Curable hot-melt silicone composition, cured product thereof, and laminate including curable hot-melt silicone composition or cured product thereof
Provided is a hot-melt curable silicone composition that forms a cured product that can be cured at a temperature of 100° C. or lower, has excellent storage stability, is relatively hard from curing, and has low surface tack, and a sheet or film formed from the same. The curable silicone composition comprises: (A) a solid organopolysiloxane resin that contains at a mass ratio of 0:100 to 90:10 (Al) an organopolysiloxane resin having a curing reactive functional group and containing 20 mol % or more of a Q unit (i.e., a SiO 4/2 unit), and (A2) an organopolysiloxane resin not having a curing reactive functional group and containing 20 mol % or more of a Q unit; (B) 10 to 100 parts by mass of a straight-chain or branched organopolysiloxane having a curing reactive functional group and is liquid or has plasticity; (C) an organohydrogenpolysiloxane; and (D) a photoactivated hydrosilylation reaction catalyst.
1 . A curable silicone composition having hot-melt properties as a whole composition, comprising:
(A) 100 mass parts of an organopolysiloxane resin containing the following component (A1) and component (A2) at a mass ratio of 20:80 to 90:10;
(A1) an organopolysiloxane resin that is solid at 25° C., having a curing reactive functional group containing a carbon-carbon double bond in a molecule, containing a siloxane unit expressed by SiO 4/2 making up at least 20 mol % of all siloxane units, and does not independently have hot-melt properties, and
(A2) an organopolysiloxane resin that is solid at 25° C., not having a curing reactive functional group containing a carbon-carbon double bond in a molecule, containing a siloxane unit expressed by SiO 4/2 making up at least 20 mol % of all siloxane units, and does not independently have hot-melt properties;
(B) 10 to 100 mass parts of a straight-chain or branched organopolysiloxane that is liquid or has plasticity at 25° C., having a curing reactive functional group containing at least two carbon-carbon double bonds in a molecule;
(C) an organohydrogenpolysiloxane resin having at least two silicon-bonded hydrogen atoms in a molecule, present in an amount where the number of hydrogen atoms bonded to a silicon atom per one alkenyl group bonded to a silicon atom included in the entire composition is 0.5 to 20.0; and
(D) a hydrosilylation reaction catalyst that does not exhibit activity without irradiating with a high energy beam, but exhibits activity in the composition when a high energy beam is irradiated at an amount sufficient for curing the composition;
wherein component (A) has a mass loss ratio of 2.0 mass % or less when exposed to 200° C. for one hour; and
wherein component (C) is expressed by the following average compositional formula (2):
(HR 6 2 SiO 1/2 ) e (R 6 2 SiO 2/2 ) f (SiO 4/2 ) g (2)
where R 6 independently represents an unsubstituted or substituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond with 1 to 12 carbon atoms, and e, f, and g represent numbers that satisfy conditions of 0.01≤e≤0.6, 0≤f≤0.9, 0.2≤g≤0.9, and e+f+g=1; or
wherein component (C) is expressed by the following average compositional formula (3):
(HR 7 2 SiO 1/2 ) h (R7 2 SiO 2/2 ) i (R 8 SiO 3/2 ) i (3)
where R 7 and R 8 each independently represent an unsubstituted or substituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond with 1 to 12 carbon atoms, at least 10 mol % of all Ros represent aryl groups, and h, 1, and j represent numbers that satisfy conditions of 0.01≤h≤0.6, 0≤i≤0.9, 0.2≤j≤0.9, and h+i+j=1.
2 . The curable silicone composition according to claim 1 , further comprising:
(E) 1 to 5000 ppm of a curing retarder for a hydrosilylation reaction having a boiling point of 200° C. or higher at atmospheric pressure, based on the total mass of the composition.
3 . The curable silicone composition according to claim 1 , wherein component (A1) is (A1-1) an organopolysiloxane resin that does not have hot-melt properties alone, expressed 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 independently represents a monovalent hydrocarbon group with 1 to 10 carbon atoms, but 1 to 12 mol % of all R 1 s in a molecule represents an alkenyl group; each R 2 represents a hydrogen atom or an alkyl group with 1 to 10 carbon atoms; and “a”, “b”, “c”, “d”, and “e” represent numbers that satisfy 0.10≤a≤0.60, 0≤b≤0.70, 0≤c≤0.80,0≤d≤0.65,0≤e≤0.05, but (c+d)>0.20 and (a+b+c+d)=1;
component (A2) is (A2-1) an organopolysiloxane resin that does not have hot-melt properties alone, expressed 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 independently represents a monovalent hydrocarbon group with 1 to 10 carbon atoms and does not contain a carbon-carbon double bond; R 2 represents a hydrogen atom with an alkyl group with 1 to 10 carbon atoms; and “f”, “g”, “h”, “I”, and “j” represents numbers that satisfy 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; and
component (B) is (B1) a straight-chain diorganopolysiloxane expressed by the following structural formula:
R 4 3 SiO(SiR 4 2 O) k SiR 4 3
where each R 4 independently represents a monovalent hydrocarbon group with 1 to 10 carbon atoms, but at least two of the R 4 s in one molecule represents an alkenyl group, and k represents a number from 20 to 5,000.
