JP2007241041A - Electrophotographic image receiving material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic image receiving material which has satisfactory photolike luster and smoothness, has high photolike image density, and further has print quality superior in pellicle quality such as flaw resistance and scuff resistance after printing. <P>SOLUTION: The electrophotographic image receiving material having a toner receiving layer on a base has a heat insulating layer, formed of at least one layer of hollow particles and particles of thermoplastic resin of ≥0.1 μm in mean particle size and 40 to 140°C in softening point, between the base and toner receiving layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic image-receiving material, and more specifically, it is possible to obtain a photo-like print having excellent color development, glossiness and smoothness, and excellent print quality without using a special secondary fixing process. The present invention relates to an electrophotographic image receiving material.

  Plain paper has been used for electrophotographic image formation, but with the spread and development of multicolor and full-color image formation technology using polymerized toner and printing equipment, high-quality multicolor full-color image formation electronic Photographic paper has been developed. In recent years, there has been a growing demand for photo-like prints comparable to silver halide photographic prints and inkjet output prints, but satisfactory electrophotographic output prints have not yet been obtained.

  Since printing with electrophotographic output uses a toner of several μm in size, the toner fixing part is uneven, has a poor glossiness, and has a limited amount of toner, so the color density is low. These improvements are strongly desired for photo-like output.

  In Patent Document 1, a proposal has been made to improve glossiness by providing an image receiving layer on a resin-coated paper in which both surfaces of a base paper are coated with a resin. However, moisture in the paper is vaporized by heat at the time of fixing and the image receiving paper is removed. It was found that not only the so-called blister resistance, which would swell, was inferior, but also the gloss was insufficient.

  As a method for expressing gloss, Patent Document 2 proposes improvement of gloss by providing a thermoplastic resin layer on coated paper, but gloss and color developability are not sufficient. Further, Patent Documents 3 and 4 propose an image receiving layer in which hollow particles (void particles) are coated on a paper support, but the gloss is insufficient and softens in a specific temperature range according to the present invention. There is no description suggesting the effect of improving relief steps, crease resistance and scratch resistance by using a thermoplastic resin having points.

  In order to solve the above problems, in Patent Documents 5 and 6, toner is obtained by further fixing a belt fixing method after fixing using an image receiving paper in which an image receiving layer is coated on a support having a polyolefin layer on both sides of the base paper. A method for producing gloss by heating and melting and embedding in an image receiving layer is disclosed. However, with such a fixing method, the device becomes large, the device cost increases, and the conveyance speed must be reduced, but a photo-like gloss cannot be obtained.

  Further, Patent Document 7 discloses a method in which after fixing, a film is further embossed or a belt is fixed by a cooling and peeling method to develop gloss. However, when such fixing process is performed twice or more, the device design becomes complicated as the number of processes increases, and there are problems such as poor versatility. There is a demand for a printing technique that can provide a photo-like image with a feeling.

  On the other hand, since the color toner transferred / fixed on the transfer medium is several μm in size, when it is fixed on the electrophotographic image-receiving material, a step is generated between the toner-applied area and the non-image area. The step between the toner fixing portion and the toner non-fixing portion when transferred and fixed in the superposed state is 10 or more μm, and is recognized as a relief image. These phenomena are called relief steps. An image having such a relief step becomes a unique image that appears as if it is lifted up, and it is a print that is far from a photo-like print, so improvement is desired.

In addition, in electrophotographic prints aimed at photo-like images, the highest density is also a problem. In full-color images, sufficient density does not come out due to insufficient toner transfer amount, etc., and in image receiving paper such as general copy paper, toner enters the paper fiber and the density decreases, and the image becomes difficult to see due to irregular reflection on the surface of the image. The present situation is that the density required for the photo-like image has not been obtained.
JP 2002-365826 A Japanese Patent Laid-Open No. 2005-77804 Japanese Patent Laid-Open No. 2002-14485 JP 2003-322993 A JP 2000-66466 A JP 2004-126427 A JP 2005-4038 A

  The object of the present invention is a print having a photo-like gloss and smoothness that can be satisfied by a single fixing, a high photo-like image density, and excellent film quality such as scratch resistance and scratch resistance after printing. It is to provide an electrophotographic image-receiving material having quality.

  The above object of the present invention is achieved by the following configurations.

  1. In an electrophotographic image-receiving material having a toner receiving layer on a support, at least one hollow particle, an average particle size of 0.1 μm or more and a softening point of 40 to 140 are provided between the support and the toner receiving layer. An electrophotographic image receiving material comprising a heat insulating layer made of thermoplastic resin particles at a temperature of ° C.

  2. 2. The electrophotographic image receiving material according to 1, wherein the toner receiving layer contains a thermoplastic resin.

  3. 3. The electrophotographic image receiving material according to 1 or 2, wherein the heat insulating layer has a porosity of 30% or more, and the hollow particles have an outer diameter of 0.3 to 3.0 [mu] m.

  4). The electrophotographic image-receiving material according to any one of 1 to 3, wherein an average outer diameter ratio of the thermoplastic resin particles and the hollow particles of the heat insulating layer is 0.7 to 1.3.

  5. The electrophotographic image-receiving material according to any one of 1 to 4, wherein a mass ratio of the thermoplastic resin and the hollow particles in the heat insulating layer is 10:90 to 50:50.

  According to the present invention, a photo-like gloss and smoothness that can be satisfied by a single fixing, a photo-like high image density, and excellent film quality such as scratch resistance and abrasion resistance after printing. An electrophotographic image-receiving material having quality can be provided.

