JP2002086939A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method causing no void of an image and being capable of forming an image of high resolution and an excellent image quality and forming a transferred image having an excellent color tone, without providing a cushion layer for a transfer material or an image receiving material. SOLUTION: In this image forming method, the transfer material having at least a substrate of a light-transmitting property, a conductive layer of the light-transmitting property, a photothermal conversion layer and a color material layer, and the image receiving material having at least a substrate, an image receiving layer and a conductive layer formed below the image receiving layer, are laid on each other so that the color material layer and the image receiving layer are opposed to each other. With a voltage impressed between the transfer material and the image receiving layer, a laser light is cast in the shape of the image from the side of the transfer material to transfer the color material layer of the transfer material onto the surface of the image receiving layer, and thereby the image is formed on the surface of the image receiving material.

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 forming a high-resolution image by transferring an image from a transfer material to a surface of an image receiving material using a laser beam.

[0002]

2. Description of the Related Art Conventionally, as a method of recording an image by thermal transfer, a method of directly applying pressure and heating to a thermal transfer material using a thermal head has been put to practical use. This method can be implemented with a low noise and simple device configuration,
It has excellent features such as maintenance-free and dry processing. In recent years, the density of the thermal head itself has been increasing, and even in this method, high resolution of an image can be achieved at a considerable level.

On the other hand, as an image recording method by thermal transfer capable of recording a higher-resolution image, a laser beam is irradiated to a transfer material, the laser beam is converted into heat in the transfer material, and the heat-sensitive recording is performed by the heat. Is known. In such a method, since the laser beam as an energy supply source can be focused to about several microns, it is possible to dramatically improve the resolution as compared with a method using a thermal head.

As a transfer material used in the laser thermal transfer recording method, a photothermal conversion layer that absorbs laser light to generate heat on a support, and a pigment is dispersed in components such as a heat-meltable wax and a binder. A hot-melt transfer material having such image forming layers in this order (Japanese Patent Application Laid-Open No. 5-58045) is known. In the case of using such a hot-melt transfer material, the heat generated in the laser light irradiation area of the light-to-heat conversion layer melts the image forming layer corresponding to the area, and is transferred onto the image receiving material stacked on the hot-melt transfer material. Then, a transfer image is formed on the image receiving material.

Japanese Patent Application Laid-Open No. 6-219052 discloses that a light-to-heat conversion layer containing a light-to-heat conversion substance, a very thin (0.03-0.3 μm) heat-peeling layer, and a coloring material are provided on a support. An image forming layer including the image forming layer is provided in this order, the transfer force between the image forming layer and the light-to-heat conversion layer, which are bonded by the interposition of the thermal release layer, is reduced by the transfer material using laser light irradiation. An image forming method for forming a high-definition image on an image receiving material laminated on the material is described. In this image forming method, a so-called "ablation" is used. Specifically, the thermal peeling layer partially decomposes and evaporates in a region irradiated with laser light, so that the image forming layer and the image forming layer in that region are decomposed. The bonding force with the light-to-heat conversion layer is weakened, and the image forming layer in that region is transferred onto the image receiving material laminated on the transfer material, and a transferred image is formed on the image receiving material.

An image forming method using a laser beam can use a printing paper sheet provided with an image receiving layer (adhesive layer) as an image receiving material, and can transfer a multicolor image by transferring images of different colors onto the image receiving material one after another. It has an advantage that an image can be easily obtained, and in particular, an image forming method using ablation has an advantage that a high-definition image can be easily obtained.

In these image forming methods by thermal transfer,
The adhesion between the transfer material and the image receiving material when transferring an image
Since the resolution of the image is greatly affected, the key to obtaining a high-resolution image is how to improve the adhesion between the two.

As a method for improving the adhesion between the transfer material and the image receiving material, there is disclosed a method in which a cushion layer having flexibility is provided on the transfer material and / or the image receiving material so as to absorb the unevenness of both. JP-A-5-169861).

However, when a cushion layer is provided on the image receiving material, it is difficult to use the image receiving material as a final recording medium, and it is necessary to transfer an image formed on the image receiving material to a final recording medium. There is a problem that a process is required and the process becomes complicated. Furthermore, even when a cushion layer is provided on the transfer material and the image receiving material is used as the final recording medium, the surface irregularities of the final recording medium may not be sufficiently absorbed by the cushion layer. There has been a demand for an image forming method capable of forming a high-resolution and high-quality image without securing adhesion to the image.

[0010]

Therefore, according to the present invention, even if a cushioning layer is not provided on a transfer material or an image receiving material, there is no image white spot, a high-resolution image having good image quality, and a transfer having a good color tone. An object is to provide an image forming method capable of forming an image.

[0011]

The above object can be attained by providing the following image forming method. (1) A transfer material having at least a light-transmissive support, a light-transmissive conductive layer, a light-to-heat conversion layer, and a colorant layer, and an image receiving apparatus having at least the support, an image-receiving layer, and a conductive layer formed below the image-receiving layer. The material is superimposed such that the color material layer and the image receiving layer face each other, and a voltage is applied between the transfer material and the image receiving material, and a laser beam is irradiated imagewise from the transfer material side to transfer the material. An image forming method comprising transferring a color material layer of a material to a surface of an image receiving layer to form an image on the surface of the image receiving material. (2) The image forming method according to (1), wherein the thickness of the support of the transfer material is 3 to 200 μm. (3) The thickness from the image receiving layer surface of the image receiving material to the conductive layer is 3
The image forming method according to the above (1) or (2), wherein the thickness is 0 μm or less. (4) The image forming method according to any one of (1) to (3), wherein the thickness is 20 to 30 μm. (5) The image formation as described in any one of (1) to (4) above, wherein the surface resistivity of each of the transfer material and the conductive layer of the image receiving material is 10 ¹¹ Ω / □ or less. Method. (6) The transfer material according to (1) to (1), wherein the transfer material is provided with at least a light-transmitting conductive layer, a light-to-heat conversion layer, and a coloring material layer in this order on a light-transmitting support. The image forming method according to any one of 5).

