Abstract: A production method for a lead-containing hot-galvanized chromated steel sheet with excellent resistance to blackening and white rust formation comprises: (a) plating a steel sheet in a hot-galvanizing bath containing 0.05-0.3 wt. % lead and 0.1-0.3 wt. % aluminum; (b) coating this with a chromating solution containing chromium (VI) ions, chromium (III) ions and nitrate ions in which the Cr(III)/Cr(VI) molar ratio is 1/9-1/1 and the nitrate ion to total chromium ion molar ratio is 0.1-1.6; and (c) without washing with water, drying the sheet at 40-250 deg. C., to form a 5-50 mg/m integral 2 (in terms of chromium) chromate film.

Abstract: In order to manufacture a chromate-coated lead-containing galvanized steel sheet having beautiful spangles and excellent anti-black patina and anti-white rust properties without relying upon any flushing treatment with Ni, etc., a lead-containing galvanized steel sheet obtained by plating in a galvanizing bath containing appropriate amounts of Pb and Al, and having beautiful spangles is coated with a chromate coating solution containing trivalent and hexavalent chromium ions in a molar ratio of 1/9 to 1/1, and nitrate ions in a molar ratio of 0.1 to 1.6 to the total of the chromium ions, preferably after treatment with an aqueous alkali solution having a pH of 9 or above, and washing with water, and the sheet is dried at an appropriate sheet temperature without being washed with water, whereby a chromate film having a coating weight of 5 to 50 mg/m2 is formed thereon.

Abstract: In an image reader comprising a lower frame disposed below a document path, an upper frame pivotally fitted to the lower frame above the document path via a fulcrum shaft, an optical unit disposed above the document path; a motor for driving a document feeder, and/or the rotation transmission mechanism thereof being mounted on the upper frame, the optical unit has a unit frame as a separate member from the upper frame, and the unit frame and the upper frame are independently pivotally supported by a common fulcrum shaft supported by the lower frame in a non-contact state with each other, and independently engaged at their respective close positions via stopper provided on the lower frame.

Abstract: The invention relates to a thermosetting coating composition for precoated steel sheets which are required to have high hardness, good workability and stain resistance, to a precoated steel sheet having a film of the coating composition, and to a method for producing such precoated steel sheets.

Abstract: This invention provides an organic composite coated steel sheet comprising, as the base, a zinc or zinc alloy coated steel sheet, which can be used in automobile bodies and electric appliances. The coated steel sheet has excellent press formability with oil, while having excellent perforation corrosion resistance and excellent corrosion resistance in a rust-contaminated environment. The coated steel sheet comprises a zinc or zinc alloy plated steel sheet having, on its surface, a chromate layer and an organic film formed in that order, in which the organic film has a thickness of from 0.1 to 3.0 .mu.

Abstract: Method for producing a galvannealed steel sheet wherein a slab consisting essentially of C in an amount of 0.004 wt. % or less, N in an amount of 0.004 wt. % or less, Ti in an amount of 0.01 to 0.15 wt %, Si in an amount of 0.05 wt. % or less, Mn in an amount up to 2.5 wt. %, P in an amount up to 0.1 wt. %, S in an amount of 0.015 wt. % or less, sol. Al in an amount of 0.02 to 0.1 wt. % and the balance being Fe, is soaked for at least 30 minutes at a specified temperature (range). The soaked slab is hot rolled to produce a hot-rolled steel sheet which is coiled at a temperature of 500 to 700.degree. C. The coiled hot-rolled steel sheet is cold rolled at a reduction ratio of 60% or more to produce a cold-rolled steel sheet which is annealed at a temperature of from recrystallization temperature to Ac3 transformation temperature. Galvanizing the annealed cold-rolled steel sheet and then galvannealing at a temperature of 450 to 600.degree. C.

Abstract: A zinciferous plated steel sheet which comprises a steel sheet, at least one zinciferous plating layer formed on at least one surface of the steel sheet, and an Fe--Ni--O film as an uppermost layer formed on the zinciferous plating layer. The total quantity of metallic elements in the Fe--Ni--O film is within a range of from 10 to 1,500 mg/m.sup.2, and the oxygen content in the Fe--Ni--O film is within a range of from 0.5 to under 30 wt. %. The ratio of the iron content (g/l) relative to the total quantity of the iron content (g/l) and the nickel content (g/l) in the Fe--Ni--O film is preferably within a range of from over 0 to under 1.0.

