JP2000003062A - Electrophotographic image receiving sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a conveyance trouble by successively forming a polyolefin layer and at least one toner image receiving layer on the front side of base paper and successively forming a polyolefin layer and at least one heat resistant layer comprising a hydrophilic resin on the rear side. SOLUTION: Any hydrophilic resin may be used as the material of the heat resistant layer if it can withstand a fixing temp. but a water-soluble polymer, in particular >=10 wt.% water-soluble polymer is preferably contained. The toner image receiving layer is preferably a coating of about 0.1-100 μm thickness contg. a material which ensures the sticking of a toner and can fix and hold the toner by heating at the time of fixation optionally in combination with a binder for the material. A polymer as the toner receiving material preferably contains a polyester resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image-receiving sheet in which a support comprises a polyolefin layer on the surface of a base paper, and a heat-resistant layer or an image-receiving layer is provided on the back polyolefin layer.

[0002]

2. Description of the Related Art A color electrophotographic method is a dry process, has a high printing speed, and can output to general-purpose paper (plain paper or high-quality paper). However, if you want to output image information such as faces and landscapes as photographs, general-purpose paper is inferior in texture and gloss,
There is a need for special paper for photographic applications. JP-A-8-
Japanese Patent No. 21164 describes a recording paper similar to a photographic printing paper having a polyolefin layer on the front and back of a base paper.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic image-receiving sheet which can be used for photographic applications and does not cause a transport failure. Another object of the present invention is to provide recording paper having excellent heat resistance.

[0004]

According to the present invention, a base paper, a polyolefin layer and a toner image receiving layer are sequentially provided on the surface of the base paper in order, and a polyolefin layer and a hydrophilic resin are sequentially provided on the back side of the base paper. This is achieved by an electrophotographic image receiving sheet provided with at least one heat-resistant layer. Further, the toner image receiving layer described above was achieved by an electrophotographic image receiving sheet containing a polyester resin. In addition, the above-mentioned heat-resistant layer is made of polyvinyl alcohol and / or
Or an electrophotographic image-receiving sheet containing gelatin. Further, the above-mentioned heat-resistant layer was achieved by an electrophotographic image-receiving sheet containing organic and / or inorganic fine particles. Further, it is achieved by a base paper, a front polyolefin layer provided on the front surface of the base paper, a back polyolefin layer provided on the back surface, and an electrophotographic image-receiving sheet provided with a toner image receiving layer on both surfaces of the front and back polyolefin layers. In addition, double-sided printing has become possible. In addition, the electrophotographic image-receiving sheet of the present invention surprisingly improved image quality deterioration due to roughness or lack of an image.

[0005]

Next, a heat-resistant layer comprising the hydrophilic resin of the present invention will be described. As the material of the heat-resistant layer on the back surface used in the present invention, any material can be used as long as it can withstand the fixing temperature, but it is preferable that the material contains a water-soluble polymer, and more preferably 10% by weight of the water-soluble polymer. % Is preferable. As the binder or the main component constituting the layer, the above-mentioned polymer for an image receiving layer or a water-soluble polymer, or another organic solvent-soluble polymer or a water-soluble polymer can be used. As the water-soluble polymer, a water-soluble polymer having a group capable of undergoing a cross-linking reaction with a hardener is preferable, and among them, polyvinyl alcohol and gelatins are preferably used.

The heat resistant layer may be composed of two or more layers.
The total thickness of the heat-resistant layer is 0.01 to 50 μm, especially 0.0 to 50 μm.
A range of 5 to 20 μm is preferred.

The image receiving sheet for electrophotography of the present invention is provided with an image receiving layer. The image receiving layer adheres the toner, and when fixing,
It is preferable that the film has a thickness of about 0.1 to 100 μm containing a substance capable of fixing and holding the toner by heat (hereinafter, referred to as an accepting substance) alone or together with its binder substance. Examples of the polymer which is a typical example of the toner receptive substance include the following resins. The polymer preferably contains a polyester resin, more preferably 20% by weight or more of the polyester resin.

