JP5853796B2 - Toner for developing electrostatic image and method for producing the same - Google Patents

Description

  The present invention relates to an electrostatic charge image developing toner and a method for producing the same.

  In recent years, so-called low-temperature fixing technology that fixes a toner image at a lower temperature than before has attracted attention in order to reduce power consumption, increase printing speed, and expand the applicable paper type. As one method for lowering the toner fixing temperature, there is a method in which all or part of the toner binder resin is a polyester resin having a high sharp melt property.

  On the other hand, when a polyester resin is used as the binder resin, the elasticity at the time of fixing is insufficient. To impart this elasticity, a toner using a styrene acrylic resin and using a polyester resin and a styrene acrylic resin in combination has been proposed.

  However, in this case, the polyester resin and the styrene acrylic resin are incompatible or partially compatible with each other at the time of fixing. On the other hand, it leads to deterioration of visibility like glare. Therefore, there is a demand for a toner having excellent low-temperature fixability and excellent low gloss.

  In order to reduce the gloss of toner using a polyester resin, Patent Document 1 proposes a technique for crosslinking a part of the polyester resin. Patent Document 2 proposes a technique using a polyester resin having a high weight average molecular weight and a wide molecular weight distribution.

JP-A-6-130722 Japanese Unexamined Patent Publication No. 7-199583

  However, the technique described in Patent Document 1 has problems in that it is difficult to adjust the crosslinking density, the low-temperature fixability is deteriorated, and the glossiness of the image is insufficient. The technique described in Patent Document 2 also has a problem that the low-temperature fixability is insufficient.

  Accordingly, an object of the present invention is to provide an electrostatic image developing toner that is excellent in low-temperature fixability and excellent in low gloss.

  The inventors of the present invention have accumulated extensive research. As a result, surprisingly, a binder resin comprising a styrene acrylic modified polyester resin having a styrene acrylic content in a specific range and a vinyl resin having a weight average molecular weight and (meth) acrylate content in a specific range. The present inventors have found that the above problems can be solved by using the toner to be included, and have completed the present invention.

  That is, the above object of the present invention is achieved by the following configuration.

  1. In the electrostatic image developing toner containing at least a binder resin, the binder resin includes a styrene acrylic modified polyester resin having a styrene acrylic content of 5 to 40% by mass and a (meth) acrylic acid ester monomer. A toner for developing an electrostatic charge image, comprising: a vinyl resin having a content of derived structural units of 40 to 90% by mass and a weight average molecular weight of 100,000 to 400,000.

  2. The toner for developing an electrostatic charge image has a core-shell structure, wherein the core portion of the core-shell structure includes at least the styrene acrylic modified polyester resin and the vinyl resin, and the shell portion of the core-shell structure includes at least a polyester resin. The above 1. The toner for developing an electrostatic charge image according to 1.

  3. The content of the styrene acrylic modified polyester resin with respect to the total mass of the electrostatic charge image developing toner is 70 to 95% by mass, and the content of the vinyl resin with respect to the total mass of the electrostatic charge developing toner is 5 to 30. The above-mentioned 1. characterized by being mass%. Or 2. The toner for developing an electrostatic charge image according to 1.

  4). A method for producing a toner for developing an electrostatic charge image containing at least a binder resin, the step of obtaining a dispersion of styrene acrylic modified polyester resin particles having a styrene acrylic content of 5 to 40% by mass, and (meth) acrylic A step of obtaining a dispersion of vinyl resin particles having a content of constituent units derived from an acid ester monomer of 40 to 90% by mass and a weight average molecular weight of 100,000 to 400,000; And a step of mixing the dispersion of the polyester resin particles and the dispersion of the vinyl resin particles to agglomerate the styrene acrylic modified polyester resin particles and the vinyl resin particles. Manufacturing method.

  5. 3. The step of aggregating the polyester resin particles to form a shell after the step of aggregating the styrene acrylic modified polyester resin particles and the vinyl resin particles. A method for producing a toner for developing an electrostatic image as described in 1.

  According to the present invention, an electrostatic charge image developing toner having excellent low-temperature fixability and excellent low gloss can be provided.

  The present invention relates to an electrostatic charge image developing toner containing at least a binder resin, wherein the binder resin includes a styrene acrylic modified polyester resin having a styrene acrylic content of 5 to 40% by mass, and a (meth) acrylic ester. A toner for developing an electrostatic charge image, comprising: a vinyl resin having a content of a constituent unit derived from a monomer of 40 to 90% by mass and a weight average molecular weight of 100,000 to 400,000.

  A styrene acrylic modified polyester resin having a styrene acrylic content in the above range and a vinyl resin in which the content of the structural unit derived from the (meth) acrylic acid ester monomer and the weight average molecular weight are in the above range are toner. It is almost incompatible when it is manufactured, but it is compatible when it is fixed on paper. Accordingly, the elasticity of the styrene acrylic modified polyester resin is increased moderately, and the low-temperature fixability and low glossiness of the toner are improved.

  Hereinafter, the configuration of the electrostatic image developing toner of the present invention will be described in detail.

<Styrene acrylic modified polyester resin (A)>
In this section, the styrene acrylic modified polyester resin (A) will be described. Here, the “styrene acrylic modified polyester resin” means that a molecular chain of a styrene acrylic copolymer molecular chain (hereinafter also referred to as a styrene acrylic copolymer segment) is molecularly bonded to a polyester molecular chain (hereinafter also referred to as a polyester segment). A resin composed of polyester molecules with a structure. That is, the styrene acrylic modified polyester resin is a resin having a copolymer structure in which a styrene acrylic copolymer segment is covalently bonded to a polyester segment.

  The content ratio of the styrene acrylic copolymer segment of the styrene acrylic modified polyester resin (A) used in the present invention is 5 to 40% by mass. In the present invention, the content ratio of the styrene acrylic copolymer segment in the styrene acrylic modified polyester molecule is referred to as “styrene acrylic content”, and the ratio (mass of the styrene acrylic copolymer segment in the styrene acrylic modified polyester molecule). Ratio). Specifically, the mass ratio of the polymerizable monomer used for forming the styrene acrylic copolymer segment to the total mass of the polymerizable monomer used when synthesizing the styrene acrylic modified polyester resin. It is.

  By setting the “styrene acrylic content” in the above range, a binder resin capable of achieving both low-temperature fixability and low gloss can be obtained. By setting the content to 5% by mass or more, moderate compatibility can be obtained between the styrene acrylic-modified polyester resin (A) and the vinyl resin (B), and the gloss of the toner image can be suppressed low. The glare is eliminated in the printed document. On the other hand, when the content is 40% by mass or less, the compatibility between the styrene acrylic modified polyester resin (A) and the vinyl resin (B) is moderately suppressed, and the low temperature fixability can be stably maintained.

  The styrene acrylic content of the styrene acrylic modified polyester resin (A) used in the present invention is 5 to 40% by mass as described above, preferably 5 to 30% by mass, and more preferably 10 to 20% by mass. %.

  The content of the styrene acrylic modified polyester resin (A) with respect to the total mass of the resin constituting the toner is preferably 70 to 95% by mass.

  The styrene acrylic modified polyester resin (A) used in the present invention is not particularly limited as long as the molecular structure has two types of segments of a polyester segment and a styrene acrylic copolymer segment. Specifically, a block copolymer structure in which a styrene acrylic copolymer segment is bonded to the end of a polyester segment, or a graft copolymer structure in which a branched structure of a styrene acrylic copolymer segment is formed on a polyester segment. Is mentioned.

  If the manufacturing method of the styrene acrylic modified polyester resin (A) used in the present invention is a method capable of forming a polymer having a structure in which a polyester segment and a styrene acrylic copolymer segment are molecularly bonded, There is no particular limitation. Specific methods for producing the styrene acrylic modified polyester resin (A) include, for example, the methods shown below.

(1) A method for producing a styrene acrylic modified polyester resin (A) by forming a polyester segment in advance and performing a polymerization reaction to form a styrene acrylic copolymer segment in the presence of the polyester segment. Then, a polyvalent carboxylic acid and a polyhydric alcohol are subjected to a condensation reaction for polymerization to form a polyester segment. Next, in the presence of the polyester segment, a vinyl monomer such as a styrene monomer or a (meth) acrylic acid ester monomer is polymerized to form a styrene acrylic copolymer segment. At this time, in addition to the styrene monomer and the (meth) acrylic acid ester monomer, a site capable of reacting with a carboxy group (—COOH) or a hydroxy group (—OH) remaining in the polyester segment, and a vinyl monomer A compound having a reactive site is also used. That is, when this compound reacts with a carboxy group (—COOH) or a hydroxy group (—OH) in the polyester segment, the polyester segment has a structure in which the compound is bonded. A styrene acrylic copolymer segment is formed by addition reaction such as radical polymerization of a styrene monomer and a (meth) acrylic acid ester monomer in the presence of the polyester segment to which the compound is bonded. The At this time, the styrene acrylic modified polyester resin (A) having a structure in which the polyester segment and the styrene acrylic copolymer segment are molecularly bonded through a site capable of reacting with the vinyl monomer of the compound bonded to the polyester segment. Can be formed.

  That is, the method of (1) is “polymerization reaction of at least a styrene monomer and a (meth) acrylate monomer in the presence of a polyester molecular chain to form a styrene acrylic copolymer molecular chain”. It falls under the method. The method (1) includes a method in which the styrene monomer and the (meth) acrylic acid ester monomer (vinyl monomer) are added to the reaction system before the compound is added and bonded to the polyester. There is a method of reacting by adding the compound together with the vinyl monomer described above. The method (1) is preferably used when forming a styrene-acrylic modified polyester resin having a block copolymer structure in which a styrene-acrylic copolymer molecular chain is molecularly bonded to the end of a polyester molecular chain, as will be described later. Is the method.

