Flame retardant polyurethane foam and method for producing same

Patent metadata

Field	Value
Publication number	US-9908984-B2
Application number	US-201414773926-A
Country	US
Kind code	B2
Filing date	Mar 5, 2014
Priority date	Mar 15, 2013
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A polyurethane foam having an initial UL 94 vertical flame classification of V-0 and maintaining a UL 94 vertical flame classification of V-0 after one week of heat aging at 150° C. is formed as the reaction product of an isocyanate component and an isocyanate-reactive component in the presence of a blowing agent. The isocyanate component includes an isocyanate-containing compound and a non-reactive phosphorous compound that is present in an amount ranging from 1 to 20 weight percent based on the total weight of the polyurethane foam. The isocyanate-reactive component includes a polyether polyol and expandable graphite that is present in an amount ranging from 3 to 30 weight percent based on the total weight of the polyurethane foam.

First claim

What is claimed is:

1. A method for forming a polyurethane foam comprising the steps of:
providing an isocyanate component comprising:
an isocyanate-containing compound, and
a non-halogenated, non-reactive phosphorous compound present in an amount ranging from 1 to 20 weight percent based on the total weight of the polyurethane foam and having a cumulative weight loss of 2% or less at 200° C. as measured by thermogravimetric analysis using a 10° C./min. heating rate in nitrogen to 200° C., wherein the non-halogenated, non-reactive phosphorous compound is liquid at 25° C. and is premixed with the isocyanate-containing compound prior to reacting the isocyanate component with the isocyanate-reactive component;

providing an isocyanate-reactive component comprising:
expandable graphite present in an amount ranging from 3 to 30 weight percent based on the total weight of the polyurethane foam, and
a polyether polyol having a weight-average molecular weight from 2,500 to 6,000 g/mol and a hydroxyl number from 25 to 60 KOH/g,
wherein the non-halogenated, non-reactive phosphorous compound is not premixed in the provided isocyanate-reactive component; and

reacting the isocyanate component with the isocyanate-reactive component in the presence of a blowing agent to form the polyurethane foam.

2. The method as set forth in claim 1 , further comprising the step of premixing the expandable graphite with the polyether polyol prior to reacting the isocyanate component with the isocyanate-reactive component.

3. A method for forming a polyurethane foam comprising the steps of:
(a) mixing expandable graphite present in an amount ranging from 3 to 30 weight percent based on the total weight of the polyurethane foam with a first isocyanate-reactive component;
(b) providing an isocyanate component comprising:
an isocyanate-containing compound, and
a non-halogenated, non-reactive phosphorous compound premixed with the isocyanate-containing compound, the non-halogenated, non-reactive phosphorous compound present in an amount ranging from 1 to 20 weight percent based on the total weight of the polyurethane foam, the non-reactive phosphorous compound having a cumulative weight loss of 2% or less above 200° C. as measured by thermogravimetric analysis using a 10° C./min. heating rate in nitrogen to 200° C., wherein the non-halogenated, non-reactive phosphorous compound is liquid at 25° C.;

(c) introducing the isocyanate component and a second isocyanate-reactive component to a chamber under high pressure in the presence of a blowing agent;
(d) introducing the mixed expandable graphite and first isocyanate-reactive component to the chamber at a lower pressure; and
(e) reacting the isocyanate component with the first isocyanate-reactive component and the second isocyanate-reactive component in the presence of the blowing agent to form the polyurethane foam;
wherein the first isocyanate-reactive component and the second isocyanate-component each comprise a polyether polyol having a weight-average molecular weight from 2,500 to 6,000 g/mol and a hydroxyl number from 25 to 60 KOH/g, and
wherein the non-halogenated, non-reactive phosphorous compound is not premixed with the first isocyanate-reactive component and is not premixed with the second isocyanate component prior to reacting the isocyanate component with the first isocyanate-reactive component and the second isocyanate-reactive component.

4. The method of claim 3 wherein the first isocyanate-reactive component is the same composition as the second isocyanate-reactive component.

5. The method of claim 1 , wherein the formed polyurethane foam has a UL 94 vertical flame classification of V-0.

6. The method of claim 5 , wherein the formed polyurethane foam maintains a UL 94 vertical flame classification of V-0 after one week of heat aging at 150° C.

7. The method of claim 5 , wherein the formed polyurethane foam has a density of from 32 to 240 kg/m 3 .

8. The method of claim 3 , wherein the non-halogenated, non-reactive phosphorous compound is premixed with the isocyanate-containing compound prior to steps (c), (d) and (e).

9. The method of claim 3 , wherein the formed polyurethane foam has a UL 94 vertical flame classification of V-0.

10. The method of claim 3 , wherein the formed polyurethane foam maintains a UL 94 vertical flame classification of V-0 after one week of heat aging at 150° C.

11. The method of claim 3 , wherein the formed polyurethane foam has a density of from 32 to 240 kg/m 3 .

Assignees

• Basf Se

Inventors

• Neff Raymond
• Wang Liying
• Gershanovich Alexander

Classifications

• C08G2101/0058

  Chemistry & Metallurgy · mapped topic

• C08K5/521

  Esters of phosphoric acids, e.g. of H3PO4 · CPC title

• C08G18/7664

  containing alkylene polyphenyl groups · CPC title

• C08J2201/02

  characterised by mechanical pre- or post-treatments · CPC title

• C08G2101/0066

  Chemistry & Metallurgy · mapped topic