toner

Abstract

To provide a toner excellent in low-temperature fixability, heat-resistant storage property, developing performance, and image durability.SOLUTION: A magnetic toner including a toner particle containing a magnetic body, a crystalline resin A, and an amorphous resin B. The crystalline resin A has a monomer unit (a), and the amorphous resin B has a monomer unit (b). A content of the crystalline resin A in the toner is 6.2 to 77.0 mass%, the sum of contents of the crystalline resin A and the amorphous resin B in the toner is 30.0 mass%, and a content of the monomer unit (a) in the crystalline resin A is 50.0 to 100.0 mass%. Using SPA[(J / cm3)0.5] for a SP value of the crystalline resin A and using SPB[(J / cm3)0.5] for a SP value of the amorphous resin B, the SPA and the SPB satisfy 0.15≤SPB-SPA≤2.00.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to toners used in electrophotography and electrostatic recording. [Background technology]

[0002] In recent years, energy saving has been considered as a major technical issue in electrophotographic devices, and a significant reduction in the amount of heat required for fixing devices has been considered. In particular, there is an increasing need for toners that can be fixed with less energy, that is, so-called "low-temperature fixing properties."

[0003] As a method for enabling fixing at low temperatures, for example, Patent Document 1 considers a toner containing a plasticizer. The plasticizer has the effect of accelerating the softening speed of the binder resin while maintaining the glass transition temperature (Tg) of the toner, and can improve low-temperature fixing properties. However, since the toner softens through a step of plasticizing the binder resin after the plasticizer melts, there is a limit to the melting speed of the toner, and further improvement in low-temperature fixing properties is desired.

[0004] Therefore, a method of using a crystalline resin as a binder resin has been considered. The molecular chains of a crystalline resin are regularly arranged, so that the resin hardly softens at temperatures lower than the melting point. Furthermore, when the temperature exceeds the melting point, the crystals melt rapidly, and the viscosity drops rapidly. For this reason, the resin is attracting attention as a material that has excellent sharp melting properties and low-temperature fixing properties.

[0005] One of the crystalline resins used for the binder resin of the toner is a side-chain crystalline resin. The side-chain crystalline resin is a vinyl polymer in which a monomer unit having a long-chain alkyl group in the side chain in the molecule is incorporated in the main chain. The side-chain crystalline resin has a long-chain alkyl group in the side chain in the molecule, and the long-chain alkyl groups in the side chain are regularly arranged within the molecule or between the molecules, and crystallize to show crystallinity. The crystallized side-chain crystalline resin has a property that is advantageous for low-temperature fixing because the molecule is easily loosened and has sharp melting properties. On the other hand, since the electrical resistance tends to be low, toners containing a large amount of side-chain crystalline resin have problems such as a low charge retention property and a low developability.

[0006] In addition, in the case of magnetic toner, the magnetic material with low electrical resistance also becomes a source of charge leakage, so the deterioration of developability becomes more significant. As a result, image defects such as "fog" occur easily, where toner with low charge is developed on non-image areas on the photoconductor. As a countermeasure against this, Patent Document 2 proposes a toner that combines a magnetic material whose surface hydrophobicity is controlled with a side chain crystalline resin having a crystalline portion and an amorphous portion. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2013 / 047296 [Patent Document 2] JP 2019-219645 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, although the toner described in Patent Document 2 had a certain effect in improving low-temperature fixing properties and suppressing fogging, it was found that there was room for further improvement in image durability. Because hydroxyl groups exist on the surface of the magnetic material, it tends not to be sufficiently compatible with the highly hydrophobic side-chain crystalline resin. Therefore, when heat is applied to the toner during fixing and the binder resin melts, the magnetic material aggregates with itself. When the magnetic material aggregates on the fixed image, the resin portion and the magnetic material are separated. It is thought that the interface area of ​​the polymer aggregates becomes larger, which may cause cracks to form from there. For the above reasons, further improvements are required in order to realize a toner that is excellent in low-temperature fixing property, heat-resistant storage stability, and developability, as well as in image durability.

[0009] The present disclosure provides a toner that is excellent in low-temperature fixing property, heat-resistant storage stability and developability, and also has excellent image durability. [Means for solving the problem]

[0010] The present disclosure relates to A magnetic toner having toner particles containing a magnetic material, a crystalline resin A, and an amorphous resin B, The crystalline resin A has a monomer unit (a) represented by the following formula (a): The amorphous resin B has a monomer unit (b) represented by the following formula (b): The content of the crystalline resin A in the toner is 6.2 to 77.0% by mass, the sum of the contents of the crystalline resin A and the amorphous resin B in the toner is 30.0% by mass or more; The content of the monomer unit (a) in the crystalline resin A is 50.0 to 100.0 mass %, The SP value of the crystalline resin A is SPA [(J / cm 3 ) 0.5 ], The SP value of the amorphous resin B is SPB [(J / cm 3 ) 0.5 ], The SPA and the SPB are 0.15≦SPB-SPA≦2.00 The present invention relates to a toner which satisfies the above requirements.

[0011] [ka] (In formula (a), R 1 represents a hydrogen atom or a methyl group, L 1 represents a single bond or a divalent linking group, and m represents an integer of 15 to 35. [ka] (In formula (b), R 2 represents a hydrogen atom or a methyl group, L 2 represents a single bond or a divalent linking group, and n represents an integer of 10 to 30. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide a toner which is excellent in low-temperature fixing property, heat-resistant storage stability, and developability, and which also has excellent image durability. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In the present disclosure, the description of a numerical range such as "XX or more and YY or less" or "XX to YY" means a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined. The (meth)acrylic acid ester means an acrylic acid ester and / or a methacrylic acid ester. The term "monomer unit" refers to the reacted form of a monomer substance in a polymer. For example, one section of carbon-carbon bond in the main chain of a polymer formed by polymerization of a polymerizable monomer in a polymer is considered to be one unit. The polymerizable monomer can be represented by the following formula (C). [ka]

[0014] [In formula (C), RA represents a hydrogen atom or an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group); R B represents an optional substituent.] The crystalline resin refers to a resin that shows a clear endothermic peak in a differential scanning calorimeter (DSC) measurement.

[0015] The inventors have discovered that in a magnetic toner containing a magnetic material, a side-chain crystalline resin, and an amorphous resin, the above problem can be solved by introducing a monomer unit having a long-chain alkyl moiety into both the side-chain crystalline resin and the amorphous resin that constitute the toner, and by appropriately controlling the relationship in the SP values ​​of these two types of resin, their content in the toner, and the amount of the long-chain alkyl moiety introduced.

[0016] The present disclosure relates to A magnetic toner having toner particles containing a magnetic material, a crystalline resin A, and an amorphous resin B, The crystalline resin A has a monomer unit (a) represented by the following formula (a): The amorphous resin B has a monomer unit (b) represented by the following formula (b): The content of the crystalline resin A in the toner is 6.2 to 77.0% by mass, the sum of the contents of the crystalline resin A and the amorphous resin B in the toner is 30.0% by mass or more; The content of the monomer unit (a) in the crystalline resin A is 50.0 to 100.0 mass %, The SP value of the crystalline resin A is SPA [(J / cm 3 ) 0.5 ], The SP value of the amorphous resin B is SPB [(J / cm 3 ) 0.5 ], The SPA and the SPB are 0.15≦SPB-SPA≦2.00 The present invention relates to a toner which satisfies the above requirements.

[0017] [ka] (In formula (a), R 1 represents a hydrogen atom or a methyl group, L 1 represents a single bond or a divalent linking group, and m represents an integer of 15 to 35. [ka] (In formula (b), R 2 represents a hydrogen atom or a methyl group, L 2 represents a single bond or a divalent linking group, and n represents an integer of 10 to 30.

[0018] The authors believe that the mechanism by which the effects of the present disclosure are realized is as follows. The crystalline resin A in the present disclosure is a side-chain crystalline resin having a monomer unit with a long-chain alkyl group in the side chain, and has sharp melting properties. Therefore, when the toner particles contain the crystalline resin A, the toner is endowed with sharp melting properties, and low-temperature fixing properties and heat-resistant storage stability are achieved. On the other hand, crystalline resin A is highly hydrophobic because it contains many monomer units with long-chain alkyl groups. However, due to its high hydrophobicity, it tends not to have sufficient affinity with the hydroxyl groups (hereinafter also referred to as hydrophilic parts) present on the surface of the magnetic material, and when the binder resin melts during toner fixing, the magnetic material is prone to agglomeration. Therefore, in the present disclosure, the toner particles contain amorphous resin B. Like crystalline resin A, amorphous resin B is a resin having a monomer unit having a long-chain alkyl group on the side chain, but its SP value is higher than that of crystalline resin A. In other words, the hydrophobicity of amorphous resin B is lower than that of crystalline resin A. As a result, amorphous resin B is more likely to interact with the hydrophilic portion of the magnetic material than crystalline resin A. Furthermore, in the present disclosure, there is a certain relationship between the SP value of amorphous resin B and the SP value of crystalline resin A. In this way, since the toner particles contain amorphous resin B with adjusted hydrophobicity, the hydrophobic interaction between the monomer unit having a long-chain alkyl group of crystalline resin A and the monomer unit having a long-chain alkyl group of amorphous resin B, and the interaction between amorphous resin B and the hydrophilic part of the magnetic material work simultaneously. As a result, the amorphous resin B mediates between the crystalline resin A and the magnetic material, making it possible to suppress aggregation of the magnetic material and improve image durability.

[0019] In addition, in toners that use a combination of a side-chain crystalline resin and an amorphous resin, an interface between the side-chain crystalline resin and the amorphous resin inevitably exists within each toner particle. At this interface, the molecular chains of the side-chain crystalline resin and the molecular chains of the amorphous resin are entangled, and the interface region is crystalline. Therefore, by having long-chain alkyl groups on the side chains of both crystalline resin A and amorphous resin B, it is possible to minimize the decrease in the crystallinity of crystalline resin A at the interface between these resins. As a result, even if the toner particles contain an amorphous resin, the effect of containing crystalline resin A can be achieved. By the above-mentioned mechanism, the toner of the present disclosure is achieved which has excellent low-temperature fixing property, heat-resistant storage stability and developability, as well as excellent image durability.

[0020] The toner of the present disclosure will be described in detail below. The toner particles contain crystalline resin A. By containing crystalline resin A, the toner particles become excellent in low-temperature fixing property, heat-resistant storage stability and developability. The crystalline resin A has a monomer unit (a) represented by the following formula (a): Therefore, the crystalline resin A is a side chain crystalline resin. [ka] (In formula (a), R 1 represents a hydrogen atom or a methyl group, L 1represents a single bond or a divalent linking group, and m represents an integer of 15 to 35.

