Method for producing silicone polymer

Abstract

A production method for obtaining a stable silicone polymer is provided in which no washing step is necessary and, hence, a great improvement in yield is attained. The method for producing a silicone polymer comprises: hydrolyzing at least one silane compound selected from among compounds represented by the general formula RaSi(OR1)4-a (1) (wherein R represents a hydrogen atom or a monovalent organic group, R1 is a monovalent organic group, and a is an integer of 1-2) and compounds represented by the general formula Si(OR2)4 (2) (wherein R2 represents a monovalent organic group) in the presence of a quaternary ammonium compound and water; and thereafter bringing the resultant hydrolysate into contact with a cation-exchange resin.

Description

[Technical field]

[0001] The present invention relates to a method of preparation which significantly improves yields and results in a stable silicone polymer. [Background technology]

[0002] Silicone polymers are organic-inorganic hybrid materials in which organic and inorganic compounds are combined at the molecular level. They have been the subject of intensive research in recent years because they combine the properties of organic materials, such as flexibility and processability, with the properties of inorganic materials, such as heat resistance, weather resistance, and chemical resistance.

[0003] In particular, in pattern molding for manufacturing semiconductor elements, etc., it has been proposed to use a silicone polymer as a resist underlayer film when forming a reverse pattern using lithography technology, etching technology, etc. Silicone polymers that contain a large amount of structures derived from tetramethoxysilane or tetraethoxysilane in particular have been known to have excellent embedding properties in fine resist underlayer film patterns and excellent etching resistance when the resist underlayer film pattern is removed by oxygen-based gas etching, etc.

[0004] When a silicone polymer for use in a resist underlayer film is obtained from an alkoxysilane as a raw material, an acid or a base is generally used as a catalyst. It has been known that when a base, particularly a quaternary ammonium compound, is used as a catalyst, the silicone polymer is stable and the mechanical strength of the resulting film is excellent (see Patent Documents 1 to 3). These characteristics are thought to be related to the fact that, unlike acid catalysts and other base catalysts, quaternary ammonium compounds form ion pairs with silanol groups generated by hydrolysis of alkoxy groups to achieve equilibrium, and therefore tend to form a unique higher-order structure, for example, a cage structure (see Patent Documents 1 to 4).

[0005] On the other hand, when a silicone polymer is obtained using a quaternary ammonium compound as a catalyst, the quaternary ammonium compound needs to be neutralized and washed with water. In order to obtain a film by applying it to a substrate, the silicone polymer needs to contain a certain amount of silanol groups, which are condensation active groups. However, when a quaternary ammonium compound is used as a catalyst, it forms an ion pair with the silanol group, so it does not condense even if heated as it is. Therefore, it is necessary to neutralize the quaternary ammonium compound with an acid and remove salts and the like generated by neutralization by washing with water.

[0006] However, silicone polymers that contain many structures derived from tetramethoxysilane or tetraethoxysilane are highly polar and therefore easily dissolved in water, and even if they are washed with water, the water layer and the oil layer do not separate, and silicone polymers may not be obtained.In addition, even if the water layer and the oil layer are separated, the silicone polymer is distributed from the oil layer into the water layer and removed, so the yield of silicone polymers is extremely poor, and there is a problem that they cannot be used industrially.There has been a demand for a method of obtaining silicone polymers that contain many structures derived from tetramethoxysilane or tetraethoxysilane with good yield by using quaternary ammonium compounds as catalysts. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent No. 4530113 [Patent Document 2] Japanese Patent No. 6256775 [Patent Document 3] Japanese Patent Publication No. 2016-11411 [Patent Document 4] Japanese Patent No. 4409397 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a method for producing a silicone polymer which uses a quaternary ammonium compound as a catalyst, while at the same time significantly improving the yield and ensuring the stability of the resulting silicone polymer. [Means for solving the problem]

[0009] The method for producing a silicone polymer of the present invention comprises the steps of: R a Si(OR 1 ) 4-a ...(1) (Wherein, R is Methyl group or Ethyl group , R 1 teeth Methyl or ethyl group , a is 1 show.) and a compound represented by the following general formula (2): Si(OR 2 )4...(2) (In the formula, R 2 teeth Methyl or ethyl group (Indicates Selected from When the total amount of the compound represented by the general formula (1) and the compound represented by the general formula (2) is taken as 100 mol %, the compound represented by the general formula (2) is 50 to 100 mol %. The method is characterized in that a silane compound is hydrolyzed with a quaternary ammonium compound in the presence of water, and then contacted with a cation exchange resin. Effect of the Invention

[0010] In the method for producing a silicone polymer of the present invention, the reaction solution is contacted with a cation exchange resin to remove the quaternary ammonium compound, making neutralization with acid and washing with water unnecessary. As a result, the silicone polymer is not obtained due to the aqueous layer and the oil layer not being separated, and the silicone polymer is not distributed into the aqueous layer and removed, and the yield can be increased.

