JP2008020553A - Electrophotographic toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic toner excellent in mold releasability and developability even when an alkylene bis-fatty acid amide is contained. <P>SOLUTION: The electrophotographic toner contains a polyester-containing binder resin, a clay organic complex obtained by intercalating a quaternary ammonium salt into a clay mineral, and an alkylene bis-fatty acid amide, wherein a content of the clay organic complex is 0.05-5 wt.% in the toner. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

The performance required for the toner includes releasability at the time of fixing. In order to improve releasability, use of waxes such as polyethylene and polypropylene can be mentioned (see Patent Document 1). In addition, amide waxes represented by alkylene bis-fatty acid amides such as ethylene bisstearamide can be expected to be effective as mold release agents (see Patent Document 2).
JP 2006-119208 A Japanese Patent Laid-Open No. 10-301325

  However, waxes such as polyethylene and polypropylene have disadvantages such as filming due to the formation of domains due to poor compatibility with binder resins, particularly polyesters. Amide waxes typified by alkylene bis fatty acid amides such as amides have a problem of poor exudation during fixing because they are too compatible with polyester.

  An object of the present invention is to provide an electrophotographic toner excellent in releasability and developability even when an alkylene bis fatty acid amide is contained.

  The present invention relates to a toner for electrophotography comprising a binder resin containing polyester, a clay organic composite obtained by intercalating a quaternary ammonium salt with a clay mineral, and an alkylene bis fatty acid amide, The present invention relates to an electrophotographic toner in which the content of the clay organic complex is 0.05 to 5% by weight in the toner.

  Even if the toner for electrophotography of the present invention contains an alkylene bis-fatty acid amide, the toner exhibits excellent effects in releasability and developability.

  The toner for electrophotography of the present invention contains a binder resin containing polyester, a clay organic composite obtained by intercalating a quaternary ammonium salt with a clay mineral, and an alkylene bis fatty acid amide, The organic composite content is 0.05 to 5% by weight in the toner. By using the clay organic composite in combination, the alkylene bis fatty acid amide exhibits performance as a release agent. I found a thing. Although the detailed reason is unknown, it is considered that the property of the polyester is adjusted by the clay organic composite and the compatibility with the alkylene bis-fatty acid amide is lowered. It is effective for a toner using a crystalline polyester that is liable to cause such a problem.

  As the binder resin, it is preferable to contain polyester, and in particular, to contain crystalline polyester. The crystallinity of polyester is represented by the ratio between the softening point and the highest endothermic peak temperature measured by a differential scanning calorimeter, that is, the crystallinity index defined by the softening point / the highest endothermic peak temperature. Generally, when this value exceeds 1.5, the resin is amorphous, and when it is less than 0.6, the crystallinity is low and there are many amorphous parts. The crystallinity of the resin can be adjusted by the type and ratio of the raw material monomers, production conditions (for example, reaction temperature, reaction time, cooling rate) and the like. For example, crystallization of polyester can be promoted by combining aliphatic alcohols and aliphatic carboxylic acid compounds having a similar short molecular chain and relatively easily arranged as a raw material monomer. Further, the maximum peak temperature of endotherm tends to be higher as the resin has higher crystallinity, and can be adjusted, for example, by the ratio of the monomer that promotes crystallization or the monomer that promotes non-crystallization. The maximum peak temperature of endotherm refers to the peak temperature on the highest temperature side among the observed endothermic peaks. If the maximum peak temperature is within 20 ° C. from the softening point, the melting point is set, and the peak having a difference from the softening point exceeding 20 ° C. is a peak due to glass transition.

  The crystalline polyester in the present invention refers to those having a crystallinity index of 0.6 to 1.5. The crystallinity index of the crystalline polyester is preferably 0.8 to 1.3, more preferably 0.85 to 1.10, and still more preferably 0.90 to 1.05, from the viewpoint of low-temperature fixability. In addition, the amorphous polyester in the present invention refers to a resin having a crystallinity index greater than 1.5 or less than 0.6, preferably greater than 1.5.

