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EP-4735529-A1 - CURABLE SILICONE COMPOSITION AND CURED PRODUCT THEREOF

EP4735529A1EP 4735529 A1EP4735529 A1EP 4735529A1EP-4735529-A1

Abstract

A curable silicone composition is provided. The curable silicone composition comprises: (A) an organopolysiloxane comprising an average of two or more alkenyl groups; (B) a crosslinker with an average of three or more mercapto groups; (C) an epoxy-functional silicone resin having monovalent aromatic hydrocarbon groups; (D) an epoxy-functional silicone; (E) an iodonium salt type cationic photoinitiator; and (F) a cationic photoinitiator other than component (E). According to the present disclosure, a Silicone-Epoxy hybrid material having benefits of both silicones and organic epoxies, having excellent reliability performance and adhesiveness suitable for applications in the electronic display market may be provided.

Inventors

  • HUR, Moon Young
  • KWON, Minhee

Assignees

  • Dow Silicones Corporation

Dates

Publication Date
20260506
Application Date
20240625

Claims (8)

  1. 1 . A curable silicone composition comprising: (A) an organopolysiloxane comprising an average of two or more alkenyl groups represented by the following general formula: wherein R 1 and R 8 each independently represent a C2-30 alkenyl group; R 2 to R 7 each independently represent a C1 -30 monovalent aliphatic hydrocarbon group, or a C6-30 monovalent aromatic hydrocarbon group; and "n" is an integer of from 0 to 100; (B) a crosslinker with an average of three or more mercapto groups represented by the following general formula: wherein R 9 each independently represents a C1-30 monovalent aliphatic hydrocarbon group, or a C6-30 monovalent aromatic hydrocarbon group; R 10 each independently represents a C1-30 divalent aliphatic hydrocarbon group, or a C6-30 divalent aromatic hydrocarbon group; and R 11 each independently represents a mercapto group or a C1-6 alkyl group, provided that at least three of the R 11, s are mercapto groups; (C) an epoxy-functional silicone resin represented by the following average unit formula: (R 12 3 SiOi/ 2 ) a (R 12 2 SiO 2/2 ) b (R 12 SiO 3 / 2 ) c (SiO 4 / 2 ) d wherein R 12 each independently represents a C1 -6 monovalent aliphatic hydrocarbon group, a C6-10 monovalent aromatic hydrocarbon group, or a monovalent epoxy-substituted organic group, provided that at least about 15 mol% of the total R 12 are C6-10 monovalent aromatic hydrocarbon groups; and "a", "b", "c" and "d" are numbers that satisfy the following conditions: 0<a<0.4, 0<b<0.5, 0<c<1 , 0<d<0.4, 0.1 <b/c<0.6, and a+b+c+d=1; and about 2 to about 30 mol% of the total siloxane units have the monovalent epoxy-substituted organic groups; (D) an epoxy-functional silicone represented by the following general formula: X 1 -R 13 2 SiO(SiR 13 2 O)mSiR 13 2 -X 1 wherein R 13 each independently represents a C1 -6 monovalent aliphatic hydrocarbon group, or a C6-10 monovalent aromatic hydrocarbon group; X 1 each independently represents a monovalent epoxy-substituted organic group, or an epoxyfunctional siloxy group represented by the following general formula: X 2 -R 14 2 SiO(SiR 14 2 O) x SiR 14 2 -R 15 - wherein R 14 each independently represents a C1 -6 monovalent aliphatic hydrocarbon group; R 15 represents a C2-6 alkylene group; X 2 represents a monovalent epoxy-substituted organic group; "x" represents a number of from 0 to 5; and "m" represents a number of from 0 to 100; (E) an iodonium salt type cationic photoinitiator; and (F) a cationic photoinitiator other than component (E).
  2. 2. The curable silicone composition according to claim 1 , wherein in component (A), R 1 and R 8 each independently represent a vinyl group; R 2 , R 3 , R 6 , and R 7 each independently represent a C1 -6 alkyl group; R 4 and R 5 each independently represent a C6-12 aryl group; and "n" is an integer of from 0 to 40.
  3. 3. The curable silicone composition according to claim 1 , wherein in component (B), R 9 each independently represents a C1 -6 alkyl group; R 10 each independently represents a C1 - 6 alkylene group; and R 11 each independently represents a mercapto group.
  4. 4. The curable silicone composition according to claim 1 , wherein the monovalent epoxy-substituted organic groups in component (C) are groups selected from glycidoxyalkyl groups, 3,4-epoxycyclohexylalkyl groups, and epoxyalkyl groups.
  5. 5. The curable silicone composition according to claim 1 , wherein the monovalent epoxy-substituted organic groups in component (D) are groups selected from glycidoxyalkyl groups, 3,4-epoxycyclohexylalkyl groups, and epoxyalkyl groups.
  6. 6. The curable silicone composition according to claim 1 , wherein component (E) is an iodonium salt type cationic photoinitiator having a structure represented by the following general formula: R 16 2 l + X _ wherein, R 16 each independently represents a C1 -6 alkyl group, C6-24 aryl group, or a substituted C6-24 aryl group; and X- represents a non-nucleophilic non-basic anion.
  7. 7. The curable silicone composition according to any one of claims 1 to 6, further comprising: (G) an adhesion promoter, in an amount of from about 0.01 to about 5 mass% of the total mass of components (A) to (F).
  8. 8. A cured product obtained by curing the curable silicone composition according to any one of claims 1 to 8.