[0011] Furthermore, the method for producing a silicone polymer of the present invention can produce a polymer that does not gel and is soluble in organic solvents, and is highly stable and does not easily change in molecular weight.

[0012] When the silicone polymer produced by the method of the present invention is formed into a coating film, it is possible to obtain a hard coating film having a pencil hardness of at least 4H. A hard coating film has high scratch resistance.

[0013] The silicone polymer composition produced by the method for producing a silicone polymer of the present invention can be coated by a general coating method such as spin coating.In addition, when the silicone polymer composition produced by the method for producing a silicone polymer of the present invention is applied to a substrate, it can form a thin film on the substrate, and a thermosetting film can be formed on the substrate by applying heat.The thermosetting film thus formed has excellent properties of transparency and heat resistance, and can be used as a protective film for semiconductors and displays, a resist underlayer film, etc.

[0014] Furthermore, since the silicone polymer produced by the method for producing a silicone polymer of the present invention does not contain metal as a raw material, it can be suitably used in electronic information materials such as displays and semiconductors.

[0015] Furthermore, the silicone polymers obtained by using the method for producing a silicone polymer of the present invention are not limited to the field of electronic information materials, but can also be used in a wide range of fields, such as paints and adhesives. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The method for producing a silicone polymer of the present invention comprises the steps of: R a Si(OR 1 ) 4-a ...(1) (In the formula, R is a hydrogen atom or a monovalent organic group, R 1 represents a monovalent organic group, and a represents an integer of 1 to 2. and a compound represented by the general formula (2), Si(OR 2 )4...(2) (In the formula, R 2 represents a monovalent organic group. The method is characterized in that at least one silane compound selected from the group consisting of the above is hydrolyzed with a quaternary ammonium compound in the presence of water, and then contacted with a cation exchange resin.

[0017] In the above general formula (1), when R is a monovalent organic group, R and R 1 are independent of each other and may be the same or different organic groups. When a is 2, R are independent of each other and may be one type of monovalent organic group or two types of monovalent organic groups. Furthermore, when two or more R 1 are each independently one type of monovalent organic group or two or more types of monovalent organic groups. 1 Examples of the monovalent organic group include an alkyl group, an aryl group, a vinyl group, an allyl group, a glycidyl group, etc. In general formula (1), R is preferably a monovalent organic group, particularly an alkyl group or an aryl group.

[0018] Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms. These alkyl groups may be linear or branched, and further, hydrogen atoms may be substituted with fluorine atoms or the like.

[0019] Examples of the aryl group include a phenyl group, a naphthyl group, a methylphenyl group, an ethylphenyl group, a chlorophenyl group, a bromophenyl group, and a fluorophenyl group.