(A) Those having an ester bond. Dicarboxylic acid components such as terephthalic acid, isophthalic acid, and succinic acid (these dicarboxylic acid components include sulfonic acid groups,
A carboxyl group or the like) and a polyester resin obtained by condensation of ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, bisphenol A, etc., polymethyl methacrylate, polybutyl methacrylate, polymethyl acrylate, poly Polyacrylate resin or polymethacrylate resin such as butyl acrylate,
Polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, styrene-methacrylate copolymer resin, vinyl toluene acrylate resin, and the like. Specifically, JP-A-59-101395 and JP-A-63-7971
Nos. 63-7972, 63-7973, 60
No. 2,294,862.
Also, commercially available products include Byron 290, Byron 200, Byron 280, Byron 300, Byron 103, Byron GK-140, and Byron GK-13 manufactured by Toyobo.
0, Kao ATR-2009, ATR-2010, Unitika Elitel UE3500, UE3210, X
A-8153, Polyester TP-2 manufactured by Nippon Synthetic Chemical
20, R-188 and the like can be used.

(B) Polyurethane resin and the like. (C) Polyamide resin and the like. Urea resin and the like. (D) Polysulfone resin and the like. (E) polyvinyl chloride resin, polyvinylidene chloride resin,
Vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl propionate copolymer resin, and the like. (F) Polyol resins such as polyvinyl butyral, and cellulose resins such as ethyl cellulose resin and cellulose acetate resin. (C) Polycaprolactone resin, styrene-maleic anhydride resin, polyacrylonitrile resin, polyether resin, epoxy resin, phenol resin and the like. (H) Polyolefin resins such as polyethylene resins and polypropylene resins, copolymer resins of olefins such as ethylene and propylene with other vinyl monomers, and acrylic resins. In addition to the above synthetic resins, mixtures or copolymers thereof can also be used.

In the present invention, the image receiving layer of the electrophotographic image receiving sheet may have a structure in which a receptive substance is dispersed in a water-soluble binder and carried. A water-soluble polymer having a group capable of undergoing a cross-linking reaction with a hardener is preferable, and among them, polyvinyl alcohol and gelatins are preferably used.
Further, the receptive substance may form a coating film in a water-soluble binder so as to maintain a granular shape. In this case, the coating material is selected from those which form a coating film at a temperature at which the toner is thermally fixed. Is preferred. As the water-soluble binder used in this case, a known water-soluble polymer can be used. As a method for dispersing the receptive substance in the water-soluble binder, any of the known dispersion methods for dispersing a hydrophobic substance in a water-soluble polymer can be used. Typically, a method in which a solution in which a receptive substance is dissolved in an organic solvent immiscible with water is mixed with an aqueous solution of a water-soluble binder and emulsified and dispersed, and a latex of the receptive substance (polymer) is mixed with an aqueous solution of a water-soluble binder And the like.

The water-soluble polymer does not specify its composition, bonding structure, molecular structure, molecular weight, molecular weight distribution, or form as long as it is a water-soluble polymer. Examples of water-solubilizing groups of the polymer include a hydroxyl group, a carboxylic acid group,
Examples include an amino group, an amide group, and an ether group. Examples of the water-soluble polymer include Research Disclosure No. 17,643, p. 26, 18,716, p. 651, 307, 105, p. 873-874 and JP-A-64-13,546, (71). Pages to pages (75). Specifically, for example, vinyl pyrrolidone-vinyl acetate copolymer, styrene-vinyl pyrrolidone copolymer, styrene-maleic anhydride copolymer,
Water-soluble polyester, water-soluble polyurethane, water-soluble nylon, and water-soluble epoxy resin can be used. Water-dispersible resins such as water-dispersed acrylic resin, water-dispersed polyester resin, and water-dispersed polystyrene resin; acrylic resin emulsion, polyvinyl acetate emulsion, SBR
(Styrene / butadiene / rubber) An emulsion such as an emulsion, or a copolymer, a mixture thereof, or an aqueous solution such as a cation-modified one, which is appropriately selected.
More than one species can be combined. Further, the gelatin may be selected from lime-processed gelatin, acid-processed gelatin, and so-called demineralized gelatin having a reduced content of calcium and the like according to various purposes, and it is also preferable to use them in combination.

The interfacial tension of the polymer used is preferably 32 mN / m or less, depending on the coating method, and is preferably 32 mN / m or more when the toner particles are fixed. The film forming temperature of the polymer used is preferably 100 ° C. or higher for storage before printing, and is preferably 100 ° C. or lower for fixing toner particles.

