JPH09327979A - Receptor paper for melt type thermal transfer recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a receptor paper for melt type thermal transfer recording capable of obtaining recorded images with a good transferring property, reproductivity, and high grade and high quality without fouling whitened parts at a print starting period and recorded images with respect to a receptor paper used in a melt type thermal transfer method. SOLUTION: The receptor paper for melt type thermal transfer recording is provided with an ink receptor layer consisting mainly of an adhesive and pigment on the base paper, and the receptor layer contains a lubricant consisting at least one kind selected from higher fatty acid compounds of carbon numbers 12-21 with a wet index of 32-40(dyn/cm) on the basis of JIS K 6768 relative to the pigment by 5-60wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melting type thermal transfer recording receiving paper (hereinafter simply referred to as a receiving paper) utilizing a thermal melting ink type thermal transfer recording system, and particularly in a full color recording system, a blank portion and a recording area. The image is clean,
The present invention relates to a receiving paper which is excellent in ink acceptability and dot reproducibility and has a high recorded image quality.

[0002]

2. Description of the Related Art With the progress of office automation in recent years, copying machines, printers, facsimiles and the like using various recording systems such as electrophotographic systems and thermal transfer recording systems have come to be widely used according to their respective applications. ing. A colored coloring material is used for this image formation, and usually, the coloring material is melted, evaporated and sublimated and transferred onto a recording medium such as a paper or film sheet, and the recorded image is formed by adhesion, adsorption or dyeing. It has gained.

In this type of recording system, the ink ribbon or ink sheet having a heat-meltable ink layer is melted by the heat generated by the thermal head, and the coloring material is transferred to the recording medium to obtain a recorded image. Recently, the thermal transfer recording method has been attracting attention. This system is characterized in that plain paper can be used as the recording receiving paper.

However, in this thermal transfer recording system as well as other recording systems, full color recording, high speed recording, clear image recording,
The demand for higher resolution has increased, and plain paper is no longer satisfactory. For example, in the case of performing multicolor recording with a color thermal transfer printer or the like, a recording medium is prepared by combining a recording medium with an ink ribbon containing color materials such as yellow, magenta, cyan, and black, waxes and resins, and applying with a thermal head. A transfer image is formed on top. In the case of full-color multi-color recording, the inks of each color overlap, so if plain paper is used as the recording receiving paper, the surface smoothness of the ink receiving layer and the ink acceptability will cause defects such as uneven transfer and missing dots. Is likely to occur and becomes a difficulty.

For this reason, Beck's smoothness is specified as a method for improving the surface smoothness of recording receiving papers (Japanese Patent Laid-Open No. Sho 6-62).
No. 0-110488), a method of providing a thermal transfer receiving layer containing a specific pigment or binder (JP-A-60-11).
JP-A-0489, JP-A-60-110490) and the like are already known. However, the deterioration of image sharpness due to transfer unevenness or color misregistration in the overlapping portion of color inks in multicolor recording, missing of transfer ink dots, poor dot shape reproducibility, etc. has not been completely solved.
Therefore, it is not sufficient to simply enhance the smoothing treatment or the like to enhance smoothness or to add a pigment or a binder to the thermal transfer receiving layer.

Conventionally, in full-color recording of the melting type thermal transfer recording system, a line type thermal head is widely used because of its advantages such as high speed printing and sublimation type thermal transfer system. The head has been mainly used in the fields of label printers, monochrome printing of word processors, etc., but in recent years, along with the expansion to personal use, there has been a demand for smaller and lighter printers, lower prices, etc. A method using a serial method has been developed also in the field of full-color recording.

In the full-color recording by the above-mentioned fusion type thermal transfer recording system, in the case of a conventional receiving paper provided with an ink receiving layer containing a pigment or a binder as a main component, particularly, a blank area at the beginning of printing or a recorded image. The desired recorded image cannot be obtained due to stains on the surface. There is a strong demand for a receiving paper which can eliminate such drawbacks and is excellent in dot reproducibility and capable of obtaining a high quality and high recorded image.

[0008]

DISCLOSURE OF THE INVENTION The present invention relates to a receiving paper used in a fusion type thermal transfer recording system, in which stains do not occur even on a white paper portion or a recorded image at the beginning of printing, and ink transfer acceptability and reproducibility are obtained. Provided is a receiving paper which is excellent in fixing property, gradation property, and sharpness (without thickening of dots and bridging) and can obtain a high-quality and high-quality recorded image.

