Addition-curable silicone composition and optical semiconductor device
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-04
- Publication Date
- 2026-08-13
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Abstract
Description
Addition-curing silicone composition and optoelectronic device
[0001] The present invention relates to an addition-curing silicone composition and an optoelectronic device.
[0002] Silicone resins, which are thermosetting resins, are being considered as materials for optoelectronic devices due to their excellent heat resistance, light resistance, and discoloration resistance. Furthermore, by mixing specific inorganic fillers with silicone resin, it is possible to impart properties such as high heat dissipation, high reflectivity, and high moisture resistance.
[0003] However, when silicone resin and inorganic fillers are mixed, the high proportion of inorganic fillers often degrades the mechanical properties of the silicone resin, and simultaneously reduces the fluidity of the composition, worsening workability and limiting its applications. Improvements are needed.
[0004] While attempts have been made to improve mechanical properties by increasing the density of inorganic fillers such as silicon dioxide and glass fibers, this has resulted in a decrease in the fluidity of the composition due to the high density of inorganic fillers, and has not improved workability (Patent Document 1).
[0005] Furthermore, attempts have been made to improve mechanical properties by adjusting the amount of alkenyl groups contained in the silicone resin composition. However, the limited amount of alkenyl groups restricts the types of organopolysiloxanes that can be used, and this has not led to an improvement in workability (Patent Document 2).
[0006] Furthermore, attempts have been made to improve workability by using specific additives, but these have not been able to improve the mechanical properties of silicone resin, which remains a challenge (Patent Document 3). In addition, improvements in mechanical properties and workability are required for the usage conditions of semiconductor devices in recent years.
[0007] Japanese Patent Publication No. 2014-009322, Japanese Patent Publication No. 2021-102734, Japanese Patent Publication No. 2020-132824
[0008] The present invention has been made in view of the above problems, and aims to provide an addition-curing type silicone composition that gives a cured product with excellent mechanical properties and has low viscosity and excellent workability, and to provide an optoelectronic device equipped with a cured product obtained by curing the composition.
[0009] As a result of diligent research to solve the above problems, the present inventors have found that an addition-curing silicone composition containing an inorganic filler surface-treated with a silicon compound that satisfies predetermined requirements improves the mechanical properties of the cured product and results in a composition with low viscosity and excellent workability. Furthermore, they have found that this addition-curing silicone composition can be suitably used as a encapsulant for optical semiconductor devices such as LEDs, thus completing the present invention.
[0010] In other words, the present invention comprises: (1) (A) an organopolysiloxane having two or more alkenyl groups bonded to silicon atoms in one molecule; 100 parts by mass; (B) an organohydrogenpolysiloxane having two or more hydrosilyl groups in one molecule and not having alkoxy groups bonded to silicon atoms; in an amount such that the molar ratio of hydrosilyl groups to 1 mole of alkenyl groups in component (A) is 0.4 to 4.0; (C) a platinum group metal catalyst; in an amount such that the mass of the platinum group metal is 0.1 to 100 ppm relative to the total mass of components (A) and (B); and (D) an inorganic filler surface-treated with an organosilicon compound, consisting of (D1) and (D2) below; in an amount of 25 parts by mass or more and 900 parts by mass or less relative to 100 parts by mass of component (A); (D1) inorganic filler; The present invention provides an addition-curing silicone composition containing an organosilicon compound having one or more hydrosilyl groups in one molecule and one or more alkoxy groups bonded to silicon atoms in one molecule; this compound is present in an amount of 0.1 to 2 parts by mass per 100 parts by mass of the component (D1).
[0011] Furthermore, the present invention provides an addition-curing silicone composition having at least one of the following configurations: [2] The addition-curing silicone composition according to [1], wherein the (D2) component is one or more selected from silane compounds having one hydrosilyl group and three alkoxy groups having 1 to 10 carbon atoms bonded to a silicon atom, and their partially hydrolyzed condensates. [3] The addition-curing silicone composition according to [1] or [2], wherein the (D1) inorganic filler comprises one or more selected from silicon dioxide, zirconium oxide, titanium oxide, aluminum oxide, and zinc oxide. [4] The addition-curing silicone composition according to any one of [1] to [3], wherein the (D1) inorganic filler has a volume average particle size of 0.1 μm to 150 μm. [5] The addition-curing silicone composition according to any one of [1], [3], and [4], wherein the (D2) component is a linear organopolysiloxane having 2 to 100 silicon-bonded hydrogen atoms in one molecule and having 1 to 3 alkoxy groups having 1 to 10 carbon atoms at at least one of its ends. [6] A base compound which is a mixture of (A) an organopolysiloxane having two or more alkenyl groups bonded to silicon atoms in one molecule; (D1) an inorganic filler; 25 parts by mass to 900 parts by mass per 100 parts by mass of the total of components (A), and (D2) an organosilicon compound having one or more hydrosilyl groups and one or more alkoxy groups bonded to silicon atoms in one molecule; 0.1 to 2 parts by mass per 100 parts by mass of the component (D1), and (B) an organohydrogenpolysiloxane having two or more hydrosilyl groups in one molecule and no alkoxy groups bonded to silicon atoms; in an amount such that the molar ratio of hydrosilyl groups to 1 mole of alkenyl groups in component (A) is 0.4 to 4.0, and (C) Platinum group metal catalyst; an addition-curing silicone composition containing an amount of platinum group metal equivalent to 0.1 to 100 ppm relative to the total mass of component (A) and component (B).