Abstract: A method for manufacturing a zinciferous plated steel sheet, comprises: forming a zinciferous plating layer on a steel sheet; and forming an Fe--Ni--O film on the zinciferous plating layer. The Fe--Ni--O film is formed by carrying out electrolysis with the steel sheet as a cathode in an aqueous solution, dipping the steel sheet in an aqueous solution, or spraying a mist on a surface of the zinciferous plating layer.

Abstract: Disclosed is an organic-composite coated steel plate comprising a steel plate provided with a plated layer made of zinc or a zinc-base alloy, a chromate-treated layer formed on said plated layer with a deposition amount ranging from 1 to 200 g/m.sup.2 in terms of metal chromium, and a resin film formed on said chromate-treated layer with a thickness ranging from 0.1 to 5 .mu.m, wherein said resin film has (A) selected from the group consisting of a reaction product (I) between an ethylene-series ionomer resin and an epoxy-group containing compound, a mixture of an ethylene-series ionomer resin and an epoxy emulsion, a mixture of the reaction product (I) and an epoxy emulsion, and a mixture of the reaction product (I), an ethylene-series ionomer resin and an epoxy emulsion, in an amount of 60 to 99% by weight, and (B) fine silica particles in an amount of 1 to 40% by weight.

Abstract: An organic composite coated steel sheet having an excellent corrosion resistance in a rust-contaminated environment. The sheet contains a chromate film on a zinc or zinc alloy plated sheet and an organic resin film on the chromate film. The resin film has a thickness of 0.2-2.0 microns. The resin film contains (a) a base resin obtained by adding at least one basic nitrogen atom and at least two primary hydroxyl groups to the ends of molecules of an epoxy resin, (b) a polyfunctional polyisocyanate compound having at least six isocyanate groups per molecule, and (c) a rust-preventing additive of a sparingly soluble chromate or a mixture of silica and a sparingly soluble chromate.

Abstract: To provide a high-speed paper-feeding device for feeding slips or papers from the hopper by using a pick roller, featuring reduced misoperation, reduced noise, a higher paper-feeding speed and compactness. In the high-speed paper-feeding device, the bouncing motion of the pick roller that may take place at the beginning of the paper-feeding operation is suppressed by using a buffer device, the end portions only of the slips or the papers are pushed up/restored by a push-up device, that moves the arm up and down being driven by a solenoid that is provided at the bottom of the hopper, in order to reduce the burden for moving the hopper up and down born by the motor and the rack-and-pinion mechanism. Besides, the motion of the pick roller is detected at a moment when the rear end of the slip separates away from the pick roller to control the continuous feeding of the papers while eliminating dead time between the papers that are fed and enabling the papers to be continuously fed at high speed.

Abstract: A black steel sheet having a sufficiently small coating thickness to allow the welding of the steel sheet, and yet exhibiting an excellently black surface. It is a steel sheet having a surface plated with zinc or a zinc alloy, and carrying a chromate film formed on its plated surface, and a black film formed on the chromate film from a composition comprising specific proportions of a thermosetting resin and a black dye, which are both soluble in an organic solvent, and having a sufficiently small thickness. The composition may further contain a solid lubricant, or a granular rust-inhibitive pigment, or both.

Abstract: A colored steel sheet having a coating thickness which is sufficiently small to permit welding therethrough, and yet exhibiting an excellently colored and lustrous surface. It is a steel sheet having a surface plated with zinc or a zinc alloy, and carrying a chromate film formed on its plated surface, and a colored film formed on the chromate film from a composition comprising specific proportions of a thermosetting resin and a dye, which are both soluble in an organic solvent. The composition may further contain a solid lubricant, or a granular rust-inhibitive pigment, or both. The colored film has a specific range of thickness, and a color other than black.

Abstract: A black steel sheet having a sufficiently small coating thickness to allow the welding of the steel sheet, and yet exhibiting an excellently black surface, but also having high corrosion resistance, adhesive strength and formability. It is a steel sheet having a surface plated with zinc or zinc alloy, and carrying a chromate film formed on its plated surface, and a black film formed on the chromate film from a composition comprising specific proportions of a water-soluble or water-dispersible thermosetting resin and a water-soluble black dye, and having a sufficiently small thickness. The composition may further contain a solid lubricant, or a granular rust-inhibitive pigment, or both.

