Toner and preparation method thereof

Abstract

The present invention discloses a toner comprising colored resin particles of a binder resin and a colorant and an external additive, the external additive comprising one or more of a metal-polymer, the metal in the metal-polymer being one of Cu, Sn, Zn, Pd, Au, Ag, and Cd, the relative molecular mass of the metal-polymer being between 15000 and 20000, the relative molecular mass of the metal-polymer being between 15000 and 20000, and the relative molecular mass of the metal-polymer being between 15000 and 20000. The content of the metal-polymer is 1%-3% relative to the mass ratio of the colored resin particles; the toner has stable charging performance, is difficult to cause image quality deterioration caused by fogging and the like even if a plurality of sheets are continuously printed, has excellent fluidity, can effectively inhibit increase of charging amount of the toner in a low-temperature and low-humidity environment, and can still stably print and obtain good image quality in the environment.

Description

Technical Field

[0001] The invention belongs to the technical field of printing and copying developers, and in particular relates to a toner and a preparation method thereof. Background Art

[0002] With the development of the times, electronic photo printing has become more and more common. The most widely used method for printing color photos is xerography, which is dry printing, used for rapid sequential analog copying, and later combined with digital computers to form modern laser printers. Since its invention, laser printing electronic photography has maintained an unchanged six-step basic process: charging, exposure, development, transfer, fusing and cleaning. During the exposure process, the charged photosensitive surface is exposed to the laser beam, which writes the electrostatic latent image onto the surface of the electrosensitive surface. As the drum rotates, the latent image passes through a hopper containing toner. The toner is electrostatically attracted to the latent image on the electrosensitive surface, causing the latent image to be covered by a layer of toner. The image is transferred from the electrosensitive surface to the paper through a contact transfer roller and fused using heat and pressure to print. Although this printing speed has been greatly improved compared to ink-based methods, xerography as a way to print products is still under exploration, especially the research on the key consumable toner.

[0003] Toner is mainly composed of resin, pigment, additives, etc. However, there are still problems in the past toner. During the process of continuous printing of multiple sheets, due to the influence of various factors such as the mechanical stress of the developing device, the external additives are not well mixed in the toner, and only exist on the surface of the particles or are free from the surface of the toner. Therefore, the function of the external additives is reduced, and it is difficult to provide the toner particles with the ability to carry static electricity during the continuous exposure process. The external additives are immersed in the toner particles, and the toner particles adhere to the surface of the photosensitive body. In the later stage of the large-scale printing process, gray fog is easily generated, which leads to the deterioration of the image quality. The external additives freed from the surface of the toner particles lead to the deterioration of the charge of the photosensitive body surface, resulting in the deterioration of the printing durability of the toner and the image quality. Especially under high temperature and high humidity conditions, film formation leads to a significant deterioration of the image quality.

[0004] There is an urgent need to discover a new type of external additive to solve the problems existing in the existing technology. Summary of the invention

[0005] The present invention aims at the problems existing in the prior art and provides a toner, comprising a binder resin and colored resin particles of a colorant and an external additive, wherein the external additive comprises one or more of metal-polymers, and the general formula of the metal-polymer is as follows:

[0006]

[0007] Wherein, M is one of Cu, Sn, Zn, Pd, Au, Ag, Cd, R 1 is a H atom, R 2 is an alkyl group having 1 to 12 carbon atoms;

[0008] Furthermore, the relative molecular mass of the external additive is between 15000 and 20000;

[0009] Preferably, the relative molecular mass of the external additive is between 15000 and 18000;

[0010] Further preferably, the relative molecular mass of the external additive is between 16000 and 18000;

[0011] Furthermore, the content of the external additive is 1% to 3% of the mass ratio of the colored resin particles;

[0012] Furthermore, the binder resin comprises one of polyester resin and styrene acrylic resin or a combination of the two;

[0013] Preferably, the binder resin is a polyester resin;

[0014] Further, the polyester resin is a reaction product of an alcohol compound and a carboxylic acid compound, wherein the alcohol compound comprises one or more combinations of bisphenol A ethylene oxide adduct, butanediol, and diols having 6 to 12 carbon atoms, and the carboxylic acid compound comprises one or more combinations of aromatic diacids such as phthalic acid, isophthalic acid, terephthalic acid, tert-butylisophthalic acid, 2,6-naphthalene dicarboxylic acid, and 4,4'-biphenyl dicarboxylic acid and / or one or more combinations of aliphatic diacids such as succinic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, and citraconic acid;

[0015] Further, the alcohol compound includes a thiol compound, and the thiol compound can be selected from one or more combinations of benzenedithiol, a branched dithiol with 5 to 10 carbon atoms or a branched dithiol, and the molar ratio of the thiol compound to the alcohol compound is between 0.05 and 0.2;

[0016] A second aspect of the present invention provides a method for preparing a toner, comprising a step of preparing an external additive, a step of preparing colored resin particles, and a step of preparing the toner by using the external additive and the colored resin particles;

