Method for producing solvent-free siloxane composition

Abstract

Provided is a method for producing a solvent-free siloxane composition which is solvent-free and has excellent long-term stability. A method for producing a solvent-free siloxane composition, the method including the following steps (1), (2), and (3) in this order. Step (1): A step for preparing a siloxane compound having a silanol group at a terminal by reacting a silane compound. Step (2): After the amide compound has been added, a step for dehydrating with an orthoester and removing the solvent by evaporation is performed. Step (3): A step for obtaining a terminated siloxane compound by dissolving the terminal silanol group-containing siloxane compound in an organic solvent and then adding a blocking agent.

Description

[CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the priority of invention patent application "Japanese Patent Application No. 2023-121729" filed with the Japan Patent Office on July 26, 2023, and all contents disclosed in that application are hereby incorporated as a whole into the description of this application. Technical Field

[0001] The invention relates to a method for preparing a solvent-free silicone composition. Background Art

[0002] Various coating materials such as various lens materials and planarizing films are used in solid-state imaging devices such as charge coupled devices (CCDs) and complementary metal-oxide semiconductor (CMOS) image sensors, substrates for displays, and various anti-reflection films.

[0003] Such coating materials are required to have many properties such as heat resistance, low temperature processability, etc. in addition to optical properties such as transparency and appropriate refractive index. In addition, alkali solubility is also required depending on the application. For such requirements, resin compositions containing siloxane compounds are known to be suitable.

[0004] For example, Patent Document 1 discloses a low-refractive-index film-forming composition characterized by containing a silicone resin obtained by hydrolyzing and condensing a mixed raw material containing two or more specific silane compounds. Prior art literature Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-203059 Summary of the invention Problem that the invention aims to solve

[0006] However, the low-refractive-index film-forming composition described in Patent Document 1 has a problem of insufficient stability over time.

[0007] In addition, the low-refractive-index film-forming composition described in Patent Document 1 contains a solvent. In recent years, solvent-free types have been desired from the perspective of environmental issues. When the silicone resin described in Patent Document 1 is made into a solvent-free type at a high concentration, the condensation reaction of the silanol group leads to gelation, and thus it is difficult to make it into a solvent-free type. Means used to solve problems

[0008] The present invention is a method for producing a solvent-free silicone composition comprising the following steps (1), (2) and (3) in sequence. Process (1) A step of reacting a silane compound to prepare a siloxane compound having a silanol group at the terminal. Process (2) After the addition of the amide compound, the steps of dehydration with the orthoester and solvent distillation are performed. Process (3) A step of dissolving the terminal silanol group-containing siloxane compound in an organic solvent and then adding a blocking agent to obtain a blocked siloxane compound.

[0009] In the method for producing a solventless siloxane composition of the present invention, when obtaining a solventless siloxane composition having a low refractive index, the silane compound preferably includes at least one selected from the group consisting of the following formula (1) and the following formulas (2) to (4). Si(A 1 )(A 2 ) a (OR 1 ) 3-a (1) In formula (1), A 1 represents a monovalent organic group having a free radical polymerizable double bond, A 2 represents an alkyl group or a silyl group, R 1 Represents an alkyl group; multiple R 1 can be the same or different; a is 0 or 1; Si(B 1 )(B 2 ) b (OR 2 ) 3-b (2) In formula (2), B 1 represents an alkyl group, B 2 Represents silyl group, R 2 Represents an alkyl group; multiple R 2 can be the same or different; b is 0 or 1; Si(C 1 )2(C 2 ) c (OR 3 ) 2-c (3) In formula (3), C 1 represents an alkyl group, C 2 Represents silyl group, R 3 Represents an alkyl group; two C 1 Can be the same or different, multiple R 3Can be the same or different; c is 0 or 1; Si(D 1 )(D 2 ) d (OR 4 ) 3-d (4) In formula (4), D 1 represents a fluoroalkyl group having 3 to 13 fluorine atoms, D 2 represents an alkyl group, a silyl group or a monovalent organic group having a free radical polymerizable double bond, R 4 Represents an alkyl group; multiple R 4 They can be the same or different, and d is 0 or 1. Furthermore, the silane compound preferably contains at least two selected from the group consisting of the above formulae (2) to (4). In addition, the silane compound preferably includes the above-mentioned formulas (2) and (3). In addition, it is preferred that: when the mass ratio of the above formula (1) is set to w1, the mass ratio of the above formula (2) is set to w2, the mass ratio of the above formula (3) is set to w3, and the mass ratio of the above formula (4) is set to w4, w1 is 10 to 30, w2 is 0 to 90, w3 is 0 to 90, w4 is 0 to 90, and w2+w3+w4 is 70 to 90. In addition, the mass ratio w1 in the above formula (1) is preferably 20 or less. In addition, the terminal blocking agent is preferably hexamethyldisilazane. Effects of the Invention

[0010] The present invention can provide a method for producing a solvent-free silicone composition, by which a solvent-free silicone composition having excellent stability over time can be obtained. DETAILED DESCRIPTION

[0011] The method for producing a solvent-free silicone composition of the present invention comprises the following steps (1), (2) and (3) in order. Step (1): a step of reacting a silane compound to prepare a siloxane compound having a silanol group at a terminal. Step (2): After adding the amide compound, dehydration with the orthoester and evaporation of the solvent are performed. Step (3): a step of dissolving the terminal silanol group-containing siloxane compound in an organic solvent and then adding a blocking agent to obtain a blocked siloxane compound.

