JP2007225681A - Electrophotographic transfer sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic transfer sheet having high image quality, and high image preservability even when the humidity change after printing is caused. <P>SOLUTION: The electrophotographic transfer sheet has a sheet type support being a laminate formed by sticking/laminating a thermoplastic film layer (A) on at least one surface of a core material layer (B) composed of paper base material or thermoplastic polyester resin film, and a toner receiving layer (C) on at least one surface of the sheet type support. At least one intermediate layer (D) containing olefin-(meth)acrylic resin is provided between the toner receiving layer and the sheet type support. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic transfer sheet, and more particularly to an electrophotographic transfer sheet having high image quality and high image storage stability.

  Conventionally, heat roll fixing type electrophotographic printers use a plain paper type PPC paper and an OHP sheet surface-treated with a polyester film. However, PPC paper is limited to use in applications where water resistance, chemical resistance and strength are not required, and OHP sheets are water resistance and chemical resistance, but are transparent and limited to use in OHP applications. Yes. On the other hand, for applications that require water resistance, chemical resistance and strength in printing methods such as offset printing and screen printing, synthetic paper based on polypropylene has been used in the past, and high humidity, chemical exposure, outdoors, etc. It is used for applications such as documents, drawings, photographs, maps, manuals, labels, tags, etc. that are used by bringing or pasting them in the environment. In Japanese Patent Application Laid-Open No. 2002-258509 (Patent Document 1), there is a risk that when the above synthetic paper is printed with a heat roll fixing type electrophotographic printer, there is a risk of paper passing failure or paper breakage. A laminated body in which a thermoplastic resin film is bonded and laminated has been proposed.

  It has also been proposed to provide a toner receiving layer made of a resin layer for the purpose of improving the quality of a printed image. In JP-A-8-194394 (Patent Document 2) and JP-A-8-21645 (Patent Document 3), as a method for forming a receiving layer, there are many types of resins that can be used. In addition, it is preferably used because the thickness and surface properties of the forming layer are easy to control. The paint is prepared by dissolving the resin in an organic solvent such as toluene to prepare an organic solvent-containing paint. However, a method of coating an organic solvent-containing coating is preferable because a coating surface having excellent surface properties and high gloss can be obtained.

  In Japanese Patent Application Laid-Open No. 2004-138705 (Patent Document 4), by providing an undercoat layer or an intermediate layer having a breaking elongation of 20% or more as a high image durability, the surface does not crack even when bent, and a high image A laminate structure that improves surface durability has been proposed.

  However, when such an undercoat layer is provided, the print image, particularly the undercoat layer or the intermediate layer, may be changed when the environment of the print image changes, from a low humidity environment to a high humidity environment, and vice versa. The present situation is that the image surface is cracked and cracked on the image surface, and sufficient image storage stability is not obtained.

JP 2002-258509 A JP-A-8-194394 Japanese Patent Laid-Open No. 8-21645 JP 2004-138705 A

  An object of the present invention is to provide an electrophotographic transfer sheet that can solve the problems in view of the above circumstances and has high image quality and high image storability even when humidity changes after printing occur. It is to be.

The present invention includes the following aspects.
The transfer sheet for electrophotography according to the present invention is a laminate in which a thermoplastic film layer (A) is bonded and laminated on at least one surface of a core material layer (B) made of a paper base material or a thermoplastic polyester resin film. An intermediate layer (D) having a sheet-like support and a toner receiving layer (C) on at least one surface thereof, and containing an olefin / (meth) acrylic resin between the toner receiving layer and the sheet-like support. At least one layer is provided.
The thermoplastic film (A) is preferably a synthetic paper made of a stretched film mainly composed of a polyolefin resin and an inorganic pigment, and the toner receiving layer is formed on the intermediate layer with an organic solvent for the toner receiving layer. It is preferably formed by coating with a contained paint. Furthermore, it is preferable that the coating amount of the intermediate layer is 5 to 30 g / m ² .

