Claims
- 1. A visible-light sensitive photohardenable composition comprising a free radical addition polymerizable or crosslinkable material and a photobleachable ionic dye-counter ion compound, said compound being capable of absorbing visible light and producing free radicals which initiate polymerization or crosslinking of said material.
- 2. The photohardenable composition of claim 1 wherein prior to exposure, said ionic dye-counter ion compound is a stable, non-transient compound.
- 3. The photohardenable composition of claim 1 wherein said ionic dye-counter ion compound is soluble in said free radical addition polymerizable or crosslinked compound.
- 4. The photohardenable composition of claim 3 wherein following exposure of said ionic dye-counter ion compound to light, an electron is transferred from said dye to said counter ion or from said counter ion to said dye and the rate of said electron transfer is greater than a diffusion controlled rate.
- 5. The photohardenable composition of claim 1 wherein said compound is an anionic dye compound.
- 6. The photohardenable composition of claim 5 wherein said anionic dye is selected from the group consisting of xanthene and oxonol dyes.
- 7. The photohardenable composition of claim 6 wherein said ionic dye counter ion compound is an anionic dye-onium ion complex or an anionic dye-pyryllium ion complex.
- 8. The photohardenable composition of claim 7 wherein said dye is a xanthene dye.
- 9. The photohardenable composition of claim 1 wherein said ionic dye counter ion compound is a cationic dye-borate anion compound represented by the formula (I): ##STR3## where D is a cationic dye moiety; and R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different and selected from the group consisting of alkyl, aryl, aralkyl, alkaryl, alkenyl, alkynyl, alicyclic, heterocyclic, and allyl groups.
- 10. The photohardenable composition of claim 9 wherein said cationic dye is selected from the group consisting of cationic methine, polymethine, triarylmethane, indoline, azine, thiazine, xanthene, oxazine, and acridine dyes.
- 11. The photohardenable composition of claim 10 wherein said cationic dye is selected from the group consisting of cationic cyanine, carbocyanine, hemicyanine, rhodamine, and azamethine dyes.
- 12. The photohardenable composition of claim 11 wherein said polymerizable or crosslinkable material contains an ethylenically unsaturated compound.
- 13. The photohardenable composition of claim 12 wherein at least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is an alkyl group.
- 14. The photohardenable composition of claim 13 wherein R.sup.1, R.sup.2, and R.sup.3 are aryl groups and R.sup.4 is an alkyl group.
- 15. The photohardenable composition of claim 7 wherein said photobleachable ionic dye-counter ion compound is a complex of Rose Bengal or Rose Bengal benzyl ester with a diphyliodonium ions.
- 16. The photohardenable composition of claim 9 wherein said cationic dye is an azine dye.
- 17. The photohardenable composition of claim 16 wherein said azine dye is Methylene Blue.
- 18. The photohardenable composition of claim 16 wherein said cationic dye is selected from the group consisting of ##STR4##
- 19. A process for coating a substrate with an essentially colorless radiation curable composition which comprises coating said substrate with a visible light sensitive composition comprising a free radical addition polymerizable or crosslinkable material and a photobleachable ionic dye-counter ion compound capable of absorbing visible light and generating free radicals; exposing said composition to light to harden said composition; and bleaching said ionic dye to an essentially colorless state.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 944,305, filed Dec. 18, 1986 which in turn is a continuation-in-part of Ser. No. 860,367, filed May 6, 1986, abandoned, which is a continuation-in-part of Ser. No. 800,014, filed Nov. 20, 1985, abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4307182 |
Dalzell et al. |
Dec 1981 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
0039162 |
Oct 1980 |
JPX |
Continuation in Parts (3)
|
Number |
Date |
Country |
Parent |
944305 |
Dec 1986 |
|
Parent |
860367 |
May 1986 |
|
Parent |
800014 |
Nov 1985 |
|