) amino-1, 3, 5-triazine-2, 4-diyl } { (2,2,6, 6-tetramethyl-4-piperidine) imino } hexamethylene { (2,2,6, 6-tetramethyl-4-piperidine) imino } ].

These light stabilizers may be used singly or in combination of two or more.

The total amount of the component (F) used is usually 20% by mass or less based on the component (A).

The curable composition of the present invention can be prepared, for example, by mixing the component (a) and the solvent (S1) at a predetermined ratio, and if necessary, mixing and degassing components other than these.

The mixing method and the defoaming method are not particularly limited, and known methods can be used.

The curable composition of the present invention contains a curable polysilsesquioxane compound (a). Therefore, the curable composition of the present invention has excellent curability and a low refractive index. The curable composition of the present invention is also useful as a material for forming a cured product having high adhesive strength.

The refractive index (nD) of the curable composition of the present invention at 25 ℃ is usually 1.380 to 1.434, preferably 1.380 to 1.430, more preferably 1.380 to 1.428, and still more preferably 1.380 to 1.425.

The refractive index (nD) of the curable composition can be measured by the method described in examples.

The curable composition of the present invention further contains a solvent (S1). Therefore, even if the curable composition of the present invention is left for a long time after application, the optical element can be fixed and the like in the same manner as immediately after application.

For example, the curable composition of the present invention can be applied in the same manner as immediately after application, even after the lapse of usually 20 minutes or more, preferably 30 minutes or more, and more preferably 60 minutes or more.

3) Cured product

The cured product of the present invention is obtained by curing the curable composition of the present invention.

The curable composition of the present invention can be cured by heating. The heating temperature during curing is usually 100 to 200 ℃ and the heating time is usually 10 minutes to 20 hours, preferably 30 minutes to 10 hours.

The cured product of the present invention has high adhesive strength and excellent heat resistance.

The cured product of the present invention has these properties, and 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, and the applied surface is placed on an adherend, and subjected to pressure bonding and heat treatment to be cured. The sample was allowed to stand on a measuring table of a bond tester (bond tester) previously heated to a predetermined temperature (e.g., 23 ℃ C., 100 ℃ C.) for 30 seconds from 50 ℃ to the adherendμThe adhesive surface was stressed in the horizontal direction (shear direction) at the position of m height, and the adhesion between the test piece and the adherend was measured.

The adhesion of the cured product of the present invention is preferably 60N/4mm at 23 ℃²Above, more preferably 80N/4mm²Above, particularly preferably 100N/4mm²The above. The adhesion of the cured product is preferably 30N/4mm at 100 DEG C²Above, more preferably 40N/4mm²Above, more preferably 50N/4mm²Above, particularly preferably 60N/4mm²The above.

In this specification, "4 mm²"means 2mm by 2mm (square with sides of 2 mm).

The cured product of the present invention is preferably used as an optical element-fixing material because of the above-mentioned properties.

4) Method for 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 the optical element include: light emitting elements such as LEDs and LDs, light receiving elements, composite optical elements, and optical integrated circuits.

< adhesive for optical element-fixing Material >

The curable composition of the present invention can be suitably used as an adhesive for optical element-fixing materials.

Examples of the method for using the curable composition of the present invention as an adhesive for optical element-fixing materials include: a method of applying the composition to one or both bonding surfaces of materials to be bonded (optical elements, substrates thereof, and the like), pressing the materials, and then heating and curing the materials to be bonded to strongly bond the materials to be bonded to each other. The amount of the curable composition of the present invention to be applied is not particularly limited, and may be an amount that can strongly bond materials to be bonded to each other by curing. Usually, the thickness of the coating film of the curable composition is 0.5 to 5μm is preferably 1 to 3μThe amount of m.

As a substrate material for bonding an optical element, there are listed: glasses such as soda-lime glass and heat-resistant hard glass; a ceramic; sapphire; metals such as iron, copper, aluminum, gold, silver, platinum, chromium, titanium, and alloys of these metals, stainless steel (SUS302, SUS304L, SUS309, etc.); and synthetic resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ethylene-vinyl acetate copolymers, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyetheretherketone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyimide, polyamide, acrylic resins, norbornene resins, cycloolefin resins, and glass epoxy resins.

The heating temperature during the heat curing is generally 100 to 200 ℃ although it depends on the curable composition used, etc. 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 can be suitably used as a sealing material for an optical device fixing material.

Examples of the method for using the curable composition of the present invention as a sealing material for an optical element-fixing material include: and a method for producing an optical element sealing body by molding the composition into a desired shape to obtain a molded body encapsulating an optical element and then heating and curing the molded body.

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 general transfer molding method or a casting method can be used.

