Abstract: A method for producing self-emulsifiable, aqueous polyurethane resins by a) preparing a premix of polyol component including a least one diol having a molar mass of 500 to 5,000 Dalton, at least one polyhydroxyalkane at least one anionically modifiable dihydroxyalkane-carboxylic acid and 0 to 9 parts by weight of a solvent component in desired ratios; b) reacting a polyisocyanate component the premix from stage a) to give a polyurethane preadduct, c) reacting the polyurethane preadduct from stage b) with either the premix from stage a) or with an anionically modifiable dihydroxyalkanecarboxylic acid to give a polyurethane prepolymer; d) mixing the polyurethane prepolymer from stage c) with a prepared mixture of water, a neutralizing component and an antifoam component; and thereafter or simultaneously reacting the aqueous polyurethane prepolymer from stage d) with a chain-extending component which is diluted with water.

Abstract: An aqueous highly cross-linked two-component polyurethane coating system is described with reduced hydrophilicity and improved resistance to chemicals which can be obtained by a) producing a binder component based on an aqueous solution or dispersion of low-molecular hydroxyfunctional and/or aminofunctional oligourethanes or polyurethanes and b) by subsequently reacting the binder component a) with a cross-linking component (H) in a ratio of 3:1 to 5:1, wherein water-dispersible polyisocyanates are used as the cross-linking component (H).

Abstract: Polyurethane or polyurethane polymer hybrid dispersions, with reduced hydrophilicity and methods for preparing and using them are disclosed.

Abstract: An aqueous fluoromodified polyurethane system for one- or two-component anti-graffiti and anti-soiling coatings is described which is obtainable by

Abstract: A solvent-free polyurethane-polymer hybrid dispersion having a high solids content of polymer or formulation constituents is described, which is obtainable by a) the multistage preparation of a polyurethane base dispersion and b) by the subsequent preparation of a polyurethane-polymer hybrid dispersion. This polyurethane-polymer hybrid dispersion not only is distinguished by complete freedom from solvents and high solids contents in combination with low viscosity and a technically simple preparation process but also has excellent mechanical properties and, owing to the low hydrophilicity, high water resistance.

Abstract: A description is given of a solvent-free polyurethane dispersion having a high solids content of polyurethane polymer or fillers, which is obtainable by a) allowing a relatively high molecular weight polyol component (A) (i) and, if desired, a low molecular weight polyol component (A) (ii) to react with a polyisocyanate component (B) in the presence or absence of a catalyst to give a polyurethane preadduct, then b) reacting the polyurethane preadduct from step a) with a low molecular weight and anionically modifiable polyol component (A) (iii) containing two or more hydroxyl groups and one or more carboxyl groups to give the corresponding prepolymer, c) allowing the prepolymer from step b) to react with a neutralization component (C) until the carboxyl groups have been completely or partially neutralized, subsequently or simultaneously d) dispersing the neutralized prepolymer from step c) in water which may further comprise a formulation component (F) comprising fillers, pigments, plasticizers, fibrous ma

Abstract: A polyurethane (polymer hybrid) dispersion with reduced hydrophilicity is described, which has been prepared by reacting

Abstract: A flexible and/or postformable coating system for veneered wood and further coating materials based on at least one polyurethane dispersion is described, which is obtainable by reacting

Abstract: Described is a polyurethane/polymer hybrid dispersion with high film hardness, which comprises the reaction components (A) from 3 to 25% by weight of a polyol component consisting of (i) from 2 to 20% by weight of a relatively high molecular mass polyol component, (ii) from 0.5 to 5% by weight of a low molecular mass polyol component, (iii) from 0.5 to 3% by weight of a low molecular mass and anionically modifiable polyol component, (B) from 2 to 20% by weight of a polyisocyanate component, (C) if desired, from 0 to 6% by weight of a solvent component consisting of (i) at least one polyisocyanate-inert organic solvent and/or (ii) a polyisocyanate-inert reactive diluent, (D) from 0.15 to 1.5% by weight of a neutralizing component, (E) from 0.1 to 1% by weight of a chain extender component, (F) from 5 to 40% by weight of a monomer component, (G) from 0.01 to 1.5% by weight of an initiator component, and water as the remainder.

Abstract: The use of aqueous isocyanate-free polyurethane dispersions with a solids content of ≧30 wt. % and a solvent content of ≦10 wt. % in formulations for crack sealing coating systems is disclosed. Said use may be in a) primer, floating screed, floor coatings, spray coatings and/or sealants, on, preferably, primed building surfaces, b) roof coatings or paints and c) sealing of open-cast or subterranean mines. According to the invention, the disclosed polyurethane dispersions are not just more environmentally-friendly and easier to use, but also give a partly improved product property to the corresponding crack sealing coating systems, such as, for example, mechanical properties (tensile strength, stretching under tension, tear elongation), UV resistance and colour stability.

Abstract: A method for the production of self-emulsifiable, aqueous polyurethane resins having improved characteristics is described, in which

Abstract: A self-crosslinking polyurethane polymer hybrid dispersion based on oxidatively drying polyols having a high degree of film hardness is described, which is characterized in that it contains the reaction components claimed. The advantages of the polyurethane polymer hybrid dispersion according to the invention, such as a high degree of hardness in combination with high flexibility of the tear-free films, good resistance to chemicals, high stability of the dispersions in a wide pH range, good stability in the freezing and thawing cycle and the use of economical raw materials, are achieved in a simplified synthesis pathway wityout subsequent chemical crosslinking, and simultaneously with a low content of organic solvent (≦4% by weight) and good film formation at temperatures of ≧+10° C.

Abstract: The invention relates to the use of aqueous, isocyanate-free, polyurethane dispersions with a solid content of ≧30 wt. % and a solvent content of ≦10 wt. % in sports floor coverings. The inventive polyurethane dispersions are particularly suitable for use as bonding agents for elastic coatings, spray coatings or flow coatings on elastic or rigid undersurfaces, adhesion promoters or primary coatings, fillers for sealing pores, adhesives for gluing pre-fabricated plastic coatings or for sealing sports floor coverings. The inventive polyurethane dispersions are environmentally friendly and easy to manufacture. They are also partly characterized by improved product features, e.g. mechanical properties, UV resistance and color stability, with respect to the corresponding sports floor coverings.

Abstract: The invention relates to a process for isolating pure diketene with recovery of materials of value by continuous, two-stage distillation of crude diketene at reduced pressure and with continuous reaction of the resulting distillation residue with acetic acid, pure diketene and acetic anhydride being separated off by means of the two-stage distillation. In the stabilization of the distillation residue with acetic acid, reutilizable acetic acid, which contains acetone with or without acetic anhydride, is recovered.

Abstract: A method and an apparatus for influencing a laminar-turbulent boundary layer transition on bodies in flow is indicated. The disturbances are in this case introduced into the boundary layer in an unsteady manner. The disturbances are induced by blowing-out and sucking-off and/or by oscillations of the surface and/or by sound pressure.

Abstract: The invention relates to a process for the isolation of chloroacetaldehyde which is obtained as a by-product during the synthesis of acetaldehyde from ethylene and air in an aqueous palladium/cupric chloride solution by the 2-stage process. The mixture to be worked-up to chloroacetaldehyde is taken from the acetaldehyde distillation column and transferred to a distillation and extraction system, where it is fractionally condensed. The chloroacetaldehyde-containing fraction is extracted with water and the aqueous extract is subjected to purification distillation.