Abstract: A first frame includes a bottom portion, an inclined portion, a joint portion and a lateral portion for supporting a shadow mask. Between the lateral portion and the joint portion, a space is provided except where the lateral portion and the joint portion are welded. The joint portion is inclined with respect to the lateral portion such that the space enlarges with an increase in the distance from an edge of the lateral portion on the side of supporting the shadow mask. With this configuration, foreign substances can be removed from between the lateral portion and the joint portion in the process of cleaning the first frame, making it possible to both suppress the deterioration of high-voltage withstand capabilities of a color cathode ray tube and prevent the poor welding of the first frame.

Abstract: To provide a method for manufacturing a color selection electrode structure easily capable of measuring a tension amount of the color selection electrode in the process for manufacturing the color selection electrode structure and a color cathode ray tube using the color selection electrode structure. The color selection electrode is stretched with tension applied in the direction of the shorter axis thereof, and welded and fixed onto the top face that is curved inwardly in the direction of the longer axis of the longer side members. Thereafter, the weight is placed on the color selection electrode so as to allow the color selection electrode to deflect by the load due to the mass of the weight. The deflection amount of the color selection electrode may be measured by using a laser displacement meter and the measured deflection amount of the measured color selection electrode is converted into the tension amount by the correlation graph.

Abstract: A first frame includes a bottom portion, an inclined portion, a joint portion and a lateral portion for supporting a shadow mask. Between the lateral portion and the joint portion, a space is provided except where the lateral portion and the joint portion are welded. The joint portion is inclined with respect to the lateral portion such that the space enlarges with an increase in the distance from an edge of the lateral portion on the side of supporting the shadow mask. With this configuration, foreign substances can be removed from between the lateral portion and the joint portion in the process of cleaning the first frame, making it possible to both suppress the deterioration of high-voltage withstand capabilities of a color cathode ray tube and prevent the poor welding of the first frame.

Abstract: A color cathode ray tube has a color selection electrode structure made by stretching and welding a color selection electrode having a plurality of apertures to a frame while applying tension in the minor axis direction. A non-perforated region gradually becomes wider from a center portion to both end portions in the minor axis direction. Thus, sufficient tension is applied in the peripheral portion of the perforated region in the major axis direction of the color selection electrode, so that vibrations do not occur easily and the color selection electrode does not warp. Therefore, a color cathode ray tube with excellent color purity can be obtained.

Abstract: To provide a method for manufacturing a color selection electrode structure easily capable of measuring a tension amount of the color selection electrode in the process for manufacturing the color selection electrode structure and a color cathode ray tube using the color selection electrode structure. The color selection electrode is stretched with tension applied in the direction of the shorter axis thereof, and welded and fixed onto the top face that is curved inwardly in the direction of the longer axis of the longer side members. Thereafter, the weight is placed on the color selection electrode so as to allow the color selection electrode to deflect by the load due to the mass of the weight. The deflection amount of the color selection electrode may be measured by using a laser displacement meter and the measured deflection amount of the measured color selection electrode is converted into the tension amount by the correlation graph.

Abstract: 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.

Abstract: 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.