JP7724677B2 - Silane compound, siloxane compound, production method thereof, and curable resin composition - Google Patents

Description

The present invention relates to silane compounds, siloxane compounds, methods for producing them, and curable resin compositions. More specifically, the present invention relates to alkali-soluble and heat-resistant silane compounds, siloxane compounds, methods for producing them, and curable resin compositions.

Siloxane compounds are compounds that contain Si-O bonds (siloxane bonds) and have traditionally been widely used as raw materials for various industrial products. Recently, they have been used in a variety of applications due to their heat resistance and other properties resulting from siloxane bonds.

Various siloxane compounds have been widely known. For example, Patent Document 1 describes an alkali-soluble resin containing a hydrolyzable silane, its hydrolysate, its hydrolyzed condensate, or a mixture thereof, which contains an organic group having at least one amide group and at least one carboxy group and exhibits high solubility in a developer.

Furthermore, Patent Document 2 describes a negative-type photosensitive resin composition containing an alkali-soluble resin having a carboxy group. It also describes that the alkali-soluble resin is an acrylic resin obtained by reacting a polysiloxane having a carboxyl group and a radically polymerizable group and/or an acrylic resin having a carboxyl group with a mono-substituted epoxy compound having a radically polymerizable group, and therefore provides a cured film with excellent pattern processability, high hardness, high transparency, and excellent moisture and heat resistance upon UV curing and heat curing.

Furthermore, Patent Document 3 describes a silsesquioxane derivative that has an -NHCO- structure, has high heat resistance, good alkaline developability, and excellent coating film properties, and is used as a resist resin, etc.

JP 2009-286980 A JP 2012-88610 A JP 2014-118418 A

However, conventional alkali-soluble siloxane compounds still lack sufficient heat resistance. Therefore, there was a need to develop alkali-soluble, heat-resistant siloxane compounds, as well as silane compounds with excellent heat resistance for producing such siloxane compounds. Furthermore, in recent years, higher performance has been required in a variety of fields, including optics and electronics, and to meet this demand and enable application in a wide range of applications, even better heat resistance is required.

In light of the above-mentioned current situation, the present invention aims to provide silane compounds and siloxane compounds that are alkali-soluble and have excellent heat resistance, as well as a manufacturing method that has excellent synthetic stability and can efficiently produce these compounds.

In order to solve the above-mentioned problems, the inventors investigated various silane compounds and siloxane compounds. One method for introducing a carboxyl group to make a compound alkali-soluble involves reacting an amine with succinic anhydride or the like to form an amide bond, thereby introducing the carboxyl group. They discovered that forming an imide bond in this case can significantly improve the heat resistance of the compound into which the carboxyl group has been introduced. Furthermore, they discovered that when producing such a siloxane compound, a siloxane compound having an organic group with an imide bond and a carboxyl group can be synthesized stably and efficiently by reacting an amino-group-containing silane compound with a compound containing an acid anhydride group and a carboxyl group to obtain an imide-bond-containing silane compound, and then condensing the reaction raw materials containing the silane compound. This discovery led to the completion of the present invention.

In other words, the present invention is an imide bond-containing silane compound characterized by having an organic group having an imide bond and a carboxy group.

The present invention also relates to a siloxane compound characterized by having an organic group having an imide bond and a carboxy group.

The above siloxane compound preferably has an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms.

The above-mentioned siloxane compound preferably has an organic group having at least one group selected from the group consisting of a (meth)acryloyl group, a vinyl group, and an epoxy group.

The present invention also relates to a curable resin composition comprising the above-mentioned siloxane compound and a photopolymerization initiator and/or an acid generator.

The above-mentioned curable resin composition preferably contains a polymerizable compound.

The above-mentioned curable resin composition is preferably a negative-type photosensitive resin composition.

The present invention also relates to a method for producing an imide bond-containing silane compound, which comprises the step of reacting an amino group-containing silane compound with a compound having an acid anhydride group and a carboxy group.

The present invention also relates to a method for producing a siloxane compound, comprising the steps of reacting an amino group-containing silane compound with a compound having an acid anhydride group and a carboxy group, and condensing the reaction raw materials, including the imide bond-containing silane compound produced in the reaction step.

The present invention provides silane compounds and siloxane compounds that are alkali-soluble and have excellent heat resistance, and enables stable and efficient production of the above silane compounds and siloxane compounds.

The present invention will be described in detail below.
It should be noted that a combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

1. Imide Bond-Containing Silane Compound The present invention relates to an imide bond-containing silane compound characterized by having an imide bond and an organic group having a carboxy group.
The silane compound of the present invention is alkali-soluble and has excellent heat resistance. Furthermore, by using the silane compound of the present invention, it is possible to stably and efficiently produce a siloxane compound that is alkali-soluble and has excellent heat resistance.
The silane compound of the present invention and the siloxane compound synthesized using the silane compound are also excellent in heat resistance, presumably because they are composed of heat-stable Si—O bonds and imide bonds.

The organic group having an imide bond and a carboxy group is preferably a group represented by the following general formula (1):

(wherein ^R1 and ^R2 may be the same or different and represent an organic group which may have a carboxy group, and at least one of ^R1 and ^R2 is an organic group which has a carboxy group. ^R1 and ^R2 may be bonded to each other to form a ring structure. ^R3 represents a direct bond or a divalent organic group. * represents a bonding site of the organic group.)

The organic groups represented by ^R1 and ^R2 include hydrocarbon groups, carboxy groups, and groups consisting of a combination of hydrocarbon groups, carboxy groups, -O-, -CO-, -COO-, -NH-, or -SO ₂ -, and preferably hydrocarbon groups, carboxy groups, or groups consisting of a combination of a hydrocarbon group and a carboxy group.

The hydrocarbon groups represented by R ¹ and R ² include linear or cyclic saturated or unsaturated hydrocarbon groups, or combinations thereof.
The hydrocarbon group may be an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, with aromatic hydrocarbon groups being preferred because of their thermal stability.

Examples of the aliphatic hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a sec-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a hexyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 2,2-dimethylbutyl group, a 2,3-dimethylbutyl group, a heptyl group, a 2-methylhexyl group, a 3-methylhexyl group, a 2,2-dimethylpentyl group, a 2,3-dimethylpentyl group, a 2,4-dimethylpentyl group, a 3-ethylpentyl group, a 2,2,3-trimethylbutyl group, an octyl group, a methylheptyl group, a dimethylhexyl group, a 2-ethylhexyl group, a 3-ethylhexyl group, a trimethylpentyl group, a 3-ethyl-2-methylpentyl group, a 2-ethyl-3-methylpentyl group, and a 2,2,3,3-tetramethylbutyl group. alkyl groups such as a methyl group, a nonyl group, a methyloctyl group, a 3,7-dimethyloctyl group, a dimethylheptyl group, a 3-ethylheptyl group, a 4-ethylheptyl group, a trimethylhexyl group, a 3,3-diethylpentyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, and an eicosyl group; Examples include alkenyl groups such as n-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 1-pentenyl, 2-pentenyl, 2-methyl-1-butenyl, 2-methyl-2-butenyl, 3-methyl-1-butenyl, 1-hexenyl, 2-hexenyl, 1-heptenyl, 2-heptenyl, 1-octenyl, and 2-octenyl; or divalent groups thereof.

Examples of the alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclononyl group, a cyclodecyl group, a dicyclopentanyl group, a norbornyl group, an adamantyl group, or divalent groups thereof.

Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, a biphenyl group, a methoxyphenyl group, a trichlorophenyl group, an ethylphenyl group, a tolyl group, a xylyl group, a benzyl group, or divalent groups thereof.

^R1 and ^R2 may be bonded to each other to form a ring structure. Examples of the ring structure include an imide ring, a condensed ring of an imide ring and a hydrocarbon ring, and the like, which may have a substituent.
The imide ring is a ring in which an imide bond forms a ring structure.
The imide ring is preferably a 5- or 6-membered ring, and more preferably a 5-membered ring.

Examples of the hydrocarbon ring include aliphatic hydrocarbon rings such as a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring; and aromatic hydrocarbon rings such as a benzene ring and a naphthalene ring.
The hydrocarbon ring is preferably a 3- to 6-membered ring, more preferably a 4- to 6-membered ring, and even more preferably a 5- or 6-membered ring.
The imide ring and hydrocarbon ring may have a substituent.
Among these, the ring structure is preferably a condensed ring of an imide ring and a hydrocarbon ring, and more preferably a condensed ring of an imide ring and an aromatic hydrocarbon ring.

The hydrocarbon groups represented by R ¹ and R ² preferably have 1 to 15 carbon atoms, more preferably 3 to 13 carbon atoms, and even more preferably 5 to 11 carbon atoms.

At least one of R ¹ and R ² is an organic group having a carboxy group.
When R ¹ and R ² are linked to each other to form a ring structure, the ring structure preferably has at least one carboxy group or a group containing a carboxy group as a substituent.
The organic group may have a carboxy group at any position.
The organic group may have one or more carboxy groups, but preferably has one or two carboxy groups.

^R3 represents a direct bond or a divalent organic group. Examples of the divalent organic group include the above-mentioned divalent hydrocarbon groups, -CO-, -COO-, -NH-, -SO ₂ -, and divalent groups combining these, preferably a divalent hydrocarbon group or a divalent group combining a divalent hydrocarbon group and -NH-, more preferably a divalent hydrocarbon group, even more preferably a divalent aliphatic hydrocarbon group, and even more preferably an alkylene group.
A preferred example of the divalent group formed by combining the above divalent hydrocarbon group with —NH— is —R′—NH—R″— (wherein R′ and R″ are the same or different and each represent a divalent hydrocarbon group).
The divalent hydrocarbon groups represented by R' and R'' are preferably divalent aliphatic hydrocarbon groups, and more preferably alkylene groups.
The divalent hydrocarbon groups represented by R' and R'' preferably have 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms.

The divalent organic group represented by ^R3 preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 5 carbon atoms.

In the general formula (1), * represents the bonding site of the organic group.
The organic group is preferably bonded to a silicon atom.

The imide bond-containing silane compound is preferably a compound represented by the following general formula (2):

R ⁴ _a R ⁵ _b SiR ⁶ _[4-(a+b)] (2)
(In the formula, ^R4 represents an organic group having an imide bond and a carboxy group. ^R5 represents an organic group other than an organic group having an imide bond and a carboxy group. ^R6 represents an alkoxy group, an acyloxy group, a halogen atom, a hydroxyl group, or a hydrogen atom. a represents the number 1 or 2, and b represents the number 0 or 1.)

The organic group having an imide bond and a carboxy group represented by ^R4 is preferably a group represented by the above general formula (1). When there are two ^R4s , the organic groups represented by ^R4s may be the same or different.

The organic group other than the organic group having an imide bond and a carboxy group represented by ^R5 above is more preferably an organic group not containing an imide bond, and specific examples include a hydrocarbon group, an epoxy group, a (meth)acryloyl group, a vinyl group, an amino group, a phosphate group, a carboxy group, an amide group, a nitro group, an acyl group, a sulfone group, or a group combining these.
Examples of the hydrocarbon group include the same groups as those mentioned above.
The hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 5 carbon atoms.
Among these, the organic group other than the organic group having an imide bond and a carboxy group represented by ^R5 above is preferably a hydrocarbon group or a group in which a hydrocarbon group is combined with an epoxy group, a (meth)acryloyl group, a vinyl group, an amino group, a phosphate group, a carboxy group, an amide group, a nitro group, an acyl group, or a sulfone group, more preferably a hydrocarbon group, still more preferably an aliphatic hydrocarbon group, and particularly preferably an alkyl group.

The alkoxy group represented by ^R6 is a group represented by "-OR'", and the "R'" is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably an alkyl group having 1 to 2 carbon atoms.

The acyloxy group represented by ^R6 is a group represented by "-O-CO-R"", and "R" is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms.

Among these, ^R6 is preferably an alkoxy group or an acyloxy group, and more preferably an alkoxy group.

In the above general formula (2), a represents the number 1 or 2, and b represents the number 0 or 1. Preferably, a is 1 and b is 0.

Specific preferred examples of the imide bond-containing silane compound include the following compounds:

<Method of producing imide bond-containing silane compound>
The method for producing the imide bond-containing silane compound is not particularly limited as long as it can produce the imide bond-containing silane compound, and any method may be used. Among these, a method comprising a step of reacting an amino group-containing silane compound with a compound having an acid anhydride group and a carboxy group is preferred, as it allows for stable and efficient production. By reacting the amino group-containing silane compound with a compound having an acid anhydride group and a carboxy group, the amino group and the acid anhydride group react to easily form an imide bond, thereby allowing the silane compound to be produced efficiently. Such a method for producing an imide bond-containing silane compound, comprising a step of reacting an amino group-containing silane compound with a compound having an acid anhydride group and a carboxy group, also constitutes one aspect of the present invention.
From the viewpoint of reactivity, the amino group is preferably a primary amino group.

The amino group-containing silane compound is preferably a compound represented by the following general formula (3):
(H ₂ NR ³ -) _a R ⁵ _b SiR ⁶ _[4-(a+b)] (3)
(In the formula, ^R3 is the same as ^R3 in the above general formula (1). ^R5 and ^R6 are the same as ^R5 and ^R6 in the above general formula (2). a represents the number 1 or 2. b represents the number 0 or 1.)

Specific examples of the amino group-containing silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2(aminoethyl)-3-aminopropylmethyldiethoxysilane, and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane. Among these, 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane are preferred due to their high synthetic stability.

Examples of compounds having an acid anhydride group (-CO-O-CO-) and a carboxy group include trimellitic anhydride and other acid anhydrides having a carboxyl group as a substituent.

The reaction of the amino group-containing silane compound with the compound having an acid anhydride group and a carboxy group can be carried out by mixing these compounds and heating them.
The mixing ratio of the amino group-containing silane compound to the compound having an acid anhydride group and a carboxy group is preferably 85/15 to 15/85 by molar ratio, more preferably 70/30 to 30/70, and even more preferably 45/55 to 55/45.

The above compounds are preferably mixed in a solvent. Examples of solvents that can be used include 1-methyl-2-pyrrolidone (NMP), methanol, ethanol, propanol, isopropanol, n-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, n-propyl acetate, ethyl lactate, methyl ethyl ketone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether, cyclohexanone, 1-methoxy-2-propanol, diethylene glycol dimethyl ether, 1,2-dimethoxyethane, and ethyl diglycol acetate. The above solvents may be used alone or in combination.

The heating may be carried out in air or in a nitrogen atmosphere, but is preferably carried out in a nitrogen atmosphere, as this can prevent discoloration due to oxidation.

