JP2010186122A - Clear toner and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clear toner capable of always stably forming a smooth gloss surface, the toner to be used in a process of forming a gloss surface by supplying the clear toner to the whole surface of a transfer material on which an image is formed, heating and cooling the surface carrying the clear toner, while being in tight contact with a belt. <P>SOLUTION: The clear toner includes a resin obtained from radical polymerizable monomers that include a radical polymerizable monomer, having an acidic group having a valance of at least 2; a resin obtained from radical polymerizable monomers that do not include a radical polymerizable monomer, having an acidic group having a valance of at least 2; a monoester compound expressed by general formula of R<SP>1</SP>-COO-R<SP>2</SP>; and a hydrocarbon compound having a specified structure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a colorless and transparent toner called clear toner used for imparting gloss to an image formed by a known image forming method such as an electrophotographic method, an ink jet method, a printing method, and the like, and the clear toner. The present invention relates to an image forming method including a step of forming a clear toner layer using

  Print images such as photographic images and posters have recently been produced in inkjet and electrophotographic image forming apparatuses in addition to conventional silver halide photographic and gravure printing methods.

  For example, in the field of electrophotographic image forming technology such as copying machines and printers, with the progress of technology such as digitization of exposure systems and toner diameter reduction, 1200 dpi (dpi; per inch (2.54 cm)) This makes it possible to reproduce a minute dot image of the number of dots. Also, a method in which toner images are formed on a plurality of photosensitive drums, the formed toner images are primarily transferred to an intermediate transfer member and superimposed, and the toner image formed on the intermediate transfer member is secondarily transferred to a transfer material. As a result, technology that enables full-color image formation has also been developed. Thus, with the development of image forming technology, full-color images such as photographic images that require high resolution can be produced by these image forming technologies in addition to silver salt photography and conventional printing technologies.

  A photographic image such as a poster often requires a glossy image. For example, when a photographic image is formed using toner, a toner image region fixed on a transfer material such as paper has a certain level of gloss. The white background of things may have a less glossy finish. Such an unbalanced glossy finish impairs the image quality of the printed matter, so countermeasures have been required.

  From such a background, as a technique for eliminating gloss unevenness on an image, a technique for forming an image using a toner having a composition in which a colorant component is removed from an ordinary coloring toner, also called a clear toner or a transparent toner, is examined. It came to be done. Specifically, clear toner is supplied to the entire surface of the transfer material on which the image has been formed, and this is heated and cooled to form a clear toner layer on the entire surface of the image, so that a uniform gloss level with no unevenness is formed on the entire surface of the image. There is a technique for producing a printed matter (see, for example, Patent Document 1). In addition, a technique has been developed in which a glossy printed product can be provided by forming a transparent toner layer on an image formed by a printer or the like using an apparatus that imparts gloss (for example, Patent Document 2). 3).

  This apparatus is connected to an electrophotographic printer or the like, and after a clear toner layer is formed on the entire surface of the image produced by the printer, the clear toner layer is heated with the surface of the clear toner layer being in close contact with the belt member. Melt. Then, the clear toner layer is cooled with the surface of the clear toner layer being in close contact with the belt member, and the clear toner layer is cured, and the printed matter having the clear toner layer cured is peeled off from the belt member, thereby completing a glossy printed matter. To do.

  There is also a full-color image forming technology that can obtain uniform gloss without unevenness by focusing on the difference in physical properties between the toner for image formation and the transparent toner, such as specifying the particle size difference between the color toner and the transparent toner. (For example, refer to Patent Document 4). With these technologies, it is possible to form a glossy surface with a level of smoothness that allows an image to be captured by the action of light on the image surface on which the clear toner layer is formed. It came to be offered to.

  By the way, in the techniques disclosed in Patent Documents 2 and 3, the surface to which the clear toner is supplied is always kept in close contact with the belt member, and heating and cooling are performed in this state. As it goes on, the belt member gradually deteriorates due to the action of heat. As the belt member deteriorates, cracks and scratches occur on the belt surface. When a glossy surface is formed using a belt member that has deteriorated, the unevenness due to cracks or scratches on the belt surface is transferred to the glossy surface on the image. As a result, it becomes impossible to form a uniform glossy surface without unevenness.

Japanese Patent Laid-Open No. 11-7174 JP 2002-341619 A JP 2004-258537 A JP 2007-140037 A

  The present invention is used to form a glossy surface by supplying clear toner to the entire surface of a transfer material on which an image is formed and heating and cooling the clear toner surface in close contact with the belt. An object of the present invention is to provide a clear toner that stably forms the toner. Specifically, the present invention provides a clear toner that does not transfer irregularities onto a glossy surface even if the belt is deteriorated by repeated formation of a glossy surface and cracks or scratches occur on the belt surface to cause irregularities. For the purpose. That is, the present invention provides a clear toner capable of stably forming a glossy surface having high image clarity on the surface of the formed clear toner layer even when the clear toner layer is formed using a deteriorated belt. With the goal.

The present inventor has found that the above-described problem can be solved by any of the configurations described below. That is, the invention described in claim 1
“At least clear toner is supplied to the transfer material on which the image is formed, and the transfer material supplied with clear toner is in close contact with the belt. A clear toner used in an image forming method including a step of forming a clear toner layer,
The clear toner is at least
A resin obtained from a radical polymerizable monomer containing a radical polymerizable monomer having an acidic group having a valence of 2 or more;
A resin obtained from a radical polymerizable monomer that does not contain a radical polymerizable monomer having a divalent or higher acid group;
A monoester compound represented by the following general formula (1);
A clear toner comprising a hydrocarbon compound having at least one of a branched chain structure and a cyclic structure.

General formula (1): R < ¹ > -COO-R < ² >
[Wherein, R ¹ and R ² are each a hydrocarbon group having 13 to 30 carbon atoms, and each may have a substituent, may not have a substituent, or may be the same. It can be different. ]].

The invention described in claim 2
The clear toner according to claim 1, wherein the monoester compound represented by the general formula (1) has a melting point of 39 ° C. or higher and 90 ° C. or lower. ].

The invention according to claim 3
"at least,
Supplying clear toner to a transfer material on which an image is formed;
A step of closely contacting the transfer material supplied with the clear toner to the belt, and heating the clear toner in this state;
A step of cooling the transfer material after heating;
By separating the cooled transfer material from the belt,
An image forming method for forming a clear toner layer on the transfer material,
The clear toner used in the image forming method is at least,
A resin obtained from a radical polymerizable monomer containing a radical polymerizable monomer having an acidic group having a valence of 2 or more;
A resin obtained from a radical polymerizable monomer that does not contain a radical polymerizable monomer having a divalent or higher acid group;
A monoester compound represented by the following general formula (1);
An image forming method comprising a hydrocarbon compound having at least one of a branched chain structure and a cyclic structure.

General formula (1): R < ¹ > -COO-R < ² >
[Wherein, R ¹ and R ² are each a hydrocarbon group having 13 to 30 carbon atoms, and each may have a substituent, may not have a substituent, or may be the same. It can be different. ]].

  In the present invention, when a clear toner is supplied to the entire surface of an image-formed transfer material and the glossy surface is formed by heating and cooling the clear toner in a state of being in close contact with the belt, a belt having irregularities on the surface due to deterioration or the like is provided. A glossy surface with high image clarity can be formed even when used. Specifically, even if the glossy surface is repeatedly formed and adhered to the belt with irregularities due to cracks, scratches, etc. to form the glossy surface, the irregularities on the belt surface are not transferred to the glossy surface, and light is emitted. It has become possible to stably produce printed matter having a reflective surface with a high image clarity.

FIG. 3 is a schematic diagram of a gloss imparting apparatus capable of forming a glossy surface on the entire image surface formed on a transfer material with clear toner. 2 is a cross-sectional configuration diagram of an image forming apparatus that forms a full-color toner image and also forms a clear toner layer on the entire surface of the full-color toner image. FIG. FIG. 3 is a schematic diagram illustrating an example of an apparatus in which a gloss imparting apparatus is attached to the image forming apparatus of FIG. 2. FIG. 3 is a schematic diagram illustrating an example of an apparatus in which a gloss imparting apparatus is attached to the image forming apparatus of FIG. 2. It is a schematic diagram which shows the principle of the image clarity C value measurement by TM type image clarity measuring apparatus.

  The present invention relates to a clear toner that is supplied to the entire surface of an image-formed transfer material and used to form a glossy surface by heating and cooling in a state of being in close contact with a belt.

  Even if the inventor adheres a belt with irregularities such as cracks and scratches to form a clear toner layer, the irregularity on the belt surface is not transferred, and the image property that the image is reflected on the surface by the action of light The development of a clear toner capable of forming a clear toner layer having a high gloss surface was investigated. Initially, the present inventor considered the development of a clear toner that suppresses deterioration of the belt surface. In other words, by developing a clear toner that melts at a low heating temperature and solidifies without significantly reducing the cooling temperature, it deteriorates so that cracks and scratches do not occur on the belt surface even when the glossy surface is repeatedly formed. I thought to suppress this.

  The present inventor has developed a clear toner having such characteristics. However, as the glossy surface was repeatedly formed, the inventor noticed that the clear toner adhered to the belt surface and caused a slight offset phenomenon to cause contamination. . In addition, the present inventor has realized that a certain amount of clear toner is necessary to produce a printed image with high image clarity and glossiness, and by increasing the adhesion between the clear toners, high glossiness is achieved. We thought that an image could be obtained and the occurrence of offset could be eliminated.

  The inventor of the present invention provides a resin obtained from a radical polymerizable monomer containing a radical polymerizable monomer having a divalent or higher acid group as a constituent resin of a clear toner, and a radical polymerizable monomer having a divalent or higher acid group. It has been found that by including a resin obtained from a radically polymerizable monomer not included, an image having a glossy surface with high image clarity can be obtained, and contamination due to an offset phenomenon does not occur.

  A resin obtained from a radical polymerizable monomer containing a radical polymerizable monomer having a divalent or higher acidic group, and a resin obtained from a radical polymerizable monomer not containing a divalent or higher acidic group having a radical polymerizable monomer; The reason why a smooth clear toner surface having a high glossiness is formed by the constituent resin containing is considered as follows.

