Pulverulent thermoplastic polymer blends

Patent metadata

Field	Value
Publication number	US-11820890-B2
Application number	US-202117220031-A
Country	US
Kind code	B2
Filing date	Apr 1, 2021
Priority date	Apr 1, 2021
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

The present disclosure is directed to pulverulent thermoplastic polymer blends comminuted to a particle size of less than 300 μm. The pulverulent thermoplastic polymer blends can include a first thermoplastic polyurethane and a second thermoplastic polyurethane at a weight ratio of from about 90:10 to about 30:70 first thermoplastic polyurethane to second thermoplastic polyurethane. The first thermoplastic polyurethane can include a reaction product of a first reaction mixture consisting of or consisting essentially of an aliphatic diisocyanate having a number average molecular weight of from 140 g/mol to 170 g/mol and an aliphatic diol having a number average molecular weight of from 62 g/mol to 120 g/mol. The second thermoplastic polyurethane can include a reaction product of a second reaction mixture comprising a polyisocyanate, an isocyanate-reactive component having a number average molecular weight of from 500 g/mol to 10,000 g/mol, and a chain extender having a number average molecular weight of from 60 g/mol to 450 g/mol.

First claim

What is claimed is:

1. A pulverulent thermoplastic polymer blend, comprising:
a comminuted thermoplastic polymer blend having a particle size of less than 300 μm, the thermoplastic polymer blend comprising a first thermoplastic polyurethane and a second thermoplastic polyurethane blended at a weight ratio of from 90:10 to 30:70 of first thermoplastic polyurethane to second thermoplastic polyurethane,
wherein the first thermoplastic polyurethane comprises a reaction product of a first reaction mixture consisting essentially of an aliphatic diisocyanate having a molecular weight of from 140 g/mol to 170 g/mol and an aliphatic diol having a molecular weight of from 62 g/mol to 120 g/mol, and
wherein the second thermoplastic polyurethane comprises a reaction product of a second reaction mixture comprising a polyisocyanate, an isocyanate-reactive component having a number average molecular weight of from 500 g/mol to 10,000 g/mol, and a chain extender having a number average molecular weight of from 60 g/mol to 450 g/mol, and wherein the second thermoplastic polyurethane has a hard-segment content from 60 wt. % to 85 wt %.

2. The pulverulent thermoplastic polymer blend of claim 1 , wherein the aliphatic diisocyanate comprises 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyantohexane, 1,5-diisocyanato-2-methylpentane, or a combination thereof.

3. The pulverulent thermoplastic polymer blend of claim 1 , wherein the aliphatic diol comprises 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butandiol, 1,4-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, or a combination thereof.

4. The pulverulent thermoplastic polymer blend of claim 1 , wherein the first thermoplastic polyurethane has a z-average molecular weight of from 100,000 g/mol to 900,000 g/mol.

5. The pulverulent thermoplastic polymer blend of claim 1 , wherein the first thermoplastic polyurethane has a melt volume-flow rate of at least 20 cm 3 /10 minutes at 200° C. and 8.7 kg based on ASTM D1238-10.

6. The pulverulent thermoplastic polymer blend of claim 1 , wherein the first thermoplastic polyurethane has a melting enthalpy of at least 60 J/g based on differential scanning calorimetry during a second heating trace from −25° C. to 250° C. at a heating rate of 20° C./min.

7. The pulverulent thermoplastic polymer blend of claim 1 , wherein the polyisocyanate comprises an aliphatic polyisocyanate.

8. The pulverulent thermoplastic polymer blend of claim 1 , wherein the polyisocyanate comprises an aromatic polyisocyanate.

9. The pulverulent thermoplastic polymer blend of claim 1 , wherein the isocyanate-reactive component comprises a polyether polyol.

10. The pulverulent thermoplastic polymer blend of claim 1 , wherein the isocyanate-reactive component comprises a polyester polyol.

11. The pulverulent thermoplastic polymer blend of claim 1 , wherein the second reaction mixture comprises no more than 40 wt % of the isocyanate-reactive component.

12. The pulverulent thermoplastic polymer blend of claim 1 , wherein the second thermoplastic polyurethane has a Shore D hardness of from 50D to 90D according to ASTM D2240-15e1.

13. The pulverulent thermoplastic polymer blend of claim 1 , wherein the pulverulent thermoplastic polymer blend has a melting temperature of less than or equal to 175° C. based on differential scanning calorimetry during a second heating trace from −25° C. to 250° C. at a heating rate of 20° C./min.

14. The pulverulent thermoplastic polymer blend of claim 1 , wherein the pulverulent thermoplastic polymer blend has a sintering window of at least 42° C. based on differential scanning calorimetry during a second heating trace from −25° C. to 250° C. at a heating rate of 20° C./min.

15. The pulverulent thermoplastic polymer blend of claim 1 , wherein the pulverulent thermoplastic polymer blend has a melting enthalpy of at least 10 J/g based on differential scanning calorimetry during a second heating trace from −25° C. to 250° C. at a heating rate of 20° C./min.

16. The pulverulent thermoplastic polymer blend of claim 1 , wherein the pulverulent thermoplastic polymer blend has a tensile modulus of at least 1 GPa based on ASTM D638-14 at 23° C.

17. The pulverulent thermoplastic polymer blend of claim 1 , further comprising a colorant, an antioxidant, an antiozonant, a stabilizer, a filler, a lubricant, an inhibitor, a electromagnetic radiation absorber, a reinforcing agent, or a combination thereof.

18. A method of manufacturing a pulverulent thermoplastic polymer blend, comprising:
comminuting a thermoplastic polymer blend to a particle size of less than 300 μm, the thermoplastic polymer blend comprising a first thermoplastic polyurethane and a second thermoplastic polyurethane blended at a weight ratio of from 90:10 to 30:70 first thermoplastic polyurethane to second thermoplastic polyurethane,
wherein the first thermoplastic polyurethane comprises a reaction product of a first reaction mixture consisting essentially of an aliphatic diisocyanate having a number average molecular weight of from 140 g/mol to 170 g/mol and an aliphatic diol having a number average molecular weight of from 62 g/mol to 120 g/mol, and
wherein the second thermoplastic polyurethane comprises a reaction product of second reaction mixture comprising a polyisocyanate, an isocyanate-reactive component having a number average molecular weight of from 500 g/mol to 10,000 g/mol, and a chain extender having a number average molecular weight of from 60 g/mol to 450 g/mol, and wherein the second thermoplastic polyurethane has a hard-segment content from 60 wt. % to 85 wt. %.

19. The method of claim 18 , wherein comminuting comprises cryogenic milling.

20. A three-dimensional printed article, comprising the pulverulent thermoplastic polymer blend of claim 1 fused together to form the three-dimensional printed article.

Assignees

• Stratasys Inc

Inventors

• Chen Liang
• Xu Chen
• Vescio Leslie J
• Lawrey Bruce D

Classifications

• C08L2205/02

  containing two or more polymers of the same C08L -group · CPC title

• B29B13/10

  by grinding, e.g. by triturating; by sieving; by filtering · CPC title

• B29B2009/125

  Micropellets, microgranules, microparticles · CPC title

• C08L75/04 Primary

  Polyurethanes · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title