Akzo N.v.

Akzona Incorporated

Enka Ag

Wolfgang Lange

Klaus Gerlach

Nikolaus Mathes

Dieter Loh

G J Boer

A microporous powder form polylactide which can take up a multiple of its own weight of active material and which can be used for the controlled release of that active material. The aforesaid microporous polylactide powder can be prepared by dissolving polylactide under warming in phthalicacid diethylester, preferably at a temperature over 150.degree. C. and then slowly cooling the clear solution. The resulting suspension is then subjected to filtering and any remain phthalicacid diethylester preferably removed by extraction. The microporous powder recovered is especially suitable for applying thereto therapeutically active substances for controlled release therefrom and is particularly suitable for utilization in veterinary and human medicine. The microporous powder in this form can be introduced into the body subcutaneously, intramuscularly and intraperitoneally.

Microporous powder form polylactides

Process and apparatus for enriching liquids with oxygen by means of a catalyst and a liquid which gives off oxygen under the effect of that catalyst. The process involves passing the oxygen-yielding liquid through a porous molding, in the pores of which the catalyst is incorporated in known manner, thereby giving off oxygen, the side of the porous molding which gives off a greater quantity of oxygen being in contact with the liquid to be enriched with oxygen. The oxygen-yielding liquid is passed through the porous molding under its own static pressure, or under the effect of the excess pressure built up in the container through the formation of oxygen. Preferred embodiments include use of 0.1 to 5% solution of hydrogen peroxide as the oxygen-yielding liquid; using manganese dioxide, Fe.sub.2 O.sub.3 or nickel oxide as the catalyst. The apparatus for carrying out the process includes a storage vessel containing the liquid which gives off oxygen under the effect of a catalyst, connecting means, and a porous molding connected thereby to the storage vessel and containing the catalyst, the molding being completely immersible in the liquid to be enriched with oxygen. Alternatively, the storage vessel and the porous molding can be dipped into the liquid to be enriched with oxygen, so that at least the entire molding is immersed.

Process and an apparatus for enriching liquids with oxygen

Polyester fibers containing an oxalate complex of the general formula

Process for the manufacture of flame-resistant and hydrophilic polyester

A composite body for long-term delivery of effective substances has a carrier for effective substances composed of a microporous polymer, and a coating composed of cellulose nitrate. The carrier can be composed of a thermoplastic polymer with a substantially isotropic microporous cellular polymer structure with a plurality of substantially spherical cells of a mean diameter between 0.5 and 100 micrometers. The cells are connected with one another by pores. The composite body serves for long-term delivery of peptides, hormones, neurotransmitters, particularly vasopressin and oxytocin.

Composite body for long-term delivery of effective substances

Microporous polylactide powders having an intrinsic isotropic structure being spherical in a shape and containing interconnecting hollow spaces or openings i.e., micropores are obtained by the steps of heating a polylactide in xylene until substantially complete solution is reached; cooling the resultant clear solution; and separating off the xylene. The microporous powder form powders can have active substances such as a medicament introduced therein i.e. unto the pores and the resultant powder can be used for controllably dispensing the medicament i.e., as a prolonged release form.

Microporous polylactide powders and a process for their preparation

Process and apparatus for enriching liquids with oxygen by means of a catalyst and a liquid which gives off oxygen under the effect of that catalyst. The process involves passing the oxygen-yielding liquid through a porous molding, in the pores of which the catalyst is incorporated in known manner, thereby giving off oxygen, the side of the porous molding which gives off a greater quantity of oxygen being in contact with the liquid to be enriched with oxygen. The oxygen-yielding liquid is passed through the porous molding under its own static pressure, or under the effect of the excess pressure built up in the container through the formation of oxygen. Preferred embodiments include use of a 0.1 to 5% solution of hydrogen peroxide as the oxygen-yielding liquid; using ruthenium oxide or hydroxide as the catalyst. The apparatus for carrying out the process includes a storage vessel containing the liquid which gives off oxygen under the effect of a catalyst, connecting means, and a porous molding connected thereby to the storage vessel and containing the catalyst, the molding being completely immersible in the liquid to be enriched with oxygen. Alternatively, the storage vessel and the porous molding can be dipped into the liquid to be enriched with oxygen, so that at least the entire molding is immersed. Preferred embodiments include the porous molding being a tube having at least one empty space extending over its entire length, one end tightly sealed and the other end tightly connected to the storage vessel; the porous molding being a hollow body having an empty space with an internal diameter of at least 0.5 mm extending over its entire length; the porous molding being of polypropylene, MgO, Al.sub.2 O.sub.3 or clay; use of a metering pump for adjusting the supply of oxygen-yielding liquid; and provision of a vent connected to the porous molding.

The invention relates to a process producing porous powdery polymer particles. A homogeneous mixture having two components minimum, one a meltable polymer, the other fluid inert to the polymer, both forming a system having a range of complete miscibility and a miscibility gap are introduced to a bed of solid-substance particles, then cooling the mixture to below solidification of the polymer and comminuting the obtained cake-like mass. The polymer is separated then from the inert fluid and solid-like substance particles.

Porose, pulverformige polymerteilchen

A new and useful hydrophilic polyester fiber and process of making same are disclosed; the fiber has a stable pore system exhibiting a moisture pickup (regain) of at least about 2 percent by weight at 40.degree. C. and a relative humidity of 92%. Our experiments indicate that the proportion of moisture regain is attributable to capillary condensation in an amount of at least 25%. The hydrophilic properties are the result of a certain pore system within the fiber which enables capilliary condensation to occur significantly. The invention describes one way to accomplish this, namely by the addition of a predetermined amount of a suitable oxalato-complex to a suitable polyester mass. Most preferably, about 10% by weight K.sub.3 Al(C.sub.2 O.sub.4).sub.3 is added to the polyester mass. The fibers are produced by extruding a suitable polyester mass containing 1 to 20 percent by weight of a suitable oxalato complex to form a filament, drawing the filament, and hydrosetting the drawn filament at a suitable temperature, generally between about 90.degree. C. and about 170.degree. C., preferably between about 120.degree. C. and about 140.degree. C., under pressure, and in the presence of liquid water. The hydrophilic polyester produced by the novel process has the favorable moisture regain and many of the favorable texture qualities of cotton, together with the quick drying qualities of conventional polyester fiber.

Process for making hydrophilic polyester fiber

A molded polymer body with very fine, discrete, solid particles composed of a metal, metal compound or a mixture of the same incorporated within the molded body in a uniform pattern of distribution, substantially free of agglomerations, as obtained by a process of first impregnating the molded body with a bath solution of a metal compound and then gassing the molded body with a gaseous precipitating agent to precipitate the metal-containing particles. The products are especially useful in catalytic membranes, e.g. as used in artificial lungs or artificial kidneys.

Production of molded polymer body with metal inclusions

Hydrophilic polyester fiber and process for making same

A molded polymer body with very fine, discrete, solid particles composed of a metal, metal compound or a mixture of the same incorporated within the molded body in a uniform pattern of distribution, substantially free of agglomeration, as obtained by a process of first impregnating the molded body with a bath solution of a metal compound and then gassing the molded body with a gaseous precipitating agent to precipitate the metal-containing particles. The products are especially useful in catalytic membranes, e.g. as used in artificial lungs or artificial kidneys.

Molded body with inclusions

Flame retardant, and under some conditions self-extinguishing synthetic polymers are made by the addition thereto of a complex salt of an alkali aluminum acid of the formula:

Growing community of inventors

Obernburg, Germany

Wolfgang Lange