JP4884201B2 - Non-magnetic one-component developing toner - Google Patents

Description

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

  In recent years, with the miniaturization, high speed, and high image quality of printers, high performance is required for toner. In particular, for speeding up the printer, it is required that the toner quickly reaches a predetermined charge amount. Further, in the non-magnetic one-component development method, since charging is performed without using a carrier, it is difficult to impart charge, and toner scattering due to insufficient charging is likely to occur. Therefore, a technique for improving toner chargeability is required.

As a technique for improving the chargeability of the toner, for example, Patent Document 1 discloses a toner in which an external additive that has been surface-treated with a fluorine-containing silane compound is added to a toner containing a fluorine-containing compound on the surface. ing. Further, Patent Document 2 discloses an external additive for silica surface-treated with a fluorine-containing silane coupling agent and hexamethyldisilazane.
JP 2004-212620 A JP 2004-144854 A

  However, the external additive surface-treated with only the fluorine-containing silane compound must be sufficiently charged with the toner newly transported to the developing roller in a system that instantaneously charges, such as a non-magnetic one-component development system. The toner scatters easily. Further, since the fluorine-containing silane compound is hydrophilic, the toner containing the compound has a problem that the environmental stability is particularly poor under high humidity and fogging is likely to occur.

  An object of the present invention is to provide a toner for non-magnetic one-component development in which toner scattering and fog are reduced.

  The present inventors have found that by using an external additive treated with a specific surface treatment agent and a specific polyester resin in combination, a toner for non-magnetic one-component development that reduces toner scattering and fogging can be obtained. The headline and the present invention were completed.

  That is, the present invention relates to a non-magnetic one-component developing toner containing a binder resin, a colorant, and an external additive containing inorganic fine particles treated with at least two types of surface treatment agents. The resin is of formula (I):

(In the formula, RO is an alkyleneoxy group, 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 the alkyleneoxy group, and the sum of x and y is 1) ~ 16)
A polyester obtained by condensation polymerization of an alcohol component containing an alkylene oxide adduct of bisphenol A and a carboxylic acid component containing terephthalic acid, wherein the surface treatment agent is at least a fluorine-containing silane coupling agent ( The present invention relates to a non-magnetic one-component developing toner which is a hydrophobizing agent (b) other than a) and a fluorine-containing silane coupling agent.

  The toner of the present invention has an excellent effect that toner scattering and fogging can be reduced.

  The present invention is a non-magnetic one-component developing toner containing a binder resin, a colorant, and an external additive containing inorganic fine particles treated with at least two types of surface treatment agents, wherein the binder resin comprises: It is a specific polyester and has a significant feature in that the surface treatment agent is at least a fluorine-containing silane coupling agent (a) and a hydrophobic treatment agent (b) other than the fluorine-containing silane coupling agent.

  Polyester is composed of a monomer having a benzene ring, so that the toner can be imparted with negative chargeability derived from the π-electron orbit of the benzene ring. Insufficient charge buildup is also insufficient. On the other hand, even when an external additive that has been subjected to fluorine treatment for imparting negative chargeability is used in the toner for non-magnetic one-component development, the charge rising property is low and the charge imparting is not in time, and toner scattering is likely to occur. . Further, since the fluorine-treated external additive has a low degree of hydrophobicity, fogging is prominent in a high humidity environment.

  However, in the present invention, in addition to the polyester having the above-described configuration and the fluorine-containing silane coupling agent (a), it was treated with at least two kinds of hydrophobic treatment agents (b) other than the fluorine-containing silane coupling agent. By combining with an external additive, a toner having excellent chargeability and reduced toner scattering and fog can be obtained.