According to the image forming method of the present invention, even if a transfer material or an image receiving material is not provided with a cushion layer,
Using the power of the voltage applied between the transfer material and the image receiving material, the color material layer of the transfer material is transferred imagewise by laser light irradiation, and a high-resolution, high-quality image without white spots is obtained. It can be easily formed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The image forming method of the present invention relates to a transfer material having at least a light-transmitting support, a light-transmitting conductive layer, a light-to-heat conversion layer and a color material layer, and at least a support. With the body facing the image receiving layer side of the image receiving material having an image receiving layer and a conductive layer formed below the image receiving layer, and applying a voltage between the transfer material and the image receiving material, a laser beam is applied from the transfer material side. Irradiation is performed imagewise to transfer the color material layer of the transfer material to the surface of the image receiving layer, thereby forming an image on the surface of the image receiving material.

The image forming method of the present invention will be described with reference to FIG. In FIG. 1, reference numeral 10 denotes a transfer material in which a conductive layer 5, a light-to-heat conversion layer 4 and a color material layer 2 are sequentially laminated on a support 6, and 12 denotes a conductive layer 8 and an image receiving layer 7 on a support 9 in this order. It is a laminated image receiving material. Color material layer 2 of transfer material 10
Whether or not the surface on the side is in contact with the image receiving layer 7 side of the image receiving material 12;
Alternatively, a laminate for image formation is formed in a very close proximity.
The image receiving material 12 of the image forming laminate is placed on the surface of the support 9 in close contact with the surface of the recording drum. In this state, a voltage is applied between the transfer material and the image receiving material, and a laser beam is irradiated from the support 6 side of the transfer material to transfer the color material layer to the image receiving layer. By this method, a high-quality image without white spots can be obtained.

Hereinafter, the image forming method of the present invention will be described in detail for each component. 1. Transfer material [Light-transmissive support]
It may be simply referred to as “support”. )
There is no particular limitation as long as it has light transmittance, and various types of support materials can be employed according to the purpose. Preferred examples of the support material are transparent synthetic resin materials capable of transmitting laser light, and specifically, polyethylene terephthalate, polyethylene-2,6-naphthalate, polycarbonate, polyethylene, polyvinyl chloride, polyvinylidene chloride, and the like. Examples include synthetic resin materials such as polystyrene and styrene-acrylonitrile copolymer. Above all, biaxially stretched polyethylene terephthalate is preferable in consideration of mechanical strength and dimensional stability against heat.

The light-transmitting support of the transfer material may be subjected to a surface activation treatment and / or one or more layers, if necessary, in order to improve the adhesion to the layer provided thereon. An undercoat layer can be provided. Examples of the surface activation treatment include a glow discharge treatment and a corona discharge treatment. The material of the undercoat layer preferably has high adhesiveness to both surfaces of the support and the layer thereon, has low thermal conductivity, and has excellent heat resistance. Examples of such a material for the undercoat layer include styrene, styrene-butadiene copolymer, and gelatin. The thickness of the entire undercoat layer is usually 0.01 to 2
μm.

[Conductive layer] The conductive layer of the transfer material includes, for example, a layer composed of a conductive substance and a binder. As conductive materials, tin oxide, polyethylene glycol,
Examples thereof include carbon black, a surfactant, and an inorganic salt. Among them, antimony-doped tin oxide fine particles described in JP-A-61-20033 are preferably used. More preferably, JP-A-11-15109
And the like, such as acicular tin oxide fine particles described in Japanese Patent Application Publication No.
Further, as the binder, a binder described later in the description of the light-to-heat conversion layer is preferably used. The conductive layer is formed by applying and drying a coating solution prepared by using a suitable solvent for the conductive substance and the binder as described above. The thickness of the conductive layer is 0.01 to 2 μm, preferably 0.05 to 0.15 μm. When the thickness is smaller than 0.01 μm, the conductive layer is easily affected by temperature and humidity, and when the thickness is larger than 2 μm, the transparency of the transfer material is easily reduced. The surface resistivity of the conductive layer is 10 ¹¹ Ω
/ □ or less. Surface resistivity is 10 ¹¹ Ω
If it exceeds / □, the effect of voltage application is unlikely to appear, and is preferably 10 ⁹ Ω / □ or less. The position of the conductive layer in the transfer material is not particularly limited, but it is preferable to provide the conductive layer closer to the support than the light-to-heat conversion layer, from the viewpoint of preventing a reduction in resolution due to thermal diffusion. The conductive layer can be provided on the surface of the light-transmitting support. Preferably, a material in which a conductive layer, a light-to-heat conversion layer, and a color material layer are provided in this order on a light-transmitting support is preferably used.

Further, the conductive layer of the present invention may be a color material layer or a light-to-heat conversion layer provided with conductivity. The conductivity can be imparted by adding a conductive substance as described above to a light-to-heat conversion layer or a color material layer described later. When a conductive substance is added to the light-to-heat conversion layer, it is preferably added so that the surface resistivity becomes 10 ¹¹ Ω · cm or less, more preferably 10 ⁷ Ω · cm or less. . For example, in the case of the above tin oxide fine particles, 50 to 500 mg / m ² , and the tin oxide fine particle / binder ratio is preferably 20/80 to 65/35 (volume ratio), more preferably 40/60 to 60/40 (volume ratio). . When the conductive material is added to the color material layer, the amount added is 50.
５００500 mg / m ² , more preferably 70-300 mg
/ M ² , conductive material / binder ratio (volume ratio) is 20 /
8-65 / 35, more preferably 40 / 60-60 / 4
0.

[Light-to-heat conversion layer] The light-to-heat conversion layer in the transfer material of the present invention contains a light-to-heat conversion substance, and has a function (light-to-heat conversion ability) of converting energy by laser light into heat to enable thermal transfer of the ink layer. Have.

