JP2003322991A - Electrophotographic image receiving sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic image receiving sheet which can form an image with high gloss, high picture quality, no crack and excellent offset resistance. <P>SOLUTION: The electrophotographic image receiving sheet has a supporting body, an image receiving layer, and an intermediate layer containing a binder having low elastic modulus and organic particles having low thermal conductivity. Such embodiments are preferable that the ratio of contents (mass ratio) of the binder having low elastic modulus and the organic particles having low thermal conductivity (binder having low elastic modulus/organic particles having low thermal conductivity) in the intermediate layer is 0.25 to 9, and the compressive elastic modulus of the binder having low elastic modulus is ≤1×10<SP>4</SP>(kg/cm<SP>2</SP>). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is particularly suitable for high gloss,
The present invention relates to an electrophotographic image-receiving sheet capable of suitably forming a full-color high-quality type image with high image quality and suppressed cracking.

[0002]

2. Description of the Related Art The electrophotographic method is an image forming method that applies a photoconductive effect and an electrostatic phenomenon, and is widely used in various fields. The image by electrophotography includes a method of forming the image on a semiconductor material itself such as zinc oxide paper and a method of transferring the image from the semiconductor material to a recording material capable of receiving a toner image. The latter method is widely used in office copying machines and the like, and the image forming principle is as follows.

First, an electrostatic charge is given to a photosensitive plate using a photoconductor such as selenium by corona discharge in a dark place, and when this is exposed corresponding to the original image, the charge changes only where it is exposed to light. Then, a latent image is formed. When the charged toner is sprinkled on the carrier and introduced therein, the toner adheres imagewise. An image is formed by applying a recording material onto the recording material, transferring the toner onto the recording material, and fixing the toner by heat or the like.

In recent years, color copiers, which have become more popular, perform the above method using colored toner.
Since the color copying machine is often used for the purpose of copying an image rather than a character, the formed image has an image quality, texture (glossiness, uniformity, etc.) similar to that of a silver salt photographic print.
Hand-held texture (thickness, waist, feel, etc.), handleability (light resistance, storage in dark place, water resistance, etc.), physical strength (adhesion resistance, scratch resistance, curl, fragility), etc. are required. Furthermore,
Along with the development of various technologies, added value higher than that of silver salt photographic prints, such as double-sided outputability and backside writing ability, is required.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art, meet various requirements, and achieve the following objects. That is, the present invention has a high gloss,
An object of the present invention is to provide an electrophotographic image-receiving sheet capable of forming an image having high image quality, no cracking, and excellent offset resistance.

[0006]

Means for solving the above-mentioned problems are as follows. That is, <1> An electrophotographic image-receiving sheet comprising a support, an image-receiving layer, and an intermediate layer containing a low elastic modulus binder and low thermal conductivity organic particles. <2> The content ratio (mass ratio) of the low elastic modulus binder and the low thermal conductivity organic particles (low elastic modulus binder / low thermal conductivity organic particles) in the intermediate layer is 2/8 to 9/1, <1. The image receiving sheet for electrophotography according to the item <>. <3> The compression elastic modulus of the low elastic modulus binder is 1 × 10
The electrophotographic image-receiving sheet according to <1> or <2>, which has a density of ⁴ (kg / cm ² ) or less. <4> The low elastic modulus binder is polyethylene, polyurethane, polybutadiene, styrene-butadiene rubber,
The electrophotographic image-receiving sheet according to any one of <1> to <3>, which is at least one of a polyacrylic ester, an epoxy resin, and a vinyl acetate-ethylene copolymer. <5> Low thermal conductivity The thermal conductivity of organic particles is 3 × 10.
^-4 (cal / sec. ° C. · cm) or less, <1
The image receiving sheet for electrophotography according to any one of <1> to <4>. <6> The electrophotographic image-receiving sheet according to any one of <1> to <5>, wherein the low thermal conductivity organic particles have a melting point of 130 ° C. or higher. <7> The electrophotographic image-receiving sheet according to any one of <1> to <6>, wherein the low thermal conductivity organic particles have a particle diameter (volume average particle diameter (D ₅₀ )) of not more than the thickness of the intermediate layer. is there. <8> The electrophotographic image-receiving sheet according to any one of <1> to <7>, wherein the low thermal conductivity organic particles are at least one of polypropylene, polystyrene, and a styrene-acrylonitrile copolymer. <9> The electrophotographic image-receiving sheet according to any one of <1> to <8>, wherein the intermediate layer has a maximum surface roughness of 7 μm or less.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The electrophotographic image-receiving sheet of the present invention has a support, an image-receiving layer, and an intermediate layer, and has other layers appropriately selected as necessary.

-Support-As the support, a support capable of withstanding the fixing temperature and satisfying the requirements in terms of smoothness, whiteness, slipperiness, friction, antistatic property, dent after fixing, etc. There is no particular limitation as long as it is, and it can be appropriately selected according to the purpose. Generally, it is generally published by Corona Publishing Co., Ltd. Year) (223)
To (240) pages, photographic supports such as synthetic polymers (films), and the like. Specific examples of the support include synthetic paper (synthetic paper such as polyolefin-based and polystyrene-based), high-quality paper, art paper, (double-sided) coated paper, (double-sided) cast coated paper, synthetic resin pulp such as polyethylene and natural. Mixed paper made from pulp, Yankee paper, baryta paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, cellulose fiber paper, polyolefin coated paper, (especially Paper support such as paper coated on both sides with polyethylene), polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene methacrylate, polyethylene naphthalate, polycarbonate polyvinyl chloride, polystyrene, polypropylene, polyimide, celluloses (eg triacetyl cellulose), Etc. Stick film or sheet, film or sheet, cloth, metal, glass, which has been subjected to a treatment for imparting white reflectivity to the plastic film or sheet (for example, treatment such as containing a pigment such as titanium oxide in the film), And so on. These may be used alone or in combination of two or more as a laminate, or may be laminated on one or both sides with a synthetic polymer such as polyethylene.

Further, as the above-mentioned support, there is further disclosed in JP-A-62-62.
Pp. 253, 159, pages (29) to (31), JP-A 1-6
1,236, pages (14) to (17), JP-A-63-31
6,848, JP-A-2-22,651, and 3-5.
Supports described in US Pat. No. 6,955, US Pat. No. 5,001,033 and the like are also included.

The thickness of the support is usually 25 to 3
00 μm, preferably 50 to 260 μm, and 75 to
220 μm is more preferable. The rigidity and smoothness of the support are not particularly limited and may be appropriately selected depending on the intended purpose, but for image-receiving papers of photographic image quality, those close to those for color silver salt photography are preferred. From the viewpoint of fixing performance, the density of the support is 0.7 g / cm.
It is preferably ³ or more.

The thermal conductivity of the support is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of fixing performance, under the conditions of 20 ° C. and 65% relative humidity, It is preferably 0.50 kcal / m · h · ° C or higher. In the present invention, the thermal conductivity is J
The transfer paper whose humidity is adjusted according to ISP 8111 can be measured by the method described in JP-A-53-66279.

Various additives appropriately selected depending on the purpose can be added to the support within a range not impairing the effects of the present invention. Examples of the additives include brighteners, conductive agents, fillers, titanium oxide, ultramarine blue, pigments such as carbon black, and dyes.

Further, one or both surfaces of the support are preferably subjected to various surface treatments or an undercoat layer is formed for the purpose of improving the adhesion with the layer provided thereon. Examples of the surface treatment include a glossy surface, a fine surface described in JP-A-55-26507, a matte surface, or a matte surface, a corona discharge treatment, a flame treatment, a glow discharge treatment, a plasma treatment, and the like. Activation treatment, etc. The undercoat layer is, for example, JP-A-61 / 61.
The method described in JP-A-846443 may be mentioned. These treatments / layer formations may be carried out independently, or may be subjected to the activation treatment after the above-mentioned patterning treatment, or the undercoat layer after surface treatment such as the activation treatment. May be applied and they can be arbitrarily combined.

In the support, on the front surface or the back surface of the support, or a combination thereof, a hydrophilic binder and a semiconductive metal oxide such as alumina sol or tin oxide;
You may apply carbon black and other antistatic agents. Specific examples of such a support include Japanese Patent Laid-Open No.
Examples of the support include those described in 3-220,246.

-Image Receiving Layer- The image receiving layer is a layer on which an image is formed by receiving at least one of color toner and black toner. The material for the image receiving layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, in the transfer step, an image is formed from a developing drum or an intermediate transfer member by (static) electricity, pressure, or the like. Examples thereof include an image-receiving substance that can accept toner and can be fixed by heat, pressure, etc. in the fixing step. Examples of the receptive substance include solvent-based thermoplastic resins, water-based thermoplastic resins, pigments and dyes.

The thickness of the image receiving layer is preferably 1/2 or more of the particle size of the toner, and more preferably 1 to 3 times the particle size of the toner. Examples of the image receiving layer include, for example, JP-A-5-216322 and 7-3019.
Those having a thickness disclosed in No. 39 or the like are preferable.