[0020] Specific examples of the compound represented by the general formula (1) include methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, methyltri-n-butoxysilane, methyltri-sec-butoxysilane, methyltri-tert-butoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltri-iso-propoxysilane, ethyltri-n-butoxysilane, and ethyltri-sec-butoxysilane. silane, ethyl tri-tert-butoxysilane, ethyl triphenoxysilane, vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tri-n-propoxysilane, vinyl tri-iso-propoxysilane, vinyl tri-n-butoxysilane, vinyl tri-sec-butoxysilane, vinyl tri-tert-butoxysilane, vinyl triphenoxysilane, n-propyl trimethoxysilane, n-propyl triethoxysilane, n-propyl tri-n-propoxysilane, n-propyl tri-iso-propoxysilane, n-propyl Tri-n-butoxysilane, n-propyl tri-sec-butoxysilane, n-propyl tri-tert-butoxysilane, n-propyl triphenoxysilane, i-propyl trimethoxysilane, i-propyl triethoxysilane, i-propyl tri-n-propoxysilane, i-propyl tri-iso-propoxysilane, i-propyl tri-n-butoxysilane, i-propyl tri-sec-butoxysilane, i-propyl tri-tert-butoxysilane, i-propyl triphenoxysilane, n-butyl trimethoxysilane, n-butyl n-butyltriethoxysilane, n-butyltri-n-propoxysilane, n-butyltri-iso-propoxysilane, n-butyltri-n-butoxysilane, n-butyltri-sec-butoxysilane, n-butyltri-tert-butoxysilane, n-butyltriphenoxysilane, sec-butyltrimethoxysilane, sec-butyltriethoxysilane, sec-butyltri-n-propoxysilane, sec-butyltri-iso-propoxysilane, sec-butyltri-n-butoxysilane, sec-butyltri-sec-butoxysilane,sec-Butyltri-tert-butoxysilane, sec-Butyltriphenoxysilane, t-Butyltrimethoxysilane, t-Butyltriethoxysilane, t-Butyltri-n-propoxysilane, t-Butyltri-iso-propoxysilane, t-Butyltri-n-butoxysilane, t-Butyltri-sec-butoxysilane, t-Butyltri-tert-butoxysilane, t-Butyltriphenoxysilane, Phenyltrimethoxysilane, Phenyltriethoxysilane, Phenyltri-n-propoxysilane, Phenyltri-iso-propoxy Sisilane, phenyltri-n-butoxysilane, phenyltri-sec-butoxysilane, phenyltri-tert-butoxysilane, phenyltriphenoxysilane, gamma-aminopropyltrimethoxysilane, gamma-aminopropyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxypropyltriethoxysilane, gamma-trifluoropropyltrimethoxysilane, gamma-trifluoropropyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyl-di-n-propoxysilane, dimethyl- Di-iso-propoxysilane, dimethyl-di-n-butoxysilane, dimethyl-di-sec-butoxysilane, dimethyl-di-tert-butoxysilane, dimethyldiphenoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyl-di-n-propoxysilane, diethyl-di-iso-propoxysilane, diethyl-di-n-butoxysilane, diethyl-di-sec-butoxysilane, diethyl-di-tert-butoxysilane, diethyldiphenoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxy Silane, di-n-propyl-di-n-propoxysilane, di-n-propyl-di-iso-propoxysilane, di-n-propyl-di-n-butoxysilane, di-n-propyl-di-sec-butoxysilane, di-n-propyl-di-tert-butoxysilane, di-n-propyl-di-phenoxysilane, di-iso-propyldimethoxysilane, di-iso-propyldiethoxysilane, di-iso-propyl-di-n-propoxysilane, di-iso-propyl-di-iso-propoxysilane, di-iso-propyl-di-n-butoxysilane,Di-isopropyl-di-sec-butoxysilane, di-isopropyl-di-tert-butoxysilane, di-isopropyl-di-phenoxysilane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-butyl-di-n-propoxysilane, di-n-butyl-di-isopropoxysilane, di-n-butyl-di-n-butoxysilane, di-n-butyl-di-sec-butoxysilane , di-n-butyl-di-tert-butoxysilane, di-n-butyl-di-phenoxysilane, di-sec-butyldimethoxysilane, di-sec-butyldiethoxysilane, di-sec-butyl-di-n-propoxysilane, di-sec-butyl-di-iso-propoxysilane, di-sec-butyl-di-n-butoxysilane, di-sec-butyl-di-sec-butoxysilane, di-sec-butyl-di-tert-bu di-toxysilane, di-sec-butyl-di-phenoxysilane, di-tert-butyldimethoxysilane, di-tert-butyldiethoxysilane, di-tert-butyl-di-n-propoxysilane, di-tert-butyl-di-iso-propoxysilane, di-tert-butyl-di-n-butoxysilane, di-tert-butyl-di-sec-butoxysilane, di-tert-butyl-di-tert-butoxysilane, di -tert-butyl-di-phenoxysilane, diphenyldimethoxysilane, diphenyl-di-ethoxysilane, diphenyl-di-n-propoxysilane, diphenyl-di-iso-propoxysilane, diphenyl-di-n-butoxysilane, diphenyl-di-sec-butoxysilane, diphenyl-di-tert-butoxysilane, diphenyldiphenoxysilane, and divinyltrimethoxysilane can be mentioned.

[0021] Preferred compounds as compound (1) are methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, etc., which are easily available industrially. These may be used alone or in combination of two or more kinds.

[0022] In the above general formula (2), R 2 The monovalent organic group represented by the formula (1) includes R and R 1 In addition, the four R 2 may be each independently one type of monovalent organic group, or two or more types of monovalent organic groups. Specific examples of the compound represented by general formula (2) include tetramethoxysilane, methoxytriethoxysilane, dimethoxydiethoxysilane, trimethoxyethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, and tetraphenoxysilane. Among these, tetramethoxysilane and tetraethoxysilane are preferred because they are easily available industrially.

[0023] In the method for producing a silicone polymer of the present invention, when the total amount of the compound represented by the general formula (1) and at least one silane compound selected from the compound represented by the general formula (2) is taken as 100 mol %, the compound represented by the general formula (2) is preferably 50 to 100 mol %, more preferably 60 to 100 mol %, and even more preferably 70 to 100 mol %. When the compound represented by the general formula (2) is 50 mol % or more, a hard coating film can be obtained, which is preferable.

[0024] In the method for producing a silicone polymer of the present invention, the reaction is carried out in the presence of a quaternary ammonium compound, which is preferably a quaternary ammonium compound containing a hydroxyl group.

