Addition-curable silicone resin composition, silicone cured product, and optical device

Abstract

To provide an addition curable type silicone resin composition having a low refractive index from which a silicone cured product that has high transparency even in use under a high temperature condition after curing and has less hardness change and mass reduction is given.SOLUTION: An addition curable type silicone resin composition contains (A) organopolysiloxane having an alkenyl group bonded to a silicon atom and a group represented by CF3(CH2)a- bonded to a silicon atom, (B) organohydrogen polysiloxane having a hydrogen atom bonded to a silicon atom, (C) organopolysiloxane having a group represented by the following general formula (1) bonded to a silicon atom, and a group represented by CF3(CH2)a- bonded to a silicon atom, and (D) a platinum group metal-based catalyst.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an addition-curable silicone resin composition, a cured silicone product, and an optical device. [Background technology]

[0002] Silicone resins into which fluorine atoms have been introduced have a low refractive index and excellent solvent resistance and water repellency, and are therefore applied to electronic devices such as light-emitting diode elements (Patent Documents 1 and 2). On the other hand, fluorosilicone resins normally have fluoroalkyl groups on the siloxane side chains, with trifluoropropyl groups (CF3(CH2)2-) being the most commonly used due to cost and manufacturing considerations. However, when these fluoroalkyl groups are exposed to high temperatures, they are oxidized and eliminated, causing a significant weight loss and also becoming a factor in the generation of cracks due to changes in hardness.

[0003] Known methods for imparting heat resistance to silicone resins include adding cerium oxide and adding a polyorganometallosiloxane obtained by reacting a cerium-containing rare earth carboxylate, a titanium alkoxide compound, and an organopolysiloxane having a fluoroalkyl group (Patent Document 3).

[0004] However, the addition of particulate cerium oxide can sometimes impair the transparency of the silicone resin, and while the use of organometallosiloxanes as heat resistance imparting agents shows excellent results in terms of suppressing changes in light transmittance and mass in heat resistance tests of fluorosilicone resins, improvements in terms of changes in hardness have been desired. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-010881 A [Patent Document 2] JP 2015-168698 A [Patent Document 3] JP 2020-196772 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in order to solve the above problems, and has an object to provide an addition-curable silicone resin composition that has a low refractive index and that, after curing, gives a silicone cured product that is highly transparent and experiences little hardness change or mass loss, even when used under high temperature conditions. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides (A) One or more silicon-bonded alkenyl groups and one or more silicon-bonded CF3(CH2) groups in one molecule a An organopolysiloxane having a group represented by - (wherein a is an integer of 2 or more) and not having a group represented by the following general formula (1): (B) an organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms in one molecule and not having a group represented by the following general formula (1): (C) A compound having a group represented by the following general formula (1) bonded to 1 to 10 silicon atoms in one molecule, and CF3(CH2) bonded to one or more silicon atoms in one molecule: a - (wherein a is an integer of 2 or more), (D)Platinum group metal catalyst Contains The present invention provides an addition-curable silicone resin composition in which the total number of hydrogen atoms bonded to silicon atoms in components (B) and (C) is 0.5 to 5.0 times the total number of alkenyl groups bonded to silicon atoms in components (A) and (C). [ka] (In the formula, R is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. The dashed line indicates a bond to the silicon atom.)

[0008] This addition-curable silicone resin composition has a low refractive index, and when cured, gives a silicone cured product that has excellent light transmittance at a wavelength of about 400 nm even when used under high temperature conditions, and that also exhibits little change in hardness or mass loss.

[0009] In the addition-curable silicone resin composition of the present invention, the above a is preferably 2.

[0010] When the above component (A) and the above component (C) are organopolysiloxanes having the specific fluoroalkyl groups, the addition-curable silicone resin composition has a low refractive index and, after curing, gives a silicone cured product that has excellent light transmittance at a wavelength in the vicinity of 400 nm when used under high temperature conditions and that experiences less change in hardness and less loss in mass.

[0011] In addition, R in the general formula (1) is preferably a hydrogen atom or a methyl group.

[0012] When component (C) is an organopolysiloxane having a group represented by the specific general formula (1) above, the addition-curable silicone resin composition has a low refractive index and, after curing, gives a silicone cured product that has excellent light transmittance at a wavelength in the vicinity of 400 nm when used under high temperature conditions and that experiences less change in hardness and less loss in mass.

[0013] In addition, it is preferable that the viscosity of the component (C) at 23° C. is 1,000 mPa·s or less.

[0014] Such a component (C) has excellent compatibility with components (A) and (B).

[0015] In addition, in the addition-curable silicone resin composition of the present invention, the refractive index of light with a wavelength of 589 nm at 25° C. is preferably less than 1.40.

[0016] In this way, when the addition-curable silicone resin composition has a refractive index less than the above-mentioned predetermined value, this addition-curable silicone resin composition gives a silicone cured product with superior light extraction efficiency.

[0017] The present invention also provides a silicone cured product which is a cured product of the above addition-curable silicone resin composition.

[0018] This silicone cured product has excellent light transmittance at wavelengths around 400 nm even when used under high temperature conditions, and also exhibits little change in hardness or mass loss.

[0019] Furthermore, in the silicone cured product of the present invention, the transmittance of light with a wavelength of 400 nm over an optical path length of 2 mm is preferably 80% or higher.

[0020] A silicone cured product that exhibits a light transmittance equal to or greater than the above-mentioned predetermined level exhibits excellent light transmittance at wavelengths around 400 nm even when used under high temperature conditions.

[0021] It is also preferable that the mass retention rate after 200 hours at 200° C. is 90% or more and the rate of change in type A hardness is 40% or less.

[0022] A silicone cured product that satisfies the above-mentioned mass retention rate and hardness change rate is suitable for use under high temperature conditions.

[0023] The present invention also provides an optical device comprising the above-mentioned silicone cured product.

[0024] Such optical devices are highly reliable because they use the above-mentioned silicone cured product. Effect of the Invention

[0025] The addition-curable silicone resin composition of the present invention has a low refractive index, and after curing, it gives a cured product that has excellent light transmittance at a wavelength of about 400 nm even when used under high temperature conditions, and has little change in hardness or mass loss. Therefore, the addition-curable silicone resin composition of the present invention is particularly useful as a material for protecting and sealing LED elements, a material for changing and adjusting wavelengths, a die bonding material, or a material for lenses, or a material for other optical devices or optical parts. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] As described above, there has been a need for the development of an addition-curable silicone resin composition that has a low refractive index, is excellent in light transmittance at wavelengths around 400 nm when used under high temperature conditions, and gives a cured product with little change in hardness and little loss in mass.