  In response to the above problems, the constitution of the heat insulating layer containing hollow particles and the toner receiving layer containing a thermoplastic resin promotes melting, crushing, and embedding of toner in the toner receiving layer. In order to further improve glossiness, relief level difference, and film strength, a heat insulating layer is formed of a thermoplastic resin having an average particle diameter similar to that of hollow particles and a softening point of 40 to 140 ° C. It has been found that it is effective to use them together, and to contain a thermoplastic resin in the toner receiving layer which is the upper layer. The reason why the improvement effect is obtained in the present invention is not clear, but the heat insulating effect of the heat insulating layer is lowered by applying the thermoplastic resin particles (emulsion) according to the present invention to the heat insulating layer containing hollow particles. Without melting the toner efficiently, the thermoplastic resin in the heat-insulating layer is melted by the fixing heat and flows between the gaps in the heat-insulating layer, so that a space for embedding the toner can be secured and the relief step is improved. It is thought. Further, it is considered that the film strength of the heat insulating layer containing the hollow particles is improved by cooling and solidifying after the thermoplastic resin is melted, and the scratch resistance of the print is improved.

  By using an electrophotographic image-receiving material having a heat insulating layer comprising a hollow particle and a thermoplastic resin of the present invention and a toner-receiving layer, it has excellent blister resistance and gloss without using a specific secondary fixing device. It is possible to provide an electrophotographic image receiving material having excellent print quality with excellent film strength such as scratch resistance and scratch resistance after printing, as well as excellent relief steps.

  The present invention is described in detail below.

  The electrophotographic image-receiving material used in the present invention is a recording material suitable for an electrophotographic recording system, and has a heat insulating layer and a toner receiving layer on at least one surface on a substrate.

《Insulation layer》
The electrophotographic image receiving material of the present invention is characterized by having a heat insulating layer between the support and the toner receiving layer.

  By providing the heat insulating layer according to the present invention below the toner receiving layer, the diffusion of heat energy applied from a fixing roller or the like at the time of fixing is blocked, and the high temperature state of the toner receiving layer is maintained. Glossy prints can be obtained by dissolving and smoothing the landed toner particles, or by embedding them in the toner receiving layer, and the toner can be melted uniformly to fix the toner even at a low fixing temperature. In addition, the hot offset phenomenon, which is a problem at a high fixing temperature, can be solved by high bleed-out of the wax in the toner, so that a wide fixable temperature range can be obtained.

  In general, the heat insulating layer is a layer containing a constituent material having low thermal conductivity, and includes a method using a resin having low thermal conductivity, or a method using a material containing an air layer or bubbles. In the present invention, a heat insulating layer having a high porosity (void capacity) is preferable.

  The porosity of the heat insulating layer according to the present invention may be 30% or more, preferably 40% or more, particularly preferably 50 to 90%.

  As a material for forming the heat insulating layer having a high porosity defined in the present invention, a foamed plastic, hollow particles or porous particles dispersed in a binder is used.

  Foamable plastic is a hollow plastic filler containing a heat-fusible substance as a shell and containing a low-boiling solvent inside, and foams when heated. Examples of the thermoplastic resin that forms the shell of the plastic filler include polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic acid ester, polyacrylonitrile, polybutadiene, and copolymers thereof. Examples of the blowing agent contained in the shell include propane, isobutane, neopentane, and petroleum ether. For example, there are Micropearl manufactured by Matsumoto Yushi Co., Ltd. and Expandel manufactured by Kemanode.

  As the hollow particles, there are micro hollow bodies formed of various materials such as glass, ceramics, plastics, and the like. As the glass micro hollow bodies, borosilicate glass microspheres, for example, Microsel M. manufactured by Grapavel, Inc. are used. As the aluminosilicate micro hollow body, there is a premix for low foam injection molding and standard injection molding, for example, Fillite manufactured by Nihon Philite.

  When organic hollow particles are used for the heat insulation layer, examples of the hollow particles used in the present invention include thermally expandable hollow particles and capsule-shaped hollow polymers. The heat-expandable hollow particles are hollow particles having a thermoplastic material such as vinylidene chloride-acrylonitrile copolymer as a wall material, and a material containing a heat-expandable gas such as propane, n-butane and isobutane inside the particle. It is. The capsule-shaped hollow polymer is a polymer that uses a resin such as styrene-acrylic as a wall material, contains water therein, and evaporates water during drying to form hollow particles. The hollow particles as described above generally have a particle size of about 0.1 to 100 μm, but the particle size of the hollow particles used in the present invention is preferably 0.2 to 10 μm, more preferably 0.00. 3 to 3 μm. If it is less than 0.3 μm, a sufficient heat insulating effect as hollow particles cannot be obtained, and if it exceeds 10 μm, the smoothness is significantly lowered.

  The particle diameter referred to in the present invention can be determined by a known method, and can be measured using, for example, particle measurement with an electron microscope or a laser diffraction particle size distribution measuring apparatus.

  The hollowness of the hollow particles is a ratio of the outer diameter to the inner diameter of the hollow particles and is expressed by the following formula.

Hollowness (%) = (inner diameter of hollow particles / outer diameter of hollow particles) × 100
Here, the outer diameter / inner diameter of the hollow particles can be determined by particle measurement with an electron microscope.

  The porous particles in the present invention are porous particles having pores on the particle surface, and both inorganic porous particles and organic porous particles can be used.