As the physical properties of the image-receiving layer, those satisfying at least one of the following items are preferable, those satisfying at least two items are more preferable, and those satisfying all the items are particularly preferable. The physical properties include Tg (glass transition temperature) of the image receiving layer of 30 ° C. or higher and Tg of the toner + 20 ° C. or lower, and T1 / 2 (1/2 method softening point) of the image receiving layer.
Is in the range of 60 ° C. to 200 ° C., preferably 80 to 170 ° C., and Tfb (outflow start temperature) of the image receiving layer is 40.
C. to 200.degree. C., more preferably Tfb of the image receiving layer is Tfb + 50.degree. C. or less of the toner, and the viscosity of the image receiving layer is 1.
The temperature at which it becomes × 10 ⁵ CP is 40 ° C. or higher, lower than that of the toner, the storage elastic modulus (G ′) at the fixing temperature of the image receiving layer is 1 × 10 ² Pa to 1 × 10 ⁵ Pa, and the loss elastic modulus ( G ″) is 1 × 10 ² Pa to 1 × 10 ⁵ Pa, and a loss tangent (G ″) which is a ratio of the loss elastic modulus (G ″) and the storage elastic modulus (G ′) at the fixing temperature of the image receiving layer. / G ') is 0.01 to 10, and the storage elastic modulus (G') at the fixing temperature of the image receiving layer is -50 to +25 with respect to the storage elastic modulus (G ") at the fixing temperature of the toner.
00, the inclination angle of the molten toner on the image receiving layer is 5
It is 0 degrees or less, preferably 40 degrees or less.

As the image receiving layer, Japanese Patent No. 278835 is used.
No. 8, JP-A Nos. 7-248637 and 8-305067.
No. 10-239889, etc. are preferred.

The above physical properties can be measured by a differential scanning calorimeter (DSC). The above physical properties are, for example, the flow tester CFT- manufactured by Shimadzu Corporation.
It can be measured using 500. The above physical properties can be measured by using a rotary rheometer (for example, dynamic analyzer RADII manufactured by Rheometric Co.). The above physical properties are measured by using a contact angle measuring device manufactured by Kyowa Interface Science Co., Ltd.
Good measurement can be performed by the method disclosed in Japanese Patent No.

--Solvent-Type Thermoplastic Resin-- The solvent-type thermoplastic resin is not particularly limited as long as it is deformable under temperature conditions such as fixing and can receive the toner, It can be appropriately selected depending on the case, but a resin similar to the binder resin of the toner is preferable. Since many of the toners use a polyester resin, styrene, or a copolymer resin such as styrene-butyl acrylate, in this case, as the thermoplastic resin used in the electrophotographic image-receiving sheet, the polyester resin, styrene, or styrene is also used. -It is preferable to use a copolymer resin such as butyl acrylate, and it is more preferable to contain a copolymer resin such as a polyester resin or styrene or styrene-butyl acrylate in an amount of 20% by mass or more. Coalescence, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, etc. are also preferable.

Specific examples of the solvent-based thermoplastic resin include (a) a resin having an ester bond, (b)
Polyurethane resin, etc. (c) Polyamide resin, etc. d) Polysulfone resin, etc., (e) Polyvinyl chloride resin, etc.
(F) Polyvinyl butyral, etc., (to) polycaprolactone resin, etc., (h) polyolefin resin, etc. may be mentioned.

Examples of the resin having an ester bond (a) include terephthalic acid, isophthalic acid, maleic acid, fumaric acid, phthalic acid, adipic acid, sebacic acid, azelaic acid, abietic acid, succinic acid, trimellitic acid. , Dicarboxylic acid components such as pyromellitic acid (these dicarboxylic acid components may be substituted with sulfonic acid groups, carboxyl groups, etc.), and ethylene glycol, diethylene glycol, propylene glycol, bisphenol A, and diether derivatives of bisphenol A (For example,
Bisphenol A ethylene oxide 2 adduct, bisphenol A propylene oxide 2 adduct, etc.),
Polyester resin obtained by condensation with an alcohol component such as bisphenol S, 2-ethylcyclohexyldimethanol, neopentyl glycol, cyclohexyldimethanol, or glycerin (these alcohol components may be substituted with a hydroxyl group), poly Polyacrylic acid ester resin or polymethacrylic acid ester resin such as methyl methacrylate, polybutyl methacrylate, polymethyl acrylate, polybutyl acrylate,
Polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, styrene-methacrylic acid ester copolymer resin, vinyl toluene acrylate resin and the like. Specifically, JP-A-59-101395 and 63-7971.
63, 7973, 63-7973, 60
Those described in No. 294862 and the like can be mentioned. As commercially available products of the polyester resin, Toyon Byron 290, Byron 200, Byron 280, Byron 300, Byron 103, Byron GK-140, Byron GK-130, Kao's Tuffton NE-382, Tuffton U-5, ATR-2009, ATR-2010,
Unitika's Elitel UE3500, UE3210,
XA-8153, Polyester TP- manufactured by Nippon Synthetic Chemical Industry
220, R-188, etc., and as the commercially available product of the acrylic resin, DIANAL S manufactured by Mitsubishi Rayon Co., Ltd.
E-5437, SE-5102, SE-5377, SE
-5649, SE-5466, SE-5482, HR-
169, 124, HR-1127, HR-116, HR
-113, HR-148, HR-131, HR-47
0, HR-634, HR-606, HR-607, LR
-1065, 574, 143, 396, 637, 16
2, 469, 216, BR-50, BR-52, BR-
60, BR-64, BR-73, BR-75, BR-7
7, BR-79, BR-80, BR-83, BR-8
5, BR-87, BR-88, BR-90, BR-9
3, BR-95, BR-100, BR-101, BR-
102, BR-105, BR-106, BR-107,
BR-108, BR-112, BR-113, BR-1
15, BR-116, BR-117, Sekisui Chemical Co., Ltd. S-REC P SE-0020, SE-0040, SE-
0070, SE-0100, SE-1010, SE-1
035, Sanyo Chemical Industries Himer ST95, ST120,
FM601 and the like manufactured by Mitsui Chemicals are listed.

Examples of the above (e) polyvinyl chloride resin and the like further include polyvinylidene chloride resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl propionate copolymer resin, and the like. Examples of the (f) polyvinyl butyral and the like include polyol resins, ethyl cellulose resins, cellulose resins such as cellulose acetate resins, and the like, and commercially available products include those manufactured by Denki Kagaku Kogyo Co., Ltd.,
Sekisui Chemical Co., Ltd. etc. are mentioned. The polyvinyl butyral has a polyvinyl butyral content of 70% by mass.
As described above, those having an average degree of polymerization of 500 or more are preferable, those having an average degree of polymerization of 1000 or more are more preferable, and commercially available products are Denka Butyral 3000- manufactured by Denki Kagaku Kogyo Co., Ltd.
1, 4000-2, 5000A, 6000C, Sekisui Chemical Co., Ltd. S-REC BL-1, BL-2, BL-3, B
L-S, BX-L, BM-1, BM-2, BM-5, B
MS, BH-3, BX-1, BX-7, etc. are mentioned. Examples of the (to) polycaprolactone resin and the like further include styrene-maleic anhydride resin, polyacrylonitrile resin, polyether resin, epoxy resin, and phenol resin. Examples of the (h) polyolefin resin and the like include polyethylene resin, polypropylene resin and the like, copolymer resins of olefins such as ethylene and propylene and other vinyl monomers, acrylic resins and the like.

The above thermoplastic resins may be used alone or in combination of two or more, and in addition to these, a mixture thereof, a copolymer thereof or the like may be used.

As the thermoplastic resin, those which can satisfy the above-mentioned physical properties of the image-receiving layer in the state where the above-mentioned image-receiving layer is formed are preferable, and those which alone can satisfy the above-mentioned physical properties of the image-receiving layer are more preferable, and the above-mentioned image-receiving layer is preferable. 2 resins with different physical properties
It is also preferable to use the above together.

The thermoplastic resin preferably has a larger molecular weight than the thermoplastic resin used in the toner. However, depending on the relationship between the thermodynamic characteristics of the thermoplastic resin used in the toner and the resin used in the image receiving layer, the above-mentioned molecular weight is not always preferable. For example, when the softening temperature of the resin used in the image receiving layer is higher than that of the thermoplastic resin used in the toner, the molecular weight is the same,
In some cases, it is preferable that the resin used in the image receiving layer is smaller. As the thermoplastic resin, it is also preferable to use a mixture of resins having the same composition but different average molecular weights. Further, regarding the relationship with the molecular weight of the thermoplastic resin used in the toner, Japanese Patent Application Laid-Open No. 8-3
The relationship disclosed in 34915 is preferred. The molecular weight distribution of the thermoplastic resin is preferably wider than that of the thermoplastic resin used in the toner. As the thermoplastic resin, Japanese Patent Publication No. 127
No. 413, No. 8-194394, No. 8-334915.
No. 8, No. 8-334916, No. 9-171265, No. 1
Those satisfying the physical properties disclosed in 0-221877 and the like are preferable.

--Aqueous Thermoplastic Resin-- As the aqueous thermoplastic resin, if it is a water-soluble resin or a water-dispersible resin, its composition, bond structure, molecular structure, molecular weight, molecular weight distribution, morphology, etc. are particularly limited. However, it may be appropriately selected depending on the purpose, and examples thereof include those having a water-solubilizing group of the polymer. Examples of the water-solubilizing 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.