(Light-to-Heat Conversion Material) The light-to-heat conversion material that can be used in the present invention is not particularly limited, and any conventionally known light-to-heat conversion material can be used. Conventionally known photothermal conversion substances are generally dyes (eg, pigments) that can absorb laser light. Examples of such dyes (eg, pigments) include organic dyes and black such as carbon black. Pigments are mentioned, and in the present invention, it is preferable to use an organic dye in view of the film strength of the light-to-heat conversion layer.

Specific examples of organic dyes include pigments of macrocyclic compounds having absorption in the visible to near-infrared region such as phthalocyanine and naphthalocyanine, and organic dyes used as laser absorbing materials for high-density laser recording such as optical disks. (Cyanine dyes other than indolenine dyes, anthraquinone dyes, azulene dyes, phthalocyanine dyes), and organometallic compound dyes such as dithiol nickel complexes. Among them, cyanine dyes are preferred in terms of light-to-heat conversion efficiency and difficulty in being destroyed by laser light. It is desired that the light-to-heat conversion material has a high light-to-heat conversion ability.
And indolenine compounds described as general formula (I) in JP-A-140924.

The amount of the light-to-heat conversion material is preferably in the range of 1:20 to 2: 1 (light-to-heat conversion material: binder) in terms of the solid content weight ratio to the binder described later, and more preferably 1:10 to 2: 1. : 1 is preferred. If the amount of the binder is too small, the cohesive force of the light-to-heat conversion layer decreases, and when the formed image is transferred to the image receiving material, the light-to-heat conversion layer is easily transferred together, causing color mixing of the image. On the other hand, if the amount of the binder is too large, the thickness of the light-to-heat conversion layer must be increased in order to achieve a desired light absorptance, and the sensitivity tends to be reduced.

The light-to-heat conversion layer has a thickness of 0.03 to 0.8 μm.
m, more preferably 0.05 to 0.3 μm. The light-to-heat conversion layer preferably has a maximum absorption wavelength in the range of 700 to 1500 nm,
More preferably, it is in the range of 750 to 1000 nm, and the absorbance (optical density) at the wavelength is 0.1 to 1.
3, and more preferably 0.2.
~ 1.1.

(Binder) The light-to-heat conversion layer is formed by dispersing the light-to-heat conversion substance and the binder in an appropriate solvent to prepare a coating solution, coating and drying the coating solution. Examples of the binder include homopolymers or copolymers of acrylic monomers such as acrylic acid, cellulose polymers such as cellulose acetate, polystyrene, vinyl chloride / vinyl acetate copolymer, polyvinyl butyral, and polyvinyl alcohol such as polyvinyl alcohol. polymer,
Examples include condensation polymers such as polyester, polyamide, and polyimide; rubber-based thermoplastic polymers such as butadiene / styrene copolymer; polyurethane, epoxy resins, and urea / melamine resins. Among these, polyvinyl alcohol, polyvinyl butyral, polyester,
Polymers such as polyimide are preferably used. Also,
Particularly preferred binders are disclosed in Japanese Patent Application No. 10-1409.
And a polyimide resin described in No. 24.

(Method of forming light-to-heat conversion layer)
As described above, it can be provided by preparing a coating solution in which the photothermal conversion substance and the binder are dissolved and dispersed, and applying and drying the coating solution. As a solvent for preparing the coating solution, for example, 1,4-dioxane, 1,3-dioxolane, dimethyl acetate, N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, γ-butyrolactone, Water and the like. Coating and drying can be performed by ordinary coating and drying methods.

[Coloring Material Layer] The coloring material layer in the transfer material of the present invention contains a coloring matter and an amorphous organic high molecular polymer, and further contains other components as required.

(Dyes) Dyes are generally roughly classified into organic dyes and inorganic dyes. The former is particularly excellent in transparency of the coating film, and the latter is generally excellent in hiding. In addition, a metal powder, a fluorescent pigment, or the like may be used. Examples of dyes include azo dyes, phthalocyanine dyes, anthraquinone dyes,
Dioxazine dyes, quinacridone dyes, isoindolinone dyes, organic dyes such as nitro dyes, and inorganic dyes such as carbon black, titanium black, and titanium yellow can be used. From the viewpoint of the color tone, it is preferable that the organic dye to be added to the light-heat conversion layer is not substantially contained. In the present invention, “substantially free of an organic dye in a color material layer” means that the concentration of the organic dye at a wavelength showing an absorption peak of the transmission optical density (including the support component) of the ink layer is all. It means that it is 5% or less of the concentration. In the present invention, the coloring material layer preferably contains 30 to 70% by weight of the coloring matter, and more preferably 40 to 60% by weight.

(Amorphous Organic High Polymer) The amorphous organic high polymer contained in the colorant layer of the transfer material in the present invention preferably has a softening point of 40 ° C. to 150 ° C. Butyral resin, polyamide resin, polyethylene imine resin, sulfonamide resin, polyester polyol resin, petroleum resin, styrene, vinyl toluene,
α-methylstyrene, 2-methylstyrene, chlorostyrene, vinylbenzoic acid, sodium vinylbenzenesulfonate, styrene such as aminostyrene and derivatives thereof, substituted homopolymers and copolymers, methyl methacrylate,
Ethyl methacrylate, butyl methacrylate, methacrylic acid esters such as hydroxyethyl methacrylate and methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid esters and acrylic acid such as α-ethylhexyl acrylate,
Dienes such as butadiene and isoprene, acrylonitrile, vinyl ethers, maleic acid and maleic esters, maleic anhydride, cinnamic acid, vinyl chloride, vinyl acetate and other vinyl monomers alone or other monomers Can be used. These resins can be used as a mixture of two or more kinds. In the transfer material of the present invention, the color material layer is made of an amorphous organic high molecular polymer of 70%.
-30% by weight, more preferably 60% by weight.
-40% by weight.