[0012] [Process (1)] The step (1) is a step of reacting a silane-based compound to prepare a siloxane compound having a silanol group at a terminal.

[0013] In the step (1), for example, there can be mentioned a method in which a polymerization catalyst is added to a solution obtained by dissolving a silane compound in an organic solvent, and the mixture is reacted while being refluxed.

[0014] Examples of the silane compound include silane compounds represented by the following formulae (1) to (4). Si(A 1 )(A 2 ) a (OR 1 ) 3-a (1) In formula (1), A 1 represents a monovalent organic group having a free radical polymerizable double bond, A 2 represents an alkyl group or a silyl group, R 1 Represents an alkyl group; multiple R 1 can be the same or different; a is 0 or 1; Si(B 1 )(B 2 ) b (OR 2 ) 3-b (2) In formula (2), B 1 represents an alkyl group, B 2 Represents silyl group, R 2 Represents an alkyl group; multiple R 2 can be the same or different; b is 0 or 1; Si(C 1 )2(C 2 ) c (OR 3 ) 2-c (3) In formula (3), C 1 represents an alkyl group, C 2 Represents silyl group, R 3 Represents an alkyl group; two C 1 Can be the same or different, multiple R 3 Can be the same or different; c is 0 or 1; Si(D 1 )(D 2 ) d (OR 4 ) 3-d (4) In formula (4), D 1 represents a fluoroalkyl group having 3 to 13 fluorine atoms, D 2 represents an alkyl group, a silyl group or a monovalent organic group having a free radical polymerizable double bond, R4 Represents an alkyl group; multiple R 4 They can be the same or different, and d is 0 or 1.

[0016] In the above formula (1), A 1 Preferred is a vinyl group, an allyl group, or a monovalent organic group having a (meth)acryloyl group.

[0017] In the above general formula (1), A 2 An alkyl group having 1 to 10 carbon atoms is preferred. Examples of such an alkyl group include methyl, ethyl, propyl, isopropyl, tert-butyl, n-butyl and sec-butyl.

[0018] In the above general formula (1), R 1 An alkyl group having 1 to 10 carbon atoms is preferred. Examples of such an alkyl group include methyl, ethyl, propyl, isopropyl, tert-butyl, n-butyl and sec-butyl.

[0019] In the above general formula (1), a is preferably 0.

[0020] Examples of the general formula (1) include vinyl silane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, methylvinyldimethoxysilane, and methylvinyldiethoxysilane; 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylethyldiethoxysilane, and 3-(meth)acryloxypropyltriethoxysilane; and allylsilane compounds such as allyltrimethoxysilane and allyltriethoxysilane.

[0021] In the above formula (2), B 1 An alkyl group having 1 to 10 carbon atoms is preferred. Examples of such an alkyl group include methyl, ethyl, propyl, isopropyl, tert-butyl, n-butyl and sec-butyl.

[0022] In the above formula (2), B 2 It is a siloxy group.

[0023] In the above formula (2), R 2 An alkyl group having 1 to 10 carbon atoms is preferred. Examples of such an alkyl group include methyl, ethyl, propyl, isopropyl, tert-butyl, n-butyl and sec-butyl.

[0024] In the above formula (2), b is preferably 0.

[0025] Examples of the above formula (2) include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopropoxysilane, methyltri-n-butoxysilane, methyltri-tert-butoxysilane, methyltri-sec-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, dimethyldimethoxysilane, and dimethyldiethoxysilane.

[0026] In the above formula (3), C 1 An alkyl group having 1 to 10 carbon atoms is preferred. Examples of such an alkyl group include methyl, ethyl, propyl, isopropyl, tert-butyl, n-butyl and sec-butyl.

[0027] In the above formula (3), C 2 It is a siloxy group.

[0028] In the above formula (3), R 3 An alkyl group having 1 to 10 carbon atoms is preferred. Examples of such an alkyl group include methyl, ethyl, propyl, isopropyl, tert-butyl, n-butyl and sec-butyl.

[0029] In the above formula (3), c is preferably 0.

[0030] Examples of the above formula (3) include dimethyldimethoxysilane and dimethyldiethoxysilane.

[0031] In the above formula (4), D 1 The solvent-free silicone composition can be appropriately selected according to the application of the coating film. For example, in order to make the refractive index smaller, the number of fluorine is preferably selected within the range of 9 to 13. In addition, for example, in order to maintain hardness and reduce the refractive index, the number of fluorine is preferably selected within the range of 3 to 5.

