Patent GB-824659-A (GB)
Title: Process for the optical brightening of fibres of polyacrylonitrile
IPC: D06M13/35
Filed: 1956-02-14
Abstract: A process for optical brightening of fibres, yarns or fabrics composed of or containing acrylonitrile polymers or copolymers thereof comprises treating the fibres with a non-quaternary compound having no dyestuff character, which is colourless or only slightly coloured and free from neutralized or free sulphonic or carboxylic acid groups and which, in solution or on a substratum, fluoresces green-blue to violet in daylight or ultra-violet light, the compound having the formula <FORM:0824659/III/1> wherein A is a benzene radical which may be alkyl, alkoxy, amino, alkylamino, acylamino or halogen substituted, R is a radical with at least three conjugated double bonds which are also in conjugation with the -N=C< bond of the hetero ring, which radical may contain hetero atoms and may be constituted, at least in part, by a benzene ring or other cyclic structure, and B is a sulphur atom, an oxygen atom or the group >N-R1 in which R1 is a hydrogen atom or an alkyl, hydroxy alkyl or aralkyl radical. Examples of the radical R include -CH=CH-CH=CH-CH=CH-CH=CH2 <FORM:0824659/III/2> Among the compounds specified are those which have the following formulae <FORM:0824659/III/3> where R2 is a thiophene ring attached in 2,5 position <FORM:0824659/III/4> The compounds may be admixed with soaps, sulphonated benzimidazoles substituted at the 2-carbon atom by higher alkyl radicals, salts of monocarboxylic acid esters of 4-sulphophthalic acid with higher fatty alcohols, salts of fatty alcohol sulphonates, alkylaryl sulphonic acids or condensates of higher fatty acids with aliphatic hydroxy- or amino-sulphonic acids and various non-ionic compounds.  Such washing agents may also contain alkali metal carbonates, phosphates, pyrophosphates, polyphosphates, metaphosphates, silicates, perborates or percarbonates.  In Example (5), acrylonitrile fibres are washed in a liquid containing a  : b -di-[N-methyl - benzimidazolyl - (2)] - ethylene and soap or a detergent comprising soap, anhydrous sodium carbonate, sodium pyrophosphate, sodium perborate and magnesium silicate.ALSO:a :b  - Di - [5 - methyl - benzoxazoyl - (2)] - ethylene is prepared (Example 8) by adding fumaric acid dichloride dropwise to a chlorbenzene solution of 1-amino-2-hydroxy-5-methyl benzene at 125-130 DEG  C. and reacting the resulting fumaric acid dianilide with ethylene glycol in the presence of zinc chloride at 155-160 DEG  C. and then acidifying the reacted mixture.  The compound is a brightening agent for polyacrylonitrile fibres (see Group IV (c)).  Specifications 611,510 and 653,681 are referred to.ALSO:A process for optical brightening of fibres composed of acrylonitrile polymers or copolymers thereof with a minor amount of another ethylenically unsaturated compound or of fibre mixtures, or mixed-fibre yarns, or mixed yarn fibrics containing such fibres, comprises treating the fibres with a non-quaternary compound having no dyestuff character, which is colourless or only slightly coloured and free from neutralized or free sulphonic or carboxylic acid groups, and which, in solution or on a substratum, fluoresces green-blue to violet in daylight or ultra-violet light, the compound having the formula <FORM:0824659/IV(c)/1> wherein A is a benzene radical which may be alkyl, alkoxy, amino, alkylamino, acylamino or halogen substituted, R is a radical with at least three conjugated double bonds which are also in conjugation with the -N = C< bond of the hetero ring, which radical may contain hetero atoms and may be constituted, at least in part, by a benzene ring or other cyclic structure, and B is a sulphur atom, an oxygen atom or the group >N-R1, in which R1 is a hydrogen atom or an alkyl, hydroxy alkyl or aralkyl radical.  Examples of the radical R include <FORM:0824659/IV(c)/2> Among the compounds specified are those which have the following formulae <FORM:0824659/IV(c)/3> where R2 is a thiophene ring attached at the 2,5 positions <FORM:0824659/IV(c)/4> The compounds may be applied to the fibres at any stage of production or to staple fibres, monofilaments, yarns or fabrics, as free bases or as acid addition salts which are capable of forming free bases, in aqueous solutions or dispersions which may contain soaps, polyglycol ethers of fatty alcohols or fatty amines, cellulose sulphite waste liquor or formaldehyde-naphthalene sulphonic acid condensates, which may be alkylated.  