GB1602003A

GB1602003A - Flexible urethane foams

Info

Publication number: GB1602003A
Application number: GB8298/78A
Authority: GB
Original assignee: Stauffer Chemical Co
Current assignee: Stauffer Chemical Co
Priority date: 1977-04-18
Filing date: 1978-03-02
Publication date: 1981-11-04
Also published as: NL7802731A; IT7848905A0; SE7802836L; BE866068A; IL54074A0; DE2808117A1; AU3364878A; IL54074A; CS202596B2; FR2388006A1; BR7802378A; NO781255L; JPS53129296A; ZA781012B; DK103978A

Description

(54) FLEXIBLE URETHANE FOAMS (71) We, STAUFFER CHEMICAL COMPANY, a corporation organised under the laws of the State of Delaware, United States of America, of Westport, Connecticut 06880, United States of America; do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to flexible urethane foams; more particularly, it concerns flame retarded foams having improved physical characteristics.

When flexible urethane foam is treated with flame retardants to reduce its flammability, certain physical properties of the foam are detrimentally affected.

One of the frequently affected properties is compression set. That is, when a sample of the foam is heated while compressed, the foam fails to return to its original height when the compression is relieved. This is undesirable because the foam is then permanently deformed.

A standard test (ASTM DO1564-71) for compression set consists of compressing the foam to 90% of its original thickness and leaving it for 22 hours at 70"C. The compression set is determined by measuring the percent deformation from original thickness after the compression is released.

In accordance with the present invention, the physical properties of urethane foams treated with certain flame retardants are improved by the addition of an acid acceptor to the foam.

Most flame retardants cause compression set problems in flexible urethane foams. Flame retardants that are labile by virtue of having an aliphatic halogen content or easily saponifiable ester groups are particularly troublesome with respect to causing compression set problems in flexible urethane foams.

Without intending to be bound thereby, the theory of the present invention is based upon the fact that total cure of the flexible foam must be optimized in order for it to have good compression set properties. This is particularly true with respect to terminal isocyanate groups in the foam and the subsequent conversion thereof to terminal amine groups. If acids are formed during the foaming process, they will neutralize the amine catalysts of the foam formulation thereby preventing reaction of the isocyanate groups to form urethane and urea linkages. These unreacted groups then may either themselves contribute to poor compression set by reaction in the compressed state or by subsequent conversion to amine groups which may react in the compressed state. Reactions in the compressed state provide restraining forces that prevent the compressed foam from returning to its original height.

By providing an acid acceptor in accordance with the present invention, these problems are obviated because the acid acceptor rather than the amine catalysts will neutralize the acid formed.

According to the present invention poly(haloethyl-ethyleneoxy) phosphoric acid esters are used particularly as flame retardants in the flexible polyurethane foams. Such flame retardants are described, for example, in United States Patent No. 3,896,187.

Mixtures of these flame retardants with other flame retardants may also be used in accordance with the present invention. Such other flame retardants include: tris (haloalkyl) phosphates, such as tris (dichloropropyl) phosphate, tris (dibromopropyl) phosphate, tris (fi-chloroethyl) phosphate and tris (fi- chlorophenyl) phosphate.

The flame retardants are employed in a flame retardant amount, generally from 3 to 20 percent, by weight, based on the weight of polyol in the foam formulation.

According to one aspect of the present invention, there is provided a flame retardant polyurethane foam which comprises a flexible polyurethane foam, a flame retardant amount of a flame retardant comprising a poly(haloethylethyleneoxy) phosphoric acid ester and from 0.1 to 5.0 per cent, by weight, based on the weight of flame retardant in the foam formulation, of an acid acceptor which is y-glycidoxy propyl trimethoxy silane.

According to another aspect ot the present invention there is provlded a composition for flame retarding a flexible polyurethane foam which comprises a flame retardant comprising a poly (haloethyl-ethylenoxy) phosphoric acid ester and from 0.1 to 5.0 per cent, by weight, based on the weight of flame retardant in the foam formulation, of an acid acceptor which is y glycidoxy propyl trimethoxy silane.