[0021] Formula (a) indicates that the crystalline resin A has a long-chain alkyl group. By having a long-chain alkyl group as a side chain, the crystalline resin A is more likely to exhibit crystallinity. When m in formula (a) is less than 15, the crystallinity tends to be insufficient, resulting in deterioration of image durability, heat-resistant storage stability and developability. m in formula (a) is preferably 15 to 30, more preferably 17 to 29, and even more preferably 19 to 23.

[0022] L in formula (a) 1 When L is a divalent linking group, the divalent linking group is not particularly limited, and examples thereof include an amide group, an ester group, a urethane group, a urea group, an alkylene group, a phenylene group, a group represented by -O-, and a group represented by -NR- (R represents a hydrogen atom, an alkyl group, a phenyl group, or an aralkyl group). The divalent linking group is preferably an alkylene group, an amide group, or an ester group, and more preferably an ester group. 1 is a divalent linking group, and when the divalent linking group is an ester group, the monomer unit (a) is a monomer unit (a-1) represented by the following formula (a-1).

[0023] Methods for introducing the monomer unit (a) into the crystalline resin A include a method in which monomers such as α-olefins and β-olefins having a long-chain alkyl group with 16 to 36 carbon atoms, (meth)acrylic acid esters having a long-chain alkyl group with 16 to 36 carbon atoms, and N-alkylacrylamides having a long-chain alkyl group with 16 to 36 carbon atoms are subjected to vinyl polymerization.

[0024] Among them, the monomer unit (a) is preferably a monomer unit (a-1) represented by formula (a-1) from the viewpoint of ease of control of the physical properties of the crystalline resin A, such as the SP value and the melting point. [ka] (In formula (a-1), R1 represents a hydrogen atom or a methyl group, and m represents an integer of 15 to 35 (preferably 15 to 30, more preferably 17 to 29, and more preferably 19 to 23).

[0025] As a method for introducing the monomer unit (a-1) represented by formula (a-1), there may be mentioned a method in which a (meth)acrylic acid ester as exemplified below is subjected to vinyl polymerization. For example, monomers of (meth)acrylic acid esters having a linear alkyl group having 16 to 36 carbon atoms [stearyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, heneicosanyl (meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate, ceryl (meth)acrylate, octacosyl (meth)acrylate, myrisyl (meth)acrylate, dotriacontyl (meth)acrylate, etc.] and (meth)acrylic acid esters having a branched alkyl group having 18 to 36 carbon atoms [2-decyltetradecyl (meth)acrylate, etc.]. The monomers forming the monomer unit (a) and the monomer unit (a-1) may be used alone or in combination of two or more kinds.

[0026] The crystalline resin A may have other monomer units in addition to the monomer unit (a). A method for introducing other monomer units includes polymerizing the above-mentioned monomers with other vinyl monomers.

[0027] Other vinyl monomers include the following: (meth)acrylic acid esters such as styrene, α-methylstyrene, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Monomer having a urea group: for example, a monomer obtained by reacting an amine having 3 to 22 carbon atoms [primary amines (such as normal butylamine, t-butylamine, propylamine, and isopropylamine), secondary amines (such as di-normal ethylamine, di-normal propylamine, and di-normal butylamine), aniline, and cycloxylamine] with an isocyanate having 2 to 30 carbon atoms and an ethylenically unsaturated bond by a known method. Monomers having a carboxy group; for example, methacrylic acid, acrylic acid, 2-carboxyethyl (meth)acrylate. Monomers having a hydroxy group; for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, etc. Monomers having an amide group; for example, acrylamide, monomers obtained by reacting an amine having 1 to 30 carbon atoms with a carboxylic acid having 2 to 30 carbon atoms (such as acrylic acid and methacrylic acid) having an ethylenically unsaturated bond by a known method. Monomers having a nitrile group; for example, acrylonitrile, methacrylonitrile, etc. Monomers having a urethane group: for example, monomers having 2 to 22 carbon atoms and an ethylenically unsaturated bond Alcohol (2-hydroxyethyl methacrylate, vinyl alcohol, etc.) and isocyanate having 1 to 30 carbon atoms [monoisocyanate compounds (benzenesulfonyl isocyanate, tosyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, butyl isocyanate, hexyl isocyanate, t-butyl isocyanate, cyclohexyl isocyanate, octyl isocyanate, 2-ethylhexyl isocyanate, dodecyl isocyanate, diisocyanate, adamantyl isocyanate, 2,6-dimethylphenyl isocyanate, 3,5-dimethylphenyl isocyanate, and 2,6-dipropylphenyl isocyanate, etc.), aliphatic diisocyanate compounds (trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2, 4,4-trimethylhexamethylene diisocyanate, etc.), alicyclic diisocyanate compounds (1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated tetramethylxylylene diisocyanate, etc.), and aromatic diisocyanates a monomer obtained by reacting a compound (such as phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenylether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylene diisocyanate) by a known method, and Alcohols with 1 to 26 carbon atoms (methanol, ethanol, propanol, isopropyl alcohol, butanol, t-butyl alcohol, pentanol, heptanol, octanol, 2-ethylhexanol, nonanol, decanol, undecyl alcohol, lauryl alcohol, dodecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetanol, heptadecanol, stearyl alcohol, isostearyl alcohol, elaidyl alcohol, oleyl alcohol, linoleyl alcohol, linolenyl alcohol) and monomers obtained by reacting, by a known method, an isocyanate having 2 to 30 carbon atoms and an ethylenically unsaturated bond [2-isocyanatoethyl (meth)acrylate, 2-(0-[1'-methylpropylideneamino]carboxyamino)ethyl (meth)acrylate, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl (meth)acrylate, 1,1-(bis(meth)acryloyloxymethyl)ethyl isocyanate, etc.]. Vinyl esters: vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl pivalate, vinyl octylate. Of these, it is preferable to use styrene, methacrylic acid, acrylic acid, methyl (meth)acrylate, and t-butyl (meth)acrylate.

[0028] The content of the monomer unit (a) in the crystalline resin A is 50.0 to 100.0% by mass. If the content of the monomer unit (a) is less than 50.0% by mass, the sharp melting property of the crystalline resin A itself is difficult to exhibit, and low-temperature fixability is impaired. The lower limit is more preferably 60.0% by mass or more, even more preferably 65.0% by mass or more, and even more preferably 70.0% by mass or more. From the viewpoint of low-temperature fixability, the upper limit is more preferably 95.0% by mass or less, even more preferably 90.0% by mass or less, and even more preferably 85.0% by mass or less. For example, preferably, 50.0 to 90.0% by mass, 60.0 to 95.0% by mass, 65.0 to 90.0% by mass, 70.0 up to 85.0% by mass. The content of the monomer unit (a) in the crystalline resin A can be adjusted by changing the amount of the monomer that forms the monomer unit (a). When two or more kinds of monomer units (a) are present in the crystalline resin A, the content of the monomer units (a) is the total of those.

[0029] The crystalline resin A preferably has a monomer unit of styrene represented by the following formula (A). The crystalline resin A preferably has a monomer unit of (meth)acrylic acid represented by the following formula (B). Furthermore, the crystalline resin A may have a monomer unit of (meth)acrylonitrile represented by the following formula (C). [ka] In formula (B), R 3 R represents a hydrogen atom or a methyl group. 3 is preferably a methyl group. In formula (C), R 4 R represents a hydrogen atom or a methyl group. 4 is preferably a methyl group.

[0030] The content of styrene monomer units in the crystalline resin A is preferably 1.0 to 50.0 mass%, more preferably 3.0 to 46.0 mass%, further preferably 10.0 to 30.0 mass%, and particularly preferably 15.0 to 27.0 mass%. The content of monomer units of (meth)acrylic acid (preferably methacrylic acid) in the crystalline resin A is preferably 1.0 to 5.0 mass %, more preferably 1.0 to 3.0 mass %, and further preferably 1.5 to 2.5 mass %. The content of monomer units of (meth)acrylonitrile (preferably methacrylonitrile) in the crystalline resin A is preferably 1.0 to 30.0 mass %, more preferably 5.0 to 25.0 mass %, and further preferably 10.0 to 20.0 mass %.

[0031] The content of the crystalline resin A in the toner is 6.2 to 77.0% by mass. When the content of crystalline resin A is less than 6.2% by mass, the toner is not sufficiently given sharp melting properties, and low-temperature fixing property and heat-resistant storage stability are deteriorated.When the content of crystalline resin A is more than 77.0% by mass, the low electrical resistance becomes evident, and developability is deteriorated. From the same viewpoint, the lower limit is preferably 6.8% by mass or more, more preferably 10.0% by mass or more, and even more preferably 15.0% by mass or more, and the upper limit is preferably 70.6% by mass or less, more preferably 60.0% by mass or less, more preferably 50.0% by mass or less, and even more preferably 40.0% by mass or less, for example, preferably 6.8 to 70.6% by mass, 10.0 to 60.0% by mass, 15.0 to 50.0% by mass, or 10.0 to 40.0% by mass.

[0032] The toner particles contain a crystalline resin A and an amorphous resin B. By including Resin B, the amorphous Resin B acts as an intermediary between the crystalline Resin A and the magnetic material, suppressing aggregation of the magnetic material, resulting in a toner with excellent image durability. The amorphous resin B has a monomer unit (b) represented by the following formula (b). [ka] (In formula (b), R 2 represents a hydrogen atom or a methyl group, L 2 represents a single bond or a divalent linking group, and n represents an integer of 10 to 30.

[0033] As mentioned above, since amorphous resin B contains monomer unit (b), it is believed that the decrease in the crystallinity of resin A is minimized while the aggregation of the magnetic material is suppressed, thereby achieving a high level of both low-temperature fixing property and image durability. From the viewpoint of minimizing the decrease in the crystallinity of the crystalline resin A, n is preferably in the range of 10 to 29, more preferably 10 to 19, even more preferably 10 to 15, still more preferably 10 to 14, and particularly preferably 10 to 13. When the resin has the monomer unit (b) represented by the above formula (b) and n is within the above range, the resin exhibits amorphous properties and can be turned into the amorphous resin B. In order to adjust the amorphous properties of the resin, it is also effective to adjust the content ratio of the monomer unit (b) described below.

[0034] L in formula (b) 2 When L is a divalent linking group, the divalent linking group is not particularly limited. 1 The same divalent linking groups as those shown in the above formula (I) can be preferably used. 2 is a divalent linking group, and when the divalent linking group is an ester group, the monomer unit (b) is a monomer unit (b-1) represented by the following formula (b-1).

[0035] Methods for introducing the monomer unit (b) into the amorphous resin B include a method in which monomers such as α-olefins and β-olefins having a long-chain alkyl group with 11 to 31 carbon atoms, (meth)acrylic acid esters having a long-chain alkyl group with 11 to 31 carbon atoms, and N-alkylacrylamides having a long-chain alkyl group with 11 to 31 carbon atoms are subjected to vinyl polymerization.

