Resin fine particles, method of producing resin fine particles, method of producing resin particles, and method of producing toner

A method of producing a resin particle, the method comprising the step of:

• mixing a resin fine particle, an organic solvent, and a resin R with a dispersion medium comprising carbon dioxide, to prepare a dispersion, in which a droplet comprising the resin R is dispersed in the dispersion medium, and
• a surface of the droplet being covered with the resin fine particle;
• wherein
• the resin fine particle contains one or more resins that have a partial structure A, a partial structure B, and a partial structure C,
• the resin fine particle is soluble in chloroform,
• a resin A constituted of only the partial structure A and a resin B constituted of only the partial structure B are soluble in the organic solvent,
• a resin C constituted of only the partial structure C is insoluble in the organic solvent, and
• the resin fine particle satisfies following formulas (1) and (2):
• |SPR−SPA|≤2.0 formula (1)
• 3.0≤(SPA−SPB) formula (2)
• where, SPA represents an SP value of the partial structure A, SPB represents an SP value of the partial structure B, and SPR represents an SP value of the resin R.

A resin fine particle comprising a resin X having a partial structure A, a partial structure B, and a partial structure C, or

• a resin fine particle comprising a resin Y having a partial structure A and a partial structure C and a resin Z having a partial structure B and a partial structure C, wherein
• following formula (2) is satisfied
• 3.0≤(SPA−SPB) formula (2)
• where SPA is an SP value of the partial structure A and SPB is an SP value of the partial structure B,
• a resin A constituted of only the partial structure A and a resin B constituted of only the partial structure B are soluble in an organic solvent,
• a resin C constituted of only the partial structure C is insoluble in the organic solvent, and
• the organic solvent is at least one selected from the group consisting of acetone, ethyl acetate, methyl ethyl ketone, tetrahydrofuran, and 2-phenylethyl alcohol.