Toner for electrostatic charge image development, two-component developer for electrostatic charge image development, image forming method, image forming system, and image evaluation method

Abstract

To provide toner for electrostatic charge image development that improves adhesion between an image and a resin-made recording medium and reduces uneven glossiness of an image.SOLUTION: In toner for electrostatic charge image development of the present invention, a binder resin contains hybrid amorphous polyester. A content of the hybrid amorphous polyester is within a range of 5 to 50 pts.mass based on 100 pts.mass of the binder resin. The hybrid amorphous polyester has an amorphous polyester segment and a vinyl resin segment. The amorphous polyester segment is a condensed polymer of a polyvalent carboxylic acid and polyhydric alcohol. The polyhydric alcohol includes aliphatic polyhydric alcohol. The vinyl resin segment includes a constitutional unit derived from a vinyl monomer, a content of the vinyl resin segment is within a range of 3 to 30 pts.mass based on 100 pts.mass of the amorphous polyester segment.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a toner for developing electrostatic images, a two-component developer for developing electrostatic images, an image forming method, an image forming system, and an image evaluation method. [Background technology]

[0002] As copiers and printers become more widespread, toners for developing electrostatic images used in image formation are required to have higher performance. Hereinafter, toners for developing electrostatic images will also be simply referred to as "toner." In recent years, recording media have become more diverse, and there is a growing demand for image formation on resin recording media such as film. Disclosed technologies for toners suitable for resin recording media include a toner containing fine particles of polypropylene wax (Patent Document 1) and a toner containing a binder resin having a constituent portion derived from polypropylene resin (Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-218448 [Patent Document 2] Japanese Patent Application Publication No. 2019-204030 Summary of the Invention [Problem to be solved by the invention]

[0004] Resin recording media differ greatly from paper media in terms of physical properties such as surface shape, polarity, and air permeability. Therefore, an image formed on a resin recording medium using a toner suitable for paper media is prone to a decrease in adhesion between the toner image and the resin recording medium, and the image is particularly prone to peeling when an external force is applied to the image.

[0005] On the other hand, it has been found that image-formed products in which the toner image has high adhesion to the resin recording medium are prone to deterioration in image quality, and specifically, prone to occurrence of uneven gloss.

[0006] The toners disclosed in Patent Documents 1 and 2 improve the adhesion between the image and the resin recording medium, but have the problem of being prone to uneven gloss.

[0007] The present invention has been made in consideration of the above problems and circumstances, and an object of the present invention is to provide a toner for developing electrostatic images that has improved adhesion to a resin recording medium and reduces uneven gloss of the image. [Means for solving the problem]

[0008] The present inventors have investigated the causes of the above problems in order to solve them. As a result, they have found that the problems can be solved by adjusting the adhesion area ratio and the peak density Spd within appropriate ranges. As one means for solving the problems, they have found that by incorporating a specific amorphous polyester as a binder resin into the toner base particles, the adhesion of the image-formed product to a resin recording medium can be improved and uneven gloss of the image can be reduced, which led to the present invention. That is, the above-mentioned problems of the present invention are solved by the following means.

[0009] 1. A toner for developing electrostatic images, comprising toner base particles containing a binder resin, the binder resin contains a hybrid amorphous polyester, the content of the hybrid amorphous polyester is within a range of 5 to 50 parts by mass relative to 100 parts by mass of the binder resin; the hybrid amorphous polyester has an amorphous polyester segment and a vinyl resin segment, the amorphous polyester segment is a condensation polymer of a polycarboxylic acid and a polyhydric alcohol, the polyhydric alcohol comprises an aliphatic polyhydric alcohol, the vinyl resin segment contains a structural unit derived from a vinyl monomer, The content of the vinyl resin segment is within a range of 3 to 30 parts by mass relative to 100 parts by mass of the amorphous polyester segment. 1. A toner for developing electrostatic images, comprising:

[0010] 2. The aliphatic polyhydric alcohol is a non-alicyclic aliphatic polyhydric alcohol having 5 or more carbon atoms. 2. The toner for developing electrostatic images according to claim 1,

[0011] 3. The vinyl monomer includes styrenes and (meth)acrylic esters. 3. The toner for developing electrostatic images according to claim 1 or 2.

[0012] 4. The binder resin contains a hybrid crystalline polyester, the hybrid crystalline polyester has a crystalline polyester segment and a vinyl resin segment, the crystalline polyester segment is a condensation polymer of a polycarboxylic acid and a polyhydric alcohol, The vinyl resin segment contains a structural unit derived from a vinyl monomer. 3. The toner for developing electrostatic images according to claim 1 or 2.

[0013] 5. Has a core-shell structure The shell layer contains the hybrid amorphous polyester. 3. The toner for developing electrostatic images according to claim 1 or 2.

[0014] 6. Has a core-shell structure The core particles contain styrene-acrylic resin. 3. The toner for developing electrostatic images according to claim 1 or 2.

[0015] 7. On a resin recording medium, adhesion amount 4g / m 2 When the above solid image is formed, The density of the peaks on the surface of the solid image is 5000 to 100000 mm -2 is within the range of The adhesion area ratio at the interface between the resin recording medium and the solid image is within the range of 60 to 95%. 3. The toner for developing electrostatic images according to claim 1 or 2.

[0016] 8. A toner for developing electrostatic images according to item 1 or 2 and a carrier are included. A two-component developer for developing electrostatic images.

[0017] 9. An electrophotographic image forming method including a step of fixing an electrostatic image developing toner on a resin recording medium to form an image, Adhesion amount: 4g / m 2 When creating the above solid images, The density of the peaks on the surface of the solid image is 5000 to 100000 mm -2 is within the range of The adhesion area ratio at the interface between the resin recording medium and the solid image is within the range of 60 to 95%. An image forming method comprising:

[0018] 10. An electrophotographic image forming method including a step of fixing an electrostatic image developing toner on a resin recording medium to form an image, Adhesion amount 10g / m on 50μm thick polyethylene terephthalate film 2 When creating a solid image, The density of the peaks on the surface of the solid image is 5000 to 100000 mm -2 is within the range of The adhesion area ratio at the interface between the polyethylene terephthalate film and the solid image is within the range of 60 to 95%. An image forming method comprising:

[0019] 11. Fixing occurs when the fixing temperature is within the range of 100 to 230°C, the fixing pressure is within the range of 2500 to 3000 Pa, and the conveyance speed of the resin recording medium is within the range of 155 to 665 mm / sec. 11. The image forming method according to item 9 or 10,

[0020] 12. The resin recording medium is a continuous-feed medium. 11. The image forming method according to item 9 or 10,

[0021] 13. The thickness of the resin recording medium is 75 μm or less. 11. The image forming method according to item 9 or 10,

[0022] 14. The resin recording medium is surface-treated. 11. The image forming method according to item 9 or 10,

[0023] 15. An electrophotographic image forming system that forms an image by fixing electrostatic image developing toner on a resin recording medium, Adhesion amount 10g / m on 50μm thick polyethylene terephthalate film 2 When creating a solid image, The density of the peaks on the surface of the solid image is 5000 to 100000 mm -2 Within the range of a means for controlling the adhesion area ratio at the interface between the solid image and the polyethylene terephthalate film to be within a range of 60 to 95%; An image forming system comprising:

[0024] 16. An image evaluation method for evaluating an image formed by fixing a toner for developing an electrostatic image on a resin recording medium, comprising: measuring the density of peaks on the surface of the image; The measured value of the peak density is 5000 to 100000 mm -2 determining whether the range is a step of measuring an adhesion area ratio at the interface between the resin recording medium and the image; and and determining whether the measured value of the adhesion area ratio is within a range of 60 to 95%. An image evaluation method comprising: [Effects of the Invention]

[0025] By the above means of the present invention, it is possible to provide a toner for developing electrostatic images which has improved adhesion to a resin recording medium and reduces uneven gloss of the image.

[0026] The mechanism by which the effects of the present invention are manifested or the mechanism of action is not clear, but is speculated as follows.

[0027] To ensure high adhesion and resistance to peeling even when an external force is applied to a toner image, it is important to enhance the adhesion between the toner image and the recording medium and to adjust the surface condition of the toner image. It has been found that the adhesion area ratio between the image and the recording medium has a significant effect on the former, while the peak density (Spd) of the image surface has a significant effect on the latter. The higher the adhesion area ratio, the better the adhesion at the interface between the two objects. The peak density (Spd) refers to the number of peaks on the image surface per unit area, but high adhesion cannot be achieved if the value is too high or too low. If the peak density (Spd) is too low, the contact area between the image and the adhesive increases when an adhesive material is attached to and peeled from the toner image, making the image more likely to peel. On the other hand, if the peak density (Spd) is too high, the number of peaks on the image where stress is concentrated increases when the image is scratched with a sharp object, making the image more susceptible to stress and peeling. Therefore, by increasing the adhesion area ratio between the image and the recording medium and adjusting the peak density Spd to an appropriate range, high adhesion that is resistant to peeling by adhesive materials and scratching can be obtained.

[0028] On the other hand, when forming a toner image on a resin recording medium, if the adhesive area ratio is too high, gloss unevenness is likely to occur. This is because, when the toner is fixed, the air in the toner layer thermally expands, but in a resin recording medium, the air in the toner layer does not pass through the resin recording medium and is not discharged to the outside, which makes it more likely to cause small explosions or the formation of an image containing an air layer. Therefore, it was found that by adjusting the adhesive area ratio to a level that does not reduce adhesiveness too much, the air in the toner layer can be discharged to the outside, thereby reducing gloss unevenness.

[0029] Therefore, by adjusting the adhesion area ratio and the peak density Spd to fall within appropriate ranges, it is possible to improve the adhesion and reduce uneven gloss in the image.

[0030] It is believed that the adhesion area ratio and the peak density Spd can be adjusted to an appropriate range depending on the composition of the binder resin contained in the toner base particles, the conditions for toner fixing, the type of fixing member, and the like.

[0031] The reason why the toner according to the present invention achieves the above-described effects is unclear, but is presumed to be as follows: The binder resin according to this embodiment contains an amorphous polyester, which is a condensation polymer of a polycarboxylic acid and a polyhydric alcohol. The polyhydric alcohol includes an aliphatic polyhydric alcohol. It is believed that a hydrophobic interaction occurs between the hydrocarbon portion (hydrophobic portion) of the polyhydric alcohol component and the highly hydrophobic resin recording medium, resulting in adhesion. Furthermore, the skeleton of an aliphatic polyhydric alcohol is more flexible than the skeleton of the commonly used aromatic polyhydric alcohol, which improves the melting property of the amorphous polyester. As a result, it is believed that when an image is formed on the resin recording medium, the adhesion area ratio at the interface between the resin recording medium and the image can be improved.

[0032] The hybrid amorphous polyester according to this embodiment has vinyl resin segments containing structural units derived from vinyl monomers. The vinyl resin segments are chemically bonded to the amorphous polyester segments, and the vinyl resin segments are dispersed relatively uniformly within the amorphous polyester segments. The presence of vinyl resin segments with different melting properties and polarity dispersed within the amorphous polyester segments causes non-uniformity in the melting properties of the surface of the toner image and in the releasability from the fixing member, which is thought to result in the formation of mountain-like protrusions on the surface of the toner image. By adjusting the content of the vinyl resin segments to within a range of 3 to 30 parts by mass per 100 parts by mass of the amorphous polyester segments, it is thought that the non-uniformity can be adjusted, and mountain-like protrusions are appropriately formed.

[0033] The reason why the fixing conditions according to the present invention achieve the above-described effects is unclear, but is presumed to be as follows: If the fixing temperature is too high, the elasticity of the vinyl resin segment is significantly reduced, and the difference in melting properties between it and the amorphous polyester segment is reduced, making it difficult to form mountain-shaped protrusions on the surface of the toner image. On the other hand, if the fixing temperature is too low, the melting properties of the binder resin are reduced, and the adhesion area ratio is likely to decrease. Therefore, it is believed that adjusting the fixing temperature can prevent an excessive decrease in the melting properties of the vinyl resin segment, thereby enabling the formation of appropriate mountain-shaped protrusions on the surface of the toner image, and also prevent an excessive decrease in the melting properties of the binder resin, thereby achieving an appropriate adhesion area ratio. Furthermore, increasing the fixing pressure increases the adhesive strength between the toner image and the recording medium, thereby increasing the adhesion area ratio. Increasing the conveying speed increases the adhesive strength between the toner image and the fixing member, thereby increasing the peak density Spd. Therefore, it is believed that adjusting the fixing pressure and conveying speed can adjust the respective adhesive strengths, thereby adjusting the adhesion area ratio and the peak density Spd.

[0034] Therefore, for the above reasons, it is believed that an image having an adhesive area ratio and peak density Spd within an appropriate range can be formed, and both improved adhesiveness and reduced gloss unevenness can be achieved. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 is a schematic cross-sectional view of an example of an image forming apparatus in which a resin recording medium is in the form of a sheet. [Figure 2] FIG. 1 is a schematic cross-sectional view of an example of an image forming apparatus in which a resin recording medium is in a roll form. [Figure 3] FIG. 1 is an explanatory diagram of a tape peeling test. [Figure 4] FIG. 1 is an explanatory diagram of a scratch test. DETAILED DESCRIPTION OF THE INVENTION

[0036] The electrostatic image developing toner of the present invention is a toner for developing electrostatic images comprising toner base particles containing a binder resin. The binder resin contains a hybrid amorphous polyester. The content of the hybrid amorphous polyester is within a range of 5 to 50 parts by mass per 100 parts by mass of the binder resin. The hybrid amorphous polyester has an amorphous polyester segment and a vinyl resin segment. The amorphous polyester segment is a condensation polymer of a polycarboxylic acid and a polyhydric alcohol. The polyhydric alcohol contains an aliphatic polyhydric alcohol. The vinyl resin segment contains a constituent unit derived from a vinyl monomer. The content of the vinyl resin segment is within a range of 3 to 30 parts by mass per 100 parts by mass of the amorphous polyester segment. This feature is a technical feature common to or corresponding to the following embodiments.

[0037] In an embodiment of the present invention, from the viewpoint of improving adhesion to a resin recording medium, the aliphatic polyhydric alcohol is preferably a non-alicyclic aliphatic polyhydric alcohol having 5 or more carbon atoms.

