Silane compound polymer, heat-curable composition, composition for fixing semiconductor element, and cured product

Abstract

To provide a silane compound polymer that is liquid at room temperature, and achieves both storage stability and heat curability in curing reaction, a heat-curable composition that contains the silane compound polymer, a composition for fixing a semiconductor element that comprises the heat-curable composition, and a cured product of the heat curable composition.SOLUTION: Provided are: a silane compound polymer having a repeating unit represented by the following formula (a-1) where R1 is an alkyl group having 3 or more carbon atoms, and a repeating unit represented by the following formula (a-2) where R2 is a fluoroalkyl group; a heat-curable composition containing the silane compound polymer; a composition for fixing a semiconductor element comprising the heat curable composition; and a cured product of the heat curable composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a silane compound polymer, a thermosetting composition, a semiconductor element fixing composition, and a cured product that are liquid at room temperature and have both storage stability and thermosetting properties during a curing reaction. [Background technology]

[0002] BACKGROUND ART Curable compositions have been improved in various ways depending on the intended use, and have been widely used industrially as raw materials for optical parts and molded articles, adhesives, coating agents, and the like. Furthermore, in recent years, curable compositions containing polysilsesquioxane compounds have been attracting attention because they form cured products that are excellent in heat resistance, transparency, and the like.

[0003] For example, Patent Documents 1 to 3 describe curable compositions containing polysilsesquioxane compounds and the use of the curable compositions as sealing materials. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-359933 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-263869 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-328231 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a demand for reducing the amount of solvent in curable compositions from the viewpoint of environmental issues, etc. For this reason, curable polysilsesquioxane compounds that are liquid at room temperature have attracted attention. Furthermore, in curable compositions that do not contain a solvent or that contain a small amount of solvent, reaction of the curable components during storage significantly affects the performance degradation of the curable composition, and therefore it is important that the curable polysilsesquioxane compound contained in the curable composition is stable at around room temperature.

[0006] The present invention has been made under these circumstances, and aims to provide a silane compound polymer that is liquid at room temperature and has both storage stability and thermosetting properties during a curing reaction; a thermosetting composition containing the silane compound polymer; a semiconductor element fixing composition comprising the thermosetting composition; and a cured product of the thermosetting composition. In the present invention, the term "thermosetting" in the context of a silane compound polymer or composition refers to the property of being cured by heating at about 150°C alone, even in the absence of a curing catalyst. [Means for solving the problem]

[0007] In order to solve the above problems, the present inventors have conducted extensive research on silane compound polymers. the result, (1) Silane compound polymers containing long-chain alkyl groups as side chains tend to have lower viscosities than those containing short-chain alkyl groups. (2) When the silane compound polymer containing a long-chain alkyl group as a side chain is a homopolymer, it tends to have poor storage stability and poor thermosetting properties during the curing reaction. (3) By introducing a repeating unit containing a fluoroalkyl group into a silane compound polymer containing a long-chain alkyl group as a side chain, storage stability and thermosetting property during a curing reaction are improved. The present invention has been completed based on the above findings.

[0008] Thus, according to the present invention, there are provided the following silane compound polymers [1] to [8], thermosetting compositions [9] to

[11] , a semiconductor element fixing composition

[12] , and a cured product

[13] .

[0009] [1] The following formula (a-1)

[0010] [ka]

[0011] [R 1 represents an alkyl group having 3 or more carbon atoms. A repeating unit represented by the formula (1) The following formula (a-2)

[0012] [ka]

[0013] [R 2 represents a fluoroalkyl group. and a silane compound polymer having a repeating unit represented by the following formula (2): [2] R 2 But the composition formula: C m H (2m-n+1) F n (wherein m represents an integer of 1 to 15, and n represents an integer of 2 or more and (2m+1) or less). [3] The silane compound polymer according to [1] or [2], wherein the ratio of the repeating unit (1) to the repeating unit (2) [repeating unit (1): repeating unit (2)] is 10:90 to 90:10 in molar ratio. [4] The silane compound polymer according to any one of [1] to [3], wherein the total amount of the repeating units (1) and (2) is 70 to 100 mol % based on the total amount of repeating units of the silane compound polymer. [5] The silane compound polymer according to any one of [1] to [4], which has a viscosity at 25°C of 12.0 Pa·s or less. [6] The silane compound polymer according to any one of [1] to [5], which has a mass average molecular weight (Mw) of 900 to 10,000. [7] The silane compound polymer according to any one of [1] to [6], wherein the rate of change in mass average molecular weight of the silane compound polymer is 90 to 200% when the silane compound polymer is allowed to stand at 40°C for 24 hours. [8] The silane compound polymer according to any one of [1] to [7], wherein the silane compound polymer has thermosetting properties. [9] A thermosetting composition containing the following components (A) and (B): Component (A): the silane compound polymer described in any one of [1] to [8] above Component (B): Silane coupling agent

[10] The thermosetting composition according to [9], wherein the content of the component (B) is 0.1 to 90 parts by mass per 100 parts by mass of the component (A).

[11] The thermosetting composition according to [9] or

[10] , which may or may not contain a solvent, and the content of the solvent is 10 mass% or less based on the total amount of the thermosetting composition.

[12] A semiconductor element fixing composition comprising the thermosetting composition according to any one of [9] to

[11] above.

[13] A cured product obtained by curing the thermosetting composition according to any one of [9] to

[11] above. [Effects of the Invention]

[0014] According to the present invention, there are provided a silane compound polymer that is liquid at room temperature (in this specification, room temperature means 25°C) and that has both storage stability and thermosetting properties during a curing reaction; a thermosetting composition containing this silane compound polymer; a semiconductor element fixing composition comprising this thermosetting composition; and a cured product of the thermosetting composition. DETAILED DESCRIPTION OF THE INVENTION

[0015] In this specification, for preferred numerical ranges (e.g., ranges of content, etc.), the lower and upper limits described in stages can be independently combined. For example, the description "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferable lower limit (10)" and the "more preferable upper limit (60)" to form "10 to 60."