[0027] As a result of intensive research into the above-mentioned problems, the present inventors have found that an addition-curable silicone resin composition containing the following components (A) to (D) can achieve the above-mentioned problems and is suitable as a material for optical devices, etc., and have completed the present invention.

[0028] That is, the present invention provides: (A) One or more silicon-bonded alkenyl groups and one or more silicon-bonded CF3(CH2) groups in one molecule a An organopolysiloxane having a group represented by - (wherein a is an integer of 2 or more) and not having a group represented by the following general formula (1): (B) an organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms in one molecule and not having a group represented by the following general formula (1): (C) A compound having a group represented by the following general formula (1) bonded to 1 to 10 silicon atoms in one molecule, and CF3(CH2) bonded to one or more silicon atoms in one molecule: a - (wherein a is an integer of 2 or more), (D)Platinum group metal catalyst Contains This is an addition-curable silicone resin composition in which the total number of hydrogen atoms bonded to silicon atoms in components (B) and (C) is 0.5 to 5.0 times the total number of alkenyl groups bonded to silicon atoms in components (A) and (C). [ka] (In the formula, R is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. The dashed line indicates a bond to the silicon atom.)

[0029] The present invention will be described in detail below, but the present invention is not limited thereto.

[0030] [Addition-curable silicone composition] The addition-curable silicone resin composition of the present invention contains the following components (A) to (D). (A) One or more silicon-bonded alkenyl groups and one or more silicon-bonded CF3(CH2) groups in one molecule a An organopolysiloxane having a group represented by - (wherein a is an integer of 2 or more) and not having a group represented by the following general formula (1): (B) an organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms in one molecule and not having a group represented by the following general formula (1): (C) A compound having a group represented by the following general formula (1) bonded to 1 to 10 silicon atoms in one molecule, and CF3(CH2) bonded to one or more silicon atoms in one molecule: a - (wherein a is an integer of 2 or more), (D)Platinum group metal catalyst [ka] (In the formula, R is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. The dashed line indicates a bond to the silicon atom.)

[0031] Each component will be described in detail below.

[0032] <Component (A)> Component (A) is a compound that contains one or more silicon-bonded alkenyl groups and one or more silicon-bonded CF3(CH2) groups in one molecule. a - (where a is an integer of 2 or greater) and is an organopolysiloxane that does not have a group represented by general formula (1) above, and is therefore distinct from component (C) described below.

[0033] Examples of alkenyl groups bonded to silicon atoms include vinyl groups, allyl groups, butenyl groups, pentenyl groups, and hexenyl groups. Alkenyl groups having 2 to 10 carbon atoms, particularly 2 to 6 carbon atoms, are preferred, with vinyl groups being more preferred.

[0034] There may be one or more alkenyl groups bonded to silicon atoms in one molecule, but from the standpoint of curability and hardness of the resulting cured product, two or more are preferred.

[0035] CF3(CH2) bonded to silicon atom a In the - group, a is an integer of 2 or more, preferably 2 to 10, and more preferably 2 from the viewpoints of refractive index and availability of raw materials.

[0036] CF3(CH2) bonded to silicon atom a There may be one or more -- groups in one molecule, but from the viewpoint of refractive index, it is preferable that such groups account for 20% or more of the total number of substituents bonded to silicon atoms in component (A).

[0037] The component (A) is the above CF3(CH2) a In addition to the - group, there is also the CF3-(CF2) bonded to a silicon atom. b -(CH2) c-(wherein b is an integer of 1 or more and c is an integer of 0 or more), where b is preferably an integer satisfying 1≦b≦9 and c is preferably an integer satisfying 1≦c≦5, and from the viewpoints of availability of raw materials and production, it is more preferable that the group be CF3-(CF2)3-(CH2)2- or CF3-(CF2)5-(CH2)2-.

[0038] Substituents other than alkenyl and fluoroalkyl groups bonded to silicon atoms in component (A) are not particularly limited, but are preferably substituted or unsubstituted monovalent hydrocarbon groups having 1 to 8 carbon atoms. Examples of such monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, and butyl groups; cycloalkyl groups such as cyclohexyl and cyclopentyl groups; aryl groups such as phenyl, tolyl, and xylyl groups; aralkyl groups such as benzyl and phenylethyl groups; and chloroalkyl groups such as chloromethyl, chloropropyl, and chlorocyclohexyl groups. Alkyl groups are preferred, and methyl groups are more preferred.

[0039] The component (A) may be linear or branched, and may be liquid, waxy or solid, and may be used alone or in combination of two or more types.

[0040] The linear component (A) preferably has a viscosity at 23°C of 1 to 100,000 mPa·s or less, more preferably 1 to 10,000 mPa·s or less. A viscosity within this range provides better workability and a cured product with higher hardness. Unless otherwise specified below, the viscosity is measured using a B-type rotational viscometer at 23°C.

[0041] Specific examples of the linear component (A) include the following: [(CH2=CH)(CH3)2SiO 1 / 2 ]2[(CF3-CH2-CH2)(CH3)SiO] 30 [(CH2=CH)(CH3)2SiO 1 / 2][(CH3)3SiO 1 / 2 ][(CF3-CH2-CH2)(CH3)SiO] 35 [(CH2=CH)(CH3)2SiO 1 / 2 ]2[(CF3-CH2-CH2)(CH3)SiO] 50 [(CH3)2SiO] 20 [(CH2=CH)(CH3)2SiO 1 / 2 ]2[(CF3-CH2-CH2)(CH3)SiO] 30 [(C4F9-CH2-CH2)(CH3)SiO]2 (In the above formula, the siloxane units may be arranged in any order.)

[0042] From the standpoint of ease of isolation, the branched component (A) preferably has a weight average molecular weight in the range of 500 to 100,000.

