摘要:
A rolling bearing is used for supporting a rocking mechanism or a rotating mechanism, and a film comprising a fluorine-containing polymer having a functional group(s) under a fluidized state or a film comprising a fluorine-containing polyurethane compound under a solid state is formed on at least the track surface of the rolling bearing. Since this film does not contain ions for uniformly dispersing a thickner having non uniform particle sizes such as fluorine based grease of the prior art, breakage of the film between a rolling element and a race is not likely to occur, and wear of a rolling element race resulting from the direct contact between them due to breakage of the film can be reduced. When this film is the same kind of a film as a protective film of the surface of an information recording disk, dust generating components of the film are the same kind of components as those of the protective film, and information recording/reproduction of the information recording disk is not impeded.
摘要:
An aromatic polycarbodiimide having a structural repeating unit represented by the following formula (I): wherein R represents a hydrogen atom or an alkyl group and n is an integer of 3 to 600, which has excellent solubility and heat resistance and also has excellent adhesion, low-temperature workability and moisture resistance, is provided.
摘要:
Isocyanate-substituted isophthaloyl chlorides may be made by forming a mixture of amino-substituted isophthalic acid or a salt thereof, with phosgene and halogenated solvent in the presence of a catalyst, heating said mixture in a pressure vessel under autogenous pressure, treating the mixture to remove the solvent, and distilling the mixture to yield the isocyanate-substituted isophthaloyl chloride. The preferred catalyst is imidazole and the preferred isocyanate-substituted isophthaloyl chloride is 5-isocyanatoisophthaloyl chloride.
摘要:
Die vorliegende Erfindung betrifft reine Polyurethane, enthaltend aliphatische und/oder cycloaliphatische Diisocyanate, Macrodiole vom MG 500 bis 10000 und Kettenverlängerer vom MG 62 bis 400, erhältlich durch Umsetzung von aliphatischen und/oder cycloaliphatischen Diisocyanaten mit einem Macrodiol zu einem NCO-Gruppen aufweisenden Voraddukt, wobei man 1,5 bis 22 Mol Diisocyanat pro Mol Macrodiol einsetzt, und die Kettenverlängerung des Voraddukts mit niedermolekularen aliphatischen und/oder cycloaliphatischen Diolen vornimmt, gegebenenfalls weiteres Diisocyanat - unter Beibehaltung des o.g. NCO/OH-Verhältnisses - als Kettenverlängerer zuführt, daß man die Voradduktbildung bei 90-150 °C durchführt und die Kettenverlängerung bei Temperaturen von 120-230 °C vornimmt, mit der Maßgabe, daß man die genannten Reaktionsbedingungen mindestens so lange aufrecht erhält, bis eine Schmelzviskosität von mindestens 2500 mPas, gemessen bei 120 °C, erreicht ist und anschließend gegebenenfalls bei erhöhter Temperatur von bis zu 240 °C die Polyaddition zu einem beliebigen Zeitpunkt zu Ende führt. Die Polyurethane finden vorzugsweise Anwendung in der Medizintechnik.
摘要:
Elastomeric or flexible surgical adhesives, arising [A] NCO-tested hydrophilic urethane prepolymer derived from fluorine-containing polyisocyanate and hydrophilic polyether polyol of higher oxyethylene content, or combination of [A] with [B] unsaturated cyano compound containing cyano group attached to a carbon atom constituting the polyerizable double bond, are of lower toxicity and used with safety for bonding of tissues, with rapid cure rate and sufficient bonding power.
摘要:
This invention relates to urethane linked hydroxy aromatic amines and to a process for producing such urethane linked hydroxy aromatic amines. The compositions are formed by initially reacting one equivalent aromatic diisocyanate with one equivalent of an alkylene polyol under conditions such that only one of the isocyanate groups reacts with one hydroxyl group of the polyol. Conditions are controlled such that only the urethane linked hydroxy aromatic isocyanate is formed. Then, the resulting urethane linked hydroxy aromatic isocyanate is hydrolyzed to form the amine.