Photocurable adhesive and bonding process employing same

• US 20050061429A1
• Filed: 09/15/2004
• Published: 03/24/2005
• Est. Priority Date: 09/18/2003
• Status: Abandoned Application

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Hosaka, Shunichi
• Application Number:
  US10/940,810
• Publication Number:
  US 20050061429A1
• Time in Patent Office: Days
• US Class Current: 156/273.300
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: C08G 65/18 Oxetanes
• CPC Class Codes: C08L 71/02 Polyalkylene oxides
• CPC Class Codes: G03F 7/038 Macromolecular compounds which are rendered insoluble or differentially wettable G03F7/075 takes precedence; macromolecular azides G03F7/012; macromolecular diazonium compounds G03F7/021
• CPC Class Codes: G11B 7/256 of layers improving adhesion between layers
• CPC Class Codes: G11B 7/26 Apparatus or processes specially adapted for the manufacture of record carriers

Abstract

An actinic radiation curable adhesive is provided that includes 50 to 99 wt % of a bifunctional and/or a polyfunctional oxetane compound, 0 to 40 wt % of a monofunctional oxetane compound, 1 to 50 wt % of an epoxy compound having a cyclic structure, and a catalytic amount of a photoinitiator. The adhesive has an initial viscosity of 10 to 1,000 mPa·s and a viscosity at gel point of 1×10¹ to 9×10⁶ Pa·s. There is also provided a process for bonding an adherend A and a different adherend B, the process including forming an adhesive layer by coating a surface of the adherend A with the above adhesive at a thickness of 0.05 to 50 μm, irradiating the adhesive layer with actinic radiation, and bonding the adherend B to the adhesive layer after 0.01 to 4 times the time required for gelling of the adhesive layer has passed following the start of irradiation with actinic radiation.

Claims

1. An actinic radiation curable adhesive comprising:

50 to 99 wt % of a bifunctional and/or a polyfunctional oxetane compound (Component A);

0 to 40 wt % of a monofunctional oxetane compound (Component B);

1 to 50 wt % of an epoxy compound having a cyclic structure (Component C); and

a catalytic amount of a photoinitiator;

the adhesive having an initial viscosity of 10 to 1,000 mPa·

s and a viscosity at gel point of 1×

10¹ to 9×

10⁶ Pa·

s.

2. The actinic radiation curable adhesive according to claim 1, wherein the adhesive further comprises a photosensitizer or a silane coupling agent.

3. The actinic radiation curable adhesive according to claim 1, wherein the adhesive is cured by irradiation with UV rays or visible light as the actinic radiation.

4. The actinic radiation curable adhesive according to claim 1, wherein the adhesive has a time t (gel) required for gelling of 2 to 30 minutes after irradiation with UV rays as the actinic radiation or 5 to 30 minutes after irradiation with visible light as the actinic radiation.

5. The actinic radiation curable adhesive according to claim 1, wherein the bifunctional and/or the polyfunctional oxetane compound (Component A) comprises a compound represented by Formula (1)

6. The actinic radiation curable adhesive according to claim 1, wherein the bifunctional and/or the polyfunctional oxetane compound (Component A) comprises a bifunctional oxetane compound having, as a linking group located between the two oxetanyl groups, a phenylene group, a biphenylene group, a naphthalene group, a group in which two phenylene groups are bonded via a methylene group, or a binaphthalene group.

7. The actinic radiation curable adhesive according to claim 1, wherein the monofunctional oxetane compound (Component B) comprises a compound represented by Formula (2)

8. The actinic radiation curable adhesive according to claim 1, wherein the monofunctional oxetane compound (Component B) comprises a hydroxyl group-containing monofunctional oxetane compound.

9. The actinic radiation curable adhesive according to claim 1, wherein the epoxy compound having a cyclic structure (Component C) comprises a compound in which the cyclic structure is an aromatic group or a cycloalkyl group.

10. The actinic radiation curable adhesive according to claim 1, wherein the photoinitiator is an onium salt.

11. The actinic radiation curable adhesive according to claim 10, wherein the onium salt is an aromatic iodonium salt or an aromatic sulfonium salt.

12. A bonding process for bonding an adherend A and an adherend B. which is different from adherend A, the process comprising:

a step of forming an adhesive layer by coating a surface of the adherend A with the actinic radiation curable adhesive according to claim 1 at an adhesive thickness of 0.05 to 50 μ

m;

a step of irradiating the adhesive layer with actinic radiation; and

a step of bonding the adherend B to the adhesive layer after 0.01 to 4 times a time t (gel) required for gelling of the adhesive layer has passed following the start of the irradiation with actinic radiation.