Image forming method

Abstract

To provide an image forming method that allows easy close adhesion of an edge of a laminate film and suppresses entry of air bubbles into a laminated portion.SOLUTION: An image forming method according to the present invention performs lamination processing by: overlaying a laminate film on at least one surface of a recording medium on which a toner image has been formed using toner; and heating and pressurizing the laminate film. Therein the toner has toner base particles containing a hydrocarbon compound having 35 or fewer carbon atoms, and a content of the hydrocarbon compound having 35 or fewer carbon atoms is 0.1 mass% or less in the toner base particles as measured by a gas chromatography method.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image forming method, and more particularly to an image forming method that facilitates adhesion of the edges of a laminate film and prevents air bubbles from being trapped in the laminated portion. [Background technology]

[0002] Decades ago, laminating film was often used to prevent photographs from fading. Later, laminating film came to be used in offices to preserve important documents. At that time, the print rate of images was low, so the compatibility between the laminating film and the recording medium, paper, was more important than the performance of the toner when it came to image quality after lamination. BACKGROUND ART Known laminating devices include devices that laminate a strip-shaped film onto continuously transported paper sheets (see, for example, Patent Document 1).

[0003] In recent years, a method of printing photographic images using a copier, laminating them, and selling them has become mainstream. In this case, photographic images are output, so the images are color and have a high print coverage, which means that the impact of toner lamination is significant. It has become clear that when laminating prints with a high toner coverage, the physical properties of the toner, especially the physical properties during lamination, have a significant impact.

[0004] Furthermore, recently, restaurant menus have begun to use laminated color images. In these cases, thicker colored paper is often preferred over regular copy paper. When laminating thick paper, the laminating film tends to peel off from the areas where it does not adhere. Therefore, there is a demand for laminating films with wider edges. However, when laminating films with wider edges, air bubbles get trapped in the edges, and it is difficult to remove the air bubbles. Furthermore, if the laminator temperature setting or pressure is increased in an attempt to seal the edges, this can cause the laminator to malfunction or shorten its lifespan. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-72116 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above problems and circumstances, and its problem to be solved is to provide an image forming method that makes it easy to adhere the edges of a laminate film and that makes it difficult for air bubbles to get into the laminated area. [Means for solving the problem]

[0007] The present inventors have investigated the causes of the above problems in order to solve the above problems, and as a result have found that by incorporating a small amount of hydrocarbon wax and a hydrocarbon compound having 35 or less carbon atoms into toner base particles, it is possible to provide an image forming method that facilitates adhesion of the edges of a laminate film and prevents air bubbles from being trapped in the laminated portion. That is, the above-mentioned problems of the present invention are solved by the following means.

[0008] 1. An image forming method in which a lamination process is carried out by superposing a laminating film on at least one side of a recording medium on which a toner image has been formed using a toner, and then heating and pressing the film, the toner has toner base particles containing a hydrocarbon compound having 35 or less carbon atoms and a release agent, the release agent contains a hydrocarbon wax; The content of the hydrocarbon compound having 35 or less carbon atoms in the toner base particles is 0.1% by mass or less as measured by gas chromatography. An image forming method comprising:

[0009] 2. The content of the hydrocarbon wax in the toner base particles is within a range of 0.1 to 50% by mass. 2. The image forming method according to claim 1,

[0010] 3. In the lamination process, the heating temperature is within the range of 100 to 200°C. 2. The image forming method according to claim 1,

[0011] 4. The thickness of the laminate film is within the range of 80 to 250 μm. 2. The image forming method according to claim 1,

[0012] 5. The thickness of the recording medium is within the range of 50 to 300 μm. 2. The image forming method according to claim 1, [Effects of the Invention]

[0013] The above-described means of the present invention can provide an image forming method in which the edges of the laminate film are easily adhered to each other and air bubbles are less likely to be trapped in the laminated portion. 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. To ensure good adhesion of the edges of the laminate film, the toner must have a high viscosity during lamination. Also, to prevent air bubbles from forming during lamination, the toner must be resistant to volatilization. Ester-based waxes are generally known to have the property of being less likely to volatilize during lamination. This is presumably due to their relatively high molecular weight components. However, at lamination temperatures, such as a set temperature of 200°C, the viscosity drops too much, causing the ester-based wax to penetrate from the image area into the laminate, making it difficult for the edges of the laminate film to adhere. On the other hand, hydrocarbon waxes have a suitably high viscosity at the high lamination temperatures without dropping too much like ester waxes, resulting in good edge adhesion of the laminate film. However, if the toner contains too much low molecular weight component, it will volatilize and air bubbles will be easily generated. Therefore, the inventors conducted extensive research and found that the viscosity of the toner is optimal and the toner is less likely to volatilize when a hydrocarbon wax is used as a release agent and the content of hydrocarbon compounds with 35 or less carbon atoms in the toner base particles is 0.1% by mass or less. As a result, the edges of the laminate film adhere more easily and air bubbles are less likely to form in the laminated area. [Brief explanation of the drawings]

[0014] [Figure 1] Schematic diagram showing an example of a spheronization treatment device for performing spheronization treatment. [Figure 2] Schematic diagram showing an example of a surface treatment device that performs surface treatment using hot air [Figure 3] Schematic diagram of an image forming system [Figure 4] Enlarged view showing the configuration of the laminating device DETAILED DESCRIPTION OF THE INVENTION

[0015] The image forming method of the present invention is an image forming method in which a laminating process is performed by overlaying a laminate film on at least one side of a recording medium on which a toner image has been formed using a toner, and then heating and pressurizing the laminate film, wherein the toner has toner base particles containing a hydrocarbon compound having 35 or less carbon atoms and a release agent, the release agent contains a hydrocarbon wax, and the content of the hydrocarbon compound having 35 or less carbon atoms in the toner base particles is 0.1 mass% or less as measured by gas chromatography. This feature is a technical feature common to or corresponding to each of the following embodiments.

[0016] In an embodiment of the present invention, the content of the hydrocarbon wax in the toner base particles is preferably within a range of 0.1 to 50% by mass. The hydrocarbon wax has a molecular structure similar to that of the hydrocarbon compound having 35 or fewer carbon atoms. This makes it easier for the hydrocarbon compound having 35 or fewer carbon atoms to be compatible with the hydrocarbon wax, and for the hydrocarbon compound having 35 or fewer carbon atoms to be more finely and uniformly dispersed in the toner base particles. Furthermore, the hydrocarbon wax is more likely to be eluted from the toner base particles together with the hydrocarbon wax during fixing, ensuring better fluidity and adhesion to the laminate film. In particular, by ensuring that the hydrocarbon wax content is within the above range, viscosity during lamination is more suitably increased, resulting in good adhesion of the laminate film and less generation of air bubbles in the laminated area.

[0017] In the lamination treatment, heating within a range of 100 to 200° C. is preferred in that the adhesion of the laminate film is good and breakdowns of the laminator and shortening of its lifespan can be prevented.

[0018] It is preferable that the thickness of the laminate film is within the range of 80 to 250 μm, since this ensures good adhesion at the edge of the laminate film and prevents air bubbles from forming in the laminated portion.

[0019] The thickness of the recording medium is within the range of 50 to 300 μm, which is preferable in that it can be applied to recording media such as thick paper.

[0020] The present invention, its components, and embodiments and modes for carrying out the present invention will be described below. In this application, the symbol "to" is used to mean that the numerical values ​​before and after it are included as lower and upper limits.

[0021] [Outline of the image forming method of the present invention] The image forming method of the present invention is an image forming method in which a laminating process is performed by superposing a laminating film on at least one side of a recording medium on which a toner image has been formed using a toner, and then heating and pressurizing the laminated film, wherein the toner has toner base particles containing a hydrocarbon compound having 35 or less carbon atoms and a release agent, the release agent contains a hydrocarbon wax, and the content of the hydrocarbon compound having 35 or less carbon atoms in the toner base particles is 0.1% by mass or less as measured by gas chromatography. It is characterized by:

[0022] In this specification, the term "toner" refers to a toner for developing an electrostatic latent image. The toner includes toner particles having toner base particles and an external additive disposed on the surface of the toner base particles. "Toner base particles" are the components that make up the base of "toner particles." "Toner base particles" are called "toner particles" when external additives are added. "Toner" refers to an aggregate of toner particles. The toner according to the present invention has toner base particles containing a hydrocarbon compound having 35 or less carbon atoms and a release agent (wax). The toner base particles preferably further contain a binder resin, and may contain other components such as a colorant and a charge control agent as needed. In the present invention, the term "toner image" refers to a state in which toner particles are aggregated in an image shape.

[0023] <Hydrocarbon compounds with 35 or less carbon atoms> The toner base particles contain a hydrocarbon compound having a carbon number of not more than 35. The hydrocarbon compound having a carbon number of not more than 35 is preferably a saturated hydrocarbon compound having a carbon number of 16 or more and not more than 35. Hereinafter, "hydrocarbon compounds with 35 or less carbon atoms" will also be referred to as "C35 or less compounds." "Saturated hydrocarbon compounds with 16 to 35 carbon atoms" will also be referred to as "C16-35 saturated compounds." The content of C35 or lower compounds in the toner base particles is 0.1% by mass or less as measured by gas chromatography, i.e., the content of C35 or lower compounds is 0.1% by mass or less based on the total amount of binder resin, release agent, C35 or lower compounds, colorant, etc. that constitute the toner base particles.

[0024] The content of compounds of C35 or less is determined as follows. First, C35 or smaller compounds are separated from the toner using a solvent that dissolves them, and then hydrocarbons with these carbon numbers are characterized using gas chromatography mass spectrometry (GC-MS).The amount of these hydrocarbons is then quantified using a flame ionization detector (GC-FID) as the detector for gas chromatography. It should be noted that the extract extracted from the toner may also contain unsaturated hydrocarbons, so after extraction, polar groups may be added to the unsaturated bonds, and only saturated hydrocarbons may be separated by column separation utilizing the difference in polarity.

[0025] At this time, multiple internal standards may be added (dissolved) in the solvent to determine whether the quantification and pretreatment were carried out appropriately. The concentration of the internal standards to be added may be set according to the amount of C35 or lower compounds (estimated amount obtained by provisional measurement, etc.).

[0026] The internal standard is preferably a saturated hydrocarbon compound not normally found in toner. For example, using n-undecane or n-tridecane can detect the loss of saturated hydrocarbon compounds due to volatilization during pretreatment, and can serve as a guide for the elution time of the target saturated hydrocarbon compound during solid-phase extraction or GC-FID analysis. Furthermore, bicyclohexyl is less likely to overlap with the elution time of compounds of C35 or less, making it easier to improve detection accuracy.

[0027] Extraction from the toner can be performed by a conventionally known method such as a solid-liquid extraction method, a method in which the toner is dissolved or swelled and then separated by centrifugation, a Soxhlet extraction method, a high-speed solvent extraction method, etc. A method can be selected from these methods depending on the predicted carbon number of the C35 or less compound and the type of compound that will become an impurity component such as a binder resin.

