To provide a rubber roller in which the frequency of a printing pressure regulation is small even in the continuous operation of printing and a printing performance is preferably maintained in the roller used for an inking mechanism for a printer.
The rubber roller is formed by using a vulcanized rubber composition in which tanδ when a dynamic change stress (a distance between chucks: 20 mm, at 40°C, initial strain: 2 mm, an amplitude: 50 mm and a frequency: 10 Hz) is applied, is 0.17 or less. The roller is preferably regulated to have a volume change ratio ΔV to the ink of ±15% or less, and a rubber hardness to 40 to 70 IRHD. Since the roller reduces the frequency of a printing pressure regulation such as to regulate a nip width even by providing for printing in a continuous operation, its printing operability is improved. The printing rubber roller is manufactured by selecting the types and blending amounts of a rubber material and a blending drug with the ΔV and the rubber hardness as indexes so that the tanδ value is obtained in the case of preparing the vulcanized rubber composition.
TAJIMA HIROSHI
KAMATA TOSHIO