  The present invention provides an electrophotographic transfer sheet having high image quality and high image storage stability, and is extremely useful in practice.

The present invention is described in detail below.
Examples of the material used in the thermoplastic film layer (A) in the present invention include ethylene resins such as high density polyethylene, medium density polyethylene, and low density polyethylene, propylene resins, polymethyl-1-pentene, and ethylene-cyclic olefin. Polyolefin resins such as polymers, polyamide resins such as nylon-6 and nylon-6, 6, polyethylene terephthalate and copolymers thereof, polybutylene terephthalate and copolymers thereof, and thermoplastic polyesters such as aliphatic polyesters Resins, polycarbonate, atactic polystyrene, syndiotactic polystyrene and the like can be mentioned. Among these, it is preferable to use a polyolefin resin.

  An inorganic fine powder, an organic filler, a stabilizer, a light stabilizer, a dispersant, a lubricant and the like can be added to the thermoplastic film as necessary. When adding an inorganic fine powder, a thing with a particle size of 0.01-5 micrometers is used preferably. Specifically, heavy calcium carbonate, light calcium carbonate, calcined clay, silica, talc, titanium oxide, barium sulfate, alumina, and the like can be used. When an organic filler is added, it is preferable to select a different type of resin from the thermoplastic film that is the main component. For example, when the thermoplastic film is a polyolefin resin, the organic filler is a polymer such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, nylon-6, nylon-6,6, cyclic olefin, polystyrene, polymethacrylate, and the like. A polymer having a melting point or glass transition temperature higher than the melting point of the resin can be used. When adding an inorganic fine powder and / or an organic filler, it is preferably added within a range of 3 to 50% by mass.

  When a stabilizer is added, it is usually added within a range of 0.001 to 1% by mass. Specifically, sterically hindered phenol-based, phosphorus-based, and amine-based stabilizers can be used. When adding a light stabilizer, it is usually added within a range of 0.001 to 1% by mass. Specifically, sterically hindered amine-based, benzotriazole-based, benzophenone-based light stabilizers, and the like can be used. A dispersant or a lubricant is used for the purpose of dispersing inorganic fine powder, for example. The addition amount is usually in the range of 0.01 to 4% by mass. Specifically, silane coupling agents, higher fatty acid metal soaps such as oleic acid and stearic acid, polyacrylic acid, polymethacrylic acid, and salts thereof can be used.

  The molding method of the thermoplastic film is not particularly limited, and can be suitably selected from known methods. For example, using a single-layer or multi-layer T die or I die connected to a screw-type extruder, and molding using a cast molding, calender molding, rolling molding, inflation molding method or the like that extrudes molten resin into a sheet. Can do.

  The thermoplastic film is preferably uniaxially or biaxially stretched. Stretching can be performed by any of various methods that are usually used. In the case of a non-crystalline resin, the stretching temperature is higher than the glass transition temperature of the thermoplastic film resin to be used, and in the case of a crystalline resin, a thermoplastic film having a temperature not lower than the glass transition temperature of the non-crystalline portion and not higher than the melting point of the crystal portion. It can carry out in the temperature range suitable for resin for an application. Specifically, a temperature 2 to 50 ° C. lower than the melting point of the thermoplastic film resin is preferable. As the stretching method, longitudinal stretching using the peripheral speed difference of the roll group, lateral stretching using a tenter oven, simultaneous biaxial stretching using a combination of a tenter oven and a linear motor, and the like can be used.

  The draw ratio is appropriately determined in consideration of the characteristics of the thermoplastic film resin used. For example, when a propylene homopolymer or a copolymer thereof is used as a resin for a thermoplastic film, it is preferably 2 to 10 times when stretched in one direction, and 10 to 50 times in area magnification in the case of biaxial stretching. It is preferable.

  If a thermoplastic film resin containing an inorganic fine powder or an organic filler is stretched, a stretched porous resin film having fine pores inside can be obtained. The stretched thermoplastic film layer may be a single layer or may have a multilayer structure.

