Abstract: The invention relates to a partially cross-linked polyvinyl alcohol, obtained by reacting a polyvinyl alcohol with a polycarboxylic acid, in particular a hydroxypolycarboxylic acid. The partially cross-linked polyvinyl alcohol can be used to produce foils, which have a good water-solubility or water-swelling capacity. Due to this property, such foils can be used as packing material for detergents, cosmetics and the like. According to the invention, the packing dissolves in water, releases its contents or is suitable for releasing (permeation) chemical compounds or agents.

Abstract: Partially cross-linked polyvinyl alcohol is obtained by reaction of a polyvinyl alcohol with a polycarboxylic acid, in particular a hydroxypolycarboxylic acid. This partially cross-linked polyvinyl alcohol can be used to produce films which are readily water soluble or swellable. Owing to this property, such films are very useful as a packaging material for laundry detergents, cosmetics and the like in that the package will dissolve in water and liberate its contents or is suitable for release (permeation) of (active) chemical compounds.

Abstract: A polymeric composition based on PVA is claimed and is substantively composed of

Abstract: Process for cementing semiconductor discs to a carrier plate for subsequent olishing, which comprises applying to the discs a cementing solution being composed of(a) a resin of a melting range between 50.degree. and 180.degree. C. and a melt viscosity between 1000 and 6000 P;(b) a substance acting as plasticizer for the resin at cementing temperatures; and(c) a solvent for the resin and the plasticizer, which evaporizes at cementing temperatures,while avoiding during the application the occlusion of air bubbles between discs and cementing layer, and exerting pressure onto the plates at a temperature between cementing temperatures and 30.degree. C. below the same. The invention also comprises the carrier plate carrying one or more discs cemented thereto by the above process.

Abstract: A process for purifying solid substances by melting and subsequent resoliication, wherein a melted bath of the solid substance is formed, a roller is placed in the bath so that a first portion of its surface is in contact with the melted substance, and the surface of the roller is cooled to a temperature below the melting point of the solid substance. The cooled roller is rotated in the melted substance to collect a solidified film of the substance on the roller surface. A second portion of the roller surface is passed through a heated zone at a temperature above the melting point of the solid substance, so that the solidified film is remelted and collected in an appliance.

Abstract: The invention relates to the preparation of a material more favorably pri that the usual quartz crucible for use in the crucible-pulling of silicon according to Czochralski. To prevent reaction of the crucible wall with molten silicon, the surface of the shaped carbon body is coated by means of chemical vapor deposition first with a carbon-enriched silicon carbide layer and then with a carbon-enriched silicon nitride layer. The carbon-enriched silicon carbide layer is obtained by reacting a gaseous silicon compound with a gaseous carbon compound at a temperature of the shaped carbon body to be coated at 1250.degree. to 1350.degree. C. while the carbon-enriched silicon nitride layer is obtained by reacting a gaseous organosilicon compound with ammonia at a temperature of the shaped carbon body of 1000.degree. to 1200.degree. C.

Abstract: Process for producing large-size, self-supporting plates of silicon deposd from the gaseous phase on a substrate body, which comprises heating a graphite substrate to deposition temperature of silicon, which is deposited on the substrate from a gaseous compound to which a dopant has been added until a layer of about 200 to 650 .mu.m has formed, subsequently melting 40-100% of this layer from the free surface downward, resolidifying the molten silicon by adjustment of a temperature gradient from the substrate body upward, and finally separating the silicon therefrom. The plates so formed are used primarily for making solar cells.

Abstract: A process for producing large-size, substrate-based semiconductor material of silicon deposited on a substrate body from the gaseous phase, which comprises the steps of heating a substrate body by direct current passage to deposition temperature, contacting said body with a gaseous silicon-containing mixture to which a dopant has been added, until a deposit having a thickness from about 10 to 200 .mu.m has been formed, subsequently melting 80 to 100% of the deposited silicon layer from the free surface downward, and resolidifying the molten silicon by adjustment of a temperature gradient from the substrate body upward. Large-sized plates obtained by cutting up the semiconductor material are used as solar cells.

Abstract: A process for making crucible-drawn silicon rods containing volatile doping gents, especially antimony, said rods having narrow resistance tolerances, which comprises drawing from a pre-doped silicon melt a monocrystalline rod while passing through the melt a current of inert gas either intermittently or continuously.

Abstract: Halogenosilanes and halogenogermanes which are contaminated by a boron-coining impurity are purified by treatment with an effective amount of a hydrated metal oxide or a hydrated silicate containing from about 3 to about 8% by weight of water, and then distilling the treated halogenosilane or halogenogermane at a temperature about 3.degree. to about 15.degree. C above its boiling temperature, and at atmosphere pressure.