JP2008088415A - Acyloxy group-containing silicone copolymer, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new silicone copolymer which is excellent in the transparency of a light having wavelength in the visible ray region and which has high thermal resistance and the characteristics allowing the formation of a film excellent in crack resistance and solvent resistance. <P>SOLUTION: The silicone copolymer includes a silsesquioxane unit containing an acyloxy group expressed by the general formula (wherein, A and X are each a hydrocarbon group). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a silicone copolymer having an acyloxy group that is useful as an insulating film material for electronic components such as liquid crystal display elements and semiconductor elements.

In recent years, insulating films used in electronic components such as liquid crystal display elements and semiconductor elements include high transparency with high transparency to visible light, and heat resistance and chemical resistance that can withstand various processing steps when manufacturing elements. There is an increasing need for resins having characteristics such as crack resistance. Among them, a silicone resin having a silsesquioxane skeleton has excellent performance in optical characteristics and heat resistance, and has been widely used by utilizing these characteristics.
However, the cured film has a thickness of 1 μm or more, and the film is liable to crack, and its application is limited.

  An example of an epoxy group-containing silicone resin is disclosed as a material having crack resistance, which is an important characteristic (see Patent Document 1). However, although the crack resistance is excellent, it cannot withstand a heat treatment step of 300 ° C. or higher, and the heat resistance is insufficient.

On the other hand, an example in which silsesquioxane is used as an interlayer insulating film has been reported as the speed and integration of LSI elements increase (see Patent Document 2). However, the materials described here can provide materials with excellent transmittance in the visible light region and excellent heat resistance. However, when the film thickness is 1 μm or more, cracks easily occur and the film thickness is increased. In addition, there is a problem in resistance to the solvent used during the process of forming the insulating film.
JP 2001-040094 A JP 2000-281904 A

  The present invention was made for the purpose of providing a novel silicone copolymer having excellent transparency at a wavelength in the visible light region, high heat resistance, and the ability to form a film excellent in crack resistance and solvent resistance. Is.

  The present invention is a silicone copolymer comprising a silsesquioxane unit containing an acyloxy group having a specific structure and a silsesquioxane unit containing an aromatic or alicyclic hydrocarbon group.

  The silicone copolymer of the present invention contains silsesquioxane containing an acyloxy group, so that it has excellent transparency in the visible light region, and has a very high crack resistance and solvent resistance when a film is formed by heating. In addition, by introducing a silsesquioxane unit containing an aromatic hydrocarbon group or an alicyclic hydrocarbon group, a material having improved heat resistance at 300 ° C. or higher is obtained.

    In addition, since an acyloxy group is easily eliminated by an alkali to form a hydroxyl group, a heat-resistant material having a hydroxyl group or a heat-resistant material having another substituent by reacting a hydroxyl group as a base. Therefore, the silicone copolymer of the present invention can be applied not only to electronic parts but also to a wide range of fields such as paints and adhesives.

  The silicone copolymer having an acyloxy group of the present invention has good transparency at a wavelength in the visible light region, is excellent in heat resistance, crack resistance, and solvent resistance.

  The silicone copolymer of the present invention has the following general formula:

(In the formula, A and X represent hydrocarbon groups.)
Silsesquioxane unit containing an acyloxy group represented by the following general formula

(In the formula, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group.)
It is a silicone copolymer characterized by including the silsesquioxane unit shown by these.

  As a preferable hydrocarbon group as A, as a C1-C20 linear hydrocarbon group, hydrocarbon groups, such as a methylene group, ethylene group, a propylene group, a butylene group, a pentylene group, are mentioned, for example. The branched hydrocarbon group is preferably a hydrocarbon group such as an isopropylene group or an isobutylene group. As the cyclic hydrocarbon group, a cyclic hydrocarbon group such as a cyclopentylene group, a cyclohexylene group, and a cycloheptylene group is preferable, and a bridged cyclic hydrocarbon group having a norbornane skeleton is also preferable. Among these hydrocarbon groups, straight chain hydrocarbon groups having 1 to 7 carbon atoms such as methylene group, ethylene group and propylene group, cyclic hydrocarbon groups such as cyclopentylene group and cyclohexylene group, and norbornane. Such a crosslinked cyclic hydrocarbon group is particularly preferred for the synthesis.

