JP2000238416A - Recording sheet, method and apparatus for recording it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording sheet of various type performances stabilized in sensing performance of the sheet and incorporated capable of further reducing a space in the case of installing a sensor in a printer without evidence of a mark to be sensed for without obstruction to eyes. SOLUTION: In the recording sheet 1 comprising a layer 3 containing a near infrared absorption material having a maximum absorption in an arbitrary wavelength of 700 to 1,200 nm on part or non-continuously or overall surface of at least one side surface of a base material 2, a reflectivity of the arbitrary wavelength is 0<=A<=0.8, wherein A = reflectivity of the layer/reflectivity of the base material on the base material. Thus, the layer 3 is sensed by a reflection type sensor having a light emitting element and a light receiving element, and recording is started. Accordingly, sensing performance of the sheet is stabilized, there is no evidence to be an obstruction to eyes at the mark. Further, a space in the case of installing the sensor in the printer can be reduced, and various type performances can be incorporated in the sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet used in various types of printers such as a recording sheet for an electrophotographic copying machine, a recording sheet for an ink jet, a recording sheet for a fusion transfer, a recording sheet for a sublimation transfer, and a thermosensitive coloring paper. Regarding the sheet, especially, the detection performance of the recording sheet is stable, the mark part to be detected is not conspicuous so as not to be obstructive, and furthermore, various performances that can reduce the space when installing the detector with the printer are considered. The present invention relates to a variety of recording sheets and a recording method using the recording sheets.

[0002]

2. Description of the Related Art Conventionally, as non-impact printing, electrophotographic copying, ink jet recording, melt transfer recording, sublimation transfer recording, heat-sensitive color recording, and the like are used to print characters, symbols, images on plain paper or plastic-based recording sheets. It is widely used as a hard copy. For the above output, a copying machine or a printer is used to prevent the recording sheet from jamming in the machine, or in the case of color copying, etc., to register the image pattern of each color on the same recording sheet with registration. For this purpose, a detecting means is provided.

For example, light from a light source is applied to a recording sheet.
Further, if a mark is formed, an optical detecting means for hitting the mark portion and detecting the presence or absence of reflected light or transmitted light by a photo sensor is used. In addition, along with the performance improvement of copiers and printers and the expansion of recording applications,
Optical detection is used not only for the presence or absence of a recording sheet and for registering images of each color, but also for the type of recording sheet (OHP
, Plastic, plain paper, glossy paper, etc.)
It is beginning to be required to be identified.

[0004]

When a transparent sheet is used as a recording sheet, a method of detecting by providing an opaque part or a part with high reflectivity (mark) in a part of the transparent sheet has been disclosed in Japanese Patent Application Laid-Open No. Sho 60/1985. 244590 and JP-A-63-74680. However, in each of these methods, since an opaque portion is provided in a part of a transparent film, when the recording sheet is projected by an overhead projector (OHP), the opaque portion remains as a black shadow, There is a problem that it becomes obstructive. On the other hand, in JP-A-60-229032, JP-A-5-224481 and JP-A-8-114937, by providing a recording sheet with a portion having no light absorption in the visible region and having light absorption in the infrared region. There has been proposed a method of detecting a transparent sheet without impairing the appearance of the entire image at the time of OHP projection.

[0005] However, a light transmission type detector is often used as the above detecting means. In this case, the light emitting portion and the light receiving portion of the light source are a set, and the light emitting portion and the light receiving portion are provided on the recording sheet. They are installed on opposite sides of each other with a recording sheet in between. Therefore, the space for installing the detector is large in the design of the printer, and the printer device is likely to be complicated. When the transparent sheet is detected by a light reflection type detector, for example, if the member of the reflection surface of the detection mechanism is an infrared absorbing material or an infrared transmitting material such as black, there is no light absorption in the visible region, and there is no red absorption. A transparent sheet of a type having a portion having light absorption in the outer region is difficult to detect.

In the case of paper such as plain paper, detection can be performed by a light reflection type, but at present, it is not possible to distinguish between front and back and types. As described above, even if the recording sheet is a transparent sheet or an opaque one, the detection performance of the recording sheet is stable, and the mark part to be detected is not conspicuous so as to be annoying. The problem is that no space has been found that satisfies all of these requirements, since the space for installing the detector in the printer can be reduced. Therefore, the above-described problem is solved, the detection performance of the recording sheet is stabilized, and the mark portion to be detected is not conspicuous so as to be obstructive, and further, the space for installing the detector with the printer can be reduced. It is another object of the present invention to provide a recording sheet having various performances.

[0007]

In order to achieve the above-mentioned object, the present invention provides a method for manufacturing a semiconductor device in which at least one surface of a substrate is partially or discontinuously or entirely coated with 700 to 1200 nm.
In a recording sheet provided with a layer containing a near-infrared absorbing material having an absorption maximum at an arbitrary wavelength, the reflectance at the arbitrary wavelength is as follows: A = reflection of the near-infrared absorbing layer provided on the base material In the case of ratio / reflectance of the substrate, a relationship of 0 ≦ A ≦ 0.8 was given. The measurement of this reflectance is based on JIS Z
8722 (Method of measuring object color). The reflectivity here are specified in JIS Z 8120, and the radiation flux or the luminous flux phi _r of the reflected light is that the ratio φ _r / φ _i of the radiation flux or the luminous flux phi _i of the incident light, Specifically, an integrating sphere attachment device ISR-3100 was attached to a self-recording spectrophotometer UV-3100 manufactured by Shimadzu Corporation, and the specular reflectance of each was measured. In addition, the wavelength light of 700-1200 nm was used. However, in the case where the recording sheet is a transparent sheet, it is the reflectance when a standard white surface is placed on the back of the recording sheet. In this case, the common standard white surface is JIS Z872
2 (method of measuring object color).
The reflectances used in the present invention are all JIS Z 8722
Specular reflectance measured according to the method specified in. The reflectance of the substrate at the above-mentioned arbitrary wavelength is preferably 60% or more, and the reflectance of the near-infrared absorbing layer at the above-mentioned arbitrary wavelength is preferably 40% or less.