  Both the crystalline polyester and the amorphous polyester are obtained by polycondensing a raw material monomer with an alcohol component composed of a divalent or higher alcohol and a carboxylic acid component composed of a divalent or higher carboxylic acid compound.

  As the dihydric or higher alcohol, from the viewpoint of the storage stability of the toner, 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 number of moles added of alkylene oxide, and the sum of x and y is 1-16. (Preferably 1.5 to 5)
An alkylene oxide adduct of bisphenol A represented by The content of the alkylene oxide adduct of bisphenol A is preferably 50 mol% or more, more preferably 60 mol% or more, and further preferably 80 mol% or more in the alcohol component.

  Examples of the alkylene oxide adduct of bisphenol A represented by the formula (I) include polyoxyethylene-2,2-bis (4-hydroxyphenyl) propane and other ethylene oxide adducts having 2 carbon atoms, such as polyoxypropylene Examples thereof include propylene oxide adducts having 3 carbon atoms, such as -2,2-bis (4-hydroxyphenyl) propane, and it is preferable to use at least both an ethylene oxide adduct and a propylene oxide adduct.

  Examples of alcohol components other than the bisphenol A alkylene oxide adduct include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexane. Examples include diol, 1,4-butenediol, neopentyl glycol, polyethylene glycol, polypropylene glycol, bisphenol A, hydrogenated bisphenol A, sorbitol, pentaerythritol, glycerol, and trimethylolpropane.

  Among these alcohol components, the alcohol components that promote crystallization of polyester include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1 2, aliphatic diols having 2 to 6 carbon atoms such as 4-butenediol.

  Examples of the divalent or higher carboxylic acid compound include oxalic acid, malonic acid, adipic acid, fumaric acid, maleic acid, succinic acid (for example, n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid). Aliphatic carboxylic acids such as acid, isooctenyl succinic acid, isooctyl succinic acid and the like, or succinic acid substituted with an alkenyl group having 2 to 20 carbon atoms, phthalic acid, isophthalic acid, terephthalic acid, etc. Acids, 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid and other aromatic carboxylic acids, and anhydrides and lower alkyls of these acids (carbon number) 1-3) Ester etc. are mentioned. Such acids, anhydrides of these acids, and alkyl esters of these acids are collectively referred to herein as carboxylic acid compounds.

  In these carboxylic acid components, at least one selected from the group consisting of phthalic acid, terephthalic acid and isophthalic acid is preferable, and terephthalic acid is more preferable, from the viewpoint of increasing the hardness of the resin and improving developability.

  The polyester is preferably a crosslinked polyester obtained using a trivalent or higher monomer as the alcohol component and / or carboxylic acid component from the viewpoint of the softening point and grindability. The content of the trivalent or higher monomer is preferably 2 to 20 mol%, more preferably 4 to 18 mol% in the total amount of the alcohol component and the carboxylic acid component. As the trivalent or higher monomer, 1,2,4-benzenetricarboxylic acid (trimellitic acid) and its anhydride are preferable.

  The alcohol component may contain a monovalent alcohol, and the carboxylic acid component may contain a monovalent carboxylic acid compound as appropriate from the viewpoints of molecular weight adjustment and offset resistance improvement.

  The polyester is obtained by polycondensing an alcohol component and a carboxylic acid component, for example, in an inert gas atmosphere, if necessary, in the presence of an esterification catalyst. The reaction temperature is preferably 120 to 230 ° C. in the production of crystalline polyester, 150 to 280 ° C. is preferred in the production of amorphous polyester, and 200 to 250 ° C. is more preferred.

  The softening point of the crystalline polyester is preferably 70 to 150 ° C, more preferably 90 to 130 ° C.

