JP6986409B2 - Dry developer - Google Patents

Description

The present invention relates to, for example, a liquid developer and a dry developer used for developing a latent image formed by an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or the like.

The electrophotographic developer includes a dry developer that uses toner particles made of a material containing a colorant and a binder resin in a dry state, and a liquid developer in which the toner particles are dispersed in an insulating liquid.

In the liquid developer, the toner particles are dispersed in the oil in the insulating liquid, so that the particle size can be reduced as compared with the dry developer. Therefore, it is possible to obtain a high-quality printed matter that surpasses offset printing, and is suitable for commercial printing applications. Further, in recent years, since the demand for high speed has increased, there is a demand for a liquid developer capable of melting and fixing toner particles with a small amount of heat, that is, a liquid developer having excellent low temperature fixability.

Patent Document 1 describes toner particles containing a vinyl-based copolymer resin having a plurality of monomers as constituent monomers, with an object of providing a liquid developer capable of preventing document offset without deteriorating dispersibility. An invention relating to a liquid developer containing an insulating liquid and a dispersant composed of a basic polymer having an alkyl group having 10 to 30 carbon atoms is disclosed.

Japanese Unexamined Patent Publication No. 2012-78575

In both the liquid developer and the dry developer, in order to lower the fixing temperature, it is sufficient to add a plasticizer or the like to the toner to make it easier to melt the toner. When the printed matter is stored in a state where the image surface and the image surface are in close contact with each other, there arises a problem that the image surfaces adhere to each other, that is, so-called document offset is likely to occur.

The present invention relates to a liquid developer and a dry developer having excellent low temperature fixability and document offset resistance.

The present invention
[1] A liquid developer containing a binder resin, a basic compound X, toner particles containing a colorant, a dispersant, and an insulating liquid, wherein the binder resin contains a resin having an acid group. A liquid developer, wherein the basic compound X has a structural unit derived from a polyamine and has a melting point of 55 ° C. or higher.
[2] A dry developer containing toner particles containing a binder resin, a basic compound X, and a colorant, wherein the binder resin contains a resin having an acid group, and the basic compound X is A dry developer having a constituent unit derived from polyamine and having a melting point of 55 ° C. or higher, and a toner raw material containing [3] a binder resin, a basic compound X, and a colorant are melt-kneaded and kneaded. The method for producing toner particles according to the above [1] or [2], which comprises a step of crushing the obtained melt-kneaded product.

The liquid developer and the dry developer of the present invention have the effects of being excellent in low temperature fixability and document offset resistance.

The developer of the present invention contains a resin having an acid group and toner particles containing a basic compound X having a structural unit derived from a polyamine, preferably polyalkyleneimine, and having a predetermined melting point. It is excellent in low temperature fixing property and document offset resistance. Although the reason for exerting such an effect is not clear, the combination of a resin having an acid group, a structural unit derived from a polyamine, preferably polyalkyleneimine, and a basic compound X having a specific melting point (crystalline) can be used. At the time of fixing, the basic compound X is compatible with the resin due to the acid-base interaction to improve the low-temperature fixing property, and at the time of storage of the printed matter, the basic compound X is crystallized and phase-separated from the resin to improve the document offset resistance. It is presumed that it will improve.

The developer of the present invention includes two aspects, a liquid developer and a dry developer.

The first aspect of the present invention is a liquid developer containing toner particles, a dispersant and an insulating liquid, in which the toner particles contain a binder resin, a basic compound X, and a colorant.

The binder resin contains a resin having an acid group. Examples of the acid group include a carboxy group, a sulfo group, a phosphoric acid group and the like.

In the present invention, the resin having an acid group is preferably a polyester resin having a carboxy group from the viewpoint of interaction with the basic compound X.

The binder resin preferably contains a polyester resin. Examples of the polyester-based resin include a polyester resin, a composite resin containing a polyester resin and another resin such as a styrene-based resin, and the like.

The polyester resin is preferably a polycondensate of an alcohol component containing a divalent or higher alcohol and a carboxylic acid component containing a divalent or higher carboxylic acid compound.

Examples of the divalent alcohol include an aliphatic diol, preferably an aliphatic diol having 2 or more and 20 or less carbon atoms, and more preferably 2 or more and 15 or less carbon atoms, or the formula (I) :.

(In the formula, OR and RO are oxyalkylene groups, R is ethylene and / or propylene group, x and y indicate the average number of moles of alkylene oxide added, which are positive numbers, respectively, of x and y. The value of the sum is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, more preferably 6 or less, still more preferably 4 or less).
Examples thereof include an alkylene oxide adduct of bisphenol A represented by bisphenol A, bisphenol A, hydrogenated bisphenol A and the like. Specific examples of the aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol.

As the alcohol component, an alkylene oxide adduct of bisphenol A represented by the formula (I) is preferable from the viewpoint of low temperature fixability. The content of the alkylene oxide adduct of bisphenol A represented by the formula (I) is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more, still more preferably 90 mol% or more in the alcohol component. It is 95 mol% or more, more preferably 100 mol%.

Examples of the divalent carboxylic acid compound include dicarboxylic acids having 3 or more and 30 or less carbon atoms, preferably 3 or more and 20 or less carbon atoms, and more preferably 3 or more and 10 or less carbon atoms, anhydrides thereof, or alkyl groups. Examples thereof include derivatives such as alkyl esters having 1 or more and 3 or less carbon atoms. Specific examples of the dicarboxylic acid include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid, fumaric acid, maleic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, and alkyl having 1 or more and 20 or less carbon atoms. Examples thereof include aliphatic dicarboxylic acids such as succinic acid substituted with a group or an alkenyl group having 2 or more and 20 or less carbon atoms.

As the carboxylic acid component, an aromatic dicarboxylic acid-based compound is preferable, and terephthalic acid is more preferable, from the viewpoint of document offset resistance. The content of terephthalic acid is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more in the carboxylic acid component. Further, from the viewpoint of low temperature fixing property, an aliphatic dicarboxylic acid compound is preferable, and fumaric acid is more preferable. The content of the fumaric acid-based compound is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more in the carboxylic acid component.

Examples of the trivalent or higher carboxylic acid compound include 4 or more and 20 or less carbon atoms, preferably 6 or more and 20 or less carbon atoms, more preferably 7 or more and 15 or less carbon atoms, still more preferably 8 or more and 12 or less carbon atoms, and further. Preferred examples thereof include trivalent or higher carboxylic acids having 9 or more and 10 or less carbon atoms, anhydrides thereof, or derivatives such as alkyl esters having 1 or more and 3 or less carbon atoms in the alkyl group. Specific examples thereof include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid), and acid anhydrides thereof.

The content of the carboxylic acid compound having a valence of 3 or more is preferably 15 mol% or less, more preferably 10 mol% or less from the viewpoint of low temperature fixability in the carboxylic acid component, and from the viewpoint of offset resistance. , Preferably 3 mol% or more, more preferably 5 mol% or more.

The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monovalent carboxylic acid compound as appropriate from the viewpoint of adjusting the molecular weight and softening point of the polyester resin.

The equivalent ratio (COOH group / OH group) of the carboxylic acid component and the alcohol component in the polyester resin is preferably 0.6 or more, more preferably 0.7 or more, and preferably 0.7 or more, from the viewpoint of adjusting the softening point of the polyester resin. It is 1.1 or less, more preferably 1.05 or less.

The polyester resin preferably contains, for example, an alcohol component and a carboxylic acid component in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and if necessary, in the presence of an esterification co-catalyst, a polymerization inhibitor, or the like. It can be produced by polycondensation at a temperature of 130 ° C. or higher, more preferably 170 ° C. or higher, and preferably 250 ° C. or lower, more preferably 240 ° C. or lower.

Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin (II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropyrate bistriethanol aminated, and tin compounds are preferable. The amount of the esterification catalyst used is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, and preferably 1.5 parts by mass or less, based on 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. It is preferably 1 part by mass or less. Examples of the esterification co-catalyst include gallic acid and the like. The amount of the esterification co-catalyst used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass or less, based on 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. More preferably, it is 0.1 part by mass or less. Examples of the polymerization inhibitor include t-butylcatechol and the like. The amount of the polymerization inhibitor used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass or less, based on 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. It is preferably 0.1 parts by mass or less.

In the present invention, the polyester resin may be a polyester resin modified to such an extent that its characteristics are not substantially impaired. Examples of the modified polyester resin include grafting and blocking with phenol, urethane, epoxy and the like by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636 and the like. Examples thereof include a modified polyester resin, and among the modified polyester resins, a urethane-modified polyester resin obtained by urethane-stretching the polyester resin with a polyisocyanate compound is preferable.

The softening point of the polyester resin is preferably 80 ° C. or higher, more preferably 85 ° C. or higher, and improves the low temperature fixability of the toner, from the viewpoint of improving the dispersion stability of the toner particles and improving the storage stability. From the viewpoint of the temperature, it is preferably 120 ° C. or lower, more preferably 110 ° C. or lower, and further preferably 100 ° C. or lower.

