Blow-molded foam and method of forming the same

Patent metadata

Field	Value
Publication number	US-2016237232-A1
Application number	US-201415027581-A
Country	US
Kind code	A1
Filing date	Oct 9, 2014
Priority date	Oct 10, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

A blow-molded foam is provided by foaming and blow-molding the resin material including a polyethylene resin. The foamed resin includes the antioxidant by 300 ppm or more in total. The antioxidant is preferably the combination of a phosphorus antioxidant and a phenolic antioxidant. The optimum amount of phosphorus antioxidant to be included is 250 ppm to 3000 ppm, and that of phenolic antioxidant is 250 ppm to 750 ppm. In the manufacture, the collected resin material and the resin including 300 ppm or more of the antioxidant are melted and kneaded and the foaming agent is mixed thereto to provide the foamed resin, and the foamed resin is blow-molded.

First claim

1 . A blow-molded foam formed by foaming and blow-molding a resin material including a polyethylene resin, wherein
the foamed resin includes an antioxidant, and the antioxidant is included by 300 ppm or more in total.

2 . The blow-molded foam according to claim 1 , wherein the antioxidant is included by 500 ppm or more in total.

3 . The blow-molded foam according to claim 1 , wherein the antioxidant includes a first antioxidant that operates to capture a radical and a second antioxidant that decomposes a peroxide.

4 . The blow-molded foam according to claim 3 , wherein the first antioxidant is a phenolic antioxidant and the second antioxidant is a phosphorus antioxidant.

5 . The blow-molded foam according to claim 4 , wherein the phenolic antioxidant is included by 250 to 750 ppm and the phosphorus antioxidant is included by 250 to 3000 ppm.

6 . The blow-molded foam according to claim 4 , wherein the phenolic antioxidant and the phosphorus antioxidant are low-molecular-weight antioxidant.

7 . The blow-molded foam according to claim 1 , wherein a change ratio of a melt flow rate of the resin material including the antioxidant after three thermal histories relative to a melt flow rate thereof after one thermal history is 5% or less.

8 . The blow-molded foam according to claim 1 , wherein a change ratio of a melt tensile force MT of the resin material including the antioxidant after three thermal histories relative to a melt tensile force MT thereof after one thermal history is −5% to 0%.

9 . The blow-molded foam according to claim 8 , wherein a value of the melt tensile force MT of the resin material including the antioxidant after one thermal history and the value thereof after three thermal histories are both 180 mN±10 mN.

10 . The blow-molded foam according to claim 1 , wherein the blow-molded foam is a climate control duct for vehicles.

11 . A method of forming a blow-molded foam by foaming and blow-molding a resin material including a polyethylene resin, the method comprising:
leaving an antioxidant, of which amount is determined so that the antioxidant is included by 300 ppm or more in a blow-molded foam formed by blow-molding, as an unused resin; mixing the unused resin with a collected resin material and melting and kneading the mixture; mixing a foaming agent to the mixture to prepare a foamed resin; and blow-molding the foamed resin.

12 . The method of forming a blow-molded foam according to claim 11 , wherein the antioxidant includes a first antioxidant that operates to capture a radical and a second antioxidant that decomposes a peroxide.

13 . The method of forming a blow-molded foam according to claim 12 , wherein the first antioxidant is a phenolic antioxidant and the second antioxidant is a phosphorus antioxidant.

14 . The method of forming a blow-molded foam according to claim 13 , wherein the phenolic antioxidant is included by 250 to 750 ppm and the phosphorus antioxidant is included by 250 to 3000 ppm.

15 . The blow-molded foam according to claim 11 , wherein the collected resin material is included by 70% or more relative to the weight of the foamed resin.

Assignees

• Kyoraku Co Ltd

Inventors

• Sano Takeru

Classifications

• B29K2105/04

  cellular or porous · CPC title

• B29L2023/22

  Tubes or pipes, i.e. rigid (bent tubes not for use as pipe couplings B29L2023/004) · CPC title

• B29L2031/30

  Vehicles, e.g. ships or aircraft, or body parts thereof {(vanes or blades B29L2031/08, air bags B29L2022/027)} · CPC title

• B29K2023/06

  PE, i.e. polyethylene · CPC title

• B29L2031/3032

  Air inlets · CPC title