[0016] The present invention will be described in detail below, divided into the following sections: 1) silane compound polymer, 2) thermosetting composition and semiconductor element fixing composition, and 3) cured product.

[0017] 1) Silane compound polymer The silane compound polymer of the present invention is a silane compound polymer having a repeating unit represented by the above formula (a-1) and a repeating unit represented by the above formula (a-2).

[0018] [Repeating units constituting silane compound polymer] The silane compound polymer of the present invention has a repeating unit represented by the following formula (a-1) [repeating unit (1)].

[0019] [ka]

[0020] In formula (a-1), R 1 represents an alkyl group having 3 or more carbon atoms. 1 The number of carbon atoms is preferably 3 to 20, more preferably 3 to 10, and even more preferably 3 to 6. R 1 may be a linear alkyl group or a branched alkyl group. Since a silane compound polymer having excellent thermosetting properties can be easily obtained, R 1 is preferably a straight chain alkyl group.

[0021] A silane compound polymer having the repeating unit (1) tends to have a low viscosity. By utilizing this property of the repeating unit (1), a silane compound polymer that is liquid at room temperature can be obtained.

[0022] R 1 Examples of the alkyl group include an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-nonyl group, and an n-decyl group. Among these, R 1 is preferably an n-propyl group.

[0023] The silane compound polymer of the present invention has a repeating unit represented by the following formula (a-2) [repeating unit (2)].

[0024] [ka]

[0025] In formula (a-2), R 2 represents a fluoroalkyl group.

[0026] When a silane compound polymer has only the repeating unit (1), the silane compound polymer tends to be poor in storage stability and thermosetting property during the curing reaction. The repeating unit (2) solves this problem, and by introducing the repeating unit (2) into a silane compound polymer having the repeating unit (1), the storage stability and thermosetting property during the curing reaction can be improved.

[0027] The reason why the introduction of the repeating unit (2) into a silane compound polymer having the repeating unit (1) improves the storage stability and the thermosetting property during the curing reaction is thought to be that the introduction of the repeating unit (2) moderately reduces the thermal reactivity of the silane compound polymer. That is, a silane compound polymer having too high thermal reactivity has sufficient reactivity even at around room temperature and loses its reactivity before the curing reaction of the thermosetting composition, whereas a silane compound polymer having an appropriately low thermal reactivity hardly reacts at around room temperature and can participate in the curing reaction of the thermosetting composition while retaining its original reactivity. In this way, it is believed that by appropriately reducing the reactivity of a silane compound polymer that has high thermal reactivity, a silane compound polymer that has both storage stability and thermosetting properties during the curing reaction can be obtained.

[0028] R 2 The composition formula is: C m H (2m-n+1) F n (wherein m represents an integer of 1 to 15, and n represents an integer of 2 or more and (2m+1) or less). In the above composition formula, m is preferably an integer of 1-10, and more preferably an integer of 3-8.

[0029] Composition formula: C m H (2m-n+1) F n Examples of the group represented by the formula (I) include perfluoroalkyl groups such as CF3-, CF3CF2-, CF3(CF2)2-, CF3(CF2)3-, CF3(CF2)4-, CF3(CF2)5-, CF3(CF2)6-, CF3(CF2)7-, CF3(CF2)8-, and CF3(CF2)9-; and hydrofluoroalkyl groups such as CF3CH2CH2-, CF3CF2CH2CH2-, CF3(CF2)2CH2CH2-, CF3(CF2)3CH2CH2-, CF3(CF2)4CH2CH2-, CF3(CF2)5CH2CH2-, CF3(CF2)6CH2CH2-, and CF3(CF2)7CH2CH2-.

[0030] Among these, R 2 is preferably CF3CH2CH2- (3,3,3-trifluoropropyl group).

[0031] In the silane compound polymer of the present invention, the molar ratio of the repeating unit (1) to the repeating unit (2) [repeating unit (1): repeating unit (2)] is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, and even more preferably 30:70 to 70:30. A silane compound polymer in which the ratio of the repeating unit (1) to the repeating unit (2) falls within the above range tends to be liquid at room temperature and to have excellent storage stability and thermosetting properties during the curing reaction.

[0032] In the silane compound polymer of the present invention, the total amount of the repeating units (1) and (2) is preferably 70 to 100 mol %, more preferably 80 to 100 mol %, and even more preferably 90 to 100 mol %, based on the total amount of repeating units in the silane compound polymer. A silane compound polymer in which the total amount of repeating units (1) and repeating units (2) is 70 mol % or more based on the total amount of repeating units of the silane compound polymer is liquid at room temperature and tends to have excellent storage stability and thermosetting properties during the curing reaction.

[0033] When the silane compound polymer of the present invention has a repeating unit other than the repeating unit (1) and the repeating unit (2) [repeating unit (3)], examples of the repeating unit (3) include repeating units derived from monofunctional silane compounds such as trimethylmethoxysilane, repeating units derived from difunctional silane compounds such as dimethyldimethoxysilane, repeating units derived from trifunctional silane compounds (excluding the repeating units (1) and (2)), and repeating units derived from tetrafunctional silane compounds such as tetramethoxysilane.

[0034] [Physical Properties of Silane Compound Polymer] As described above, the silane compound polymer of the present invention has the repeating unit (1) and is a liquid at room temperature. Therefore, the silane compound polymer of the present invention is suitably used as a curable component of a thermosetting composition that does not contain a solvent or that contains a small amount of solvent.

