Patent GB-576793-A (GB)
Title: Improvements in the dyeing of synthetic polymers
IPC: D06P1/649
Filed: 1944-04-06
Abstract: Polymerized esters of acrylic acid or its substitution products with saturated alcohols, e.g. in the form of granules, mouldings, cast sheets or other shaped articles, are surface-dyed by immersion in an aqueous dyebath containing a dyestuff suitable for dyeing cellulose esters in aqueous media, with an addition of from 0.1 to 5 per cent of one or more substances which are amines, amides, phenols, aromatic carboxylic acids, cyclic alcohols or cyclic ketones.  The material may be dyed and then softened by heat and shaped while hot. Specified dyestuffs are those known under the Registered Trade Marks "Dispersol," "Duranol" and "Solacet" and under the trade name "Safranine" and specified added substances are aniline, urea, acetamide, phenol, b -naphthol, benzoic acid, cyclohexanol and cyclohexanone. Specified polymerized esters dyed are the polymers of methyl acrylate, methyl, ethyl and isobutyl methacrylates, and methyl a -chloroacrylate and their interpolymers and heteropolymers, and they may contain fillers, e.g. lithopone, pigments, e.g. titanox, or plasticisers, e.g. dibutyl phthalate.  In examples: (1) granules of polymerized methyl methacrylate, prepared as described in Specification 427,494, are dyed by stirring them for 1 hour in an aqueous bath at 60 DEG  C. containing 1 per cent of phenol and 1 per cent of Duranol brilliant blue B300 or 2G300, Duranol red 2B300, Duranol brilliant orange G300, Safranine T125, Solacet fast crimson B, Solacet fast yellow G or Dispersol fast orange G150; the dyed granules may be injection-moulded or may be applied to textile materials by a methyl acrylate cement to provide a scintillating colour effect; (2) cast sheets of polymerized methyl methacrylate containing 5 per cent of dibutyl phthalate are dyed by treatment for 3 minutes to 15 hours in an aqueous bath, at temperatures ranging from 95 DEG  C. for the 3 minutes to 20 DEG  C. for the 15 hours, containing 1 per cent of b -naphthol, 3 per cent of sodium carbonate and 1 per cent of Duranol brillant blue B300; (3) granules of an interpolymer from methyl methacrylate (90 parts) and styrene (10 parts), prepared as described in Specification 427,494 are malaxated on hot rolls and the resulting sheet disintegrated and injection-moulded to form combs which are dyed by immersion for 1/2 hour in a stirred aqueous bath at 50 DEG  C. containing 2 per cent of urea, 0.2 per cent of "Lissapol C" (Registered Trade Mark) and 1 per cent of Duranol brilliant orange G300; (4) cast sheets of unplasticised polymerized isobutyl methacrylate are dyed by immersion in an aqueous bath at 90 DEG  C. containing 1 per cent of benzoic acid, 0.1 per cent of Lissapol C and 1 per cent of Duranol brilliant blue 300; (5) cast sheets of polymerized methyl methacrylate, plasticised with dibutyl phthalate, are dyed a deep green, for use as signal glasses, by immersion in an aqueous bath at 90 DEG  C. containing 2 per cent of phenol, 0.5 per cent of ammonium chloride, 0.1 per cent of Lissapol C, 1.5 per cent of Solacet fast red G and 0.5 per cent of Duranol brilliant blue B300; (6) similar sheets are dyed red for similar use by immersion in an aqueous bath at 90 DEG C. containing 2 per cent of phenol and 1 per cent each of Solacet fast red 3R and Duranol red G300; (7) sheets of polymerized methyl methacrylate are dyed a medium red, for similar use, by immersion in an aqueous solution at 50 DEG  C. containing 1 per cent of quinoline and 1 per cent of Solacet fast red 3R; (8) a sheet of polymerized methyl a -chloroacrylate is stencilled with a solution of polystyrene in carbon tetrachloride and immersed in an aqueous solution at 90 DEG C. containing 1 per cent of phenol, 0.5 per cent of ammonium chloride, 0.9 per cent of Duranol blue G, 0.3 per cent of Duranol brilliant yellow and 0.09 per cent of Dispersol fast scarlet B150 to obtain a brown pattern on an undyed ground; (9) a sheet of "Perspex" (Registered Trade Mark) is dyed yellow by immersion in an aqueous solution at 90 DEG  C. containing 1 per cent of phenol, 0.5 per cent of ammonium chloride and 1.0 per cent of Duranol brilliant yellow G300, dabbed locally with a 3 per cent solution of polystyrene and, after allowing the solvent to evaporate, immersed in an aqueous solution at 90 DEG  C. containing 1 per cent of phenol, 0.5 per cent of ammonium chloride and 1.0 per cent of Duranol red 2B300, and the product is heated to 140 DEG  C. and shaped to provide a mottled lampshade; (10) a mixture of polymeric and monomeric methyl methacrylates, containing 0.34 per cent of Titanox HR, 0.005 per cent of Pure middle chrome and 0.0025 per cent of Chrome orange, in the form of a dough, is moulded to the shape of a tooth and heated for 1/2 hour in boiling water and the neck of this artificial tooth is coloured to resemble a natural tooth by dipping it into an aqueous solution at 90 DEG  C. containing 1 per cent of phenol, 0.1 per cent of Lissapol, 1 per cent of Dispersol diazo black B150 and 0.5 per cent of Dispersol fast scarlet B150, removing it, allowing the solution to drain off towards the neck end and repeating the dipping and draining.  Reference has been directed by the Comptroller to Specification 545,117.ALSO:A mixture of polymeric and monomeric methyl methacrylates, containing 0.34 per cent. of Titanor HR, 0.005 per cent. of Pure middle chrome and 0.0025 per cent. of Chrome orange, in the form of a dough, is moulded to the shape of a tooth and heated for 1/2 hour in boiling water, and the neck of this artificial tooth is coloured to resemble a natural tooth by dipping it into an aqueous solution at 90 DEG C. containing 1 per cent. of phenol, 0.1 per cent. of Lissapol.  1 per cent. of Dispersol diazo black B 150 and 0.5 per cent. of Dispersol fast scarlet B 150 (the words "Lissapol" and Dispersol" are Registered Trade Marks), removing it, allowing the solution to drain off towards the neck end and repeating the dipping and draining.  Reference has been directed by the Comptroller to Specification 545,117, [Group IV].