JPH09109462A - Image forming method, image recording material and formed image recording body using the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image recording body having density gradation by a method in which after an image comprising two-value image density being formed with the use of an image forming material having an image forming layer on a support, density gradation is added to the image by heating and/or pressing. SOLUTION: An image forming layer 2 containing a coloring agent and disperse dye as required is laminated on a support 1 to make an image recording material. Or, the image forming layer 2 is laminated on the support 1 through a colorless or almost colorless intermediate layer 3 to make an image recording material. Next, after image exposure by high density energy light from the support 1 side of the image recording material, the image forming layer 2 of an exposure part is removed, an image recording body is subjected to pressing or heating-pressing treatment to push the end part of a high image density area to a low image density area, and an image recording body having density gradation is obtained from an image recording body of two-value image density.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method for imparting density gradation to an image having binary image density, an image recording body having density gradation formed by the method, and an image recording for forming the same. Regarding materials.

[0002]

2. Description of the Related Art Conventionally, a recording method has been known in which light energy such as a laser beam is focused and a material for recording is irradiated with light to melt and deform a part of the material, or to scatter, burn or evaporate and remove the material. ing. This method has an advantage that a high contrast can be obtained because it is a dry type that does not require a treatment liquid such as a chemical, and because only the light irradiation portion is melted and deformed, or scattered or evaporated. Therefore, various materials using this recording method have been proposed and used as resist materials, optical recording materials such as optical discs, and also as image recording materials that see themselves as a visualized image.

For example, as a resist material, Japanese Patent Laid-Open No.
9-5447, 59-105638, 62-1
No. 15153, etc., a method and material for photo-decomposing a binder resin by pattern exposure to form a resist pattern, and as an optical recording material such as an optical disk, JP-A Nos. 55-132536 and 57-27788, Same 5
Image-exposing an inorganic compound thin film provided in 7-103137 or the like by vapor deposition to melt and deform a metal to record information, and JP-A-64-56591.
JP-A-1-99887 and 6-40163 propose methods and materials relating to a binder removal system containing a dye, which converts light energy into heat energy.

[0004]

On the other hand, as an image recording material and an image recording method, US Pat. No. 4,245,003 is used.
JP-A-58-18290 discloses a material provided with an image forming layer containing graphite or carbon black.
No. JP-T4-506709, JP-A-6-43635
Nos. 5,156,938 and 5,171,
No. 650, No. 5,256,506 and the like describe an image recording material provided with an image forming layer containing a photothermal conversion substance that absorbs laser light and converts it into heat energy and a binder that can be decomposed by heat as essential components. Proposed. In addition, JP
In No. 327982 and No. 4-327893, a photothermal conversion layer formed of a vapor deposition layer containing a substance that absorbs laser light and converts it into heat energy, and a layer containing a colorant are sequentially laminated on a support. A method for forming an image by irradiating an image recording material with a laser beam to melt the vapor deposition layer to change the adhesiveness and peeling off the overlapped image receiving sheets, and materials used therefor have been proposed.

Further, Japanese Patent Laid-Open Nos. 61-6103 and 61-
11688, 61-11689 and 61-284.
In No. 487, a recording layer having a non-self-oxidizing binder, a high light-shielding fine particle absorbing heat, and a protective layer are laminated in this order on a support, and the recording layer is irradiated with laser light from the support side. There is proposed a method and a material for recording an image by burning or squirting and transferring the image onto a transfer image receiving surface which is in contact with the protective layer.

By the way, in the image recording method using the above-mentioned image recording material, only an image recording body having a binary image density can be produced, and a digital output image by a laser beam or the like which has become popular recently. It was difficult to express gradation.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for imparting gradation to an image having binary image density and an image recording material used therefor, The object is to obtain an image recording body having gradation.

[0008]

The above object of the present invention can be achieved by the following constitutions. That is, an image forming method in which an image having a binary image density is formed using an image forming material having an image forming layer on a support, and then a density gradation is imparted to the image by heating and / or pressing. A dye is contained in a high density area of an image composed of binary image density, and a surface formed with an image of a binary image density containing a dye in a high density area is heated and heated. / Or by applying a pressure to the protective layer to give a density gradation to the image, and an image composed of binary image density, the image of the exposed portion of the image forming layer It is formed by reducing the bonding force with the support and removing the exposed portion.

An image recording body on which an image having density gradation is formed by the above method.

An image recording material having an image forming layer containing a non-diffusible colorant and a diffusible dye on a support, and an image forming layer composed of a plurality of layers, other than the image forming layer closest to the support. Including a dye in the image forming layer.

The image forming method and the image recording material of the present invention will be described in detail below.

<Image Forming Method> The image forming method of the present invention for imparting density gradation to an image composed of binary image densities depends on the type of material used for preparing the image recording material.
It is roughly divided into two methods, and each method will be described below.

-First Image Forming Method- In the first image forming method, an image having a binary image density is formed by using an image forming material having an image forming layer on a support, followed by heating and / or heating. Alternatively, a density gradation is imparted to the image by applying pressure, and a diffusible dye is contained in a high density region of the image composed of binary image density,
This is heated and / or pressurized to move the dye in the high image density area to a part of the low image density area.
It is also possible to give a density gradation to an image recorded with a value image density. This creating method will be described in detail below with reference to the drawings.

The image forming method of the present invention can be applied without particular limitation as long as it is an image recorded with a binary image density (for example, it is recorded with a binary image density formed by gravure or offset printing. Things that are)
However, an example in which a binary image is recorded by imagewise image information will be described.

