JP2000122332A - Image accepting sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the top end of an image accepting sheet good in catching a fixing roller and to avoid hindrance due to detection marks after an image is formed, by forming a layer on a part of the image accepting sheet in such a manner that the layer can be peeled after electrophotographic record is fixed by heating. SOLUTION: A layer is formed on a part of at least one surface of a base sheet to prepare an image accepting sheet, and the layer can be peeled after the electrophotographic record is fixed by heating. The essential component of the layer is preferably a resin. The layer preferably has <20% transmittance of light at 980 nm and preferably contributes as a mark for a sensor to detect the image accepting sheet. Further, the base sheet without the layer preferably has >=70% transmittance of light at 980 nm. After electrophotographic recording, the layer is peeled from the image accepting sheet so that no traces (such as marks) which are visually undesirable are produced even when the transmitting type image accepting sheet is used for projection with an OHP.

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, and more particularly to an electrophotographic image receiving sheet which has excellent transportability for entering and exiting a fixing roller and which does not obstruct detection marks after image formation.

[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 image receiving sheet used in the electrophotographic system generally has a configuration in which a receiving layer is formed on a base material in order to reliably record and hold recorded information such as characters and images. The image receiving 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 to an image receiving sheet, a method is generally used in which the toner is transferred to the image receiving sheet and then heated and pressed against a roller. Further, in order to prevent offset of the toner itself, a mechanism is generally adopted 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 P application, a receiving layer having a high affinity for the toner is generally applied to the surface of the image receiving sheet in order to improve image transparency. At this time, the offset of the receiving layer itself applied is also prevented by the effect of the silicone oil.

Further, in the electrophotographic system, in order to detect a paper jam or the front and back of paper, in the case of a color image, three colors of yellow, magenta, and cyan or four colors obtained by adding black to the above three colors are used. Detecting means for forming an image pattern in register on the same image receiving sheet is provided. In particular, in order to form an image on a transparent image receiving sheet, for example, optical detection means is used in which light from a light source is applied to the transparent image receiving sheet and the presence or absence of reflected light or transmitted light is detected by a photo sensor. I have. For example, it is common practice to provide a detection mark on an image receiving sheet with opaque ink or metallic luster ink. For example, in Japanese Patent Publication No. 2611011, a detection mark of a metal powder in the form of a rim is described on an end piece, but the detection mark remains on the image receiving sheet even after image formation, which is visually unfavorable. Also, JP-A-58-90647 and JP-T-Hei-6-50.
No. 60307 describes an electrophotographic image-receiving sheet in which a transparent opaque body is provided on a transparent film to perform optical detection.

[0005]

In the above-described full-color copying machine or printer using the electrophotographic method, as a method of feeding an image receiving sheet, there is a method of feeding the image receiving sheet from a cassette or a manual feed. Since the tip portion is edged by a roller and transported, the degree of biting becomes a problem. Further, in order to prevent the toner and the receiving layer of the image receiving sheet from being offset from the fixing roller, silicone oil is applied to the roller. However, the silicone oil affects the fixing roller (between a pair of upper and lower rollers). ) Also causes a problem that the image receiving sheet is difficult to enter. In the past, as shown in JP-A-57-38437, there has been proposed a method of making one side of an image receiving sheet thinner. However, as a result of studying this method and conducting experiments, it was found that even if one side of the image receiving sheet was thinned, the bite was not improved.

In the case of the optical detection means using the above-described detection marks, it is possible to detect a paper jam, the front and back of paper, and the registration of a color image on an image receiving sheet. In the case of using it, there is a problem that not only a necessary image but also a detection mark is conspicuous and obstructive. Japanese Unexamined Patent Application Publication No. 58-90647 and the like detect a peelable opaque body by sticking the opaque body to a transparent film via an adhesive, and it takes time to apply the adhesive. Therefore, an object of the present invention is to solve the above-mentioned problem, the bite of the fixing roller of an electrophotographic copying machine or a printer has a good bite with the front end portion of an image receiving sheet, and the transportability of entering and discharging the fixing roller is excellent. Another object of the present invention is to provide an image receiving sheet in which the detection mark does not interfere after image formation.

