JP4733563B2 - Orange toner for electrophotography and image forming apparatus using the same - Google Patents

Description

  The present invention relates to a toner and an image forming apparatus for visualizing an electrostatic latent image formed by electrophotography, electrostatic printing, electrostatic recording, or the like.

  In recent years, color formation has progressed in image forming apparatuses. In general-purpose color printers, non-magnetic one-component color toner that does not use a magnetic carrier is frequently used, and in high-speed printers, magnetic brush development using a two-component developer. The method is commonly used.

  Especially in printing in the high-speed area, only monochrome printing has been used in the past, but the demand for on-demand printing has increased, and in addition to process colors such as yellow, magenta, and cyan, the demand for spot colors has increased. ing.

  To date, an orange electrostatic image developing toner described in Patent Document 1 is known as an orange toner. An object of the invention described in Patent Document 1 is to provide a toner that has an orange color with excellent color developability and does not cause false detection when used in an image forming apparatus.

  Further, Patent Document 2 discloses an orange toner that defines an orange colorant and an orange toner that uses a mixture of a yellow pigment and a red pigment. An object of the invention described in Patent Document 2 is to provide an orange toner that improves the dispersibility of a colorant by combining a polyester resin and an ester-based wax, thereby obtaining an orange image with high saturation.

Japanese Patent Application Laid-Open No. 61-118759 Japanese Patent Laid-Open No. 2002-156776

  Among the pigments that have been published so far, the perinone pigment represented by CIPigment Orange 43 is excellent in color development and light resistance, but the price of the pigment itself is high. The target is difficult. CIPigment Orange 43 pigment is typically Orange GR manufactured by Clariant. In addition to the high raw materials used in this structure, cis-type and trans-type are synthesized during synthesis, and the ratio is cis-type. The yield is 20% or less, and the transformer type is 80% or more. The perinone pigment represented by C.I.C.I.Pigment Orange 43 has a cis-type structure, and the trans-type is currently discarded because there is no demand. Therefore, there is a problem that the price of the pigment itself is very high and the versatility is poor.

  On the other hand, an orange toner prepared by mixing a yellow pigment and a red pigment has a problem that a difference in hue is large, a color blur occurs, and a vivid color cannot be obtained.

  As described above, the problem to be solved by the present invention is to provide an orange toner and an image forming apparatus that are capable of vivid color development, have excellent light resistance, and are versatile.

The first means of the present invention for solving the problems of the present invention is that in the orange toner for electrophotography using at least a fixing resin and a colorant , the colorant is C.I. I. Pigment Orange 64 and C.I. I. It is characterized by containing a pigment represented by PigmentRed in a range of 1: 0.05 to 1: 0.17.

A second means of the present invention for solving the problems of the present invention is that in the orange toner for electrophotography using at least a fixing resin and a colorant , the colorant is C.I. I. Pigment Orange 73 and C.I. I. Pigment Yellow is contained in the range of 1: 0.0375 to 1: 0.24.

A third means of the present invention for solving the problems of the present invention is characterized by containing 1% to 25% of the colorant.

A fourth means of the present invention for solving the problems of the present invention is characterized in that it contains at least a fixing resin, a colorant, a release agent and an external additive, and the average particle diameter of the toner is in the range of 2 to 12 μm. And

A fifth means of the present invention for solving the problems of the present invention is characterized by containing 0.1 to 8 parts by weight of the release agent with respect to 100 parts by weight of the fixing resin.

A sixth means of the present invention for solving the problems of the present invention is that when a charge control agent is added and the charge control agent is added internally, 0.1 to 10 wt% with respect to the fixing resin. It is characterized by being added.

A seventh means of the present invention for solving the problems of the present invention is formed on an electrostatic charge holding member in an image forming apparatus using the electrophotographic orange toner according to any one of claims 1 to 6. The latent electrostatic image is visualized, the visualized toner image is transferred onto a recording medium, the toner image remaining on the electrostatic charge holding member is cleaned, and the transferred toner image is fixed on the recording medium. It comprises an electrostatic image recording step for obtaining a recorded image. An eighth means of the present invention for solving the problems of the present invention is the image forming apparatus using the electrophotographic orange toner according to any one of claims 1 to 6, wherein the electrophotographic orange toner and A two-component developer composed of a magnetic carrier is used, and at least a plurality of developing magnetic rolls are used. The developing magnetic roll rotates in the direction opposite to the developing magnetic roll rotating in the forward direction and the forward direction of the electrostatic charge holding member. The electrostatic latent image is visualized by a center-feed developing device having a rotating developing magnetic roll, the visualized toner image is transferred onto a recording medium, and the toner image remaining on the electrostatic charge holding member is cleaned. And an electrostatic recording step of fixing a toner image transferred onto a recording medium to obtain a recorded image.

  According to the present invention, it is possible to provide a versatile electrophotographic toner and an image forming apparatus that exhibit high light resistance and provide a bright orange image, and further consider the environment and safety.

  Hereinafter, the present invention will be described in detail.

