Abstract: A first aspect of the present invention is carbon fiber wherein the surface of a monofilament has a center line average roughness Ra of 6.0 nm or more and 13 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. A second aspect of the present invention is carbon fiber precursor acrylic fiber wherein the surface of a monofilament has a center line average roughness Ra of 18 nm or more and 27 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. The carbon fiber according to the first aspect is obtained by stabilizing and carbonizing under specific conditions the carbon fiber precursor acrylic fiber according to the second aspect.

Abstract: [Object] To provide a freeze-drying apparatus and a freeze-drying method, which are capable of increasing a drying efficiency of frozen particles. [Solving Means] The freeze-drying apparatus 100 includes a freezing chamber 10 into which a raw material fluid F is injected. During the injection of the raw material fluid F, after the injection of the raw material fluid F, or for a time period covering the start to the termination of the injection of the raw material fluid F, a shelf 16 is vibrated in a horizontal direction due to an actuation of vibration generators 31. With this, the frozen particles deposited on the shelf 16 are evenly diffused on the shelf 16 in such a manner that a deposition thickness thereof becomes smaller or a single layer thereof is formed. With this, a freezing efficiency and the drying efficiency of individual particles are promoted.

Abstract: A vacuum freeze-drying apparatus capable of rapid drying is provided. A cold trap for drying, which is arranged inside a drying chamber, is set to a low temperature of ?70 degrees Celsius or below, and heat is supplied to frozen particles on a conveyor belt to a degree such that the frozen particles do not melt. The amount of the liquid component evaporating from the frozen particles increases, and the amount of the liquid component entering the frozen particles decreases so that the time for drying the frozen particles is shortened.

Abstract: [Object] To provide a freeze-drying apparatus and a freeze-drying method, which are capable of increasing a drying efficiency of frozen particles. [Solving Means] The freeze-drying apparatus 100 includes a freezing chamber 10 into which a raw material fluid F is injected. During the injection of the raw material fluid F, after the injection of the raw material fluid F, or for a time period covering the start to the termination of the injection of the raw material fluid F, a shelf 16 is vibrated in a horizontal direction due to an actuation of vibration generators 31. With this, the frozen particles deposited on the shelf 16 are evenly diffused on the shelf 16 in such a manner that a deposition thickness thereof becomes smaller or a single layer thereof is formed. With this, a freezing efficiency and the drying efficiency of individual particles are promoted.

Abstract: [Object] To provide a freeze-drying apparatus capable of achieving an increase of a processing capacity without causing a variation of a particle diameter. [Solving Means] A freeze-drying apparatus 100 according to an embodiment of the present invention includes: a freezing chamber 10 forming a vacuum chamber; and an injector 25. The injector 25 includes a tube member 29 provided to the vacuum chamber, and a nozzle 9 including a plurality of injection holes 92 open to an inside of the tube member 29. The injector 25 injects a raw material fluid F, which is fed to the tube member 29, from the nozzle 9 into the vacuum chamber. The respective injection holes 92 are each formed so as to be open to the inside of the tube member 29, and hence the raw material fluid F is injected through the respective injection holes 92 at the same injection pressure. With this, it is possible to achieve the increase of the processing capacity without causing the variation of the particle diameter.

Abstract: [Object] To provide a freeze-drying apparatus and a freeze-drying method, which are capable of increasing a collection rate of a raw material without a need for providing a member such as a baffle plate or the like. [Solving Means] The freeze-drying apparatus 100 includes: a container 4 to store a raw material fluid F; a freezing chamber 10 being a vacuum chamber; a vacuum pump 1 to exhaust the freezing chamber 10; and an injection mechanism 25 to inject the raw material fluid F stored in the container 4 into the freezing chamber 10. The cold trap 20 is arranged within the freezing chamber 10, and hence a phenomenon that the raw material is discharged to the outside of the vacuum chamber together with a vapor as in the past can be prevented. With this, the collection rate of the raw material can be increased. Further, it becomes unnecessary to provide the baffle plate or the like for preventing the phenomenon in vicinity of an exhaust port of the vacuum chamber.

Abstract: A vacuum freeze-drying apparatus capable of rapid drying is provided. A cold trap for drying, which is arranged inside a drying chamber, is set to a low temperature of ?70 degrees Celsius or below, and heat is supplied to frozen particles on a conveyor belt to a degree such that the frozen particles do not melt. The amount of the liquid component evaporating from the frozen particles increases, and the amount of the liquid component entering the frozen particles decreases so that the time for drying the frozen particles is shortened.

Abstract: A prepreg for a printed wiring board characterized with use of a brominated epoxy resin, possessing a peak intensity of infrared absorption spectrum at 2100 to 2300 cm?1, which is 5% or lower than that of a benzene ring carbon-carbon double bond at 1600 cm?1 as measured with an infrared absorption spectrometer as well as having an inflection point between 120 and 150° C. in the cured product of said brominated epoxy resin as measured by means of a differential scanning calorimeter. The prepreg for the printed wiring board is superior in hygroscopicity, heat resistance, and desmear capability as a printed wiring board material and can be used to manufacture a copper-clad laminate board.