  The thickness of the thermoplastic film layer (A) is usually 15 μm or more, preferably 25 μm or more. If the thickness of the thermoplastic film layer is less than 15 μm, the resulting electrophotographic transfer sheet is thin, the mechanical strength is insufficient, and curling due to heat may not be sufficiently prevented. The upper limit of the thickness of the thermoplastic film layer is not particularly limited, but if the thickness exceeds 200 μm, the thickness of the obtained electrophotographic transfer sheet becomes excessive and the number of sheets supplied to the paper supply unit of the printer is reduced. And it is also economically disadvantageous. Therefore, in general, the thickness of the thermoplastic film layer is preferably 200 μm or less, more preferably 150 μm or less.

  For the core material layer (B) used in the present invention, paper base materials such as fine paper, coated paper, art paper, cast coated paper mainly composed of cellulose pulp are preferably used. Also, thermoplastic polyester resin films such as polyethylene terephthalate and its copolymers, polybutylene terephthalate and its copolymers, and aliphatic polyester are heat resistant, and have a smooth surface and small irregularities. Since it is favorable, it is preferably used.

  The thickness of the core material layer (B) used in the present invention is not particularly limited, but is generally 50 to 200 μm. If the thickness is less than 50 μm, the electrophotographic transfer sheet obtained may have insufficient mechanical strength, and the repulsive force against deformation will be insufficient, and electrophotographic transfer that occurs during printing or printing. Sheet curling may not be sufficiently prevented. On the other hand, if the thickness exceeds 200 μm, the thickness of the obtained electrophotographic transfer sheet becomes excessive, and the number of sheets supplied to the paper supply section of the printer is reduced. The texture of the sheet may be inferior.

  In the present invention, the thermoplastic film layer (A) can be bonded to one side or both sides of the core material layer (B). When the thermoplastic film is bonded only to one side of the core material layer, an anti-curl treatment may be carried out by providing a coating layer made of a synthetic resin layer, a pigment, an adhesive, etc. on the opposite side of the adhesive surface of the core material layer. preferable. The coating layer can be further provided with printability, paper supply / dischargeability, and antiblocking properties, and various recordings such as water resistance, oil resistance, slip resistance, thermal recording, thermal transfer recording, and inkjet recording. Of course, it is also possible to impart aptitude and the like.

  When the thermoplastic film layer (A) is bonded to both sides of the core material layer (B), the laminated thermoplastic film may be the same film on both sides, or the type of the front and back films may be different. When a polypropylene resin film is laminated on one surface of the core layer, it is preferable to laminate a polypropylene resin film on the other surface in terms of blank paper curl and post-printing curl.

The method for adhering and laminating the thermoplastic film layer (A) on at least one side of the core material layer (B) is not particularly limited, but includes a wet laminating method, an extrusion laminating method, a dry laminating method, and a wax. A known technique such as a laminating method is used. In general, the dry laminating method is widely used. As an adhesive used at this time, a polyisocyanate-based or epoxy-based curing agent is added to a polyether-based or polyester-based polymer adhesive component. A blended product is often used. The coating amount of the adhesive is in the range of 1 to 30 g / ^{m 2} is desirable. When adhering and laminating the thermoplastic film layer (A) on both sides of the core material layer (B), in order to maintain the curl balance, the coating amount of the adhesive on the front side film layer and the back side film layer is made the same. Is preferred. An extrusion laminating method is also preferably used for improving the image quality.

  In the present invention, a white pigment-containing polyolefin resin composition is extracted as a thermoplastic film layer on the surface of a paper substrate by an extrusion laminate, and further a polyolefin resin composition is extracted as a thermoplastic film layer on the back side of the paper substrate. So-called resin-coated paper provided with a back surface resin coating layer by means of a laminate laminate can be suitably used as a sheet-like support.

