Use of softening additives in polyurethane foam

Abstract

An amine softening additive is useful in softening all-water blown flexible polyurethane foam to achieve low IFD valves while retaining the other commercially necessary properties of the foam. The additives are tertiary amine polyisocyanate catalysts which contain at least one contiguous three carbon chain and should be added to the foam system at about 0.1 to 2.0 parts per hundred of polyol.

We claim: 
     
       1. A flexible slabstock polyurethane foam having a density of less than 1.5 pcf comprising .Iadd.the reaction product of mixing together.Iaddend.: a. a polyol with substantially all secondary hydroxyl functionality having an equivalent weight of about 400 to 1500 grams/equivalent and an ethylene oxide content of less than 20%;   b. an organic isocyanate present at an index of 60-120;   c. water at 1 to 12 pphp;   d. a surface active agent at 0.0001 to 5 weight percent;   e. a polyurethane catalyst at 0.0001 to 5 weight percent;   f. a foam processing aid at 0.2 to 10 pphp; and   g. a tertiary amine polyisocyanate softening agent with at least one contiguous three carbon chain at 0.1 to 2 pphp; wherein the foam has a 25% IFD of 5 to 18 pounds.     
     
     
       2. A foam according to claim 1 wherein the tertiary amine polyisocyanate softening agent is 1,3,5-tris-(3-dimethylaminopropyl)-1,3,5-triazine. 
     
     
       3. A foam according to claim 1 wherein the tertiary amine polyisocyanate softening is bis-(3-dimethylaminopropyl)methylamine. 
     
     
       4. A foam according to claim 1 additionally comprising ethylene oxide, propylene oxide based block copolymers which are terminated with a primary amine. 
     
     
       5. A foam according to claim 1 wherein the foam processing is comprised of a crosslinking/extending agent and a cell opening agent. 
     
     
       6. A foam according to claim 5, wherein the cell opening agent is a polyethylene oxide adduct of glycerol of a molecular weight of about 990 gms/mole, with an equivalent weight of about 330. 
     
     
       7. A process for making flexible slabstock polyurethane foam having a density of less than 1.5 pcf comprising mixing: a. a polyol with substantially all secondary hydroxyl functionality having an equivalent weight of about 400 to 1500 grams/equivalent and an ethylene oxide content of less than 20%;   b. an organic isocyanate present at an index of 60-120;   c. water at 1 to 12 pphp;   d. a surface active agent at 0.0001 to 5 weight percent;   e. a polyurethane catalyst at 0.0001 to 5 weight percent;   f. a foam processing aid at 0.2 to 10 pphp; and   g. a tertiary amino polyisocyanate softening agent with at least one contiguous three carbon chain at 0.1 to 2 pphp such that the foam has a 25% IFD of 5 to 18 pounds.     
     
     
       8. A process according to claim 7 wherein the tertiary amine polyisocyanate catalyst is 1,3,5-tris-(3-dimethylaminopropyl)-1,3,5-triazine. 
     
     
       9. A process according to claim 7 wherein the polyisocyanate catalyst is bis-(3dimethylaminopropyl)methylamine. 
     
     
       10. A process according to claim 7 additionally comprising ethylene oxide, propylene oxide based block copolymers which are terminated with a primary amine. 
     
     
       11. A process according to claim 7 wherein the foam processing is comprised of a crosslinking/extending agent and a cell opening agent. 
     
     
       12. A process according to claim 11, wherein the cell opening agent is a polyethylene oxide adduct of glycerol of a molecular weight of about 990 gms/mole, with an equivalent weight of about 330. 
     
     
       13. A polyurethane foam according to claim 1 wherein the the tertiary amine polyisocyanate softening agent is dimethylcyclohexyl amine. 
     
     
       14. A method according to claim 7 wherein the the tertiary amine polyisocyanate softening agent is dimethylcyclohexyl amine. 
     
     
       15. A flexible slabstock polyurethane foam having a density of less than 1.5 pcf comprising .Iadd.the reaction product of mixing together.Iaddend.: a. a polyol with substantially all secondary hydroxyl functionality having an equivalent weight of about 400 to 1500 grams/equivalent and an ethylene oxide content of less than 20%;   b. an organic isocyanate present at an index of 60-120;   c. water at 1 to 12 pphp;   d. a surface active agent at 0.0001 to 5 weight percent;   e. a polyurethane catalyst at 0.0001 to 5 weight percent;   f. a foam processing aid at 0.2 to 10 pphp; and   g. a tertiary amine polyisocyanate softening agent with at least one contiguous three carbon chain at 0.1 to 2 pphp; wherein the foam has a 25% IFD of 10 to 21 pounds.     
     
     
       16. A foam according to claim 15 wherein the tertiary amine polyisocyanate softening agent is 1,3,5-tris-(3-dimethylammopropyl)-1,3,5-triazine. 
     
     
       17. A foam according to claim 15 wherein the tertiary amine polyisocyanate softening agent is bis-(3-dimethylaminopropyl)methylamine. 
     
     
       18. A polyurethane foam according to claim 15 wherein the the tertiary amine polyisocyanate softening agent is dimethylcyclohexyl amine.