Solventless siloxane composition, and production method of siloxane compound

Abstract

To provide a solventless siloxane composition which is solventless, excellent in temporal stability, and has a low refractive index of a cured film.SOLUTION: A solventless siloxane composition includes a siloxane compound having a structural unit derived from formula (1), and a terminal silanol group stopped by at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethyamine, N-trimethlysilyl acetoamide, and N-(trimethylsilyl)dimethylamine, where the refractive index of a cured film is 1.45 or lower. (In the formula (1), A1 is a univalent organic group having a radical-polymerizable double bond, A2 is an alkyl group or a siloxy group, and R1 is an alkyl group. Plural R1s may be the same or different. a is 0 or 1.)SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a solventless siloxane composition and a method for producing a siloxane compound. [Background technology]

[0002] Various lens materials, planarizing films, and other coating materials are used in solid-state imaging devices such as charge coupled devices (CCDs) and complementary metal-oxide semiconductor (CMOS) image sensors, as well as in display substrates 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, depending on the application, alkali solubility is also required. It is known that a resin composition containing a siloxane compound is suitable for such requirements.

[0004] For example, Patent Document 1 discloses a composition for forming a low refractive index film, which contains a silicone resin obtained by hydrolysis and condensation of a mixed raw material containing two or more specific silane compounds. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-203059 A Summary of the Invention [Problem to be solved by the invention]

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

[0007] Moreover, the composition for forming a low refractive index film described in Patent Document 1 contains a solvent. In recent years, in view of environmental concerns, there has been a demand for solvent-free compositions for forming low refractive index films, and there is therefore room for further improvement. [Means for solving the problem]

[0008] The present invention relates to a solventless siloxane composition that contains a siloxane compound having a structural unit derived from the following formula (1) and at least one structural unit selected from the group consisting of the following formulas (2) to (4), and in which a terminal silanol group is blocked with at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine, and that satisfies the following conditions 1 and 2: [ka] (In formula (1), A 1 represents a monovalent organic group having a radically polymerizable double bond; A 2 is an alkyl group or a siloxy group, R 1 represents an alkyl group. 1 may be the same or different. a is 0 or 1. [ka] (In formula (2), B 1 is an alkyl group, B 2 is a siloxy group, R 2 represents an alkyl group. 2 may be the same or different. b is 0 or 1. [ka] (In formula (3), C 1 is an alkyl group, C 2 is a siloxy group, R 3 represents an alkyl group. 1 may be the same or different.3 may be the same or different. c is 0 or 1. [ka] (In formula (4), D 1 is a fluoroalkyl group having 3 to 13 fluorine atoms; D 2 is an alkyl group, a siloxy group or a monovalent organic group having a radical polymerizable double bond; R 4 represents an alkyl group. 4 may be the same or different. d is 0 or 1. [Condition 1] The refractive index of the cured coating is 1.45 or less. [Condition 2] The siloxane compound has a mass ratio of the structural unit derived from the above formula (1) to all structural units of w 1 , the mass ratio of the structural unit derived from the above formula (2) is w 2 , the mass ratio of the structural unit derived from the above formula (3) is w 3 , the mass ratio of the structural unit derived from the above formula (4) is w 4 When we say, w 1 10~30,w 2 is 0 to 90, w 3 is 0 to 90, w 4 is 0 to 90, w 2 +w 3+ w 4 is between 70 and 90.

[0009] In the solventless siloxane composition of the present invention, the siloxane compound preferably has structural units derived from at least two types selected from the group consisting of the above formulas (2) to (4). The siloxane compound preferably has structural units derived from the above formulas (2) and (3). In addition, the siloxane compound has a mass ratio w 1 It is preferable that the value is 20 or less. The siloxane compound preferably has a weight average molecular weight of 800 to 10,000. The present invention also relates to a method for producing a siloxane compound, comprising the following steps (1), (2), and (3) in this order: (Process 1) A step of reacting the following formula (1) with at least one compound selected from the group consisting of the following formulas (2) to (4) to prepare a siloxane compound having a silanol group at its terminal: [ka] (In formula (1), A 1 represents a monovalent organic group having a radically polymerizable double bond; A 2 is an alkyl group or a siloxy group, R 1 represents an alkyl group. 1 may be the same or different. a is 0 or 1. [ka] (In formula (2), B 1 is an alkyl group, B 2 is a siloxy group, R 2 represents an alkyl group. 2 may be the same or different. b is 0 or 1. [ka] (In formula (3), C 1 is an alkyl group, C 2 is a siloxy group, R 3 represents an alkyl group. 1 may be the same or different. 3 may be the same or different. c is 0 or 1. [ka] (In formula (4), D 1 is a fluoroalkyl group having 3 to 13 fluorine atoms; D 2 is an alkyl group, a siloxy group or a monovalent organic group having a radical polymerizable double bond; R 4 represents an alkyl group. 4 may be the same or different. d is 0 or 1. (Process 2) A step of adding an amide compound, followed by dehydration with an orthoester and distilling off the solvent (Step 3) A process of dissolving the above-mentioned terminal silanol group-containing siloxane compound in an organic solvent, and then adding at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine to obtain a blocked siloxane compound. Effect of the Invention

