JP2003305962A - Composition for thermal transfer-type ink image- receiving sheet, and thermal transfer-type ink image- receiving sheet using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for a thermal transfer-type ink image-receiving sheet, which, when used in a thermoelectric printer for thermal transfer ink, exhibits excellent gradation reproduction, dot reproduction, sharpness in color images, and suitability for high-speed recording and, at the same time, has excellent suitability for printing and can yield a high-grade and high-quality image, and to provide an image-receiving sheet using the same and a print using the image-receiving sheet. <P>SOLUTION: This composition for a thermal transfer-type ink image-receiving sheet is used in a heat-fusible ink image-receiving layer. The composition contains an inorganic filler (A-1) and/or an organic filler (A-2) and contains, as indispensable ingredients, a water-soluble polymer emulsion (B-1) and/or a hydrophobic polymer emulsion (B-2) having a water adsorption of 0.1 to 2% by weight as measured at a temperature of 20°C and a relative humidity of 80%. In the thermal ink transfer-type image-receiving sheet, a coating composition comprising the above composition as an indispensable ingredient is coated onto one side of a substrate to provide an image- receiving layer which receives a heat-fusible ink. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composition for a melt transfer type ink image-receiving sheet, a melt transfer type ink image-receiving sheet using the composition, and a printed matter obtained by using the image receiving sheet. More specifically, when used in a melt transfer type thermal transfer printer using a thermal head, a print ink image having a high recording density, excellent gradation reproducibility, dot reproducibility and sharpness of a color image can be obtained. The present invention also relates to a composition for a melt transfer type ink image-receiving sheet having excellent blocking resistance, a melt transfer type ink image-receiving sheet using the composition, and a printed matter obtained by using the image receiving sheet.

[0002]

2. Description of the Related Art With the rapid development of OA and FA in recent years, copying machines, printers, facsimiles, etc. using various recording systems such as electrophotographic systems and thermal transfer recording systems are used according to their respective applications. It has been done, for example, CAD /
It is also widely used in CAM and the like. Colored color materials are used for image formation in such a thermal transfer recording method, and usually, the color materials are melted, evaporated, and sublimated to be transferred onto a recording medium, for example, an image receiving paper such as paper or a film sheet, and adhered. The recorded image is formed by the adsorption, dyeing action.

By the way, in this type of recording system, an ink transfer sheet having a heat-meltable ink image-receiving layer composed of a coloring material and wax or a resin is melted by heat generated by a thermal head or an energizing head. , The thermal transfer recording method of the thermal fusion type, in which the color material is transferred to the image receiving paper to obtain a recorded image
In particular, since the device is simple and compact, and has advantages such as maintenance-free, ticket papers such as ticket, commuter ticket, airline ticket, labels such as POS label, which require reliability and security, Also, attention is being paid to use for cards such as prepaid cards. Further, the heat-melt type transfer recording method has a feature that plain paper can be used as a recording medium.

However, like the other recording systems, such a thermal transfer recording system is also required to improve full-color recording, high-speed recording, clear image, high resolution, etc., together with the performance improvement and improvement of the recording apparatus. Plain paper is no longer available. For example, in the case of labels, when a bar code recorded at high speed is read using a reading device, if the image quality is poor and many missing dots or line breaks are seen, the bar code etc. Since it cannot be read, there is a problem that it fails as an image receiving paper. Further, in the case of paper sheets and cards combined with the magnetic recording system, the image receiving paper is used in order to pass the cards or the like at a high speed in the apparatus having the built-in magnetic head or to be repeatedly used for a long period of time. If the transferred image transferred to the paper is rubbed and soiled, or if dots are lost due to scratches or the like, there is a problem in that the fixing property and the robustness become problems, and the card cannot serve its function. Furthermore, in order to obtain high gradation reproducibility with full-color thermal transfer recording, the size of each dot is changed in the printer from the conventional method of obtaining gradation without changing the size of one dot. In the image receiving sheet, the dot shape of the melt-transferred ink is faithfully reproduced in full-color recording from low applied energy to high applied energy. A large amount of ink is transferred, and high recording density is required as an important quality of a recorded image.

With respect to the full-color thermal transfer image as described above, it is necessary to appropriately correspond the characteristics of the image receiving sheet. That is, in the full-color hot-melt transfer method, when non-coated paper for ordinary printing is used, there are problems such as a decrease in recording density, which is considered to be due to low heat insulation, and poor dot reproducibility due to insufficient cushioning. May occur. Further, if the surface is too rough, a phenomenon that causes a portion where the ink is not transferred, that is, "blank" occurs, and if the surface is too smooth, the anchoring effect of the ink becomes insufficient, The transferred ink is reversely transferred to the ink ribbon, which easily causes missing. Any of these causes poor dot reproducibility. In addition to the reduction of the recording density due to the poor dot reproducibility as described above, the reduction of the recording density due to the low ink absorbability of the heat-meltable ink image receiving layer may occur.