[0038] In an embodiment of the present invention, from the viewpoint of achieving both improved adhesion to a resin recording medium and reduced gloss unevenness, the vinyl monomer preferably contains styrenes and (meth)acrylic acid esters.

[0039] In an embodiment of the present invention, from the viewpoint of improving adhesion to a resin recording medium, it is preferred that the binder resin contains a hybrid crystalline polyester, the hybrid crystalline polyester has a crystalline polyester segment and a vinyl resin segment, the crystalline polyester segment is a condensation polymer of a polycarboxylic acid and a polyhydric alcohol, and the vinyl resin segment contains a constituent unit derived from a vinyl monomer.

[0040] In an embodiment of the present invention, from the viewpoint of achieving both improved adhesion to a resin recording medium and reduced gloss unevenness, it is preferred that the toner has a core-shell structure, the shell layer contains the hybrid amorphous polyester, and the core particles contain a styrene-acrylic resin.

[0041] In an embodiment of the present invention, from the viewpoint of achieving both improved adhesion to a resin recording medium and reduced gloss unevenness, a coating amount of 4 g / m is applied to the resin recording medium. 2 When the above solid image is formed, the density of the peaks on the surface of the solid image is 5000 to 100000 mm -2 and the adhesion area ratio at the interface between the resin recording medium and the solid image is preferably within a range of 60 to 95%.

[0042] The two-component developer for developing electrostatic images of the present invention is characterized by containing the above-mentioned toner for developing electrostatic images and a carrier.

[0043] The image forming method of the present invention is an electrophotographic image forming method including a step of fixing an electrostatic image developing toner on a resin recording medium to form an image. 2 When the above solid image is created, the density of the peaks on the surface of the solid image is 5000 to 100000 mm -2 and the adhesion area ratio at the interface between the resin recording medium and the solid image is within the range of 60 to 95%.

[0044] The image forming method of the present invention is an electrophotographic image forming method including a step of fixing an electrostatic image developing toner on a resin recording medium to form an image. 2 When a solid image is created, the density of the peaks on the surface of the solid image is 5000 to 100000 mm -2 and the adhesion area ratio at the interface between the polyethylene terephthalate film and the solid image is within the range of 60 to 95%.

[0045] In an embodiment of the present invention, from the viewpoint of achieving both improved adhesion to the resin recording medium and reduced gloss unevenness, it is preferable that fixing is performed at a fixing temperature in the range of 100 to 230°C, a fixing pressure in the range of 2500 to 3000 Pa, and a conveying speed of the resin recording medium in the range of 155 to 665 mm / sec.

[0046] In an embodiment of the present invention, from the viewpoint of transportability and handling when printing an image formed on a resin recording medium, the resin recording medium is preferably a continuous-feed medium.

[0047] In an embodiment of the present invention, from the viewpoint of improving adhesion to the resin recording medium, the thickness of the resin recording medium is preferably 75 μm or less.

[0048] In an embodiment of the present invention, from the viewpoint of improving adhesion to the resin recording medium, the resin recording medium is preferably surface-treated.

[0049] The image forming system of the present invention is an electrophotographic image forming system in which an image is formed by fixing an electrostatic image developing toner on a resin recording medium. 2 When a solid image is created, the density of the peaks on the surface of the solid image is set to 5000 to 100,000 mm -2and a means for adjusting the adhesion area ratio at the interface between the solid image and the polyethylene terephthalate film to within a range of 60 to 95%.

[0050] The image evaluation method of the present invention is an image evaluation method for evaluating an image formed by fixing a toner for developing an electrostatic image on a resin recording medium, comprising the steps of: measuring the peak density of peaks on the surface of the image; -2 a step of measuring the adhesion area ratio at the interface between the resin recording medium and the image; and a step of determining whether the measured value of the adhesion area ratio is within the range of 60 to 95%.

[0051] Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the disclosed embodiments. In this application, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0052] 1. Composition of electrostatic image developing toner The toner for developing electrostatic images according to this embodiment includes toner base particles containing a binder resin. The binder resin includes a hybrid amorphous polyester. The content of the hybrid amorphous polyester is within a range of 5 to 50 parts by mass relative to 100 parts by mass of the binder resin. The hybrid amorphous polyester has an amorphous polyester segment and a vinyl resin segment. The amorphous polyester segment is a condensation polymer of a polycarboxylic acid and a polyhydric alcohol. The polyhydric alcohol includes an aliphatic polyhydric alcohol. The vinyl resin segment includes a constituent unit derived from a vinyl monomer. The content of the vinyl resin segment is within a range of 3 to 30 parts by mass relative to 100 parts by mass of the amorphous polyester segment.

[0053] In this specification, toner for developing electrostatic images is also simply referred to as "toner." The toner includes toner base particles. It is preferable that external additives are attached to the surfaces of the toner base particles. Furthermore, "toner base particles" refers to the substance that constitutes the base of "toner particles." "Toner base particles" become "toner particles" when external additives are added. Furthermore, "toner" refers to an aggregate of toner particles.

[0054] (1) Toner base particles The "toner base particles" according to the present invention preferably contain binder resins, colorants, release agents, charge control agents, and the like, as required. The binder resin, the release agent, the colorant, and the charge control agent, which are the components of the toner base particles, will be described below.

[0055] (1.1) Binder resin The toner base particles contain a binder resin, which allows the toner to be fixed onto the recording medium. In this embodiment, the binder resin contains an amorphous polyester, which is a condensation polymer of a polycarboxylic acid and a polyhydric alcohol. In addition, the binder resin may contain an amorphous resin other than the amorphous polyester and a crystalline resin, as necessary.

[0056] (Method for analyzing resin composition) The composition of each resin contained in the toner base particles can be analyzed by, for example, pyrolysis gas chromatography mass spectrometry (GC / MS). Specifically, the amount can be determined by the standard addition method using a column and a detector that have been confirmed to be capable of detecting a monomer having a specific structure.

[0057] An example of detailed pyrolysis conditions and GC / MS measurement conditions is shown below. (Pyrolysis conditions) Measurement device: PY-2020iD (Frontier Labs, Inc.) Measurement mass: 0.1 mg Heating temperature: 550℃ Heating time: 0.5 minutes

[0058] (GC / MS measurement conditions) Measuring device: QP2010 (Shimadzu Corporation) Column: UltraALLOY-5 (inner diameter: 0.25 mm, length: 30 m, thickness: 0.25 μm, manufactured by Frontier Labs) Temperature range: 40℃ to 320℃ (maintain at 320℃) Heating rate: 20°C / min

[0059] (1.1.1) Amorphous resin In the present invention, "exhibiting amorphousness" means that the material has a glass transition temperature (Tg) but no melting point in an endothermic curve obtained by differential scanning calorimetry (DSC). In other words, it means that there is no clear endothermic peak when the temperature is increased. A clear endothermic peak means an endothermic peak with a half-width of 15°C or less in an endothermic curve when the temperature is increased at a rate of 10°C / min.

[0060] As the amorphous resin, in addition to the amorphous polyester, a known amorphous resin may be used in combination. Examples of the amorphous resin other than the amorphous polyester include vinyl resin, polybutylene succinate, urethane resin, and urea resin.

[0061] Vinyl resins offer a high degree of resin design freedom and allow for easy control of viscoelasticity. This facilitates achieving both low-temperature fixability and fixation separation. The binder resin according to this embodiment preferably contains a vinyl resin in addition to an amorphous polyester. The vinyl resin can be the same resin as the vinyl resin segment described below. The vinyl resin used in combination with an amorphous polyester as an amorphous resin is not chemically bonded to the amorphous polyester but partially approaches the amorphous polyester through aggregation. By incorporating a vinyl resin, the amount of the amorphous polyester resin with high melting and adhesive properties according to this embodiment can be adjusted, thereby adjusting the adhesion area ratio within an appropriate range. As a result, it is possible to achieve both improved adhesion between the toner image and the resin recording medium and reduced gloss unevenness. Meanwhile, the vinyl resin segment described below is chemically bonded to the amorphous polyester. In this embodiment, adjusting the amount of the vinyl resin segment allows the peak density (Spd) to be adjusted within an appropriate range. As a result, it is possible to further improve adhesion to the resin recording medium.

[0062] (1.1.1.1) Amorphous polyester The binder resin according to this embodiment contains an amorphous polyester. The term "amorphous polyester" refers to a condensation polymer of a polycarboxylic acid (a divalent or higher carboxylic acid) and a polyhydric alcohol (a divalent or higher alcohol), which exhibits amorphous properties. Amorphous polyester can be synthesized by polycondensing (esterifying) the polycarboxylic acid monomer and the polyhydric alcohol monomer using a known esterification catalyst.

[0063] A polycarboxylic acid is a compound containing two or more carboxy groups in one molecule. Examples of polycarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, mesaconic acid, dimethyl isophthalate, fumaric acid, dodecenylsuccinic acid, 1,10-dodecanedicarboxylic acid, etc. Among these, dimethyl isophthalate, terephthalic acid, dodecenylsuccinic acid, and trimellitic acid are preferred. These may be contained alone or in combination of two or more.

[0064] A polyhydric alcohol is a compound that contains two or more hydroxy groups in one molecule. In this embodiment, the polyhydric alcohol comprises an aliphatic polyhydric alcohol. Examples of aliphatic polyhydric alcohols include dihydric alcohols such as ethylene glycol, propylene glycol, butanediol, diethylene glycol, pentanediol, neopentyl glycol, hexanediol, heptanediol, cyclopentanediol, cyclohexanediol, octanediol, decanediol, and dodecanediol. Examples of aliphatic polyhydric alcohols include trihydric or higher polyols such as glycerin and pentaerythritol. Examples of aliphatic polyhydric alcohols include ester compounds and hydroxycarboxylic acid derivatives of these alcohols. These may be contained alone or in combination of two or more.

[0065] Among these, the aliphatic polyhydric alcohol is preferably an aliphatic polyhydric alcohol having 5 or more carbon atoms. Since an aliphatic polyhydric alcohol having 5 or more carbon atoms has high hydrophobicity, it increases the hydrophobic interaction with the hydrophobic portion of the resin contained in the recording medium, thereby improving the adhesion between the toner and the recording medium.

[0066] The polyhydric alcohol may include an aromatic polyhydric alcohol. Examples of aromatic polyhydric alcohols include bisphenols, alkylene oxide (ethylene oxide, propylene oxide, etc.) adducts of bisphenols, 1,3,5-benzenetriol, 1,2,4-benzenetriol, 1,3,5-trihydroxymethylbenzene, etc. Examples of aromatic polyhydric alcohols include derivatives of these. Examples of bisphenols include bisphenol A and bisphenol F.

[0067] In addition, in this embodiment, the "polyhydric alcohol" includes bisphenols because bisphenols can be esterified in the same manner as alcohols.

[0068] From the viewpoint of increasing the flexibility of the skeleton of the amorphous polyester, the proportion of aromatic polyhydric alcohol in the polyhydric alcohol is preferably low. Specifically, the content of aromatic polyhydric alcohol-derived structural units relative to the total number of moles of polyhydric alcohol-derived structural units is preferably 20 mol % or less.

[0069] Examples of esterification catalysts for amorphous polyesters include alkali metal compounds (sodium, lithium, etc.), alkaline earth metal compounds (magnesium, calcium, etc.), metal compounds (aluminum, zinc, manganese, antimony, titanium, tin, zirconium, germanium, etc.), phosphorous compounds, phosphoric acid compounds, and amine compounds.

[0070] The polymerization temperature for the amorphous polyester is not particularly limited, but is preferably within the range of, for example, 150 to 250° C. The polymerization time is also not particularly limited, but is preferably within the range of, for example, 0.5 to 10 hours. During the polymerization, the reaction system may be decompressed as necessary.

[0071] (hybrid amorphous polyester) The hybrid amorphous polyester in this embodiment is a resin in which an amorphous polyester segment and a vinyl resin segment other than the amorphous polyester are chemically bonded. The vinyl resin segment contains a structural unit derived from a vinyl monomer. By chemically bonding the amorphous polyester segment and the vinyl resin segment, the vinyl resin segment can be dispersed relatively uniformly in the amorphous polyester segment.

[0072] The hybrid amorphous polyester may be in any form, such as a block copolymer or a graft copolymer, so long as it contains an amorphous polyester segment and a vinyl resin segment.

[0073] The vinyl resin segment is not particularly limited as long as it is a polymerized vinyl monomer, and examples thereof include a styrene-acrylic resin segment, an acrylic acid resin segment, and an ethylene-vinyl acetate resin segment. Among these, a styrene-acrylic resin segment is preferred from the viewpoint of ease of control of viscoelasticity. By adjusting the viscoelasticity of the vinyl resin segment, the peak density (Spd) can be adjusted to an appropriate range, thereby improving adhesion to a resin recording medium.

[0074] The content of the structural units derived from styrene monomer in the vinyl resin segment is preferably within a range of 60 to 85% by mass relative to the total amount of the vinyl resin segment, which allows the vinyl resin segment to be imparted with a certain degree of elasticity and allows the peak density Spd to be adjusted within an appropriate range.

[0075] The styrene-acrylic resin segment is synthesized by addition polymerization of at least a styrene monomer and a (meth)acrylic acid ester monomer. The styrene monomer referred to here may include, in addition to styrene represented by the structural formula CH2=CH-C6H5, a compound having a known side chain or functional group in the styrene structure. Furthermore, the (meth)acrylic acid ester monomer referred to here may include, in addition to an acrylic acid ester compound and a methacrylic acid ester compound represented by the structural formula CH2=CHCOOR (R is an alkyl group), an ester compound having a known side chain or functional group in the structure of an acrylic acid ester derivative, a methacrylic acid ester derivative, or the like.

[0076] (ambireactive monomer) The bireactive monomer in this embodiment is a monomer having a substituent that reacts with both the vinyl resin segment and the amorphous polyester segment. Specifically, it is preferable to use a monomer that forms an ester bond with a hydroxyl group [-OH] derived from a polyhydric alcohol or a carboxyl group [-COOH] derived from a polycarboxylic acid contained in the amorphous polyester. Therefore, it is preferable that the vinyl resin segment contains a monomer that is addition polymerizable with the above-mentioned styrene monomer or (meth)acrylic acid ester monomer and has a carboxyl group [-COOH] or a hydroxyl group [-OH].

