Thermoplastic Polyurethane Particles And Manufacturing Method Therefor

Patent metadata

Field	Value
Publication number	US-2020032005-A1
Application number	US-201816491397-A
Country	US
Kind code	A1
Filing date	Mar 9, 2018
Priority date	Mar 9, 2017
Publication date	Jan 30, 2020
Grant date	—

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 (Tcc) is shown at a temperature between the glass transition temperature (Tg) and the melting point (Tm). The thermoplastic polyurethane particles have a compression degree of 10-20%.

First claim

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.

2 . The thermoplastic polyurethane particles according to claim 1 , wherein the impurity content of the thermoplastic polyurethane particles is 50 ppm or less.

3 . 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 the glass transition temperature (T g ) and the melting point (T m ) in the differential scanning calorimetry (DSC) curve derived from temperature rise analysis of 10° C./min by the DSC.

4 . 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]

5 . 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]

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

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

8 . A method for manufacturing the thermoplastic polyurethane particles of claim 1 comprising the steps of:
(1) supplying a thermoplastic polyurethane resin to an extruder and extruding it;
(2) supplying the extruded thermoplastic polyurethane resin and air to the nozzle, bringing the thermoplastic polyurethane resin into contact with air to granulate the thermoplastic polyurethane resin, and then discharging granulated thermoplastic polyurethane resins; and
(3) supplying the discharged thermoplastic polyurethane particles to a cooling unit to cool the thermoplastic polyurethane particles, and then collecting cooled thermoplastic polyurethane particles.

9 . The method for manufacturing the thermoplastic polyurethane particles according to claim 8 , wherein the extruded thermoplastic polyurethane resin supplied to the nozzle in step (2) has a melt viscosity of 0.5 to 20 Pa·s.

10 . The method for manufacturing the thermoplastic polyurethane particles according to claim 8 , wherein in step (2), the air is supplied to the center and the outer portion based on the cross section of the nozzle, and the extruded thermoplastic polyurethane resin is supplied between the center and the outer portion to which the air is supplied.

11 . The method for manufacturing the thermoplastic polyurethane particles according to claim 10 , wherein in step (2), the ratio of the cross-sectional areas of the air supplied to the outer portion and the extruded thermoplastic polyurethane resin supplied between the central portion and the outer portion to which the air is supplied is 2:1 to 4:1 based on the cross section at the outlet of the nozzle.

12 . The method for manufacturing the thermoplastic polyurethane particles according to claim 8 , wherein in step (2), the inside of the nozzle is maintained at 250 to 350° C.

13 . The method for manufacturing the thermoplastic polyurethane particles according to claim 12 , wherein in step (2), the outlet of the nozzle is maintained at a temperature calculated by Formula 4 below:
Outlet temperature=glass transition temperature ( T g )+(decomposition temperature ( T d )−glass transition temperature ( T g ))× A,   [Formula 4]
wherein the glass transition temperature and the decomposition temperature are values for thermoplastic polyurethane, and A is 0.5 to 1.5.

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

• C08G63/06

  derived from hydroxycarboxylic acids · CPC title

• C08J2367/04

  Polyesters derived from hydroxy carboxylic acids, e.g. lactones (C08J2367/06 takes precedence) · CPC title

• C08J2375/04

  Polyurethanes · CPC title

• C08J3/12 Primary

  Powdering or granulating · CPC title

• C08L67/04

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