[0043] Specific examples of the branched component (A) include those represented by the following average unit formulas. [(CH3)3SiO 1 / 2 ] 1.8 [(CH2=CH)(CH3)2SiO 1 / 2 ] 3.2 [SiO 4 / 2 ] 4.3 [(CF3-CH2-CH2)SiO 3 / 2 ] 10.0 [(CH3)3SiO 1 / 2 ] 1.3 [(CH2=CH)(CH3)2SiO 1 / 2 ] 2.3 [SiO 4 / 2 ] 3.9 [(CF3-CH2-CH2)SiO 3 / 2 ] 5.9 [(CH2=CH)(CH3)SiO 2 / 2 ] 2.1 [(CF3-CH2-CH2)SiO 3 / 2 ] 10.1 [(CH3)2SiO 2 / 2 ] 0.7 [(CH2=CH)(CH3)SiO 2 / 2 ] 2.1 [(CF3-CH2-CH2)SiO 3 / 2 ] 10.1 [(CF3-(CF2)3-CH2-CH2)(CH3)SiO 2 / 2 ] 0.7 (In the above formula, the siloxane units in parentheses may be arranged in any order.)

[0044] <(B) component> Component (B) is distinct from component (C), which will be described later, in that it is an organopolysiloxane that has two or more hydrogen atoms bonded to silicon atoms (i.e., SiH groups) in one molecule and does not have a group represented by the above general formula (1). Component (B) acts as a crosslinking agent that crosslinks with the alkenyl groups in component (A) through a hydrosilylation reaction.

[0045] The (B) component is not particularly limited as long as it is an organosilicon compound that has two or more hydrogen atoms bonded to silicon atoms in one molecule and does not have a group represented by the above general formula (1), and examples thereof include organohydrogensilanes and organohydrogenpolysiloxanes, with organohydrogenpolysiloxanes being preferred. There is no particular limit to the molecular structure of the organohydrogenpolysiloxane, and for example, linear, cyclic, and branched ones can be used.

[0046] The organic group bonded to silicon in component (B) preferably does not contain an alkenyl group, and examples thereof include unsubstituted monovalent hydrocarbon groups, and monovalent hydrocarbon groups substituted with halogen atoms (e.g., fluorine atoms, chlorine atoms, bromine atoms), epoxy group-containing groups (e.g., epoxy groups, glycidyl groups, glycidoxy groups), alkoxy groups (e.g., methoxy groups, ethoxy groups, propoxy groups, butoxy groups), etc. Examples of such substituted or unsubstituted monovalent hydrocarbon groups include alkyl groups having 1 to 6 carbon atoms, aryl groups having 6 to 10 carbon atoms, and more preferably methyl groups or ethyl groups, or groups in which these groups are substituted with the above-mentioned exemplary substituents. Furthermore, when the above-mentioned monovalent hydrocarbon group has an epoxy group-containing group and / or an alkoxy group as a substituent, adhesiveness can be imparted to the cured product of the silicone composition of the present invention.

[0047] In order to achieve a lower refractive index and to improve compatibility with component (A), the organic group bonded to silicon in component (B) is CF3(CH2). a - group (wherein a is an integer of 2 or greater).

[0048] Component (B) has at least 2 hydrogen atoms bonded to silicon atoms (SiH groups) per molecule, preferably 2 to 200, and more preferably 3 to 100. When the organosilicon compound of component (B) has a linear or branched structure, these SiH groups may be located either at the molecular chain terminals or non-terminal portions, or may be located at both.

[0049] The number of silicon atoms in one molecule of the organosilicon compound of component (B) (degree of polymerization) is preferably 2 to 1,000, more preferably 3 to 200, and even more preferably 4 to 100. Furthermore, the organosilicon compound of component (B) is preferably liquid at 23°C, and its viscosity at 23°C measured with a rotational viscometer is preferably 1 to 1,000 mPa s, and more preferably 10 to 100 mPa s.

[0050] The organosilicon compound of component (B) can be, for example, an organohydrogenpolysiloxane represented by the following average composition formula (2).

[0051] R 1 f H g SiO (4-f-g) / 2 (2) (In the formula, R 1 are the same or different, and are substituted or unsubstituted monovalent hydrocarbon groups not containing an alkenyl group, and f and g are numbers that satisfy 0.7≦f≦2.1, 0.001≦g≦1.0, and 0.8≦f+g≦3.0, preferably 1.0≦f≦2.0, 0.01≦g≦1.0, and 1.5≦f+g≦2.5.

[0052] R 1 As the substituted or unsubstituted monovalent hydrocarbon group not containing an alkenyl group, examples of the unsubstituted monovalent hydrocarbon group include an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, more preferably a methyl group or an ethyl group, or examples of monovalent hydrocarbon groups in which these groups are substituted with a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom), an epoxy group-containing group (e.g., an epoxy group, a glycidyl group, a glycidoxy group), an alkoxy group (e.g., a methoxy group, an ethoxy group, a propoxy group, a butoxy group), etc., can be mentioned. As such a substituted or unsubstituted monovalent hydrocarbon group, examples of the substituted monovalent hydrocarbon group include groups substituted with the above-mentioned exemplary substituents. In addition, when the above-mentioned monovalent hydrocarbon group has an epoxy group-containing group and / or an alkoxy group as a substituent, adhesiveness can be imparted to the cured product of the silicone composition of the present invention. In addition, from the viewpoint of further lowering the refractive index and achieving compatibility with component (A), R 1 As CF3(CH2) a - group (wherein a is an integer of 2 or greater).

[0053] Examples of organohydrogenpolysiloxanes represented by the above average composition formula (2) include those represented by the following formula:

[0054] (R 1 HSiO)4 (R 1 3SiO 1 / 2 )2(R 1 HSiO)8 (R 1 3SiO 1 / 2 )2(R 1 HSiO) 14 ((CF3-CH2-CH2)R 1 SiO) 14 (HR 1 2SiO 1 / 2 )2((CF3-CH2-CH2)R 1 SiO)5(R 1 2SiO)2 (In the above formula, R 1 is as above, and the order of arrangement of each siloxane unit is arbitrary.

[0055] The organohydrogenpolysiloxane represented by the above average composition formula (2) is represented by the formula: HSiO 1 / 2 A siloxane unit represented by the formula: R 1 Siloxane units represented by HSiO and / or the formula: R 1 2HSiO 1 / 2 The organohydrogenpolysiloxane may contain a siloxane unit represented by the following formula: The organohydrogenpolysiloxane may contain a triorganosiloxane unit (M unit) not containing a SiH group, a diorganosiloxane unit (D unit), a monoorganosiloxane unit (T unit), and / or SiO 4 / 2 R in the above formula may contain units (Q units). 1 is as stated above.