(Other Components) According to the image forming method of the present invention, a plurality of transfer layers are used to repeatedly superpose a large number of image layers (ink layers on which images are formed) on the same image receiving material to obtain a multicolor image. When an image is formed, the colorant layer preferably contains a plasticizer in order to increase the adhesion between the images. Examples of such plasticizers include phthalates such as dibutyl phthalate, di-n-octyl phthalate, di (2-ethylhexyl phthalate, dinonyl phthalate, dilauryl phthalate, butyllauryl phthalate, butylbenzyl phthalate, etc. Acid esters, aliphatic dibasic acid esters such as di (2-ethylhexyl) adipate and di (2-ethylhexyl) sebacate, and triesters such as tricresyl phosphate and tri (2-ethylhexyl) phosphate; Examples include polyol polyesters such as polyethylene glycol esters, and epoxy compounds such as epoxy fatty acid esters, etc. In addition to the above general plasticizers, polyethylene glycol dimethacrylate, 1,2,4-butanetriol trimethacrylate , Trimethylol ethane triacryle Also, acrylates such as pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol-polyacrylate are preferably used in combination depending on the kind of the binder used. They may be used in combination.

In general, the plasticizer in the colorant layer has a weight ratio of the total amount of the dye and the amorphous organic high molecular polymer to the plasticizer of 100: 1 to 100: 3, preferably 100: 100. : 1.5 to 100: 2. To the color material layer, in addition to the above components, a surfactant, a thickener, and the like are further added as necessary. The layer thickness (dry layer thickness) of the color material layer is preferably 0.2 to 1.5 μm, more preferably 0.3 to 1.0 μm.

(Method of forming color material layer) As described above, the color material layer is prepared by preparing a coating solution in which a photothermal conversion material, a binder, and, if necessary, other components are dissolved and dispersed. Layer (if heat-sensitive release layer described below is formed, it is on top of it)
And dried. The solvent for preparing the coating liquid is the same as that described in the section of the method for forming the light-to-heat conversion layer. Coating and drying are normal coating,
It can be performed using a drying method.

[Thermal Release Layer] Between the color material layer of the transfer material and the light-to-heat conversion layer in the present invention, a gas is generated by the action of heat generated by the light-to-heat conversion material of the light-to-heat conversion layer, or water is attached. Is released, whereby a heat-sensitive release layer containing a heat-sensitive material that reduces the bonding strength between the light-heat conversion layer and the colorant layer can be provided. Examples of such a heat-sensitive material include a compound (polymer or low-molecular compound) that decomposes or deteriorates by heat to generate a gas, and a compound (polymer) that absorbs or adsorbs a considerable amount of easily vaporizable gas such as moisture. Or a low molecular compound). These may be used in combination.

Examples of the polymer which decomposes or degrades by heat to generate gas include self-oxidizing polymers such as nitrocellulose, chlorinated polyolefin, chlorinated rubber, polyvinyl chloride, polyvinyl chloride, polyvinylidene chloride, and the like. Such a halogen-containing polymer, an acrylic polymer such as polyisobutyl methacrylate in which a volatile compound such as moisture is adsorbed, a cellulose ester such as ethyl cellulose in which a volatile compound such as water is adsorbed, and a volatile compound such as water. Examples thereof include natural polymer compounds such as adsorbed gelatin. Examples of the low molecular weight compound which decomposes or degrades by heat to generate a gas include a compound which generates a gas upon exothermic decomposition such as a diazo compound or azide. It is preferable that the heat-sensitive material is decomposed or deteriorated by heat at 280 ° C. or lower, particularly at 230 ° C. or lower.

When a low-molecular compound is used as the heat-sensitive material of the heat-sensitive release layer, it is desirable to combine it with a binder. As the binder, a polymer which itself decomposes or degrades by heat to generate a gas can be used, but a normal polymer having no such properties can also be used. When a heat-sensitive low-molecular compound and a binder are used in combination, the weight ratio of the former to the latter is preferably 0.02: 1 to 3: 1, and 0.02: 1 to 3: 1.
More preferably, the ratio is 5: 1 to 2: 1. The heat-sensitive peeling layer desirably covers the light-to-heat conversion layer over substantially the entire surface thereof, and the thickness thereof is generally 0.03 to 1 μm.
And preferably in the range of 0.05 to 0.5 μm.

The heat-sensitive release layer is decomposed and deteriorated by the heat generated by the light-to-heat conversion material of the light-to-heat conversion layer to generate a gas. Then, due to this decomposition or generation of gas, the heat-sensitive peeling layer partially disappears, or cohesive failure occurs in the heat-sensitive peeling layer, and the bonding force between the light-heat conversion layer and the coloring material layer is reduced. For this reason, depending on the behavior of the heat-sensitive release layer, a part of the heat-sensitive release layer adheres to the color material layer and appears on the surface of the finally formed image, which may cause color mixing of the image. Therefore, even when the transfer of such a heat-sensitive release layer occurs, the heat-sensitive release layer is hardly colored, that is, high in visible light, so that no visual color mixture appears in the formed image. It is desirable to show permeability. Specifically, the light absorption of the heat-sensitive peeling layer is preferably 50% or less, more preferably 10% or less with respect to visible light.

In the transfer material of the present invention, instead of providing an independent heat-sensitive release layer, a coating solution of a light-to-heat conversion layer to which the above-mentioned heat-sensitive material is added is applied to a support, and the functions of the light-to-heat conversion layer should be determined. Alternatively, a configuration may be employed in which a light-to-heat conversion layer having the function that the heat-sensitive release layer should have is formed.

[Anti-reflection layer] In the transfer material of the present invention, an anti-reflection layer is preferably provided on the surface of the support opposite to the surface on which the color material layer is provided. By providing the antireflection layer, it is possible to prevent the image from being disordered and the resolution from being lowered due to irregular reflection of light during the laser light irradiation operation of irradiating the surface of the transfer material with laser light in an imagewise manner.

