Propylene-based resin foam particle and foam particle molded body

Patent metadata

Field	Value
Publication number	US-2016333161-A1
Application number	US-201415111760-A
Country	US
Kind code	A1
Filing date	Dec 24, 2014
Priority date	Jan 17, 2014
Publication date	Nov 17, 2016
Grant date	—

Abstract

The present invention is concerned with expanded propylene resin beads including a core layer being in a foamed state and constituted of a propylene-based resin composition (a) and a cover layer constituted of an olefin-based resin (b), the propylene-based resin composition (a) satisfying the following (i) and (ii), and the olefin-based resin (b) satisfying the following (iii) or (iv).
(i) A mixture of 75% by weight to 98% by weight of a propylene-based resin (a1) having a melting point of 100° C. to 140° C. and 25% by weight to 2% by weight of a propylene-based resin (a2) having a melting point of 140° C. to 165° C. (ii) A difference between the melting point of the resin (a2) and the melting point of the resin (a1) is 15° C. or more. (iii) A crystalline olefin-based resin having a melting point TmB that is lower than a melting point TmA of the composition (a) and having a relation of 0° C.<[TmA−TmB]≦80° C. (iv) A non-crystalline olefin-based resin having a softening point TsB that is lower than TmA and having a relation of 0° C.<[TmA−TsB]≦100° C.

First claim

1 . Expanded propylene resin beads comprising a core layer being in a foamed state and comprising a propylene-based resin composition (a) and a cover layer comprising an olefin-based resin (b),
the propylene-based resin composition (a) satisfying the following (i) and (ii), and the olefin-based resin (b) satisfying the following (iii) or (iv): (i) the propylene-based resin composition (a) is a mixture of 75% by weight to 98% by weight of a propylene-based resin (a1) having a melting point of 100° C. to 140° C. and 25% by weight to 2% by weight of a propylene-based resin (a2) having a melting point of 140° C. to 165° C., provided that a sum total of the propylene-based resin (a1) and the propylene-based resin (a2) is 100% by weight; (ii) a difference between the melting point of the propylene-based resin (a2) and the melting point of the propylene-based resin (a1) [(melting point of a2)−(melting point of a1)] is 15° C. or more; (iii) the olefin-based resin (b) is a crystalline olefin-based resin having a melting point (TmB) that is lower than a melting point (TmA) of the propylene-based resin composition (a), with a difference between the melting point (TmA) and the melting point (TmB) [TmA−TmB] being more than 0° C. and 80° C. or less; and (iv) the olefin-based resin (b) is a non-crystalline olefin-based resin having a softening point (TsB) that is lower than the melting point (TmA) of the propylene-based resin composition (a), with a difference between the melting point (TmA) and the softening point (TsB) [TmA−TsB] being more than 0° C. and 100° C. or less.

2 . The expanded propylene resin beads according to claim 1 , wherein in a first time DSC curve obtained by the heat flux differential scanning calorimetry when heated from ambient temperature to 200° C. at a heating rate of 2° C./min, the expanded propylene resin beads show a main endothermic peak in which a peak top temperature of the endothermic peak is 100° C. to 140° C. and one endothermic peak on the high temperature side of the main endothermic peak appears, and the main endothermic peak calorific value of 70% to 95% relative to a total endothermic peak calorific value.

3 . The expanded propylene resin beads according to claim 1 , wherein in the item (ii), the difference in melting point between the propylene-based resin (a2) and the propylene-based resin (a1) [(melting point of a2)−(melting point of a1)] is 15 to 25° C.

4 . The expanded propylene resin beads according to claim 1 , wherein the propylene-based resin (a1) or the propylene-based resin (a1) and the propylene-based resin (a2) are a propylene-based resin obtained through polymerization in the presence of a metallocene-based polymerization catalyst.

5 . The expanded propylene resin beads according to claim 1 , wherein the propylene-based resin (a1) is a propylene-based random copolymer obtained through polymerization in the presence of a metallocene-based polymerization catalyst, and the propylene-based resin (a2) is a propylene-based copolymer.

6 . The expanded propylene resin beads according to claim 1 , wherein the propylene-based resin composition (a) has a flexural modulus of 800 MPa to 1,200 MPa.

7 . The expanded propylene resin beads according to claim 1 , wherein the propylene-based resin composition (a) has a content of the propylene-based resin (a1) of more than 90% by weight and 98% by weight or less and a content of the propylene-based resin (a2) of 2% by weight or more and less than 10% by weight.

8 . The expanded propylene resin beads according to claim 1 , wherein the olefin-based resin (b) is a propylene-based resin obtained through polymerization in the presence of a metallocene-based polymerization catalyst.

9 . The expanded propylene resin beads according to claim 1 , wherein the olefin-based resin (b) is an ethylene-based resin obtained through polymerization in the presence of a metallocene-based polymerization catalyst.

10 . An expanded propylene resin beads molded article obtained through in-mold molding of the expanded propylene resin beads according to claim 1 .

Assignees

• Jsp Corp

Inventors

• Ono Michitoshi
• Kitahara Taizo
• Tsurugai Kazuo

Classifications

• C08J9/22

  After-treatment of expandable particles; Forming foamed products · CPC title

• C08J9/224

  Surface treatment · CPC title

• C08J9/0061

  characterized by the use of several polymeric components · CPC title

• C08J9/232

  by sintering expandable particles · CPC title

• C08J2423/16

  Ethene-propene or ethene-propene-diene copolymers · CPC title