Toner and method of producing toner
An object of the present invention is to provide a toner that exhibits high levels of the low-temperature fixability, storability, and charging performance all at the same time. The toner of the present invention is a toner that has a toner particle comprising a crystalline resin and an amorphous resin, the toner being characterized in that the toner satisfies 0.00≤(Wt2/Wt1)≤0.50; the toner particle has a matrix-domain structure in which domains of the crystalline resin are present in a matrix of the amorphous resin; at least 90 number % of the crystalline resin domains are domains with a diameter from 0.05 μm to 0.50 μm; and SF1 for the crystalline resin domains is from 100 to 130.
1. A method of producing a toner comprising a toner particle comprising a crystalline polyester resin and an amorphous polyester resin, the production method comprising:
an aggregation step of obtaining aggregate particles by mixing an amorphous polyester resin microparticle dispersion comprising dispersed microparticles of the amorphous polyester resin, with a crystalline polyester resin microparticle dispersion comprising dispersed microparticles of the crystalline polyester resin, and carrying out an aggregation in which microparticles including the amorphous polyester resin microparticles and the crystalline polyester resin microparticles are aggregated; and
a fusion step of carrying out a fusion treatment on the aggregate particles by adding at a fusion treatment temperature an organic solvent that, at the fusion treatment temperature, is a good solvent for the amorphous polyester resin and a poor solvent for the crystalline polyester resin, wherein
the fusion treatment temperature is a temperature that is not larger than the onset temperature of the crystal melting peak of the crystalline polyester resin as measured with a differential scanning calorimeter (DSC),
the crystalline polyester resin is obtained by condensation polymerization of a diol component containing at least one compound selected from the group consisting of 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol, and a dicarboxylic acid component containing at least one compound selected from the group consisting of suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, and 1,18-octadecanedicarboxylic acid,
the amorphous polyester resin is obtained by condensation polymerization of a diol component that is a bisphenol derivative represented by formula (1)
(where R represents an ethylene group or propylene group, x and y are each an integer equal to or greater than 1, and the average value of x+y is from 2 to 10), and a carboxylic acid component containing at least one compound selected from the group consisting of fumaric acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid,
the toner particle has a matrix-domain structure in which domains of the crystalline polyester resin are present in a matrix of the amorphous polyester resin, at least 90 number % of the crystalline polyester resin domains having a diameter from 0.05 μm to 0.50 μm,
SF1 for the crystalline polyester resin domains is from 100 to 130 as calculated by SF1=(ML 2 /A)×(π/4)×100 where ML represents the absolute maximum length of the crystalline polyester resin domains and A represents a projected area of the crystalline polyester resin domains, and
the toner satisfies 0.00≤(Wt2/Wt1)≤0.50 where Wt1 represents heat of fusion (J/g) originating with the crystalline polyester resin during a first temperature ramp up in measurement on the toner using a differential scanning calorimeter (DSC), and Wt2 represents heat of fusion (J/g) originating with the crystalline polyester resin during a second temperature ramp up in measurement on the toner using a differential scanning calorimeter (DSC).
2. The method of producing toner according to claim 1 , wherein the clystalline polyester resin is obtained by condensation polymerization of a diol component containing at least one compound selected from the group consisting of 1, 9-nonanediol, 1, 12-dodecanediol and a dicarboxylic acid component containing sebacic acid.
3. The method of producing toner according to claim 1 , wherein the toner particle contains from 10 to 40 mass % of the crystalline resin.
4. The method of producing toner according to claim 1 , wherein the melting point of the crystalline resin is from 50° C. to 100° C.