  The detailed reason will be described below. When the external additive is treated in combination with a hydrophilic fluorine-containing silane coupling agent and a hydrophobizing agent other than the fluorine-containing silane coupling agent, the hydrophobicity of the external additive can be increased and the chargeability is reduced due to moisture absorption. At the same time, it is considered that the fluidity is improved, the charge imparting in the non-magnetic one-component system is improved, and the high chargeability of the fluorine-containing silane coupling agent can be exhibited. By combining the treated external additive with an alcohol component containing a specific compound having a benzene ring and a polyester obtained by condensation polymerization of a carboxylic acid component containing a specific compound having a benzene ring, Since the rising of the negative charge of the toner is good, it is considered that toner scattering and fogging are reduced.

  In the present invention, the external additive is an inorganic fine particle (A) treated with a surface treatment agent comprising at least two kinds of a hydrophobizing silane coupling agent (a) and a hydrophobizing agent (b) other than the fluorinated silane coupling agent. )including.

  Examples of the base material of the inorganic fine particles (A) include inorganic oxides selected from the group consisting of silica, titania, alumina, zinc oxide, magnesium oxide, cerium oxide, iron oxide, copper oxide, and tin oxide. Can be used alone or in combination of two or more. Among these, silica is preferable from the viewpoint of improvement in chargeability and fluidity.

Although what was manufactured by the well-known method can be used for a silica, what was manufactured by the dry process and the high temperature hydrolysis method from a dispersible viewpoint of a silica is preferable. In addition to anhydrous silica, it may contain aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, zinc silicate, etc., but preferably contains SiO ₂ at 80% by weight or more, Those containing 85% by weight or more are more preferable.

As the treating agent (a), a known fluorine-containing silane coupling agent can be used. For example, CF ₃ CH ₂ CH ₂ SiCl ₃ , CF ₃ C (═O) OCH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ CH ₂ CH ₂ Si (CH ₃ ) Cl ₂ , nC ₈ F ₁₇ CH ₂ CH ₂ Si (CH ₃ ) (OCH ₃ ) ₂ , CF ₃ C (= O) OSi (CH ₃ ) ₃ , nC ₄ F ₉ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₃ CH ₂ CH ₂ SiCl ₃ , C ₇ F ₁₅ CONHCH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃ , CF ₃ CH ₂ CH ₂ Si (CH ₃ ) (OCH ₃ ) ₂ , C ₈ F ₁₇ SO ₂ NHCH ₂ CH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃ , CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₇ H ₁₅ COOCH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₉ F ₁₉ SO ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ SO ₂ Si (CH ₃ ) ₃ etc. They can also be used in combination. Among these, CF ₃ CH ₂ CH ₂ SiCl ₃ is preferable from the viewpoint of imparting charging performance.

  Examples of the treating agent (b) include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), silicone oil, methyltriethoxysilane, and the like. These can be used alone or in combination of two or more. . Among these, silicone oil, HMDS and DMDS are preferable from the viewpoint of hydrophobicity and fluidity, and HMDS is more preferable from the viewpoint of fluidity.

  The amount of the base material treated with the treatment agent (a) is preferably 1 to 30 parts by weight, more preferably 3 to 20 parts by weight with respect to 100 parts by weight of the inorganic fine particles before the hydrophobization treatment from the viewpoint of imparting chargeability. .

  From the viewpoint of imparting hydrophobicity, the amount of the base material treated with the treatment agent (b) is preferably 1 to 30 parts by weight, more preferably 3 to 20 parts by weight with respect to 100 parts by weight of the inorganic fine particles before the hydrophobic treatment. .

  The ratio (a / b) of the weight of the treatment agent (a) to the treatment agent (b) is preferably 0.1 to 10, more preferably 0.2 to 0.5, and still more preferably 0.4 to 2.5.

  Moreover, in this invention, in the range which does not impair the effect of this invention, processing agents other than processing agent (a) and (b) can be used. The total content of the treatment agents (a) and (b) in the total amount of the surface treatment agent is preferably 90% by weight or more, more preferably 95% by weight or more, and further preferably 98% by weight or more.

