JPH04221694A - Thermal transfer recording material, thermal transfer method and preparation of printing-proof plate - Google Patents

Abstract

PURPOSE:To obtain a sharp color image without increasing a recording time by bringing a mask film having an image into close contact with the surface opposite to the surface of a thermal transfer layer of a thermal transfer recording material having a photothermal conversion layer, a release layer and the thermal transfer layer on the support thereof and subjecting said recording material to flash exposure. CONSTITUTION:A mask film having an image is brought into close contact with the surface opposite to the surface having a thermal transfer layer of a thermal transfer recording material successively having a photothermal conversion layer, a release layer and the thermal transfer layer on its support and this recording material is subjected to flash exposure through the mask film to melt the thermal transfer layer of the part corresponding to the transparent part of the mask film. When thermal transfer is applied to the image receiving layer brought into close contact with the thermal transfer layer, three colors of yellow, magenta and cyan are transferred to the image receiving layer and an image of three colors is again transferred to a separate support from the image receiving layer.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a thermal transfer recording material, a thermal transfer method, and a method for producing a printing proof plate, and more specifically, the present invention relates to a thermal transfer recording material, a thermal transfer method, and a method for producing clear color images by effectively utilizing light energy. Concerning how to create a printing proof.

0002

2. Description of the Related Art Conventionally, silver salt recording materials, photosensitive resin recording materials, and the like have been used to form high-quality images. Such recording materials have required processing using a liquid after recording. In other words, in the case of silver salt recording materials, a step is required to blacken the exposed silver particles or to develop the coupler into the desired color, and in most cases, such processing requires a liquid processing solution. there were. In addition, in the case of photosensitive resin recording materials, images are formed by taking advantage of the property that their solubility and permeability to a developing solution change upon exposure. It was necessary. Processing using such liquids produces waste liquid and is also unfavorable from an environmental hygiene perspective.

[0003] Therefore, a thermal transfer recording method is attracting attention as an image forming method that allows dry processing. However, in a thermal transfer recording method using a thermal head, the recording resolution is limited by the degree of integration of the thermal head. Furthermore, even if the degree of integration of thermal heads is increased, there is a limit to the improvement in image quality due to the influence of adjacent heads.

[0004] As a method of overcoming the limits of image quality by such a thermal head, it is possible to apply a thermal pattern based on photothermal conversion. This applies image information in the form of light and converts it into heat to generate heat and cause thermal transfer. As a thermal transfer recording method using such photothermal conversion, a transfer image is formed by recording with flash light through a transparent original using a heat-melt transfer ribbon with a heat-melt ink layer containing carbon black dispersed in a wax-based binder. A method is proposed.

However, in the case of a thermal transfer material in which a heat-melting layer is directly provided on the light-to-heat conversion layer, good image quality can be obtained when transmitted light is applied to the light-to-heat conversion layer using a mask film. In order to achieve this, the scanning speed of exposure must be slowed down, which has the drawback of increasing the recording time.

[0006]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a thermal transfer recording material, a thermal transfer method, and a printing proofing plate that can effectively utilize light energy and produce clear color images without increasing recording time. The goal is to provide a method for creating.

[0007]

[Means for Solving the Problems] As a result of intensive studies to achieve the above object, the present inventor has arrived at the present invention. The thermal transfer recording material according to the present invention is characterized in that it has a light-to-heat conversion layer, a peeling layer, and a thermal transfer layer in this order on a support.

The thermal transfer method according to the present invention involves closely adhering a mask film having an image to the surface opposite to the surface having the thermal transfer layer of a thermal transfer recording material having a light-to-heat conversion layer, a release layer, and a thermal transfer layer in this order on a support. The thermal transfer layer corresponding to the transparent portion of the mask film is melted by flash exposure from the mask film side, and is transferred to the image receiving layer that is in close contact with the thermal transfer layer.

