| 摘要 |
1,267,798. Electrical insulating tape. BEIERSDORF A.G. 23 Dec., 1970 [24 Dec., 1969], No. 61175/70. Heading B2E. [Also in Division C3] An electrical insulating tape comprises a flexible carrier having a layer of pressure sensitive adhesive thereon of a copolymer comprising (a) 65-90% by weight, or total monomers, of one or more esters of acrylic acid with straight or branched chain primary or secondary alcohols of 4-12 carbon atoms, (b) 10-30% by weight of one or more N-vinyl lactams of formula where n=3,4 or 5 and (c) 0-20% of a further comonomer. The monomers of Group (a) are preferably present in amount 75-85% and preferred examples are n-butyl acrylate and/or 2-ethylhexyl acrylate. Preferred examples of the Group (b) monomers are N-vinyl pyrrolidone, N-vinyl piperidone and N-vinyl caprolactams. The Group (c) monomers exemplified are acrylic, methacrylic, maleic, fumaric or itaconic acid esters and vinyl acetate. The carrier material may be a plastic foil such as a polyvinyl chloride, polyethylene glycol terephthalate or a polycarbonate, textiles, foam materials or asbestos and glass fibre cloths. |
