LUBRICATED STEEL SHEET

Abstract: The degreasing and oxidizing process which is necessary in the conventional process can be omitted by coating resin on the steel sheet which is used in the many machines parts of the inner color picture tube. Thereby reducing environmental problems and rust to the machine parts caused by the degreasing solution and the oil during oxidizing respectively. In addition, the lubricated steel sheet is economical to use because a few steps of the process are deleted.

Description: LUBRICATED STEEL SHEET BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricated steel sheet, more specifically, to a lubricated steel sheet which is coated with zinc and resin, which is used for a panel assembly for a color braun tube, i.e., a frame or an inner shield of machine parts for color picture tubes to make unnecessary degreasing and oxidizing processes and to reduce the time of the process and to solve environmental pollution problems by not using a degreasing solution. 2. Description of the Related Arts After a shadow mask for a color picture tubes (CPT) is assembled with a screen in a panel, leaving a space between them, it is annealed for further processes, processing and forming processes. The mask is finally formed by a press and foreign substances such as oil, contaminants and fingerprints are removed by a next step, a degreasing process. The degreasing process is to remove oil and foreign substances used in the process for forming by using original trichloroethylene solution. The formed shadow mask is fixed on a frame by welding to maintain the form thereof. For the frame to play a role of fixing the shadow mask, no changes of the form or outer size of the frame must be observed after calcinating for an assembly to be stable against heat. The frame is assembled through springs which are attached by welding on the sides of the frame. The frame and the degreased mask are electrically welded to produce a mask assembly and oxidized to prevent rust from forming. The oxidizing process is the process which forms an oxidized film of iron oxide(Fe 3 O ) on the surface of the mask to prevent from possible oxidation and diffused reflection such as thermal decalescence and exposure light beam. A machine part of a thin metal tube, i.e., an inner shield is attached in the color picture tube to control the mobility of electron beams by an earth magnetism and to decrease the influence of the earth magnetism. The beam mobility of a 16 inch color picture tube is 60 μ without an inner shield and 25 μ with an inner shield. The mask assembly on which the machine parts such as the frame and the inner shield are attached by spring frame welding and mask frame welding, is assembled with the panel and calcinating is performed. When the mask-panel assembly is calcinated at a temperature of 450 ° C for 2 hours, the stress of the mask and the panel is stabilized so as not to affect the metal and the glass from heat. The panel-mask is separated after cooling. To remove the pollutants on the panel such as dust and grease, the assembly is washed with acid solution and rinsed with deionized water. Trichloroethylene degreasing solution used in the degreasing process in the above process is colorless and has an odor of chloroform. The liquid phase thereof is harmless, however, the gas state thereof has toxicity. The allowable concentration thereof is 100 ppm. It is anesthetic, nonflammable and insoluble in water. Polyvinyl chloride gloves and protection glasses must be worn because of the danger of trichloroethylene contacting the skin or eyes of human beings and trichloroethylene has the possibility of igniting with oxygen or air by high energy source. In addition, drowsiness headaches, dizziness, unconsciousness or fatal symptoms can occur when a high concentration of trichloroethylene vapor is inhaled. Therefore, an ventilation apparatus is necessary since trichloroethylene is heavier than air and does not disperse rapidly in a closed container or non ventilated room. SUMMARY OF THE INVENTION Accordingly, the present invention is intended to overcome the above- described disadvantage of conventional arts and to provide the process for the machine part which reduce loss of the process by deleting the degreasing and oxidizing process and solve the environmental problem by not using the degreasing solution. An embodiment of the present invention provides a process for a machine part for a color picture tube assembly comprising the steps of coating resin on a steel of machine parts, forming the steel coated with said resin, oxidizing, calcinating and baking the steel. The process further comprises the step of plating with chromate on the steel before coating. Another embodiment of the present invention provides a machine part for a color picture tube assembly comprising of steel and a resin layer coated on the steel. the maching part for a color picture tube is preferred to further comprise a chromate layer between the steel and resin layer. Another embodiment of the present invention provides a process for a machine part for a color picture tube assembly comprising the steps of plating zinc on steel of machine parts, coating resin on the steel plated with zinc, forming the steel coated with the zinc and resin and calcinating and baking the steel. The process is preferred to further comprise the step of plating with chromate on the steel after Plating zinc on the steel. Another embodiment of the present invention provides a machine part for a color picture tube assembly comprising of steel, a zinc layer plated on the steel and a resin layer coated on the zinc layer. The machine part for a color picture tube is preferred to further comprise a chromate layer between the zinc layer and resin layer. Another embodiment of the present invention provides a lubricated steel sheet comprising of steel and a resin layer coated on the steel. The lubericated steel sheet is preferred to further comprise a chromate layer between the steel and resin layer. The lubricated steel sheet is preferred to use for manufacturing of a frame or inner shield for color picture tubes. Japanese Patent 89-1522044 discloses a process for a color picture tube solving the problem of the trichloroethylene solution. After Ni and Cr are plated on the shadowmask, frame and inner shield with the thickness of 0.5 μ to 1.0 μ , The shadowmask and the frame are welded to produce a maskframe, and the frame and a holder are attached, and the maskframe and a panel are assembled. Then, the fluorescent screen is formed, the oxidized film of metal component is formed through sealing, exhaust and aging processes. Therefore, the surface of the metal formed by a thermal process without an oxidizing process is thinner and harder than a conventional oxidized film. DETAILED DESCRIPTION OF THE EMBODIMENTS Although the invention has been described with reference to a preferred embodiment it is to be understood that the invention is not limited to the preferred embodiment as herein described. EXAMPLE Zinc and chromate was coated on a steel sheet and then resin was coated thereon. The steel sheet was mold processed in the press by calcinating in nitrogen air and baking to produce a fixed frame and inner shield. COMPARATIVE EXAMPLE A cold rolled steel sheet was oxidized at a high temperature in methane gas and air atmosphere and was calcinated, baked and mold processed in the press to produce a frame and inner shield for color picture tubes with a fixed size. The mechanical properties of a steel sheet coated resin is excellent than that of the conventional steel sheet when they are used as a machine part. The steel sheet coated resin makes the total process simpler because omission of degreasing and oxidizing process.