[0025] Examples of the quaternary ammonium compound include hydroxymethyltrimethylammonium hydroxide, 1-hydroxyethyltrimethylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, 1-hydroxypropyltrimethylammonium hydroxide, 2-hydroxypropyltrimethylammonium hydroxide, 3-hydroxypropyltrimethylammonium hydroxide, hydroxymethyltriethylammonium hydroxide, 1-hydroxyethyltriethylammonium hydroxide, 2-hydroxyethyltriethylammonium hydroxide, 1-hydroxypropyltriethylammonium hydroxide, 2-hydroxypropyltriethylammonium hydroxide, 3-hydroxypropyltriethylammonium hydroxide, hydroxymethyltripropylammonium hydroxide, 1-hydroxyethyltripropylammonium hydroxide, 2-hydroxyethyltripropylammonium hydroxide, 1-hydroxypropyltripropylammonium hydroxide, 2-hydroxypropyltripropylammonium hydroxide, 2-hydroxypropyltripropylammonium hydroxide, 1-hydroxypropyltripropylammonium hydroxide, 2-hydroxypropyltripropylammonium hydroxide, 1-hydroxypropyltripropylammonium hydroxide, 2-hydroxypropyltripropylammonium hydroxide, 1-hydroxypropyltripropylammonium hydroxide, 2-hydroxypropyltripropylammonium hydroxide, 3-hydroxypropyltripropylammonium hydroxide, hydroxymethyltributylammonium hydroxide, 1-hydroxyethyltributylammonium hydroxide, 2-hydroxypropyltributylammonium hydroxide, 1-hydroxypropyltributylammonium hydroxide, 2-hydroxypropyltributylammonium hydroxide, 3-hydroxypropyltributylammonium hydroxide, dihydroxymethyldimethylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, tris(2-hydroxyethyl)methylammonium hydroxide, tetrabutylammonium fluoride, benzyltributylammonium chloride, benzyltriethylammonium chloride, benzyltrimethylammonium chloride, tetra-n-butylammonium chloride, tetraethylammonium chloride, tetramethylammonium chloride, benzyltri-n-butylammonium bromide, benzyltriethylammonium bromide, benzyltrimethylammonium bromide,Examples of the ammonium bromide include n-octyltrimethylammonium bromide, hexyltrimethylammonium bromide, tetrabutylammonium bromide, tetraethylammonium bromide, tetradecyltrimethylammonium bromide, tetramethylammonium bromide, tetra-n-propylammonium bromide, tetrabutylammonium iodide, tetraethylammonium iodide, tetramethylammonium iodide, tetra-n-propylammonium iodide, trimethylphenylammonium iodide, benzyltrimethylammonium hydroxide, phenyltrimethylammonium hydroxide, tetrabutylammonium hydroxide, tetraethylammonium hydroxide, tetramethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydrogen sulfate, tetrabutylammonium tetrafluoroborate, tetramethylammonium thiocyanate, and tetramethylammonium p-toluenesulfonate.

[0026] Among these, 2-hydroxyethyltrimethylammonium hydroxide, 2-hydroxytriethylammonium hydroxide, 2-hydroxymethyltripropylammonium hydroxide, 2-hydroxymethyltributylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, tris(2-hydroxyethyl)methylammonium hydroxide, benzyltributylammonium chloride, benzyltrimethylammonium chloride, tetra-n-butylammonium chloride, tetramethylammonium chloride, benzyltri-n-butylammonium bromide, benzyltrimethylammonium bromide, hexyltrimethylammonium bromide, tetrabutylammonium bromide, tetradecyltrimethylammonium bromide, and tetradecyltrimethylammonium bromide are preferred. ammonium bromide, tetramethylammonium bromide, benzyltrimethylammonium hydroxide, phenyltrimethylammonium hydroxide, tetrabutylammonium hydroxide, tetraethylammonium hydroxide, tetramethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydrogen sulfate, tetrabutylammonium tetrafluoroborate, tetramethylammonium thiocyanate, and tetramethylammonium p-toluenesulfonate are preferred, and tetramethylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, and tris(2-hydroxyethyl)methylammonium hydroxide are more preferred.Tetramethylammonium hydroxide is inexpensive and the reaction can be easily controlled, and 2-hydroxyethyltrimethylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, and tris(2-hydroxyethyl)methylammonium hydroxide are generally obtained by the addition reaction of trimethylamine, dimethylamine, and methylamine with ethylene oxide. Since no metals are used as raw materials, 2-hydroxyethyltrimethylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, and tris(2-hydroxyethyl)methylammonium hydroxide, which have low metal contents, are easily available in industrial grade and are preferred.

[0027] The amount of the quaternary ammonium compound used is preferably 0.002 to 2 moles, more preferably 0.005 to 1.0 mole, per mole of the total amount of alkoxyl groups of at least one silane compound selected from the compounds represented by the general formula (1) and the compounds represented by the general formula (2). By setting the amount of the quaternary ammonium compound to 0.002 to 2 moles per mole of the total amount of alkoxyl groups of the silane compound, a silicone polymer soluble in a solvent can be obtained, which is preferable.

[0028] The metal content of the quaternary ammonium salt is preferably 5 ppm or less by mass, more preferably 1 ppm or less, and even more preferably 500 ppb or less. If the metal content of the quaternary ammonium compound is 5 ppm or less, it can be used for electronic information materials such as displays and semiconductors.

