42 results about "Isotropic pitch" patented technology

The invention discloses a method for preparing a pitch-based carbon fiber, relates to the carbon fiber and a preparation method thereof, and provides the method for preparing the pitch-based carbon fiber which has the advantages of high mechanical performance, simple production process, low cost, stable product performance and the like. The method comprises the following steps of: heating anisotropic pitch and isotropous pitch under the protection of inert gas; mechanically stirring in a molten state at a constant temperature; cooling to obtain a mixed pitch raw material; placing into a spinning barrel of a melt spinning machine; loading in a pitch carbon fiber forming device; heating under the protective gas to a melt spinning temperature to obtain a precursor fiber at a spinning nozzle;placing on a sample carrying table; placing in a high temperature furnace; setting a heating program; performing oxidation treatment and naturally cooling to obtain an oxidized fiber; and placing a cross-linked oxidized fiber on the sample carrying table, placing in the high temperature furnace, setting a heating program, introducing the inert gas for protection, performing carbonization treatment and then naturally cooling to obtain the pitch-based carbon fiber.

A process and apparatus for making isotropic pitch are disclosed. A tubular reactor operating at high velocity and pressure converts aromatic rich liquid feed to pitch within minutes. Reactor is heated by electric resistance or inductance, a salt or molten metal bath, or fired heater. Reactor effluent flashes and isotropic pitch recovered from the flash drum. Softening point is affected by flash drum pressure or stripping steam. Unconverted feed may be recycled. Process makes little gasoline, simple condensation of flash drum vapor may produce gas oil and gasoline fractions. Isotropic pitch is made in a single step with a coking value of 50 to 55 wt %. Time and temperature in the reactor convert at least 20 wt % of feed and any recycle material present to isotropic pitch. Pressure is preferably above 500 psig, to suppress mesophase formation and produce isotropic pitch with less than 0.5 wt % mesophase.

The invention discloses a method for manufacturing high thermal conductivity pitch-based carbon fiber composite material prefabricated body. The method includes: alternatively stacking pre-oxidized or low-temperature carbonized high thermal conductivity pitch-based carbon fiber continuous layers and viscose glue-based or polyacrylonitrile-based or isotropy pitch-based or high thermal conductivity pitch-based short carbon fiber webs; inducing Z-directional reinforcing fibers in the axial direction of the continuous layers and the web layers through a needle punching technology; the Z-directional reinforcing fibers can get through a Z-directional heat conduction channel, Z-directional dredging and conduction of heat is facilitated, the needle punching density is controlled in 10-50/cm<2>, and the volume density of a three-directional structure prefabricated blank is 0.25-0.75 g/cm<3>; and carbonization and graphitization treatment is performed on the prefabricated blank. The method can form a large-diameter high thermal conductivity pitch-based carbon fiber special-shaped blank, and the forming size and shape are not limited; and the method can manufacture high thermal conductivity pitch-based carbon fiber composite materials, and is suitable for batch industrial production.

The invention discloses a method for reinforcing a steel structure through FRP (Fiber Reinforced Polymer). The FRP adopted in the invention is carbon fibre reinforced polymer (CFRP), specifically, mesophase pitch (MP) based carbon fiber is used as raw material, the mesophase pitch based carbon fiber is the fiber obtained by spinning processing of pitch obtained through thermal polymerization of isotropic pitch with high aroma content, and having a mesophase or liquid-crystal structure, and the stress performance of the fiber is improved, so that a reinforcing effect is realized. The method has the characteristics that since the fiber reinforced polymer (FRP) has the characteristics of being high in specific strength and specific stiffness, and corrosion-resistant, the fiber reinforced polymer (FRP) is widely applied to reinforcing of a concrete structure, and the steel structure reinforced through the fiber reinforced polymer (FRP) has a good effect. The method for reinforcing the steel structure through the fiber reinforced polymer (FRP) has the characteristics that the specific strength is high, rapid construction is achieved, and bearing capacity of the structure is obviously improved after construction.