As an image recording material used in a method in which an image having binary image densities is formed in advance and then density gradation is provided, for example, (a) a support as shown in FIG. 1 is used. An image forming layer containing a colorant and, if necessary, a diffusible dye, (b) a colorless or nearly colorless intermediate layer on a support, and an image forming layer containing a colorant and a diffusible dye. Those that are laminated in order are listed, and a method of making them will be described below.

First, as shown in FIG. 2 (a), image exposure with high-density energy light is performed from the support side of the image recording material, and then the image forming layer in the exposed portion is removed to obtain the image shown in FIG. An image recording body at the stage of recording with the binary image density shown in a) is prepared. This image recording material is pressed, and in some cases heated and pressed, the end of the area with high image density is pushed to the area with low image density as shown in FIG. An image recording body having a density gradation can be created from an image recording body having an image density.

In this case, the high-density energy light used for image exposure from the support side can be used without particular limitation as long as it is a light source capable of removing the exposed portion by some method. Among them, in order to obtain high resolution, an electromagnetic wave whose energy application area can be narrowed down, especially a wavelength of 1 nm to 1 mm
, Ultraviolet rays, visible rays, and infrared rays are preferable, and examples of light sources capable of applying such high-density energy light include lasers, light-emitting diodes, xenon flash lamps, halogen lamps, carbon arc lamps, metal halide lamps, tungsten lamps, and quartz mercury. A lamp, a high pressure mercury lamp, etc. can be mentioned. The energy applied at this time depends on the type of image forming material, the exposure distance, the time,
By adjusting the strength, it can be selected as appropriate.

When the high-density energy light is collectively exposed, a mask material having a negative pattern of a desired exposure image formed of a light-shielding material may be overlaid and exposed.

When an array type light source such as a light emitting diode array is used, or when a light source such as a halogen lamp, a metal halide lamp or a tungsten lamp is exposed and controlled by an optical shutter material such as liquid crystal or PLZT, an image signal is used. According to this, it is possible to carry out digital exposure according to the method, and in this case, direct writing can be performed without using a mask material. However, in this method, a new optical shutter material is required in addition to the light source. Therefore, in the case of digital exposure, it is preferable to use a laser as the light source.

When a laser is used as the light source, it is possible to focus the light into a beam and perform latent exposure by scanning exposure according to the image data. Further, when a laser is used as the light source, the exposure area is increased. It is easy to narrow down to a minute size and high-resolution image formation becomes possible. As such a laser light source, solid lasers such as a ruby laser, a YAG laser, and a glass laser, which are generally well known; He-Ne laser, Ar ion laser, Kr ion laser, CO ₂ laser, CO laser, He-
Gas lasers such as Cd lasers, N ₂ lasers and excimer lasers; InGaP lasers, AlGaAs lasers, GaAsP lasers, InGaAs lasers, I
Examples thereof include semiconductor lasers such as nAsP laser, CdSnP ₂ laser and GaSb laser; chemical lasers, dye lasers and the like. Among these, in order to efficiently remove the exposed portion, the wavelength is 600 to 1200.
It is preferable to use a laser of nm in terms of sensitivity because light energy can be efficiently converted into heat energy. Further, among these, a laser of 750 to 1200 nm is more preferable in terms of sensitivity because it can efficiently convert light energy into heat energy.

In the above-described image recording material, after the image recording material is imagewise exposed to high-density energy light, the image forming layer in the exposed portion is removed by some method to record at a binary image density. The image recording material of No. 1 is produced. As a method of removing the exposed portion at this time, if the exposure energy of the high-density energy light is sufficient to completely destroy and scatter the image forming layer, The scattered material can be removed by suction, and in this case, it can be efficiently removed by providing a suction portion in a portion adjacent to the image forming layer.

Further, in the case where the exposure energy of the high-density energy light does not completely destroy the image forming layer, for example, when the binding force between the support of the exposed portion and the image forming layer is lowered, the above-mentioned is mentioned. In addition to removal by suction, the exposed portion of the image forming layer exposed to high-density energy light is pulled out to the adhesive sheet side by contacting the adhesive layer or the adhesive layer surface of the adhesive sheet having the adhesive layer or adhesive layer on the substrate. This makes it possible to create an image recording body at the stage where the image is recorded with a binary image density. Incidentally, the term "decrease in binding force" as used herein means that the colorant layer is partially destroyed and / or scattered by a physical or chemical change, the colorant layer surface is not destroyed, and only the vicinity of the support physically or Includes phenomena such as chemical changes.

As the adhesive sheet in this case, a commercially available adhesive sheet, a heat sealing material, a laminating material or the like can be used as it is. Further, in order to press or heat and press the image recording material and the pressure-sensitive adhesive sheet to face each other,
It can be used without particular limitation as long as it can be adhered and can be pressed or heated and pressed without inclusion of bubbles and the like,
A pressure roll, a stamper, or the like can be used for pressurization, and a thermal head, a heat roll, a hot stamp, or the like can be used for heat and pressure treatment.