The glass transition temperature of the polyester resin is preferably 40 ° C. or higher, more preferably 45 ° C. or higher, and improves low-temperature fixability, from the viewpoint of improving the dispersion stability of the toner particles and improving the storage stability. From the viewpoint, it is preferably 65 ° C. or lower, more preferably 60 ° C. or lower.

The acid value of the polyester resin is preferably 10 mgKOH / g or more, more preferably 15 mgKOH / g or more from the viewpoint of adsorption of the dispersant to the toner particles, and is preferable from the viewpoint of dispersion stability of the toner particles. Is 40 mgKOH / g or less, more preferably 30 mgKOH / g or less.

The content of the resin having an acid group is preferably 90% by mass or more, more preferably 95% by mass or more, and further preferably 100% by mass, that is, only the resin having an acid group is used in the binder resin. However, a resin other than the resin having an acid group may be contained as long as the effect of the present invention is not impaired. Resins other than the resin having an acid group include styrene resin, epoxy resin, polyethylene resin, polypropylene resin, polyurethane resin, silicone resin, phenol resin, aliphatic or alicyclic hydrocarbon resin and the like. One type or two or more types selected from resins can be mentioned.

The content of the binder resin is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and document offset resistance in the toner particles from the viewpoint of low-temperature fixability. From the viewpoint of the above, it is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less.

The basic compound X has a structural unit derived from a polyamine, preferably a polyalkyleneimine.

Examples of the polyalkyleneimine include polyethyleneimine, polypropyleneimine, polybutyleneimine and the like, but in the present invention, polyethyleneimine is preferable from the viewpoint of document offset resistance.

The number average molecular weight of polyalkyleneimine is preferably 300 or more, more preferably 500 or more, still more preferably 1,000 or more from the viewpoint of document offset resistance, and preferably 20,000 or less from the viewpoint of low temperature fixability. It is more preferably 15,000 or less, still more preferably 10,000 or less, still more preferably 5,000 or less.

The basic compound X is a method such as a reaction between polyalkyleneimine and an alkyl halide, a reaction between a polyalkyleneimine and a long-chain monocarboxylic acid, a reaction between a polyalkyleneimine and a hydroxycarboxylic acid, and a reaction between a polyalkyleneimine and an alkyl isocyanate. However, in the present invention, a reaction product of polyalkyleneimine and alkyl isocyanate is preferable from the viewpoint of increasing the melting point.

The number of carbon atoms of the alkyl group of the alkyl isocyanate is preferably 16 or more, more preferably 18 or more from the viewpoint of document offset resistance, and preferably 24 or less, more preferably 22 from the viewpoint of low temperature fixability. It is as follows.

As the alkyl isocyanate, octadecyl isocyanate is preferable from the viewpoint of availability and high melting point.

Polyalkyleneimine and alkylisocyanate can be reacted, for example, by heating in xylene.

The melting point of the basic compound X is 55 ° C. or higher, preferably 57 ° C. or higher, and more preferably 60 ° C. or higher. When the melting point of the basic compound X is 55 ° C. or higher, the crystallinity of the basic compound X is high, so that the document offset resistance is improved. The melting point of the basic compound X is preferably 100 ° C. or lower, more preferably 90 ° C. or lower, still more preferably 85 ° C. or lower, from the viewpoint of low-temperature fixability.

The content of the basic compound X is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and further preferably 10 parts by mass or more with respect to 100 parts by mass of the binder resin from the viewpoint of low temperature fixability. From the viewpoint of document offset resistance, the content is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and further preferably 20 parts by mass or less.

As the colorant, dyes, pigments and the like used as colorants for toner can be used. Examples thereof include carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmin 6B, isoindoline, disazoero and the like. .. In the present invention, the toner particles may be either black toner or color toner.

From the viewpoint of improving the image density, the content of the colorant is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 15 parts by mass or more with respect to 100 parts by mass of the binder resin. Then, from the viewpoint of improving the pulverizability of the toner to reduce the particle size, improving the low-temperature fixability, and improving the dispersion stability of the toner particles to improve the storage stability, 100 mass of the binder resin. It is preferably 100 parts by mass or less, more preferably 70 parts by mass or less, still more preferably 50 parts by mass or less, still more preferably 30 parts by mass or less.

In addition to the binder resin, the basic compound X, and the colorant, the toner particles include a mold release agent, a charge control agent, a charge control resin, a magnetic powder, a fluidity improver, a conductivity adjusting agent, a fibrous substance, and the like. Additives such as a reinforcing filler, an antioxidant, and a cleaning property improving agent may be appropriately contained.

As a method for producing toner particles, a method obtained by melt-kneading a toner raw material containing a binder resin, a basic compound X, and a colorant and crushing the obtained melt-kneaded product, and an aqueous binder resin dispersion. Examples thereof include a method of mixing the aqueous colorant dispersion liquid and combining the binder resin particles and the colorant particles, or a method of stirring the water-based binder resin dispersion liquid and the colorant at high speed. From the viewpoint of improving developability and low-temperature fixability, a method including a step of melt-kneading a toner raw material containing a binder resin, a basic compound X, and a colorant and crushing the obtained melt-kneaded product is preferable.

First, the toner raw material containing the binder resin, the basic compound X, the colorant, and the additives used as necessary are mixed in advance with a mixer such as a Henshell mixer, a super mixer, or a ball mill, and then put into a kneader. It is preferable to supply it, and a Henshell mixer is more preferable from the viewpoint of improving the dispersibility of the colorant and the basic compound X in the binder resin.

Mixing with a Henschel mixer is performed while adjusting the peripheral speed of stirring and the stirring time. The peripheral speed is preferably 10 m / sec or more and 30 m / sec or less from the viewpoint of improving the dispersibility of the colorant and the basic compound X. The stirring time is preferably 1 minute or more and 10 minutes or less from the viewpoint of improving the dispersibility of the colorant and the basic compound X.

Next, the melt kneading of the toner raw material can be performed using a known kneader such as a closed kneader, a uniaxial or biaxial kneader, or a continuous open roll kneader. In the present invention, an open roll type kneader is preferable from the viewpoint of improving the dispersibility of the colorant and the basic compound X and improving the yield of the toner particles after grinding.

Next, after cooling the melt-kneaded product to a extent that it can be pulverized, toner particles can be obtained through a pulverization step and, if necessary, a classification step and the like.

The crushing step may be divided into multiple stages. For example, the melt-kneaded product may be coarsely pulverized to about 1 to 5 mm and then further pulverized. Further, in order to improve the productivity in the pulverization step, the melt-kneaded product may be mixed with inorganic fine particles such as hydrophobic silica and then pulverized.

Examples of the crusher preferably used for coarse crushing include an atomizer, a rotoplex and the like, but a hammer mill and the like may also be used. Further, examples of the pulverizer preferably used for fine pulverization include a fluidized bed type jet mill, an airflow type jet mill, and a mechanical type mill.

Examples of the classifying machine used in the classifying process include an air flow type classifying machine, an inertial type classifying machine, and a sieving type classifying machine. If necessary, the crushing step and the classification step may be repeated.

The volume median particle size (D ₅₀ ) of the toner particles obtained in this step is preferably 3 μm or more, more preferably 4 μm or more, and preferably 15 μm from the viewpoint of improving the productivity of the wet pulverization step described later. Below, it is more preferably 12 μm or less. The volume median particle size (D ₅₀ ) means a particle size in which the cumulative volume frequency calculated by the volume fraction is 50% calculated from the smaller particle size. It is preferable that the toner particles are further refined by wet pulverization or the like after being mixed with the insulating liquid.

The content of the toner particles is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, still more preferably 30 parts by mass or more, and more preferably 30 parts by mass or more, with respect to 100 parts by mass of the insulating liquid, from the viewpoint of high-speed printability. From the viewpoint of improving dispersion stability, the amount is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, still more preferably 70 parts by mass or less, still more preferably 60 parts by mass or less.

The dispersant in the present invention is preferably a basic dispersant having a basic nitrogen-containing group from the viewpoint of high adsorptivity to a resin having an acidic group. The basic nitrogen-containing group includes an amino group (-NH ₂ , -NHR, -NHRR'), an amide group (-C (= O) -NRR'), an imide group (-N (COR) ₂ ), and a nitro group. From the group consisting of _{(-NO 2} ), imino group (= NH), cyano group (-CN), azo group (-N = N-), diazo group (= N ₂ ), and azi group (-N _3). At least one selected is preferred. Here, R and R'represent a hydrocarbon group having 1 to 5 carbon atoms. Among these, an amino group and / or an imino group is preferable from the viewpoint of the adsorptivity of the dispersant to the toner particles, and an imino group is more preferable from the viewpoint of the chargeability of the toner particles.

Examples of the functional group contained in addition to the basic nitrogen-containing group include a hydroxy group, a formyl group, an acetal group, an oxime group, a thiol group and the like.

