摘要:
The present invention relates to a process for recovering and recycling the organic binder components accumulating during the spraying of a solvent-containing, two-component polyurethane coating or a solvent-containing, moisture-curing one-component polyurethane coating byi) forming a coatings slurry containing the organic binder components, water and a coagulating agent,ii) mixing the coatings slurry, optionally after removing a portion of the water, with an organic solvent which is inert towards isocyanate groups,iii) reacting the free isocyanate groups present in the mixture obtained in step (ii) with a compound containing one isocyanate-reactive group which is more reactive with isocyanate groups than both water and the isocyanate-reactive component of the two-component polyurethane coating, if present, andiv) removing any remaining water and insoluble components from the organic phase accumulating in step (iii) and recovering the organic phase containing the organic binder components.
摘要:
The present invention relates to a process for recovering and recycling the organic binder components accumulating as overspray during the spraying of a solvent-containing, two-component polyurethane lacquer or a solvent-containing, moisture-curing, one-component polyurethane lacquer byi) washing the overspray out of the exhaust air of a coating plant with the aid of an aqueous medium which a) contains in dissolved or dispersed form compounds that exhibit greater reactivity towards isocyanate groups than either water or the isocyanate-reactive groups present in two-component polyurethane lacquers, and b) may contain emulsifiers,ii) isolating the chemically modified overspray formed in step (i) in the form of lacquer sludge by treatment with coagulating agents, which may be present in the aqueous medium,iii) mixing the lacquer sludge, containing fully reacted lacquer constituents, coagulating agents and water, optionally after a portion of the water is removed, with an organic solvent andiv) separating the organic phase accumulating in step iii) from the aqueous phase and insoluble-constituents which may be present and recovering the solution of modified organic binder components dissolved in the organic phase.
摘要:
An aqueous binder composition having a reduced tendency to yellow containingA) 20 to 95 wt-% of a water-dilutable organic polyol component that is present in the form of an aqueous solution or dispersion, contains one or more polymer-modified polyester resins which contain carboxylate groups and hydroxyl groups and has been prepared by the polymerization of olefinically unsaturated monomers in the presence of an unsaturated polyester resin that is copolymerized with the monomers andB) 5 to 80 wt-% of at least one heat-activatable cross-linking resin,wherein the percentages are based on the solids contents of components A) and B) and add up to 100%; and their use in heat-curable coating compositions.
摘要:
The present invention relates to a process for the production of oxidatively crosslinkable, water-dilutable binders bya) forming a copolymer having intramolecular carboxylic anhydride groups by copolymerizing anhydride-functional compounds, other olefinically unsaturated monomers and 5 to 50% by weight, based on the weight of the olefinically unsaturated monomers used for the production of the copolymers a), of monomers which cannot be homopolymerized under the reaction conditions,b) subsequently reacting by ring-opening esterification at least 50% of the anhydride groups present in the copolymer with one or more unsaturated monohydric alcohols,c) reacting by ring-opening esterification up to 50% of the anhydride groups with monohydric saturated alcohols having a molecular weight of 32 to 200 either before, during or after step b),d) optionally reacting 1 to 70% of the carboxyl groups formed in steps b) and c) with organic epoxide compounds ande) neutralizing at least a portion of the carboxyl groups formed in steps b) and c).The present invention also relates to the binders obtained by this process and to their use in water-dilutable lacquers and coating compositions.
摘要:
The present invention concerns a process for the production of cement clinker in rotary kilns with substitution of primary raw materials and fuels by use of residual materials containing minerals and combustible parts with moisture contents of up to about 65% without predrying. The process makes possible a material and/or thermal utilisation of residual materials in the case of saving of the clay and fuel sources and relief of dumping with simultaneous lowering of the emissions, above all NO.sub.x, in the cement rotary kiln.
摘要:
A coating composition in which the binding agent is a two-component system containing a) a polyisocyanate component and b) an isocyanate-reactive component and contains b1) specific ester group-containing secondary polyamines, b2) specific moisture-activatable blocked polyamines and b3) optionally other known compounds containing isocyanate-reactive groups, and a process for preparing coated substrates from this coating composition.
摘要:
A method and apparatus for producing histological sections by means of a microtome are suggested. A histological section of predefined thickness is produced with a microtome from a block comprising a tissue sample. A carrier material is applied with an application apparatus onto the block prior to before production of the histological section. To ensure that the histological sections do not roll up, and to enable improved downline processing of the histological sections as compared with a carrier material embodied in the form of an endless strip and that the carrier material is cut out prior to application to a size and/or a shape that corresponds substantially to the cross-sectional area of the block; and that the cut-out carrier material is then applied onto the block. The suggested apparatus is designed to apply the carrier material onto a histological section to be prepared by a microtome.
摘要:
A crank drive system (10) of a shaft (11) of a microtome (1) encompasses a first and a second shaft (11, 12). The first shaft (11) is rotatable with a crank (13) and comprises a first transfer gear (14). The second shaft (12) comprises a second transfer gear (15). A rotation of the first shaft (11) is transferable from the first transfer gear (14) to the second transfer gear (15) to cause the second shaft (12) to rotate. To make possible, with a microtome (1), an advance or a lowering of the specimen (2) in two respective oppositely directed rotation directions with the same crank drive system (10), the crank drive system (10) is characterized in that a third transfer gear (16) is provided. The first transfer gear (14) is selectably engageable with the second transfer gear (15) or with the third transfer gear (16) so that as a result, while the rotation direction of the second shaft (12) is maintained, the rotation direction of the first shaft (11) is reversible.
摘要:
A method of purifying water in a nuclear installation includes an ion exchange mechanism in which the water is purified with an ion exchanger. Before being guided over the ion exchanger, the water is brought into contact with a catalyst in order to decompose hydrogen peroxide that is present in the water.
摘要:
A method of purifying water in a nuclear installation includes an ion exchange mechanism in which the water is purified with an ion exchanger. Before being guided over the ion exchanger, the water is brought into contact with a catalyst in order to decompose hydrogen peroxide that is present in the water.