Nitrogen-free and low-nitrogen crosslinking additives for cold-cure flexible slabstock foam having improved compression and aging properties

Patent metadata

Field	Value
Publication number	US-2022017680-A1
Application number	US-202117367456-A
Country	US
Kind code	A1
Filing date	Jul 5, 2021
Priority date	Jul 16, 2020
Publication date	Jan 20, 2022
Grant date	—

Abstract

Process for producing cold-cure flexible slabstock PU foams by reaction of at least one polyol component and at least one isocyanate component in the presence of water and at least one catalyst and at least one crosslinker, wherein no nitrogen-containing crosslinkers having an expanded OH number above 1000 mg KOH/g are employed in a total amount >0.5 parts by weight, preferably >0.1 parts by weight, based on 100 parts by weight of polyol.

First claim

1 . A process for producing cold-cure flexible slabstock PU foams by reaction of at least one polyol component and at least one isocyanate component in the presence of water and at least one catalyst, comprising at least one tin catalyst, and at least one crosslinker, wherein no nitrogen-containing crosslinkers having an expanded OH number above 1000 mg KOH/g are employed in a total amount >0.5 parts by weight, based on 100 parts by weight of polyol,
wherein nitrogen-containing crosslinkers in the context of the present invention have a nitrogen content of >0.5% by weight, measured by Kjeldahl analysis, % by weight based on the respective crosslinker, and wherein at least two nitrogen-free or low-nitrogen crosslinkers having a nitrogen content of ≤0.5% by weight, measured by Kjeldahl analysis, % by weight based on the respective crosslinker, are employed in a total amount ≥0.1 parts by weight, based on 100 parts by weight of polyol, and wherein not more than 4 parts of water per 100 parts of polyol are employed and wherein, based on the total polyol component, >50% by weight of cold-cure flexible foam ether polyols having molar masses of >1500 g/mol per OH group are employed and wherein the individual crosslinkers have a functionality of isocyanate-reactive groups of ≥3 and wherein isocyanates suitable as isocyanate components include all isocyanates containing at least two isocyanate groups and wherein the isocyanate index is >95 and ≤115 and wherein less than 2 parts polyester ether having an OH number of 55 to 57 mg KOH/g per 100 parts of polyol is employed.

2 . The process according to claim 1 , wherein at least two nitrogen-free or low-nitrogen crosslinkers having a nitrogen content of ≤0.5% by weight, measured by Kjeldahl analysis, % by weight based on the respective crosslinker, from the group of
(a) sugar alcohols selected from the group consisting of sorbitol, mannitol, maltitol, isomalt, lactitol, xylitol, threitol, erythritol and/or arabitol, in particular sorbitol and maltitol,
(b) glycerols/their derivatives selected from the group consisting of glycerol, diglycerol and/or triglycerol, in particular diglycerol and triglycerol,
and/or

(c) further low molecular weight nitrogen-free or low-nitrogen crosslinkers such as pentaerythritol and/or 1,1,1-trimethylolpropane are employed,
wherein that at least one nitrogen-free or low-nitrogen crosslinker from the group of sugar alcohols (a) and at least one nitrogen-free or low-nitrogen crosslinker from the group of glycerols/their derivatives (b) are employed.

3 . The process according to claim 1 , wherein the crosslinker is employed as a water-containing additive comprising >0% to 50% by weight of solvent, and 50% to <100% by weight of crosslinker, comprising at least two nitrogen-free or low-nitrogen crosslinkers having a nitrogen content of ≤0.5% by weight, measured by Kjeldahl analysis, % by weight based on the respective crosslinker, said crosslinker comprising sugar alcohol(s), glycerols/their derivatives and/or further low molecular weight nitrogen-free or low-nitrogen crosslinkers,
but at least one nitrogen-free or low-nitrogen crosslinker from the group of sugar alcohols and at least one nitrogen-free or low-nitrogen crosslinker from the group of glycerols/their derivatives, particularly preferably sorbitol and/or maltitol and additionally diglycerol and/or triglycerol.

4 . The process according to claim 1 , wherein at least 50% by weight of the altogether employed polyols of the polyol component have a functionality of 2.5 to 4, number-average molecular weights determined by gel permeation chromatography in the range from 4500 to 8000 g/mol and comprise >50%, of primary hydroxyl groups.

