JP7725834B2 - Toner, image forming apparatus and method, and method for producing printed matter - Google Patents

Description

The present invention relates to a toner, an image forming apparatus and method, and a method for producing printed matter.

The growing need for energy conservation has created a demand for low-temperature fixing toner. To ensure low-temperature fixing properties, it is necessary to ensure the toner's heat-resistant storage properties, but it is also important to maintain the durability of the developer when used in actual machines for long periods of time.

In recent years, electrophotographic systems have been used for a wide range of purposes, from office use to mass printing. When performing continuous double-sided printing in particular, there is a risk of blocking occurring due to high temperatures after paper ejection.

In order to ensure toner durability and prevent blocking, it is important to adjust the wax dispersibility and thermal properties. Furthermore, wax also plays a role in ensuring low-temperature fixability and heat-resistant storage stability. From this perspective, the use of waxes other than the conventionally used paraffin wax and ester wax is being investigated.
As such a toner, for example, a toner using a ketone wax has been proposed (see, for example, Patent Documents 1 to 5).

The present invention aims to provide a toner that combines low-temperature fixability and heat-resistant storage stability, while also having excellent toner durability and preventing image blocking during continuous paper feed.

The toner of the present invention as a means for solving the above problems contains a binder resin and a release agent containing a ketone compound, the binder resin contains an amorphous polyester resin, and when the glass transition temperature (Tg) of the amorphous polyester resin is A (°C) and the glass transition temperature (Tg) of a toner containing 10% by mass of the release agent relative to the amorphous polyester resin is B (°C), the toner satisfies A-B>5 (°C).

The present invention makes it possible to provide a toner that combines low-temperature fixability and heat-resistant storage stability, while also exhibiting excellent toner durability and preventing image blocking during continuous paper feed.

FIG. 1 is a schematic explanatory view showing an example of an image forming apparatus of the present invention. FIG. 2 is a schematic explanatory view showing another example of the image forming apparatus of the present invention. FIG. 3 is a schematic explanatory view showing another example of the image forming apparatus of the present invention. FIG. 4 is a schematic explanatory diagram showing an example of an image forming unit in the image forming apparatus of the present invention. FIG. 5 is a diagram showing an example of an image obtained by SEM observation and EDS measurement of the toner in Example 1.

(toner)
The toner of the present invention contains a binder resin and a release agent containing a ketone compound, and satisfies A-B>5(°C), where A (°C) is the glass transition temperature (Tg) of the binder resin alone and B (°C) is the glass transition temperature (Tg) of the binder resin containing 10% by mass of the release agent. The toner of the present invention further contains other components as necessary.

The release agent containing the ketone compound has a high melting point, and precipitates on the image surface after toner fixation, thereby improving the hardness of the image itself. The present inventors have found that, in the case of continuous double-sided paper feed, blocking of the image can be suppressed even if the image surface is in a high temperature state.
Furthermore, the present inventors have found that, when the glass transition temperature (Tg) of the binder resin alone is A (°C) and the glass transition temperature (Tg) of a binder resin containing 10% by mass of the release agent is B (°C), by satisfying A-B>5°C, the compatibility of the release agent (wax) with the binder resin can be improved. By increasing the compatibility of the release agent (wax) with the binder resin, the dispersibility of the release agent (wax) in the toner can be improved. By improving the dispersibility of the release agent (wax) in the toner, the durability of the developer can be improved when used for a long period of time in an actual machine.
The temperature AB is preferably AB>5°C, and more preferably 6°C≦AB≦8°C.

The toner of the present invention contains a release agent containing a ketone compound, a binder resin, a styrene resin, hydrophobic silica particles, and, if necessary, a colorant, and further contains other components if necessary.
First, each component of the toner of the present invention will be described.

<Release Agent>
The release agent contains a ketone compound and, if necessary, further contains other components.

The release agent containing the ketone compound can be obtained, for example, by decarboxylating a fatty acid at high temperature in the presence of a metal oxide catalyst. Since this production method produces a large amount of impurities, it is preferable to purify the product as needed.

The fatty acid is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include caproic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachic acid, behenic acid, isostearic acid, etc. Among these, fatty acids having a carbon number equal to or greater than that of lauric acid are preferred, and stearic acid and behenic acid are particularly preferred, since a smaller carbon number would result in an excessively low melting point of the release agent.
Furthermore, compared to unsaturated fatty acids and branched fatty acids, the use of straight-chain saturated fatty acids is preferable because it can improve the hardness of the release agent and suppress spent on the carrier when used in a toner.
In view of the above and from the industrial and cost standpoints, the release agent containing a ketone compound in the present invention is preferably a ketone compound derived from a fatty acid having 18 or more carbon atoms.

The melting point of the release agent is preferably 80°C or higher and 95°C or lower, and more preferably 85°C or higher and 90°C or lower. By having the melting point of the release agent be 80°C or higher and 95°C or lower, it is possible to achieve both low-temperature fixability and the effect of preventing image blocking.

The acid value of the release agent is preferably 1 or greater, and more preferably 1 or greater and 5 or less. When the acid value of the release agent is 1 or greater, compatibility with the binder resin can be ensured while maintaining heat-resistant storage stability, and good dispersibility of the release agent (wax) can be ensured.

The content of the release agent is preferably 1 part by weight to 20 parts by weight, and more preferably 3 parts by weight to 10 parts by weight, per 100 parts by weight of binder resin. If the content of the release agent is less than 1 part by weight, the amount relative to the binder resin may be too small to achieve sufficient release properties. If the content of the release agent is more than 20 parts by weight, wax-spent on the carrier, charging member, and other members may increase, which may cause problems in practical use.

The content of the ketone compound in the release agent is not particularly limited as long as it is within a range that achieves the effects of the present invention, and can be selected appropriately depending on the purpose. For example, it is preferably 1 part by mass or more and 20 parts by mass or less, and more preferably 3 parts by mass or more and 10 parts by mass or less, per 100 parts by mass of binder resin.

<<Other ingredients>>
The other components are not particularly limited and can be appropriately selected depending on the purpose, and known mold release agents can be used.
Examples of waxes include carbonyl group-containing waxes, polyolefin waxes, long-chain hydrocarbons, amide waxes, and aliphatic carboxylates. These may be used alone or in combination of two or more.

Examples of the carbonyl group-containing wax include polyalkanoic acid esters, polyalkanol esters, polyalkanoic acid amides, and polyalkylamides.
Examples of the polyalkanoic acid ester include carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, and 1,18-octadecanediol distearate.
Examples of the polyalkanol ester include tristearyl trimellitate and distearyl maleate.
Examples of the polyalkanoic acid amide include dibehenylamide.
Examples of the polyalkylamide include trimellitic acid tristearylamide.
Among these, polyalkanoic acid esters are particularly preferred.

Examples of the polyolefin wax include polyethylene wax and polypropylene wax.

Examples of the long-chain hydrocarbons include paraffin wax and sazol wax.

The amide waxes include lauric amide, palmitic amide, stearic amide, erucic amide, behenic amide, N-stearyl stearic amide, methylol stearic amide, methylol behenic amide, dimethylitol oil amide, dimethyl lauric amide, dimethyl stearic amide, ethylene bisoleic amide, ethylene bisstearic amide, methylene bisstearic amide, ethylene bislauric amide, hexamethylene bisoleic amide, hexamethylene Examples include m-xylylene bisstearic acid amide, butylene bisstearic acid amide, m-xylylene bisstearic acid amide, m-xylylene bis-12 hydroxystearic acid amide, N,N'-dioleyl adipamide, N,N'-distearyl adipamide, N,N'-distearyl isophthalamide, N,N'-distearyl terephthalamide, N-butyl-N'stearyl urea, N-propyl-N'stearyl urea, N-allyl-N'stearyl urea, and N-stearyl-N'stearyl urea.

Examples of the aliphatic carboxylate salts include sodium laurate, potassium laurate, potassium hydrogen laurate, magnesium laurate, calcium laurate, zinc laurate, silver laurate, lithium myristate, sodium myristate, potassium hydrogen myristate, magnesium myristate, calcium myristate, zinc myristate, silver myristate, lithium palmitate, potassium palmitate, magnesium palmitate, calcium palmitate, zinc palmitate, copper palmitate, lead palmitate, thallium palmitate, cobalt palmitate, sodium oleate, potassium oleate, magnesium oleate, calcium oleate, zinc oleate, lead oleate, thallium oleate, copper oleate, nickel oleate, sodium stearate, lithium stearate, Examples include magnesium phosphate, calcium stearate, barium stearate, aluminum stearate, thallium stearate, lead stearate, nickel stearate, bevelium stearate, sodium isostearate, potassium isostearate, magnesium isostearate, calcium isostearate, barium isostearate, aluminum isostearate, zinc isostearate, nickel isostearate, sodium behenate, potassium behenate, magnesium behenate, calcium behenate, barium behenate, aluminum behenate, zinc behenate, nickel behenate, sodium montanate, potassium montanate, magnesium montanate, calcium montanate, barium montanate, aluminum montanate, zinc montanate, and nickel montanate.

The content of the known release agent is preferably, for example, 3 parts by mass or more and 10 parts by mass or less relative to the total amount of binder resin.

The following method can be mentioned as an example of a method for producing the release agent containing the ketone compound.
A fatty acid and a metal oxidation catalyst are charged into a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet pipe, and the temperature is raised to 250°C in a nitrogen atmosphere and the reaction is carried out for 8 hours. The temperature is then raised to 350°C and the reaction is continued for another 8 hours. The reaction is then cooled to 120°C and the excess metal oxidation catalyst is removed, thereby obtaining a release agent containing the ketone compound.
The metal oxidation catalyst is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include magnesium oxide.

<Styrene resin>
The toner of the present invention preferably contains a styrene resin.
The styrene resin is not particularly limited, but examples thereof include polymers of styrene and its substitution 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. These may be used alone, or two or more may be used in combination.

From the viewpoint of improving the effects of the present invention, the content of the styrene resin is preferably 2 parts by weight or more and 10 parts by weight or less, and more preferably 3 parts by weight or more and 6 parts by weight or less, per 100 parts by weight of the toner.

The glass transition temperature (Tg) of the styrene resin is preferably 60° C. or higher, and more preferably 65° C. or higher and 85° C. or lower. When the glass transition temperature (Tg) of the styrene resin is 60° C. or higher, the heat-resistant storage stability can be improved.
The glass transition temperature (Tg) is measured using a differential scanning calorimeter (Q-200, manufactured by TA Instruments). Specifically, about 5.0 mg of the target sample is placed in an aluminum sample container, which is then placed on a holder unit and set in an electric furnace. The sample is then heated from −80° C. to 150° C. at a heating rate of 10° C./min in a nitrogen atmosphere, and the glass transition temperature (Tg) of the target sample is determined from the obtained DSC curve using an analysis program in the differential scanning calorimeter.

<Hydrophobic Silica Particles>
The toner of the present invention preferably contains hydrophobic silica particles inside the toner particles. By containing the hydrophobic silica particles inside the toner particles, the dispersibility of the release agent (wax) can be improved.
Incidentally, the inclusion of hydrophobic silica particles inside the toner particles here means that there is a region where the hydrophobic silica particles are embedded inside the outermost surface of the toner, and it is not necessary that the entire hydrophobic silica particles are embedded inside the toner. In the present invention, the inclusion of hydrophobic silica particles inside the toner particles may be referred to as the hydrophobic silica particles being internally added inside the toner particles.

The content of the hydrophobic silica particles is preferably 0.1% by mass or more and 1% by mass or less, and more preferably 0.2% by mass or more and 0.5% by mass or less, relative to the total amount of the binder resin.

The average primary particle size of the hydrophobic silica particles is preferably 50 nm or less.
By combining these conditions, the dispersibility of the release agent (wax) can be improved more effectively.

