The B. F. Goodrich Company

Dwight W Chasar

Robert W Layer

Chin C Hsu

Perry D Matheny

Branched and cyclic N,N-dialkyldithiocarbamyl accelerators for the sulfur vulcanization of rubber have been found to generally perform as well as the corresponding straight chain N,N-dialkyldithiocarbamyl accelerators, but surprisingly do not produce detectable amounts of environmentally undesirable N-nitrosamines. The branched N,N-alkyldithiocarbamyl accelerators are generally represented by the formula: ##STR1## where R is a branched alkyl group, R' is an alkyl group which may or may not be branched or a cyclic alkyl group or an alkaryl or aryl group, X is another thiocarbamyl group of the same general structure, a primary alkylamino group, an alkylthio group, a 2-benzothiazyl group, or a metal ion, and n is an integer of from 1 to 6. The cyclic dithiocarbamyl accelerators of the invention are generally represented by the formula ##STR2## where X is another thiocarbamyl group of the same general structure, a primary alkylamino group, an alkylthio group, a 2-benzothiazyl group, or a metal ion, and n is an integer of from 1 to 6.

Method of curing rubbers without forming nitrosamines

Cured rubber compositions having reduced nitrosamine content are made with small amounts by weight of an alkaline earth oxide or hydroxide which are utilized in association with secondary amine containing accelerators. The amount of nitrosamine in the cured rubber is often reduced to less than 20 parts per billion.

Alkaline earth oxides and hydroxides to reduce nitrosamine formation

A method for, and compositions, providing vulcanizable compounds of unsaturated polymers having an improved balance of scorch time and cure rates, ie., slow scorch times and fast cure rates, comprising adding to said vulcanizable polymers accelerating amounts of benzothiazolesulfenamides selected from the group consisting of N-oxydiethylene-2-benzothiazole sulfenamide, N-t-butyl-2-benzothiazole sulfenamide and N-cyclohexyl-2-benzothiazole sulfenamide, with N-oxydiethylenethiocarbamyl-N'-t-alkyl sulfenamides wherein the alkyl radicals contain 4 to 8 carbon atoms.

Vulcanization accelerators

2,4-bis(2,6-di-t-alkyl-4-substituted-phenoxy)-1,3,2,4-dioxadiphosphetanes are prepared from 2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes.

2,4-bis-(2,6-di-t-alkyl-4-substituted-phenoxy)-1

Tetrakis(2,6-di-t-butyl-4-substituted phenyl)4,4'-substitutedbisphenyl diphosphites that are prepared from a hindered phenol and a non-hindered bisphenol have been found to be excellent stabilizers for organic materials subject to degradation, and form even more effective combinations with hydroxyphenylalkyleneyl isocyanurates, substantially and synergistically enhancing the stabilizing efficiency of the isocyanurate.

Tetrakis(2,6-di-t-butyl-4-substituted phenyl)4,4'-bisphenyl diphosphites

Substituted 2-(2,6-di-t-butyl-4-alkylphenoxy)-4H-1,3,2-benzodioxaphosphorins that are readily prepared, for example from hindered phenols and ortho-methylolphenols, are effective heat and anti-oxidant stabilizers for organic materials subject to degradation by heat and oxygen, and provide particularly efficient stabilizer systems when combined with hydroxyphenylalkyleneyl isocyanurates.

Substituted 2-(2,6-di-t-butly-4-alkylphenoxy)

Amines are reacted with phosphorous trichloride to form N-dichlorophosphinoamines that are then reacted with a bisphenol in about equimolar amounts to provide polyphosphoramidite oligomers. The polyphosphoramidite oligomers are effective as stabilizers for polymers such as polyolefins, and form even more efficient stabilizer combinations with hydroxyphenylalkyleneyl isocyanurates.

Polyphosphoramidite oligomers and stabilizer compositions thereof

Tris (3,6-di-t-butyl-2-naphthyl) phosphite is a heat and hydrolysis resistant stabilizer for organic materials subject to heat and ultra-violet degradation, and in combination with hydroxy-phenylalkyleneyl isocyanurates, provides a useful synergistic combination for use in polymers, particularly hydrocarbon polymers including the poly(olefins).

Tris (3,6-di-t-butyl-2-naphthyl) phosphite and compositions thereof

An improved process for preparing 2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes is realized when the appropriate substituted-phenylphosphorodichloridite is reacted with water in the presence of a trialkyl amine wherein the alkyl groups contain 4 to 8 carbon atoms in acetone as the sole solvent, to provide the desired 2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes in increased yields and of a higher purity.

Method for making 1,3,5,2,4,6-trioxatriphosphorinanes

Novel stabilizers for organic materials subject to degradation, 2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes are prepared by the reaction of substituted-phenylphosphorodichloridites, water and amines. The 2,4,6-tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes, form effective stabilizer combinations with hindered and partly hindered phenols such as hydroxyphenylalkyleneyl isocyanurates, particularly when used in polymers, polyolefins, for example.

2,4,6-Tris(substituted phenoxy)-1,3,5,2,4,6-trioxatriphosphorinanes as

2-naphthyl phosphoramidites are readily and inexpensively prepared by the reaction of N-dichlorophosphinoamines with a 2-naphthol in an alkylamine. The 2-naphthyl phosphoramidites are stabilizers for polymers such as the polyolefins and enhance the stabilizing activity of hydroxyphenylalkyleneyl isocyanurates.

2-Naphthyl phosphoramidites and compositions thereof

3,6-di-t-butyl-2-naphthyl catechol phosphite is readily prepared by the reaction of catechol phosphorodichloridite and 3,6-di-t-butylnathphol in the presence of a trialkyl amine in a solvent. The 3,6-di-t-butyl-2-naphthyl catechol phosphite is an excellent stabilizer for polymers, including polypropylene, and forms synergistic combinations with hydroxyphenylalkyleneyl isocyanurates that provide excellent resistance to polymer breakdown during processing.

3,6-Di-t-butyl-2-naphthyl catechol phosphite and compositions thereof

2-[Alkyl substituted-phenoxy]-2,3-dihydro-1,2-benzoxaphosphole 2-oxide, cyclic phosphonates prepared, for example from hindered phenols and ortho-methylolphenols, are effective heat stabilizers and antioxidants for organic materials subject to degradation by heat, oxygen and the like, and result in effective stabilizer systems when combined with hydroxyphenylalkylenyl isocyanurates.

5-Membered cyclic phosphonates and compositions thereof

[1.1.1.1.]metacyclophane is a cyclic compound consisting of two alkane bisphenol molecules coupled through their available ortho positions by a methylene moiety. The cyclic compound is initially formed as a dihydrate by reaction of a 2,2'-di-substituted alkane bisphenol such as a 2,2'-di-t.butylated alkane bisphenol with paraformaldehyde at about 170.degree. C. in an aromatic solvent. The dihydrate may be dehydrated under select conditions. The cyclic compound is an excellent antioxidant in mineral filled natural rubber, and in polyolefins, particularly in polypropylene.

Metacyclophane, synthesis thereof, and compositions stabilized thereby

2,6-Di-t-butyl-4-substituted phenyl bis(3,6-di-t-butyl-2-naphthyl)phosphites, readily prepared by reacting together a phosphorodichloridite of a 4-substituted-2,6-di-t-butylphenol and a sodium salt of 3,6-di-t-butyl-2-naphthol, to form antioxidant and ultraviolet stabilizers that form particularly effective combinations with hydroxyphenylalkyleneyl isocyanurates to provide enhanced oven aging properties to organic materials subject to attack by heat and oxygen.

Growing community of inventors

Northfield, OH, United States of America

Dwight W Chasar