[0010] The present invention can provide a solventless siloxane composition that is stable over time and produces a cured coating with a low refractive index. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The solventless siloxane composition of the present invention has a structural unit derived from the following formula (1) and at least one structural unit selected from the group consisting of the following formulas (2) to (4), and contains a siloxane compound in which a terminal silanol group is blocked with at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine, and satisfies the following conditions 1 and 2. [ka] (In formula (1), A 1 represents a monovalent organic group having a radically polymerizable double bond; A 2 is an alkyl group or a siloxy group, R 1 represents an alkyl group. 1 may be the same or different. a is 0 or 1. [ka] (In formula (2), B 1 is an alkyl group, B 2 is a siloxy group, R 2 represents an alkyl group. 2 may be the same or different. b is 0 or 1. [ka] (In formula (3), C 1 is an alkyl group, C 2 is a siloxy group, R 3 represents an alkyl group. 1 may be the same or different. 3 may be the same or different. c is 0 or 1. [ka] (In formula (4), D 1 is a fluoroalkyl group having 3 to 13 fluorine atoms; D 2 is an alkyl group, a siloxy group or a monovalent organic group having a radical polymerizable double bond; R 4 represents an alkyl group. 4 may be the same or different. d is 0 or 1. [Condition 1] The refractive index of the cured coating is 1.45 or less. [Condition 2] The siloxane compound has a mass ratio of the structural unit derived from the above formula (1) to all structural units of w 1 , the mass ratio of the structural unit derived from the above formula (2) is w 2 , the mass ratio of the structural unit derived from the above formula (3) is w 3 , the mass ratio of the structural unit derived from the above formula (4) is w 4 When we say, w 1 10~30,w 2 is 0 to 90, w 3 is 0 to 90, w 4 is 0 to 90, w 2 +w 3+ w 4 is between 70 and 90.

[0012] (Siloxane compounds) The solventless siloxane composition of the present invention contains a siloxane compound. First, equation (1) will be explained.

[0013] [ka] (In formula (1), A 1 represents a monovalent organic group having a radically polymerizable double bond; A 2 is an alkyl group or a siloxy group, R 1 represents an alkyl group. 1 may be the same or different. a is 0 or 1.

[0014] In the above formula (1), A 1 is preferably a monovalent organic group having a vinyl group, an allyl group, or a (meth)acryloyl group.

[0015] In the above general formula (1), A 2 is preferably an alkyl group having 1 to 10 carbon atoms. Such an alkyl group is a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, a n-butyl group or a sec-butyl group.

[0016] In the above general formula (1), R 1 is preferably an alkyl group having 1 to 10 carbon atoms. Such an alkyl group is a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, a n-butyl group or a sec-butyl group.

[0017] In the above general formula (1), a is preferably 0.

[0018] Examples of the above general formula (1) include vinyl silane compounds such as vinyl trimethoxy silane, vinyl triethoxy silane, methyl vinyl dimethoxy silane, and methyl vinyl diethoxy silane; 3-(meth)acryloyloxy propyl methyl dimethoxy silane, 3-(meth)acryloyloxy propyl trimethoxy silane, 3-(meth)acryloyloxy propyl ethyl diethoxy silane, and 3-(meth)acryloyloxy propyl triethoxy silane; and allyl silane compounds such as allyl trimethoxy silane and allyl triethoxy silane.

[0019] Next, formula (2) will be explained.

[0020] [ka] (In formula (2), B 1 is an alkyl group, B 2 is a siloxy group, R 2 represents an alkyl group. 2 may be the same or different. b is 0 or 1.

[0021] In the above formula (2), B 1 is preferably an alkyl group having 1 to 10 carbon atoms. Such an alkyl group is a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, a n-butyl group or a sec-butyl group.

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

[0023] In the above formula (2), R 2 is preferably an alkyl group having 1 to 10 carbon atoms. Such an alkyl group is a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, a n-butyl group or a sec-butyl group.

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

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

[0026] Next, formula (3) will be explained.

[0027] [ka] (In formula (3), C 1 is an alkyl group, C 2 is a siloxy group, R 3 represents an alkyl group. 1 may be the same or different. 3 may be the same or different. c is 0 or 1.

[0028] In the above formula (3), C 1 is preferably an alkyl group having 1 to 10 carbon atoms. Such an alkyl group is a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, a n-butyl group or a sec-butyl group.

[0029] In the above formula (3), C 2 is a siloxy group.

[0030] In the above formula (3), R 3 is preferably an alkyl group having 1 to 10 carbon atoms. Such an alkyl group is a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, a n-butyl group or a sec-butyl group.

[0031] In the above formula (3), c is preferably 0.

[0032] Examples of the above formula (3) include dimethyldimethoxysilane and dimethyldiethoxysilane.

[0033] Equation (4) will now be explained.

[0034] [ka] (In formula (4), D 1 is a fluoroalkyl group having 3 to 13 fluorine atoms; D 2 is an alkyl group, a siloxy group or a monovalent organic group having a radical polymerizable double bond; R 4 represents an alkyl group. 4 may be the same or different. d is 0 or 1.

