PROCESS FOR PREPARING A LIQUID CONCENTRATE FOR POLYMERIC MATERIALS STABILIZATION

The concentrate containing 30 up to 70 weight percent of mixture closed to the compounds with a general formula (I), where the symbols R1 and R2 are of the same meaning or of the different one and they mean alpha methyl benzyl or alpha dimethylbenzyl, the symbol x means integer in a value of 0 up to 2 and the symbol y means integer in a value of 0 up to 3 and this mixture is soluble in 70 up to 30 % of softener, while this softener consists of the mixture closed to aromatic and/or naphthenic hydrocarbons, is being prepared based on the alyklation of diphenylamine with styrene or with the mixture of styrene and alpha methyl styrene, at the temperature of 80 up to 120 Celsius degrees, while bleaching clay is present and acting as the catalyst, however the ration of diphenylamine and styrene is 1 : 1,5 up to 2,0. Water contained in the product, carried in that process by the used bleaching clay, however this product is created as a result of the reaction mixture filtration, is removed with the use of vacuum distillation, and the filtration cake is prepared which consists of the part closed to the reaction product and of the used catalyst, this cake is washed at the temperature of 80 up to 180 Celsius degrees, at the pressure of 2,5 up to 40 kPa, with the use of softener in a multiply excess (3 up to 8) related to the reaction product quantity contained in the filtration cake, and the such colature is mixed with the above mentioned isolated reaction product and softener, while water was removed of this cake before this mixing started. Water carried in this process also can be removed with the use of the vacuum distillation closed the starting the starting consisting of diphenylamine and bleaching clay, before feeding of styrene is started and the rest of water can be removed based on the distillation closed to the resulted reaction mixture, while the used catalyst can be removed of it. The liquid concentrate is applied to stabilise polymers, related to caoutchouc family especially, to prevent the thermic or thermo-oxidising degradation.