Ceskoslovenska Akademie Ved

Ceskoslovenska Akademie Ved of Prague

Slavko Hudecek

Ivana Gavrilova

Pavel Cefelin

Jan Kolarik

Jaroslav Hnidek

Viktor Heidingsfeld

Frantisek Juracka

Jiri Zelinger

Ivana Hudeckova

Miroslav Beran

Jaroslava Otoupalova

Iva Hudeckova

This invention relates to terpolymers which are capable of forming hydrogels having very good compatibility with living tissues and may be used as substitutes for damaged tissues, as in the form of implants and various prostheses. The terpolymers are comprised of an oligourethane having an average molecular weight from 1200 to 3000, 2-hydroxyethyl(meth)acrylate or 2-hydroxypropyl(meth)acrylate, and N-vinylpyrrolidone.

Terpolymers having the character of hydrogels

Graft copolymers are formed having a backbone formed by monomeric units, selected from the group of vinyl monomers comprising acrylates, methacrylates, acrylamide, styrene and N-vinyl-2-phyrrolidone, and side branches formed by 10-80 wt. % of oligourethanes based on aliphatic, aromatic and alkylaromatic diisocyanates and low-molecular-weight diols with 2-4 carbon atoms in the molecule. The graft copolymers are prepared in two steps: the first step consists in the synthesis of oligourethane with the terminal unsaturated group; the second step is the radical copolymerization of this oligourethane with the above vinyl monomers.

Graft copolymers and the method of their preparation

An unfoamed permeable material, which absorbs and desorbs moisture satisfactorily and which is suitable for making thin-walled articles having a maximum thickness of 3 mm, is based on plastic and/or rubber mixtures containing macromolecular hydrophilic fillers. The hydrophilic fillers are synthetic, water insoluble, cross-linked macromolecular materials containing pendent polar groups, which are able to bind water reversibly, e.g. hydroxy, amine, amide, carboxylic and sulfonic groups in H.sup.+, Na.sup.+, K.sup.+, Li.sup.+, Ca.sup.++, or Ba.sup.++ form, or quaternary ammonium groups in CH.sup.-, Cl.sup.- or HSO.sub.4.sup.- form.

Method for producing thin-walled articles from plastic or rubber

A new method for preparation of hydrophilic fillers has been found, based on high-molecular weight compounds insoluble in water, obtained by the copolymerization of unsaturated monomers, soluble and insoluble in water, either in the form of an aqueous emulsion containing 10-70% by wt. of fillers, or in the dry powdered form having the required particle size, which in the final application are able to sorb reversibly water vapor, and are particularly suited for producing synthetic leather and similar materials.

Method for producing hydrophilic fillers for plastics and rubbers

An unfoamed permeable material, which absorbs and desorbs moisture satisfactorily and which is suitable for making thin-walled articles having a maximum thickness of 3 mm, is based on plastic and/or rubber mixtures containing macromolecular hydrophilic fillers. The hydrophilic fillers are synthetic, water insoluble, cross-linked macromolecular materials containing pendent polar groups, which are able to bind water reversibly, e.g. hydroxy, amine, amide, carboxylic and sulfonic groups in H.sup.+, Na.sup.+, K.sup.+, Li.sup.+, Ca.sup.++, or Ba.sup.++ form, or quaternary ammonium groups in OH.sup.-, Cl.sup.- or HSO.sub.4.sup.- form.

A mixture of monomers, at least one of which contains 1 or 2 --COOH groups and the other one of which contains more than 1 vinyl group in the molecule, is polymerized by means of radical polymerization in the medium of a plasticizer or a mixture of plasticizers having saturated higher fatty acids or/and unsaturated higher fatty acids (either plain or halogenated) and/or higher alcohols. The product is transferred into the Na, K or NH.sub.3 form, the content of plasticizer is reduced to 20 - 70 wt. % (e.g. by centrifugation) or water is removed (e.g. azeotropic or vacuum distillation). The product is suitable, above all, in manufacturing of hygienic artificial leathers.

Method for producing the hydrophilic filler for plastics

There is disclosed a process for producing carboxyl-containing hydrophilic polymeric fillers comprising polymerizing at least one carboxyl-containing monomer with a cross-linking monomer in an oxygen bearing organic solvent for the monomers and in the presence of a free radical catalyst to form a polymeric precipitate and treating the thus formed polymeric precipitate with a solution containing sodium, potassium or ammonium ions thereby transforming the same into the corresponding polymeric salt, said solvent being a non-solvent for the polymer.

Powdery hydrophilic fillers

A method for producing emulsions, concentrated dispersions and pastes based on plasticizers and hydrophilic fillers consists in polymerization of a mixture of monomers, at least one of which contains one or two carboxylic groups, alternatively in a form of anhydride, and the other contains more than one vinyl group in its molecule, by common free-radical initiators in a medium of a plasticizers or a mixture of plasticizers with an admixture of saturated or unsaturated higher fatty acids, either substituted by halogen or unsubstituted, and/or higher alcohols. The resulting polymer of the maximum particle size 100 .mu.m is transformed into the Na, K, or NH.sub.4 form. The emulsion, concentrated dispersion or paste is applied without further operations in processing of plastics, especially in production of plastic and synthetic leathers.

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Prague, Czechia

Slavko Hudecek