Abstract: Mixtures of high molecular weight polyisobutylene and thermoplastic polymers are prepared in an extruder by a process in which meterable, high molecular weight polyisobutylene is first metered into the extruder and homogenized in at least one kneading stage, heated and subjected to controlled molecular weight degradation and the thermoplastic polymer is then introduced into the polyisobutylene melt by means of a side feed and is subsequently homogenized together with said melt. The novel process is particularly suitable for the preparation of mixtures of high molecualr weight polyisobutylene and polyethylene.

Abstract: Carboxyl-containing isobutene copolymers are obtainablea) by cationic polymerization of a mixture of from 1 to 99 mol % of isobutene and from 99 to 1 mol % of a 2-methylalk-1-ene at less than 20.degree. C. in the presence of a halogen-containing Lewis acid andb) subsequent grafting of the isobutene copolymer obtainable in this manner with an .alpha.,.beta.-ethylenically unsaturated carboxylic acid or carboxylic acid derivative at above 100.degree. C. and in the presence of a free radical initiator.Such carboxyl-containing isobutene copolymers are particularly suitable as adhesive raw materials or as sealing compounds.

Abstract: Carboxyl-containing isobutene copolymers are obtainablea) by cationic polymerization of a mixture of from 1 to 99 mol % of isobutene and from 99 to 1 mol % of a 2-methylalk-1-ene at less than 20.degree. C. in the presence of a halogen-containing Lewis acid andb) subsequent grafting of the isobutene copolymer obtainable in this manner with an .alpha.,.beta.-ethylenically unsaturated carboxylic acid or carboxylic acid derivative at above 100.degree. C. and in the presence of a free radical initiator.Such carboxyl-containing isobutene copolymers are particularly suitable as adhesive raw materials or as sealing compounds.

Abstract: A process for regulating the reaction in the preparation of polyisobutylene by polymerizing isobutylene at from -130.degree. to 0.degree. C. in the presence of from 0.01 to 1.0% by weight of a Friedel-Crafts catalyst, from 0.0001 to 0.1% by weight of a molecular weight regulator, and a low boiling point solvent that is inert under the reaction conditions, the percentages by weight being based in each case on isobutylene, in which the solvent that has evaporated in the polymerization is continuously removed, liquefied and recycled in the liquid state to the polymerization zone, wherein vinyl ethers are used as molecular weight regulators. The vinyl ether used in this process acts both as an accelerator and an inhibitor of the cationic polymerization.

Abstract: A process for reducing the size of polyisobutene with a molecular weight of from 5,000,000 to 12,000,000 by grinding under pressures of from 1 to 50 bar and with average residence times of from 0.1 to 30 minutes entails the grinding being carried out at from 0.degree. to 60.degree. C.

Abstract: The conversion is increased in the preparation of polyisobutylene by polymerization of isobutylene in a polymerization zone at from 0.degree. to -130.degree. C. in the presence of from 0.01 to 1.0% by weight of a boron trifluoride catalyst, from 0.001 to 1.0% by weight of a molecular weight regulator and from 30 to 90% by weight of a low-boiling solvent which is inert under the reaction conditions, by a process in which the content of but-1-ene in the monomeric isobutylene is kept constant at from 1.9 to 2.1, in particular 2.0, % by weight.

Abstract: A process for the preparation of polyisobutylene by polymerizing isobutylene in a polymerization zone which is at from 0.degree. to -130.degree. C., by means of from 0.01 to 1.0 percent by weight of boron trifluoride catalyst, in the presence of a primary or secondary alcohol as polymerization accelerator and in the presence of from 30 to 90% by weight of a low-boiling solvent which is inert under the reaction conditions, wherein the solvent vaporized during the polymerization is continuously drawn off, liquefied and recycled, in the liquid state, to the polymerization zone, and wherein the boron trifluoride catalyst used contains less than 0.3, in particular less than 0.01, percent by volume of silicon tetrafluoride and the solvent, which is preferably ethylene, is recycled not less than twice but not more than 36 times during the continuous polymerization.

Abstract: A process for coating moldings of plastics which tend to stick together at room temperature by applying solutions containing a nonadhesive resin of (1) a copolymer of at least one member of the group consisting of styrene and methylstyrene and a monoester of at least one member of the group consisting of maleic and fumaric acid or (2) a reaction product of at least one member of the group consisting of cyclohexanone and methylcyclohexanone with formaldehyde or acetaldehyde, said non-adhesive resin having a monoscope yield point or more than 80.degree.C. and a ball indentation hardness of from 310 to 800 kp/cm.sup.2 at 10 seconds and thereafter evaporating the solvent at a temperature which is lower than the softening point of the material to be coated.

Abstract: Production of a homogeneous mixture of plastics materials in powder form by subjecting a molten inhomogeneous mixture of two or more plastics to a maximum shear velocity of from 10.sup.4 to 10.sup.8 sec.sup.-.sup.1 for from 10.sup..sup.-2 to 10.sup..sup.-6 seconds; the pulverulent mixtures obtained are used in rotary sintering and injection molding.