It is preferable that the near infrared absorbing layer contains a hue adjusting agent. Further, it is preferable that the upper layer and / or the lower layer of the near-infrared absorbing layer contain a hue adjusting agent. Further, the near infrared absorbing layer or the hue adjusting agent-containing layer is preferably the same as the hue of the substrate, and the hue is preferably white. Further, if a reflection type sensor is used, in the case of an opaque sheet, the front and back of the recording sheet can be easily distinguished by the near-infrared absorbing layer. The transmittance of the recording sheet at a wavelength of 400 to 700 nm is preferably 70% or more, and is often used as a transparent sheet. In this case, the transmittance is JIS
Z 8120 is defined in, that the radiation flux or the luminous flux phi _t of the transmitted light is that the ratio φ _t / φ _i of the radiation flux or the luminous flux phi _i of the incident light, the transmittance measurement JIS Z8
722. Specifically, the transmittance was measured using a self-recording spectrophotometer UV-3100 manufactured by Shimadzu Corporation.
Note that light having a wavelength of 400 to 700 nm was used. All the transmittances used in the present invention are measured according to the above-mentioned rules. According to a recording method of the present invention, a near-infrared absorbing layer is detected by a reflective sensor having a light-emitting element and a light-receiving element and recording is started using any of the recording sheets described above. Further, the recording apparatus of the present invention includes a recording sheet supply unit, a recording unit, a recording sheet discharge unit, a reflection type sensor having a light emitting element and a light receiving element is installed in the recording sheet supply unit, by the reflection sensor, The near-infrared absorbing layer of the recording sheet described in any of the above is detected, the recording sheet is conveyed from a recording sheet supply unit, and print recording is performed.
Further, in the reflection type sensor, 700 to 12 of the surface reflecting the sensor light facing the light emitting element and the light receiving element.
It is preferable that the reflectance at an arbitrary wavelength of 00 nm is 70% or more. Further, it is desirable that the emission wavelength of the above-mentioned reflection type sensor is 980 ± 10 nm.

The operation of the present invention is as follows. The recording sheet and the recording method of the present invention, a part or discontinuous of at least one surface on the substrate, or on the entire surface,
A layer containing a near-infrared absorbing material having an absorption maximum at an arbitrary wavelength of 700 to 1200 nm is provided. The reflectance at the arbitrary wavelength is as follows: A = Near-infrared absorbing layer provided on a substrate When the ratio of reflectance / reflectance of the substrate is satisfied, the relationship of 0 ≦ A ≦ 0.8 is satisfied. Thus, the near-infrared absorption layer is detected by the reflection type sensor having the light emitting element and the light receiving element, and recording is started. Therefore, the detection performance of the recording sheet is stable, the mark part to be detected is not noticeable, and the space for installing the detector with the printer can be reduced. A sheet is obtained. Furthermore, if n reflective sensors are attached, 2 ⁿ types of recording sheets can be selected. Also,
Naturally, it is also possible to determine the front and back of the recording sheet.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with respect to a recording sheet of the present invention. FIG.
1 is a schematic perspective view showing one embodiment of a recording sheet of the present invention. The recording sheet 1 has 7
A layer 3 containing a near-infrared absorbing material having an absorption maximum at an arbitrary wavelength of 00 to 1200 nm is provided, and a receiving layer 4 is provided on a substrate 2.

(Substrate) As the substrate 2 used in the recording sheet of the present invention, the same substrate as that used in the conventional recording sheet can be used as it is, and other substrates can be used. And is not particularly limited.
Condenser paper, glassine paper, sulfuric acid paper, or high-size paper, synthetic paper (polyolefin, polystyrene, etc.), fine paper, art paper, coated paper, cast-coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated Examples include paper, synthetic rubber latex-impregnated paper, synthetic resin internal paper, paperboard, cellulose fiber paper, and plastic film. Further, a composite base material in which two or more of these materials are bonded together is also used. In plastic films, for example, polyethylene, polyolefins such as polypropylene, polyethylene terephthalate, polyesters such as polyethylene naphthalate, polyvinyl chloride, polystyrene, polymethyl methacrylate, polycarbonate, cellophane, cellulose acetate, polyarylate, polyether sulfone, and the like. Can be In particular, when used for an overhead projector (OHP), a transparent substrate is used even for these plastic films.

