JP4680039B2 - toner - Google Patents

Description

  The present invention relates to a toner used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method or the like.

As the machine speeds up and saves energy, there is a need for toner with excellent low-temperature fixability. On the other hand, with the increase in speed, there is a need for toner that has both anti-offset properties that conflict with low-temperature fixability. Has been. In order to achieve both of these properties, a rosin monomer is used in the polyester (see Patent Document 1), and a method of blending a low molecular weight resin and a high molecular weight resin is used (see Patent Document 2). ).
JP-A-4-70765 Japanese Patent Laid-Open No. 2-82267

  However, the method of blending a low molecular weight resin and a high molecular weight resin has the disadvantage that it is inferior in grindability in the resin production process due to the presence of the high molecular weight component and in the grind toner production process using the binder resin. Have. On the other hand, in the method using only a low molecular weight resin, not only is it inferior in offset resistance and storage stability, but also the problem that the resin is fused during pulverization because the grindability is too good and the productivity is inferior. Occurs.

  Furthermore, although the rosin monomer used in Patent Document 1 is effective in improving the low-temperature fixability, it also has a drawback that odor is likely to occur.

  An object of the present invention is to provide a toner that is excellent in all of low-temperature fixability, storability, and pulverization properties, and that reduces odor generation.

  The present invention is a toner comprising a binder resin and a colorant, wherein the binder resin comprises a polyester (A) having a softening point of 120 to 160 ° C. and a softening point of 80 ° C. or higher and lower than 120 ° C. The present invention relates to a toner comprising polyester (B), wherein polyester (B) is a polyester obtained by condensation polymerization of an alcohol component and a carboxylic acid component containing purified rosin.

  The toner of the present invention is excellent in both low-temperature fixability and grindability, and has an excellent effect of reducing the generation of odor.

  The toner of the present invention contains at least a binder resin and a colorant, and the binder resin includes two kinds of polyesters having a specific softening point, that is, polyester (A) and polyester (B) shown below. It contains.

  Polyester (A) is a polyester having a softening point of 120 to 160 ° C, preferably 130 to 155 ° C, more preferably 135 to 155 ° C, while polyester (B) has a softening point of 80 ° C or higher and lower than 120 ° C. The polyester is preferably 85 to 115 ° C, more preferably 90 to 110 ° C. Polyester (A) with a high softening point contributes to improvement in offset resistance, while polyester (B) with a low softening point contributes to improvement in low-temperature fixability, and the combined use of both polyesters achieves both low-temperature fixability and offset resistance. It is effective for. The weight ratio of polyester (A) to polyester (B) in the binder resin (polyester (A) / polyester (B)) is preferably 1/9 to 9/1, more preferably 2/8 to 8/2. 3/7 to 7/3 is more preferable.

  Furthermore, the present invention is greatly characterized in that the polyester (B) is a polyester obtained by condensation polymerization of an alcohol component and a carboxylic acid component containing a purified rosin. It is surprising that the purified rosin further improves the low-temperature fixability of the polyester (B) and increases the pulverization property of the resin, but also does not cause fusion due to excessive pulverization, thereby increasing production efficiency and reducing odor. An effect is produced. The reason why the odor is reduced and the storage stability is improved is that impurities in the rosin are reduced by purification. In addition, it is speculated that the crystallization of rosin is promoted by purification.

  Rosin is a natural resin obtained from pine, and its main component is resin acids such as abietic acid, neoabietic acid, parastrinic acid, pimaric acid, isopimaric acid, sandaracopimaric acid, dehydroabietic acid and the like. It is a mixture.

  Rosin is roughly divided into tall rosin obtained from tall oil obtained as a by-product in the process of producing pulp, gum rosin obtained from raw pine ani, wood rosin obtained from pine stumps, etc. From the viewpoint of low-temperature fixability, purified tall rosin is preferable.

  In addition, a purified product of a modified rosin such as a disproportionated rosin or a hydrogenated rosin can be used, but in the present invention, a so-called raw rosin that is not modified is used from the viewpoint of low-temperature fixability and storage stability. It is preferable to do.

