Polyvinyl cinnamate

Fig. 4. Wedge spectrograms of unsensitized (1) and picramide sensitized (2) polyvinyl cinnamate)...

Resists as different as naturally occurring colloids (such as gelatin, albumin, and shellac) or synthetic polymers (such as polyvinyl alcohol, polyacrylics, polyvinyl pyrrolidone, and polyvinyl hutyral) rendered photosensitive by dichromate or other means, as well as synthetic photosensitive polymers such as polyvinyl cinnamates (Kodak positive resists), diazonaphthoquinone/novolac, and solid-film resists such as Riston (introduced by Dupont in 1968) have all been used in PCB fabrication. Some of these resists are still being used today. 

Cinnamoyl chloride is reacted with polyvinyl alcohol (PVA) and produces polyvinyl cinnamate ... 

Polyvinyl cinnamate gives crosslinking of the cyclobutane ring by irradiation, as shown in Equation (1.109). Polyvinyl cinnamate absorbs UV light near 280 nm. Therefore, polyvinyl cinnamate shows sensitivity to visible light. Triplet sensitizers such as Micheler s ketone and 5-nitroacenaphthene are effective to extend sensitivity to visible light. 

FIGURE 3.73 Polyvinyl cinnamate. deflection temperature, and solvent resistance. 

E. D. Kvasnikov, V. M. Kozenkov, and V. A. Barachevskii, Birefringence in polyvinyl cinnamate films, induced by polarized light. Dokladi Akademii Nauk SSSR 237, 633 (1977) (in Russian). 

To avoid the formation of surface walls and to provide a fast switching ofF time, the anchoring energy should be sufficiently high, e.g. > 10 " J/m, comparable with that of the rubbed polymer surface. This is not really observed for polyvinyl-cinnamate (PVCN) derivatives [27-29]. The recent measurements also confirm that 10 to 10 J/m, i.e. about one to two orders of mapitude smaller than the required value [1]. The in-plane sliding mode (IPSL) was proposed in a... 

The present invention relates to an alignment layer, and more particularly to an alignment layer with photo-sensitive material selected from the group consisting of a pyranose polymer, a furanose polymer, polyvinyl cinnamate, polysiloxane cinnamate, polyvinyl alcohol, polyamide, polyimide, polyamic acid and silicone dioxide. 

Sometimes several purposes can be served at once. Chlorination of natural rubber decreases the flammability of the polymer. At the same time, it raises the 7 so that the polymer can be used as a binder for traffic paints. Nitration of cellulose allows the native cotton to be plasticized and molded. Flammability is enhanced at the same time. This may be a disadvantage to makers of molded articles for decoration and apparel. However, the munitions manufacturer regards the flammability and propellant power of guncotton, cellulose nitrate, as its most important advantage. Most often a polymer modification is economically justifiable only when the original polymer occurs naturally or as a by-product. Sometimes modification is the only good way to make a material. A case in point is the photosensitive polymer polyvinyl cinnamate. 

Rayon, cellophane Cellulose acetate Cellulose nitrate Hydroxy ethyl cellulose Carboxy methyl cellulose Ethyl cellulose Methyl cellulose Polyvinyl alcohol Polyvinyl butyral Polyvinyl formal Brominated butyl rubber Polyvinyl cinnamate Cellulose nitrate (guncotton) Chlorinated rubber Graft copolymer... 

Non-silver photosensitive materials had long been known using synthetics or colloids such as fish glue with a sensitizer. Kodak had much of the early PWB market with their KPR and KMER Liquid resists based on polyvinyl cinnamate chemistry. These were the photoresists of choice in the early days, but under production conditions they were slow photographically and uniform coatings free of pinholes were difficult to achieve. 

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