[0077] Examples of such monomers include monomers having a carboxyl group, such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, etc. Also included as monomers are monomers having a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, etc.

[0078] The presence of vinyl resin segments in the hybrid amorphous polyester can be confirmed by identifying the chemical structure using, for example, NMR measurement, methylation reaction P-GC / MS measurement, or the like.

[0079] In the present embodiment, the term "vinyl resin" refers to an amorphous polymer of a vinyl monomer. Specifically, the term "vinyl monomer" refers to a monomer having a vinyl group.

[0080] The vinyl resin is not particularly limited as long as it is a polymerized vinyl monomer, and examples thereof include styrene-acrylic resin, styrene resin, acrylic resin, and ethylene-vinyl acetate resin. These may be used alone or in combination of two or more. Among these, styrene-acrylic resin is preferred as the vinyl resin from the viewpoint of ease of control of viscoelasticity and chargeability. By including styrene-acrylic resin, it is possible to adjust the amount of hybrid amorphous polyester, which has excellent adhesiveness and low-temperature fixability, while ensuring fixation separation properties and chargeability, and to adjust the adhesion area ratio within an appropriate range. As a result, it is possible to achieve both improved adhesion between the toner image and the resin recording medium and reduced gloss unevenness. In the vinyl resin of this embodiment, the term "acrylic resin" also includes methacrylic resin.

[0081] The vinyl monomer is not particularly limited, and examples thereof include the following compounds. These may be used alone or in combination of two or more. Among them, the vinyl monomer preferably contains styrene and (meth)acrylic acid ester. The content of styrene and (meth)acrylic acid ester per 100 parts by mass of the vinyl monomer is more preferably 50 parts by mass or more.

[0082] (1) Styrenes In this embodiment, the term "styrenes" refers to compounds having a styrene structure. Examples of styrenes include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, etc. Derivatives of these styrenes are also included in the styrenes.

[0083] (2) (Meth)acrylic acid ester In this embodiment, the term "(meth)acrylic acid ester" refers to at least one of an acrylic acid ester and a methacrylic acid ester. Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isopropyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, phenyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, etc. Derivatives of these esters are also included in the (meth)acrylic acid esters.

[0084] (3) Vinyl esters Examples of vinyl esters include vinyl propionate, vinyl acetate, and vinyl benzoate. (4) Vinyl ethers Examples of vinyl ethers include vinyl methyl ether and vinyl ethyl ether. (5) Vinyl ketones Examples of vinyl ketones include vinyl methyl ketone, vinyl ethyl ketone, and vinyl hexyl ketone. (6) N-vinyl compounds Examples of N-vinyl compounds include N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone. (7) Other Other vinyl monomers include vinyl compounds (vinylnaphthalene, vinylpyridine, etc.), acrylic acid (acrylonitrile, methacrylonitrile, acrylamide, etc.), methacrylic acid derivatives, and the like.

[0085] The content of the vinyl resin segment is within a range of 3 to 30 parts by mass, and more preferably within a range of 10 to 20 parts by mass, relative to 100 parts by mass of the amorphous polyester segment.

[0086] The content of the hybrid amorphous polyester is in the range of 5 to 50 parts by mass relative to 100 parts by mass of the binder resin, and preferably 10 parts by mass or more and 40 parts by mass or less relative to 100 parts by mass of the toner base particles.

[0087] (1.1.1.2) Glass transition temperature From the viewpoint of achieving both sufficient low-temperature fixability and heat-resistant storage stability, the glass transition temperature (Tg) of the amorphous resin is preferably within a range of 30 to 70°C, and more preferably within a range of 40 to 65°C.

[0088] For example, differential scanning calorimetry (DSC) was performed using a differential scanning calorimeter (DSC7000X, manufactured by Hitachi) and a thermal analyzer controller (AS3 / DX, manufactured by Hitachi). Specifically, 5 mg of sample was placed in a sample container for the AL autosampler (φ6.8 mm, H2.5 mm, manufactured by Hitachi) and a cover for the AL autosampler (manufactured by Hitachi). This was then placed in the sample holder of the AS3 / DX, and the temperature was cycled in the following order: heating, cooling, and heating again. During the first and second heating cycles, the temperature was increased from 0°C to 150°C at a rate of 10°C / min and held at 150°C for 1 minute. During cooling, the temperature was decreased from 150°C to 0°C at a rate of 10°C / min and held at 0°C for 1 minute. A baseline shift was observed in the measurement curve obtained during the second heating cycle. The intersection of the extension of the baseline before the shift and the tangent line showing the maximum slope of the shifted portion of the baseline is taken as the glass transition temperature (Tg). An empty aluminum pan is used as a reference.

[0089] (1.1.1.3) Weight average molecular weight The weight average molecular weight (Mw) of the amorphous resin is preferably within a range of 10,000 to 100,000, more preferably 20,000 to 90,000, from the viewpoint of achieving both improved adhesiveness and suppression of uneven gloss. The weight average molecular weight of the amorphous resin can be measured in the same manner as the weight average molecular weight of the crystalline resin described below.

[0090] (1.1.2) Crystalline resin The toner base particles according to the present invention preferably contain a crystalline resin, which allows the crystalline portion of the crystalline resin to melt when the temperature exceeds the melting point, thereby enabling the crystalline resin and the amorphous resin to become compatible with each other, thereby improving low-temperature fixability and adhesiveness.

[0091] In the present invention, "exhibiting crystallinity" means that an endothermic curve obtained by DSC (differential scanning calorimetry) has a clear endothermic peak rather than a stepwise endothermic change at the melting point, i.e., during heating. A clear endothermic peak is a peak with a half-width of 15°C or less in an endothermic curve when heated at a heating rate of 10°C / min.

[0092] As the crystalline resin, it is preferable to use a known crystalline resin, such as a crystalline polyester or a crystalline polyurethane resin. In particular, from the viewpoint of sharp melting during melting and compatibility with the binder resin, a crystalline polyester is preferable. That is, it is preferable that the portion having a crystalline structure contains a crystalline polyester.

[0093] (1.1.2.1) Crystalline polyester The term "crystalline polyester" refers to a condensation polymer of a polycarboxylic acid (a divalent or higher carboxylic acid) and a polyhydric alcohol (a divalent or higher alcohol) that exhibits crystallinity.

[0094] A polycarboxylic acid is a compound containing two or more carboxy groups in one molecule. Examples of polycarboxylic acids include saturated aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, n-dodecylsuccinic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid (dodecanedioic acid), tetradecanedicarboxylic acid (tetradecanedioic acid), and tetradodecanedicarboxylic acid (tetradodecanedioic acid). Examples of polycarboxylic acids include alicyclic dicarboxylic acids (cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, etc.), trivalent or higher polycarboxylic acids (trimellitic acid, pyromellitic acid, etc.), and anhydrides of these carboxylic acid compounds. Other examples include alkyl esters having 1 to 3 carbon atoms. The crystalline polyester may contain one or more of these.

[0095] A polyhydric alcohol is a compound that contains two or more hydroxy groups in one molecule. Examples of polyhydric alcohols include aliphatic diols (1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, dodecanediol, neopentyl glycol, 1,4-butenediol, etc.), and trihydric or higher polyhydric alcohols (glycerin, pentaerythritol, trimethylolpropane, sorbitol, etc.). The crystalline polyester may contain one or more of these.

[0096] The method for synthesizing the crystalline polyester is not particularly limited, and it can be synthesized by polycondensing (esterifying) the polyhydric alcohol component and the polycarboxylic acid component using a known esterification catalyst.

[0097] The ratio of the polyhydric alcohol component to the polycarboxylic acid component is not particularly limited. For example, the equivalent ratio of the hydroxyl groups of the polyhydric alcohol component to the carboxyl groups of the polycarboxylic acid component is preferably within a range of 1.5 / 1 to 1 / 1.5, and more preferably within a range of 1.2 / 1 to 1 / 1.2.

[0098] Catalysts that can be used in the synthesis of crystalline polyesters include alkali metal compounds (sodium, lithium, etc.), alkaline earth metal compounds (magnesium, calcium, etc.), metal compounds (aluminum, zinc, manganese, antimony, titanium, tin, zirconium, germanium, etc.), phosphorous compounds, phosphoric acid compounds, and amine compounds.

[0099] Specific examples of tin compounds include dibutyltin oxide, tin octoate, tin dioctoate, and salts thereof. Examples of titanium compounds include titanium alkoxides (tetra-normal-butyl titanate, tetraisopropyl titanate, tetramethyl titanate, tetrastearyl titanate, etc.), titanium acylates (polyhydroxytitanium stearate, etc.), and titanium chelates (titanium tetraacetylacetonate, titanium lactate, titanium triethanolaminate, etc.).

[0100] Germanium compounds include germanium dioxide. Examples of aluminum compounds include oxides such as polyaluminum hydroxide, aluminum alkoxides, and tributylaluminate. These may be used alone or in combination of two or more. The polymerization temperature and polymerization time are not particularly limited, and the pressure in the reaction system may be reduced during the polymerization, if necessary.

[0101] As with amorphous polyesters, the crystalline polyester is preferably a hybrid crystalline polyester in which a crystalline polyester segment and a vinyl resin segment are chemically bonded, which provides the same effects as those of hybrid amorphous polyesters.

[0102] (1.1.2.2) Melting Point From the viewpoint of low-temperature fixability and hot offset resistance, the melting point (Tm) of the crystalline resin is preferably within a range of 55 to 90° C., and more preferably within a range of 60 to 85° C. The melting point of the crystalline resin can be controlled by the resin composition. When the crystalline resin is a crystalline polyester, the melting point of the crystalline polyester is preferably 75° C. or lower.

[0103] The melting point (Tm) is the temperature at the top of the endothermic peak, and can be measured by DSC (differential scanning calorimetry). For example, differential scanning calorimetry (DSC) was performed using a differential scanning calorimeter (DSC7000X, manufactured by Hitachi) and a thermal analyzer controller (AS3 / DX, manufactured by Hitachi). Specifically, 5 mg of sample was placed in a sample container for the AL autosampler (φ6.8 mm, H2.5 mm, manufactured by Hitachi) and a cover for the AL autosampler (manufactured by Hitachi). This was then placed in the sample holder of the AS3 / DX, and the temperature was cycled in the following order: heating, cooling, and heating again. During the first and second heating cycles, the temperature was increased from 0°C to 150°C at a rate of 10°C / min and held at 150°C for 1 minute. During cooling, the temperature was decreased from 150°C to 0°C at a rate of 10°C / min and held at 0°C for 1 minute. The melting point was determined as the temperature at the top of the endothermic peak in the endothermic curve obtained during the second heating cycle.

[0104] (1.1.2.3) Weight average molecular weight The weight average molecular weight of the crystalline resin is not particularly limited, but is preferably within the range of 1,000 to 50,000, more preferably within the range of 5,000 to 30,000, from the viewpoint of achieving both improved adhesiveness and suppression of uneven gloss.

[0105] The weight average molecular weight of the crystalline resin can be measured by the following method. For example, a gel permeation chromatography system "HLC-8320GPC" (manufactured by Tosoh Corporation) is used, which is connected to one column "TSKgel guard column SuperHZ-L" and three columns "TSKgel SuperHZM-M" (all manufactured by Tosoh Corporation).

[0106] The column (TSK-) was stabilized at 40°C, and tetrahydrofuran (THF) was applied as a carrier solvent at a flow rate of 0.35 mL / min. A THF sample solution containing the resin sample, adjusted to a sample concentration of 1 mg / mL, was processed for 10 minutes at room temperature using a roll mill. The solution was filtered through a membrane filter with a pore size of 0.2 μm to obtain a sample solution. 10 μL of this sample solution was injected into the instrument along with the carrier solvent and detected using a refractive index detector (RI detector).

[0107] A calibration curve is created using a polystyrene standard sample with a monodisperse molecular weight distribution. The molecular weight distribution of the measurement sample is calculated based on this calibration curve. The calibration curve is created using "polystylene standard sample TSK standard" manufactured by Tosoh Corporation: "A-500" and "F-1 The data are collected at 300 ms intervals during sample analysis.

[0108] Alternatively, as described below, the crystalline resin and the release agent in the toner may be separated, and then the weight average molecular weight of the crystalline resin may be calculated by the above-mentioned measurement method.

[0109] (Separation of crystalline resin) An example in which the crystalline resin is a crystalline polyester will be described. First, the toner is dispersed in ethanol, which is a poor solvent for the toner, and the resulting dispersion is heated to a temperature exceeding the melting points of the crystalline polyester and the release agent. Pressure may be applied if necessary. At this point, the crystalline polyester and the release agent, which have exceeded their melting points, are melted in the ethanol. Then, a mixture of the crystalline polyester and the release agent can be extracted from the toner by solid-liquid separation. The mixture can be separated by molecular weight to separate the crystalline polyester and the release agent from the toner.

[0110] (Acid value of crystalline resin) From the viewpoint of low temperature fixability and fold fixability, the acid value of the crystalline resin is preferably within a range of 9 to 30 mgKOH / g, and more preferably within a range of 15 to 23 mgKOH / g.

[0111] The acid value of a crystalline polyester is expressed as the number of milligrams of potassium hydroxide required to neutralize the carboxyl groups present in 1 g of the resin (mgKOH / g). Specifically, it is determined by the following method in accordance with JIS K0070-1992.

[0112] (1) Preparation of reagents (a) Phenolphthalein solution 1.0 g of phenolphthalein is dissolved in 90 mL of ethyl alcohol (95% by volume), and ion-exchanged water is added to make the total volume 100 mL to obtain a phenolphthalein solution.

[0113] (b) Potassium hydroxide solution Dissolve 7 g of special-grade potassium hydroxide in 5 mL of ion-exchanged water and add ethyl alcohol (95% by volume) to make 1 L. Place this solution in an alkali-resistant container to avoid contact with carbon dioxide, etc., and leave it for 3 days. Then filter to obtain potassium hydroxide solution. Store the resulting potassium hydroxide solution in an alkali-resistant container.

[0114] (c) Factor of potassium hydroxide solution Place 25 mL of 0.1 mol / L hydrochloric acid in an Erlenmeyer flask and add a few drops of the phenolphthalein solution. Then, titrate this with potassium hydroxide solution. Calculate the potassium hydroxide factor from the amount of potassium hydroxide solution required for neutralization.