The heating temperature during the heat curing is generally 100 to 200 ℃ although it depends on the curable composition used, etc. The heating time is usually 10 minutes to 20 hours, preferably 30 minutes to 10 hours.

The obtained optical element sealing body is excellent in heat resistance and high in adhesive strength because the curable composition of the present invention is used.

Examples

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

Unless otherwise specified, parts and% in each example are based on mass.

(example 1)

A300 mL eggplant-shaped flask was charged with 17.0g (77.7mmol) of 3,3, 3-trifluoropropyltrimethoxysilane and 32.33g (181.3mmol) of methyltriethoxysilane, and an aqueous solution prepared by dissolving 0.0675g of 35% hydrochloric acid (0.65 mmol of HCl, 0.25mol% based on the total amount of silane compounds) in 14.0g of distilled water was added thereto with stirring, and the whole was stirred at 30 ℃ for 2 hours, and then heated to 70 ℃ and stirred for 20 hours.

While continuing to stir the contents, 0.0394g of 28% ammonia (NH) was added thereto₃In an amount of 0.65mmol) and 46.1g of propyl acetateThe reaction mixture was stirred at 70 ℃ for 60 minutes while keeping the pH of the reaction mixture at 6.9.

After the reaction solution was allowed to cool to room temperature, 50g of propyl acetate and 100g of water were added thereto to conduct a liquid separation treatment, thereby obtaining an organic layer containing a reaction product. Magnesium sulfate was added to the organic layer, and drying treatment was performed. After magnesium sulfate was removed by filtration, the organic layer was concentrated by an evaporator, and then the obtained concentrate was dried in vacuum, whereby a curable polysilsesquioxane compound (1) was obtained.

100 parts of a curable polysilsesquioxane compound (1) were added 20 parts of a silica filler having an average primary particle diameter of 7nm and 10 parts of a silica filler having an average primary particle diameter of 0.8μm of a silicone filler. Then 30 parts of diethylene glycol monobutyl ether acetate as solvent were added: tripropylene glycol-n-butyl ether = 40: 60 (mass ratio), and then stirring the whole.

After dispersion treatment using a three-roll mill, 30 parts of 1,3, 5-N-tris [3- (trimethoxysilyl) propyl ] isocyanurate, 3 parts of 3- (trimethoxysilyl) propyl succinic anhydride, and diethylene glycol monobutyl ether acetate as a solvent were added: tripropylene glycol-n-butyl ether = 40: 60 parts by mass of the solvent mixture was thoroughly mixed and the whole was degassed to obtain a curable composition (1) having a solid content concentration of 82%.

(example 2)

A curable polysilsesquioxane compound (2) and a curable composition (2) were obtained in the same manner as in example 1, except that the stirring time after the addition of the 28% mixed solution of aqueous ammonia and propyl acetate was changed to 120 minutes.

(example 3)

A curable polysilsesquioxane compound (3) and a curable composition (3) were obtained in the same manner as in example 1, except that the stirring time after the addition of the 28% mixed solution of aqueous ammonia and propyl acetate was changed to 90 minutes.

(example 4)

A curable polysilsesquioxane compound (4) and a curable composition (4) were obtained in the same manner as in example 1, except that the stirring time after the addition of the 28% mixed solution of aqueous ammonia and propyl acetate was changed to 50 minutes.

(example 5)

A curable polysilsesquioxane compound (5) and a curable composition (5) were obtained in the same manner as in example 1, except that the stirring time after the addition of the 28% mixed solution of aqueous ammonia and propyl acetate was changed to 40 minutes.

Comparative example 1

According to the method of example 8 of WO2017/110948, a curable polysilsesquioxane compound (6) was obtained.

Then, 20 parts of a silica filler having an average primary particle diameter of 7nm and 10 parts of a silica filler having an average primary particle diameter of 0.8 were added to 100 parts of the curable polysilsesquioxane compound (6)μm of a silicone filler. Further, 30 parts of diethylene glycol monobutyl ether acetate was added as a solvent, and then the whole was stirred.

After dispersion treatment using a three-roll mill, 10 parts of 1,3, 5-N-tris [3- (trimethoxysilyl) propyl ] were added]Isocyanurate, 3 parts of 3- (trimethoxysilyl) propylsuccinic anhydride, and a viscosity measured at 25 ℃ for 200 seconds using an E-type viscometer^-1Diethylene glycol monobutyl ether acetate was added so that the viscosity reached 4.5 pas when measured under the conditions (1), and the entire contents were thoroughly mixed and deaerated, thereby obtaining a curable composition (6).

In paragraph (0115) of WO2017/110948, the amount of hydrochloric acid used is described as "0.25 mol% based on the total amount of silane compound", but it is accurate to "about 1.6mol% based on the total amount of silane compound" when calculated from the amount charged. The same applies to comparative examples 2 and 3 below.