[0032] In the above formula (4), D 2 An alkyl group having 1 to 10 carbon atoms is preferred. Examples of such an alkyl group include methyl, ethyl, propyl, isopropyl, tert-butyl, n-butyl and sec-butyl.

[0033] In the above formula (4), R 4 An alkyl group having 1 to 10 carbon atoms is preferred. Examples of such an alkyl group include methyl, ethyl, propyl, isopropyl, tert-butyl, n-butyl and sec-butyl.

[0034] In the above formula (4), d is preferably 0.

[0035] Examples of the above formula (4) include trifluoropropylmethyldimethoxysilane, trifluoropropylmethyldiethoxysilane, trifluoropropylmethyldipropoxysilane, trifluoropropylmethyldiisopropoxysilane, trifluoropropylethyldimethoxysilane, trifluoropropylethyldiethoxysilane, heptadecafluorodecylmethyldimethoxysilane, tridecafluorooctylmethyldimethoxysilane, tridecafluorooctylmethyldiethoxysilane, tridecafluorooctylmethyldipropoxysilane, tridecafluorooctylmethyldiisopropoxysilane, trifluoropropylvinyldimethoxysilane, trifluoropropylvinyldiethoxysilane, and trifluoropropyltrialkoxysilane.

[0036] As the silane compound, silane compounds other than those represented by the above formulae (1) to (4) may be used. Examples of such silane compounds include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, and 3-trimethoxysilylpropylsuccinic anhydride.

[0037] In the method for producing a solvent-free silicone composition of the present invention, the above-mentioned silane compound may be appropriately selected to carry out the above-mentioned step (1).

[0038] In the method for producing a solventless siloxane composition of the present invention, when obtaining a solventless siloxane composition having a low refractive index, the silane compound preferably includes at least one selected from the group consisting of the following formula (1) and the following formulas (2) to (4). Next, the composition ratio in the case of obtaining a solvent-free siloxane composition having a low refractive index will be described.

[0039] The silane compound preferably includes at least two selected from the group consisting of the above formulae (2) to (4), and more preferably includes the above formulae (2) and (3).

[0040] Preferably, when the mass ratio of the above formula (1) is set to w1, the mass ratio of the above formula (2) is set to w2, the mass ratio of the above formula (3) is set to w3, and the mass ratio of the above formula (4) is set to w4, w1 is 10 to 30, w2 is 0 to 90, w3 is 0 to 90, w4 is 0 to 90, and w2+w3+w4 is 70 to 90. The mass ratios w1 to w4 refer to mass ratios relative to the silane compound used in the step (1).

[0041] The mass ratio w1 in the above formula (1) is preferably 20 or less, and more preferably 15 or less.

[0042] The mass ratio w2 in the above formula (2) is preferably 0-90, more preferably 30-80.

[0043] The mass ratio w3 in the above formula (3) is preferably 0-90, more preferably 5-30.

[0044] The mass ratio w4 in the above formula (4) is preferably 50 or less, more preferably 10 or less, and further preferably 0 from the viewpoint of environmental load.

[0045] The usage-amount of the silane-type compound other than the said formula (1) - (4) is preferably 1-10 mass parts with respect to 100 mass parts of the total mass of w1, w2, w3, and w4.

[0046] The organic solvent used in the above step (1) is preferably a lower alcohol such as ethanol, n-propanol, isopropanol, or the like; a ketone compound such as acetone, methyl ethyl ketone, or the like; or an ester compound such as ethyl acetate, n-propyl acetate, or the like. Among them, lower alcohols are more preferred, and ethanol and isopropanol are even more preferred from the viewpoint of being able to maintain an appropriate reaction temperature and being easily distilled off.

[0047] Examples of the polymerization catalyst used in the step (1) include acid catalysts such as acetic acid, hydrochloric acid, and p-toluenesulfonic acid monohydrate, and base catalysts such as ammonia, triethylamine, cyclohexylamine, and tetramethylammonium hydroxide.

[0048] The amount of the polymerization catalyst is preferably an amount that is about 0.05 to 0.2 times the total number of molecules of the silane compound.

[0049] The reaction temperature is preferably 60 to 80° C., and the reaction time is preferably about 2 to 24 hours in order to allow the reaction to proceed sufficiently.

[0050] [Step (2)] Step (2) is a step of adding an amide compound, followed by dehydration with an orthoester and evaporation of the solvent.

[0051] Examples of the amide compounds include N,N-dimethylacetamide, N,N-dimethylformamide, and N,N-diethylformamide.

[0052] The amount of the amide compound added is about 15 to 40% by mass based on the total amount of the silane compound.

[0053] After the amide compound is added, stirring is preferably performed. The stirring temperature at this time is preferably 10 to 40° C., and the stirring is preferably performed for 0.5 to 1 hour.

