Foam sheet using cross-linked polylactic acid, and preparation method thereof

Patent metadata

Field	Value
Publication number	US-9512265-B2
Application number	US-201214360149-A
Country	US
Kind code	B2
Filing date	Dec 6, 2012
Priority date	Dec 13, 2011
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

The present invention relates to a foam sheet using cross-linked polylactic acid and method of manufacturing the same, and more particularly a foam sheet using cross-linked polylactic acid and method of manufacturing the same with not only excellent waterproofing and workability but also relatively high foaming ratio and a uniform closed foam cell structure, by producing cross-linked polylactic acid resin in a fixed condition using composites comprising polylactic acid, cross linking agents, and/or co-crosslinking agents, and then forming a sheet shape in a fixed condition using composites comprising the cross-linked polylactic acid and foaming agents, and then foaming at relatively high temperature conditions.

First claim

The invention claimed is:

1. A foam sheet, comprising: one or more resin layers comprising a non-crystalline polylactic acid; and forming cells,
wherein the non-crystalline polylactic acid is cross-linked, and each of the foaming cells has a closed structure,
wherein each of the one or more resin layers is formed from a biodegradable resin composite comprising 0.001˜10 parts by weight of a cross linking agent, 0.1˜10 parts by weight of a foaming agent, per 100 parts by weight of the non-crystalline polylactic acid,
wherein the cross linking agent is one or more of organic peroxides selected from perbutyl peroxide, and t-butylethylhexylmonoperoxy carbonate,
wherein the biodegradable resin composite further comprises a plasticizer, a co-foaming agent and a co-crosslinking agent,
wherein the content of the plasticizer is 40˜100 parts by weight per 100 parts by weight of the non-crystalline polylactic acid,
wherein the co-foaming agent comprises one or more elements selected from zincneodecarbonate, potassiumneodecarbonate, and zinc 2-ethylhexanoate,
wherein the content of the co-foaming agent is 10.0 or less parts by weight per 100 parts by weight of the non-crystalline polylactic acid,
wherein the content of the co-crosslinking agent is 1.0 or less parts by weight per 100 parts by weight of the non-crystalline polylactic acid, and
wherein the co-crosslinking agent comprises triallyl isocyanurate(TAIC).

2. The foam sheet according to claim 1 , wherein the non-crystalline polylactic acid comprises one or more polymers selected from L-polylactide, D-polylactide, and L,D-polylactide.

3. The foam sheet according to claim 1 , wherein the biodegradable resin composite further comprises an inorganic filler.

4. The A foam sheet according to claim 3 , wherein the content of the inorganic filler is 300 or less parts by weight per 100 parts by weight of the non-crystalline polylactic acid.

5. A method for manufacturing a foam sheet comprising: one or more resin layers comprising a non-crystalline polylactic acid; and forming cells,
wherein the non-crystalline polylactic acid is cross-linked, and each of the foaming cells has a closed structure,
wherein each of the one or more resin layers is formed from a biodegradable resin composite comprising 0.001˜10 parts by weight of a cross linking agent, 0.1˜10 parts by weight of a foaming agent, per 100 parts by weight of the non-crystalline polylactic acid,
wherein the cross linking agent is one or more of organic peroxides selected from perbutyl peroxide, and t-butylethylhexylmonoperoxy carbonate,
wherein the biodegradable resin composite further comprises a plasticizer, a co-foaming agent and a co-crosslinking agent,
wherein the content of the plasticizer is 40˜100 parts by weight per 100 parts by weight of the non-crystalline polylactic acid,
wherein the co-foaming agent comprises one or more elements selected from zincneodecarbonate, potassiumneodecarbonate, and zinc 2-ethylhexanoate,
wherein the content of the co-foaming agent is 10.0 or less parts by weight per 100 parts by weight of the non-crystalline polylactic acid,
wherein the content of the co-crosslinking agent is 1.0 or less parts by weight per 100 parts by weight of the non-crystalline polylactic acid, and
wherein the co-crosslinking agent comprises triallyl isocyanurate(TAIC), the method comprising:
cross linking by raising temperature of a first composite comprising 100 parts by weight of the non-crystalline polylactic acid, 0.001˜10 parts by weight of the cross linking agent and 1.0 or less parts by weight of the co-crosslinking agent;
producing a sheet by extruding or calendering a second composite obtained by further adding 0.1˜10 parts by weight of the foaming agent, 10.0 or less parts by weight of the co-foaming agent, and 40˜100 parts by weight of the plasticizer, per 100 parts by weight of the non-crystalline polylactic acid to the cross-linked first composite; and
foaming by passing the sheet through an oven.

6. The method for manufacturing foam sheet according claim 5 , wherein the non-crystalline polylactic acid comprises one or more polymers selected from L-polylactide, D-polylactide, and L,D-polylactide.

7. The method for manufacturing a foam sheet according claim 5 , wherein the cross linking agent further comprises one or more organic peroxides selected from dicumyl peroxide, dimethyl di-t-butylperoxy hexane, and 1,1,-di(t-butylperoxy)-3,3,5-trimethylcyclohexane.

8. The method for manufacturing a foam sheet according claim 5 , wherein the foaming agent is one or more elements selected from azodicarbonamide, p,p′-oxybisbenzenesulfonylhydrazide, p-toluenesulfonylhydrazide, and benzenesulfonylhydarazide.

9. The method for manufacturing a foam sheet according claim 5 , wherein the second composite further comprises an inorganic filler.

10. The method for manufacturing a foam sheet according claim 9 , wherein the content of the inorganic filler is 300 or less parts by weight per 100 parts by weight of the non-crystalline polylactic acid.

Assignees

• Lg Hausys Ltd

Inventors

• Kang Chang Won
• Huang Cheng Zhe
• Son Ji Hyang

Classifications

• C08J2300/16

  Biodegradable polymers · CPC title

• B32B2307/73

  Hydrophobic · CPC title

• C08J2201/026

  Crosslinking before of after foaming · CPC title

• C08J9/0028

  containing nitrogen · CPC title

• C08J2205/052

  Closed cells, i.e. more than 50% of the pores are closed · CPC title