Nippon Steel Corporation

Other

Sony Corporation

Mitsui Chemicals, Inc.

Mitsui Petrochemical Industries, Ltd.

Ryoichi Yoshihara

Ryousuke Wake

Hiroji Niimi

Takashi Hiraoka

Yoshihiro Kaneda

Yasuo Sato

Takeshi Harada

Hiroshi Sakurai

Katsuhiro Minamida

Hiroaki Kato

Teruo Takeuchi

Takahide Shimazu

Kango Sakai

Keisuke Fukumizu

Yasuhiko Miura

Tatsuo Amaike

Tokitsugu Shirakawa

Teruyoshi Hiraoka

The present invention provides a surface treated steel sheet for electronic components which does not include lead, which is a hazardous substance with environmental impact, and, in particular, satisfies the solder wettability after retort treatment, a rust-proof property and a whisker-proof property simultaneously. More specifically, the present invention is a surface treated steel sheet with less environmental impact for electronic components excellent in solder wettability, a rust-proof property and a whisker-proof property and having an Sn&mdash;Zn alloy layer which is formed by plating Sn and Zn on a steel sheet or a Ni plated steel sheet and then applying thermal diffusion treatment, or by plating Sn&mdash;Zn alloy on a steel sheet or a Ni plated steel sheet, characterized in that the amount of said Sn&mdash;Zn alloy layer is not less than 3 g/m , the Zn/Sn ratio (in weight ratio) is 0.01 to 10, more preferably 0.01 to 0.1, and an inorganic film mainly composed of magnesium phosphate is formed in the amount of 1 to 100 mg/m in terms of the amount of P&plus;Mg on said Sn&mdash;Zn alloy layer.

Surface treated steel sheet with less environmental impact for electronic components, excellent in solder wettability, a rust-proof property and a whisker-proof property

A novel aqueous resin composition for use as a sealer is provided, including an aqueous resin as a major component, and a viscosity modifier adjusting the viscosity of the aqueous resin composition to a value ranging from 5,000 to 100,000 mPa&middot;s, the aqueous resin being an aqueous emulsion polyolefin resin which comprises a polyolefin not containing chlorine as a constituent element while exhibiting a viscosity of 1,000 mPa&middot;s or higher in a water-dispersed state having a solid resin content of 20% to 40% by weight.

Aqueous resin composition for use as a sealer

A method of producing a resin-coated steel sheet for drawn-and-ironed cans. The resin-coated steel sheet has a steel sheet with a tin-coat on each side and a resin layer of a first crystalline thermoplastic polyester resin on one of the tin-coats and a second non-crystalline thermoplastic polyester resin on the first crystalline thermoplastic polyester resin. The first crystalline thermoplastic polyester resin has an alloying ratio of: 50.ltoreq.alloying ratio&lt;100. The second non-crystalline thermoplastic polyester resin has an alloying ratio of 0&lt;alloying ratio&lt;50. The method includes thermal fusion of a mixture of 95-5 percent by weight of a crystalline polyester resin and 5-95 percent of a non-crystalline polyester resin to produce the first crystalline thermoplastic polyester resin and the second non-crystalline thermoplastic polyester resin. The first crystalline thermoplastic polyester resin and the second non-crystalline thermoplastic polyester resin are coated onto the tin-coated steel sheet using two-layer extrusion T-die and then cooled quickly.

Method for manufacturing a resin-coated steel sheet for drawn-and-ironed

A 0.1 to 0.5 mm-thick plated steel sheet having high coercive force and magnetic flux density is provided by hot rolling a slab comprising by weight carbon: 0.01 to 0.09%, silicon: not more than 1.0%, phosphorus: not more than 0.3%, manganese: not more than 1.5%, sulfur: not more than 0.04%, aluminum: not more than 1.0%, and nitrogen: not more than 0.01% with the balance consisting of iron and unavoidable impurities, cold rolling the hot rolled sheet, annealing the cold rolled sheet to prepare a steel sheet having an average grain diameter of 3 to 15 .mu.m, temper rolling the steel sheet with a reduction ratio of not more than 3%, and plating the temper rolled sheet with chromium or nickel. This enables the provision of a magnetic shielding material having no significant drift and very good electron beam landing properties.

