CS212974B1 - Yellow fluorescent dyes - Google Patents

Abstract

Yellow fluorescent dyes for dyeing synthetic materials in bulk of the general formula in which R denotes 1-naphthyl- or 1-naphthoyl-.

Description

The invention relates to novel yellow to yellow-green fluorescing methine-type bervatives. The structure of the new dyes is represented by the general formula I

wherein R is 1-naphthyl or 1-naphthoyl.

Known and world-produced methine dyes, which primarily serve as disperse dyes or pigments, contain predominantly only one methine group in their molecule. They are usually prepared by condensation of Ν, Ν-dialkylaminobenzaldehydes, optionally further substituted, with suitable compounds having at least one active hydrogen in their structure. Such compounds are, for example, phenylacetic acid, naphthylacetic acid derivatives, pyrazolones, acetic acid derivatives and the like. The dyes are generally yellow, golden yellow or orange and do not show any significant fluorescence. It has now been found that new meth color dyes of formula I can be prepared.

By applying the new wavelength dyes of the above structure to the mass of synthetic fibers, for example polyester, polyamide, polyacrylonitrile and polypropylene, or to the mass of polyacrylates or polystyrene, fluorescent materials dyed in yellow to yellow-green tint can be obtained. Fluorescence also causes increased brilliance and brightness of the dye and creates an impressive effect especially when applied at lower concentrations in organic glasses.

The synthesis of these dyes is carried out by condensing terephthalaldehyde with a compound R-GHG-ON, wherein R is 1-naphthyl or 1-naphthoyl, at 40 ^0-100 ° C, preferably 60-80 ° C. The condensation may be carried out in the presence of an organic solvent, preferably ethanol or methanol. Trace amounts of piperidine, alkali hydroxide or alcoholate may be added as a catalyst to significantly accelerate the condensation reaction. The reaction is complete in a few minutes. The precipitated product is isolated by filtration and, after drying and optional grinding, the product can be applied directly to the polymer mass prior to spinning or to the monomer mass prior to polymaration.

The examples below illustrate the preparation of the novel dyes of the invention.

Example 1

2 parts of sodium hydroxide were dissolved in 500 parts of ethanol, and 33.5 parts of 1-nephthylacetic acid nitrile and 13.4 parts of terephthalaldehyde were added successively. The mixture was then heated to reflux and refluxed for 1 hour. Upon completion of the reaction, the product of formula I / 3 precipitated. = 1-naphthyl / aspirate, washed with water until loss of alkalinity and dried. Yield 42.7 parts, mp> 260 ° C. Substance

212 974 paints synthetic materials in matter with a bright yellow color with strong yellow fluorescence

Example 2

To 400 parts of ethanol 39 parts of N - (- cyanoethyl) naphthalene and 13.4 parts of terephthalaldehyde were gradually added with stirring. The mixture was heated to boiling and refluxed for 2 hours after addition of 2 parts piperidine. After cooling, the precipitated product was filtered off, washed with 100 parts of water and dried. The yield of the product was 47.5 parts, the melting point of the orange needles of the product of formula I (R = 1-naphthoyl) was higher than 260 ° C. The product, like the previous ones, paints synthetic materials in the mass with a golden-yellow tint.

All parts given in the examples are by weight.

Claims (1)

Yellow fluorescent dyes for dyeing synthetic materials in the mass of the general formula NC CN in which R represents 1-naphthyl- or 1-naphthoyl-