Toner, image forming apparatus, image forming method, and method for manufacturing printed materials

Abstract

To provide a toner that is excellent in crushability, low temperature fixability, and heat-resistant storage property.SOLUTION: A toner contains an amorphous polyester resin, a crystalline polyester resin, hydrocarbon wax, and aromatic petroleum resin. The mass ratio of the aromatic petroleum resin to the hydrocarbon wax is 1.0 or more. The amorphous polyester resin contains at least an alkylene oxide adduct of bisphenol A and ethylene glycol as diol components.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a toner, an image forming apparatus, an image forming method, and a method for manufacturing a printed matter.

Background Art

[0002] In recent years, toners are required to have excellent pulverizability in consideration of environmental aspects. In order to improve pulverizability, not only the manufacturing process but also the materials need to be improved. In addition to conventional energy savings, improving low-temperature fixing performance is important from the perspective of suppressing volatile components from fine particles. In particular, it is also necessary to ensure heat-resistant storage stability and durability in actual machines.

[0003] Furthermore, in recent years, electrophotographic systems are used in a wide range of applications from office use to high-volume printing. In particular, when performing double-sided continuous printing, it is also necessary to suppress the risk of blocking due to high temperature after paper ejection.

[0004] For example, Patent Documents 1 to 3 disclose techniques that achieve both pulverizability and low-temperature fixing performance by controlling the thermal properties of the binder resin while using a low-molecular-weight thermoplastic resin. Patent Document 4 discloses a technique that achieves both low-temperature fixing performance and heat-resistant storage stability by using a hydrogenated petroleum resin. Furthermore, Patent Document 5 discloses a technique that achieves both low-temperature fixing performance and heat-resistant storage stability by using a core-shell toner.

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, there is no conventional toner that has all of pulverizability, low-temperature fixing performance, and heat-resistant storage stability.

[0006] An object of the present invention is to provide a toner having excellent pulverizability, low-temperature fixing performance, and heat-resistant storage stability.

Means for Solving the Problems

[0007] To solve the above-mentioned problems, one aspect of the present invention relates to amorphous polyester resin, crystalline polyester resin, hydrocarbon wax, and Resin synthesized using styrene as a raw material Contains 、 The hydrocarbon wax Resin synthesized using styrene as a raw material The mass ratio of is 1.0 or more, and the amorphous polyester resin is a diol component Bi This toner contains an alkylene oxide adduct of sphenol A and ethylene glycol. [Effects of the Invention]

[0008] According to one aspect of the present invention, a toner with excellent pulverizability, low-temperature fixability, and heat-resistant storage properties can be provided. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing an example of an image forming apparatus. [Figure 2] This is a schematic diagram showing another example of an image forming apparatus. [Figure 3] This is a schematic diagram showing another example of an image forming apparatus. [Modes for carrying out the invention]

[0010] The embodiments of the present invention will be described below.

[0011] <Toner> The toner according to this embodiment contains at least an amorphous polyester resin, a crystalline polyester resin, a hydrocarbon wax, and an aromatic petroleum resin.

[0012] <<Amorphous polyester resin>> The amorphous polyester resin used in the toner of this disclosure contains a bisphenol A alkylene oxide adduct and ethylene glycol as diol components. In this specification, diol includes aliphatic diols, alicyclic diols, and aromatic diols. The bisphenol A alkylene oxide adduct is obtained by polymerization of bisphenol A with an alkylene oxide, which is a cyclic ether.

[0013] The content of amorphous polyester resin in the toner is not particularly limited, but is preferably 65% ​​by mass or more and 90% by mass, more preferably 70% by mass or more and 85% by mass, and even more preferably 75% by mass or more and 80% by mass.

[0014] Furthermore, the content of the diol component in the amorphous polyester resin is not particularly limited, but is preferably 35% by mass or more and 65% by mass, more preferably 40% by mass or more and 60% by mass, and even more preferably 45% by mass or more and 55% by mass.

[0015] Furthermore, while the content of the bisphenol A alkylene oxide adduct and ethylene glycol in the diol component is not particularly limited, the mass ratio of the bisphenol A alkylene oxide adduct to ethylene glycol in the diol component is preferably 0.7 to 2.3, more preferably 1 to 2, and even more preferably 1.3 to 1.7.

[0016] The inclusion of a bisphenol A alkylene oxide adduct in the diol component constituting the amorphous polyester resin ensures good heat resistance as a toner. Furthermore, the inclusion of ethylene glycol in the diol component maintains good dispersibility with hydrocarbon waxes. As a result, the toner of this disclosure exhibits excellent pulverability, low-temperature fixability, and heat-resistant storage properties.

[0017] The alkylene oxide adduct of bisphenol A contained as a diol component in the amorphous polyester resin is preferably at least one of the ethylene oxide adduct and the propylene oxide adduct of bisphenol A, more preferably the ethylene oxide adduct and the propylene oxide adduct of bisphenol A.

[0018] When the alkylene oxide adduct of bisphenol A is the ethylene oxide adduct and the propylene oxide adduct of bisphenol A, the mass ratio of the ethylene oxide adduct and the propylene oxide adduct of bisphenol A is not particularly limited, but the mass ratio of the ethylene oxide adduct of bisphenol A to the propylene oxide adduct of bisphenol A in the diol component is preferably 3 to 7, more preferably 4 to 6, and still more preferably 4.5 to 5.5.

[0019] When the diol component of the amorphous polyester resin is at least one of the ethylene oxide adduct and the propylene oxide adduct of bisphenol A, the pulverizability, low-temperature fixing property, and heat-resistant storage property can be improved.

[0020] The amorphous polyester resin used in the toner of the present disclosure may contain other diol components other than the alkylene oxide of bisphenol A and ethylene glycol.

[0021] Examples of other diol components include propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, cyclohexanediyl, bisphenol A, hydrogenated bisphenol A, and the like.

[0022] As a means of crosslinking an amorphous polyester resin, a polyol having a valence of 3 or more may be used in combination. Examples of the polyol having a valence of 3 or more include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, and the like.

[0023] Examples of the acid component constituting the amorphous polyester include benzenedicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid or their anhydrides, alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid or their anhydrides, unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, and mesaconic acid, unsaturated dibasic acid anhydrides such as maleic anhydride, citraconic anhydride, itaconic anhydride, and alkenyl succinic anhydride, and the like.

[0024] In addition, examples of the polyvalent carboxylic acid component having a valence of 3 or more include trimellitic acid, pyromellitic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, tetra(methylenecarboxy)methane, 1,2,7,8-octanetetracarboxylic acid, Empol trimer acid, or their anhydrides, partial lower alkyl esters, and the like.

[0025] The acid value of the amorphous polyester is preferably 0.1 mg KOH / g or more and 100 mg KOH / g or less, more preferably 0.1 mg KOH / g or more and 70 mg KOH / g or less, and even more preferably 0.1 mg KOH / g or more and 50 mg KOH / g or less. When the acid value of the amorphous polyester is 0.1 mg KOH / g or more and 100 mg KOH / g or less, the amorphous polyester can function as a binder resin.

[0026] In the toner of this disclosure, the molecular weight distribution of the amorphous polyester is measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as the solvent. <<Crystalline polyester resin>> The toner of this disclosure contains a crystalline polyester resin. A toner containing a crystalline polyester resin can ensure good low-temperature fixation.

[0027] The melting point of the crystalline polyester resin used in the toner of this disclosure is preferably 90 to 130°C, more preferably 95°C to 125°C, and even more preferably 100 to 120°C.

[0028] In crystalline polyesters, there are non-crystallized regions, and their glass transition temperature increases with the melting point. Furthermore, the closer the glass transition temperature of the non-crystallized region is to that of the amorphous polyester resin, the higher the compatibility and the better the low-temperature fixability. For these reasons, a melting point of crystalline polyester resin of 90°C or higher is preferable because it results in better low-temperature fixability.