[0012] Furthermore, the present invention provides a cured product of an addition-curing silicone composition according to any one of the above, and an optoelectronic device comprising the cured product.
[0013] The present invention relates to an addition-curing silicone composition containing an inorganic filler, which improves the workability of the composition and provides a cured product with excellent mechanical properties. An optoelectronic device equipped with a cured product obtained by curing the addition-curing silicone composition of the present invention becomes an optoelectronic device with excellent long-term reliability and long-term color rendering, etc., because the semiconductor elements are sealed with a cured product with excellent mechanical properties.
[0014] The present invention will be described in more detail below.
[0015] The addition-curing silicone composition of the present invention contains components (A) to (D) above, but may also contain various known additives as needed. Each component will be described in detail below.
[0016] (A) Organopolysiloxane Component (A) of the present invention is an organopolysiloxane having two or more alkenyl groups bonded to silicon atoms in one molecule. Component (A) may be any organopolysiloxane, such as linear or branched, and two or more may be used in combination. The alkenyl group is preferably one having 2 to 10 carbon atoms, particularly 2 to 8 carbon atoms, and examples include vinyl groups and allyl groups.
[0017] A linear alkenyl group-containing organopolysiloxane can be represented, for example, by the following formula. In the formula, R ４ These are, independently of each other, an alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkyl or cycloalkyl group having 1 to 10 carbon atoms, or an aryl or aralkyl group having 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms. ４ At least two of them are alkenyl groups. Preferably R at both ends ４ It is preferable that each of these is an alkenyl group. In the above formula, n is an integer from 10 to 3,000, preferably an integer from 50 to 2,000, and more preferably an integer from 100 to 500.
[0018] Examples of substituted or unsubstituted alkyl and cycloalkyl groups include lower alkyl groups such as methyl, ethyl, propyl, and butyl groups; and cycloalkyl groups such as cyclohexyl groups, with methyl groups being preferred. Groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine, bromine, or chlorine, or with cyano groups, such as chloromethyl, cyanoethyl, and 3,3,3-trifluoropropyl groups, are also included. Examples of aryl groups include phenyl, tolyl, and xylyl groups. Examples of aralkyl groups include benzyl, phenylethyl, and phenylpropyl groups. Among these, phenyl groups are preferred.
[0019] Examples of alkenyl groups include vinyl, allyl, propenyl, isopropenyl, butenyl, hexenyl, cyclohexenyl, and octenyl groups. Among these, vinyl groups are preferred. It is preferable to have two or more of the aforementioned alkenyl groups in one molecule, and more preferably two to five.
[0020] The linear alkenyl group-containing organopolysiloxane typically has a weight-average molecular weight (Mw) of 1,500 to 300,000, preferably 2,000 to 200,000. If the weight-average molecular weight is below the lower limit, the composition may not harden. Conversely, if the weight-average molecular weight exceeds the upper limit, the composition may become excessively viscous and lose its flowability.
[0021] In this specification, the weight-average molecular weight (Mw) in the present invention refers to the weight-average molecular weight measured using gel permeation chromatography (GPC) with polystyrene as the standard substance, under the following conditions. [Measurement Conditions] • Developing solvent: Tetrahydrofuran (THF) • Flow rate: 0.6 mL / min • Detector: Differential refractive index detector (RI) • Column: TSK Guardcolumn SuperH-L • TSKgel SuperH4000 (6.0 mm I.D. × 15 cm × 1) • TSKgel SuperH3000 (6.0 mm I.D. × 15 cm × 1) • TSKgel SuperH2000 (6.0 mm I.D. × 15 cm × 2) (All manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 20 μL (0.5 wt% THF solution)
[0022] The viscosity of the linear alkenyl group-containing organopolysiloxane is 10 mPa·s to 100,000 mPa·s, preferably 100 mPa·s to 50,000 mPa·s. The viscosity of each component is expressed as the absolute viscosity at 25°C, measured with a rotational viscometer as described in JIS K 7117-1:1999.
[0023] The amount of alkenyl groups contained in the linear organopolysiloxane is preferably 0.0001 to 0.25 mol / 100g, more preferably 0.0025 to 0.10 mol / 100g, and even more preferably 0.005 to 0.05 mol / 100g. If the amount of alkenyl groups bonded to silicon atoms is above the lower limit, there are many crosslinking sites and the composition hardens sufficiently. If the amount of alkenyl groups bonded to silicon atoms is below the upper limit, the cured product has an appropriate crosslinking density and the toughness of the cured product can be ensured.
[0024] Examples of linear alkenyl group-containing organopolysiloxanes include the following compounds. (In the formula, x, y, and z are each integers greater than or equal to 1, and their values satisfy the range of weight-average molecular weight described above.)
[0025] Branched alkenyl group-containing organopolysiloxanes are SiO ４／２ Units and R １SiO ３／２ Either or both of the units, and R １ ３ SiO １／２ units are included. In the above formula, R １ is preferably, independently of each other, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms.
[0026] The branched-chain alkenyl group-containing organopolysiloxane can be represented, for example, by the following average compositional formula. (SiO ４／２ ) ａ (R １ SiO ３／２ ) ｂ (R １ ２ SiO ２／２ ) ｃ (R[[ID=IO]] １ ３ SiO １／２ ) ｄ (1) In the above formula, R １ is independently of each other a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms other than an alkenyl group, or an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms. a, b, c, and d are numbers that satisfy a≧0, b≧0, c≧0, and d>0, respectively, provided that a + b>0 and a + b + c + d = 1. Preferably, 0≦a≦0.8, 0≦b≦0.9, 0.4≦a + b<1, 0≦c<0.6, and 0≦d≦0.6. More preferably, 0 < a≦0.7, 0≦b≦0.8, 0.5≦a + b<1, 0≦c≦0.3, and 0 < d≦0.5.
