Abstract: The compressor of the present invention has a structure in which a groove is disposed on a sealing surface of at least one of the head and the valve plate. The structure enhances contact pressure on a pressed surface, providing the gasket with preferable sealing strength. Besides, the head of the compressor has no protrusion on the edge. This eliminates worry about breakage of the head, providing high reliability and productivity.

Abstract: Disclosed is a forgery prevention sheet comprising a multi-layered sheet having at least two layers, wherein there are first and second print patterns at different positions in thickness of the sheet, the first print pattern being formed with a first ink including a first fluorescer and the second print pattern which is different from the first print pattern being formed with a second ink including a second fluorescer.

Abstract: Disclosed is a forgery prevention sheet comprising at least triple-layered construction including a base (2) and outer layers (1) and (3) formed on both side of said base. The outer layers have opacity of 20-92%, preferably of 40-92%. The inner surface of at least one (1) of the outer layers is printed with a fluorescent pigment ink into a predetermined design pattern. The printed pattern is not visible under the sunlight, but becomes visibly luminous to human's naked eye, when the sheet is irradiated with ultraviolet rays from the top and from the bottom. The sheet has no fluorescent ink on or near the top surface and, therefore, provides good printability when subjected to post-printing process with any printing system including a lithographic offset printing press, a laser printer and a thermal transfer printer.

Abstract: This invention relates to a transparent plastic printing film suitable for offset printing or letterpress printing where an oil ink of the oxidative polymerization type is used. An ink-setting layer composed principally of a rubbery resin and/or styrene resin is provided on at least one side of a transparent plastic film, whereby the transparent plastic printing film permits lithographic offset or the like without losing the transparency of the film. Fine ruggedness may be formed on at least one side of the transparent plastic printing film. The transparent plastic printing film may also be subjected to an antistatic treatment. Sheet-fed printing making use of the above film does not develop blocking, tacking, scratch abrasion, etc. The above-described various properties have been improved further in a transparent plastic printing film provided with an ink-setting layer, which has been formed by coating a mixture of (i) a solution of the rubbery resin and/or styrene resin and (ii) a silica sol.