[0029] The quaternary ammonium compound may be added as an aqueous solution, which is easier to add, from the standpoint of workability.

[0030] In the method for producing a silicone polymer of the present invention, water is used to hydrolyze a silane compound selected from the compounds represented by general formula (1) and (2). The type of water is not particularly limited, but industrial water, city water, well water, distilled water, ion-exchanged water, ultrapure water, etc. may be used. One type of water may be used, or two or more types may be used.

[0031] Among these, ion-exchanged water and ultrapure water, which have high electrical resistivity, are preferred, and ultrapure water, which has an electrical resistivity of 15 MΩ·cm or more and has a low metal content, is more preferred.

[0032] The amount of water used is preferably 1.0 to 15.0 times by mol, more preferably 1.0 to 10.0 times by mol, based on the number of moles of alkoxyl groups in at least one silane compound selected from the compound represented by the general formula (1) and the compound represented by the general formula (2). It is even more preferably 1.0 to 5.0 times by mol. When the amount of water is 1.0 times by mol or more, the hydrolysis and condensation polymerization reaction proceeds quickly, and when the amount of water is 15.0 times by mol or less, the reaction is controlled and gelation does not occur, which is preferable.

[0033] In the method for producing a silicone polymer of the present invention, the reaction liquid is contacted with a cation exchange resin. The cation exchange resin may be a strong acid cation exchange resin or a weak acid cation exchange resin. A commonly used cation exchange resin, for example, a commercially available hydrogen type cation exchange resin, specifically, for example, Amberlyist (manufactured by Organo Corporation), Lewatit (manufactured by Lanxess KK), Diaion (manufactured by Mitsubishi Chemical Corporation), Monosphere (manufactured by Dow Chemical Company), etc., can be used. The cation exchange resin is preferably a strong acid cation exchange resin.

[0034] The reaction liquid containing at least one silane compound selected from the compounds represented by the general formula (1) and the compounds represented by the general formula (2), a quaternary ammonium compound, and water can be contacted with a cation exchange resin by passing the reaction liquid through a column packed with a cation exchange resin, adding a cation exchange resin to the reaction liquid and stirring it, etc. In the latter case, the cation exchange resin is removed by filtration or the like after the treatment.

[0035] In the method for producing a silicone polymer of the present invention, it is preferable to flow a reaction liquid containing at least one silane compound selected from the compounds represented by general formula (1) and the compounds represented by general formula (2), a quaternary ammonium compound, and water through a tank filled with a cation exchange resin to bring the reaction liquid into contact with the cation exchange resin.

[0036] The amount of the cation exchange resin is preferably 1.0 to 10.0 equivalents relative to 1.0 equivalent of the quaternary ammonium compound used, more preferably 1.1 to 8.0 equivalents, and even more preferably 1.2 to 5.0 equivalents. If the amount of the cation exchange resin used is 1.0 equivalent or more, the quaternary ammonium compound can be removed, and if it is 10.0 equivalent or less, the obtained silicone polymer is stable and the amount of the cation exchange resin used is small, which is economically preferable.

[0037] The temperature at which the reaction liquid is contacted with the cation exchange resin is preferably 0 to 60° C., and more preferably 5 to 50° C. If the temperature is 0° C. or higher, the quaternary ammonium compound is sufficiently removed, and if the temperature is 60° C. or lower, the silicone polymer is stable, which is preferable.

[0038] The time for contacting the reaction liquid with the cation exchange resin is preferably 5 minutes to 6 hours, more preferably 10 minutes to 3 hours. If the contact time is 5 minutes or more, the quaternary ammonium compound can be sufficiently removed, and if it is 6 hours or less, the silicone polymer is stable, which is preferable.

[0039] In the method for producing a silicone polymer of the present invention, when reacting a silane compound selected from the compound represented by general formula (1) and the compound represented by general formula (2), an alcohol having a boiling point of 100°C or less may be added. Examples of alcohols having a boiling point of 100°C or less include methanol, ethanol, n-propanol, and isopropanol. Among these, methanol is preferred because it is easy to distill off. Two or more types of alcohols having a boiling point of 100°C or less may be used.

[0040] The amount of the alcohol having a boiling point of 100°C or less is preferably 1.0 to 10 times by mass, more preferably 1.2 to 8 times by mass, and even more preferably 1.5 to 5 times by mass, relative to the mass of the silane compound selected from the compound represented by general formula (1) and the compound represented by general formula (2). By having 1.0 times or more by mass of the alcohol having a boiling point of 100°C or less, the silane compound selected from the compound represented by general formula (1) and the compound represented by general formula (2) can be easily mixed with water, and gelation of the silicone polymer can be suppressed and stabilized. It is economically preferable to have 10 times or less by mass of the alcohol having a boiling point of 100°C or less.

