Hoya Corporation

Yasuo Kusumi

Shinichiro Hirota

Ken Uno

Hiroyuki Sawada

Takuo Fujino

The present invention relates to a mold for producing glass articles comprising a glass-made mold base, an intermediate layer formed by a silicon carbide and/or silicon nitride film, and an uppermost layer formed by a carbon film. Since the mold for producing glass articles exhibits an excellent bonding between the glass-made mold base and the uppermost layer formed by the carbon film, peeling of the uppermost layer can be prevented. Therefore, the function of the uppermost layer as an adhesion-prevention layer against the glass to be molded can be exhibited for a long time, causing an economic advantage since the life of the mold can be lengthened. In addition, since the maximum surface roughness of the working surface of the mold can be reduced and the surface shape accuracy can be maintained, a molded glass article exhibits excellent surface accuracy without optical defects.

Mold for producing glass articles

According to the present process for producing a glass mold, a base for a glass mold to be produced is subjected to a sputtering treatment using an inert gas and graphite as a target at a mold base temperature of 250.degree.-450.degree. C., and thereby is formed on the mold base a hard carbon film having excellent adhesion to the mold base and excellent hardness and being unliable to cause fusion bonding to a molded glass article produced. Accordingly, the glass mold produced according to the present process has excellent durability and excellent glass releasability.

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Akishima, Japan

Yasuo Kusumi