[0035] The viscosity of the silane compound polymer of the present invention at 25° C. is preferably 12.0 Pa·s or less, more preferably 10.0 Pa·s or less, and even more preferably 8.0 Pa·s or less. When the viscosity of the silane compound polymer of the present invention at 25° C. is 12.0 Pa·s or less, it becomes easier to obtain a thermosetting composition that does not contain a solvent or that contains a small amount of solvent.

[0036] There is no particular lower limit to the viscosity of the silane compound polymer of the present invention at 25° C., but it is usually 0.1 Pa·s or more. Therefore, the viscosity of the silane compound polymer of the present invention at 25° C. is preferably 0.1 to 12.0 Pa·s.

[0037] In this specification, the "viscosity at 25°C" of the silane compound polymer refers to the viscosity at 25°C at a shear rate of 2 s using a cone plate with a radius (radius of the cone base) of 25 mm and a cone angle of 0.5°. -1 This refers to the viscosity at

[0038] The mass average molecular weight (Mw) of the silane compound polymer of the present invention is preferably 900 to 10,000, more preferably 1,000 to 9,000, and even more preferably 1,200 to 8,000. The molecular weight distribution (Mw / Mn) of the silane compound polymer of the present invention is not particularly limited, but is usually 1.0 to 10.0, preferably 1.1 to 6.0. A silane compound polymer having a mass average molecular weight and a molecular weight distribution (Mw / Mn) within the above ranges is suitable for use as a low-viscosity curable component in a thermosetting composition. The mass average molecular weight (Mw) and number average molecular weight (Mn) can be determined, for example, as values ​​converted into standard polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0039] As described above, the silane compound polymer of the present invention has the repeating unit (1) and the repeating unit (2), and has excellent storage stability. The silane compound polymer of the present invention preferably has a mass average molecular weight change rate of 90 to 200%, more preferably 93 to 180%, and even more preferably 95 to 160% when allowed to stand at 40°C for 24 hours. As described above, the silane compound polymer of the present invention has excellent storage stability, and therefore is suitable as a curable component of a thermosetting composition that does not contain a solvent or has a small solvent content.

[0040] As described above, the silane compound polymer of the present invention has the repeating unit (1) and the repeating unit (2), and has excellent thermosetting properties during the curing reaction. When the silane compound polymer of the present invention is subjected to the thermosetting test described in the examples, it preferably has a time of 2,000 seconds or less, more preferably 1,000 seconds or less. There is no particular lower limit for the heat setting test result, but it is usually 30 seconds or more. Therefore, the silane compound polymer of the present invention preferably has a curing time of 30 to 2,000 seconds when subjected to the thermosetting test described in the examples. As described above, the silane compound polymer of the present invention has the property of being sufficiently cured by heating, and therefore the silane compound polymer of the present invention is suitable as a curable component of a thermosetting composition that does not contain a curing catalyst.

[0041] When the thermosetting composition is used for optical applications, the silane compound polymer contained in the thermosetting composition is preferably one that becomes a cured product having excellent heat yellowing resistance after curing. Such a silane compound polymer is preferably one in which R 1 This can be achieved by decreasing the number of carbon atoms in the repeating unit (1) or increasing the content of the repeating unit (2).

[0042] The silane compound polymer of the present invention may be any of a random copolymer, a block copolymer, a graft copolymer, an alternating copolymer, etc., but from the viewpoint of ease of production, etc., a random copolymer is preferred. The structure of the silane compound polymer of the present invention may be any of a ladder structure, a double-decker structure, a cage structure, a partially cleaved cage structure, a cyclic structure, and a random structure.

[0043] [Method for producing silane compound polymer] The method for producing the silane compound polymer of the present invention is not particularly limited. For example, the silane compound polymer of the present invention can be produced by carrying out a step (step PO) of hydrolyzing and polycondensing a trifunctional alkoxysilane compound corresponding to a desired repeating unit in the presence of water and an acid catalyst, and a step (step PU) of purifying the silane compound polymer obtained in step PO.

[0044] Step PO is a step of hydrolyzing and polycondensing a trifunctional alkoxysilane compound corresponding to a desired repeating unit in the presence of water and an acid catalyst.

[0045] In the step PO, for example, a compound represented by the following formula (a-3) and a compound represented by the following formula (a-4) are used as the trifunctional alkoxysilane compound.

[0046] [ka]

[0047] In formula (a-3) and formula (a-4), R 1 , R 2 represents the same meaning as above. OR represents an alkoxy group. OR may be the same or different.

[0048] The alkoxy group represented by OR preferably has 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms. Examples of the alkoxy group represented by OR include a methoxy group, an ethoxy group, and a propoxy group.

[0049] Specific examples of the trifunctional alkoxysilane compound represented by formula (a-3) include n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, s-butyltrimethoxysilane, s-butyltriethoxysilane, t-butyltrimethoxysilane, t-butyltriethoxysilane, n-pentyltrimethoxysilane, n-pentyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, n-nonyltrimethoxysilane, n-nonyltriethoxysilane, n-decyltrimethoxysilane, and n-decyltriethoxysilane. These trifunctional alkoxysilane compounds can be used alone or in combination of two or more.

