JP2003076053A - Electrophotographic image receiving paper and method for forming image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic image receiving paper which can be easily manufactured compared to a conventional electrophotographic image receiving paper and which yields excellent toner images and gloss. SOLUTION: The paper has a base paper and a toner image receiving layer applied on at least one surface of the base paper. The surface of the base paper on the toner image receiving layer side shows >=210 seconds smoothness degree by the Oken method and >=100 seconds Stoeckigt sizing degree. The toner image receiving layer contains <40 mass% pigment based on the mass of the thermoplastic resin which constitutes the layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image receiving paper and an image forming method, and more particularly to a copying machine, a printer,
A high-quality electrophotographic image-receiving paper and a high-quality electrophotographic image-receiving paper that can be used in a device utilizing an electrophotographic process such as a facsimile, for example, a color copying machine and can impart excellent image quality and glossiness of a photographic image. The present invention relates to an image forming method.

[0002]

2. Description of the Related Art Offset printing is the mainstream in general commercial printing and high-grade printing, and art paper and coated paper such as coated paper are used. This is because the surface of the coated paper is very smooth, the transferability of the ink is good, the image reproducibility is high, and the gloss of the image is high and the color reproducibility is good. is there.

However, the coating layer of coated paper contains a large amount of pigment and is highly hygroscopic. Therefore, when the coated paper itself is used as an electrophotographic image-receiving paper, when the image is fixed by heat, the water vapor in the coated paper expands and the blister (coating layer) is applied between the base paper and the coating layer. There is a problem that blurring of the work layer occurs, which causes the image to be rough and it is not possible to obtain a fine image quality like a photograph. Further, these conventional coated papers have a problem that the gloss is inferior when image information such as a face or a landscape is output as a photograph. Therefore, until now, the use of coated paper as an electrophotographic image receiving paper is
The current situation is that most of the time, it is not usually done.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems in the prior art and to solve the following problems. That is, the present invention is an electrophotographic image receiving paper which can be easily manufactured and is excellent in glossiness as compared with the conventional electrophotographic image receiving paper, and an image forming using the electrophotographic image receiving paper. The purpose is to provide a method.

[0005]

Means for Solving the Problems As a result of intensive studies in view of the above problems, the present inventors have used a base paper having a specific Oken type smoothness and a specific Steckigt / size as a base paper. In addition, by forming a toner image receiving layer containing substantially no pigment on the base paper, the toner image receiving layer for electrophotography can be manufactured more easily, and the toner image and gloss obtained can be improved. The present inventors have found that an excellent electrophotographic image-receiving paper can be provided, and have reached the present invention.

That is, the means for solving the above-mentioned problems are as follows:
It is as follows. <1> An electrophotographic image-receiving paper having a base paper and a toner image-receiving layer provided on at least one surface of the base paper, wherein the surface of the base paper on the toner image-receiving layer side has Oken type smoothness. 21
0 second or more and a Steckigt sizing degree of 100 seconds or more, and the toner image-receiving layer is 40% by mass based on the mass of the thermoplastic resin constituting the toner image-receiving layer.
The electrophotographic image-receiving paper is characterized by containing a pigment in an amount of less than 1. <2> The electrophotographic image-receiving paper according to <1>, wherein the Oken type smoothness is 250 seconds or more. <3> The electrophotographic image-receiving paper according to <1> or <2>, wherein the Steckigt sizing degree is 150 seconds or more. <4> The <1>, wherein the pigment is less than 30% by mass.
To <3>, the electrophotographic image receiving paper. <5> The electrophotographic image receiving sheet according to any one of <1> to <4>, wherein the toner image forming surface of the electrophotographic image receiving sheet has a glossiness of 20 or more. <6> The electrophotographic image receiving paper according to any one of <1> to <5>, wherein the toner image forming surface of the electrophotographic image receiving paper has an average surface roughness of 2 μm or less. <7> The toner image forming surface of the electrophotographic image receiving paper is L ^*
In the a ^* b ^* space, 80 <L ^* , −2 <a ^* <2,
-10 <b ^* <<6> satisfying the conditions of <2>
The image receiving paper for electrophotography according to any one of 1. <8> The toner image forming surface of the electrophotographic image receiving paper has a reflectance of 80% or more with respect to light in the wavelength range of 450 to 700 nm, and a difference between the maximum reflectance and the minimum reflectance with respect to light in the wavelength range. 5% or less <1> to <7>
The image receiving paper for electrophotography according to any one of 1. <9> An image forming method using the electrophotographic image receiving sheet according to any one of <1> to <8>, wherein a toner image is formed on the electrophotographic image receiving sheet, and then the electrophotographic image receiving sheet is formed. The image forming method is characterized in that the image forming surface of the paper is heated and pressed by a fixing belt.

By the way, Japanese Unexamined Patent Publication (Kokai) No. 5-241366 discloses a coated paper which can be used as an image receiving paper for electrophotography, and a base paper having an Oken smoothness of 35 to 200 seconds is used as the base paper. I suggest what to do. However,
On the base paper used here, a large amount of pigment, for example 7
A recording layer (toner image-receiving layer) containing 6 to 95% by mass ([0014]) of pigment is formed. Therefore, there is a problem that streaks and the like caused by using a coating layer using a pigment are likely to occur particularly when the Oken type smoothness exceeds 200 seconds. Therefore, the above publication requires that the Oken smoothness is 200 seconds or less, and does not refer to the base paper having 210 seconds or more.

Similarly, Japanese Unexamined Patent Publication No. 2000-235276 discloses a thick electrophotographic recording paper, and the recording paper used therein has an Oken type smoothness of 70 to 200 seconds. It is used. However, even in this publication, when the Oken type smoothness exceeds 200 seconds, it is described that feeding failure at the time of sheet feeding and multi-sheet feeding are likely to occur, and no mention is made of a base sheet of 210 seconds or more. Not not.

On the other hand, Japanese Patent Laid-Open No. 5-173352 discloses
The present invention relates to an electrophotographic image-receiving paper in which the sizing degree (Steckigt sizing degree) of the base paper is set within a predetermined range by using a specific sizing agent. However, in this publication, the Steckigt sizing degree on the surface of the base paper is as low as 10 to 20 seconds, and no reference is made to a very large Steckigt sizing degree of 100 seconds or more.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The electrophotographic image-receiving paper of the present invention has a base paper and a toner image-receiving layer provided on at least one surface of the base paper,
Other layers appropriately selected as necessary, for example, a protective layer, an intermediate layer, an undercoat layer, a cushion layer, a charge control (prevention) layer, a reflective layer, a tint adjusting layer, a storage stability improving layer, an anti-adhesion layer, an anti-layer. It has a curl layer and a smoothing layer. Each of these layers may have a single-layer structure or a laminated structure.

<Base Paper> A base paper is used as the base paper for the electrophotographic image-receiving paper of the present invention. As pulp that can be used as a raw material for base paper, the surface smoothness, rigidity and dimensional stability (curl property) of the base paper are simultaneously well balanced,
Further, from the viewpoint of improving to a sufficient level, bleached hardwood kraft pulp (LBKP) is preferable, but bleached softwood kraft pulp (NBKP), hardwood sulfite pulp (LBSP) and the like can also be used. As the pulp fiber, it is suitable to use mainly hardwood pulp, which originally has a short fiber length. A beater, a refiner, etc. can be used for beating pulp. In the pulp slurry obtained after beating the pulp (hereinafter sometimes referred to as “pulp paper stock”), various additives such as a filler, a dry paper strengthening agent, and a size are added as necessary. Agents, wet paper strengthening agents, fixing agents, pH adjusting agents, and other agents are added.

As the filler, for example, calcium carbonate,
Examples thereof include clay, kaolin, clay, talc, titanium oxide, diatomaceous earth, barium sulfate, aluminum hydroxide, magnesium hydroxide and the like. As the dry paper strengthening agent, for example, cationized starch, cationized polyacrylamide,
Examples include anionized polyacrylamide, amphoteric polyacrylamide, carboxy-modified polyvinyl alcohol and the like. Examples of the sizing agent include fatty acid salt, rosin, rosin derivatives such as maleated rosin, paraffin wax, and higher fatty acids such as alkyl ketene dimer, alkenyl succinic anhydride (ASA), and epoxidized fatty acid amide. And the like.

Examples of the wet strength agent include polyamine polyamide epichlorohydrin, melamine resin, urea resin, epoxidized polyamide resin and the like. Examples of the fixing agent include polyvalent metal salts such as aluminum sulfate and aluminum chloride, and cationic polymers such as cationized starch. Examples of the pH adjusting agent include caustic soda and sodium carbonate. Examples of other agents include antifoaming agents, dyes, slime control agents, optical brighteners, and the like. In addition, a softening agent or the like can be added if necessary. The softening agent is described in, for example, New Paper Processing Handbook (edited by Shiyaku Time Co., Ltd.), pages 554 to 555 (issued in 1980).

The treatment liquid used for the surface size treatment includes
For example, water-soluble polymer, sizing agent, water resistant substance, pigment,
A pH adjusting agent, a dye, a fluorescent whitening agent, etc. may be contained. Examples of the water-soluble polymer include cationized starch,
Examples thereof include polyvinyl alcohol, carboxy-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, cellulose sulfate, gelatin, casein, sodium polyacrylate, sodium salt of styrene-maleic anhydride copolymer, sodium polystyrene sulfonate and the like.