Examples of the water-based thermoplastic resin include:
26 of Research Disclosure 17, 643
Page, No. 18,716, Page 651, No. 307,105, 8
73-874 and JP-A-64-13546 ((7)
1) to (75), specifically, for example, vinylpyrrolidone-vinyl acetate copolymer, styrene-vinylpyrrolidone copolymer, styrene-
Maleic anhydride copolymer, water-soluble polyester, water-soluble polyurethane, water-soluble nylon, water-soluble epoxy resin,
And so on.

As the water-dispersible resin, when the binder resin of the toner is a polyester resin or the like, water-dispersible polyesters or the like can be preferably used as the resin of the image receiving layer.

Other examples of the water-dispersible resin include water-dispersible resins such as water-dispersed acrylic resin, water-dispersed polyester resin, water-dispersed polystyrene resin, and water-dispersed urethane resin;
Acrylic resin emulsions, polyvinyl acetate emulsions, emulsions such as SBR (styrene-butadiene-rubber) emulsions, resins and emulsions in which the thermoplastic resin is dispersed in water, or copolymers, mixtures, cation-modified products thereof, etc. Can be mentioned. These may be used alone or in combination of two or more.

Commercially available water-dispersible resins include, for example, Vylonal MD-1200 and MD-12 manufactured by Toyobo.
20, MD-1930 and Pluscoat Z- manufactured by Mutual Chemical
446, Z-465, RZ-96, ES manufactured by Dainippon Ink
-611, ES-670, pine resin A-1 made by Takamatsu Yushi Co., Ltd.
60P, A-210, A-620, Hyros XE-18, XE-35, XE-48, XE-6 manufactured by Seikou Kagaku Kogyo
0, XE-62, AW-36H, BH-997H, F-
3171L, KE-1148, Jurimer A manufactured by Nippon Pure Chemical Co., Ltd.
T-210, AT-510, AT-515, AT-61
3, ET-410, ET-530, ET-533, FC
-60, FC-80, Unitika Elitel KZA-7
049, KZA-1449, KZA-5034 and the like.

The film forming temperature of the water-based thermoplastic water-soluble resin is preferably room temperature or higher for storage before printing and 100 ° C. or lower for fixing toner particles.

--Pigment / Dye-- The pigment is for the purpose of imparting whiteness, adjusting the thermodynamic properties of the film, or imparting receptivity to water-soluble inks, inks for ink jet printing and the like like toners. so,
It can be used as a toner image receiving material. For example, fluorescent whitening agents, white pigments, colored pigments and the like can be mentioned. The fluorescent whitening agent has absorption in the near-ultraviolet region and is 400 to 500 n.
A known compound is used as a compound that fluoresces in m.
Examples of the optical brightener include K.I. VeenRataram
an edited by "The Chemistry of Synt"
compounds described in Chapter 8 of the volume of "Hetic Dyes", more specifically, stilbene compounds,
Examples thereof include coumarin compounds, biphenyl compounds, benzoxazoline compounds, naphthalimide compounds, pyrazoline compounds, carbostyryl compounds, and the like. Examples of these are white full fur PSN, PHR, HCS, PCS, B, Ciba-G manufactured by Sumitomo Chemical.
UVITEX-OB manufactured by eigy and the like can be mentioned.

As the above-mentioned colored pigment, there is disclosed in JP-A-63-44.
Various pigments and azo pigments described in Japanese Patent No. 653 (azo lake; carmine 6B, red 2B, insoluble azo; monoazo yellow, disazo yellow, pyrazolo orange, vulcan orange, condensed azo type; chromophtal yellow, chromophthal red), Polycyclic pigments (phthalocyanine type; copper phthalocyanine blue, copper phthalocyanine green, cioxazine type; dioxazine violet, isoindolinone type; isoindolinone yellow, slene type; perylene, perinone, flavantron, thioindigo, lake pigment (malachite green) , Rhodamine B,
Rhodamine G, Victoria Blue B) or inorganic pigments (oxides, titanium dioxide, red iron oxide, sulfates; precipitated barium sulfate, carbonates; precipitated calcium carbonate, silicates; hydrous silicates, anhydrous silicates, metals Powder: Aluminum powder, bronze powder, zinc dust, carbon black, yellow lead, navy blue, and the like.

As the pigment, an inorganic pigment is particularly preferable. Examples of the inorganic pigment include silica pigment, alumina pigment, titanium dioxide pigment, zinc oxide pigment, zirconium oxide pigment, mica-like iron oxide, lead white, lead oxide pigment, cobalt oxide pigment, strontium chromate, molybdenum pigment, and smectite. , Magnesium oxide pigment, calcium oxide pigment, calcium carbonate pigment, mullite and the like. Among these, silica pigments and alumina pigments are preferable, and these may be used alone or in combination with 2
You may use together 1 or more types.

Examples of the silica pigment include spherical silica and amorphous silica. The silica pigment is a dry method,
It can be synthesized by a wet method or an airgel method. The surface of the hydrophobic silica particles may be surface-treated with a trimethylsilyl group or silicone. Among these, colloidal silica is particularly preferable.

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

As the dye, various known dyes can be used, and examples thereof include oil-soluble dyes. Examples of the oil-soluble dyes include anthraquinone compounds and azo compounds. Specific examples of the oil-soluble dye include C.I. I. Vat Violet 1,
C. I. Vat Violet 2, C.I. I. Vat Violet 9, C.I. I. Vat Violet 13,
C. I. Vat Violet 21, C.I. I. Vat Blue 1, C.I. I. Vat Blue 3, C.I. I. Vat Blue 4, C.I. I. Vat Blue 6, C.I. I. Vat Blue 14, C.I. I. Vat Blue 20, C.I. I. Vat blue 35 and other vat dyes, C.I. I. Disperse Violet 1, C.I. I. Disperse Violet 4, C.I.
I. Disperse Violet 10, C.I. I. Disperse Blue 3, C.I. I. Disperse Blue 7, C.I.
I. Disperse dyes such as Disperse Blue 58, C.I. I. Solvent Violet 13, C.I. I. Solvent Violet 14, C.I. I. Solvent Violet 2
1, C.I. I. Solvent Violet 27, C.I. I.
Solvent Blue 11, C.I. I. Solvent Blue 1
2, C.I. I. Solvent Blue 25, C.I. I. Solvent Blue 55, etc. may be mentioned. Further, colored couplers used in silver salt photography are also preferred.

The image-receiving layer may contain an appropriately selected additive for the purpose of improving its thermodynamic properties.
The additive is not particularly limited and may be appropriately selected depending on the intended purpose, and examples thereof include a plasticizer, a filler, a cross-linking agent, a charge control agent, a conductive agent, a surfactant, a humidity control agent, and a matting agent. , And the like.

As the plasticizer, known plasticizers for resins can be used. The term "plasticizer" as used herein refers to a group of compounds that adjust the fluidity or softening of the image-receiving layer by heat and / or pressure when fixing the toner. Specific examples of the plasticizer include "Chemical Handbook" (edited by The Chemical Society of Japan, Maruzen) and "Plasticizer-Theory and Application-".
(Edited by Koichi Murai, Kou Shobo) and "Study on Plasticizers"
It can be selected by referring to "Under Research on Plasticizers" (edited by Japan Society of Polymer Chemistry) and "Handbook Rubber / Plastic Blended Chemicals" (edited by Rubber Digest Co.), etc., and JP-A-59-83154. , Ibid. 59-178451, ibid. 5
9-178453, 59-178454, 59
-178455, 59-178457, 62-
No. 174754, No. 62-245253, No. 61-2
09444, 61-200538, 62-81.
No. 45, No. 62-9348, No. 62-30247,
62-136646, 62-174754, 62-245253, 61-209444, 6
1-250038, 62-8145, 62-9
No. 348, No. 62-30247, No. 62-13664
6, esters such as those described in JP-A-2-235694 (for example, phthalic acid esters, phosphoric acid esters, fatty acid esters, abietic acid esters, adipic acid esters, sebacic acid esters, Azelaic acid ester, benzoic acid ester, butyric acid ester, epoxidized fatty acid ester, glycolic acid ester, propionic acid ester, trimellitic acid ester, citric acid ester, sulfonic acid ester, carboxylic acid ester , Succinic acid esters, maleic acid esters, fumaric acid esters, phthalic acid esters, stearic acid esters, etc.), amides (eg fatty acid amides, sulfamides, etc.), ethers, alcohols, paraffins, Polyolefin waxes (eg polyp Pyrene waxes, polyethylene waxes, etc.), lactones, polyethyleneoxy, silicone oils, fluorine compounds include compounds such as.

The plasticizer may have a relatively low molecular weight. In this case, the molecular weight is preferably lower than that of the resin to be plasticized, and the molecular weight is preferably 15,000 or less. More preferably, those having a molecular weight of 8,000 or less are particularly preferable. As the plasticizer, a polymer plasticizer may be used, in which case it is preferably a polymer of the same type as the resin to be plasticized, for example, polyester is preferable for plasticizing the polyester resin, and, Oligomers may be used as plasticizers.

