Printing photopolymer plate

Synthesis and Properties of Photopolymer Printing Plates for a Printing Master Plate by Modification of Polyvinyl Alcohol... 

A number of photopolymer printing plates are already known. Their basic structures are to combine one of the general purpose resins such as cellulose (1), polyamide (2J, polyester, poly urethane (3j, polyvinyl alcohol (4), synthetic rubber (5) and the like with photopolymerizing vinyl monomer, photopolymerization initiator and so on. Any one of the plates of such structures can be used as a press plate, but they can not be used as an original plate for duplicate plate owing to their insufficient hardness, toughness and the similar negative properties. 

Therefore, metal plates have been conventionally used. We have performed the research and development of a photopolymer printing plate for a master plate with a new basic structure by combining an oligomer of urea structure having a polyvinyl base with polyvinyl alcohol, photopolymerization initiator and other ingredients. The result shows that the newly developed plate (6) is so good that it has replaced metal plates and has been stably used at leading newspaper companies in Japan where several millions of newspapers are daily issued. 

Figure 4. Structure of photopolymer printing plate for duplicate plate. ( ) The plate of the present development (hereafter referred to as the Photopolymer Plate).

Merigraph. pieicules] Photopolymer printing plate system. 

Meiigrapli. [Hercules] Photopolymer printing plate systan. 

The earliest reports on the use of photoinitiated polymerization for the purpose of imaging were hy Eggert et al. in 1938, Morton in 1949, and Oster ° in 1957. Plamheck invented the photopolymer printing plate probably sometime... 

Solubility modifications. The first commercial photopolymer system introduced in 1959 was the photopolymer printing plate based on the difference in solubility which results in a photo-polymerizable layer on exposure to actinic light relief Images can be obtained by washing out the unpolymerized parts. The photo-polymerizable layer consists of a binder, a monomer, and a photoinitiator. This layer is mounted on an aluminum, a steel, or a polyester support and covered by a removable polyester sheet which protects the plate before use. Before Imagewlse exposure, the... 

Polyester-styrene resins have a low raw material price and are used in wood finishing. Disadvantages are the presence of volatile styrene and the low cure speed. Products with methacrylic groups are used where line (cure) speed is less important, mainly in combination with acrylates in special end uses (e.g., in the electronics industry and in photopolymer printing plates) to improve adhesion or to obtain specific physical properties. Thiol- thiene mixtures can lead to very flexible cured films but their odor seriously limits their use. 

CAS 1189-08-8 EINECS/ELINCS 214-711-0 Uses Crosslinking monomer for preparation of inks, photoresists for printed circuit boards, photopolymer printing plates, wire and cable coalings reactive diluent for PVC plastisols, rubber crosslinking, glass reinforc plastics, adhesives, sealants, impregnated wood composites, and other surf, coatings... 

Uses Crosslinking agent for rubber vulcanization, moisture barrier films and coatings, photopolymer printing plates and letterpress inks, conversion coatings and adhesives crosslinked actylic/vinyl resin comonomer syn. resin modifier plastisols photosensitive resins textile modifier... 

Uses Pigment wetting agent for adhesives, barrier coatings, conformal coatings, electronic solder masks, photopolymer printing plates, sealants... 

In addition to acrylated systems, two other technologies bear mentioning. A mercaptan - olefin (thiol/ene) system was developed by W. R. Grace [11] in the early 70 s. This system is primarily used to make photopolymer printing plates. It is estimated that over half the newspapers in the U.S. are printed using plates produced by this process. High cost has limited growth of thiol/ene in other applications. 

Photopolymer printing plates are available from three big suppliers see [AGF 14, FUJ 14, KOD 14]. 

Johansson, C., Johnson, J., and Jarnstrdm, L (March 2001) Photopolymer printing plates Changes in performance and properties, Flexo and Gravure IntemationaL... 

Japanese Patent (Toray Industries), Photopolymer Printing Plate Precurser, Its Manufacturing Method of Plastic Letterpress Printing Plate Using It. JP 2005326442. 

The typical letterpress photopolymer printing plate has a surface tension of approximately 18-35 mN/m, depending on its fluoropolymeric make-up. Typical plate compositions include polytetrafluoroethylene, or a copolymer of tetrafluoro-ethylene and hexafluoropropylene. The low surface tension of the plate allows for better print quality with the types of substrates the plate comes in contact with because of an enhanced transfer of letterpress inks to these substrates. The characteristics of these inks and the adhesion mechanisms required will be discussed next. 

A printing plate cylinder (steel). A photopolymer printing plate is attached to the plate cylinder. The printing plate s raised surface replicating the image contacts the substrate to transfer ink... 

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