Claims
- 1. A mixture for preparing polyurethane foams having a reduced aromatic amine content comprising an admixture of
- (a) a member of the group consisting of
- 1. a urethane-containing prepolymer having polyether or polyester backbone segments end-capped with an aromatic isocyanate and
- 2. an aromatic polyisocyanate and a polyol selected from the group consisting of polyethers and polyesters;
- (b) 0.01 to 15% by weight of said group member (a) of an aromatic amine scavenger selected from the group consisting of cyclohexyl monoisothiocyanate and a hindered cycloaliphatic monoisocyanate of the general formula: ##STR5## wherein R.sub.1 -R.sub.7 are members of the group consisting of H, alkyl, cycloalkyl, aryl, alkaryl, aralkyl or mixtures thereof wherein the alkyl groups contain 1-18 carbon atoms, the cycloalkyl groups contain 4-8 carbon atoms and the aryl groups contain 6-14 carbon atoms with the proviso that where R.sub.3 is a group member other than H, R.sub.1, R.sub.2, R.sub.4 and R.sub.5 can be H and with the further proviso that where R.sub.3 is H at least two of R.sub.1, R.sub.2, R.sub.4 and R.sub.5 are group members other than H and x is 1 to 7; and
- (c) about 0.4 to 1,000 moles of water for each mole of NCO.
- 2. The mixture according to claim 1 wherein the aromatic amine scavenger is 2,6-diethylcyclohexyl isocyanate.
- 3. The mixture according to claim 1 wherein the aromatic amine scavenger is cyclohexyl isothiocyanate.
- 4. A mixture for preparing polyurethane foams having a reduced aromatic amine content comprising
- A. a member of the group consisting of:
- 1. the reaction product of aromatic isocyanate capped prepolymers consisting of a mixture of
- (a) an aromatic isocyanate capped hydrophilic polyoxyethylene diol, said diol having an ethylene oxide content of at least 40 mole percent;
- (b) an aromatic isocyanate capped polyol having a hydroxyl functionality in the range 3 to 8 prior to capping; said isocyanate capped polyol being present in an amount in the range 2.9 to 50% by weight of (a) and (b); and
- (c) 0.5 to 10.0% by weight of (a) and (b) of an aromatic polyisocyanate having an isocyanate functionality in the range 2.0 to 3.0; and
- 2. an aromatic polyisocyanate and a polyol selected from the group consisting of polyethers and polyesters;
- B. 0.01 to 15% by weight of said group member A. of an aromatic amine scavenger selected from the group consisting of cyclohexyl monoisothiocyanate and a hindered cycloaliphatic monoisocyanate of the general formula: ##STR6## wherein R.sub.1 -R.sub.7 are members of the group consisting of H, alkyl, cycloalkyl, aryl, alkaryl, aralkyl or mixtures thereof wherein the alkyl groups contain 1-8 carbon atoms, the cycloalkyl groups contain 4-8 carbon atoms and the aryl groups contains 6-14 carbon atoms with the proviso that where R.sub.3 is a group member other than H, R.sub.1, R.sub.2, R.sub.4 and R.sub.5 can be H and with the further proviso that where R.sub.3 is H at least two of R.sub.1, R.sub.2, R.sub.4 and R.sub.5 are group members other than H and x is 1 to 7; and
- C. about 0.4 to 1,000 moles of water for each mole of NCO.
- 5. The mixture according to claim 4 wherein the aromatic amine scavenger is 2,6-diethylcyclohexyl isocyanate.
- 6. The mixture according to claim 4 wherein the aromatic amine scavenger is cyclohexyl isothiocyanate.
- 7. A crosslinked hydrophilic foam having a three-dimensional network comprising the reaction product of
- A. isocyanate capped prepolymers consisting of a mixture of
- (1) an isocyanate capped hydrophilic polyoxyethylene diol, said diol having an ethylene oxide content of at least 40 mole percent; and
- (2) an isocyanate capped polyol having a hydroxyl functionality in the range 3 to 8 prior to capping; said isocyanate capped polyol being present in an amount in the range 2.9 to 50% by weight of (1) and (2);
- B. 0.5 to 10% by weight of A and B of an aromatic polyisocyanate having an isocyanate functionality in the range 2.0 to 3.0;
- C. 0.01 to 15% by weight of A and B of an aromatic amine scavenger selected from the group consisting of cyclohexyl monoisothiocyanate and a hindered cycloaliphatic monoisocyanate of the general formula: ##STR7## wherein R.sub.1 -R.sub.7 are members of the group consisting of H, alkyl, cycloalkyl, aryl, alkaryl, aralkyl or mixtures thereof wherein the alkyl groups contain 1-18 carbon atoms, the cycloalkyl groups contain 4-8 carbon atoms and the aryl groups contain 6-14 carbon atoms with the proviso that where R.sub.3 is a group member other than H, R.sub.1, R.sub.2, R.sub.4 and R.sub.5 can be H and with the further proviso that where R.sub.3 is H at least two of R.sub.1, R.sub.2, R.sub.4 and R.sub.5 are group members other than H and x is 1 to 7; and
- D. 6.5 to 390 moles of water for each mole of unreacted isocyanate.
- 8. The hydrophilic foam according to claim 7 wherein the aromatic amine scavenger is 2,6-diethylcyclohexyl isocyanate.
- 9. The hydrophilic foam according to claim 7 wherein the aromatic amine scavenger is cyclohexyl isothiocyanate.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of copending application having Ser. No. 831,628, filed Sept. 8, 1977, now abandoned, which in turn is a continuation-in-part of Ser. No. 728,464, filed Sept. 29, 1976, now abandoned. The subject matter of said parent applications is hereby expressly incorporated by reference into the present application.
US Referenced Citations (13)
Foreign Referenced Citations (4)
Number |
Date |
Country |
2234507 |
Feb 1973 |
DEX |
2000741 |
Sep 1969 |
FRX |
476 |
Jun 1968 |
ZAX |
1323955 |
Jul 1973 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Wood-Hydrophilic Polyurethane Foam System-Jour., Cellular Plastics, Sep./Oct., 1976, pp. 285-288. |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
831628 |
Sep 1977 |
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Parent |
728464 |
Sep 1976 |
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