[0036] Among them, the monomer unit (b) is preferably a monomer unit (b-1) represented by formula (b-1) from the viewpoint of ease of control of the physical properties of the amorphous resin B, such as the SP value and the melting point. [ka] (In formula (b-1), R 2 represents a hydrogen atom or a methyl group, and n represents an integer of 10 to 30 (preferably 10 to 29, more preferably 10 to 19, even more preferably 10 to 15, still more preferably 10 to 14, and particularly preferably 10 to 13).

[0037] The method for introducing the monomer unit (b-1) represented by formula (b-1) may be to use a (meth)acrylic acid ester having a linear alkyl group having 11 to 31 carbon atoms as a monomer. In addition to the above-mentioned monomers usable for the monomer unit (a-1), the following monomers that form the monomer unit (b-1) may be used. For example, octyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate. The monomers forming the monomer unit (b) and the monomer unit (b-1) may be used alone or in combination of two or more kinds.

[0038] In addition, the amorphous resin B may have another monomer unit in addition to the monomer unit (b). As a method for introducing another unit, there is a method for polymerizing a monomer forming the monomer unit (b) with the vinyl monomer usable for the crystalline resin A described above.

[0039] The amorphous resin B preferably has at least one monomer unit Y selected from the group consisting of a monomer unit based on styrene represented by the following formula (D) and a monomer unit based on a (meth)acrylic acid alkyl ester represented by the following formula (E). The amorphous resin B may also have a monomer unit based on (meth)acrylonitrile represented by the following formula (F). [ka] In formula (E), R 5 represents a hydrogen atom or a methyl group, R 6 R represents an alkyl group having 1 to 8 carbon atoms (preferably 1 to 6, more preferably 1 to 4). 5 is preferably a methyl group. In formula (F), R 7 R represents a hydrogen atom or a methyl group. 7 is preferably a methyl group.

[0040] The content of the monomer unit (b) in the amorphous resin B is preferably 2.7 to 47.0% by mass. When the content is within this range, the hydrophobicity of the amorphous resin B tends to be lower than that of the crystalline resin A. As a result, the effect of the amorphous resin B acting as a mediator between the crystalline resin A and the magnetic material becomes greater, which can further suppress the aggregation of the magnetic material and improve the image durability. The lower limit of the content of the monomer unit (b) is preferably 3.0% by mass or more, more preferably 5.0% by mass or more, even more preferably 10.0% by mass or more, particularly preferably 15.0% by mass or more, and even more preferably 20.0% by mass or more. The upper limit is preferably 43.0% by mass or less, more preferably 40.0% by mass or less, even more preferably 35.0% by mass or less, and particularly preferably 30.0% by mass or less. For example, preferred are 3.0 to 43.0% by mass, 5.0 to 40.0% by mass, 10.0 to 35.0% by mass, 15.0 to 30.0% by mass, and 20.0 to 30.0% by mass. When the proportion of the monomer unit (b) is within the above range, the resin tends to exhibit amorphous properties, and is easily converted into amorphous resin B. In addition, low-temperature fixability, heat-resistant storage stability, developability, and image durability are all achieved at a high level. The content of the monomer unit (b) in the amorphous resin B can be adjusted by changing the amount of the monomer that forms the monomer unit (b).

[0041] In the amorphous resin B, the content of at least one monomer unit Y selected from the group consisting of a monomer unit based on styrene represented by the above formula (D) and a monomer unit based on a (meth)acrylic acid alkyl ester represented by the above formula (E) is preferably 50.0 to 97.0 mass%, more preferably 60.0 to 90.0 mass%, even more preferably 65.0 to 85.0 mass%, and even more preferably 70.0 to 80.0 mass%. The content of monomer units of (meth)acrylonitrile (preferably methacrylonitrile) in the amorphous resin B is preferably 1.0 to 30.0 mass %, more preferably 5.0 to 25.0 mass %, and further preferably 10.0 to 20.0 mass %.

[0042] The content of the amorphous resin B in the toner is preferably 2.7 to 63.0% by mass, more preferably 2.9 to 58.8% by mass, even more preferably 11.0 to 55.0% by mass, even more preferably 20.0 to 55.0% by mass, and particularly preferably 25.0 to 45.0% by mass. By having the content of the amorphous resin B in the above range, low-temperature fixing property, image durability, and developability are all achieved at a high level.

[0043] The sum of the contents of crystalline resin A and amorphous resin B in the toner is 30.0% by mass or more. The sum of the contents of crystalline resin A and amorphous resin B in the toner is preferably 30.0 to 95.0% by mass, more preferably 34.1 to 73.5% by mass, and even more preferably 45.0 to 62.0% by mass. By setting the sum of the contents of the crystalline resin A and the amorphous resin B within the above range, it is possible to achieve a high level of low-temperature fixability, heat-resistant storage stability, developability, and image durability.

[0044] The glass transition temperature Tg of the amorphous resin B is preferably 30.0 to 90.0°C. The fact that the amorphous resin B has a Tg indicates that the amorphous resin B is an amorphous resin that is in a glassy state at room temperature, and this improves image durability. Furthermore, it is preferable that the Tg is in the above range from the viewpoints of low-temperature fixability and heat-resistant storage stability. The glass transition temperature Tg of the amorphous resin B can be controlled by changing the composition of the amorphous resin B.

[0045] The SP value of crystalline resin A is SPA [(J / cm 3 ) 0.5 ], and the SP value of amorphous resin B is SPB[(J / cm 3 ) 0.5 ], SPA and SPB satisfy 0.15≦SPB−SPA≦2.00. The SP value, also known as the solubility parameter, is a number used as an index of solubility and affinity, showing how much a substance dissolves in another substance. Materials with similar SP values ​​have high solubility and affinity, while materials with different SP values ​​have low solubility and affinity. SPB-SPA represents the difference in the SP values ​​between crystalline resin A and amorphous resin B, i.e., the degree of affinity between crystalline resin A and amorphous resin B. If SPB-SPA is smaller than 0.15, the compatibility between the two resins is too good, causing them to become miscible with each other, lowering the crystallinity of crystalline resin A and preventing the heat-resistant storage stability and developability from being fully demonstrated. If SPB-SPA is greater than 2.00, the two do not mix well, and crystalline resin A, which is a side-chain crystalline resin, tends to exist as large domains, which reduces the dispersion of the magnetic material, and therefore low-temperature fixability and image durability are not sufficiently improved. SPB-SPA is preferably 0.20≦SPB-SPA≦1.60, more preferably 0.60≦SPB-SPA≦1.30, and further preferably 0.80≦SPB-SPA≦1.20. SPA and SPB can be controlled by changing the composition of the crystalline resin A and the amorphous resin B.

[0046] The SPA of the crystalline resin is not particularly limited as long as the SPA and SPB satisfy the above relationship, but is preferably 17.00 to 20.00, more preferably 17.50 to 19.50, further preferably 18.00 to 19.00, and particularly preferably 18.20 to 18.80.

[0047] The toner may contain other resin components for various purposes in addition to the crystalline resin A and the amorphous resin B. Examples of resins that can be used include vinyl resins, polyesters, polyurethanes, and epoxy resins that do not fall under the category of the crystalline resin A and the amorphous resin B, and polyesters are preferred. For example, the crystalline resin A, the amorphous resin B, and other resins may be binder resins. Examples of the polymerizable monomers forming the vinyl resins other than the crystalline resin A and the amorphous resin B include those other than the polymerizable monomers forming the monomer unit (a) or the monomer unit (b) among those mentioned above. Two or more kinds may be used in combination as necessary.

[0048] The polyester can be obtained by a polycondensation reaction between a divalent or higher polyvalent carboxylic acid and a polyhydric alcohol. Examples of polycarboxylic acids include the following compounds: Dibasic acids such as succinic acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, malonic acid, and dodecenylsuccinic acid, and their anhydrides or lower alkyl esters, and aliphatic unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, and citraconic acid. 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, and their anhydrides or lower alkyl esters. Preferred are terephthalic acid, isophthalic acid, and trimellitic anhydride. These may be used alone or in combination of two or more.

[0049] Examples of the polyhydric alcohol include the following compounds: Alkylene glycols (ethylene glycol, 1,2-propylene glycol and 1,3-propylene glycol); alkylene ether glycols (polyethylene glycol and polypropylene glycol); alicyclic diol (1,4-cyclohexanedimethanol); bisphenols (bisphenol A); alkylene oxide (ethylene oxide and propylene oxide) adducts of alicyclic diols; alkylene oxide (ethylene oxide and propylene oxide) adducts of bisphenols such as bisphenol A-propylene oxide 2-mol adduct. The alkyl moieties of the alkylene glycol and alkylene ether glycol may be linear or branched. Preferred are alkylene oxides of bisphenols, more preferably bisphenol A-propylene oxide 2-mol adduct. Branched alkylene glycols can also be preferably used, such as glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These can be used alone or in combination of two or more. For the purpose of adjusting the acid value or hydroxyl value, monovalent acids such as acetic acid and benzoic acid, and monovalent alcohols such as cyclohexanol and benzyl alcohol can also be used as necessary. The method for producing the polyester is not particularly limited, but examples thereof include an ester exchange method and a direct polycondensation method.

[0050] Polyurethane is obtained by reacting a diol component with a diisocyanate component. Examples of the diisocyanate component include the following: aromatic diisocyanates having 6 to 20 carbon atoms (excluding carbons in NCO groups, the same applies below), aliphatic diisocyanates having 2 to 18 carbon atoms, alicyclic diisocyanates having 4 to 15 carbon atoms, modified products of these diisocyanates (modified products containing urethane groups, carbodiimide groups, allophanate groups, urea groups, biuret groups, uretdione groups, uretoimine groups, isocyanurate groups, or oxazolidone groups; hereinafter also referred to as "modified diisocyanates"), and mixtures of two or more of these. Aromatic diisocyanates include m- and / or p-xylylene diisocyanate (XDI) and α,α,α',α'-tetramethylxylylene diisocyanate. Additionally, examples of the aliphatic diisocyanate include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), and dodecamethylene diisocyanate. Examples of alicyclic diisocyanates include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate, cyclohexylene diisocyanate, and methylcyclohexylene diisocyanate.

[0051] Among these, aromatic diisocyanates having 6 to 15 carbon atoms, aliphatic diisocyanates having 4 to 12 carbon atoms, and alicyclic diisocyanates having 4 to 15 carbon atoms are preferred, and XDI, IPDI, and HDI are particularly preferred. In addition to the diisocyanate component, a tri- or higher isocyanate compound can also be used. As the diol component that can be used in the polyurethane, the same dihydric alcohols that can be used in the polyester described above can be used.

[0052] The weight average molecular weight (Mw) of the tetrahydrofuran (THF) soluble matter of the toner measured by gel permeation chromatography (GPC) is preferably 10,000 to 200,000. The lower limit is more preferably 30,000 or more, even more preferably 50,000 or more, even more preferably 80,000 or more, and particularly preferably 90,000 or more. The upper limit is more preferably 180,000 or less, even more preferably 150,000 or less, even more preferably 130,000 or less, and particularly preferably 120,000 or less. For example, 30,000 to Examples of the Mw include 180000, 50000 to 150000, 80000 to 130000, and 90000 to 120000. When the Mw is within the above range, the toner is likely to have low temperature fixability.

