Sumitomo Rubber Industries Limited

Toshio Kamada

Seiji Tomono

Toshikazu Ogita

Tetsuya Fuchikami

Makoto Sugiya

Yasuhiko Kondo

Yuji Yamasaki

Tsuneo Masuda

A method is furnished for producing a compressible layer for a printing blanket by heating a sheet-shaped intermediate layer of a rubber composition having a structure in which hollow microspheres are dispersed in matrix rubber for one to fifty minutes under certain defined conditions of vulcanizing pressure and temperature using a vulcanizer for applying heat and pressure in direct contact with the intermediate layer. The produced compressible layer exhibits superior compressibility and durability, is uniform in thickness and internal structure, and does not reduce the productivity of the printing blanket and increase the fabrication cost of the printing blanket.

Method of producing a compressible layer for a printing blanket

The offset blanket of the present invention has a structure comprising no reinforcing layer between its compressive layer and its surface printing layer. The surface printing layer has a thickness in the range of 5 to 20% based on the thickness of the whole blanket, and a hardness of the rubber which constitutes the surface printing layer which is in the range of 40.degree. to 70.degree. Type A, JIS K 6301. The compressive layer has a foam content (void volume) in the range of 30 to 60% and a thickness in the range of 10 to 30% based on the thickness of the whole blanket and a hardness of the rubber matrix constituting the compressive layer which is in the range of 40.degree. to 80.degree. Type A, JIS K 6301. Therefore, the offset blanket of the present invention is superior in paper feeding properties. Further, misregistry can be inhibited and solid inking properties are not deteriorated.

Printing offset blanket

The printing offset blanket in accordance with the present invention has a surface printing layer made of a mixture of silicone rubber and oil-resisting rubber. It is therefore possible to prepare ink layers having a uniform thickness and clear edges. Further, the present offset blanket can be improved in paper discharging properties and retention of paper powder, enabling the blanket to be suitably applied to high-speed printing, filter or display prints, or the like. The printing rubber roll of the present invention is made of a mixture of silicone rubber and oil-resisting rubber. Accordingly, the present rubber roll is excellent in stability with respect to ultraviolet-curing ink and can therefore be used for a long period of time.

Printing offset blanket and rubber roll

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Akashi, Japan

Toshio Kamada