JP2006106718A - Electrophotographic image-receiving sheet and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic image-receiving sheet having both of excellent fixing property and cracking resistance, and to provide an image forming method using the electrophotographic image-receiving sheet. <P>SOLUTION: The electrophotographic image-receiving sheet contains a support and at least two polymer layers on the support, wherein at least one layer of the polymer layers has voids. In a preferable embodiment, a polymer layer in the polymer layers except for the outermost surface polymer layer has voids. The method for forming an image is carried out by using the electrophotographic image receiving sheet. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrophotographic image-receiving sheet having excellent fixing properties and crack resistance, and an image forming method using the electrophotographic image-receiving sheet.

Conventionally, in electrophotographic image-receiving sheets, it has been proposed to add void particles to the toner image-receiving layer for the purpose of improving heat storage (see Patent Document 1). According to this proposal, fixability can be improved by adding void particles to the toner image-receiving layer.
However, when the amount of void particles added is increased, there is a problem that the surface of the toner image is cracked when the electrophotographic image receiving sheet is lifted or placed in an album, resulting in poor handling.
Therefore, a high-quality electrophotographic image-receiving sheet having both excellent fixing properties and cracking resistance that can be satisfactorily satisfied has not yet been obtained, and its prompt provision is desired.

JP 2003-322993 A

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, an object of the present invention is to provide a high-quality electrophotographic image-receiving sheet having both excellent fixing properties and crack resistance, and an image forming method using the electrophotographic image-receiving sheet.

Means for solving the problems are as follows. That is,
<1> An electrophotographic image-receiving sheet comprising a support and at least two polymer layers on the support, wherein at least one of the polymer layers has voids.
<2> The electrophotographic image-receiving sheet according to <1>, wherein the polymer layer other than the outermost polymer layer has voids.
<3> The electrophotographic image-receiving sheet according to any one of <1> to <2>, wherein the support has a base paper and a polyolefin resin layer on both sides of the base paper.
<4> The electrophotographic image-receiving sheet according to any one of <1> to <3>, wherein the polymer layer includes at least an undercoat layer and a toner image-receiving layer, and the toner image-receiving layer is provided on the undercoat layer. is there.
<5> The electrophotographic image-receiving sheet according to any one of <1> to <4>, wherein the void is formed by hollow particles contained in the polymer layer.
<6> The electrophotographic image-receiving sheet according to any one of <1> to <4>, wherein the void is formed by fine particles contained in the polymer layer.
<7> The electrophotographic image-receiving sheet according to any one of <2> to <6>, wherein the porosity of the polymer layer having voids other than the outermost polymer layer is 30% by volume or more.
<8> The electrophotographic image-receiving sheet according to any one of <2> to <7>, wherein the outermost surface polymer layer contains an aqueous polymer.
<9> The electrophotographic image-receiving sheet according to <8>, wherein the aqueous polymer contains a water-dispersible polyester emulsion.
<10> The electrophotographic image-receiving sheet according to <9>, wherein the water-dispersible polyester emulsion is a self-dispersing water-dispersible polyester emulsion.
<11> The electrophotographic image-receiving sheet according to <10>, wherein the self-dispersing water-dispersible polyester emulsion satisfies the following characteristics (1) to (4).
(1) Number average molecular weight (Mn) = 5000 to 10,000
(2) Molecular weight distribution (weight average molecular weight / number average molecular weight) ≦ 4
(3) Glass transition temperature (Tg) = 40-100 ° C.
(4) Volume average particle diameter = 20 to 200 nm
<12> Toner image formation comprising a support and at least two polymer layers on the support, and at least one of the polymer layers having a void forms a toner image on an electrophotographic image-receiving sheet Process,
And an image surface smoothing and fixing step of smoothing the surface of the toner image formed by the toner image forming step.
<13> The image forming method according to <12>, wherein the polymer layers other than the outermost polymer layer have voids.
<14> 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. The image forming method according to any one of 12> to <13>.

  The electrophotographic image-receiving sheet of the present invention comprises a support and at least two polymer layers on the support, and at least one of the polymer layers has voids. In the electrophotographic image-receiving sheet of the present invention, since at least one of the polymer layers has voids, a high-performance electrophotographic image-receiving sheet having both excellent fixability and crack resistance can be obtained.

  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 for smoothing the surface of the toner image formed by the toner image forming step. Fixing process. According to the image forming method of the present invention, since the electrophotographic image receiving sheet of the present invention is used, a high-quality image close to a silver salt photographic print can be efficiently obtained by simple processing.

  According to the present invention, there are provided a high-quality electrophotographic image-receiving sheet that can solve conventional problems and has both excellent fixability and crack resistance, and an image forming method using the electrophotographic image-receiving sheet. be able to.

(Electrophotographic image-receiving sheet)
The electrophotographic image-receiving sheet of the present invention comprises a support and at least two polymer layers on the support, and further comprises other layers as necessary.

<Polymer layer>
The polymer layer has at least two layers, and at least one of the polymer layers has voids, and contains a polymer and, if necessary, other components.

-Gap-
Here, it is preferable to have the said space | gap in polymer layers other than an outermost surface polymer layer. Specifically, (1) when the electrophotographic image-receiving sheet has the first polymer layer and the second polymer layer in this order on the support, it is preferable that the first polymer layer has voids. The second polymer layer may or may not have voids, and when the second polymer layer has voids, it is preferably less than the amount of voids in the first polymer layer.
(2) When the electrophotographic image-receiving sheet has the first polymer layer, the second polymer layer, and the third polymer layer in this order on the support, voids are formed in the first polymer layer and the second polymer layer. It is preferable to have. Note that the third polymer layer may or may not have voids, and when the third polymer layer has voids, the amount of voids in the first polymer layer and the second polymer layer is more than that. Less is preferred.

There is no restriction | limiting in particular as a method for forming a space | gap in the said polymer layer, Although it can select suitably according to the objective, The following methods are mentioned suitably.
(1) Add void particles to the polymer layer.
(2) Add fine particles to the polymer layer.
(3) Foam is mixed in the coating process, or a foaming agent is added to form a polymer layer having a porous structure.
Among these, the method (1) is preferable from the viewpoint of the ease of forming the coating film, and the method (2) is preferable from the viewpoint of the void volume.

  The void particles in the method (1) are not particularly limited as long as they have voids, and can be appropriately selected according to the purpose. For example, a single hollow portion exists in the particle. Examples include hollow particles, multi-hollow particles having many hollow portions in the particles, and porous particles. These may be used individually by 1 type and may use 2 or more types together. Among these, hollow particles are particularly preferable from the viewpoint of the size of the porosity.

  There is no restriction | limiting in particular as a material of the said void particle, Although it can select suitably according to the objective, For example, a thermoplastic resin etc. are mentioned suitably. The void particles may be appropriately manufactured or may be commercially available products. Examples of the commercially available products include Ropaque HP1055, Ropaque HP433J (all manufactured by Nippon Zeon Co., Ltd.), SX866 (manufactured by JSR Corporation), and the like.

