Terephthalic acid copolyamides

• US 5,378,800 A
• Filed: 08/12/1992
• Issued: 01/03/1995
• Est. Priority Date: 12/12/1990
• Status: Expired due to Term

• Current Assignee: Du Pont Taiwan Limited (Corteva, Inc.), E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: Du Pont Taiwan Limited (Corteva, Inc.), E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Pagilagan, Rolando U., Mok, Steven L.
• Primary Examiner(s): CAIN, EDWARD J
• Assistant Examiner(s): Hampton-Highhtower, P.
• Application Number:
  US07/917,024
• Time in Patent Office: 874 Days
• Field of Search: 528/349, 528/347, 528/338, 528/339, 528/340, 428/395, 428/474.4
• US Class Current: 528/349
• CPC Class Codes: C08G 69/265 from at least two different diamines or at least two different dicarboxylic acids
• CPC Class Codes: D01F 6/80 from copolyamides
• CPC Class Codes: Y10T 428/2969 Polyamide, polyimide or polyester
• CPC Class Codes: Y10T 428/31725 Of polyamide

Abstract

A partially crystalline copolyamide formed from an aromatic carboxylic acid that is terephthalic acid or a mixture of terephthalic acid and isophthalic acid containing less than 40% of isophthalic acid, and an aliphatic diamine that is a mixture of hexamethylene diamine and 2-methyl pentamethylene diamine. The aliphatic diamine is at least 40%, molar basis, of hexamethylene diamine and the amount of isophthalic acid plus 2-methyl pentamethylene diamine is in the range of 15-35%, molar basis, of the total amount of aromatic carboxylic acid and aliphatic diamine. The copolyamides have a melting point of 280°-330° C. The copolyamide preferably has a heat of fusion of greater than 17 J/g. The copolyamide may be moulded into articles, spun into fibres or formed into films, and used in a wide variety of end-uses especially where high temperature properties are required.

Claims

1. A partially crystalline copolyamide formed from aromatic dicarboxylic acid and aliphatic diamine, said aromatic dicarboxylic acid consisting essentially of terephthalic acid and said aliphatic diamine consisting essentially of a mixture of hexamethylene diamine and 2-methyl pentamethylene diamine, said aliphatic diamine containing at least 40%, molar basis, of hexamethylene diamine, said copolyamide having a melting point in the range of from 280°

to 330°

C.

2. The copolyamide of claim 1 in which the amount of 2-methyl pentamethylene diamine is 15-35%, molar basis, of the total amount of aromatic carboxylic acid and aliphatic diamine.

3. The copolyamide of claim 2 in which the melting point is in excess of 300°

C.

5. A fibre formed from a partially crystalline copolyamide of claim 1.

6. The fibre of claim 5 in which the amount of 2-methyl pentamethylene diamine in the partially crystalline copolyamide is 15-35%, molar basis, of the total amount of aromatic carboxylic acid and aliphatic diamine, said copolyamide having a heat of fusion of greater than 17 J/g.

7. The fibre of claim 6 in which the fibre has a tenacity of at least 1.5 g/denier and a modulus of at least 30 g/denier.

8. The fibre of claim 7 in which the copolyamide of the fibre has an inherent viscosity, as measured on a 5 g/dL solution of m-cresol at 25°

C., in the range of 0.5 to 1.5 dL/g.

9. The fibre of claim 8 in which the inherent viscosity is in the range of 0.8 to 1.1 dL/g.

10. A moulded article made from the partially crystalline copolyamide of claim 1.

11. A film or sheet made from the partially crystalline, copolyamide of claim 1.

4. The copolyamide of claim in which the heat of fusion of the copolyamide is greater than 17 Joules/g.