JP4076932B2 - toner - Google Patents

Description

  The present invention contains a crystalline polyester suitable for toner as a binder resin for toner used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like, and the crystalline polyester. It relates to toner.

  To save energy, a toner using crystalline polyester has been proposed, and excellent low-temperature fixability has been obtained (see Patent Documents 1 and 2).

However, the toner containing the crystalline polyester has low productivity, and for example, it takes time to solidify the melt-kneaded product of the toner. In addition, the toner cannot be said to have sufficient environmental resistance stability, and improvements are desired. A method of adding a crystal nucleating agent at the time of production (see Patent Document 3) or the like is used to improve the productivity of toner containing crystalline polyester, and a method of reducing the acid value of the polyester (Patent Document 3). Document 4) is known. However, it is difficult to solve both problems simultaneously by either method.
JP 2001-222138 A (Claim 1) Japanese Patent Laying-Open No. 2003-137991 (Claim 1) JP 2002-72567 A (Claim 1) Japanese Patent Laid-Open No. 11-174733 (Claim 1)

  An object of the present invention is to provide a crystalline polyester for toner having high productivity and excellent environmental resistance, and a toner containing the polyester.

  The present invention is a toner in which the content of a component having a molecular weight of 1000 or less is 3% by weight or less, and the ratio of the softening point to the maximum peak temperature of heat of fusion (softening point / peak temperature) is 0.6 to 1.3. The present invention relates to a crystalline polyester for use and a toner containing the crystalline polyester.

  Since the crystalline polyester for toner of the present invention has high productivity and excellent environmental resistance, it can be suitably used as a binder resin for toner.

  The present inventors consider that an improvement in the crystallization speed of a crystalline polyester is effective for improving productivity, and a reduction in polar groups is effective for improving environmental resistance, and a method for simultaneously solving these problems is studied. As a result, the inventors have found that the object can be achieved by reducing the low molecular weight components such as residual monomers and oligomers in the polyester, and completed the present invention.

  That is, the crystalline polyester for toner of the present invention is characterized in that the content of the low molecular weight component is not more than a specific value, and the content of the component having a molecular weight of 1000 or less in the crystalline polyester of the present invention is 3% by weight. %, Preferably 2 to 0.1% by weight, and the content of components having a molecular weight of 500 or less is preferably 1% by weight or less, more preferably 0.5 to 0.1% by weight.

  In the present invention, “crystallinity” means that the ratio of the softening point to the maximum peak temperature of the heat of fusion (softening point / peak temperature) is 0.6 to 1.3, preferably 0.9 to 1.2, more preferably. 0.95 to 1.1, and “amorphous” means that the ratio of the softening point to the maximum peak temperature of the heat of fusion (softening point / peak temperature) is greater than 1.3 and 4 or less, Preferably it is 1.5-3.

  In the present invention, the crystalline polyester has an alcohol component containing 80 mol% or more of an aliphatic diol having 2 to 6 carbon atoms, preferably 4 to 6 carbon atoms, and 2 to 8 carbon atoms, preferably 4 to 6 carbon atoms. Is preferably a resin obtained by polycondensation of a carboxylic acid component containing 80 mol% or more of the aliphatic dicarboxylic acid compound 4.

  Examples of the aliphatic diol having 2 to 6 carbon atoms include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, Neopentyl glycol, 1,4-butenediol and the like can be mentioned, and α, ω-linear alkanediol is particularly preferable. Since the aliphatic diol having 2 to 6 carbon atoms has high water absorption, it may cause a decrease in chargeability due to water absorption, that is, a decrease in environmental resistance, but the crystalline polyester of the present invention has a low molecular weight component. Since the content is reduced, a decrease in environmental resistance is suppressed.

  It is desirable that the aliphatic diol having 2 to 6 carbon atoms is contained in the alcohol component at 80 mol% or more, preferably 80 to 100 mol%, more preferably 90 to 100 mol%. In particular, it is desirable that one aliphatic diol in them accounts for 70 mol% or more, preferably 80 to 95 mol% in the alcohol component. Among these, 1,4-butanediol or 1,6-hexanediol is preferably contained in the alcohol component in an amount of 60 mol% or more, more preferably 70 to 100 mol%, particularly preferably 80 to 100 mol%. Is desirable.