  The content of the polymer layer containing the voids, particularly the polymer layer other than the outermost polymer layer, is preferably 30% by volume or more, and more preferably 40% by volume or more. If the void content is less than 30% by volume, the fixability may not be improved. The content (volume%) of the void in the polymer layer containing the void is, for example, (1) a method by observing a cross section of the polymer layer containing the void under a microscope, and (2) a polymer containing the void. It can be calculated by measuring by the method of calculating from the specific gravity of the layer, or (3) mercury intrusion method if it is a porous structure.

  The void ratio of the void particles is preferably 30% by volume or more, and more preferably 40 to 90% by volume. When the porosity of the void particles is less than 30% by volume, the voids of the entire polymer layer may not be increased. The porosity (volume%) of the void particles can be calculated based on the volume ratio by observing the void particles with an electron microscope, measuring the average outer diameter and the average inner diameter, for example.

  There is no restriction | limiting in particular in the volume average particle diameter of the said void particle | grains, According to the objective, it can select suitably, For example, 2 micrometers or less are preferable and 0.1-1.5 micrometers is more preferable. When the volume average particle diameter of the void particles exceeds 2 μm, the stability of the coating liquid may be impaired. The volume average particle diameter of the void particles can be measured by observing with an electron microscope, for example.

  Regarding the method of adding the fine particles (2) to the polymer layer, either inorganic fine particles or organic fine particles can be used as the fine particles. It is preferable to form a polymer layer having a porous structure in the coating process using a coating solution containing the fine particles.

Examples of the inorganic fine particles include silica, colloidal silica, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, magnesium carbonate, calcium sulfate, pseudoboehmite, zinc oxide, and hydroxide. Fine particles composed of zinc, alumina, alumina silicate, calcium silicate, magnesium silicate, zirconium oxide, zirconium hydroxide, cerium oxide, lanthanum oxide, yttrium oxide, etc., among these, from the viewpoint of forming a good porous structure Silica fine particles, colloidal silica fine particles, pseudo boehmite fine particles, and alumina fine particles are preferable.
The inorganic fine particles may be used as primary particles or in a state where secondary particles are formed. The average primary particle size of these inorganic fine particles is preferably 2 μm or less, and more preferably 200 nm or less. Among these, silica fine particles having an average primary particle size of 20 nm or less, alumina fine particles having an average primary particle size of 20 nm or less, and pseudoboehmite having an average primary particle size of 2 to 15 nm are preferable.
The silica fine particles are generally roughly classified into wet method particles and dry method (gas phase method) particles according to the production method. In the above-mentioned wet method, the mainstream is a method in which activated silica is produced by acid decomposition of silicate, and this is appropriately polymerized and agglomerated and precipitated to obtain hydrous silica. On the other hand, the vapor phase method is a method by high-temperature vapor phase hydrolysis of silicon halide (flame hydrolysis method), a method in which silica sand and coke are heated and reduced by an arc in an electric furnace and oxidized with air. The method of obtaining anhydrous silica by the (arc method) is the mainstream. “Gas phase method silica” means anhydrous silica fine particles obtained by the gas phase method. Therefore, as the silica fine particles, gas phase method silica fine particles are particularly preferable.

  The organic fine particles (polymer fine particles) can be used in the form of a hydrophilic solvent dispersion of various polymers. Specifically, (co) polymers of vinyl monomers, ester polymers, urethane polymers, amide polymers, epoxy polymers, or aqueous dispersions such as modified products and copolymers thereof can be used. Among these, it is preferable to use a vinyl monomer (co) polymer and a urethane polymer, and from the viewpoint of coating strength, a vinyl monomer (co) polymer is particularly preferable.

  Examples of the vinyl monomer include aromatic vinyl compounds (for example, styrene, α-methylstyrene, p-hydroxystyrene, chloromethylstyrene and vinyltoluene), vinyl cyanide (for example, (meth) acrylonitrile and α-chloroacrylonitrile). Carboxylic acid vinyl esters (eg, vinyl acetate, vinyl benzoate, vinyl formate) aliphatic conjugated dienes (eg, 1,3-butadiene and isoprene), (meth) acrylic acid alkyl esters (eg, methyl (meth) acrylate, Ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate), (meth) acrylic acid alkylaryl ester (for example, benzyl (meth) acrylate), ( Meta) Acrylic acid-substituted alkyl esters (for example, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate)), alkyl (meth) acrylamide (for example, (meta ) Acrylamide, dimethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, n-butyl (meth) acrylamide, tert-butyl (meth) acrylamide, tert-octyl (meth) acrylamide), substituted alkyl (meth) acrylamide (e.g. , Dimethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide), polymerizable oligomer (for example, one-end methacryloylated polymethyl methacrylate) Goma, a methacryloyl group at one end a polystyrene oligomer, a methacryloyl group at one end of polyethylene glycol) is preferably used, such as.

The polymer fine particles are desirably crosslinked with a polyfunctional monomer. Examples of the polyfunctional monomer include aromatic divinyl compounds (for example, divinylbenzene, divinylnaphthalene or derivatives thereof), esters and amides of diethylenecarboxylic acid (for example, ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth)). Acrylate, dipentaerystol hexa (meth) acrylate), and other divinyl compounds (for example, divinyl sulfide compounds or divinyl sulfone compounds).
The introduction ratio of the polyfunctional monomer in the polymer fine particles is preferably 2 mol% or more, and more preferably 5 mol% or more. Thereby, the deformation | transformation of the particle | grains at the time of application | coating and drying can be prevented, and the space | gap of a polymer layer can be enlarged.

  These polymer fine particles are usually obtained by an emulsion polymerization method. The surfactants, polymerization initiators, etc. used there may be those used in conventional methods. Regarding the method for synthesizing the polymer fine particles, U.S. Pat. Nos. 2,852,368, 2,853,457, 3,411,911, 3,411,912, No. 4,197,127, Belgian Patent No. 688,882, No. 691,360, No. 712,823, JP-B No. 45-5331, JP-A No. 60-18540 No. 5, No. 51-130217, No. 58-137831, No. 55-50240, and the like.

10-100 nm is preferable and, as for the average particle diameter of the said polymer fine particle, 15-80 nm is more preferable. Further, the glass transition temperature (Tg) of the polymer fine particles is not particularly limited and can be appropriately selected according to the purpose. From the viewpoint of preventing deformation of the particles during coating and drying, the glass transition temperature is high and hard. Is preferable, and can be appropriately selected in consideration of the type of binder to be used and the amount ratio with the binder.
The polymer fine particles preferably form secondary particles, whereby the porosity of the polymer layer can be increased.

  The organic fine particle (polymer fine particle) is a coating layer formed by crosslinking and curing a coating layer (polymer layer) coated with a coating solution (coating solution A) further containing a water-soluble resin, and coating the coating solution. A polymer layer having a porous structure by applying a basic solution (coating solution B) having a pH of 8 or higher to the coating layer at any time during dry coating and before the coating layer exhibits reduced-rate drying Can be formed.

