JP7152749B2 - Polysilsesquioxane and method for producing the same - Google Patents

Description

The present invention relates to a polysilsesquioxane (PSQ) and its production method.

Silsesquioxane is a general term for polysiloxanes whose basic structural units (silicon-containing bonding units) are T units (RSiO _3/2 ). In T units, the silicon atom in the silsesquioxane is bonded to 3 oxygen atoms, which are bonded to 2 silicon atoms, so that the ratio of oxygen atoms to silicon atoms is 1.5. 5.

For example, alkylsilsesquioxane, which is one type of silsesquioxane, has T units represented by T ¹ to T ³ below. Note that T ⁰ actually corresponds to the unreacted monomer contained in the silsesquioxane and is not a silicon-containing bonding unit.

(In the above formula, R represents an alkyl group or the like, and X represents a hydrogen atom or an alkyl group.)

Polysilsesquioxanes can be produced by hydrolyzing and condensing trifunctional silanes. The polysilsesquioxane obtained by this method contains not only the random structure polysilsesquioxane (main product) but also by-products such as the polyhedral polysilsesquioxane shown below. High turbidity.

(In the above formula, R is the same as described above.)

(In the above formula, R is the same as described above.)

As a method for purifying polysilsesquioxane, for example, there is a method described in Patent Document 1. Patent Document 1 describes (1) contacting a composition containing both a polyhedral oligosilsesquioxane and an alkali metal compound with a hydrophobic organic solvent to dissolve the polyhedral oligosilsesquioxane in the hydrophobic organic solvent. (2) separating the fine particle dispersion from the organic phase containing the polyhedral oligosilsesquioxane obtained in the previous step and the fine particle dispersion; (3) a step of precipitating the polyhedral oligosilsesquioxane by further adding a poor solvent for the polyhedral oligosilsesquioxane to the solution containing the polyhedral oligosilsesquioxane obtained in step (2); A method of including is described.

However, the method of Patent Document 1 is a method of purifying a polyhedral oligosilsesquioxane using a nitrile solvent, and is not a method of obtaining PSQ with a random structure.

JP 2005-187381 A

A main object of the present invention is to provide a method for producing a polysilsesquioxane having low turbidity and high storage stability.

Furthermore, another object of the present invention is to provide a polysilsesquioxane with low turbidity and high storage stability.

The present inventors have made intensive studies to develop a method for producing a polysilsesquioxane with low turbidity and high storage stability. We have found that the above problems can be solved by adding a poor solvent to remove by-products such as polyhedral polysilsesquioxane. The present invention has been completed based on such findings.

The present invention relates to a polysilsesquioxane and a method for producing the same, as shown in items 1 to 10 below.

Item 1: A methyl isobutyl ketone solution containing 71% by mass of a polysilsesquioxane represented by the following general formula (1) and containing a polysilsesquioxane having a random structure as a main component. turbidity of 50 FTU or less.
[RSiO _1.5 ] _m [R'SiO _1.5 ] _n (1)
(In the formula, R represents a linear alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms.
R' represents fluoro (alkyl group having 1 to 4 carbon atoms).
m represents an integer of 5 to 100,000, and n represents an integer of 0 to 100,000.
m R's and n R's (when n is 2 or more) may be the same or different. )
Item 2 The content of silicon-containing bond units T ³ (here, T ³ is a silicon-containing bond unit in which all three oxygen atoms bonded to a silicon atom are bonded to other silicon atoms) is 60 mol% or more. The polysilsesquioxane according to item 1 above.
Item 3. The polysilsesquioxane according to item 1 or 2, which has a polystyrene-equivalent weight average molecular weight of 2,000 to 100,000.
Item 4 The following general formula (1):
[RSiO _1.5 ] _m [R'SiO _1.5 ] _n (1)
(In the formula, R represents a linear alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms.
R' represents fluoro (alkyl group having 1 to 4 carbon atoms).
m represents an integer of 5 to 100,000, and n represents an integer of 0 to 100,000.
m R's and n R's (when n is 2 or more) may be the same or different. )
The step of adding a hydrophilic organic solvent (C) containing no nitrogen atoms to a solution of the polysilsesquioxane (A) in the hydrophobic organic solvent (B) and removing the precipitate is carried out one or more times. 2. The method for producing a polysilsesquioxane according to item 1, comprising the step of reducing the turbidity of the methyl isobutyl ketone solution containing 71% by mass of the polysilsesquioxane (A) to 50 FTU or less,
The hydrophobic organic solvent (B) is at least one selected from the group consisting of alkyl acetates having 3 to 8 carbon atoms, aliphatic ketones having 4 to 8 carbon atoms, toluene, xylene, and mesitylene,
The production method, wherein the hydrophilic organic solvent (C) is at least one selected from the group consisting of alcohols having 1 to 3 carbon atoms and acetone.
Item 5 The polysilsesquioxane according to Item 1 above has a silicon-containing bonding unit T ³ (where T ³ is a silicon-bonded silicon-bonded unit containing all three oxygen atoms bonded to other silicon atoms. 5. The method for producing a polysilsesquioxane according to item 4, wherein the content of silicon-bonded units) is 60 mol % or more.
Item 6. The method for producing a polysilsesquioxane according to Item 4 or 5 above, wherein the precipitate is removed by filtration through a depth filter.
Item 7 The polysilsesquioxane (A) has the following general formula (2):
RSi(OX) ₃ (2)
(Wherein, X represents an alkyl group having 1 to 5 carbon atoms, and R represents a linear alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. show.)
or a compound represented by the following general formula (3):
R'Si(OX) ₃ (3)
(In the formula, X has the same meaning as above, and R' represents fluoro (alkyl group having 1 to 4 carbon atoms).)
7. The polysilsesquioxy according to any one of the above items 4 to 6, which is obtained by a hydrolysis polycondensate of a mixture with a compound represented by or a step of purifying the hydrolysis polycondensate. Sun manufacturing method.
Item 8. The method for producing a polysilsesquioxane according to Item 7, wherein the purification step is at least one of the following steps [1] and [2].
Step [1]: A step of filtering fine particles in the reaction mixture containing the hydrolyzed polycondensate.
Step [2]: A step of separating and washing the organic solvent phase containing the hydrolyzed polycondensate with an aqueous phase, and filtering fine particles in the organic solvent phase.
Item 9 The hydrolytic polycondensate is obtained by hydrolyzing the compound represented by the general formula (2) or a mixture of the compound and the compound represented by the general formula (3) in the absence of a base. 9. The method for producing a polysilsesquioxane according to item 7 or 8, which is obtained by polycondensing.