(2) A method of producing a styrene acrylic modified polyester resin (A) by polymerizing a styrene acrylic copolymer segment in advance and performing a polymerization reaction to form a polyester segment in the presence of the styrene acrylic copolymer segment. In the method, first, a styrene acrylic copolymer segment is formed by addition reaction of a styrene monomer and a vinyl monomer such as a (meth) acrylic acid ester monomer. Next, in the presence of the styrene acrylic copolymer segment, a polyvalent carboxylic acid and a polyhydric alcohol are polymerized to form a polyester segment. At this time, in addition to the polyvalent carboxylic acid and the polyhydric alcohol, a compound having a site capable of reacting with the styrene acrylic copolymer segment and a site capable of reacting with the polyvalent carboxylic acid or polyhydric alcohol is also used. That is, by reacting this compound with the styrene acrylic copolymer segment, the styrene acrylic copolymer segment has a structure in which the compound is bonded. And a polyester segment is formed by carrying out the condensation reaction of polyhydric carboxylic acid and polyhydric alcohol in presence of the styrene acrylic copolymer segment which combined the said compound. At this time, the styrene acrylic modification having a structure in which the styrene acrylic copolymer segment and the polyester segment are molecularly bonded through a site capable of reacting with the polyvalent carboxylic acid or polyhydric alcohol of the compound bonded to the styrene acrylic copolymer segment. A polyester resin (A) can be formed.

(3) A method for producing a styrene acrylic modified polyester resin (A) by forming a polyester segment and a styrene acrylic copolymer segment in advance and bonding them together. A polyester segment is formed by a condensation reaction with alcohol. In addition to the reaction system for forming the polyester segment, a styrene acrylic copolymer segment is formed by addition polymerization of a styrene monomer and a (meth) acrylic acid ester monomer. Next, a system in which a polyester segment and a styrene acrylic copolymer segment coexist is formed, and a compound having a portion capable of binding to the polyester segment and a portion capable of binding to the styrene acrylic copolymer segment is added thereto. . And the styrene acrylic modified polyester resin (A) of the structure where the polyester segment and the styrene acrylic copolymer segment were molecularly bonded can be formed through the compound.

  Among the forming methods (1) to (3), the method (1) is easy to form a styrene acrylic modified polyester resin (A) having a structure in which a styrene acrylic copolymer molecular chain is bonded to a polyester molecular chain terminal. This is preferable because the production process can be simplified. In the method (1), since the polyester segment is formed in advance and then the compound is added and bonded to the polyester segment, the compound has a very high probability of binding to the end of the polyester segment. Therefore, the styrene acrylic modified polyester resin (A) having a structure defined in the present invention can be reliably formed, which is preferable.

  The polyester segment constituting the styrene acrylic modified polyester resin (A) used in the present invention preferably has a glass transition temperature of 40 to 70 ° C., more preferably 50 to 65 ° C. when it is a single polyester molecular chain. . When the glass transition temperature is 40 ° C. or higher, it is possible to form a toner image in which the polyester segments are appropriately aggregated during fixing and the hot offset phenomenon does not occur. In addition, since the glass transition temperature is 70 ° C. or lower, a low-temperature fixing toner that melts a toner image at a lower temperature than before can be produced without inhibiting the melting of the styrene-acrylic copolymer resin during fixing. This is preferable.

  The polyester segment constituting the styrene acrylic modified polyester resin (A) preferably has a weight average molecular weight (Mw) of 1,500 to 60,000 when it is a single polyester molecular chain, and is preferably 3,000 to 40,000. 000 is more preferable. By setting the weight average molecular weight to 1,500 or more, an appropriate cohesive force can be imparted to the entire toner resin, and a toner image that hardly causes a hot offset phenomenon during fixing can be formed. Further, when the weight average molecular weight is 60,000 or less, sufficient melting can be achieved by heating in a short time, and a firm fixed image can be formed by cooling. Therefore, it is preferable in forming a toner image by low-temperature fixing. The weight average molecular weight of the polyester segment and the styrene acrylic copolymer segment can be measured by gel permeation chromatography (GPC).

  The styrene acrylic copolymer segment constituting the styrene acrylic modified polyester resin (A) used in the present invention has a glass transition temperature (Tg) of 35 to 60 ° C. when it is a single styrene acrylic copolymer molecular chain. Is preferable, and the thing of 30-50 degreeC is more preferable. The glass transition temperature is calculated by the FOX equation shown below.

  In the FOX formula, Wx represents the mass fraction of monomer x, and Tgx represents the glass transition temperature of the homopolymer of monomer x. Here, the “compound that forms a structure in which a polyester segment and a styrene acrylic copolymer segment are molecularly bonded” described later is not used when calculating the glass transition temperature.

  The styrene acrylic copolymer segment preferably has a weight average molecular weight (Mw) of 2,000 to 100,000.

  When the styrene acrylic modified polyester resin (A) is produced by the production methods (1) to (3) above, a compound for molecularly bonding the polyester segment and the styrene acrylic copolymer segment is used. In the production method of (1) above, this compound is “a compound having a site capable of reacting with a carboxy group (—COOH) or a hydroxy group (—OH) remaining in a polyester segment and a site capable of reacting with a vinyl monomer”. Is applicable. In addition, in the production method of (2) above, “in addition to the polyvalent carboxylic acid and the polyhydric alcohol, a site capable of reacting with the styrene acrylic copolymer segment and a site capable of reacting with the polyvalent carboxylic acid or polyhydric alcohol are provided. "Compounds with". Furthermore, in the production method of (3) above, it corresponds to “a compound having a site capable of binding to a polyester segment and a site capable of binding to a styrene acrylic copolymer segment”.

  This compound includes a functional group capable of performing a condensation reaction with a carboxy group (—COOH) or a hydroxy group (—OH) remaining in a polyester segment, a carbon-carbon double bond capable of performing an addition reaction with a styrene acrylic copolymer segment, and the like. It is preferable to have an unsaturated structure of Specific examples of such a compound include vinyl compounds having a carboxy group such as acrylic acid, methacrylic acid, fumaric acid and maleic acid, and carboxylic acid anhydrides such as maleic anhydride.

  The amount of the compound used for molecularly bonding the polyester segment and the styrene acrylic copolymer segment is 0.1 to 5 when the total mass of the compound used for forming the styrene acrylic modified polyester resin (A) is 100% by mass. 0.0 mass% is preferable, and 0.5-3.0 mass% is more preferable. Here, the compound used for the formation of the styrene acrylic modified polyester resin (A) includes a polyester segment, a styrene monomer, a (meth) acrylate monomer, and a polyester segment and a styrene acrylic copolymer segment. The compound to be bound.

  In addition, the amount of the styrene monomer and the (meth) acrylic acid ester monomer used when forming the styrene acrylic modified polyester resin (A) used in the present invention is 100% by mass as described above. It is 5-40 mass% in total. That is, it is the range which corresponds with the styrene acrylic content rate mentioned above, This use amount becomes like this. Preferably it is 5-30 mass%, More preferably, it is 10-20 mass%.

  The polyester segment constituting the styrene acrylic modified polyester resin (A) used in the present invention is formed by polycondensation reaction of a known polycarboxylic acid and polyhydric alcohol in the presence of a catalyst. . The polyester segment can be a derivative of the aforementioned polyvalent carboxylic acid or polyhydric alcohol used as a raw material. The polyvalent carboxylic acid derivative includes an alkyl ester, an acid anhydride, or an acid chloride of the polyvalent carboxylic acid. Etc. Polyhydric alcohol derivatives include polyhydric alcohol ester compounds and hydroxycarboxylic acids.

  Hereinafter, specific examples of polyvalent carboxylic acid and polyhydric alcohol that can be used for forming the polyester segment will be described. First, examples of the polyvalent carboxylic acid include known divalent carboxylic acids and trivalent or higher carboxylic acids called aliphatic dicarboxylic acids and aromatic dicarboxylic acids. Specific examples of the divalent carboxylic acid include, for example, oxalic acid, succinic acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecane. Dicarboxylic acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, malic acid, citric acid, malonic acid, pimelic acid, tartaric acid, phthalic acid, isophthalic acid, terephthalic acid Tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, hexahydroterephthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediglycolic acid, p-phenylenediglycolic acid, o-phenylenediglycolic acid, Diphenylacetic acid, diphenyl-p, p'-dicar Phosphate, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracene dicarboxylic acid, and dodecenylsuccinic acid. Specific examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, and pyrenetetracarboxylic acid. These polyvalent carboxylic acids can be used singly or in combination of two or more.

  Among the polyvalent carboxylic acids, it is preferable to use an aliphatic unsaturated dicarboxylic acid having a carbon-carbon unsaturated bond in the molecular structure. This aliphatic unsaturated dicarboxylic acid has a structure in which a polyester segment and a styrene acrylic copolymer segment are molecularly bonded without using the above-mentioned "compound for molecularly bonding a polyester segment and a styrene acrylic copolymer segment". There is a merit that can be formed. Therefore, it is preferable because the number of types of compounds necessary for producing the styrene acrylic-modified polyester resin (A) is reduced, the resin production process is simplified, and the productivity is improved. Of course, even when the aliphatic unsaturated dicarboxylic acid is used, a “compound for molecularly bonding a polyester segment and a styrene acrylic copolymer segment” may be used.

