JP4409352B2 - Electrophotographic image receiving sheet and image forming method - Google Patents

Description

  The present invention relates to a high-quality electrophotographic image-receiving sheet that has good image quality and excellent printer running performance, and an image forming method using the electrophotographic image-receiving sheet.

  Conventionally, a resin-coated support (double-sided polyolefin resin-coated paper) used for silver-salt photographic prints has been used as a support for electrophotographic image-receiving sheets in order to achieve high-quality images of silver-salt photographic-like in electrophotography It is used. As a result, an electrophotographic image-receiving sheet having high smoothness, glossiness and flatness and excellent in image quality and handling is obtained (see Patent Documents 1 to 3, etc.).

  On the other hand, electrophotographic image-receiving sheets are required to have a stable running property that does not cause a running failure such as jamming and multi-feed conveyance as the device becomes smaller and faster. For this reason, various electrophotographic image-receiving sheets provided with an antistatic layer or improved in surface smoothness, rigidity, curling properties and the like have been proposed (see Patent Documents 1 to 5).

  However, none of the conventional electrophotographic image-receiving sheets have both image quality and good runnability, and an electrophotographic image-receiving sheet having sufficiently satisfactory performance has not yet been obtained. .

Japanese Patent Laid-Open No. 8-21645 JP 2000-10325 A JP 2000-10327 A JP 2001-138626 A JP 2001-228646 A

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention provides a high-quality electrophotographic image-receiving sheet having good image quality, stable running properties such as jamming and multi-feed conveyance, and image formation using the electrophotographic image-receiving sheet. It aims to provide a method.

Means for solving the problems are as follows. That is,
<1> In an electrophotographic image-receiving sheet having a support and at least one toner image-receiving layer on the support, the support is provided with a polyolefin resin layer on both sides of the base paper, and the base paper on the support Contains at least one of an alkali metal salt and an alkaline earth metal salt in an amount of 0.6 to 3 g / m ² , and the water content in the base paper in the electrophotographic image-receiving sheet is 6.5 to 8.5% . This is an electrophotographic image-receiving sheet.
< 2 > At least one of an alkali metal salt and an alkaline earth metal salt is selected from an alkali metal chloride, carbonate and sulfate, and an alkaline earth metal chloride, carbonate and sulfate. The electrophotographic image-receiving sheet according to < 1 >, which is a seed.
< 3 > The electrophotographic image-receiving sheet according to any one of <1> to < 2 >, wherein the base paper contains 0.5 to ² g / m ^{2 of} a water-soluble polymer compound.
< 4 > For electrophotography according to < 3 >, wherein the water-soluble polymer compound is at least one selected from polyvinyl alcohol, carboxy-modified polyvinyl alcohol, carboxymethylcellulose, hydroxyethylcellulose, cellulose sulfate, polyethylene oxide and gelatin. It is an image receiving sheet.
< 5 > From the above <1> obtained by subjecting the base paper to surface sizing with a surface sizing solution containing at least one of an alkali metal salt and an alkaline earth metal salt and a water-soluble polymer compound, and then calendering 4 > The electrophotographic image-receiving sheet according to any one of 4 >.
< 6 > The electrophotographic image-receiving sheet according to < 5 >, wherein the calendar treatment is performed using a soft calender having a metal roll having a surface temperature of 150 ° C. or higher.
< 7 > The electrophotographic image-receiving sheet according to any one of <1> to < 6 >, wherein the base paper contains at least one of an alkyl ketene dimer and an epoxidized fatty acid amide as a sizing agent.
< 8 > The electrophotographic image-receiving sheet according to any one of <1> to < 7 >, wherein the base paper contains a pulp stock having a weight average fiber length of 0.45 to 0.70 mm.
< 9 > A toner image forming step for forming a toner image on the electrophotographic image-receiving sheet according to any one of <1> to < 8 >, and a surface of the toner image formed by the toner image forming step And an image surface smoothing and fixing step.
< 10 > In the image surface smoothing and fixing step, the toner image is heated and pressed using an image surface smoothing and fixing processor having a heating and pressing member, a belt member, and a cooling device, cooled, and peeled off. 9 >. The image forming method according to 9 >.
< 11 > The image forming method according to any one of < 9 > to < 10 >, wherein the surface of the belt member has a fluorocarbonsiloxane rubber layer.
< 12 > The image forming method according to any one of < 9 > to < 10 >, wherein the surface of the belt member has a layer made of silicone rubber, and the surface of the silicone rubber layer has a layer made of fluorocarbonsiloxane rubber. It is.
< 13 > The image forming method according to any one of < 11 > to < 12 >, wherein the fluorocarbon siloxane rubber has at least one of a perfluoroalkyl ether group and a perfluoroalkyl group in a main chain.

The electrophotographic image-receiving sheet of the present invention has a support and at least one toner image-receiving layer on the support, the support is provided with a polyolefin resin layer on both sides of the base paper, and the support. The base paper contains at least one of an alkali metal salt and an alkaline earth metal salt in an amount exceeding 0.5 g / m ² , and the water content in the base paper in the electrophotographic image-receiving sheet is 6.5% or more. As a result, it is possible to provide a high-quality electrophotographic image-receiving sheet having good image quality and stable running performance that does not cause running failures such as jamming and multi-feed conveyance.

  The image forming method of the present invention comprises a toner image forming step for forming a toner image on the electrophotographic image receiving sheet of the present invention, and an image surface smoothing and fixing for smoothing the surface of the toner image formed by the toner image forming step. Process. As a result, even if an oilless machine without fixing oil is used, stable paper feeding without being offset to the fixing roller and the fixing belt can be realized, and a high-quality image close to the quality of a silver salt photograph can be obtained.

  According to the present invention, it is possible to provide a high-quality electrophotographic image-receiving sheet that can solve conventional problems, has good image quality, and has stable running performance that does not cause running failures such as jamming and multi-feed conveyance.

(Electrophotographic image-receiving sheet)
The electrophotographic image-receiving sheet of the present invention has a support and at least one toner image-receiving layer on the support, and other layers appropriately selected as necessary, for example, a back layer, a surface protective layer, It comprises an intermediate layer, an undercoat layer, a cushion layer, a charge control (prevention) layer, a reflection layer, a tint preparation layer, a storage stability improving layer, an adhesion prevention layer, an anti-curl layer, a smoothing layer and the like. Each of these layers may have a single layer structure or a laminated structure.

In the electrophotographic image-receiving sheet, the support is provided with a polyolefin resin layer on both sides of a base paper, and the base paper in the support is at least one of an alkali metal salt and an alkaline earth metal salt at 0.5 g / m. ^{While the} content is more than ² , the water content in the base paper in the electrophotographic image-receiving sheet is 6.5% or more.

The at least one of the alkali metal salt and the alkaline earth metal salt is, for example, at least selected from alkali metal chloride, carbonate and sulfate, and alkaline earth metal chloride, carbonate and sulfate. One type is preferable, and examples thereof include CaCl ₂ , CaCO ₃ , NaCl, Na ₂ CO ₃ , KCl, Na ₂ SO ₄ , K ₂ SO ₄ , LiCl, and the like.
At least one of the content of alkali metal and alkaline earth metal salts of the base paper is an amount of more than ^{0.5g / m 2, 0.6~3g / m} 2 is preferred.
When the content is 0.5 g / m ² or less, poor runnability is likely to occur due to the occurrence of static.
In addition, it is preferable that at least one of the alkali metal salt and the alkaline earth metal salt in the base paper is attached to the base paper simultaneously with the water-soluble polymer compound by a surface sizing process described later.

In addition, the electrophotographic image-receiving sheet satisfies the content of at least one of the alkali metal salt and the alkaline earth metal salt in the base paper, and the water content in the base paper in the electrophotographic image-receiving sheet is 6. It is 5% or more, and 6.5 to 8.5% is preferable.
When the water content in the base paper is less than 6.5%, running failure tends to occur due to the occurrence of static.
Here, the moisture content in the base paper in the electrophotographic image-receiving sheet is, for example, peeled off at the interface between the polyethylene resin layer and the base paper on the front and back surfaces of the electrophotographic image-receiving sheet, and the obtained base paper is kept at 105 ° C. The dried portion before and after drying can be measured as the amount of water in the base paper.

[Support]
The support is provided with a polyolefin resin layer on both sides of the base paper, and further has other layers as necessary.

-Base paper-
The base paper is not particularly limited and may be appropriately selected depending on the intended purpose. Specifically, it is a high-quality paper, for example, “Photographic Engineering Basics—Silver Salt Photography” edited by the Japan Photography Society, Papers described on pages 223 to 224 of the company Corona (Showa 54) are preferred.

  The base paper is not particularly limited as long as it is a known material used for a support, and can be appropriately selected from various materials according to the purpose. For example, natural pulp such as conifers and hardwoods, Examples include a mixture of pulp and synthetic pulp.

The pulp that can be used as the raw material of the base paper is hardwood bleached kraft pulp (LBKP) from the viewpoint of improving the surface smoothness, rigidity and dimensional stability (curlability) of the base paper at the same time in a well-balanced and sufficient level. Although desirable, softwood bleached kraft pulp (NBKP), hardwood sulfite pulp (LBSP) and the like can also be used.
The pulp fiber preferably has a weight average fiber length of 0.45 to 0.70 mm.
A beater or refiner can be used for beating the pulp. In the pulp slurry obtained after beating the pulp (hereinafter sometimes referred to as “pulp stock”), various additives such as a filler, a dry paper strength enhancer, a sizing agent, and wet paper are used as necessary. A force enhancer, a fixing agent, a pH adjuster, other agents, etc. can be added.
The pulp whiteness specified in JIS P8123 in the pulp stock is preferably 88% or more, more preferably 90% or more.
When the pulp whiteness is less than 88%, yellowishness tends to be noticeable, and adjustment with a fluorescent whitening agent or a bluing agent may be difficult.

Examples of the filler include calcium carbonate, clay, kaolin, white clay, talc, titanium oxide, diatomaceous earth, barium sulfate, aluminum hydroxide, and magnesium hydroxide.
Examples of the dry paper strength enhancer include cationized starch, cationized polyacrylamide, anionized polyacrylamide, amphoteric polyacrylamide, and carboxy-modified polyvinyl alcohol.
Examples of the sizing agent include fatty acid salts, rosin derivatives such as rosin and maleated rosin, paraffin wax and the like, and further higher fatty acids such as alkyl ketene dimer, alkenyl succinic anhydride (ASA), and epoxidized fatty acid amide. And the like.
Examples of the wet paper strength enhancer include polyamine polyamide epichlorohydrin, melamine resin, urea resin, and epoxidized polyamide resin.
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 adjuster include caustic soda and sodium carbonate.
As said other chemical | medical agent, an antifoamer, dye, a slime control agent, a fluorescent whitening agent, etc. are mentioned, for example.
Furthermore, a softening agent etc. can also be added as needed. As the softening agent, for example, those described in New Handbook for Paper Processing (Edited by Paper Medicine Time), pages 554 to 555 (issued in 1980) can be used.
These various additives may be used alone or in combination of two or more. Moreover, there is no restriction | limiting in particular in the addition amount in these pulp paper materials, such as these various additives, It can select suitably according to the objective, Usually, 0.1-1.0 mass% is preferable.

If necessary, the pulp slurry may further include a paper machine such as a manual paper machine, a long paper machine, a round paper machine, a twin wire machine, or a combination machine. It is used to make paper and then dried to produce a base paper. Further, if desired, the surface sizing treatment can be performed either before or after the drying.
The surface sizing solution used for the surface sizing treatment is, for example, a metal salt of at least one of an alkali metal salt and an alkaline earth metal salt, a water-soluble polymer compound, a fluorescent brightener, a water-resistant substance, a pigment, Contains dyes, etc.
As the metal salt of at least one of the alkali metal salt and the alkaline earth metal salt, those described above can be used.

The water-soluble polymer compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, cellulose sulfate, polyethylene oxide, gelatin, cation Starch, casein, sodium polyacrylate, styrene-maleic anhydride copolymer sodium salt, sodium polystyrene sulfonate, etc., among these, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, carboxymethylcellulose, hydroxyethylcellulose, cellulose Sulfate, polyethylene oxide, and gelatin are preferable, and polyvinyl alcohol (PVA) is more preferable.
In addition, the content of the water-soluble polymer compound is preferably 0.5 to ² g / m ² .

