JPH10291364A - Recording sheet and method for forming image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high glossiness and to alleviate graininess of an image by connecting a resin film containing white pigment independently formed or formed from a melted state on a transparent support to one surface of the support, and providing a transparent image receiving layer on the other surface. SOLUTION: A resin film 13 containing white pigment independently formed or formed from a melted state on a transparent support 11 is connected to a surface of the support 11 to an opposite side to an image receiving layer 12. For example, melted resin containing the pigment is laminated on the support 11 in a laminar state or the film 13 containing the pigment is adhered. The film 13 containing the pigment is generally formed of the pigment and thermoplastic resin. As the resin, polyester or the like, polyvinyl chloride and polyolefin or the like are preferable. The film 13 containing the pigment preferably contains white pigment or particularly titanium dioxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet for forming a reflection image using a coloring material.
In particular, the present invention relates to a recording sheet for producing a high-gloss image sheet by inkjet recording, electrophotographic recording, thermal transfer recording (printing), or the like.

[0002]

2. Description of the Related Art In recent years, with the rapid development of the information industry, various information processing systems have been developed, and recording methods and apparatuses suitable for each information system have been developed and adopted. Among such recording methods, in ink jet recording in which ink is ejected for recording, and in thermal transfer recording using a fusion type coloring material or a sublimation type coloring material, a device to be used is light and compact, and noise is reduced. And excellent in operability and maintainability. Further, the apparatus used in such a recording method is also colorized and widely used. In the conventional electrophotographic system, colorization has been advanced, and high-resolution, full-color printers and copiers have been developed and commercialized.

Various types of ink jet systems have been developed. However, in terms of physical properties, a method using a coloring material solution (aqueous ink) in which water containing a water-soluble dye or a fine particle pigment is a main component of a solvent, And a method using a colorant organic solvent solution (oil-based ink) containing an oil-soluble dye or a fine particle pigment,
There are three types of methods in which a low-melting solid wax (wax ink) containing a dye is melted by heat. The mainstream is a type using an aqueous ink. In any case, the method is to form an image by ejecting liquid fine droplets onto the ink recording sheet.

[0004] There are roughly two types of thermal transfer systems. The first system is to apply heat from a support to a hot-melt ink coated on a support and melt the ink in a heat-applied pattern. In the second method, a heat-sensitive recording material comprising a resin having a high softening point and a sublimable dye is applied to a heat-sensitive recording material comprising a high-softening point resin and a sublimable dye from the support side in the same manner as the former. This is a method (sublimation heat transfer) in which an image is obtained by sublimation of a sublimation dye in a pattern to which heat is applied and transfer to a recording sheet. The mainstream of the electrophotographic method is a method in which an electrostatic latent image is formed by giving a light pattern to a charged photoconductive layer, transferred to a recording sheet after toner development, and melted and fixed with toner by heat.

The above-described image formation by ink jet recording or the like is performed on ordinary paper, and in the following applications, it is necessary to use a transparent sheet. In many cases, a transparent sheet having a transparent image receiving layer on the surface is used. Using a film, an image is formed as described above to create a recording sheet having an image. For example, an OHP film that is increasingly used in place of a slide in a meeting or the like, a backlight display film that is increasingly used in place of a printed poster or a display board, and a film for a second original drawing are cited. be able to. In addition, a hard copy having an image formed on a recording sheet may have a high-definition image and a higher gloss level than that formed on normal paper. That is, considering silver halide photography, which is ideal for hard copy,
High gloss is an important task to be achieved. Also in this case, in order to obtain a high-gloss image, it is necessary to provide an image receiving layer having high transparency, as in the case of using a transparent film such as the OHP film. This makes it possible to form a high-gloss reflection image.

[0006] The recording sheet having high gloss as described above includes, for example, a sheet described in JP-A-5-51469. JP-A-5-5146
No. 9 describes a recording sheet in which a coating layer (image receiving layer) composed of colloidal silica and a water-soluble polymer in a shape of a colloidal silica linked and / or branched with a water-dispersible polymer on one surface of a substrate is provided. Have been. In Example 4, an image receiving layer composed of an acrylic polymer emulsion, polyvinyl alcohol, and branched beaded colloidal silica was formed on a polyethylene terephthalate film having a layer containing calcium carbonate on both surfaces. The polyethylene terephthalate film is a white film, and the recording sheet also has a relatively high gloss. Examples of such a white film include a polyester film in which barium sulfate fine particles are dispersed (Japanese Patent Publication No. 30930/1985) and calcium carbonate of 8 to 10%.
Polyester film containing 30% by weight (JP-B-7-15)
No. 012), a polyester film containing titanium oxide (Japanese Patent Application Laid-Open No. 149926/1995), and the like.

[0007]

However, according to the study of the present inventor, according to the study of the present inventor, a recording sheet having an image receiving layer formed on the above-mentioned white film (for example, a sheet described in JP-A-5-51469) is provided with an ink jet recording medium. When an image is formed by recording, the obtained reflected image is likely to be a coarse image (beading is observed; this is considered to be caused by the granularity of pixels formed by a plurality of ink dots), and is easy to see. It became clear that there was a problem that the image was not soft. Such a phenomenon,
It was clarified that the image was also observed in an image obtained by electrophotographic recording or an image obtained by thermal transfer recording.

The present invention provides a recording sheet for forming a reflection image, which has a high glossiness and, when an image is formed, has reduced graininess (substantially no beading) and exhibits excellent image quality. The purpose is to do. Further, the present invention provides a recording sheet for forming a reflection image, which can form an image by inkjet recording, has a high glossiness, and, when an image is formed, exhibits excellent image quality with reduced graininess. An object of the present invention is to provide an image forming method by ink jet recording using the recording sheet. Further, the present invention provides a recording sheet for forming a reflection image, which can form an image by electrophotographic recording, has a high glossiness, and exhibits excellent image quality with reduced graininess when an image is formed. And an image forming method by electrophotographic recording using the recording sheet. Also,
The present invention can form an image by thermal transfer recording (printing), has a high glossiness, and, when an image is formed, has a reduced graininess and exhibits excellent image quality and is a recording sheet for forming a reflective image. It is another object of the present invention to provide an image forming method by thermal recording using the recording sheet.

[0009]

According to the present invention, a resin film containing a white pigment formed independently or formed in a molten state on one side of a transparent support is joined to the transparent support. A recording sheet for forming a reflection image, comprising a transparent image receiving layer provided on the other surface of the transparent support.

Preferred embodiments of the recording sheet of the present invention are as follows. 1) The transparent image receiving layer is a layer for inkjet recording comprising a water-soluble resin and a basic polymer, crosslinked polymer fine particles, imidazole group-containing polymer or inorganic fine particles. 2) The transparent image receiving layer is a layer made of polyester for electrophotographic recording. 3) The transparent image receiving layer is a layer for thermal transfer recording comprising a polyolefin resin and hydrophobic fine particles. 4) The glossiness on the image receiving layer side of the recording sheet is 75% or more (particularly 80% or more). 5) The parallel light transmittance on the side of the resin film containing the white pigment of the recording sheet is 2% or less. 6) The parallel light transmittance of the resin film containing the white pigment is 2
% Or less. 7) A resin film containing a white pigment is composed of a white pigment (preferably an inorganic white pigment) and a thermoplastic resin. 8) The resin film containing the white pigment is joined by bonding the resin film on a transparent support with an adhesive. 9) The resin film containing the white pigment is bonded by melting the resin containing the white pigment to form a layer (film) on the transparent support.
It is made by laminating. 10) The bonding of the resin film containing the white pigment is performed by bonding the resin film containing the white pigment to the transparent support under heating via an adhesive. 11) The resin film containing the white pigment is joined by co-extruding the resin for forming the transparent support and the resin containing the white pigment. 12) The ink used for the inkjet recording of the above 1) is an aqueous ink (a coloring material solution or a coloring material dispersion in which water containing a water-soluble dye or a fine particle pigment is a main component of a solvent,
In particular, 50% by weight or more of the solvent is water). 13) The transparent support is made of polyester.

In the present invention, the aqueous ink is imagewise jetted onto the transparent image-receiving layer for ink jet recording of the recording sheet of the above 1) to form an image of the aqueous ink on the surface of the transparent image-receiving layer. There is also an image forming method comprising: Furthermore, the present invention provides the following steps (1) to (4): (1) a step of imagewise exposing the surface of the photoreceptor to form a latent image, and (2) a step of forming the latent image from a coloring material and a binder resin. (3) transferring the image to a transparent image-receiving layer for electrophotographic recording of a recording sheet according to (2), wherein the image is formed by developing using a toner to form an image on the photoreceptor surface;
(4) There is also an image forming method including a step of forming an image on the image receiving layer by pressing a transferred image of the toner with a fixing device (heat roll) heated to a fixing temperature of the toner. Further, the present invention provides a thermal transfer ink sheet (eg, a thermal ink ribbon) having a wax-like ink layer,
The wax-like ink layer is superimposed on the transparent image-receiving layer for thermal transfer recording of the recording sheet of the above 3), heated imagewise (using a thermal head or the like), and the wax melted imagewise by the heat. There is also an image forming method which comprises forming an ink image by transferring a state ink to the surface of the image receiving layer.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The recording sheet of the present invention is used for forming a reflection image, and comprises a support, a transparent image-receiving layer provided on one surface thereof, and a white pigment provided on the other surface. Has a basic configuration in which a resin film containing is formed. FIG. 1 shows a sectional view of the basic structure of the recording sheet of the present invention. It comprises a transparent support 11, a transparent image receiving layer 12 provided on one surface thereof, and a resin film 13 containing a white pigment provided on the other surface. The resin film 13 containing a white pigment is formed by bonding a resin film containing a white pigment formed independently or formed from a molten state on the surface of the transparent support opposite to the image receiving layer. Provided by This bonding is performed, for example, by laminating a molten resin containing a white pigment in a layer on a support or by bonding a resin film containing a white pigment. Thereby, the image obtained by the ink jet recording has a high glossiness, and has a reduced graininess (reduced graininess), and is a very easy-to-view soft image. The images obtained by the electrophotographic recording and the images obtained by the thermal transfer recording are also soft images which have reduced graininess and are very easy to see, like the images obtained by the ink jet recording.