Examples of the water-soluble resin include a polyvinyl alcohol-based resin (polyvinyl alcohol (PVA), acetoacetyl-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified resin that has a hydroxyl group as a hydrophilic structural unit). Polyvinyl alcohol, polyvinyl acetal, etc.], cellulose resins [methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, etc.] , Chitins, chitosans, starch, resins with ether linkages [polyethylene oxide (PEO), Propylene oxide (PPO), polyethylene glycol (PEG), poly ether (PVE)], and resins having carbamoyl groups [polyacrylamide (PAAM), polyvinyl pyrrolidone (PVP), polyacrylic acid hydrazide, etc.] and the like.
Moreover, the polyacrylic acid salt which has a carboxyl group as a dissociable group, maleic acid resin, alginate, gelatins, etc. can be mentioned.

Among these, polyvinyl alcohol resin is particularly preferable. Examples of the polyvinyl alcohol include Japanese Patent Publication No. 4-52786, Japanese Patent Publication No. 5-67432, Japanese Patent Publication No. 7-29479, Japanese Patent No. 2537827, Japanese Patent Publication No. 7-57553, Japanese Patent No. 2502998, and Japanese Patent No. 3053231. JP-A-63-176173, JP-A-2604367, JP-A-7-276787, JP-A-9-207425, JP-A-11-58941, JP-A-2000-135858, JP-A-2001-205924, JP 2001-287444, JP 62-278080, JP 9-39373, JP 2750433, JP 2000-158801, JP 2001-213045, JP 2001-328345, JP 8 -324105, JP-A-11-348417, etc. Etc., and the like.
Examples of water-soluble resins other than polyvinyl alcohol resins include the compounds described in [0011] to [0014] of JP-A No. 11-165461.
These water-soluble resins may be used alone or in combination of two or more.

  As content of the said water-soluble resin, 4-25 mass% is preferable with respect to the total solid content mass of a polymer layer, and 5-16 mass% is more preferable.

Boron compounds are preferred for crosslinking the water-soluble resin, particularly polyvinyl alcohol. Examples of the boron compound include borax, boric acid, borates (for example, orthoborate, InBO ₃ , ScBO ₃ , YBO ₃ , LaBO ₃ , Mg ₃ (BO ₃ ) ₂ , Co ₃ (BO ₃ ) ₂ , diborate. (For example, Mg ₂ B ₂ O ₅ , Co ₂ B ₂ O ₅ ), metaborate (for example, LiBO ₂ , Ca (BO ₂ ) ₂ , NaBO ₂ , KBO ₂ ), tetraborate (for example, Na ₂ B _{4 O 7 · 10H 2 O)} , can be mentioned five borate _{(e.g., KB 5 O 8 · 4H 2} O, Ca 2 B 6 O 11 · 7H 2 O, CsB 5 O 5) or the like. Among them, promptly Of these, borax, boric acid, and borate are preferable, and boric acid is particularly preferable.

As the water-soluble resin crosslinking agent, compounds other than boron compounds include, for example, aldehyde compounds such as formaldehyde, glyoxal, and glutaraldehyde; ketone compounds such as diacetyl and cyclopentanedione; bis (2-chloroethylurea) Active halogen compounds such as 2-hydroxy-4,6-dichloro-1,3,5-triazine, 2,4-dichloro-6-S-triazine sodium salt; divinylsulfonic acid, 1,3-vinylsulfonyl- Active vinyl compounds such as 2-propanol, N, N′-ethylenebis (vinylsulfonylacetamide), 1,3,5-triacryloyl-hexahydro-S-triazine; N such as dimethylolurea and methyloldimethylhydantoin -Methylol compounds; melamine resins (eg methylol Epoxy resins; isocyanate compounds such as 1,6-hexamethylene diisocyanate; aziridine compounds described in U.S. Pat. Nos. 3,017,280 and 2,983611; U.S. Pat. No. 3,100,704 Carboximide compounds as described above; Epoxy compounds such as glycerol triglycidyl ether; Ethyleneimino compounds such as 1,6-hexamethylene-N, N′-bisethyleneurea; Halogens such as mucochloric acid and mucophenoxycyclolic acid Carboxaldehyde compounds; Dioxane compounds such as 2,3-dihydroxydioxane; Metal-containing compounds such as titanium lactate, aluminum sulfate, chromium alum, potash alum, zirconyl acetate, chromium acetate, and polyamines such as tetraethylenepentamine And a low molecular weight or polymer containing two or more oxazoline groups, such as a amine compound, a hydrazide compound such as adipic acid dihydrazide.
The said crosslinking agent may be used individually by 1 type, and may be used in combination of 2 or more type.

  Crosslinking curing is performed by adding a crosslinking agent to at least one of a coating solution (coating solution A) containing fine polymer particles, a water-soluble resin, and the like, and (1) applying the coating solution. When the layer is formed, or (2) when the coating layer formed by applying the coating solution is in the middle of drying and before the coating layer exhibits reduced-rate drying, the basic pH of 8 or more It is preferable to carry out by applying a solution (coating liquid B) to the coating layer.

There is no restriction | limiting in particular as a method of mixing the foam of said (3), or adding a foaming agent and forming the polymer layer which has a porous structure, According to the objective, it can select suitably, As said foaming agent Can be appropriately selected from known foaming agents according to the purpose, and for example, a carbon dioxide generating compound, a nitrogen gas generating compound, an oxygen gas generating compound, a microcapsule type foaming agent, and the like are preferable. .
Examples of the carbon dioxide generating compound include bicarbonates such as sodium bicarbonate.
Examples of the nitrogen gas generating compound include a mixture of NaNO ₂ and NH ₄ Cl; an azo compound such as azobisirobutyronitrile and diazoaminobenzene; p-diazodimethylaniline chloride zinc chloride, morpholinobenzenediazonium chloride zinc chloride. , Morpholinobenzenediazonium chloride, fluoroborate, p-diazoethylaniline chloride zinc chloride, 4- (p-methyl-benzoylamino) -2,5-diethoxybenzenediazonium zinc chloride, 1,2diazonaphthol-5-sulfone And diazonium salts such as sodium acid salts.
Examples of the oxygen gas generating compound include peroxides.
Examples of the microcapsule-type foaming agent include microcapsule particle foaming agents that contain a low-boiling substance that vaporizes at a low temperature (which may be in a liquid state or a solid state at room temperature). Examples of the microcapsule type foaming agent include a microcapsule wall material made of polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic ester, polyacrylonitrile, polybutadiene, or a copolymer thereof. For example, a microcapsule having a diameter of 10 to 20 μm encapsulated with a low boiling point vaporizable substance such as propane, butane, neopentane, neohexane, isopentane, or isobutylene.
The content of the foaming agent in the polymer layer varies depending on the type of the foaming agent and cannot be specified unconditionally, but is usually preferably 1 to 50% by mass.

  In the present invention, as described above, it is preferable that the polymer layers other than the outermost polymer layer have voids. The polymer layer other than the outermost polymer layer is preferably a polymer layer immediately below the outermost surface polymer layer, and the immediately lower layer may be a toner image receiving layer, but an undercoat layer is particularly preferable.

The outermost surface polymer layer contains a water-based polymer, and further contains other components as necessary.
The water-based polymer is not particularly limited with respect to its composition, bond structure, molecular structure, molecular weight, molecular weight distribution, form, and the like as long as it is any one of a water-dispersible polymer and 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.