Treatment baths may be weakly acid or weakly alkaline and at temperatures up to boiling.  The compounds may be applied as adjuncts of other processes, viz: (a) in admixture with dyestuffs or as additions to dyebaths, discharge or reserve pastes, or for the aftertreatment of dyeings, prints or discharge prints, e.g. in the soaping process.  They may be applied in an acid medium containing azo dyestuffs free from sulphonic acid groups and which contain salt forming amino groups and are, at the most, partially hydrolysable.  In Example (9), an acrylonitrile fabric is treated at 90-100 DEG  C. in a bath containing the dyestuff <FORM:0824659/IV(c)/5> a  : b  - di - [- N - methyl - benzimidazolyl - (2) -]-ethylene and acetic acid; (b) in admixture with bleaching compounds or as additions to bleaching baths.  In Example (8), an acrylonitrile fabric is treated at 80 DEG  to 90 DEG  C. in a bath containing formic acid, sodium chlorite and a dispersion of a  : b  - di - [5 - methyl - benzoxazolyl-(2)]-ethylene obtained with a condensate of 30 mols. of ethylene oxide and a mixture of fatty alcohols, the majority of which have 18 carbon atoms; (c) in washing processes. Washing agents specified are soaps, sulphonated benzimidazoles substituted at the 2-carbon atom by higher alkyl radicals, salts of monocarboxylic acid esters of 4-sulphophthalic acid with higher fatty alcohols, salts of fatty alcohol sulphonates, alkylaryl sulphonic acids or condensates of higher fatty acids with aliphatic hydroxy- or amino-sulphonic acids and various non-ionic compounds.  The washing agents may also contain alkali metal carbonates, phosphates, pyrophosphates, polyphosphates, metaphosphates, silicates, perborates or percarbonates.  In Example (5), acrylonitrile fibres are washed in a liquid containing a  : b -di-[N-methyl - benzimidazolyl - (2)] - ethylene and soap or a detergent comprising soap, anhydrous sodium carbonate, sodium pyrophosphate, sodium perborate and magnesium silicate. Specifications 611,510 and 653,681 are referred to.ALSO:A process for optical brightening of fibres composed of acrylonitrile polymers or copolymers thereof with a minor amount of another ethylenically unsaturated compound comprises treating the fibres with a non-quaternary compound having no dyestuff character, which is colourless or only slightly coloured and free from neutralized or free sulphonic or carboxylic acid groups, and which, in solution or on a substratum, fluoresces green-blue to violet in daylight or ultra-violet light, the compound having the formula <FORM:0824659/IV (a)/1> wherein A is a benzene radical which may be alkyl, alkoxy, amino, alkylamino, acylamino or halogen substituted, R is a radical with at least three conjugated double bonds which are also in conjugation with the -N=C< bond of the hetero ring, which radical may contain hetero atoms and may be constituted, at least in part, by a benzene ring or other cyclic structure, and B is a sulphur atom, an oxygen atom or the group >N-R1 in which R1 is a hydrogen atom or an alkyl, hydroxy alkyl or aralkyl radical. Examples of the radical R include -CH=CH-CH=CH-CH=CH-CH=CH2 <FORM:0824659/IV (a)/2> Among the compounds specified are those which have the following formul <FORM:0824659/IV (a)/3> where A and B are as specified above and R2 is a thiophene ring in the 2,5 position <FORM:0824659/IV (a)/4> The compounds may be dispersed in the spinning mass or may be applied to the fibres at any stage of production as free bases or acid addition salts in aqueous solutions or dispersions which may contain soaps, polyglycol ethers of fatty alcohols or fatty amines, cellulose sulphite waste liquor or formaldehyde-naphthalene sulphonic acid condensates, which may be alkylated.  Treatment baths may be weakly acid or weakly alkaline and at temperatures up to boiling. Specifications 611,510 and 653,681 are referred to.