JP5348854B2 - Electrophotographic recording paper and recorded matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electrophotographic recording paper having excellent image recording quality such as density, tone and gradation, and also excellent fixing property, water resistance and durability. <P>SOLUTION: The electrophotographic recording paper is manufactured by laminating a recording layer made of a synthetic resin film and an ultraviolet intercepting layer, on at least one surface of a base material layer made of a paper material having water resistance, wherein the ultraviolet intercepting layer is laminated between the base material layer and the recording layer. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The electrophotographic recording paper of the present invention can be suitably used for color recording by an electrophotographic copying machine, a laser printer, etc., and has excellent recording quality such as density, color tone, gradation, etc., and excellent fixability, water resistance, and durability. In particular, the present invention relates to an electrophotographic recording paper having excellent light resistance.

  In recent years, copying machines and printers have made remarkable progress, and not only in terms of price, but also in terms of performance such as recording quality and recording speed, they are dramatically improving. For this reason, printed materials such as posters, catalogs, and pamphlets that were previously created by printing machines can now be created more easily and quickly while maintaining conventional print quality using copiers and printers. became. Such recording by a copying machine or a printer can be used particularly suitably when a variety of printed materials are produced quickly.

  Among various copying machines and printers, copying machines and printers employing an electrophotographic method, in particular, copying machines and printers using a semiconductor laser are excellent in that they can perform high resolution and high speed recording. Although there are problems with electrophotographic colorization, the size of the apparatus is increased because a plurality of developing devices are required, and the color tone is slightly inferior because a pigment is used as a toner color material. The problems are being solved by downsizing the apparatus and improving the materials such as toner and recording paper.

  Regarding the improvement of recording paper, in electrophotographic recording paper (Patent Document 1) in which a synthetic resin film having a coating layer is laminated on at least one side of a base material layer made of a paper material having water resistance, a conventional pulp paper is used. An electrophotographic recording paper having better recording quality, fixability, water resistance and durability than the electrophotographic recording paper is devised and put into practical use.

However, the conventional electrophotographic recording paper in which a synthetic resin film having a coating layer is laminated on at least one side of a base material layer made of a paper material having water resistance is superior in recording quality, fixability, water resistance and durability. However, when used outdoors for a long time, the recording paper itself (especially water-resistant paper material) is yellowed by sunlight, and the sharpness of the recorded image tends to be impaired. For this reason, in particular, outdoor posters for advertising products and outdoor signboards for displaying store menus have the disadvantage that they cannot withstand long-term use because they impair the image.
JP 2002-91049 A

The present invention has made it a problem to solve these problems of the conventional recording paper.
In other words, the present invention can be suitably used for color recording by an electrophotographic recording system using an electrophotographic copying machine, a laser printer, etc., has excellent recording quality such as density, color tone, gradation, etc., and has excellent fixability, water resistance, and durability. An object of the present invention is to provide an excellent electrophotographic recording paper, particularly an electrophotographic recording paper having excellent light resistance.

  As a result of diligent studies to solve these problems, the present inventor has found that the intended purpose can be achieved by the electrophotographic recording paper having a specific structure, and solves the above problems and The invention has been completed.

That is, the present invention comprises a recording layer made of a synthetic resin film and an ultraviolet blocking layer laminated on at least one side of a base material layer made of water-resistant paper, and the ultraviolet blocking layer is interposed between the substrate layer and the recording layer. The present invention provides an electrophotographic recording sheet characterized in that it is laminated.
In the electrophotographic recording paper of the present invention, the recording layer preferably has a coating layer on the side opposite to the base material layer. The water-resistant paper material used for the base layer is preferably one having a water absorption range of 0 to 50 g / m ² according to the Cobb method based on JIS P8140: 1998. Specifically, diazo photosensitive paper base paper, photographic printing Paper base paper, resin-impregnated paper, resin-coated paper, sulfated paper, pseudosulfuric paper, water-resistant paper, oil-resistant paper, processed paper selected from the group consisting of waterproof paper, or olefins containing inorganic and / or organic fine powders A resin film is particularly preferable.

The ultraviolet blocking layer preferably contains at least one ultraviolet absorber selected from the group consisting of benzotriazole, benzophenone, salicylate, cyanoacrylate, nickel, and triazine. The content of the ultraviolet absorber is preferably 1% by weight to 50% by weight.
The synthetic resin film used for the recording layer preferably contains 50% to 100% by weight of a thermoplastic resin having a melting point of 180 ° C. to 300 ° C. and 50% by weight or less of the filler. Preferably, the polyester-based resin preferably contains polyethylene terephthalate.
The coating layer used for the recording layer is a toner receiving layer and is preferably the outermost layer of the electrophotographic recording paper.

As one aspect of the present invention, a recording layer and an ultraviolet blocking layer are laminated on both sides of the base material layer, and an ultraviolet blocking layer is preferably laminated between the base material layer and the recording layer, respectively. It is also preferable to laminate a recording layer and an ultraviolet blocking layer on one side of the base material layer, and a protective layer made of a synthetic resin film on the other side of the base material layer.
The electrostatic capacity of these electrophotographic recording papers is preferably in the range of 10 to 300 pF / cm ² .
The present invention includes an electrophotographic recording paper in the form of a label in which an adhesive layer is further laminated on one surface (non-recording surface) of the electrophotographic recording paper, and recorded matter using the electrophotographic recording paper. including.

  When color recording is performed on the electrophotographic recording paper of the present invention by the electrophotographic recording method, an image having excellent recording quality such as density, color tone, gradation and the like can be obtained. Further, the electrophotographic recording paper of the present invention exhibits good fixability, water resistance and durability, and is particularly excellent in light resistance, and therefore is suitable for outdoor use.

  Hereinafter, the electrophotographic recording paper and recorded matter of the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

  The electrophotographic recording paper of the present invention is formed by laminating a recording layer made of a synthetic resin film and an ultraviolet blocking layer on at least one side of a base material layer made of a water-resistant paper material. It is characterized by being laminated between the material layer and the recording layer. FIG. 1 and FIG. 2 show a preferred embodiment of the electrophotographic recording paper of the present invention having such characteristics. The electrophotographic recording paper 1 of the present invention shown in FIG. 1 has a recording layer 3 made of a synthetic resin film laminated on one side of a base material layer 2 made of a paper material having water resistance. Between these, an ultraviolet blocking layer 5 is provided. As shown in FIG. 1, in the electrophotographic recording paper 1 of the present invention, a coating layer 4 can be provided on the surface of the recording layer 3, and an adhesive layer 7 is interposed on the opposite surface of the base material layer 2. The protective layer 6 and the like can be provided. The electrophotographic recording paper 1 of the present invention shown in FIG. 2 is formed by laminating a recording layer 3 made of a synthetic resin film having a coating layer 4 on both sides of a base material layer 2 made of water-resistant paper. An ultraviolet blocking layer 5 is provided between the layer 2 and the recording layer 3. Hereinafter, each layer of the electrophotographic recording paper of the present invention will be described in detail.