[0115] (d) Hydrochloric acid solution 0.1 mol / L hydrochloric acid prepared in accordance with JIS K8001-1998 is used.

[0116] (2) Operation (a) Main test Accurately weigh 2.0 g of toner into a 200 mL Erlenmeyer flask, add 100 mL of a toluene:ethanol (2:1) mixed solution to the Erlenmeyer flask, and dissolve for 5 hours. Next, add a few drops of phenolphthalein solution to the Erlenmeyer flask as an indicator, and titrate with potassium hydroxide solution. The titration endpoint is when the indicator's light red color lasts for approximately 30 seconds.

[0117] (b) Blank test The titration is carried out in the same manner as in the main test above, except that no sample is used, i.e., only a mixture of toluene:ethanol (2:1) is used.

[0118] (3) Substitute the obtained results into the following formula to calculate the acid value. A=[(CD)×f×5.611] / S Here, the symbols and numbers are as follows: A: Acid value (mgKOH / g) C: Amount of potassium hydroxide solution added in this test (mL) D: Amount of potassium hydroxide solution added for blank test (mL) f: Factor of 0.1 mol / L potassium hydroxide ethanol solution 5.611: Molar mass of potassium hydroxide 56.11 (g / mol) × (1 / 10) S: mass of sample (g)

[0119] (1.2) Release agent The release agent is not particularly limited, and various known release agents can be used. For example, polyolefin wax (polyethylene wax, polypropylene wax, etc.), branched chain hydrocarbon wax (microcrystalline wax, etc.), long chain hydrocarbon wax (paraffin wax, Sasol wax, etc.), synthetic wax (Fischer-Tropsch wax, etc.), dialkyl ketone wax (distearyl ketone, etc.), ester wax (carnauba wax, montan wax, behenyl behenate, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecanediol distearate, tristearyl trimellitate, distearyl maleate, etc.), amide wax (ethylenediamine behenylamide, tristearyl trimellitate amide, etc.), etc. can be used.

[0120] The melting point of the release agent is preferably within the range of 60 to 100°C. A melting point of 60°C or higher can prevent the release agent from volatilizing and breaking down into fine particles during toner fixing, thereby reducing the environmental impact. Furthermore, a melting point of 100°C or lower allows the release agent to melt during toner fixing, resulting in good separation performance from the fixing member.

[0121] The content of the release agent is preferably in the range of 1 to 30 parts by mass, more preferably in the range of 3 to 20 parts by mass, and even more preferably in the range of 5 to 15 parts by mass, relative to 100 parts by mass of the binder resin. By having the content of the release agent in the above range, sufficient fixing separation properties can be obtained.

[0122] (1.3) Colorants The colorant is not particularly limited, and various known dyes and pigments can be used. Examples of colorants for obtaining black toner include carbon black (furnace black, channel black, etc.), magnetic materials (magnetite, ferrite, etc.), dyes, and inorganic pigments including non-magnetic iron oxide.

[0123] Colorants for obtaining color toners include known dyes and organic pigments. Examples of organic pigments include CI Pigment Red 5, 48:1, 53:1, 57:1, 81:4, 122, 139, 144, 149, 166, 177, 178, 222, 238, and 269. Examples of organic pigments include CI Pigment Yellow 14, 17, 74, 93, 94, 138, 155, 180, and 185. CI Pigment Orange 31 and 43, and CI Pigment Blue 15:3, 60, and 76.

[0124] Examples of dyes include CI Solvent Red 1, 49, 52, 58, 68, 11, and 122. Examples of dyes include CI Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, and 162, and CI Solvent Blue 25, 36, 69, 70, 93, and 95.

[0125] The colorant for obtaining the toner of each color may be contained either alone or in combination of two or more. The content of the colorant is preferably in the range of 1 to 10 parts by mass, and more preferably in the range of 2 to 8 parts by mass, relative to 100 parts by mass of the binder resin.

[0126] (1.4) Charge control agent The charge control agent may be any of various known compounds. The content of the charge control agent is preferably within the range of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the binder resin.

[0127] (2) External additives The toner of this exemplary embodiment may further contain an external additive added to the toner base particles, which can further improve the fluidity, chargeability, cleaning properties, and the like of the toner.

[0128] Examples of external additives include inorganic oxide fine particles (silica, alumina, titanium oxide, etc.), inorganic stearic acid compound fine particles (aluminum stearate, zinc stearate, etc.), inorganic titanic acid compound fine particles (strontium titanate, zinc titanate, etc.), etc. These may be used alone or in combination of two or more.

[0129] From the viewpoint of heat-resistant storage property and environmental stability, it is preferable to subject these inorganic fine particles to a hydrophobic treatment using a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil or the like.

[0130] The total amount of external additives added is preferably within a range of 0.05 to 5 parts by mass, and more preferably within a range of 0.1 to 3 parts by mass, relative to 100 parts by mass of toner.

[0131] 2. Physical properties of toner for developing electrostatic images (1) Density of mountain peaks on the surface of the image In the present invention, the reason why the peak density Spd is defined as the surface roughness of the image surface is as follows. Surface roughness can be broadly divided into two categories: "line roughness" and "area roughness." While "line roughness" is obtained using the contour curve method as two-dimensional information, "area roughness" is obtained using the three-dimensional method as three-dimensional information, providing a wealth of information. The measuring equipment, filter processing used, measurement conditions, etc. must be changed depending on the roughness information you wish to obtain.

[0132] The surface of a toner image is made up of numerous irregularities. In order to control the state of these irregularities, it is considered preferable to use "area roughness," which is made up of three-dimensional information with a richer amount of information, rather than "line roughness," which is prone to variations in results depending on the measurement location and the scanning direction.

[0133] "Surface roughness" has several main parameters. Specifically, these include height parameters, spatial parameters, composite parameters, functional parameters, and morphological parameters. Among these, it has been found that "peak density (Spd)," which is classified as a morphological parameter, is closely related to "adhesion," the subject of this invention. This is thought to be because peak density is a roughness parameter that can represent the contact state when another object comes into contact with the image surface. "Peak density (Spd)" is a parameter that represents the number of peaks per unit area, measured in accordance with ISO 25178.

[0134] To calculate the peak density, only peaks on the image surface that are greater than 5% of the maximum amplitude of the contour curve are counted. The number of peaks obtained is then divided by the projected area of ​​the contour curve. The peak density can be measured using a non-contact surface roughness measuring device. In this invention, the value is measured using a 10x magnification lens.

[0135] The peak density can be measured, for example, by the following procedure. Adhesion amount 4g / m on resin recording medium 2 A solid image as described above is formed. The resin recording medium on which the image has been formed is placed with the image side facing up on the stage of a laser microscope "VKX-250" (manufactured by Keyence Corporation). The surface of the image is focused using a 10x lens, and the original surface is measured.

[0136] Set the filters (filter type: Gaussian, S filter: none, F operation: none, L filter: none, edge hardening correction: ON) and specify the evaluation area (714 μm * 535 μm). Next, perform surface shape correction (waviness removal). Next, set the threshold so that less than 5% of the lower limit of the maximum amplitude (maximum peak height) of the contour curved surface is cut off. Note that whether or not the setting is set to count only peaks greater than 5% of the maximum amplitude (maximum peak height) of the contour curved surface differs depending on the type of laser microscope. Therefore, if the laser microscope is already set as described above, there is no need to set a threshold.

[0137] The peak density is 5000-100000 mm -2 It is preferable that the range is 20,000 to 90,000 mm. -2 It is more preferable that the range is 30,000 to 80,000 mm. -2 Within the above range, both tape peeling durability and scratch resistance can be achieved, and excellent adhesiveness can be obtained.

[0138] Factors that cause a toner image to peel off from a recording medium include peeling caused by adhesive materials (highly adhesive, flexible materials such as stickers and tapes) and external forces such as scratches on the image with sharp objects (needles, fingernails, etc.). The smoother the surface of the image, the greater the contact area between the adhesive material and the surface of the image, which increases the adhesion between the adhesive material and the image, making the image more likely to peel off from the recording medium. -2 By satisfying the above, the smoothness of the image surface is not increased too much, which makes it easier for the peaks of the mountains on the surface of the image to come into contact with the adhesive material than other areas, thereby reducing the adhesion between the adhesive material and the image and making the image less likely to peel off from the recording medium.

[0139] In addition, the peak density of the mountains is 100,000 mm -2 By ensuring that the surface of the image is not too uneven, it is possible to reduce the frictional force even if the surface of the image is scratched, making it difficult for the image to peel off from the recording medium.

[0140] (2) Adhesion area ratio between the image and the resin recording medium The "adhesion area ratio" refers to the ratio of the total area of ​​the region where the image and the resin recording medium are adhered to each other without any air entering at the interface between them to the area of ​​the image formed on the resin recording medium. The components of the image that are adhered to the resin recording medium are not limited. For example, external additives, waxes, pigments, etc. contained in the toner that are adhered to the resin recording medium are also included in the adhesion region. The area of ​​the adhesion region can be observed, for example, using a device with the function of an optical microscope.

[0141] Under an optical microscope, the bonded areas appear opaque, while the non-bonded areas appear transparent, just like the resin recording medium. An optical microscope is an optical instrument that uses an eyepiece to further magnify the real image of a minute object magnified by an objective lens.

[0142] The adhesion area ratio can be measured, for example, by the following procedure. Adhesion amount 4g / m on resin recording medium 2 The above solid image is formed. The resin recording medium is fixed on the stage of a laser microscope "VKX-250" (manufactured by Keyence Corporation) with the resin recording medium facing up and the image surface facing down, and the image is smooth. A 10x lens is used to focus on the interface between the resin recording medium and the image. The focus and light intensity are adjusted so that the bonded and non-bonded areas can be clearly distinguished, and an observation photograph is taken in optical microscope mode (HDR photography). Note that the "non-bonded area" here refers to an area within the solid image where the image and the resin recording medium are not bonded. A total of 10 observation photographs are taken with different observation fields. A threshold is determined for each obtained observation photograph using Otsu's binarization model, and a binarization process is performed to separate the bonded and non-bonded areas. The bonded area ratio is calculated for each observation photograph, and the average value is used as the bonded area ratio in this embodiment.

[0143] The adhesion area ratio can be calculated using the following formula. (Formula) Adhesion area ratio [%] = area of ​​adhesive region / (area of ​​adhesive region + area of ​​non-adhesive region) x 100

[0144] The adhesion area ratio is preferably in the range of 60 to 95%, more preferably in the range of 70 to 91%, and even more preferably in the range of 80 to 87%.

[0145] With an adhesion area ratio of 60% or more, the image is less likely to peel off from the recording medium. With an adhesion area ratio of 95% or less, small air explosions within the toner layer and uneven gloss caused by the formation of an image containing an air layer are less likely to occur.

[0146] (3) Toner particle size The average particle size of the toner particles is, for example, preferably in the range of 3 to 10 μm, more preferably in the range of 4 to 8 μm, in terms of the volume-based median diameter (d50). The average particle size of the toner particles can be controlled by the concentration of the aggregating agent used in the production of the toner base particles, the amount of organic solvent added, the fusion time, the composition of the binder resin, and the like. By ensuring that the volume-based median diameter (d50) is within the above range, extremely fine dot images at the 1200 dpi level can be faithfully reproduced.

[0147] The volume-based median diameter (d50) of toner particles is measured and calculated using a measuring device that is a "Multisizer 3" (manufactured by Beckman Coulter) connected to a computer system equipped with data processing software "Software V3.51."

[0148] Specifically, first, a toner sample to be measured is added to a surfactant solution, followed by dilution with pure water, followed by ultrasonic dispersion to prepare a toner particle dispersion. For the surfactant solution, an anionic surfactant such as sodium polyoxyethylene lauryl ether sulfate is preferably used for the purpose of dispersing the toner particles.

[0149] This toner particle dispersion is pipetted into a beaker containing "ISOTON II" (manufactured by Beckman Coulter) in the sample stand until the concentration displayed on the measuring device reaches 6-8%. By setting this concentration, highly reproducible measurement values ​​can be obtained.

[0150] The measurement device is then set to a particle count of 25,000 and an aperture diameter of 100 μm. The toner particle size measurement range of 2 to 60 μm is divided into 256 parts, and the frequency value of the toner particle size is calculated. The particle size of the largest 50% of the volume cumulative fraction is taken as the volume-based median diameter (d50).

[0151] (4) Average circularity of toner particles From the viewpoint of the stability of charging characteristics and low-temperature fixability, the average circularity of the toner particles is preferably within a range of 0.930 to 1.000, and more preferably within a range of 0.950 to 0.995.

[0152] When the average circularity is within the above range, both the transferability and cleaning performance of the toner can be achieved, and the chargeability of the toner is stable, allowing high-quality images to be formed.

[0153] The average circularity of the toner particles can be measured using, for example, a flow type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation).

[0154] Specifically, the toner sample to be measured is added to a surfactant solution, allowed to settle, diluted with pure water, and then ultrasonically dispersed to prepare a toner particle dispersion. For the surfactant solution, an anionic surfactant such as sodium polyoxyethylene lauryl ether sulfate is preferably used to disperse the toner particles. Then, using a flow particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation), for example, images are taken in the HPF (high magnification imaging) mode under measurement conditions at an appropriate concentration of 3,000 to 10,000 HPF detection counts.

[0155] The circularity of each toner particle is calculated according to the following formula: The circularity of each toner particle is then added together and divided by the total number of toner particles to calculate the average circularity. High reproducibility can be achieved if the HPF detection number is within the above range. Formula: Circularity = (perimeter of a circle with the same projected area as the particle image) / (perimeter of the particle's projected image)

[0156] (5) Glass transition temperature of toner From the viewpoint of achieving both sufficient low-temperature fixability and heat-resistant storage stability, the glass transition temperature (Tg) of the toner is preferably within a range of 15 to 40° C., and more preferably within a range of 20 to 35° C. The glass transition temperature can be measured by the method described above.

[0157] 3. Structure of toner for developing electrostatic images (core-shell structure) The toner base particles may have a multi-layer structure, such as a core-shell structure comprising a core particle and a shell layer covering the surface of the core particle.