[0041] In the method for producing a silicone polymer of the present invention, a solvent may be added in addition to the alcohol having a boiling point of 100° C. or less. Examples of the solvent that can be used include aprotic solvents such as toluene and xylene, ketone-based solvents such as methyl ethyl ketone and methyl isobutyl ketone, ether-based solvents such as diethyl ether and tetrahydrofuran, and high-boiling solvents such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, propylene glycol monoethyl ether, and ethyl lactate. Two or more types of solvents may be used.

[0042] In the method for producing a silicone polymer of the present invention, the weight average molecular weight of the silicone polymer is preferably 300 to 100,000, more preferably 500 to 50,000, and even more preferably 1,000 to 20,000. If the weight average molecular weight is 300 or more, the silicone polymer can be formed into a coating film, and if it is 100,000 or less, the silicone polymer is soluble in an organic solvent, which is preferable.

[0043] The dispersity (Mw / Mn) obtained by dividing the weight average molecular weight (Mw) by the number average molecular weight (Mn) is preferably 1-20, and more preferably 1-5.

[0044] In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and Z average molecular weight (Mz) of the silicone polymer can be measured using gel permeation chromatography (GPC) and calculated relative to standard polystyrene.

[0045] In the method for producing a silicone polymer of the present invention, the silicone polymer may have a cage-type higher-order structure.

[0046] The silicone polymer obtained by the method for producing a silicone polymer of the present invention may be dissolved in a solvent. As the solvent, an alcohol-based solvent or a high-boiling point solvent is used. As the alcohol-based solvent, an alcohol-based solvent such as methanol, ethanol, isopropanol, etc., and as the high-boiling point solvent, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, ethyl lactate, etc. are used.

[0047] A general method for obtaining a coating film using the silicone polymer obtained by the method for producing a silicone polymer of the present invention will be described below.

[0048] The coating film is prepared by spin-coating a silicone polymer onto a substrate to form a thin film, which is then heated to obtain the coating film. Examples of the substrate material include glass, silicon wafers, and resins such as polyethylene, polypropylene, and polypropylene terephthalate.

[0049] The thin film formed on the substrate is heated on a hot plate or incubator to remove the solvent and to cause hydrolysis and polycondensation reactions of the silicone polymer, thereby producing a coating film.

[0050] In general, in the preparation of a film, the coating film can be prepared by heating at preferably 80° C. or higher, more preferably 100° C. or higher.

[0051] The coating film produced in this manner is extremely hard, with a pencil hardness of 4H or more, and has excellent scratch resistance.

[0052] As described above, the silicone polymer obtained by the method for producing a silicone polymer of the present invention can be easily used to give a coating film, and is therefore suitable for use in semiconductors, displays, and the like. EXAMPLES

[0053] The present invention will be described in detail below with reference to examples and comparative examples. In the following examples, the following apparatuses were used for analysis, and general reagents purchased from reagent manufacturers were used as raw materials unless otherwise specified. The following methods were used for analysis.

[0054] ·Molecular weight measurement Analysis was performed using a Tosoh HLC-8220 GPC system with Tosoh TSKgel SuperHZ3000, TSKgel SuperHZ2000, and TSKgel SuperHZ1000 connected in series. Detection was performed with an RI (refractometer), and one TSKgel SuperH-RC was used as the reference column. Wako Pure Chemical Industries used tetrahydrofuran as the developing solvent, and the flow rate of the column and reference column was 0.35 mL / min. The measurement temperature was 40°C for both the plunger pump and the column. The sample was prepared by diluting approximately 0.025 g of silicone polymer with 10 mL of tetrahydrofuran, and then injecting 25 μL of the diluted solution. For molecular weight distribution calculations, TSK standard polystyrenes (A-500, A-1000, A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40, F-80) manufactured by Tosoh Corporation were used as standards.

[0055] Solid concentration measurement 1.0 g of the solution containing the silicone polymer was precisely weighed into an aluminum cup and baked at 175°C for 1 hour using a hot plate to measure the mass of solids relative to 1.0 g of the solution containing the silicone polymer, and the solids concentration (mass%) of the solution containing the silicone polymer was calculated.

[0056] Scratch hardness test The test was performed according to JIS K 5600-5-4 scratch hardness (pencil method). However, the coating film was prepared by the following method. 1 ml of a solution containing a silicone polymer was dropped onto a silicon wafer, and a thin film was formed using a spin coater (1000 rpm). The obtained thin film was baked for 90 seconds on a hot plate at 130°C, then placed on a hot plate at 250°C, covered with a metal lid, and baked for 1 hour. The obtained coating film was subjected to a scratch hardness test. The thickness of the coating film was measured using an optical interference film thickness measuring device (Lambda Ace, manufactured by Screen Semiconductor Solutions Co., Ltd.).