The pressure when a pressure roll is used is usually 0.1 although it cannot be generally stated depending on the type of image recording material.
~ 20 kg / cm, preferably 0.5-10 kg / cm
The transport speed is usually 0.1 to 200 mm /
Second, preferably 0.5 to 100 mm / sec, and the pressure when using a stamper is usually 0.05 to 10 mm.
kg / cm ^2, preferably from 0.5 to 5 kg / cm ^2, also,
Pressurization time is usually 0.1 to 50 seconds, preferably 0.5 to
20 seconds. Further, the thermal head can be used as it is under the conditions used in ordinary melt transfer, sublimation transfer and the like. The heating temperature when using a heat roll is
It is usually in the range of 60 to 200 ° C., preferably 80 to 180 ° C., the pressure is usually 0.1 to 20 kg / cm, preferably 0.5 to 10 kg / cm, and the conveying speed is
Usually 0.1 to 200 mm / sec, preferably 0.5 to 10
0 mm / sec, and the heating temperature when using a hot stamp is usually 60 to 200 ° C., preferably 80 to 200 ° C.
In the range of 150 ° C, the pressure is usually 0.05 to 10 k
g / cm ² , preferably 0.5 to 5 kg / cm ² , and the heating time is usually 0.1 to 50 seconds, preferably 0.5 to 2
0 seconds.

As a peeling method, a peeling plate, a peeling angle fixing method using a peeling roll, a manual peeling method of peeling the adhesive sheet and the image recording material without fixing them by hand, as long as they do not affect the image formation. Various peeling methods can be used.

Although the above description has been made on the image forming material in which a single image forming layer is provided on the support, when the image recording layer is composed of two or more layers, the same as the above case. The bond strength between the support and the image forming layers adjacent to the support may be reduced, or when a plurality of image forming layers having different compositions are provided on the support, the position where the bond strength is reduced is It may be between the image forming layers. Also, FIG.
In the case where an intermediate layer is provided between the image forming layer and the support as shown in (b), the position where the bonding force is lowered may be between the support and the intermediate layer as shown in FIG. 2 (b). It may be between the intermediate layer and the image forming layer.

When the image recording material at the stage of recording with binary image density as shown in FIG. 2B is provided with density gradation, it can be prepared by the above-mentioned method. In the case where a dye is contained in a region having a high image density, the image forming layer on the support is not deformed by heating or heating and pressurizing the dye in FIG. By thermally diffusing the layers, an image recording body having a density gradation as shown in FIG. 4B can be created.

By the method as described above, an image recording body having a density gradation can be prepared from a recording medium of an image having a binary image density. At this time, the heating and / or pressure treatment is This can be performed by using a known processing means. As such a processing means, for example, a processing device such as an oven or a thermal head in the heat treatment, or a processing device such as a pressure roll or a stamper in the pressure treatment,
For heat and pressure treatment, heat roll, hot stamp,
A processing device such as a thermal head can be appropriately selected and used depending on the type of the image recording material. In addition, as a condition of each processing apparatus, the heating temperature when using an oven is usually 50 to 200 ° C., preferably 70 to 180 ° C.,
The heating time is usually 5 to 1000 seconds, preferably 30 to 6
00 seconds. Further, for the pressure roll, stamper, heat roll, hot stamp, thermal head, etc., the above-mentioned processing conditions of pressing or heating and pressing the image recording material and the pressure-sensitive adhesive sheet to face each other can be used as they are. It is preferable to perform the treatment at a higher pressure or a higher temperature than the treatment conditions of

In the above-described image forming method, the case where the image forming layer is not present in the area where the image density is low has been described.
As for the binary image density, a region having a low image density may be colored as long as the density can be identified. Further, in the image recording material shown in FIG. 1 or 2, the constitution of the support, the intermediate layer and the image forming layer has been explained, but an image recording material as shown in FIG. 5 in which an adhesive sheet is previously provided on the image forming layer is also used. It can be preferably used. When such an image recording material is used, an image can be formed without causing scattering of the image forming layer.

-Second Image Forming Method- In the second image forming method, the area of high image density of the image recording material at the stage of recording with binary image density contains a dye. A protective layer is transferred and formed on the image forming surface of the image recording body by pressure and / or heat and pressure, and the dye in the high image density area is moved to a part of the low image density area to obtain density gradation. It is an image forming method to have,
This creating method will be described in detail below with reference to the drawings.

The image recording material used in this second image forming method is as shown in FIG. 1 described in the first image forming method.
In addition to those shown in FIG. 5, an adhesive sheet shown in FIG. 5 is laminated in advance, or an image forming layer obtained by laminating a layer containing a dye and a layer containing a colorant as shown in FIG. It is also possible to select and use an image recording material having a timely, it is preferable to contain a colorant in addition to the dye when the density of the image is required, and by exposing the image forming layer by image exposure with high-density energy light. By reducing the binding force of the exposed part with the support and removing the exposed part.
When forming a value image, in order to avoid the coloring of the support due to scattering of the image forming layer when reducing the binding force with the support, in other words, the residual density of the image forming layer in the low image density area. In order to lower the image forming ratio, it is preferable that the image forming layer is composed of a plurality of layers, and the dye is contained in the image forming layers other than the image forming layer closest to the support.

Next, the forming method will be described. First, the image recording material of FIGS. 5A and 6B is subjected to image exposure with high-density energy light from the support side as in the first image forming method. Then peel off the release sheet,
By removing the image forming layer in the exposed portion, an image recording body at the stage of recording with the binary image density shown in FIG. 7 is created. The image recording body is pressed against the protective layer such as the transfer foil shown in FIG. 8A or the laminated sheet shown in FIG. By diffusing the dye contained in the high image density area into the protective layer as shown in FIG.
It is possible to create an image recording material having a density gradation from an image recording material having an image density of a value.