[0009]

The melting type thermal transfer recording receiving paper of the present invention is the melting type thermal transfer recording receiving paper in which an ink receiving layer containing an adhesive and a pigment as a main component is provided on a base paper. The receptive layer has a carbon number of 12 and a wetting index of 32 to 40 (dyne / cm) based on JIS K 6768.
No. 21 to 21 higher fatty acid-based compounds are included, and the lubricant is contained in an amount of 5 to 60% by weight based on the pigment. The surface tension of the melting type thermal transfer recording receiving paper of the present invention is 32.
Using the standard solution of dyne / cm, the roughness index (Vr) of the surface of the receiving layer measured by the Bristow method is 3 to 1.
5 ml / m ² and an absorption coefficient (Ka) of 0.5 to 2 and an average pore area on the surface of the receiving layer of 0.3 to 5.
It is preferably 0 μm ² and the open area ratio is 20 to 60%. Furthermore, in the melt-type thermal transfer recording receiving paper of the present invention, the pigment has an average particle diameter of 0.5 to 10 μm.
The spherical light calcium carbonate of is preferable.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have made earnest studies to achieve the above object, and as a result, provided a receptive layer containing an adhesive and a pigment as main components on a base paper, and provided a lubricant in the receptive layer. As a result, it was found that a high-quality and high-quality recorded image can be obtained by containing a certain amount of a C12-C21 higher fatty acid compound having a wetting index of 32-40 (dyne / cm). Came to do. That is, as a receiving paper used in the melting type thermal transfer recording method, a white paper portion at the beginning of printing and a recorded image are not contaminated, and the ink transfer acceptability and reproducibility are excellent, and a high-quality and high-quality recorded image can be obtained. Is. Furthermore, when the receiving paper of the present invention is used in a printer with a high applied pressure and equipped with a serial type thermal head, stains such as ink tailing occur in the blank area and the recorded image at the beginning of printing. In addition, it is excellent in ink transfer acceptance and reproducibility, and a high-quality and high-quality recorded image can be obtained.

In the present invention, the number of carbon atoms in the receiving layer is 1
Among the higher fatty acid compounds of 2 to 21, the wetting index is 3
It is characterized in that it contains a lubricant comprising at least one kind selected from higher fatty acid compounds in the range of 2 to 40 (dyne / cm), and has a wetting index of 32.
When a lubricant less than (dyne / cm) is contained in the receptor layer, the wettability of the receptor layer is too low to make it difficult for ink to adhere, and the sensitivity is greatly reduced. On the other hand, the wetting index is 40
When a lubricant exceeding (dyne / cm) is contained, the wettability of the receiving layer becomes excessive, the ink tends to adhere excessively, and the stain tends to increase.

The wetting index is measured according to JIS K 6
According to the wetting test method for polyethylene and polypropylene films described in 768. The wettability index of these films is the surface tension (dyne) of a mixed liquid which is determined to apply a series of mixed liquids having different surface tensions to the surface of the film and just wet the film.
/ Cm). The wetting index of the lubricant of the present invention is a coating liquid prepared by adding a certain amount of polyvinyl alcohol as an adhesive to an aqueous dispersion of each lubricant, coating the surface of a film support, and heating and drying under constant conditions. A uniform lubricant layer is formed on the surface of a support, and the wetting index of this surface is determined.

In the present invention, examples of higher fatty acid compounds having 12 to 21 carbon atoms used as a lubricant include stearic acid, oleic acid, linoleic acid, linolenic acid, palmitic acid, myristic acid, lauric acid, behenic acid, Higher fatty acids such as erucic acid, zinc stearate,
Higher fatty acid metal salts such as zinc behenate, calcium stearate, aluminum stearate and magnesium stearate, stearic acid amide, stearic acid bis-amide, ethylene-bis-stearic acid amide, oleic acid amide, erucic acid amide, behenic acid amide And higher fatty acid amides, and their methylol compounds. Of course, two or more kinds of these lubricants can be appropriately selected and used. Among these, stearic acid-based compounds are preferably used, and stearic acid, calcium stearate, stearic acid methylolamide, stearic acid bis-amide and the like are more preferably used.