As an attempt to solve these problems, it has been proposed to provide an undercoat layer containing hollow particles on a sheet-like support to improve the cushioning property of the image-receiving sheet (Japanese Patent Laid-Open No. 2-89690). Publication, JP-A-6
No. 4-27996). However, such attempts are still insufficient for improving the cushioning property and heat insulating property of the image receiving sheet, and when the hollow particles are dissolved in the organic solvent of the image receiving layer, the organic solvent resistance is high. It is necessary to use the molecule as an adhesive for hollow particles, or to provide an organic solvent resistant polymer layer on the layer containing hollow particles,
Manufacturing problems are also occurring. As another attempt to solve the above problem, a resin layer containing a component that dissolves in water is formed on a sheet-shaped support containing plastic as a main component, and a water-soluble component is eluted and removed from the resin layer. It has also been proposed to form fine pores in the image receiving sheet, thereby improving the ink receiving ability of the image receiving sheet (JP-A-2-412).
No. 87). However, in this case, there is a defect that the maximum density is still insufficient, or the printed image has no gloss,
It has not been possible to satisfy the ever-increasing quality requirements for image-receiving sheets. Further, since this image receiving sheet is mainly composed of plastic, there is a problem that it is difficult to recycle resources. Also known is a method in which thermally expandable microcapsules are mixed as expandable particles in a pulp slurry to impart heat insulation and cushioning properties (Japanese Patent Nos. 3089823, 3089824 and 3089827). However, in addition to the problem that the unevenness of the heat-insulating layer due to the non-uniform foaming property of the microcapsules leads to the deterioration of the surface property of the image recording surface and the reproducibility of the low gradation part is reduced, Microcapsules are hollow ones containing a thermoplastic material as a shell and a low boiling organic solvent such as propane or isobutane inside, and when they are foamed by heating, carbon dioxide gas or organic gas is released into the atmosphere. discharge. This fact goes against the recent trend of reducing environmental load, and is one of the problems to be considered regarding measures for reducing environmental load of raw materials.

[0007]

DISCLOSURE OF THE INVENTION The present invention is excellent in gradation reproducibility, dot reproducibility, color image sharpness, high-speed recording suitability and excellent printing when used in a melt transfer type thermal transfer printer. To provide a high-quality and high-quality composition for a melt transfer type ink image receiving sheet which also has suitability, a melt transfer type ink image receiving sheet using the same, and a printed matter obtained by using the image receiving sheet. is there.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that in a melt transfer type ink image-receiving sheet having a heat-meltable ink image-receiving layer formed on a substrate, The meltable ink image receiving layer has a relative humidity of 80 at 20 ° C.
Inorganic filler (A-1) and / or organic filler (A-) having a moisture adsorption rate of 0.1 to 2% by weight.
By using a composition for a melt transfer type ink image-receiving sheet containing 2) and containing a water-soluble polymer (B-1) and / or a hydrophobic polymer emulsion (B-2) as an essential component,
Providing a heat-meltable ink image-receiving layer with excellent heat insulation and cushioning properties by using an environment-friendly material that does not adversely affect the environment without using thermally expandable capsules that generate carbon dioxide gas or organic gas As a result, they have found that a melt transfer type ink image-receiving sheet capable of uniform and high-density clear image recording, and a printed matter using the image-receiving sheet can be obtained, and completed the present invention.

That is, in the present invention, as a filler, the moisture adsorption rate at 20 ° C. and 80% relative humidity is 0.1 to 2% by weight.
Containing an inorganic filler (A-1) and / or an organic filler (A-2) which is a water-soluble polymer (B-1) and / or a hydrophobic polymer emulsion (B-2) as an essential component. And a composition for a melt transfer type ink image-receiving sheet.

Further, in the present invention, an image receiving layer which receives a heat-meltable ink is provided by coating a coating composition containing the above composition for a melt transfer type ink image receiving sheet as an essential component on one surface of a substrate. And a melt transfer type ink image receiving sheet.

Further, the present invention relates to a printed matter obtained by using the above-mentioned melt transfer type ink image receiving sheet.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, necessary items for carrying out the present invention will be specifically described below.

The melt transfer type ink image-receiving sheet of the present invention comprises
An image receiving layer for receiving a hot-melt ink is provided by coating a coating composition containing the composition for a melt transfer type ink image receiving sheet of the present invention as an essential component on one surface of a substrate.

In the melt transfer type ink image-receiving sheet of the present invention, the above-mentioned heat-meltable ink image-receiving layer provided on one surface of the substrate comprises an inorganic filler (A-1) and / or an organic filler (A-2). The fine pores formed by the water-soluble polymer (B-1) and / or the hydrophobic polymer emulsion (B-2) keep the heat-insulating property of the heat-meltable ink image-receiving layer well, and Is characterized in that the heat of the heat-melting ink image-receiving layer surface is moderately stored, and that the fine pores described above improve the cushioning property of the image-receiving sheet to achieve high adhesion with the thermal head during printing, As a result, it is provided for the purpose of improving the acceptability of the transfer ink, the sharpness of the image, the transfer unevenness, and the dot omission.

