JP2000010329A - Electrophotographic transfer paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electrophotographic transfer paper capable of obtaining a clear image by sufficiently reducing a recess/projection of a toner image at photographic printing time. SOLUTION: In electrophotographic transfer paper having a transfer layer at least on one surface of a support, the transfer layer is formed by meltingly extruding a resin composition containing 95 to 55 pts.wt. of polyethylene terephthalate and 5 to 45 pts.wt. of an aromatic polyester resin other than the polyethylene terephthalate on the support.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer paper for electrophotography in which a color toner image at the time of printing has a small unevenness and a clear image can be obtained.

[0002]

2. Description of the Related Art In electrophotography, an image is formed by heating and pressurizing a toner electrostatically adhered onto a transfer paper by a hot roll or the like to fix the toner. At this time, a slight but convex portion is formed on the transfer paper by the molten toner. In the case of a color image, especially in the black part,
The three color toners of yellow, magenta, and cyan are stacked, and the swelling of the toner is conspicuous, which causes a reduction in sharpness and surface gloss of an image.

To mitigate the effect of toner irregularities during printing, for example, Japanese Patent Application Laid-Open No. Sho 59-184361 discloses a method in which a lacquer or the like is sprayed and applied to an image surface to form a glossy film on the surface. Japanese Unexamined Patent Application Publication No. 5-88400 discloses a technique in which a transparent resin layer having an apparent melt viscosity lower than that of a toner binder resin at a toner fixing temperature is provided at an upper portion, and the toner is formed into a transparent resin. Techniques for submerging the layers are disclosed respectively. However, in the former method, since the lacquer containing a solvent is sprayed, the sharpness of an image may be reduced or color unevenness may occur due to the influence of the solvent. In the latter method, a surface layer having a low melting temperature is peeled off. And the image may be destroyed. Various attempts have been made to solve these problems.However, there has been no transfer paper for electrophotography which has a small unevenness of a toner image at the time of printing and provides a clear image. It is the current situation.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned conventional problems, and reduces the unevenness of a toner image at the time of printing sufficiently to obtain a clear image. The purpose is to provide.

[0005]

Means for Solving the Problems As a result of intensive studies on the electrophotographic transfer paper, the present inventors have found that an electrophotographic transfer paper having a transfer layer containing a specific aromatic polyester resin on a support. However, the present inventors have found that the unevenness of the color toner image at the time of printing, that is, the rise of the toner can be improved, and the present invention has been accomplished. That is, the present invention provides <1> an electrophotographic transfer paper having a transfer layer on at least one surface of a support, wherein the transfer layer contains 95 to 55 parts by weight of polyethylene terephthalate, An electrophotographic transfer paper formed by melt-extruding a resin composition containing 5-45 parts by weight of an aromatic polyester resin other than terephthalate onto the support. <2> The electrophotographic transfer paper according to <1>, wherein the aromatic polyester resin has a terephthalic acid unit, an ethylene glycol unit, a triethylene glycol unit, and an ethylene oxide adduct of bisphenol A. <3> The electrophotographic transfer paper according to <1>, wherein the aromatic polyester resin has a terephthalic acid unit, a tetramethylene glycol unit, and a polytetramethylene glycol unit. <4> The electrophotographic transfer paper according to any one of <1> to <3>, wherein the transfer-receiving layer further contains an inorganic pigment. In the present invention, by adding a specific aromatic polyester resin as a soft component to the polyethylene terephthalate constituting the transfer-receiving layer, the film quality of the transfer-receiving layer is softened, the toner is easily sunk, and the surface Smoothing can be achieved.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The electrophotographic transfer paper of the present invention has a transfer layer of a specific configuration on a support, but if necessary,
Other layers may be formed.

[Transferred Layer] The transferred layer contains a resin composition containing polyethylene terephthalate and other aromatic polyester resin, and preferably further contains an inorganic pigment, if necessary. , And other components.