[0017] The preparation of the metal-polymer external additive comprises the following steps: styrene, acrylate compounds, acrylic acid, 1-dodecanol, 2,2'-azobis(2-methylpropionitrile) and 2,2'-azobis(2-methylbutyronitrile) are mixed and stirred evenly, then dissolved in toluene at 70 to 100° C., stirred within the temperature range for 10 to 25 hours, then added with excess methanol, separated and precipitated, and dried to obtain a polymer, then the polymer and metal nanoparticles are ground until a uniform fine powder is obtained, and then transferred to a ball mill for ball milling for 10 to 24 hours to obtain the metal-polymer external additive;

[0018] The preparation of the colored resin particles comprises the following steps: adding a carboxylic acid compound, an alcohol compound and a catalyst into a reaction container, stirring at 70-150° C. for 5-8 hours under nitrogen protection to obtain a polyester resin, dispersing the polyester resin with a homogenizer for 3-5 minutes, adding an aqueous solvent, controlling the solid content to 10-18%, obtaining a resin emulsion through an oxidation reaction, adding a dispersed colorant and a release agent to the resin emulsion, adjusting the pH to 5.5-7 under the action of a polymerization initiator, slowly heating to 70-85° C., maintaining for 1-2 hours, then cooling to 50-65° C., maintaining for 2-3 hours, and cooling to room temperature to obtain colored resin particles;

[0019] The toner preparation comprises adding an external additive to the above-mentioned colored resin particles to prepare the toner.

[0020] Further, the catalyst comprises one or more combinations of titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, dibutyltin dichloride, dibutyltin oxide, and diphenyltin oxide, and the catalyst accounts for 0.1% to 0.5% of the total material mass ratio;

[0021] Further, the colorant comprises one of black pigment, yellow pigment, red pigment and blue pigment; the release agent comprises one or more combinations of ester wax, carnauba wax, rice bran wax, candelilla wax, wood wax, jojoba oil, beeswax, montan wax, ozokerite, white ceresin, paraffin wax, microcrystalline wax and Fischer-Tropsch wax;

[0022] Furthermore, the toner has an average particle size between 6.7 and 7.1 μm, a particle size dispersion between 1.18 and 1.26, and a sphericity between 0.97 and 0.99.

[0023] Beneficial effects:

[0024] As described above, the colorant involved in the present invention selects to use one or more metal-polymers as external additives to give the colorant stable charging performance, and the external additives and the colorant can be better mixed. Even if multiple consecutive printings are performed, it is difficult to cause image quality degradation caused by fogging, and it has excellent fluidity. Not only that, with the addition of the external additive, it can also effectively suppress the increase in the colorant charge under low temperature and low humidity environments, and still print stably in this environment to obtain good image quality; in addition, by introducing thiol compounds into the colorant polyester resin, the above-mentioned performance indicators of the colorant can be further improved. DETAILED DESCRIPTION

[0025] The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. Where specific conditions are not indicated in the examples, they are carried out under conventional conditions or under conditions recommended by the manufacturer. Where the manufacturers of reagents or instruments are not indicated, they are all conventional products that can be purchased commercially.

[0026] In an embodiment of the present invention, a toner is provided, comprising a binder resin, colored resin particles of a colorant, and an external additive.

[0027] External additives

[0028] The external additives in the present invention include one or more metal-polymers. The general formula and synthesis process of the metal-polymers are as follows:

[0029]

[0030] Wherein, M is one of Cu, Sn, Zn, Pd, Au, Ag, Cd, R 1 is a H atom, R 2 It is an alkyl group having 1 to 12 carbon atoms.

[0031] <Preparation of Metal-Polymer>

[0032] Styrene, acrylate compounds, acrylic acid, 1-dodecanol, 2,2'-azobis(2-methylpropionitrile) and 2,2'-azobis(2-methylbutyronitrile) are mixed and stirred evenly, then dissolved in toluene at 70-100°C, stirred within the temperature range for 10-25 hours, then an excess of methanol is added, the precipitate is separated and dried to obtain a polymer, and then the polymer is ground with metal nanoparticles until a uniform fine powder is obtained, and then transferred to a ball mill for ball milling for 10-24 hours to obtain a metal-polymer external additive.

[0033] In the present invention, the relative molecular mass of the metal-polymer is between 15,000 and 20,000.

[0034] The relative molecular weight of the metal-polymer is preferably between 15,000 and 18,000; more preferably between 16,000 and 18,000.

[0035] The metal-polymer is added in an amount of 1 to 3 parts by mass relative to 100 parts by mass of the colored resin particles.

[0036] In the present invention, the metal grows in a clustered manner with the polymer, and the metal cluster can form a coordination bond with the polymer. There are two positions of the metal cluster in the metal-polymer, one is that the metal cluster is located at the end group of the polymer, and the other is that the metal cluster is located in the middle part of the polymer chain.

[0037] The binder resin in the present invention can be selected from conventional resins in the art, including but not limited to one of polyester resin and styrene acrylic resin or a combination of the two; preferably, the binder resin in the present invention is polyester resin.