[0029] However, if the melting point of the crystalline polyester resin is too high, the heat required for fixing may not melt it sufficiently, potentially hindering its low-temperature fixing properties. For these reasons, it is preferable for the melting point of the crystalline polyester resin to be 120°C or lower, as this suppresses a decrease in low-temperature fixing properties.

[0030] Crystalline polyester resins can be produced by polycondensation reaction of (I) a polycarboxylic acid component consisting of a linear unsaturated aliphatic dicarboxylic acid or its reactive derivative (e.g., acid anhydrides, lower alkyl esters having 1 to 4 carbon atoms, acid halides, etc.) and (II) a polyhydric alcohol component consisting of a linear aliphatic diol, using conventional methods.

[0031] In the production of crystalline polyester resins, small amounts of other polycarboxylic acids may be added to the polycarboxylic acid component as needed. In this case, polycarboxylic acids include (i) branched unsaturated aliphatic dicarboxylic acids, (ii) saturated aliphatic polycarboxylic acids such as saturated aliphatic dicarboxylic acids and saturated aliphatic tricarboxylic acids, and (iii) aromatic polycarboxylic acids such as aromatic dicarboxylic acids and aromatic tricarboxylic acids.

[0032] The amount of these polycarboxylic acids added is usually 30 mol% or less, preferably 20 mol% or less, and more preferably 10 mol% or less, relative to the total carboxylic acid, and is added as appropriate within the range in which the resulting polyester has crystalline properties.

[0033] Examples of polycarboxylic acids that can be added as needed include dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, citraconic acid, phthalic acid, isophthalic acid, and terephthalic acid; and trivalent or higher polycarboxylic acids such as trimetic anhydride, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalentricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, and 1,2,7,8-octanetetracarboxylic acid.

[0034] The polyhydric alcohol component may include small amounts of aliphatic branched-chain dihydric alcohols or cyclic dihydric alcohols, as well as trihydric or higher polyhydric alcohols, as needed. The amount added is 30 mol% or less, preferably 20 mol% or less, and more preferably 10 mol% or less, relative to the total alcohol, and is added appropriately within the range in which the resulting polyester has crystalline properties.

[0035] Examples of polyhydric alcohols that may be added as needed include 1,4-bis(hydroxymethyl)cyclohexane, polyethylene glycol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, and glycerin.

[0036] In crystalline polyester resins, a sharp molecular weight distribution is preferable from the viewpoint of low-temperature fixability, and a relatively low molecular weight is also preferable. The molecular weight of the crystalline polyester resin is preferably such that, in the molecular weight distribution of its o-dichlorobenzene-soluble component determined by GPC, its weight-average molecular weight (Mw) is 5500 to 6500, its number-average molecular weight (Mn) is 1300 to 1500, and its Mw / Mn ratio is 2 to 5.

[0037] The molecular weight distribution of a crystalline polyester resin is based on a molecular weight distribution diagram with logM (where M is the molecular weight) on the x-axis and mass% on the y-axis. In the case of the crystalline polyester resin (A) used in the toner of this disclosure, it is preferable that the molecular weight peak is in the range of 3.5 to 4.0 mass% in this molecular weight distribution diagram, and that the full width at half maximum of that peak is 1.5 or less.

[0038] <<Hydroxide-based wax>> The toner of this disclosure contains a hydrocarbon wax. Because hydrocarbon waxes have a relatively high melting point, toners containing hydrocarbon waxes have excellent heat resistance and excellent blocking suppression properties.

[0039] The hydrocarbon wax may be either a synthetic wax or a natural wax. Examples of hydrocarbon waxes include paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax, and polypropylene wax. Among these, Fischer-Tropsch wax is preferred for improving the heat resistance and blocking resistance of the toner.

[0040] The melting point of the hydrocarbon wax is not particularly limited, but it is preferably between 75°C and 100°C, and more preferably between 80°C and 95°C. Setting the melting point of the hydrocarbon wax to 75°C or higher ensures the effect of suppressing blocking in the toner. Furthermore, setting the melting point of the hydrocarbon wax to 100°C or lower suppresses the inhibition of low-temperature fixing performance in the toner.

[0041] The hydrocarbon wax content in the toner is preferably 4.5% by mass or more and 6.5% by mass or less, and more preferably 5% by mass or more and 6% by mass or less. By setting the hydrocarbon wax content to 4.5% by mass or more, release properties during fixing in the toner can be ensured. Furthermore, by setting the hydrocarbon wax content to 6.5% by mass or less, a decrease in toner durability due to excessive wax can be suppressed.

[0042] <<Aromatic petroleum resin>> The toner disclosed herein contains an aromatic petroleum resin. Toner containing an aromatic petroleum resin makes it possible to improve pulverability and enhance heat resistance while maintaining low-temperature fixability.

[0043] In this specification, aromatic petroleum resins refer to resins synthesized using styrene, vinyltoluene, indene, and other C9 fractions of petroleum as raw materials. Among these aromatic petroleum resins, styrene copolymers are preferred in terms of improving wax dispersibility and toner durability.

[0044] The styrene copolymer is not particularly limited, but examples include polymers of styrene and its substituted products such as polystyrene, poly-p-styrene, and polyvinyltoluene; styrene-α-methylstyrene copolymer, styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, and styrene-maleic acid ester copolymer. Among these, styrene-α-methylstyrene copolymer is preferred.

[0045] The glass transition temperature (Tg) of the styrene copolymer is preferably 60°C or higher, and more preferably 65 to 85°C. A Tg of 60°C or higher for the styrene resin improves its heat resistance and storage properties.

[0046] The Tg is measured using a differential scanning calorimeter (TA Instruments, Q-200). Specifically, approximately 5.0 mg of the target sample is placed in an aluminum sample container, the sample container is placed on a holder unit, and then set in an electric furnace. Next, under a nitrogen atmosphere, the temperature is increased from -80°C to 150°C at a heating rate of 10°C / min. The glass transition temperature (Tg) of the target sample is then determined from the resulting DSC curve using an analysis program in the differential scanning calorimeter.

[0047] In the toner of this disclosure, it is preferable that the mass ratio of aromatic petroleum resin to hydrocarbon wax is 1.0 or higher. By having a ratio of 1.0 or higher, good wax dispersibility can be maintained and the durability of the toner can be ensured.

[0048] The weight-average molecular weight of the aromatic petroleum resin is preferably between 1000 and 4000, more preferably between 1300 and 3800, and even more preferably between 1500 and 3700. A weight-average molecular weight of 1000 or more ensures the durability of the toner in actual use. Furthermore, a weight-average molecular weight of 4000 or less ensures good pulverability in the toner.

[0049] The toners of this disclosure may optionally contain colorants, charge control agents, and external additives.

[0050] <<Coloring agent>> All known dyes and pigments can be used as colorants in the toner of this disclosure.

[0051] Examples of colorants include carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, yellow ochre, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, anthrazan yellow BGL, isoindolinone yellow, red iron oxide, red lead, red lead, ka Dominum Red, Cadmium Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Faise Red, Parachlor-Orthonitroaniline Red, Risol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Bordeaux -5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinon Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkali Blue Lake, Peacock Blue Lake, Victoria Blue -Ki, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC), indigo, ultramarine, navy blue, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B, naphthol green B, green gold, acid green lake, malachite green lake, phthalocyanine green,Examples include anthraquinone green, titanium dioxide, zinc oxide, lithobone, and mixtures thereof.

[0052] The colorant content is preferably 1% by mass or more and 15% by mass or less relative to the toner, and more preferably 3% by mass or more and 10% by mass or less.