As the water resistant substance, for example, styrene-
Butadiene copolymer, ethylene-vinyl acetate copolymer,
Examples thereof include latex and emulsions such as polyethylene and vinylidene chloride copolymer, and polyamide polyamine epichlorohydrin. Examples of the pigment include calcium carbonate, clay, kaolin, talc, barium sulfate, titanium oxide and the like. As an example of the raw paper material, in addition to the above-mentioned natural pulp paper, synthetic pulp paper, mixed paper of natural pulp and synthetic pulp, and various kinds of laminated paper can be used.

The thickness of the base paper, that is, the base paper is usually 30 to
It is suitable that the thickness is 500 μm, preferably 50 to 300 μm, and particularly preferably 100 to 200 μm.
In order to improve the rigidity and the dimensional stability (curl property) of the electrophotographic image receiving paper, the above-mentioned base paper has a ratio (Ea / Eb) of the Young's modulus in the longitudinal direction (Ea) to the Young's modulus in the transverse direction (Ea / Eb). )
Is preferably in the range of 1.5 to 2.0. Ea /
When the Eb value is less than 1.5 or exceeds 2.0,
Rigidity and curl of electrophotographic image receiving paper tend to deteriorate,
This is not preferable because it will hinder the running property during transportation.

In the present invention, the Oken type smoothness of the surface of the base paper on the toner image receiving layer side is 210 seconds or more, preferably 2
50 seconds or more. When the Oken type smoothness is less than 210 seconds, the image quality of the toner image becomes poor, which is not preferable.
The upper limit is not particularly limited, but in practice, about 600 seconds, preferably about 500 seconds will be appropriate. In the present invention, the Oken-type smoothness is much larger than the Oken-type smoothness that has been conventionally used.
The object of the present invention is achieved by adopting 0 seconds or more. Here, the Oken smoothness is JAPAN
TAPPI No. 5 Smoothness defined by the B method.

Once the present invention is disclosed, those skilled in the art can easily adjust the large Oken type smoothness adopted in the present invention. For example, the Oken type smoothness of 210 seconds or more is specifically shown by an example or the like, but can be adjusted by one of the following methods or a combination of these methods. (1) Adjustment of beating condition The beating condition is adjusted so that the pulp fiber length after beating is, for example, 0.40 to 0.70 mm, preferably 0.50.
Adjust to 0.65 mm. (2) Surface Calendering The surface of the base paper is calendered to make the density of the base paper dense. For example, the density of the base paper is preferably 0.80 to
1.15 g / cm ³ , more preferably 0.90 to 1.
It is suitable to set it to 10 g / cm ³ . In order to efficiently increase the surface smoothness, the temperature in the calendar treatment (calender roll temperature) is, for example, 90 to 18
It is preferable to adjust the temperature to 0 ° C, preferably 110 to 160 ° C.

In the present invention, in addition to the Oken type smoothness, a Steckigt sizing degree that is much larger than the base paper used for the conventional electrophotographic image-receiving paper is used. I am trying. Specifically, the Steckigt sizing degree used in the present invention is 100 seconds or longer, preferably 150 seconds or longer. By using such a large Steckigt sizing degree, the intended purpose of the present invention can be sufficiently achieved. The Steckigt sizing degree is a sizing degree defined by JIS P8122. Specifically, the Steckigt sizing degree is 2
% On the rhodan ammonium solution,
One drop of 1% ferric chloride solution is dropped on it, and the time until the appearance of red spots is measured and displayed in seconds. Therefore, the longer this time is, the larger the size characteristic of suppressing the permeation of the solution is.

Once the present invention is disclosed, one of ordinary skill in the art can readily
The size can be adjusted. For example, the Steckigt sizing degree of 50 seconds or more is specifically shown by an example or the like, but can be adjusted by one of the following methods or a combination of these methods. (1) Adjustment of sizing agent For example, the sizing agent is used in an amount of 0.1 to 2.0% by mass, preferably 0.3 to 1.5% by mass based on the mass of pulp. This can significantly reduce the wettability of the base paper. Further, preferably, as the sizing agent, a compound containing a higher fatty acid such as an alkyl ketene dimer, alkenyl succinic anhydride (ASA), and epoxidized fatty acid amide is used. (2) Adjustment of Porosity of Base Paper The density of the base paper is set to 0.8 g / cm ³ or more, preferably 0.85 g, for example, by calendering, as in the case of Oken type smoothness. / Cm ³ or more. As an upper limit, for example, about 1.15 g / cm ³ will be appropriate.

In general, it is known that the "strain" of paper differs based on the difference in the beating mode. After the beating, the elastic force (rate) of the paper made into paper is the extent of the "strain" of the paper. Can be used as an important factor that represents In particular, the elastic modulus of the paper Can be obtained from the following formula. E = ρc ² (1-n ² ) [E: dynamic elastic modulus, ρ: density, c: speed of sound in paper, n: Poisson's ratio]

Further, in the case of ordinary paper, since n = 0.2, it can be calculated without much difference even if it is calculated by the following formula. E = ρc ² , that is, if the density and the speed of sound of the paper can be measured, the elastic modulus can be easily obtained. In the above formula, when measuring the sound velocity, various known devices such as Sonic Tester SST-110 type (manufactured by Nomura Shoji Co., Ltd.) can be used.

The basis weight of the base paper is, for example, 50 to 250 g /
m ² , preferably in the range of 100 to 180 g / m ² . As the base paper, specifically, high-quality paper,
For example, edited by The Photographic Society of Japan, "Basics of Photographic Engineering -Silver Salt Photo-", published by Corona Co., Ltd. (1979) (223)-
Suitable examples include paper described on page (240). A plurality of base papers may be used. Further, on both sides or one side of the base paper, for the purpose of improving the adhesiveness with the polypropylene resin layer described later provided on the base paper, activation such as corona discharge treatment, flame treatment, glow discharge treatment, or plasma treatment is performed. It is preferable to apply a treatment.

<Toner Image Receiving Layer> In the present invention, a toner image receiving layer is provided on at least one surface of the base paper. As the toner image receiving layer, various materials and forms can be used as long as they do not substantially contain a pigment. The thermoplastic resin may be laminated on the surface of the base paper, for example, by a melt laminating method, or a coating solution may be applied. Among these, the coating of the coating liquid is preferable because it can be easily performed. As the coating liquid, it is suitable that the base paper has a predetermined amount of the thermoplastic resin that penetrates from the surface of the base paper to form a toner image-receiving layer having a predetermined thickness on the surface of the base paper. Is. At such a predetermined depth, when the thermoplastic resin has penetrated into the base paper, the base paper,
The toner image-receiving layer can be firmly adhered to and the occurrence of blisters can be prevented. Further, the moisture resistance is improved, and the curl resistance is improved even at high temperature during fixing.

The toner image-receiving layer used in the present invention receives the toner for forming an image from the developing drum or the intermediate transfer member by (static) electricity, pressure, etc. in the transfer step and heats it in the fixing step. It has the function of fixing by pressure. The toner image-receiving layer used in the present invention may contain various additives together with the thermoplastic resin as long as the action as the toner image-receiving layer is not affected. The thickness of the toner image receiving layer is
1/2 or more of the particle diameter of the toner used, preferably,
A thickness of 1 to 3 times is appropriate. Further, as the toner image receiving layer, JP-A-5-216322 and 7-
Those having the thickness disclosed in each publication of No. 301939 are preferable. Specifically, the thickness is, for example, 1 to 50 μm, preferably 5 to 15 μm.

The toner image-receiving layer preferably has physical properties of one of the following items, more preferably a plurality of items, and most preferably all of the items. (1) Tg (glass transition temperature) of the toner image receiving layer is 30 ° C.
As described above, the toner has a Tg of + 20 ° C. or less. (2) T1 / 2 (1/2 method softening point) of the toner image receiving layer is
The temperature is 60 to 200 ° C, preferably 80 to 170 ° C.
Here, the 1/2 method softening point is a residual heat time, for example, 300 seconds, at an initial set temperature (for example, 50 ° C.), under a specific condition, under a specific condition, while applying a predetermined extrusion load. After that, the temperature is evaluated at a temperature that is one half of the difference between the piston strokes at the start and the end of the outflow at each temperature when the temperature is raised at a predetermined constant heating rate. (3) Tfb (outflow start temperature) of the toner image receiving layer is 40
˜200 ° C., preferably Tfb of the toner image receiving layer is Tfb + 50 ° C. or less of the toner. (4) The temperature at which the viscosity of the toner image receiving layer reaches 1 × 10 ⁵ CP is 40 ° C. or higher, which is lower than that of the toner. (5) The storage elastic modulus (G ′) at the fixing temperature of the toner image receiving layer is 1 × 10 ² to 1 × 10 ⁵ Pa, and the loss elastic modulus (G ″) is 1 × 10 ² to 1 × 10 ⁵ Pa. (6) The loss tangent (G ″ / G ′), which is the ratio of the loss elastic modulus (G ″) at the fixing temperature of the toner image receiving layer and the storage elastic modulus (G ′), is 0.01 to 10. (7) The storage elastic modulus (G ′) at the fixing temperature of the toner image receiving layer is −50 to +2500 with respect to the storage elastic modulus (G ″) at the fixing temperature of the toner. (8) The inclination angle of the molten toner on the image receiving layer is 50 degrees or less,
Particularly, it is 40 degrees or less. Further, as the toner image receiving layer,
Japanese Patent No. 2788358, JP-A-7-24863
Those satisfying the physical properties disclosed in No. 7, No. 8-305067, No. 10-239889 and the like are preferable.

