Claims
- 1. A method for making a urea-formaldehyde polyamine compound for use in curing epoxy resins, comprising the steps of
- (a) reacting urea and paraformaldehyde in a lower alcohol under basic conditions and well above room temperature,
- (b) adding acid to make the reaction strongly acidic, with resulting exotherm,
- (c) holding the reaction at about 70.degree.-120.degree. C. for about an hour, and
- (d) bringing the pH to about 7.0,
- (e) removing the resulting urea-formaldehyde monomer, consisting mainly of urea-formaldehyde ether monomer, from the remaining material,
- (f) reacting each mole of the urea-formaldehyde ether monomer with about two to about four moles of an aliphatic, cycloaliphatic, or aromatic polyamine to split the ether group of the urea-formaldehyde ether molecule and form a carbon-nitrogen bond to an amine group at a site of the ether splitting.
- 2. The method of claim 1 wherein the urea-formaldehyde monomers include some methylol groups, comprising in step (f) also reacting the methylol groups with the polyamine.
- 3. The method of claim 2 wherein step (f) starts at about room temperature, rising somewhat due to exotherm.
- 4. The method of claim 2 followed by (g) distilling off the alcohol and water of reaction, to give a low-viscosity transparent liquid.
- 5. The method of claim 1 wherein step (f) starts at about room temperature rising somewhat due to exotherm.
- 6. The method of claim 1 followed by (g) distilling off the alcohol and water of reaction, to give a low-viscosity transparent liquid.
- 7. The method of claim 1, where the polyamine is ##STR26## where X.sup.1 is ##STR27## and X.sup.2 is X.sup.1 or ##STR28## where R.sup.1 is one of the following, ##STR29## x varying from about 2 to about 6 ##STR30## where X+Y+Z=5.3 ##STR31## where a+c=3.5 and b=13.5 ##STR32## R.sup.2 and R.sup.3 are both H where R.sup.1 is any of (a) to (o) and when R.sup.1 is (p), either R.sup.2 or R.sup.3, but not both, is C.sub.18 H.sub.35, while the other is H, and
- R.sup.4 is H or an alkyl radical with one to nine carbon atoms.
- 8. A method for making a thiourea-formaldehyde polyamine compound suitable for use in curing epoxy resins, comprising the steps of:
- (a) reacting thiourea and paraformaldehyde in a lower alcohol under basic conditions and and well above room temperature,
- (b) adding acid to make the reaction strongly acidic, with resulting exotherm,
- (c) holding the reaction at about 65.degree. to 120.degree. C. for about an hour, and
- (d) bringing the pH to about 7.0,
- (e) removing from the remaining material the resulting thiourea-formaldehyde monomer consisting mainly of thiourea-formaldehyde ether monomer,
- (f) reacting each mole of the thiourea-formaldehyde ether monomer with about two to about four moles of an aliphatic, cycloaliphatic polyamine or an aromatic polyamine to split the ether group of the thiourea-formaldehyde ether molecule and form a carbon-nitrogen bond to an amine group at the site of the ether splitting.
- 9. The method of claim 8 wherein the thiourea-formaldehyde monomers include some methylol groups, comprising in step (f) also reacting the methylol groups with the polyamine.
- 10. The method of claim 9 wherein step (f) starts at about room temperature, rising somewhat due to exotherm.
- 11. The method of claim 9 followed by (g) distilling off the alcohol and water of reaction, to give a low-viscosity transparent liquid.
- 12. The method of claim 8 wherein step (f) starts at about room temperature, rising somewhat due to exotherm.
- 13. The method of claim 8 followed by (g) distilling off the alcohol and water of reaction, to give a low-viscosity transparent liquid.
- 14. The method of claim 8 wherein the polyamine is hexamethylene diamine.
- 15. A method for making a phenolic substituted urea-formaldehyde polyamine compound suitable for use in curing epoxy resins, comprising the steps of:
- (a) reacting urea, an alkyl phenol having from 1 to 9 carbon atoms, and paraformaldehyde in a lower alcohol under basic conditions and well above room temperature,
- (b) adding acid to make the reaction strongly acidic, with resulting exotherm,
- (c) holding the reaction at about 65.degree.-120.degree. C. for about an hour, and
- (d) bringing the pH to about 7.0,
- (e) removing the resulting alkyl-phenol substituted urea-formaldehyde ether monomer from the remaining material,
- (f) reacting each mole of the alkyl-phenol substituted urea-formaldehyde ether monomer with about two to about four moles of an aliphatic or cycloaliphatic polyamine to split the ether group of the substituted urea-formaldehyde molecule and form a carbon-nitrogen bond to an amine group at the site of the ether splitting.
- 16. The method of claim 15 wherein the substituted urea-formaldehyde used in step (a) is nonyl phenol.
- 17. The method of claim 16 wherein step (f) starts at about room temperature, rising somewhat due to exotherm.
- 18. The method of claim 16 followed by (g) distilling off the alcohol and water of reaction, to give a low-viscosity transparent liquid.
- 19. The method of claim 16 where the polyamine in step (f) is hexamethylene diamine.
- 20. The method of claim 15 wherein the polyamine in step (f) is oleyl diamine.
- 21. The method of claim 15 wherein step (f) starts at about room temperature, rising somewhat due to exotherm.
- 22. The method of claim 15 followed by (g) distilling off the alcohol and water of reaction, to give a low-viscosity transparent liquid.
- 23. The method of claim 15 where the polyamine in step (f) is hexamethylene diamine.
- 24. A method for making a urea-formaldehyde amine compound suitable for use in curing epoxy resins, comprising the steps of:
- (a) reacting urea and paraformaldehyde in a lower alcohol under basic conditions and well above room temperature,
- (b) adding acid to make the reaction strongly acidic, with resulting exotherm,
- (c) holding the reaction at about 70.degree.-120.degree. C. for about an hour, and
- (d) bringing the pH to about 7.0,
- (e) removing the resulting urea-formaldehyde ether monomer from the remaining material,
- (f) reacting one mole of the urea-formaldehyde ether monomer with about four moles of monoethanol amine to split the ether group of the urea-formaldehyde ether molecule and form a carbon-nitrogen bond to an amine group at the site of the ether splitting.
Parent Case Info
This application is a division of application Ser. No. 06/656,140, filed Sept. 28, 1984, now U.S. Pat. No. 4,574,145, which is a continuation-in-part of application Ser. No. 396,319, filed July 8, 1982; now U.S. Pat. No. 4,490,510.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
3931110 |
Freeman et al. |
Jan 1976 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
656140 |
Sep 1984 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
396319 |
Jul 1982 |
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