[Base material layer]
The base material layer used for the electrophotographic recording paper of the present invention is a support for the electrophotographic recording paper. The base material layer imparts physical strength such as bending elasticity and tensile elasticity to electrophotographic recording paper, whiteness and opacity as recording paper, and provides water resistance and durability together with a synthetic resin film. To do.

As the base material layer, a water-resistant paper material having a water absorption by the Cobb method based on JIS P8140: 1998 in the range of 0 to 50 g / m ² is preferable. Water absorbing degree is more preferably 0~40g / m ^2, and particularly preferably 1 to 30 g / m ^2.
Specifically, it is a base paper that is coated or impregnated with a coating agent that imparts water resistance to pulp base paper, or a base paper that is coated or fused with a synthetic resin having water resistance to pulp base paper. Processed paper such as photographic paper base paper, resin-impregnated paper, resin-coated paper, sulfuric acid paper, pseudosulfuric paper, water-resistant paper, oil-resistant paper, and waterproof paper can be used.
Specific examples include olefin resin films and synthetic paper containing inorganic and / or organic fine powders.
The thickness of the base material layer is preferably 20 to 300 μm, and more preferably 50 to 150 μm.

The olefin resin film contains inorganic and / or organic fine powder together with the olefin resin. As a composition of an olefin resin film, it is preferable to contain 35 to 99 weight% of olefinic resins, and 1 to 65 weight% of inorganic and / or organic fine powders. More preferably, it contains 50 to 95% by weight of olefinic resin and 5 to 50% by weight of inorganic and / or organic fine powder.
Examples of the olefin resin contained in the olefin resin film include ethylene resins such as high density polyethylene and medium density polyethylene, propylene resin, poly (4-methylpent-1-ene), ethylene-cyclic olefin copolymer Olefin-based resins such as coalescence can be applied. Further, a mixture of two or more of these resins may be applied. Among these, high-density polyethylene and propylene-based resin are preferably applied from the viewpoints of cost, water resistance, and chemical resistance.
The propylene-based resin is a propylene homopolymer, mainly composed of polypropylene and propylene having isotactic, syndiotactic and various stereoregularities, and ethylene, butene-1, hexene-1, heptene- And a copolymer with an α-olefin such as 1,4-methylpentene-1. This copolymer may be a binary, ternary or quaternary system, and may be a random copolymer or a block copolymer.

  Examples of the inorganic fine powder contained in the olefin-based resin film include, for example, calcium carbonate, calcined clay, silica, diatomaceous earth, talc, titanium oxide, barium sulfate, alumina, and the like, and the average particle size thereof is 0.01 to A thing of 15 micrometers can be applied. As the organic fine powder, one having a melting point or glass transition temperature higher than the melting point of the main component resin serving as a matrix of the olefin resin film and incompatible with the olefin resin can be applied. Specifically, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, nylon-6, nylon-6,6, homopolymer of cyclic olefin, copolymer of cyclic olefin and ethylene, etc., melting point 120 ° C. to 300 ° C. Or those having a glass transition temperature of 120 ° C to 280 ° C.

The structure of the olefin-based resin film includes a single-layer structure, a two-layer structure of a base layer and a surface layer, a three-layer structure in which surface layers are laminated on both sides of the base layer, or another resin film layer between the base layer and the surface layer. Any multilayer structure may be used, and these multilayer structures can be produced by a known method such as a coextrusion method, a melt lamination method, or a dry lamination method.
When the olefin resin film has a multilayer structure having a base layer and a surface layer, the base layer contains 45 to 98% by weight of olefin resin and 2 to 55% by weight of inorganic and / or organic fine powder. preferable. The surface layer contains 25 to 100% by weight of the olefin resin and preferably contains 75% by weight or less of inorganic and / or organic fine powders or does not contain them. In a more preferred form, the base layer contains 50 to 95% by weight of the olefin resin, 5 to 50% by weight of inorganic and / or organic fine powder, and the surface layer contains 30 to 99% by weight of the olefin resin. It contains 1 to 70% by weight of inorganic and / or organic fine powder.

  The olefin-based resin film may further contain a heat stabilizer, a light stabilizer, a dispersant, a lubricant and the like as necessary. For example, a stabilizer such as sterically hindered phenol, phosphorus and amine is used as a heat stabilizer in an amount of 0.001 to 1% by weight, and a stabilizer such as sterically hindered amine, benzotriazole and benzophenone is used as a light stabilizer. As a dispersant for 0.001 to 1% by weight of inorganic fine powder, a silane coupling agent, a higher fatty acid such as oleic acid or stearic acid, metal soap and the like may be added in an amount of 0.01 to 4% by weight.

The olefin resin film that can be used in the base material layer of the present invention is preferably a stretched film that is stretched and molded in at least a uniaxial direction in the molding process. Those having fine pores inside by stretching can improve the opacity of the recording paper and can improve the capacitance.
As a method for stretching the resin film, a conventionally known method can be applied. For example, longitudinal stretching using a difference in peripheral speed of a roll group, rolling using a plurality of rolls (longitudinal stretching), lateral stretching using a tenter, the longitudinal Sequential biaxial stretching combining stretching and transverse stretching, simultaneous biaxial stretching using a combination of a tenter and a linear motor, simultaneous biaxial stretching using a tubular method, simultaneous biaxial stretching using a pantograph type stretching machine, etc. it can. The temperature at the time of extending | stretching is suitably selected according to the kind of olefin resin to be used, and an extending | stretching process. Specifically, in the case of a propylene homopolymer (melting point 155 to 167 ° C.), 110 to 164 ° C., in the case of high density polyethylene (melting point 121 to 134 ° C.), 80 to 120 ° C., 2 to 60 from the melting point. It is preferable to set the temperature to a lower temperature. The stretching speed is preferably 20 to 350 m / min.

  A draw ratio is not specifically limited, It selects suitably by the objective and the characteristic of the olefin resin to be used. For example, when propylene homopolymer or propylene-based copolymer is used and uniaxially stretched, it is preferably 1.2 to 12 times, more preferably 2 to 10 times, and when biaxially stretched, The area magnification is preferably 1.5 to 60 times, more preferably 10 to 50 times. When other olefinic resins are used and uniaxially stretched, the ratio is preferably 1.2 to 10 times, more preferably 2 to 5 times, and when biaxially stretched, the area ratio is preferably 1. 5 to 20 times, more preferably 4 to 12 times. After stretching, heat treatment (annealing treatment) is performed as necessary.