The method for preparing the hydrophobic silica particles is not particularly limited and can be selected appropriately depending on the purpose. For example, a method in which the surface of the silica is treated with silicone oil can be used.

<Binder resin>
Examples of the binder resin include polyester resins, such as crystalline polyester resins and non-crystalline polyester resins.

<<<Crystalline resin>>>
Crystalline is defined as a substance in which atoms or molecules are arranged in a spatially repeating pattern, and is defined as a substance that shows a diffraction pattern when used with a general X-ray diffraction device.

The crystalline resin is not particularly limited as long as it has crystallinity and can be appropriately selected depending on the purpose. Examples of the crystalline resin include polyester resins, polyol resins, phenolic resins, silicone resins, polyurethane resins, polyurea resins, polyamide resins, polyether resins, vinyl resins (vinyl polymers composed of styrene-based monomers, acrylic monomers, methacrylic monomers, etc.), modified crystalline resins, furan resins, epoxy resins, xylene resins, terpene resins, coumarone-indene resins, polycarbonate resins, and petroleum-based resins.
These may be used alone or in combination of two or more. Among these, polyester resins, polyurethane resins, polyurea resins, polyamide resins, and polyether resins are preferred, resins having at least one of a urethane skeleton and a urea skeleton are preferred, and linear polyester resins and composite resins containing the linear polyester resins are more preferred.

Here, suitable examples of resins having at least one of a urethane skeleton and a urea skeleton include the polyurethane resin, polyurea resin, urethane-modified polyester resin, and urea-modified polyester resin. The urethane-modified polyester resin is a resin obtained by reacting a polyester resin having an isocyanate group at its terminal with a polyol. The urea-modified polyester resin is a resin obtained by reacting a polyester resin having an isocyanate group at its terminal with an amine.

Examples of the styrene-based monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-amylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-chlorostyrene, 3,4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, and p-nitrostyrene, as well as derivatives thereof.

Examples of the acrylic monomer include acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, n-dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate, as well as esters thereof.

Examples of the methacrylic monomer include methacrylic acid or its esters, such as methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, n-dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate.

Examples of other monomers that form the vinyl polymer or copolymer include the following (1) to (18).
(1) Monoolefins such as ethylene, propylene, butylene, and isobutylene;
(2) Polyenes such as butadiene and isoprene;
(3) Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride;
(4) vinyl esters such as vinyl acetate, vinyl propionate, and vinyl benzoate;
(5) Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether;
(6) Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone;
(7) N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone;
(8) vinylnaphthalenes;
(9) Acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide;
(10) Unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenylsuccinic acid, fumaric acid, and mesaconic acid;
(11) Unsaturated dibasic acid anhydrides such as maleic anhydride, citraconic anhydride, itaconic anhydride, and alkenylsuccinic anhydride;
(12) Monoesters of unsaturated dibasic acids, such as maleic acid monomethyl ester, maleic acid monoethyl ester, maleic acid monobutyl ester, citraconic acid monomethyl ester, citraconic acid monoethyl ester, citraconic acid monobutyl ester, itaconic acid monomethyl ester, alkenylsuccinic acid monomethyl ester, fumaric acid monomethyl ester, and mesaconic acid monomethyl ester;
(13) Unsaturated dibasic acid esters such as dimethyl maleate and dimethyl fumarate;
(14) α,β-unsaturated acids such as crotonic acid and cinnamic acid;
(15) α,β-unsaturated acid anhydrides such as crotonic anhydride and cinnamic anhydride;
(16) Monomers having a carboxyl group, such as anhydrides of the above-mentioned α,β-unsaturated acids and lower fatty acids, alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides thereof, and monoesters thereof;
(17) Acrylic acid or methacrylic acid hydroxyalkyl esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate;
(18) Monomers having a hydroxy group, such as 4-(1-hydroxy-1-methylbutyl)styrene and 4-(1-hydroxy-1-methylhexyl)styrene

Examples of polymerization initiators used in the production of the vinyl polymer or copolymer include 2,2'-azobisisobutyronitrile, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), dimethyl-2,2'-azobisisobutyrate, 1,1'-azobis(1-cyclohexanecarbonitrile), 2-(carbamoylazo)-isobutyronitrile, 2,2'-azobis(2,4,4-trimethylpentane), 2-phenylazo-2',4'-dimethyl-4' -Methoxyvaleronitrile, 2,2'-azobis(2-methylpropane), ketone peroxides such as methyl ethyl ketone peroxide, acetylacetone peroxide, and cyclohexanone peroxide, 2,2-bis(tert-butylperoxy)butane, tert-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-tert-butyl peroxide, tert-butylcumyl peroxide, dicumyl peroxide, α-(tert-butylperoxy)isopropylbenzene, isopropyl benzene, methyl ethyl ketone peroxide, methyl ethyl ketone peroxide, methyl ethyl ketone peroxide, methyl ethyl acetone ... Isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-tolyl peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate, diethoxyisopropyl peroxydicarbonate, di(3-methyl-3-methoxybutyl)peroxycarbonate, acetylcyclohexylsulfonyl peroxide Examples include peroxybenzoates, tert-butyl peroxyacetate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-2-ethylhexalate, tert-butyl peroxylaurate, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, di-tert-butyl peroxyisophthalate, tert-butyl peroxyaryl carbonate, isoamyl peroxy-2-ethylhexanoate, di-tert-butyl peroxyhexahydroterephthalate, and tert-butyl peroxyazelate.

In the toner of the present invention, the vinyl polymer or copolymer of the binder resin may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups.
Examples of the crosslinking agent include aromatic divinyl compounds, diacrylate compounds bonded with alkyl chains, diacrylate compounds bonded with alkyl chains containing ether bonds, polyester-type diacrylates, and polyfunctional crosslinking agents.
Examples of the aromatic divinyl compound include divinylbenzene and divinylnaphthalene.
Examples of the diacrylate compounds bonded with alkyl chains include ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and compounds in which the acrylate in these compounds is replaced with methacrylate.
Examples of the diacrylate compounds bonded by an alkyl chain containing an ether bond include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate (e.g., polyethylene glycol #400 diacrylate, polyethylene glycol #600 diacrylate), dipropylene glycol diacrylate, and compounds in which the acrylate in these compounds is replaced with methacrylate.
An example of the polyester diacrylates is MANDA (manufactured by Nippon Kayaku Co., Ltd.).
Examples of the polyfunctional crosslinking agent include pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate, and compounds in which the acrylate in the above compounds is replaced with methacrylate, triallyl cyanurate, and triallyl trimellitate.
Other examples include diacrylate compounds and dimethacrylate compounds linked by a chain containing an aromatic group and an ether bond.
Among these crosslinkable monomers, aromatic divinyl compounds (particularly divinylbenzene) and diacrylate compounds bonded by a bonding chain containing an aromatic group and one ether bond are preferred in terms of fixing property and offset resistance of toner resins.
Among these, combinations of monomers that result in styrene copolymers and styrene-acrylic copolymers are preferred.

The amount of the crosslinking agent is preferably 0.01 parts by mass or more and 10 parts by mass or less, and more preferably 0.03 parts by mass or more and 5 parts by mass or less, per 100 parts by mass of other monomers that form the vinyl polymer or copolymer.

From the viewpoint of achieving both low-temperature fixability and heat-resistant storage stability, the maximum peak temperature of the heat of fusion of the crystalline resin is preferably 45°C or higher and 70°C or lower, more preferably 53°C or higher and 65°C or lower, and particularly preferably 58°C or higher and 62°C or lower. If the maximum peak temperature is lower than 45°C, low-temperature fixability will be improved but heat-resistant storage stability will be deteriorated. Conversely, if it is higher than 70°C, heat-resistant storage stability will be improved but low-temperature fixability will be deteriorated.

The content of the crystalline resin is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total amount of the binder resin.
The upper limit of the content of the crystalline resin in the toner is not particularly limited and can be appropriately selected depending on the purpose. For example, it is 30% by mass or less with respect to the binder resin.

- Crystalline polyester resin -
In the toner of the present invention, a crystalline polyester resin having crystallinity may be used in order to promote low-temperature fixation.
The crystalline polyester resin may be a crystalline aliphatic polyester resin containing at least 60 mol % of ester bonds represented by the following general formula (1) in the molecular main chain.

In the general formula (1), R represents a linear unsaturated aliphatic dicarboxylic acid residue, and is a linear unsaturated aliphatic group having 2 to 20 carbon atoms, preferably 2 to 4 carbon atoms. n is an integer of 2 to 20, preferably 2 to 6.

The presence of the structure of general formula (1) can be confirmed by solid-state C ¹³ NMR.

Specific examples of the linear unsaturated aliphatic group include linear unsaturated aliphatic groups derived from linear unsaturated dicarboxylic acids such as maleic acid, fumaric acid, 1,3-n-propenedicarboxylic acid, and 1,4-n-butenedicarboxylic acid.

In the general formula (1), (CH ₂ )n represents a linear aliphatic dihydric alcohol residue.
Specific examples of the linear aliphatic dihydric alcohol residue in this case include those derived from linear aliphatic dihydric alcohols such as ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol.

The crystalline polyester resin uses a linear unsaturated aliphatic dicarboxylic acid as its acid component, and therefore exhibits the effect of being more likely to form a crystalline structure than when an aromatic dicarboxylic acid is used.
The crystalline polyester resin can be produced by a conventional polycondensation reaction of (I) a polycarboxylic acid component consisting of a linear unsaturated aliphatic dicarboxylic acid or a reactive derivative thereof (such as an acid anhydride, a lower alkyl ester having 1 to 4 carbon atoms, or an acid halide) and (II) a polyhydric alcohol component consisting of a linear aliphatic diol.
In this case, a small amount of other polycarboxylic acid may be added to the polycarboxylic acid component, if necessary.
In this case, the polycarboxylic acids include:
(I) a branched unsaturated aliphatic dicarboxylic acid,
(II) saturated aliphatic dicarboxylic acids, saturated aliphatic tricarboxylic acids, and other saturated aliphatic polycarboxylic acids,
(III) Aromatic polycarboxylic acids such as aromatic dicarboxylic acids and aromatic tricarboxylic acids are included.
The amount of these polycarboxylic acids to be added is usually 30 mol % or less, preferably 10 mol % or less, based on the total amount of carboxylic acids, and is appropriately added within a range in which the resulting polyester has crystallinity.

The crystalline polyester resin is synthesized from, for example, a polycarboxylic acid component and a polyhydric alcohol component.
In the present embodiment, the crystalline polyester resin may be a commercially available product or may be synthesized.

--Polycarboxylic acid component--
Examples of polycarboxylic acid components include dicarboxylic acid components and tricarboxylic or higher carboxylic acid components.

Examples of the dicarboxylic acid component include aliphatic dicarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, and 1,18-octadecanedicarboxylic acid; and aromatic dicarboxylic acids such as dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, and mesaconic acid; and further include, but are not limited to, anhydrides and lower alkyl esters thereof.
Examples of trivalent or higher carboxylic acids include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, 1,2,7,8-octanetetracarboxylic acid, and the like, as well as anhydrides and lower alkyl esters thereof. These may be used alone or in combination of two or more.
The acid component may contain a dicarboxylic acid component having a sulfonic acid group in addition to the aliphatic dicarboxylic acid or aromatic dicarboxylic acid, or a dicarboxylic acid component having a double bond in addition to the aliphatic dicarboxylic acid or aromatic dicarboxylic acid.
The acid component may contain a dicarboxylic acid component having a sulfonic acid group in addition to the aliphatic dicarboxylic acid or aromatic dicarboxylic acid, or a dicarboxylic acid component having a double bond in addition to the aliphatic dicarboxylic acid or aromatic dicarboxylic acid.

