Claims
- 1. A process for preparing cellular polymeric structures which comprises mixing an acidulous or acidic polymerizable medium that is polymerizable and/or cross-linkable by a free radical mechanism with an effective amount of an acid sensitive mono- or poly-azo compound containing the group: ##EQU2## wherein Y is an acid sensitive group which in the presence of an acidulous or acidic polymerizable medium causes sufficient decomposition of the azo compound that gas is released in said medium and during said decomposition said mono- or poly- azo compound promotes polymerization and/or cross-linking of said medium to provide a matrix that is sufficiently polymerized and/or cross-linked that the generated gases cause the matrix to expand, each of the remaining valences being satisfied by an organic radical; provided that any carbon atom that is directly linked to an azo nitrogen, except that of a carbonyl group, has at least two of its remaining three valences satisfied by a carbon to carbon bond or a carbon to hydrogen bond.
- 2. The process of claim 1 further characterized in that an adjuvant free radical initiating agent is used in addition to said acid sensitive azo compound further to promote polymerization and/or cross-linking of said medium.
- 3. The process of claim 1 further characterized in that acidity is supplied to said medium by adding an acidic promoter thereto.
- 4. The process of claim 1 wherein said medium comprises a polymer integrally containing an acidic function and no added acidic promoter is supplied thereto.
- 5. The process of claim 1 wherein the sole source of heat other than ambient temperature is that of the exotherm generated by the reaction of said acid sensitive azo compound with said acidulous or acidic medium.
- 6. The process of claim 1 further characterized in that heat is supplied to the reaction.
- 7. The process of claim 1 wherein said medium is an ethylenically unsaturated polyester containing a vinyl monomer.
- 8. The process of claim 1 whereby Y is OH, ##STR300## each of R,R.sup.2 and R.sup.3 is the same or different substituent including H, a hydrocarbon radical containing 1 to 18 carbon atoms, such as: alkyl, cycloalkyl, aralkyl, arcycloalkyl, aryl, alkaryl, cycloalkaryl, alkenyl,
- cycloalkenyl, and 5 and 6 membered heterocyclic and benzheterocyclic radical wherein the hetero atoms are selected from oxygen, sulfur and nitrogen, and R and R.sup.2 together may form an alkylene diradical, said hydrocarbon radicals being optionally substituted by a group containing 1 to 18 carbon atoms selected from alkoxy, aryloxy, aroyloxy, alkanoyloxy, alkoxycarbonyl, alkanoyl, aroyl, and carbamoyl, hydroxy, halogen, and cyano;
- when Y is other than OH, R, R.sup.2 and/or R.sup.3 may also be substituted by carboxyl;
- R.sup.1 is a substituted or nonsubstituted hydrocarbon radical containing 1 to 18 carbon atoms such as alkyl, cycloalkyl, arakyl, arcycloalkyl, aryl, alkaryl, or cycloalkaryl, said hydrocarbon radical being optionally substituted by a group containing 1 to 18 carbon atoms selected from t-alkylperoxy-, t-aralkylperoxy, t-cycloalkylperoxy, t-alkylperoxycarbonyl, t-alkylperoxycarbonyloxy, alkanoylperoxy, alkanoylperoxycarbonyl, .alpha.-hydroxyalkylperoxy-.alpha.-hydroxyalkyl, .alpha.-hydroperoxyalkylperoxy-.alpha.-hydroxyalkyl, alkanoylperoxycarbonyloxy, di-(t-alkylperoxy)-methylene, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, alkoxy, cycloalkoxy, aryloxy, alkaryloxy, cycloalkaryloxy, aroyloxy, alkaroyloxy, carbamoyloxy, alkanoyloxy, alkoxycarbonyloxy, cycloalkoxycarbonyloxy, alkaryloxycarbonyloxy, aryloxycarbonyloxy, alkoxycarbonyl, cycloalkoxycarbonyl, aryloxycarbonyl, alkaryloxycarbonyl, alkoxycarbonylamino, cycloalkoxycarbonylamino, aryloxycarbonylamino, alkaryloxycarbonylamino, alkanoyl, aroyl, alkaroyl, carbamoyl, acylamino, aroylamino, alkylamino, arylamino, thioalkanoyl, dithioalkanoyl, thioaroyl, dithioaroyl, alkylthio, arylthio and 5 and 6 membered heterocyclic and benzheterocyclic wherein the hetero atoms are selected from oxygen, sulfur and nitrogen; as well as amino, hydroxy, halogen and cyano;
- R.sup.4 is a substituted or non-substituted divalent hydrocarbon radical of 1 to 20 carbon atoms, such as alkylene, cycloalkylene, arylene, aralkylene, or cycloalkylalkylene, such divalent radicals optionally containing one or tow non-terminal and non-adjacent hetero atoms selected from oxygen, nitrogen, and sulfur in the chain, the substituents borne by R.sup.4 being any of those defined herein for R.sup.1 ;
- R.sup.11 is tertiary alkyl containing 4 to 18 carbon atoms or tertiary aralkyl containing 9 to 18 carbon atoms;
- each of X, X.sup.1, X.sup.2, X.sup.3, X.sup.4 and X.sup.5 is the same or different oxygen or sulfur.