  Preferred examples of the hydrocarbon group represented by X include carbon atoms such as methyl, ethyl, n-propyl, n-butyl, and n-pentyl groups as linear hydrocarbon groups having 1 to 20 carbon atoms. A hydrogen group is mentioned. The branched hydrocarbon group is preferably a hydrocarbon group such as an iso-propyl group or an iso-butyl group. The cyclic hydrocarbon group is preferably a cyclic hydrocarbon group such as a cyclopentyl group, a cyclohexyl group, or a cycloheptylene group, and may be a bridged cyclic hydrocarbon group having a norbornane skeleton or an adamantane skeleton. Among these hydrocarbon groups, straight chain hydrocarbon groups having 1 to 5 carbon atoms such as a methyl group, an ethyl group, and a propyl group are more preferable, and a methyl group is most preferable from the viewpoint of obtaining raw materials.

  The substituent represented as R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group. Preferable examples include aromatic hydrocarbon groups such as phenyl group, naphthyl group, anthracenyl group, phenanthrenyl group and pyrenyl group, alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group and cyclopentyl group, and bridged alicyclic hydrocarbon groups. Is preferred. A substituent may be bonded to the aromatic hydrocarbon group or alicyclic hydrocarbon group. From the viewpoint of obtaining raw materials, a phenyl group, a naphthyl group, a norbornenyl group, and an adamantyl group are more preferable.

  The silicone copolymer of the present invention preferably has the following general formula

(In the formula, A represents a hydrocarbon group.)
A silsesquioxane unit containing an acetoxy group represented by the following general formula

(In the formula, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group.)
A silicone copolymer containing a silsesquioxane unit represented by the following general formula:

(In the formula, A and B represent a hydrocarbon group, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group, a, b and c each represents mol%, and a represents 1 to 99 mol%. B represents 1 to 99 mol%, and c represents 1 to 99 mol%, provided that a + b + c = 100.
It is a silicone copolymer shown by these.

  The silicone copolymer of the present invention preferably has a weight average molecular weight (polystyrene conversion) in the range of 500 to 20,000, more preferably in the range of 500 to 8,000. The silicone copolymer of the present invention preferably has a dispersity in the range of 1.1 to 2.5, and more preferably in the range of 1.1 to 1.8.

  The silicone copolymer of the present invention is preferably soluble in an organic solvent, and is a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methylcyclohexanone, methanol, ethanol, isopropanol, n-butanol, cyclohexanol. Alcohol solvents such as benzene, toluene, xylene, etc., ester solvents such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, ether solvents such as diethyl ether, dibutyl ether, tetrahydrofuran, acetonitrile, benzonitrile Soluble in glycol solvents such as nitrile solvents such as propylene glycol dimethyl ether, propylene glycol diethyl ether and propylene glycol monomethyl ether acetate.

  In the silicone copolymer of the present invention, the following skeleton is:

A silsesquioxane skeleton is shown, and each silicon atom is bonded to three oxygen atoms, and each oxygen atom is bonded to two silicon atoms.

  Moreover, the silicone copolymer of the present invention has, for example, the following general formula:

(In the formula, A, B and X represent a hydrocarbon group, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group. A, b and c each represents mol%, and a represents 1 to 99. (Mol%, b represents 1 to 99 mol%, and c represents 1 to 99 mol%, provided that a + b + c = 100.)
Can be represented by the structural formula shown below.

  Moreover, the silicone copolymer of the present invention has, for example, the following general formula:

(In the formula, A, B and X represent a hydrocarbon group, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group. A, b and c each represents mol%, and a represents 1 to 99. (Mol%, b represents 1 to 99 mol%, and c represents 1 to 99 mol%, provided that a + b + c = 100.)
The ladder type silicone copolymer shown in FIG.

  Here, the following general formula, which is a preferred form of the silicone copolymer of the present invention:

(In the formula, A, B and X represent a hydrocarbon group, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group. A, b and c each represents mol%, and a represents 1 to 99. (Mol%, b represents 1 to 99 mol%, and c represents 1 to 99 mol%, provided that a + b + c = 100.)
The hydrocarbon group represented by A is preferably a linear, branched or cyclic hydrocarbon having 1 to 20 carbon atoms, and may be a crosslinked cyclic hydrocarbon group.