  The intermediate layer (D) used in the present invention contains an olefin / (meth) acrylic resin. The reason why the olefin / (meth) acrylic resin is suitable is considered to be that the olefin skeleton is hydrophobic, so that the water absorption / dehydration due to humidity change is small, and the expansion and contraction of the intermediate layer is suppressed. As the olefin / (meth) acrylic resin, the olefin component is selected from at least one of olefins such as ethylene, propylene, butylene, pentene, hexene, and the (meth) acrylic component is an acrylic acid alkyl ester. It is selected from at least one of monomers and / or alkyl methacrylate monomers and is obtained by polymerizing these olefin components and (meth) acrylic components.

  The acrylic acid alkyl ester monomer has an alkyl group having 1 to 10 carbon atoms, and examples thereof include, but are not limited to, methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, and ethylhexyl acrylate. is not.

  The methacrylic acid alkyl ester monomer has an alkyl group having 1 to 10 carbon atoms, and examples thereof include, but are not limited to, methyl methacrylate, ethyl methacrylate, butyl methacrylate, propyl methacrylate, and ethylhexyl methacrylate. is not.

  The content of the olefin / (meth) acrylic resin in the intermediate layer is preferably 5 to 100% by mass, and if it is less than 5% by mass, the effect of image storability due to humidity change cannot be obtained.

  In the intermediate layer, other binders, pigments, auxiliaries and the like can be used in combination as long as the effect is not impaired. Examples of the binder used in combination include starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, gum arabic, diisobutylene / maleic anhydride copolymer salt, styrene / maleic anhydride copolymer salt, styrene / acrylic. Vinyl such as acid copolymer salt, urea resin, melamine resin, amide resin, acrylic resin latex, polyurethane latex, styrene, acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, acrylamide, methacrylamide, methyl vinyl ether Polymers and copolymers, synthetic rubber latex such as styrene-butadiene and methyl methacrylate-butadiene resins, polyurethane resin, polyester resin, polyamide resin, olefin Maleic anhydride resin, melamine resin and the like. In the present invention, one or two or more of the pigments can be used in appropriate combination.

  Examples of the pigment include heavy calcium carbonate, light calcium carbonate, kaolin, calcined kaolin, structural kaolin, delaminated kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, alumina, magnesium carbonate, magnesium oxide, Pigments made of mineral materials such as silica, magnesium aluminosilicate, particulate calcium silicate, particulate magnesium carbonate, particulate light calcium carbonate, white carbon, bentonite, zeolite, sericite, smectite, polystyrene resin, styrene-acrylic copolymer Examples thereof include resins, urea resins, melamine resins, acrylic resins, vinylidene chloride resins, benzoguanamine resins, and pigments made of these solid, fine hollow particle, and through-hole organic materials. In the present invention, one or two or more of the pigments can be used in appropriate combination.

  Various auxiliary agents such as surfactants, pH modifiers, viscosity modifiers, softeners, gloss imparting agents, waxes, dispersants, flow modifiers, stabilizers, antistatic agents, cross-linking agents, sizing agents, fluorescent agents At least one of a whitening agent, a colorant, an ultraviolet absorber, an antifoaming agent, a water-proofing agent, a plasticizer, a lubricant, a preservative, and a fragrance may be appropriately included as necessary.

In electrophotographic transfer sheet of the present invention, the solid coating amount of the intermediate layer (D) is preferably from 5 to 30 g / m ^2, can not be obtained storability due to satisfactory humidity change is less than 5 g / m ² In some cases, if it exceeds 30 g / m ² , the operability such as poor drying at the time of coating deteriorates, and the production cost may increase.

  The intermediate layer can have a multilayer structure of one or more layers. When the intermediate layer has a multilayer structure, the composition of the coating solution applied for each layer and the coating amount may be the same or different. As other layers, for example, a laminated structure having a protective layer, a barrier layer, a cushion layer, an antistatic layer, a reflective layer, a color adjusting layer and the like may be used.

  The sheet-like support provided with the intermediate layer can be subjected to a smoothing treatment in a normal drying step, surface treatment step or the like.