The composition for a melt transfer type ink image-receiving sheet of the present invention, as a filler, is an inorganic filler (A-1) having a moisture adsorption rate at 20 ° C. and a relative humidity of 80% of preferably 0.1 to 2% by weight. And / or organic filler (A-
2) and contains a water-soluble polymer (B-1) and / or a hydrophobic polymer emulsion (B-2) as an essential component. In the present invention, an inorganic filler (A-1) and / or an organic filler (A-2) having a moisture adsorption rate of preferably 0.1 to 2% by weight under the condition of 20 ° C. and a relative humidity of 80% are used. As a result, the water-soluble polymer (B-
1) and / or the point where a void is formed between the hydrophobic polymer emulsion (B-2) and the filler, that is, the water adsorption rate under the condition of the binder and 20 ° C. and 80% relative humidity is preferably 0.1. ~ 2 wt% inorganic filler (A
The greatest feature is that a melt transfer type ink image-receiving sheet that meets actual use conditions can be obtained by using only -1) and / or the organic filler (A-2). Furthermore, the heat-expandable microcapsules that have been used up to now have a problem that they adversely affect the environment because they generate carbon dioxide gas and organic gas when foaming. One of the features is that the material used for the heat-meltable ink image-receiving layer of the sheet is environmentally friendly because no material that adversely affects the environment is used at all.

The water absorption rate under the condition of 20 ° C. and 80% relative humidity in the present invention means the water absorption isotherm used as a conventional method for quantitatively grasping the hydrophilicity and hydrophobicity of the filler, That is, it means the moisture absorption rate at a relative humidity of 80% in a relative temperature-moisture absorption rate curve obtained by measuring the moisture absorption rate at different relative temperatures under constant temperature conditions (20 ° C. in the present invention). .
Specifically, a certain amount of filler is 20 ° C, relative humidity is 80 ° C.
After being left for 2 hours under the conditions of 1., about 1 g is weighed with a precision chemical balance, dried at 105 ° C. for 2 hours, and after standing for 30 minutes with a desiccator, the weight is measured. The percentage of the value obtained by dividing the amount of change in weight before and after drying by the initial weight in this method is the moisture adsorption rate.

Inorganic filler (A-1) used in the present invention
Or, as the organic filler (A-2), a known and commonly used filler is used, and examples thereof include diatomaceous earth, talc, clay, kaolin, calcined kaolin, calcium carbonate, silica, magnesium carbonate, basic magnesium carbonate, titanium oxide, and oxide. Zinc, silicon oxide, aluminum hydroxide,
Inorganic fillers such as calcium silicate, barium sulfate, calcium sulfate, surface-treated calcium and silica,
Polystyrene resin, benzoguanamine resin, polyethylene resin, polypropylene resin, silicone resin, urea-
Organic fillers such as formalin resin and styrene / methacrylic acid copolymer can be used, and among them, those having a water adsorption rate of 0.1 to 2% by weight under the condition of 20 ° C. and 80% relative humidity are preferable. . Moreover, these inorganic fillers (A-1) and / or organic fillers (A-2) may be used alone or in combination of two or more.

Inorganic filler (A-1) used in the present invention
And / or the organic filler (A-2) is a water-soluble polymer (B-1) and a water-soluble polymer (B-1) if the water adsorption rate is in the range of 0.1 to 2 wt% under the condition of 20 ° C. and 80% relative humidity. / Or moderate voids are formed between the hydrophobic polymer emulsion (B-2) and the filler, sufficient heat insulation is ensured, and thermal energy from the thermal head is suppressed from being lost to the outside through the base material. It is preferable because the sensitivity is increased. Furthermore, the compatibility with the water-soluble polymer (B-1) and / or the hydrophobic polymer emulsion (B-2) is good, and stability as a compounding liquid is obtained, which is preferable.

The composition for a melt transfer type ink image-receiving sheet of the present invention is selected as a filler from inorganic hydrophobic silica surface-treated with an organic silicon compound and / or silicone oil, and a hydrophobic organic filler composed of a methyl silicone resin. It contains at least one kind. Among the above fillers used in the present invention, preferably silanol groups present on the surface of silica are treated with organic silicon compounds such as octylsilane and trimethylsilane, hydrophobic silica, titanium oxide, titanium dioxide, or surface treatment with silicone oil. Examples of the hydrophobic silica include high-purity fine particles of highly hydrophobic methyl silicone resin. The filler does not include heat-expandable microcapsules.

The average particle size of the filler used in the present invention can be appropriately adjusted depending on the intended print density of the melt transfer type ink image receiving sheet, but is not particularly limited, but the surface smoothness of the image receiving sheet is maintained. However, in order to maintain the adhesion with the thermal head during thermal transfer, it is usually 10 μm.
It is preferably m or less. When the average particle diameter is 10 μm or less, the smoothness of the surface after coating and drying can be maintained, the adhesiveness with the thermal head does not decrease, and the sensitivity improving effect can be expected. Further, the filler used in the present invention together with the surface smoothness is a water-soluble polymer (B-1) and / or a water-soluble polymer (B-1) in order to act as a heat-insulating layer for improving the print density by efficiently utilizing the heat energy from the thermal head or the like. Alternatively, it is particularly preferable to use a filler having an average particle size of 5 μm or less from the viewpoint of efficiently forming voids with the hydrophobic polymer emulsion (B-2).

