Hydrolysis resistant compositions

Patent metadata

Field	Value
Publication number	US-9862821-B2
Application number	US-201314281972-A
Country	US
Kind code	B2
Filing date	Mar 12, 2013
Priority date	Aug 31, 2012
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

Polyester compositions comprising: a) at least one semi-aromatic polyester resin; b) at least one reinforcing agent; c) hydroxyapatite; d) at least one epoxy component having two or more epoxy functional groups per molecule of the epoxy component; and optionally, at least one toughener, wherein the compositions exhibit the combined property of a desirable melt viscosity stability and a desirable hydrolysis resistance to articles molded from the compositions. Articles molded or extruded from these compositions especially, electric and electronic components. Methods of maintaining melt viscosity stability of a melt-mixed composition while simultaneously retaining tensile strength in the article prepared from the melt-mixed composition.

First claim

The invention claimed is:

1. A composition comprising:
a) 40 to 89 weight percent of at least one semi-aromatic polyester resin selected from the group consisting of polyethylene terephthalate, poly(trimethylene terephthalate), and polybutylene terephthalate, polyethylene naphthalene, and combinations of these;
b) 10 to 50 weight percent of at least one reinforcing agent;
c) 0.5 to 5.0 weight percent hydroxyapatite;
d) 0.5 to 4.0 weight percent of at least one epoxy component having two or more epoxy functional groups per molecule of the epoxy component;
e) optionally, 0.5 to 15 weight percent of at least one toughener,

(d) and (e) having a combined epoxy functionality ranging from 40 and 500 milliequivalents per kilogram of the semi-aromatic polyester resin; and
wherein:
when measured according to Test (A), each subsequent melt viscosity of the polyester composition is not greater than 160% of its initial melt viscosity and
when measured according to Test (B), the tensile strength of exposed test bars comprising the polyester composition is at least 60% of that of unexposed bars comprising the same polyester composition;

whereby:
Test (A) comprises:
measuring initial melt viscosity of the polyester composition at five minutes after heating the polyester composition at a temperature between 30 and 45° C. above the melting point of the semi-aromatic polyester, and
measuring subsequent melt viscosities of the polyester composition at intervals between greater than 5 minutes and 48 minutes, including measurements at 21 and 48 minutes, while the temperature of the polyester composition is maintained between 30 and 45° C. above the melting point of the semi-aromatic polyester,

wherein the measuring is done according to ISO 11443 at 1000 sec −1 ;
and
Test (B) comprises:
measuring tensile strength of unexposed test bars comprising the polyester composition;
exposing test bars comprising the same polyester composition for a duration of at least 25 hours to steam at 100 percent relative humidity, pressure of 2 atmospheres, and temperature of 121° C.; and
measuring at the end of the duration tensile strength of the exposed test bars, wherein the measuring is done according to ISO527-1 and all test bars have been molded according to ISO527-2/1A.

2. The polyester composition of claim 1 , wherein when the semi-aromatic polyester resin is polyethylene terephthalate or polybutylene terephthalate:
the quotient of milliequivalents of epoxy functionality per kilogram of semi-aromatic polyester resin over milliequivalents of acid end groups per kilogram of semi-aromatic polyester resin ranges from 2.5 to 10; and
the product of milliequivalents of acid end groups per kilogram of semi-aromatic polyester resin times milliequivalents of epoxy functionality per kilogram of semi-aromatic polyester resin ranges from 1000 to 5000; and

when the semi-aromatic polyester is poly(trimethylene terephthalate):
the quotient of milliequivalents of epoxy functionality per kilogram of semi-aromatic polyester resin over milliequivalents of acid end groups per kilogram of semi-aromatic polyester resin ranges from 2.5 to 15; and
the product of milliequivalents of acid end groups per kilogram of semi-aromatic polyester resin times milliequivalents of epoxy functionality per kilogram of semi-aromatic polyester resin ranges from 200 to 3000.

3. The polyester composition of claim 2 , wherein (b) is selected from the group consisting of glass fibers, glass beads, glass flake, mica, and combinations of these.

