PRECOATED STEEL SHEET

• Main Authors: FUJISAWA HIDETSUGU, ASHIKARI ICHIRO, SHIN OSAMU, OSHIMA YASUHIDE
• Format: Patent
• Language: English; Japanese
• Published: 13.06.2024
• Subjects: ADHESIVES; CHEMICAL PAINT OR INK REMOVERS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; CORRECTING FLUIDS; DIFFUSION TREATMENT OF METALLIC MATERIAL; DYES; FILLING PASTES; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; INKS; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; PERFORMING OPERATIONS; POLISHES; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING; USE OF MATERIALS THEREFOR; WOODSTAINS

To provide a precoated steel sheet which has good adhesion between a chemically converted coating and a primer coating, and is excellent in corrosion resistance of a worked portion and a cut end.SOLUTION: A chemically converted coating includes a resin component and an inorganic compound, contains 30 to 54 mass% of an epoxy resin having a bisphenol skeleton as the resin component and 46 to 70 mass% of a vanadium oxide, a zirconium oxide and a fluorine compound in total as the inorganic compound, and a primer coating film includes a resin component and an inorganic compound, contains 40 to 88 mass% of an epoxy resin (e) having an urethane bod and a polyester resin (p) in total as the resin component, has a content mass ratio (e):(p) of the epoxy resin (e) and the polyester resin (p) of 80:20 to 60:40, and contains 4 to 20 mass% of the vanadium compound, 4 to 20 mass% of a phosphate compound and 4 to 20 mass% of a magnesium oxide as the inorganic compound.SELECTED DRAWING: None 【課題】化成処理皮膜とプライマー塗膜との密着性が良好であり、加工部及び切断端部の耐食性に優れた塗装鋼板を提供する。【解決手段】上記目的を達成するべく、本発明は、化成処理皮膜は、樹脂成分及び無機化合物を含み、前記樹脂成分として、ビスフェノール骨格を有するエポキシ樹脂を30～54質量％含有し、前記無機化合物として、バナジウム酸化物、ジルコニウム酸化物及びフッ素化合物を合計で46～70質量％含有し、プライマー塗膜は、樹脂成分及び無機化合物を含み、前記樹脂成分として、ウレタン結合を有するエポキシ樹脂（ｅ）及びポリエステル樹脂（ｐ）を、合計で40～88質量％含有し、前記エポキシ樹脂（ｅ）と前記ポリエステル樹脂（ｐ）の含有量が、質量比で（ｅ）：（ｐ）＝80：20～60：40であり、前記無機化合物として、バナジウム化合物を4～20質量％、リン酸化合物を4～20質量％及び酸化マグネシウムを4～20質量％含有することを特徴とする。【選択図】なし