  That is, a resin obtained from a radical polymerizable monomer containing a radical polymerizable monomer having a divalent or higher acidic group has a property of slowly aggregating. When this resin is allowed to coexist with a resin obtained from a radically polymerizable monomer that does not contain a radically polymerizable monomer having a divalent or higher acid group, the two resins have a difference in aggregation rate and are also hydrophilic. Due to the difference, the resin obtained from the radically polymerizable monomer containing the radically polymerizable monomer having a divalent or higher valent acid group is likely to gather on the surface side of the clear toner particles.

  A resin component obtained from a radical polymerizable monomer containing a radical polymerizable monomer having an acidic group having a valence of 2 or more forms a state where the resin component is exposed on the surface of the clear toner, and the molecular chains constituting the resin are high-dimensional. It is considered that an entanglement (a high-density aggregate structure) is formed. The molecular chain high-density aggregation structure on the surface of the clear toner particles is easily entangled with each other even between the clear toner particles, promotes adhesion between the clear toner particles and forms a high-density aggregation structure on the entire surface of the clear toner layer. It is considered that the unevenness is difficult to transfer.

  In the present invention, the clear toner contains a monoester compound represented by the general formula (1) described later and a hydrocarbon compound having at least one of a branched chain structure and a cyclic structure described later. Is. In the present invention, it is also conceivable that the unevenness on the belt surface is difficult to be transferred by the clear toner surface by the combined use of the monoester compound and the hydrocarbon compound. That is, the adhesive action between the clear toner surface and the belt surface is suppressed by the releasing action of the monoester compound represented by the general formula (1), and even if the belt surface has irregularities, the irregularities on the belt surface are cleared. It is thought that transfer to the toner surface becomes difficult.

  In addition, the monoester compound has a property of being easily crystallized, but the presence of a hydrocarbon compound having at least one of a branched chain structure and a cyclic structure can make the degree of crystallization of the monoester compound uniform. It is thought that it became. As described above, the combination of the monoester compound and the hydrocarbon compound does not transfer the unevenness of the belt surface to the clear toner surface, and the specific hydrocarbon compound controls the degree of crystallization of the monoester compound. Conceivable.

  For this reason, in the present invention, it is considered that an image having a glossy surface with high image clarity can be obtained even when a transfer belt having irregularities such as cracks and scratches is used.

  Hereinafter, the present invention will be described in detail. The “clear toner” as used in the present invention is a toner particle that does not contain a colorant (for example, a color pigment, a coloring dye, black carbon particles, black magnetic powder, etc.) that shows coloration by the action of light absorption or light scattering. That is. The clear toner referred to in the present invention is usually colorless and transparent. However, depending on the type and amount of the binder resin, wax, and external additive constituting the clear toner, the transparency may be slightly lower. It is virtually colorless and transparent.

  In addition, the “image” in the present invention refers to a medium that provides information to the user, such as a character image or an image. In other words, not only the area where toner, ink, etc. are present on the transfer material, but also the area where toner, ink, etc., which is called white background is not present, can be provided to the user. It is what. The “image” in the present invention includes both those having a clear toner layer and those having no clear toner layer. Further, the present invention does not particularly limit the method for producing an image before forming the clear toner layer, and it is produced by a known image forming method such as an electrophotographic method, a printing method, an ink jet method, a silver salt photographic method, or the like. It becomes the target.

  First, the resin constituting the clear toner according to the present invention will be described.

  The resin constituting the clear toner according to the present invention includes a resin obtained from a radical polymerizable monomer containing a radical polymerizable monomer having a divalent or higher acid group and a radical polymerizable monomer having a divalent or higher acid group. The resin obtained from the radically polymerizable monomer which does not contain is included.

  The “radical polymerizable monomer having an acid group having two or more valences” used for the production of the resin constituting the clear toner according to the present invention is, for example, an ion showing acidity such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group It is a vinyl monomer having two or more sex dissociation groups in the side chain. In the present invention, among these acidic dissociable groups, those having two or more carboxyl groups as side chains are preferred. Examples of the vinyl monomer having two or more carboxyl groups in the side chain include itaconic acid, maleic acid, and fumaric acid.

  The “radical polymerizable monomer that does not include a radical polymerizable monomer having a divalent or higher acidic group” used for preparing the resin constituting the clear toner according to the present invention includes, for example, “monovalent acidic group”. And "a known vinyl monomer having no acidic group in the side chain".

  The “radical polymerizable monomer having a monovalent acidic group” is, for example, a vinyl monomer having one ionic dissociation group showing acidity such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group as a side chain. It is.

  Examples of those having a carboxyl group in the side chain include acrylic acid, methacrylic acid, cinnamic acid and the like and those having an alkyl ester group of these carboxylic acids in the side chain. Examples of those having a sulfonic acid group include styrenesulfonic acid, allylsulfosuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, and alkyl ester compounds of these sulfonic acids. Furthermore, examples of the phosphoric acid group include acid phosphooxyethyl methacrylate.

  Examples of the “known vinyl monomer having no acidic group in the side chain” include the vinyl monomers described below. Specific examples of vinyl polymerizable monomers are shown below.

(1) Styrene or styrene derivatives Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, etc. (2) Methacrylate derivatives Methyl methacrylate, methacryl Ethyl acetate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethyl methacrylate Aminoethyl, dimethylaminoethyl methacrylate, etc. (3) Acrylic acid ester derivatives Methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, etc. (4) olefins ethylene, propylene, isobutylene, etc. (5) vinyl esters vinyl propionate, vinyl acetate, vinyl benzoate, etc. (6) vinyl ether (7) Vinyl ketones Vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, etc. (8) N-vinyl compounds N-vinyl carbazole, N-vinyl India (9) Others Vinyl compounds such as vinyl naphthalene and vinyl pyridine, acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide, etc. In addition, the polyfunctional vinyls shown below are used. It is also possible to produce a crosslinked resin by using it. Specific examples of the polyfunctional vinyls are shown below. That is,
Divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, etc. Clear according to the present invention Specific examples of the polymerizable monomer that can be used for preparing the resin constituting the toner have been described above, but the polymerization that can be used for preparing the resin constituting the clear toner according to the present invention The sex monomer is not limited to these. In the case of preparing a resin obtained from a radical polymerizable monomer containing a radical polymerizable monomer having a divalent or higher acid group, the above-mentioned radical polymerizable monomer having a divalent or higher acid group and another vinyl monomer The body can be combined to produce a resin. Similarly, when preparing a resin obtained from a radical polymerizable monomer that does not contain a radical polymerizable monomer having an acidic group having a valence of 2 or more, a resin can be prepared by combining a plurality of types of vinyl monomers. it can.

Next, the monoester compound and hydrocarbon compound contained in the clear toner according to the present invention will be described. The clear toner according to the present invention contains a monoester compound represented by the following general formula (1) and a hydrocarbon compound having at least one of a branched chain structure and a cyclic structure described later. . By using these monoester compounds and hydrocarbon compounds in combination,
That is, the adhesive action between the clear toner surface and the belt surface is suppressed by the releasing action of the monoester compound represented by the general formula (1), and even if the belt surface has irregularities, the irregularities on the belt surface are cleared. It was thought that transfer to the toner surface was difficult. At the same time, the present inventor fears the crystallization effect of the monoester compound, and uses a hydrocarbon compound having at least one of a branched chain structure and a cyclic structure to crystallize the monoester compound. I thought that the degree would be aligned. By using a monoester compound and a hydrocarbon compound in combination, the unevenness of the belt surface is prevented from being transferred to the clear toner surface, and the degree of crystallization of the monoester compound is made uniform by the action of the hydrocarbon compound. A clear toner surface that does not cause scattering can be formed.

  Hereinafter, the monoester compound represented by the general formula (1) contained in the clear toner according to the present invention and the hydrocarbon compound having at least one of a branched chain structure and a cyclic structure will be described.

The monoester compound contained in the clear toner according to the present invention is composed of R ¹ which is a fatty acid component and an alcohol component R ^{2 as} represented by the following general formula (1).

General formula (1): R < ¹ > -COO-R < ² >
In the general formula (1), R ¹ and R ² are each a hydrocarbon group having 13 to 30 carbon atoms, preferably 17 to 22 carbon atoms. R ¹ and R ² may each have a substituent or may not have a substituent. R ¹ and R ² may be the same or different.

  Specific examples of the monoester compound represented by the general formula (1) include compounds represented by the following formulas (1-1) to (1-12). In addition, the monoester compound represented by General formula (1) which can be used by this invention is not limited to what is shown below.

_{(1-1): CH 3 - (} CH 2) 12 -COO- (CH 2) 13 -CH 3
_{(1-2): CH 3 - (} CH 2) 14 -COO- (CH 2) 15 -CH 3
_{(1-3): CH 3 - (} CH 2) 16 -COO- (CH 2) 17 -CH 3
_{(1-4): CH 3 - (} CH 2) 16 -COO- (CH 2) 21 -CH 3
_{(1-5): CH 3 - (} CH 2) 20 -COO- (CH 2) 17 -CH 3
_{(1-6): CH 3 - (} CH 2) 20 -COO- (CH 2) 21 -CH 3
_{(1-7): CH 3 - (} CH 2) 25 -COO- (CH 2) 25 -CH 3
_{(1-8): CH 3 - (} CH 2) 25 -COO- (CH 2) 29 -CH 3
_{(1-9): CH 3 - (} CH 2) 12 -COO- (CH 2) 12 -CH 3
_{(1-10): CH 3 - (} CH 2) 16 -COO- (CH 2) 16 -CH 3
_{(1-11): CH 3 - (} CH 2) 21 -COO- (CH 2) 21 -CH 3
_{(1-12): CH 3 - (} CH 2) 29 -COO- (CH 2) 29 -CH 3
(1-13): CH ₃ — (CH ₂ ) ₁₆ —COO— (CH ₂ ) ₁₂ —CH _{3
(1-14): CH 3 - (} CH 2) 17 -COO- (CH 2) 14 -CH 3
In the present invention, one type of monoester compound represented by the general formula (1) may be used, or two or more types of monoester compounds represented by the general formula (1) may be used in combination. Is possible.