[0027] A branched-chain organopolysiloxane has at least two silicon atom-bonded alkenyl groups in one molecule. The amount of alkenyl groups contained in the branched-chain organopolysiloxane is preferably 0.01 to 0.5 mol / 100g, more preferably 0.05 to 0.3 mol / 100g, and even more preferably 0.10 to 0.25 mol / 100g. If the amount of alkenyl groups bonded to silicon atoms is above the lower limit, there are many crosslinking sites and the composition hardens sufficiently. If the amount of alkenyl groups bonded to silicon atoms is below the upper limit, the cured product has an appropriate crosslinking density and the toughness of the cured product can be ensured.
[0028] The branched organopolysiloxane may have hydroxyl groups bonded to silicon atoms. The amount of hydroxyl groups bonded to silicon atoms in the branched organopolysiloxane is preferably 0.001 to 1.0 mol / 100g, more preferably 0.005 to 0.8 mol / 100g, and even more preferably 0.008 to 0.6 mol / 100g.
[0029] The branched organopolysiloxane may have alkoxy groups bonded to silicon atoms. These alkoxy groups are preferably carbon-1 to carbon-10, more preferably carbon-1 to carbon-5. The amount of alkoxy groups bonded to silicon atoms in the branched organopolysiloxane is preferably 1.0 mol / 100g or less, more preferably 0.8 mol / 100g or less, and even more preferably 0.5 mol / 100g or less. If the amount of alkoxy groups is below the above upper limit, alcohol gas by-products are not generated during curing, and no voids remain in the cured product. There is no particular lower limit for the amount of alkoxy groups; the less the better.
[0030] Furthermore, the amount of hydroxyl groups and alkoxy groups bonded to silicon atoms in the present invention is １ H-NMR and ２９ This refers to values measured by Si-NMR.
[0031] The branched-chain organopolysiloxane described above preferably has a weight-average molecular weight (Mw) of 1,000 to 50,000, more preferably 1,000 to 20,000, and even more preferably 2,000 to 15,000. If the molecular weight is below the lower limit, the composition may become brittle, and if the molecular weight is above the upper limit, the viscosity of the composition may become high and it may not flow. In this invention, the weight-average molecular weight (Mw) is the weight-average molecular weight with polystyrene as the standard substance, measured by gel permeation chromatography (GPC), and can be measured under the conditions described above.
[0032] The branched organopolysiloxane of the present invention contains 0 to 80 mol%, preferably 0.1 to 70 mol%, of SiO₂ ４／２ Unit (Q units), 0 to 90 mol%, preferably 0 to 80 mol% R １ａ SiO ３／２ The unit (T unit), and 0.1 to 60 mol%, preferably 0.1 to 50 mol%, of (R １ａ ) ３ SiO １／２ It is preferable that it be an organopolysiloxane with a resin structure consisting of units (M units). Also, SiO ４／２ Units and R １ａ SiO ３／２ It is preferable that the sum of the units is 40 mol% or more. In the above formula, R １ａ These are independently a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, an aryl group having 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms. Substituent R １ａ Preferably, at least one of them is an alkenyl group having 2 to 10 carbon atoms.
[0033] R in M units and T units １ａThese are, independently of each other, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms. Examples include lower alkyl groups such as methyl, ethyl, propyl, and butyl groups; cycloalkyl groups such as cyclohexyl groups; aryl groups such as phenyl, tolyl, and xylyl groups; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl groups; and alkenyl groups such as vinyl, allyl, propenyl, isopropenyl, butenyl, hexenyl, cyclohexenyl, and octenyl groups. In addition, some or all of the hydrogen atoms of these groups may be substituted with halogen atoms such as fluorine, bromine, or chlorine, or with cyano groups, such as chloromethyl, cyanoethyl, and 3,3,3-trifluoropropyl groups. Among these, methyl, phenyl, and vinyl groups are preferred.
[0034] SiO ４／２ Examples of materials for obtaining units (Q units) include, but are not limited to, sodium silicate, tetraalkoxysilane, and their condensation reaction products.
[0035] R １ａ SiO ３／２ Examples of materials for obtaining units (T units) include, but are not limited to, organosilicon compounds such as organotrichlorosilanes and organotrialokkoxysilanes represented by the following structural formulas, and their condensation reaction products. (In the above formula, Me represents a methyl group.)
[0036] (R １ａ ) ３ SiO １／２ Examples of materials for obtaining units (M units) include, but are not limited to, organosilicon compounds such as triorganochlorosilanes, triorganoalkoxysilanes, and hexaorganodisiloxanes, represented by the following structural formulas. (In the above formula, Me represents a methyl group.)
[0037] (B) Organohydrogenpolysiloxane Component (B) of the present invention is an organohydrogenpolysiloxane having two or more hydrogen atoms (hereinafter referred to as hydrosilyl groups) bonded to silicon atoms in one molecule, and not having alkoxy groups bonded to silicon atoms. Component (B) reacts with component (A) and acts as a crosslinking agent. Component (B) preferably has at least 2 to 200 hydrosilyl groups in one molecule. More preferably 3 to 100, and even more preferably 4 to 50.
