JPH1152605A - Recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording sheet of an electrophotographic method in which fusion to a fixing roller at the time of fixing, or cohesive failure of an acceptor layer itself to damage transparency can be eliminated to provide high image quality in an oilless fixing system. SOLUTION: An acceptor layer and an antistatic layer are formed in this order on at least one surface of a base film, and a releasing component same as the releasing component used on a fixing roller is added to the acceptor layer and/or the antistatic layer, between the acceptor layer and the antistatic layer, or in an outermost layer. Releasing effect is thus improved by existence of the same releasing component as the releasing component used on the fixing roller on the recording sheet side, and existence of the same releasing component on the fixing roller surface and the recording sheet surface as contact surfaces to each other at the time of fixing, so fusion of the recording sheet to the fixing roller, or cohesive failure of the acceptor layer itself can be eliminated, thereby recording of high image quality in an electrophotographic method can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic recording sheet, and more particularly, to a method in which oil is not used at the time of heating and pressure fixing to prevent deterioration of image quality and high transparency. The present invention relates to a recording sheet that can be used as an OHP film.

[0002]

2. Description of the Related Art Recently, a method of forming a full-color image has been put to practical use by using an electrophotographic system and mixing three colors of yellow, magenta, and cyan, or a mixture of four colors of toner obtained by adding black to the above three colors. I have. The recording sheet used in the electrophotographic method generally has a configuration in which a receiving layer is formed on a base material in order to reliably record and hold recording information such as characters and images. This recording sheet is used for an OHP (overhead projector) as an information transmission means used in, for example, lectures, schools, companies, other briefings and exhibitions.

[0003] In the electrophotographic system, when fixing toner on a recording sheet, a method is generally used in which the toner is transferred to the recording sheet and then heated and pressed against a roller. Further, in order to prevent the offset of the toner itself, a mechanism is generally employed in which silicone oil is constantly applied to the fixing roller to lower the affinity between the toner and the roller. In addition, when recording a color image on a plastic base material, especially OH
In the case of the P application, a receiving layer having a high affinity for the toner is generally applied to the surface of the recording sheet in order to improve the transparency of the image. At this time, the offset of the receiving layer itself applied is also prevented by the effect of the silicone oil.

[0004]

On the other hand, in recent years, as the demand for high image quality of the recording sheet has increased, the recording sheet itself has been adhered with silicone oil and is sticky, too shiny, or has deteriorated image quality due to oil. There is a problem that occurs. In recent years, the demand for an oil-less fixing system has been increasing due to environmental problems and the like.However, in the case of a recording sheet provided with a current receiving layer, the recording sheet may be fused to a fixing roller at the time of fixing, or the recording sheet may be received. There is a problem that the layer itself undergoes cohesive failure and the transparency is impaired.

Accordingly, an object of the present invention is to solve the above-mentioned problems by preventing the recording sheet itself from adhering silicone oil to the recording sheet and preventing the recording sheet from sticking, being too shiny, and causing deterioration in image quality due to the oil. In addition, even in an oilless fixing system, an electrophotographic recording method that can obtain high image quality without fusing to a fixing roller at the time of fixing, or causing a cohesive failure of a receiving layer itself and losing transparency. To provide a seat.

[0006]

Means for Solving the Problems To achieve the above object, the present invention provides at least one surface of a base film,
In a recording sheet having a receiving layer for forming a toner image and an antistatic layer formed in this order, in the receiving layer and / or in the antistatic layer, or between the receiving layer and the antistatic layer, or in the outermost layer, It is characterized in that the same release component as the release component used in the fixing roller is added. Further, it is preferable that the release component comprises a Si group. Further, it is preferable that the release component comprises an F group. Further, the substrate film is characterized in that the parallel line transmittance is 70% or more.