  The monoester compound represented by the general formula (1) used in the present invention preferably has a melting point of 30 ° C to 100 ° C, more preferably 39 ° C to 90 ° C. The measurement of the melting point of the monoester compound represented by the general formula (1) used for the clear toner according to the present invention is generally called “measurement of transparent melting point”. “Measurement of transparent melting point” is to measure the temperature of a transparent solid sample at the same time as the light transmission measurement of the sample and record the melting process. The melting point is measured by determining the end temperature.

  Specifically, the monoester compound powder, which is a transparent sample, is packed in a predetermined capillary tube and placed in a furnace, and the melting process is monitored by light. And when the sample melts and becomes transparent, the amount of light received by the photocell increases, so that a signal change corresponding to the increase in the amount of received light is detected by the circuit, and the melting point of the monoester compound is measured from the result. Is to be calculated. Examples of a commercially available apparatus capable of measuring the transparent melting point of the monoester compound used in the present invention include an automatic melting point measuring apparatus “FP90 / FP81HT” manufactured by “Mettler Toledo”.

An automatic melting point measuring device manufactured by “Mettler Toledo” is composed of a control unit “FP90” and a measuring furnace “FP81HT”, and the conditions for measuring the transparent melting point of the monoester compound used in the present invention are as follows: It is. That is,
Control unit "FP90"
Reading accuracy: 0.1 ° C
Temperature sensor: PT100
Temperature increase rate: 10 ° C / min (specifications selectable from 0 to 20 ° C / min)
Measurement function: Melting point (melting start temperature, melting end temperature)
Measuring furnace "FP81HT"
Heating method: Heater block Measuring point: Melting point, cloud point 3 points,
Measurement range: Room temperature to 375 ° C
Reproducibility: Melting point 0.1 ° C. (when measuring benzoic acid with a purity of 99.99% at a heating rate of 0.2 ° C./min)
Moreover, the capillary which stuffs the monoester compound which is a sample can use the thing of outer diameter 2.0-3.1mm and length 80mm.

  Next, a hydrocarbon compound having a branched chain structure and a hydrocarbon compound having a cyclic structure that can be used in the clear toner according to the present invention will be described. In the present invention, the clear toner contains at least one of a hydrocarbon compound having a branched chain structure and a hydrocarbon compound having a cyclic structure described below, and these can be used in combination of two or more kinds. It is. In addition to the mold release action of these hydrocarbon compounds, as described above, when the clear toner layer is cooled, it has the action of suppressing the crystallization of the monoester compound and aligning the degree of crystallization. It is considered a thing.

  The hydrocarbon compound having a branched chain structure that can be used in the clear toner according to the present invention has a total ratio of tertiary carbon atoms and quaternary carbon atoms in the total carbon atoms constituting the hydrocarbon compound of 0.1%. It is preferable to be in the range of ˜20%. The total ratio of tertiary carbon atoms and quaternary carbon atoms in all carbon atoms can be calculated by the method described later.

  When the total ratio of tertiary carbon atoms and quaternary carbon atoms in all the carbon atoms constituting the hydrocarbon compound having a branched chain structure is in the above range, the hydrocarbon compound and monoester compound having the branched chain structure It is considered that more effective interaction is expressed between the two. That is, it is considered that a moderate molecular entanglement is more reliably formed between the hydrocarbon compound molecule and the monoester compound molecule, and the degree of crystallization can be made uniform by suppressing the crystallization of the monoester compound. It is done.

The ratio of branching of the hydrocarbon compound having a branched chain structure, that is, the ratio of the total of tertiary carbon atoms and quaternary carbon atoms in all the carbon atoms constituting the hydrocarbon compound is obtained by a 13C-NMR measurement method. From the spectrum, it can be calculated from the following formula. That means
Formula: Ratio of branch (%) = [(C3 + C4) / (C1 + C2 + C3 + C4)] × 100
[Wherein, C3 represents a peak area related to a tertiary carbon atom, C4 represents a peak area related to a quaternary carbon atom, C1 represents a peak area related to a primary carbon atom, and C2 represents a peak area related to a secondary carbon atom. ]
The conditions for the ¹³ C-NMR measurement method are as follows. That is,
Measuring apparatus: FT NMR apparatus Lambda400 (manufactured by JEOL Ltd.)
Measurement frequency: 100.5 MHz
Pulse condition: 4.0 μs
Data points: 32768
Delay time: 1.8 sec
Frequency range: 27100Hz
Integration count: 20000 times Measurement temperature: 80 ° C
Solvent: benzene-d ⁶ / o-dichlorobenzene-d ⁴ = ¼ (v / v)
Sample concentration: 3% by mass
Sample tube: φ5mm
Measurement mode: 1H complete decoupling method Hydrocarbon compounds having a branched chain structure and hydrocarbon compounds having a cyclic structure include, for example, HNP-0190, Hi-Mic-1045, manufactured by Nippon Seiwa Co., Ltd. Mainly composed of compounds called microcrystalline wax such as Hi-Mic-1070, Hi-Mic-1080, Hi-Mic-1090, Hi-Mic-2045, Hi-Mic-2065, Hi-Mic-2095, and isoparaffin. There are certain compounds EMW-0001, EMW-0003, and the like.

  Here, the microcrystalline wax is different from the paraffin wax whose main component is a linear hydrocarbon (normal paraffin) in petroleum wax, but is composed of a branched hydrocarbon (isoparaffin) or a cyclic hydrocarbon (cycloparaffin). It is a wax with a large proportion. In general, since microcrystalline wax contains a large amount of low crystalline isoparaffin and cycloparaffin, the crystal is smaller than paraffin wax and has a larger molecular weight than paraffin wax. Such microcrystalline wax has a carbon number of 25 to 60, a mass average molecular weight of 500 to 800, and a melting point of 60 to 95 ° C.

  The microcrystalline wax composed of a hydrocarbon having a branched chain structure or a hydrocarbon compound having a cyclic structure is preferably, for example, one having a weight average molecular weight of 600 to 800 and a melting point of 60 to 95 ° C. Further, those having a number average number average molecular weight of 300 to 1,000 are preferred, and those having a number average molecular weight of 400 to 800 are more preferred. Moreover, what has ratio Mw / Mn of a weight average molecular weight and a number average molecular weight in the range of 1.01-1.20 is preferable.

  As a production method for obtaining a hydrocarbon compound having a branched chain structure represented by the microcrystalline wax or a hydrocarbon compound having a cyclic structure, for example, a press sweating method or a solvent extraction method is representative. . The press sweating method is a method in which a raw material oil is solidified in a state maintained at a specific temperature to separate and extract a desired hydrocarbon, and the solvent extraction method is a petroleum distillation residue oil or heavy distillate oil. In this method, a solvent is added to a raw material oil for crystallization, and then a desired hydrocarbon is extracted by filtration. Among these, the latter solvent extraction method is preferable. Moreover, since the hydrocarbon compound having a branched chain structure or a cyclic structure obtained by the above production method is often colored, it is purified using sulfuric acid white earth or the like.

The clear toner according to the present invention may be used in combination with the following known waxes together with the monoester compound represented by the general formula (1) and the hydrocarbon compound having a branched chain structure or a cyclic structure. Is possible.
(1) Polyolefin wax Polyethylene wax, polypropylene wax, etc. (2) Long chain hydrocarbon wax, paraffin wax, sazol wax, etc. (3) Dialkyl ketone wax, distearyl ketone, etc. (4) Ester wax Carnauba wax, Montan Wax, trimethylolpropane tribehenate, pentaerythritol tetramyristate, pentaerythritol tetrastearate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerol tribehenate, 1,18-octadecanediol di Stearate, trimellitic trimellitic acid, distearyl maleate, etc. (5) Amide wax Ethylenediamine dibehenyl amide, trimellitic acid triste The melting point of Riruamido such as wax is usually from 40 to 125 ° C., preferably from 50 to 120 ° C., more preferably from 60 to 90 ° C.. By setting the melting point within the above range, the heat-resistant storage stability of the clear toner is ensured, and a stable glossy surface can be formed even when the clear toner layer is melted at a low temperature. The wax content in the clear toner is 1% by mass to 30% by mass in combination with the monoester compound represented by the general formula (1) and the hydrocarbon compound having a branched chain structure or a cyclic structure. Preferably, 5% by mass to 20% by mass is more preferable.

  Next, a clear toner manufacturing method according to the present invention will be described.

  The clear toner according to the present invention comprises at least particles comprising the above-described resin and a monoester compound represented by the general formula (1), a hydrocarbon compound having a branched chain structure or a cyclic structure. Is. The method for producing the particles constituting the clear toner according to the present invention is not particularly limited, and a known method for producing a toner used for electrophotographic image formation can be applied. That is, a so-called pulverization method for producing a toner through kneading, pulverization, and classification steps, and a so-called polymerization method for polymerizing a polymerizable monomer and simultaneously forming particles while controlling the shape and size. Can be applied.

  Among them, the clear toner produced by the polymerization method can easily obtain characteristics such as uniform particle size distribution, shape distribution, and sharp charge distribution. The toner production method using a polymerization method includes a step of forming resin particles by a polymerization reaction such as suspension polymerization or emulsion polymerization. Among them, resin particles produced through the polymerization reaction are aggregated and fused. What is produced through an association step for forming particles is particularly preferred.

  Further, when the clear toner according to the present invention is produced through the association process, a clear toner having a core-shell structure having a structure that ensures both low-temperature fixability and heat-resistant storage stability can also be produced. A clear toner having a core-shell structure is formed by first forming a core with resin particles having a low softening point temperature or glass transition temperature, and then aggregating and fusing resin particles having a high softening point temperature or glass transition temperature on the core surface to form a shell. To form a clear toner having a core-shell structure.

  In a clear toner having a core-shell structure, it is preferable to form a core using a resin that melts at a lower fixing temperature and imparts an appropriate internal cohesive force to the clear toner layer. By using a resin having such properties, the clear toner layer peeled off from the belt member is not broken after being heated and cooled while the surface of the clear toner layer is in contact with the belt member. A toner layer can be formed. In addition, a clear toner layer can be formed satisfactorily without causing a problem of hot offset due to the clear toner broken in a molten state.