  The orange toner of the present invention is an electrophotographic toner containing at least a fixing resin and a colorant, and CIPigment Orange 11, 20, 20: 1, 23, 35, 64, 67, 69, 73, 74, Contains a colorant selected from the group consisting of 75, 77, 78, 81, 99, 114. These orange pigments are excellent in color development, light resistance and dispersibility. These colorants are appropriately selected from the dispersibility, color developability, color tone, and the like, and C.I. Pigment Orange 64 and C.I. Pigment Orange 73 are particularly preferable.

These orange pigments can be used alone, but a red pigment or a yellow pigment can be added to adjust the color tone. When a red pigment or a yellow pigment is added to the orange pigment, the color tone is close, so that the color is not easily blurred, and a bright orange color can be provided. In particular, a yellowish C.I. I. When using Pigment Orange 64, it is more possible to add a red pigment in the range of 1: 0 to 1: 0.2, preferably in the range of 1: 0.05 to 1: 0.17 with respect to the orange pigment. It becomes a color close to orange. In addition, C. I. When using Pigment Orange 73 , it is more possible to add a yellow pigment in the range of 1: 0 to 1: 0.3, preferably 1: 0.0375 to 1: 0.24 with respect to the orange pigment. It becomes a color close to orange. On the other hand, in the conventional method of producing an orange color by mixing a red pigment and a yellow pigment, a hue difference is large and a color blur occurs, and it is difficult to provide a bright orange color.

  As red pigments that can be added to the above-mentioned orange pigments, CIPigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 17, 18, 21, 22 , 23, 31, 32, 37, 38, 41, 42, 48: 1, 48: 2, 48: 3, 48: 4, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2 53, 53: 1, 53: 2, 54, 57, 57: 1, 58: 4, 60, 60: 1, 63: 1, 63: 2, 64: 1, 65, 66, 67, 68, 81 , 81: 1, 81: 2, 81: 3, 81: 4, 83, 88, 90, 90: 1, 101, 102, 104, 105, 106, 107, 108, 108: 1, 112, 113, 114 115, 122, 123, 133, 144, 146, 147, 149, 150, 151, 166, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 181, 184 , 185,187,188,189,190,191,193,194,200,202,206,207,208,209,210,214,216,220,221,224,230,231,232,233,235 , 236, 242, 243, 243: 1, 245, 246, 247, 251, 253, 254, 255, 256, 257, 258, 260, 264, 266, 267, 268, 269, 270, 272, 273, 274 275 etc. It is below.

  As yellow pigments that can be added to the above-mentioned orange pigments, CIPigment Yellow 1, 2, 3, 4, 5, 6, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 24, 31 , 32, 34, 35, 35: 1, 36, 36: 1, 37, 37: 1, 38, 40, 41, 42, 43, 48, 53, 55, 61, 62, 62: 1, 63, 65 73, 74, 75, 81, 83, 87, 93, 94, 95, 97, 98, 100, 101, 104, 105, 108, 109, 110, 111, 113, 115, 116, 117, 118, 119 , 120, 123, 126, 127, 128, 129, 133, 138, 139, 147, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164 , 166,167,168,169,170,171,172,173,174,175,176,180,181,182,183,184,185,188,189,191,193,194,198,199,202 , 203 and the like.

  In recent years, safety requirements for chemical substances have been increased by the laws of each country. In addition to the laws and regulations of each country, when these pigments are used as toners for printers, when the toner is fixed on paper or the like, it receives high-temperature heat to melt and solidify the resin in the toner. Pigments that do not contain harmful substances in the generated volatile organic compounds (VOC) are preferred, and are selected and used.

  L * is 60 to 80 and a * is 30 when expressed in the L * a * b * color system when the hue of an image output using a toner using a pigment selected from these conditions is measured. An orange toner having a value of ˜70 and b * in the range of 30 to 70 can be obtained. Preferably, L * is 65 or more, and a * and b * are 45 or more.

Here, the L * a * b * color system is a mixed color system in which L * value represents lightness, a * value represents the red-green axis, and b * represents the yellow-blue axis. The saturation C * = (a * ² + b * ² ) ^1/2 can be expressed. (JIS standard Z8729)
In general, when color reproduction is attempted using electrophotographic toner, the saturation C * increases as the amount of color material such as pigment contained in the toner increases, but the lightness L * decreases and the image becomes darker. On the contrary, if the amount of the color material is small, the lightness L * increases but the saturation C * tends to decrease. When compared with orange color tones, if the same a * b *, the larger the L *, the brighter the image, and if the same L *, the image with the high saturation C * has a vivid color.

The amount of pigment added to the toner is determined in consideration of the amount of toner placed on the paper or the like, but if the amount of toner is too large, offset and fog are likely to occur. A pigment must be added, resulting in deterioration of fixability. Generally, the pigment addition amount is adjusted so that a target color tone is obtained with a toner adhesion amount of 0.3 to 1.0 mg / cm ² .

  The orange toner of the present invention contains at least a fixing resin and a colorant. Examples of the fixing resin used in the toner of the present invention include the following resins.

  Styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and substituted homopolymers thereof; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene -Acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether Styrene copolymers such as copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers, polyvinyl chloride, phenol Resin, natural modified Fe Resin, natural resin-modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, chroman-indene Examples thereof include resins and petroleum resins, and polyester resins are preferable.

  Further, a low hygroscopic resin obtained by graft copolymerizing styrene-acryl with the above-described polyester resin can also be used. The styrene polymer or styrene copolymer may be cross-linked or a mixed resin. In order to fix at low temperature and prevent high temperature offset, for example, in the case of styrene to (meth) acrylic resin, it is composed of a high molecular weight polymer and a low molecular weight polymer, the former being a toner offset resistance and the latter being a fixing strength. It is effective for securing. It is said that the balance between the two compositions is important for achieving both low-temperature fixability and offset resistance, and also affects storage stability. The molecular weight distribution of the styrene to (meth) acrylic resin can be measured by gel permeation chromatography (GPC) for components soluble in tetrahydrofuran. By using a resin having a high molecular weight polymer component having a molecular weight exceeding 500,000 and a low molecular weight component having a molecular weight of 20,000 or less in GPC measurement in a range of 20:80 to 80:20, low temperature fixability and resistance An offset property can be achieved.

  As the polyester resin, for example, it can be obtained by dehydration condensation of dicarboxylic acid and diol, and as dicarboxylic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, maleic acid, maleic anhydride, adipic acid, fumaric acid, Dicarboxylic acids such as itaconic acid, citraconic acid, succinic acid, malonic acid, glutaric acid, or derivatives or ester compounds thereof can be used.

  Examples of the diol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, pentanediol, hexanediol, bisphenol A, polyoxyethylene- (2.0) -2,2-bis (4- Hydroxyphenyl) propane and derivatives thereof, polyoxypropylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.2) -polyoxyethylene- (2,0) 2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (6) -2,2-bis- (4-hydroxyphenyl) propane, polyoxypropylene- (2.2) -2,2-bis -(4hydroxyphenyl) propane, polyoxypropi -(2.4) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (3.3) -2, -bis (4-hydroxyphenyl) propane and derivatives thereof, polyethylene glycol, Polypropylene glycol, ethylene oxide-propylene oxide random copolymer diol, ethylene oxide-propylene oxide block copolymer diol, ethylene oxide-tetrahydrofuran copolymer diol, polycaprolactone diol, and the like can be used.

  Furthermore, the polyester is a tricarboxylic acid or more polycarboxylic acid such as trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, or a derivative thereof or an esterified product thereof, together with the dicarboxylic acid and diol. Sorbitol, 1,2,3,6-hexanetetraol, 1,4-sorbitan, pentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2 A trifunctional or higher polyhydric alcohol such as methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trimethylolbenzene can be obtained by dehydration condensation by a conventional method. it can.

  Further, in order to improve the compatibility between the fixing resin and the wax, the fixing resin may be prepared by a co-polymerization method in which the wax coexists in all or part of the synthesis when the fixing resin is synthesized.

  In the method of preparing a fixing resin by coexistence polymerization in the presence of wax, the vinyl copolymer includes a styrene monomer and / or a (meth) acrylate monomer as a constituent unit thereof. Other vinyl monomers can be included.

  By performing the coexistence polymerization in which the wax coexists in the present invention in the whole or a part of the synthesis, a vinyl copolymer in which the wax is uniformly dispersed can be obtained as at least a component thereof. The vinyl copolymer is mainly a monomer having two or more polymerizable double bonds, such as divinylbenzene, divinylnaphthalene, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, divinylaniline, divinyl It may be partially crosslinked with a crosslinking agent such as vinyl ether, divinyl sulfide, and divinyl sulfone.

  Specific examples of the styrene monomer as the structural unit of the vinyl polymer include orthomethyl styrene, metamethyl styrene, alphamethyl styrene, 2,4-dimethyl styrene and the like in addition to styrene.

  Specific examples of the acrylate ester or methacrylate ester monomer as the structural unit of the vinyl polymer include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, and acrylic acid n. -Octyl, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, methacryl In addition to acrylic acid or methacrylic acid alkyl esters such as stearyl acid, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, Examples include diethylaminoethyl tacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, bisglycidyl methacrylate, polyethylene glycol dimethacrylate, methacryloxyethyl phosphate, and the like. Ethyl acrylate, propyl acrylate, butyl acrylate, methacrylic acid Methyl, ethyl methacrylate, propyl methacrylate, butyl methacrylate and the like are particularly preferably used.

  Other vinyl monomers as a constituent unit of the vinyl polymer include acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, and α- or β-alkyl derivatives thereof, fumaric acid, maleic acid. Examples include unsaturated dicarboxylic acids such as acids, citraconic acid, itaconic acid and monoester derivatives and diester derivatives thereof, succinic acid monoacryloyloxyethyl ester, succinic acid monomethacryloyloxyethyl ester, acrylonitrile, methacrylonitrile, acrylamide, etc. it can.