INDUSTRIAL APPLICABILITY The present invention can provide a method capable of producing a polysilsesquioxane having a turbidity of 50 FTU or less and high storage stability. The polysilsesquioxane produced by the method of the present invention has low turbidity and excellent storage stability. When used for electronic members, the sublimation component is reduced and contact failure can be suppressed.

The present invention will be described in detail below.
1. Polysilsesquioxane
The present invention provides a polysilsesquioxane represented by the following general formula (1), wherein a methyl isobutyl ketone solution containing 71% by mass of the polysilsesquioxane has a turbidity of 50 FTU or less. Oxane.

[RSiO _1.5 ] _m [R'SiO _1.5 ] _n (1)
(Wherein, R, R', m and n represent the same meanings as above.)

Linear alkyl groups having 1 to 4 carbon atoms include methyl, ethyl, n-propyl and n-butyl, with methyl and ethyl being preferred.

Examples of aryl groups having 6 to 10 carbon atoms include phenyl and naphthyl, with phenyl being preferred.

Aralkyl groups having 7 to 10 carbon atoms include benzyl, phenylethyl, phenylpropyl, phenylbutyl and the like, with benzyl being preferred.

R is preferably a linear alkyl group having 1 to 4 carbon atoms, more preferably methyl or ethyl.

Fluoro (alkyl group having 1 to 4 carbon atoms) means an alkyl group having 1 to 4 carbon atoms substituted with one or more fluoro groups. Specific examples of fluoro (alkyl group having 1 to 4 carbon atoms) include monofluoromethyl, difluoromethyl, trifluoromethyl, monofluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, pentafluoroethyl, monofluoropropyl, 3,3-difluoropropyl, 3,3,3-trifluoropropyl, heptafluoropropyl, monofluorobutyl, 4,4-difluorobutyl, 4,4,4-trifluorobutyl, nonafluorobutyl and the like, with trifluoromethyl, 2,2,2-trifluoroethyl and 3,3,3-trifluoropropyl being preferred.

Acryloxy (alkyl group having 1 to 4 carbon atoms) means an alkyl group having 1 to 4 carbon atoms substituted with an acryloxy group. Acryloxy (alkyl group having 1 to 4 carbon atoms) specifically includes acryloxymethyl, 2-acryloxyethyl, 3-acryloxypropyl, and 4-acryloxybutyl, 3-acryloxypropyl, and 4-acryloxybutyl are preferred.

Methacryloxy (alkyl group having 1 to 4 carbon atoms) means an alkyl group having 1 to 4 carbon atoms substituted with a methacryloxy group. Methacryloxy (alkyl group having 1 to 4 carbon atoms) specifically includes methacryloxymethyl, 2-methacryloxyethyl, 3-methacryloxypropyl, and 4-methacryloxybutyl, 3-methacryloxypropyl, and 4-methacryloxybutyl are preferred.

Glycidyloxy (alkyl group having 1 to 4 carbon atoms) means an alkyl group having 1 to 4 carbon atoms substituted with a glycidyloxy group. Specific examples of glycidyloxy (alkyl group having 1 to 4 carbon atoms) include glycidyloxymethyl, 2-glycidyloxyethyl, 3-glycidyloxypropyl, 4-glycidyloxybutyl, and 3-glycidyloxyisobutyl. , 3-glycidyloxypropyl are preferred.