Claims: What is claimed is: 1. A process for a machine part for a color picture tube assembly comprising the steps of: coating resin on a steel of machine parts; forming said steel coated with said resin; oxidizing said steel; and calcinating previously and baking said steel. 2. The process for a machine part for a color picture tube assembly according to claim 1 , further comprising the step of plating with chromate on said steel before coating. 3. A machine part for a color picture tube assembly comprising: steel; and a resin layer coated on said steel. 4. The machine part for a color picture tube assembly according to claim 3, further comprising chhromate layer between said steel and resin layer. 5. A process for a machine part for a color picture tube assembly comprising the steps of: plating zinc on a steel of machine parts; coating resin on said steel plated with zinc forming said steel coated with said zinc and resin; and calcinating previously and baking said steel. 6. The process for a machine part for a color picture tube assembly according to claim 5, further comprising the step of plating with chromate on said steel after plating zinc on said steel. 7. A machine part for a color picture tube assembly comprising: steel; a zinc layer plated on said steel; and a resin layer coated on said zinc layer. 8. The component for the start of work for a color picture tube assembly according to claim 7, further comprising chromate layer between said zinc layer and resin layer. 9. A lubricated steel sheet comprising: a steel; and a resin layer coated on said steel. 10. The lubricated steel sheet according to claim 9, further comprising chromate layer between said steel and resin layer. 11. The lubricated steel sheet according to claim 9, wherein said lubricated steel sheet is used for manufacturing of a frame or inner shield for color picture tubes.

Inventors: KIM MYUNG SUB, KOO HAENG MIN, KIM, MYUNG, SUB, KOO, HAENG, MIN
Applicants: KIM MYUNG SUB, KOO HAENG MIN, SAMSUNG DISPLAY DEVICES CO LTD, KIM, MYUNG, SUB, KOO, HAENG, MIN, SAMSUNG DISPLAY DEVICES CO., LTD.
Application year: 1997
Main classification: C23C26
IPC codes: C23C8, C23C26, C23C28, H01J9, H01J29, H01J31