  As a preferable hydrocarbon group as A, as a C1-C20 linear hydrocarbon group, hydrocarbon groups, such as a methylene group, ethylene group, a propylene group, a butylene group, a pentylene group, are mentioned, for example. The branched hydrocarbon group is preferably a hydrocarbon group such as an isopropylene group or an isobutylene group. As the cyclic hydrocarbon group, a cyclic hydrocarbon group such as a cyclopentylene group, a cyclohexylene group, and a cycloheptylene group is preferable.

A crosslinked cyclic hydrocarbon group having a norbornane skeleton shown in FIG. Among these hydrocarbon groups, straight chain hydrocarbon groups having 1 to 7 carbon atoms such as methylene group, ethylene group and propylene group, cyclic hydrocarbon groups such as cyclopentylene group and cyclohexylene group, and norbornane. Such a crosslinked cyclic hydrocarbon group is particularly preferred for the synthesis.

  Preferred examples of the hydrocarbon group represented by X include carbon atoms such as methyl, ethyl, n-propyl, n-butyl, and n-pentyl groups as linear hydrocarbon groups having 1 to 20 carbon atoms. A hydrogen group is mentioned. The branched hydrocarbon group is preferably a hydrocarbon group such as an iso-propyl group or an iso-butyl group. As the cyclic hydrocarbon group, a cyclic hydrocarbon group such as a cyclopentyl group, a cyclohexyl group, or a cycloheptylene group is preferable.

A bridged cyclic hydrocarbon group having a norbornane skeleton or an adamantane skeleton shown in FIG. Among these hydrocarbon groups, straight chain hydrocarbon groups having 1 to 5 carbon atoms such as a methyl group, an ethyl group, and a propyl group are more preferable, and a methyl group is most preferable from the viewpoint of obtaining raw materials.

  The substituent represented by R is a thermally stable aromatic hydrocarbon group or alicyclic hydrocarbon group. Preferred examples include an aromatic hydrocarbon group such as phenyl group, naphthyl group, anthracenyl group, phenanthrenyl group and pyrenyl group, an alicyclic hydrocarbon group such as cyclopentyl group, cyclohexyl group and cyclopentyl group, and the following general formula:

The crosslinked alicyclic hydrocarbon group shown in FIG. A substituent may be bonded to the aromatic hydrocarbon group or alicyclic hydrocarbon group. From the viewpoint of obtaining raw materials, a phenyl group, a naphthyl group, a norbornenyl group, and an adamantyl group are more preferable.

  As a preferable example of the hydrocarbon group represented by B, the linear hydrocarbon group having 1 to 20 carbon atoms includes carbon such as methyl group, ethyl group, n-propyl group, n-butyl group, and n-pentyl group. A hydrogen group is mentioned. The branched hydrocarbon group is preferably a hydrocarbon group such as an iso-propyl group or an iso-butyl group. Among these hydrocarbon groups, a straight-chain hydrocarbon group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, and a propyl group is more preferable. By introducing a sterically small substituent, silicon in the molecule can be obtained. The content (ratio of SiO in the polymer) can be increased, and the characteristics of siloxane can be fully utilized.

  Particularly preferred examples of the silicone copolymer of the present invention are shown in the following general formula.

(In the formula, A represents a hydrocarbon group. A, b and c each represents mol%, a represents 1 to 99 mol%, b represents 1 to 99 mol%, and c represents 1 to 99 mol%. However, a + b + c = 100.)
Here, as a composition ratio of the silicone copolymer of this invention, a is 1-99 mol%, b is 1-99 mol%, c is 1-99 mol%, However, it becomes a + b + c = 100.
Here, a component shows the silicone part which has a substituent containing an acyloxy group, and 5 mol% or more is preferable, and especially 10 mol% or more is more preferable in order to satisfy heat resistance and solvent resistance.

  The component b represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group, but in order to obtain a thermally stable silicone copolymer, it is preferably at least 20 mol%, particularly preferably at least 40 mol%.

  B of the component c indicates a composition containing a hydrocarbon group, and it is more preferable to use lower alkyl for the component c. However, the solvent characteristics are improved, and the silicon content in the polymer (ratio of SiO in the polymer) Therefore, the content is preferably 10 mol% or more, and more preferably 20 mol% or more.

  Here, the following general formula, which is a preferred form of the silicone copolymer of the present invention:

(In the formula, A, B and X represent a hydrocarbon group, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group. A, b and c each represents mol%, and a represents 1 to 99. (Mol%, b represents 1 to 99 mol%, and c represents 1 to 99 mol%, provided that a + b + c = 100.)
In the case of producing a silicone copolymer represented by the following, for example, it can be synthesized by a hydrolysis reaction or a polycondensation reaction using water shown below.