  The olefin-based resin film containing inorganic and / or organic fine powder is stretched under the above conditions to form fine voids (holes) inside the film and have an opacity (JIS P-8138) of 85. % Or more, preferably 90% or more, and the porosity defined by the following formula (1) is 10 to 60%, preferably 15 to 45%. it can.

（式中、ρ₀は樹脂フィルムの真密度を示し、ρは樹脂フィルムの密度を示す）
延伸フィルムの空孔率が１０％未満では、電子写真記録用紙の白色化、不透明化、軽量化への寄与が乏しく、逆に空孔率が６０％を越えては、電子写真記録用紙の強度（引張強度、曲げ強度）が低くなり、いずれも実用的ではない。

(Wherein ρ ₀ represents the true density of the resin film and ρ represents the density of the resin film)
When the porosity of the stretched film is less than 10%, the contribution to whitening, opacification, and weight reduction of the electrophotographic recording paper is poor. Conversely, when the porosity exceeds 60%, the strength of the electrophotographic recording paper is low. (Tensile strength and bending strength) are low, and neither is practical.

The thickness of the olefin resin film containing the inorganic and / or organic fine powder is preferably in the range of 20 to 300 μm, more preferably 50 to 150 μm, as described above. If the thickness of the film is 20 μm or more, it tends to be easy to produce a stretched film having voids, and if it is 300 μm or less, it tends to be easily marketed as a wound roll.
It is preferable to use an olefin resin film having a capacitance of 4 to 1000 pF / cm ² .

[Recording layer]
The recording layer used in the electrophotographic recording paper of the present invention means that the electrophotographic recording paper has heat resistance, durability, toner acceptability, suitable capacitance, etc. so that information recording by an electrophotographic recording method can be suitably performed. It is a layer that characterizes.

The recording layer is made of a synthetic resin film.
As the synthetic resin film, a synthetic resin film having a water resistance and an insulating property with a thickness of usually 5 to 100 μm, preferably 12 to 50 μm is applied. Synthetic resins imparting water resistance and insulation include crystalline ethylene resins such as high density polyethylene, medium density polyethylene, and low density polyethylene, crystalline propylene resins, poly (4-methylpent-1-ene), ethylene -Crystalline olefin resins such as cyclic olefin copolymers; polyamide resins such as nylon-6, nylon-6,6, nylon-6,10, nylon-6,12; polyethylene terephthalate and other monomers and other components Copolymer, polyethylene naphthalate, polylactic acid, aliphatic polyester and other thermoplastic polyester resins; polycarbonate, atactic polystyrene, isotactic polystyrene, syndiotactic polystyrene, polyphenylene sulfide, and other thermoplastic resins Is mentioned. These may be used in combination of two or more.

  Among these thermoplastic resins, it is preferable to use a resin having a melting point in the range of 180 ° C. to 300 ° C. as a main component from the viewpoint of imparting heat resistance suitable for the electrophotographic recording method. Accordingly, the thermoplastic resin that can form the synthetic resin film of the present invention includes poly (4-methylpent-1-ene), polyamide resin, polyester resin, polycarbonate, isotactic polystyrene, syndiotactic polystyrene, and polyphenylene sulfide. Etc. are preferred. When a resin having a melting point of less than 180 ° C. is used as the main component of the recording layer, the recording layer is deformed or melted by heat in the toner fixing process, and the electrophotographic recording paper itself is greatly deformed, In some cases, it may stick to the toner fixing device (such as a heat-fusing roll) and damage the recording device. If the melting point exceeds 300 ° C., film molding becomes difficult, the thickness of the film tends to fluctuate, waviness occurs in the electrophotographic recording paper, and uniform information recording becomes difficult, which is not preferable. In addition, the main component of the present invention occupies 50% to 100% by weight of the entire synthetic resin film, and if it is less than 50% by weight, the characteristics are impaired, and the desired performance of the synthetic resin film of the present invention is achieved. Does not demonstrate. Examples of subcomponents include other thermoplastic resins and fillers.

Among these thermoplastic resins, it is particularly preferable to use a polyester resin as a main component. Examples of the polyester include at least bifunctional carboxylic acids such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, bis-α, β (2-chlorophenoxy) ethane-4,4′-dicarboxylic acid, adipic acid, and sebacic acid. Mention may be made of polyesters obtained by polycondensation of one kind and at least one kind of glycol such as ethylene glycol, triethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol and the like. Furthermore, the polyester obtained by adding the polycarboxylic acid which can be polycondensed to said bifunctional carboxylic acid and glycol, and carrying out polycondensation can be mentioned.
Among these polyester-based resins, polyethylene terephthalate obtained by polycondensation of terephthalic acid and ethylene glycol can easily obtain a film having a uniform thickness, can be easily processed, and can impart an appropriate capacitance. Is preferable.

  Since the electrophotographic recording paper of the present invention is formed by laminating a base material layer made of a water-resistant paper material and a recording layer made of a synthetic resin film having water resistance, the water resistance can be greatly improved. Can do.

[Coating layer]
The recording layer used in the electrophotographic recording paper of the present invention preferably has a coating layer. The coating layer is a toner receiving layer and is preferably the outermost layer of the electrophotographic recording paper.
Examples of the coating layer include 40-100% by weight of a binder resin made of urethane resin, vinyl chloride-vinyl acetate copolymer, acrylic urethane resin, polyether urethane, polyester urethane, and inorganic fine powder 0-60. The one consisting of% by weight is applied.
As the urethane resin, a urethane resin composed of an organopolysiloxane polyol having at least two or more hydroxyl groups and another polymer polyol can be suitably used. As the acrylic urethane resin, urethane resins disclosed in Japanese Patent Publication No. 53-32386 and Japanese Patent Publication No. 52-73985 can be suitably used. As the inorganic fine powder, heavy calcium carbonate, calcined clay, titanium oxide, barium sulfate, diatomaceous earth, or the like can be used. The coating amount of the above components in the coating layer is preferably 0.1 to 20 g / m ² , more preferably 0.5 to 8 g / m ² in terms of the solid content after drying.

[UV blocking layer]
The ultraviolet blocking layer used in the electrophotographic recording paper of the present invention is a layer provided between the base material layer and the recording layer, and is a layer containing an ultraviolet absorber or an ultraviolet absorber and an ultraviolet reflector. The electrophotographic recording paper of the present invention effectively suppresses discoloration (yellowing) of the inner base material layer by the ultraviolet blocking layer, and enables long-term use outdoors.