In this case, as the high-density energy light used for image exposure from the support side, the high-density energy light used in the first image forming method can be appropriately selected and used. Further, the peeling sheet peeling method includes a peeling plate, a peeling angle fixing method using a peeling roll, a manual peeling method of peeling the adhesive sheet and the image recording material without fixing them by hand. Various peeling methods can be used as long as they do not affect the formation of the recording body. As a method of pressurizing the image recording body and the protective layer at the stage of the binary image density prepared as described above, and optionally applying heat and pressure, an adhesive sheet is attached by the first image forming method. The method used for this purpose can be appropriately selected and used.

In this method, the dye contained in the area having a high image density is diffused in the protective layer to give a density gradation. In other words, the diffusivity of the dye into the protective layer determines the density gradient between the high image density area and the low image density area. Therefore, depending on the type of dye contained in the image forming layer, the material of the layer of the protective layer that adheres to the image forming layer, or the method of pressure or heat pressure treatment, an image recording material having various gradations is obtained. You can

Next, the image recording materials used in these methods will be described in detail.

<Image-Recording Material> The image-recording material of the present invention comprises an image-forming layer laminated on a support, and is a high density energy light used for image exposure from the support side as in the above-mentioned image-recording method. In the case of irradiating with, the image forming layer is provided on the transparent support.

Examples of such transparent support include acrylic acid ester, methacrylic acid ester, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate,
Each resin film of polyvinyl chloride, polyethylene, polypropylene, polystyrene, nylon, aromatic polyamide, polyetheretherketone, polysulfone, polyethersulfone, polyimide, polyetherimide, etc., and two or more layers of the above resin are laminated. Resin films and the like can be mentioned.

In the present invention, the transparent support is preferably stretched into a film and heat-set from the viewpoint of dimensional stability, and titanium oxide, zinc oxide, barium sulfate, calcium carbonate and the like are used within the range not impairing the effects of the present invention. The filler may be added. The thickness of the transparent support is 10 to 500 μ.
m, preferably 25 to 250 μm.

The image-forming layer of the present invention contains a diffusible dye in order to provide gradation, and as such a dye, conventionally known dyes can be appropriately selected and used. When the dye is diffused in the intermediate layer or the protective layer to provide density gradation, it is preferable to use a heat diffusible dye (pigment). The heat-diffusible dye referred to here means one that is uniformly present in the layer, and is different from the coloring agent described later. As such a heat diffusible dye, dyes that have been conventionally used can be used as they are, naphthoquinone dyes, anthraquinone dyes, azomethine dyes, indoaniline dyes, etc., azo dyes, methine dyes, Quinophthalone dyes, anthryothothiazole dyes, cyanine dyes, rhodacyanine dyes, oxonol dyes,
Examples include carbocyanine dyes, dicarbocyanine dyes, tricarbocyanine dyes, tetracarbocyanine dyes, pentacarbocyanine dyes, styryl dyes, pyrylium dyes, phthalocyanine dyes, and alloy dyes. It is preferable that the dye is usually contained in the image forming layer forming component in an amount of about 0.1 to 60% by weight, and 0.5 to 40% by weight provides a contrast between a high density region and a low density region. To more preferred.

Further, only the heat diffusible dye may be used as a coloring component, but the image exposure with high-density energy light reduces the binding force with the support in the exposed portion of the image forming layer to give a binary image density. In the case of producing an image recording material at the stage of being recorded by, it is preferable to contain a colorant having absorption for high density energy light, particularly laser light having a wavelength of 600 to 1200 nm. In addition, the colorant in the present invention refers to a pigment, and as such a colorant, a pigment composed of an organic compound and / or an inorganic compound can be appropriately selected and used. Is, for example, 600 to 1200n
Specific examples of the pigment having absorption in the wavelength range of m include phthalocyanine, perylene, squarylium, and azo pigments. In addition, examples of pigments made of inorganic compounds include metal oxide powders such as graphite, carbon black, titanium black, cobalt trioxide, iron oxide, chromium oxide, and copper oxide, metal nitride powders, metal carbide powders, metal sulfide powders. And a pigment made of various magnetic powders used in magnetic paints and the like.

Among the above-mentioned coloring agents, those in which the coloring agent is present in the layer in a uniformly dispersed state and the coloring agent itself is not porous can obtain an image with a small residual ratio in the image-exposed portion. Among these, as the colorant, metal oxide powder, metal nitride powder, metal carbide powder or various magnetic powders used in magnetic ink and the like can be mentioned.
In order to obtain a high-resolution image among these, the particle size is 0.
It is preferably 5 μm or less, more preferably 0.3 μm or less.

When magnetic powder is used as the coloring agent,
Ferromagnetic iron oxide powder, ferromagnetic metal powder, cubic crystal plate powder and the like can be appropriately selected and used, and among them, ferromagnetic metal powder can be preferably used, and the shape of the ferromagnetic powder is The major axis diameter is 0.30 μm or less, preferably 0.20
It is preferably not more than μm, and by using such a ferromagnetic powder, not only an image having a small residual ratio of the exposed portion can be obtained, but also the surface property of the image forming layer is improved.

Such a coloring agent is preferably contained in the image forming layer forming component in an amount of 20 to 95% by weight, and preferably 40 to 90% by weight.
It is more preferable to use the weight% because the contrast between the high density region and the low density region can be obtained.

The image forming layer contains a binder resin in addition to the above dyes and colorants. As such a binder resin, any binder resin can be used without particular limitation as long as it can sufficiently hold the dye and colorant, and polyurethane, polyester, vinyl chloride-glycidyl ether copolymer and vinyl chloride-vinyl acetate copolymer can be used. Vinyl chloride resin such as polymer, polyolefin resin such as butadiene-acrylonitrile copolymer, polyvinyl acetal resin such as polyvinyl butyral, cellulose resin such as nitrocellulose, ethyl cellulose or cellulose diacetate, styrene-butadiene copolymer And the like, acrylic resins such as polymethylmethacrylate, polyamides, phenol resins, epoxy resins, phenoxy resins and the like.