[0056] Specific examples of component (B) include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, tris(hydrogendimethylsiloxy)methylsilane, tris(hydrogendimethylsiloxy)phenylsilane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane-dimethylsiloxane cyclic copolymer, methylhydrogenpolysiloxane terminated at both molecular chain ends with trimethylsiloxy groups, and dimethyl terminated at both molecular chain ends with trimethylsiloxy groups. Siloxane-methylhydrogensiloxane copolymer, diphenylsiloxane-methylhydrogensiloxane copolymer terminated at both ends with trimethylsiloxy groups, methylphenylsiloxane-methylhydrogensiloxane copolymer terminated at both ends with trimethylsiloxy groups, dimethylsiloxane-methylhydrogensiloxane-methylphenylsiloxane copolymer terminated at both ends with trimethylsiloxy groups, dimethylsiloxane-methylhydrogensiloxane-methylphenylsiloxane copolymer terminated at both ends with trimethylsiloxy groups San-diphenylsiloxane copolymer, methylhydrogenpolysiloxane with both molecular ends blocked by dimethylhydrogensiloxy groups, dimethylpolysiloxane with both molecular ends blocked by dimethylhydrogensiloxy groups, dimethylsiloxane-methylhydrogensiloxane copolymer with both molecular ends blocked by dimethylhydrogensiloxy groups, dimethylsiloxane-methylphenylsiloxane copolymer with both molecular ends blocked by dimethylhydrogensiloxy groups, methylphenylsiloxane-diphenylsiloxane copolymer, methylphenylpolysiloxane terminated at both molecular chain ends with dimethylhydrogensiloxy groups, diphenylpolysiloxane terminated at both molecular chain ends with dimethylhydrogensiloxy groups, diphenylsiloxane-methylhydrogensiloxane copolymer terminated at both molecular chain ends with dimethylhydrogensiloxy groups, and organohydrogenpolysiloxanes in which some or all of the methyl groups in each of these exemplary compounds have been substituted with other alkyl groups such as ethyl groups or propyl groups, and the formula: R 1 3SiO 1 / 2 Siloxane units represented by the formula: R 1 2HSiO 1 / 2Siloxane units represented by the formula: SiO 4 / 2 and an organosiloxane copolymer having a siloxane unit represented by the formula: R 1 2HSiO 1 / 2 Siloxane units represented by the formula: SiO 4 / 2 and an organosiloxane copolymer having a siloxane unit represented by the formula: R 1 HSiO 2 / 2 Siloxane units represented by the formula: R 1 SiO 3 / 2 Siloxane units represented by the formula: HSiO 1 / 2 and mixtures of two or more of these organopolysiloxanes. 1 has the same meaning as above.

[0057] Preferred specific examples of the component (B) include those represented by the following unit formula:

[0058] [(CH3)3SiO 1 / 2 ]2[H(CH3)SiO]8 [(CH3)3SiO 1 / 2 ]2[(CF3-CH2-CH2)(CH3)SiO] 14 [H(CH3)SiO 2 / 2 ] 14 (In the above formula, the siloxane units in parentheses may be arranged in any order.)

[0059] The component (B) may use either a single compound, or a combination of two or more different compounds.

[0060] <(C) component> Component (C) has a group represented by the following formula (1) bonded to 1 to 10 silicon atoms in one molecule, and has CF3(CH2) bonded to one or more silicon atoms in one molecule. a- (where a is an integer of 2 or greater), and is a component that improves the heat resistance of addition-curable silicone resin compositions. The tetramethylpiperidinyl group contained in component (C) functions to trap oxygen radicals, suppressing deterioration caused by oxidation and elimination of the fluoroalkyl groups in components (A) and (B), and effectively suppressing increases in hardness and mass loss of the silicone cured product. Additionally, component (C) is CF3-(CH2) a The - group provides excellent compatibility with component (A) and high dispersibility in the composition, thereby enhancing the effect of imparting heat resistance. [ka] (In the formula, R is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. The dashed line indicates a bond to the silicon atom.)

[0061] In the above general formula (1), R is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, and is preferably a hydrogen atom or a methyl group.

[0062] Component (C) preferably has 1 to 10 groups represented by the above general formula (1) bonded to silicon atoms in one molecule, and this number is 50% or less of the total number of substituents bonded to silicon atoms in component (C). If this number exceeds 10, the compatibility with components (A) and (B) decreases, which may cause phase separation of the composition or a decrease in transparency.

[0063] Methods for introducing the group represented by the above general formula (1) into an organopolysiloxane include, for example, a method in which a tetramethylpiperidine derivative having a hydroxy group or substituted with a halogen such as chlorine is used as a raw material and reacted with an organopolysiloxane having a hydroxy group or a halogen atom bonded to a silicon atom in the presence of a base, and a method in which a tetramethylpiperidine derivative having a hydroxy group is reacted with chlorodimethylvinylsilane and then the vinyl group of the reaction product is added via a hydrosilylation reaction with a SiH group of an organohydrogenpolysiloxane.

[0064] CF3(CH2) bonded to silicon atom a In the - group, a is an integer of 2 or more, preferably 2 to 10, and more preferably 2 from the viewpoints of refractive index and availability of raw materials.

[0065] CF3(CH2) bonded to silicon atom a There may be one or more -- groups in each molecule, but from the standpoint of compatibility and refractive index, it is preferable that they account for 5% or more of the total number of substituents bonded to silicon atoms in component (C).

[0066] The component (C) is the above CF3(CH2) a In addition to the - group, there is also the CF3-(CF2) bonded to a silicon atom. b -(CH2) c -(wherein b is an integer of 1 or more and c is an integer of 0 or more), where b is preferably an integer satisfying 1≦b≦9 and c is preferably an integer satisfying 1≦c≦5, and from the viewpoints of availability of raw materials and production, it is more preferable that the group be CF3-(CF2)3-(CH2)2- or CF3-(CF2)5-(CH2)2-.

[0067] In addition, component (C) may contain an alkenyl group bonded to a silicon atom, in which case it can undergo a hydrosilylation reaction with component (B) in the same manner as component (A), to give a cured product with good dispersibility of component (C). Examples of the alkenyl group include the same alkenyl groups as those exemplified for component (A), with vinyl groups being preferred.

[0068] Furthermore, component (C) may contain silicon-bonded hydrogen atoms, which allows the component (C) to undergo a hydrosilylation reaction with component (A) in the same manner as component (B), thereby producing a cured product with good dispersion of component (C).

