Granular compacts

Details Granular compacts Granular compacts

2001-08-17

2003-10-14

Einsmann, Margaret (Department: 1751)

Bleaching and dyeing; fluid treatment and chemical modification

Organic additive for dye composition, dye composition...

Polymeric additive

C008S526000, C008S576000, C008S577000

Reexamination Certificate

active

06632255

ABSTRACT:

For the selling of dyes, these substances are commonly formulated to specific concentrations of active substance and in a most readily usable form. Water-soluble dyes can be formulated, for example, in liquid form as concentrated solutions or dispersions, which offers certain advantages in terms of the metering of the products but which on the other hand entails the handling of a large amount of liquid on transportation and storage, which not only occupies transport and storage volume but also, should the containers suffer any damage and the liquid formulation run out, leads to the corresponding consequences. In order to avoid these problems as far as possible, the said water-soluble dyes can be formulated also as dry products, for example as powders, granules or shaped compacts (tabletted/briquetted or spherical/pelletized). The pulverulent products are often not sufficiently free-flowing and/or tend strongly towards dusting and, occasionally, to accretion as well, which when the containers are handled and the products are used to prepare the corresponding dyeing baths may lead to corresponding instances of contamination and product loss. To reduce these disadvantages granules have been prepared, principally hollow spheres (via atomizer) or built-up granules, especially fluidized-bed granules. Although there is less dusting with these granules, the mutual abrasion of the individual particles or the bursting of the hollow spheres in the course, for example, of transportation, transfer, etc., may likewise result in powder or dust, so that again when handling the products a certain level of dusting may be caused and/or downwards-flowing abraded powder accumulates in the bottom part of the container and, consequently, the consistency of the product in the container as a whole is not uniform. Fluidized-bed granules, although they do not share with the hollow spheres the disadvantage that they may burst, are fairly laborious to prepare: for the preparation of the fluidized-bed granules the products along with at least a portion of the additives must be admixed with water and then dried in a fluidized-bed granulator, which may have an adverse effect on thermally unstable products as a result, for example, of the heating, and may in addition be disadvantageous for those products which may become tacky under such conditions. Owing to the relatively large amount of voids in the individual grain of the structured granules, a fairly large proportion of any dustproofing agent added penetrates into the voids before an effective amount thereof is present on the exterior surface of the granule. If to circumvent these problems the dyes are then formed as coarsely granular compacts (briquettes or pellets, with a size, for example, of from 3 to 10 mm) there may occur the disadvantage of a reduced and irregular rate of dissolution of the active substance in the compacts, with the additional possibility again of powder and dust forming in the packaged dye as a result of capping of the particles.
In EP-A-0115634 and in EP-A-0612537 there are described certain machines, with which dry products, e.g. dyes may be sprayed with dedusting agents. In EP-A-0115634 is described the treatment of abrasion sensitive products, e.g. of spray dried dyes or of dyestuff hollow beads, in a turning tubular mixer; in EP-A-0612537 is described the treatment of fine particle size solids, among else of dyestuff powders and granules, with a liquid, e.g. a dedusting agent, in a mixer provided with an ultrasonic atomizer.
In EP-A-0028379 and 0264049, FR-A-2387270 and DE-A-3248504 is described the production of water soluble granules by build-up granulation. In FR-A-2387270 (=DE-A-2716478) and in DE-A-3248504 there are described fluidized-bed granulators. In EP-A-0028379 is described the production of fluidized-bed granules by employing certain granulating adjuvants. In EP-A-0264049 is described a multiple stage production of dye build-up granules by mixing-granulation and fluidized-bed drying, while in the introduction of this EP there are indicated some disadvantages of fluidized-bed granulation (such as prolonged permanence and—for the production of high tonnage—large, costly machines).
In U.S. Pat. No. 5,507,991 is described the production of extrudates from a water/dye mixture (produced by mixing spray dried FD&C dye with water), where after extrusion a drying—e.g. during several hours in an oven at 90 to 130° C.—is required in order to eliminate again the added water; such extrudates, due to their elongated (mostly cylindrical) shape or/and due to the porosity resulting by the water evaporation in drying, are however not particularly stable, and in transportation and transfer they may break rather easily and consequently dust is also formed. In this U.S. Pat. No. 5,507,991 in the introduction (column 2, lines 55-60) there is also indicated that compaction and granulation products are highly vulnerable to the effects of abrasion and disintegration, which means that they would not be usable in practice. From FR- A-2645164 is known an extrusion of nearly dry product, in which before extrusion a dedusting agent is also admixed; these extrudates are however of a less dense packing and consequently are also less stable and tend still more to breaking in moving (transportation, transfer from one vessel to another).
In FR-A-2373591 is described the production of dye powders of low dust content by admixture of an adhesive, a dust agglomerating agent and a preheated salt and of further additions, where there is also incidentally mentioned that the produced dye compositions may optionally be compacted.
In U.S. Pat. No. 3,034,848 there is described the compaction of certain dyes which are soluble in gasoline but not soluble in water.
From CH-A-492007 it is known to mix dyestuff powder in the presence of ice shivers and of a binder, by which there are obtained non-compacted crumby products of very fine particle size; this physical form is aimed at in order to achieve a sufficient solubility and speed of dissolution, while the production of larger sized particles, such as granules, briquettes and tablets, is designated as being of disadvantage due to their bad solubility in water and their properties deviating from those of the starting products (column 1, lines 25-30).
In DE-A-3248504 there is described a process for the production of fluidized-bed granules of water soluble substances, among else of dyes, and the introduction of the description (page 3, 2nd paragraph) advises against particles with a hard surface (these comprise for instance the above mentioned tablets and briquettes, but also in general further compaction or extrusion products) because these dissolve very badly, so that the required speed of dissolution is not achieved.
In WO 99/05226 compacted granular products containing water-soluble dye or optical brightener are described, which, however are not completely satisfactory with regard to their stability, especially after repeated transportation or storage for a longer period of time.
There is therefore a need for a dye formulation, which does not have these drawbacks.
It has now, surprisingly and despite the above mentioned prejudices, been found that granules of water-soluble dyes, obtainable by dry compaction (densification), especially by means of roll presses, and granulation, as are described and defined below, are notable for their stability and rate of dissolution and for their low dust content even after repeated transportation and transfer of the drums or packs, it being possible to avoid the laborious mixing with water and evaporation required for fluidized-bed granules.
The invention relates to the compacted granular products, their production and their use.
The invention therefore firstly provides a compacted granulated product (G) of a mixture of
(A) at least one water-soluble dye,
(B) at least one extender, and
(C) at least one compound of formula
 wherein
R is a saturated or unsaturated aliphatic residue with 12 to 22 carbon atoms,
R
1
, R
2
, R
3
and R
4
independently of one anothe

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