FR2645164A1 - PROCESS FOR PRODUCING DYE GRANULES - Google Patents

Abstract

The invention relates to the production of dye granules. Dye powders, having a water content of 5 to 15% by weight, are subjected to extrusion granulation. The extrusion is carried out by means of a flat die press resulting in strands which are cut to the desired length. Application: improved process for producing granules of colorants in cylindrical form.

Description

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  The subject of the present invention is the production

  dye granules, in a cylindrical form, which, in addition to the dye, optionally contain

  dispersing agents, diluents,

  sippers, emulsifiers, granulation liquid, etc. The cylindrical granules preferably have a diameter of 1 to 3 mm and a length of 2 to mm. Particularly preferred granules possess a

  diameter of about 2 mm and a length of 5 to 10 mm.

  In factories where dyes are used, for example in the textile industry, dyes of the most diverse types are needed. The dyes are mainly used under foaming powders. However, this has various disadvantages. The most important disadvantage is the significant formation, in some cases, of dust from the powder, with the further fact that it is very difficult to disperse and dissolve the powder in the water as it disperses poorly and tends to form lumps. In addition, the powder can not be used for dosing units and has a large packing volume due to its relatively low bulk density. If the dye is granulated, a number of advantages result. The granules, for example cylindrical granules, can be easily thrown into the water present in the container used and dissolve or disperse in a short time without formation of lumps or adhesion to the walls of the container. The granules are suitable for dosing units since they have good flow properties and remarkable dosing properties, do not stick to each other and do not adhere to the walls of the hoppers. The apparent density is 1.5 to 2 times higher than that of the powder, thus resulting in

  considerable savings in packaging.

  Other advantages over the powder and other granulation processes are: - low investment costs - small volume required for the extrusion unit - high production capacity - minimal costs maintenance - rapid substitution of a product - low labor requirements - low energy costs no variation in product quality - lack of lumps The disadvantage of known cylindrical granules is their low resistance to abrasion which results, inter alia, in unwanted dust formation. It has now been found that these disadvantages can be avoided if dye powders having a specific degree of residual moisture are granulated by

extrusion.

  Accordingly, the present invention relates to a process for producing dyes granules in cylindrical form, characterized in that the dyestuff powders have a water content of 5 to 10, preferably 7 to 12, percent by weight. , and are subject to

extrusion granulation.

  The dyes present in the granules,

  in accordance with the claims, may belong to

  various categories such as, for example, azo dyes, anthraquinone dyes, dyes derived from triphenylmethane, sulfur dyes, pigments, dyes derived from methines

  and dyes derived from triarylmethanes.

  Water-soluble dyes for the textile industry, the paper industry and the leather industry are preferred. Reactive dyes and acid dyes

  non-reactants are particularly preferred.

  Suitable dispersing agents which may be present in the dye preparations are: surfactants of the group comprising fused aromatic sulphonic acids such as, for example, naphthalenesulfonic acid / formaldehyde condensation products and lignin sulphonates, etc .; (refer, for example, to

DE-A-2317175).

  Suitable diluents are preferably inorganic salts such as, for example, sodium, magnesium and potassium sulphates, sodium and potassium chlorides, monosodium phosphates and the like.

disodium and borax.

  Dusts which may be mentioned are: dibutyl phthalate, diethyl phthalate, fatty alcohols, polyethers and mineral oils. Suitable emulsifiers are amines

and alkoxylated fatty alcohols.

  The preferred granulation liquid is water.

  The cylindrical granules have, for example, the following composition: 1. Types of acid dyes 65.0 - 75.0% of dye 0.0 - 10.0% of diluents 0.4 - 0.8% of dust removers 0.1 - 0.2% emulsifier, and, 0 - 15.0% water 2. Types of reactive dyes, 0 - 85.0% dye 0.0 - 60.0% dispersing agents 0.0 - 60.0% diluents 0.4 - 1.2% dust removers 0.1 - 0.3% emulsifiers, and, 0 - 15.0% water, the sum of the weights constituents being in each case

equal to 100% by weight.

  The starting materials for the production of granules are dyes in the form of powders which form a small to very small amount of dust. The powders are obtained, for example, by spray drying the aqueous filter cakes to which

  adjuvants were optionally added.

  Flat matrix presses produced by Amadeus KAHL GmbH & CO., D-2057 Reinbek bei Hamburg, have proved to be suitable machines for the implementation of

process.

  The KAHL press operates by extrusion agglomeration using a flat matrix and cylinders as compression tools. The dye powder is introduced vertically, in a measured amount, from above into the press chamber and forms a layer of material on the matrix. The rollers roll on this layer and cause its compaction. The compression force increases constantly as the rolls roll in the direction of the press channel until it has become so high that the product is compressed by the rotating rolls through the die ejection grid and is shaped to form endless strands of uniform density. The adjustable cutting device beneath the die cuts the shaped strands to the desired length. It is not usually

  necessary to then dry the granules.

  The process can be used in a

  continuous and discontinuous.

  It goes without saying that the present invention has been described only for explanatory purposes, but in no way limiting, and that many modifications can be made to it.

without leaving his frame.

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Claims (4)

  A process for producing colorant granules in cylindrical form, characterized in that dyestuff powders having a water content of 5 to 15% by weight are extrusion granulated. 2. Process according to claim 1, characterized in that the cylindrical granules possess   a diameter of 1 to 3 mm and a length of 2 to 15 mm.   3. Process according to claim 1, characterized in that the extrusion granulation is   performed using a flat matrix.   4. A process for the production of dyes granules in cylindrical form, characterized in that dye powders having a water content of 5 to 15% by weight are subjected to extrusion agglomeration and the shaped strands are cut to length desired without subsequent drying.