[0053] The colorant used in the toner of this disclosure can also be used as a masterbatch compounded with a resin. The same amorphous polyester used as the binder resin described above can be used as the binder resin kneaded together with the masterbatch. Furthermore, the binder resin may be used alone or as a mixture of two or more types.

[0054] A masterbatch can be obtained by mixing and kneading a resin and a colorant for masterbatch preparation under high shear force. In this process, an organic solvent can be used to enhance the interaction between the colorant and the resin. Another method, known as the flushing method, involves mixing and kneading an aqueous paste containing water from the colorant with the resin and an organic solvent to transfer the colorant to the resin side and remove the water and organic solvent components. This method is also suitable because it allows the use of a wet cake of colorant as is, eliminating the need for drying.

[0055] For mixing and kneading, a high-shear dispersion device such as a three-roll mill is preferably used. The amount of masterbatch used is preferably 0.1 to 20 parts by mass per 100 parts by mass of binder resin.

[0056] Furthermore, the resin used for masterbatch preparation preferably has an acid value of 30 mg KOH / g or less and an amine value of 1 to 100, and is used with a dispersed coloring agent; more preferably has an acid value of 20 mg KOH / g or less and an amine value of 10 to 50, and is used with a dispersed coloring agent.

[0057] If the acid value exceeds 30 mgKOH / g, the electrostatic properties under high humidity will decrease, and pigment dispersibility may also become insufficient. Furthermore, if the amine value is less than 1, or if it exceeds 100, pigment dispersibility may also become insufficient. The acid value can be measured according to the method described in JIS K0070, and the amine value can be measured according to the method described in JIS K7237.

[0058] Furthermore, dispersants can be used to improve the dispersibility of the pigment. The dispersant is preferably highly compatible with the binder resin in terms of pigment dispersibility. Specific commercially available examples include "Azisper (registered trademark) PB821," "Azisper PB822" (manufactured by Ajinomoto Fine Techno Co., Ltd.), "Disperbyk (registered trademark)-2001" (manufactured by Bic Chemie Co., Ltd.), and "EFKA-4010" (manufactured by EFKA Corporation).

[0059] The mass-average molecular weight of the dispersant is the molecular weight of the maximum value of the main peak in styrene-represented mass in GPC, preferably 500 to 100,000, more preferably 3,000 to 100,000, even more preferably 5,000 to 50,000, and particularly preferably 5,000 to 30,000 from the viewpoint of pigment dispersibility.

[0060] If the mass-average molecular weight of the dispersant is less than 500, its polarity may increase, potentially reducing the dispersibility of the colorant. Conversely, if the mass-average molecular weight of the dispersant exceeds 100,000, its affinity for the solvent may increase, potentially reducing the dispersibility of the colorant.

[0061] The dispersant is preferably added to the toner in a proportion of 0.1% by mass or more and 10% by mass or less relative to the colorant. If the proportion of the dispersant is less than 0.1% by mass, the pigment dispersibility may be insufficient, and if it is more than 10% by mass, the electrostatic properties under high humidity may decrease.

[0062] <<Static Control Agent>> All known charge control agents can be used in the toners of this disclosure. However, for color toners, white or light-colored charge control agents are preferred. If a colored charge control agent is used, the color will mix with the toner and cause dullness, so the amount contained must be reduced.

[0063] Examples of charge control agents include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, elemental or compound phosphorus, elemental or compound tungsten, fluorine-based surfactants, metal salicylic acid salts, and metal salts of salicylic acid derivatives.

[0064] Specifically, the charge control agents include Bontron 03 (a nigrosine-based dye), Bontron P-51 (a quaternary ammonium salt), Bontron S-34 (a metal-containing azo dye), E-82 (an oxynaphthoic acid-based metal complex), E-84 (a salicylic acid-based metal complex), and E-89 (a phenolic condensate) (all manufactured by Orient Chemical Industry Co., Ltd.), TP-302 and TP-415 (quaternary ammonium salt molybdenum complexes) (both manufactured by Hodogaya Chemical Co., Ltd.), Copy Charge PSY VP2038 (a quaternary ammonium salt), Copy Blue PR (a triphenylmethane derivative), Copy Charge NEG VP2036 (a quaternary ammonium salt), and Copy Charge NX Examples include VP434 (manufactured by Hoechst), LRA-901, the boron complex LR-147 (manufactured by Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone, azo pigments, and other polymer compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.

[0065] The content of the charge control agent in the toner of this disclosure is determined by the type of binder resin, the presence or absence of additives used as needed, and the toner manufacturing method including the dispersion method, and is not uniquely limited, but is preferably used in the range of 0.1 to 10% by mass, and more preferably in the range of 0.2 to 5% by mass, based on 100% by mass of the binder resin.

[0066] If the content of the electrostatic control agent exceeds 10% by mass, the toner becomes too electrostatic, reducing the effectiveness of the electrostatic control agent, increasing the electrostatic attraction force with the developing roller, leading to decreased fluidity of the developer and a decrease in image density. These electrostatic control agents and release agents can be melt-mixed together with the masterbatch and resin.

[0067] <<External Additives>> Furthermore, to improve the fluidity, storage, developability, transferability, and durability of the toner, inorganic fine particles such as oxide fine particles and hydrophobic silica fine powder, or polymer-based resin fine particles may be added and mixed as external additives to the toner matrix particles. This effect is achieved by covering the wax that reduces transferability and durability with these external additives and by reducing the contact area due to the toner surface being covered with fine particles.

[0068] These inorganic fine particles preferably have a hydrophobic surface treatment, and hydrophobic treated metal oxide fine particles such as silica or titanium dioxide are preferably used. By increasing the amount of hydrophobic treated titanium dioxide added compared to the amount of hydrophobic treated silica added, excellent stability of charge with respect to humidity can be achieved, resulting in a toner with improved toner transfer rate and good filming resistance.

[0069] The primary particle size of inorganic or resin microparticles is preferably 5 nm to 2 μm. The proportion of inorganic microparticles used varies depending on the type, but is typically in the range of 0.01 to 5 mass% relative to the toner particles. Here, the primary particle size refers to the average value of the volume-average primary particle size (average primary particle size based on the number of particles) obtained from transmission electron microscope images (TEM images) or scanning electron microscope images (SEM images) of the particles.

[0070] Specific examples of inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. These inorganic fine particles can be used individually or in combination of two or more types.

[0071] Furthermore, polymer-based resin fine particles include, for example, polymer particles made from polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, or dispersion polymerization, as well as polymer particles made from polycondensation systems such as methacrylate esters and acrylic ester copolymers, silicones, benzoguanamine, and nylon, and thermosetting resins.

[0072] Of these, when glycerin fatty acid esters or polyglycerin fatty acid esters are used in combination with ketone waxes as release agents, it is preferable to use silica and titanium dioxide in combination. Silica and titanium dioxide have strong negative charge properties and can change positively charged particles to negatively charged particles without the use of external additives.