[0028] The solvent used for extraction is not particularly limited, but n-hexane, which has a high solubility for compounds of C35 or less, is preferred. Depending on the type of binder resin, polar solvents such as dichloromethane and ethanol may be used in combination to swell the binder resin.

[0029] The method for introducing polar groups into unsaturated hydrocarbons contained in the extract is not particularly limited. Examples of the introduction method include epoxidation using metachloroperbenzoic acid (mCPBA), addition of hydrogen halide, addition of water or alcohol using an acid catalyst, and derivatization into alcohol by oxidation after hydroboration. Among these, epoxidation using mCPBA is preferred due to its high reactivity and reaction selectivity. In this case, for example, 1 The progress of the reaction can be confirmed by confirming the disappearance of the double bond peak by H-NMR measurement. Note that the addition of polar groups may be omitted if sufficient detection accuracy can be ensured depending on the type of saturated hydrocarbon or unsaturated hydrocarbon.

[0030] Separation utilizing the difference in polarity can be performed by known methods such as solid-phase extraction, online or offline GC, etc. When it is expected that a large amount of impurities will be contained, separation by solid-phase extraction is preferable.

[0031] The solvent used for solid-phase extraction is preferably n-hexane for both conditioning and extraction of saturated hydrocarbons. A polar solvent may also be used depending on the type of contaminants expected. After collecting the fraction containing C35 or lower compounds, it is preferable to increase the polarity of the solvent and collect the fraction. The absence of saturated hydrocarbon components is then confirmed by qualitative analysis using GC / MS or similar.

[0032] As the solid phase for solid-phase extraction, a highly polar solid phase used in normal-phase separation using polar interactions can be used. Examples of the solid phase include silica gel, silica gel activated with polar substances such as anhydrous sodium sulfate and silver nitrate, diol, cyanopropyl, magnesium silicate, etc. Among these, activated silica activated with silver nitrate is preferred. Note that alumina is preferably not used because it specifically retains long-chain n-alkanes.

[0033] The fraction containing saturated hydrocarbons extracted by solid-phase extraction is preferably concentrated or diluted to a concentration appropriate for qualitative and quantitative analysis by gas chromatography by a method such as vacuum concentration using an evaporator or concentration using a nitrogen stream, etc. The concentration conditions should be such that the internal standard does not disappear due to concentration of low-boiling point components. The fractions after solid phase extraction can be subjected to GC-FID under the following conditions, for example, to quantify compounds of C35 or less.

[0034] (GC conditions) Equipment used: Shimadzu GC-2010 Plus Injection volume: 1 μL, saturated hydrocarbon concentration: 500 to 1000 mg / L Guard column: Restek MXT Siltek (10 m x 0.53 mm id) Column: Restek MTX-1 (15 m x 0.25 mm id) x 0.1 μm df) Carrier gas: Helium

[0035] The elution times of n-alkanes (number of carbon atoms: 10, 16, 24, 35, and 50) measured under the same conditions are measured in advance. In addition, a blank chromatogram is prepared in advance by injecting only n-hexane into the above-mentioned apparatus.

[0036] A blank chromatogram obtained by measuring only the solvent is subtracted from the chromatogram obtained for the toner to determine the baseline. It is preferable that a horizontal baseline be created at the lowest point before and after the peak derived from the saturated hydrocarbon compound. However, if a horizontal baseline cannot be created even after subtracting the blank chromatogram due to column bleeding or other reasons, the baseline can be set by a horizontal line from the elution time of the C10 compound to the elution time of the C50 compound, whichever has the lower signal intensity.

[0037] Then, vertical lines are drawn on the chromatogram at positions corresponding to the elution times of carbon atoms 1 and 35, and the area of ​​the chromatogram above the baseline enclosed by these vertical lines is calculated. Peaks that are confirmed not to be saturated hydrocarbon compounds are excluded from the calculation. The mass of the C35 or lower compounds can be calculated from this area. When an internal standard is used, the mass of the C35 or lower compounds can be calculated from the ratio of the above area to the area of ​​the compound added as the internal standard. The amount of the C35 or lower compounds in the toner base particles can then be calculated by dividing the calculated mass of the C35 or lower compounds by the mass of the toner base particles.

[0038] [toner] The composition of the toner will be described below. <Toner base particles> As described above, the toner contains toner base particles and external additives. The toner base particles preferably contain a release agent and the C35 or lower compound, and further contain a binder resin, and may contain other components such as a colorant and a charge control agent as needed.

[0039] (binder resin) The toner base particles contain a binder resin, which allows the toner to be fixed onto the recording medium. The binder resin may be a thermoplastic resin or a thermosetting resin, but is preferably a thermoplastic resin. Examples of thermoplastic resins include styrene resins, vinyl resins (such as acrylic resins and styrene-acrylic resins), polyesters, silicone resins, olefin resins, polyamides, and epoxy resins.

[0040] The binder resin may be an amorphous resin or a crystalline resin, or may be a composite resin in which a crystalline resin and an amorphous resin are hybridized. In this specification, a crystalline resin refers to a resin whose melting point is observed in measurement by differential scanning calorimetry (DSC), and an amorphous resin refers to a resin whose melting point is not observed in measurement by DSC. In this specification, the observation of a melting point in a resin means that, when measured by DSC at a heating rate of 10°C / min, an endothermic peak having a half-width of 15°C or less is observed.

[0041] Examples of binder resins include styrene-based polymers (styrene homopolymers, homopolymers of styrene substitutes such as poly-p-chlorostyrene and polyvinyltoluene, and styrene-based copolymers such as styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-butadiene copolymer, and styrene-isoprene copolymer), polyvinyl chloride, phenolic resins, vinyl resins such as (meth)acrylic resins (including styrene-(meth)acrylic acid ester copolymer, styrene-α-chloromethyl(meth)acrylate copolymer, styrene-(meth)acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, and styrene-acrylonitrile-indene copolymer), polyvinyl acetate, silicone resins, polyesters, polyurethane resins, polyamides, furan resins, epoxy resins, xylene resins, polyvinyl butyral, terpene resins, coumarone-indene resins, natural resins, modified natural resins (naturally modified phenolic resins, natural resin-modified maleic acid resins, and other petroleum-based resins), and the like. Among these, vinyl resins such as styrene-acrylic resins and polyesters are preferred as binder resins.

[0042] In this specification, (meth)acrylic means acrylic or methacrylic, (meth)acrylonitrile means acrylonitrile or methacrylonitrile, and (meth)acrylate means acrylate and methacrylate, respectively.

[0043] The polyester is preferably a crystalline polyester. When the toner contains a crystalline polyester, the melt viscosity of the toner is reduced, and the C35 or lower compound can be more easily precipitated on the image surface. Furthermore, when a toner contains crystalline polyester, C35 or lower compounds are less likely to separate from the toner during transport within an image forming device. While the reason for this is unclear, it is thought that the crystalline polyester crystallized within the toner forms domains with a lamellar structure, making it easier for C35 or lower compounds to be trapped within the lamellar structure. As a result, when a toner contains crystalline polyester, image smearing is less likely to occur even when images are continuously formed.

[0044] The crystalline polyester is usually obtained by subjecting a polycarboxylic acid and a polyhydric alcohol to a dehydration condensation reaction by a known method.

[0045] The polycarboxylic acid may be a divalent or higher carboxylic acid, such as trimellitic acid, pyromellitic acid, etc. Among these, dicarboxylic acids are preferred from the viewpoint of increasing the crystallinity of the crystalline polyester. Examples of dicarboxylic acids include aliphatic carboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid (dodecanedioic acid), 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, and 1,18-octadecanedicarboxylic acid, as well as aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4′-biphenyldicarboxylic acid. The crystalline polyester may contain only structural units derived from one of these carboxylic acids, or may contain structural units derived from two or more of these carboxylic acids.

[0046] Among these, aliphatic carboxylic acids are preferred because they are likely to increase the crystallinity of the crystalline polyester. The aliphatic carboxylic acid preferably has a linear hydrocarbon group having from 6 to 16 carbon atoms, and more preferably has a linear hydrocarbon group having from 10 to 14 carbon atoms. The hydrocarbon structure of the aliphatic carboxylic acid may be partially branched.

[0047] The polyhydric alcohol may be a dihydric or higher alcohol, such as glycerin, pentaerythritol, trimethylolpropane, sorbitol, etc. Among these, dihydric alcohols are preferred from the viewpoint of increasing the crystallinity of the crystalline polyester. Examples of the dihydric alcohol include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,20-eicosanediol; diols having an unsaturated double bond such as 2-butene-1,4-diol, 3-hexene-1,6-diol, and 4-octene-1,8-diol; and diols having a sulfonic acid group.

[0048] In order to fully achieve the above-mentioned effects, the content of the crystalline polyester is preferably within a range of 5 to 20 parts by mass, and more preferably within a range of 8 to 15 parts by mass, per 100 parts by mass of the total amount of the binder resin. From the viewpoint of sufficiently softening the toner base particles and enhancing the low-temperature fixability of the toner, the melting point of the crystalline polyester is preferably within a range of 50 to 85°C, and more preferably within a range of 60 to 80°C.

[0049] The melting point of the crystalline polyester can be measured using a toner differential scanning calorimeter (Diamond DSC, manufactured by PerkinElmer). Measurements are performed under the following measurement conditions (heating and cooling conditions): a first heating process in which the temperature is raised from room temperature (25°C) to 150°C at a rate of 10°C / min and isothermally maintained at 150°C for 5 minutes, a cooling process in which the temperature is lowered from 150°C to 0°C at a rate of 10°C / min and isothermally maintained at 0°C for 5 minutes, and a second heating process in which the temperature is raised from 0°C to 150°C at a rate of 10°C / min. The above measurement is performed by sealing 3.0 mg of toner in an aluminum pan and setting it in the sample holder of a differential scanning calorimeter "Diamond DSC." An empty aluminum pan is used as a reference. In the above measurement, the endothermic curve obtained in the first heating process is analyzed, and the top temperature of the endothermic peak derived from the crystalline resin is taken as the melting point of the crystalline resin.

[0050] The weight average molecular weight (Mw) of the crystalline polyester is preferably 5,000 or more and 50,000 or less. The number average molecular weight (Mn) of the crystalline polyester is preferably 2,000 or more and 10,000 or less. When the weight average molecular weight (Mw) and number average molecular weight (Mn) of the crystalline polyester are within the above ranges, the low temperature fixability is improved. The weight average molecular weight (Mw) can be determined using a GPC apparatus equipped with an "HLC-8220" (manufactured by Tosoh Corporation) and a "TSKguard column + TSKgel Super HZM-M triple column" (manufactured by Tosoh Corporation) as columns, and a calibration curve determined from a standard polystyrene sample.

[0051] The content of the binder resin is preferably in the range of 20 to 99% by mass, more preferably in the range of 30 to 95% by mass, and even more preferably in the range of 40 to 90% by mass, based on the total mass of the toner base particles. When the content of the binder resin is 20% by mass or more, the strength of the formed image can be further increased.

