Stock material or miscellaneous articles – Coated or structually defined flake – particle – cell – strand,... – Particulate matter
Reexamination Certificate
2002-01-10
2003-10-28
Le, H. Thi (Department: 1773)
Stock material or miscellaneous articles
Coated or structually defined flake, particle, cell, strand,...
Particulate matter
C264S005000, C264S015000, C264S348000
Reexamination Certificate
active
06638619
ABSTRACT:
The present invention relates to a process for the production of granular material from a melt, and to the granular material itself.
Processes for the production of granular materials have already been described in the prior art. However, many of these processes have disadvantages, for example high equipment complexity. This equipment complexity is particularly high if the aim is to produce granular materials having, for example, a tablet-shaped geometry.
DE-C 32 09 747, for example, describes a process for the production of a granular material from a melt in which the crystal content of the melt is of very crucial importance. In order to be able to control this crystal content as well as possible, use is made of a pre-crystallizer, in which the melt has to be enriched with crystal nuclei.
DE-C 196 37 380 discloses the production of neopentyl glycol hydroxypivalate granules. In this process too, the crystal content of the melt is of essential importance. The crystal content is achieved in this process either by adding additional solid to the melt or, as in DE-C 32 09 747, by using a pre-crystallizer. A two-phase mixture having a certain content of crystals has to be produced in this pre-crystallizer. In this case, the equipment complexity is likewise very high since, in addition to the pre-crystallization, measures have to be taken to ensure a certain degree of homogeneity of the 2-phase mixture.
It is an object of the present invention to provide a process which allows the production of a tablet-shaped granular material and which does not have the disadvantages of corresponding processes from the prior art.
We have found that this object is achieved by a process for the production of a tablet-shaped granular material from a melt, in which
(i) a melt is prepared,
(ii) the prepared melt is shaped to give droplets,
(iii) the droplets are deposited on a cooling surface, and
(iv) the deposited droplets solidify to give the granular material, wherein the melt comprises an alcohol, and the melt has a melting point of 30° C. or above.
The present invention likewise relates to the tablet-shaped granular material which can be produced by a process in which
(i) a melt is prepared,
(ii) the prepared melt is shaped to give droplets,
(iii) the droplets are deposited on a cooling surface, and
(iv) the deposited droplets solidify to give the granular material, wherein the melt comprises an alcohol, and the melt has a melting point of 30° C. or above.
The term “tablet-shaped granular material”, as used in the context of the present application, describes a granular material with a circular to oval outline whose underside is flat and whose upper side is flat to convex.
Regarding the alcohol present in the melt, there is generally no restriction so long as the melt comprising the alcohol has a melting point of 30° C. or above, preferably a melting point of 40° C. or above. In particular, the alcohol can be a linear, branched or cyclic substituted or unsubstituted alcohol. Conceivable here are both monools and polyols, which may in turn be monomeric, oligomeric or polymeric.
It is of course also conceivable for the melt to comprise two or more alcohols.
In a preferred embodiment, the present invention relates to a process as described above wherein the alcohol is selected from the group consisting of
(a) an alcohol (B) which is prepared by a process which comprises the following stages (I) to (III):
(I) reaction of at least one alkali or alkaline earth metal hydroxide with at least one alcohol (A) in at least one organic solvent (L) to give a mixture (G-I) comprising at least the alcohol (A), the solvent (L) and an alkoxide (AL);
(II) reaction of at least one carbonyl compound of the general structure R—CO—R′ with at least one alkyne of the general structure R″—C≡C—H and the mixture (G-I) obtained in stage (I) to give a mixture (G-II) comprising at least the alcohol (A), the solvent (L) and an unsaturated alcohol (B);
(III) distillation of the mixture (G-II) obtained in stage (II) to give the at least one alcohol (B) and a mixture (G-Ill) comprising the solvent (L) and the alcohol (A),
where the solvent (L) obtained in stage (III) and the alcohol (A) obtained in stage (III) are recycled into stage (I) as a mixture,
(b) an alcohol (C) which is prepared by a process which comprises the following stages (I) to (III′):
(I) reaction of at least one alkali or alkaline earth metal hydroxide with at least one alcohol (A) in at least one organic solvent (L) to give a mixture (G-I) comprising at least the alcohol (A), the solvent (L) and an alkoxide (AL);
(II) reaction of at least one carbonyl compound of the general structure R—CO—R′ with at least one alkyne of the general structure R″—C≡C—H and the mixture (G-I) obtained in stage (I) to give a mixture (G-II) comprising at least the alcohol (A), the solvent (L) and an unsaturated alcohol (B);
(II′) hydrogenation of at least one unsaturated alcohol (B) in the mixture (G-Il) obtained from stage (II) to give a mixture (G-II′) comprising at least one hydrogenated alcohol (C), the alcohol (A) and the solvent (L);
(III′) distillation of the mixture (G-II′) obtained in stage (II′) to give the at least one alcohol (C) and a mixture (G-III′) comprising the solvent (L) and the alcohol (A),
where the solvent (L) obtained in stage (III′) and the alcohol (A) obtained in stage (III′) are recycled into stage (I) as a mixture, and
(c) a mixture of two or more thereof.
There are no particular restrictions regarding the preparation of the mixture (G-I) in stage (I), which comprises the solvent (L), the alcohol (A) and the alkoxide (AL). It must merely be ensured that (L) and (A) can be added together as starting materials.
In a preferred embodiment, stage (I) is carried out in one or more distillation columns in which the at least one alkoxide is prepared by azeotropic drying. It is possible here, for example, to supply (L) and (A) as a single starting-material stream already in the form of a mixture. However, it is likewise possible to supply (L) and (A) separately and only to combine the streams in the at least one column. It is of course also possible to employ a plurality of suitable solvents (L) and/or a plurality of suitable alcohols (A). It is conceivable here to feed these to the at least one column in a single starting-material stream or in two or more starting-material streams which comprise the respective solvents (L) and/or the respective alcohols (A).
In addition to (L) and (A), an aqueous solution of one or more alkali and/or alkaline earth metal hydroxides in one or more starting-material streams is added as further starting material. The use of alkali and/or alkaline earth metal hydrides and/or alkali and/or alkaline earth metal alkyl compounds is also conceivable in this connection.
If it should be necessary for the purposes of the present invention, the individual starting-material streams can of course be brought to the desired temperature before the pre-mixing. Such preheating is possible in all conceivable processes.
Removal of water by distillation during performance of stage (I) from the at least one alcohol (A) and the at least one alkali and/or alkaline metal hydroxide gives a mixture comprising at least one alkali or alkaline earth metal alkoxide and the at least one organic solvent (L). This mixture is preferably obtained from the still of the column used.
In the further course of performance of stage (I), the excess at least one alcohol (A) is removed from this mixture by distillation. This removal can be carried out either in the same column in which the at least one alkoxide was prepared or in one or more downstream columns. In a preferred embodiment of the present invention, stage (I) is carried out in a single column in which both water and the at least one alcohol (A) are distilled off.
In the present invention, sufficient alcohol (A) is removed so that the mixture resulting after the removal of water and the incomplete removal of the at least one al
Brunner Melanie
Heilek Jörg
Lorenz Rudolf Erich
Maltry Bernhard
BASF - Aktiengesellschaft
Keil & Weinkauf
Le H. Thi
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