[0054] Examples of the orthoester include triethyl orthoacetate, trimethyl orthoformate, and triethyl orthoformate. By using the above-mentioned orthoester, water generated by the reaction can be removed.

[0055] When the orthoester is added dropwise, it is preferred that the temperature be not higher than 30° C. from the viewpoint of preventing a side reaction.

[0056] The method for distilling off the solvent is not particularly limited, and the solvent may be distilled off by a known method, for example, distillation may be performed under reduced pressure.

[0057] The siloxane compound having a terminal silanol group can be stabilized by the reaction of the siloxane compound having a terminal silanol group with the amide compound.

[0058] [Step (3)] Step (3) is a step of dissolving the terminal silanol group-containing siloxane compound in an organic solvent, adding at least one selected from the group consisting of an acid, an acid anhydride, an acid chloride and an ester, and then adding a blocking agent to obtain a blocked siloxane compound.

[0059] As the organic solvent, any one of those described in the above step (1) may be appropriately selected.

[0060] In the above step (3), it is preferred that the end-capping agent is added after adding at least one selected from the group consisting of an acid, an acid anhydride, an acid chloride and an ester. Examples of the acid, acid anhydride, acid chloride and ester include acetic anhydride, acetic acid, succinic acid, succinic anhydride and the like.

[0061] The amount of at least one selected from the group consisting of the acid, the acid anhydride, the acid chloride and the ester added is about 50 to 100% by mass based on the total mass of the terminal blocking agent. This makes it possible to remove ammonia incidentally generated when the terminal is blocked with the blocking agent. The step of adding a blocking agent after adding at least one selected from the group consisting of the acid, acid anhydride, acid chloride and ester may be omitted because ammonia is not incidentally generated depending on the type of the blocking agent.

[0062] Examples of the terminal blocking agent include hexamethyldisilazane, trimethylsilyl chloride, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine. Among them, hexamethyldisilazane is preferred from the viewpoint of cost.

[0063] The amount of the terminal blocking agent added varies depending on the number of silanol groups in the terminal silanol group-containing siloxane compound, and is, for example, 50% by mass or more based on the total mass of the terminal silanol group-containing siloxane compound. By setting the amount of the terminal blocking agent added to be within the above range, the siloxane compound can be sufficiently terminal blocked, and stability over time can be imparted. The upper limit of the amount of the terminal blocking agent added is not particularly limited, but is, for example, 200% by mass based on the total mass of the terminal silanol group-containing siloxane compound.

[0064] In the above step (3), the reaction temperature is preferably 10 to 50° C. from the viewpoint of preventing a side reaction.

[0065] In the above step (3), the reaction time is preferably about 3 to 15 hours in order to allow the reaction to proceed sufficiently.

[0066] [other] After the above step (3), it is preferred to remove by-products and residues, and to distill off the organic solvent and water.

[0067] As a method for removing the above-mentioned by-products and residues, a known method can be used, and for example, by-products and residues can be removed by neutralization or mixing with water.

[0068] The organic solvent and water can be evaporated by a known method, for example, water can be removed by sodium sulfate, and the solvent can be evaporated by drying under reduced pressure.

[0069] By distilling off the organic solvent and water, a solvent-free siloxane compound can be obtained.

[0070] [Siloxane compounds] The blocked siloxane compound (also simply referred to as a siloxane compound) obtained through the above steps (1) to (3) and the like will be described.

[0071] The weight average molecular weight (Mw) of the siloxane compound is preferably 800 to 10000. If the weight average molecular weight (Mw) is less than 800, the film-forming property and curing property of the solvent-free siloxane composition described below may be reduced, and if the weight average molecular weight (Mw) exceeds 10000, the viscosity may become too high. The weight average molecular weight (Mw) of the siloxane compound is more preferably 1,500 to 2,500.

[0072] The weight average molecular weight (Mw) can be measured by dissolving the siloxane compound to prepare a solution of 0.02 parts by mass, passing the solution through a filter (manufactured by GL Sciences Inc., GL chromatographic disk, aqueous 25A, pore size 0.2 μm), and then measuring the solution under the following conditions using alliance (manufactured by Waters Corporation, Japan) comprising a size exclusion chromatograph and a refractive index detector. Column: pLgel mixed D (manufactured by Agilent) × 2 connected in series Detector: alliance (manufactured by Waters Corporation, Japan) Eluent: Tetrahydrofuran (THF) Flow rate: 1.0ml / min Injection volume: 100 μl

[0073] [Solvent-free silicone composition] The solvent-free silicone composition will be described. The solvent-free silicone composition contains the above-mentioned silicone compound and additives described below. In this specification, the term "solvent-free type" means that the mass loss under reduced pressure (5 hPa or less) at 160°C for 2 hours is less than 1%.

[0074] The solvent-free silicone composition may contain a leveling agent.

