Matsushita Electronics Corporation

Masao Hayashi

Tsuyoshi Fujii

Takashi Hayashi

Go Minami

Kuniaki Matsunaga

Kazuya Fushimoto

A body of a shadow mask having a skirt portion around the body, wherein cut parts are formed in the skirt portion in the vicinity of corner portions and center portions of the short sides and the length of the skirt portion in the corner portions is longer than the length of the skirt portion in the center portions of the short sides. This enables residual distortion generated during welding with a mask frame and a thermal expansion generated later to be absorbed at the skirt portion, thus restraining the deformation generated by heating a curved surface of the shadow mask. As a result, it is possible to realize cost reduction and to improve productivity in manufacturing a color picture tube without deteriorating the color purity in the color picture tube by preventing the thermal deformation of the curved surface of a shadow mask during manufacturing processes of the color picture tube without a dummy baking process.

Shadow mask with skirt

In pressing and molding a shadow mask or the like, press-molding oil containing alkyl carbonate shown in the following Chemical Formula as an active ingredient is coated on a press mold. After pressing and molding a metallic material with the press mold, the press-molding oil is washed and removed with warm water. Alternatively, the oil is dried or thermally decomposed. As a result, less than about 10 .mu.g/cm.sup.2 oil is left as residue on the product. ##STR1## where a and b are an integer from one to six; x and y are an integer from 0 to 30; R.sup.1 and R.sup.2 are an alkyl group, cycloalkyl group, alkylphenyl group, benzyl group or alkylbenzyl group having from one to thirty carbon atoms and straight or branched alkyl chains.

Press molding oil and method of manufacturing press-molded products by

Press-molding oil and method of manufacturing press-molded products by

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Shiga, Japan

Masao Hayashi