Epoxycyclohexyl (alkyl group having 1 to 4 carbon atoms) is an alkyl group having 1 to 4 carbon atoms substituted with an epoxycyclohexyl group. Specific examples of epoxycyclohexyl (alkyl group having 1 to 4 carbon atoms) include 2-(3,4-epoxycyclohexyl)ethyl, 3-(3,4-epoxycyclohexyl)propyl, and 4-(3,4 -epoxycyclohexyl)butyl, preferably 2-(3,4-epoxycyclohexyl)ethyl.

R' is preferably trifluoromethyl, 3,3,3-trifluoropropyl, 3-acryloxypropyl, 3-methacryloxypropyl, and 2-(3,4-epoxycyclohexyl)ethyl.

m is an integer of 5 to 100,000, preferably an integer of 6 to 10,000.

n is an integer of 0 to 100,000, preferably an integer of 1 to 10,000.

m R's and n R's (when n is 2 or more) may be the same or different.

The turbidity of the methyl isobutyl ketone solution containing 71% by mass of the polysilsesquioxane is 50 FTU or less, preferably 44 FTU or less, more preferably 35 FTU or less. The polysilsesquioxane of the present invention is characterized by having a turbidity of 50 FTU or less. Since the polysilsesquioxane of the present invention has a low turbidity of 50 FTU or less, it can improve the light transmittance when used for optical members, and when used for electronic members, A sublimation component is reduced, and contact failure can be suppressed. In addition, since the polysilsesquioxane of the present invention has a turbidity of 50 FTU or less, it has higher storage stability than a polysilsesquioxane with a turbidity exceeding 50 FTU.

As used herein, turbidity is based on the transmitted light turbidity in JIS K 0101 "industrial water test method", put the polysilsesquioxane solution in a 50 mm cell, degassed, and measured the transmitted light intensity at 660 nm. is measured with an ultraviolet/visible spectrometer, and a value (FTU, formazin turbidity) calculated from a calibration curve prepared using a formazin standard solution.

Silicon-containing bonding unit T ³ in the polysilsesquioxane of the present invention (here, T ³ is a silicon-containing bonding unit in which all three oxygen atoms bonded to a silicon atom are bonded to other silicon atoms) is preferably 60 mol % or more, more preferably 65 mol % or more. When the content of the silicon ^- containing bonding unit T3 is 60 mol% or more, gelation does not occur and reproducibility is good.

The polysilsesquioxane of the present invention preferably has a polystyrene equivalent weight average molecular weight of 2,000 to 100,000, more preferably 2,500 to 50,000. When the weight average molecular weight is within the above range, the PSQ of the present invention does not gel and has good reproducibility.

The polystyrene-equivalent weight average molecular weight of polysilsesquioxane is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

2. Method for producing polysilsesquioxane The method for producing the above-described polysilsesquioxane comprises the following general formula (1):
[RSiO _1.5 ] _m [R'SiO _1.5 ] _n (1)
(Wherein, R, R', m, and n have the same meanings as above.)
The step of adding a hydrophilic organic solvent (C) containing no nitrogen atoms to a solution of the polysilsesquioxane (A) in the hydrophobic organic solvent (B) and removing the precipitate is carried out one or more times. and reducing the turbidity of the methyl isobutyl ketone solution containing 71% by mass of polysilsesquioxane (A) to 50 FTU or less.

The method for producing the polysilsesquioxane (A) is not particularly limited, and it can be produced using a conventionally known method.

The polysilsesquioxane (A) has the following general formula (2):
RSi(OX) ₃ (2)
(Wherein, X represents an alkyl group having 1 to 5 carbon atoms, and R has the same meaning as above.)
or a compound represented by the following general formula (3):
R'Si(OX) ₃ (3)
(Wherein, X and R' have the same meanings as above.)
It is preferably obtained by a hydrolysis polycondensate of a mixture with a compound represented by or a step of purifying the hydrolysis polycondensate.

The hydrolytic polycondensate is a compound represented by the general formula (2) (hereinafter sometimes referred to as "compound (2)"), or the compound (2) and the general formula (3). can be produced by hydrolyzing and polycondensing a mixture (collectively referred to as "silane raw material") with a compound (hereinafter sometimes referred to as "compound (3)"). Hydrolysis and polycondensation are preferably carried out in the absence of bases. Moreover, this reaction is preferably carried out by heating the silane raw material and water in a solvent.

In formulas (2) and (3), examples of the alkyl group having 1 to 5 carbon atoms for X include a linear alkyl group having 1 to 5 carbon atoms and a branched alkyl group having 3 to 5 carbon atoms. Linear alkyl groups having 1 to 5 carbon atoms include methyl, ethyl, n-propyl, n-butyl, and n-pentyl. Branched alkyl groups having 3 to 5 carbon atoms include isopropyl, isobutyl, tert-butyl, isopentyl and the like. Preferred alkyl groups having 1 to 5 carbon atoms are methyl, ethyl and n-propyl, and more preferred are methyl and ethyl. Three X's may be the same or different.

Examples of compound (2) include methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltriisopropoxysilane. Examples include silanes, and methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, and ethyltriethoxysilane are preferred.