  Furthermore, by forming a shell using a resin with a high glass transition temperature, even if clear toner is stored for a long time in a thermally unstable environment such as a high temperature and high humidity environment, the clear toner particles are attached to each other. It can be stored in a stable state without being worn.

  Hereinafter, as an example of a method for producing a clear toner according to the present invention, a method for producing a clear toner by an emulsion association method will be described. A method for producing a clear toner by an emulsion association method is performed, for example, through the following steps.

(1) Production process of resin particle dispersion (2) Aggregation / fusion process of resin particles (3) Aging process (4) Cooling process (5) Washing process (6) Drying process (7) External additive treatment process Each step will be described.

(1) Production process of resin particle dispersion In this process, resin particles having a size of about 100 nm are obtained by introducing a radical polymerizable monomer that forms resin particles constituting the clear toner into an aqueous medium and performing polymerization. It is a process of forming. In the present invention, resin particles obtained by polymerizing a radically polymerizable monomer containing a radically polymerizable monomer having a divalent or higher acidic group, and a radically polymerizable property not containing a radically polymerizable monomer having a divalent or higher acidic group. Monomers are polymerized to produce resin particles.

  In the present invention, the monoester compound represented by the general formula (1) and a hydrocarbon compound having a branched chain structure or a cyclic structure are dissolved or dispersed in the radical polymerizable monomer, It can be polymerized in the medium. In this way, resin particles containing the monoester compound represented by the general formula (1) and a hydrocarbon compound having a branched chain structure or a cyclic structure can be formed. Furthermore, the above-mentioned wax can be dissolved or dispersed in the radical polymerizable monomer and polymerized in an aqueous medium to form resin particles containing the wax.

(2) Aggregation / fusion process of resin particles In this process, resin particles are aggregated in an aqueous medium to form particles, and the particles formed by aggregation are fused to form particles (clear toner before external addition treatment). This is a step corresponding to a so-called “step of aggregating resin particles”. Namely, a resin particle formed by polymerizing a radical polymerizable monomer containing a radical polymerizable monomer having a divalent or higher acidic group, and a radical polymerizable monomer not containing a radical polymerizable monomer having a divalent or higher acidic group Particles are produced by agglomerating and fusing resin particles formed by polymerization. The resin particles contain a monoester compound represented by the general formula (1) and a hydrocarbon compound having a branched chain structure or a cyclic structure by the above method. Thus, particles containing the monoester compound and the hydrocarbon compound can be formed.

  In this step, the resin particles are aggregated by adding an aggregating agent such as an alkali metal salt or an alkaline earth metal salt typified by magnesium chloride into the aqueous medium in which the resin particles are present. Next, the water-based medium is heated to a temperature equal to or higher than the glass transition temperature of the resin particles to advance the aggregation, and at the same time, the aggregated resin particles are fused together. And when aggregation is advanced and the particle | grain size becomes a target, salt, such as salt, is added and aggregation is stopped.

(3) Ripening step This step is a so-called shape control step in which the reaction system is heat-treated to ripen the shape of the particles to a desired average circularity following the aggregation / fusion step.

(4) Cooling step This step is a step of cooling (rapid cooling) the dispersion of the particles. As a cooling treatment condition, cooling is performed at a cooling rate of 1 to 20 ° C./min. The cooling treatment method is not particularly limited, and examples thereof include a method of cooling by introducing a refrigerant from the outside of the reaction vessel, and a method of cooling by directly introducing cold water into the reaction system.

(5) Washing step This step includes a step of solid-liquid separation of the particles from the particle dispersion liquid cooled to a predetermined temperature in the above step, and a cake-like aggregate called a wet toner cake that has been solid-liquid separated. It comprises a washing step for removing deposits such as surfactants and coagulants from the particles.

  In the washing treatment, water washing is performed until the electric conductivity of the filtrate becomes, for example, about 10 μS / cm. Examples of the solid-liquid separation method include a centrifugal separation method, a vacuum filtration method using Nutsche and the like, a filtration method using a filter press and the like, and are not particularly limited in the present invention.

(7) Drying step This step is a step of drying the washed particles. Examples of the dryer used in this step include a spray dryer, a vacuum freeze dryer, and a vacuum dryer, and a stationary shelf dryer, a mobile shelf dryer, a fluidized bed dryer, and a rotary dryer. It is preferable to use a stirring dryer or the like.

  The moisture of the dried particles is preferably 5% by mass or less, more preferably 2% by mass or less. In addition, when the dried particles are aggregated due to weak interparticle attractive force, the aggregate may be crushed. Here, as the crushing processing apparatus, a mechanical crushing apparatus such as a jet mill, a Henschel mixer, a coffee mill, or a food processor can be used.

(8) External additive treatment step This step is a step of adding an external additive or a lubricant to the dried particles. The particles that have undergone the drying step can be used as clear toner particles as they are, but the chargeability, fluidity, and cleaning properties of the clear toner can be improved by adding external additives. As these external additives, known inorganic fine particles, organic fine particles, and aliphatic metal salts can be used, and the addition amount thereof is 0.1 to 10.0% by mass, preferably 0.5% with respect to the whole toner. It is -4.0 mass%. In addition, various external additives can be added in combination. In addition, as a mixing apparatus used when adding an external additive, there exist well-known mechanical mixing apparatuses, such as a turbula mixer, a Henschel mixer, a Nauta mixer, a V-type mixer, a coffee mill, for example.

  By passing through the above process, the clear toner which concerns on this invention can be produced with an emulsion association method.

  Next, the clear toner according to the present invention is supplied to the entire surface of the transfer material on which the image is formed, and the clear toner is heated and cooled in a state of being in close contact with the belt, thereby forming a glossy surface on the entire surface of the transfer material. A gloss imparting apparatus that performs this will be described. FIG. 1 is a schematic diagram showing a representative example of a gloss applying device that forms a glossy surface on the entire image surface of a transfer material using the clear toner according to the present invention.

The gloss imparting device 1 shown in FIG. 1 has at least the following configuration. That is,
(1) A heating and pressing apparatus 10 that heats and simultaneously pressurizes the transfer material P in a state where clear toner is supplied over the entire image surface.
(2) A belt member 11 that contacts the clear toner surface melted by the heating and pressing device 10 and forms an adhesive surface between the clear toner surface and conveys the transfer material P.
(3) Cooling fans 12 and 13 for supplying cooling air to the transfer material P being conveyed while being adhered to the belt member 11
(4) Consists of a transport roll 14 that transports the transfer material cooled by the action of air supplied from the cooling fans 12 and 13 and having the clear toner surface fixed thereto.

  Each configuration will be specifically described below.

  First, the heating and pressing apparatus 10 will be described. The heating and pressing apparatus 10 shown in FIG. 1 sandwiches and conveys a transfer material P supplied with clear toner between a pair of rolls 101 and 102 that are driven at a constant speed, and the transferred transfer material has been conveyed. Is heated and pressurized. That is, the clear toner supplied to the entire surface of the transfer material P is melted by heating by the heating and pressing device 10, and the melted clear toner becomes a layer having a uniform thickness by pressing. Here, by providing a heat source at the center of one or both of the pair of rolls 101 and 102, the clear toner supplied to the entire surface of the transfer material can be heated so as to melt. Further, it is preferable that the two rolls 101 and 102 have a press-contact structure so that the clear toner melted between the rolls can be reliably pressed.

  From the viewpoint of power consumption and work efficiency, for example, the gloss applying device 1 in FIG. 1 is sufficient if the roll 101 constituting the heating and pressing device 10 is a heating roll and the roll 102 is a pressing roll. Can be heated and pressurized. A silicone rubber layer or a fluororubber layer can be disposed on one or both surfaces of the rolls 101 and 102, and the width of the nip region for heating and pressing is preferably in the range of about 1 mm to 8 mm.

  The heating roll 101 is formed, for example, by coating an elastic body layer made of silicone rubber or the like on the surface of a metal base such as aluminum and having a predetermined outer diameter. For example, a halogen lamp of 300 to 350 W is disposed inside the heating roll 101 as a heating source, and is heated from the inside so that the surface temperature of the heating roll 101 becomes a predetermined temperature.

  The pressure roll 102 is formed, for example, by coating an elastic body layer made of silicone rubber or the like on the surface of a metal base such as aluminum, and further, on the surface of the elastic body layer, PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether). The release layer is coated with a tube made of (copolymer) and formed to have a predetermined outer diameter. A 300 to 350 W halogen lamp, for example, can also be disposed inside the pressure roll 102 as a heating source, and is heated from the inside so that the surface temperature of the pressure roll 102 becomes a predetermined temperature.

  In the heating and pressing apparatus 10, the transfer material P to which the clear toner is supplied over the entire image forming surface is heated at the surface where the clear toner is supplied to the pressure contact portion (nip portion) between the heating roll 101 and the pressure roll 102. It is introduced so as to be arranged on the roll 101 side. Then, while passing through the pressure contact portion between the heating roll 101 and the pressure roll 102, the clear toner is heated and melted, and at the same time, is fused as a clear toner layer having a predetermined thickness on the image surface.

  Next, the belt member 11 will be described. As shown in FIG. 1, the belt member 11 has an endless belt-like configuration that is rotatably supported by a heating roll 101 and a plurality of rolls 101, 103, and 104 including the heating roll 101. As described above, the belt member 11 is stretched around a plurality of rolls including a heating roll 101, a peeling roll 103, and a driven roll 104 so as to be rotatable, and is predetermined by the heating roll 101 that is rotated by a driving source (not shown). It is designed to drive the moving speed. Then, it can be rotated and driven without wrinkles at a predetermined process speed by the driving by the heating roll 101 and the tension by the peeling roll 103 and the driven roll 104.

  Since the belt member 11 forms an adhesive surface with the melted clear toner surface and transports the transfer material P through the melted clear toner surface, the belt member 11 has a certain degree of heat resistance and mechanical strength. It can produce with the material of. Specific examples include heat-resistant film resins such as polyimide, polyether polyimide, PES (polyether sulfone resin), and PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin). A release layer of fluororesin such as PTFE (polytetrafluoroethylene) or PFA or silicone rubber is preferably provided on at least the clear toner layer contact surface side of the heat resistant film resin.