[0007]

In order to achieve the above object, the present invention provides an image receiving sheet having a layer provided on at least a part of at least one surface of a base sheet, wherein the layer is formed by heat fixing of electrophotographic recording. It is characterized in that it can be peeled off later.
The main component of the layer is preferably a resin. The layer has a light transmittance at 980 nm of 20.
% Is preferred. Further, it is preferable that the layer contributes as a sensor mark for detecting an image receiving sheet. Furthermore, it is preferable that the light transmittance at 980 nm of a portion where the above-mentioned layer is not provided on the base material sheet is 70% or more.

The operation of the present invention is as follows. In the image receiving sheet of the present invention, a layer is provided on at least a part of at least one surface of the base sheet so that the layer can be peeled off after heat fixing of electrophotographic recording. Therefore, the above-mentioned layer is 980
When the light transmittance in nm is less than 20%, or by using as a sensor mark for detecting an image receiving sheet, an electrophotographic recording is performed on the image receiving sheet, and after the recording, the layer is peeled off from the image receiving sheet. In a transmissive image receiving sheet, there is no object (mark or the like) that would be annoying even when projected by OHP. Also, some of the base sheet,
Since the above-described layer is provided, the fixing roller has good biting with the leading end portion of the image receiving sheet, and has excellent transportability of entering and discharging the fixing roller. Various methods of peeling are considered, but in order to utilize the high film forming property of the resin,
Easy peeling by hand. It is also conceivable to attach a nail to the machine and mechanically delete it.

[0009]

Next, an embodiment of the present invention will be described. The image receiving sheet of the present invention is characterized in that a layer is provided on at least a part of at least one surface of the base sheet, and the layer becomes peelable after heat fixing of electrophotographic recording.

(Base Sheet) As the base sheet used in the image receiving sheet of the present invention, an image receiving sheet such as OHP
For use in observing a recorded image with transmitted light using a film or the like, a film formed of a thermoplastic resin having transparency, heat resistance, dimensional stability, and rigidity is preferable. In particular,
10 thickness of polyethylene terephthalate resin, polycarbonate resin, acrylic resin, polyvinyl chloride resin, polypropylene resin, polystyrene resin, polyethylene resin, cellulose diacetate resin, cellulose triacetate resin, etc.
A film or sheet having a thickness of about 250 μm, preferably about 50 to 180 μm is mentioned. 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 an image receiving sheet is used for observing a recorded image with transmitted light using an OHP film or the like, the 980 nm
Is preferably 70% or more. If the light transmittance of the substrate sheet is less than 70%, it is not preferable to provide a layer such as a receptor layer on the substrate sheet, because the transparency of the image receiving sheet is reduced. For the purpose of improving the adhesion to the layer formed on the substrate sheet, the surface of the substrate sheet 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. The receiving layer is prepared by adding an additive as necessary to the resin as described above, and dissolving or dispersing it in an appropriate solvent to prepare a coating liquid, on a substrate sheet, a known method such as gravure printing or silk screen printing. Or a known coating means such as a gravure coat, and the thickness when dried is about 0.5 to 10 μm.

(Antistatic Layer) The image-receiving sheet of the present invention has a receiving layer on one surface of a base sheet, and an antistatic layer can be provided on the receiving layer. Incidentally, an antistatic layer may be provided on the other surface of the base sheet. The antistatic layer contains a component having a releasing effect. Therefore, the antistatic layer is formed mainly of a binder resin, a component having a releasing effect, and an antistatic agent. 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 binder resin, for example, polyester resin, polyurethane resin, polyacrylic resin,
Examples include a polyvinyl formal resin, an epoxy resin, a polyvinyl butyral resin, a polyamide resin, a polyether resin, a polystyrene resin, and a styrene-acryl copolymer resin.

The antistatic layer contains the binder resin and a component having a releasing effect. The component having a releasing effect is a component having a releasing effect without being fused to a roller when the toner is heated, pressed and fixed when an image is formed on an image receiving sheet. Examples of the component having a releasing effect include components having a Si group, such as a silicone compound, silicone oil, and silicone resin.
In particular, epoxy modification, vinyl modification, alkyl modification, amino modification, carboxyl modification, alcohol modification, fluorine modification, alkyl aralkyl polyether modification, epoxy
It is preferable that a modified silicone oil such as polyether-modified or polyether-modified is added to the antistatic layer and cured. The amount of the modified silicone oil to be added varies depending on the type thereof, but the amount of the modified silicone oil separated from the fixing roll is within the range of about 1 to 20 parts by weight based on 100 parts by weight of the resin solids of the antistatic layer. The minimum amount at which the mold performance is sufficiently exhibited is preferable. When a modified silicone oil having a reactive group capable of reacting with a curing agent such as an isocyanate compound, an amino compound and an organometallic compound is added to the modified silicone oil, the equivalent of the reactive group between the modified silicone oil and the curing agent is adjusted to 1 : 1 to 1:10.