Examples of the water dispersible polymer include (1) polyolefin resin, (2) polystyrene resin, (3) acrylic resin, (4) polyvinyl acetate or a derivative thereof, (5) polyamide resin, (6 ) Polyester resins, (7) Polycarbonate resins, (8) Polyether resins (or acetal resins), (9) Other resins, water-dispersed thermoplastic resins and emulsions, copolymers and mixtures thereof, And it can select suitably from a cation modified substance, and can combine 2 or more types.
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 Polymer Co., Ltd., and Jurimer ET series manufactured by Nippon Pure Chemical Co., Ltd.

The water dispersible emulsion is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a water dispersible polyurethane emulsion, a water dispersible polyester emulsion, a chloroprene emulsion, a styrene-butadiene emulsion, a nitrile- Butadiene emulsion, butadiene emulsion, vinyl chloride emulsion, vinylpyridine-styrene-butadiene emulsion, polybutene emulsion, polyethylene emulsion, vinyl acetate emulsion, ethylene-vinyl acetate emulsion, vinylidene chloride emulsion, methyl methacrylate Examples thereof include butadiene-based emulsions. Among these, a water-dispersible polyester emulsion is particularly preferable.
The water-dispersible polyester emulsion is preferably a self-dispersing polyester emulsion, and among them, a carboxyl group-containing self-dispersing polyester resin emulsion is particularly preferable. Here, the self-dispersing polyester emulsion means an aqueous emulsion containing a polyester resin that can be self-dispersed in an aqueous solvent without using an emulsifier or the like. The carboxyl group-containing self-dispersing polyester resin emulsion means an aqueous emulsion containing a polyester resin that contains a carboxyl group as a hydrophilic group and 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. Furthermore, since a polyester resin having a high cohesive energy and a molecular structure is used, it has a sufficient hardness in the storage environment, but becomes a low elasticity (low viscosity) molten state in the electrophotographic fixing process, and the toner is polymer. Sufficient image quality can be achieved by embedding in the layer.
(1) The number average molecular weight (Mn) is preferably 5,000 to 10,000, and more preferably 5,000 to 7,000.
(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, and more preferably 50 to 80 ° C.
(4) The volume average particle diameter is preferably 20 to 200 nm, more preferably 40 to 150 nm.
The content of the water-dispersible emulsion in the polymer layer is preferably 10 to 90% by mass, and more preferably 10 to 70% by mass.

There is no restriction | limiting in particular as said water-soluble polymer, According to the objective, it can select suitably, What was synthesize | combined suitably may be used and a commercial item may be used, for example, polyvinyl alcohol, carboxy Modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, cellulose sulfate, polyethylene oxide, gelatin, cationized starch, casein, sodium polyacrylate, sodium styrene-maleic anhydride copolymer, sodium polystyrene sulfonate, etc. Among these, polyethylene oxide is preferable.
Commercially available water-soluble polymers include water-soluble polyester plus 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 & Chemicals Finetex 6161, K-96; Seiko Chemical Industries high loss NL-1189, BH-997L, and the like.
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.

  There is no restriction | limiting in particular in content in the said polymer layer of the said water-soluble polymer, According to the objective, it can select suitably, 0.5-10 mass% is preferable.

In the present invention, it is preferable to have a support, at least one undercoat layer on the support, and at least one toner image-receiving layer on the undercoat layer. In this case, the outermost polymer layer is a toner image-receiving layer. It is preferable that the undercoat layer which is a layer and is a polymer layer other than the outermost polymer layer has voids.
Hereinafter, the undercoat layer and the toner image receiving layer will be described.

(Undercoat layer)
As described above, the undercoat layer has voids, and contains a polymer and, if necessary, other components.
There is no restriction | limiting in particular as said polymer, Although it can select suitably according to the objective, A water-based polymer is suitable. Examples of the water-based polymer include those similar to the polymer layer.
The undercoat layer may optionally contain other components such as a release agent, a plasticizer, a filler, a cross-linking agent, a charge control agent, an emulsifier, and a dispersant, as long as the function of the undercoat layer is not impaired. it can.

  The undercoat layer is formed, for example, by preparing a coating solution for an undercoat layer and coating the coating solution on a support. The coating method is not particularly limited and may be appropriately selected depending on the purpose. For example, blade coating method, air knife coating method, gravure coating method, roll coating coating method, spray coating method, dip coating method, bar Examples thereof include a coating method, an extrusion coating method, and a spin coating method.

  There is no restriction | limiting in particular in the thickness of the said undercoat, According to the objective, it can select suitably, For example, 1-50 micrometers is preferable and 3-20 micrometers is more preferable.

[Toner image receiving layer]
The toner image receiving layer is a layer that receives color toner and black toner and forms an image. The toner image-receiving layer has a function of receiving toner that forms an image from a developing drum or an intermediate transfer body by (static) electricity, pressure, or the like in a transfer process, and fixing it by heat, pressure, or the like in a fixing process. Have.

  As described above, the toner image-receiving layer contains at least the water-based polymer and, if necessary, a release agent, a plasticizer, a colorant, a filler, a crosslinking agent, a charge control agent, an emulsifier, a dispersant, and the like. It contains other components.

-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 is heated and melted at a 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 a release agent material on the surface of the toner image-receiving layer. As long as the layer is formed, the type is not particularly limited and can be appropriately selected depending on 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 can also be preferably used. 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 thereof 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 preferable. 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 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 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 of the natural wax is preferably 70 to 95 ° C., 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.

  Examples of the matting agent include various known ones. Solid particles used as a matting agent can be classified into inorganic particles and organic particles. Specific examples of the material for the inorganic matting agent include oxides (for example, silicon dioxide, titanium oxide, magnesium oxide, aluminum oxide), alkaline earth metal salts (for example, barium sulfate, calcium carbonate, magnesium sulfate), halogens Examples include silver halide (eg, silver chloride, silver bromide) and glass.

  Examples of the inorganic matting agent include West German Patent No. 2529321, British Patent No. 760775, No. 1260772, U.S. Patent Nos. 1201905, No. 2192241, No. 3053662, No. 3062649, No. 3257206. No. 3322555, No. 3353958, No. 3370951, No. 3411907, No. 3437484, No. 3523022, No. 3615554, No. 3635714, No. 3769020, No. 40212245 And those described in each specification of No. 4029504.

The material of the organic matting agent includes starch, cellulose ester (for example, cellulose acetate propionate), cellulose ether (for example, ethyl cellulose) and synthetic resin. The synthetic resin is preferably water-insoluble or poorly water-soluble. Examples of water-insoluble or poorly water-soluble synthetic resins include poly (meth) acrylic acid esters (for example, polyalkyl (meth) acrylate, polyalkoxyalkyl (meth) acrylate, polyglycidyl (meth) acrylate), and poly (meth). Includes acrylamide, polyvinyl ester (eg, polyvinyl acetate), polyacrylonitrile, polyolefin (eg, polyethylene), polystyrene, benzoguanamine resin, formaldehyde condensation polymer, epoxy resin, polyamide, polycarbonate, phenol resin, polyvinyl carbazole, polyvinylidene chloride, etc. It is.
You may use the copolymer which combined the monomer used for the above polymer.

