Process for producing (meth)acrylic polymer terminated by crosslinkable silyl group
View Patent ↗A method for producing a (meth)acrylic polymer having crosslinkable silyl groups at the termini, comprising a step of adding a hydrosilane compound having a crosslinkable silyl group to an alkenyl-terminated (meth)acrylic polymer (A), which is prepared by atom transfer radical polymerization, in the presence of a platinum hydrosilylation catalyst. The amount of the platinum hydrosilylation catalyst is 0.1 to 10 mg on a platinum metal basis per kilogram of the alkenyl-terminated (meth)acrylic polymer (A). An object of the invention is to provide a method for producing a (meth)acrylic polymer having terminal crosslinkable silyl.
1. A method for producing a (meth)acrylic polymer having crosslinkable silyl groups at the termini, comprising the steps of:
(i) preparing (A) an alkenyl-terminated (meth)acrylic polymer containing halogen groups by atom transfer radical polymerization;
(ii) heating the alkenyl-terminated (meth)acrylic polymer to a temperature in the range of 170° C. to 250° C. without an adsorbent to remove said halogen groups from the alkenyl-terminated (meth)acrylic polymer;
(iii) separating insoluble components contained in the dehalogenated alkenyl-terminated (meth)acrylic polymer; and
(iv) mixing the alkenyl-terminated (meth)acrylic polymer (A) obtained by steps (i) to (iii), having 10 mg or less of a transition metal per kilogram of the polymer (A) and 500 mg or less of a halogen per kilogram of the polymer (A), a hydrosilane compound having a crosslinkable silyl group (B), and a platinum catalyst (C) to carry out hydrosilylation reaction.
2. The method according to claim 1 , wherein the polymer (A) contains 3 mg or less of the transition metal per kilogram of the polymer (A).
3. The method according to claim 1 , wherein the polymer (A) contains 300 mg or less of the halogen per kilogram of the polymer (A).
4. The method according to claim 1 , wherein the amount of the platinum catalyst (C) used is 0.1 mg to 30 mg on a platinum metal basis per kilogram of the polymer (A).
5. The method according to claim 1 , wherein the amount of the platinum catalyst (C) used is 0.5 mg to 10 mg on a platinum metal basis per kilogram of the polymer (A).
6. The method according to claim 1 , wherein the hydrosilylation is carried out in the presence of a hydrolyzable ester compound and/or an alkyl alcohol.
7. The method according to claim 6 , wherein the hydrolyzable ester compound is trialkyl orthoformate.
8. The method according to claim 1 , wherein the hydrosilylation is carried out in an inert gas atmosphere.
9. The method according to claim 8 , wherein the inert gas is nitrogen gas.
10. The method according to claim 1 , wherein the hydrosilylation is carried out at a temperature in the range of 50° C. to 150° C.
11. The method according to claim 1 , wherein the hydrosilylation is carried out at a temperature in the range of 70° C. to 120° C.
12. The method according to claim 1 , wherein the hydrosilane compound (B) having a crosslinkable silyl group is added in portions.
13. The method according to claim 1 , wherein the hydrosilane compound (B) having a crosslinkable silyl group is methyldimethoxysilane.
14. The method according to claim 1 , wherein the platinum catalyst (C) is a platinum(0)-1,1,3,3-tetramethyl-1,3-divinyldisiloxane complex.
15. The method according to claim 1 , wherein the polymer (A) is prepared by the following steps (1) to (3):
(1) polymerizing a (meth)acrylic monomer in the presence of a transition metal complex functioning as a catalyst and one of an organohalide compound and a sulfonyl halide compound functioning as an initiator, thereby producing a halogen-terminated (meth)acrylic polymer;
(2) reacting the halogen group with a compound having a plurality of alkenyl groups in the molecule; and
(3) carrying out dehalogenation reaction by heating.
16. The method according to claim 1 , wherein the halogen is selected from the group consisting of chlorine, bromine, and iodine.
17. The method according to claim 1 , wherein the (meth)acrylic polymer is a (meth)acrylic ester polymer.
18. The method according to claim 1 , wherein the (meth)acrylic polymer is an acrylic ester polymer.
19. The method according to claim 15 , wherein the compound having a plurality of alkenyl groups in the molecule is a nonconjugated diene compound.
20. The method according to claim 15 , wherein the compound having a plurality of alkenyl groups in the molecule is an alkenyl-containing aliphatic hydrocarbon compound.
21. The method according to claim 15 , wherein the compound having a plurality of alkenyl groups in the molecule is 1,7-octadiene.
22. The method according to claim 1 , wherein the polymer (A) is obtained by processing 100 kg or more of a polymer at a time.