For applications that do not require transparency other than OHP applications, opaque plastic films and papers are used. As an opaque plastic film, for example,
A white opaque film formed by adding a white pigment or a filler to the plastic synthetic resin described above and a foamed foamed sheet can also be used, and are not particularly limited. In addition, 70
When the reflectance at an arbitrary wavelength of 0 to 1200 nm is A = the reflectance of the near infrared absorbing layer provided on the substrate / the reflectance of the substrate, the relationship of 0 ≦ A ≦ 0.8 is satisfied. Is what you do. However, when the substrate is transparent, it is the reflectance when a standard white surface is placed on the back of the substrate. Further, it is preferable that the reflectance of the base material at an arbitrary wavelength of 700 to 1200 nm is 60% or more to satisfy the above relational expression. The thickness of the substrate is appropriately selected in consideration of the strength and the like according to the application, and is not particularly limited, but is, for example, usually about 10 to 300 μm. Further, one or both surfaces of the substrate may be subjected to a known easy adhesion treatment such as a primer treatment or a corona discharge treatment, if necessary.

(Near-Infrared Absorbing Layer) The near-infrared absorbing layer 3
A layer containing a near-infrared absorbing material having an absorption maximum at an arbitrary wavelength in the near-infrared region of 700 to 1200 nm, provided partially, discontinuously, or over the entire surface of a recording sheet base material. . Examples of the near-infrared absorbing material contained in the near-infrared absorbing layer include a diimonium-based compound, an anthraquinone-based compound, a metal complex-based compound, an aminium-based compound, a cyanine-based compound, and a benzopyrylium-based compound. Further, as the binder resin of the near-infrared absorbing material, polyester resin, vinyl chloride-vinyl acetate copolymer, polyurethane resin, polyvinyl butyral resin, phenoxy resin, acrylic resin, etc. are used. . In addition, if the same resin as the receiving layer resin described later is used, the ink can be normally received and fixed even when recording is performed on the near infrared absorbing layer.

The near infrared absorbing layer may contain a hue adjuster. For example, the near-infrared absorbing layer can be made to have a white hue to match the hue of the substrate. Examples of the hue adjusting agent include, for example, inorganic fillers such as silica, kaolin, clay, talc, silica, aluminum hydroxide, titanium dioxide, calcium carbonate, aluminum sulfate, and zinc oxide. , About 0.1 μm to 10 μm. Further, a layer containing a hue adjusting agent may be provided above and / or below the near-infrared absorbing layer to match the hue of the substrate. The reason why the hue of the near-infrared absorbing layer and the hue of the base material are the same is that the near-infrared absorbing layer portion to be detected does not become obtrusive and inconspicuous when projected with the naked eye or OHP. is there. Also, matching these hues to the same is only for recording sheets (genuine) guaranteed by the printer manufacturer,
By matching the hues as described above, it is possible to prevent unauthorized use of wrong products, imitation products, etc. of different types other than genuine products. Further, 700-
At an arbitrary wavelength of 1200 nm, a light scattering agent may be contained in order to reduce the reflectance. Further, a layer containing a light scattering agent may be provided on the near-infrared absorbing layer. Examples of the light scattering agent include inorganic and / or organic fillers. Examples of the light scattering agent include the inorganic fillers described in the above hue adjusting agent, and organic fillers such as acrylic resin, benzoguanamine resin, silicone, and Teflon.
The case where the light scattering agent is added to the near-infrared absorbing layer or provided as a new layer is when the recording sheet is opaque and the substrate is opaque.

The near infrared absorbing layer has a thickness of 700 to 1200 n.
When the reflectance at an arbitrary wavelength of m is A = the reflectance of the near infrared absorbing layer provided on the substrate / the reflectance of the substrate, the relationship of 0 ≦ A ≦ 0.8 is satisfied. It is. Also, 700-1200
It is preferable that the reflectance of the near infrared absorbing layer at an arbitrary wavelength of nm is 40% or less to satisfy the above relational expression. When the recording sheet is of an opaque type, the above-described near-infrared absorbing layer is formed on the front or back surface of the recording sheet, and the front and back of the recording sheet are distinguished by the near-infrared absorbing layer, and the recording of the recording sheet is performed. It is preferable and done to record exactly on the normal surface to be done.

The near-infrared absorbing layer is prepared by adding a near-infrared absorbing material, a hue adjusting agent, a light scattering agent and, if necessary, various auxiliaries to the above binder resin, and dissolving or dispersing in an appropriate solvent. The composition obtained is applied on a substrate by a known method, that is,
By forming means such as a gravure printing method, a screen printing method, a reverse roll coating method using a gravure plate,
Coated, dried and formed. The thickness of the near-infrared absorbing layer is usually about 0.1 to 50 μm in a dry state. The printing pattern of the near-infrared absorbing layer may be a pattern formed linearly at the end of the recording sheet 1 as shown in FIG. 1 or a square, circle, ellipse, triangle, or the like at one or more corners. A mark can be formed, and its shape and formation position are not limited. A near-infrared absorbing layer is preferably provided at the leading end (one end) of the recording sheet in the direction in which the recording sheet is conveyed in the printer and at a right angle to the direction of conveyance, as shown in FIG. Lines and discontinuous lines can be formed. In addition, by forming the near-infrared absorbing layer by classifying it with a variable pattern such as a bar code, the type of recording sheet (for OHP, for plastic, for plain paper, for glossy paper, etc.) can be detected and identified. It is possible. Above near infrared absorption layer, the recording surface side of the substrate,
Although it can be formed on any of the back sides, it is preferable to provide a near-infrared absorbing layer on the side where the light emitting element and the light receiving element are installed, particularly when the recording sheet is of an opaque type.