When an ultraviolet blocking layer is provided outside the recording layer (for example, provided on the coating layer, or provided between the coating layer and the synthetic resin film), water resistance, solvent resistance, and ink adhesion are preferably reduced. Absent. Further, when the recording layer itself is an ultraviolet blocking layer (for example, when an ultraviolet absorber or the like is kneaded and mixed in a synthetic resin film), the moldability of the recording layer is deteriorated and the uniformity of the film thickness is impaired. The purpose of the period cannot be achieved. Therefore, the desired effect of the present invention can be achieved by providing the ultraviolet blocking layer as a separate layer between the base material layer and the recording layer.

  The ultraviolet absorber that can be used for the ultraviolet blocking layer is one that absorbs light having a wavelength of any one of 280 to 400 nm. For example, any of benzotriazole, benzophenone, salicylate, cyanoacrylate, nickel, and triazine, or a mixture thereof can be used, either low molecular weight type or high molecular weight type.

  Specific examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-). Butylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-amylphenyl) benzotriazole, 2- (2′-hydroxy-3′-t-butyl-5′-) Methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′-(1-methyl-1-phenylethyl) -5′-1,1,3,3 tetramethylbutylphenyl) Examples include benzotriazole, 2- (2′-hydroxy-3′-t-butyl-5 ′-(2-octyloxycarbonyl) ethylphenyl) benzotriazole. Specific examples of the benzophenone ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyl. Examples thereof include oxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone. Specific examples of salicylate-based UV absorbers include phenyl salicylate, 4-t-butylphenyl salicylate, 2,4-di-t-butylphenyl-3 ′, 5′-di-t-butyl-4′- Examples thereof include hydroxybenzoate. Specific examples of the cyanoacrylate ultraviolet absorber include ethyl (β, β-diphenyl) cyanoacrylate, 2-ethylhexyl (β, β-diphenyl) cyanoacrylate, and the like. Specific examples of nickel-based ultraviolet absorbers include [2,2-thiobis (4-t-octylphenolate)]-n-octylamine nickel salt, [2,2-thiobis (4-t-octylphenol). Lat)]-2-ethylhexylamine nickel salt, nickel dibutyldithiocarbamate and the like. Specific examples of the triazine-based ultraviolet absorber include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol. Among these, benzotriazole-based ultraviolet absorbers are preferable, and 2- (2′-hydroxy-3 ′-(1-methyl-1-phenylethyl) -5′-1,1,3,3-tetramethylbutylphenyl is preferable. ) Benzotriazole (CAS No. 73936-91-1), 2- (2′-hydroxy-3′-t-butyl-5 ′-(2-octyloxycarbonyl) ethylphenyl) benzotriazole (CAS No. 127519-) 17-9) is preferred.

The ultraviolet reflector that can be used in the ultraviolet blocking layer is one that reflects and / or scatters light having a wavelength of any one of 280 to 400 nm. For example, any one of zinc oxide, titanium oxide, cerium oxide, tungsten oxide, strontium titanate, or a mixture thereof.
The ultraviolet absorber and the ultraviolet reflector may be used alone or in combination.

The ultraviolet blocking layer of the present invention desirably contains at least one type of ultraviolet absorber. When the ultraviolet blocking layer is formed from an ultraviolet reflector component, discoloration of the electrophotographic recording paper itself is reduced when the printed matter of the electrophotographic recording paper of the present invention is used outdoors, but the toner or coating on the recording paper is reduced. The amount of ultraviolet rays applied to the layer increases, and toner discoloration and deterioration are likely to occur, and the sharpness of the recorded image and the adhesion of the image are likely to decrease.
The content of the ultraviolet absorber in the ultraviolet blocking layer is preferably 1 to 50% by weight, more preferably 2 to 40% by weight, and still more preferably 5 to 30% by weight. If the amount of the ultraviolet absorber is 1% by weight or more, a clear recorded image tends to be easily obtained due to the discoloration suppressing effect of the electrophotographic paper itself. If it is 50% by weight or less, the water resistance and solvent resistance of the ultraviolet blocking layer tend to be easily obtained.

The ultraviolet blocking layer may be a single layer or a multilayer structure of two or more layers. It is also possible to add an ultraviolet absorber to the adhesive layer for adhering the base material layer and the recording layer and use it as an ultraviolet absorbing layer.
As a method for forming the ultraviolet blocking layer separately from the adhesive layer, co-extrusion with the base layer and / or recording layer, melt lamination to the base layer and / or recording layer, base layer and / or recording are possible. Examples include coating on a layer. Among these, a method of preparing a coating material obtained by mixing the known ultraviolet light absorber and / or ultraviolet reflecting agent with a known binder component and applying the coating material to a base material layer or a recording layer is preferable. Specific examples of known binder components include oxidized starch, etherified starch, methoxycellulose, carboxymethylcellulose, hydroxyethylcellulose, casein, gelatin, soy protein, polyvinylhydrin, polyacrylamide, vinyl alcohol, polyacrylic acid, and ester. Urethane resin, ether urethane resin, acrylic urethane resin, terpene resin, petroleum resin, ethylene-vinyl acetate copolymer resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, vinylidene chloride resin, vinyl chloride-vinylidene chloride copolymer resin , Acrylic acid ester copolymer resin, methacrylic acid ester copolymer resin, butyral resin, silicone resin, polyester resin, nitrocellulose resin, styrene-acrylic copolymer resin, styrene-butyl resin Diene copolymer resin. Among them, polyacrylic acid, ester urethane resin, ether urethane resin, acrylic urethane resin, ethylene-vinyl acetate copolymer resin, acrylic ester copolymer resin, methacrylic ester copolymer resin, styrene-acrylic copolymer resin, styrene- A butadiene copolymer resin is preferred.

The thickness of the ultraviolet blocking layer is preferably in the range of 0.1 to 30 μm, more preferably 0.3 to 25 μm, and still more preferably 0.5 to 20 μm. For example, the thickness may be 0.5 to 10 μm, 0.7 to 8 μm, 1 to 7 μm, or 2 to 6 μm. If the wall thickness is 0.1 μm or more, a clear recorded image tends to be easily obtained due to the effect of suppressing discoloration of the electrophotographic paper itself. If the thickness is 30 μm or less, the thickness tends to be uniform, and a recorded image without distortion tends to be easily obtained.
When the ultraviolet blocking layer has a multilayer structure of two or more layers, the thickness of each layer may be the same or different. For example, the first layer in contact with the base material layer may be a thin layer, and the second layer provided on the first layer may be thick. For example, the first layer may be thinner than the second layer by 0.5 to 10 μm, preferably 1 to 5 μm. For example, the first layer may be less than 0.1 to 3 μm, the second layer may be 3 to 15 μm, the first layer may be 0.5 to 2.5 μm, and the second layer may be 3 to 6 μm.
The ultraviolet blocking layer used in the electrophotographic recording paper of the present invention is preferably colorless and transparent or white for use.