  The aliphatic unsaturated dicarboxylic acid is preferably fumaric acid, maleic acid or mesaconic acid.

  Moreover, it is preferable that the ratio of the aliphatic unsaturated dicarboxylic acid with respect to all the polyvalent carboxylic acids used for polyester segment formation is 25-75 mol%, and it is more preferable that it is 30-60 mol%.

  Next, specific examples of the polyhydric alcohol will be described. Examples of the polyhydric alcohol that can be used to form the polyester segment include known dihydric alcohols and trihydric or higher alcohols. Specific examples of the dihydric alcohol include, for example, ethylene glycol, propylene glycol, butanediol, diethylene glycol, hexanediol, cyclohexanediol, octanediol, decanediol, dodecanediol, ethylene oxide adduct of bisphenol A, and propylene oxide of bisphenol A. Examples include adducts. Specific examples of the trihydric or higher alcohol include glycerin, pentaerythritol, hexamethylol melamine, hexaethylol melamine, tetramethylol benzoguanamine and the like. These polyhydric alcohols can be used alone or in combination of two or more.

  As a method for forming the polyester segment, a conventionally known method for forming a polyester segment by polycondensation reaction between a polycarboxylic acid and a polyhydric alcohol in the presence of a catalyst is employed. A known catalyst can also be used.

Next, the compound which forms a styrene acrylic copolymer segment is demonstrated. The polyester segment constituting the styrene acrylic modified polyester resin (A) used in the present invention is formed by addition polymerization of at least a styrene monomer and a (meth) acrylic acid ester monomer. Styrene monomer as referred to herein, in addition to styrene represented by the structural formula _{CH 2 = CH-C 6 H} 5, is intended to include a structure having a known side-chain or functional groups styrene structure. In addition, the (meth) acrylic acid ester monomer referred to here is an acrylic acid ester derivative or methacrylic acid in addition to the acrylic acid ester compound or methacrylic acid ester compound represented by CH ₂ = CHCOOR (R is an alkyl group). It includes an ester compound having a known side chain or functional group in the structure of an ester derivative or the like.

  Specific examples of the styrene monomer and (meth) acrylate monomer capable of forming a styrene acrylic copolymer segment are shown below, but for the formation of the styrene acrylic copolymer segment used in the present invention. Usable ones are not limited to those shown below.

  First, specific examples of the styrene monomer include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4- Examples thereof include dimethyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, and pn-dodecyl styrene. These styrene monomers can be used alone or in combination of two or more.

  Specific examples of the (meth) acrylic acid ester monomer include, for example, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, and n-acrylate. -Acrylic acid ester monomers such as octyl, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate; methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate , T-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, etc. Methacrylic acid esters, and the like.

  These acrylic acid ester monomers or methacrylic acid ester monomers can be used alone or in combination of two or more. That is, a copolymer is formed using a styrene monomer and two or more acrylate monomers, and a copolymer is formed using a styrene monomer and two or more methacrylic ester monomers. Either a coalescence can be formed, or a copolymer can be formed by using a styrene monomer together with an acrylate monomer and a methacrylic acid ester monomer.

  The method for forming the styrene acrylic copolymer segment is not particularly limited, and examples thereof include a method of polymerizing monomers using a known oil-soluble or water-soluble polymerization initiator. Specific examples of the oil-soluble polymerization initiator include the following azo or diazo polymerization initiators and peroxide polymerization initiators.

  As the azo or diazo polymerization initiator, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1) -Carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and the like.

  As the peroxide polymerization initiator, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, 2,4 -Dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis- (4,4-t-butylperoxycyclohexyl) propane, tris- (t-butylperoxy) triazine and the like.

  Moreover, when forming resin particles by an emulsion polymerization method, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetate, azobiscyanovaleric acid and its salts, hydrogen peroxide, and the like.

<Vinyl resin (B)>
In the vinyl resin (B) used in the present invention, the content of the structural unit derived from the (meth) acrylic acid ester monomer is 40 to 90% by mass, and the weight average molecular weight is 100,000 to 400,000. is there. Here, “(meth) acrylic acid ester monomer” is a general term for “acrylic acid ester monomer” and “methacrylic acid ester monomer”. For example, “(meth) acrylic acid” described later is used. “Methyl” is a generic term for “methyl acrylate” and “methyl methacrylate”.

  Examples of the (meth) acrylate monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, (meth) acrylic acid n-butyl, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, (meth) acrylic acid C 1-8 linear, branched, or cyclic ester moieties such as n-octyl, tert-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth) acrylate Examples include monomers having an alkyl group. These may be used alone or in combination of two or more.

  Among these, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are preferable.

  The vinyl resin (B) contains structural units derived from vinyl monomers other than the (meth) acrylic acid ester monomer. Examples of such vinyl monomers include, for example, styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-chlorostyrene, 3,4-dichlorostyrene, p- Phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, styrene or styrene derivatives such as pn-dodecylstyrene; olefins such as ethylene, propylene, and isobutylene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, and vinylidene fluoride; vinyl propionate , Vinyl acetate, vinyl benzoate and other vinyl esters; Vinyl ethers such as methyl ether and vinyl ethyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone; N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; Vinyl Examples thereof include vinyl compounds such as naphthalene and vinylpyridine; vinyl monomers such as acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide.

  Moreover, what has an ionic dissociation group as a polymerizable monomer can also be used in combination. Examples of the polymerizable monomer having an ionic dissociation group include those having a substituent such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group as a constituent group, specifically, acrylic acid, methacrylic acid, and the like. , Maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, styrene sulfonic acid, allyl sulfosuccinic acid, 2-acrylamido-2-methylpropane sulfonic acid, acid phosphooxy Examples include ethyl methacrylate and 3-chloro-2-acid phosphooxypropyl methacrylate.

  Furthermore, as a polymerizable monomer, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl A vinyl resin (B) having a crosslinked structure can also be obtained by using a multifunctional vinyl such as glycol diacrylate.

  These vinyl monomers can be used alone or in combination of two or more.

  Among these vinyl monomers, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, vinyl propionate, acrylic acid, and methacrylic acid are preferable.

  The content rate of the structural unit derived from the (meth) acrylic acid ester monomer in vinyl resin (B) is 40-90 mass%. That is, by setting the content to 40% by mass or more, good compatibility with the styrene acrylic modified polyester resin (A) is ensured, and gloss of the toner image is suppressed, so that a printed document is produced. Sometimes the glare problem is avoided. Moreover, by setting it as 90 mass% or less, compatibility with a styrene acrylic modified polyester resin (A) is moderately suppressed, and low temperature fixability can be maintained stably.

  Although the content rate of the structural unit derived from the (meth) acrylic acid ester monomer in vinyl resin (B) is 40-90 mass% as mentioned above, Preferably it is 50-80 mass%, More preferably It is 60-75 mass%.

  The vinyl resin (B) has a weight average molecular weight of 100,000 to 400,000. That is, by setting the weight average molecular weight to 100,000 or more, a practical fixing region (a fixing temperature region in which a toner does not cause a low temperature offset or a high temperature offset on the heating member of the fixing device and a sufficient strength as an image is obtained). Sufficient elasticity is obtained, good fixing on the transfer paper is realized, and good toner fixing can be performed even in a low-temperature fixing region. Moreover, by setting it as 400,000 or less, it is moderately suppressed so that the elasticity of the binder resin does not become too high, and stable low-temperature fixability can be achieved.

  The vinyl resin (B) has a weight average molecular weight of 100,000 to 400,000 as described above, preferably 170,000 to 350,000, more preferably 200,00 to 300,000.

  Further, the content of the vinyl resin (B) with respect to the total mass of the resin constituting the toner is preferably 5 to 30% by mass.

  In addition, the weight average molecular weight of a vinyl resin (B) can be measured by the method as described in the below-mentioned Example.

  The method for producing the vinyl resin (B) is not particularly limited, and examples thereof include a suspension polymerization method, a miniemulsion polymerization method, and an emulsion polymerization method in an aqueous solvent.

  Hereinafter, the surfactant, the polymerization initiator, and the chain transfer agent used in the production of the vinyl resin (B) will be described.

[Surfactant]
The surfactant used in the polymerization of the vinyl resin (B) is not particularly limited, but is sulfonate (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate), sulfate ester salt (lauryl sulfate). Sodium, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc., fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, etc.) An ionic surfactant can be illustrated as a suitable thing. Also, polyethylene oxide, polypropylene oxide, combination of polypropylene oxide and polyethylene oxide, ester of polyethylene glycol and higher fatty acid, alkylphenol polyethylene oxide, ester of higher fatty acid and polyethylene glycol, ester of higher fatty acid and polypropylene oxide, sorbitan ester, etc. Nonionic surfactants can also be used. These surfactants are used as an emulsifier when a toner is obtained by an emulsion polymerization method, but may be used for other processes or other purposes. These surfactants can be used alone or in combination of two or more.

(Polymerization initiator)
In the case of using the suspension polymerization method, an oil-soluble radical polymerization initiator can be used. Examples of the oil-soluble radical polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyro Azo or diazo polymerization initiators such as nitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, 2 , 4-Dichlorobenzoyl peroxide, Lauroyl peroxy Polymers having a side chain with a peroxide polymerization initiator or peroxide such as side, 2,2-bis- (4,4-t-butylperoxycyclohexyl) propane, tris- (t-butylperoxy) triazine An initiator etc. can be mentioned.