Description

CURABLE SILICONE COMPOSITION AND CURED PRODUCT THEREOF Cross-Reference to Related Applications [0001] The application claims priority to and all advantages of U.S. Provisional Patent Application No. 63/524,263 filed on 30 June 2023, the content of which is incorporated herein by reference. Technical Field [0002] The present invention relates to a curable silicone composition and a cured product thereof. Background Art [0003] Silicone-based materials are known to display high flexibility, processability, and thermal reliability but have low surface hardness and adhesion. Organic epoxy materials are known to contain the opposite properties. [0004] In efforts to combine the merits of both sides, preparation of Silicone-Epoxy hybrid material has been demonstrated. For example, WO 2022/072271 A1 describes preparation and formulation of a UV radiation curable Silicone-Epoxy hybrid resin that provides excellent adhesion and performance reliability favorable in display market. However, WO 2022/072271 A1 did not address the applicability of Silicone-Epoxy in B-stage applications, which requires initial UV cure to result in a B-stage that allows good processability followed by final heat cure. WO 2022/072271 A1 addresses this problem by combining an orthogonal cure chemistry, i.e., thiol-ene UV cure, with Silicone-Epoxy heat cure (by using HAG in place of PAG) to achieve stepwise B-stage and C-stage. Prior Art Documents Patent Documents [0005] Patent Document 1 : International Publication No. WO 2022/072271 A1 Summary of Invention Technical Problem [0006] Silicone-Epoxy hybrid material can be cured by both UV irradiation and heat by employing different types of acid generators, namely photo acid generator (PAG) and heat acid generator (HAG). An objective of the present invention is to provide a Silicone-Epoxy hybrid material having the benefits of both silicones and organic epoxies, having excellent reliability performance and adhesiveness suitable for applications in the electronic display market. Solution to Problem [0007] The curable silicone composition of the present invention comprises: [0008] (A) an organopolysiloxane comprising an average of two or more alkenyl groups represented by the following general formula: wherein R1 and R8 each independently represent a C2-30 alkenyl group; R2 to R7 each independently represent a C1 -30 monovalent aliphatic hydrocarbon group, or a C6-30 monovalent aromatic hydrocarbon group; and "n" is an integer of from 0 to 100; [0009] (B) a crosslinker with an average of three or more mercapto groups represented by the following general formula: wherein R9 each independently represents a C1 -30 monovalent aliphatic hydrocarbon group, or a C6-30 monovalent aromatic hydrocarbon group; R10 each independently represents a C1 -30 divalent aliphatic hydrocarbon group, or a C6-30 divalent aromatic hydrocarbon group; and R11 each independently represents a mercapto group or a C1 -6 alkyl group, provided that at least three of the R11's are mercapto groups; [0010] (C) an epoxy-functional silicone resin represented by the following average unit formula: (R123SiOi/2)a (R122SiO2/2)b (R12SiO3/2)c (SiO4/2)d wherein R12 each independently represents a C1 -6 monovalent aliphatic hydrocarbon group, a C6-10 monovalent aromatic hydrocarbon group, or a monovalent epoxy-substituted organic group, provided that at least about 15 mol% of the total R12 are C6-10 monovalent aromatic hydrocarbon groups; and "a", "b", "c" and "d" are numbers that satisfy the following conditions: 0<a<0.4, 0<b<0.5, 0<c<1 , 0<d<0.4, 0.1<b/c<0.6, and a+b+c+d=1 ; and about 2 to about 30 mol% of the total siloxane units have the monovalent epoxy-substituted organic groups; [0011] (D) an epoxy-functional silicone represented by the following general formula: X1-R132SiO(SiR132O)mSiR132-X1 wherein R13 each independently represents a C1 -6 monovalent aliphatic hydrocarbon group, or a C6-10 monovalent aromatic hydrocarbon group; X1 each independently represents a monovalent epoxy-substituted organic group, or an epoxy-functional siloxy group represented by the following general formula: X2-R142SiO(SiR142O)xSiR142-R15- wherein R14 each independently represents a C1 -6 monovalent aliphatic hydrocarbon group; R15 represents a C2-6 alkylene group; X2 represents a monovalent epoxy-substituted organic group; "x" represents a number of from 0 to 5; and "m" represents a number of from 0 to 100; [0012] (E) an iodonium salt type cationic photoinitiator; and [0013] (F) a cationic photoinitiator other than component (E). [0014] In various embodiments, in component (A), R1 and R8 each independently represent a vinyl group; R2, R3, R6, and R7 each independently represent a C1 -6 alkyl group; R4 and R5 each independently represent a C6-12 aryl group; and "n" is an integer of from 0 to 40. [0015] In various embodiments, in component (B), R9 each independently represents a C1 - 6 alkyl group; R10 each independently represents a C1 -6 alkylen