Further, the binder resin is a thermosetting resin or an active energy curable resin when the image forming layer is formed by applying a coating liquid for forming an image forming layer on a transparent support and then curing it. Conventionally known materials such as resins and moisture curable resins may be used. As such a thermosetting binder resin used for thermosetting and a curing agent added as necessary, a binder resin having a hydroxyl group, a carboxylic acid group or a sulfonic acid group, and a curing agent having an isocyanate group, epoxy Examples thereof include a group-containing binder resin or curing agent, and an amino group-containing binder resin or curing agent or a binder resin or curing agent containing an acid anhydride. Further, a resin which can be heat-cured using a catalyst or the like can be selected at appropriate times. Can be used. In the active energy ray curing, a conventionally known combination of a compound having an ethylenically unsaturated double bond or a compound having an epoxy group and a polymerization initiator can be used.

The content of the binder resin in the image forming layer is about 5 to 80% by weight, preferably 10 to 60% by weight based on the components for forming the image forming layer.

In the image forming layer, in addition to the above-mentioned components, a lubricant, a durability improver, and
Additives such as dispersants, antistatic agents, fillers and fillers may be included.

Examples of lubricants include fatty acids, fatty acid esters, fatty acid amides, (modified) silicone oils, (modified) silicone resins, fluororesins, fluorocarbons, and the like. Durability improvers include polyisocyanates and the like. Can be mentioned. Examples of the dispersant include fatty acids having 12 to 18 carbon atoms such as lauric acid and stearic acid and their amides, alkali metal salts, alkaline earth metal salts; polyalkylene oxide alkyl phosphates, lecithin, trialkyl polyolefin oxy Quaternary ammonium salts; azo compounds having a carboxyl group and a sulfone group and the like can be mentioned.

Examples of the antistatic agent include cationic surfactants, anionic surfactants, nonionic surfactants, polymeric antistatic agents, conductive fine particles and the like, as well as "11290 chemical products", Chemical Industry Daily Co., Ltd. , P. And the compounds described in 875-876 and the like.

As the filler, carbon black, graphite, TiO ₂ , BaSO ₄ , ZnS, MgC are used.
O ₃ , CaCO ₃ , ZnO, CaO, WS ₂ , MoS ₂ , M
gO, SnO ₂ , Al ₂ O ₃ , α-Fe ₂ O ₃ , α-FeO ₂
H, SiC, CeO ₂ , BN, SiN, MoC, BC,
Inorganic fillers such as WC, titanium carbide, corundum, artificial diamond, garnet, garnet, quartzite, triboli, diatomaceous earth, dolomite, polyethylene resin particles, fluorine resin particles, guanamine resin particles, acrylic resin particles, silicone resin particles, melamine Organic fillers such as resin particles can be used.

The amount of these additives added is about 0 to 20% by weight, preferably 0 to 15% by weight.

The thickness of the image forming layer is 0.05 to 5.0 μm.
m, preferably in the range of 0.1 to 3.0 μm.
The image forming layer may be composed of a single layer or multiple layers having different compositions.

In particular, in the case of forming a binary image by lowering the binding force between the exposed portion of the image forming layer and the support by image exposure with high density energy light and forming a binary image by removing the exposed portion. In order to avoid coloring of the support due to scattering of the forming layer, in other words, to reduce the residual density of the image forming layer in the area where the image density is low, the image forming layer is composed of a plurality of layers and is not adjacent to the support. It is preferable that the image forming layer contains a dye.

The image-forming material of the present invention has the following properties in order to improve the adhesiveness and coatability within a range that does not impair the effects of the present invention.
Corona discharge treatment of support, anchor coat (intermediate layer)
It may be modified by a known surface modification technique such as treatment, or may have a layer such as a backing layer on the back surface of the support for the purpose of preventing electrification, transportability, and preventing feeding of a plurality of sheets. When an intermediate layer or a backing layer is provided, the thickness is preferably about 0.001 to 10 μm, more preferably 0.005 to 5 μm.

The image recording material of the present invention has the structure shown in FIG.
When an image recording body having a binary image density is formed by peeling after image exposure as in (b), a release sheet laminated on the image forming layer can be used. Such a release sheet may be formed as a release sheet by forming a layer of a resin having self-supporting property, or a resin film used as a support as described above may be used as the release sheet. An adhesive layer may be provided between the release sheet and the image forming layer.

Such an adhesive layer may be either one having adhesiveness at room temperature itself or one exhibiting adhesiveness by applying heat or pressure. For example, a resin having a low softening point, an adhesiveness-imparting agent, It can be formed by appropriately selecting a hot solvent, a filler and the like.

The thickness of the release sheet is about 0.1 to 100 μm, preferably 0.5 to 50 μm, and the thickness of the adhesive layer is about 0.1 to 40 μm, preferably 0.3 to 30 μm.
It is.