[0038] Polyester resin

[0039] The polyester involved in the present invention can be prepared by conventional synthesis methods in the art, using condensation-polymerizable monomers such as aliphatic, alicyclic and aromatic multifunctional carboxylic acids, alkyl esters and polyols, their ester compounds, hydroxyl carboxyl groups, etc., through direct esterification reaction, ester exchange reaction, etc., to prepare the polyester resin that can be used in the present invention in an aqueous medium.

[0040] In the present invention, the polyester resin is preferably prepared by direct esterification reaction of carboxylic acid compounds and alcohol compounds in the presence of a catalyst.

[0041] <Synthesis of Polyester Resin>

[0042] A carboxylic acid compound, an alcohol compound and a catalyst are added into a reaction container, and the mixture is stirred and reacted at 70 to 150° C. for 5 to 8 hours under nitrogen protection to obtain a polyester resin.

[0043] In the present invention, the polycondensation reaction of the polyester resin is performed at a temperature lower than or equal to 150°C.

[0044] The reaction temperature is preferably higher than or equal to 70°C but not more than 150°C; more preferably higher than or equal to 110°C but not more than 140°C.

[0045] It is preferable to set the reaction temperature to 70° C. or higher, because a decrease in reactivity due to deterioration in monomer solubility or catalyst activity does not occur, and an increase in molecular weight is not inhibited. It is also preferable to set the reaction temperature to not more than 150° C., because production can be performed at low energy consumption. It is also preferable that no discoloration of the resin occurs or no decomposition occurs on the polyester or the like produced.

[0046] The catalyst in the present invention is an organic metal catalyst. Non-limiting examples of the organic metal catalyst include: organic tin compounds, organic titanium compounds, organic halogenated tin compounds, rare earth metal catalysts and the like.

[0047] Specifically, scandium (Sc), yttrium (Y), and lanthanides such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu) can be effectively used as catalysts containing rare earth metals. These elements are particularly effective when used as alkylbenzene sulfonates, alkyl sulfates, trifluoromethanesulfonate structures, and the like. Examples of trifluoromethanesulfonates can be represented by the structural formula X(OSO 2 CF 3 ) 3 In the above formula, X represents a rare earth metal element, and X is particularly preferably scandium (Sc), yttrium (Y), ytterbium (Yb), samarium (Sm), or the like.

[0048] In the embodiment of the present invention, the catalyst is preferably one or a combination of organic tin compounds and / or organic titanium compounds, wherein the organic titanium compound comprises one or more combinations of titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, and titanium tetrabutoxide, and the organic tin compound comprises one or more combinations of dibutyltin dichloride, dibutyltin oxide, and diphenyltin oxide.

[0049] Particularly preferably, the catalyst in the embodiment of the present invention is dibutyltin oxide, and its feed amount accounts for 0.1-0.5 mol% of the total material amount.

[0050] In the present invention, the molecular weight of the polyester resin is 5,000-1,000,000, more preferably the weight average molecular weight (Mw) is 7000-500,000, the number average molecular weight (Mn) is 2,000-10,000, and the high molecular weight distribution Mw / Mn is 1.5-100, further preferably 2-60 according to the molecular weight of tetrahydrofuran (THF) soluble matter measured by gel permeation chromatography (GPC) method, and the molecular weight of the resin is calculated by measuring the molecular weight of THF soluble matter in THF solution using GPC·HLC-8120 (manufactured by Tosoh Corporation) and column·TSKgel superHM-M (15 cm, manufactured by Tosoh Corporation), and using a molecular weight calibration curve generated from a monodisperse polystyrene standard sample. The acid value of the polyester resin (in terms of the amount of KOH required to neutralize 1 g of the resin) can be selected to be 1-30 mg KOH / g on the grounds that the above molecular weight distribution is easily obtained, the granulation property of the toner particles is easily maintained in the emulsion dispersion method, and the favorable environmental stability (stability of the charge property when the temperature or humidity changes) of the obtained toner is easily maintained. The acid value of the polyester resin can be adjusted by controlling the carboxyl group at the end of the polyester, that is, adjusting the mixing ratio and reaction rate of the polycarboxylic acid and the polyol in the raw material.

[0051] In addition, from the viewpoint of the balance between the storage stability and the fixability of the toner, the glass transition temperature of the amorphous polymer that can be used in this embodiment can be selected to be 35 to 100°C, and more preferably 50 to 80°C. When the glass transition temperature is lower than 35°C, there is a tendency that the toner easily causes blocking (a phenomenon in which toner particles aggregate to form lumps) during storage or in a developer. On the other hand, when the glass transition temperature exceeds 100°C, the fixation temperature of the toner becomes high, which is not optional. The softening point of the amorphous polymer can be selected to be in the range of 80-130°C, and more preferably in the range of 90-120°C. When the softening point is lower than 80°C, the image stability of the toner and the toner after fixation and after storage is drastically deteriorated. When the softening point is higher than 130°C, the low-temperature fixability is deteriorated. The softening point of an amorphous polymer represents the intermediate temperature between the melting start temperature and the melting end temperature measured by a flow tester (trade name CFT-500C; manufactured by Shimadzu Corporation) under the conditions of preheating: 80°C / 300 seconds, plunger pressure: 0.980665 MPa, mold size: heating rate: 3.0°C / min.

