The present application relates to storage-stable plastics additives which are prepared by cooling a mixture of 99.9 to 10% by weight of molten additive material and 0.1 to 90% by weight of crystalline additive material after a shaping process. The shaping process is carried out by forcing the mixture out of a tool provided with die openings, and cooling can be carried out on a cooled conveyor belt. Even after prolonged storage and/or handling, these plastics additives remain free-flowing and do not stick.

The present invention relates to a stabilizer mixture prepared by partially condensing PCl.sub.3 with 2,2'-dimethyl-4,4'-dihydroxy-5,5'-di-tert-butyldiphenyl sulfide, where the phosphorus content is from 2 to 4% by weight and the content of 2,2'-dimethyl-4,4'-dihydroxy-5,5'-di-tert-butyldiphenyl sulfide is from 0.5 to 50% by weight. The stabilizer mixture has very good solubility in organic solvents and in the polymer and has very good stabilizing action.

The present invention relates to novel UV stabilizers of the formula (I) ##STR1## where the substituents are as defined in the description. These compounds are highly suitable for stabilizing organic material, such as plastics, surface coatings, paints and oils, against the action of light, radiation, oxygen and heat.

The present invention relates to plastics comprising a high molecular weight, sterically hindered amine, wherein the sterically hindered amine is at least one amine from the group consisting of I: oligomerized 2,2,4,4-tetramethyl-20(oxiranylmethyl)-7-oxa-3,20-diazadispiro[5.1.11.2]he neicosan-21-one, II: condensation product of 2-chloro-4,6-di(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triaz ine and 1,2-bis(3-aminopropylamino)ethane, and III: condensation product of 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid. These plastics exhibit a reduced rate of uptake of sulfur compounds. The invention further relates to shaped articles made from these plastics.

Polyalkylpiperidine compounds of the formula I ##STR1## in which Y is the group ##STR2## are very effective stabilizers for organic materials.