The operation of the present invention is as follows. The recording sheet of the present invention has a receiving layer for forming a toner image and an antistatic layer formed in this order on at least one surface of the base film, and is formed in the receiving layer and / or in the antistatic layer, or The same release component as the release component used for the material of the roller surface of the fixing roller is added between the receiving layer and the antistatic layer or as the outermost layer. Therefore, in electrophotographic recording in which oil is not used at the copying machine or printer side during heat and pressure fixing, the recording sheet side has the same release component as the release component used for the fixing roller. Therefore, the same release component exists on the surface of the fixing roller and the surface of the recording sheet, which are the contact surfaces at the time of fixing, and the release effect is further improved.
A high quality electrophotographic recording can be obtained without the recording sheet being fused to the fixing roller or the receiving layer itself being cohesively broken. The releasing component contained in the receiving layer and / or the antistatic layer of the recording sheet is the same as the component used for the material of the surface of the fixing roller, and is the contact surface between the fixing rollers. No chemical reaction or physical damage occurs between the roller surface and the recording sheet surface.

[0008]

Next, an embodiment of the present invention will be described. The recording sheet of the present invention has a receiving layer for forming a toner image and an antistatic layer formed in this order on at least one surface of the base film, and is formed in the receiving layer and / or in the antistatic layer, or The same release component as that used in the fixing roller is added between the receiving layer and the antistatic layer or in the outermost layer.

(Base Film) As the base film used in the recording sheet of the present invention, the recording sheet is, for example, O
For use in observing a recorded image with transmitted light using an HP film or the like, a film formed of a thermoplastic resin having transparency, heat resistance, dimensional stability, and rigidity is preferable. Specifically, a polyethylene terephthalate resin, a polycarbonate resin, an acrylic resin, a polyvinyl chloride resin, a polypropylene resin, a polystyrene resin, a polyethylene resin, a cellulose diacetate resin, a cellulose triacetate resin, etc., a thickness of about 10 to 250 μm, preferably A film or sheet having a thickness of about 50 to 180 μm is exemplified. Among them, a polyethylene terephthalate resin, a polyvinyl chloride resin, a polypropylene resin, and a cellulose triacetate resin are more preferable in view of the above performance.

When a recording sheet is used for observing a recorded image with transmitted light using an OHP film or the like, the base film preferably has a parallel line transmittance of 70% or more. If the parallel line transmittance of the base film is less than 70%, it is not preferable to provide a layer such as a receiving layer on the base film, because the transparency of the recording sheet is reduced. For the purpose of improving the adhesion to the layer formed on the substrate film, the surface of the substrate film may be subjected to a known easy adhesion treatment such as a primer treatment or a corona discharge treatment.

(Receiving Layer) The receiving layer provided on at least one surface of the base material has a toner fixing property, and particularly for a full color electrophotographic OHP application, a resin excellent in wettability of a color toner is preferable. Examples of the resin forming the receiving layer include polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyacrylate, vinyl resins such as polystyrene, and polyethylene. Polyester resins such as terephthalate and polybutylene terephthalate, polyamide resins, copolymers of olefins such as ethylene and propylene with other vinyl monomers, ionomers, cellulose resins such as ethyl cellulose and cellulose acetate, polycarbonate resins, phenoxy resins, etc. And a vinyl resin or a polyester resin is particularly preferably used. The above resins may be used alone or in a mixture. However, when transparency is required for OHP applications, it is necessary to select and use resins having good compatibility.

In the recording sheet of the present invention, the same release components as those used in the above resin and the fixing roller can be added to the receiving layer. The release component used in the fixing roller is a release component used on the surface of the fixing roller on the printer side.For example, the release component is composed of a Si group, and the main chain is a siloxane bond. And a silicone rubber having an organic substituent such as a methyl group, a phenyl group, or a vinyl group in the side chain, or a rubber having a releasing component consisting of an F group. Fluorine rubber obtained by polymerization is exemplified. The fluororubber is, specifically, a copolymer of ethylene trifluoride chloride and vinylidene fluoride (Ke, manufactured by 3M)
1-F elastomer), a copolymer of vinylidene fluoride and propylene hexafluoride (Viton manufactured by DuPont, 3M Florel), and the like. The release components used in these fixing rollers all have a heat resistance of about 150 ° C. or higher.