[0073] Representative examples of hydrophobic agents used to hydrophobize the surface of inorganic fine particles include dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, allyldimethyldichlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, brommethyldimethylchlorosilane, α-chloroethyltrichlorosilane, p-chloroethyltrichlorosilane, chlormethyldimethylchlorosilane, chlormethyltrichlorosilane, and p-chlorophenyltrichlorosilane. Silane, 3-chloropropyltrichlorosilane, 3-chloropropyltrimethoxysilane, vinyltriethoxysilane, vinylmethoxysilane, vinyl-tris(β-methoxyethoxy)silane, γ-methacrylateoxypropyltrimethoxysilane, vinyltriacetoxysilane, divinyldichlorosilane, dimethylvinylchlorosilane, octyl-trichlorosilane, decyl-trichlorosilane, nonyl-trichlorosilane, (4-t-propylphenyl)-trichlorosilane Lan, (4-t-butylphenyl)-trichlorosilane, dipentyl-dichlorosilane, dihexyl-dichlorosilane, dioctyl-dichlorosilane, dinonyl-dichlorosilane, didecyl-dichlorosilane, didodecyl-dichlorosilane, dihexadecyl-dichlorosilane, (4-t-butylphenyl)-octyl-dichlorosilane, dioctyl-dichlorosilane, didecenyl-dichlorosilane, dinonenyl-dichlorosilane, di-2-ethylhexyl-dichlorosilane, Examples include di-3,3-dimethylpentyl-dichlorosilane, trihexyl-chlorosilane, trioctyl-chlorosilane, tridecyl-chlorosilane, dioctyl-methyl-chlorosilane, octyl-dimethyl-chlorosilane, (4-t-propylphenyl)-diethyl-chlorosilane, octyltrimethoxysilane, hexamethyldisilazane, hexaethyldisilazane, diethyltetramethyldisilazane, hexaphenyldisilazane, and hexatolyldisilazane. Other typical examples of hydrophobic treatment agents include titanate-based coupling agents and aluminum-based coupling agents.

[0074] For mixing the above external additives, a general powder mixer is used, but it is preferable to equip it with a jacket or the like to regulate the internal temperature. For example, a V-type mixer, rocking mixer, Lödige mixer, Nauter mixer, Henschel mixer, etc., are preferably used.

[0075] The inorganic and resin microparticles mentioned above, when incorporated into the toner (internal addition), improve transferability and durability, although their effect is reduced compared to external addition. They also improve the toner's pulverizability. Furthermore, using both external and internal addition suppresses the embedding of externally added microparticles, resulting in consistently excellent transferability and improved durability in the toner.

[0076] <<Other ingredients>> Furthermore, the toner of this disclosure may contain other components as appropriate, depending on the purpose. Examples of other components include fluidity enhancers, cleaning agents, magnetic materials, and metal soaps.

[0077] Fluidity improvers are those that enhance hydrophobicity through surface treatment, preventing deterioration of flow and electrostatic properties even under high humidity conditions. Examples of fluidity improvers include silane coupling agents, silylation agents, silane coupling agents containing alkyl fluoride, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils.

[0078] Cleaning enhancers are added to toner to remove residual post-transfer developer from the electrostatic latent image carrier and intermediate transfer media.

[0079] Examples of cleaning agents include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, polymer microparticles produced by soap-free emulsion polymerization such as polymethyl methacrylate microparticles and polystyrene microparticles. The polymer microparticles are preferably those with a relatively narrow particle size distribution, and those with a weight-average particle size of 0.01 to 1 μm are preferred.

[0080] There are no particular restrictions on the magnetic material; it can be appropriately selected from known materials depending on the purpose, such as iron powder, magnetite, and ferrite. Among these, white magnetic materials are preferred in terms of color.

[0081] There are no particular restrictions on the metal soap used; it can be appropriately selected depending on the purpose. Examples include zinc stearate.

[0082] <<Toner manufacturing method>> The methods for manufacturing the toner of this disclosure are not particularly limited, and it can be manufactured by a melt-kneading-and-grinding method and polymerization method, a polyaddition reaction method using an isocyanate group-containing prepolymer, a method of dissolving in a solvent, desolventing and grinding, as well as by a melt-spray method.

[0083] Examples of toner manufacturing methods include melt kneading, polymerization methods (suspension polymerization / emulsion polymerization) in which monomer compositions containing specific crystalline polymers and polymerizable monomers are directly polymerized in an aqueous phase, polyaddition reaction methods in which compositions containing specific crystalline polymers and isocyanate group-containing prepolymers are directly extended / crosslinked with amines in an aqueous phase, and methods of solvent dissolution, solvent removal, and pulverization.

[0084] As mentioned above, in the toner of this disclosure, a binder resin whose main component is polyester resin is preferably used.

[0085] In the melt-mixing and grinding method, suitable equipment for melt-mixing the toner includes batch-type two-roll mixers, Banbury mixers, continuous twin-screw extruders (for example, the KTK twin-screw extruder manufactured by Kobe Steel, Ltd., the TEM twin-screw extruder manufactured by Toshiba Machine Co., Ltd., the twin-screw extruder manufactured by KCK Corporation, the PCM twin-screw extruder manufactured by Ikegai Iron Works Co., Ltd., and the KEX twin-screw extruder manufactured by Kurimoto Iron Works Co., Ltd.), and continuous single-screw kneaders (for example, the Co-Kneader manufactured by Buss Co., Ltd.).

[0086] In the polymerization method described above, and in the polyaddition reaction method using isocyanate group-containing prepolymers, it is essential to forcibly emulsify (form droplets) by applying mechanical energy in the aqueous phase. Means of applying such mechanical energy include strong stirring methods such as homomixers, ultrasonic devices, and Manton-Gorin devices, or methods of applying ultrasonic vibration energy.

[0087] Regarding the grinding method, coarse grinding can be performed using a hammer mill or Rotoplex, followed by the use of a jet-stream-based fine grinder or a mechanical fine grinder, with the goal of achieving an average particle size of 3 to 15 μm. Furthermore, the ground material is size-adjusted to 5 to 20 μm using an air-powered classifier or similar device.

[0088] The softening temperature (T) determined by the toner flow tester 1 / 2 The temperature at which half of the sample flows out under increased temperature and a predetermined load is preferably 115 to 140°C. Furthermore, from the viewpoint of toner storage, the glass transition temperature (Tg) is preferably 55 to 70°C, and more preferably 57 to 70°C.

[0089] If the Tg is lower than 55°C, the toner is more prone to degradation in high-temperature environments, and offset may occur during fixing. Furthermore, if the Tg exceeds 70°C, fixing performance may decrease.

[0090] External additives are added to the toner base by mixing and stirring the toner base and the external additive using a mixer, which breaks down the external additive and coats the toner surface. At this time, it is important for durability that the external additive, such as inorganic fine particles or resin fine particles, adheres uniformly and firmly to the toner base.

[0091] <<Developer>> The developer using the toner of this disclosure may be either a one-component developer or a two-component developer. For example, a two-component developer comprises the toner of this disclosure and a carrier.

[0092] There are no particular restrictions on the carrier, and it can be appropriately selected according to the purpose, but one having a core material and a resin layer covering the core material is preferred.

[0093] There are no particular restrictions on the core material, and it can be appropriately selected according to the purpose. For example, manganese-strontium (Mn-Sr) materials with a magnetization of 50 emu / g to 90 emu / g and manganese-magnesium (Mn-Mg) materials are preferred. In terms of ensuring image density, highly magnetized materials such as iron powder (100 emu / g or more) and magnetite (75 emu / g to 120 emu / g) are preferred.

[0094] Furthermore, weakly magnetized materials such as copper-zinc (Cu-Zn) based materials (30 emu / g to 80 emu / g) are preferred because they allow for weaker contact with the photoreceptor when the toner is in a puff-like state, which is advantageous for improving image quality. These weakly magnetized materials may be used individually or in combination of two or more types.

[0095] The volume-average particle size of the core material is preferably 25 μm or more and 200 μm or less.

[0096] There are no particular restrictions on the material of the resin layer, and it can be appropriately selected according to the purpose. Examples include amino resins, polyvinyl resins, polystyrene resins, halogenated olefin resins, polyester resins, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoropropylene resins, copolymers of vinylidene fluoride and acrylic monomers, copolymers of vinylidene fluoride and vinyl fluoride, fluoropolymers such as terpolymers of tetrafluoroethylene, vinylidene fluoride and non-fluorinated monomers, and silicone resins. These may be used individually or in combination of two or more.

