Molded article comprising polyamide resin composition
The present invention provides a molded article comprising a polyamide resin composition, wherein (the average concentration of alkali metal and/or alkaline earth metal elements in a region within a depth of 3 μm from the surface of the molded article)/(the average concentration of alkali metal and/or alkaline earth metal elements in a region except for the region within a depth of 3 μm from the surface of the molded article)>2.
1. A molded article comprising a polyamide resin composition comprising a polyamide resin and at least one alkali metal and/or alkaline earth metal element mixed therein, wherein
(the average concentration of alkali metal and/or alkaline earth metal elements in a region within a depth of 3 μm from the surface of the polyamide resin composition of the molded article)/(the average concentration of alkali metal and/or alkaline earth metal elements in a region of the polyamide resin composition of the molded article except for the region within a depth of 3 μm from the surface of the polyamide resin composition of the molded article)>2.
2. The molded article according to claim 1 , wherein the molded article comprises a lower carboxylate of an alkali metal and/or an alkaline earth metal in a region within a depth of 1 μm from the surface of the polyamide resin composition of the molded article.
3. The molded article according to claim 1 , wherein the molded article comprises a carbonate of an alkali metal and/or an alkaline earth metal in a region within a depth of 10 nm from the surface of the polyamide resin composition of the molded article.
4. The molded article according to claim 1 , wherein the molded article
comprises a metal aluminate, and
has one or more peaks each in ranges of 0 to 30 ppm, 30 to 60 ppm, and 70 to 100 ppm in solid-state 27Al-NMR measurement.
5. The molded article according to claim 1 , wherein the molded article has Mw of 50000 or higher and Mw/Mn of 3 or higher.
6. The molded article according to claim 1 , wherein the soluble content in hexafluoroisopropanol (HFIP) of a polyamide resin portion contained in the polyamide resin composition is 50% by mass or less of the polyamide resin portion contained in the polyamide resin composition.
7. A molded article comprising a polyamide resin composition comprising a polyamide resin and at least one alkali metal and/or alkaline earth metal element mixed therein, wherein the molded article satisfies the following expression:
α/β>2, wherein
α represents the average concentration of alkali metal and/or alkaline earth metal elements in a region within a depth of 3 μm from the surface of the polyamide resin composition of the molded article after heat aging treatment at 230° C. for 300 hours or longer, and
β represents the average concentration of alkali metal and/or alkaline earth metal elements in a region of the polyamide resin composition of the molded article except for the region within a depth of 3 μm from the surface of the polyamide resin composition of the molded article after heat aging treatment at 230° C. for 300 hours or longer.
8. The molded article according to claim 7 , wherein the molded article comprises a lower carboxylate of an alkali metal and/or an alkaline earth metal in a region within a depth of 1 μm from the surface of the polyamide resin composition of the molded article after heat aging treatment at 230° C. for 300 hours or longer.
9. The molded article according to claim 7 , wherein the molded article contains a carbonate of an alkali metal and/or an alkaline earth metal in a region within a depth of 10 nm from the surface of the polyamide resin composition of the molded article after heat aging treatment at 230° C. for 300 hours or longer.
10. The molded article according to claim 7 , wherein the molded article
comprises a metal aluminate, and
has one or more peaks each in ranges of 0 to 30 ppm, 30 to 60 ppm, and 70 to 100 ppm in solid-state 27Al-NMR measurement
after heat aging treatment at 230° C. for 300 hours or longer.
11. The molded article according to claim 7 , wherein the molded article has Mw of 50000 or higher and Mw/Mn of 3 or higher
after heat aging treatment at 230° C. for 300 hours or longer.
12. The molded article according to claim 7 , wherein the soluble content in hexafluoroisopropanol (HFIP) of a polyamide resin portion contained in the polyamide resin composition is 50% by mass or less of the polyamide resin portion contained in the polyamide resin composition after heat aging treatment at 230° C. for 300 hours or longer.
13. The molded article according to claim 1 , wherein the molded article is an automobile part.
14. The molded article according to claim 1 , wherein the molded article is an automobile underhood part.
15. The molded article according to claim 1 , wherein the molded article is a hollow part.
16. The molded article according to claim 7 , wherein the molded article is an automobile part.
17. The molded article according to claim 7 , wherein the molded article is an automobile underhood part.
18. The molded article according to claim 7 , wherein the molded article is a hollow part.