Foam Body, Method for Producing Foam Body, and Laminate

Patent metadata

Field	Value
Publication number	US-2025034389-A1
Application number	US-202418782483-A
Country	US
Kind code	A1
Filing date	Jul 24, 2024
Priority date	Jul 25, 2023
Publication date	Jan 30, 2025
Grant date	—

Abstract

The present disclosure provides a foam body good in a molded appearance, a cushioning property, and wear resistance, and excellent also in property balance. The foam body is a foam body of a hydrogenated block copolymer composition containing a hydrogenated block copolymer (I), an olefin-based resin (II), a thermoplastic resin (III), and a softener (IV), and includes a foam core layer and a non-foam skin layer, the foam core layer has a thickness of 300 μm or more, the foaming ratio is 1.2-fold or more, a content of a polymer block (a) principally containing a vinyl aromatic monomer unit in the hydrogenated block copolymer (I) is 10 to 40% by mass, the hydrogenated block copolymer (I) contains a hydrogenated copolymer block (b) containing a vinyl aromatic monomer unit and a conjugated diene monomer unit.

First claim

1 . A foam body of a hydrogenated block copolymer composition, comprising:
a hydrogenated block copolymer (I); an olefin-based resin (II); a thermoplastic resin (III); and a softener (IV), wherein the foam body comprises a foam core layer and a non-foam skin layer adjacent to each other, the foam core layer has a thickness of 300 μm or more, the foam body has a foaming ratio of 1.2-fold or more, and the foam body satisfies the following conditions (1) to (5): <Condition (1)> the hydrogenated block copolymer (I) is a hydrogenated product of a block copolymer containing a vinyl aromatic monomer unit, and a conjugated monomer unit; <Condition (2)> the hydrogenated block copolymer (I) contains at least one polymer block (a) principally containing a vinyl aromatic monomer unit, and a content of the polymer block (a) principally containing a vinyl aromatic monomer unit in the hydrogenated block copolymer (I) is 10% by mass or more and 40% by mass or less; <Condition (3)> the hydrogenated block copolymer (I) contains at least one hydrogenated copolymer block (b) containing a vinyl aromatic monomer unit, and a conjugated diene monomer unit, and a content of the vinyl aromatic monomer unit in the hydrogenated copolymer block (b) is 5% by mass or more and 79% by mass or less; <Condition (4)> the hydrogenated block copolymer composition has a value of 15 seconds hardness measured with a type A durometer in accordance with JIS K6253 of 85 or less; and <Condition (5)> the hydrogenated block copolymer composition has an MFR value measured under conditions of a temperature of 230° C. and a load of 2.16 kg in accordance with JIS K7210 of 40 or more.

2 . The foam body according to claim 1 ,
wherein a content of the vinyl aromatic monomer unit in the hydrogenated copolymer block (b) is 15% by mass or more and 79% by mass or less.

3 . The foam body according to claim 1 ,
wherein the hydrogenated block copolymer (I) comprises at least one polymer block (a) principally containing a vinyl aromatic monomer unit, and the content of the polymer block (a) principally containing a vinyl aromatic monomer unit in the hydrogenated block copolymer (I) is 15% by mass or more and 35% by mass or less.

4 . The foam body according to claim 1 ,
wherein the hydrogenated block copolymer composition has a value of 15 seconds hardness measured with a type A durometer in accordance with JIS K6253 of 30 or more and 75 or less.

5 . The foam body according to claim 1 ,
wherein the hydrogenated block copolymer composition has an MFR value measured under conditions of a temperature of 230° C. and a load of 2.16 kg in accordance with JIS K7210 of 100 or more and 1,000 or less.

6 . The foam body according to claim 1 ,
wherein the non-foam skin layer has a thickness of 10 μm to 500 μm.

7 . The foam body according to claim 1 ,
wherein the foam core layer has a thickness of 1,000 μm to 20,000 μm.

8 . The foam body according to claim 1 ,
wherein the olefin-based resin (II) comprises at least one polypropylene-based resin.

9 . The foam body according to claim 1 , wherein the foaming ratio is 1.5-fold or more.

10 . The foam body according to claim 1 ,
wherein the foam body is for use in a vehicle component selected from the group consisting of a side mall, a grommet, a shift knob, a weather strip, a window frame and a sealing material thereof, a dashboard, an assist grip, a steering wheel, a shift lever, a console, an arm rest, a head rest, and a door panel.

11 . A method for producing the foam body according to claim 1 , the method comprising:
a step of adding a foaming agent to the hydrogenated block copolymer composition, and injecting the resultant to fill a cavity, which is formed in a mold of an injection molding machine, and has a space volume adjustable with a movable core; and a step of increasing the space volume of the cavity with the movable core to perform foam molding.

12 . A laminate comprising:
a layer containing the foam body according to claim 1 ; and a layer containing a base resin.

13 . The laminate according to claim 12 ,
wherein the layer containing the base resin and the layer containing the foam body are in direct contact with each other without an adhesive layer therebetween.

Assignees

• Asahi Chemical Ind

Inventors

• Sonoda Yuya
• Nakagawa Atsushi

Classifications

• B29L2031/3005

  Body finishings · CPC title

• B29K2096/04

  Block polymers · CPC title

• B29C44/0415

  by regulating the pressure of the material during or after filling of the mould, e.g. by local venting · CPC title

• B29C44/083

  Increasing the size of the cavity after a first part has foamed, e.g. substituting one mould part with another · CPC title

• B29C44/586

  with a cavity increasing in size during foaming · CPC title