Abstract: Adhesive sheet particularly for sealing vessels and channels in which chemical, biological or biochemical reactions are conducted, composed of a backing film coated on one side with a pressure-sensitive adhesive, characterized in that the adhesive sheet has a transmittance of at least 89% (in the wavelength range between 450 to 750 nm) and a HAZE value of not more than 3% and the surface of the pressure-sensitive adhesive has a surface roughness Ra of not more than 0.03 ?m and Rz of not more than 0.10 ?m, the refractive index of the pressure-sensitive adhesive being less than 1.55, and the difference in the refractive indices of pressure-sensitive adhesive and of backing film being not more than 0.1.

Abstract: Use of a paper carrier containing groundwood pulp as a carrier web for release lacquer coatings, the proportion of the groundwood pulp in the composition of the paper carrier being at least 5% by weight, preferably at least 20% by weight, the paper carrier having a density of from 0.9 to 1.3 g/cm3, preferably 1.0 to 1.3 g/cm3, the paper carrier having an upper side and a lower side, it being possible for the paper carrier to be provided on the upper side and/or on the lower side with a coating of polyolefin or of an inorganic substance, and an anti-adhesive layer being applied to one of the two coatings that may be provided.

Abstract: Process for preparing crosslinked pressure ensitive adhesives, in which a plyacrylate is prepared by the free radical copolymericzation of a monomer mixture , the polyacrylate is then concentrated and the concentrated polyacrylate is reacted with further monomers having functional groups and subsequently crosslinking.

Abstract: The invention relates to a method for the production of cross-linked acrylate contact adhesive materials characterised in that polyacrylates are firstly produced from the following monomers by free-radical (co-)polymerisation: (d) acrylic and methacrylic acid monomers with the following structure, where R1═H or CH3 and R2=an alkyl chain with 2-20 C atoms, at a proportion of 45 99.5 wt. % of the monomer mixture, (e) one or several carboxylic acid anhydrides, containing olefinic double bonds, at a proportion of 0.5-25 wt. % of the monomer mixture, (f) further unsaturated olefinic monomers containing functional group A, at a proportion of 0-30 wt. % of the monomer mixture. The polymers thus produced are concentrated to give a polyacrylate material with a solvent content ≦2 wt.