26275-88-7

Process for the preparation of modified zinc oxide nanoparticles, which comprises reacting zinc oxide nanoparticles, which are dissolved in a solvent, in the presence of ammonia or amines with a tetraalkyl orthosilicate and optionally with an organosilane, with the proviso that the reaction takes place at a content of less than 5% by weight of water, based on the total amount of solvent and water. Modified zinc oxide nanoparticles which have Si—O-alkyl groups and are soluble in organic solvents, obtainable by this process for the preparation. Liquid or solid formulations which comprise modified ZnO nanoparticles. Inanimate organic materials, for example plastics or coatings, which comprise modified ZnO nanoparticles. Method of stabilizing inanimate organic materials against the effect of light, free radicals or heat, where modified ZnO nanoparticles, which optionally comprise UV absorbers and/or stabilizers as further additives, are added to the materials.

The present invention relates to an ultraviolet absorber for synthetic resins composed of a triazine compound represented by the general formula (I) shown below (wherein R represents an alkyl group having 1 to 4 carbon atoms, n is 0 or an integer of up to 2, and X represents a group selected from the consisting of group (a) to (d) shown below) (wherein R1 represents an aliphatic group having 5 to 60 carbon atoms, which is an alicyclic group, an alkyl group having an alicyclic group at the terminal or in the chain thereof, an alkyl group having a branch, or a linear alkyl group, depending on the number of carbon atoms; R2 represents an alkyl group having 1 to 18 carbon atoms or a (poly)alkyleneoxyalkyl group; R' represents an aliphatic diyl group having 5 to 60 carbon atoms; R and n have the same meanings as those described in the general formula (I) above).

A wide variety of hindered amine compounds are effective as antioxidant stabilizers to prevent the oxidation of liquid hydrocarbons and of oxygenated compounds, such as sulfolane or tetraethylene glycol, used as extraction solvents in the petroleum industry.

The mild reduction of the nitroxides 1a-j to the corresponding sterically hindered amines 2a-j by means of ethyl mercaptane is reported.The reaction mixtures of 1a,b,g were analyzed by glc/ms.

The present invention relates to a piperidine derivative represented by the general formula (I), STR1 wherein R1 and R2 independently represent a hydrogen atom or a C1 -C3 alkyl or C2 -C20 acyl group, R3 represents a hydrogen atom or a C1 -C20 alkyl, C6 -C20 aryl, C7 -C20 aralkyl or C2 -C20 acyl group, and l represents 1 to 3, and a stabilizer for organic substances containing said piperidine derivative as an effective ingredient.

Polymeric polyesters containing a 2,2,6,6-tetralkyl piperidine moiety in the repeating unit are disclosed as light stabilizers for polymers subject to degradation by ultra-violet light.