The invention discloses a method for preparing a carbon material by use of heavy oil. The method adopts the heavy oil as a raw material to produce intermediate-phase spun asphalt, isotropic spun asphalt and COPNA resin through the following steps: 1, pretreating the heavy oil, and removing free carbon granules and dimethyl benzene insoluble substances from the heavy oil to obtain refined heavy oil; 2, treating the refined heavy oil through a proper thermal poly-condensation process to obtain pyrolysis heavy oil; 3, dissolving, washing and separating the pyrolysis heavy oil by use of dimethyl benzene to obtain a dimethyl benzene soluble component and a dimethyl benzene insoluble component; 4, dissolving the dimethyl benzene insoluble component by use of a hydrogenated heavy solvent and performing a hydrogenation and co-carbonization reaction to obtain hydrogenated asphalt; 5, thermally treating the hydrogenated asphalt to obtain intermediate-phase asphalt; 6, separating the solvent from the dimethyl benzene soluble component obtained in the step 3 and removing the dimethyl benzene solvent to obtain the soluble component; 7, recycling a part of the soluble component in the step 2 and making the part have thermal poly-condensation with the refined heavy oil, and thermally treating the other part to obtain the isotropic spun asphalt; and 8, letting distillate oil which is at a temperature lower than 350 DEG C and obtained by separation during the thermal treatment in the step 7 have a cross-linkage reaction with a cross-linking agent to obtain the CNPNA resin.

The invention relates to a high-strength and high-density graphite material and a preparation method. The preparation method includes the steps of S1, using an organic solvent to dissolve soft asphalt to obtain a soft asphalt solution, using the soft asphalt solution to spray calcined fine coke powder, and mechanically mixing into isotropic asphalt powder to obtain a mixture; S2, performing compression molding on the mixture to obtain a green body, calcining the green body once, using impregnation asphalt to perform density increasing, and performing second calcining and graphitizing to obtain the high-density graphite material. The preparation method has the advantages that the surface of the calcined coke powder can be moistened and even in soft asphalt coating by the liquid spraying technology, and the interface compatibility and isotropic degree of the coke powder are increased; the isotropic asphalt can be evenly decomposed during the calcining, the calcined isotropic asphalt and the coke powder aggregate are consistent in shrinkage, material internal stress is relieved, and yield is increased evidently; the high-strength and high-density graphite material is prepared by one impregnation, two calcinations and one graphitizing, and the method is simple in process, low in cost, good in repeatability and short in production cycle.

The invention provides a preparation method and a preparation device of isotropic pitch coke. The preparation method includes the steps of S1, subjecting molten pitch to atomization to obtain atomized pitch; S2, pyrolyzing the atomized pitch by contacting with high-temperature gas to obtain isotropic pitch coke, wherein the temperature of the high-temperature gas ranges from 500 DEG C to 1400 DEG C. The molten pitch is atomized and carbonized, the retention time for high-temperature carbonizing stage of pitch is short, and the intermediate phase process is omitted so that the isotropic pitch coke is obtained directly; further, the isotropic pitch coke can be utilized directly for producing isotropic graphite, the procedure of grinding and fining is omitted, the technique is simplified, and the lengthiness of processing flow is avoided; in addition, the isotropic pitch coke has low porosity which is favorable for improving strength of graphite.

A process for producing a carbon foam heat sink is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications. The foam is encased and filled with a phase change material to provide a very efficient heat sink device.

A method of manufacturing an isotropic pitch-based carbon fiber spun yarn fabric includes the following steps of: obtaining composite yarn by winding a water-soluble polymer fiber around a surface of isotropic pitch-based carbon fiber spun yarn; obtaining a composite yarn fabric by weaving the composite yarn; and obtaining the isotropic pitch-based carbon fiber spun yarn fabric by dissolving and removing the water-soluble polymer fiber from the composite yarn fabric.