[0053] The toner may contain a release agent. The release agent is preferably at least one selected from the group consisting of a hydrocarbon wax and an ester wax. By using a hydrocarbon wax and / or an ester wax, effective releasability can be easily ensured.

[0054] The hydrocarbon wax is not particularly limited, but examples thereof include the following: Aliphatic hydrocarbon waxes: low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight olefin copolymer, Fischer-Tropsch wax, or waxes obtained by oxidizing or adding an acid to these.

[0055] The ester wax may be any wax having at least one ester bond in one molecule, and may be either a natural ester wax or a synthetic ester wax. The ester wax is not particularly limited, but examples thereof include the following. Esters of monohydric alcohols and monocarboxylic acids, such as behenyl behenate, stearyl stearate, and palmityl palmitate; Esters of divalent carboxylic acids and monoalcohols, such as dibehenyl sebacate; Esters of dihydric alcohols and monocarboxylic acids, such as ethylene glycol distearate and hexanediol dibehenate; Esters of trihydric alcohols and monocarboxylic acids, such as glycerol tribehenate; Esters of tetrahydric alcohols and monocarboxylic acids, such as pentaerythritol tetrastearate and pentaerythritol tetrapalmitate; Esters of hexahydric alcohols and monocarboxylic acids, such as dipentaerythritol hexastearate, dipentaerythritol hexapalmitate, and dipentaerythritol hexabehenate; Esters of polyfunctional alcohols and monocarboxylic acids, such as polyglycerin behenate; natural ester waxes, such as carnauba wax and rice wax;

[0056] Among these, esters of hexahydric alcohols and monocarboxylic acids such as dipentaerythritol hexastearate, dipentaerythritol hexapalmitate, and dipentaerythritol hexabehenate are preferred.

[0057] The release agent may be a hydrocarbon wax or an ester wax, or may be a combination of a hydrocarbon wax and an ester wax, or may be a mixture of two or more of each, but it is preferable to use a hydrocarbon wax alone or two or more of each. It is more preferable that the release agent is a hydrocarbon wax. In the toner, the content of the release agent in the toner particles is preferably 1.0% by mass or more and 30.0% by mass or less, more preferably 2.0% by mass or more and 25.0% by mass or less. When the content of the release agent in the toner particles is in the above range, the releasability during fixing is easily ensured. The melting point of the release agent is preferably 60° C. or more and 120° C. or less. When the melting point of the release agent is in the above range, the release agent melts during fixing and easily seeps out onto the toner particle surface, and the release property is easily exhibited. The melting point is more preferably 70° C. or more and 100° C. or less.

[0058] The toner particles contain a magnetic material. Examples of magnetic materials used in magnetic toner include: Magnetic iron oxides, such as magnetite, maghemite, ferrite, and further including other metal oxides; Metals such as Fe, Co, Ni, or these metals combined with Al, Co, Cu, Pb, Mg, Examples include metals such as Ni, Sn, Zn, Sb, Be, Bi, Cd, Ca, Mn, Se, Ti, W, and V, alloys with oxides of these metals, and mixtures of these. Among these magnetic materials, magnetite is preferred.

[0059] The shape of the magnetic material may be polyhedral, octahedral, hexahedral, spherical, needle-like, flaky, etc. Among these shapes, shapes with less anisotropy such as polyhedral, octahedral, hexahedral, and spherical shapes are preferred in terms of increasing image density.

[0060] The volume average particle diameter of the magnetic material is preferably 0.10 to 0.40 μm. If the volume average particle diameter is 0.10 μm or more, the magnetic material is less likely to aggregate, and the uniform dispersion of the magnetic material in the toner particles is improved. If the volume average particle diameter is 0.40 μm or less, the coloring power of the toner is improved.

[0061] The volume average particle size of the magnetic material can be measured using a transmission electron microscope. Specifically, the toner is thoroughly dispersed in the epoxy resin, and then the mixture is cured in an atmosphere at 40°C for two days to obtain a cured product. The obtained cured product is cut into a thin-section sample using a microtome, and the particle sizes of 100 magnetic particles in the field of view are measured using a transmission electron microscope (TEM) at a magnification of 10,000 to 40,000 times. The projected area of ​​the magnetic particles is measured, the radius of a circle having an area equal to the projected area is calculated, and the volume of a sphere having that radius is calculated to roughly estimate the volume of the magnetic particles. From these results, the volume average particle size is calculated. It is also possible to measure the volume average particle size of the magnetic particles using an image analyzer.

[0062] The content of the magnetic material in the toner is preferably 5.0 to 50.0% by mass, more preferably 7.0 to 45.0% by mass, and even more preferably 15.0 to 40.0% by mass. When the magnetic material is in the above range, it becomes easier to achieve high levels of low-temperature fixability, image durability, and developability.

[0063] The magnetic material used in the toner can be produced, for example, by the following method. An aqueous solution containing ferrous hydroxide is prepared by adding an equivalent or greater amount of alkali, such as sodium hydroxide, to an aqueous solution of ferrous salt. While maintaining the pH of the prepared aqueous solution at 7 or higher, air is blown in and the aqueous solution is heated to 70°C or higher to carry out an oxidation reaction of the ferrous hydroxide, thereby first producing seed crystals that will become the core of the magnetic material. Next, an aqueous solution containing 1 equivalent of ferrous sulfate based on the amount of alkali added previously is added to the slurry liquid containing the seed crystals. The pH of the liquid is maintained at 5-10, and the reaction of ferrous hydroxide is allowed to proceed while blowing in air, and magnetic iron oxide particles are grown around the seed crystals as cores. At this time, the shape and magnetic properties of the magnetic material can be controlled by adjusting the pH, reaction temperature, and stirring conditions. As the oxidation reaction progresses, the pH of the liquid shifts to the acidic side, but it is preferable that the pH of the liquid not be lowered below 5. The magnetic iron oxide particles thus obtained are filtered, washed, and dried to obtain a magnetic material.

[0064] In addition, when toner particles are produced by a polymerization method, it is preferable to subject the surface of the magnetic material to a hydrophobic treatment. The method of the hydrophobic treatment is not particularly limited, but for example, a coupling agent treatment can be used. When the hydrophobic treatment is performed in a dry manner, the surface of the magnetic material can be hydrophobized by subjecting the surface of the magnetic material that has been washed, filtered, and dried to a coupling agent treatment. When the hydrophobization treatment is carried out by a wet method, the dried material after the oxidation reaction is completed is then redispersed, or the iron oxide obtained after the oxidation reaction is completed, washed, filtered and then redispersed in another aqueous medium without drying, and then a coupling agent treatment can be carried out. When redispersing, specifically, a silane coupling agent is added to the redispersed solution of iron oxide while stirring the redispersed solution. The coupling agent treatment can be carried out by adding a coupling agent and then increasing the temperature after hydrolysis, or by adjusting the pH of the redispersion liquid to an alkaline range after hydrolysis.

[0065] Among these, from the viewpoint of uniformly hydrophobizing the surface of the magnetic material, it is preferable to filter and wash the magnetic material after the oxidation reaction is completed, and then to perform the hydrophobizing treatment as it is without drying, forming the magnetic material into a slurry. The following method can be exemplified for wet hydrophobizing the magnetic material. First, the magnetic material is dispersed in an aqueous medium so as to become primary particles, and stirred with a stirring blade or the like so as not to cause sedimentation or aggregation. Next, an appropriate amount of coupling agent is added to the dispersion, and the coupling agent is treated while hydrolyzing the coupling agent. At this time, it is preferable to perform the coupling agent treatment while dispersing the magnetic material so as not to cause aggregation, using a device such as a pin mill or line mill while stirring. An aqueous medium is a medium whose main component is water. Examples include water itself, a medium in which a small amount of a surfactant has been added to water, a medium in which a pH adjuster has been added to water, and a medium in which an organic solvent has been added to water.

[0066] The surfactant is preferably a nonionic surfactant such as polyvinyl alcohol, etc. The surfactant is preferably added to the aqueous medium so as to have a concentration of 0.1 to 5.0% by mass. The pH adjuster may, for example, be an inorganic acid such as hydrochloric acid. The organic solvent may, for example, be an alcohol.

[0067] Examples of coupling agents that can be used in the hydrophobization treatment of the surface of the magnetic material include silane coupling agents, titanium coupling agents, etc. Among these, silane coupling agents are preferred, and silane coupling agents represented by the following formula (G) are more preferred. R m -Si-Y n (G) In formula (G), R represents an alkoxy group (preferably an alkoxy group having 1 to 3 carbon atoms), and m represents an integer of 1 to 3. Y represents an alkyl group (preferably an alkyl group having 2 to 20 carbon atoms), a phenyl group, a vinyl group, an epoxy group, an acrylic group, or a methacryl group. m and n each independently represent an integer of 1 to 3, provided that m and n satisfy m+n=4.

[0068] Examples of the silane coupling agent represented by the above formula (E) include: Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyl Trimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, trimethylmethoxysilane, n-hexyltrimethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, hydroxypropyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane etc.

[0069] Among these, it is preferable to use an alkyltrialkoxysilane coupling agent represented by the following formula (H) in terms of imparting high hydrophobicity to the magnetic material. C p H 2p+1 -Si-(OC q H 2q+1 )3(H) In the above formula (H), p represents an integer of 2 to 20, and q represents an integer of 1 to 3. When p in the above formula (H) is 2 or more, the magnetic material can be sufficiently imparted with hydrophobicity. When p is 20 or less, the magnetic material can be prevented from coalescing with itself. When q is 3 or less, the reactivity of the silane coupling agent is good, and the magnetic material can be sufficiently imparted with hydrophobicity. In the above formula (H), p is preferably an integer of 3 to 15, and q is preferably 1 or 2.

[0070] When using a hydrophobic treatment agent such as a silane coupling agent, one type may be used alone or two or more types may be used in combination. When using two or more types in combination, the treatment may be performed with each hydrophobic treatment agent individually or simultaneously. The total amount of the coupling agent used is preferably 0.9 to 3.0 parts by mass per 100 parts by mass of the magnetic material, and the amount of the coupling agent is preferably adjusted depending on the surface area of ​​the magnetic material, the reactivity of the coupling agent, and the like.

[0071] The toner may contain a colorant. Examples of the colorant include known organic pigments, organic dyes, inorganic pigments, and carbon black as a black colorant. In addition, colorants that have been used in conventional toners may also be used. Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specifically, CI Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 155, 168, and 180 are preferably used.

[0072] Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, CI Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254 are preferably used. Examples of cyan colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds. Specifically, CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66 are preferably used.