The recording sheet of the present invention can be manufactured, for example, as follows. As a material that can be used as the transparent support, any material can be used as long as it is a transparent material, but a thermoplastic resin is generally used. Examples of the thermoplastic resin include polyesters such as polyethylene terephthalate and polyethylene naphthalate; cellulose esters such as nitrocellulose, cellulose acetate, and cellulose acetate butyrate; and polysulfone, polyphenylene oxide, polyimide, polycarbonate, and polyamide. Can be. Among these, polyesters are preferred, and polyethylene terephthalate is particularly preferred.
The thickness of the transparent support is not particularly limited.
μm is preferred because it is easy to handle.

On the surface of the transparent support (the side on which the image receiving layer is not provided), a resin film containing the white pigment of the present invention is formed. A resin film containing a white pigment generally comprises a white pigment and a thermoplastic resin. Examples of the thermoplastic resin include polyesters such as polyethylene terephthalate and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene; nitrocellulose;
Examples include cellulose esters such as cellulose acetate and cellulose acetate butyrate, and further include polyvinyl chloride, polysulfone, polyphenylene oxide, and polycarbonate. Polyesters, polyvinyl chloride and polyolefins are preferred.

Examples of the above-mentioned white pigment materials include inorganic white pigments such as titanium dioxide (anatase and rutile), zinc oxide, zinc sulfide, lithopone, lead carbonate, lead sulfate (basic) and antimony oxide; Barium, aluminum hydroxide, magnesium carbonate, calcium carbonate,
Inorganic extender such as calcium silicate, aluminum silicate and magnesium silicate (highly transparent white pigment)
And organic white pigments such as fluorocarbon and polytetrafluoroethylene.
The resin film containing a white pigment preferably contains titanium dioxide, barium sulfate, magnesium carbonate or calcium carbonate as the white pigment, and particularly preferably contains titanium dioxide. The average particle size of the white pigment,
The range is preferably from 0.1 to 10 μm, particularly from 0.3 to 3 μm.
The range of m is preferred. The resin film containing the white pigment generally contains the pigment in the range of 10 to 80% by weight,
It is preferable to contain 5 to 70% by weight. The weight ratio of the pigment to the thermoplastic resin is generally 1/9 to 8/2, and 1.5 /
8.5 to 7/3 are preferred. The layer thickness of the resin film containing a white pigment is generally in the range of 5 to 100 μm,
10 to 80 μm is preferred. The parallel light transmittance of the resin film containing the white pigment is 2% or less.

The resin film containing a white pigment is formed by bonding an independently formed resin film containing a white pigment to a support by bonding with an adhesive or the like, or is formed in a molten state on the support. Is formed by bonding a resin containing a white pigment to the surface of the support in the form of a film. Such formation can be usually performed by a known laminating method (eg, extrusion lamination, hot melt lamination, dry lamination, and wet lamination) or coextrusion. The resin film containing a white pigment formed independently is generally produced by forming a mixture of a white pigment and a thermoplastic resin into a film by extrusion or the like. That is, the resin film containing the white pigment is formed by melting a resin containing a white pigment (white resin) and extruding the melt into a film on a support (extrusion lamination). Alternatively, it is performed by pressing (may be heated) a resin film containing a white pigment on a support via an adhesive (dry lamination, wet lamination). Alternatively, the adhesion of the resin film containing the white pigment on the support may be performed by simply using pressure bonding by heating without using an adhesive, or by using heat compression bonding using a solvent. Alternatively, it can be carried out by melting a resin for forming a transparent support and a resin containing a white pigment and co-extruding the resin.

In the extrusion lamination, for example, a white pigment, which is a material of a resin film containing a white pigment, and a thermoplastic resin are melt-mixed in an extruder (eg, a single-screw or twin-screw kneading extruder) and then melt-extruded. On a chilled roll and lamination on a transparent support. In addition, a transparent film for a transparent support is sent on a steel roll, and a resin film containing a white pigment having an adhesive layer on one surface is sent and laminated on a rubber roll provided opposite to the steel roll. By doing so, a laminate in which a resin film containing a white pigment is adhered to a transparent support is obtained. Further, in the co-extrusion method, for example, a thermoplastic resin for forming a support is supplied to an extruder A, and a thermoplastic resin containing a white pigment for forming a resin film containing a white pigment is supplied to an extruder B. The resin extruded by the extruders A and B may be cast in a sheet form from a T-die so as to form a two-layer structure.

An undercoat layer can be provided on the transparent support (generally, the side on which the resin film containing a white pigment is not provided). The undercoat layer is a layer made of a polymer. Examples of the polymer include a styrene / butadiene copolymer, a vinylidene chloride polymer, a vinyl chloride polymer, a vinyl acetate polymer, polyvinyl formal, polyvinyl butyral, a vinylidene fluoride polymer, and a vinylidene fluoride polymer. Coalescing, polyester resin, polyamide resin, acrylic resin and gelatin. Styrene / butadiene-based copolymer, vinylidene chloride-based polymer, vinylidene fluoride-based polymer, vinylidene fluoride-based polymer, polyester resin, polyamide resin, and acrylic resin are preferable, and especially recording sheets for ink jet recording and electrophotography. In this case, a styrene / butadiene copolymer, a vinylidene chloride polymer and a polyester resin are preferred. On the other hand, gelatin is preferred for the thermal transfer recording sheet. The polymer preferably has a hydroxyl group, a carboxyl group, an amino group, and a carbonyldioxy group by introducing a copolymer component. Further, the undercoat layer is preferably formed from a latex of the above polymer. In particular, it is preferably formed from a styrene / butadiene-based latex or a vinylidene chloride-based latex. The undercoat layer preferably contains a cross-linking agent such as a triazine derivative (eg, 2,4-dichloro-6-hydroxy-S-triazine) (which also functions as an adhesion-imparting agent). The thickness of the undercoat layer is generally from 0.01 to 1.0 μm. The surface of the support is preferably subjected to a surface treatment such as a corona discharge treatment, a plasma treatment, a flame treatment, and an ultraviolet irradiation treatment in order to further improve the adhesion between the support and the layer thereon.

A transparent image receiving layer is provided on the surface of the transparent support on the side where the resin film containing the white pigment is not provided. The image receiving layer is a layer made of a resin, and may contain inorganic fine particles and organic fine particles as necessary. As the resin, a water-soluble resin, a resin used as a latex,
Organic solvent-soluble resins can be mentioned. Examples of the water-soluble resin include polyvinyl alcohol (PV) as a resin having a hydroxyl group as a hydrophilic structural unit.
A), ethylene-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified polyvinyl alcohol, cellulose resins (methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HE
C), carboxymethylcellulose (CMC), etc., chitins and starch; as a resin having an ether bond, polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PE)
G) and polyvinyl ether (PVE); and as resins having amide groups or amide bonds, polyacrylamide (PAAM), polyvinylpyrrolidone (PVP)
And vinylpyrrolidone-based copolymers. Further, a polyacrylate having a carboxyl group as a dissociable group, a maleic acid resin, an alginate and gelatins; a polystyrene sulfonate having a sulfone group, an amino group, an imino group, a tertiary amine and a quaternary ammonium salt. Having polyallylamine (PAA), polyethyleneimine (PEI), epoxidized polyamide (EPA
m), polyvinyl pyridine and gelatins. In the case of ink jet recording, polyvinyl alcohol (PVA) is preferable, and its saponification degree is particularly 70.
Those having a content of about 90 mol% are preferred.

Examples of resins soluble in organic solvents include polyester resins, polyamide resins, polyurethane resins, melamine resins, phenolic resins, styrene / butadiene copolymers, vinylidene chloride polymers, vinyl chloride polymers, and vinyl acetate. Polymer, polyvinyl formal, polyvinyl butyral, vinylidene fluoride polymer, vinylidene fluoride polymer, and acrylic resin. Examples of the resin used as the latex include a styrene / butadiene copolymer, a vinylidene chloride polymer, a vinyl chloride polymer, a vinyl acetate polymer, a vinylidene fluoride polymer, and a vinylidene fluoride polymer. , Polyester resin, polyamide resin, polyurethane resin and acrylic resin, and polyolefin resin (eg, ethylene / acrylic acid copolymer, ethylene / sodium acrylate copolymer, ethylene / acrylic ester copolymer, ethylene / vinyl alcohol copolymer) Polymers, ionomer resins and urethane-modified polyolefin resins).

In the transparent image receiving layer, in addition to the above resin,
Contains a matting agent to reduce frictional properties, various surfactants to improve coating suitability and surface quality, various antioxidants, ultraviolet absorbers, and fluorescent whitening agents to suppress deterioration of coloring materials You can go out.

The image-receiving layer for ink-jet recording comprises the above-mentioned water-soluble resin, crosslinked polymer fine particles having an average particle diameter of 200 nm or less, and a basic polymer represented by the following general formula (I) (used as a latex). Alternatively, it is preferable that the polymer comprises an imidazole group-containing polymer.

The above water-soluble resin is preferably crosslinked with a crosslinking agent in order to improve the water resistance of the transparent image receiving layer. That is, a crosslinking agent is added to a coating solution containing fine particles of a polymer crosslinked with a water-soluble resin or a latex of a basic polymer, applied to a support, and dried by heating (crosslinking) to form an image receiving layer. Preferably, it is formed.

