Patent GB-970970-A (GB)
Title: Substituted hydroquinone monocarbamates and the stabilization therewith of organic material against oxidative deterioration
IPC: C09K15/24
Filed: 1963-09-16
Abstract: The invention comprises compounds of formula <FORM:0970970/C1/1> wherein R1 is alkyl, R2 is hydrogen or C1-8-alkyl, and A is C1-24-alkyl or C7-12 -alkylphenyl; alternatively, A is phenylene, C1-6-alkyl phenylene or C1-6 alkylene di(phenylene), and in these cases the free valency is joined to another hydroquinone monocarbonate residue.  Compounds of the above formula are prepared by reacting together the appropriate hydroquinone and isocyanate. Aldehydes (e.g. heptaldehyde) and aliphatic esters may be stabilized by the presence of the above compounds.  Specified esters are di(2-ethylhexyl) azelate, pimelate and adipate; di-(3, 5, 5-trimethylpentyl) and di-(3, 5, 5-trimethylhexyl) glutarates; dipropylene glycol di- and trimethylolpropane tri-pelargonates; dihexyl azelate, diisoamyl adipate, triamyl tricarballylate, pentaerythritol tetracaproate and 1,5-pentanediol-di-(2 -ethylhexanoate).ALSO:Polyolefins, especially polypropylene and polyethylene, but also e.g. polystyrene containing butadiene-styrene copolymers, are stabilized by the presence of compounds of formula <FORM:0970970/C3/1> wherein R1 is alkyl, R2 is hydrogen or C1- 8-alkyl, and A is C1- 24-alkyl or C-1- 12-alkylphenyl; alternatively, A is phenylene, C1- 6-alkyl phenylene or C1- 6-alkylene di(phenylene), and in these cases the free valency is joined to another hydroquinone monocarbamate residue. It is preferred to use an additional stabilizer of formula S[CH2(CH2)nCO2R]2 wherein n is 1 or 2 and is C8- 24-alkyl, especially dilauryl betathiodipropionate. Examples describe the stabilization of polypropylene.ALSO:Organic materials subject to deterioration are stabilized by the presence of compounds of formula <FORM:0970970/C4-C5/1> wherein R1 is alkyl, R2 is hydrogen or C1-8-alkyl, and A is C1-24-alkyl or C1-12-alkylphenyl; alternatively, A is phenylene, C1-6-alkyl phenylene or C1-6-alkylene di(phenylene), and in these cases the free valency is joined to another hydroquinone monocarbamate residue.  An additional stabilizer of formula S[CH2(CH2)n CO2R]2 wherein n is 1 or 2 and R is C8-24-alkyl, may also be present.  Specified materials are (a) synthetic lubricating oils, in particular aliphatic esters such as di-(2-ethylhexyl)azelate, pimelate and adipate, di-(3,5,5-trimethyl pentyl) and di-(3,5,5-trimethylhexyl) glutarates, dipropylene glycol di- and trimethylolpropane tri-pelargonates, dihexyl azelate, diisoamyl adipate, triamyl tricarballylate, pentaerythritol tetracaproate and 1,5-pentanediol-di-(2-ethylhexanoate); (b) hydrocarbons, including saturated and unsaturated gasolines, jet fuel, diesel, mineral, fuel and drying oils, waxes and resins; (c) linseed, merhaden, cod liver, castor oleic, rapeseed, coconut, palm, corn, sesame, peanut and cottonseed oils, fat, lard and beef tallow; (d) cycloolefins e.g. cyclohexose.ALSO:A stabilizer system for organic materials subject to oxidative deterioration comprises (a) a compound of formula <FORM:0970970/B1-B2/1> wherein R1 is alkyl, R2 is hydrogen or C1-8-alkyl, and A is C1-24-alkyl or C7-12-alkylphenyl, but alternatively, A may be phenylene, C1-6-alkyl phenylene or C1-6-alkylene di(phenylene), and in these cases the free valency is joined to another hydroquinone monocarbamate residue; (b) a compound of formula S[CH2(CH2)nCO2R]2 wherein n is 1 or 2 and R is C8-24-alkyl.ALSO:Butter is stabilized against oxidative deterioration by the presence of a compound of formula <FORM:0970970/A1-A3/1> wherein R1 is alkyl, R2 is hydrogen or C1-8-alkyl, and A is C1-24-alkyl or C7-12-alkyl-phenyl; alternatively, A is phenylene, C1-6-alkyl phenylene or C1-6-alkylene di (phenylene) and in these cases the free valency is joined to another hydroquinone monocarbamate residue.  An additional stabilizer of formula S[CH (CH2)nCO2R]2, wherein n is 1 or 2 and R is C8-24-alkyl, may also be present.