(Receiving Layer) The receiving layer 4 provided on one surface of the base material is formed directly on the base material or via a primer layer. The configuration of the receiving layer differs depending on the recording method such as electrophotographic copying, ink jet recording, melt transfer recording, and sublimation transfer recording. In electrophotographic copying, as the resin forming the receiving layer, polyethylene, polyolefin resin such as polypropylene, polyvinyl chloride,
Polyvinylidene chloride, polyvinyl acetate, vinyl chloride / vinyl acetate copolymer, polyacrylate, polyethylene terephthalate, polybutylene terephthalate, polystyrene resin, polyamide resin, olefins such as ethylene and propylene with other vinyl monomers Copolymers, ionomers, cellulose resins such as ethyl cellulose and cellulose acetate, polycarbonate resins, and the like can be mentioned, and particularly preferred are vinyl resins, polyester resins, and vinyl chloride / vinyl acetate copolymer resins.
Preferably, a polyester resin comprising a modified bisphenol A (diol component) and an acid component described in JP-A-7-219261 is used. The receiving layer is prepared by adding various auxiliaries to the resin as needed and dissolving or dispersing the composition in an appropriate solvent to prepare a composition on a substrate by a known method, that is, a gravure printing method or a screen printing method. It is applied and dried by a forming method such as a reverse roll coating method using a gravure plate or the like, and is formed by drying. The thickness of the receiving layer is usually 0.1 to 10 μm in a dry state.

Examples of the auxiliary agent to be added to the electrophotographic copying receiving layer include, for example, a fluorine-based polymer such as ethylene tetrafluoride polymer and ethylene-tetrafluoroethylene polymer, and stearic acid for the purpose of imparting lubricity. Stearates such as zinc, organic polymers such as polyethylene and polystyrene, silica, fine particles of inorganic substances such as alumina,
Waxes, silicone oils, surfactants, vegetable oils, animal oils, mineral oils and the like are used. Among them, fluorinated polymers are most suitable because the polymers themselves have excellent surface lubricity. In addition, organic polymer fine particles such as polyolefin fine particles such as polyethylene, polystyrene fine particles, polyacryl fine particles, ethylene acrylic acid copolymer fine particles, and silica, for the purpose of preventing double feed due to blocking generated when the recording sheet is supplied to the printer, silica, Inorganic fillers such as kaolin, clay, talc, silica, aluminum hydroxide, titanium dioxide, calcium carbonate, aluminum sulfate, and zinc oxide, and fine particles of glass beads can be added to the receptor layer. However, in the case of OHP, it is added in such an amount that the transparency of the receiving layer is not impaired.

The receiving layer of ink jet recording is roughly classified into two types of receiving layers. One is mainly composed of a hydrophilic resin, inorganic fine particles, and a filler.
It mainly comprises a mixture of a water-soluble polymer resin and a water-insoluble polymer resin. First, a resin mainly composed of a hydrophilic resin, inorganic fine particles and a filler is a resin which is insoluble in water at least at room temperature but has ink permeability as a hydrophilic resin. Examples of such a resin include polyvinyl formal, polyvinyl acetoacetal, polyvinyl propional, polyvinyl butyral, polyvinyl hexional, polyvinyl acetal resins such as polyvinyl phenyl acetal, polyalkyl vinyl ethers such as polyvinyl isobutyl ether, acrylic acid, Examples include hydrophilic acrylic resins and aqueous polyester resins synthesized from methacrylic acid or esters thereof. Examples of the inorganic fine particles in the receiving layer include white carbon such as silicic anhydride, hydrous silicic acid, hydrous calcium silicate, and hydrous aluminum silicate known as colloidal silica, and alumina sol. These inorganic fine particles usually have a particle size of 1
Fine particles of about 0 to 300 nm are used. The blending amount of the inorganic fine particles is hydrophilic resin / inorganic fine particles = 20/1 by weight ratio.
The range of １ ／ to 1/20, preferably 10/1 to 1/10 is used because it is good in terms of ink absorbency, drying properties and image quality. In addition, the filler of the above-mentioned receiving layer includes inorganic particles such as silica, clay, calcium carbonate, barium sulfate, alumina white, aluminum hydroxide, clay, talc, bentonite, and titanium oxide, or polymethyl methacrylate, polystyrene, and fluorine. Vinyl resin such as resin, polyolefin resin such as polyethylene and polypropylene, thermoplastic resin such as polyamide,
Organic fine particles made of a thermosetting resin such as a polybenzoguanamine resin and a urea resin are exemplified. These fillers have a particle size of 0.1 to 30 μm, particularly preferably 1 to 20 μm. Also,
The amount of the filler is preferably in the range of 0.1 to 10% based on the total solid content (hydrophilic resin + inorganic fine particles). In addition,
In the above-mentioned inkjet receiving layer, depending on the purpose, a non-hydrophilic resin, a surfactant, a preservative, a fungicide, an ultraviolet absorber, an antioxidant, a PH adjuster, an antifoaming agent and other additives, They may be appropriately mixed without departing from the performance.

