Abstract:
A composite material is described which is characterized by a substrate based on vegetable materials, in particular vegetable fibers, vegetable fiber raw materials or vegetable fiber semifinished products, and by a nanocomposite which is in functional contact with said substrate and is obtainable by surface modification of a) colloidal inorganic particles with b) one or more silanes of the general formula (I) Rx—Si—A4−x (I) where the radicals A are identical or different and are hydroxyl groups or groups which can be removed hydrolytically, except methoxy, the radicals R are identical or different and are groups which cannot be removed hydrolytically and x is 0, 1, 2 or 3, where x≧1 in at least 50 mol % of the silanes; under the conditions of the sol-gel process with a below-stoichiometric amount of water, based on the hydrolysable groups which are present, with formation of a nanocomposite sol, and further hydrolysis and condensation of the nanocomposite sol, if desired, before it is brought into contact with the substrate, followed by curing.
Abstract:
The present invention relates to colloidal metal oxides having blocked isocyanate groups, which are based on the reaction product ofA) blocked isocyanate group-containing silanes corresponding to formula (I) ##STR1## wherein R represents hydrogen or an organic group having 1 to 40 carbon atoms,X, Y and Z represent identical or different organic groups having 1 to 30 carbon atoms which are inert to isocyanate groups below 100.degree. C., provided that at least one of these groups is a C.sub.1 -C.sub.4 -alkoxy group,Q represents an organic group which contains at least one isocyanate group reacted with a blocking agent andn is 2, 3 or 4 withB) colloidal metal oxides selected from Al, Si, Ti, Ta, W, Hf, Zr, Sn and Y.The present invention also relates to the use of modified metal oxides, either alone or in combination with compounds containing at least two isocyanate-reactive groups, for the preparation of optionally expanded polyurethane plastics, lacquers or coating agents.
Abstract:
The present invention relates to an adhesive comprising at least one matrix material and core/shell particles comprising cores having a diameter in the range from 1 nm to 1 μm with a shell comprising oligomers and/or polymers, and to a process for the preparation thereof.
Abstract:
The present invention relates to silanes, in particular amphiphilic silanes, to processes for the preparation of the silanes, to the use thereof for the surface modification of particles, and to particles whose surface has been modified by means of the silanes.
Abstract:
The invention relates to supported metal-organic framework materials comprising a combination of metal-organic framework material (MOF) and open-pore polymer foams (polyHIPE), and to their preparation and use as gas storage material.
Abstract:
The present invention relates to binders, to processes for the preparation thereof, and to the use thereof in formulations, surface coatings, inks and plastics.
Abstract:
The present invention relates to surface-modified particles which can be dispersed in organic solvents, and to the use thereof for incorporation into polymers, paints and coatings.
Abstract:
A process for preparing a composition for producing nanostructured mouldings and layers comprises contacting an aqueous and/or alcoholic sol of a compound of an element selected from silicon sand metals of the main groups and transition groups of the Periodic Table with species possessing hydrolysable alkoxy groups and comprising at least one organically modified alkoxysilane or a precondensate derived therefrom, under conditions which lead to (further) hydrolysis of the species, and subsequent removal of the alcohol formed and any alcohol already present originally. The process is characterized in that the alcohol is removed in an amount such that the residual alcohol content of the composition is not more than 20% by weight.
Abstract:
A foundry binder is obtainable by surface modification of a) colloidal inorganic particles with b) one or more silanes of the general formula (I) Rx—Si—A4−x (I) where the radicals A are identical or different and are hydroxyl groups or groups which can be removed hydrolytically, except methoxy, the radicals R are identical or different and are groups which cannot be removed hydrolytically and x is 0, 1, 2 or 3, where x≧1 in at least 50 mol % of the silanes; under the conditions of the sol-gel process with a below-stoichiometric amount of water, based on the hydrolysable groups which are present, with formation of a nanocomposite sol, and further hydrolysis and condensation of the nanocomposite sol, if desired, before it is brought into contact with the foundry sand.
Abstract:
Disclosed is a process for providing a metallic surface with a vitreous layer which is both decorative and scratch resistant and corrosion inhibiting. Said process is characterized in that a coating composition which is obtainable by a process comprising the hydrolysis and polycondensation of one or more silanes of the general formula (I)R.sub.n SiX.sub.4-n (I)wherein the groups X, the same or different from each other, are hydrolyzable groups or hydroxyl groups, the radicals R, the same or different from each other, represent hydrogen, alkyl, alkenyl or alkynyl groups having up to 12 carbon atoms and aryl, aralkyl and alkaryl groups having 6 to 10 carbon atoms, and n is 0, 1 or 2, provided that at least one silane with n=1 or 2 is employed, or oligomers derived therefrom, in the presence ofa) nanoscaled SiO.sub.2 particles and/orb) at least one compound selected from the group consisting of the oxides and hydroxides of the alkali and alkaline earth metals;is applied onto said metallic surface and the resulting coating is thermally densified to form a vitreous layer.