  The purified rosin in the present invention is a rosin from which impurities have been removed by a purification process. Main impurities include 2-methylpropane, acetaldehyde, 3-methyl-2-butanone, 2-methylpropanoic acid, butanoic acid, pentanoic acid, n-hexanal, octane, hexanoic acid, benzaldehyde, 2-pentylfuran, 2 , 6-dimethylcyclohexanone, 1-methyl-2- (1-methylethyl) benzene, 3,5-dimethyl-2-cyclohexene, 4- (1-methylethyl) benzaldehyde and the like. In the present invention, among these, the peak intensity detected as a volatile component by the headspace GC-MS method of three types of impurities, 2-methylpropane, pentanoic acid and benzaldehyde, can be used as an indicator of purified rosin. . The reason why the volatile component rather than the absolute amount of impurities is used as an indicator is that the present invention makes odor one of the problems of improvement with respect to the conventional polyester using rosin.

That is, the purified rosin in the present invention has a peak intensity of hexanoic acid of 0.8 × 10 ⁷ or less and a peak intensity of pentanoic acid of 0.4 × 10 ⁷ or less under the measurement conditions of the headspace GC-MS method described later. Rosin having a peak intensity of benzaldehyde of 0.4 × 10 ⁷ or less. Furthermore, from the viewpoint of storage stability and odor, the peak intensity of hexanoic acid is preferably 0.6 × 10 ⁷ or less, and more preferably 0.5 × 10 ⁷ or less. The peak intensity of pentanoic acid is preferably 0.3 × 10 ⁷ or less, and more preferably 0.2 × 10 ⁷ or less. The peak intensity of benzaldehyde is preferably 0.3 × 10 ⁷ or less, and more preferably 0.2 × 10 ⁷ or less.

Further, from the viewpoint of storage stability and odor, it is preferable that n-hexanal and 2-pentylfuran are reduced in addition to the above three substances. The peak intensity of n-hexanal is preferably 1.7 × 10 ⁷ or less, more preferably 1.6 × 10 ⁷ or less, and further preferably 1.5 × 10 ⁷ or less. The peak intensity of 2-pentylfuran is preferably 1.0 × 10 ⁷ or less, more preferably 0.9 × 10 ⁷ or less, and further preferably 0.8 × 10 ⁷ or less.

  As a purification method of rosin, known methods can be used, and methods such as distillation, recrystallization, extraction and the like can be mentioned, and purification by distillation is preferable. As the distillation method, for example, the method described in JP-A-7-286139 can be used, and examples thereof include vacuum distillation, molecular distillation, steam distillation, etc., but purification by vacuum distillation is preferable. For example, distillation is usually performed at a still temperature of 200 to 300 ° C. at a pressure of 6.67 kPa or less, and methods such as ordinary simple distillation, thin film distillation, rectification, etc. are applied. On the other hand, 2 to 10% by weight of a high molecular weight substance is removed as a pitch component, and at the same time, 2 to 10% by weight of an initial fraction is simultaneously removed.

  The softening point of the purified rosin is preferably 50 to 100 ° C, preferably 60 to 90 ° C, and more preferably 65 to 85 ° C. Further, the impurities contained in the rosin are removed by purification. The softening point of the purified rosin in the present invention means the softening point measured when the rosin is once melted and naturally cooled in an environment of a temperature of 25 ° C. and a relative humidity of 50% for 1 hour by the method described later. To do.

  Further, the acid value of the purified rosin is preferably 100 to 200 mgKOH / g, more preferably 130 to 180 mgKOH / g, and further preferably 150 to 170 mgKOH / g.

  The content of the purified rosin is preferably 2 to 50 mol%, more preferably 5 to 40 mol%, further preferably 10 to 30 mol% in the carboxylic acid component.

  Carboxylic acid components other than purified rosin include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, n-dodecyl succinic acid, n -Aliphatic dicarboxylic acids such as dodecenyl succinic acid; Aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid; Cycloaliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid; Carboxylic acids; and anhydrides of these acids, alkyl (C1-3) esters, and the like. Such acids, anhydrides of these acids, and alkyl esters of these acids are collectively referred to herein as carboxylic acid compounds.