The ink-jet recording receiving layer mainly composed of a mixture of a water-soluble polymer resin and a water-insoluble polymer resin means a polymer soluble in water at ordinary temperature as a water-soluble polymer resin. For example, polyacrylic acid, polymethacrylic acid or esters, salts and copolymers thereof, polyhydroxyethyl, methacrylate and copolymers thereof, starches, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, methylcellulose, hydroxyethylcellulose Water-soluble polymers such as cellulose derivatives can be preferably used. In addition, the water-insoluble polymer resin means a polymer that is insoluble in water at room temperature after forming a film, and may swell in water at room temperature. The water-insoluble polymer resin has a function of fixing the water-soluble polymer resin so as not to flow, and prevents uneven distribution of the ink on the film. The water-insoluble polymer resin is a water-dispersion type or water-soluble type polymer resin. Alternatively, an alcohol-soluble polymer resin may be used. Examples include water-dispersed polyester copolymers, water-dispersed acrylic copolymers, water-dispersed polyurethanes, methoxymethylated nylon resins, and cellulose esters. The mixing ratio of the water-soluble polymer resin and the water-insoluble polymer resin in the receiving layer of the inkjet recording is 1/9 to 9
/ 1, particularly preferably in the range of 1/1 to 9/1,
An optimum ratio is selected according to each component, type of ink, interval between dots, and the like. The method for forming the receiving layer for ink jet recording may be the same as that for the receiving layer for electrophotographic copying described above. The thickness of the receiving layer for inkjet recording is
When dried, it is 1 to 50 μm, preferably 5 to 25 μm.

The receiving layer for the melt transfer recording and the sublimation transfer recording is
It has the function of receiving the color material transferred from the thermal transfer sheet by heating, especially when the color material is a sublimable dye, accepts it, develops the color, and does not re-sublimate the dye once received. It is desired. This receiving layer
It is mainly composed of a receiving layer resin. The receiving layer resin is, for example, a resin having an ester bond, a resin having a urethane bond, a resin having an amide bond, a resin having a urea bond, a resin having a highly polar bond, or a mixture or copolymer resin thereof. For example, many resins can be used. In particular, a mixture of an ethylene-vinyl acetate copolymer and polyvinyl chloride is preferred. This receiving layer can be added with an organic or inorganic filler or the like as necessary to the above resin. Further, in the case of sublimation transfer recording, a release agent can be added in order to improve the thermal releasability from the thermal transfer sheet. The method for forming the receptor layer for the melt transfer recording and the sublimation transfer recording may be the same as that for the above-mentioned receptor layer for electrophotographic copying. The thickness of the receptor layer for melt transfer recording and sublimation transfer recording is usually 0.1 to 10 μm when dried.

(Antistatic layer) In order to prevent the recording sheet from being contaminated by dust and to ensure the stability of conveyance by various printers, an antistatic layer containing the following antistatic agent is placed on the receiving layer or on the substrate. Can be provided on the back surface of the. As the antistatic agent, any of conventionally known cations, anions, zwitterions and nonionics can be used.
Examples thereof include cationic antistatic agents such as quaternary ammonium salts and polyamine derivatives, anionic antistatic agents such as alkyl phosphates, and nonionic antistatic agents such as fatty acid esters. The antistatic layer may be added with the above antistatic agent and a lubricant such as an organic or inorganic filler, and a compounded solution obtained by dissolving or dispersing them in a solvent by a known method, that is, gravure coating, gravure reverse coating. It is formed by applying and drying by a method such as roll coating. The thickness of the antistatic layer is 0.001.
About 0.1 μm.

(Recording Method and Recording Apparatus) In the present invention, a recording method is described in which a near-infrared absorbing layer is detected by a reflective sensor having a light-emitting element and a light-receiving element using the above-mentioned recording sheet, and recording is started. . Further, the recording apparatus of the present invention includes a recording sheet supply section, a recording section, and a recording sheet discharge section, and a reflection type sensor having a light emitting element and a light receiving element is installed in the recording sheet supply section. The infrared absorbing layer is detected, the recording sheet is conveyed from the recording sheet supply unit, and printing is performed. FIG. 2 is a schematic diagram showing a configuration of the reflection type sensor 5 used when the recording sheet is a transparent sheet, and an infrared ray is generated from the light emitting element 6, and the ray is reflected by the reflection surface 8. And the light receiving element 7
Then, the reflected light beam enters as shown by the arrow. In practice, when the recording sheet 1 is inserted at the position shown by the dotted line and the amount of light rays entering the light receiving element 7 becomes less than a certain value, the light amount is converted into an electric signal, and the presence of the recording sheet,
The image forming start position on the recording sheet is read, and printing is started. The start of printing is to print first on a recording sheet in the case of single-color printing, and to start printing of the first color and then superimpose the colors in printing of two or more colors.
The meaning includes the start of printing of each color after the color. Although not shown, when the recording sheet is an opaque sheet, an infrared ray is generated from the light emitting element, and the ray is reflected on the surface of the recording sheet on which the near-infrared absorbing layer is provided. The reflected light enters, and the light reflecting surface becomes a recording sheet.

The above optical detection is based on the presence or absence of a recording sheet,
Not only is it used for registering images of each color, but also by classifying the near-infrared absorbing layer with a variable pattern such as a barcode, the type of recording sheet (for OHP, plastic, plain paper, glossy paper, etc.) ) Can be detected and identified. In the recording method of the present invention, as shown in FIG. 2, the light emitting element 6 and the light receiving element 7 of the reflection type sensor 5 to be used.
The surface 8 that reflects the sensor light facing the
It is preferable that the reflectance at an arbitrary wavelength of 00 to 1200 nm is 70% or more. That is, when detecting a transparent recording sheet, infrared rays of an arbitrary wavelength emitted from the light emitting element are reflected on the reflection surface before detection of the recording sheet and enter the light receiving element. When detecting the recording sheet, the near-infrared absorbing layer absorbs infrared light, reduces the amount of infrared light that enters the light receiving element, and increases the light amount difference between before and during detection so that recording start can be easily detected. In order to achieve this, the near-infrared reflectance of the reflecting surface is increased. As a surface having such a reflection surface, for example, a reflection plate having BaSO ₄ adhered to the surface is used, and the reflection surface is 700 to 1200.
The reflectance at an arbitrary wavelength of nm is set to be 70% or more.