[0052] (mold release agent) The release agent enhances the releasability of the toner from the fixing member and the like. In this specification, the release agents described below do not fall under the category of C35 or lower compounds. Although C35 or lower compounds also have the effect of enhancing the releasability of toner from fixing members to a certain extent, when simply referred to as a "release agent" below, it means a release agent that does not include C35 or lower compounds.

[0053] The release agent contains a hydrocarbon wax, which prevents the viscosity from decreasing too much at the set temperature during lamination, as occurs with ester-based waxes, and keeps the viscosity appropriately high, resulting in good edge adhesion of the laminate film. In this specification, the hydrocarbon wax refers to a hydrocarbon compound having 36 to 76 carbon atoms, which may have a linear or branched chain.

[0054] As the hydrocarbon wax, for example, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax are preferable.

[0055] (paraffin wax) "Paraffin wax" refers to a mixture of hydrocarbons with a molecular weight of approximately 300 to 500, primarily consisting of straight-chain paraffin hydrocarbons (normal paraffins) with 20 to 40 carbon atoms, and which may contain small amounts of branched hydrocarbons (isoparaffins). Examples of paraffin waxes include Paraffin Wax-155, Paraffin Wax-135, Paraffin Wax-115, HNP-3, HNP-9, HNP-11, SP-0165, SP-1039, SP-3040 (all manufactured by Nippon Seiro Co., Ltd.), etc.

[0056] (microcrystalline wax) "Microcrystalline wax" is a wax extracted primarily from the residual oil fraction obtained by vacuum distillation of crude oil. It is a wax containing branched hydrocarbons (isoparaffins) and saturated cyclic hydrocarbons (cycloparaffins). Microcrystalline wax contains a large amount of low-crystalline isoparaffins and cycloparaffins, resulting in smaller crystals and a larger molecular weight than paraffin wax.

[0057] Such microcrystalline wax has a carbon number of 30 to 60, a weight average molecular weight (Mw) of 500 to 800, and a melting point of 60 to 90°C. The microcrystalline wax used in the present invention preferably has a carbon number of 36 or more, a weight average molecular weight (Mw) of 600 to 800, and a melting point of 60 to 85°C. Also, a low molecular weight wax is preferred, particularly one with a number average molecular weight (Mn) of 300 to 1000, and more preferably 400 to 800. The ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw / Mn) is preferably 1.01 to 1.20.

[0058] Examples of microcrystalline waxes include Hi-MiC-1045, Hi-MiC-1070, Hi-MiC-1080, Hi-MiC-1090, Hi-MiC-2045, Hi-MiC-2065, Hi-MiC-2095, EMW-0001, EMW-0003 (all manufactured by Nippon Seiro Co., Ltd.), and the like.

[0059] The hydrocarbon wax preferably has a melting point of 60 to 85°C. When the melting point of the hydrocarbon wax is within the range of 60 to 85°C, the hydrocarbon wax is more likely to elute from the toner base particles during fixing, and the C35 or lower compounds are also more likely to elute along with the hydrocarbon wax. As a result, the toner base particles are more likely to melt, the low-temperature fixability of the toner is improved, and the fluidity of the toner is ensured, resulting in good adhesion of the laminate film during lamination. From the above perspectives, the melting point of the hydrocarbon wax (particularly a hydrocarbon wax having 36 to 76 carbon atoms) is more preferably 80 to 90°C.

[0060] The content of the hydrocarbon wax is preferably 0.1 to 50% by mass, more preferably 0.5 to 10% by mass, and particularly preferably 1 to 5% by mass, based on the total mass of the toner base particles. By having the content of the hydrocarbon wax within this range, viscosity during lamination is suitably increased. As a result, adhesion of the laminate film is good, and air bubbles are less likely to form in the laminated portion.

[0061] (Compounds below C35) By incorporating a C35 or lower compound into the toner base particles, the viscosity at high lamination temperatures is favorable, as described above, and the edges of the laminate film are easily adhered to each other. Furthermore, the C35 or lower compound also has the effect of enhancing the releasability of the toner from fixing members, etc., to a predetermined extent. The content of the C35 or lower compound is within the range of 0.1% by mass or less of the toner base particles, as measured by the gas chromatography method. The details of the compounds below C35 have been described above, so the explanation will be omitted.

[0062] (Other ingredients) The toner base particles may contain a colorant, a charge control agent, and the like.

[0063] The colorant may be a dye or a pigment. When the toner is a color toner that imparts a predetermined color tone to an image, the toner base particles may contain a colorant such as yellow, magenta, cyan, or black, depending on the color tone to be exhibited by the color toner. The toner base particles may contain only one type of colorant, or a combination of multiple types of colorants.

[0064] Examples of yellow colorants include yellow dyes, including CI Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, and 162, and yellow pigments, including CI Pigment Yellow 14, 17, 74, 93, 94, 138, 155, 180, and 185.

[0065] Examples of magenta colorants include magenta dyes, including CI Solvent Red 1, 49, 52, 58, 63, 111, and 122, and magenta pigments, such as CI Pigment Red 5, 48:1, 53:1, 57:1, 122, 139, 144, 149, 166, 177, 178, and 222.

[0066] Examples of cyan colorants include cyan dyes such as CI Solvent Blue 25, 36, 60, 70, 93, and 95, and cyan pigments such as CI Pigment Blue 1, 7, 15, 15:3, 60, 62, 66, and 76.

[0067] Examples of black colorants include carbon blacks such as channel black, furnace black, acetylene black, thermal black, and lamp black, magnetic materials such as ferrite and magnetite, and iron-titanium composite oxides.

[0068] The content of the colorant is preferably 0.5 to 20% by mass, more preferably 2 to 10% by mass, relative to the total mass of the toner base particles. When the toner is a clear toner, the toner base particles preferably do not substantially contain a colorant, and the content of the colorant relative to the total mass of the toner base particles is preferably 0.1% by mass or less.

[0069] The charge control agent can adjust the chargeability of the toner base particles. Examples of charge control agents include nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, metal salicylates or metal complexes thereof, and the like.

[0070] The content of the charge control agent is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total mass of the binder resin. Attempting to control the chargeability of the toner by adding an excessive amount of charge control agent may significantly change other properties of the toner base particles. In contrast, in this embodiment, the chargeability of the toner is adjusted using strontium titanate as an external additive, so that the chargeability of the toner can be adjusted to a desired level while satisfying other required properties.

[0071] <External additives> The toner base particles may contain an external additive that is added to the surface of the toner base particles as a post-treatment agent in order to improve the fluidity, chargeability and cleaning properties of the toner.

[0072] (strontium titanate) The external additive preferably contains strontium titanate particles. Depending on the production method or composition, strontium titanate can have any of several particle shapes, including cubic or rectangular parallelepiped, irregular shape, and rounded cubic shape. Although strontium titanate may have any of these particle shapes, rectangular parallelepiped shape is preferred.

[0073] The shape of the strontium titanate particles can be confirmed by observation with a scanning electron microscope (SEM). Strontium titanate having these shapes forms planar exposed portions on the surfaces of the toner base particles, which provides appropriate fluidity and allows for both adhesion and prevention of bubble generation.

[0074] In order to effectively exert the above-mentioned effects, the number average primary particle diameter of strontium titanate is preferably within a range of 20 to 200 nm, and more preferably within a range of 30 to 150 nm.

[0075] The number-average primary particle diameter of strontium titanate can be determined by binarizing image data of strontium titanate taken with a scanning electron microscope (SEM) using an image processing analyzer (LUZEX AP, manufactured by Nireco Corporation) and averaging the horizontal Feret diameters measured for 100 particles.

[0076] The content of strontium titanate is preferably in the range of 0.05 to 2.0% by mass, more preferably 0.1 to 1.0% by mass, based on the total mass of the toner. When the content of strontium titanate is 0.05% by mass or more, optimal irregularities can be formed on the laminate film, contributing to improved adhesion of the laminate film.

[0077] Strontium titanate can be produced by a normal pressure heating reaction method in which a titanium oxide source and a strontium oxide source are mixed together, and then an alkaline aqueous solution is added while heating (warming) at normal pressure.

[0078] The titanium oxide source can be a mineral acid peptized product of a titanium compound hydrolysate. The titanium oxide source is preferably prepared by peptizing metatitanic acid obtained by a sulfuric acid method and having an SO content of 1.0 mass % or less (preferably 0.5 mass % or less) with hydrochloric acid to adjust the pH to 0.8 to 1.5.

[0079] As the strontium oxide source, metal nitrates, hydrochlorides, etc. For example, strontium nitrate and strontium chloride can be used as the strontium oxide source.

[0080] As the alkaline aqueous solution, a caustic alkali can be used, and an aqueous sodium hydroxide solution is preferred.

[0081] The particle size of the strontium titanate particles can be adjusted by the mixing ratio of the titanium oxide source and the strontium oxide source, the concentration of the titanium oxide source at the beginning of the reaction, and the temperature and addition rate when adding the alkaline aqueous solution. In order to prevent the formation of carbonate during the reaction process, it is preferable to prevent the incorporation of carbon dioxide gas during the reaction by, for example, carrying out the reaction in a nitrogen gas atmosphere.

[0082] The mixing ratio of the titanium oxide source and the strontium oxide source during the reaction is preferably in the range of 0.90 to 1.40, more preferably 1.05 to 1.20, in terms of the molar ratio of SrO / TiO2. Within this range, unreacted titanium oxide is less likely to remain. The concentration of the titanium oxide source at the beginning of the reaction is preferably 0.05 to 1.30 mol / L, more preferably 0.08 to 1.00 mol / L, based on TiO2.

[0083] The temperature of the mixture when the aqueous alkaline solution is added is preferably within the range of 60 to 100°C.

[0084] The slower the addition rate of the alkaline aqueous solution, the larger the particle size of the strontium titanate particles obtained, and the faster the addition rate, the smaller the particle size of the strontium titanate particles obtained. The addition rate of the alkaline aqueous solution is preferably 0.001 to 1.2 equivalents / h, and more preferably 0.002 to 1.1 equivalents / h, based on the amount of raw materials charged. The addition rate of the alkaline aqueous solution can also be adjusted appropriately depending on the particle size of the strontium titanate to be obtained.

[0085] The strontium titanate particles thus obtained are preferably further treated with an acid. When the mixing ratio of the titanium oxide source to the strontium oxide source exceeds 1.0 in terms of the molar ratio of SrO / TiO2, the unreacted metal sources other than titanium remaining after the reaction may react with carbon dioxide in the air to produce impurities such as metal carbonates. To prevent performance degradation due to these impurities, it is preferable to add an alkaline aqueous solution and then perform an acid treatment to remove the unreacted metal sources.

[0086] The acid treatment is preferably carried out using hydrochloric acid, nitric acid, acetic acid, or the like at a pH range of 2.5 to 7.0, more preferably 4.5 to 6.0.

