摘要:
A process for preparing a polyisocyanurate polyurethane material, which process comprises reacting a polyisocyanate and an isocyanate-reactive composition, wherein the reaction is conducted at an isocyanate index of 150 to 5000 and in the presence of a trimerisation catalyst, wherein the polyisocyanate comprises a) 80- 100% by weight of diphenylmethane diisocyanate comprising at least 40%, preferably at least 60% and most preferably at least 85% by weight of 4,4'- diphenylmethane diisocyanate and/or a variant of said diphenylmethane diisocyanate which variant is liquid at 25°C and has an NCO value of at least 20% by weight (polyisocyanate a), and b) 20-0% by weight of another polyisocyanate (polyisocyanate b), the amount of polyisocyanate a) and polyisocyanate b) being calculated on the total amount of this polyisocyanate a) and polyisocyanate b), and wherein the isocyanate-reactive composition comprises a) 80-100% by weight of a polyether polyol having an average nominal functionality of 2-6, an average equivalent weight of 1100-5000 and an oxyethylene (EO) content of 50-90% by weight and b) 20-0% by weight of one or more other isocyanate-reactive compounds, the amount of polyo l a) and isocyanate-reactive compound b) being calculated on the total amount of this polyol a) and compound b) and wherein the hardblock content is at most 49%.
摘要:
A process for preparing a polyurethane elastomer having an apparent overall density of more than 150 kg/m3 comprising reacting a polyisocyanate and an isocyanate-reactive composition, optionally in the presence of water, wherein the reaction is conducted at an isocyanate index of 85 to 120, the polyisocyanate consists ofa) 80-100 % by weight of a diphenylmethane diisocyanate comprising at least 40 % by weight of 4,4'-diphenylmethane diisocyanate and/or a derivative of said diphenylmethane diisocyanate which derivative is liquid at 25 °C and has an NCO value of at least 20% by weight, and 20-0 % by weight of another polyisocyanate, and wherein the isocyanate-reactive composition consists of a) 80-100 % by weight of a polyether polyol having an average nominal functionality of 2-8, an average equivalent weight of 750-5000, an average molecular weight of 2000-12000, an oxyethylene content of 60-90 % by weight and a primary hydroxyl content of 70-100 % calculated on the total number of primary and secondary hydroxyl groups in the polyol, b) an isocyanate-reactive chain extender in an amount such that the hard block ratio is less than 0.50 and c) 20-0 % by weight of one or more other isocyanate-reactive compounds excluding water, the amount of polyol a) and isocyanate-reactive compound c) being calculated on the total amount of this polyol a) and compound c).
摘要:
Process for making a polyisocyanurate composite which process comprises combining a polyisocyanate, a polyether polyol and a trimerization catalyst with a to-be-bonded material to form a reactive composite, and allowing in a next step this reactive composite to react at elevated temperature, wherein the amount of the reactive binder composition is 1 - 60 % by weight and the amount of the to-be-bonded material is 40 - 99 % by weight, both calculated on the amount of the reactive binder composition plus the amount of th e to-be-bonded material, wherein the amount of the polyisocyanate and the polyol is such that the index is 150 - 10000, characterized in that the polyol is a polyol having an average equivalent weight of 100 - 2500 and an oxyethylene content of at least 50 % by weight. The reactive composite is claimed as well together with composites obtained from this process and from these reactive composites.
摘要:
A process for preparing a polyisocyanurate polyurethane material, which process comprises reacting a polyisocyanate and an isocyanate-reactive composition, wherein the reaction is conducted at an isocyanate index of 150 to 5000 and in the presence of a trimerisation catalyst, wherein the polyisocyanate comprises a) 80- 100% by weight of diphenylmethane diisocyanate comprising at least 40%, preferably at least 60% and most preferably at least 85% by weight of 4,4'- diphenylmethane diisocyanate and/or a variant of said diphenylmethane diisocyanate which variant is liquid at 25°C and has an NCO value of at least 20% by weight (polyisocyanate a), and b) 20-0% by weight of another polyisocyanate (polyisocyanate b), the amount of polyisocyanate a) and polyisocyanate b) being calculated on the total amount of this polyisocyanate a) and polyisocyanate b), and wherein the isocyanate-reactive composition comprises a) 80-100% by weight of a polyether polyol having an average nominal functionality of 2-6, an average equivalent weight of 1100-5000 and an oxyethylene (EO) content of 50-90% by weight and b) 20-0% by weight of one or more other isocyanate-reactive compounds, the amount of polyo l a) and isocyanate-reactive compound b) being calculated on the total amount of this polyol a) and compound b) and wherein the hardblock content is at most 49%.
摘要:
A process for preparing a polyurethane material having no glass transition temperature below 25°C, which process comprises reacting a polyisocyanate and an isocyanate-reactive composition, optionally in the presence of water in an amount of less than 5 % by weight on the below isocyanate-reactive composition, wherein the reaction is conducted at an isocyanate index of 80 to 140, the polyisocyanate consists of a) 80-100 % by weight of diphenylmethane diisocyanate comprising at least 40 %, preferably at least 60 % and most preferably at least 85% by weight of 4,4'-diphenylmethane diisocyanate and/or a variant of said diphenylmethane diisocyanate which variant is liquid at 25 °C and has an NCO value of at least 20% by weight (polyisocyanate a), and b) 20-0% by weight of another polyisocyanate (polyisocyanate b), and wherein the isocyanate-reactive composition consists of a) 80-100% by weight of a polyether polyol having an average nominal functionality of 3-8, an average equivalent weight of 200-2000, an average molecular weight of 600-8000, an oxyethylene (EO) content of 50-100 % and preferably of 75-100 % by weight and a primary hydroxyl content of 70-100 % calculated on the number of primary and secondary hydroxyl groups in the polyol, b) an isocyanate-reactive chain extender and/or cross linker in an amount such that the hard block ratio is 0.60 or more and preferably at least 0.65 and c) 20-0 % by weight of one or more other isocyanate-reactive compounds excluding water, the amount of polyol a) and isocyanate-reactive compound c) being calculated on the total amount of this polyol a) and compound c).