Examples of the crosslinking agent include aldehydes (eg, formaldehyde, glyoxal and glutaraldehyde), N-methylol compounds (eg, dimethylolurea and methyloldimethylhydantoin), dioxane derivatives (eg, 2,3-dihydroxydioxane) ), Compounds that act by activating the carboxyl group (eg, carbenium, 2-naphthalenesulfonate, 1,1-bispyrrolidino-1-chloropyridinium and 1-morpholinocarbonyl-3- (sulfonatoaminomethyl)), Active vinyl compounds (eg, 1,3,5-triacroyl-hexahydro-s-triazine, bis (vinylsulfone) methane and N, N′-methylenebis- [β- (vinylsulfonyl) propionamide]),
Active halogen compounds (eg, 2,4-dichloro-6-hydroxy-S-triazine), compounds having an epoxy group (eg, bisphenol A type epoxy resin, glycidyl versatate, phenyl glycidyl ether), isoxazoles, Melamine resins, isocyanate compounds and dialdehyde starch can be mentioned. These can be used alone or in combination. In consideration of productivity, it is preferable to use an aldehyde such as glutaraldehyde having a high reaction activity or a melamine resin. Preferred examples of the water-soluble resin used in combination with the crosslinking agent include polyvinyl alcohol. The amount of the crosslinking agent to be added is preferably 0.1 to 20% by weight, particularly 0.5 to 1% by weight, based on the water-soluble resin.
5% by weight is preferred.

The crosslinked polymer fine particles having an average particle diameter of 200 nm or less are preferably anionic or cationic. Such polymer fine particles generally contain at least one monomer selected from the group consisting of alkyl acrylates, alkyl methacrylates, styrene and styrene derivatives with one or more carbon-carbon double bonds in the molecule ( (Preferably two or more) by using an emulsifier having emulsion polymerization.

Preferred examples of the alkyl acrylate and the alkyl methacrylate include alkyl (meth) acrylates having 1 to 18 carbon atoms in the alkyl, such as methyl (meth) acrylate and (meth) acrylic acid. Ethyl, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
Stearyl acrylate can be mentioned. Examples of styrene and styrene derivatives include styrene, α-methylstyrene and vinyltoluene.

In addition to the above monomers, monomers copolymerizable with the above monomers may be used in an amount of 50% by weight or less based on the total amount of the monomers. For example, anionic vinyl monomers of acrylic acid, methacrylic acid, maleic anhydride, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid; dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and quaternary ammonium Cationic vinyl monomers such as vinyl monomers having salts; and (meth) acrylic acid 2-
Examples include nonionic vinyl monomers such as hydroxyethyl, 2-hydroxypropyl (meth) acrylate and (meth) acryloyloxyphosphate.

In addition to the above monomers, a crosslinkable vinyl monomer may be used in an amount of 5% by weight or less based on the total amount of the monomers. For example, bifunctional monomers such as ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, hexamethylenebis (meth) acrylamide, and divinylbenzene; 1,3,5-triacryloylhexahydro-S-triazine And trifunctional monomers such as triallyl isocyanurate; tetramethylolmethanetetraacrylate and N, N, N ',
Examples include tetrafunctional monomers such as N'-tetraallyl-1,4-diaminobutane.

Examples of the carbon-carbon double bond of the emulsifier having one or more carbon-carbon double bonds in the molecule include (meth) allyl group, 1-propenyl group and 2-methyl-1 -A propenyl group, a vinyl group, an isopropenyl group and a (meth) acryloyl group. Among these, a (meth) acryloyl group is preferred. The emulsifier has a cationic group or an anionic group (hydrophilic group) for exhibiting an emulsifying action together with a hydrophobic group. The cationic group is preferable because the function of retaining the ink is large, and the water resistance of the colorant receiving layer is improved. As the cationic group or anionic group (hydrophilic group), -COO
_{H, -COOM, -OSO 3 M,} -N (R 1) (R 2)
^{(R 3), - OH,} -PO (OM) 2, (- O) 3 P,
_{(-O) 2 P (OH)} -, - OP (OH) 2, -OPO
_{(OM) 2, (- O} ) 2 PO (OM), (- O) 3 PO
And-(0R)-[where M represents Na or K;
R ¹ , R ² and R ³ each independently represent a hydrogen atom, alkyl, aralkyl or hydroxyalkyl, and R represents ethylene or propylene]. Of these, -N (R ¹ ) (R ² ) (R
³ ) [R ¹ , R ² and R ³ are each independently a hydrogen atom,
Represents an alkyl or hydroxyalkyl, and at least one group is an alkyl or a hydroxyalkyl]. The emulsifier plays a role of a usual emulsifier and a role of a polymerizable (crosslinkable) monomer. Therefore, the surface of the obtained crosslinked polymer fine particles has the above-described cationic group or anionic group. I have. Of course, it may be present inside the polymer fine particles.

Examples of the emulsifier include a sulfosuccinate salt of a polyoxyethylene alkyl ether having two or more carbon-carbon double bonds in the molecule, and a polyoxyethylene salt having two or more carbon-carbon double bonds in the molecule. Sulfate ester of ethylene alkyl ether, sulfosuccinate of polyoxyethylene alkyl phenyl ether having two or more carbon-carbon double bonds in the molecule, polyoxyethylene having two or more carbon-carbon double bonds in the molecule Alkyl phenyl ether sulfates, acidic phosphoric acid (meth) acrylate dispersants, oligoester (meth) acrylate phosphates or alkali salts thereof, and oligos of polyalkylene glycol derivatives having hydrophilic alkylene oxide groups Ester poly (meth) ac Mention may be made of the rate. These commercially available products include KAYAMER P
M-2 (Nippon Kayaku Co., Ltd.), New Frontier A-
229E (Daiichi Kogyo Seiyaku Co., Ltd.) and New Frontier N-250Z (Daiichi Kogyo Seiyaku Co., Ltd.).

When an emulsifier having one or more carbon-carbon double bonds in the molecule is used, the emulsifier having one carbon-carbon double bond in the molecule is used in a proportion of not more than 60% by weight of the total emulsifier. May be included. Further, the emulsifier having one or more carbon-carbon double bonds in the molecule,
It may contain a usual anionic emulsifier, cationic emulsifier, or nonionic emulsifier. The amount of the emulsifier having one or more carbon-carbon double bonds in the molecule is as follows:
Usually 1 to 20 with respect to 100 parts by weight of the total monomer.
Parts by weight, preferably 3 to 10 parts by weight.

The above crosslinked polymer fine particles can be obtained by a known emulsion polymerization method using the above materials. For example, the above-mentioned emulsifier and water are charged into a reaction vessel, and the monomer is added thereto to emulsify. Then, a radical polymerization initiator is added, and the polymer is heated under stirring to polymerize the monomer. Can be obtained. The addition of the vinyl monomer may be either collective dropping or divided dropping. The concentration of such a material is preferably such that the solid content concentration in the reaction liquid (dispersion liquid) finally obtained is usually 20 to 50% by weight, preferably 30 to 45% by weight.
It is adjusted to be% by weight. PH during the reaction is 3-9
The reaction temperature is preferably a temperature at which the polymerization initiator is activated, and is usually 40 to 90 ° C, and 50 to 90 ° C.
80 ° C. is preferred. The reaction time is usually 30 minutes to 2 hours.

Examples of the radical polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate; water-soluble radical polymerization initiators such as hydrogen peroxide and water-soluble azo initiators; And a reducing agent such as sodium hydrogen sulfite and sodium thiosulfate. Redox-based polymerization initiators are preferred. The amount of the radical polymerization initiator to be added is preferably 0.05 to 5% by weight based on the total amount of the monomers,
Particularly, 0.1 to 3% by weight is preferable. Further, in order to make the obtained polymer fine particles transparent ultrafine particles, it is preferable to carry out the above polymerization in the presence of a transition metal ion as a polymerization accelerator. In the polymer fine particles crosslinked by the emulsifier thus obtained, the emulsifier is present on the surface, and therefore, an anionic group and a cationic group (hydrophilic group) are present on the surface. Become. Therefore, the water-based ink for ink-jet can be easily adsorbed on the surface thereof, and the anionic group, the cationic group and the like can work effectively. Such a hydrophilic group is also present inside the polymer fine particles depending on the type and amount of the emulsifier used and the reaction method.

The obtained crosslinked polymer fine particles have a solid content of usually 20 to 50% by weight, preferably 30 to 50% by weight.
45% by weight of a dispersion having an average particle size of 200
nm or less (preferably in the range of 1 to 100 nm).
The viscosity of the 40% by weight dispersion of polymer fine particles is usually 100 to 500 cps.

When the image receiving layer is mainly composed of the above-mentioned crosslinked polymer fine particles and a water-soluble resin, the weight ratio of the crosslinked polymer fine particles and the water-soluble resin contained in the image receiving layer is 1: 1 to 1: 1. A range of 1:10 (polymer fine particles: water-soluble resin) is preferable, and further 1: 1 to 1: 1.
A range of 5 is preferred.

The basic polymer preferably used for forming the transparent image receiving layer for inkjet recording is represented by the following general formula (I):

[0037]

Embedded image

[Where A is a tertiary amino group or a quaternary amino group;
Represents a monomer unit having a quaternary ammonium base and an ethylenically unsaturated double bond, B represents a monomer unit having at least two ethylenically unsaturated double bonds, and C represents a monomer unit other than the above monomer units of A and B Represents a monomer unit having an ethylenically unsaturated double bond, wherein x is in the range of 10 to 90 mol%, y is in the range of 0 to 10 mol%, and z is in the range of 0 to 90 mol%. is there. ] And used as a latex.

The monomer unit represented by A in the general formula (I) is generally a monomer unit having a quaternary ammonium base and an ethylenically unsaturated double bond. It is preferably a unit represented by (IV).