A mixture of carbon-containing fibers, such as mesophase or isotropic pitch fibers, and a suitable matrix material, such as a milled pitch, is compressed while resistively heating the mixture to form a carbonized composite material having a density of about 1.5 g/cm³, or higher. The composite material is formed in under ten minutes. This is a significantly shorter time than for conventional processes, which typically take several days and achieve a lower density material. Consequently, carbon/carbon composite materials having final densities of about 1.6-1.8 g/cm³, or higher are readily achieved with one or two infiltration cycles using a pitch or other carbonaceous material to fill voids in the composite and rebaking.

Insulation materials suited to high temperature applications, such as the insulation of furnaces, are formed from a mixture of pitch carbon fibers, such as isotropic pitch carbon fibers, and a binder comprising a solution of sugar in water. The sugar solution is preferably at a concentration of from 20-60% sucrose to yield a low density material having high flexural strength and low thermal conductivity when carbonized to a temperature of about 1800° C.

The invention relates to a preparation method of mesophase pitch continuous filaments. A small amount of incompatible isotropic pitch with similar softening points is added to mesophase pitch, and after the isotropic pitch is subjected to melt blending through twin screws, the isotropic pitch passes a static mixer, and is metered, spun and wound to obtain the mesophase pitch continuous filaments. The obtained mesophase pitch continuous filaments are large in elongation at break, low in brittleness and good in operability, and particularly meet the requirements of high-speed spinning, and an oiling process and a filament collecting process are greatly simplified.

The invention belongs to the technical field of lithium ion battery materials, and discloses a nitrogen-doped mesonphase carbosphere and a preparation method and application thereof. The nitrogen-doped mesonphase carbosphere comprises a mesonphase carbosphere body and nitrogen, wherein the nitrogen is doped in a lamellar structure of the mesonphase carbosphere body. The preparation method comprises the following steps: heating asphalt to a semi-solidified state, then introducing naphthalene steam to obtain isotropic pitch, carrying out a thermal polycondensation reaction on the isotropic pitch, then conducting cooling, carrying out extracting, subjecting an aqueous extract to filtering, cleaning and drying so as to obtain the mesonphase carbosphere body, uniformly mixing the mesonphase carbosphere body, a defect introducing agent and a polar solvent, successively conducting drying and sintering to obtain a mesonphase carbosphere body with defects, mixing the mesonphase carbosphere body with defects with ammonia water, carrying out a heating reaction, conducting filtering, and cleaning filter residues to obtain the nitrogen-doped mesonphase carbosphere. According to the nitrogen-doped mesonphase carbosphere synthesized by using the method, the uniformity of the nitrogen-doped mesonphase carbosphere can be greatly improved, and the nitrogen-doped mesonphase carbosphere has excellent charge-discharge capacity and structural stability.

The invention discloses a production method of mesophase pitch. The production method of the mesophase pitch comprises the following steps of using petroleum pitch as a raw material, adding an additive, under protection of nitrogen, conducting thermal treatment at 380-420 DEG C for 2-10 hours, subjecting organic molecules in the additive to a heterogeneous nucleation and condensation reaction with ash in the raw material used as cores to form anisotropic pitch microbeads which wrap the ash, at 300-380 DEG C, standing and conducting sedimentation for 2-10 hours, separating out upper-layer isotropic pitch and lower-layer anisotropic pitch, taking the upper-layer isotropic pitch as a raw material, and under protection of nitrogen, conducting thermal treatment at 380-420 DEG C for 5-15 hours to obtain the high-quality mesophase pitch. By adopting the method, the high-quality mesophase pitch with an ash content lower than 50 ppm can be produced. By circularly purifying the raw material, ultra-pure mesophase pitch with an ash content lower than 25 ppm can be produced, and the ultra-pure mesophase pitch with the ash content lower than 25 ppm can be used as a raw material of mesophase pitch carbon fibers, high-purity graphite and mesophase pitch foamy carbon.