[0035] In the above formula (4), D 1 can be appropriately selected depending on the application of the coating of the solventless siloxane composition. For example, in order to reduce the refractive index, it is preferable to select the number of fluorines in the range of 9 to 13. Furthermore, for example, in order to reduce the refractive index while maintaining the hardness, it is preferable to select the number of fluorines in the range of 3 to 5.

[0036] In the above formula (4), D 2 is preferably an alkyl group having 1 to 10 carbon atoms. Such an alkyl group is a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, a n-butyl group or a sec-butyl group.

[0037] In the above formula (4), R 4 is preferably an alkyl group having 1 to 10 carbon atoms. Such an alkyl group is a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, a n-butyl group or a sec-butyl group.

[0038] In the above formula (4), d is preferably 0.

[0039] Examples of the above formula (4) include trifluoropropylmethyldimethoxysilane, trifluoropropylmethyldiethoxysilane, trifluoropropylmethyldipropoxysilane, trifluoropropylmethyldiisopropoxysilane, trifluoropropylethyldimethoxysilane, trifluoropropylethyldiethoxysilane, heptadecafluorodecylmethyldimethoxysilane, tridecafluorooctylmethyldimethoxysilane, tridecafluorooctylmethyldiethoxysilane, tridecafluorooctylmethyldipropoxysilane, tridecafluorooctylmethyldiisopropoxysilane, trifluoropropylvinyldimethoxysilane, trifluoropropylvinyldiethoxysilane, and trifluoropropyltrialkoxysilane.

[0040] The siloxane compound has a mass ratio of the structural unit derived from the above formula (1) to all structural units of w 1 , the mass ratio of the structural unit derived from the above formula (2) is w 2 , the mass ratio of the structural unit derived from the above formula (3) is w 3 , the mass ratio of the structural unit derived from the above formula (4) is w 4 When we say, w 1 10~30,w 2 is 0 to 90, w 3 is 0 to 90, w 4 is 0 to 90, w 2 +w 3+ w 4 is between 70 and 90. The mass ratio of the structural units derived from the above general formulas (1) to (4) is 29 Si-NMR and 1 It can be obtained by measuring by H-NMR.

[0041] The siloxane compound has a mass ratio w 1 is preferably 20 or less, and more preferably 15 or less.

[0042] From the viewpoint of reducing the viscosity of the siloxane composition of the present invention, the siloxane compound preferably has structural units derived from at least two types selected from the group consisting of the above formulas (2) to (4), and more preferably has structural units derived from the above formulas (2) and (3). It is preferable that the structural unit derived from the above formula (4) is not contained from the viewpoint of environmental load.

[0043] The siloxane compound has a mass ratio w 2 is preferably 0 to 90, and more preferably 30 to 80.

[0044] The siloxane compound has a mass ratio w 3 is preferably 0-90, and more preferably 5-30.

[0045] The siloxane compound has a mass ratio w 2 is preferably 50 or less, more preferably 10 or less, and even more preferably 0 from the viewpoint of environmental load.

[0046] The siloxane compound preferably has a weight average molecular weight (Mw) of 800 to 10,000. If the weight average molecular weight (Mw) is less than 800, the film-forming property and curing property of the solventless siloxane composition may be reduced. If the weight average molecular weight (Mw) is more than 10,000, the viscosity tends to be high. The siloxane compound has a weight average molecular weight (Mw) of more preferably 1,500 to 2,500, and further preferably 1,800 to 2,400.

[0047] The weight average molecular weight (Mw) can be measured by dissolving the siloxane compound to prepare a 0.02 part by mass solution, passing the solution through a filter (GL Sciences, GL Chromatodisk, aqueous 25A, pore size 0.2 μm), and then using Alliance (Nihon Waters) consisting of a size exclusion chromatograph and a refractive index detector under the following conditions. Column: pLgel mixed D (Agilent) x 2 connected in series Detector: alliance (manufactured by Japan Waters) Eluent: tetrahydrofuran (THF) Flow rate: 1.0 ml / min Injection volume: 100μl

[0048] (Method of producing siloxane compound) The present invention also relates to a method for producing a siloxane compound obtained by the following steps (1) to (3). (Process 1) A step of reacting the following formula (1) with at least one compound selected from the group consisting of the following formulas (2) to (4) to prepare a siloxane compound having a silanol group at its terminal: [ka] (In formula (1), A 1 represents a monovalent organic group having a radically polymerizable double bond; A 2 is an alkyl group or a siloxy group, R 1 represents an alkyl group. 1 may be the same or different. a is 0 or 1. [ka] (In formula (2), B 1 is an alkyl group, B 2 is a siloxy group, R 2 represents an alkyl group. 2 may be the same or different. b is 0 or 1. [ka] (In formula (3), C 1 is an alkyl group, C 2 is a siloxy group, R 3 represents an alkyl group. 1 may be the same or different. 3 may be the same or different. c is 0 or 1. [ka] (In formula (4), D 1 is a fluoroalkyl group having 3 to 13 fluorine atoms; D 2 is an alkyl group, a siloxy group or a monovalent organic group having a radical polymerizable double bond; R 4 represents an alkyl group. 4 may be the same or different. d is 0 or 1. (Process 2) A step of adding an amide compound, followed by dehydration with an orthoester and distilling off the solvent (Step 3) A process of dissolving the above-mentioned terminal silanol group-containing siloxane compound in an organic solvent, and then adding at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine to obtain a blocked siloxane compound.