The heating temperature is preferably 45° C. or higher, more preferably 50° C. or higher, and even more preferably 60° C. or higher. From the viewpoint of suppressing hydrolysis of the alkoxysilane, the upper limit of the heating temperature is preferably 200° C. or lower, and more preferably 160° C. or lower.
The heating time is not particularly limited, but is, for example, 1 to 10 hours, preferably 1 to 8 hours, and more preferably 1 to 6 hours.

In the above reaction process, commonly used additives such as amines, phosphoric acid, and phosphate esters may also be used.

The method for producing the imide bond-containing silane compound may include other steps in addition to the steps described above. Examples of such other steps include a drying step, a purification step, a dilution step, and a concentration step. These steps can be carried out by known methods.

2. Siloxane Compound The siloxane compound of the present invention is a siloxane compound characterized by having an organic group having an imide bond and a carboxy group.
Examples of the organic group having an imide bond and a carboxy group include the same groups as the "organic group having an imide bond and a carboxy group" in the "silane compound containing an imide bond" described above.

As described above, the siloxane compound of the present invention has a siloxane bond (Si-O bond) and the aforementioned imide bond and organic group having a carboxy group, and is therefore believed to be alkali-soluble and have excellent heat resistance.

The siloxane compound preferably has an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms. By further having these groups, heat resistance can be further improved.
The siloxane compound preferably has an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and more preferably has an aryl group having 6 to 10 carbon atoms.

The above-mentioned siloxane compound preferably has an organic group having at least one group selected from the group consisting of a (meth)acryloyl group, a vinyl group, and an epoxy group. The inclusion of these groups improves the curability of the siloxane compound, and can improve the heat resistance of the cured product as well as solvent resistance, adhesion, and other properties.

The organic group having at least one group selected from the group consisting of a (meth)acryloyl group, a vinyl group, and an epoxy group includes a (meth)acryloyl group, a vinyl group, an epoxy group, or a group having a (meth)acryloyl group, a vinyl group, or an epoxy group, preferably a divalent hydrocarbon group having a (meth)acryloyl group, a vinyl group, or an epoxy group, more preferably a divalent aliphatic hydrocarbon group having a (meth)acryloyl group, a vinyl group, or an epoxy group.

The siloxane compound has a siloxane bond and is represented by the following average composition formula (4):
X _a Y _b Z _c SiO _d (4)
(in the formula, X may be the same or different and represent an organic group having an imide bond and a carboxy group; Y and Z may be the same or different and represent a hydrogen atom, a hydroxyl group, a halogen atom, or an organic group other than the organic group having an imide bond and a carboxy group; a is a non-zero number of 3 or less; b and c may be the same or different and represent 0 or a number less than 3; d is a non-zero number less than 2, and a+b+c+2d=4).

The siloxane skeleton (main skeleton essentially comprising siloxane bonds) of the siloxane compound can also be expressed as ( _SiOm ) _n . The structures other than ( _SiOm ) _n in the siloxane compound are X, Y, and Z, which are bonded to silicon atoms in the main chain skeleton.
The siloxane compound is also preferably a polysilsesquioxane.

The siloxane skeleton is preferably, for example, a chain (linear or branched), ladder, network, cyclic, cage, cubic, etc. Among these, from the viewpoint of easily exhibiting heat resistance even with a small amount of siloxane compound, a ladder, network, or cage structure is preferred, and a ladder or cage structure is more preferred. Note that the cage structure also includes an incomplete cage structure.
X, Y, and Z may or may not be included in the repeating unit in the form of a "chain." For example, it is sufficient that one or more Xs are included as side chains in one molecule.

In the above (SiO _m ) _n , n represents the degree of polymerization. The degree of polymerization represents the degree of polymerization of the main chain skeleton, but the number of the organic groups having an imide bond and a carboxy group does not necessarily need to be n. That is, one organic group having an imide bond and a carboxy group does not necessarily need to be present in one unit of (SiO _m ) _n . Furthermore, it is sufficient that one or more organic groups having an imide bond and a carboxy group are contained in one molecule, but when multiple organic groups are contained, two or more organic groups having an imide bond and a carboxy group may be bonded to one silicon atom.

In the main chain skeleton (SiO _m ) _n , m is preferably a number of 1 or more and less than 2, more preferably 1.5 to 1.8. n represents the degree of polymerization, and is preferably 1 to 5,000, more preferably 1 to 2,000, even more preferably 1 to 1,000, and particularly preferably 1 to 200.

In the above siloxane compound, the proportion of the siloxane skeleton is preferably 10 to 80 mass% of 100 parts by mass of the siloxane compound, more preferably 17 to 70 mass%, and even more preferably 20 to 50 mass%.

In the average composition formula (4), X represents an organic group having an imide bond and a carboxy group. Examples of the organic group having an imide bond and a carboxy group represented by X include the same groups as the organic group having an imide bond and a carboxy group represented by ^R4 described above.

The coefficient of X is a non-zero number of 3 or less. That is, it is a number that satisfies 0<a≦3. a is preferably 0.2 or more, more preferably 0.5 or more, even more preferably 0.7 or more, and particularly preferably 0.8 or more. It is also preferably 2 or less, more preferably 1.5 or less, and even more preferably 1.

Y and Z are the same or different and represent a hydrogen atom, a hydroxyl group, a halogen atom, or an organic group other than the organic group having an imide bond and a carboxy group. Examples of the organic group other than the organic group having an imide bond and a carboxy group include the same groups as the organic group other than the organic group having an imide bond and a carboxy group represented by ^R5 . Among these, the organic group is preferably a hydrocarbon group, an epoxy group, a (meth)acryloyl group, a vinyl group, or a group formed by combining these, and more preferably an alkyl group, an aryl group, an epoxy group, a (meth)acryloyl group, a vinyl group, or a group formed by combining these.

Y is preferably a hydrocarbon group, more preferably an alkyl group or an aryl group, and even more preferably an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms.

Furthermore, Z is preferably an organic group having at least one group selected from the group consisting of a (meth)acryloyl group, a vinyl group, and an epoxy group.

The coefficient b of Y and the coefficient Z are each 0 or a number less than 3. That is, they are numbers that satisfy 0≦b<3 and 0≦c<3. The coefficient d of the oxygen atom O is a non-zero number less than 2. That is, it is a number that satisfies 0<d<2. These coefficients are not particularly limited as long as they are set so that the coefficient a of X falls within the preferred range described above.

Among these, the siloxane compound is preferably a silsesquioxane compound having a structure represented by the following general formula (5):

(In the formula, ^R7 represents an organic group having an imide bond and a carboxy group.)

Examples of the organic group having an imide bond and a carboxy group represented by ^R7 include the above-mentioned organic groups having an imide bond and a carboxy group.

Furthermore, the above-mentioned siloxane compound is preferably a silsesquioxane compound further having a structure represented by the following general formula (6):

(In the formula, ^R8 represents an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms.)

The alkyl group having 1 to 12 carbon atoms and the aryl group having 6 to 12 carbon atoms represented by R ⁸ are preferably the same groups as those described above.

More preferably, the above siloxane compound is a silsesquioxane compound further having a structure represented by the following general formula (7):

(In the formula, ^R9 represents an organic group having at least one group selected from the group consisting of a (meth)acryloyl group, a vinyl group, and an epoxy group.)

The organic group represented by R ⁹ and having at least one group selected from the group consisting of a (meth)acryloyl group, a vinyl group, and an epoxy group is preferably the same group as those described above.

The structures represented by the above general formulas (5) to (7) represent repeating units in the above siloxane compound (silsesquioxane compound).

