| 摘要 |
964,375. Printing processes; dampening rollers. DAYCO CORPORATION. May 7, 1962 [Oct. 16, 1961], No. 17471/62. Heading B6C. [Also in Division F2] A dampening roller comprises an inner layer 12 of hard rubber (80-90 Shore A), a central layer 13 of softer rubber (30-40 Shore A) and an outer layer 14 of rubber having a hardness (50-60 Shore A) about half-way between that of the other layers. The outer layer comprises an hydrophilic plasticizer such as diethylene glycol monobutyl ether formal incorporated in the rubber thereof, which may be butadiene - acrylonitrile copolymer, together with an hydrophilic fibrous material such as rayon flock (8 denier, 1/8 inch) distributed therethrough. In the examples given in the Specification the material of the layer 14 is formed by compounding the following ingredients in various proportions in a mill in conventional fashion-butadiene - acrylonitrile copolymer, zinc oxide, titanium dioxide, brown factice, powdered silica (reinforcing agent), mercaptobenzothiazole sulphide (accelerator), sulphur, rayon flock and diethylene glycol monobutyl ether formal (plasticizer). The fibrous material may be provided in the region of 10% to 25% of the compound by weight whilst the plasticizer may be employed in the range of about 7% to 25% by weight. Specification 495,159 is referred to. |