  The alcohol component of the polyester (B) has the formula (I):

(In the formula, RO is an alkylene oxide, R is an alkylene group having 2 or 3 carbon atoms, x and y are positive numbers indicating the average added mole number of alkylene oxide, and the sum of x and y is 1 to 16) , Preferably 1-8, more preferably 1.5-4)
It is preferable that the alkylene oxide addition product of bisphenol A represented by these is contained.

  Examples of alkylene oxide adducts of bisphenol A represented by the formula (I) include polyoxypropylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis Examples include alkylene (2 to 3 carbon) oxide (average number of added moles 1 to 16) adducts of bisphenol A such as (4-hydroxyphenyl) propane.

  The content of the compound represented by the formula (I) is preferably 80 mol% or more, more preferably 100 mol% in the alcohol component of the polyester (B).

  Other alcohol components include ethylene glycol, propylene glycol, glycerin, pentaerythritol, trimethylolpropane, hydrogenated bisphenol A, sorbitol, or their alkylene (2 to 4 carbon atoms) oxide (average number of added moles of 1 to 16). Examples include adducts.

  The polycondensation of the alcohol component and the carboxylic acid component of the polyester (B) is preferably performed in the presence of an esterification catalyst. Preferable examples of the esterification catalyst in the present invention include a titanium compound and a tin (II) compound having no Sn-C bond, and these are used alone or in combination.

  As a titanium compound, the titanium compound which has a Ti-O bond is preferable, and the compound which has a C1-28 total carbon number alkoxy group, an alkenyloxy group, or an acyloxy group is more preferable.

Specific examples of the titanium compound include titanium diisopropylate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₃ H ₇ O) ₂ ], titanium diisopropylate bisdiethanolamate [Ti (C ₄ H ₁₀ O ₂ N) ₂ (C ₃ H ₇ O) ₂ ], titanium dipentylate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₅ H ₁₁ O) ₂ ], titanium diety rate bis triethanolaminate _{[Ti (C 6 H 14 O 3} N) 2 (C 2 H 5 O) 2 ], titanium dihydroxy octylate bis triethanolaminate _{[Ti (C 6 H 14 O 3} N) 2 (OHC 8 H ₁₆ O) ₂ ], titanium distearate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₁₈ H ₃₇ O) ₂ ], titanium triisopropylate triethanolamate [Ti (C _{6 H 14 O 3 N) 1 (} C 3 ₇ O) _3], titanium monopropylate tris (triethanolaminate) _{[Ti (C 6 H 14 O 3} N) 3 (C 3 H 7 O) 1 ], and the like, titanium diisopropylate Among these Preferred are rate bistriethanolamate, titanium diisopropylate bisdiethanolamate, and titanium dipentylate bistriethanolamate, which are also commercially available, for example, from Matsumoto Trading Co., Ltd.

Specific examples of other preferable titanium compounds include tetra-n-butyl titanate [Ti (C ₄ H ₉ O) ₄ ], tetrapropyl titanate [Ti (C ₃ H ₇ O) ₄ ], tetrastearyl titanate [Ti ( C ₁₈ H ₃₇ O) ₄ ], tetramyristyl titanate [Ti (C ₁₄ H ₂₉ O) ₄ ], tetraoctyl titanate [Ti (C ₈ H ₁₇ O) ₄ ], dioctyl dihydroxyoctyl titanate [Ti (C ₈ H ₁₇ O) ₂ (OHC ₈ H ₁₆ O) ₂ ], dimyristyl dioctyl titanate [Ti (C ₁₄ H ₂₉ O) ₂ (C ₈ H ₁₇ O) ₂ ] and the like. Among these, tetrastearyl titanate, tetra Myristyl titanate, tetraoctyl titanate and dioctyl dihydroxy octyl titanate are preferred, for example by reacting a titanium halide with the corresponding alcohol. However, it can also be obtained as a commercial product such as Nisso.

  The abundance of the titanium compound is preferably 0.01 to 1.0 part by weight, more preferably 0.1 to 0.5 part by weight, based on 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.