[0073] The colorant is selected in consideration of hue angle, chroma, brightness, light resistance, transparency on an OHP sheet, and dispersibility in the toner. The content of the colorant is preferably 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin.

[0074] If necessary, a charge control agent may be contained in the toner particles. Alternatively, the charge control agent may be added externally to the toner particles. By blending the charge control agent, it becomes possible to stabilize the charge characteristics and control the amount of triboelectric charge optimally according to the development system. Any known charge control agent can be used as the charge control agent, and a charge control agent that can charge quickly and stably maintain a constant charge amount is particularly preferred.

[0075] As the charge control agent, the following can be mentioned as the agent that controls the toner to be negatively charged. Organic metal compounds and chelate compounds are effective, and monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids, and and dicarboxylic acid-based metal compounds. The substances that control the toner to have a positive charge include the following: nigrosine, quaternary ammonium salts, metal salts of higher fatty acids, diorgano tin borates, guanidine compounds, and imidazole compounds. The content of the charge control agent is preferably 0.01 parts by mass or more and 20.0 parts by mass or less, and more preferably 0.5 parts by mass or more and 10.0 parts by mass or less, relative to 100.0 parts by mass of the toner particles.

[0076] The toner particles may be used as they are as a toner, or may be used as a toner by mixing with an external additive, if necessary, and attaching the additive to the surface of the toner particles. The external additive may be an inorganic fine particle selected from the group consisting of silica fine particles, alumina fine particles, and titania fine particles, or a composite oxide thereof, etc. Examples of the composite oxide include silica aluminum fine particles and strontium titanate fine particles. The content of the external additive is preferably 0.01 parts by mass or more and 8.0 parts by mass or less, and more preferably 0.1 parts by mass or more and 4.0 parts by mass or less, based on 100 parts by mass of the toner particles.

[0077] The toner particles may be produced by any known method, such as a suspension polymerization method, an emulsion aggregation method, a dissolution suspension method, or a pulverization method, so long as it falls within the scope of the present invention, but it is preferable to produce the toner particles by a suspension polymerization method.

[0078] The suspension polymerization method will now be described in detail. For example, the polymerizable monomers that produce the previously synthesized crystalline resin A and amorphous resin B, as well as other materials such as a magnetic material, a colorant, a release agent, and a charge control agent, as necessary, are mixed and uniformly dissolved or dispersed to prepare a polymerizable monomer composition. Thereafter, the polymerizable monomer composition is dispersed in an aqueous medium using a stirrer or the like to prepare suspended particles of the polymerizable monomer composition, and then the polymerizable monomer contained in the particles is polymerized using an initiator or the like to obtain toner particles. After the polymerization is completed, the toner particles are filtered, washed and dried by known methods, and external additives are added as necessary to obtain the toner.

[0079] As the polymerization initiator, a known polymerization initiator can be used. Examples of the polymerization initiator include azo or diazo polymerization initiators such as 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile; and peroxide polymerization initiators such as benzoyl peroxide, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide. Furthermore, known chain transfer agents and polymerization inhibitors may be used.

[0080] The aqueous medium may contain an inorganic or organic dispersion stabilizer. As the dispersion stabilizer, a known dispersion stabilizer can be used. Examples of inorganic dispersion stabilizers include hydroxyapatite, tricalcium phosphate, dicalcium phosphate, magnesium phosphate, aluminum phosphate, and phosphate. Phosphates such as zinc; carbonates such as calcium carbonate and magnesium carbonate; metal hydroxides such as calcium hydroxide, magnesium hydroxide and aluminium hydroxide; sulfates such as calcium sulphate and barium sulphate; calcium metasilicate; bentonite; silica; aluminium Mina is one example.

[0081] On the other hand, examples of organic dispersion stabilizers include polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and its salts, and starch.

[0082] When an inorganic compound is used as the dispersion stabilizer, a commercially available product may be used as it is, but in order to obtain finer particles, the inorganic compound may be formed in an aqueous medium and then used. For example, in the case of calcium phosphates such as hydroxyapatite or tricalcium phosphate, an aqueous solution of the phosphate may be mixed with an aqueous solution of the calcium salt under high agitation.

[0083] The aqueous medium may contain a surfactant. As the surfactant, a known surfactant can be used. For example, anionic surfactants such as sodium dodecylbenzene sulfate and sodium oleate, cationic surfactants, amphoteric surfactants, and nonionic surfactants can be mentioned.

[0084] The method for producing the toner by the pulverization method is not particularly limited, but is preferably A process of melting and kneading raw materials containing crystalline resin A, amorphous resin B, and, as necessary, magnetic material, colorant, release agent, etc.; and The resulting molten and kneaded product is pulverized to obtain toner particles. For melt-kneading and pulverization, known devices may be used.

[0085] The emulsion aggregation method is not particularly limited, but is preferably A dispersion process for preparing a fine particle dispersion liquid composed of each raw material of the toner particles (crystalline resin A, amorphous resin B, and, if necessary, a magnetic material, a colorant, a release agent, etc.); an aggregation step in which fine particles made of each raw material of the toner particles are aggregated and the particle size is controlled until the particle size of the toner particles is reached; The toner particles are then subjected to a fusing step in which the resin contained in the resulting aggregate particles is fused to obtain toner particles. If necessary, the toner particles may be obtained through a subsequent cooling step, a metal removal step in which the obtained toner particles are filtered and excess polyvalent metal ions are removed, a filtration / washing step in which the toner particles are washed with ion-exchanged water or the like, and a step in which moisture is removed from the washed toner particles and they are dried.

[0086] The calculation and measurement methods for various physical properties are described below. <Method of measuring the molecular weight of toner> The molecular weight (weight average molecular weight Mw) of the THF-soluble portion of the toner is measured by gel permeation chromatography (GPC) as follows. First, the toner is dissolved in tetrahydrofuran (THF) at room temperature for 24 hours. The resulting solution is then filtered through a solvent-resistant membrane filter "Myshoridisc" (manufactured by Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of components soluble in THF is 0.8 mass %. This sample solution is used to perform measurements under the following conditions. Equipment: HLC8120 GPC (detector: RI) (Tosoh Corporation) Column: 7 columns of Shodex KF-801, 802, 803, 804, 805, 806, 807 (Showa Denko Co., Ltd.) Eluent: Tetrahydrofuran (THF) ·Flow rate: 1.0ml / min Oven temperature: 40.0℃ Sample injection volume: 0.10ml When calculating the molecular weight of the sample, a standard polystyrene resin (for example, TSK A molecular weight calibration curve prepared using standard polystyrene (F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500, manufactured by Tosoh Corporation) is used.

[0087] <Method of separating crystalline resin A and amorphous resin B from toner> The crystalline resin A and the amorphous resin B can be separated from the toner by a known method, and an example will be described below. Gradient LC is used as a method for separating resin components from toner. This analysis allows separation according to the polarity of the resin in the binder resin, regardless of molecular weight.

[0088] First, the toner is dissolved in chloroform. The sample is adjusted to a sample concentration of 0.1% by mass in chloroform, and the solution is filtered through a 0.45 μm PTFE filter before being used for measurement. The gradient polymer LC measurement conditions are as follows: Equipment: UlTIMATE3000 (Thermo Fisher Scientific) Mobile phase: A Chloroform (HPLC), B Acetonitrile (HPLC) Gradient: 2 min (A / B = 0 / 100) → 25 min (A / B = 100 / 0) (Note that the gradient of the change in mobile phase was made linear.) Flow rate: 1.0mL / min Injection: 0.1% by mass x 20μL Column: Tosoh TSKgel ODS (4.6mmφx150mm x 5μm) Column temperature: 40℃ Detector: Corona Charged Aerosol Detector (Corona-CAD) (Thermo Fisher Scientific)

[0089] The time-intensity graph obtained by the measurement shows that the resin components can be separated into two peaks according to their polarity. After that, the above measurement is carried out again, and by taking out the fractions at the time when the respective peaks reach their valleys, it is possible to separate the two types of resin. The separated resins are subjected to DSC measurement and 1 H-NMR measurement is performed, and the resins are assigned to crystalline resin A and amorphous resin B based on the results. In addition, when other resins are contained in addition to crystalline resin A and amorphous resin B, the above-mentioned separation by gradient LC, DSC measurement, and 1 They can be separated by H-NMR measurement.

[0090] If the toner contains a release agent, it is necessary to separate the release agent from the toner. The release agent is separated by recycling HPLC to separate components with a molecular weight of 2000 or less as the release agent. The measurement method is as follows. First, a chloroform solution of the toner is prepared by the method described above. The resulting solution is then filtered through a solvent-resistant membrane filter "Myshoridisc" (manufactured by Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of components soluble in chloroform is 1.0 mass %. This sample solution is used to perform measurements under the following conditions. ·Equipment: LC-Sakura NEXT (manufactured by Nippon Analytical Industry Co., Ltd.) Column: JAIGEL 2H, 4H (Japan Analytical Industry Co., Ltd.) Eluent: Chloroform ·Flow rate: 10.0ml / min Oven temperature: 40.0℃ Sample injection volume: 1.0ml In calculating the molecular weight of the sample, standard polystyrene resins (e.g., TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-8 A molecular weight calibration curve prepared using "A-5000, A-2500, A-1000, A-500" (manufactured by Tosoh Corporation) is used. From the molecular weight curve thus obtained, components having a molecular weight of 2000 or less are repeatedly separated and the release agent is removed from the toner.

[0091] <Method for measuring the content of various monomer units in resin> The content ratio of various monomer units in a resin is measured as follows: 1 The measurement is performed by H-NMR under the following conditions. The measurement samples can be the crystalline resin A and the amorphous resin B separated by the above-mentioned method. Measuring device: FT NMR device JNM-EX400 (manufactured by JEOL Ltd.) Measurement frequency: 400MHz Pulse condition: 5.0μs Frequency range: 10500Hz Number of times: 64 Measurement temperature: 30℃

[0092] Sample: 50 mg of the measurement sample is placed in a sample tube with an inner diameter of 5 mm, deuterated chloroform (CDCl3) is added as a solvent, and this is dissolved in a thermostatic bath at 40°C to prepare the sample. 1 The H-NMR chart is analyzed to identify the structure of each monomer unit. This identification makes it possible to confirm that crystalline resin A and amorphous resin B contain each monomer unit. Here, as an example, the measurement of the content of the monomer unit (a) in the crystalline resin A will be described. 1 In the H-NMR chart, a peak that is independent of the peaks that are attributable to the components of the monomer unit (a) is selected from the peaks that are attributable to the components of the other monomer units, and the integral value S1 of this peak is calculated. The integral values ​​of the other monomer units contained in the crystalline resin A are also calculated in the same manner.