Water-soluble polymer (B-1) used in the present invention
As described above, the hydrophobic polymer emulsion (B-2) is an inorganic and / or organic hydrophobic resin having a water adsorption rate of 0.1 to 2% by weight at 20 ° C. and a relative humidity of 80%. Filler, that is, (A-1) and / or (A-2)
It is an essential component for forming voids by coating and drying on the surface of the substrate after mixing with. Although it is not clear why the voids are formed here, the water-soluble polymer (B-1) and / or the hydrophobic polymer emulsion (B-
Water, which is the dispersion medium of 2), is volatilized under the condition that it is difficult to be compatible with the surface of the inorganic and / or organic filler which is rich in hydrophobicity, and at the same time, the water-soluble polymer (B-1) and / or the hydrophobic polymer emulsion. (B-2) is heat-cured by drying. This is because the air held by the filler itself at this stage and the residual air present in the blended liquid remain at the interface between the resin and the filler, resulting in the formation of an air layer around the filler, that is, voids. It is estimated to be. The appropriate voids and cushioning properties thus formed can be imparted. Therefore, the heat-insulating properties of the heat-meltable ink image-receiving layer can be maintained well, and the heat from the thermal head can be appropriately stored on the surface of the image-receiving layer. As a result, the acceptability of the transfer ink and the clear image The properties are remarkably improved, and further, the effect of improving transfer unevenness and dot omission is excellent, so that the quality characteristics of the image receiving sheet for thermal transfer recording are dramatically improved. In addition, the water-soluble polymer (B-1)
And / or the hydrophobic polymer emulsion (B-2) is an essential component also for the purpose of maintaining the binding property between the substrate and the heat-meltable ink image-receiving layer.

Water-soluble polymer (B-1) used in the present invention
Alternatively, the hydrophobic polymer emulsion (B-2) may be any polymer as long as it is a known and commonly used polymer as a dispersion medium, and examples thereof include polyvinyl alcohol, modified polyvinyl alcohol, starch and its derivatives, Cellulose derivatives such as methoxy cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide / acrylic acid ester copolymer, acrylamide / acrylic acid ester / methacrylic acid ester terpolymer, styrene / Alkaline or ammonium salt of maleic anhydride copolymer, Alkali salt or ammonium salt of isobutylene / maleic anhydride copolymer, Alkaline salt of ethylene / maleic anhydride copolymer or Water-soluble polymers such as ammonium salts, polyacrylamide, sodium alginate, gelatin and casein, polyurethane resins, polyester resins, polyvinyl chloride resins, ethylene / vinyl chloride copolymers, polyacrylic ester resins, styrene / butadiene copolymers (SBR), styrene / butadiene / acrylic acid ester copolymer, acrylonitrile-butadiene copolymer,
Acrylic ester-butadiene copolymer, ethylene /
Hydrophobic polymer emulsions such as vinyl acetate copolymers, vinyl acetate resins, vinyl acetate / acrylic acid ester copolymers, styrene / acrylic acid ester copolymers, and polymer latex emulsions can be used. Specific examples of the water-soluble polymer (B-1) or the hydrophobic polymer emulsion (B-2) include those described above, but the present invention is not limited to these specific examples. Absent. In addition, these water-soluble polymers (B
-1) and / or hydrophobic polymer emulsion (B-2)
May be used alone or in combination of two or more.

The inorganic filler (A-1) and / or
Alternatively, the organic filler (A-2) and the water-soluble polymer (B-
When the heat-meltable ink image-receiving layer containing 1) and / or the hydrophobic polymer emulsion (B-2) is formed, for example, it is preferable that the heat-meltable ink image-receiving layer is applied to the surface of the substrate and dried.
In this case, the amount of the inorganic filler (A-1) and / or the organic filler (A-2) used is such that the water-soluble polymer (B-
1) and / or with respect to 100 parts by weight of the resin solid content of the hydrophobic polymer emulsion (B-2), preferably 10 to 3
It is in the range of 00 parts by weight, more preferably 20 to 250.
The range is parts by weight. When the amount of the inorganic filler (A-1) and / or the organic filler (A-2) used is in such a range, excellent heat insulating properties, cushioning properties, and binding properties between the base material and the heat-meltable ink image receiving layer are brought about. You can

The heat-meltable ink image-receiving layer of the present invention may contain, if necessary, known auxiliary additives such as pigments, antistatic agents, leveling agents, and the like within a range that does not impair the heat insulating property and cushioning property. A thickener and the like can be used in combination, and there is no particular limitation.

The pigment used in the present invention is not particularly limited, and known and commonly used pigments can be used, for example, zinc oxide, titanium oxide, calcium carbonate, silicic acid, silicate, kaolin clay, magnesium oxide, satin white, Basic calcium carbonate, aluminum oxide, talc, mica, calcined clay, aluminum hydroxide, barium sulfate,
Inorganic pigments such as lithopone and colloidal silica, true pigments such as polystyrene, polyethylene, polypropylene, epoxy resin, and styrene-acrylic copolymer, hollow or organic pigments called plastic pigments of a type processed into various shapes, Examples thereof include starch powder and cellulose powder, which may be used alone.
You may use together 1 or more types.

