JP2005077803A - Electrophotographic transfer paper and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic transfer paper which ensures uniform glossiness of toner image part, and to provide an image forming method. <P>SOLUTION: The electrophotographic transfer paper has a thermoplastic resin layer as a toner image receiving layer on one or both sides of coated paper which has a coating layer of adhesive and pigments as the main constituents. In the transfer paper, the toner image receiving image has a boiling point of not lower than 135°C but not higher than 350°C and a melting point of not higher than 120°C and contains a constituent extracted from plant. The image forming method uses the electrophotographic transfer paper. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrophotographic transfer paper capable of obtaining a uniform glossy color image by an electrophotographic method applied to a color copying machine or a color printer, and a color image forming method using the same.

  As a method for forming a color image by an electrophotographic method, an electrostatic latent image is formed for each color by irradiating color separation light on a photosensitive material, and the electrostatic latent image for each color is converted into Y (yellow), These toners are successively developed with color toners such as M (magenta) and C (cyan) to form color toner images for each color, and each toner image of each color is superimposed and transferred onto the transfer member. There is a method of forming a color image by heating and fusing and fixing an image. As another method, the color toner image for each color is formed on the photosensitive material instead of the transfer material, and the superimposed color toner image is collectively transferred onto the transfer material, and this is heated and melted. There is a method of forming a color image by fixing. Further, as another method, there is a method in which a color toner image is overlapped between a photosensitive member and a transfer member by using a belt or the like, and then the color toner images are collectively transferred to a transfer member and heated and melted to be fixed. .

The color toner is constituted by dissolving or dispersing various dyes or pigments as a colorant in a binder resin, and the particle diameter thereof is several μm to several tens μm. As the color toner receiver, a paper base such as plain paper, general printing paper, and coated paper is used, and the color toner superimposed on the paper base is heated and melted and fixed. As a result, a color image is formed.
However, since the surface of the color image formed in this way has unevenness of about 10 to 100 μm (see Patent Document 1), the unevenness of the toner layer causes unevenness in the gloss of the image. End up.

  In order to improve this problem, a method is disclosed in which a thermoplastic transparent resin layer is provided on a base material and a toner image is embedded in the transparent resin layer by a heat roller fixing device. Patent Document 2 discloses that a toner image is placed on the surface of an image transfer sheet having a glass transition temperature of 40 to 70 ° C. and having a transparent resin layer made of a cross-linked resin soluble in tetrahydrofuran. A method of embedding in a transparent resin layer is disclosed. Further, Patent Documents 3 and 4 disclose a method in which a toner image is placed on the surface of an image transfer sheet coated with a thermoplastic resin, and the toner is embedded in a transparent resin layer by a belt-like fixing device.

  Further, as a transfer sheet that can obtain gloss matching without gloss unevenness without using a belt-like fixing device, Patent Document 5 discloses the average molecular weight (Mwa) of the transparent resin on the surface of the transfer sheet and the binder resin of the color toner. Transfer for electrophotography having a relationship of Mwa−Mwb ≧ 10000 with the average molecular weight (Mwb), and adjusting the melting inclination angle with the binder resin of the color toner at the fixing temperature of the transparent resin toner to 40 degrees or less. Paper is disclosed, and Patent Document 6 proposes an electrophotographic transfer paper in which the transparent resin layer on the surface of the transfer sheet has a number average molecular weight (Mn) of 5000 to 20000 and a glass transition temperature of 30 to 85 ° C. . Furthermore, Patent Document 7 discloses a method of embedding toner in a thermoplastic resin layer by blending a plasticizer in the thermoplastic resin layer, softening a binder and solid components that form the layer at the time of fixing.

  When the color toner image is fixed on the transfer body, the technology described in each of the above publications is heated and melted by pressurizing the color toner image with a heat roller, and it is placed in the transparent resin layer on the surface of the electrophotographic transfer paper. It is firmly established to be embedded. However, in these methods, the blank paper portion becomes highly smooth and gloss is exhibited, but the unevenness on the surface of the image portion cannot be completely smoothed, resulting in poor glossiness of the image portion.

In order to increase the gloss of the toner image area, the technique described in Patent Document 8 blends a thermoplastic resin layer with a compatibilizing agent (dibutoxyethoxyethyl adipate), and melts the toner in the heat fixing process. A method of raising the value is disclosed. However, the plasticizer blended to soften the thermoplastic resin layer described in Patent Document 7 and the phase blended to increase the gloss of the toner image portion described in Patent Document 8. Solvents are difficult to use due to problems in environmental pollution and environmental safety, which have become a problem in recent years.
JP 63-92965 A Japanese Patent Laid-Open No. 5-127413 JP-A-5-216322 Japanese Patent Laid-Open No. 6-11982 Japanese Patent Laid-Open No. 10-221877 JP-A-11-160905 JP 2000-275891 A JP 2002-341580 A

  An object of the present invention is to solve the above problems. That is, an object of the present invention is to provide an electrophotographic transfer paper having the above-described problems and having a uniform glossy color image.