[0050] Specific examples of the trifunctional alkoxysilane compound represented by formula (a-4) include trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, pentafluoroethyltrimethoxysilane, pentafluoroethyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 1H,1H,2H,2H-nonafluorohexyltrimethoxysilane, 1H,1H,2H,2H-nonafluorohexyltriethoxysilane, 1H,1H,2H,2H- Examples thereof include tridecafluorooctyltrimethoxysilane, 1H,1H,2H,2H-tridecafluorooctyltriethoxysilane, 1H,1H,2H,2H-heptadecafluorodecyltrimethoxysilane, 1H,1H,2H,2H-heptadecafluorodecyltriethoxysilane, [5,5,6,6,7,7,7-heptafluoro-4,4-bis(trifluoromethyl)heptyl]trimethoxysilane, and [5,5,6,6,7,7,7-heptafluoro-4,4-bis(trifluoromethyl)heptyl]triethoxysilane. These trifunctional alkoxysilane compounds can be used alone or in combination of two or more.

[0051] In the method for producing a silane compound polymer of the present invention, the molar ratio of the compound represented by formula (a-3) to the compound represented by formula (a-4) [compound represented by formula (a-3):compound represented by formula (a-4)] is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, and even more preferably 30:70 to 70:30.

[0052] In step PO, in addition to the above trifunctional alkoxysilane compounds, monofunctional alkoxysilane compounds such as trimethylmethoxysilane, bifunctional alkoxysilane compounds such as dimethyldimethoxysilane, trifunctional alkoxysilane compounds other than the compounds represented by formula (a-3) and formula (a-4), and tetrafunctional alkoxysilane compounds such as tetramethoxysilane may be used as monomers.

[0053] In the method for producing a silane compound polymer of the present invention, the total amount of the compound represented by formula (a-3) and the compound represented by formula (a-4) is preferably 70 to 100 mol %, more preferably 80 to 100 mol %, and even more preferably 90 to 100 mol %, based on the total amount of monomers.

[0054] In step PO, it is preferable to add water to the reaction system in an amount sufficient to sufficiently hydrolyze the hydrolyzable groups contained in the monomers (for example, "OR" in formula (a-3) and formula (a-4)).

[0055] The amount of water added is preferably such that the molar ratio M of water to alkoxy groups calculated by the following formula (F1) is 0.95 or more, more preferably 0.95 to 5.0, even more preferably 1.0 to 3.0, and particularly preferably 1.0 to 1.5.

[0056]

number

[0057] In formula (F1), M H2O is the amount of water (molar quantity) added to the reaction system, and M OR is the total number of alkoxy groups in the monomer (total number of moles). For example, when 3.0 mol of water is added to 1.0 mol of a trifunctional alkoxysilane compound, the value of the molar ratio M is 3.0 / 3.0 (=1.0).

[0058] When the molar ratio M is 0.95 or more, the hydrolysis reaction of the monomers can be sufficiently progressed, and a silane compound polymer having excellent thermosetting properties can be easily obtained.

[0059] Examples of the acid catalyst used in step (PO) include inorganic acids such as phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, and nitric acid; and organic acids such as formic acid, citric acid, acetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid. Among these, at least one selected from phosphoric acid, hydrochloric acid, boric acid, sulfuric acid, formic acid, citric acid, acetic acid, and methanesulfonic acid is preferred.

[0060] The amount of the acid catalyst used is usually 0.05 to 10 mol %, preferably 0.1 to 5 mol %, based on the total amount of the monomers. By adjusting the amount of the acid catalyst used, the polycondensation reaction can be allowed to proceed appropriately, and a silane compound polymer having the desired molecular weight can be obtained.

[0061] Step PO can be performed, for example, by placing a trifunctional alkoxysilane compound, water, and an acid catalyst in a reaction vessel and stirring the resulting mixture. In addition to these components, an organic solvent may also be present in the reaction vessel. Examples of organic solvents include aromatic hydrocarbons such as benzene, toluene, and xylene; esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and methyl propionate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, s-butyl alcohol, and t-butyl alcohol. These solvents can be used alone or in combination of two or more. When an organic solvent is used in step PO, the amount of the organic solvent used is preferably 0.05 to 3 times, more preferably 0.1 to 1.5 times, by volume, the amount of the trifunctional alkoxysilane compound.

[0062] The reaction conditions for step PO are not particularly limited. The reaction temperature in step PO is usually 0 to 85°C, preferably 5 to 75°C. The reaction time in step PO is usually 30 minutes to 50 hours, preferably 1 to 24 hours.

[0063] The process PO may be carried out under constant conditions from start to finish (i.e., it may have one step), or it may have multiple steps with different reaction conditions.

[0064] [Process PU] The step PU is a step of purifying the obtained silane compound polymer. By carrying out step PU, a high-purity silane compound polymer can be obtained, which is more suitable as a curable component of a thermosetting composition used for fixing semiconductor elements.

[0065] The process PU includes a purification process using a solvent extraction method. An example of a purification process using the solvent extraction method includes the following steps: (Step PU-I) A step of adding a water-immiscible organic solvent or water to the reaction mixture obtained in step PO as needed, stirring the mixture, and then allowing it to stand to separate into an organic phase and an aqueous phase. (Step PU-II) A step of separating and collecting the organic phase produced in Step PU-I, and washing the organic phase with water as needed. (Step PU-III) A step of concentrating and drying the organic phase separated in Step PU-II

[0066] In step PU-I, a solvent such as a water-immiscible organic solvent or water is added to the reaction mixture obtained in step PO as needed so that the reaction mixture separates into an organic phase and an aqueous phase. The amount of solvent added and the type of organic solvent are not particularly limited, as long as the reaction mixture obtained in step PO separates into an organic phase and an aqueous phase.

[0067] The silane compound polymer is usually contained in the organic phase. Therefore, in step PU-II, the organic phase produced in step PU-I is separated and collected. Thereafter, the organic phase may be washed with water according to a conventional method.

[0068] Step PU-III can be carried out by a conventional method such as concentration treatment with an evaporator and vacuum drying treatment.

