JP2000127622A - Image forming material, its production, and image forming method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming material which is effective to obtain an image having high sensitivity, high resolution, and no residual color, to prevent the generation of pinholes, and to protect a coating film from scratching, a method for producing the material, and a method for forming the image using the material. SOLUTION: An image forming material has an image forming layer, placed on a support, containing coloring agent particles, a polyurethane 30-150 deg.C in Tg (glass transition temperature), carbon black 50-500 nm in particle size, and a lubricant. The material is applied with the use of a coating solution 0.9-0.97 in specific gravity at 20 deg.C and image-exposed to scanning laser beams.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image-forming material having high sensitivity, sufficient density, high resolution, no residual color, a coating which is hardly damaged and improved pinhole generation, and a method for producing the same. And an image forming method using the same.

[0002]

2. Description of the Related Art Hitherto, there has been known a recording method in which a recording material is irradiated with high-density energy light such as a laser beam so that a part of the material is melted, deformed, scattered, burned, or evaporated. These are dry treatments that do not require treatment liquids such as chemicals, and have the advantage that high contrast can be obtained by melting, dispersing, or evaporating and removing only the light irradiation part. Optical recording materials, and image forming materials that make themselves visible images.

[0003] For example, Japanese Patent Application Laid-Open Nos.
JP-A-105638 and JP-A-62-115153 disclose a method of forming a resist pattern by photodecomposing a binder resin by pattern exposure and a material therefor.
Nos. 5-132536, 57-27788 and 57-
No. 103137 describes that an inorganic compound thin film provided by a vapor deposition method is exposed to light and the information is recorded by melting deformation of the film.
No. 87, No. 6-40163 and the like, a material for information recording by removing a colored binder layer by photothermal conversion,
U.S. Pat. No. 4,245,003 and the like each disclose an image forming material having an image forming layer containing graphite or carbon black.

Japanese Patent Application Laid-Open No. Hei 9-15849 discloses an image forming layer containing colorant particles and a binder, and has a transmission density at a wavelength λ _max at which the transmission density is maximum in a spectral absorption wavelength range of 350 to 1200 nm. Is per 3 μm of film thickness.
An image forming material having a value of 0 or more is disclosed. Although this technique has made it possible to obtain high sensitivity and a sufficient density, it is still necessary to improve the residual color and the strength of the coating film. Further, in the step of applying the image forming layer, there is a problem that a pinhole presumably caused by contact with the transport roll occurs. In particular, the frequency of occurrence of pinholes increases as the thickness of the support increases, which is particularly remarkable when a support having a thickness of 150 μm or more is used.

In order to eliminate the occurrence of pinholes, it has been effective to increase the strength of the coating film by adding a large amount of an abrasive such as α-alumina to the image forming layer. There were problems that the removal of the image forming layer was poor, a low-density image with a low density was not obtained, and the resolution was insufficient and the sensitivity was low. In addition, vinyl chloride resins have been used from the viewpoint of good dispersibility as a binder and excellent coating film strength, but there is a possibility of generating hydrogen chloride gas and dioxin, so there is an environmental problem, We needed to find an alternative resin.

In order to improve the sensitivity, it is effective to make the image forming layer thinner, but there is a problem that coating unevenness is apt to occur. In order to improve coating unevenness, it is effective to dilute the specific gravity of the coating solution to a range of 0.9 to 0.97 to increase the wet film thickness. However, when a coating solution containing a lubricant is diluted and applied, there arises a problem that residual color, sensitivity, and resolution are deteriorated.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to obtain a high-resolution image with high sensitivity and no residual color, and to reduce the occurrence of pinholes. It is another object of the present invention to provide an image forming material in which a coating film is hardly damaged, a method for producing the same, and an image forming method using the same.

[0008]

The present inventors have studied various means for improving the above-mentioned problems, and as a result, have found that a lubricant, carbon black having a particle size of 50 to 500 nm, and a Tg of 30 are obtained.
It has been found that the problem can be solved by using a combination of polyurethane at 150 ° C. and the present invention has been accomplished. That is, the above object of the present invention has been achieved by the following constitutions.

(1) An image having, on a support, an image forming layer containing colorant particles, polyurethane having a Tg (glass transition point) of 30 to 150 ° C., carbon black having a particle size of 50 to 500 nm, and a lubricant. Forming material.

(2) The image forming material according to (1), wherein the carbon black has a DBP oil absorption of 20 to 100 cc / 100 g.

(3) The image forming material according to (1) or (2), wherein the lubricant is at least one selected from fatty acids and fatty acid esters.

