摘要:
The invention relates to a process for the manufacture of noncellular polyurethane elastomers by reacting 4,4'-diisocyanato-1,2-diphenylethane or diisocyanato-1,2-diphenylethane isomer mixtures with a 4,4'-diisocyanato-1,2-diphenylethane content in excess of 95 percent by weight, higher molecular weight polyhydroxyl compounds and low molecular weight chain extenders optionally in the presence of auxiliaries and additives.The polyurethane elastomers produced in accordance with this invention excel by a greater hardness and improved mechanical properties compared with polyurethane elastomers based on 4,4'-diphenylmethane diisocyanate with otherwise comparable composition.
摘要:
The invention relates to a method for the preparation of cellular polyurethane elastomers with densities of approximately 250 to 800 grams per liter by reacting 4,4'-diisocyanato-1,2-diphenylethane or a diisocyanato-1,2-diphenylethane isomer mixture with a 4,4'-diisocyanato-1,2-diphenylethane content of more than 95 percent by weight with higher molecular weight polyhydroxyl compounds and water, as well as optionally chain extenders in the presence of auxiliaries and/or additives according to the one-shot or preferably the prepolymer method in closed molds.Compared with products based on 4,4'-diisocyanatodiphenylmethane, the polyurethane elastomer molded parts have improved physical and thermal properties.
摘要:
The invention relates to stable, pulverulent lycopene formulations, comprising lycopene having a degree of crystallinity of greater than 20%, processes for their preparation and their use as an additive to foodstuffs, cosmetics, pharmaceuticals and animal feedstuffs.
摘要:
Carotenoid preparations in the form of coldwater-dispersible powders are produced bya) preparing a molecular-disperse solution of a carotenoid, with or without an emulsifier and/or an edible oil, in a volatile, water-miscible, organic solvent at elevated temperature and adding therein an aqueous solution of a protective colloid, whereupon the hydrophilic solvent component is transferred into the aqueous phase, and the hydrophobic phase of the carotenoid results as nanodisperse phase,b) heating the resulting hydrosol at from 40.degree. C. to 90.degree. C., with or without cooling of the hydrosol to from 0.degree. C. to 30.degree. C. beforehand, andc) removing the solvent and the water from the heated hydrosol, and converting it into a water-dispersible dry powder.
摘要:
Acicular ferromagnetic chromium dioxide is stabilized by treatment with an alkali metal hydroxide in an aqueous alkaline suspension at elevated temperatures.