Examples of compound (3) include trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, 2,2,2-trifluoroethyltrimethoxysilane, 2,2,2-trifluoroethyltriethoxysilane, 3, 3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane , 3-methacryloxypropyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4- epoxycyclohexyl)ethyltriethoxysilane and the like, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3- Methacryloxypropyltriethoxysilane is preferred.

When a mixture of compound (2) and compound (3) is used as the silane raw material, compound (2) and compound (3) should be mixed at a molar ratio of 99:1 to 1:99. is preferred, and 90:1 to 1:1 is more preferred.

A catalyst is preferably present in the reaction system. An acidic catalyst is preferred as the catalyst. Acidic catalysts include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and boric acid; of organic acids. The amount of the acidic catalyst to be used is preferably about 0.1 to 50 mol %, more preferably about 0.1 to 20 mol %, relative to 1 mol of the silane raw material.

Hydrolysis and polycondensation of the silane raw material are preferably carried out in a solvent containing water. As the solvent, a hydrophilic organic solvent is preferable. As the hydrophilic organic solvent, an alcohol solvent is more preferable. Alcohol solvents include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-ethoxyethanol, 4-methyl-2-pentanol, 2- butoxyethanol and the like. Among these, alcoholic solvents having 1 to 4 carbon atoms such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-butanol are preferred from the viewpoint of uniform solubility of the oligomer in the solvent.

The hydrolysis of the silane raw material can be performed, for example, by introducing the silane raw material into the solution by dropping or the like while stirring a solution containing an acidic catalyst, water and an alcoholic solvent.

The concentration of the silane raw material during hydrolysis and polycondensation is preferably about 5 to 80% by mass, more preferably about 10 to 50% by mass. By setting the concentration of the silane raw material within the above range, the generation of impurities such as polyhedral compounds is reduced, the molecular weight can be more easily controlled, and the reaction can proceed with high volumetric efficiency.

As for the reaction temperature, the reaction can be performed at room temperature when a catalyst is present. Usually, a suitable temperature from 20 to 80° C. can be adopted depending on the purpose. The reaction time is usually 0.05 to 24 hours, preferably 0.1 to 8 hours.

Polycondensation can be carried out with or without an acid catalyst.

As the acidic catalyst, the same acidic catalyst as used for hydrolysis can be used. It is preferable to use the same acidic catalyst as the acidic catalyst used during hydrolysis. An acidic catalyst may be added during the polycondensation.

Also, the polycondensation reaction proceeds without using a catalyst. It is preferable to wash the solution obtained by hydrolyzing the silane raw material with a ketone solvent or a mixed solvent of an ester solvent and water until it becomes neutral, and then carry out polycondensation.

Ketone solvents include, for example, methyl isobutyl ketone, methyl amyl ketone, and the like.

Ester solvents include, for example, ethyl acetate, n-propyl acetate, n-butyl acetate, propylene glycol monomethyl ether acetate and the like.

The concentration of the silane raw material during polycondensation is about 5 to 80% by mass, preferably about 10 to 60% by mass.

By setting the concentration of the silane raw material at the time of polycondensation within the above range, it is possible to obtain an appropriate viscosity that is easy to handle, to prevent gelation, and to have a high volumetric efficiency, which is practical.

The polycondensation temperature is usually 40 to 200°C, preferably 70 to 160°C. The polycondensation time is usually 0.1 to 72 hours, preferably 0.5 to 24 hours.

When R' contains a carbon-carbon double bond or an epoxy group, additives may be added during hydrolysis and polycondensation. Examples of additives include antioxidants and the like.

The antioxidant is not particularly limited, and examples thereof include monophenols such as 2,6-di-t-butyl-p-cresol, dibutylhydroxytoluene, and 2,6-di-t-butyl-p-ethylphenol. compounds can be used. These can be used singly or in combination of two or more.

When the antioxidant is used, the blending amount is preferably 0.01 to 30 mol %, more preferably 0.05 to 20 mol %, relative to the silane raw material containing R'.

The obtained hydrolyzed polycondensate can be used as polysilsesquioxane (A) as it is. Alternatively, a product obtained by purifying the hydrolyzed polycondensate may be used as the polysilsesquioxane (A).

As a step of purifying the hydrolytic polycondensate, a step of filtering fine particles in a reaction mixture containing the hydrolytic polycondensate (step [1]), and an organic solvent phase containing the hydrolytic polycondensate A step of separating and washing with an aqueous phase and filtering fine particles in an organic solvent phase (step [2]) can be mentioned. Either one of these steps may be performed, or both of them may be performed. As the purification treatment, both steps [1] and [2] are preferably performed, and in this case, step [1] and step [2] are preferably performed in this order.

Filtration of fine particles in step [1] is preferably carried out with filter paper or filter cloth.

The organic solvent used in step [2] can be appropriately selected according to the type and amount of silane raw material used. Examples of organic solvents include ester solvents such as methyl acetate, ethyl acetate, n-propyl acetate and n-butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and methyl amyl ketone; methanol, ethanol, 2- alcoholic solvents such as propanol, 1-butanol and 2-butanol; and water. These solvents can be used singly or in combination of two or more.