[0052] The polyester resin in the present invention can be selected from conventional commercial polyester resins, or can be prepared by polymerization of carboxylic acid compounds and alcohol compounds.

[0053] Carboxylic acid compounds

[0054] The carboxylic acid compounds of the present invention include compounds having two or more carboxyl groups in a single molecule, among which dicarboxylic acids contain two carboxyl groups in one molecule. The carboxylic acid compounds of the present invention include aromatic diacids, aliphatic diacids and polyfunctional carboxylic acids, examples of which include oxalic acid, glutaric acid, succinic acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonane diacid, decanedioic acid, undecanedioic acid, dodecanedioic acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-carboxylic acid, malic acid, citric acid, hexahydroterephthalic acid, malonic acid, pimelic acid, tartaric acid, mucic acid , phthalic acid, isophthalic acid, terephthalic acid, tert-butylisophthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, terephthalic acid, isophenylene glycolic acid, p-phenylene glycolic acid, o-phenylene glycolic acid, diphenylacetic acid, 4,4'-biphenyl dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, anthracene dicarboxylic acid, cyclohexane dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, etc.; as polyfunctional carboxylic acids other than dicarboxylic acids, for example, trimellitic anhydride, pyromellitic acid, naphthalene tricarboxylic acid, naphthalene tetracarboxylic acid, pyrene tricarboxylic acid, pyrene tetracarboxylic acid, etc. can also be mentioned.

[0055] Preferably, the aromatic diacid comprises one or more combinations of phthalic acid, isophthalic acid, terephthalic acid, tert-butylisophthalic acid, 2,6-naphthalene dicarboxylic acid, and 4,4'-biphenyl dicarboxylic acid.

[0056] Preferably, the aliphatic diacid comprises one or more combinations of succinic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, and citraconic acid.

[0057] Considering that the polyester resin has good non-crystalline properties, it is particularly preferred that the aromatic diacid is terephthalic acid; and the aliphatic diacid includes one or a combination of fumaric acid and succinic acid.

[0058] The non-crystalline characteristics of the above-mentioned polyester resin are also called amorphous polyester resin, and "crystallinity" means that a clear endothermic peak can be distinguished by differential scanning calorimetry (DSC) rather than a gradual endothermic change; more specifically, the half-width of the endothermic peak measured at a heating rate of 10°C / min is within the range of 15°C. On the contrary, a resin that produces an endothermic peak with a half-width exceeding 15°C or a resin that has no clear endothermic peak indicates that it is non-crystalline (amorphous).

[0059] Alcohol compounds

[0060] The alcohol compound in the present invention includes a polyol compound, i.e., a compound having two or more hydroxyl groups in one molecule, among which a diol is a compound having two hydroxyl groups in one molecule, and examples thereof include, for example, ethylene glycol, propylene glycol, butanediol, diethylene glycol, cyclohexanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, etc. As polyols other than diols, for example, glycerol, pentaerythritol, hexamethylolmelamine, hexamethylolmelamine, tetramethylolbenzoguanamine, tetraethylbenzoguanamine, etc. can also be cited.

[0061] Considering that monomers with a main structural carbon number greater than or equal to 6 are easier to prepare, and monomers with a main structural carbon number less than or equal to 12 have a suitable molecular size and the reaction activity will not be reduced due to restricted molecular motion, the above-mentioned alcohol compounds preferably include one or more combinations of 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[0062] Particularly preferably, the diol having 6 to 12 carbon atoms is 1,6-hexanediol.

[0063] The alcohol compound in the present invention also includes bisphenol A ethylene oxide adduct; wherein the ethylene oxide adduct can effectively inhibit the delocalization effect caused by the resonance stabilization between the hydroxyl group and the aromatic ring in the bisphenol A structure, and the addition of the ethylene oxide adduct can strengthen the nucleophilic attack of the diol on the polycarboxylic acid, so that the molecular weight growth and polymerization degree progress can be maintained at a good level.

[0064] As a preferred embodiment, the alcohol compound in the present invention includes a thiol compound, and a dithiol compound is particularly preferred, which refers to a dithiol structure containing two thiol functional groups in the molecule, examples of which include, for example, benzenedithiol, a branched dithiol with 5 to 10 carbon atoms or one or more combinations of dithiols containing branches.

[0065] Preferably, the thiol compound comprises one or more combinations of 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, and biphenyl-4,4'-dithiol.

[0066] In addition, studies have found that a small amount of butanediol or propylene glycol in the monomer of the alcohol compound can more effectively improve the developability and preservation properties. It is particularly preferred that the alcohol compound also contains butanediol.

[0067] In the embodiment of the present invention, the molar ratio of thiol compounds to alcohol compounds is between 0.05 and 0.2; the molar ratio of bisphenol A ethylene oxide adduct to alcohol compounds is between 0.3 and 0.5, and the molar ratio of aromatic diacids to total carboxylic acid compounds is between 0.2 and 0.4.