(Polyethylene terephthalate) Polyethylene terephthalate (hereinafter sometimes referred to as “PET”) is a main component constituting the layer to be transferred.
The mixing ratio of the PET component to the aromatic polyester resin other than ET is 95 to 55 parts by weight, preferably 90 to 60 parts by weight, and more preferably 85 to 60 parts by weight. If the addition amount of the PET component is more than 95 parts by weight, the effect of reducing the unevenness of the toner image may be insufficient. On the other hand, when the addition amount of the PET component is less than 55 parts by weight, the stability of the laminated film is deteriorated, and the suitability for lamination may be poor due to a phenomenon such as neck-in. The P
ET preferably has an IV value (intrinsic viscosity) of 0.5 to 0.8 with respect to the melt laminate. PET used in the present invention can be synthesized by a conventionally known method.

(Aromatic Polyester Resin) As described above, in the present invention, from the viewpoint of softening the film quality of the layer to be transferred, facilitating the penetration of the toner at the time of printing, and absorbing the raised portion of the toner, PET that constitutes
On the other hand, an aromatic polyester resin other than PET is added as a soft component. The aromatic polyester resin is
Since it is excellent in heat resistance, unlike a case where an aliphatic polyester resin having inferior heat resistance is mixed with PET and melt-extruded, deterioration of lamination suitability is less likely. It is also conceivable to add a small amount of a polyolefin-based resin as a soft component. However, the phase-separated state from PET, that is, a "sea-island structure" is obtained, and the effect of uniformly softening the very surface of the transfer-receiving layer is small. It is not possible to solve the excitement.

The mixing ratio of the aromatic polyester resin to PET is as follows.
5 parts by weight, preferably 10 to 40 parts by weight,
More preferably, it is 15 to 40 parts by weight. If the amount of the aromatic polyester resin is less than 5 parts by weight, the effect of reducing the unevenness of the toner image may be insufficient. On the other hand, when the amount of the aromatic polyester resin added is 4
If the amount is more than 5 parts by weight, the stability of the laminate film may be deteriorated or the fixability of the toner image may be poor.

It is preferable that the aromatic polyester resin has a terephthalic acid unit, an ethylene glycol unit, a triethylene glycol unit, and an ethylene oxide adduct unit of bisphenol A. For more information,
The aromatic polyester resin has a repeating unit of an aromatic dibasic acid component containing a terephthalic acid unit, and a repeating dihydric alcohol component containing an ethylene glycol unit, a triethylene glycol unit, and an ethylene oxide adduct unit of bisphenol A. It is preferred to have a unit.

The aromatic polyester resin preferably has a terephthalic acid unit, a tetramethylene glycol unit, and a polytetramethylene glycol unit. Specifically, the aromatic polyester resin,
It is preferable to have a repeating unit of an aromatic dibasic acid component containing a terephthalic acid unit and a repeating unit of a dihydric alcohol component containing a tetramethylene glycol unit and a polytetramethylene glycol unit.

As the repeating unit of the aromatic dibasic acid component, a terephthalic acid unit is particularly preferably used. In addition, an isophthalic acid unit, a 2,6-naphthalenedicarboxylic acid unit, a sulfobenzenedicarboxylic acid unit and the like can be used. It is preferably used. These may be used alone or in combination of two or more.

The total of the repeating units of the aromatic dibasic acid component accounts for at least 80 mol%, preferably at least 90 mol%, and more preferably at least 100 mol% of the total repeating units of all dibasic acid components. Most preferred. As the dibasic acid component other than the above, aromatic dicarboxylic acids such as phthalic acid and 2,7-naphthalenedicarboxylic acid; adipic acid, malonic acid, succinic acid, azelaic acid, sebacic acid and the like, as long as the properties are not impaired. Aliphatic dicarboxylic acids; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid can be used. Also, a polybasic acid component such as trimellitic acid may be used.

As the repeating unit of the dihydric alcohol component, an ethylene glycol unit, a triethylene glycol unit, a tetramethylene glycol unit, a polytetramethylene glycol unit, and an ethylene oxide adduct of bisphenol A are particularly preferably used.
In addition, diethylene glycol units, tetraethylene glycol units, and the like are preferably used. These may be used alone or in combination of two or more. When a bisphenol A unit or a derivative unit thereof is added, the crystallinity of the aromatic polyester resin can be suppressed, and the embedding of the toner in the transfer layer can be improved.