Further, as the component comprising the F group, a fluorine resin obtained by polymerization of an olefin containing fluorine as represented by the trade name of Teflon, or a fluorine-containing polymer or copolymer obtained by processing a fluorine-containing polymer or copolymer into rubber. Rubber and a fluorine compound can be used as a component having a releasing effect.
Examples of the component having a releasing effect include wax, and examples thereof include microcrystalline wax, carnauba wax, and paraffin wax. Furthermore, Fischer-Tropsch wax, various low molecular weight polyethylenes, wood wax, beeswax, whale wax, Ibota wax, wool wax, shellac wax, candelilla wax, petrolactam,
Various waxes such as polyester wax, partially modified wax, fatty acid ester, fatty acid amide, polyethylene wax, sterol wax and the like can be mentioned.

A component having a releasing effect composed of an inorganic and / or organic filler can be used. Examples of the organic filler include a filler made of an organic resin such as a tetrafluoroethylene resin, a fluororesin such as an ethylene-tetrafluoroethylene copolymer, a polyethylene resin, a polystyrene resin, an acrylic resin, a polyamide resin, and a benzoguanamine resin. . On the other hand, as the inorganic filler, silica, colloidal silica, alumina, kaolin, clay,
Examples include calcium carbonate, talc, titanium dioxide, calcium carbonate, and the like. The average particle size of the filler to be contained is preferably in the range of 0.1 to 10 μm. If the average particle size is less than 0.1 μm, the desired effect cannot be sufficiently obtained.
This is not preferable because transparency when used for HP is reduced. In addition, a component having a releasing effect composed of a surfactant can be used. Examples of the surfactant include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, and a fluorine-based surfactant. In particular, it is preferable to use a liquid activator at room temperature, such as a phosphate ester-based surfactant.

Further, a component having a releasing effect made of metal soap can be used. Metal soaps are non-alkali metal long chain fatty acid salts, for example, zinc stearate, calcium stearate, magnesium stearate, aluminum stearate, strontium stearate, barium stearate, lithium stearate, lithium 12-hydroxystearate And zinc laurate, calcium laurate, barium laurate, lead benzoate, zinc para-tert-butylbenzoate, barium para-tert-butyl benzoate, sodium stearate, potassium stearate, sodium oleate and the like. Further, as phosphate ester metal salts, stearyl acid phosphate, magnesium stearyl acid phosphate, aluminum stearyl acid phosphate, calcium stearyl acid phosphate, zinc stearyl acid phosphate, barium stearyl acid phosphate, zinc behenyl acid phosphate Can be used.

The content of the above-mentioned components having various releasing effects is from 0.01% by weight to 5% by weight based on the resin for forming the antistatic layer.
A range of 0% by weight is preferred. 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.

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 .

The antistatic layer of the present invention is formed from the above-mentioned binder resin, a component having a releasing effect, an antistatic agent, and other additives as necessary. Water, methanol, ethanol,
A coating liquid is prepared by dissolving or dispersing the binder resin and a component having a releasing effect and an antistatic agent in a mixture with a water-soluble organic solvent such as isopropyl alcohol and normal propyl alcohol. An optional additive such as a surfactant for improving the wettability at the time of coating and an antifoaming agent for suppressing bubbles can be added to the coating liquid.

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, a component having a releasing effect (solid content) is about 0.5 to 5.0% by weight, preferably 1 to 2% by weight, and an antistatic agent (solid content) is about 0.01 to 3%. Preference is given to a composition comprising, by weight, preferably 0.01 to 1% by weight and the balance of the solvent. When only a component having an antistatic agent and a releasing effect is used without a binder resin, the mixture is appropriately diluted with a solvent and applied. The antistatic layer is formed by applying and drying the above-mentioned coating solution on the image receiving sheet by a conventional coating method such as a gravure coater, a roll coater, and a wire bar. 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 performance as the releasability and the antistatic property is insufficient. If the amount is more than the above range, the above-mentioned performance is not improved in proportion to the thickness thereof, so that not only is it economically disadvantageous but also the density of an electrophotographic image is undesirably reduced.