[0049] By using the method for producing a siloxane compound of the present invention, the amount of protective reagent (at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine) used can be reduced, and a solvent-free siloxane compound that has excellent stability over time can be produced economically and stably.

[0050] The above step 1 is a step of reacting the above formula (1) with at least one compound selected from the group consisting of the above formulas (2) to (4) to prepare a siloxane compound having a silanol group at its terminal.

[0051] For the above formulas (1) to (4), the formulas (1) to (4) described above in relation to the siloxane compound can be used.

[0052] In the above step 1, for example, a method can be mentioned in which a polymerization catalyst is added to a solution prepared by dissolving the above general formulae (1) to (4) in an organic solvent in a suitable vessel, and the reaction is carried out under reflux.

[0053] As the organic solvent, preferred are lower alcohols such as ethanol, n-propyl alcohol, isopropyl alcohol, etc.; ketone compounds such as acetone, methyl ethyl ketone, etc.; and ester compounds such as ethyl acetate, n-propyl acetate, etc. Among these, lower alcohols are more preferred, and ethanol and isopropyl alcohol are even more preferred from the viewpoints of being able to maintain a moderate reaction temperature and being easy to distill off.

[0054] As the polymerization catalyst, for example, an acid catalyst such as acetic acid, hydrochloric acid, or paratoluenesulfonic acid monohydrate, or a base catalyst such as ammonia, triethylamine, cyclohexylamine, or tetramethylammonium hydroxide can be used.

[0055] The amount of the polymerization catalyst is preferably such that the number of molecules of the polymerization catalyst is about 0.05 to 0.2 times the number of all molecules of the above formulas (1) to (4).

[0056] The reaction temperature is preferably 60 to 80° C., and the reaction time is preferably about 2 to 24 hours so that the reaction proceeds sufficiently.

[0057] The above-mentioned step 2 is a step of adding an amide compound after the completion of step 1, followed by dehydration with an orthoester and distilling off the solvent. The above-mentioned step 2 can stabilize the terminal silanol group.

[0058] Examples of the amide compounds include N,N-dimethylacetamide and N,N-dimethylformamide.

[0059] The amount of the amide compound added is about 15 to 30% by mass based on the total mass of the siloxane compound.

[0060] After the amide compound is added, stirring is preferably carried out. The stirring temperature at this time is preferably 10 to 40° C., and the stirring time is preferably 0.5 to 1 hour.

[0061] Examples of the orthoester include triethyl orthoacetate, trimethyl orthoformate, and triethyl orthoformate. By using the above orthoester, the water generated by the reaction can be removed. When the orthoester is added dropwise, it is preferable to add the orthoester so that the temperature does not exceed 30° C. in order to prevent side reactions.

[0062] The method for distilling off the solvent is not particularly limited, and any known method, for example, distillation under reduced pressure, may be used.

[0063] The reaction between the siloxane compound and the amide compound makes it possible to stabilize the siloxane compound containing terminal silanol groups.

[0064] The above-mentioned step 3 is a step of dissolving the above-mentioned terminal silanol group-containing siloxane compound in an organic solvent, and then adding at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine in addition to at least one selected from the group consisting of acids, acid anhydrides, acid chlorides, and esters, to obtain a blocked siloxane compound.

[0065] As the organic solvent, any of the organic solvents described in step 1 above may be appropriately selected.

[0066] In the above step 3, it is preferable to add at least one selected from an acid, an acid anhydride, an acid chloride, and an ester, and then add a capping agent. The acids, acid anhydrides, acid chlorides and esters include acetic anhydride, acetic acid, succinic acid and the like.

[0067] The amount of at least one selected from the above acids, acid anhydrides, acid chlorides and esters added is about 50 to 100% by mass based on the total mass of the above protecting reagent. This makes it possible to remove ammonia, which is a by-product produced when sealing with the protective reagent. The step of adding at least one selected from the group consisting of an acid, an acid anhydride, an acid chloride and an ester can be omitted since ammonia is not by-produced depending on the type of the protecting reagent.

[0068] The protecting reagent may be at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine. Among these, hexamethyldisilazane is preferred from the viewpoint of cost. The amount of the protecting reagent added is preferably 70 to 150% by mass, and more preferably 80 to 100% by mass, based on the total mass of the siloxane compound.

[0069] In the above step 3, the reaction temperature is preferably 10 to 50° C. from the viewpoint of preventing side reactions.

[0070] In the above step 3, the reaction time is preferably about 3 to 15 hours so that the reaction proceeds sufficiently.

[0071] After the above step 3, it is preferable to remove by-products and residues, and to distill off the organic solvent and water.

[0072] The by-products and residues can be removed by known methods, for example, by neutralizing them or mixing them with water.

[0073] The organic solvent and water can be removed by distillation using a known method. For example, water can be removed by using sodium sulfate, or the solvent can be removed by drying under reduced pressure.

[0074] By distilling off the organic solvent and water, a solventless siloxane compound can be obtained.