[0087] (Other external additives) The external additive may contain particles primarily composed of an inorganic material other than strontium titanate, such as silica particles, alumina particles, zirconia particles, zinc oxide particles, chromium oxide particles, cerium oxide particles, antimony oxide particles, tungsten oxide particles, tin oxide particles, tellurium oxide particles, manganese oxide particles, and boron oxide particles. These particles primarily composed of an inorganic material may be hydrophobized, if necessary, with a surface treatment agent such as a silane coupling agent or silicone oil. The particle diameter of these particles is preferably 20 to 200 nm in number-average primary particle diameter measured by the same method as for strontium titanate. The particle diameter is more preferably 30 to 150 nm.

[0088] The external additive may also contain particles whose main component is an organic material containing a homopolymer such as styrene or methyl methacrylate, or a copolymer thereof, etc. The particle size of these particles is preferably 10 to 1000 nm, as measured by the same method as for strontium titanate, at the peak top.

[0089] The external additive may also contain a lubricant such as a metal salt of a higher fatty acid. Examples of such higher fatty acids include stearic acid, oleic acid, palmitic acid, linoleic acid, and ricinoleic acid. Examples of metals that constitute the metal salt include zinc, manganese, aluminum, iron, copper, magnesium, and calcium.

[0090] The content of these external additives is preferably such that the total amount of the external additives together with strontium titanate is 0.05 to 5.0 parts by mass relative to the total mass of the toner base particles.

[0091] [Method for producing toner base particles and toner] The toner base particles can be produced in the same manner as known toners by a pulverization method, an emulsion polymerization aggregation method, an emulsion aggregation method, a suspension polymerization method, a dissolution suspension method, or the like. Of these, the pulverization method, emulsion polymerization aggregation method, emulsion aggregation method, or suspension polymerization method is preferred, the pulverization method or emulsion polymerization aggregation method is more preferred, and the pulverization method is even more preferred.

[0092] The toner base particles of pulverized toner produced by the pulverization method are irregular particles with numerous randomly distributed minute irregularities throughout the particle, resulting in a large surface area. Therefore, toner base particles produced by the pulverization method allow C35 and lower compounds to easily leach out from their surfaces, ensuring better fluidity and adhesion to the laminate film. Furthermore, because optimal irregularities are formed throughout the particle, adhesion to the laminate film is improved, preventing the formation of air bubbles in the laminate.

[0093] In the pulverization method, a binder resin, a release agent, a C35 or lower compound, and other materials are mixed and melted and kneaded to obtain a solid resin composition, which is then pulverized to a predetermined particle size to obtain toner base particles.

[0094] More specifically, in the pulverization method, predetermined amounts of materials constituting the toner base particles, such as a binder resin, a release agent, a C35 or lower compound, and optionally other materials, are weighed, blended, and mixed. Mixing can be carried out using a mixing device such as a double cone mixer, V-type mixer, drum mixer, super mixer, Henschel mixer, Nauta mixer, or Mechano Hybrid.

[0095] Next, the mixed materials are melt-kneaded. For melt-kneading, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. For continuous production, it is preferable to use a single-screw extruder or a twin-screw extruder. Examples of twin-screw extruders include a KTK twin-screw extruder (manufactured by Kobe Steel, Ltd.), a TEM twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), a PCM kneader (manufactured by Ikegai Corporation), a twin-screw extruder (manufactured by KCK Corporation), a Ko-Kneader (manufactured by Buss Co., Ltd.), and a Kneedex (manufactured by Nippon Coke and Engineering Co., Ltd.). The melt-kneading temperature is preferably about 100 to 200°C. The resin composition obtained by melt-kneading is rolled using a two-roll mill or the like and quenched with water or the like to form a solid.

[0096] Next, the solid resin composition obtained by melt-kneading and cooling is pulverized to a desired particle size. For example, the pulverization may be performed by coarsely pulverizing the resin composition using a pulverizer such as a crusher, hammer mill, or feather mill, followed by fine pulverization using a pulverizer such as a Cryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), a Super Rotor (manufactured by Nisshin Engineering Inc.), or a Turbo Mill (manufactured by Freund Turbo Corporation), or an air-jet pulverizer.

[0097] Thereafter, the pulverized resin composition is classified as needed using a classifier or sieving machine such as an inertial classification type Elbow Jet (manufactured by Nittetsu Mining Co., Ltd.), a centrifugal classification type Turboplex (manufactured by Hosokawa Micron Corporation), a TSP Separator (manufactured by Hosokawa Micron Corporation), or a Faculty (manufactured by Hosokawa Micron Corporation). In this manner, toner base particles can be produced by the pulverization method.

[0098] (spherical processing) In this embodiment, the toner base particles obtained by the above-described method are subjected to a spheronization process by repeatedly applying mechanical energy by impact force in an environment of 15 to 55°C. By performing the spheronization process while applying impacts to the toner base particles, the release agent and C35 or lower compounds on the outer (surface) side of the toner base particles are easily removed. For example, by colliding the toner base particles with the wall surface of a flow channel or a collision plate in a device that performs the spheronization process, the release agent and C35 or lower compounds on the toner surface are removed, and the spheronization process can be performed while they adhere to the wall surface or the collision plate. Furthermore, by carrying out the above treatment at a low temperature, the release agent and C35 or lower compounds inside the toner can be prevented from melting and dissolving excessively onto the surface of the toner, allowing for optimal dissolution and improving the adhesion of the laminate film.

[0099] From this viewpoint, the environmental temperature at which the spheronization treatment is carried out is preferably 20 to 50°C, more preferably 25 to 40°C, and even more preferably 25 to 35°C. The time for impacting the toner base particles is preferably 1 to 20 minutes, and more preferably 5 to 15 minutes. By impacting the toner base particles for 5 minutes or longer, the release agent and C35 or lower compounds are more likely to be released from the surface of the toner base particles, and the release agent and C35 or lower compounds are more likely to be concentrated in the interior of the toner, improving the long-term storage stability of the toner. By impacting the toner base particles for 15 minutes or less, excessive reduction in the content of C35 or lower compounds and release agent in the toner base particles can be suppressed.

[0100] FIG. 1 is a schematic diagram showing an example of a spheronization processing device 80 for performing spheronization processing. The spheronization device 80 has a raw material hopper 81, a stirring motor 82, an ultrasonic nozzle 83, an impact plate 84, a recycling collector 85, a collection cyclone 86, and a raw material inlet 87. In Fig. 1, 88 represents compressed air, 89 represents an exhaust air outlet, and T represents toner base particles. In the spheronization device 80, the toner collides with the walls of the flow path (particularly, the impact plate 84), thereby spheronizing the toner base particles.

[0101] In this embodiment, the toner base particles that have been subjected to the above-described spheronization treatment may be used as core particles, and the surfaces of the core particles may be coated with shell resin particles to produce toner base particles with a two-layer structure (core-shell structure). This increases the ratio of the amount of release agent and C35 or lower compounds present on the inner side of the toner base particles relative to the surface side, making it easier to satisfy W3 / S3≦0.1. As a result, heat-resistant storage stability can be improved, and image smearing can be more effectively prevented even when images are continuously formed. The core-shell structure is not limited to a structure in which the shell layer completely covers the core particle, but may also be a structure in which the shell layer does not completely cover the core particle and includes a portion where the core particle is exposed.

[0102] Toner base particles having a core-shell structure can be produced by mixing toner base particles obtained by a pulverization method with a dispersion of shell resin particles in an aqueous medium, dispersing these particles, adding an aggregating agent, and heating the mixture to a temperature equal to or higher than the softening point of the toner base particles that will become core particles, thereby fusing the core particles and the shell resin particles.

[0103] Next, the toner particles are subjected to solid-liquid separation from the dispersion of toner particles in which the core particles and shell resin particles are fused together, and the toner cake (a cake-like aggregate of toner particles in a wet state) obtained by the solid-liquid separation is washed to remove any attached surfactants, aggregating agents, etc. After the solid-liquid separation, the washed toner cake is dried.

[0104] The type of shell resin may be the same as or different from the binder resin in the core particles.

[0105] The type of the aggregating agent is not particularly limited, but for example, metal salts such as alkali metal salts and salts of metals of Group 2 can be used. Examples of the metal salts include monovalent metal salts such as sodium, potassium, and lithium, divalent metal salts such as calcium, magnesium, manganese, and copper, and trivalent metal salts such as iron and aluminum. Specific examples of metal salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, and aluminum sulfate. These flocculants can be used alone or in combination of two or more.

[0106] The method for solid-liquid separation is not particularly limited, but examples thereof include centrifugal separation, reduced pressure filtration using a Nutsche or the like, and filtration using a filter press or the like.

[0107] The drying method is not particularly limited, and examples thereof include a spray dryer, a vacuum freeze dryer, a reduced pressure dryer, etc. From the viewpoint of production stability, it is preferable to use a stationary shelf dryer, a mobile dryer, a fluidized bed dryer, a rotary dryer, an agitator dryer, etc. In this way, toner base particles having a core-shell structure can be prepared.

[0108] The toner base particles having a core-shell structure may be prepared by mixing a dispersion of resin particles to be core particles with a dispersion of colorant particles, aggregating the mixture to a predetermined particle size, adding a dispersion of resin particles for shells, and then adding an aggregating agent. In this case, after adding the aggregating agent, the mixture of the dispersions is heated and stirred at an elevated temperature.

[0109] (Hot air surface treatment) In this embodiment, the toner base particles obtained by the above-described method may be subjected to a surface treatment using hot air before being subjected to a spheronization treatment. In this case, the temperature of the hot air is preferably 200°C or less in order to cause the release agent and the C35 or lower compound to be unevenly distributed to the inside of the toner base particles to some extent. The lower limit of the hot air temperature is not particularly limited, but is preferably 100°C.

[0110] The method of surface treatment using hot air is not particularly limited, and can be carried out by methods such as those described in JP-A-59-125743 and JP-A-2022-96557. These publications describe a surface treatment method in which toner particles are caused to fall while being rotated by hot air in a heat treatment chamber, and then cooled by cold air supplied into the heat treatment chamber, and the toner particles are then collected.

[0111] FIG. 2 is a schematic diagram showing an example of a surface treatment device 90 for performing surface treatment using hot air. Toner particles supplied from a hopper 91 are mixed with compressed air supplied from a nozzle 93 in a mixing chamber 92, and are ejected as a dispersed airflow 94 from a diffuser 95 into the interior of a heat treatment chamber 96. Hot air, which has been supplied to a hot air swirling chamber 97 and made into a swirling flow, is blown into this ejected dispersed airflow 94, causing the toner particles in the dispersed airflow 94 to swirl with the hot air. The toner particles that have been heat-treated by the swirling are cooled by cooling air introduced from a cold air supply unit 98 along the side wall of the heat treatment chamber 96, and are then discharged and collected from a discharge unit 99.

[0112] When preparing toner by emulsion polymerization aggregation, a release agent and a C35 or lower compound are added to a binder resin particle dispersion and aggregated to a certain extent. Then, additional binder resin particle dispersion that does not contain a C35 or lower compound is added, and the added binder resin is allowed to adhere to the surface of the aggregated particles, thereby producing toner base particles in which the release agent and the C35 or lower compound are unevenly distributed to the interior of the toner base particles to a certain extent.