(Layer Releasable After Heat Fixing) The image receiving sheet of the present invention is provided with a layer releasable after heat fixing of electrophotographic recording on at least a part of at least one surface of the base sheet. It is preferable that the layer has a light transmittance at 980 nm of less than 20% so as to be easily detected by a sensor as a sensor mark for detecting an image receiving sheet. The layer that can be peeled off after heat fixing can be formed on either the image receiving surface side or the back surface side of the base sheet. The layer that can be peeled off after heating and fixing does not peel off when handling the image receiving sheet before electrophotographic recording,
Also, it does not come off during recording with an electrophotographic copying machine or printer. Then, after electrophotographic recording, that is, after heat fixing, the layer is peeled off with an adhesive tape,
It can be scraped off by rubbing with nails or coins.

The layer which becomes peelable after heat fixing can be composed of a coloring agent and a vehicle. For example, rubber-based natural resins (natural rubber, hydrochloride rubber, etc.), diene-based resins (polybutadiene rubber, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polyisoprene,
Acrylic resin such as polychloroprene), acrylic resin such as ethylene-acrylic acid copolymer and polymethyl methacrylate, vinyl resin, ionomer resin, etc. are used as vehicles (components for transferring and fixing pigments on a printing surface) and coloring. Various pigments and dyes can be used as the agent. In the present invention, since a layer that can be peeled off after heat fixing is preferably used as a sensor mark for detecting an image receiving sheet, a colorant having a high concealing property is often used. Specific examples include metallic fine powders, for example, fine powders of aluminum, brass, copper and the like, fine oxide powders of iron oxide, titanium oxide, cobalt oxide and the like, carbon, calcium carbonate and the like.

The content of the above colorant is about 30 to 80% by weight with respect to the solid content of the entire layer to achieve optical detection and releasability after heat fixing of electrophotographic recording. Can be. The formation of a layer that can be peeled off after heat fixing is
Add the above vehicle and colorant and various auxiliaries as needed, or dissolve or disperse in a suitable solvent,
The printing ink is adjusted and a known method, offset printing, letterpress printing, gravure printing,
The ink is applied and dried by a forming means such as a screen printing method. The coating amount of the layer that can be peeled off after heating and fixing is in the range of about 1 to 10 μm as a solid content of the coating liquid. If the coating amount is smaller than the above range, optical detection is difficult to be performed, while If the amount of work is more than the above range, it becomes difficult to peel off after heat-fixing the electrophotographic recording, or it is not preferable.

In the image receiving sheet of the present invention, a layer releasable after heat fixing of electrophotographic recording, and a receiving layer and an antistatic layer are provided on at least a part of one surface of the base sheet, if necessary. In the form of the final image receiving sheet, the surface resistance is preferably in the range of 10 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. When the surface resistance value of the image receiving sheet is lower than 10 ⁷ Ω / sq, image defects (image loss) tend to occur. Conversely, when the surface resistance value exceeds 1 × 10 ¹³ Ω / sq, image defects (insufficient density), static electricity generation and lubricity occur. Shortage tends to cause transport failure in electrophotographic copiers and printers.

[0027]

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) On one surface of a base sheet (A4 size) shown below, a receiving layer coating solution having the following composition was formed with a bar coater so that the thickness when dried was 3.0 μm. And on the receiving layer, a width of 1 mm on the short side of A4 size.
The layer coating liquid 1 which can be peeled off after heating and fixing the following composition in a linear shape of 5 mm × length 210 mm has a thickness of 2.
0 μm to form a peelable layer (detection mark), and an antistatic layer having the following composition having a dry thickness of 1 on the receiving layer including the peelable layer. .
The image receiving sheet was formed so as to have a thickness of 0 μm.