[0040]

Embedded image

In the general formula (II), R ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms (eg, methyl, ethyl, n-hexyl). R ¹ is preferably a hydrogen atom.

In the general formula (II), R^Two , R^Three And R
^Four Is independently an alkyl group having 1 to 6 carbon atoms or
Represents an aralkyl group having 7 to 10 carbon atoms,
Is R ^Two , R^Three And R^Four At least two groups are
They may be connected to each other to form a ring. Al
The kill group and the aralkyl group may have a substituent.
Examples of alkyl groups include methyl, ethyl, n-propyl
And n-hexyl, substituted alkyl
Examples of the group include a hydroxyalkyl group (eg, 2-hydrido).
Roxyethyl, 3-hydroxypropyl, 3-chloro-
2-hydroxypropyl), alkoxyalkyl group
(Eg, methoxymethyl, 2-methoxyethyl), cyano
Alkyl group (eg, 2-cyanoethyl), halogenated alkyl
Kill group (eg, 2-chloroethyl), allyl, 2-buteni
And propagyl.

Examples of aralkyl groups include benzyl, phenethyl and diphenylmethyl,
Examples of the substituted aralkyl group include an alkyl aralkyl group (eg, 4-methylbenzyl, 2,5-dimethylbenzyl), an alkoxyaralkyl group (eg, 4-methoxybenzyl), a cyanoaralkyl group (4-cyanobenzyl), and halogen. Aralkyl group (eg, 4-chlorobenzyl)
Can be mentioned. Examples of the ring formed by R ² and R ³ include pyrrolidine, piperidine and morpholine. Examples of the ring formed by R ² , R ³ and R ⁴ include imidazole, 2-methylimidazole, triazole, pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine and quinuclidine. .

R ² , R ³ and R ^{4 each} have 1 carbon atom.
An unsubstituted or hydroxyl-containing alkyl group having ³ to ³ carbon atoms, the above-mentioned aralkyl group, or an alkyl group or an aralkyl group having 1 to 3 carbon atoms in which R ² and R ³ form piperidine and R ⁴ has 1 to 3 carbon atoms. It is preferred to represent. In particular, it is preferred that R ² and R ³ form piperidine and R ⁴ represents an unsubstituted or hydroxyl-containing alkyl group having 1 to 3 carbon atoms.

[0045] At a the general formula (II), X ₁ ^- represents an anion. Examples of anions include halogen ions (eg,
Chlorine ion, bromine ion), alkyl sulfate ion (eg,
Methyl sulfate ion, ethyl sulfate ion), alkyl or aryl sulfonate ion (eg, methane sulfonate ion, benzene sulfonate ion), acetate ion and sulfate ion. Of these, halogen ions (eg, chloride ions), alkyl sulfate ions (eg, ethyl sulfate ion) and acetate ions are preferred.
In the above general formula (II), n represents 0, 1 or 2.

In the above general formula (III), R ¹¹ , R ¹² ,
R ¹³ and R ¹⁴ are respectively R ¹ , R ² , R ³ and R ⁴
Is synonymous with Q is a divalent group having 1 to 20 carbon atoms, and examples thereof include an alkylene group (eg, methylene, ethylene) and an arylene group (eg, -Ph-R- [where Ph is 1,4 -A phenylene group, R represents an alkylene group having 1 to 6 carbon atoms or a single bond],
-OR '-[where R' represents an alkylene group having 1 to 6 carbon atoms (eg, oxyethylene, oxytrimethylene)], -O-Ph-R-, -Ph-OR- [ , Ph are as defined above], -NHR'-, -N
(R ″) R′- wherein R ′ is as defined above,
R "is an alkyl group having 1 to 6 carbon atoms or 7 carbon atoms.
~ 12 aralkyl groups], -NH-Ph-R '
-, -Ph-NH-R'-N (R ")-Ph-R-, wherein R, R 'and R" have the same meanings as described above. X ₂ in the general formula (III) ^- is, X ₁ ^- is synonymous. R ¹¹ is preferably a hydrogen atom or a methyl group.

R ¹² , R ¹³ and R ^{14 each} have 1 to 3 carbon atoms.
It is preferred that R ¹² and R ¹³ represent piperidine and R ⁴ represents an unsubstituted or hydroxyl-containing alkyl group having 1 to 3 carbon atoms or the above-mentioned aralkyl group. Q
Is preferably -OR'- or -NHR'-, wherein R 'represents ethylene or propylene.

In the general formula (IV), R ²⁵ represents an alkyl group having 1 to 12 carbon atoms or an aralkyl group having 7 to 12 carbon atoms. The alkyl group and the aralkyl group may have a substituent. Examples of the alkyl group and the aralkyl group include the same as those described in the above examples of R ² , R ³ and R ⁴ . X ₃ in the general formula (IV) ^- is, X ₁ ^- is synonymous. R ²⁵ has 1 to 4 carbon atoms
Is preferably an unsubstituted or hydroxy-containing alkyl group or an aralkyl group having 7 to 9 carbon atoms. R
²⁶ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms (eg, methyl or ethyl), and is preferably a hydrogen atom or methyl.

The monomer unit represented by B in the general formula (I) is preferably a unit represented by the following general formula (V).

[0050]

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In the above formula (V), R ³⁷ represents a hydrogen atom or a methyl group, and P represents a vinyl group ((CH ₂ = CR ³⁷ )
_{and m} represents an integer of 2 to 4.
Examples of the linking group represented by P include an amide group (eg, sulfonamide), an ester group (eg, sulfonic ester), an alkylene group (eg, methylene, ethylene, trimethylene), an arylene group (eg, phenylene) And an aryleneoxycarbonyl group (eg, phenyleneoxycarbonyl). Examples of the monomer forming the monomer unit of the general formula (V) include divinylbenzene, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, neopentyl glycol dimethacrylate, tetramethylene glycol diacrylate, and trimethylolpropane triacrylate. be able to. Of these, divinylbenzene, ethylene glycol dimethacrylate and propylene glycol dimethacrylate are preferred.

The monomer unit represented by C in the general formula (I) is a monomer unit having an ethylenically unsaturated double bond other than the monomer units of A and B, and is a known ethylenically unsaturated double bond. Is formed from a monomer having one. Examples of monomers capable of forming the above monomer units include ethylene, propylene, 1-butene, isobutene, styrene, α-methylstyrene, vinyltoluene, acrylic acid, methacrylic acid, acrylonitrile, and ethylenically unsaturated fatty acids of fatty acids. Ester with a group having one heavy bond (eg, vinyl acetate, allyl acetate), ester of monocarboxylic acid or dicarboxylic acid having an ethylenically unsaturated double bond (eg, methyl methacrylate, ethyl acrylate, n-butyl methacrylate) , N-hexyl methacrylate, n-octyl acrylate, benzyl acrylate, cyclohexyl methacrylate, 2
-Ethylhexyl methacrylate), and dienes (eg, butadiene, isoprene). Of these, styrene, cyclohexyl methacrylate and methyl methacrylate are preferred. The monomer unit represented by C may be formed from two or more of the above monomers.

In the general formula (I), x is from 30 to
Preferably, y is in the range of 99 mol%, y is in the range of 1-8 mol%, and z is in the range of 10-80 mol%.

Preferred structures of the basic polymer represented by the above general formula (I) are shown below. The numbers at the lower right of each repeating unit of the exemplified polymers indicate the respective content ratios (mol%).

[0055]

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[0056]

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[0057]

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[0058]

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The basic polymer latex can be synthesized by ordinary emulsion polymerization. That is, a monomer for constituting a polymer is emulsion-polymerized in the presence of an anionic or cationic surfactant or a nonionic surfactant, and a radical polymerization initiator (eg, a combination of potassium persulfate and potassium hydrogen sulfite). It can be obtained by: The details of the above synthesis method are described in JP-B-62-11678.
On page 8-9.

The solid content of the latex of the basic polymer represented by the above general formula (I) is usually a dispersion of 10 to 50% by weight, preferably 20 to 45% by weight, and the average particle size is generally The range is more than 0.1 μm and 5 μm or less (preferably 0.3 to 2 μm). The viscosity of a 40% by weight dispersion of polymer fine particles is usually 10%.
５００500 cps. When the transparent image-receiving layer for inkjet recording is mainly composed of the above-mentioned basic polymer latex and a water-soluble resin, the ratio of the basic polymer latex and the water-soluble resin contained in the colorant receiving layer is as follows:
The weight ratio is preferably in the range of 5: 5 to 1: 9 (latex: water-soluble resin), particularly preferably in the range of 4: 6 to 2: 8. The transparent image receiving layer for inkjet recording is generally mainly composed of the above-mentioned basic polymer latex and a water-soluble resin, or is composed of the crosslinked polymer fine particles and a water-soluble resin. And crosslinked polymer fine particles.

The transparent image receiving layer for ink jet recording is a layer formed from a water-soluble resin (particularly polyvinyl alcohol and polyvinyl pyrrolidone) and a polymer or copolymer of the vinyl monomer having an imidazole group. Is also preferred. Imidazole group-containing polymer (that is, at least one kind selected from the group consisting of a homopolymer of a vinyl monomer having an imidazole group and a copolymer of a vinyl monomer having an imidazole group and another monomer copolymerizable with the vinyl monomer. polymer)
Is used. Examples of such a vinyl polymer include a vinyl monomer having an imidazole group (eg, vinylimidazole, 1-vinyl-3-methylimidazole salt, imidazolinomethylene styrene, 1-vinyl-3-hydroxyethylimidazole salt, 1-vinyl- A homopolymer of 2-methylimidazole); and a vinyl monomer having an imidazole group and at least one other monomer copolymerizable with the vinyl monomer (eg, vinylpyrrolidone, p-styrenesulfonate, p-styrenesulfinic acid) Salt, acrylonitrile, styrene, methyl methacrylate). As the vinyl monomer having an imidazole group, a vinyl monomer having an unsubstituted imidazole group is preferable, and vinylimidazole is particularly preferable. As other copolymerizable monomers, vinylpyrrolidone, p-styrenesulfonate, and p-styrenesulfinate are preferred. The polymer preferably has at least 30 mol%, and preferably at least 40 mol%, of a vinyl monomer unit having an imidazole group.

