Room-temperature-curable polyorganosiloxane composition and electric/electronic apparatus
View Patent ↗There is provided a room-temperature-curable polyorganosiloxane composition having low viscosity and good coatability without any solvent and forming a cured coating film excellent in scratch resistance. The room-temperature-curable polyorganosiloxane composition contains: (A) 100 parts by mass of a mixture of (A1) 10 to 80 parts by mass of a polyorganosiloxane having two or more alkoxy groups bonded to silicon atoms and a prescribed viscosity, and (A2) 90 to 20 parts by mass of a polyorganosiloxane represented by an average composition formula: R 1 a Si(OR 2 ) b O {4−(a+b)}/2 (R 1 and R 2 represent prescribed group respectively, and a and b are prescribed positive numbers), having an Mw of 2,000 to 100,000 and a three-dimensional network structure, and being in a solid state or in a semisolid state at normal temperature; and (B) 0.1 to 15 parts by mass of an organic titanium compound.
1. A room-temperature-curable polyorganosiloxane composition, comprising:
(A) 100 parts by mass of a polyorganosiloxane mixture obtained by mixing
(A1) 10 to 80 parts by mass of a polyorganosiloxane having two or more alkoxy groups bonded to silicon atoms in a molecule and a viscosity at 23° C. of 3 mPa·s to 500 mPa·s, and
(A2) 90 to 20 parts by mass of a polyorganosiloxane represented by an average composition formula (a2), having a weight-average molecular weight (Mw) of 2,000 to 100,000 and a three-dimensional network structure, and being in a solid state or in a semisolid state at normal temperature,
R 1 a Si(OR 2 ) b O {4−(a+b)}/2 (a2)
where R 1 represents an unsubstituted monovalent hydrocarbon group or a monovalent hydrocarbon group in which part of hydrogen atoms is substituted by a halogen atom or a cyano-alkyl group, R 2 represents an alkyl group or an alkoxy-substituted alkyl group being an alkyl group in which part of hydrogen atoms is substituted by an alkoxy group, and a and b are positive numbers satisfying 0.5≤a≤1.5 and 0<b<3, and
(B) 0.1 to 15 parts by mass of an organic titanium compound as a curing catalyst,
wherein the (A1) component comprises a polyorganosiloxane being a partially hydrolyzed condensate of a silane compound represented by a formula (a12),
R 8 e Si(OR 9 ) 4−e (a12)
where R 8 represents an unsubstituted monovalent hydrocarbon group or a monovalent hydrocarbon group in which part of hydrogen atoms is substituted by a halogen atom or a cyano-alkyl group, R 9 represents an alkyl group or an alkoxy-substituted alkyl group being an alkyl group in which part of hydrogen atoms is substituted by an alkoxy group, and e is 0, 1 or 2.
2. The room-temperature-curable polyorganosiloxane composition according to claim 1 , further comprising:
(C) 0.1 to 15 parts by mass of a silane compound represented by a formula (c1),
R 3 c Si(OR 4 ) 4−c (c1)
where R 3 represents an unsubstituted monovalent hydrocarbon group or a monovalent hydrocarbon group in which part of hydrogen atoms is substituted by a halogen atom or a cyano-alkyl group, R 4 represents an alkyl group or an alkoxy-substituted alkyl group being an alkyl group in which part of hydrogen atoms is substituted by an alkoxy group, and c is 0, 1 or 2.
3. The room-temperature-curable polyorganosiloxane composition according to claim 1 ,
wherein the (A1) component comprises a polyorganosiloxane represented by a following general formula (a11),
where R 5 represents an alkyl group or an alkoxy-substituted alkyl group being an alkyl group in which part of hydrogen atoms is substituted by an alkoxy group, R 6 and R 7 are each an unsubstituted monovalent hydrocarbon group or a monovalent hydrocarbon group in which part of hydrogen atoms is substituted by a halogen atom or a cyano-alkyl group, X is a bivalent oxygen (oxy group) or a bivalent hydrocarbon group, d is 0 or 1, and n is an integer so that the viscosity at 23° C. becomes 3 mPa·s to 500 mPa·s.
4. The room-temperature-curable polyorganosiloxane composition according to claim 1 , being a coating composition for an electrode and/or wiring of an electric/electronic apparatus.
5. An electric/electronic apparatus comprising, a coating film made of a cured product of the room-temperature-curable polyorganosiloxane composition according to claim 1 , on a surface of an electrode and/or wiring.