The physical property (1) can be measured by a differential scanning calorimeter (DSC). (2)
The physical properties of (4) to (4) can be measured using, for example, a flow tester CFT-500 or 500D manufactured by Shimadzu Corporation. The physical properties (5) to (7) can be measured using a rotary rheometer (for example, dynamic analyzer RADII manufactured by Rheometrics). The physical properties (8) can be measured by the method disclosed in JP-A-8-334916, using a contact angle measuring device manufactured by Kyowa Interface Science Co., Ltd.

The thermoplastic resin used in the toner image-receiving layer of the present invention may be any one as long as it is deformable at the fixing temperature and can receive the toner. Preferably, the thermoplastic resin used in the toner image receiving layer is a resin of the same type as the resin used as the binder of the toner. In the toner, most of polyester resins, styrene-acrylic acid ester copolymers, styrene-methacrylic acid ester copolymers and the like are used, and in that case, as a thermoplastic resin used in the toner image-receiving layer of the present invention. Also, it is preferable to use a thermoplastic resin such as a polyester resin, a styrene-acrylic acid ester copolymer, or a styrene-methacrylic acid ester copolymer.

Examples of such a thermoplastic resin include the following thermoplastic resins. (A) Having an ester bond Terephthalic acid, isophthalic acid, maleic acid, fumaric acid,
Dicarboxylic acid components such as phthalic acid, adipic acid, sebacic acid, azelaic acid, abietic acid, succinic acid, trimellitic acid, pyromellitic acid (these carboxylic acid groups are substituted with sulfonic acid groups, carboxyl groups, etc. Good) and ethylene glycol, diethylene glycol,
Propylene glycol, bisphenol A, a diether derivative of bisphenol A (for example, bisphenol A
Alcohol components such as ethylene oxide 2 adduct of bisphenol A, propylene oxide 2 adduct of bisphenol A), bisphenol S, 2-ethylcyclohexyldimethanol, neopentyl glycol, cyclohexyldimethanol, glycerin (these alcohol components include hydroxyl groups, etc. May be substituted), a polyester resin obtained by condensation with polymethyl methacrylate,
Polybutyl methacrylate, polymethyl acrylate,
Specific examples include polyacrylic acid ester resins such as polybutyl acrylate or polymethacrylic acid ester resins, polycarbonate resins, polyvinyl acetate resins, styrene acrylate resins, styrene-methacrylic acid ester copolymer resins, vinyl toluene acrylate resins, and the like. JP-A-59-101395 and 63-7971.
63, 7973, 63-7973, 60
The thing described in No. 294862 can be mentioned.
As commercially available products, Toyon Byron 290, Byron 200, Byron 280, Byron 300, Byron 103, Byron GK-140, Byron GK-13.
0, Kao Tuffton NE-382, Tuffton U-5,
ATR-2009, ATR-2010, Unitika made Elitel UE3500, UE3210, XA-815
3, Polyester TP-220, R- manufactured by Nippon Synthetic Chemical Industry
188 etc. can be used.

(B) Polyolefin resins such as polyethylene resins and polypropylene resins, copolymer resins of olefins such as ethylene and propylene with other vinyl monomers, acrylic resins and the like. (C) Polyurethane resin and the like can be mentioned. (D) Polyamide resin, urea resin and the like can be mentioned. (E) Polysulfone resin and the like can be mentioned. (F) Polyvinyl chloride resin, polyvinylidene chloride resin,
Examples thereof include vinyl chloride-vinyl acetate copolymer resins and vinyl chloride-vinyl propionate copolymer resins. (G) Polyol resins such as polyvinyl butyral, cellulose resins such as ethyl cellulose resin, cellulose acetate resin, and the like. (H) Polycaprolactone resin, styrene-maleic anhydride resin, polyacrylonitrile resin, polyether resin, epoxy resin, phenol resin and the like can be mentioned. The thermoplastic resins may be used alone or as a mixture of these thermoplastic resins. Such a thermoplastic resin is usually 20% by mass or more, preferably 30 to 100% by mass, based on the mass of the toner image-receiving layer.
It is suitable to be blended.

The toner image-receiving layer used in the present invention constitutes a layer of thermoplastic resin on the surface of the base paper, and the thermoplastic resin constituting the toner image-receiving layer has a predetermined depth in the base paper. Now, preferably it is present. The depth at which the thermoplastic resin exists is, for example, from the surface to a depth of 1/100 or more, preferably 1/2 with respect to the thickness of the base paper.
It is suitable that it penetrates to the above depth and exists in the base paper. When the thermoplastic resin is present in such a range, an electrophotographic image-receiving paper that gives a stable and clear toner image without causing blister between the base paper and the toner image-receiving layer is obtained. Can be provided. In this case, the thermoplastic resin forming the toner image-receiving layer may form a concentration gradient of the thermoplastic resin in the base paper over its depth, or in a uniform or non-uniform state. It may exist.

On the other hand, the thermoplastic resin forming the toner image receiving layer is, for example, 1/10 from the surface with respect to the thickness of the base paper.
If the depth of less than 0, preferably less than 1/500, is present close to the surface of the base paper and further penetrates into the base paper, the glossiness of the resulting electrophotographic image-receiving paper is improved. Further improvement may be preferable. Also in this case, the thermoplastic resin forming the toner image-receiving layer may form a concentration gradient of the thermoplastic resin in the base paper over its depth, or in a uniform or non-uniform state. May exist in.

As a method of allowing the thermoplastic resin forming the toner image receiving layer to exist at such a predetermined depth, for example, a coating liquid forming the toner image receiving layer is applied to the surface of the base paper and dried. There is. However, it is necessary to consider the characteristics of the coating liquid depending on the depth in which the thermoplastic resin is present. For example, when the thermoplastic resin is permeated to a deeper position and is allowed to exist, the viscosity of the coating liquid is, for example, 30 mPa · s or more, preferably 60 m
It is preferable that it is not less than Pa · s. The surface tension of the coating liquid is, for example, 50 mN / m or less, preferably 3
It is suitable to be 5 mN / m or less.

In other words, the type of the thermoplastic resin that constitutes the coating liquid, the type of any additive that is added as necessary,
The thermoplastic resin forming the toner image-receiving layer in the base paper at a desired depth is continuously formed from the toner image-receiving layer by adjusting the viscosity and physical properties as described above in consideration of characteristics and the like. Can be present at. In addition, the coating liquid is, for example, within 2 minutes after coating, preferably 1
It is suitable to dry within minutes, more preferably within 30 seconds. The end point of the drying may be, for example, a point at which the temperature of the coated surface becomes the same as the wet-bulb temperature of the drying atmosphere.

Further, it is preferable to carry out calendering after coating the coating solution and drying. The pressure in the calendar processing is, for example, 98 N / cm (10 kgf / cm)
Above, more preferably, 294 N / cm (30 kgf /
cm) or more is suitable. The upper limit is not particularly limited and is, for example, 490 N / cm. It is suitable that the temperature in the calendar treatment is 12 ° C. or lower, preferably 100 ° C. or lower. The lower limit is not particularly limited and is, for example, 20 ° C. The calendering process is appropriately performed using, for example, a pair of pressure rolls. At this time, one surface of the pair of pressure rolls has a high smoothness (metal surface), and the other surface is an elastic surface such as plastic or rubber. It is suitable to carry out a super calendering treatment in which one surface of the pressure roll has a high smoothness (metal surface) and the other surface is an elastic surface such as cotton or paper.
Further, a combination of a belt and a roller may be used in which an electrophotographic image-receiving paper having a toner image-receiving layer that image-wise receives toner is heated between the roller and the belt and then cooled.

As the thermoplastic resin used in the toner image-receiving layer, Japanese Patent Publication Nos. 5-127413 and 8-19439 are available.
No. 4, No. 8-334915, No. 8-334916,
Those satisfying the physical properties disclosed in JP-A-9-171265 and JP-A-10-221877 are preferably used. The thermoplastic resin used in the toner image-receiving layer of the present invention is preferably one that can satisfy the above-mentioned physical properties of the image-receiving layer in the state where the image-receiving layer is formed. More preferably, the resin alone can satisfy the above-mentioned physical properties preferable for the toner image receiving layer. Further, two or more resins having different physical properties described above can be used in combination.

As the thermoplastic resin used in the toner image-receiving layer, those having a molecular weight larger than that of the thermoplastic resin used in the toner are preferably used. However, regarding the molecular weight, the above-mentioned relation of the molecular weight is not always preferable depending on the relation of the thermodynamic characteristics of the toner resin and the thermoplastic resin used for the toner image receiving layer. For example, when the softening temperature of the thermoplastic resin used in the toner image receiving layer is higher than that of the toner resin, it may be preferable that the molecular weight is the same or the thermoplastic resin in the toner image receiving layer is smaller. As the thermoplastic resin used in the toner image-receiving layer, it is also preferable to use a mixture of resins having the same composition but different average molecular weights. Further, the relationship with the molecular weight of the thermoplastic resin used in the toner is preferably the relationship disclosed in JP-A-8-334915. The molecular weight distribution of the thermoplastic resin used in the toner image receiving layer is preferably wider than the molecular weight distribution of the thermoplastic resin used in the toner.

