33results about How to "Powder particle size is small" patented technology

The invention discloses a polyimide extinction powder and a preparation method thereof, a polyimide film containing the same and a preparation method thereof. The preparation method of the polyimide extinction powder comprises the steps of obtaining a polyamide acid resin solution; after heating the polyamide acid resin solution to 80-100 degrees centigrade to carry out heat preservation reactionon the polyamide acid resin solution for a certain time, adding a nucleating agent dispersion liquid; heating an obtained material to a temperature of less than or equal to 180 degrees centigrade forheat preservation reaction; after reaction is finished, separating out particles; and collecting the particles to obtain the polyimide extinction powder. In the preparation method of the polyimide film, the polyimide extinction powder prepared by using the preparation method of the polyimide extinction powder is used as a delustering agent. By using the preparation method disclosed by the invention to prepare the polyimide extinction powder, ultrasonic equipment does not need to be used in separate-out reaction, the reaction temperature is low, the production cost is low, the particle size ofthe obtained powder is smaller, and the particle size distribution range of the powder is narrow. The black matte polyimide film prepared by using the preparation method disclosed by the invention hasthe advantage that the obtained film realizes a better matte effect and better mechanical performance and electrical strength under conditions of same particle size and same adding quantity.

The invention provides a method for preparing a composite recycled foam material by using waste EVA-based materials. The method utilizes solid-phase shearing milling technology, and by further limiting the milling process parameters, waste EVA is obtained under suitable conditions. The waste EVA-based ultra-fine flake powder is used to blend and compound the waste EVA-based ultra-fine flake powder with TPU, and the TPU / waste EVA-based composite foam material is further prepared by supercritical carbon dioxide foaming technology. The method of the present invention greatly reduces the particle size and particle size distribution of the waste EVA-based powder on the one hand, and further improves the surface activity of the powder through the flake shape; wherein, the flake powder and granular or strip shape Compared with the appearance, it further improves the melt blending with TPU, and finally combines the supercritical carbon dioxide foaming technology to prepare a higher performance TPU / waste EVA-based composite foam material / product.

The invention relates to an electrode for a low-temperature fuel cell, specifically PTFE / C composite powder used for the electrode of the low-temperature fuel cell. The carbon-supported polytetrafluoroethylene composite is prepared conveniently and rapidly by using microwave dielectric heating technique. The composite is in powder form after preparation without needing any mechanical mill, and the particle size of the powder is in the range from 5-30 Mu m. A proton-conducting polymer (such as Nafion) is loaded on a catalyzer by using a liquid-phase in-situ precipitation method, to make a catalyzer / proton-conducting polymer composite, and the atalyzer / proton-conducting polymer composite is added to the PTFE / C composite to make a catalyzer / proton-conducting polymer / PTFE / C composite which is the basic structural unit of an electrode and used to prepare electrodes. The electrode prepared by the method has a catalyzer utilization rate above 50 percent, has sufficient transmission channels for gas, proton, electron and water, and exhibits excellent electrochemical property.

the invention discloses a chemical heat disposing method of steel surface, which comprises the following steps: 1. fetching steel working piece; 2. obtaining nanometer aluminium nitride permeating agent with particle size less than 100 nm; 3. heating the steel working piece to 850-1050 deg.c under the contact condition of steel working piece surface and nanometer aluminium nitride permeating agent; keeping at 850-1050 deg.c for 2-6 h; fetching the steel working piece; cooling to indoor temperature; 4. quenching and tempering the steel working piece according to heat disposing standard.

The invention provides a preparation method of montmorillonite superfine powder, comprising the following steps of: a, preparing montmorillonite and an ethanol solution into slurry according to a solid-liquid ratio by weight that the montmorillonite to the ethanol solution is 1: (2-99), wherein the ethanol solution is a mixture of water and ethanol and the volume ratio of the ethanol to the water is 3: (0-1); b, inputting the prepared slurry into superfine equipment to carry out superfine stripping to obtain the slurry; c, removing rough grains of the slurry which is carried out by the superfine stripping by grades through wet-method grading equipment, so as to obtain graded superfine slurry with uniform grain diameters; and d, concentrating, drying and scattering the graded superfine slurry to obtain the montmorillonite superfine powder. The key technology provided by the invention is as follows: the ethanol solution with a certain concentration is used as a medium to disperse the montmorillonite and carry out graded concentration and drying on the montmorillonite through the superfine stripping; and finally, the montmorillonite superfine powder is obtained through a scattering process.

The invention discloses a two-step method for preparing NaLaMgWO 6 The powder method belongs to the technical field of LED phosphor matrix preparation, and the technical scheme includes: 1) according to NaLaMgWO 6 The stoichiometric ratio of each element in , respectively weighed NaNO 3 , La(NO 3 ) 3 , magnesium acetate and ammonium tungstate, and dissolve them in deionized water, then add citric acid to prepare solution A, and then adjust the pH value of solution A to neutral; 2) put solution A in a hydrothermal reaction kettle Carry out hydrothermal treatment, then take out the sample, centrifuge, wash, and dry to obtain the sample powder; 3) Sinter the sample powder in solid phase to obtain NaLaMgWO 6 Powder. The method of the present invention adopts the cooperation of hydrothermal method and low-temperature solid-phase method to prepare NaLaMgWO with high purity, uniform particle size, good crystallization performance and good dispersion performance. 6 Powder.