[0057] Example 1 In a 100 ml screw vial, 2.45 g (0.018 mol) of methyltrimethoxysilane, 6.39 g (0.042 mol) of tetramethoxysilane, 26.52 g of methanol (3.0 times the mass of the silane compound), and 4.42 g of ion-exchanged water were charged. Furthermore, a magnetic stirrer was added and the mixture was stirred. Next, 12.82 g (0.232 mol times / alkoxy group) of 50% 2-hydroxyethyltrimethylammonium hydroxide aqueous solution was dripped. The amount of water charged was 2.72 mol times / alkoxy group, which is the sum of the ion-exchanged water charged in advance and the amount of water accompanying the 50% 2-hydroxyethyltrimethylammonium hydroxide aqueous solution. After dripping, the reaction solution was aged at room temperature for 3 hours. Separately, one end of a cylindrical column made of SUS304 with a diameter of 13.5 mm and a length of 200 mm was packed with quartz wool to the extent that the ion exchange resin would not flow out, and then packed with a cation exchange resin (Amberlyst15JWET, Organo Corporation) that had been previously substituted with methanol. Two cylinders were connected in series, and the amount of cation exchange resin packed was 56 cm. 3 After aging, the reaction solution was pumped through a 28 cm column packed with ion exchange resin using a plunger pump. 3The reaction liquid was pumped at a rate of 10.5 g / h. After all the reaction liquid had been transferred, methanol was pumped to push the reaction liquid out of the column. An equal amount of propylene glycol monoethyl ether was added to the reaction liquid obtained, and the mixture was concentrated under reduced pressure to obtain a colorless, transparent liquid containing a silicone polymer. The solid content of the resulting colorless, transparent liquid was 10.2 mass%. The yield of the silicone polymer calculated from the solid content was 78%, the weight average molecular weight (Mw) of the silicone polymer was 5,090, and the dispersity (Mw / Mn) was 3.89. The scratch hardness of the coating was 6H.

[0058] Example 2 In a 100 ml screw vial, 5.18 g (0.038 mol) of methyltrimethoxysilane, 8.68 g (0.057 mol) of tetramethoxysilane, and 41.55 g of methanol (3.0 times the mass of the silane compound) were charged. Furthermore, a magnetic stirrer was added and the mixture was stirred. Next, 12.24 g (0.144 mol times / alkoxy group) of 50% 2-hydroxyethyltrimethylammonium hydroxide aqueous solution was dripped. Therefore, the amount of water charged was 1.02 mol times / alkoxy group. After dripping, the reaction solution was aged at room temperature for 3 hours. Separately, one end of a cylindrical column made of SUS304 with a diameter of 13.5 mm and a length of 20 mm was filled with quartz wool to the extent that the ion exchange resin did not flow out, and then filled with a cation exchange resin (Amberlyst15JWET, Organo Co., Ltd.) that had been previously replaced with methanol. Two columns were connected in series, and the amount of cation exchange resin packed was 56 cm 3 After aging, the reaction solution was pumped through a 28 cm column packed with ion exchange resin using a plunger pump. 3The reaction liquid was pumped at a rate of 1000 ml / h. After all the reaction liquid had been transferred, methanol was pumped in to push the reaction liquid out of the column. An equal amount of propylene glycol monoethyl ether was added to the reaction liquid obtained, and the mixture was concentrated under reduced pressure to obtain a colorless, transparent liquid containing a silicone polymer. The solid content of the resulting colorless, transparent liquid was 17.9% by mass. The yield of the silicone polymer calculated from the solid content was 76%, and the weight average molecular weight (Mw) of the silicone polymer was 4,660 and the degree of dispersion (Mw / Mn) was 2.22. The scratch hardness of the coating was 6H.

[0059] Example 3 In Example 2, 5.18g (0.038mol) of methyltrimethoxysilane, 8.68g (0.057mol) of tetramethoxysilane, 41.55g of methanol (3.0 times by mass of silane compound), 12.24g of 50% 2-hydroxyethyltrimethylammonium hydroxide aqueous solution (0.144 times by mole / alkoxy group) were replaced with 6.42g (0.047mol) of methyltrimethoxysilane, 7.29g (0.047mol) of tetramethoxysilane, 27.42g of methanol (2.0 times by mass of silane compound), 11.91g of 50% 2-hydroxyethyltrimethylammonium hydroxide aqueous solution (0.144 times by mole / alkoxy group), and the silicone polymer was synthesized in the same manner, and a colorless and transparent viscous liquid containing a silicone polymer was obtained. The solid content concentration of the obtained colorless and transparent viscous liquid was 15.6% by mass. The yield of the silicone polymer calculated from the solid content was 82%, the weight average molecular weight (Mw) of the silicone polymer was 3,600, and the dispersity (Mw / Mn) was 2.00. The scratch hardness of the coating was 6H.