[0113] (Volume average particle size of toner base particles) The volume average particle size of the toner base particles obtained through the above steps is preferably within a range of 4 to 8 μm, and more preferably within a range of 5 to 7 μm.

[0114] The volume-average particle size of the toner base particles is the volume-based median diameter (D 50 ) can be measured and calculated using, for example, a device consisting of a Coulter Multisizer 3 (manufactured by Beckman Coulter) connected to a computer system (manufactured by Beckman Coulter) equipped with data processing software "Software V3.51." The measurement procedure involves dispersing 0.02 g of toner particles in 20 mL of surfactant solution, allowing the particles to settle, and then ultrasonically dispersing the particles for 1 minute to prepare a toner particle dispersion. The surfactant solution may be, for example, a solution prepared by diluting a neutral detergent containing a surfactant component with pure water by a factor of 10. This toner particle dispersion is added dropwise to an ISOTON II (Beckman Coulter) beaker until the measurement concentration reaches 5 to 10%, and the measurement is performed by setting the measuring instrument count to 25,000 particles. Here, the aperture diameter of the Multisizer 3 used is 100 μm. The measurement is carried out by dividing the range of 2 to 60 μm into 256 parts and calculating the frequency, and the particle diameter of the particle with the largest volume cumulative fraction of 50% is taken as the volume-based median diameter (D 50 ) and use this as the volume average particle size of the toner base particles.

[0115] (Addition of external additives) The toner base particles obtained through the above steps may be used as they are, but may be subjected to an external addition treatment with an external additive, if necessary. The external addition treatment using an external additive can be carried out by blending a predetermined amount of toner base particles and an external additive, and stirring and mixing the mixture using a mixing device such as a double cone mixer, a V-type mixer, a drum mixer, a super mixer, a Henschel mixer, a Nauta mixer, a Mechano Hybrid (manufactured by Nippon Coke and Engineering Co., Ltd.), or a Nobilta (manufactured by Hosokawa Micron Corporation).

[0116] [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. When the toner is used as a two-component developer, the carrier may be magnetic particles made of a conventionally known material. Examples of materials for the magnetic particles include metals such as iron, ferrite, and magnetite; alloys of these metals with aluminum; and alloys of metals such as lead. Among these, ferrite particles are preferred.

[0117] 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 fine powder is dispersed in a binder resin.

[0118] The volume-based median diameter of the carrier (D 50 The volume-based median diameter (D) of the carrier is preferably in the range of 20 to 100 μm, and more preferably in the range of 25 to 80 μm. 50 ) can be measured, for example, by a laser diffraction particle size distribution measuring device "HELOS" (manufactured by SYMPATEC) equipped with a wet disperser.

[0119] 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.

[0120] The toner content in the developer is preferably within a range of 4.0 to 8.0% by mass relative to the total mass of the developer.

[0121] [Image forming method] The image forming method of the present invention involves forming a toner image by an electrophotographic method using a developer comprising the toner described above, and then laminating the toner image by overlaying a laminate film on at least one side of the recording medium on which the toner image has been formed, and then heating and pressing the laminate film. The developer may be a magnetic or non-magnetic single 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.

[0122] The electrophotographic toner image formation preferably includes a charging step, a step of forming an electrostatic image, a developing step, a transferring step, a fixing step, and a cleaning step. The image forming method of the present invention further includes a step of laminating the recording medium on which the toner image has been formed.

[0123] In the charging step, the electrophotographic photosensitive member is charged. In the process of forming an electrostatic image, an electrostatic image is formed on an electrophotographic photosensitive member. The formation of the electrostatic image is carried out, for example, by uniformly charging the surface of the electrophotographic photosensitive member with a charging means and then imagewise exposing the surface of the electrophotographic photosensitive member with an exposure means. The term "electrostatic image" refers to an image formed on the surface of the electrophotographic photosensitive member by such a charging means. In the developing step, the electrostatic image is developed with the developer to form a toner image. In the transfer step, the toner image is transferred to a recording medium by peeling and charging the toner image onto the recording medium.

[0124] In the fixing step, the unfixed image (toner image) is fixed to the recording medium by, for example, passing the recording medium onto which the unfixed image (toner image) has been transferred between a heated fixing belt or fixing roller and a pressure member. The fixing process may be a process in which the toner image is fixed to the recording medium in two stages. By fixing in two stages, the toner image can be heated sufficiently and for a long period of time, and the C35 or lower compounds can be suitably eluted from the toner base particles. As a result, the adhesion of the laminate film can be improved. In the cleaning step, developer that has not been used for image formation or that has not been transferred and remains on a developer carrier such as a photoreceptor or intermediate transfer member is removed from the developer carrier.

[0125] In the laminating step, a laminating film is placed on the recording medium on which the toner image has been fixed. The lamination treatment is preferably carried out by heating within a range of 100 to 200° C. The lamination treatment is preferably carried out while applying pressure to the paper within a range of 0.05 to 10 MPa.

[0126] (Recording medium) The recording medium is not particularly limited. Examples include plain paper ranging from thin paper to thick paper, coated printing paper such as high-quality paper, art paper, or coated paper, commercially available paper such as Japanese paper or postcard paper, resin films such as polypropylene (PP) film, polyethylene terephthalate (PET) film, and triacetyl cellulose (TAC) film, and cloth. The color of the recording medium is also not particularly limited, and recording media of various colors can be used. The thickness of the recording medium is not particularly limited, but is preferably within the range of 50 to 350 μm.

[0127] (laminating film) The laminate film includes a transparent resin film layer and an adhesive layer formed on the surface of the transparent resin film layer that covers the toner image. The type of the transparent resin film layer is not particularly limited, but may be, for example, a plastic film. Examples of materials for the plastic film include polypropylene (PP), polyethylene terephthalate (PET), nylon, etc. The plastic film may be stretched.

[0128] The material of the adhesive layer is not particularly limited, but may be, for example, ethylene-vinyl acetate (EVA) copolymer resin, acrylic resin, or the like.

[0129] The thickness of the laminate film is not particularly limited, but is preferably within the range of 80 to 250 μm, more preferably within the range of 75 to 250 μm, and particularly preferably within the range of 100 to 150 μm. The thickness of the adhesive layer is not particularly limited, but is preferably within the range of 12 to 30 μm. The laminate film may be in the form of a sheet or a continuous film.

[0130] [Image formation system] In the image forming method, an image forming system 1 including an image forming apparatus 10 and a laminating apparatus 20 can be used, as shown in FIG. 3 is a diagram showing the configuration of an image forming system. The image forming apparatus described below is an example of an electrophotographic image forming apparatus, but is not limited to this.

[0131] The image forming apparatus 10 forms an image on a sheet of paper, which is a recording medium. The image forming apparatus 10 is connected to a laminating apparatus 20, and delivers a plurality of sheets of paper having images formed thereon to the laminating apparatus 20 in succession. The laminating device 20 performs laminating processing on the paper on which the image has been formed by the image forming device 10 .

[0132] <Image forming device> The image forming apparatus is preferably a four-cycle image forming apparatus configured with four color developing devices for yellow, magenta, cyan, and black and one electrophotographic photosensitive member, or may be a tandem image forming apparatus configured with four color developing devices for yellow, magenta, cyan, and black and four electrophotographic photosensitive members, one for each color.

[0133] The image forming apparatus 10 shown in FIG. 3 includes an image processing section 30, an image forming section 40, a paper conveying section 50, a fixing device 60, and an image reading section .

[0134] Image forming section 40 has image forming units 41Y, 41M, 41C, and 41K that form images using toner of each color: Y (yellow), M (magenta), C (cyan), and K (black). These units all have the same configuration except for the toner they contain, so hereinafter, the symbols representing the colors may be omitted. Image forming section 40 also has an intermediate transfer unit 42 and a secondary transfer unit 43. These correspond to transfer devices.

[0135] The image forming unit 41 includes an exposure device 411, a developing device 412, an electrophotographic photosensitive member (image carrier) 413, a charging device 414, and a drum cleaning device 415. The charging device 414 is, for example, a corona charger. The charging device 414 may be a contact charging device that charges the electrophotographic photosensitive member 413 by bringing a contact charging member such as a charging roller, a charging brush, or a charging blade into contact with the electrophotographic photosensitive member 413 . The exposure device 411 includes, for example, a semiconductor laser as a light source, and a light deflection device (polygon motor) that irradiates the electrophotographic photosensitive member 413 with laser light corresponding to an image to be formed. The electrophotographic photoreceptor 413 is a negatively charged organic photoreceptor having photoconductivity. The electrophotographic photoreceptor 413 is charged by a charging device 414.

[0136] Developing device 412 is a two-component developing device. Developing device 412 has, for example, a developing container that stores a two-component developer, a developing roller (magnetic roller) that is rotatably arranged at the opening of the developing container, a partition that separates the inside of the developing container so that the two-component developer can communicate with each other, a transport roller that transports the two-component developer on the opening side of the developing container toward the developing roller, and a stirring roller that stirs the two-component developer in the developing container. The developer container contains, for example, a two-component developer.

[0137] The intermediate transfer unit 42 includes an intermediate transfer belt (intermediate transfer member) 421, a primary transfer roller 422 that presses the intermediate transfer belt 421 against the electrophotographic photosensitive member 413, a plurality of support rollers 423 including a backup roller 423A, and a belt cleaning device 426. Intermediate transfer belt 421 is looped and stretched around a plurality of support rollers 423. When at least one drive roller among the plurality of support rollers 423 rotates, intermediate transfer belt 421 runs in the direction of arrow A at a constant speed.

[0138] The belt cleaning device 426 has an elastic member 426a. The elastic member 426a comes into contact with the intermediate transfer belt 421 after the secondary transfer, and removes any deposits on the surface of the intermediate transfer belt 421. The elastic member 426a is made of an elastic body, and includes a cleaning blade, a brush, and the like.

[0139] The secondary transfer unit 43 has an endless secondary transfer belt 432 and a plurality of support rollers 431 including a secondary transfer roller 431A. The secondary transfer belt 432 is stretched by the secondary transfer roller 431A and the support rollers 431 in a loop shape.

[0140] The fixing device 60 has, for example, a fixing roller 62, an endless heating belt 64 that covers the outer peripheral surface of the fixing roller 62 and heats and melts the toner that forms the toner image on the paper S, and a pressure roller 63 that presses the paper S against the fixing roller 62 and heating belt 64. The paper S corresponds to a recording medium.

[0141] The image forming apparatus 10 further includes an image reading unit 70, an image processing unit 30, and a paper transport unit 50. The image reading unit 70 includes a paper feeder 71 and a scanner 72 . The paper transport section 50 includes a paper feed section 51 , a paper discharge section 52 , and a transport path section 53 . The three paper feed tray units 51a to 51c that make up the paper feed section 51 store paper sheets S (standard paper sheets, special paper sheets) that are identified based on basis weight, size, etc., according to preset types. The transport path section 53 has a plurality of transport roller pairs such as a registration roller pair 53a.