When the siloxane compound has a structure represented by the general formula (5) or (6), it exhibits excellent heat resistance and solvent resistance. Therefore, the composition ratio of each structure, where p and q are the molar ratios of the structures represented by the general formula (5) or (6), respectively, is preferably (5-80)/(95-20), more preferably (10-70)/(90-30), and even more preferably (15-50)/(85-50).

When the siloxane compound has a structure represented by the general formula (5), (6), or (7), it exhibits superior heat resistance. Therefore, the composition ratio of each structure is preferably (5-80)/(90-5)/(1-90), more preferably (10-70)/(80-10)/(5-70), and even more preferably (15-50)/(70-15)/(10-50), where p, q, and r are the molar ratios of the structures represented by the formulas (5), (6), and (7), respectively. In this case, p+q+r=100 mol%.

The weight average molecular weight of the siloxane compound is preferably 500 or more, more preferably 800 or more, and even more preferably 1000 or more, and is preferably 50000 or less, more preferably 30000 or less, and even more preferably 10000 or less.
The weight average molecular weight can be determined by GPC (gel permeation chromatography) measurement under the measurement conditions described below.

The acid value of the siloxane compound is preferably 30 mgKOH/g or more, more preferably 40 mgKOH/g or more, and even more preferably 50 mgKOH/g or more, and is preferably 500 mgKOH/g or less, more preferably 300 mgKOH/g or less, even more preferably 200 mgKOH/g or less, and even more preferably 100 mgKOH/g or less.
The acid value is a value obtained by measurement by neutralization titration using a potassium hydroxide (KOH) solution, and is an acid value per 1 g of solid content of the compound.

<Method for producing siloxane compound>
The method for producing the siloxane compound of the present invention is not particularly limited, and known methods can be used, but a method of preparing the above-mentioned imide bond-containing silane compound and condensing the obtained imide bond-containing silane compound is preferred because it allows stable and efficient production. That is, the method for producing the siloxane compound of the present invention preferably includes a step of reacting an amino group-containing silane compound with a compound having an acid anhydride group and a carboxyl group, and a step of condensing the reaction raw material containing the imide bond-containing silane compound produced in the above reaction step. Such a method for producing a siloxane compound also constitutes one aspect of the present invention.

The method for producing a siloxane compound of the present invention first includes a step of reacting an amino group-containing silane compound with a compound having an acid anhydride group and a carboxyl group. The reaction step is preferably the same as the reaction step of an amino group-containing silane compound with a compound having an acid anhydride group and a carboxyl group in the above-mentioned "method for producing an imide bond-containing silane compound."

The method for producing a siloxane compound of the present invention then includes a step of condensing the reaction raw materials including the imide bond-containing silane compound produced in the above reaction step.
The imide bond-containing silane compound used as the reaction raw material may be the same as those mentioned above.
In this specification, the term "reaction raw materials" refers to the total amount of silane compounds used in the production of a siloxane compound.

The reaction raw materials may contain other silane compounds in addition to the imide bond-containing silane compound (silane compound (A)). Examples of the other silane compounds include a silane compound (silane compound (B)) having an organic group other than the organic group having an imide bond and a carboxyl group.
Examples of the silane compound (silane compound (B)) having an organic group other than the organic group having an imide bond and a carboxyl group include a silane compound having an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and a silane compound having an organic group having at least one group selected from the group consisting of a (meth)acryloyl group, a vinyl group, and an epoxy group.

Specific examples of silane compounds having an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms include alkylalkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, and propyltriethoxysilane; and arylalkoxysilanes such as phenyltrimethoxysilane and phenyltriethoxysilane.

Specific examples of silane compounds having an organic group containing at least one group selected from the group consisting of (meth)acryloyl groups, vinyl groups, and epoxy groups include vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane.

The content ratio of the imide bond-containing silane compound (A) and the other silane compound (B) contained in the reaction raw materials can be appropriately set depending on the composition ratio of the target siloxane compound.
For example, the content of the imide bond-containing silane compound (A) is preferably 1 to 90 mass%, more preferably 5 to 70 mass%, and even more preferably 10 to 50 mass%, relative to 100 mass% of the reaction raw materials.

The content of the silane compound having an alkyl group with 1 to 12 carbon atoms or an aryl group with 6 to 12 carbon atoms is preferably 1 to 90 mass%, more preferably 5 to 70 mass%, and even more preferably 10 to 50 mass%, based on 100 mass% of the reaction raw materials.

The content of the silane compound having an organic group containing at least one group selected from the group consisting of a (meth)acryloyl group, a vinyl group, and an epoxy group is 100% by mass of the reaction raw materials, preferably 1 to 90% by mass, more preferably 5 to 70% by mass, and even more preferably 10 to 50% by mass.

The step of condensing the above-mentioned reaction raw materials is preferably a step of subjecting the alkoxysilyl groups in the silane compound reaction raw materials to a hydrolysis and condensation reaction.

In the condensation step, the reactants are preferably heated in the presence of water.
The amount of water used is preferably 50 to 200 moles, more preferably 70 to 150 moles, and even more preferably 90 to 120 moles, per 100 moles of the total amount of the silane compounds as reaction raw materials.

The reaction temperature is preferably 40 to 200°C, more preferably 50 to 180°C, and even more preferably 60 to 160°C.
The reaction temperature is preferably 30 to 100°C, preferably 40 to 80°C initially, and then increased to 50 to 180°C, preferably 60 to 160°C.
The reaction time may be appropriately determined depending on the reaction temperature and reaction composition, but is usually 1 to 10 hours, preferably 2 to 5 hours.

The above condensation step may be carried out under normal pressure, elevated pressure, or reduced pressure, but it is preferable to carry it out at or below normal pressure in order to facilitate the reaction.

The above condensation step is preferably carried out by first producing the imide bond-containing silane compound in the previous step, then cooling it to room temperature, such as about 20 to 40°C, adding water, and heating it to the above reaction temperature.

The reaction is preferably carried out in the presence of a solvent. Examples of the solvent include 1-methyl-2-pyrrolidone, methanol, ethanol, propanol, isopropanol, n-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, n-propyl acetate, ethyl lactate, methyl ethyl ketone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether, cyclohexanone, 1-methoxy-2-propanol, diethylene glycol dimethyl ether, 1,2-dimethoxyethane, and ethyl diglycol acetate. The solvents may be used alone or in combination.
The amount of the solvent used is such that the total concentration (mass %) of the reaction raw materials is 20 to 70%, preferably 25 to 50%.

A catalyst may be used in the above reaction. There are no particular limitations on the catalyst that can be used, and any known catalyst commonly used in condensation reactions of silane compounds can be used. Specific examples include metal chelate compounds, organic acids, inorganic acids, organic bases, and inorganic bases.