[0075] (Solvent-free siloxane composition) The solventless siloxane composition of the present invention will now be described. In this specification, "solvent-free type" means that the mass loss after 2 hours at 160°C under reduced pressure (5 hectopascals or less) is less than 1%.

[0076] The solventless siloxane composition of the present invention may contain a leveling agent.

[0077] Examples of the leveling agent include silicone surfactants and fluorine surfactants. Among these, silicone-based surfactants are more suitable as the leveling agent in the present invention.

[0078] The content of the leveling agent is preferably 0.05 to 1 part by mass with respect to 100 parts by mass of the siloxane compound.

[0079] The solventless siloxane composition of the present invention may contain a photopolymerizable compound.

[0080] The photopolymerizable compound is preferably a photopolymerizable compound having a radically polymerizable unsaturated double bond.

[0081] Examples of the photopolymerizable compound having two or more radically polymerizable unsaturated double bonds include ester compounds of divalent or higher hydroxyl group-containing compounds and (meth)acrylic acid, such as 1,3-butylene glycol 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, dipropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tetrapropylene ... Examples of the acrylates include propylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, bisphenol A di(meth)acrylate, tris(2-hydroxyethyl)isocyanuric acid di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerin 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, and dipentaerythritol hexa(meth)acrylate.

[0082] Among these, from the viewpoint of being able to increase the crosslink density and impart excellent hardness to the cured coating, compounds having three or more reactive functional groups, for example, trimethylolpropane tri(meth)acrylate, glycerin 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, and dipentaerythritol hexa(meth)acrylate are preferred, with tris(2-hydroxyethyl)isocyanuric acid tri(meth)acrylate and dipentaerythritol hexa(meth)acrylate being more preferred.

[0083] The photopolymerizable compound is preferably contained in an amount of 10 to 50 parts by mass relative to 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 coating film and the adhesion to the light-transmitting substrate or ITO electrode may be insufficient, whereas if the content of the photopolymerizable compound is more than 50 parts by mass relative to 100 parts by mass of the siloxane compound, the solubility of the uncured coating film in a developer may be insufficient.

[0084] The solventless siloxane composition of the present invention may contain a polymerization initiator.

[0085] As the polymerization initiator, it is preferable to use a polymerization initiator that can provide a sufficient photocuring reaction when forming a cured coating.

[0086] Examples of the polymerization initiator include benzil, 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-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl-[4'-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and the like. Examples of such compounds include carbonyl compounds such as sphingoside oxides; trihalomethanes such as 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)-1,3,5-triazine and 2-[2-(2-furanyl)ethylenyl]-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, and 2,4-dichlorothioxanthone; and biguanide compounds such as 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidinium=2-(3-benzoylphenyl)propionate.

[0087] These polymerization initiators can be used alone or in combination of two or more kinds, and can also be combined with any photosensitizer. The siloxane compound may also be used in combination with a photoacid generator or a photobase generator as a catalyst for promoting the condensation reaction of the siloxane compound.

[0088] The polymerization initiator is preferably contained in an amount of 0.5 to 40 parts by mass when the total amount of the siloxane compound and the photopolymerizable compound is taken as 100 parts by mass.

[0089] If the content of the polymerization initiator is less than 0.5 parts by mass, the photopolymerizability may decrease, and unreacted components may remain in the exposed area of ​​the photolithography method. If the content of the polymerization initiator is more than 40 parts by mass, the storage stability of the solventless siloxane composition may decrease. The amount of the polymerization initiator is more preferably 1 to 20 parts by mass 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.

[0090] (Other materials) To the solventless siloxane composition of the present invention, there can be added, within the scope of not decreasing the effects of the present invention, chelate compounds of metals such as aluminum, zirconium, titanium, etc.; carbodiimide-based, isocyanate-based, and crosslinking agents having crosslinkable functional groups such as epoxy groups and thiol groups; silicone-based, fluorine-based, and other surfactants; photosensitizers such as aromatic hydrocarbon-based, amino compound-based, nitro compound-based, quinones, and xanthones; polymerization inhibitors such as hydroquinone, methoquinone, hindered amine-based, hindered phenol-based, di-t-butylhydroquinone, 4-methoxyphenol, butylhydroxytoluene, and nitrosamine salts; and fillers such as inorganic metal oxides and organic fine particles.

[0091] (Method for producing solventless siloxane composition) The method for producing the solventless siloxane composition of the present invention can be performed by charging an organic solvent into an appropriate container and, while stirring with, for example, a high-speed stirrer, charging and mixing the above-mentioned siloxane compound, if necessary the above-mentioned photopolymerizable compound having two or more radically polymerizable unsaturated double bonds, the above-mentioned polymerization initiator, and other materials. It should be noted that the method for producing the solventless siloxane composition of the present invention is not limited to the above method, and the order in which the materials are charged may be arbitrary. Furthermore, if a solid material is soluble in an organic solvent, it may be dissolved in advance before being charged, or if it is dispersible in an organic solvent directly or with the aid of a dispersant or the like, it may be dispersed in advance before being charged.

[0092] (Method for forming hardened film) A method for forming a cured coating using the solventless siloxane composition of the present invention preferably includes a coating step of coating a substrate with the solventless siloxane composition, an exposure step of irradiating an exposed area with active energy rays to form a cured coating, and a development step of dissolving and removing the coating liquid in the unexposed area with a developer. After the coating step, the composition may be thermally cured.

