Photopolymerizable composition containing

Photopolymerizable compositions containing dioxiranyl tetraoxaspiro-[5.5]-undecanes, (VI), were prepared by Chappelow et al. (6) and used as dental restorative materials. 

Dr. Jose L. Pazos in DuPont s Central Research Department worked on a photopolymerizable compositions containing an o-nitroaromatic compound as photoinhibitor. He and the late Dr. George Nacci invented several interesting approaches to improving the hexaarylbiimidazoles system when applied to photopolymer technology. Some of his work could have been applied to color-forming chemistry, but was not. 

U.S. Patent 4,198,242 Photopolymerizable composition containing an o-nitroaromatic compound as photoinhibitor. Pazos Jose F. E. I. Du Pont de Nemours and Company (Wilmington, DE) (Filed June 8, 1978) IPC G03C 002/... 

U.S. 4,168,982. Photopolymerizable Compositions Containing Nitroso Dimers to Selectively Inhibit Thermal Polymerization. Pazos, Jose F. (E. I. Du Pont de Nemours and Company). September 25, 1979. Cl. 430/281.1 430/917 522/16 522/18 522/28 522/63 522/65 522/76 522/121 522/167 Appl. December 7, 1977. Thermally stable photo-polymerizable compositions comprise (i) at least one nongaseous ethylenicaUy unsaturated compound, (ii) a nitroso dimer which is a noninhibitor of free-radical polymerization but thermally dissociates to nitroso monomer which is an inhibitor of free-radical polymerization, and (iii) an organic, radiation-sensitive free-radical generating system. 

Photopolymerizable compositions based on monomeric acryflc or other ethylenicaHy unsaturated acid derivatives are becoming increasingly popular. When multiftmctional derivatives are employed, three-dimensional networks having high strength and abrasion resistance are possible on exposure to light. A typical composition may contain an ethoxylated trimethylolpropane triacrylate monomer, a perester phenacjhdene initiator (69), and an acryflc acid—alkyl methacrylate copolymer as binder. 

Oxman et al. (3) determined that cure speed and enthalpy were improved in photopolymerizable compositions when using anthracene derivatives containing electron donors as photoinitators for cationic curing. Dimethoxy-, diethoxy-, and diphenoxyanthracene were especially preferred. 

Set 1 and Set 2 photopolymerizable monomer compositions containing three or four components prepared and polymerized in this application are illustrated below. 

Photopolymerizable compositions have found their use in the production of thick (5-100 pm) relief images, especially in the field of printed plates and micromachinery. The compositions contain a monomer, matrix polymer (binder), and photoinitiator. The branched monomers are used most frequently. Many photosensitive compounds generating radical and ion centers upon UV irradiation are used as a part of the compositions. Polymethylmethacrylate and its derivatives are very often used as polymer binders. 

TABLE 1. Photopolymerizable Dental Compositions Prepared Containing the Step 1 Product... 

NVK is used as a sensitizer of cationic photopolymerization. Cationically photopolymerizable, or pho-tocurable, compositions typically contain monomers or oligomers having the epoxy or the ether functionality, and a photo-initiator. The most commonly used photo-initiators employed for photoinduced cationic ring-opening polymerizations are diaryliodo-nium salts, or triarylsulfonium salts. 

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