[0075] Examples of the leveling agent include silicone-based surfactants and fluorine-based surfactants. Among them, silicone surfactants are more suitable as the leveling agent of the present invention.

[0076] The content of the leveling agent is preferably 0.05 to 1 part by mass relative to 100 parts by mass of the siloxane compound.

[0077] The solvent-free silicone composition may contain a photopolymerizable compound.

[0078] As the photopolymerizable compound, a photopolymerizable compound having a radical polymerizable unsaturated double bond is preferred.

[0079] Examples of the photopolymerizable compound having two or more free radical polymerizable unsaturated double bonds include ester compounds of divalent or higher hydroxyl-containing compounds and (meth)acrylic acid, such as 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and the like. Ester, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, bisphenol A di(meth)acrylate, tri(2-hydroxyethyl)isocyanuric acid di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tri(2-hydroxyethyl)isocyanuric acid tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like.

[0080] Among them, from the viewpoint of being able to increase the crosslinking density and impart excellent hardness to the cured film, compounds having a trifunctional or higher reactive functional group are preferred, for example, trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(2-hydroxyethyl)isocyanuric acid tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate are preferred, and tris(2-hydroxyethyl)isocyanuric acid tri(meth)acrylate and dipentaerythritol hexa(meth)acrylate are more preferred.

[0081] It is preferred that the photopolymerizable compound is contained in an amount of 10 to 50 parts by mass based on 100 parts by mass of the siloxane compound. If the content of the photopolymerizable compound is less than 10 parts by mass relative to 100 parts by mass of the siloxane compound, the curability of the cured film and the adhesion to the light-transmitting substrate and the ITO electrode may be insufficient. If the content of the photopolymerizable compound exceeds 50 parts by mass relative to 100 parts by mass of the siloxane compound, the solubility of the uncured film in the developer may be insufficient.

[0082] The solvent-free silicone composition may contain a polymerization initiator.

[0083] As the polymerization initiator, it is preferable to use a polymerization initiator that can obtain a sufficient photocuring reaction when forming a cured film.

[0084] Examples of the polymerization initiator include benzyl, benzoin, benzophenone, camphorquinone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-hydroxycyclohexylphenylketone, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl-[4'-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butane-1-one, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl) carbonyl compounds such as 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)-1,3,5-triazine and 2-[2-(2-furyl)vinyl]-4,6-bis(trichloromethyl)-1,3,5-triazine; imidazole dimers such as 2,2'-bis(2-chlorophenyl)4,5,4',5'-tetraphenyl 1,2'-biimidazole; thioxanthone compounds such as 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, and biguanide compounds such as 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidinium=2-(3-benzoylphenyl)propionate; and the like.

[0085] These polymerization initiators may be used alone or in combination of two or more, and may be combined with any photosensitizer. Furthermore, a photoacid generator or a photobase generator may be used in combination as a catalyst for accelerating the condensation reaction of the siloxane compound.

[0086] When the total amount of the siloxane compound and the photopolymerizable compound is 100 parts by mass, it is preferred that the polymerization initiator be contained in an amount of 0.5 to 40 parts by mass.

[0087] If the content of the polymerization initiator is less than 0.5 parts by mass, the photopolymerizability may be reduced, and unreacted components may remain in the exposed area by photolithography. If the content of the polymerization initiator exceeds 40 parts by mass, the storage stability of the solvent-free siloxane composition may be reduced. When the total amount of the siloxane compound and the polymerizable monomer having two or more radically polymerizable unsaturated double bonds is 100 parts by mass, the amount of the polymerization initiator is more preferably 1 to 20 parts by mass.

[0088] (Other materials) The solvent-free silicone composition may contain the following substances within the range that does not reduce the effect of the present invention: chelate compounds of metals such as aluminum, zirconium, and titanium; carbodiimides, isocyanates, crosslinking agents having crosslinking functional groups such as epoxy groups and thiol groups; surfactants such as silicones and fluorine groups; photosensitizers such as aromatic hydrocarbons, amino compounds, nitro compounds, quinones, and xanthones; polymerization inhibitors such as hydroquinone, p-methoxyphenol, hindered amines, hindered phenols, di-tert-butylhydroquinone, 4-methoxyphenol, 2,6-di-tert-butyl-p-cresol, and nitrosamine salts; and fillers such as inorganic metal oxides and organic microparticles.

[0089] As a method for producing the above-mentioned solvent-free siloxane composition, the following method can be utilized: an organic solvent is placed in a suitable container, and the above-mentioned siloxane compound, the above-mentioned photopolymerizable compound having two or more free radical polymerizable unsaturated double bonds, the above-mentioned polymerization initiator, and other materials are added and mixed while stirring with, for example, a high-speed stirrer. The method for producing the solvent-free silicone composition of the present invention is not limited to the above method, and the order of adding the various materials may be arbitrary. In addition, if the solid material is soluble in the organic solvent, the solid material can be dissolved before being put in. If the solid material can be dispersed in the organic solvent directly or using a dispersant, the solid material can be dispersed before being put in.