[Adhesive layer]
When the electrophotographic recording paper of the present invention is formed from a base material layer and a recording layer, an adhesive layer may be used for bonding them, and the layers may be laminated therethrough. For the bonding, an adhesive such as a solvent-based adhesive or a hot-melt adhesive is provided as an adhesive layer on the base material layer or the recording layer by a technique such as coating, spraying, melt extrusion laminating, and the like. It can be performed by a usual method such as dry lamination or melt lamination using a heat-fusible film or a melt-extruded film.
Examples of the solvent-based adhesive include resin components composed of acrylic resins, urethane resins, ether resins, ester resins, epoxy resins, rubber resins, silicone resins, ABS resins, etc. Typical examples are liquid adhesives in the form of a solution type or an emulsion type, which can be dissolved, dispersed, emulsion-dispersed and diluted in the phase by using a liquid and can be applied.

These adhesives are applied by a die coater, bar coater, comma coater, lip coater, roll coater, gravure coater, spray coater, blade coater, reverse coater, air knife coater or the like. Thereafter, smoothing is performed as necessary, and an adhesive layer is formed through a drying step.
These adhesives are generally applied such that the basis weight is 0.5 to 25 g / m ^2, and an adhesive layer is provided.

When an adhesive is used, the adhesive is applied to the surface of the paper material that is the base layer, and then a synthetic resin film that is the recording layer is overlaid and pressure bonded with a pressure roll, or the recording layer The adhesive may be applied to the back surface of the synthetic resin film, and then the paper material as the base material layer may be stacked and pressure bonded with a pressure roll.
Examples of the hot-melt adhesive include polyolefin resins such as polyethylene and ethylene / vinyl acetate copolymers, polyamide resins, polybutyral resins, urethane resins, and the like.
When using a hot-melt adhesive, apply by beating, curtain coating, slot coating, etc. on the surface of the paper material that is the base material layer, or use the paper material that is the base material layer. What is necessary is just to laminate | stack by extruding in the shape of a molten film from the die | dye on the surface, and then stacking | stacking the synthetic resin film which is a recording layer, and pressurizing-bonding with a press roll.

Moreover, it is also possible to form an ultraviolet blocking layer having adhesiveness by containing the above-mentioned ultraviolet absorber and / or ultraviolet reflector in these adhesives.
Accordingly, the layer structure including the ultraviolet blocking layer includes a recording layer / ultraviolet blocking layer (also serving as an adhesive layer) / base layer, recording layer / ultraviolet blocking layer / adhesive layer / base layer, recording layer / adhesion. An agent layer / ultraviolet ray blocking layer / base material layer, recording layer / adhesive layer / ultraviolet ray shielding layer / adhesive layer / base material layer, and the like can be adopted.

[Protective layer]
As one aspect of the electrophotographic recording paper of the present invention, a recording layer and an ultraviolet blocking layer can be laminated on one side of the base material layer, and a protective layer made of a synthetic resin film can be provided on the other side of the base material layer. It is.
As a synthetic resin film used for the protective layer, a synthetic resin film having a water resistance and an insulation property of a thickness of usually 5 to 100 μm, preferably 12 to 50 μm is applied. The kind of the synthetic resin used for the protective layer is not particularly limited. For example, ethylene resins such as high density polyethylene and medium density polyethylene, propylene resins such as polypropylene, homopolymers of α-olefins having 2 to 8 carbon atoms such as poly (4-methylpent-1-ene), ethylene- Olefin resins such as α-olefin 2-5 types of copolymers such as cyclic olefin copolymers; polyamide resins such as nylon-6, nylon-6,6, nylon-6,10, nylon-6,12 ; Polyethylene terephthalate and copolymers obtained by copolymerizing other components with the same monomer; thermoplastic polyester resins such as polyethylene naphthalate, polylactic acid and aliphatic polyester; polycarbonate; atactic polystyrene, isotactic polystyrene, syndiotactic Polystyrene resins such as polystyrene; polyphenylene A material substantially equivalent to the synthetic resin film of the recording layer, such as sulfide, can be used. Furthermore, you may mix and use those 2 or more types.

  In the case of using the adhesive to constitute the electrophotographic recording paper, the adhesive is applied to both sides of the paper material that is the base layer, and then the synthetic resin film that is the recording layer is applied to the front surface. A synthetic resin film as a protective layer is overlaid and pressure bonded with a pressure roll, or an adhesive is applied to the back surface of the synthetic resin film as a protective layer, and then a paper material as a base material layer is overlaid. It is only necessary to apply pressure bonding with a pressure roll. When the hot melt adhesive is used, it is laminated on the surface and back surface of the paper material, which is the base material layer, by extruding it from a die in the form of a molten film, and the synthetic resin film, which is the recording layer, on the front surface, and the protective layer on the back surface. A certain synthetic resin film may be superposed and pressure bonded with a pressure roll.

[Electrophotographic recording paper]
The thickness of the electrophotographic recording paper of the present invention is usually 70 to 500 μm, preferably 75 to 400 μm, and more preferably 80 to 300 μm. Moreover, the basic weight is 70-500 g / m < ² > normally, Preferably it is 75-400 g / m < ² >, More preferably, it is 80-300 g / m < ² >.

  The electrophotographic recording paper of the present invention may have an adhesive layer formed on one side of the outermost layer. The type and thickness (coating amount) of the pressure-sensitive adhesive layer can be variously selected depending on the type of adherend, the environment in which it is used, the strength of adhesion, and the like. The pressure-sensitive adhesive layer can be formed by coating and drying a commonly used solvent-based or water-based pressure-sensitive adhesive. As the adhesive, synthetic polymer adhesives such as natural rubber, synthetic rubber, and acrylic can be used. In the form of a solution dissolved in an organic solvent, a dispersion dispersed in an aqueous solvent, an emulsion, etc. Can be used. Further, in order to improve the opacity of the electrophotographic recording paper, the adhesive may contain a pigment such as titanium white. The pressure-sensitive adhesive layer can be formed by coating it on the silicone-treated surface of release paper or process paper in a solution state, which can be transferred onto the electrophotographic recording paper, or directly on the electrophotographic recording paper. It can also be formed by coating. The adhesive is applied by a die coater, bar coater, roll coater, lip coater, gravure coater, spray coater, blade coater, reverse coater, air knife coater or the like. Further, smoothing is performed as necessary, and a pressure-sensitive adhesive layer is formed through a drying step. Although the thickness of an adhesive layer can be variously selected according to the intended purpose of a label, it is 2-30 micrometers normally, Preferably it is 5-20 micrometers. The electrophotographic recording paper of the present invention may further have a release paper on the surface of the pressure-sensitive adhesive layer. There is no problem if a release paper is provided at the time of electrophotographic recording, and the release paper is removed for use on an adherend. As the release paper, generally common paper can be used. For example, high-quality paper or kraft paper can be used as it is or by calendering, resin coating or film lamination, glassine paper, coated paper, plastic film or the like subjected to silicone treatment. When the release paper is applied to an electrophotographic recording paper, in order to improve the peelability from the pressure-sensitive adhesive layer, it is common to use a release paper that has been subjected to silicone treatment on the surface that contacts the pressure-sensitive adhesive layer.