  Examples of the tin (II) compound having no Sn—C bond include a tin (II) compound having a Sn—O bond, a tin (II) compound having a Sn—X (X represents a halogen atom) bond, and the like. Preferably, a tin (II) compound having a Sn-O bond is more preferable.

Examples of the tin (II) compound having an Sn-O bond include tin (II) oxalate, tin (II) diacetate, tin (II) dioctanoate, tin (II) dilaurate, tin (II) distearate, diolein Tin (II) carboxylate having a carboxylic acid group having 2 to 28 carbon atoms such as tin (II) acid; dioctyloxy tin (II), dilauroxy tin (II), distearoxy tin (II), dioleoxy tin (II), etc. Dialkoxytin (II) having an alkoxy group having 2 to 28 carbon atoms; tin (II) oxide; tin (II) sulfate and the like having a Sn—X (X represents a halogen atom) bond include chloride. Tin (II), tin (II) halides such as tin (II), and the like can be mentioned. Among these, (R ¹ COO) ₂ Sn (where R ¹ represents a fatty acid tin (II) represented by an alkyl group or an alkenyl group having 5 to 19 carbon atoms, and (R ² O) ₂ Sn (where R ² is 6 to ² carbon atoms) A dialkoxytin (II) represented by 0 (which represents an alkyl group or an alkenyl group) and a tin (II) oxide represented by SnO, and a fatty acid tin (II) represented by (R ¹ COO) ₂ Sn And tin oxide (II) is more preferable, and tin (II) dioctanoate, tin (II) distearate and tin (II) oxide are more preferable.

  The existing amount of the tin (II) compound is preferably 0.01 to 1.0 part by weight, and more preferably 0.1 to 0.5 part by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.

  When the titanium compound and the tin (II) compound are used in combination, the total amount of the titanium compound and the tin (II) compound is preferably 0.01 to 1.0 part by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component, 0.1-0.5 weight part is more preferable.

  The polycondensation of the alcohol component and the carboxylic acid component can be performed, for example, at a temperature of 180 to 250 ° C. in an inert gas atmosphere in the presence of the esterification catalyst.

  The polyester (A) is also obtained by condensation polymerization of a known alcohol component and a carboxylic acid component, except that the obtained polyester has a different softening point. Preferably, the alcohol component and the carboxylic acid component are the same as the polyester (B). Can be obtained by condensation polymerization in the presence of a titanium compound and / or a tin (II) compound having no Sn-C bond. The softening point of the polyester can be adjusted by the reaction time.

  The glass transition points of the polyesters (A) and (B) are preferably 45 to 75 ° C, more preferably 50 to 65 ° C, from the viewpoints of fixability, storage stability and durability. The acid value is preferably 1 to 80 mgKOH / g, more preferably 10 to 50 mgKOH / g, from the viewpoints of chargeability and environmental stability.

  The polyesters (A) and (B) may be modified polyesters. Modified polyester refers to polyester grafted or blocked with phenol, urethane or the like.

  In the binder resin, other known resins such as vinyl resins such as styrene-acrylic resins, epoxy resins, polycarbonates, and polyurethanes are used in combination as long as the effects of the present invention are not impaired. However, the total content of polyester (A) and polyester (B) is preferably 70% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more in the binder resin. More preferably, it is 100% by weight.

  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 the toner of the present invention may be either a black toner or a color toner. The content of the colorant is preferably 1 to 40 parts by weight and more preferably 2 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

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

The toner of the present invention may be a toner obtained by any conventionally known method such as a melt-kneading method, an emulsion phase inversion method, or a polymerization method, but from the viewpoint of productivity and dispersibility of the colorant, A pulverized toner obtained by a melt kneading method is preferred. In the case of pulverized toner by melt kneading method, raw materials such as binder resin, colorant, charge control agent, etc. are uniformly mixed with a mixer such as a Henschel mixer, then a sealed kneader, a single or twin screw extruder, open It can be produced by melt-kneading with a roll-type kneader or the like, cooling, pulverizing and classifying. The volume median particle size (D ₅₀ ) of the toner is preferably 3 to 15 μm. In the present specification, the volume-median particle size (D ₅₀ ) means a particle size at which the cumulative volume frequency calculated by the volume fraction is 50% when calculated from the smaller particle size.