4 . A curable silicone composition sheet or film formed from the curable silicone composition according to claim 1 , which is melt-kneaded under vacuum within a temperature range of 50 to 150° C. and then molded into a sheet or film.
5 . The curable silicone composition sheet or film according to claim 4 , wherein the thickness is between 10 and 1000 μm.
6 . A releasable laminate body, comprising:
the curable silicone composition sheet or film according to claim 4 ; and
a sheet or film-like base material adhered to one or two surfaces of the curable silicone composition sheet or film, and having a release surface facing the curable silicone composition sheet or film; wherein
the curable silicone composition sheet or film can be released from the sheet or film-like base material having the release surface.
7 . A laminate body, comprising:
a base material serving as an electronic component or a precursor thereof; and
a curable silicone composition layer formed with at least one surface of the curable silicone composition sheet or film according to claim 4 firmly adhered to a portion or all of a front surface of the base material; wherein
the curable silicone composition is in an uncured state.
8 . A cured product obtained by irradiating the curable silicone composition according to claim 1 with a high energy beam and then curing.
9 . A method of manufacturing the laminate body according to claim 7 , comprising a step of firmly adhering at least one surface of an uncured curable silicone composition sheet or film to a portion or all of a base material serving as an electronic component or a precursor thereof, by one or more means selected from vacuum laminators, vacuum presses, and compression molding.
10 . A method of manufacturing a laminate body including a cured silicone composition layer, comprising a step of irradiating the laminate body according to claim 7 with a high energy beam and then heating to cure the uncured curable silicone composition.
11 . A method of manufacturing a laminate body including a cured silicone composition, comprising a step of irradiating the curable silicone composition sheet or film according to claim 4 with a high energy beam, then adhering at least one surface of the uncured curable silicone composition sheet or film to a portion or all of a base material serving as an electronic component or precursor thereof by one or more means selected from vacuum laminators, vacuum presses, and compression molding, and forming a laminate body while curing the silicone composition film or sheet by heating.
12 . The curable silicone composition according to claim 3 , further comprising:
(E) 1 to 5000 ppm of a curing retarder for a hydrosilylation reaction having a boiling point of 200° C. or higher at atmospheric pressure, based on the total mass of the composition.
13 . The curable silicone composition according to claim 1 , wherein component (A1) is (A1-1) an organopolysiloxane resin that does not have hot-melt properties alone, expressed 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 independently represents a monovalent hydrocarbon group with 1 to 10 carbon atoms, but 1 to 12 mol % of all R's in a molecule represents an alkenyl group; each R 2 represents a hydrogen atom or an alkyl group with 1 to 10 carbon atoms; and “a”, “b”, “c”, “d”, and “e” represent numbers that satisfy 0.10≤a≤0.60, 0≤b≤0.70,0≤c≤0.80,0≤d≤0.65,0≤e≤ 0.05, but (c+d)≤0.20 and (a+b+c+d)=1.
14 . The curable silicone composition according to claim 1 , wherein component (A2) is (A2-1) an organopolysiloxane resin that does not have hot-melt properties alone, expressed 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 independently represents a monovalent hydrocarbon group with 1 to 10 carbon atoms and does not contain a carbon-carbon double bond; R 2 represents a hydrogen atom with an alkyl group with 1 to 10 carbon atoms; and “f”, “g”, “h”, “I”, and “j” represents numbers that satisfy 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.
15 . The curable silicone composition according to claim 1 , wherein component (B) is (B1) a straight-chain diorganopolysiloxane expressed by the following structural formula:
R 4 3 SiO(SiR 4 2 O) k SiR 4 3
where each R 4 independently represents a monovalent hydrocarbon group with 1 to 10 carbon atoms, but at least two of the Ras in one molecule represents an alkenyl group, and k represents a number from 20 to 5,000.
16 . The curable silicone composition according to claim 1 , wherein the composition has a softening point of between 5° and 200° C. and a melt viscosity of less than 1000 Pa·s at 150° C.
17 . The curable silicone composition according to claim 1 , wherein component (C) is expressed by the average compositional formula (2).
18 . The curable silicone composition according to claim 1 , wherein component (C) is expressed by the average compositional formula (3).