Examples of the above metal chelate compounds include triethoxy mono(acetylacetonate)titanium, tri-n-propoxy mono(acetylacetonate)titanium, tri-isopropoxy mono(acetylacetonate)titanium, tri-n-butoxy mono(acetylacetonate)titanium, tri-sec-butoxy mono(acetylacetonate)titanium, tri-t-butoxy mono(acetylacetonate)titanium, diethoxy bis(acetylacetonate)titanium, di-n-propoxy bis(acetylacetonate)titanium, di-isopropoxy bis(acetylacetonate)titanium, di-n-butoxy bis(acetylacetonate)titanium, and di-sec-butoxy bis(acetylacetonate)titanium. , di-t-butoxy bis(acetylacetonate)titanium, monoethoxy tris(acetylacetonate)titanium, mono-n-propoxy tris(acetylacetonate)titanium, mono-isopropoxy tris(acetylacetonate)titanium, mono-n-butoxy tris(acetylacetonate)titanium, mono-sec-butoxy tris(acetylacetonate)titanium, mono-t-butoxy tris(acetylacetonate)titanium, tetrakis(acetylacetonate)titanium, triethoxy mono(ethylacetoacetate)titanium, tri-n-propoxy mono(ethylacetoacetate)titanium, tri-isopropoxy mono(ethylacetoacetate)titanium, tri-n-butoxy mono(ethylacetoacetate) titanium, tri-sec-butoxy mono(ethylacetoacetate), tri-t-butoxy mono(ethylacetoacetate), diethoxy bis(ethylacetoacetate), titanium, di-n-propoxy bis(ethylacetoacetate), titanium, di-isopropoxy bis(ethylacetoacetate), titanium, di-n-butoxy bis(ethylacetoacetate), titanium, di-sec-butoxy bis(ethylacetoacetate), titanium, di-t-butoxy bis(ethylacetoacetate), titanium, monoethoxy tris(ethylacetoacetate), mono-n-propoxy tris(ethylacetoacetate), titanium, mono-isopropoxy tris(ethylacetoacetate) titanium chelate compounds such as mono-n-butoxy tris(ethylacetoacetate) titanium, mono-sec-butoxy tris(ethylacetoacetate) titanium, mono-t-butoxy tris(ethylacetoacetate) titanium, tetrakis(ethylacetoacetate) titanium, mono(acetylacetonato)tris(ethylacetoacetate) titanium, bis(acetylacetonato)bis(ethylacetoacetate) titanium, tris(acetylacetonato)mono(ethylacetoacetate) titanium; triethoxy mono(acetylacetonato)zirconium, tri-n-propoxy mono(acetylacetonato)zirconium, tri-isopropoxy mono(acetylacetonato)zirconium zirconium, tri-n-butoxy mono(acetylacetonate)zirconium, tri-sec-butoxy mono(acetylacetonate)zirconium, tri-t-butoxy mono(acetylacetonate)zirconium, diethoxy bis(acetylacetonate)zirconium, di-n-propoxy bis(acetylacetonate)zirconium, di-isopropoxy bis(acetylacetonate)zirconium, di-n-butoxy bis(acetylacetonate)zirconium, di-sec-butoxy bis(acetylacetonate)zirconium, di-t-butoxy bis(acetylacetonate)zirconium, monoethoxy tris(acetylacetonate)zirconium, mono-n-propoxy tris (acetylacetonate)zirconium, mono-isopropoxy tris(acetylacetonate)zirconium, mono-n-butoxy tris(acetylacetonate)zirconium, mono-sec-butoxy tris(acetylacetonate)zirconium, mono-t-butoxy tris(acetylacetonate)zirconium, tetrakis(acetylacetonate)zirconium, triethoxy mono(ethylacetoacetate)zirconium, tri-n-propoxy mono(ethylacetoacetate)zirconium, tri-isopropoxy mono(ethylacetoacetate)zirconium, tri-n-butoxy mono(ethylacetoacetate)zirconium, tri-sec-butoxy mono(ethylacetoacetate) mono-t-butoxy tris(ethylacetoacetate) zirconium, tri-t-butoxy mono(ethylacetoacetate) zirconium, diethoxy bis(ethylacetoacetate) zirconium, di-n-propoxy bis(ethylacetoacetate) zirconium, di-isopropoxy bis(ethylacetoacetate) zirconium, di-n-butoxy bis(ethylacetoacetate) zirconium, di-sec-butoxy bis(ethylacetoacetate) zirconium, di-t-butoxy bis(ethylacetoacetate) zirconium, monoethoxy tris(ethylacetoacetate) zirconium, mono-n-propoxy tris(ethylacetoacetate) zirconium, mono-isopropoxy tris(ethylacetoacetate) zirconium Zirconium chelate compounds such as mono-n-butoxy tris(ethylacetoacetate)zirconium, mono-sec-butoxy tris(ethylacetoacetate)zirconium, mono-t-butoxy tris(ethylacetoacetate)zirconium, tetrakis(ethylacetoacetate)zirconium, mono(acetylacetonato)tris(ethylacetoacetate)zirconium, bis(acetylacetonato)bis(ethylacetoacetate)zirconium, and tris(acetylacetonato)mono(ethylacetoacetate)zirconium; aluminum chelate compounds such as tris(acetylacetonato)aluminum and tris(ethylacetoacetate)aluminum; and the like.

Examples of the organic acid include acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic acid, methylmalonic acid, adipic acid, sebacic acid, gallic acid, butyric acid, mellitic acid, arachidonic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, linoleic acid, linolenic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, p-toluenesulfonic acid, benzenesulfonic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, formic acid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citric acid, and tartaric acid.
Examples of the inorganic acid include nitric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid.

Examples of the organic base include pyridine, pyrrole, piperazine, pyrrolidine, piperidine, picoline, trimethylamine, triethylamine, monoethanolamine, diethanolamine, dimethylmonoethanolamine, monomethyldiethanolamine, triethanolamine, diazabicyclooctane, diazabicyclononane, diazabicycloundecene, tetramethylammonium hydroxide, and 1,8-diazabicyclo[5,4,0]-7-undecene.

Examples of the inorganic base include ammonia, sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide, etc.

Among these, organic bases are preferred as the catalyst.
The above catalysts may be used alone or in combination of two or more.

The amount of the catalyst added is not particularly limited and may be any ordinary amount, for example, 0.01 to 10% by mass, preferably 0.1 to 5% by mass, relative to the silane compound used as the reaction raw material.

After the condensation step, it is preferable to distill off the generated solvent, such as water. The method for distilling off the solvent is not particularly limited, and may be a known method such as heating.

The method for producing the siloxane compound may include other steps in addition to those described above. These other steps include an aging step, a drying step, a purification step, a dilution step, and a concentration step. These steps can be carried out by known methods.

The condensation degree of the siloxane compound obtained by the above production method is preferably 20 to 60%, more preferably 30 to 50%. When the condensation degree of the siloxane compound is within the above range, it becomes easily soluble in an alkaline solvent and can be suitably used as an alkali-soluble resin.
The degree of condensation can be determined by the method described in the examples below.

3. Curable Resin Composition The present invention also relates to a curable resin composition containing the above-described siloxane compound and a photopolymerization initiator and/or an acid generator. The curable resin composition of the present invention contains the above-described siloxane compound and has excellent heat resistance.

In the curable resin composition, the content of the siloxane compound is preferably 5 to 90% by mass, more preferably 10 to 70% by mass, and even more preferably 20 to 50% by mass, relative to 100% by mass of the total solid content of the curable resin composition.
In this specification, the term "total amount of solids" refers to the total amount of components that form the cured product (excluding solvents and the like that volatilize during the formation of the cured product).

(Photopolymerization initiator)
The photopolymerization initiator used in the curable resin composition of the present invention is preferably a radically polymerizable photopolymerization initiator that generates polymerization-initiating radicals upon irradiation with active energy rays such as electromagnetic waves or electron beams.