  The softening point of the amorphous polyester is preferably 80 to 160 ° C, more preferably 90 to 150 ° C. The glass transition point is preferably 50 to 75 ° C, more preferably 53 to 65 ° C, from the viewpoint of improving developability.

  The acid value of the crystalline polyester and the amorphous polyester is preferably 3 to 40 mgKOH / g.

  In the present invention, the polyester may be a polyester modified to such an extent that the characteristics are not substantially impaired. Examples of the modified polyester include grafting and blocking with phenol, urethane, epoxy and the like by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, and the like. Polyester.

  Furthermore, in the toner of the present invention, in addition to polyester, other binder resins may be appropriately contained as long as the effects of the present invention are not impaired. Examples of other binder resins include vinyl resins such as styrene-acrylic resins, epoxy resins, polycarbonates, polyurethanes, and hybrid resins having two or more resin components. The content of the polyester is not particularly limited, but is preferably 50 to 100% by weight, more preferably 70 to 100% by weight in the binder resin from the viewpoint of improving the dispersibility of the alkylene bis fatty acid amide in the binder resin. More preferably, substantially 100% by weight.

  Further, the content of the crystalline polyester is preferably 3 to 40% by weight, more preferably 5 to 25% by weight in the polyester, from the viewpoint of improving the low-temperature fixability.

  The clay organic composite can be obtained by intercalating a quaternary ammonium salt with a clay mineral.

  Examples of the clay mineral include kaolin mineral, mica type clay mineral, and smectite type clay mineral. From the viewpoint of improving releasability, the smectite type clay mineral is preferable.

  The smectite type clay minerals include natural smectite type clays such as hectorite, saponite, stevensite, beidellite, montmorillonite, nontronite, bentonite, chemically synthesized synthetic smectite type clays, substitutions and derivatives thereof, and these A mixture etc. are mentioned.

  The smectite-type clay mineral contains at least three elements selected from the group consisting of magnesium (Mg), lithium (Li), silicon (Si) and aluminum (Al) from the viewpoint of improving releasability. Is preferable, and it is more preferable to contain Mg, Li, and Si.

  The cation exchange capacity of the smectite-type clay mineral is preferably 70 milliequivalents or more, more preferably 85 to 130 milliequivalents per 100 g of clay.

  The content of non-clay impurities in the clay mineral used in the present invention is preferably 10% by weight or less.

A quaternary ammonium salt has the formula (A):
[(R ¹ ) _r (R ² ) _s (R ³ ) _t N] ⁺ · X ⁻ (A)
(In the formula, R ¹ and R ² are not the same, R ¹ is an alkyl group, an alkenyl group or an alkynyl group having 4 to 24 carbon atoms, and R ² is an alkyl group having 1 to 10 carbon atoms or a carbon number. An alkenyl group or an alkynyl group having 2 to 10; R ³ is a phenyl group or an arylalkyl group having 7 to 10 carbon atoms; and r, s, and t are r + s + t = 4, r ≧ 1, s ≧ 1 represents an integer satisfying t ≧ 0, and X ⁻ represents an anion)
The compound represented by these is preferable.

The carbon number of the alkyl group, alkenyl group or alkynyl group represented by R ¹ is preferably 4 to 24, more preferably 6 to 20, and still more preferably 8 to 18.

Carbon number of the alkyl group represented by R ² is preferably 1 to 10, more preferably 1 to 8, further preferably 1 to 6, and further preferably 1 to 2. The carbon number of the alkenyl group or alkynyl group represented by R ² is preferably 2 to 10, more preferably 2 to 8, still more preferably 2 to 6, and further preferably 1 to 2. Is particularly preferred.

The number of carbon atoms of the arylalkyl group represented by R ³ is preferably 7 to 10, and more preferably 7 to 8.

r, s, and t are preferably integers satisfying r + s + t = 4, r ≧ 1, s ≧ 1, t ≧ 0, and r = 2, s = 2, and t = 0. Is more preferable. When r is 2 or 3, R ¹ may be the same or different. When s is 2 or 3, R ² may be the same or different. When t is 2, R 1 ³ may be the same or different.