[0142] The formation of an image by the image forming apparatus 10 will be described. The scanner 72 optically scans and reads the document D on the contact glass. The light reflected from the document D is read by the CCD sensor 72a and becomes input image data. The input image data is subjected to predetermined image processing in the image processing unit 30 and sent to the exposure device 411.

[0143] The electrophotographic photosensitive member 413 rotates at a constant peripheral speed. The charging device 414 uniformly charges the surface of the electrophotographic photosensitive member 413 to a negative polarity. In the exposure device 411, a polygon mirror of a polygon motor rotates at high speed, and laser light corresponding to input image data of each color component is developed along the axial direction of the electrophotographic photosensitive member 413 and irradiated along the axial direction onto the outer circumferential surface of the electrophotographic photosensitive member 413. In this way, an electrostatic latent image is formed on the surface of the electrophotographic photosensitive member 413.

[0144] In the developing device 412, the toner base particles are charged by stirring and transporting the two-component developer in the developing container, and the two-component developer is transported to the developing roller, which forms a magnetic brush on the surface of the developing roller. The charged toner base particles electrostatically adhere from the magnetic brush to the electrostatic latent image on the electrophotographic photosensitive member 413. In this way, the electrostatic latent image on the surface of the electrophotographic photosensitive member 413 is visualized, and a toner image corresponding to the electrostatic latent image is formed on the surface of the electrophotographic photosensitive member 413.

[0145] The toner image on the surface of the electrophotographic photosensitive member 413 is transferred to an intermediate transfer belt 421 by an intermediate transfer unit 42. Residual toner remaining on the surface of the electrophotographic photosensitive member 413 after transfer is removed by a drum cleaning device 415 having a drum cleaning blade that comes into sliding contact with the surface of the electrophotographic photosensitive member 413.

[0146] The primary transfer roller 422 presses the intermediate transfer belt 421 against the electrophotographic photosensitive member 413, thereby forming a primary transfer nip for each electrophotographic photosensitive member between the electrophotographic photosensitive member 413 and the intermediate transfer belt 421. In the primary transfer nip, toner images of each color are transferred onto the intermediate transfer belt 421 in order, superimposed on one another.

[0147] Meanwhile, secondary transfer roller 431A is pressed against backup roller 423A via intermediate transfer belt 421 and secondary transfer belt 432. As a result, a secondary transfer nip is formed by intermediate transfer belt 421 and secondary transfer belt 432. Paper S passes through the secondary transfer nip. The sheet S is transported to the secondary transfer nip (adhesion portion) by the sheet transport section 50. Correction of the skew of the sheet S and adjustment of the transport timing are performed by a registration roller section in which a pair of registration rollers 53a is arranged.

[0148] When the paper S is transported to the secondary transfer nip, a transfer bias is applied to the secondary transfer roller 431A. By applying this transfer bias, the toner image carried on the intermediate transfer belt 421 is transferred to the paper S (a process of adhering the toner for developing an electrostatic latent image to the recording medium). The paper S onto which the toner image has been transferred is transported by the secondary transfer belt 432 toward the fixing device 60.

[0149] After the secondary transfer, deposits such as residual toner remaining on the surface of intermediate transfer belt 421 are removed by belt cleaning device 426, which has a cleaning blade that slides against the surface of intermediate transfer belt 421. In this case, since the intermediate transfer body described above is used as the intermediate transfer belt, dynamic friction can be reduced over time.

[0150] Fixing device 60 forms a fixing nip by sandwiching heating belt 64 between rotating fixing roller 62 and pressure roller 63, and heats and presses conveyed paper S in the fixing nip. In this way, the toner image is fixed to paper S (a process of fixing toner for developing an electrostatic latent image to a recording medium). Paper S with the fixed toner image is discharged outside the machine by paper discharge section 52 equipped with paper discharge rollers 52a.

[0151] In this embodiment, the fixing of the toner image on the paper S may be performed in two stages. That is, the image forming apparatus 10 may have two different fixing devices 60, and the fixing may be performed successively by these two fixing devices 60. Specifically, the second-stage fixing device 60 may apply heat and pressure to the toner image heated by the first-stage fixing device 60 before the toner image is completely cooled. This allows the toner image to be heated sufficiently and for a longer period of time, thereby allowing the C16-35 saturated compound to be sufficiently precipitated from the toner base particles and further improving the releasability from the second-stage fixing device 60.

[0152] The second stage of fixing may be performed immediately after the first stage of fixing, or, for example, the paper S may be turned over and another image may be attached and fixed to the back side, and then the paper S may be turned over again and the second stage of fixing may be performed on the front side. In this case, it is preferable to turn the paper S over again and perform the second stage of fixing on the back side as well. Fixation may be carried out in stages from the third stage onwards.

[0153] <Laminating device> FIG. 4 is a schematic diagram showing a laminating device. The laminating device 20 is configured to include a superposing section 22, a laminating section 23, a separating section 24, a conveying section 26, and the like.

[0154] As shown in FIGS. 3 and 4, the overlapping unit 22 is provided upstream of the laminating unit 23 on the paper transport path. The overlapping unit 22 overlaps the leading and trailing edges of the sheets of paper conveyed from the paper discharge unit of the image forming apparatus 10. Specifically, the overlapping unit 22 overlaps the trailing edge of a preceding sheet by a predetermined amount on top of the leading edge of a succeeding sheet, and conveys the sheets in a continuous band. For example, as shown in FIG. 4, the overlapping unit 22 conveys each of the sheets S1 to S3 so that the trailing edge of the sheet S1 slightly overlaps the leading edge of the sheet S2, and so that the trailing edge of the sheet S2 slightly overlaps the leading edge of the sheet S3.

[0155] The laminating unit 23 performs laminating processing on the plurality of sheets of paper that are conveyed. The laminating unit 23 performs laminating processing by overlaying a laminating film F having an adhesive layer on the plurality of sheets of paper. The laminating unit 23 continuously attaches the laminating film F to the surface (front side) of the sheets of paper that have been superimposed by the superimposing unit 22, on which an image has been formed by the image forming device 10. In other words, the laminating unit 23 performs laminating processing on only one side of the sheets of paper. Here, laminating processing is performed on only one side of the sheets of paper, but laminating processing may also be performed on both sides of the sheets of paper. The laminating section 23 is configured to include a film roll 231, a bonding section 232, a laminating fixing section 233, and the like.

[0156] The film roll 231 is a roll of laminate film F, which is made up of a transparent resin film layer and an adhesive layer. A heat-melting adhesive is applied to the side of the laminate film F that comes into contact with the paper, forming an adhesive layer. The laminate film F is transported from the film roll 231 to the nip portion of the laminating section 232 .

[0157] The laminating unit 232 is equipped with a pair of rollers, and sandwiches the paper and the laminate film F in a nip formed by the pair of rollers, thereby adhering the adhesive layer of the laminate film F to the surface of the paper. This bonds the paper and the laminate film F together. The overlapping unit 22 overlaps the leading and trailing ends of the continuously transported paper sheets, thereby preventing the adhesive applied to the film F from coming into contact with anything other than the paper sheets on the path following the laminating unit 232.

[0158] The laminating and fixing unit 233 includes a heating roller 233a and a pressure roller 233b. The laminating and fixing unit 233 applies heat and pressure to the paper and film F that have been bonded together by the bonding unit 232, thereby fixing the laminating film F to the paper. The heating roller 233a has a built-in halogen heater or the like, and functions as a heating section that heats the laminate film F and the paper in a superposed state. The pressure roller 233b is pressed against the heating roller 233a by being urged upward by an urging member (not shown) such as a spring, and a nip portion is formed where the heating roller 233a and the pressure roller 233b are in surface contact with each other. The materials of the heating roller 233a and the pressure roller 233b are preferably metal, resin, etc. The resin may be rubber such as silicone rubber. The heating roller 233a and the pressure roller 233b may also have a rubber surface layer formed on a metal base. The heating roller 233a and pressure roller 233b melt the adhesive layer of the laminate film F, and the melted adhesive layer adheres to the surface of the paper by thermocompression. The lamination process is preferably carried out within a range of 100 to 200° C. In other words, the heating temperature by the heating roller 233a is preferably set within the above range. In the lamination process, the pressure applied to the paper is preferably within the range of 0.05 to 10 MP, that is, the pressure applied to the laminate film by the pressure roller is preferably within the above range.

[0159] The separating section 24 inserts a cutting blade between the papers (sheets) superposed by the superposing section 22 to cut only the film F, thereby separating the papers from one another.

[0160] Conveying section 26 is made up of multiple roller pairs and transports the paper transported from image forming device 10 within laminating device 20. When laminating processing is to be performed on the paper, conveying section 26 transports the paper via conveying path 261 to superposing section 22, laminating section 23, and separating section 24 in that order, and discharges the laminated paper to the outside. When laminating processing is not to be performed on the paper, conveying section 26 transports the paper via conveying path 262 that does not pass through superposing section 22, laminating section 23, and separating section 24.

[0161] The above-described apparatus configuration and image forming method are exemplary embodiments for carrying out the present invention, and the present invention is not limited to these. [Example]

[0162] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the following examples, unless otherwise specified, operations were carried out at room temperature (25°C). Furthermore, unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass," respectively.

[0163] 1. Prepare ingredients <Saturated hydrocarbon compounds S with carbon atoms of 16 to 35> Saturated hydrocarbons having 20 carbon atoms, 26 carbon atoms, 30 carbon atoms, and 34 carbon atoms (manufactured by GL Sciences Inc.) were dispensed in a mass ratio of 20:30:30:20 and melt-mixed at 80°C. The mixture was then cooled and solidified to obtain a saturated hydrocarbon compound S having a carbon number of 16 to 35.

[0164] <Release agent> (Release agent 1 (microcrystalline wax)) A microcrystalline wax with a melting point of 84°C was prepared by solvent crystallization and filtration of the residual oil from vacuum distillation. Molecular distillation was repeated until the average carbon number reached 41 and components with carbon numbers of 16 to 35 were no longer detectable, yielding a microcrystalline wax for use as a release agent. Molecular distillation was performed at a temperature of 240°C and a pressure of 0.2 Pa to remove low molecular weight components, followed by removal of other components at a temperature of 400°C and a pressure of 0.2 Pa. The carbon number was qualitatively analyzed by GC-MS and quantitatively detected by GC-FID. The weight-average molecular weight of the resulting microcrystalline wax was 710, the melting point was 78°C, and the carbon number was 52.

[0165] The weight-average molecular weight of the microcrystalline wax was measured by gel permeation chromatography (GPC), for example, using a Shimadzu RID-6A column (Tosoh TSK-GEL column, tetrahydrofuran (THF) solvent, and a column temperature of 40°C) and a calibration curve prepared using polystyrene standard samples. The melting point of the microcrystalline wax was measured by DSC. Specifically, 5 mg of the sample was sealed in an aluminum pan and set in the sample holder of a thermal analyzer, Diamond DSC (manufactured by PerkinElmer). The measurement was carried out under the following conditions: a heating process in which the sample was kept isothermal at 100°C for 1 minute, a cooling process in which the sample was cooled from 100°C to 0°C at a cooling rate of 0.1°C / min, and a heating process similar to that described above. The temperature at the top of the endothermic peak in the endothermic curve obtained during the second heating was measured as the melting point (Tm). The melting points of the following release agents 2 and 3 were also measured in the same manner as for release agent 1.