The image-forming layer is formed by kneading and dispersing the image-forming layer-forming composition made of the above-mentioned various materials in a solvent to prepare a coating material, applying the coating material on a support, and drying. As the solvent, alcohols (ethanol, propanol, etc.),
Cellosolves (methyl cellosolve, ethyl cellosolve), aromatics (toluene, xylene, chlorobenzene, etc.), ketones (acetone, methyl ethyl ketone, etc.),
Ester-based solvents (ethyl acetate, butyl acetate, etc.), ethers (tetrahydrofuran, dioxane, etc.), halogen-based solvents (chloroform, dichlorobenzene, etc.), amide-based solvents (dimethylformamide, N-methylpyrrolidone, etc.), etc. are used. be able to. Further, for kneading and dispersing the colorant layer components, a two-roll mill, a three-roll mill, a ball mill, a pebble mill, a cobol mill, a tron mill, a sand mill, a sand grinder, a Sqegvari attritor, a high speed impeller disperser, a high speed stone mill, a high speed impact mill. , Disperser, high speed mixer, homogenizer, ultrasonic disperser, open kneader, continuous kneader and the like can be used.

The image-forming layer can be formed on the support by a conventionally known gravure roll coating method, extrusion coating method such as extrusion method, wire bar coating method, roll coating method, and the like. In order to improve the smoothness of the surface of the image forming layer, calendar processing may be performed.

When a plurality of types of image forming layers are provided, the coating and drying may be repeated for each layer, or they may be applied in multiple layers by a wet-on-wet system and dried. In that case, reverse roll, gravure roll, air doctor coater, blade coater, air knife coater, squeeze coater, impregnation coater, bar coater, transfer roll coater, kiss coater, cast coater or spray coater and the like can be applied by a combination with an extrusion coater. In the wet-on-wet multi-layer coating, the upper layer is applied while the lower layer is in a wet state, so that the adhesion between the upper and lower layers is improved.

When the release sheet is laminated on the image forming layer, it may be adhered to the image forming layer in advance, or may be simply adhered to prevent the scattering.

[0062]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto. In the following, "parts" represents "parts by weight as active ingredients" unless otherwise specified.

Example 1 <Image recording material> 1) A transparent polyethylene terephthalate film [manufactured by Diafoil Hoechst Co., Ltd., T having a thickness of 100 μm, antistatic treated on one side and corona discharge treated on the laminated surface of the image forming layer
100G], the following composition was kneaded and dispersed using an open kneader to prepare an image forming layer forming coating solution, which was applied by extrusion coating on a support and then dried, followed by calendering. An image recording material was prepared by forming a 1.2 μm thick image forming layer by surface treatment.

Fe—Al based ferromagnetic metal powder 100 parts [Fe: Al atomic number ratio = 100: 4 (whole), Fe: Al atomic number ratio = 50: 50 (surface), average major axis diameter: 0.14 μm , Hc: 1760 Oersted, σs: 120 emu / g, BET: 53 m ² / g] Vinyl chloride resin [manufactured by Nippon Zeon Co., Ltd., MR-105] 12.5 parts Polyurethane resin [manufactured by Toyobo Co., Ltd., UR-8700] 12.5 parts α-alumina [average particle size = 0.15 μm] 8.0 parts carbon black [average particle size = 0.04 μm] 0.5 part stearic acid 1.0 part butyl stearate 1. 0 part Thermal diffusible dye 1 1.1 parts [Sand, Foron Brilliant Yellow S-6GL] Thermal diffusible dye 2 1.7 parts [Mitsui Toatsu Co., Ltd., MS Red G] Thermal diffusivity Element 3 1.1 parts [Made by Bayern, Macrolex Red Violet R] Thermal diffusion dye 4 3.3 parts [Mitsui Toatsu Co., Ltd., MS Cyan VPG] Cyclohexanone 100 parts Methyl ethyl ketone 100 parts Toluene 100 parts 2) Thickness The following composition was kneaded and dispersed using an open kneader on a transparent polyethylene terephthalate film [T60, manufactured by Toray Industries, Inc.] having a 100 μm-thick laminated surface for image forming layer corona discharge treatment, to form an image forming layer forming coating. A solution is prepared and applied on a support by extrusion coating, followed by drying, and then surface treatment with a calendar.
1.2 μm thickness by curing at ℃ for 72 hours
To form a thermosetting image forming layer.

Co-deposited-FeOx powder 100 parts [Hc = 750 oersted, BET = 45 m ^{2 /} g, x = 1.417] Vinyl chloride resin [manufactured by Nippon Zeon Co., Ltd., MR-110] 10 parts Polyurethane resin [Toyobo Co., Ltd., UR-8700] 10 parts α-alumina [average particle size = 0.15 μm] 8.0 parts Carbon black [average particle size = 0.04 μm] 0.5 part Stearic acid 1.0 Parts Butyl stearate 1.0 parts Polyisocyanate compound 5.0 parts [Nippon Polyurethane Industry Co., Ltd., Coronate 3041] Thermal diffusible dye 1 1.1 parts [Sand, Foron Brilliant Yellow S-6GL] Thermal diffusion Sexual Dye 2 1.7 parts [MS Red G manufactured by Mitsui Toatsu Co., Ltd.] Thermal Diffusion Dye 3 1.1 parts [Made by Bayern, Macr lex Red Violet R] Thermal diffusible dye 4 3.3 parts [MS Cyan VPG manufactured by Mitsui Toatsu Co., Ltd.] Cyclohexanone 100 parts Methyl ethyl ketone 100 parts Toluene 100 parts Separately, a 25 μm double-sided transparent treatment as a release sheet. Using a polyethylene terephthalate film [T600E manufactured by Diafoil Hoechst Co., Ltd.], an adhesive layer forming coating solution having the following composition was applied and dried on this release sheet to form an adhesive layer having a thickness of 15.0 μm. Then, the adhesive layer surface of the release sheet with the adhesive layer and the surface of the above-mentioned image forming layer are opposed to each other, and bubbles are formed by a heating and pressure roll [temperature; 40 ° C., conveying speed; 30 mm / sec, pressure; 2.0 kg / cm]. A heat-pressurization treatment was performed so as not to enter, and an image recording material in which release sheets were laminated was prepared.

