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US 2014/0275346 A1Published application
Hydrolysis resistant compositions
AssigneeE. I. Du Pont de Nemours and Company
InventorJudith Alison Peacock
Life of this patent
Estimating the term…
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.
Claims20
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 at least one subsequent melt viscosity of the polyester composition during an interval between greater than 5 minutes 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.
18 more elements
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 two or more epoxy functional groups per molecule;
- 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 resin, and
- measuring at least one subsequent melt viscosity of the polyester composition during an interval between greater than 5 minutes 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 resin,
- 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 ISO-2/1A.
19 more elements
Dependencies are inferred from the claim text.