(4) The image forming material according to (1), (2) or (3), wherein the colorant particles are metal atom-containing particles.

(5) A method for producing an image forming material, wherein the image forming material according to (1) is applied at 20 ° C. using a coating solution having a specific gravity of 0.9 to 0.97.

(6) The method for producing an image-forming material according to (5), wherein the material is ultrasonically dispersed before coating.

(7) An image forming method, wherein the image forming material according to (1) is scanned with a laser beam to perform image exposure.

Hereinafter, the present invention will be described in more detail.

<Image-forming Material> The image-forming material of the present invention comprises an image-forming layer provided on a support, the layer comprising colorant particles, polyurethane having a Tg (glass transition point) of 30 to 150 ° C. It contains carbon black having a diameter of 50 to 500 nm and a lubricant.

As the support, acrylates, methacrylates, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, nylon, aromatic polyamide, polyether Resin films of ether ketone, polysulfone, polyethersulfone, polyimide, polyetherimide, etc., and further, resin films obtained by laminating two or more layers of the above resins can be exemplified.

The support is preferably stretched into a film and heat-set in view of dimensional stability. Further, when the image forming method described later is carried out, image exposure is performed from the support side with high-density energy light. In this case, the transmittance for the wavelength of the energy light is preferably 50% or more, and more preferably 70% or more. Further, a filler such as titanium oxide, zinc oxide, barium sulfate, calcium carbonate, etc., a coloring agent, an antistatic agent and the like may be added as long as the effects of the present invention are not impaired. The thickness of the support is 10 to 5
It is about 00 μm, preferably 25 to 250 μm.

As the colorant particles contained in the image forming layer, known colorant particles having absorption in a known wavelength range of 350 to 1200 nm can be appropriately selected and used.
Only one colorant particle may be used, or a plurality of colorant particles may be used in combination. Further, when an image is formed by an image forming method in which the bonding force with a support is reduced by high-density energy light described later, 600 to 120 as colorant particles.
It is preferable to include at least one compound having absorption in the wavelength region of 0 nm (hereinafter, referred to as a photothermal conversion compound).

As such a photothermal conversion compound, an organic compound and / or an inorganic compound can be appropriately selected and used. As the organic compound, for example, 600 to 1200 n
dyes and dyes dispersed in the image forming layer having absorption in the wavelength range of m. Specific examples include cyanine dyes, rhodocyanine dyes, oxonol dyes, carbocyanine dyes, and dicarbocyanine dyes. And tricarbocyanine dyes, tetracarbocyanine dyes, pentacarbocyanine dyes, styryl dyes, pyrylium dyes, and metal-containing dyes such as metal phthalocyanines and metalloporphyrins. Rev .. 92, 1197 (1
992) and the like. or,
Inorganic compounds having an absorption in the wavelength range of 600 to 1200 nm include graphite, carbon black, iron, nickel, zinc, titanium, aluminum, molybdenum, tungsten, copper, lead, tin and other metal powder particles, iron-aluminum, Powder particles of alloys such as iron-cobalt and lead-tin; metal oxide powder particles such as cobalt trioxide, iron oxide, chromium oxide, copper oxide, and titanium black; metal nitride powder such as niobium nitride; tantalum carbide Metal carbide powder, metal sulfide powder, etc., and various magnetic powder particles used for magnetic paints and the like can also be suitably used in the present invention.

Organic compounds and / or inorganic compounds can be used in the same manner as the photothermal conversion compounds, in addition to the compounds having absorption in the wavelength range of 600 to 1200 nm. Pigments, dyes or organic pigments, and as the inorganic compound, conventionally known inorganic pigments, metal powder particles, metal oxide powder particles, metal nitride powder, metal carbide powder, metal sulfide powder, etc. Examples include inorganic metal particles.

The above-mentioned colorant particles are present in the image forming layer in a state where the colorant particles are present in a uniform dispersion state in the layer, and the colorant particles themselves are not porous. This is preferable because an image having a low residual ratio of the image forming layer to be removed when an image is formed by high-density energy light can be obtained.

As such a non-porous compound also serving as a light-to-heat conversion compound, metal atom-containing particles are preferable from the viewpoint of the stability of the particles themselves. For example, metal-containing dyes such as metal phthalocyanine and metal porphyrin, inorganic metal particles, etc. Can be mentioned. Among them, inorganic metal particles having relatively uniform particle size and shape are more preferable from the viewpoint of resolution. As such inorganic metal particles, for example, one kind or two or more kinds such as a simple metal and an alloy Inorganic metal compounds such as metal particles consisting only of the above-mentioned metals or oxides, nitrides or carbides thereof are preferably used.