Ethylene-ethyl acrylate copolymer 20 parts [Eva flex-EEA A709 manufactured by Mitsui DuPont Polychemical Co., Ltd.] Toluene 80 parts 3) Transparent polyethylene having a 100 μm thick image forming layer laminated surface subjected to corona discharge treatment The following composition 1 was kneaded and dispersed on a terephthalate film [T60 manufactured by Toray Industries, Inc.] using an open kneader to prepare an image forming layer forming coating solution, which was applied onto a support by extrusion coating. After that, it is dried and then surface treated with a calendar.
By curing for 72 hours at 0 ° C, the thickness is 0.9μ
m thermosetting image forming layer 1 was formed. Next, the following composition 2 is mixed and dissolved to prepare an image forming layer forming coating solution containing a dye, which is applied on the image forming layer 1 by a wire bar coating method, and then the image forming layer having a thickness of 0.40 μm. Was formed.

—Composition 1— Fe—Al based ferromagnetic metal powder 100 parts [Fe: Al atomic number ratio = 100: 6 (whole), Fe: Al atomic number ratio = 50: 90 (surface), average major axis Diameter: 0.15 μm, Hc: 1700 oersted, σs: 115 emu / g, BET: 53 m ² / g] Vinyl chloride resin [manufactured by Nippon Zeon Co., Ltd., MR-110] 10 parts Polyurethane resin [Toyobo Co., Ltd. ), UR-8700] 10 parts α-alumina [average particle size = 0.15 μm] 8 parts Carbon black [average particle size = 0.04 μm] 0.5 part Stearic acid 1 part Butyl stearate 1 part Polyisocyanate compound 5 parts [Japan Polyurethane Industry Co., Ltd., Coronate 3041] Cyclohexanone 100 parts Methyl ethyl ketone 100 parts Toluene 100 parts-Composition 2-Heat Diffusible dye 1 1.5 parts [Sand, Foron Brilliant Yellow S-6GL] Thermal diffusible dye 2 2.4 parts [Mitsui Toatsu Co., Ltd. MS Red G] Thermal diffusible dye 3 1.5 Part [Made by Bayern, Macrolex Red Violet R] Thermally diffusible dye 4 4.6 parts [Mitsui Toatsu Co., Ltd., MS Cyan VPG] Polyvinyl acetal resin 10 parts [Sekisui Chemical Co., Ltd., S-REC KS -5Z] Methyl ethyl ketone 100 parts Toluene 100 parts Cyclohexanone 20 parts Separately, as a release sheet, a transparent polyethylene terephthalate film [T100E] manufactured by Diafoil Hoechst Co., Ltd., which has been subjected to one-side easy contact with 25 μm, was used, and the easy-adhesion layer surface of this release sheet was used. A coating liquid for forming an adhesive layer having the following composition was applied to the above and dried to give a thickness of 15. To form an adhesive layer of [mu] m. Then, the adhesive layer side of the release sheet with the adhesive layer and the surface of the above-mentioned image forming layer are made to face each other, and a heating and pressing roll [temperature: 25 ° C.,
A conveyance speed: 40 mm / sec, a pressure of 3.0 kg / cm] was applied to heat and pressure so as to prevent bubbles from entering, to prepare an image forming material in which a release sheet was laminated.

Ethylene-vinyl acetate copolymer 15 parts [Evaflex-EV150 manufactured by Mitsui DuPont Polychemical Co., Ltd.] Toluene 85 parts <Image forming method> 1) Using the above-mentioned image recording material 1), a semiconductor laser Using [Sharp LT090MD, main wavelength 830 nm], focusing on the interface between the support and the image forming layer, the energy at the interface was 300 mJ / cm ² at a spot diameter of 6 μm × 6 μm from the support side. The number of pixels is 256 by scanning exposure, and the pixel size is 96
100 μm x 96 μm images vertically and horizontally (10 in total)
Image exposure. Then, the surface of the image forming layer of the image recording material and an adhesive tape [Scotch No.
845 [book tape] and the adhesive layer surface of the tape are faced to each other so that air bubbles do not enter [pressure roll, conveying speed;
30 mm / sec, pressure 3.0 kg / cm]
By fixing the image forming material on a flat plate and peeling off the adhesive tape [peeling angle 90 degrees, peeling speed 40 mm / sec], the part where the binding force has decreased is transferred to the adhesive tape side by image exposure with high density energy light. Then, the image was formed.

After that, the image-formed image recording material
Heat and pressure treatment with a heat roll through a 5 μm release sheet [temperature; 120 ° C., transport speed; 30 mm / sec, pressure 2.0 kg / cm] to obtain density gradation from a recording medium having binary image density. An image recording body having the above was prepared. The transmission image density (measured transmission density-support transmission density) of the image recording material thus formed was measured before and after the heat and pressure treatment,
The results are shown in FIG. In the figure, B represents the density according to the number of exposed pixels of the image recording body before the heat and pressure treatment, and B '
Represents the concentration corresponding to B after the heat and pressure treatment. Further, A represents the visual density, and here, the distinguishable density step according to the Weber-Hifner law is defined as the distinguishable ratio ΔOD / O.
D is 0.01 and the initial concentration is 0.274.

