Claims
- 1. A process for making a highly elastic polyurethane foam which comprises reacting a poly(alkylene ether) polyol which contains at least two hydroxyl groups and has a molecular weight of at least about 1500, at least 10% by weight of the hydroxyl group being primary hydroxyl groups and, a hydrazine derivative and/or hydrazine adduct having the general formula:
- R--NH--NH--R'. (H.sub.2 O).sub.n,
- in which R and R'are identical or different and represent hydrogen or alkyl, cycloalkyl, aryl, aralkyl or acyl groups and n = 0 or 1, with an organic polyisocyanate containing distilled tolylene diisocyanate in the presence of a blowing agent, the reaction being carried out in the absence of polyether-polysiloxane blocked copolymer foam stabilizers and the resultant foam having a density of from about 18 to about 50 kg/m.sup.3.
- 2. The process of claim 1 wherein the polyisocyanate is pure tolylene-2,4-diisocyanate or a mixture of tolylene 2,4-diisocyanate and tolylene-2,5-diisocyanate.
- 3. The process of claim 1 wherein the polyisocyanate consists essentially of mixtures of tolylene diisocyanate and aliphatic, cycloaliphatic or other aromatic isocyanates in which the quantity of the tolylene diiisocyanate is at least 50% by weight of the total quantity of isocyanates.
- 4. The process of claim 1 wherein the hydrazine derivatives and/or hydrazine adducts are used in quantities, based on the hydrazine group of between about 0.1 to about 0.8 parts by weight per 100 parts by weight of poly(alkylene ether) polyol.
- 5. An elastic low density polyurethane foam having a sag factor of above about 2.5, a tensile strength of above about 1 kg.wt./cm.sup.2 and an elongation at break of above about 150%, said foam having been prepared by reacting a poly(alkylene ether) polyol having at least two hydroxyl groups and a molecular weight of at least about 1500, a compound having the formula
- R -- NH -- NH -- R' . (H.sub.2 O).sub.n
- wherein R and R' are the same or different and are C.sub.1 -C.sub.12 alkyl groups, C.sub.5 -C.sub.14 cycloalkyl groups, C.sub.6 -C.sub.14 aryl groups, C.sub.7 -C.sub.20 aralkyl groups or C.sub.1 -C.sub.12 acyl groups, n is zero or 1, with an organic polyisocyanate which contains at least 50% by weight of one or more of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate isomers in a foamable reaction mixture containing a blowing agent.
- 6. The foam of claim 5 wherein the said foamable reaction mixture is free from a polyether-polysiloxane.
Parent Case Info
This application is a continuation of our copending application Ser. No. 646,466 filed Jan. 5, 1976 now abandoned, which itself is a continuation of application Ser. No. 455,706 filed Mar. 28, 1974, and now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
2834748 |
Bailey et al. |
May 1958 |
|
2957852 |
Frankenburg et al. |
Oct 1960 |
|
3316285 |
Cleveland |
Apr 1967 |
|
Foreign Referenced Citations (4)
Number |
Date |
Country |
1,499,901 |
Nov 1967 |
FRX |
2,110,055 |
Sep 1972 |
DEX |
1,090,589 |
Nov 1967 |
GBX |
1,360,131 |
Jul 1974 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Saunders et al., Polyurethane, Part II, Interscience, NY, 1964, pp. 120-124. |
Continuations (2)
|
Number |
Date |
Country |
Parent |
646466 |
Jan 1976 |
|
Parent |
455706 |
Mar 1974 |
|