[0038] The viscosity of the organohydrogenpolysiloxane is 0.1 to 5,000 mPa·s, preferably 0.5 to 3,000 mPa·s. The viscosity represents the absolute viscosity at 25°C measured with a rotational viscometer as described in JIS K 7117-1:1999. The amount of hydrogen atoms bonded to silicon atoms in the organohydrogenpolysiloxane is preferably 0.001 to 3.0 mol / 100g, more preferably 0.005 to 2.5 mol / 100g, and even more preferably 0.01 to 2.0 mol / 100g.
[0039] (B) The component can be expressed by the following average unit formula (1). (R ２ ２ R ３ SiO １／２ ) ａ (R ２ R ３ SiO ２／２ ) ｂ (R ３ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (1)
[0040] In the average unit formula (1), R ２ These are, independently of each other, hydrocarbon groups having 1 to 10 carbon atoms, and R ３ These are, independently of each other, hydrocarbon groups having 1 to 10 carbon atoms or hydrogen atoms, and R ３At least two of them are hydrogen atoms, and a, b, c, and d are numbers that satisfy a + b + c + d = 1, where 0.01 ≤ a ≤ 0.8, 0 ≤ b ≤ 0.99, 0 ≤ c ≤ 0.8, and 0 ≤ d ≤ 0.5, respectively.
[0041] The above R ２ and R ３ Examples of hydrocarbon groups having 1 to 10 carbon atoms include saturated aliphatic hydrocarbon groups such as methyl, ethyl, propyl, butyl, and pentyl groups; saturated cyclic hydrocarbon groups such as cyclopentyl and cyclohexyl groups; aryl groups such as phenyl, tolyl, and xyl groups; and aromatic hydrocarbon groups such as benzyl, phenylethyl, and phenylpropyl groups. Among these, saturated aliphatic hydrocarbon groups having 1 to 5 carbon atoms, such as methyl, ethyl, and propyl groups, and phenyl groups are preferred.
[0042] The molecular structure of component (B) is not particularly limited and may be any molecular structure, such as linear, cyclic, branched, or three-dimensional network (resin-like). If component (B) has a linear structure, the hydrosilyl group may be bonded to silicon atoms only at either the molecular chain end or the molecular chain side chain, or to silicon atoms at both. The number of silicon atoms (or degree of polymerization) in one molecule of component (B) is usually 2 to 200, preferably 3 to 100, and an organohydrogenpolysiloxane that is liquid or solid at room temperature (25°C) is preferred.
[0043] Examples of organohydrogenpolysiloxanes represented by the above average unit formula (1) include tris(hydrogendimethylsiloxy)phenylsilane, trimethylsiloxy group-sealed methylhydrogensiloxane / diphenylsiloxane copolymer, trimethylsiloxy group-sealed methylhydrogensiloxane / diphenylsiloxane / dimethylsiloxane copolymer, trimethylsiloxy group-sealed methylhydrogensiloxane / methylphenylsiloxane / dimethylsiloxane copolymer, dimethylhydrogensiloxy group-sealed methylhydrogensiloxane / dimethylsiloxane / diphenylsiloxane copolymer, dimethylhydrogensiloxy group-sealed methylhydrogensiloxane / dimethylsiloxane / methylphenylsiloxane copolymer, (CH ３ ) ２ HSiO １／２ Units and SiO ４／２ Units and (C ６ H ５ ) ３ SiO １／２ Examples include copolymers composed of units.
[0044] (B) More specifically, the organohydrogenpolysiloxane shown in the following structure may also be included as a component, but is not limited to the following. (In the formula, p and r are integers between 0 and 198, q is an integer between 1 and 200, and p + q + r is less than or equal to 198.)
[0045] In the silicone resin composition of the present invention, the amount of component (B) is such that the ratio of the number of hydrosilyl groups in component (B) to the number of alkenyl groups bonded to silicon atoms in component (A) is 0.4 to 4.0, more preferably 0.5 to 3.5, and even more preferably 0.8 to 3.0. When the amount of the hydrosilyl group of component (B) is less than the above lower limit, the curing reaction of the composition of the present invention does not proceed sufficiently, and the crosslinking density and mechanical strength of the obtained cured product become insufficient, and there is a risk of inferior heat resistance. Further, when the amount of the hydrosilyl group of component (B) exceeds the above upper limit, there is a risk that a large amount of unreacted hydrosilyl groups will remain in the cured product, and there is a risk of physical property changes over time and a decrease in the heat resistance of the cured product. Furthermore, there is also a risk of foaming due to dehydrogenation reaction in the cured product. Note that the amount of the hydrosilyl group of component (D) described later shall not be included in the calculation of the blending amount of component (B) above.
[0046] (C) Platinum group metal-based catalyst Component (C) is a platinum group metal-based catalyst, and any conventionally known catalyst can be used as a catalyst for promoting the hydrosilylation reaction of components (A) and (B). Considering costs and the like, platinum-based ones such as platinum, platinum black, chloroplatinic acid, for example, H ２ PtCl ６ ·pH ２ O, K ２ PtCl ６ , KHPtCl ６ ·pH ２ O, K ２ PtCl ４ , K ２ PtCl ４ ·pH ２ O, PtO ２ ·pH ２ O, PtCl ４ ·pH ２ O, PtCl ２ , H ２ PtCl ４ ·pH ２O (where p is a positive integer), etc., and complexes of these with hydrocarbons such as olefins, alcohols or vinyl group-containing organopolysiloxanes, complexes having photoactivity such as trimethyl(methylcyclopentadienyl)platinum, etc. can be exemplified. These catalysts can be used alone or in combination of two or more. (C) The blending amount of the catalyst is a catalytic amount and is not particularly limited. The blending amount of the catalyst may be an effective amount for promoting curing. Usually, 0.05 to 100 ppm in terms of mass conversion as a platinum group metal is preferable with respect to the total amount of components (A) and (B).