[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) As a substrate, a 100 μm-thick polyethylene terephthalate (PET) transparent film (Toray Industries, Inc.)
Co., Ltd., Lumirror, T-60) was used, and a receiving layer coating solution having the following composition was applied on one surface of the coating so as to be 3 g / m ² when dried, and dried to form a receiving layer. Further, an antistatic layer coating solution having the following composition was applied to the front and back surfaces of the obtained sheet at a surface resistivity of 1 × 10 ¹⁰ Ω / □ at 23 ° C. and 50% RH.
Coated and dried to a degree. Next, as shown in FIG. 1, a near-infrared absorbing layer 1 having the following composition is applied on the receiving layer side by gravure printing so as to have a thickness of about 3 μm when dried, and formed by drying. The recording sheet of Example 1 was created.

Receptive layer coating liquid Polyester resin 35 parts (Polyester HP320, manufactured by Nippon Synthetic Chemical Co., Ltd.) Silica (average particle size 5 μm) 0.5 parts Methyl ethyl ketone 65 parts

Antistatic layer coating liquid Cationic quaternary ammonium salt 0.1 part Isopropyl alcohol 100 parts

NIR absorbing layer coating liquid 1 NIR absorbing agent (diimonium compound) 1 part (Nippon Kayaku Co., Ltd., IRG-022) Polyester resin 35 parts (Nippon Synthetic Chemical Co., Ltd.) , Polyester HP320) Methyl ethyl ketone 65 parts

(Example 2) The base material of the recording sheet prepared in Example 1 was changed to cast-coated paper (manufactured by Oji Paper Co., Ltd., Mirror Coat Gold), and one surface of the recording sheet was replaced with FIG.
In the arrangement as shown in the following, the near infrared absorbing layer 2 having the following composition is applied by gravure printing so as to be about 3 μm when dried,
The recording sheet was dried to form a recording sheet of Example 2.

Near infrared absorbing layer coating liquid 2 Near infrared absorbing agent (diimonium compound) 0.1 part (Nippon Kayaku Co., Ltd., IRG-022) Polyester resin 35 parts (Nippon Synthetic Chemical Co., Ltd.) HP320) Methyl ethyl ketone 65 parts

Example 3 A recording sheet of Example 3 was prepared in the same manner as in Example 2 except that a white PET film (Lumilar E20, manufactured by Toray Industries, Inc.) was used as the base material.

(Example 4) On the near infrared absorbing layer of the recording sheet prepared in Example 2, a hue adjusting layer 3 having the following composition was further applied, dried and formed. A recording sheet was created. Hue adjusting layer coating liquid Titanium trioxide (R-780-2, manufactured by Ishihara Sangyo Co., Ltd.) 26.7 parts Polyester resin 13.3 parts Methyl ethyl ketone 60 parts

(Example 5) On the near-infrared absorbing layer of the recording sheet prepared in Example 3, the hue adjustment layer coating liquid 3 used in Example 4 was further applied and dried. A recording sheet of Example 5 was created.

Example 6 Example 4 was applied to a base material of cast-coated paper (mirror coat gold, manufactured by Oji Paper Co., Ltd.).
The hue adjustment layer coating liquid 3 used in the above is applied and dried,
A hue adjustment layer was provided, and the near-infrared absorbing layer 2 used in Example 2 was similarly coated on the hue adjustment layer so as to have a dry thickness of about 3 μm, and dried to form a sixth example. Created a recording sheet.

(Example 7) The same white PET film (Lumirror E2 manufactured by Toray Industries, Ltd.) as in Example 3 was used as the substrate of Example 6.
Example 7 in the same manner as in Example 6 except that
Created a recording sheet.

Example 8 One side of a base material of cast coated paper (manufactured by Oji Paper Co., Ltd., Mirror Coat Gold) was arranged as shown in FIG. The infrared absorbing layer coating liquid 4 was applied so as to have a thickness of about 3 μm when dried, and dried to prepare a recording sheet of Example 8. Hue adjuster-containing near infrared absorbing layer coating liquid 4 Near infrared absorbing agent (diimonium compound) 0.1 part (manufactured by Nippon Kayaku Co., Ltd., IRG-022) Titanium oxide (manufactured by Ishihara Sangyo Co., Ltd.) R-780-2) 26.7 parts Polyester resin 13.3 parts (HP320, manufactured by Nippon Synthetic Chemical Co., Ltd.) Methyl ethyl ketone 60 parts

Example 9 White PET film having a thickness of 75 μm as a substrate (Lumilar E20, manufactured by Toray Industries, Inc.)
The coating liquid of the near infrared absorbing layer-containing layer 4 containing a hue adjusting agent was applied to a thickness of about 3 μm when dried on the substrate in the same manner as in Example 8, and dried. Created a sheet.