Filtration of fine particles in step [2] is preferably carried out with filter paper or filter cloth.

Polysilsesquioxane (A) obtained by the production method described above is dissolved in a hydrophobic organic solvent (B) to prepare a solution of polysilsesquioxane (A) in the hydrophobic organic solvent (B). .

Examples of the hydrophobic organic solvent (B) include alkyl acetates having 3 to 8 carbon atoms, aliphatic ketones having 4 to 8 carbon atoms, toluene, xylene, and mesitylene.

Examples of alkyl acetates having 3 to 8 carbon atoms include methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, neopentyl acetate, and acetic acid. and n-hexyl.

Examples of aliphatic ketones having 4 to 8 carbon atoms include methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, diethyl ketone, ethyl n-propyl ketone, di(n-propyl) ketone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone and the like.

As the hydrophobic organic solvent (B), methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, n-propyl acetate, and n-butyl acetate are preferred.

The hydrophobic organic solvent (B) can be used alone or in combination of two or more.

The amount of the hydrophobic organic solvent (B) used is preferably 0.1 to 50 times by mass, more preferably 0.2 to 40 times by mass, that of the polysilsesquioxane (A).

A hydrophilic organic solvent (C) containing no nitrogen atoms is added to a solution of polysilsesquioxane (A) in a hydrophobic organic solvent (B). As a result, by-products such as polyhedral polysilsesquioxane are precipitated. If a hydrophilic organic solvent containing nitrogen atoms is used, the precipitate may become unfilterable.

As the hydrophilic organic solvent (C), alcohols having 1 to 3 carbon atoms (methanol, ethanol, 1-propanol, 2-propanol, etc.), acetone, and the like can be used. As the hydrophilic organic solvent (C), alcohols having 2 to 3 carbon atoms and acetone are preferable, and ethanol and 2-propanol are more preferable.

The said hydrophilic organic solvent (C) can be used individually by 1 type or in mixture of 2 or more types.

The amount of the hydrophilic organic solvent (C) used is preferably 0.3 to 30 times by mass, more preferably 0.5 to 20 times by mass, that of the polysilsesquioxane (A).

The step of removing precipitates is performed one or more times. This process is repeated until the turbidity of the methyl isobutyl ketone solution containing 71% by mass of polysilsesquioxane (A) is 50 FTU or less.

Removal of precipitates is preferably carried out by filtration through a depth filter. Impurities such as polyhedral PSQ can be efficiently removed by using a depth filter.

The depth filter (depth filtration filter, microfiltration filter) used in the present invention is a filter that captures solid particles not only on the surface of the filter medium but also inside the filter medium. Any filter may be employed as long as it has such properties. As such a depth filter, more specifically, a filter using a filter medium made of a porous membrane or a hollow fiber resin material can be used. Such filters are readily available commercially. Specific examples include filters using membranes made of resin materials such as cellulose, polyethersulfone, cellulose acetate, polypropylene, tetrafluoroethylene, polyethylene, nylon (registered trademark), or hollow fibers as filter media.

According to the method of the present invention, a polysilsesquioxane having a turbidity of 50 FTU or less and high storage stability can be produced. The polysilsesquioxane produced by the method of the present invention has low turbidity and excellent storage stability. When used for electronic members, the sublimation component is reduced and contact failure can be suppressed.

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the scope of the present invention is not limited by these examples. In addition, Example 8 is a reference example.

The weight average molecular weight (Mw) in Examples and Comparative Examples was determined by GPC. The abundance ratio of T ¹ to T ³ was obtained from the peak area ratio of ²⁹ Si-NMR. Each measurement condition is as follows.

[GPC conditions]
Column: TSKgel G2000H _XL & TSKgel G4000H _XL (manufactured by Tosoh Corporation)
Column temperature: 40°C
Mobile phase: Tetrahydrofuran (THF)
Flow rate: 0.65mL/min
Detector: RI
Reference material: polystyrene

[ ²⁹ Si-NMR conditions]
Resonance frequency: 79.5MHz
Measurement temperature: room temperature Reagents: deuterated acetone containing Cr(acac) ₃ as relaxation agent.
In addition, the chemical shifts of ²⁹ Si-NMR derived from each T structure are as follows.
⁽ T1 ^- T3)
T ³ : -61 to -71 ppm
T2: ^-51 to -61 ppm
T ¹ : -45 to -51 ppm

[Turbidity measurement conditions]
As used herein, turbidity is based on the transmitted light turbidity in JIS K 0101 "industrial water test method", put the polysilsesquioxane solution in a 50 mm cell, degassed, and measured the transmitted light intensity at 660 nm. is measured with an ultraviolet/visible spectrometer, and a value (FTU, formazin turbidity) calculated from a calibration curve prepared using a formazin standard solution.

In addition, as a solution storage stability test, a methyl isobutyl ketone solution containing 71% by mass of polysilsesquioxane was allowed to stand at -20 ° C. for 10 days to 1 year, then the turbidity was measured, and the solution was left at -20 ° C. The turbidity difference before and after placement was evaluated. Acceptance criteria for turbidity difference evaluation are 10 degrees or less in 10 days, 30 degrees or less in 1 month, and 50 degrees or less in 1 year.