The image receiving layer may be composed of two or more layers.
The thickness of the image receiving layer is 0.1 to 500 μm in total, and
A range of 00 μm is preferred. The thickness of the image receiving layer is 0.1 μm
It is not preferable that the ratio is less than the range, since the toner cannot be retained after the fixing and the image is likely to have a defect. If the thickness of the image receiving layer exceeds 500 μm, the texture as a photograph is inferior, which is not preferable.

The image receiving layer of the present invention can be provided on the front polyolefin layer of the front and back polyolefin layers of the support, and further on the back polyolefin layer. When provided on the back polyolefin layer, it is preferable because it has the performance as a heat-resistant layer and can be printed on both sides. The composition and configuration of the image receiving layers on the front and back surfaces may be the same or different.

The support used in the present invention has a basic structure comprising base paper, a surface polyolefin layer provided on the front surface of the base paper, and a polyolefin layer provided on the back surface. The basis weight of the base paper is preferably in the range of 50 to 250 g / m ² , especially 100 to 180 g / m ² ,
Its thickness is 50-250 μm, especially 100-180 μm
Is preferably within the range.

Since the polyolefin-coated paper used in the present invention is required to have good smoothness, it is preferable to use a base paper having a center line average roughness of 1.5 μm or less. The fiber length distribution as disclosed in Japanese Patent Application Laid-Open Publication No. H10 (1995) (i.e., the sum of the residual content of the 24 mesh screen and the residual content of the 42 mesh screen is 20% by weight or more and 45% by weight or less, and the residual content of the 24 mesh screen is 5% by weight. % Pulp fibers).

The support of the electrophotographic image-receiving sheet of the present invention is obtained by coating both sides of the base paper with a polyolefin resin. The coating layer of the polyolefin resin may have a single-layer structure or a laminated structure composed of two or more layers.

The back polyolefin layer is usually formed using high density polyethylene or a blend of high density polyethylene and low density polyethylene. Although there is no particular limitation on the molecular weight of the polyethylene, the melt index is between 1.0 to 40 g / 10 minutes for both high-density polyethylene and low-density polyethylene,
Those having extrusion suitability are desirable.

The thickness of the front polyolefin layer and the back polyolefin layer is about 5 to 100 μm, preferably about 15 to 50 μm. The surface polyolefin layer and the back polyolefin layer may be the same or different in components, physical properties, thickness and constitution.

In the present invention, before the polyolefin resin is coated on both surfaces of the base paper, the base paper is subjected to an activation treatment such as a corona discharge treatment, a flame treatment, a glow discharge treatment, or a plasma treatment. Is preferred.

When an electrophotographic image-receiving sheet is produced using the support of the present invention, the surface of the coating layer on the side (surface) on which the image-receiving layer is formed may have a glossy surface, The fine surface, matte surface or silk surface described in JP-A-55-26507 may be formed, and the surface of the coating layer on the side opposite to the side on which the conductive layer is formed (the back side) may be provided.
A matte surface may be imprinted. Further, these surfaces after molding can be subjected to activation treatment such as corona discharge treatment and flame treatment.
An underlining process as described in Japanese Patent Application Laid-Open No. 1-846443 can also be performed. Further, the coating layer of the polyolefin resin, within a range that does not impair the object of the present invention,
Various additives appropriately selected can be added.

In the present invention, organic and / or inorganic fine particles (hereinafter abbreviated as a matting agent) may be added to the constituent layer. The image receiving sheet for electrophotography of the present invention preferably uses a matting agent. The matting agent used preferably contains a matting agent having a diameter of 3 μm or more and 30 μm or less.
More preferably, the particle size of the matting agent is from 10 μm to 30 μm.

The average particle size of the matting agent depends on the thickness of the heat-resistant layer.
0, more preferably 1 to 300, particularly preferably 1 to 1
00 is preferred. The matting agent may appear on the surface of the heat-resistant layer or may enter the inside. The application amount of the matting agent is 0.
001 g / m ^{2 to 20} g / m ² are preferable, and
Preferably ^{3g / m 2 ~10g / m 2} , in particular 0.005 g /
m ² ~5g / m ² is preferred.

The image receiving sheet for electrophotography of the present invention can contain a charge controlling agent in at least one layer for the purpose of controlling transfer and adhesion of toner. As the charge control agent, any of conventionally known antistatic agents can be used,
In addition to surfactants such as cationic surfactants, anionic surfactants, amphoteric surfactants, and nonionic surfactants, polymer electrolytes, conductive metal oxides, and the like can be used.
For example, cationic antistatic agents such as quaternary ammonium salts and polyamine derivatives; anionic antistatic agents such as cation-modified polymethyl methacrylate, cation-modified polystyrene, and alkyl phosphate; nonionic antistatic agents such as anionic polymers and fatty acid esters. Agents, but are not limited to these.