[0069] 2) Thermosetting composition and semiconductor element fixing composition The thermosetting composition of the present invention contains the following components (A) and (B): Component (A): the silane compound polymer of the present invention Component (B): Silane coupling agent

[0070] [Component (A): Silane Compound Polymer of the Present Invention] The component (A) constituting the thermosetting composition of the present invention is the silane compound polymer of the present invention. The content of component (A) is preferably 50% by mass or more, more preferably 60% by mass or more, based on the total amount of components constituting the thermosetting composition (excluding the solvent). There is no upper limit, but it is usually 95% by mass or less, more preferably 90% by mass or less. Therefore, the content of the component (A) is preferably 50 to 95 mass % based on the total amount of components (excluding the solvent) that constitute the thermosetting composition.

[0071] [Component (B): Silane Coupling Agent] The component (B) that constitutes the thermosetting composition of the present invention is a silane coupling agent. A cured product of a thermosetting composition containing a silane coupling agent tends to have superior adhesive strength at room temperature and at high temperatures.

[0072] The silane coupling agent refers to a silane compound having a silicon atom, a functional group, and a hydrolyzable group bonded to the silicon atom. The functional group refers to a group that has reactivity with other compounds (mainly organic substances), and examples thereof include a vinyl group, an allyl group, an epoxy group, an amino group, a substituted amino group, an acrylic group, a methacrylic group, a mercapto group, an isocyanate group, a group having an isocyanurate structure, a group having a urea structure, and a group having an acid anhydride structure. The component (B) can be used alone or in combination of two or more.

[0073] The content of the component (B) in the thermosetting composition of the present invention is preferably 0.1 to 90 parts by mass, more preferably 0.3 to 60 parts by mass, even more preferably 1 to 50 parts by mass, and particularly preferably 3 to 40 parts by mass, per 100 parts by mass of the component (A). A cured product of a thermosetting composition in which the amount of component (B) is 0.1 part by mass or more per 100 parts by mass of component (A) tends to have superior adhesive strength at room temperature and at high temperatures. A thermosetting composition containing 90 parts by mass or less of the component (B) per 100 parts by mass of the component (A) tends to be less susceptible to cracking due to by-products such as alcohol during the curing reaction.

[0074] As the silane coupling agent, a silane coupling agent having a nitrogen atom in the molecule and a silane coupling agent having an acid anhydride structure in the molecule are preferred.

[0075] Examples of silane coupling agents having a nitrogen atom in the molecule include trialkoxysilane compounds represented by the following formula (b-1), dialkoxyalkylsilane compounds or dialkoxyarylsilane compounds represented by the following formula (b-2), and the like.

[0076] [ka]

[0077] In the above formula, R a represents an alkoxy group having 1 to 6 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, or a t-butoxy group. a They may be the same or different. R b represents an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a t-butyl group; or an aryl group having or having no substituent, such as a phenyl group, a 4-chlorophenyl group, a 4-methylphenyl group, or a 1-naphthyl group.

[0078] R c represents an organic group having a nitrogen atom and having 1 to 10 carbon atoms. c may further be bonded to another group containing a silicon atom. R c Specific examples of the organic group having 1 to 10 carbon atoms include an N-(2-aminoethyl)-3-aminopropyl group, a 3-aminopropyl group, an N-(1,3-dimethyl-butylidene)-3-aminopropyl group, a 3-ureidopropyl group, and an N-phenyl-3-aminopropyl group.

[0079] Among the compounds represented by the above formula (b-1) or formula (b-2), R cIn the case where the silane coupling agent is an organic group bonded to another silicon atom-containing group, examples of the compound include an isocyanurate-based silane coupling agent bonded to another silicon atom via an isocyanurate skeleton, and a urea-based silane coupling agent bonded to another silicon atom via a urea skeleton.

[0080] Among these, as silane coupling agents having a nitrogen atom in the molecule, isocyanurate-based silane coupling agents and urea-based silane coupling agents are preferred because they tend to give cured products with superior adhesive strength, and furthermore, those having four or more alkoxy groups bonded to silicon atoms in the molecule are preferred. "Having four or more alkoxy groups bonded to a silicon atom" means that the total number of alkoxy groups bonded to the same silicon atom and alkoxy groups bonded to different silicon atoms is four or more.

[0081] Examples of isocyanurate-based silane coupling agents having four or more alkoxy groups bonded to silicon atoms include compounds represented by the following formula (b-3): Examples of urea-based silane coupling agents having four or more alkoxy groups bonded to silicon atoms include compounds represented by the following formula (b-4):

[0082] [ka]

[0083] In the formula, R a has the same meaning as above. t1 to t5 each independently represent an integer of 1 to 10, preferably an integer of 1 to 6, and particularly preferably 3.

[0084] Among these, as the silane coupling agent having a nitrogen atom in the molecule, it is preferable to use 1,3,5-N-tris(3-trimethoxysilylpropyl)isocyanurate, 1,3,5-N-tris(3-triethoxysilylpropyl)isocyanurate (hereinafter referred to as "isocyanurate compound"), N,N'-bis(3-trimethoxysilylpropyl)urea, N,N'-bis(3-triethoxysilylpropyl)urea (hereinafter referred to as "urea compound"), and combinations of the above-mentioned isocyanurate compounds and urea compounds.

[0085] When the thermosetting composition of the present invention contains a silane coupling agent having a nitrogen atom in the molecule, the content thereof is not particularly limited, but the amount thereof is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less, per 100 parts by mass of the component (A). There is no particular lower limit for the content of the silane coupling agent having a nitrogen atom in the molecule, but it is preferably at least 0.1 part by mass, more preferably at least 0.3 part by mass, and even more preferably at least 1 part by mass per 100 parts by mass of component (A). Therefore, the content of the silane coupling agent having a nitrogen atom in the molecule is preferably 0.1 to 60 parts by mass per 100 parts by mass of the component (A).