[0158] The shell layer does not need to cover the entire surface of the core particle, and the core particle may be partially exposed. The cross section of the core-shell structure can be confirmed by known observation means, for example, a transmission electron microscope (TEM) or a scanning probe microscope (SPM).

[0159] When the toner base particles have a core-shell structure, the core particles and the shell layer can be differentiated in properties such as glass transition temperature, melting point, and hardness depending on the purpose. For example, core particles containing a binder resin, a colorant, a release agent, etc. and having a relatively low glass transition temperature (Tg) are prepared. Then, a resin with a relatively high glass transition temperature (Tg) is aggregated and fused to the core particles to form a shell layer. The shell layer preferably contains an amorphous resin. This configuration allows for both low-temperature fixability and heat-resistant storage stability. Furthermore, good charge retention performance is obtained.

[0160] Furthermore, by using a core-shell structure for the toner base particles and by using a specific amorphous resin in the shell layer, it is easy to adjust the adhesion area ratio and peak density (Spd) within appropriate ranges. As a result, it is possible to achieve both improved adhesion to resin recording media and reduced gloss unevenness. Furthermore, by using a styrene-acrylic resin in the core particles, this effect can be further enhanced.

[0161] 4. Manufacturing method of toner for developing electrostatic images The method for producing the toner is not particularly limited. Examples of the production method include suspension polymerization, emulsion aggregation, and other known methods. Among these, the emulsion aggregation method is preferable. By using the emulsion aggregation method, it is possible to produce toner at low cost and with stable quality. Furthermore, it is possible to easily produce toner particles with small particle diameters.

[0162] In the emulsion aggregation method, first, an aqueous dispersion of hybrid amorphous polyester fine particles is mixed with an aqueous dispersion of fine particles of a release agent, a colorant, an amorphous resin other than the hybrid amorphous polyester, a crystalline resin, etc., as needed, and then these fine particles are aggregated to form wet toner base particles.

[0163] Here, "aqueous dispersion" refers to a dispersion (particles) dispersed in an aqueous medium. Also, an aqueous medium refers to a medium in which the main component, i.e., a component that accounts for 50% by mass or more, is water.

[0164] Components other than water contained in the aqueous medium include water-soluble organic solvents. Examples of water-soluble organic solvents include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Among these, alcohol-based organic solvents such as methanol, ethanol, isopropanol, and butanol are preferred from the viewpoint of not dissolving the resin.

[0165] An example of the toner manufacturing method is shown below, but the present invention is not limited to this. Note that the "amorphous resin" here refers to an amorphous resin other than the hybrid amorphous polyester. If an amorphous resin other than the hybrid amorphous polyester is not used, the following step (2) is not necessary.

[0166] (1) A step of synthesizing a hybrid amorphous polyester and preparing a dispersion of hybrid amorphous polyester microparticles (2) A step of synthesizing an amorphous resin other than the hybrid amorphous polyester and preparing a dispersion of amorphous resin particles. (3) A step of synthesizing a hybrid crystalline polyester and preparing a dispersion of hybrid crystalline polyester microparticles. (4) A step of preparing a dispersion of release agent particles (5) A step of preparing a dispersion of colorant particles (6) A step of aggregating the hybrid amorphous polyester particles, amorphous resin particles, hybrid crystalline polyester particles, release agent particles, and colorant particles to form core particles of toner base particles. (7) A process of aggregating hybrid amorphous polyester fine particles onto the surface of the core particles of the toner base particles to form a shell layer of the toner base particles. (8) A process of fusing and maturing the toner base particles using thermal energy to control the shape. (9) Step of cooling the dispersion of toner base particles (10) A process of filtering the toner base particles from the aqueous medium, washing the toner base particles to remove surfactants, etc., and obtaining wet toner base particles. (11) Step of drying the wet toner base particles (12) Step of adding external additives to the dried toner base particles

[0167] (1) A step of synthesizing a hybrid amorphous polyester and preparing a dispersion of hybrid amorphous polyester microparticles In this step, the hybrid amorphous polyester is synthesized by a conventionally known method, and the hybrid amorphous polyester is dispersed in the form of fine particles in an aqueous medium to prepare a dispersion of hybrid amorphous polyester fine particles.

[0168] The amorphous polyester segment and the vinyl resin segment that constitute the hybrid amorphous polyester may be synthesized first, or they may be synthesized simultaneously. The synthesized hybrid amorphous polyester is then dissolved or dispersed in an organic solvent to prepare an oil phase. The oil phase is then dispersed in an aqueous medium by phase inversion emulsification or the like to form oil droplets with a desired particle size. The organic solvent is then removed to prepare an aqueous dispersion of amorphous polyester microparticles.

[0169] The amount of the aqueous medium used is preferably within a range of 50 to 2000% by mass, more preferably within a range of 100 to 1000% by mass, based on the total mass of the oil phase liquid. From the viewpoint of dispersion stability of the oil droplets, a surfactant or the like may be added to the aqueous medium. Examples of the surfactant include various conventionally known anionic surfactants, cationic surfactants, nonionic surfactants, etc.

[0170] From the viewpoint of removal treatment after the formation of oil droplets, the organic solvent used for preparing the oil phase liquid is preferably one having a low boiling point and low solubility in water, such as methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, and xylene. These may be used alone or in combination of two or more.

[0171] The amount of the organic solvent used is preferably within a range of 1 to 300% by mass based on the total mass of the hybrid amorphous polyester. The emulsification and dispersion of the oil phase liquid can be carried out by utilizing mechanical energy.

[0172] The toner base particles may contain internal additives such as a release agent, a charge control agent, etc. Such internal additives may be incorporated into the toner base particles by, for example, dissolving or dispersing them in advance in a monomer solution for synthesizing the hybrid amorphous polyester.

[0173] The average particle size of the hybrid amorphous polyester microparticles is preferably in the range of 100 to 400 nm in terms of volume-based median diameter (d50). The volume-based median diameter (d50) can be measured using, for example, a "Microtrac UPA-150" (manufactured by Nikkiso Co., Ltd.).

[0174] (2) A step of synthesizing an amorphous resin other than the hybrid amorphous polyester and preparing a dispersion of amorphous resin particles. In this step, an amorphous resin is synthesized by a conventionally known method, and the amorphous resin is dispersed in the form of fine particles in an aqueous medium to prepare a dispersion of amorphous resin fine particles.

[0175] The dispersion of amorphous resin particles can be prepared by the same procedure as that for the dispersion of hybrid amorphous polyester particles.

[0176] (3) A step of synthesizing a hybrid crystalline polyester and preparing a dispersion of hybrid crystalline polyester microparticles. The dispersion of hybrid crystalline polyester particles can be prepared by the same procedure as that for the dispersion of hybrid amorphous polyester particles, and it is preferable to adjust the temperature during dispersion as necessary.

[0177] (4) A step of preparing a dispersion of release agent particles This step is carried out as necessary when a release agent is contained in the toner base particles. The dispersion of the release agent particles can be prepared by dispersing the release agent in an aqueous medium to which a surfactant has been added at a critical micelle concentration (CMC) or higher.

[0178] The release agent can be dispersed by utilizing mechanical energy. The dispersing machine is not particularly limited, and examples thereof include an ultrasonic dispersing machine, a mechanical homogenizer, a pressure dispersing machine (such as a Manton-Gaulin or pressure homogenizer), and a medium-type dispersing machine (such as a sand grinder or a diamond fine mill).

[0179] The release agent fine particles preferably have a volume-based median diameter (d50) in the dispersed state within a range of 10 to 300 nm, more preferably within a range of 100 to 200 nm, and particularly preferably within a range of 100 to 150 nm. The volume-based median diameter (d50) of the release agent fine particles can be measured, for example, using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).

[0180] (5) A step of preparing a dispersion of colorant particles The dispersion of colorant particles can be prepared by the same procedure as that for the dispersion of release agent particles. The release agent particles are preferably dispersed by heating to a temperature equal to or higher than the melting point, but the colorant particles do not necessarily need to be heated.

[0181] (6) A step of aggregating the hybrid amorphous polyester particles, amorphous resin particles, hybrid crystalline polyester particles, release agent particles, and colorant particles to form core particles of toner base particles. In this step, a coagulant is added to the dispersion liquid in which the above-mentioned fine particles have been dispersed at a concentration equal to or greater than the critical coagulation concentration. The temperature of the reaction liquid is adjusted to cause the fine particles to coagulate, thereby forming toner base particles.

[0182] The flocculant is not particularly limited, and is preferably, for example, a metal salt such as an alkali metal salt, an alkaline earth metal salt, etc. Examples of the metal salt include monovalent metal salts (sodium, potassium, lithium, etc.), divalent metal salts (calcium, magnesium, manganese, copper, etc.), and trivalent metal salts (iron, aluminum, etc.).

[0183] Specific examples of metal salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, aluminum chloride, aluminum sulfate, polyaluminum chloride, polyaluminum hydroxide, etc. Among these, trivalent metal salts are preferred from the viewpoint of promoting aggregation with smaller amounts. These may be used alone or in combination of two or more.

[0184] (7) A process of aggregating amorphous polyester fine particles onto the surface of the core particles of the toner base particles to form a shell layer of the toner base particles. In this process, a dispersion of amorphous polyester is added to a dispersion of core particles of toner base particles. By adjusting the pH, temperature, etc. of the reaction solution, the amorphous polyester fine particles are aggregated on the surface of the core particles, forming a shell layer of the toner base particles.

[0185] (8) A process of fusing and maturing the toner base particles using thermal energy to control the shape. This step is carried out as necessary when the toner base particles are aged by thermal energy to control their shape. Specifically, in the aging treatment, the dispersion of the toner base particles is heated and stirred by adjusting the heating temperature, stirring speed, heating time, etc. so that the circularity of the toner base particles reaches a desired value.

[0186] (9) Step of cooling the dispersion of toner base particles In this step, the dispersion of toner base particles is cooled. The cooling rate is preferably within a range of 5 to 20°C / min, and more preferably within a range of 10 to 20°C / min. The specific cooling method is not particularly limited. Examples include a method of cooling by introducing a refrigerant from the outside of the reaction vessel, a method of cooling by directly adding cold water to the reaction system, and a method of cooling using a heat exchanger.

[0187] (10) A process of filtering the toner base particles from the aqueous medium, washing the toner base particles to remove surfactants, etc., and obtaining wet toner base particles. In this process, the toner base particles are separated from the cooled dispersion liquid of the toner base particles by solid-liquid separation. The resulting toner cake is then washed to remove any adhering substances such as surfactants and aggregating agents, thereby obtaining wet toner base particles. Note that the term "toner cake" used here refers to a cake-like aggregate of toner base particles in a wet state.

[0188] The method of solid-liquid separation is not particularly limited, and examples thereof include centrifugation, vacuum filtration using a Nutsche filter or the like, and filtration using a filter press or the like. In addition, in washing, it is preferable to wash with water until the electrical conductivity of the filtrate becomes 10 μS / cm or less.

[0189] (11) Step of drying the wet toner base particles In this step, the wet toner base particles that have been washed and, in some cases, further treated to remove the solvent are dried.

[0190] (12) Step of adding external additives to the dried toner base particles This step is carried out as necessary when an external additive is added to the toner base particles. The toner base particles can be used as they are as toner. Furthermore, from the viewpoints of fluidity, chargeability, cleaning properties, etc., external additives such as so-called fluidizing agents and cleaning aids may be added to the toner base particles. Examples of the mixing device for the external additive include mechanical mixers such as a Henschel mixer and a coffee mill.

[0191] 5. Developer The toner can be used as a magnetic or non-magnetic one-component developer, or may be mixed with a carrier to form a two-component developer.

[0192] When the toner is used as a two-component developer, the carrier can be magnetic particles made of a conventionally known material. Examples of materials for the magnetic particles include metals (iron, ferrite, magnetite, etc.), alloys of metals with aluminum, and alloys of other metals (lead, etc.). Among these, ferrite particles are preferred.

[0193] The carrier may be a coated carrier in which the surfaces of magnetic particles are coated with a coating agent such as resin, or a dispersion type carrier in which magnetic powder is dispersed in a binder resin.

[0194] The volume-based median diameter (d50) of the carrier is preferably within a range of 20 to 100 μm, and more preferably within a range of 25 to 80 μm. The volume-based median diameter (d50) of the carrier can be measured, for example, using a laser diffraction particle size distribution analyzer "HELOS" (manufactured by SYMPATEC) equipped with a wet disperser.

[0195] The mixing device used to mix the toner and carrier is not particularly limited, and examples thereof include a Nauta mixer, a W-cone mixer, and a V-type mixer.

[0196] The toner content in the developer is preferably within a range of 5.0 to 8.0 parts by mass with respect to 100 parts by mass of the developer.

[0197] 6.Image forming method The image forming method of this embodiment is an electrophotographic image forming method including a step of fixing an electrostatic image developing toner on a resin recording medium to form an image. 2 When the above solid image is created, the density of the peaks on the surface of the solid image is 5000 to 100,000 mm -2 The adhesive area ratio at the interface between the resin recording medium and the solid image is within the range of 60 to 95%.

[0198] The image forming method of this embodiment is an electrophotographic image forming method including a step of fixing toner for developing an electrostatic image on a resin recording medium to form an image. 2 When a solid image is created, the density of the peaks on the surface of the solid image is 5000 to 100,000 mm -2 and the adhesion area ratio at the interface between the polyethylene terephthalate film and the solid image is within the range of 60 to 95%.

[0199] The developer to be used is not particularly limited, and the above-mentioned developers may be used. The developer may be a magnetic or non-magnetic one-component developer, or a two-component developer. An example of an image forming method using a two-component developer will be described below, but the present invention is not limited to this.

[0200] The electrophotographic method preferably includes a charging step of charging the surface of an image carrier, an electrostatic image forming step of forming an electrostatic image on the charged surface of the image carrier, a developing step of developing the electrostatic image formed on the surface of the image carrier as a toner image using the developer, a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, a fixing step of fixing the toner image transferred to the surface of the recording medium, and a cleaning step of the surface of the image carrier.

[0201] (mountain peak density) In the image forming method of this embodiment, the density of the peaks on the surface of the image is 5000 to 100000 mm -2 The peak density on the surface of the toner image can be controlled by adjusting the toner composition as described above. It is also thought that it can be controlled by the fixing temperature, fixing pressure, conveyance speed of the resin recording medium, type of fixing belt, etc.