[0013] The receiving layer of the recording sheet of the present invention comprises, as main components, a resin forming the receiving layer and the same release component as the release component used for the fixing roller. The content of the same release component is preferably in the range of 0.01% by weight to 50% by weight based on the resin for forming the receiving layer. If the content is too large, the transparency may be reduced. In particular, when transparency is required, it is necessary to adjust the addition amount so as to suppress the haze to 10 or less. On the other hand, if the content is too small, the desired effect of improving the offset prevention performance cannot be obtained.

In addition to the release component used in the fixing roller in the receiving layer, a release agent having a releasing effect with respect to the fixing roll, for example, a silicone compound, silicone oil, silicone resin, fluorine Resin, fluorine compound, various waxes, inorganic and / or organic filler,
Surfactants, metal soaps, and the like can be added as long as the effects of the present invention are not impaired. The receiving layer is formed by coating the above resin component, the same release component as the release component used in the fixing roller, and a coating liquid having various additives as necessary, such as gravure printing and silk screen printing. It is formed by a known printing means or a known coating means such as a gravure coat, and has a thickness of about 0.5 to 10 μm when dried.

(Antistatic Layer) The recording sheet of the present invention has a structure in which a receiving layer and an antistatic layer are formed in this order on one surface of a base film. The antistatic layer can be provided not only on the receiving layer but also on the other surface of the base film. The antistatic layer is formed mainly of a binder resin and an antistatic agent. In the present invention, the same release component as the release component used in the fixing roller can be added to the antistatic layer. However, if the antistatic agent is a resin and the adhesion to the layer in contact with the antistatic layer is good, the antistatic layer may be formed without a binder. As the above binder resin, for example,
Polyester resin, polyurethane resin, polyacrylic resin, polyvinyl formal resin, epoxy resin, polyvinyl butyral resin, polyamide resin,
Polyether resin, polystyrene resin, styrene
Acrylic copolymer resins and the like can be mentioned.

As the material used as the antistatic agent, any of conventionally known cations, anions, zwitterions and nonionics can be used. For example, quaternary ammonium salts, cationic antistatic agents such as polyamine derivatives, anionic antistatic agents such as alkyl phosphates,
Nonionic antistatic agents such as fatty acid esters are exemplified. Further, as a resin type antistatic agent, those obtained by grafting the above antistatic agent to a resin such as acrylic, π
A conductive polymer material having an electron conjugated structure can also be used. Conductive polymer materials include sulfonated polyaniline, chemically doped polyacetylene, polyparaphenylenevinylene, polyparaphenylene sulfide, chemically polymerized and doped polypyrrole, polythiophene, polyaniline, and heat-treated phenolic resin produced by heat treatment. , Heat treatment of polyamide, heat treatment of perylene anhydride, and the like. Furthermore, SnO
₂ , ZnO, In ₂ O ₃ , and Sb-doped SnO ₂ .

In the recording sheet of the present invention, the same release component as the release component used for the fixing roller can be added to the antistatic layer. The release component used in the fixing roller is the same as the release component added to the receiving layer, and a description thereof will be omitted. Further, in addition to the release component used in the fixing roller in the antistatic layer, a release agent having a release effect with the fixing roll, for example, a silicone compound, a silicone oil, a silicone resin, a fluorine resin, Fluorine compounds, various waxes,
Inorganic and / or organic fillers, surfactants, metal soaps and the like can be added as long as the effects of the present invention are not impaired.