  The thickness of the belt member 11 is not particularly limited as long as the transfer material can be conveyed through the adhesive surface with the melted clear toner surface, and can be used with a known thickness. . Specifically, the thickness of the heat-resistant film resin is preferably 20 μm to 80 μm, the thickness of the release layer is preferably 10 μm to 30 μm, and the total thickness is preferably 20 μm to 110 μm. As a specific form, for example, a polyimide endless film having a thickness of 80 μm and a silicone rubber layer having a thickness of 30 μm are coated.

  Next, the cooling fans 12 and 13 will be described. A gloss applying device 1 shown in FIG. 1 includes a cooling fan 12 between a heating roll 101 and a peeling roll 103 on the inner surface side of the belt member 11, and a pressure roll 102 and a conveying roll 14 on the outer surface side of the belt member 11. A cooling fan 13 is provided. Here, the outer surface of the belt member 11 is a surface that adheres to the transfer material P through the melted clear toner surface and carries and conveys the transfer material P in a state where an adhesive surface is formed.

  The gloss applying device 1 in FIG. 1 is bonded to the outer surface of the belt member 11 with a clear toner layer melted by the above-described heating and pressing device 10 and having a predetermined thickness by pressing, and the transfer material P is conveyed in this state. At the same time, the clear toner layer is cooled and solidified. The cooling fans 12 and 13 forcibly cool the transfer material P on which the clear toner layer is formed and carried on the belt member 11. The gloss applying device 1 can be connected to the cooling fans 12 and 13 and provided with a heat sink or heat pipe for cooling. Such a cooling heat sink or heat pipe can promote cooling and solidification of the molten clear toner layer.

  The forced cooling by the cooling fans 12 and 13 promotes solidification of the clear toner layer of the transfer material P being conveyed to the belt member 11. The clear toner layer is sufficiently cooled and solidified when it is transported to the vicinity of the end where the transport assisting roll 14 and the peeling roll 103 are disposed. At the end, the transfer material P is as follows from the belt member 11. It is peeled by a simple procedure.

  First, the transfer material P conveyed near the end portion is in a state of being carried and conveyed by the belt member 11 via the clear toner layer. In this state, the conveyance auxiliary roll 14 is moved to the transfer material P. It holds while assisting the conveyance by contacting the back surface. When the belt member 11 reaches the point of the peeling roll 103 while the conveyance auxiliary roll 14 holds the transfer material P from the back surface, the belt member 11 changes the conveyance direction to the direction of the driven roll 104 (upward in the drawing). . At this time, the transfer material P is peeled off from the belt member 11 by its own rigidity (waist) and is discharged from the gloss applying device 1 by the transport roll 14.

  Through the above procedure, the gloss applying device 1 shown in FIG. 1 supplies clear toner over the entire transfer material on which an image is formed, and heats and pressurizes the supplied clear toner to clear a molten state having a predetermined thickness. A toner layer is formed. Then, the transfer material P on which the melted clear toner layer is formed is carried on the belt member, and the clear toner layer is cooled and solidified while being conveyed, and after the clear toner layer is solidified, the transfer material P is peeled off from the belt member 11. The transfer material P peeled off from the belt member 11 is discharged out of the apparatus.

  1 realizes peeling of the transfer material P from the belt member 11 by the conveyance auxiliary roll 14 and the peeling roll 103. Instead of the peeling roll 103, for example, a peeling claw is used as the belt member. Even if the transfer material P is disposed between the belt member 11 and the transfer material P, the transfer material P can be peeled off from the belt member 11.

  As described above, in the present invention, an image for forming a clear toner layer is not particularly limited in its production method. For example, a known image such as an electrophotographic method, a printing method, an ink jet method, or a silver salt photographic method is used. There are images produced by the forming method.

  FIG. 2 is a cross-sectional configuration diagram of an electrophotographic image forming apparatus capable of forming a full color image by an electrophotographic method and forming a clear toner layer over the entire surface of the formed full color toner image. The image forming apparatus shown in FIG. 2 is different in configuration from the gloss imparting apparatus 1 shown in FIG. 1, but, like the gloss imparting apparatus 1 shown in FIG. A possible fixing device 50 is mounted.

  When forming a full-color image having a clear toner layer with the image forming apparatus shown in FIG. 2, the gloss applying device 1 shown in FIG. 1 is arranged near the paper discharge unit 90 of the image forming device 2 as shown in FIG. A configuration is preferable. With such a configuration, the clear toner formed on the entire surface of the transfer material by processing the printed matter fixed by the fixing device 50 built in the image forming apparatus of FIG. The strength of the layer can be improved, and a strong glossy surface with high image clarity can be formed. Further, since the fixing strength of the toner image is also improved, it is particularly preferable for producing a poster for outdoor display. An example of the arrangement of the gloss applying device 1 to the image forming apparatus 2 shown in FIG. 2 will be described later with reference to FIG.

  The image forming apparatus 2 shown in FIG. 2 is generally called a “tandem color image forming apparatus”, and includes a clear toner layer forming unit 20S, a plurality of sets of toner image forming units 20Y, 20M, 20C, and 20Bk, and a belt-like shape. The intermediate transfer belt 26, a paper feeding device 40, a fixing device 50, and the like are included.

  An image reading unit 23 is installed on the upper part of the image forming apparatus 2. The document placed on the document table is scanned and exposed by the optical system of the document image scanning exposure apparatus of the image reading unit 23 and read by the line image sensor. The analog signal photoelectrically converted by the line image sensor is subjected to analog processing, A / D conversion, shading correction, image compression processing, etc. in the control means, and then input to the exposure units 30S, 30Y, 30M, 30C, and 30Bk. The

  In the present invention, the constituent elements are collectively indicated by reference numerals with alphabetic suffixes omitted, and the individual constituent elements are indicated by S (clear toner), Y (yellow), M (magenta), C (Cyan) and Bk (black) are indicated by reference numerals with suffixes.

  Clear toner supply unit 20S for supplying clear toner to the entire surface of the transfer material using the clear toner according to the present invention, yellow image forming unit 20Y for forming a yellow toner image, and magenta image forming unit for forming a magenta toner image 20M, a cyan image forming unit 20C for forming a cyan toner image, and a black image forming unit 20Bk for forming a black toner image are respectively drum-shaped photoconductors 21 (21S, 21Y, 21M, 21C, 21Bk) around the strip electrode 22 (22S, 22Y, 22M, 22C, 22Bk), the exposure unit 30 (30S, 30Y, 30M, 30C, 30Bk), the developing device 24, and the cleaning device 25 (25S, 25Y, 25M, 25C, 25Bk).

  The photoconductor 21 is made of an organic photoconductor in which a photosensitive layer made of a resin containing an organic photoconductor is formed on the outer peripheral surface of a drum-shaped metal base, and the width direction ( In FIG. 2, they are arranged so as to extend in a direction perpendicular to the paper surface. As the resin constituting the photosensitive layer, for example, a known photosensitive layer forming resin such as a polycarbonate resin is used. In the embodiment shown in FIG. 2, the configuration example using the drum-shaped photoconductor 21 is described. However, the configuration is not limited to this, and a belt-shaped photoconductor may be used.

  The developing device 24 is a two-component development composed of a clear toner (S), a yellow toner (Y), a magenta toner (M), a cyan toner (C), and a black (Bk) of different colors according to the present invention and a carrier. It contains an agent. As a two-component developer, a carrier having ferrite as a core coated with an insulating resin around it, a clear toner according to the present invention, a known binder resin, a known pigment, a colorant such as carbon black, a charge control agent, It is composed of toners of various colors containing silica, titanium oxide and the like.

  For example, the carrier has an average particle diameter of 10 to 50 μm, a saturation magnetization of 10 to 80 emu / g, and the toner has a particle diameter of 4 to 10 μm. Further, the charging characteristics of the toner used in the image forming apparatus shown in FIG. 2 including the clear toner according to the present invention are negative charging characteristics, and the average charge amount is −20 to −60 μC / g. preferable. The two-component developer is prepared by mixing and adjusting the carrier and the toner so that the toner concentration becomes 4% by mass to 10% by mass.

The intermediate transfer belt 26 that is an intermediate transfer member is rotatably supported by a plurality of rollers. The intermediate transfer belt 26 is an endless belt having a volume resistance of 10 ⁶ to 10 ¹² Ω · cm, for example. The intermediate transfer belt 26 is made of a known resin material such as polycarbonate (PC), polyimide (PI), polyamideimide (PAI), polyvinylidene fluoride (PVDF), tetrafluoroethylene-ethylene copolymer (ETFE). Can be formed. The thickness of the intermediate transfer belt 26 is preferably 50 to 200 μm.

  The clear toner layer formed on each photoconductor 21 (21S, 21Y, 21M, 21C, 21Bk) from the clear toner supply unit 20S and the toner image forming units 20Y, 20M, 20C, and 20Bk and each color toner image are rotated in the middle. The image is sequentially transferred onto the transfer belt 26 by the primary transfer rollers 27 (27S, 27Y, 27M, 27C, 27Bk) (primary transfer), and a full color image combined with the clear toner layer is formed on the intermediate transfer belt 26. On the other hand, after the image transfer, the residual toner is removed from the photoreceptors 21Y, 21M, 21C, and 21Bk by the cleaning devices 25 (25S, 25Y, 25M, 25C, and 25Bk) of the respective colors.

  The transfer material P stored in the paper storage unit (tray) 41 of the paper supply device 40 is supplied by the first paper supply unit 42, and is supplied with paper supply rollers 43, 44, 45A, 45B, registration rollers (second supply). The paper is conveyed to the secondary transfer roller 29 through the paper portion 46 and the like, and the clear toner layer and the color image are transferred onto the transfer material P (secondary transfer).

  Note that the three-stage paper storage units 41 arranged vertically in the vertical direction below the image forming apparatus 2 have substantially the same configuration, and thus are given the same reference numerals. The three-stage sheet feeding units 42 have the same configuration and are therefore given the same reference numerals. The paper storage unit 41 and the paper supply unit 42 are collectively referred to as a paper supply device 40.

