Towa Corporation

Japan Fine Ceramics Center

Japan Fine Chemicals Center

Yoshinori Noguchi

Keiji Maeda

Satoshi Kitaoka

Takaki Kuno

Naoki Kawashima

Seiichi Suda

Masato Yoshiya

Kazuhiko Bandoh

Norio Yamaguchi

An upper die has a cavity member constituting an inner bottom surface of a cavity, and a surrounding member. The cavity member is formed of a low adhesion material in accordance with the present invention, and includes a body portion and a surface layer formed on an undersurface of the body portion exposed to a fluid resin. The body portion is formed of a first material of 3YSZ and a second material of ZrN that are mixed at a predetermined ratio. The surface layer is formed of YOhaving a low adhesion property with respect to a set resin, and has a thermal expansion coefficient smaller than that of the body portion. By bonding the body portion and the surface layer at a high temperature and then cooling them down, compressive residual stress is caused in the surface layer due to a difference in the thermal expansion coefficients thereof, and the compressive residual stress is present in the surface layer.

Low-adhesion material, resin molding die, and soil resistant material

A low-adhesion material containing a rare-earth element is formed as a layer or a film on a mold surface of a mold for molding a resin. A main component of the low-adhesion material is a rare-earth compound, and YOis used as an example. A content of the rare-earth compound in the low-adhesion material is not less than 40 percent by volume. Thereby, a mold for molding a resin having excellent releasability can be obtained.

Low-adhesion material, mold for molding resin using the same and contaminant adhesion preventing material

A conductive porous material includes a matrix having a sintered compact of an oxide, a communicating opening formed in the matrix, having a small diameter and being permeable to gas and impermeable to substance other than gas, and a conductive layer provided on an internal wall of the communicating opening and receiving a current to generate heat. As conductive material is used, an organic substance adheres on the internal wall of communicating opening. To address this, conductive layer is caused to generate heat to decompose and thus remove the organic substance and thus prevent the communicating opening from clogging.

Conductive porous material, resin molding die employing the same, and method of preparing conductive porous material

A mold surface of an upper mold with which a fluid resin comes into contact has an oxide therein. The oxide contains a metal cation and an ion. Field strength is calculated based on a valence of the metal cation and ionic radius of the ion. Based on predetermined relationship established between a value of the field strength and adhesion strength between a cured resin and the mold surface, releasability between the cured resin and the mold surface is evaluated. Thereby, a method of evaluating releasability between the cured resin and the mold surface is established. With this evaluation method, a material with high releasability can readily be provided. Further, if the material with high releasability is used for the mold surface of the upper mold, a mold for molding a resin having excellent releasability can be obtained.

Method of evaluating adhesion property, low-adhesion material, and mold for molding resin

A resin mold material includes one-dimensional communicating holes extending substantially linearly from a mold surface and having diameters from 1 nm to less than 10 &#x3bc;m; a surface layer including the mold surface and the one-dimensional communicating holes; a support layer covering a back of the surface layer; and three-dimensional communicating holes communicating with the one-dimensional communicating holes in the support layer and having diameters larger than those of the one-dimensional communicating holes. Accordingly, a liquid resin is unlikely to enter the one-dimensional communicating holes, thereby reducing a contact area of the mold surface and the liquid resin, i.e., the mold surface is repellant to the liquid resin. Gas in a mold cavity bounded by the mold surface is discharged through the one-dimensional and three-dimensional communicating holes sequentially. Consequently, a release property of a molded product from the mold surface is improved and generation of voids is suppressed.

Growing community of inventors

Kyoto, Japan

Yoshinori Noguchi