Optical resin materials with distributed refractive index, process for producing the materials, and optical conductors using the materials

US5541247A · kind A · utility

Inventor

• Yasuhiro Koike · Yokohama, JP

Key dates

• Filing date: Jun 17, 1993
• Grant date: Jul 30, 1996
• Expiry date: Jun 17, 2013

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S525/932
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

An optical resin, of which the refractive index continuously changes in a specific direction, is produced by filling a polymerization container with a mixed solution containing at least one type of polymerizable monomer or polymerizable monomer sol and at least one type of substance whose solubility parameter differs by 7 (cal/cm.sup.3).sup. 1/2 or less and refractive index by 0.001 or more from those of a polymer produced by polymerization of the monomer, and by subjecting the mixture to polymerization reaction by applying heat or energy rays to the container from outside so that the polymerization reaction starts and progresses preferentially from a particular region of the mixture, thus forming a concentration gradient of the substance having different refractive index. The polymerization container may be made of a polymer which swells and dissolves into the mixed solution from an inner wall thereof. After completing the polymerization reaction, the optical resin is subjected to hot drawing to obtain an optical conductor. Further, post-treatment based on crosslinking reaction is applied to improve heat resistance.