  The alcohol component may contain a polyhydric alcohol component other than the aliphatic diol having 2 to 6 carbon atoms. As the polyhydric alcohol component, polyoxypropylene (2.2) -2,2-bis Alkylene (2 to 3 carbon atoms) oxide of bisphenol A such as (4-hydroxyphenyl) propane and polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane (average added mole number 1 to 10) Trivalent or higher alcohols such as aromatic diols such as adducts, glycerin, pentaerythritol, and trimethylolpropane.

  Examples of the aliphatic dicarboxylic acid compound having 2 to 8 carbon atoms include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, and anhydrides of these acids, alkyl (C1-C3) ester etc. are mentioned, In these, fumaric acid and adipic acid are preferable and fumaric acid is more preferable. In addition, as mentioned above, the aliphatic dicarboxylic compound refers to an aliphatic dicarboxylic acid, its anhydride, and its alkyl (C1-3) ester. Among these, an aliphatic dicarboxylic acid is preferable.

  The aliphatic dicarboxylic acid compound having 2 to 8 carbon atoms is desirably contained in the carboxylic acid component in an amount of 80 mol% or more, preferably 80 to 100 mol%, more preferably 90 to 100 mol%. In particular, it is desirable that one aliphatic dicarboxylic acid compound in them accounts for 60 mol% or more, preferably 70 to 100 mol%, more preferably 80 to 100 mol% in the carboxylic acid component.

  Especially, it is desirable that fumaric acid is contained in the carboxylic acid component in an amount of preferably 60 mol% or more, more preferably 70 to 100 mol%, and particularly preferably 80 to 100 mol%. However, when fumaric acid is used, from the viewpoint of environmental resistance, the content of fumaric acid remaining in the crystalline polyester is preferably less than 0.3% by weight, preferably 0.25% by weight in the crystalline polyester. The following is more preferable, and 0.03 to 0.15% by weight is particularly preferable.

  The carboxylic acid component may contain a polyvalent carboxylic acid component other than the aliphatic dicarboxylic acid compound having 2 to 8 carbon atoms. Examples of the polyvalent carboxylic acid component include phthalic acid, isophthalic acid, terephthalic acid and the like. Aromatic dicarboxylic acids; sebacic acid, azelaic acid, n-dodecyl succinic acid, n-dodecenyl succinic acid aliphatic dicarboxylic acid; cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids; trimellitic acid, pyromellitic acid and the like trivalent The above polyvalent carboxylic acids; and anhydrides of these acids, alkyl (C1-C3) esters, and the like.

  The ratio of the hydroxyl group of the alcohol component to the carboxylic acid group of the carboxylic acid component is preferably close to 1.0 from the viewpoint of reducing the content of the low molecular weight component, specifically 0.8 to 1 .2 is preferable, and 0.95 to 1.05 is more preferable.

  The alcohol component and the carboxylic acid component can be polycondensed in an inert gas atmosphere by reacting them at a temperature of 120 to 230 ° C., if necessary, using an esterification catalyst, a polymerization inhibitor, etc. As a means of reducing the content of low molecular weight components, a method of adding a highly reactive compound such as an epoxy compound just before the end of the reaction, a method of distilling off low molecular weight components at high temperature under reduced pressure, a steaming treatment, a solvent Examples of the method include washing. Among these methods, solvent cleaning is preferable from the viewpoint of the removal efficiency of low molecular weight components.

  Therefore, the crystalline polyester of the present invention is preferably produced by a method having a solvent washing step. In the present invention, solvent washing refers to a method in which a polymer obtained by condensation polymerization of an alcohol component and a carboxylic acid component is washed with a solvent, and a low molecular weight component is dissolved in the solvent and removed. The solvent used for solvent cleaning is preferably a liquid that is 20 ° C. and has a boiling point of 150 ° C. or less at 1 atm. Further, a solvent that dissolves low molecular weight components well but does not dissolve high molecular weight components is preferable. . Hildebrand's solubility parameter δ (see “Solvent Handbook”, 14th edition, Kodansha, 1992, p.62-63) is a solvent that deviates from this value because solvents around 9.0 are likely to dissolve polyester. For example, a solvent having δ of 9.1 or more or 8.8 or less is preferable, and specifically, water (21: δ is shown), methanol (12.9), ethanol (11.2), Examples include dioxane (9.8), tetrahydrofuran (9.1), ethyl acetate (8.6), hexane (7.3), a mixture thereof, and the like, and δ is 9.1-13 and 7-8.8. The solvent of δ is preferably 9.1-12, more preferably dioxane (9.8) and tetrahydrofuran (9.1). Furthermore, as a method for efficiently removing low molecular weight substances by solvent washing, a solvent having a solubility parameter close to 9.0 is used at the sacrifice of the resin recovery rate, or a solubility parameter such as water (21) is 9.0. For example, a method of heating and using a solvent greatly deviating from the above can be used.