The acid acceptor utilized in accordance with the present invention may be admixed with the foam formulation by conventional techniques. For example, it may be admixed alone or in combination with other ingredients of the foam formulation. It may also be admixed with the flame retardant composition prior to admixture of the flame retardant with the foam formulation.

A flame retardant composition incorporating the acid acceptor therein may be conveniently prepared prior to incorporation into the foam formulation.

Conventional foam formulations for flexible polyurethane foams are utilized in accordance with the present invention. The selection of ingredients and process conditions may readily be determined by those skilled in the art.

The present invention will be more fully illustrated in the Examples which follow.

EXAMPLES Three foam formulations were prepared having the following composition: 3560 molecular weight polyol based upon glycerin having an OH number of 47.3 and containing internal ethylene oxide units and secondary OH groups 100 g.

non-hydrolyzable silicone copolymer 1.0 g.

water 4.0 g.

THANCAT (Registered Trade Mark) DD-a proprietary tertiary amine catalyst available from Jefferson Chemical Company 0.1 g.

trimethyl aminoethyl piperazine 0.1 g.

stannous octoate (50%) 0.4 g.

80/20 toluene diisocyanate (110 Index) 50.3 g.

The three foam formulations designated Foam A, Foam B and Foam C were then admixed with flame retardants and epoxides and processed pursuant to the following Table: TABLE Foam A Foam B Foam C FR* 8 8 g. - FR*+I%A''' 8 8 g.

Processing Cream Time (sec) 9 11 13 Rise Time (sec) 79 86 94 Air Flow (cfm) 3.0 4.3 4.5 Density(pcf) 1.70 1.71 1.73 90% Compression Set at 700 C. for 22 Hours 24 hr. cure 74.0 85 10.0 48 hr. cure'21 32.3 36.9 8.1 *2:1 blend of poly(chloroethyl-ethyleneoxy)phosphoric acid ester:tris (dichloropropyl) phosphate "' y-glycidoxy propyl trimethoxy silane The The cure was at room temperature for the period of time indicated prior to application of compression.

The compression set values in the foregoing Table signify the percentage of permanent deformation of the foam after the foam has been compressed (deformed) to ninety per cent of its original height followed by release of the compression.

WHAT WE CLAIM IS: 1. A flame retardant polyurethane foam which comprises a flexible polyurethane foam, a flame retardant amount of a flame retardant comprising a poly(haloethyl-ethyleneoxy) phosphoric acid ester and from 0.1 to 5.0 per cent, by weight, based on the weight of flame retardant in the foam formulation, of an acid acceptor which is y-glycidoxy propyl trimethoxy silane.

2. A flame retardant polyurethane foam as claimed in claim I in which the flame retardant further comprises a tris (haloalkyl) phosphate.

3. A flame retardant polyurethane foam as claimed in claim 2 in which the weight ratio of poly(haloethyl-ethyleneoxy) phosphoric acid ester to tris (haloalkyl) phosphate is about 2:1.

4. A flame retardant polyurethane foam as claimed in claim 2 or claim 3 in which the poly (haloethyl-ethyleneoxy) phosphoric acid ester is poly (chloroethyl ethyleneoxy) phosphoric acid ester and the tris (haloalkyl) phosphate is tris (dichloropropyl) phosphate.

5. A flame retardant polyurethane foam as claimed in claim 1 substantially as herein described.

6. A flame retardant polyurethane foam is claimed in claim 1 substantially as herein described with reference to the Examples.

7. A composition for flame retarding a flexible polyurethane foam which comprises a flame retardant comprising a poly (haloethyl - ethyleneoxy) phosphoric acid ester and from 0.1 to 5.U per cent, by weight, based on the weight of flame retardant in the foam formulation, of an acid acceptor which is y glycidoxy propyl trimethoxy silane.

8. A composition as claimed in claim 7 further comprising a tris (haloalkyl) phosphate.

9. A composition as claimed in claim 8 in which the weight ratio of poly (haloethyl-ethyleneoxy) phosphoric acid ester to tris (haloalkyl) phosphate is about 2:1.

