EP0060468B1 - Process for the dyeing of paper and dyed paper - Google Patents

Description

• X(+) eine gegebenenfalls substituierte Ammoniumgruppe,
• m 0 oder 1,
• R Wasserstoff, Halogen, C, - bis C4-Alkyl, C₁- bis C₄-Alkoxy, Hydroxy, Amino, Sulfon- und Carbonamido oder Acylamino,
• R₁ Wasserstoff, C₁- bis CQ₄-Alkyl, Halogen oder C₁- bis C₄-Alkoxy,
• R₂ und R₃ unabhängig voneinander Wasserstoff, C₁- bis C₃-Alkyl, C₁- bis C₄-Alkoxy oder Acylamino, und
• An(-) ein Anion bedeuten,

worin an Ring a weitere carbocyclische oder heterocyclische Ringe ankondensiert sein können, die ihrerseits durch R substituiert sein können, sowie Mittel, die diese Farbstoffe enthalten.The invention relates to processes for dyeing paper with cationic azo dyes of the formula

• X (+) an optionally substituted ammonium group,
• m 0 or 1,
• R is hydrogen, halogen, C ₁ -C ₄ -alkyl, C ₁ -C ₄ alkoxy, hydroxy, amino, sulfone and carbonamido or acylamino,
• R _{1 is} hydrogen, C ₁ to CQ ₄ alkyl, halogen or C ₁ to C ₄ alkoxy,
• R ₂ and R ₃ independently of one another are hydrogen, C ₁ to C ₃ alkyl, C ₁ to C ₄ alkoxy or acylamino, and
• An (-) is an anion

in which further carbocyclic or heterocyclic rings may be fused to ring a, which in turn may be substituted by R, and agents which contain these dyes.

Alkylene is in particular a radical having 1 to 3 carbon atoms. Acylamino is preferably understood to mean C ₁ to C ₃ alkylcarbonylamino, C ₁ to C ₃ alkylsulfonylamino, aminocarbonylamino or benzoylamino, optionally substituted by halogen or an ammonium group, but especially acetylamino, propionylamino or aminocarbonyl.

Halogen is preferably chlorine or bromine.

hervorzuheben, worin

• R, R₁, R₂, R₃ und An(-) die in Formel (I) angegebene Bedeutung haben,
• n 0 bis 2,
• R₄, R_s und R_e unabhänging voneinander Wasserstoff, C₁- bis C₄-Alkyl, C₃- oder C₄-Alkenyl, Benzyl oder Phenylethyl, die durch Hydroxy, C₁- bis C₄-Alkoxy, Chlor oder Cyan und der Benzyl-und Phenylethylrest zusätzlich durch C, - bis C₄-Alkyl substituiert sein können, bedeuten, oder
• R₄ und R₅ zusammen mit dem Stickstoffatom einen gegebenenfalls durch C₁- bis C₄-Alkyl substituierten Piperidin-, Morpholin-, Piperazin- oder Pyrrolinring, oder
• R₄, R₅ und R_e zusammen mit dem Stickstoffatom, an das sie gebunden sind, einen gegebenenfalls durch C₁- bis C₄-Alkyl substituierten Pyridinring bilden.
• Besonders geeignet sind Farbstoffe der Formel (II), worin
• R für Wasserstoff, Methyl, Sulfon- oder Carbonamido, Aminocarbonylamino oder gegebenenfalls durch Halogen oder die Gruppe
  
  substituiertes Acetylamino oder Propionylamino,
• R₁ für Wasserstoff, Methyl, Chlor oder Methoxy,
• R₂ und R_a unabhängig voneinander für Wasserstoff, Methyl, Methoxy, Aminocarbonylamino oder gegebenenfalls durch Halogen oder die Gruppe
  
  substituiertes Acetylamino oder Propionylamino,
• R₄, R_s und R_e unabhängig voneinander für Methyl, Ethyl, Hydroxyethyl, Chlorethyl, Cyanethyl, Benzyl, Allyl oder zusammen mit dem Stickstoffatom für einen gegebenenfalls durch Methyl substituierten Pyridinring stehen.