Example 10 On one surface of a base material of cast-coated paper (manufactured by Oji Paper Co., Ltd., Mirror Coat Gold), a light scattering agent having the following composition was arranged in an arrangement as shown in FIG. The near infrared absorbing layer coating liquid 5 was applied so as to have a thickness of about 3 μm when dried, and dried to prepare a recording sheet of Example 10. Light scattering agent-containing coating solution for near-infrared absorbing layer 5 Near-infrared absorbing agent (diimonium compound) 0.2 part (manufactured by Nippon Kayaku Co., Ltd., IRG-022) Silica particles 4 parts (manufactured by Fuji Syria Chemical, Acrylic resin 20 parts (manufactured by Mitsubishi Rayon Co., Ltd., BR-87) Methyl ethyl ketone 40 parts Toluene 30 parts

(Example 11) On the near-infrared absorbing layer of the recording sheet prepared in Example 2, a light scattering layer coating liquid 6 having the following composition was further coated so as to be about 3 μm when dried. Then, the recording sheet of Example 11 was dried. Light scattering layer coating liquid 6 Silica particles 10 parts (manufactured by Fuji Sicilia Chemicals, Sylysia 470, average particle diameter 12 μm) Acrylic resin 20 parts (manufactured by Mitsubishi Rayon Co., Ltd., BR-87) Methyl ethyl ketone 40 parts Toluene 30 parts

(Example 12) As a substrate, a thickness of 150 μm was used.
m synthetic paper YUPO FPG # 150 (Oji Yuka Co., Ltd.)
), And coated and dried on one surface thereof with a near-infrared absorbing layer coating solution 7 having the following composition by a wire bar so as to be 5.0 g / m ² when dried. A recording sheet for inkjet was prepared. Near infrared absorbing layer coating liquid 7 polyvinyl alcohol resin 10 parts (Kuraray Co., Ltd., PVA217) Near infrared absorbing agent (diimonium compound) 0.1 part (Nippon Kayaku Co., Ltd., IRG-022) Isopropyl alcohol 30 parts Water 60 parts

(Example 13) As a substrate, a thickness of 150 μm was used.
m synthetic paper YUPO FPG # 150 (Oji Yuka Co., Ltd.)
Coating solution 8 having the following composition on one surface thereof by a wire bar so as to be 4.0 g / m ² when dried with a wire bar, and then dried (110 ° C./30 seconds). Let me
The recording sheet for thermal transfer of Example 13 was prepared by being left at room temperature for 12 hours or more. NIR absorbing layer coating liquid 8 Polyester resin 19.7 parts (Toyobo Co., Ltd., Byron 200) Addition polymerization type silicone (Si4) 0.6 part Platinum catalyst (Shin-Etsu Chemical Co., Ltd., PL -50T) 0.4 part Reaction inhibitor (PLR-5, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 part Near infrared absorbing agent (diimonium-based compound) 0.1 part (manufactured by Nippon Kayaku Co., Ltd. IRG-022) Methyl ethyl ketone 39.45 parts Toluene 39.45 parts

The above-mentioned Si4 addition polymerization type silicone is a mixture of a vinyl modified silicone represented by the following chemical formula 1 and a hydrogen modified silicone represented by the following chemical formula 2, and 1 part by weight of the vinyl modified silicone is added to the hydrogen modified silicone 2
It is a mixture of parts by weight. However, the vinyl-modified silicone represented by the chemical formula 1 and the hydrogen-modified silicone represented by the chemical formula 2 have a phenyl group substitution rate of a methyl group; 30 mol% each; a molecular weight; about 7000 each; a reactive group amount of the vinyl modified silicone;
About 15 mol%, R _{2 of} hydrogen-modified silicone,
R ₃ has —CH _{3 at} both ends, —H at the side chain, and the amount of reactive group;
0 mol%.

[0043]

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(Comparative Example) A cast-coated paper (manufactured by Oji Paper Co., Ltd., Mirror Coat Gold) was used as a base material, and was arranged on the base material as shown in FIG. The outer absorbent layer coating liquid 9 was applied so as to be about 0.5 g / m ² when dried, and dried to prepare a recording sheet of a comparative example. NIR absorption layer coating liquid 9 Carbon black 1 part Polyester resin 1 part (Toyobo Co., Ltd., Byron 200) Methyl ethyl ketone 50 parts Toluene 50 parts

The recording sheets of each of the above embodiments and the comparative example are as follows.
The reflectance of the substrate and the near-infrared absorbing layer and the ratio are measured, and a printer having a self-made light reflection type sensor using infrared rays (electrophotographic method, ink jet method, and sublimation thermal transfer method). A test pattern was continuously printed and printed on 10 sheets each for the same sensor conditions such as sensor sensitivity, and the detection performance of the recording sheet and the appearance of the near infrared absorbing layer (mark portion) were examined.

(Evaluation method) [Reflectance] The reflectance of the base portion of the recording sheet and the mark portion of the near-infrared absorbing layer was measured by using a self-recording spectrophotometer UV-3100 (manufactured by Shimadzu Corporation) with an integrating sphere attachment device ISR-. 3100 was mounted, and the measurement was performed at a specular reflectance of 1600 nm to 400 nm.

[Detection Performance of Recording Sheet] The detection performance of the mark portion of the near-infrared absorbing layer was examined when continuously printing 10 recording sheets under the above conditions. The evaluation criteria are as follows. ；: All were detected, and there was no problem in printing. Δ: In some cases, the time interval until the start of printing of the recording sheet and the next recording sheet to be printed was increased during continuous printing despite the same sensor conditions.

