Curable silicone composition, cured product of same and method for producing same
Provided is a curable silicone composition and applications thereof. The curable silicone composition has superior hot-melt properties and moldability, where the flexibility, toughness, and stress relief properties of a cured product obtained therefrom are not impaired even if a large amount of functional inorganic filler is blended in. The curable silicone composition comprises an organopolysiloxane resin component with a weight average molecular weight in a range of 2,000 to 15,000 and that contains a siloxane unit represented by SiO 4/2 making up at least 20 mol % or more of the total siloxane units, and one or more functional fillers. The silicone resin component comprises a curing reactive functional group containing a carbon-carbon double bond, and of that curing reactive functional group, 0.05 to 1.50 mol vinyl (CH2═CH—) group is contained per 100 g of the silicone component. The curable silicone composition generally has hot-melt properties as a whole.
1. A curable silicone composition having hot-melt properties, comprising:
(A) an organopolysiloxane resin component having a weight average molecular weight (Mw) in the range of 2,000 to 15,000 as measured by gel permeation chromatography (GPC) using toluene as a solvent, where 20 mol % or more of the total siloxane units of the organopolysiloxane resin component is siloxane units represented by SiO 4/2 ; and
D) one or more functional fillers;
wherein the organopolysiloxane resin component comprises a curing reactive functional group containing a carbon-carbon double bond and, of that curing reactive functional group, 0.05 to 1.50 mol vinyl (CH2═CH—) group is contained per 100 g of silicone component in the composition.
2. The curable silicone composition according to claim 1 , comprising:
(A) 100 mass parts of organopolysiloxane resin component containing the following component (A1) and component (A2) in a mass ratio of 0:100 to 75:25, and the weight average molecular weight (Mw) of component (A1) and component (A2) is in the range of 2,000 to 15,000 as measured by gel permeation chromatography (GPC) using toluene as a solvent and polystyrene standards;
(A1) an organopolysiloxane resin having no hot-melt properties as a whole molecule, having a curing reactive functional group containing a carbon-carbon double bond in the molecule, and where 20 mol % or more of the total siloxane units of the organopolysiloxane resin is siloxane units represented by SiO 4/2 ;
(A2) an organopolysiloxane resin having no hot-melt properties as a whole molecule, having no curing reactive functional groups containing a carbon-carbon double bond in the molecule, and where 20 mol % or more of the total siloxane units of the organopolysiloxane resin is siloxane units represented by SiO 4/2 ;
(B) 10 to 100 mass parts of a straight-or branched-chain organopolysiloxane, liquid at 25° C., and having at least two curing reactive functional groups containing a carbon-carbon double bond in the molecule;
(C) one or more curing agents selected from (c1) or (c2) below, in an amount necessary to cure the composition:
(c1) an organic peroxide,
(c2) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in the molecule and a hydrosilylation reaction catalyst; and
(D) functional filler;
wherein the amount of component (D) is in the range of 10 to 2000 mass parts relative to 100 mass parts of the sum of component (A) and component (B).
3. The curable silicone composition according to claim 2 , wherein:
component (A1) is an organopolysiloxane resin (A1-1) not having hot-melt properties and represented by the following average unit formula:
(R 1 3 SiO 1/2 ) a (R 1 2 SiO 2/2 ) b (R 1 SiO 3/2 ) c (SiO 4/2 ) d (R 2 O 1/2)e
where each R 1 is an independent monovalent hydrocarbon group having 1 to 10 carbon atoms, however, 1 to 12 mol % of all R 1 in a molecule is an alkenyl group; each R 2 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; and a, b, c, d, and e are numbers satisfying the following: 0.10≤a≤0.60, 0≤b≤0.70, 0≤c≤0.80, 0≤d≤0.65, 0≤e≤0.05, (c+d)>0.20, and (a+b+c+d)=1;
component (A2) is a non-hot-meltable organopolysiloxane resin (A2-1) represented by the following average unit formula:
(R 3 3 SiO 1/2 ) f (R 3 2 SiO 2/2 ) g (R 3 SiO 3/2 ) h (SiO 4/2 ) i (R 2 O 1/2)j
where each R 3 is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms and not containing a carbon-carbon double bond; R 2 is a hydrogen atom with an alkyl group having 1 to 10 carbon atoms; and f, g, h, i, and j are numbers satisfying the following: 0.35≤f≤0.55, 0≤g≤0.20, 0≤h≤0.20, 0.45≤i≤0.65, 0≤j≤0.05, and (f+g+h+i)=1;
component (B) is a straight-chain diorganopolysiloxane (B1) represented by the following structural formula:
R 4 3 SiO (SiR 4 2 O) k SiR 4 3
where each R 4 is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, except that at least two of the R 4 in one molecule are alkenyl groups, and k is a number from 20 to 5,000.
4. The curable silicone composition according to claim 2 , wherein component (A1) and component (A2) are spherical organopolysiloxane resin microparticles having an average primary particle diameter of 1 to 20 μm.
5. The curable silicone composition according to claim 2 , wherein for component (C), the content of the organohydrogenpolysiloxane is an amount where the molar ratio of the silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane resin relative to the curing reactive functional groups containing carbon-carbon double bonds in component (A) and component (B) is in the range of 0.5 to 20.
6. The curable silicone composition according to claim 2 , wherein component (D) is a functional filler containing one or more types selected from the group consisting of a reinforcing filler, a white pigment, a thermally conductive filler, an electrically conductive filler, and an organic filler.
7. The curable silicone composition according to claim 1 , in a granular, pellet, or sheet form.
8. A substantially flat, 10 to 1000 μm thick, curable silicone composition sheet formed from the curable silicone composition according to claim 1 .
9. A film-like adhesive, comprising the curable silicone composition sheet according to claim 8 .
10. A peelable laminate, comprising:
the curable silicone composition sheet according to claim 8 , and
a sheet-like substrate with a release surface facing the curable silicone composition sheet on one or both surfaces of the curable silicone composition sheet.
11. A cured product obtained by curing the curable silicone composition according to claim 1 .
12. A member for a semiconductor device, the member comprising the cured product of claim 11 .
13. A semiconductor device, comprising the cured product according to claim 11 .
14. A method for manufacturing the curable silicone composition according to claim 1 , wherein each component that makes up the curable silicone composition is granulated by mixing under temperature conditions not exceeding 50° C.
15. A method of molding a cured product, comprising the following steps:
(I) heating and melting the curable silicone composition according to claim 1 at a temperature of 100° C. or higher;
(II) injecting the curable silicone composition in a liquid state obtained in step (I) into a mold or distributing the curable silicone composition obtained in step (I) to a mold by clamping; and
(III) curing the curable silicone composition injected or distributed in step (II).
16. A method for manufacturing the curable silicone composition sheet according to claim 8 , comprising the following steps:
1) mixing raw material components of the curable silicone composition at a temperature of 50° C. or higher;
2) kneading a mixture obtained in step 1) while heating and melting;
3) laminating a heated and melted mixture obtained in step 2) between films provided with at least one release surface; and
4) extending a laminate body obtained in step 3) between rollers to mold a curable silicone sheet having a specific film thickness.