Production method for grain-oriented electrical steel sheet

A method for producing a grain-oriented electrical steel sheet, the method comprising:

• a hot rolling process of heating and hot rolling a slab having a slab composition comprising, by mass %, C:
• 0.02% or more and 0.10% or less, Si:
• 2.5% or more and 4.5% or less, Mn:
• 0.01% or more and 0.30% or less, a total of one or both of S and Se:
• 0.001% or more and 0.050% or less, acid soluble Al:
• 0.01% or more and 0.05% or less, N:
• 0.002% or more and 0.020% or less, P:
• 0.0400% or less, and Cu:
• 0.05% or more and 0.50% or less and having a balance of Fe and impurities to obtain a hot rolled steel sheet,
• a process of obtaining a pickled sheet by either dipping the hot rolled steel sheet in a pickling solution, or annealing the hot rolled steel sheet to obtain a hot rolled annealed sheet and then dipping the hot rolled annealed sheet in the pickling solution, the pickling solution containing 0.0001 g/L or more and 5.00 g/L or less of Cu,
• a cold rolling process of cold rolling the pickled sheet to obtain a cold rolled steel sheet, a thickness of the cold rolled steel sheet being 0.15 mm or more and 0.23 mm or less,
• a primary recrystallization annealing process of annealing the cold rolled steel sheet to obtain a primary recrystallized annealed sheet, the primary recrystallization annealing process including a temperature raising process to a decarburization annealing temperature, and a decarburization annealing process, wherein an average rate of temperature rise in a temperature region of 30° C. to 400° C. in the temperature raising process is more than 50° C./s and 1000° C./s or less,
• a finish annealing process of coating a surface of the primary recrystallized annealed sheet with an annealing separator containing MgO, then finish annealing the sheet to obtain a finish annealed sheet, and
• a flattening annealing process of coating the finish annealed sheet with an insulation coating to obtain a coated finish annealed sheet, then annealing the coated finish annealed sheet.