16results about How to "Low hydroxyl content" patented technology

The invention discloses trialkoxy functionalized polysiloxane and a preparation method and application thereof.The trialkoxy functionalized polysiloxane has the structural formula shown in the specification, a trialkoxy group is designed in the middle chain segment of polysiloxane, and the group can react with hydroxyl on the surface of filler to be connected, so that the functionality of the polysiloxane is improved, and the service life of the polysiloxane is prolonged. The surface of the filler is coated with an organic layer composed of two hydrophobic polysiloxane chain segments and one methyl group. As a polysiloxane chain segment generated on the surface of the filler is the same as the molecular structure of a polysiloxane matrix, the inorganic filler treated by the technical scheme not only has good stability in the polysiloxane matrix, is not easy to settle, but also has a higher filling coefficient, and is particularly suitable for preparing a thermal interface material with a high heat conductivity coefficient. # imgabs0 #

The invention discloses a high-strength waterproof and oil-proof green paper-based packaging material and a preparation method thereof. The high-strength water-proof and oil-proof green paper-based packaging material is obtained by coating a wet paper web with carboxylated wood nanocellulose and then carrying out hot pressing and drying, the wet paper web is obtained by mixing bamboo pulp, bagasse pulp and wood nanocellulose prepared by a mechanical method, dispersing the mixture in an aqueous solution, making paper with the wet paper web with the water content of 50-60%, and squeezing at normal temperature to remove water until the water content is 20-30%. The paper-based barrier material is prepared by using plants as raw materials and regulating and controlling the fiber paper-based structure through functional components of the plants, has the characteristics of high oil resistance, high tensile strength, good water resistance, greenness, safety and degradability, and is particularly suitable for the fields of food packaging, medical treatment and public health and the like.

The invention discloses an ultrahigh-temperature chlorination process and device for low-hydroxyl high-purity quartz sand, the process and device can realize chlorination roasting of the quartz sand at the highest temperature of 1600 DEG C, a chlorinating agent is dry Cl2, the chlorination time is adjustable, and the problems that a traditional chlorination process and equipment for the quartz sand are short in chlorination time, low in impurity element removal efficiency, high in hydroxyl content and the like are solved. The quartz sand is subjected to high-temperature chloridizing roasting and is combined with a high-frequency ultrasonic strengthening washing process, the content of impurity elements in the quartz sand is smaller than or equal to 15 ppm, the content of hydroxyl in the quartz sand is greatly reduced (smaller than or equal to 10 ppm) compared with a traditional chloridizing process, and the quartz sand is high-quality low-hydroxyl ultra-high-purity quartz sand for quartz crucibles and high-temperature-resistant quartz glass in the photovoltaic and semiconductor industries.

The invention discloses vinyl MQ silicon resin with high dispersibility and low thermal weight loss and a preparation method thereof, and the preparation method comprises the following steps: (1) mixing and stirring water, an organic solvent, a catalyst and an end-capping reagent for 30 min, then heating to 60-75 DEG C, and reacting for 0.5-1.5 h; (2) cooling to 30-45 DEG C, dropwise adding 100 parts of tetraethoxysilane into the mixed solution for 0.5-1 hour, and continuously keeping the temperature at 30-45 DEG C to react for 0.5-1 hour after dropwise adding is completed; (3) raising the temperature to 60-80 DEG C, and continuously reacting for 4-6 hours; (4) adding alkali for neutralization after the reaction is finished, adding an extracting agent for extraction after the neutralization is finished, separating liquid, and washing to be neutral; (5) gradually heating the washed neutral mixture to 120 DEG C, and removing residual water; and heating to 150 DEG C, and removing the solvent in vacuum to obtain the powdery silicon resin. By controlling the temperature of different reaction stages, the hydrolysis rate and the polycondensation rate of different reactants are controlled, and the dispersity and the thermal stability of the final product are improved; the product is high in hydrolytic condensation degree, low in final alkoxy and hydroxyl content and suitable for reinforcement of addition type liquid glue.

The invention discloses a preparation process of phosphate glass with low hydroxyl content and high uniformity. A secondary melting process is mainly adopted, uniform and bubble-free phosphate glass is obtained through high-temperature melting, glass dewatering is performed through secondary in-tube atmosphere low-temperature melting, and free forming of the glass in a furnace is performed by adopting a crucible which is not mutually wetted with the glass to reduce glass pouring stripes. In the process, the volatilization of the components is reduced by using a lower secondary melting temperature, the water removal of the glass is performed by introducing gas, and meanwhile, the glass is freely formed in the crucible by adopting the crucible which is not moistened with the molten glass, so that the pouring stripes of the glass are reduced, and the optical uniformity of the glass is improved.