As the conductive metal oxide, ZnO, TiO 2,
Examples include SnO ₂ , Al ₂ O ₃ In ₂ O ₃ , SiO ₂ , MgO, BaO and MoO ₃ . These may be used alone or a composite oxide of these may be used. Further, the metal oxide may further contain a different element, for example, ZnO
For Al, In, etc., TiO 2 for Nb, Ta, etc., and SnO ₂ for Sb, Nb, halogen element, etc. (doping).

The toner image receiving layer is 1 × 10 ⁶ to 1 × 10 ¹⁵
(At 25 ° C., 65% RH). If it is less than 1 × 10 ⁶ Ω, the amount of toner when the toner is transferred to the image receiving layer is insufficient, and the density of the obtained toner image is low.
If it exceeds ¹⁵ Ω, an excessive charge is generated at the time of transfer, the toner is not sufficiently transferred, and the image density becomes low. It is not preferable because dust is easily attached due to static electricity during the handling of the electrophotographic image receiving sheet, and misfeeding, double feeding, discharge marks, toner transfer dropping and the like are liable to occur during copying. Further, it is not always necessary to adjust the charge of the heat-resistant layer containing the water-soluble polymer. In the present invention, a photographic additive is used for the base paper, the front polyolefin layer, the back polyolefin layer, the protective layer, the image receiving layer, the cushion layer, the porous layer, the heat-resistant layer, the adhesive layer, etc. constituting the electrophotographic image-receiving sheet. Can be. For example, as a photographic additive,
Research Disclosure Magazine (hereinafter abbreviated as RD) N
o. 17643 (December 1978), No. 1871
No. 6 (November 1979) and No. 307105 (1
Nov. 989), and the relevant locations are summarized below.

Type of additive RD17643 RD18716 RD307105 Brightener 24 page 648 page right column page 868 2. Stabilizer page 24-25 page 649 right column page 868-870 3. 3. Light absorber page 25-26 page 649 right column page 873 UV absorber 4. Dye image stabilizer page 25, page 650, right column, page 872 5. Hardening agent page 26 page 651 left column pages 874 to 875 Binder page 26 page 651 left column pages 873 to 874 7. 7. Plasticizers and lubricants Page 27 Page 650 Right column Page 876 8. Coating aid page 26-page 27 page 650 right column page 875-876 Surfactant 10. Antistatic agent, page 27, page 650, right column, pages 876 to 877 Matting agent 878-879

As the toner used in the color electrophotographic method, known toners can be used, and yellow, magenta,
It is preferable to form a color image with three or four colors of cyan or black. Further, two or more toners having different color densities may be used. Also, a transparent or white toner may be used. Further, a toner having UV absorption or a toner containing various additives mentioned as additives for the image receiving layer may be used. For example, a toner containing an anti-fading agent can form a toner image having excellent image storability. Two or more kinds of toners may react and exhibit a function. A toner having a higher softening point than other toners may be used in combination and used as a so-called matting agent. Further, the toner may have a different contact angle with the image receiving layer in a molten state, and the spread of each toner at the time of fixing may be controlled to change the effective density to form a part of the gradation. . The present invention does not limit the type and method of the toner.

[0029]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited to these examples. In the following Examples and Comparative Examples, “%” and “parts” represent “% by weight” and “parts by weight”, respectively.

Examples 1 to 18 and Comparative Examples 1 to 2 Fine paper produced by internally adding water-dispersible anatase-type titanium dioxide to a content of 1.0 g / m ² (basis weight of pulp structure: 150 g) / M ² ) as a base paper and a high density polyethylene (MI = 10 g / 10 min, density 0.950 g / cm ³ ) containing 3.0 g / m ² of rutile titanium dioxide on the back surface.
Was extruded by an extrusion coating method (310 ° C.) to form a backside polyethylene layer having a thickness of 0.30 mm.