In such a situation, the present inventors have conducted intensive research, and as a result, have provided a thermoplastic resin layer as a toner image-receiving layer on one side or both sides of a coated paper having a coating layer mainly composed of an adhesive and a pigment. The present invention has found that the above-mentioned problems can be solved by incorporating a plant extract component having a boiling point of 135 ° C. or more and 350 ° C. or less into the toner image-receiving layer. Was completed.
That is, the present invention provides the following.

<1> In a transfer paper having a thermoplastic resin layer as a toner image-receiving layer on one side or both sides of a coated paper having a coating layer mainly composed of an adhesive and a pigment, the toner image-receiving layer has a boiling point of 135 ° C. An electrophotographic transfer paper comprising a plant extract component having a melting point of 350 ° C. or lower and a melting point of 120 ° C. or lower.

<2> The plant extract component is one or more selected from terpenoids, flavonoids, isoflavonoids, stilbenes, phenolic acids, coumarins, quinones, lignans, norlignans and alkaloids. <1> The electrophotographic transfer paper according to <1>.
<3> The electrophotographic transfer paper according to <1> or <2>, wherein the plant extract component is encapsulated in a microcapsule and contained in the toner image-receiving layer.
<4> Two or more toner image-receiving layers, and the uppermost layer is a thermoplastic resin containing a plant extract component, <1>, <2> or <3> Transfer paper for electrophotography.
<5> The electrophotographic transfer paper according to <1>, <2>, or <3>, wherein the toner image-receiving layer has two or more layers, and the uppermost layer is a plant extract component.
<6> The electrophotographic transfer paper according to any one of <1> to <5>, wherein a release agent is further blended in the toner receiving layer.

<7> A step of forming a latent image on a latent image carrier, a step of developing the latent image using an electrophotographic developer, a step of transferring the developed toner image to a transfer target, and the transfer target An image forming method including a fixing step of heat-pressing the above toner image, wherein the transfer target is the electrophotographic transfer paper according to any one of <1> to <6>. Forming method.
<8> The image forming method according to <7>, wherein the toner has a toner shape factor (SF1) represented by the following formula (1) in the range of 100 to 140.
SF1 = (ML ² × π / 4A) × 100 Formula (1)
(In the formula, ML represents the maximum toner length, and A represents the projected area of the toner.)
<9> A toner mixes a resin particle dispersion in which resin particles are dispersed and a colorant dispersion in which a colorant is dispersed, agglomerates the resin particles and the colorant into a toner particle diameter, and the obtained aggregate is a resin. The image forming method according to <7> or <8>, wherein the toner particles are colored toner particles heated to and fused to a temperature equal to or higher than the glass transition point.

  The electrophotographic transfer paper and the image forming method according to the present invention are an electrophotographic transfer paper and an image forming method in which the toner image portion has a uniform high glossiness, and are extremely useful in practice.

  The present invention relates to a transfer paper having a thermoplastic resin layer as a toner image-receiving layer on one side or both sides of a coated paper having a coating layer mainly composed of an adhesive and a pigment. The toner image-receiving layer has a boiling point of 135. An electrophotographic transfer paper comprising a plant extract component having a melting point of 120 ° C. or lower and a melting point of 120 ° C. or lower, and an image forming method using the same. Thereby, it is possible to provide an electrophotographic transfer paper and an image forming method which are excellent in glossiness of the image portion.

Electrophotographic transfer paper <Plant extract component>
In the present invention, the toner image-receiving layer contains a plant extract component having a boiling point of 135 ° C. or higher and 350 ° C. or lower and a melting point of 120 ° C. or lower.

In order to obtain a high gloss image, it is necessary to melt the toner at the time of fixing, and to eliminate unevenness on the image surface by a fixing roll. Normally, when the toner is heated at the time of fixing, the molecular motion in the toner particles increases, and the distance between the molecules increases and the toner becomes soft. In that state, the molecular chain is further expanded by allowing the molecules of the plant extract component to enter, and the molecular chain becomes softer, so that the unevenness of the image surface can be eliminated and gloss is developed. The plant extract component has a boiling point of 135 ° C. or higher, preferably 145 ° C. or higher. If the temperature is lower than 135 ° C., the plant extract component is vaporized by heating at the time of fixing, and the effect of softening the toner becomes low. The melting point is preferably 120 ° C. or lower. If the temperature exceeds 120 ° C., liquefaction does not proceed at the time of fixing, and it is difficult for the thermoplastic resin layer to ooze out.
The plant extract component is a natural component, and is considered to be higher in environmental safety than commonly used plasticizers.

  Examples of plant extract components having the above characteristics include terpenoids, phenolic acids, coumarins, lignans, norlignans, quinones, flavonoids, isoflavonoids, stilbenes, alkaloids and the like. Moreover, what chemically modified these extraction components etc. can be used. Specifically, for example, D-limonene (1), α-pinene (2), menthol (3), methyl salicylate (4), coumarin (5), 1.2-naphthoquinone (6), flavone (7), Stilbene (8), isoquinoline (9) and the like can be used, but not limited thereto.