[Depth filter]
As a depth filter, Betapure (registered trademark, filtration accuracy = 0.5 µm; material = polypropylene) manufactured by 3M Japan Limited was used.

[Solid content measurement conditions]
The solid content was obtained from the mass concentration measured using an infrared moisture meter FD-800 (manufactured by Kett Scientific Laboratory Co., Ltd.).

[Example 1-1]
A 300 mL four-necked flask was charged with 25.0 g of ion-exchanged water, 93.6 g of 2-propanol (manufactured by Kanto Kagaku Co., Ltd.), and 0.2 g of 35% hydrochloric acid (manufactured by Sigma-Aldrich), and methyltriethoxysilane ( Shin-Etsu Chemical Co., Ltd.) 75.1 g (0.42 mol) was added dropwise at 25° C. over 2 hours. The mixture was heated to 40°C and stirred at 40°C for 3 hours. The Mw of the resulting oligomer was 1,200. 6.6 g of ion-exchanged water and 1.1 g of 35% hydrochloric acid were added to the resulting oligomer solution, and the mixture was heated to 79° C. and stirred at 79° C. for 12 hours. After the resulting mixture was filtered through a filter paper with a filtration accuracy of 1 μm, 169 g of n-propyl acetate (manufactured by Kanto Kagaku Co., Ltd.)/169 g of ion-exchanged water were added to the filtrate for liquid separation and washing. The n-propyl acetate phase was washed with 169 g of ion-exchanged water until the pH reached 4 or more, and filtered through a filter paper with a filtration accuracy of 1 μm to obtain 141.3 g of an n-propyl acetate solution. The solid content of the obtained solution was 19% by mass. The Mw of the product was 9,100.

[Example 1-2]
9.9 g of methyl isobutyl ketone (manufactured by Kanto Kagaku Co., Ltd.) was added to 141.3 g of the solution obtained in Example 1-1, and the mixture was concentrated under reduced pressure to give a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 69% by mass. 4 g was obtained. 28.2 g of 2-propanol was added to 38.4 g of the obtained solution, and the mixture was stirred at 25° C. for 1 hour to obtain 66.6 g of a solution with a turbidity of 147 FTU. 66.6 g of the resulting solution was passed through a depth filter to remove precipitates, yielding 62.4 g of a solution with a turbidity of 5 FTU. 62.4 g of this solution was concentrated under reduced pressure to obtain 33.9 g of a methyl isobutyl ketone solution having a turbidity of 57 FTU and a polysilsesquioxane concentration of 71% by mass.

[Example 1-3]
25.3 g of 2-propanol was added to 33.9 g of the methyl isobutyl ketone solution obtained in Example 1-2, and the mixture was stirred at 25° C. for 1 hour to obtain 59.2 g of a solution with a turbidity of 137 FTU. The resulting solution was passed through a depth filter to remove precipitates, yielding 54.9 g of a solution with a turbidity of 0 FTU. This solution was concentrated under reduced pressure to obtain 30.0 g of a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 71% by mass.

[Example 2-1]
A 200 mL four-necked flask was charged with 11.8 g of ion-exchanged water, 44.4 g of 2-propanol, and 0.1 g of 35% hydrochloric acid. It dripped over time. The mixture was heated to 40°C and stirred at 40°C for 3 hours. The Mw of the resulting oligomer was 1,200. 3.1 g of ion-exchanged water and 0.5 g of 35% hydrochloric acid were added to the resulting oligomer solution, and the mixture was heated to 79° C. and stirred at 79° C. for 14 hours. After the resulting mixture was filtered through a filter paper with a filtration accuracy of 1 μm, 80 g of n-propyl acetate/80 g of ion-exchanged water were added to the filtrate, and the mixture was separated and washed. The n-propyl acetate phase was washed with 80 g of ion-exchanged water until the pH reached 4 or more, and filtered through a filter paper with a filtration accuracy of 1 μm to obtain 66.1 g of an n-propyl acetate solution. The solid content of the obtained solution was 19% by mass. The Mw of the product was 9,300.

[Example 2-2]
After adding 4.5 g of methyl isobutyl ketone to 66.1 g of the solution obtained in Example 2-1, the mixture was concentrated under reduced pressure to obtain 17.9 g of methyl isobutyl ketone solution having a polysilsesquioxane concentration of 70% by mass. 13.3 g of 2-propanol was added to this solution and stirred at 25° C. for 1 hour to obtain 31.2 g of a solution with a turbidity of 357 FTU. The resulting solution was passed through a depth filter to remove precipitates, yielding 28.9 g of a solution with a turbidity of 1 FTU. After that, this solution was concentrated under reduced pressure to obtain 14.6 g of a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 71% by mass.

[Example 3]
By performing the same operation as in Example 2-1, 66.2 g of n-propyl acetate solution was obtained. The solid content of the obtained solution was 19% by mass. The Mw of the product was 9,500. Thereafter, the same operation as in Example 2-2 was performed to obtain 14.8 g of a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 71% by mass.