Of the dyes of formula (I) are the dyes of formula

to emphasize in what

• R, R ₁ , R ₂ , R ₃ and An (-) have the meaning given in formula (I),
• n 0 to 2,
• R ₄ , R _s and R _e independently of one another are hydrogen, C ₁ - to C ₄ -alkyl, C ₃ - or C ₄ -alkenyl, benzyl or phenylethyl, which are substituted by hydroxy, C ₁ - to C ₄ -alkoxy, chlorine or cyano and the benzyl and phenylethyl radical can additionally be substituted by C 1 -C ₄ -alkyl, or
• R ₄ and R ₅ together with the nitrogen atom represent a piperidine, morpholine, piperazine or pyrroline ring which is optionally substituted by C ₁ -C ₄ -alkyl, or
• R ₄ , R ₅ and R _e together with the nitrogen atom to which they are attached form a pyridine ring which is optionally substituted by C ₁ -C ₄ -alkyl.
• Dyes of the formula (II) in which
• R represents hydrogen, methyl, sulfone or carbonamido, aminocarbonylamino or optionally by halogen or the group
  
  substituted acetylamino or propionylamino,
• R _{1 represents} hydrogen, methyl, chlorine or methoxy,
• R ₂ and R _a independently of one another for hydrogen, methyl, methoxy, aminocarbonylamino or optionally by halogen or the group
  
  substituted acetylamino or propionylamino,
• R ₄ , R _s and R _e independently of one another represent methyl, ethyl, hydroxyethyl, chloroethyl, cyanoethyl, benzyl, allyl or together with the nitrogen atom represent a pyridine ring which is optionally substituted by methyl.

Anions An (-) are the colorless organic and inorganic anions customary for cationic dyes, for example chloride, bromide, iodide, hydroxide, hydrogen sulfate, sulfate, nitrate, dihydrogen phosphate, phosphate, carbonate, perchlorate, fluoroborate, chlorozincate, methosulfate, ethosulfate, acetate, Propionate, lactate, citrate, benzenesulfonate and toluenesulfonate.

The anion is generally given by the manufacturing process. The dyes are preferably present as chlorides, hydrogen sulfates, sulfates, methosulfates, phosphates, acetates, lactates, citrates. The anions can be exchanged for other anions in a known manner and can be present as mixtures.

The dyes (I) are used for dyeing paper either as dye-powder preparations or preferably in the form of concentrated dye solutions. Powder preparations are made in the usual way with coupé agents such as sodium sulfate, phosphates, chloride, acetate or are marketed as spray drying brands. The concentrated dye solutions can be of an aqueous or aqueous / organic type, with customary environmentally friendly and readily degradable organic additives being preferred, such as organic acids such as acetic acid, formic acid, amides such as formamide, dimethylformamide, urea, alcohols such as glycol, diglycol, diglycol ether, especially the latter Methyl or ethyl ether. The concentrated dye solutions are prepared in a conventional manner, for example by dissolving the dye (as a paste or powder) in a suitable solvent or solvent mixture.

The dye powders or solutions are generally used after dilution with water for the continuous or discontinuous dyeing of paper.

The dyes are used for paper pulp dyeing or for paper surface dyeing. They are suitable for sized and unsized paper types based on bleached or unbleached pulp of different origins such as softwood or hardwood, sulfite and / or sulfate pulp.

The dyeing is preferably carried out at pH values from 4 to 8, in particular pH 5 to 7. The dyeing temperature is generally 10 to 50, preferably about 20 ° C. (room temperature).

The auxiliaries and fillers customary in paper dyeing and production can also be used when using the dyes according to the invention.

The dyes have excellent drawability when coloring paper.

The paper dyeings obtained with the dyes according to the invention are notable for very good fastness to water (fastness to bleeding) and fastness to acids, alkali and alum.

Attention should also be drawn to the brilliance and clarity of the color tones. The combination behavior with suitable dyes is also very good.

The dyes of the formula (I) are known, for example from US Pat. No. 602637, DE-PS No. 93499, DE-PS No. 95530 and DE-AS No. 1005486, and have hitherto been used for dyeing tannic cotton, half-wool and polyacrylonitrile used. It is therefore surprising that in the case of paper dyeing, even without auxiliaries, they produce almost colorless waste water with good wet fastness properties of the dyeings obtained.

worin X(+) m, R, , R₂, R₃ und An(-) die in Formel (I) angegebene Bedeutung haben,

• diazotiert und mit Verbindungen der Formel
  
  worin R und Ring a die in Formel (I) angegebene Bedeutung haben, kuppelt.