  The plant extract component is preferably blended in the image receiving layer in an amount of 0.1% by weight to 80% by weight. If it is less than 0.1% by mass, the amount of the image receiving layer that oozes out at the time of fixing is small, and the toner softening effect may be reduced. If the amount is 80% by mass or more, the amount of seepage may be excessive and toner may be flowed during fixing, and the image may be disturbed. In particular, it is desirable that the plant extract component is blended in the image receiving layer in an amount of 10% by mass to 60% by weight.

  Moreover, it is preferable that the plant extract component is encapsulated in microcapsules and blended in the thermoplastic resin layer. By encapsulating in a microcapsule, it becomes possible to distribute the plant extract component on the surface of the image receiving layer rather than coating it with a thermoplastic resin, and the amount of contact between the plant extract component and the toner during fixing increases. Furthermore, the gloss of the image area can be increased.

  Examples of the microencapsulation method include known methods such as a coacervation method, an interfacial polymerization method, and an in-situ polymerization method. Specific examples of the microcapsule wall membrane material include polyurethane, polyurea, polyester, polycarbonate, urea-formaldehyde resin, melamine-formaldehyde resin, polystyrene, styrene-acrylate copolymer, gelatin and the like. As the core material of the microcapsule, the organic synthetic compound that can be used in the present invention is used alone or as a mixture of two or more kinds, or the compound is used as an oil in the field of other high-boiling hydrophobic media such as pressure-sensitive copying paper. In addition, those dissolved in known tricresyl phosphate, dibutyl phthalate, diisopropyl naphthalene and the like can also be used. The average particle size of the microcapsules is usually in the range of 0.2 to 20 μm, but is not particularly limited.

  The toner image-receiving layer may be composed of two or more layers. In the case of two layers, the undercoat layer is a thermoplastic resin layer, and the overcoat layer is a mixed layer of a thermoplastic resin and the plant extract component. It is preferable that the thermoplastic resin layer and the topcoat layer have a configuration in which the plant extract component is directly applied. By having such a configuration in the toner image-receiving layer, it becomes possible to distribute the plant extract component on the surface of the image-receiving layer, increasing the amount of contact between the plant extract component and the toner during fixing, and further increasing the gloss of the image area. be able to.

<Base materials, etc.>
As the base material for the electrophotographic transfer paper of the present invention, synthetic paper, high-quality paper, coated paper, art paper, cast-coated paper, and the like can be used. However, it is preferable to use coated paper, art paper, cast coated paper, etc. in order to prevent the surface property of the substrate from affecting the gloss after fixing and to prevent the occurrence of blisters during fixing. The coated paper used as the substrate is a coated paper having a coating layer obtained by coating a coating liquid mainly composed of an adhesive and a pigment on one side or both sides. As the adhesive for the pigment coating layer, a water-soluble and / or water-dispersible polymer compound is used. For example, cationic starch, amphoteric starch, oxidized starch, enzyme-modified starch, thermochemically-modified starch, esterified starch. , Starches such as etherified starch, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, natural or semi-synthetic polymer compounds such as gelatin, casein, soy protein, natural rubber, polyvinyl alcohol, isoprene, neoprene, polybutadiene, etc. Polyalkylenes such as polydienes, polybutene, polyisobutylene, polypropylene, and polyethylene, vinyl polymers such as vinyl halide, vinyl acetate, styrene, (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylamide, and methyl vinyl ether And copolymers, Len - butadiene, methyl methacrylate - synthetic rubber latex butadiene etc., polyurethane resins, polyester resins, polyamide resins, olefin - maleic acid resins, synthetic polymer compounds such as melamine resins. From these, one or more types are appropriately selected and used according to the quality target of the electrophotographic transfer paper.

  The blending ratio of the adhesive is preferably in the range of 5 to 50 parts by mass with respect to 100 parts by mass of the pigment. If it is less than 5 parts by mass, the surface of the base material is attacked by the resin liquid when the thermoplastic resin layer is applied onto the obtained coating layer, so that it is difficult to obtain good white paper glossiness. . On the other hand, if it exceeds 50 parts by mass, bubbles are generated when the pigment coating layer is applied, and the coated surface becomes rough, so that good white paper glossiness may not be obtained.

  Examples of the pigment used here include heavy calcium carbonate, light calcium carbonate, kaolin, calcined kaolin, structural kaolin, delaminated kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, alumina, magnesium carbonate, and oxidation. Magnesium, silica, magnesium aluminosilicate, particulate calcium silicate, particulate magnesium carbonate, particulate light calcium carbonate, mineral pigments such as white carbon, bentonite, zeolite, sericite, smectite, polystyrene resin, styrene-acrylic copolymer Resin, urea resin, melamine resin, acrylic resin, vinylidene chloride resin, benzoguanamine resin and their fine hollow particles, through-hole type organic pigments, etc. are used, and one or more of these are used .