[Example 4]
By performing the same operation as in Example 2-1, 65.9 g of n-propyl acetate solution was obtained. The solid content of the obtained solution was 19% by mass. The Mw of the product was 9,100. After that, the same operation was performed except that ethanol (manufactured by Kanto Kagaku Co., Ltd.) was used instead of 2-propanol in Example 2-2, and 15.5 g of a methyl isobutyl ketone solution with a polysilsesquioxane concentration of 71% by mass was obtained. got

[Example 5]
By performing the same operation as in Example 2-1, 65.9 g of n-propyl acetate solution was obtained. The solid content of the obtained solution was 19% by mass. The Mw of the product was 9,100. After that, the same operation was performed except that acetone (manufactured by Kanto Kagaku Co., Ltd.) was used instead of 2-propanol in Example 2-2, and 15.0 g of a methyl isobutyl ketone solution with a polysilsesquioxane concentration of 71% by mass was obtained. got

[Example 6]
By performing the same operation as in Example 2-1, 65.9 g of n-propyl acetate solution was obtained. The solid content of the obtained solution was 19% by mass. The Mw of the product was 9,100. After that, the same operation was performed except that methanol (manufactured by Kanto Kagaku Co., Ltd.) was used instead of 2-propanol in Example 2-2, and 15.2 g of a methyl isobutyl ketone solution with a polysilsesquioxane concentration of 71% by mass was obtained. got

[Example 7]
A 300 mL four-necked flask was charged with 25.5 g of ion-exchanged water, 96.6 g of 2-propanol, and 0.44 g of 35% hydrochloric acid. It dripped over time. The mixture was stirred at 60° C. for 4 hours and then at 80° C. for 7 hours. The mixed solution was cooled and filtered through a filter paper with a filtration accuracy of 1 μm, and then 140.2 g of n-propyl acetate/174.3 g of ion-exchanged water were added to the filtrate to separate and wash. The n-propyl acetate phase was washed with 174.3 g of ion-exchanged water until the pH reached 4 or higher, and filtered through a filter paper with a filtration accuracy of 1 μm to obtain 98.2 g of an n-propyl acetate solution. The solid content of the obtained solution was 27% by mass. The Mw of the product was 2,800.

11.4 g of methyl isobutyl ketone was added to 98.2 g of the resulting solution and concentrated under reduced pressure to obtain 37.9 g of a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 70% by mass. 28.4 g of 2-propanol was added to this solution and stirred at 25° C. for 1 hour to obtain 66.3 g of a solution with a turbidity of 100 FTU. The resulting solution was passed through a depth filter to remove precipitates, yielding 64.9 g of a solution with a turbidity of 0 FTU. After that, this solution was concentrated under reduced pressure to obtain 35.4 g of a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 71% by mass.

[Example 8]
In a 100 mL four-necked flask, 40.3 g (226 mmol) of methyltriethoxysilane, 14.0 g (56 mmol) of 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), and butylhydroxytoluene (BHT) ( To a solution of 0.12 g (0.6 mmol) manufactured by Tokyo Chemical Industry Co., Ltd.), 15.3 g of 0.3% by mass hydrochloric acid was added dropwise over 1 hour, then the temperature was raised to 74° C. and the mixture was stirred for 14 hours. 77 g of n-propyl acetate/67 g of ion-exchanged water were added to the mixed solution, and the mixture was separated and washed. The n-propyl acetate phase was washed with 67 g of ion-exchanged water until the pH reached 4 or higher, and filtered through a filter paper with a filtration accuracy of 1 μm to obtain 105.0 g of an n-propyl acetate solution. The solid content of the obtained solution was 24% by mass. Mw was 9,800.

9.9 g of methyl isobutyl ketone was added to 105.0 g of this solution and concentrated under reduced pressure to obtain 36.0 g of a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 70% by mass. 27.0 g of 2-propanol was added to this solution and stirred at 25° C. for 1 hour to obtain 63.0 g of a solution with a turbidity of 110 FTU. The resulting solution was passed through a depth filter to remove precipitates, yielding 60.5 g of a solution with a turbidity of 0 FTU. This solution was concentrated under reduced pressure to obtain 34.1 g of a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 71% by mass.

[Example 9]
By performing the same operation as in Example 2-1, 66.0 g of n-propyl acetate solution was obtained. The solid content of the obtained solution was 18% by mass. The Mw of the product was 20,000. Thereafter, the same operation as in Example 2-2 was performed to obtain 15.1 g of a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 71% by mass.

[Comparative Example 1]
By performing the same operation as in Example 2-1, 66.1 g of n-propyl acetate solution was obtained. The solid content of the obtained solution was 19% by mass. The Mw of the product was 9,300. After adding 5.2 g of methyl isobutyl ketone to 66.1 g of this solution, the mixture was concentrated under reduced pressure to obtain 17.7 g of a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 71% by mass.

