Thermoplastic melt-mixed composition with epoxy-amino acid compound heat stabilizer and processes for their preparation

1. A thermoplastic melt-mixed composition comprising:

a) 15 to 89.5 weight percent of a poly(hexamethylene hexanediamide);

b) 0.5 to 10 weight percent of a poly(amino acid)-polyol compound provided by reacting:

b1) 90 to 10 weight percent of one or more amino acids selected from the group consisting of primary amino acids and secondary amino acids and combinations of these; said amino acid having no more than one hydroxyl group;

b2) 10 to 90 weight percent of one or more polyepoxy compounds comprising at least two or more epoxy groups; the polyepoxy compounds having an epoxide equivalent weight of 43 to 4000 g/equivalent as determined by calculation, or if one or more of the polyepoxy compounds is an oligomer, by titration using ASTM D1652-11 method; and a number average molecular weight (Mn) of less than 8000;

wherein the weight percent of component b) is based on the total weight of b1) and b2); said poly(amino acid)-polyol compound having a range of at least 10 percent conversion of epoxy equivalents of component (b1) up to, but excluding, the gel point of the components b1) and b2) as determined with 1 H NMR analysis of the poly(amino acid)-polyol;

c) 10 to 60 weight percent of reinforcing agent;

d) 0 to 30 weight percent polymeric toughener; and

e) 0 to 10 weight percent further additives;

wherein the weight percentages a), b), c), d), and e) are based on the total weight of the thermoplastic melt-mixed composition.

2. The thermoplastic melt-mixed composition of claim 1 wherein the one or more amino acids have a number average molecular weight of up to 500.

3. The thermoplastic melt-mixed composition of claim 1 wherein the poly(amino acid)-polyol compound has a number average molecular weight of about 200 to about 10000.

4. The thermoplastic melt-mixed composition of claim 1 wherein said poly(amino acid)-polyol compound has at least 25 percent conversion of epoxy equivalents.

5. The thermoplastic melt-mixed composition of claim 1 wherein the amino acid is selected from the group consisting of 6-aminohexanoic acid, lysine, 11-aminoundecanoic acid, 4-aminobenzoic acid; and salts of these compounds.

6. The thermoplastic melt-mixed composition of claim 1 wherein the polyepoxy compound is trimethylolpropane triglycidyl ether.

7. A molded or extruded article made from the thermoplastic melt-mixed composition of claim 1 .

8. The molded or extruded thermoplastic article of claim 7 wherein 2 mm thick is test bars, prepared from said melt-mixed composition and tested according to ISO 527-2/1BA, and exposed at a test temperature of 230° C. for a test period of 500 hours, in an atmosphere of air, have on average, a retention of tensile strength of at least 25 percent, as compared with that of an unexposed control of identical composition and shape.

9. A process for providing a thermoplastic melt-mixed composition comprising:

A) melt-blending:

a) 15 to 89.5 weight percent of poly(hexamethylene hexanediamide);

b) 0.5 to 10 weight percent of a poly(amino acid)-polyol compound provided by reacting:

b1) 90 to 10 weight percent of one or more amino acids selected from the group consisting of primary amino acids and secondary amino acids and combinations of these; said amino acid having no more than one hydroxyl group; and

b2) 10 to 90 weight percent of a polyepoxy compound comprising at least two or more epoxy groups; the polyepoxy compound having a epoxide equivalent weight of 43 to 4000 g/equivalent as determined by calculation, or if the polyepoxy compound is an oligomer, by titration using ASTM D1652-11 method; and a number average molecular weight (M n ) of less than 8000;

c) 10 to 60 weight percent of reinforcing agent;

d) 0 to 30 weight percent polymeric toughener; and

e) 0 to 10 weight percent further additives;

to provide said thermoplastic melt-mixed composition; wherein the weight percent of b) is based on the total weight of b1) and b2); said poly(amino acid)-polyol compound having a range of at least 10 percent conversion of epoxy equivalents of component b1) up to, but excluding, the gel point of the components b1) and b2) as determined with 1 H NMR analysis of the poly(amino acid)-polyol compound.