  Specific examples of the ammonium ion in the formula include trioctyl, methyl, ammonium ion, tristearyl, ethyl, ammonium ion, trioctyl, ethyl, ammonium ion, tristearyl, methyl, ammonium ion, tridecyl, hexyl, ammonium ion, tritetrayl. Examples include decyl / propyl / ammonium ion, distearyl / dimethyl / ammonium ion, stearyl / dimethyl / phenylmethyl / ammonium ion, and the like.

X ⁻ is an anion, and for example, Cl ⁻ , Br ⁻ , OH ⁻ , NO ₃ ^{− and the} like are preferable.

  Intercalation of the quaternary ammonium salt causes an exchange between a cation between the clay mineral layers and a cation in the quaternary ammonium salt. Intercalation refers to the infiltration of molecules, ions, etc. into the interlayer region of clay minerals by contact with alkali metal ions or alkaline earth metal ions, etc. on the surface and layer of clay. This refers to causing an ion exchange reaction. The chargeability of the intercalation compound can be adjusted by the type of quaternary ammonium salt used for intercalation and the amount of quaternary ammonium salt.

  More specific methods include, for example, a method in which a quaternary ammonium salt is added to a clay mineral suspension in which clay mineral is dispersed in water and reacted. The solid (clay mineral) dispersion concentration in the suspension is not particularly limited as long as the clay mineral can be dispersed, but is preferably about 1 to 5% by weight. At this time, a clay mineral freeze-dried in advance may be used.

  The mixing amount of the quaternary ammonium salt is preferably adjusted so that the cation exchange capacity of the clay mineral and the quaternary ammonium ion are equivalent, but a smaller amount may be used, or an excess amount relative to the cation exchange capacity. It may be added. Specifically, the weight ratio of clay mineral to quaternary ammonium salt (clay mineral / quaternary ammonium salt) is preferably 90/10 to 60/40, more preferably 80/20 to 60/40, and even more preferably 75. / 25 to 60/40 is desirable.

  The reaction temperature between the clay mineral and the quaternary ammonium salt is preferably below the decomposition point of the quaternary ammonium salt.

  After the reaction, the solid-liquid is separated, and the resulting organic clay complex is washed with water or hot water to remove the by-product electrolyte, then dried, and pulverized as necessary to obtain a clay organic complex. It is done.

  Formation of clay organic complex is a method using chemical analysis, X-ray diffraction, NMR, infrared absorption spectrum, thermal balance, differential thermal analysis, rheology of high polarity solvent system, swelling power in high polarity organic solvent, color tone, etc. It can be confirmed by selecting according to the purpose and combining them appropriately.

  For example, in the method using X-ray diffraction, the formation of a clay organic complex can be easily confirmed by measuring the size of the 001 bottom reflection. The raw clay mineral is 10 mm in the dehydrated state and has a bottom surface spacing of 12 to 16 mm under normal temperature and humidity, but the clay organic composite in the present invention has a bottom surface spacing of about 18 mm.

  From the viewpoint of releasability, the content of the clay organic complex is 0.05 to 5% by weight in the toner, preferably 0.05 to 3% by weight, more preferably 0.1 to 2% by weight, and 0.3 to 1.5% by weight. Further preferred.

  Further, in the toner of the present invention, in addition to the clay organic complex as the saturation charge amount improver, a known charge control agent may be appropriately contained as long as the effects of the present invention are not impaired. Other charge control agents include a triphenylmethane dye containing a tertiary amine as a side chain, a polyamine resin, an imidazole derivative, a positive charge control agent such as a nigrosine dye, a metal-containing azo dye, a copper phthalocyanine dye, Examples include negatively chargeable charge control agents such as metal complexes of salicylic acid compounds, nitroimidazole derivatives, and boron complexes of benzylic acid.

