摘要:
The present invention relates to a process for the preparation of alkoxylation products of organic carboxylic acids containing alcoholic hydroxyl groups by the reaction of any organic compounds containing at least one carboxyl group with alkylene oxides in an alkoxylation reaction in the presence of catalysts, characterized in that the catalysts used are phase transfer catalysts selected from the group consisting of(a) tetraalkylammonium or tetraalkylphosphonium halides in which the sum of carbon atoms of the alkyl groups is at least 8,(b) basic alkali metal compounds converted into complexes with crown ethers and(c) complexes of (i) basic alkali metal compounds and (ii) acyclic organic compounds containing at least 5 alkylene oxide units of the formula --R--O-- (R=C.sub.1 -C.sub.4 -alkylene) in the form of one or more polyether chains having at least 3 alkylene oxide units, said compounds having a molecular weight of at least 238 and containing a total of at least 40% by weight of alkylene oxide units of the type indicated in polyether chains having at least 3 alkylene oxide units.The present invention also relates to the use of these alkoxylation products for the production of polyurethanes by reaction with organic polyisocyanates.
摘要:
Material which hardens on access of moisture, for the production of support dressings in human medicine or veterinary medicine, which is based on a flexible carrier material impregnated and/or coated with an agent including isocyanate groups, wherein the agent contains an addition product of a sulphonyl isocyanate with a tertiary amine and/or a compound with a tin(II) or tin (IV) carboxylate structure.
摘要:
Impregnating agents are provided consisting essentially of(a) an NCO-prepolymer or NCO-semi-prepolymer which is curable by atmospheric moisture, with an NCO content of 2 to 25% by weight, based on(a1) an organic polyisocyanate and(a2) a compound with at least 2 alcohol hydroxyl groups,(b) a solvent which is inert with respect to isocyanate groups in which the (a1) organic polyisocyanate is a polyisocyanate with exclusively aliphatically or cycloaliphatically bound isocyanate groups and the (a2) polyhydroxyl compound is a polysiloxane of the molecular weight range of 300 to 5000 which has at least 2 alcoholically bound hydroxyl groups.A method of impregnating mineral substrates with such impregnating agents is also provided.
摘要:
A stiff, water resistant laminated medical or veterinary dressing is described along with a procedure for forming the final hardened dressing. The dressing is obtained by treating a gypsum bandage with an aqueous dispersion of a synthetic resin and then forming a layer from it which is immediately adjacent to a layer formed from a water hardenable synthetic resin bandage. Either layer may be formed first and further layers may be formed so long as the layers alternate between those formed from wraps of the gypsum bandages and those formed from wraps of the synthetic resin bandage.
摘要:
The present invention is directed to polyisocyanate mixtures which are liquid and stable in storage at room temperature and which have an NCO-content of from 36.5 to 45% by weight, consisting essentially of a mixture of from 25 to 70 parts by weight of partly trimerized 2,4-diisocyanatotoluene with from 30 to 75 parts by weight of unmodified 2,4-and/or 2,6-diisocyanatotoluene, a process for the production of these mixtures by mixing the individual components and the use of the mixtures as a synthesis component in the production of polyurethane plastics by the isocyanate-polyaddition process.
摘要:
In a method for determining weighting factors for the color calculation of a color value of texels for a footprint covering a plurality of texels in a texel grid, in a graphic system, form information of the footprint is determined at first. Afterwards, the edges of the footprint are determined and the edges determined in this way are approximated by a staircase function. The texels of the texel grid contacted by the staircase function are determined and a weighting factor is determined for each texel containing a portion of the staircase function, depending on the subarea of the respective texel covered by the footprint.
摘要:
In a method for determining weighting factors for the color calculation of a color value of texels for a footprint covering a plurality of texels in a texel grid, in a graphic system, form information of the footprint is determined at first. Afterwards, the edges of the footprint are determined and the edges determined in this way are approximated by a staircase function. The texels of the texel grid contacted by the staircase function are determined and a weighting factor is determined for each texel containing a portion of the staircase function, depending on the subarea of the respective texel covered by the footprint.
摘要:
In a method for determining weighting factors for the color calculation of a color value of texels for a footprint covering a plurality of texels in a texel grid, in a graphic system, form information of the footprint is determined at first. Afterwards, the edges of the footprint are determined and the edges determined in this way are approximated by a staircase function. The texels of the texel grid contacted by the staircase function are determined and a weighting factor is determined for each texel containing a portion of the staircase function, depending on the subarea of the respective texel covered by the footprint.
摘要:
The invention relates to a method of setting contrast in digital image processing in which a brightness distribution in the form of a histogram is produced from image pixels and the histogram is revised with the help of transfer functions, and in which a linear increase in contrast takes place in a region of the image.
摘要:
In a method for determining weighting factors for the color calculation of a color value of texels for a footprint covering a plurality of texels in a texel grid, in a graphic system, form information of the footprint is determined at first. Afterwards, the edges of the footprint are determined and the edges determined in this way are approximated by a staircase function. The texels of the texel grid contacted by the staircase function are determined and a weighting factor is determined for each texel containing a portion of the staircase function, depending on the subarea of the respective texel covered by the footprint.