摘要:
Dispersion comprising functionalized metal oxide particles, polymerizable compounds and if appropriate a solvent and their use for stabilizing polymers.
摘要:
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, c) blowing agents, wherein b) comprise b1) from 70 to 10 parts by weight of at least one polyether alcohol having polyoxypropylene units, a nominal functionality of from 3 to 6 and a hydroxyl number of 100 to 300 mg KOH/g, b2) from 10 to 70 parts by weight of at least one polyetherol having polyoxypropylene units, a nominal functionality of 2 and a hydroxyl number of 50 to 350 mg KOH/g, b3) from 10 to 30 parts by weight of at least one polyether alcohol having ethylene oxide units, a nominal functionality of from 2 to 3 and a hydroxyl number of 50 to 550 mg KOH/g, b4) from 0 to 20 parts by weight of at least one graft polyetherol having a nominal functionality of from 2 to 3 and a hydroxyl number of 20 to 40 mg KOH/g.
摘要:
A method for producing a polyol, the method including:(a) reacting at least one selected from the group consisting of an unsaturated natural fat, an unsaturated natural fatty acid, and a fatty acid ester with dinitrogen monoxide, to obtain a first intermediate;(b) reacting the first intermediate with a hydrogenation reagent, to obtain a second intermediate;(c) reacting the second intermediate with at least one alkylene oxide, to obtain a polyol.
摘要:
The invention relates to stable silicon dioxide dispersions and also their use for producing polyurethanes. The silicon dioxide dispersions are largely or preferably completely free of water and comprise silicon dioxide particles having an average diameter of 1-150 nm and at least one chain extender. The silicon dioxide particles can be modified by means of a silane (S) which comprises groups which are reactive toward isocyanates. Furthermore, a polyol, in particular a polyesterol and/or an isocyanate-comprising compound can be comprised in the silicon dioxide dispersions.
摘要:
Process for producing silica-comprising dispersions comprising a polyetherol or a polyether amine, which comprises the steps of (i) admixing an aqueous silica sol (K) having an average particle diameter of from 1 to 150 nm and a silica content, calculated as SiO2, of from 1 to 60% by weight and a pH of from 1 to 6 with at least one polyetherol (b1) and/or polyether amine (b2) based on ethylene oxide and/or propylene oxide and having an average OH or amine functionality of from 2 to 6 and a number average molecular weight of from 62 to 6000 g/mol, (ii) distilling off at least part of the water, (iii) admixing the dispersion with at least one compound (S) having at least one at least monoalkoxylated silyl group and at least one alkyl, cycloalkyl or aryl substituent, where this substituent may have groups which are reactive toward an alcohol, an amine or an isocyanate in an amount of from 0.1 to 20 μmol of (S) per m2 of surface area of (K), where steps (i) and (iii) can be carried out simultaneously or in succession in any order, (iv) optionally adjusting the pH of the silica-comprising dispersions obtained to a value of from 7 to 12 by adding a basic compound, where step (iv) can also be carried out between steps (ii) and (iii).
摘要:
Improved metal oxide nanoparticles, in particular zinc oxides, are modified with silanes. The particles obtained in this way are suitable for an improved UV protection of polymers.
摘要:
In a process for preparing a polyether alcohol d1) by reaction of a) at least one compound having at least three hydrogen atoms reactive with alkylene oxides and a molecular weight Mn of not more than 600 g/mol with b) an alkylene oxide by using c) a catalyst, said reaction is carried out in the presence of a polyether alcohol d) having a hydroxyl number of 100-800 mg KOH/g and a functionality of 1.5 to 8.
摘要:
A unique combination of a hydrophilic polyol (A) and a hydrophobic polyol (B) having a terminal ethylene oxide cap are used in a resin composition and a polyurethane system, and are used to form a polyurethane article, such as a polyurethane foam. The hydrophilic polyol (A) is ethylene oxide (EO) rich and the hydrophobic polyol (B) is propylene oxide (PO) rich. The hydrophilic polyol (A) and the hydrophobic polyol (B) are present in the resin composition and the polyurethane system in a weight ratio (A:B) of from 1.5:1 to 20:1. The polyurethane article exhibits excellent comfort for use in vehicle applications, such as automotive and motorcycle seating, due to reduced resonance frequency and reduced peak vibration transmissivity relative to previous polyurethane articles.
摘要:
The invention relates to composite components with the following layered structure: (i) between 0.05 mm and 2 mm metal; (ii) between 0.1 mm and 2 mm polyisocyanate-polyaddition products, which are present in a support; (iii) between 0.05 mm and 2 mm metal.
摘要:
A method for the preparation of a fexible polymeric foam by reacting a polyisocyanate component comprising an isocyanate-containing prepolymer having an NCO-content of from 2 to 15% by weight, with an isocyanate-reactive component comprising water and a polyoxyalkylene polyol having a high ethylene oxide and primary hydroxyl group content.