  The content of the charge control agent varies depending on the type and the like, but is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  The toner of the present invention contains an alkylene bis fatty acid amide having high compatibility with polyester as a release agent.

  2-8 are preferable and, as for carbon number of the alkylene group of alkylenebis fatty acid amide, 2-6 are more preferable. Moreover, 6-30 are preferable and, as for carbon number of the fatty acid group in alkylene bis fatty acid amide, 8-24 are more preferable. Suitable alkylene bis fatty acid amides in the present invention include ethylene bis stearic acid amide, hexamethylene bis lauric acid amide, ethylene bis lauric acid amide, hexamethylene bis stearic acid amide, etc., from the viewpoint of high crystallinity. Ethylene bis stearamide is more preferable.

  The content of the alkylene bis fatty acid amide is preferably 0.1 to 5% by weight, more preferably 0.5 to 4% by weight, and still more preferably 1 to 3% by weight in the toner from the viewpoint of achieving both releasability and developability.

  The weight ratio of the clay organic complex to the alkylene bis fatty acid amide (clay organic complex / alkylene bis fatty acid amide) is preferably 1/30 to 2/1 from the viewpoint of achieving both releasability and developability, ~ 1/1 is more preferable, and 1/6 to 1/1 is more preferable.

  Furthermore, the toner of the present invention may appropriately contain other release agents as long as the effects of the present invention are not impaired. Other release agents include low molecular weight polypropylene, low molecular weight polyethylene, low molecular weight polypropylene polyethylene copolymer, aliphatic hydrocarbon waxes such as microcrystalline wax, paraffin wax, and Fischer-Tropsch wax and their oxides, carnauba. Examples include waxes, montan waxes, sazol waxes, and ester waxes such as those deoxidized waxes, fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, and the like. Therefore, the content of the other release agent is preferably 0.1 to 20 parts by weight, and more preferably 0.5 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 colorant, magnetic powder, fluidity improver, conductivity modifier, extender pigment, reinforcing filler such as fibrous substance, antioxidant, anti-aging agent, cleaning improver, etc. These additives may be contained as appropriate.

  As the colorant, 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, etc. These may be contained alone or in admixture of two or more. 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 can be produced by a known method such as a kneading and pulverizing method, an emulsion aggregation method, a spray drying method, or a polymerization method. As a general method for producing a pulverized toner by a kneading pulverization method, for example, toner materials such as a binder resin, a clay organic composite, and ethylene bisstearamide are uniformly mixed with a mixer such as a ball mill, and then sealed. Examples of the method include melt kneading with a kneader or a single-screw or twin-screw extruder, cooling, pulverization, and classification. Furthermore, a fluidity improver such as hydrophobic silica may be added to the coarsely pulverized product in the production process or the surface of the obtained toner, if necessary. The volume median particle size (D ₅₀ ) of the toner of the present invention is preferably 3 to 15 μm, more preferably 4 to 8 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 for electrophotography of the present invention can be used as a one-component developing toner as it is, or as a two-component developer mixed with a carrier, and can be used in either a one-component developing method or a two-component developing method.

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

[Maximum peak temperature and melting point of resin endotherm]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), the temperature is raised to 200 ° C, and the sample cooled to 0 ° C at a temperature drop rate of 10 ° C / min is measured at a temperature rise rate of 10 ° C / min. . Among the observed endothermic peaks, the peak temperature on the highest temperature side is defined as the highest endothermic peak temperature. When the difference between the maximum peak temperature and the softening point is within 20 ° C, the peak temperature is taken as the melting point.