  The surface treatment method for the inorganic fine particle (A) substrate is not particularly limited as long as the treatment agents (a) and (b) are adsorbed on the substrate surface, but preferably the vaporized treatment agent is used as the substrate. For example, silica is placed in a pressure vessel, and the treatment agent is vaporized by introducing a treatment agent at a treatment temperature of 250 ° C., and the pressure vessel is stirred for 30 minutes while stirring. Is preferably performed. The treatment with two or more kinds of treatment agents may be performed simultaneously or separately, but from the viewpoint of imparting hydrophobicity, it is preferable to perform the treatment with the treatment agent (b) later.

  The average particle diameter of the inorganic fine particles (A) is preferably 8 to 100 nm, more preferably 12 to 40 nm, from the viewpoint of imparting chargeability. In the present specification, the average particle size of the inorganic fine particles is measured by the method described in Examples described later.

  The degree of hydrophobicity of the inorganic fine particles (A) is preferably 20 to 85%, more preferably 30 to 80%, and further preferably 50 to 80% from the viewpoint of reducing toner scattering and fogging under high temperature and high humidity. In the present specification, the degree of hydrophobicity of the inorganic fine particles is measured by the method described in Examples described later.

  The external addition amount of the inorganic fine particles (A) is preferably 0.1 to 4.0 parts by weight, more preferably 0.3 to 2.0 parts by weight, and more preferably 0.5 to 2.0 parts by weight with respect to 100 parts by weight of the toner base particles from the viewpoint of reducing toner scattering and fogging. 1.0 part by weight is more preferable.

  Moreover, as an external additive, you may contain other external additives other than the said inorganic fine particle (A) in the range which does not impair the effect of this invention. Examples of other external additives include inorganic fine particles (B) surface-treated with one of the above-described treatment agents. As the base material of the inorganic fine particles (B), the same base material as that of the inorganic fine particles (A) described above can be used, and the inorganic fine particles (B) can be treated with silicone oil from the viewpoint of imparting further chargeability. The performed silica is preferred. The inorganic fine particles (B) can be produced in the same manner as the inorganic fine particles (A). The average particle diameter of the inorganic fine particles (B) is the same as or larger than that of the inorganic fine particles (A), specifically 1 to 6 times, more preferably 2 to 5 times.

  The content of the inorganic fine particles (A) in the external additive is preferably 20 to 100% by weight, more preferably 25 to 100% by weight, and further preferably 30 to 60% by weight.

  The binder resin in the present invention has the formula (I):

(In the formula, RO is an alkyleneoxy group, 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 the alkyleneoxy group, and the sum of x and y is 1) ~ 16, preferably 1-5)
A polyester obtained by polycondensation of an alcohol component containing an alkylene oxide adduct of bisphenol A and a carboxylic acid component containing terephthalic acid.

  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.

  Furthermore, the alcohol component may contain other components other than the alkylene oxide adduct of bisphenol A represented by the formula (I) as long as the effects of the present invention are not impaired. Other components include ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, neopentyl glycol, polyethylene glycol, polypropylene glycol, bisphenol A, hydrogenated bisphenol A, sorbitol, pentaerythritol, glycerol, trimethylol The content of the alkylene oxide adduct of bisphenol A represented by the formula (I) in the alcohol component is preferably 50 mol% or more, more preferably 60 mol% or more, and 80 mol% or more. Is more preferable.

  The carboxylic acid component contains terephthalic acid from the viewpoint of reducing toner scattering and fogging. The content of terephthalic acid in the carboxylic acid component is preferably 20 to 100 mol%, more preferably 40 to 95 mol%, still more preferably 50 to 90 mol%, from the viewpoint of charging stability. The carboxylic acid component may contain other components other than terephthalic acid as long as the effects of the present invention are not impaired. Examples of other components include adipic acid, fumaric acid, maleic acid, and succinic acid. An acid (e.g., n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, etc.) or an alkenyl group having 2 to 20 carbon atoms. Aromatics such as aliphatic carboxylic acids (substituted succinic acid), phthalic acid, isophthalic acid, 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, etc. Group carboxylic acids, and anhydrides and lower alkyl (C1-3) esters of these acids.