  In addition to these, various auxiliary agents such as surfactants, pH regulators, viscosity modifiers, softeners, gloss-imparting agents, dispersants, flow modifiers, and antistatic agents are included in the coating liquid for the pigment coating layer. , Stabilizers, antistatic agents, crosslinking agents, antioxidants, sizing agents, fluorescent brighteners, colorants, UV absorbers, antifoaming agents, water-resistant agents, plasticizers, lubricants, preservatives, perfumes, etc. It is also possible to use it appropriately as needed.

The coating amount of the pigment coating layer is appropriately selected according to the purpose of use of the electrophotographic transfer paper of the present invention. And is preferably 8 to 40 g / m ² in terms of dry weight. As a coating method for forming a coating layer, a generally known coating apparatus such as a blade coater, an air knife coater, a roller coater, a reverse roller coater, a bar coater, a curtain coater, a die coater, a gravure coater, a champlex coater, a brush coater, and a two-roller. A size press coater, a bill blade coater, a short dwell coater, a gate roller coater, or the like of a type or metering blade type is appropriately used.

  The pigment coating layer may be formed on one or both sides of the substrate, and the coating layer may have a multilayer structure by providing one layer or two or more intermediate layers as required. In the case of double-sided coating or multi-layer structure, the coating liquids do not have to be the same or the same coating amount, and may be appropriately adjusted according to the required quality level. In addition, when a coating layer is provided on one side of the substrate, a synthetic resin layer, a coating layer made of an adhesive and a pigment, or an antistatic layer is provided on the back side to prevent curling, impart printability, and supply / discharge It is also possible to impart paper suitability and the like. Furthermore, it is of course possible to add various application suitability to the back surface of the substrate by post-processing such as adhesion, magnetism, flame retardancy, heat resistance, water resistance, oil resistance, and anti-slip.

  The substrate having the pigment coating layer of the present invention is finished by adjusting the water content to 3 to 10% by mass, preferably about 4 to 8% by mass in a normal drying process or surface treatment process. It is done.

  Further, in order to perform the smoothing treatment on the base material, a smoothing treatment apparatus such as a normal super calendar, gloss calendar, or soft calendar may be used. Moreover, you may carry out suitably by an on-machine or an off-machine, and the form of a pressurization apparatus, the number of pressurization nips, heating, etc. are suitably adjusted according to a normal smoothing processing apparatus.

  The base paper of the coated paper used as the substrate is not particularly limited. For example, acidic paper having a papermaking pH of about 4.5, weakly acidic to about 6 having a papermaking pH of about 6 containing an alkaline filler such as calcium carbonate as a main component. A paper substrate such as neutral papermaking having 9 weak alkalinity is used. As for the paper making method, a general long-mesh multi-cylinder type, a round net single-cylinder type, a Yankee type, a twin-wire type or the like is appropriately used. Moreover, a synthetic paper, a nonwoven fabric, and a synthetic resin film can also be used according to a use.

<Image receiving layer>
As the thermoplastic resin constituting the image receiving layer, polyester resin, styrene-acrylic acid ester, styrene-methacrylic acid ester and the like can be used, and it is particularly preferable to use polyester resin. The following are illustrated as a polyhydric alcohol component and polyhydric carboxylic acid component which comprise a polyester resin.

  Polyhydric alcohol components include ethylene glycol, propylene glycol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, a monomer obtained by adding olefin oxide to bisphenol A, and the like can be used.

  As the polyvalent carboxylic acid component, maleic acid, maleic anhydride, fumaric acid, phthalic acid, terephthalic acid, isophthalic acid, malonic acid, succinic acid, glutaric acid, dodecyl succinic acid, n-octyl succinic acid, n-dodecyl succinic acid Acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2 -Methyl-2-methylenecarboxypropane, tetra (methylenecarboxy) methane, 1,2,7,8-octanetetracarboxylic acid, trimellitic acid, pyromellitic acid, lower alkyl esters of these acids, and the like can be used. . The polyester resin used in the present invention is synthesized by polymerization of one or more of the polyhydric alcohol components and one or more of the polyvalent carboxylic acid components.

  For application of the image-receiving layer onto the coated paper, generally known coating apparatuses such as a reverse roller coater, a bar coater, a curtain coater, a die coater, and a gravure coater are appropriately used.

Further, the sheet coated with the image receiving layer may be smoothed as necessary, and this smoothing is performed by a smoothing processing device such as a normal super calendar, gloss calendar, soft calendar or the like. Further, the form of the pressure device, the number of pressure nips, heating, and the like are appropriately adjusted according to a normal smoothing apparatus.
In the present invention, the thickness of the image receiving layer is preferably 3 to 20 μm. More preferably, it is 5 to 15 μm. When the thickness of the image receiving layer is less than 3 μm, the toner is not completely buried, the smoothness of the image receiving surface after fixing is deteriorated and a high gloss image may not be obtained, and when the thickness of the image receiving layer exceeds 20 μm, the image receiving layer is received. The softening of the layer hardly occurs and the toner embedding property may be deteriorated.

The image receiving layer preferably has a composition adjusted so that the surface electrical resistance is 8.0 × 10 ⁸ Ω or more at a temperature of 28 ° C. and a relative humidity of 85%. Further, depending on the purpose, pigments, conductive agents, deodorants, antioxidants, ultraviolet absorbers, release agents, etc. may be blended.

