COMPOSITION OF POLYAMIDE RESIN AND METHOD OF ITS PRODUCTION

Abstract

A polyamide resin composition includes: (A) a crystalline polyamide resin including a polycapramide resin as the main component; (B) a semi-aromatic amorphous polyamide resin; (C) an inorganic reinforcing material; (D) a master batch of carbon black; and (E) a copper compound, wherein, as (C) the inorganic reinforcing material, the polyamide resin composition includes (C-1) a glass fiber, (C-2) a needle-shaped wollastonite, and (C-3) a plate-crystal inorganic reinforcing material, a melt flow rate (MFR) and a cooling crystallization temperature (TC2) of the polyamide resin composition fall within respective predetermined ranges, and the mass ratios and component contents satisfy specified conditions;By using polyamide resin, not only is a molded product obtained that has a higher level of external appearance when the mold temperature is less than or equal to 100 °C during molding, but also excellent weather resistance of the external surface appearance of the molded product.

Claims

1. A polyamide resin composition comprising: (A) a crystalline polyamide resin including a polycapramide resin as the main component; (B) a semi-aromatic amorphous polyamide resin; (C) an inorganic reinforcing material; (D) a master batch of carbon black; and (E) a copper compound, wherein, as (C) the inorganic reinforcing material, the polyamide resin composition includes (C-1) a glass fiber, (C-2) a needle-shaped wollastonite, and (C-3) a plate crystal inorganic reinforcing material, a melt flow rate (MFR) of the polyamide resin composition with a moisture content less than or equal to 0.05% is greater than or equal to 4.0 g / 10 min and less than 13.0 g / 10 min, a cooling crystallization temperature (TC2) of the polyamide resin composition measured by a differential scanning calorimeter (DSC) is greater than or equal to 180 °C and less than or equal to 185 °C, a mass ratio of (A) and (B) satisfies 0.5 < (B) / (A) < 0.8, and when a total of (A), (B), (C), and (D) is assumed to be 100 parts by mass, a content of (E) is from 0.001 to 0.1 parts by mass, and the content of the components satisfies the following formulas: 30 parts by mass < (A) + (B) + (D) < 60 parts by mass, 13 parts by mass < (B) < 23 parts by mass, 1 part by mass < (D) < 5 parts by mass, 20 parts by mass < (C) < 40 parts by mass, 8 parts by mass < (C-2) < 25 parts by mass, 8 parts by mass < (C-3) < 25 parts by mass, and 40 parts by mass < (Cl) + (C-2) + (C-3) < 70 parts by mass.

2. A method for producing the polyamide resin composition according to claim 1, wherein (A) the crystalline polyamide resin including polycapramide resin as the main component, (B) the semi-aromatic amorphous polyamide resin, (D) the master batch of carbon black, and a dispersion of (E) the copper compound are premixed and introduced into a hopper portion of an extruder, and (C) the inorganic reinforcing material is introduced according to a side-feed method.