The total of the repeating units of the dihydric alcohol component accounts for at least 70 mol%, preferably at least 80 mol%, and preferably at least 90 mol% of the total of the repeating units of all polyhydric alcohol components. More preferably, it is most preferably 100 mol%. As polyhydric alcohol components other than those described above, 1,4-butanediol, 1,6-hexanediol, 1,3-propanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, 1,2-propylene glycol, 1,3-butylene glycol,
1,2-butylene glycol, diethylene glycol,
Polyethylene glycol or the like can be used.

In particular, the aromatic polyester resin preferably contains 1 to 55 mol% of an ethylene oxide adduct of bisphenol A as a dihydric alcohol component.

Since the aromatic polyester resin is appropriately softened at the toner fixing temperature, the toner is embedded in the transfer-receiving layer, and the inclination angle between the surface of the transfer-receiving layer and the toner at the fixing temperature generally becomes small. Thus, a fixed image having almost no unevenness can be obtained. Hereinafter, the aromatic polyester resin preferably used in the present invention will be described in detail. The aromatic polyester resin has the following (a):

[0019]

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A repeating unit of an aromatic dibasic acid component containing a terephthalic acid unit represented by the following formula (b):

[0021]

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An ethylene glycol unit represented by the following (c):

[0023]

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A triethylene glycol unit represented by the following formula (d):

[0025]

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(However, n represents 1 to 5) It is preferable to have a repeating unit of a dihydric alcohol component including an ethylene oxide adduct unit of bisphenol A represented by the following formula: As such an aromatic polyester resin, for example, “STAFIX” represented by the following formula:
F-LC "(manufactured by Fuji Photo Film Co., Ltd.).

[0027]

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Further, the aromatic polyester resin has the following (e):

[0029]

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A repeating unit of an aromatic dibasic acid component containing a terephthalic acid unit represented by the following formula (f):

[0031]

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A tetramethylene glycol unit represented by the following (g):

[0033]

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It is preferable to have a repeating unit of a dihydric alcohol component containing a polytetramethylene glycol unit represented by the following formula: As such an aromatic polyester resin, for example, “Hytrel” (Toray-Du)
Plon), "Grelax" (manufactured by Dainippon Ink and Chemicals), "Perprene" (manufactured by Toyobo) and the like.

The above-mentioned aromatic polyester resin may be made of ordinary polyethylene terephthalate or polyethylene-terephthalate.
As in the synthesis of 2,6-naphthalate, an oligomer can be obtained by subjecting a dibasic acid and a dihydric alcohol to an esterification reaction or a transesterification reaction, and then subjected to a polycondensation reaction under vacuum to synthesize the compound. In addition, Tokubo Sho 5
It can also be obtained by a polyester depolymerization method as described in JP-A-3-37920. As the dibasic acid, a transesterification reaction is carried out using at least one of alkyl esters of dicarboxylic acids such as dimethyl terephthalate, dimethyl isophthalate and dimethyl-2,6-naphthalene carboxylate, followed by a polycondensation reaction. Alternatively, direct esterification using a dicarboxylic acid followed by a polycondensation reaction may be performed.

For example, a dibasic acid and a dihydric alcohol are reacted at 180 to 280 ° C. under atmospheric pressure for 120 to 240 minutes,
The distillation of water or alcohol is terminated to complete the transesterification reaction. Next, the pressure in the reaction system was reduced to 1 mmHg.
At the same time as the high vacuum described below, the temperature is raised to 240 to 290 ° C., and the mixture is heated at this temperature for 60 to 180 minutes to obtain an aromatic polyester resin.

The number average molecular weight of the aromatic polyester resin is preferably in the range of 1500 to 5000. The weight average molecular weight of the aromatic polyester resin is 2500
The range of ~ 15000 is preferred. The (weight average molecular weight / number average molecular weight) of the aromatic polyester resin is 1.2
It is preferably in the range of 3.0 to 3.0.