- 9. The process of claim 8 wherein Y is --OH.
- 10. The process of claim 8 wherein Y is ##STR301##
- 11. The process of claim 8 wherein Y is ##STR302##
- 12. The process of claim 8 wherein Y is ##STR303##
- 13. The process of claim 8 wherein Y is R.sup.1 X-.
- 14. The process of claim 8 wherein said azo compound is one having the formula: ##STR304## wherein R.sup.5 is ##STR305## or one of the substituted or nonsubstituted hydrocarbon radicals defined herein for R.sup.1, provided that any substituent borne by R.sup.5 is not linked to the R.sup.5 carbon atom directly attached to an azo nitrogen of FORMULA II; R.sup.12, R.sup.13 and R.sup.14 are same or different radicals as defined for R.sup.1 ;
- R.sup.6 is ##STR306## or one of the substituted or nonsubstituted hydrocarbon radicals defined for R.sup.1 ;
- R.sup.7 is a substituted or nonsubstituted hydrocarbon radicals containing 1 to 18 carbon atoms, such as alkyl, cycloalkyl, aralkyl, and arcycloalkyl wherein the substituent borne by R.sup.7 is selected from the substituents defined in claim 8 for R.sup.1 ;
- R.sup.7 can be hydrogen when Y is --OH or R-C(=O)O;
- R.sup.6 and R.sup.7 may together form a ring with the carbon linked to the azo nitrogen;
- R.sup.7a is the same as R.sup.7 except it is not H;
- R.sup.8 is ##STR307## R.sup.9 is the same as R.sup.6 except it is not any of the azo radicals defined therefor;
- R.sup.10 is lower alkyl (1 to 6 carbon atoms) or cycloalkyl (5 to 6 carbon atoms);
- Y is defined hereinbefore plus ##STR308## Y' is a monovalent group that is the same as Y except Y' is not ##STR309## Y" is the same as Y when Y is divalent; Y" and R.sup.7 taken together with the carbon to the azo nitrogen form a ring containing 4 to 12 atoms;
- R.sup.5a is the same as R.sup.5 except that where R.sup.5 is ##STR310## n is 1 or 2.
- 15. The process of claim 14 wherein Y is --OH.
- 16. The process of claim 15 wherein said azo compound is 2-t-butylazo-2-hydroxypropane.
- 17. The process of claim 15 wherein said azo compound is 2-t-butylazo-2-hydroxybutane.
- 18. The process of claim 15 wherein said azo compound is 1-t-butylazo-1-hydroxycyclohexane.
- 19. The process of claim 14 wherein Y is ##STR311##
- 20. The process of claim 19 wherein said azo compound is 2-t-butylazo-2-(methoxycarbonyloxy)-butane.
- 21. The process of claim 19 wherein said azo compound is 2-t-butylazo-2-(methoxycarbonyloxy)-propane.
- 22. The process of claim 14 wherein Y is ##STR312##
- 23. The process of claim 22 wherein said azo compound is 2-t-butylazo-2-acetoxypropane.
- 24. The process of claim 22 wherein said azo compound is 2-t-butylazo-2-acetoxy-4-methylpentane.
- 25. The process of claim 22 wherein said azo compound is 1-t-butylazo-1-acetoxycyclohexane.
- 26. The process of claim 22 wherein said azo compound is 2,2'-azo-bis-(2-acetoxybutane).
- 27. The process of claim 22 wherein said azo compound is 2,2'-azo-bis-(2-acetoxypropane).
- 28. The process of claim 14 wherein Y is R.sup.1 O--.
- 29. The process of claim 28 wherein said azo compound is 2-t-butylazo-2-methoxypropane.
- 30. The process of claim 28 wherein said azo compound is 2-t-butylazo-2,4-dimethoxy-4-methylpentane.
- 31. The process of claim 28 wherein said azo compound is 2-t-butylazo-2-methoxy-4-methylpentane.
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a Continuation-in-Part of U.S.S.N. 453,446 filed Mar. 21, 1974, and now abandoned.
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Number |
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Date |
Kind |
2576073 |
Krupa et al. |
Nov 1951 |
|
3260688 |
Watanaba et al. |
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3677981 |
Wada et al. |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
453446 |
Mar 1974 |
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