Thermoplastic polyurethane particles having low impurity content and manufacturing method therefor

Patent metadata

Field	Value
Publication number	US-11118019-B2
Application number	US-201816491397-A
Country	US
Kind code	B2
Filing date	Mar 9, 2018
Priority date	Mar 9, 2017
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

The present invention provides thermoplastic polyurethane particles, which are formed in a continuous matrix phase from a thermoplastic polyurethane resin and have a particle diameter of 200-500 μm. In a differential scanning calorimetry (DSC) curve of the thermoplastic polyurethane particles, derived from the analysis of a temperature rise of 10° C./min by DSC, a peak of the cold crystallization temperature (T cc ) is shown at a temperature between the glass transition temperature (T g ) and the melting point (T m ). The thermoplastic polyurethane particles have a compression degree of 10-20%.

First claim

The invention claimed is:

1. Thermoplastic polyurethane particles which are formed as a continuous matrix from a thermoplastic polyurethane resin and have a particle diameter of 200 to 500 μM, wherein an impurity content of the thermoplastic polyurethane particles is 50 ppm or less.

2. The thermoplastic polyurethane particles according to claim 1 , wherein the thermoplastic polyurethane particles have a peak of cold crystallization temperature (T cc ) at a temperature between a glass transition temperature (T g ) and a melting point (T m ) in the differential scanning calorimetry (DSC) curve derived from temperature rise analysis of 10° C./min by the DSC.

3. The thermoplastic polyurethane particles according to claim 1 , wherein the thermoplastic polyurethane particles have an aspect ratio of 1.00 or more and less than 1.05, calculated by Formula 1 below, and a roundness of 0.95 to 1.00, calculated by Formula 2 below:
Aspect ratio=major axis/minor axis,  [Formula 1]

Roundness=4×area/(π×major axis{circumflex over ( )}2).  [Formula 2]

4. The thermoplastic polyurethane particles according to claim 1 , wherein the thermoplastic polyurethane particles have a compression degree of 10 to 20%, calculated by Formula 3 below:
Compression degree=(compressed bulk density-relaxed bulk density)/compressed bulk density×100.  [Formula 3]

5. The thermoplastic polyurethane particles according to claim 4 , wherein the thermoplastic polyurethane particles have a compressed bulk density of 0.45 to 0.5 g/cm 3 .

6. The thermoplastic polyurethane particles according to claim 1 , wherein the thermoplastic polyurethane particles have a flow time of 10 to 20 seconds.

Assignees

• Lg Hausys Ltd

Inventors

• Kim Min Gyung
• Kang Sung Yong
• Kang Kyoung Min
• Lee Hee-Jung
• Park Chang-Young
• Lim Jae Ho
• Choi Jun Ho
• Song Jae Han
• Go Yu Jin

Classifications

• B29B9/10

  by moulding the material, i.e. treating it in the molten state · CPC title

• C08L67/04

  Polyesters derived from hydroxycarboxylic acids, e.g. lactones (C08L67/06 takes precedence) · CPC title

• C08L23/0853

  Ethylene vinyl acetate copolymers · CPC title

• C08L23/06

  Polyethylene · CPC title

• C08L2203/30

  used for thermoforming · CPC title