Preferred examples of the imidazole group-containing polymer are shown below.

[0063]

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[0064]

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[0065]

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[0066]

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Of the above, the polymers a) to f) are particularly preferred.

The transparent image-receiving layer preferably contains polyvinyl alcohol in the range of 20 to 80% by weight of the total polymer, particularly preferably 30 to 70% by weight. Further, the vinylpyrrolidone-based polymer is used in an amount of 5 to 50% by weight of the total polymer.
, And particularly preferably 5 to 30% by weight. Further, the imidazole group-containing polymer is preferably contained in the range of 1 to 60% by weight of the whole polymer, and particularly preferably 2 to 50% by weight. Further, the transparent image receiving layer comprises a polyvinyl alcohol, a vinylpyrrolidone-based polymer and an imidazole group-containing polymer in a weight ratio of 20 to 80:
5 to 50: 1 to 60 (provided that the total of the three polymers is 1
00), particularly preferably 30 to
It is preferable to contain it in a ratio of 70: 5 to 30: 2 to 50. As described above, by using a vinylpyrrolidone-based polymer together with the PVA as the water-soluble resin, and further using the imidazole group-containing polymer in combination, the ink is excellent in ink bleeding, ink transferability, and hardly generates bronze gloss. An image receiving layer can be obtained. In addition, the vinylpyrrolidone-based polymer contributes to improvement in applicability (leveling) when forming the transparent image-receiving layer by coating.

Further, the transparent image-receiving layer for ink-jet recording can be formed of the above-mentioned water-soluble resin and inorganic fine particles having a refractive index of 1.40 to 1.60, which hardly lower the transparency. Examples of the inorganic fine particles include silica fine particles, colloidal silica, calcium silicate, pseudoboehmite, zeolite, kaolinite, halloysite, muscovite, talc, calcium carbonate, and calcium sulfate. As the inorganic fine particles, silica fine particles having an average primary particle diameter of 10 nm or less are preferable. A layer having a large porosity can be obtained by using the silica fine particles and the water-soluble resin in a weight ratio of 1.5: 1 to 10: 1.

The layer of the silica fine particles and the water-soluble resin is preferably formed by connecting secondary particles having a particle diameter of 10 to 100 nm, in which the silica fine particles are aggregated, and more preferably 20 to 50 nm. The porosity of 50 to 80% is preferably 56 to 80%, and the pores forming the voids preferably have an average diameter (average pore diameter) of 5 to 30 nm, particularly 10 to 20 nm. Is preferred. The pore volume (pore volume) is 0.5 to 0.9 m
1 / g is preferable, and 0.6 to 0.9 ml / g is more preferable. Further, the specific surface area of the transparent image receiving layer is 100 to 250.
m ² / g is preferred, especially 120 to ²⁰⁰ m ² / g.
g is preferred.

The above-mentioned transparent image-receiving layer for ink-jet recording is used in order to improve the running property and the blocking resistance of the ink-jet recording sheet in addition to the water-soluble resin and the like.
As a matting agent, colloidal silica, calcium silicate,
It may contain inorganic fine particles such as zeolite, kaolinite, halloysite, muscovite, talc, calcium carbonate, calcium sulfate, boehmite, or organic fine particles such as polymethyl methacrylate fine particles, polystyrene fine particles, and polyethylene fine particles. As inorganic fine particles,
Silica is preferable, and polymethyl methacrylate fine particles are preferable as the organic fine particles. The content of the matting agent in the transparent image receiving layer is preferably 0.01 to 5% by weight.

The crosslinked polymer fine particles, basic polymer latex or water-soluble resin mainly constituting the transparent image receiving layer (transparent color material receiving layer) for ink jet recording may be a single material or a plurality of materials. May be used. The transparent image-receiving layer is mainly composed of the above-mentioned crosslinked polymer fine particles and a water-soluble resin. In addition, the transparent image-receiving layer may contain various inorganic salts and an acid alkali as a pH adjuster in order to enhance the dispersibility of the particles. In addition, various surfactants may be used for the purpose of improving coating suitability and surface quality. Further, a mordant may be used for the purpose of fixing a dye and increasing water resistance in ink jet recording. Further, various matting agents may be included for the purpose of reducing the friction characteristics of the surface. Further, various antioxidants and ultraviolet absorbers may be contained for the purpose of suppressing the deterioration of the coloring material. Further, a fluorescent whitening agent may be included.

The formation of the above-mentioned transparent image-receiving layer for ink-jet recording is carried out by, for example, applying a coating solution containing a water-soluble resin, a crosslinked polymer fine particle or a latex of a basic polymer or a water-soluble resin dispersion of inorganic fine particles to a transparent support. Body surface (opposite surface if white resin layer is provided)
And drying by heating. Coating, for example, air doctor coater, bread coater, rod coater, knife coater, squeeze coater,
It can be performed by a known coating method such as a reverse roll coater or a bar coater. Drying is usually performed at 50 to 180 ° C. for 1 to 20 minutes using a hot air drier.
It is preferable to dry at 0 ° C. for 2 to 15 minutes. The thickness of the transparent image receiving layer is generally 1 to 50 μm, and 5 to 30 μm.
μm is preferred.

The transparent image receiving layer of the electrophotographic recording sheet is generally made of a thermoplastic resin. Such resins generally have a glass transition temperature of 35 ° C. or higher (preferably 4 ° C.).
5 to 120 ° C.). For example, polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin, amino resin, and phenol resin can be used. Organic solvent-soluble polymers, water-soluble polymers, and emulsions may be used. Organic solvent soluble polymers are preferred. When an image is formed on a transparent image receiving layer with a color toner, it is necessary to transfer and fix four color toners, and the polymer of such a transparent image receiving layer needs to have a high cohesive energy. As such a polymer, a polyester resin, particularly an aromatic polyester is preferable. As the aromatic polyester, a repeating unit of at least one dibasic acid component selected from the group consisting of terephthalic acid units and 2,6-naphthalenedicarboxylic acid units, and ethylene glycol units, triethylene glycol units, and bisphenol A A polyester comprising a repeating unit of a dihydric alcohol component containing at least one selected from the group consisting of an ethylene oxide adduct unit and an isopropylene oxide adduct unit of bisphenol A is preferable. Further, when the above polyester is made to be water-soluble or emulsion, it is necessary to introduce a sulfobenzenedicarboxylic acid unit into the polyester. The aromatic polyester (particularly, a polymer having an ethylene oxide adduct unit of bisphenol A) is appropriately softened at the toner fixing temperature, so that the toner is embedded in the image receiving layer, and generally, the toner is fixed to the surface of the image receiving layer and the toner. Since the inclination angle (described later) at the temperature becomes small, a fixed image having almost no unevenness can be obtained.

As the aromatic polyester, a repeating unit of the dibasic acid component is at least one dicarboxylic acid unit selected from the group consisting of a terephthalic acid unit and a 2,6-naphthalenedicarboxylic acid unit, and a dihydric alcohol. A polyester in which the repeating unit of the component contains at least one diol unit selected from the group consisting of an ethylene oxide adduct of bisphenol A and an isopropylene oxide adduct of bisphenol A is preferred. As the aromatic polyester, the repeating unit of the dibasic acid component is preferably at least one dicarboxylic acid unit selected from the group consisting of a terephthalic acid unit and a 2,6-naphthalenedicarboxylic acid unit and a sulfobenzenedicarboxylic acid unit (preferably, And the repeating unit of the dihydric alcohol component is an ethylene glycol unit, a triethylene glycol unit,
Polyesters containing at least one diol unit selected from the group consisting of ethylene oxide adduct units of bisphenol A are preferred.

In the above sulfoaryldicarboxylic acid or its alkyl or hydroxyalkyl ester, the hydroxyalkyl includes a hydroxyethyl group,
A hydroxypropyl group, a hydroxyisopropyl group and a hydroxybutyl group can be mentioned, and the alkyl group can be a methyl group, an ethyl group, an isopropyl group, a propyl group or a butyl group. Particularly, a hydroxyethyl group is preferred. The sulfo group is sodium,
It is preferably a potassium or lithium salt, particularly preferably a sodium salt. The sulfobenzene dicarboxylic acid or its alkyl or hydroxyalkyl ester is preferably isophthalic acid, terephthalic acid or phthalic acid having a sulfonic acid metal base, or a lower alkyl ester or lower hydroxyalkyl ester of these acids, particularly Isophthalic acid having a sulfonic acid metal base or a lower alkyl or lower hydroxyalkyl ester thereof, and isophthalic acid methyl ester or hydroxyethyl ester having a sulfonic acid metal base are preferred.

The ethylene oxide adduct of bisphenol A preferably has an ethylene oxide addition number of 1 to 5 mol (preferably 1 or 2 mol). The above-mentioned bisphenol A adduct of isopropylene oxide has an addition number of isopropylene oxide of 1 to 5 mol (preferably 1
Or 2 mol) is preferred.

The number average molecular weight of the above polyester is 15
The range of 00 to 5000 is preferred. The weight average molecular weight of the polyester is preferably in the range of 2,500 to 15,000. (Weight average molecular weight / number average molecular weight) of the polyester is preferably in the range of 1.2 to 3.0.