[0093] The coating method in the coating step, the active energy rays irradiated to the exposed area in the exposure step and the irradiation method thereof, and the developer for removing the coating liquid from the exposed area can be appropriately selected from those and methods used in conventional photolithography methods.

[0094] For example, the solventless siloxane composition is diluted so that the concentration of non-volatile components becomes 20% by mass, and then coated using a spin coater and heated (pre-baked) at 80°C for 3 minutes or the like. Then, using a mask aligner, the composition is heated at 100 mJ / cm 2 A test pattern is baked under the above irradiation conditions, immersed in a developer for 1 minute, and then heated (post-baked) at 150°C for 30 minutes, etc. to obtain a hardened coating. The pre-baking conditions are preferably 60 to 130° C. and 1 to 3 minutes. The above irradiation conditions are 50 to 260 mJ / cm 2 It is preferable that: The post-baking is preferably performed under conditions of 120 to 230° C. for 30 to 60 minutes.

[0095] The heat curing may be carried out, for example, by heating at 130° C. for 10 minutes and then at 180° C. for 60 minutes.

[0096] (Physical Properties of Solventless Siloxane Composition) The solventless siloxane composition of the present invention has excellent stability over time.

[0097] In this specification, the stability over time is evaluated by the following method.

[0098] The viscosity and weight average molecular weight of the solventless siloxane composition were compared immediately after preparation and after storage at 40°C for one week. If the increase in viscosity and weight average molecular weight is less than 15%, it is determined that the stability over time is excellent. The viscosity is measured (measurement temperature: 25° C.) using an R115 type viscometer RE-105L (E type viscometer, manufactured by Toki Sangyo Co., Ltd.), and the weight average molecular weight is measured by the method described above.

[0099] The solventless siloxane composition of the present invention forms a cured coating having a refractive index of 1.45 or less.

[0100] The refractive index of the cured coating is measured by the following method. A polymerization initiator (Omnirad184, manufactured by TIANJIN NEW MATERIALS) is dissolved in tetrahydrofuran (THF) in an amount of 5% by mass relative to the siloxane compound, and the tetrahydrofuran is removed by distillation under reduced pressure to prepare a solventless siloxane composition. Next, 1.5 g of the above solvent-free siloxane composition was applied to a glass substrate by spin coating at 3000 rpm for 60 seconds, and then the substrate was placed in a plastic bag, the air inside was replaced with nitrogen, and 365 nm UV light was applied at an integrated light intensity of 3000 mJ / cm. 2 The light is irradiated so as to form a hardened coating. Finally, the refractive index of the cured coating is measured at a wavelength of 550 nm using a microspectrophotometric film thickness meter OPTM series (manufactured by Otsuka Electronics Co., Ltd.). The thickness of the cured coating can also be measured using a microspectrophotometric coating thickness meter OPTM series (manufactured by Otsuka Electronics Co., Ltd.). The present specification discloses the following:

[0101] The present disclosure (1) is a solventless siloxane composition that contains a siloxane compound having a structural unit derived from the above formula (1) and a structural unit derived from at least one selected from the group consisting of the above formulas (2) to (4), and in which a terminal silanol group is blocked with at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine, and that satisfies the following conditions 1 and 2: [Condition 1] The refractive index of the cured coating is 1.45 or less. [Condition 2] The siloxane compound has a mass ratio of the structural unit derived from the above formula (1) to all structural units of w 1 , the mass ratio of the structural unit derived from the above formula (2) is w 2 , the mass ratio of the structural unit derived from the above formula (3) is w 3 , the mass ratio of the structural unit derived from the above formula (4) is w 4 When we say, w 1 10~30,w 2 is 0 to 90, w 3 is 0 to 90, w 4 is 0 to 90, w 2 +w 3+ w 4 is between 70 and 90. The present disclosure (2) is the solventless siloxane composition according to the present disclosure (1), in which the siloxane compound has structural units derived from at least two kinds selected from the group consisting of the above formulas (2) to (4). The present disclosure (3) is the solventless siloxane composition according to the present disclosure (1) or (2), in which the siloxane compound has structural units derived from the above formulas (2) and (3). The present disclosure (4) relates to a siloxane compound having a mass ratio w 1 The solventless siloxane composition according to any one of the present disclosures (1) to (3), wherein the value is 20 or less. The present disclosure (5) is the solventless siloxane composition according to any one of the present disclosures (1) to (4), wherein the siloxane compound has a weight average molecular weight of 800 to 10,000. The present disclosure (6) also relates to a method for producing a siloxane compound, the method comprising the following steps (1), (2), and (3) in this order: (Process 1) a step of reacting the above formula (1) with at least one compound selected from the group consisting of the above formulas (2) to (4) to prepare a siloxane compound having a silanol group at its terminal; (Process 2) A step of adding an amide compound, followed by dehydration and solvent distillation. (Step 3) This is a process in which the above-mentioned terminal silanol group-containing siloxane compound is dissolved in an organic solvent, and then at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine is added to obtain a blocked siloxane compound. EXAMPLES

[0102] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass."

