Electrophotographic developer set comprising toner and powder adhesive, method for producing bonded product, and powder adhesive

A method for producing a bonded product resulting from bonding at least one sheet of paper via an adhesive portion by using an electrophotographic developer set, wherein:

• the electrophotographic developer set comprises:
• a toner comprising a thermoplastic resin and a wax;
• and
• a powder adhesive comprising a thermoplastic resin and a wax,
• where Ea (mmol/g) denotes an ester group concentration of the wax contained in the toner, Na (mass %) denotes a content of the wax in the toner, Eb (mmol/g) denotes an ester group concentration of the wax contained in the powder adhesive, and Nb (mass %) denotes a content of the wax in the powder adhesive, the Ea, the Na, the Eb and the Nb satisfy formulae:
• 0.00≤Ea≤2.45,
• 2.50≤Eb≤3.60, and
• 0.80≤Nb/Na,
• wherein:
• the bonded product has a surface A on which an adhesive portion of the powder adhesive is fixed, and a toner image portion of the toner is fixed,
• wherein the method comprises steps (A) and (B):
• (A) forming the toner image portion and the adhesive portion on at least one surface of the surface A, and fixing the toner image portion and the adhesive portion by heating;
• and
• (B) forming the adhesive portion on one surface of the surface A and fixing the adhesive portion by heating, and forming the toner image portion on at least the other surface of the surface A and fixing the toner image portion by heating, and
• wherein:
• the method further comprises, after the forming and the fixing of the toner image portion and the adhesive portion, steps of:
• overlaying the paper so as to interpose the adhesive portion;
• and
• melting the adhesive portion thereby bonding the paper to obtain the bonded product.

A powder adhesive comprising:

• a thermoplastic resin;
• a compound represented by formula (1):
• where, in the formula (1), 1 represents 2, and n and m each independently represents a positive integer of 14 to 20;
• and
• a chain saturated hydrocarbon having a peak carbon number of 20 to 70,
• wherein:
• the thermoplastic resin is a styrene-acrylic resin;
• a content of the thermoplastic resin in the powder adhesive is 75.0 to 92.0 mass %;
• a content Nb1 of the compound represented by the formula (1) in the powder adhesive is 8.0 to 20.0 mass %;
• a content Nb2 of the chain saturated hydrocarbon having a peak carbon number of 20 to 70 in the powder adhesive is 0.1 to 5.0 mass %;
• and
• the Nb1 and the Nb2 satisfy:
• 2.00≤Nb1/Nb2≤25.00