[0202] (adhesion area ratio) The image forming method of this embodiment is characterized in that the adhesion area ratio at the interface between the resin recording medium and the image is within the range of 60 to 95%. The adhesion area ratio at the interface between the resin recording medium and the toner image can be controlled by adjusting the toner composition as described above. It is also thought that it can be controlled by the type, thickness, fixing temperature, fixing pressure, and conveyance speed of the resin recording medium.

[0203] (Resin recording medium) In this embodiment, a "resin recording medium" refers to a recording medium that is transparent and flexible and contains a resin. The resin content is preferably 60% by mass or more, and more preferably 80% by mass or more. The type of resin is not limited. Examples of resins include polypropylene (PP), polyethylene terephthalate (PET), triacetyl cellulose (TAC), polystyrene (PS), polyethylene (PE), nylon (NY), polylactic acid (PLA), etc. The resin recording medium may be a single layer, or a multi-layer in which two or more resin recording layers are united via a transparent adhesive layer.

[0204] The resin recording medium is preferably a continuous-filament medium from the viewpoints of transportability, handling, and productivity improvement. Furthermore, continuous-filament medium is typically stored in a roll and is pulled out from the roll when an image is formed. Therefore, when the continuous-filament medium is pulled out from the roll and an image is formed, the continuous-filament medium may be slightly stretched, which may cause stress. If an image is formed in a stressed state, the image may easily peel off from the continuous-filament medium when the stress is subsequently removed from the continuous-filament medium. However, the toner of this embodiment has high adhesion between the toner image and the continuous-filament medium, and the adhesion area ratio between the toner image and the continuous-filament medium is not too high, leaving a moderate gap. Therefore, when the stress generated in the continuous-filament medium is released, it is believed that the toner image is less susceptible to the influence of residual stress due to the gap.

[0205] When the resin recording medium is a continuous medium, it is preferable that the resin recording medium is wound up in a roll and stored after image formation. By storing the resin recording medium in a roll, efficient mass production can be achieved.

[0206] The thickness of the resin recording medium is preferably 75 μm or less. When the resin recording medium is relatively thin, it is more susceptible to the effects of heat and pressure, making it easier to obtain a desired adhesion area ratio at a lower temperature. On the other hand, when the resin recording medium is relatively thick, poor fixation separation and the occurrence of wrinkles can be suppressed. From this perspective, the thickness is more preferably within the range of 20 to 70 μm, and even more preferably within the range of 30 to 55 μm.

[0207] The resin recording medium does not need to be surface-treated, but it is preferable that it be surface-treated. Surface treatment can improve adhesion. Examples of surface treatment methods include corona treatment and plasma treatment.

[0208] 7. Image Formation System The image forming system of this embodiment is an electrophotographic image forming system that forms an image by fixing toner for developing an electrostatic image on a resin recording medium. 2 When creating a solid image, the density of the peaks on the surface of the solid image is set to 5000 to 100,000 mm -2 and a means for setting the adhesion area ratio at the interface between the solid image and the polyethylene terephthalate film to within a range of 60 to 95%.

[0209] The image forming system of this embodiment includes an electrophotographic image forming apparatus and toner for developing electrostatic images. The image forming apparatus described below can adjust the fixing temperature, fixing pressure, and conveyance speed of the resin recording medium. Therefore, by using the image forming apparatus described below and toner for developing electrostatic images, it is possible to achieve a deposition amount of 10 g / m on a polyethylene terephthalate film having a thickness of 50 μm. 2 When creating a solid image, the density of the peaks on the surface of the solid image is set to 5000 to 100,000 mm -2 and the adhesion area ratio at the interface between the solid image and the polyethylene terephthalate film can be set within the range of 60 to 95%.

[0210] 1 is a schematic cross-sectional view of an example of an image forming apparatus, in which an image is formed on a sheet of resin recording medium P.

[0211] The image forming apparatus 100 is a so-called tandem color image forming apparatus, and includes an original image reading device SC, an image forming section, a transfer device, a conveying device, and a fixing device 50.

[0212] The document image reading device SC reads the image information of the document, converts it into image data of each color of YMCK, and sends the image data of the corresponding color to the exposure device 3 in the image forming section.

[0213] The four image forming units are devices for forming images of four colors, yellow (Y), magenta (M), cyan (C), and black (K), respectively, and are positioned in the order of YMCK from the top in Figure 1. Each image forming unit has a photoreceptor 1, a charging device 2, an exposure device 3, a developing device 4, a primary transfer roller 5, and a cleaning device 6.

[0214] In the image forming section, the surface of the rotating photoreceptor 1 is charged by applying a voltage from a charging device 2. An exposure device 3 irradiates the charged surface of the photoreceptor 1 with laser light corresponding to image data of the corresponding color of YMCK, forming an electrostatic image. Toner is supplied from a developing device 4 to the surface of the photoreceptor 1 on which the electrostatic image has been formed, and the toner adheres to the electrostatic image, developing the electrostatic image.

[0215] The transfer device includes a primary transfer roller 5, a cleaning device 6, an endless intermediate transfer belt 7, a plurality of rollers 8 that stretch the intermediate transfer belt 7, a secondary transfer roller 9, and a cleaning device 10.

[0216] During the primary transfer in the transfer device, the toner images of each color (Y, M, C, K) carried on the surface of the photoreceptor 1 are transferred onto the rotating intermediate transfer belt 7 so as to be successively superimposed upon each other by application of voltage from the primary transfer roller 5. This forms a composite color toner image on the intermediate transfer belt 7. The primary transfer roller 5 may contact the photoreceptor 1 only during the primary transfer. For example, the primary transfer roller 5 in the image forming unit for black images may always contact the photoreceptor 1, and the primary transfer rollers 5 for the other colors may contact the photoreceptor 1 only during the primary transfer. Any deposits, such as residual toner remaining on the surface of the photoreceptor 1 after the primary transfer, are removed from the surface by a cleaning device 6.

[0217] In the secondary transfer in the transfer device, the color toner image on the intermediate transfer belt 7 is transferred onto the resin recording medium P by application of voltage from the secondary transfer roller 9. The secondary transfer roller 9 is, for example, urged toward the intermediate transfer belt 7 only during the secondary transfer. After the secondary transfer, any deposits such as residual toner remaining on the surface of the intermediate transfer belt 7 are removed from the surface by a cleaning device 10.

[0218] The conveying device has a supply cassette 11, supply rollers 12, conveying rollers 13, registration rollers 14, discharge rollers 15, and a discharge tray 16. The conveying speed of the resin recording medium in the conveying device is not particularly limited, but it is preferable that the conveying speed of the resin recording medium be adjustable within a range of 155 to 665 mm / sec. The supply cassette 11 stores the resin recording medium P. The supply rollers 12 remove the resin recording medium P from the cassette 11. The conveying rollers 13 transport the resin recording medium P to the nip portion of the secondary transfer roller 9. The registration rollers 14 control the position of the transported resin recording medium P. The discharge rollers 15 discharge the resin recording medium P discharged from the fixing device 50 to the outside of the machine. The discharge tray 16 stores the resin recording medium P discharged to the outside of the machine.

[0219] In the fixing device 50, the color toner image on the resin recording medium P is fixed to the surface of the resin recording medium P by applying heat and pressure. As a result, a fixed color toner image is formed on the resin recording medium P. In addition, in the fixing device, the fixing temperature and fixing pressure are not particularly limited, but it is preferable that the fixing temperature can be adjusted within a range of 100 to 230°C and the fixing pressure can be adjusted within a range of 2500 to 3000 Pa.

[0220] 2 is a schematic cross-sectional view of an example of an image forming apparatus, in which an image is formed on a resin recording medium P wound in a roll.

[0221] The image forming apparatus 200 further includes a storage section 201, a transport unit 202, a transport unit 203, and a storage section 204 in addition to the components of the image forming apparatus 100. The storage section 201 stores a roll of resin recording medium P. The transport unit 202 transports continuous sheets of the resin recording medium P to the upstream portion of the transport device. The transport unit 203 transports the resin recording medium P on which a fixed toner image has been formed. The storage section 204 stores the resin recording medium P transported from the transport unit 203 in roll form.

[0222] In image forming apparatus 200, resin recording media P are continuously transported from storage section 201 toward secondary transfer roller 9 via transport unit 202. Also, in image forming apparatus 200, resin recording media P on which a toner image has been fixed by fixing device 50 is stored in a roll form in storage section 204 via transport unit 203. In image forming apparatus 200, a toner image is formed on resin recording media P using the same procedure as that for forming a toner image by image forming apparatus 100, except for the above.

[0223] 8. Image formation The image formed in this embodiment has a peak density of 5,000 to 100,000 mm -2 It is preferable that the adhesion area ratio at the interface between the resin recording medium and the image is in the range of 60 to 95%.

[0224] The toner used for forming an image can be the toner described above.The resin recording medium used for forming an image can be the resin recording medium described above.

[0225] The peak density of the toner image surface can be controlled by adjusting the toner composition as described above, and is also thought to be controllable by the fixing temperature, fixing pressure, conveyance speed of the resin recording medium, type of fixing belt, etc.

[0226] The adhesion area ratio at the interface between the resin recording medium and the toner image can be controlled by adjusting the toner composition as described above, and is also thought to be controllable by the type, thickness, fixing temperature, fixing pressure, conveyance speed of the resin recording medium, type of fixing belt, etc.

[0227] 9. Image evaluation method The image evaluation method of this embodiment is an image evaluation method for evaluating an image formed by fixing a toner for developing an electrostatic image on a resin recording medium. The image forming method includes a step of measuring the density of peaks on the surface of the image, and a step of measuring the density of peaks on the surface of the image, the step of measuring the density of peaks on the surface of the image, and a step of measuring the density of peaks on the surface of the image, the step of measuring the density of peaks on the surface of the image, and the ... -2 The method is characterized by comprising a step of determining whether the adhesion area ratio at the interface between the resin recording medium and the image is within the range of 60 to 95%, a step of measuring the adhesion area ratio at the interface between the resin recording medium and the image, and a step of determining whether the measured value of the adhesion area ratio is within the range of 60 to 95%.

[0228] Whether an image formed on a resin recording medium has excellent adhesiveness that satisfies both tape peeling durability and scratch resistance can be evaluated by measuring the peak density on the surface of the toner image and the adhesion area ratio at the interface between the resin recording medium and the toner image. For example, tape peeling tests and scratch tests may cause defects in the image, but by using this image evaluation method, it is possible to evaluate the image without causing any defects.

[0229] The methods for measuring the peak density on the surface of the toner image and the adhesion area ratio at the interface between the resin recording medium and the toner image are as described above. [Example]

[0230] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these. In the examples, the terms "parts" and "%" are used, but unless otherwise specified, they represent "parts by mass" or "% by mass." In the following examples, unless otherwise specified, all operations were carried out at room temperature (25°C).

[0231] Amorphous vinyl resin particle dispersion (B1), hybrid amorphous polyester particle dispersion (A1), and hybrid crystalline polyester particle dispersion (C1) were prepared according to the following procedures.

[0232] [Preparation example of amorphous vinyl resin particle dispersion (B1)] The following components were placed in a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a condenser, and a nitrogen introducing device, and the internal temperature was raised to 75°C while stirring at a stirring speed of 230 rpm under a nitrogen stream. Anionic surfactant "Dowfax (registered trademark)" (manufactured by The Dow Chemical Company) 5.0 parts by mass Ion-exchanged water 2500.0 parts by mass

[0233] Next, a solution containing the following components was added to the reaction vessel, and the liquid temperature was adjusted to 75°C. Potassium persulfate (KPS) 18.0 parts by mass Ion-exchanged water 342.0 parts by mass

[0234] Further, a mixed solution containing the following monomers and chain transfer agent was added dropwise over 2 hours. Styrene (St) 783.0 parts by mass n-Butyl acrylate (BA) 382.0 parts by mass Acrylic acid (AA) 42.0 parts by mass 1,10-decanediol diacrylate 3.0 parts by mass Dodecanethiol 8.1 parts by mass

[0235] After the dropwise addition was completed, the mixture was heated and stirred at 75°C for 2 hours to polymerize, yielding a dispersion of amorphous vinyl resin (b1). Ion-exchanged water was added to the dispersion to adjust the solid content to 25% by mass, yielding amorphous vinyl resin particle dispersion (B1). The volume-based median diameter (D50) of amorphous vinyl resin (b1) was measured using a Microtrac UPA-150 (manufactured by Nikkiso Co., Ltd.) and found to be 160 nm. The glass transition temperature (Tg) was 47°C, and the weight-average molecular weight (Mw) was 33,000.

[0236] [Synthesis example of hybrid amorphous polyester (a1)] The following amorphous polyester monomers other than trimellitic acid were placed in a four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple, and the temperature was raised to 235°C. (amorphous polyester segment) Polyhydric alcohol 1,6-Hexanediol 66.0 parts by mass Ethylene glycol 35.0 parts by mass Polycarboxylic acids Terephthalic acid 100.0 parts by mass Dodecenyl succinic acid 130.0 parts by mass Trimellitic acid 15.0 parts by mass

[0237] Next, the inside of the reaction vessel was purged with dry nitrogen gas, and 0.3 mass % of tin dioctanoate was added based on the total mass of the above monomer components. The above monomers were polycondensed under a nitrogen gas flow for 5 hours, and then reacted under a reduced pressure of 8 kPa for 1 hour.

[0238] After cooling the reactor to 170°C, a mixed solution of the vinyl resin monomer, bireactive monomer, and polymerization initiator shown below was placed in the dropping funnel and added dropwise over 1 hour. After that, the mixture was maintained at 170°C for 1 hour to carry out addition polymerization, and then the temperature was raised to 200°C and the reaction was carried out for 1 hour under a reduced pressure of 8 kPa. (Vinyl Resin Segment) Styrene (St) 39.9 parts by mass n-Butyl acrylate (BA) 8.0 parts by mass Acrylic acid (AA) 4.0 parts by mass Di-t-butyl peroxide (polymerization initiator) 7.5 parts by mass

[0239] Thereafter, the trimellitic acid was added and reacted for 1 hour at 210° C. The weight average molecular weight of the resulting hybrid amorphous polyester (a1) was 30,500.