The leveling agent used in the present invention is not particularly limited, and known and commonly used ones can be used, for example, polyoxyethylene alkyl ether type, polyoxyethylene fatty acid ester type, polyoxyethylene alkylphenyl ether type. , Sorbitan fatty acid ester type, polyoxyethylene sorbitan fatty acid ester type,
Nonionic hydrocarbon surfactants such as polyoxyethylene alkylamine ether type, fatty acid diethanolamide type, sucrose ester type, dialkyl sulfosuccinic acid ester type, polyoxyethylene alkyl ether sulfate type, higher alkyl ether sulfate ester salt, phosphorus Anionic hydrocarbon-based surfactants such as acid ester salts, quaternary ammonium-based cationic hydrocarbon-based surfactants such as alkyltrimethylammonium chloride,
Amphoteric hydrocarbon surfactants such as dimethyl alkyl lauryl betaine, alkyl glycine, amido betaine type,
Polymeric hydrocarbon type surfactants such as imidazoline type polyoxyethylene polyoxypropylene block polymers, special acetylene glycol type surfactants, silicone type surfactants, fluorine type surfactants, etc. May be used alone or in combination of two or more.

Further, as the thickener used in the present invention,
There is no particular limitation, and known conventional ones can be used, for example, cellulose derivatives such as hydroxyethyl cellulose, methyl cellulose, carbooxymethyl cellulose, polyacrylates, polyvinylpyrrolidone, or urethane-based, polyether-based associative polymer surfactants. Examples include agent-based thickeners, which may be used alone or in combination of two or more kinds.

The melt transfer type ink image-receiving sheet of the present invention comprises
An image receiving layer for receiving a heat-meltable ink is provided on one surface of a base material by applying a coating composition containing the composition for a melt transfer type ink image receiving sheet as an essential component.

The coating amount of the coating composition is a dry weight on one side.
Per hit, preferably 1 to 50 g / m ^TwoIs the range of
More preferably 2-35 g / m^TwoIs the range. The coating group
Within the range of application amount (dry weight per side) of the product
If so, the surface roughness of the sheet-shaped substrate can be sufficiently covered.
And an image receiving sheet with a proper smoothness can be obtained.
It provides excellent heat insulation and compressive deformability, and
Sufficient bond strength of the porous ink image-receiving layer is obtained to form an image.
The peeling trouble of the ink image receiving layer is suppressed when
Image is obtained.

In the present invention, as a method for coating the heat-meltable ink image-receiving layer on the substrate, generally known and commonly used coating devices such as blade coaters, knife coaters, air knife coaters, roll coaters, reverse roll coaters,
Equipment such as bar coater, chanplex coater, curtain coater, die slot coater, gravure roll coater, brush coater, two roll, or metering blade type size press coater, short dwell coater, bill blade coater, gate roll coater, sprayer, etc. Used. These devices are applied or impregnated in the form of an on-machine coater or an off-machine coater.

The melt transfer type ink image-receiving sheet having the heat-meltable ink image-receiving layer of the present invention can show a good melt heat transfer image even when the coating composition is coated on a substrate and dried. However, using a machine calendar composed of two or more metal rolls, a metal roll and a resin roll, or a super calendar composed of a combination of a metal roll and a cotton roll, etc. The meltable ink image-receiving layer can be subjected to a finishing treatment to further improve the smoothness of the surface.
After coating, the surface of the heat-fusible ink image-receiving layer of the sheet in a semi-dry state or a dry state is brought into contact with a mirror-finished heated or non-heated cast drum or the like to smooth the surface. You may improve the property. However, if the smoothing treatment is applied under excessive pressure, the resin wall surrounding the fine pores in the heat-meltable ink image-receiving layer is destroyed, and the ink image-receiving layer is densified, resulting in heat insulation and cushioning. Since the deterioration or the deformation or destruction of the pores on the surface of the ink image receiving layer may occur, the excellent melt ink transfer performance of the heat melting ink image receiving layer may not be obtained.
Therefore, the processing conditions of the smooth finishing process may be appropriately selected according to the performance of the image receiving sheet. Further, when forming the image receiving layer, the image receiving layer may have a single layer structure or a multilayer structure of two or more layers as required. In the case of a multi-layer structure, each coating composition does not have to be the same, and may be appropriately adjusted and blended according to the required quality level, and is not particularly limited.

Examples of the base material used in the melt transfer type ink image-receiving sheet of the present invention include papers containing cellulose as a main component, coated papers, laminated papers, and the like.
Cloths such as woven cloth and non-woven cloth can be used. Further, plastic films such as polyolefin, methacrylate and cellulose acetate, synthetic paper made of polyolefin and pigment, and porous synthetic resin film such as foamed polyethylene terephthalate film and foamed polypropylene film can be used. These sheet-like supports have better heat insulation and have better dot reproducibility and gradation reproducibility with the same applied energy, and can achieve an increase in recording density. It is also effective for energy saving because it requires less energy to obtain quality. Further, when paper or coated paper containing pulp as a main component is used as the sheet-like support, there is also an advantage that it can be particularly recycled. Incidentally, the paper base material includes various ordinary paper additives, for example, dry paper strength enhancer (cationized starch, cationized polyacrylamide, etc.), sizing agent (fatty acid salt, rosin, maleated rosin, cationized sizing agent). , Reactive size agents, etc., fillers (clay, kaolin, titanium, etc.), wet paper strength agents (melamine resins, epoxidized polyamide resins, etc.), fixing agents (aluminum sulfate, cationized starch, etc.), pH adjusters ( Caustic soda, sodium carbonate, etc.) and the like. The base paper is tab-sized or size-pressed with a treatment liquid containing one or more of water-soluble polymer additives, sizing agents, inorganic electrolytes, hygroscopic substances, pigments, dyes, pH adjusting agents, etc. Good. Further, these base materials may be opaque, transparent, or semitransparent, and
A white pigment, an organic dye or pigment, or bubbles may be contained in the base material or on the surface thereof in order to make the background look white or other specific color. In particular, application may be difficult when a substrate having low hydrophilicity such as films is selected. In that case, hydrophilic treatment of the surface by corona discharge or the like, and a water-soluble polymer (B -1) and / or hydrophobic polymer emulsion (B-2) may be applied to the surface of the substrate for easy adhesion treatment.