  From the viewpoint of efficiently removing low molecular weight components, the polymer used for solvent washing is preferably a coarsely pulverized product that is preferably pulverized to 5 mm or less, more preferably about 3 mm or less. The ratio of the polymer and the solvent may be appropriately selected in consideration of the recovery rate of the resin, the desired degree of purification, the labor of solvent recovery, etc., but is preferably 50 to 500 parts by weight with respect to 100 parts by weight of the resin. 100 to 300 parts by weight is more preferable.

  The polymer is washed with a solvent, for example, preferably in a solvent heated to 10 to 50 ° C., more preferably 20 to 40 ° C., and the polymer is preferably about 1 to 10 hours, more preferably about 3 to 6 hours. The washing can be performed by stirring, and the washed polymer can be collected by filtration or the like.

  The softening point of the crystalline polyester is preferably 60 to 150 ° C, more preferably 60 to 110 ° C, and the maximum peak temperature of the heat of fusion is preferably 50 to 140 ° C, more preferably 55 to 100 ° C.

  The toner of the present invention contains the crystalline polyester of the present invention as a binder resin, but the toner preferably further contains an amorphous resin as the binder resin. The content of the crystalline polyester is preferably 1 to 50% by weight, more preferably 5 to 40% by weight, and more preferably 10 to 30% by weight in the binder resin from the viewpoints of storage stability, fixability and toner manufacturability. Particularly preferred.

  Amorphous resins include amorphous polyesters, amorphous polyester polyamides, amorphous styrene-acrylic resins, etc. Among these, from the viewpoint of fixability and compatibility with crystalline polyester, Amorphous polyester is preferred.

Amorphous polyester can also be produced by polycondensing an alcohol component and a carboxylic acid component in the same manner as crystalline polyester. However, in order to make amorphous polyester,
(1) In the case of using a monomer that promotes crystallization of a resin such as an aliphatic diol having 2 to 6 carbon atoms or an aliphatic carboxylic acid compound having 2 to 8 carbon atoms, two or more of these monomers are used in combination. That is, in any of the alcohol component and the carboxylic acid component, one of these monomers accounts for 10 to 70 mol%, preferably 20 to 60 mol% of each component, and these monomers are 2 More than one species, preferably 2-4 species, or
(2) A monomer that promotes resin amorphization, preferably an alkylene oxide adduct of bisphenol A in the alcohol component, or a succinic acid substituted with an alkyl group or an alkenyl group in the carboxylic acid component is contained in the alcohol component or In the carboxylic acid component, preferably 30 to 100 mol%, preferably 50 to 100 mol% is used in each of both components.

  The softening point of the amorphous polyester is preferably 70 to 180 ° C, more preferably 100 to 160 ° C, and the glass transition point is preferably 45 to 80 ° C, more preferably 55 to 75 ° C. The glass transition point is a physical property peculiar to an amorphous resin, and is distinguished from the maximum peak temperature of heat of fusion.

  As the amorphous polyester, two types of amorphous polyesters having different softening points of 10 ° C. or more may be used from the viewpoint of low-temperature fixability and high-temperature offset resistance.

  The toner of the present invention further includes a colorant, a charge control agent, a release agent, a conductivity modifier, an extender pigment, a reinforcing filler such as a fibrous substance, an antioxidant, an anti-aging agent, a fluidity improver, Additives such as a cleaning property improving agent may be appropriately contained.

  As the colorant, all of dyes and pigments used as toner colorants can be used, such as carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, Quinacridone, Carmine 6B, Disazo Yellow and the like can be used, and these can be used alone or in admixture of two or more. Either toner or full color toner may be used. The content of the colorant is preferably 1 to 40 parts by weight and more preferably 3 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  Charge control agents include nigrosine dyes, triphenylmethane dyes containing tertiary amines as side chains, quaternary ammonium salt compounds, polyamine resins, imidazole derivatives and other positively chargeable charge control agents and metal-containing azo dyes, copper Examples include negatively chargeable charge control agents such as phthalocyanine dyes, metal complexes of alkyl derivatives of salicylic acid, and boron complexes of benzylic acid.