--Polyhydric alcohol component--
As the polyhydric alcohol component, diols; small amounts of aliphatic branched chain dihydric alcohols and cyclic dihydric alcohols; and trihydric or higher polyhydric alcohols can be added.
The diol is preferably an aliphatic diol, and more preferably a linear aliphatic diol having 7 to 20 carbon atoms in the main chain. If the aliphatic diol is branched, the crystallinity of the polyester resin may decrease, resulting in a lower melting point. Furthermore, if the main chain has fewer than 7 carbon atoms, the melting temperature may increase when polycondensed with an aromatic dicarboxylic acid, making low-temperature fixing difficult. On the other hand, if the main chain has more than 20 carbon atoms, it may be difficult to obtain a practical material. It is more preferable that the main chain has 14 or fewer carbon atoms.

---Aliphatic diol---
Specific examples of the aliphatic diol include, but are not limited to, ethylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,14-eicosanedecanediol. Of these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferred in terms of availability.
Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, etc. These may be used alone or in combination of two or more.
The content of the aliphatic diol in the polyhydric alcohol component is preferably 80 mol % or more, more preferably 90 mol % or more. If the content of the aliphatic diol is less than 80 mol %, the crystallinity of the polyester resin decreases, and the melting temperature drops, which may result in deterioration of toner blocking resistance, image storability, and low-temperature fixability.

Examples of trihydric or higher alcohols include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol (e.g., dipentaerythritol, tripentaerythritol), 1,2,4-butanetriol, 1,2,5-pentatriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, glycerin, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, 1,4-bis(hydroxymethyl)cyclohexane, polyethylene glycol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, glycerin, and the like. These may be used alone or in combination of two or more.

The content of the polyhydric alcohol component is preferably 30 mol% or less, more preferably 10 mol% or less, based on the total alcohol components, and is added appropriately within a range that allows the resulting polyester to be crystalline.

If necessary, polycarboxylic acids or polyhydric alcohols may be added at the final stage of synthesis to adjust the acid value or hydroxyl value.

Examples of the polyvalent carboxylic acid include benzenedicarboxylic acids such as terephthalic acid, isophthalic acid, and terephthalic acid, or anhydrides thereof; aromatic carboxylic acids such as phthalic anhydride, trimellitic anhydride, pyromellitic acid, and naphthalenedicarboxylic acid; aliphatic carboxylic acids such as maleic anhydride, fumaric acid, succinic acid, alkenylsuccinic acid, alkenylsuccinic anhydride, mesaconic acid, and adipic acid; alicyclic carboxylic acids such as cyclohexanedicarboxylic acid; and unsaturated dibasic acid anhydrides such as maleic anhydride, citraconic anhydride, itaconic anhydride, and alkenylsuccinic anhydride.
Examples of the trivalent or higher polyvalent carboxylic acid component include trimellitic acid, pyromellic 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 anhydrides or partial lower alkyl esters thereof.

Examples of the polyhydric alcohol include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, and glycerin; alicyclic diols such as cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, and hydrogenated bisphenol A; and aromatic diols such as ethylene oxide adducts of bisphenol A and propylene oxide adducts of bisphenol A.

[Preparation of crystalline polyester resin]
The crystalline polyester resin can be produced, for example, at a polymerization temperature of 180° C. or higher and 230° C. or lower, and the reaction is carried out while reducing the pressure in the reaction system as necessary and removing water and alcohol generated during condensation.
If the polymerizable monomer is not soluble or compatible at the reaction temperature, a high-boiling solvent may be added as a solubilizing agent to dissolve it. The polycondensation reaction is carried out while distilling off the solubilizing agent. If a polymerizable monomer with poor compatibility is present in the copolymerization reaction, it is advisable to first condense the poorly compatible polymerizable monomer with the acid or alcohol to be polycondensed, and then polycondense the resulting polymerizable monomer with the main component.

Examples of catalysts that can be used in producing the crystalline polyester resin include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; metal compounds such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium; phosphorous compounds; phosphoric acid compounds; and amine compounds.

Specific examples include compounds such as sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, zinc stearate, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, antimony trioxide, triphenylantimony, tributylantimony, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, zirconium tetrabutoxide, zirconium naphthenate, zirconyl carbonate, zirconyl acetate, zirconyl stearate, zirconyl octoate, germanium oxide, triphenyl phosphite, tris(2,4-di-t-butylphenyl)phosphite, ethyltriphenylphosphonium bromide, triethylamine, and triphenylamine.

The acid value of the crystalline polyester resin (the number of mg of KOH required to neutralize 1 g of resin) 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 particularly preferably 0.1 mg KOH/g or more and 50 mg KOH/g or less.
When the crystalline polyester resin is a vinyl polymer such as a styrene-acrylic resin, the acid value thereof is preferably 0.1 mgKOH/g or more and 100 mgKOH/g or less, more preferably 0.1 mgKOH/g or more and 70 mgKOH/g or less, and particularly preferably 0.1 mgKOH/g or more and 50 mgKOH/g or less.

The molecular weight distribution of the crystalline polyester resin is preferably sharp from the viewpoint of low temperature fixability, and the molecular weight is preferably relatively low.
In the molecular weight distribution by GPC of the o-dichlorobenzene soluble portion of the crystalline polyester resin, the weight average molecular weight (Mw) is preferably 5,500 or more and 6,500 or less, and the number average molecular weight (Mn) is preferably 1,300 or more and 1,500 or less.
The crystalline polyester resin preferably has an Mw/Mn ratio of 2 or more and 5 or less.
The molecular weight distribution of the crystalline polyester resin is based on a molecular weight distribution chart in which the horizontal axis is log M (M is molecular weight) and the vertical axis is mass %.
In the case of the crystalline polyester resin used in the present invention, it is preferable that the molecular weight distribution diagram has a molecular weight peak in the range of 3.5 to 4.0, and the half-value width of the peak is preferably 1.5 or less.

The weight-average molecular weight can be measured by gel permeation chromatography (GPC). Molecular weight measurements by GPC were performed using a Tosoh GPC HLC-8120 measuring device, a Tosoh TSKgel Super HM-M (15 cm) column, and THF solvent. The weight-average molecular weight was calculated from the measurement results using a molecular weight calibration curve created with monodisperse polystyrene standard samples.

Crystalline resins, including the above-mentioned crystalline polyester resins, preferably contain a crystalline polyester resin synthesized using an aliphatic polymerizable monomer (hereinafter sometimes referred to as a "crystalline aliphatic polyester resin") as the main component (50% by mass or more). Furthermore, in this case, the composition ratio of the aliphatic polymerizable monomer that constitutes the crystalline aliphatic polyester resin is preferably 60 mol% or more, and more preferably 90 mol% or more. The aforementioned aliphatic diols and dicarboxylic acids can be suitably used as the aliphatic polymerizable monomer.

As the binder resin that can be used in the toner of the present invention, a resin containing a vinyl polymer component in a polyester resin component can also be used.
In this case, a resin containing, in at least one of the vinyl polymer component and the polyester resin component, a monomer component capable of reacting with both of these resin components can also be used.
Among the monomers constituting the polyester resin component, those capable of reacting with vinyl polymers include, for example, unsaturated dicarboxylic acids such as phthalic acid, maleic acid, citraconic acid, itaconic acid, and the like, or anhydrides thereof.
Examples of the monomers constituting the vinyl polymer component include those having a carboxyl group or a hydroxyl group, and acrylic acid or methacrylic acid esters.

When a polyester polymer or a vinyl polymer is used in combination with another binder resin, it is preferable that the total binder resin contains 60% by mass or more of resins having an acid value of 0.1 mgKOH/g or more and 50 mgKOH/g or less.
In the present invention, the acid value of the binder resin component of the toner composition is measured in accordance with JIS K-0070.

The toner preferably contains 1% by weight or more of crystalline polyester resin, preferably 5% by weight or more, and more preferably 10% by weight or more.

The melting point of the crystalline polyester resin is preferably in the range of 45° C. or higher and 70° C. or lower, more preferably in the range of 53° C. or higher and 65° C. or lower, and even more preferably in the range of 58° C. or higher and 62° C. The melting point of the crystalline polyester resin was determined by the following method as the peak temperature of the endothermic peak obtained by differential scanning calorimetry (DSC).
In differential scanning calorimetry (DSC) using a differential scanning calorimeter (DSC-60 model) manufactured by Shimadzu Corporation equipped with an automatic tangent processing system, the temperature is increased at a rate of 10°C/min. The endothermic peak at this time is taken as the melting point.

The crystalline polyester resin refers not only to polymers whose constituent components are 100% polyester, but also to polymers (copolymers) formed by polymerizing polyester components together with other components. However, in the latter case, the other constituent components other than polyester that make up the polymer (copolymer) are 50% by mass or less.

The melting point (Tm) and softening temperature (T _1/2 ) of the crystalline polyester resin are desirably low within a range that does not deteriorate the heat-resistant storage stability of the toner. In general, the melting point (Tm) is preferably 80°C or higher and 130°C or lower, and more preferably 80°C or higher and 125°C or lower.
The softening temperature (T _1/2 ) of the crystalline polyester resin is preferably 80° C. or higher and 130° C. or lower, and more preferably 80° C. or higher and 125° C. When the melting point (Tm) and the softening temperature (T _1/2 ) are 80° C. or higher and 130° C. or lower, the low-temperature fixability of the toner can be improved.

<<<Amorphous resin>>>
The amorphous resin is not particularly limited and can be appropriately selected depending on the purpose, but amorphous polyester resin is preferred.

- Amorphous polyester resin -
The amorphous polyester resin may be a modified polyester resin or an unmodified polyester resin, and it is more preferable to use both of them.

--Modified polyester resin--
The modified polyester resin may be any of the modified polyester resins shown below. For example, a polyester prepolymer having an isocyanate group may be used. Examples of the polyester prepolymer (A) having an isocyanate group include a product in which a polyester having an active hydrogen group, which is a polycondensate of a polyol (1) and a polycarboxylic acid (2), is further reacted with a polyisocyanate (3). Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, and a mercapto group. Of these, an alcoholic hydroxyl group is preferred.
A modified polyester resin can be obtained by reacting a polyester prepolymer having an isocyanate group with a crosslinking agent and/or an extender.

Examples of polyol (1) include diol (1-1) and trihydric or higher polyol (1-2), and (1-1) alone or a mixture of (1-1) and a small amount of (1-2) is preferred.

Examples of diols (1-1) include alkylene glycols (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycols (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts of the above alicyclic diols; and alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts of the above bisphenols. Of these, alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols are preferred, and alkylene oxide adducts of bisphenols and their combination with alkylene glycols having 2 to 12 carbon atoms are particularly preferred.

Examples of trihydric or higher polyols (1-2) include trihydric to octahydric or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (trisphenol PA, phenol novolac, cresol novolac, etc.); and alkylene oxide adducts of the above trihydric or higher polyphenols.

The polycarboxylic acid (2) includes dicarboxylic acids (2-1) and trivalent or higher polycarboxylic acids (2-2), and (2-1) alone and a mixture of (2-1) and a small amount of (2-2) are preferred.
Examples of the dicarboxylic acid (2-1) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.), alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.), and aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.). Among these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms.
Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, etc.). The polycarboxylic acid (2) may be an acid anhydride or a lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned compounds, which may be reacted with the polyol (1).

The ratio of polyol (1) to polycarboxylic acid (2), expressed as the equivalent ratio [OH]/[COOH] of hydroxyl groups [OH] to carboxyl groups [COOH], is typically 2/1 to 1/1, preferably 1.5/1 to 1/1, and more preferably 1.3/1 to 1.02/1.