[Capacitance measurement]
Electrophotographic recording sheet of the present invention preferably has a capacitance per unit electrode area is 10~300pF / cm ^2, more preferably 12~250pF / cm ^2, at 15~200pF / cm ² More preferably it is. If the electrostatic capacity of the electrophotographic recording paper is 10 pF / cm ² or more, the toner transfer rate tends to be increased and a practical print density tends to be easily obtained. If the capacitance of the electrophotographic recording paper is 300 pF / cm ² or less, a clear and gradation recorded image tends to be easily obtained. That is, if the electrostatic capacity is 300 pF / cm ² or less, the charge of the toner is not stabilized and the toner is scattered before being heat-fixed by a heat roll, and a clear image cannot be obtained. However, there is a tendency that the paper becomes dirty due to the reattachment of the scattered toner, or a problem that an excessive toner is transferred and an image having no gradation is generated. In addition, there is a tendency that the paper remains charged indefinitely, and the problem of deterioration in paper alignment and paper handling after printing tends not to occur.

If the electrostatic capacity of the electrophotographic recording paper is within a preferable range, the recording paper can be sufficiently charged to hold an electrostatic charge, and the toner adhering to the photosensitive drum after exposure can be transferred and adhered efficiently. Therefore, it is easy to obtain good recording quality such as density, color tone, gradation, etc. of the printed matter and toner fixing property.
The electrostatic capacity includes a parallel equivalent capacity or a series equivalent capacity. In general, the measurement method for the equivalent capacitance is selected according to the measurement frequency range. When the measurement frequency is 10 Hz or less, an ultra-low frequency bridge is used. When the measurement frequency is 10 Hz to 3 MHz, a transformer bridge is used. When the measurement frequency exceeds 1 MHz, a parallel T-type bridge, a high-frequency shelling bridge, a Q meter, and a resonance method are used. The standing wave method and the cavity resonance method are used. Further, it is possible to measure the voltage / current vector with respect to the circuit component with respect to the AC signal of the measurement frequency, and to measure it with an LCR meter or the like that calculates the capacitance from this value.

As a measuring device for measuring the capacitance of recording paper, a sample is sandwiched between a flat plate-like electrode and a flat guard electrode arranged in parallel at a constant pressure, and a voltage of about 5 V can be applied, and the measurement frequency is A measuring device that can be arbitrarily selected is preferred. According to such a measuring machine, by changing the frequency, the frequency dependence of the sample can be grasped, and it can be used as an index of the appropriate usage range. The sample is preferably as uniform as possible and has a smooth surface. If the surface condition is poor, a gap (air layer) is formed between the sample and the electrode, giving a large error to the measured value. In this case, in order to complete electrical contact between the sample and the electrode, it is preferable to apply a silver conductive paint or perform vacuum deposition. Specific examples of measuring devices include Agilent Technologies' “4192A LF IMPEDANCE ANALYZER”, Yokogawa Electric's “LCR Meter 4274A”, Hioki Electric's “HIOKI 3522 LCR High Tester”, and the like. It is done.
For the measurement of the electrostatic capacity of the electrophotographic recording paper of the present invention, “4192A LF IMPEDANCE ANALYZER” manufactured by Agilent Technologies was used. Under the environmental conditions of a temperature of 23 ° C. and a relative humidity of 50%, A sample larger than the electrode diameter was sandwiched between a counter electrode having a diameter of 56 mm, a voltage of 5 V was applied, measurement was performed at a frequency in the range of 10 Hz to 1 MHz, and a measurement value at a frequency of 300 Hz was used as a representative value.

[Recording device]
The electrophotographic recording paper of the present invention can be favorably color-recorded by an electrophotographic recording apparatus such as a copying machine or a laser printer. In the electrophotographic color recording method, (1) an intermediate transfer method in which an intermediate transfer is performed for each color, a plurality of colors are transferred to an intermediate transfer member, and then transferred and developed on a sheet. (2) two or more photosensitive members are used, A tandem method that transfers and develops multiple colors on paper one by one, and (3) a tandem + transfer method that uses two or more photoconductors, transfers multiple colors one by one to an intermediate transfer body, and then transfers and develops them on paper. There are three types. In the present invention, in particular, (2) and (3) are collectively referred to as a tandem system. The electrophotographic recording paper of the present invention can be used for the intermediate transfer system of (1), but is preferably used for the tandem system of (2) and (3). In the method (1), in the case of a small-sized electrophotographic copying machine or the like, the electrophotographic recording paper may be squeezed while being transported in the apparatus and may be difficult to use. The tandem methods (2) and (3) are compatible with high-speed operation, and are preferable because the electrophotographic recording paper is hardly squeezed during conveyance because of the structure of the apparatus.

  The electrophotographic recording paper of the present invention may be subjected to ordinary printing such as oil-based offset printing, UV offset printing, gravure printing, flexographic printing, etc. before recording using the recording apparatus. If necessary, a management bar code may be printed by such printing, thermal transfer method, or electrophotographic method. The electrophotographic recording paper of the present invention is printed on the entire surface of the synthetic resin film, which is the recording layer, on the back surface (opposite to the coating layer) before being laminated with the base material layer in order to promote sales and visibility. Alternatively, partial printing may be performed. Similarly, full surface printing or partial printing may be performed on the surface of the base material layer on which the recording layer is laminated before the recording layer is laminated.

[Recordings]
The recorded material using the electrophotographic recording paper of the present invention includes POP cards (posters, stickers, displays, etc.), store information (pamphlets, company information, product writing, menus, etc.), underlays (lunch mats, table mats, stationery supplies) Etc.), manuals (various manuals for duties, operations, operations, etc., process charts, timetables, etc.), charts (nautical charts, weather charts, charts, ruled line charts, etc.), catalogs, cards (price cards, point cards, members cards, Various membership cards, student IDs, licenses, employee IDs, entrance / exit certificates, association IDs, ID cards, student attendance cards, book cards, examination cards, management cards, parking licenses, ski tickets, CDs, MD title cards , CD, MD index card, photo card, etc.), panel, plate (alternative to metal plate), bromide, preservation document Word processor documents, various lists, appraisals, certificates, important documents, certificates, etc.), picture books, drawings (architecture drawings, civil engineering site screens, etc.), maps (nautical charts, route maps, outdoor maps, etc.), commuter pass, store prices Table, mountain climbing guide, business card, lost child tag, cooking recipe, information board (sales guidance, direction / destination guidance, sweets / food, etc.), gardening POP (hanging label, feed label, etc.), schedule table, road Signs (funerals / housing exhibition places, etc.), circular boards, room name tags, school records, display boards (forbidden to enter, forest road work, etc.), stakes, nameplates, calendars (with images), simple whiteboards, postcards, greetings Cards, flyers, picture books, picture-story shows, portable timetables, album picture diaries, paperwork (paper craft), copy manuscripts, round fans, megaphones, mouse pads, bookmarks, pet toilets, packaging materials ( Paper, boxes, bags, etc.), coasters, flower pots, non-laminate prints, label lighter replacement prints, adhesive labels, tags (air tags, IC tags, triage tags), etc. It is. In particular, it can be suitably used for applications based on outdoor use.