The invention relates to a preparation method and stretching equipment of a large-proportion pipe. The large-proportion pipe is characterized in that the outer diameter / inner diameter of the pipe is larger than 5. The preparation method comprises the following steps: preparing a pure quartz hollow pipe blank by using OVD, carrying out inner and outer diameter grinding processing on the pure quartz hollow pipe blank to obtain a pure quartz hollow sleeve with small wall thickness deviation, drawing the pure quartz hollow sleeve into a pure quartz pipe by using a vertical melting and drawing device, vacuumizing in the drawing process, and giving a certain relative vacuum degree to obtain the pure quartz pipe. And controlling the ratio of the pipe to the outer diameter / inner diameter to be more than 5. The pure quartz hollow tube blank is prepared through the OVD technology, the requirement for high purity of the quartz tube material is met, the hydroxyl content is low, the machining efficiency is high, and the manufacturing cost is low; the vertical melting and stretching equipment is simple and reasonable in structural arrangement, the annular thermal field is uniformly distributed, and the drawing processing quality of the pure quartz pipe is ensured; and meanwhile, the ratio of the outer diameter to the inner diameter is changed and controlled through the vacuumizing function of the vertical melting and stretching equipment.

The present invention relates to a preparation method of low-hydroxyl and low-alkali metal high-purity quartz sand, which uses igneous rock vein quartz as raw material, first crushes the raw material to make sand, obtains raw material quartz sand, then uses HF as pH adjuster and activator, and uses dodecylamine as collector to float the raw material quartz sand; then uses HF and ferrate as composite acid solution to carry out oxidative pickling and impurity removal; after oxidative pickling and impurity removal, the quartz raw material is mixed with carbon powder, and then calcined at a high temperature of 1100-1350°C; uses halogen acid and heavy metal complexing agent as composite acid solution to pickle and impurity removal the obtained quartz raw material, and after pickling, washes and dries to obtain the low-hydroxyl and low-alkali metal high-purity quartz sand. The obtained quartz sand of the present invention can meet the standards of high-purity quartz sand for semiconductor quartz glass and high-purity quartz sand for photovoltaic quartz crucible.

The utility model belongs to the technical field of quartz sand preparation, and particularly relates to a vacuum sintering device. The vacuum sintering device provided by the utility model can provide a vacuum environment for quartz sand preparation, impurities in gas-liquid inclusion can be more effectively removed in a high-temperature vacuum state, the purity of the quartz sand is improved, the vacuum environment has no pollution source, and the quality of the quartz sand can be effectively controlled. Meanwhile, the vacuum environment is beneficial to inhibiting volatilization and diffusion of some impurities and preventing the impurities from entering the quartz sand again; the high-temperature vacuum state is beneficial to removal of hydroxyl in the quartz sand. According to the vacuum sintering device provided by the utility model, quartz sand can be prepared by adopting single equipment, the prepared quartz sand is high in purity which is more than 99.998%, the hydroxyl content is low, the hydroxyl content is less than 1ppm, the granularity is 0.1-0.3 mm, the quartz sand can be used as a raw material of inner-layer sand of a photovoltaic or semiconductor quartz crucible, meanwhile, the production efficiency is improved, and the vacuum sintering device is green and environment-friendly.

The invention discloses a preparation method of castor oil modified polycarbonate diol, and belongs to the technical field of polyols. According to the invention, mercaptoethanol is creatively used as a hydroxyl expanding agent, so that mercaptoethanol reacts with unsaturated double bonds of castor oil based on a thiol-ene click reaction, and conversion from the unsaturated double bonds to the hydroxyl in a castor oil molecular structure is realized; then taking an acyl chloride compound containing two terminal acyl chloride groups as a cross-linking agent, carrying out deacidification bonding based on acyl chloride and hydroxyl, and dropwise adding the acyl chloride compound and the cross-linking agent into the polycarbonate diol, so as to complete modification of the castor oil on the polycarbonate diol. When the modified product is used as polyhydric alcohol to prepare a waterborne polyurethane emulsion, the waterborne polyurethane emulsion can have excellent high-temperature resistance.

Embodiments of the present application provide a low-loss optical fiber preform, a preparation method thereof and a low-loss optical fiber. The method comprises: performing dehydroxylation treatment on a silica loose body to obtain a first intermediate; performing fluorine doping treatment and first sintering on the first intermediate in a fluorine-containing gas to obtain a second intermediate; performing second sintering on the second intermediate in a mixed atmosphere of an inert gas and the fluorine-containing gas to obtain the low-loss optical fiber preform; and the temperature of the first sintering is lower than the temperature of the second sintering. The method is used to improve the uniformity of the doping of fluorine elements in the optical fiber preform to reduce the transmission loss of the optical fiber preform at 1550 nm.