[0103] The materials used in the examples and comparative examples are as follows.

[0104] (Compound of the above formula (1)) 3-Acryloxypropyltrimethoxysilane (Compound of the above formula (2)) Methyltriethoxysilane (Compound of the above formula (3)) Dimethyldimethoxysilane (Compound of the above formula (4)) Trifluoropropyltrimethoxysilane (Polymerization catalyst) Paratoluenesulfonic Acid Monohydrate (water) Ion-exchanged water (Amide compounds) N,N-Dimethylacetamide (ortho ester) Trimethyl orthoacetate (Protective Reagent) Hexamethyldisilazane Chlorotrimethylsilane

[0105] Example 1 73.2 g of methyltriethoxysilane, 12.4 g of dimethyldimethoxysilane, and 14.4 g of 3-acryloxypropyltrimethoxysilane were placed in a flask and stirred. On the other hand, a solution was prepared by mixing 0.055 g of paratoluenesulfonic acid monohydrate and 23.2 g of ion-exchanged water. The above solution was added dropwise to the above flask over 15 minutes so that the temperature did not exceed 60° C. After the addition, the mixture was stirred at a temperature of 60° C. for 3 hours (step 1). After cooling, 24.9 g of N,N-dimethylacetamide was added and stirred. Next, 32.5 g of trimethyl orthoacetate was added dropwise so that the temperature did not exceed 30° C. Then, the by-products methanol, ethanol, and water were removed by vacuum distillation to obtain a concentrated solution of a siloxane compound containing terminal silanol groups (step 2). 40.8 g of ethyl acetate and 35.0 g of acetic anhydride were added to the concentrated solution of the siloxane compound containing terminal silanol groups and stirred. Next, 61.4 g of hexamethyldisilazane was added dropwise so that the temperature did not exceed 30°C, to obtain a solution of the siloxane compound capped with hexamethyldisilazane (step 3). 40.8g of hexane and 40.8g of ion-exchanged water were added to the solution of the siloxane compound sealed with hexamethyldisilazane, and after stirring in a separatory funnel, the mixture was left to stand until it separated into an organic layer and an aqueous layer, after which the aqueous layer was removed. After removing the aqueous layer, separation was performed using ion-exchanged water and a saturated aqueous solution of sodium bicarbonate, and the organic layer was taken out. 10.0 g of sodium sulfate was added to the separated organic layer and stirred for 10 minutes to dehydrate it, after which the solution was filtered using a filter. Next, the solution was subjected to vacuum distillation at 60° C. for 1 hour, and then to vacuum distillation at 120° C. for another 3 hours to distill off low-boiling components other than the siloxane compound, thereby obtaining a solventless siloxane composition containing the siloxane compound. The mass ratio of the structural unit derived from formula (1) is w 1 , the mass ratio of the constituent units derived from formula (2) is w 2 , the mass ratio of the constituent units derived from formula (3) is w 3 , the mass ratio of the constituent units derived from formula (4) is w 4 The results are shown in Table 1.

[0106] (Examples 2 to 4, 6, Comparative Examples 1 to 2) A solventless siloxane composition was obtained in the same manner as in Example 1, except that the amounts of the various materials added were changed as shown in Table 1. In addition, Table 1 shows the amounts of the various materials used in the above step 1 and the amount of hexamethyldisilazane used in the above step 3. In addition, in Table 1, the mass ratio w 1 , mass ratio w 2 , mass ratio w 3 , mass ratio w 4 The following was shown.

[0107] Example 5 A solventless siloxane composition was obtained in the same manner as in Example 1, except that the amounts of various materials added were changed as shown in Table 1, the amount of hexamethyldisilazane dropped in step 2 was 76.9 g, and the amount of acetic anhydride added in step 3 was 43.8 g. In addition, Table 1 shows the amounts of the various materials used in the above step 1 and the amount of hexamethyldisilazane used in the above step 3. In addition, in Table 1, the mass ratio w 1 , mass ratio w 2 , mass ratio w 3 , mass ratio w 4 The following was shown.

[0108] Example 7 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 terminal silanol groups and stirred. Next, 66.8 g of chlorotrimethylsilane was added dropwise so that the temperature did not exceed 30°C, to obtain a solution of the siloxane compound sealed with chlorotrimethylsilane (step 3). A solventless siloxane composition containing a siloxane compound was obtained in the same manner as in Example 1 except for the above.

[0109] [Table 1]

[0110] <Stability over time> The siloxane compositions of the Examples and Comparative Examples were measured for viscosity and weight average molecular weight immediately after preparation and after storage at 40° C. for one week, and were evaluated according to the following criteria. The results are shown in Table 2. The viscosity was measured (measurement temperature: 25° C.) using an R115 type viscometer RE-105L (E type viscometer, manufactured by Toki Sangyo Co., Ltd.), and the weight average molecular weight was measured using the method described in this specification. (Evaluation Criteria) ○: The increase in viscosity and weight average molecular weight was less than 15%. △: Viscosity and weight average molecular weight increased by 15% or more ×: Gelled

