Polyacetal Resin Composition and Molded Article Thereof

Patent metadata

Field	Value
Publication number	US-2017145207-A1
Application number	US-201515300064-A
Country	US
Kind code	A1
Filing date	Mar 27, 2015
Priority date	Mar 28, 2014
Publication date	May 25, 2017
Grant date	—

Abstract

An object of the invention is to provide a resin composition, from which a molded article having high durability, sliding property and wear resistance can be produced with a high productivity.
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

1 . 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) wherein,
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.

2 . 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) wherein,
a tensile fracture stress of a molded article obtained by molding the polyacetal resin composition and 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 polyacetal resin composition according to claim 2 , wherein when the 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.

4 . The polyacetal resin composition according to claim 1 , further containing a polyethylene resin (C) having a weight-average molecular weight of 500,000 or less 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 polyacetal resin composition 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 polyacetal resin composition 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 polyacetal resin composition according to claim 6 , wherein the acid is carboxylic acid.

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

9 . The polyacetal resin composition according to claim 8 , wherein the block component is a hydrogenated polybutadiene component.

10 . A molded article obtained by molding the polyacetal resin composition according to claim 1 .

11 . The molded article according to claim 10 , wherein a polyethylene resin (C) having a weight-average molecular weight of 500,000 or less is contained; 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.

12 . A method for preparing the polyacetal resin composition according to claim 1 , comprising
a step of modifying a surface of the glass filler (B) with a substance containing at least one acid and having a function of modifying the surface of the glass filler (B), and a step of mixing the glass filler modified and the polyacetal resin (A).

13 . The polyacetal resin composition according to claim 2 , further containing a polyethylene resin (C) having a weight-average molecular weight of 500,000 or less 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).

14 . The polyacetal resin composition according to claim 13 , 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.

15 . The polyacetal resin composition 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).

16 . The polyacetal resin composition according to claim 15 , wherein the acid is carboxylic acid.

17 . The polyacetal resin composition according to claim 2 , wherein the polyacetal resin (A) contains a block component.

18 . The polyacetal resin composition according to claim 17 , wherein the block component is a hydrogenated polybutadiene component.

19 . A molded article obtained by molding the polyacetal resin composition according to claim 2 .

20 . The molded article according to claim 19 , wherein a polyethylene resin (C) having a weight-average molecular weight of 500,000 or less is contained; 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.

21 . A method for preparing the polyacetal resin composition according to claim 2 , comprising
a step of modifying a surface of the glass filler (B) with a substance containing at least one acid and having a function of modifying the surface of the glass filler (B), and a step of mixing the glass filler modified and the polyacetal resin (A).

22 . The polyacetal resin composition 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).

23 . The polyacetal resin composition according to claim 22 , wherein the polyacetal resin (A) contains a block component.

24 . The polyacetal resin composition according to claim 6 , wherein the polyacetal resin (A) contains a block component.

Assignees

• Asahi Chemical Ind

Inventors

• Takahashi Yosuke
• Miyoshi Takaaki

Classifications

• C08L59/02 Primary

  Polyacetals containing polyoxymethylene sequences only · CPC title

• C08K9/08

  Ingredients agglomerated by treatment with a binding agent · CPC title

• C08K3/40

  Glass · CPC title

• C08L87/005

  Block or graft polymers not provided for in groups C08L1/00 - C08L85/04 · CPC title

• C08K7/14

  Glass · CPC title