  Examples of mold release agents include natural waxes such as carnauba wax and rice wax, synthetic waxes such as polypropylene wax, polyethylene wax, and Fischer Tropu, coal waxes such as montan wax, alcohol waxes, ester waxes, and the like. These may be contained alone or in admixture of two or more, and among these, carnauba wax, polypropylene wax and Fischer Tropu are preferred from the viewpoint of compatibility with the binder resin.

  The toner of the present invention may be a toner produced by any conventionally known method such as a pulverized toner by a kneading pulverization method, a chemical toner by a phase inversion emulsification method, an emulsification dispersion method, etc. Therefore, a pulverized toner obtained by a kneading pulverization method is preferable.For example, after the binder resin of the present invention, a colorant, a charge control agent, a release agent, and the like are uniformly mixed with a mixer such as a Henschel mixer, a hermetically sealed type It can be manufactured by melt-kneading with a kneader or a single-screw or twin-screw extruder, an open roll kneader, etc., cooling, pulverizing and classifying. In the present invention, since the crystalline polyester of the present invention is used as the binder resin, the kneaded material after melt-kneading rapidly solidifies, and the toner can be produced efficiently. The volume average particle diameter of the toner of the present invention is preferably 3 to 15 μm. Further, a fluidity improver such as hydrophobic silica may be externally added to the surface of the toner.

  When the toner of the present invention contains a magnetic fine powder, it is used alone as a developer, and when it does not contain a magnetic fine powder, it is used as a non-magnetic one-component developer or mixed with a carrier to develop a two-component developer. It can be used as an agent.

[Softening point of resin]
Using a Koka type flow tester (manufactured by Shimadzu Corporation, CFT-500), a 1 g sample was heated at a heating rate of 6 ° C./min, a load of 1.96 MPa was applied by a plunger, a diameter of 1 mm, A nozzle with a length of 1 mm is pushed out, and this draws a plunger drop amount (flow value) -temperature curve of the flow tester. When the height of the S-shaped curve is h, the temperature corresponding to h / 2 (resin The temperature at which half of the effluent flowed out) is taken as the softening point.

[Maximum peak temperature of melting heat and glass transition point]
Using a differential scanning calorimeter (DSC210, manufactured by Seiko Denshi Kogyo Co., Ltd.), the sample was heated to 200 ° C. and cooled to 0 ° C. at a rate of temperature decrease of 10 ° C./min. Determine the maximum peak temperature of the heat of fusion. The glass transition point is defined as the temperature at the intersection of the base line extension below the maximum peak temperature in the measurement and the tangent line indicating the maximum slope from the peak rising portion to the peak apex.

[Content of low molecular weight component having a molecular weight of 1000 or less or 500 or less]
From the chart showing the molecular weight distribution by gel permeation chromatography obtained by the following method, the proportion of low molecular weight components having a molecular weight of 1000 or less or 500 or less is determined.
(1) Preparation of sample solution Add 0.5 g of resin to 100 ml of chloroform at 40 ° C., dissolve by stirring, and then cool to room temperature. Next, this solution is filtered using a fluororesin filter having a pore size of 2 μm (manufactured by Sumitomo Electric Industries, Ltd., FP-200) to obtain a sample solution.
(2) Measurement of molecular weight distribution Chloroform is flowed as an eluent at a flow rate of 1 ml / min, and the column is stabilized in a constant temperature bath at 40 ° C. 100 μl of the sample solution is injected therein and measurement is performed. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. For the calibration curve at this time, a sample prepared using several types of monodisperse polystyrene as a standard sample is used.
Measuring device: CO-8010 (manufactured by Tosoh Corporation)
Analysis column: GMHLX + G3000HXL (manufactured by Tosoh)

[Fumaric acid content]
1. Preparation of sample solution Dissolve 0.2 g of sample (resin) in 20 ml of toluene, add 2 ml of toluene solution and 5 ml of ion-exchanged water to a test tube with a lid, stir well using a touch mixer, and use a centrifuge. Phase separation is performed, and the lower layer (aqueous phase) is separated as a sample solution.