[0086] Silane coupling agents having an acid anhydride structure in the molecule are organosilicon compounds that have both a group having an acid anhydride structure and a hydrolyzable group in one molecule.Specific examples include compounds represented by the following formula (b-5).

[0087] [ka]

[0088] In the formula, Q represents a group having an acid anhydride structure, and R d represents an alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted phenyl group, and R erepresents an alkoxy group having 1 to 6 carbon atoms or a halogen atom, i and k represent integers of 1 to 3, j represents an integer of 0 to 2, and i+j+k=4. When j is 2, R d When k is 2 or 3, multiple R e When i is 2 or 3, multiple Qs may be the same or different. Q is expressed by the following formula:

[0089] [ka]

[0090] (wherein h represents an integer of 0 to 10), and the group represented by (Q1) is particularly preferred.

[0091] Examples of silane coupling agents having an acid anhydride structure in the molecule include tri(C1-C6)alkoxysilyl(C2-C8)alkyl succinic anhydrides, such as 2-(trimethoxysilyl)ethyl succinic anhydride, 2-(triethoxysilyl)ethyl succinic anhydride, 3-(trimethoxysilyl)propyl succinic anhydride, and 3-(triethoxysilyl)propyl succinic anhydride; Di(C1-C6)alkoxymethylsilyl(C2-C8)alkyl succinic anhydrides such as 2-(dimethoxymethylsilyl)ethyl succinic anhydride; (C1-C6)alkoxydimethylsilyl(C2-C8)alkyl succinic anhydrides such as 2-(methoxydimethylsilyl)ethyl succinic anhydride;

[0092] Trihalogenosilyl (C2-C8) alkyl succinic anhydrides such as 2-(trichlorosilyl)ethyl succinic anhydride and 2-(tribromosilyl)ethyl succinic anhydride; Dihalogenomethylsilyl (C2-C8) alkyl succinic anhydrides such as 2-(dichloromethylsilyl)ethyl succinic anhydride; halogenodimethylsilyl (having 2 to 8 carbon atoms) alkyl succinic anhydrides such as 2-(chlorodimethylsilyl)ethyl succinic anhydride; and the like.

[0093] Among these, as the silane coupling agent having an acid anhydride structure in the molecule, tri(C1 to C6)alkoxysilyl(C2 to C8)alkyl succinic anhydride is preferred, and 3-(trimethoxysilyl)propyl succinic anhydride or 3-(triethoxysilyl)propyl succinic anhydride is particularly preferred.

[0094] When the thermosetting composition of the present invention contains a silane coupling agent having an acid anhydride structure in the molecule, the content thereof is not particularly limited, but the amount is preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the component (A). There is no particular lower limit for the content of the silane coupling agent having an acid anhydride structure in the molecule, but it is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of component (A). Therefore, the content of the silane coupling agent having an acid anhydride structure in the molecule is preferably 0.1 to 30 parts by mass per 100 parts by mass of the component (A).

[0095] 〔solvent〕 The thermosetting composition of the present invention preferably does not contain a solvent or contains a small amount of solvent. The content of the solvent is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0% by mass, based on the total amount of the thermosetting composition.

[0096] [Other ingredients] The thermosetting composition of the present invention may contain components other than those described above, provided that the object of the present invention is not impaired. In addition to the above, other components include additives such as fine particles, antioxidants, ultraviolet absorbers, and light stabilizers. The content of these additives can be determined appropriately depending on the purpose.

[0097] [Thermosetting composition] The thermosetting composition of the present invention can be prepared, for example, by mixing the above-mentioned components (A) and (B), and, if desired, other components, in predetermined proportions, followed by defoaming. The mixing method and degassing method are not particularly limited, and known methods can be used.

[0098] The thermosetting composition of the present invention contains the silane compound polymer of the present invention. The silane compound polymer of the present invention is liquid at room temperature and has excellent storage stability, so the thermosetting composition of the present invention is less likely to experience problems caused by reducing the amount of solvent. Furthermore, the silane compound polymer of the present invention has excellent thermosetting properties during the curing reaction, so excessive heating is not required when using the thermosetting composition of the present invention. Furthermore, because the silane compound polymer of the present invention contains fluorine atoms, the thermosetting composition of the present invention and its cured product tend to have a low refractive index. Thermosetting compositions with a low refractive index may be suitable as raw materials for producing optical-related components.

[0099] The thermosetting composition of the present invention contains a silane coupling agent. Therefore, when the thermosetting composition of the present invention is used as an adhesive, it can firmly bond adherends together even if the bonding area is small.

[0100] Because of these properties, the thermosetting composition of the present invention is suitably used as a semiconductor element fixing composition. Examples of the semiconductor element fixing composition include an adhesive for fixing a semiconductor element and a sealant for fixing a semiconductor element. Examples of semiconductor elements include light-emitting elements such as light-emitting diodes (LEDs) and laser diodes (LDs); light-receiving elements such as photodiodes, solar cells, and CMOS image sensors; composite optical elements; integrated circuits; and large-scale integrated circuits.

[0101] When the thermosetting composition of the present invention is used as a semiconductor element fixing composition, the thermosetting composition of the present invention is usually cured by heating. The heating temperature when the thermosetting composition of the present invention is heat-cured is usually 100 to 200° C. The heating time is usually 10 minutes to 20 hours, preferably 30 minutes to 10 hours.