[0166] (Release agent 2 (ester wax)) Commercially available behenyl behenate was used as release agent 2 (melting point 75°C).

[0167] (Release agent 3 (paraffin wax) A commercially available paraffin wax, HNP-11 (manufactured by Nippon Seiro Co., Ltd.) (melting point 67.4° C., weight average molecular weight 420, carbon number 29), was used as the paraffin wax serving as the mold release agent 3.

[0168] <Binder resin> (Binder resin 1 (amorphous polyester) Terephthalic acid: 55.6 parts by mass Bisphenol A propylene oxide adduct (BPA-PO) : 28.8 parts by mass Propanediol: 15.5 parts by mass Tin 2-ethylhexanoate (esterification catalyst): 0.50 parts by mass The above materials were placed in a reactor equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. The atmosphere in the reactor was then replaced with nitrogen gas, and the temperature was gradually increased while stirring. The materials were reacted at 140°C for 3 hours while stirring.

[0169] Next, the pressure in the reaction vessel was reduced to 8.3 kPa, and the mixture was heated to 200°C with stirring and reacted for 4 hours. Thereafter, the pressure in the reaction vessel was reduced to 5 kPa or less again, and the mixture was reacted at 200°C for 3 hours, to obtain Binder Resin 1.

[0170] (Binder resin 2 (crystalline polyester)) ·Adipic acid: 40.9 parts by mass 1,5-pentanediol: 59.1 parts by mass Tin 2-ethylhexanoate: 0.50 parts by mass The above materials were placed in a reactor equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. The atmosphere in the reactor was then replaced with nitrogen gas, and the temperature was gradually increased while stirring. The materials were reacted at 140°C for 3 hours while stirring.

[0171] Next, the pressure inside the reaction vessel was reduced to 8.3 kPa, and the temperature was raised to 200°C while stirring, and the mixture was reacted for 1 hour to obtain binder resin 2. The melting point of binder resin 2 was 76°C.

[0172] The melting point was measured by DSC. Specifically, 5 mg of the sample was sealed in an aluminum pan and set in the sample holder of a thermal analyzer Diamond DSC (manufactured by PerkinElmer). The measurement was carried out under the following conditions: a heating process in which the sample was kept isothermal at 100°C for 1 minute, a cooling process in which the sample was cooled from 100°C to 0°C at a cooling rate of 0.1°C / min, and a heating process similar to the above. The temperature at the top of the endothermic peak in the endothermic curve obtained during the second heating was measured as the melting point.

[0173] (Polyester resin particle dispersion for shell) 100 parts by weight of binder resin 1 was coarsely pulverized using a cutter mill (VM-16, manufactured by Makino Sangyo Co., Ltd.) to prepare a coarse powder with a particle size of 500 to 800 μm. Next, 100 parts by weight of the coarse powder was added to an aqueous solution prepared by dissolving 1 part by weight of a polymer dispersant (trade name: Joncryl 51, manufactured by BASF) and 1 part by weight of sodium dodecylbenzenesulfonate in 490 parts by weight of deionized water, to prepare an aqueous dispersion of the coarse powder. This aqueous dispersion was pretreated by passing it through a nozzle with an inner diameter of 0.3 mm under a pressure of 50 MPa, and the particle size of the coarse powder in the aqueous dispersion was adjusted to 100 μm or less. The volume average particle size of the coarse powder was measured using a laser diffraction / scattering particle size distribution (particle size distribution) analyzer (LA-960, manufactured by Horiba, Ltd.).

[0174] The obtained dispersion of the coarse powder was heated to 130°C and supplied under a pressure of 150 MPa from a pressure-resistant pipe to a pressure-resistant nozzle attached to the outlet of the pressure-resistant pipe. The pressure-resistant nozzle was a 0.5 cm long, pressure-resistant multiple nozzle with two liquid flow holes, each 0.143 mm in diameter, formed so as to be approximately parallel in the longitudinal direction of the nozzle.

[0175] The temperature of the dispersion at the nozzle inlet was 130°C, and the back pressure was 210 MPa. The temperature of the dispersion at the nozzle outlet was 170°C, and the back pressure was 42 MPa. The aqueous slurry (dispersion) discharged from the pressure-resistant nozzle was introduced into a coiled tube cooler connected to the outlet of the pressure-resistant nozzle and cooled. The temperature of the dispersion at the cooler outlet was 20°C, and the back pressure was 1 MPa. The dispersion discharged from the cooler outlet was introduced into a multistage pressure-reducing device connected to the cooler outlet, and reduced in pressure. The multistage pressure-reducing device was composed of five metal pipe-shaped members with different inner diameters connected by ring-shaped seals. The inner diameters of the five metal pipe-shaped members were changed in stages from 0.5 mm to 1 mm. The dispersion discharged from the multistage pressure-reducing device was a dispersion of shell polyester resin microparticles with a volume average particle size of 45 to 155 nm.

[0176] 2. Preparation of toner base particles <Toner base particles A> Binder resin 1 (amorphous polyester): 100.0 parts by mass Release agent 1 (microcrystalline wax): 5.00 parts by mass Saturated hydrocarbon compounds S with carbon atoms between 16 and 35: 0.000111 parts by mass Copper phthalocyanine (CI Pigment Blue 15:3): 6.00 parts by mass The above materials were put into a Henschel mixer (Mitsui Mining Co., Ltd., FM-75 type) and rotated at a speed of 20 s -1 The mixture was mixed under the conditions of 1000 kneading time and 5 min. Thereafter, these were kneaded using a twin-screw kneader (manufactured by Ikegai Corporation, PCM-30 model) set at a temperature of 150°C. The obtained kneaded product was cooled and coarsely crushed to 1 mm or less using a hammer mill to obtain a coarsely crushed product. The obtained coarsely crushed product was finely crushed using a mechanical crusher (manufactured by Turbo Kogyo Co., Ltd., T-250). Furthermore, a classifying rotor rotation speed of 130 s was used in a classifying device (manufactured by Hosokawa Micron Corporation, Faculty F-300). -1 , distributed rotor rotation speed 120s -1 Classification was carried out as follows.

[0177] The classified particles were subjected to a spheronization treatment using the spheronization treatment device shown in Figure 1. The particles were heated to a temperature of 35°C in a gas phase and subjected to continuous impact force for 5 minutes to undergo the spheronization treatment. This resulted in toner base particles A. The resulting toner base particles A had a volume average particle size of 6.2 μm. The volume average particle size was measured using a Coulter Multisizer 3 manufactured by Beckman Coulter. The volume average particle sizes of the following toner base particles were also measured in the same manner.

[0178] <Toner base particles B> Toner base particles B were prepared in the same manner as toner base particles A, except that the amount of saturated hydrocarbon compound S having a carbon number of 16 to 35 was changed to 0.0555 parts by mass. The volume average particle size of toner base particles B was 6.0 μm.

[0179] <Toner base particles C> Toner base particles C were prepared in the same manner as toner base particles B, except that the release agent used was changed to release agent 2. The volume average particle size of toner base particles C was 6.0 μm.

[0180] <Toner base particles D> Toner base particles D were prepared in the same manner as toner base particles B, except that the temperature in the gas phase during the spheronization treatment was changed to 30°C and the impact time was changed to 10 minutes. The volume average particle size of toner base particles D was 5.9 μm.

[0181] <Toner base particles E> An aqueous slurry was prepared by mixing 100 parts by weight of toner base particles B and 10 parts by weight of a dispersion of polyester resin particles for shells into an aqueous solution prepared by dissolving 1 part by weight of sodium dodecylbenzenesulfonate in 500 parts by weight of deionized water. While stirring the aqueous slurry using a turbine blade, an aqueous magnesium sulfate solution (concentration: 0.1% by weight) was added dropwise to the aqueous slurry. After that, this mixture was stirred for 1 hour, and aggregation of polyester resin (amorphous) fine particles was observed on the surface of the core particles, that is, toner base particles B. The aqueous slurry containing these aggregated particles was stirred at a temperature of 81°C for 2 hours, and an aqueous slurry in which toner base particles E were dispersed was obtained. The toner base particles isolated from the aqueous slurry by filtration were washed three times with pure water (conductivity 0.5 μS / cm) and then dried in a vacuum dryer to obtain toner base particles E. The volume average particle size of the toner base particles E was 6.3 μm.

[0182] <Toner base particles F> Toner base particles F were prepared in the same manner as toner base particles A, except that the materials used were changed to the following materials. Binder resin 1 (amorphous polyester): 90.0 parts by mass Binder resin 2 (crystalline polyester): 10.0 parts by mass Release agent 1 (microcrystalline wax): 5.00 parts by mass Saturated hydrocarbon compounds S with carbon atoms between 16 and 35: 0.0555 parts by mass Copper phthalocyanine (CI Pigment Blue 15:3): 6.00 parts by mass The volume average particle size of the toner base particles F was 6.0 μm.

[0183] <Toner base particles G> Toner base particles G were prepared in the same manner as toner base particles A, except that the amount of saturated hydrocarbon compound S having a carbon number of 16 to 35 was changed to 0.1107 parts by mass. The volume average particle size of toner base particles G was 6.0 μm.

[0184] <Toner base particles H> In the production of toner base particles F, the processing time during the spheronization process was optimally adjusted to obtain toner base particles H having a volume average particle size of 7.5 μm.

[0185] <Toner base particles I> In the preparation of toner base particles F, the processing time during the spheronization process was optimally adjusted to obtain toner base particles I having a volume average particle size of 9.0 μm.

[0186] <Toner base particles J> Toner base particles J having a volume average particle size of 6.0 μm were obtained in the same manner as in the preparation of toner base particles F, except that the content of the release agent was changed to be as shown in the table below.

[0187] <Toner base particles K> Toner base particles K having a volume average particle size of 6.0 μm were obtained in the same manner as in the preparation of toner base particles F, except that the content of the release agent was changed to be as shown in the table below.

[0188] <Toner base particles L> Toner base particles L were prepared in the same manner as toner base particles A, except that in the preparation of toner base particles A, release agent 1 was changed to release agent 3 and the amount of saturated hydrocarbon compound S having a carbon number of 16 to 35 was changed as shown in the table below. The volume average particle size of toner base particles L was 6.0 μm.

[0189] <Toner base particles R> Toner base particles R were prepared in the same manner as toner base particles A, except that the amount of saturated hydrocarbon compound S having a carbon number of 16 to 35 was changed to 0.1134 parts by mass in the preparation of toner base particles A. The volume average particle size of toner base particles R was 6.1 μm.