The transparent image receiving layer of the electrophotographic recording sheet may contain a matting agent. Since the addition of the matting agent can improve the slipperiness, it has a good effect on abrasion resistance and scratch resistance. Materials used for the matting agent include a fluorine-based resin, a low-molecular-weight polyolefin-based organic polymer (eg, a polyethylene-based matting agent,
Examples of materials used for paraffinic or microcrystalline wax emulsions and substantially spherical matting agents include beaded plastic powders (material examples, cross-linked PMMA, polycarbonate, polyethylene terephthalate, polyethylene or polystyrene), and inorganic fine particles ( For example, SiO ₂ , Al ₂ O ₃ , talc or kaolin)
Can be mentioned. The content of the matting agent is preferably 0.1 to 10% by weight based on the polymer.

The transparent image receiving layer of the electrophotographic recording sheet has a range of 1 × 10 ¹⁰ to 1 × 10 ¹⁴ Ω (25 ° C., 65% RH).
It is preferable to have a surface electrical resistance of (under the conditions).
1 if × less than 10 ¹⁰ Omega, low density of the toner image to the toner amount is obtained is not sufficient when the toner in the transparent image-receiving layer of the electrophotographic recording sheet is transferred, while, 1 × 10 ¹⁴
If it exceeds Ω, an excessive charge is generated at the time of transfer, the toner is not sufficiently transferred, and the density of the image becomes low. During handling of the electrophotographic recording sheet, the sheet tends to be charged with static electricity and dust easily adheres thereto, and misfeeding, double feeding, discharge marks, toner transfer dropping, etc. are likely to occur during copying.

For the purpose of adjusting the transparent image receiving layer to the above-mentioned surface electric resistance, a surfactant may be contained in the image receiving layer. Examples of the surfactant include alkylbenzene imidazole sulfonate, naphthalene sulfonate, carboxylate sulfonate, phosphate, heterocyclic amines, ammonium salts, phosphonium salts and betaine amphoteric salts, or ZnO, SnO ₂ , Al ₂ O
₃ , metal oxides such as In ₂ O ₃ , MgO, BaO and MoO ₃ .

For the transparent image-receiving layer, known materials such as a colorant, an ultraviolet absorber, a cross-linking agent and an antioxidant can be further used, if desired, as long as the properties of the electrophotographic recording sheet are not impaired.

The transparent image-receiving layer is formed, for example, by dispersing or dissolving the polymer, matting agent, antistatic agent and the like in water or an organic solvent, coating the obtained coating solution on the transparent support, and heating the coating solution. It can be carried out by drying. The coating can be performed by a known coating method such as an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, and a bar coater.

The layer thickness of the transparent image receiving layer for electrophotographic recording is preferably in the range of 1 to 8 μm, particularly preferably 2 to 6 μm. When the thickness is less than 1 μm, it is difficult to sufficiently embed the toner into the image receiving layer, and irregularities are easily formed in a halftone portion on the surface of the toner image. If it exceeds 8 μm, cohesive failure tends to occur in the transparent image receiving layer at the time of fixing, and the offset phenomenon tends to occur. Further, in order to obtain a desired surface electric resistance, a conductive layer containing conductive metal oxide particles may be provided between the transparent image receiving layer and the support (or undercoat layer).

The transparent image receiving layer for thermal transfer recording (printing) is generally a resin layer made of a polyolefin resin.
Further, it is preferable that the polyolefin resin comprises hydrophobic particles having an average particle diameter of 2 to 15 μm and a polyolefin resin. The polyolefin resin includes, in addition to a polymer of an olefin (a monomer having an ethylenically unsaturated group) and a copolymer of an olefin and another polymerizable monomer, a high-molecular paraffin substantially equivalent to a polyolefin (eg, Paraffin wax)
Also means. Examples of the polyolefin resin of the image receiving layer include an ethylene / vinyl acetate copolymer, an ethylene / acrylic acid copolymer, an ethylene / sodium acrylate copolymer, an ethylene / acrylic ester copolymer, and an ethylene / vinyl alcohol copolymer. Coalescence, ionomer resin and urethane-modified polyolefin resin can be mentioned. It is preferable that the copolymer resin contains 80 to 90% by weight of an ethylene component (olefin having no hydrophilic group). When the ethylene component is less than 80%, the color density of the highlight portion having the minimum number of dots of the dot having the minimum area decreases. Components other than the ethylene component (olefins having a hydrophilic group) are used in order to provide emulsification suitability.
It is preferably contained in an amount of 0 to 20% by weight. The thickness of the image receiving layer is preferably from 0.01 to 20 μm. The molecular weight of the polyolefin resin is preferably 20,000 or more.

The hydrophobic fine particles can be composed of various hydrophobic substances. Examples of the hydrophobic substance include polyethylene, polypropylene, polyethylene terephthalate, polystyrene, polycarbonate, acrylic resin, methacrylic resin, and polyacrylonitrile. Inorganic fine particles can be used as long as the surface is subjected to a hydrophobic treatment, but organic fine particles are more preferable.
The average particle size of the hydrophobic fine particles is 2 to 15 μm. When the average particle size is less than 2 μm, the improvement of the transportability is insufficient. When the average particle size is larger than 15 μm, the stability of the coating solution is reduced, the state of the coated surface is deteriorated, and the transparency is reduced. The amount of the fine particles used is 0.01
Preferably in the range of 0.5 to 5% by weight.
A range of weight% is more preferred. If it is less than 0.01% by weight, the effect of improving the transportability is insufficient, and if it exceeds 10% by weight, the state of the coated surface is deteriorated and the transparency is reduced. The average particle size of the low molecular weight polyolefin resin particles used as a lubricant is preferably 1 to 3 μm. The weight average molecular weight is preferably from 1,000 to 6,000.

The transparent image receiving layer is preferably provided on an undercoat layer provided on a transparent support and on a conductive layer provided thereon. As a material for forming the undercoat layer, the above-mentioned materials can be used, and gelatin is particularly preferable. As the conductive oxide particles used for the conductive layer, a crystalline metal oxide is preferable. Examples of the conductive crystalline metal oxide include ZnO, SiO ₂ , TiO ₂ , Al ₂ O ₃ , In ₂
O ₃ , MgO, BaO, MoO ₃ , Sb ₂ O ₅ and their composite oxides can be mentioned. The oxide particles have an average particle size of 0.5 μm or less to maintain transparency,
It is preferably 0.2 μm or less. It is preferable to add a binder to the conductive layer in addition to the conductive oxide particles. As binders for the conductive layer, proteins, polysaccharides,
Synthetic hydrophilic colloid, natural resin or synthetic resin can be used. Examples of proteins include gelatin, gelatin derivatives, colloidal albumin and casein. Examples of polysaccharides include cellulose derivatives (eg, carboxymethyl cellulose, hydroxyethyl cellulose, diacetyl cellulose, triacetyl cellulose), agar, sodium alginate, and starch derivatives. Examples of the synthetic hydrophilic colloid include polyvinyl alcohol, poly-N-vinylpyrrolidone, polyacrylic acid copolymer, polyacrylamide, derivatives thereof, partially hydrolyzed products thereof, polyvinyl acetate, polyacrylonitrile, and polyacrylic acid. Esters and their copolymers can be mentioned. Examples of natural resins include rosin, shellac and derivatives thereof. The synthetic resin is used as an emulsion. Examples of synthetic resins include styrene-
Examples thereof include butadiene copolymer, polyacrylic acid, polyacrylate and derivatives thereof, polyvinyl acetate, vinyl acetate / acrylate copolymer, polyolefin and olefin / vinyl acetate copolymer. Carbonate, polyester, urethane or epoxy resins, polyvinyl chloride, vinylidene chloride and organic semiconductors (polypyrrole) can also be used as binders. These binders may be used as a mixture of two or more kinds. The weight ratio between the binder and the metal oxide is preferably 0/100 to 50/50. The conductive layer is preferably provided at a coating amount of 10 to 500 mg / m ² .

The thermal transfer recording sheet (image receiving sheet) of the present invention can be prepared by applying a coating solution containing each of the above components on a transparent support. The coating solution for the transparent image receiving layer and the conductive layer is prepared as a dispersion of the above components by appropriately selecting a solvent. The choice of solvent can be easily made by those skilled in the art. There is no particular limitation on the coating method, and any method can be selected from known methods and adopted. Upon application, a coating aid (eg, saponin, dodecylbenzenesulfonic acid), a hardening material, a coloring agent, an ultraviolet absorber, a heat ray cutting agent, and the like can be appropriately added to the coating solution as needed.

As described above, the recording sheet of the present invention comprising the transparent support, the resin film containing the above white pigment provided thereon, and the transparent image receiving layer provided on the other surface of the transparent support Can be obtained. The glossiness of the surface of the recording sheet of the present invention obtained as described above on the transparent image receiving layer side is preferably at least 75%, particularly preferably at least 80%. The glossiness is a value determined by measuring according to the method described in JIS-P-8142 (test method for 75-degree specular glossiness of paper and paperboard). The parallel light transmittance of the resin film containing a white pigment obtained as described above is generally 2% or less, preferably 1.5% or less. Similarly, the transmittance of the recording sheet thus obtained from the resin film side containing the white pigment is generally 2%.
Or less, and preferably 1.5% or less.

When an image (reflection image) is formed on the recording sheet of the present invention by inkjet recording, a very easy-to-view soft image with reduced graininess can be obtained. That is, when looking at each dot of the image formed on the image receiving layer, the light reflected by the resin film containing the white pigment is scattered due to the presence of the transparent support, so that the outline of the dot becomes unclear and the granularity of the dot becomes large. It is considered that the image quality is reduced and the image becomes easy to see. Also, images obtained by electrophotographic recording, and images obtained by thermal transfer recording,
Similar to the image obtained by the above-described ink jet recording, the graininess is reduced and a very easy-to-read soft image is obtained.