2. Preparation of calibration curve A calibration curve is prepared using an aqueous solution of 1-15 mg / l fumaric acid.

3. High-performance liquid chromatography measurement Eluent: 0.0001% phosphoric acid aqueous solution Device: Tosoh Corporation, 8020 series Autosampler: Injection volume 20 μl
Pump: Flow rate 1.0ml / min
Column oven: 40 ° C
Column: Chemical Substance Evaluation Research Organization L-Column ODS (4.0φ × 10 + 4.6φ × 150 mm)
Detector: UVD 210nm

Production Example 1 of Crystalline Polyester
The raw material monomers shown in Table 1, 4 g of dibutyltin oxide and 1 g of hydroquinone were placed in a 5-liter four-necked flask equipped with a nitrogen introduction tube, dehydration tube, stirrer and thermocouple, and reacted at 160 ° C. for 5 hours. Then, the temperature was raised to 200 ° C. and reacted for 1 hour. Furthermore, it was made to react until the resin of a desired molecular weight was obtained at 8.3 kPa, and resin ac was obtained.

Production Example 2 of Crystalline Polyester
The resin obtained in Production Example 1 was coarsely pulverized, and a sieve having an opening of 1 mm (upper) and a sieve having an opening of 710 μm (lower) were stacked and passed through a sieve. 1 kg of coarse powder remaining on a sieve having a mesh opening of 710 μm is placed in a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and 2 kg of ethyl acetate is added to the mixture at 20 ° C. And stirred for 4 hours.
After stirring, the mixture was filtered using a filter paper, and the resin collected on the filter paper was dried at 40 ° C. and 30 kPa for 2 hours to obtain resins df. The recovery rate of coarse powder was about 98% in all cases.

Production Example 3 of Crystalline Polyester
Resins g to i were obtained in the same manner as in Production Example 2 except that 2 kg of dioxane was used instead of ethyl acetate and the mixture was stirred at 25 ° C. The recovery rate of coarse powder was around 96% in all cases.

Production Example 4 of Crystalline Polyester
Resins j to l were obtained in the same manner as in Production Example 2 except that 2 kg of tetrahydrofuran was used instead of ethyl acetate and the mixture was stirred at 50 ° C. The recovery rate of coarse powder was about 90% in all cases.

  Softening point of the obtained resins a to l, maximum peak temperature of heat of fusion, content of components having a molecular weight of 1000 or less (1000 ≧), content of components having a molecular weight of 500 or less (500 ≧), and fumaric acid content Are shown in Tables 1 and 2.

Example of production of amorphous resin 4 g of 5 liters equipped with 4 g of BPA-PO, BPA-EO, terephthalic acid and dibutyltin oxide shown in Table 3 equipped with nitrogen introduction tube, dehydration tube, stirrer and thermocouple The flask was put into a flask and reacted at 220 ° C. for 8 hours, and then reacted at 8.3 kPa for 1 hour. Fumaric acid and trimellitic anhydride were added and reacted at 190 ° C. for 2 hours, and further reacted at 210 ° C. until the desired softening point was reached to obtain Resin A.

Examples 1-6, Comparative Examples 1-6
25 parts by weight of crystalline polyester shown in Table 4 and 75 parts by weight of resin A, 4 parts by weight of carbon black “Mogu L” (manufactured by Cabot), charge control agent “T-77” (manufactured by Hodogaya Chemical Co., Ltd.) 5 parts by weight and 1 part by weight of polypropylene wax “NP-055” (manufactured by Mitsui Chemicals) were mixed thoroughly with a Henschel mixer, and then the same-direction rotating twin-screw extruder (total length of kneading part: 1560 mm, screw diameter: 42 mm, The inner diameter of the barrel was 43 mm), the roll rotation speed was 150 rotations / minute, the heating temperature in the roll was adjusted to 100 ° C., and the supply speed of the mixture was adjusted to 20 kg / hour. The outlet temperature of the kneaded product was about 150 ° C., and the average residence time of the mixture was about 18 seconds.

  The melt-kneaded material obtained using a rolling roll was rolled to a thickness of 5 mm, cooled, coarsely pulverized, and then pulverized and classified by a jet mill to obtain a powder having a volume average particle size of 8.0 μm.

  To 100 parts by weight of the obtained powder, 1.0 part by weight of hydrophobic silica “Aerosil R-972” (manufactured by Nippon Aerosil Co., Ltd.) as an external additive is added and mixed with a Henschel mixer, whereby toner is obtained. Obtained.