  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 50 mol%, more preferably 10 to 30 mol%, based on 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 polycondensation of the alcohol component and the carboxylic acid component can be performed, for example, in an inert gas atmosphere at a temperature of 180 to 250 ° C. From the viewpoint that the effects of the present invention are more remarkably exhibited, the ester It is preferable to carry out in the presence of the catalyst. Examples of esterification catalysts include dibutyltin oxide, titanium compounds, tin (II) compounds having no Sn—C bond, and the like. These may be used alone or in combination. Among these, a tin (II) compound having no Sn—C bond is preferable from the viewpoint of more remarkable effects of the present invention.

  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 a Sn-O bond include tin (II) oxalate, tin (II) diacetate, tin (II) dioctylate, tin (II) dilaurate, tin (II) distearate, diolein Carboxylic acid tin (II) 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 oxide (II); tin (II) sulfate and the like having a Sn—X (X represents a halogen atom) bond include chloride. Examples thereof include tin (II) halides such as tin (II) and tin (II) bromide. Among these, (R ¹ COO) ₂ Sn (where R ¹ is a fatty acid tin represented by an alkyl or alkenyl group 5 to 19 carbon ^{atoms) (II), (R 2} O) 2 Sn ( wherein R ² is an alkyl group having 6 to 20 carbon atoms Dialkoxy tin (II) and tin oxide represented by SnO (II) is preferably represented by the alkenyl a group), (R ¹ COO) fatty tin represented by ₂ Sn (II) and tin oxide (II ) Is more preferable, and tin (II) dioctylate, tin (II) distearate, and tin (II) oxide are more preferable.

  The softening point of the polyester is preferably 70 to 140 ° C, more preferably 80 to 140 ° C, and still more preferably 85 to 135 ° C, from the viewpoint of fixability. In the present specification, the softening point is measured by the method described in Examples described later.

  The glass transition point of the polyester is preferably 50 to 85 ° C, more preferably 55 to 80 ° C. The acid value is preferably 1 to 40 mgKOH / g, more preferably 2 to 38 mgKOH / g, from the viewpoint of dispersibility. In this specification, a glass transition point and an acid value are measured by the method as described in the below-mentioned Example.

  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.

  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., and these can be used alone or in admixture of two or more. The toner of the present invention is a black toner or a color toner. Either may be sufficient. 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.

  In the present invention, in addition to the binder resin and the colorant, a charge control agent, a release agent, a conductivity adjusting agent, an extender pigment, a reinforcing filler such as a fibrous substance, an antioxidant, an anti-aging agent, a magnetic substance, etc. These additives may be blended as a toner raw material.

  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. The content of the charge control agent is preferably 0.1 to 5 parts by weight and more preferably 0.5 to 2 parts by weight with respect to 100 parts by weight of the binder resin.

  As the release agent, low molecular weight polypropylene, low molecular weight polyethylene, low molecular weight polypropylene polyethylene copolymer, aliphatic hydrocarbon wax such as microcrystalline wax, paraffin wax, Fischer-Tropsch wax and oxides thereof, carnauba wax, Examples include ester waxes such as montan wax, sasol wax and their deoxidized wax, fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts and the like. Among these, aliphatic hydrocarbon waxes and ester waxes are preferable from the viewpoint of releasability and stability, and these may be contained alone or in admixture of two or more. The content of the 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 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. However, from the viewpoint of productivity, a pulverized toner obtained by a melt-kneading method may be used. preferable. In the case of pulverized toner by the melt-kneading method, toner materials such as a binder resin and a colorant are uniformly mixed with a mixer such as a Henschel mixer or a ball mill, and then a sealed kneader, a single or twin screw extruder, an open roll Melt-knead with a mold kneader, etc., cool, coarsely pulverize with a hammer mill, further pulverize with a fine pulverizer or mechanical pulverizer using a jet stream, and a classifier or Coanda effect using a swirling airflow The toner base particles are obtained by classification to a predetermined particle size using a classifier using