[0097] In a two-component developer, the mixing ratio of toner to carrier is preferably such that the amount of toner relative to the carrier is 2.0% by mass or more and 12.0% by mass or less, and more preferably 2.5% by mass or more and 10.0% by mass or less.

[0098] <<Toner Storage Unit>> The toner of this disclosure can be used by storing it in a toner storage unit. Here, a toner storage unit is a unit having the function of storing toner, in which toner is stored. Examples of the toner storage unit include a toner storage container, a developer, a process cartridge, and the like.

[0099] A toner container refers to a container that holds toner.

[0100] A developing unit refers to a device that has the means to store and develop toner.

[0101] A process cartridge refers to a device that integrates at least an image carrier and a developing means, contains toner, and is detachable from an image forming apparatus. The process cartridge may further include at least one selected from a charging means, an exposure means, and a cleaning means.

[0102] The toner storage unit is mounted in an image forming apparatus described later, and image formation is performed using the toner of this disclosure. As a result, it exhibits excellent low-temperature fixing properties and heat resistance for storage, and excellent images can be obtained.

[0103] <<Process Cartridge>> The toner of this disclosure is used in a process cartridge. The process cartridge comprises at least an electrostatic latent image carrier that carries an electrostatic latent image, and a developing means that develops the electrostatic latent image carried on the electrostatic latent image carrier using toner to form a visible image, and further comprises other means such as a charging means, an exposure means, a developing means, a transfer means, a cleaning means, a static elimination means, etc., as appropriately selected as necessary.

[0104] The developing means comprises at least a developer container for containing the toner of the present disclosure or the developer described above, and a developer carrier for carrying and transporting the toner or developer contained in the developer container, and may further include a layer thickness regulating member for regulating the thickness of the toner layer to be carried.

[0105] The process cartridge can be detachably mounted in various electrophotographic devices, facsimile machines, and printers, and is preferably detachably mounted in the image forming apparatus of the present disclosure described later.

[0106] <Image forming method and image forming apparatus> The image forming method of the present disclosure includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier; a developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier using pulverized toner to form a pulverized toner image; a transfer step of transferring the pulverized toner image formed on the electrostatic latent image carrier to the surface of a recording medium; and a fixing step of fixing the pulverized toner image transferred to the surface of the recording medium.

[0107] The image forming method disclosed herein may further include, as necessary, other steps such as a static elimination step, a cleaning step, a recycling step, and a control step.

[0108] The image forming apparatus of the present disclosure includes an electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, a developing unit that forms a pulverized toner image by developing the electrostatic latent image formed on the electrostatic latent image carrier using pulverized toner, a transfer unit that transfers the pulverized toner image formed on the electrostatic latent image carrier to the surface of a recording medium, and a fixing unit that fixes the pulverized toner image transferred to the surface of the recording medium, and further includes other units such as an anti-static unit, a cleaning unit, a recycling unit, and a control unit as needed.

[0109] In the image forming method and image forming apparatus of this disclosure, the crushed toner used is the toner of this disclosure.

[0110] Furthermore, the method for manufacturing printed materials of this disclosure involves using the image forming apparatus of this disclosure to form a pulverized toner image on a recording medium using the toner of this disclosure.

[0111] According to the method for manufacturing printed materials of the present invention, since the toner of this disclosure, which has excellent pulverability, low-temperature fixability, and heat-resistant storage properties, is used, printed materials with high-quality images can be obtained over a long period of time.

[0112] <<Electrostatic latent image formation process and electrostatic latent image formation unit>> The electrostatic latent image formation step, which constitutes the image forming method of this disclosure, is a step of forming an electrostatic latent image on an electrostatic latent image carrier. There are no particular restrictions on the material, shape, structure, size, etc., of the electrostatic latent image carrier (hereinafter sometimes referred to as "electrophotographic photoreceptor" or "photoreceptor"), and it can be appropriately selected from known ones.

[0113] A drum shape is preferred for the electrostatic latent image carrier. Examples of materials for the electrostatic latent image carrier include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors (OPC) such as polysilane and phthalopolymethine. Among these, organic photoreceptors (OPC) are preferred as materials for the electrostatic latent image carrier because they can obtain higher-resolution images.

[0114] The formation of an electrostatic latent image can be performed, for example, by uniformly charging the surface of an electrostatic latent image carrier and then exposing it to an image, and this can be done by an electrostatic latent image forming unit.

[0115] The electrostatic latent image forming unit comprises, for example, at least a charging unit (charger) that uniformly charges the surface of the electrostatic latent image carrier, and an exposure unit (exposure unit) that exposes the surface of the electrostatic latent image carrier to an image-like state.

[0116] Charging can be performed, for example, by applying a voltage to the surface of an electrostatic latent image carrier using a charger. There are no particular restrictions on the charger, and it can be appropriately selected according to the purpose. Examples include contact chargers, which are known themselves, equipped with conductive or semiconducting rolls, brushes, films, rubber blades, etc., and non-contact chargers that utilize corona discharge, such as Corotron and Scorotron.

[0117] Preferably, the charger is positioned in contact with or without contact with the electrostatic latent image carrier, and charges the surface of the electrostatic latent image carrier by superimposing DC and AC voltages. Alternatively, it is preferable that the charger is a charging roller positioned in close proximity to the electrostatic latent image carrier via a gap tape, and charges the surface of the electrostatic latent image carrier by superimposing DC and AC voltages on the charging roller.

[0118] Exposure can be performed, for example, by exposing the surface of the electrostatic latent image carrier to an image using an exposure unit. There are no particular restrictions on the exposure unit, as long as it can expose the surface of the electrostatic latent image carrier, which has been charged by the aforementioned charger, to the desired image; it can be appropriately selected according to the purpose. Examples of exposure units include copying optical systems, rod lens array systems, laser optical systems, and liquid crystal shutter optical systems.

[0119] Furthermore, in the image forming method and image forming apparatus disclosed herein, a back-facing method may be employed in which the electrostatic latent image carrier is exposed in an image-like manner from the back side.

[0120] <<Developing Process and Developing Unit>> The development process is a process of developing an electrostatic latent image using toner to form a visible image. The formation of the visible image can be performed, for example, by developing the electrostatic latent image using the toner of this disclosure, and can be done by a developing unit.

[0121] The developing unit preferably includes, for example, a developer capable of containing the toner of this disclosure and applying the toner to an electrostatic latent image by contact or non-contact, and more preferably a developer equipped with a toner container.

[0122] The developing unit may be a single-color developing unit or a multi-color developing unit. For example, a suitable example is one having an agitator that frictionally agitates and charges the toner, and a rotatable magnetic roller.

[0123] <<Transfer process and transfer unit>> The transfer process is a process of transferring a visible image to a recording medium. Preferably, the transfer process uses an intermediate transfer medium, first transferring the visible image onto the intermediate transfer medium, and then secondarily transferring the visible image onto the recording medium. In the transfer process, two or more toners, preferably full-color toners, are used. More preferably, the transfer process includes a first transfer process in which the visible image is transferred onto the intermediate transfer medium to form a composite transfer image, and a second transfer process in which the composite transfer image is transferred onto the recording medium.

[0124] The transfer section (first transfer section, second transfer section) preferably includes at least a transfer device that exfoliates and charges the visible image formed on the electrostatic latent image carrier (photoreceptor) toward the recording medium. There may be one transfer section or two or more.

[0125] Examples of transfer devices include corona discharge transfer devices, transfer belts, transfer rollers, pressure transfer rollers, and adhesive transfer devices.

[0126] There are no particular restrictions on the recording medium; any publicly known recording medium (recording paper) can be selected as appropriate.

[0127] <<Fixing process and fixing section>> The fixing process is the process of fixing the visible image transferred to the recording medium using a fixing device. The fixing process may be performed for each color developer after the image is transferred to the recording medium, or it may be performed simultaneously for each color developer in a stacked state.