In the case of the copolymer, a small amount of hydrophilic repeating units may be contained. 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 and styrene sulfonic acid.
Examples of the organic matting agent include British Patent No. 1055713, U.S. Patent No. 1,939,213, No. 2221873, No. 2,226,662, No. 2322037, No. 2376005, No. 2391181, No. 2701245, Nos. 2,921,101, 3,079,257, 3,262,782, 3,443,946, 3,516,832, 3,539,344, 3,591,379, 3,754,924, 3,767,448 Examples thereof include those described in Japanese Utility Model Publication Nos. 49-106821 and 57-14835.
Two or more kinds of solid particles may be used in combination. The average particle size of the solid particles is, for example, preferably 1 to 100 μm, and more preferably 4 to 30 μm. The amount of the solid particles is preferably ^{0.01~0.5g / m 2, 0.02~0.3g / m} 2 is more preferable.

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.
As the releasing agent added to the toner image-receiving layer, derivatives, oxides, purified products, and mixtures thereof 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 the adhesion resistance may be insufficient. When the content exceeds 10% by mass, the amount of the release agent is too 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 -Theory and Application-" (written by Koichi Murai, Koshobo), "Research on plasticizer", "Research on plasticizer" “Lower” (edited by Polymer Chemistry Association), “Handbook Rubber / 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 phthalic acid esters, phosphoric acid 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.

Furthermore, a polymer having a relatively low molecular weight can be used as the plasticizer. 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, may be in a micro-phase-separated state in a sea-island shape, or may be in a sufficiently mixed and dissolved state 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, Although it can select suitably according to the objective from well-known things, 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 (for example, carmine 6B, red 2B, etc.), insoluble azo pigment (for example, monoazo yellow, disazo yellow, pyrazolo orange, vulcan orange), and condensed azo pigment (for example, chromophthal yellow). And chromophthaled red).
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 (eg, dioxazine violet), isoindolinone pigments (eg, isoindolinone yellow), selenium pigments, perylene pigments, perinone pigments, thioindigo pigments. And pigments.
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.

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 Fundamentals 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 to precipitate 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 preferably contains a charge adjusting agent in order to adjust transfer or adhesion of toner or to prevent charging adhesion of the toner image receiving layer.
The charge control agent is not particularly limited, and various conventionally known charge control agents can be appropriately used according to the purpose. For example, a cationic surfactant, an anionic surfactant, an amphoteric surfactant, In addition to surfactants such as nonionic surfactants, polymer electrolytes, conductive metal oxides, 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
In the case where the toner has a negative charge, for example, a cation or a nonion is preferable as the charge adjusting agent 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 with} respect to SnO ₂ . Can contain (doping) Sb, Nb, a halogen element, or the like.

-Other additives-
The material that can be used for the toner image-receiving layer may 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 phenolic compound (for example, hindered phenol etc.), a hydroquinone derivative, a hindered amine derivative, a spiroindane compound Is 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) Benzophenone compounds (see Japanese Patent Application Laid-Open No. Sho 46-2784) and ultraviolet absorbing polymers (see Japanese Patent Application Laid-Open No. Sho 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.

  Note that, as described above, known photographic additives can be added to the material that can be used for the toner image-receiving layer, 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 is provided by applying a coating solution 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.

The toner image-receiving layer, 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 intended purpose. For example, it is preferably 1/2 or more of the particle diameter of the toner used, and is 1 to 3 times thicker. 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%. Furthermore, 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%.
As the whiteness, specifically, 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 metallic luster, which is not preferable as 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 amount of toner when the toner is transferred to the toner image-receiving layer is not sufficient, and the density of the resulting toner image may tend 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.

<Support>
The support is not particularly limited and can be appropriately selected according to the purpose from those known as a support for an electrophotographic image-receiving sheet. For example, a base paper, a synthetic paper, a synthetic resin sheet, a coat Examples thereof include paper and laminated paper. Among these, coated paper having a polyolefin resin layer on both sides of the base paper is particularly preferable. These supports may have a single layer structure or a laminated structure of two or more layers.

-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 in 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 preferred, softwood bleached kraft pulp (NBKP), hardwood sulfite pulp (LBSP) and the like can also be used.
A beater, refiner, or the like can be used for beating the pulp.
The Canadian standard freeness of the pulp can control the shrinkage of the paper in the paper making process, so 200-440 ml C.I. S. F. Is more preferred, 250-380 ml C.I. S. F. Is more preferable.
In the pulp slurry obtained after beating the pulp (hereinafter sometimes referred to as “pulp paper material”), various additives such as a filler, a dry paper strength enhancer, a sizing agent, A wet paper strength enhancer, a fixing agent, a pH adjuster, and other agents are added.

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 higher fatty acid salts; rosin derivatives such as rosin and maleated rosin; paraffin wax, alkyl ketene dimer, alkenyl succinic anhydride (ASA); and compounds containing higher fatty acids such as epoxidized fatty acid amide, Etc.
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, an optical brightener, 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 contains pulp paper stock containing the above-mentioned various additives, such as a paper machine, a long paper machine, a round paper machine, a twin wire machine, a combination machine, and the like. It is used to make paper and then dried to produce a base paper. Moreover, surface sizing treatment can be performed either before or after the drying as desired.
The treatment liquid used for the surface sizing treatment is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include water-soluble polymer compounds, water-resistant substances, pigments, dyes, fluorescent whitening agents, and the like. May be included.
Examples of the water-soluble polymer compound include cationized starch, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, cellulose sulfate, gelatin, casein, sodium polyacrylate, styrene-maleic anhydride copolymer sodium. Salt, sodium polystyrene sulfonate, and the like.

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. When the Ea / Eb value is less than 1.5 or more than 2.0, the rigidity and curl property of the heat-sensitive recording material are liable to be deteriorated, and the running property during conveyance may be hindered.

In general, it is known that the “strain” of paper differs based on the difference in the mode of beating. After beating, the elastic force (rate) of the paper made after paper beating is an important indicator of the degree of “strain” of the paper. 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 said numerical formula, E means a 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.

  In order to impart a desired centerline average roughness to the surface of the base paper, for example, as described in JP-A-58-68037, a fiber length distribution (for example, a 24 mesh screen residue and , 42 mesh screen residue is, for example, preferably 20 to 45 mass% and 24 mesh screen residue is 5 mass% or less). Further, the center line average roughness can be adjusted by applying heat and pressure to the surface with a machine calendar, a super calendar, or the like.

There is no restriction | limiting in particular in the thickness of the said base paper, According to the objective, it can select suitably, 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 suitably selected according to the purpose, for example, preferably ^{50~250g / m 2, 100~200g / m} 2 is more preferable.

-Synthetic paper-
The synthetic paper is paper mainly composed of polymer fibers other than cellulose, and examples of the polymer fibers include polyolefin fibers such as polyethylene and polypropylene.

-Synthetic resin sheet (film)-
Examples of the synthetic resin sheet (film) include those obtained by molding a synthetic resin into a sheet, and examples thereof include a polypropylene film, a stretched polyethylene film, a stretched polypropylene film, a polyester film, a stretched polyester film, and a nylon film. . Moreover, the film made white by extending | stretching, the white film containing a white pigment, etc. can also be used.