5 . The process according to claim 1 , wherein cold-cure foam polymer polyols are employed.

6 . A cold-cure flexible slabstock PU foam, obtained by a process according to claim 1 .

7 . A cold-cure flexible slabstock PU foam according to claim 6 , wherein based on its starting volume the PU foam body has been compressed by at least 20%, and is kept in compressed form by an auxiliary means, in particular packaging means, for at least 20 hours.

8 . A crosslinking solvent-containing, additive for use in cold-cure flexible slabstock PU foam formulations comprising >0% to 50% by weight of solvent, and 50% to <100% by weight of crosslinker, comprising at least two nitrogen-free or low-nitrogen crosslinkers having a nitrogen content of ≤0.5% by weight, measured by Kjeldahl analysis, % by weight based on the respective crosslinker, said crosslinker preferably comprising sugar alcohol(s) and/or glycerols/their derivatives, but at least one crosslinker from the group of sugar alcohols and at least one crosslinker from the group of glycerols/their derivatives, with the proviso that no nitrogen-containing crosslinkers having an expanded OH number above 1000 mg KOH/g are employed in a total amount >5% by weight, based on 100% by weight of the solvent-containing additive.

9 . A mattress or cushion comprising the cold-cure flexible slabstock PU foam obtainable by a process according to claim 1 for providing mattresses and/or cushions with improved aging, long-term usage and compression properties as well as improved dimensional recovery after compression, in particular with additionally improved emission behavior.

10 . The crosslinking solvent-containing additive for use in cold-cure flexible slabstock foam formulations according to claim 8 for improving the compression set values of the resulting cold-cure flexible slabstock polyurethane foams, in particular for realizing improved aging, long-term usage and compression properties as well as improved dimensional recovery after compression.

11 . The process according to claim 1 , wherein it is sorbitol and/or maltitol and diglycerol and/or triglycerol are employed.

12 . The process according to claim 1 , wherein no nitrogen-containing crosslinkers having an expanded OH number above 1000 mg KOH/g are employed in a total amount >0.1 parts by weight based on 100 parts by weight of polyol.

13 . The process according to claim 1 , wherein at least two nitrogen-free or low-nitrogen crosslinkers having a nitrogen content of ≤0.5% by weight, measured by Kjeldahl analysis, % by weight based on the respective crosslinker, are employed in a total amount ≥0.2 to 3 parts by weight.

14 . The process according to claim 1 , wherein at least two nitrogen-free or low-nitrogen crosslinkers having a nitrogen content of ≤0.5% by weight, measured by Kjeldahl analysis, % by weight based on the respective crosslinker, are employed in a total amount >0.2 to 3 parts by weight.

15 . The process according to claim 1 , wherein at least two nitrogen-free or low-nitrogen crosslinkers having a nitrogen content of ≤0.5% by weight, measured by Kjeldahl analysis, % by weight based on the respective crosslinker, are employed in a total amount ≥0.5 to 2 parts by weight.

16 . The process according to claim 1 , wherein at least 50% by weight of the altogether employed polyols of the polyol component have a functionality of 2.5 to 4, number-average molecular weights determined by gel permeation chromatography in the range from 4500 to 8000 g/mol and comprise from 70 to 95% of primary hydroxyl groups.

17 . The cold-cure flexible slabstock PU foam according to claim 6 , wherein based on its starting volume the PU foam body has been compressed by at least 30%, and is kept in compressed form by an auxiliary means, in particular packaging means, for at least 20 hours.

18 . The cold-cure flexible slabsto

Assignees

• Evonik Operations Gmbh

Inventors

• Modro Harald
• Feldmann Kai-Oliver
• Vidakovic Mladen
• Landers Rüdiger
• Hermann Daniela

Classifications

• C08G2110/005

  < 50kg/m3 · CPC title

• C08G2101/00

  Manufacture of cellular products · CPC title

• C08G2110/0083

  prepared using water as the sole blowing agent · CPC title

• C08G18/6564

  with compounds of group C08G18/3203 · CPC title

• C08G2110/0008

  flexible · CPC title