Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Patent
1996-06-12
1998-02-24
Acquah, Samuel A.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
524442, 524445, 524787, 524789, 568680, 568619, 568698, 549347, 549352, 549353, C08K 334
Patent
active
057213054
DESCRIPTION:
BRIEF SUMMARY
This application claims benefit of international application PCT/EP94/03978, filed Nov. 30, 1994.
The present invention relates to a process of preparing polymers of glycerol in which glycerol or its derivatives isopropylidene glycerol (or 2,2-dimethyl-1,3-dioxolane-4-methanol), glycidol and glycerol carbonate are polymerized in the presence of a clay.
Such a process is known from Japanese Patent Application JP-A-61/238,749 (Nippon Oils and Fats Co. Ltd) in which a process has been described of manufacturing polyglycerol, with only small amounts of cyclic polymerization products. In this process glycerol is condensed after addition of 0.1-5% by weight of alkali catalyst and the same amount of an aluminium oxide comprising adsorbent. Examples of the adsorbent of the aluminium oxide type are activated alumina, zeolite, synthetic adsorbents, and also activated clays. The activated clay which has been mentioned is V.sub.2 Super (ex. Mizusawa Kagaku, Japan, containing 10.4% by weight of alumina), but any further indication has not been given. The aluminium oxide type adsorbent is stated to provide a decolorizing effect during the reaction and also to exhibit a catalytic effect in that it prevents the formation of cyclic polymers of glycerol. In examples 1,2,4,5 and 7 the activated clay is used together with sodium carbonate or sodium hydroxide as the alkali catalyst. In the product compositions indicated for the examples with activated clay, the amount of cyclic polymer in the final product still ranges from 6.9 to 10.1% by weight.
In British Patent Specification GB-A-1,308,412 (Atlas Chemical Industries) crude polyglycerols are purified by contacting them with an inert, finely divided solid, such as silica, alumina, diatomaceous earth or Fullers earth at a pH of 10 to 12, after which the solid and liquid phase of the obtained slurry are separated and the liquid phase is passed throuh an anion exchange resin and subsequently through a cation exchange resin.
In our co-pending European Patent Application EP 93200356.9 (Unilever; meanwhile published as International Patent Applicatio WO-A-94/18259) we have described a process of polymerizing glycerol in the presence of an acid zeolite having an average pore size of at least 0.6 nm, in which process preponderantly cyclic polymers are formed.
It has now been found that polymers of glycerol with a high percentage of linear oligomers are obtained if glycerol or its derivatives isopropylidene glycerol (Solketal), glycidol and glycerol carbonate are polymerized in the presence of an anionic clay material.
Clay minerals are phyllosilicates, layered or two-dimensional silicates. The basic building blocks are octahedral layers of metal or non-metal oxides and hydroxides and tetrahedral layers of polymeric Si (O, OH).sub.4. In case of the generally and widely found cationic clays, interlayer alkali or alkaline earth cations and frequently water molecules, balance the excess of negative charges of the silicate sheets, which render these clays acidic. The far less common anionic clays, however, are composed of positively charged metal oxide/hydroxide layers with anions and water located interstitially. The anionic clays are also called mixed metal hydroxides since the positively charged metal hydroxides must contain two metals in different oxidation states, usually divalent and trivalent metal oxides/hydroxides, and in the sheets these share octahedral edges. Typical examples of the anionic clay minerals are hydrotalcite (Mg.sub.6 Al.sub.2 (OH).sub.16 (CO.sub.3.sup.2-).4H.sub.2 O), tacovite (Ni.sub.6 Al.sub.2 (OH).sub.16 (CO.sub.3.sup.2-).4H.sub.2 O and pyroaurite or sjogrenite (Mg.sub.6 Fe.sub.2 (OH).sub.16 (CO.sub.3.sup.2-).4H.sub.2 O).
The structure of hydrotalcite can exhibit wide variations in the Mg.sup.2+ /Al.sup.3+ ratio, the type of anions and different divalent and trivalent cations. Anions may vary in size from small ones, such as OH.sup.- to large ones, such as CO.sub.3.sup.2-, and also fatty acid or dicarboxylic acid radicals, such as derived from lauric acid, st
REFERENCES:
patent: 3576762 (1971-04-01), Maguet-Martin et al.
patent: 3968169 (1976-07-01), Seiden et al.
patent: 4891421 (1990-01-01), Nishimura et al.
DATABASE WPI, Derwent Publications Ltds., AN 93-049562(06) & JP,A,5 000 981, Jan. 8, 1993, see abstract.
Eshuis Johan Jan W.
Laan Johannes Arie M.
Roberts Glyn
Acquah Samuel A.
Unichema Chemie B.V.
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