In the recording sheet of the present invention, an ink jet recording sheet, an electrophotographic recording sheet and a thermosensitive recording sheet can be obtained by appropriately selecting the transparent image receiving layer as described above. Using the inkjet recording sheet obtained as described above, an image can be recorded as described below by the image forming method of the present invention.
That is, an image of the water-based ink can be formed on the surface of the transparent image-receiving layer by jetting the water-based ink imagewise onto the transparent image-receiving layer of the inkjet recording sheet. The water-based ink is a color material solution or a color material dispersion in which water containing a water-soluble dye or fine particle pigment is a main component of the solvent. In the above image forming method, a color image is generally formed by repeating the above steps for the number of ink colors. This method can be performed using, for example, a commercially available ink jet (color) printer.

Using the electrophotographic recording sheet obtained as described above, an image can be recorded as follows by the image forming method of the present invention. That is, the following (1)
Steps (1) to (4): a step of imagewise exposing the surface of the photoreceptor to form a latent image; and (2) a step of developing the latent image using a toner comprising a coloring material and a binder resin to form a latent image on the surface of the photoreceptor. Forming an image,
And (3) transferring the image to the transparent image receiving layer of the electrophotographic recording sheet, and (4) pressing the transferred image of the toner with a fixing device (heat roll) heated to the fixing temperature of the toner. Thus, an image can be formed by the step of forming an image on the image receiving layer. In general, a color image can be formed by repeating steps (1) to (3) by the number of toner colors. This method can be performed using, for example, a commercially available indirect dry-type electrophotographic copying machine, full-color electrophotographic copying machine, or various printers.

Using the heat-sensitive recording sheet obtained as described above, an image can be recorded as follows by the image forming method of the present invention. That is, a thermal transfer ink sheet (e.g., a thermal ink ribbon) having a wax-like ink layer is overlaid with a wax-like ink layer on the transparent image-receiving layer of the thermal recording sheet, and heated image-wise (such as a thermal head or the like). To form an ink image by transferring the wax-like ink melted imagewise by heat to the surface of the transparent image receiving layer. In general, a color image can be formed by repeating the above-described steps by the number of colors of the thermal transfer ink sheet. Also,
This method can be performed using, for example, a commercially available thermal transfer copying machine or thermal transfer (color) printer.

[0094]

【Example】

[Example 1] [Preparation of sheet for ink jet recording] (1) Formation of resin film containing white pigment A biaxially stretched polyethylene terephthalate (PET) film having a thickness of 100 µm was fed onto a steel roll and opposed to a steel roll. Polyvinyl chloride film (thickness 50 μm, containing titanium dioxide; back coat film white for signboard makeup system) having an adhesive layer formed on the rubber roll provided
(Fuji Business Supply Co., Ltd.), and the adhesive layer and the PET film were brought into contact with each other and pressed, thereby producing a laminate of the PET film and the white polyvinyl chloride film.

(2) Formation of Undercoat Layer (Composition of Undercoat Layer-Forming Coating Solution) Styrene / butadiene copolymer latex 192 parts by weight (styrene: butadiene: hydroxyethyl acrylate: divinylbenzene: acrylic acid = 63: 33) : 3: 0.5: 0.5 (mol%), solid content: 43% by weight) Styrene / butadiene copolymer latex 54 parts by weight (styrene: butadiene: hydroxyethyl acrylate: acrylic acid = 58: 40: 1: 1 (mol%), solid content: 43% by weight) 73 parts by weight of 2,4-dichloro-6-hydroxy-S-triazine sodium salt (4% by weight aqueous solution) 681 parts by weight of water A coating liquid for forming an undercoat layer was obtained.

The surface of the polyethylene terephthalate film to which the resin film containing the white pigment is bonded, on which the resin film containing the white pigment is not provided, is subjected to corona discharge treatment, and the treated surface is coated with the undercoat layer-forming coating solution. #
3.2 Coating was performed using a wire bar coater and dried at 120 ° C. for 5 minutes using a hot air drier. Thus, an undercoat layer having a dry film thickness of 0.6 μm was formed.

(3) Formation of Transparent Image-Receiving Layer (Composition of Coating Solution for Transparent Image-Receiving Layer) 35% by weight of a 10% by weight aqueous solution of polyvinyl alcohol (Saponification degree: 88%, PVA210, manufactured by Kuraray Co., Ltd.) Cationic crosslinking 15 parts by weight of a 10% by weight aqueous dispersion of polymer fine particles (average particle diameter: 52 nm, polystyrene fine particles cross-linked by an emulsifier having two carbon-carbon double bonds and a quaternary ammonium base, trade name "Mist Pearl C- 150 ", Arakawa Chemical Industries, Ltd.) Matting agent 0.4 part by weight (polymethyl methacrylate fine particles, 4% by weight aqueous dispersion of MX-1000, manufactured by Soken Chemical Co., Ltd.) Melamine resin 4.5 parts by weight ( Sumireze # 613 10% by weight aqueous dispersion, manufactured by Sumitomo Chemical Co., Ltd.) Amine hydrochloride 0.45 parts by weight (ACX-P 5% by weight aqueous dispersion, Tomo Chemical Industry Co., Ltd.) Surfactant 10% by weight aqueous dispersion 1.0 part by weight (Megafac F-144D, manufactured by Dainippon Ink and Chemicals, Inc.) An application liquid was obtained.

This coating solution was applied to the surface of an undercoat layer formed on a polyethylene terephthalate film using a bar coater, and dried at 120 ° C. for 10 minutes using a hot air drier. As a result, a transparent image receiving layer having a dry film thickness of 8 μm was formed. Thus, on polyethylene terephthalate,
An ink jet recording sheet provided with an undercoat layer, a transparent image receiving layer, and a resin film containing a white pigment on the opposite side was obtained.

Example 2 (1) Bonding of a resin film containing a white pigment was performed as follows, and then (2) formation of an undercoat layer and (3) formation of a transparent image receiving layer were the same as in Example 1. To prepare an ink jet recording sheet. (1) Bonding of resin film containing white pigment 60 parts by weight of polyethylene (density 0.98 g / cm ³ ) and 40 parts by weight of titanium dioxide (average particle size: 2.0 μm) are dispersed and mixed by a twin-screw kneading extruder. After that, 30 from T die
After discharging on a chilled roll cooled at 0 ° C. to form a resin film containing a white pigment in a molten state, the surface fed onto a nip roll provided adjacent to the chilled roll was subjected to corona discharge treatment. It was laminated on a biaxially stretched polyethylene terephthalate (PET) film having a thickness of 100 μm to prepare a laminate of a PET film and a white polyethylene film (thickness: 50 μm).

Comparative Example 1 As a support, a layer thickness of 130 μm was used.
(2) Undercoat without bonding a resin film containing a white pigment using a high-gloss opaque support made of a foamed polyethylene terephthalate film containing calcium carbonate of m (trade name: E-68L; manufactured by Toray Industries, Inc.) Formation of the layer and (3) formation of the transparent image receiving layer were performed in the same manner as in Example 1 to prepare an ink jet recording sheet.

The ink-jet recording sheet obtained above was evaluated for its suitability for ink-jet by the following measuring method. (1) Gloss The JIS P-8142 (75-degree specular gloss of paper and paperboard) of a high-gloss support and a recording sheet to which the resin film containing a white pigment obtained in the above Examples and Comparative Examples was bonded was used. Test method), the gloss was measured. That is, six test pieces were prepared and measured using a gloss meter (digital variable-angle gloss meter, manufactured by Suga Test Instruments Co., Ltd.). The average value of the obtained measured values was defined as the glossiness. (2) Parallel light transmittance The haze meter (H) was used for the recording sheet and the resin film containing the white pigment obtained in the above Examples and Comparative Examples.
GM-2DP (manufactured by Suga Test Instruments Co., Ltd.) was used to measure the parallel light transmittance. The measurement was performed by irradiating a parallel light ray from the side of the resin film containing the white pigment of the recording sheet. The transmittance of the resin film containing the white pigment was measured by forming the resin film containing the white pigment on a glass plate and peeling the obtained layer. (3) Image quality (granularity (beading)) Yellow, magenta, cyan, black, blue, green, red (YMCABGR) on a recording sheet by an inkjet color printer (MJ-910; manufactured by Seiko Epson Corporation). Was performed, and the degree of granularity (whether or not pixels became granular and the whole image was felt coarse) of each image was visually evaluated in the following manner. AA: Little graininess is seen BB: Some graininess is seen CC: Graininess is noticeably seen

The results of the above evaluation are shown in Table 1 below.

[0103]

[Table 1] Table 1 画質 Image quality Gloss (%) Transmittance (%) Support sheet White film sheet 実 施 Example 1 AA ^* 99.8 93.6 1.2 1.0 Example 2 AA ^* 99.8 91.6 1.2 1.0 ─────────────── Comparative Example 1 CC 49.0 92.0 − 0.5 ──────────────────── ──────────────── ^* Measured from the opposite side with a resin film containing a white pigment.

[Example 3] [Preparation of electrophotographic recording sheet] In the same manner as in Example 1, a polyethylene terephthalate film bonded with a resin film containing a white pigment was obtained. (2) Formation of undercoat layer (coating solution for forming undercoat layer) Styrene / butadiene copolymer latex (as solid content) 3.8 parts by weight (styrene: butadiene: hydroxyethyl methacrylate: divinylbenzene = 67:30: 2.5: 0.5; weight ratio) 2,4-dichloro-6-hydroxy-1,3,5-0.1 parts by weight Triazine sodium salt (crosslinking agent) Tin dioxide fine particles 2.0 parts by weight (SN- 88; average particle size = 88 nm; manufactured by Ishihara Sangyo Co., Ltd.) Pure water 94.1 parts by weight

The surface of the polyethylene terephthalate film to which the resin film containing the white pigment was bonded, on which the resin film containing the white pigment was not provided, was subjected to corona discharge treatment. 2.
It was applied using an 8-wire bar coater and dried at 180 ° C. for 1 minute using a hot air drier. Thus, an undercoat layer having a dry film thickness of 0.25 μm was formed.