[Appearance of Near-Infrared Absorbing Layer] The recording sheet of Example and Comparative Example before recording was compared with the portion where the near-infrared absorbing layer was formed and the other portions. Observation was made to determine whether or not the near-infrared absorbing layer was noticeable so as to be obstructive. The evaluation criteria are as follows. A: Near infrared absorbing layer is not conspicuous at all. ；: The near-infrared absorbing layer is not conspicuous. Δ: Near-infrared absorbing layer can be discriminated, but is of no concern. X: The near-infrared absorbing layer is conspicuous and obtrusive.

(Evaluation Results) The measured values of the reflectance of the near-infrared absorbing layer and the reflectance of the substrate at a wavelength of 1000 nm of each of the recording sheets of Examples and Comparative Examples, and A = provided on the substrate The reflectance of the near-infrared absorbing layer / the reflectance of the substrate was calculated, and the above evaluation results are summarized in the following table.

[0050]

[Table 1]

As is apparent from the above results, the method for making the hue of the near-infrared absorbing layer the same as that of the substrate differs depending on the material of the substrate. In this example, since the substrate is transparent or white, the appearance may be inferior, but depending on the hue of the substrate, it is very effective to match the hue of the near-infrared absorbing layer and the substrate. In some cases.

[0052]

The recording sheet and the recording method of the present invention can be partially or discontinuously or entirely coated on a substrate.
A layer containing a near-infrared absorbing material having an absorption maximum at an arbitrary wavelength of 700 to 1200 nm is provided, wherein the reflectance at the arbitrary wavelength is A = reflectivity of near-infrared absorbing layer / substrate When the reflectance is, the relationship is 0 ≦ A ≦ 0.8. Thus, the near-infrared absorption layer is detected by the reflection type sensor having the light emitting element and the light receiving element, and recording is started. Therefore, the detection performance of the recording sheet is stable, and the mark portion to be detected is not conspicuous so as not to be obstructive.Moreover, the space for installing the detector with the printer can be reduced, and various performances can be balanced.
An assortment of recording sheets can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing one embodiment of a recording sheet of the present invention.

FIG. 2 is a schematic diagram illustrating a configuration example of a reflection sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording sheet 2 Base material 3 Near-infrared absorption layer 4 Reception layer 5 Reflection sensor 6 Light emitting element 7 Light receiving element 8 Reflecting surface

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // G03G 15/00 510 B41M 5/26 H (72) Inventor Noritaka Egami Ichigaya Kagamachi, Shinjuku-ku, Tokyo 1-1-1 F-term in Dai Nippon Printing Co., Ltd. (reference) 2H072 HA06 2H086 BA02 BA12 BA31 BA41 2H111 AA26 AA27 AA42 AA43 CA02 CA03 CA04 CA33 CA41 3F048 AA01 AB01 DC14 4F100 AA20 AK42 AT00A BA02 CA22 CA30A CA30B EB GB JN06A JN06B YY00B

Claims (13)

[Claims] At least one surface of a substrate is partially or discontinuously or entirely coated with 700 to 1200 nm.
In a recording sheet provided with a layer containing a near-infrared absorbing material having an absorption maximum at an arbitrary wavelength, the reflectance at the arbitrary wavelength is as follows: A = reflection of the near-infrared absorbing layer provided on the base material A recording sheet having a relationship of 0 ≦ A ≦ 0.8 where ratio / reflectance of a substrate. However, in the case where the recording sheet is a transparent sheet, it is the reflectance when a standard white surface is placed on the back of the recording sheet. 2. The method according to claim 1, wherein the substrate has a reflectance of 60 at an arbitrary wavelength.
% Or more. 3. The recording sheet according to claim 1, wherein the reflectance of the near-infrared absorbing layer at the arbitrary wavelength is 40% or less. 4. The recording sheet according to claim 1, wherein the near infrared absorbing layer contains a hue adjusting agent. 5. The recording sheet according to claim 1, wherein a hue adjusting agent is contained in an upper layer and / or a lower layer of the near infrared absorbing layer. 6. The recording sheet according to claim 1, wherein the near infrared absorbing layer or the hue adjusting agent-containing layer has the same hue as that of the substrate. 7. The recording sheet according to claim 6, wherein the hue is white. 8. The recording sheet according to claim 1, wherein the front and back of the recording sheet are distinguished by the near-infrared absorbing layer. 9. The recording sheet according to claim 1, wherein the transmittance of the recording sheet at a wavelength of 400 to 700 nm is 70% or more. 10. A near-infrared absorbing layer is detected by a reflection type sensor having a light emitting element and a light receiving element and recording is started using the recording sheet according to any one of claims 1 to 9. Recording method. 11. A recording apparatus comprising a recording sheet supply section, a recording section, and a recording sheet discharge section, wherein a reflection type sensor having a light emitting element and a light receiving element is installed in the recording sheet supply section, and A recording apparatus comprising: detecting a near-infrared absorbing layer of a recording sheet according to any one of claims 1 to 9; conveying the recording sheet from a recording sheet supply unit; and performing print recording. 12. The reflection type sensor according to claim 7, wherein the light-emitting element and the light-receiving element have a surface 7 that reflects the sensor light.
The reflectance at an arbitrary wavelength of 00 to 1200 nm is 70% or more, wherein the reflectance is 70% or more.
Recording method and recording apparatus described in 1. 13. A recording method and a recording apparatus, wherein the reflection sensor according to claim 10 has an emission wavelength of 980 ± 10 nm.