From the viewpoint of dispersion stability, the proportion of the basic nitrogen-containing group in the basic dispersant is preferably 70% by number or more, more preferably 80% by number or more, and further preferably 90% by number in terms of the number of heteroatoms. The above is more preferably 95% by number or more, still more preferably 100% by number.

From the viewpoint of dispersibility of the liquid developer, the basic dispersant has 16 or more carbon atoms, a hydrocarbon having 16 or more carbon atoms partially substituted with a halogen atom, and 16 carbon atoms having a reactive functional group. The above hydrocarbons, polymers of hydroxycarboxylic acids with 12 or more carbon atoms, polymers of dibasic acids with 2 or more and 22 or less carbon atoms and diols with 2 or more and 22 or less carbon atoms, alkyl (meth) acrylates with 16 or more carbon atoms. It is preferable that it contains a group derived from the polymer, polyolefin, etc. (hereinafter, also referred to as “dispersible group”).

As the hydrocarbon having 16 or more carbon atoms, a hydrocarbon having 16 or more and 24 or less carbon atoms is preferable, and examples thereof include hexadecene, octadecene, icosane, and docosane.

As the hydrocarbon having 16 or more carbon atoms partially substituted with a halogen atom, a hydrocarbon having 16 to 24 carbon atoms partially substituted with a halogen atom is preferable, for example, chlorohexadecane, bromohexadecane, chlorooctadecane, bromo. Examples thereof include octadecane, chloroeicosan, bromoeikosan, chlorodocane, bromodocosan and the like.

As the hydrocarbon having a reactive functional group and having 16 or more carbon atoms, a hydrocarbon having a reactive functional group and having 16 or more carbon atoms and 24 or less carbon atoms is preferable, for example, hexadecenyl succinic acid and octadecenyl succinic acid. Examples thereof include acid, eicosenyl succinic acid, docosenyl succinic acid, hexadecyl glycidyl ether, octadecyl glycidyl ether, eico syl glycidyl ether, doco syl glycidyl ether and the like.

The polymer of hydroxycarboxylic acid having 12 or more carbon atoms is preferably a polymer of hydroxycarboxylic acid having 12 or more and 24 or less carbon atoms, preferably 16 or more and 24 or less carbon atoms, and for example, a polymer of 12-hydroxystearic acid. And so on.

Examples of the polymer of a dibasic acid having 2 or more and 22 or less carbon atoms and a diol having 2 or more and 22 carbon atoms include a polymer of ethylene glycol and sebacic acid, a polymer of 1,4-butanediol and fumaric acid, 1 Examples thereof include a polymer of 6-hexanediol and fumaric acid, a polymer of 1,10-decanediol and sebacic acid, and a polymer of 1,12-dodecanediol and 1,12-dodecanedioic acid.

As the polymer of the alkyl (meth) acrylate having 16 or more carbon atoms, the polymer of the alkyl (meth) acrylate having 16 or more carbon atoms and 24 or less carbon atoms is preferable. Examples thereof include polymers of silmethacrylate.

Examples of the polyolefin include polyethylene, polypropylene, polybutylene, polyisobutene, polymethylpentene, polytetradecene, polyhexadecene, polyoctadecene, polyeicosen, polydocene and the like.

The basic dispersant preferably has a polyolefin skeleton from the viewpoint of dispersibility of the toner particles, more preferably has a polypropylene skeleton and / or a polyisobutene skeleton, and from the viewpoint of solubility of the dispersant in carriers, polyisobutene. It is more preferred to have a skeleton. Therefore, among the dispersible groups, a group derived from polyolefin is preferable, a group derived from polypropylene and / or a group derived from polyisobutene is more preferable, and a group derived from polyisobutene is further preferable.

The basic dispersant is not particularly limited, but is obtained, for example, by reacting a basic nitrogen-containing base material with a dispersible group material.

Examples of the basic nitrogen-containing base raw material include polyalkyleneimine such as polyethyleneimine, polyallylamine, and polyaminoalkylmethacrylate such as polydimethylaminoethylmethacrylate.

The number average molecular weight of the basic nitrogen-containing group raw material is preferably 100 or more, more preferably 500 or more, still more preferably 1,000 or more, and the dispersion of toner particles, from the viewpoint of the adsorptivity of the acidic group to the resin. From the viewpoint of sex, it is preferably 15,000 or less, more preferably 10,000 or less, still more preferably 5,000 or less.

Dispersible group raw materials include halogenated hydrocarbons with 16 or more carbon atoms, hydrocarbons with reactive functional groups with 16 or more carbon atoms, polymers of hydroxycarboxylic acids with 12 or more carbon atoms, and 2 or more carbon atoms. Polymers of 22 or less dibasic acids and diols with 2 or more carbon atoms and 22 or less carbon atoms, hydrocarbon (meth) acrylate polymers with 16 or more carbon atoms having reactive functional groups, polyolefins having reactive functional groups, etc. Can be mentioned. Among these, from the viewpoint of raw material availability and reactivity, it has a halogenated hydrocarbon having 16 or more carbon atoms, a hydrocarbon having a reactive functional group and having 16 or more carbon atoms, and a reactive functional group. A polymer of an alkyl (meth) acrylate having 16 to 24 carbon atoms or a polyolefin having a reactive functional group is preferable. Examples of the reactive functional group include a carboxy group, an epoxy group, a formyl group, an isocyanate group and the like, and among these, a carboxy group or an epoxy group is preferable from the viewpoint of safety and reactivity. Therefore, as the compound having a reactive functional group, a carboxylic acid-based compound is preferable. Examples of the carboxylic acid compound include fumaric acid, maleic acid, ethane acid, propanoic acid, butanoic acid, succinic acid, oxalic acid, malonic acid, tartaric acid, their anhydrides, or alkyl esters having 1 or more and 3 or less carbon atoms thereof. And so on. Specific examples of the dispersible group raw material include halogenated alkanes such as chlorooctadecane, epoxy-modified polyoctadecane methacrylate, polyethylene succinic anhydride, chlorinated polypropylene, polypropylene succinic anhydride, polyisobutene succinic anhydride and the like.

The content of the compound having a polyolefin skeleton in the dispersible base raw material is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 90% by mass or more, from the viewpoint of dispersibility of the toner particles. It is 100% by mass.

The number average molecular weight of the dispersible base material is preferably 500 or more, more preferably 700 or more, still more preferably 900 or more, and the adsorptivity of the dispersant to the toner particles from the viewpoint of the dispersibility of the toner particles. From the viewpoint, it is preferably 5,000 or less, more preferably 4,000 or less, and further preferably 3,000 or less.

The mass ratio of the basic nitrogen-containing group to the dispersible group (basic nitrogen-containing group / dispersible group) in the basic dispersant is preferably 3/97 or more from the viewpoint of adsorptivity to toner particles, and more. It is preferably 5/95 or more, and is preferably 20/80 or less, more preferably 15/85 or less, from the viewpoint of dispersion stability of toner particles. The mass ratio of the basic nitrogen-containing group to the dispersible group in the basic dispersant can be measured by NMR of the basic dispersant, but the basic dispersion in which the basic nitrogen-containing group raw material and the dispersible group raw material are reacted. In the production of the agent, the mass ratio of the reacted raw material compound can also be regarded as the mass ratio of the basic nitrogen-containing group and the dispersible group (basic nitrogen-containing group / dispersible group) in the dispersant.

Other basic dispersants include monomer A having an amino group and formula (II) :.

(In the formula, R ¹ is a hydrogen atom or an alkyl group having 1 or more and 5 or less carbon atoms, preferably a methyl group, and R ² may have a substituent and is an alkyl group or carbon having 1 or more and 22 or less carbon atoms. Indicates an alkenyl group with a number of 2 or more and 22 or less)
Examples thereof include a copolymer C with the monomer B represented by.

As the monomer A having an amino group, the formula (III):
CH ₂ = C (R ⁵ ) COYR ⁶ NR ³ R ⁴ (III)
(In the formula, R ³ and R ⁴ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 or more and 4 or less carbon atoms, and they are bonded to each other to form a ring structure. R ⁵ may represent a hydrogen atom or an alkyl group having 1 or more and 5 or less carbon atoms, preferably a methyl group, and R ⁶ may represent a linear or branched alkylene group having 2 or more and 4 or less carbon atoms. Indicates -O- or -NH-)
A monomer having an amino group represented by, or an acid neutralized product (tertiary amine salt) or a quaternary ammonium salt of this monomer is preferable. Preferred acids for obtaining the above acid neutralized products include hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, maleic acid, fumaric acid, citric acid, tartaric acid, adipic acid, sulfamic acid, toluenesulfonic acid, lactic acid and pyrrolidone. Examples thereof include 2-carboxylic acid and succinic acid. Preferred quaternary agents for obtaining the above quaternary ammonium salt include alkyl halides such as methyl chloride, ethyl chloride, methyl bromide and methyl iodide, dimethyl sulfate, diethyl sulfate, di-n-propyl sulfate and the like. Common alkylating agents are mentioned.

