Process for the preparation of mineral filled polyamide and polyester compositions exhibiting increased melt flow and articles formed therefrom

Abstract

A process for the preparation of mineral filled polyamide and polyester compositions having increased melt flow, in which polyamide or polyester is melt-blended with at least one aromatic carboxylic acid and/or anhydride, mineral filler, and optionally, one or more additional components, wherein the aromatic carboxylic acid and/or anhydride has a melting point that is no greater than the onset temperature of the melting point endotherm of the polyamide or polyester.

Description

Claims

1. A process for the preparation of a mineral-reinforced composition exhibiting high melt flow, comprising melt-blending a thermoplastic polymer comprising at least one polyamide and/or at least one polyester with about 0.1 to about 10 weight percent, based on the total weight of polyamide and/or polyester, of at least one aromatic dicarboxylic acid, aromatic dicarboxylic acid anhydride, aromatic tricarboxylic acid, and/or aromatic tricarboxylic acid anhydride with at least one mineral filler; and optionally, with one or more additional components, wherein the aromatic dicarboxylic acid, aromatic dicarboxylic acid anhydride, aromatic tricarboxylic acid, and/or aromatic tricarboxylic acid anhydride has a melting point that is no greater than the onset temperature of the melting point endotherm of the polyamide or polyester.

2. The process of claim 1, wherein the aromatic dicarboxylic acid, aromatic dicarboxylic acid anhydride, aromatic tricarboxylic acid, and/or aromatic tricarboxylic acid anhydride is present in about 0.05 to about 2 weight percent, based on the total weight of polyamide and/or polyester.

3. The process of claim 1, wherein the aromatic dicarboxylic acid, aromatic dicarboxylic acid anhydride, aromatic tricarboxylic acid, and/or aromatic tricarboxylic acid anhydride is present in about 0.1 to about 1 weight percent, based on the total weight of polyamide and/or polyester.

4. The process of claim 1, wherein the aromatic dicarboxylic acid is phthalic acid.

5. The process of claim 1, wherein the aromatic dicarboxylic acid anhydride is phthalic anhydride.

6. The process of claim 1, wherein the aromatic tricarboxylic acid anhydride is trimellitic anhydride.

7. The process of claim 1, wherein the polyamide is selected from one or more of the groups consisting of polyamide 6; polyamide 6,6; polyamide 4,6; polyamide 6,10; polyamide 6,12; polyamide 11; and polyamide 12.

8. The process of claim 1, wherein the polyamide is selected from one or more of the groups consisting of poly(m-xylylene adipamide), poly(dodecamethylene terephthalamide), poly(decamethylene terephthalamide), poly(nonamethylene terephthalamide), hexamethylene adipamide/hexamethylene terephthalamide copolyamide; and hexamethylene terephthalamide/2-methylpentamethylene terephthalamide copolyamide.

9. The process of claim 1, wherein the polyester is selected from one or more of the group consisting of poly(ethylene terephthalate), poly(1,4-butylene terephthalate), poly(propylene terephthalate), poly(1,4-butylene naphthalate), poly(ethylene naphthalate), and poly(1,4-cyclohexylene dimethylene terephthalate).

10. The process of claim 1, wherein the mineral filler is selected from one or more of calcium carbonate, talc, mica, calcined clay, magnesium sulfate, lizardite, ceramic beads, fumed silica, calcium hydroxide, barite, feldspar, graphite, perlite, vermiculite, wollastonite, and attapulgite.

11. The process of claim 10, wherein the mineral filler is calcium carbonate.

12. The process of claim 1, wherein the composition further comprises a reinforcing agent.

13. The process of claim 12, wherein the reinforcing agent is one or more of glass fibers, carbon fibers, wollastonite, and aramids.

14. An article molded from the composition produced by the process of claim 1.

15. The article of claim 14 in the form of a computer housing, a fan, a fan shroud, a wheel cover, or a switch housing.