In the present invention, a metal refers to an inorganic compound composed of one kind of metal atom, an alloy is an inorganic compound composed of two or more kinds of metal atoms, and an inorganic metal compound is composed of a metal atom and an atom other than the metal. Inorganic compounds. Among these, various magnetic powder particles can be preferably used. When using magnetic powder particles, ferromagnetic iron oxide powder particles, ferromagnetic metal powder particles, cubic plate-like powder particles and the like can be appropriately selected and used, among which ferromagnetic iron oxide powder particles,
Ferromagnetic metal powder particles can be suitably used.

The content of the colorant particles is about 70 to 99% by weight, preferably 75 to 95% by weight of the components for forming the image forming layer.

The Tg contained in the image forming layer is 30 to 15
Polyurethane at 0 ° C is used as a binder, and the Tg is preferably 40 to 150 ° C, more preferably 50 to 130 ° C, and still more preferably 60 to 110 ° C.

The polyurethane can be synthesized by reacting a polyol with a polyisocyanate. Specifically, the polyurethane is synthesized by using a polyester polyol obtained by reacting a polyol with a polybasic acid as a raw material. I do. Examples of the polyisocyanate include diphenylmethane-4,4'-diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,5-naphthalenedi isocyanate, lysine isocyanate methyl ester and the like. Can be mentioned. A commercially available product such as the Byron UR series (Toyobo Co., Ltd.) may be used.

Further, a binder other than polyurethane may be used in combination as long as the effects of the present invention are not impaired. Examples of such a binder include vinyl chloride resins such as polyester and vinyl chloride copolymer. These resins (polyurethane, including the present invention) is -SO ₃ M, -O
SO ₃ M, —COOM and —PO (OM ₁ ) ₂ [where
M represents a hydrogen atom or an alkali metal, and M ₁ represents a hydrogen atom, an alkali metal or an alkyl group. It is preferable to include a repeating unit having at least one type of polar group selected from the above], and by using a resin into which such a polar group is introduced, the dispersibility of the colorant particles can be improved. The content of the polar group in each resin is 0.1 to
It is about 8.0 mol%, preferably 0.2 to 6.0 mol%.

As another binder, vinyl chloride
Vinyl chloride resins such as vinyl acetate copolymer, polyolefin resins such as butadiene-acrylonitrile copolymer, polyvinyl acetal resins such as polyvinyl butyral, cellulose resins such as nitrocellulose, and styrene such as styrene-butadiene copolymer. A resin, an acrylic resin such as polymethyl methacrylate, a polyamide, a phenol resin, an epoxy resin, a phenoxy resin, or the like may be used in combination.

When these binders are used in combination with the polyurethane of the present invention, 10 to 10 parts of the polyurethane of the present invention are used.
Up to 30% by weight is preferred.

The particle size of the carbon black contained in the image forming layer needs to be 50 to 500 nm, preferably 55 to 450 nm, more preferably 55 to 400 nm.
nm, more preferably 60 to 350 nm.

The particle size of carbon black can be directly measured visually with an electron microscope. By adding these carbon blacks, the absorbance per unit film thickness is increased, and the residual ratio of the image forming layer in the portion where the exposed portion has been removed when the image is exposed with high-density energy light can be reduced. . Further, the antistatic effect can be given to the image forming layer, and adhesion of dust or the like which causes image failure can be prevented.

If the particle size of carbon black is less than 50 nm or more than 500 nm, the effect of the present invention cannot be sufficiently obtained.

In the present invention, the carbon black DB
The P oil absorption is preferably in the range of 20 to 100 ml / 100 g from the viewpoint of maintaining dispersibility. Here, the DBP oil absorption refers to the number of ml of DBP added when dibutyl phthalate (DBP) is added little by little to 100 g of the pigment powder, the state of the pigment is observed while kneading, and the dispersion is dispersed to form one lump. I do.

The method of adding carbon black can be changed in various ways. For example, carbon black fine particles and coarse particles may be simultaneously charged into a disperser and mixed, or only a part of the fine particles may be charged first and the remaining amount may be charged at a point where dispersion has progressed to some extent. Good. When emphasis is placed on the dispersibility of carbon black, carbon black can be kneaded with other components using a three-roll mill, Banbury mixer, or the like, and then dispersed using a disperser to form a coating material. Further, a so-called carbon master batch in which carbon black is kneaded with a binder in advance may be used.

As the lubricant contained in the image forming layer,
Examples include fatty acids, fatty acid esters, fatty acid amides, (modified) silicone oils, (modified) silicone resins, fluororesins, and carbon fluorides. Among these,
Fatty acids having 12 or more carbon atoms, fatty acid esters, and fatty acid amides are preferred.