Further, when the melt transfer type ink image-receiving sheet of the present invention is manufactured, the image-receiving sheet itself may be curled with its coated surface inside or outside in the steps of coating, drying and winding. is there. In this case, if the image-receiving sheet is used after being cut into an image-forming image-forming sheet having a predetermined size, it may not be properly fed to the melt transfer type thermal transfer printer, or the running property inside the printer may deteriorate. Deteriorating problems may occur. Further, the melt transfer recording method is a method in which a heat source is brought into contact with an ink ribbon and the dye component in the ribbon is transferred onto an image receiving sheet, so that the heat melting ink image receiving layer which is an image forming surface and the substrate are heated. Due to the difference in the contraction or the difference in the expansion characteristics, the image receiving sheet curls inside the apparatus, and the above-mentioned problems occur. Due to such curling, an image is formed obliquely with respect to the normal paper surface direction, or wrinkles are easily generated on the image receiving sheet inside the apparatus, and thus the contact between the ink ribbon and the image receiving sheet is not normally performed. In some cases, poor ink transfer may occur, resulting in poor image quality. In order to prevent various troubles caused by such curling, it is necessary to minimize the difference in shrinkage characteristics or the difference in expansion characteristics between the heat-meltable ink image-receiving layer and the sheet-shaped substrate due to heating. desirable. Therefore, a curl prevention layer may be coated or laminated on the back surface of the image receiving sheet, that is, the surface opposite to the heat-meltable ink image receiving layer. There is no particular limitation on the material, forming method, coating amount, laminating amount, etc. of the anti-curl layer, and the type and thickness of the sheet-shaped substrate or the properties of the heat-meltable ink image-receiving layer, that is, the material composition, coating Optimization can be performed in consideration of various factors such as quantity.

Further, in the present invention, depending on the kind of the material of the sheet-shaped base material, when the obtained image-receiving sheet travels in the printer, various frictional forces may be applied due to the mechanism of the apparatus,
In some cases, the influence of a decrease in humidity inside the apparatus due to heating may affect the image-receiving sheet electrostatically or independently. When a large number of images are continuously formed in such a state, the image forming surface of the image receiving sheet,
There is a problem that the back surface of the next image receiving sheet is electrostatically adhered to it and it becomes difficult to peel it off. In particular, since various plastic sheets or synthetic papers are inherently prone to electrostatic charges, when these are used as a base material, static electricity may be generated during the sheeting process by cutting or during storage of the sheet after processing. Due to the occurrence, it becomes difficult to peel the front and back of the image receiving sheet. As a matter of course, the above-mentioned troubles may occur even when papers are used as the sheet-shaped support. It is extremely effective to form a so-called antistatic layer on the back surface of the image receiving sheet in order to prevent such problems caused by charging. The charging can be achieved by using an antistatic material or by reducing the friction coefficient between the back surface of the image receiving sheet and the heat-meltable ink image receiving layer. Therefore, the antistatic layer can be appropriately selected and formed from a wide range of materials and methods as in the case of forming the curl preventing layer. As described above, the material used for the curl prevention layer and the antistatic layer is not particularly limited. For example, as the conductive agent, a commercially available antistatic agent can be used, and fine powder such as titanium oxide or zinc oxide can be used as an impurity. It is possible to use an electronically conductive inorganic fine powder which is mixed with and fired to improve the electronic conductivity. Further, a slip agent may be added for the purpose of adjusting the friction coefficient during printing, and a fusion inhibitor may be added for the purpose of preventing block transfer of the ink ribbon even if the front and back are mistaken. . Examples of the slip agent and the anti-fusing agent include commercially available wax and silicone resin, but it is not limited to these. If necessary, pigments such as silica pigments, clay, titanium oxide, calcium carbonate, barium sulfate can be used. Regarding the filler used for the intermediate layer, the curl prevention layer, and the antistatic layer in the case of providing the above-mentioned multilayer structure, the moisture adsorption rate under the conditions of 20 ° C. and 80% relative humidity used for the heat-meltable ink image-receiving layer. Is not limited to 0.1 to 2% by weight,
Any known and conventional filler can be used.

The coating amount of the back surface coating layer is not particularly limited, but is preferably in the range of 0.1 to 10 g / m ² . When the coating amount of the back surface coating layer is in such a range, the desired sufficient effect can be exhibited, and the cost does not increase so much, which is preferable.

