摘要:
The mesophase pitch based and melt blown discontinuous carbon fibers of a peculiar structure are provided. These fibers are characterized in that a large number of small domains, each domain has an average equivalent diameter of from 0.03 .mu.m to 1 .mu.m and has a nearly unidirectional orientation of folded carbon layers, assemble to form a mosaic structure on the cross-section of the said carbon fibers and that the folded carbon layers of each domain are oriented at an angle to the direction of the folded carbon layers of the neighboring domains on the boundary.
摘要:
Flexible materials for reflecting electromagnetic waves can be provided by using adhesive type non-woven fabrics formed by self adhesion of the principal component of pitch based carbon fibers.
摘要:
Milled carbon fibers are provided which have a fiber cut surface and a fiber axis intersecting with each other at cross angles, the smaller one thereof being at least 65° on the average. The milled carbon fibers may have a specific surface area as measured by the BET method of 0.2 to 10 m2/g. The milled carbon fibers may be obtained by a process comprising melt spinning of mesophase pitch, infusibilization, milling of the infusibilized pitch fibers as obtained or after a primary heat treatment at low temperatures in an inert gas and a high-temperature heat treatment in an inert gas. Even when the graphite layer plane has achieved high-level growth, the above milled carbon fibers have low reactivity with a metal of high temperature or the like during the molding or use thereof because the proportion of reactive exposed surface of the inner portion of the fiber is small, so that the use of the milled carbon fibers can improve the mechanical strength and high-temperature heat resistance of the composite material.
摘要:
An ozonizer in which a pair of plate-like electrode plates are arranged opposite to each other so as to form a discharge space therebetween, and ceramic dielectric layers are arranged on the surface on the side of the discharge space of said electrode plates, wherein a plate-like anode 4 is arranged between the dielectrics 31 and 32, extreme ends 41 and 42 having sharp extreme ends of a number of protrusions are formed on both surfaces of the anode 4, the anode 4 is arranged between the dielectrics 41 and 42 in a state where the extreme ends 41 and 42 are in contact with the surfaces of the dielectrics 31 and 32 on both sides, the anode 4 is formed with a number of through-holes extending through both surfaces, and the anode being formed of expanded metal.
摘要:
A mask with rectangular openings is formed on a large-scaled silicon substrate, and an AlN micro crystalline layer is formed in a thickness of 200 nm or over through the mask on the silicon substrate by means of selective and lateral growth. Then, a nitride semiconductor crystal layer with a composition of InxGayAlzN (0≦x, y, z≦1, x+y+z=1) is formed on the AlN micro crystalline layer.
摘要翻译:在大型硅衬底上形成具有矩形开口的掩模,并且通过选择性和横向生长通过硅衬底上的掩模在200nm或更大的厚度上形成AlN微晶层。 然后,在AlN微晶层上形成具有In x Ga y Al z N(0 <= x,y,z <= 1,x + y + z = 1)组成的氮化物半导体晶体层。
摘要:
A process for providing activated carbon fibers consisting of optically anisotropic components and optically isotropic components by spinning a pitch into fibers, and infusibilizing the resulting fibers, followed by an activation treatment. The pitch for spinning is prepared by melt mixing together (A) 100 parts by weight of an optically isotropic pitch having a softening point of 230.degree.-300.degree. C. obtained by heat treatment of a pitch while blowing an oxygen containing gas into the pitch, and (B) 10-50 parts by weight of an optically isotropic pitch having a softening point of 200.degree.-270.degree. C. obtained by polymerization of naphthalene in the presence of a Lewis acid catalyst. The optically isotropic pitch (B) is further characterized as having the property of being converted into an optically anisotropic pitch by the stress occurring at the time of spinning. The carbon fibers produced by spinning the spinning pitch into fibers have a double layer structure, the surface layer exhibiting optical isotropy and the center portion exhibiting optical anisotropy. The spun fibers are infusibilized, followed by carbonization and/or graphitization.
摘要:
There is disclosed a process for continuously producing a pitch-based carbon fiber felt which comprises the steps of spinning a pitch by melt blow spinning system; accumulating the spun fibers as a pitch fiber web composed of the aggregate of short fibers; continuously cross lapping the web; subsequently stabilizing the cross lapped web; carbonizing and/or activating the stabilized web; and then felting the resultant web. The above-mentioned process is capable of efficiently producing a pitch-based carbon fiber felt having uniform unit weight and excellent physical properties and well suited for use in high-performance thermal insulator, cushioning thermal insulator, filter media and adsorbent for water purification and solvent recovery, etc.
摘要:
Provided are a graphite material suitable as an electrode material for nonaqueous electrolyte secondary batteries, a carbonaceous material for battery electrodes, and secondary batteries which exhibit excellent charge-discharge cycle characteristics and excellent severe-current-load characteristics. A graphite material which has specific sizes of optically anisotropic and isotropic structures, a specific content ratio between both structures, and various orientation of crystallization; and a carbonaceous material for battery electrodes which is made using the graphite material and which exhibits a large discharge capacity and a small irreversible capacity with the severe-current-load characteristics and cycle characteristics being kept at high levels.
摘要:
A mesophase pitch-based carbon fiber for use as a material for a negative electrode of a secondary battery, and a process for producing the same. The mesophase pitch-based carbon fiber comprises a columnar core part having a texture composed of a plurality of graphite layers extending along an axial direction and extending with minute flexures in a plane perpendicular to the axis and an outer-shell part surrounding the core part. The outer-shell part has a texture composed of a laminate of a plurality of graphite layers extending along an axial direction. The graphite layers are oriented in a plane perpendicular to the axis in a fashion such that the graphite layers extend along a circumferential direction with minute flexures while gradually receding from a center of the core part. In the carbon fiber, the graphite layers composing the outer-shell part have a laminate face forming a surface of the outer-shell part, channels permitting entry and exit of lithium ions being formed between graphite layers at the laminate face.
摘要:
A negative electrode material for use in lithium-ion secondary batteries, comprising milled pitch-based graphite fibers (A) obtained by graphitization at 2400.degree. C. or higher and milled pitch-based carbon fibers (B) obtained by carbonization at 550.degree. to 1300.degree. C. In this negative electrode material, it is preferred that both the milled pitch-based graphite fibers (A) and the milled pitch-based carbon fibers (B) have an average particle size of 10 to 30 .mu.m, that the ratio of milled pitch-based carbon and graphite fibers having a particle size of 5 .mu.m or less to all the milled pitch-based carbon and graphite fibers is not greater than 10% by weight and that the milled pitch-based graphite fibers (A) and the milled pitch-based carbon fibers (B) are blended at a weight ratio (A/B) of 95/5 to 40/60. A negative electrode which has a large capacity at the time of having been stabilized, exhibits a high charge and discharge efficiency at the initial stage and is excellent in charge and discharge cycle characteristics can be provided by the blending of milled pitch-based carbon fibers with milled pitch-based graphite fibers.