The invention discloses a method for preparing a super-transparent flexible PVB resin powder without Tyndall effect, and belongs to the technical field of PVB resin processing. The invention is used to solve the technical problem that two PVAs in the prior art easily lead to slight differences in the refractive index of the finished product, and when the PVB film is thicker, the Tyndall effect is likely to occur under strong light, affecting the light transmission performance of the product. A method for preparing a super-transparent flexible PVB resin powder without Tyndall effect comprises the following steps: adding polyvinyl alcohol and purified water to a three-necked flask and stirring, raising the temperature of the three-necked flask to 50-60°C, and stirring until the system is dissolved. The present invention selects a polyvinyl alcohol as a raw material, and after modifying it, it is compounded with a polyoxyalkylene with a long straight chain structure to prepare a PVB resin powder that is easy to process and has good sound insulation and noise reduction effects, which not only effectively reduces the yellow index, improves its high temperature resistance, but also avoids the generation of the Tyndall effect.

The present invention provides a large-size quartz glass and a preparation method and system thereof, comprising the following steps: performing a dehydroxylation treatment and a sintering treatment on the silicon dioxide loose body to obtain a quartz glass blank; placing the quartz glass blank in a mold cavity for a first differential heat treatment and applying pressure to the quartz glass blank in a first direction to obtain the quartz glass; wherein the mold cavity includes a first temperature region and a second temperature region in sequence along the first direction, and the quartz glass blank includes a second part corresponding to the second temperature region and a first part corresponding to at least part of the first temperature region; in the first differential heat treatment, the temperature of the second temperature region is higher than the temperature of the first temperature region, and the temperature of the second temperature region is not less than 1600°C, so that the preparation of high-quality quartz glass with large size, low hydroxyl content and good optical uniformity can be achieved.

The invention relates to the technical field of TPU (thermoplastic polyurethane) materials, in particular to a whisker modified TPU cable material, which is prepared from the following raw materials in parts by weight: 70 to 90 parts of thermoplastic polyether-based polyurethane, 10 to 20 parts of ethylene-vinyl acetate copolymer, 10 to 15 parts of modified cellulose whisker, 5 to 10 parts of modified calcium sulfate whisker and 3 to 5 parts of lubricating agent. The whisker modified TPU cable material produced by the invention has the characteristics of excellent flexibility, wear resistance and flame retardance and low cost.

This invention provides a coloring photosensitive resin composition and its application. The coloring photosensitive resin composition comprises an alkali-soluble resin, a photosensitive compound, a colorant, a first crosslinking agent, and a second crosslinking agent. The first crosslinking agent has a structure as shown in Formula I, and the second crosslinking agent has a structure as shown in Formula II. Through the design of the first and second crosslinking agents and their mutual compounding with other components, this invention enables the formation of a rich crosslinked network structure after high-temperature curing, reducing the hydroxyl content and significantly lowering the moisture absorption rate of the resulting coloring-cured film. Furthermore, the coloring-cured film exhibits significantly improved heat resistance, chemical corrosion resistance, water vapor corrosion resistance, mechanical strength, and barrier properties, thereby increasing the yield of display devices containing it and providing advantages such as good heat resistance, high reliability, and high pixel stability.

The invention belongs to the technical field of catalysts, and discloses an iron-based catalyst and a preparation method and application thereof. The preparation method of the iron-based catalyst comprises the following steps: mixing an iron salt, an organic acid salt and an organic solvent, crystallizing to obtain a solid, impregnating the solid with a modified solution, drying, and roasting in a reducing atmosphere to obtain the iron-based catalyst, the modified solution comprises an alkyl trimethyl ammonium bromide solution. The iron-based catalyst prepared by the preparation method can realize high CO2 conversion rate, high olefin selectivity and excellent water oxidation resistance stability.

The invention discloses a rare earth doped ABF3 perovskite type nano luminescent material and a preparation method and application thereof, the general formula of the luminescent material is ABF3: x mol% Lnn < + >, A is selected from at least one of alkali metals Li, Na, K, Rb and Cs; b is selected from at least one of alkaline earth metal or transition metal Mg, Ca, Sr, Ba, Mn, Zn, Cd, Co, Ni and Cu; f represents a fluorine element, and Ln represents a lanthanide rare earth element; x mol% represents the percentage of lanthanide rare earth ions accounting for the total mole number of alkaline earth metal or transition metal and lanthanide rare earth elements, 0 lt; x is less than or equal to 80; and n is 2 or 3. The internal hydroxyl defect of the nano-luminescent material is effectively inhibited, and the rare earth ions are doped in the nano-luminescent material in a heterovalent manner, so that cross relaxation among the rare earth ions can be promoted, and high-order nonlinear photon avalanche up-conversion of the nano-luminescent material at room temperature is realized.