  In the case of using the miniemulsion polymerization method or the emulsion polymerization method, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble radical polymerization initiator include potassium persulfate, ammonium persulfate, sodium persulfate (peroxodioxide). Persulfates such as sodium sulfate), azobisaminodipropane acetate, azobiscyanovaleric acid and its salts, hydrogen peroxide, and the like.

  These polymerization initiators may be used alone or in combination of two or more.

[Chain transfer agent]
A chain generally used for the purpose of adjusting the molecular weight of the vinyl resin (B) when the toner particles constituting the toner of the present invention are produced by suspension polymerization, miniemulsion polymerization or emulsion polymerization. A transfer agent can be used.

  The chain transfer agent is not particularly limited, and examples thereof include mercaptans such as n-octyl mercaptan, n-decyl mercaptan, tert-dodecyl mercaptan, n-octyl-3-mercaptopropionic acid ester, terpinolene, tetrabromide. Carbon or α-methylstyrene dimer is used. These chain transfer agents can be used alone or in combination of two or more.

  The polymerization temperature and the polymerization time are not particularly limited, but are usually in the temperature range of 65 to 90 ° C. and in the range of 1 to 5 hours.

  The content of the vinyl resin (B) in the binder resin is preferably 3 to 30% by mass, and more preferably 5 to 15% by mass. Within the above range, an electrostatic charge image developing toner capable of fixing at low temperature and obtaining a low gloss image can be obtained. If it is less than 3% by mass, the elastic component is small, and a low gloss image may not be obtained. On the other hand, when it exceeds 30 mass%, there are too many elastic components and there exists a possibility that low temperature fixability may deteriorate.

  The toner base particles containing the binder resin described above have a so-called single layer structure, but the binder resin is used as a core particle, and a resin that forms a shell portion is further added to the surface of the core particle. It is also preferable to form toner base particles having a core-shell structure by agglomeration and fusion. Although it does not restrict | limit especially as resin which forms a shell part, A polyester resin is preferable. By using a polyester resin for the shell portion, a polyester resin having sharp melt properties exists on the surface of the toner particles, so that fixing at a lower temperature is possible.

  Specific examples of the polyester resin forming the shell part include unmodified polyester resin or styrene acrylic modified polyester resin.

  Examples of the unmodified polyester resin include resins having in the molecule only the polyester segment described in the above section <Styrene acrylic modified polyester resin (A)>. Therefore, detailed description is omitted here.

  Examples of the styrene acrylic modified polyester resin include resins having the polyester segment and the styrene acrylic copolymer segment described in <Styrene acrylic modified polyester resin (A)>. Therefore, although detailed description of the monomer used is omitted here, the styrene acrylic content of the styrene acrylic modified polyester resin used in the shell portion is not particularly limited and can be appropriately selected. .

  The content of the shell part is preferably 5 to 30% by mass, where the total resin amount of the core part and the shell part is 100% by mass.

<Other binder resins>
The binder resin of the present invention may contain other resins in addition to the above styrene acrylic modified polyester resin (A) and vinyl resin (B). Examples of other resins include homopolymers of styrene or styrene derivatives such as polystyrene, poly p-chlorostyrene, and polyvinyl toluene; styrene-p-chlorostyrene copolymers, styrene-propylene copolymers, styrene- Vinyl toluene copolymer, styrene-vinyl naphthalene copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-butadiene-acrylonitrile copolymer Styrene copolymers such as polymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyacetic acid Nyl, polyethylene, polypropylene, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorine And paraffin wax. These other resins can be used alone or in combination of two or more.

  The binder resin used in the electrostatic image developing toner of the present invention has been described above. Hereinafter, other components that can be included in the electrostatic image developing toner of the present invention will be described.

〔Release agent〕
Examples of the release agent (offset preventing agent) include hydrocarbon waxes, ester waxes, natural product waxes, and amide waxes.

  Examples of hydrocarbon waxes include low molecular weight polyethylene wax, polypropylene wax, microcrystalline wax, Fischer-Tropsch wax, and paraffin wax.

  Examples of ester waxes include behenyl behenate, ethylene glycol stearate, ethylene glycol behenate, neopentyl glycol stearate, neopentyl glycol behenate, 1,6-hexanediol stearate, 1,6 Higher fatty acids such as hexanediol behenate, glycerine stearate, glycerine behenate, pentaerythritol stearate, pentaerythritol behenate, stearyl citrate, behenyl citrate, stearyl ring acid, and behenyl ring acid Examples include esters with alcohols. These release agents can be used alone or in combination of two or more.

  Melting | fusing point of a mold release agent becomes like this. Preferably it is 40-160 degreeC, More preferably, it is 50-120 degreeC. By setting the melting point within the above range, the heat-resistant storage stability of the toner is ensured, and stable toner image formation can be performed without causing cold offset or the like even when fixing at a low temperature. Further, the content of the release agent in the toner is preferably 1 to 30% by mass, more preferably 5 to 20% by mass.

[Colorant]
In the present invention, a colorant can be used to produce a color toner.

  Colorants that can be used include known inorganic or organic colorants. Hereinafter, specific colorants are shown.

  Examples of the black colorant include carbon black such as furnace black, channel black, acetylene black, thermal black and lamp black, and magnetic powder such as magnetite and ferrite.

  Examples of the colorant for magenta or red include C.I. I. Pigment Red 2, 3, 5, 6, 7, 15, 15, 48: 1, 53: 1, 57: 1, 60, 63, 64, 68, the same 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 139, 144, 149, 150, 163, 166, 170, 177, 178, 184, 202, 206, 207, 209, 222, 238, 269, and the like.

  Examples of the colorant for orange or yellow include C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment yellow 12, 14, 15, 17, 74, 83, 93, 94, 138, 155, 162, 180, 185, and the like.

  Further, examples of the colorant for green or cyan include C.I. I. Pigment Blue 2, 3, 15, 15, 15: 2, 15: 3, 15: 4, 16, 17, 17, 60, 62, 66, C.I. I. And CI Pigment Green 7.

  Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 2, 6, 14, 15, 16, 19, 21, 21, 33, 44, 56, 61, 77, 79, 80, 81, 82, the same 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95 and the like.

  These colorants can be used alone or in combination of two or more as required. When the colorant is used, the addition amount is preferably 1 to 30% by mass and more preferably 2 to 20% by mass with respect to the whole toner. The number average primary particle size of the colorant varies depending on the type, but is preferably about 10 to 200 nm. The number average primary particle size of the colorant can be measured using, for example, a Microtrac particle size distribution measuring device “UPA-150” (manufactured by Nikkiso Co., Ltd.).

  As the colorant, a surface-modified one can also be used. As the surface modifier, conventionally known ones can be used, and specifically, silane coupling agents, titanium coupling agents, aluminum coupling agents and the like can be preferably used.

[Charge control agent]
The toner particles constituting the toner for developing an electrostatic charge image of the present invention may contain a charge control agent as necessary. As the charge control agent, various known ones that can be dispersed in an aqueous medium can be used. Specific examples include nigrosine dyes, naphthenic acid or higher fatty acid metal salts, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof. The charge control agent particles preferably have a number average primary particle diameter of about 10 to 500 nm in a dispersed state.

[Particle size of toner particles]
The particle diameter of the toner for developing an electrostatic charge image of the present invention is preferably 3 to 8 μm in terms of the median diameter (D ₅₀ ) based on the number. In the production method described later, the particle size can be controlled by the concentration of the flocculant, the addition amount of the organic solvent, the fusing time, and further the composition of the polymer itself.

When the median diameter (D ₅₀ ) on the basis of the number is 3 to 8 μm, reproducibility of fine lines and high quality of photographic images can be achieved, and toner consumption can be reduced when a large particle size toner is used. Can be reduced. The median diameter can be measured by, for example, “Multisizer 3” (manufactured by Beckman Coulter).

[Average circularity of toner particles]
The electrostatic charge image developing toner of the present invention preferably has an average circularity represented by the following formula 1 of 0.920 to 1.000, preferably 0.940 to 0.995, from the viewpoint of improving transfer efficiency. More preferably.

  The average circularity can be measured using, for example, an average circularity measuring device “FPIA-2100” (manufactured by Sysmex).

(External additive)
The external additive used in the present invention is not particularly limited, but particles such as inorganic fine particles having a number average primary particle size of about 4 to 800 nm and organic fine particles having a number average primary particle size of about 10 to 2000 nm are preferable. The type of the external additive is not particularly limited, and examples thereof include known inorganic fine particles and organic fine particles exemplified below, and lubricants. These external additives can be used alone or in combination of two or more.

  As the inorganic fine particles, conventionally known fine particles can be used. For example, silica, titania, alumina, strontium titanate fine particles and the like are preferable. Moreover, what hydrophobized these inorganic fine particles can also be used as needed.

  Specific examples of silica fine particles include, for example, commercially available products R-805, R-976, R-974, R-972, R-812, R-809 manufactured by Nippon Aerosil Co., Ltd., HVK-2150 manufactured by Hoechst, H-200, commercially available products TS-720, TS-530, TS-610, H-5, MS-5 and the like manufactured by Cabot Corporation can be mentioned.

  As titania fine particles, for example, commercially available products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., commercially available products MT-100S, MT-100B, MT-500BS, MT-600, MT-600SS manufactured by Teika Corporation, JA-1, commercial products manufactured by Fuji Titanium Industry Co., Ltd. TA-300SI, TA-500, TAF-130, TAF-510, TAF-510T, commercial products manufactured by Idemitsu Kosan Co., Ltd. IT-S, IT-OA, IT -OB, IT-OC, etc. are included.

  Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd., and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

  As the organic fine particles, specifically, homopolymers such as styrene and methyl methacrylate and copolymers thereof can be used.

  Further, it is possible to use a lubricant to further improve the cleaning property and the transfer property. For example, there are metal salts of higher fatty acids as follows. That is, salts of zinc stearate, aluminum, copper, magnesium, calcium, etc., zinc oleate, salts of manganese, iron, copper, magnesium, etc., zinc palmitate, salts of copper, magnesium, calcium, etc., linoleic acid And salts of zinc and calcium of ricinoleic acid.

  The addition amount of these external additives is preferably 0.1 to 10.0% by mass with respect to the whole toner.

(Developer)
The electrostatic image developing toner of the present invention can be used as a magnetic or non-magnetic one-component developer, but it is used as a two-component developer toner (two-component developer) mixed with a carrier. Also good. When the electrostatic image developing toner of the present invention is used as a one-component developer, a magnetic one-component developer containing non-magnetic one-component developer or about 0.1 to 0.5 μm magnetic particles in the toner. Any developer can be used, and any of them can be used. In addition, when the toner for developing an electrostatic charge image of the present invention is used as a two-component developer, examples of carriers include metals such as iron, ferrite, and magnetite, alloys of these metals with metals such as aluminum and lead, and the like. Magnetic particles made of conventionally known materials can be used, and ferrite particles are particularly preferable.

  As the coating resin constituting the coat carrier, those showing a positive charge relative to the toner are preferable. For example, olefin resin, styrene resin, acrylic resin, styrene-acrylic resin, silicone resin, ester resin And fluorine-containing polymer resins. The resin constituting the resin-dispersed carrier is not particularly limited, and known resins can be used. For example, acrylic resin, styrene-acrylic resin, polyester resin, fluororesin, phenol resin, etc. are used. can do.

  A preferable carrier is a coated carrier coated with an acrylic resin as a coating resin, from the viewpoint of preventing external additives from being detached and durability.

The carrier preferably has a volume-based median diameter (D ₅₀ ) of 20 to 100 μm, more preferably 25 to 80 μm. The volume-based median diameter (D ₅₀ ) of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser. it can.

<Method for producing toner for developing electrostatic image>
Next, a method for producing the toner for developing an electrostatic charge image of the present invention will be described.

  Specifically, an emulsion association method in which resin particles are formed in advance and the resin particles are aggregated and fused to form toner particles is preferable. In the emulsion association method, core particles having a smooth surface can be produced by controlling the conditions of the resin particle aggregation / fusion process and the subsequent aging process.

  Hereinafter, an example of producing a toner for developing an electrostatic charge image by an emulsion association method will be described. In the emulsion association method, a toner is generally prepared through the following steps.

(A) The process of obtaining the dispersion liquid of the styrene acrylic modified polyester (A) whose styrene acrylic content rate is 5-40 mass% (b) The content rate of the structural unit derived from the (meth) acrylic acid ester monomer is 40. A step of obtaining a dispersion of vinyl resin (B) having a weight average molecular weight of 100,000 to 400,000 (c) a dispersion of the styrene acrylic modified polyester (A), and the vinyl resin A step of mixing the dispersion of (B) and aggregating the styrene acrylic modified polyester (A) and the vinyl resin (B) to obtain binder resin particles (aggregation / fusion step)
(D) Cooling step (e) Filtration, washing, drying step (f) External additive treatment step When the toner base particles have a core-shell structure, the binder resin particles (core particles) are added after the step (c). It is preferable to further include a step of forming a shell by aggregating the polyester resin on the surface.

  Hereinafter, each step will be described.

(A) Step of obtaining a dispersion of styrene acrylic modified polyester resin (A) In this step, the styrene acrylic modified polyester resin (A) having a styrene acrylic content of 5 to 40% by mass obtained by the production method described above. To obtain a dispersion.

  The method for obtaining the dispersion is not particularly limited. For example, after pulverizing the styrene acrylic-modified polyester resin (A) as necessary, the dispersion is obtained in an aqueous medium using an ultrasonic homogenizer in the presence of a surfactant. A method of dispersing the styrene acrylic modified polyester resin (A) is mentioned.

  Here, the said aqueous medium means that a main component (50 mass% or more) consists of water. Examples of components other than water include organic solvents that dissolve in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Of these, alcohol-based organic solvents such as methanol, ethanol, isopropanol, and butanol, which are organic solvents that do not dissolve the resin, are particularly preferable.

  Examples of the surfactant include sulfonates such as sodium lauryl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, and sodium octyl sulfate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, Examples include fatty acid salts such as potassium stearate and calcium oleate.

  Nonionic surfactants can also be used. Specifically, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, esters of polyethylene glycol and higher fatty acids, alkylphenol polyethylene oxide, higher fatty acids and Examples include polyethylene glycol esters, higher fatty acid and polypropylene oxide esters, and sorbitan esters.

  The usage-amount of surfactant is 0.1-5.0 mass% normally with respect to a styrene acrylic modified polyester resin (A).

(B) The process of obtaining the dispersion liquid of the vinyl resin (B) whose content rate of a (meth) acrylic acid ester monomer is 40-90 mass% and whose weight average molecular weight is 100,000-400,000. Then, the dispersion of the vinyl resin (B) whose content rate of a (meth) acrylic acid ester monomer is 40-90 mass% and whose weight average molecular weight is 100,000-400,000 is obtained. When the polymerization of the vinyl resin (B) is performed in an aqueous medium, the liquid after the polymerization reaction can be used as it is as a dispersion of the vinyl resin (B).

  Alternatively, the isolated vinyl resin (B) is pulverized as necessary, and then the vinyl resin (B) is dispersed in an aqueous medium using an ultrasonic disperser in the presence of a surfactant. Also good. Specific examples of the aqueous medium and the surfactant are the same as described above, and thus the description thereof is omitted here.

  In the electrostatic image developing toner of the present invention, when a colorant is used, a colorant particle dispersion is prepared by dispersing the colorant in an aqueous medium in advance before the step (c) described later. It is preferable to keep it. Examples of the disperser used for the dispersion treatment of the colorant include a pressure disperser such as an ultrasonic homogenizer, a mechanical homogenizer, a manton gourin, a pressure discharge homogenizer, a medium grinder such as a sand grinder, a Getzmann mill, and a diamond fine mill. A known dispersing machine such as a machine can be used.

  The colorant particles may be surface-modified as described above. Specifically, the colorant fine particles are dispersed in a solvent, the surface modifier is added to the dispersion, and the temperature of the system is increased. To react. After completion of the reaction, the colorant particles are separated by filtration, washed and filtered with the same solvent, and dried to obtain colorant particles treated with the surface modifier.

(C) A dispersion of the styrene acrylic modified polyester (A) and a dispersion of the vinyl resin (B) are mixed, and the styrene acrylic modified polyester (A) and the vinyl resin (B) are aggregated to form a binder resin. In this step, the above-mentioned styrene acrylic modified polyester resin (A) particles and vinyl resin (B) particles and, if necessary, colorant particles are aggregated in an aqueous medium, and at the same time, these particles are aggregated. In this step, the binder resin is obtained by fusing. In this step, an alkali metal salt, an alkaline earth metal salt, or the like is added to an aqueous medium in which styrene acrylic-modified polyester resin (A) particles and vinyl resin (B) particles and, if necessary, colorant particles are mixed. After adding as a flocculant, aggregation is advanced by heating at a temperature equal to or higher than the glass transition temperature of the styrene acrylic modified polyester resin (A) particles and vinyl resin (B) particles, and at the same time, the resin particles are fused.

  Specifically, the dispersion of the styrene acrylic modified polyester resin (A) and the dispersion of the vinyl resin (B) prepared in the above-described procedure and a colorant particle dispersion as necessary are mixed, and magnesium chloride is prepared. By adding an aggregating agent such as styrene acryl-modified polyester resin (A) particles and vinyl resin (B) particles, and if necessary, colorant particles are agglomerated and the particles are fused and bound together. A resin is formed. When the size of the aggregated particles reaches a target size, a salt such as saline is added to stop the aggregation.

  The flocculant used in this step is not particularly limited, but one selected from metal salts is preferably used. For example, monovalent metal salts such as alkali metal salts such as sodium, potassium and lithium, for example, divalent metal salts such as calcium, magnesium, manganese and copper, and trivalent metals such as iron and aluminum. There is salt. Specific examples of the salt include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, and manganese sulfate. Among these, divalent metal is particularly preferable. It is salt. When a divalent metal salt is used, agglomeration can be promoted with a smaller amount. These flocculants can be used alone or in combination of two or more.

  In the flocculation step, it is preferable that the standing time (time until heating is started) to be left after adding the flocculant is as short as possible. That is, after adding the flocculant, it is preferable to start heating the flocculating dispersion liquid as quickly as possible so as to be equal to or higher than the glass transition points of the styrene acrylic modified polyester resin (A) and the vinyl resin (B). The reason for this is not clear, but there is a possibility that the aggregation state of the particles fluctuates with the passage of the standing time, and the particle size distribution of the obtained toner particles becomes unstable or the surface property fluctuates. Because there is. The standing time is usually within 30 minutes, preferably within 10 minutes. The temperature at which the flocculant is added is not particularly limited, but is preferably equal to or lower than the glass transition temperature of the styrene acrylic modified polyester resin (A) and the vinyl resin (B) which are the binder resins.

