Hydrophobicized double layer hydroxide compounds

Details Hydrophobicized double layer hydroxide compounds Hydrophobicized double layer hydroxide compounds

1993-04-29

1994-07-05

Dees, Jose G.

Organic compounds -- part of the class 532-570 series

Organic compounds

Heavy metal containing

556 31, 556 49, 556 61, 556114, 556131, 556149, 534 16, C07F 1900, C07F 506, C07F 302, C07F 306

Patent

active

053268911

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

This invention relates to new hydrophobicized double layer hydroxide compounds, to a process for the production of these compounds by reaction of double-layer hydroxides with aliphatic mono- and/or dicarboxylic acids in an organic solvent or in a kneader and to the use of the hydrophobicized double layer hydroxide layer compounds as alkoxylation catalysts for compounds containing active H atoms or for fatty acid esters.


PRIOR ART

Two-dimensional inorganic polycations with intracrystalline charge equalization by mobile interlayer anions are also known as "double layer hydroxide compounds" and have been repeatedly described in the literature (Chimia 24, 99 (1970)). Chemically, these compounds are mixed hydroxosalts of 2- and 3-valent metal cations and may be characterized by the following general formula:
Certain properties of this class of compounds, for example their use as a catalyst material, as ion exchangers and certain medicinal applications, have been summarily described by W. T. Reichle (CHEMTECH, Jan. 1986, 58). Various methods for the production of these compounds on an industrial scale are described in DE-OS 20 61 156.
A well-characterized representative of this class of compounds is hydrotalcite which occurs naturally as a mineral. Synthetic hydrotalcites are also known and are described, for example, in DE-C-15 92 126, DE 33 46 943 A1, DE 33 06 822 A1 and EP 0 207 811 A1. Hydrotalcite is a natural mineral having the following ideal formula: Brucite crystallizes in a layer structure with the metal ions in octahedral vacancies between two layers of close-packed hydroxyl ions, only every second layer of the octahedral vacancies being occupied. In hydrotalcite, a few magnesium ions are replaced by aluminium ions so that the layer packet receives a positive charge. This is equalized by the anions which are present in the interlayers together with zeolitic water of crystallization.
The following are mentioned as other typical representatives of this class compounds:


______________________________________ magaldrate (Mg.sub.10 Al.sub.5 (OH).sub.31)(SO.sub.4).sub.2 * n H.sub.2 O, pyroaurite (Mg.sub.6 Fe.sub.2 (OH).sub.16)CO.sub.3 * 4.5 H.sub.2 O and hydrocalumite (Ca.sub.2 Al(OH).sub.6)NO.sub.3 * n H.sub.2 O. ______________________________________
Calcined hydrotalcites have already been used with excellent results as ethoxylation and propoxylation catalysts (DS 38 43 713 A1). However, they are attended by the disadvantage that they have to be converted from the natural and synthetic hydrotalcites into a calcined form suitable for catalytic purposes by heating for several hours at temperatures of, for example, 400.degree. to 600.degree. C. In addition, calcined compounds are sensitive to traces of water and to the carbon dioxide from the air (reverse reaction of calcination), so that their range of applications and their stability in storage are limited due to the loss of activity.
According to DE 30 19 632 A1, U.S. Pat. No. 4,761,188, EP 0 142 773 A1, EP 0 189 899 A1, EP 0 256 872 A1, hydro-phobicized hydrotalcites formed by the treatment of hydrotalcite with anions of acids, for example fatty acids, have already been used as stabilizers for thermoplastic resins. This surface treatment is carried out with anionic surface-active agents in a quantity of 1 to 10% by weight, based on the hydrotalcite.
In addition, it is known from the teaching of DE 37 31 919 A1 that compounds having the general formula Al.sub.x Mg.sub.y (OH).sub.35-z R.sub.z * n H.sub.2 O, in which R is the anion of a monocarboxylic acid, may be used as thickeners, thixotropic agents, stabilizers or anti-sedimentation agents. The compounds disclosed in this document are prepared by a complete exchange of sulfate ions for monocarboxylic acid ions using an aqueous suspension of the alkali salt of the monocarboxylic acid.
DE 40 10 606 A1 describes hydrophobicized hydro-talcite compounds having the general formula Mg.sub.x Al(OH).sub.y --(CO.sub.3).sub.m (A).sub.n * z H.sub.2 O, in which A stands for

REFERENCES:
patent: 4351814 (1982-09-01), Miyata et al.
patent: 4761188 (1988-08-01), Miyata
Chimia 24, (1970), pp. 99-108.
Chemtech, (1986), pp. 58-63.
Jaocs 63, (1986), pp. 691-695.
Happi, (1986), pp. 52-54 and 123.

Affiliated with

Also associated with

Rating

Hydrophobicized double layer hydroxide compounds does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Hydrophobicized double layer hydroxide compounds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydrophobicized double layer hydroxide compounds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-797107