  The inorganic porous particles are composed of amorphous silica, anhydrous silica, aluminum silicate, magnesium silicate, zinc silicate, calcium silicate, hydrotalcite, zeolite, satin white, titanium oxide, aluminum oxide. , Magnesium oxide, calcium carbonate, calcium sulfate, barium sulfate, diatomaceous earth, kaolin, talc, acidic clay, activated clay, bentonite and the like.

  The organic porous particles used in the present invention may be obtained by an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, or other polymerization methods, or may be obtained by pulverizing a massive porous resin. . The resin component is not particularly limited, for example, polyester resin, methacrylic resin, polycarbonate resin, styrene copolymer resin, vinyl chloride resin, polypropylene resin, and blends thereof. Further, the means for making the resin particles porous or obtaining a porous resin is not particularly limited. Among them, organic porous particles obtained by emulsion polymerization are preferable, and for example, particle aggregate emulsion particles disclosed in JP-A-2-70741 are preferable. Further, the dry structure described in JP-A-5-222108 has one or more through-holes connecting the inside from the surface layer portion of the particles, and the particle diameter is 0.1 to 5.0 μm. More preferably, it is a multilayer structure emulsion particle.

  The particle diameter of the organic porous particles is 0.05 to 50 μm, preferably 0.1 to 20 μm, more preferably 0.2 to 10 μm. If the particle diameter is less than 0.05 μm, it is difficult to make the particles porous. The particle diameter can be measured by the same method as for the hollow particles.

  Whether or not the porous particles are made porous can be apparently seen using an electron microscope or the like, but the degree of porosity can be confirmed by measuring the specific surface area with a mercury porosimeter. it can. Moreover, it can also confirm by the measurement of the oil absorption amount described in JIS K-5101. This utilizes the fact that a larger amount of oil is sucked than non-porous particles of the same component and the same particle size due to the capillary action of pores existing on and inside the particle.

  The heat insulating layer according to the present invention is characterized by comprising thermoplastic resin particles having an average particle diameter of 0.1 μm or more, and includes a thermoplastic resin having a softening point of 40 to 140 ° C. When the softening point is 60 to 110 ° C., the effect of the present invention can be expressed more preferably.

  The thermoplastic resin particles used in the present invention have an average particle size of 0.1 μm or more, preferably 0.2 to 10 μm, more preferably 0.2 to 4 μm. If the thickness is less than 0.1 μm, a sufficient heat insulating effect cannot be obtained, and if it exceeds 10 μm, the smoothness is significantly lowered.

  Moreover, if the average outer diameter ratio of the thermoplastic resin of the heat insulation layer and the hollow particles is 0.7 to 1.3, the relief step improvement which is the effect of the present invention can be improved more preferably.

  The mass ratio of the thermoplastic resin and the hollow particles in the heat insulating layer is preferably 10:90 to 50:50.

In the present invention, the softening point of the thermoplastic resin means that a flow tester (CFT500, manufactured by Shimadzu Corporation) is used. The measurement conditions are a load of 20 kg / cm ² , a nozzle diameter of 1 mm, a nozzle length of 1 mm, and preheating at 80 ° C. When the sample rate of 1 cm ³ (mass represented by true specific gravity × 1 cm ³ ) was measured and recorded for 10 minutes at a heating rate of 6 ° C./min, the plunger drop amount-temperature curve (softening flow curve) of the flow tester When the height of the S-shaped curve at h is h, it means the temperature at h / 2.

Examples of the thermoplastic resin particles used in the heat insulating layer according to the present invention include the following thermoplastic resins.
(A) Polyolefin resins such as polyethylene resins and polypropylene resins, copolymer resins of olefins such as ethylene and propylene and other vinyl monomers, acrylic resins, etc.
(B) Those having an ester bond, such as terephthalic acid, isophthalic acid, maleic acid, fumaric acid, phthalic acid, adipic acid, sebacic acid, azelaic acid, abietic acid, succinic acid, trimellitic acid, pyromellitic acid, etc. Dicarboxylic acid components (these dicarboxylic acid components may be substituted with sulfonic acid groups, carboxyl groups, etc.) and diether derivatives of ethylene glycol, diethylene glycol, propylene glycol, bisphenol A, bisphenol A (for example, bisphenol A Ethylene oxide 2 adducts, propylene oxide 2 adducts of bisphenol A, etc.), bisphenol S, 2-ethylcyclohexyldimethanol, neopentyl glycol, cyclohexyldimethanol, glycerin and other alcohol components (these Polyester resin or polymethacrylic acid ester such as polyester resin, polymethyl methacrylate, polybutyl methacrylate, polymethyl acrylate, polybutyl acrylate, etc. obtained by condensation with a hydroxyl group may be substituted on the alcohol component) Resin, polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, styrene-methacrylate copolymer resin, vinyl toluene acrylate resin, and the like. Specific examples include those described in JP-A Nos. 59-101395, 63-7971, 63-7972, 63-7773, and 60-294862. Commercially available products include Byron 290, Byron 200, Byron 280, Byron 300, Byron 103, Byron GK-140, Byron GK-130, etc. manufactured by Toyobo, Kao's Tufton NE-382, Tufton U-5, ATR- 2009, ATR-2010, etc., Unitika Eritel UE3500, UE3210, XA-8153, etc., Nippon Synthetic Chemical Polyester TP-220, R-188, etc. can be mentioned.
(C) Polyurethane resin, etc.
(D) Polyamide resin, urea resin, etc.
(E) Polysulfone resin, etc.
(F) Polyvinyl chloride resin, polyvinylidene chloride resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl propionate copolymer resin, etc.
(G) Polyol resin such as polyvinyl butyral, cellulose resin such as ethyl cellulose resin, cellulose acetate resin, etc.
(H) Polycaprolactone resin, styrene-maleic anhydride resin, polyacrylonitrile resin, polyether resin, epoxy resin, phenol resin and the like.