  The orange toner of the present invention can contain a release agent as a constituent component. In general, polypropylene wax, polyethylene wax, paraffin wax, Fischer tripish wax, candelilla wax, carnauba wax, rice wax, etc. are frequently used as release agents for toner for electrophotography, but are not limited thereto. Absent. The release agents can be used singly or in combination of a plurality, but 0.1 to 8 parts by weight, preferably 1 to 4 parts by weight with respect to 100 parts by weight of the fixing resin. Anti-offset performance, fixing strength, and rubbing test strength can be obtained. If the amount is less than 1 part by weight, offset tends to occur. If the amount exceeds 8 parts by weight, carrier spent tends to occur, and the image quality is likely to deteriorate.

  The orange toner of the present invention can contain an external additive. External additives include, for example, silica, Teflon (registered trademark) resin powder, zinc stearate powder, lubricant powder such as polyvinylidene fluoride powder, or abrasive such as cerium oxide powder, silicon carbide powder, strontium titanate powder, Or a fluidity-imparting agent such as titanium oxide powder or aluminum oxide powder, an anti-agglomeration agent, or a conductivity-imparting agent such as carbon black powder, zinc oxide powder, antimony oxide powder or tin oxide powder, or white of opposite polarity Fine particles and black fine particles can also be used as a developability improver. These can be used singly or in combination, and are selected so as to have resistance against development stress such as idling.

  When using the two-component developer method, the magnetic fine particles used in the magnetic carrier are one or more of spinel ferrites such as magnetite and gamma iron oxide, and metals other than iron (Mn, Ni, Zn, Mg, Cu, etc.) Magnetoplumbite type ferrites such as spinel ferrite and barium ferrite, and iron or alloy particles having an oxide layer on the surface can be used. The shape may be granular, spherical, or needle-shaped. In particular, when high magnetization is required, it is preferable to use ferromagnetic fine particles such as iron. In view of chemical stability, it is preferable to use magnetoplumbite type ferrites such as spinel ferrite and barium ferrite containing magnetite and gamma iron oxide. By selecting the type and content of the ferromagnetic fine particles, a resin carrier having a desired magnetization can be used. At this time, the magnetic property of the carrier is preferably 30 to 150 emu / g as the magnetization intensity at 1,000 oersted.

  Such a resin carrier is produced by spraying a melt-kneaded product of magnetic fine particles and an insulating binder resin with a spray dryer, or reacting and curing a monomer or prepolymer in an aqueous medium in the presence of the magnetic fine particles. A resin carrier in which magnetic fine particles are dispersed in a condensed binder can be produced.

  On the surface of the magnetic carrier, positive and negative chargeable fine particles or conductive fine particles can be fixed, or a resin can be coated to control the chargeability.

  Silicone resin, acrylic resin, epoxy resin, fluorine resin, etc. are used as the coating material on the surface, and it can be coated with positively or negatively charged fine particles or conductive fine particles. Silicone resin and acrylic resin Is preferred.

  The mixing ratio of the electrophotographic toner of the present invention to the magnetic carrier is preferably 2 to 10 wt% as the toner concentration.

  In the orange toner of the present invention, the charge amount of the toner can be controlled to a desired value by using a charge control agent mixed (internal addition) or mixed (external addition) with the toner particles.

  Examples of the positive charge control agent for toner include modified products of nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonic acid, tetrabutylammonium tetrafluoroborate, and the like. Onium salts such as phosphonium salts and their lake pigments, triphenylmethane dyes and their lake pigments, metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate , Diorganotin borates such as dioctyl tin borate and dicyclohexyl tin borate; these can be used alone or in combination of two or more. Among these, a charge control agent such as a quaternary ammonium salt is particularly preferably used.

  As the negative charge control agent of the toner, an organic metal complex and a chelate compound are effective, and there are a monoazo metal complex, an acetylacetone metal complex, an aromatic hydroxycarboxylic acid, and an aromatic dicarboxylic acid type metal complex. Others include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

  When these charge control agents are internally added to the toner, it is preferable to add 0.1 to 10 wt% with respect to the fixing resin, and since they may be colored by the charge control agent, they are as white or transparent as possible. Select one. Since some charge control agents have skin sensitization depending on the structure, it is necessary to carefully select them.

  The particle size of the orange toner can be measured by various methods. In the present invention, the particle size of the orange toner is measured using a Coulter counter. The aperture was 100 μm, and the number distribution and volume distribution were measured using a Coulter counter TA-II type (Coulter). At this time, 50,000 samples were measured in which the measurement toner was added to the electrolytic solution to which the surfactant was added and dispersed for 1 minute using an ultrasonic disperser. The average particle size of the toner is preferably 2 to 12 μm.