[0102] [Adhesive for fixing semiconductor elements] When the thermosetting composition of the present invention is used as an adhesive for fixing a semiconductor element, a predetermined amount of the thermosetting composition of the present invention is usually applied to one or both bonding surfaces of the materials to be bonded (such as a semiconductor element and a substrate), pressed together, and then heated and cured. This process allows the materials to be firmly bonded together.

[0103] Materials constituting the substrate include glasses such as soda lime glass and heat-resistant hard glass; ceramics; sapphire; metals such as iron, copper, aluminum, gold, silver, platinum, chromium, titanium and alloys of these metals, and stainless steel (SUS302, SUS304, SUS304L, SUS309, etc.); and synthetic resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ethylene-vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyether ether ketone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyimide, polyamide, acrylic resin, norbornene-based resin, cycloolefin resin, and glass epoxy resin.

[0104] [Sealant for fixing semiconductor elements] When the thermosetting composition of the present invention is used as a sealant for fixing a semiconductor element, the thermosetting composition of the present invention is usually molded into a desired shape to obtain a molded product containing a semiconductor element, which is then heat-cured to obtain a semiconductor element-encapsulated product. The method for molding the thermosetting composition of the present invention into a desired shape is not particularly limited, and known molding methods such as ordinary transfer molding and casting can be used.

[0105] 3) Cured product The cured product of the present invention is obtained by curing the thermosetting composition of the present invention. The thermosetting composition of the present invention can be cured by heat curing. The heating temperature when the thermosetting composition of the present invention is heat-cured is usually 100 to 200° C. The heating time is usually 10 minutes to 20 hours, preferably 30 minutes to 10 hours.

[0106] The cured product of the present invention is obtained by curing a thermosetting composition containing the silane compound polymer of the present invention, and is therefore firmly fixed to the adherend. [Example]

[0107] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0108] Example 1 (Synthesis of silane compound polymer) A 300 ml eggplant-shaped flask was charged with 60 mmol (9.86 g) of n-propyltrimethoxysilane and 140 mmol (30.55 g) of 3,3,3-trifluoropropyltrimethoxysilane, and then, while stirring, an aqueous hydrochloric acid solution [600 mmol (10.8 g) of purified water to which 0.02 g of 35 mass% hydrochloric acid (0.1 mol% relative to the total amount of silane compounds) was added], and the total volume was stirred at 15°C for 1.25 hours, then the temperature was raised to 30°C and the mixture was stirred for 0.5 hours. Thereafter, 0.5 g of purified water and an amount (38 g) of propyl acetate such that the concentration of the silane compounds became 45 mass% were added, and stirring was continued for 0.5 hours. Next, purified water was added to the reaction solution, followed by separation and removal of the aqueous phase. These steps were repeated until the pH of the aqueous phase reached 7, after which the organic phase containing the reaction product was separated and concentrated using an evaporator. The concentrate was dried in vacuo to obtain 26.3 g of a silane compound polymer.

[0109] (Preparation of Thermosetting Composition) To 100 parts by mass of the obtained silane compound polymer, 30 parts by mass of 1,3,5-N-tris[3-(trimethoxysilyl)propyl]isocyanurate and 3 parts by mass of 3-(trimethoxysilyl)propylsuccinic anhydride were added, and the mixture was stirred to obtain a thermosetting composition.

[0110] [Examples 2 to 5, Comparative Examples 1 to 6] A silane compound polymer was synthesized in the same manner as in Example 1, except that the silane compounds having organic groups shown in Table 1 were used as monomers in the molar ratios shown in Table 1 (however, the total amount of the silane compounds was 200 mmol), and then a thermosetting composition was obtained. In Table 1, "trifluoropropyl group" means a 3,3,3-trifluoropropyl group, and "tridecafluorooctyl group" means a 1H,1H,2H,2H-tridecafluoro-n-octyl group.

[0111] The following measurements were carried out on the silane compound polymers obtained in Examples 1 to 5 and Comparative Examples 1 to 6. The results are shown in Table 1.

[0112] [Viscosity measurement] Using a rheometer (Anton Paar: MCR302) with a cone plate having a radius of 25 mm and a cone angle of 0.5°, the test was performed at 25°C for 2 seconds. -1 The viscosity at this time was measured.

[0113] [Average molecular weight measurement] The mass average molecular weight (Mw) of the silane compound polymer was measured using the following device under the following conditions. Device name: Tosoh Corporation: HLC-8220GPC Column: "TSK guard column SuperH-H", "TSK gel SuperHM-H", "TSK gel SuperHM-H", and "TSK gel SuperH2000" connected in sequence Solvent: tetrahydrofuran Standard material: polystyrene Injection volume: 20μl Measurement temperature: 40℃ Flow rate: 0.6ml / min Detector: differential refractometer

[0114] [Storage Stability Evaluation] The silane compound polymer was placed in a screw tube and allowed to stand in a thermostatic oven at 40°C for 24 hours. After standing, the mass average molecular weight of the silane compound polymer was measured using the same method as above, and the molecular weight change rate X was calculated using the following formula. The smaller the molecular weight change rate X, the better the storage stability. The results are shown in Table 1.

[0115]

number

[0116] (Mw(a) represents the mass average molecular weight after standing at 40°C for 24 hours, and Mw(b) represents the mass average molecular weight before standing at 40°C for 24 hours.)