Comparative example 2

According to the method of example 9 of WO2017/110948, a curable polysilsesquioxane compound (7) was obtained.

Then, a curable composition (7) was obtained in the same manner as in comparative example 1.

Comparative example 3

According to the method of example 10 of WO2017/110948, a curable polysilsesquioxane compound (8) was obtained.

Then, a curable composition (8) was obtained in the same manner as in comparative example 1.

Comparative example 4

71.37g (400mmol) of methyltriethoxysilane was charged into a 300mL eggplant-shaped flask, and while stirring, an aqueous solution prepared by dissolving 0.1g of 35% hydrochloric acid (0.25 mol% based on the total amount of silane compounds) in 21.6g of distilled water was added, and the whole was stirred at 30 ℃ for 2 hours, then heated to 70 ℃ and stirred for 5 hours.

While the contents were further stirred, 140g of propyl acetate and 0.12g of 28% aqueous ammonia (NH relative to the total amount of silane compounds) were added thereto₃0.5mol%), and stirred at 70 ℃ for 3 hours.

After the reaction solution was cooled to room temperature, the organic layer was washed with purified water until the pH of the aqueous layer was 7.

The organic layer was concentrated by an evaporator, and the concentrate was dried in vacuum, whereby a curable polysilsesquioxane compound (9) was obtained.

Then, a curable composition (9) was obtained in the same manner as in example 1.

Comparative example 5

A curable polysilsesquioxane compound (10) and a curable composition (10) were obtained in the same manner as in example 1, except that the stirring time after the addition of the 28% mixed solution of aqueous ammonia and propyl acetate was changed to 240 minutes.

The curable polysilsesquioxane compounds (1) to (10) and the curable compositions (1) to (10) obtained in examples and comparative examples were used for the following measurements and tests, respectively. The results are shown in Table 1.

[ measurement of Mass average molecular weight ]

The mass average molecular weight (Mw) of the curable polysilsesquioxane compound was measured using the following apparatus and conditions.

Device name: HLC-8220GPC, manufactured by Tosoh corporation;

column: sequentially connecting TSKgelGMHXL, TSKgelGMHXL and TSKgel2000 HXL;

solvent: tetrahydrofuran;

standard substance: polystyrene;

injection amount: 20μl；

Measuring temperature: 40 ℃;

flow rate: 0.6 ml/min;

a detector: a differential refractometer.

[²⁹Si-NMR measurement]

The device comprises the following steps: AV-500 manufactured by Bruker BioSpin;

²⁹Si-NMR resonance frequency: 99.352 MHz;

and (3) probe: 5mmϕA solution probe;

measuring temperature: room temperature (25 ℃);

sample rotation speed: 20 kHz;

the determination method comprises the following steps: an inverse gated decoupling method;

²⁹the flip angle of Si: (ii) 90;

²⁹si 90 ° pulse width: 8.0μs；

Repetition time: 5 s;

cumulative number of times: 9200 times;

observation width: 30 kHz.

<²⁹Si-NMR sample preparation method>

In order to shorten the relaxing time, Fe (acac) was added as a relaxing agent₃And (4) carrying out measurement.

Polysilsesquioxane concentration: 15 percent;

Fe(acac)₃concentration: 0.6 percent;

and (3) determination of a solvent: acetone;

internal standard: TMS.

< analysis of waveform processing >

For each peak of the spectrum after fourier transform, a chemical shift is obtained from the position of the peak top, and integrated.

[ measurement of refractive index ]

The curable composition was discharged onto a horizontal surface, and the refractive index (nD) was measured by pressing the measurement surface of a PEN refractometer (PEN-RI, manufactured by ATAGO) at 25 ℃.

[ evaluation of curability ]

The shear stress was measured at a test initiation temperature of 80 ℃, a temperature rise rate of 5 ℃/min, a shear strain of 1%, and a frequency of 1Hz using a 20mm parallel plate using a rheometer (MCR 302, manufactured by Anton Paar Co.). The curing temperature was set at a temperature at which the shear stress reached 2000 Pa.

[ evaluation of viscosity ]

The shear rate was measured at 25 ℃ for 2s using a laminar plate having a radius of 50mm and a cone angle of 0.5 ℃ using a rheometer (MCR 301, manufactured by Anton Paar Co., Ltd.)^-1And a shear rate of 200s^-1Viscosity of (2). The thixotropic index (shear rate 2 s) was determined from the obtained measurement values^-1Viscosity/shear rate of 200s^-1Viscosity of (d).