  The transfer material P on which the clear toner layer and the full color image have been transferred is sandwiched by the fixing device 50 and melted and solidified by the action of heating and pressurization, so that the clear toner layer is formed on the entire surface of the transfer material P. The provided full-color toner image is fixed on the transfer material P. The transfer material P is nipped and conveyed by the conveyance roller pair 57, is discharged from the discharge roller 47 provided in the discharge conveyance path, and is placed on a discharge tray 90 outside the apparatus.

  On the other hand, after the clear toner layer and the full color toner image are transferred onto the transfer material P by the secondary transfer roller 29, the intermediate transfer belt 26 from which the transfer material P is further separated in curvature remains by the cleaning device 261 for the intermediate transfer belt. The removed toner is removed.

  When forming a full color image having a clear toner layer on both sides of the transfer material P, the transfer material P is branched after the clear toner layer and the full color image formed on the first surface of the transfer material P are melted and solidified. The sheet is branched from the paper discharge conveyance path by the plate 49, introduced into the double-side conveyance path 48, turned upside down, and conveyed again from the paper feed roller 45B. The transfer material P forms a full-color toner image composed of the clear toner layer and each color on the second surface by the clear toner supply unit 20S and the image forming units 20Y, 20M, 20C, and 20Bk for each color, and is heated and pressed by the fixing device 50. The paper is processed and discharged out of the apparatus by a paper discharge roller 47. In this way, it is possible to form a full-color toner image that is glossed by the clear toner layer on both surfaces of the transfer material P.

  As described above, a full-color image having a glossy surface on the entire surface of the transfer material P can be formed by the image forming apparatus shown in FIG. In the present invention, as shown in FIG. 3, the gloss applying device 1 can be arranged in the image forming apparatus 2 of FIG. Here, FIG. 3 is a schematic diagram showing an example of an apparatus in which the gloss imparting apparatus 1 is attached to the image forming apparatus 2 shown in FIG. FIG. 3A shows a case where the gloss imparting device 1 is arranged at a position of the paper discharge unit 90 of the image forming apparatus 2 in FIG. 2 and is subjected to fixing processing by the fixing device 50 built in the image forming apparatus 2 in FIG. Further, the clear toner layer formed on the entire surface of the transfer material is further fixed on the transfer material P by the gloss applying device 1, and the clear toner layer can form a strong glossy surface with high image clarity. Further, since the fixing strength of the toner image is also improved, it is particularly preferable for the production of a poster or the like for outdoor posting.

  FIG. 3B is a diagram in which the gloss applying device 1 is arranged at the fixing device 50 of the image forming apparatus 2 shown in FIG. 2, and the clear image transferred onto the transfer material P by the secondary transfer roller 29. The toner layer and the full color toner image can be fixed simultaneously by the gloss applying device 1. According to the apparatus shown in FIG. 3B, the gloss applying apparatus 1 can be incorporated in the image forming apparatus 2, which is preferable for realizing a compact apparatus.

  The transfer material capable of forming a glossy image using the clear toner according to the present invention is also called an image support, and can form an image by a known method and can form and hold a clear toner layer. There is no particular limitation as long as it is anything. Examples of the transfer material that can be used in the present invention include known materials such as plain paper from thin paper to thick paper, high-quality paper, art paper, coated printing paper such as coated paper, and commercially available Japanese paper. There are postcard paper, plastic films for OHP, cloth, and the like.

  Examples of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In addition, although there is a part described as "part" in the following sentence, it represents "mass part".

1. Production of “Clear Toners 1 to 16” The following 16 types of clear toners were prepared.

(1) Preparation of “Clear Toner 1” (a) Preparation of “Resin Particle 1” According to the following procedure, the “clear toner 1” is obtained from a radical polymerizable monomer including a “radical polymerizable monomer having a divalent or higher acid group” in the present invention. A dispersion of “resin particles 1” corresponding to “resin” was prepared. That is,
7.08 parts by mass of an anionic surfactant (sodium dodecylbenzenesulfonate: SDS) was dissolved in 2760 parts by mass of ion-exchanged water in a reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction device. An aqueous agent solution was prepared. While stirring the surfactant aqueous solution at a stirring speed of 230 rpm under a nitrogen stream, the temperature was raised to 80 ° C.

On the other hand, the following compound styrene 125.0 parts by mass n-butyl acrylate 75.0 parts by mass Itaconic acid 50.0 parts by mass was mixed, heated to 80 ° C. and dissolved to prepare a monomer mixed solution. .

  Next, while using a mechanical dispersion device having a circulation path, the surfactant aqueous solution heated to 80 ° C. and the monomer mixed solution are mixed and dispersed to obtain an emulsified particle dispersion having a uniform dispersed particle size. Produced. Next, a solution obtained by dissolving 0.84 parts by mass of potassium persulfate (KPS) in 200 parts by mass of ion-exchanged water was added, and the polymerization reaction was performed by heating and stirring at 80 ° C. for 3 hours. Cooling to 0 ° C. produced “resin particle dispersion 1”. The “resin particles 1” constituting the “resin particle dispersion 1” had a weight average molecular weight of 350,000.

(B) Production of “resin particle 2” According to the following procedure, “resin particle corresponding to“ resin obtained from radical polymerizable monomer not containing radical polymerizable monomer having divalent or higher valent acid group ”in the present invention. 2 "dispersion was prepared.

  7.08 parts by mass of an anionic surfactant (sodium dodecylbenzenesulfonate: SDS) was dissolved in 2760 parts by mass of ion-exchanged water in a reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction device. An aqueous agent solution was prepared. While stirring the surfactant aqueous solution at a stirring speed of 230 rpm under a nitrogen stream, the temperature was raised to 80 ° C.

On the other hand, the following compound: Styrene 115.1 parts by mass n-butyl acrylate 42.0 parts by mass Methacrylic acid 10.9 parts by mass Monoester compound (1-6) 65.0 parts by mass (CH _3- (CH ₂ ) ₂₀ -COO _{- (CH 2) 21 -CH 3} )
Microcrystalline wax “HNP-0190 (Nippon Seiwa Co., Ltd.)”
7.0 parts by mass was mixed and heated to 80 ° C. for dissolution to prepare a monomer mixed solution.

  Next, while using a mechanical dispersion device having a circulation path, the surfactant aqueous solution heated to 80 ° C. and the monomer mixed solution are mixed and dispersed to obtain an emulsified particle dispersion having a uniform dispersed particle size. Produced.

  Next, a solution prepared by dissolving 0.84 parts by mass of potassium persulfate (KPS) in 200 parts by mass of ion-exchanged water was added, and the polymerization reaction was performed by heating and stirring at 80 ° C. for 3 hours, and then 40 ° C. The solution was cooled to a “resin particle dispersion”.

Furthermore, a solution prepared by dissolving 8.00 parts by mass of potassium persulfate (KPS) and 10.00 parts by mass of 2-chloroethanol in 240 parts by mass of ion-exchanged water was added to the “resin particle dispersion”. After 15 minutes, a mixed liquid composed of the following compounds was added dropwise at 80 ° C. over 120 minutes to the “resin particle dispersion”. That is,
Styrene 383.6 parts by mass n-butyl acrylate 140.0 parts by mass Methacrylic acid 36.4 parts by mass After the completion of dropping, the polymerization reaction was carried out by heating and stirring for 60 minutes, followed by cooling to 40 ° C. Liquid 2 ”was prepared. “Resin particles 2” constituting “resin particle dispersion 2” had a weight average molecular weight of 20,000.

(C) Preparation of “clear toner base particle 1” In a reaction vessel equipped with a stirring device, a temperature sensor, a cooling pipe, and a nitrogen introducing device,
"Resin particles 1" 125 parts by mass (solid content conversion)
"Resin particles 2" 1250 parts by mass (solid content conversion)
2000 parts by mass of ion-exchanged water was added and stirred. After adjusting the temperature in the reaction vessel to 30 ° C., a 5 mol / liter aqueous sodium hydroxide solution was added to adjust the pH to 10.

  Next, an aqueous solution in which 35 parts by mass of magnesium chloride hexahydrate was dissolved in 35 parts by mass of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. The temperature was raised after standing for 3 minutes, and the temperature of the system was raised to 90 ° C. over 60 minutes, and the aggregation and fusion of the particles were continued while maintaining the temperature at 90 ° C. In this state, using “Multisizer 3 (manufactured by Beckman Coulter)”, the particle size of the particles obtained by agglomeration and fusion was measured, and when the volume-based median diameter of the particles became 5.5 μm, An aqueous solution in which 150 parts by mass of sodium was dissolved in 600 parts by mass of ion-exchanged water was added to stop particle aggregation.

  After the flocculation is stopped, “resin particles 1” are added until the average circularity of the flocculated particles becomes 0.965 by using “FPIA2100 (manufactured by Sysmex)” while heating and stirring at a liquid temperature of 98 ° C. as aging treatment Fusion was progressed so that “resin particles 2” were oriented inside the aggregated particles toward the surface of the aggregated particles to form “clear toner base particles 1”.

  Thereafter, the liquid temperature was cooled to 30 ° C., the pH was adjusted to 2 using hydrochloric acid, and stirring was stopped.

  The “clear toner base particle dispersion 1” produced through the above steps is subjected to solid-liquid separation with a basket-type centrifuge “MARKIII model number 60 × 40 (manufactured by Matsumoto Kikai Co., Ltd.)” to obtain “clear toner base particle 1”. A wet cake was formed.

  This wet cake was washed with ion exchange water at 45 ° C. until the electric conductivity of the filtrate reached 5 μS / cm with the basket type centrifuge, and then transferred to “Flash Jet Dryer (manufactured by Seishin Enterprise Co., Ltd.)”. Then, a “clear toner base particle 1” was produced by performing a drying process until the water content became 0.5 mass%.

(D) External Addition Treatment “Clear Toner 1” is produced by adding the following external additive to the produced “clear toner base particle 1” and performing an external addition treatment with a Henschel mixer (Mitsui Miike Mining Co., Ltd.). did.

Silica treated with hexamethylsilazane (average primary particle size 12 nm)
1.0 part by mass n-octylsilane-treated titanium dioxide (average primary particle size 20 nm)
0.3 parts by mass The external addition treatment by the Henschel mixer was performed under the conditions of a peripheral speed of the stirring blade of 35 m / second, a treatment temperature of 35 ° C., and a treatment time of 15 minutes.