Examples of polyisocyanates (3) include aliphatic polyisocyanates (such as tetramethylene diisocyanate, hexamethylene diisocyanate, and 2,6-diisocyanatomethyl caproate); alicyclic polyisocyanates (such as isophorone diisocyanate and cyclohexylmethane diisocyanate); aromatic diisocyanates (such as tolylene diisocyanate and diphenylmethane diisocyanate); araliphatic diisocyanates (such as α,α,α',α'-tetramethylxylylene diisocyanate); isocyanurates; the above polyisocyanates blocked with phenol derivatives, oximes, caprolactam, etc.; and combinations of two or more of these.

The ratio of polyisocyanate (3), expressed as the equivalent ratio [NCO]/[OH] of the isocyanate group [NCO] to the hydroxyl group [OH] of the polyester having hydroxyl groups, is typically 5/1 to 1/1, preferably 4/1 to 1.2/1, and more preferably 2.5/1 to 1.5/1.

The content of the polyisocyanate (3) component in the prepolymer (A) having an isocyanate group at its terminal is typically 0.5% by mass or more and 40% by mass or less, preferably 1% by mass or more and 30% by mass or less, and more preferably 2% by mass or more and 20% by mass or less.

The isocyanate group-containing prepolymer (A) typically contains one or more isocyanate groups per molecule, preferably an average of 1.5 to 3, and more preferably an average of 1.8 to 2.5. If there is less than one isocyanate group per molecule, the molecular weight of the modified polyester after crosslinking and/or elongation will be low, resulting in poor hot offset resistance.

---Crosslinking agents and extenders---
Amines can be used as crosslinking agents and/or extenders.
Examples of the amines (B) include diamines (B1), trivalent or higher polyamines (B2), amino alcohols (B3), amino mercaptans (B4), amino acids (B5), and compounds (B6) in which the amino groups of B1 to B5 have been blocked.

Examples of the diamine (B1) include aromatic diamines (such as phenylenediamine, diethyltoluenediamine, and 4,4'-diaminodiphenylmethane); alicyclic diamines (such as 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminecyclohexane, and isophoronediamine); and aliphatic diamines (such as ethylenediamine, tetramethylenediamine, and hexamethylenediamine).
Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine.
Examples of the amino alcohol (B3) include ethanolamine and hydroxyethylaniline.
Examples of the amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.
Examples of compounds (B6) in which the amino group of B1 to B5 has been blocked include ketimine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) and oxazoline compounds.
Among these amines (B), preferred are B1 and a mixture of B1 with a small amount of B2.

Furthermore, if necessary, a terminator can be used to adjust the molecular weight of the modified polyester after the crosslinking and/or elongation reaction is completed. Examples of terminators include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.) and blocked monoamines (ketimine compounds).

The ratio of amines (B), expressed as the equivalent ratio [NCO]/[NHx] of the isocyanate groups [NCO] in the isocyanate group-containing prepolymer (A) to the amino groups [NHx] in the amines (B), is typically 1/2 to 2/1, preferably 1.5/1 to 1/1.5, and more preferably 1.2/1 to 1/1.2. If [NCO]/[NHx] is greater than 2 or less than 1/2, the molecular weight of the urea-modified polyester (i) will be low, resulting in poor hot offset resistance.

---Unmodified polyester resin---
It is important not only to use the modified polyester resin (A) alone, but also to incorporate an unmodified polyester resin (C) as a toner binder component together with the modified polyester resin (A). By using the unmodified polyester resin (C) in combination, low-temperature fixability and gloss and gloss uniformity when used in a full-color device are improved.

Examples of (C) include polycondensates of polyol (1) and polycarboxylic acid (2), which are similar to the polyester component of (A), and the preferred examples are also similar to those of (A). Furthermore, (C) may be not only an unmodified polyester, but also one modified with a chemical bond other than a urea bond, for example, one modified with a urethane bond.
It is preferable that (A) and (C) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, it is preferable that the polyester component of (A) and (C) have similar compositions. When (A) is contained, the mass ratio of (A) to (C) is usually 5/95 to 75/25, preferably 10/90 to 25/75, more preferably 12/88 to 25/75, and particularly preferably 12/88 to 22/78. When the weight ratio of (A) is 5% or more, hot offset resistance can be improved, which is advantageous in terms of achieving both high-temperature storage stability and low-temperature fixability.

The peak molecular weight of (C) is, for example, typically 1,000 or more and 30,000 or less, preferably 1,500 or more and 10,000 or less, and more preferably 2,000 or more and 8,000 or less. A molecular weight of 1,000 or more can improve heat-resistant storage stability, while a molecular weight of 10,000 or less can improve low-temperature fixability.

The hydroxyl value of (C) is preferably 5 mgKOH/g or more, more preferably 10 mgKOH/g or more and 120 mgKOH/g or less, and particularly preferably 20 mgKOH/g or more and 80 mgKOH/g or more. A hydroxyl value of 5 mgKOH/g or more is advantageous in terms of achieving both high-temperature storage stability and low-temperature fixability.

The acid value of (C) is, for example, usually 0.5 mgKOH/g to 40 mgKOH/g, preferably 5 mgKOH/g to 35 mgKOH/g. By having an acid value, the toner tends to be negatively charged.
Furthermore, if the acid value and hydroxyl value exceed these ranges, the toner is susceptible to environmental influences, such as high temperature and high humidity, or low temperature and low humidity, and is likely to cause deterioration of images.

Toner binders (binding resins) are required to have different physical properties for full color and monochrome, and the resin designs are also different.
That is, in the case of full-color printing, a high-gloss image is required, so a low-viscosity binder is necessary, but in the case of monochrome printing, gloss is not particularly necessary and hot offset resistance is important, so a highly elastic binder is necessary.
In the case of a full-color resin, the temperature TE at which the complex viscosity becomes 100 Pa·S is preferably 90 to 170°C, more preferably 100 to 165°C, and particularly preferably 105 to 150°C.
At temperatures below 170°C, sufficient gloss is obtained, and at temperatures above 90°C, good heat-resistant storage stability is achieved.
The temperature TE at which the complex viscosity becomes 100 Pa S can be determined by, for example, melt-kneading a resin using a Labo Plastomill at 130°C and 70 rpm for 30 minutes, measuring the complex viscosity (η*) of the block while changing the resin temperature using a commercially available dynamic viscoelasticity measuring device, and measuring the shear strain that changes periodically with time, and then calculating the complex viscosity (η*) from the following equation (consisting of a real part and an imaginary part):
η*(ω)={(G”(ω)/ω)−i(G'(ω)/ω)}dγ/dt
[In the formula, G"(ω) is the shear loss modulus, G'(ω) is the shear storage modulus, ω is the angular frequency, ω = 2πf (f is the frequency), and γ is the amount of strain.] It is determined from the temperature at which the real part becomes 100 Pa S.

Furthermore, from the viewpoint of glossiness, the THF-insoluble content of full-color resins is preferably 10% or less, and more preferably 5% or less.

The THF-insoluble matter and the THF-soluble matter can be obtained by the following method.
[Method for measuring THF-insoluble and THF-soluble content]
Approximately 0.5 g of a sample is accurately weighed into a 200 ml Mayer flask equipped with a stopper, 50 ml of THF is added, and the mixture is refluxed with stirring for 3 hours, cooled, and then the insoluble matter is filtered off using a glass filter.
The value (%) of the THF insoluble matter is calculated from the weight ratio of the resin content on the glass filter after drying it under reduced pressure at 80° C. for 3 hours to the weight of the sample.

In the color toner of the present invention, in order to obtain low-temperature fixing, a wide fixing temperature range, and appropriate gloss (glossiness), it is preferable that the number-average molecular weight Mn of the resin in the toner is 2,000 or more and 7,000 or less, and the weight-average molecular weight Mw is 10,000 or more and 70,000 or less.
That is, it is desirable that the number average molecular weight Mn of the THF soluble portion of the toner is 2,000 or more and 7,000 or less, and the weight average molecular weight Mw is 10,000 or more and 70,000 or less.
Furthermore, in order to obtain a vivid full-color image, it is preferable to increase the glossiness, and it is more preferable that the number average molecular weight Mn is 2,000 or more and 5,000 or less, and the weight average molecular weight Mw is 10,000 or more and 30,000 or less.

The gloss level for obtaining a vivid full-color image is preferably 5% or more and 95% or less.
By creating such a high-gloss image, the toner is completely fused, allowing light to pass through the toner layer on the image and be reflected back by the paper substrate, resulting in vivid colors.

The binder resin is preferably a polyester resin.
In the present invention, since gloss is required for the image, the molecular weight of the binder resin is relatively small. In the case of polyester resin, even if the molecular weight is small, resin strength can be easily obtained, and the toner is less likely to be pulverized or aggregated during toner agitation, which is more advantageous than general vinyl polymer resins for toner.

The glass transition temperature (Tg) of the toner is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 40°C or higher and 70°C or lower, and more preferably 45°C or higher and 55°C or lower.

<<Coloring Agents>>
As the colorant, all known dyes and pigments can be used, for example, 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), Balkan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, anthrazan yellow BGL, isoindolinone yellow, red iron oxide, red lead, vermilion lead , Cadmium Red, Cadmium Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Faise Red, Parachlor Orthonitroaniline Red, Lithol 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, Lithol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Bordeaux 5B, Toluidine Maroo 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, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkali Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue , fast sky blue, indanthrene blue (RS, BC), indigo, ultramarine, Prussian 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, anthraquinone green, titanium oxide, zinc white, lithopone, and mixtures thereof can be used.

There are no particular restrictions on the colorant content in the toner and it can be selected appropriately depending on the purpose, but it is preferably 1% by weight or more and 15% by weight or less, and more preferably 3% by weight or more and 10% by weight or less, based on the toner.

The colorant can also be used as a masterbatch in which it is combined with a resin.
A masterbatch can be obtained by mixing and kneading a masterbatch resin and a colorant under high shear force. An organic solvent can be used to enhance the interaction between the colorant and the resin. A method known as the flushing method, in which an aqueous paste containing the colorant in water is mixed and kneaded with the resin and organic solvent, and the colorant is transferred to the resin, and the water and organic solvent components are then removed, is also preferred because the wet cake of the colorant can be used as is, eliminating the need for drying. A high-shear dispersing device such as a three-roll mill is preferably used for mixing and kneading.
The amount of the masterbatch used is preferably 0.1 to 20 parts by mass per 100 parts by mass of the binder resin.
The resin for preparing the masterbatch preferably has an acid value of 30 mgKOH/g or less and an amine value of 1 to 100, and is used with a colorant dispersed therein; more preferably has an acid value of 20 mgKOH/g or less and an amine value of 10 to 50, and is used with a colorant dispersed therein.
If the acid value exceeds 30 mgKOH/g, the chargeability under high humidity conditions may decrease and the pigment dispersibility may become insufficient.
Furthermore, when the amine value is less than 1 or exceeds 100, the pigment dispersibility may also be insufficient.
The acid value can be measured by the method described in JIS K0070, and the amine value can be measured by the method described in JIS K7237.

A dispersant may also be used to improve the dispersibility of the pigment.
From the viewpoint of pigment dispersibility, the dispersant preferably has high compatibility with the binder resin. Specific examples of commercially available dispersants include "Ajisper PB821" and "Ajisper PB822" (manufactured by Ajinomoto Fine-Techno Co., Ltd.), "Disperbyk-2001" (manufactured by BYK-Chemie), and "EFKA-4010" (manufactured by EFKA).
The mass average molecular weight of the dispersant is preferably 500 to 100,000, and more preferably 3,000 to 100,000 from the viewpoint of pigment dispersibility, as determined by gel permeation chromatography using a styrene-equivalent molecular weight at the maximum value of the main peak.
In particular, 5,000 to 50,000 is preferred, and 5,000 to 30,000 is most preferred.
If the molecular weight is less than 500, the polarity becomes high and the dispersibility of the colorant may decrease, whereas if the molecular weight exceeds 100,000, the affinity with the solvent becomes high and the dispersibility of the colorant may decrease.