[0240] [Synthesis example of hybrid amorphous polyester particle dispersion (A1)] The following components were placed in a reaction vessel equipped with a stirrer and dissolved at 75°C. Hybrid amorphous polyester resin (a1) 100.0 parts by mass Methyl ethyl ketone 60.0 parts by mass Isopropyl alcohol 15.0 parts by mass

[0241] Next, the reaction vessel was cooled to 70°C, and the following components were added dropwise to the reaction vessel over a period of 3 hours. 10% aqueous ammonia solution 3.5 parts by mass Ion-exchanged water 300.0 parts by mass

[0242] Next, methyl ethyl ketone and isopropyl alcohol were removed from the reaction solution using an evaporator to obtain a hybrid amorphous polyester particle dispersion (A1). The solids content of the obtained hybrid amorphous polyester particle dispersion (A1) was 25% by mass. The volume-based median diameter (D50) of the hybrid amorphous polyester (a1) particles in the hybrid amorphous polyester particle dispersion (A1) was 140 nm.

[0243] [Synthesis examples of hybrid amorphous polyester particle dispersions (A2) to (A9)] The type and parts by mass of the alcohol monomer and the parts by mass of each vinyl monomer were changed as shown in Tables I and II. Other than this, hybrid amorphous polyesters (a2) to (a9) were obtained using the same procedure as in the synthesis example of hybrid amorphous polyester (a1). Next, hybrid amorphous polyester (a1) was changed to (a2) to (a9). Other than this, hybrid amorphous polyester particle dispersions (A2) to (A9) were obtained using the same procedure as in the synthesis example of hybrid amorphous polyester particle dispersion (A1).

[0244] Tables I and II show the compositions of the hybrid amorphous polyester particle dispersions (A1) to (A9). The "ratio" in Table II refers to the ratio of the mass of the vinyl resin segment to the mass of the amorphous polyester segment. The mass of the amorphous polyester segment is the total mass of alcohol monomer 1, alcohol monomer 2, and acid monomer. The mass of the vinyl resin segment is the total mass of vinyl monomer 1, vinyl monomer 2, and vinyl monomer 3 (bireactive monomers). For example, in hybrid amorphous polyester particle dispersion (A1), the vinyl resin segment is 51.9 parts by mass relative to 346.0 parts by mass of the amorphous polyester segment. The ratio is 51.9 ÷ 346.0 = 0.150, or 15.0%.

[0245] [Table 1]

[0246] [Table 2]

[0247] [Synthesis example of hybrid crystalline polyester (c1)] The following crystalline polyester monomers were placed in a four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple, and the temperature was raised to 235°C. (crystalline polyester segment) Polycarboxylic acids Tetradodecanedioic acid 390.0 parts by mass Polyhydric alcohol 1,4-butanediol 140.0 parts by mass

[0248] Next, the atmosphere in the reaction vessel was replaced with dry nitrogen gas, and 0.3 mass % of tin dioctanoate was added based on the total mass of the monomer components. The monomers were polycondensed under a nitrogen gas flow for 5 hours, and then reacted under a reduced pressure of 8 kPa for 1 hour.

[0249] (Vinyl Resin Segment) Styrene (St) 20.4 parts by mass n-Butyl acrylate (BA) 4.1 parts by mass Acrylic acid (AA) 2.0 parts by mass Polymerization initiator (di-t-butyl peroxide) 2.1 parts by mass

[0250] After cooling the reactor to 170°C, the mixture of the vinyl resin monomer, bireactive monomer, and polymerization initiator was added dropwise to the dropping funnel over 1 hour, and the mixture was then maintained at 170°C for 1 hour for addition polymerization. The mixture was then heated to 200°C and reacted under a reduced pressure of 8 kPa for 1 hour. The resulting hybrid crystalline polyester (c1) had a weight average molecular weight of 9,500.

[0251] [Synthesis example of hybrid crystalline polyester particle dispersion (C1)] Hybrid crystalline polyester particle dispersion (C1) was obtained in the same manner as in the synthesis example of hybrid amorphous polyester particle dispersion (A1), except that hybrid amorphous polyester (a1) was replaced with hybrid crystalline polyester (c1).

[0252] [Synthesis example of hybrid crystalline polyester (c2)] The mass parts of each vinyl resin monomer and polymerization initiator were changed as shown in Table 3. Other than this, hybrid crystalline polyester (c2) was obtained using the same procedure as in the synthesis example of hybrid crystalline polyester (c1).

[0253] [Synthesis example of hybrid crystalline polyester particle dispersion (C2)] Hybrid crystalline polyester particle dispersion (C2) was obtained in the same manner as in the synthesis example of hybrid amorphous polyester particle dispersion (A1), except that hybrid amorphous polyester (a1) was replaced with hybrid crystalline polyester (c2).

[0254] Tables III and IV show the compositions of the hybrid crystalline polyester particle dispersions (C1) and (C2). The "ratio" in Table IV refers to the ratio of the mass of the vinyl resin segment to the mass of the crystalline polyester segment. The mass of the crystalline polyester segment is the total mass of the acid monomer and the alcohol monomer. The mass of the vinyl resin segment is the total mass of Vinyl Monomer 1, Vinyl Monomer 2, and Vinyl Monomer 3 (bireactive monomers). In the hybrid crystalline polyester particle dispersion (C1), the vinyl resin segment is 26.5 parts by mass relative to 530.0 parts by mass of the crystalline polyester segment. The ratio is 26.5 ÷ 530.0 = 0.050, or 5.0%.

[0255] [Table 3]

[0256] [Table 4]

[0257] [Preparation example of release agent particle dispersion (W1)] Release agent (behenyl behenate) 100.0 parts by mass Anionic surfactant "Neogen (registered trademark)" (Dai-ichi Kogyo Seiyaku Co., Ltd.) 1.0 parts by mass Ion-exchanged water 300.0 parts by mass

[0258] The above components were mixed and heated to 100°C, and dispersed using a homogenizer "Ultra Turrax T50" (manufactured by IKA Corporation). The mixture was then dispersed using a Manton-Gaulin high-pressure homogenizer (manufactured by Gaulin) to obtain a release agent particle dispersion (W1). The volume-based median diameter (D50) of the resulting release agent particles was 205 nm.

[0259] [Preparation example of cyan colorant particle dispersion (P1)] Cyan pigment (Dainichiseika Color & Chemicals Co., Ltd., Pigment Blue 15:3 (copper phthalocyanine)) 45.0 parts by mass Anionic surfactant "Neogen (registered trademark) R" (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2.0 parts by mass Ion-exchanged water 250.0 parts by mass

[0260] The above components were mixed and dispersed using a high-pressure impact disperser, Ultimizer HJP30006 (manufactured by Sugino Machine Co., Ltd.), to obtain a cyan colorant particle dispersion (P1). The volume-based median diameter (D50) of the resulting colorant particles was 150 nm.

[0261] [Production Example of Toner Base Particles (1)] <Aggregation and fusion process> The following materials were placed in a 4-liter reaction vessel equipped with a thermometer, pH meter, and stirrer, and 1.0% nitric acid was added at 25°C to adjust the pH to 3.0. Then, while dispersing at 3000 rpm using a homogenizer "ULTRA-TURRAX T50" (manufactured by IKA Corporation), 100 parts by mass of a 2% aqueous aluminum sulfate (flocculant) solution was added over 30 minutes. After the dropwise addition was complete, the mixture was stirred for 10 minutes to thoroughly mix the raw materials and flocculant. Vinyl resin particle dispersion (B1) 840.0 parts by mass Hybrid amorphous polyester particle dispersion (A1-first half) 48.0 parts by mass Hybrid crystalline polyester particle dispersion (C1) 120.0 parts by mass Release agent particle dispersion (W1) 120.0 parts by mass Cyan colorant particle dispersion (P1) 120.0 parts by mass Anionic surfactant "Dowfax2A1" (20% aqueous solution) 40.0 parts by mass Ion-exchanged water 1200.0 parts by mass

[0262] The reactor was then equipped with a stirrer and mantle heater, and the temperature was raised at a rate of 0.2°C / min up to 40°C, and then at a rate of 0.05°C / min after reaching 40°C, while the stirrer's rotation speed was adjusted to ensure sufficient stirring. The particle size was measured every 10 minutes using a Coulter Multisizer 3 (aperture diameter 100 μm, manufactured by Beckman Coulter, Inc.). When the volume average particle size reached 5.8 μm, the temperature was maintained and used as core particles. Next, a premixed liquid containing the following components was added over a 20-minute period.

[0263] Hybrid amorphous polyester particle dispersion (A1-later) 192.0 parts by mass Anionic surfactant "Dowfax2A1" (20% aqueous solution) 15.0 parts by mass

[0264] Next, after maintaining the temperature at 50°C for 30 minutes, 8 parts by mass of a 20% solution of EDTA (ethylenediaminetetraacetic acid) was added to the reaction vessel, and then a 1 mol / L aqueous solution of sodium hydroxide was added to control the pH of the raw material dispersion to 9.0. Thereafter, the temperature was increased to 85°C at a rate of 1°C / min while adjusting the pH to 9.0 every 5°C, and the temperature was maintained at 85°C.

[0265] ≪Cooling process≫ Thereafter, using a flow particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation), the mixture was cooled at a temperature decrease rate of 10°C / min when the shape factor reached 0.965, to obtain toner base particle dispersion 1 having a core-shell structure. The volume-based median diameter (D50) of the particles in toner base particle dispersion 1 was 6.0 μm, and the average circularity was 0.965.

[0266] <Filtration and washing process> Thereafter, the toner base particle dispersion liquid 1 was filtered and thoroughly washed with ion-exchanged water.

[0267] ≪Drying process≫ Next, the washed toner base particle dispersion liquid was dried at 30° C. to obtain toner base particles 1.

[0268] [Production Examples of Toner Base Particles 2 to 17] Toner base particles 2 to 17 were prepared in the same manner as toner base particles 1, except that the type and amount of each dispersion liquid was changed as shown in Tables V and VI.

[0269] Tables V and VI show the configurations of toner base particles 1 to 17. "-" in the table indicates that the corresponding ingredient is not contained, i.e., was not added. For toner base particles 11, hybrid amorphous polyester particle dispersion A was added only in the first stage to form core particles. Thereafter, no dispersion A was added in the second stage to form a shell layer. The core particles were manufactured so that the volume average particle size was 6.0 μm.

[0270] The "ratio" in Tables V and VI indicates the ratio relative to the total mass of the binder resin in the toner base particles. For example, in toner base particle 1, the total mass of the binder resin is 70.0 mass% vinyl resin, 20.0 mass% hybrid amorphous polyester, and 10.0 mass% hybrid crystalline polyester. The "total ratio of front and rear" in Table VI indicates the sum of the ratio of the front stage (core particle) and the rear stage (shell layer). For example, in toner base particle 1, of the 20.0 mass% hybrid amorphous polyester, 4.0 mass% is contained in the core particle and 16.0 mass% is contained in the shell layer.

[0271] [Table 5]

[0272] [Table 6]

[0273] [Toner 1 manufacturing example] ≪External addition process≫ Toner base particles 1 100.0 parts by mass Hydrophobic silica particles (number average primary particle size: 12 nm, hydrophobicity: 68) 1.0 parts by mass Hydrophobic titanium oxide particles (number average primary particle size: 20 nm, hydrophobicity: 63) 0.5 parts by mass Sol-gel silica (number average primary particle diameter: 110 nm) 1.0 parts by mass

[0274] The above components were mixed for 20 minutes using a Henschel mixer (manufactured by Nippon Coke and Engineering Co., Ltd.) at a rotor peripheral speed of 35 mm / sec and 32° C. After mixing, coarse particles were removed using a sieve with 45 μm openings, and toner 1 was obtained.

[0275] [Toner 2-17 manufacturing example] Toner base particles 1 were changed to toner base particles 2 to 17, respectively. Except for this, toners 2 to 17 were produced in the same manner as toner 1.

[0276] [Example of manufacturing developer 1] Toner 1 and an acrylic resin-coated ferrite carrier having a volume average particle size of 32 μm were added and mixed so that the toner concentration was 7.0 mass %, thereby preparing developer 1, which is a two-component developer containing toner 1.

[0277] [Manufacturing examples of developers 2 to 17] Toner 1 was changed to Toners 2 to 17, respectively. Except for this, Developers 2 to 17 were prepared in the same manner as Developer 1.

[0278] [Example 1] A color copier "AccurioLabel 400" (manufactured by Konica Minolta, Inc.) was prepared, which had been modified so that the fixing temperature, fixing pressure, toner adhesion amount, and conveying speed could be freely set. Each of the two-component developers obtained was then loaded into the color multifunction printer in order. Under an environment of normal temperature and humidity (temperature 20°C, humidity 50% RH), the toner adhesion amount on a resin recording medium was measured to be 10 g / m. 2 Then, an experiment was conducted to fix an unfixed image of a solid patch having a size of 100 mm square.

[0279] The image fixing experiment was conducted at a fixing pressure of 2700 Pa and a transport speed of 550 mm / sec, with the fixing temperature increasing in 2°C increments from 100°C. The lowest fixing temperature at which image contamination due to fixation offset was not visually observed (UO avoidance temperature) was defined as the minimum fixing temperature. The fixing temperature for image formation using each developer was set at the minimum fixing temperature + 15°C. In this image forming apparatus, the resin recording medium was transported through the image forming apparatus in a rolled state and then rerolled after the toner image was formed. In this way, images were formed on the resin recording medium that was installed in a rolled state and then rerolled and stored after printing. A 50 μm-thick corona-treated polyethylene terephthalate film (manufactured by Lintec Corporation) was used as the resin recording medium.

[0280] [Examples 2 to 10, 13 and Comparative Examples 1 to 6] The developer was changed as shown in Table 7. Except for this, an image was formed on a resin recording medium in the same manner as in Example 1.

[0281] [Examples 11 and 12] The thickness of the resin recording medium was changed as shown in Table VII. Except for this, images were formed on the resin recording medium using the same procedure as in Example 1. For the resin recording medium, an 85 μm thick corona-treated polyethylene terephthalate film was used in Example 11, and a 75 μm thick corona-treated polyethylene terephthalate film was used in Example 12.