4. The polyester composition of claim 2 , wherein (d) is selected from the group consisting of diphenolic epoxy condensation polymers, condensation products of glycidyl ethers and phenolic polymers, diglycidyl ether of bisphenol A polymers, tetraglycidyl ether of tetra(parahydroxyphenyl) ethane, and combinations of these.

5. The polyester composition of claim 2 , wherein (e) is selected from the group of copolymers of C 1 to C 10 alkyl acrylates, ethylene, and glycidyl methacrylate; and combinations of these.

6. The polyester composition of claim 2 , wherein the exposure duration is selected from the group consisting of: 100 hours when the semi-aromatic polyester resin is poly(butylene terephthalate), 50 hours when the semi-aromatic polyester resin is poly(trimethylene terephthalate), and 25 hours when the semi-aromatic polyester resin is poly(ethylene terephthalate).

7. The polyester composition of claim 6 , having up to 10 weight percent of (e) and wherein:
(d) is selected from the group consisting of diphenolic epoxy condensation polymers, condensation products of glycidyl ethers and phenolic polymers, diglycidyl ether of bisphenol A polymers, tetraglycidyl ether of tetra(parahydroxyphenyl) ethane, and combinations of these; and
(e) is selected from the group of copolymers of C 1 to C 10 alkyl acrylates, ethylene, and glycidyl methacrylate; and combinations of these.

8. The polyester composition of claim 1 , wherein (b) is selected from the group consisting of glass fibers, glass beads, glass flake, mica, and combinations of these.

9. The polyester composition of claim 1 , wherein (d) is selected from the group consisting of diphenolic epoxy condensation polymers, condensation products of glycidyl ethers and phenolic polymers, diglycidyl ether of bisphenol A polymers, tetraglycidyl ether of tetra(parahydroxyphenyl) ethane, and combinations of these.

10. The polyester composition of claim 1 , having up to 10 weight percent of (e).

11. The polyester composition of claim 1 , wherein (e) is selected from the group of copolymers of C 1 to C 10 alkyl acrylates, ethylene, and glycidyl methacrylate; and combinations of these.

12. The polyester composition of claim 1 , wherein the exposure duration is selected from the group consisting of: 100 hours when the semi-aromatic polyester resin is poly(butylene terephthalate), 50 hours when the semi-aromatic polyester resin is poly(trimethylene terephthalate), and 25 hours when the semi-aromatic polyester resin is poly(ethylene terephthalate).

13. An article comprising the polyester composition of claim 1 .

14. The article of claim 13 , having up to 10 weight percent of (e) and wherein:
(d) is selected from the group consisting of diphenolic epoxy condensation polymers, condensation products of glycidyl ethers and phenolic polymers, diglycidyl ether of bisphenol A polymers, tetraglycidyl ether of tetra(parahydroxyphenyl) ethane, and combinations of these; and
(e) is selected from the group of copolymers of C 1 to C 10 alkyl acrylates, ethylene, and glycidyl methacrylate; and combinations of these.

15. The article of claim 14 , in the form of an electronic part, an electrical part, an electrical part in an electric vehicle, an electrical part in a hybrid vehicle, a connector, a plug, a sensor, a relay, a solenoid, or a switch.

16. The article of claim 13 , wherein a test plate comprising the same polyester composition as the article has a Comparative Tracking Index of at least 400.

17. A method of making, comprising:
melt-mixing, to form a polyester composition:
a) 40 to 89 weight percent of at least one semi-aromatic polyester resin selected from the group consisting of polyethylene terephthalate, poly(trimethylene terephthalate), and polybutylene terephthalate, polyethylene naphthalene, and combinations of these;
b) 10 to 50 weight percent of at least one reinforcing agent;
c) 0.5 to 5.0 weight percent hydroxyapatite;
d) 0.5 to 4.0 weight percent of at least one epoxy compound having

Assignees

• Du Pont

Inventors

• Peacock Judith Alison

Classifications

• C08L67/02 Primary

  Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence) · CPC title

• C08K3/32

  Phosphorus-containing compounds · CPC title

• C08K5/523

  with hydroxyaryl compounds · CPC title

• C07F9/301

  Acyclic saturated acids which can have further substituents on alkyl · CPC title

• C08K7/14

  Glass · CPC title