[0128] There are no particular restrictions on the fixing device, and it can be appropriately selected according to the purpose, but known heating and pressing means are preferred. Examples of heating and pressing means include a combination of a heating roller and a pressing roller, and a combination of a heating roller, a pressing roller and an endless belt.

[0129] The static elimination process involves applying a static elimination bias to the electrostatic latent image carrier to remove static electricity, and this process can be more effectively performed by the static elimination unit.

[0130] There are no particular restrictions on the static elimination unit; it just needs to be able to apply a static elimination bias to the electrostatic latent image carrier, and can be appropriately selected from known static eliminators. For example, a static elimination lamp is a suitable example.

[0131] The cleaning process is a process of removing toner remaining on the electrostatic latent image carrier, and can be performed more effectively by the cleaning unit.

[0132] There are no particular restrictions on the cleaning unit; it just needs to be able to remove toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Suitable cleaners include, for example, magnetic brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, and web cleaners.

[0133] The recycling process involves recycling the toner removed in the cleaning process into the developing unit, and can be more effectively performed in the recycling unit. There are no particular restrictions on the recycling unit, and examples include well-known transport units.

[0134] The control process is a process that controls each of the above-mentioned processes, and each process can be preferably performed by the control unit.

[0135] As for the control unit, there are no particular restrictions as long as it can control the movement of each part, and it can be appropriately selected according to the purpose. Examples include sequencers, computers, and other devices.

[0136] Figure 1 is a schematic diagram showing an example (first embodiment) of the image forming apparatus of the present invention. The image forming apparatus 100A comprises a photoreceptor drum 10, a charging roller 20, an exposure device (not shown), a developing device 40, an intermediate transfer belt 50, a cleaning device 60 having a cleaning blade, and a static elimination lamp 70. The photoreceptor drum 10 is an example of an electrostatic latent image carrier.

[0137] The intermediate transfer belt 50 is an endless belt stretched by three rollers 51 located on the inside, and can move in the direction of the arrow in Figure 1. Some of the three rollers 51 also function as transfer bias rollers capable of applying a transfer bias (primary transfer bias) to the intermediate transfer belt 50.

[0138] A cleaning device 90 having a cleaning blade is positioned near the intermediate transfer belt 50. Furthermore, a transfer roller 80 capable of applying a transfer bias (secondary transfer bias) for transferring a toner image onto the transfer paper 95 is positioned opposite the intermediate transfer belt 50.

[0139] A corona charging device 58 is provided around the intermediate transfer belt 50 to impart an electric charge to the toner image transferred to the intermediate transfer belt 50. The corona charging device 58 is positioned between the contact area between the photoreceptor drum 10 and the intermediate transfer belt 50 and the contact area between the intermediate transfer belt 50 and the transfer paper 95, with respect to the rotational direction of the intermediate transfer belt 50 (arrow direction in Figure 1).

[0140] The developing apparatus 40 consists of a developing belt 41 and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C, all of which are located around the developing belt 41.

[0141] Each color developing unit 45 (developing units 45K, 45Y, 45M, 45C) includes a developer storage section 42 (developer storage section 42K, 42Y, 42M, 42C), a developer supply roller 43 (developer supply roller 43K, 43Y, 43M, 43C), and a developing roller (developer carrier) 44 (developing roller 44K, 44Y, 44M, 44C). The developing belt 41 is an endless belt stretched by multiple belt rollers and can move in the direction of the arrow in Figure 1. Furthermore, a portion of the developing belt 41 is in contact with the photoreceptor drum 10.

[0142] Next, a method for forming an image using the image forming apparatus 100A will be described. First, the surface of the photoreceptor drum 10 is uniformly charged using the charging roller 20, and then the photoreceptor drum 10 is exposed to exposure light L using an exposure device (not shown) to form an electrostatic latent image. Next, the electrostatic latent image formed on the photoreceptor drum 10 is developed with toner supplied from the developing device 40 to form a toner image.

[0143] Furthermore, the toner image formed on the photoreceptor drum 10 is transferred to the intermediate transfer belt 50 (primary transfer) by a transfer bias applied from the roller 51, and then transferred to the transfer paper 95 (secondary transfer) by a transfer bias applied from the transfer roller 80. Meanwhile, the photoreceptor drum 10, on which the toner image has been transferred to the intermediate transfer belt 50, is cleaned of any remaining toner on its surface by the cleaning device 60, and then static electricity is removed by the static elimination lamp 70.

[0144] Figure 2 shows another example (second embodiment) of an image forming apparatus used in the present invention. The image forming apparatus 100B has the same configuration as the image forming apparatus 100A, except that it does not have a developing belt 41, and the black developing unit 45K, yellow developing unit 45Y, magenta developing unit 45M, and cyan developing unit 45C are arranged directly opposite each other around the photoreceptor drum 10.

[0145] Figure 3 shows another example (third embodiment) of the image forming apparatus used in the present invention. The image forming apparatus 100C is a tandem-type color image forming apparatus and comprises a copy device body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.

[0146] The intermediate transfer belt 50, located in the center of the copying device body 150, is an endless belt stretched over three rollers 14, 15, and 16, and can move in the direction of the arrow in Figure 3.

[0147] Near the roller 15, a cleaning device 17 is positioned, which has a cleaning blade for removing toner remaining on the intermediate transfer belt 50 on which the toner image has been transferred to the recording paper. Facing the intermediate transfer belt 50 stretched by rollers 14 and 15, and along the transport direction, yellow, cyan, magenta, and black image forming units 120 (image forming units 120Y, 120C, 120M, and 120K) are arranged side by side.

[0148] Furthermore, an exposure device 21 is located near the image forming unit 120. In addition, a secondary transfer device 22 is located on the side of the intermediate transfer belt 50 opposite to the side where the image forming unit 120 is located. The secondary transfer device 22 comprises a pair of rollers 23 and a secondary transfer belt 24.

[0149] The secondary transfer belt 24 is an endless belt stretched over a pair of rollers 23, and the recording paper being transported on the secondary transfer belt 24 and the intermediate transfer belt 50 can come into contact between the rollers 16 and 23.

[0150] Furthermore, a fixing device 25 is positioned near the secondary transfer belt 24, which includes a fixing belt 26, an endless belt stretched over a pair of rollers, and a pressure roller 27 positioned under pressure from the fixing belt 26. A sheet reversing device 28 is also positioned near the secondary transfer belt 24 and the fixing device 25 to reverse the recording paper when forming an image on both sides of the recording paper.

[0151] Next, a method for forming a full-color image using the image forming apparatus 100C will be described. First, a color document is placed on the document tray 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and the color document is placed on the contact glass 32 of the scanner 300, and then the automatic document feeder 400 is closed.

[0152] When the start switch is pressed, if a document is placed in the automatic document transporter 400, the document is transported and moved onto the contact glass 32. Alternatively, if a document is placed on the contact glass 32, the scanner 300 is driven immediately, and the first traveling body 33 equipped with a light source and the second traveling body 34 equipped with a mirror move.

[0153] At this time, the light emitted from the first traveling body 33 is reflected from the document surface by the second traveling body 34, and then received by the reading sensor 36 via the imaging lens 35, thereby reading the document and obtaining image information in black, yellow, magenta, and cyan. The image information for each color is transmitted to the respective image forming means 18 in the respective color image forming unit 120, and toner images of each color are formed.

[0154] Each color image forming unit 120 comprises a photoreceptor drum 10 (photoreceptor drums 10K, 10Y, 10M, 10C), a charging roller (not shown) for uniformly charging the photoreceptor drum 10, an exposure device 21 for exposing the photoreceptor drum 10 with exposure light L (see Figures 1 and 2) based on the image information of each color to form an electrostatic latent image of each color, a developing device for developing the electrostatic latent image with a developer of each color to form a toner image of each color, a transfer roller 62 for transferring the toner image onto an intermediate transfer belt 50, a cleaning device having a cleaning blade, and an anti-static lamp.

