Curable hotmelt silicone composition, encapsulant, hotmelt adhesives, and optical semiconductor device

A curable hot-melt silicone composition, comprising:

• (A) a resinous alkenyl group-containing organopolysiloxane that includes at least two alkenyl groups and at least one aryl group per molecule, where the aryl group content is 40 mol % or more;
• (B) a curable linear organopolysiloxane that includes at least one aryl group per molecule, where the aryl group content is 40 mol % or more;
• (C) a curable linear or branched organopolysiloxane that includes at least one aryl group per molecule, where the aryl group content is from about 15 to about 32 mol %;
• (D) a silicone reactive compatibilizer having a weight-average molecular weight of 1000 or less, that is selected from:
• (D-1) cyclic organopolysiloxanes;
• (D-2) MQ resins;
• and (D-3) organopolysiloxanes different from component (A), that include at least one (ArSiO3/2) unit (Ar represents an aryl group) per molecule or that have an aryl group content of 20 mol % or less;
• (E) an organohydrogenpolysiloxane having at least 2 silicon atom-bonded hydrogen atoms per molecule, that is different from component (D);
• and
• (F) a curing catalyst,
• wherein
• the content of component (A) is 5% by mass or more, based on the total mass of the curable hot-melt silicone composition, and the mass ratio of the content of component (C) relative to the content of component (D) is less than 5.0.