[0047] (D) Surface-treated inorganic filler The component (D) of the present invention is an inorganic filler surface-treated with an organosilicon compound, and is formed from the following (D1) inorganic filler and (D2) organosilicon compound. The amount of the inorganic filler surface-treated with the organosilicon compound in the silicone resin composition is 25 parts by mass or more and 900 parts by mass or less, preferably 50 to 700 parts by mass, more preferably 100 to 400 parts by mass with respect to 100 parts by mass of the component (A). The addition-curing type silicone composition containing the inorganic filler surface-treated with the organosilicon compound can give a cured product with further improved mechanical properties and can further improve the workability of the addition-curing type silicone composition.
[0048] (D1) Inorganic filler In the addition reaction type silicone composition of the present invention, the inorganic filler preferably has a volume average particle diameter of 0.1 μm to 150 μm, more preferably 0.1 μm to 100 μm, still more preferably 0.1 μm to 50 μm. The volume average particle diameter is a value measured by the laser diffraction / scattering method. There is an advantage that sedimentation of the inorganic filler over time can be suppressed.
[0049] As the inorganic filler, for example, silicon dioxide (silica: SiO ２ ), zirconium oxide (zirconia: ZrO ２ ), titanium oxide (titania: TiO ２ ), aluminum oxide (alumina: Al ２ O ３ ), zinc oxide (ZnO), iron oxide (FeO ２ ), magnetite (Fe ３O ４ ), lead oxide (PbO ２ ), tin oxide (SnO ２ ), cerium oxide (CeO ２ ), calcium oxide (CaO), trimanganese tetroxide (Mn ３ O ４ Examples include magnesium oxide (MgO), aluminum nitride (AlN), and boron nitride (BN). These inorganic fillers can be used individually or in combination of two or more. Among them, silicon dioxide, zirconium oxide, titanium oxide, aluminum oxide, and zinc oxide are preferred. By using these inorganic fillers, the properties of the cured product when added to a silicone resin composition can be made particularly excellent.
[0050] The amount of inorganic filler (D1) in the silicone resin composition is 25 parts by mass or more and 900 parts by mass or less per 100 parts by mass of the total of components (A) to (C), preferably 50 parts by mass or more and 650 parts by mass or less, and more preferably 100 parts by mass or more and 400 parts by mass or less. Component (D1) can be blended alone or in combination of two or more types. If the amount of component (D1) is below the lower limit, the effect of the inorganic filler cannot be fully obtained. Conversely, if it exceeds the upper limit, the effect of the silicone cannot be fully obtained, and the durability of the optoelectronic device using the cured product cannot be improved, which is undesirable.
[0051] (D2) Surface treatment agent Component (D2) is a surface treatment agent for the inorganic filler (D1) described above, and is a component for imparting fluidity to the addition-curing silicone composition of the present invention. Component (D2) is an organosilicon compound having one or more hydrosilyl groups and one or more alkoxy groups bonded to silicon atoms in one molecule. Preferably, it is an organosilicon compound having one hydrosilyl group and three alkoxy groups bonded to silicon atoms. The organosilicon compound is preferably one or more selected from alkoxysilane compounds and partially hydrolyzed condensates of the alkoxysilane. Alternatively, the organosilicon compound may be a linear organopolysiloxane. Preferably, the linear organopolysiloxane has 2 to 100 silicon-bonded hydrogen atoms in one molecule, and at least one of its ends has 1 to 3 alkoxy groups having 1 to 10 carbon atoms. In this invention, the number of alkoxy groups bonded to a silicon atom is counted as one alkoxysilyl group, two dialkoxysilyl groups, three trialkoxysilyl groups, and so on, even if there are multiple alkoxy groups on the same silicon atom, and not the number of silicon atoms having alkoxy groups.
[0052] The (D2) component is preferably an alkoxysilane represented by the following formula (1), or a partially hydrolyzed condensate of the alkoxysilane. In the above formula (1), R ５ R is an alkoxy group having 1 to 10 carbon atoms, preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group or an ethoxy group. ７ is an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms. a is an integer from 1 to 3, preferably 2 or 3, and more preferably 3.
[0053] Component (D2) includes the partial hydrolysis product of the above alkoxysilane compound. A partial hydrolysis condensate is an oligomer formed when some of the alkoxy groups of the alkoxysilane compound are hydrolyzed and condensed with other alkoxysilanes. Preferably, the oligomer is a hydrolysis condensate with a degree of polymerization of 5 or less.
[0054] Examples of alkoxysilane compounds include, but are not limited to, those listed below.
[0055] Furthermore, another preferred embodiment of component (D2) may be a linear organopolysiloxane represented by the following formula (2). In the above equation (2), R ５ and R ８ R is an alkoxy group having 1 to 10 carbon atoms, preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group or an ethoxy group. ７ R is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ６ R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms. However, R ６ and R ７ At least one of these atoms is a hydrogen atom. Preferably, each molecule has 2 to 100 silicon-bonded hydrogen atoms, more preferably 3 to 50.