As a general method of forming the anti-reflection layer, materials having different refractive indices are laminated to have an anti-reflection effect on light. It is a target. Examples of materials having such an effect include sulfides such as SnS, InS, and GeS;
Oxides of n, Sn, Te, Ga, and Si are listed.

A protective cover film (eg, a polyethylene terephthalate sheet, a polyethylene sheet, etc.) may be laminated on the surface of the color material layer of the transfer material according to the present invention, if necessary, to prevent damage. Materials (especially, an image receiving material described later) can be laminated.

2. Image receiving material In the present invention, an image receiving material is a material in which a color material layer of a transfer material is transferred imagewise by irradiation of laser light to form an image, and in order to use the image receiving material as a final transfer medium, Any medium for obtaining an image, such as general paper and a plastic sheet, can be used as the image receiving material.
In order to obtain a higher definition and higher color image, an image receiving material having a surface treated to be suitable for receiving an image (hereinafter, such an image receiving material is referred to as an "image receiving sheet") is used. Is preferred.

The image receiving material is usually a plastic sheet,
One or two or more image receiving layers are provided on a usual sheet-like support such as a metal sheet, a glass sheet, and paper. Examples of the plastic sheet include a polyethylene terephthalate sheet, a polycarbonate sheet, a polyethylene sheet, a polyvinyl chloride sheet, a polyvinylidene chloride sheet, a polystyrene sheet, and a styrene-acrylonitrile sheet. As the paper, printing paper, coated paper, or the like can be used.
The thickness of the support of the image receiving material is usually from 10 to 400 μm, preferably from 25 to 200 μm. The surface of the support may be subjected to a surface treatment such as a corona discharge treatment or a glow discharge treatment in order to enhance the adhesion to the image receiving layer or the adhesion to the ink layer of the thermal transfer material.

In order to assist in transferring and fixing the color material layer of the transfer material on the surface of the image receiving material, it is preferable to provide one or more image receiving layers on the surface of the support as described above. The image receiving layer is a layer formed mainly of an organic polymer binder. The binder is preferably a thermoplastic resin, for example, acrylic acid,
Methacrylic acid, acrylic acid esters, homopolymers and copolymers of acrylic monomers such as methacrylic acid esters, methylcellulose, ethylcellulose, cellulosic polymers such as cellulose acetate, polystyrene, polyvinylpyrrolidone, polyvinylbutyral, polyvinylalcohol and the like Examples include homopolymers and copolymers of such vinyl monomers, condensation polymers such as polyesters and polyamides, and rubber polymers such as butadiene-styrene copolymers. The binder of the image receiving layer is preferably a polymer having a glass transition temperature (Tg) lower than 90 ° C. in order to obtain an appropriate adhesive strength with the ink layer. Further, it is preferable to add a plasticizer to the image receiving layer in order to adjust the glass transition temperature of the image receiving layer.

(Conductive layer) In the image receiving material of the present invention,
A conductive layer is provided below the image receiving layer. Examples of the conductive layer of the image receiving material include a layer containing a conductive substance and a binder, similarly to the conductive layer of the transfer material. As the binder and the conductive substance, those same as the conductive layer in the transfer material can be used. Further, the surface resistivity of the conductive layer in the image receiving material is preferably 10 ¹¹ Ω / □ or less. If the surface resistivity exceeds 10 ¹¹ Ω / □, it becomes difficult to transfer the color material to the image receiving material more efficiently and to prevent white spots. The surface resistivity is preferably 10 ⁹ Ω / □ or less. The thickness of this conductive layer is preferably 0.01 to 2 μm.
m, more preferably 0.05 to 0.15 μm.
When the thickness is less than 0.01 μm, the conductive layer is easily affected by temperature and humidity, and when the thickness is more than 2 μm, the transparency tends to decrease. Further, the thickness from the image receiving surface of the image receiving material to the conductive layer is preferably 30 μm or less from the viewpoint of effectively applying voltage. In particular, the thickness is preferably 20 to 30 μm.

In the laminate of the transfer material and the image receiving material, the color material layer side of the transfer material and the image receiving side of the image receiving material (the image receiving layer side in the case of the image receiving material) are overlapped and passed through a pressure heating roller. Can easily be obtained. The heating temperature in this case is preferably 130 ° C. or less, more preferably 100 ° C. or less.

3. Image Forming Method Next, an image forming method of the present invention using the transfer material and the image receiving material will be described. First, a material in which the surface of the transfer material on the color material layer side is in contact with or very close to the image receiving material is produced (hereinafter, the both materials are collectively referred to as an “image forming laminate”). .). Next, a voltage is applied between the transfer material and the image receiving material. Then, the surface of the image forming laminate is irradiated with laser light in an imagewise manner in a time-series manner (laser light irradiating operation), and then the image receiving material and the transfer material are separated from each other. An image receiving material to which the irradiation area has been transferred is obtained.

As a method of applying a voltage between the transfer material and the image receiving material, specifically, as shown in FIG. 1, a voltage is applied to the conductive layer 5 of the transfer material 10 from the external power supply A, The conductive layer 8 (or the recording drum 14) of the image receiving material 12 is grounded. Further, it is preferable that the recording drum has a vacuum forming mechanism inside and a rotating drum having a large number of minute openings on the surface, and the image receiving material is brought into close contact with the drum surface.

The voltage applied at this time may be sufficient to assist the transfer of the color material layer by the laser light irradiation operation to be performed later. The intensity of the laser light, the irradiation time, the type of the transfer material 10, the heat-sensitive release layer Presence, the type of the image receiving material 12,
Although the appropriate value differs depending on the size of the two materials 10 and 12 and the size of the recording drum 14, etc., in the present invention, it is preferably about 10 V to 2000 V, more preferably 100 V to 1 V.
About 000V. The applied voltage may be any of direct current and alternating current, and the waveform of the applied voltage may be a constant voltage or any shape such as a sine wave, a rectangular wave, or a sawtooth wave. In the present invention, in order to increase the transfer efficiency, the DC voltage V1 is replaced with the AC voltage V2 × cosω.
It is preferable that the alternating voltage is in the form of V1 + V2 × cosωt to which t is added.