The dispersant is preferably blended in the toner in an amount of 0.1 to 10% by mass relative to the colorant.
If the blending ratio is less than 0.1% by mass, the pigment dispersibility may be insufficient, and if it is more than 10% by mass, the chargeability under high humidity conditions may decrease.

<<Charge control agent>>
The toner may contain a charge control agent as needed.
Any known charge control agent can be used. However, for color toners, white or light-colored ones are preferred. Colored charge control agents tend to mix with the toner, making it dull, so the content must be kept low.
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, phosphorus simple substance or compounds, tungsten simple substance or compounds, fluorine-based activators, metal salicylate, and metal salts of salicylic acid derivatives.
Specifically, these include the nigrosine dye Bontron 03, the quaternary ammonium salt Bontron P-51, the metal-containing azo dye Bontron S-34, the oxynaphthoic acid metal complex E-82, the salicylic acid metal complex E-84, and the phenol condensate E-89 (all manufactured by Orient Chemical Industry Co., Ltd.), the quaternary ammonium salt molybdenum complexes TP-302 and TP-415 (both manufactured by Hodogaya Chemical Co., Ltd.), the quaternary ammonium salt Copy Charge PSY VP2038, the triphenylmethane derivative Copy Blue PR, and the quaternary ammonium salts Copy Charge NEG VP2036 and Copy Charge NX. Examples of suitable pigments include VP434 (manufactured by Hoechst), LRA-901, a boron complex LR-147 (manufactured by Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone, azo pigments, and other polymeric compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.

In the present invention, the amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as needed, and the toner production method, including the dispersion method, and is not uniquely limited, but is preferably used in the range of 0.1 to 10 parts by mass per 100 parts by mass of binder resin. A range of 0.2 to 5 parts by mass is more preferable. If the amount exceeds 10 parts by mass, the toner will have too high a chargeability, which will reduce the effect of the main charge control agent and increase the electrostatic attraction force with the developing roller, resulting in a decrease in the fluidity of the developer and a decrease in image density.
These charge control agents and release agents can be melt-kneaded together with the master batch and resin.

<<External additives>>
In order to improve the fluidity, storage stability, developability, transferability, and durability of the toner, inorganic fine particles such as oxide fine particles and hydrophobic silica fine powder, or polymeric resin fine particles may be added and mixed with the toner base particles as external additives.
This effect is achieved by covering the wax, which reduces transferability and durability, with these external additives and by reducing the contact area by covering the toner surface with fine particles.
It is preferable that the surfaces of these inorganic fine particles are hydrophobized, and metal oxide fine particles such as hydrophobized silica or titanium oxide are preferably used.
By increasing the amount of hydrophobic treated titanium oxide added externally compared to the amount of hydrophobic treated silica added externally, the toner can be made to have excellent charging stability against humidity, improved toner transfer rate, and good filming resistance.

The inorganic fine particles and resin fine particles preferably have an average primary particle size of 5 nm to 2 μm.
The proportion of inorganic fine particles used varies depending on the type, but is generally in the range of 0.01 to 5% by mass based on the toner particles.
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, penguin, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
These may be used singly or in combination of two or more.
Examples of polymeric resin particles include polymer particles made of polystyrene, methacrylate ester or acrylate ester copolymers, silicone, benzoguanamine, nylon, or other polycondensation systems, and thermosetting resins obtained by soap-free emulsion polymerization, suspension polymerization, or dispersion polymerization.
Among these, when a glycerin fatty acid ester or a polyglycerin fatty acid ester is used in combination with the ketone wax as the release agent, it is preferable to use silica and titanium oxide in combination.
Silica and titanium oxide have a strong negative chargeability, and can change positively chargeable particles to negatively chargeable particles without the use of external additives.
Particularly suitable additives include silica, titania, titanium oxide, and alumina fine particles that have been hydrophobized with a hydrophobic treatment agent.
Representative examples of the hydrophobic treatment agent include the following.
Dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, allyldimethyldichlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, p-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, chloromethyltrichlorosilane, p-chlorophenyltrichlorosilane, 3-chloropropyltrichlorosilane, 3-chloropropyltrimethoxysilane, vinyltriethoxysilane, vinylmethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinyldichlorosilane, dimethylvinylchlorosilane, octyltrichlorosilane, decyltrichlorosilane, nonyltrichlorosilane, (4-t-propylphenyl)trichlorosilane, (4-t-butylphenyl)trichlorosilane (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, 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, hexatlyldisilazane, and the like.
In addition, titanate-based coupling agents and aluminum-based coupling agents can also be used.

A general powder mixer is used to mix the above external additives, but it is preferable to equip it with a jacket or the like so that the internal temperature can be adjusted.
For example, a V-type mixer, a rocking mixer, a Loedige mixer, a Nauta mixer, a Henschel mixer, etc. are preferably used.

By incorporating the inorganic fine particles or resin fine particles into the toner (internal addition), the effect is less than when they are added externally, but the effect of improving transferability and durability can be obtained and the grindability of the toner can be improved.
Furthermore, by using both external and internal addition, it is possible to prevent the externally added fine particles from being embedded, so that excellent transferability can be stably obtained and durability is also improved.

There are no particular restrictions on the amount of external additive added and it can be selected appropriately depending on the purpose, but it is preferably 0.1% by weight or more and 5% by weight or less, and more preferably 0.3% by weight or more and 3% by weight or less, based on the toner.

Examples of cleaning improvers for removing residual developer remaining on the photoreceptor or primary transfer medium after transfer include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, and polymer microparticles manufactured by soap-free emulsion polymerization, such as polymethyl methacrylate microparticles and polystyrene microparticles. Polymer microparticles with a relatively narrow particle size distribution and a volume average particle size of 0.01 μm or more and 1 μm or less are preferred.

<Other ingredients>
The other components are not particularly limited and can be appropriately selected depending on the purpose.
Examples of the other components include a flowability improver, a cleaning property improver, a magnetic material, and a metal soap.
The flow improver refers to a material that is surface-treated to increase hydrophobicity and can prevent deterioration of flow characteristics and charging characteristics even under high humidity conditions, and examples thereof include silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate-based coupling agents, aluminum-based coupling agents, silicone oils, and modified silicone oils.
The cleaning property improver is added to the toner in order to remove the developer remaining on the electrostatic latent image carrier or the intermediate transfer body after transfer, and examples thereof include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles, and the like.
The polymer particles preferably have a relatively narrow particle size distribution, and the weight average particle size is preferably 0.01 to 1 μm.
The magnetic material is not particularly limited and can be appropriately selected from known materials depending on the purpose, and examples thereof include iron powder, magnetite, and ferrite.
Among these, white is preferred in terms of color tone.

[Toner manufacturing method]
The method for producing the toner in the present invention is not particularly limited, and the toner can be produced by a melt-kneading pulverization method and a polymerization method, a polyaddition reaction method using an isocyanate group-containing prepolymer, a method of dissolving in a solvent and removing the solvent followed by pulverization, or a melt spray method.
For example, a melt kneading method, a polymerization method (suspension polymerization method/emulsion polymerization method) in which a monomer composition containing a specific crystalline polymer and a polymerizable monomer is directly polymerized in an aqueous phase, a polyaddition reaction method in which a composition containing a specific crystalline polymer and an isocyanate group-containing prepolymer is directly elongated/crosslinked with amines in an aqueous phase, and a method in which the material is dissolved in a solvent, desolvated, and then pulverized can be used.
As mentioned above, in the present invention, binder resins whose main component is polyester resin are preferably used.
In the melt-kneading pulverization method, as an apparatus for melting and kneading the toner, a batch type two-roll mixer, a Banbury mixer, a continuous twin-screw extruder, for example, a KTK type twin-screw extruder manufactured by Kobe Steel, Ltd., a TEM type twin-screw extruder manufactured by Toshiba Machine Co., Ltd., a twin-screw extruder manufactured by KCK Corporation, a PCM type twin-screw extruder manufactured by Ikegai Iron Works, a KEX type twin-screw extruder manufactured by Kurimoto Iron Works, or a continuous single-screw kneader, for example, a Ko-Kneader manufactured by Buss, can be suitably used.
In the above-mentioned polymerization method and polyaddition reaction method using an isocyanate group-containing prepolymer, it is essential to apply mechanical energy to the aqueous phase to forcibly emulsify (form droplets).
Examples of the means for applying such mechanical energy include means for applying strong stirring or ultrasonic vibration energy such as a homomixer, ultrasonic wave, or Manton-Gaulin.
For pulverization, a hammer mill, a rotoplex, or the like may be used to roughly pulverize the material, and then a fine pulverizer using a jet stream or a mechanical fine pulverizer may be used, and it is desirable to carry out the pulverization so that the average particle size becomes 3 to 15 μm.

The pulverized material is then adjusted to a particle size of 5 to 20 μm using an air classifier or the like.
The softening temperature (T _1/2 : the temperature at which half of the sample flows out under a given load at elevated temperature) of the toner determined by a flow tester is preferably 115 to 140°C.
From the viewpoint of toner storage stability, the glass transition temperature (Tg) is preferably 55 to 70°C, and more preferably 57 to 70°C.
If the Tg is lower than 55° C., the toner is likely to deteriorate in a high-temperature atmosphere, and offset may easily occur during fixing.
If the Tg exceeds 70° C., the fixability may decrease.
The external additive is added to the toner matrix by mixing and stirring the toner matrix and the external additive using a mixer, so that the external additive is crushed and coated on the toner surface.
At this time, it is important from the viewpoint of durability that the external additives such as inorganic fine particles and resin fine particles adhere uniformly and firmly to the toner matrix.

The shape, size, etc. of the toner of the present invention are not particularly limited and can be selected appropriately depending on the purpose.

(Developer)
The developer using the toner of the present invention may be either a one-component developer or a two-component developer. For example, a two-component developer contains the toner of the present invention and a carrier.
The carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably one having a core material and a resin layer covering the core material.
The material for the core material is not particularly limited and can be appropriately selected depending on the purpose. For example, manganese-strontium (Mn—Sr)-based materials and manganese-magnesium (Mn—Mg)-based materials having a repulsion coefficient of 50 emu/g to 90 emu/g are preferred. From the viewpoint of ensuring image density, highly magnetic materials such as iron powder (100 emu/g or more) and magnetite (75 emu/g to 120 emu/g) are preferred. Furthermore, weakly magnetic materials such as copper-zinc (Cu—Zn)-based materials (30 emu/g to 80 emu/g) are preferred, as they can weaken the contact of the toner with the photoreceptor in a spiked state, which is advantageous for achieving high image quality. These materials may be used alone or in combination of two or more.
The volume average particle diameter of the core material is preferably 25 μm or more and 200 μm or less.
The material for the resin layer is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof 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 an acrylic monomer, copolymers of vinylidene fluoride and vinyl fluoride, fluoro terpolymers such as terpolymers of tetrafluoroethylene, vinylidene fluoride and a non-fluorinated monomer, silicone resins, etc. These may be used alone or in combination of two or more.
The mixture ratio of the toner and the carrier in the two-component developer is preferably 2.0% by mass to 12.0% by mass, more preferably 2.5% by mass to 10.0% by mass.

(Toner storage unit)
The toner storage unit in the present invention refers to a unit having a function of storing the toner of the present invention, and storing the toner in the unit. Examples of the toner storage unit include a toner storage container, a developing unit, and a process cartridge.
The toner container refers to a container that stores toner.
The developing device is a device that contains toner and has means for developing.
The process cartridge is a device that integrates at least an image carrier and a developing means, contains toner, and is detachably mountable to 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.
The toner storage unit of the present invention stores the toner of the present invention.
By mounting the toner storage unit of the present invention in an image forming apparatus and forming an image using the toner of the present invention, an excellent image can be obtained with excellent low-temperature fixability and heat-resistant storage stability.