(Inorganic Pigment) In the present invention, it is preferable to add an inorganic pigment to the transfer-receiving layer for the purpose of improving whiteness and sharpening an image. As the inorganic pigment, for example, titanium oxide, barium sulfate, zinc oxide,
Powders such as talc, calcium carbonate, aluminum oxide, and silicon oxide, solid solutions thereof, and the like can be used, and blue or violet pigments such as ultramarine blue can also be used. The particle diameter of the inorganic pigment is 0.04 to 1 μm
It is about. If the particle diameter is smaller than 0.04 μm, it is difficult to uniformly disperse the inorganic pigment in the resin, which is not preferable. On the other hand, if the particle diameter is larger than 1 μm, the surface of the coating film of the composition becomes too rough, and the image quality deteriorates, which is not preferable. The amount of the inorganic pigment to be added is preferably 1 to 30% by weight, more preferably 3 to 10% by weight, based on the resin composition. If the amount added is less than 1% by weight,
In some cases, the effect of improving the whiteness is poor, while when the addition amount is more than 30% by weight, the stability of the laminate film may be poor. Among these inorganic pigments, titanium oxide and barium sulfate are preferred from the viewpoint of whiteness, and the preferred average particle size is 0.1 to 0.8 μm.
Specific commercial names of the inorganic pigment used include KA-10 and KA-20 manufactured by Titanium Industry.

(Other Components) Other components can be added to the transferred layer for the purpose of controlling the properties of the layer, as long as the effects of the present invention are not impaired. The resin composition constituting the transfer-receiving layer may contain, in addition to the polyethylene terephthalate and the aromatic polyester resin, another polymer in a range of 20% by weight or less of all components of the transfer-receiving layer. As the polymer used in combination, those having a glass transition temperature of 60 ° C. or higher (preferably 60 to 120 ° C.) are generally used. For example, other than the above polyester resin, polyether resin, acrylic resin, epoxy resin,
Urethane resins, amino resins, phenolic resins and the like can be mentioned.

In the transfer-receiving layer, other components include
A filler, a matting agent, a fluorescent whitening agent, a release agent, an anti-fading agent and the like can be contained. The filler can be added for the purpose of adjusting the coefficient of friction. Examples of the filler include silica, alumina, calcium carbonate, and the like. The method of adding these pigments and fillers to the resin composition forming the layer to be transferred is not particularly limited. For example, a method of directly adding the resin into the extruder when melt extruding the resin, A known suitable method such as a method of preparing a pellet and adding the pellet can be applied.

Since the addition of the matting agent can improve the slipperiness, a good effect is obtained also on abrasion resistance and scratch resistance. Materials used for the matting agent include fluorine resin, low molecular weight polyolefin organic polymer (for example, polyethylene matting agent, paraffinic or microcrystalline wax emulsion), and material used for substantially spherical matting agent. As beaded plastic powder (material example, cross-linked PMM
A, polycarbonate, polyethylene terephthalate,
Polyethylene or polystyrene), and inorganic fine particles (eg, SiO ₂ , Al ₂ O ₃ , talc or kaolin). The content of the matting agent is preferably from 0.1 to 10% by weight based on the resin composition.

Examples of the above-mentioned fluorescent whitening agents include K.K. Vee
“The Chemistry of Synthetic Soybeans” edited by Nkataaraman
fsynthetic dyes) ", Volume V, Chapter 8,
Examples include compounds described in JP-A-61-143752. Specifically, stilbene compounds,
Coumarin-based compounds, biphenyl-based compounds, benzoxazolyl-based compounds, naphthalimide-based compounds, pyrazoline-based compounds, carbostyril-based compounds, and 2,5-dibenzoxazole-thiophene-based compounds are exemplified. The fluorescent whitening agent can be used in combination with the anti-fading agent.