The thermoplastic resin used in the toner image-receiving layer may be either water-soluble or water-dispersible when used as a coating liquid. The water-soluble thermoplastic resin is not particularly limited in its composition, bond structure, molecular structure, molecular weight, molecular weight distribution, morphology, etc., as long as it is water-soluble. In order to make the thermoplastic resin water-soluble, for example, the thermoplastic resin needs to have a water-solubilizing group, and examples of the water-solubilizing group include, for example, a hydroxyl group, a carboxylic acid group, and an amino group. Groups, amide groups, ether groups and the like. Examples of water-soluble thermoplastic resins include Research Disclosure No. 17,643, pages 26 and 18, 71.
No. 6, page 651, No. 307, 105, 873-874.
Pages and pages (71) to (75) of JP-A-64-13546.
The thing described in the page is mentioned. Specifically, as the water-soluble thermoplastic resin, for example, vinylpyrrolidone-vinyl acetate copolymer, styrene-vinylpyrrolidone copolymer, styrene-maleic anhydride copolymer, water-soluble polyester, water-soluble polyurethane, Water-soluble nylon, water-soluble epoxy resin, etc. can be used.

As the water-dispersible thermoplastic resin, acrylic resin emulsion, polyvinyl acetate emulsion, S
A BR (styrene / butadiene / rubber) emulsion, a polyester resin emulsion, a polystyrene resin emulsion, a urethane resin emulsion, or the like is appropriately selected, and two or more kinds can be combined. In the case of gelatin, it can be selected from lime-processed gelatin, acid-processed gelatin, and so-called demineralized gelatin with a reduced content of calcium and the like, depending on the purpose.

When the binder of the toner is a polyester resin, a polyester resin is preferable as the resin for the toner image receiving layer. As commercially available polyester resin,
For example, Toyron Byron 290, Byron 200,
Byron 280, Byron 300, Byron 103, Byron GK-140, Byron GK-130, Kao's Tuffton NE-382, Tuffton U-5, ATR-20.
09, ATR-2010, Unitika made Elitel UE
3500, UE3210, XA-8153, Polyester TP-220, R-188 manufactured by Nippon Synthetic Chemical Industry. Commercially available trade names of the acrylic resin are DIANAL SE-5437 and SE manufactured by Mitsubishi Rayon Co., Ltd.
-5102, SE-5377, SE-5649, SE-
5466, SE-5482, HR-169, 124, H
R-1127, HR-116, HR-113, HR-1
48, HR-131, HR-470, HR-634, H
R-606, HR-607, LR-1065, 574,
143, 396, 637, 162, 469, 216, B
R-50, BR-52, BR-60, BR-64, BR
-73, BR-75, BR-77, BR-79, BR-
80, BR-83, BR-85, BR-87, BR-8
8, BR-90, BR-93, BR-95, BR-10
0, BR-101, BR-102, BR-105, BR
-106, BR-107, BR-108, BR-11
2, BR-113, BR-115, BR-116, BR
-117, Sekisui Chemical Co., Ltd. S-REC P SE-002
0, SE-0040, SE-0070, SE-010
0, SE-1010, SE-1035, Sanyo Kasei Kogyo Heimer ST95, ST120, Mitsui Chemicals FM601 etc. can be used. Examples of commercially available polyester emulsions include Vylonal MD-1250 manufactured by Toyobo,
MD-1930, Plus Coat Z-446 manufactured by Mutual Chemical
Z-465, RZ-96, ES-61 manufactured by Dai Nippon ink
1, ES-670, pine resin A-160 made by Takamatsu Yushi
P, A-210, A-515GB, A-620 etc. are mentioned suitably. The film forming temperature of the thermoplastic resin is preferably room temperature or higher for storage before printing, and 100 ° C. or lower for fixing the toner particles.

In the toner image-receiving layer used in the present invention, in addition to the above thermoplastic resin, various additives may be oriented for the purpose of improving the thermodynamic characteristics of the toner image-receiving layer. Examples of such additives include plasticizers, slip agents or release agents, cross-linking agents, emulsions and dispersions.
As the plasticizer, known plasticizers for resins can be used without particular limitation. The plasticizer has a function of adjusting fluidity or softening of the toner image-receiving layer by heat and / or pressure when fixing the toner. As a plasticizer, "Chemical Handbook" (edited by The Chemical Society of Japan, Maruzen), "Plasticizer-Theory and its Applications-" (edited by Koichi Murai, Koushobo), "Study on plasticizers", "Research on plasticizers" It can be selected by referring to "Lower" (edited by Japan Society of Polymer Chemistry), "Handbook Rubber / Plastic Blended Chemicals" (edited by Rubber Digest).

Some plasticizers are described as high-boiling point organic solvents, heat solvents, etc .;
-83154, 59-178451, 59-1
78453, 59-178454, 59-17.
No. 8455, No. 59-178457, No. 62-174.
No. 754, No. 62-245253, No. 61-2094.
No. 44, No. 61-200538, No. 62-8145.
No. 62-9348 No. 62-30247 No. 62
-136646, 62-174754, 62-
No. 245253, No. 61-209444, No. 61-2
No. 00538, No. 62-8145, No. 62-9348.
No. 62-30247, No. 62-136646,
Esters such as those described in JP-A-2-235694 (for example, phthalic acid esters, phosphoric acid esters, fatty acid esters, abietic acid esters, adipic acid esters, sebacic acid esters, Azelaic acid ester, benzoic acid ester, butyric acid ester, epoxidized fatty acid ester, glycolic acid ester, propionic acid ester, trimellitic acid ester, citric acid ester, sulfonic acid ester, carboxylic acid ester , Succinic acid esters, maleic acid esters, fumaric acid esters, phthalic acid esters, stearic acid esters, etc.), amides (eg, fatty acid amides, sulfamides, etc.), ethers, alcohols, lactones , Compounds such as polyethyleneoxy It is. The plasticizer can be used as a mixture with the resin.

As the plasticizer, a polymer having a relatively low molecular weight can be used. In this case, the molecular weight is preferably lower than that of the binder resin to be plasticized, and the molecular weight is suitably 15,000 or less, preferably 5000 or less. Further, in the case of the polymer plasticizer, it is preferable that the same kind of polymer as the binder resin to be plasticized. For example, a low molecular weight polyester is preferable for plasticizing the polyester resin. Furthermore, oligomers can also be used as plasticizers. In addition to the compounds listed above, commercially available products such as Adeka Sizer PN-170 and PN- manufactured by Asahi Denka Co., Ltd.
1430 and C.I. P. HALL's product PARAPLEX
-G-25, G-30, G-40, Rika Hercules product ester gum 8L-JA, ester R-95, pentaline 4851, FK115, 4820, 830, Louisol 28-JA, picolastic A75, picotex LC, crista. Rex 3085 and the like can be mentioned.

The plasticizer is a stress or strain generated when the toner particles are embedded in the toner image-receiving layer (physical strain such as elastic force and viscosity, strain due to material balance of molecules, binder main chain, pendant portion, etc.). Can optionally be used to mitigate The plasticizer may be in a state of being microscopically dispersed in the toner image-receiving layer, in a state of microscopically phase-separating into a sea-island shape, or in a state of being sufficiently mixed and dissolved with other components such as a binder. The plasticizer is, for example, 0.001 to 9 based on the mass of the toner image receiving layer.
It is preferable to add 0% by mass, preferably 0.1 to 60% by mass, and particularly preferably 1 to 40% by mass. In addition, the plasticizer is used to adjust the slipperiness (improvement of transportability due to reduction of frictional force), improve the offset of the fixing portion (peeling of toner or layer to the fixing portion), adjust the curl balance, adjust the charge (electrostatic image of toner). Formation) and the like.

The slipping agent or releasing agent which can be optionally used in the present invention is added for the purpose of preventing the electrophotographic image-receiving paper of the present invention from adhering to the fixing heating member during fixing. Particularly, the 180 ° peel strength of the toner image-receiving layer with the fixing member at the fixing temperature is 0.1 N / 25 mm or less, and more preferably 0.041 N / 25 mm or less. The 180-degree peel strength can be measured by using the surface material of the fixing member in accordance with the method described in JIS K6887. Examples of the slip agent or release agent used in the electrophotographic image-receiving paper of the present invention include higher alkyl sodium sulfate, higher fatty acid higher alcohol ester, carbowax, higher alkyl phosphate ester, silicone compound, modified silicone, curability. Silicone etc. are included. Further, polyolefin wax, fluorine-based oil, fluorine-based wax, carnauba wax, microcrystalline wax, and silane compound are also preferably used.

As to the slipping agent or releasing agent which can be used, US Pat.
No. 3,850,640 and French Patent 2180465.
No., British Patent Nos. 955061, 1143118, 1263722, 1270578, 13205.
No. 64, No. 1320757, No. 2588765, No. 2739891, No. 3018178, No. 30425.
No. 22, No. 3080317, No. 3082087, No. 3121060, No. 3222178, No. 32959.
No. 79, No. 3489567, No. 3516832, No. 3658573, No. 3679411, No. 38705.
21 and JP-A-49-5017 and 51-
141623, 54-159221, 56-8
No. 1841 and Research Disclosure 13969.

The amount of the slip agent or the release agent used is 5 to 500.
mg / ^{m 2,} is preferably a suitably be 10 to 200 mg / ^{m 2.} In the case of so-called oilless fixing, which does not use an oil for the purpose of preventing offset to the fixing member in the fixing section, the preferable amount of the lubricant or the releasing agent is, for example, 30 to 3000 mg / m ² , and preferably 100.
˜1500 mg / m ² . Since wax-based slip agents or release agents are difficult to dissolve in organic solvents, it is preferable to prepare an aqueous dispersion, prepare a dispersion with a thermoplastic resin solution, and apply the dispersion. In this case, the wax-based slip agent or release agent is present in the thermoplastic resin in the form of fine particles. In this case, the amount of the lubricant used is 5 to 10000 mg / m ² ,
It is preferably 50 to 5000 mg / m ² . Examples of the slip agent or release agent include silicone compounds and
Examples thereof include fluorine compounds and wax.