-Coated paper-
The coated paper is paper obtained by applying various resins to at least one of both sides and both sides of a base such as base paper, and the coating amount varies depending on the application. Examples of such coated paper include art paper, cast coated paper, Yankee paper, and the like.

  There is no restriction | limiting in particular as resin applied to the surface of the said base paper etc., Although it can select suitably according to the objective, A thermoplastic resin is suitable. The thermoplastic resin includes (1) polyolefin resin, (2) polystyrene resin, (3) acrylic resin, (4) polyvinyl acetate or a derivative thereof, (5) polyamide resin, and (6) polyester resin. , (7) polycarbonate resin, (8) polyether resin (or acetal resin), (9) other resins, and the like. These thermoplastic resins may be used individually by 1 type, and may use 2 or more types together.

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 olefin and other vinyl monomer include ethylene-vinyl acetate copolymer, ionomer resin that is a copolymer of acrylic acid and methacrylic acid, and the like. 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. The characteristics of the polyacrylic acid esters and polymethacrylic acid esters vary greatly depending on the type of ester group. Moreover, the copolymer with other monomers (For example, acrylic acid, methacrylic acid, styrene, vinyl acetate, etc.) is also mentioned. The polyacrylonitrile is often used as a copolymer of the AS resin and ABS resin rather than a homopolymer.
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 a polycondensate of alcohol and acid, and the characteristics differ greatly depending on the combination. Examples include general-purpose resins polyethylene terephthalate and polybutylene terephthalate composed of an aromatic dibasic acid and a dihydric alcohol.
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 may further contain a pigment, dye, or the like such as a brightening agent, a conductive agent, a filler, titanium oxide, ultramarine blue, or carbon black, if necessary.

-Laminated paper-
The laminated paper is a paper obtained by laminating various materials such as resin, rubber, polymer sheet or film on a base such as a base paper. Examples of the laminate material include polyolefin resin, polyvinyl chloride resin, polyester resin, polystyrene resin, polymethacrylate resin, polycarbonate resin, polyimide resin, and triacetyl cellulose. These resins may be used alone or in combination of two or more.

  In general, the polyolefin resin is often formed by using a low density polyethylene resin. In order to improve the heat resistance of the support, polypropylene, a blend of polypropylene and polyethylene, high density polyethylene, high density polyethylene and low density are used. It is preferable to use a blend with polyethylene. In particular, it is most preferable to use a blend of high-density polyethylene and low-density polyethylene from the viewpoint of cost, suitability for lamination, and the like.

The mixing ratio (mass ratio) of the high-density polyethylene and the low-density polyethylene is preferably 1/9 to 9/1, more preferably 2/8 to 8/2, and still more preferably 3/7 to 7/3. . When the thermoplastic resin layers are formed on both sides of the base paper, the back side of the base paper is preferably formed using, for example, high-density polyethylene or a blend of high-density polyethylene and low-density polyethylene. There is no restriction | limiting in particular as molecular weight of the said polyethylene, According to the objective, it can select suitably, Melt index is between 1.0-40 g / 10min about any of a high density polyethylene and a low density polyethylene. Those having extrudability are preferable.
In addition, you may perform the process which gives white reflectivity to these sheets or films. Examples of such a treatment method include a method of blending a pigment such as titanium oxide in these sheets or films.

  There is no restriction | limiting in particular as thickness of the said support body, It can select suitably according to the objective, 25-300 micrometers is preferable, 50-260 micrometers is more preferable, 75-220 micrometers is still more preferable.

[Other layers]
Examples of other layers in the electrophotographic image-receiving sheet include, for example, a back layer, a surface protective layer, an adhesion improving layer, an intermediate layer, a cushion layer, a charge adjusting (preventing) layer, a reflecting layer, a color adjusting layer, and a storage stability improvement. A layer, an anti-adhesion 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.

-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.
Further, the back layer may have the same structure as that of the toner image receiving layer for improving the duplex output suitability. Various additives described above can be used for the back layer. As such an additive, it is particularly suitable to blend a matting agent, a charge adjusting agent and the like. The back layer may have a single layer configuration or a stacked configuration of two or more layers.
Further, in order to prevent offset at the time of fixing, when a releasable 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.

-Surface protective layer-
The surface protective layer is used for the purpose of protecting the surface of the electrophotographic image-receiving sheet, improving storability, 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 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. 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 provided, 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 Homopolymers 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 can be appropriately selected from those usually used for toner according to the purpose. For example, a relatively low molecular weight highly crystalline polyethylene wax, 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 suitable 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 diisocyanic acid compound include tolylene diisocyanate, 4,4'diphenylmethane, toluene diisocyanate, 1,3-diisocyanate, 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 many 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, a dyno mill or the like 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 include 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 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 is preferably 0.5 μm or more and 10 μm or less.
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.
Further, the volume average particle size range of the toner is preferably satisfied, and the volume average particle size distribution index (GSDv) is preferably 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.
The average value of the shape factor represented by the following formula and satisfying the volume average particle diameter range of the toner 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 has an effect on image quality, particularly graininess and resolution, and it is difficult to cause omission and blur due to transfer, and handling properties are adversely affected even if the average particle size is not small. It becomes difficult.

The storage 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, which improves image quality and offset property in the fixing process. It is appropriate in terms of prevention.

(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 peeling portion and other members as necessary.

There is no restriction | limiting in particular as said heating-pressing member, According to the objective, it can select suitably, For example, a pair of heating roller, the combination of a heating roller and a pressure roller, etc. are mentioned.
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 toner image-receiving layer polymer, and varies depending on the toner image-receiving layer polymer to be used. The cooling temperature in the cooling device is preferably 80 ° C. or less, and more preferably 20 to 80 ° C., at which the 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 material of 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) ), Polyether ether ketone (PEEK), polyether sulfone (PES), polyether imide (PEI), polyparabanic acid (PPA), and the like.

  The release layer preferably contains 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 fluorocarbon siloxane having an ≡SiH group content of 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.

In addition, the fluorocarbon having an ≡SiH group may be 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 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, diphenylsilane diol, low-polymerization degree molecular chain terminal hydroxyl-blocked dimethylpolysiloxane, dispersant such as hexamethyldisilazane, heat resistance improver such as ferrous oxide, ferric oxide, cerium oxide, 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 support film is not particularly limited, but is preferably 1 to 200 μm in order to obtain good image fixability by preventing toner releasability or toner component offset. 5 to 150 μm is more preferable.

Here, an example of the belt fixing device in the image forming apparatus of the present invention 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 to melt and move 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 and fixing processor as shown in FIG. 3 is modified as a fixing unit of the electrophotographic apparatus shown in FIG. 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, the color toner image is transferred onto the surface, and the fixed electrophotographic transfer sheet is transferred to the heating roll 71 and the heating roll 71 with an endless belt. The color toner image is introduced into a pressure contact portion (nip portion) with the pressure roll 72 that is pressure-contacted via 73 so that the color toner image is positioned on the heating roll 71 side, and the pressure contact portion between the heating roll 71 and the pressure roll 72. The color toner image is heated and melted and fixed on the electrophotographic image-receiving sheet during the passage of the toner.