  When a smoothing process is performed on the sheet-like support provided with the intermediate layer, it is performed using a smoothing apparatus such as a normal super calendar, gloss calendar, or soft calendar. The smoothing process may be appropriately performed on-machine or off-machine, and the form of the pressure device, the number of pressure nips, heating, and the like are appropriately adjusted according to a normal smoothing device. Commercially available coated paper or the like in which a coating layer composed of a pigment and an adhesive is previously provided on the surface of the paper substrate used for the sheet-like support can also be used.

  As the toner receiving layer of the present invention, known toner receiving layer materials can be applied. As a material for forming the toner receiving layer, a resin having good transferability of toner transferred from the electrophotographic photosensitive member or the intermediate transfer member and having good toner receiving property is used. Examples of the resin for the toner receiving layer include polyester resins, polystyrene resins, styrene-acrylic resins, polycarbonate resins, vinyl chloride resins, vinylidene chloride resins, polyvinyl acetal resins, cellulose derivative resins such as cellulose acetate butyrate, acrylic resins, and the like. Resin, ionomer resin, etc. can be used. Of these, polyester resins and styrene-acrylic resins are preferably used because of excellent toner transferability. If necessary, one or more kinds of coloring dyes, fluorescent dyes, plasticizers, pigments, mold release agents, conductive agents, ultraviolet absorbers and the like may be added to the toner receiving layer. These additives may be applied by mixing with a component for forming the toner receiving layer, or may be applied on and / or under the toner receiving layer as a coating layer separate from the toner receiving layer.

In electrophotographic transfer sheet of the present invention, the solid coating amount of the toner-receiving layer (C), that is preferably 5 to 30 g / m ^2, can not be obtained satisfactory toner receptive is less than 5 g / m ² In addition, if it exceeds 30 g / m ² , the operability such as poor drying during coating may be deteriorated, and the production cost may be increased.

  Examples of the method for forming the coating layer such as the intermediate layer (D) and the toner receiving layer (C) by a coating method include an air knife coater, a varibar blade coater, a pure blade coater, a rod blade coater, a short dwell coater, Curtain coater, die coater, gravure coater, roll coater, spray coater, dip coater, bar coater, comma coater, offset roll coater, reverse roll coater, lip coater, slide bead coater, Champlex coater, brush coater, two-roll or metering A blade-type size press coater, a bill blade coater, a short dwell coater, a gate roll coater, or the like can be used as appropriate. When drying is necessary, it can be performed by a conventional method. In addition, when curing by radiation is necessary, it can be cured by appropriately using a radiation irradiation apparatus such as an ultraviolet irradiation apparatus or an electron beam irradiation apparatus. In this case, (meth) acrylate monomer or resin, and further ultraviolet polymerization Initiators are used as appropriate.

  The electrophotographic transfer sheet of the present invention has a back layer on the back surface of the electrophotographic transfer sheet for the purpose of preventing electrification, the purpose of correcting curling, the purpose of preventing double feeding in the printer during printing, and the like. Can be provided. Of course, it is also possible to perform a super calendar process when forming the back layer.

By providing the back surface layer, an electrophotographic transfer sheet can be supplied to a printer or a copying machine, run in the printer or the copying machine, and smoothly sent out from the printer or the copying machine. The back layer preferably contains one or more of a lubricant, a release agent, an antistatic agent, an organic and / or inorganic pigment, etc., as necessary. The coating amount as the solid content of the backside layer is preferably in a range of from 0.3 to 10 / ^{m 2,} more preferably from 1 to 5 g / ^{m 2.}

  The moisture content in the electrophotographic transfer sheet of the present invention is in the range of 3.0 to 6.5% at the time of opening, so that the glossiness is lowered even if the printed matter is stored in a low or high humidity environment. Therefore, it is preferable that the content is 4.0 to 6.0%, and it is particularly preferable that the content is adjusted to be in the range of 4.5 to 5.5%.

