GB777811A - Improvement in the stabilization of organic materials - Google Patents

Abstract

Cellulose esters, polyesters and synthetic resins such as polyethylene are stabilized by the addition of an antioxidant of the general formula <FORM:0777811/IV(a)/1> where R is a hydrogen atom, an alkyl radical of 1-20 carbon atoms, a cycloalkyl radical of 6-10 carbon atoms, an alkenyl radical of 2-10 carbon atoms, an aryl radical of 6-10 carbon atoms, an aralkyl radical of 7-20 carbon atoms or a furyl radical. Many examples of the 2 : 4 : 5-trihydroxyphenones of the above formula are given, such as those in which R is propyl-, octyl-, cyclohexyl-, propenyl-, phenyl-, xylyl-, o -phenyl-n-decyl-, and furyl-. The antioxidant may be incorporated in the ester or resin in amounts from 0.001 to 1.0 per cent by weight and may be used in conjunction with other antioxidants, such as tert.-butyl-p-hydroxy-anisole and propyl gallate, and with synergists. Cellulose ester compositions containing cellulose acetate butyrate, dibutyl sebacate and 1 per cent of either 2 : 4 : 5-trihydroxyacetophenone or 2 : 4 : 5-trihydroxybenzophenone are described. The polyester compositions described comprise polyesters derived from 4 : 41-sulphonyl-bis-(benzoic acid), succinic acid and 1 : 5-pentanediol in the molar ratio of 5 : 1 : 6 and containing 1 per cent by weight of 2 : 4 : 5-trihydroxystearophenone, and polyesters derived from azelaic acid, 4 : 41-sulphonyl-bis-(benzoic acid) and 1 : 4-butanediol in the molar ratio 3 : 2 : 5 and containing 1 per cent by weight of either 2 : 4 : 5-trihydroxybutyrophenone or 2 : 4 : 5 - trihydroxystearophenone. The stabilized polyethylene compositions described are prepared by milling the antioxidant with polyethylene to obtain final compositions containing respectively 0.01, 0.05 and 0.10 per cent by weight of the antioxidant. The antioxidants used are the 2 : 4 : 5-trihydroxy - butyro -, - caprylo-, -stearo-, and -benzo-phenones. Incorporation of these compounds in polyethylene also affects the dielectric properties of the material, the dissipation factor being reduced. Specification 777,812 [Group IV (b)], is referred to.ALSO:Carotenoid vitamins are stabilized by the addition of antioxidants of the general formula <FORM:0777811/IV(b)/1> where R represents a hydrogen atom, an alkyl radical of 1-20 carbon atoms, a cycloalkyl radical of 6-10 carbon atoms, an alkenyl radical of 2-10 carbon atoms, an aryl radical of 6-10 carbon atoms, an aralkyl radical of 7-20 carbon atoms or a furyl radical. Many examples of compounds of the above formula are given. Mixtures of the above antioxidants with other antioxidants and/or synergists may be used. 2 : 4 : 5-Trihydroxy-acetophenone is prepared by heating 1 : 2 : 4-trihydroxybenzene with acetic anhydride and a solution of zinc chloride in acetic acid. 2 : 4 : 5-Trihydroxybenzophenone is prepared by reacting 1 : 2 : 4-trihydroxybenzene with benzonitrile in the presence of zinc chloride and hydrogen chloride, or by heating 1 : 2 : 4-trihydroxybenzene in nitrobenzene with benzoyl chloride in the presence of aluminium chloride, or by heating 1 : 2 : 4-trihydroxybenzene-monobenzoate with aluminium chloride. 