[0069] Substituents other than alkenyl and fluoroalkyl groups bonded to silicon atoms in component (C) are not particularly limited, but are preferably substituted or unsubstituted monovalent hydrocarbon groups having 1 to 8 carbon atoms. Examples of such monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, and butyl groups; cycloalkyl groups such as cyclohexyl and cyclopentyl groups; aryl groups such as phenyl, tolyl, and xylyl groups; aralkyl groups such as benzyl and phenylethyl groups; and chloroalkyl groups such as chloromethyl, chloropropyl, and chlorocyclohexyl groups. Alkyl groups are preferred, and methyl groups are more preferred.

[0070] Component (C) may be linear or branched, and has a viscosity at 23°C measured with a B-type rotational viscometer of preferably 1,000 mPa s or less, and more preferably 300 mPa s or less. If the viscosity is within this range, the compatibility with components (A) and (B) is excellent.

[0071] Specific examples of the component (C) include compounds represented by the following formula:

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] [ka] (In the formula, Me is a methyl group, and the siloxane units in the parentheses may be arranged in any order.)

[0079] The component (C) may be used alone or in combination of two or more types.

[0080] The amounts of the (B) and (C) components are such that the total number of hydrogen atoms (SiH groups) bonded to silicon atoms in the (B) and (C) components is 0.5 to 5.0 times the total number of alkenyl groups bonded to silicon atoms in the (A) and (C) components, and from the viewpoint of crosslinking balance, the amount is preferably 0.7 to 3.0 times. If the amount is less than 0.5 times or more than 5.0 times, crosslinking may proceed insufficiently or excessively, and a cured product with excellent hardness may not be obtained.

[0081] The amount of component (C) is preferably within the range of 0.01 to 5 parts by mass per 100 parts by mass of the total of components (A) and (B), which provides a cured product with excellent hardness and heat resistance.

[0082] <(D) component> The platinum group metal catalyst of component (D) is a component that promotes and accelerates the hydrosilylation reaction between the alkenyl groups in components (A) and (C) and the alkenyl groups in components (B) and (C).

[0083] The platinum group metal catalyst is not particularly limited, and examples thereof include platinum group metals such as platinum, palladium, and rhodium; platinum compounds such as chloroplatinic acid, alcohol-modified chloroplatinic acid, and coordination compounds of chloroplatinic acid with olefins, vinylsiloxanes, or acetylene compounds; and platinum group metal compounds such as tetrakis(triphenylphosphine)palladium and chlorotris(triphenylphosphine)rhodium. However, silicone-modified chloroplatinic acid is preferred because it has good compatibility with components (A) and (B) and contains almost no chlorine impurities.

[0084] The component (D) may use either a single compound, or a combination of two or more different compounds.

[0085] The amount of component (D) to be blended may be any amount effective as a catalyst, but is preferably 1 to 500 ppm, more preferably 3 to 100 ppm, and even more preferably 5 to 40 ppm, calculated as the mass of platinum group metal element, relative to the total of components (A) and (B). By adjusting this amount, the hydrosilylation reaction can be promoted more effectively.

[0086] <Other ingredients> The addition-curable silicone resin composition of the present invention may contain other components, such as those exemplified below, in addition to the above-mentioned components (A) to (D).

[0087] (Reaction inhibitor) In the addition curing silicone resin composition of the present invention, if necessary, a conventionally known reaction inhibitor (reaction control agent) that is a compound that has a curing suppression effect against the addition reaction catalyst of component (D) can be used. Examples of this reaction inhibitor include phosphorus-containing compounds such as triphenylphosphine, nitrogen-containing compounds such as tributylamine, tetramethylethylenediamine, and benzotriazole, sulfur-containing compounds, acetylene compounds, hydroperoxy compounds, and maleic acid derivatives.

[0088] Since the degree of the curing inhibition effect of the reaction inhibitor varies greatly depending on the chemical structure of the reaction inhibitor, it is preferable to adjust the amount of the reaction inhibitor to an optimal amount for each reaction inhibitor used. Usually, 0.001 to 5 parts by mass per 100 parts by mass of the total of components (A), (B), and (C) is preferable.

[0089] (Adhesion promoter) The addition curing type silicone resin composition of the present invention may contain an adhesion promoter for improving its adhesion. Examples of the adhesion promoter include silane coupling agents and their hydrolysis condensates. Examples of the silane coupling agent include known ones such as epoxy group-containing silane coupling agents, (meth)acrylic group-containing silane coupling agents, isocyanate group-containing silane coupling agents, isocyanurate group-containing silane coupling agents, amino group-containing silane coupling agents, and mercapto group-containing silane coupling agents, and the amount of the adhesion promoter is preferably 0.1 to 20 parts by mass, more preferably 0.3 to 10 parts by mass, per 100 parts by mass of the total of the (A) component, the (B) component, and the (C) component. The adhesion promoter may have the above-mentioned adhesive functional group and may contain an alkenyl group or a hydrogen atom bonded to a silicon atom. In this case, the adhesion promoter undergoes a hydrosilylation reaction with the (A) component, the (B) component, and the (C) component, and is incorporated into the reaction system.

[0090] (Filler) The addition-curable silicone resin composition of the present invention can be filled with inorganic fillers such as crystalline silica, hollow fillers, silsesquioxanes, and the like, as well as fillers obtained by subjecting these fillers to a surface hydrophobic treatment with organosilicon compounds such as organoalkoxysilane compounds, organochlorosilane compounds, organosilazane compounds, and low-molecular-weight siloxane compounds, silicone rubber powders, silicone resin powders, and the like. As this component, it is particularly preferable to use a filler that can impart thixotropy, and by imparting thixotropy, a silicone cured product with excellent workability and mechanical properties can be obtained.

[0091] <Refractive index of composition> The addition-curable silicone resin composition of the present invention preferably has a refractive index of less than 1.40 for light with a wavelength of 589 nm at 25° C. The refractive index (nD25) for light with a wavelength of 589 nm at 25° C. can be measured using a refractometer (RX-5000, manufactured by Atago Co., Ltd.).

[0092] [Cured product] Furthermore, the present invention provides a cured product of the addition-curable silicone resin composition (cured silicone product).