  A release agent may be blended in the image receiving layer, and waxes, higher fatty acids, higher alcohols, higher fatty acid amides and the like can be used as the release agent. Examples of waxes include vegetable waxes such as carnauba wax and rice wax, petroleum waxes such as paraffin, microcrystalline, and petrolactam, and synthetic hydrocarbon waxes such as polyethylene wax. Examples of the higher fatty acid include stearic acid, oleic acid, palmitic acid, myristic acid, lauric acid, and examples of the higher alcohol include lauryl alcohol, myristyl alcohol, stearyl alcohol, cetyl alcohol, and behenyl alcohol. Examples of the higher fatty acid amide include stearic acid amide, palmitic acid amide, methylene bisstearyl amide, and ethylene bisstearyl amide. The release agent is preferably blended in an amount of 0.1% to 10% by weight in the image receiving layer. If it is less than 0.1% by mass, the effect as a release agent is insufficient, and it may stick to the heat roller at the time of fixing. If it exceeds 10% by mass, the amount of seepage on the surface of the image receiving layer increases, and the image after fixing is fixed. In some cases, after the release of the release agent may remain on the white paper part.

  Generally, polyester resin or styrene-acrylic resin is mainly used as the resin component of the toner. Therefore, as the thermoplastic resin for forming the transparent resin layer, one having high compatibility with the toner can be selected. preferable. Accordingly, one or a mixture of two or more of polyester resin, styrene-acrylic acid ester resin, styrene-methacrylic acid ester resin and the like is used depending on the purpose.

As a method for producing the toner, any production method such as a pulverization method or a polymerization method may be used. A resin particle dispersion in which resin particles are dispersed and a colorant dispersion in which a colorant is dispersed are mixed to form a resin. A method is preferred in which the particles and the colorant are aggregated to a toner particle size, and the resulting aggregate is heated and fused to a temperature above the glass transition point of the resin.
The toner preferably has a toner shape factor (SF1) represented by the following formula (1) in the range of 100 to 140.

SF1 = (ML ² × π / 4A) × 100 Formula (1)

(In the formula, ML represents the maximum toner length, and A represents the projected area of the toner.)
When the shape factor SF1 exceeds 140, the toner fluidity deteriorates and the transferability from the initial stage is affected. Here, the average value of the toner shape factor SF1 can be calculated as follows, for example. That is, with respect to the toner scattered on the slide glass, the optical micrograph is taken into a Luzex image analyzer through a video camera, and the toner shape factor SF1 of 100 or more toners is calculated to obtain an average value.

  In the present invention, the volume average particle diameter of the toner is preferably in the range of 2 to 8 μm, and more preferably in the range of 3 to 7 μm. When the volume average particle diameter of the toner is less than 2 μm, the chargeability tends to be insufficient and the developability may be deteriorated. On the other hand, when it exceeds 7 μm, the resolution of the image may be deteriorated. Therefore, it is not preferable respectively.

  Here, the volume average particle diameter of the toner means a particle diameter at which the cumulative volume becomes 50% from the small diameter side. For example, Coulter Counter TA-II (manufactured by Nikka Kisha Co., Ltd.), Multisizer II (manufactured by Nikka Kisha Co., Ltd.). ) Or the like.

  The particle size distribution of the toner is preferably such that the volume average particle size distribution GSDv is 1.28 or less, more preferably 1.25 or less. A sharp toner can be obtained. If GSDv exceeds 1.28, the sharpness and resolution of the image are lowered, which is not preferable.

Here, the average particle size distribution index GSDv of the toner is a ratio (D _84v / D _16v ) of the particle diameter D _16v at which the cumulative volume is 16% to the particle diameter D _84v at which the cumulative volume is 84% from the small diameter side. It refers to the square root and can be measured using the same device as the volume average particle diameter.

The electrostatic image developer is not particularly limited except that it contains a toner, and can have an appropriate component composition depending on the purpose.
When the toner is used alone, the electrostatic image developer is prepared as a one-component electrostatic image developer, and when used in combination with a carrier, the toner is prepared as a two-component electrostatic image developer.

The carrier used as the two-component electrostatic image developer is not particularly limited, and examples thereof include resin-coated carriers described in JP-A Nos. 62-39879 and 56-11461. A known carrier can be used.
The mixing ratio of the toner and the carrier in the electrostatic image developer is not particularly limited and can be appropriately selected depending on the purpose.

<Image forming method>
The image forming method of the present invention is characterized by using the electrophotographic transfer paper of the present invention. The image forming method of the present invention includes a known image forming step, for example, a step of forming a latent image on a latent image carrier, a step of developing the latent image using an electrophotographic developer, and a development process. Including a step of transferring the toner image onto the transfer member and a step of fixing the toner image on the transfer member; and as another method, an intermediate belt or the like is provided between the photosensitive member and the transfer member. For example, a method of superimposing the color toner images and then transferring the color toner images to the transfer member and fixing them by heating and melting may be employed.

