Polyacetal resin composition and molded article thereof

Patent metadata

Field	Value
Publication number	US-10030136-B2
Application number	US-201515300064-A
Country	US
Kind code	B2
Filing date	Mar 27, 2015
Priority date	Mar 28, 2014
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

The present invention provides a polyacetal resin composition containing 100 parts by mass of a polyacetal resin (A) and 10 parts by mass or more and 100 parts by mass or less of a glass filler (B), in which when a molded article formed of the polyacetal resin composition by molding is fractured by application of tensile force, the surface of the glass filler (B) protruding from a fractured surface of a fractured molded article is covered with a component containing the polyacetal resin (A) having an average thickness of 0.2 μm or more and 3.0 μm or less.

First claim

The invention claimed is:

1. A molded article formed from a polyacetal resin composition containing
100 parts by mass of a polyacetal resin (A),
10 parts by mass or more and 100 parts by mass or less of a glass filer (B), and
a polyethylene resin (C) having a weight-average molecular weight of 500,000 or less, wherein,
an amount of the polyethylene resin (C) having a weight-average molecular weight of 500,000 or less in a surface layer of the molded article is larger than an amount of the polyethylene resin (C) having a weight-average molecular weight of 500,000 or less in a layer surface deeper than 1,000 μm from the surface layer of the molded article as measured by cutting out the layer, and
when the molded article is fractured by application of tensile force, the surface of the glass filler (B) protruding from a fractured surface of a fractured molded article is covered with a component comprising the polyacetal resin (A) having an average thickness of 0.2 μm or more and 3.0 μm or less.

2. A molded article formed from a polyacetal resin composition containing
100 parts by mass of a polyacetal resin (A),
10 parts by mass or more and 100 parts by mass or less of a glass filler (B), and
a polyethylene resin (C) having a weight-average molecular weight of 500,000 or less, wherein,
an amount of the polyethylene resign (c) having a weight-average molecular weight of 500,000 or less in a surface layer of the molded article is larger than an amount of the polyethylene resin (C) having a weight-average molecular weight of 500,00 or less in a layer surface deeper than 1,000 μm from the surface layer of the molded article as measured by cutting out the layer;
a tensile fracture stress of the molded article measured in accordance with ISO527-1 is 135 MPa or more;
a bending elastic modulus of the molded article measured in accordance with ISO178 is 7500 MPa or more; and
a value of (tensile fracture stress—65)(MPa)/glass filler ratio (mass %) is 2.90 or more.

3. The molded article according to claim 2 , wherein when the molded article is fractured by application of tensile force, the surface of the glass filler (B) protruding from a fractured surface of a fractured molded article is covered with a component comprising the polyacetal resin (A) having an average thickness of 0.2 μm or more and 3.0 μm or less.

4. The molded article according to claim 1 , wherein the polyethylene resin (C) having a weight-average molecular weight of 500,000 or less is present in an amount of 0.5 parts by mass or more and 8 parts by mass or less based on 100 parts by mass of the polyacetal resin (A).

5. The molded article according to claim 4 , wherein the polyethylene resin (C) having a weight-average molecular weight of 500,000 or less has a melting point of 115° C. or less.

6. The molded article according to claim 1 , wherein at least one acid is contained as a material having a function of modifying the surface of the glass filler (B).

7. The molded article according to claim 6 , wherein the acid is carboxylic acid.

8. The molded article according to claim 1 , wherein the polyacetal resin (A) contains a block component.

9. The molded article according to claim 8 , wherein the block component is a hydrogenated polybutadiene component.

10. A method for preparing the molded article according to claim 6 , comprising
a step of modifying a surface of the glass filter (B) with the material containing the at least one acid, and
a step of mixing the modified glass filler and the polyacetal resin (A).

11. The molded article according to claim 2 , wherein the polyethylene resin (C) having a weight-average molecular weight of 500,000 or less is present in an amount of 0.5 parts by mass or more and 8 parts by mass or less based on 100 parts by mass of the polyacetal resin (A).

12. The molded article according to claim 11 , wherein the polyethylene resin (C) having a weight-average molecular weight of 500,000 or less has a melting point of 115° C. or less.

13. The molded article according to claim 2 , wherein at least one acid is contained as a material having a function of modifying the surface of the glass filler (B).

14. The molded article according to claim 13 , wherein the acid is carboxylic acid.

15. The molded article according to claim 2 , wherein the polyacetal resin (A) contains a block component.

16. The molded article according to claim 15 , wherein the block component is a hydrogenated polybutadiene component.

17. A method for preparing the molded article according to claim 13 , comprising
a step of modifying a surface of the glass filler (B) with the material containing the at least one acid, and
a step of mixing the modified glass filler and the polyacetal resin (A).

18. The molded article according to claim 4 , wherein at least one acid is contained as a material having a function of modifying the surface of the glass filler (B).

19. The molded article according to claim 18 , wherein the polyacetal resin (A) contains a block component.

20. The molded article according to claim 6 , wherein the polyacetal resin (A) contains a block component.

Assignees

• Asahi Chemical Ind

Inventors

• Takahashi Yosuke
• Miyoshi Takaaki

Classifications

• C08K3/40

  Glass · CPC title

• C08G2/38

  Block or graft polymers prepared by polymerisation of aldehydes or ketones on to macromolecular compounds · CPC title

• C08K9/08

  Ingredients agglomerated by treatment with a binding agent · CPC title

• C08K7/14

  Glass · CPC title

• C08L23/06

  Polyethylene · CPC title