38results about How to "Small particle size range" patented technology

The invention discloses a process for preparing an autocatalysis degradable pesticide in environment, which comprises the steps of, mixing octahedrite type titanium dioxide nano powders, pesticides and surface active agent, dissolving them in solvent, stirring homogeneously to obtain mother liquor, the mass percent of octahedrite type titanium dioxide nano powders, surface active agent, pesticides and solvent is 1:5-20:5-40:50-200, adsorbing the mother liquor homogeneously onto the inert support, and removing dissolvent through vacuum drying.

The invention discloses a synthesis method of hydroxylated polyvinyl chloride copolymer resin. The synthesis method comprises the following steps of: adding hydroxyethyl methacrylate (HEMA) and an initiator II in a mixture of a composite emulsifying agent, an initiator I, water, a pH regulation agent, seed emulsion and a vinyl chloride monomer in a fluid mode, conducting polymerization reaction, and conducting spray drying on prepared emulsion to obtain the hydroxylated polyvinyl chloride copolymer resin, wherein the composite emulsifying agent is composed of an emulsifying agent I and an emulsifying agent II; the emulsifying agent I is sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, sodium lauryl sulfate, nonyl aryl polyether alcohol, ammonium laurate, polyoxyethylene nonyl phenyl ether or polyoxyethylene octylphenol ether; and the emulsifying agent II is tetradecyl alcohol, setanol, stearyl alcohol, dodecanoic acid, tetradecanoic acid, tetradecanoic acid, octadecanoic acid, hexadecane or octodecane. The synthesis method is simple in equipment, solves the problems of low reaction conversion rate, large HEMA homopolymerization rate, low HEMA content in polymer and the like, and is low in cost, saving in energy consumption and less in pollution discharge.

The invention discloses a method for packaging LED lamp beads with a high Bin drop rate. The method is characterized in that a drum-type fluorescent powder screening device is adopted to screen fluorescent powder, wherein the device comprises at least two screening drums which are sequentially arranged in a sleeved manner from the center out, the wall of each screening drum is provided with screening holes, the screening holes of the screening drums are sequentially reduced in diameter from the inside out, and the screening drums are connected to a rotation driving mechanism which drives the screening drums to rotate and a vibration mechanism which enables the screening drums to vibrate. In addition, the device can screen the fluorescent powder automatically, so that the consistency of the fluorescent powder in particle diameter is improved, the work efficiency is high, and the labor cost is low, thereby being suitable for mass industrial production. The screened fluorescent powder is easier to package, and the glue is mixed evenly, so that requirements for a glue stirring process and device and the difficulty in operation are reduced. In addition, the amount of the fluorescent powder in the packaging glue injected into a bracket can be effectively controlled, the brightness and color consistency of packaged LED lamp bead products is improved, the reject ratio is reduced, and the economic benefit of packaging enterprises can be significantly improved.

The invention relates to a lead-free high-Curie temperature PTCR (positive temperature coefficient resistor) ceramic material and a preparation method thereof. The composition of the ceramic material is of Ba1-x (Bi0.5Na0.5)xTiO3, wherein x is not less than 0 and not more than 0.06. A sol-gel method is adopted for preparing the lead-free PTCR material and the method, the sintering temperature of a traditional solid-phase reaction method is too high, when the temperature is above 1300 DEG C, BNT (Bi0.5Na0.5TiO3) is very easy to decompose during the sintering process, and the material is further difficult to be semi-conducted; and by adopting the sol-gel method according to the invention, the sintering can be performed at the temperature of 1250 DEG C, and the sintering temperature is reduced. When the BNT content is more than 2mol%, the sintering and the semi-conduction can not be performed in an air atmosphere by using the traditional solid-phase reaction method, and the sintering needs to be performed under a reducing atmosphere. However, when the BNT content is 5mol%, the material still has the properties of a semi-conductor by using the method disclosed by the invention, and the Curie temperature is obviously increased.

The invention relates to the technical field of preparation of aluminum hydroxide, in particular to a preparing method of superfine super-white aluminum hydroxide micropowder. The method includes thesteps of injecting a sodium aluminate solution into a crystallizing reactor, arranging six feeding pipes in the crystallizing reactor, forming a discharge port in the bottom of the crystallizing reactor, arranging a material distributing groove in the top end of the crystallizing reactor, making the six feeding pipes communicated with the bottom of the material distributing groove, making the discharge port communicated with the top end of the material distributing groove through a circulating pump, and making the six feeding pipes evenly distributed on the top edge of the crystallizing reactor and incline towards the center of the crystallizing reactor by 5-60 degrees so that materials in the crystallizing reactor can be cyclically distributed at multiple angles and the sodium aluminate solution can be evenly distributed after the multi-angle material distribution of the feeding pipes. The particle size range of the obtained aluminum hydroxide micropowder is narrowed, the whiteness variation range is greatly narrowed, the whiteness is improved, and the quality of the aluminum hydroxide micropowder is improved.

A method for upgrading coal fines by separating out at least some mineral components is provided. The method comprises the treatment of optionally graded coal fines with microalgae in aqueous medium to form a slurry under conditions that permit adsorption of microalgae onto particles of coal fines. The slurry is treated to separate a first fraction that is rich in coal fines together with adsorbed microalgae thereon from a second fraction that has more mineral components in it than does the first fraction and processing the first fraction to recover upgraded coal fines therefrom. Contacting is preferably carried out in a manner aimed at loading the coal fines generally evenly with microalgae adsorbed thereon in an amount of from 5 to 15% by weight of coal fines. Separation may be carried out by sedimentation, cyclone separation or flotation.

The invention provides a ferroferric oxide nanoparticle and a preparation method thereof. The particle size of the nanoparticle is between 20-30nm, the saturation magnetization is above 70emu / g, the remanence is below 0.2emu / g, and the coercivity is below 0.2emu / g. The force is below 1.0Oe, and the preparation method includes the following steps: (A) dissolving the ferrous salt to form a reaction solution, adding alkali to adjust the pH of the reaction solution to between 6-9, and ultrasonically reacting at 60-80°C for 2-6h; (B) Raise the temperature to 80-90°C to react and mature for 0.5-1.5h, cool, centrifuge and dry in vacuum. The iron ferric oxide nanoparticles prepared by the present invention have relatively small particle size range, excellent magnetic performance, high saturation magnetization, very small remanence and coercive force, and the direction of easy magnetization between nanoparticles is the same on the microstructure , showing good superparamagnetism.

The invention discloses a waterborne epoxy resin emulsion for glass fibers and a preparation method of the waterborne epoxy resin emulsion. By using diol compounds of oxiron and ethylnen oxide emulsifier and shearing and stirring at high rotating speed of 8000r / min and simultaneously combining a phase inversion technique, the prepared epoxy resin emulsion finishes the process from a water-in-oil flow to an oil-in-water flow; the particle size range of the prepared emulsion is 150 to 300nm; the waterborne epoxy resin emulsion has the characteristics of narrow particle size range, concentrated particle size distribution and stable centrifugal performance; after the waterborne epoxy resin emulsion is stood at normal temperature and normal pressure for 12 months, no demulsification or layering phenomenon is cuased; after the emulsion is dried at the temperature of 110DEG C, a formed membrane is hard, good in toughness and high in strength.