  To prepare the orange toner in the present invention, a fixing resin, CIPigment Orange 11, 20, 20: 1, 23, 35, 64, 67, 69, 73, 74, 75, 77, 78, 81, 99, 114 A master batch in which a colorant selected from the group consisting of a yellow pigment, a red pigment, or a pigment is kneaded in advance in a resin as necessary, and a charge control agent, additives, and a release agent are uniformed as necessary. Combine the dispersed fixing resins and mix thoroughly with a mixer such as a Henschel mixer or super mixer, and then melt and knead them using a hot-melt kneader such as a heating roll, kneader, or extruder to ensure that the materials are adequate. After mixing, the mixture is cooled and solidified, and then finely pulverized and classified to obtain a toner. As a pulverization method at this time, a toner is included in a high-speed air current, the toner collides with a collision plate, and the energy is pulverized by a jet mill method or a particle-particle collision method in which toner particles collide with each other in an air current. A mechanical pulverization method in which toner is supplied between a rotor rotated at high speed and a narrow gap and pulverized can be used. In the jet mill method and the interparticle method, the toner is pulverized by collision energy, so the shape of the pulverized toner particles is relatively sharp, but when using the mechanical pulverization method, the toner is pulverized while being rubbed between the gaps. In addition, the toner surface is easily spheroidized by the frictional heat generated at this time. In particular, in the toner that aims to reduce the particle size and to fix at low temperature, the phenomenon that the toner melts and adheres to the collision plate at the time of pulverization as pointed out in JP-A-7-287413 does not occur. It is also possible to prevent a decrease in toner fluidity, which is a characteristic phenomenon when the particle size is reduced and a low molecular weight wax is contained.

  Further, it can also be obtained by a so-called polymerization method in which a monomer is polymerized in the presence of a colorant, a charge control agent, a wax or the like when polymerized. Further, it can be obtained by a microencapsulation method. The prepared toner can be further mixed with a desired additive, if necessary, with a mixer such as a Henschel mixer to obtain a toner with the additive added externally.

  The developing device of the image forming apparatus of the present invention is selected depending on the moving speed of the electrostatic charge holding member. However, in the case of a high-speed printer or the like in which the moving speed of the electrostatic charge holding member is fast, the development of one developing magnetic roll is not always sufficient. Alternatively, a plurality of development magnetic rolls are used, and development is performed by increasing the development area and extending the development time. When a plurality of developing magnetic rolls are used, a higher developing ability can be obtained as compared with a single developing roll system, so that not only the response to high area image printing and the printing quality are improved, but also in the developer. The toner content can be reduced, and the rotation speed of the developing roll can be reduced, preventing toner scattering and reducing the load on the developer, thereby preventing the carrier spent by the toner and extending the life of the two-component developer. Can be further improved.

  Further, in a developing method using a plurality of developing rolls, unidirectional development in which the developing roll rotates in the forward direction and the forward direction of the electrostatic charge holding member has a high developing ability, but the background fog is likely to occur and the leading edge of the image Chipping and magnetic brushes tend to appear.

  On the other hand, unidirectional development in which the developing roll rotates in the direction opposite to the traveling direction of the electrostatic charge holding member has stable background because there is little background fogging and the magnetic brush has little blurring, although there is a chip at the rear end of the image area. Is obtained. However, since the reverse direction development has a small effective toner amount in contact with the electrostatic charge holding member, the development ability may be small. On the other hand, since the center feed system has both the forward and reverse developing rolls as described above, the above-described disadvantages of the two developing systems can be avoided. A center-feed type developing device is known, for example, from Japanese Examined Patent Publication No. 62-45552.

  Development as described above, that is, development using a two-component developer composed of toner and a magnetic carrier, using at least a plurality of development magnetic rolls, and the development magnetic roll rotating in the forward and forward directions of the electrostatic charge holding member The electrostatic latent image is visualized by a center-feed type developing device having a developing magnetic roll that rotates in the opposite direction to the developing magnetic roll, and the visualized toner image is transferred onto a recording medium, on the electrostatic charge holding member By using the orange toner for electrophotography of the present invention in an image forming apparatus comprising an electrostatic recording process for cleaning a toner image remaining on the recording medium and fixing a toner image transferred onto a recording medium to obtain a recorded image Excellent image, stable amount of toner adhesion can be secured for both character and solid parts, and stable image with no transfer failure against changes in print density It is possible to provide a deposition apparatus.

  Examples of the present invention will be described below, but the present invention is not limited thereby.

Example 1
6 parts by weight of a masterbatch containing 40% by weight of CIPigment Orange 64 (manufactured by Ciba Specialty Chemicals, trade name: CROMOPHTAL ORANGE GP), and polyester resin (1) (outflow start temperature Tfb: 91.0 ° C., softening point) T1 / 2: 108.5 ° C., Mw: 7,400, Mn: 4,950, Tg: 57.6 ° C., acid value: 6.8 mgKOH / g) 31 parts by weight, polyester resin (2) (outflow start temperature) Tfb: 117.3 ° C, softening point T1 / 2: 153.9 ° C, Mw: 118,900, Mn: 4,900, Tg: 56.3 ° C, acid value: 3.7 mgKOH / g) 60 parts by weight, It consists of 0.5 parts by weight of holobis (1,1-diphenyl-1-oxo-acetyl) potassium salt and 2.5 parts by weight of carnauba wax (manufactured by Celerica NODA, trade name: carnauba wax NO1). Charges were premixed by a super mixer, after heat melt kneading with a twin-screw kneader, and pulverized after cooling, then classified by a dry airflow classifier, an average particle diameter to obtain toner base material of 9 .mu.m. Hydrophobic silica (made by Nippon Aerosil Co., Ltd., trade name: R976, primary particle size 7 nm) and inorganic particles (made by Nippon Aerosil Co., Ltd., trade name: RX50, primary particle size 40 nm) with respect to 100 parts by weight of the toner base material. 0.4 parts by weight were added and stirred with a Henschel mixer to adhere hydrophobic silica to the surface of the particles, whereby the toner of Example 1 was obtained.

