DE745032C - Method for producing a synthetic rubber - Google Patents

Description

Process for the production of a synthetic rubber It has been found that valuable polymerization products are obtained if butadiene-i # 3. In a mixture with methyl vinyl ketone in an acidic medium in the presence of oxygen or oxygen-releasing catalysts is subjected to emulsion polymerization, the methyl vinyl ketone being at least in quantities of 25% of the total amount of polymerizable substances (methyl vinyl ketone + butadiene) is present. should be. It is preferred to work at an ordinary temperature or at a moderately elevated temperature. The reaction components are preferably used in the ratio i: i. It is advisable to work in the presence of polymerization regulators. This does not apply to the work belonging to the subject of patent 702 749 using emulsifiers which represent water-soluble salts of compounds of the general formula X-CH2-CH2 = F-CH2-CH2-NZ, in which Y is oxygen or sulfur, NZ is the remainder of one secondary amine or a quaternary ammonium compound, X denotes the radical of a secondary amine, an acid amide, an ester, an ether or a hydroxyl group, where in at least one of the radicals X and Z at least 8 carbon atoms are directly connected to one another in a noncyclic bond.

The polymers available combine good rubber-like properties with excellent resistance (in the vulcanized state) to aliphatic or aromatic hydrocarbons. You stand out in this relationship general class of copolymers of butadienes with unsaturated ketones out (see patent specification 543 343). Example i 25 parts by weight of vinyl methyl ketone and 75 parts by weight of butadiene are in an aqueous emulsion consisting of 3 parts by weight hydrochloric acid dodecylamine or octadecyldimethylamine, zoo parts by weight of water and o, 15 parts by weight of ammonium persulfate, polymerized at 3o °. After i to A polymerization yield of 80% is obtained for two days. - Example 2 50 parts by weight of butadiene are added to a solution of 50 parts by weight Vinyl methyl ketone in 150 parts by weight of a 30 / 0i, -en dodecylamine chlorohydrate solution, which is mixed with 3 parts by weight of 10% ammonium persulfate solution, emulsified and shaken for 3 days at 30 °. A virtually quantitative yield is obtained Polymer, which has good mechanical properties and excellent gasoline and has benzene resistance. Addition of 0.2 parts by weight of diisopropylxanthogen disulfide a polymer of excellent quality is obtained under otherwise identical polymerization conditions plastic properties.

Claims (1)

PATENT CLAIM: Process for the preparation of a synthetic rubber from butadiene hydrocarbons and unsaturated ketones, characterized in that butadiene in a mixture with methyl vinyl ketone in an acidic medium is subjected to emulsion polymerization in the presence of oxygen or oxygen-releasing catalysts, the vinyl methyl ketone being subjected to at least "amounts of 25 °!"" the total amounts of polymerizable substances (vinyl methyl ketone -! - ßudadiene) should be present and working in the presence of emulsifiers which contain water-soluble salts of compounds of the general formula X- CH, -CH.-F- CH.- CH> -NZ represent, wherein 1.` oxygen or sulfur, NZ the radical of a secondary amine or a quaternary ammonium compound, X the radical of a: secondary amine, an acid amide, an ester, an ether or a quaternary ammonium compound or a hydroxyl group, where in at least one the radicals X and Z are at least 8 carbon atoms directly linked to one another in a noncvclic finding. To distinguish the subject of the application from the state of the art, the following publications were considered in the granting procedure: German patent specification .. ... No. 5-3 343 - French - ..... - 803563.