[0090] [Method for forming a cured film] The solvent-free silicone composition can form a cured film. The method for forming a cured film preferably includes: a coating step of coating a solvent-free silicone composition on a substrate; an exposure step of irradiating an exposed portion with active energy rays to form a cured film; and a development step of dissolving and removing the coating solution in an unexposed portion with a developer. In addition, after the above-mentioned coating step, thermal curing may be performed.

[0091] The coating method in the coating step, the active energy rays for irradiating the exposed portion in the exposure step and the irradiation method, and the developer for removing the coating solution in the exposed portion can be appropriately selected from active energy rays, developers and methods used in conventional photolithography.

[0092] For example, the solvent-free siloxane composition is diluted so that the concentration of the nonvolatile component becomes 20 mass %, applied using a spin coater, heated (pre-baked) at 80° C. for 3 minutes, and then irradiated with a mask aligner at 100 mJ / cm 2The test pattern is printed (engraved) under irradiation conditions, immersed in a developer for 1 minute, and then heated (post-baked) at 150° C. for 30 minutes, thereby obtaining a cured film. As the conditions for the pre-baking, it is preferable to perform the treatment at 60 to 130° C. for 1 to 3 minutes. The irradiation conditions are preferably 50 to 260 mJ / cm 2 . As the post-baking conditions, it is preferable to perform the treatment at 120 to 230° C. for 30 to 60 minutes.

[0093] The thermal curing may be performed by, for example, performing a heating treatment at 130° C. for 10 minutes and then performing a heating treatment at 180° C. for 60 minutes for curing.

[0094] [Physical properties of solvent-free silicone composition] The solvent-free silicone composition of the present invention is excellent in stability over time.

[0095] In this specification, the temporal stability is evaluated by the following method.

[0096] The viscosity and weight average molecular weight of the solvent-free silicone composition immediately after preparation and after storage at 40° C. for one week were compared. When the increase in viscosity and weight average molecular weight was less than 15%, it was judged that the stability over time was excellent. The viscosity was measured using an R115 type viscometer RE-105L (E type viscometer, manufactured by Toki Sangyo Co., Ltd.) (measurement temperature: 25° C.), and the weight average molecular weight was measured by the above-mentioned method. When the increase in viscosity and weight average molecular weight is less than 15%, it can be judged that the stability over time is excellent.

[0097] The following technical solutions are disclosed in this specification.

[0098] The present disclosure (1) is a method for producing a solvent-free silicone composition comprising the following steps (1), (2), and (3) in sequence. Process (1) A step of reacting a silane compound to prepare a siloxane compound having a silanol group at the terminal. Process (2) After the addition of the amide compound, the steps of dehydration with the orthoester and solvent distillation are performed. Process (3) A step of dissolving the terminal silanol group-containing siloxane compound in an organic solvent and then adding a blocking agent to obtain a blocked siloxane compound. The present disclosure (2) is a method for producing a solvent-free siloxane composition according to the present disclosure (1), wherein the silane compound comprises at least one selected from the group consisting of the above formula (1) and the above formulas (2) to (4). The present disclosure (3) is a method for producing a solvent-free siloxane composition according to the present disclosure (1) or (2), wherein the silane compound comprises at least two selected from the group consisting of the above formulae (2) to (4). The present disclosure (4) is a method for producing a solvent-free siloxane composition according to the present disclosure (3), wherein the siloxane compound comprises the above formulae (2) and (3). The present disclosure (5) is a method for producing a solvent-free silicone composition as described in any one of the present disclosures (1) to (4), wherein when the mass ratio of the above formula (1) is set to w1, the mass ratio of the above formula (2) is set to w2, the mass ratio of the above formula (3) is set to w3, and the mass ratio of the above formula (4) is set to w4, w1 is 10 to 30, w2 is 0 to 90, w3 is 0 to 90, w4 is 0 to 90, and w2+w3+w4 is 70 to 90. The present disclosure (6) is a method for producing a solvent-free siloxane composition according to the present disclosure (5), wherein the mass ratio w1 of the above formula (1) is 20 or less. The present disclosure (7) is a method for producing a solvent-free siloxane composition according to any one of the present disclosures (1) to (6), wherein the terminal blocking agent is hexamethyldisilazane. Example

[0099] Hereinafter, the present invention will be described in further detail by way of examples, but the present invention is not limited to these examples. In addition, unless otherwise specified, "%" means "mass %", and "part" means "mass part".

[0100] The materials used in Examples and Comparative Examples are as follows.