In the formula (III), R ³ and R ⁴ are each independently preferably a linear or branched alkyl group having 1 or more and 4 or less carbon atoms, and NR ³ R ⁴ is preferably a tertiary amino group. Specific examples of R ³ and R ⁴ include a methyl group, an ethyl group, a propyl group, an isopropyl group and the like, and a methyl group is preferable.

Examples of R ⁶ include an ethylene group, a propylene group, a butylene group and the like, and an ethylene group is preferable.

^{Specific examples of the monomer in which NR 3} R ⁴ is a tertiary amino group in the formula (III) (monomer having a tertiary amino group) include a (meth) acrylic acid ester having a dialkylamino group and a dialkylamino group ( Meta) acrylamide and the like can be mentioned. In addition, "(meth) acrylic acid ester" indicates that acrylic acid ester and methacrylic acid ester are included, and "(meth) acrylamide" includes both cases of acrylamide and methacrylamide.

Examples of the (meth) acrylic acid ester having a dialkylamino group include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, diisopropylaminoethyl (meth) acrylate, and dibutylaminoethyl (). Examples thereof include one or more selected from the group consisting of meth) acrylate, diisobutylaminoethyl (meth) acrylate, and dit-butylaminoethyl (meth) acrylate.

Examples of (meth) acrylamide having a dialkylamino group include dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide, dipropylaminopropyl (meth) acrylamide, diisopropylaminopropyl (meth) acrylamide, and dibutylaminopropyl (meth). Examples thereof include one or more selected from the group consisting of acrylamide, diisobutylaminopropyl (meth) acrylamide, and dit-butylaminopropyl (meth) acrylamide.

Among these, (meth) acrylic acid ester having a dialkylamino group is preferable from the viewpoint of small particle size, low viscosity, storage stability, and low temperature fixability, and dimethylaminoethyl (meth) acrylate is more preferable.

The monomer B is represented by the above formula (II), and in the above formula (II), the carbon number of the alkyl group and the alkenyl group represented by ^{R 2 is low viscosity, storage stability, and low temperature.} From the viewpoint of fixability, it is preferably 10 or more, more preferably 12 or more, and from the viewpoint of low temperature fixability, it is 22 or less, preferably 18 or less, more preferably 16 or less, still more preferably 14 or less. The alkyl group or alkenyl group of R ² may be a straight chain or a branched chain, and may have a substituent such as a hydroxyl group.

Therefore, ^{it is preferable that the monomer B contains at least the monomer B2 in which R 2} is an alkyl group or an alkenyl group having 10 or more and 22 or less carbon atoms.

In the monomer B, R ² is a monomer B1 which is an alkyl group having 1 or more and 9 carbon atoms or an alkenyl group having 2 or more carbon atoms and 9 or less carbon atoms, and a monomer B2 which is an alkyl group or an alkenyl group having 10 or more and 22 carbon atoms or less. The molar ratio (monomer B1 / monomer B2) is 0.1 or less, preferably 0.07 or less, more preferably 0.05 or less, still more preferably 0.03 or less, still more preferably, from the viewpoint of low viscosity, storage stability, and low temperature fixability. Is 0.01 or less, and is 0 or more, preferably 0.

Specific examples of the monomer B include methyl (meth) acrylate, ethyl (meth) acrylate, (iso) propyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (iso or tertiary) butyl (meth) acrylate, and the like. 2-Ethylhexyl (meth) acrylate, (iso) octyl (meth) acrylate, (iso) nonyl (meth) acrylate, (iso) decyl (meth) acrylate, (iso) undecyl (meth) acrylate, (iso) dodecyl (meth) ) Acrylate, (iso) tridecyl (meth) acrylate, (iso) tetradecyl (meth) acrylate, (iso) pentadecyl (meth) acrylate, (iso) hexadecyl (meth) acrylate, (iso) heptadecyl (meth) acrylate, (iso) ) Octadecyl (meth) acrylate, (iso) nonadecyl (meth) acrylate, (iso) icocil (meth) acrylate, (iso) eicocil (meth) acrylate, (iso) henicocil (meth) acrylate, (iso) docosyl (meth) Examples include acrylate. One or more of these can be used. Here, "(iso or tertiary)" and "(iso)" mean that both the case where these groups are present and the case where they are not present are included, and when these groups are not present. Indicates that it is normal. Further, "(meth) acrylate" indicates that the case of both acrylate and methacrylate is included.

The molar ratio of monomer A to monomer B (monomer A / monomer B) functions as a dispersant, and is 2/98 or more, preferably 3/97 or more, more preferably 5 from the viewpoint of low viscosity and storage stability. / 95 or more, more preferably 7/93 or more, 50/50 or less, preferably 40/60 or less, more preferably 35/65 or less, from the viewpoint of low viscosity, storage stability, and low temperature fixability. It is more preferably 25/75 or less, still more preferably 20/80 or less.

The total content of the monomer A and the monomer B in all the monomers used in the copolymer C is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and preferably 100. It is mass% or less, more preferably 100% by mass.

The polymerization of Monomer A and Monomer B is carried out by heating to about 40 to 140 ° C. in a solvent in the presence of a polymerization initiator such as 2,2'-azobis (2,4-dimethylvaleronitrile). Can be made to.

The number average molecular weight of the basic dispersant is preferably 2,000 or more, more preferably 2,500 or more, still more preferably 3,000 or more, still more preferably 3,500 or more, from the viewpoint of low viscosity and low temperature fixability, and From the same viewpoint, it is preferably 10,000 or less, more preferably 9,000 or less, still more preferably 8,000 or less.

The content of the basic dispersant is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and further preferably 2 parts by mass or more with respect to 100 parts by mass of the toner particles from the viewpoint of dispersion stability of the toner particles. From the viewpoint of the chargeability of the toner, it is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and further preferably 5 parts by mass or less.

The liquid developer of the present invention may contain a known dispersant other than the basic dispersant, but the content of the basic dispersant is preferably 50% by mass or more in the dispersant. It is more preferably 70% by mass or more, further preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 100% by mass.

The insulating liquid in the present invention means a liquid in which electricity does not easily flow, but in the present invention, the conductivity of the insulating liquid is preferably 1.0 × 10 ^-11 S / m or less, more preferably 5.0. It is × 10 ^-12 S / m or less, and preferably 1.0 × 10 ^-13 S / m or more.

Examples of the insulating liquid include hydrocarbon-based insulating liquids such as aliphatic hydrocarbons, alicyclic hydrocarbons and aromatic hydrocarbons, halogenated hydrocarbons, polysiloxanes, vegetable oils and the like. In the present invention, from the viewpoint of improving the dispersion stability of the toner particles and improving the storage stability, the insulating liquid preferably contains a hydrocarbon-based insulating liquid, and contains an aliphatic hydrocarbon-based solvent. It is more preferable, and it is further preferable to contain polyisobutene from the viewpoint of dispersion stability and chargeability.

In the present invention, polyisobutene is obtained by polymerizing isobutene by a known method, for example, a cationic polymerization method using a catalyst, and then hydrogenating the double bond at the terminal.

Examples of the catalyst used in the cationic polymerization method include aluminum chloride, an acidic ion exchange resin, sulfuric acid, boron fluoride and a complex thereof. Further, the polymerization reaction can be controlled by adding a base to the catalyst.

The degree of polymerization of polyisobutene is preferably 8 or less, more preferably 6 or less, still more preferably 5 or less, still more preferably 4 or less, from the viewpoint of improving the low temperature fixability of the toner. Further, from the viewpoint of suppressing charger contamination, it is preferably 2 or more, and more preferably 3 or more.

It is preferable that the unreacted component of isobutylene and the high boiling point component having a high degree of polymerization generated during the polymerization reaction are removed by distillation. Examples of the distillation method include a simple distillation method, a continuous distillation method, a steam distillation method and the like, and these methods can be used alone or in combination. The apparatus used for distillation is not particularly limited in material, shape, model and the like, and examples thereof include a distillation column filled with a filler such as Raschig ring and a shelf-stage distillation column having a dish-shaped shelf. Further, the number of theoretical plates indicating the separation ability of the distillation column is preferably 10 or more. In addition, conditions such as the amount of feed to the distillation column, the reflux ratio, and the amount of withdrawal can be appropriately selected by the distillation apparatus.

Since the product obtained by the polymerization reaction has a double bond at the polymerization terminal, a hydrogenated product is obtained by the hydrogenation reaction. The hydrogenation reaction can be carried out, for example, by using nickel, palladium or the like as a hydrogenation catalyst at a temperature of 180 to 230 ° C., and contacting hydrogen with a pressure of 2 to 10 MPa.

Examples of commercially available insulating liquids containing polyisobutene include "NAS-3", "NAS-4", and "NAS-5H" (all of which are manufactured by NOF CORPORATION). One or more of these can be combined.

The content of the hydrocarbon-based insulating liquid is preferably 5% by mass or more, more preferably 20% by mass or more, still more preferably 40% by mass or more, still more preferably 60% by mass or more, still more preferably 60% by mass or more in the insulating liquid. It is 80% by mass or more, more preferably 90% by mass or more.