(In the formula, A, B, and X represent a hydrocarbon group, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group, Y represents a hydrolyzable group, and a, b, and c each represent a mole. A represents 1 to 99 mol%, b represents 1 to 99 mol%, and c represents 1 to 99 mol%, provided that a + b + c = 100.)
Here, Y represents a hydrolyzable group, preferably a halogen atom of chlorine, bromine or iodine, or an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group or a butoxy group, particularly a chlorine atom, a methoxy group or an ethoxy group. Is particularly preferred because of the availability of raw materials and high reactivity.

  This hydrolysis and polycondensation reaction is carried out using water, but it is usually preferred to carry out by adding a catalyst. Since the acyloxy group is weak to basic conditions, it is preferably carried out under acidic conditions, and it is particularly preferred to use a catalyst such as hydrochloric acid, acetic acid, citric acid, or oxalic acid. The amount of the catalyst used is preferably 0.01 to 1.0 equivalent, more preferably 0.05 to 0.5 equivalent, relative to the number of moles of the raw material monomer.

  As the hydrolysis and polycondensation conditions, a reaction temperature of 0 to 100 ° C. is preferable, and the reaction proceeds easily by using a catalyst, and therefore 10 to 40 ° C. is more preferable.

  Although water is required for this hydrolysis and polycondensation reaction, it is preferable to use 3 to 100 equivalents, particularly preferably 5 to 50 equivalents, based on the number of moles of the raw material monomer.

  In this reaction, an organic solvent is preferably used. Examples of the organic solvent include aprotic solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and alcohol solvents such as methanol, ethanol and 2-propanol. , Ether solvents such as diethyl ether and tetrahydrofuran, and the like can be used.

  After completion of the reaction, a non-polar solvent is added to separate the reaction product and water, and the reaction product dissolved in an organic solvent is recovered. After washing with water, the solvent is distilled off to obtain the desired product. Can be obtained.

  In this way, a silicone copolymer having an acyloxy group can be synthesized.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

  In the following examples, the following apparatus was used for the measurement, and general reagents purchased from reagent manufacturers (Tokyo Chemicals, Wako Pure Chemicals, Nacalai Tesque, Azmax, Shin-Etsu Chemical) were used as raw materials.

measuring device
NMR measurement: JEOL 400MHz NMR measuring instrument
IR measurement: IR Prestige-21 made by Shimadzu. A small amount of a synthetic product was applied to a KBr plate, and sandwiched between other KBr plates to transmit infrared light.

GPC measurement: Tosoh HLC-8220
GC measurement: Shimadzu GC-2010 series.

Synthesis example 1
Example of synthesis of 3-acetoxypropyltrimethoxysilane To a 1 L four-necked flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer, 500 g of toluene, 250.0 g of 3-chloropropyltrimethoxysilane (1.258 mol) And 129.6 g (1.321 mol) of potassium acetate were added and stirred, and 5.84 g (0.0181 mol) of tetra-n-butylammonium bromide was added and reacted at 90-100 ° C. for 2 hours. Next, the salt produced after cooling was suction filtered to obtain a yellow solution. Toluene was distilled off under reduced pressure with an evaporator, and further distilled under reduced pressure to obtain 162.8 g (0.732 mol) of a colorless transparent fraction having a distillation degree of 80 to 81 ° C. at a reduced pressure of 0.4 kPa. It was. As a result of GC analysis of the obtained fraction, GC purity was 99.0%. As a result of NMR and IR analysis, it was 3-acetoxypropyltrimethoxysilane.

  The spectrum data of the obtained compound is shown below.

Infrared absorption spectrum (IR) data
^{2841,2945cm -1 (-CH3), 1740cm -1} (-CO -), 1086 cm -1 (Si-O)
Nuclear magnetic resonance spectra (NMR) data ^{(1 H-NMR δ (ppm} ), solvent: CDCl?)
0.644-0.686 (dd, 2H, -CH2-), 1.703-1.779 (m, 2H, -CH2-), 2.045 (s, 3H, CH3CO-), 3.575 (s, 9H, CH3O-), 4.019-4.052 ( t, 2H, -COO-CH2-).

