THERMOSETTING TOPCOAT VARNISH COMPOSITION FOR METAL CONTAINER AND METAL LAMINATE

• Main Authors: OCHI MAMORU, YARIMIZU KIYOTAKA, OKADA HIROSHI
• Format: Patent
• Language: English; Japanese
• Published: 16.09.2021
• Subjects: ADHESIVES; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; CORRECTING FLUIDS; DYES; FILLING PASTES; 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; TRANSPORTING; USE OF MATERIALS THEREFOR; WOODSTAINS

To provide a topcoat varnish composition which satisfies processibility, scratch resistance and retort resistance without providing an undercoat layer as an outer surface topcoat of a metal container subjected to advanced processing, and has an appropriate torque value when a cap is opened even in a can with a screw cap for a hot pack sale with retort sterilization.SOLUTION: A thermosetting varnish composition for a metal container containing a polyester resin and an organic solvent contains, with respect to 100 pts.mass (in terms of solid content) of a polyester resin (A) having a number average molecular weight of 2,000 to 8,000, a glass transition temperature of 20 to 70°C and a hydroxyl value of 10 to 30 KOHmg/g, 20 to 80 pts.wt. of a polyester resin (B) having a number average molecular weight of 2,000 to 6,000 and a hydroxyl value of 35 to 55 KOHmg/g, 60 to 120 pts.wt. of an amino resin (C), 5 to 30 pts.wt. of an epoxy resin (D), and 5 to 30 pts.wt. of block type isocyanate (E) having a dissociation temperature of 110 to 150°C.SELECTED DRAWING: None 【課題】高度な加工を施された金属容器の外面トップコートとして、下塗り層を施さなくても加工性、傷つき性、耐レトルト性を満たし、且つ、レトルト殺菌を伴い、ホットパック販売の為のネジ口付き缶でも、キャップを開栓時の適正なトルク値を有すトップコートニス組成物。【解決手段】ポリエステル樹脂及び有機溶剤を含有する金属容器用熱硬化型ニス組成物であって、数平均分子量２０００〜８０００、ガラス転移温度２０〜７０℃、水酸基価１０〜３０ＫＯＨｍｇ／ｇのポリエステル樹脂（Ａ）１００重量部（固形分換算）に対して、数平均分子量２０００〜６０００、水酸基価３５〜５５ＫＯＨｍｇ／ｇのポリエステル樹脂（Ｂ）２０〜８０重量部、アミノ樹脂を（Ｃ）６０〜１２０重量部、エポキシ樹脂（Ｄ）５〜３０重量部、解離温度が１１０〜１５０℃であるブロック型イソシアネート（Ｅ）を５〜３０重量部含有する金属容器用熱硬化型トップコートニス組成物【選択図】なし