Claims
- 1. A method for formation of a thermodynamically stable mixture of photoactive compounds that are multiesters of polyhydroxy phenols and a naphthoquinone diazide sulfonyl halide, said method comprising the steps of dissolving a phenol having at least two free phenolic hydroxyl groups and an o-naphthoquinone diazide sulfonyl halide in an aprotic solvent in the presence of a strong base, there being at least one mole of said naphthoquinone diazide sulfonyl halide per mole of phenol, reacting said phenol with said o-napthoquinone diazide sulfonyl halide until essentially all of said o-naphthoquinone diazide sulfonyl halide is reacted with said polyhydroxy phenol, and following completion of said reaction, adding a second reactant selected from the group consisting of a naphthoquinone diazide sulfonic acid ester of a phenol having ester groups in an amount differing from the number of ester groups substituted on said multiester formed by said reaction, an unesterified polyhydroxv phenol, a non-light sensitive ester of a phenol and combinations thereof, and permitting the product to remain in said solvent for a period of time of at least 15 minutes before recovering said photoactive compounds.
- 2. The method of claim 1 where the polyhydroxy phenol, initially reacted with the o-naphthoquinone diazide sulfonyl halide corresponds to the following formula: ##STR4## where R.sup.1 is a member selected from the group consisting of hydrogen, halogen, lower, alkyl having from 1 to 4 carbon atoms, or hydroxyl; R is a member selected from the group consisting of hydrogen, hydroxyl, and ##STR5## where X is a single C--C bond, --O--, --S--, --SO.sub.2 --, --C--, or --(CR.sup.2.sub.2)-- where each R.sup.2 is individually selected from the group consisting of hydrogen, lower alkyl having from 1 to 4 carbon atoms, mononuclear aryl or ##STR6## where each R.sup.1 is as defined above.
- 3. The method of claim 1 the phenol is a hydroxybenzophenone.
- 4. The method of claim 3 where the phenol is a trihydroxybenzophenone.
- 5. The method of claim 1 where the ratio of naphthoquinone diazide sulfonic acid groups to free hydroxyl groups does not exceed 20 to 1.
- 6. The method of claim 5 where the ratio varies between 10 to 1 and 1 to 1.
- 7. The method of claim 1 where the solvent has a polarity index of at least 3.5.
- 8. The method of claim 7 where the polarity index is at least 4.0.
- 9. The method of claim 1 where the pK.sub.a of the base is at least 9.0.
- 10. The method of claim 1 where the reaction is conducted at a temperature ranging between 20.degree. C. and 40.degree. C.
Parent Case Info
This application is a continuation of copending application Ser. No. 08/614,279 filed on Mar. 12, 1996 and which designated the U.S.
US Referenced Citations (12)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0 443 820 A2 |
Aug 1991 |
EPX |
0 554 101 A1 |
Aug 1993 |
EPX |
0 555 861 A1 |
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Continuations (1)
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Number |
Date |
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Parent |
614279 |
Mar 1996 |
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