摘要:
The invention relates to a process for producing viscoelastic flexible polyurethane foams by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reactive toward isocyanate groups, wherein a mixture of bi) from 25 to 70% by weight, based on the weight of the components bi), bii), biii) and biv), of a hydroxyl-comprising natural oil or fat or a reaction product of a hydroxyl-comprising natural oil or fat with alkylene oxides, bii) from 3 to 30% by weight, based on the weight of the components bi), bii), biii) and biv), of at least one polyether alcohol which has a hydroxyl number of from 100 to 800 mg KOH/g and a functionality of from 3 to 5 and is selected from the group consisting of polyether alcohols prepared by addition of alkylene oxides onto an amine, biii) 20-50% by weight, based on the weight of the components bi), bii), biii) and biv), of at least one polyether alcohol which has a hydroxyl number of from 10 to 80 mg KOH/g and a functionality of from 2 to 5 and can be prepared by addition of ethylene oxide and propylene oxide onto H-functional starter substances, where the proportion of ethylene oxide is 5-25% by weight, based on the weight of the polyether alcohol, and at least part of the ethylene oxide is added on at the end of the polyether chain, biv) >0-8% by weight, based on the weight of the components bi), bii), biii) and biv), of at least one polyether alcohol having a functionality of 2-4, a hydroxyl number of 15-60 mg KOH/g and a content of ethylene oxide of >50% by weight, based on the weight of the polyether alcohol, as compounds having at least two hydrogen atoms which are reactive toward isocyanate groups.
摘要:
Disclosed is an aqueous plating bath suitable for obtaining electrodeposits of palladium and its alloys. The bath is substantially free of cyanide, nitrate and nitrite, and comprises sulfite ion, palladium in the form of a tetra-coordinated complex with palladium in the +2 oxidation state, an atomic ratio of halide to palladium not in excess of 10, and exhibits a pH of from 7 to 12.
摘要:
Invention relates to a process for producing viscoelastic flexible polyurethane foams by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reactive toward isocyanate groups, wherein as b) a mixture of bi) from 25 to 70% by weight of a hydroxyl-comprising natural oil or fat or a reaction product of a hydroxyl-comprising natural oil or fat with alkylene oxides, bii) from 3 to 30% by weight of at least one polyether having a hydroxyl number of from 100 to 800 mg KOH/g and a functionality of 3-5 selected from the group consisting of polyether prepared by addition of alkylene oxides onto an amine, biii) 20-50% by weight of at least one polyether alcohol having a hydroxyl number of from 10 to 80 mg KOH/g and a functionality of 2-5, where the proportion of ethylene oxide is 5-25% by weight, based on the weight of the polyether alcohol, and at least part of the ethylene oxide is added on at the end of the polyether chain, biv) >0-8% by weight of at least one polyether alcohol having a functionality of 2-4, a hydroxyl number of 15-60 mg KOH/g and a content of ethylene oxide of >50% by weight of the polyether alcohol is used.
摘要:
A process for producing high resilience flexible polyurethane foams. The process includes forming a mixture of (a) isocyanate prepolymer, (b) polymeric compounds having isocyanate-reactive groups, (c) castor oil, (d) optionally chain-extending and/or crosslinking agents, (e) catalysts, (f) blowing agents, and optionally (g) additives, and reacting the mixture to form the flexible polyurethane foam. More than 5 wt % of (c) is used, based on the total weight of components (b) to (g), and (a) is obtained by mixing diphenylmethane diisocyanate (a1) and polyol 1 (a2) and also optionally further polyols, chain extenders and/or crosslinkers, where (a2) includes a polyalkylene oxide polyol having a hydroxyl number of 30 to 60, an average functionality of 2.3 to 3.2 and a propylene oxide fraction, based on the alkylene oxide content, of 70 to 100 wt %. A polyurethane foam obtained by the process, and the use of such a foam as an auto seat.
摘要:
Improved guiding and positioning device for the block and hook of a derrick installed on board a ship, enabling dual speed boring, which, as an assembly formed by the block and the hook, is connected to a carriage sliding on two rails parallel to the axis of the well by two indentical mechanisms ensuring horizontal linear movement of the block and the hook.
摘要:
A process for producing high resilience flexible polyurethane foams. The process includes forming a mixture of (a) isocyanate prepolymer, (b) polymeric compounds having isocyanate-reactive groups, (c) castor oil, (d) optionally chain-extending and/or crosslinking agents, (e) catalysts, (f) blowing agents, and optionally (g) additives, and reacting the mixture to form the flexible polyurethane foam. More than 5 wt % of (c) is used, based on the total weight of components (b) to (g), and (a) is obtained by mixing diphenylmethane diisocyanate (a1) and polyol 1 (a2) and also optionally further polyols, chain extenders and/or crosslinkers, where (a2) includes a polyalkylene oxide polyol having a hydroxyl number of 30 to 60, an average functionality of 2.3 to 3.2 and a propylene oxide fraction, based on the alkylene oxide content, of 70 to 100 wt %. A polyurethane foam obtained by the process, and the use of such a foam as an auto seat.
摘要:
A tool clamping system for clamping an insert tool in a machine tool having a housing, in particular an ultrasound-operated machine tool, the insert tool being capable of being placed into a tool mount of the machine tool and clamped there. The tool mount has a clamping element having an operating area that works together with a housing operating area of the housing at least for the clamping of the insert tool, and that, in the operating state of the insert tool, is separated from the housing operating area by a gap.
摘要:
The closing method comprises the installing, on the inside rim of the barrel, of a seal having multiple beads and, after filling, the applying of a first hollow lid driven into the barrel down to the level of the seal, then the installing of a conventional flat lid in overlying fashion. The seal can comprise two beads and may assume a U-shape. Application is possible to the transporting of any particularly toxical or radioactive substances.