Sealant for liquid crystal and liquid-crystal display cell made with the same

• US 7,678,433 B2
• Filed: 05/18/2004
• Issued: 03/16/2010
• Est. Priority Date: 05/21/2003
• Status: Expired due to Fees

• Current Assignee: Nippon Kayaku Company Limited
• Original Assignee: Nippon Kayaku Company Limited
• Inventors: Koyanagi, Hiroo, Hirano, Masahiro, Ichimura, Sumio, Imaizumi, Masahiro, Ochi, Naoyuki, Nishihara, Eiichi, Kudo, Masaru, Asano, Toyofumi
• Primary Examiner(s): HON, SOW FUN
• Application Number:
  US10/555,898
• Publication Number:
  US 20070020405A1
• Time in Patent Office: 2,128 Days
• Field of Search: 428/1.1, 428 153- 154, 428/355.EP, 428/355.AC, 428/1.5, 252/299.01, 252/299.5, 349/122, 349/153, 525/530
• US Class Current: 428/1.5
• CPC Class Codes: C08F 290/06 Polymers provided for in subclass C08G
• CPC Class Codes: C08F 290/061 Polyesters; Polycarbonates
• CPC Class Codes: C08L 33/066 containing -OH groups
• CPC Class Codes: C08L 33/16 Homopolymers or copolymers of esters containing halogen atoms
• CPC Class Codes: C09K 2323/05 Bonding or intermediate layer characterised by chemical composition, e.g. sealant or spacer
• CPC Class Codes: C09K 2323/055 Epoxy
• CPC Class Codes: C09K 2323/057 Ester polymer, e.g. polycarbonate, polyacrylate or polyester
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: Y10T 428/287 including epoxy group or epoxy polymer
• CPC Class Codes: Y10T 428/2891 including addition polymer from alpha-beta unsaturated carboxylic acid [e.g., acrylic acid, methacrylic acid, etc.] Or derivative thereof

Abstract

An objective of this application is to provide a sealant for liquid crystals witch is extremely less apt to contaminate liquid crystals and has high adhesion strength. This application discloses a sealant for liquid crystals comprising as essential ingredients (a) a radiation-curable resin represented by the general formula (1):

wherein R¹ represents a hydrogen atom or a methyl group, R² represents a hydrogen atom, a halogen atom, a hydroxyl group, a linear, branch or cyclic monovalent alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, m represents an integer of 1 to 4, and may be the same or different, R³ represents a hydrogen atom or a methyl group, and the number n of the repeating units is a positive number in the range of 0 to 20; (b) a photopolymerization initiator; and (c) an inorganic filler having an average particle diameter of 3 μm or less.

Claims

1. A sealant for liquid crystals comprising as essential ingredients (a) a radiation curable resin represented by the general formula (2):

2. The sealant for liquid crystals according to claim 1, wherein the radiation curable resin (a) has a content of 30% by weight to 80% by weight based on the total amount of the sealant for liquid crystals.

3. The sealant for liquid crystals according to claims 1, wherein the radiation curable resin (a) has a viscosity of 30 to 500 Pa·

s.

4. The sealant for liquid crystals according to claim 1 wherein the radical type photopolymerization initiator (b) is a carbazole initiator.

5. The sealant for liquid crystals according to claim 1, wherein the heat-curing agent (e) is a dihydrazide.

6. The sealant for liquid crystals according to claim 5, wherein the dihydrazide is a dihydrazide having a skeleton of isophthalic dihydrazide and/or valine hydantoin.

7. The sealant for liquid crystals according to claim 1, wherein the heat-curing agent (e) is a polyhydric phenol.

8. The sealant for liquid crystals according to claim 1, further comprising (f) a silane coupling agent.

9. The sealant for liquid crystals according to claim 8, wherein the silane coupling agent is a silane coupling agent having an amino group.

10. A liquid crystal display cell which is sealed with a cured product of a sealant for liquid crystals according to claim 1.

11. A process for producing a liquid crystal display cell comprising dropping liquid crystals inside a sealant for liquid crystals according to claim 1 formed on a substrate and attaching another substrate thereto.