(Process cartridge)
The process cartridge according to the present invention 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 with toner to form a visible image, and may further comprise other means, such as a charging means, an exposing means, a developing means, a transferring means, a cleaning means, and a discharging means, which are appropriately selected as necessary.
The developing means comprises at least a developer container that contains the toner or developer of the present invention, and a developer carrier that carries and transports the toner or developer contained in the developer container, and may further comprise a layer thickness regulating member for regulating the thickness of the toner layer to be carried.
The process cartridge according to the present invention can be detachably mounted in various electrophotographic apparatuses, facsimiles, and printers, and is preferably detachably mounted in the image forming apparatus of the present invention described below.

(Image forming method and image forming apparatus)
The image forming method of the present invention 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 with toner to form a toner image, a transfer step of transferring the toner image formed on the electrostatic latent image carrier to the surface of a recording medium, and a fixing step of fixing the toner image transferred to the surface of the recording medium, and may further include other steps such as a discharging step, a cleaning step, a recycling step, and a control step, as necessary.
The image forming apparatus of the present invention comprises an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, developing means for developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image, transfer means for transferring the toner image formed on the electrostatic latent image carrier to the surface of a recording medium, and fixing means for fixing the toner image transferred to the surface of the recording medium, and may further comprise other means such as a discharging means, a cleaning means, a recycling means, and a control means, as necessary.
The toner in the image forming method and image forming apparatus of the present invention is the toner of the present invention.

<Electrostatic Latent Image Forming Process and Electrostatic Latent Image Forming Unit>
The electrostatic latent image forming step is a step of forming an electrostatic latent image on an electrostatic latent image bearing member.
The electrostatic latent image carrier (hereinafter sometimes referred to as "electrophotographic photoreceptor" or "photoreceptor") is not particularly limited in terms of material, shape, structure, size, etc., and can be appropriately selected from known ones, but a drum shape is preferred as its shape, and examples of its material 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 because they can produce higher resolution images.
The electrostatic latent image can be formed by, for example, uniformly charging the surface of the electrostatic latent image bearing member and then exposing it to light in an imagewise manner, and can be formed by an electrostatic latent image forming unit.
The electrostatic latent image forming means includes, for example, at least a charging means (charger) that uniformly charges the surface of the electrostatic latent image carrier, and an exposure means (exposure device) that imagewise exposes the surface of the electrostatic latent image carrier.
The charging can be carried out, for example, by applying a voltage to the surface of the electrostatic latent image bearing member using the charger.
The charger is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a known contact charger equipped with a conductive or semiconductive roll, brush, film, rubber blade, etc., and a non-contact charger utilizing corona discharge such as a corotron or scorotron.
The charger is preferably one that is disposed in contact with or not in contact with the electrostatic latent image bearing member and charges the surface of the electrostatic latent image bearing member by applying DC and AC voltages in a superimposed manner.
It is also preferred that the charger is a charging roller disposed close to the electrostatic latent image carrier without contacting the electrostatic latent image carrier via a gap tape, and that the surface of the electrostatic latent image carrier is charged by applying a DC voltage and an AC voltage superimposed on the charging roller.
The exposure can be carried out, for example, by exposing the surface of the electrostatic latent image bearing member to light in an imagewise manner using the exposure unit.
The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger in the form of an image to be formed, and can be appropriately selected depending on the purpose. Examples of the exposure device include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.
In the present invention, a backlight system may be employed in which exposure is performed imagewise from the back side of the electrostatic latent image bearing member.

<Developing step and developing means>
The developing step is a step of developing the electrostatic latent image with the toner to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image with the toner, and can be formed by the developing unit.
The developing means preferably includes at least a developing device that contains the toner and can apply the toner to the electrostatic latent image in a contact or non-contact manner, and more preferably includes a developing device that includes a toner container.
The developing device may be a single-color developing device or a multi-color developing device, and a suitable example is one having an agitator that charges the toner by frictional agitation and a rotatable magnetic roller.

<Transfer Process and Transfer Means>
The transfer step is a step of transferring the visible image onto a recording medium. A preferred embodiment is one in which an intermediate transfer body is used, the visible image is primarily transferred onto the intermediate transfer body, and then the visible image is secondarily transferred onto the recording medium. A more preferred embodiment is one in which two or more colors, preferably full-color toner, are used as the toner, and the transfer step includes a primary transfer step in which the visible image is transferred onto the intermediate transfer body to form a composite transfer image, and a secondary transfer-fixing step in which the composite transfer image is transferred onto a recording medium.
The transfer means (the primary transfer means and the secondary transfer means) preferably includes at least a transfer device that peels and charges the visible image formed on the electrostatic latent image carrier (photosensitive member) onto the recording medium. The number of transfer means may be one or more.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

<Fixing process and fixing means>
The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed for each color developer each time it is transferred to the recording medium, or may be performed simultaneously for each color developer in a stacked state.
The fixing device is not particularly limited and can be appropriately selected depending on the purpose, but known heating and pressurizing means are suitable. Examples of the heating and pressurizing means include a combination of a heating roller and a pressure roller, and a combination of a heating roller, a pressure roller and an endless belt.

<Static Charge Elimination Process and Means>
The charge removal step is a step of removing electricity by applying a charge removal bias to the electrostatic latent image bearing member, and can be suitably performed by a charge removal unit.
The discharging means is not particularly limited as long as it can apply a discharging bias to the electrostatic latent image bearing member, and can be appropriately selected from known discharging devices, and a suitable example is a discharging lamp.

<Cleaning Process and Cleaning Means>
The cleaning step is a step of removing the toner remaining on the electrostatic latent image bearing member, and can be suitably carried out by a cleaning means.
The cleaning means is not particularly limited as long as it can remove the toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Suitable examples include magnetic brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, and web cleaners.

<Recycling process and recycling means>
The recycling step is a step of recycling the toner removed in the cleaning step to the developing unit, and can be suitably performed by a recycling means. The recycling means is not particularly limited, and examples thereof include known transport means.

<Control process and control means>
The control step is a step of controlling each of the steps, and each step can be suitably carried out by a control means.
The control means is not particularly limited as long as it can control the movement of each of the means, and can be appropriately selected depending on the purpose. Examples of the control means include devices such as a sequencer and a computer.

FIG. 1 is a schematic explanatory view showing an example of an image forming apparatus of the present invention.
The image forming apparatus 100A includes a photosensitive drum 10, a charging roller 20, an exposure device, a developing device 40, an intermediate transfer belt 50, a cleaning device 60 having a cleaning blade, and a discharging lamp 70.
The intermediate transfer belt 50 is an endless belt stretched by three rollers 51 arranged 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 that can apply a transfer bias (primary transfer bias) to the intermediate transfer belt 50. A cleaning device 90 having a cleaning blade is arranged near the intermediate transfer belt 50. Furthermore, a transfer roller 80 that can apply a transfer bias (secondary transfer bias) to transfer a toner image onto transfer paper 95 is arranged opposite the intermediate transfer belt 50.
In addition, a corona charging device 58 for applying an electric charge to the toner image transferred to the intermediate transfer belt 50 is arranged around the intermediate transfer belt 50, between the contact point between the photosensitive drum 10 and the intermediate transfer belt 50 and the contact point between the intermediate transfer belt 50 and the transfer paper 95, in the direction of rotation of the intermediate transfer belt 50.
The developing device 40 is composed 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 arranged around the developing belt 41. Each developing unit 45 includes a developer container 42, a developer supply roller 43, and a developing roller (developer carrier) 44. The developing belt 41 is an endless belt stretched over multiple belt rollers and can move in the direction of the arrow in FIG. 1. A portion of the developing belt 41 contacts the photosensitive drum 10.

Next, a method for forming an image using the image forming apparatus 100A will be described.
First, the surface of the photosensitive drum 10 is uniformly charged using the charging roller 20, and then an exposure device (not shown) exposes the photosensitive drum 10 to exposure light L to form an electrostatic latent image. Next, the electrostatic latent image formed on the photosensitive drum 10 is developed with toner supplied from the developing device 40 to form a toner image. The toner image formed on the photosensitive drum 10 is then transferred (primary transfer) onto the intermediate transfer belt 50 by a transfer bias applied from the roller 51, and then transferred (secondary transfer) onto the transfer paper 95 by a transfer bias applied from the transfer roller 80. Meanwhile, the photosensitive drum 10 from which the toner image has been transferred onto the intermediate transfer belt 50 has residual toner removed by the cleaning device 60, and is then discharged by the discharge lamp 70.

Figure 2 shows a second example of an image forming apparatus used in the present invention. Image forming apparatus 100B has the same configuration as image forming apparatus 100A, except that it does not have a development belt 41 and instead has a black development unit 45K, a yellow development unit 45Y, a magenta development unit 45M, and a cyan development unit 45C arranged directly opposite each other around the photosensitive drum 10.

3 shows a third example of an image forming apparatus used in the present invention. Image forming apparatus 100C is a tandem color image forming apparatus, and includes a copying machine main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.
Intermediate transfer belt 50, located in the center of copying machine main body 150, is an endless belt stretched over three rollers 14, 15, and 16, and can move in the direction of the arrow in Fig. 3. Near roller 15, there is disposed cleaning device 17 having a cleaning blade for removing toner remaining on intermediate transfer belt 50 after the toner image has been transferred onto recording paper.
An exposure device 21 is disposed near the image forming unit 120. A secondary transfer belt 24 is disposed on the side of the intermediate transfer belt 50 opposite to the side where the image forming unit 120 is disposed. The secondary transfer belt 24 is an endless belt stretched over a pair of rollers 23, and the recording paper transported on the secondary transfer belt 24 and the intermediate transfer belt 50 can come into contact with each other between the rollers 16 and 23.
Also, near the secondary transfer belt 24 is disposed a fixing device 25 that includes a fixing belt 26, which is an endless belt stretched over a pair of rollers, and a pressure roller 27 that is positioned so as to be pressed against the fixing belt 26. Also, near the secondary transfer belt 24 and the fixing device 25 is disposed a sheet inverting device 28 for inverting the recording paper when forming images on both sides of the recording paper.

Next, a method for forming a full-color image using the image forming apparatus 100C will be described.
First, a color original is placed on the platen 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and a color original is placed on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed.
When the start switch is pressed, if an original is set on the automatic document feeder 400, the original is transported and moved onto the contact glass 32, and, on the other hand, if the original is set on the contact glass 32, the scanner 300 is driven, and the first traveling body 33 equipped with a light source and the second traveling body 34 equipped with a mirror travel immediately. At this time, light irradiated from the first traveling body 33 is reflected from the surface of the original, reflected by the second traveling body 34, and then received by the reading sensor 36 via the imaging lens 35, thereby reading the original and obtaining image information of black, yellow, magenta, and cyan.