  Further, in the aggregation step, it is preferable to quickly raise the temperature by heating after adding the aggregating agent, and the rate of temperature rise is preferably 0.8 ° C./min or more. The upper limit of the heating rate is not particularly limited, but is preferably 15 ° C./min or less from the viewpoint of suppressing the generation of coarse particles due to rapid progress of fusion. Further, after the dispersion liquid for aggregation reaches a temperature equal to or higher than the glass transition temperature, the temperature of the dispersion liquid for aggregation is maintained for a certain period of time, preferably until the volume-based median diameter is 4.5 to 7.0 μm. Therefore, it is important to continue the fusion (first aging step). Moreover, it is preferable to measure the average circularity of the particles during aging, and to carry out the first aging step until it becomes preferably 0.920 to 1.000.

  As a result, particle growth (aggregation of styrene acrylic-modified polyester resin particles, vinyl resin particles, and, if necessary, colorant particles) and fusion (disappearance of the interface between the particles) can be effectively advanced. The durability of the toner particles finally obtained can be improved.

  When obtaining a binder resin having a core-shell structure, an aqueous dispersion of a polyester resin that forms a shell portion is further added in the first ripening step, and the single-layer structure obtained above is bound. A polyester resin is aggregated and fused on the surface of resin particles (core particles). Thereby, a binder resin having a core-shell structure is obtained (shell forming step). At this time, following the shelling step, it is preferable to further heat-treat the reaction system until the aggregation and fusion of the shell to the surface of the core particles is further strengthened and the shape of the particles becomes a desired shape. Aging process). This second ripening step may be performed until the average circularity of the toner particles having the core-shell structure falls within the range of the average circularity.

  The dispersion in the aggregation process may contain known additives such as a dispersion stabilizer, a release agent (offset preventing agent), a surfactant, and a charge control agent as additives. These additives may be added in this step as an additive dispersion, or may be contained in a dispersion of colorant particles or a dispersion of a binder resin. Specific examples of the release agent, the surfactant, and the charge control agent are as described above, and thus the description thereof is omitted here.

  The dispersion stabilizer plays a role of stably dispersing a toner material such as a binder resin in an aqueous medium. Examples of the dispersion stabilizer include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, Examples include barium sulfate, bentonite, silica, and alumina. In addition, polyvinyl alcohol, gelatin, methylcellulose, sodium dodecylbenzenesulfonate, ethylene oxide adduct, higher alcohol sodium sulfate and the like which are generally used as surfactants can also be used as the dispersion stabilizer. These dispersion stabilizers can be used alone or in combination of two or more.

(D) Cooling Step This cooling step is a step of cooling the above-mentioned dispersion of toner particles. The cooling rate in the cooling treatment is not particularly limited, but is preferably 0.2 to 20 ° C./min. The cooling treatment method is not particularly limited, and examples thereof include a method of cooling by introducing a refrigerant from the outside of the reaction vessel, and a method of cooling by directly introducing cold water into the reaction system.

(E) Filtration, washing, and drying step In the filtration step, the toner particles are separated from the toner particle dispersion. Examples of the filtration method include a centrifugal separation method, a vacuum filtration method using Nutsche and the like, and a filtration method using a filter press and the like, and are not particularly limited.

  Next, deposits such as a surfactant and an aggregating agent are removed from the toner particles (cake-like aggregate) separated by washing in the washing step. The washing treatment is a washing treatment until the electrical conductivity of the filtrate reaches, for example, a level of 5 to 10 μS / cm.

  In the drying process, the toner particles that have been subjected to the cleaning process are subjected to a drying process. Examples of the dryer used in this drying step include known dryers such as spray dryers, vacuum freeze dryers, and vacuum dryers, stationary shelf dryers, mobile shelf dryers, fluidized bed dryers, rotating dryers. It is also possible to use a type dryer, a stirring type dryer or the like. The amount of water contained in the dried toner particles is preferably 5% by mass or less, more preferably 2% by mass or less.

  Further, when the dried toner particles are agglomerated with a weak interparticle attractive force, a crushing process may be performed. As the crushing treatment apparatus, a mechanical crushing apparatus such as a jet mill, a Henschel mixer, a coffee mill, or a food processor can be used.

(F) External additive treatment step This step is a step for preparing a toner by adding and mixing external additives as necessary to the surface of the dried toner base particles. As described above, the addition of the external additive improves the fluidity and chargeability of the toner, and improves the cleaning property.

  Examples of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

Example 1
<Synthesis of styrene acrylic modified polyester resin>
To a 10 liter four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple,
Bisphenol A propylene oxide 2-mole adduct 500 parts by mass Terephthalic acid 117 parts by mass Fumaric acid 81 parts by mass Tin octylate (esterification catalyst) 2 parts by mass are charged, and a polycondensation reaction is performed at 230 ° C. for 8 hours. The polycondensation reaction was continued at 8 kPa for 1 hour and then cooled to 160 ° C. to produce a polyester.

Next, 10 parts by weight of acrylic acid was added at a temperature of 160 ° C., mixed and held for 15 minutes,
Acrylic acid 10 parts by mass Styrene 142 parts by mass n-butyl acrylate 36 parts by mass Di-t-butyl peroxide (polymerization initiator) A mixture of 10 parts by mass was dropped with a dropping funnel over 1 hour. After the dropwise addition, an addition polymerization reaction was performed for 1 hour while maintaining the temperature at 160 ° C., and then the temperature was raised to 200 ° C. and held at 10 kPa for 1 hour. By removing acrylic acid, styrene, and butyl acrylate, a “styrene acrylic-modified polyester resin (1)” was obtained.

<Preparation of aqueous dispersion of styrene acrylic modified polyester resin particles>
100 parts by mass of the above-mentioned “styrene acrylic modified polyester resin (1)” was pulverized with “Landel mill type: RM” (manufactured by Deoksugaku Kogyo Co., Ltd.) and 638 parts by mass of a 0.26% by mass aqueous sodium lauryl sulfate solution prepared in advance. And ultrasonically dispersing with V-LEVEL, 300 μA for 30 minutes using an ultrasonic homogenizer “US-150T” (manufactured by Nippon Seiki Seisakusho). As a result, “an aqueous dispersion (1) of styrene-acrylic modified polyester resin particles” in which styrene-acrylic modified polyester resin (1) particles having a volume-based median diameter (D ₅₀ ) of 160 nm were dispersed was obtained.

<Preparation of aqueous dispersion of vinyl resin>
In a flask equipped with a stirrer, 3100 parts by mass of ion-exchanged water in which 5 parts by mass of sodium peroxodisulfate and 2 parts by mass of sodium lauryl sulfate were dissolved was heated to 80 ° C. and stirred. after that,
Methyl methacrylate 408 parts by mass Styrene 200 parts by mass n-butyl acrylate 152 parts by mass A monomer solution consisting of 40 parts by mass of methacrylic acid was added dropwise over 2 hours. After completion of the dropping, polymerization was carried out by heating and stirring for 3 hours. Then, it cooled to 28 degreeC and obtained "the aqueous dispersion (1) of a vinyl resin."

  It was 85 nm when the particle diameter of the aqueous dispersion (1) of the obtained vinyl resin was measured using the microtrack particle size distribution measuring apparatus "UPA-150" (made by Nikkiso Co., Ltd.).

  Moreover, it was 240,000 when the weight average molecular weight (Mw) was measured using the gel permeation chromatography (GPC) (807-IT type | mold, JASCO Corporation make). The GPC measurement method is as follows.

While maintaining the column temperature at 40 ° C., tetrahydrofuran (THF) as a carrier solvent was flowed at a flow rate of 1 kg / cm ² , 30 mg of a sample to be measured was dissolved in 10 ml of THF, and 0.5 mg of this solution was mixed with the above carrier solvent in the apparatus. And calculated by polystyrene conversion.

<Preparation of colorant particle dispersion>
90 parts by mass of sodium lauryl sulfate was stirred and dissolved in 1600 parts by mass of ion-exchanged water. While stirring this solution, 420 parts by mass of carbon black “Mogal L” (manufactured by Cabot Corp.) was gradually added, and then the stirring device “Claremix (registered trademark)” (manufactured by M Technique Co., Ltd.) was used. By performing the dispersion treatment, “colorant particle dispersion liquid (1)” was prepared. The particle diameter of this dispersion was measured using a Microtrac particle size distribution analyzer “UPA-150” (manufactured by Nikkiso Co., Ltd.), and was 117 nm.

<Preparation of release agent particle dispersion>
While heating 10 parts by mass of sodium lauryl sulfate, 30 parts by mass of paraffin wax (melting point: 80 ° C.), and 80 parts by mass of ion-exchanged water to 95 ° C. with a homogenizer (Ultra Turrax T50, manufactured by IKA), a pressure discharge type homogenizer (Gorin homogenizer, manufactured by Gorin Co., Ltd.) was subjected to a dispersion treatment to prepare a “release agent particle dispersion (1)”. The volume-based median diameter (D ₅₀ ) of the release agent particles in the obtained dispersion was 280 nm. Thereafter, ion-exchanged water was added to adjust the solid content concentration of the dispersion to 20% by mass.

<Production of single-layer toner>
[Aggregation / fusion process]
In a reaction vessel equipped with a stirrer, a temperature sensor, and a cooling tube, 324 parts by mass of “aqueous dispersion of styrene acrylic modified polyester resin particles (1)” in terms of solid content, “aqueous dispersion of vinyl resin (1)” Was added 81 parts by mass in terms of solids, 45 parts by mass of “release agent fine particle dispersion (1)”, and 2000 parts by mass of ion-exchanged water, and then 5 mol / liter sodium hydroxide aqueous solution was added. The pH was adjusted to 10 by adding.