The image forming layer may contain additives such as a durability improver, a dispersant, an antistatic agent, a filler, a filler and a curing agent as long as the effects of the present invention are not impaired.

Examples of the durability improver include polyisocyanate and the like.
No. 14218, "0093" and the like. Examples of the antistatic agent include cationic surfactants, anionic surfactants, nonionic surfactants, polymer antistatic agents, and conductive agents. In addition to the fine particles and the like, compounds described in "11290 Chemical Products", Chemical Daily, pp. 875-876 and the like can be mentioned. As the filler, carbon black, graphite, TiO ₂ , Ba
SO ₄ , ZnS, MgCO ₃ , CaCO ₃ , ZnO, Ca
O, WS ₂ , MoS ₂ , MgO, SnO ₂ , Al ₂ O ₃ , α
—Fe ₂ O ₃ , α-FeOOH, SiC, CeO ₂ , B
N, SiN, MoC, BC, WC, titanium carbide,
Corundum, artificial diamond, gypsum, garnet,
Examples include inorganic fillers such as silica stone, triboli, diatomaceous earth, and dolomite, and organic fillers such as polyethylene resin particles, fluorine resin particles, guanamine resin particles, acrylic resin particles, silicon resin particles, and melamine resin particles.

The curing agent can be used without any particular limitation as long as it can cure the image forming layer. Such a curing agent is used, for example, when synthesizing the polyurethane in the binder described above. Polyisocyanate and the like. By hardening the image forming layer by adding such a curing agent, not only the durability of the formed image is improved, but also the residual color of the image forming layer portion removed by the image forming method described later is eliminated. Can be.

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

The thickness of the image forming layer is 0.1 to 5.0 μm
Degree, preferably in the range of 0.1 to 2.0 μm, particularly preferably 0.1 to 1.0 μm, and more preferably 0.2 to 1.0 μm.
0 μm. Within this range, in the image forming method described later, an image can be formed with irradiation of low-energy high-density energy light, in other words, with high sensitivity. Further, the image forming layer may be formed as a single layer, or may be composed of multiple layers having the same or different compositions. When the image forming layer is composed of multiple layers, the image forming layer near the support may contain a photothermal conversion compound. It is preferable in terms of sensitivity.

The image-forming material of the present invention may be used in accordance with individual purposes when antistatic, transporting, or blocking prevention is required on the back surface of the support in addition to the above-mentioned support and image forming layer. It is preferable to provide a backing layer, which may be coated with a commercially available backing layer-forming composition, or may be provided in advance on a support, and when newly provided, a known backing layer according to various purposes may be appropriately provided. It can be provided selectively.

Further, as long as the effects of the present invention are not impaired,
When the bonding force between the support and the image forming layer, the coating property of the image forming layer provided by coating or the antistatic property of the image forming material, etc. are required, it is preferable to provide an intermediate layer or the like according to each purpose, Known intermediate layers for various purposes can be appropriately selected and provided.

The thickness of such an intermediate layer or backing layer is as follows:
The thickness is about 0.05 to 10 μm, preferably 0.1 to 5 μm.

In the image forming method of the present invention described below,
A release layer provided for transferring an image by peeling after image exposure is used as a release layer by forming a layer with a resin having self-supporting property or using a resin film used as a support as described above as a release layer. . An adhesive layer may be provided between the release layer and the image forming layer.

Such an adhesive layer may be any of those which have adhesiveness at room temperature themselves, and those which exhibit adhesiveness by applying heat or pressure. Examples thereof include a resin having a low softening point, an adhesive agent, It can be formed by appropriately selecting a solvent.

Examples of the resin having a low softening point include ethylene copolymers such as ethylene-vinyl acetate and ethylene-ethyl acrylate; polystyrene resins such as styrene-butadiene, styrene-isoprene and styrene-ethylene-butylene; polyester resins; Polyolefin resins such as polyethylene and polypropylene; polyvinyl ether resins; acrylic resins such as polybutyl methacrylate;
Ionomer resins; cellulosic resins; epoxy resins; vinyl chloride resins such as vinyl chloride-vinyl acetate copolymers, and the like. Examples of the adhesion-imparting agent include rosin, hydrogenated rosin, rosin maleic acid, polymerized rosin and Unmodified or modified products such as rosin phenol, terpenes, petroleum resins and modified products thereof, and the like. Examples of the heat solvent include compounds that are solid at ordinary temperature and reversibly liquefy or soften when heated, and specifically, terpineol,
Menthol, acetamide, benzamide, coumarin,
Monomolecular compounds such as benzyl cinnamate, diphenyl ether, crown ether, camphor, p-methylacetophenone, vanillin, dimethoxybenzaldehyde, p-benzylbifevir, stilbene, margaric acid, eicosanol, cetyl palmitate, stearamide, behenylamine; Waxes such as beeswax, candelilla wax, paraffin wax, ester wax, montan wax, carnauba wax, amide wax, polyethylene wax, microcrystalline wax; rosin derivatives such as ester gum, rosin maleic resin, rosin phenol resin; phenolic resin , Ketone resin,
Examples include epoxy resins, diallyl phthalate resins, terpene-based hydrocarbon resins, cyclopentadiene resins, polyolefin-based resins, polycaprolactone-based resins, and polymer compounds represented by polyolefin oxides such as polyethylene glycol and polypropylene glycol.

