Co-modified organopolysiloxane and curable organopolysiloxane composition including same
Provided is an organopolysiloxane compound serving as a raw material of an organopolysiloxane pressure-sensitive adhesive which has necessary and sufficient pressure-sensitive adhesive strength in a step such as temporary fixing or the like and can be easily peeled off from a substrate in a subsequent step; an organopolysiloxane pressure-sensitive adhesive composition containing the same; and a method for using the same. A chain co-modified organopolysiloxane containing a silicon-bonded functional group (R A ) that contains a specific (meth)acrylic group and at least one aliphatic unsaturated carbon-carbon bond (R Vi ) (but excluding the functional group serving as R A above); a curable organopolysiloxane composition containing the same, further containing a crosslinking agent, a hydrosilylation reaction catalyst, and a photo-radical polymerization initiator, and having both heat curability and photo-curability.
1 . A chain co-modified organopolysiloxane, comprising in a molecule:
a silicon-bonded functional group (R A ) containing an acrylic group or methacrylic group, as expressed by the following General Formula (1-1); and
a silicon-bonded functional group (R Vi ) containing at least one aliphatic unsaturated carbon-carbon bond, but excluding the functional group serving as R A above;
where R 1 mutually independently represents a hydrogen atom, a methyl group, or a phenyl group; R 2 mutually independently represents an alkyl group or an aryl group; Z 1 represents —O(CH 2 ) m — where m is a number within a range of 0 to 3; and Z 2 represents a divalent organic group expressed by —(CH 2 ) n — where n is a number within a range of 2 to 10, bonded to a silicon atom configuring a main chain of a polysiloxane represented by *.
2 . The co-modified organopolysiloxane according to claim 1 , wherein the functional group (R Vi ) is an alkenyl group having 2 to 20 carbon atoms.
3 . The co-modified organopolysiloxane according to claim 1 , wherein the functional group (R Vi ) is a hexenyl group.
4 . The co-modified organopolysiloxane according to claim 1 , wherein two or more of the functional groups (R Vi ) are provided in a molecule.
5 . The co-modified organopolysiloxane according to claim 1 , wherein m is a number within a range of 1 to 3 and n is a number within a range of 3 to 6.
6 . The co-modified organopolysiloxane according to claim 1 , comprising in a molecule the silicon-bonded functional group (R A ) containing an acrylic group or methacrylic group per mol of the silicon-bonded functional group (RV 1 ) containing at least one aliphatic unsaturated carbon-carbon bond but excluding the functional group serving as R A above, in a range at which the average amount thereof is 2.0 to 50.0 mols.
7 . The co-modified organopolysiloxane according to claim 1 , wherein in a molecule, the amount of the silicon-bonded functional group (R A ) containing an acrylic group or methacrylic group is within a range of 0.10 to 10.0 mol % with respect to all functional groups bonded to a silicon atom configuring a polysiloxane molecule.
8 . The co-modified organopolysiloxane according to claim 1 , wherein the main chain of the polysiloxane is a straight chain.
9 . A curable organopolysiloxane composition, comprising:
(A) 100 parts by mass of the co-modified organopolysiloxane according to claims 1 ;
(B) 0.1 to 5 parts by mass of an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule;
(C) a hydrosilylation reaction catalyst in an amount at which the amount of a platinum-based metal in the catalyst is 0.01 to 1000 pm; and
(D) 0.1 to 20 parts by mass of a photo-radical polymerization initiator.
10 . The curable organopolysiloxane composition according to claim 9 , further comprising:
(E) 0.5 to 150 parts by mass of an organopolysiloxane resin containing a siloxane unit (M unit) expressed by R 3 SiO 1/2 where R mutually independently represents a monovalent organic group and a siloxane unit (Q unit) expressed by SiO 4/2, such that the ratio of the M unit to the Q unit is within a range of 0.5 to 2.0.
11 . The curable organopolysiloxane composition according to claim 9 , further comprising:
(F) a polydimethylsiloxane which may optionally have an alkenyl group.
12 . The curable organopolysiloxane composition according to claim 9 , having both heat curability and photo-curability by irradiation with a high energy beam.
13 . The curable organopolysiloxane composition according to claim 9 , wherein when an organopolysiloxane semi-cured product obtained by a heat curing reaction of the curable organopolysiloxane composition is closely adhered to another substrate, the pressure-sensitive adhesive strength to the substrate decreases by 50% or more before and after a photo-curing reaction by irradiation with a high energy beam.
14 . An organopolysiloxane pressure-sensitive adhesive composition, comprising the co-modified organopolysiloxane according to claim 1 .
15 . An organopolysiloxane pressure-sensitive adhesive layer obtained by curing or semi-curing the curable organopolysiloxane composition according to claim 9 .
16 . A method for using the organopolysiloxane pressure-sensitive adhesive composition, comprising:
(I): a step of applying the organopolysiloxane pressure-sensitive adhesive composition according to claim 14 on a substrate;
(II): a step of semi-curing the organopolysiloxane pressure-sensitive adhesive composition applied in step (I) by a heat curing reaction; and
(III): a step of irradiating a semi-cured product obtained in step (II) with a high energy beam to further cure the semi-cured product by a photo-curing reaction;
wherein the pressure-sensitive adhesive strength of the semi-cured product obtained in step (II) to another substrate is reduced by the irradiation with the high energy beam in step (III).
17 . The curable organopolysiloxane composition according to claim 9 , further comprising:
(G) an organic solvent.
18 . The co-modified organopolysiloxane according to claim 1 , wherein the functional groups (R Vi ) are pendant functional groups.
19 . The co-modified organopolysiloxane according to claim 18 , wherein the functional groups (R A ) are pendant functional groups.