Examples of the fluorescent brightener include stilbene compounds, coumarin compounds, biphenyl compounds, benzoxazoline compounds, naphthalimide compounds, pyrazoline compounds, carbostyril compounds, diaminostilbene disulfonic acid derivatives, imidazole derivatives, Examples include coumarin derivatives, triazole derivatives, carbazole derivatives, pyridine derivatives, naphthalic acid derivatives, imidazolone derivatives, and the like. Among these, stilbene compounds are preferable.
The content of the fluorescent brightener in the base paper is not particularly limited, but is preferably 0.01 to 0.5% by mass, and more preferably 0.02 to 0.2% by mass.
Examples of the water-resistant substance include latex emulsions such as styrene-butadiene copolymer, ethylene-vinyl acetate copolymer, polyethylene, vinylidene chloride copolymer; polyamide polyamine epichlorohydrin, and the like.
Examples of the pigment include calcium carbonate, clay, kaolin, talc, barium sulfate, and titanium oxide.

  The base paper has a longitudinal Young's modulus (Ea) and a transverse Young's modulus (Eb) ratio (Ea / Eb) of 1.5 to 2.0 in terms of improving rigidity and dimensional stability (curling property). It is preferable that it exists in the range. In the range where the Ea / Eb value is less than 1.5 or more than 2.0, the rigidity and curl property of the electrophotographic image-receiving sheet are liable to be deteriorated, and the running property during conveyance is hindered. Absent.

The Oken type smoothness of the surface of the base paper on the toner image-receiving layer side is preferably 210 seconds or more, and more preferably 250 seconds or more. If the Oken smoothness is less than 210 seconds, the image quality of the toner image becomes poor, which is not preferable. In addition, although an upper limit is not specifically limited, In practice, about 600 seconds are preferable and about 500 seconds are more preferable.
Here, the Oken-type smoothness is measured according to JAPAN TAPPI No. 5 Smoothness defined by the B method.

In general, it is known that the “strain” of paper differs based on the difference in the beating style. Can be used as an additional factor. In particular, the elastic modulus of paper is measured by measuring the speed of sound propagating through the paper, using the relationship between the dynamic elastic modulus and density, which indicates the physical properties of the viscoelastic material of the paper, and using an ultrasonic vibration element. Can be obtained from the following equation.
E = ρc ² (1-n ² )
However, in the above formula, E means dynamic elastic modulus. ρ means density. c means the speed of sound in the paper. n means Poisson's ratio.

In the case of normal paper, since n = about 0.2, even if it is calculated by the following formula, it can be calculated without much difference.
E = ρc ²
That is, if the density and sound speed of paper can be measured, the elastic modulus can be easily obtained. In the above equation, when measuring the speed of sound, various known devices such as Sonic Tester SST-110 (manufactured by Nomura Corporation) can be used.

There is no restriction | limiting in particular in the thickness of the said base paper, Although it can select suitably according to the objective, Usually, 30-500 micrometers is preferable, 50-300 micrometers is more preferable, 100-250 micrometers is still more preferable. The basis weight of the raw paper is not particularly limited and may be appropriately selected depending on the intended purpose, for example, preferably ^{50~250g / m 2, 100~200g / m} 2 is more preferable.

-Polyolefin resin layer-
As the polyolefin resin layer, for example, a polyolefin resin such as a homopolymer of α-olefin such as polyethylene and polypropylene and a mixture thereof is used. These polyolefin resins are not particularly limited in molecular weight as long as extrusion coating is possible, and can be appropriately selected according to the purpose. Usually, polyolefin resins having a molecular weight of 20,000 to 200,000 are used. Used.

  As the polyolefin resin layer, for example, a polyolefin resin such as a homopolymer of α-olefin such as polyethylene and polypropylene or a mixture thereof is used. These polyolefin resins are not particularly limited in molecular weight as long as extrusion coating is possible, and can be appropriately selected according to the purpose. Usually, polyolefin resins having a molecular weight in the range of 20,000 to 200,000 are used. Used.

There is no restriction | limiting in particular as said polyethylene resin, According to the objective, it can select suitably, For example, high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (L-LDPE), etc. Is mentioned.
For example, (1) The melt index is 5 to 30 g / 10 min, preferably 10 to 20 g / 10 min, and the density is high in that the cut surface when cut into a specified size with a cutter or the like in the cutting step is uniform and clean. 40-75 parts by mass of 0.945 g / cm ³ or more of high-density polyethylene, and (2) a melt index of 1-15 g / 10 min, preferably 2-10 g / 10 min, and a density of 0.930 g / cm ³ or less. It is preferable to use a polyethylene resin mixture obtained by mixing 25 to 60 parts by mass of low density polyethylene.
These resins may be used alone or in combination of two or more.

  The mixing ratio (HDPE / LDPE) of the high-density polyethylene and low-density polyethylene is preferably 40 to 75/60 to 25, more preferably 50 to 70/50 to 30 in terms of mass ratio. In the support having a polyolefin resin layer coated with a polyethylene mixture in which the high-density polyethylene is 75 parts by mass or more and the low-density polyethylene is less than 25 parts by mass, sufficient cutting characteristics (uniform cutting) Surface) may not be obtained. On the other hand, in a support having a polyolefin resin layer coated with a polyethylene mixture in which high-density polyethylene is less than 40 parts by mass and low-density polyethylene is 60 parts by mass or more, sufficient cutting characteristics (uniform cut surface) However, it is not preferable because the surface is partially melted by the heating roll at the time of fixing, causing a deterioration in surface properties or a jamming failure due to poor running.

  When a polyolefin resin layer is provided on both sides of the base paper, it is preferable to coat a polyolefin resin layer made of a polyethylene mixture having the above composition on both sides. Further, the polyolefin resin layer may contain an antistatic agent such as a surfactant or a metal oxide in order to adjust the surface electric resistance, and further serves as both a polyolefin resin layer containing these and a conductive layer. It may be used as a layer.

With respect to the polyolefin resin layer, from the viewpoint of improving the image quality, when the polyolefin resin layer is a single layer, at least one layer of the polyolefin resin layer is included in the polyolefin resin layer. An inorganic pigment such as titanium dioxide, a bluing agent, a fluorescent brightening agent, an antioxidant and the like may be contained therein, and it is particularly preferable to contain titanium dioxide.
Moreover, when this polyolefin resin layer is a multilayer, the tackifier resin, adhesive resin, etc. can also be contained in the lowest layer which contact | connects a base paper from a viewpoint of making adhesiveness with a base paper favorable. Further, if necessary, an antioxidant, a release agent, a hollow polymer and the like may be contained.

  When the titanium dioxide is contained in the polyolefin resin layer, the form of the titanium dioxide is not particularly limited, and may be anatase type or rutile type. The anatase type is preferable, and the rutile type is preferable when priority is given to sharpness. In consideration of both whiteness and sharpness, anatase type and rutile type may be blended and used. Further, two polyolefin resin layers containing titanium dioxide may be used, one layer containing anatase-type titanium dioxide, and the other layer containing rutile-type titanium dioxide.

  The average particle size of the titanium dioxide is preferably 0.1 to 0.4 μm, for example. When the average particle size is less than 0.1 μm, it becomes difficult to uniformly mix and disperse in the polyolefin resin layer. When the average particle size exceeds 0.4 μm, sufficient whiteness cannot be obtained, and the surface of the polyolefin resin layer is not obtained. Protrusions may occur and adversely affect image quality.

  The titanium dioxide preferably has a particle surface treated with a silane coupling agent, and the silane coupling agent preferably has an end modified with ethoxy or methoxy. The treatment amount of the silane coupling agent is preferably 0.05 to 2.5% by mass, more preferably 0.5 to 2.0% by mass with respect to titanium dioxide. When the treatment amount of the silane coupling agent is less than 0.05% by mass, the surface treatment effect by the silane coupling agent may not be sufficient, and when it exceeds 2.5% by mass, the titanium dioxide is excessively treated. May be.

In order to suppress the activity of the titanium dioxide pigment, the surface of the titanium dioxide is preferably subjected to a surface treatment with an inorganic surface treatment agent before the surface treatment of the silane coupling agent. The inorganic surface treatment agent is preferably, for example, at least one of Al ₂ O ₃ and SiO ₂ , and the treatment amount (calculated in the form of an anhydride) of this inorganic surface treatment agent is not limited to titanium dioxide. On the other hand, 0.01-1.8 mass% is preferable and 0.2-1.0 mass% is more preferable.
If the surface of the titanium dioxide is not subjected to an inorganic surface treatment, the heat resistance of the titanium dioxide is low, and the titanium dioxide may turn yellow when used in an extrusion laminate at around 320 ° C. Moreover, since the activity of titanium dioxide is not suppressed, the titanium dioxide particles are aggregated and caught in a metal filter net equivalent to 20 to 400 mesh that is generally provided in order to prevent extrusion of foreign matter near the exit of the extrusion laminate. May cause an increase in pressure.
On the other hand, when the treatment amount of the inorganic surface treatment agent exceeds 1.8% by mass with respect to titanium dioxide, moisture easily adheres to the surface of the inorganic surface treatment agent, and when used for extrusion lamination, the growth of die lip stains is remarkably fast. May be.

  The titanium dioxide is kneaded using a metal salt of a higher fatty acid, a higher fatty acid ethyl, a higher fatty acid amide, a higher fatty acid, a polyolefin wax or the like as a dispersion aid, such as a two-roll, three-roll, kneader, Banbury mixer, continuous kneading, etc. And kneaded into the resin. As the dispersion aid, a metal stearate is preferable, and zinc stearate is more preferable. The resin thus kneaded with the titanium dioxide pigment is formed into a pellet shape and used as a master batch of the titanium dioxide pigment.

  The titanium dioxide concentration in the pellet is preferably about 30 to 75% by mass. The concentration of the dispersion aid in the pellet is preferably about 0.5 to 10% by mass. When the titanium dioxide concentration is less than 30% by mass, the bulk of the pellet increases. Conversely, when it exceeds 75% by mass, the dispersibility of the titanium dioxide is deteriorated and the pellet is liable to be cracked. Moreover, it is preferable to dry dry or vacuum dry the masterbatch containing titanium dioxide at 50-90 degreeC for 2 hours or more before use.

  As content of the said titanium dioxide in the said polyolefin resin layer, 5-50 mass% is preferable, and 8-45 mass% is more preferable. When the content is less than 5% by mass, the resolution may be inferior. On the other hand, when the content exceeds 50% by mass, die streaks may occur during production.

  Examples of the bluing agent include commonly known ultramarine blue, cobalt blue, cobalt oxide phosphate, quinacridone pigments, and the like, and mixtures thereof. The particle size of the bluing agent is not particularly limited and may be appropriately selected depending on the intended purpose, but is usually preferably in the range of 0.3 to 10 μm. In addition, when using a blueing agent for the uppermost layer of a polyolefin resin layer, it is preferable to contain 0.2-0.4 mass%. Moreover, when using for the lower layer side, it is preferable to make it contain 0-0.15 mass%.

  As content in the said polyolefin resin layer of the said antioxidant, about 50-1,000 ppm is preferable with respect to resin which forms the said polyolefin resin layer. The masterbatch containing the titanium dioxide pigment and the like thus produced is appropriately diluted with the resin forming the polyolefin resin layer and used for extrusion lamination.

  The tackifier resin is appropriately selected from rosin derivative resins, terpene resins (for example, polymer β-pinene), coumarone / indene resins, petroleum hydrocarbon resins, and the like. These may be used alone or in combination of two or more.

  Examples of the petroleum hydrocarbon resins include aliphatic petroleum resins, aromatic petroleum resins, dicyclopentadiene petroleum resins, copolymer petroleum resins, hydrogenated petroleum resins, alicyclic petroleum resins, and the like. Is mentioned. As the aliphatic petroleum resin, those having 5 carbon atoms are particularly preferable. As the aromatic petroleum resin, those having 9 carbon atoms are particularly preferable.

  As a compounding quantity of the said tackifier resin, 0.5-60 mass% is preferable normally with respect to resin which comprises the said polyolefin resin layer, and 10-35 mass% is more preferable. If the blending amount of the tackifier resin is less than 0.5% by mass, adhesion failure may occur. On the other hand, if it exceeds 60% by mass, neck-in during production may easily occur.

  Examples of the adhesive resin include ionomer, ethylene vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer, and metal salts thereof. As a compounding quantity of the said adhesive resin, 20-500 mass parts is preferable with respect to 100 mass parts of resin which forms the said polyolefin resin layer, and 50-200 mass parts is more preferable. The tackifier resin and the adhesive resin may be used in combination.

  The polyolefin resin layer is usually laminated on the base paper that has been melted by melting the pellets containing the titanium dioxide and the like that have been heated and melted, diluted with the resin that forms the polyolefin resin layer as necessary, and run. It is formed by coating by any of a method, a sequential laminating method, or a laminating method using a single block or multi-layer extrusion die such as a foot block type, a multi-manifold type, a multi-slot type, or a laminator. The shape of the single-layer or multi-layer extrusion die is not particularly limited and may be appropriately selected depending on the intended purpose. In general, a T die, a coat hanger die, and the like are preferable.