[0093] This silicone cured product is highly transparent even when used under high temperature conditions, and exhibits little change in hardness or mass loss, making it particularly useful as a material for optical devices such as encapsulants for LED elements. In particular, because the addition-curable silicone composition of the present invention contains fluoroalkyl groups and the like in components (A), (C), and optionally (B), it is possible to obtain a silicone cured product that has a low refractive index, high light transmittance, and excellent light extraction efficiency.

[0094] The silicone cured product of the present invention preferably has a transmittance of 80% or more for light with a wavelength of 400 nm at an optical path length of 2 mm.

[0095] The light transmittance can be measured by measuring the light transmittance of linear light having a wavelength of 400 nm at 25° C. using a spectrophotometer U-3900 (manufactured by Hitachi High-Tech Science Corporation).

[0096] The addition-curable silicone resin composition of the present invention may be cured under known conditions, for example at 100 to 180° C. for 10 minutes to 5 hours.

[0097] In addition, it is preferable that the silicone cured product of the present invention has a mass retention rate of 90% or more after heat treatment at 200°C for 200 hours, and a rate of change in Type A hardness (hardness) of 40% or less. It is more preferable that the rate of change in hardness is 40% or less. The Type A hardness of the silicone cured product at 25°C can be measured in accordance with JIS-K6249:2003.

[0098] The rate of change in hardness is calculated using the following formula. (Change rate %) = ((Hardness after 200 hours at 200°C) ÷ (Hardness immediately after preparation) × 100) - 100

[0099] [Optical devices] The present invention further provides an optical device comprising the above-mentioned cured silicone product.

[0100] The addition-curable silicone resin composition of the present invention can provide a silicone cured product that is highly transparent even when used under high-temperature conditions and that exhibits little change in hardness or mass loss, resulting in optical devices using this silicone cured product that are highly reliable. EXAMPLES

[0101] The present invention will be specifically described below using examples and comparative examples, but the present invention is not limited to these. In the following, the viscosity is a value measured at 23°C using a B-type rotational viscometer. The abbreviations for each siloxane unit have the following meanings.

[0102] M:(CH3)3SiO 1 / 2 M Vi :(CH2=CH)(CH3)2SiO 1 / 2 D: (CH3)2SiO 2 / 2 D H :H(CH3)SiO 2 / 2 D Vi :(CH=CH2)(CH3)SiO D F :(CF3-(CH2)2)(CH3)SiO T:(CH3)SiO 3 / 2 T F :(CF3-(CH2)2)SiO 3 / 2

[0103] [Synthesis Example 1] In a 500mL four-neck flask equipped with a stirrer, a cooling tube, a dropping funnel and a thermometer, 171g of 4-hydroxy-1,2,2,6,6-pentamethylpiperidine, 60g of toluene and 101.2g of triethylamine were added and stirred to obtain a homogeneous solution. 59.3g of vinyldimethylchlorosilane was then added dropwise and stirred at 25°C for 3 hours. 200g of 10% aqueous Glauber's salt was added to the resulting solution, stirred for 15 minutes to separate the Glauber's salt water and toluene, and the Glauber's salt water was then removed. This water washing process was then carried out three more times, after which 2g of Glauber's salt was added and dehydrated. After removing the Glauber's salt by paper filtration, the solution was distilled under reduced pressure at 80°C for 1 hour to remove the toluene, and a colorless and transparent liquid was obtained. It was confirmed by NMR measurement and gas chromatography that a compound represented by the following formula was obtained.

[0104] [ka]

[0105] [Synthesis Example 2] In a 500mL four-neck flask equipped with a stirrer, a cooling tube, a dropping funnel and a thermometer, 42.7g of 4-hydroxy-1,2,2,6,6-pentamethylpiperidine, 28g of toluene and 25.3g of triethylamine were added and stirred to form a homogeneous solution. 23.6g of dimethylchlorosilane was then added dropwise and stirred at 25°C for 3 hours. 200g of 10% aqueous Glauber's salt solution was added to the resulting solution, stirred for 15 minutes to separate the Glauber's salt solution and toluene, and the Glauber's salt solution was then removed. This water washing process was then carried out three more times, after which 2g of Glauber's salt was added and dehydrated. After removing the Glauber's salt by paper filtration, the solution was distilled under reduced pressure at 80°C for 1 hour to remove the toluene, and a colorless and transparent liquid was obtained. It was confirmed by NMR measurement and gas chromatography that a compound represented by the following formula was obtained.

[0106] [ka]

[0107] [Synthesis Example 3] In a 500mL four-neck flask equipped with a stirrer, a cooling tube, a dropping funnel and a thermometer, 157g of 4-hydroxy-2,2,6,6-tetramethylpiperidine, 60g of tetrahydrofuran and 101.2g of triethylamine were added and stirred to obtain a homogeneous solution. 59.3g of vinyldimethylchlorosilane was then added dropwise and stirred at 25°C for 3 hours. 200g of 10% aqueous Glauber's salt was added to the resulting solution, stirred for 15 minutes to separate the Glauber's salt water and toluene, and the Glauber's salt water was then removed. This water washing process was then carried out three more times, after which 2g of Glauber's salt was added and dehydrated. After removing the Glauber's salt by paper filtration, the solution was distilled under reduced pressure at 80°C for 1 hour to remove the toluene, and a colorless and transparent liquid was obtained. It was confirmed by NMR measurement and gas chromatography that a compound represented by the following formula was obtained.

[0108] [ka]

[0109] [Synthesis Example 4] In a 500 mL four-neck flask equipped with a stirrer, condenser, dropping funnel, and thermometer, add the building block M2D F 6D H 6.7 g of the linear organopolysiloxane represented by formula 4 and 1.7 g of hexafluorometa-xylene were added and dissolved uniformly, and then 0.013 g of a chloroplatinic acid toluene solution (platinum concentration 0.5%) was added. The mixture was heated to 80°C, and 1.3 g of the compound obtained in Synthesis Example 1 was added dropwise, and the mixture was allowed to react at 80°C for 5 hours. After cooling to 25°C, 0.04 g of activated carbon was added, and the mixture was stirred for 1 hour and filtered to obtain an organopolysiloxane represented by the following formula (C-1, pale yellow transparent liquid, viscosity 67 mPa s).

[0110] [ka] (In the formula, the order of the siloxane units in parentheses is not specified.)