Specific examples of the photopolymerization initiator include aminoketone compounds such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one ("IRGACURE907", manufactured by BASF), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1-one ("IRGACURE369", manufactured by BASF), and 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one ("IRGACURE379", manufactured by BASF); 2,2-dimethoxy-1,2-diphenylethan-1-one ("IRGACURE651", manufactured by BASF), and phenylglyoxylic acid methyl ester ("DAROCURE benzyl ketal compounds such as 1-hydroxy-cyclohexyl-phenyl-ketone ("IRGACURE184", manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propan-1-one ("DAROCUR1173", manufactured by BASF), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one ("IRGACURE2959", manufactured by BASF), 2-hydroxy-1- Hydroketone compounds such as {4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one ("IRGACURE 127", manufactured by BASF) and [1-hydroxy-cyclohexyl-phenyl-ketone + benzophenone] ("IRGACURE 500", manufactured by BASF); other alkylphenone compounds exemplified in paragraphs [0084] to [0086] of JP 2013-227485 A; 1,2-octyl benzophenone; Tanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxime) ("OXE01", manufactured by BASF), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) ("OXE02", manufactured by BASF), 1,2-octanedione, 1-[4-(phenylthio)-, 2-, (O-benzoyloxime)], ethanone ("OXE03", manufactured by BASF), 1-[9-ethyl-6- Examples of such compounds include oxime ester compounds such as [(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(O-acetyloxime) ("OXE04", manufactured by BASF), benzophenone compounds, benzoin compounds, thioxanthone compounds, halomethylated triazine compounds, halomethylated oxadiazole compounds, biimidazole compounds, titanocene compounds, benzoic acid ester compounds, acridine compounds, and phosphine oxide compounds. Of these, aminoketone compounds and oxime ester compounds are preferred.
The photopolymerization initiators may be used alone or in combination of two or more.

The content of the photopolymerization initiator is not particularly limited as long as it is within a range in which the effects of the present invention are exhibited, and may be set appropriately. For example, it is preferably 0.3 to 20% by mass, more preferably 0.5 to 10% by mass, and even more preferably 1 to 8% by mass, relative to 100% by mass of the total solids content of the curable resin composition of the present invention.

(Acid Generator)
The acid generator used in the curable resin composition of the present invention may be a photoacid generator or a thermal acid generator, but a thermal acid generator is preferred in that it can generate acid uniformly in the thickness direction of the coating film.
When the siloxane compound has an epoxy group, it is preferable to use an acid generator, since this improves the curability of the curable resin composition.

The photoacid generator is a compound that generates an acid when exposed to active energy rays such as radiation. Examples include strong acids such as toluenesulfonic acid or boron tetrafluoride; onium salts such as sulfonium salts, ammonium salts, phosphonium salts, iodonium salts, and selenium salts; iron-arene complexes; silanol-metal chelate complexes; sulfonic acid derivatives such as disulfones, disulfonyldiazomethanes, disulfonylmethanes, sulfonylbenzoylmethanes, imidosulfonates, and benzoin sulfonates; organic halogen compounds; and the like.

The thermal acid generator may be any known compound, such as an onium salt compound such as an aromatic diazonium salt, sulfonium salt, diaryliodonium salt, triarylsulfonium salt, or triarylselenium salt; a halogen compound; or a sulfonate ester.

The content of the acid generator is preferably 0.3 to 20% by mass, more preferably 0.5 to 10% by mass, and even more preferably 1 to 8% by mass, relative to 100% by mass of the total solids content of the curable resin composition.

(Polymerizable compound)
The curable resin composition of the present invention preferably further contains a polymerizable compound. By further containing a polymerizable compound, the curability of the curable resin composition is improved, and a cured product having excellent physical properties such as mechanical strength and solvent resistance can be obtained.

The polymerizable compound is a low-molecular-weight compound having a polymerizable unsaturated bond (also referred to as a polymerizable unsaturated group) that can be polymerized by exposure to active energy rays such as free radicals, electromagnetic waves (e.g., infrared rays, ultraviolet rays, X-rays, etc.), and electron beams. Examples include monofunctional compounds having one polymerizable unsaturated group in the molecule and polyfunctional compounds having two or more polymerizable unsaturated groups.

Examples of the monofunctional compounds include N-substituted maleimide monomers; (meth)acrylic acid esters; (meth)acrylamides; unsaturated monocarboxylic acids; unsaturated polycarboxylic acids; unsaturated monocarboxylic acids in which the unsaturated group and carboxyl group are chain-extended; unsaturated acid anhydrides; aromatic vinyls; conjugated dienes; vinyl esters; vinyl ethers; N-vinyl compounds; unsaturated isocyanates; and the like. Examples of these include the same compounds as those listed as monomer components of the acid group-containing polymer. Monomers having an active methylene group or an active methine group can also be used.

Examples of the polyfunctional compound include the following compounds.
bifunctional (meth)acrylate compounds such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, bisphenol A alkylene oxide di(meth)acrylate, and bisphenol F alkylene oxide di(meth)acrylate;

Trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, ethylene oxide-added ditrimethylolpropane tetra(meth)acrylate, ethylene oxide-added pentaerythritol tetra(meth)acrylate, ethylene oxide-added dipentaerythritol hexa(meth)acrylate, propylene oxide-added trimethylolpropane Tri(meth)acrylate, propylene oxide-added ditrimethylolpropane tetra(meth)acrylate, propylene oxide-added pentaerythritol tetra(meth)acrylate, propylene oxide-added dipentaerythritol hexa(meth)acrylate, ε-caprolactone-added trimethylolpropane tri(meth)acrylate, ε-caprolactone-added ditrimethylolpropane tetra(meth)acrylate, ε-caprolactone-added pentaerythritol tetra(meth)acrylate, ε-caprolactone-added dipentaerythritol hexa(meth)acrylate, dipentaerythritol pentaacrylate succinic acid-modified product, pentaerythritol triacrylate succinic acid-modified product, dipentaerythritol pentaacrylate phthalic acid-modified product, pentaerythritol triacrylate phthalic acid-modified product, the following formula:

A trifunctional or higher polyfunctional (meth)acrylate compound, such as a modified product of dipentaerythritol hexaacrylate represented by the formula:

Multifunctional vinyl ethers such as ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexavinyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether, and ethylene oxide-added dipentaerythritol hexavinyl ether;

(meth)acrylic acid esters containing a vinyl ether group, such as 2-vinyloxyethyl (meth)acrylate, 3-vinyloxypropyl (meth)acrylate, 1-methyl-2-vinyloxyethyl (meth)acrylate, 2-vinyloxypropyl (meth)acrylate, 4-vinyloxybutyl (meth)acrylate, 4-vinyloxycyclohexyl (meth)acrylate, 5-vinyloxypentyl (meth)acrylate, 6-vinyloxyhexyl (meth)acrylate, 4-vinyloxymethylcyclohexylmethyl (meth)acrylate, p-vinyloxymethylphenylmethyl (meth)acrylate, 2-(vinyloxyethoxy)ethyl (meth)acrylate, and 2-(vinyloxyethoxyethoxyethoxy)ethyl (meth)acrylate;

polyfunctional allyl ethers such as ethylene glycol diallyl ether, diethylene glycol diallyl ether, polyethylene glycol diallyl ether, propylene glycol diallyl ether, butylene glycol diallyl ether, hexanediol diallyl ether, bisphenol A alkylene oxide diallyl ether, bisphenol F alkylene oxide diallyl ether, trimethylolpropane triallyl ether, ditrimethylolpropane tetraallyl ether, glycerin triallyl ether, pentaerythritol tetraallyl ether, dipentaerythritol pentaallyl ether, dipentaerythritol hexaallyl ether, ethylene oxide-added trimethylolpropane triallyl ether, ethylene oxide-added ditrimethylolpropane tetraallyl ether, ethylene oxide-added pentaerythritol tetraallyl ether, and ethylene oxide-added dipentaerythritol hexaallyl ether;

Allyl group-containing (meth)acrylic acid esters such as allyl (meth)acrylate; polyfunctional (meth)acryloyl group-containing isocyanurates such as tri(acryloyloxyethyl)isocyanurate, tri(methacryloyloxyethyl)isocyanurate, alkylene oxide-added tri(acryloyloxyethyl)isocyanurate, and alkylene oxide-added tri(methacryloyloxyethyl)isocyanurate; polyfunctional allyl group-containing isocyanurates such as triallyl isocyanurate; polyfunctional urethane (meth)acrylates obtained by reacting polyfunctional isocyanates such as tolylene diisocyanate, isophorone diisocyanate, and xylylene diisocyanate with hydroxyl group-containing (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; polyfunctional aromatic vinyls such as divinylbenzene; etc. These polymerizable compounds may be used alone or in combination of two or more.

