Gamma-ray stabilizer and thermoplastic polymer compound including the said stabilizer

A thermoplastic polymer composition which comprises 100 parts by weight of a thermoplastic polymer, 0.01 to 10 parts by weight of a benzyl compound (A) selected from the group consisting of the following general formulae (1), (2) and (3)

• wherein, R1 to R11 are each independently selected from the group consisting of a hydrogen atom, alkyl groups having 1 to 5 carbon atoms, cycloalkyl groups having 5 to 6 carbon atoms and aryl groups having 6 to 10 carbon atoms;
• Ar1, Ar3, Ar4, Ar5 and Ar6 are each independently a monovalent aromatic group having 6 to 20 carbon atoms which can have one or more substituents;
• Ar2 is a divalent aromatic group having 6 to 20 carbon atoms which can have one or more substituents;
• p is 0 or 1;
• X is a direct bond or an n-valent organic group having 1 to 20 carbon atoms;
• n is one of the integers of 1 through 5;
• and wherein where n is 1, X is not a direct bond;
• and wherein the one or more substituents for Ar1, Ar2, Ar3, Ar4, Ar5 and Ar6 are selected from the group consisting of an alkyl group, a cycloalkyl group, an alkoxy group, and an acyloxy group, an aralkyl group, an alkoxycarbonyl group, an aromatic group, an acyl group, a cyano group, a nitro group, a carboxyl group, an halogen atom and an hydroxymethyl group;
• and
• a pentaerythritol phosphorous ester (B) having a spirocyclic structure wherein the phosphorous ester (B) is contained at a ratio of 0.01 to 1 part by weight based on 100 parts by weight of said benzyl compound (A).

A gamma-ray stabilizer comprising

• (A) 100 parts by weight of a benzyl compound selected from the group consisting of the following general formulae(1), (2) and (3)
• wherein, R1 to R11 are each independently selected from the group consisting of a hydrogen atom, alkyl groups having 1 to 5 carbon atoms, cycloalkyl groups having 5 to 6 carbon atoms and aryl groups having 6 to 10 carbon atoms;
• Ar1, Ar3, Ar4, Ar5 and Ar6 are each independently monovalent aromatic groups having 6 to 20 carbon atoms which can have one or more substituents;
• Ar2 is a divalent aromatic group having 6 to 20 carbon atoms which can have one or more substituents;
• p is 0 or 1;
• X is a direct bond or is selected from the group consisting of an aliphatic residue having 1 to 20 carbon atoms, an alicyclic residue having 6 to 20 carbon atoms and an aromatic residue having 6 to 20 carbon atoms;
• n is one of the integers 1 through 5;
• and wherein when n is 1, X is not a direct bond;
• and wherein the one or more substituents for Ar1, Ar2, Ar3, Ar4, Ar5 and Ar6 are selected from the group consisting of an alkyl group, a cycloalkyl group, an alkoxy group, an acyloxy group, an aralkyl group, an alkoxycarbonyl group, an aromatic group, an acyl group, a cyano group, a nitro group, a carboxyl group, an halogen atom and an hydroxymethyl group;
• and
• (B) 0.01 to 10 parts by weight of a pentaerythritol phosphorous ester having a spirocyclic structure.

A thermoplastic polymer composition which comprises 100 parts by weight of a thermoplastic polymer, 0.01 to 10 parts by weight of a benzyl compound (A) selected from the group consisting of the following general formulae (1), (2) and (3)

• wherein, R1 to R11 are each independently selected from the group consisting of a hydrogen atom, alkyl groups having 1 to 5 carbon atoms, cycloalkyl groups having 5 to 6 carbon atoms;
• Ar1, Ar3, Ar4, Ar5 and Ar6 are each independently a monovalent aromatic group having 6 to 20 carbon atoms which can have one or more substituents;
• Ar2 is a divalent aromatic group having 6 to 20 carbon atoms which can have one or more substituents;
• p is 0 or 1;
• X is a direct bond or is selected from the group consisting of an aliphatic residue leaving 1 to 20 carbon atoms, an alicyclic residue having 6 to 20 carbon atoms and an aromatic residue having 6 to 20 carbon atoms;
• n is one of the integers of 1 through 6;
• and wherein when n is 1, X is not a direct bond;
• and wherein the one or more substituents for Ar1, Ar2, Ar3, Ar4, Ar5 and Ar6 are selected from the group consisting of an alkyl group, a cycloalkyl group, an alkoxy group, an acyloxy group, an aralkyl group, an alkoxycarbonyl group, an aromatic group, an acyl group, a cyano group, a nitro group, a carboxyl group, an halogen atom and an hydroxymethyl group;
• and
• a pentaerythritol phosphorous ester (B) having a spirocyclic structure wherein the phosphorous ester (B) is contained at a ratio of 0.01 to 1 part by weight based on 100 parts by weight of said benzyl compound (A).