[0111] [Synthesis Example 5] In a 500 mL four-neck flask equipped with a stirrer, condenser, dropping funnel, and thermometer, add the building block M2D F 6D Vi 5.5g of the linear organopolysiloxane represented by formula 4 and 1.5g of hexafluorometa-xylene were added and dissolved uniformly, and then 0.012g of a toluene solution containing 0.5% platinum atoms was added. After heating to 80°C, 0.8g of the compound obtained in Synthesis Example 2 was added dropwise and reacted at 80°C for 5 hours. After cooling to 25°C, 0.04g of activated carbon was added and stirred for 1 hour, and then filtered to obtain an organopolysiloxane represented by the following formula (C-2, pale yellow transparent liquid, viscosity 79mPa s).

[0112] [ka] (In the formula, the order of the siloxane units in parentheses is not specified.)

[0113] [Synthesis Example 6] In a 500 mL four-neck flask equipped with a stirrer, condenser, dropping funnel, and thermometer, add the building block M2D F 6D H 6.7 g of the linear organopolysiloxane represented by formula 4 and 1.7 g of hexafluorometa-xylene were added and dissolved uniformly, and then 0.013 g of a toluene solution containing 0.5% platinum atoms was added. After heating to 80°C, 1.4 g of the compound obtained in Synthesis Example 3 was added dropwise and reacted at 80°C for 5 hours. After cooling to 25°C, 0.04 g of activated carbon was added and the mixture was stirred for 1 hour and filtered to obtain an organopolysiloxane represented by the following formula (C-3, pale yellow transparent liquid, viscosity 85 mPa s).

[0114] [ka] (In the formula, the order of the siloxane units in parentheses is not specified.)

[0115] [Synthesis Example 7] In a 500 mL four-neck flask equipped with a stirrer, condenser, dropping funnel, and thermometer, add the building block D F46.8 g of the cyclic organopolysiloxane represented by formula 3, 36.1 g of nonafluorohexyldichlorosilane, and 0.58 g of hexamethylphosphoric triamide were added and reacted at 25° C. for 5 hours to obtain an intermediate.

[0116] Next, the above intermediate was dropped into a solution in which 34.1g of 4-hydroxy-1,2,2,6,6-pentamethylpiperidine, 20.2g of triethylamine, 29g of toluene, and 29.3g of hexafluorometaxylene were uniformly mixed, and the mixture was allowed to react at 25°C for 4 hours. 200g of 10% aqueous Glauber's salt was added to the resulting solution, and the mixture was stirred for 15 minutes to separate the Glauber's salt water and toluene, after which the Glauber's salt water was removed. This water washing process was then repeated three more times, after which 2g of Glauber's salt was added and the mixture was dehydrated. After the Glauber's salt was removed by paper filtration, the solution was distilled under reduced pressure at 120°C for 1 hour to remove the toluene, and an organopolysiloxane represented by the following formula (C-4, colorless, transparent liquid, viscosity 190mPa·s) was obtained.

[0117] [ka]

[0118] [Synthesis Example 8] To 100 parts by mass of dimethylpolysiloxane capped with trimethylsiloxy groups at both ends and having a viscosity of 100 mPa·s, 10 parts by mass (rare earth content 6% by mass) of a turpentine solution of 2-ethylhexanoate of rare earth elements, mainly cerium, (0.55 parts as cerium) and 2.1 parts by mass of tetra n-butyl titanate (titanium mass is 0.3 times the mass of cerium in the 2-ethylhexanoate) were added while stirring to obtain a yellowish white dispersion. This was heated while passing a small amount of nitrogen gas through it to flush out the turpentine, and then heated at 300°C for 1 hour to obtain a dark reddish brown transparent organometallosiloxane composition (C-5).

[0119] [Synthesis Example 9] [(CH3)3SiO 1 / 2 ]2[(CF3-(CH2)2)(CH3)SiO] 13To 100 parts by mass of polysiloxane (refractive index 1.38, viscosity 450 mPa·s), 10 parts by mass (rare earth content 6% by mass) of 2-ethylhexanoate of rare earth elements mainly composed of cerium in turpentine solution (0.55 parts as cerium) and 2.1 parts by mass of tetra n-butyl titanate (titanium mass is 0.3 times the mass of cerium in the above 2-ethylhexanoate) were added while stirring to obtain a yellowish white dispersion. This was heated while passing a small amount of nitrogen gas through it to flush out the turpentine, and then heated at 300°C for 1 hour to obtain a reddish brown transparent organometallosiloxane composition (C-6).

[0120] [Synthesis Example 10] 22.2 g of the cyclic organopolysiloxane represented by the structural unit D3, 12.9 g of dimethyldichlorosilane, and 0.58 g of hexamethylphosphoric triamide were placed in a 500 mL four-neck flask equipped with a stirrer, a condenser, a dropping funnel, and a thermometer, and the mixture was allowed to react at 25° C. for 5 hours to obtain an intermediate.

[0121] Next, the intermediate was added dropwise to a solution in which 34.1g of 4-hydroxy-1,2,2,6,6-pentamethylpiperidine, 20.2g of triethylamine, 29g of toluene, and 29.3g of hexafluorometaxylene were uniformly mixed, and the mixture was allowed to react at 25°C for 4 hours. 200g of 10% aqueous Glauber's salt was added to the resulting solution, and the mixture was stirred for 15 minutes to separate the aqueous Glauber's salt and toluene, after which the aqueous Glauber's salt was removed. This water washing process was then repeated three more times, after which 2g of Glauber's salt was added and the mixture was dehydrated. After the Glauber's salt was removed by paper filtration, the solution was distilled under reduced pressure at 120°C for 1 hour to remove the toluene, and an organopolysiloxane represented by the following formula (C-7, colorless, transparent liquid, viscosity 37mPa·s) was obtained.

[0122] [ka]

[0123] [Examples 1 to 5, Comparative Examples 1 to 6] The components listed below were mixed in the amounts (parts by mass) shown in Table 1 to prepare addition-curable silicone compositions.

[0124] (A) Component: (A-1)M Vi 2D F 27 A linear organopolysiloxane with a viscosity of 2,000 mPa·s, represented by the formula (A-2) Composition unit ratio T F / D Vi = 7 / 3, a branched organopolysiloxane with a weight average molecular weight of 1,900 (A-3)M Vi 2D F 161 D 70 A linear organopolysiloxane with a viscosity of 5,000 mPa·s. (A-4)M2D F 70 D 30 D Vi 10 A linear organopolysiloxane with a viscosity of 2,200 mPa·s.

