STABILIZATION AND MODIFICATION OF POLYCAPROAMIDE - Photochemical Reactions in Heterochain Polymers - page 14

found their application; sometimes carbon products of the pyrolysis of organic compound of
dymethylizozincomyronaphtha type [90] are used instead of black.
For the last time a great number of new dyes, such as azo dyes, derivatives of
antrapyridon and antrapyrimidon [44], derivatives of perylene [91], water-soluble ethers of
antrachinon [92] condensation products of symmetric and asymmetric indigoide colours with
aryl-cyclohalogenides [93], derivatives of phthalocyanine [94] and others have been
synthesized.
Most of the azo dyes destruct because of the low resistance of azo-groups to reducing
medium of polymer melt. Azo-dyes metallo-complexes with the composition (1:2), not
having free sulfo - and carboxyl groups in the molecule composition are the exception.
Formation of the complex, involving N-atom of azo-group into coordination bond,
increases stability of the latter [95-98]. Dyes of different colours may be selected from
metallocomplexes, however derivatives of pyrasolon possess the highest stability and dye PA
into colours from yellow to red, for example, yellow dye:
Interesting colours for mass dyeing of synthetic linear PA are obtained by using 1:2
chromium complexes of 0,01 - dioximonoazo-dyes of benzolazo - 1-phenyl - 3-
methylpyrasolon and/or benzolazonaphthalene series [98] and chromo - ferrous complex
[99].
A great number of patents deal with the derivative of antrachinone [100]. Thermostable
and lightfast dye of green colour has been patented [101]. The firm CIBA suggests brown
pigments thermostable in PA melt, in the molecule of which two substituted antrachinone
residues are condensed by aromatic, more often polycyclic radical of naphthalene type,
antrachinone and so on [102, 103].
However, it should be noted that despite the variety of synthesized dyes, both
metallocomplex and antrachinone, their use for direct introduction into polymer is limited
because of the impurities of inorganic salts.
Dyes of similar type are developed in UIS states [104]. They are produced in the form of
salts with amines suitable both for mass dyeing, by introducing into finished polymer, and for