Composite and manufacturing method therefor

#1. Field of the Invention

#This invention relates to a composite in which a film mainly comprising amorphous titanium oxide is formed on a surface of a base and to a manufacturing method therefor.

#2. Description of the Prior Art

#FIG. 1 is a longitudinal section illustrating an embodiment of a composite according to this invention;

#FIG. 2 schematically shows a network structure of the film 14 in FIG. 1;

#FIG. 3 schematically shows an exemplary configuration of a plasma CVD apparatus used for depositing the film 14 in FIG. 1;

#An embodiment of this invention will be described below. FIG. 1 is a longitudinal section (the film is drawn with an enlarged thickness) illustrating an embodiment of a composite according to this invention. A composite 10 is composed of a base (substrate) 12 and a film 14 deposited on the base surface. The substrate 12 is a plate made of, for example, synthetic resin or glass. The film 14 is mainly composed of amorphous titanium oxide {TiOxx>2)}.

#FIG. 2 schematicaly shows the structure of the film 14. Titanium dioxide, either crystal or amorphous, has a basic structure where Ti is positioned at the center of an octahedron and an oxygen atom is positioned at each of six apices. The basic structures are mutually connected, sharing two edges for rutile and four edges for anatase. For the crystal type, the connection is regular in a wide range, while it is irregular for the amorphous type. In the film 14, connections between the basic structures of titanium oxide (based on titanium dioxide in FIG. 2) (a Ti—O—Ti bond network) are frequently cleaved, and Ti is bound to OH to form a terminal Ti—OH bond at many of the cleavage positions. Titanium dioxide is designated as TiO2 because O is shared between the basic structures, while in the structure illustrated in FIG. 2, unshared oxygen atoms exist at the cleavage positions in the form of Ti—OH and thus TiOx is used to represent the whole composition (x>2; for example, x=2.3). A proportion of terminal Ti—OH bonds may be most suitably 5 to 30% of the whole Ti—O bonds in the connection between the basic structures.

#A method for manufacturing the composite 10 in FIG. 1 will be described. FIG. 3 shows an exemplary,configuration of a plasma CVD apparatus used for depositing the film 14. FIG. 4 is a section taken along line A—A in FIG. 3. A whole cylindrical vacuum vessel 16 is an anode. The outer surface of the vacuum vessel 16 is wrapped with a heater 18. In the vacuum vessel 16, a quartz tube 20, a cathode 22, and a quartz tube 24 are concentrically disposed in sequence. The outer quartz tube 20 is provided for ensuring insulation between the anode 16 and the cathode 22, while the inner quartz tube 24 is provided not only for preventing contamination of the anode 16 and the cathode 22 but also for supporting the substrate 12. On the central axis in the vacuum vessel 16, a material gas introducing pipe 28 is disposed in such a way that it is supported on the inner quartz tube 24 by a supporting post 30. The material gas introducing pipe 28 is electrically connected to the anode 16.