[0068] <Preparation of Toner>

[0069] The method for preparing a toner in the present invention comprises an emulsification step, a polymerization step, and adding an external additive to colored resin particles to prepare the toner:

[0070] <Emulsification step>

[0071] The prepared polyester resin is dispersed in a homogenizer for 3 to 5 minutes, an aqueous solvent is added, and the solid content is controlled to be 10 to 18%, and then mPEG-SH and / or HS-PEG-SH are added, and a resin emulsion is obtained after reaction by air oxidation method or potassium ferrocyanide oxidation method;

[0072] Examples of the aqueous solvent include water such as distilled water and ion-exchanged water, and alcohols. It is particularly preferred that the water-soluble solvent is only water.

[0073] Among them, mPEG-SH is methoxy polyethylene glycol thiol, HS-PEG-SH is dithiol polyethylene glycol, and the molecular weights of the above two substances can be listed as: 550, 750, 1000, 2000, 3400, 5000, 10k, 20k, 40k, and the particularly preferred molecular weight is one or a combination of 1000 and 2000.

[0074] Among them, the dispersing equipment used in the emulsification step includes a homogenizer, a homogenizer, a pressure mixer, an extruder and a medium disperser. It is particularly preferred to use a homogenizer, wherein the speed of the homogenizer is particularly preferably 3000 to 5000 rpm;

[0075] <Polymerization Step>

[0076] Add dispersed colorant and release agent to the above resin emulsion, adjust the pH to 5.5-7 under the action of polymerization initiator, slowly heat to 70-85°C, stir at high speed, keep for 1-2 hours, then cool to 50-65°C, keep for 2-3 hours, and after cooling to room temperature, obtain colored resin particles of 100nm-200nm.

[0077] Colorants

[0078] The colorant dispersion contains a colorant, wherein the colorant dispersion is prepared by dispersing and dissolving the colorant, and preferred examples of devices commonly used to disperse the colorant include medium-type dispersers such as a rotary cutter homogenizer, a ball mill, a sand mill or a grinder, and a high-pressure counter-collision disperser.

[0079] These colorants can be used to prepare a colorant dispersion by dispersing them in an aqueous solution using a homogenizer and an ionic surfactant having polarity.

[0080] The colorant may be selected from the perspectives of hue angle, chromaticity, brightness, weather resistance, OHP permeability, and dispersibility in the toner. The amount of the colorant added to the toner of the exemplary embodiment is preferably about 2 parts by mass to about 15 parts by mass relative to 100 parts by mass of the polyester resin contained in the toner.

[0081] The colorant used in the exemplary embodiment may be a known colorant such as a black pigment, a yellow pigment, a red pigment, or a blue pigment.

[0082] Examples of the black pigment include carbon black and magnetic powder.

[0083] Examples of the yellow pigment include Hansa Yellow, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Threne Yellow, Quinoline Yellow, and Permanent Yellow NCG.

[0084] Examples of red pigments include Bengal, Red Lake, Fast Red 4R, Lithol Red, Brilliant Magenta 3B, Brilliant Magenta 6B, DuPont Oil Red, Pyrazolone Red, Rhodamine B Lake, Red G Lake, Rose Bengal, Eosin, and Alizarin Lake.

[0085] Examples of the blue pigment include Berlin blue, cobalt blue, basic lake blue, Victoria blue lake, fast sky blue, indanthrene blue BC, aniline blue, ultramarine blue, Chalcoil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, and malachite green oxalate.

[0086] Mixtures of any of these colorants may be used, and may be used in a solid solution state.

[0087] Release agent

[0088] The toner of the present invention also contains a release agent, examples of which include plant waxes such as ester wax, carnauba wax, rice bran wax, candelilla wax, wood wax, jojoba oil, etc.; animal waxes such as beeswax, etc.; mineral waxes or petroleum waxes such as montan wax, ozokerite, white ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc.; and modified products thereof may also be used.

[0089] The melting point of the wax is preferably 60° C. or higher, more preferably 65° C. or higher, and further preferably 70° C. or higher. This is because the wax having a melting point within the above range can suppress the fluidity of the toner and filming on the photoreceptor.

[0090] The above wax is dispersed in water together with an ionic surfactant, a polymer electrolyte such as a polymer acid and a polymer base, and then micronized by using a homogenizer or a pressure release type disperser that can apply a strong shear force while heating to a temperature at or above the melting point. In this way, a wax dispersion having particles with a particle size of less than or equal to 1 μm can be prepared.

[0091] The weight average particle size of the wax particles in the aqueous medium is preferably less than or equal to 1 μm, more preferably 100 nm to 700 nm, and even more preferably 100 nm to 500 nm, because setting the weight average particle size of the wax particles within the above range can easily control the particle size of the agglomerated particles and can obtain a good effect as a release agent.

[0092] The amount of the wax added to the toner of the exemplary embodiment is preferably about 2 parts by mass to about 15 parts by mass with respect to 100 parts by mass of the polyester resin contained in the toner.