As the slipping agent or releasing agent, generally, compounds described in Koshobo “Revised Wax Properties and Applications” and Silicone Handbook published by Nikkan Kogyo Shimbun can be used. In addition, Japanese Examined Patent Publication No. 59-38581, Japanese Examined Patent Publication No. 4-32380, No. 2838498 and 29
49558, JP-A-50-117433, 52-
52640, 57-148755, 61-62.
056, 61-62057, 61-11876.
No. 0, JP-A-2-42451, JP-A-3-41465,
4-212175, 4-214570, 4-
263267, 5-34966, 5-1195.
No. 14, No. 6-59502, No. 6-161150,
6-175396, 6-21904, 6-
230600, 6-295093, 7-362
No. 10, No. 7-43940, No. 7-56387, No. 7-56390, No. 7-64335, No. 7-199.
No. 681, No. 7-223362, No. 7-287413.
No. 8, No. 8-184992, No. 8-227180, No. 8-248671, No. 8-248799, No. 8-2.
No. 48801, No. 8-278663, No. 9-1527.
39, 9-160278, 9-185181.
No. 9, No. 9-319139, No. 9-319143, No. 10-20549, No. 10-48889, No. 10-.
198069, 10-207116, 11-2
No. 917, No. 11-44969, No. 11-65156.
No. 11-73049 and No. 11-194542, the silicone compounds used in the toner, fluorine compounds, waxes, and the like are preferably used.
Also, a plurality of these compounds may be used in combination.

Specifically, examples of the silicone compound include unmodified silicone oil as silicone oil (specifically, dimethylsiloxane oil, methyl hydrogen silicone oil, phenylmethyl silicone oil, and Shin-Etsu as a commercial product). Chemical Industry KF-
96, KF-96L, KF-96H, KF-99, KF
-50, KF-54, KF-56, KF-965, KF
-968, KF-994, KF-995, HIVAC
F-4, F-5, Toray Dow Corning Silicone SH200, SH203, SH490, SH510, S
H550, SH710, SH704, SH705, SH
7028A, SH7036, SM7060, SM700
1, SM7706, SH7036, SH8710, SH
1107, SH8627 and the like.

Examples of the fluorine compound include fluorine oil (commercially available product: Daifloil # 1, manufactured by Daikin Industries,
# 3, # 10, # 20, # 50, # 100, Unidyne TG-440, TG-452, TG-490, TG-5
60, TG-561, TG-590, TG-652, T
G-670U, TG-991, TG-999, TG-3
010, TG-3020, TG-3510, Tochem Products MF-100, MF-110, MF-12.
0, MF-130, MF-160, MF-160E, Asahi Glass Surflon S-111, S-112, S-11.
3, S-121, S-131, S-132, S-14
1, S-145, Mitsui Fluorochemicals FC-430,
FC-431 etc.), fluororubber (Toray as a commercial product.
Dow Corning Recone's LS63U, etc., Fluorine modified resin (commercially available NOF MODIPER F20)
0, F220, F600, F2020, F3035, and Dainichiseika dialomers FF203 and FF204.

Examples of the wax include paraffin wax as petroleum wax (paraffin wax 155, 150, 140, 135, 1 manufactured by Nippon Seiro Co., Ltd. as a commercial product).
30, 125, 120, 115, HNP-3, HNP-
5, HNP-9, HNP-10, HNP-11, HNP
-12, HNP-14G, SP-0160, SP-01
45, SP-1040, SP-1035, SP-304
0, SP-3035, NPS-8070, NPS-L-
70, OX-2151, OX-2251, EMUSTA
R-0384, EMUSTAR-0136, Cerozole 686, 428, 651-A, A, H-80 manufactured by Chukyo Yushi Co., Ltd.
3, B-460, E-172, 866, K-133, Hydrin D-337, E-139, Nisseki Mitsubishi Petroleum 12
5 ° paraffin, 125 ° FD, 130 ° paraffin,
Suitable examples include 135 ° paraffin, 135 ° H, 140 ° paraffin, 140 ° N, 145 ° paraffin, and paraffin wax M). Examples of the slip agent or release agent optionally added to the toner image-receiving layer of the present invention include:
These derivatives, oxides, purified products, and mixtures can also be used. Moreover, these may have a reactive substituent. The slip agent or release agent used in the present invention is
Based on the mass of the toner image receiving layer, for example, 0.1 to 1
It is suitable to be 0% by mass, preferably 0.3 to 8.0% by mass, and particularly preferably 0.5 to 5.0% by mass.

The toner image-receiving layer of the present invention preferably has a content of 40% by mass or less, preferably 40% by mass or less, based on the mass of the thermoplastic resin constituting the toner image-receiving layer, within a range that does not impair the intended purpose of the present invention. Can be optionally added with an organic or inorganic pigment or filler in an amount of 30% by weight or less, more preferably less than 20% by weight. Particularly preferably, it is desirable that the pigment or the filler is substantially not contained. If the pigment or filler is less than 40% by mass,
Image quality and gloss are improved, which is preferable. As the pigment or filler that can be included, known reinforcing agents for binder resins, fillers, and reinforcing materials can be used.
The filler can be selected with reference to "Handbook Rubber / Plastic Compounding Chemicals" (edited by Rubber Digest), "New Edition Plastic Compounding Agents Basics and Applications" (Taisei), "Filler Handbook" (Taisei), etc. it can.

As the pigment or filler, various inorganic pigments or fillers can be used. Examples of the inorganic pigment include titanium dioxide, silica, alumina, zinc oxide, zirconium oxide, micaceous iron oxide, lead white, lead oxide, cobalt oxide, strontium chromate, molybdenum-based pigment, smectite, magnesium oxide, calcium oxide, carbonic acid. Examples include calcium and mullite.
As the filler, silica and alumina are particularly preferable. You may use together 2 or more types of fillers.

The toner image-receiving layer of the present invention preferably contains a charge adjusting agent in order to adjust the transfer and adhesion of the toner and to prevent electrostatic adhesion of the toner image-receiving layer. As the charge control agent, various conventionally known charge control agents can be used. Examples of such a charge control agent include, for example, cationic surfactants, anionic surfactants, amphoteric surfactants, surfactants such as nonionic surfactants, and the like, as well as polymer electrolytes and conductive metal oxides. Etc. can be used. For example, quaternary ammonium salts, polyamine derivatives, cation-modified polymethylmethacrylate, cation-modified polystyrene and other cationic antistatic agents, alkyl phosphates, anionic polymers and other anionic antistatic agents, fatty acid esters, polyethylene oxide and other nonionics. Examples thereof include, but are not limited to, system antistatic agents.

When the toner has a negative charge, the toner image is received.
Examples of the charge control agent blended in the layer include cations.
And nonionic are preferred. Examples of conductive metal oxides
For example, ZnO, TiO_Two, SnO_Two, Al_TwoO _Three, In
_TwoO_Three, SiO_Two, MgO, BaO, MoO_ThreeEtc.
You can These conductive metal oxides alone
May be used, or may be used with these complex oxides
Yes. Moreover, the metal oxide may further contain a different element.
Well, for example, for ZnO, Al, In, etc., TiO
_TwoFor Nb, Ta, etc., SnO_TwoFor Sb,
Containing (doping) Nb, halogen element, etc.
You can

The toner image-receiving layer used in the present invention is 1 ×
It is preferable to have a surface electric resistance in the range of 10 ⁶ to 1 × 10 ¹⁵ Ω (under the conditions of 25 ° C. and 65% RH). 1
When it is less than × 10 ⁶ Ω, the toner amount when the toner is transferred to the toner image receiving layer is not sufficient, and the density of the obtained toner image tends to be low. On the other hand, the surface electric resistance is 1 × 1
If it exceeds 0 ¹⁵ Ω, an excessive charge is generated during transfer, the toner is not transferred sufficiently, the image density is low, and electrostatic charge is generated during handling of the electrophotographic image-receiving paper, causing dust to adhere. This is not preferable because it easily occurs and misfeeds, double feeding, discharge marks, toner transfer gaps and the like are likely to occur during copying.

The optimum surface electric resistance of the transparent toner image-receiving layer is in the range of 10 ¹⁰ to 10 ¹³ Ω / cm ² , preferably
It is 5 × 10 ^{10 to} 5 × 10 ¹² Ω / cm ² , and the amount of the antistatic agent used may be such that the surface electric resistance value falls within this range. The surface electric resistance of the surface of the support opposite to the toner image-receiving layer is 5 × 10 ^{8 to} 3.2 × 1.
0 ¹⁰ Ω / cm ² , preferably 1 × 10 ⁹ to 1 × 10
¹⁰ Ω / cm ² is suitable. The measurement of surface electrical resistance is
In accordance with JIS K 6911, the sample temperature 20
By adjusting the humidity for 8 hours or more in an environment of ℃, humidity of 65%, using the R8340 manufactured by Advantest Co., Ltd. in the same environment, under the condition of applied voltage of 100V, after conducting for 1 minute after conducting electricity, it is possible to measure. can get.