(Example 2)
9 parts by weight of a masterbatch containing 40% by weight of CIPigment Orange 73 (Ciba Specialty Chemicals, trade name: IRGAZIN DDP ORANGE RA), polyester resin (1) (flow start temperature Tfb: 91.0 ° C., softening point) T1 / 2: 108.5 ° C., Mw: 7,400, Mn: 4,950, Tg: 57.6 ° C., acid value: 6.8 mg KOH / g) 28 parts by weight, polyester resin (2) (outflow start temperature) Tfb: 117.3 ° C, softening point T1 / 2: 153.9 ° C, Mw: 118,900, Mn: 4,900, Tg: 56.3 ° C, acid value: 3.7 mgKOH / g) 60 parts by weight, Implementation using 0.5 parts by weight of holobis (1,1-diphenyl-1-oxo-acetyl) potassium salt and 2.5 parts by weight of carnauba wax (manufactured by Celerica NODA, trade name: carnauba wax NO1) 1 to prepare a toner in the same manufacturing process, to adhere the hydrophobic silica the surface of the particles, and the toner in Example 2.

(Example 3)
7.5 parts by weight of a masterbatch containing 40% by weight of CIPigment Orange 64 (trade name: CROMOPHTAL ORANGE GP, manufactured by Ciba Specialty Chemicals); I. 0.3 parts by weight of a master batch containing 50% by weight of Pigment Red 48: 3 (manufactured by Dainichi Seika Kogyo Co., Ltd., trade name: Red NO. 9), polyester resin (1) (outflow start temperature Tfb: 91.0 ° C. , Softening point T1 / 2: 108.5 ° C., Mw: 7,400, Mn: 4,950, Tg: 57.6 ° C., acid value: 6.8 mgKOH / g) 29.2 parts by weight, polyester resin (2 (Flow start temperature Tfb: 117.3 ° C., softening point T1 / 2: 153.9 ° C., Mw: 118,900, Mn: 4,900, Tg: 56.3 ° C., acid value: 3.7 mgKOH / g) ) 60 parts by weight, 0.5 parts by weight of horobis (1,1-diphenyl-1-oxo-acetyl) potassium salt, 2.5 parts by weight of carnauba wax (manufactured by Celerica NODA, trade name: carnauba wax NO1) Used and made in the same way as Example 1. To prepare a toner by law, the surface of the particles to adhere the hydrophobic silica to obtain a toner of Example 3.

Example 4
7.5 parts by weight of a masterbatch containing 40% by weight of CIPigment Orange 64 (trade name: CROMOPHTAL ORANGE GP, manufactured by Ciba Specialty Chemicals); I. 1 part by weight of a masterbatch containing 50% by weight of Pigment Red 48: 3 (manufactured by Dainichi Seika Kogyo Co., Ltd., trade name: Red NO.9), polyester resin (1) (outflow start temperature Tfb: 91.0 ° C., softening Point T1 / 2: 108.5 ° C., Mw: 7,400, Mn: 4,950, Tg: 57.6 ° C., acid value: 6.8 mg KOH / g) 28.5 parts by weight, polyester resin (2) ( Outflow start temperature Tfb: 117.3 ° C., softening point T1 / 2: 153.9 ° C., Mw: 118,900, Mn: 4,900, Tg: 56.3 ° C., acid value: 3.7 mgKOH / g) 60 Part by weight, 0.5 parts by weight of horobis (1,1-diphenyl-1-oxo-acetyl) potassium salt, 2.5 parts by weight of carnauba wax (manufactured by Celerica NODA, trade name: carnauba wax NO1) Use the same manufacturing method as in Example 1. The toner of Example 4 was prepared by attaching a hydrophobic silica to the surface of the particles.

