Fiber reinforced TPU composites

Patent metadata

Field	Value
Publication number	US-9068076-B2
Application number	US-99199209-A
Country	US
Kind code	B2
Filing date	May 20, 2009
Priority date	May 23, 2008
Publication date	Jun 30, 2015
Grant date	Jun 30, 2015

Abstract

A catalyst masterbatch is disclosed, which when used with a rigid TPU polymer, will cause the rigid TPU to depolymerize during melt processing and repolymerize as the melt is being cooled. This feature is of particular interest in a pultrusion process to create TPU/fiber composites. The catalyst masterbatch contains a relative soft TPU polymer where the catalyst has been swelled or absorbed into the soft TPU polymer. A carrier, such as a plasticizer, can be used to aid the transport of the catalyst into the soft TPU polymer. The catalyst masterbatch is used as an additive to the rigid TPU in a pultrusion process to make the composites. The catalyst masterbatch can also be used in non-fiber reinforced rigid TPU compositions to increase the Mw of melt processed rigid TPU.

First claim

What is claimed is:

1. A process for making a thermoplastic polyurethane composition comprising the steps of:
(a) providing a first rigid thermoplastic polyurethane polymer, said first rigid thermoplastic polyurethane polymer being made by reacting a polyisocyanate with a chain extender, without any polyol being present; and
(b) providing a second thermoplastic polyurethane polymer;
(c) absorbing at least one hydrolytically and thermally stable catalyst into said second thermoplastic polyurethane polymer after polymerization of said second thermoplastic polyurethane polymer, said catalyst being capable of depolymerizing said first rigid thermoplastic polyurethane at melt processing temperatures and repolymerizing said first rigid thermoplastic polyurethane as said first rigid thermoplastic polyurethane is cooled below melt processing temperatures, wherein said catalyst comprises dimethyl tin dilauryl mercaptide, dibutyl tin dilauryl mercaptide, or dioctyl tin dilauryl mercaptide;
(d) blending said first rigid thermoplastic polyurethane polymer and said second thermoplastic polyurethane polymer to form a thermoplastic polyurethane polymer blend;
(e) melting said thermoplastic polyurethane blend, wherein while the thermoplastic polyurethane blend is melting, said catalyst depolymerizes said first thermoplastic polyurethane polymer; and
(f) cooling said thermoplastic polyurethane blend, wherein while the thermoplastic polyurethane blend is cooling, said catalyst repolymerizes said first thermoplastic polyurethane polymer.

2. The process of claim 1 , wherein said first rigid thermoplastic polyurethane polymer is an engineering grade thermoplastic polyurethane having a hardness greater than 60 Shore D.

3. The process of claim 2 , wherein said first rigid thermoplastic polyurethane polymer has a hardness greater than 80 Shore D.

4. The process of claim 3 , wherein said first rigid thermoplastic polyurethane polymer is made from the reaction of at least one polyisocyanate and at least one glycol chain extender.

5. The process of claim 1 , wherein said second thermoplastic polyurethane polymer has a hardness of less than about 98 Shore A.

6. The process of claim 5 , wherein said second thermoplastic polyurethane polymer has a hardness of less than about 90 Shore A.

7. The process of claim 5 , wherein said second thermoplastic polyurethane polymer comprises at least one plasticizer.

8. The process of claim 1 , wherein said first rigid thermoplastic polyurethane polymer is present at a level of from about 85.0 to about 99.8 weight percent of the total weight of said thermoplastic polyurethane blend.

9. The process of claim 8 , wherein said first rigid thermoplastic polyurethane polymer is present at a level of from about 95.0 to about 98.5 weight percent of the total weight of rigid thermoplastic polyurethane blend.

10. The process of claim 1 , wherein said catalyst is present in said second thermoplastic polyurethane polymer at a level of from about 0.1 to about 10.0 weight percent of said second thermoplastic polyurethane polymer.

11. The process of claim 10 , wherein said catalyst is present at a level of from about 1.0 to about 3.0 weight percent.

12. The process of claim 7 , wherein said plasticizer is at least one phthalate plasticizer.

13. The process of claim 7 , wherein said plasticizer is present at a level of from 0.25 to about 5.0 weight percent of said second thermoplastic polyurethane polymer.

14. The process of claim 13 , wherein said plasticizer is present at a level of from about 0.5 to about 2.0 weight percent of said second thermoplastic polyurethane polymer.

15. A process for preparing a fiber-reinforced rigid thermoplastic polyurethane composite article comprising the steps of:
(a) providing a first rigid thermoplastic polyurethane polymer, said first rigid thermoplastic polyurethane polymer being made by reacting a polyisocyanate with a chain extender, without any polyol being present, and wherein said first rigid thermoplastic polyurethane polymer has a hardness of greater than 60 Shore D;
(b) providing a second thermoplastic polyurethane polymer;
(c) absorbing at least one hydrolytically and thermally stable catalyst into said second thermoplastic polyurethane polymer after polymerization of said second thermoplastic polyurethane polymer, said catalyst being capable of depolymerizing said first rigid thermoplastic polyurethane at melt processing temperatures and repolymerizing said first rigid thermoplastic polyurethane as said first rigid thermoplastic polyurethane is cooled below melt processing temperatures, wherein said catalyst comprises dimethyl tin dilauryl mercaptide, dibutyl tin dilauryl mercaptide, or dioctyl tin dilauryl mercaptide;
(d) blending said first rigid thermoplastic polyurethane polymer and said second thermoplastic polyurethane polymer to form a thermoplastic polyurethane polymer blend;
(e) heating said thermoplastic polyurethane polymer blend to a temperature sufficient to melt said thermoplastic polyurethane polymer blend and depolymerize said first rigid thermoplastic polyurethane polymer;
(f) drawing a fiber bundle continuously through the melted thermoplastic polyurethane polymer blend;
(g) impregnating the drawn fiber bundle with the thermoplastic polyurethane polymer blend to form a composite melt;
(h) cooling said composite melt to repolymerize said first rigid thermoplastic polyurethane polymer.

16. The process of claim 15 , wherein said composite has from about 10 to about 80 weight percent fiber.

17. The process of claim 16 , wherein said composite has from about 25 to about 55 weight percent fiber.

18. The process of claim 15 , wherein said fiber is selected from the group consisting of glass fiber and carbon fiber.

19. The process of claim 15 , wherein said cooled composite is cut into lengths of from about 0.12 inch to about 1.0 inch.

20. The process of claim 19 , wherein said cooled composite is cut into lengths of from about 0.25 inch to about 0.75 inch.

Assignees

• Blayne Jerome J
• Onder Kemal
• Parnell Shane R
• Young Kimberly L
• Lubrizol Advanced Mat Inc

Inventors

• Blayne Jerome J
• Onder Kemal
• Parnell Shane R
• Young Kimberly L

Classifications

• C08G18/246

  containing also tin-carbon bonds · CPC title

• C08L75/06 Primary

  from polyesters · CPC title

• C08G18/3206

  aliphatic · CPC title

• C08L2666/20

  Macromolecular compounds having nitrogen in the main chain according to C08L75/00 - C08L79/00; Derivatives thereof · CPC title

• C08L75/04

  Polyurethanes · CPC title