Hoechst Aktiengesellschaft

Hans Wilski

Werner Interthal

Friedrich Engelhardt

Gerhard Slebos

Hermann Schmidt

Gunter Gruber

A package for photoresist material, particularly a dry resist, is substantially impermeable to water vapor, thereby preventing humidity-related effects which adversely influence the processability of the photoresist. The package can comprise a film tubing, the ends of which are closed by welding or gluing, into which a photoresist roll is placed. As the material for the film tubing, a composite material can be used which is formed of a polyester film as the support film, to which an aluminum foil is laminated or which is vacuum-metallized with aluminum and a polyethylene film laminated on top. A tinplate container can also be used as a package, the container being closed by soldering after placing the photoresist material inside the container. These packages generally have a permeability to water vapor of less than 0.01 gram of water vapor per square meter per day, at a humidity gradient of 97% and an ambient temperature of 23.degree. C.

Package for dry-resist material

Process for reducing the friction pressure drop of aqueous liquids and suspensions in turbulent or pulsating flow by adding from 1 to 1,000 ppm of linear random copolymers of the following formula I as drag reducing agents ##STR1## in which X is a Na.sup.+, K.sup.+ or NH.sub.4.sup.+ cation and Y is hydrogen or a Na.sup.+, K.sup.+ or NH.sub.4.sup.+ cation, and in which a, b, c and d represent the proportional weight ratios of the comonomers in % and a is in the range of from 30 to 98, b from 0 to 20, c from 0 to 25 and d from 0 to 45, however, wherein the sum of the portions of b and c must be at least 2, the said copolymers being obtained in the manufacturing process in the form of aqueous and dimensionally stable jellies capable of being cut, while retaining their solubility in water.

Drag reducing agents

The frictional drag of aqueous liquids and suspensions in turbulent or pulsating flow is reduced by adding 1 to 1,000 ppm of a polyacryl amide or partially saponified polyacryl amide obtained in its manufacturing process in the form of an aqueous, dimensionally stable jelly which has retained its solubility in water and is capable of being cut.

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Bad Soden am Taunus, Germany

Hans Wilski