The boiling point of the insulating liquid, preferably a hydrocarbon-based insulating liquid, is preferably 120 ° C. or higher, more preferably 140 ° C. or higher, from the viewpoint of suppressing thickening of the liquid developer on the roller and improving the film-forming property. More preferably 160 ° C or higher, further preferably 180 ° C or higher, further preferably 200 ° C or higher, further preferably 220 ° C or higher, and from the viewpoint of further improving the low temperature fixability of the toner, crushing the toner during wet grinding. From the viewpoint of further improving the properties and obtaining toner particles having a small particle size, the temperature is preferably 300 ° C. or lower, more preferably 280 ° C. or lower, and further preferably 260 ° C. or lower. When two or more kinds of insulating liquids are combined, it is preferable that the boiling point of the combined insulating liquid mixture is within the above range.

The viscosity of the insulating liquid at 25 ° C. is preferably 1 mPa · s or more, more preferably 1 mPa · s or more, from the viewpoint of improving the developability and suppressing the thickening of the liquid developer on the roller to improve the film forming property. 1.5 mPa · s or more, preferably 100 mPa · s or less, more preferably 50 mPa · s or less, still more preferably 20 mPa · s or less, still more preferably 10 mPa · s or less, still more preferably 5 mPa · s or less. ..

The liquid developer is obtained by dispersing toner particles in an insulating liquid. From the viewpoint of reducing the particle size of the toner particles, it is preferable to disperse the toner particles in an insulating liquid and then wet-pulverize the toner particles to obtain a liquid developer.

As a method for mixing the toner particles, the dispersant, and the insulating liquid, a method of stirring with a stirring / mixing device or the like is preferable.

The stirring / mixing device is not particularly limited, but a high-speed stirring / mixing device is preferable from the viewpoint of improving the productivity and storage stability of the toner particle dispersion, and specifically, Despa (manufactured by Asada Iron Works Co., Ltd.). TK Homomixer, TK Homo Disperser, TK Robomix (all manufactured by Primex Co., Ltd.), Claire Mix (manufactured by M Technique Co., Ltd.), Kady Mill (manufactured by Kady International Co., Ltd.) ) Etc. are preferable.

By mixing with the high-speed stirring and mixing device, the toner particles are pre-dispersed, the toner particle dispersion liquid can be obtained, and the productivity of the liquid developer by the next wet grinding is improved.

From the viewpoint of improving the image density, the solid content concentration of the toner particle dispersion is preferably 20% by mass or more, more preferably 30% by mass or more, still more preferably 33% by mass or more, and the toner particles are stably dispersed. From the viewpoint of improving the properties and the storage stability, it is preferably 50% by mass or less, more preferably 45% by mass or less, and further preferably 40% by mass or less.

Wet pulverization is a method of mechanically pulverizing toner particles dispersed in an insulating liquid in a state of being dispersed in the insulating liquid.

As the device to be used, for example, a commonly used stirring / mixing device such as an anchor blade can be used. Among the stirring and mixing devices, high-speed stirring and mixing devices such as Despa (manufactured by Asada Iron Works Co., Ltd.) and TK Homomixer (manufactured by Primix Corporation), crushers or kneaders such as roll mills, bead mills, kneaders, and extruders. And so on. A plurality of these devices can be combined.

Among these, the use of a bead mill is used from the viewpoint of reducing the particle size of the toner particles, improving the dispersion stability of the toner particles to improve the storage stability, and reducing the viscosity of the dispersion liquid. preferable.

In the bead mill, toner particles having a desired particle size and particle size distribution can be obtained by controlling the particle size and filling rate of the medium to be used, the peripheral speed of the rotor, the residence time, and the like.

The solid content concentration of the liquid developer is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and the dispersion stability of the toner particles from the viewpoint of improving the image density. From the viewpoint of improving storage stability, it is preferably 50% by mass or less, more preferably 45% by mass or less, and further preferably 40% by mass or less.

The content of the toner particles in the liquid developer is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and the dispersion stability of the toner particles is preferable from the viewpoint of high-speed printing. From the viewpoint of sex, it is preferably 50% by mass or less, more preferably 45% by mass or less, and further preferably 40% by mass or less.

The volume median particle diameter (D ₅₀ ) of the toner particles in the liquid developer is preferably 0.5 μm or more, more preferably 1 μm or more, still more preferably 1.5 μm or more, from the viewpoint of reducing the viscosity of the liquid developer. From the viewpoint of improving the image quality of the liquid developer, it is preferably 5 μm or less, more preferably 3 μm or less, and further preferably 2.5 μm or less.

The content of the insulating liquid in the liquid developer is preferably 50% by mass or more, more preferably 55% by mass or more, still more preferably 60% by mass or more, and from the viewpoint of dispersion stability of the toner particles. From the viewpoint of high-speed printing, it is preferably 90% by mass or less, more preferably 85% by mass or less, and further preferably 80% by mass or less.

The viscosity of the liquid developer having a solid content concentration of 25% by mass at 25 ° C. is preferably 3 mPa · s or more, more preferably 5 mPa · s, from the viewpoint of improving the dispersion stability of the toner particles and improving the storage stability. Above, more preferably 6 mPa · s or more, further preferably 7 mPa · s or more, and from the viewpoint of improving the fixability of the liquid developer, preferably 60 mPa · s or less, more preferably 50 mPa · s or less, more. It is preferably 40 mPa · s or less, more preferably 37 mPa · s or less, still more preferably 35 mPa · s or less, still more preferably 32 mPa · s or less, still more preferably 28 mPa · s or less, still more preferably 24 mPa · s or less, still more preferably. It is 20 mPa · s or less, more preferably 16 mPa · s or less.

A second aspect of the present invention is a dry developer containing toner particles containing a binder resin, a basic compound X, and a colorant.

The binding resin, the basic compound X, and the colorant are the same as in the first aspect.

In the second aspect, the content of the binder resin is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more in the toner particles from the viewpoint of low temperature fixability. From the viewpoint of document offset resistance, it is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less.

In the second aspect, the content of the basic compound X is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, still more preferably 5 parts by mass or more, with respect to 100 parts by mass of the binder resin from the viewpoint of low temperature fixability. It is 10 parts by mass or more, and from the viewpoint of document offset resistance, it is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and further preferably 20 parts by mass or less.

In the second aspect, the content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass with respect to 100 parts by mass of the binder resin from the viewpoint of improving the image concentration and low temperature fixability of the toner. The above, and preferably 40 parts by mass or less, more preferably 30 parts by mass or less.

The toner particles of the second aspect include mold release agents, charge control agents, magnetic powders, fluidity improvers, conductivity adjusting agents, reinforcing fillers such as fibrous substances, antioxidants, cleaning property improving agents and the like. Additives may be included.

The toner particles of the second aspect may be toner obtained by any known method such as a melt-kneading method, an emulsification phase inversion method, a polymerization method, etc., but from the viewpoint of productivity and dispersibility of the colorant. , Grinding toner by melt kneading method is preferable. In the case of crushed toner by the melt-kneading method, for example, raw materials such as a binder resin, a colorant, a mold release agent, and a charge control agent are uniformly mixed with a mixer such as a Henshell mixer, and then a closed kneader, 1 shaft or 2 It can be manufactured by melt-kneading with a shaft extruder, an open roll type kneader, etc., cooling, crushing, and classifying.

It is preferable to use an external additive for the toner particles in order to improve the transferability. Examples of the external additive include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as resin particles such as melamine-based resin fine particles and polytetrafluoroethylene resin fine particles. The above may be used together. Among these, silica is preferable, and from the viewpoint of toner transferability, hydrophobicized silica is more preferable.

Examples of the hydrophobizing agent for hydrophobizing the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), silicone oil, octyltriethoxysilane (OTES), and methyltriethoxysilane. Will be.

The average particle size of the external additive is preferably 5 nm or more, more preferably 10 nm or more, and preferably 250 nm or less, more preferably 200 nm or less, and further, from the viewpoint of the chargeability, fluidity, and transferability of the toner. It is preferably 90 nm or less.

The content of the external additive is preferably 0.05 parts by mass or more, more preferably 0.1 with respect to 100 parts by mass of the toner particles before being treated with the external additive, from the viewpoint of chargeability, fluidity, and transferability of the toner. It is more than parts by mass, more preferably 0.3 parts by mass or more, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less.

_{The volume median particle size (D 50} ) of the toner particles of the second aspect is preferably 3 μm or more, more preferably 4 μm or more, and preferably 15 μm or less, more preferably 10 μm or less. In the present specification, the volume median particle size (D ₅₀ ) means a particle size in which the cumulative volume frequency calculated by the volume fraction is 50% calculated from the smaller particle size. When the toner particles are treated with an external additive, the volume median particle diameter of the toner particles before being treated with the external additive is defined as the volume median particle diameter of the toner.