[Glass transition point of resin]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), the temperature is raised to 200 ° C, and the sample cooled to 0 ° C at a temperature drop rate of 10 ° C / min is measured at a temperature rise rate of 10 ° C / min. . When the difference between the maximum endothermic peak temperature and the softening point is within 20 ° C, the peak extension line below the peak temperature observed at a temperature lower than the maximum endothermic peak temperature and the peak from the rising edge of the peak The temperature at the point of intersection with the tangent indicating the maximum inclination to the top of is read as the glass transition point. When the difference between the maximum endothermic peak temperature and the softening point exceeds 20 ° C, an extension of the baseline below the maximum endothermic peak temperature and a tangent line indicating the maximum slope from the peak of the peak to the peak apex The temperature at the intersection is read as the glass transition point.

[Resin crystallinity index]
The crystallinity index is calculated from the softening point measured in accordance with the above and the highest endothermic peak temperature using the following formula.
Crystallinity index = softening point / maximum endothermic peak temperature

[Acid value of the resin]
Measured according to the method of JIS K0070. However, only the measurement solvent was changed from the mixed solvent of ethanol and ether specified in JIS K0070 to the mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

(Volume-median particle size of toner (D ₅₀ ))
Measuring instrument: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 100μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter)
Electrolyte: Isoton II (Beckman Coulter)
Dispersion: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB: 13.6) is dissolved in the electrolytic solution to a concentration of 5% by weight to obtain a dispersion.
Dispersion conditions: 10 mg of a measurement sample is added to 5 mL of the above dispersion, and dispersed for 1 minute with an ultrasonic disperser, then 25 mL of electrolyte is added, and further dispersed for 1 minute with an ultrasonic disperser. Prepare a dispersion.
Measurement conditions: By adding the sample dispersion to 100 mL of the electrolyte solution, the particle size of 30,000 particles is adjusted to a concentration that can be measured in 20 seconds, and then 30,000 particles are measured. Determine the volume-median particle size (D ₅₀ ).

Resin production examples 1-2
Raw material monomers other than trimellitic anhydride shown in Table 1 and 40 g of dibutyltin oxide are placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, dehydrator tube, stirrer and thermocouple, and are heated at 230 ° C for 20 hours. And then reacted at 8.3 kPa for 1 hour. Further, trimellitic anhydride shown in Table 1 was added at 210 ° C. and reacted until reaching a desired softening point to obtain resins A and B (both amorphous polyester).

Resin production example 3
Raw material monomers other than trimellitic anhydride shown in Table 1 and 40 g of dibutyltin oxide are placed in a 10-liter four-necked flask equipped with a nitrogen introduction tube, dehydration tube, stirrer and thermocouple, and are heated at 200 ° C. for 10 hours. And reacted. Thereafter, the mixture was reacted at 8.3 kPa for 1 hour, and trimellitic anhydride shown in Table 1 was further added and reacted at normal pressure for 1 hour to obtain a resin a (crystalline polyester).

Production Examples 1 to 4 of Clay Organic Complex
A smectite clay mineral having the composition shown in Table 2 was dispersed in 1000 mL of tap water, 300 mL of a quaternary ammonium salt shown in Table 2 dissolved in pure water was added thereto, and the mixture was reacted at room temperature for 2 hours with stirring. Next, the product was subjected to solid-liquid separation and washing to remove by-product salts, and then dried and pulverized to obtain clay organic composites A to D.

Examples 1-6 and Comparative Examples 1-3
50 parts by weight of resin A, 30 parts by weight of resin B, 20 parts by weight of resin a, 0.5 parts by weight of paraffin wax “HNP-9” (manufactured by Nippon Seiki Co., Ltd.), charge control agent “LR-147” (manufactured by Nippon Carlit) 1.0 part by weight of the clay organic composite shown in Table 3, ethylenebisstearic acid amide, and a colorant were stirred and mixed in a 5 L Henschel mixer at 3600 r / min for 5 minutes. Thereafter, the kneaded part was melt kneaded using a co-rotating twin screw extruder having a total length of 1560 mm, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm. The rotation speed of the roll was 200 r / min, the set temperature in the roll was 100 ° C., the outlet temperature of the kneaded product was about 140 ° C., the feed rate of the mixture was 10 kg / hour, and the average residence time was about 18 seconds. The obtained kneaded product was rolled and cooled with a cooling roller, then pulverized with a jet mill, and classified to obtain a powder having a volume-median particle size (D ₅₀ ) of 5.5 μm.