[0093] Polymerization initiator

[0094] In the polymerization process of the present invention, a polymerization initiator is added, and a known polymerization initiator can be used. Specifically, for example, ammonium persulfate, potassium persulfate, sodium persulfate, 2,2'-azobis(2-methylpropionamide) dihydrochloride, tert-butyl peroxy-2-ethylhexanoate, isopropyl perpivalate, tert-butyl perlaurate, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, di-tert-butyl peroxide, tert-butyl isopropyl peroxide, diisopropyl peroxide ... Diisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 1,4-bis(tert-butylperoxycarbonyl)cyclohexane, 2,2-bis(tert-butylperoxy)octane, 4,4-bis(tert-butylperoxyisopropyl)valeric acid (variable late) n-butyl ester, 2,2-bis(tert-butylperoxy)butane, 1,3-bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, di-tert-butyl diperoxyisophthalate, 2,2-bis(4,4-di-tert-butylperoxycyclohexyl)propane, di-tert-butyl peroxy α-methylsuccinate, di-tert-butyl peroxydimethylglutarate, hexahydroterephthalic acid peroxide Di-tert-butyl ester, di-tert-butyl peroxyazelaton, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, diethylene glycol-bis(tert-butylperoxycarbonate), di-tert-butyl peroxytrimethyladipate, tri(tert-butylperoxy)triazine, vinyl-tri(tert-butylperoxy)silane, 2,2'-azobis(2-methylpropionamidine dihydrochloride), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine], 4,4'-azobis(4-cyanovaleric acid), etc.

[0095] Particularly preferably, the polymerization initiator in the present invention comprises one or a combination of potassium persulfate or ammonium persulfate.

[0096] Other additives

[0097] In the present invention, if necessary, known auxiliary agents may be mixed alone or in combination, as long as they do not affect the results of the present invention, for example, flame retardants, flame retardant auxiliary agents, polishing agents, waterproofing agents, water repellents, magnetic bodies, inorganic fillers (surface modifiers), antioxidants, plasticizers, surfactants, dispersants, lubricants, fillers, adhesives, charge control agents, etc. may be added. These auxiliary agents may be mixed at any time during the production of the coating agent.

[0098] Regarding the polyester resin particle size, the average particle size (volume average particle size) is preferably less than 1 μm, more preferably 50 to 300 nm, and particularly preferably 100 to 200 nm. When the average particle size is less than 50 nm, the polyester resin particles become stable particles in the dispersion and are difficult to agglomerate together. When the average particle size exceeds 1 μm, the aggregation potential of the resin particles is enhanced, making the colorant particles easier to prepare, but the particle size distribution will be expanded.

[0099] The preparation of the toner in the present invention further comprises adding an external additive to the above-mentioned colored resin particles to prepare the toner.

[0100] Toner properties

[0101] Optionally, the volume average particle size is measured using Coulter Multi-sizer II (trade name, manufactured by Coulter Company) with an aperture of 50 μm. In this case, the toner is dispersed in an electrolyte aqueous solution (Isoton aqueous solution) by ultrasonic treatment for more than 30 seconds and then used for measurement. A relationship curve between the measured force division and the divided particle size range is drawn, and the volume cumulative distribution is plotted from the smallest particle size. The particle size with a cumulative 50% is defined as the average particle size. The average particle size of the toner is between 6.7 and 7.1 μm.

[0102] The particle size reaching 16% accumulation is defined as the particle size corresponding to volume D16V and number D16P, and the particle size reaching 84% accumulation is defined as the particle size corresponding to volume D84V and number D84P. These values ​​can be used to calculate the average particle size distribution index in the present invention, that is, the particle size dispersion of the colorant. The preferred particle size dispersion in the present invention is 1.18 to 1.26.

[0103] In addition, the sphericity of the toner in the present invention is 0.97 to 0.99.

[0104] Example

[0105] Preparation of metal-polymer particles

[0106] The metal-polymer particle preparation comprises the following steps: 2.5 mol (260 g) of styrene, 0.22 mol (28.2 g) of n-butyl acrylate, 0.1 mol (7.21 g) of acrylic acid, 0.3 mol (55.9 g) of 1-dodecanol, 0.05 mol (8.21 g) of 2,2'-azobis(2-methylpropionitrile) and 0.05 mol (9.61 g) of 2,2'-azobis(2-methylbutyronitrile) are mixed and stirred until homogeneous. 500 mL of toluene is placed in a reaction vessel with an overhead stirrer and heated to 80°C. Next, the polymerization mixture is dissolved in toluene and stirred at 80°C for 25 hours. The resulting polymer is precipitated into excess methanol, separated and dried to obtain poly(styrene-butyl acrylate). 20 g of the prepared poly(styrene-butyl acrylate) was ground with 0.2 g of copper nanoparticles, 0.2 g of tin nanoparticles, 0.2 g of zinc nanoparticles, 0.2 g of palladium nanoparticles, 0.2 g of gold nanoparticles, 0.2 g of silver nanoparticles, and 0.2 g of cadmium nanoparticles in a mortar until uniform fine powder was obtained. The mixture was then transferred to a ball mill and ball milled for 24 hours to obtain poly(styrene-copper-butyl acrylate) T1 with a molecular weight of 18,000, poly(styrene-tin-butyl acrylate) T2 with a molecular weight of 16,000, poly(styrene-zinc-butyl acrylate) T3 with a molecular weight of 17,000, poly(styrene-palladium-butyl acrylate) T4 with a molecular weight of 20,000, poly(styrene-gold-butyl acrylate) T5 with a molecular weight of 15,000, poly(styrene-silver-butyl acrylate) T6 with a molecular weight of 19,000, and poly(styrene-cadmium-butyl acrylate) T7 with a molecular weight of 20,000.