  Further, an external additive is externally added to the toner base particles obtained above. The external additive is preferably added to the toner base particles by a dry mixing method in which the toner base particles and the external additive are mixed using a high-speed stirrer such as a Henschel mixer or a super mixer, a V-type blender, or the like. Further, when the inorganic fine particles (A) and other external additives (hereinafter sometimes referred to as “other external additives”) are used in combination, the addition of the inorganic fine particles (A) and other external additives May be simultaneous or separate, but simultaneous addition is preferred from the viewpoint of productivity.

The volume median particle size (D ₅₀ ) of the toner of the present invention is preferably from 3 to 9 μm, more preferably from 4 to 8 μm, from the viewpoint of image quality and ease of handling as a powder. 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 is used in a non-magnetic one-component development system, and the effect of the present invention becomes remarkable when used in a non-magnetic one-component development system using a negatively charged organic photoreceptor.

[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, a 1.96 MPa load is applied by a plunger, and the sample is 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.

[Glass transition point of resin]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), the temperature was raised to 200 ° C, and the sample cooled to 0 ° C at a cooling rate of 10 ° C / min was measured at a heating rate of 10 ° C / min. The temperature at the intersection of the extended line of the baseline below the maximum peak temperature of endotherm and the tangent showing the maximum slope from the peak rising portion to the peak apex.

[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 (D ₅₀ ) of Toner Base Particles]
Measuring instrument: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 50μm
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 electrolyte so as to have 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 electrolytic 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 ).

[Average particle size of inorganic fine particles]
An average particle diameter is a number average particle diameter, and it calculates | requires from a following formula.
Number average particle diameter (nm) = 6 / (ρ × specific surface area (m ² / g)) × 1000
In the formula, ρ is the specific gravity of the inorganic fine particles, the specific gravity of silica is 2.2, and titania is 4.2. The specific surface area is a BET specific surface area determined by a nitrogen adsorption method. In the case of inorganic fine particles that have been subjected to a hydrophobic treatment, the specific surface area of the original material prior to the hydrophobic treatment is used.
Note that the above equation assumes a sphere with a particle size R,
BET specific surface area = S x (1 / m)
m (weight of particle) = 4/3 x π x (R / 2) ³ x specific gravity
S (surface area) = 4π (R / 2) ²
Is an expression obtained from

[Hydrophobicity of inorganic fine particles]
The degree of hydrophobicity is determined by a methanol titration method.
That is, 0.2 g of inorganic fine particles for measuring the degree of hydrophobicity are added to a glass container having an inner diameter of 7 cm and a capacity of 2 L or more containing 100 mL of ion-exchanged water, and stirred with a magnetic stirrer. The tip of a burette containing methanol is put into the liquid, 20 mL of methanol is added dropwise with stirring, the stirring is stopped after 30 seconds, and the state after 1 minute of stirring is observed. A series of operations is repeated until the inorganic oxide does not float on the water surface as a series of operations from dropping methanol to observing the state. When the total amount of methanol added when the inorganic oxide does not float on the water surface 1 minute after the stirring is stopped is Y (mL), the value obtained by the following formula is calculated as the degree of hydrophobicity. In addition, the water temperature in a beaker (glass container) is adjusted to 20 ° C. ± 1 ° C. and the measurement is performed.
Hydrophobicity (%) = [Y / (100 + Y)] × 100

Resin production example 1
568 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 792 g of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 640 g of terephthalic acid, and octylic acid 10 g of tin was reacted by stirring at 210 ° C. in a nitrogen atmosphere. The degree of polymerization was traced based on the softening point measured according to ASTM E28-51T, and the reaction was terminated when the softening point reached 110 ° C. to obtain Resin A. Resin A had a glass transition point of 64 ° C. and an acid value of 5 mgKOH / g.