Furthermore, the electrophotographic transfer sheet according to the present invention may have a configuration in which an adhesive layer, a release layer, and a release sheet substrate are sequentially laminated on the back side of the sheet-like support. In this structure, it can peel between an adhesive layer and a peeling layer, and can also be used as a so-called seal type or label type electrophotographic transfer sheet.
Moreover, various application suitability can be added by performing processing such as magnetism, flame retardancy, heat resistance, water resistance, oil resistance, and slip resistance on the back side of the sheet-like support.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. In the examples, “parts” and “%” all indicate “parts by mass” and “% by mass”.

Example 1
(Adjustment of intermediate layer paint)
Olefin / acrylic resin (trade name: Rikabond ET-C0268, manufactured by Chuo Rika Kogyo Co., Ltd.) with a solid content concentration of 100% by mass, polyethylene wax (trade name: SN Coat 289, manufactured by San Nopco) with a solid content concentration of 2% by mass, An antifoaming agent (trade name: Nopco 1407K, manufactured by San Nopco) was dissolved in water so as to be 0.2% by mass to obtain a coating for an intermediate layer.

(Formation of intermediate layer)
The intermediate layer coating is applied on one side of a synthetic paper (trade name: YUPO FPG80, manufactured by YUPO Corporation) with a bar coater so that the coating amount after drying is 10 g / m ² and dried to obtain an intermediate layer. It was.

(Adjustment of paint for toner receiving layer)
100 parts of a polyester resin (trade name: Byron 200, manufactured by Toyobo Co., Ltd.) and 16 parts of a 3% by weight cyclohexane solution of paraffin wax (HNP-51, manufactured by Nippon Seiwa Co., Ltd.) are dissolved in 200 parts of toluene, mixed and stirred to obtain a toner. A coating for the receiving layer was obtained.

(Formation of toner receiving layer)
The toner-receiving layer coating was applied onto the intermediate layer with a bar coater so that the coating amount after drying was 15 g / m ² and dried to obtain a toner-receiving sheet.

(Formation of transfer sheet for electrophotography)
A toner receiving sheet coated with the above toner receiving layer is laminated on one side of 100 μm thick art paper (trade name: Kinfuji 104.7 g / m ² , manufactured by Oji Paper Co., Ltd.) by the dry lamination method. A synthetic paper (trade name: YUPO FPG80, manufactured by YUPO Corporation) was laminated and bonded by a dry laminating method to prepare an electrophotographic transfer sheet.

Example 2
An electrophotographic transfer sheet was prepared in the same manner as in Example 1 except that an olefin / acrylic resin (trade name: Rikabond ET-C1000, manufactured by Chuo Rika Kogyo Co., Ltd.) was used in the adjustment of the intermediate layer coating material of Example 1. Obtained.

Example 3
An electrophotographic transfer sheet was prepared in the same manner as in Example 1 except that an olefin / methacrylic resin (trade name: Aquatex AC-3100, manufactured by Chuo Rika Kogyo Co., Ltd.) was used in the adjustment of the intermediate layer coating material of Example 1. Got.

Example 4
In the adjustment of the intermediate layer coating material of Example 1, an olefin / acrylic resin (trade name: Rikabond ET-0268, manufactured by Chuo Rika Kogyo Co., Ltd.) was added to a solid content concentration of 70% by mass and a polyester resin (trade name: PE-723, Maru). An electrophotographic transfer sheet was obtained in the same manner as in Example 1 except that 30% by mass of the solid content concentration was used.

Example 5
(Creation of opaque sheet support)
After performing corona discharge treatment on both sides of high-quality paper of 180 g / m ² , using a melt extruder, low-density polyethylene having a density of 0.967 g / cm ³ containing titanium dioxide on one side, and the other side Ekisuto the surface, and high density polyethylene 70% by weight of 0.967 g / cm ^3, a mixture in a ratio of low density polyethylene 30 wt% of the density of 0.923 g / cm ^3, so that the thickness respectively is 30μm The sheet-like support was produced by carrying out a lamination laminate.

(Preparation of transfer sheet for electrophotography)
The intermediate layer prepared in Example 1 and the toner-receiving layer were similarly applied to the surface of the sheet-like support on which the low-density polyethylene layer was formed, and dried to obtain an electrophotographic transfer sheet.