The use of cationic azo dyes for dyeing paper is known, for example, from EP _- A No. 0024321. The dyes of the formula (I) are prepared by, in a known manner, aminoazo compounds of the formula

wherein X (+) m, R, R ₂ , R ₃ and An (-) have the meaning given in formula (I),

• diazotized and with compounds of the formula
  
  wherein R and ring a have the meaning given in formula (I), couples.

example 1

A desiccant consisting of 60% wood pulp and 40% unbleached sulfite pulp is beaten with water in the Dutch and ground to a degree of 40 ° SR so that the dryness is a little over 2.5%, and then with water to an exact 2.5% dryness of the thick matter adjusted.

versetzt, ca. 5 min verrührt, 2% Harzleim und 4% Alaun (bezogen auf Trockenstoff) zugegeben und wiederum einige Minuten homogen verrührt. Man verdünnt dann die Masse mit ca. 500 Teilen Wasser und stellt hieraus in üblicher Weise durch Absaugen über einen Blattbildner Papierblätter her. Die Papierblätter weisen eine kräftige blaustichig rote Färbung auf. Das Abwasser der Färbung ist praktisch farbstoffrei.200 parts of the thick matter are mixed with 5 parts of a 0.5% aqueous solution of the dye of the formula

added, stirred for about 5 min, 2% resin glue and 4% alum (based on dry matter) were added and again homogeneously stirred for a few minutes. The mass is then diluted with about 500 parts of water and paper sheets are produced from it in the usual manner by suction through a sheet former. The paper sheets have a strong bluish red color. The wastewater from the dyeing is practically dye-free.

When dyeing unsized paper pulp under otherwise identical dyeing conditions, a strong bluish-red dyeing with practically dye-free waste water is also obtained.

If bleached sulphite pulp is used to produce the thick material and this thick material is used for dyeing, the processes described above give blue-tinged red paper dyeings and practically dye-free waste water.

If, instead of the above dye, appropriate amounts of the dyes or dye solutions described in the examples below are used, paper colorations are obtained, the nuances of which are indicated in the individual dye examples.

Claims (4)

1. Process for dyeing paper with azo dyestuffs containing ammonium groups, characterised in that the azo dyestuffs used are those of the formula

X(+) denotes an optionally substituted ammonium group,

m denotes 0 or 1,

R denotes hydrogen, halogen, C₁- to C₄-alkyl, C₁- to C₄-alkoxy, hydroxyl, amino, sulphonamido and carboxamido, or acylamino,

R₁ denotes hydrogen, C₁- to C₄-alkyl, halogen or C₁- to C₄-alkoxy,

R₂ and R₃ independently of one another denote hydrogen, C₁- to C₄-alkyl, C, - to C₄-alkoxy or acylamino, and

An(-) denotes an anion,

wherein further carbocyclic or heterocyclic rings, which can in their turn be substituted by R, can be fused to ring a.

2. Process according to Claim 1, characterised in that cationic azo dyestuffs of the formula

wherein

R, R₁, R₂, R₃ and Anc(-) have the meaning indicated in Claim 1,

n denotes 0 to 2,

R₄, R₅ and R₆ independently of one another denote hydrogen, C₁- to C₄-alkyl, C₃- or C₄- alkenyl, benzyl or phenylethyl, which can be substituted by hydroxyl, C₁- to C₄-alkoxy; chlorine or cyano, and the benzyl and phenylethyl radical can, in addition, be substituted by C₁- to C₄-alkyl, or

R₄ and R₅, together with the nitrogen atom, form a piperidine morpholine, piperazine or pyrroline ring which is optionally substituted by C₁- to C₄-alkyl, or

R₄, R₅ and R₆, together with the nitrogen atom to which they are bonded, form a pyridine ring which is optionally substituted by C₁- to C₄-alkyl, are used.

3. Process according to Claim 1, characterised in that cationic dyestuffs of the formula of Claim 2 are used, wherein

R represents hydrogen, methyl, sulphonamido or carboxamido, aminocarbonylamino or acetylamino or propionylamino which is optionally substituted by halogen or the group

R, represents hydrogen, methyl, chlorine or methoxy,

R₂ and R₃ independently of one another represent hydrogen, methyl, methoxy, aminocarbonylamino or acetylamino or propionylamino which is optionally substituted by halogen or the group

R₄, R₅ and R₆ independently of one another represent methyl, ethyl, hydroxyethyl, chloroethyl, cyanoethyl, benzyl, allyl, or, together with the nitrogen atom, a pyridine ring which is optionally substituted by methyl.

4. Paper, characterised in that it has been dyed with a cationic azo dyestuff of Claim 1.