  FIG. 1 is a schematic configuration diagram showing an example of an image forming apparatus preferably used in the image forming method of the present invention. The image forming apparatus shown in FIG. 1 includes a photoconductor 11, and around the photoconductor 11, a roller-type charger 12, an exposure device 13, and a developer 14a mounted with cyan, magenta, yellow, and black developers. , 14b, 14c, 14d, a belt-like intermediate transfer member 15, a cleaner 16, and a light static eliminator 17 are arranged in this order. The intermediate transfer member 15 is stretched around support shaft rollers 18a, 18b, and 18c. The support roller 18 a is in pressure contact with the photoreceptor 11 via the intermediate transfer member 15. The support roller 18 c is pressed against the transfer roller 19 via the intermediate transfer member 15. Further, a heat roller fixing device including a heating roller 1 and a pressure roller 2 for fixing the toner image transferred to the transfer medium 7 by the transfer roller 19 is provided.

  An image is formed as follows using the image forming apparatus shown in FIG. The photosensitive member 11 charged by the charger 12 is exposed by the exposure device 13 based on each image information of cyan, magenta, and yellow to form a latent image on the photosensitive member 11. The latent image on the photoconductor 11 is developed by developing devices 14a, 14b, 14c, and 14d built in the developing device 14 to form toner images. The developed toner image is transferred onto the belt-like intermediate transfer member 15. The toner image on the intermediate transfer member 15 moves to between the support roller 18c and the transfer roller 19 that is in pressure contact with the intermediate transfer member 15 as the intermediate transfer member 15 advances in the arrow P direction. . When the toner image on the intermediate transfer member 15 passes between the support roller 18c and the transfer roller 19 that is in pressure contact with the intermediate transfer member 15 (nip portion), the toner image inserted through the nip portion is inserted. Transferred onto the transfer body 20. The toner image transferred onto the transfer target 20 is fixed on the transfer target 20 by passing the transfer target 20 between the heating roller 1 and the pressure roller 2 to form an image. The toner image remaining on the photoconductor 11 after the toner image on the photoconductor 11 is transferred to the transfer target 20 is removed by the cleaner 16, and the residual charge remaining on the photoconductor 11 is removed by the photocharger 17. The charge is removed, and the next image formation is prepared.

  As the fixing device used in the image forming method of the present invention, a contact-type heat fixing device can be used. For example, a heating roller having a rubber elastic layer on a cored bar and, if necessary, a fixing member surface layer, a core A heat roller fixing device comprising a pressure roller having a rubber elastic layer on gold and optionally having a fixing member surface layer, a combination of the roller and the roller, a combination of the roller and the belt, a belt, A fixing device in place of the combination with the belt can be used.

  For the base material (core) of the fixing member, a material having excellent heat resistance, strong strength against deformation, and good thermal conductivity is selected. In the case of a roller type fixing device, for example, aluminum, iron, copper, etc. In the case of a belt-type fixing device, for example, a polyimide film, a stainless steel belt, or the like is selected. On the surface of the roller-type substrate, an elastic rubber layer usually made of silicone rubber, fluorine rubber or the like is provided on the surface.

  The fixing member may contain various additives according to the purpose, for example, carbon black, metal oxide, ceramic particles such as SiC, etc. for the purpose of improving wear resistance and controlling resistance. May be.

  The fixing process using the transfer medium of the present invention will be described in detail with reference to FIG. The thermocompression bonding apparatus shown in FIG. 2 is an apparatus in which the fixing member has a roller shape, and includes a heat roller 1, a pressure roller 2 disposed to face the heat roller 1, a heating source 3 for heating the heat roller 1, and a heat. And a fixing member surface layer 4 on the surface of the roller 1. An elastic layer 5 is formed on the surface of the heat roller 1. When the transfer body 7 on which the toner image 6 is formed passes between the pressure roller 2 and the heat roller 1, the image is fixed by being heated and pressed.

  2 further includes a cleaning member for removing toner adhering to the surface of the heat roller 1, a heating source 3 for heating the pressure roller 2, and a recording material as the heat roller 1. You may have the nail | claw (finger) etc. to peel from. The heating source 3 in the thermocompression bonding apparatus shown in FIG. 2 is controlled by a temperature control apparatus (not shown).

  The heat roller 1 and / or the pressure roller 2 are preferably provided with an elastic layer 5 having a single layer or a laminated structure. The thickness of the elastic layer is preferably 0.1 to 3 mm, and 0.5 to 2 mm. More preferred. The elastic layer 5 is made of heat-resistant rubber such as silicone rubber or fluorine rubber, and the rubber hardness is preferably 60 or less. The fixing member having the elastic layer 5 is advantageous in that the fixing member is deformed following the unevenness of the toner image 6 on the transferred body 7 and the smoothness of the image surface after fixing can be improved. is there. If the thickness of the elastic layer exceeds 3 mm, the heat capacity of the fixing member is increased, and it takes a long time to heat the fixing member to a desired temperature, and energy consumption is also increased. Absent. On the other hand, if the thickness of the elastic layer is less than 0.1 mm and is too thin, the deformation of the fixing member cannot follow the unevenness of the toner image, melting unevenness occurs, and distortion of the elastic layer effective for peeling cannot be obtained. It is not preferable in terms.