Resin production example 2
1495 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 505 g of fumaric acid, and 10 g of tin octylate were stirred and reacted at 210 ° C. in a nitrogen atmosphere. The degree of polymerization was traced based on the softening point measured according to ASTM E28-51T. When the softening point reached 100 ° C., the reaction was terminated to obtain Resin B. Resin B had a glass transition point of 60 ° C. and an acid value of 16 mgKOH / g.

Resin production example 3
Ethylene glycol 337 g, neopentyl glycol 1093 g, terephthalic acid 1830 g, trimellitic acid 615 g, and tin octylate 10 g were reacted by stirring at 235 ° C. in a nitrogen atmosphere. The degree of polymerization was traced based on the softening point measured according to ASTM E28-51T. When the softening point reached 135 ° C., the reaction was terminated to obtain Resin C. Resin C had a glass transition point of 56 ° C. and an acid value of 10 mgKOH / g.

Resin production example 4
360 g of styrene, 115 g of butyl methacrylate, 9 g of divinylbenzene, 4 g of benzoyl peroxide, and 500 g of xylene were placed in a four-necked round bottom flask. After the inside of the reactor was replaced with an inert atmosphere, the contents were gradually heated by a mantle heater and raised to 75 ° C. The reaction was carried out while maintaining the temperature at 65 ° C. to 80 ° C., and after 10 to 12 hours, the temperature was raised to 130 ° C. to complete the polymerization to complete the polymerization. When the contents were sufficiently stirred and the vacuum pump was operated to reduce the pressure to 20 mmHg, xylene or possibly unreacted monomer began to distill at a liquid temperature of 75 ° C. and a distillation temperature of 38 ° C. Finally, at a liquid temperature of 180 ° C., the pressure was reduced to 0.5 mmHg to completely remove the solvent, and Resin D was obtained. Resin D had a softening point of 120 ° C. and a glass transition point of 55 ° C.

Examples 1-4 and Comparative Examples 1-6 (Example 4 is a reference example)
100 parts by weight of the binder resin shown in Table 2, 6.0 parts by weight of the colorant “Super Magenta R” (Dainippon Ink), 1.0 part by weight of the charge control agent “LR-147” (made by Nippon Carlit) and a release agent 6.0 parts by weight of “Carnauba Wax C1” (manufactured by Kato Yoko Co., Ltd., melting point: 83 ° C.) was stirred and mixed with a Henschel mixer and then melt-kneaded under the following conditions.

[Example of kneading conditions: open roll]
An open roll kneader “NIDEX” (manufactured by Mitsui Mining Co., Ltd., roll outer diameter: 140 cm, effective roll length: 80 cm) was used. The operating conditions of the continuous two-roll kneader are as follows: high rotation side roll (front roll) peripheral speed 9m / min, low rotation side roll (back roll) peripheral speed 6m / min, roll at the end of the kneaded product supply port The gap was 0.1 mm. The heating medium temperature and cooling medium temperature in the roll were 160 ° C. on the raw material input side of the high rotation roll and 100 ° C. on the kneaded material discharge side, 30 ° C. on the raw material input side of the low rotation roll and 30 ° C. on the kneaded material discharge side. . The feed rate of the raw material mixture was 4 kg / hour, and the average residence time was about 10 minutes.

The melt-kneaded material obtained above is rolled and cooled with a cooling roller, and then pulverized and classified with a jet mill pulverizer and an airflow classifier (IDS: manufactured by Nippon Pneumatic Co., Ltd.) to obtain a volume-median particle size (D ₅₀ ) 8 m mother toner particles were obtained.

  Examples 1 to 1 were prepared by adding the external additives shown in Table 2 to 100 parts by weight (1 kg) of the obtained toner base particles and mixing them with a 10 L Henschel mixer for 3000 rotations for 180 seconds. 4 and Comparative Examples 1 to 6 were obtained. Details of the external additives shown in Table 2 are shown in Table 1.