The antistatic layer of the present invention comprises a binder component, an antistatic agent, the same release component as the release component used for the fixing roller and, if necessary, other additives dispersed in a solvent. It can be formed by a dissolved coating liquid. As a forming method, the above-mentioned coating solution is coated on the base film and / or on the receiving layer by a known printing means such as gravure printing, silk screen printing, or a known coating means such as gravure coating. Apply to The coating amount of the antistatic layer is about 0.5 as a solid content of the coating solution.
When the coating amount is less than the above range, the releasability and the antistatic performance are insufficient, and on the other hand, the coating amount is in the range of 0.1 to 1.0 μm, preferably 0.1 to 0.5 μm. If the amount is larger than the above range, the above performance is not necessarily improved in proportion to the thickness, so that not only is it economically disadvantageous, but also the density of an electrophotographic image is undesirably reduced.

The composition of the coating solution for the antistatic layer is such that the binder resin is about 0.5 to 10% by weight, preferably 0.7 to 10% by weight.
5 to 2% by weight, antistatic agent (solid content) is about 0.01 to 3
% By weight, preferably 0.01 to 1% by weight, the same release component as the release component used for the fixing roller (solid content)
Is desirably a composition consisting of about 0.5 to 5.0% by weight, preferably 1 to 2% by weight, and the balance of the solvent.

(Between the receiving layer and the antistatic layer or the outermost layer) In the recording sheet of the present invention, a receiving layer for forming a toner image and an antistatic layer are formed in this order on at least one surface of the base film. Then, the same release component as that used in the fixing roller is added to the receiving layer and / or the antistatic layer, between the receiving layer and the antistatic layer, or to the outermost layer. ing. Therefore, the recording sheet of the present invention has the above-described receiving layer or antistatic layer, or the receiving layer and the antistatic layer, as a layer to which the same releasing component as that used in the fixing roller is added. An intermediate layer between the layers, or an outermost layer (in the configuration of the base film / receiving layer / antistatic layer / outermost layer, the outermost layer of the recording sheet) may be mentioned. Here, since the receiving layer and the antistatic layer have already been described above, they are used for the intermediate layer between the receiving layer and the antistatic layer, or the outermost fixing roller, excluding the receiving layer and the antistatic layer. The layer to which the same release component as the release component is added will be described.

The intermediate layer or the outermost layer between the receiving layer and the antistatic layer is formed mainly of the same release component as the release component used for the binder resin and the fixing roller, and functions as a release layer. I do. As the binder resin,
For example, polyester resin, polyurethane resin, polyacrylic resin, polyvinyl formal resin, epoxy resin, polyvinyl butyral resin, polyamide resin, polyether resin, polystyrene resin, styrene-acryl copolymer resin, etc. No.

The same release components as those used in the fixing roller are the same as the release components added to the receiving layer and the antistatic layer, and the description thereof is omitted. . Further, in addition to the release component used in the fixing roller, a release agent having a release effect with a fixing roll, for example, a silicone compound, in the intermediate layer between the receiving layer and the antistatic layer, or in the outermost layer , A silicone oil, a silicone resin, a fluorine resin, a fluorine compound, various waxes, an inorganic and / or organic filler, a surfactant, a metal soap and the like can be added as long as the effects of the present invention are not hindered.

The intermediate layer or the outermost layer between the receptor layer and the antistatic layer of the present invention has the same release component as the above-mentioned binder resin and the release component used for the fixing roller, and if necessary, other components. Can be formed by a coating liquid in which the above additive is dispersed or dissolved in a solvent. As a forming method, the above-mentioned coating liquid is coated on the receiving layer or the antistatic layer by a known printing means such as gravure printing, silk screen printing, or a known coating means such as gravure coating. . The coating amount of the intermediate layer or the outermost layer between the receiving layer and the antistatic layer is about 0.0
When the coating amount is less than the above range, the releasability from the fixing roller is insufficient, and on the other hand, the coating amount is If the amount is larger than the above range, the above performance is not necessarily improved in proportion to the thickness, so that not only is it economically disadvantageous, but also the density of an electrophotographic image is undesirably reduced.

In the recording sheet of the present invention, the surface resistance value is 1
It is preferable that the surface resistance is in the range of 0 ⁷ to 10 ¹³ Ω / sq. When the surface resistance is in this range, the toner fixing property is good, the image quality is excellent, and the transport suitability in an electrophotographic copying machine and a printer is also good. . In the present invention, the surface resistance of the front surface and the back surface of the recording sheet, that is, the sheet resistance, the receiving layer,
By appropriately adjusting the conductivity of the receiving layer and the antistatic layer, depending on the thickness of each layer of the coating layer and the base film containing the antistatic layer, the ratio of the resin mixed with the antistatic agent in the antistatic layer, and the like. , The desired sheet resistance can be controlled.
For example, if the thickness of the antistatic layer is increased, the sheet resistance decreases. If the surface resistance of the recording sheet is lower than 10 ⁷ Ω / sq, image defects (image loss) tend to occur, and conversely 1 × 10
^If it exceeds ¹³ Ω / sq, poor conveyance tends to occur in electrophotographic copying machines and printers due to image defects (insufficient density), generation of static electricity and insufficient lubrication.

[0025]

Next, the present invention will be described in detail with reference to examples. In the following description, parts or% are based on weight unless otherwise specified. Example 1 A receiving layer was formed on one surface of a base film shown below such that a receiving layer coating solution 1 having the following composition had a thickness of 3.0 μm when dried with a bar coater. On the layer, a release layer coating liquid 1 having the following composition was applied in a dry thickness of 1.0 μm to form a release layer. Further, on the release layer, the antistatic layer coating liquid 1 having the following composition is dried so that the surface electric resistance when dried becomes 1.0 × 10 ¹⁰ Ω / sq (temperature 23 ° C., humidity 50% RH). To form an antistatic layer to obtain a recording sheet of Example 1 of the present invention. Base film 75 μm thick polyethylene terephthalate film (Lumirror T-60, manufactured by Toray) Parallel line transmittance 92%

Receptive layer coating liquid 1 Polyester resin (HP320, manufactured by Nippon Synthetic Chemical Co., Ltd.) 30 parts (glass transition temperature 62 ° C., softening point 95 ° C.) methyl ethyl ketone 35 parts toluene 35 parts

[0027]Release layer coating liquid 1 Polyester resin (HP301, manufactured by Nippon Synthetic Chemical Co., Ltd.) 10 parts (glass transition temperature: 62 ° C., softening point: 105 ° C.) Fluorine release agent (FC430, manufactured by Mitsui Fluorochemicals) 0.5 part Methyl ethyl ketone 35 parts Toluene 35 Department Antistatic layer coating liquid 1 Quaternary ammonium-based antistatic agent (manufactured by Matsumoto Yushi Co., Ltd., TB-34) 0.1 part IPA 200 parts

Example 2 A receiving layer was formed on one surface of the above-mentioned base film so that the receiving layer coating liquid 2 having the following composition had a thickness of 3.0 μm when dried with a bar coater. ,
The antistatic layer coating solution 1 having the above composition was applied on the receiving layer so that the thickness when dried was 0.5 μm, to prepare a recording sheet of Example 2 of the present invention. Receptive layer coating liquid 2 Polyester resin (HP320, manufactured by Nippon Synthetic Chemical Co., Ltd.) 17 parts (Glass transition temperature 62 ° C., softening point 95 ° C.) Silicone oil (KF54, manufactured by Shin-Etsu Chemical Co., Ltd.) 3 parts Methyl ethyl ketone 40 Parts Toluene 40 parts