  Since the image forming method of the present invention uses the electrophotographic transfer paper of the present invention, a uniform glossy color image can be obtained.

  The present invention will be described more specifically with reference to the following examples, but of course the scope of the present invention is not limited thereto. In the examples, “parts” and “%” indicate “parts by mass” and “% by mass” unless otherwise specified.

Example 1
The following materials are mixed in 400 parts by mass of a toluene solution on the glossy surface of a commercially available cast coated paper (mirror coated gold, manufactured by Oji Paper Co., Ltd.) having a basis weight of 157 g / m ² and dissolved in a 50 ° C. warm bath. A coating solution was prepared and coated using a bar coater so that the coating thickness was 10 μm, and a transfer paper for electrophotography having a basis weight of 167 g / m ² was obtained.
[Resin layer]
Thermoplastic resin: polyester resin (TP220, manufactured by Nippon Synthetic Chemical Co., Ltd.) 100 parts by mass Plant extract component: D-limonene (melting point-96.6 ° C., boiling point 176 ° C., manufactured by Yashara Chemical Co., Ltd.) 10 parts by mass Release agent: Carnava 3 parts by weight of wax (manufactured by Toa Kasei Co., Ltd.)

Example 2
A coating solution having the following contents was prepared, and the topcoat layer and the undercoat layer were coated using a bar coater so that the coating thickness was 5 μm, respectively, and an electrophotographic transfer paper having a basis weight of 167 g / m ² was obtained.
[Overcoat layer]
Thermoplastic resin: polyester resin (TP220, manufactured by Nippon Synthetic Chemical Co., Ltd.) 100 parts by mass Plant extract component: D-limonene (melting point-96.6 ° C., boiling point 176 ° C., manufactured by Yashara Chemical Co., Ltd.) 10 parts by mass Release agent: Carnava Wax (manufactured by Toa Kasei Co., Ltd.) 3 parts by mass [undercoat layer]
Thermoplastic resin: Polyester resin (TP220, manufactured by Nippon Synthetic Chemical Co., Ltd.) 100 parts by mass Release agent: Carnauba wax (manufactured by Toa Kasei Co., Ltd.) 3 parts by mass

Example 3
An electrophotographic transfer paper was obtained in the same manner as in Example 1 except that the plant extract component (D-limonene) was encapsulated in a microcapsule as described below and blended in the thermoplastic resin layer.
Preparation of microcapsules To a mixed solution of 21 parts of an aqueous solution in which 1 part of urea and 0.1 part of resorcin were dissolved and 10 parts of a 10% ethylene-maleic anhydride copolymer aqueous solution, a 20% aqueous sodium hydroxide solution was added to adjust the pH to 3 .5. Next, 10 parts of D-limonene was added to this aqueous solution to emulsify to an average particle size of 5.0 μm, and 2.5 parts of 37% formaldehyde aqueous solution was further added, and then the temperature of the system was brought to 70 ° C. and stirred for 4 hours. A capsule dispersion was obtained. Subsequently, the dispersion was spray-dried to obtain powder capsules having an average particle size of 6.8 μm.

Example 4
An electrophotographic transfer paper was obtained in the same manner as in Example 1 except that α-pinene (melting point: −62 ° C., boiling point: 155 ° C., manufactured by Yasuhara Chemical Co., Ltd.) was used as a plant extract component.

Example 5
An electrophotographic transfer paper was obtained in the same manner as in Example 4 except that a polyester resin (Tuffton NE382, manufactured by Kao Corporation) was used as the thermoplastic resin.

Example 6
An electrophotographic transfer paper was obtained in the same manner as in Example 5 except that the coating thickness of the thermoplastic resin layer was 20 μm.

Example 7
An electrophotographic transfer paper was obtained in the same manner as in Example 5 except that menthol (melting point: 43 ° C., boiling point: 216 ° C., manufactured by Takasago International Corporation) was used as a plant extract component.

Example 8
Prepare a coating solution with the following contents, and coat the topcoat layer and the undercoat layer with a bar coater so that the coating thickness is 1 μm for the topcoat layer and 9 μm for the basecoat layer, respectively, for electrophotography with a basis weight of 167 g / m ² A transfer paper was obtained.
[Overcoat layer]
Plant extract component: Menthol (melting point 43 ° C, boiling point 216 ° C, manufactured by Takasago International Corporation) 100 parts by weight Release agent: Carnauba wax (manufactured by Toa Kasei Co., Ltd.) 3 parts by weight [undercoat layer]
Thermoplastic resin: Polyester resin (Toughton NE382, manufactured by Kao Corporation) 100 parts by mass Release agent: Carnauba wax (manufactured by Toa Kasei Co., Ltd.) 3 parts by mass

Example 9
An electrophotographic transfer paper was obtained in the same manner as in Example 5 except that methyl salicylate (melting point: −8.6 ° C., boiling point: 220 ° C.) was used as a plant extract component.