The glass transition temperature of the toner particles is preferably 40 ° C. or higher, more preferably 43 ° C. or higher from the viewpoint of document offset resistance, and preferably 70 ° C. or lower, more preferably 65 ° C. or higher from the viewpoint of low temperature fixability. It is below ° C.

The toner particles can be used as they are as a toner for one-component development or as a two-component developer mixed with a carrier in a one-component development method or a two-component development method image forming apparatus, respectively.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The physical properties of the resin and the like were measured by the following methods.

[Plastic softening point]
Using the flow tester "CFT-500D" (manufactured by Shimadzu Corporation), while heating a 1 g sample at a heating rate of 6 ° C / min, a load of 1.96 MPa was applied by a plunger to a diameter of 1 mm and a length of 1 mm. Extrude from the nozzle of. The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is used as the softening point.

[Glass transition temperature of resin and toner particles]
Using the differential scanning calorimeter "DSC210" (manufactured by Seiko Electronics Inc.), weigh 0.01 to 0.02 g of the sample in an aluminum pan, raise the temperature to 200 ° C, and then lower the temperature from that temperature to 0 at a temperature reduction rate of 10 ° C / min. Cool to ° C. Next, the sample is heated at a heating rate of 10 ° C./min, and the endothermic peak is measured. The temperature at the intersection of the extension of the baseline below the maximum peak temperature of heat absorption and the tangent line indicating the maximum slope from the rising portion of the peak to the peak of the peak is defined as the glass transition temperature.

[Acid value of resin]
Measure by the method of JIS K 0070. However, only the measurement solvent is changed from the mixed solvent of ethanol and ether specified in JIS K 0070 to the mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Melting point of basic compound]
Using the differential scanning calorimeter "DSC210" (manufactured by Seiko Electronics Inc.), weigh 0.01 to 0.02 g of the sample in an aluminum pan, raise the temperature to 200 ° C, and then lower the temperature from that temperature to 0 at a temperature reduction rate of 10 ° C / min. Cool to ° C. Next, the sample is heated at a heating rate of 10 ° C./min, and the endothermic peak is measured.

[Volume medium particle size of toner particles before mixing with insulating liquid]
Measuring machine: Coulter Multisizer II (manufactured by Beckman Coulter Co., Ltd.)
Aperture diameter: 100 μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (manufactured by Beckman Coulter Co., Ltd.)
Electrolyte: Isoton II (manufactured by Beckman Coulter Co., Ltd.)
Dispersion solution: Emulgen 109P (manufactured by Kao Co., Ltd., polyoxyethylene lauryl ether, HLB (griffin): 13.6) was dissolved in an electrolytic solution to adjust the content to 5% by mass. Is added and dispersed for 1 minute with an ultrasonic disperser (machine name: US-1, manufactured by SND Co., Ltd., output: 80 W). Then, 25 mL of the electrolytic solution is added and further dispersed by an ultrasonic disperser for 1 minute to prepare a sample dispersion.
Measurement conditions: To 100 mL of the electrolytic solution, add the sample dispersion so that the particle size of 30,000 particles can be measured in 20 seconds, measure 30,000 particles, and measure the volume from the particle size distribution. Determine the medium particle size (D ₅₀ ).

[Number average molecular weight (Mn) of polyalkyleneimine and basic nitrogen-containing group raw materials]
The molecular weight distribution is measured by the gel permeation chromatography (GPC) method shown below, and the number average molecular weight is determined.
_{(1) Preparation of sample solution Dissolve the sample at 0.15 mol / L in a solution of Na 2} SO ₄ in a 1% acetic acid aqueous solution so that the concentration becomes 0.2 g / 100 mL. Next, this solution is filtered using a fluororesin filter "FP-200" (manufactured by Sumitomo Electric Industries, Ltd.) having a pore size of 0.2 μm to remove insoluble components, and a sample solution is used.
(2) Molecular weight measurement Using the following measuring device and analysis column, a solution of Na ₂ SO ₄ dissolved in a 1% acetic acid aqueous solution at 0.15 mol / L as an eluent was flowed at a flow rate of 1 mL per minute at 40 ° C. Stabilize the column in a constant temperature bath. Inject 100 μL of the sample solution into it and measure. The molecular weight of the sample is calculated based on the calibration curve prepared in advance. At this time, the calibration curve includes several types of standard pullulan (P-5 (Mw 5.9 × 10 ³ ), P-50 (Mw 4.73 × 10 ⁴ ), P-200 (Mw 2.12 × 10) manufactured by Showa Denko KK). ⁵ ), P-800 (Mw 7.08 × 10 ⁵ )) is used as a standard sample. The numbers in parentheses indicate the molecular weight.
Measuring device: HLC-8320GPC (manufactured by Tosoh Corporation)
Analytical column: α + α-M + α-M (manufactured by Tosoh Corporation)

[Number average molecular weight (Mn) of dispersible base material]
(1) Preparation of sample solution The dispersible base material was dissolved in tetrahydrofuran so that the concentration was 0.5 g / 100 mL. Next, this solution was filtered using a fluororesin filter "FP-200" (manufactured by Sumitomo Electric Industries, Ltd.) having a pore size of 2 μm to remove insoluble components, and used as a sample solution.
(2) Measurement of molecular weight distribution Using the following measuring device and analytical column, flow tetrahydrofuran as an eluent at a flow rate of 1 mL / min and stabilize the column in a constant temperature bath at 40 ° C. Inject 100 μL of the sample solution into it and measure. The molecular weight of the sample is calculated based on the calibration curve prepared in advance. At this time, the calibration curve includes several types of monodisperse polystyrene (A-500 (Mw 5.0 x 10 ² ), A-1000 (Mw 1.01 x 10 ³ ), A-2500 (Mw 2.63 x 10) manufactured by Tosoh Corporation. ³ ), A-5000 (Mw 5.97 × 10 ³ ), F-1 (Mw 1.02 × 10 ⁴ ), F-2 (Mw 1.81 × 10 ⁴ ), F-4 (Mw 3.97 × 10 ⁴ ), F-10 (Mw 9.64 × 10 ⁴ ), F-20 (Mw 1.90 × 10 ⁵ ), F-40 (Mw 4.27 × 10 ⁵ ), F-80 (Mw 7.06 × 10 ⁵ ), F-128 (Mw 1.09 × 10 ⁶⁾ )) Is used as a standard sample. The numbers in parentheses indicate the molecular weight.
Measuring device: HLC-8220GPC (manufactured by Tosoh Corporation)
Analytical column: GMHXL + G3000HXL (manufactured by Tosoh Corporation)

[Number average molecular weight of dispersant (Mn)]
The molecular weight distribution is measured by the gel permeation chromatography (GPC) method shown below, and the number average molecular weight is determined.
(1) Preparation of sample solution Dissolve the dispersant in chloroform so that the concentration becomes 0.2 g / 100 mL. Next, this solution is filtered using a fluororesin filter "FP-200" (manufactured by Sumitomo Electric Industries, Ltd.) having a pore size of 0.2 μm to remove insoluble components, and a sample solution is used.
(2) Molecular weight measurement Using the following measuring device and analysis column, a chloroform solution of 1.00 mmol / L Fermin DM2098 (manufactured by Kao Corporation) was flowed at a flow rate of 1 mL per minute in a constant temperature bath at 40 ° C. Stabilize the column inside. Inject 100 μL of the sample solution into it and measure. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. At this time, the calibration curve includes several types of monodisperse polystyrene (A-500 (Mw 5.0 x 10 ² ), A-5000 (Mw 5.97 x 10 ³ ), F-2 (Mw 1.8 1 x 10) manufactured by Tosoh Corporation. ⁴ ), F-10 (Mw 9.64 × 10 ⁴ ), F-40 (Mw 4.27 × 10 ⁵ )) are used as standard samples. The numbers in parentheses indicate the molecular weight.
Measuring device: HLC-8220GPC (manufactured by Tosoh Corporation)
Analytical column: K-804L (manufactured by Showa Denko KK)

[Conductivity of insulating liquid]
Put 25 g of insulating liquid in a 40 mL glass sample tube "Screw No. 7" (manufactured by Maruemu Co., Ltd.), and use a non-aqueous conductivity meter "DT-700" (manufactured by Dispersion Technology) to attach the electrodes. Immerse in an insulating liquid, measure 20 times at 25 ° C, calculate the average value, and measure the conductivity. The smaller the value, the higher the resistance.

[Boiling point of insulating liquid]
Using the differential scanning calorimeter "DSC210" (manufactured by Seiko Electronics Inc.), weigh 6.0 to 8.0 mg of the sample into an aluminum pan, raise the temperature to 350 ° C at a heating rate of 10 ° C / min, and set the endothermic peak. Measure. The endothermic peak on the highest temperature side is the boiling point.

[Viscosity of insulating liquids and liquid developers at 25 ° C]
Put 6 to 7 mL of the measuring solution in a 10 mL screw tube, and use the rotary vibration viscometer "Viscomate VM-10A-L" (manufactured by Seconic Co., Ltd., detection terminal: titanium, φ8 mm) at the tip of the detection terminal. Fix the screw tube at the position where the liquid level comes 15 mm above the part, and measure the viscosity at 25 ° C.

