Method for producing composite resin particle dispersion, method for producing pressure-sensitive adhesive, method for producing pressure-responsive resin, method for producing toner for electrostatic charge image development, and composite resin particle dispersion

A method for producing a composite resin particle dispersion, the method comprising:

• polymerizing a (meth)acrylic acid ester compound to form a (meth)acrylic acid ester-based resin, wherein the (meth)acrylic acid ester compound includes 2-ethylhexyl acrylate and n-butyl acrylate;
• and
• polymerizing a styrene compound and a vinyl monomer other than the styrene compound in the presence of the (meth)acrylic acid ester-based resin to form composite resin particles containing a styrene-based resin and the (meth)acrylic acid ester-based resin,
• wherein
• a mass percentage of the (meth)acrylic acid ester compound relative to a total mass of polymer components of the (meth)acrylic acid ester-based resin is 98 mass % or more,
• a mass percentage of the styrene relative to a total mass of polymer components of the styrene-based resin is 60 mass % or more and 95 mass % or less,
• a mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin in the composite resin particles is from 80:20 to 20:80,
• a difference between the lowest glass transition temperature and the highest glass transition temperature in the composite resin particles is 30° C. or more,
• a weight average molecular weight of the resins in the composite resin particles is 66,000 or more and 250,000 or less.