[ measurement of adhesive Strength ]

In a square 2mm on a side (4 mm in area)²) The silicon chip mirror coating curable composition was adjusted to a thickness of about 2μm, the coated surface was placed on an adherend (silver-plated copper plate) and press-bonded. Thereafter, the resultant was heat-treated at 170 ℃ for 2 hours to cure the resultant to obtain an adherend with a test piece. The adherend with the test piece was left on a measuring table of an adhesion tester (series 4000, manufactured by Dage corporation) heated to a predetermined temperature (23 ℃ C., 100 ℃ C.) in advance for 30 seconds from the adherend 100μm high position at speed 200μm/s stress was applied to the adhesive surface in the horizontal direction (shear direction), and the adhesive strength (N/4 mm) between the test piece and the adherend at 23 ℃ and 100 ℃ was measured²)。

[ evaluation of crack resistance ]

In a square with a side length of 0.5mm (area of 0.25 mm)²) The curable composition for mirror coating of a glass chip of (2) is adjusted to a thickness of about 2μm, the coated surface was placed on an adherend (silver-plated copper plate) and press-bonded. Thereafter, the resultant was cured by heat treatment at 170 ℃ for 2 hours to obtain an adherend with a test piece. The resin portion (round portion) protruding (protruding) from the glass chip was observed by using a digital microscope (VHX-1000, manufactured by Keyence), the number of samples having cracks was counted, and the rate of occurrence of cracks of 0% or more and less than 25% was evaluated as "a",25% or more and less than 50% was evaluated as "B", 50% or more and 100% was evaluated as "C".

[ evaluation of Peel resistance ]

An LED lead frame (5050D/G PKG LEADFRAME, made by Enomoto corporation) was coated with 0.4mmϕLeft and right curable compositions were laminated, and then a square having a side of 0.5mm (area of 0.25 mm) was pressed²) The sapphire chip of (1). Thereafter, the resultant was cured by heat treatment at 170 ℃ for 2 hours, and then a sealing material (LPS-3419, manufactured by shin-Etsu chemical Co., Ltd.) was poured into the cup, heated at 120 ℃ for 1 hour, and further heated at 150 ℃ for 1 hour to obtain a test piece.

The test piece was exposed to an atmosphere of 85 ℃ and 85% RH for 168 hours, and then treated in an IR reflow furnace (reflow furnace: product name "WL-15-20 DNX" manufactured by phase Mount technology) preheated to 160 ℃ and heated at a maximum temperature of 260 ℃ for 1 minute. Thereafter, 500 cycles were performed using a thermal cycler with a test of 30 minutes each at-40 ℃ and +100 ℃ as 1 cycle. After that, an operation of removing the sealing material was performed, and whether or not the elements were peeled off together at this time was examined. This test was performed 100 times for each curable composition.

The number of times the elements were peeled together was evaluated as "a" if the peeling occurrence rate was 25% or less, "B" if it was more than 25% and 50% or less, and "C" if it was more than 50%.

[ Table 1]

The following results are shown in Table 1.

With respect to the curable polysilsesquioxane compounds (1) to (5) obtained in examples 1 to 5,²⁹as a result of Si-NMR measurement, it was found that: the value of Z2 is in the range of 20-40%. The mass average molecular weights of the curable polysilsesquioxane compounds (1) to (5) are all in the range of 4000 to 11000.

The curable compositions (1) to (5) containing these curable polysilsesquioxane compounds have a low refractive index (nD) and are sufficiently cured at a relatively low temperature.

In addition, the cured products of the curable compositions (1) to (5) have high adhesive strength.

On the other hand, in comparative examples 1 to 3, the curable polysilsesquioxane compounds [ curable polysilsesquioxane compounds (6) to (8) ] of examples 8 to 10 of patent document 4 were used, respectively.

In the examples of patent document 4, in order to compensate for the low reactivity of the silane compound having a fluoroalkyl group, a large amount of an acid catalyst is used. However, only curable polysilsesquioxane compounds having a small value of Z2 were obtained in this method. Further, as the charge amount of 3,3, 3-trifluoropropyltrimethoxysilane was increased, the mass average molecular weight of the curable polysilsesquioxane compound was decreased.

For these reasons, the curable compositions (6) to (8) of comparative examples 1 to 3 are inferior to the curable compositions (1) to (5) of examples 1 to 5 in curability or adhesive strength of cured products.

The curable polysilsesquioxane compound (9) obtained in comparative example 4 did not have a repeating unit derived from 3,3, 3-trifluoropropyltrimethoxysilane. Therefore, the refractive index (nD) of the curable composition (9) has a large value.

Further, the curable polysilsesquioxane compound (9) has a small value of Z2, and thus the curable composition (9) has insufficient curability.

The molecular weight of the curable polysilsesquioxane compound (10) obtained in comparative example 5 was too large. As a result, the curable composition (10) was inferior in curability and adhesive strength of the cured product to those of the curable compositions (1) to (5) of examples 1 to 5.