Although the above-mentioned curl preventing layer and antistatic layer can be individually formed on the back surface of the sheet-shaped substrate to obtain desired performance, the manufacturing process can be simplified, the manufacturing cost can be reduced, or the desired performance can be obtained. Materials, such as the functional level of the
By appropriately selecting the forming method, the object can be achieved by forming a single layer. That is, it is possible to impart trouble prevention performance such as curling prevention and antistatic prevention with a single layer. Therefore, the number of layers formed on the back surface of the sheet-shaped substrate is not particularly limited. The image-receiving sheet comprising the heat-meltable ink image-receiving layer of the present invention can be used not only for recording for melt heat transfer but also for sublimation type heat transfer recording paper, heat sensitive recording paper and the like.

The printed matter of the present invention is characterized by being obtained by using the above-mentioned melt transfer type ink image-receiving sheet. The printed matter of the present invention can provide an image-receiving sheet for thermal transfer recording having a higher heat conduction efficiency and good heat insulation property than ever before, and thus an excellent image rich in gradation can be obtained more than ever before, and a small amount. It is excellent in that a transferred image with high color density can be obtained by the heat energy of. In addition, by using the image-receiving sheet of the present invention formed of an environment-friendly material that does not adversely affect the environment that does not contain any organic solvent or organic gas component, the application to contact the human body such as advertisements / signboards, posters, leaflets, etc. One of the advantages is that the printed matter with high safety can be provided.

[0038]

EXAMPLES The present invention will be described more specifically below with reference to examples and comparative examples. In the following, all parts and% are based on weight unless otherwise specified.

Example 1 The surface of a woodfree paper having an average particle size of 16 nm was surface-treated with trimethylsilane on a surface of a woodfree paper of 85 g / m ^{2 having} a moisture adsorption rate of 0.7% by weight at 20 ° C. and a relative humidity of 80%. 15 parts of a certain inorganic hydrophobic silica was dispersed by a homogenizer together with 100 parts of a general-purpose styrene / butadiene copolymer emulsion (containing 50% of resin solid content), and a blade coater was used so that the dry adhesion amount was 20 g / m ^2. The ink composition of the present invention has a heat-meltable ink image-receiving layer having a large number of fine pores to evaporate water by coating and drying at 90 ° C. for 3 minutes to form voids. Sheet 1 was obtained. Table 1 shows the state of formation of fine pores in the heat-meltable ink image-receiving layer and the evaluation results of the transferred ink image as recording performance.

Example 2 After forming a heat-meltable ink image-receiving layer having a large number of fine pores, the number of nips was 4, a metal roll temperature was 100 ° C., and a nip linear pressure was 200 k with a soft calender.
Example 1 except that the smoothing treatment was performed under the condition of g / cm.
A melt transfer type ink image-receiving sheet 2 of the present invention was obtained by the same manufacturing method as described above. The evaluation results are shown in Table 1.

Example 3 Instead of the inorganic hydrophobic silica in Example 1, an organic filler having an average particle size of 3 μm is used.
m methyl silicone powder (relative humidity 80 at 20 ° C)
A moisture transfer type image-receiving sheet 3 of the present invention was obtained by the same production method as in Example 1 except that 30 parts by weight (moisture adsorption rate at 1.2% by weight) was used. The evaluation results are shown in Table 1.

Example 4 Instead of a general-purpose styrene / butadiene copolymer emulsion, a general-purpose polyvinyl alcohol aqueous solution having a polymerization degree of 1700 (containing a resin solid content of 15%)
A melt transfer type image receiving sheet 4 of the present invention was obtained by the same manufacturing method as in Example 1 except that 330 parts were used. The evaluation results are shown in Table 1.

Example 5 By the same preparation method as in Example 1 except that 143 parts of a water dispersion type polyurethane resin (containing 35% of resin solid content) was used in place of the general-purpose styrene / butadiene copolymer emulsion. A melt transfer type image receiving sheet 5 of the present invention was obtained. The evaluation results are shown in Table 1.

Comparative Example 1 An inorganic hydrophilic silica having an average particle size of 12 nm and a water adsorption rate of 4% by weight at 20 ° C. and 80% relative humidity was used in place of 15 parts of the inorganic hydrophobic silica. A melt transfer type image receiving sheet 6 was obtained by the same production method as in Example 1. The evaluation results are shown in Table 1.

Comparative Example 2 A melt transfer type image receiving sheet 7 was obtained by the same manufacturing method as in Example 1 except that the compounding amount of the inorganic hydrophobic silica was changed to 2.5 parts. The evaluation results are shown in Table 1.

Comparative Example 3 A melt transfer type image receiving sheet 8 was obtained by the same manufacturing method as in Example 1 except that the inorganic hydrophobic silica was not used. The evaluation results are shown in Table 1.

The state of formation of fine pores in the heat-meltable ink image-receiving layer and the evaluation of the transferred ink image as recording performance were carried out according to the following methods.

(1) Method for evaluating the state of formation of fine pores in the heat-meltable ink image-receiving layer The cross-section of the heat-meltable ink image-receiving layer is observed using a scanning electron microscope to confirm the state of formation of fine pores. It evaluated according to the following criteria. ◯: Many fine pores are uniformly present. Δ: Fine pores are observed, but they are not uniform, and some pores are not formed. X: Fine pores are not formed.

