Photopolymerizable compositions and

The photopolymerizable composition can be used both as liquids to coat a substrate with light sensitive films and as dry photoresist films. In the latter case, the photoresist is a trilayer pie consisting of a top layer made of poly (ethylene terephthalate), a middle layer being the photopolymerizable composition, and an underlayer made of polyethylene. The underlayer is removed before exposure and the remained bilayer composite is laminated onto a clean substrate. The article is prebake to anneal a polymer layer and to enhance adhesion to the substrate. The selective exposure by the UV light through the top layer hardens the exposed areas of the photoresist. After exposure, the top layer is removed and the photoresist layer... 

Scranton et patented Thick, Composite Parts Made from Photopolymerizable Compositions and Methods for Making Such Parts, in which photopolymerization was combined with thermal FP. 

Matsumoto, H. Takashima, M. Washisu, S. Kawamura, K. Sorori, T. Photopolymerizable compositions and their recording materials. Jpn. Kokai Tokkyo Koho JP 2001209176, 2001 Chem. Abstr. 2001, 135, 160144. 

U.S. 3,622,334. Photopolymerizable Compositions and Elements containing Heterocyclic Nitrogen-Containing Compounds. E. I. Du Pont de Nemours and Company (November 23,1971). 

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. 

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

Liquid thioxanthones, for example, 631 and 632, have been synthesized in order to improve formulation of photopolymerizable compositions <1998W09842697> and thioxanthones possessing either cationic 633 <1998W09853369> or anionic 634 <2000MI212> hydrophilic substituents have been prepared and successfully employed for curing water-based ink formulations. The mode of action of the latter ionic compounds appears to involve both the lowest excited triplet and singlet states . 

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. 

Figure 3.71. Optical system used for 3D microfabrication using TP initiated polymerization of a photopolymerizable composition. The numerical aperture of the objective lens is 0.85 (magnification of 40), the accuracy of the galvano-scanner set and the dc motor scanner were 0.3 and 0.5 pm, the beam power at peak in the photocrosslinkahle composition is about 3 kW, with a repetition rate of 76 MHz and a pulse width of 130 fs at a wavelength of 770 nm [76].

Chemical nature of photoresists, the chemistries involved in the photolithography, the properties of photoresists are briefly described. The discussion includes diazonaphthoquinone/novolac positive photoresists, polymer-aromatic diazide negative photoresists, photopolymerizable compositions, chalcogenide glass using systems, chemically amplified photoresists, and photoresists with an image formation in a thin layer. 

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. 

The key component of a photopolymerizable composition is a photoinitiator. This compound can absorb UV radiation and then produce a pair of radicals, either by dissociation (a photoinitiator of the I type) ... 

Eujiknra, S. Iwasaki, M. Maeda, M. Wada, M. Photopolymerizable compositions for production of printing plates and photoresists. Ger. Offen. DE 3926667, 1990 Chem. Abstr. 1990, 113, 106446. 

U.S. 4,963,458. Image Forming Method and Material Using Photopolymerizable Composition. 

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. 

U.S. 5,096,790. Process of Forming Hologram and Polymeric Holographic Recording Medium with Sensitizer. E. I. Du Pont de Nemours and Company (March 17, 1992). A new class of sensitizers for photopolymerizable compositions is disclosed derived from cyclic ketones and tricyclic aminoaldehydes. A preferred compound is cyclopentanone, 2.5-bis[(2,3,6,7-tetrahydro-lH,5H-benzo[i,j]quinolizin-9-yl)methylene]. 

Because a patent does not give the owner of a patent the right to practice the invention, a patent owned by another party may prevent an inventor from practicing his or her own invention. In the example given above, the composition of matter patent on the dye would dominate all uses of the dye. If the composition of matter patent on the dye were owned by one party and the patents on the use of the dye in photopolymerizable compositions were owned by a different party, neither could practice the invention without the consent of the other. The owner of the patents on the use of the dye in photopolymerizable compositions would be unable to practice the invention without infringing the composition of matter patent. And the owner of the composition of matter patent would be unable to use the dye in photopolymerizable compositions without infringing the patent on the use of the dye in photopolymerizable compositions. 

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