# US 4,398,015 A · Fiber-forming polyesters of aromatic ketohydroxy acids

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,398,015 A
- Document ID: US4398015A
- Status: Granted
- Kind: A
- Application number: 06/404,871
- Filed: 1982-08-03
- Granted: 1983-08-09
- Earliest claimed: 1982-08-03
- Assignees: E. I. Du Pont de Nemours and Company
- Inventors: August H. Frazer
- Web page: https://patentgrep.com/patent/US4398015A

## CPC

- C08L 67/06: Unsaturated polyesters
- C08G 63/6822: {derived from hydroxy carboxylic acids}
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

## Abstract

Homopolyesters and copolyesters of specific ketohydroxy acids and which exhibit melt-anisotropy and are melt-spinnable into oriented filaments that can be heat treated to high tenacity.

## Claims

### Claim 1

Fiber-forming melt-spinnable polyester that is optically anisotropic in the melt and consists essentially of the following amounts of recurring units of the structural formulas:
(a) 25-100 mol % ##STR5## and (b) 0-75 mol % ##STR6## wherein both of R.sup.1 and R.sup.2 are H, CH.sub.3 or Cl or R.sup.1 is H and R.sup.2 is CH.sub.3 or Cl;
both of R.sup.3 and R.sup.4 are H, CH.sub.3 or Cl or R.sup.3 is H and R.sup.4 is CH.sub.3 or Cl; and
Ar is m- or p-phenylene,
provided, however, when the amount of (a) is 90-100 mol %, Ar is m-phenylene in at least 30% of the (a) units, and provided further, however, when the amount of (a) is 100 mol % and only one species of (a) is present, R.sup.1 and R.sup.2 are both Cl, and provided still further, however, in copolyesters consisting essentially of two or more different species of (a), only one of said species is substituted and R.sup.1 and R.sup.2 therein are Cl.

### Claim 2 (depends on 1)

Homopolyester of claim 1.

### Claim 3 (depends on 1)

Copolyester of claim 1.

### Claim 4 (depends on 3)

Copolyester of claim 3 containing units of (b).

### Claim 5 (depends on 4)

Copolyester of claim 4 containing 40-60 mol % units of (b).

### Claim 6 (depends on 4)

Copolyester of claim 4 wherein the unit of (b) is oxybenzoyl.

### Claim 7 (depends on 3)

Filament of the copolyester of claim 3.

### Claim 8 (depends on 3)

Shaped article of the copolyester of claim 3.

### Claim 9 (depends on 3)

Film of the copolyester of claim 3.