Test example 1
In the production of toner, manufacturability was evaluated according to the following evaluation criteria from the state of the kneaded product when the kneaded product obtained by the melt-kneading step was rolled. The results are shown in Table 4.

〔Evaluation criteria〕
A: Rolling is possible without passing water through the rolling roll.
○: Rolling can be performed by passing water at about 20 ° C. through a rolling roll.
X: The kneaded material sticks to a rolling roll through which water of about 20 ° C. is passed, and toner production is difficult.

Test example 2
4 parts by weight of toner and 96 parts by weight of a silicone-coated ferrite carrier (manufactured by Kanto Denka Kogyo Co., Ltd., average particle size: 90 μm) were mixed for 10 minutes with a tumbler mixer to obtain a developer.
Next, a developer is mounted on an apparatus in which the copying machine “AR-505” (manufactured by Sharp Corporation, fixing speed: 100 mm / sec) is modified so that fixing can be performed outside the apparatus, and the toner adhesion amount is reduced to 0. The unfixed image of 2 cm × 12 cm was obtained by adjusting to 0.5 mg / cm ² . The fixing roll was tested by fixing the unfixed image while gradually increasing the temperature of the fixing roll from 90 ° C. to 240 ° C. in 5 ° C. increments. As the fixing paper, “CopyBond SF-70NA” (manufactured by Sharp Corporation, 75 g / m ² ) was used.

  The image obtained at each fixing temperature is rubbed 5 times with a sand eraser having a bottom of 15 mm × 7.5 mm with a load of 500 g, and the optical reflection density before and after rubbing is measured by a reflection densitometer “RD-915” (manufactured by Macbeth). ). The fixing roller temperature at which the ratio between the two (after rubbing / before rubbing) first exceeded 70% was set as the minimum fixing temperature, and the low-temperature fixing property was evaluated according to the following evaluation criteria. The results are shown in Table 4.

〔Evaluation criteria〕
A: Minimum fixing temperature is less than 110 ° C. ○: Minimum fixing temperature is 110 ° C. or higher and lower than 130 ° C. ×: Minimum fixing temperature is 130 ° C. or higher.

Test example 3
Using the same copying machine as in Test Example 2, the copying machine mounted with the developer was left in an environment of a temperature of 37 ° C. and a relative humidity of 70% for 1 day, and then a solid image was printed and fixed at 160 ° C. The obtained solid image was visually observed and the environmental resistance was evaluated according to the following evaluation criteria. The results are shown in Table 4.

〔Evaluation criteria〕
A: Solid image appears well and there is almost no fogging.
○: The solid image appears well and there is no problem in actual use although there is some fogging.
Δ: The solid image has a slightly lower density and a slight fog, but there is no problem in actual use.
X: The density of the solid image is thin and there is much fogging.

  From the above results, in contrast to Comparative Examples 1 to 6, in Examples 1 to 6, the crystalline polyester having a very low low molecular weight component is used as the binder resin. It can be seen that an excellent toner can be efficiently produced.

  The crystalline polyester for toner of the present invention is used as a binder resin for a toner used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method or the like.

Claims (5)

Molecular weight is not less than 3% by weight content of 1000 following components, the ratio of the maximum peak temperature of heat of fusion softening point (softening point / peak temperature) Ru der 0.6 to 1.3 binding-crystalline polyester And a toner containing amorphous polyester . Carboxylic acid in which the crystalline polyester contains 80 mol% or more of an alcohol component containing 80 mol% or more of 1,4-butanediol and 1,6-hexanediol and an aliphatic dicarboxylic acid compound having 2 to 8 carbon atoms The toner according to claim 1, which is obtained by condensation polymerization of components. The toner according to claim 1, wherein the content of a component having a molecular weight of 500 or less is 1% by weight or less in the crystalline polyester. The toner according to claim 1, wherein the crystalline polyester is obtained by washing a polymer obtained by condensation polymerization of an alcohol component and a carboxylic acid component with dioxane and / or tetrahydrofuran. The method for producing a crystalline polyester for toner according to any one of claims 1 to 3, further comprising a step of washing a polymer obtained by condensation polymerization of an alcohol component and a carboxylic acid component with dioxane and / or tetrahydrofuran.