[0093] When the monomer unit constituting the crystalline resin A is the monomer unit (a) and one other monomer unit, the content ratio of the monomer unit (a) is determined as follows using the above integral value S1 and the integral value S2 of the peak of the other monomer unit. Here, n1 and n2 are the number of hydrogens in the component to which the peak focused on each site belongs. Content ratio (mol%) of monomer unit (a) = {(S1 / n1) / ((S1 / n1)+(S2 / n2))}×100 Even when there are two or more other monomer units, the content ratio of the monomer unit (a) can be calculated in the same manner (using S3···Sx and n3···nx).

[0094] When a polymerizable monomer containing no hydrogen atom in a component other than the vinyl group is used, 13 using C-NMR, the measurement nucleus is 13 C, and the measurement is performed in single pulse mode, 1 and calculated in the same manner by H-NMR. Multiply the ratio (mol%) of each monomer unit calculated by the above method by the molecular weight of each monomer unit to convert the content ratio of each monomer unit to mass%. The same method is used for measurement in the amorphous resin B.

[0095] <Measurement of the content ratios of the crystalline resin A and the amorphous resin B in the toner> In the method for separating the crystalline resin A and the amorphous resin B from the toner described above, based on the toner mass before dissolution in chloroform, the mass of the separated crystalline resin A, and the mass of the amorphous resin B, the content ratios of the crystalline resin A and the amorphous resin B in the toner are calculated.

[0096] <Calculation methods for SPA and SPB> SPA and SPB are determined as follows according to the calculation method proposed by Fedors. For each atom or group in the molecular structure, the evaporation energy (Δei) (cal / mol) and molar volume (Δvi) (cm) are calculated from the table in "Polym. Eng. Sci., 14(2), 147-154 (1974)". 3 / mol), (4.184×ΣΔei / ΣΔvi) 0.5 SP value (J / cm 3 ) 0.5 Let us assume that. Specifically, the evaporation energy (Δei) and molar volume (Δvi) of the monomer unit corresponding to the monomer constituting the crystalline resin A or the amorphous resin B are determined for each monomer unit, and the product of each monomer unit and the molar ratio (j) of each monomer unit in resin A is calculated. The sum of the evaporation energies of each monomer unit is divided by the sum of the molar volumes to obtain the formula (5) below. SPA or SPB = {4.184 × (Σj × ΣΔei) / (Σj × ΣΔvi)} 0.5 (5)

[0097] <Measurement of glass transition temperature Tg of amorphous resin B> The glass transition temperature (Tg) is measured using a differential scanning calorimeter "Q1000" (manufactured by TA Instruments). The melting points of indium and zinc are used for temperature correction of the detector of the device, and the heat of fusion of indium is used for heat correction. Specifically, 1 mg of amorphous resin B is weighed out and placed in an aluminum pan, and an empty aluminum pan is used as a reference. Using the modulation measurement mode, measurements are performed in the range of 0°C to 120°C with a temperature rise rate of 1°C / min and temperature modulation conditions of ±0.6°C / 60 seconds. Since the specific heat change is obtained during the temperature rise process, the intersection point between the line at the midpoint of the baseline before and after the specific heat change and the differential heat curve is taken as the glass transition temperature (Tg). If the temperature range where the specific heat change occurs overlaps with the endothermic peak of a crystalline resin or wax, the specific heat change occurs before and after the endothermic peak. In such a case, the glass transition temperature (Tg) is the intersection point of a straight line connecting the endothermic peak's endothermic start temperature (onset temperature) and endothermic end temperature (offset temperature) with a line that is the midpoint between the baselines before and after the specific heat change occurs.

[0098] <Measurement of the content of magnetic material in toner> The content of the magnetic material in the toner can be measured using a thermal analyzer TGAQ5000IR manufactured by PerkinElmer, Inc. The measurement method is to heat the toner from room temperature to 900°C at a heating rate of 25°C / min in a nitrogen atmosphere, and the weight loss from 100°C to 750°C is the weight of the components excluding the magnetic material from the toner, and the remaining weight is the amount of magnetic material. EXAMPLES

[0099] The present disclosure will be specifically described below with reference to examples, but these are not intended to limit the present disclosure in any way. In the following formulations, parts are by weight unless otherwise specified.

[0100] (Preparation Example of Crystalline Resin A1) The following materials were placed in a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube under a nitrogen atmosphere. Toluene 100.0 parts Monomer composition 100.0 parts (The monomer composition is a mixture of the following monomers in the ratio shown below.) (Behenyl acrylate (monomer (a)) 80.0 parts) (18.0 parts styrene) (Methacrylic acid 2.0 parts) Polymerization initiator: 0.5 parts t-butyl peroxypivalate (NOF Corp.: Perbutyl PV) The inside of the reaction vessel was heated to 70°C while stirring at 200 rpm, and polymerization reaction was carried out for 12 hours, to obtain a solution in which the polymer of the monomer composition was dissolved in toluene. Then, the temperature of the solution was lowered to 25°C, and the solution was poured into 1000.0 parts of methanol while stirring, to precipitate the methanol insoluble matter. The obtained methanol insoluble matter was filtered, washed with methanol, and then vacuum dried at 40°C for 24 hours to obtain crystalline resin A1.

[0101] (Preparation Examples of Crystalline Resins A2 to A11) Crystalline Resins A2 to A11 were prepared in the same manner as in the preparation of Crystalline Resin A1, except that the amount of the monomer composition added was changed to that shown in Table 1. [Table 1]

[0102] (Preparation Example of Amorphous Resin B1) The following materials were placed in a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube under a nitrogen atmosphere. Toluene 100.0 parts Monomer composition 100.0 parts (The monomer composition is a mixture of the following monomers in the ratio shown below.) (Lauryl acrylate 25.0 parts) (Styrene 75.0 parts) Polymerization initiator: 0.5 parts t-butyl peroxypivalate (NOF Corp.: Perbutyl PV) The inside of the reaction vessel was heated to 70°C while stirring at 200 rpm, and polymerization reaction was carried out for 12 hours, to obtain a solution in which the polymer of the monomer composition was dissolved in toluene. Then, the temperature of the solution was lowered to 25°C, and the solution was poured into 1000.0 parts of methanol while stirring, to precipitate the methanol insoluble matter. The obtained methanol insoluble matter was filtered, washed with methanol, and then vacuum dried at 40°C for 24 hours to obtain amorphous resin B1.

[0103] (Preparation Example of Resin C1) The following raw materials were placed in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, and the reaction was carried out at 220° C. under normal pressure for 15 hours, and then further under reduced pressure of 1.3 to 2.6 kPa for 0.5 hours. Terephthalic acid 210.0 parts Isophthalic acid 210.0 parts Bisphenol A-propylene oxide 2 mole adduct 1200.0 parts Potassium oxalate titanate 0.3 parts Thereafter, the temperature was lowered to 180° C., 0.01 parts of trimellitic anhydride was added, and the mixture was reacted at 180° C. for 1.5 hours to obtain Resin C1.

[0104] <Examples of manufacturing treated magnetic materials> Into the ferrous sulfate aqueous solution, 1.00 to 1.10 equivalents of sodium hydroxide solution relative to the iron atom, P2O5 in an amount equivalent to 0.15 mass% of phosphorus atoms relative to the iron atom, and SiO2 in an amount equivalent to 0.50 mass% of silicon atoms relative to the iron atom were mixed. Then, an aqueous solution containing ferrous hydroxide was prepared. The pH of this aqueous solution was adjusted to 8.0, and an oxidation reaction was carried out at 85°C while blowing in air, to prepare a slurry liquid containing seed crystals.

[0105] Next, an aqueous solution of ferrous sulfate was added to this slurry in an amount of 0.90 to 1.20 equivalents relative to the initial amount of alkali (the sodium component of sodium hydroxide). Thereafter, the pH of the slurry was maintained at 7.6, and the oxidation reaction was allowed to proceed while blowing in air, to obtain a slurry containing magnetic iron oxide. The resulting slurry was filtered and washed, and then the aqueous slurry was taken out. At this time, a small amount of the aqueous slurry was sampled and the water content was measured. Next, this water-containing slurry was put into another aqueous medium without drying, and redispersed in a pin mill while stirring and circulating the slurry, and the pH of the redispersion was adjusted to 4.8 with an inorganic acid such as hydrochloric acid. Then, while stirring, 1.6 parts of n-hexyltrimethoxysilane was added as a coupling agent to 100 parts of magnetic iron oxide (the amount of magnetic iron oxide was calculated by subtracting the water content from the water-containing slurry), and hydrolysis was performed. After that, stirring was performed, and the pH of the dispersion was adjusted to 8.6 to perform hydrophobic treatment. The generated hydrophobic magnetic material was filtered with a filter press, washed with a large amount of water, and then dried at 100°C for 15 minutes, and then dried at 90°C for 30 minutes. The resulting particles were then crushed to obtain a treated magnetic material having a volume average particle size of 0.21 μm.

[0106] <Example 1> [Toner production by suspension polymerization method] (Production Example of Toner Particle 1) Lauryl acrylate 15.0 parts Styrene 45.0 parts Treated magnetic material 65.0 parts A mixture of the above materials was prepared. The mixture was placed in an attritor (manufactured by Nippon Coke Corporation) and dispersed at 200 rpm for 2 hours using zirconia beads with a diameter of 5 mm to obtain a raw material dispersion.

[0107] On the other hand, 735.0 parts of ion-exchanged water and 16.0 parts of trisodium phosphate (12-hydrate) were added to a container equipped with a high-speed stirring device homomixer (manufactured by Primix Corporation) and a thermometer, and the temperature was raised to 60 ° C. while stirring at 12000 rpm. An aqueous calcium chloride solution in which 9.0 parts of calcium chloride (2-hydrate) was dissolved in 65.0 parts of ion-exchanged water was added thereto, and the mixture was stirred at 12000 rpm for 30 minutes while maintaining the temperature at 60 ° C. 10% hydrochloric acid was added thereto to adjust the pH to 6.0, and an aqueous medium in which an inorganic dispersion stabilizer containing hydroxyapatite was dispersed in water was obtained.

[0108] Next, the raw material dispersion liquid was transferred to a container equipped with a stirrer and a thermometer, and the temperature was raised to 60° C. while stirring at 100 rpm. ·Crystalline resin A1 40.0 parts Release agent 1 9.0 parts (Release agent 1: DP18 (dipentaerythritol stearate ester wax, melting point 79°C, manufactured by Nippon Seiro Co., Ltd.) The above materials were added thereto and stirred at 100 rpm for 30 minutes while maintaining the temperature at 60°C, and then 9.0 parts of t-butyl peroxypivalate (Perbutyl PV, manufactured by NOF Corp.) was added as a polymerization initiator and stirred for another minute, after which the mixture was poured into the aqueous medium being stirred at 12000 rpm in the high-speed stirring device. Stirring was continued at 12000 rpm for 20 minutes in the high-speed stirring device while maintaining the temperature at 60°C, to obtain a granulation liquid. The granulation liquid was transferred to a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube, and heated to 70° C. while stirring at 150 rpm under a nitrogen atmosphere. A polymerization reaction was carried out at 150 rpm for 12 hours while maintaining the temperature at 70° C., to obtain a toner particle dispersion liquid. The resulting toner particle dispersion was cooled to 45°C while stirring at 150 rpm, and then heat-treated for 5 hours while maintaining the temperature at 45°C. Dilute hydrochloric acid was then added while maintaining the stirring until the pH reached 1.5 to dissolve the dispersion stabilizer. The solid content was filtered off, thoroughly washed with ion-exchanged water, and vacuum-dried at 30°C for 24 hours to obtain toner particles 1.