Polyethylene terephthalate film (Lumirror T-60, manufactured by Toray Co., Ltd.) having a base sheet thickness of 100 μm, and a light transmittance at 980 nm of 92%

Receptive layer coating liquid polyester resin 30 parts (polymer of terephthalic acid and propylene glycol-modified bisphenol A, glass transition temperature 60 ° C., softening point 100 ° C., solid content 30%) methyl ethyl ketone 40 parts toluene 30 parts silica ( Average particle size 5μm) 0.3 part

Peelable layer coating liquid Titanium monoxide (average particle size 300 nm) 20 parts Ethylene-acrylic acid emulsion (solid content 25%) 40 parts Water 40 parts

Antistatic layer coating liquid Quaternary ammonium antistatic agent (TB-34, manufactured by Matsumoto Yushi Co., Ltd.) 1 part Isopropyl alcohol 100 parts

(Example 2) The procedure of Example 1 was repeated, except that the layer capable of being peeled off after heating and fixing in Example 1 was changed from Coating Solution 1 to Coating Solution 2 below. An image receiving sheet of Example 2 was prepared. Peelable layer coating liquid 2 Carbon black 10 parts Ionomer resin emulsion (minimum film formation temperature 80 ° C, solid content 30%) 40 parts Isopropyl alcohol 30 parts Water 20 parts

(Comparative Example 1) As in Example 1, a receiving layer coating solution was formed on one surface of a substrate sheet so that the thickness when dried with a bar coater was 3.0 μm. Then, on the receiving layer, a width of 15 mm is set on the short side of A4 size.
× In a straight line of 210 mm length, a detection mark coating liquid having the following composition was applied at a dry thickness of 3.0 μm to form a detection mark, and further including the detection mark, on the receiving layer, The coating liquid for the antistatic layer used in Example 1 was formed so that the thickness when dried was 1.0 μm, and an image receiving sheet of Comparative Example 1 was produced.

Detection mark coating liquid Titanium oxide 20 parts Polyester resin (manufactured by Toyobo Co., Ltd., Byron 290) 20 parts Methyl ethyl ketone 30 parts Toluene 30 parts

Using the image receiving sheets of the above Examples and Comparative Examples, by the following method, the transportability near the fixing roller of the electrophotography, and the visual detection of the detection mark when the image was projected by the OHP after the electrophotographic image was formed. An assessment of disability was performed. (Evaluation Method) transportability Canon KK full-color copying machine Pixel CLC-2
Using No. 00, images were formed on the image receiving sheets of Examples and Comparative Examples, and the degree of biting between the fixing roller and the front end portion of the image receiving sheet, and the transportability of the image receiving sheet into and out of the fixing roller were examined. The criteria are as follows. ：: The bite between the fixing roller and the front end of the image receiving sheet is good, and the transportability is good. X: The bite between the fixing roller and the front end of the image receiving sheet is weak, and the transportability is poor.

Visual Obstruction of Detection Marks Images are formed on the image receiving sheets of Examples and Comparative Examples in the same manner as the image forming conditions when the above-described transportability is examined. When the work of sticking cellophane tape to the part and peeling it off was performed, the detection mark of Example 1 was completely peeled off,
The detection mark of Comparative Example 1 did not peel off at all. And
The obtained image was set on an OHP projector to visually check whether the detection mark visually interfered. The criteria are as follows. ：: No detection mark was observed, and no obstruction was observed. X: The detection mark is conspicuous and obtrusive.

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

[Table 1]

[0038]

The image receiving sheet of the present invention is provided with a layer on at least a part of at least one surface of the base sheet, and this layer can be peeled off after heat fixing of electrophotographic recording. Therefore, the layer is used as a sensor mark for detecting an image-receiving sheet by making the light transmittance at 980 nm less than 20% or the like, and electrophotographic recording is performed on the image-receiving sheet. By peeling off the sheet, the transmission type image receiving sheet does not have any objectionable marks (marks and the like) when projected on the OHP. In addition, the bite of the fixing roller with the tip of the image receiving sheet is good,
Excellent transportability for entering and discharging the fixing roller. Furthermore, the image receiving sheet of the present invention has a layer that can be peeled off after heating and fixing is formed as a single layer without providing an adhesive on the base sheet, so that the adhesive is applied. It can be created easily without any hassle.

Claims (5)

[Claims] 1. An image receiving sheet having a layer provided on at least a part of at least one surface of a base sheet, wherein said layer becomes peelable after heat fixing of electrophotographic recording. 2. The image receiving sheet according to claim 1, wherein a main component of the layer is a resin. 3. The image receiving sheet according to claim 1, wherein the layer has a light transmittance at 980 nm of less than 20%. 4. The image receiving sheet according to claim 1, wherein the layer contributes as a sensor mark for detecting the image receiving sheet. 5. The image receiving sheet according to claim 1, wherein a portion where the layer is not provided on the base sheet has a light transmittance at 980 nm of 70% or more. .