Among the polymerizable compounds, it is preferable to use a polyfunctional polymerizable compound from the viewpoint of further enhancing the curability of the curable resin composition. The number of functionalities of the polyfunctional polymerizable compound is preferably 3 or more, more preferably 4 or more. Moreover, the number of functionalities is preferably 10 or less, more preferably 8 or less.
The molecular weight of the polymerizable compound is not particularly limited, but is preferably 2,000 or less from the viewpoint of handling.

From the viewpoints of reactivity, economy, availability, etc., preferred examples of the polyfunctional polymerizable compound include compounds having a (meth)acryloyl group, such as polyfunctional (meth)acrylate compounds, polyfunctional urethane (meth)acrylate compounds, and (meth)acryloyl group-containing isocyanurate compounds, and more preferred examples include polyfunctional (meth)acrylate compounds. By including a compound having a (meth)acryloyl group, the curable resin composition has superior photosensitivity and curability, allowing for the production of a cured product with even greater hardness and transparency. It is even more preferred to use a tri- or higher functional polyfunctional (meth)acrylate compound as the polyfunctional polymerizable compound.

In the curable resin composition of the present invention, the content of the polymerizable compound is not particularly limited and may be set appropriately as long as the effects of the present invention are achieved. However, from the viewpoint of appropriate viscosity, the content is preferably 5 to 60% by mass, and more preferably 10 to 50% by mass, relative to 100% by mass of the total solids content of the curable resin composition.

(Other ingredients)
The curable resin composition of the present invention may contain other components as needed in addition to the above-mentioned components. Examples of such other components include solvents; colorants (pigments, dyes); dispersants; heat resistance improvers; leveling agents; developing aids; inorganic fine particles such as silica fine particles; silane-based, aluminum-based, and titanium-based coupling agents; fillers; thermosetting resins such as epoxy resins, phenolic resins, and polyvinylphenols; curing aids such as polyfunctional thiol compounds; plasticizers; polymerization inhibitors; ultraviolet absorbers; antioxidants; matting agents; defoaming agents; antistatic agents; slip agents; surface modifiers; thixotropic agents; thixotropic aids; quinone diazide compounds; polyhydric phenol compounds; cationically polymerizable compounds; acid generators; and the like. These may be used alone or in combination of two or more. These other components may be appropriately selected from known compounds and used, and the amount used may also be appropriately determined.
For example, when the curable resin composition is used for a color filter, the curable resin composition preferably contains a coloring material.

<Preparation of Curable Resin Composition>
The method for preparing the curable resin composition of the present invention is not particularly limited and may be a known method, for example, a method in which the above-mentioned components are mixed and dispersed using various mixers or dispersers. The mixing and dispersion step is not particularly limited and may be performed by a known method. In addition, other steps that are usually performed may be further included. When the curable resin composition contains a colorant, it is preferable to prepare it through a known colorant dispersion treatment step.

<Curing method>
The method for obtaining a cured product using the curable resin composition is not particularly limited, and any known method may be used, such as heating the curable resin composition, irradiating it with active energy rays such as ultraviolet rays, or a combination of these. For example, a preferred method includes a step of applying the curable resin composition to a substrate to form a coating film, a step of irradiating the formed coating film with light, and a step of heating the irradiated coating film.

The substrate is not particularly limited and may be selected appropriately depending on the purpose and application. Examples include substrates made of various materials such as glass plates and plastic plates.

The method for forming the coating film is not particularly limited, and can be any known method such as spin coating, slit coating, roll coating, or cast coating.

After applying the cured resin composition to a substrate, it is preferable to dry the applied product to form a coating film. This drying can be carried out by a known method, such as using a hot plate, IR oven, or convection oven. Drying conditions are appropriately selected depending on the boiling point of the solvent components contained, the type of curable component, the film thickness, and the performance of the dryer, but drying at a temperature of 50 to 160°C for 10 to 300 seconds is typically preferred.

The method for irradiating the formed coating film with light is not particularly limited and can be performed by any known method. Examples of light sources for actinic rays used for light irradiation include lamp light sources such as xenon lamps, halogen lamps, tungsten lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, medium-pressure mercury lamps, low-pressure mercury lamps, carbon arcs, and fluorescent lamps, and laser light sources such as argon ion lasers, YAG lasers, excimer lasers, nitrogen lasers, helium cadmium lasers, and semiconductor lasers.

When irradiating the coating film with light, the irradiation may be carried out through a photomask. A mask with light-shielding areas formed according to the desired pattern is preferably used as the photomask. When irradiating with light through a photomask, it is preferable to carry out a development process afterwards. The development process is a process in which, after the above-mentioned light irradiation process, the film is developed with a developer to remove the unexposed areas and form a pattern. The exposed areas are cured, and the cured product becomes insoluble or poorly soluble in the developer. On the other hand, the unexposed areas are soluble in the developer and are removed by the development process, resulting in a patterned cured film. The development process can usually be carried out at a development temperature of 10 to 50°C by methods such as immersion development, spray development, brush development, and ultrasonic development.

The developer used in the development step is not particularly limited as long as it dissolves the curable resin composition. Typically, an organic solvent or an alkaline aqueous solution is used, and a mixture of these may also be used. When an alkaline aqueous solution is used as the developer, it is preferable to wash with water after development. Examples of organic solvents and alkaline aqueous solutions include those similar to those described in JP 2015-157909 A.

In the process of heating the light-irradiated coating film (post-curing process), the heating temperature is preferably 100 to 350°C, more preferably 150 to 300°C, and even more preferably 200 to 250°C.

The heating time in the heating step is not particularly limited and may be set as appropriate, preferably for 5 to 60 minutes. The heating method is also not particularly limited, and can be performed using heating equipment such as a hot plate, convection oven, or high-frequency heater.

When the resulting cured product is a cured film, its thickness is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, and even more preferably 1 to 10 μm, in order to ensure sufficient heat resistance.

<Application>
The curable resin composition of the present invention can provide a cured product having excellent heat resistance. Therefore, it can be suitably used in applications requiring excellent heat resistance. The curable resin composition of the present invention is suitably used for optical materials and resists. The curable resin composition of the present invention can be suitably used for either negative or positive workpieces, but is preferably a negative workpiece photosensitive resin composition.

Specific examples of the curable resin composition of the present invention are suitable for use in various optical components and components of electrical and electronic devices, such as color filters, black matrices, photospacers, black column spacers, inks, printing plates, printed wiring boards, semiconductor elements, photoresists, insulating films, films, and organic protective films used in liquid crystal, organic electroluminescent, quantum dot, and micro LED liquid crystal displays, solid-state imaging devices, and touch panel display devices. The curable resin composition of the present invention is particularly suitable for use in displays, and can be used for color filters, organic protective films, and hard coats.