  Each of the above thermoplastic resins may be used alone, or two or more of these thermoplastic resins may be mixed and used.

  The thickness of the heat insulating layer according to the present invention is generally 20 μm or more, but is preferably 30 μm or more from the viewpoint of exerting the effects of the present invention, and is preferably 100 μm or less from the viewpoint of productivity.

  If it is 20 μm or less, the heat insulating effect of the present invention is small, and if it is about 50 μm or thicker, the effect is constant. On the other hand, when the thickness is 100 μm or more, problems such as tacking and film peeling occur and handling becomes difficult.

  The binder for dispersing and holding the hollow particles is not particularly limited. For example, styrene-butadiene rubber, styrene-methyl methacrylate-butadiene rubber, acrylic resin, acrylic-styrene resin, acrylic-maleic acid resin, acrylic-vinyl acetate. Resin, emulsion type synthetic resin such as ethylene-vinyl acetate resin, water-soluble polymer such as polyvinyl alcohol, starch, casein, gelatin, carboxymethyl cellulose, polyethylene oxide and the like.

<Toner-receiving layer>
The toner receiving layer according to the present invention is characterized in that it comprises a thermoplastic resin as a main component.

  As the thermoplastic resin applicable to the toner receiving layer according to the present invention, the same thermoplastic resin used for the above-described heat insulating layer can be used.

  The thermoplastic resin of the toner receiving layer may be used alone or in combination of two or more of these thermoplastic resins.

  When coated paper is used as the support described later, the thermoplastic resin to be applied is, in particular, polyethylene, for example, high density polyethylene or low density polyethylene, and also other polyolefins such as polypropylene, polyester, etc. Etc. can be preferably used. These resins may be used in combination.

  The toner receiving layer may be a single layer or may be composed of two or more layers. The film thickness of the thermoplastic resin constituting the toner receiving layer is generally from 0.1 to 50 μm, preferably from 0. 5 to 10 μm.

  The glass transition point of the thermoplastic resin used in the toner receiving layer according to the present invention is 0 ° C. or higher, preferably 20 ° C. or higher, and 35 to 85 ° C. is preferable for sufficiently exhibiting the effects of the present invention. The thermal conductivity is preferably 0.3 W / m · K or less. The thermal conductivity of the thermoplastic resin is, for example, “New edition plastic material reader” (Industry Research Committee, published April 1, 1993, new edition 4 printing), “Plastic molding data book” (Nikkan Kogyo Shimbun, 1988). 1st edition issued in March) and “Plastics Data Book” (Industry Research Committee, issued in December 1999, first edition issued).

  As the thermoplastic resin used in the toner receiving layer according to the present invention, it is preferable to select a resin having high compatibility with the binder resin constituting the toner to be received from the viewpoint that the effects of the present invention can be further exhibited.

  To be compatible with the toner binder resin in the present invention means that the thermoplastic resin of the toner receiving layer and the toner binder resin do not form a boundary in the image after fixing. As a method for evaluating the compatibility of the toner with the binder resin, for example, a method using the solubility parameter described in JP-A-2-263642 is described. As a more appropriate evaluation method, a molten toner is described. A method for measuring the tilt angle can be mentioned.

  As a method for measuring the melted toner inclination angle, after forming a toner disk, the toner receiving layer composed of a thermoplastic resin set to a predetermined temperature is closely contacted with the toner disk, and the toner disk is melted. Rapid cooling and solidification. Using this contact angle measuring device manufactured by Kyowa Interface Chemical Co., Ltd., the angle of the bottom of the toner after the toner is solidified is measured twice, and the average value is taken as the molten toner inclination angle.

  When the thermoplastic resin is selected from the viewpoint of the molten toner inclination angle, it is preferable to use a resin having a toner inclination angle of 40 degrees or less between the toner used for color image formation and the thermoplastic resin. The resin of the transparent resin layer having a molten toner inclination angle of 40 degrees or less includes polyester resin, styrene-acrylic ester resin, epoxy resin, polyurethane resin, polymethyl methacrylate resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer. And other thermoplastic resins. Particularly preferred is a resin of the same type as the main resin of the toner (a resin containing 50% by mass or more based on the binder resin). That is, if the main resin of the toner is a polyester resin, a polyester resin is used as the resin of the toner receiving layer, and if the main resin of the toner is a styrene-acrylic ester resin, a styrene-acrylic ester resin is used as the resin of the toner receiving layer. Is preferred.

  For coating the heat insulating layer and the toner receiving layer on the support, generally known coating apparatuses such as a reverse roll coater, a bar coater, a curtain coater, a die slot coater, and a gravure coater are appropriately used.

<Other additives for toner receiving layer and heat insulating layer>
In addition to the above-described additives, various additives can be used for the toner image-receiving layer or the heat-insulating layer according to the present invention for the purpose of improving the thermodynamic characteristics.

  Such additives can be appropriately selected according to the purpose, for example, plasticizers, fillers, crosslinking agents, charge control agents, conductive agents, pigments, surfactants, dyes, humidity control agents, Matting agents and the like can be mentioned.