[0056] In formula (2) above, k is an integer of 1 or more, 1 ≤ k ≤ 200, more preferably 3 ≤ k ≤ 100, and even more preferably 5 ≤ k ≤ 50. a is an integer from 1 to 3, preferably 2 or 3, and more preferably 3. b is an integer from 0 to 3. If formula (2) above is an organopolysiloxane having alkoxy groups at both ends, b is preferably 2 or 3, and more preferably 3. If it is an organopolysiloxane having an alkoxy group at only one end, b is 0.
[0057] Examples of linear organopolysiloxanes include, but are not limited to, the compounds listed below. In the formula, m and n are integers greater than or equal to 1, and m + n ≥ 2. Preferably, 2 ≤ m + n ≤ 100, more preferably 3 ≤ m + n ≤ 50, and even more preferably 5 ≤ m + n ≤ 50.
[0058] The amount of component (D2) is 0.1 to 2 parts by mass per 100 parts by mass of inorganic filler (D1), preferably 0.3 to 1.5 parts by mass, and more preferably 0.5 to 1.0 parts by mass. If the amount of component (D2) relative to component (D1) is too small, the fluidity of the inorganic filler may decrease, and if the amount of component (D2) is too large, the mechanical properties of the resulting cured product may decrease, or the composition may undergo dehydrogenation.
[0059] Component (D) of the present invention is obtained by surface-treating the inorganic filler (D1) with the organic compound (D2). A known method can be used for surface-treating the inorganic filler. For example, there are dry methods and wet methods for surface-treating the inorganic filler, but the wet method is preferred from the viewpoint of uniform treatment of the inorganic filler and prevention of gel. Alternatively, a method may be used in which the inorganic filler has been surface-treated by mixing components (D1) and (D2) in advance, or the organic compound (D2) may be added when kneading the alkenyl group-containing organosiloxane (A) and the inorganic filler (D1) to surface-treat the inorganic filler while kneading. In other words, the addition-curing silicone composition of the present invention may be produced by surface-treating the inorganic filler with component (D2) by kneading components (A), (D1), and (D2), and using the resulting mixture as a base compound, and then mixing components (B) and (C) into the base compound.
[0060] In a method for surface-treating inorganic fillers during base compound preparation, the mixing temperature and time can be adjusted as appropriate according to conventionally known methods. For example, mixing at 50°C to 150°C for 1 to 24 hours is preferable. Mixing at a temperature of 50°C or higher allows for a sufficiently fast surface treatment. Mixing at a temperature of 150°C or lower makes it easier to control the reaction and prevents gelation and discoloration. Furthermore, a mixing time of 1 hour or more allows for sufficient treatment, while a mixing time of 24 hours or less allows for good production efficiency.
[0061] Accordingly, another preferred embodiment of the present invention is the following addition-curing silicone composition: (A) an organopolysiloxane having two or more alkenyl groups bonded to silicon atoms in one molecule; (D1) an inorganic filler; 25 parts by mass to 900 parts by mass per 100 parts by mass of the total of components (A); and (D2) an organosilicon compound having one or more hydrosilyl groups and one or more alkoxy groups bonded to silicon atoms in one molecule; 0.1 to 2 parts by mass per 100 parts by mass of components (D1), which is a base compound, and (B) an organohydrogenpolysiloxane having two or more hydrosilyl groups in one molecule and no alkoxy groups bonded to silicon atoms; in an amount such that the molar ratio of hydrosilyl groups to 1 mole of alkenyl groups in component (A) is 0.4 to 4.0, and (C) Platinum group metal catalyst; an addition-curing silicone composition containing an amount of platinum group metal equivalent to 0.1 to 100 ppm relative to the total mass of components (A) and (B). Details of each component are as described above.
[0062] In addition to the above components (A) to (D), the addition-curing silicone composition of the present invention may contain known adhesion promoters and additives as needed.
[0063] [Adhesion-Enhancing Agents] Examples of adhesion-enhancing agents include phenyltrimethoxysilane, methyltrimethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and oligomers thereof. These adhesion-enhancing agents can be used individually or in combination of two or more. The amount of adhesion-enhancing agent is preferably 0 to 10% by mass, and more preferably 0 to 5% by mass, relative to the total mass of components (A) to (D) above.
[0064] [Other Additives] Other additives include, for example, reinforcing inorganic fillers such as glass fiber, fumed silica, and fumed titanium oxide; inorganic white pigments such as calcium carbonate, aluminum hydroxide, barium carbonate, magnesium silicate, zinc sulfate, and barium sulfate; non-reinforcing inorganic fillers such as calcium silicate, carbon black, cerium fatty acid salts, barium fatty acid salts, cerium alkoxide, and barium alkoxide; and fillers such as silver (A), aluminum (Al), and barium oxide (BaO). These can be appropriately blended in an amount of 800 parts by mass or less, preferably 10 to 600 parts by mass, per 100 parts by mass of the total of components (A) to (D) above.
[0065] The addition-curing silicone composition of the present invention can be cured after being applied to a predetermined substrate depending on the application. While sufficient curing occurs at room temperature (25°C), curing may be performed by heating if necessary. For example, curing can be performed at temperatures between 60 and 200°C.
[0066] The addition-curing silicone composition of the present invention can be used in a variety of applications, such as encapsulants, adhesives, electrical insulating materials, laminates, coatings, inks, paints, sealants, resists, composite materials, films, underfill materials, anti-reflective materials, light-diffusing materials, and light-reflective materials, but is not limited to these.