[0101] (Silane compound of the above formula (1)) 3-Acryloxypropyltrimethoxysilane (Silane compound of the above formula (2)) Methyltriethoxysilane (Silane compound of the above formula (3)) Dimethyldimethoxysilane (Silane compound of the above formula (4)) Trifluoropropyltrimethoxysilane (Polymerization Catalyst) p-Toluenesulfonic acid monohydrate (water) Ion exchange water (Amide compounds) N,N-Dimethylacetamide N,N-Dimethylformamide N,N-Diethylformamide (Orthoester) Trimethyl orthoacetate (Capping agent) Hexamethyldisilazane Trimethylsilane chloride

[0102] (Example 1) 59.3 g of methyltriethoxysilane, 10.0 g of dimethyldimethoxysilane, and 11.7 g of 3-acryloxypropyltrimethoxysilane were placed in a flask and stirred. On the other hand, a solution obtained by mixing 0.05 g of p-toluenesulfonic acid monohydrate and 18.9 g of ion exchange water was prepared. The solution was added dropwise to the flask over 15 minutes so that the temperature did not exceed 60° C. After the addition, stirring was performed at a temperature of 60° C. for 3 hours (“Step (1)”). After cooling, 15.1 g of N,N-dimethylacetamide was added and stirred. Then, 26.3 g of trimethyl orthoacetate was added dropwise so that the temperature did not exceed 30°C. Then, methanol, ethanol and water as by-products were removed by distillation under reduced pressure to obtain a concentrated solution of a siloxane compound containing a terminal silanol group ("step (2)"). To the concentrated solution of the siloxane compound containing a terminal silanol group were added 33.0 g of ethyl acetate and 28.4 g of acetic anhydride, followed by stirring. Then, 49.7 g of hexamethyldisilazane was added dropwise so that the temperature did not exceed 30° C., thereby obtaining a solution of a siloxane compound terminated with hexamethyldisilazane (“step (3)”). 33.0 g of hexane and 33.0 g of ion exchange water were added to the solution of the siloxane compound terminated with hexamethyldisilazane, and the mixture was stirred with a separatory funnel, and then allowed to stand until the organic layer and the aqueous layer were separated, and the aqueous layer was removed. After the aqueous layer was removed, a separation operation was performed using ion exchange water and a saturated sodium bicarbonate aqueous solution to take out the organic layer. 10.0 g of sodium sulfate was added to the organic layer taken out, and the mixture was stirred for 10 minutes to dehydrate. Then, the solution was filtered using a filter. Next, the solution was evaporated under reduced pressure at 60° C. for 1 hour, and then evaporated under reduced pressure at 120° C. for 3 hours to evaporate low-boiling-point components other than the siloxane compound, thereby obtaining a solvent-free siloxane composition containing a siloxane compound.

[0103] (Examples 2 to 6, 8) A solvent-free siloxane composition was obtained in the same manner as in Example 1 except that the addition amounts of various materials were changed as described in Table 1.

[0104] (Example 7) After carrying out steps (1) and (2) in the same manner as in Example 1, 33.0 g of ethyl acetate and 35.5 g of acetic anhydride were added to the concentrated solution of the terminal silanol group-containing siloxane compound, followed by stirring. Subsequently, 62.1 g of hexamethyldisilazane was added dropwise so that the temperature did not exceed 30° C., thereby obtaining a solution of a siloxane compound terminated with hexamethyldisilazane (“step (3)”). A solvent-free silicone composition was obtained in the same manner as in Example 1 except for the above.

[0105] (Example 9) A solvent-free siloxane composition was obtained in the same manner as in Example 1 except that 15.1 g of N,N-dimethylacetamide used in the step (2) of Example 1 was changed to 12.7 g of dimethylformamide.

[0106] (Example 10) A solvent-free siloxane composition was obtained in the same manner as in Example 1 except that 15.1 g of N,N-dimethylacetamide used in the step (2) of Example 1 was changed to 17.5 g of diethylformamide.

[0107] (Example 11) A solvent-free siloxane composition was obtained in the same manner as in Example 1 except that 28.4 g of acetic anhydride used in the step (3) of Example 1 was changed to 33.5 g of acetic acid.

[0108] (Example 12) A solvent-free siloxane composition was obtained in the same manner as in Example 1 except that 28.4 g of acetic anhydride used in the step (3) of Example 1 was changed to 27.9 g of succinic anhydride.

[0109] (Example 13) A solvent-free siloxane composition was obtained in the same manner as in Example 1 except that 28.4 g of acetic anhydride used in the step (3) of Example 1 was changed to 21.8 g of acetyl chloride.

[0110] (Example 14) After carrying out steps (1) and (2) in the same manner as in Example 1, 33.0 g of ethyl acetate was added to the concentrated solution of the siloxane compound containing a terminal silanol group, followed by stirring. Subsequently, 66.8 g of trimethylsilyl chloride was added dropwise so that the temperature did not exceed 30° C., thereby obtaining a solution of a siloxane compound capped with trimethylsilyl chloride (“step (3)”). A solvent-free silicone composition was obtained in the same manner as in Example 1 except for the above.