  The plasticizer has a function of adjusting the flow or softening of the toner receiving layer by heat or pressure when fixing the toner. Plasticizers include "Chemical Handbook" (edited by the Chemical Society of Japan, Maruzen), "Plasticizers-Theory and Applications-" (written by Koichi Murai, Koshobo), "Research on plasticizers" It can be selected with reference to "Research" (edited by Polymer Chemistry Association) and "Handbook Rubber / Plastic Compounded Chemicals" (edited by Rubber Digest).

  Moreover, as a filler, a well-known thing can be used as a reinforcing agent for resin, a filler, and a reinforcing material, An organic and inorganic filler are preferable. The filler can be selected with reference to "Handbook Rubber / Plastic Compounding Chemicals" (edited by Rubber Digest Co., Ltd.), "New Edition Plastic Compounding Agent Basics and Applications" (Taiseisha), "Filler Handbook" (Taiseisha), etc. it can.

  Examples of the crosslinking agent include an epoxy group, an isocyanate group, an aldehyde group, an active halogen group, an active methylene group, an acetylene group, and other compounds having two or more known reactive groups in the molecule as a reactive group. Further, a compound having two or more groups capable of forming a bond by ionic bond, coordinate bond, or the like is also included. Examples of the crosslinking agent also include known compounds such as coupling agents for resins, curing agents, polymerization agents, polymerization accelerators, coagulants, film-forming agents, film-forming aids, and the like.

  The charge adjusting agent can be used for the purpose of adjusting toner transfer, adhesion, etc., and preventing charging adhesion of electrophotographic receiving paper. As the charge control agent, any of conventionally known antistatic agents and charge control agents can be used. Surfactants such as cationic surfactants, anionic surfactants, amphoteric surfactants and nonionic surfactants In addition, a polymer electrolyte, a conductive metal oxide, and the like can be used.

Examples of the conductive agent include metal oxides such as 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.

  Examples of the pigment include fluorescent whitening agents, white pigments, colored pigments, and dyes for the purpose of improving image quality, particularly whiteness. The fluorescent whitening agent is a compound that has absorption in the near ultraviolet region and emits fluorescence at 400 to 500 nm. Examples of the fluorescent brightener include stilbene compounds, coumarin compounds, biphenyl compounds, benzoxazoline compounds, naphthalimide compounds, pyrazoline compounds, carbostyril compounds, and the like.

  Various known dyes can be used as the dye, and examples thereof include oil-soluble dyes. Examples of oil-soluble dyes include anthraquinone compounds and azo compounds.

The whiteness of the toner-receiving layer according to the present invention is not particularly limited and can be appropriately selected according to the purpose, but is preferably higher. The whiteness is preferably an L ^* value of 80 or more, more preferably 85 or more, and particularly preferably 90 or more in the CIE 1976 (L ^* a ^* b ^* ) color space. The white color is preferably as neutral as possible. As a white color, the value of (a ^* ) ² + (b ^* ) ^{2 in} the L ^* a ^* b ^* space is preferably 50 or less, more preferably 18 or less, and particularly preferably 5 or less.

  The smoothness of the toner receiving layer according to the present invention is not particularly limited and can be appropriately selected according to the purpose, but is preferably higher. As the smoothness, the arithmetic average roughness (Ra) is preferably 3 μm or less, more preferably 1 μm or less, and more preferably 0.5 μm or less in the entire region from white without toner to black having the maximum density. It is particularly preferred. The arithmetic average roughness can be measured based on JIS B 0601, B 0651, and B 0652.

The surface electrical resistance of the toner receiving layer according to the present invention is preferably 1 × 10 ⁶ to 1 × 10 ¹⁵ Ω (25 ° C., 65% RH), and other than the toner receiving layer according to the present invention. The surface electrical resistance in the layer is also preferably 1 × 10 ⁶ to 1 × 10 ¹⁵ Ω (25 ° C., 65% RH condition).

  A matting agent can be added to the toner receiving layer according to the present invention. There is no restriction | limiting in particular as a mat agent, According to the objective, it can select suitably, For example, a solid particle etc. are mentioned. The solid particles can be classified into inorganic particles and organic particles.

  A slipping agent can be added to the toner receiving layer according to the present invention. Examples of the slip agent include various known ones such as higher alkyl sulfate, higher fatty acid higher alcohol ester, carbowax, higher alkyl phosphate ester, silicone compound, modified silicone, curable silicone, and the like. Polyolefin wax, fluorine oil, fluorine wax, carnauba wax, microcrystalline wax, silane compound and the like.

<Support>
As a support according to the present invention, as long as it can withstand the fixing temperature and can satisfy the requirements in terms of smoothness, whiteness, slipperiness, friction, antistatic properties, dents after fixing, etc. There is no restriction in particular, and it can be appropriately selected according to the purpose. In general, “Photographic Engineering Basics-Silver Salt Photography” edited by the Japan Photography Society, published by Corona Co., Ltd. (Showa 54) (223) ) To (240) pages, and photographic supports such as synthetic polymers (films).

  Specific examples of the support include synthetic paper (polyolefin-based, polystyrene-based synthetic paper), high-quality paper, art paper, (double-sided) coated paper, (double-sided) cast-coated paper, and synthetic resin pulp such as polyethylene and natural pulp. Mixed paper, Yankee paper, baryta paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, cellulose fiber paper, polyolefin coated paper (especially polyethylene) Paper coated with both sides), various plastic films or sheets such as polyethylene terephthalate, polystyrene methacrylate, polyethylene naphthalate, etc., and a treatment that gives white reflection to the plastic film or sheet (for example, titanium oxide into the film) Etc.) Film or sheet, fabrics, metals, glasses and the like, polyolefin-coated paper (paper, particularly coated on both sides with polyethylene), cast-coated paper is preferred.