[0009] The method for preparing a printing proof plate according to the present invention comprises forming an image on the surface opposite to the surface having the thermal transfer layer of a thermal transfer recording material having a light-to-heat conversion layer, a peeling layer, and a thermal transfer layer in this order on a support. By bringing the mask film into close contact and flash exposure from the mask film side, the thermal transfer layer in the portion corresponding to the transparent portion of the mask film is melted,
When thermally transferring to the image receiving layer that is in close contact with the thermal transfer layer,
The method is characterized in that after three colors of yellow, magenta, and cyan are transferred to the image-receiving layer, the three-color images are transferred from the image-receiving layer to another support again.

0010

According to the present invention, the light transmitted through the transparent portion of the mask film is converted into heat in the light-to-heat conversion layer, effectively melting the release layer and the thermal transfer layer, so that the ink layer can be efficiently transferred to the image-receiving layer.

[0011]

Structure of the Invention (Thermal Transfer Recording Material) The heat-sensitive transfer recording material of the present invention has a light-to-heat conversion layer, a peeling layer, and a melt transfer layer in this order on a support. The support is composed of polyester, polyamide, polyimide, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polyacrylic acid ester, polyolefin, polycarbonate, polystyrene, phenolic resin, cellulose triacetate, condenser paper, and glassine paper. When performing imagewise exposure from the support side, those having light transmittance from the above are selected and used. The thickness of the support is preferably 3 to 12 μm.

[0012] The melt transfer layer contains dyes, pigments, waxes,
Consists of binders, additives, etc. Dyes and pigments include alkaline earth metal carbonates, TiO2, MgO
, ZnO, alumina, silica, carbon black, nigrosine dye, Sudan Black SM, Fast Yellow G, Benzidine Yellow, Pigment Yellow, Oil Yellow GG, Zapon Fast Yellow CG
G, Sumiplast Yellow GG, India First Orange, Sumiplast Orange G, Pigment Orange R
, Zapon Fast Orange GG, Irgazine Red, Paranitroaniline Red, Toluidine Red,
Lysole Red 2G, Lake Red O, Oil Scarlet, Zapon Fast Scarlet OG, Eisenspiron Red BEH, Methyl Violet B Lake, Phthalocyanine Blue, Pigment Blue, First Gen Blue 5007, Victoria Blue F4R, Sudan Blue, Oil Peacock Blue, All known dyes and pigments such as Brilliant Green B and Phthalocyanine Green can be used.

[0013] As waxes, carnauba wax,
Examples include montan wax, beeswax, rice wax, candelilla wax, lanolin wax, paraffin wax, microcrystalline wax, polyethylene wax, Sasol wax, oxidized wax, amide wax, silicone wax, and the like.

As binders, polyamide resins (nylon, etc.), polyester resins, poly(meth)acrylate resins (polymethyl methacrylate, polyethyl acrylate, etc.), polyurethane resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene are used. resin,
Polyvinyl acetate resin, polyvinyl chloride-vinyl acetate resin, polyethylene resin, polypropylene resin, polybutadiene resin, polyvinyl alcohol resin, phenol resin, cellulose resin (methylcellulose, ethylcellulose, carboxymethylcellulose, nitrocellulose, acetylcellulose, etc.), polyvinyl ether resin,
Polyvinylpyrrolidone resin, polyvinylaniline resin,
Polysulfone resin, polycarbonate resin, melamine resin, epoxy resin, polyphenylene oxide resin, polyarylate resin, ionomer resin, polyether sulfone resin, polysiloxane resin, acetal resin (polyvinyl butyral, polyvinyl acetal, polyvinyl formal, etc.), petroleum-based Examples include resin, rosin resin, coumaron-indene resin, terpene resin, styrene-butadiene rubber, isoprene rubber, nitrile rubber, and the like.

[0015] As additives, various surfactants, higher fatty acids (stearic acid, palmitic acid, lauric acid, etc.)
, long-chain alcohols (stearyl alcohol, etc.), metal salts of long-chain fatty acids (calcium stearate, zinc palmitate, etc.), antioxidants, various plasticizers, silicone oil, and the like. The preferred composition ratio of each of these materials is
It also varies depending on the layer structure used.

