GB1128984A - Diacyl peroxide compositions - Google Patents

Abstract

1,128,984. Stable diacyl peroxide solutions. WALLACE & TIERNAN Inc. 27 May, 1966 [1 June, 1965], No. 23980/66. Heading C2C. Diacyl peroxides compositions which are safe, as hereinafter defined, comprise diacyl peroxides of the formula where R is a C 1-5 alkyl group, and such an amount of such a solvent having a vapour pressure substantially the same as that of the peroxide and selected from aliphatic hydrocarbons, aliphatic ketones, aliphatic esters, aliphatic ethers, aliphatic ketones and mixtures thereof, provided that the solvent is not an aliphatic hydrocarbon when the peroxide is diisovalenyl peroxide. The compositions are safe if they comply with the following: (1) they require a venting aperture of 10 mm. or less when subjected to a test in which a 5 g. sample of the composition is inserted in a cylindrical brass vessel of volume 235 c.c. having a removable apertured disc in the side wall and being closed at the top with a crowned shape, aluminium rupture disc prestressed to 90% of its burst strength at 98-100 p.s.i.g.; there are 74 apertured discs in which the diameter of the bore varies expotentially from 1-24 mm.; the sample in the cylinder is rapidly heated and the rupture disc burst or remains intact according to the size of the bore of the aperture disc; (2) the compositions exhibit no sensitivity to shock when subjected to the known impact tests; (3) the compositions exhibit mild to rapid decomposition, but not explosive decomposition, when subjected to a heat test comprising heating a 1 g. sample in a test tube at a rate of 4‹ C. per minute; and (4) the compositions exhibit no changes in peroxide assay, or active oxygen concentration, that result in impact sensitive products. The compositions may be prepared by (1) mixing hydrogen peroxide and an anhydride of the appropriate acid in the presence of the solvent and subsequently neutralizing the reaction mixture or (2) mixing the solvent and an aqueous alkaline solution, adding hydrogen peroxide to the resulting mixture and finally adding the appropriate acid halide; in both processes increase in temperature is prevented by cooling. Examples relate to compositions containing dipropionyl peroxide, diacetyl peroxide, diisobutyryl peroxide and di-2-methylpentanoyl peroxide, the solvents being selected from light naphtha, mineral spirits, hexyl acetate, diisobutyl ketone, ethylene glycol monobutyl ether, heptane, ethylbutyl ketone, methyl isoamyl ketone, methyl amyl acetate, ethylene glycol monoethyl ether acetate, dimethyl phthalate, ethylene glycol monobutyl ether acetate, diisobutyl ketone, ethylene glycol mono butyl ether, diacetone alcohol and 2- ethylhexyl acetate.