Composition for preparing a release coating

Patent metadata

Field	Value
Publication number	US-12497549-B2
Application number	US-202017780546-A
Country	US
Kind code	B2
Filing date	Dec 2, 2020
Priority date	Dec 2, 2019
Publication date	Dec 16, 2025
Grant date	Dec 16, 2025

Abstract

A composition for forming a release coating is disclosed. The composition comprises (A) an organopolysiloxane comprising the reaction product of: (i) a silicone resin having a particular formula; (ii) a cyclic siloxane; and (iii) (iii) at least one of (A)(iii)(a) a branched organopolysiloxane having a particular formula or (A)(iii)(b) a terminating agent; in the presence of a polymerization catalyst. The composition further comprises (B) an organopolysiloxane including an average of at least two silicon-bonded ethylenically unsaturated groups per molecule.

First claim

What is claimed is:

1 . A method of preparing a composition for forming a release coating, said method comprising:
preparing (A) an organopolysiloxane by reacting: (i) a silicone resin having the formula (R 1 y R 2 3-y SiO 1/2 ) x (SiO 4/2 ), wherein each R 1 is an independently selected hydrocarbyl group having from 1 to 32 carbon atoms; each R 2 is independently selected from R 1 , an alkoxy group, and a hydroxyl group; y is an integer from 0 to 3 and is independently selected in each siloxy unit indicated by subscript x; and subscript x is from 0.05 to 0.99; (ii) a cyclic siloxane having the formula (R 1 2 SiO 2/2 ) n , where R 1 is defined above and n is an integer from 3 to 15; and (iii) at least one of (A)(iii)(a) a branched organopolysiloxane having the formula (R 3 y′ R 1 3-y′ SiO 1/2 ) x′ (SiO 4/2 ), where each R 3 is independently an ethylenically unsaturated group, subscript y′ is 1 or 2; each R 1 is independently selected and defined above, and x′ is from 1 to 4; or (A)(iii)(b) a terminating agent; in the presence of a polymerization catalyst; and combining component (A) with (B) an organopolysiloxane including an average of at least two silicon-bonded ethylenically unsaturated groups per molecule.

2 . The method of claim 1 , wherein:
(i) each R 1 is an independently selected alkyl group or alkenyl group, with the proviso that at least one R 1 is an alkenyl group; (ii) subscript y is 3; (iii) subscript x is from 0.05 to 0.9; (iv) subscript n is 4 or 5; or (v) any combination of (i) to (iv).

3 . The method of claim 1 , wherein the polymerization catalyst comprises a phosphazene base catalyst.

4 . The method of claim 1 , wherein subscript x is from 0.05 to 0.80.

5 . The method of claim 1 , wherein the (B) organopolysiloxane:
(i) is a branched organopolysiloxane including silicon-bonded ethylenically unsaturated groups in at least one M siloxy unit; or (ii) is a linear organopolysiloxane having a degree of polymerization of from 5 to 1,000.

6 . The method of claim 1 , further comprising combining with components (A) and (B) a hydrosilylation-reaction inhibitor.

7 . The method of claim 1 , further comprising combining with components (A) and (B):
(C) an organosilicon compound including an average of at least two silicon-bonded hydrogen atoms per molecule; and (D) a hydrosilylation catalyst.

8 . The method of claim 7 , wherein:
(i) the (C) organosilicon compound comprises an organohydrogensiloxane including an average of at least two pendent silicon-bonded hydrogen atoms per molecule; (ii) the molar ratio of SiH to silicon-bonded ethylenically unsaturated groups is from 1:1 to 5:1; or (iii) both (i) and (ii).

9 . The method of claim 1 , wherein the composition comprises the (A) organopolysiloxane in an amount of from 0.5 to 10 weight percent based on the total weight of the composition.

10 . The method of claim 1 , wherein the composition comprises the (B) organopolysiloxane in an amount of from 80 to 99.5 weight percent based on the total weight of the composition.

11 . A method of forming a coated substrate, said method comprising:
preparing (A) an organopolysiloxane by reacting: (i) a silicone resin having the formula (R 1 y R 2 3-y SiO 1/2 ) x (SiO 4/2 ), wherein each R 1 is an independently selected hydrocarbyl group having from 1 to 32 carbon atoms; each R 2 is independently selected from R 1 , an alkoxy group, and a hydroxyl group; y is an integer from 0 to 3 and is independently selected in each siloxy unit indicated by subscript x; and subscript x is from 0.05 to 0.99; ii) a cyclic siloxane having the formula (R 1 2 SiO 2/2 ) n , where R 1 is defined above and n is an integer from 3 to 15; and (iii) at least one of (A)(iii)(a) a branched organopolysiloxane having the formula (R 3 y ′R 1 3-y′ SiO 1/2 ) x′ (SiO 4/2 ), where each R 3 is independently an ethylenically unsaturated group, subscript y′ is 1 or 2; each R 1 is independently selected and defined above, and x′ is from 1 to 4; or (A)(iii)(b) a terminating agent; in the presence of a polymerization catalyst; and
combining component (A) with (B) an organopolysiloxane including an average of at least two silicon-bonded ethylenically unsaturated groups per molecule, (C) an organosilicon compound including an average of at least two silicon-bonded hydrogen atoms per molecule; and (D) a hydrosilylation catalyst to give a composition;
applying the composition on a substrate; and
curing the composition to give a release coating on the substrate, thereby forming the coated substrate.

12 . The method of claim 11 , wherein the substrate comprises cellulose and/or a polymer.

13 . The method of claim 1 , wherein component (A)(iii) is the (A)(iii)(a) branched organopolysiloxane.

14 . The method of claim 1 , wherein component (A)(iii) is the (A)(iii)(b) terminating agent.

Assignees

• Dow Silicones Corp

Inventors

• Chevalier Pierre
• Niu Zhenbin
• Ng Sze-Sze
• Dehlin Lori
• Dujardin Deana
• Knott Alex
• Rich David
• Bekemeier Thomas
• Mitchell Timothy P
• Ahn Dongchan

Classifications

• C08G77/06

  Preparatory processes · CPC title

• C09J2483/005

  in the release coating · CPC title

• C08G77/70

  Siloxanes defined by use of the MDTQ nomenclature · CPC title

• C08G77/20

  containing silicon bound to unsaturated aliphatic groups · CPC title

• C08G77/08

  characterised by the catalysts used · CPC title