The thickness of the release layer is about 0.1 to 100 μm,
The thickness is 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.

In the present invention, an antistatic agent is added to any one of the above-mentioned support, image forming layer, backing layer, intermediate layer, release layer and adhesive layer for the purpose of preventing blocking and adhesion of dust. Is preferred. Such an antistatic agent is
Those added to the image forming layer can be appropriately selected and used.

The image forming layer includes, for example, colorant particles, a binder, carbon black, a lubricant, and if necessary, a durability improver, a dispersant, an antistatic agent, a filler, a filler,
Kneading the curing agent etc. and the solvent to prepare a high concentration paint,
Next, the high-concentration paint is diluted to form a coating solution, which is formed by coating and drying on a support.
It is preferable to adjust the specific gravity of the coating solution to 0.9 to 0.97 at 20 ° C. By adjusting the specific gravity of the coating solution to this range, an effect of improving coating unevenness can be obtained.

It is a further preferred embodiment that the coating solution is ultrasonically dispersed before the coating because the dispersibility and the resolution are improved.

Examples of the solvent include alcohols (ethanol, propanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), aromatics (toluene, xylene, chlorobenzene, etc.), ketones (acetone, methyl ethyl ketone, etc.), Ester solvents (ethyl acetate,
Butyl acetate), ethers (such as tetrahydrofuran and dioxane), halogen solvents (such as chloroform and dichlorobenzene), and amide solvents (such as dimethylformamide and N-methylpyrrolidone). The kneading and dispersing of the components of the image forming layer include 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,
Sqegvari Attritor, High Speed Impeller Disperser, High Speed Stone Mill, High Speed Impact Mill, Disper,
A high-speed mixer, a homogenizer, an ultrasonic disperser, an open kneader, a continuous kneader, or the like can be used.

The formation of the image forming layer on the support can be carried out, for example, by coating and drying with an extrusion-type extrusion coater. Depending on the orientation of the magnetic powder particles, a calendering treatment may be performed to make the surface properties of the image forming layer uniform. Alternatively, the magnetic powder particles may be randomly oriented by performing a non-orientation treatment. Through these processes, a high-resolution image can be obtained.

Further, when the content of the metal atom-containing particles is large in the image forming layer of the present invention, voids are easily formed in the image forming layer. In such a case, it is better to reduce the gap by applying pressure as necessary, such as a calendering process or a pressing process, if the image of the part where the exposed part was removed by image exposure with high-density energy light was removed. The residual ratio of the formation layer can be reduced.

<Image Forming Method> In the present invention, the image forming material having the image forming layer on the support is exposed from the support by image exposure with high-density energy light, and the image forming layer in the exposed portion is removed. An image is formed.

The image forming layer may consist of one layer,
It may be composed of a plurality of layers or more. When it is composed of two or more layers, for example, at least 600 to 1200n
On the photothermal conversion compound-containing layer having absorption at m,
Examples of the configuration include an image forming layer in which a colorant-containing layer having an absorption at 600 nm is laminated.

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 that can remove the exposed portion by any method. Among them, in order to obtain high resolution, electromagnetic waves whose energy application area can be narrowed down, particularly ultraviolet rays, visible rays, and infrared rays having a wavelength of 1 nm to 1 mm are preferable. As a light source to which such high-density energy light can be applied, , For example a laser,
Examples include a light-emitting diode, a xenon flash lamp, a halogen lamp, a carbon arc lamp, a metal halide lamp, a tungsten lamp, a quartz mercury lamp, and a high-pressure mercury lamp. The energy applied at this time can be appropriately selected by adjusting the exposure distance, time, and intensity according to the type of the image forming material.