Thereafter, 40 parts by mass of “colorant particle dispersion (1)” was added in terms of solid content. Next, an aqueous solution obtained by dissolving 60 parts by mass of magnesium chloride in 60 parts by mass of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. Thereafter, the temperature increase was started, the system was heated to 80 ° C. over 60 minutes, and the particle growth reaction was continued while maintaining the temperature at 80 ° C. In this state, the particle size of the associated particles was measured with “Multisizer 3” (manufactured by Beckman Coulter), and when the median diameter (D ₅₀ ) on a volume basis reached 6.0 μm, 190 parts by mass of sodium chloride Was added to an aqueous solution of 760 parts by mass of ion-exchanged water to stop the particle growth. After stirring at 80 ° C. for 1 hour, the temperature is further raised, and the mixture is heated and stirred at 90 ° C. to advance the fusion of the particles, thereby measuring the average circularity of the toner “FPIA-2100” (Sysmex Corporation). (The number of detected HPFs is 4000), and when the average circularity reached 0.945, the mixture was cooled to 30 ° C. to obtain “toner base particle dispersion (1)”.

[Filtering, washing and drying process]
The particles ("toner base particle dispersion (1)") prepared in the above aggregation / fusion process were subjected to solid-liquid separation with a centrifuge to form a wet cake of toner base particles. The wet cake was washed with ion-exchanged water at 35 ° C. until the electric conductivity of the filtrate reached 5 μS / cm with the centrifuge, and then transferred to “flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.)”. Was dried until the content became 0.5% by mass to prepare “toner base particles (1)”.

[External additive treatment process]
1% by mass of hydrophobic silica (number average primary particle size = 12 nm) and 0.3% by mass of hydrophobic titania (number average primary particle size = 20 nm) are added to the above “base particles for toner (1)”. “Toner 1” was produced by mixing with a Henschel mixer.

<Creation of carrier>
1000 parts by mass of ferrite core and 50 parts by mass of copolymer resin particles of cyclohexyl methacrylate / methyl methacrylate (copolymerization ratio 5/5) are put into a high-speed mixer equipped with stirring blades, and stirred and mixed at 120 ° C. for 30 minutes. By forming a resin coat layer on the surface of the ferrite core by the action of mechanical impact force, a carrier having a volume-based median diameter (D ₅₀ ) of 50 μm was obtained.

  The volume-based median diameter of the carrier was measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by Sympathec) equipped with a wet disperser.

<Manufacture of two-component developer>
“Toner 1” is added to the above carrier so that the toner concentration becomes 6% by mass, and mixed with a micro type V-type mixer (manufactured by Tsutsui Rika Kikai Co., Ltd.) at a rotational speed of 45 rpm for 30 minutes. Agent 1 ”was produced.

(Example 2)
“Toner 2” and “Developer 2” were produced in the same manner as in Example 1 except that the amount of sodium peroxodisulfate used in <Preparation of aqueous dispersion of vinyl resin> was 10 parts by mass. did.

(Example 3)
“Toner 3” and “Developer 3” were produced in the same manner as in Example 1 except that the amount of sodium peroxodisulfate used in <Preparation of aqueous dispersion of vinyl resin> was 3 parts by mass. did.

Example 4
In the same manner as in Example 1 except that the amount of styrene used in <Synthesis of styrene acrylic modified polyester resin> was 30 parts by mass and the amount of n-butyl acrylate used was 7 parts by mass, 4 "and" Developer 4 "were produced.

(Example 5)
In the same manner as in Example 1, except that the amount of styrene used in <Synthesis of Styrene Acrylic Modified Polyester Resin> was 372 parts by mass and the amount of n-butyl acrylate used was 93 parts by mass. 5 "and" Developer 5 "were produced.

(Example 6)
“Toner 6” was prepared in the same manner as in Example 1 except that the amount of methyl methacrylate used was 168 parts by mass and the amount of styrene was 440 parts by mass in the above <Preparation of aqueous dispersion of vinyl resin>. And “Developer 6”.

(Example 7)
“Toner 7” was prepared in the same manner as in Example 1 except that the amount of methyl methacrylate used in <Preparation of aqueous dispersion of vinyl resin> was 568 parts by mass and the amount of styrene was 40 parts by mass. And “Developer 7”.

(Example 8)
The amount of the “aqueous dispersion (1) of styrene acrylic-modified polyester resin particles” used in <Preparation of single-layer toner> is 385 parts by mass in terms of solid content, and the “aqueous dispersion of vinyl resin (1)” “Toner 8” and “Developer 8” were produced in the same manner as in Example 1 except that the amount used was 20 parts by mass in terms of solid content.

Example 9
The amount of “aqueous dispersion (1) of styrene acrylic-modified polyester resin particles” used in <Preparation of single-layer toner> is 284 parts by mass in terms of solid content, and the “aqueous dispersion of vinyl resin (1)” “Toner 9” and “Developer 9” were produced in the same manner as in Example 1 except that the amount used was 122 parts by mass in terms of solid content.

(Example 10)
The amount of “aqueous dispersion (1) of styrene acrylic modified polyester resin particles” used in <Preparation of single-layer toner> is 393 parts by mass in terms of solid content, and “aqueous dispersion of vinyl resin (1)” “Toner 10” and “Developer 10” were produced in the same manner as in Example 1 except that the amount used was 12 parts by mass in terms of solid content.

(Example 11)
The amount of “aqueous dispersion (1) of styrene acrylic-modified polyester resin particles” used in <Preparation of single-layer toner> is 263 parts by mass in terms of solid content, and “aqueous dispersion of vinyl resin (1)” “Toner 11” and “Developer 11” were produced in the same manner as in Example 1 except that the amount used was 142 parts by mass in terms of solid content.

(Example 12)
<Preparation of core-shell toner>
[Aggregation / fusion process (part 1) (core particle production)]
In a reaction vessel equipped with a stirrer, a temperature sensor, and a cooling tube, 243 parts by mass of the above-mentioned “aqueous dispersion of styrene acrylic-modified polyester resin particles (1)” in terms of solid content and “aqueous dispersion of vinyl resin (1)”. Was added in an amount of 81 parts by mass in terms of solids, 45 parts by mass in terms of solid content (W1), and 2000 parts by mass of ion-exchanged water. The pH was adjusted to 10 by addition.

Then, 40 parts by mass of “colorant particle dispersion (1)” was added in terms of solid content. Next, an aqueous solution in which 60 parts by mass of magnesium chloride was dissolved in 60 parts by mass of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. Thereafter, the temperature increase was started, and the system was heated to 80 ° C. over 60 minutes and maintained at 80 ° C. In this state, the particle size of the associated particles was measured with “Multisizer 3” (manufactured by Beckman Coulter, Inc.), and the particle growth reaction was performed until the median diameter (D ₅₀ ) on a volume basis was 6.0 μm.

[Aggregation / fusion process (Part 2) (shelling)]
When the median diameter (D ₅₀ ) on the volume basis reached 6.0 μm, 81 parts by mass of “aqueous dispersion (1) of styrene acrylic modified polyester resin particles” was charged in terms of solid content. After stirring for 2 hours as it was, an aqueous solution in which 190 parts by mass of sodium chloride was dissolved in 760 parts by mass of ion-exchanged water was added to stop particle growth. The temperature is further raised, and the particles are fused by heating and stirring at 90 ° C., and the average circularity measuring device “FPIA-2100” (manufactured by Sysmex) is used (HPF detection number). 4000), and when the average circularity reached 0.945, it was cooled to 30 ° C. to prepare “Toner Base Particle Dispersion (12)”.

[Filtering, washing and drying process]
The particles ("toner base particle dispersion (12)") prepared in the above aggregation / fusion process were subjected to solid-liquid separation with a centrifugal separator to form a toner base particle wet cake. The wet cake was washed with ion-exchanged water at 35 ° C. until the electric conductivity of the filtrate reached 5 μS / cm with the centrifuge, and then transferred to “flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.)”. Was dried until the content became 0.5% by mass to produce “toner base particles (12)”.

[External additive treatment process]
1% by mass of hydrophobic silica (number average primary particle size = 12 nm) and 0.3% by mass of hydrophobic titania (number average primary particle size = 20 nm) are added to the above “base particles for toner (12)”. “Toner 12” was produced by mixing with a Henschel mixer.

  Further, “Developer 12” was produced in the same manner as Example 1 using “Toner 12”.

(Example 13)
“Toner 13” and “Developer 13” were produced in the same manner as in Example 12 except that the amount of sodium peroxodisulfate used in <Preparation of aqueous dispersion of vinyl resin> was 10 parts by mass. did.

(Example 14)
“Toner 14” and “Developer 14” were produced in the same manner as in Example 12 except that the amount of sodium peroxodisulfate used in <Preparation of aqueous dispersion of vinyl resin> was 3 parts by mass. did.

(Example 15)
In the same manner as in Example 12, except that the amount of styrene used in <Synthesis of styrene acrylic modified polyester resin> was 30 parts by mass and the amount of n-butyl acrylate used was 7 parts by mass. 15 "and" Developer 15 "were produced.

(Example 16)
“Toner” was prepared in the same manner as in Example 12 except that the amount of styrene used in <Synthesis of styrene acrylic modified polyester resin> was 226 parts by mass and the amount of n-butyl acrylate was 57 parts by mass. 16 "and" Developer 16 "were produced.