[0155] The toner images of each color formed by the respective color image forming units 120 are sequentially transferred (primary transfer) onto the intermediate transfer belt 50 which is stretched and moved on rollers 14, 15, and 16, and are superimposed to form a composite toner image.

[0156] Meanwhile, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed recording paper from one of the paper feed cassettes 144 arranged in multiple stages in the paper bank 143. Furthermore, the sheets are separated one by one by the separation roller 145 and sent to the paper feed path 146, transported by the transport roller 147 and guided to the paper feed path 148 in the main body of the copier 150, where they are stopped by the registration roller 49.

[0157] Alternatively, the paper feed roller rotates to feed the recording paper from the manual feed tray 54, separates it one sheet at a time with the separation roller 52, guides it to the manual feed path 53, and stops it against the registration roller 49. The registration roller 49 is generally used in a grounded state, but it may also be used with a bias applied to remove paper dust from the recording paper.

[0158] Next, by rotating the register roller 49 in time with the composite toner image formed on the intermediate transfer belt 50, recording paper is fed between the intermediate transfer belt 50 and the secondary transfer belt 24, and the composite toner image is transferred onto the recording paper (secondary transfer). Any toner remaining on the intermediate transfer belt 50 after the composite toner image has been transferred is removed by the cleaning device 17.

[0159] After the composite toner image is transferred to the recording paper, it is transported by the secondary transfer belt 24, and then the composite toner image is fixed by the fixing device 25. Next, the transport path of the recording paper is switched by the switching claw 55, and the recording paper is discharged onto the output tray 57 by the discharge roller 56. Alternatively, the transport path of the recording paper is switched by the switching claw 55, the sheet is inverted by the sheet inversion device 28, an image is formed on the back side in the same manner, and then the recording paper is discharged onto the output tray 57 by the discharge roller 56.

[0160] According to the image forming apparatus and image forming method of the present invention, since the toner of this disclosure, which has excellent low-temperature fixing properties and heat-resistant storage properties, is used, high-quality images can be provided over a long period of time. [Examples]

[0161] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited to these examples. In the following, "parts" refers to parts by mass, and "%" refers to mass percent. Furthermore, various tests and evaluations will be carried out according to the methods described below.

[0162] [Manufacturing example] (Manufacturing of amorphous polyester resin 1) In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet, the monomer species shown in Table 1 below and tetrabutoxytitanate as a condensation catalyst were placed and reacted at 230°C for 6 hours under a nitrogen stream, while distilling off the water produced. Next, the reaction was carried out under reduced pressure of 5 mmHg to 20 mmHg for 1 hour to obtain amorphous polyester resin 1 used in the example.

[0163] In Table 1, the "25 mol%" indicated for bisphenol A(2,2) ethylene oxide represents the proportion of the diol component when the acid component and alcohol component are both 50 mol%.

[0164] [Table 1]

[0165] (Manufacturing of amorphous polyester resin 2) In the production of amorphous polyester resin 1, amorphous polyester resin 2 was obtained by following the same procedure as before, except that the types of monomers used were changed as shown in Table 2 below.

[0166] [Table 2]

[0167] (Manufacturing of crystalline polyester 1) Fumaric acid and 1,6-hexanediol were placed in a 5L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple so that the OH / COOH ratio of the fumaric acid and 1,6-hexanediol was 0.9. The mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin component) at 180°C for 10 hours, then the temperature was raised to 200°C and the reaction was continued for 3 hours, followed by a reaction at a pressure of 8.3 kPa for 2 hours to obtain a crystalline polyester with a melting point of 103°C.

[0168] (Manufacturing of crystalline polyester 2) Fumaric acid and 1,6-hexanediol were charged into a 5L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple so that the OH / COOH ratio of the fumaric acid and 1,6-hexanediol was 0.93. The mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin component) at 180°C for 10 hours, then the temperature was raised to 200°C and the reaction was continued for 3 hours, followed by a reaction at a pressure of 8.3 kPa for 2 hours to obtain a crystalline polyester with a melting point of 117°C.

[0169] (Manufacturing of crystalline polyester 3) Fumaric acid and 1,6-hexanediol were charged into a 5L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple so that the OH / COOH ratio of the fumaric acid and 1,6-hexanediol was 0.85. The mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin component) at 180°C for 10 hours, then the temperature was raised to 200°C and the reaction was continued for 3 hours, followed by a reaction at a pressure of 8.3 kPa for 2 hours to obtain a crystalline polyester with a melting point of 97°C.

[0170] (Manufacturing of crystalline polyester 4) Fumaric acid and 1,6-hexanediol were charged into a 5L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple so that the OH / COOH ratio of the fumaric acid and 1,6-hexanediol was 0.96. The mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin component) at 180°C for 10 hours, then the temperature was raised to 200°C and the reaction was continued for 3 hours, followed by a reaction at a pressure of 8.3 kPa for 2 hours to obtain a crystalline polyester with a melting point of 123°C.

[0171] [Examples and Comparative Examples] (Example 1) —Creating Toner 1— Amorphous polyester resin 1: 77.5 parts Crystalline polyester resin 1: 10 parts Aromatic petroleum resin: Styrene copolymer (manufactured by Mitsui Chemicals, FTR-2140) 7.5 parts Wax: Fischer-Tropsch wax (manufactured by Nippon Seiro Co., Ltd., FNP-0090) 5 parts Carbon black (Mitsubishi Chemical Co., Ltd., #44): 10 parts

[0172] Following the above formulation, the toner raw materials were pre-mixed using a Henschel mixer (Mitsui Miike Chemical Machinery Co., Ltd., FM20B), then melted and kneaded at 120°C in a twin-screw kneader (Ikegai Iron Works Co., Ltd., PCM-30). The resulting kneaded material was rolled to a thickness of 2.7 mm using rollers, cooled to room temperature using a belt cooler, and then coarsely ground to 200 μm to 300 μm using a hammer mill.

[0173] Next, the material was finely ground using a supersonic jet pulverizer, LabJet (manufactured by Nippon Pneumatic Industry Co., Ltd.), and then classified using an airflow classifier (MDS-I, manufactured by Nippon Pneumatic Industry Co., Ltd.) while appropriately adjusting the louver opening to obtain toner matrix particles 1 of Example 1.

[0174] (Examples 2-9, Comparative Examples 1-5) —Creating Toners 2-14— Except for changing the type and quantity of amorphous polyester resin, the type of crystalline polyester resin, the type and quantity of aromatic petroleum resin, and the type of wax used as shown in Table 3 below, toners 2 to 14 of Examples 2 to 9 and Comparative Examples 1 to 5 were obtained by following the same procedure.

[0175] [Table 3]

[0176] The manufacturers, compositions, and physical properties of the aromatic petroleum resins and waxes used are shown in Tables 4 and 5 below.

[0177] [Table 4]

[0178] [Table 5]

[0179] (Preparation of toner developer) To 100 parts by mass of the above toners (toners 1-14), 1 part of metal oxide fine particles (Clariant, HDK-2000) was mixed and stirred in a Henschel mixer to prepare externally treated toner. 5% of this externally treated toner and 95% of the coating ferrite carrier were uniformly mixed at 48 rpm for 5 minutes using a tarbler mixer (Willi e Bakkofen (WAB)) to prepare a toner developer.

[0180] Using this toner developer, the low-temperature fixing properties, heat resistance, durability, and blocking resistance were evaluated using the following evaluation methods.

