| 摘要 |
PROBLEM TO BE SOLVED: To provide an easy-to-manufacture drilling work cover plate for improving drilling position accuracy. SOLUTION: The cover plate 1 is such that a water-soluble lubricating layer 3 is formed on at least the single face of an aluminum substrate 2. The lubricating layer 3 is an extrusion coat layer of a water-soluble resin composition containing ethylene oxide-propylene oxide copolymer. The copolymerization rate of the propylene oxide to the ethylene oxide-propylene oxide copolymer is 0.1-20 mass%. The number average molecular weight of the ethylene oxide-propylene oxide copolymer is 10,000 or greater. The melt flow rate of each of the ethylene oxide-propylene oxide copolymer and the water-soluble resin composition measured at a testing temperature of 125C° and a testing load of 21.18 N is 0.1-100 g/10 min. COPYRIGHT: (C)2011,JPO&INPIT |
