Dichlorotriazine dyes

Amination A/-Methylolacrylamide in presence of Lewis acid catalyst. Further modifications possible by addition to double bond (Scheme 10.61) Amines with durable press resins Improved dyeability with dichlorotriazine dyes at pH 5 without salt, giving 99% fixation Some improvements in dyeability, especially with direct dyes, but light fastness can be a problem... 

Thiourea derivative of Hercosett (isothiouronium salt) Scheme 10.63 Build-up good for dichlorotriazine dyes. Dyes of other types gave good results up to about 2% applied depths... 

Exploitation of the dichlorotriazine dyes soon led to parallel development of the much less reactive aminochloro-s-triazine derivatives, which ultimately became the most successful of all reactive dye systems. Aminochlorotriazine dyes (such as 7.2) are readily prepared by a substitution reaction (Scheme 7.2) at 30-40 °C between an arylamine and the dichlorotriazine precursor (7.1 in this instance). Dyes of the aminochlorotriazine type [6] were launched simultaneously as Cibacron (Ciba) and Procion H (ICI) brands shortly after the dichlorotriazine dyes had been introduced. More stable pad liquors could be formulated... 

Selecting a sulphonated dye molecule containing an amino group as the nucleophile leads directly to a dichlorotriazine dye. In certain cases a suitable intermediate may be condensed with cyanuric chloride and then the chromogenic grouping is synthesised from this reaction product. Both of these routes are illustrated in a simple way for Cl Reactive Red 1 (7.1) in Scheme 7.7. In these dyes the electronic effects responsible for the lability of the chloro substituents are muted by feedback of electrons from the electron-donating imino bridging... 

Several different approaches have been employed in order to build the bifunctionality concept into known dye chromogens. In the case of bis(dichlorotriazine) dyes, which were not exploited commercially, only the arrangement 7.55 is feasible. The difficulty of introducing sufficient extra sulphonic acid groups into the chromogen to compensate for the presence of these two reactive systems and provide adequate solubility and mobility at the low dyeing temperature necessary for such highly reactive molecules proved insuperable. 

In the case of quaternary derivatives made from the non-planar aliphatic amines 7.64, 7.65 and 7.66, steric strains further destabilise the C-N+ bond so that reaction with cellulose occurs under alkaline conditions at 30 °C, whereas temperatures of about 40-50 °C are required for the pyridinium derivatives 7.67. The quaternisation approach appeared to offer the opportunity to prepare dyes yielding reactivity levels intermediate between those of aminochloro- and dichlorotriazine dyes without loss of the desirable stability of the dye-fibre bond to acidic conditions that is characteristic of aminohalotriazine dyes. Unfortunately, this ideal was not attainable because of the objectionable odours of the tertiary amines liberated by the fixation reaction and the sensitivity of the reactivity behaviour of the quaternised derivatives to the nature of the chromogen attached to the triazine ring, making it difficult to select compatible combinations of dyes. 

Silk can be readily dyed with conventional high-reactivity dyes of the dichlorotriazine, dichloroquinoxaline or difluoropyrimidine classes. Exhaust dyeing at 60-70 °C and pH 5-6 gives satisfactory results, especially if a mildly alkaline aftertreatment is given to enhance fixation. Dichlorotriazine dyes can also be applied by pad-batch dyeing with bicarbonate and a batching time of 4-6 hours. The relatively low reactivity of aminochlorotriazine dyes, however, results in moderate to poor build-up on silk. Tertiary amine catalysts such as DABCO (7.66) can be used to accelerate the dye-fibre reaction and increase the fixation substantially [116], but it is difficult to achieve satisfactory compatibility in mixture dyeings by this method (section 7.4.2). 

The introduction of Calcobond dyes a few years later by American Cyanamid exploited a similar principle but incorporated the N-methylol groups into the dye molecule itself [132]. The labile chloro substituents in dichlorotriazine dyes were converted to amino groups by substitution with ammonia and the resulting melamine residue made cellulose-reactive again by reaction with formaldehyde (Scheme 7.59). A typical member of this range was Cl Reactive Red 92 (7.120). A characteristic problem of the Procion Resin process and of the... 

The purity and stability of three dichlorotriazine dyes applied in nonlinear optical materials was checked by RP-HPLC. The chemical structures of the dyes are shown in Fig. 3.131. Analyses were realized in an ODS column (250 X 4.6 mm i.d. particle size 5 jtim) using gradient elution. Aqueous ammonium acetate (50 mM) and methanol were solvents A and B, respectively. The detection wavelength depended on the absorption maxima of the dye. Chromatograms illustrating the decomposition of dyes under alkaline conditions are depicted in Fig. 3.132. It was established that the application of RP-F1PLC for the study of the purity and stability of dyes may facilitate their use in nonlinear optical materials. [179],... 

Ja. Kalontratov, A.E. Kharkharov, Effect of light weather on physico-mechanical properties of kapron fibre dyed by dichlorotriazine dyes. Report of the Academy of sciences ofTadzhic SSR (1967), 10 No 5, 50-52 (in Russian). 

Ja. Kalontarov, Investigation in the field of polyamide kapron fibre dyeing by active dichlorotriazine dyes. Transactions of all-Union conference on the problems of synthesis and use of organic dyes. Ivanova. Publishing house of Chemical-technological institute (1962), 198-206 (in Russian). 

The aim of this work is firstly to test the applicability of a dichlorotriazine dye for polyester, silk, wool, cotton and aminated cotton in moist scCO and secondly to determine the influence of pressure and temperature on the dyeing... 

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