  In addition, before coating the resin for forming the polyolefin resin layer on one or both surfaces of the base paper, the base paper is subjected to activation treatment such as corona discharge treatment, flame treatment, glow discharge treatment, or plasma treatment. It is preferable.

The thickness of the polyolefin resin layer formed on the side (surface) of the support on which the toner image receiving layer is formed is preferably 10 to 60 μm. On the other hand, the thickness of the polyolefin resin layer formed on the side of the support on which the toner image-receiving layer is not formed (back surface) is preferably 10 to 50 μm.
The thickness of the support is preferably 35 to 510 μm, more preferably 55 to 310 μm, and still more preferably 105 to 260 μm. Various stiffnesses can be used according to the purpose, and the support for a photographic image receiving sheet for electrophotography is close to a support for color silver halide photography. Those are preferred.

[Toner image receiving layer]
The toner image receiving layer is a toner image receiving layer for receiving color toner or black toner and forming an image. The toner image receiving layer receives a toner for forming an image from a developing drum or an intermediate transfer body by (static) electricity, pressure, etc. in a transfer process, and fixes it by heat, pressure, etc. in a fixing process. Have

The toner image-receiving layer is preferably a low-transparency toner image-receiving layer having a light transmittance of 78% or less in terms of making the electrophotographic image-receiving sheet of the present invention feel close to a photograph, and the light transmittance is 73%. The following is more preferable, and 72% or less is still more preferable.
The light transmittance can be measured by separately forming a coating film having the same thickness on a polyethylene terephthalate film (100 μm) and using the direct reading haze meter (Suga Test Instruments HGM-2DP). .

  The toner image-receiving layer contains at least a thermoplastic resin, and various additives added for the purpose of improving the thermodynamic properties of the toner image-receiving layer, for example, a release agent, a plasticizer, a colorant, Contains a filler, a crosslinking agent, a charge control agent, an emulsifier, a dispersant and the like.

-Thermoplastic resin-
There is no restriction | limiting in particular as said thermoplastic resin, According to the objective, it can select suitably, (1) Polyolefin resin, (2) Polystyrene resin, (3) Acrylic resin, (4) Polyvinyl acetate Alternatively, derivatives thereof, (5) polyamide resin, (6) polyester resin, (7) polycarbonate resin, (8) polyether resin (or acetal resin), (9) other resins, and the like can be given. These may be used individually by 1 type and may use 2 or more types together. Among these, styrene resins, acrylic resins, and polyester resins having a large cohesive energy are particularly preferably used from the viewpoint of embedding toner.

Examples of the polyolefin-based resin (1) include polyolefin resins such as polyethylene and polypropylene, and copolymer resins of olefins such as ethylene and propylene and other vinyl monomers. Examples of the copolymer resin of the olefin and another vinyl monomer include an ethylene-vinyl acetate copolymer and an ionomer resin that is a copolymer of acrylic acid or methacrylic acid. Examples of the polyolefin resin derivative include chlorinated polyethylene and chlorosulfonated polyethylene.
Examples of the polystyrene-based resin (2) include polystyrene resin, styrene-isobutylene copolymer, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), and polystyrene-anhydrous. A maleic acid resin etc. are mentioned.
Examples of the acrylic resin (3) include polyacrylic acid or esters thereof, polymethacrylic acid or esters thereof, polyacrylonitrile, and polyacrylamide.
Examples of the esters of polyacrylic acid include homopolymers and multi-component copolymers of esters of acrylic acid. Examples of the ester of acrylic acid include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, 2-chloroethyl acrylate, And phenyl acrylate, methyl α-chloroacrylate, and the like.
Examples of the polymethacrylic acid esters include homopolymers and multi-component copolymers of methacrylic acid esters. Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, and butyl methacrylate.
Examples of the polyvinyl acetate or derivative thereof (4) include polyvinyl acetate, polyvinyl alcohol obtained by saponifying polyvinyl acetate, and polyvinyl alcohol as aldehyde (eg, formaldehyde, acetaldehyde, butyraldehyde, etc.). Examples thereof include polyvinyl acetal resins obtained by reaction.
The polyamide-based resin (5) is a polycondensate of diamine and dibasic acid, and examples thereof include 6-nylon and 6,6-nylon.
The polyester resin (6) is produced by condensation polymerization of an acid component and an alcohol component. The acid component is not particularly limited and may be appropriately selected depending on the intended purpose. For example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, terephthalic acid, isophthalic acid, succinic acid , Adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid , Isooctylsuccinic acid, trimellitic acid, pyromellitic acid, acid anhydrides thereof, or lower alkyl esters thereof.
There is no restriction | limiting in particular as said alcohol component, According to the objective, it can select suitably, For example, bivalent alcohol is preferable. Examples of the aliphatic diol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, , 5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like. Examples of the alkylene oxide adduct of bisphenol A include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (3.3) -2,2-bis. (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2, Examples thereof include 2-bis (4-hydroxyphenyl) propane and polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane.
The polycarbonate resin (7) is generally a polycarbonate obtained from bisphenol A and phosgene.
Examples of the polyether resin (or acetal resin) of (8) include polyether resins such as polyethylene oxide and polypropylene oxide, and acetal resins such as polyoxymethylene as a ring-opening polymerization system.
Examples of the other resin (9) include polyaddition polyurethane resins.

  The thermoplastic resin is preferably one that can satisfy the following properties of the toner image-receiving layer with the toner image-receiving layer formed, and more preferably one that can satisfy the properties of the toner-image-receiving layer described later even with the resin alone. It is also preferable to use two or more resins having different physical properties of the toner image-receiving layer in combination.

  As the thermoplastic resin, those having a larger molecular weight than the thermoplastic resin used in the toner are preferable. However, the molecular weight described above is not always preferable depending on the relationship between the thermodynamic characteristics of the thermoplastic resin used in the toner and the thermoplastic resin in the toner image receiving layer. For example, when the softening temperature of the thermoplastic resin in the toner image receiving layer is higher than the thermoplastic resin used in the toner, the molecular weight is the same or the thermoplastic resin in the toner image receiving layer is smaller. It may be preferable.

It is also preferable to use a mixture of resins having the same composition and different average molecular weights as the thermoplastic resin of the toner image-receiving layer. Further, as the relationship with the molecular weight of the thermoplastic resin used in the toner, the relationship disclosed in JP-A-8-334915 is preferable.
The molecular weight distribution of the thermoplastic resin in the toner image-receiving layer is preferably wider than the molecular weight distribution of the thermoplastic resin used in the toner.
As the thermoplastic resin of the toner image-receiving layer, JP-A-5-127413, JP-A-8-194394, JP-A-8-334915, JP-A-8-334916, JP-A-9-171265. Those satisfying the physical properties disclosed in JP-A-10-221877 are preferred.

  The polymer for the toner image-receiving layer is excellent in environmental suitability and workability because (i) the organic solvent is not discharged in the coating and drying step. (Ii) Many release agents such as wax are difficult to dissolve in a solvent at room temperature, and are often dispersed in a solvent (water, organic solvent) in advance. In addition, the water dispersion form is more stable and more suitable for the manufacturing process. Further, in the case of aqueous coating, the wax tends to bleed on the surface during the coating and drying process, and the effects of the release agent (offset resistance, adhesion resistance, etc.) can be easily obtained. For this reason, water-based resins such as water-dispersible polymers and water-soluble polymers are preferably used.

  The water-based resin is not particularly limited in terms of its composition, bond structure, molecular structure, molecular weight, molecular weight distribution, form, etc., as long as it is either a water-dispersible polymer or a water-soluble polymer. Examples of the water-based group of the polymer include a sulfonic acid group, a hydroxyl group, a carboxylic acid group, an amino group, an amide group, and an ether group.

The water-dispersible polymer is appropriately selected from, for example, resins, emulsions, copolymers, mixtures, and cation-modified products obtained by dispersing the thermoplastic resins (1) to (9) in water. More than one species can be combined.
As the water-dispersible polymer, an appropriately synthesized product or a commercially available product may be used. Examples of the commercially available products include polyester-based water-dispersible polymers such as Toyobo Co., Ltd.'s Bironal series, Takamatsu Yushi Co., Ltd. Pes Resin A series, Kao Corporation's Tufton UE series, Nippon Synthetic Chemical Co., Ltd. Examples include the Polyester WR series manufactured by Kogyo Co., Ltd., and the erière series manufactured by Unitika Ltd. Examples of the acrylic water-dispersible polymer include Hiros XE, KE, PE series manufactured by Seiko Chemical Industry Co., Ltd., and Jurimer ET series manufactured by Nippon Pure Chemical Co., Ltd.

The water-dispersible emulsion is not particularly limited as long as the volume average particle diameter is 20 nm or more, and can be appropriately selected according to the purpose. For example, water-dispersible polyurethane emulsion, water-dispersible polyester emulsion, chloroprene-based emulsion Emulsion, styrene-butadiene emulsion, nitrile-butadiene emulsion, butadiene emulsion, vinyl chloride emulsion, vinylpyridine-styrene-butadiene emulsion, polybutene emulsion, polyethylene emulsion, vinyl acetate emulsion, ethylene-vinyl acetate emulsion Emulsions, vinylidene chloride emulsions, methyl methacrylate-butadiene emulsions and the like can be mentioned. Among these, a water dispersible polyester emulsion is particularly preferable.
The water-dispersible polyester emulsion is preferably a self-dispersing water-based polyester emulsion, and among them, a carboxyl group-containing self-dispersing water-based polyester resin emulsion is particularly preferable. Here, the self-dispersing water-based polyester emulsion means an aqueous emulsion containing a polyester resin that can self-disperse in an aqueous solvent without using an emulsifier or the like. The carboxyl group-containing self-dispersing aqueous polyester resin emulsion means an aqueous emulsion containing a carboxyl resin as a hydrophilic group and containing a polyester resin that can be self-dispersed in an aqueous solvent.

The self-dispersing water-dispersible polyester emulsion preferably satisfies the following characteristics (1) to (4). Since this is a self-dispersion type that does not use a surfactant, it has low hygroscopicity even in a high humidity atmosphere, and there is little decrease in the softening point due to moisture, and it is possible to suppress occurrence of offset at the time of fixing and adhesion failure between sheets at the time of storage. Moreover, since it is water-based, it is excellent in environmental performance and workability. In addition, since a polyester resin with a high cohesive energy and a molecular structure is used, it has a sufficient hardness in the storage environment, but it becomes a low elasticity (low viscosity) molten state in the electrophotographic fixing process, and the toner receives an image. Sufficient image quality can be achieved by embedding in the layer.
(1) The number average molecular weight (Mn) is preferably 5000 to 10,000, and more preferably 5000 to 7000.
(2) The molecular weight distribution (weight average molecular weight / number average molecular weight) is preferably 4 or less, and more preferably Mw / Mn ≦ 3.
(3) The glass transition temperature (Tg) is preferably 40 to 100 ° C, more preferably 50 to 80 ° C.
(4) The volume average particle diameter is preferably 20 to 200 nm, more preferably 40 to 150 mm.
The content of the water-dispersible emulsion in the toner image-receiving layer is preferably 10 to 90% by mass, and more preferably 10 to 70% by mass.

The water-soluble polymer is not particularly limited as long as the weight average molecular weight (Mw) is 400,000 or less, and can be appropriately selected according to the purpose. For example, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, cellulose sulfate, polyethylene oxide, gelatin, cationized starch, casein, sodium polyacrylate, styrene-maleic anhydride copolymer Examples thereof include sodium combined sodium and sodium polystyrene sulfonate. Among these, polyethylene oxide is preferable.
Commercially available products of the water-soluble polymer include water-soluble polyesters plus various coats manufactured by Kureai Chemical Industry Co., Ltd., Finetex ES series manufactured by Dainippon Ink and Chemicals, and Nippon Pure Chemical Co., Ltd. as water-soluble acrylics. Jurimer AT series, Dainippon Ink and Chemicals Finetex 6161, K-96; Seiko Chemical Industry Co., Ltd. high loss NL-1189, BH-997L, etc. are mentioned.
Examples of the water-soluble polymer include Research Disclosure No. 17,643, page 26, Research Disclosure No. 18,716, page 651, Research Disclosure No. 307,105, pages 873-874, and JP-A 64- The thing described in 13546 gazette is mentioned.

The content of the water-soluble polymer in the toner image-receiving layer is not particularly limited and can be appropriately selected according to the purpose, and is preferably 0.5 to ² g / m ² .

Although the said thermoplastic resin can also be used together with another polymer material, in that case, generally it is used so that content may become larger than another polymer material.
The content of the thermoplastic resin for the toner image-receiving layer in the toner image-receiving layer is preferably 10% by mass or more, more preferably 30% by mass or more, still more preferably 50% by mass or more, and particularly preferably 50 to 90% by mass. .