As thickness of a support body, it is 25-300 micrometers normally, 50-260 micrometers is preferable and 75-220 micrometers is more preferable. The stiffness and smoothness of the support are not particularly limited and may be appropriately selected depending on the intended purpose. However, for a photographic image receiving paper, a support close to a color silver salt photograph is preferable. The density of the support is preferably 0.7 g / cm ³ or more from the viewpoint of fixing performance.

  The thermal conductivity of the support is not particularly limited and may be appropriately selected depending on the intended purpose. From the viewpoint of fixing performance, it is 2.1 kW / under 20 ° C. and 65% relative humidity. It is preferably m · h · ° C. or higher. The thermal conductivity can be measured by a method described in JP-A-53-66279 using a transfer paper conditioned according to JIS P8111.

  Various additives appropriately selected according to the purpose can be added to the support according to the present invention within a range that does not impair the effects of the present invention. Examples of the additive include whitening agents, conductive agents, fillers, pigments such as titanium oxide, ultramarine blue, and carbon black, and dyes.

  In addition, one or both surfaces of the support according to the present invention can be subjected to various surface treatments and undercoating treatments for the purpose of improving the adhesion with a layer provided thereon. Examples of the surface treatment include activity of glossy surface or fine surface, mat surface, or silk surface described in JP-A-55-26507, corona discharge treatment, flame treatment, glow discharge treatment, plasma treatment, etc. And the like. Examples of the undercoating treatment include the method described in JP-A No. 61-84443. These treatments may be performed alone, or may be subjected to an activation treatment after performing the above-described molding treatment or the like, and may further be subjected to a primer treatment after a surface treatment such as an activation treatment, Each of these means can be arbitrarily combined.

  A hydrophilic binder, a semiconductive metal oxide such as alumina sol or tin oxide, and carbon black or other antistatic agent may be applied to the support, the front surface or the back surface of the support, or a combination thereof. . Specific examples of such a support include those described in JP-A No. 63-220246.

《Other constituent layers》
In the electrophotographic image receiving material of the present invention, in addition to the toner receiving layer and the heat insulating layer described above, other constituent layers can be provided. The other constituent layers are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a surface protective layer, an intermediate layer, an undercoat layer, a cushion layer, a charge control (prevention) layer, a reflective layer, and a color. Examples include a taste preparation layer, a storage stability improving layer, an adhesion preventing layer, an anti-curl layer, and a smoothing layer. These may have a single layer structure or a laminated structure. When the support is a reflective support and is a reflective electrophotographic image receiving material in which the toner receiving layer according to the present invention is provided on the support, each layer provided on the support needs to be transparent. Rather, it is preferably white.

  As the opacity of the electrophotographic image-receiving material of the present invention, the value measured by the method defined in JIS P 8138 is preferably 85% or more, more preferably 90% or more.

  In the electrophotographic image-receiving material of the present invention, for the purpose of imparting backside output suitability, improving backside output image quality, improving curl balance, imparting writing properties, inkjet, other print suitability, improving device passability, etc. A back layer can be provided on the side opposite to the side on which the image receiving layer is provided. The back layer may have the same configuration as the image receiving layer side in order to improve the double-sided output suitability. In the back layer, the above-mentioned various additives can be used, and it is particularly preferable to use the above-mentioned matting agent, slip agent, charge adjusting agent and the like. The back layer may be a single layer or two or more layers. In addition, when releasing oil is used for a fixing roller or the like to prevent offset at the time of fixing, it is preferable that the back surface has oil absorbability.

  In the electrophotographic image-receiving material of the present invention, an adhesion improving layer can be provided for the purpose of improving the adhesion between the support, the heat insulating layer, the toner receiving layer, and other constituent layers.

  In the electrophotographic image-receiving material of the present invention, various additives can be used for the purpose of improving the stability of the output image and improving the stability of the image-receiving layer itself. Examples of such additives include various known antioxidants, anti-aging agents, ultraviolet absorbers, light stabilizers, deterioration inhibitors, ozone deterioration inhibitors, antiseptics, and antifungal agents.

  The electrophotographic image-receiving material of the present invention can be used for image formation with an electrophotographic toner by an electrophotographic method, and can be suitably used for color image formation with an electrophotographic color toner.

<Electrophotographic toner>
The toner used for image formation using the electrophotographic image-receiving material of the present invention is not particularly limited as long as it is a known electrophotographic toner, and the toner production method is known production such as a pulverization method or a polymerization method. Although it is not particularly limited as long as it is a method, in order to exert the effect of the present invention, the monomer is emulsion-polymerized in a suspension polymerization method or a liquid to which an emulsion of necessary additives is added, and a fine polymer is obtained. The production method is preferably such that the particles are produced, and then an organic solvent, an aggregating agent and the like are added and associated. At the time of association, a method of preparing by mixing with a dispersion liquid of a release agent or a colorant necessary for the constitution of the toner and making it associate, or a toner constituent component such as a release agent or a colorant in the monomer A method of emulsion polymerization after dispersion is preferred. Here, the association means that a plurality of resin particles and colorant particles are fused.

  Although it does not specifically limit as a manufacturing method of suspension polymerization method, The following manufacturing methods can be mentioned.

