Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Patent
1997-03-19
1998-07-07
Morgan, Kriellions S.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
524 48, C08K 716, C08L 302
Patent
active
057770034
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1) Field of the Invention
The invention relates to redispersible polymer powder compositions which comprise homo- or copolymers of ethylenically unsaturated monomers and cyclodextrins or cyclodextrin derivatives; processes for their preparation and their use. The invention furthermore relates to the polymer dispersions which are obtainable as intermediate products and are stabilized with cyclodextrins or cyclodextrin derivatives.
2) Background Art
Redispersible powders which can be prepared from dispersions of the most diverse polymers are gaining ever increasing importance for the most diverse uses. In general, dispersions stabilized with a protective colloid and/or emulsifier are used as the starting substances for the preparation of these powders. These dispersions are dried in a known manner and at the same time or subsequently are protected against blocking during storage by means of additives. The protective colloids used are, for example, synthetically prepared water-soluble homo- and copolymers or natural products, such as cellulose derivatives and starch derivatives. However, in spite of the addition of protective colloids, many known dispersions cannot be dried to give redispersible powders.
The preparation of redispersible polymer powders which are obtainable by drying polymer dispersions prepared by polymerization in the presence of starch and/or starch derivatives is known from EP-A 134451. Dextrins accessible by hydrolysis of starch are described as starch derivatives.
EP-A 536597 (CA-A 2079726) discusses the preparation of aqueous polymer dispersions in the presence of roasted dextrins accessible by the action of heat on starch. The Application furthermore relates to the preparation of aqueous polymer dispersions in the presence of starch degradation products of bimodal molecular weight distribution accessible by hydrolysis in an aqueous phase. It furthermore relates to the preparation of polymer powders by drying the aqueous polymer dispersions mentioned.
EP-A 408099 (U.S. Pat. No. 5147907) relates to the preparation of aqueous polymer dispersions in which the polymerization is carried out in the presence of roasted dextrins having a molecular weight of >5000. The use of low molecular weight starch degradation products is advised against.
A disadvantage of all the procedures mentioned is that if starch degradation products such as dextrins, which are obtainable by acid hydrolysis (acid dextrins) or by heat treatment (roasted dextrins), are used, a mixture of longer or shorter, branched or unbranched glucose chains is present rather than defined compounds. The molecular weight can vary over a relatively wide range and can be stated only in ranges. As a consequence of the variation, the polymerization result is not reliably reproducible when such mixtures are used; variations occur in respect of product quality of the polymer dispersions, which can also have an effect on the properties of redispersible polymer powders prepared therefrom. In spite of the addition of starch degradation products as a protective colloid, many dispersions cannot be dried to give redispersible powders. The powder properties and the use properties of products prepared in this way furthermore are subject to wide variations which are influenced on the one hand by the raw material basis used and on the other hand by the hydrolysis process.
SUMMARY OF THE INVENTION
There was therefore the object of providing re-dispersible polymer powders, the use properties of which can be adjusted reliably by using, as protective colloids, compounds which have the lowest possible molecular weight and the lowest possible range in variation in respect of their composition.
This object is achieved with polymer powders which comprise cyclodextrins or cyclodextrin derivatives.
It is known from EP-A 355685 to employ cyclo-dextrins as foam suppressants in polymer dispersions. JP-A 58168603 (Derwent Abstract AN 83-816629) describes the use of lipophilic cyclodextrin derivatives in the polymerization of two-p
REFERENCES:
patent: 3565887 (1971-02-01), Parmerter et al.
patent: 4582900 (1986-04-01), Braudt et al.
patent: 5004767 (1991-04-01), Krause et al.
patent: 5055504 (1991-10-01), Mahil et al.
patent: 5147907 (1992-09-01), Rinck et al.
patent: 5274016 (1993-12-01), Berner et al.
patent: 5480924 (1996-01-01), Vieil et al.
patent: 5492947 (1996-02-01), Wood et al.
Translation to 0134451 by Janet Thompson C10 Europe House.
Derwent Abstract (AN 83-816629) corresponds to JP-A 58168603.
Derwent Abstract (AN 30-059839) corresponds to EP -A 355685.
Figge Reiner
Haas Wolfgang
Morgan Kriellions S.
Wacker-Chemie GmbH
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