Examples of the releasing agent include solid or wax-like substances such as polyethylene wax, amide wax, fine powder of silicone resin, and fine powder of fluorine resin: surfactants such as fluorine-based and phosphate-based surfactants: Any conventionally known release agents such as paraffin-based, silicone-based, and fluorine-based oils can be used.

As the anti-fading agent, for example, an antioxidant, an ultraviolet absorber, or a certain metal complex can be used. Examples of the antioxidant include a coumarone-based compound, a coumaran-based compound, a phenol-based compound (for example, hindered phenols), a hydroquinone derivative, a hindered amine derivative, and a spiroindane-based compound. Further, the compounds described in JP-A-61-159644 are also effective.

Examples of the ultraviolet absorber include benzotriazole compounds (described in US Pat. No. 3,533,794) and 4-thiazolidone compounds (US Pat.
Benzophenone compounds (described in JP-A-56-2784, etc.), and others described in JP-A-54-48535, JP-A-62-136641, and JP-A-61-88256. There is a compound of Further, an ultraviolet absorbing polymer described in JP-A-62-260152 is also effective.

As the metal complex, US Pat.
No. 55, No. 4245018 (columns 3 to 36), No. 4
No. 254195 (columns 3 to 8), JP-A-62-1747.
Compounds described in JP-A-41-61, JP-A-61-88256 (pages 27 to 29), JP-A-1-75568, JP-A-63-199248 and the like.

Examples of useful anti-fading agents are specifically described in JP-A-62-215272 (pages 125 to 137).
It is described in. As the anti-fading agent to be contained in the transfer-receiving layer, an inorganic fine powder is preferable. Specifically, it is a fine powder of titanium oxide, zinc oxide, or the like.
It is about 00 nm. The content of these fine powders is preferably from 0.1 to 50% by weight, more preferably from 0.1 to 20% by weight, based on the total amount of the components to be transferred. The antioxidant used as the anti-fading agent, the ultraviolet absorber, the metal complex, each may be used alone,
Two or more kinds may be used in combination. These different fading preventions may be used in combination.

Various surfactants can be used in the transfer-receiving layer as a coating aid or for the purpose of improving releasability, improving slipperiness, and preventing static charge. As the surfactant, a nonionic surfactant, an anionic surfactant,
Either an amphoteric surfactant or a cationic surfactant can be used. Specific examples thereof are described in JP-A-62-17.
Nos. 3463 and 62-183457.

(Melt Extrusion Method, etc.) The transfer layer in the electrophotographic transfer paper of the present invention is formed by a melt extrusion method. In the melt extrusion method, a laminating method in which a molten resin film extruded from a heated extruder through a wide slit die (so-called T-die) is brought into contact with a support and continuously pressed by a roller, A general method of extruding a resin on a cooling roll, winding the film, and forming a film may be used. According to the melt extrusion method, a uniform film made of the resin composition can be easily formed on a support. The extruder used for the formation of the transferred layer by the melt extrusion method may be a single-screw type or a twin-screw type, but has an ability to uniformly mix the polyethylene terephthalate and the aromatic polyester resin. It is important that there is.

The transfer layer can be formed on one surface or both surfaces of the support. The thickness of the transferred layer is preferably in the range of 20 to 45 μm, and 23 to 3 μm.
A range of 5 μm is more preferable. When the layer thickness is less than 20 μm, the adhesion to the support may be deteriorated, and the embedding of the toner may be deteriorated. On the other hand, if the layer thickness is more than 45 μm, the stiffness becomes too high, and for example, jamming may occur when the film is passed through a printer.

The transfer layer is 1 × 10 ⁹ to 1 × 10 ^13.
It is preferable to have a surface electric resistance in the range of Ω (under conditions of 25 ° C. and 65% RH). If it is less than 1 × 10 ⁹ Ω, the amount of toner when the toner is transferred to the transfer layer of the electrophotographic transfer paper is not sufficient, and the density of the obtained toner image may be low. On the other hand, when the resistance exceeds 1 × 10 ¹³ Ω, an excessive charge is generated at the time of transfer, the toner is not sufficiently transferred, the density of an image is reduced, and static electricity is generated during handling of the electrophotographic transfer paper. Dust easily adheres, and misfeeds, double feeds, discharge marks, toner transfer defects, and the like easily occur during copying.