  That is, various constituent materials such as a colorant and, if necessary, a release agent, a charge control agent, and a polymerization initiator are added to the polymerizable monomer, and a homogenizer, a sand mill, a sand grinder, an ultrasonic disperser, etc. Various constituent materials are dissolved or dispersed in the polymerizable monomer. The polymerizable monomer in which these various constituent materials are dissolved or dispersed is diffused in an aqueous medium in the presence of a dispersion stabilizer, and the toner is formed into oil droplets of a desired size as a toner using a homomixer or a homogenizer. Disperse to Thereafter, the stirring mechanism is transferred to the reaction apparatus which is the aforementioned stirring blade, and the polymerization reaction is advanced by heating. After completion of the reaction, the dispersion stabilizer is removed, filtered, washed, and dried to prepare a toner.

  Further, as a method for producing a toner, a method in which resin particles are prepared by fusing in an aqueous medium can also be mentioned. The method is not particularly limited, and examples thereof include methods described in JP-A-5-265252, JP-A-6-329947 and JP-A-9-15904. That is, a method of associating a plurality of fine particles composed of resin particles and colorants, etc., or particles composed of resin and colorant, particularly after dispersing them in water using an emulsifier, The toner is formed by adding the above flocculant and salting out, and at the same time, heat-fusing at or above the glass transition temperature of the formed polymer itself, and heat-drying the particles in a fluid state while containing water. be able to. Here, an organic solvent that is infinitely soluble in water may be added simultaneously with the flocculant.

  As the resin component of the toner, a known resin can be used, but generally, a polyester resin, a styrene-acrylic resin, or the like can be mainly used. When an image is formed on the coating layer, it is preferable to select a resin having high compatibility with a resin component such as an adhesive contained in the coating layer as the resin component of the toner. From this point of view, as the resin component of the toner, one or a mixture of two or more of polyester resin, styrene-acrylic ester resin, styrene-methacrylic ester resin, etc. may be used depending on the purpose. Is preferred.

  The volume average particle diameter of the toner is preferably in the range of 2 to 10 μm, and more preferably in the range of 3 to 9 μm. When the volume average particle diameter of the toner is less than 2 μm, the chargeability tends to be insufficient and the developability may be lowered. On the other hand, when the toner exceeds 10 μm, the resolution of the image may be lowered. Therefore, it is not preferable respectively.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

Example 1
<< Preparation of Reflective Support A >>
A white base paper 1 having a basis weight of 160 g / m ^{2 made} of 50% sulfate method bleached hardwood pulp (LBKP) and 50% sulfate method bleached softwood pulp (NBSP) was prepared.

Polyethylene was melt-extruded and laminated at 300 ° C. as a back resin layer on the back surface of the white base paper 1 to coat the back laminate layer 1 with 30 g / m ² .

Next, as a surface resin layer on the surface side, 91% polyethylene and 9% rutile type titanium oxide were kneaded and then coated with 25 g / m ² of water-resistant resin layer 1 by melt extrusion lamination at 300 ° C. A reflective support A having a coating layer was prepared.

<< Preparation of electrophotographic image receiving material 101 >>
On the surface side of the prepared reflective support A, the following heat insulating layer X coating solution is applied and dried using a slide hopper so that the dry film thickness is 50 μm and the toner receiving layer α coating solution is 10 μm in dry film thickness. Then, after the heat insulation layer X and the toner receiving layer α were formed, heat treatment was performed for 3 days under conditions of 36 ° C. and humidity, whereby the electrophotographic image receiving material 101 was produced.

(Insulation layer X coating solution)
Hollow particle dispersion (HP1055, manufactured by Rohm & Haas Co., Ltd., spherical diameter = 1.0 μm)
50% by mass
Gelatin 3% by mass
Dichloro-S-triazine aqueous solution (4%) 2% by mass
Dioctyl sodium sulfosuccinate aqueous solution (solid content 1%) 5% by mass
40% by weight of water
The porosity of the heat insulating layer X was 65%.

(Toner-receiving layer α coating solution)
Acrylic resin water dispersion (Muvinyl 745, Nichigo Movinyl, Tg = 21 ° C)
40% by mass
Dioctyl sodium sulfosuccinate aqueous solution (solid content 1%) 20% by mass
Gelatin 3% by mass
Dichloro-S-triazine aqueous solution (4%) 2% by mass
35% by weight of water
<< Preparation of Electrophotographic Image Receiving Material 102 >>
In the production of the electrophotographic image receiving material 101, an electrophotographic image receiving material 102 was produced in the same manner except that the following heat insulating layer Y coating solution was used instead of the heat insulating layer X coating solution.

(Insulation layer Y coating solution)
Hollow particle dispersion (HP1055, manufactured by Rohm & Haas Co., Ltd., spherical diameter = 1.0 μm)
50% by mass
Ethylene vinyl acetate copolymer latex (M082, manufactured by Nichigomo Vinyl Co., Ltd., average particle size 0.8 μm, softening point 100 ° C.) 10% by mass
Gelatin 3% by mass
Dichloro-S-triazine aqueous solution (4%) 2% by mass
Dioctyl sodium sulfosuccinate aqueous solution (solid content 1%) 5% by mass
30% by weight of water
In addition, the porosity of the heat insulation layer Y was 61%.

<Evaluation of electrophotographic image receiving materials>
As an image forming apparatus, a laser printer “Magicor 2430” (manufactured by Konica Minolta Business Technology Co., Ltd.) is used, and fixing conditions are appropriately adjusted. Images were output and evaluated as follows.