[0125] (B) Ingredients: (B-1)M2D H Linear organohydrogenpolysiloxane represented by formula 8 (B-2)M2D H 14 D F 14 A linear organohydrogenpolysiloxane represented by the formula:

[0126] (C) Ingredients: (C-1) Organopolysiloxane obtained in Synthesis Example 4 (C-2) Organopolysiloxane obtained in Synthesis Example 5 (C-3) Organopolysiloxane obtained in Synthesis Example 6 (C-4) Organopolysiloxane obtained in Synthesis Example 7 (C-5) Organometallosiloxane composition obtained in Synthesis Example 8 (C-6) Organometallosiloxane composition obtained in Synthesis Example 9 (C-7) Organopolysiloxane obtained in Synthesis Example 10

[0127] (D) Ingredients: Toluene solution of a complex of hexachloroplatinic acid and 1,3-divinyltetramethyldisiloxane (platinum concentration 0.5% by mass)

[0128] (E) Ingredients: Ethynylcyclohexanol

[0129] The addition-curable silicone resin compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 6 were evaluated as follows. The results are shown in Table 2.

[0130] [exterior] The appearance of each composition was visually observed.

[0131] [Refractive index] The refractive index (nD25) of each composition at 25° C. for light with a wavelength of 589 nm was measured using a refractometer (RX-5000, manufactured by Atago Co., Ltd.).

[0132] [Hardness] The addition-curable silicone resin composition was heat-cured at 150°C for 2 hours to obtain a silicone cured product. The Type A hardness (hardness) of the silicone cured product at 25°C was measured in accordance with JIS-K6249:2003 immediately after production of the silicone cured product and after storing the silicone cured product for 200 hours in an environment of 200°C (Examples 1-4, Comparative Examples 1-5) or 230°C (Example 5, Comparative Example 6). The rate of change in hardness was calculated according to the following formula.

[0133] (% change) = ((Hardness after 200 hours at 200℃ or 230℃) ÷ (Hardness immediately after preparation) × 100) - 100

[0134] [Light transmittance] The addition-curable silicone resin composition was poured into a mold to a thickness of 2 mm, and heat-cured at 150°C for 2 hours to obtain a silicone cured product. The light transmittance of direct light with a wavelength of 400 nm at 25°C was measured using a spectrophotometer U-3900 (manufactured by Hitachi High-Tech Science Corporation) immediately after production of the silicone cured product, and after storing the silicone cured product in an environment at 200°C (Examples 1-4, Comparative Examples 1-5) or 230°C (Example 5, Comparative Example 6) for 200 hours.

[0135] [Remaining mass rate after heat resistance test] The initial mass of the silicone cured product used in the above light transmittance measurement was taken as 100, and the mass after storage for 200 hours in an environment of 200°C (Examples 1 to 4, Comparative Examples 1 to 5) or 230°C (Example 5, Comparative Example 6) was measured and the mass % after the heat resistance test was calculated.

[0136] [Table 1]

[0137] SiH group / alkenyl group: the number of SiH groups in components (B) and (C) per one alkenyl group bonded to a silicon atom in components (A) and (C) [Table 2]

[0138] 1) Measurement impossible due to cracks

[0139] As shown in Table 2, the cured products using the addition-curable silicone compositions of Examples 1 to 5 exhibited high light transmittance. In addition, even after the heat resistance test, there was little change in hardness, light transmittance, and mass, demonstrating excellent heat resistance.

[0140] On the other hand, since Comparative Examples 1, 2 and 6 did not contain a heat resistance imparting agent, the initial light transmittance was high, but the changes in hardness and mass due to heat were very large, and cracks occurred throughout the cured product, resulting in a cured product with poor heat resistance.

[0141] Comparative Example 3, which used an organometallosiloxane containing cerium and titanium and not having a fluoroalkyl group instead of the (C-4) component in Example 4, showed poor compatibility with the (A) and (B) components, reduced transparency, and a large change in hardness due to heat. Comparative Example 4, which used an organometallosiloxane containing cerium and titanium and having a fluoroalkyl group, showed good light transmittance, but a large change in hardness due to heat. Furthermore, Comparative Example 5, which used an organopolysiloxane having a piperidine skeleton but not a fluoroalkyl group, showed poor compatibility with the (A) and (B) components, reduced transparency, and a cured product with poor heat resistance.

[0142] The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention.

Claims

1. An addition-curable silicone resin composition, (A) One or more silicon-bonded alkenyl groups and one or more silicon-bonded CF ３ (CH ２ ) ａ - (wherein a is an integer of 2 or more) and does not have a group represented by the following general formula (1): (B) an organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms in one molecule and not having a group represented by the following general formula (1): (C) A compound having a group represented by the following general formula (1) bonded to 1 to 10 silicon atoms in one molecule, and having CF bonded to one or more silicon atoms in one molecule: ３ (CH ２ ) ａ - (wherein a is an integer of 2 or more), (D) Platinum group metal catalyst Contains An addition-curable silicone resin composition, characterized in that the total number of hydrogen atoms bonded to silicon atoms in components (B) and (C) is 0.5 to 5.0 times the total number of alkenyl groups bonded to silicon atoms in components (A) and (C). 【Chemistry 1】 (In the formula, R is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. The dashed line indicates a bond to the silicon atom.)

2. The addition-curable silicone resin composition according to claim 1, characterized in that the a in the (A) component and the (C) component are both 2.

3. 3. The addition-curable silicone resin composition according to claim 1, wherein R in the general formula (1) is a hydrogen atom or a methyl group.

4. 4. The addition-curable silicone resin composition according to claim 1, wherein the viscosity of component (C) at 23° C. is 1,000 mPa·s or less.

5. 5. The addition-curable silicone resin composition according to claim 1, wherein the refractive index of light with a wavelength of 589 nm at 25° C. is less than 1.

40.

6. A silicone cured product, which is a cured product of the addition-curable silicone resin composition according to any one of claims 1 to 5.

7. 7. The silicone cured product according to claim 6, which has a transmittance of 80% or more for light with a wavelength of 400 nm at an optical path length of 2 mm.

8. 8. The silicone cured product according to claim 6, wherein after 200 hours at 200° C., the mass retention rate is 90% or more and the rate of change in type A hardness is 40% or less.

9. An optical device comprising the silicone cured product according to any one of claims 6 to 8.

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