摘要:
The instant invention relates to a one-step process for the production of elastomeric moldings which have a compact surface by the technique of reaction injection molding, using highly reactive systems of specific polyisocyanates, polyhydroxyl compounds and specific active aromatic polyamines. The instant invention further relates to active hydrogen containing blends useful in preparing elastomeric moldings, said blends comprising polyhydroxyl compounds, and specific active aromatic diamines. The blends herein may also contain catalyst for the reaction between hydroxyl groups and isocyanate groups.
摘要:
The present invention is directed to a process for the production of polyurethane or polyurea elastomeric molded articles according to the reaction injection molding process by reacting a polyisocyanate, a high molecular weight isocyanate reactive component and optionally a diamine chain extender, wherein the improvement is based on the use of the reaction product of a polyepoxide containing at least two epoxide groups with at least one mol of an aromatic diamine per epoxide group wherein the polyepoxide is present in an amount sufficient to provide about 0.5 to 25% by weight of the polyepoxide based on the weight of all the isocyanate reactive components. The present invention is also directed to the isocyanate reactive components for use in this process and to the molded articles produced in accordance with this process.
摘要:
This invention relates to a process for making polyurethane elastomer moldings fromA. organic polyisocyanatesB. polyhydroxyl compounds having molecular weights in the range from about 1800 to about 10,000,C. a chain extender,D. a blowing agent andE. optionally the auxiliaries and additives commonly used in making polyurethanes,The improvement wherein said chain extender (c) is a polyol mixture comprisingI. ethylene glycol andIi. at least one other polyol having a molecular weight below 1800 and wherein said polyol mixture has an average molecular weight below about 600.
摘要:
A folding device (10) includes: two cam-controlled folding knives (20, 21) that are vertically moveable relative to each other; a run-in table (60) vertically shiftable synchronously with the folding knives; and a counter-pressure line (80) having at least one pressure cylinder (82) per sliding block (84). The shafts (30, 31) and their drive systems (50, 51) are shiftable in mutually opposed vertical directions and are synchronized, e.g. electronically or via T-type gears (53, 54) having a common motor (52). At least one shaft (31) with its motor (51) is shiftable in a linear carriage (37) of a vertical linear slideway (38). The folding knives (20, 21) are rotatably supported at linear carriages (24, 25) guided on linear slideways (27, 28) and connected to cam disks (40, 41) which, synchronously with at least two eccentric disks (44) fixed to the shafts (30,31), bear on associated rocker levers (45). A measuring system (86) behind the sliding blocks (84) is adapted for travelling across the entire working width (A). A control display unit (90) continuously shows the height shifting of the folding knives (20, 21), of the run-in table (60) and of an upper shaping plate or upper table (65).
摘要:
A composite plastic molding made up of a plastic foam and having a polyurethane skin is made by heating a reactive one-component system to form a polyurethane skin and then joining the polyurethane skin to the plastic foam. The one-component system is composed of a finely divided polyisocyanate in which from 0.1 to 25 equivalent percent of the isocyanate groups have been deactivated, a polyamine and/or polyol having a molecular weight of from 400 to 8000 and optionally a chain extending agent, a catalyst and known auxiliaries and additives.
摘要:
A process for the production of optionally cellular molded articles with a smooth outer skin and improved surface characteristics by the reaction, inside a closed mold, of a mixture of one or more organic polyisocyanates, one or more compounds having molecular weights of from 400 to 12,000, which contain at least two isocyanate-reactive groups, chain-linking and/or chain-extending agents, and optionally, known auxiliary agents and additives used in polyurethane chemistry, characterized in that before the reaction, surface-improving additives comprising one or more polymers or copolymers of one or more olefinically-unsaturated monomers, which polymers or copolymers have molecular weights of from 200 to 50,000, are liquid at room temperature, soluble in the reaction mixture, and inert toward isocyanate groups and at least one metal salt of a monocarboxylic acid having at least 8 carbon atoms, are incorporated into the reaction mixture.
摘要:
The instant invention relates to a method and an apparatus for the production of a foam-forming reaction mixture or homogeneous material-forming reaction mixture from at least two liquid reactants and for the subsequent introduction thereof into a cavity, and in particular into the cavity of a mold. The reactants are introduced into a mixing zone where they are mixed together. The mixture is subsequently fed through an outlet of controlled cross-section and charged into a cavity. In order to carry out the method, an apparatus is provided which comprises a mixing chamber arranged in a housing and having inlet openings for the reactants and an outlet opening for the reaction mixture, wherein an adjustable baffle plate is arranged opposite the outlet opening axially of the outlet opening.