As the plasticizer, other than the above-mentioned ones, for example, commercially available products such as ADEKA CIZER PN-170 and PN-1430 manufactured by Asahi Denka Kogyo Co., Ltd. and C.I. P. Hall
Company products PARAPLEX-G-25, G-30, G-4
0, Rika Hercules product ester gum 8L-JA, ester R-95, pentaline 4851, FK115, 4
820, 830, Louisol 28-JA, Picolastic A75, Picotex LC, Crystallex 308
5, etc.

The plasticizer is formed on the support,
It is added to at least one of the constituent layers including the image receiving layer, for example, a protective layer, an intermediate layer, an undercoat layer, etc. As these layers, a layer to which stress generated when the toner is embedded in the image receiving layer is transmitted. Is preferable, and a layer in which strain caused by stress (physical strain such as elastic force and viscosity, strain due to material balance of molecules, binder main chain, pendant portion, etc.) is transmitted is more preferable. A layer at a position where the stress and strain can be relaxed, such as a layer adjacent to the image receiving layer, the image receiving layer, or a surface layer is particularly preferable. The plasticizer, in the added layer,
It may be in a state of being dispersed in a micro state, in a state of being phase-separated into a sea-island micro state, or in a state of being sufficiently mixed and dissolved with another component such as a binder.

The amount of the plasticizer added is 100 when the total amount of the resin constituting the layer, other components and the plasticizer is added.
When it is defined as mass%, 0.001 mass% to 200 mass% is preferable, 0.1 mass% to 100 mass% is more preferable,
Particularly, 1% by mass to 50% by mass is particularly preferable. Adjusting the plasticizer for slipperiness (improving transportability by reducing frictional force),
It may be used for the purpose of improving the offset of the fixing portion (peeling of the toner or layer to the fixing portion), adjusting the curl balance, adjusting the charge (forming the toner electrostatic image), and the like.

As the filler, a reinforcing agent for resin,
Known fillers and reinforcing materials can be used,
Organic and inorganic fillers are preferred. The filler should be selected by referring to "Handbook Rubber / Plastic Compounding Chemicals" (edited by Rubber Digest), "New Edition Plastic Compounding Agents Basics and Applications" (Taisei), "Filler Handbook" (Taisei), etc. You can As the filler, for example, the above-mentioned various inorganic pigments can be used, and the inorganic pigments include titanium oxide, calcium carbonate, silica, talc, mica, alumina, and other "handbook rubber / plastic compounding chemicals" (rubber Known examples are described in "Digest Co., Ltd.).

Examples of the cross-linking agent include compounds having two or more reactive groups in the molecule as reactive groups, such as epoxy group, isocyanate group, aldehyde group, active halogen group, active methylene group, acetylene group, and the like. Further, 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 is also included. Examples of the crosslinking agent also include known compounds such as coupling agents for resins, curing agents, polymerization agents, polymerization accelerators, coagulants, film-forming agents, film-forming assistants, and the like. Examples of the coupling agent include chlorosilanes, vinylsilanes, epoxysilanes, aminosilanes, alkoxyaluminum chelates, titanate coupling agents, and the like, "Handbook Rubber / Plastic Compounding Chemicals" (edited by Rubber Digest) And the like.

The charge control agent can be used for the purpose of adjusting transfer and adhesion of toner, preventing charge adhesion of the electrophotographic image receiving sheet, and the like. As the charge control agent, any of conventionally known antistatic agents and charge control agents can be used, and surface active agents such as cationic surfactants, anionic surfactants, amphoteric surfactants and nonionic surfactants can be used. In addition to agents and the like, polymer electrolytes, conductive metal oxides and the like can be used. Examples of the charge control agent include quaternary ammonium salts, polyamine derivatives, cation-modified polymethylmethacrylate, cation-modified polystyrene and other cationic antistatic agents, alkyl phosphates, anionic polymers and other anionic antistatic agents, and fatty acids. ester,
Examples thereof include nonionic antistatic agents such as polyethylene oxide, but are not limited thereto. When the toner has a negative charge, the charge control agent is preferably a cation or nonion.

As the conductive agent, ZnO, TiO ₂ ,
SnO ₂ , Al ₂ O ₃ In ₂ O ₃ , SiO ₂ , Mg
Examples thereof include metal oxides such as O, BaO, and MoO ₃ . These may be used alone or in combination of two or more. In addition, the metal oxide may further contain a different element, for example, ZnO with respect to A
l, In, etc., TiO ₂ , Nb, Ta, etc., SnO ₂
In contrast, Sb, Nb, a halogen element and the like can be contained (doped).

-Intermediate Layer- The intermediate layer contains a low elastic modulus binder and low thermal conductivity organic particles, and optionally other components.

The low elastic modulus binder is preferably a binder having a low elastic modulus, such as polyurethane,
Polybutadiene, styrene-butadiene rubber, styrene-methyl methacrylate copolymer, polypropylene, polyethylene, polybutylene, polyurethane, polyacrylic ester, epoxy resin, vinyl acetate-ethylene copolymer and the like are preferable. These may be used alone or in combination of two or more. Among these, styrene-butadiene rubber (0.025 to 8.4 × 10 ⁴ (kg / cm ² )) and polyurethane (0.07 to 0.7 × 10 ⁴ (kg / c
m ² )), polybutylene (0.218 × 10 ⁴ (kg /
cm ² )) and polyethylene (0.35 to 1.05)
× 10 ⁴ (kg / cm ² )) and the like are preferable. They are,
They may be used alone or in combination of two or more.

The compression elastic modulus of the low elastic modulus binder is preferably 1 × 10 ⁴ (kg / cm ² ) or less, more preferably 0.8 × 10 ⁴ (kg / cm ² ) or less. In the present invention, an image in which cracking is suppressed is formed by using such a low elastic modulus polymer having a stress relaxation effect. The compression modulus is 1 × 10
^When it exceeds ⁴ (kg / cm ² ), the glossiness of the formed image is lowered and cracking may occur. The compressive elastic modulus is a value measured according to ASTM D695.

The thermal conductivity of the low thermal conductivity organic particles is preferably 3 × 10 ⁻⁴ (cal / sec. ° C. · cm) or less, and 2.8 × 10 ⁻⁴ (cal / sec. ° C. · c).
m) or less is more preferable. The thermal conductivity is 3 × 10
^If it exceeds ⁻⁴ (cal / sec. ° C. · cm), the glossiness of the formed image may decrease.

As the melting point of the low thermal conductivity organic particles,
130 degreeC or more is preferable and 150 degreeC or more is more preferable. When the melting point is lower than 130 ° C., the glossiness of the formed image may decrease.

As the material of the low thermal conductivity organic particles,
Examples thereof include polypropylene, polystyrene, and styrene-acrylonitrile copolymer. These may be used alone or in combination of two or more.

The particle size of the low thermal conductivity organic particles is preferably not more than the thickness of the intermediate layer, and specifically, the volume average particle size (D ₅₀ ) is preferably 0.1 to 20 μm. If the particle size is larger than the thickness of the intermediate layer, the surface roughness tends to decrease, and the glossiness of the image formed tends to decrease.

In the intermediate layer, the content ratio (mass ratio) of the low elastic modulus binder and the low thermal conductivity organic particles (low elastic modulus binder / low thermal conductivity organic particles) is 0.
25-9 are preferable and 0.4-4 are more preferable. The content ratio (low elastic modulus binder / low thermal conductivity organic particles)
However, if the content is 0.25, the formation of the intermediate layer may become difficult or brittle, while if the content ratio (low elastic modulus binder / low thermal conductivity organic particles) exceeds 9, it is formed. The glossiness of the formed image may decrease.

As the arithmetic average roughness of the intermediate layer, the maximum surface roughness is preferably 7 μm or less, more preferably 5 μm or less. When the arithmetic average roughness exceeds 7 μm, the glossiness of the formed image may be lowered. In the present invention, the roughness of the surface of the image receiving layer can be reduced by providing such an intermediate layer having a smooth surface and laminating the image receiving layer or the like on the intermediate layer. Incidentally, the arithmetic mean roughness is JIS B 0
It is the value measured according to 601.

The intermediate layer preferably has a high solvent barrier property. Here, the "solvent barrier property" refers to a property in which there is substantially no strike-through of the solvent when the intermediate layer is wet with a 1/1 mixed solution of toluene and methyl ethyl ketone. When the solvent barrier property is low, the solvent reaches the paper support through the intermediate layer when the image-receiving layer is formed by coating.
The flatness of the paper support is reduced. For this reason, the flatness of the image-receiving layer applied thereon may be lowered, and the glossiness may be lowered.

The thickness of the intermediate layer is 0.5 to 30 μm.
Is preferable, and 2-20 micrometers is more preferable. If the thickness is less than 0.5 μm, the glossiness of the formed image may be lowered and cracks may occur, while the thickness is 30 μm.
If it exceeds, the adhesion resistance may be lowered and fixing offset may occur.

—Other Layers— Examples of the other layers include, for example, a surface protective layer (overcoat layer), undercoat layer, cushion layer, charge control (prevention) layer,
Examples thereof include a reflective layer, a tint adjusting layer, a storability improving layer, an anti-adhesion layer, an anti-curl layer, a smoothing layer, a back coat layer, a moisture impermeable layer and an adhesion improving layer. Each of these layers may have a single-layer structure or a laminated structure.