[Glossiness]
Using the image forming apparatus, a black solid image was output so that the amount of one-component toner was 10 g / m ² , and an unfixed toner image was produced. Further, an unfixed toner image was formed on the surface side of each electrophotographic image-receiving material at 200 ° C. and a linear velocity of 73 mm / second as fixing conditions.

  Subsequently, the 60 degree glossiness of the image on each sample was measured using a precision glossiness meter (manufactured by Murakami Color Research Laboratory). Moreover, 60 degree glossiness was measured also about the white background part. The glossiness was evaluated from the 60 ° glossiness according to the following criteria.

◎: 65 or more ○: 55 or more, less than 65 △: 45 or more, less than 55 ×: less than 45 [Relief resistance]
Using the image forming apparatus, a black solid image was output so that the amount of one-component toner was 10 g / m ² , and an unfixed toner image was produced. Further, an unfixed toner image was formed on the surface side of each electrophotographic image-receiving material at 200 ° C. and a linear velocity of 73 mm / second as fixing conditions.

  Next, with respect to the image level difference (relief resistance) of the created photographic image, the relief level difference that occurs at the boundary between the part having the toner image and the part without the toner image is measured, and the relief level resistance is determined from the relief level according to the following criteria. Evaluation was performed.

◎: Less than 2.0 μm ○: 2.0 μm or more, less than 3.0 Δ: 3.0 μm or more, less than 5.0 μm ×: 5.0 μm or more The relief step is preferably less than 3.0 μm, more preferably less than 2.0 μm. preferable.

  This relief level difference was measured using a stylus-type roughness meter (KLA, alpha step manufactured by Tencor).

[Break resistance]
Each electrophotographic image-receiving material was cut into a 5 mm × 10 cm strip, and this was wound around a paper tube with a core inner diameter of 3 cm in an environment of 23 ° C. and 55% RH, with the porous layer facing outward. After the removal, the image forming surface side was observed with a magnifying glass, the number of cracks caused by breakage was measured, and the resistance to breakage was evaluated according to the following criteria.

A: No occurrence of fold cracks is observed. O: The number of fold cracks is 1-9. △: The number of fold cracks is 10-29. , 30 to 99. XX: The number of occurrences of cracks is 100 or more. Table 1 shows the evaluation results.

  As is apparent from Table 1, it can be seen that the electrophotographic image-receiving material having the structure defined in the present invention has higher gloss, improved relief resistance and resistance to cracking than the comparative example.

Example 2
<< Preparation of electrophotographic image receiving material 201 >>
The following heat insulating layer Z coating solution was applied to the surface side of the reflective support A produced in Example 1 using a slide hopper so that the dry film thickness was 50 μm and the toner receiving layer γ coating solution was 10 μm dry film thickness. After drying, the heat insulating layer Z and the toner receiving layer γ were formed, and after coating and drying, heat treatment was performed for 3 days under conditions of 36 ° C. and humidity, whereby an electrophotographic image receiving material 201 was produced.

(Insulation layer Z coating solution)
Hollow particle dispersion (MH8101, manufactured by Nippon Zeon Co., Ltd., spherical diameter = 1.0 μm)
50% by mass
Gelatin 3% by mass
Dichloro-S-triazine aqueous solution (4%) 2% by mass
Dioctyl sodium sulfosuccinate aqueous solution (solid content 1%) 5% by mass
40% by weight of water
The porosity of the heat insulating layer Z was 65%.

(Toner-receiving layer γ coating solution)
Acrylic resin water dispersion (Muvinyl 743, Nichigo Movinyl, Tg = 39 ° C)
40% by mass
Dioctyl sodium sulfosuccinate aqueous solution (solid content 1%) 20% by mass
Gelatin 3% by mass
Dichloro-S-triazine aqueous solution (4%) 2% by mass
35% by weight of water
<< Preparation of electrophotographic image receiving materials 202 to 212 >>
In the production of the electrophotographic image receiving material 201, the thermoplastic resin shown in Table 2 was used instead of the hollow particle dispersion of the heat insulating layer Z coating solution, and the ratio of the hollow particle dispersion and each thermoplastic resin was changed to provide heat insulation. Electrophotographic image receiving materials 202 to 112 were produced in the same manner except that the layers were coated.

<Evaluation of electrophotographic image receiving materials>
In the same manner as in Example 1, the glossiness, the relief level difference, and the fracture resistance were evaluated. The results are shown in Table 3.

  As is apparent from Table 3, it can be seen that the electrophotographic image-receiving material having the structure defined in the present invention has higher gloss, improved relief resistance and resistance to cracking than the comparative example.

Claims (5)

In an electrophotographic image-receiving material having a toner receiving layer on a support, at least one hollow particle, an average particle size of 0.1 μm or more and a softening point of 40 to 140 are provided between the support and the toner receiving layer. An electrophotographic image receiving material comprising a heat insulating layer made of thermoplastic resin particles at a temperature of ° C. 2. The electrophotographic image receiving material according to claim 1, wherein the toner receiving layer contains a thermoplastic resin. The electrophotographic image-receiving material according to claim 1, wherein the heat insulating layer has a porosity of 30% or more, and the hollow particles have an outer diameter of 0.3 to 3.0 μm. The electrophotographic image-receiving material according to any one of claims 1 to 3, wherein an average outer diameter ratio of the thermoplastic resin particles and the hollow particles of the heat insulating layer is 0.7 to 1.3. The electrophotographic image-receiving material according to any one of claims 1 to 4, wherein a mass ratio of the thermoplastic resin and the hollow particles in the heat insulating layer is 10:90 to 50:50.