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229results about How to "Reduce exposure" patented technology

Polyamine slow-breaking quick-setting asphalt emulsifier and preparation method and application thereof

ActiveCN102719106AReduce exposureMeet slow cracking requirementsOrganic compound preparationCarboxylic acid amides preparationPolyethylene polyamineOrganic acid
The invention relates to a polyamine slow-breaking quick-setting asphalt emulsifier and a preparation method and an application thereof. The emulsifier is made through the method as follows: dripping formaldehyde into polyethylene polyamine, and the proportion (mole ratio) of the polyethylene polyamine to the formaldehyde is 1:(0.25 to 4); allowing reacting for 0.5 to 2 hours at room temperature, and then heating to 110 DEG C; allowing reacting for two hours, and heating to 160 to 200 DEG C; allowing reacting for 1 to 3.5 hours, and then cooling to 100 to 110 DEG C, so as to obtain an intermediate after decompressing and dehydrating; adding organic acid by the proportion (mole ratio) of the polyethylene polyamine to the organic acid of (0.5 to 4):1, using dimethylbenzene as a water-carrying agent, and heating the system to 160 to 200 DEG. C; after reaction for 5 hours, cooling to 70 to 80 DEG C, and carrying out reduced pressure distillation, so as to obtain the polyamine slow-breaking quick-setting asphalt emulsifier. Emulsified asphalt prepared through the emulsifier obtained by the invention is uniform and stable, and is proven to be a slow-breaking type through a demulsification test and to be a quick-setting type through an experiment of mixation with quartz sand. The emulsifier can satisfy the requirement of rapid traffic opening.
Owner:HEBEI UNIV OF TECH

Phosgenation reactor and method for preparing isocyanate monomer by using phosgenation reactor

ActiveCN108079921AShort stayReduce exposureIsocyanic acid derivatives preparationOrganic compound preparationIsocyanateHydrogen chloride
The invention discloses a phosgenation reactor and a method for preparing an isocyanate monomer by using the phosgenation reactor. The phosgenation reactor comprises an inner material inlet pipe, an outer material inlet pipe, a mechanical stirring rotation shaft, a rotation area and a kettle body, wherein the rotation area comprises a support structure, a rotation area filler block, an upper material outlet device and a lower material outlet device, the inner material inlet pipe and the outer material inlet pipe are coaxially arranged from inside to outside, the upper material outlet device and the lower material outlet device are arranged in parallel, are connected through the support structure, and are respectively communicated to the outer material inlet pipe and the inner material inlet pipe, the rotation area filler block is filled between the upper material outlet device and the lower material outlet device, the upper material outlet device is connected to the mechanical stirringrotation shaft, and the kettle body is provided with a gas phase material outlet, a liquid phase material outlet, a gas phase material inlet and a liquid phase material inlet. According to the present invention, by pre-treating the hydrochloride solution in the reactor, the salt forming concentration and the quality of the hydrochloride solution are improved while the rapid removal of hydrogen chloride gas during the phosgenation is achieved, such that the generation of chlorination by-products is effectively reduced, and the product separation difficulty is reduced.
Owner:WANHUA CHEM GRP

Preparation method of high-quality AlV55 alloy

InactiveCN106350675AAvoid too much heatReduce exposureAluminium alloyMolten slag
The invention belongs to the field of metallurgy, and particularly relates to a preparation method of high-quality vanadium-aluminum alloy. The preparation method comprises the following steps: by an electrothermal reduction-two-step refining method, using V2O3 with the purity of 99.9%, Al with the purity of 99.70% and CaO with the purity of 97.0% as raw materials, uniformly mixing, taking a part of the raw materials, and mixing with a heating agent as a base material; igniting the base material to form a molten pool, starting an open arc for smelting, and adding the remaining raw materials in batches; in the later reacting stage, performing blowing refining on the alloy and molten slag; after completion of smelting, deslagging, and casting to obtain the vanadium-aluminum alloy. According to the preparation method, high-purity V2O3 is used as a vanadium source, so that compared with use of V2O5, the using amount of a reducing agent can be significantly reduced and introduction of impurities into the raw materials is reduced; an external heat source can prolong the heat-preserving time so as to promote separation of the slag and the alloy; the open arc is started for smelting by virtue of the molten slag, so that the carbon content of the alloy can be reduced; in the later smelting stage, the recycling rate is increased and the impurity content is reduced by refining the slag and the alloy. The final impurity content meets a standard of the AlV50 vanadium-aluminum alloy of the German GfE company.
Owner:NORTHEASTERN UNIV
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