[0060] Comparative Example 1 In a 100 ml screw vial, 2.45 g (0.018 mol) of methyltrimethoxysilane, 6.39 g (0.042 mol) of tetramethoxysilane, 26.52 g of methanol (3.0 times the mass of the silane compound), and 4.42 g of ion-exchanged water were charged. Furthermore, a magnetic stirrer was added and the mixture was stirred. Next, 12.82 g (0.232 mol times / alkoxy group) of 50% 2-hydroxyethyltrimethylammonium hydroxide aqueous solution was dripped. The amount of water charged was 2.72 mol times / alkoxy group, which is the sum of the ion-exchanged water charged in advance and the amount of water accompanying the 50% 2-hydroxyethyltrimethylammonium hydroxide aqueous solution. After dripping, the reaction solution was aged at room temperature for 3 hours. Separately, 7.17 g of maleic acid, 13.26 g of ion-exchanged water, and 88.40 g of ethyl acetate were charged into a 200 ml screw vial and stirred with a magnetic stirrer, and the reaction solution after aging was then added dropwise to neutralize the 2-hydroxyethyltrimethylammonium hydroxide added as a catalyst to the reaction solution. However, even when 10 times the mass of ethyl acetate was added relative to the silicone polymer, the reaction solution became homogenous and separation was not possible, so it was not possible to obtain a silicone polymer in a neutralized state with the salt removed.

[0061] Comparative Example 2 An experiment was carried out in the same manner as in Comparative Example 1, except that 26.52 g of methanol (3.0 times the mass of the silane compound) was changed to 4.42 g of methanol (0.5 times the mass of the silane compound). As a result, the silicone polymer gelled during neutralization, and a silicone polymer soluble in an organic solvent was not obtained.

[0062] Comparative Example 3 In Example 1, 12.82 g (0.232 mole times / alkoxy group) of a 50% aqueous 2-hydroxyethyltrimethylammonium hydroxide solution was not added dropwise. Therefore, the amount of water charged was only ion-exchanged water that had been charged beforehand, and was changed to 1.12 mole times / alkoxy group. However, the experiment was carried out in the same manner. As a result, the weight-average molecular weight (Mw) of the obtained silicone polymer was 530, and a silicone polymer polymerized to an extent that it could be applied as a film was not obtained.

[0063]

Table 1

Claims

1. A compound represented by the following general formula (1): R a Si(OR 1 ) 4-a ・・・・・(1) (Wherein, R is a methyl group or an ethyl group, R 1 represents a methyl group or an ethyl group, and a represents 1.) and a compound represented by the following general formula (2): Si(OR 2 ) 4 ・・・・・(2) (In the formula, R 2 indicates a methyl group or an ethyl group.) wherein, when the total amount of the compound represented by general formula (1) and the compound represented by general formula (2) is taken as 100 mol %, a silane compound having a content of 50 to 100 mol % of the compound represented by general formula (2) is selected from the group consisting of a quaternary ammonium compound and a silane compound which is hydrolyzed in the presence of water, and then the silane compound is brought into contact with a cation exchange resin.

2. The method for producing a silicone polymer according to claim 1, wherein a reaction liquid containing a silane compound consisting of the compound represented by the general formula (1) and the compound represented by the general formula (2), a quaternary ammonium compound, and water is passed through a tank filled with a cation exchange resin to contact the cation exchange resin.

3. The method for producing a silicone polymer according to claim 1 or 2, wherein the amount of the quaternary ammonium compound used is 0.002 to 2 moles per mole of the total amount of alkoxyl groups possessed by the silane compound selected from the compound represented by general formula (1) and the compound represented by general formula (2).

4. 4. The method for producing a silicone polymer according to claim 1, wherein the quaternary ammonium compound is a quaternary ammonium compound containing a hydroxyl group.

5. 5. The method for producing a silicone polymer according to claim 4, wherein the quaternary ammonium compound containing a hydroxyl group is 2-hydroxyethyltrimethylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, or tris(2-hydroxyethyl)methylammonium hydroxide.

6. The method for producing a silicone polymer according to any one of claims 1 to 5, wherein the cation exchange resin is a strongly acidic cation exchange resin.

7. The cation exchange resin is used in an amount of 1.0 to 10.0 equivalents per 1.0 equivalent of the quaternary ammonium compound. The method for producing the silicone polymer according to any one of claims 1 to 6.

8. The method for producing a silicone polymer according to any one of claims 1 to 7, wherein a silane compound selected from the compound represented by general formula (1) and the compound represented by general formula (2) is hydrolyzed in the presence of an alcohol having a boiling point of 100°C or less.

9. The method for producing a silicone polymer according to claim 8, wherein the amount of the alcohol used is 1.0 to 10 times by mass relative to the amount of the silane compound selected from the compound represented by general formula (1) and the compound represented by general formula (2).

10. A method for forming a film, comprising applying the silicone polymer obtained by the method according to any one of claims 1 to 9 onto a substrate and heating the applied silicone polymer.

11. The method for forming a film according to claim 10, wherein the pencil hardness of the film is 4H or more.

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