The transferred layer may contain a surfactant for the purpose of adjusting the transferred layer to the surface electric resistance or the like. Examples of the surfactant include an alkylbenzene imidazole sulfonate, a naphthalene sulfonate, a carboxylate sulfonate, a phosphate, a heterocyclic amine, an ammonium salt, a phosphonium salt and a betaine amphoteric salt, or ZnO, SnO ₂ , Al ₂
Metal oxides such as O ₃ , In ₂ O ₃ , MgO, BaO, and MoO ₃ are mentioned.

[Support] In the present invention, when the layer to be transferred is formed on the surface of the support, the substrate of the support can withstand the transfer temperature, and has smoothness, whiteness, slipperiness, and friction. Any material can be used as long as it satisfies requirements in terms of antistatic property, dent after transfer, and the like. For example, high quality paper, art paper, coated paper, cast coated paper,
Wallpaper, backing paper, synthetic resin or emulsion impregnated paper,
Paper support such as synthetic rubber latex-impregnated paper, synthetic resin-coated paper, paperboard, cellulose fiber paper, polyolefin-coated paper (especially paper coated on both sides with polyethylene), and a layer composed of any of the above-mentioned substrates Can also be used.

The base paper used for the support in the present invention is selected from materials generally used for photographic printing paper. That is, natural pulp or synthetic pulp selected from softwood or hardwood as the main raw material, if necessary, clay, talc, calcium carbonate, fillers such as urea resin fine particles, rosin, alkyl ketene dimer, higher fatty acids, epoxidized fatty acid amide, Paraffin wax, sizing agents such as alkenyl succinic acid, starch, polyamide-polyamine epichlorohydrin, paper strength agents such as polyacrylamide, sulfate band,
Those to which a fixing agent such as a cationic polymer is added are used.

The thickness of the base paper is preferably from 50 to 200 μm, more preferably from 80 to 170 μm. When the thickness is out of this range, jamming may occur in an electrophotographic copying machine or a printer, or difficulty may occur in a hand feeling. The base paper is preferably subjected to a surface treatment by applying heat and pressure using a device such as a machine calender or a super calender for the purpose of imparting smoothness and flatness. When forming the transfer-receiving layer on the base paper, a pre-treatment such as a glow discharge treatment, a corona discharge treatment, a flame treatment, and an anchor coat is preferably performed on the base paper surface in order to improve the adhesion between the transfer-receiving layer and the base paper. Is preferred.

[Other Layers] When the support is used for the electrophotographic transfer paper of the present invention, an intermediate layer may be provided between the support and the transfer layer. The intermediate layer can serve as a cushion layer, a porous layer, a layer for adjusting the rigidity of the paper to be transferred, and the like, and in some cases, a function as an adhesive layer. In addition, a back coat layer may be provided on the surface of the support opposite to the surface on which the transfer layer is formed in order to enhance the running property of the transfer paper.

In the present invention, when a desired surface electric resistance cannot be obtained by the above-mentioned surfactant, a conductive undercoat layer may be provided between the support and the transfer-receiving layer. The conductive undercoat layer is a layer in which conductive metal oxide particles are dispersed in a binder. As the material of the conductive metal oxide particles, ZnO, TiO, SnO ₂ , Al ₂ O ₃ , In ₂ O
₃ , SiO ₂ , MgO, BaO and MoO ₃ . These may be used alone or a composite oxide thereof may be used. The metal oxide preferably further contains a different element, for example, Al, In or the like for ZnO, Nb or Ta for TiO, or SnO or the like.
_{As for 2} , those containing (doping) Sb, Nb, a halogen element and the like are preferable. Among these, Sb
SnO ₂ is particularly preferred doped with. The particle diameter of the conductive metal oxide particles is preferably 0.2 μm or less.