[0109] (Preparation Example of Toner 1) For the above toner particles, 1:98.0 parts, silica fine particles (hydrophobized with hexamethyldisilazane, number-average particle size of primary particles: 10 nm, BET specific surface area: 170 m) were added as an external additive. 2 The mixture was mixed for 15 minutes at 3000 rpm using a Henschel mixer (manufactured by Nippon Coke Corporation) to obtain toner 1. The physical properties of the obtained toner 1 are shown in Table 3, and the evaluation results are shown in Table 4. [Table 2] In the table, C1 indicates resin C1. [Table 3] In the table, Mw of the toner is the weight average molecular weight Mw of the THF soluble portion of the toner.

[0110] <Examples 2 to 11, 13 to 24, 27, and 28> Toner particles 2 to 11, 13 to 24, 27, and 28 were obtained in the same manner as in Example 1, except that the type and amount of polymerizable monomer used were changed as shown in Table 2. Further, external addition was carried out in the same manner as in Example 1 to obtain toners 2 to 11, 13 to 24, 27, and 28. The physical properties of the toners are shown in Table 3, and the evaluation results are shown in Table 4. From the above analysis, in toners 2 to 11, 13 to 24, 27, and 28, each monomer unit forming crystalline resin A was contained in the same content ratio as in the formulation shown in Table 1. Furthermore, each monomer unit forming amorphous resin B was contained in the same content ratio as in the formulation shown in Table 2.

[0111] <Example 12> [Example of toner production using the pulverization method] ·Crystalline resin A1 96.0 parts ·Amorphous resin B1 4.0 parts Treated magnetic material 25.0 parts Release agent 1 9.0 parts The above materials were premixed in an FM mixer (manufactured by Nippon Coke and Engineering Co., Ltd.), and then melt-kneaded using a twin-screw kneading extruder (Model PCM-30, manufactured by Ikegai Iron Works Co., Ltd.). The obtained kneaded material was cooled, coarsely pulverized with a hammer mill, and then pulverized with a mechanical pulverizer (T-250 manufactured by Turbo Kogyo Co., Ltd.). The obtained finely pulverized powder was classified with a multi-division classifier utilizing the Coanda effect, and toner particles 12 having a weight average particle size (D4) of 6.9 μm were obtained. The toner particles 12 were externally added in the same manner as in Example 1 to obtain toner 12. The physical properties of toner 12 are shown in Table 3, and the evaluation results are shown in Table 4. From the above analysis, in toner 12, each monomer unit forming crystalline resin A1 was contained in the same content ratio as in the formulation used when crystalline resin A1 was produced. Also, each monomer unit forming amorphous resin B1 was contained in the same content ratio as in the formulation used when amorphous resin B1 was produced.

[0112] <Example 25> Toner particles 25 were obtained in the same manner as in Example 12, except that the amounts of the materials used were changed as follows: Further, the same external addition as in Example 1 was carried out on the toner particles 25 to obtain toner 25. The physical properties of the toner are shown in Table 3, and the evaluation results are shown in Table 4. From the above analysis, in toner 25, each monomer unit forming crystalline resin A1 was contained in the same content ratio as in the formulation used when crystalline resin A1 was produced. Also, each monomer unit forming amorphous resin B1 was contained in the same content ratio as in the formulation used when amorphous resin B1 was produced. ·Crystalline resin A1 40.0 parts ·Amorphous resin B1 60.0 parts Treated magnetic material 65.0 parts Release agent 1 9.0 parts

[0113] <Example 26> [Example of toner production using emulsion aggregation method] (Preparation Example of Crystalline Resin Dispersion) Toluene 300.0 parts ·Crystalline resin A1 100.0 parts The above materials were weighed, mixed, and dissolved at 90°C. Separately, 5.0 parts of sodium dodecylbenzenesulfonate and 10.0 parts of sodium laurate were added to 700.0 parts of ion-exchanged water and dissolved by heating at 90° C. Next, the toluene solution and the aqueous solution were mixed and stirred at 7000 rpm using an ultra-high speed stirring device TK ROBOMIX (manufactured by Primix). Further, the mixture was emulsified at a pressure of 200 MPa using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.). After that, the toluene was removed using an evaporator, and the concentration was adjusted with ion-exchanged water to obtain a crystalline resin dispersion liquid with a concentration of 20% crystalline resin A1 fine particles. The 50% particle size (D50) based on volume distribution of the crystalline resin A1 fine particles was measured using a dynamic light scattering particle size distribution meter Nanotrac UPA-EX150 (manufactured by Nikkiso Co., Ltd.) and found to be 0.40 μm.

[0114] (Preparation Example of Amorphous Resin Dispersion) Toluene 300.0 parts ·Amorphous resin B1 100.0 parts The above materials were weighed, mixed, and dissolved at 90°C. Separately, 700.0 parts of ion-exchanged water, 5.0 parts of sodium dodecylbenzenesulfonate, 10.0 parts of sodium laurate was added and dissolved by heating at 90° C. The toluene solution and the aqueous solution were then mixed together and stirred at 7000 rpm using an ultra-high speed stirring device TK Robomix (manufactured by Primix). Further, the mixture was emulsified at a pressure of 200 MPa using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.). After that, toluene was removed using an evaporator, and the concentration was adjusted with ion-exchanged water to obtain an amorphous resin dispersion with a concentration of amorphous resin fine particles of 20%. The 50% particle size (D50) based on volume distribution of the amorphous resin fine particles was measured using a dynamic light scattering particle size distribution analyzer Nanotrac UPA-EX150 (manufactured by Nikkiso Co., Ltd.) and found to be 0.38 μm.

[0115] (Preparation example of release agent dispersion) Release agent 1 100.0 parts Anionic surfactant Neogen RK (Daiichi Kogyo Seiyaku) 5.0 parts Ion-exchanged water 395.0 parts The above materials were weighed and placed in a mixing vessel equipped with an agitator, then heated to 90°C and circulated through a Clearmix W Motion (manufactured by M Technique) for 60 minutes to perform dispersion processing. The dispersion processing conditions were as follows: Rotor outer diameter 3cm Clearance 0.3mm Rotor speed: 19000 r / min Screen rotation speed: 19000 r / min After the dispersion treatment, the mixture was cooled to 40° C. under cooling treatment conditions of a rotor rotation speed of 1000 r / min, a screen rotation speed of 0 r / min, and a cooling rate of 10° C. / min, to obtain a release agent dispersion liquid with a release agent fine particle concentration of 20%. The 50% particle size (D50) based on the volume distribution of the release agent fine particles was measured using a dynamic light scattering particle size distribution meter Nanotrac UPA-EX150 (manufactured by Nikkiso Co., Ltd.) and found to be 0.15 μm.

[0116] (Preparation example of magnetic dispersion liquid) Treated magnetic material 65.0 parts Anionic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku) 7.5 parts Ion-exchanged water 442.5 parts The above materials were weighed, mixed, dissolved, and dispersed for 1 hour using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.) to obtain a magnetic material dispersion with a treated magnetic material concentration of 12.6%. The 50% particle size (D50) based on the volume distribution of the treated magnetic material was measured using a dynamic light scattering particle size distribution analyzer Nanotrac UPA-EX150 (manufactured by Nikkiso Co., Ltd.) and found to be 0.20 μm.

[0117] (Toner 26 manufacturing example) ·Crystalline resin dispersion 200.0 parts ·Amorphous resin dispersion 300.0 parts Release agent dispersion 45.0 parts ·Magnetic material dispersion liquid 65.0 parts Ion-exchanged water 160.0 parts The above materials were put into a round stainless steel flask and mixed. Then, they were dispersed for 10 minutes at 5000 rpm using a homogenizer Ultra Turrax T50 (manufactured by IKA). After adding a 1.0% nitric acid aqueous solution and adjusting the pH to 3.0, the mixture was heated to 58°C in a heating water bath using a stirring blade while appropriately adjusting the rotation speed so that the mixture was stirred. The volume average particle size of the formed aggregated particles was measured using a Coulter Multisizer III. When it was confirmed that aggregated particles with a weight average particle size (D4) of 6.0 μm were formed, the pH was adjusted to 9.0 using a 5% aqueous sodium hydroxide solution. Then, while continuing to stir, the mixture was heated to 75° C. The mixture was then held at 75° C. for 1 hour to fuse the aggregated particles. Thereafter, the mixture was cooled to 45° C. and heat-treated for 5 hours. After that, the mixture was cooled to 25° C., filtered, separated into solid and liquid, and washed with ion-exchanged water. After washing, the mixture was dried using a vacuum dryer to obtain toner particles 26 having a weight average particle size (D4) of 6.1 μm. The toner particles 26 were externally added in the same manner as in Example 1 to obtain toner 26. The physical properties of toner 26 are shown in Table 3, and the evaluation results are shown in Table 4. From the above analysis, in toner 26, each monomer unit forming crystalline resin A1 was contained in the same content ratio as in the formulation used when crystalline resin A1 was produced. Also, each monomer unit forming amorphous resin B1 was contained in the same content ratio as in the formulation used when amorphous resin B1 was produced.

[0118] <Comparative Examples 1 to 3, 5 to 9> Comparative toner particles 1 to 3 and 5 to 9 were obtained in the same manner as in Example 1, except that the type and amount of polymerizable monomer used were changed as shown in Table 2. Further, external addition was carried out in the same manner as in Example 1 to obtain comparative toners 1 to 3 and 5 to 9. The physical properties of the toners are shown in Table 3, and the evaluation results are shown in Table 4. In comparative toners 1 to 3 and 5 to 9, each monomer unit forming crystalline resin A was contained in the same content ratio as in the formulation shown in Table 1. Furthermore, each monomer unit forming amorphous resin B was contained in the same content ratio as in the formulation shown in Table 2.