  The toner of the present invention can be used as a one-component developing toner or as a two-component developer mixed with a carrier.

[Softening point of resin]
Using a flow tester (Shimadzu Corporation, CFT-500D), a 1 g sample is heated at a heating rate of 6 ° C / min, and a 1.96 MPa load is applied by a plunger and extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. . The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[Softening point of rosin]
(1) Sample preparation 10g of rosin is melted on a hot plate at 170 ° C for 2 hours. After that, it is naturally cooled for 1 hour in an open state at a temperature of 25 ° C. and a relative humidity of 50%, and then ground for 10 seconds in a coffee mill (National MK-61M).
(2) Measurement Using a flow tester (Shimadzu Corporation, CFT-500D), a 1g sample was heated at a heating rate of 6 ° C / min, and a load of 1.96MPa was applied by a plunger, with a diameter of 1mm and a length of 1mm. Extrude from nozzle. The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[Glass transition point of resin]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), weigh 0.01 to 0.02 g of the sample into an aluminum pan, raise the temperature to 200 ° C, and from that temperature to 0 ° C at a rate of 10 ° C / min. The temperature of the cooled sample is raised at a heating rate of 10 ° C / min, and the temperature at the intersection of the base line extension below the maximum peak temperature of endotherm and the tangent that indicates the maximum slope from the peak rise to the peak apex To do.

[Acid value of resin and rosin]
Measure according to the method of JIS K0070.

[Volume-median particle diameter of toner (D ₅₀ )]
Measuring machine: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 100 μm
Measurement particle size range: 2-60μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter)
Electrolyte: Isoton II (Beckman Coulter, Inc.)
Dispersion: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB: 13.6) 5% electrolyte dispersion condition: 10 mg of a measurement sample is added to 5 ml of dispersion, and dispersed for 1 minute with an ultrasonic disperser. Then, 25 ml of the electrolytic solution is added, and further dispersed with an ultrasonic disperser for 1 minute.
Measurement conditions: Add 100 ml of electrolyte and dispersion into a beaker, measure 30,000 particles at a concentration that can measure the particle size of 30,000 particles in 20 seconds, and determine the volume-median particle size ( determine the D _50).

Example of purification of rosin 1000 g of tall rosin was added to a 2000 ml-distillation flask equipped with a fractionation tube, reflux condenser and receiver, and distilled at a reduced pressure of 13.3 kPa or 1 kPa. Was collected as the main fraction. The rosin before purification was rosin A, the main fraction of distillation performed under a reduced pressure of 13.3 kPa was rosin B, and the main fraction of distillation performed under a reduced pressure of 1 kPa was used as rosin C. .

  20 g of rosin was pulverized for 5 seconds with a coffee mill (National MK-61M), and 0.5 g was measured in a headspace vial (20 ml) after passing through a 1 mm sieve. Table 1 shows the results of sampling the headspace gas and analyzing the impurities in the rosins A to C by the headspace GC-MS method.

[Measurement conditions for headspace GC-MS method]
A. Headspace sampler (Agilent, HP7694)
Sample temperature: 200 ℃
Loop temperature: 200 ° C
Transfer line temperature: 200 ° C
Sample heating equilibration time: 30min
Bayal pressurized gas: Helium (He)
Bayal pressurization time: 0.3min
Loop filling time: 0.03min
Loop equilibration time: 0.3min
Injection time: 1min

B. GC (Gas Chromatography) (Agilent, HP6890)
Analytical column: DB-1 (60m-320μm-5μm)
Carrier: Helium (He)
Flow rate condition: 1ml / min
Inlet temperature: 210 ° C
Column head pressure: 34.2kPa
Injection mode: split
Split ratio: 10: 1
Oven temperature condition: 45 ℃ (3min) -10 ℃ / min-280 ℃ (15min)

C. MS (mass spectrometry) (Agilent, HP5973)
Ionization method: EI (electron impact) method Interface temperature: 280 ℃
Ion source temperature: 230 ° C
Quadrupole temperature: 150 ° C
Detection mode: Scan 29-350m / s