  Hereinafter, the present invention will be described more specifically with reference to production examples, examples and comparative examples. In addition, the material, usage-amount, ratio, processing content, and processing procedure shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[Example of recording layer production]
15 parts by weight of 2-hydroxyethyl methacrylate, 50 parts by weight of methyl methacrylate, 35 parts by weight of ethyl acrylate, and 100 parts by weight of toluene were charged into a three-necked flask equipped with a stirrer, a reflux condenser, and a thermometer. 0.6 parts by weight of '-azobisisobutyronitrile was introduced as an initiator and polymerized at 80 ° C. for 4 hours. The resulting solution was a 50% toluene solution of a hydroxyl group-containing methacrylate polymer having a hydroxyl value of 65. Next, 100 parts by weight of this solution was mixed with 30 parts by weight of a 20% methyl ethyl ketone solution of vinyl chloride-vinyl acetate copolymer (manufactured by Shin Daiichi Vinyl Co., Ltd., trade name: ZEST C150ML), hexamethylene diisocyanate (Nippon Polyurethane Industry ( Co., Ltd., trade name: Coronate HL) 20 parts by weight of 75% ethyl acetate solution, heavy calcium carbonate powder having an average particle size of 1.5 μm (Bihoku Flour Chemical Co., Ltd., trade name: Softon 1500) 20 Blended in parts by weight. Butyl acetate was added to this mixture to adjust the solid content to 35%, and a coating solution for a coating layer was obtained.
As a synthetic resin film for the recording layer, a polyethylene terephthalate film having a thickness of 25 μm (trade name: Lumirror, manufactured by Toray Industries, Inc.) was used. The coating solution prepared on this surface had a dry solid content of 1 g / m ^2. And then cured at 80 ° C. for 1 hour to form a recording layer having a coating layer.

[Production example of UV blocking layer and adhesive layer]
The compositions shown in Table 1 were blended so that each component after drying would have the concentration shown in Table 1 to prepare UV blocking layer paints (paints 1-3) and adhesive layer paints. The ultraviolet blocking layer and adhesive layer used in each example and comparative example were obtained by coating and drying.

[Example]
Example 1
On the back surface of the recording layer obtained in the above recording layer production example (opposite surface of the coating layer), an ultraviolet blocking layer coating material (paint-1) was applied so that the dry solid content was 4 g / m ² . It was dried at 60 ° C. for 1 minute to provide an ultraviolet blocking layer.
Separately, OTP base paper for photographic paper (manufactured by Oji Paper Co., Ltd., Cobb method water absorption 24.8 g / m ² , basis weight 175 g / m ² ) was used as a base material layer, and these were layered and pressed with a pressure roll Glued.
Furthermore, as a protective layer, a polyethylene terephthalate film having a thickness of 19 μm (manufactured by Teijin DuPont Films Co., Ltd., trade name: Melinex 377) was used, and an adhesive layer coating material (paint) was dried at 4 g / m ² . It was coated so as to be dried at 60 ° C. for 1 minute, and an adhesive layer was provided.
The back side of the base material layer (opposite side of the recording layer) and the surface of the adhesive layer of the protective layer are overlapped and pressure-bonded with a pressure roll to form a coating layer / polyethylene terephthalate film (25 μm) / An electrophotographic recording paper having a thickness of 220 μm and a capacitance of 26 pF / m ² was obtained by laminating an ultraviolet blocking layer (4 μm) / OTP base paper for printing paper (170 μm) / adhesive layer / polyethylene terephthalate film (19 μm). .

(Example 2)
On the back surface of the recording layer obtained in the above recording layer production example (opposite surface of the coating layer), an ultraviolet blocking layer coating material (paint-1) was applied so that the dry solid content was 4 g / m ² . It was dried at 60 ° C. for 1 minute to provide an ultraviolet blocking layer.
Separately, an OTP base paper for photographic paper (manufactured by Oji Paper Co., Ltd., Cobb method water absorption 24.8 g / m ² , basis weight 175 g / m ² ) was used as a base material layer. The recording layers are overlapped and pressure-bonded with a pressure roll, and the coating layer / polyethylene terephthalate film (25 μm) / UV blocking layer (4 μm) / OTP base paper for printing paper (170 μm) / UV blocking layer / polyethylene terephthalate film (25 μm) ) / An electrophotographic recording paper having a thickness of 225 μm and a capacitance of 25 pF / m ² obtained by laminating coating layers was obtained.

(Example 3)
On the back surface of the recording layer obtained in the above recording layer production example (opposite surface of the coating layer), an ultraviolet blocking layer coating material (paint-3) was applied so that the dry solid content was 2 g / m ² . The film was dried at 70 ° C. for 30 seconds to provide an ultraviolet blocking layer.
Separately, OTP base paper for photographic paper (manufactured by Oji Paper Co., Ltd., Cobb method water absorption 24.8 g / m ² , basis weight 175 g / m ² ) was used as the base material layer, and the adhesive layer coating ( The paint was applied so that the dry solid content was 4 g / m ² and dried at 60 ° C. for 1 minute to provide an adhesive layer.
Next, the adhesive layer on the base material layer and the ultraviolet ray blocking layer on the recording layer are overlaid so that they are in contact with each other, and are pressure-bonded with a pressure roll, and the coating layer / polyethylene terephthalate film (25 μm) / ultraviolet ray blocking layer (2 μm) / Adhesive layer / OTP base paper for photographic paper (170 μm) / Adhesive layer / UV blocking layer (2 μm) / Polyethylene terephthalate film (25 μm) / Thickness 230 μm, electrostatic capacity 24 pF / m ² electrophotographic recording papers were obtained.

