Toner
A toner comprising a toner particle comprising a binder resin, wherein the toner particle further comprises a monohydric aliphatic alcohol, and an anionic surfactant having an alkyl group, the binder resin comprises a polyester resin, a carbon number of the monohydric aliphatic alcohol is 8 to 18, a content of the monohydric aliphatic alcohol when extracted from the toner with ethanol is 30 to 300 ppm by mass in the toner, and a value of a ratio (molar ratio) of the monohydric aliphatic alcohol extracted from the toner with ethanol relative to the anionic surfactant having an alkyl group extracted from the toner with methanol is 0.01 to 0.60.
1 . A toner, comprising:
a toner particle comprising a binder resin, a monohydric aliphatic alcohol and an anionic surfactant having an alkyl group;
the binder resin consisting of (i) a polyester resin and (ii) optionally containing a styrene acrylic resin; and
a carbon number of the monohydric aliphatic alcohol being 8 to 18, wherein
a content of the monohydric aliphatic alcohol when extracted from the toner with ethanol is 30 to 300 ppm by mass in the toner when measured according to the following protocol (i) to (v)
(i) mixing 2 g of toner and 18 g of ethanol to produce a mixture A,
(ii) irradiating the mixture A with ultrasonic waves for 5 minutes,
(iii) allowing the mixture A to stand overnight in a constant temperature chamber at 60° C. after irradiation with ultrasonic waves, and further allowing the mixture A to stand at room temperature for three additional days,
(iv) filtering a supernatant of the mixture A after standing through a PTFE syringe filter (pore diameter 250 nm) to obtain a filtrate A, and
(v) analyzing the filtrate A by gas chromatography to obtain the content of the monohydric aliphatic alcohol extracted from the toner with ethanol, and
a value of a ratio (molar ratio) of the monohydric aliphatic alcohol extracted from the toner with ethanol when measured according to the protocol (i) to (v) relative to the anionic surfactant having an alkyl group extracted from the toner with methanol when measured according to the following protocol (vi) to (ix) is 0.01 to 0.60
(vi) mixing 1 g of toner and 10 g of methanol to produce a mixture B,
(vii) treating the mixture B for 20 minutes in an ultrasonic cleaner held at a water temperature of 30° C.±2° C.,
(viii) filtering off the mixture B treated with the ultrasonic cleaner to obtain a filtrate B, and
(ix) analyzing the filtrate B by high performance liquid chromatography to obtain the content of the anionic surfactant having an alkyl group extracted from the toner with methanol.
2 . The toner according to claim 1 , wherein a content of the polyester resin in the binder resin is 50 mass % or more.
3 . The toner according to claim 1 , wherein the anionic surfactant having an alkyl group is represented by R—X—SO 3 − Na + when R is an alkyl group having 8 to 18 carbon atoms, X is a single bond, —O—, a phenylene group or —(OCH 2 CH 2 ) n —, and n is 2 to 10.
4 . The toner according to claim 1 , wherein the anionic surfactant having an alkyl group comprises a sodium straight chain alkylbenzene sulfonate.
5 . The toner according to claim 4 , wherein a difference between the carbon number of the monohydric aliphatic alcohol and a carbon number of the alkyl group of the sodium straight chain alkylbenzene sulfonate is 3 or less.
6 . The toner according to claim 1 , wherein the polyester resin comprises a monomer unit represented by formula (1)
when R 1 and R 2 are independently an ethylene group or a propylene group, x and y are each 0 to 8, and the sum of x and y is 0 to 16, and
a content of the monomer unit represented by formula (1) in the polyester resin is 5.0 mass % or less.
7 . The toner according to claim 1 , wherein the monohydric aliphatic alcohol has a carbon number of 10 to 16.
8 . The toner according to claim 1 , wherein the content of the monohydric aliphatic alcohol extracted from the toner with ethanol is 40 to 270 ppm by mass in the toner.
9 . The toner according to claim 1 , wherein the value of the ratio (molar ratio) of the monohydric aliphatic alcohol extracted from the toner with ethanol relative to the anionic surfactant having an alkyl group extracted from the toner with methanol is 0.02 to 0.45.