| 摘要 |
The present invention pertains to an entry sheet for drilling, said sheet having excellent hole positioning accuracy, even in high temperature conveyance and/or storage environments. The present invention particularly pertains to an entry sheet for drilling which is characterised by being formed by the formation of a water-soluble resin composition layer on at least one surface of a metal support foil, said composition containing a water-soluble resin, a water-soluble lubricant, and 2, 7-naphthalenedisulfonic acid, 3-hydroxy-4-[(4-sulfo-1-naphthalene) azo]-, and trisodium salt (Red No. 2). Said water-soluble resin composition layer is formed by being cooled from a cooling initiation temperature of 120-160°C to a cooling completion temperature of 25-40°C in no more than 60 seconds and at a cooling speed of at least 1.5°C/second, with the degree of crystallisation of the water-soluble resin composition being at least 1.2, and the standard deviation(s) of the surface hardness of the water-soluble resin composition layer being no more than 2, and the surface hardness being 8.5N/mm2-20N/mm2. |
