Abstract: Flaky alumina particles including mullite in a surface layer of the flaky alumina particles. A method for producing flaky alumina particles including forming a mixture by mixing together an aluminum compound that contains elemental aluminum, a molybdenum compound that contains elemental molybdenum, and silicon or a silicon compound that contains elemental silicon, the aluminum compound being in an amount greater than or equal to 50 mass %, calculated as Al2O3, the molybdenum compound being in an amount less than or equal to 40 mass %, calculated as MoO3, the silicon or the silicon compound being in an amount of 0.5 mass % or greater and less than 10 mass %, calculated as SiO2, relative to a total mass of the flaky alumina particles taken as 100 mass %; and firing the mixture.

Abstract: A piperidine compound represented by the following general formula (I) and a stabilized polymeric material composition containing said compound.A[(O--X).sub.n NH--Y].sub.m (I)(wherein A represents a residue formed by eliminating m hydroxyl groups from a polyhydric (tri- to hexa-hydric) alcohol; X represents an alkylene group having 2 to 4 carbon atoms; n is an integer of from 1 to 15; m is an integer of from 3 to 6; and Y represents a group: ##STR1## wherein R.sub.1 represents a hydrogen atom, an alkyl, alkoxy or acyl group having 1 to 18 carbon atoms or an oxygen free radical; and R.sub.2 represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.

Abstract: A piperidine compound represented by the following general formula (I) and a stabilized polymeric material composition containing said compound.A[(O-X).sub.n NH-Y].sub.m (I)(wherein A represents a residue formed by eliminating m hydroxyl groups from a polyhydric (tri- to hexa-hydric) alcohol; X represents an alkylene group having 2 to 4 carbon atoms; n is an integer of from 1 to 15; m is an integer of from 3 to 6; and Y represents a group: ##STR1## wherein R.sub.1 represents a hydrogen atom, an alkyl, alkoxy or acyl group having 1 to 18 carbon atoms or an oxygen free radical; and R.sub.2 represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.