  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. In addition, it is possible to form a high-quality image similar to a silver salt photographic print.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example at all.

Example 1
<Preparation of support>
High-quality paper with a basis weight of 160 g / m ² is used as a base paper, and a blend of high-density polyethylene (HDPE) and low-density polyethylene (LDPE) with a mass ratio (HDPE / LDPE) of 7/3 is extruded on the back side of the base paper. A backside polyethylene layer having a thickness of 15 μm was formed by a coating method (310 ° C.). On the other hand, a surface polyethylene layer having a thickness of 31.7 μm was formed by extruding LDPE onto the opposite surface (front surface) of the base paper by a coating method (310 ° C.).

<Preparation of titanium dioxide dispersion>
The following components were mixed and dispersed using NBK-2 manufactured by Nippon Seiki Seisakusho to prepare a titanium dioxide dispersion.
-Titanium dioxide (R-780-2, manufactured by Ishihara Sangyo Co., Ltd.) ... 48 parts by mass-Polyvinyl alcohol (PVA205C, manufactured by Kuraray Co., Ltd.)-40 parts by mass-Surfactant (Demol EP, Kao Corporation) Manufactured) ... 0.6 parts by mass ・ Ion-exchanged water ... 31.6 parts by mass

Next, the following components were mixed to prepare an undercoat layer coating solution. The obtained undercoat layer coating solution was coated on the front surface of the support with a bar coater so that the dry resin coating amount was 10 g / m ² (thickness 15 μm). Next, drying was performed at 90 ° C. for 5 minutes.

<Composition of undercoat layer coating solution>
・ Urethane resin aqueous dispersion (Takelac W6020, manufactured by Mitsui Takeda Chemical Co., Ltd.) ... 250 parts by mass = 1 μm) ··· 566 parts by mass · Polyethylene oxide (Alcox R1000, manufactured by Meisei Chemical Co., Ltd.) · · 4 parts by mass · Anionic surfactant (Lapisol A90, manufactured by Nippon Oil & Fats Co., Ltd.) 6 parts by mass Water: 94.4 parts by mass

Next, the following components were mixed to prepare a toner image-receiving layer coating solution. The obtained toner image-receiving layer coating solution was coated on the surface of the undercoat layer with a bar coater so that the dry resin coating amount was 5.5 g / m ² (thickness 7 μm). Next, drying was performed at 90 ° C. for 3 minutes. Thus, an electrophotographic image receiving sheet of Example 1 was produced.
<Composition of toner image-receiving layer coating solution>
-Polyester resin aqueous dispersion (solid content 35% by mass, trade name KA7276C, manufactured by Unitika Ltd., number average molecular weight = 6,000) ... 200 parts by mass-water ... 128.7 parts by mass-Titanium dioxide 15.5 parts by mass of Carnauba wax aqueous dispersion (Cerosol 524, manufactured by Chukyo Yushi Co., Ltd.) ... 10 parts by mass of polyethylene oxide (Alcox R1000, manufactured by Meisei Chemical Co., Ltd.) ·· 4.8 parts by mass · Anionic surfactant (Lapisol A90, manufactured by NOF Corporation) ··· 1.5 parts by mass · Matting agent (XX08S, manufactured by Sekisui Chemical Co., Ltd.) ··· .8 parts by mass

(Example 2)
In Example 1, except that the hollow particle aqueous dispersion in the undercoat layer coating liquid was changed to Ropaque HP433J (manufactured by Nippon Zeon Co., Ltd., porosity = 33% by volume, volume average particle size = 0.5 μm), Example 1 In the same manner as above, an electrophotographic image-receiving sheet was produced.

(Example 3)
In Example 1, the hollow particle aqueous dispersion in the undercoat layer coating solution was SX866 (manufactured by JSR Corporation, porosity = 33% by volume, volume average particle size = 0.5 μm), and the resin used was an acrylic resin (XE240, An electrophotographic image-receiving sheet was prepared in the same manner as in Example 1 except that a mixture of Starlight Polymer Co., Ltd.) and an acrylic resin (PDX7325, Johnson Polymer Co., Ltd.) was mixed at a mass ratio of 5: 5. Produced.

Example 4
In Example 1, except that 1 part by mass of a hollow particle aqueous dispersion (Ropaque HP1055, manufactured by Nippon Zeon Co., Ltd., porosity = 55% by volume, volume average particle size = 1 μm) was added to the toner image-receiving layer coating solution. In the same manner as in Example 1, an electrophotographic image-receiving sheet was produced.

(Example 5)
Vapor phase silica fine particles and ion-exchanged water having the following composition are mixed and dispersed using a high-speed rotating colloid mill (CL Technique, manufactured by M Technique Co., Ltd.) at a rotational speed of 10,000 rpm for 20 minutes. Thus, an inorganic fine particle dispersion was prepared. A solution containing the following polydimethyldiallylammonium chloride, polyvinyl alcohol, boric acid, polyoxyethylene lauryl ether, and ion-exchanged water is added to the obtained inorganic fine particle dispersion, and again at a rotational speed of 10,000 rpm for 20 minutes. Dispersion was performed to prepare a porous layer coating solution A.

<Composition of porous layer coating liquid A>
Vapor phase silica fine particles (inorganic fine particles, Leolosil QS30, average primary particle size 7 nm, manufactured by Tokuyama Corporation) ... 10.0 parts by mass Ion-exchanged water ... 51.7 parts by mass Polydimethyldiallylammonium chloride (Dispersant, Charol DC902P, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.49 parts by mass Polyvinyl alcohol (water-soluble resin, PVA124, saponification degree 98.5%, polymerization degree 2400, manufactured by Kuraray Co., Ltd.) 27.8 parts by mass Boric acid (crosslinking agent) 0.4 parts by mass Polyoxyethylene lauryl ether (surfactant, Emulgen 109P (10% by mass aqueous solution), HLB value 13.6, Kao Corporation Made by company) ... 1.2 parts by mass · Ion exchange water ... 33.0 parts by mass

<Composition of porous layer coating liquid B>
・ Boric acid (crosslinking agent): 0.65 parts by mass ・ Polyallylamine (PAA-10C (10 mass% aqueous solution), mordant, manufactured by Nittobo Co., Ltd.): 25 parts by mass ・ Ion exchange water: 59.7 parts by mass Ammonium chloride (surface pH adjuster) 0.8 parts by mass Polyoxyethylene lauryl ether (surfactant, Emulgen 109P (10% by mass aqueous solution), HLB value 13.6, Kao Corporation (Made by company) ··· 10 parts by mass · Fluorosurfactant (Megafac F1405 (10% by mass aqueous solution), manufactured by Dainippon Ink & Chemicals, Inc.) ··· 2.0 parts by mass

Next, after performing corona discharge on the front surface of the support, the porous layer coating solution A was applied to the front surface of the support using an extrusion die coater at a rate of 100 ml / m ² . The coating layer was dried at 80 ° C. (wind speed of 3 to 8 m / sec) with a hot air dryer until the solid content concentration of the coating layer became 20% by mass. This coating layer showed constant rate drying during this period. Immediately after that, it was immersed in the porous layer coating solution B having the above composition for 30 seconds to deposit 10 g / m ² on the coating layer. Furthermore, it was dried at 80 ° C. for 10 minutes (drying step). This provided a porous polymer layer with a dry thickness of 16 μm. An electron micrograph of the obtained porous polymer layer is shown in FIG. The pore size of this porous polymer layer was 30 to 50 nm, and the porosity was 60% by volume.
Next, a toner image-receiving layer was formed on the porous polymer layer in the same manner as in Example 1. Thus, an electrophotographic image receiving sheet of Example 5 was produced.

