Foamable resin composition for foam sheet, foam sheet, process for preparing particulate polylactic acid and process for preparing foam sheet

Patent metadata

Field	Value
Publication number	US-10508176-B2
Application number	US-201815874632-A
Country	US
Kind code	B2
Filing date	Jan 18, 2018
Priority date	Aug 29, 2013
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

Disclosed herein is a foamable resin composition for a foam sheet including polylactic acid resin particles, each of the particles having a particle size of about 1 μm to about 100 μm. A process for preparing a particulate polylactic acid resin includes: introducing a polylactic acid resin and then forming a molten polylactic acid spray solution; and injecting the molten polylactic acid spray solution by a melt spray method and simultaneously cooling the molten polylactic acid spray solution to obtain a particulate polylactic acid. In addition, disclosed herein is a process for preparing a foam sheet using the foamable resin composition for a foam sheet including a polylactic acid resin.

First claim

The invention claimed is:

1. A process for preparing a particulate polylactic acid resin comprising:
introducing a polylactic acid resin into an extruder;
forming a molten polylactic acid spray solution by transferring the polylactic acid resin to an spray nozzle and heating the polylactic acid resin in the spray nozzle; and
spraying the molten polylactic acid spray solution by a melt spray method and simultaneously cooling the molten polylactic acid spray solution to obtain a particulate polylactic acid,
wherein a voltage ranging from 2,000 V to 50,000 V is applied to the spray nozzle to carry out a melt electrostatic spray deposition.

2. The process according to claim 1 , wherein the molten polylactic acid spray solution is introduced into the spray nozzle together with an air and then discharged.

3. The process according to claim 2 , wherein a temperature of the air that is injected into the spray nozzle is of 300° C. to 500° C., a pressure of the air that is injected into the spray nozzle is of 100 psi to 1,000 psi, and an injection speed of the air that is injected into the spray nozzle is of 10 m/s to 50 m/s.

4. The process according to claim 1 , wherein a temperature of the spray nozzle is of 200° C. to 400° C.

5. The process according to claim 1 , wherein a pressure of the spray nozzle is of 10 psi to 1,000 psi.

6. The process according to claim 1 , wherein a diameter of the spray nozzle is of 0.5 mm to 3.0 mm.

7. The process according to claim 1 , wherein the molten polylactic acid spray solution comprises at least one additive selected from the group consisting of a lubricant, a plasticizer, and a combination thereof.

8. The process according to claim 1 , wherein the molten polylactic acid spray solution has a viscosity of 1,500 cps to 2,000 cps at 250° C.

9. The process according to claim 1 , wherein the particulate polylactic acid resin has an average particle size of 1 μm to 100 μm.

Assignees

• Lg Hausys Ltd

Inventors

• Shin Jun-Beom
• Kang Sung-Yong
• Lee Min-Hee
• Kwon Hea-Won
• Kang Kyoung-Min

Classifications

• B01J2/02

  by dividing the liquid material into drops, e.g. by spraying, and solidifying the drops · CPC title

• B05B5/001

  incorporating means for heating or cooling, e.g. the material to be sprayed · CPC title

• B29K2067/046

  PLA, i.e. polylactic acid or polylactide · CPC title

• C08J3/122

  Pulverisation by spraying · CPC title

• B29C48/0021

  combined with joining, lining or laminating · CPC title