[0111] (Example 15) After carrying out steps (1) and (2) in the same manner as in Example 1, 33.0 g of ethyl acetate and 13.6 g of acetic anhydride were added to the concentrated solution of the siloxane compound containing a terminal silanol group, followed by stirring. Subsequently, 46.6 g of hexamethyldisilazane was added dropwise so that the temperature did not exceed 30° C., thereby obtaining a solution of a siloxane compound terminated with hexamethyldisilazane (“step (3)”). A solvent-free silicone composition was obtained in the same manner as in Example 1 except for the above.

[0112] (Comparative Example 1) 59.3 g of methyltriethoxysilane, 10.0 g of dimethyldimethoxysilane, and 11.7 g of 3-acryloxypropyltrimethoxysilane were placed in a flask and stirred. On the other hand, a solution obtained by mixing 0.045 g of p-toluenesulfonic acid monohydrate and 18.9 g of ion exchange water was prepared. The solution was added dropwise to the flask over 15 minutes so that the temperature did not exceed 60° C. After the addition, the mixture was stirred and reacted at 60° C. The reaction progressed over time and gelation occurred.

[0113] <Stability over time> The viscosity and weight average molecular weight of the siloxane compositions of Examples and Comparative Examples were measured immediately after preparation and after storage at 40° C. for one week, and evaluated according to the following criteria. The viscosity was measured using an R115 type viscometer RE-105L (E type viscometer, manufactured by Toki Sangyo Co., Ltd.) (measurement temperature: 25° C.), and the weight average molecular weight was measured using the method described in the present specification. (Evaluation Criteria) 0: The increase in viscosity and weight average molecular weight is less than 15%; △: The increase in viscosity and weight average molecular weight is more than 15%; ×: Gelated.

[0114] [Table 1]

[0115] According to the Examples, it was confirmed that the method for producing a solvent-free siloxane composition of the present invention can produce a solvent-free siloxane composition that is excellent in stability over time. In Comparative Example 1, since gelation progressed, the viscosity and weight average molecular weight after storage for one week could not be measured. Industrial Applicability

[0116] The present invention can provide a method for producing a solvent-free siloxane composition that is solvent-free and has excellent stability over time.

Claims

1. A method for producing a solvent-free silicone composition, comprising the following steps (1), (2) and (3) in sequence: Process (1) A step of reacting a silane compound to prepare a siloxane compound having a silanol group at the end; Process (2) After adding the amide compound, dehydration with the orthoester and solvent evaporation are performed; Process (3) A step of dissolving the terminal silanol group-containing siloxane compound in an organic solvent and then adding a blocking agent to obtain a blocked siloxane compound.

2. The method for producing a solvent-free silicone composition according to claim 1, wherein: The silane compound comprises at least one of the following formula (1) and the group consisting of the following formula (2), formula (3) and formula (4), Si(A 1 )(A 2 ) a (OR 1 ) 3-a (1) In formula (1), A 1 represents a monovalent organic group having a free radical polymerizable double bond, A 2 represents an alkyl group or a silyl group, R 1 Represents an alkyl group; multiple R 1 can be the same or different; a is 0 or 1; Si(B 1 )(B 2 ) b (OR 2 ) 3-b (2) In formula (2), B 1 represents an alkyl group, B 2 Represents silyl group, R 2 Represents an alkyl group; multiple R 2 can be the same or different; b is 0 or 1; Si(C 1 )2(C 2 ) c (OR 3 ) 2-c (3) In formula (3), C 1 represents an alkyl group, C 2 Represents silyl group, R 3 Represents an alkyl group; two C 1 Can be the same or different, multiple R 3 Can be the same or different; c is 0 or 1; Si(D 1 )(D 2 ) d (OR 4 ) 3-d (4) In formula (4), D 1 represents a fluoroalkyl group having 3 to 13 fluorine atoms, D 2 represents an alkyl group, a silyl group or a monovalent organic group having a free radical polymerizable double bond, R 4 Represents an alkyl group; multiple R 4 They can be the same or different, and d is 0 or 1.

3. The method for producing a solvent-free silicone composition according to claim 2, wherein: The silane compound includes at least two selected from the group consisting of the formula (2), the formula (3) and the formula (4).

4. The method for producing a solvent-free silicone composition according to claim 3, wherein: The silane compounds include the formula (2) and the formula (3).

5. The method for producing a solvent-free silicone composition according to claim 1 or 2, wherein: When the mass ratio of the formula (1) is w1, the mass ratio of the formula (2) is w2, the mass ratio of the formula (3) is w3, and the mass ratio of the formula (4) is w4, w1 is 10~30, w2 is 0~90, w3 is 0~90, w4 is 0~90, w2+w3+w4 is 70~90.

6. The method for producing a solvent-free silicone composition according to claim 5, wherein: The mass ratio w1 in the above formula (1) is 20 or less.

7. The method for producing a solvent-free silicone composition according to claim 1 or 2, wherein: The capping agent is hexamethyldisilazane.

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