The toner image-receiving layer used in the electrophotographic image-receiving paper of the present invention contains the toner image-receiving layer for the purpose of improving image quality, particularly whiteness.
A fluorescent whitening agent, a white pigment, a colored pigment, a dye or the like can be used. Optical brighteners have absorption in the near-ultraviolet region and 4
As a compound which emits fluorescence in the range of 00 to 500 nm, various known fluorescent whitening agents can be used without particular limitation. Examples of optical brighteners include K.I. "The Chemistry of Syntheti"
Preferred examples thereof include the compounds described in "C Dyes", Volume V, Chapter 8. Specific examples include stilbene compounds, coumarin compounds, biphenyl compounds, benzoxazoline compounds, naphthalimide compounds, pyrazoline compounds, carbostyryl compounds, and the like. Examples of these are Sumitomo Chemical's white full fur PSN, PHR, HCS, PCS, B, Ciba-
Geitey's UVITEX-OB etc. are mentioned.

As the white pigment, the inorganic pigments (titanium oxide, calcium carbonate, etc.) described in the section of the filler can be used. As a colored pigment, JP-A-63-4465 can be used.
Various pigments and azo pigments (azo lake; carmine 6B, red 2B, insoluble azo; monoazo yellow, disazo yellow, pyrazolo orange, vulcan orange, condensed azo type; chromophthal yellow, chromophthal red ), Polycyclic pigments (phthalocyanine type; copper phthalocyanine blue, copper phthalocyanine green, cioxazine type; dioxazine violet,
Isoindolinone type; isoindolinone yellow, slene type; perylene, perinone, flavantron, thioindigo, lake pigments (malachite green, rhodamine B, rhodamine G, Victoria blue B) and inorganic pigments (oxide, titanium dioxide, red iron oxide, Sulfate; Precipitating barium sulfate, carbonate; Precipitating calcium carbonate, silicate;
Hydrous silicate, anhydrous silicate, metal powder; aluminum powder, bronze powder, zinc dust, carbon black, yellow lead, navy blue, and the like.

As the dye, various known dyes can be used. Examples of oil-soluble dyes include anthraquinone compounds and azo compounds. Specific examples of the water-insoluble dye include C.I. I. Vat Violet 1,
C. I. Vat Violet 2, C.I. I. Vat Violet 9, C.I. I. Vat Violet 13,
C. I. Vat Violet 21, C.I. I. Vat Blue 1, C.I. I. Vat Blue 3, C.I. I. Vat Blue 4, C.I. I. Vat Blue 6, C.I. I. Vat Blue 14, C.I. I. Vat Blue 20, C.I. I. Vat blue 35 and other vat dyes, C.I. I. Disperse Violet 1, C.I. I. Disperse Violet 4, C.I.
I. Disperse Violet 10, C.I. I. Disperse Blue 3, C.I. I. Disperse Blue 7, C.I.
I. Disperse dyes such as Disperse Blue 58, C.I. I. Solvent Violet 13, C.I. I. Solvent Violet 14, C.I. I. Solvent Violet 2
1, C.I. I. Solvent Violet 27, C.I. I.
Solvent Blue 11, C.I. I. Solvent Blue 1
2, C.I. I. Solvent Blue 25, C.I. I. There are oil-soluble dyes such as Solvent Blue 55.

Colored couplers used in silver salt photography can also be preferably used. The toner image forming surface of the electrophotographic image receiving paper of the present invention preferably has high whiteness. The whiteness is CIE 1976 (L ^* a ^*
In the b ^* ) color space, the L ^* value is preferably 80 or more, more preferably 85 or more, and further preferably 9
It is 0 or more. The a ^* value is preferably −2 or more and 2 or less, and more preferably −1.5 or more and 1 or less. The b ^* value is preferably −10 or more and 2 or less, more preferably −7 or more and 2 or less. Further, it is preferable that the white tint is as neutral as possible. The white tint is (a ^* ) ² + (b ^* ) in the L ^* a ^* b ^* space.
The value of ² is preferably 50 or less, more preferably 18 or less, and further preferably 5 or less. In addition, L ^* a ^* b ^*
The values are measured by Hitachi Color Analyzer C-2000.

The glossiness of the toner image forming surface of the electrophotographic image-receiving paper of the present invention is preferably 20 or more, more preferably 30 or more. Further, the toner image-receiving layer of the present invention preferably has high gloss. As for the glossiness, it is preferable that the glossiness at 45 degrees is 60 or more in the entire region from white without toner to black with maximum density, and more preferably,
It is 75 or more, more preferably 90 or more. However,
The glossiness is preferably 110 or less. If it exceeds 110, metallic luster appears, which is not preferable for image quality.
The glossiness can be measured based on JIS Z 8741.

The toner image forming surface of the electrophotographic image receiving paper of the present invention preferably has high smoothness. As the smoothness, the arithmetic mean surface roughness (Ra) is preferably 2 μm or less, more preferably 1 μm or less, further preferably 0.5 μm or less in the entire region from white without toner to black with maximum density. is there. Arithmetic mean surface roughness is JI
It can be measured based on S B 0601, B 0651, B 0652.

The toner image forming surface of the electrophotographic image-receiving paper of the present invention has a reflectance of 80% or more, preferably 100% or more, for light in the wavelength range of 450 to 700 nm, and the maximum reflection for light in the wavelength range. The difference between the reflectance and the minimum reflectance is preferably 5% or less. In this case, wavelength 40
An electrophotographic image-receiving paper having a high reflectance in the vicinity of 0 to 450 nm emits strong fluorescence and is therefore preferable. The reflectance can be measured by Hitachi Color Analyzer C-2000.

The toner image-receiving layer used in the present invention contains various antioxidants, antioxidants, deterioration inhibitors, and ozone deterioration in order to improve the stability of the output image and the stability of the image-receiving layer itself. You may mix | blend an inhibitor, a ultraviolet absorber, a light stabilizer, a preservative, an antifungal agent, etc. Examples of the antioxidant include a chroman compound, a coumaran compound, a phenol compound (eg, hindered phenol), a hydroquinone derivative, a hindered amine derivative, and a spiroindane compound. Further, as an antioxidant, JP-A-61-61
Various antioxidants described in JP-A-159644 can be used. As the antiaging agent, for example, "Handbook Rubber / Plastic Compounding Chemicals Revision 2nd Edition" (1993, Rubber Digest Co.) p76-1
21 are mentioned.

Examples of the ultraviolet absorber include benzotriazole compounds (described in US Pat. No. 3,533,794) and 4-thiazolidone compounds (US Pat. No. 33526).
No. 81), a benzophenone compound (JP-A No. 4
6-2784) and an ultraviolet absorbing polymer (described in JP-A-62-260152). Examples of the metal complex include, for example, U.S. Pat.
No. 63-199248, JP-A-1-75568.
Nos. 1-74272 and 1-74272. In addition, "Handbook Rubber / Plastic Compounds Revision 2nd Edition" (1993, Rubber Digest) p122
The ultraviolet absorbers and light stabilizers described in 1 to 137 are also preferably used.

Further, in the toner image-receiving layer used in the present invention, various known photographic additives can be used. For example, as photographic additives, Research Disclosure (hereinafter abbreviated as RD) No. 1
7643 (December 1978), the same No. 18716
(November 1979) and the same No. 307105 (19
(November 1989), and the relevant parts are summarized below. Types of additives RD17643 RD18716 RD30710 1. Brightener 24 pages 648 pages right column 868 pages 2. Stabilizer page 24-25 page 649 page right column 868-870 page 3. Light absorber page 25-26 page 649 page right column page 873 UV absorber 4. Dye image stabilizer page 25 page 650 page right column 872 page 5. Hardener 26 pages 651 pages left column 874-875 pages 6. Binder page 26 page 651 page left column 873 to 874 page 7. Plasticizer / lubricant Page 27 Page 650 Page right column 876 Page 8. Coating aids Pages 26-27 Pages 650 Right column Pages 875-876 Surfactants 9. Antistatic agent page 27 page 650 page right column pages 876-877 pages

<Protective Layer> The electrophotographic image-receiving paper of the present invention has a surface protection, an improved storage stability, an improved handling property, a writing property, an improved device passage property, an anti-offset property, etc. For the purpose, a protective layer may be provided on the surface of the toner image receiving layer. The protective layer may be one layer or may be composed of two or more layers. Various thermoplastic resins, thermosetting resins and the like can be used as the binder in the protective layer. Preferably, the same kind as the toner image receiving layer is used. However, thermodynamic characteristics, electrostatic characteristics, etc.
It need not be the same as the toner image-receiving layer and can be optimized for each.

The protective layer may contain various additives as described above which can be used in the toner image-receiving layer. In particular, the protective layer may contain, for example, a plasticizer, a release agent, a slip agent, or the like. The outermost surface layer of the electrophotographic image-receiving paper of the present invention (for example, a surface protective layer when a surface protective layer is used) preferably has good compatibility with the toner from the viewpoint of fixability. . Specifically, the contact angle with the molten toner is preferably 0 to 40 degrees, for example.

<Back Layer> In the present invention, the back side of the base paper is provided with the back side output suitability, the back side output image quality is improved, the curl balance is improved, and the device passing property is improved. For the purpose of, a back layer can be provided. Further, in order to improve the double-sided output suitability for forming an image on the back surface of the base paper, the constitution of the back layer may be the same as that of the toner image receiving layer side. For the back layer, various additives described in relation to the toner image receiving layer can be used. As such an additive, it is appropriate to blend a charge control agent or the like. The back layer may be composed of one layer, or may be composed of two or more layers. Further, in order to prevent offset at the time of fixing, when a releasing oil is used for the fixing roller or the like, the back layer may have oil absorbability.

