- Piperidyl organosiloxanes and polymer substrates light-stabilized therewith
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Novel piperidyl organosiloxanes, well adapted for the light/UV-stabilization of a wide variety of polymer substrates, e.g., polyolefins and polyalkadienes, have the structural formula (I): STR1
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- Process for the preparation of polyalkyl-1-oxa-diazaspirodecane compounds
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The invention relates to a process for the preparation of polyalkyl-1-oxa-diazaspirodecane compounds, which can be used as highly active light stabilizers for polymers. The reaction is carried out in a solvent mixture of at least one alcohol and if appropriate an inert organic solvent in the presence of solid alkali metal hydroxide or a corresponding amount of a mixture of solid alkali metal hydroxide and water as the sole catalyst. The process offers the advantage that, by using a solvent mixture and dispensing with a phase transfer catalyst, a higher rate of reaction and therefore higher product quality with the same yield are achieved. By dispensing with a phase transfer catalyst, which remains in the waste water and must be disposed of expensively, and by the reusability of the solvent mixture, the process is more environment-friendly and more economical than processes known to date.
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- Process for preparing organic esters and amides and catalyst system therefor
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Disclosed is a process for the preparation of organic esters and amides by reacting (a) a 5 to 60 mole % excess of an ester of (substituted-4-hydroxyphenyl) alkanoic acid with (b) (i) a C4 -C20 aliphatic alcohol or thioether alcohol having one or more hydroxyl groups or (ii) an amine of the formula, (R"')2 N(CH2)n R"" wherein R"' is hydrogen, C1-7 alkyl, C5-12 cycloalkyl, or C6-12 aryl, provided that one R"' is hydrogen, and R"" is hydrogen or N(R"')2 wherein R"' is a defined above, in the presence of a catalyst system comprising a basic inorganic compound and a polar aprotic organic compound. The process provides higher yields of the desired product, shorter reaction times, and reduces the production of undesirable side-products.
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