US 12,460,114 B2
Hydrosilylation reaction cured silicone pressure sensitive adhesive, composition and method for its preparation, and use in a flexible display device
Qing Cao, Shanghai (CN); Yan Zhou, Shanghai (CN); and Chao Ma, Shanghai (CN)
Assigned to Dow Silicone Corporation, Midland, MI (US)
Appl. No. 18/262,024
Filed by Dow Silicones Corporation, Midland, MI (US)
PCT Filed Apr. 27, 2021, PCT No. PCT/CN2021/090314
§ 371(c)(1), (2) Date Jul. 19, 2023,
PCT Pub. No. WO2022/226797, PCT Pub. Date Nov. 3, 2022.
Prior Publication US 2024/0294814 A1, Sep. 5, 2024
Int. Cl. C09J 5/00 (2006.01); C09J 183/04 (2006.01)
CPC C09J 183/04 (2013.01) [C09J 5/00 (2013.01); C09J 2301/302 (2020.08); C09J 2483/00 (2013.01); Y10T 428/28 (2015.01); Y10T 428/2852 (2015.01)] 16 Claims
 
1. A hydrosilylation reaction curable composition for forming a silicone pressure sensitive adhesive, where the composition comprises:
35.15 weight % to 43.63weight %, based on combined weights of starting materials (A) to (F), of (A) a polydiorganosiloxane gum component comprising
28.03 weight % to 43.50 weight %, based on combined weights of the starting materials (A) to (F), of (A-1) an aliphatically unsaturated polydiorganosiloxane gum of unit formula (RM2RUSiO1/2)2(RM2SiO2/2)a, where each RM is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms that is free of aliphatic unsaturation; each RU is an independently selected monovalent aliphatically unsaturated hydrocarbon group of 2 to 30 carbon atoms; and subscript a has a value sufficient to give the polydiorganosiloxane gum a plasticity of 20 mil (0.51 mm) to 80 mil (2.03 mm), where plasticity is measured based on ASTM D926 by applying 1 kg load to a spherical sample of 4.2 g in weight for 3 minutes at 25° C. and the results are measured in thousandths of an inch (mil) and the procedure is based on ASTM D926;
0 to 0.26 weight % of (A-2) a hydroxyl-terminated polydiorganosiloxane gum of unit formula ((HO)RM2SiO1/2)2(RM2SiO2/2)a′, where each RM is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms that is free of aliphatic unsaturation; each subscript a′ has a value sufficient to give the polydiorganosiloxane gum a plasticity of 20 mil (0.51 mm) to 80 mil (2.03 mm); and
0 to 7 weight % of (A-3) a non-functional polydiorganosiloxane gum of unit formula (RM3SiO1/2)2(RM2SiO2/2)a″, where each RM is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms that is free of aliphatic unsaturation, and subscript a″ has a value sufficient to give the non-functional polydiorganosiloxane gum a plasticity of 20 mil (0.51 mm) to 80 mil (2.03 mm);
52.69 weight % to 63.26 weight % of (B) a polyorganosilicate resin component comprising
52.39 weight % to 63.11 weight %, based on combined weights of the starting materials (A) to (F), of (B-1) a capped resin of unit formula: (RM3SiO1/2)z(SiO4/2)oZp, where each RM is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms that is free of aliphatic unsaturation, Z is a hydrolyzable group, subscript p is 0 to a value sufficient to give the capped resin a hydrolyzable group content up to 2%, subscripts z and o have values such that z>4, o>1, and a quantity (z+o) has a value sufficient to provide the capped resin with a number average molecular weight of 500 g/mol to 5,000 g/mol; and
0 to 0.37 weight %, based on combined weights of the starting materials (A) to (F), of (B-2) an uncapped resin of unit formula (RM3SiO1/2)z′(SiO4/2)o′Zp′, where each RM is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms that is free of aliphatic unsaturation, Z is a hydrolyzable group, subscript p′ has a value sufficient to give the uncapped resin a hydrolyzable group content of >3% to 10%, subscripts z′ and o′ have values such that z′>4, o′>1, and a quantity (z′+o′) has a value sufficient to provide the uncapped resin with a number average molecular weight of 500 g/mol to 5,000 g/mol;
where (A) the polydiorganosiloxane gum component and (B) the polyorganosilicate resin component are present in a weight ratio of (B):(A) (Resin: Gum Ratio)≤1.8:1;
0.01 weight % to 5 weight %, based on combined weights of the starting materials (A) to (F), of (C) a hydrosilylation reaction catalyst;
(D) a polyorganohydrogensiloxane of unit formula: (RM2SiO2/2)e(HRMSiO2/2)f(RM2HSiO1/2)g(RM3SiO1/2)h; where each RM is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms that is free of aliphatic unsaturation, subscript e>0, subscript f≥0, a quantity (e+f) is 4 to 500, subscript g is 0, 1, or 2, subscript h is 0, 1, or 2, a quantity (g+h)=2, and a quantity (f+g)≥3; where (D) the polyorganohydrogensiloxane is present in an amount sufficient to provide a mole ratio of silicon bonded hydrogen atoms to aliphatically unsaturated hydrocarbon groups of (A) the polydiorganosiloxane gum component, {(D):(A) ratio}, of 31.37:1 to 59.04:1;
0.05 weight % to 1.00 weight %, based on combined weights of the starting materials (A) to (F), of (E) a trialkyl borate;
0 weight % to 5 weight %, based on combined weights of the starting materials (A) to (F), of (F) a hydrosilylation reaction inhibitor;
greater than 0 weight % to 90 weight %, based on combined weights of all starting materials in the composition, of (G) a solvent; and
0 to 5 weight %, based on combined weights of the starting materials (A) to (F), of (H) an anchorage additive.