<Color Electrophotographic Toner> The electrophotographic image receiving paper of the present invention is used in combination with toner or toner particles during printing or copying. The toner used in the present invention can be obtained by either a pulverization method toner or a suspension granulation method toner. The pulverized toner is manufactured by kneading, pulverizing and classifying. The binder resin used in the production of the pulverized toner is, for example, an acid such as acrylic acid, methacrylic acid or maleic acid and its esters; polyester; polysulfonate; polyether; The obtained resin or a resin obtained by copolymerizing two or more kinds of those monomers can be used. These resins, including the wax component, are sufficiently kneaded together with other toner constituent materials with a heat kneader such as a heat roll, a kneader, an extruder, and then mechanically pulverized and classified. The toner obtained by such a pulverization method contains the wax component in an amount of 0.1 to 10% by mass, preferably 0.5 to 7 based on the mass of the toner.
It is suitable to contain it in the range of mass%.

In the case of the toner using the suspension granulation method, the binder, the colorant, and the release agent (as required, magnetic material, charge control agent and other additives) are mixed in a solvent that is incompatible with water. The obtained composition is coated with a polymer having a carboxyl group and then dispersed in an aqueous medium in the presence of a hydrophilic inorganic dispersant having a BET specific surface area of 10 to 50 m ² / g and / or a viscosity modifier. If necessary, the obtained suspension is diluted with an aqueous medium, and then the obtained suspension is heated and / or decompressed to remove the solvent, thereby producing a toner. In the present invention, it is particularly preferable to use the toner prepared by the suspension granulation method, and it may be possible to obtain more preferable results than the pulverized toner.

The binder used in the toner of the suspension granulation method is
All known binder resins can be used. Specifically, styrene, styrenes such as chlorostyrene, ethylene, propylene, butylene, monoolefins such as isoprene, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl esters such as vinyl butyrate, methyl acrylate, Α-Methylene aliphatic monocarboxylic acid esters such as ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate, vinyl methyl Examples thereof include homopolymers and copolymers of vinyl ethers such as ether, vinyl ethyl ether and vinyl butyl ether, and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone. Particularly representative binder resins include polystyrene resins, polyester resins, styrene-alkyl acrylate copolymers, styrene-alkyl methacrylate copolymers,
Styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer,
Examples thereof include polyethylene resin and polypropylene resin. Furthermore, polyurethane resins, epoxy resins, silicone resins, polyamide resins, modified rosins, paraffins, waxes and the like can be mentioned. Among these resins, styrene-acrylic resin is particularly preferable for the present invention.

As the colorant contained in the toner binder, any known colorant can be used. For example, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow,
Methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, C.I. I. Pigment Red 48: 1, C.I.
I. Pigment Red 122, C.I. I. Pigment
Red 57: 1, C.I. I. Pigment Yellow 97,
C. I. Pigment Yellow 12, C.I. I. Pigment Yellow 17, C.I. I. Pigment Blue 15:
1, C.I. I. Pigment Blue 15: 3 can be illustrated as a typical example. The content of the colorant is, for example, 2 to 8% by mass, preferably 4 to 6% by mass. When the content of the colorant is less than 2% by mass, the coloring power is weakened, and when it is more than 8% by mass, the transparency of the color toner is deteriorated.

It is preferable that the toner contains a release agent. As the release agent, for example, wax is preferably used, and specifically, low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicone resin softened by heating, oleic acid amide, erucic acid amide, ricinoleic acid amide, Fatty acid amides of stearic acid amide; plant waxes such as carnauba wax, rice wax, candelilla wax, wax and jojoba oil; animal waxes such as beeswax;
Mineral / petroleum waxes such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, and Fischer-Tropsch wax, and modified products thereof can be used. When a wax containing a wax ester having a large polarity such as carnauba wax or candelilla wax is used as these release agents, the exposed amount of the wax on the surface of the toner particles is large, and conversely, the polyethylene wax is used. In addition, waxes having a small polarity such as paraffin wax tend to reduce the amount of exposure to the surface.

Regardless of the tendency of exposure to the surface, the wax preferably has a melting point in the range of 30 to 150 ° C, more preferably 40 to 140 ° C. The toner used in the present invention is mainly composed of the colorant and the binder, and has an average particle size of 3 to 15.
Those having a thickness of μm, particularly 4 to 8 μm are preferably used. The storage elastic modulus G ′ of the toner itself at 150 ° C. (measured at an angular frequency of 10 rad / sec) is 10 to
It is preferably in the range of 200 Pa. An external additive may be added to the toner of the present invention. As the external additive, an inorganic compound fine powder and an organic compound fine particle are used. The inorganic compound fine particles include SiO ₂ , TiO ₂ , and Al.
₂ O ₃ , CuO, ZnO, SnO ₂ , Fe ₂ O ₃ , Mg
O, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , C
aO.SiO ₂ , K ₂ O. (TiO ₂ ) n, Al ₂ O _{3
· 2SiO 2, CaCO 3, MgCO} 3, BaSO 4,
It can be exemplified MgSO ₄ and the like. Further, as the organic compound fine particles, it is possible to use fine powders of fatty acids or derivatives thereof, metal powders of these or the like, and resin fine powders of fluorine-based resins, polyethylene resins, acrylic resins or the like.

<Image Forming Apparatus and Method> The method for forming an image on the electrophotographic image receiving paper of the present invention is not particularly limited. It can be applied to various electrophotographic methods. For example, a color image can be preferably formed on the electrophotographic image-receiving paper of the present invention. The formation of a color image can be performed using an electrophotographic apparatus capable of forming a full color image. An ordinary electrophotographic apparatus has an image receiving paper transport section, a latent image forming section, and a developing section arranged in proximity to the latent image forming section. Depending on the model, the latent image forming section may be formed in the center of the apparatus main body. The toner image intermediate transfer portion is provided in the vicinity of the image forming portion and the image receiving paper conveying portion.

Further, as a method for improving the image quality, an adhesive transfer method or a heat assisted transfer method is known in place of or in combination with electrostatic transfer or bias roller transfer. For example, JP-A-63-113576,
Japanese Unexamined Patent Publication No. 5-341666 discloses its specific structure. In particular, the method using the intermediate transfer belt of the heat assisted transfer system is preferable when the toner having a small particle size (7 μm or less) is used. As the intermediate belt, for example, an endless belt formed of electroformed nickel, which has a silicone or fluorine thin film on the surface and is provided with a peeling property is used. Further, it is preferable to provide a cooling device on the intermediate belt after or after the toner transfer onto the electrophotographic image receiving paper. By the cooling device, the toner is cooled to the softening temperature or the glass transition temperature of the binder used for the toner or less, efficiently transferred to the electrophotographic image-receiving paper, and peelable from the intermediate belt.

Fixing is an important step that affects the gloss and smoothness of the final image. Known fixing methods include fixing with a heating and pressing roller and belt fixing using a belt. From the viewpoint of image quality such as gloss and smoothness, the belt fixing method is preferable. Regarding the belt fixing method, for example, an oilless type belt fixing method described in JP-A-11-352819 and JP-A-11-23167 are disclosed.
No. 1 and JP-A-5-341666, there are known methods for achieving secondary transfer and fixing at the same time. The surface of the fixing belt is preferably surface-treated with a silicone-based material, a fluorine-based material, or a combination thereof in order to prevent toner peeling or offset of toner components. Further, it is preferable that a belt cooling device is provided in the latter half of fixing so that the electrophotographic image-receiving paper can be peeled off favorably. The cooling temperature is preferably a softening point or lower than the glass transition point of the toner binder and / or the polymer of the toner image-receiving layer of the electrophotographic image-receiving paper. On the other hand, in the initial stage of fixing, it is necessary to raise the temperature to a temperature at which the toner image-receiving layer of the electrophotographic image-receiving paper or the toner is sufficiently softened. Specifically, the cooling temperature is practically preferably 70 ° C. or lower and 30 ° C. or higher, and 180 ° C. or lower and 100 ° C. or higher in the initial fixing stage.

[0080]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but these examples and comparative examples do not limit the scope of the present invention. In addition,
In the following examples and comparative examples, "%" and "part"
Represents “mass%” and “parts by mass”, respectively.

(Example 1) <Preparation of base paper> Hardwood bleached kraft pulp (LBKP) was beaten with a disc refiner to 300 cc (Canadian standard freeness, CFS) to a fiber length of 0.58 mm. It was adjusted. Additives were added to this pulp stock at the following proportions based on the mass of pulp. Type of additive Amount (%) Cationic starch 1.2 Alkyl ketene dimer (AKD) 0.5 Anionic polyacrylamide 0.3 Epoxidized fatty acid amide (EFA) 0.2 Polyamide polyamine epichlorohydrin 0.3 Note) AKD is alkyl Ketene dimer means that the alkyl part is derived from a fatty acid mainly composed of behenic acid, and EFA is an epoxidized fatty acid amide (the fatty acid part is derived from a fatty acid mainly composed of behenic acid). means.

A base paper having a basis weight of 150 g / m ² was prepared from the obtained pulp stock with a Fourdrinier paper machine. In addition, in the middle of the drying zone of the Fourdrinier paper machine, PV
The _{^{A1.0g / cm 2, CaCl 2 0.8g}} / cm 2 was adhered. At the end of the papermaking process, the density was adjusted to 1.01 g / cm ³ using a soft calendar. In the obtained base paper, paper was passed through so that the metal roll was in contact with the side on which the toner image receiving layer was provided, and the surface temperature of the metal roll was 140 ° C. The Oken type smoothness of the obtained base paper is
265 seconds and Stoeckigt sizing degree was 127 seconds.

<Preparation of Coating Liquid for Toner Image Receiving Layer> (Titanium dioxide dispersion liquid) The following components were mixed and dispersed using NBK-2 manufactured by Nippon Seiki Seisaku-sho, Ltd. to prepare a titanium dioxide dispersion liquid (40 mass% of titanium dioxide pigment). %) Was prepared. Titanium dioxide (Taipaque (registered trademark) A-220, manufactured by Ishihara Sangyo) 40.0 g PVA102 2.0 g Ion-exchanged water 58.0 g

(Coating Liquid for Toner Image Receiving Layer) The following components were mixed and stirred to prepare a coating liquid for toner image receiving layer. Titanium dioxide dispersion 15.5 g Carnauba wax dispersion (Cerosol 524, Chukyo Yushi Co., Ltd.) 15.0 g Polyester resin water dispersion (solid content 30%, KZA-7049, Unitika) 100.0 g Thickener (ALCOX) E30, manufactured by Meisei Chemical Co., Ltd.) 2.0 g Anion surfactant (AOT) 0.5 g Ion-exchanged water 80 ml The viscosity of the obtained toner image-receiving layer coating liquid is 40 mPa.
s, and the surface tension was 34 mN / m.

<Preparation of Back Layer Coating Liquid> The following components were mixed and stirred to prepare a back layer coating liquid. Acrylic resin water dispersion (solid content 30%, Hyros XBH-997L, manufactured by Hoshiko Kagaku) 100.0 g Matting agent (Techpomer MBX-12, manufactured by Sekisui Plastics) 5.0 g Release agent (Hydrin D337, Chukyo Yushi) ) 10.0 g thickener (CMC) 2.0 g anionic surfactant (AOT) 0.5 g ion-exchanged water 80 ml The viscosity of the coating liquid for the back layer is 35 mPa · s,
The surface tension was 33 mN / m.

<Coating of Back Layer and Toner Image Receiving Layer> On the back surface of the obtained base paper, the above coating solution for back layer is applied by a bar coater, and then on the surface of the base paper, for the above toner image receiving layer. The coating liquid of was applied with a bar coater as in the case of the back layer. The coating amount of the back layer was 9 g / m ² in dry mass, and the coating amount of the toner image receiving layer was 12 g in dry weight. After coating, the back layer and the toner image-receiving layer were dried with hot air online. For drying, the amount of drying air and the temperature were adjusted so that both the back surface and the toner image receiving surface were dried within 2 minutes after application. The drying point was the point at which the coating surface temperature was the same as the wet-bulb temperature of the drying air. After drying, calendering was performed. For calendering, use a gloss calender and use a metal roller at 40
Pressure kept at 147 N / cm (15 kgf
/ Cm).

<Evaluation> The obtained electrophotographic image-receiving paper was
It was cut into 4 and used as a print image. The printer used was a Fuji Xerox color laser printer (DocuC), except that the fixing belt system shown in FIG. 1 was used.
color 1250-PF) was used. That is, in the fixing belt system 1 shown in FIG. 1, the fixing belt 2 is suspended over the heating roller 3 and the tension roller 5, and above the tension roller 5 via the fixing belt 2,
A cleaning roller 6 is provided, and further, a heating roller 3
A pressure roller 4 is provided below the fixing belt 2 via the fixing belt 2. The electrophotographic image receiving paper having the toner latent image is inserted from the right side between the heating roller 3 and the pressure roller 4 in FIG. It is cleaned by the roller 6. In this fixing belt system, the conveyance speed of the fixing belt 2 is 30 mm / sec, and the nip pressure between the heating roller 3 and the pressure roller 4 is 0.2 MPa (2 kgf).
/ Cm ² ) and the set temperature of the heating roller 3 is 150
C., which corresponds to the fixing temperature. The set temperature of the pressure roller 4 was set to 120 ° C.

<Image Quality> The electrophotographic image receiving paper was cut into A4 size, and the portrait image of a woman was used for evaluation according to the following evaluation criteria. A: Best B: Good, usable (within allowable range) C: Poor, unusable (not practically usable) D: Remarkably inferior, unusable <Glossiness> Visual observation of electrophotographic image-receiving paper after printing Observe at. The best gloss is ranked A, then B, C, D. Evaluation criteria A: Best B: Good, usable (within allowable range) C: Inferior, unusable (not practically usable) D: Remarkably inferior, unusable <Glossiness> of toner image forming surface of electrophotographic image-receiving paper JI
It was measured based on S Z 8741. <Average Surface Roughness> The average surface roughness (Ra) of the toner image forming surface of the electrophotographic image-receiving paper is defined by JIS B0601 and B0.
651, B 0652. The ^<L * ^a * ^{b *} values> of toner image formation surface of the electrophotographic image-receiving sheet ^L * ^a * ^{b *} values were measured in accordance with JIS Z 8730. <Reflectance> The reflectance (%) of light having a wavelength range of 450 to 700 nm on the toner image forming surface of the electrophotographic image receiving paper was measured.

(Examples 2 to 6 and Comparative Examples 1 to 3) Table 1,
As shown in 2, change the fiber length of the pulp used for the base paper, the sizing agent used for the surface treatment of the base paper, the calendering conditions, the density of the base paper, etc. The electrophotographic image-receiving paper obtained when the degree was changed was prepared, and the image quality, glossiness, glossiness, average surface roughness, L ^* a ^* b ^* value, and reflectance were measured in the same manner as in Example 1. evaluated. The results are shown in Table 2 below.

[0090]

[Table 1] In Table 1, AKD means alkyl ketene dimer and EFA means epoxidized fatty acid amide.

[0091]

[Table 2]

As can be seen from the results of Table 2, in Examples 1 to 6 according to the present invention, by using as the base paper, the smoothness of Oken type of 210 seconds or more and the Steckigt size degree of 100 seconds or more were used. It was confirmed that the obtained electrophotographic image-receiving paper had excellent image quality and glossiness as compared with Comparative Examples 1 to 3. As the base paper, the conditions of Oken type smoothness of 210 seconds or more and Steckigt's size degree of 100 seconds or more are satisfied, and further, the glossiness of the toner image forming surface is 20 or more, the average surface roughness is 2 μm or less, L ^* a 8 in ^* b ^* space
0 <L ^* , -2 <a ^* <2, -10 <b ^* <2, the reflectance for light in the wavelength range of 450 to 700 nm is 80% or more, and the maximum reflectance and the minimum for light in the wavelength range. Examples 1 to 6 satisfying the condition that the difference from the reflectance is 5% or less
Have been found to have even better image quality and gloss.

[0093]

According to the present invention, it is possible to provide an electrophotographic image receiving paper which can be manufactured more easily than the conventional electrophotographic image receiving paper and which is excellent in toner image and gloss obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a fixing belt system in a printer used in an example.

[Explanation of symbols]

1 fixing belt system 2 fixing belt 3 heating roller 4 pressure roller 5 Tension roller 6 cleaning roller

Continued front page    (72) Inventor Yasuhiro Ogata             200, Onakazato, Fujinomiya City, Shizuoka Prefecture Fuji Photo             Within Film Co., Ltd. (72) Inventor Yoshisada Nakamura             200, Onakazato, Fujinomiya City, Shizuoka Prefecture Fuji Photo             Within Film Co., Ltd. (72) Inventor Asahi Murai             200, Onakazato, Fujinomiya City, Shizuoka Prefecture Fuji Photo             Within Film Co., Ltd.

Claims (9)

[Claims] 1. An electrophotographic image-receiving paper comprising a base paper and a toner image-receiving layer provided on at least one surface of the base paper, wherein the surface of the base paper on the toner image-receiving layer side is a Oken-type smooth surface. Degree is 210 seconds or more and Steckigt size degree is 1
40 seconds or more, and the toner image-receiving layer is 40 times based on the mass of the thermoplastic resin forming the toner image-receiving layer.
An electrophotographic image-receiving paper comprising a pigment in an amount of less than mass%. 2. The electrophotographic image receiving paper according to claim 1, wherein the Oken smoothness is 250 seconds or more. 3. The electrophotographic image receiving paper according to claim 1, wherein the Steckigt sizing degree is 150 seconds or more. 4. The image receiving paper for electrophotography according to claim 1, wherein the pigment is less than 30% by mass. 5. The electrophotographic image receiving sheet according to claim 1, wherein the toner image forming surface of the electrophotographic image receiving sheet has a glossiness of 20 or more. 6. The electrophotographic image receiving sheet according to claim 1, wherein the toner image forming surface of the electrophotographic image receiving sheet has an average surface roughness of 2 μm or less. 7. The toner image forming surface of the electrophotographic image receiving paper has an L ^* a ^* b ^* space of 80 <L ^* , -2 <a.
7. The electrophotographic image receiving paper according to claim 1, wherein the conditions of ^* <2 and −10 <b ^* <2 are satisfied. 8. The toner image forming surface of the electrophotographic image receiving paper has a reflectance of 80% or more for light in the wavelength range of 450 to 700 nm, and has a maximum reflectance and a minimum reflectance of light in the wavelength range. The electrophotographic image receiving paper according to claim 1, wherein the difference is 5% or less. 9. An image forming method using the electrophotographic image receiving sheet according to claim 1, wherein a toner image is formed on the electrophotographic image receiving sheet, and then the electrophotographic image receiving sheet is formed. An image forming method characterized in that the image forming surface of the image receiving paper is heated and pressed by a fixing belt.