Example 4
On the back surface of the recording layer obtained in the above recording layer production example (opposite surface of the coating layer), an ultraviolet blocking layer coating material (paint-3) was applied so that the dry solid content was 2 g / m ² . After drying at 70 ° C. for 30 seconds, the coating material for UV blocking layer (Paint-2) was further applied so that the dry solid content was 4 g / m ^2, and dried at 60 ° C. for 1 minute. (2 layers) were provided.
Separately, OTP base paper for photographic paper (manufactured by Oji Paper Co., Ltd., Cobb method water absorption 24.8 g / m ² , basis weight 175 g / m ² ) was used as the base material layer, and the adhesive layer coating ( The paint was applied so that the dry solid content was 4 g / m ² and dried at 60 ° C. for 1 minute to provide an adhesive layer.
Next, the adhesive layer on the base material layer and the ultraviolet ray blocking layer on the recording layer are laminated so that they are in contact with each other, and pressure bonding is performed with a pressure roll, and the coating layer / polyethylene terephthalate film (25 μm) / ultraviolet ray blocking layer (two layers) : 6 μm in total) / Adhesive layer / OTP base paper for printing paper (170 μm) / Adhesive layer / UV blocking layer (2 layers: 6 μm in total) / Polyethylene terephthalate film (25 μm) / Thickness of laminated coating layer An electrophotographic recording paper having 230 μm and a capacitance of 24 pF / m ² was obtained.

(Comparative Example 1)
The electrophotographic recording paper of Example 1 of JP 2002-91049 A was used.

[Test example]
(Evaluation of recording quality)
Using a color laser printer (manufactured by Casio Co., Ltd., trade name: N4-612II), four colors of yellow, cyan, magenta, and black are used for the recording layers of the electrophotographic recording paper obtained from the above examples and comparative examples. Test image recording with color toner was carried out, and the recording quality such as density, color tone, gradation and the like was visually judged according to the following evaluation criteria. The results are shown in Table 2.
○: Good in density, color tone and gradation.
Δ: The recording density is slightly low.
X: Density, color tone, or gradation is inferior and cannot be used.

(Evaluation of light resistance)
The recording paper recorded by the above evaluation was fixed outdoors with the recording surface facing southward and left standing for one month, and the change in image sharpness was visually determined according to the following evaluation criteria. The results are shown in Table 2.
○: The density, color tone, and gradation of the recording paper are not changed, and the light resistance is good.
X: Discoloration occurs in the recording paper and the color tone and gradation are impaired.

  The results of the evaluation are as shown in Table 2, and the electrophotographic recording paper of the present invention has no change in density, color tone, gradation, etc. when used outdoors, and is a conventional water-resistant paper material. It is understood that the recording quality and the light resistance are excellent as compared with an electrophotographic recording paper in which a synthetic resin film having a coating layer is laminated on at least one side of the base material layer.

FIG. 3 is a partially enlarged cross-sectional view of an embodiment of the electrophotographic recording paper of the present invention. FIG. 6 is a partially enlarged cross-sectional view of another embodiment of the electrophotographic recording paper of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrophotographic recording paper 2 Base material layer 3 Recording layer 4 Coating layer 5 Ultraviolet ray blocking layer 6 Protective layer 7 Adhesive layer

Claims (16)

A recording layer made of a synthetic resin film and an ultraviolet blocking layer are laminated on at least one side of a base material layer made of a paper material having water resistance,
Laminating the ultraviolet blocking layer between the base material layer and the recording layer,
The ultraviolet blocking layer contains 2 to 40% by weight of at least one ultraviolet absorber selected from the group consisting of benzotriazole, benzophenone, salicylate, cyanoacrylate, nickel, and triazine. Characteristic electrophotographic recording paper.   2. The electrophotographic recording paper according to claim 1, wherein the recording layer has a coating layer on the side opposite to the base material layer. The paper material having water resistance used for the base material layer is a paper material having a water absorption in a range of 0 to 50 g / m ² according to a Cobb method based on JIS P8140: 1998. The electrophotographic recording paper described.   The water-resistant paper material used for the substrate layer is composed of diazo photosensitive paper base paper, photographic printing paper base paper, resin-impregnated paper, resin-coated paper, sulfuric acid paper, pseudosulfuric paper, water-resistant paper, oil-resistant paper, and waterproof paper. The electrophotographic recording paper according to any one of claims 1 to 3, wherein the electrophotographic recording paper is a processed paper selected from a group.   The electrophotographic image according to any one of claims 1 to 3, wherein the water-resistant paper material used for the base material layer is an olefin resin film containing inorganic and / or organic fine powder. Recording sheet.   The electrophotographic recording paper according to any one of claims 1 to 5, wherein the ultraviolet blocking layer has a thickness of 2 to 6 µm. The UV blocking layer is an adhesive layer, or the UV blocking layer is oxidized starch, etherified starch, methoxycellulose, carboxymethylcellulose, hydroxyethylcellulose, casein, gelatin, soy protein, polyvinylhydrin, polyacrylamide, vinyl alcohol. , Polyacrylic acid, ester urethane resin, ether urethane resin, acrylic urethane resin, terpene resin, petroleum resin, ethylene-vinyl acetate copolymer resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, vinylidene chloride resin, vinyl chloride -Vinylidene chloride copolymer resin, acrylic ester copolymer resin, methacrylic ester copolymer resin, butyral resin, silicone resin, polyester resin, nitrocellulose resin, styrene-acrylic copolymer Resins and styrene - electrophotographic recording sheet as claimed in any one of claims 1 to 6, characterized in that it contains a binder selected from the group consisting of butadiene copolymer resin.   8. The synthetic resin film used for the recording layer contains 50 to 100% by weight of a thermoplastic resin having a melting point of 180 to 300 [deg.] C. and 50% by weight or less of a filler. The electrophotographic recording paper described in 1.   The electrophotographic recording paper according to claim 8, wherein the thermoplastic resin contains a polyester-based resin.   The electrophotographic recording paper according to claim 9, wherein the polyester resin contains polyethylene terephthalate.   The electrophotographic recording paper according to claim 1, wherein the coating layer used for the recording layer is a toner receiving layer and is an outermost layer of the electrophotographic recording paper.   The recording layer and the ultraviolet blocking layer are laminated on both surfaces of the base material layer, and the ultraviolet blocking layer is laminated between the base material layer and the recording layer, respectively. The electrophotographic recording paper of item 1.   13. The recording layer and the ultraviolet blocking layer are laminated on one side of the base material layer, and a protective layer made of a synthetic resin film is laminated on the other side of the base material layer. The electrophotographic recording paper according to any one of the above. The electrophotographic recording paper according to claim 1, wherein the electrophotographic recording paper has a capacitance of 10 to 300 pF / cm ² .   The electrophotographic recording paper which further laminated | stacked the adhesive layer on one side of the electrophotographic recording paper as described in any one of Claims 1-14.   A recorded matter using the electrophotographic recording paper according to any one of claims 1 to 15.

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