[0282] [Example 14] An image was formed on the resin recording medium in the same manner as in Example 1, except that the resin recording medium was changed to a 50 μm thick polyethylene terephthalate film that had not been corona-treated.

[0283] The images obtained in Examples 1 to 14 and Comparative Examples 1 to 6 were evaluated for "adhesion" and "gloss unevenness" by the following methods. The "adhesion" evaluation was carried out by a tape peel test and a scratch test.

[0284] [Tape peeling test] 3 is an explanatory diagram of the tape peeling test. Points A101 to A103 are points on a line L2 parallel to one side of a 100 mm square solid patch image 300. Point A102 is the center point of solid patch image 300, and the interval between points A101, A102, and A103 is 20 mm.

[0285] The reflection densities of the image at three points, A101 to A103, were measured using a fluorescence spectrodensitometer "FD-7" (manufactured by Konica Minolta, Inc.), and the arithmetic mean value of the reflection densities of the solid patch images was calculated. Next, "Cellotape (registered trademark) CT-15" (15 mm wide, manufactured by Nichiban Co., Ltd.) was cut to a length of 60 mm. A 50 mm length of tape 301 was lightly applied to the center of the image, including points A101 to A103, as shown in Figure 3, leaving a 10 mm tip of the tape. The tape 301 was then rubbed five times back and forth with a pressure of 1 kPa. The tape was peeled from the 10 mm tip, leaving a peel angle of 180°, at a speed of 200 mm / s. The reflection densities of the image after peeling at three points, A101 to A103 in Figure 3, were measured using the same procedure as above, and the arithmetic mean value was calculated. The reflection densities of the image before and after peeling were used to calculate the residual rate after tape peeling according to the following formula: (Formula) Residual rate (%) = (Reflection density after peeling / Reflection density before peeling) x 100

[0286] As shown in Figure 3, the tape peeling test was performed using the same procedure on three points on line L1 and three points on line L3. The remaining rates after tape peeling were determined for each of line L1, line L2, and line L3, and the arithmetic mean values ​​of these were calculated. Note that lines L1, L2, and L3 are lines that divide the solid patch image 300 into four equal parts.

[0287] The tape peel durability was evaluated based on the remaining rate after tape peeling according to the following criteria. A higher value for the remaining rate after tape peeling indicates higher tape peel durability. In this evaluation, the remaining rate after tape peeling was ranked from 1 to 10 according to the following criteria. A rank of 2 or higher was considered pass, and a rank of 1 was considered fail.

[0288] 10: The survival rate is 92% or more. 9: The survival rate is 88% or more but less than 92%. 8: The survival rate is 84% ​​or more but less than 88%. 7: The survival rate is 80% or more but less than 84%. 6: The survival rate is 76% or more but less than 80%. 5: The survival rate is 72% or more but less than 76%. 4: The survival rate is 68% or more but less than 72%. 3: The survival rate is 64% or more but less than 68%. 2: The survival rate is 60% or more but less than 64%. 1: The survival rate is less than 60%.

[0289] [Scratch test] Scratch durability was evaluated using a continuous load scratch resistance tester (manufactured by Shinto Scientific Co., Ltd.). A logger was installed in the continuous load scratch resistance tester to log the continuous output of "time" and the "resistance value" received by the needle. A 0.1 mm diameter sapphire scratching needle was installed in the continuous load scratch resistance tester, and the speed adjustment dial was turned so that the scratching needle moved at a speed of 100 mm / min. Next, 100 g continuous load weights were placed in two locations to set the maximum load to 100 gf in variable load mode. The lever was turned to unlock, and the position of the continuous load weights was adjusted so that the arm with the needle at its tip was horizontal.

[0290] FIG. 4 is an explanatory diagram of the scratch test. Lines C101 to C104 are parallel to one side of a 100 mm square solid patch image 300, dividing the solid patch image 300 into five equal parts. The solid patch image 300 was placed and fixed on a table so that the needle would scratch the image along line C101. The load value was set to 0, and the arm was slowly lowered. The moment the tip of the needle made slight contact with the image surface, the arm's descent was stopped and the load value was reset to 0. The start button was pressed to start scratching, and the time from when the needle peeled the image and exposed the resin recording medium was measured. The inflection point load was calculated from that time. Specifically, time was converted to load, and a graph of load and resistance was created. The load value at the inflection point where the resistance suddenly increased was defined as the inflection point load. After cleaning the needle tip, the scratch test was performed on lines C102 to C104 using the same procedure, and the average value of the four inflection point loads was calculated. A higher inflection point load indicates higher scratch resistance. In this evaluation, scratch resistance was ranked from 1 to 10 according to the following criteria. A rank of 2 or higher was considered pass, and a rank of 1 was considered fail.

[0291] 10: The inflection point load is 26 gf (0.255 N) or more. 9: The inflection point load is 24 gf (0.235 N) or more and less than 26 gf (0.255 N). 8: The inflection point load is 22 gf (0.216 N) or more and less than 24 gf (0.235 N). 7: The inflection point load is 20 gf (0.196 N) or more and less than 22 gf (0.216 N). 6: The inflection point load is 18gf (0.177N) or more and less than 20gf (0.196N). 5: The inflection point load is 16 gf (0.157 N) or more and less than 18 gf (0.177 N). 4: The inflection point load is 14gf (0.137N) or more and less than 16gf (0.157N). 3: The inflection point load is 12 gf (0.118 N) or more and less than 14 gf (0.137 N). 2: The inflection point load is 10 gf (0.098 N) or more and less than 12 gf (0.118 N). 1: The inflection point load is less than 10 gf (0.098 N).

[0292] [Uneven gloss] For a 100 mm square solid patch image, the number of areas that could be visually recognized as having different gloss and their reflection density differences were determined. The areas with different gloss and other areas were measured using a fluorescent spectrodensitometer "FD-7" (Konica Minolta, Inc.). For other areas, measurements were taken at three random points and the average was calculated. The maximum difference between this average and the reflection density of each area with different gloss was calculated. In this evaluation, gloss unevenness was ranked from 1 to 5 according to the following criteria based on the number of areas with different gloss and the maximum reflection density difference. A rank of 2 or higher was considered pass, and a rank of 1 was considered fail. The lower rank was selected between the number and the maximum reflection density difference. If there were no areas with different gloss, the reflection density difference was not evaluated and the rank was assigned a 5.

[0293] (Number of areas) 5: The number of areas with different gloss is 0. 4: The number of areas with different gloss is one. 3: The number of areas with different gloss is two. 2: The number of areas with different gloss is three. 1: The number of areas with different gloss is 4 or more.

[0294] (Maximum reflection density difference) 4: The maximum reflection density difference is less than 0.1. 3: The maximum reflection density difference is 0.1 or more and less than 0.2. 2: The maximum reflection density difference is 0.2 or more and less than 0.3. 1: The maximum reflection density difference is 0.3 or more.

[0295] The evaluation results are shown in Table VII. The toner adhesion amount is 10 g / m 2 to 4g / m 2When the images were evaluated using the same procedure with the above changes, Examples 1 to 14 met the pass criteria for all evaluation items.

[0296] [Table 7]

[0297] From the examples and comparative examples, it is clear that the toner of this embodiment improves the adhesiveness (tape peeling durability and scratch resistance) to a resin recording medium and reduces uneven gloss of an image.

[0298] Examples 1 and 6 to 8 reveal the following. In the toner of the present embodiment, the aliphatic polyhydric alcohol is a non-alicyclic aliphatic polyhydric alcohol having 5 or more carbon atoms, and therefore the toner can improve adhesion to a resin recording medium.

[0299] Examples 9 and 10 reveal the following. When the binder resin contains a crystalline polyester having no vinyl resin segment, the adhesiveness to the resin recording medium can be improved more than when the binder resin does not contain a crystalline resin. Furthermore, Examples 1 and 10 reveal the following. The binder resin containing a hybrid crystalline polyester having a vinyl resin segment can improve adhesion to a resin recording medium more than the binder resin containing a crystalline polyester having no vinyl resin segment.

[0300] Examples 1 and 13 and Comparative Example 1 reveal the following. The toner of this embodiment has a core-shell structure, and the shell layer contains a hybrid amorphous polyester, which can improve adhesion to a resin recording medium.

[0301] Examples 1 to 3 and Comparative Examples 3 and 4 reveal the following. The toner and the image forming method of the present embodiment are suitable for forming a toner image having a peak density of 5,000 to 100,000 mm-2 By keeping the thickness within this range, it is possible to achieve both tape peeling durability and scratch resistance, and to improve adhesion to a resin recording medium.

[0302] Examples 4 and 5 and Comparative Examples 1, 2, 5 and 6 reveal the following. In the toner and image forming method of the present embodiment, the adhesion area ratio is in the range of 60 to 95%, so that it is possible to improve the adhesion to the resin recording medium and reduce uneven glossiness at the same time.

[0303] Examples 1, 11 and 12 reveal the following. In the image forming method of this embodiment, the thickness of the resin recording medium is 75 μm or less, so that the adhesiveness to the resin recording medium can be improved.

[0304] Examples 1 and 14 reveal the following. In the image forming method of this embodiment, the adhesiveness to the resin recording medium can be improved by surface treating the resin recording medium. [Explanation of symbols]

[0305] 1 photoreceptor 2. Charging device 3 Exposure equipment 4. Developing device 5 Primary transfer roller 6 Cleaning Device 7 Intermediate transfer belt 8 Roller 9 Secondary transfer roller 10 Cleaning device 11 Supply cassette 12 Supply roller 13 Transport roller 14 Resist Roller 15 Ejection roller 16 Output tray 50 Fixing device 100 Image forming device 200 Image forming device 201 Storage Unit 202 Transport unit 203 Transport Unit 204 Storage area 300 solid patch images 301 Tape SC Document Image Reader P Resin recording medium

Claims

1. A toner for developing electrostatic images, comprising toner base particles containing a binder resin, the binder resin contains a hybrid amorphous polyester, the content of the hybrid amorphous polyester is within a range of 5 to 50 parts by mass relative to 100 parts by mass of the binder resin; the hybrid amorphous polyester has an amorphous polyester segment and a vinyl resin segment, the amorphous polyester segment is a condensation polymer of a polycarboxylic acid and a polyhydric alcohol, the polyhydric alcohol comprises an aliphatic polyhydric alcohol, the vinyl resin segment contains a structural unit derived from a vinyl monomer, The content of the vinyl resin segment is in the range of 3 to 30 parts by mass relative to 100 parts by mass of the amorphous polyester segment.

1. A toner for developing electrostatic images, comprising:

2. The aliphatic polyhydric alcohol is a non-alicyclic aliphatic polyhydric alcohol having 5 or more carbon atoms.

2. The toner for developing electrostatic images according to claim 1.

3. The vinyl monomer includes styrenes and (meth)acrylic acid esters.

3. The toner for developing electrostatic images according to claim 1 or 2.

4. the binder resin contains a hybrid crystalline polyester, the hybrid crystalline polyester has a crystalline polyester segment and a vinyl resin segment, the crystalline polyester segment is a condensation polymer of a polycarboxylic acid and a polyhydric alcohol, The vinyl resin segment contains a structural unit derived from a vinyl monomer.

3. The toner for developing electrostatic images according to claim 1 or 2.

5. It has a core-shell structure, The shell layer contains the hybrid amorphous polyester.

3. The toner for developing electrostatic images according to claim 1 or 2.

6. It has a core-shell structure, The core particles contain a styrene-acrylic resin.

3. The toner for developing electrostatic images according to claim 1 or 2.

7. Adhesion amount 4 g / m on resin recording medium ２ When the above solid image is formed, The density of the peaks on the surface of the solid image is 5,000 to 100,000 mm －２ is within the range of The adhesion area ratio at the interface between the resin recording medium and the solid image is within the range of 60 to 95%.

3. The toner for developing electrostatic images according to claim 1 or 2.

8. A toner for developing electrostatic images according to claim 1 or 2, comprising a carrier. A two-component developer for developing electrostatic images.

9. 1. An electrophotographic image forming method including a step of fixing an electrostatic image developing toner on a resin recording medium to form an image, Adhesion amount: 4 g / m ２ When creating the above solid images, The density of the peaks on the surface of the solid image is 5,000 to 100,000 mm －２ is within the range of The adhesion area ratio at the interface between the resin recording medium and the solid image is within the range of 60 to 95%. An image forming method comprising:

10. 1. An electrophotographic image forming method including a step of fixing an electrostatic image developing toner on a resin recording medium to form an image, Adhesion amount 10 g / m to a polyethylene terephthalate film with a thickness of 50 μm ２ When creating a solid image, The density of the peaks on the surface of the solid image is 5,000 to 100,000 mm －２ is within the range of The adhesion area ratio at the interface between the polyethylene terephthalate film and the solid image is in the range of 60 to 95%. An image forming method comprising:

11. Fixing occurs at a fixing temperature within the range of 100 to 230°C, a fixing pressure within the range of 2500 to 3000 Pa, and a conveying speed of the resin recording medium within the range of 155 to 665 mm / sec.

11. The image forming method according to claim 9 or 10.

12. The resin recording medium is a continuous-feed medium.

11. The image forming method according to claim 9 or 10.

13. The thickness of the resin recording medium is 75 μm or less.

11. The image forming method according to claim 9 or 10.

14. The resin recording medium is surface-treated.

11. The image forming method according to claim 9 or 10.

15. An electrophotographic image forming system that forms an image by fixing electrostatic image developing toner on a resin recording medium, Adhesion amount 10 g / m to a polyethylene terephthalate film with a thickness of 50 μm ２ When creating a solid image, The density of the peaks on the surface of the solid image is 5,000 to 100,000 mm －２ Within the range of a means for controlling the adhesion area ratio at the interface between the solid image and the polyethylene terephthalate film to be within the range of 60 to 95%; An image forming system comprising:

16. 1. An image evaluation method for evaluating an image formed by fixing a toner for developing an electrostatic image on a resin recording medium, comprising: measuring the density of peaks on the surface of the image; The measured value of the peak density is 5,000 to 100,000 mm －２ determining whether the range is a step of measuring an adhesion area ratio at the interface between the resin recording medium and the image; and determining whether the measured value of the adhesion area ratio is within a range of 60 to 95%. An image evaluation method comprising:

Images