Patent GB-953112-A (GB)
Title: Stabilisation of polypropylene against discolouration
IPC: C08K5/372
Filed: 1960-09-01
Abstract: A propylene polymer stabilizer composition comprises an organic polysulphide and at least one compound selected from phenols, and organic trivalent phosphorous compounds.  The phenol may be p-octyl, p-dodecyl, p-octadecyl, 2,6-di-tert. butyl, 2,6-diisopropyl, methylene-bis-2,6-di-tert. butyl, or 4,41-thio-bis-phenol, or 4,41-thio-bis-(3-methyl-6-tert.-butyl phenol), 2,6-diisoctyl resorcinol, 4-octyl pyrogallol, 3,5-di-tert. butyl catechol, p-isooctyl m-cresol, or 2,6-di-tert. butyl-p-cresol.  The organic phosphorous compound may be triphenyl, diphenyl methyl, tritolyl, trixylyl, phenyl dicyclohexyl, phenyldiethyl, tribenzyl, or di-2-ethyl hexyl phenyl phosphine, or tri-phenyl-, tricresyl-, tri-(di-methyl-phenyl)-, tributyl-, trioctyl-, tridodecyl-, octyl diphenyl-, dioctyl phenyl-, tri(octyl-phenyl)-, tri-(nonyl-phenyl)-, tri-benzyl-, butyl dicresyl-, octyl di-(octylphenyl)-, tri(2-ethyl-hexyl)-, tri(2-cyclohexylphenyl)-, tri-alpha-naphthyl-, tri-(phenylphenyl)-, or tri(2-phenylethyl) phosphite. The organic polysulphide is preferably of the formula, R(S)n-R wherein n represents the number of sulphur atoms, in the range of 2 to 6, and R is an organic radical.  Specified polysulphides are n-dodecyl trisulphide, tert. dodecyl or tetramethyl thiuram disulphide, tert. octyl thiuram tetrasulphide, dimethyl thiuram hexasulphide, tetraethyl thiuram trisulphide, benzothiazyl disulphide, p-tert. butyl phenyl trisulphide, dioctyl dithiodiacetate, dibenzyl disulphide, dibenzyl tetrasulphide, and dibenzyl trisulphide. The polymer stabilized may contain other conventional stabilizers.  The polymer stabilized may be isotactic polypropylene, a copolymer of ethylene and propylene, or a mixture of polypropylene and polyethylene.ALSO:A stabilizer composition comprises an organic polysulphide, and at least one compound selected from phenols, and organic trivalent phosphorous compounds.  The phenol may be p-octyl, p-dodecyl, p-octadecyl, 2,6-di-tert. butyl, 2,6-di-isopropyl, methylene-bis-2,6-di-tert. butyl, or 4,41-thio-bis-phenol, or 4,41-thio-bis-(3-methyl-6-tert. butyl phenol), 2,6-diisooctyl resorcinol, 4-octyl pyrogallol, 3,5-di-tert. butyl catechol, p-isooctyl m-cresol, or 2,6-di-tert. butyl-p-cresol. The organic phosphorous compound may be triphenyl, diphenyl methyl, tritolyl, trixylyl, phenyl dicyclohexyl, phenyldiethyl, tribenzyl, or di-2-ethylhexyl phenyl phosphine, or tri-phenyl-, tri-cresyl-, tri-(dimethyl-phenyl)-, tributyl-, tri-octyl-, tridodecyl-, octyl diphenyl-, dioctyl phenyl-, tri-(octyl-phenyl)-, tri-(nonyl-phenyl)-, tri-benzyl-, butyl dicresyl-, octyl di-(octyl-phenol)-, tri(2-ethyl hexyl)-, tri(2-cyclohexyl-phenyl)-, tri-alpha-naphthyl-, tri(phenylphenyl)-, or tri(2-phenylethyl) phosphite.  The organic polysulphide is preferably of the formula, R(S)n-R where n is an integer from 2 to 6, and R is an organic radical.  Specified polysulphides are n-dodecyl trisulphide, tert.-dodecyl or tetramethyl thiuram disulphide, tert. octyl thiuram tetrasulphide, dimethyl thiuram hexasulphide, tetraethyl thiuram trisulphide, benzothiazyl disulphide, p-tert. butyl-phenyl trisulphide, dioctyl dithiodiacetate, dibenzyl disulphide, dibenzyl tetrasulphide, and dibenzyl trisulphide.  The compositions are used for stabilizing ethylene and/or propylene polymers.