  To 100 parts by weight of the obtained powder, 1.5 parts by weight of an external additive “Aerosil R-972” (manufactured by Nippon Aerosil Co., Ltd.) was added, and mixed with a Henschel mixer at 3600 r / min for 5 minutes to obtain a toner.

Test Example 1 [Releasability]
The toner shown in Table 3 was mounted on a copying machine “AR-505” (manufactured by Sharp Corporation), and images were unfixed at 2 cm × 12 cm and 0.6 mg / cm ² . The obtained unfixed image was fixed on paper at 500 mm / sec while the fixing device of the copying machine was offline and gradually increased from 90 ° C. to 240 ° C. by 10 ° C. The presence or absence of offset / winding was confirmed, and the releasability was evaluated according to the following evaluation criteria. The results are shown in Table 3. In addition, 250 g paper and 50 g paper were used for the paper, and the temperature width at which no offset occurred was confirmed on either paper.

[Evaluation criteria for releasability]
◎: Non-offset range 100 ° C or higher, no wrapping occurred in the evaluation range ○: Non-offset range 70 ° C or higher, less than 100 ° C, no wrapping occurred in the evaluation range △: Non-offset range 70 ° C or lower, no wrapping occurred in the evaluation range No occurrence x: Winding occurs in the evaluation range

Test Example 2 [Developability]
The developer “ML 7300” (Oki Data Co., Ltd.) was remodeled so that it can be rotated and rotated at 200 mm / sec for 30 minutes. Thereafter, the layer formation state on the surface of the developing roller was visually confirmed, and developability was evaluated according to the following evaluation criteria. The results are shown in Table 3.

[Development evaluation criteria]
○: No streak occurred ×: Streaks confirmed

  From the above results, it can be seen that the toners of Examples 1 to 6 show better results than the toners of Comparative Examples 1 to 3, although the releasability varies depending on the clay mineral used in the clay organic composite. Further, the toners of Comparative Examples 1 and 2 having no clay organic composite have poor releasability, while the toner of Comparative Example 3 having a clay organic composite content of 8.0% by weight is ethylene bisstearin. Due to poor dispersion of the acid amide, streaks occurred and developability was poor.

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

Claims (5)

  A binder resin containing polyester, a clay organic composite obtained by intercalating a quaternary ammonium salt with a clay mineral, and an electrophotographic toner comprising an alkylenebisfatty acid amide, the clay organic composite An electrophotographic toner having a body content of 0.05 to 5% by weight in the toner.   2. The toner for electrophotography according to claim 1, wherein the content of the alkylene bis fatty acid amide is 0.1 to 5% by weight.   The toner for electrophotography according to claim 1 or 2, wherein a weight ratio of the clay organic complex to the alkylene bis fatty acid amide (clay organic complex / alkylene bis fatty acid amide) is 1/30 to 2/1.   The electrophotographic toner according to claim 1, wherein the polyester contains a crystalline polyester. A quaternary ammonium salt has the formula (A):
[(R ¹ ) _r (R ² ) _s (R ³ ) _t N] ⁺ · X ⁻ (A)
(In the formula, R ¹ and R ² are not the same, R ¹ is an alkyl group, an alkenyl group or an alkynyl group having 4 to 24 carbon atoms, and R ² is an alkyl group having 1 to 10 carbon atoms or a carbon number. An alkenyl group or an alkynyl group having 2 to 10; R ³ is a phenyl group or an arylalkyl group having 7 to 10 carbon atoms; and r, s, and t are r + s + t = 4, r ≧ 1, s ≧ 1 represents an integer satisfying t ≧ 0, and X ⁻ represents an anion)
The toner for electrophotography according to claim 1, represented by: