Abstract: A synthetic polymer composition stabilized against photo- and thermal-deterioration thereof wherein there is incorporated, in a sufficient amount to prevent such deterioration, 1-substituted piperidine derivatives.

Abstract: Piperidine-spiro-hydantoin derivatives having the formula ##SPC1##Wherein X represents oxygen atom or sulfur atom; n is an integer of 1 to 4 inclusive, and R represents various aliphatic or aromatic groups depending on the value of n.These compounds (I) are useful as stabilizers against photo and thermal deterioration of various synthetic polymers and can be prepared, for example, by reacting the corresponding 3-unsubstituted piperidine-spiro-hydantoin compound with the halide R-(X.sub.1).sub.n in which R and n are as defined herein and X.sub.1 is a halogen atom.

Abstract: A process for preparing triacetonamine, characterized in that acetonine is reacted with acetone in the presence of at least 12.5 mol % based on acetonine of an acid catalyst under anhydrous conditions. Triacetonamine is used as an intermediate for light stabilizer for synthetic polymers.

Abstract: A process for preparing triacetonamine characterized in that acetonine is reacted with water in the presence of at least 12.5 mole % based on acetonine of an acid catalyst.Triacetonamine is used as an intermediate for light stabilizer for synthetic polymers.

Abstract: Piperidine derivatives having the formula ##SPC1##WhereinR' represents an alkyl group, a substituted alkyl group, an acyl group, an alkoxycarbonyl group, a substituted alkoxycarbonyl group, an amino group, a substituted amino group, or nitroso group;X represents oxygen atom or sulfur atom;Y represents oxygen atom, sulfur atom or a group of the formula = N -- R" in which R" is hydrogen atom, an alkyl group or a substituted alkyl group;Z represents oxygen atom or a group of the formula >N -- R'" in which R'" is hydrogen atom, an alkyl group or a substituted alkyl group;n is an integer of 1 through 4 inclusive; andR represents, when n is 1, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a cycloalkyl group, an alkoxycarbonyl group, a substituted alkoxycarbonyl group, a substituted phosphino group or a substituted phosphinyl group, when n is 2, an alkylene group, an alkenylene group, an arylene group, a substituted arylene group, an aralkylene group; an alkylenediphenylene g

Abstract: 4-Piperidone ketal derivatives of the formulae ##SPC1##And ##SPC2##Wherein R.sub.1 represents an alkyl group of 1 to 8 carbon atoms and R.sub.2 represents an alkylene group of 2 or 3 carbon atoms or o-phenylene group and they are prepared by reacting triacetonamine with a monohydric alcohol of the formulaR.sub.1 --OH (III)wherein R.sub.1 is as defined above or a dihydric alcohol or phenol of the formulaR.sub.2 --(OH).sub.2 (IV)wherein R.sub.2 is as defined above in the presence of an acid catalyst. They are useful as statilizers against deterioration of synthetic polymers.

Abstract: Piperidine derivatives having the formula ##SPC1##WhereinR' represents an alkylene group which may be interrupted with an oxygen or sulfur atom, an alkenylene group, an alkynylene group, an aralkylene group, an aliphatic diacyl group, a group of the formula ##EQU1## IN WHICH N IS AN INTEGER OF 1 OR 2 AND X is an alkylene group, or o-, m- or p-phenylene group or the carbon atoms of CO groups may be directly joined in the absence of X or a group of the formula ##EQU2## in which Y is an alkylene group or O-, m- or p-phenylene group; R represents hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, an alkoxycarbonylalkenyl group, an aliphatic, aromatic or heterocyclic monoacyl group, a N-substituted carbamoyl group, a N-substituted thiocarbamoyl group or a monovalent radical derived from an oxoacid;R.sub.1 and R.sub.2 individually represent a lower alkyl group or they jointly represent, together with the oxygen atoms, a group of the formula ##SPC2##In which R.sub.

Abstract: 4-Piperidone derivatives having the formulae ##SPC1##Wherein R represents a phenyl or naphthyl group which may be substituted with nitro, lower alkyl, halogen, hydroxyl, lower alkyl hydroxy, hydroxy lower alkyl or formyl or a 5- or 6-membered heterocyclic group having as a hetero atom at least one of oxygen atom, sulfur atom and nitrogen atom and R.sub.1 represents hydrogen atom or an alkyl group of 1 to 4 carbon atoms. They are useful as stabilizers for various synthetic polymers against their photo- and thermal-deteriorations and the 4-piperidone derivatives (II) are prepared from the corresponding 2,2,6,6-tetramethyl-4-oxopiperidine derivatives by reaction with an aldehyde and the 4-piperidone derivatives (I) are prepared from the 4-piperidone derivatives (II) through dehydration.