Next, a high-density polyethylene (MI = 8 g / 10 min, density 0.950 g /
cm ³ ) and a low density polyethylene (MI = 7 g / 10 min, density 0.923 g / cm ³ ) in a 1/1 (weight ratio) blend (containing 3.0 g / m ^{2 of} anatase type titanium dioxide)
Is similarly extruded by an extrusion coating method, and has a thickness of 0.1 mm.
A 030 mm surface polyethylene layer was formed. After the above-mentioned backside polyethylene layer was subjected to corona discharge treatment, a heat-resistant layer composition shown in Table 1 was applied and dried to provide a heat-resistant layer.

[0032]

[Table 1]

[0033]

[Table 2]

The above-mentioned surface polyethylene layer is subjected to a corona discharge treatment, and a composition for an undercoat layer described below is applied by a wire coater so as to have a thickness of 0.1 μm after drying, and dried. After providing, the composition for the image receiving layer described below, coated with a wire coater, dried, and Examples 1 to 18,
Comparative Examples 1 and 2 were prepared.

<Composition for undercoat layer> Gelatin 5 g Water 95 g <Image-receiving layer compositions of Examples 1 to 18, thickness after drying was set to 5 μm> Polyester resin (manufactured by ATR-2009 Kao) 100 g Methyl ethyl ketone (hereinafter referred to as “methyl ethyl ketone”) 800 g <Image-receiving layer composition of Comparative Example 1, 0.4 g / m ² after drying> Carboxylated styrene-butadiene copolymer 100 g MEK 800 g <Image-receiving layer composition of Comparative Example 2, dried. 9 g / m ² > acrylate-vinyl acetate-vinyl chloride copolymer 45.4 g aluminum-modified silico (colloidal) 27.3 g pyrogenic silica 27.3 g MEK 800.0 g

An electrophotographic image-receiving sheet prepared on a Fuji Xerox color laser printer (color laser window 3310) was cut into A4 sheets, set, and an image from a computer was printed. ≪Evaluation≫ Conveyability: 50 sheets printed, no problem at all ○: 1 to 5 sheets stopped at fixing section △, 6
Table 2
It was shown to. In addition, the texture and glossiness of the image were similar to those of the photograph, and the roughness and lack were similar. Further, in Examples 13 to 18, after printing once, it was possible to print again on the back surface.

A commercially available color laser printer,
Specifically, LP-8000C manufactured by Seiko Epson, COLOR PAGEPRESTO N4-ST manufactured by Casio Electronics, COLOR L manufactured by Canon
ASERSHOT LBP-2030, manufactured by QMS Japan
When printed with magicolor 2, Color LaserBit KL-2010 made by Konica, JX-8200 made by Sharp, BEAMSTAR-RW made by Hitachi, and Color Page Pro PS made by Minolta, the same results as shown in Tables 1 and 2 were obtained. Was done.

[0038]

According to the electrophotographic image receiving sheet having a heat-resistant layer or an image receiving layer provided on the back of a support having a polyolefin layer on the front and back of the base paper of the present invention, the texture and gloss are similar to those of a photograph, and the paper is conveyed. It is possible to provide an electrophotographic image-receiving sheet which has printer suitability without causing a failure and can be used for photographic applications without image quality deterioration due to roughness or lack of an image.

Claims (7)

[Claims] 1. A base paper, at least one polyolefin layer and at least one toner image receiving layer are sequentially provided on the surface of the base paper, and at least one heat-resistant layer made of a polyolefin layer and a hydrophilic resin are sequentially provided on the back surface of the base paper. An image receiving sheet for electrophotography, comprising: 2. The electrophotographic image receiving sheet according to claim 1, wherein the toner image receiving layer contains a polyester resin. 3. The method according to claim 1, wherein the heat-resistant layer is formed of polyvinyl alcohol and / or
Or containing gelatin.
The image receiving sheet for electrophotography according to the above. 4. The electrophotographic image-receiving sheet according to claim 1, wherein the heat-resistant layer contains organic and / or inorganic fine particles. 5. A base paper, a front polyolefin layer provided on the front surface of the base paper, a back polyolefin layer provided on the back surface, and an image receiving layer for a toner image provided on both surfaces of the front and back polyolefin layers. Image receiving sheet for electrophotography. 6. The electrophotographic image-receiving sheet according to claim 5, wherein the toner image-receiving layer contains a polyester resin. 7. An image forming method for forming a toner image by color toner on an image receiving sheet, wherein the image receiving sheet is the sheet according to claim 2 or 6.