In the laser light irradiation operation, scanning is performed so as to reciprocate in the width direction of the recording drum 14 from the transfer material 10 side of the image forming laminate, and the recording drum 14 is kept constant during the laser light irradiation operation. Rotate at angular velocity. Further, a configuration may be employed in which recording is performed by scanning on a plane by a laser light output head without using the recording drum 14 as described above.

Examples of the laser light include gas laser light such as argon ion laser light, helium neon laser light, helium cadmium laser light, solid laser light such as YAG laser light, semiconductor laser light, dye laser light, and excimer laser light. Direct laser light is used. Alternatively, light obtained by converting these laser lights to half the wavelength through a second harmonic element can be used. In the image forming method of the present invention, it is preferable to use a semiconductor laser in consideration of output power, ease of modulation, and the like. In the image forming method of the present invention, the laser beam has a beam diameter of 5 to 5 on the photothermal conversion layer.
Irradiation is preferably performed under the condition of 0 μm (particularly 6 to 30 μm), and the scanning speed is preferably 1 m / sec or more (particularly 3 m / sec or more).

When the image forming method of the present invention is used, even when unevenness such as dust is present on the surface of the image receiving layer,
It was confirmed by an experiment that no white spots occurred in the image. In order to give artificial irregularities to the surface of the image receiving layer, an image receiving layer is formed using a coating material for the image receiving layer to which a mat material (cross-linked polystyrene beads) has been added. Then, the diameter of the white area was measured at various diameters of the mat member. For comparison, the diameter of the blank area was measured in the same manner except that a transfer material and an image receiving material each having no conductive layer were used, and no voltage was applied between them. The results are shown in FIGS. FIG. 2 shows the relationship between the diameter of the mat member (μm) and the diameter of the blank area (mm) when an image is formed by the image forming method of the present invention, and FIG. 3 shows the result of the comparative measurement. As shown in FIGS. 2 and 3, according to the image forming method of the present invention, for example, when the mat member diameter is 4
In the case of 0 μm, the diameter of the white area is 0.75 mm, while the diameter is 1.2 mm in the comparative measurement, and the area ratio between the two white areas is approximately 1: 2.6. It can be seen that the method significantly reduces white spots.

The image forming method of the present invention can be used for producing a black mask or forming a monochromatic image, but can also be advantageously used for forming a multicolor image. In order to form a multicolor image by the image forming method of the present invention, for example, three or more types of transfer materials (three colors) each having a color material layer containing a colorant of a different color are manufactured independently, and an image receiving material is formed for each of them. A laser beam irradiation operation according to the digital signal based on the image by the color separation filter, followed by a peeling operation of the transfer material and the image receiving material to form a color separation image of each color on the image receiving material. Then, a method of laminating the image receiving material on an actual support such as a separately prepared printing paper or a support similar thereto is used.

Further, in the image forming method of the present invention,
It is also possible to provide a cushion layer in the transfer material or the image receiving material. In the present invention, by providing a cushion layer in the transfer material or the image receiving material and applying an electric field between the transfer material and the image receiving material, the effect of preventing white spots is further enhanced. In the present invention, it is not always necessary to evacuate the inside of the drum in order to support the image receiving material and the transfer material on the drum or the like, but the effect of preventing white spots is further improved by applying the evacuated.

[0053]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples. In addition, “parts” means “parts by weight” unless otherwise specified in the text.

(Example 1) <Preparation of transfer material> 1) Formation of conductive layer The components shown below in the composition of the coating solution were mixed while stirring with a stirrer, and then mixed with a paint shaker (manufactured by Toyo Seiki Co., Ltd.) for 1 hour. Dispersion treatment was performed to prepare a conductive layer coating solution. [Composition of conductive layer coating solution]-Binder (Ricacoat SN-20, manufactured by Shin Nippon Rika Co., Ltd.) 200 parts-N-methyl-2-pyrrolidone 2000 parts-Surfactant (MegaFac F-177, Dainippon Ink & Chemicals, Inc.) 0.5 parts-Tin oxide fine particles 1 100 parts

The tin oxide 1 in the above composition was prepared by the following method. Tin oxide-antimony oxide composite fine particles 8 described in Examples of JP-A-61-20033
0 parts, 160 parts of N-methyl-2-pyrrolidone, and 80 parts of zirconia beads having a diameter of 1 mm were placed in a stainless steel container and dispersed with paint sugar for 6 hours.

On one surface of a support (thickness: 75 μm, A4 size polyethylene terephthalate film),
After applying the above-mentioned conductive layer coating solution using a rotary coating machine (wheeler), the coated product was dried in an oven at 100 ° C. for 2 minutes to form a conductive layer. The surface resistivity measured in an atmosphere of 25 ° C. and 60% RH was 2 × 10 7 Ω · cm.

2) Formation of Light-to-Heat Conversion Layer The components shown in the following coating solution composition were mixed while stirring with a stirrer, and dispersed for 1 hour using a paint shaker (manufactured by Toyo Seiki Co., Ltd.). Was prepared.

[Composition of light-heat conversion layer coating solution] 10 parts of light-heat conversion substance (NK-2014, manufactured by Nippon Color Pigment Co., Ltd .; infrared absorbing dye) 10 binders (Ricacoat SN-20, manufactured by Shin Nippon Rika Co., Ltd.) 200 parts ・ N-methyl-2-pyrrolidone 2000 parts ・ Surfactant (Megafac F-177, manufactured by Dainippon Ink and Chemicals, Inc.) 1 part

After the coating solution for the photothermal conversion layer was applied on the conductive layer by using a rotary coating machine (wheeler), the coated product was dried in an oven at 100 ° C. for 2 minutes, and the photothermal conversion layer was coated on the support. A layer was formed. The thickness of the light-to-heat conversion layer was 0.29 μm as measured by SEM cross-sectional observation. The obtained light-to-heat conversion layer has a wavelength of 700 to 1000 nm.
Has an absorption maximum near 830 nm, and its absorbance (optical density: OD) is measured with a Macbeth densitometer to find that OD = 1.08.

