DRILLING MASK Russian patent published in 2014 - IPC B26F1/16 B23B35/00 

FIELD: process engineering.

SUBSTANCE: invention relates to mask for drilling holes in laminar material. Said mask comprises metal foil with the ply of polymer composition applied thereon by lamination. Polymer comprises contains 30-85 wt % of water-soluble polymer (A) with mean molecular weight of 80000-400000, 10-60 wt % of polyethylene glycol (B) with average molecular weight of 15000-25000, 5-50 wt % of water-soluble lubricating polymer (C) and 0.1-5 wt % of at least one of water-soluble substances (Y) in terms of 100 wt % of mix (X) consisting of water-soluble polymer (A), polyethylene glycol (B) and water-soluble lubricating polymer (C). Water-soluble substances (Y) are selected from the group consisting of polyalcohol, amino acid derivatives of alcohols, organic salts and salts of organic acids.

EFFECT: notable decrease in hole wall roughness and amount of polymer wound on drill.

5 cl, 2 tbl, 6 ex