(Example 17)
“Toner 17” was prepared in the same manner as in Example 12 except that the amount of methyl methacrylate used was 168 parts by mass and the amount of styrene was 440 parts by mass in the above <Preparation of aqueous dispersion of vinyl resin>. And “Developer 17”.

(Example 18)
“Toner 18” was prepared in the same manner as in Example 12 except that the amount of methyl methacrylate used in <Preparation of aqueous dispersion of vinyl resin> was 568 parts by mass and the amount of styrene was 40 parts by mass. And “Developer 18” were produced.

(Example 19)
The amount of the “aqueous dispersion (1) of styrene acrylic modified polyester resin particles” used in [Aggregation / fusion process (part 1) (core particle preparation)] in <Preparation of core-shell toner> is 304 in terms of solid content. “Toner 19” and “Developer 19” were prepared in the same manner as in Example 12 except that the amount of the “vinyl resin aqueous dispersion (1)” was 81 parts by mass in terms of solid content. Was manufactured.

(Example 20)
The amount of “aqueous dispersion (1) of styrene acrylic modified polyester resin particles” used in [Aggregation / fusion process (part 1) (core particle preparation)] in <Preparation of core-shell toner> is 203 in terms of solid content. “Toner 20” and “Developer 20” were prepared in the same manner as in Example 12 except that the amount of the “vinyl resin aqueous dispersion (1)” was 81 parts by mass in terms of solid content. Was manufactured.

(Example 21)
The amount of “aqueous dispersion (1) of styrene acrylic-modified polyester resin particles” used in [Aggregation / fusion process (part 1) (core particle preparation)] in <Preparation of core-shell toner> is 312 in terms of solid content. “Toner 21” and “Developer 21” were prepared in the same manner as in Example 12, except that the amount of the “vinyl resin aqueous dispersion (1)” was 12 parts by mass in terms of solid content. Was manufactured.

(Example 22)
The amount of “aqueous dispersion (1) of styrene acrylic-modified polyester resin particles” used in [Aggregation / fusion process (Part 1) (Core particle preparation)] in <Preparation of core-shell toner> is 182 in terms of solid content. “Toner 22” and “Developer 22” were prepared in the same manner as in Example 12, except that the amount of the aqueous dispersion of vinyl resin (1) was 142 parts by mass in terms of solid content. Was manufactured.

(Comparative Example 1)
“Toner 23” and “Developer 23” were produced in the same manner as in Example 1 except that the amount of sodium peroxodisulfate used in <Preparation of aqueous dispersion of vinyl resin> was 25 parts by mass. did.

(Comparative Example 2)
“Toner 24” and “Developer 24” were prepared in the same manner as in Example 1 except that the amount of sodium peroxodisulfate used in <Preparation of aqueous dispersion of vinyl resin> was 2.5 parts by mass. Manufactured.

(Comparative Example 3)
“Toner” was prepared in the same manner as in Example 1 except that the amount of styrene used in <Synthesis of Styrene Acrylic Modified Polyester Resin> was 12 parts by mass and the amount of n-butyl acrylate was 3 parts by mass. 25 "and" Developer 25 "were produced.

(Comparative Example 4)
“Toner” was prepared in the same manner as in Example 1 except that the amount of styrene used in <Synthesis of styrene acrylic modified polyester resin> was 568 parts by mass and the amount of n-butyl acrylate was 142 parts by mass. 26 "and" Developer 26 "were produced.

(Comparative Example 5)
“Toner 27” was prepared in the same manner as in Example 1 except that the amount of methyl methacrylate used was 88 parts by mass and the amount of styrene was 520 parts by mass in the above <Preparation of aqueous dispersion of vinyl resin>. And “Developer 27” were produced.

(Comparative Example 6)
“Toner 28” and “Development” were carried out in the same manner as in Example 1 except that the amount of methyl methacrylate used in <Preparation of aqueous dispersion of vinyl resin> was 608 parts by mass and styrene was not used. Agent 28 "was produced.

(Comparative Example 7)
“Toner 29” and “Developer 29” were produced in the same manner as in Example 8 except that the amount of sodium peroxodisulfate used in <Preparation of aqueous dispersion of vinyl resin> was 25 parts by mass. did.

(Comparative Example 8)
“Toner 30” and “Developer 30” were prepared in the same manner as in Example 8 except that the amount of sodium peroxodisulfate used in <Preparation of aqueous dispersion of vinyl resin> was 2.5 parts by mass. Manufactured.

(Comparative Example 9)
“Toner” was prepared in the same manner as in Example 8 except that the amount of styrene used in <Synthesis of Styrene Acrylic Modified Polyester Resin> was 12 parts by mass and the amount of n-butyl acrylate was 3 parts by mass. 31 "and" Developer 31 "were produced.

(Comparative Example 10)
“Toner” was prepared in the same manner as in Example 8 except that the amount of styrene used in <Synthesis of styrene acrylic modified polyester resin> was 568 parts by mass and the amount of n-butyl acrylate was 142 parts by mass. 32 "and" Developer 32 "were produced.

(Comparative Example 11 )
“Toner 34” and “Development” were carried out in the same manner as in Example 12 except that the amount of methyl methacrylate used in <Preparation of aqueous dispersion of vinyl resin> was 608 parts by mass and styrene was not used. Agent 34 "was produced.

≪Evaluation≫
<Low-temperature fixability evaluation>
Evaluation of the low-temperature fixability was performed by introducing the developer obtained in each Example and each Comparative Example into a commercially available color multifunction peripheral “bizhub PRO 1200” (manufactured by Konica Minolta Business Technologies, Inc.), at room temperature and normal humidity environment (temperature A toner image in which an image of 1 cm square with a toner adhesion amount of 3 g / m ² (one place in the center) is formed on high-quality paper (64 g / m ² ) of A4 size in an environment of 20 ° C. and humidity 50% RH. The printing was carried out using a fixed print with the surface temperature of the heating roller of the fixing device set to 110 ° C.

  A 1 cm square image of this print was rubbed three times with a “JK Wiper (registered trademark)” (manufactured by Crecia Co., Ltd.) under a pressure of 10 kPa, and evaluated by the fixing rate of the image. A fixing rate of 80% or more is considered acceptable.

  The image fixing rate is the density of the printed image and the image after rubbing is measured with a reflection densitometer “RD-918” (manufactured by Macbeth), and the reflection density of the solid image after rubbing is printed. This is a numerical value expressed as a percentage obtained by dividing the subsequent solid image by the reflection density.

<Glossy evaluation>
As an image forming apparatus, the developer obtained in each example and each comparative example is put into a commercially available multifunction machine “bishub PRO 1200” (manufactured by Konica Minolta Business Technologies, Inc.), and the surface temperature of the heating roller is set to 125 ° C. In an environment of room temperature and normal humidity (temperature 20 ° C., humidity 50% RH), an image with a toner amount of 4 g / m ² on the transfer paper is formed on high-quality paper (64 g / m ² ) of A4 size and glossy. The degree was measured. The gloss value was evaluated according to the following rank. A glossiness of 35 or less is accepted.

  The glossiness was measured using a gloss meter “Gloss Meter” (manufactured by Murakami Color Research Laboratory Co., Ltd.) at an incident angle of 75 ° with reference to a glass surface with a refractive index of 1.567.

  The evaluation results of each Example and each Comparative Example are shown in Table 1 and Table 2 below.

As is apparent from Tables 1 and 2 above, Examples 1 to 22 in which the toner for developing an electrostatic charge image of the present invention was evaluated can obtain images having excellent low-temperature fixability and excellent low glossiness. It was. On the other hand, Comparative Examples 1 to 11 in which toners having a binder resin that is outside the scope of the present invention were evaluated, none of the low temperature fixability and low glossiness obtained in the examples were obtained. .

Claims (5)

In the electrostatic image developing toner containing at least a binder resin,
The binder resin is
A styrene acrylic modified polyester resin having a styrene acrylic content of 5 to 40% by mass;
A vinyl resin having a content of structural units derived from a (meth) acrylic acid ester monomer of 40 to 90% by mass and a weight average molecular weight of 100,000 to 400,000;
An electrostatic charge image developing toner comprising: The electrostatic image developing toner has a core-shell structure,
The core part of the core-shell structure includes at least the styrene acrylic modified polyester resin and the vinyl resin,
The electrostatic charge image developing toner according to claim 1, wherein the shell portion of the core-shell structure includes at least a polyester resin.   The content of the styrene acrylic modified polyester resin with respect to the total mass of the electrostatic charge image developing toner is 70 to 95% by mass, and the content of the vinyl resin with respect to the total mass of the electrostatic charge developing toner is 5 to 30. The toner for developing an electrostatic charge image according to claim 1, wherein the toner is a mass%. A method for producing an electrostatic charge image developing toner containing at least a binder resin,
Obtaining a dispersion of styrene-acrylic modified polyester resin particles having a styrene-acrylic content of 5 to 40% by mass;
A step of obtaining a dispersion of vinyl resin particles having a content of a structural unit derived from a (meth) acrylic acid ester monomer of 40 to 90% by mass and a weight average molecular weight of 100,000 to 400,000;
Mixing the dispersion of the styrene acrylic modified polyester resin particles and the dispersion of the vinyl resin particles, and aggregating the styrene acrylic modified polyester resin particles and the vinyl resin particles;
A method for producing a toner for developing an electrostatic charge image, comprising:   5. The electrostatic charge image developing toner according to claim 4, further comprising a step of aggregating the polyester resin particles to form a shell after the step of aggregating the styrene acrylic modified polyester resin particles and the vinyl resin particles. Production method.