# US 4,393,184 A · Lens having a high refractive index with a low dispersion

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- Number: US 4,393,184 A
- Document ID: US4393184A
- Status: Granted
- Kind: A
- Application number: 06/315,354
- Filed: 1981-10-26
- Granted: 1983-07-12
- Earliest claimed: 1980-12-15
- Assignees: Hoya Lens Corporation
- Inventors: Niro Tarumi; Shigeo Komiya; Mitsuo Sugimura
- Web page: https://patentgrep.com/patent/US4393184A

## CPC

- G02B 1/04: made of organic materials, e.g. plastics (G02B1/08 takes precedence)
- C08F 220/301: {and one oxygen in the alcohol moiety}
- G02B 1/041: {Lenses}
- Y10T 428/31649: Ester, halide or nitrile of addition polymer
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A lens having a high refractive index with a low dispersion produced by copolymerizing a polyfunctional allyl monomer with at least one monomer selected from the group represented by the general formula A: ##STR1## X: H, CH.sub.3, Cl Y: H, CH.sub.3, C.sub.2 H.sub.5, n-C.sub.3 H.sub.7, iso-C.sub.3 H.sub.7, OCH.sub.3, C.sub.6 H.sub.11, Cl, Br, CH.sub.2 Cl, CH.sub.2 Br, C.sub.6 H.sub.5, CH.sub.2 C.sub.6 H.sub.5, SCH.sub.3 m=0, 1, 2 n=0, 1, 2, 3, 4, 5. This lens is excellent in its transmittance, pencil hardness, impact resistance, dyeability, coating adhesion, solvent resistance, workability, etc.

## Claims

### Claim 1

A lens having a low dispersion and a high refractive index, comprising a copolymer of at least one polyfunctional allyl monomer selected from the group consisting of diallylorthophthalate, diallylisophthalate, diallylterephthalate, diallylchlorendate, triallylcyanurate and triallylisocyanurate with at least one monomer of the formula ##STR3## in which X is H, CH.sub.3 or Cl,
Y is H, CH.sub.3, C.sub.2 H.sub.5, n-C.sub.3 H.sub.7, iso-C.sub.3 H.sub.7, OCH.sub.3, C.sub.6 H.sub.11, Cl, Br, CH.sub.2 Cl, CH.sub.2 Br, C.sub.6 H.sub.5, CH.sub.2 C.sub.6 H.sub.5 or SCH.sub.3,
m is 0, 1 or 2, and
n is 0, 2, 3, 4 or 5,
the polyfunctional allyl monomer comprising about 70 to 90% of the copolymer by weight, at most about 10% by weight of the polyfunctional allyl monomer comprising a trifunctional allyl monomer.

### Claim 2 (depends on 1)

A lens according to claim 1, having a transmittance of at least about 89%, a refractive index of at least about 1.568, a pencil hardness of at least about H and an Abbe's number of at least about 34.