| 摘要 |
<p>PURPOSE:To reduce the loss of a lubricant even in a high temperature and high humidity atmosphere by forming a protection layer, containing aromatic keton as well as a compound which has a bond with a lubricous atomic group at, to the least, either the principal chain terminal or the side chain of a molecules and an ester bond with acrylic acid or methacrylic acid at the other, at the circumferential edge of a center hole. CONSTITUTION:The protection layer is formed containing the compound which has the bond with the lubricous atomic group at, to the least, either the principal chain terminal or the side chain of a molecule and the ester bond with acrylic acid or methacrylic acid at the other, and aromatic keton which operates as a photopolymerization initiator by absorbing ultraviolet rays, and polymerized and set by ultraviolet-ray irradiation to obtain an extremely good result. Both compounds are coated to 2-50g/m<2>, preferably 5-30, and further preferably 10- 20g/m<2> thickness. The coating thickness after the polymerization and setting by the ultraviolet-ray irradiation is 1-50mum, preferably 5-30mum, and further preferably 10-20mum.</p> |
