Viscoelastic elastomeric polyurethane foams, process for preparing them and use thereof

Patent metadata

Field	Value
Publication number	US-12552894-B2
Application number	US-202118002734-A
Country	US
Kind code	B2
Filing date	Jun 21, 2021
Priority date	Jun 22, 2020
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

Disclosed herein are viscoelastic elastomeric polyurethane foams, a process for preparing them and a method of using them in making shaped articles. Further disclosed herein are viscoelastic elastomeric polyurethane foams having improved, unique impact absorption performance.

First claim

The invention claimed is:

1 . A viscoelastic elastomeric polyurethane foam obtained by reacting a reactive mixture comprising:
(A) an isocyanate component comprising at least one isocyanate prepolymer (A1), wherein the isocyanate component has an NCO content in between 10 wt. % to 30 wt. %, and (B) an isocyanate reactive component comprising a mixture of
(a) 60 wt. % to 95 wt. % of at least one natural oil polyol having an average functionality in between 2.0 to 4.0 and OH value in between 30 mg KOH/g to 600 mg KOH/g, determined according to DIN 53240,
(b) 0.1 wt. % to 10.0 wt. % of at least one first polyether polyol having an average functionality in between 2.5 to 5.0 and OH value in between 200 mg KOH/g to 450 mg KOH/g, determined according to DIN 53240, which is prepared by addition of at least one alkylene oxide onto an amine,
(c) 1.0 wt. % to 30.0 wt. % of at least one second polyether polyol having an average functionality in between 2.0 to 4.0 and OH value in between 20 mg KOH/g to 200 mg KOH/g, determined according to DIN 53240, which is prepared by addition of ethylene oxide and propylene oxide onto at least one H-functional starter substance, wherein the proportion of ethylene oxide is in between 40 wt. % to 95 wt. % based on the weight of the at least one second polyether polyol, and
(d) 0 wt. % to 10.0 wt. % of at least one chain extender and/or crosslinker having a molecular weight in between 40 g/mol to 499 g/mol, wherein wt. % of the at least one natural oil polyol, the at least one first polyether polyol, the at least one second polyether polyol, and the at least one chain extender and/or crosslinker are based on the sum of (a), (b), (c) and (d), in the presence of
(C) a blowing agent mixture comprising water (C1) and at least one hydrofluorocarbon (C2), or water (C1) and at least one hydrofluoroolefin (C3).

2 . The viscoelastic elastomeric polyurethane foam according to claim 1 , wherein the isocyanate component (A) further comprises at least one isocyanate component selected from the group consisting of carbodiimide-modified isocyanates (A2), polymeric methylene diphenyl diisocyanate (A3), isocyanates (A4) comprising biuret and/or isocyanurate groups, and diphenylmethane 2,2′-, 2,4′- and/or 4,4′-diisocyanate (A5).

3 . The viscoelastic elastomeric polyurethane foam according to claim 1 , wherein the isocyanate component is a mixture of the at least one isocyanate prepolymer (A1) and (A2) carbodiimide-modified isocyanates.

4 . The viscoelastic elastomeric polyurethane foam according to claim 1 , wherein the amount of the at least one isocyanate prepolymer (A1) is in between 10 wt. % to 90 wt. %, based on the total weight of the isocyanate component (A).

5 . The viscoelastic elastomeric polyurethane foam according to claim 2 , wherein the carbodiimide-modified isocyanates (A2) are selected from carbodiimide-modified diphenylmethane 2,2′-, 2,4′- and 4,4′-diisocyanates.

6 . The viscoelastic elastomeric polyurethane foam according to claim 1 , wherein the at least one natural oil polyol is castor oil and/or hydrogenated castor oil.

7 . The viscoelastic elastomeric polyurethane foam according to claim 1 , B wherein the amine in the at least one first polyether polyol is selected from the group consisting of toluenediamine, phenylenediamine, diaminodiphenylmethane, and isomers thereof.

8 . The viscoelastic elastomeric polyurethane foam according to claim 1 , B wherein the proportion of ethylene oxide in the at least one second polyether polyol is in between B 60 wt. % to 85 wt. % based on the weight of the at least one second polyether polyol.

9 . The viscoelastic elastomeric polyurethane foam according to claim 1 , wherein the at least one hydrofluorocarbon (C2) is 1,1,1,3,3-pentafluoropropane.

10 . The viscoelastic elastomeric polyurethane foam according to claim 1 , wherein the at least one hydrofluoroolefin (C3) is cis-1,1,1,4,4,4-hexafluoro-2-butene.

11 . The viscoelastic elastomeric polyurethane foam according to claim 1 , wherein the reactive mixture further comprises at least one further component selected from the group consisting of catalysts (D), surfactants (E) and additives (F).

12 . The viscoelastic elastomeric polyurethane foam according to claim 1 , wherein the reaction takes place at an isocyanate index in between 70 to 120.

13 . A process for preparing the viscoelastic elastomeric polyurethane foam according to claim 1 , the process comprising mixing (A), (B), and (C).

14 . A shaped article comprising the viscoelastic elastomeric polyurethane foam according to claim 1 .

Assignees

• Basf Se

Inventors

• Wang Liying
• Bouguettaya Mohamed
• Levy David

Classifications

• C08J2375/08

  from polyethers · CPC title

• C08J2375/06

  from polyesters · CPC title

• C08J2205/06

  Flexible foams · CPC title

• C08J2203/142

  Halogenated saturated hydrocarbons, e.g. H3C-CF3 · CPC title

• C08J2203/10

  Water or water-releasing compounds · CPC title