The image information for each color is transmitted to the image forming means 18 in the image forming unit 120 for each color, and a toner image for that color is formed. As shown in Figure 4, each image forming unit 120 for each color includes a photosensitive drum 10, a charging roller 160 that uniformly charges the photosensitive drum 10, an exposure device that exposes the photosensitive drum 10 to exposure light L based on the image information for that color to form an electrostatic latent image for that color, a developing device 61 that develops the electrostatic latent image with a developer for that color to form a toner image for that color, a transfer roller 62 that transfers the toner image onto the intermediate transfer belt 50, a cleaning device 63 having a cleaning blade, and a discharging lamp 64.
The toner images of each color formed by the image forming units 120 of each color are transferred sequentially (primary transfer) onto the intermediate transfer belt 50 which is stretched and moves around rollers 14, 15 and 16, and are superimposed to form a composite toner image.
On the other hand, 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 provided in multiple stages in the paper bank 143, which is separated one sheet at a time by the separation roller 145 and sent to the paper feed path 146, and then conveyed by the conveyance roller 147 and guided to the paper feed path 148 in the copying machine main body 150, where it is stopped by striking against the registration roller 49. Alternatively, the paper feed roller is rotated to feed recording paper from the manual feed tray 54, which is separated one sheet at a time by the separation roller 52 and guided to the manual feed path 53, where it is stopped by striking against the registration roller 49.
The registration roller 49 is generally grounded when in use, but may be used with a bias applied to it in order to remove paper dust from the recording paper.
Next, the registration roller 49 is rotated in synchronization with the composite toner image formed on the intermediate transfer belt 50, thereby feeding the recording paper between the intermediate transfer belt 50 and the secondary transfer belt 24, and the composite toner image is transferred (secondary transfer) onto the recording paper. Any toner remaining on the intermediate transfer belt 50 after the composite toner image has been transferred is removed by the cleaning device 17.
The recording paper onto which the composite toner image has been transferred is transported by secondary transfer belt 24, and then the composite toner image is fixed by fixing device 25. Next, the transport path of the recording paper is switched by switching claw 55, and the recording paper is discharged onto paper discharge tray 57 by discharge rollers 56. Alternatively, the transport path of the recording paper is switched by switching claw 55, the sheet is reversed by sheet reversing device 28, an image is formed on the back side in the same manner, and then the recording paper is discharged onto paper discharge tray 57 by discharge rollers 56.
According to the image forming apparatus and image forming method of the present invention, the toner of the present invention, which has excellent low-temperature fixability and heat-resistant storage stability, is used, and therefore high-quality images can be provided for a long period of time.

(Method for manufacturing printed matter)
The method for producing a printed matter of the present invention includes a step of forming a toner image on a recording medium using the toner of the present invention, and further includes other steps as necessary.
The recording medium is not particularly limited and can be appropriately selected depending on the purpose.
The step of forming the toner image on the recording medium is the same as that of the image forming method of the present invention.

The following describes examples of the present invention, but the present invention is not limited to these examples. Note that in the examples, "parts by mass" may be expressed as "parts."

[Production of release agent containing ketone compound (ketone wax)]
(Production Example 1)
<Production of Ketone Wax 1>
Palmitic acid (1.0 mol) and magnesium oxide (0.5 mol) were charged into a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet tube, and the mixture was heated to 250°C under a nitrogen atmosphere and reacted for 8 hours. The mixture was then heated to 350°C and the reaction continued for another 8 hours. The mixture was cooled to 120°C and excess magnesium oxide was removed, producing Ketone Wax 1. The acid value was 1.8 mgKOH/g and the melting point was 83°C.

(Production Example 2)
<Production of Ketone Wax 2>
Ketone wax 2 was produced in the same manner as in Production Example 1, except that the acid used in Production Example 1 was changed to stearic acid. The acid value was 1.9 mg KOH/g and the melting point was 92°C.

(Production Example 3)
<Production of Ketone Wax 3>
Ketone wax 3 was produced in the same manner as in Production Example 1, except that the acid used in Production Example 1 was changed to tridecylic acid. The acid value was 2.1 mg KOH/g and the melting point was 78°C.

(Production Example 4)
<Production of Ketone Wax 4>
Ketone wax 4 was produced in the same manner as in Production Example 1, except that the acid used in Production Example 1 was changed to behenic acid. The acid value was 2.0 mgKOH/g and the melting point was 97°C.

(Production Example 5)
<Production of Ketone Wax 5>
Ketone wax 5 was produced in the same manner as in Production Example 1, except that the reaction time at 250°C was changed to 10 hours. The acid value was 0.8 mgKOH/g and the melting point was 83°C.

(Production Example 6)
<Production of Ketone Wax 6>
Ketone wax 6 was produced in the same manner as in Production Example 1, except that the reaction time at 250°C was changed to 5 hours. The acid value was 4.8 mgKOH/g and the melting point was 83°C.

(Production Example 7)
<Production of Ketone Wax 7>
Ketone wax 7 was produced in the same manner as in Production Example 1, except that after removing magnesium oxide, 2.0 g of an adsorbent (Kyoward 600S, manufactured by Kyowa Chemical Industry Co., Ltd.) was added and treated for 1 hour. The acid value was 0.5 mg KOH/g and the melting point was 83°C.

(Production Example 8)
<Production of Ketone Wax 8>
Ketone wax 8 was produced in the same manner as in Production Example 1, except that the reaction time at 250°C was changed to 12 hours. The acid value was 0.5 mgKOH/g and the melting point was 83°C.

[Production of amorphous polyester resin]
The monomer species (acid components) and tetrabutoxy titanate as a condensation catalyst shown in Table 2 below were placed in a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet tube, and reacted at 230°C for 6 hours under a nitrogen stream while distilling off the water produced. Next, the reaction was continued for 1 hour under a reduced pressure of 5 mmHg to 20 mmHg, to obtain the amorphous polyester resins used in the examples.
In Table 2, the "25 mol %" shown for bisphenol A (2,2) propylene oxide indicates the proportion in the alcohol component when the acid component and the alcohol component are 50 mol %.

[Production of crystalline polyester resin]
Fumaric acid and 1,6-hexanediol were charged into a 5 L four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple so that the OH/COOH ratio of the mixture was 0.9, and reacted together with titanium tetraisopropoxide (500 ppm relative to the resin component) at 180°C for 10 hours. The mixture was then heated to 200°C and reacted for 3 hours, and further reacted at a pressure of 8.3 kPa for 2 hours to obtain a crystalline polyester used in the examples.

Example 1
-Preparation of Toner Base Particles 1-
The formulations in Table 3 below were premixed using a Henschel mixer (FM20B, manufactured by Mitsui Miike Chemical Engineering Co., Ltd.), and then melted and kneaded at 120°C in a twin-screw kneader (PCM-30, manufactured by Ikegai Corporation).
The resulting kneaded product was rolled to a thickness of 2.7 mm using a roller, cooled to room temperature using a belt cooler, and coarsely pulverized using a hammer mill to a weight average particle size of 200 μm to 300 μm.
Next, the mixture was finely pulverized using a supersonic jet pulverizer, Labojet (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), and then classified using an air classifier (manufactured by Nippon Pneumatic Mfg. Co., Ltd., MDS-I) while appropriately adjusting the louver opening so that the weight average particle size would be 5.8±0.2 μm, thereby obtaining toner base particles 1 of Example 1.

Example 2
-Preparation of Toner Base Particles 2-
Toner base particles 2 of Example 2 were obtained in the same manner as in Example 1, except that the release agent used in Example 1 was changed to Ketone wax 2.

Example 3
-Preparation of Toner Base Particles 3-
Toner base particles 3 of Example 3 were obtained in the same manner as in Example 1, except that the styrene-α-methylstyrene copolymer (FTR-2140, manufactured by Mitsui Chemicals, Inc.) was not used.

Example 4
-Preparation of Toner Base Particles 4-
Toner base particles 3 of Example 4 were obtained in the same manner as in Example 1, except that the hydrophobic silica (RY-50, manufactured by Nippon Aerosil Co., Ltd.) was not used.

Example 5
-Preparation of Toner Base Particles 5-
Toner base particles 5 of Example 5 were obtained in the same manner as in Example 1, except that the release agent used in Example 1 was changed to Ketone wax 3.

Example 6
-Preparation of Toner Base Particles 6-
Toner base particles 6 of Example 6 were obtained in the same manner as in Example 1, except that the release agent used in Example 1 was changed to Ketone wax 4.

Example 7
-Preparation of Toner Base Particles 7-
Toner base particles 7 of Example 7 were obtained in the same manner as in Example 1, except that the hydrophobic silica (RY-50 manufactured by Nippon Aerosil Co., Ltd.) in Example 1 was changed to hydrophobic silica (UFP-35 manufactured by Denki Kagaku Kogyo Kabushiki Kaisha).
(Example 8)
-Preparation of Toner Base Particles 8-
Toner base particles 8 of Example 8 were obtained in the same manner as in Example 1, except that the release agent used in Example 1 was changed to Ketone Wax 5.

Example 9
-Preparation of Toner Base Particles 9-
Toner base particles 9 of Example 9 were obtained in the same manner as in Example 1, except that the release agent used in Example 1 was changed to Ketone Wax 6.

(Comparative Example 1)
-Preparation of Toner Base Particles 10-
Toner base particles 10 of Comparative Example 1 were obtained in the same manner as in Example 1, except that the release agent used in Example 1 was changed to WE-11 (ester wax, manufactured by NOF Corporation).

(Comparative Example 2)
-Preparation of Toner Base Particles 11-
Toner base particles 11 of Comparative Example 2 were obtained in the same manner as in Example 1, except that the release agent used in Example 1 was changed to Ketone Wax 7.

(Comparative Example 3)
-Preparation of Toner Base Particles 12-
Toner base particles 12 of Comparative Example 3 were obtained in the same manner as in Example 1, except that the release agent used in Example 1 was changed to Ketone Wax 8.

The toner obtained was subjected to the following procedures: "isolation of polyester," "isolation of release agent (wax)," "measurement of the melting point of release agent (wax)," "measurement of glass transition temperature (Tg)," "presence or absence of hydrophobic silica," "measurement of the average primary particle size of hydrophobic silica," and "confirmation of the presence or absence of α-methylstyrene." The results are shown in Table 3.

[Method for isolating polyester]
100 g of toluene was added to 5 g of toner and left for 24 hours. Thereafter, the mixture was centrifuged at 3,000 rpm using a centrifugal separator (HIMAC CP100NX, manufactured by Hitachi) to precipitate insoluble matter, which was then separated by decantation. The solution components were evaporated to dryness.

[Method for isolating release agent (wax)]
100 g of toluene was added to 5 g of toner and left for 24 hours. Then, a centrifugal separator (HIMAC CP100NX, manufactured by Hitachi) was used to centrifuge at 3,000 rpm to precipitate insoluble matter, which was then separated by decantation. 20 g of chloroform was added to 1 g of the insoluble matter, and the mixture was left for 24 hours. Then, the mixture was centrifuged in the same manner as above to remove the insoluble matter. The solution components were evaporated to dryness.

[Method for measuring the melting point of a release agent (wax)]
Using a differential scanning calorimeter (DSC210, manufactured by Seiko Instruments Inc.), 0.005 g of a sample was weighed into an aluminum pan, heated to 200°C, and cooled from that temperature to 0°C at a rate of 10°C/min. The endothermic peak temperature was measured when the sample was heated at a rate of 10°C/min.

[Method for measuring glass transition temperature (Tg)]
Using a thermal analysis workstation TA-60WS and a differential scanning calorimeter DSC-60 (manufactured by Shimadzu Corporation), the glass transition temperature (Tg) <A (°C)> of the polyester resin alone and the glass transition temperature (Tg) <B (°C)> of the polyester resin containing 10% by mass of the release agent were measured under the conditions shown below.
- Sample conditions -
- Sample container: Aluminum sample pan (with lid)
・Sample amount: 5 mg
Reference: Aluminum sample pan (alumina 10 mg)
Atmosphere: Nitrogen (flow rate 50 ml/min)
- Measurement conditions -
・Start temperature: 0℃
Temperature increase rate: 10°C/min
・Ending temperature: 150℃
Holding time: None Temperature drop: 10°C/min
・Ending temperature: 0℃
Holding time: None Heating rate: 10°C/min
・Ending temperature: 150℃
The measurement results were analyzed using data analysis software TA-60, version 1.52 (manufactured by Shimadzu Corporation). Specifically, first, a range of ±5°C of the maximum peak of the DrDSC curve, which is the DSC differential curve of the second heating, was specified, and the peak temperature was determined using the peak analysis function of the analysis software. Next, a range of ±5°C of the peak temperature was specified on the DSC curve, and the maximum endothermic temperature of the DSC curve was determined using the peak analysis function of the analysis software, and this was taken as the glass transition temperature (Tg).