Synthesis example 2
Synthesis example of (5-acetoxynorbornane-2 (or 3) -yl) triethoxysilane Into a 1 L 4-neck flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer, 5-norbornen-2-yl acetate 60.0 mL of an isopropyl alcohol solution of 0.1 mol / L chloroplatinic acid was added to 400.0 g (2.63 mol), and 453.3 g (2.76 mol) of triethoxylane was added dropwise at a reaction temperature of 80 to 90 ° C. After completion of dropping, the mixture was aged at the same temperature for 2 hours. Next, vacuum distillation was performed after cooling to obtain 507.4 g (1.60 mol) of a colorless and transparent fraction having a distillation pressure of 110 to 115 ° C. at a reduced pressure of 0.2 kPa. As a result of GC analysis and GCMS analysis of the obtained fraction, the GC purity was 96.3%. As a result of NMR and IR analysis, it was (5-acetoxynorbornane-2 (or 3) -yl) triethoxysilane.

  The spectrum data of the obtained compound is shown below.

Infrared absorption spectrum (IR) data
2880-3060cm ^-1 (-CH2-,-CH3), 1730cm ^-1 (-CO-), 1080-1170 cm ^-1 (Si-O)
Nuclear magnetic resonance spectra (NMR) data ^{(1 H-NMR δ (ppm} ), solvent: CDCl?)
0.787-0.828 (m, 1H), 1.016-1.049 (m, 1H), 1.165-1.206 (m, 9H), 1.267-1.744 (m, 4H), 1.852-2.030 (m, 1H), 1.997 (s, 3H ), 2.278-2.489 (m, 2H), 3.760-3.821 (m, 6H), 4.540-4.944 (m, 1H).

Example 1
Synthesis of the following structural formula (3-acetoxypropylsilsesquioxane / phenylsilsesquioxane / methylsilsesquioxane copolymer)

(20:50:30 in the structural formula is the molar ratio of the raw materials used)
A 500 mL four-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 55.8 g of toluene and 35.7 g of water, and 3.12 g (0.03 mol) of 35% hydrochloric acid was added. . Next, 13.5 g (0.0605 mol) of 3-acetoxypropyltrimethoxysilane, 30.0 g (0.151 mol) of phenyltrimethoxysilane and 12.4 g (0.0908 mol) of methyltrimethoxysilane in toluene 27. 9 g of the solution was added dropwise at 20-30 ° C. After completion of dropping, the mixture was aged at the same temperature for 2 hours. As a result of analyzing the reaction solution at this time by GC, it was found that no raw material remained. Next, toluene and water were added for extraction, and after washing with an aqueous sodium hydrogen carbonate solution, the solution was washed with water until the solution became neutral. The toluene oil layer was recovered, and toluene was removed to obtain 34.6 g of the target viscous liquid compound.

  The spectrum data of the obtained copolymer is shown below.

Infrared absorption spectrum (IR) data
1030-1134cm ^-1 (Si-O), 1271 cm ^-1 (-O-), 1713 cm ^-1 (-CO-), 2970-3073 cm ^-1 (CH), 3080-3700 cm ^-1 (Si- OH)
Nuclear magnetic resonance spectrum (NMR) data ( ¹ H-NMR δ (ppm), solvent: CDCl ₃ )
0.17 (bs), 0.51-0.81 (m), 1.50-2.10 (m), 3.60-4.20 (m), 6.90-7.47 (m), 7.47-7.70 (m)
GPC analysis data: Mw = 1,020, Mw / Mn = 1.22 (polystyrene conversion).

Example 2
Synthesis of the following structural formula (3-acetoxypropylsilsesquioxane / 2-norbornenylsilsesquioxane / methylsilsesquioxane copolymer)

(20:50:30 in the structural formula is the molar ratio of the raw materials used)
The target compound, 38.7 g, was prepared in the same manner as in Example 1 except that phenyltrimethoxysilane, which is the raw material described in Example 1, was changed to 39.0 g (0.151 mol) of 2-norbornenyltriethoxysilane. Got.