Examples of the binder material for the conductive undercoat layer include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyhydroxyethyl acrylate, polyvinyl pyrrolidone, water-soluble polyester, water-soluble polyurethane, water-soluble nylon, and water-soluble epoxy. Water-soluble polymers such as resins, gelatin, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose and derivatives thereof; water-dispersible resins such as water-dispersed acrylic resins and water-dispersed polyesters; acrylic resin emulsions, polyvinyl acetate emulsions, SBR (styrene) Emulsions such as butadiene rubber) emulsions; and organic solvent-soluble resins such as acrylic resins and polyester resins. Of these, water-soluble polymers, water-dispersible resins and emulsions are preferred. A surfactant may be further added to these polymers, and a crosslinking agent or the like may be added.

[0059]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples. Unless otherwise specified in the text, “parts” means “parts by weight”.

Example 1 A resin composition composed of 70 parts of polyethylene terephthalate and 30 parts of “STAFIX F-LC” (manufactured by Fuji Photo Film Co., Ltd.) was melted at 290 ° C. by a melt extruder. By nipping and laminating between a nip roll and a cooling roll onto a 160 μm thick base paper discharged from a die and subjected to flame treatment, as shown in FIG. Transfer paper 10 for electrophotography formed with
Was prepared.

The following evaluations were made when the above-mentioned paper to be transferred was prepared and for the prepared paper to be transferred. Table 1 shows the evaluation results. <Evaluation of Laminating Suitability> The stability of the molten resin film when extruded from a T-die at a generally known PET melt extrusion temperature of 290 ° C. was evaluated according to the following criteria. ○ ・ ・ ・ Stable △ ・ ・ ・ Disturbed film ears etc. × ・ ・ ・ Unable to laminate

<Evaluation of toner swelling> In the center of a postcard-size transfer sheet, a black laser is printed by a color laser printer 3310 manufactured by Fuji Xerox Co., Ltd.
When black was printed with an area of cm square, the difference (Δh) in thickness between the black printed portion and the non-printed portion was measured and evaluated according to the following criteria. ◎ ・ ・ ・ Δh is less than 1 μm ○ ・ ・ ・ 1 μm or more to less than 2 μm △ ・ ・ ・ 2 μm or more to less than 5 μm × ・ ・ ・ 5 μm or more

<Evaluation of Roughness of Image> Similarly, a spot-like color loss, darkness and sharpness of a black print were visually evaluated according to the following criteria.・ ・ ・: No color loss, no difference in lightness and sharpness △: slight inferior color, lightness, and sharpness ×: two or more inferior color, lightness, and sharpness

(Example 2) The resin composition of Example 1 was added to 95 parts of a resin composition composed of 60 parts of PET and 35 parts of “STAFIX F-LC” by using titanium oxide particles (KA-
20, manufactured by Titanium Industry Co., Ltd.), and the base paper was replaced with a base paper having a thickness of 130 μm, as shown in FIG.
A transfer layer 22 is formed on the upper surface of the base paper 21 and PET is formed on the lower surface.
Backcoat layer 23 containing 100 parts of resin composition
A transfer paper for electrophotography 20 was prepared in the same manner as in Example 1 except that was formed, and the same evaluation as in Example 1 was performed.
Table 1 shows the evaluation results.

Example 3 The resin composition of Example 1 was prepared by mixing 85 parts of PET and “Hytrel 4057” (Toray-D
An electrophotographic transfer paper was prepared in the same manner as in Example 1, except that the base paper was replaced with a base paper having a thickness of 130 μm, instead of the resin composition consisting of 15 parts (upon). An evaluation was performed. Table 1 shows the evaluation results.

Example 4 The resin composition of Example 1 was replaced with a resin composition consisting of 90 parts of PET and 10 parts of “Greak E120” (manufactured by Dainippon Ink and Chemicals, Inc.), and the base paper was 125 μm thick. As in FIG. 2, instead of the base paper, a transfer layer 22 was formed on the upper surface of the base paper 21 and a back coat layer 23 containing a resin composition composed of 100 parts of PET was formed on the lower surface. In this way, an electrophotographic transfer paper 20 was prepared, and the same evaluation as in Example 1 was performed. Table 1 shows the evaluation results.

