Organopolysiloxane composition
Provided is a hydrosilylation reactive composition that can be used to obtain an organopolysiloxane cured product having high adhesiveness and sufficient mechanical strength, and a method for manufacturing a cured product using this composition. The composition comprises: (A) a compound including at least one monovalent hydrocarbon group with an aliphatic unsaturated bond per molecule; (B) a compound including at least two hydrogen atoms bonded to a silicon atom per molecule; (C) a first hydrosilylation catalyst; and (D) a second hydrosilylation catalyst including platinum, rhodium, ruthenium, or iridium and exhibiting activity at a temperature at least 30° C. higher than the temperature at which component (C) exhibits activity. Also provided is a method for conducting a hydrosilylation reaction at two different temperature levels using this composition.
1. A composition comprising:
(A) a compound including at least one monovalent hydrocarbon group with an aliphatic unsaturated bond per molecule;
(B) a compound including at least two hydrogen atoms bonded to a silicon atom per molecule;
(C) a first hydrosilylation catalyst; and
(D) a second hydrosilylation catalyst including platinum, rhodium, ruthenium, or iridium and exhibiting activity at a temperature at least 30° C. higher than the temperature at which component (C) exhibits activity;
wherein component (B) is an organohydrogenpolysiloxane represented by average composition formula (3) below:
(HR 4 2 SiO 1/2 ) e (R 4 3 SiO 1/2 ) f (HR 4 SiO 2/2 ) g (R 4 2 SiO 2/2 ) h (HSiO 3/2 ) i (R 4 SiO 3/2 ) j (SiO 4/2 ) k (R 5 O 1/2 ) l (3);
where R 4 is a group selected from a monovalent hydrocarbon group having from 1 to 12 carbon atoms and no aliphatic unsaturated bond, a hydroxyl group and an alkoxy group, R 5 is a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, and e, f, g, h, i, j, k and 1 are numbers satisfying the conditions: (e+f+g+h+i+j+k)=1, 0≤1≤0.1, 0.01≤(e+g+i)≤0.2, 0.01≤e≤0.6, 0.01≤g≤0.6, 0≤i≤0.4, 0.01≤(e+f)≤0.8, 0.01≤(g+h)≤0.8, and 0≤(i+j)≤0.6.
2. The composition according to claim 1 , wherein component (D) is a carbene complex or a β-diketonato complex of platinum, rhodium, ruthenium, or iridium.
3. The composition according to claim 1 , wherein components (A) and (B) are both organopolysiloxanes.
4. The composition according to claim 1 , wherein component (A) is an organopolysiloxane represented by average composition formula (1) below:
R 1 a R 2 b SiO (4-a-b)/2 (1);
where R 1 is an alkenyl group having from 2 to 12 carbon atoms, R 2 is a group selected from a monovalent hydrocarbon group having from 1 to 12 carbon atoms and no aliphatic unsaturated bond, a hydroxyl group and an alkoxy group, and a and b are numbers satisfying the conditions: 1≤(a+b)≤3 and 0.001≤k(a/(a+b))≤0.33.
5. The composition according to claim 1 , wherein the molar ratio of the amount of platinum metal in component (C) and in component (D) [(C)/(D)] is from 0.01 to 0.8.
6. The composition according to claim 1 , wherein the composition is adapted for step curing in which heating is performed at a temperature at which component (C) exhibits activity but component (D) does not exhibit activity and followed by heating at a temperature at which component (D) exhibits activity.
7. A method for forming a cured product, the method comprising:
(i) heating the composition according to claim 1 at a temperature at which component (C) exhibits activity but component (D) does not exhibit activity to perform only a first hydrosilylation reaction to obtain a semi-cured product; and
(ii) heating the resulting semi-cured product at a temperature at which component (D) exhibits activity to perform a second hydrosilylation reaction and obtain a cured product.
8. A cured product obtained by the method according to claim 7 .
9. A semi-cured product obtained by heating the composition according to claim 1 at a temperature at which component (C) exhibits activity but component (D) does not exhibit activity to perform only a first hydrosilylation reaction.
10. A method for forming a cured product from a composition comprising:
(A) a compound including at least one monovalent hydrocarbon group with an aliphatic unsaturated bond per molecule;
(B) a compound including at least two hydrogen atoms bonded to a silicon atom per molecule;
(C) a first hydrosilylation catalyst; and
(D) a second hydrosilylation catalyst including platinum, rhodium, ruthenium, or iridium and exhibiting activity at a temperature at least 30° C. higher than the temperature at which component (C) exhibits activity, with the method comprising:
(i) heating a composition at a temperature at which component (C) exhibits activity but component (D) does not exhibit activity to perform only a first hydrosilylation reaction to obtain a semi-cured product; and
(ii) heating the resulting semi-cured product at a temperature at which component (D) exhibits activity to perform a second hydrosilylation reaction and obtain a cured product.
11. A semi-cured product formed from a composition comprising:
(A) a compound including at least one monovalent hydrocarbon group with an aliphatic unsaturated bond per molecule;
(B) a compound including at least two hydrogen atoms bonded to a silicon atom per molecule;
(C) a first hydrosilylation catalyst; and
(D) a second hydrosilylation catalyst including platinum, rhodium, ruthenium, or iridium and exhibiting activity at a temperature at least 30° C. higher than the temperature at which component (C) exhibits activity;
wherein the semi-cured product is obtained by heating the composition at a temperature at which component (C) exhibits activity but component (D) does not exhibit activity to perform only a first hydrosilylation reaction.