(2) Production of “Clear Toner 2” Instead of “Resin Particle 1” and “Resin Particle 2” used in the production of “Clear Toner 1”, “Resin Particle 11” and “Resin” produced by the following procedure were used. A “clear toner 2” was prepared in the same procedure except that the “particle 21” was used. “Resin particles 11” were prepared in the same procedure except that “itaconic acid” used in the preparation of “resin particles 1” was changed to “maleic acid”.

“Resin particles 21” are prepared by changing “methacrylic acid” used in the production of “resin particles 2” to “acrylic acid”, “monoester compound (1-6)”,
"Monoester Compound (1-1)"
_{CH 3 - (CH 2) 12} -COO- (CH 2) 13 -CH 3
In addition, “microcrystalline wax” is prepared by changing to isoparaffin wax “EMW-0001 (manufactured by Nippon Seiwa Co., Ltd.)”. In addition, it was 39 degreeC when melting | fusing point of the said "monoester compound (1-1)" was measured by the above-mentioned method.

(3) Production of “Clear Toner 3” Instead of “Resin Particle 1” and “Resin Particle 2” used in the production of “Clear Toner 1”, the above “Resin Particle 11” was produced in the following procedure. “Clear toner 3” was prepared in the same procedure except that “resin particles 22” were used.

“Resin particle 22” is obtained by replacing “monoester compound (1-6)” used in the production of “resin particle 2” with “monoester compound (1-8)”.
_{CH 3 - (CH 2) 25} -COO- (CH 2) 29 -CH 3
Other than the above, the same procedure as that for “resin particle 2” was used. In addition, it was 90 degreeC when melting | fusing point of the said "monoester compound (1-8)" was measured by the above-mentioned method.

(4) Production of “Clear Toner 4” In place of “Resin Particles 2” used in the production of “Clear Toner 1”, “Resin Particles 23” produced in the following procedure was used in the same procedure. “Clear toner 4” was produced.

“Resin particle 23” is the same as “monoester compound (1-6)” used in the production of “resin particle 2”.
_{CH 3 - (CH 2) 12} -COO- (CH 2) 12 -CH 3
In addition, “microcrystalline wax” was prepared in the same procedure as “resin particle 2” except that it was changed to isoparaffin wax “EMW-0001 (manufactured by Nippon Seiwa Co., Ltd.)”.

(5) Preparation of “Clear Toner 5” Instead of “Resin Particle 2” used in the preparation of “Clear Toner 1”, “Resin Particle 24” prepared in the following procedure was used, and the same procedure was used. Clear toner 5 "was produced.

The “resin particles 24” are “monoester compounds (1-6)” used in the production of “resin particles 2”, and the following “monoester compounds (1-12)”.
_{CH 3 - (CH 2) 29} -COO- (CH 2) 29 -CH 3
In addition, “microcrystalline wax” was prepared in the same procedure except that it was changed to isoparaffin wax “EMW-0001 (manufactured by Nippon Seiwa Co., Ltd.)”.

(6) Preparation of “Clear Toner 6” In place of “Resin Particle 2” used in the preparation of “Clear Toner 1”, “Resin Particle 25” prepared in the following procedure was used, and the same procedure was used. Clear toner 6 "was produced.

“Resin particles 25” are the same as “monoester compounds (1-3)” used in the production of “resin particles 2”.
_{CH 3 - (CH 2) 16} -COO- (CH 2) 17 -CH 3
Other than the above, the same procedure as that for “resin particle 2” was used. In addition, it was 55 degreeC when melting | fusing point of the said "monoester compound (1-3)" was measured by the above-mentioned method.

(7) Production of “Clear Toner 7” Instead of “Resin Particle 1” and “Resin Particle 2” used in the production of “Clear Toner 1”, the above “Resin Particle 11” was produced in the following procedure. “Clear toner 7” was prepared in the same procedure except that “resin particles 26” were used.

“Resin particles 26” are “methacrylic acid” used in the production of “resin particles 2” as “acrylic acid”, and “monoester compound (1-6)” is “monoester compound (1-4)” below.
_{CH 3 - (CH 2) 16} -COO- (CH 2) 21 -CH 3
In addition, “microcrystalline wax” was changed to isoparaffin wax “EMW-0001 (manufactured by Nippon Seiwa Co., Ltd.)”, and was produced in the same procedure as “resin particle 2”.

(8) Production of “Clear Toner 8” Instead of “Resin Particle 1” and “Resin Particle 2” used in the production of “Clear Toner 1”, “Resin Particle 12” and “Resin” produced by the following procedure are used. “Clear toner 2” was prepared in the same procedure except that Particle 27 ”was used. The “resin particles 12” were obtained by using 50.0 parts by mass of “itaconic acid” in the production of “resin particles 1” and using 25.0 parts by mass of “itaconic acid” and “maleic acid”, respectively. Other than the changes, the same procedure was used.

  “Resin particles 27” were produced in the same procedure except that “methacrylic acid” used in the production of “resin particles 2” was changed to “acrylic acid”.

(9) Preparation of “Clear Toner 9” Instead of “Resin Particle 1” used in the preparation of “Clear Toner 1”, “Resin Particle 13” prepared in the following procedure was used. Clear toner 9 ”was prepared. “Resin particles 13” were prepared in the same procedure except that “fumaric acid” was used instead of “itaconic acid” used in the preparation of “resin particle 1”.

(10) Preparation of “Clear Toner 10” “Resin Particle 14” prepared in the following procedure was used instead of “Resin Particle 1” used in the preparation of “Clear Toner 1”. Clear toner 10 "was produced. “Resin particles 14” used in the preparation of “resin particles 1” were changed from 50.0 parts by mass of “itaconic acid” to 25.0 parts by mass of “itaconic acid” and “fumaric acid”. The others were made in the same procedure.

(11) Production of “Clear Toner 11” “Resin Particle 28” produced in the following procedure was used instead of “Resin Particle 2” used in the production of “Clear Toner 1”. Clear toner 11 "was produced.

  “Resin particle 28” was the same procedure except that “cinnamic acid” and “acrylic acid” were added in equal amounts instead of “methacrylic acid” used in the preparation of “resin particle 2”. It was produced.

(12) Preparation of “Clear Toner 12” In place of “Resin Particles 2” used in the preparation of “Clear Toner 1”, “Resin Particles 29” prepared in the following procedure was used in the same procedure. Clear toner 12 "was produced.

  “Resin particles 29” were prepared by changing “methacrylic acid” used in the production of “resin particle 2” to “acrylic acid” and “monoester compound (1-6)” to a monoester compound having the following structure. The same procedure was used.

Monoester compound _{CH 3 - (CH 2) 9} -COO- (CH 2) 11 -CH 3
(13) Preparation of “Clear Toner 13” Instead of “Resin Particle 1” and “Resin Particle 2” used in the preparation of “Clear Toner 1”, the above “Resin Particle 11” was prepared in the following procedure. “Clear toner 13” was prepared in the same procedure except that “resin particle 30” was used.

  The “resin particle 30” was produced by the same procedure except that the “monoester compound (1-6)” used in the production of the “resin particle 2” was changed to a monoester compound having the following structure.

Monoester compound _{CH 3 - (CH 2) 30} -COO- (CH 2) 31 -CH 3
(14) Production of “Clear Toner 14” Instead of “Resin Particle 1” and “Resin Particle 2” used in the production of “Clear Toner 1”, “Resin Particle 15” and “Resin” produced by the following procedure are used. “Clear toner 14” was prepared in the same procedure except that the “particle 31” was used. “Resin particles 15” were prepared in the same procedure except that “Resin particles 1” were changed to “Methacrylic acid” instead of “Itaconic acid”. The “resin particles 31” were produced in the same procedure except that “methacrylic acid” used in the production of “resin particles 2” was changed to “acrylic acid”.

(15) Production of “Clear Toner 15” “Resin Particles 32” produced in the following procedure was used in place of “Resin Particles 2” used in the production of “Clear Toner 1”. Clear toner 15 "was prepared.

  “Resin particle 32” was prepared in the same procedure except that it was changed to paraffin wax “HNP-57 (manufactured by Nippon Seiwa Co., Ltd.)” instead of “microcrystalline wax” used in the preparation of “resin particle 2”. It is a thing.

(16) Production of “Clear Toner 16” A clear toner disclosed in Japanese Patent Application Laid-Open No. 2002-341619 (Patent Document 2) was produced by the following procedure. That is, after thoroughly mixing the following compounds with a “Henschel mixer (Mitsui Miike Mining Co., Ltd.)”, a biaxial extrusion kneader “PCM-30 (manufactured by Ikekai Tekko Co., Ltd.)” with the discharge part removed was used. And then cooled after melt kneading.

Polyester resin (terephthalic acid / bisphenol A ethylene oxide adduct / linear polyester resin obtained from cyclohexanedimethanol (molar ratio = 5: 4: 1))
100 parts by mass Pentaerythritol behenate 6 parts by mass Charge control agent (boron dibenzylate) 1 part by mass The obtained kneaded product was cooled with a cooling belt and then coarsely pulverized with a feather mill. Thereafter, the pulverization is carried out with a mechanical pulverizer “KTM (manufactured by Kawasaki Heavy Industries, Ltd.)” to an average particle size of 9 to 10 μm. Grinding and coarse powder classification were performed until the thickness became 5 μm. Then, using the rotor type classifier (Teplex type classifier type “100ATP (manufactured by Hosokawa Micron Corporation))” from the coarse powder classifier, the “clear toner base particle 16” having a volume-based median diameter of 5.5 μm. Was made.

  The following external additives were added to the produced “clear toner base particles 16” and subjected to external addition treatment with a Henschel mixer (manufactured by Mitsui Miike Mining Co., Ltd.) to produce “clear toner 16”.

Silica treated with hexamethylsilazane (average primary particle size 12 nm)
1.0 part by mass n-octylsilane-treated titanium dioxide (average primary particle size 20 nm)
0.3 parts by mass The external addition treatment by the Henschel mixer was performed under the conditions of a peripheral speed of the stirring blade of 35 m / second, a treatment temperature of 35 ° C., and a treatment time of 15 minutes.

