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1. A phosphor-containing sheet having a storage modulus of 0.1 MPa or more at 25° C. and a storage modulus of less than 0.1 MPa at 100° C., wherein a resin main, component of the phosphor-containing sheet is a crosslinked product formed by subjecting a crosslinkable silicone composition containing at least the following compositions (A) to (D) to a hydrosilylation reaction;
(A) organopolysiloxane represented by an average unit formula:
(R12SiO2/2)a(R1SiO3/2)b(R2O1/2)c in which R1 is a phenyl group, an alkyl group or a cycloalkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, provided that 65 to 75 mol % of R1 is phenyl and 10 to 20 mol % of R1 is an alkenyl group, R2 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and a, b and c satisfy the relationship of 0.5≦a≦0.6, 0.4≦b≦0.5, 0≦c≦0.1 and a+b=1; (B) organopolysiloxane, 5 to 15 parts by weight with respect to 100 parts by weight of the component (A), represented by the general formula:
R33SiO(R32SiO)mSiR33 in which R3 is a phenyl group, an alkyl group or a cycloalkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, provided that 40 to 70 mol % of R3 is phenyl and at least one of R3s is an alkenyl group, and m is an integer of 5 to 50; (C) organotrisiloxane, in such an amount that a molar ratio of a hydrogen atom coupled with a silicon atom in this component to the total of the alkenyl group in the component (A) and the component (B) is 0.5 to 2, represented by the general formula:
(HR42SiO)2SiR42 in which R4 is a phenyl group, or an alkyl group or a cycloalkyl group having 1 to 6 carbon atoms, provided that 30 to 70 mol % of R4 is phenyl; and (D) a catalyst for a hydrosilylation reaction, in such an amount sufficient to promote a hydrosilylation reaction of the alkenyl groups in the component (A) and the component (B) with the hydrogen atom coupled with a silicon atom in the component (C). |