[0016] The melt transfer layer may have a multilayer structure for efficient thermal transfer by heating.

[0017] The release layer is prepared by combining waxes, binders, and additives. It may be a layer that can cause cohesive failure by itself by melting or softening when heated, or it may be a layer that exhibits relatively low adhesive strength in combination with other resins, such as silicone resins, fluorine resins (Teflon), etc. , fluorine-containing acrylic resin, etc.), polysiloxane resin, or acetal resin (polyvinyl butyral, polyvinyl acetal, polyvinyl formal, etc.).

Preferably, the release layer of the type capable of cohesive failure itself contains a supercooled substance. By containing a supercooled substance, an image having good resolution can be obtained even if the heat-sensitive recording material and the image-receiving layer are separated after a period of time after image information is imparted by light. Examples of the supercooling substance include poly-ε-caprolactone, polyoxyethylene, benzotriazole, tribenzylamine, vanillin, and the like. Examples of the binder include the same binders as those used in the transfer layer. The thickness of the release layer is preferably 0.1 μm to 5 μm, and more preferably 0.2 μm.
μm to 2 μm is more preferable.

The photothermal conversion layer is a layer that absorbs imagewise irradiated light and increases its temperature. The light-to-heat conversion layer is created by combining a light-to-heat conversion substance, waxes, binders, and additives. The photothermal conversion substance is used to effectively utilize the energy of flash light, and any pigment or dye used for this purpose can be used as long as it converts the pattern of flash light into a thermal pattern.

Since flash light is used for exposure, a pigment with a wide absorption range is preferred. Particularly preferred are pigments that absorb in the visible and near-infrared regions, such as carbon black, carbon graphite, phthalocyanine pigments, iron powder, graphite powder, iron oxide powder, lead oxide, and blackened silver, with carbon black being particularly preferred. . Examples of the binder used in the light-to-heat conversion layer include the same binders as those used in the transfer layer. The thickness of the photothermal conversion layer is preferably in the range of 0.1 to 5.0 μm, more preferably in the range of 0.2 to 2.0 μm.

(Mask Film) The mask film used in the present invention has a structure in which a light-impermeable layer on which a negative or positive image is formed is provided on a light-transparent support.

[0022] As the light-transmitting support, acrylic resin,
Plastic films and composite films such as polyester resin and polycarbonate resin, glass, transparent paper (eg, tracing paper, condenser paper), etc. are used. The thickness of the transparent support is 30~
200 μm is preferred.

The light-impermeable layer may be constructed by appropriately combining a coloring material, a thermoplastic resin, and a heat-melting substance, and may also be a light-reflecting layer. As the light reflecting layer,
It is formed by a metal vapor deposition film such as Al, a metal powder such as Al or Ni dispersed in a thermosetting resin or a heat-fusible substance, or a silver mirror layer forming technique using a reduction method of silver halide.

[0024] For the metal vapor deposition layer, a known vacuum vapor deposition method,
For example, zinc, aluminum, gallium, indium, tin, nickel, silver, gold, copper, silicon, chromium, Titanium,
A single substance, a mixture, or an alloy of platinum, palladium, etc., which can be vapor-deposited, is formed to a thickness of about 10 to 200 nm. If the thickness is less than 10 nm, the light shielding property is insufficient and there is no value in providing the metal vapor deposited layer.
Further, even if the thickness exceeds about 200 nm, there is no effect of improving the light blocking property and it is not economical. Note that the metal vapor deposition layer or the silver mirror layer may not be one layer, but may be a plurality of layers, and in that case, the type of metal may be changed for each layer. The optical density of the light-opaque portion is preferably 1.5 or more, and more preferably 2.0 or more.

[0025] An intermediate layer may be provided between the light-transmitting support and the light-impermeable layer. The intermediate layer is a layer that adjusts the adhesive strength between the light-transmissive support and the light-impermeable layer, and when the light-impermeable layer is peeled off and removed, it may peel off at the interface of the light-transparent support, or It may remain on the support side as long as the permeability is not impaired. As the intermediate layer, a combination of a thermosoftening resin, a thermofusible substance, a mold release agent, and a surfactant can be used.

