In-mold foam molded body comprising polypropylene resin foam particles and method for producing same

Patent metadata

Field	Value
Publication number	US-9611369-B2
Application number	US-201314384617-A
Country	US
Kind code	B2
Filing date	Mar 13, 2013
Priority date	Mar 14, 2012
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

An in-mold foaming molded product having a thin wall part of the present invention contains expanded polypropylene resin particles. The expanded polypropylene resin particles include a polypropylene resin composition that contains an aliphatic diethanolamine fatty acid ester and an aliphatic diethanolamine in a total amount of not less than 0.1 part by weight but not greater than 5 parts by weight with respect to 100 parts by weight of polypropylene resin.

First claim

The invention claimed is:

1. An in-mold foaming molded product containing a thin wall part, each of the in-mold foaming molded product and the thin wall part comprising expanded polypropylene resin particles,
the expanded polypropylene resin particles including a polypropylene resin composition that contains an aliphatic diethanolamine fatty acid ester and an aliphatic diethanolamine in a total amount of not less than 0.25 parts by weight but not greater than 5 parts by weight with respect to 100 parts by weight of polypropylene resin, wherein
a weight proportion of the aliphatic diethanolamine is not less than 0.1 parts by weight but not greater than 3 parts by weight with respect to 100 parts by weight of polypropylene resin, and
a weight proportion of the aliphatic diethanolamine fatty acid ester is not less than 0.15 parts by weight but not greater than 2 parts by weight with respect to 100 parts by weight of polypropylene resin.

2. The in-mold foaming molded product as set forth in claim 1 , wherein a weight proportion of the aliphatic diethanolamine fatty acid ester is not less than 5 weight % but not greater than 95 weight % with respect to 100 weight % of a total weight of the aliphatic diethanolamine fatty acid ester and the aliphatic diethanolamine.

3. The in-mold foaming molded product as set forth in claim 1 , wherein the aliphatic diethanolamine fatty acid ester is a compound represented by General Formula (1), and the aliphatic diethanolamine is a compound represented by General Formula (2),

where R 1 is a C12 to C24 alkyl group, R 2 is a C11 to C23 alkyl group, and R 1 and R 2 are optionally identical to or different from each other,

where R 3 is a C12 to C24 alkyl group.

4. The in-mold foaming molded product as set forth in claim 3 , wherein the aliphatic diethanolamine fatty acid ester is stearyl diethanolamine monostearic acid ester, and the aliphatic diethanolamine is stearyl diethanolamine.

5. The in-mold foaming molded product as set forth in claim 1 , wherein the polypropylene resin composition further contains an aliphatic alcohol in an amount of not less than 0.001 part by weight but not greater than 2 parts by weight with respect to 100 parts by weight of the polypropylene resin.

6. The in-mold foaming molded product as set forth in claim 5 , wherein the aliphatic alcohol is a compound represented by General Formula (3),
R 4 —OH  General Formula (3)

where R 4 is a C12 to C24 alkyl group.

7. The in-mold foaming molded product as set forth in claim 1 , wherein a shortest distance between one point of one of a pair of surfaces and the other of the pair of surfaces which face each other on at least one portion of the thin wall part of the in-mold foaming molded product is a distance of not less than one expanded polypropylene resin particle but not more than three expanded polypropylene resin particles.

8. The in-mold foaming molded product as set forth in claim 1 , wherein a shortest distance between one point of one of a pair of surfaces and the other of the pair of surfaces which face each other on at least one portion of the thin wall part of the in-mold foaming molded product is a distance of not less than one expanded polypropylene resin particle but not more than two expanded polypropylene resin particles.

9. The in-mold foaming molded product as set forth in claim 1 , wherein the in-mold foaming molded product having the thin wall part is configured to house an article in each section partitioned by a rib or ribs which is/are the thin wall part.

10. A method of producing an in-mold foaming molded product having a thin wall part,
the method comprising the steps of:
filling a mold with expanded polypropylene resin particles; and
heating the expanded polypropylene resin particles in the mold,
the expanded polypropylene resin particles including a polypropylene resin composition that contains an aliphatic diethanolamine fatty acid ester and an aliphatic diethanolamine in a total amount of not less than 0.25 parts by weight but not greater than 5 parts by weight with respect to 100 parts by weight of polypropylene resin, wherein
a weight proportion of the aliphatic diethanolamine is not less than 0.1 parts by weight but not greater than 3 parts by weight with respect to 100 parts by weight of polypropylene resin, and
a weight proportion of the aliphatic diethanolamine fatty acid ester is not less than 0.15 parts by weight but not greater than 2 parts by weight with respect to 100 parts by weight of polypropylene resin.

11. The method as set forth in claim 10 , wherein the polypropylene resin composition further contains an aliphatic alcohol in an amount of not less than 0.001 part by weight but not greater than 2 parts by weight with respect to 100 parts by weight of the polypropylene resin.

Assignees

• Kaneka Corp

Inventors

• Sato Keishi
• Yoshida Toru

Classifications

• C08J2323/12

  Polypropene · CPC title

• C08J9/0023

  containing oxygen · CPC title

• B29K2023/12

  PP, i.e. polypropylene · CPC title

• C08J9/18

  by impregnating polymer particles with the blowing agent · CPC title

• B29C44/02

  for articles of definite length, i.e. discrete articles · CPC title