Example 10
An electrophotographic transfer paper was obtained in the same manner as in Example 5 except that coumarin (melting point: 71 ° C., boiling point: 291 ° C.) was used as a plant extract component.

Example 11
An electrophotographic transfer paper was obtained in the same manner as in Example 5 except that stilbene (melting point: 120 ° C., boiling point: 306 ° C.) was used as a plant extract component.

Example 12
An electrophotographic transfer paper was obtained in the same manner as in Example 5 except that isoquinoline (melting point: 26 ° C., boiling point: 242 ° C.) was used as the plant extract component.

Comparative Example 1
A coating solution having the following contents was prepared, and an electrophotographic transfer paper was obtained in the same manner as in Example 1.
[Resin layer]
Thermoplastic resin: Polyester resin (TP220, manufactured by Nippon Synthetic Chemical Co., Ltd.) 100 parts by mass Release agent: Carnauba wax (manufactured by Toa Kasei Co., Ltd.) 3 parts by mass

Comparative Example 2
A coating solution having the following contents was prepared, and an electrophotographic transfer paper was obtained in the same manner as in Example 1.
[Resin layer]
Thermoplastic resin: Polyester resin (Tufton NE382, manufactured by Kao Corporation) 100 parts by weight Release agent: Carnauba wax (manufactured by Toa Kasei Co., Ltd.) 3 parts by weight

Comparative Example 3
Evaluation was performed using a commercially available cast-coated paper having a basis weight of 157 g / m ² (mirror-coated platinum, manufactured by Oji Paper Co., Ltd.).

Comparative Example 4
Evaluation was performed using a commercially available cast-coated paper (mirror-coated platinum, manufactured by Oji Paper Co., Ltd.) having a basis weight of 129.7 g / m ² .

Comparative Example 5
Evaluation was performed using commercially available art paper (NPi special art, manufactured by Nippon Paper Industries Co., Ltd.) having a basis weight of 157 g / m ² .

Quality evaluation method (basis weight measurement method)
It was measured by the method of JIS P 8124. The results are shown in Tables 1 and 2.

[Measurement method of glossiness of image area]
Based on the method of JIS Z 8741, a gloss measuring device (GM-26D type, manufactured by Murakami Color Research Co., Ltd.) was used, and the glossiness was measured on the image portion after fixing under the conditions of an incident angle and a light receiving angle of 60 degrees.

Evaluation of uniformity in gloss of image area Using the DocuCentreColor 500 (manufactured by Fuji Xerox Co., Ltd.), high-definition color digital standard image data (ISO / JIS-SCID JIS X) A color chart (S7) image sample of 9201-1995 compliant, published by the Japanese Standards Association) was created and the image portion Δ gloss was confirmed. Here, Δ gloss is a value obtained by the following equation. The results are shown in Tables 1 and 2.
Δ gloss (%) = maximum gloss (%)-minimum gloss (%)

  The DocuCentreColor 500 machine includes a latent image carrier, charging means for charging the surface of the latent image carrier, latent image forming means for forming a latent image on the surface of the latent image carrier, toner and carrier A developer containing the developer, developing the latent image with the developer layer formed on the surface of the developer carrier, and forming a toner image on the surface of the latent image carrier; and the toner An image forming apparatus includes a transfer unit that transfers an image to a transfer target, and a fixing unit that heat-presses a toner image on the transfer target.

  The electrophotographic transfer paper and the image forming method according to the present invention are an electrophotographic transfer paper and an image forming method in which the toner image portion has a uniform high glossiness, and are extremely useful in practice.

1 is a schematic configuration diagram illustrating an example of an image output apparatus used in an image forming method of the present invention. 1 is a schematic configuration diagram illustrating an example of a heat fixing device used in an image forming method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermal fixing roller 2 Pressure roller 3 Heat source 4 Fixing member surface layer 5 Elastic layer 6 Toner image 7 Transfer object (recording material)
DESCRIPTION OF SYMBOLS 11 Photoconductor 12 Roller-type charger 13 Exposure apparatus 14 Four-color developing device (14a, 14b, 14c, 14d)
15 Intermediate transfer member 16 Cleaner 17 Light neutralizer 18 Spindle roller (18a, 18b, 18c)
19 Transfer roller 20 Transfer object

Claims (2)

  In a transfer paper having a thermoplastic resin layer as a toner image receiving layer on one side or both sides of a coated paper having a coating layer mainly composed of an adhesive and a pigment, the toner image receiving layer has a boiling point of 135 ° C. or more and 350 ° C. An electrophotographic transfer paper characterized by containing a plant extract component having a melting point of 120 ° C. or lower.   A step of forming a latent image on the latent image carrier, a step of developing the latent image using an electrophotographic developer, a step of transferring the developed toner image to a transfer member, and a toner on the transfer member 2. An image forming method comprising a fixing step of heat-pressing an image, wherein the transferred material is the electrophotographic transfer paper according to claim 1.

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