(Example 5)
8 parts by weight of a masterbatch containing 40% by weight of CIPigment Orange 73 (manufactured by Ciba Specialty Chemicals, trade name: IRGAZIN DDP ORANGE RA); I. 1.5 parts by weight of a masterbatch containing 50% by weight of Pigment Yellow 180 (manufactured by Clariant Japan, trade name: TONER YELLOW HG), polyester resin (1) (outflow start temperature Tfb: 91.0 ° C., softening point T1 / 2: 108.5 ° C., Mw: 7,400, Mn: 4,950, Tg: 57.6 ° C., acid value: 6.8 mg KOH / g) 27.5 parts by weight, polyester resin (2) (outflow start temperature) Tfb: 117.3 ° C, softening point T1 / 2: 153.9 ° C, Mw: 118,900, Mn: 4,900, Tg: 56.3 ° C, acid value: 3.7 mgKOH / g) 60 parts by weight, Using 0.5 parts by weight of holobis (1,1-diphenyl-1-oxo-acetyl) potassium salt and 2.5 parts by weight of carnauba wax (manufactured by Celerica NODA, trade name: carnauba wax NO1) Example 1 to prepare a toner in the same manufacturing method as in the surface of the particles to adhere the hydrophobic silica to obtain a toner of Example 5.

(Example 6)
CIPigment Orange 73 (manufactured by Ciba Specialty Chemicals, trade name: IRGAZIN DDP ORANGE RA) 10 parts by weight of a master batch containing 40% by weight; I. 0.3 parts by weight of a masterbatch containing 50% by weight of Pigment Yellow 155 (manufactured by Clariant Japan, trade name: TONER YELLOW 3GP), polyester resin (1) (outflow start temperature Tfb: 91.0 ° C., softening point T1 / 2: 108.5 ° C., Mw: 7,400, Mn: 4,950, Tg: 57.6 ° C., acid value: 6.8 mg KOH / g) 26 parts by weight, polyester resin (2) (outflow start temperature Tfb: 117.3 ° C, softening point T1 / 2: 153.9 ° C, Mw: 118,900, Mn: 4,900, Tg: 56.3 ° C, acid value: 3.7 mgKOH / g) 60 parts by weight, Implementation using 0.5 parts by weight of 1,1-diphenyl-1-oxo-acetyl) potassium salt and 2.5 parts by weight of carnauba wax (manufactured by Celalica NODA, trade name: carnauba wax NO1) A toner was prepared in the same manner as in Example 1, and hydrophobic silica was adhered to the surface of the particles, whereby the toner of Example 6 was obtained.

(Comparative Example 1)
CIPigment Red 48: 3 (manufactured by Dainichi Seika Kogyo Co., Ltd., trade name: Red NO.9) 2.3 parts by weight of masterbatch, CIPigment yellow 180 (Clariant Japan, trade name: TONER YELLOW HG) ) Master batch containing 6.8 parts by weight, polyester resin (1) (outflow start temperature Tfb: 91.0 ° C., softening point T1 / 2: 108.5 ° C., Mw: 7,400, Mn: 4,950, Tg: 57.6 ° C., acid value: 6.8 mg KOH / g) 27.9 parts by weight, polyester resin (2) (outflow start temperature Tfb: 117.3 ° C., softening point T1 / 2: 153. 9 ° C., Mw: 118,900, Mn: 4,900, Tg: 56.3 ° C., acid value: 3.7 mg KOH / g) 60 parts by weight, holobis (1,1-diphenyl-1-oxo-acetyl) potassium 0.5 parts by weight of salt, carnauba A toner was prepared in the same manner as in Example 1 using 2.5 parts by weight (product name: Carauba wax NO1 manufactured by Celalica NODA), and hydrophobic silica was adhered to the surface of the particles. No. 1 toner.

(Comparative Example 2)
CIPigment Red 184 (manufactured by Clariant Japan, trade name: PERMANENT RUBINE F6B) containing 2 parts by weight of a masterbatch containing 50% by weight and C.I. I. 5 parts by weight of a masterbatch containing 50% by weight of CIPigment yellow 180 (manufactured by Clariant Japan, trade name: TONER YELLOW HG), polyester resin (1) (outflow start temperature Tfb: 91.0 ° C., softening point T1 / 2: 108.5 ° C., Mw: 7,400, Mn: 4,950, Tg: 57.6 ° C., acid value: 6.8 mgKOH / g) 30 parts by weight, polyester resin (2) (outflow start temperature Tfb: 117. 3 ° C., softening point T1 / 2: 153.9 ° C., Mw: 118,900, Mn: 4,900, Tg: 56.3 ° C., acid value: 3.7 mgKOH / g) 60 parts by weight, holobis (1, 1-diphenyl-1-oxo-acetyl) potassium salt 0.5 part by weight, carnauba wax (manufactured by Celerica NODA, trade name: carnauba wax NO1) 2.5 part by weight In to prepare a toner, to adhere the hydrophobic silica the surface of the particles, and the Comparative Example 2 toner.