(Example 6)
In Example 1, the hollow particle aqueous dispersion was removed from the undercoat layer coating solution, and the hollow particle aqueous dispersion (Ropaque HP1055, manufactured by Nippon Zeon Co., Ltd., porosity = 55 vol%, volume average particle size) was added to the toner image-receiving layer coating solution. = 1 μm), an electrophotographic image-receiving sheet was prepared in the same manner as in Example 1 except that 1 part by mass was added.

(Comparative Example 1)
In Example 1, an electrophotographic image-receiving sheet was produced in the same manner as in Example 1 except that the hollow particle aqueous dispersion was removed from the undercoat layer coating solution.

(Comparative Example 2)
A toner image-receiving layer coating solution having the following composition was prepared. The obtained toner image-receiving layer coating solution was coated on the front surface of the same support as in Example 1 with a bar coater so that the dry resin coating amount was 10 g / m ² (thickness 16 μm). Subsequently, drying was performed at 90 ° C. for 5 minutes to prepare an electrophotographic image receiving sheet.
<Composition of toner image-receiving layer coating solution>
-Polyester resin aqueous dispersion (solid content 30% by mass, trade name KA7276C, manufactured by Unitika Ltd., number average molecular weight = 6,000) ... 200 parts by mass-water ... 128.7 parts by mass-Titanium dioxide Dispersion: 15.5 parts by mass Carnauba wax aqueous dispersion (Cerosol 524, manufactured by Chukyo Yushi Co., Ltd.): 10 parts by mass Polyethylene oxide (Alcox R1000, manufactured by Meisei Chemical Co., Ltd.): 4 .8 parts by mass ・ Hollow particle aqueous dispersion (Ropeke HP 1055, manufactured by Nippon Zeon Co., Ltd., hollow ratio = 55%, volume average particle diameter = 1 μm)... 130 parts by mass ・ Matting agent (XX08S, Sekisui Chemical Co., Ltd.) Manufactured) ... 1.8 parts by mass

<Image formation>
For each of the obtained electrophotographic image-receiving sheets, in the image forming apparatus (DocuCenter Color 500CP) manufactured by Fuji Xerox Co., Ltd. as shown in FIG. Using a modified image forming device, print a uniform 18cm square image with the maximum density of black at 25 ° C and 50% RH under the following conditions. After printing, fix it with the printed surface facing up Went.

−Belt−
Belt support: polyimide (PI) film, width = 50 cm, thickness = 80 μm
Belt release layer material: SIFEL610 (manufactured by Shin-Etsu Chemical Co., Ltd.), a fluorocarbonsiloxane rubber precursor, was vulcanized and cured to form a fluorocarbonsiloxane rubber layer having a thickness of 50 μm.
-Heating and pressing process-
Heating roller temperature: 120 ° C
Nip pressure: 130 N / cm ²
-Cooling process-
Cooler: Heat sink length = 80mm
Speed: 20mm / sec
Temperature: 70 ° C

<Evaluation of crack resistance>
The formed black solid image was cut into a size of 3 cm × 10 cm and conditioned for 16 hours in an environment of 10 ° C. and 15% RH. The obtained sample was wound around a rod having a diameter of 20 mm, and the degree of surface cracking was evaluated according to the following criteria. The results are shown in Table 2.
〔Evaluation criteria〕
○: No cracks are visually observed.
X: A crack can be visually observed.

<Blister evaluation>
The heating temperature of the image surface smoothing fixing processor was increased, and the temperature at which blisters (bubbles) were generated on the image surface was evaluated. The results are shown in Table 2.

<Evaluation of void>
The heating temperature of the image surface smoothing fixing processor was lowered, and the temperature at which a void (fixing failure) occurred at the boundary between the image area and the non-image area was evaluated. The results are shown in Table 2.

<Evaluation of fixing latitude>
From the evaluation results of the voids and the blisters, the fixing temperature latitude was evaluated according to the following criteria. The results are shown in Table 2.
〔Evaluation criteria〕
A: A latitude exceeding 10 ° C. is secured.
X: The latitude exceeding 10 degreeC is not ensured.

The electrophotographic image-receiving sheet of the present invention can achieve both excellent crack resistance and fixing property, can form a high-quality image, 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. In addition to realizing paper feeding, it has excellent crack resistance and fixing properties, and can form high-quality images similar to silver salt photographic prints.

FIG. 1 is a schematic view showing an example of an image surface smoothing fixing processor according to 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 view showing an example of an image surface smoothing and fixing processor in the image forming apparatus of FIG. FIG. 4 is an electron micrograph of the porous polymer layer produced in Example 5.

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 portion)
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 (12)

  An electrophotographic image-receiving sheet comprising a support and at least two polymer layers on the support, wherein at least one of the polymer layers has a gap.   The electrophotographic image-receiving sheet according to claim 1, wherein a polymer layer other than the outermost polymer layer in the polymer layer has voids.   The electrophotographic image-receiving sheet according to any one of claims 1 to 2, wherein the support has a base paper and a polyolefin resin layer on both sides of the base paper.   The electrophotographic image-receiving sheet according to any one of claims 1 to 3, wherein the voids are formed by hollow particles contained in the polymer layer.   The electrophotographic image-receiving sheet according to any one of claims 1 to 3, wherein the voids are formed by fine particles contained in the polymer layer.   The image receiving sheet for electrophotography according to any one of claims 2 to 5, wherein the porosity of the polymer layer having voids other than the outermost polymer layer is 30% by volume or more.   The electrophotographic image-receiving sheet according to any one of claims 2 to 6, wherein the outermost surface polymer layer contains an aqueous polymer.   The electrophotographic image-receiving sheet according to claim 7, wherein the aqueous polymer contains a water-dispersible polyester emulsion.   The electrophotographic image-receiving sheet according to claim 8, wherein the water-dispersible polyester emulsion is a self-dispersing water-dispersible polyester emulsion. The electrophotographic image-receiving sheet according to claim 9, wherein the self-dispersing water-dispersible polyester emulsion satisfies the following characteristics (1) to (4).
(1) Number average molecular weight (Mn) = 5000 to 10,000
(2) Molecular weight distribution (weight average molecular weight / number average molecular weight) ≦ 4
(3) Glass transition temperature (Tg) = 40-100 ° C.
(4) Volume average particle diameter = 20 to 200 nm A toner image forming step of forming a toner image on an electrophotographic image-receiving sheet comprising a support and at least two polymer layers on the support, wherein at least one of the polymer layers has voids;
An image surface smoothing and fixing step of smoothing the surface of the toner image formed by the toner image forming 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.