10. A composition -as claimed in claim 8 or claim 9 in which the poly (haloethyl-ethyleneoxy) phosphoric acid ester is poly (chloroethyl-ethyleneoxy) phosphoric acid ester and the tris (haloalkyl) phosphate is tris (dichloropropyl) phosphate.

11. A composition as claimed in claim 7 substantially as herein described.

12. A composition as claimed in claim 7 substantially as herein described with reference to the Examples.

13. A process for the preparation of a flame retardant, flexible polyurethane

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

TABLE Foam A Foam B Foam C FR* 8 8 g. - FR*+I%A''' 8 8 g.

Processing Cream Time (sec) 9 11 13 Rise Time (sec) 79 86 94 Air Flow (cfm) 3.0 4.3 4.5 Density(pcf) 1.70 1.71 1.73 90% Compression Set at 700 C. for 22 Hours

24 hr. cure 74.0 85 10.0

48 hr. cure'21 32.3 36.9 8.1 *2:1 blend of poly(chloroethyl-ethyleneoxy)phosphoric acid ester:tris (dichloropropyl) phosphate "' y-glycidoxy propyl trimethoxy silane The The cure was at room temperature for the period of time indicated prior to application of compression.

The compression set values in the foregoing Table signify the percentage of permanent deformation of the foam after the foam has been compressed (deformed) to ninety per cent of its original height followed by release of the compression.

WHAT WE CLAIM IS: 1. A flame retardant polyurethane foam which comprises a flexible polyurethane foam, a flame retardant amount of a flame retardant comprising a poly(haloethyl-ethyleneoxy) phosphoric acid ester and from 0.1 to 5.0 per cent, by weight, based on the weight of flame retardant in the foam formulation, of an acid acceptor which is y-glycidoxy propyl trimethoxy silane.
2. A flame retardant polyurethane foam as claimed in claim I in which the flame retardant further comprises a tris (haloalkyl) phosphate.
3. A flame retardant polyurethane foam as claimed in claim 2 in which the weight ratio of poly(haloethyl-ethyleneoxy) phosphoric acid ester to tris (haloalkyl) phosphate is about 2:1.
4. A flame retardant polyurethane foam as claimed in claim 2 or claim 3 in which the poly (haloethyl-ethyleneoxy) phosphoric acid ester is poly (chloroethyl ethyleneoxy) phosphoric acid ester and the tris (haloalkyl) phosphate is tris (dichloropropyl) phosphate.
5. A flame retardant polyurethane foam as claimed in claim 1 substantially as herein described.
6. A flame retardant polyurethane foam is claimed in claim 1 substantially as herein described with reference to the Examples.
7. A composition for flame retarding a flexible polyurethane foam which comprises a flame retardant comprising a poly (haloethyl - ethyleneoxy) phosphoric acid ester and from 0.1 to 5.U per cent, by weight, based on the weight of flame retardant in the foam formulation, of an acid acceptor which is y glycidoxy propyl trimethoxy silane.
8. A composition as claimed in claim 7 further comprising a tris (haloalkyl) phosphate.
9. A composition as claimed in claim 8 in which the weight ratio of poly (haloethyl-ethyleneoxy) phosphoric acid ester to tris (haloalkyl) phosphate is about 2:1.
10. A composition -as claimed in claim 8 or claim 9 in which the poly (haloethyl-ethyleneoxy) phosphoric acid ester is poly (chloroethyl-ethyleneoxy) phosphoric acid ester and the tris (haloalkyl) phosphate is tris (dichloropropyl) phosphate.
11. A composition as claimed in claim 7 substantially as herein described.
12. A composition as claimed in claim 7 substantially as herein described with reference to the Examples.
13. A process for the preparation of a flame retardant, flexible polyurethane

foam which comprises admixing with a polyurethane foam formulation a flame retardant comprising a poly (haloethyl-ethyleneoxy) phosphoric acid ester and optionally a tris (haloalkyl) phosphate and further admixing from 0.1 to 5.0 per cent, by weight, based on the weight of flame retardant in the foam formulation, of an acid acceptor which is y-glycidoxy propyl trimethoxy silane, followed by curing.
14. A process as claimed in claim 13 substantially as herein described.