[Solid concentration of toner particle dispersion and liquid developer]
Dilute 10 parts by mass of the sample with 90 parts by mass of hexane and rotate it for 20 minutes at a rotation speed of 25,000 r / min using a centrifuge "H-201F" (manufactured by Kokusan Co., Ltd.). After standing, the supernatant is removed by decantation, diluted with 90 parts by mass of hexane, and centrifuged again under the same conditions. After removing the supernatant liquid by decantation, the lower layer is dried in a vacuum dryer at 0.5 kPa at 40 ° C. for 8 hours, and the solid content concentration is calculated from the following formula.

[Volume medium particle size of toner particles in liquid developer (D ₅₀ )]
Using the laser refraction / scattering particle size measuring device "Mastersizer 2000" (Malburn), Isopar L (Exxon Mobile, Isoparaffin, viscosity at 25 ° C, 1 mPa · s) is added to the measuring cell, and the scattering intensity is increased. _{The volume median particle size (D 50} ) is measured under the conditions of a particle refractive index of 1.58 (imaginary part 0.1) and a dispersion medium refractive index of 1.42 at a concentration of 5 to 15%.

[Volume medium particle size of toner particles in dry developer]
Measuring machine: Coulter Multisizer II (manufactured by Beckman Coulter Co., Ltd.)
Aperture diameter: 50 μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (manufactured by Beckman Coulter Co., Ltd.)
Electrolyte: Isoton II (manufactured by Beckman Coulter Co., Ltd.)
Dispersion solution: Emulgen 109P (manufactured by Kao Co., Ltd., polyoxyethylene lauryl ether, HLB (griffin): 13.6) was dissolved in an electrolytic solution to adjust the content to 5% by mass. Was added and dispersed with an ultrasonic disperser (machine name: US-1, manufactured by SND Co., Ltd., output: 80 W) for 1 minute, then 25 mL of the electrolytic solution was added, and further to the ultrasonic disperser. Disperse for 1 minute to prepare a sample dispersion.
Measurement conditions: To 100 mL of the electrolytic solution, add the sample dispersion so that the particle size of 30,000 particles can be measured in 20 seconds, measure 30,000 particles, and measure the volume from the particle size distribution. Determine the medium particle size (D ₅₀ ).

[Average particle size of external additive]
The average particle size refers to the number average particle size, and the particle size of 500 particles (the average value of the major axis and the minor axis) is measured from a scanning electron microscope (SEM) photograph and used as the average number of the particles.

Resin production example 1
The raw material monomers of the polyester resin shown in Table 1, the esterification catalyst, and the polymerization inhibitor were placed in a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and used with a mantle heater. The reaction was carried out at 210 ° C. for 4 hours and further at 8.3 kPa until the softening point shown in Table 1 was reached to obtain a polyester resin (resin P1) having the physical properties shown in Table 1.

Resin production example 2
The polyester resin raw material monomer and esterification catalyst shown in Table 1 are mixed with a nitrogen introduction tube, a dehydration tube equipped with a fractional distillation tube through which hot water at 98 ° C is passed, a stirrer, and a 10 L four-necked flask equipped with a thermocouple. I put it in. After raising the temperature to 180 ° C., the temperature was raised to 210 ° C. over 5 hours, and the reaction was carried out until the reaction rate reached 90%. Further, the reaction was carried out at 8.3 kPa, and when the desired softening point was reached, the reaction was terminated to obtain a polyester resin (resin P2) having the physical characteristics shown in Table 1. In the resin production example, the reaction rate means the value of the amount of produced reaction water (mol) / the theoretical amount of produced water (mol) × 100.

Resin production example 3
1567 g of xylene was placed in a 5 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, and the temperature was raised to 130 ° C. A mixture of the raw material monomer of the styrene resin and the polymerization initiator shown in Table 1 was added dropwise at 130 ° C. over 1.5 hours, and the same temperature was maintained for another 1.5 hours to carry out an addition polymerization reaction. The temperature was raised to 160 ° C., the reaction was carried out for 1 hour, the temperature was raised to 200 ° C., and the temperature was maintained for 1 hour to remove xylene. Further, the remaining xylene was removed at 8.3 kPa to obtain a styrene acrylic resin (resin S) having the physical characteristics shown in Table 1.

Production Example of Basic Compound Put the polyalkyleneimine shown in Table 2 in a 2 L 4-necked flask equipped with a cooling tube, nitrogen introduction tube, stirrer, dehydration tube and thermocouple, and replace the inside of the reaction vessel with nitrogen gas. did. While stirring, octadecyl isocyanate shown in Table 2 melted at 30 ° C. was added as a reaction raw material, and the mixture was stirred for 30 minutes. Then, the inside of the reaction vessel was heated to 160 ° C. and held for 1 hour to obtain compounds A to D having the physical characteristics shown in Table 2.

Production example of dispersant A 20 parts by mass of polyethyleneimine (polyethylenimine 600, manufactured by Genuine Chemical Co., Ltd., branched structure, Mn: 2,500) as a basic nitrogen-containing base raw material is used as a cooling tube, nitrogen introduction tube, stirrer, dehydration tube. And placed in a 2 L 4-necked flask equipped with a thermocouple, and the inside of the reaction vessel was replaced with nitrogen gas. A solution prepared by dissolving 197 parts by mass of polyisobutene succinic anhydride (PIBSA) (OLOA15500, manufactured by Chevron Japan Co., Ltd., effective content: 78% by mass, Mn: 1,100) as a dispersible base raw material in 217 parts by mass of xylene while stirring. Was added dropwise at room temperature over 1 hour. After completion of the dropping, the mixture was kept at room temperature for 30 minutes. Then, the inside of the reaction vessel was heated to 150 ° C. and held for 1 hour, then heated to 160 ° C. and held for 1 hour. The solvent was distilled off under reduced pressure to 8.3 kPa at 160 ° C., and the time point at which the peak of acid anhydride derived from PIBSA (1780 cm ^-1 ) disappeared from IR analysis and the peak derived from imide bond (1700 cm ^-1 ) occurred. Dispersant A (Mn: 6,700, basic nitrogen-containing base material / dispersible group material (mass ratio): 11/89) was obtained as the reaction end point.

Production Example of Dispersant B 100 g of a solvent (methyl ethyl ketone) was placed in a 2 L four-necked flask equipped with a cooling tube, a nitrogen introduction tube, a stirrer and a thermocouple, and the inside of the reaction vessel was replaced with nitrogen gas. The inside of the reaction vessel is heated to 80 ° C, and dimethylaminoethyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 80 g, 1-octadecyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 20 g, and 2,2'-as a polymerization initiator. A mixture of 3 g of azobis (2,4-dimethylvaleronitrile) (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 2 hours to carry out a polymerization reaction. After completion of the dropping, the reaction was carried out at 80 ° C. for another 3 hours. The solvent was distilled off at 80 ° C. to obtain a dispersant B (Mn / Mw = 4,700 / 15,000).

Examples A1 to A4 and Comparative Examples A1 to A5 (Examples A1 to A4 are reference examples).
20 parts by mass of the binder resin, colorant "ECB-301" (manufactured by Dainichi Seika Kogyo Co., Ltd., phthalocyanine blue 15: 3) and basic compounds shown in Table 3 (Comparative Examples A1 to A3 are not used). Using a 20 L Henchel mixer in advance, the mixture was stirred and mixed at a rotation speed of 1500 r / min (peripheral speed 21.6 m / sec) for 3 minutes, and then melt-kneaded under the conditions shown below.
[Melting and kneading conditions]
A continuous double open roll type kneader "Kneedex" (manufactured by Nippon Coke Industries Co., Ltd., roll outer diameter: 14 cm, effective roll length: 55 cm) was used. The operating conditions of the continuous double open roll type kneader are high rotation side roll (front roll) rotation speed 75r / min (peripheral speed 32.4m / min), low rotation side roll (back roll) rotation speed 35r / min ( The peripheral speed was 15.0 m / min), and the roll gap at the end on the side of the kneaded material supply port was 0.1 mm. The heating medium temperature and cooling medium temperature in the roll are 90 ° C on the raw material input side of the high rotation side roll and 85 ° C on the kneaded material discharge side, 35 ° C on the raw material input side of the low rotation side roll and 35 ° C on the kneaded material discharge side. there were. The supply speed of the raw material mixture to the kneader was 10 kg / h, and the average residence time in the kneader was about 3 minutes.