3) Formation of Yellow Ink Layer (Coloring Material Layer) Each component shown in the following pigment dispersion mother liquor composition was subjected to a dispersion treatment for 2 hours using a paint shaker (manufactured by Toyo Seiki Co., Ltd.), and then the glass beads were removed. A pigment dispersion mother liquor was prepared. [Yellow pigment dispersed mother liquor composition] 12 parts by weight of a 20% by weight solution of polyvinyl butyral (Denka Butyral # 2000-L, Vicat softening point 57 ° C., manufactured by Denki Kagaku Kogyo Co., Ltd.) Coloring material (yellow pigment (CI. Pigment Yellow 14)) 24 parts ・ Dispersing aid (Solsperse S-20000, manufactured by ICI Corporation) 0.8 part ・ n-propyl alcohol 110 parts ・ Glass beads 100 parts

The components shown in the following coating liquid compositions were mixed while stirring with a stirrer to prepare a yellow ink layer coating liquid. [Coating liquid composition]-20 parts of the above-mentioned yellow pigment-dispersed mother liquor-60 parts of n-propyl alcohol-Surfactant (Megafac F-176PF, manufactured by Dainippon Ink and Chemicals, Inc.) 0.05 part The above-mentioned photothermal conversion layer After applying the ink layer coating solution for 1 minute using a wheeler, the coated material was dried in an oven at 100 ° C. for 2 minutes, and a yellow ink layer (pigment 64. 2% by weight, 33.7% by weight of polyvinyl butyral). When the absorbance (optical density: OD) of the obtained ink layer was measured with a Macbeth densitometer, the OD was 0.7. The thickness of the ink layer is
When measured in the same manner as in the case of the light-to-heat conversion layer, it was 0.4 μm on average. Through the above steps, a thermal transfer material in which a conductive layer, a light-to-heat conversion layer, and an ink layer were provided in this order on a support was produced.

<Preparation of Image Receiving Material> 1) Formation of Conductive Layer The transfer material was the same as the conductive layer coating solution except that the binder of the coating solution used for forming the conductive layer of the transfer material was changed to vinyl chloride / vinyl acetate copolymer. The coating solution used for forming the conductive layer was used. A conductive layer of an image receiving material was formed on one surface of a support (100 μm thick, A4 size polyethylene terephthalate film) using the above-mentioned coating solution in the same manner as the formation of the conductive layer of the transfer material. The surface resistivity of the obtained conductive layer was 7.2 × 10 ⁷ Ω / □.

2) Formation of Image Receiving Layer Formation of First Image Receiving Layer The components shown in the following coating solution composition were mixed while stirring with a stirrer to prepare a coating solution for the first image receiving layer. [Composition of the first image receiving layer coating solution] 25 parts of vinyl chloride / vinyl acetate copolymer (MPR-TSL, manufactured by Nissin Chemical Co., Ltd.) 12 parts of dibutyloctyl phthalate (DOP, manufactured by Daihachi Chemical Co., Ltd.)・ Surfactant (MegaFac F-177, manufactured by Dainippon In Chemical Co., Ltd.) 4 parts ・ Solvent (methyl ethyl ketone) 75 parts

After the above-mentioned coating solution for the first image receiving layer is applied to the surface of the conductive layer formed in 1) above using a wheeler,
The coating was dried in an oven at 100 ° C. for 2 minutes to form a first image receiving layer (thickness: 20 μm). Formation of Second Image Receiving Layer The components shown in the following coating solution composition were mixed while stirring with a stirrer to prepare a second image receiving layer coating solution. [Composition of coating solution for second image receiving layer] Polyvinyl butyral (Denka Butyral # 2000-L, manufactured by Denki Kagaku Kogyo KK) 16 parts N, N-dimethylacrylamide / butyl acrylate copolymer 4 parts Surfactant ( Megafax F-177, manufactured by Dainippon Ink and Chemicals, Inc.) 0.5 parts ・ Solvent (n-propyl alcohol) 200 parts

After the above-mentioned coating solution for the second image receiving layer is applied on the first image receiving layer using a wheeler, 10 g of the coating material is applied.
After drying in an oven at 0 ° C. for 2 minutes, a second image receiving layer (2 μm thick) was formed on the first image receiving layer. Through the above steps, an image receiving material in which a first image receiving layer and a second image receiving layer were laminated on a support was produced.

<Image Formation> An image was formed using the image forming apparatus shown in FIG. Specifically, the recording drum 14 provided with a suction hole (not shown) for vacuum suction is provided.
The image receiving material 12 is brought into contact with the surface of the rotating drum, and the transfer material 10 obtained above is placed on the rotating drum such that the surface on the side where the color material layer 2 is formed contacts the image receiving layer 7 of the image receiving material 12. The recording drum 14
By evacuating the interior, the two sheets 10,
12 was fixed to the surface of the recording drum 14 to form an image-forming laminate (this configuration was used in the present embodiment, but the image-forming laminate was previously pressed by a pressure-heating roller with the two sheets 10, 12). May be overlapped).

Further, a voltage was applied between the transfer material 10 and the image receiving material 12 by the external power supply A (the recording drum 14).
And the conductive layer 8 is grounded). The voltage applied at this time is 4
The alternating current was obtained by adding an alternating current of 100 V and 50 Hz to a direct current of 00 V. The recording drum 14 is rotated, and the wavelength 830 is applied to the surface of the image forming laminate on the recording drum 14 from outside.
semiconductor laser light having a diameter of 7 nm on the surface of the photothermal conversion layer.
Laser light was recorded on the image forming laminate while condensed so as to form a spot of μm and moved in the direction perpendicular to the rotation direction of the recording drum 14 (main scanning direction) (sub scanning). Laser irradiation conditions are as follows. Laser power: 110 mW Main scanning speed: 4 m / sec Sub-scanning pitch (sub-scanning amount per rotation): 20 μm

After performing the above-described laser image recording, the image forming laminate is removed from the recording drum 14, and the image receiving material 12 and the transfer material 10 are peeled off by hand.
An image was formed thereon. The obtained image had very good image quality.