When the high-density energy light is subjected to batch exposure, a mask material in which a negative pattern of a desired exposure image is 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 subjected to exposure control using an optical shutter material such as a liquid crystal or PLZT, an image signal is used. It is possible to carry out the corresponding digital exposure. 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 laser light is used as a light source,
It is possible to form a latent image by scanning light according to image data by squeezing light into a beam, and furthermore, by using a laser as a light source, it is easy to narrow the exposure area to a very small size, and it is possible to form a high-resolution image Formation is possible.

As the laser light source used in the present invention, generally well-known ruby laser, YAG
Laser, glass laser and other solid lasers; He-N
Gas lasers such as e laser, Ar ion laser, Kr ion laser, CO ₂ laser, CO laser, He-Cd laser, N ₂ laser, excimer laser; InGaP laser, AlGaAs laser, Ga
Semiconductor lasers such as an AsP laser, an InGaAs laser, an InAsP laser, a CdSnP ₂ laser, and a GaSb laser; chemical lasers, dye lasers and the like; It is preferable to use a laser having a wavelength of 600 to 1200 nm in terms of sensitivity since light energy can be efficiently converted to heat energy. Further, among them, a laser of 750 to 1200 nm can efficiently convert light energy into heat energy.
It is more preferable in terms of sensitivity, and among them, it is particularly preferable to use a high illuminance laser as long as the laser has the same wavelength.

In the present invention, image formation is performed by exposing the image forming layer to high-density energy light and then exposing the exposed portion by any method. If the light exposure energy is sufficient to completely destroy and scatter the image forming layer, it can be removed by suctioning the scattered material, in which case it is adjacent to the image forming layer. By providing the suction portion at the portion where the heat is to be removed, the suction portion can be efficiently removed.

Further, when the exposure energy of the high-density energy light does not completely destroy the image forming layer, for example, when the bonding force between the support in the exposed area and the image forming layer is reduced, the above-mentioned case is adopted. In addition to the removal by suction, it can be removed by an image forming method described later.

Here, the decrease in the bonding force means that the image forming layer is completely scattered due to a physical or chemical change, the image forming layer is partially broken and / or scattered, and the surface of the image forming layer is broken. It does not include a phenomenon that a physical or chemical change occurs only in the vicinity of the support.

[0067]

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

Example 1 (Preparation of Image Forming Material) An image forming material of the present invention and a comparative example were prepared by using a support, an image forming layer, and a release layer shown below.

<Support> 1) A transparent polyethylene terephthalate film (T-100, manufactured by Diafoil Hoechst) having a thickness of 180 μm and both surfaces of which are anchor-coated.

2) A polyethylene terephthalate film (T-100: supra) in which one side having a thickness of 180 μm is subjected to an antistatic treatment and the image forming laminated surface is subjected to a corona discharge treatment. (Image forming layer) Image forming layers 1 to 8 of the present invention Comparative image forming layers 9 to 14 were prepared as follows.

1) The following composition was kneaded and dispersed using a kneader and a sand mill to prepare an image forming layer coating liquid (specific gravity: 0.94 / 20 ° C.) containing colorant particles. After applying on a support by extrusion coating, a magnetic field orientation treatment is performed while the coating is not dried, followed by drying and then calendering at 100 ° C. and a pressure of 300 kg / cm. Then, an image forming layer having a thickness of 0.6 μm was formed.

Fe—Al ferromagnetic metal powder (Fe: Al: Co: Y = 100: 10: 40: 8 (weight ratio), Hc: 2200 Oe, BET: 60 m ² / g, σs: 135 emu / g, average Long axis length: 0.6 μm, needle ratio: 5, crystallite size: 10 nm) 100 parts Polyester resin containing sodium sulfonate group (manufactured by Toyobo: Viron V28SS) 10 parts Polyurethane resin containing sodium sulfonate group (Toyobo) Company: Byron UR-8200) 10 parts Carbon black (Average particle size: 300 nm, DBP oil absorption 50 cc / 100 g) 1 part α-Alumina (Average particle size: 0.15 μm) 5 parts Stearic acid 1 part Butyl stearate 1 Part Polyisocyanate compound (Nippon Polyurethane Industry Co., Ltd .: Coronate L) 5 parts Cyclohexanone 400 parts In ethyl ketone 400 parts Toluene 400 parts 2) image forming layer 1), except omitting the ultrasonic dispersion after the image formation layer coating solution prepared in the same manner as 1) Thickness 0.
A 6 μm image forming layer was formed.

3) In the image forming layer 1), a polyurethane resin containing a sodium sulfonate group (Vylon UR-8)
An image forming layer was formed in the same manner as in 1) except that a sodium sulfonate group-containing polyurethane resin (Tg: 85 ° C.) was used instead of 200).