The obtained kneaded product was rolled and cooled with a cooling roll, and then coarsely pulverized to about 1 mm using a hammer mill. The obtained coarsely pulverized product was finely pulverized and classified by an air flow jet mill "IDS" (manufactured by Nippon Pneumatic Co., Ltd.) to obtain toner particles having _{a volume medium particle size (D 50) of 10 μm.}

35 parts by mass of the obtained toner particles and the insulating liquid "NAS-4" (manufactured by Nichiyu Co., Ltd., polyisobutene, conductivity: 1.52 x 10 ^-12 S / m, boiling point: 247 ° C, viscosity at 25 ° C: 2 mPa・ S) Put 63.95 parts by mass and 1.05 parts by mass of dispersant A (3 parts by mass with respect to 100 parts by mass of toner particles) in a 1 L polyethylene container, and use "TK Robomix" (manufactured by Primix Co., Ltd.). Was stirred for 30 minutes at a rotation speed of 7,000 r / min under ice-cooling to obtain a toner particle dispersion having a solid content concentration of 36% by mass.

Next, the obtained toner particle dispersion was rotated by a 6-cylinder sand mill "TSG-6" (manufactured by IMEX Co., Ltd.) at a volume filling rate of 60% by volume using zirconia beads having a diameter of 0.8 mm. Wet pulverization was performed at 1300 r / min (peripheral speed 4.8 m / sec) _{until the volume medium particle size (D 50) shown in Table 3 was reached.} After removing the beads by filtration, add 44 parts by mass of the insulating liquid "NAS-4" (manufactured by Nichiyu Co., Ltd.) to 100 parts by mass of the filtrate to dilute the solid content concentration to 25% by mass. A liquid developer having the physical properties shown in 3 was obtained.

Example A5 (reference example)
Example A1 and Example A1 except that "Solsperse 11200" (condensate of polyethyleneimine and carboxylic acid (condensate of 12-hydroxystearic acid, average degree of polymerization 7.0) manufactured by Lubrizol Japan, Inc.) was used instead of the dispersant A. Similarly, a liquid developer was obtained.

Example A6 (reference example)
A liquid developer was obtained in the same manner as in Example A1 except that the dispersant B was used instead of the dispersant A.

Examples B1 to B5 and Comparative Examples B1 to B3
20 parts by mass of the binder resin, colorant "ECB-301" (manufactured by Dainichi Seika Kogyo Co., Ltd., phthalocyanine blue 15: 3) and basic compounds shown in Table 4 were prepared in advance using a 20 L volume Henchel mixer. After stirring and mixing at a rotation speed of 1500 r / min (peripheral speed 21.6 m / sec) for 3 minutes, the mixture was melt-kneaded under the conditions shown below.

[Melting and kneading conditions]
A continuous double open roll type kneader "Kneedex" (manufactured by Nippon Coke Industries Co., Ltd., roll outer diameter: 14 cm, effective roll length: 55 cm) was used. The operating conditions of the continuous double open roll type kneader are high rotation side roll (front roll) rotation speed 75r / min (peripheral speed 32.4m / min), low rotation side roll (back roll) rotation speed 35r / min ( The peripheral speed was 15.0 m / min), and the roll gap at the end on the side of the kneaded material supply port was 0.1 mm. The heating medium temperature and cooling medium temperature in the roll are 90 ° C on the raw material input side of the high rotation side roll and 85 ° C on the kneaded material discharge side, 35 ° C on the raw material input side of the low rotation side roll and 35 ° C on the kneaded material discharge side. there were. The supply speed of the raw material mixture to the kneader was 10 kg / h, and the average residence time in the kneader was about 3 minutes.

The obtained kneaded product was rolled and cooled with a cooling roll, and then coarsely pulverized to about 1 mm using a hammer mill. The obtained coarsely pulverized product was finely pulverized and classified by an air flow jet mill "IDS" (manufactured by Nippon Pneumatic Co., Ltd.) to obtain toner particles having _{a volume medium particle size (D 50) of 10 μm.}

100 parts by mass of the obtained toner particles and 1.0 part by mass of hydrophobic silica "Cabosil (registered trademark) TS720" (manufactured by Cabot Japan Co., Ltd., average particle size; 12 nm) are placed in a Henshell mixer and stirred, and a 150 mesh sieve is used. A dry developer composed of toner particles that passed through the above was obtained.

The low temperature fixability and document offset resistance of the liquid developer obtained in Examples A1 to A6 and Comparative Examples A1 to A5 and the dry developer obtained in Examples B1 to B5 and Comparative Examples B1 to B3 were determined by the following methods. evaluated. The results are shown in Tables 3 and 4.

Test Example 1 [Low temperature fixability]
(1) Drop the liquid developer onto the liquid developer "OK Top Coated Paper" (manufactured by Oji Paper Co., Ltd., basis weight: 127.9 g / m ² , paper thickness: approx. 103 μm), and dry the toner with a wire bar. A thin film was prepared so that the mass was 3.4 g / m ^2. Then, it was kept in a constant temperature bath at 80 ° C. for 10 seconds.

Subsequently, using a fixing machine taken out from "OKI MICROLINE 3010" (manufactured by Oki Data Corporation), the fixing process was performed at a fixing roll temperature of 80 ° C. and a fixing speed of 280 mm / sec. Then, while raising the fixing roll temperature to 160 ° C. by 10 ° C., the fixing treatment as described above was performed, and a fixing image was obtained at each temperature.

Attach the mending tape "Scotch Mending Tape 810" (manufactured by 3M Japan Ltd., width 18 mm) to the obtained fixing image, apply pressure to the tape with a roller so that a load of 500 g is applied, and then apply the tape. It peeled off. The image densities before and after the tape was applied were measured using a colorimeter "Gretag Macbeth Spectroeye" (manufactured by Gretag). The image print portion was measured at 3 points each, and the average value was calculated as the image density. The fixing rate (%) was calculated from the value of the image density after peeling / the image density before pasting × 100, and the temperature at which the fixing rate was 90% or more was defined as the minimum fixing temperature.

(2) Dry-type developer A dry-type developer is mounted on the non-magnetic one-component developer "MICROLINE 5400" (manufactured by Oki Data Corporation), and an unfixed solid with an ^{adhesion amount of 0.3 mg / cm 2 on J paper (manufactured by Fuji Xerox).} The image was printed.
Subsequently, using a fixing machine taken out from "OKI MICROLINE 3010" (manufactured by Oki Data Corporation), the fixing process was performed at a fixing roll temperature of 80 ° C. and a fixing speed of 280 mm / sec. Then, while raising the fixing roll temperature to 160 ° C. by 10 ° C., the fixing treatment as described above was performed, and a fixing image was obtained at each temperature.
Attach the mending tape "Scotch Mending Tape 810" (manufactured by 3M Japan Ltd., width 18 mm) to the obtained fixing image, apply pressure to the tape with a roller so that a load of 500 g is applied, and then apply the tape. It peeled off. The image densities before and after the tape was applied were measured using a colorimeter "Gretag Macbeth Spectroeye" (manufactured by Gretag). The image print portion was measured at 3 points each, and the average value was calculated as the image density. The fixing rate (%) was calculated from the value of the image density after peeling / the image density before pasting × 100, and the temperature at which the fixing rate was 90% or more was defined as the minimum fixing temperature.

Test Example 2 [Document offset resistance]
In the fixing test of Test Example 1, a fixed image portion fixed at 140 ° C. was placed facing each other and superposed, and a ^{load of a surface pressure of 80 g / cm 2} was applied and the image was allowed to stand in an environment at a temperature of 50 ° C. After standing for one day, the superimposed images were taken out, the state of the fixed image part after opening was observed, and the document offset resistance was evaluated according to the following criteria.
〔Evaluation criteria〕
A: There is no peeling sound at the time of peeling, and no image defects are seen. B: There is a peeling sound at the time of peeling, but no image defects are seen. C: There is a peeling sound at the time of peeling, and minute image defects are seen. D: There is a peeling sound at the time of peeling, and a large image defect is seen. E: It is fused and cannot be peeled.

From the above results, it can be seen that the liquid developer and the dry developer of the examples have excellent low temperature fixability and good document offset resistance.
On the other hand, the comparative example in which the basic compound is not used and the comparative example in which the styrene resin is used lack low-temperature fixability, and the comparative example in which the melting point of the basic compound is too low lacks document offset resistance. ing.

The liquid developer and the dry developer of the present invention are suitably used for developing latent images formed by, for example, an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or the like.

Claims (6)

A dry developer containing toner particles containing a binder resin, a basic compound X, and a colorant, wherein the binder resin contains a resin having an acid group, and the basic compound X is a polyalkyleneimine. A dry developer that is a reaction product of alkyl isocyanate and has a melting point of 55 ° C or higher. The dry developer according to claim 1, wherein the polyalkyleneimine is polyethyleneimine. The dry developer according to claim 1 or 2, wherein the polyalkyleneimine has a number average molecular weight of 300 or more. The dry developer according to any one of claims 1 to 3, wherein the alkyl group of the alkyl isocyanate has 16 or more and 24 or less carbon atoms. The dry developer according to any one of claims 1 to 3, wherein the alkyl isocyanate is octadecyl isocyanate. The method for producing a dry developer according to any one of claims 1 to 5 , which comprises a step of melt-kneading a toner raw material containing a binder resin, a basic compound X, and a colorant and crushing the obtained melt-kneaded product. ..