-Release agent-
The release agent is blended in the toner image receiving layer in order to prevent the toner image receiving layer from being offset. The release agent used in the present invention is heated and melted at the fixing temperature, deposited on the surface of the toner image-receiving layer, unevenly distributed on the surface of the toner image-receiving layer, and further cooled and solidified to form the surface of the toner image-receiving layer. The type of the release agent material is not particularly limited as long as it forms a layer of the release agent material, and can be appropriately selected according to the purpose.
Examples of the release agent include at least one selected from a silicone compound, a fluorine compound, a wax, and a matting agent.

  As the mold release agent, for example, compounds described in Sachishobo "Revised Wax Properties and Applications", a silicone handbook published by Nikkan Kogyo Shimbun, Ltd. can be used. Also, Japanese Patent Publication No. 59-38581, Japanese Patent Publication No. 4-32380, Japanese Patent No. 2838498, Japanese Patent No. 2949558, Japanese Patent Application Laid-Open No. 50-117433, Japanese Patent Application Laid-Open No. 52-52640, Japanese Patent Application Laid-Open No. 57-148755, JP 61-62056, JP 61-62057, JP 61-118760, JP 2-42451, JP 3-41465, JP 4-212175, JP 4-214570. JP-A-4-263267, JP-A-5-34966, JP-A-5-119514, JP-A-6-59502, JP-A-6-161150, JP-A-6-175396, JP-A-6-219040. JP-A-6-230600, JP-A-6-295093, JP-A-7-36210, JP-A-7-43940, JP-A-7-56387. JP-A-7-56390, JP-A-7-64335, JP-A-7-199681, JP-A-7-223362, JP-A-7-287413, JP-A-8-184992, JP-A-8-227180, Special Kaihei 8-248671, JP-A-8-248799, JP-A-8-248801, JP-A-8-278663, JP-A-9-152727, JP-A-9-160278, JP-A-9-185181, JP-A-9-185181 No. 9-319139, JP-A-9-319143, JP-A-10-20549, JP-A-10-48889, JP-A-10-198069, JP-A-10-207116, JP-A-11-2917, JP-A-11-11. -44969, JP-A-11-65156, JP-A-11-73049, JP-A-11-194542 Silicone compound used in the toner, fluorine compounds or waxes (excluding natural wax) can also be preferably used that. Further, a plurality of these compounds can be used in combination.

  Examples of the silicone compound include silicone oil, silicone rubber, silicone fine particles, silicone-modified resin, and reactive silicone compound.

Examples of the silicone oil include non-modified silicone oil, amino-modified silicone oil, carboxy-modified silicone oil, carbinol-modified silicone oil, vinyl-modified silicone oil, epoxy-modified silicone oil, polyether-modified silicone oil, silanol-modified silicone oil, Examples include methacryl-modified silicone oil, mercapto-modified silicone oil, alcohol-modified silicone oil, alkyl-modified silicone oil, and fluorine-modified silicone oil.
Examples of the silicone-modified resin include olefin resin, polyester resin, vinyl resin, polyamide resin, cellulose resin, phenoxy resin, vinyl chloride-vinyl acetate resin, urethane resin, acrylic resin, styrene-acrylic resin, or a copolymer thereof. Examples include resins obtained by modifying the resin with silicone.

  The fluorine compound is not particularly limited and may be appropriately selected depending on the purpose. For example, fluorine oil, fluorine rubber, fluorine-modified resin, fluorine sulfonic acid compound, fluorosulfonic acid, fluoric acid compound or a salt thereof, An inorganic fluoride etc. are mentioned.

The wax can be roughly classified into natural wax and synthetic wax.
The natural wax is preferably at least one selected from plant waxes, animal waxes, mineral waxes and petroleum waxes, and among these, plant waxes are particularly preferred. The natural wax is particularly preferably a water-dispersed wax from the viewpoint of compatibility when a water-based resin is used as the polymer for the toner image-receiving layer.

There is no restriction | limiting in particular as said plant-type wax, It can select suitably from well-known things, A commercial item may be sufficient and what was synthesize | combined suitably may be sufficient. Examples of the plant wax include carnauba wax, castor oil, rapeseed oil, soybean oil, wood wax, cotton wax, rice wax, sugarcane wax, candelilla wax, Japan wax, jojoba oil and the like.
Examples of the commercially available carnauba wax include EMUSTAR-0413 manufactured by Nippon Seiki Co., Ltd., Cellosol 524 manufactured by Chukyo Yushi Co., Ltd., and the like. As a commercial item of the said castor oil, the refined castor oil by Ito Oil Co., Ltd., etc. are mentioned.
Among these, in particular, it has an excellent anti-offset property, anti-adhesion property, paper passing property, glossiness, is resistant to cracking, and can provide an electrophotographic image-receiving sheet capable of forming a high-quality image. Is particularly preferably carnauba wax having a temperature of 70 to 95 ° C.

  There is no restriction | limiting in particular as said animal-type wax, It can select suitably from well-known things, For example, beeswax, lanolin, spermaceti, stew wax (whale oil), wool wax etc. are mentioned.

There is no restriction | limiting in particular as said mineral-type wax, It can select suitably from well-known things, A commercial item may be sufficient and what was synthesize | combined suitably may be sufficient. Examples thereof include montan wax, montan ester wax, ozokerite, ceresin and the like.
Among these, in particular, it has an excellent offset resistance, adhesion resistance, paper permeability, glossiness, is resistant to cracking, and can provide an electrophotographic image-receiving sheet capable of forming a high-quality image. Is particularly preferably a montan wax having a temperature of 70 to 95 ° C.

  There is no restriction | limiting in particular as said petroleum wax, It can select suitably from well-known things, A commercial item may be sufficient and what was synthesize | combined suitably may be sufficient. Examples thereof include paraffin wax, microcrystalline wax, and petrolatum.

The content in the toner image-receiving layer of the natural wax is preferably ^{0.1~4g / m 2, 0.2~2g / m} 2 is more preferable.
When the content is less than 0.1 g / m ² , offset resistance and adhesion resistance may be particularly insufficient. When the content exceeds 4 g / m ² , the amount of wax is excessive and an image is formed. May have poor image quality.

  The melting point (° C.) of the natural wax is particularly preferably 70 to 95 ° C. and more preferably 75 to 90 ° C. from the viewpoint of offset resistance and paper passing.

  The synthetic wax is classified into synthetic hydrocarbons, modified waxes, hydrogenated waxes, and other oil-based synthetic waxes. These waxes are preferably water-dispersed waxes in view of compatibility when a water-based thermoplastic resin is used as the thermoplastic resin of the toner image-receiving layer.

Examples of the synthetic hydrocarbon include Fischer-Tropsch wax and polyethylene wax.
Examples of the oil-based synthetic wax include acid amide compounds (such as stearamide) and acid imide compounds (such as phthalic anhydride imide).

  The modified wax is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include amine-modified wax, acrylic acid-modified wax, fluorine-modified wax, olefin-modified wax, urethane-type wax, and alcohol-type wax. Can be mentioned.

  The hydrogenated wax is not particularly limited and may be appropriately selected depending on the intended purpose.For example, hydrogenated castor oil, castor oil derivative, stearic acid, lauric acid, myristic acid, palmitic acid, behenic acid, sebacic acid, Examples include undecylenic acid, heptylic acid, maleic acid, highly maleated oil, and the like.

The melting point (° C.) of the release agent is preferably 70 to 95 ° C., and more preferably 75 to 90 ° C., particularly in terms of offset resistance and paper passing properties.
In addition, as a release agent added to the toner image-receiving layer of the present invention, these derivatives, oxides, purified products, and mixtures can also be used. Moreover, these may have a reactive substituent.

The content of the release agent is preferably 0.1 to 10% by mass, more preferably 0.3 to 8.0% by mass, and 0.5 to 5.0% by mass based on the mass of the toner image-receiving layer. Is more preferable.
When the content is less than 0.1% by mass, the offset resistance and adhesion resistance may be insufficient. When the content exceeds 10% by mass, the amount of the release agent is excessively large. Image quality may be degraded.

-Plasticizer-
There is no restriction | limiting in particular as said plasticizer, The plasticizer for well-known resin can be suitably selected according to the objective. The plasticizer has a function of adjusting the flow or softening of the toner image-receiving layer by heat or pressure when fixing the toner.
Examples of the plasticizer include “Chemical Handbook” (edited by the Chemical Society of Japan, Maruzen), “Plasticizer—its theory and application” (written by Koichi Murai, Koshobo), “Research on plasticizers”, “Research on plasticizers” "Lower" (edited by Polymer Chemistry Association), "Handbook Rubber and Plastic Compounded Chemicals" (edited by Rubber Digest Co., Ltd.), etc.

Examples of the plasticizer include those described as high-boiling organic solvents and thermal solvents. For example, JP-A-59-83154, JP-A-59-178451, JP-A-59-178453, JP 59-178454, JP 59-178455, JP 59-178457, JP 62-174754, JP 62-245253, JP 61-209444, JP Described in JP-A-61-200538, JP-A-62-2145, JP-A-62-2348, JP-A-62-2247, JP-A-62-136646, JP-A-2-235694, etc. Esters such as phthalates, phosphate esters, fatty acid esters, abietic acid esters, adipic acid esters, sebacic acid esters, Gelaic acid esters, benzoic acid esters, butyric acid esters, epoxidized fatty acid esters, glycolic acid esters, propionic acid esters, trimellitic acid esters, citric acid esters, sulfonic acid esters, carboxylic acid esters Succinic acid esters, maleic acid esters, fumaric acid esters, phthalic acid esters, stearic acid esters, etc.), amides (for example, fatty acid amides, sulfoamides, etc.), ethers, alcohols, lactones And compounds such as polyethyleneoxys.
These plasticizers can be used by mixing with a resin.

Further, as the plasticizer, a relatively low molecular weight polymer can be used. The molecular weight of the plasticizer is preferably lower than the molecular weight of the binder resin to be plasticized, and the molecular weight is preferably 15000 or less, more preferably 5000 or less. In the case of a polymer plasticizer, the polymer is preferably the same type as the binder resin to be plasticized. For example, a low molecular weight polyester is preferable for plasticizing a polyester resin. Furthermore, oligomers can also be used as plasticizers.
In addition to the compounds listed above, commercially available products include, for example, Adekasizer PN-170, PN-1430 (all manufactured by Asahi Denka Kogyo Co., Ltd.), PARAPLEX-G-25, G-30, G-40 (any C.P.HALL), ester gum 8L-JA, ester R-95, pentalin 4851, FK115, 4820, 830, Louisol 28-JA, picorastic A75, picotex LC, crystallx 3085 (all rationalized) Hercules).

The plasticizer is used for stress and strain generated when 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 be used arbitrarily to alleviate.
The plasticizer may be in a micro-dispersed state in the toner image-receiving layer, in a micro-phase-separated state in a sea island shape, or in a state sufficiently mixed and dissolved with other components such as a binder. .
The content of the plasticizer in the toner image-receiving layer is preferably 0.001 to 90% by mass, more preferably 0.1 to 60% by mass, and still more preferably 1 to 40% by mass.
The plasticizer adjusts smoothness (improves transportability due to reduced frictional force), improves fixing unit offset (detachment of toner and layers from the fixing unit), adjusts curl balance, and adjusts charging (toner electrostatic image It may be used for the purpose of forming).

-Colorant-
There is no restriction | limiting in particular as said colorant, According to the objective, it can select suitably, A fluorescent whitening agent, a white pigment, a colored pigment, dye, etc. are mentioned.
The fluorescent brightening agent is not particularly limited as long as it is a known compound that absorbs in the near ultraviolet region and emits fluorescence at 400 to 500 nm, and can be appropriately selected from known compounds. Preferable examples include compounds described in “The Chemistry of Synthetic Dies”, Volume V, Chapter 8, edited by Veen Rataraman. The fluorescent whitening agent may be a commercially available product or an appropriately synthesized product, for example, a stilbene compound, a coumarin compound, a biphenyl compound, a benzoxazoline compound, or a naphthalimide compound. , Pyrazoline compounds, carbostyryl compounds, and the like. Examples of the commercially available products include white full fur PSN, PHR, HCS, PCS, B (all manufactured by Sumitomo Chemical Co., Ltd.), UVITEX-OB (manufactured by Ciba-Geigy), and the like.

  There is no restriction | limiting in particular as said white pigment, According to the objective, it can select suitably according to the objective, For example, inorganic pigments, such as a titanium oxide and a calcium carbonate, can be used.

The colored pigment is not particularly limited and may be appropriately selected from known ones according to the purpose. Examples thereof include various pigments, azo pigments, and many described in JP-A-63-44653. Examples thereof include cyclic pigments, condensed polycyclic pigments, lake pigments, and carbon black.
Examples of the azo pigment include azo lake (eg, Carmine 6B, Red 2B, etc.), insoluble azo pigment (eg, monoazo yellow, disazo yellow, pyrazolo orange, vulcan orange, etc.), condensed azo pigment (eg, chromophthal yellow, chromo). Phthared).
Examples of the polycyclic pigment include phthalocyanine pigments such as copper phthalocyanine blue and copper phthalocyanine green.
Examples of the condensed polycyclic pigment include dioxazine pigments (such as dioxazine violet), isoindolinone pigments (such as isoindolinone yellow), selenium pigments, perylene pigments, perinone pigments, and thioindigo pigments. Can be mentioned.
Examples of the lake pigment include malachite green, rhodamine B, rhodamine G, and Victoria blue B.
Examples of the inorganic pigment include oxides (for example, titanium dioxide, bengara, etc.) sulfates (for example, precipitated barium sulfate), carbonates (for example, precipitated calcium carbonate), oxalates (for example, water-containing materials) Succinate, anhydrous succinate, etc.), metal powders (for example, aluminum powder, bronze powder, zinc dust, yellow lead, bitumen), and the like.
These may be used alone or in combination of two or more.

There is no restriction | limiting in particular as said dye, According to the objective, it can select suitably according to the objective, For example, an anthraquinone type compound, an azo type compound, etc. are mentioned. These may be used alone or in combination of two or more.
Examples of water-insoluble dyes include vat dyes, disperse dyes, and oil-soluble dyes. Examples of the vat dyes include C.I. I. Vat violet 1, C.I. I. Vat violet 2, C.I. I. Vat violet 9, C.I. I. Vat violet 13, C.I. 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 etc. are mentioned. Examples of the disperse dye include C.I. I. Dispers 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 Blue 58 etc. are mentioned. Examples of the oil-soluble dye include C.I. I. Solvent Violet 13, C.I. I. Solvent Violet 14, C.I. I. Solvent Violet 21, C.I. I. Solvent Violet 27, C.I. I. Solvent Blue 11, C.I. I. Solvent Blue 12, C.I. I. Solvent Blue 25, C.I. I. Solvent Blue 55 etc. are mentioned.
In addition, a colored coupler used in silver salt photography can also be suitably used.

Of the colorant, the content in the toner image-receiving layer is preferably ^{0.1~8g / m 2, 0.5~5g / m} 2 is more preferable.
When the content of the colorant is less than 0.1 g / m ² , the light transmittance in the toner image-receiving layer may be increased. When the content exceeds 8 g / m ² , handling properties such as cracking and adhesion resistance are improved. May be inferior.
Among the colorants, the amount of the pigment added is preferably 40% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less based on the mass of the thermoplastic resin constituting the toner image receiving layer. preferable.

As said filler, an organic or inorganic filler is mentioned, A well-known thing can be used as a reinforcing agent for binder resin, a filler, and a reinforcing material. The filler should be selected with reference to "Handbook Rubber / Plastic Compounding Chemicals" (edited by Rubber Digest Co., Ltd.), "New Edition Plastic Compounding Agent Basics and Applications" (Taiseisha), "Filler Handbook" (Taiseisha), etc. Can do.
Moreover, an inorganic filler or an inorganic pigment can be used as the filler. Examples of the inorganic filler or inorganic pigment include silica, alumina, titanium dioxide, zinc oxide, zirconium oxide, mica-like iron oxide, lead white, lead oxide, cobalt oxide, strontium chromate, molybdenum-based pigment, smectite, magnesium oxide, Examples include calcium oxide, calcium carbonate, and mullite. Among these, silica and alumina are particularly preferable. These may be used alone or in combination of two or more. The filler preferably has a small particle size. If the particle size is large, the surface of the toner image-receiving layer tends to be roughened.

  The silica includes spherical silica and amorphous silica. The silica can be synthesized by a dry method, a wet method, or an airgel method. The surface of the hydrophobic silica particles may be surface-treated with a trimethylsilyl group or silicone. As the silica, colloidal silica is preferable. The silica is preferably porous.

The alumina includes anhydrous alumina and alumina hydrate. As the crystal form of the anhydrous alumina, α, β, γ, δ, ζ, η, θ, κ, ρ, or χ can be used, and alumina hydrate is preferable to anhydrous alumina. As the alumina hydrate, monohydrate or trihydrate can be used. The monohydrate includes pseudo boehmite, boehmite and diaspore. The trihydrate includes dibsite and bayerite. The alumina is preferably porous.
The alumina hydrate can be synthesized by a sol-gel method in which ammonia is added to an aluminum salt solution for precipitation or a method in which an alkali aluminate is hydrolyzed. The anhydrous alumina can be obtained by dehydrating alumina hydrate by heating.

  The amount of the filler added is preferably 5 to 2000 parts by mass with respect to 100 parts by mass of the dry mass of the binder of the toner image receiving layer.

The cross-linking agent can be blended to adjust the storage stability, thermoplasticity, etc. of the toner image-receiving layer. As the crosslinking agent, a compound having two or more known reactive groups in the molecule as the reactive group, such as an epoxy group, an isocyanate group, an aldehyde group, an active halogen group, an active methylene group, an acetylene group, or the like is used.
As the crosslinking agent, a compound having two or more groups capable of forming a bond by a hydrogen bond, an ionic bond, a coordinate bond, or the like can be used.
As the crosslinking agent, for example, a known compound can be used as a coupling agent for a resin, a curing agent, a polymerization agent, a polymerization accelerator, a coagulant, a film-forming agent, a film-forming auxiliary, and the like. Examples of the coupling agent include chlorosilanes, vinyl silanes, epoxy silanes, aminosilanes, alkoxyaluminum chelates, titanate coupling agents, etc., and “Handbook Rubber / Plastic Compounding Chemicals” (edited by Rubber Digest Co., Ltd.). ) Etc. can be used.

The toner image receiving layer of the present invention preferably contains a charge adjusting agent in order to adjust the transfer or adhesion of the toner or prevent the toner image receiving layer from being charged and adhered.
There is no restriction | limiting in particular as said charge control agent, Conventionally well-known various charge control agents can be used suitably according to the objective. The charge control agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a surfactant such as a cationic surfactant, an anionic surfactant, an amphoteric surfactant, or a nonionic surfactant. In addition to the agent, a polymer electrolyte, a conductive metal oxide, and the like can be used. Specifically, quaternary ammonium salts, polyamine derivatives, cation-modified polymethyl methacrylate, cationic antistatic agents such as cation-modified polystyrene, anionic antistatic agents such as alkyl phosphates and anionic polymers, fatty acid esters, polyethylene oxide Nonionic antistatic agents such as
When the toner has a negative charge, for example, a cation or a nonion is preferable as the charge adjusting agent to be blended in the toner image receiving layer.
Examples of the conductive metal oxide include ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, and MoO ₃ . These may be used alone or in combination of two or more. The conductive metal oxide may further contain (doping) a different element, for example, Al, In, etc. with respect to ZnO, Nb, Ta, etc. with respect to TiO ₂ , and SnO ₂ . Can contain (doping) Sb, Nb, a halogen element, or the like.

-Other additives-
The material that can be used in the toner image-receiving layer of the present invention can contain various additives for improving the stability of the output image and improving the stability of the toner image-receiving layer itself. Examples of the additive include various known antioxidants, antioxidants, deterioration inhibitors, ozone deterioration inhibitors, ultraviolet absorbers, metal complexes, light stabilizers, preservatives, fungicides, and the like.

  There is no restriction | limiting in particular as said antioxidant, According to the objective, it can select suitably, For example, a chroman compound, a coumaran compound, a phenol compound (for example, hindered phenol), a hydroquinone derivative, a hindered amine derivative, a spiroindane compound is mentioned. Can be mentioned. The antioxidant is described in JP-A No. 61-159644.

  There is no restriction | limiting in particular as said anti-aging agent, According to the objective, it can select suitably, For example, it describes in "Handbook rubber and plastic compounding chemicals revised 2nd edition" (1993, Rubber Digest company) p76-121. Can be mentioned.

  There is no restriction | limiting in particular as said ultraviolet absorber, According to the objective, it can select suitably, For example, a benzotriazole compound (refer U.S. Pat. No. 3,533,794), 4-thiazolidone compound (U.S. Pat. No. 3,352,681) And benzophenone compounds (see JP-A No. 46-2784), and UV-absorbing polymers (see JP-A No. 62-260152).

There is no restriction | limiting in particular as said metal complex, According to the objective, it can select suitably, For example, each specification of U.S. Pat. No. 4,241,155, U.S. Pat. No. 4,245,018, U.S. Pat. Those described in JP-A-88256, JP-A-62-174741, JP-A-63-199248, JP-A-1-75568, and JP-A-1-74272 are suitable.
Further, ultraviolet absorbers and light stabilizers described in "Handbook Rubber / Plastic Compounding Chemicals Revised 2nd Edition" (1993, Rubber Digest Co., Ltd.) p122 to 137 can also be suitably used.

  In addition, as described above, a known photographic additive can be added to the material that can be used for the toner image-receiving layer of the present invention, if necessary. Examples of the photographic additive include Research Disclosure Magazine (hereinafter abbreviated as RD) No. 17643 (December 1978), RD No. 18716 (November 1979) and RD No. 307105 (November 1989), and the corresponding parts are summarized in the following table.

  The toner image-receiving layer of the present invention is provided by applying a coating liquid containing the toner image-receiving layer thermoplastic resin on the support with a wire coater or the like and drying. The film forming temperature (MFT) of the thermoplastic resin used in the present invention is preferably room temperature or higher for storage before printing, and preferably 100 ° C. or lower for fixing toner particles.

Toner image-receiving layer of the present invention, the coating weight after drying, for example, preferably ^{1~20g / m 2, 4~15g / m} 2 is more preferable.
The thickness of the toner image-receiving layer is not particularly limited and may be appropriately selected depending on the purpose. More specifically, 1-50 micrometers is preferable, 1-30 micrometers is more preferable, 2-20 micrometers is still more preferable, and 5-15 micrometers is especially preferable.

[Physical properties of toner image-receiving layer]
The toner image-receiving layer has a 180 degree peel strength at a fixing temperature with the fixing member of preferably 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 according to the method described in JIS K6887 using the surface material of the fixing member.
The toner image receiving layer preferably has a high whiteness. The whiteness is preferably 85% or more as measured by the method defined in JIS P 8123. In addition, in the wavelength region of 440 nm to 640 nm, the spectral reflectance is preferably 85% or more, and the difference between the maximum spectral reflectance and the minimum spectral reflectance in the same wavelength region is preferably within 5%. Further, the spectral reflectance is preferably 85% or more in the wavelength region of 400 nm to 700 nm, and the difference between the maximum spectral reflectance and the minimum spectral reflectance in the same wavelength region is more preferably within 5%.
Specifically, as the whiteness, in the CIE 1976 (L ^* a ^* b ^* ) color space, the L ^* value is preferably 80 or more, more preferably 85 or more, and still more preferably 90 or more. The white color is preferably as neutral as possible. As a white color, in the L ^* a ^* b ^* space, the value of (a ^* ) ² + (b ^* ) ² is preferably 50 or less, more preferably 18 or less, and still more preferably 5 or less.

The toner image receiving layer preferably has high gloss after image formation. The glossiness is preferably 60 or more, more preferably 75 or more, and still more preferably 90 or more in the entire region from white without toner to black having the maximum density.
However, the glossiness is preferably 110 or less. If it exceeds 110, it becomes like a metallic luster, which is not preferable as an image quality.
Here, the glossiness can be measured based on, for example, JIS Z8741.

The toner image receiving layer preferably has high smoothness after fixing. As the smoothness, the arithmetic average roughness (Ra) is preferably 3 μm or less, more preferably 1 μm or less, and even more preferably 0.5 μm or less in the entire region from white without toner to black having the maximum density.
Here, the arithmetic mean roughness can be measured based on, for example, JIS B0601, JIS B0651, and JIS B0652.

The toner image-receiving layer preferably has a physical property of one item in the following items, more preferably has a physical property of a plurality of items, and further preferably has a physical property of all items.
(1) Tm (melting temperature) of the toner image-receiving layer is preferably 30 ° C. or higher, and preferably Tm + 20 ° C. or lower of the toner.
(2) The temperature at which the viscosity of the toner image-receiving layer becomes 1 × 10 ⁵ cp is preferably 40 ° C. or higher, and is preferably lower than that of the toner.
(3) 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. preferable.
(4) 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 preferably from 0.01 to 10.
(5) The storage elastic modulus (G ′) at the fixing temperature of the toner image-receiving layer is preferably −50 to +2500 with respect to the storage elastic modulus (G ′) at the fixing temperature of the toner.
(6) The inclination angle of the molten toner on the toner image-receiving layer is preferably 50 degrees or less, and more preferably 40 degrees or less.
The toner image-receiving layer satisfies the physical properties disclosed in Japanese Patent No. 2788358, Japanese Patent Laid-Open No. 7-248637, Japanese Patent Laid-Open No. 8-305067, Japanese Patent Laid-Open No. 10-239889, and the like. preferable.

The surface electric resistance of the toner image-receiving layer is preferably in the range of 1 × 10 ⁶ to 1 × 10 ¹⁵ Ω / cm ² (under the condition of 25 ° C.-65% RH).
If the surface resistance is less than 1 × 10 ⁶ Ω / cm ² , 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. If it exceeds × 10 ¹⁵ Ω / cm ² , an excessive charge is generated at the time of transfer, the toner is not sufficiently transferred, the density of the image is low, and electrostatic charge is generated during handling of the electrophotographic image receiving sheet. It becomes easy to adhere. Misfeeds, double feeds, discharge marks, toner transfer missing, etc. may occur during copying.
Here, the surface electrical resistance is based on JIS K6911, the sample is conditioned for 8 hours or more in an environment of a temperature of 20 ° C. and a humidity of 65%, and under the same environment, R8340 manufactured by Advantest Corporation is used. It can be obtained by measuring after one minute has passed after energization under the condition of an applied voltage of 100V.

[Back layer]
In the electrophotographic image-receiving sheet, the back layer is provided on the opposite side of the toner image-receiving layer with respect to the support for the purpose of imparting back-surface output suitability, improving back-surface output image quality, improving curl balance, and improving device passability. It is preferred that
Although there is no restriction | limiting in particular as a color of the said back layer, When the said electrophotographic image receiving sheet is a double-sided output type image receiving sheet which forms an image also in a back surface, it is preferable that a back layer is also white. The whiteness and the spectral reflectance are preferably 85% or more like the surface.
In order to improve both-side output suitability, the configuration of the back layer may be the same as that on the toner image-receiving layer side. Various additives described above can be used for the back layer. As such an additive, it is particularly suitable to mix a matting agent, a charge adjusting agent, or the like. The back layer may have a single layer configuration or a stacked configuration of two or more layers.
In order to prevent offset at the time of fixing, when a release oil is used for the fixing roller or the like, the back layer may be oil-absorbing.
The thickness of the back layer is usually preferably from 0.1 to 10 μm.

[Other layers]
Other layers in the electrophotographic image-receiving sheet include, for example, a surface protective layer, an adhesion improving layer, an intermediate layer, an undercoat layer, a cushion layer, a charge control (prevention) layer, a reflective layer, a tint adjusting layer, and a storage stability improvement. A layer, an adhesion preventing layer, an anti-curl layer, and a smoothing layer. These layers may be composed of a single layer or may be composed of two or more layers.

-Surface protective layer-
The surface protective layer is used for the purpose of protecting the surface of the electrophotographic image-receiving sheet, improving storage stability, improving handleability, imparting writing properties, improving instrument passability, imparting anti-offset properties, and the like. It can be provided on the surface of the image receiving layer. The surface protective layer may be a single layer or may be composed of two or more layers. In the surface protective layer, various thermoplastic resins, thermosetting resins, and the like can be used as a binder, and it is preferable to use the same type of resin as the toner image receiving layer. However, thermodynamic characteristics, electrostatic characteristics, and the like do not need to be the same as those of the toner image-receiving layer, and can be optimized.

The surface protective layer may contain the various additives described above that can be used for the toner image-receiving layer. In particular, the surface protective layer may be blended with other additives such as a matting agent in addition to the release agent used in the present invention. In addition, as said mat agent, various well-known things are mentioned.
The outermost surface layer in the electrophotographic image-receiving sheet (for example, the surface protective layer when a surface protective layer is formed) preferably has good compatibility with the toner from the viewpoint of fixability. Specifically, the contact angle with the melted toner is preferably, for example, 0 to 40 degrees.

-Adhesion improvement layer, etc.-
The adhesion improving layer is preferably formed for the purpose of improving the adhesion between the support and the toner image receiving layer in the electrophotographic image receiving sheet. The above-mentioned various additives can be blended in the adhesion improving layer, and it is particularly preferable to blend a crosslinking agent. The electrophotographic image receiving sheet of the present invention preferably further comprises a cushion layer or the like between the adhesion improving layer and the toner image receiving layer in order to improve the toner acceptability.

-Intermediate layer-
The intermediate layer is formed, for example, between the support and the adhesion improving layer, between the adhesion improving layer and the cushion layer, between the cushion layer and the toner image receiving layer, and between the toner image receiving layer and the storage stability improving layer. Can do. Of course, in the case of an electrophotographic image-receiving sheet comprising a support, a toner image-receiving layer, and an intermediate layer, the intermediate layer can be present, for example, between the support and the toner image-receiving layer.

  The thickness of the electrophotographic image-receiving sheet of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 50 to 550 μm is preferable, and 100 to 350 μm is more preferable.

<Toner>
The electrophotographic image-receiving sheet of the present invention is used by allowing the toner image-receiving layer to receive toner during printing or copying.
The toner contains at least a binder resin and a colorant, and further contains a release agent and other components as necessary.

-Toner binder resin-
The binder resin is not particularly limited, and can be appropriately selected from those usually used for toner according to the purpose. For example, styrenes such as styrene and parachlorostyrene; vinyl naphthalene, vinyl chloride Vinyl esters such as vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, Methylene aliphatic carboxylic acid esters such as n-octyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate; acrylonitrile, methacrylonitrile, Vinyl nitrile such as acrylamide Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; methacrylic acid, acrylic A homopolymer of vinyl monomers such as vinyl carboxylic acids such as acid and cinnamic acid or copolymers thereof, and various polyesters can be used, and various waxes can be used in combination.
Among these resins, it is preferable to use a resin of the same system as that used in the toner image receiving layer of the present invention.

-Toner colorant-
The colorant is not particularly limited and may be appropriately selected from those used in normal toners according to the purpose. For example, carbon black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline Yellow, Permanent Orange GTR, Pyrazolone Orange, Vulcan Orange, Watch Young Red, Permanent Red, Brilliantamine 3B, Brilliantamine 6B, Dapon Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Rose Bengal Various pigments such as aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, and malachite green oxalelate It is. Acridine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, thioindico, phthalocyanine, aniline black, polymethine, triphenyl Examples include various dyes such as methane, diphenylmethane, thiazine, thiazole, and xanthene.
These colorants may be used alone or in combination of two or more.
There is no restriction | limiting in particular in content of the said coloring agent, According to the objective, it can select suitably, The range of 2-8 mass% is preferable. When the content of the colorant is less than 2% by mass, the coloring power may be weakened, and when it exceeds 8% by mass, the transparency may be impaired.

-Toner release agent-
The release agent is not particularly limited and may be appropriately selected from those usually used for toner according to the purpose. For example, a relatively low molecular weight highly crystalline polyethylene wax or Fischer-Tropsch wax is used. In particular, polar waxes containing nitrogen, such as amide waxes and compounds having urethane bonds, are particularly effective.
The molecular weight of the polyethylene wax is preferably 1000 or less, and more preferably 300 to 1000.
The compound having a urethane bond is preferable because even if it has a low molecular weight, the solid state can be maintained and the melting point can be set high for the molecular weight due to the strength of cohesive force due to the polar group. A preferable range of the molecular weight is 300 to 1,000. Raw materials are combinations of diisocyanate compounds and monoalcohols, combinations of monoisocyanic acid and monoalcohols, combinations of dialcohols and monoisocyanic acid, combinations of trialcohols and monoisocyanic acid, triisocyanic acid Various combinations such as a combination of compounds and monoalcohols can be selected, but in order not to increase the molecular weight, it is preferable to combine a compound of a polyfunctional group and a monofunctional group, and an equivalent functional group It is important to be in quantity.

Examples of the monoisocyanate compound include dodecyl isocyanate, phenyl isocyanate and derivatives thereof, naphthyl isocyanate, hexyl isocyanate, benzyl isocyanate, butyl isocyanate, and allyl isocyanate.
Examples of the diisocyanate compound include tolylene diisocyanate, 4,4'diphenylmethane, toluene diisocyanate, 1,3-diisocyanate 1,3-phenylene, hexamethylene diisocyanate, 4-methyl-m-phenylene diisocyanate, and diisocyanate. Examples include isophorone.
Examples of the monoalcohol include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol and the like.
Examples of the dialcohols include numerous glycols such as ethylene glycol, diethylene glycol, triethylene glycol, and trimethylene glycol; examples of the trialcohols include trimethylolpropane, triethylolpropane, and trimethanolethane.

  These urethane compounds can be mixed with a resin and a colorant at the time of kneading and used as a kneaded and pulverized toner as in a normal release agent. In addition, when used in the emulsion polymerization aggregation melting toner described above, it is dispersed together with an ionic surfactant, a polymer electrolyte such as a polymer acid or a polymer base in water, heated to a temperature higher than the melting point, and then a homogenizer or pressure discharge. It can be made into fine particles by applying strong shearing with a mold disperser to prepare a release agent particle dispersion of 1 μm or less, which can be used together with a resin particle dispersion, a colorant dispersion and the like.

-Other components of toner-
The toner may contain other components such as an internal additive, a charge control agent, and inorganic fine particles. As said internal additive, magnetic bodies, such as metals, alloys, such as a ferrite, magnetite, reduced iron, cobalt, nickel, manganese, an alloy, or a compound containing these metals, can be used, for example.

  Examples of the charge control agent include various commonly used charge control agents such as quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments. be able to. A material that is difficult to dissolve in water is preferable from the viewpoint of controlling the ionic strength that affects the stability during aggregation and melting and reducing wastewater contamination.

  As the inorganic fine particles, for example, silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, etc., usually all external additives on the toner surface can be used, and these can be used as ionic surfactants or polymer acids. It is preferable to use it dispersed in a polymer base.

  Furthermore, a surfactant can be used for emulsion polymerization, seed polymerization, pigment dispersion, resin particle dispersion, release agent dispersion, aggregation, and stabilization thereof. For example, anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap, cationic surfactants such as amine salt type and quaternary ammonium salt type, polyethylene glycol type, alkylphenol It is also effective to use a nonionic surfactant such as an ethylene oxide adduct system or a polyhydric alcohol system in combination. As a dispersing means at that time, a general means such as a rotary shear type homogenizer, a ball mill having a media, a sand mill, or a dyno mill can be used.

An external additive may be further added to the toner as necessary. Examples of the external additive include inorganic particles and organic particles. Examples of the inorganic particles, for _{example, SiO 2, TiO 2, Al} 2 O 3, CuO, ZnO, SnO 2, Fe 2 O 3, MgO, BaO, CaO, K 2 O, Na 2 O, ZrO 2, CaO · Examples thereof include SiO ₂ , K ₂ O. (TiO ₂ ) _n , Al ₂ O ₃ .2SiO ₂ , CaCO ₃ , MgCO ₃ , BaSO ₄ , MgSO _{4 and the} like. Moreover, as said organic particle, fatty acid or its derivative (s), powders, such as these metal salts, resin powders, such as fluorine resin, a polyethylene resin, an acrylic resin, etc. can be used, for example.
For example, the average particle diameter of these particles is preferably 0.01 to 5 μm, and more preferably 0.1 to 2 μm.

  The method for producing the toner is not particularly limited and may be appropriately selected depending on the purpose. (I) A step of forming aggregated particles in a dispersion obtained by dispersing resin particles to prepare an aggregated particle dispersion (Ii) adding and mixing a fine particle dispersion in which fine particles are dispersed in the aggregated particle dispersion to adhere the fine particles to the aggregated particles to form the adhered particles; and (iii) the attached particles. The toner is preferably manufactured by a method for manufacturing a toner comprising a step of heating and coalescing to form toner particles.

-Physical properties of toner-
The volume average particle diameter of the toner of the present invention is preferably from 0.5 μm to 10 μm.
If the volume average particle size of the toner is too small, there may be an adverse effect on toner handling (replenishability, cleaning properties, fluidity, etc.), and particle productivity may be reduced. On the other hand, if the volume average particle diameter of the toner is too large, the image quality and resolution due to graininess and transferability may be adversely affected.
In addition, the toner of the present invention preferably satisfies the volume average particle size range of the toner and has a volume average particle size distribution index (GSDv) of 1.3 or less.
The ratio (GSDv / GSDn) of the volume average particle size distribution index (GSDv) to the number average particle size distribution index (GSDn) is preferably 0.95 or more.
In addition, the toner of the present invention satisfies the volume average particle diameter range of the toner, and the average value of the shape factor represented by the following formula is preferably 1.00 to 1.50.
Shape factor = (π × L ² ) / (4 × S)
(However, L represents the maximum length of toner particles, and S represents the projected area of toner particles.)
When the toner satisfies the above conditions, it is effective for image quality, particularly graininess, and resolution. Also, it is difficult to cause omission and blur due to transfer, and handling properties are hardly adversely affected even if the average particle size is not small. Become.

The storage elastic modulus G ′ (measured at an angular frequency of 10 rad / sec) at 150 ° C. of the toner itself is 1 × 10 ² to 1 × 10 ⁵ Pa. It is appropriate from the aspect of

(Image forming method)
The image forming method of the present invention includes a toner image forming step and an image surface smoothing and fixing step, and further includes other steps as necessary.

-Toner image forming process-
The toner image forming step is a step of forming a toner image on the electrophotographic image receiving sheet of the present invention.
The toner image forming step is not particularly limited as long as it can form a toner image on an electrophotographic image-receiving sheet, and can be appropriately selected according to the purpose. For example, a normal electrophotographic method can be used. The method used, for example, a direct transfer method in which a toner image formed on a developing roller is transferred to an electrophotographic image receiving sheet, or an intermediate transfer belt that is first transferred to an intermediate transfer belt or the like and then transferred to an electrophotographic image receiving sheet A method is mentioned. Among these, the intermediate transfer belt method can be preferably used in terms of environmental stability and high image quality.

-Image surface smoothing and fixing process-
The image surface smoothing and fixing step is a step of smoothing the surface of the toner image formed by the toner image forming step. In the image surface smoothing and fixing step, the toner image is heated and pressed using an image surface smoothing and fixing processor having a heating and pressing member, a belt member, and a cooling device, and then cooled and peeled off.
The image surface smoothing and fixing processor includes a heating and pressing member, a belt member, and a cooling device, and includes a cooling / separating portion and, if necessary, other members.

The heating and pressing member is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a pair of heating rollers and a combination of a heating roller and a pressing roller.
There is no restriction | limiting in particular as said cooling device, According to the objective, it can select suitably, For example, a cooling device, a heat sink, etc. which can blow cold air and can adjust cooling temperature etc. are used.
The cooling and peeling portion is not particularly limited and can be appropriately selected according to the purpose. For example, the position near the tension roll that peels from the belt by the rigidity (waist strength) of the electrophotographic image-receiving sheet itself can be mentioned. It is done.

When the toner image is brought into contact with the heating and pressing member of the image surface smoothing fixing processor, it is preferable to apply pressure. There is no restriction | limiting in particular as this pressurization method, Although it can select suitably according to the objective, It is preferable to employ | adopt a nip pressure. The nip pressure is preferably 1 to 100 kgf / cm ^{2 and} more preferably 5 to 30 kgf / cm ² from the viewpoint of forming an image having excellent water resistance and surface smoothness and good gloss. Further, the heating in the heating and pressing member is a temperature equal to or higher than the softening point of the thermoplastic resin of the toner image receiving layer, and varies depending on the toner image receiving layer thermoplastic resin to be used. . The cooling temperature in the cooling device is preferably 80 ° C. or lower, more preferably 20 to 80 ° C., at which the thermoplastic resin layer for toner image-receiving layer is sufficiently solidified.

The belt member includes a heat resistant support film and a release layer formed on the support film.
The support film is not particularly limited as long as it has heat resistance, and can be appropriately selected according to the purpose. For example, polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), Examples include polyetheretherketone (PEEK), polyethersulfone (PES), polyetherimide (PEI), polyparabanic acid (PPA), and the like.

  The release layer is preferably at least one selected from silicone rubber, fluorine rubber, fluorocarbon siloxane rubber, silicone resin and fluorine resin. Among these, a mode in which a fluorocarbon siloxane rubber layer is provided on the surface of the belt member and a mode in which a silicone rubber layer is provided on the surface of the belt member and a fluorocarbon siloxane rubber layer is provided on the surface of the silicone rubber layer are preferable.

The fluorocarbon siloxane rubber preferably has at least one of a perfluoroalkyl ether group and a perfluoroalkyl group in the main chain.
As said fluorocarbon siloxane rubber, the hardened | cured material of the fluorocarbon siloxane rubber composition containing the following (A)-(D) component is suitable.
(A) a fluorocarbon polymer having a fluorocarbon siloxane represented by the following general formula (1) as a main component and having an aliphatic unsaturated group; (B) containing two or more ≡SiH groups in one molecule; At least one of organopolysiloxane and fluorocarbonsiloxane, wherein the content of ≡SiH group is 1 to 4 times the molar amount of the aliphatic unsaturated group in the product, (C) a filler, and (D) effective Amount of catalyst.

  The (A) component fluorocarbon polymer is mainly composed of a fluorocarbon siloxane having a repeating unit represented by the following general formula (1) and has an aliphatic unsaturated group.

In the general formula (1), R ¹⁰ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 3 carbon atoms. A methyl group is preferable, and a methyl group is particularly preferable.
a and e each represents an integer of 0 or 1; b and d each represent an integer of 1 to 4. c represents an integer of 0 to 8. Further, x is preferably 1 or more, and more preferably 10-30.

As said (A) component, what is shown by following General formula (2) can be mentioned.

  In the component (B), examples of the organopolysiloxane having an ≡SiH group include organohydrogenpolysiloxanes having at least two hydrogen atoms bonded to silicon atoms in the molecule.

  In the fluorocarbon siloxane rubber composition, when the fluorocarbon polymer of the component (A) has an aliphatic unsaturated group, it is preferable to use the above-described organohydrogenpolysiloxane as the curing agent. . That is, a cured product is formed by an addition reaction that occurs between an aliphatic unsaturated group in the fluorocarbon siloxane and a hydrogen atom bonded to a silicon atom in the organohydrogenpolysiloxane.

  As the organohydrogenpolysiloxane, various organohydrogenpolysiloxanes used in addition-curable silicone rubber compositions can be used.

  In general, the number of ≡SiH groups in the organohydrogenpolysiloxane is preferably at least one with respect to one aliphatic unsaturated hydrocarbon group in the fluorocarbon siloxane as the component (A). It is preferable to mix | blend in the ratio which becomes an individual.

Further, the fluorocarbon having an ≡SiH group includes a unit of the above general formula (1), or in the above general formula (1), R ¹⁰ is a dialkylhydrogensiloxy group, and a terminal is a dialkylhydrogensiloxy group or a silyl group. Those having a ≡SiH group such as a group are preferred, and examples thereof include those represented by the following general formula (3).

  As the filler of the component (C), various fillers used in general silicone rubber compositions can be used. Examples of the filler include fumed silica, precipitated silica, carbon powder, titanium dioxide, aluminum oxide, quartz powder, reinforcing filler such as talc, sericite, bentonite, asbestos, glass fiber, organic fiber, and the like. Examples thereof include fibrous fillers.

  Examples of the catalyst for the component (D) include chloroplatinic acid, alcohol-modified chloroplatinic acid, complexes of chloroplatinic acid and olefin, platinum black or palladium, which are known as addition reaction catalysts, alumina, silica, carbon, etc. Supported by the above-mentioned carrier, rhodium-olefin complex, chlorotris (triphenylphosphine) rhodium (Wilkinson catalyst), rhodium (III) acetylacetonate, etc. It is done. These complexes are preferably used by dissolving in a solvent such as an alcohol compound, an ether compound, or a hydrocarbon compound.

  There is no restriction | limiting in particular in the said fluorocarbon siloxane rubber composition, According to the objective, it can select suitably, A various compounding agent can be added. For example, dispersants such as diphenylsilane diol, low-molecular-degree molecular chain terminal hydroxyl-blocked dimethylpolysiloxane, hexamethyldisilazane, etc., heat resistance improvers such as ferrous oxide, ferric oxide, cerium oxide, and iron octylate Further, colorants such as pigments can be blended as necessary.

  The belt member is obtained by coating the surface of the heat-resistant support film with the fluorocarbon siloxane rubber composition, followed by heat curing. If necessary, m-xylene hexafluoride, benzotrifluoride, etc. It can be applied by a general coating method such as spray coating, dip coating and knife coating. Moreover, the temperature and time of heat-curing can be selected suitably, and it selects according to the kind of a support body film, a manufacturing method, etc. in the range of temperature 100-500 degreeC and 5 second-5 hours.

  The thickness of the release layer formed on the surface of the heat-resistant support film is not particularly limited, but is 1 to 200 μm in order to obtain good image fixability by preventing toner releasability or toner component offset. Is preferable, and 5-150 micrometers is more preferable.

Here, an example of an image forming apparatus having a typical fixing belt will be specifically described with reference to FIG.
First, the toner 12 is transferred to the electrophotographic image receiving sheet 1 by an image forming apparatus (not shown). The electrophotographic image-receiving sheet 1 with the toner 12 attached is conveyed to point A by a transport facility (not shown), passes between the heating roller 14 and the pressure roller 15, and is a toner image-receiving layer of the electrophotographic image-receiving sheet 1. Alternatively, the toner 12 is heated and pressed at a temperature (fixing temperature) and pressure at which the toner 12 is sufficiently softened.

Here, the fixing temperature means the temperature of the surface of the toner image receiving layer measured at the position of the heating roller 14, the pressure roller 15, and the nip portion at point A, and is preferably 80 to 190 ° C., for example, 100 to 170 ° C. Is more preferable. The pressure means the pressure on the surface of the toner image receiving layer measured at the heating roller 14, the pressure roller 15 and the nip portion. For example, 1 to 10 kgf / cm ² is preferable, and ² to 7 kgf / cm ² is more preferable.
The release agent (not shown) discretely present in the toner image-receiving layer while the electrophotographic image-receiving sheet 1 was heated and pressurized in this manner and then conveyed to the cooling device 16 by the fixing belt 13. ) Is sufficiently heated and melted, and moves to the surface of the toner image-receiving layer. The released release agent forms a release agent layer (film) on the surface of the toner image-receiving layer. Thereafter, the electrophotographic image-receiving sheet 1 is conveyed to the cooling device 16 by the fixing belt 13, and is, for example, below the softening point of the binder resin used for either the polymer or toner of the toner image-receiving layer or the glass transition point + 10 ° C. It is cooled to the following temperature, preferably 20 to 80 ° C., more preferably room temperature (25 ° C.). As a result, the release agent layer (film) formed on the surface of the toner image-receiving layer is cooled and solidified to form a release agent layer.
The cooled electrophotographic image-receiving sheet 1 is further conveyed to point B by the fixing belt 13, and the fixing belt 13 moves on the tension roller 17. Therefore, the electrophotographic image-receiving sheet 1 and the fixing belt 13 are peeled off at the point B. In addition, it is preferable to set the diameter of the tension roll small so that the electrophotographic image-receiving sheet is peeled off from the belt by its own rigidity (waist strength).

Further, the image surface smoothing fixing processor as shown in FIG. 3 is modified as a fixing unit of the electrophotographic apparatus shown in FIG. 2 (for example, a full color laser printer (DCC-500) manufactured by Fuji Xerox Co., Ltd.). Can be used.
In FIG. 2, 200 is an image forming apparatus, 37 is a photosensitive drum, 19 is a developing device, 31 is an intermediate transfer belt, 18 is an electrophotographic image receiving sheet, and 25 is a fixing unit (image surface smoothing fixing processing apparatus). Each is shown.
FIG. 3 shows a fixing unit (image surface smoothing fixing processing device) 25 disposed in the image forming apparatus 200 of FIG.
As shown in FIG. 3, the image surface smoothing and fixing apparatus 25 includes a heating roll 71, a peeling roll 74 including the heating roll 71, an endless belt 73 rotatably supported by a tension roll 75, A pressure roll 72 is provided in pressure contact with the heating roll 71 via an endless belt 73.
A cooling heat sink 77 for forcibly cooling the endless belt 73 is disposed between the heating roll 71 and the peeling roll 74 on the inner surface side of the endless belt 73. 77 constitutes a cooling / sheet conveying section for cooling the electrophotographic image-receiving sheet and conveying the sheet.

  In the image surface smoothing and fixing processing device 25, as shown in FIG. 3, an electrophotographic transfer sheet having a color toner image transferred and fixed on the surface thereof is heated to an endless belt 73 on the heating roll 71 and the heating roll 71. The color toner image is introduced into a pressure contact portion (nip portion) with the pressure roll 72 that is in pressure contact with the heating roll 71, and the pressure contact portion between the heat roll 71 and the pressure roll 72 is provided. During the passage, the color toner image is heated and melted and fixed on the electrophotographic image-receiving sheet.

  Thereafter, in the press-contact portion between the heating roll 71 and the pressure roll 72, for example, the toner is heated to a temperature of about 120 to 130 ° C. and melted to fix the color toner image to the image receiving layer. The photographic image-receiving sheet is conveyed together with the endless belt 73 while the image-receiving layer on the surface thereof is in close contact with the surface of the endless belt 73. In the meantime, the endless belt 73 is forcibly cooled by a cooling heat sink 77, and after the color toner image and the image receiving layer are cooled and solidified, the peeling roller 74 uses the waist (rigidity) of the electrophotographic image receiving sheet itself. It is peeled off.

  The surface of the endless belt 73 after the peeling process is completed is prepared for the next surface smoothing and fixing process by removing residual toner and the like by a cleaner (not shown).

  According to the image forming method of the present invention, even if an oilless machine without fixing oil is used, the electrophotographic image receiving sheet and toner can be prevented from being peeled off, or the electrophotographic image receiving sheet and toner component can be prevented from being offset. Paper feeding can be realized, the image quality is good, the running property is stable without causing poor running such as jamming, multi-feed conveyance, etc., and a high quality image similar to a silver halide photographic print can be formed. it can.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Examples 1 to 4, Reference Examples 1 and 2, and Comparative Examples 1 to 3)
-Production of support-
Hardwood bleached kraft pulp (LBKP) was beaten with a disc refiner to 300 ml (Canadian standard freeness, CSF) and adjusted to a weight average fiber length of 0.60 mm. Additives were added to the pulp stock at the following ratio based on the mass of the pulp.

Additive type Mass (%)
Cationic starch 1.2
Alkyl ketene dimer (AKD) 0.5
Anionic polyacrylamide 0.2
Epoxidized fatty acid amide (EFA) 0.3
Polyamide polyamine epichlorohydrin 0.3
Note) The AKD means an alkyl ketene dimer (the alkyl part is derived from a fatty acid mainly composed of behenic acid). The EFA means an epoxidized fatty acid amide (the fatty acid part is derived from a fatty acid mainly composed of behenic acid).

A base paper having an absolutely dry basis weight of 160 g / m ² was prepared from the obtained pulp paper stock by a long net paper machine. The surface of the base paper is adjusted so that the amount of alkali metal salt, alkaline earth metal salt, and polyvinyl alcohol (PVA) is as shown in Table 2 using a size press in the middle of the drying zone of the long paper machine. Size processing was performed.
Thereafter, using a machine calendar, the paper was passed so that a metal roll having a surface temperature of 110 ° C. was in contact with the surface (surface) of the base paper on which the toner image receiving layer was provided, and a calendar process was performed. The opposite surface (back surface) of the base paper was in contact with a metal roll having a surface temperature of 40 ° C. Furthermore, using a soft calender, a paper roll was passed through the base paper so that a metal roll having a surface temperature of 210 ° C. and a resin roll having a surface temperature of 40 ° C. were in contact with the back surface, and a soft calender treatment was performed . Base papers of Reference Examples 1 and 2 and Comparative Examples 1 to 3 were prepared. Table 2 shows the density and moisture content of the base paper.

On the surface of each obtained base paper, a polyethylene resin composition comprising HDPE / LDPE = 1/1 (mass ratio) containing 10% by mass of TiO ₂ was melt-extruded to the surface (surface) on which the toner image-receiving layer is provided, A polyethylene resin layer having a dry film thickness of 22 μm was formed.
On the other hand, a polyethylene resin composition composed of HDPE / LDPE = 1/1 (mass ratio) was melt-extruded on the surface (back surface) on which the toner image receiving layer was not provided to form a polyethylene resin layer having a dry film thickness of 20 μm.
Subsequently, corona discharge treatment was performed on the surface side, and gelatin was applied at 0.1 g / m ² . Also performs corona discharge treatment on the back, gelatin 0.06 g / ^{m 2,} colloidal silica 0.02 g / ^{m 2} was applied, Example 1-4, Reference Examples 1 and 2, and Comparative Examples 1 to 3 A support was prepared.

-Production of electrophotographic image-receiving sheet-
Using the obtained supports of Examples 1 to 4, Reference Examples 1 and 2, and Comparative Examples 1 to 3, electrophotographic image-receiving sheets were produced as follows.

<Preparation of coating solution for toner image-receiving layer>
-Preparation of titanium dioxide dispersion-
40.0 g of titanium dioxide (Typaque (registered trademark) A-220, manufactured by Ishihara Sangyo), 2.0 g of PVA102 (manufactured by Kuraray Co., Ltd.), and 58.0 g of ion-exchanged water are mixed together to prepare NBK-2 manufactured by Nippon Seiki Seisakusho. And dispersed to produce a titanium dioxide dispersion (titanium dioxide pigment 40% by mass).

-Preparation of coating solution for toner image-receiving layer-
15.5 g of the above titanium dioxide dispersion, 15.0 g of carnauba wax dispersion (Cerosol 524, manufactured by Chukyo Yushi Co., Ltd.), 100.0 g of polyester resin aqueous dispersion (solid content 30% by mass, KZA-7049, manufactured by Unitika) , 2.0 g of thickener (Alcox E30, manufactured by Meisei Chemical Co., Ltd.), 0.5 g of anionic surfactant (AOT), and 80 ml of ion-exchanged water were mixed and stirred to prepare a toner image-receiving layer coating solution. .
The resulting toner image-receiving layer coating solution had a viscosity of 40 mPa · s, a surface tension of 34 mN / m, and a glass transition temperature (Tg) of the polyester resin of 61 ° C.

<Preparation of coating solution for back layer>
Acrylic resin water dispersion (solid content 30% by mass, Hiloss XBH-997L, manufactured by Seiko Chemical Co., Ltd.) 100.0 g, matting agent (Tecpomer MBX-12, manufactured by Sekisui Plastics Co., Ltd.) 5.0 g, release agent ( Hydrin D337, manufactured by Chukyo Yushi Co., Ltd.) 10.0 g, thickener (CMC) 2.0 g, anionic surfactant (AOT) 0.5 g, and ion-exchanged water 80 ml are mixed, stirred, and back layer A coating solution was prepared.
The viscosity of the obtained back layer coating solution was 35 mPa · s, and the surface tension was 33 mN / m.

<Coating of Back Layer and Toner Image Receiving Layer>
The back layer coating solution was applied to the back surface of each of the obtained Examples 1 to 4, Reference Examples 1 and 2, and Comparative Examples 1 to 3 with a bar coater. Next, the toner image-receiving layer coating solution was applied to the surface of the support with a bar coater, as in the case of the back layer.
The coating amount is 9 g / m ² in terms of dry mass for the back layer, and the toner image receiving layer coating solution and the back layer coating solution are applied so that the toner image receiving layer has a dry mass of 12 g / m ^2. did. The content of the thermoplastic resin in the toner image receiving layer was 64% by mass of the total mass of the toner image receiving layer.
The back layer and the toner image-receiving layer were dried online with hot air after coating. In 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 coating. The drying point was the point at which the coating surface temperature was the same as the wet bulb temperature of the drying air.
Next, after drying, a soft calendar process was performed. The soft calendering process was performed by using a soft calender and passing the paper so that a metal roller having a surface temperature of 55 ° C. was in contact with the surface of the toner image receiving layer, and the nip pressure was 235 kN / m ² .

<Evaluation>
Each obtained electrophotographic image-receiving sheet was cut into A4, and a portrait image of a woman was used as a print image. The printer used was an image forming apparatus in which the fixing unit of the Fuji Xerox full-color laser printer (DCC-500) shown in FIG. 2 was modified to the belt-like fixing unit shown in FIG. ) Was used.
−Belt−
Belt support: polyimide (PI) film, width = 50 cm,
Thickness = 80μm
Release layer material for belt: SIFEL 610, which is a fluorocarbon siloxane rubber precursor, was vulcanized and cured to a film thickness of 50 μm.
-Cooling conditions-
Cooler: Heat sink length = 80mm
Speed: 53mm / sec

<Measurement of moisture content of base paper in electrophotographic image-receiving sheet>
The front and back surfaces of each electrophotographic image-receiving sheet were peeled off at the interface between the polyethylene resin layer and the base paper, and the obtained base paper was dried at 105 ° C. for 4 hours. It was. The results are shown in Table 3.
At the time of peeling, a base paper fiber might be slightly attached to the polyethylene resin layer, but no significant difference was observed in the amount of water.

<Running>
For each electrophotographic image-receiving sheet, a continuous print test of 50 sheets was carried out twice, and the running performance was evaluated by the number of running failures such as jamming and multi-feed conveyance during conveyance when a total of 100 sheets were printed. The results are shown in Table 3. In the present invention, a running failure of up to 1 out of 100 sheets was regarded as acceptable.

<Image quality evaluation>
Each of the obtained electrophotographic prints was visually evaluated relative to each other, and was evaluated in five stages A to E. The evaluation of image quality means that A is the best, gradually deteriorates as E approaches, and E is the worst. In addition, in this invention, it was set as the pass to B. The results are shown in Table 3.

* 1: Some unevenness in image quality due to dry crushing during calendar processing was observed.
* 2: Surface roughness due to poor stability of the liquid of PVA and CaCl ₂ was slightly observed.
From the results of Table 3, all of Examples 1 to 4 had good image quality, and no running failure occurred. On the other hand, in Comparative Examples 1 to 3, although the image quality is good, it is recognized that poor running occurs frequently.

The electrophotographic image-receiving sheet of the present invention has good image quality, has stable running performance that does not cause poor running such as jamming and multi-feed conveyance, and can be suitably used for an image forming apparatus for high-speed fixing.
According to the image forming method of the present invention, even when an oil-less machine without oil is used, the electrophotographic image receiving sheet and the toner can be prevented from being peeled off, or the electrophotographic image receiving sheet and the toner component can be prevented from being offset. Achieving paper feeding, good image quality, stable running without jamming, multi-feed conveyance, etc., and high-quality images similar to silver halide photographic prints. .

FIG. 1 is a schematic view showing an example of a fixing belt type electrophotographic apparatus of the present invention. FIG. 2 is a schematic view showing an example of the image forming apparatus of the present invention. FIG. 3 is a schematic diagram illustrating an example of an image surface smoothing fixing processor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrophotographic image receiving sheet 12 Toner 13 Fixing belt 14 Heating roller 15 Pressure roller 16 Cooling device 17 Tension roller 18 Electrophotographic image receiving sheet 25 Image surface smoothing fixing processor (fixing unit)
31 Intermediate transfer belt 71 Heating roll 72 Pressure roll 74 Peeling roll 75 Tension roll 73 Endless belt 77 Cooling heat sink 200 Image forming apparatus

Claims (13)

In an electrophotographic image-receiving sheet having a support and at least one toner image-receiving layer on the support, the support is provided with a polyolefin resin layer on both sides of the base paper, and the base paper in the support is an alkali metal It contains 0.6 to 3 g / m ² of at least one of a salt and an alkaline earth metal salt, and the water content in the base paper in the electrophotographic image-receiving sheet is 6.5 to 8.5%. An electrophotographic image-receiving sheet. At least one of the alkali metal salt and alkaline earth metal salt is at least one selected from alkali metal chlorides, carbonates and sulfates, and alkaline earth metal chlorides, carbonates and sulfates The electrophotographic image-receiving sheet according to claim 1. The base paper is 0.5-2 g / m in water-soluble polymer compound. ² The electrophotographic image-receiving sheet according to claim 1, which is contained. The electrophotographic image-receiving sheet according to claim 3, wherein the water-soluble polymer compound is at least one selected from polyvinyl alcohol, carboxy-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, cellulose sulfate, polyethylene oxide, and gelatin. The base paper is obtained by calendering after surface sizing with a surface sizing solution containing at least one of an alkali metal salt and an alkaline earth metal salt and a water-soluble polymer compound. The electrophotographic image-receiving sheet as described. The electrophotographic image-receiving sheet according to claim 5, wherein the calendering is performed using a soft calender having a metal roll having a surface temperature of 150 ° C or higher. The electrophotographic image-receiving sheet according to any one of claims 1 to 6, wherein the base paper contains at least one of an alkyl ketene dimer and an epoxidized fatty acid amide as a sizing agent. The electrophotographic image-receiving sheet according to any one of claims 1 to 7, wherein the base paper contains a pulp stock having a weight average fiber length of 0.45 to 0.70 mm. A toner image forming step for forming a toner image on the electrophotographic image-receiving sheet according to any one of claims 1 to 8, and an image surface smoothing fixing for smoothing the surface of the toner image formed by the toner image forming step An image forming method comprising a step. The image surface smoothing and fixing step heats and pressurizes the toner image using an image surface smoothing and fixing processor having a heating and pressing member, a belt member, and a cooling device, and cools and peels off the toner image. Image forming method. The image forming method according to claim 9, further comprising a fluorocarbon siloxane rubber layer on a surface of the belt member. 11. The image forming method according to claim 9, further comprising a layer made of silicone rubber on a surface of the belt member, and a layer made of fluorocarbonsiloxane rubber on the surface of the silicone rubber layer. The image forming method according to claim 11, wherein the fluorocarbon siloxane rubber has at least one of a perfluoroalkyl ether group and a perfluoroalkyl group in the main chain.