Resin production example 1
Put the alcohol component, carboxylic acid component other than trimellitic anhydride and esterification catalyst shown in Table 2 into a 5 liter four-necked flask equipped with a nitrogen introduction tube, dehydration tube, stirrer and thermocouple, and a nitrogen atmosphere. Then, the polycondensation reaction was performed at 230 ° C. until the reaction rate (the amount of generated water / theoretical water amount × 100) reached 90%, and then the reaction was performed at 230 ° C. and 8.0 kPa for 1 hour. After cooling to 220 ° C, trimellitic anhydride was added and reacted at normal pressure for 1 hour, and then the reaction was carried out at 220 ° C and 20 kPa until the desired softening point was reached. Resins H-1, H- 3, L-1 to L-3, L-5 to L-7 were obtained.

Resin production example 2
Put the alcohol component, carboxylic acid component other than trimellitic anhydride and esterification catalyst shown in Table 2 into a 5 liter four-necked flask equipped with a nitrogen introduction tube, dehydration tube, stirrer and thermocouple, and a nitrogen atmosphere. Then, the temperature was raised stepwise from 185 ° C. to 210 ° C. over 5 hours, and then trimellitic anhydride was added. Reaction was carried out at 210 ° C. for 1 hour, and reaction was carried out at 210 ° C. and 10 kPa until a desired softening point was reached, to obtain a resin H-2.

Resin production example 3
The alcohol component, carboxylic acid component, and esterification catalyst shown in Table 2 were placed in a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and 185 ° C to 210 ° C under a nitrogen atmosphere. After the temperature was raised stepwise to 5 ° C. over 5 hours, the reaction was carried out at 210 ° C. and 10 kPa until the desired softening point was reached to obtain Resin L-4.

Examples 1-9 and Comparative Examples 1-4
Binder resin shown in Table 3, carbon black "MOGUL L" (Cabot) 4 parts by weight, negative charge control agent "Bontron S-34" (Orient Chemical Industries) 1 part and polypropylene wax "NP" -105 "(Mitsui Chemicals Co., Ltd.) 1 part by weight was thoroughly mixed with a Henschel mixer, then melt-kneaded at a roll rotation speed of 200 r / min and a heating temperature in the roll of 80 ° C using a co-rotating twin screw extruder. did. The obtained melt-kneaded product was cooled and coarsely pulverized, then pulverized with a jet mill and classified to obtain a powder having a volume median particle size (D ₅₀ ) of 8.0 μm.

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

Test Example 1 [low temperature fixability]
The toner is mounted on the printer “Page Presto N-4” (Casio Computer Co., Ltd., fixing: contact fixing method, developing method: non-magnetic one-component developing method, developing roll diameter: 2.3 cm), and the toner adhesion amount is 0.6 mg / An unfixed image was obtained by adjusting to cm ² . The fixing machine (fixing speed: 200mm / s) was improved so that the fixing machine of the AR-505 (Sharp Corporation) contact fixing type copier can be fixed outside the machine. The fixing roll was fixed by fixing the unfixed image while increasing the temperature of the fixing roll from 100 ° C. to 240 ° C. by 10 ° C.

  The image obtained at each fixing temperature was pasted with `` UNICEF Cellophane '' (Mitsubishi Pencil Co., Ltd., width 18 mm, JISZ-1522), passed through the fixing roll of the fixing machine set to 30 ° C., and then the tape was applied. The optical reflection density before and after peeling and tape peeling was measured using a reflection densitometer “RD-915” (manufactured by Macbeth). The fixing roller temperature at which the ratio between the two (after peeling / before peeling) first exceeded 90% 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 3.