4) In the image forming layer 1), the carbon black has an average particle diameter of 100 nm and a DBP oil absorption of 80c.
An image forming layer was formed in the same manner as in 1), except that one copy of c / 100 g was used.

5) In the same manner as in 1) except that 5 parts of a polyisocyanate compound (manufactured by Nippon Polyurethane Industry Co., Ltd .: Coronate HX) was used in place of the polyisocyanate compound (Coronate L) in the image forming layer 1). Form an image forming layer.

6) An image forming layer was formed in the same manner as in 1) except that 100 parts of the following were used as the ferromagnetic metal powder in the image forming layer 1).

The Fe—Al ferromagnetic metal powder (Fe: Al:
Co: Y: Si = 100: 8: 30: 5: 2 (weight ratio), Hc: 2100 Oe, BET: 58 m ² / g, σ
s: 130 emu / g, average major axis length: 0.08 μm, needle ratio: 6, crystallite size: 11 nm) 7) In the image forming layer 1), except that 100 parts of the following were used as ferromagnetic metal powders Formed an image forming layer in the same manner as in 1).

Fe—Al ferromagnetic metal powder (Fe: Al:
Co: Y: Si = 100: 8: 20: 5: 2 (weight ratio), Hc: 2100 Oe, BET: 58 m ² / g, σ
s: 130 emu / g, average major axis length: 0.10 μm, needle ratio: 6, crystallite size: 14 nm) 8) In the image forming layer 1), except that 100 parts of the following were used as ferromagnetic metal powders Formed an image forming layer in the same manner as in 1).

Fe—Ni based ferromagnetic metal powder (Fe: Ni =
100: 10 (weight ratio), Hc: 1800 Oe, BE
T: 55 m ² / g, σs: 130 emu / g, average major axis length: 0.14 μm, acicular ratio: 8, crystallite size: 15 n
m) 9) Kneading the following composition using a kneader and a sand mill.
An image forming layer coating solution (specific gravity: 0.94 / 20 ° C.) containing dispersed colorant particles is prepared, subjected to ultrasonic dispersion, and then applied on a support by extrusion coating, followed by coating. Was subjected to a magnetic field orientation treatment while it was not dried, followed by drying and then calendering at 100 ° C. and a pressure of 300 kg / cm to form an image forming layer having a thickness of 0.6 μm.

Fe—Al ferromagnetic metal powder (Fe: Al: Co: Y = 100: 10: 40: 8 (weight ratio), Hc: 2200 Oe, BET: 60 m ² / g, σs: 135 emu / g, average Long axis length: 0.6 μm, needle ratio: 5, crystallite size: 10 nm) 100 parts Polyester resin containing sodium sulfonate group (supra: Byron V28SS) 10 parts Polyurethane resin containing sodium sulfonate group (supra: Byron) UR-8200) 10 parts α-alumina (average particle size: 0.15 μm) 5 parts Polyisocyanate compound (supra: Coronate L) 5 parts Cyclohexanone 400 parts Methyl ethyl ketone 400 parts Toluene 400 parts 10) In image forming layer 9) , Carbon black (average particle size: 300 nm, DBP oil absorption: 50 cc / 100)
g) Coating solution for image forming layer to which 1 part is added (specific gravity: 0.94)
/ 20 ° C.) to form an image forming layer in the same manner as described above.

11) An image was formed in the same manner as in the image forming layer 9) except that an image forming layer coating solution (specific gravity: 0.94 / 20 ° C.) was used in which 1 part of stearic acid and 1 part of butyl stearate were added. A formation layer was formed.

12) In the image forming layer 1), a polyurethane resin containing a sodium sulfonate group (UR-820)
An image forming layer was formed in the same manner as in 1) except that 10 parts of a vinyl chloride resin containing a potassium sulfonate group (manufactured by Zeon Corporation: MR110) was used instead of 0).

13) In the image forming layer 1), a polyurethane resin containing a sodium sulfonate group (Vylon UR-
8200), and an image forming layer was formed in the same manner as in 1) except that a sodium sulfonate group-containing polyurethane resin (manufactured by Toyobo Co., Ltd .: Byron UR-8700) was used.

14) In the image forming layer 1), carbon black (average particle diameter: 300 nm, DBP oil absorption: 50 cc)
/ 100 g) instead of carbon black (average particle size 40
An image forming layer was formed in the same manner as in 1), except that nm and the DBP oil absorption were 150 cc / 100 g).

