摘要:
A method for the preparation of a storage stable organic polyisocyanate having allophanate linkages prepared by reacting a urethane containing organic polyisocyanate with a reactive hydroxyl compound in the presence of a liquid organic titanium oxide, or zirconium oxide, or hafnium oxide catalyst that is fully miscible in the reactive hydroxyl compound is disclosed. After completion of the allophanate reaction, the catalyst is deactivated by the use of a strong inorganic acid, organic acid, organic chloroformate or acid chloride.
摘要:
A method for the production of polyurethane products using very low unsaturation polyether polyols prepared in the presence of aluminum phosphonate catalysts is disclosed. Reaction products of the process include various polyurethane products including foams, coatings, adhesives, sealants and elastomers. The aluminum phosphonate catalyst preferably has a general structure of RPO-(OAlR′R″)2, wherein O represents oxygen, P represents pentavalent phosphorous, Al represents aluminum, R comprises a hydrogen, an alkyl group, or an aryl group, and R′ and R″ independently comprise a halide, an alkyl group, an alkoxy group, an aryl group, or an aryloxy group.
摘要:
The invention relates to polycondensation resins which are prepared by polycondensation of compounds having a low molecular weight and separation of small molecules in the presence of at least one hetergeneous catalyst. The invention also relates to polyaddition resins which are prepared by polyaddition in the presence of at least one heterogeneous catalyst. The invention further relates to the use of said polycondensation resins and polyaddition resins for the preparation of moulded parts, adhesives and coating materials.
摘要:
Use of Titanium complex in a polyisocyanate composition comprising a titanium complex consisting of titanium and an acetoacetate ester in which the molar ratio of Ti to acetoacetate ester is in the range 1:2 and 1:8 and said acetoacetate ester is an ester of alcohol containing 1 to 4 carbon atoms for accelerating the binding of lignocellulosic materials.
摘要:
A process for preparing an urethane compound for medical instruments, characterized by reacting a hydroxyl compound (A) with an isocyanate compound (B) in the absence of a catalyst or in the presence of a reaction catalyst other than an organic tin compound to give an urethane compound (I). According to the process, the urethane compound showing high safety can be easily prepared, in particular, while molecular weight of the compound is controlled.
摘要:
A process for preparing an ocular lens with a urethane compound comprising the steps of a) preparing a urethane compound by reacting at least one hydroxyl compound and at least one isocyanate compound in the presence of an organic iron compound, b) removing the organic iron compound from the urethane compound obtained in the step a) c) mixing the urethane compound obtained in the step b) with at least one compound selected from the group consisting of another copolymerizable compound, a crosslinking agent, a UV absorbent, a dye, a polymerization initiator, a photosensitizer, and an organic solvent to obtain a mixture, and d) curing the mixture obtained in the step c) to prepare a lens.
摘要:
A cleaning blade for use in an electrophotographic apparatus, which rubs and eliminates residual toners. The cleaning blade is made up of polyrethane resin sheet controls chipping of a top end of the cleaning blade and reduces an abrasion of a photosensitive drum. The cleaning blade is prepared by mixing and hardening at least a prepolymer, which is obtained from butylene adipate polyester polyol, hexylene adipate polyester polyol and polyisocyanate, and a hardening agent including a low molecular weight polyol and potassium acetate so that a mol ration (&agr; value) of hydroxyl group to isocyanate group becomes not less than 0.7 and not more than 0.9.
摘要:
The invention concerns a (cyclo)trimerisation method for isocyanates having at least two isocyanate functions, characterised in that it comprises: a) reacting initial isocyanate monomers having at least two isocyanate functions, optionally in the presence of other monomers reactive with the isocyanate monomers having at least two isocyanate functions at a temperature of at least 20° C., advantageously at least 50° C., and lower than 200° C., advantageously lower than 150° C., in the presence of a compound comprising at least one rare earth alcoholate function; b) stopping the reaction by inactivating the catalyst or its derivative forms in the reaction medium at a transformation rate of at least 2.5% and at most 90% of the initial isocyanate functions; and optionally c) distilling the reaction medium to eliminate the unreacted monomers.
摘要:
A process for preparing an urethane compound for medical instruments, characterized by reacting a hydroxyl compound (A) with an isocyanate compound (B) in the absence of a catalyst or in the presence of a reaction catalyst other than an organic tin compound to give an urethane compound (I). According to the process, the urethane compound showing high safety can be easily prepared, in particular, while molecular weight of the compound is controlled.
摘要:
A self-emulsifiable polyisocyanate with high functionality, having the average number of functional groups in 4.3 or more and a viscosity of 8,000 mPa·s (at 25° C.) or less, which is obtained by subjecting a modified polyisocyanate containing allophanate bonds and a poly(oxyalkylene)glycol monoalkyl ether (e) having oxyethylene bonds in a total amount of 30 mole % or more in its molecule to a urethanization reaction, said modified polyisocyanate being obtained by reacting a polyol (a) having the average number of functional groups in an amount of 2 or more with an organic polyisocyanate (b) in the presence of an allophanate-forming catalyst (c) comprising a zirconium carboxylate; and a process for producing the same.