(Example 3) A receiving layer was formed on one surface of the base film so that the receiving layer coating liquid 1 having the above composition had a thickness of 3.0 μm when dried with a bar coater. ,
The antistatic layer coating liquid 3 having the following composition was dried on the receiving layer to a surface electric resistance of 1.0 × 10 ¹⁰ Ω / sq (temperature 23
C. and a humidity of 50% RH) to form an antistatic layer, thereby obtaining a recording sheet of Example 3 of the present invention. Antistatic layer coating liquid 3 polyester resin emulsion 30 parts (Nippon Synthetic Chemical Co., Ltd., WR-961, solid content 30%) Cationic surfactant (Sanyo Chemical Co., Ltd., Sunstat 2012A) 1 part Silicone Modified acrylic resin emulsion 9 parts (Toa Gosei Chemical Co., Ltd., US-450, solid content 20%) IPA 40 parts Water 20 parts

(Comparative Example 1) The receiving layer coating liquid 2 of Example 2 was used.
The antistatic coating of Example 2 was changed to the receiving layer coating liquid 4 having the following composition.
After changing the stop coating liquid 2 to the antistatic coating liquid 4 having the following composition
Other than that, the recording sheet of Comparative Example 1 was prepared in the same manner as in Example 2.
did.Receptive layer coating liquid 4 Polyester resin (HP301, manufactured by Nippon Synthetic Chemical Co., Ltd.) 30 parts (glass transition temperature 62 ° C., softening point 105 ° C.) methyl ethyl ketone 35 parts toluene 35 parts Antistatic layer coating liquid 1 Quaternary ammonium-based antistatic agent (manufactured by Matsumoto Yushi Co., Ltd., TB-34) 0.1 part IPA 200 parts

Using the recording sheets of the above-mentioned Examples and Comparative Examples, evaluation of fixing suitability and image quality was performed by the following methods. (Evaluation method) Fixing suitability Using a self-made full-color LBP (oil-less fixing system using a laser beam printer), changing the material of the rubber on the surface of the fixing roller, and performing image recording on the recording sheets of Examples and Comparative Examples. It was examined whether the recording sheet was fused to the fixing roller during fixing. The criteria are as follows. ：: The receiving layer of the recording sheet does not offset after fixing. Δ: Part of the receiving layer of the recording sheet is offset after fixing. X: The receiving layer of the recording sheet is offset after fixing.

Image Quality Using a self-made full-color LBP (oil-less fixing system using a laser beam printer), the color chart is copied on the recording sheet of each of the examples and comparative examples, and the obtained image is sent to an OHP projector to obtain an image. The quality was evaluated.
The criteria are as follows. ：: The transmitted image is clear. Δ: There are some unclear spots in the transmission image. X: There is an unclear portion in the transmission image.

(Evaluation Results) Table 1 shows the evaluation results of the examples and comparative examples.

[Table 1]

[0034]

According to the recording sheet of the present invention, a receiving layer for forming a toner image and an antistatic layer are formed in this order on at least one surface of the base film.
Alternatively, the same release component as that used for the fixing roller is added to the antistatic layer, or between the receptor layer and the antistatic layer, or to the outermost layer. Therefore, even in an oilless fixing system, since the recording sheet has the same release component as the release component used for the fixing roller, the contact surfaces at the time of fixing are further fixed. The same release component exists on the roller surface and the recording sheet surface, the release effect is further improved, the recording sheet does not fuse to the fixing roller, and the receiving layer itself does not undergo cohesive failure, High quality electrophotographic recording is obtained.

Claims (4)

[Claims] Claims: 1. At least one surface of a substrate film,
In a recording sheet having a receiving layer for forming a toner image and an antistatic layer formed in this order, in the receiving layer and / or in the antistatic layer, or between the receiving layer and the antistatic layer, or in the outermost layer, A recording sheet comprising the same release component as the release component used in the fixing roller. 2. The recording sheet according to claim 1, wherein said release component comprises a Si group. 3. The recording sheet according to claim 1, wherein said release component comprises an F group. 4. The substrate film having a parallel line transmittance of 7
The recording sheet according to any one of claims 1 to 3, wherein the recording sheet is 0% or more.