2) Using the image recording material 2) described above, imagewise exposure was carried out in the same manner as in the method 1) for producing the image recording material described above. Next, the support side of the image recording material is fixed to a flat plate, and the release sheet is peeled off (peeling angle 180 °, peeling speed 3
(0 mm / sec) to transfer the part where the binding force was reduced due to image exposure to the release sheet side to form an image.

After that, a transfer foil [HC-K2-AS foil manufactured by Oike Sangyo Co., Ltd.] was used as a protective layer, the image-recorded image-formed material was made to face the adhesive layer side of the transfer foil, and a heat roll was used. Heat and pressure treatment at [temperature; 120 ° C, transport speed;
The resin layer was transferred to the image forming layer surface at a pressure of 30 mm / sec and a pressure of 2.0 kg / cm] to prepare an image recording body having a density gradation from a recording body having a binary image density. The transmission image density (measured transmission density-support transmission density) of the image recording material thus formed was measured before and after the heat and pressure treatment,
The results are shown in FIG. In the figure, C represents the density according to the number of exposed pixels of the image recording body before the heating and pressurizing process, and C '
Represents the concentration corresponding to C after the heat and pressure treatment. Further, A represents the visual density, and here, the distinguishable density step according to the Weber-Hifner law is defined as the distinguishable ratio ΔOD / O.
D is 0.01 and the initial concentration is 0.274.

3) Using the image recording material 3) described above, imagewise exposure was carried out in the same manner as in the method 1) for preparing the image recording material described above. Next, the support side of the image recording material is fixed to a flat plate, and the release sheet is peeled off (peeling angle 180 °, peeling speed 3
(0 mm / sec) to transfer the part where the binding force was reduced due to image exposure to the release sheet side to form an image.

Thereafter, using a laminate sheet [Ester film E1532 manufactured by Toyobo Co., Ltd.] as a protective layer, the image-formed image recording material is faced to the adhesive layer side of the sheet, and heated and pressed by a heat roll. [Temperature; 1
20 ° C, transport speed; 40 mm / sec, pressure 1.5 kg / c
m] to attach the laminate sheet to the image forming layer surface,
An image recording body having a density gradation was prepared from a recording body having a binary image density. Transmission image density of the image recording material formed in this way (measured transmission density-support transmission density)
Was measured before and after the heat and pressure treatment, and the results are shown in FIG. In the figure, D represents the density according to the number of exposed pixels of the image recording body before the heat and pressure treatment, and D ′ represents the density corresponding to B after the heat and pressure treatment. Further, A represents the visual density, and the distinguishable density step according to the Weber-Hifner rule is also shown here with the distinguishable ratio ΔOD / OD = 0.01 and the initial density 0.274.

[0074]

By the image forming material of the present invention and the image forming method of the present invention, an image recording body having density gradation can be obtained by imparting gradation to an image having binary image density.

[Brief description of the drawings]

FIG. 1 is a diagram showing an image forming material.

FIG. 2 is a conceptual diagram showing a state of an image forming layer by image exposure.

FIG. 3 is a diagram showing an image recording body using the image forming material of FIG. 1 at a stage of recording with binary image density.

FIG. 4 is a diagram showing a state in which density gradation is added to the image of FIG.

FIG. 5 is a diagram showing an image forming material in which an adhesive sheet is pasted together.

FIG. 6 is a diagram showing an image recording material having an image forming layer in which a layer containing a dye and a layer containing a colorant are laminated.

FIG. 7 is a diagram showing a state in which an image having binary image densities is formed from the image forming materials shown in FIGS. 5A and 6B.

[Fig. 8] Protective layer transfer material (transfer foil, laminate sheet)
FIG.

FIG. 9 is a diagram showing a state in which a protective layer is transferred to provide gradation.

FIG. 10 is a diagram showing the density of an image recording body formed by the method of claim 2 according to the number of exposed pixels.

FIG. 11 is a diagram showing the density according to the number of exposed pixels of the image recording body formed by using the transfer foil protective layer in the method of claim 3.

FIG. 12 is a diagram showing the density according to the number of exposed pixels of the image recording body formed by using the laminate sheet protective layer according to the method of claim 3.

[Explanation of symbols]

 1 Support 2 Image forming layer containing colorant 2a Image forming layer in non-exposed area 2b Image forming layer in exposed area 3 Intermediate layer 4 Adhesive sheet 5 Adhesive sheet support 6 Adhesive layer or adhesive layer 7 Contains dye Layer 7a Dye-containing layer in non-exposed area 7b Dye-containing layer in exposed area 8 Release layer 9 Protective layer 10 Transfer foil support 11 Laminate sheet support

Claims (7)

[Claims] 1. An image forming material having an image forming layer is formed on a support to form an image having binary image densities, and then the image is provided with gradation of density by heating and / or pressurizing. An image forming method characterized by the above. 2. The image forming method according to claim 1, wherein a dye is contained in a high density area of the image having the binary image density. 3. The image formation according to claim 2, wherein a protective layer is transferred to the surface on which the image is formed by heating and / or pressurizing to give a density gradation to the image. Method. 4. An image having the binary image density is formed by exposing the exposed portion of the image forming layer to a support by exposure with high-density energy light and removing the exposed portion. The image forming method according to claim 1, 2 or 3, wherein the image forming method is performed. 5. An image recording body, on which an image having a density gradation is formed by the method according to any one of claims 1 to 4. 6. An image recording material having an image forming layer containing a non-diffusible colorant and a diffusible dye on a support. 7. The image forming layer comprises a plurality of layers,
The image recording material according to claim 6, wherein a dye is contained in an image forming layer other than the image forming layer closest to the support.