Infrared absorption spectrum (IR) data
1047-1123cm ^-1 (Si-O), 1269 cm ^-1 (-O-), 1713 cm ^-1 (-CO-), 2866-2965 cm ^-1 (CH), 3080-3700 cm ^-1 (Si- OH)
Nuclear magnetic resonance spectrum (NMR) data ( ¹ H-NMR δ (ppm), solvent: CDCl ₃ )
0.16 (bs), 0.60-1.79 (m), 1.79-2.62 (m), 6.95-7.49 (m), 7.49-7.70 (m)
GPC analysis data: Mw = 2,140, Mw / Mn = 1.33 (polystyrene conversion).

Example 3
Synthesis of the following structural formula (5-acetoxynorbornane-2 (or 3) -yl) silsesquioxane / phenylsilsesquioxane / methylsilsesquioxane copolymer)

(20:50:30 in the structural formula is the molar ratio of the raw materials used)
Example 3 except that 3-acetoxypropyltrimethoxysilane, which is the raw material described in Example 1, was changed to 39.0 g (0.151 mol) of (5-acetoxynorbornane-2 (or 3) -yl) triethoxysilane In the same manner as in Example 1, 38.7 g of the target compound was obtained.

Infrared absorption spectrum (IR) data
1030-1134cm ^-1 (Si-O), 1271 cm ^-1 (-O-), 1713 cm ^-1 (-CO-), 2872-3073 cm ^-1 (CH), 3080-3700 cm ^-1 (Si- OH)
Nuclear magnetic resonance spectrum (NMR) data ( ¹ H-NMR δ (ppm), solvent: CDCl ₃ )
0.16 (bs), 0.60-1.79 (m), 1.79-2.62 (m), 4.70-5.00 (m), 6.90-7.47 (m), 7.47-7.80 (m)
GPC analysis data: Mw = 1,230, Mw / Mn = 1.31 (polystyrene conversion).

Example 4
Synthesis of the following structural formula (3-acetoxypropylsilsesquioxane / phenylsilsesquioxane copolymer)

(20:80 in the structural formula is the molar ratio of the raw materials used)
A 500 mL four-necked flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer was charged with 38.4 g of methanol and 21.0 g of water, and 1.13 g (0.0189 mol) of acetic acid was added. Next, a solution of 19.2 g of methanol containing 8.41 g (0.0378 mol) of 3-acetoxypropyltrimethoxysilane and 30.0 g (0.151 mol) of phenyltrimethoxysilane was added dropwise at 20 to 30 ° C. After completion of dropping, the mixture was aged at the same temperature for 2 hours. As a result of analyzing the reaction solution at this time by GC, it was found that no raw material remained. Next, toluene was added for extraction, and after washing with an aqueous sodium hydrogen carbonate solution, the solution was washed with water until the solution became neutral. The toluene oil layer was recovered and toluene was removed to obtain 24.6 g of the target viscous liquid compound.

  The spectrum data of the obtained copolymer is shown below.

Infrared absorption spectrum (IR) data
1030-1134cm ^-1 (Si-O), 1274cm ^-1 (-O-), 1713 cm ^-1 (-CO-), 2893-3073 cm ^-1 (CH), 3080-3700 cm ^-1 (Si-OH )
Nuclear magnetic resonance spectrum (NMR) data ( ¹ H-NMR δ (ppm), solvent: CDCl ₃ )
0.10-0.78 (m), 1.33-2.10 (m), 3.20-4.20 (m), 6.80-7.47 (m), 7.47-7.70 (m)
GPC analysis data: Mw = 1,430, Mw / Mn = 1.36 (polystyrene conversion).

Comparative Example 1
Synthesis of the following structural formula (phenylsilsesquioxane)

(20:80 in the structural formula is the molar ratio of the raw materials used)
A 500 mL four-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 55.8 g of toluene and 35.7 g of water, and 3.12 g (0.03 mol) of 35% hydrochloric acid was added. . Next, a solution of 27.9 g of toluene in 48.0 g (0.242 mol) of phenyltrimethoxysilane was added dropwise at 20 to 30 ° C. After completion of dropping, the mixture was aged at the same temperature for 2 hours. As a result of analyzing the reaction solution at this time by GC, it was found that no raw material remained. Next, toluene and water were added for extraction, and after washing with an aqueous sodium hydrogen carbonate solution, the solution was washed with water until the solution became neutral. The toluene oil layer was recovered, and toluene was removed to obtain 34.6 g of the target viscous liquid compound.

  The spectrum data of the obtained copolymer is shown below.