[0026] An overcoat layer may be provided on the light-opaque layer. The overcoat layer is made of a thermoplastic resin or a thermofusible substance, and can be used in combination with a coloring material, if necessary.

(Transfer method) The thermal transfer method of the present invention is carried out by bringing the mask film having an image into close contact with the surface of the heat-sensitive transfer recording material opposite to the surface having the heat transfer layer, and exposing the mask film to flash light from the side of the mask film. , the thermal transfer layer corresponding to the transparent portion of the mask film is melted and transferred to the image receiving layer that is brought into close contact with the thermal transfer layer.

As the light source for exposure, a flash light source with high light intensity, such as a xenon lamp, a halogen lamp, or a tungsten lamp, is used. As a flash light source, a xenon flash having a light emission half width of 10 ms or less and a light emission intensity of 10 W/cm2 or more is preferable.

Exposure methods using such a light source include contact exposure and scanning exposure. In the case of close exposure, the original transparent original and the mask film are brought into close contact.
Exposure is performed using the flash light source from the transparent original side. In this case, the exposure time is preferably 10 ms or less. If the exposure time is longer than 10 ms, the image quality will deteriorate due to the diffusion of the thermal pattern.

In the case of the scanning exposure method, a cylindrical scanning optical system or a plane scanning optical system is used as the recording optical system. Among these, the cylindrical outer surface scanning optical system is the most preferable because it has less loss of the light source and can easily narrow the beam.

(Method for Preparing a Printing Calibration Plate) In the present invention, when carrying out the above-mentioned transfer method, at least three transfers are performed for each of the three colors yellow, magenta, and cyan, and then the image-receiving layer is A printing proof plate can be created by transferring the color image created in 1 to another support again. As a method for transferring to another support, the color image can be transferred, for example, by overlapping the image surface of the image-receiving layer with another support such as art coated paper and passing it through a laminator or the like.

[0032]

[Example] Example 1 The film thickness after drying the following light-to-heat conversion layer mixture was 3.0 μm.
A light-to-heat conversion layer was prepared by coating and drying on a polyethylene terephthalate (PET) film having a thickness of 4.5 μm. <Light-heat conversion layer mixture> Carbon black

30 parts by weight Byron 200

70 parts by weight Methyl ethyl ketone (MEK)
400 parts by weight of the following release layer coating solution was then applied and dried to form a release layer so that the coating amount after drying was 0.5 g/m<2>.

<Release layer coating liquid> Carnauba wax

95g Ethylene vinyl acetate copolymer (Evaflex EV40Y/Mitsui DuPont Chemical)


5g toluene

400
g The above mixture was dispersed in a ball mill for 6 hours to prepare a release layer coating solution.

Next, a coating amount of 1 after drying is applied to the release layer.
．． A heat-sensitive transfer recording material was prepared for each color by coating and drying the following color material layer coating solution to form a heat-sensitive transfer layer at a concentration of 5 g/m2.

<Preparation of coating liquid for coloring material layer> The following dispersion for coloring material layer

100g paraffin wax (melting point 73℃)
20% by weight MEK dispersion 100g phenolic resin (Tamanol 510/manufactured by Arakawa Chemical Co., Ltd.)
25g rosin modified resin (Hariestar T/Harima Kasei)
30g Ethylene-vinyl acetate copolymer (Evaflex EV40Y/Mitsui DuPont Chemical)


5g MEK

A mixture of 240 g or more was prepared for each coloring material, and coating liquids for each coloring material layer of yellow, magenta, and cyan were prepared.

(Yellow dye dispersion for color material layer) SYMULER FAST YELLOW 8GF
(C.I.pigment No.Y-17)
100g acrylic resin


5g methyl ethyl ketone (MEK)

400 ml of the above mixture was dispersed in a ball mill for 5 hours to prepare a yellow dye dispersion.