Abstract: A colored steel sheet having a coating thickness which is sufficiently small to permit welding therethrough, and yet exhibiting an excellent colored and lustrous surface. It is a steel sheet having a surface plated with zinc or zinc alloy, and carrying a chromate film formed on its plated surface, and a colored film formed on the chromate film from a composition comprising specific proportions of a water-soluble or water-dispersible thermosetting resin and a water-soluble dye. The composition may further contain a solid lubricant, or a granular rust-inhibitive pigment, or both. The colored film has a specific range of thickness, and a color other than a black.

Abstract: A zinc-plated steel sheet having a resin coating film formed on the surface is obtained by forming a chromate treating layer on the surface of a base steel sheet plated with zinc or a zinc alloy, said chromate treating layer being deposited in an amount of 1 to 200 mg/m.sup.2 in terms of metal chromium, followed by forming a resin coating film on the chromate treating layer in a thickness of 0.1 to 5 .mu.m, said resin coating film being based on a composite resin material including a resin composition and at most 50% by weight of silica, said resin composition containing an ethylene-based ionomer resin and a silane compound having in the molecule a single silicon atom and 2 to 4 silyl ether bonds and/or its condensate.

Abstract: An organic composite coated steel sheet having a high cosmetic corrosion resistance and excellent image clarity which is desired on, for example, the outside of an outer plate forming an automobile body. The steel sheet has a chromate layer formed on the surface of a zinc or a zinc alloy plate steel sheet, and containing a specific weight of chromium, and an organic resin film formed on the chromate layer from a mixture in specific proportions of a blocked urethane-modified epoxy resin and a rust-preventing additive, and having a thickness of 0.2 to 2 microns. The resin is a mixture in specific proportions of a modified epoxy resin (A) which consists of an epoxy resin and a polyfunctional amine, and may further contain a monoisocyanate, or phosphoric acid, and a blocked urethane (B) which consists of a high molecular weight polyol having a molecular weight of 400 or more, a polyisocyanate and a blocking agent. A process for manufacturing the strip is also disclosed.

Abstract: A zinciferous plated steel sheet excellent in press-formability and corrosion resistance, which comprises: a steel sheet, a zinciferous plating layer formed on at least one surface of the steel sheet, a chromate film formed on the zinciferous plating layer, and a resin film formed on the chromate film. The resin film comprises a solvent-base thermosetting resin, a solid internal lubricant and a rust-preventive pigment. The solvent-base thermosetting resin comprises: (A) urethane prepolymer containing a hydroxyl group, and (B) at least one of a block polyisocyanate compound and an amino resin as a curing agent. The urethane prepolymer containing a hydroxyl group comprises: (a) at least one of polyether polyol, polyester polyol and polyether-polyester polyol, (b) an isocyanate compound, and (c) dihydric alcohol.

Abstract: A method for continuously tin-electroplating a metal strip, which comprises the steps of: causing a DC electric current to flow between a metal strip and an anode arranged adjacent to the metal strip while passing the metal strip at a travelling speed of at least 1 m/minute through an acidic tin-electroplating solution containing tin ions and an organic acid within a range of from 4.8 to 98 g/l as converted into sulfuric acid, to form a tin-electroplating layer on at least one surface of the metal strip; and applying an ultrasonic vibration, emitted from at least one ultrasonic vibrator and having an intensity within a range of from 0.01 to 1,000 W/100 cm.sup.2 and a frequency within a range of from 25 to 55 kHz, to the acidic tin-electroplating solution between the metal strip and the anode, thereby removing a diffusion layer of tin ions existing in the acidic tin-electroplating solution adjacent to the surface of the metal strip.

Abstract: A steel sheet plated with zinc or a zinc alloy carries a chromate film formed on each side thereof and having a coating weight of 1 to 200 mg/m.sup.2 in terms of metallic chromium, and a black film formed at least on the chromate film on one side thereof. The black film contains 100 parts by weight of a thermosetting resin which is soluble in an organic solvent, 1 to 200 parts by weight of a black dye which is also soluble in an organic solvent, and 1 to 100 parts by weight of organic resin particles. It may further contain 1 to 100 parts by weight of fine inorganic particles, or a solid lubricant, or both. The black film has a thickness of 0.3 to 5.0 microns which is sufficiently small to permit the welding of the sheet, and yet has an excellently black surface. The organic resin particles, etc., which are used as a matting agent, give the film a surface of low gloss which resists visible staining by fingerprints.