Infrared absorption spectrum (IR) data
1047-1123cm ^-1 (Si-O), 2978-3073 cm ^-1 (CH)
Nuclear magnetic resonance spectrum (NMR) data ( ¹ H-NMR δ (ppm), solvent: CDCl ₃ )
6.70-7.80 (m)
GPC analysis data: Mw = 1,410, Mw / Mn = 1.31 (polystyrene conversion).

<Manufacture of insulation coating>
The silicone compounds produced according to Examples 1 to 4 and Comparative Example 1 were each dissolved in propylene glycol monomethyl ether acetate to obtain a solution adjusted to a solid content concentration of 30% by weight. Thereafter, the solution was filtered with a PTFE filter, and applied on a silicon wafer or glass substrate by spin-coating for 30 seconds at a rotational speed such that the film thickness after removal of the solvent was 3.0 μm. Thereafter, the solvent was removed over 150 ° C./2 minutes, and then the film was finally cured over 350 ° C./30 minutes in a quartz tube furnace in which the O 2 concentration was controlled to less than 1000 ppm to obtain an insulating coating.

<Evaluation of coating>
The film was evaluated by the following method for the film formed by the film forming method.

(Measurement of transmittance)
The transmittance of 300 nm to 800 nm was measured using Hitachi UV3310 for the coating applied on the glass substrate having no absorption in the visible light region.

[Evaluation of heat resistance]
Regarding the final cured film formed on the silicon wafer, the film thickness after removal of the solvent and the film thickness after final curing were determined to be ○ when the film thickness reduction rate was less than 10%, and when the film thickness was 10% or more. The film thickness was measured with an ellipsometer L116B manufactured by Gartner. Specifically, the film thickness obtained from the phase difference caused by irradiation with He—Ne laser on the coating was used.

[Evaluation of crack resistance]
With respect to the final cured film formed on the silicon wafer, the presence or absence of in-plane cracks at a magnification of 10 to 100 times was confirmed with a metal microscope. The case where no crack was generated was judged as ◯, and the case where a crack was seen was judged as ×.

[Evaluation of solvent resistance]
The final cured film formed on the silicon wafer was immersed in a dimethyl sulfoxide solvent heated to a temperature of 90 ° C. for 120 minutes to test whether the film surface was rough, the film peeled, or dissolved. When the film surface was rough, the film was peeled off, or the film was not dissolved, it was judged as ○, and when the film surface was rough, the film was peeled or melted, it was judged as x. <Evaluation Result>
The evaluation results of the insulating film are shown in Table 1 below.

  Thus, by introducing an acyloxy group, the material satisfies all of heat resistance, crack resistance and solvent resistance.

Claims (6)

The following general formula

(In the formula, A and X represent hydrocarbon groups.)
Silsesquioxane unit containing an acyloxy group represented by the following general formula

(In the formula, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group.)
Silicone copolymer containing silsesquioxane unit represented by The following general formula

(In the formula, A represents a hydrocarbon group.)
A silsesquioxane unit containing an acetoxy group represented by the following general formula

(In the formula, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group.)
The silicone copolymer of Claim 1 containing the silsesquioxane unit shown by these. The following general formula

(In the formula, A represents a hydrocarbon group.)
Silsesquioxane unit represented by the following general formula

(In the formula, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group.)
Silsesquioxane unit represented by the following general formula

(In the formula, B represents a hydrocarbon group.)
The silicone copolymer of Claim 1 or 2 containing the silsesquioxane unit shown by these. The following general formula

(In the formula, A and B represent a hydrocarbon group, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group, a, b and c each represents mol%, and a represents 1 to 99 mol%. B represents 1 to 99 mol%, and c represents 1 to 99 mol%, provided that a + b + c = 100.
The silicone copolymer of Claim 1 to 3 shown by these 5. The silicone copolymer according to claim 1, which has a weight average molecular weight of 500 to 20,000, a dispersity of 1.1 to 2.5, and is soluble in an organic solvent. The following general formula

(In the formula, A and X represent a hydrocarbon group, and Y represents a hydrolyzable group.)
And the following general formula

(In the formula, R represents an aromatic hydrocarbon group or an alicyclic hydrocarbon group, and Y represents a hydrolyzable group.)
And the following general formula

(In the formula, B represents a hydrocarbon group, and Y represents a hydrolyzable group.)
The method for producing a silicone copolymer according to claim 1, wherein the monomer represented by the formula is hydrolyzed under acidic conditions.