[0067] Furthermore, the present invention provides an optoelectronic device in which a semiconductor element is encapsulated with a cured product of the addition-curing silicone composition of the present invention described above.
[0068] Such an addition-curing silicone composition of the present invention will yield a cured product with excellent mechanical properties.
[0069] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. Parts represent parts by mass, and the viscosity of each component is the absolute viscosity at 25°C measured with a rotational viscometer as described in JIS K 7117-1:1999. The meanings of the abbreviations for each siloxane unit are as follows: M Ｈ : (CH ３ )２ HSiO １／２ M: (CH ３ ) ３ SiO １／２ M Ｖｉ : (CH ２ =CH)(CH ３ ) ２ SiO １／２ D Ｈ : (CH ３ ) HSiO ２／２ D: (CH ３ ) ２ SiO ２／２ Q: SiO ４／２
[0070] [(A) Organopolysiloxane] (A-1) Average molecular formula: M Ｖｉ ２ D ２００ (Vinyl group content: 0.013 mol / 100g), organopolysiloxane (A-2) having a viscosity of 1.0 Pa·s and a weight-average molecular weight of 14,000, siloxane units are M Ｖｉ An organopolysiloxane that is solid at 23°C, containing 10 mol% units, 40 mol% M units, and 50 mol% Q units, with a weight-average molecular weight of 5,300 and a vinyl group content of 0.1 mol / 100g.
[0071] [(B) Organohydrogenpolysiloxane] (B-1) Average molecular formula: M ２ D Ｈ ３８ An organohydrogenpolysiloxane with a viscosity of 20 mPa·s, represented by (hydrosilyl group content: 1.55 mol / 100 g).
[0072] [(C) Curing catalyst] (C-1) Octyl alcohol-modified solution of a platinum complex having 1,3-divinyltetramethyldisiloxane derived from chloroplatinic acid as a ligand (platinum element content: 1% by mass)
[0073] [(D1) Inorganic Fillers] (D1-1) CR-50 [Titanium oxide powder, volume average particle size: 0.2 μm], manufactured by Ishihara Sangyo Co., Ltd. (D1-2) Zinc Oxide Type 1 [Zinc oxide powder, volume average particle size: 0.4 μm], manufactured by Mitsui Mining & Smelting Co., Ltd. (D1-3) TZ-3YS-E [Zirconium oxide, volume average particle size: 0.6 μm], manufactured by Tosoh Co., Ltd. (D1-4) ACT-05 [Silicon dioxide, volume average particle size: 5.0 μm], manufactured by Fumitec Co., Ltd. (D1-5) AO-502 [Aluminum oxide, volume average particle size: 0.2 μm], manufactured by Admatex Co., Ltd.
[0074] [(D2) Surface treatment agent] (D2-1) Triethoxysilane (D2-2) Partial hydrolysate of triethoxysilane (average trimer) Comparative component: (D2-3) KBM-13 (methyltrimethoxysilane: manufactured by Shin-Etsu Chemical Co., Ltd.) (D2-4) Ethyl silicate 40 (partial hydrolysate of tetraethoxysilane, average pentamer: manufactured by Colcoat)
[0075] [Example 1] Using a 1-liter planetary mixer (manufactured by Inoue Seisakusho Co., Ltd.), 100 parts of a 1:1 mixture of the pre-prepared components (A-1) and (A-2) and 100 parts of the inorganic filler (D1-1) were added and mixed at 120°C under reduced pressure of 5 kPa for 1 hour. Then, 1.0 part of the organosilicon compound (D2-1) was added and mixed at 120°C under normal pressure for 1 hour and under reduced pressure of 5 kPa for 1 hour to prepare a base compound. In this process, the inorganic filler was surface-treated with the organosilicon compound. Subsequently, an amount of component (B-1) equal to 1.2 (in this case, 4.0 parts by mass) was added to the mixture at 25°C for 30 minutes, and finally 0.1 parts of component (C-1) (equivalent to 10 ppm of platinum) was added and mixed at 25°C for 30 minutes to prepare an addition-curing silicone composition. The obtained addition-curing silicone composition was heated and molded at 150°C for 4 hours to form a cured product (120 mm × 110 mm × 1 mm), and the following physical properties were measured. The results are shown in Table 1.
[0076] [Examples 2-12, Comparative Examples 1-14] Addition-curing silicone compositions were prepared by repeating the steps of Example 1, except that components (A) to (C), (D1) and (D2) were used with the compositions described in Tables 1 and 3. The addition-curing silicone compositions were cured in the same manner as in Example 1 to form cured products, and their physical properties were measured. The results of measuring the physical properties of the compositions and cured products are shown in Tables 2 and 4.
[0077] (1) Appearance: The color, transparency, and presence or absence of voids of the cured product (1 mm) obtained by curing each addition-curing silicone composition at 150°C for 4 hours were visually inspected.
[0078] (2) The fluidity of each addition-curing silicone composition before curing was confirmed. 50 g of the addition-curing silicone composition was added to a 100 ml glass bottle, and the glass bottle was left on its side at 25°C for 10 minutes. If the resin flowed out during this time, it was determined to be in liquid form.
[0079] (3) Viscosity The viscosity of each addition-curing silicone composition before curing at 25°C was measured by the method described in JIS K 7117-1:1999.
[0080] (4) Thixotropic ratio The viscosity at 10 rpm and the viscosity at 1 rpm of each addition-curing silicone composition before curing at 25°C were measured by the method described in JIS K 7117-1:1999, and the thixotropic ratio was calculated as viscosity at 1 rpm / viscosity at 10 rpm.
[0081] (5) Hardness (Type A) The hardness of the cured product obtained by curing each addition-curing silicone composition at 150°C for 4 hours was measured using a durometer type A hardness tester in accordance with JIS K 6249:2003.
[0082] (6) Elongation at break and tensile strength Each addition-curing silicone composition was cured at 150°C for 4 hours, and the elongation at break and tensile strength of the cured product were measured in accordance with JIS K 6249:2003.
[0083] (7) Flowability of the composition 1.0 g of each addition-curing silicone composition was weighed onto a horizontally placed glass plate, left to stand for 30 minutes at 25°C, and then cured at 150°C for 1 hour. The length was then measured. Here, length refers to the maximum straight-line distance from end to end of the addition-curing silicone composition. If it flows to a length of 30 mm or more, it indicates that the addition-curing silicone composition has good fluidity. (Fluidity judgment criteria) A (Good): Shows sufficient fluidity B (Poor): Insufficient fluidity
[0084] (8) Flatness of the composition 1.0 g of each addition-curing silicone composition was weighed onto a horizontally placed glass plate, left to stand for 30 minutes at 25°C, and then cured at 150°C for 1 hour. The thickness of the resin was measured. The thickness of the resin was measured at three points, and if the difference between the maximum and minimum thickness was less than 50 μm, it was considered that the addition-curing silicone composition was sufficiently flat. (Flatness judgment criteria) A (Good): Sufficiently flat B (Poor): Not flat
[0085]
[0086]
[0087]
[0088]
[0089] As shown in Tables 1 and 2, the silicone compositions of Examples 1 to 12, which include an inorganic filler surface-treated with a silicon compound satisfying the conditions of the present invention as component (D), have sufficient viscosity, thixotropy, and resin flowability, and yield cured products with excellent appearance, tensile strength, elongation at break, and resin flatness. In contrast, as shown in Tables 3 and 4, the silicone compositions of Comparative Examples 1 to 12, which include an inorganic filler surface-treated with a silicon compound that does not satisfy the conditions of the present invention, have high viscosity and thixotropy, and the resulting cured products have reduced tensile strength and elongation at break. Furthermore, the resin flowability and resin flatness are also insufficient. The silicone composition of Comparative Example 13, which includes an inorganic filler that has not been treated with any silicon compound, showed a further decrease in viscosity, thixotropy, tensile strength, and elongation at break. In addition, the silicone composition of Comparative Example 14, in which the amount of inorganic filler was reduced, had no problems with viscosity, thixotropy, resin flowability, or resin flatness, but the resulting cured product showed a decrease in mechanical strength, such as tensile strength and elongation at break.
[0090] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention.
Claims
1. (A) Organopolysiloxane having two or more alkenyl groups bonded to silicon atoms in one molecule; 100 parts by mass (B) Organohydrogenpolysiloxane having two or more hydrosilyl groups in one molecule and no alkoxy groups bonded to silicon atoms; an amount such that the molar ratio of hydrosilyl groups to 1 mole of alkenyl groups in component (A) is 0.4 to 4.0 (C) Platinum group metal catalyst; an amount such that the mass of the platinum group metal is 0.1 to 100 ppm relative to the total mass of components (A) and (B), and (D) an inorganic filler surface-treated with an organosilicon compound, consisting of (D1) and (D2) below; 25 parts by mass or more and 900 parts by mass or less per 100 parts by mass of component (A) (D1) Inorganic filler; (D2) An organosilicon compound having one or more hydrosilyl groups in one molecule and one or more alkoxy groups bonded to a silicon atom in one molecule; an addition-curing silicone composition containing 0.1 to 2 parts by mass of this compound per 100 parts by mass of component (D1).
2. The addition-curing silicone composition according to claim 1, wherein the (D2) component is one or more selected from silane compounds having one hydrosilyl group and three alkoxy groups having 1 to 10 carbon atoms bonded to a silicon atom, and partially hydrolyzed condensates thereof.
3. The addition-curing silicone composition according to claim 1, wherein the (D1) inorganic filler comprises one or more selected from silicon dioxide, zirconium oxide, titanium oxide, aluminum oxide, and zinc oxide.
4. The addition-curing silicone composition according to claim 1, wherein the (D1) inorganic filler has a volume-average particle size of 0.1 μm to 150 μm.
5. A base compound comprising: (A) an organopolysiloxane having two or more alkenyl groups bonded to silicon atoms in one molecule; (D1) an inorganic filler; 25 parts by mass to 900 parts by mass per 100 parts by mass of component (A); and (D2) an organosilicon compound having one or more hydrosilyl groups and one or more alkoxy groups bonded to silicon atoms in one molecule; 0.1 to 2 parts by mass per 100 parts by mass of component (D1); and (B) an organohydrogenpolysiloxane having two or more hydrosilyl groups in one molecule and no alkoxy groups bonded to silicon atoms; in an amount such that the molar ratio of hydrosilyl groups to 1 mole of alkenyl groups in component (A) is 0.4 to 4.0, and (C) Platinum group metal catalyst; an addition-curing silicone composition containing an amount of platinum group metal equivalent to 0.1 to 100 ppm relative to the total mass of component (A) and component (B).
6. An optoelectronic device comprising a cured product of an addition-curing silicone composition according to any one of claims 1 to 5.