Bayer Aktiengesellschaft

Gerhard Hohmann

Rudiger Musch

Manfred Dollhausen

Wolfgang Konter

Peter Wendling

Eberhard Muller

Ludwig Mott

Herbert Bartl

Helmut Waniczek

Rudolf Casper

Rolf Dhein

Rolf-Volker Meyer

Heinrich Alberts

Hans Rudolph

Rudiger Schubart

Wilhelm Gobel

Gottfried Pampus

Hans-Jurgen Pettelkau

Karl-Heinz Schabel

Winfried Behr

The polymerization of chloroprene leads to non-colored products when a mixture of 2.0 to 5.0% by weight of a salt of disproportionated abietic acid and 0.1 to 1.0% by weight, in each case relative to the total amount of monomer, of a compound of the formula ##STR1## in which R.sub.1 and R.sub.2, independently of one another, denote hydrogen or CH.sub.3,

Process for polymerization of chloroprene

Storage-stable polychloroprene is obtained, by aqueous emulsion polymerization, using xanthogen disulphides as molecular weight regulators, when a peptizing agent is added after the end of the polymerization.

Process for the preparation of polychloroprene

Storage-stable polychloroprene is obtained, using a polymerization initiator comprising a mixture of

Polymerization of chloroprene

Gel-free polychloroprene is obtained, at high monomer conversions, using a polymerization initiator comprising sodium dithionite or a mixture of sodium dithionite with formamidinesulphinic acid or with potassium peroxydisulphate or with formamidinesulphinic acid and potassium peroxodisulphate or with potassium peroxodisulphate and sodium anthraquinon-.beta.-sulphonate or with formamidinesulphinic acid and potassium peroxodisulphate and sodium anthraquinone-.beta.-sulphonate, and in the presence of oxygen and a chain transfer agent when 30 to 90% of the initiator is present at the commencement of polymerization and the remainder is added in portions during the polymerization, only further sodium dithionite being added at a conversion &gt;60% in the case of an initiator combination, and when 20 to 80% by weight of the total amount of chain transfer agents is present before or at the commencement of polymerization and the remaining amount is added in one or more parts at monomer conversions of greater than 20%.

The invention relates to the use of grafted ethylene-vinylacetate copolymers (EVA-copolymers) for the production of hotmelt adhesives.

Use of grafted ethylene-vinylacetate copolymers for the production of

An improved process of polymerizing an aqueous emulsion of chloroprene monomer stabilized with phenothiazine wherein polymerization is initiated in the presence of phenothiazine stabilizer and molecular oxygen with a polymerization initiator comprising sodium dithionite.

Polymerizing phenothiazine stabilizer chloroprene in the presence of an

The present invention relates to new thermoplastic contact adhesives. They have high heat resistance and bond strength.

Thermoplastic contact adhesives containing epoxide plasticizers

By adding substances corresponding to the following general formula I ##STR1## in which X=O, S or N--R.sub.5 ; R.sub.1 =hydrogen, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.19 -alkenyl, phenyl, C.sub.1 -C.sub.4 -alkylene phenyl, C.sub.5 -C.sub.12 -cycloalkyl or C.sub.5 -C.sub.12 -cycloalkenyl; R.sub.2 =hydrogen, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.12 -alkenyl, phenyl or C.sub.1 -C.sub.4 -alkylene phenyl; R.sub.3 =hydrogen, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.19 -alkenyl, phenyl, C.sub.1 -C.sub.4 -alkylene phenyl, acryl formyl or acetyl; R.sub.4 and R.sub.5 =same or different, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.19 -alkenyl, phenyl, C.sub.1 -C.sub.4 -alkylene phenyl, acryl, C.sub.5 -C.sub.12 -cycloalkyl or C.sub.5 -C.sub.12 -cycloalkenyl; R.sub.4 and R.sub.5 may also form a C.sub.4 -C.sub.7 -ring which may optionally contain an oxygen atom in ether form and the radicals R.sub.1 and R.sub.2 may form a C.sub.5 -C.sub.12 -alkylene bridge or a C.sub.5 -C.sub.12 -alkenylene bridge, the radicals R.sub.1 and R.sub.4 may form a C.sub.2 -C.sub.9 -alkylene bridge and the radicals R.sub.1 and R.sub.3 may form a C.sub.3 -C.sub.10 -alkylene bridge; where R.sub.1 and R.sub.2 are attached, the ring formed may be bridged by a C.sub.1 -C.sub.4 -alkylene bridge and the ring systems formed may be substituted by the radical R.sub.6 which represents hydrogen, C.sub.1 -C.sub.5 -alkyl or C.sub.2 -C.sub.5 -alkenyl, in quantities of from 0.05 to 3% by weight, based on 100 parts by weight of monomer, to the aqueous emulsion polymerization of chloroprene at the beginning of the reaction, during or after polymerization, but at the latest before the residual monomers are removed, high-viscosity polychloroprenes characterized by excellent processing behaviour and product properties are obtained.

Process for the production of high molecular weight polychloroprene and

Ester-modified polyamides containing of from 50 to 80% by weight of --HN--(CH.sub.2).sub.5 --CO units are obtained by reaction of .gamma.-caprolactam and mixtures of dicarboxylic acids, primary diamines and polyalkylene glycols and are suitable inter alia as hot melt adhesives and for the elastification of thermoplastic materials.

Ester-modified polyamides

Storable polychloroprene adhesives can be produced by polymerizing chloroprene in a manner known per se in the presence of a dialkylxanthogen disulphide reacting 50 to 90% of the monomer and dissolving the polymer thus obtained in an organic solvent to obtain viscosities in the range of 10 to 100 poises.

Storable polychloroprene adhesives and a process for their production

The polymerization of chloroprene in the presence of an inorganic peroxy compound, anthraquinone-2-sulphonic acid-alkali salt and formamidine sulphinic acid.

Process for the polymerization of chloroprene

An adhesive consisting substantially of a modified olefine polymer, a chlorinated olefine or diene polymer, an alkylated polyphenyl, an aromatic polynitroso compound and an organic solvent or solvent mixture.

Heat-sealing adhesives

Adhesive consisting substantially of a modified olefine polymer, a chlorinated olefine or diene polymer, an alkylated polyphenyl sulphone, an aromatic polynitroso compound and an organic solvent or solvent mixture.

Growing community of inventors

Leverkusen, Germany

Gerhard Hohmann