Halogen-free flame retardant thermoplastic polyurethane elastomer composition and product and flame retardant package thereof

Patent metadata

Field	Value
Publication number	US-11613627-B2
Application number	US-201515762303-A
Country	US
Kind code	B2
Filing date	Sep 30, 2015
Priority date	Sep 29, 2015
Publication date	Mar 28, 2023
Grant date	Mar 28, 2023

Abstract

A halogen-free flame retardant thermoplastic polyurethane elastomer composition and product and flame retardant package thereof comprised thermoplastic polyurethane and halogen-free flame retardant package. The halogen-free flame retardant comprises inorganic phosphorus-based flame retardant and can further comprise expandable graphite, melamine or derivatives thereof and organic phosphorus-based flame retardant. The composition is environmentally friendly and safe, the comprehensive mechanical properties thereof are excellent, does not drip during the burning test, passed UL94 with rating of V0−1.5 mm, and the limiting oxygen index thereof can be up to 35%.

First claim

The invention claimed is:

1. A halogen-free flame retardant thermoplastic polyurethane elastomer composition comprising a thermoplastic polyurethane and a halogen-free flame retardant composition comprising, based on the weight of the thermoplastic polyurethane:
inorganic hypophosphite selected from lanthanum hypophosphite, yttrium hypophosphite, or a mixture thereof: 10-45 wt %;
expandable graphite: 2-7 wt %;
melamine or derivatives thereof: 7-13 wt %; and
organic phosphorus-based flame retardant: 4-25 wt %;
wherein the organic phosphorus-based flame retardant has the structural formula of

wherein R is

 or meta-substituted benzene ring; n is an integer from 1 to 10; X 1 , X 2 , X 3 and X 4 are the same or different and are phenyl or a C6-C18 aryl group containing 1 to 3 C1-C2 alkyl substituent respectively; and
wherein the thermoplastic polyurethane is polyether-based thermoplastic polyurethane.

2. The halogen-free flame-retardant thermoplastic polyurethane elastomer composition according to claim 1 , characterized in that the initial expansion temperature of the expandable graphite is 200° C. to 800° C.;
the average particle diameter of the expandable graphite is 5 μm to 150 μm, and the expansion multiple of the expandable graphite is 20 to 500.

3. The halogen-free flame retardant thermoplastic polyurethane elastomer composition according to claim 1 , characterized in that the derivatives of melamine are melamine cyanurate.

4. The halogen-free flame-retardant thermoplastic polyurethane elastomer composition according to claim 1 , characterized in that the weight-average molecular weight of the thermoplastic polyurethane is from 60,000 to 800,000.

5. The halogen-free flame-retardant thermoplastic polyurethane elastomer composition according to claim 1 , characterized in that the weight ratio of the halogen-free flame retardant composition to the thermoplastic polyurethane elastomer in the composition is 0.2-0.8:1.

6. An article comprising the halogen-free flame retardant thermoplastic polyurethane elastomer composition of claim 1 .

7. The halogen-free flame-retardant thermoplastic polyurethane elastomer composition according to claim 1 , characterized in that n is an integer from 1 to 5; X 1 , X 2 , X 3 and X 4 are the same or different and are

 ortho-substituted

 or ortho-substituted

8. The halogen-free flame-retardant thermoplastic polyurethane elastomer composition according to claim 2 , characterized in that the initial expansion temperature of the expandable graphite is 210 to 500° C.; and the expansion multiple of the expandable graphite is 30 to 250.

9. The halogen-free flame-retardant thermoplastic polyurethane elastomer composition according to claim 5 , characterized in that the weight ratio of the halogen-free flame retardant composition to the thermoplastic polyurethane elastomer in the composition is 0.25-0.45:1.

Assignees

• Wanhua Chemical Group Co Ltd

Inventors

• Fu Xiaoliang
• Huang Qishan
• Zhai Zhibin
• Yang Li

Classifications

• C08K5/34922

  Melamine; Derivatives thereof · CPC title

• C09K21/10

  containing nitrogen · CPC title

• C09K21/04

  containing phosphorus · CPC title

• C08K2003/324

  Alkali metal phosphate · CPC title

• C08K2003/328

  Phosphates of heavy metals · CPC title