The surface protective layer of the image-receiving layer is used for the purpose of protecting the surface, improving storage stability, improving handleability, imparting writability, improving device passage, and imparting offset resistance. It is preferably provided on the surface. The surface protective layer is
It may be one layer or two or more layers. Various thermoplastic resins, thermosetting resins, water-soluble polymers and the like can be used as the binder in the surface protective layer, and preferably the same kind as the image receiving layer is used.
However, thermodynamic characteristics, electrostatic characteristics, etc. do not have to be the same as those of the image receiving layer, and are optimized.

Any additive that can be used in the image receiving layer can be used in the surface protective layer, and a charge control agent, a matting agent, a slipping agent, a releasing agent, etc. are preferably used. In addition, these may be used in addition to the protective layer.

The outermost surface layer of the electrophotographic image-receiving sheet, such as the surface protective layer, preferably has good compatibility with the toner from the viewpoint of fixing property, and specifically, the contact angle with the melted toner. Is preferably 40 degrees or less and 0 degrees or more.

The matting agent is not particularly limited,
It can be appropriately selected depending on the purpose, and examples thereof include solid particles. The solid particles can be classified into inorganic particles and organic particles. Examples of the inorganic particles include oxides (eg, silicon dioxide, titanium oxide, magnesium oxide, aluminum oxide), alkaline earth metal salts (eg, barium sulfate, calcium carbonate, magnesium sulfate), silver halides (eg, Examples thereof include silver chloride, silver bromide) and glass.

Examples of the inorganic particles include West German Patent 2529.
No. 321, British Patent Nos. 760775 and 1260772.
U.S. Pat. Nos. 1,201,905 and 2,192,241.
No. 3053662, No. 3062649, No. 3257
No. 206, No. 3322555, No. 3353958,
3370951, 3411907 and 3437.
No. 484, No. 35223022, No. 3615554,
No. 3635714, No. 3769020, No. 4021
And the like described in the respective specifications of No. 245 and No. 4029504.

Examples of the organic particles include starch, cellulose ester (eg, cellulose acetate propionate), cellulose ether (eg, ethyl cellulose), synthetic resin and the like. The synthetic resin is preferably a water-insoluble or sparingly water-soluble synthetic resin. Examples of the water-insoluble or sparingly water-soluble synthetic resin include poly (meth) acrylic acid ester (for example, polyalkyl (meth) acrylate, polyalkoxyalkyl (meth) acrylate, polyglycidyl (meth) acrylate), poly (meth) acrylamide. , Polyvinyl ester (for example, polyvinyl acetate), polyacrylonitrile, polyolefin (for example, polyethylene), polystyrene, benzoguanamine resin, formaldehyde condensation polymer, epoxy resin, polyamide, polycarbonate, phenol resin, polyvinylcarbazole, polyvinylidene chloride, etc. . The synthetic resin may be a copolymer in which repeating units of these polymers are combined. The copolymer may contain a small amount of hydrophilic repeating units. Examples of the monomer forming the hydrophilic repeating unit include acrylic acid, methacrylic acid, α, β-unsaturated dicarboxylic acid, hydroxyalkyl (meth) acrylate, sulfoalkyl (meth) acrylate, styrenesulfonic acid,
And so on. As the organic particles, British Patent 1
055713, U.S. Pat. Nos. 1,939,213 and 222.
No. 1873, No. 2268662, No. 2322037
No. 23706005, 2391181, 27
01245, 2929101, and 3079257.
No. 3,262,782, No. 3443946, No. 35
No. 16832, No. 3539344, No. 3591379
Nos. 3754924 and 3767448, JP-A-49-106821 and 57-14835.
Those described in each publication of the issue are listed. The solid particles may be used alone or in combination of two or more. The average particle size of the solid particles is 1 to 10
0 μm is preferable, and 4 to 30 μm is more preferable. The amount of the solid particles used is 0.01 to 0.5 g / m ^2.
Is preferable and 0.02-0.3 g / m < ² > is more preferable.

As the above-mentioned slipping agent, various known ones can be mentioned, such as higher alkyl sodium sulfate, higher fatty acid higher alcohol ester, carbowax, higher alkyl phosphate ester, silicone compound, modified silicone,
Curable silicone and the like, and polyolefin wax, fluorine-based oil, fluorine-based wax, carnauba wax, microcrystalline wax, silane compound and the like can be mentioned.

Examples of the slip agent include, for example, US Pat.
882157, 312160, 385064
No. 0, French patent 2180465, British patent 955
No. 061, No. 1143118, No. 1263722,
No. 1270578, No. 1320564, No. 1320
No. 757, No. 2588765, No. 2739891,
No. 3018178, No. 3042522, No. 3080
No. 317, No. 3082087, No. 3121060,
No. 3222178, No. 3295979, No. 3489
No. 567, No. 3516832, No. 3658573,
Nos. 3679411 and 3870521,
JP-A-49-5017, JP-A-51-141623, JP-A-54-159221, and JP-A-56-81841, and Research Disclosure (Research).
ch Disclosure) 13969 and the like.

The amount of the slipping agent used is 5 to 500.
Preferably ^{mg / m 2, 10~200mg / m} 2 is more preferable. Further, in the case of so-called oilless fixing which does not use oil for the purpose of preventing offset to the fixing member in the fixing unit, 30 to 3000 mg / m ² is preferable, and 1
More preferably, it is 00 to 1500 mg / m ² . Of the above-mentioned slipping agents, wax-type ones are difficult to dissolve in an organic solvent, so it is preferable to prepare an aqueous dispersion and a dispersion with a thermoplastic resin solution and apply the dispersion. In this case, the wax lubricant is present in the thermoplastic resin in the form of fine particles. In this case, the amount of the slip agent used is 5 to 10,000 m.
g / m ² is preferable, and 50 to 5000 mg / m ² is more preferable.

The back coat layer sandwiches the support for the purpose of imparting back surface output suitability, improving back surface output image quality, curl balance, writing property, ink jet and other print aptitude, and device passing property. It is provided on the opposite side of the image receiving layer. The image receiving sheet for electrophotography,
In the case of a transmissive type, the back coat layer is also preferably transparent, and in the case of a reflective type, the back layer does not need to be transparent and may have any color, and an image may be formed on the back surface. In the case of a double-sided output type to be formed, the back layer is also preferably white. In this case, it is preferable that the whiteness and the spectral reflectance of the back surface are 85% or more, as in the case of the front surface. The back coat layer may have the same structure as the image receiving layer side in order to improve double-sided output suitability. The above-mentioned various additives can be used in the back coat layer, and it is particularly preferable to use the above-mentioned matting agent, slip agent, charge control agent and the like. The back coat layer is
It may be one layer or two or more layers. Further, when releasing oil is used for the fixing roller or the like to prevent offset at the time of fixing, it is preferable that the back surface have oil absorbability.

The adhesion improving layer can be appropriately provided for the purpose of improving the adhesion between the support, the image receiving layer and the other layers. The above-mentioned various additives can be used in the adhesion improving layer, and the above-mentioned crosslinking agent can be preferably used. The cushion layer is appropriately provided in order to improve the toner receptivity. The moisture impermeable layer is appropriately provided for the purpose of reducing the environmental humidity dependency in the storage state before output, the print state during output and the print state after output.

<Other Additives in Electrophotographic Image Receiving Sheet> In the electrophotographic image receiving sheet of the present invention, various additives are used for the purpose of improving the stability of the output image and the stability of the image receiving layer itself. be able to. As the additive,
Various known antioxidants, anti-aging agents, ultraviolet absorbers,
Examples thereof include light stabilizers, deterioration preventing agents, ozone deterioration preventing agents, preservatives and antifungal agents.

Examples of the antioxidant include chroman compounds, coumaran compounds, phenol compounds (eg, hindered phenols), hydroquinone derivatives, hindered amine derivatives, spiroindane compounds and the like. As the antioxidant, JP-A-61-15964 is used.
Those described in Japanese Patent No. 4 can also be mentioned.

As the antiaging agent, "Handbook Rubber.
Plastic compound chemicals, 2nd revised edition "(1993, Rubber Digest Co.), p76-121.

Examples of the ultraviolet absorber include benzotriazole compounds (described in US Pat. No. 3,533,794) and 4-thiazolidone compounds (US Pat. No. 335268).
1), a benzophenone compound (JP-A-46)
-2784), an ultraviolet absorbing polymer (described in JP-A-62-260152), and the like.
Examples of the metal complex include U.S. Pat. Nos. 4,241,155, 4,245,018 and 4,254,195, JP-A 61-88256, 62-174741, 63-199248, and JP-A-1-75568. Same 1
Those described in each publication of -74272 are mentioned. As the ultraviolet absorber and the light stabilizer, "Handbook Rubber / Plastic Compound Revision 2nd Edition" (1993,
Preferable examples are those described in Rubber Digest Co., Ltd.) p122-137.

The electrophotographic image-receiving sheet of the present invention may further contain known additives as photographic additives.
Examples of the photographic additives include, for example, Research Disclosure (hereinafter abbreviated as RD) No. 17643
(Dec. 1978), No. 18716 (1979)
November) and the same No. 307105 (1989 1
(January), and the relevant parts are summarized as follows.