Comparative Example 1
In the formation of the electrophotographic transfer sheet of Example 1, an electrophotographic transfer sheet was obtained in the same manner as in Example 1 except that the intermediate layer was not formed.

Comparative Example 2
An electrophotographic transfer sheet was obtained in the same manner as in Example 1 except that polyester resin (trade name: PE-723, manufactured by Maruyoshi Kasei Co., Ltd.) was used in the adjustment of the intermediate layer coating material of Example 1. .

Comparative Example 3
An electrophotographic transfer sheet was obtained in the same manner as in Example 1 except that SBR latex (trade name: LX407S-12, manufactured by Nippon Zeon Co., Ltd.) was used in the adjustment of the intermediate layer coating material of Example 1.

Comparative Example 4
In the formation of the electrophotographic transfer sheet of Example 5, an electrophotographic transfer sheet was obtained in the same manner as in Example 1 except that the intermediate layer was not formed.

(Evaluation)
The electrophotographic transfer sheets obtained in the above Examples and Comparative Examples were evaluated by the following methods, respectively, and the results obtained are shown in Table 1.

[Evaluation of image quality]
A printing test was performed with a color laser printer IPSiO CX9000 and IPSiO CX2500 manufactured by Ricoh, and the image quality was evaluated. The images are ISO / JIS-SCID JIS X 9201-1995 N3 image and Electrophotographic Society of Japan test chart No. 5-1 Using a 1995 image, an A4 size sheet was printed and evaluated according to the following criteria.
○ Uniform and clear image with high gloss on the surface △ Slightly distorted image, but practical level × Image distorted, practically problematic

[Evaluation of image plane in low humidity environment]
The printed matter obtained in the same manner as the image quality evaluation method is left to stand at 23 ° C. and 50% RH for 1 day, and then left to stand at 23 ° C. and 30% RH for 5 days. Visually evaluated.
◎ The surface quality of the image surface is not different from that of untreated products.
○ Although the surface gloss is slightly inferior to the untreated product, it is at a level that is practically acceptable.
Δ: Fine cracks occur on the image surface, resulting in poor surface properties and practical problems.
× Large cracks occur on the image surface, surface properties are significantly reduced, and there are practical problems.

[Evaluation of image plane in high humidity environment]
The printed matter obtained in the same manner as the image quality evaluation method is left for 1 day under conditions of 23 ° C. and 50% RH, and then left under high humidity environment conditions of 30 ° C. and 80% RH for 5 days. Was visually evaluated.
◎ The surface quality of the image surface is not different from that of untreated products.
○ Although the surface gloss is slightly inferior to the untreated product, it is at a level that is practically acceptable.
Δ: Fine cracks occur on the image surface, resulting in poor surface properties and practical problems.
× Large cracks occur on the image surface, surface properties are significantly reduced, and there are practical problems.

The electrophotographic transfer sheet and the method for producing the same according to the present invention have high image quality and high image storage stability, and are practically valuable.

Claims (4)

  A sheet-like support that is a laminate in which a thermoplastic film layer (A) is bonded and laminated on at least one surface of a core layer (B) made of a paper base material or a thermoplastic polyester resin film, and at least on one surface thereof In the electrophotographic transfer sheet having the toner receiving layer (C), at least one intermediate layer (D) containing an olefin / (meth) acrylic resin is provided between the toner receiving layer and the sheet-like support. An electrophotographic transfer sheet characterized by the above.   2. The transfer sheet for electrophotography according to claim 1, wherein the thermoplastic film is a synthetic paper made of a stretched film containing a polyolefin resin and an inorganic pigment as main components.   3. The electrophotographic transfer sheet according to claim 1, wherein the toner-receiving layer is formed by applying an organic solvent-containing paint for toner-receiving layer on the intermediate layer. The electrophotographic transfer sheet according to claim 1, wherein the coating amount of the intermediate layer is 5 to 30 g / m ² .