Flexible foam with halogen-free flame retardant

Patent metadata

Field	Value
Publication number	US-10927227-B2
Application number	US-201816629355-A
Country	US
Kind code	B2
Filing date	Jul 11, 2018
Priority date	Jul 11, 2017
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

The invention relates to flame-retardant flexible polyurethane foams with phosphazene and to methods for producing PUR flexible foams by reacting a component A containing: A1, an isocyanate-reactive component, A2, a propellant containing water, A3, optionally auxiliary agents and additives, and A4, a flame retardant, with B, an isocyanate component. The invention is characterized in that the flame retardant A4 contains a phosphazene according to the formula (I): [PmNmXk] (I), where X independently of one another represents O-aryl or NR-aryl, at least one aryl group is substituted, X can represent a bridge, R is selected from the group of H, C1-C4 alkyl, and aryl, and m represents a number from 1 to 5, particularly preferably 3 or 4, k depends on m and represents a number from 0 to 2m, and the phosphazene does not have any groups which are reactive towards isocyanates.

First claim

The invention claimed is:

1. A process for producing open-celled flexible PUR foams comprising reacting a component A which comprises
A1 an isocyanate-reactive component,
A2 a blowing agent comprising water,
A3 optionally auxiliary and/or additive substances,
A4 a flame retardant
with
B an isocyanate component,
wherein the flame retardant A4 comprises a phosphazene corresponding to formula (I)
[P m N m X k ]  (I),

wherein
each X independently of one another represents O-aryl or NR-aryl and on average over all phosphazenes at least 10% of the aryl groups are substituted, wherein X may represent a bridge,
wherein:
R represents a H atom, a C1-C4 alkyl group, or an aryl group,

and
m represents a number from 1 to 5,
k is dependent on m and is equal to 2m
with the proviso that the phosphazene is free of isocyanate-reactive groups.

2. The process as claimed in claim 1 , wherein the isocyanate-reactive component A1 comprises a polyether polyol having a hydroxyl number of 25 mg KOH/g to 2000 mg KOH/g.

3. The process as claimed in claim 1 , wherein the isocyanate-reactive component A1 comprises a polyhydrazodicarbonamide polyol.

4. The process as claimed in claim 1 , wherein the blowing agent A2 additionally comprises at least one compound comprising at least one of a halogen-free chemical blowing agent, a halogen-free physical blowing agent, and a (hydro)fluorinated olefin.

5. The process as claimed in claim 1 , wherein the flame retardant A4 is free of components having isocyanate-reactive groups.

6. The process as claimed in claim 1 , wherein the flame retardant A4 comprises 50% by weight to 100% by weight, based on the total mass of the flame retardant A4, of the phosphazene corresponding to formula (I).

7. The process as claimed in claim 1 , wherein the content of phosphazene corresponding to formula (I) is 0.5% by weight to 40.0% by weight based on 100% of the combined weight of A1, A2, A3 and A4.

8. The process as claimed in claim 1 , wherein the flame retardant A4 additionally comprises at least one compound comprising at least one of a halogen-free phosphate and a halogen-free phosphonate.

9. The process as claimed in claim 1 , wherein the aryl group of O-aryl or NR-aryl of the substituent X is substituted with at least one of a CN group, a C1-C4 alkyl group, a nitro group, a sulfonate group, a carboxylate group, and a phosphonate group.

10. The process as claimed in claim 1 , wherein the phosphazene comprises a cyclic phosphazene.

11. The process as claimed in claim 1 , wherein component A comprises
A1 39.50% to 99.28% by weight (based on 100% of the combined weight of components A1, A2, A3 and A4) of a polyether polyol or a mixture of polyether polyols, having an average equivalent weight of 0.8 to 2.2 kg/mol and an average functionality of 1.8 to 6.2,
A2 0.2% to 20.0% by weight (based on 100% of the combined weight of components A1, A2, A3 and A4) of water,
A3 0.02% to 3.02% by weight (based on 100% of the combined weight of components A1, A2, A3 and A4) of at least one catalyst comprising an aliphatic amine, and up to 30% by weight (based on 100% of the combined weight of components A1, A2, A3 and A4) of fillers that are stably dispersed in A1 and not isocyanate-reactive,
A4 0.5% to 8.0% by weight (based on 100% of the combined weight of components A1, A2, A3 and A4) of flame retardant.

12. The process as claimed in claim 1 , wherein component B comprises 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, polyphenylpolymethylene polyisocyanate, polyisocyanates which comprise carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups or biuret groups and derive from 2,4- and/or 2,6-tolylene diisocyanate or from 4,4′- and/or 2,4′- and/or 2,2′-diphenylmethane diisocyanate, or combinations thereof.

13. The process as claimed in any of claim 1 , wherein component B comprises 60% to 100% by weight of difunctional isocyanates, based on 100% by weight of component B.

14. A flexible PUR foam obtainable by the process as claimed in claim 1 , wherein the apparent density of the flexible PUR foam is between 10 kg/m 3 and 20 kg/m 3 , or between 35 kg/m 3 and 80 kg/m 3 and the isocyanate index is between 60 and 110, or between 200 kg/m 3 and 300 kg/m 3 and the isocyanate index is between 75 and 120.

15. An article comprising the flexible PUR foam as claimed in claim 14 , in furniture cushions, textile inserts, bedding, automotive, sponges, and/or construction industries.

16. The process as claimed in claim 9 , wherein the aryl group of O-aryl is substituted with at least one of a CN group, a COOR group, and a C 1 -C 4 alkyl group.

17. The process as claimed in claim 9 , wherein the aryl group of NR-aryl is substituted with at least one C 1 -C 4 alkyl group.

18. The process as claimed in claim 10 , wherein the cyclic phosphazene has a structure corresponding to one of the general formulae (III) to (VI)

wherein
each X independently of one another represents O-aryl or NR-aryl, in which
each aryl independently represents a substituted aryl radical,
and
R represents a H atom, a C 1 -C 4 alkyl group, or an aryl group.

Assignees

• Covestro Deutschland Ag

Inventors

• Albach Rolf
• Venner Petra

Classifications

• C08J9/0038 Primary

  containing phosphorus · CPC title

• C08J9/127

  Mixtures of organic and inorganic blowing agents · CPC title

• C08J2205/06

  Flexible foams · CPC title

• C08L2203/14

  used for foams · CPC title

• C08J2203/182

  of physical blowing agents, e.g. acetone and butane · CPC title