  By the above procedure, “clear toners 1 to 16” were prepared. The divalent or higher valent acidic group monomers, monovalent acidic group monomers, monoester compounds, and hydrocarbon compounds used in preparing “Clear Toners 1 to 16” are shown in Table 1 below.

The number of carbon atoms in terms of monoester compound in the table are those of the general formula R ¹ a hydrocarbon group representing monoester compound represented by -COO-R ² R ¹ and R ² represent a carbon number . For example, the monoester compound used in “Clear Toner 1” has a carbon number column of “21-22”, but is composed of a hydrocarbon group R ¹ having 21 carbon atoms and a hydrocarbon group R ² having 22 carbon atoms. Means that.

2. Evaluation experiment 2-1. Preparation of Clear Toner Developer A ferrite carrier having a volume average particle size of 40 μm formed by coating a methyl methacrylate resin is mixed with the “clear toners 1 to 16” so that the clear toner concentration is 6% by mass, “Clear toner developers 1 to 16” in the form of two-component developers were prepared.

2-2. Evaluation Experiment (1) Evaluation Conditions The above-described “clear toner developers 1 to 16” are mounted on the gloss applying device 1 having the configuration shown in FIG. The gloss applying device 1 was set to the conditions described later so as to form a toner layer. A commercially available “OK top coat + (basis weight 157 g / m ² , paper thickness 131 μm)” (manufactured by Oji Paper Co., Ltd.) was used as the transfer material. In addition, the image forming apparatus used for image output uses commercially available products (a) to (c) below, and 30,000 sheets of transfer materials for evaluation are produced from each image forming apparatus in total, Continuous operation of 90,000 sheets was performed with the gloss applying device 1. Here, what was evaluated using “clear toners 1 to 11” satisfying the configuration of the present invention were evaluated using “Examples 1 to 11” and “clear toners 12 to 16” deviating from the configuration of the present invention. What performed this was made into the "comparative examples 1-5."

The used image forming apparatus is as follows. That is,
(A) Electrophotographic method: “bizhub C353 (manufactured by Konica Minolta Business Technologies, Inc.)”
(B) Inkjet system: “Inkjet printer PX-5800 (manufactured by Seiko Epson Corporation)”
(C) Plate making method: “RISO Digital Screen Plate Making Machine SP400D (made by Riso Kagaku Co., Ltd.)”
In the above-described continuous operation by the gloss imparting device 1, the printed matter was supplied to the gloss imparting device 1 so that the printed matter produced by each image forming apparatus continuously formed a clear toner layer one by one. The above-mentioned “continuous prints produced by each image forming apparatus one by one” means, for example, in order of electrophotographic prints → inkjet prints → plate making prints →. This means that the printed materials output by the device are arranged one by one.

The gloss applying device 1 in FIG. 1 is set to the following specifications. That is,
(A) Clear toner development amount: 4 g / m ²
(B) Belt member material: a PFA layer (thickness 10 μm) disposed on a polyimide film (thickness 50 μm) (c) Belt member surface roughness (initial surface roughness): Ra 0.4 μm
(D) Heating and pressure roll specifications-Heating roll: aluminum base with an outer diameter of 100 mm and a thickness of 10 mm-Pressure roll: silicone rubber layer with a thickness of 3 mm on an aluminum base with an outer diameter of 80 mm and a thickness of 10 mm・ Halogen lamps are placed inside the heating roll and pressure roll, respectively, and the roll surface temperature is set to 155 ° C for the heating roll and 115 ° C for the pressure roll (temperature control by a thermistor)
・ Nip width between heating roll and pressure roll: 11mm
(E) Transfer material temperature at peeling roll position: set to 50 ± 5 ° C. (f) Distance from heating and pressure roll nip to peeling roll position: 620 mm
(G) Transfer material conveyance speed: 220 mm / sec (h) Transfer material conveyance direction: A3 size transfer material is conveyed in the vertical direction (i) Evaluation environment: normal temperature and normal humidity environment (temperature 20 ° C., relative humidity 50%) RH)
(2) Evaluation Items When the continuous operation of 90,000 sheets by the gloss imparting apparatus 1 of FIG. 1 is started, about 60,000 sheets are visually evaluated for the deterioration state of the belt surface at the final time, and are produced by each image forming apparatus. The image clarity of the glossy surface formed on the surface of the clear toner layer formed on the image was quantitatively evaluated by the image clarity C value described later.

<Deterioration of belt surface>
○: Level where the presence of cracks and scratches cannot be confirmed by either visual observation or tactile sensation with the index finger △: The presence of cracks or scratches cannot be confirmed visually, but the presence of small cracks or scratches can be confirmed by the tactile sense of the index finger Level x: Level at which the presence of cracks and scratches can be confirmed visually <Evaluation of image clarity>
“Image clarity” was evaluated by the following procedure. Here, “image clarity” is a method for evaluating the glossiness. When an image is projected on the surface of the clear toner layer by adjusting light, how clear the projected image is without distortion. This is a quantitative evaluation of whether or not Specifically, evaluation is performed by a numerical value defined by a percentage called a mapping C value by a measuring device called a TM type imaging measuring device, and the higher the mapping C value, the better the glossiness. . FIG. 5 shows the principle of the image clarity C value measurement by the TM image clarity measurement apparatus.

  In this evaluation, an optical comb image having a width of 2 mm projected on the surface of the clear toner layer formed by the gloss applying device shown in FIG. 1 on the image formed on the transfer material by the image forming device was used. Was calculated and evaluated. Specifically, using a commercially available TM type image clarity measuring device “ICM-1T (manufactured by Suga Test Instruments Co., Ltd.)”, a 45 degree image clarity C value is obtained with an optical comb having a measurement angle of 45 ° and a width of 2 mm. Measurement, calculation, and evaluation were performed according to the following criteria. The measurement using the TM-type image measuring device is performed with a measurement hole of 20 mm and a power supply capacity of single phase 100 V, 2 A, and a blackboard glass “OPTIC STANDARDS (reflection measurement 45 ° / 60 °) as a reference plate for managing the measurement device. (Suga Test Instruments Co., Ltd.) ”was calibrated.

  A 45-degree image clarity C value of 40 or more was evaluated as acceptable, particularly, those of 70 or more were evaluated as excellent, and those of 60 or more and less than 70 were evaluated as satisfactory.

  The results are shown in Table 2.

  As is clear from the results in Table 2, all of “Examples 1 to 11” using “Clear toners 1 to 11” satisfying the configuration of the present invention are in a state in which the deterioration of the belt member surface has progressed. It was confirmed that the formed clear toner layer can maintain a good level of image clarity C value. In “Examples 1 to 11”, good results were obtained for a transfer material on which an image was formed by any of the image forming methods of the electrophotographic method, the ink jet method, and the plate making method. On the other hand, in “Comparative Examples 1 to 5” using “Clear toners 12 to 16” that deviate from the configuration of the present invention, the image clarity C value of the clear toner layer is remarkably lowered as the belt member surface deteriorates. As a result, the effects obtained in “Examples 1 to 11” could not be reproduced.

DESCRIPTION OF SYMBOLS 1 Gloss imparting apparatus 10 Heating and pressing apparatus 101 Heating roll 102 Pressing roll 103 Peeling roll 104 Follower roll 11 Belt member 12, 13 Cooling fan 14 Conveyance auxiliary roll 2 Image forming apparatus 20S Clear toner supply unit 20Y, 20M, 20C, 20Bk Image forming unit 21 (21S, 21Y, 21M, 21C, 21Bk) Photoconductor 22 (22S, 22Y, 22M, 22C, 22Bk) Charging device 24 (24S, 24Y, 24M, 24C, 24Bk) Developing device 25 (25S, 25Y) 25M, 25C, 25Bk) Cleaning device 26 Intermediate transfer belt 27 (27S, 27Y, 27M, 27C, 27Bk) Primary transfer roll 30S, 30Y, 30M, 30C, 30Bk Exposure unit 50 Fixing device P Transfer material A TM type mapping Performance measuring device A1 lamp A2 Slit A3 Collimator lens A4 Imaging lens A5 Optical pattern (optical comb)
A6 Receiver A7 Motor S Sample

Claims (3)

At least clear toner is supplied to the transfer material on which the image is formed, and the transfer material supplied with clear toner is in close contact with the belt, and then the clear toner is heated and then cooled to clear the transfer material. A clear toner used in an image forming method including a step of forming a toner layer,
The clear toner is at least
A resin obtained from a radical polymerizable monomer containing a radical polymerizable monomer having an acidic group having a valence of 2 or more;
A resin obtained from a radical polymerizable monomer that does not contain a radical polymerizable monomer having a divalent or higher acid group;
A monoester compound represented by the following general formula (1);
A clear toner comprising a hydrocarbon compound having at least one of a branched chain structure and a cyclic structure.
Formula ^{(1): R 1 -COO-} R 2
[Wherein, R ¹ and R ² are each a hydrocarbon group having 13 to 30 carbon atoms, and each may have a substituent, may not have a substituent, or may be the same. It can be different. ]   The clear toner according to claim 1, wherein the monoester compound represented by the general formula (1) has a melting point of 39 ° C. or higher and 90 ° C. or lower. at least,
Supplying clear toner to a transfer material on which an image is formed;
A step of closely contacting the transfer material supplied with the clear toner to the belt, and heating the clear toner in this state;
A step of cooling the transfer material after heating;
By separating the cooled transfer material from the belt,
An image forming method for forming a clear toner layer on the transfer material,
The clear toner used in the image forming method is at least,
A resin obtained from a radical polymerizable monomer containing a radical polymerizable monomer having an acidic group having a valence of 2 or more;
A resin obtained from a radical polymerizable monomer that does not contain a radical polymerizable monomer having a divalent or higher acid group;
A monoester compound represented by the following general formula (1);
An image forming method comprising a hydrocarbon compound having at least one of a branched chain structure and a cyclic structure.
General formula (1): R < ¹ > -COO-R < ² >
[Wherein, R ¹ and R ² are each a hydrocarbon group having 13 to 30 carbon atoms, and each may have a substituent, may not have a substituent, or may be the same. It can be different. ]

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