<Release Layer> A 25 μm transparent polyethylene terephthalate film (S100, manufactured by Diafoil Hoechst) was used as a release layer, and an adhesive layer coating solution having the following composition was applied on the release layer and dried to obtain a thickness. An adhesive layer having a thickness of 4.0 μm was formed.

Ethylene-vinyl acetate copolymer (manufactured by DuPont Polychemicals, Mitsui: Evaflex EV410) 3.0 parts Silicone fine particles (manufactured by Toshiba Silicones: Tospearl 145) 0.6 parts Toluene 90 parts Cyclohexanone 6.4 parts Then, the surface of the adhesive layer of the release layer with the adhesive layer faces the surface of each of the image forming layers (1 to 14), and air bubbles are introduced using a pressure roll (conveyance speed: 30 mm / sec, pressure: 2.0 kg / cm). Pressure treatment so that the support (1 or 2)
Image forming materials 1 to 17 in which an image forming layer and a release layer were laminated in this order were produced.

(Image Forming Method) Using a semiconductor laser (LT090MD, manufactured by Sharp Corporation, main wavelength: 830 nm),
The image was exposed by focusing on the interface between the support and the image forming layer and performing scanning exposure from the support side. Next, the surface of the image forming layer and an adhesive tape (Scotch No.
845 book tape) with a pressure-sensitive treatment (pressure roll, conveyance speed: 3) so as to prevent bubbles from entering.
(0 mm / sec, pressure: 3.0 kg / cm) and adhere to each other. The image forming material is fixed on a flat plate, and the adhesive tape is peeled off (peeling angle: 90 °, peeling speed: 40 mm / sec). An image was formed by transferring the portion where the bonding strength was reduced by image exposure to the adhesive tape side.

The sensitivity of the image forming material, the resolution of the formed image, and the residual ratio of the portion where the image forming layer was transferred and removed were evaluated according to the following criteria.

<< Sensitivity >> 0.5 mm × 4 μm beam diameter
Solid scanning exposure such that a 0.5 mm image was formed was performed, and the average exposure amount (E: unit mJ / cm ² ) on the surface of the image forming material on which the image was formed was evaluated on a 5-point scale.

5 ... E≤100 4 ... 100 <E≤250 3 ... 250 <E≤400 2 ... 400 <E≤600 1 ... 600 <E.

<< Resolution >> Four-step evaluation based on the number (N) of resolvable lines per mm when an image is formed by scanning exposure at a beam diameter of 4 μm and a scanning pitch of 4 μm at an average exposure amount on the surface of the image forming material. did.

4 ... 125 = N 3 ... 120≤N <125 2 ... 110≤N <120 1 ... N <110.

<< Residual Density >> 5 mm × 5 at a beam diameter of 4 μm
mm, a solid scanning exposure is performed to form an image of mm, an image exposure is performed using high-density energy light, and the transmission density (OD = actual transmission density−
The transmission density of the support itself was evaluated in four steps using the visual density of a densitometer (X-rite 310TR, manufactured by X-rite).

4 ... OD ≦ 0.060 3 ... 0.060 <OD ≦ 0.100 2 ... 0.100 <OD ≦ 0.250 1 ... 0.250 <OD.

<< Pinhole >> The number of pinholes generated in the coating area of the image forming material of 1 m × 1 m was visually observed.

Table 1 summarizes the results.

[0097]

[Table 1]

From the results in Table 1, it is clear that the image forming material of the present invention is superior to the comparative image forming material in all items.

[0099]

According to the image forming material of the present invention, a high-resolution image having high sensitivity and no residual color can be formed. The image forming material was less likely to generate pinholes during coating, and the coating was hardly damaged.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B41M 5/26 YS

Claims (7)

[Claims] 1. A colorant particle, a polyurethane having a Tg (glass transition point) of 30 to 150 ° C., a particle size of 5
An image forming material having an image forming layer containing 0 to 500 nm of carbon black and a lubricant. 2. The carbon black has a DBP oil absorption of 20.
2. The image forming material according to claim 1, wherein the amount is from 100 to 100 cc / 100 g. 3. The image forming material according to claim 1, wherein the lubricant is at least one selected from fatty acids and fatty acid esters. 4. The image forming material according to claim 1, wherein the colorant particles are metal atom-containing particles. 5. A method for producing an image forming material, comprising applying the image forming material according to claim 1 at a specific gravity of 20 ° C. using a coating solution having a specific gravity of 0.9 to 0.97. 6. The method for producing an image forming material according to claim 5, wherein ultrasonic dispersion is performed before coating. 7. An image forming method, wherein the image forming material according to claim 1 is scanned with a laser beam to perform image exposure.