[0119] <Comparative Example 4> Comparative toner particles 4 were obtained in the same manner as in Example 12, except that the types and amounts of the materials used were changed as follows. Further, external addition was carried out in the same manner as in Example 1 to obtain Comparative Toner 4. The physical properties of the toner are shown in Table 3, and the evaluation results are shown in Table 4. In Comparative Toner 4, each monomer unit forming Crystalline Resin A was contained in the same content ratio as in the formulation shown in Table 1. ·Crystalline resin A1 100.0 parts Treated magnetic material 65.0 parts Release agent 1 9.0 parts

[0120] <Comparative Example 10> Comparative toner particles 10 were obtained in the same manner as in Example 12, except that the types and amounts of the materials used were changed as follows. Further, external addition was carried out in the same manner as in Example 1 to obtain Comparative Toner 10. The physical properties of the toner are shown in Table 3, and the evaluation results are shown in Table 4. In Comparative Toner 10, each monomer unit forming Crystalline Resin A was contained in the same content ratio as in the formulation shown in Table 1. ·Crystalline resin A1 80.0 parts ·Resin C1 20.0 parts Treated magnetic material 65.0 parts Release agent 1 9.0 parts

[0121] <Toner Evaluation Method> <1> Low temperature fixability The process cartridge filled with toner was left for 48 hours at 25°C and 40% RH. Using an LBP-712Ci that had been modified so that it could operate even without the fixing unit, an unfixed image was printed with an image pattern in which 9 10mm x 10mm square images were evenly arranged on the entire transfer paper. The amount of toner on the transfer paper was 0.80mg / cm. 2 The fixing start temperature was evaluated. The transfer paper was A4 size paper ("Prover Bond paper": 105 g / m 2 ,centre (manufactured by Oxford River) was used. The fixing unit was an external fixing unit that had been removed from the LBP-712Ci and was designed to operate outside the laser beam printer. The fixing temperature of the external fixing unit was raised in 5°C increments from 90°C, and fixing was performed at a process speed of 240mm / sec. The fixed image was visually observed, and the lowest temperature at which no cold offset occurred was defined as the fixing start temperature, and the low-temperature fixing ability was evaluated according to the following criteria. The evaluation results are shown in Table 4. [Evaluation Criteria] A: Fixing start temperature is 100℃ or less B: Fixing start temperature is 105℃ or higher and 110℃ or lower C: Fixing start temperature is 115℃ or higher and 120℃ or lower D: Fixing start temperature is 125°C or higher

[0122] <2> Image Durability To evaluate image durability, image folding evaluation was performed. The process cartridge filled with toner was left for 48 hours at a temperature of 15.0°C and a humidity of 10% RH. A 50mm x 50mm solid image was printed in the center of the transfer paper using an LBP-712Ci printer. The image was folded in the center 20 times in succession under the above environment, and the extent to which the solid image peeled off was judged visually. The evaluation was based on the following criteria. The evaluation results are shown in Table 5. [Evaluation Criteria] A: No peeling of the image is observed. B: Slight peeling of the image was observed at the bent portion. C: No problem in practical use, but image peeling was observed at the folded portion. D: Image peeling was observed in areas other than the bent areas.

[0123] <3> Heat resistant storage stability To evaluate the stability during storage, the heat resistance storage stability was evaluated. 5 g of the toner was placed in a 100 ml resin cup and left for 3 days in an environment of 50°C temperature and 40 RH%, after which the degree of cohesion of the toner was measured as follows and evaluated according to the following criteria. The measuring device used was a "Powder Tester" (manufactured by Hosokawa Micron Corporation) with a digital display vibration meter "DigiVibro MODEL 1332A" (manufactured by Showa Sokki Co., Ltd.) connected to the side of the vibration table. A sieve with a mesh size of 38 μm (400 mesh), a sieve with a mesh size of 75 μm (200 mesh), and a sieve with a mesh size of 150 μm (100 mesh) were placed on top of each other on the vibration table of the powder tester from the bottom up. The measurements were carried out in an environment of 23°C and 60% RH as follows. (1) The vibration amplitude of the vibration table was adjusted in advance so that the displacement value on the digital display vibrometer was 0.60 mm (peak-to-peak). (2) The toner that had been left for 10 days as described above was then left for 24 hours in an environment of 23° C. and 60% RH, and 5.00 g of the toner was precisely weighed out and gently placed on the top sieve with 150 μm openings. (3) After the sieves were vibrated for 15 seconds, the mass of the toner remaining on each sieve was measured, and the degree of cohesion was calculated according to the following formula. The evaluation results are shown in Table 4. Cohesion degree (%)= {(Sample mass (g) on ​​150 μm mesh sieve) / 5.00(g)}×100 + {(Sample mass (g) on ​​75 μm mesh sieve) / 5.00(g)} x 100 x 0.6 + {(Sample mass on 38 μm mesh sieve (g)) / 5.00 (g)} x 100 x 0.2 [Evaluation Criteria] A: Coagulation rate is less than 10.0% B: The degree of aggregation is 10.0% or more and less than 15.0%. C: The degree of aggregation is 15.0% or more and less than 20.0%. D: Coagulation degree is 20.0% or more

[0124] <4> Developability Using an LBP-712Ci, 5,000 images with a printing rate of 2% were printed out using the printer in a high temperature and high humidity environment (temperature 32.5°C, humidity 80% RH). After leaving it for 7 days, one image with a white background was printed out. The reflectance of the obtained image was measured using a reflection densitometer (Reflectometer Model TC-6DS, manufactured by Tokyo Denshoku Co., Ltd.). An amber filter was used for the measurement. The worst reflectance of the white background was defined as Ds (%), and the reflectance of the transfer material before image formation was defined as Dr (%). Dr-Ds was defined as fog, and evaluation was performed according to the following criteria. The evaluation results are shown in Table 4. [Evaluation Criteria] A: Fog is less than 1.0% B: Fog is 1.0% or more and less than 3.0% C: Fog is 3.0% or more and less than 5.0% D: Fog is 5.0% or more [Table 4]

[0125] The present disclosure relates to the following configurations. (Configuration 1) A magnetic toner having toner particles containing a magnetic material, a crystalline resin A, and an amorphous resin B, The crystalline resin A has a monomer unit (a) represented by the following formula (a): The amorphous resin B has a monomer unit (b) represented by the following formula (b): The content of the crystalline resin A in the toner is 6.2 to 77.0% by mass, the sum of the contents of the crystalline resin A and the amorphous resin B in the toner is 30.0% by mass or more; The content of the monomer unit (a) in the crystalline resin A is 50.0 to 100.0 mass %, The SP value of the crystalline resin A is SPA [(J / cm 3 ) 0.5 ], The SP value of the amorphous resin B is SPB [(J / cm 3 ) 0.5 ], The SPA and the SPB are 0.15≦SPB-SPA≦2.00 A toner characterized by satisfying the above requirements. [ka] (In formula (a), R 1 represents a hydrogen atom or a methyl group, L 1 represents a single bond or a divalent linking group, and m represents an integer of 15 to 35. [ka] (In formula (b), R 2 represents a hydrogen atom or a methyl group, L 2 represents a single bond or a divalent linking group, and n represents an integer of 10 to 30. (Configuration 2) The toner according to configuration 1, wherein the content of the amorphous resin B in the toner is 2.7 to 63.0% by mass. (Configuration 3) 3. The toner according to configuration 1 or 2, wherein the content of the amorphous resin B in the toner is 20.0 to 55.0% by mass. (Configuration 4) The toner according to any one of configurations 1 to 3, wherein the content of the monomer unit (b) in the amorphous resin B is 2.7 to 47.0% by mass. (Configuration 5) The toner according to any one of configurations 1 to 4, wherein the content of the monomer unit (b) in the amorphous resin B is 5.0 to 40.0% by mass. (Configuration 6) The toner according to any one of configurations 1 to 5, wherein the amorphous resin B has a glass transition temperature of 30.0 to 90.0°C. (Configuration 7) The toner according to any one of configurations 1 to 6, wherein the monomer unit (a) is a monomer unit (a-1) represented by the following formula (a-1): [ka] (In formula (a-1), R 1 represents a hydrogen atom or a methyl group, and m represents an integer of 15 to 35. (Configuration 8) The toner according to any one of configurations 1 to 7, wherein the content of the crystalline resin A in the toner is 10.0 to 40.0% by mass. (Configuration 9) The toner according to any one of configurations 1 to 8, wherein the content of the monomer unit (a) in the crystalline resin A is 65.0 to 90.0% by mass. (Configuration 10) 10. The toner according to any one of configurations 1 to 9, wherein the monomer unit (b) is a monomer unit (b-1) represented by the following formula (b-1): [ka] (In formula (b-1), R 2represents a hydrogen atom or a methyl group, and n represents an integer of 10 to 30. (Configuration 11) 11. The toner according to any one of configurations 1 to 10, wherein the content of the magnetic material in the toner is 7.0 to 45.0% by mass.

Claims

1. A magnetic toner having toner particles containing a magnetic material, a crystalline resin A, and an amorphous resin B, The crystalline resin A has a monomer unit (a) represented by the following formula (a): The amorphous resin B has a monomer unit (b) represented by the following formula (b): The content of the crystalline resin A in the toner is 6.2 to 77.0% by mass, the sum of the contents of the crystalline resin A and the amorphous resin B in the toner is 30.0% by mass or more; The content ratio of the monomer unit (a) in the crystalline resin A is 50.0 to 100.0 mass %, The SP value of the crystalline resin A is SPA [(J / cm ３ ) ０．５ ], The SP value of the amorphous resin B is SPB [(J / cm ３ ) ０．５ ], The SPA and the SPB, 0.15≦SPB−SPA≦2.00 A toner characterized by satisfying the above requirements. (In formula (a), R １ represents a hydrogen atom or a methyl group; L １ represents a single bond or a divalent linking group, and m represents an integer of 15 to 35. (In formula (b), R ２ represents a hydrogen atom or a methyl group; L ２ represents a single bond or a divalent linking group, and n represents an integer of 10 to 30.

2. 2. The toner according to claim 1, wherein the content of the amorphous resin B in the toner is 2.7 to 63.0% by mass.

3. 3. The toner according to claim 1, wherein the content of the amorphous resin B in the toner is 20.0 to 55.0% by mass.

4. 3. The toner according to claim 1, wherein the content of the monomer unit (b) in the amorphous resin B is 2.7 to 47.0% by mass.

5. 3. The toner according to claim 1, wherein the content of the monomer unit (b) in the amorphous resin B is 5.0 to 40.0% by mass.

6. 3. The toner according to claim 1, wherein the amorphous resin B has a glass transition temperature of 30.0 to 90.0° C.

7. 3. The toner according to claim 1, wherein the monomer unit (a) is a monomer unit (a-1) represented by the following formula (a-1): (In formula (a-1), R １ represents a hydrogen atom or a methyl group, and m represents an integer of 15 to 35.

8. 3. The toner according to claim 1, wherein the content of the crystalline resin A in the toner is 10.0 to 40.0% by mass.

9. 3. The toner according to claim 1, wherein the content of the monomer unit (a) in the crystalline resin A is 65.0 to 90.0% by mass.

10. 3. The toner according to claim 1, wherein the monomer unit (b) is a monomer unit (b-1) represented by the following formula (b-1): (In formula (b-1), R ２ represents a hydrogen atom or a methyl group, and n represents an integer of 10 to 30.

11. 3. The toner according to claim 1, wherein the content of the magnetic material in the toner is 7.0 to 45.0% by mass.

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