Test Example 1 [Fog]
The toner of each example and each comparative example is mounted on a non-magnetic one-component developing device “MicroLine 5400” (manufactured by Oki Data Corporation) equipped with an organic photoreceptor (OPC), and the environment is kept at 25 ° C./50% RH for 12 hours. Blank paper (0%) was printed after leaving it to stand. After that, the toner remaining on the photosensitive drum is copied with a mending tape, and the image density difference ΔE from the reference is measured with a color difference meter “X-Rite” (manufactured by X-Rite). (Fog) was evaluated. If ΔE is less than 1.5, it indicates that it is good. The results are shown in Table 2.

  Further, after the toner was mounted in the same apparatus as described above, it was allowed to stand in an environment of 25 ° C./80% RH for 12 hours, and then fog (high humidity fog) was evaluated in the same manner as described above. The results are shown in Table 2.

Test Example 2 [Toner scattering]
The toner of each example and each comparative example was mounted on the same apparatus as in Test Example 1, and after standing for 12 hours in a 25 ° C./50% RH environment, 3000 images with a printing rate of 5% were printed. Thereafter, the degree of contamination by toner around the developing tank was visually observed, and toner scattering (NN toner scattering) was evaluated according to the following evaluation criteria. The results are shown in Table 2.

  Further, after mounting the toner in the same apparatus as described above, the toner was allowed to stand for 12 hours in a 25 ° C./80% RH environment, and then the toner scattering (high-humidity toner scattering) was evaluated in the same manner as described above. The results are shown in Table 2.

[Evaluation criteria for toner scattering]
A: There is no dirt due to the scattered toner. B: Slight dirt is observed due to the scattered toner. Δ: Stain is clearly observed due to the scattered toner. Dirt due to used toner is seen

  From the above results, it can be seen that the toner of the example is superior to the toner of the comparative example with reduced fog and toner scattering. Further, from Example 1, in addition to the external additive in which the surface treatment with fluorine silane and HDMS was performed on the same silica, the addition of the external additive in which the surface treatment with silicone oil was performed on another silica, the toner base It can be seen that since the fluorinated silica adhering to the particle surface can be protected and the environment of the toner base particle surface can be made more hydrophobic, the occurrence of fogging, particularly under high humidity, can be reduced. On the other hand, in Comparative Example 2, silica treated with fluorine silane and silica treated with HDMS are used in combination, and fogging and toner scattering are particularly noticeable at high humidity. This is because the silica treated with fluorine silane is hydrophilic and can no longer retain chargeability under high humidity. Surface treatment with a fluorine-containing silane coupling agent and other hydrophobizing agents is not possible. This suggests that it must be carried out on the same inorganic fine particles. Comparative Examples 4 to 6 use an external additive obtained by subjecting fluorine silane and surface treatment with HDMS to the same inorganic fine particles, but the binder resin is a condensed resin of bisphenol A alkylene oxide compound and terephthalic acid. Since it is not obtained by polymerization, the charging property derived from the benzene ring is weak, and in the non-magnetic one-component development method, it is considered that fog and toner scattering occurred due to insufficient charging during development.

  The non-magnetic one-component developing toner of the present invention is suitably used for developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, and the like.

Claims (2)

A nonmagnetic one-component developing toner containing a binder resin, a colorant, and an external additive containing silica fine particles treated with at least two kinds of surface treatment agents, wherein the binder resin is represented by formula (I) :

(In the formula, RO is an alkyleneoxy group, 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 the alkyleneoxy group, and the sum of x and y is 1) ~ 16)
A polyester obtained by condensation polymerization of an alcohol component containing an alkylene oxide adduct of bisphenol A and a carboxylic acid component containing terephthalic acid, wherein the surface treatment agent is at least a fluorine-containing silane coupling agent ( A toner for non-magnetic one-component development, which is a hydrophobizing agent (b) other than a) and a fluorine-containing silane coupling agent. The toner for non-magnetic one-component development according to claim 1, wherein the degree of hydrophobicity of the silica fine particles treated with at least two types of surface treating agents is 20 to 85%.