[0077]     Types of additives RD17643 RD18716 RD307105 1. Brightener 24 pages 648 pages right column 868 pages 2. Stabilizer pages 24 to 25 pages 649 pages right column 868 to 870 pages 3. Light absorber page 25 to page 649 page right column page 873     UV absorber 4. Dye image stabilizer page 25 page 650 page right column page 872 5. Hardener 26 pages 651 pages left column 874-875 pages 6. Binder page 26 page 651 left column page 873-874 7. Plasticizer, lubricant 27 pages 650 pages right column 876 pages 8. Coating aid page 26-27 page 650 page right column 875-876 page     Surfactant 9. Antistatic agent page 27 page 650 page right column pages 876-877 pages Ten. Matting agent pp. 878-879

<Physical properties of electrophotographic image-receiving sheet> In the electrophotographic image-receiving sheet of the present invention, it is preferable that the toner image forming surface has a high whiteness. The whiteness is CI
In the E 1976 (L ^* a ^* b ^* ) color space, the L ^* value is preferably 80 or more, more preferably 85 or more, and particularly preferably 90 or more. In addition, the white tint is preferably as neutral as possible. The white tint is (a ^* ) ² + (b ^* ) in the L ^* a ^* b ^* space.
The value of ² is preferably 50 or less, more preferably 18 or less, and particularly preferably 5 or less.

The whiteness of the electrophotographic image-receiving sheet is preferably 85% or more as measured by the method specified in JIS P 8123, and has a spectral reflectance of 85% or more in the wavelength range of 440 nm to 640 nm and the same. The difference between the maximum spectral reflectance and the minimum spectral reflectance in the wavelength range is preferably within 5%, and the spectral reflectance is 85% or more in the wavelength range of 400 nm to 700 nm and the maximum spectral reflectance and the minimum in the same wavelength range. More preferably, the difference in spectral reflectance is within 5%.

The image receiving layer and the other layers are 1 × 1.
Range of 0 ⁶ to 1 × 10 ¹⁵ Ω / cm ² (25 ° C., 65%
It is preferable to have a surface electric resistance (under the condition of RH). When the surface electric resistance is less than 1 × 10 ⁶ Ω / cm ² , the toner amount when the toner is transferred to the image receiving layer is not sufficient, and the density of the obtained toner image becomes low,
On the other hand, if it exceeds 1 × 10 ¹⁵ Ω / cm ² , excessive charges are generated at the time of transfer, the toner is not sufficiently transferred, the image density becomes low, and static electricity is generated during handling of the electrophotographic image-receiving sheet. It is not preferable because dust easily adheres and misfeeds, double feeding, discharge marks, toner transfer gaps and the like are likely to occur during copying.

When the image receiving layer is transparent,
The optimum surface electric resistance is 10¹⁰-10^ThirteenΩ / cm^TwoDegree
5 × 10¹⁰~ 5 x 10¹²Ω / cm^TwoIs good
The amount of antistatic agent added should be decided accordingly.
It The surface of the support opposite to the image receiving layer.
The surface electric resistance is usually 5 × 10.⁸~ 3.2 × 10
¹⁰Ω / cm^TwoIt is about 1 × 10⁹~ 1 x 10 ¹⁰
Ω / cm^TwoIs preferred. The surface electric resistance is measured by J
In accordance with IS K 6911, the sample temperature 20 ℃,
Humidity control for more than 8 hours under the environment of 65% humidity and under the same environment
Then, using Advantest R8340 manufactured by
Under voltage of 100 V, measure after energizing for 1 minute.
It is obtained by setting.

The electrophotographic image-receiving sheet of the present invention comprises
It is preferable that the toner image forming surface has a high glossiness. The glossiness is preferably 45 degrees or more, more preferably 60 or more, even more preferably 75 or more, and particularly preferably 90 or more in the entire region from white without toner to black with maximum density. However, the upper limit of the glossiness is 1
A value of 10 or less is preferable, and a value of more than 110 gives a metallic luster, which is not preferable for image quality. The gloss is JIS
It can be measured based on Z 8741.

The electrophotographic image-receiving sheet of the present invention comprises
It is preferable that the toner image forming surface has high smoothness. As the smoothness, the arithmetic average roughness (Ra) is preferably 3 μm or less, more preferably 1 μm or less, and particularly preferably 0.5 μm or less in the entire region from white without toner to black with maximum density. The arithmetic mean roughness is JIS B
0601, B 0651, B 0652.

In the case of a transmission type electrophotographic image-receiving sheet in which the support is transparent and the image-receiving layer and the like are provided on the support, each layer on the support is also preferably transparent. Further, in the case of a reflection type electrophotographic image-receiving sheet in which the support is a reflective layer and the image-receiving layer or the like is provided on the support, each layer on the support does not need to be transparent,
Rather, it is preferably white.

The opacity of the electrophotographic image-receiving sheet is preferably 85% or more, more preferably 90% or more, as measured by the method defined in JIS P8138.

The electrophotographic image-receiving sheet of the present invention preferably does not adhere to the fixing heating member during fixing. Therefore, the 180-degree peel strength at the fixing temperature with the fixing member is preferably 0.1 N / 25 mm or less, and is 0.041 N.
/ 25 mm or less is more preferable. The 180-degree peel strength can be measured according to the method described in JIS K6887 using the surface material of the fixing member.

(Color toner for electrophotography) The color toner for electrophotography which is preferably used in the image-receiving sheet for electrophotography of the present invention is obtained by any of the pulverization method, the suspension granulation method and the like. May be. The electrophotographic color toner obtained by the pulverization method is manufactured by kneading, pulverizing and classifying. Examples of the binder resin used in the production of the color toner for electrophotography obtained by the pulverization method include acids such as acrylic acid, methacrylic acid and maleic acid and esters thereof; polyester; polysulfonate; polyether; A resin obtained by polymerizing the body or a resin obtained by copolymerizing two or more kinds of those monomers can be used. These binder resins, including a wax component, are sufficiently kneaded together with other toner constituent materials with a heat kneader such as a heat roll, a kneader or an extruder, and then mechanically pulverized and classified.

The electrophotographic color toner obtained by the pulverization method preferably contains a wax component in an amount of about 0.1 to 10% by mass, and 0.5 to 7% by mass, based on the mass of the toner.

The electrophotographic color toner obtained by the suspension granulation method comprises a binder resin, a colorant, and a release agent (a magnetic material, a charge control agent and other additives as required). , A hydrophilic inorganic dispersant and / or a viscosity adjusting agent having a BET specific surface area of 10 to 50 m ² / g, which is obtained by coating the obtained composition with a polymer having a carboxyl group by mixing in a solvent that is incompatible with water. By dispersing in an aqueous medium in the presence of, the resulting suspension is diluted with an aqueous medium, and then heating and / or depressurizing the obtained suspension to remove the solvent. Manufactured. In the present invention, the electrophotographic toner obtained by the suspension granulation method is more preferable than the electrophotographic toner obtained by the pulverization method.

As the binder resin in the electrophotographic toner obtained by the suspension granulation method, all known binder resins can be used. Specifically, styrenes such as styrene and chlorostyrene are used. , Ethylene, propylene, butylene, isoprene and other monoolefins, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate and other vinyl esters, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, acrylic Octyl acid, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, α-methylene aliphatic monocarboxylic acid esters such as dodecyl methacrylate, vinyl methyl ether, vinyl ethyl ether, vinyl ethers such as vinyl butyl ether, Vinyl methyl ketone, vinyl Shiruketon, homopolymers and copolymers such as vinyl ketones such as vinyl isopropenyl ketone. Typical examples of the binder resin include polystyrene resin, polyester resin, styrene-
Alkyl acrylate copolymers, styrene-alkyl methacrylate copolymers, styrene-acrylonitrile copolymers, styrene-butadiene copolymers, styrene-maleic anhydride copolymers, polyethylene resins, polypropylene resins and the like. , Polyurethane resin, epoxy resin, silicone resin, polyamide resin, modified rosin, paraffins, waxes, and the like. Among these, styrene-acrylic resin is particularly preferable.

Any known coloring agent may be used as the coloring agent contained in the binder resin. Examples thereof include carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue and DuPont. Oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Yellow 97, C.I.
I. Pigment Yellow 12, C.I. I. Pigment
Yellow 17, C.I. I. Pigment Blue 15: 1,
C. I. Pigment Blue 15: 3 and the like. The content of the colorant is preferably 2% by mass to 8% by mass. When the content of the colorant is less than 2% by mass, the coloring power becomes weak, and when it exceeds 8% by mass, the transparency of the electrophotographic color toner is deteriorated.

It is preferable that the color toner for electrophotography contains a releasing agent. Wax is preferably used as the release agent, but specifically, low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene; silicone resin softened by heating, oleic acid amide, erucic acid amide, ricinoleic acid amide, Fatty acid amides of stearic acid amide; plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; montan wax, ozokerite, ceresin, paraffin wax, micro Mineral / petroleum waxes such as crystallin wax and Fischer-Tropsch wax, and modified products thereof can be used. When a wax containing a wax ester having a large polarity, such as carnauba wax or candelilla wax, is used as these release agents, the amount of the wax exposed on the surface of the toner particles is large. Waxes having a small polarity such as paraffin wax tend to reduce the amount of exposure to the surface. The melting point of the wax is preferably 30 to 150 ° C, and more preferably 40 to 140 ° C regardless of the tendency of exposure to the surface.

The color toner for electrophotography is mainly formed of the colorant and the binder resin, and the average particle size thereof is about 3 to 15 μm, and 4 to 8 μm is particularly preferably used. To be done. Further, the storage elastic modulus G '(angular frequency of 10 ra at 150 ° C. of the electrophotographic color toner itself is
10 to 200 Pa is preferable as the measurement (d / sec).

Further, the electrophotographic color toner includes
External additives may be added. As the external additive, inorganic compound fine powder and organic compound fine particles are used. Examples of the inorganic compound fine particles include SiO ₂ and Ti.
O ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , Fe ₂
O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, Z
rO ₂ , CaO · SiO ₂ , K ₂ O · (TiO ₂ ) n,
Al ₂ O ₃ .2SiO ₂ , CaCO ₃ , MgCO ₃ , B
Examples include aSO ₄ , MgSO _{4, and the} like. Examples of the organic compound fine particles include fine powders of fatty acids or their derivatives, metal powders of these, and resin fine powders of fluororesins, polyethylene resins, acrylic resins, and the like.

(Image Forming Method) The image forming on the electrophotographic image-receiving sheet of the present invention is not particularly limited and can be carried out by a usual electrophotographic method. The electrophotographic method can be performed using a known electrophotographic image forming apparatus. The image forming apparatus includes a conveyance unit for an electrophotographic image receiving sheet, an electrostatic latent image forming unit, a developing unit arranged in proximity to the electrostatic latent image forming unit, and a fixing unit. Depending on the model, an intermediate transfer unit may be provided in the center of the apparatus main body in proximity to the electrostatic latent image forming unit and the transport unit of the electrophotographic image receiving sheet.

Unlike the method of directly transferring the toner image formed on the developing roller to the electrophotographic image-receiving sheet, the intermediate transfer section uses an intermediate belt, and after the toner image is primarily transferred to the intermediate transfer belt. And an intermediate belt transfer type image forming apparatus that secondarily transfers the toner image onto an electrophotographic image receiving sheet. The intermediate transfer belt transfer method is more preferable for high image quality.

Regarding the above-mentioned transfer, from the viewpoint of improving the image quality, an adhesive transfer or heat-assisted transfer system is known in place of, or in combination with, electrostatic transfer or bias roller transfer. For example, JP-A-63-113
576 and JP-A-5-341666 describe the specific structure thereof. In particular, the method using a heat-assisted transfer type intermediate transfer belt is preferable when a color toner for electrophotography having a small particle diameter (7 μm or less) is used. As the intermediate transfer belt, for example, an endless belt formed of electroformed nickel, which has a silicon or fluorine-based thin film on the surface and is provided with a peeling property is used.
A cooling device is preferably provided on the intermediate transfer belt after the toner transfer onto the image receiving sheet or in the latter half of the transfer.
By the cooling device, the electrophotographic toner is cooled to the softening temperature or the glass transition temperature of the binder used for the electrophotographic toner, efficiently transferred to the electrophotographic image-receiving sheet, and peelable from the intermediate transfer belt.

The fixing is an important step that affects the gloss and smoothness of the final image. As the fixing method, a fixing method using a heating and pressure roller, a belt fixing method using a belt, and the like are known, but the belt fixing method is more preferable in terms of image quality such as gloss and smoothness. preferable. Regarding the belt fixing method, for example, Japanese Patent Laid-Open No. 11-3
An oilless belt fixing method described in JP-A-52819, JP-A-11-231671, and JP-A-5-3416.
No. 66, a method for simultaneously achieving secondary transfer and fixing,
Etc. are known. The surface of the fixing belt used in the belt fixing method is preferably surface-treated with a silicone-based, fluorine-based, or a covalent-based surface-treating agent in order to prevent toner peeling or offset of toner components. . Further, it is preferable to provide a cooling device for the fixing belt in the latter half of the fixing so that the electrophotographic image-receiving sheet can be peeled off well. The cooling temperature in the cooling device is preferably not higher than the softening point or glass transition point of the binder resin in the electrophotographic color toner, the thermoplastic resin used in the image receiving layer of the electrophotographic image receiving sheet. On the other hand, in the initial stage of fixing, it is necessary to raise the temperature to a temperature at which the image receiving layer in the electrophotographic image receiving sheet or the electrophotographic color toner is sufficiently softened. Specifically, the cooling temperature is practically preferably 70 ° C. or lower and 30 ° C. or higher, and 180 ° C. or lower and 100 ° C. or higher in the initial fixing stage.

[0099]

EXAMPLES Examples of the present invention will be described below.
The invention is in no way limited to these examples. In the following examples and comparative examples, “%” and “part” represent “mass%”, respectively. Further, the "compressive elastic modulus" is a value measured according to ASTM D 695, and the "thermal conductivity" is the transfer paper whose humidity is adjusted according to JIS P 8111, which is described in JP-A-53-66279. It is the value measured by the described method.

Example 1 <Preparation of Support> As a support, polyethylene having a basis weight of 160 g was laminated with 13 μm of polyethylene on the surface on the image receiving layer side and 15 μm on the surface of the backcoat layer side. After applying a corona discharge treatment to the polyethylene layer, a wire coater is used to apply an undercoat layer composition having the following composition on both surfaces so that the coating weight after drying is about 0.1 g / m ^2. And dried.

-Composition of composition for undercoat layer- ・ Gelatin: 5g ・ Water: 1000g

<Preparation of Intermediate Layer> An intermediate layer composition having the following composition was applied by a wire coater so that the film thickness after drying was 5 μm, and dried to obtain an intermediate layer (content ratio (mass ratio)).
(Low elastic modulus binder / low thermal conductivity organic particles) = 1.
5) was produced.

[0103] - Composition of the intermediate layer composition - Polypropylene particles (low thermal conductivity organic particles; volume average particle diameter _(D 50) = _3μm, thermal conductivity = 2.8 × 10
^-4 (cal / sec · ° C · cm), melting point = 164
C.): 25 g-Polyurethane aqueous dispersion (solid content = 30% by mass) (low elastic modulus binder; compression elastic modulus = 0.14 × 10 ⁴ (k)
g / cm ² ): 125 g

<Evaluation of Surface Smoothness in Intermediate Layer> The maximum surface roughness of the obtained intermediate layer was measured according to JIS B 06.
The surface smoothness was evaluated by measuring the surface roughness (Max (μm)) according to No. 01. The results are shown in Table 1.

<Evaluation of Solvent Barrier Property in Intermediate Layer>
The intermediate layer was wetted with a 1/1 (mass ratio) mixed solution of toluene and methyl ethyl ketone, and whether or not there was strike-through of the solvent was visually observed and evaluated. The results are shown in Table 1.

<Preparation of Image Receiving Layer> An image receiving layer composition having the following composition was dried with a wire coater to give a coating film thickness of 10 μm.
It was applied so as to have a thickness of m and dried to form a toner image-receiving layer.

-Composition of the composition for the image receiving layer-Aqueous acrylic varnish (Hiros XF-3171L (solid content 28.8% by mass) manufactured by Hoshiko Kagaku Kogyo Co., Ltd.)-1
00 parts water-dispersed wax (Chukyo Yushi Co., Ltd., Cerosol-5)
24, solid content 30 mass%) 8.7 parts / ion-exchanged water 50 parts

<Preparation of Backcoat Layer> Further, a backcoat layer composition having the following composition was applied to the surface opposite to the image receiving layer with a bar coater to give a dry film weight of 4.5 g / m ² . As described above, a back coat layer was prepared to prepare an electrophotographic image-receiving sheet, and the sheet was cut into A4.

-Composition of Backcoat Layer Composition-Polyester resin (Vylonal MD-1200 Toyobo Co., Ltd.): 90 g Matting agent (Eposter L15 Nippon Shokubai Co., Ltd.): 50
g ・ Water: 10000g

<Evaluation of Adhesion Resistance> The obtained electrophotographic image-receiving sheet was stored at 40 ° C. and 80% RH for 24 hours, and then the image-receiving layers of the electrophotographic image-receiving sheets were superposed with the image-receiving layers facing each other. A load of 3.5 cm square and 500 g was applied, the sample was placed in the same environment for 7 days, and the state when the sample was separated was evaluated according to the following evaluation criteria. The results are shown in Table 1. In the present invention, “◯ or higher” is a practically acceptable level.

-Evaluation criteria- ・ ◎: No peeling noise or adhesion mark ・ ○: Minor peeling noise or adhesion mark remains *: Adhesion trace is less than 1/4 ・ ×: 1/4 to less than 1/2 is bonded ・ XX: 1/2 or more is adhesive

<Evaluation of Cracks> A color laser printer C-220 was applied to the obtained electrophotographic image-receiving sheet.
0 (manufactured by Fuji Xerox Co., Ltd.) was used to draw a uniform image of 10 cm with a maximum density of black, and the image was taken in a predetermined environment (10 ° C,
15% RH) for 1 day. After that, 1, 2, 3,
Round rods of 4 and 5 cmφ were prepared, respectively, and wound from a large-diameter rod to a small-diameter rod in order so that the image surface was on the outside, and the minimum diameter at which cracking did not occur was recorded. The results are shown in Table 1. In the present invention, 2 cmφ or less is a practically preferable level.

<Evaluation of image quality> Using the color laser printer described above, B was applied to the obtained electrophotographic image-receiving sheet.
/ W condition, 6 cm (0, 20, 40, 60, 80, and 100%) density of 10 cm □ is drawn out, and this 6-step part is JIS Z 8741, digital variable angle gloss meter (Suga tester Manufactured by UGV-5D), and the minimum value was recorded by measuring at 45 degrees. The results are shown in Table 1.
In the present invention, 70% or more is a practically preferable level.

<Evaluation of Anti-Offset Property> The obtained electrophotographic image-receiving sheet was passed through the fixing section normally in an environment of 30 ° C. and 80% RH by using the color laser printer in an oilless fixing system, and It was confirmed that there was no shell-like unevenness on the image surface. The results are shown in Table 1. In the present invention, “◯” is a practically preferable level.

In each of the above evaluations, the self-made fixing belt machine shown in FIG. 1 was further installed in the image receiving sheet discharging section of the printer so that the timings of discharging and feeding were interlocked.

(Example 2) "Preparation of intermediate layer" of Example 1
In the composition of the intermediate layer composition, polypropylene (low thermal conductivity organic particles; volume average particle diameter (D ₅₀ ) =
3 μm, thermal conductivity = 2.8 × 10 ⁻⁴ (cal / sec)
(° C · cm), melting point = 164 ° C.), 25 g of polystyrene (low thermal conductivity organic particles; volume average particle diameter (D ₅₀ ) =
1.5 μm, thermal conductivity = 2.77 × 10 ⁻⁴ (cal /
sec · ° C. · cm), melting point = 239 ° C.), except that the intermediate layer (content ratio (mass ratio) (low elastic modulus binder / low thermal conductivity organic particles)) was changed to 25 g in the same manner as in Example 1.
1.5) was prepared, an image receiving layer was prepared, a back coat layer was prepared, an image receiving sheet for electrophotography was prepared, and each evaluation was performed. The results are shown in Table 1.

(Example 3) "Preparation of intermediate layer" of Example 1
In the composition of the intermediate layer, polyurethane (low elastic modulus binder; compression elastic modulus = 0.14 × 10)
125 g of ⁴ (kg / cm ² ) was added to styrene-butadiene rubber (low elastic modulus binder; compression elastic modulus = 0.21 ×).
Except that 125 g of 10 ⁴ (kg / cm ² )) was used,
An intermediate layer (content ratio (mass ratio) (low elastic modulus binder / low thermal conductivity organic particles) = 1.5) was prepared in the same manner as in Example 1, an image receiving layer was prepared, and a back coat layer was prepared. An image receiving sheet for electrophotography was prepared and each evaluation was performed. The results are shown in Table 1.

(Example 4) "Preparation of intermediate layer" of Example 1
In the composition for the intermediate layer, in the composition of the intermediate layer, the compounding amount of polypropylene (low thermal conductivity organic particles) was changed to 4 g, and the compounding amount of polyurethane (low elastic modulus binder) was 153 g.
In the same manner as in Example 1, except that the intermediate layer (content ratio (mass ratio) (low elastic modulus binder / low thermal conductivity organic particles) = 11.5) was prepared and an image receiving layer was prepared. A coat layer was prepared to prepare an electrophotographic image-receiving sheet, and each evaluation was performed. The results are shown in Table 1.

(Example 5) "Preparation of intermediate layer" of Example 1
In the composition of the intermediate layer composition, 125 g of polyurethane (low elastic modulus binder) was added to styrene-methyl methacrylate copolymer (low elastic modulus binder; compression elastic modulus = 2.8 × 10 ⁴ (kg / cm 2 ² )) 125g
In the same manner as in Example 1, except that the intermediate layer (content ratio (mass ratio) (low elastic modulus binder / low thermal conductivity organic particles) = 1.5) was prepared and an image receiving layer was prepared. A coat layer was prepared to prepare an electrophotographic image-receiving sheet, and an electrophotographic image-receiving sheet was prepared, and each evaluation was performed. The results are shown in Table 1.

(Example 6) "Preparation of intermediate layer" in Example 1
In the composition of the intermediate layer composition, polypropylene (low thermal conductivity organic particles; volume average particle diameter (D ₅₀ ) =
3 μm, thermal conductivity = 2.8 × 10 ⁻⁴ (cal / sec)
· ℃ · cm), the 25g of melting point = 164 ° C.), polycarbonate (low thermal conductivity organic particles; volume average particle diameter _(D 50) = _3μm, thermal conductivity = 4.6 × ¹⁰ -4 (c
al / sec · ° C · cm), melting point = 260 ° C) 25 g
In the same manner as in Example 1, except that the intermediate layer (content ratio (mass ratio) (low elastic modulus binder / low thermal conductivity organic particles) = 1.5) was prepared and an image receiving layer was prepared. A coat layer was prepared to prepare an electrophotographic image-receiving sheet, and each evaluation was performed. The results are shown in Table 1.

(Example 7) "Preparation of intermediate layer" of Example 1
In the composition of the intermediate layer composition, polyurethane (low elastic modulus binder; compression elastic modulus = 0.10 × 10
⁴ (kg / cm ² ) 125 g was changed to 66.7 g, except that the intermediate layer (content ratio (mass ratio) (low elastic modulus binder / low thermal conductivity organic particles) =
0.2) was prepared, an image receiving layer was prepared, a back coat layer was prepared, an electrophotographic image receiving sheet was prepared, and each evaluation was performed. The results are shown in Table 1.

(Comparative Example 1) "Preparation of intermediate layer" in Example 1
In the composition of the intermediate layer composition, polypropylene (low thermal conductivity organic particles; volume average particle diameter (D ₅₀ ) =
3 μm, thermal conductivity = 2.8 × 10 ⁻⁴ (cal / sec)
・ ° C · cm), melting point = 164 ° C.) 25 g of low density polyethylene (high thermal conductivity organic particles; volume average particle diameter (D
₅₀ ) = 3 μm, thermal conductivity = 8 × 10 ⁻⁴ (cal / s)
ec.degree. C..cm), melting point = 101.degree. C.), and the intermediate layer (content ratio (mass ratio) (low elastic modulus binder / low thermal conductivity organic particles)) in the same manner as in Example 1
1.5) was prepared, an image receiving layer was prepared, a back coat layer was prepared, an image receiving layer was prepared, a back coat layer was prepared, an image receiving sheet for electrophotography was prepared, and each evaluation was performed. The results are shown in Table 1.

(Comparative Example 2) "Preparation of intermediate layer" in Example 1
In the composition of the intermediate layer composition, polypropylene (low thermal conductivity organic particles; volume average particle diameter (D ₅₀ ) =
3 μm, thermal conductivity = 2.8 × 10 ⁻⁴ (cal / sec)
.Degree. C..cm) and melting point = 164.degree. C.) were used, and an electrophotographic image-receiving sheet was prepared in the same manner as in Example 1, and each evaluation was performed. The results are shown in Table 1.

[0124]

[Table 1]

[0125]

According to the present invention, high gloss, high image quality,
It is possible to provide an electrophotographic image-receiving sheet capable of forming an image excellent in anti-offset property without generation of cracks.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a fixing belt machine.

[Explanation of symbols]

1 Self-made belt fixing machine 2 fixing belt 3 heating roller 4 pressure roller 5 Tension roller 6 cleaning roller

Claims (9)

[Claims] 1. An image receiving sheet for electrophotography, comprising a support, an image receiving layer, and an intermediate layer containing a low elastic modulus binder and low thermal conductivity organic particles. 2. The content ratio (mass ratio) of the low elastic modulus binder and the low thermal conductivity organic particles (low elastic modulus binder / low thermal conductivity organic particles) in the intermediate layer is 0.25 to 9. The image-receiving sheet for electrophotography according to 1. 3. The low elastic modulus binder has a compressive elastic modulus of 1.
The image-receiving sheet for electrophotography according to claim 1, which has a density of × 10 ⁴ (kg / cm ² ) or less. 4. The low elastic modulus binder is polyethylene,
Polyurethane, polybutadiene, styrene-butadiene rubber, polyacrylic acid ester, epoxy resin, and
The electrophotographic image-receiving sheet according to any one of claims 1 to 3, which is at least one of a vinyl acetate-ethylene copolymer. 5. The thermal conductivity of the low thermal conductivity organic particles is 3 ×.
The electrophotographic image-receiving sheet according to any one of claims 1 to 4, which has a temperature of 10 ^-4 (cal / sec. ° C · cm) or less. 6. The melting point of the low thermal conductivity organic particles is 130 ° C.
The electrophotographic image-receiving sheet according to claim 1, which is as described above. 7. The particle size (volume average particle size (D ₅₀ )) of the low thermal conductivity organic particles is not more than the thickness of the intermediate layer.
7. The electrophotographic image-receiving sheet according to any one of 1 to 6. 8. The image receiving sheet for electrophotography according to claim 1, wherein the low thermal conductivity organic particles are at least one of polypropylene, polystyrene, and a styrene-acrylonitrile copolymer. 9. The image receiving sheet for electrophotography according to claim 1, wherein the maximum surface roughness of the intermediate layer is 7 μm or less.