1 : 2 : 4 - Trihydroxybenzene-monobenzoate is prepared by warming 1 : 2 : 4-trihydroxybenzene in nitrobenzene with benzoyl chloride and aluminium chloride. Specification 777,812 is referred to.ALSO:Fats, oils and waxes, for example, fuel oils, transformer oil, essential oils such as citrus oil, tallow, mineral waxes such as paraffin wax, vegetable waxes, vegetable oils such as cottonseed oil, peanut oil and corn oil, and petroleum products such as lubricating compositions, greases and paraffin, are stabilized by the addition of antioxidants of the general formula:- <FORM:0777811/III/1> where R is a hydrogen atom, an alkyl radical of 1-20 carbon atoms, a cycloalkyl radical of 6-10 carbon atoms, an alkenyl radical of 2-10 carbon atoms, an aryl radical of 6-10 carbon atoms, an aralkyl radical of 7-20 carbon atoms or a furyl radical. Many examples of the 2:4:5-trihydroxyphenones of the above formula are given, such as those in which R is propyl-, octyl-, cyclohexyl-, propenyl-, phenyl-, xylyl-, o -phenyl-n-decyl-, and furyl-. The antioxidant may be present in amounts of from 0.001 to 1.0 per cent by weight of the fat, oil or wax and may be incorporated into such materials as cottonseed oil, peanut oil or paraffin by simple mixing or by dissolving the antioxident in a solvent such as glycerine, propylene glycol or hexane before admixture. The compounds of the above formula may be used together with known antioxidants, such as tert.-butyl-p-hydroxyanisole and propylgallate, and with synergists. Fats and oils stabilized with 0.001 to 1.0 per cent by weight of a compound of the above formula and with 0.0005 to 0.1 per cent by weight of a synergist, such as citric acid, tartaric acid, phosphoric acid, ascorbic acid or propyl gallate, are mentioned. Paraffin wax compositions containing 0.01 per cent of a compound of the above formula where R is methyl-, propyl-, isopropyl-, heptyl-, amyl-, and undecyl-, respectively, are described. Stabilized peanut oils and stabilized cottonseed oils are described which contain 0.01-0.02 per cent by weight of compounds of the above formula where R is hydrogen, methyl, phenyl, heptyl, isopropyl, heptadecyl and propenyl. Stabilized corn oils containing 0.01-0.02 per cent by weight of the compounds where R is hydrogen, methyl and phenyl are also described. Specification 777,812 (Group IV(b)) is referred to.ALSO:Oils and fats such as lard, tallow and suet, cottonseed, corn and peanut oils and essential oils such as citrus oil are stabilized by the addition of antioxidants of the general formula:- <FORM:0777811/VI/1> wherein R represents a hydrogen atom, an alkyl radical of from 1 to 20 carbon atoms, a cycloalkyl radical of from 6 to 10 carbon atoms, an alkenyl radical of from 2 to 10 carbon atoms, an aryl radical of from 6 to 10 carbon atoms, an aralkyl radical of from 7 to 20 carbon atoms or a furyl radical. Many examples of the 2:4:5 - trihydroxyphenones of the above formula are given, including those in which R is propyl-, octyl-, cyclohexyl, propenyl-, phenyl-, xylyl-, o - phenyl - n - decyl-, and furyl-. The antioxidant may be incorporated into the oil or fat by simple mixing to form a solution or dispersion of may be dissolved in solvent such as glycerol, propylene glycol or hexane before admixture with the fat or oil. Synergists such as citric acid, tartaric acid, phosphoric acid, ascorbic or propyl gallate may be used, fats and oils containing 0.001 per cent to 1.0 per cent by weight of the antioxidant and 0.0005 per cent to 0.1 per cent by weight of such synergist being mentioned. Mixtures of the antioxidants with other antioxidants such as tert. - butyl - p - hydroxyanisole and propyl gallate may be used. Lards containing 0.02 per cent by weight of antioxidants of the above general formula where R is methyl-, propyl, isopropyl-, a -ethyl-propyl-, heptyl-, a - ethyl-pentyl-, nonyl-, undecyl-, heptadecyl-, phenyl, benzyl-, cyclohexyl-, propenyl-, and furylare compared with lards containing butylated hydroxy anisole, propyl gallate, hydroquinone, 1:2:4 - trihydroxybenzene, and 2:5 - dihydroxy-aceto-, butyro-, and -benzo-phenones. Specification 777,812 [Group IV(b)] is referred to.