[0190] <Toner base particles Z> Toner base particles Z were prepared in the same manner as toner base particles A, except that in the preparation of toner base particles A, release agent 1 was changed to release agent 3 and the amount of saturated hydrocarbon compound S having a carbon number of 16 to 35 was changed as shown in the table below. The volume average particle size of toner base particles Z was 6.0 μm.

[0191] 3. Toner Preparation <Toner 1> 100 parts by mass of toner base particles A were mixed with the silica fine particles and titanium oxide fine particles shown below in a Henschel mixer (FM-75, manufactured by Mitsui Miike Chemical Engineering Co., Ltd.) at a rotation speed of 30 s -1 The mixture was mixed for 10 minutes, and a toner 1 was obtained. Hydrophobic silica particles (BET specific surface area: 200 m) hydrophobized with hexamethyldisilazane 2 / g): 1.0 parts by mass Titanium oxide particles (BET specific surface area: 80 m) surface-treated with isobutyltrimethoxysilane 2 / g): 1.0 parts by mass

[0192] <Toners 2 to 6, 8 to 13, 20 and 21> Toners 2 to 6, 8 to 13, 20 and 21 were obtained in the same manner as in the preparation of Toner 1, except that the toner base particles used were changed to Toner base particles 2 to 6, 8 to 13, 20 and 21, respectively.

[0193] <Toner 7> 100 parts by mass of toner base particles B, silica fine particles, titanium oxide fine particles, and strontium titanate shown below were mixed in a Henschel mixer (FM-75, manufactured by Mitsui Miike Chemical Engineering Co., Ltd.) at a rotation speed of 30 s -1 The mixture was mixed for 10 minutes to obtain Toner 7. Hydrophobic silica particles (BET specific surface area: 200 m) hydrophobized with hexamethyldisilazane 2 / g): 1.0 parts by mass Titanium oxide particles (BET specific surface area: 80 m) surface-treated with isobutyltrimethoxysilane 2 / g): 1.0 parts by mass Strontium titanate (volume average particle size 50 nm): 0.5 parts by mass

[0194] 4. Measurement of the amount of C16-35 saturated compounds Hydrocarbon compounds were extracted from each toner by solid-liquid extraction using n-hexane. At this time, cyclohexyl was added as an internal standard. Unsaturated hydrocarbons were then epoxidized using metachloroperbenzoic acid (mCPBA) in the usual manner, and saturated hydrocarbon compounds were purified and extracted by solid-phase extraction using silver nitrate silica gel as the solid phase. GC-FID was performed under the following conditions to quantify C16-35 saturated compounds.

[0195] (GC conditions) Equipment used: Shimadzu GC-2010 Plus Injection volume: 1 μL, saturated hydrocarbon concentration: 500 to 1000 mg / L Guard column: Restek MXT Siltek (10 m x 0.53 mm id) Column: Restek MTX-1 (15 m x 0.25 mm id) x 0.1 μm df) Carrier gas: Helium

[0196] The elution times of n-alkanes (number of carbon atoms: 10, 16, 24, 35, and 50) previously measured under the same conditions were measured. In addition, a blank chromatogram was prepared by injecting only n-hexane into the above-mentioned device.

[0197] By subtracting the blank chromatogram from the chromatogram obtained from each toner, a stable, horizontal, straight baseline was created before and after the peaks derived from saturated hydrocarbon compounds. Perpendicular lines were drawn at the 16 carbon atom and 35 carbon atom peaks, and the area of ​​the chromatogram above the baseline enclosed by these perpendicular lines was calculated. Peaks that were confirmed not to be saturated hydrocarbon compounds were excluded from the calculation. The mass of saturated hydrocarbon compounds with 16 to 35 carbon atoms was calculated from the ratio of this area to the area of ​​bicyclohexyl added as an internal standard. This mass was then divided by the mass of the toner to determine the amount of C16-35 saturated compounds in the toner.

[0198] 5. Preparation of Developer 100 parts by mass of ferrite particles (volume-based median diameter: 50 μm (manufactured by Powder Tech Co., Ltd.)) and 4 parts by mass of methyl methacrylate-cyclohexyl methacrylate copolymer resin (volume-based median diameter of primary particles: 85 nm) were placed in a high-speed mixer with horizontal mixing blades and mixed for 15 minutes at a mixing blade peripheral speed of 8 m / s and a temperature of 30°C. The mixture was then heated to 120°C and stirred for 4 hours. The mixture was then cooled, and fragments of the methyl methacrylate-cyclohexyl methacrylate copolymer resin were removed using a 200-mesh sieve to produce a resin-coated carrier. This resin-coated carrier was mixed with each of the above toners so that the toner concentration was 7% by mass relative to the total mass of the toner and carrier, to prepare two-component developers 1 to 8, 20, and 21, respectively.

[0199] 6. Evaluation <Adhesion of the edges of the laminate film> The prepared developers were loaded sequentially into a modified developing device. Image formation was carried out under the following conditions 1 and 2 under ambient conditions of 20°C and 55% RH. The developing device used was a commercially available color multifunction printer "bizhub PRO C6500 (manufactured by Konica Minolta)" modified to allow for free setting of the fixing temperature, toner adhesion amount, and system speed. Regarding the positional relationship between the upper fixing roller 62 and the lower pressure roller 63 under conditions 1 and 2, see Figure 3. Furthermore, all toner images were fixed in one step.

[0200] (Condition 1) Paper type: A4 size NPI 64.0 g / m 2 (Made by Nippon Paper Industries Co., Ltd.), thickness as shown in the table below Adhesion amount: 8g / m 2 Fixing temperature: Temperature of the upper fixing roller 62: Minimum fixing temperature (150°C) + 20°C Temperature of the lower pressure roller 63: Temperature of the upper fixing roller -20°C Linear speed: 300mm / s (Condition 2) Paper type: A4 size mirror coated platinum paper 256 g / m 2 (Oji Paper Co., Ltd.), thickness as shown in the table below Adhesion amount: 8g / m 2 Fixing temperature: Temperature of the upper fixing roller 62: the above-mentioned minimum fixing temperature (150°C) + 50°C Temperature of the lower pressure roller 63: Temperature of the upper fixing roller -20°C Linear speed: 200mm / s

[0201] Next, the images were laminated on the two types of paper on which the images were created under the above conditions 1 and 2 under the following lamination conditions, and left in an environment of normal temperature and humidity of 20°C and 55% RH for 7 days.

[0202] (Lamination conditions) Equipment: 4-roller laminator "L3250" (Asuka Co., Ltd.) Speed: Speed ​​“3” Laminating film: A4 size Asmix laminating film Pressure applied by pressure roller: 2.5 MPa The thickness of the laminate film and the heating temperature during lamination using a heated roller were as shown in the table below.

[0203] After lamination, the side of the laminated image was dropped six times from a height of 20 cm, and the distance to which the edge of the laminated film had separated or peeled off was measured and the edge adhesion was evaluated according to the following criteria: The distance refers to the farthest point away from the edge of the laminated film. The samples formed under conditions 1 and 2 were evaluated at the same time. The samples formed under conditions 1 and 2 both had the same evaluation results. (standard) AAA: The distance of the edge separation or peeling is less than 1 mm (no practical problem) AA: The distance of the edge separation or peeling is 2 mm or more but less than 5 mm (no practical problem) A: The distance the edge has separated or peeled is 5 mm or more but less than 10 mm (no practical problem) B: The distance the edge has separated or peeled is 10 mm or more (problems in practical use)

[0204] <Bubble formation during lamination> After the lamination process, the number of bubbles in the laminated portion was counted and the generation of bubbles was evaluated according to the following criteria. The evaluation was performed simultaneously for the film formed under condition 1 and the film formed under condition 2. The film formed under condition 1 and the film formed under condition 2 both had the same evaluation results. (standard) AAA: Less than two bubbles found within a 10cm x 10cm area in the laminate AA: 5 to 10 bubbles found within a 10cm x 10cm area in the laminate A: In the laminated area, there are 10 to 20 bubbles within a 10cm x 10cm area. B: 20 ​​or more bubbles found within a 10cm x 10cm area in the laminated area

[0205] [Table 1]

[0206] [Table 2]

[0207] [Table 3]

[0208] In the above table, "release agent content [mass%]" is the content of the release agent in the toner base particles, and "C16-35 saturated compound content [mass%]" is the content of the C16-35 saturated compound in the toner base particles. As shown by the above results, the image forming method of the present invention provides better adhesion at the edge of the laminate film than the comparative example, and also suppresses the generation of bubbles in the laminated portion. [Explanation of symbols]

[0209] 80 Spheronization Processing Device 81 Raw material hopper 82 Stirring motor 83 Ultrasonic Nozzle 84 Collision plate 85 Recycling collector 86 Collection Cyclone 87 Raw material inlet 88 Compressed Air 89 Exhaust outlet T Toner base particles 90 Surface Treatment Equipment 91 Hopper 92 Mixing room 93 nozzle 94 Dispersed Airflow 95 Diffuser 96 Heat Treatment Room 97 Hot air swirling room 98 Cold air supply section 99 Discharge section 1. Image forming system 10 Image forming device 20 Laminating equipment 22 Superimposed section 23 Lamination Department 231 Film Roll 232 Bonding section 233 Laminate fixing section 24 Separation part 26 Conveying section F film 30 Image processing section 40 Image forming unit 41Y, 41M, 41C, 41K Image forming units 42 Intermediate transfer unit 43 Secondary transfer unit 50 Paper transport section 51 Paper feed section 51a, 51b, 51c Paper feed tray units 52 Paper output section 52a Paper ejection roller 53 Conveying path section 53a Registration roller pair 60 Fixing device 62 Fixing roller 63 Pressure Roller 64 Heating Belt 70 Image reading unit 71 Paper feeder 72 Scanner 72a CCD sensor 411 Exposure equipment 412 Developing device 413 Electrophotographic photoreceptor 414 Charging device 415 Drum cleaning device 421 Intermediate transfer belt 422 Primary transfer roller 423, 431 Support roller 423A Backup Roller 426 Belt cleaning device 426a Elastic member 431A Secondary transfer roller 432 Secondary transfer belt D Manuscript S paper

Claims

1. 1. An image forming method comprising: laminating a laminate film on at least one surface of a recording medium on which a toner image has been formed using a toner, and then applying heat and pressure to the laminate film, the toner has toner base particles containing a hydrocarbon compound having 35 or less carbon atoms and a release agent, the release agent contains a hydrocarbon wax; The content of the hydrocarbon compound having 35 or less carbon atoms in the toner base particles is 0.1% by mass or less as measured by gas chromatography. An image forming method comprising:

2. The content of the hydrocarbon wax in the toner base particles is within a range of 0.1 to 50% by mass.

2. The image forming method according to claim 1.

3. In the lamination process, heating is performed within a range of 100 to 200°C.

2. The image forming method according to claim 1.

4. The thickness of the laminate film is in the range of 80 to 250 μm.

2. The image forming method according to claim 1.

5. The thickness of the recording medium is in the range of 50 to 300 μm.

2. The image forming method according to claim 1.

Images