(2) Evaluation Method of Recording Performance (Evaluation of Transfer Ink Image) With respect to the melt transfer type ink image receiving sheets obtained in the above Examples and Comparative Examples, one day and one night under the environment of 20 ° C. and relative humidity of 65%. After humidity control, thermal transfer color printer (trademark: G
6800-40J, manufactured by Mitsubishi Electric Corp., and an ink image was melt-transfer recorded on the surface thereof. The reflection density of the obtained ink transfer image was measured by a Macbeth reflection densitometer and visually evaluated as described below. In the following evaluation criteria, ◎ and ○ levels are good and suitable for practical use, but △ and × levels are insufficient,
It is not suitable for practical use if there is even one level of Δ or × during the evaluation. A. Maximum reflection density and gradation reproducibility For an ink image (black monochrome image) formed with 17 gradations, the reflection density was measured for each applied energy using a Macbeth reflection type densitometer RD-914 (trademark), and the maximum The reflection density and gradation reproducibility were evaluated. Gradation reproducibility was evaluated in four grades of ⊚, ∘, Δ, and × in the order of good reproduction. ⊚: Gradation is faithfully reproduced and is extremely excellent. ◯: Gradation is faithfully reproduced and good. Δ: Gradation reproducibility is slightly insufficient and slightly inferior. X: The gradation reproducibility is insufficient and inferior. B. Occurrence state of image horizontal stripes The image horizontal stripes generated in the scanning line direction were evaluated in four grades of ⊚, ◯, Δ, and × in the order from good ones that did not occur at all. ⊚: The image has no horizontal stripes and is excellent. ◯: There is almost no horizontal streak in the image, which is good. Δ: Horizontal image streaks were observed and slightly inferior. X: Horizontal image streaks are prominent and inferior. C. Dot reproducibility Dot reproducibility is 4 levels of ◎, ○, △, × in order from the one that is reproduced well as the gradation reproducibility by observing the ink dots transferred from the ink ribbon to the image receiving layer. It was evaluated by. ⊚: There is no dot dropout and the dot shape is excellent. ◯: There are almost no missing dots, and the dot shape is good. Δ: Missing dots were observed and the dot shape was slightly inferior, but there was no problem in practical use. X: Many dots are missing and the dot shape is inferior. D. Color sharpness Observe the sharpness of the color image.
Evaluation was made in three levels of Δ and X. ◯: Color sharpness is excellent. Δ: Color sharpness is slightly inferior. X: Remarkably inferior in color sharpness. E. Peeling state The peeling state was evaluated by observing the image formed on the image-receiving layer and grading in three grades from good one with no ink peeling in order of ◯, Δ, and x. ◯: Excellent without ink peeling. Δ: Ink peeling is recognized. X: Ink peeling is noticeable and inferior.

[0050]

[Table 1]

[0051]

According to the present invention, in a melt transfer type ink image-receiving sheet having a heat-meltable ink image-receiving layer provided on a substrate, the heat-meltable ink image-receiving layer has a relative humidity of 80% at 20 ° C.
Inorganic filler (A-1) and / or organic filler (A-) having a moisture adsorption rate in the range of 0.1 to 2% by weight.
By using a composition for a melt transfer type ink image-receiving sheet containing 2) and containing a water-soluble polymer (B-1) and / or a hydrophobic polymer emulsion (B-2) as an essential component,
Providing a heat-meltable ink image-receiving layer with excellent heat insulation and cushioning properties by using an environment-friendly material that does not adversely affect the environment without using thermally expandable capsules that generate carbon dioxide gas or organic gas As a result, it is possible to provide a melt transfer type ink image-receiving sheet capable of uniform and high-density clear image recording, and a printed matter using the image-receiving sheet.

Claims (6)

[Claims] 1. A filler at 20 ° C. and a relative humidity of 80%
Water-soluble polymer (B-1) and / or hydrophobic polymer containing an inorganic filler (A-1) and / or an organic filler (A-2) having a water adsorption rate of 0.1 to 2% by weight. A composition for a melt transfer type ink image-receiving sheet, which comprises an emulsion (B-2) as an essential component. 2. The melt transfer according to claim 1, wherein the filler is at least one selected from inorganic hydrophobic silica surface-treated with an organic silicon compound and / or silicone oil, and a hydrophobic organic filler composed of a methyl silicone resin. Composition for type ink image-receiving sheet. 3. A hydrophobic polymer emulsion (B-2)
3. The melt according to claim 1 or 2, containing at least one selected from polyurethane resins, polyacrylic acid esters, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, and acrylic acid ester-butadiene copolymers. A composition for a transfer type ink image-receiving sheet. 4. The amount of (A-1) and / or (A-2) used is the resin solid content of 1 of (B-1) and / or (B-2).
The composition for a melt transfer type ink image-receiving sheet according to any one of claims 1 to 3, which is in a range of 10 to 300 parts by weight with respect to 00 parts by weight. 5. A heat-meltable ink is obtained by applying a coating composition containing the composition for a melt transfer type ink image-receiving sheet according to any one of claims 1 to 4 as an essential component on one surface of a substrate. A melt transfer type ink image-receiving sheet, which is provided with an image-receiving layer for receiving the ink. 6. A printed matter obtained by using the melt transfer type ink image-receiving sheet according to claim 5.