(3) Formation of Transparent Image-Receiving Layer (Composition of Coating Solution for Forming Transparent Image-Receiving Layer) * 11.6 parts by weight of polyester resin having the following composition (as solid content): 0.06 parts by weight of crosslinked PMMA matting agent (MR-7G; average particle size: 7 μm, manufactured by Soken Chemical Co., Ltd.) 72.9 parts by weight of methyl ethyl ketone

* Polyester resin composition 上 記 Polyester composition (mol%) Number average Weight average TP BAEO BAPO Molecular weight Molecular weight (Mn) (Mw) ─────────────────────────────────── ─ 100.0 75.0 25.0 2100 4100 ──────────────────────────────────── Remarks) TP: Terephthalic acid unit, BAEO: Bisphenol A
Diethylene oxide adduct units (bisphenol A
With one ethylene oxide added to both ends of
BAPO: bisphenol A diisopropylene oxide adduct unit (one isopropylene oxide added to both ends of bisphenol A)

The coating solution for forming an image receiving layer is applied to the surface of the undercoat layer using a bar coater # 10, and the coating solution is applied at 90 ° C. for 1 hour.
Dried for minutes. The layer thickness was 2.0 μm. Thus, an electrophotographic recording sheet having a resin film containing a white pigment on one side of a polyethylene terephthalate film and an undercoat layer and a transparent image receiving layer formed on the other side was prepared.

Example 4 A polyethylene terephthalate film to which a resin film containing a white pigment was bonded was obtained in the same manner as in Example 2. Next, (2) formation of an undercoat layer and (3) formation of a transparent image receiving layer were performed in the same manner as in Example 3 to prepare an electrophotographic recording sheet.

Comparative Example 2 As a support, a layer thickness of 130 μm was used.
(2) using a high-gloss opaque support made of a foamed polyethylene terephthalate film containing calcium carbonate of m (trade name: E-68L; manufactured by Toray Industries, Inc.) without providing a resin film containing a white pigment containing fine particles; The formation of the undercoat layer and the formation of the transparent image receiving layer (3) were carried out in the same manner as in Example 3 to prepare an ink jet recording sheet.

The properties of the obtained electrophotographic recording sheet were evaluated by the following methods. (1) Gloss and (2) Parallel light transmittance were measured in the same manner as above. (3) Image quality (granularity (beading)) Full-color electrophotographic copying machine (A color 620;
Fuji Xerox Co., Ltd.))
Performs gradation printing of yellow, magenta, cyan, black, blue, green, and red (YMCABGR), and visually confirms the granularity of the image at each gradation (whether or not the whole image is coarse because the pixels are granular). The degree was evaluated as follows. AA: Little graininess is seen BB: Some graininess is seen CC: Graininess is noticeably seen

The results of the above measurement are shown in Table 2 below.

[0113]

[Table 2] Table 2 画質 Image quality Gloss (%) Transmittance (%) Support sheet White film sheet ──────────────────────────────────── Example 3 AA 99 0.7 94.0 1.2 1.0 Example 4 AA 99.7 92.0 1.2 1.0 ───────────── Comparative Example 2 CC 49.0 92.0 − 0.5 ────────────────────── ──────────────

Example 5 In the same manner as in Example 1, a polyethylene terephthalate film to which a resin film containing a white pigment was bonded was obtained. The surface of the polyethylene terephthalate film provided with the resin film containing the white pigment, on which the resin film containing the white pigment was not provided, was subjected to corona discharge treatment, and a gelatin undercoat layer was provided on the treated surface. A liquid having the following composition was applied to the undercoat layer as a conductive layer in an amount of 5.2 ml / m ^{2 and} dried at 130 ° C. for 5 minutes.

(Coating Liquid for Forming Conductive Layer) Gelatin 4.5 parts by weight 0.5 parts by weight of tin oxide doped with antimony having an average particle size of 0.2 μm (the amount of antimony is 5% by weight based on tin oxide) Methanol 70 parts by weight Parts Water 30 parts by weight Polyethylene oxide surfactant 0.01 parts by weight

A 10 ml / m ² solution having the following composition was applied as a transparent image receiving layer on the conductive layer, and dried at 130 ° C. for 5 minutes.

(3) Formation of Transparent Image-Receiving Layer (Composition of Coating Solution for Transparent Image-Receiving Layer) Chemipearl S120 (manufactured by Mitsui Petrochemical Industries, Ltd.) 12 parts by weight ethylene (85% by weight) / sodium acrylate (15% by weight) Glass transition point: 110 ° C. MP2700M (manufactured by Soken Chemical Co., Ltd.) 0.05 parts by weight Polymethyl methacrylate resin particles having an average particle size of 5.8 μm Chemipearl WF640 (manufactured by Mitsui Petrochemical Co., Ltd.) 1 part by weight low molecular weight polyolefin resin particles) methanol 55 parts by weight water 33 parts by weight

As described above, a thermal transfer recording sheet having a resin film containing a white pigment on one side of a polyethylene terephthalate film and an undercoat layer, a conductive layer and a transparent image receiving layer formed on the other side was obtained.

Example 6 In the same manner as in Example 2, a polyethylene terephthalate film to which a resin film containing a white pigment was bonded was obtained. Next, corona discharge treatment,
Formation of a gelatin undercoat layer, formation of a conductive layer, and (3) formation of a transparent image-receiving layer were performed in the same manner as in Example 5 to prepare a thermal transfer recording sheet.

Comparative Example 3 As a support, a layer thickness of 130 μm was used.
m using a high-gloss opaque support made of a foamed polyethylene terephthalate film containing calcium carbonate (trade name: E-68L; manufactured by Toray Industries Inc.), without providing a resin film containing a white pigment, corona discharge treatment, gelatin A thermal transfer recording sheet was prepared in the same manner as in Example 5 except that the formation of the undercoat layer, the formation of the conductive layer and the formation of (3) the transparent image receiving layer were performed.

The properties of the obtained thermal transfer recording sheet were evaluated by the following methods. (1) Gloss and (2) Parallel light transmittance were measured in the same manner as above. (3) Image quality (granularity (beading)) Thermal transfer copier (EC-10, manufactured by Fuji Xerox Co., Ltd.)
To the recording sheet, yellow, magenta, cyan, black, blue, green, red (YMCAB)
GR), and the degree of granularity of the image (whether or not the image becomes coarse due to the formation of particles) was visually evaluated at each gradation as follows. AA: Little graininess is seen BB: Some graininess is seen CC: Graininess is noticeably seen

The results of the above measurement are shown in Table 3 below.

[0123]

[Table 3] Table 3 ──────────────────────────────────── Image quality Gloss (%) Transmittance (%) Support sheet White film sheet ──────────────────────────────────── Example 5 AA 99 8.8 93.8 1.2 1.0 Example 6 AA 99.8 91.8 1.2 1.0 ───────────── Comparative Example 3 CC 49.0 92.0 − 0.5 ────────────────────── ──────────────

[0124]

When an image is formed on the recording sheet of the present invention by ink jet recording, a very easy-to-read soft image with reduced graininess can be obtained. Further, the images obtained by electrophotographic recording and the images obtained by thermal transfer recording also become soft images that have reduced graininess and are very easy to see, similarly to the images obtained by the above-mentioned ink jet recording.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a basic configuration of a recording sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Transparent support 12 Transparent image receiving layer 13 Resin film containing white pigment

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 15/22 106 B41M 5/26 101H

Claims (9)

[Claims] 1. A resin film containing a white pigment formed independently or formed from a molten state on the support is joined to one surface of the transparent support, and the other surface of the transparent support is further bonded. A recording sheet for forming a reflection image, comprising a transparent image receiving layer provided on the recording medium. 2. The recording sheet according to claim 1, wherein the glossiness on the transparent image receiving layer side of the recording sheet is 75% or more. 3. The recording sheet according to claim 1, wherein the resin film containing the white pigment has a parallel light transmittance of 2% or less. 4. The image-receiving layer according to claim 1, wherein the transparent image-receiving layer is an image-receiving layer for inkjet recording comprising a water-soluble resin and a basic polymer, crosslinked polymer fine particles, imidazole group-containing polymer or inorganic fine particles. Recording sheet. 5. The recording sheet according to claim 1, wherein the transparent image-receiving layer is an image-receiving layer for recording electrophotography made of polyester. 6. The recording sheet according to claim 1, wherein the transparent image receiving layer is an image receiving layer comprising a polyolefin resin and hydrophobic fine particles for thermal transfer recording. 7. An image forming method comprising jetting aqueous ink onto the transparent image receiving layer of the recording sheet according to claim 4 to form an image of the aqueous ink on the surface of the transparent image receiving layer. 8. The following steps (1) to (4): (1) a step of imagewise exposing the surface of the photoreceptor to form a latent image, and (2) a step of forming the latent image from a coloring material and a binder resin. A step of forming an image on the surface of the photoreceptor by developing with a toner; and (3) a step of transferring the image to the image receiving layer of the recording sheet according to claim 5; and (4) a transfer of the toner. Forming an image on the image receiving layer by pressing the image with a fixing device heated to the fixing temperature of the toner. 9. A heat transfer ink sheet having a wax-like ink layer, the wax-like ink layer is superposed on the image-receiving layer of the recording sheet according to claim 6, and heated image-wise.
An image forming method comprising forming an ink image by transferring the wax-like ink melted imagewise by the heat to the surface of the image receiving layer.