Magnetic shielding material for television cathode-ray tube and process

A resin-coated steel sheet for drawn-and-ironed cans and a method of producing the resin-coated steel sheet. The resin-coated steel sheet has a steel sheet with a tin-coat on each side and a resin layer of a first crystalline thermoplastic polyester resin on one of the tin-coats and a second non-crystalline thermoplastic polyester resin on the first crystalline thermoplastic polyester resin. The first crystalline thermoplastic polyester resin has an alloying ratio of: 50.ltoreq.alloying ratio &lt;100. The second non-crystalline thermoplastic polyester resin has an alloying ratio of 0&lt;alloying ratio &lt;50. The method includes thermal fusion of a mixture of 95-5 percent by weight of a crystalline polyester resin and 5-95 percent of a non-crystalline polyester resin to produce the first crystalline thermoplastic polyester resin and the second non-crystalline thermoplastic polyester resin. The first crystalline thermoplastic polyester resin and the second non-crystalline thermoplastic polyester resin are coated onto the tin-coated steel sheet using two-layer extrusion T-die and then cooled quickly.

Resin-coated steel sheet for drawn-and-ironed cans and drawn-and-ironed

A surface-treated steel sheet is provided, at a low cost, which has high weldability and is useful for a material of containers of foods and beverages. The surface treatment is conducted by applying flattened granular tin coating deposits having a specified diameter and high adhesion on a steel sheet surface at a specified plated area ratio, and applying thereon a metallic chromium coating and a chromium hydrate oxide coating. In the surface treatment, firstly, the surface of a steel sheet is subjected to tin-plating in an acidic tin plating bath containing a conventionally used brightener in an amount of from 0,001 to 0.05 g/l so as to form flattened granular tin coating deposits having a diameter of 0.4-2.4 .mu. at a plated area ratio of 5 to 30% and to improve the adhesion to the steel sheet and decrease falling-off of the granular tin coating deposits until completion of chrome-plating, thereby the variation of the amount of tin coating being decreased. Subsequently, the sheet is plated with metallic chromium in an amount of 50-150 mg/m.sup.2, and further chromium hydrate oxide layer is formed in an amount of 2-40 mg/m.sup.2 as chromium. Thus a surface-treated steel sheet, which has satisfactory surface appearance, paint adhesiveness, under-paint-coating corrosion resistance of conventional tin-free steel sheets, and stable weldability, is producible at a low cost.

Process for producing surface-treated steel sheet superior in

A surface-treated steel sheet is provided, at a low cost, which has high weldability and is useful for a material of containers of foods and beverages. The surface treatment is conducted by applying flattened granular tin coating deposits having a specified diameter and high adhesion on a steel sheet surface at a specified plated area ratio, and applying thereon a metallic chromium coating and a chromium hydrate oxide coating. In the surface treatment, firstly, the surface of a steel sheet is subjected to tin-plating in an acidic tin plating bath containing a conventionally used brightener in an amount of from 0.001 to 0.05 g/1 so as to form flattened granular tin coating deposits having a diameter of 0.4-2.4 .mu. at a plated area ratio of 5 to 30% and to improve the adhesion to the steel sheet and decrease falling-off of the granular tin coating deposits until completion of chrome-plating, thereby the variation of the amount of tin coating being decreased. Subsequently, the sheet is plated with metallic chromium in an amount of 50-150 mg/m.sup.2, and further chromium hydrate oxide layer is formed in an amount of 2-40 mg/m.sup.2 as chromium. Thus a surface-treated steel sheet, which has satisfactory surface appearance, paint adhesiveness, under-paint-coating corrosion resistance of conventional tin-free steel sheets, and stable weldability, is producible at a low cost.

The present invention relates to preparation of insoluble electrodes having few surface defects and long life. The process for the preparation of electrodes comprises coating the surface of an electroconductive, corrosion resisting base metal (1) with at least one member selected from the platinum group metals and applying laser beams having energy density of 1 KW/cm.sup.2 or higher to the coated surface at a laser energy of 10 Kjoule/cm.sup.2 or less, thereby improving said surface due to its rapid heat treatment.

Growing community of inventors

Himeji, Japan

Ryoichi Yoshihara