GB232265A - Improvements in the production of perylene dyes - Google Patents

Abstract

By adding oxidizing agents during the condensation of perylene or its oxy or halogen derivatives with benzoic acid or its halides in the presence of aluminium chloride, the nature of the product is altered or the yield is increased; the same effect is also obtained during the heat treatment of the benzoyl products with aluminium chloride. The oxidizing agents mentioned are manganese peroxide, ferric oxide, ferric chloride, copper oxide and potassium nitrate, employed in quantities of up to 100 per cent by weight of the perylene compound treated. According to the examples (1) dibenzoylperylene is condensed as described in Specification 212,252 by means of aluminium chloride, but in the presence of pyrolusite and gives an increased yield of the product; (2) perylene and benzoylchloride are condensed in the presence of aluminium chloride and pyrolusite, resulting in an increased output; (3) by adding pyrolusite during the condensation of dibenzoyldioxyperylene (Specification 213,889) with aluminium chloride, a product is obtained which is different from that produced in the absence of the pyrolusite in that it dyes cotton green from a green vat; (4) the condensation product of dibromoperylene of m.p. 222-224 DEG C. (Specification 232,266) with benzoyl chloride by means of aluminium chloride dyes cotton bluish violet from a blue vat; when pyrolusite is added during the condensation in quantity equal to that of the perylene compound, the product dyes cotton violet blue from a blue vat; the addition of five times the quantity of pyrolusite gives a dyo which colours cotton red from a brownish red vat; (5) chloroperylene of m.p. 280 DEG C. (Specification 232,261) condensed with benzoyl chloride by means of aluminium chloride, produces a compound which dyes cotton violet from a blue vat; if pyrolusite be added, dyes are obtained which dye cotton lilac, red, violet or flesh colour, according to the amount of the addition or the period of condensation; (6) the condensation of tetrachloroperylene of m.p. 242 DEG C. (Specification 232,266) with benzoyl chloride in the presence of aluminium chloride yields a dye which gives a blue vat and colours cotton blue; the addition of manganese peroxide results in a product which dyes cotton rose from a violet vat. When freshly-precipitated manganese peroxide is used, the amount required is only one-tenth of that when pyrolusite is employed. The Specification as open to inspection under Sect. 91 (3) (a) describes also the use of nickel sulphate as a suitable oxidizing agent and includes the following examples:-(1) ferric chloride is added during the condensation of perylene and benzoic acid by means of aluminium chloride and favourably affects the yield; (2) the addition of nickel sulphate during the condensation of tetrachloroperylene of m.p. 242 DEG C. with benzoyl chloride in the presence of aluminium chloride yields a dye which colours cotton violet. This subject-matter does not appear in the Specification as accepted.