Photochromic material and rewritable optical recording medium

• US 5,164,287 A
• Filed: 02/14/1991
• Issued: 11/17/1992
• Est. Priority Date: 02/17/1990
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Nomura, Kenji, Nagae, Suguru, Nakaki, Yoshiyuki, Tsutsumi, Kazuhiko, Tsunoda, Sei
• Primary Examiner(s): Bowers, Jr., Charles L.
• Assistant Examiner(s): McPherson, John A.
• Application Number:
  US07/655,999
• Time in Patent Office: 642 Days
• Field of Search: 430/345, 430/19, 430/962, 430/270, 430/495, 430/945, 430/20, 365/108
• US Class Current: 430/345
• CPC Class Codes: C07D 495/10 Spiro-condensed systems
• CPC Class Codes: C08F 20/38 Esters containing sulfur
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials
• CPC Class Codes: G03C 1/685 Compositions containing spiro-condensed pyran compounds or derivatives thereof, as photosensitive substances
• CPC Class Codes: G11B 7/244 comprising organic materials only
• CPC Class Codes: G11B 7/245 containing a polymeric component
• CPC Class Codes: G11B 7/25 containing liquid crystals
• CPC Class Codes: G11B 7/2531 comprising glass
• CPC Class Codes: G11B 7/2532 comprising metals
• CPC Class Codes: G11B 7/2533 comprising resins
• CPC Class Codes: G11B 7/2585 based on aluminium
• CPC Class Codes: Y10S 430/146 Laser beam

Abstract

A photochromic material containing a copolymer of a spirobenzothiopyran derivative prepolymer and a liquid crystal prepolymer. In addition, a rewritable optical recording medium using the photochromic material. A rewritable optical recording medium obtained by coating a dispersed material, which is obtained by uniformly dispersing a spirobenzothiopyran derivative compound in a thermoplastic resin, on a substrate. A photochromic material capable of controlling a colored state and a decolorized state in a photon mode or a heat mode using an ultraviolet light source and a near-infrared light source. A rewritable optical recording medium capable of rewriting an information in a photon mode using a semiconductor laser.

Claims

1. A photochromic material containing a copolymer of a spirobenzothiopyran derivative prepolymer expressed by the following formula (I) and a liquid crystal prepolymer expressed by the following formula (II):

##STR16## wherein R₁ is one selected from the group consisting of a hydrogen atom and a methyl group;

R₂ is one selected from the group consisting of a hydrogen atom, a hydroxyl group, a halogen atom, an amino group, a lower alkoxy group and an aryl group;

R₃ is one selected from the group consisting of a hydrogen atom, a hydroxyl group, a halogen atom, an amino group, a lower alkoxy group and an aryl group; and

m is an integer of 1 to 20;

##STR17## wherein R₄ is one selected from the group consisting of a hydrogen atom and a methyl group;

R₅ is one selected from the group consisting of a nitryl group, a lower alkoxy group, --OC₆ H₁₃ and ##STR18## and n is an integer of 1 to 20.

2. A photochromic material as set forth in claim 1, wherein said m is an integer of 1 to 6.

3. A photochromic material as set forth in claim 1, wherein said m is 2 and said R₁, R₂ and R₃ are all a hydrogen atom.

4. A photochromic material as set forth in claim 1, wherein said m is 6 and said R₁, R₂ and R₃ are all a hydrogen atom.

5. A photochromic material as set forth in claim 1, wherein said n is an integer of 1 to 6.

6. A photochromic material as set forth in claim 1, wherein said n is 2, said R₄ is a hydrogen atom and said R₅ is --OCH₃.

7. A photochromic material as set forth in claim 1, wherein said n is 2, said R₄ is a hydrogen atom and said R₅ is --CN.

8. A photochromic material as set forth in claim 1, wherein said n is 6, said R₄ is a hydrogen atom and said R₅ is --OCH₃.

9. A photochromic material as set forth in claim 1, wherein said n is 6, said R₄ is a hydrogen atom and said R₅ is --CN.

10. A photochromic material as set forth in claim 1, wherein said m is same as said n.

11. A photochromic material as set forth in claim 1, wherein said spirobenzothiopyran derivative prepolymer is used in a quantity of 1 to 50 parts by weight based on 100 parts by weight of said liquid crystal prepolymer.