〔Evaluation criteria〕
◎: Minimum fixing temperature 150 ° C or less ○: Minimum fixing temperature 160 ° C or more, 170 ° C or less ×: Minimum fixing temperature 180 ° C or more

Test Example 2 [Crushability]
The binder resins having the combinations shown in Table 3 used in Examples and Comparative Examples were coarsely crushed and sieved, passed through a 16 mesh (opening: 1 mm) sieve, and passed through a 22 mesh (opening: 710 μm) sieve. Not obtained resin powder. 10.00g of this classified resin powder is precisely weighed, pulverized for 30 seconds with a mill & mixer MM-I type (manufactured by Hitachi Living Supply Co., Ltd.), passed through a sieve of 30 mesh (aperture: 500 μm), and does not pass The weight (A) g of the resin was precisely weighed, the residual ratio was determined by the following formula, this operation was performed three times, and the averaged value was used as the grindability index.
Residual rate = (A) / resin weight before grinding (10.00 g) × 100

〔Evaluation criteria〕
◎: Grindability index is less than 5 ○: Grindability index is 5 or more and less than 15 ×: Grindability index is 15 or more

Test Example 3 [Preservability]
4 g of toner was placed in an open cylindrical container having a diameter of 5 cm and a height of 2 cm, and left for 72 hours in an environment of a temperature of 40 ° C. and a relative humidity of 60%. After leaving, the container containing the toner was shaken lightly, and the presence or absence of toner aggregation was visually observed, and the storage stability was evaluated according to the following evaluation criteria. The results are shown in Table 3.

〔Evaluation criteria〕
A: No aggregation of toner is observed.
○: Slightly aggregated toner particles are observed.
X: Aggregation is clearly observed.

Test Example 4 [Odor]
20 g of toner was weighed into an aluminum cup and allowed to stand on a hot plate heated to 150 ° C. for 30 minutes, and the odor generated from the toner was evaluated according to the following evaluation criteria. The results are shown in Table 3.

〔Evaluation criteria〕
A: No odor is felt.
○: Almost no odor is felt.
X: Odor is felt strongly.

  From the above results, it can be seen that the toners of the examples have good results in all of the low-temperature fixability, grindability, storage stability and odor as compared with the toner of the comparative example. In Comparative Example 1, since only a high molecular weight material is used, the low temperature fixability and grindability are inferior. In Comparative Example 2, since purified rosin is used, the low temperature fixability and storage stability are excellent, but the resin has a low softening point. Fusion has occurred. In particular, the toner of Comparative Example 3 containing a resin not using rosin has insufficient low-temperature fixability, and the toner of Comparative Example 4 containing a resin using unpurified rosin is pulverizable and stored. It turns out that it lacks in nature and generates odor.

  The toner of the present invention is used for developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method and the like.

Claims (7)

A toner comprising a binder resin and a colorant, wherein the binder resin comprises a polyester (A) having a softening point of 120 to 160 ° C. and a polyester (B) having a softening point of 80 ° C. or higher and lower than 120 ° C. In the measurement conditions of the headspace GC-MS method, the peak intensity of hexanoic acid is 0.8 × 10 ⁷ or less, and the peak intensity of pentanoic acid is 0.4 × 10 6. ^A toner which is a polyester obtained by polycondensation with a carboxylic acid component containing a purified rosin having a peak intensity of benzaldehyde of not more than ⁷ and a benzaldehyde peak of not more than 0.4 × 10 ⁷ . The alcohol component of the polyester (B) is represented by the formula (I):

(In the formula, RO is an alkylene oxide, R is an alkylene group having 2 or 3 carbon atoms, x and y are positive numbers indicating the average added mole number of alkylene oxide, and the sum of x and y is 1 to 16) Is)
The toner according to claim 1, comprising 80 mol% or more of an alkylene oxide adduct of bisphenol A represented by the formula:   The toner according to claim 1 or 2, wherein the purified rosin has a softening point of 50 to 100 ° C.   The toner according to claim 1, wherein the purified rosin is a purified tall rosin.   The toner according to claim 1, wherein the content of the purified rosin is 2 to 50 mol% in the carboxylic acid component of the polyester (B).   The polycondensation of the alcohol component and the carboxylic acid component of the polyester (B) is carried out in the presence of a titanium compound and / or a tin (II) compound having no Sn-C bond. toner.   The toner according to any one of claims 1 to 6, wherein a weight ratio of the polyester (A) and the polyester (B) in the binder resin (polyester (A) / polyester (B)) is 1/9 to 9/1.