Abstract: The strength of the bond between a metal and vulcanized rubber may be increased by a bonding agent containing at least one organic cobalt compound and at least one boric acid ester.

Abstract: Phenolic resins obtained by condensation from alkylphenol, aldehyde, polyamine and polyether in a molar ratio of 1:0.7 to 1.3:0.005 to 0.2:0.001 to 0.3 are suitable as tackifiers for rubber mixtures.

Abstract: A vulcanization system consisting of(a) 20-50 parts by weight of sulphur or 20-50 parts by weight of a sulphur donor,(b) 20-50 parts by weight of an accelerator of the mercapto or sulphenamide group,(c) 0-10 parts by weight of a conventional accelerator additive, and(d) 20-50 parts by weight of a compound corresponding to the general formula (i): ##STR1## wherein R.sub.1 to R.sub.5 are identical or different and denote hydrogen, halogen, nitro, cyano, CF.sub.3, CCl.sub.3, carboxyl, an alkoxy group containing 1-4 C-atoms in the alkyl part, or a C.sub.1 -C.sub.4 alkyl group but the groups R.sub.1 -R.sub.5 must not all be hydrogen;x represents 1-4, preferably 2-3,y represents 0 or 1, andZ denotes divalent groups such as ##STR2## C.sub.1 -C.sub.12 alkylene, C.sub.4 -C.sub.12 cycloalkylene, C.sub.6 -C.sub.10 arylene or C.sub.8 -C.sub.12 arylalkylene, andR.sub.6 denotes the group corresponding to the formula: ##STR3## wherein R.sub.1 -R.sub.5 have the meaning indicated above and may all be hydrogen;C.sub.1 -C.sub.

Abstract: A mixture comprising sulphur or a sulphur donor, a mercapto- or sulfenamide vulcanization accelerator, a compound containing a thiophenyl radical and a standard auxiliary accelerator is used as a vulcanization system for natural or synthetic rubber.

Abstract: A mixture of azodicarbonamide and an .alpha.-amidosulphone corresponding to the general formula: ##STR1## in which R represents hydrogen, a C.sub.1 -C.sub.4 -alkyl residue and/or halogen,x represents numbers from 0 to 5,y represents numbers from 1 to 3, corresponding to the valency of R.sub.1,R.sup.1 represents an aromatic carboxylic acid residue or sulphonic acid residue with 6 carbon atoms, which is optionally substituted once or several times by halogen, C.sub.1 -C.sub.4 alkyl residues, C.sub.1 -C.sub.4 alkoxy residues, nitro and/or cyano, or represents an aliphatic carboxylic acid residue or a sulphonic acid residue with 1-4 carbon atoms, a carbonic acid residue, a thiocarbonic acid residue or a phosphoric acid residue which, corresponding to the numerical value of y, contains 0-2 phenoxy residues or C.sub.1 -C.sub.4 alkoxy residues optionally substituted with C.sub.1 -C.sub.4 alkyl or halogen,R.sup.2 represents R.sup.1, or hydrogen, a C.sub.1 -C.sub.4 alkyl residue, a C.sub.5 -C.sub.

Abstract: Cyclic acetals which may be obtained by reacting tri- to hexa-ols with tetrahydrobenzaldehydes can be used as non-discoloring stabilizers for natural and/or synthetic rubber against ozone attack.

Abstract: Sulphenamides are obtained by reacting N-chlorothiophthalimide with compounds containing one or two olefinic double bonds. These products retard vulcanization of natural or synthetic rubber.

Abstract: Alkyd resin lacquers which contain cellulose nitric acid esters can be prevented from "lifting" and yellowing by the addition of bis-[hydroxyphenyl]-alkanes which are substituted in the nucleus.

Abstract: A vulcanization system for natural and/or synthetic rubber containing light fillers comprising certain silanes, thiazoles, guanidines, and thiurams. By using this system the extremely unpleasant odor of silanes when used alone can be substantially diminished without affecting the properties of the vulcanizate.