[0107] Preparation of colorant dispersion

[0108] 30g of carbon black (Cabot Corporation), 7.5g of sodium dodecyl sulfate and 62.5g of water were stirred and pre-dispersed at room temperature, and then the dispersion was added into a high-speed dispersant for dispersion. After 2 hours of dispersion, a colorant dispersion was obtained. The particle size was measured by a nanoparticle size analyzer to be 181nm and the solid content was 30%.

[0109] Preparation of release agent dispersion

[0110] 30g of carnauba wax (RC-160, produced by TOA Kasei Co., Ltd.), 7.5g of sodium lauryl sulfate and 62.5g of water were stirred and dissolved at 90°C, and then the mixture was quickly added to a high-speed dispersant for dispersion for 2 hours to obtain a milky wax dispersion. The particle size was measured by a nanoparticle size analyzer to be 158nm and the solid content was 30%.

[0111] Colored resin particle synthesis example 1

[0112] 0.01 mol (1.66 g) of terephthalic acid, 0.01 mol (1.16 g) of fumaric acid, 0.01 mol (1.18 g) of succinic acid, 0.025 mol (7.90 g) of bisphenol A ethylene oxide adduct, 0.004 mol (0.472 g) of butanediol, 0.005 mol (0.590 g) of 1,6-hexanediol and 0.0979 g (0.00032 mol) of dibutyltin oxide were added into a reaction vessel, stirred under nitrogen protection, and polycondensed at 130°C for 7 hours, and then continued to react at 150°C for 7 hours to obtain a polyester resin.

[0113] The prepared polyester resin was dispersed in a homogenizer at 3000 rpm for 3 minutes, water was added to adjust the solid content to 10%, and then 0.003 mol mPEG-SH-1000 (mPEG-SH-1000 represents the molecular weight of mPEG-SH is 1000) was added. After air oxidation, the polyester resin was obtained by high-speed stirring and dispersion.

[0114] Take 100 parts by mass of the above polyester resin, add 10 parts by mass of a colorant dispersion (30% solid content) and 10 parts by mass of a release agent dispersion (30% solid content), adjust the pH to 7 under the action of potassium persulfate, slowly heat to 75°C, maintain for 2 hours, then cool to 50°C, maintain for 2 hours, and then obtain colored resin particles A1.

[0115] Colored resin particle synthesis example 2

[0116] 0.01 mol (1.66 g) of terephthalic acid, 0.01 mol (1.16 g) of fumaric acid, 0.01 mol (1.18 g) of succinic acid, 0.02 mol (6.32 g) of bisphenol A ethylene oxide adduct, 0.004 mol (0.472 g) of butanediol, 0.005 mol (0.590 g) of 1,6-hexanediol and 0.0979 g (0.00032 mol) of dibutyltin oxide were added into a reaction vessel, stirred under nitrogen protection, and polycondensed at 130°C for 7 h, and then 0.002 mol (0.273 g) of 1,5-pentanedithiol and 0.003 mol (0.451 g) of 1,6-hexanedithiol were added, and the reaction was continued at 150°C for 7 h to obtain a polyester resin.

[0117] The prepared polyester resin was dispersed in a homogenizer at 3000 rpm for 3 minutes, water was added to adjust the solid content to 10%, and then 0.003 mol mPEG-SH-1000 (mPEG-SH-1000 represents the molecular weight of mPEG-SH is 1000) was added. After air oxidation, the polyester resin was obtained by high-speed stirring and dispersion.

[0118] Take 100 parts by mass of the above polyester resin, add 10 parts by mass of a colorant dispersion (30% solid content) and 10 parts by mass of a release agent dispersion (30% solid content), adjust the pH to 7 under the action of potassium persulfate, slowly heat to 75°C, maintain for 2 hours, then cool to 50°C, maintain for 2 hours, and then obtain colored resin particles A2.

[0119] Example 1

[0120] Preparation of Toner-S1

[0121] Toner S1 was obtained by taking 100 parts by mass of the colored resin particles A1 and adding 1 part by mass of the metal-polymer particles T1.

[0122] The preparation methods of toners S2 to S12 in Examples 2 to 9 and Comparative Examples 1 to 3 are the same as that of S1 in Example 1, except that the formula ratio is adjusted. The specific ratios are shown in Table 1:

[0123] Table 1

[0124]

[0125] Printing effect evaluation

[0126] The above-mentioned toner was put on a machine to test the printing effect. The test process was: a continuous printing test of 50 million sheets was carried out under normal temperature and humidity (20°C / 50%RH) environment. The test results are shown in Table 2 below.