The present invention will be explained in more detail below with reference to the following examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass."

Each evaluation was carried out by the following method.
<Acid value>
3 g of the resin solution was precisely weighed and dissolved in a mixed solvent of 90 g of tetrahydrofuran (THF) and 10 g of water, and titrated using a 0.1 N KOH aqueous solution as a titrant. The titration was carried out using an automatic titrator (product name: COM-555, manufactured by Hiranuma Sangyo Co., Ltd.), and the acid value per 1 g of solid content (mg KOH/g) was calculated from the acid value of the resin solution and the solid content of the resin solution.
The solid content of the resin solution was determined by the following method.
Approximately 1 g of the resin solution was weighed into an aluminum cup, dissolved in approximately 3 g of THF, and then air-dried at room temperature. The resin solution was then dried in a hot air dryer (product name: PHH-101, manufactured by Espec Corporation) at 160°C under vacuum for 1.5 hours, then allowed to cool in a desiccator, and its mass was measured. The solid content (% by mass) of the resin solution was calculated from the mass loss.

<Weight average molecular weight>
The weight average molecular weight was measured by GPC (gel permeation chromatography) using polystyrene as a standard substance and tetrahydrofuran as an eluent, with an HLC-8220GPC (manufactured by Tosoh Corporation) and a column: TSKgel Super HZM-M (manufactured by Tosoh Corporation).

<Condensation rate>
The amount of water in the distillate distilled off during condensation was measured by the Karl Fischer method and calculated using the following formula.
Condensation rate (%) = (amount of water in the distillate) / (amount of water at 100% condensation (calculated value)) × 100

<Thermomechanical property analysis (TMA)>
The resulting siloxane compound was blended with 828EL (a bisphenol A-type epoxy resin manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 186, equimolar ratio of the carboxyl groups of the alkali-soluble silsesquioxane to the epoxy groups of the epoxy resin) and an epoxy curing agent (dicyandiamide, 0.5% based on the solid content of the silsesquioxane solution) in the proportions shown in Table 1 to prepare a thermosetting resin composition. The resulting thermosetting resin composition was applied to a polyethylene terephthalate film to a dry thickness of approximately 80 μm, dried at 90°C for 30 minutes, cured at 180°C for 1 hour, and then cooled. The peeled cured coating was then cut into 5 mm wide pieces to serve as measurement samples. The linear expansion coefficient (CTE 210-250) was measured at 210-250°C in tension mode with a chuck distance of 20 mm using a Bruker AXS TMA 4000 thermomechanical analyzer (manufactured by Bruker AXS Co., Ltd.).

Example 1
A separable flask equipped with a thermometer, a stirrer, a gas inlet tube, a condenser, and a dropping tank inlet was charged with 93 parts of 1-methyl-2-pyrrolidone (NMP), 50 parts of 3-aminopropyltriethoxysilane, and 43 parts of trimellitic anhydride, and after purging with nitrogen, the temperature was raised to 120°C and the mixture was stirred and mixed for 1 hour to produce silane compound A.
Silane compound A was then cooled to room temperature, and 146 parts of NMP, 150 parts of phenyltrimethoxysilane, and 53 parts of pure water were added thereto, followed by heating to 90°C to distill off the methanol and then heating to 160°C to distill off the water, yielding resin solution (silsesquioxane solution) 1.
Table 2 also shows the physical properties (acid value, weight average molecular weight) of the resulting silsesquioxane (siloxane compound).

Example 2
Silsesquioxane solution 2 was obtained in the same manner as in Example 1, except that the raw material for silane compound A, the silane compound added as the reaction raw material for the siloxane compound, water, and solvent were blended as shown in Table 2. The physical properties of the resulting siloxane compound are shown in Table 2.

Example 3
Silsesquioxane solution 3 was obtained in the same manner as in Example 1, except that the raw material for silane compound A, the silane compound added as the reaction raw material for the siloxane compound, water, and solvent were blended as shown in Table 2. The physical properties of the obtained siloxane compound are shown in Table 2.

(Comparative Example 1)
Silsesquioxane solution 4 was obtained in the same manner as in Example 1, except that the raw material for silane compound A, the silane compound added as the reaction raw material for the siloxane compound, water, and solvent were blended as shown in Table 2. The physical properties of the obtained siloxane compound are shown in Table 2.

The linear expansion coefficients of the siloxane compounds obtained in the above examples and comparative examples were evaluated using the method described above. The evaluation results are shown in Table 2.

Table 2 confirms that siloxane compounds containing an organic group with an imide bond and a carboxyl group have excellent heat resistance.

Claims (7)

A siloxane compound having an organic group having an imide bond and a carboxy group,
The organic group having an imide bond and a carboxy group is a group represented by the following general formula (1):
The siloxane compound has a structure represented by the following general formula (5) and a structure represented by the following general formula (6), and is characterized by having a weight average molecular weight of 500 to 50,000.
(In the formula, ^R1 and ^R2 are the same or different and represent a hydrocarbon group having 1 to 15 carbon atoms, a carboxy group, or a group formed by combining a hydrocarbon group having 1 to 15 carbon atoms with a carboxy group, and at least one of ^R1 and ^R2 is a group formed by combining a hydrocarbon group having 1 to 15 carbon atoms with a carboxy group. ^R1 and ^R2 may be linked to each other to form a ring structure. ^R3 represents a direct bond or a divalent organic group having 1 to 10 carbon atoms. * represents the bonding site of the organic group having the imido bond and the carboxy group.)
(In the formula, ^R7 represents an organic group having the imide bond and a carboxy group.)
(In the formula, ^R8 represents an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms. ) The siloxane compound according to claim 1, characterized in that it has an organic group having at least one group selected from the group consisting of a (meth)acryloyl group, a vinyl group, and an epoxy group. The siloxane compound according to claim 1 or 2, characterized in that it has an acid value of 30 to 500 mg KOH/g. A curable resin composition comprising the siloxane compound according to any one of claims 1 to 3 and a photopolymerization initiator and/or an acid generator. The curable resin composition according to claim 4, characterized in that it contains a polymerizable compound. The curable resin composition according to claim 4 or 5, which is a negative-type photosensitive resin composition. A method for producing the siloxane compound according to claim 1,
The method includes a step of reacting an amino group-containing silane compound with a compound having an acid anhydride group and a carboxy group, and a step of condensing a reaction raw material including an imide bond-containing silane compound produced in the reaction step and a silane compound having an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms,
The imide bond-containing silane compound is a compound represented by the following general formula (2): R ⁴ _a R ⁵ _b SiR ⁶ _[4−(a+b)] (2)
(In the formula, ^R4 represents an organic group having an imide bond and a carboxy group, represented by the following general formula (1); ^R5 represents an organic group not containing an imide bond; ^R6 represents an alkoxy group; a is 1; and b is 0.)
(In the formula, ^R1 and ^R2 are the same or different and represent a hydrocarbon group having 1 to 15 carbon atoms, a carboxy group, or a group formed by combining a hydrocarbon group having 1 to 15 carbon atoms with a carboxy group, and at least one of ^R1 and ^R2 is a group formed by combining a hydrocarbon group having 1 to 15 carbon atoms with a carboxy group. ^R1 and ^R2 may be linked to each other to form a ring structure. ^R3 represents a direct bond or a divalent organic group having 1 to 10 carbon atoms. * represents the bonding site of the organic group having the imido bond and the carboxy group.)
A method for producing a siloxane compound, comprising: