CURABLE SILICONE COMPOSITION, ENCAPSULATING MATERIAL, AND OPTICAL SEMICONDUCTOR DEVICE

Abstract

To provide a curable silicone composition capable of forming a transparent high-hardness cured product which exhibits practically effective curability even at low temperatures, has a low shape deformation and shrinkage rate during curing, and can be cured in a short period of time.SOLUTION: There is provided a curable silicone composition which comprises (A) a resinous alkenyl group-containing organopolysiloxane containing at least two alkenyl groups per molecule and at least one (SiO4 / 2) unit, (B) a resinous organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to a silicon atom per molecule and at least one (SiO4 / 2) unit, (C) a catalyst for hydrosilylation reaction, and (D) a curing reaction inhibitor.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a curable silicone composition, more specifically, to a curable silicone composition suitable for use as an encapsulant for optical semiconductor devices. The present invention also relates to an optical semiconductor device encapsulated with an encapsulant made of a cured product of the curable silicone composition. [Background technology]

[0002] Curable silicone compositions are used in a wide range of industrial fields because they cure to form cured products that have excellent heat resistance, cold resistance, electrical insulation, weather resistance, water resistance, and transparency. In particular, the cured products are less susceptible to discoloration than other organic materials, and the deterioration of physical properties is small, making them suitable for use as optical materials.

[0003] In recent years, silicone encapsulants used in optical semiconductor devices such as light-emitting diodes (LEDs) are required to have high transparency in order to achieve higher light extraction efficiency, and high dimensional stability in order to achieve high production efficiency in the mounting process.

[0004] For example, Patent Document 1 describes a hydrosilylation reaction curable organopolysiloxane composition comprising (A) a methylphenylalkenylpolysiloxane in which diphenylsiloxane units account for 5 mol % or less of the total siloxane units, at least 20 mol % of all silicon-bonded organic groups in the molecule are phenyl groups, and at least two silicon-bonded alkenyl groups per molecule, (B) a methylphenylhydrogenpolysiloxane in which diphenylsiloxane units account for 5 mol % or less of the total siloxane units, at least 20 mol % of all silicon-bonded organic groups in the molecule are phenyl groups, and at least two silicon-bonded hydrogen atoms per molecule, and (C) a hydrosilylation reaction catalyst, wherein the diphenylsiloxane units in the composition account for 5 mol % or less of the total siloxane units.

[0005] In addition, Patent Document 2 discloses a compound having the general formula (A): R 13SiO(R 1 2SiO) m SiR 1 3 (in the formula, each R 1 are independently unsubstituted or halogen-substituted monovalent hydrocarbon groups, provided that at least two R 1 is an alkenyl group, and all R 1 at least 30 mol % of the aryl group is an aryl group, and m is an integer of 5 to 1,000; and 1 SiO 3 / 2 ) g (R 1 2SiO 2 / 2 ) h (R 1 3SiO 1 / 2 ) i (SiO 4 / 2 ) j (XO 1 / 2 ) k {where, R 1 is the same as above, except that at least two R 1 is an alkenyl group, and all R 1 wherein at least 30 mol % of all silicon-bonded organic groups are aryl groups, g is a positive number, h is 0 or a positive number, i is 0 or a positive number, j is 0 or a positive number, k is 0 or a positive number, and h / g is a number from 0 to 10, i / g is a number from 0 to 5, j / (g+h+i+j) is a number from 0 to 0.3, and k / (g+h+i+j) is a number from 0 to 0.4; (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule, and at least 15 mol % of all silicon-bonded organic groups are aryl groups; (C) an organopolysiloxane having an average unit formula: (R 2 SiO 3 / 2 ) b (R 2 2SiO 2 / 2 ) c (R 2 3SiO 1 / 2 ) d (SiO 4 / 2 ) e (XO 1 / 2 ) f {In the formula, each R 2are independently an alkyl group, an alkenyl group, an aryl group, or an epoxy-containing organic group, provided that in one molecule, 2 at least 5 mol % of the above are alkenyl groups, at least 15 mol % are aryl groups, and at least 10 mol % are epoxy-containing organic groups, X is a hydrogen atom or an alkyl group, b is a positive number, c is 0 or a positive number, d is 0 or a positive number, e is 0 or a positive number, f is 0 or a positive number, and c / b is a number from 0 to 10, d / b is a number from 0 to 5, e / (b+c+d+e) is a number from 0 to 0.3, and f / (b+c+d+e) is a number from 0 to 0.02.

[0006] Patent Document 3 describes a curable organopolysiloxane composition comprising at least: (A) a diorganopolysiloxane having at least two alkenyl groups in one molecule and in which 70 mol % or more of all siloxane units are methylphenylsiloxane units (with the proviso that the total content of 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane and 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclotetrasiloxane is 5 wt % or less); (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule and in which 15 mol % or more of the silicon-bonded organic groups are phenyl groups {an amount such that the number of moles of silicon-bonded hydrogen atoms in component (B) is 10 to 500% of the total number of moles of alkenyl groups in component (A)}; and (C) a hydrosilylation reaction catalyst (in an amount sufficient to cure the composition).

[0007] Patent Document 4 also describes (A) a branched-chain organopolysiloxane having at least three alkenyl groups in one molecule and at least 30 mol % of all silicon-bonded organic groups being aryl groups, (B) a linear organopolysiloxane having both molecular chain terminals blocked with diorganohydrogensiloxy groups and containing aryl groups {in an amount such that the number of silicon-bonded hydrogen atoms in this component is 0.5 to 2 moles per mole of alkenyl groups in component (A)}, (C) a linear organopolysiloxane having at least three diorganohydrogensiloxy groups in one molecule and at least 30 mol % of all silicon-bonded organic groups being aryl groups, The document describes a curable organopolysiloxane composition comprising at least a branched-chain organopolysiloxane having diorganohydrogensiloxy groups in which at least 15 mol % of all silicon-bonded organic groups are aryl groups {an amount such that the diorganohydrogensiloxy groups in component (B) and this component account for 1 to 20 mol % of the total amount of diorganohydrogensiloxy groups}, and (D) a hydrosilylation reaction catalyst (in an amount sufficient to promote curing of the composition).

[0008] In addition, Patent Document 5 describes A) an average unit formula: (R 1 3SiO 1 / 2 ) a (R 1 2SiO 2 / 2 ) b (R 2 SiO 3 / 2 ) c (R 3 SiO 3 / 2 ) d (In the formula, R 1 are the same or different, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, provided that at least two R 1 is the alkenyl group, R 2 is an aryl group having 6 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, R 3is an alkyl group having 1 to 12 carbon atoms, and a, b, c, and d are numbers that satisfy 0.01≦a≦0.5, 0≦b≦0.7, 0.01≦c<0.7, 0.1≦d<0.9, and a+b+c+d=1, respectively; (B) a linear organopolysiloxane having at least two silicon-bonded alkenyl groups and at least one silicon-bonded aryl group per molecule {0.1 to 150 parts by mass per 100 parts by mass of component (A)}; (C) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule {an amount such that the number of silicon-bonded hydrogen atoms in component (A) and component (B) is 0.1 to 5 moles per mole of alkenyl groups combined}; and (D) a hydrosilylation catalyst (an amount that promotes curing of the composition).

[0009] In addition, Patent Document 6 describes a compound having at least two alkenyl groups in one molecule and represented by the formula: R 1 2SiO 2 / 2 (In the formula, R 1 is an aryl group. 4 / 2 Siloxane units represented by the formula: R 2 2R 3 SiO 1 / 2 (In the formula, R 2 is a monovalent hydrocarbon group that does not have an aliphatic unsaturated bond, and R 3 is an alkenyl group.) and a siloxane unit represented by the formula: R 2 3SiO 1 / 2 (In the formula, R 2are the same as above.) and have different mass average molecular weights, as calculated using standard polystyrene standards, as determined by gel permeation chromatography {10 to 100 parts by mass per 100 parts by mass of component (A)}, (C) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule {the amount of silicon-bonded hydrogen atoms in this component is 0.1 to 10 moles per mole of alkenyl groups in components (A) and (B)}, and (D) a catalytic amount of a hydrosilylation reaction catalyst.

[0010] However, since the conventional encapsulants using thermosetting silicone compositions require long-term treatment at high temperatures to cure, the shape of the encapsulants shrinks during curing, which can result in warping of the flexible substrate, reduced patterning accuracy in the mounting process of semiconductor elements, or damage to electronic elements mounted on the substrate due to heat. Furthermore, conventional silicones that can be cured at room temperature or low temperature have problems such as poor transparency and adhesion of the cured product formed, and are not suitable for encapsulants in terms of long-term reliability, such as delamination. In addition, when a conventional curable silicone composition containing an organopolysiloxane having an aryl group in its molecular chain is used as an encapsulant, there is a problem that the viscosity of the encapsulant is significantly reduced at high temperatures, and the encapsulant easily changes shape when cured, because the organopolysiloxane having an aryl group is easily affected by temperature. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Special Publication No. 2012-507582 [Patent Document 2] JP 2015-78375 A [Patent Document 3] JP 2010-84118 A [Patent Document 4] JP 2010-1336 A [Patent Document 5] Special Publication No. 2016-534162 [Patent Document 6] Special Publication No. 2016-529331 Summary of the Invention [Problem to be solved by the invention]

[0012] An object of the present invention is to provide a silicone composition which exhibits practically effective curability even at low temperatures, undergoes little change in shape or shrinkage upon curing, can be cured in a short period of time, and is capable of forming a transparent cured product with high hardness.

[0013] Another object of the present invention is to provide an encapsulant containing the curable silicone composition of the present invention. Still another object of the present invention is to provide an optical semiconductor device encapsulated with the encapsulant of the present invention. [Means for solving the problem]

[0014] In order to solve the above problems, the present inventors have conducted extensive research and have surprisingly found that (A) one molecule of a cyclic alkylene glycol having at least two alkenyl groups and at least one (SiO 4 / 2 (B) a resin-like alkenyl-containing organopolysiloxane containing at least two silicon-bonded hydrogen atoms and at least one (SiO 4 / 2 The present inventors have discovered that a curable silicone composition comprising a resinous organohydrogenpolysiloxane containing (C) a hydrosilylation reaction catalyst, and (D) a curing reaction inhibitor can be cured efficiently even at low temperatures, has a low shrinkage during curing, can be cured in a short time, and can form a cured product that is highly transparent and has a high hardness, thereby completing the present invention.

[0015] In one embodiment of the present invention, the (C) hydrosilylation reaction catalyst is a platinum-based catalyst, and is contained in an amount such that the amount of platinum atoms is 10 ppm or less, relative to the total mass of the curable silicone composition.

[0016] In one embodiment of the present invention, the content of the curing reaction inhibitor (D) is 200 ppm or more, based on the total mass of the curable silicone composition.

[0017] In one embodiment of the present invention, the curable silicone composition comprises a linear alkenyl group-containing organopolysiloxane and / or RSiO 4 / 2 The organopolysiloxane may further comprise a resin-like alkenyl group-containing organopolysiloxane that does not contain a siloxane unit represented by the formula:

[0018] In one embodiment of the present invention, the curable silicone composition may further comprise a linear organohydrogenpolysiloxane.

[0019] The present invention also relates to an encapsulant comprising the curable silicone composition according to the present invention.

[0020] The present invention also relates to an optical semiconductor device comprising the encapsulant according to the present invention. Effect of the Invention

[0021] The curable silicone composition according to the present invention exhibits practically effective curability even at low temperatures, undergoes little change in shape or shrinkage during curing, can be cured in a short period of time, and can provide a cured product that is transparent and has a high degree of hardness.

[0022] In addition, the encapsulant of the present invention is formed from the curable silicone composition of the present invention, and therefore can encapsulate semiconductor elements at low temperatures in a short time. This prevents deformation of the encapsulated shape due to a decrease in viscosity during curing caused by heating at high temperatures for a long time, and prevents damage to the semiconductor elements due to heat. Furthermore, the encapsulant of the present invention can encapsulate semiconductor elements with a transparent, hard cured product. This allows the manufacture of semiconductor packages with excellent reliability and transparency. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will be described in detail below.

[0024] [Curable Silicone Composition] The present invention relates to a curable silicone composition that can be practically cured at low temperatures, (A) at least two alkenyl groups and at least one (SiO 4 / 2 ) units, (B) at least two silicon-bonded hydrogen atoms and at least one (SiO 4 / 2 ) units, (C) a hydrosilylation catalyst, and (D) Curing reaction inhibitor Includes.

[0025] The curable silicone composition of the present invention can be effectively cured even at low temperatures. The curing temperature is not particularly limited, but is, for example, 120°C or less, preferably 100°C or less. The curing temperature can usually be room temperature or higher. The curing time is not particularly limited, but is a time that is practically problem-free, for example, within 60 minutes, preferably within 50 minutes, when curing at 60°C, and for example, within 45 minutes, more preferably within 30 minutes, when curing at 100°C.

[0026] The viscosity of the curable silicone composition according to the present invention is not particularly limited, but is, for example, 1000 mPa·s or more at 25° C., more preferably 2000 mPa·s or more, even more preferably 3000 mPa·s or more, preferentially 3500 mPa·s or more, and particularly preferably 4000 mPa·s or more. The viscosity of the curable silicone composition according to the present invention may be, for example, 20,000 mPa·s or less at 25° C., preferably 18,000 mPa·s or less, more preferably 15,000 mPa·s or less, and even more preferably 12,000 mPa·s or less. In this specification, the viscosity can be measured at 25° C. using a rotational viscometer in accordance with JIS K7117-1.

[0027] The curable silicone composition according to the present invention can be cured to form a cured product with high hardness. Preferably, the cured product obtained by curing the curable silicone composition according to the present invention has a Type D durometer hardness at 25°C of 20 or more, or 30 or more. The Type D durometer hardness is determined using a Type D durometer in accordance with JIS K 6253-1997 "Testing method for hardness of vulcanized rubber and thermoplastic rubber".

[0028] The curable silicone composition according to the present invention can be cured to form a cured product having good transparency. Specifically, the cured product of the curable silicone composition according to the present invention preferably has a light transmittance of 80% or more at a wavelength of 400 nm to 700 nm, more preferably 90% or more, and particularly preferably 95% or more. The light transmittance of the cured product of the curable silicone composition can be determined, for example, by measuring the cured product with an optical path length of 1 mm using a spectrophotometer.

[0029] Each component will be described in detail below.

[0030] (A) Resin-like alkenyl-containing organopolysiloxane The component (A) has at least two alkenyl groups and at least one (SiO 4 / 2 The curable silicone composition according to the present invention may contain one type of component (A), or may contain a combination of two or more types of component (A).

[0031] In this specification, resin-like means having a branched or three-dimensional network structure in the molecular structure. The resin-like alkenyl group-containing organopolysiloxane of component (A) has at least one RSiO 4 / 2 Contains a siloxane unit (Q unit) represented by SiO 3 / 2 It may or may not contain a siloxane unit (T unit) represented by the following formula: but preferably it does not contain one.

[0032] Examples of the alkenyl group contained in component (A) include alkenyl groups having 2 to 12 carbon atoms, such as vinyl groups, allyl groups, butenyl groups, pentenyl groups, hexenyl groups, heptenyl groups, octenyl groups, nonenyl groups, decenyl groups, undecenyl groups, and dodecenyl groups, with vinyl groups being preferred.

[0033] Examples of groups bonded to silicon atoms other than alkenyl groups contained in component (A) include halogen-substituted or unsubstituted monovalent hydrocarbon groups other than alkenyl groups, such as alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl groups; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms, such as fluorine, chlorine, and bromine atoms. The silicon atoms in component (A) may contain small amounts of hydroxyl groups or alkoxy groups, such as methoxy and ethoxy groups, as long as the object of the present invention is not impaired. The groups bonded to silicon atoms in component (A) other than alkenyl groups are preferably selected from alkyl groups having 1 to 6 carbon atoms, and particularly methyl groups.

[0034] In one embodiment of the present invention, component (A) is (A-1) Average unit formula (I): (R 1 3SiO 1 / 2 ) a (R 1 2SiO 2 / 2 ) b (R 1 SiO 3 / 2 ) c (SiO 4 / 2 ) d (XO 1 / 2 ) e (In formula (I), R 1is the same or different halogen-substituted or unsubstituted monovalent hydrocarbon group, provided that in one molecule, at least two Rs 1 is an alkenyl group, and can be represented by 0 ≦ a < 1, 0 ≦ b < 1, 0 ≦ c < 0.9, 0 < d < 0.8, and 0 ≦ e < 0.4, where a + b + c + d = 1.0).

[0035] R in the above formula (I) 1 Examples of the halogen-substituted or unsubstituted monovalent hydrocarbon group of R include alkyl groups having 1 to 12 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group; aryl groups having 6 to 20 carbon atoms such as phenyl group, tolyl group, xylyl group, naphthyl group; aralkyl groups having 7 to 20 carbon atoms such as benzyl group, phenethyl group, phenylpropyl group; alkenyl groups having 2 to 12 carbon atoms such as vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group; groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine atom, chlorine atom, bromine atom. R 1 may be a small amount of hydroxyl group or alkoxy groups such as methoxy group and ethoxy group, as long as the object of the present invention is not impaired. R 1 is preferably selected from an alkyl group having 1 to 6 carbon atoms, particularly a methyl group, or an alkenyl group having 2 to 6 carbon atoms, particularly a vinyl group.

[0036] In the above formula (I), a is preferably in the range of 0.1≦a≦0.9, more preferably in the range of 0.3≦a≦0.6, and even more preferably in the range of 0.5≦a≦0.7. In the above formula (I), b is preferably in the range of 0≦b≦0.5, more preferably in the range of 0≦b≦0.3, and particularly in the range of 0≦b≦0.1. In the above formula (I), c is preferably in the range of 0≦c≦0.5, more preferably in the range of 0≦c≦0.3, and particularly in the range of 0≦c≦0.1. In the above formula (I), d is preferably in the range of 0.1≦d≦0.7, more preferably in the range of 0.2≦d≦0.6, and particularly in the range of 0.3≦d≦0.5. In the above formula (I), e is preferably in the range of 0≦e≦0.15, more preferably in the range of 0≦e≦0.1, and particularly in the range of 0≦e≦0.05.

[0037] In a preferred embodiment of the present invention, the resin-like alkenyl-containing organopolysiloxane of component (A) contains an alkenyl group at the molecular terminal. The resin-like organopolysiloxane of component (A) is preferably SiO 1 / 2 The siloxane unit (M unit) represented by the formula: 2 / 2 Siloxane units (D units) represented by the formula: and SiO 3 / 2 The siloxane unit (T unit) represented by the following formula (I) may or may not contain an alkenyl group, but preferably does not contain an alkenyl group.

[0038] In a preferred embodiment of the present invention, the resin-like alkenyl group-containing organopolysiloxane of component (A) preferably contains M units and SiO 4 / 2 and does not contain D units or T units. Therefore, in a preferred embodiment of the present invention, the component (A) is (A-2) Average unit formula (II): (R 1 3SiO 1 / 2 ) a (SiO 4 / 2 ) d (XO 1 / 2 ) e (In the formula, R1 is the same or different halogen-substituted or unsubstituted monovalent hydrocarbon group, provided that in one molecule, at least two Rs 1 is an alkenyl group, 0 ≦ a < 1, 0 < d < 0.8, and 0 ≦ e < 0.4, and a + d = 1.0).

[0039] Regarding the halogen-substituted or unsubstituted monovalent hydrocarbon group, a, d, and e in the above formula (II) are as described for the above formula (I), and the same description applies.

[0040] (A) The content of the alkenyl group in the total silicon atom-bonded organic groups is not particularly limited. For example, it is 1 mol% or more, preferably 2 mol% or more, more preferably 5 mol% or more of the total silicon atom-bonded organic groups, and can be 30 mol% or less, preferably 20 mol%, more preferably 15 mol% or less of the total silicon atom-bonded organic groups. The content of the alkenyl group can be determined by, for example, analytical methods such as Fourier transform infrared spectrophotometer (FT-IR), nuclear magnetic resonance (NMR), or the following titration method.

[0041] A method for quantifying the amount of alkenyl groups in each component by titration will be described. The alkenyl group content in the organopolysiloxane component can be accurately quantified by a titration method generally known as the Wijs method. The principle is described below. First, the alkenyl group in the organopolysiloxane raw material and iodine monochloride are subjected to an addition reaction as shown in formula (1). Next, by the reaction shown in formula (2), the excess iodine monochloride is reacted with potassium iodide to liberate iodine. Next, the liberated iodine is titrated with a sodium thiosulfate solution. Formula (1) CH2=CH- + 2ICl → CH2I-CHCl- + ICl (excess) Formula (2) ICl + KI → I2 + KCl The amount of alkenyl groups in the component can be quantified from the difference in the amount of sodium thiosulfate required for titration and the titration amount of a separately prepared blank solution.

[0042] The viscosity of the organopolysiloxane of the component (A) is not particularly limited, but is, for example, within the range of 50 mPa to 1000 mPa at 25° C. In this specification, the viscosity of the organopolysiloxane component can be measured at 25° C. using a rotational viscometer in accordance with JIS K7117-1.

[0043] The content of component (A) is not particularly limited, but is preferably 1 mass% or more, more preferably 2 mass% or more, even more preferably 3 mass% or more, and particularly preferably 4 mass% or more, based on the total mass of all organopolysiloxane components contained in the curable silicone composition of the present invention. Also, the content of component (A) is preferably 40 mass% or less, more preferably 35 mass% or less, even more preferably 30 mass% or less, and particularly preferably 25 mass% or less, based on the total mass of all organopolysiloxane components.

[0044] (B) Resin-like organohydrogenpolysiloxane Component (B) acts as a crosslinking agent for the curable silicone composition through a hydrosilylation curing reaction, and is a resin-like organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms per molecule and a resin-like structure. The curable silicone composition according to the present invention may contain one type of component (B), or may use a combination of two or more types of component (B).

[0045] The resinous organohydrogenpolysiloxane of component (B) contains at least one Q unit in its molecular structure, and may or may not contain T units, but preferably does not contain any.

[0046] As the group bonded to the silicon atom other than the hydrogen atom in the component (B), halogen-substituted or unsubstituted monovalent hydrocarbon groups other than alkenyl groups can be mentioned. For example, alkyl groups having 1 to 12 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group; aryl groups having 6 to 20 carbon atoms such as phenyl group, tolyl group, xylyl group, naphthyl group; aralkyl groups having 7 to 20 carbon atoms such as benzyl group, phenethyl group, phenylpropyl group; groups in which a part or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine atom, chlorine atom, bromine atom are exemplified. Note that the silicon atom in the component (B) may have a small amount of hydroxyl groups, alkoxy groups such as methoxy group and ethoxy group as long as the object of the present invention is not impaired. As the group bonded to the silicon atom other than the hydrogen atom in the component (B), preferably, an alkyl group having 1 to 6 carbon atoms, particularly a methyl group, is selected.

[0047] In one embodiment of the present invention, the component (B) is (B-1) Average unit formula (III): (R 2 3SiO 1 / 2 ) a (R 2 2SiO 2 / 2 ) b (R 2 SiO 3 / 2 ) c (SiO 4 / 2 ) d (XO 1 / 2 ) e (In the formula, R 2 is a hydrogen atom or a monovalent hydrocarbon group other than the same or different halogen-substituted or unsubstituted alkenyl group, provided that at least two R 2 are hydrogen atoms, X is a hydrogen atom or an alkyl group, and a, b, c, d, and e satisfy 0 ≦ a < 1.0, 0 ≦ b < 1.0, 0 ≦ c < 0.9, 0 < d < 0.8, 0 ≦ e < 0.4, and a + b + c + d = 1.0.) and can be a resinous organohydrogenpolysiloxane.

[0048] R in the above formula (III) 2 Examples of the halogen-substituted or unsubstituted monovalent hydrocarbon group other than an alkenyl group include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl groups; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms, such as fluorine, chlorine, and bromine atoms. 2 R may contain a small amount of hydroxyl groups or alkoxy groups such as methoxy groups and ethoxy groups, as long as the object of the present invention is not impaired. 2 is preferably selected from a hydrogen atom and an alkyl group having 1 to 6 carbon atoms, in particular a methyl group.

[0049] In the above formula (III) of the component (B), X is a hydrogen atom or an alkyl group. The alkyl group for X is preferably an alkyl group having 1 to 3 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, and a propyl group.

[0050] In the above formula (III), a is preferably in the range of 0.2≦a≦0.8, more preferably in the range of 0.3≦a≦0.7, and even more preferably in the range of 0.4≦a≦0.6. In the above formula (III), b is preferably in the range of 0≦b≦0.5, more preferably in the range of 0≦b≦0.3, and particularly in the range of 0≦b≦0.1. In the above formula (III), c is preferably in the range of 0≦c≦0.5, more preferably in the range of 0≦c≦0.3, and particularly in the range of 0≦c≦0.1. In the above formula (III), d is preferably in the range of 0.2≦d≦0.8, more preferably in the range of 0.3≦d≦0.7, and particularly in the range of 0.4≦d≦0.6. In the above (III), e is preferably in the range of 0≦e≦0.3, more preferably in the range of 0≦e≦0.2, and particularly in the range of 0≦e≦0.1.

[0051] Component (B) preferably contains silicon-bonded hydrogen atoms at the molecular terminals, and may or may not contain silicon-bonded hydrogen atoms in the molecular side chains, but preferably does not have silicon-bonded hydrogen atoms in the molecular side chains. Component (B) preferably contains silicon-bonded hydrogen atoms only at the molecular terminals. That is, in one embodiment of the present invention, component (B) has silicon-bonded hydrogen atoms in M ​​units, and preferably has silicon-bonded hydrogen atoms only in M ​​units. In another embodiment, component (B) may or may not contain T units and D units, but preferably does not contain them.

[0052] In a preferred embodiment of the present invention, component (B) contains a resin-like organohydrogenpolysiloxane (B-2) consisting only of M units and Q units, and this resin-like organohydrogenpolysiloxane (B-2) can be represented by the following average unit formula (IV). Average unit formula (IV): (R 2 3SiO 1 / 2 ) a (SiO 4 / 2 ) d (XO 1 / 2 ) e In the formula, R 2, X, a, d, and e are the same as those described in formula (III).

[0053] There are no particular limitations on the viscosity of the organopolysiloxane of component (B), but it is within the range of 1 mPa to 500 mPa at 25°C, for example.

[0054] The content of component (B) is not particularly limited, but is preferably 0.5 mass% or more, more preferably 1 mass% or more, even more preferably 1.5 mass% or more, and particularly preferably 2 mass% or more, based on the total mass of all organopolysiloxane components contained in the curable silicone composition of the present invention. Also, the content of component (B) is preferably 30 mass% or less, more preferably 20 mass% or less, and even more preferably 15 mass% or less, based on the total mass of all organopolysiloxane components.

[0055] <Other organopolysiloxane components> In addition to the above components (A) and (B), the curable silicone composition according to the present invention can also contain the following other organopolysiloxane components.

[0056] (Straight-chain alkenyl-containing organopolysiloxane) The curable silicone composition according to the present invention may contain a linear alkenyl group-containing organopolysiloxane in addition to the above components (A) and (B). The curable silicone composition according to the present invention may contain one type of linear alkenyl group-containing organopolysiloxane, or may contain a combination of two or more types of linear alkenyl group-containing organopolysiloxanes.

[0057] Examples of the alkenyl group contained in the linear alkenyl group-containing organopolysiloxane include alkenyl groups having 2 to 12 carbon atoms, such as a vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, and dodecenyl group, with a vinyl group being preferred.

[0058] In a preferred embodiment of the present invention, the linear alkenyl group-containing organopolysiloxane has at least one aryl group. The aryl group may be unsubstituted or substituted, and is preferably an aryl group having 6 to 20 carbon atoms, such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, and groups in which the hydrogen atoms of these aryl groups are substituted with alkyl groups such as a methyl group or an ethyl group; alkoxy groups such as a methoxy group or an ethoxy group; or halogen atoms such as a chlorine atom or a bromine atom. Particularly preferably, the aryl group is a substituted or unsubstituted phenyl group, and more preferably an unsubstituted phenyl group.

[0059] Examples of groups bonded to silicon atoms other than alkenyl groups and aryl groups contained in the linear alkenyl group-containing organopolysiloxane include halogen-substituted or unsubstituted monovalent hydrocarbon groups other than alkenyl groups and aryl groups. Examples include alkyl groups having 1 to 12 carbon atoms, such as methyl groups, ethyl groups, propyl groups, isopropyl groups, butyl groups, isobutyl groups, tert-butyl groups, pentyl groups, neopentyl groups, hexyl groups, cyclohexyl groups, heptyl groups, octyl groups, nonyl groups, decyl groups, undecyl groups, and dodecyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl groups, phenethyl groups, and phenylpropyl groups; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms, such as fluorine atoms, chlorine atoms, and bromine atoms.

[0060] Such linear alkenyl group-containing organopolysiloxanes have the following average structural formula (V): Average structural formula (V):R 3 3SiO(R 3 2SiO) m SiR 3 3 (In formula (V), R 3 are the same or different halogen-substituted or unsubstituted monovalent hydrocarbon groups, provided that at least two R 3 is an alkenyl group, and m is an integer of 4 to 1,000.

[0061] R 3 Examples of halogen-substituted or unsubstituted monovalent hydrocarbon groups include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl groups; alkenyl groups having 2 to 12 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl groups; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms, such as fluorine, chlorine, or bromine atoms.

[0062] In the above formula (V), m is preferably 10 or more, more preferably 40 or more, particularly preferably 70 or more, and is preferably 500 or less, more preferably 300 or less, even more preferably 200 or less, particularly preferably 120 or less.

[0063] In a preferred embodiment of the present invention, the additional linear alkenyl-containing organopolysiloxane may be a linear organopolysiloxane capped with alkenyl groups at both molecular chain ends, which contains alkenyl groups at both molecular chain ends. The additional linear organopolysiloxane may have a molecular chain side chain (i.e., SiO 2 / 2 The siloxane units (D units) represented by the following formula (I) may or may not contain an alkenyl group, but preferably do not contain an alkenyl group.

[0064] In a preferred embodiment of the present invention, the additional linear alkenyl group-containing organopolysiloxane contains a silicon atom-bonded aryl group at a molecular chain side chain. 1 / 2 The siloxane unit (M unit) represented by the following formula (I) may or may not contain an aryl group, but preferably does not contain an aryl group.

[0065] The content of alkenyl group in the total silicon-bonded organic group of linear alkenyl-containing organopolysiloxane is not particularly limited, but for example, it can be 0.01 mol% or more, preferably 0.1 mol% or more, more preferably 0.2 mol% or more of the total silicon-bonded organic group, and 30 mol% or less, preferably 20 mol%, more preferably 10 mol% or less of the total silicon-bonded organic group.The content of alkenyl group can be determined, for example, by Fourier transform infrared spectrophotometer (FT-IR), nuclear magnetic resonance (NMR), or other analytical method, or by the titration method described above.

[0066] The amount of aryl groups in the total silicon-bonded organic groups in the linear alkenyl-containing organopolysiloxane is not particularly limited, but may be, for example, 10 mol% or more, preferably 20 mol% or more, more preferably 30 mol% or more of the total silicon-bonded organic groups, and 70 mol% or less, preferably 60 mol%, more preferably 50 mol% or less of the total silicon-bonded organic groups.The content of alkenyl groups can be determined, for example, by analysis using a Fourier transform infrared spectrophotometer (FT-IR), nuclear magnetic resonance (NMR), etc.

[0067] The content of the linear alkenyl group-containing organopolysiloxane is not particularly limited, but is preferably 1 mass% or more, more preferably 2 mass% or more, even more preferably 3 mass% or more, and particularly preferably 4 mass% or more, based on the total mass of all organopolysiloxane components contained in the curable silicone composition of the present invention. Also, the content of the linear alkenyl group-containing organopolysiloxane is preferably 30 mass% or less, more preferably 20 mass% or less, and even more preferably 10 mass% or less, based on the total mass of all organopolysiloxane components.

[0068] (Resin-like alkenyl-containing organopolysiloxane not containing Q units) The curable silicone composition according to the present invention may contain, in addition to the above components (A) and (B), a resinous alkenyl-containing organopolysiloxane that does not contain Q units. The curable silicone composition according to the present invention may contain one type of resinous alkenyl-containing organopolysiloxane that does not contain Q units, or may contain a combination of two or more types of resinous alkenyl-containing organopolysiloxanes that do not contain Q units.

[0069] The resin-like alkenyl-containing organopolysiloxane that does not contain Q units can be a resin-like alkenyl-containing organopolysiloxane that contains at least two alkenyl groups in one molecule. Also, the resin-like alkenyl-containing organopolysiloxane that does not contain Q units may or may not contain at least one aryl group in one molecule. In a preferred embodiment, the resin-like alkenyl-containing organopolysiloxane that can be included in the present invention contains at least two alkenyl groups and at least one aryl group in one molecule.

[0070] A resinous alkenyl-containing organopolysiloxane that does not contain a Q unit contains at least one T unit in its molecular structure.

[0071] Examples of the alkenyl groups contained in the resin-like alkenyl-group-containing organopolysiloxane that does not contain Q units include the same alkenyl groups as those contained in the linear alkenyl-group-containing organopolysiloxane described above.

[0072] Such resin-like alkenyl-containing organopolysiloxanes have the following average unit formula (VI): Average unit formula (VI):(R 4 3SiO 1 / 2 ) a (R 4 2SiO 2 / 2 ) b (R 4 SiO 3 / 2 ) c (XO 1 / 2 ) e (In formula (VI), R4 is the same or different halogen-substituted or unsubstituted monovalent hydrocarbon group, provided that in one molecule, at least two Rs 4 is an alkenyl group, X is a hydrogen atom or an alkyl group, 0 ≦ a < 1, 0 ≦ b < 1, 0 < c < 0.9, and 0 ≦ e < 0.4, and a + b + c = 1.0).

[0073] In the above formula (VI), R 4 Examples of the halogen-substituted or unsubstituted monovalent hydrocarbon group of include alkyl groups having 1 to 12 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group; aryl groups having 6 to 20 carbon atoms such as phenyl group, tolyl group, xylyl group, naphthyl group; aralkyl groups having 7 to 20 carbon atoms such as benzyl group, phenethyl group, phenylpropyl group; alkenyl groups having 2 to 12 carbon atoms such as vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group; groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine atom, chlorine atom, bromine atom. R 4 may be a small amount of hydroxyl group, alkoxy groups such as methoxy group and ethoxy group, as long as the object of the present invention is not impaired. R 4 is preferably selected from aryl groups having 6 to 20 carbon atoms, particularly phenyl group, alkyl groups having 1 to 6 carbon atoms, particularly methyl group, or alkenyl groups having 2 to 6 carbon atoms, particularly vinyl group.

[0074] In the above formula (VI), X is a hydrogen atom or an alkyl group. As the alkyl group of X, an alkyl group having 1 to 3 carbon atoms is preferable, and specifically, methyl group, ethyl group, and propyl group are exemplified.

[0075] In the above formula (VI), a is preferably in the range of 0.1≦a≦0.8, more preferably in the range of 0.15≦a≦0.6, and even more preferably in the range of 0.2≦a≦0.5. In the above formula (VI), b is preferably in the range of 0≦b≦0.5, more preferably in the range of 0≦b≦0.3, and particularly in the range of 0≦b≦0.1. In the above formula (VI), c is preferably in the range of 0.3≦c≦0.9, more preferably in the range of 0.45≦c≦0.85, and particularly in the range of 0.6≦c≦0.8. In the above formula (VI), e is preferably in the range of 0≦e≦0.15, more preferably in the range of 0≦e≦0.1, and particularly in the range of 0≦e≦0.05.

[0076] The alkenyl-containing resin-like organopolysiloxane not containing Q units preferably contains an alkenyl group at the molecular end. Preferably, the alkenyl-containing resin-like organopolysiloxane not containing Q units has an alkenyl group in the M unit, and may or may not contain an alkenyl group in the D unit and / or T unit, but preferably does not. Also, the alkenyl-containing resin-like organopolysiloxane not containing Q units may or may not contain a D unit, but preferably does not contain one.

[0077] The content of alkenyl groups in the total silicon-bonded organic groups contained in the resinous alkenyl-containing organopolysiloxane that does not contain Q units is not particularly limited, but can be, for example, 1 mol% or more, preferably 2 mol% or more, more preferably 3 mol% or more of the total silicon-bonded organic groups, and can be 50 mol% or less, preferably 40 mol%, more preferably 35 mol% or less of the total silicon-bonded organic groups.The content of alkenyl groups can be determined, for example, by Fourier transform infrared spectrophotometer (FT-IR), nuclear magnetic resonance (NMR), or other analytical method, or by the titration method described above.

[0078] In one embodiment of the present invention, when the resinous alkenyl-containing organopolysiloxane not containing Q unit contains aryl group, the content of aryl group in the whole silicon-bonded organic group is not particularly limited, but for example, it can be 3 mol% or more, preferably 7 mol% or more, more preferably 10 mol% or more of the total silicon-bonded organic group, and 60 mol% or less, preferably 50 mol%, more preferably 40 mol% or less of the total silicon-bonded organic group.The content of aryl group can be determined by, for example, analysis such as Fourier transform infrared spectrophotometer (FT-IR) or nuclear magnetic resonance (NMR).

[0079] The content of the resinous alkenyl group-containing organopolysiloxane that does not contain Q units is not particularly limited, but is preferably 10 mass % or more, more preferably 20 mass % or more, and even more preferably 30 mass % or more, based on the total mass of all organopolysiloxane components in the curable silicone composition of the present invention, and can also be, for example, contained in an amount of 80 mass % or less, preferably 70 mass % or less, and more preferably 60 mass % or less, based on the total mass of all organopolysiloxane components.

[0080] (Linear organohydrogenpolysiloxane) The curable silicone composition according to the present invention may contain a linear organohydrogenpolysiloxane in addition to the above components (A) and (B). The curable silicone composition according to the present invention may contain one type of linear organohydrogenpolysiloxane, or may contain a combination of two or more types of linear organohydrogenpolysiloxane.

[0081] The linear organohydrogenpolysiloxane contains at least two silicon-bonded hydrogen atoms in one molecule, and preferably contains at least one aryl group in one molecule.

[0082] The aryl group that can be contained in the linear organohydrogenpolysiloxane may be unsubstituted or substituted, and is preferably an aryl group having 6 to 20 carbon atoms, such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, and groups in which the hydrogen atoms of these aryl groups are substituted with alkyl groups such as a methyl group or an ethyl group; alkoxy groups such as a methoxy group or an ethoxy group; or halogen atoms such as a chlorine atom or a bromine atom. Particularly preferably, the aryl group is a substituted or unsubstituted phenyl group, and more preferably an unsubstituted phenyl group.

[0083] Other silicon-bonded organic groups that may be contained in the linear organohydrogenpolysiloxane include halogen-substituted or unsubstituted monovalent hydrocarbon groups other than alkenyl groups, such as alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl groups; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms, such as fluorine, chlorine, and bromine atoms. In addition, the group may contain a small amount of hydroxyl groups or alkoxy groups, such as methoxy and ethoxy groups, within a range that does not impair the object of the present invention. The organic group bonded to a silicon atom contained in the linear organohydrogenpolysiloxane is preferably selected from an aryl group having 6 to 20 carbon atoms, particularly a phenyl group, or an alkyl group having 1 to 6 carbon atoms, particularly a methyl group.

[0084] In one embodiment of the present invention, when the curable silicone composition comprises a linear organohydrogenpolysiloxane, this linear organohydrogenpolysiloxane can be represented by the following average structural formula (VII): Average structural formula (VII):R 5 3SiO(R 5 2SiO) m SiR 5 3 In the formula, R 5 are hydrogen atoms or the same or different halogen-substituted or unsubstituted monovalent hydrocarbon groups other than alkenyl groups, provided that at least two R 5 is a hydrogen atom, and m is an integer of 1 to 100.

[0085] R in the above formula (VII) 5 Examples of the halogen-substituted or unsubstituted monovalent hydrocarbon group other than an alkenyl group include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl groups; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms, such as fluorine, chlorine, and bromine atoms. 5 R may contain a small amount of hydroxyl groups or alkoxy groups such as methoxy groups and ethoxy groups, as long as the object of the present invention is not impaired. 5 is preferably selected from a hydrogen atom, an aryl group having 6 to 20 carbon atoms, particularly a phenyl group, and an alkyl group having 1 to 6 carbon atoms, particularly a methyl group.

[0086] In the above formula (VII), m is preferably 50 or less, more preferably 20 or less, further preferably 10 or less, and particularly preferably 5 or less.

[0087] In a preferred embodiment of the present invention, the linear organohydrogenpolysiloxane contains silicon-bonded hydrogen atoms at both ends of the molecular chain. The linear organohydrogenpolysiloxane has silicon-bonded hydrogen atoms in the M units, and the D units may or may not contain silicon-bonded hydrogen atoms, but preferably do not contain them.

[0088] The additional linear organohydrogenpolysiloxane preferably contains silicon-bonded aryl groups at the molecular chain side chains. The linear organopolysiloxane may or may not contain aryl groups at the molecular chain terminals, but preferably does not contain them.

[0089] In one embodiment of the present invention, when the linear organohydrogenpolysiloxane contains an aryl group, the content of the aryl group in the entire silicon-bonded organic group is not particularly limited, but may be, for example, 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more of the total silicon-bonded organic group, and 50 mol% or less, preferably 40 mol%, more preferably 30 mol% or less of the total silicon-bonded organic group.The content of the aryl group can be determined, for example, by analysis such as Fourier transform infrared spectrophotometer (FT-IR) or nuclear magnetic resonance (NMR).

[0090] The content of the linear organohydrogenpolysiloxane is not particularly limited, but is preferably 3 mass % or more, more preferably 5 mass % or more, and even more preferably 10 mass % or more, based on the total mass of all organopolysiloxane components in the curable silicone composition of the present invention, and may be 30 mass % or less, more preferably 25 mass % or less, and even more preferably 20 mass % or less, based on the total mass of all organopolysiloxane components.

[0091] (Epoxy group-containing resin-like organopolysiloxane) In yet another embodiment, the curable silicone composition of the present invention may comprise an epoxy group-containing resinous organopolysiloxane having an average unit formula (VIII): (R 6 3SiO 1 / 2 ) a (R 6 2SiO 2 / 2 ) b (R 6 SiO 3 / 2 ) c (SiO 4 / 2 ) d (XO1 / 2 ) e (In the formula, R 6 are the same or different halogen-substituted or unsubstituted monovalent hydrocarbon groups or epoxy-containing organic groups, provided that at least one R 6 is an epoxy group-containing organic group, X is a hydrogen atom or an alkyl group, 0≦a<1, 0≦b<1, 0≦c<0.9, 0≦d<0.5, and 0≦e<0.4, a+b+c+d=1.0, and c+d>0.

[0092] In the above (VIII), R 6 is preferably selected from alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl groups; alkenyl groups having 2 to 12 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl groups; groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms, such as fluorine, chlorine, and bromine atoms, and epoxy group-containing organic groups. Examples of epoxy group-containing groups include glycidoxyalkyl groups such as a 2-glycidoxyethyl group, a 3-glycidoxypropyl group, and a 4-glycidoxybutyl group; epoxycycloalkylalkyl groups such as a 2-(3,4-epoxycyclohexyl)-ethyl group and a 3-(3,4-epoxycyclohexyl)-propyl group; and epoxyalkyl groups such as a 3,4-epoxybutyl group and a 7,8-epoxyoctyl group. Of these, preferred is a glycidoxyalkyl group, and particularly preferred is a 3-glycidoxypropyl group.

[0093] In the above formula (VIII), a is preferably in the range of 0≦a≦0.8, more preferably in the range of 0.05≦a≦0.6, and particularly in the range of 0.1≦a≦0.4. In the formula (X), b is preferably in the range of 0≦b≦0.9, more preferably in the range of 0.1≦b≦0.8, and particularly in the range of 0.2≦b≦0.7. In the formula (X), c is preferably in the range of 0≦c≦0.9, more preferably in the range of 0.1≦c≦0.85, and particularly in the range of 0.2≦c≦0.8. In the formula (X), d is preferably in the range of 0≦d≦0.7, more preferably in the range of 0≦d≦0.5, and even more preferably in the range of 0≦d≦0.2. In the formula (X), e is preferably in the range of 0≦e≦0.3, more preferably in the range of 0≦e≦0.2, and particularly in the range of 0≦e≦0.1.

[0094] In a preferred embodiment, the epoxy group-containing resinous organopolysiloxane is R 6 The amount of alkenyl groups in all silicon-bonded organic groups in the epoxy group-containing resinous organopolysiloxane is not particularly limited, but is preferably 1 mol % or more, more preferably 2 mol % or more, and even more preferably 3 mol % or more, and is, for example, 30 mol % or less, preferably 25 mol % or less, and more preferably 20 mol % or less.

[0095] In a preferred embodiment, the amount of epoxy-containing organic groups in the total silicon-bonded organic groups in the epoxy-containing resin-like organopolysiloxane is not particularly limited, but is preferably 1 mol% or more, more preferably 5 mol% or more, even more preferably 10 mol% or more, for example, 50 mol% or less, preferably 40 mol% or less, more preferably 30 mol% or less.The amount of epoxy-containing organic groups can be determined, for example, by analysis using a Fourier transform infrared spectrophotometer (FT-IR), nuclear magnetic resonance (NMR), etc.

[0096] The curable silicone composition according to the present invention may contain one type of epoxy group-containing resinous organopolysiloxane, or may contain a combination of two or more types of epoxy group-containing resinous organopolysiloxanes.

[0097] The amount of epoxy group-containing resinous organopolysiloxane is not particularly limited, but when the curable silicone composition of the present invention contains an epoxy group-containing resinous organopolysiloxane, it is preferably contained in an amount of 0.1 mass % or more, more preferably 0.5 mass % or more, and even more preferably 1 mass % or more, based on the total mass of all organopolysiloxane components, and may be contained in an amount of 10 mass % or less, more preferably 8 mass % or less, and even more preferably 5 mass % or less, based on the total mass of all organopolysiloxane components.

[0098] (Cyclic organopolysiloxane) In one embodiment, the curable silicone composition according to the present invention may include a cyclic organosiloxane, and the linear organosiloxane may be represented by the following unit formula (IX): Unit formula (IX): (R 7 2SiO) n In the formula, R 7 are each independently a halogen-substituted or unsubstituted monovalent hydrocarbon group, and n is a number that provides a viscosity of 1000 mPa or less at 25° C. The viscosity can be measured using a rotational viscometer in accordance with JIS K7117-1.

[0099] In the above formula (IX), R 7Examples of halogen-substituted or unsubstituted monovalent hydrocarbon groups include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl groups; alkenyl groups having 2 to 12 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl groups; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms, such as fluorine, chlorine, or bromine atoms. R 7 may contain a small amount of hydroxyl groups or alkoxy groups such as methoxy groups and ethoxy groups, as long as the object of the present invention is not impaired.

[0100] In one embodiment, cyclic organopolysiloxane can contain at least two alkenyl groups per molecule.When cyclic organopolysiloxane contains alkenyl group in silicon atom-bonded organic group, the amount of alkenyl group in silicon atom-bonded organic group as a whole is not particularly limited, but is, for example, 10 mol% or more, preferably 20 mol% or more, more preferably 30 mol% or more.In addition, the amount of alkenyl group in silicon atom-bonded organic group as a whole of additional cyclic organopolysiloxane is, for example, 80 mol% or less, preferably 70 mol% or less, more preferably 60 mol% or less.

[0101] The amount of cyclic organopolysiloxane is not particularly limited, but when the curable silicone composition of the present invention contains a cyclic organopolysiloxane, it is preferably contained in an amount of 1 mass % or more, more preferably 2 mass % or more, and even more preferably 3 mass % or more, based on the total mass of all organopolysiloxane components, and may be contained in an amount of 30 mass % or less, more preferably 20 mass % or less, and even more preferably 10 mass % or less, based on the total mass of all organopolysiloxane components.

[0102] In the curable silicone composition of the present invention, the ratio of silicon-bonded alkenyl groups to silicon-bonded hydrogen atoms contained in the organopolysiloxane component is not particularly limited, but for example, it can be an amount such that, per mole of silicon-bonded alkenyl groups in the curable silicone composition, there are at least 0.3 moles, preferably at least 0.5 moles, and more preferably at least 0.7 moles of silicon-bonded hydrogen atoms; and it can be, for example, an amount such that, per mole of silicon-bonded alkenyl groups in the curable silicone composition, there are no more than 5 moles, preferably no more than 4 moles, more preferably no more than 3 moles, even more preferably no more than 2 moles, and particularly preferably no more than 1.8 moles of silicon-bonded hydrogen atoms.

[0103] (C) Hydrosilylation reaction catalyst The hydrosilylation catalyst of component (C) is a catalyst for promoting the curing of the curable silicone composition of the present invention. Examples of such component (C) include platinum-based catalysts such as chloroplatinic acid, alcohol solution of chloroplatinic acid, complex of platinum and olefin, complex of platinum and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, and powder carrying platinum; palladium-based catalysts such as tetrakis(triphenylphosphine)palladium, palladium black, and mixture with triphenylphosphine; and rhodium-based catalysts, and particularly, platinum-based catalysts are preferred.

[0104] The amount of component (C) is a catalytic amount; more specifically, when a platinum-based catalyst is used as component (C), the amount of platinum atoms, relative to the total mass of the curable silicone composition of the present invention, is preferably at least 0.01 ppm, more preferably at least 0.1 ppm, and even more preferably at least 1 ppm; and the amount of platinum atoms, relative to the total mass of the curable silicone composition of the present invention, is preferably no more than 20 ppm, more preferably no more than 15 ppm, even more preferably no more than 10 ppm, and particularly preferably no more than 5 ppm.

[0105] (D) Curing reaction inhibitor The curing reaction inhibitor of component (D) is a component for suppressing the hydrosilylation reaction of the curable silicone composition. Examples of such curing reaction inhibitors include alkyne alcohols such as 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, 2-phenyl-3-butyn-2-ol, and 1-ethynyl-1-cyclohexanol; enyne compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexen-1-yne; alkenyl-containing low molecular weight siloxanes such as tetramethyltetravinylcyclotetrasiloxane and tetramethyltetrahexenylcyclotetrasiloxane; and alkynyloxysilanes such as methyl-tris(1,1-dimethylpropynyloxy)silane and vinyl-tris(1,1-dimethylpropynyloxy)silane. Preferably, component (D) is selected from alkyne alcohols, and particularly preferably 1-ethynyl-1-cyclohexanol.

[0106] There are no limitations on the content of (D) curing reaction inhibitor, but it is preferably at least 100 ppm, more preferably at least 200 ppm, even more preferably at least 300 ppm, and particularly preferably at least 400 ppm, relative to the total mass of the curable silicone composition of the present invention; and it is preferably no more than 50,000 ppm, more preferably no more than 30,000 ppm, and even more preferably no more than 20,000 ppm, relative to the total mass of the composition.

[0107] The curable silicone composition of the present invention may contain optional components within the scope of the present invention, such as acetylene compounds, organic phosphorus compounds, vinyl group-containing siloxane compounds, inorganic fillers such as ground quartz, silica, titanium oxide, magnesium carbonate, zinc oxide, iron oxide, and diatomaceous earth, inorganic fillers obtained by subjecting the surfaces of such inorganic fillers to hydrophobic treatment with organic silicon compounds, organopolysiloxanes that do not contain silicon-bonded hydrogen atoms and silicon-bonded alkenyl groups, adhesion-imparting agents, heat resistance-imparting agents, cold resistance-imparting agents, thermally conductive fillers, flame retardant agents, thixotropy-imparting agents, fluorescent materials, coloring components such as pigments and dyes, such as carbon black, and solvents.

[0108] Among the inorganic fillers, examples of silica include fumed silica, wet silica, crystalline silica, precipitated silica, etc. In addition, the silica may be surface-hydrophobized with an organosilicon compound such as an organoalkoxysilane compound, an organochlorosilane compound, an organosilazane compound, or a low-molecular-weight siloxane compound, or a silane coupling agent, a titanate coupling agent, or the like.

[0109] The inorganic filler can be contained in the curable silicone composition of the present invention in an amount of preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, based on the total mass of the composition of the present invention, and can be contained in the curable silicone composition of the present invention in an amount of preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.

[0110] The curable silicone composition of the present invention can be prepared by mixing each component. The method of mixing each component can be a conventionally known method and is not particularly limited, but usually a homogeneous mixture can be obtained by simple stirring. In addition, when a solid component such as an inorganic filler is included as an optional component, mixing using a mixing device is more preferable. Such a mixing device is not particularly limited, and examples thereof include a single-shaft or double-shaft continuous mixer, a three-roll mixer, a Ross mixer, a Hobart mixer, a dental mixer, a planetary mixer, a kneader mixer, and a Henschel mixer.

[0111] The curable silicone composition of the present invention shows practically effective curability even at low temperatures, has low shape change and shrinkage during curing, and can be cured in a short time to form a cured product. Therefore, the curable silicone composition of the present invention does not need to be heated at high temperatures for a long time during curing, so that deformation of the encapsulation shape during curing can be prevented by heating at a low temperature for a short time. In addition, the curable silicone composition of the present invention can form a transparent cured product with high hardness. Therefore, it is particularly useful as an encapsulant for semiconductor elements, especially optical semiconductor elements.

[0112] [Sealing materials, films] The present invention also relates to a semiconductor encapsulant using the curable silicone composition of the present invention.The shape of the encapsulant of the present invention is not particularly limited, but is preferably dome-shaped or sheet-shaped.The semiconductor encapsulated by the encapsulant or film of the present invention is not particularly limited, and examples thereof include semiconductors such as SiC and GaN, particularly power semiconductors or optical semiconductors such as light-emitting diodes.

[0113] According to the encapsulant of the present invention, since the curable silicone composition of the present invention is used, it shows practically effective curing properties even at low temperatures, and therefore it is possible to encapsulate semiconductor elements at low temperatures. Therefore, it is possible to prevent the encapsulant from being deformed by heating at high temperatures, and the semiconductor element from being damaged by heat. In addition, according to the encapsulant of the present invention, since the curable silicone composition of the present invention is used, it is possible to form a transparent cured product with high hardness. It is possible to manufacture a semiconductor package with excellent reliability.

[0114] [Optical semiconductor element] The present invention also relates to an optical semiconductor element comprising the encapsulant of the present invention. Examples of the optical semiconductor element include a light emitting diode (LED), a semiconductor laser, a photodiode, a phototransistor, a solid-state image sensor, and a light emitter and a light receiver for a photocoupler, and a light emitting diode (LED) is particularly preferred.

[0115] Since light emitting diodes (LEDs) emit light from the top, bottom, left and right of the optical semiconductor element, it is preferable that the components constituting the light emitting diode (LED) are not light absorbing, and are preferably made of materials with high light transmittance or high reflectance. Therefore, it is preferable that the substrate on which the optical semiconductor element is mounted is also made of materials with high light transmittance or high reflectance. Examples of substrates on which such optical semiconductor elements are mounted include conductive metals such as silver, gold, and copper; non-conductive metals such as aluminum and nickel; thermoplastic resins mixed with white pigments such as PPA and LCP; thermosetting resins containing white pigments such as epoxy resins, BT resins, polyimide resins, and silicone resins; and ceramics such as alumina and alumina nitride.

[0116] The optical semiconductor element of the present invention is encapsulated with the encapsulant of the present invention and therefore has excellent reliability. EXAMPLES

[0117] The curable silicone composition of the present invention will be described in more detail below with reference to the following examples and comparative examples.

[0118] [Examples 1 to 4 and Comparative Examples 1 to 4] The components were mixed in the composition (parts by weight) shown in the table to prepare a curable silicone composition. In the following, Me represents a methyl group, Vi represents a vinyl group, Ph represents a phenyl group, and Ep represents a 3-glycidoxypropyl group. In addition, the structure of the organopolysiloxane component is shown in a simplified form in the table, and the functional groups other than Me in the M, D, or T units are shown in parentheses. In addition, H / Vi represents the molar ratio of silicon-bonded hydrogen atoms (H) to vinyl groups (Vi) in the organopolysiloxane component.

[0119] (Component a: Alkenyl-containing organopolysiloxane) Component a-1: Average structural formula ViMe2SiO(PhMeSiO) 20 Linear alkenyl-containing organopolysiloxane represented by SiMe2Vi Component a-2: Average structural formula ViMe2SiO(Me2SiO) 60 (Ph2SiO)30 Linear alkenyl-containing organopolysiloxane represented by SiMe2Vi Component a-3: Average unit formula (Me3SiO 1 / 2 )5(ViMe2SiO 1 / 2 ) 17 (MeSiO 3 / 2 ) 39 (PhSiO 3 / 2 ) 39 The resin-like alkenyl-containing organopolysiloxane represented by the formula: Component a-4: Average unit formula (Me3SiO 1 / 2 ) 14 (ViMe2SiO 1 / 2 ) 11 (MeSiO 3 / 2 ) 53 (PhSiO 3 / 2 ) 22 The resin-like alkenyl-containing organopolysiloxane represented by the formula: Component a-5: Average unit formula (Me3SiO 1 / 2 ) 45 (ViMe2SiO 1 / 2 ) 15 (SiO 4 / 2 ) 40 The resin-like alkenyl-containing organopolysiloxane represented by the formula: Component a-6: Average unit formula (ViMe2SiO 1 / 2 ) 25 (PhSiO 3 / 2 ) 75 (EpMeSiO 2 / 2 ) 40 A resin-like alkenyl- and epoxy-containing organopolysiloxane represented by the formula: Component a-7: Average unit formula (ViMeSiO 2 / 2 ) Cyclic alkenyl group-containing organopolysiloxane represented by 4 Component a-8: Average unit formula (ViMe2SiO 1 / 2 ) 25 (PhSiO 3 / 2 ) 75 The resin-like alkenyl-containing organopolysiloxane represented by the formula: Component a-9: Average structural formula ViMe2SiO(Me2SiO) 150Linear alkenyl-containing organopolysiloxane represented by SiMe2Vi Component a-10: Average structural formula ViMe2SiO(Me2SiO) 530 Linear alkenyl-containing organopolysiloxane represented by SiMe2Vi Component a-11: Average unit formula (ViMe2SiO 1 / 2 ) 11 (Me3SiO 1 / 2 ) 34 (SiO 4 / 2 ) 55 The resin-like alkenyl-containing organopolysiloxane represented by the formula: (Component B: Organohydrogenpolysiloxane) Component b-1: Average unit formula (HMe2SiO 1 / 2 ) 60 (PhSiO 3 / 2 ) 40 Resin-like organohydrogenpolysiloxane represented by the formula: Component b-2: Average unit formula (HMe2SiO 1 / 2 )(SiO 4 / 2 ) Resin-like organohydrogenpolysiloxane represented by the formula: Component b-3: Linear organohydrogenpolysiloxane represented by the average structural formula HMe2SiO(Ph2SiO)SiMe2H Component b-4: Average structural formula Me3SiO(MeHSiO) 50 Linear organohydrogenpolysiloxane represented by SiMe3 Component c: A complex of platinum and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane having a platinum concentration of 4.0 mass% Component d: 1-ethynyl-2-cyclohexanol Component e: Fumed silica

[0120] [evaluation] The obtained curable silicone compositions of the Examples and Comparative Examples were evaluated for viscosity, curability at low temperatures (60, 100°C), change in shape before and after curing, heat shrinkage, hardness of the cured product, light transmittance of the cured product, and appearance after aging (150°C) on an LED device, as described below. Note that the composition of Comparative Example 4 was not evaluated as follows, since the components were incompatible.

[0121] <Viscosity> The viscosity of the resulting curable silicone composition was measured at 25° C. using a rotational viscometer in accordance with JIS K7117-1.

[0122] <Curing at low temperatures> The obtained curable silicone compositions were evaluated for their curing behavior at low temperatures (60 or 100°C). Specifically, the compositions were left in a thermostatic chamber at 60°C or 100°C for a predetermined period of time, and the time it took for the composition to cure was measured. Silicones that cured within 1 hour at 60°C or 100°C were determined to be silicones suitable for molding.

[0123] <Shape change> The obtained curable silicone composition was applied to a glass substrate by dispense molding to a height of about 1 mm, and the silicone was cured in a thermostatic chamber at 100°C for 60 minutes. The change in height of the cured product was measured, and the rate of shape change before and after curing was calculated. Silicones with a change in height of 10% or less were considered to be shape-stable.

[0124] <Heat shrinkage rate> The obtained curable silicone composition was molded into a 1 mm thick sheet by heating for 60 minutes in a hot press at 60°C or 100°C (if the composition was not completely cured in 60 minutes at 100°C, the composition was heated to 150°C). After curing, the dimensions of the sheet were measured and the shrinkage rate from the mold was calculated. The inside dimensions of the mold were 120mm x 120mm. Silicones with a shrinkage rate of 1% or less were considered suitable for dimensional stability.

[0125] <Hardness of the cured product> The resulting curable silicone composition was press-molded for 60 minutes at 60° C. or 100° C. to produce a sheet-like cured product. The hardness of this sheet-like cured product at 25° C. was measured using a Type D durometer as specified in JIS K 6253-1997 "Testing method for hardness of vulcanized rubber and thermoplastic rubber."

[0126] <Light transmittance of cured product> The obtained curable silicone composition was placed between two transparent glass plates and cured by heating at 60°C or 100°C for 1 hour to prepare a test specimen with an optical path length of 1 mm. The light transmittance of this test specimen was measured at 25°C using a recording spectrophotometer capable of measuring at any wavelength in the range of visible light (wavelengths of 400 nm to 700 nm). Table 1 shows the light transmittance value at a wavelength of 450 nm.

[0127] <Appearance observation of cured product after aging> The obtained curable silicone composition was applied onto an LED substrate and molded by heating for 60 minutes in a thermostatic chamber at 60 or 100°C. The obtained sheet was aged at 150°C for 1000 hours, after which the appearance was observed to check for the presence or absence of cracks or delamination.

[0128] The above evaluation results are shown in the table below.

[0129] [Table 1]

[0130] As can be seen from the above results, the curable silicone composition of the present invention cures within 60 minutes at low temperatures, and therefore exhibits practically effective curing properties even at low temperatures. Furthermore, the resulting cured product exhibits little change in shape or shrinkage upon curing, as well as high hardness and transparency. [Industrial Applicability]

[0131] The curable silicone composition of the present invention exhibits practically effective curability even at low temperatures, has a low shrinkage during curing, can cure in a short time, and provides a transparent cured product with high hardness, making it extremely useful as a dome- or sheet-shaped encapsulant when producing semiconductor packages.

Claims

1. (A) a polyorganosiloxane having a viscosity in the range of 50 mPa to 1000 mPa at 25° C. and a content of 3% by mass or more and 40% by mass or less based on the total mass of all organopolysiloxane components, and at least two alkenyl groups and at least one (SiO ４／２ ) units, (B) a silicone oil having a viscosity in the range of 1 mPa to 500 mPa at 25° C. and containing at least two silicon-bonded hydrogen atoms and at least one (SiO ４／２ ) units, (C) a hydrosilylation reaction catalyst; (D) a curing reaction inhibitor, and (E) At least one aryl group is contained in one molecule, and (SiO ４／２ Resin-like alkenyl-containing organopolysiloxane not containing 1. A curable silicone composition comprising:

2. 2. The curable silicone composition according to claim 1, wherein (C) the hydrosilylation reaction catalyst is a platinum-based catalyst, and the amount of platinum atoms contained therein is 10 ppm or less, relative to the total mass of the curable silicone composition.

3. 3. The curable silicone composition according to claim 1, wherein the content of the curing reaction inhibitor (D) is 200 ppm or more, based on the total mass of the curable silicone composition.

4. 4. The curable silicone composition according to claim 1, further comprising a linear alkenyl group-containing organopolysiloxane that contains at least one aryl group in each molecule.

5. 5. The curable silicone composition according to claim 1, further comprising a linear organohydrogenpolysiloxane containing at least one aryl group in one molecule.

6. The curable silicone composition according to any one of claims 1 to 5, further comprising silica as an inorganic filler.

7. An encapsulant comprising the curable silicone composition according to any one of claims 1 to 6.

8. An optical semiconductor device comprising the encapsulant according to claim 7 .

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