[0117] [Evaluation of thermosetting properties] The curing time was measured under the following conditions using an automatic curing time measuring device (Madoka, manufactured by Cyber ​​Corporation). 0.2 mL of silane compound polymer was placed on a stainless steel plate heated to 150°C and stirred. The stirring torque increased over time, and the time (s) until it reached 0.098 N·cm was measured. The stirring conditions were as follows: Rotation speed of stirring blade: 300 rpm Rotation speed of stirring blade: 120 rpm Gap (distance between heating plate and stirring blade): 0.2 mm

[0118] [Evaluation of Heat Yellowing Resistance] The silane compound polymer coating was heated and cured at 150°C for 3 hours to obtain a 1 mm thick test piece. The transmittance of this test piece was measured using a UV-visible spectrophotometer, and then the test piece was heated at 200°C for 100 hours. After cooling to room temperature, the transmittance of the test piece was measured again, and the heat yellowing resistance Y was evaluated according to the following formula:

[0119]

number

[0120] (T(a) represents the transmittance at 450 nm after heating at 200°C for 100 hours, and T(b) represents the transmittance at 450 nm before heating at 200°C for 100 hours.)

[0121] The following measurements were carried out on the thermosetting compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 6. The results are shown in Table 1.

[0122] [Refractive index measurement] The thermosetting composition was discharged onto a horizontal surface, and the measurement surface of a pen refractometer (PEN-RI manufactured by ATAGO) was pressed onto the discharged composition at 25° C. to measure the refractive index (nD).

[0123] [Adhesion strength measurement (shear strength)] 2mm square (area 4mm 2 The thermosetting composition was applied to the mirror surface of a silicon chip (1.5 mm thick) to a thickness of approximately 2 μm, and the coated surface was placed on an adherend (silver-plated copper plate) and pressed against it. The composition was then cured by heat treatment at 170°C for 2 hours to obtain an adherend with a test piece attached. This adherend with the test piece attached was left for 30 seconds on the measurement stage of a bond tester (Daisi: Series 4000) that had been preheated to 100°C, and stress was applied to the adhesive surface in the horizontal direction (shear direction) at a speed of 200 μm / s from a position 100 μm above the adherend, and the adhesive strength (N / 4 mm) between the test piece and adherend at 100°C was measured. 2 The results are shown in Table 1.

[0124] [Table 1]

[0125] The following can be seen from the above examples and comparative examples. The silane compound polymers of Comparative Examples 1 to 4 are homopolymers of alkyltrialkoxysilanes having an alkyl group having 3 or more carbon atoms (n-propyl, isobutyl, n-hexyl, or n-decyl). These silane compound polymers have low viscosity at 25°C. Therefore, by using these silane compound polymers as a curable component of a thermosetting composition, the amount of solvent can be reduced. However, these silane compound polymers are inferior in at least one of storage stability and thermosetting property.

[0126] On the other hand, the silane compound polymers of Examples 1 to 5 are copolymers of an alkyltrialkoxysilane having an alkyl group with 3 or more carbon atoms and a fluoroalkyltrialkoxysilane. These silane compound polymers have low viscosity comparable to that of the homopolymers of Comparative Examples 1 to 4, and are excellent in storage stability and thermosetting properties. In this way, by using a fluoroalkyltrialkoxysilane as a monomer, a silane compound polymer can be obtained that is liquid at room temperature and has both storage stability and thermosetting properties during the curing reaction.

[0127] However, even when a fluoroalkyltrialkoxysilane is used as a monomer, when it is combined with an alkyltrialkoxysilane having an alkyl group having two or less carbon atoms, the effects of the present invention cannot be obtained, and a silane compound polymer having high viscosity is produced (Comparative Example 5) or a silane compound polymer having poor storage stability is produced (Comparative Example 6). Thus, in order to obtain the effects of the present invention, it is important to combine an alkyltrialkoxysilane having an alkyl group with 3 or more carbon atoms with a fluoroalkyltrialkoxysilane.

Claims

1. The following formula (a-1) 【Chemical 1】 [R １ represents an alkyl group having 3 or more carbon atoms. A repeating unit represented by the formula (1) [repeating unit (1)] The following formula (a-2) 【Chemistry 2】 [R ２ represents a fluoroalkyl group. and a repeating unit represented by the formula (2):

2. R ２ The composition formula: C ｍ H （２ｍ－ｎ＋１） F ｎ 2. The silane compound polymer according to claim 1, wherein m is an integer of 1 to 15, and n is an integer of 2 or more and (2m+1) or less.

3. 2. The silane compound polymer according to claim 1, wherein the molar ratio of the repeating unit (1) to the repeating unit (2) [repeating unit (1): repeating unit (2)] is 10:90 to 90:

10.

4. 2. The silane compound polymer according to claim 1, wherein the total amount of the repeating units (1) and (2) is 70 to 100 mol % based on the total amount of repeating units in the silane compound polymer.

5. 2. The silane compound polymer according to claim 1, which has a viscosity at 25°C of 12.0 Pa·s or less.

6. 2. The silane compound polymer according to claim 1, having a mass average molecular weight (Mw) of 900 to 10,000.

7. 2. The silane compound polymer according to claim 1, wherein the rate of change in mass average molecular weight of the silane compound polymer is 90 to 200% when the silane compound polymer is allowed to stand at 40° C. for 24 hours.

8. The silane compound polymer according to claim 1, wherein the silane compound polymer has thermosetting properties.

9. A thermosetting composition comprising the following components (A) and (B): Component (A): the silane compound polymer according to claim 1 Component (B): Silane coupling agent

10. 10. The thermosetting composition according to claim 9, wherein the content of the component (B) is 0.1 to 90 parts by mass per 100 parts by mass of the component (A).

11. The thermosetting composition according to claim 9 , which may or may not contain a solvent, and the content of the solvent is 10 mass % or less based on the total amount of the thermosetting composition.

12. A semiconductor element fixing composition comprising the thermosetting composition according to claim 9.

13. A cured product obtained by curing the thermosetting composition according to claim 9.

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