(Magenta pigment dispersion for coloring material layer) FASTOGEN SUPER MAGENTA
R (C.I.pigment No.R-122)
100g styrene maleic acid resin
A magenta dye dispersion was prepared by dispersing 5 g of the above mixture in a ball mill for 5 hours. (Cyan dye dispersion for color material layer) FASTOGEN BLUE TGR (C.I.p.
igment No. B-15:3)
100g acrylic resin


5g MEK

A cyan dye dispersion was prepared by dispersing 400 ml of the above mixture in a ball mill for 5 hours. Furthermore, on the back side of the above PET film, a silicon modified urethane resin (SP-21
05, manufactured by Dainichi Seika) is provided.

<Preparation of image-receiving material> An image-receiving material was obtained by applying the following image-receiving layer paint to a dry film thickness of 2 μm on a polyester base (white PET) kneaded with titanium oxide pigment. (Image-receiving layer paint) Polyester resin

20g MEK

200ml
cyclohexanone

50ml

<Preparation of heat-sensitive transfer and printing proof plate> The heat-sensitive transfer recording material and the image-receiving material are stacked so that the transfer layer surface of the heat-sensitive transfer recording material and the image-receiving surface of the image-receiving material face each other, and the heat-sensitive transfer recording material side is A 1W semiconductor laser light source was focused to 30 μm, and scanning exposure was performed at a speed of 120 m/sec.

[0040] Both the thermal transfer recording material and the image receiving material are 30 mm.
/second, and the two were separated at a position of 1 mm after exposure, and the exposed portion of the coloring material layer was transferred to the image-receiving layer. After performing this operation for each of the colors yellow, magenta, and cyan, the image surface of the image receiving material on which the images of the three colors were formed was placed over art coated paper and passed through a laminator. A color image was transferred. Note that the hot plate temperature of the laminator was 110°C.

Comparative Example 1 Using a heat-sensitive transfer recording material and an image-receiving material prepared in the same manner as in Example 1 except that only the release layer of the heat-sensitive transfer material was removed, similar heat-sensitive transfer and printing proof plates were prepared and evaluated. went. As a result, in order to obtain good image quality, the scanning speed of the laser beam had to be set to 40 m/sec, resulting in an increase in recording time.

Example 2 A heat-sensitive transfer recording material and an image-receiving material prepared in the same manner as in Example 1 were used, except that the release layer of the heat-sensitive transfer material in Example 1 was replaced with the following. When a printing proof plate was created, the scanning speed of the laser beam could be set to 160 m/sec in order to obtain a good image. (Peeling layer) Paraffin wax (melting point 73°C)
90 parts by weight
Poly-ε-caprolactone (Plaxel H1, Daicel Chemical) 10 parts by weight

[0043]

[Effects of the Invention] According to the present invention, there are provided a thermal transfer recording material, a thermal transfer method, and a method for creating a printing proof plate that can effectively utilize light energy and obtain clear color images without increasing recording time. can.

Claims (3)

[Claims] 1. A thermal transfer recording material comprising a light-to-heat conversion layer, a release layer, and a thermal transfer layer in this order on a support. 2. A mask film having an image is brought into close contact with the surface opposite to the surface having the thermal transfer layer of a thermal transfer recording material having a light-to-heat conversion layer, a release layer, and a thermal transfer layer in this order on a support,
A thermal transfer method characterized in that a portion of the thermal transfer layer corresponding to the transparent portion of the mask film is melted by flash exposure from the side of the mask film, and is transferred to an image receiving layer that is in close contact with the thermal transfer layer. 3. A mask film having an image is brought into close contact with the surface opposite to the surface having the thermal transfer layer of a thermal transfer recording material having a light-to-heat conversion layer, a release layer, and a thermal transfer layer in this order on a support,
By flash exposure from the mask film side, the portion of the thermal transfer layer corresponding to the transparent portion of the mask film is melted, and when thermally transferred to the image receiving layer that is in close contact with the thermal transfer layer, A method for preparing a printing proof plate, which comprises transferring three colors of yellow, magenta, and cyan, and then transferring the images of the three colors from the image-receiving layer to another support.