[0181] (Crushable) In the toner matrix particle manufacturing process, the weight-average particle size was measured after fine grinding using a supersonic jet pulverizer, LabJet (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), and the pulverization performance was evaluated based on the following criteria. Evaluations A and B indicate that the pulverization performance is good for practical use.

[0182] -Evaluation Criteria for Grinding Properties- A: Less than 5.3 μm B: 5.3 μm or more and less than 5.5 μm C:5.5μm or more

[0183] (Low temperature fixation) The above-mentioned toner developer was placed in a copier (RICOH MPC 6003, manufactured by Ricoh Corporation) and an image was printed. Adhesion amount: 0.4 mg / cm² 2 The solid image was printed onto paper (Ricoh Type 6200) through exposure, development, and transfer processes. The fixing line speed was 256 mm / second. The fixing temperature was sequentially set at 5°C increments, and the lower limit temperature at which cold offset did not occur (lower fixing temperature: low-temperature fixing performance) was measured. The NIP width of the fixing device was 11 mm.

[0184] The low-temperature fixability was evaluated based on the following evaluation criteria. Ratings A and B indicate good low-temperature fixability for practical use.

[0185] -Evaluation Criteria for Low-Temperature Fixation- A: Below 120℃ B: 120℃ or higher, but less than 130℃ C: 130℃ or higher

[0186] (Heat-resistant storage stability) Toner matrix particles were stored at 50°C for 24 hours, and the penetration depth was measured according to JIS K2235 (25°C). A VR-5610 penetration meter (manufactured by Shimadzu Corporation) was used to measure the penetration depth. Heat resistance was evaluated based on the following evaluation criteria. Evaluations A and B indicate good heat resistance for practical use.

[0187] -Evaluation criteria for heat resistance and storage properties- A: 4.0mm or larger B: 0.5mm or more and less than 4.0mm C: Less than 0.5mm

[0188] (durability) Using a low-temperature fixing copier (Ricoh, imajioMF-6550), 100,000 copies of a test chart with an image area of ​​6% were made, and the degree of decrease in the charge of the developer was evaluated. Durability was evaluated based on the following evaluation criteria. Evaluations A and B indicate good durability for practical use.

[0189] A: Very little decrease in charge level and excellent durability. B: Less decrease in charge level, superior durability compared to conventional toners. C: Low durability, equivalent to or less than conventional toners.

[0190] (Blocking resistance) In the fixation evaluation, images evaluated at the fixation lower limit + 10°C were cut into 2cm x 5cm sections, the image surfaces were overlapped, and sandwiched between glass slides. A 50ml ointment bottle containing 60g of ferrite carrier was placed on the glass slide, and the slides were left for 24 hours at varying storage temperatures. After cooling for 1 hour, the degree of image detachment was checked. The rank was determined by the temperature at which image detachment ceased.

[0191] The blocking resistance was evaluated based on the following evaluation criteria. Ratings A and B indicate good blocking resistance in practical terms.

[0192] A: The temperature at which image peeling stops is 75℃ or higher. B: The temperature at which image peeling stops is between 70°C and 75°C. C: The temperature at which image peeling stops is below 70°C.

[0193] The evaluation results for each toner are shown in Table 6 below.

[0194] [Table 6]

[0195] Table 6 shows that the toners of Examples 1 to 9 exhibit excellent pulverability, low-temperature fixability, heat resistance, durability, and blocking resistance.

[0196] In contrast, the toners of Comparative Examples 1 to 5 were inferior in at least one of the following aspects: pulverizability, low-temperature fixability, heat resistance, durability, and blocking resistance.

[0197] Although embodiments of the present invention have been described above, the present invention is not limited to any particular embodiment, and various modifications and changes are possible within the scope of the invention as described in the claims. [Explanation of Symbols]

[0198] 10. Electrostatic latent image carrier (photoreceptor drum) 14 Laura 15 Laura 16 Laura 17 Cleaning device 18 Image forming means 20 Electrostatic Rollers 21 Exposure equipment 22 Secondary transfer device 23 Laura 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet reversing device 32 Contact Glasses 33. First running unit 34. Second running unit 35. Imaging lens 36 Reading Sensors 40 Developing equipment 41 Developing belt 42 Developer storage section 42K Developer Storage Compartment 42Y Developer storage section 42M Developer storage section 42C Developer storage section 43 Developer supply roller 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44 Developing roller 44K developing roller 44Y Developing Roller 44M developing roller 44C Developing Roller 45 Developing Unit 45K Black Developer Unit 45Y Yellow Developer Unit 45M Magenta Developer Unit 45C Cyan Developer Unit 49 Registrola 50 Intermediate transfer belt 51 Laura 52 Separation Roller 53 Manual feed path 54 Manual feed tray 55 Switching claw 56 Discharge Roller 57 Paper output tray 58 Corona charging device 60 Cleaning device 62 Transfer Roller 70 Static electricity removal lamp 80 Transfer Rollers 90 Cleaning device 95 Transfer paper 100A, 100B, 100C image forming device 120 Image forming units 120Y Image Forming Unit 120C Image Forming Unit 120M Image Forming Unit 120K Image Forming Unit 130 Manuscript Stand 142 Paper feed roller 143 Paper Bank 144 Paper feed cassette 145 Separation Roller 146 Paper feed path 147 Conveyor rollers 148 Paper feed path 150 Copying device main unit 200 Paper feed table 300 Scanners 400 Automatic Document Feeder (ADF) [Prior art documents] [Patent Documents]

[0199] [Patent Document 1] Patent No. 5152372 [Patent Document 2] Patent No. 4535017 [Patent Document 3] Japanese Patent Publication No. 2007-264222 [Patent Document 4] Patent No. 3525216 [Patent Document 5] Japanese Patent Publication No. 2014-056143

Claims

1. It contains amorphous polyester resin, crystalline polyester resin, hydrocarbon wax, and resin synthesized from styrene as raw materials. The mass ratio of the resin synthesized using styrene as a raw material to the hydrocarbon wax is 1.0 or more. The amorphous polyester resin contains a bisphenol A alkylene oxide adduct and ethylene glycol as diol components. toner.

2. The alkylene oxide adduct of bisphenol A is at least one of an ethylene oxide adduct and a propylene oxide adduct of bisphenol A. The toner according to claim 1.

3. The melting point of the crystalline polyester resin is 90°C or higher and 130°C or lower. The toner according to claim 1 or 2.

4. The resin synthesized using the aforementioned styrene as a raw material is a styrene copolymer. The toner according to any one of claims 1 to 3.

5. The weight-average molecular weight of the resin synthesized using the aforementioned styrene as a raw material is 1000 or more and 4000 or less. The toner according to any one of claims 1 to 4.

6. The hydrocarbon wax is Fischer-Tropsch wax. The toner according to any one of claims 1 to 5.

7. Electrostatic latent image carrier, An electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, A developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier using pulverized toner to form a pulverized toner image, A transfer unit that transfers the pulverized toner image formed on the electrostatic latent image carrier to the surface of the recording medium, The recording medium includes a fixing unit for fixing the pulverized toner image transferred to its surface, The pulverized toner is the toner described in any one of claims 1 to 6. Image forming apparatus.

8. Using the image forming apparatus described in claim 7, a toner image is formed on a recording medium using the toner described in any one of claims 1 to 6. A method for manufacturing printed materials.

9. An electrostatic latent image formation step in which an electrostatic latent image is formed on an electrostatic latent image carrier, A developing step in which the electrostatic latent image formed on the electrostatic latent image carrier is developed using pulverized toner to form a pulverized toner image, A transfer step of transferring the pulverized toner image formed on the electrostatic latent image carrier to the surface of the recording medium, The process includes fixing the pulverized toner image transferred to the surface of the recording medium, The pulverized toner is the toner described in any one of claims 1 to 6. Image forming method.

Images