[Comparative Example 2]
The same operation as in Example 2-1 was performed to obtain 65.9 g of solution. The solid content of the obtained solution was 19% by mass. The Mw of the product was 9,100. After adding 5.1 g of methyl isobutyl ketone to this solution, the solution was concentrated under reduced pressure to obtain 17.6 g of a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 71% by mass. 13.6 g of acetonitrile (manufactured by Kanto Kagaku Co., Ltd.) was added to the resulting solution, and the mixture was stirred at 25°C for 1 hour and allowed to stand at 25°C for 24 hours. Therefore, each analysis and storage stability test were not performed.

[Comparative Example 3]
By performing the same operation as in Example 1-1, 143.8 g of n-propyl acetate solution was obtained. The solid content of the obtained solution was 19% by mass. The Mw of the product was 9,300. Thereafter, the same operation was performed except that acetone was used instead of 2-propanol in Example 1-2 to obtain 34.3 g of a methyl isobutyl ketone solution having a polysilsesquioxane concentration of 71% by mass.

Table 1 shows the T3 structure ratio, Mw, and turbidity of the polysilsesquioxane solutions obtained in Examples 1 to 9 and Comparative Examples 1 and ³ . Table 1 shows the turbidity of the polysilsesquioxane solutions obtained in Examples 1-3, 2-2, 3 to 9, and Comparative Examples 1 and 3 after standing at -20°C.

Claims (9)

Turbidity of a methyl isobutyl ketone solution containing 71% by mass of a polysilsesquioxane having a random structure represented by the following general formula (1) and containing 71% by mass of the polysilsesquioxane polysilsesquioxanes having a degree of 50 FTU or less.
[RSiO _1.5 ] _m [R'SiO _1.5 ] _n (1)
(In the formula, R represents a linear alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms.
R' represents fluoro (alkyl group having 1 to 4 carbon atoms).
m represents an integer of 5 to 100,000, and n represents an integer of 0 to 100,000.
m R's and n R's (when n is 2 or more) may be the same or different. ) The content of silicon-containing bonding units T ³ (here, T ³ is a silicon-containing bonding unit in which all three oxygen atoms bonded to a silicon atom are bonded to other silicon atoms) is 60 mol% or more. The polysilsesquioxane of claim 1. 3. The polysilsesquioxane according to claim 1, which has a polystyrene-equivalent weight average molecular weight of 2,000 to 100,000. The following general formula (1):
[RSiO _1.5 ] _m [R'SiO _1.5 ] _n (1)
(In the formula, R represents a linear alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms.
R' represents fluoro (alkyl group having 1 to 4 carbon atoms).
m represents an integer of 5 to 100,000, and n represents an integer of 0 to 100,000.
m R's and n R's (when n is 2 or more) may be the same or different. )
The step of adding a hydrophilic organic solvent (C) containing no nitrogen atoms to a solution of the polysilsesquioxane (A) in the hydrophobic organic solvent (B) and removing the precipitate is carried out one or more times. The method for producing the polysilsesquioxane according to claim 1, comprising the step of reducing the turbidity of the methyl isobutyl ketone solution containing 71% by mass of the polysilsesquioxane (A) to 50 FTU or less,
The hydrophobic organic solvent (B) is at least one selected from the group consisting of alkyl acetates having 3 to 8 carbon atoms, aliphatic ketones having 4 to 8 carbon atoms, toluene, xylene, and mesitylene,
The production method, wherein the hydrophilic organic solvent (C) is at least one selected from the group consisting of alcohols having 1 to 3 carbon atoms and acetone. The polysilsesquioxane according to claim 1 is a silicon-containing bond unit T ³ (here, T ³ is a silicon-containing bond in which all three oxygen atoms bonded to a silicon atom are bonded to other silicon atoms unit) content is 60 mol% or more, the method for producing a polysilsesquioxane according to claim 4. 6. The method for producing a polysilsesquioxane according to claim 4 or 5, wherein the removal of precipitates is performed by filtration through a depth filter. The polysilsesquioxane (A) has the following general formula (2):
RSi(OX) ₃ (2)
(Wherein, X represents an alkyl group having 1 to 5 carbon atoms, and R represents a linear alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. show.)
or a compound represented by the following general formula (3):
R'Si(OX) ₃ (3)
(In the formula, X has the same meaning as above, and R' represents fluoro (alkyl group having 1 to 4 carbon atoms).)
Polysilsesquioxy according to any one of claims 4 to 6, which is obtained by a hydrolysis polycondensate of a mixture with a compound represented by, or a step of purifying the hydrolysis polycondensate. Sun manufacturing method. 8. The method for producing a polysilsesquioxane according to claim 7, wherein the purification step is at least one of the following steps [1] and [2].
Step [1]: A step of filtering fine particles in the reaction mixture containing the hydrolyzed polycondensate.
Step [2]: A step of separating and washing the organic solvent phase containing the hydrolyzed polycondensate with an aqueous phase, and filtering fine particles in the organic solvent phase. The hydrolytic polycondensate is obtained by hydrolyzing and polymerizing the compound represented by the general formula (2) or a mixture of the compound and the compound represented by the general formula (3) in the absence of a base. 9. The method for producing the polysilsesquioxane according to claim 7 or 8, which is obtained by condensation.