[0127] Preservation evaluation

[0128] 10g of toner was placed in an open round container, placed at 50℃ and 60% humidity for 72h, then gently transferred to a container containing toner, and visually observed whether the toner was condensed. If no condensation was observed on the toner surface, it means that the preservation is excellent; if there is condensation on the toner surface, but it can be eliminated without vibration during transfer and does not affect the actual printing effect, it means that the preservation is good; if there is condensation on the toner surface, it cannot be eliminated by vibration during transfer, it means that the preservation is poor. The evaluation results are shown in Table 2.

[0129] Table 2

[0130]

[0131] It should be noted that, according to the explanation and elaboration of the above description, those skilled in the art to which the present invention belongs may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some equivalent modifications and changes to the present invention should also be within the scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the invention.

Claims

1. A toner, characterized in that: The colored resin particles include a binder resin and a colorant, and an external additive, wherein the external additive includes one or more of metal-polymers, and the general formula of the metal-polymer is as follows: Among them, M is one of Cu, Sn, Zn, Pd, Au, Ag, and Cd, R1 is a H atom, and R2 is an alkyl group having 1 to 12 carbon atoms.

2. The toner according to claim 1, characterized in that The relative molecular weight of the external additive is between 15000 and 20000, preferably between 15000 and 18000, and more preferably between 16000 and 18000.

3. The toner according to claim 1, characterized in that The content of the external additive is 1% to 3% by mass relative to the colored resin particles.

4. The toner according to claim 1, characterized in that The binder resin comprises polyester resin, styrene acrylic resin or a combination of the two. Preferably, the binder resin is polyester resin.

5. The toner according to claim 4, characterized in that The polyester resin is a reaction product of an alcohol compound and a carboxylic acid compound, wherein the alcohol compound comprises one or more combinations of bisphenol A ethylene oxide adduct, butanediol, and diols having 6 to 12 carbon atoms, and the carboxylic acid compound comprises one or more combinations of aromatic diacids such as phthalic acid, isophthalic acid, terephthalic acid, tert-butylisophthalic acid, 2,6-naphthalene dicarboxylic acid, and 4,4'-biphenyl dicarboxylic acid and / or one or more combinations of aliphatic diacids such as succinic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, and citraconic acid.

6. The toner according to claim 5, characterized in that The alcohol compounds include thiol compounds, and the thiol compounds can be selected from one or more combinations of benzenedithiol, dithiols with branches or containing branches having 5 to 10 carbon atoms, and the molar ratio of the thiol compounds to the alcohol compounds is between 0.05 and 0.

2.

7. A method for preparing a toner, characterized in that: The method comprises a step of preparing an external additive, a step of preparing colored resin particles, and a step of preparing a toner by using the external additive and the colored resin particles; The preparation of the metal-polymer external additive comprises the following steps: styrene, acrylate compounds, acrylic acid, 1-dodecanol, 2,2'-azobis(2-methylpropionitrile) and 2,2'-azobis(2-methylbutyronitrile) are mixed and stirred evenly, then dissolved in toluene at 70 to 100° C., stirred within the temperature range for 10 to 25 hours, then added with excess methanol, separated and precipitated, and dried to obtain a polymer, then the polymer and metal nanoparticles are ground until a uniform fine powder is obtained, and then transferred to a ball mill for ball milling for 10 to 24 hours to obtain the metal-polymer external additive; The preparation of the colored resin particles comprises the following steps: adding a carboxylic acid compound, an alcohol compound and a catalyst into a reaction container, stirring at 70-150° C. for 5-8 hours under nitrogen protection to obtain a polyester resin, dispersing the polyester resin with a homogenizer for 3-5 minutes, adding an aqueous solvent, controlling the solid content to 10-18%, obtaining a resin emulsion through an oxidation reaction, adding a dispersed colorant and a release agent to the resin emulsion, adjusting the pH to 5.5-7 under the action of a polymerization initiator, slowly heating to 70-85° C., maintaining for 1-2 hours, then cooling to 50-65° C., maintaining for 2-3 hours, and cooling to room temperature to obtain colored resin particles; The toner preparation comprises adding an external additive to the above-mentioned colored resin particles to prepare the toner.

8. The method for preparing a toner according to claim 7, characterized in that: The catalyst comprises one or more combinations of titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, dibutyltin dichloride, dibutyltin oxide, and diphenyltin oxide, and the catalyst accounts for 0.1% to 0.5% of the total material mass ratio.

9. The method for preparing a toner according to claim 7, characterized in that: The colorant comprises one of black pigment, yellow pigment, red pigment and blue pigment; the release agent comprises one or more combinations of ester wax, carnauba wax, rice bran wax, candelilla wax, wood wax, jojoba oil, beeswax, montan wax, ozokerite, white ceresin, solid paraffin, microcrystalline wax and Fischer-Tropsch wax.

10. The method for preparing a toner according to claim 7, characterized in that: The toner has an average particle size between 6.7 and 7.1 μm, a particle size dispersion between 1.18 and 1.26, and a sphericity between 0.97 and 0.99.

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