GB720511A - Biocidal compositions and processes for preparing same - Google Patents

Abstract

Concentrated compositions containing 4 : 6-dinitro cresol and hydrocarbon oil suitable for dilution with water to yield spray liquids comprise 10-60 per cent., preferably 25-45 per cent., of D.N.O.C. and/or salts thereof, 10-40 per cent., preferably 15-25 per cent. of a hydrocarbon oil boiling within the range of 150 DEG -450 DEG C., preferably 250 DEG -400 DEG C., 0.25-10 per cent., preferably 3-6 per cent. of an emulsifying agent and from 25-60 per cent., preferably 35-55 per cent., of water, the D.N.O.C. and/or salts thereof being present in suspended condition, the size of the particles being between 5 and 20m , preferably between 10 and 15m . Spindle oil and kerosene may be used as the hydrocarbon oil. The emulsifying agent is preferably of the non-ionic type, for example the polyethylene glycol ether of ethyl phenol known as Triton X100 (Triton is a Registered Trade Mark). A small portion, for example 0.5-1 per cent. of an ionic emulsifier may be present. Ionic emulsifiers specified are oleates sodium naphtha sulphonate. The D.N.O.C. may be present in the form of the ammonium salt. Other pesticidal substances, for example, 1,1, 1-trichloro-2, 2-bis (p-chlorophenyl) ethane, may also be present in emulsified, suspended or dissolved condition in one or both of the liquid phases, partially replacing the D.N.O.C. or hydrocarbon oil depending on whether the substance is contained in the aqueous or oil phase. The proportion of oil replaced should not exceed 50 per cent. and that of D.N.O.C., 75 per cent. and preferably 50 per cent. Other substances specified are potassium hydroxide, sodium sulphate, casein, oleic acid and ammonium oleate. A minor proportion of free ammonia may be present to improve the pourability of the composition. Other ingredients such as peptizing agents, for example dodecyl amine, corrosion inhibitors, and solid carrier materials, may be present provided the essential ingredients remain in the mutual proportions specified. The D.N.O.C. and/or salts thereof are prepared in the required degree of fineness by recrystallisation and/or by grinding in the presence of liquid, for example in a paint roller mill. Specifications 633,885 and 666,109 and 679,399 are referred to.