[Method for confirming the presence or absence of hydrophobic silica and method for measuring the average primary particle diameter of hydrophobic silica]
The toner was embedded in epoxy resin, and the cross section was separated using an ultramicrotome, and the presence or absence of hydrophobic silica was observed by Si mapping using SEM observation and EDS measurement. The observation results for Example 1 are shown in FIG.
The obtained mapping image was then subjected to a binarization process, and the white areas in the image were determined to be regions of hydrophobic silica. The longest diameter in the regions of hydrophobic silica was measured as the primary particle diameter of the hydrophobic silica. Measurements were made on 10 particles, and the average value was calculated.

[Method for checking the presence or absence of α-methylstyrene]
100 g of toluene was added to 5 g of toner and left for 24 hours. Then, a centrifugal separation was performed at 3,000 rpm using a centrifugal separator (HIMAC CP100NX, manufactured by Hitachi) to precipitate insoluble matter, which was then separated by decantation. The solution components were evaporated to dryness and analyzed using GC-MS according to the following procedure, apparatus, and conditions.
-Sample processing-
About 1 μL of a methylating agent (20% methanol solution of tetramethylammonium hydroxide: TMAH) was added dropwise to about 1 mg of the sample to prepare the sample.
- Measurement conditions -
Pyrolysis-Gas Chromatography Mass Spectrometer (Py-GCMS) Analytical Equipment: Shimadzu Corporation, QP2010
・Heating furnace: Frontier Labs Py2020D
・Heating temperature: 320℃
Column: Ultra ALLOY-5L = 30 m I.D = 0.25 mm
Film=0.25μm
Column temperature: 50°C (hold for 1 minute) - temperature increase (10°C/min) - 340°C (hold for 7 minutes)
Split ratio: 1:100
Column flow rate: 1.0 ml/min
Ionization method: EI method (70 eV)
Measurement mode: Scan mode Search data: NIST 20 MASS SPECTRAL LIB.

The commercially available products used in the preparation of the toner base particles are as follows.
Styrene-α-methylstyrene copolymer (Mitsui Chemicals, Inc., FTR-2140)
Carbon black (Mitsubishi Chemical Corporation, #44)
Azo iron compound (T-77, manufactured by Hodogaya Chemical Co., Ltd.)
Hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY-50)
Hydrophobic silica (UFP-35, manufactured by Denki Kagaku Kogyo Co., Ltd.)

Next, a toner developer was prepared using the obtained toner as follows.
The obtained toner developer was evaluated for "low temperature fixability,""heat resistant storage stability,""durability,""blockingprevention," and "UFP (ultra fine particles)" according to the procedures described below.

[Preparation of Toner Developer]
To 100 parts by mass of the toner base particles, 1 part by mass of HDK-2000 (Clariant KK) metal oxide fine particles was added, and the mixture was stirred and mixed in a Henschel mixer to prepare a toner treated with external additives.
5% by weight of this external additive-treated toner and 95% by weight of the coated ferrite carrier were mixed uniformly for 5 minutes at 48 rpm using a Turbler mixer (manufactured by Willy & Bachofen (WAB)) to prepare a toner developer.

[Low temperature fixability]
The obtained toner developer was placed in a Ricoh Co., Ltd. copier (RICOH MPC 6003) and an image was output. A solid image with a deposition amount of 0.4 mg/ ^cm2 was output on paper (Ricoh Co., Ltd. Type 6200) through exposure, development, and transfer processes. The fixing linear speed was 256 mm/sec. The fixing temperature was sequentially changed in 5°C increments, and the lowest temperature at which cold offset did not occur (lower limit fixing temperature: low-temperature fixability) was measured. The NIP width of the fixing device was 11 mm. The measured lower limit temperature (lower limit fixing temperature: low-temperature fixability) was evaluated based on the following evaluation criteria. An evaluation result of "◎" or "◯" was judged to be sufficient performance for practical use.
-Evaluation criteria-
◎: Minimum fixing temperature is less than 120°C. ○: Minimum fixing temperature is 120°C or more and less than 130°C. ×: Minimum fixing temperature is 130°C or more.

[Heat-resistant storage]
The toner base particles were stored for 24 hours under a condition of 50°C, and the penetration was measured in accordance with JIS K2235 (25°C). A penetrometer VR-5610 (manufactured by Shimadzu Corporation) was used as the penetration measuring device. The measured penetration was expressed as a penetration depth (mm) and evaluated using the following evaluation criteria. Evaluation results of "◎", "○", and "△" can be considered to be sufficient performance for practical use.
-Evaluation criteria-
◎: Penetration is 4.0 mm or more. ○: Penetration is 1.0 mm or more and less than 4.0 mm. △: Penetration is 0.5 mm or more and less than 1.0 mm. ×: Less than 0.5 mm.

[Durability]
Using a Ricoh copier, Imajio MF-6550, 100,000 copies of a test chart with an image area of 6% were made, and the degree of decrease in the charge amount of the developer was evaluated based on the following evaluation criteria. Evaluation results of "◎", "◯", and "△" were judged to be sufficient performance for practical use.
-Evaluation criteria-
◎: Very little decrease in charge amount, excellent durability (2 μC/g or less)
○: Little decrease in charge amount and excellent durability (more than 2 μC/g and less than 4 μC/g)
△: Durability improved compared to conventional wax-containing color toners (more than 4 μC/g and less than 6 μC/g)
×: Low durability (more than 6 μC/g) equivalent to or lower than conventional wax-containing color toner

[Blocking prevention]
In the low-temperature fixability evaluation, the image evaluated at the lower fixation limit + 10°C was cut into 2 cm x 5 cm pieces, the image surfaces were overlapped, and sandwiched between glass slides. A 50 ml ointment bottle containing 60 g of ferrite carrier was placed on the glass slide, and the storage temperature was changed and left for 24 hours. After that, after cooling at room temperature for 1 hour, the overlapping image was peeled off, and the degree of image peeling was confirmed. A rank was determined based on the storage temperature at which image peeling disappeared. Evaluation was performed based on the following evaluation criteria.
-Evaluation criteria-
◎: The storage temperature at which image peeling does not occur is 75°C or higher. ○: The storage temperature at which image peeling does not occur is 70°C or higher but less than 75°C. ×: The storage temperature at which image peeling does not occur is less than 70°C.

[UFP (Ultrafine particles)]
3 mg of toner base particles were weighed and placed in an aluminum dish with an inner diameter of 22 mm, and the dish containing each wax (mold release agent) was placed on a hot plate in a testing device (chamber volume: 1 ^m3 , ventilation rate: 5 times) at a testing laboratory certified by the German environmental label "Blue Angel Mark," and the UFP concentration after heating at 220°C for 10 minutes was measured using an FMPS Model 3091 (manufactured by TSI). The results were evaluated based on the following evaluation criteria.
-Evaluation criteria-
Good: Less than 1.0 x ¹⁰³ particles/ ^cm3 Fair: 1.0 x ¹⁰³ particles/cm3 ^or more and less than 1.0 x ¹⁰⁴ particles/ ^cm3 Bad: 1.0 x ¹⁰⁴ particles/cm3 ^or more and less than 1.0 x ¹⁰⁵ particles/ ^cm3

The present invention includes, for example, the following aspects.
<1> Contains a binder resin and a release agent containing a ketone compound,
The glass transition temperature (Tg) of the binder resin alone is represented by A (°C),
When the glass transition temperature (Tg) of a binder resin containing 10% by mass of the release agent is B (°C),
The toner is characterized by satisfying the condition A-B>5 (°C).
<2> The toner according to <1>, further comprising a styrene-α-methylstyrene copolymer.
<3> The toner according to any one of <1> and <2>, wherein hydrophobic silica particles are added inside the toner particles.
<4> The toner according to any one of <1> to <3>, wherein the melting point of the release agent is 80° C. or higher and 95° C. or lower.
<5> The toner according to any one of <1> to <4>, wherein the release agent has an acid value of 1.0 KOH/g or more.
<6> The toner according to any one of <3> to <5>, wherein the hydrophobicized silica particles have an average primary particle diameter of 50 nm or less.
<7> The toner according to any one of <1> to <6>, wherein the binder resin contains a polyester resin.
<8> An electrostatic latent image carrier;
an electrostatic latent image forming means for forming 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 with toner to form a toner image;
a transfer means for transferring the toner image formed on the electrostatic latent image carrier onto a surface of a recording medium;
a fixing unit for fixing the toner image transferred onto the surface of the recording medium,
The image forming apparatus is characterized in that the toner is the toner described in any one of <1> to <7>.
<9> An electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image bearing member;
a developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image;
a transfer step of transferring the toner image formed on the electrostatic latent image carrier onto a surface of a recording medium;
a fixing step of fixing the toner image transferred onto the surface of the recording medium,
The image forming method is characterized in that the toner is the toner described in any one of <1> to <7>.
<10> A method for producing a printed matter, comprising: forming a toner image on a recording medium using the toner according to any one of <1> to <7>.

The toner described in any one of <1> to <7>, the image forming apparatus described in <8>, the image forming method described in <9>, and the method for producing printed matter described in <10> can solve various problems that have existed in the past and achieve the object of the present invention.

Japanese Patent Application Laid-Open No. 2000-267347 Japanese Patent Application Publication No. 10-232505 JP 2010-066322 A Japanese Patent Application Laid-Open No. 2008-122682 Patent No. 4751229

Claims (9)

Contains a binder resin and a release agent containing a ketone compound,
the binder resin is a polyester resin,
The glass transition temperature (Tg) of the polyester resin composition isolated by the method described below is represented by A (°C),
When the glass transition temperature (Tg) of a polyester resin composition isolated by the method described below containing 10% by mass of the mold release agent composition isolated by the method described below is B (°C),
A and B are measured only once,
A toner characterized by satisfying the condition A-B>5 (°C).
[Method for isolating polyester resin composition ]
100 g of toluene is added to 5 g of toner , and the mixture is left for 24 hours. Then, the mixture is centrifuged at 3,000 rpm using a centrifugal separator to precipitate insoluble matter, which is then separated by decantation. The solution components are evaporated to dryness to isolate the polyester resin composition .
[Method for isolating the release agent composition]
100 g of toluene is added to 5 g of toner and left for 24 hours. Then, a centrifugal separation is performed at 3,000 rpm using a centrifugal separator to precipitate insoluble matter, which is then separated by decantation. 20 g of chloroform is added to 1 g of the insoluble matter and left for 24 hours. Then, a centrifugal separation is performed in the same manner as above to remove the insoluble matter. The solution components are evaporated to dryness to isolate the release agent composition. The toner according to claim 1, further comprising a styrene-alpha methylstyrene copolymer. The toner according to any one of claims 1 and 2, wherein hydrophobic silica particles are added to the interior of the toner particles. The toner according to any one of claims 1 to 3, wherein the melting point of the release agent is 80°C or higher and 95°C or lower. The toner according to any one of claims 1 to 4, wherein the acid value of the release agent is 1.0 mgKOH/g or more. The toner according to any one of claims 3 to 5, wherein the average primary particle diameter of the hydrophobic silica particles is 50 nm or less. an electrostatic latent image carrier;
an electrostatic latent image forming means for forming 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 with toner to form a toner image;
a transfer means for transferring the toner image formed on the electrostatic latent image carrier onto a surface of a recording medium;
a fixing unit for fixing the toner image transferred onto the surface of the recording medium,
7. An image forming apparatus, wherein the toner is the toner according to claim 1. 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 with toner to form a toner image;
a transfer step of transferring the toner image formed on the electrostatic latent image carrier onto a surface of a recording medium;
a fixing step of fixing the toner image transferred onto the surface of the recording medium,
7. An image forming method, wherein the toner is the toner according to claim 1. A method for producing a printed matter, comprising the step of forming a toner image on a recording medium using the toner described in any one of claims 1 to 6.