[0111] <Measurement of refractive index and film thickness of cured film> For the siloxane compositions of the Examples and Comparative Examples, a polymerization initiator (Omnirad184, manufactured by TIANJIN NEW MATERIALS) was dissolved in tetrahydrofuran (THF) in an amount of 5% by mass relative to the siloxane compound, and the tetrahydrofuran was removed by distillation under reduced pressure. Next, 1.5 g of the above solvent-free siloxane composition was applied to a glass substrate by spin coating at 3000 rpm for 60 seconds, and then the substrate was placed in a plastic bag, the air inside was replaced with nitrogen, and 365 nm UV light was applied at an integrated light intensity of 3000 mJ / cm. 2 The cured coating was formed by irradiating the sample in such a manner that the cured coating was formed. Finally, the refractive index and thickness of the cured coating were measured at a wavelength of 550 nm using a microspectrophotometer OPTM series (manufactured by Otsuka Electronics Co., Ltd.). The results are shown in Table 2.

[0112] [Table 2]

[0113] From Table 2, it was confirmed that the solventless siloxane compositions of the examples had excellent stability over time and the cured coating had a low refractive index. [Industrial Applicability]

[0114] It is possible to provide a solvent-free siloxane composition that is solvent-free, has excellent stability over time, and produces a cured coating film with a low refractive index.

Claims

1. A structural unit derived from the following formula (1) and at least one structural unit derived from the group consisting of the following formulas (2) to (4), The present invention includes a siloxane compound in which a terminal silanol group is blocked with at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine, A solventless siloxane composition that satisfies the following conditions 1 and 2. 【Chemistry 1】 (In formula (1), A １ represents a monovalent organic group having a radically polymerizable double bond; ２ is an alkyl group or a siloxy group, R １ represents an alkyl group. １ may be the same or different. a is 0 or 1. 【Chemistry 2】 (In formula (2), B １ is an alkyl group, B ２ is a siloxy group, R ２ represents an alkyl group. ２ may be the same or different; b is 0 or 1. 【Chemistry 3】 (In formula (3), C １ is an alkyl group, C ２ is a siloxy group, R ３ represents an alkyl group. １ may be the same or different. ３ may be the same or different; c is 0 or 1. 【Chemistry 4】 (In formula (4), D １ represents a fluoroalkyl group having 3 to 13 fluorine atoms; D ２ is an alkyl group, a siloxy group or a monovalent organic group having a radical polymerizable double bond; R ４ represents an alkyl group. ４ may be the same or different. d is 0 or 1. [Condition 1] The refractive index of the cured coating is 1.45 or less. [Condition 2] The siloxane compound has a mass ratio of the structural unit derived from the formula (1) to all structural units of w １ The mass ratio of the structural unit derived from the formula (2) is w ２ The mass ratio of the structural unit derived from the formula (3) is w ３ , the mass ratio of the structural unit derived from the formula (4) is w ４ When W １ 10 to 30, w ２ is 0 to 90, w ３ is 0 to 90, w ４ is 0 to 90, w ２ +w ３＋ W ４ is between 70 and 90.

2. 2. The solventless siloxane composition according to claim 1, wherein the siloxane compound has structural units derived from at least two kinds selected from the group consisting of the formulas (2) to (4).

3. 3. The solventless siloxane composition according to claim 1, wherein the siloxane compound has structural units derived from the formulas (2) and (3).

4. The siloxane compound has a mass ratio w １ 3. The solventless siloxane composition according to claim 1, wherein the molecular weight is 20 or less.

5. 3. The solventless siloxane composition according to claim 1, wherein the siloxane compound has a weight average molecular weight of 800 to 10,000.

6. A method for producing a siloxane compound, comprising the following steps (1), (2), and (3) in this order: (Step 1) A step of reacting the following formula (1) with at least one compound selected from the group consisting of the following formulas (2) to (4) to prepare a siloxane compound having a silanol group at its terminal: 【Chemistry 5】 (In formula (1), A １ represents a monovalent organic group having a radically polymerizable double bond; ２ is an alkyl group or a siloxy group, R １ represents an alkyl group. １ may be the same or different. a is 0 or 1. 【Chemistry 6】 (In formula (2), B １ is an alkyl group, B ２ is a siloxy group, R ２ represents an alkyl group. ２ may be the same or different; b is 0 or 1. 【Chemistry 7】 (In formula (3), C １ is an alkyl group, C ２ is a siloxy group, R ３ represents an alkyl group. １ may be the same or different. ３ may be the same or different; c is 0 or 1. 【Chemistry 8】 (In formula (4), D １ represents a fluoroalkyl group having 3 to 13 fluorine atoms; D ２ is an alkyl group, a siloxy group or a monovalent organic group having a radical polymerizable double bond; R ４ represents an alkyl group. ４ may be the same or different. d is 0 or 1. (Step 2) A step of adding an amide compound, followed by dehydration with an orthoester and distilling off the solvent (Step 3) A process of dissolving the terminal silanol group-containing siloxane compound in an organic solvent, and then adding at least one selected from the group consisting of hexamethyldisilazane, chlorotrimethylsilane, trimethylsilyl acetate, N-(trimethylsilyl)diethylamine, N-trimethylsilylacetamide, and N-(trimethylsilyl)dimethylamine to obtain a blocked siloxane compound.

Images