(Embodiment 2) In this embodiment, an example is shown in which a photothermal conversion layer having conductivity is used as a conductive layer instead of an independent conductive layer. Without providing an independent conductive layer in Example 1,
An image was formed in the same manner as in Example 1, except that the composition of the light-heat conversion layer coating solution was changed as shown below. [Composition of light-heat conversion layer coating solution] 10 parts of light-heat conversion substance (NK-2014, manufactured by Nippon Color Pigment Co., Ltd .; infrared absorbing dye) 200 parts of binder (Ricacoat SN-20, manufactured by Shin Nippon Rika Co., Ltd.) -2000 parts of N-methyl-2-pyrrolidone-1 part of surfactant (Megafac F-177, manufactured by Dainippon Ink & Chemicals, Inc.)-120 parts of tin oxide fine particles 1-The surface resistivity of the light-to-heat conversion layer is 25. 4.2x at 60% RH
It was 10 ⁷ Ω · cm, and the same evaluation as in Example 1 was performed using the produced thermal transfer material. As in Example 1, good results were obtained.

(Embodiment 3) In this embodiment, an example is shown in which a coloring material layer having conductivity is used as a conductive layer instead of an independent conductive layer. An image was formed in the same manner as in Example 1 except that an independent conductive layer was not provided and the composition of the ink layer coating liquid was changed as shown below. [Composition of ink layer coating liquid]-20 parts of the above-mentioned yellow pigment-dispersed mother liquor-60 parts of n-propyl alcohol-0.05 part of a surfactant (Megafac F-176PF, manufactured by Dainippon Ink and Chemicals, Inc.)- Tin oxide fine particles 1 1.5 parts The surface resistivity of the obtained thermal transfer material was 25 ° C. and 60% RH.
Was 8 × 10 7 Ω · cm, and the same evaluation as in Example 1 was performed. As a result, good results were obtained as in Example 1.

(Example 4) A coating solution obtained by adding 0.02% by weight, based on the coating solution, of a cross-linking polystyrene particle having a particle size of 30 μm ± 10 μm to the coating solution of the third image receiving layer of the image receiving material of Example 1. An image-receiving material was prepared in the same manner as in Example 1 except that the third image-receiving layer was formed by using the same as described above, and evaluated in the same manner as in Example 1. Even if particles of 30 μm were present on the surface of the image receiving material, white spots did not occur in the image at that portion.

COMPARATIVE EXAMPLE 1 Except that the transfer material and the image receiving material were not provided with a conductive layer in Example 1,
In the same manner as in Example 1, a transfer material and an image receiving material of a comparative example were produced. The surface low efficiency of this sample is 25 ° C. 60% R
H was 9 × 10 ¹⁴ Ω · cm, and the same evaluation as in Example 1 was performed. As a result, many white spots occurred in the image, and the image quality was poor.

Comparative Example 2 A transfer material and an image receiving material of Comparative Example 2 were produced in the same manner as in Example 4 except that no conductive layer was provided on the transfer material and the image receiving material. . When the same test as in Example 1 was performed, many white spots occurred in the image, and the image was incomplete.

[0074]

According to the image forming method of the present invention, it is possible to form a high-resolution and high-quality image without white spots, without providing a cushion layer on the transfer material or the image receiving material. .

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating an image forming method of the present invention.

FIG. 2 is a graph showing white spots in an image when an image is formed by applying a voltage to a transfer material and an image receiving material used in the present invention.

FIG. 3 is a graph showing white spots in an image when an image is formed without using a voltage by using a transfer material and an image receiving material having no conductive layer.

[Explanation of symbols]

 A: External power supply 2: Color material layer 4: Light-to-heat conversion layer 5: Conductive layer 6: Support 7: Image receiving layer 8: Conductive layer 9: Support 10: Transfer material 12: Image receiving material 14: Recording drum

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigeki Kawagoe 200 Onakazato, Fujinomiya City, Shizuoka Prefecture Fuji Photo Film F-term (reference) 2C065 AB02 AC01 AC03 AF03 CA03 CA06 CA08 CA09 2H111 AA01 AA12 AA14 AA26 AA35 AA44 BA07 BA55 BA61 BA68 BA76 CA04 CA33 CA41

Claims (6)

[Claims] 1. A transfer material having at least a light-transmissive support, a light-transmissive conductive layer, a light-to-heat conversion layer, and a color material layer, and at least a support, an image-receiving layer, and a conductive layer formed below the image-receiving layer. Image receiving material having, the color material layer and the image receiving layer are superimposed on each other, and while applying a voltage between the transfer material and the image receiving material, a laser beam is irradiated imagewise from the transfer material side. An image forming method, wherein a color material layer of a transfer material is transferred to a surface of an image receiving layer to form an image on the surface of the image receiving material. 2. The thickness of the transfer material support is 3 to 200 μm.
2. The image forming method according to claim 1, wherein m is m. 3. The image forming method according to claim 1, wherein the thickness from the surface of the image receiving layer of the image receiving material to the conductive layer is 30 μm or less. 4. The image forming method according to claim 1, wherein the thickness is 20 to 30 μm. 5. The method according to claim 1, wherein the surface resistivity of each of the conductive layers of the transfer material and the image receiving material is 10 ¹¹ Ω / □ or less. Image forming method. 6. The transfer material according to claim 1, wherein at least a light-transmitting conductive layer, a light-to-heat conversion layer, and a coloring material layer are provided in this order on a light-transmitting support. An image forming method according to claim 5.