Comparative Example 1 A transfer paper for electrophotography was prepared in the same manner as in Example 1 except that the resin composition in Example 1 was replaced with a resin composition comprising 100 parts of PET. The same evaluation was performed. Table 1 shows the evaluation results.

(Comparative Example 2) The resin composition of Example 1 was replaced with a resin composition consisting of 40 parts of PET and 60 parts of “STAFIX F-LC”, and the base paper was replaced with a base paper having a thickness of 130 μm. As shown in the drawing, a transfer layer for electrophotography was formed in the same manner as in Example 1 except that a transfer layer 22 was formed on the upper surface of the base paper 21 and a back coat layer 23 containing a resin composition composed of 100 parts of PET was formed on the lower surface. Make paper 20,
The same evaluation as in Example 1 was performed. Table 1 shows the evaluation results.

Comparative Example 3 The resin composition of Example 1 was replaced with a resin composition comprising 60 parts of PET and 40 parts of an aliphatic polyester (Polysizer W360, manufactured by Dainippon Ink and Chemicals, Inc.), and the base paper was 130 μm thick. As shown in FIG. 2, instead of the base paper of
However, it was not possible to form a uniform layer to be transferred due to poor thermal suitability of the resin.

(Comparative Example 4) The resin composition in Example 1 was replaced with a resin composition consisting of 85 parts of PET and 15 parts of polypropylene, and the base paper was replaced with a base paper having a thickness of 125 μm.
As shown in FIG. 2, electrophotography was performed in the same manner as in Example 1 except that a transfer layer 22 was formed on the upper surface of the base paper 21 and a back coat layer 23 containing a resin composition composed of 100 parts of PET was formed on the lower surface. A transfer paper 20 was prepared, and the same evaluation as in Example 1 was performed. Table 1 shows the evaluation results.

[0071]

[Table 1]

From the results shown in Table 1, it can be seen that Examples 1-4, which are the electrophotographic transfer papers of the present invention, are excellent in lamination suitability, toner swelling, and image roughness. On the other hand, in Comparative Example 1 having a layer to be transferred that does not contain an aromatic polyester resin other than PET, the toner swells. In contrast, P
In Comparative Example 2 having a transfer-receiving layer containing a large amount of an aromatic polyester resin other than ET, graininess of an image occurs. In Comparative Example 3 having a layer to be transferred containing an aliphatic polyester resin, lamination could not be performed due to poor heat suitability. In Comparative Example 4 having a transfer layer containing polypropylene, toner swelling occurred and image formation was poor.

[0073]

According to the present invention, it is possible to provide a transfer paper for electrophotography in which unevenness of a toner image at the time of printing is sufficiently small and a clear image can be obtained.

[0074]

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating an example of a basic configuration of an electrophotographic transfer sheet of the present invention.

FIG. 2 is a schematic cross-sectional view showing another example of the basic configuration of the electrophotographic transfer paper of the present invention.

[0075]

[Explanation of symbols]

 10, 20 Transfer paper for electrophotography 11, 21 Base paper 12a, 12b, 22 Transfer layer 23 Back coat layer

Claims (4)

[Claims] 1. An electrophotographic transfer paper having a transfer layer on at least one surface of a support, wherein the transfer layer contains 95 to 55 parts by weight of polyethylene terephthalate and an aromatic substance other than the polyethylene terephthalate. An electrophotographic transfer paper formed by melt-extruding a resin composition containing 5 to 45 parts by weight of an aromatic polyester resin onto the support. 2. The transfer paper for electrophotography according to claim 1, wherein the aromatic polyester resin has a terephthalic acid unit, an ethylene glycol unit, a triethylene glycol unit, and an ethylene oxide adduct of bisphenol A. 3. The electrophotographic transfer paper according to claim 1, wherein the aromatic polyester resin has a terephthalic acid unit, a tetramethylene glycol unit, and a polytetramethylene glycol unit. 4. The transfer paper for electrophotography according to claim 1, wherein the transfer-receiving layer further contains an inorganic pigment.