(Comparative Example 3)
2 parts by weight of masterbatch containing 50% by weight of CIPigment Red 122 (Clariant Japan, trade name: TONER MAGEMTA E02) and 50% by weight of CIPigment yellow 155 (Clariant Japan, trade name: TONER YELLOW 3GP) 4 parts by weight of the master batch, polyester resin (1) (outflow start temperature Tfb: 91.0 ° C., softening point T1 / 2: 108.5 ° C., Mw: 7,400, Mn: 4,950, Tg: 57. 6 ° C., acid value: 6.8 mg KOH / g) 31 parts by weight, polyester resin (2) (flow start temperature Tfb: 117.3 ° C., softening point T1 / 2: 153.9 ° C., Mw: 118,900, Mn : 4,900, Tg: 56.3 ° C., acid value: 3.7 mg KOH / g) 60 parts by weight, horobis (1,1-diphenyl-1-oxo-acetyl) potassium salt 0.5 parts by weight, cal Using 2.5 parts by weight of Uba wax (manufactured by Celalica NODA, trade name: Carnauba Wax NO1), a toner was prepared in the same manner as in Example 1, and hydrophobic silica was adhered to the surface of the particles. Comparative Example 3 toner.

  Next, the toner is mixed and stirred at a ratio of 4.5% by weight with a magnetic carrier whose surface is coated with silicone to prepare a two-component developer, and an electrophotographic laser beam printer using OPC as a photoreceptor. The image was produced at a printing speed of 70 sheets per minute (printing process speed 31.4 cm / sec) at an OPC charging potential of −500 V, a residual potential of −50 V, a developing bias potential of −350 V, and a developing portion contrast potential of 150 V. . The developing machine uses a center-feed type developing device having a developing magnetic roll that rotates in the forward direction (333 rpm) and a developing magnetic roll in which the developing magnetic roll rotates in the forward direction and the forward direction of the electrostatic charge holding member. The development gap (distance between the photoreceptor and the developing roll sleeve) was 0.5 mm, and an image was produced by reversal development. The fixing machine is a thin roll of aluminum cored bar covered with a fluororesin (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer: PFA) tube (thickness 40 μm) and a heater lamp installed in the center. A silicon rubber layer (thickness 7 mm) with a rubber hardness of about 30 degrees is installed on an aluminum core, and the outermost layer is covered with a PFA tube as a backup roll. The fixing condition is a process speed of 31.4 cm / sec. The outer diameter of the heat roll and the backup roll was 60 mm, the pressing load was 60 kgf, and the width of the contact area (nip) between them was about 7 mm.

  Table 1 shows the results of measuring the brightness and saturation of these images.

  As can be seen from the results in Table 1, in Examples 1 to 6, both lightness L * and chroma C * showed high values, and a bright and bright orange image could be provided. On the other hand, in Comparative Examples 1 to 3 prepared by mixing a red pigment and a yellow pigment, color turbulence occurred and both brightness and saturation were low.

Next, these examples were repeatedly printed with an image having a printing density of 1.5%, and the image stability was confirmed. It was confirmed that even when continuous printing of 100,000 pages was repeated for each example, a vivid image was stably obtained without occurrence of offset or fog.

Claims (8)

In an orange toner for electrophotography using at least a fixing resin and a colorant , the colorant is C.I. I. Pigment Orange 64 and C.I. I. An orange toner for electrophotography, comprising a pigment represented by PigmentRed in a range of 1: 0.05 to 1: 0.17. In an orange toner for electrophotography using at least a fixing resin and a colorant , the colorant is C.I. I. Pigment Orange 73 and C.I. I. An orange toner for electrophotography, comprising a pigment represented by Pigment Yellow in a range of 1: 0.0375 to 1: 0.24. 3. The orange toner for electrophotography according to claim 1, wherein the colorant is contained in an amount of 1% to 25%. The electrophotographic orange toner according to any one of claims 1 to 3, comprising at least a fixing resin, a colorant, a release agent, and an external additive, wherein the average particle size of the toner is in the range of 2 to 12 µm. An orange toner for electrophotography, characterized in that there is. 5. The orange toner for electrophotography according to claim 4, wherein the release agent is contained in an amount of 0.1 to 8 parts by weight with respect to 100 parts by weight of the fixing resin. 5. The electrophotographic orange toner according to claim 4, wherein a charge control agent is added, and when the charge control agent is added internally, 0.1 to 10 wt% is added to the fixing resin. An orange toner for electrophotography. The image forming apparatus using the electrophotographic orange toner according to claim 1, wherein the electrostatic charge latent image formed on the electrostatic charge holding member is visualized, and the visualized toner image is obtained. The method comprises an electrostatic image recording step of cleaning a toner image transferred onto a recording medium and remaining on the electrostatic charge holding member, and fixing the toner image transferred onto the recording medium to obtain a recorded image. An image forming apparatus using orange toner for electrophotography. The image forming apparatus using the electrophotographic orange toner according to claim 1, wherein a two-component developer comprising the electrophotographic orange toner and a magnetic carrier is used, and at least a plurality of developing magnetic materials are used. An electrostatic charge latent image is developed by a center-feed type developing device using a roll, the developing magnetic roll having a developing magnetic roll rotating in the forward direction and a developing magnetic roll rotating in the forward direction with respect to the electrostatic charge holding member. The image is visualized, the visualized toner image is transferred onto a recording medium, the toner image remaining on the electrostatic charge holding member is cleaned, and the toner image transferred onto the recording medium is fixed to fix the recorded image. An image forming apparatus using an orange toner for electrophotography characterized by comprising an electrostatic recording step.