In the present invention, the amount of the higher fatty acid compound added is 5 to 60% by weight based on the pigment in the receiving layer.
10 to 40% by weight is preferred. If the blending amount is less than 5% by weight, the effect of improving stains is insufficient, and stains start to occur when the temperature of the thermal head rises during continuous printing or the like. On the other hand, 6
If it exceeds 0% by weight, the improving effect is saturated and adverse effects such as sensitivity decrease, surface strength decrease, thickening, and foaming are large, which is not preferable. By the way, lubricants are generally used in the field of direct thermal recording paper as well, but their main purpose is to reduce the friction coefficient of the recording paper, and especially to prevent abrasion of the thermal head, sticking, and prevention of dust adhesion. Therefore, its addition amount is generally small.

In full-color recording, three colors or four
In order to express the color by overlapping the color inks, it is necessary to maintain the shape of the dots of the lower layer ink in the overlapped color portion as in the dot transfer property of the first color ink. That is,
In the two-color overlapping portion, the lower layer ink is also remelted when the upper layer ink is applied, so that the lower layer ink is likely to spread again in the three-dimensional direction of the receiving layer. In order to reduce the change in dot shape, it is necessary to allow the molten ink to penetrate the receiving layer. Therefore, in order to allow the melted ink having fluidity to penetrate, if the affinity for the ink on the surface of the pores and the size of the pores and the number of pores are not sufficient, the melted ink is difficult to penetrate into the receiving layer and easily spreads on the surface. Therefore, the dot shape may be deformed. Further, if the surface of the pores is not easily wetted by the molten ink, the permeability of the ink tends to decrease even if the pores are large. In order to obtain a good full-color image without stains on the white paper part due to ink, it is necessary to efficiently absorb and permeate the molten ink. Not only the material composition of the receiving layer, but also the void structure on the receiving layer surface and inside Also, it is considered that the smoothness of the surface of the receiving layer is important.

As a result of intensive studies, the inventors of the present invention have found that the affinity between a single color (first color) ink receiving layer and the molten ink is determined by the roughness index (Vr) of the surface of the receiving layer obtained by the Bristow method. Surface tension (28 to 32 dyne / c) of carnauba wax, which is related and is the main component of commonly used molten ink, at the time of melting (heating temperature 80 ° C.)
It was found that by using a standard solution having a surface tension equivalent to that of m), the measurement can be easily performed and a good correlation with dot reproducibility can be obtained. In the present invention, the roughness index (Vr) of the surface of the ink receiving layer according to the Bristow method is adjusted to a range of 3 to 15 ml / m ² when measured using a standard solution having a surface tension of 32 dyne / cm. The range of 3 to 10 ml / m ² is more preferable. When the roughness index is less than 3 ml / m ² , the surface of the receiving layer is hard to be wet with the ink, the melted ink is difficult to be transferred to the surface of the receiving layer, and the dot diameter is small. On the other hand, 15
If it exceeds ml / m ² , the surface of the receiving layer becomes extremely easy to wet with ink, the melted ink tends to spread (bleed) on the surface of the receiving layer, and the dot diameter tends to become thicker. May occur.

Further, in the case of two-color overprinting, it is necessary that the lower layer (first color) remelted ink sufficiently penetrates into the inside of the receiving layer, and mainly the pore diameter and the total number of pores of the receiving layer. In the present invention, it was found that the absorption coefficient (Ka) on the surface of the receptive layer obtained by the Bristow method is closely related to the permeability of the remelted ink into the receptive layer. It is a thing. That is, the absorption coefficient (Ka) of the ink-receiving layer measured by the Bristow method is 0.5 when the standard solution having a surface tension of 32 dyne / cm is used.
It is preferable to adjust it in the range of 2 to 2, and it is preferable to adjust the average pore area of the receptor layer surface to 0.3 to 5.0 μm ² and the open area ratio to 20 to 60%. If the absorption coefficient exceeds 2, the ink permeability tends to be high, the spread of the remelted ink becomes remarkable, and the spread of dots on the surface tends to increase. The average pore area is 0.3 μm ^2.
If it is less than 5.0 μm, the ink permeability is insufficient, while 5.0 μm ²
When it exceeds the above range, the ink easily permeates, but the unevenness of the surface becomes large, and the first color ink cannot be transferred in a stable shape (without defects, defects, etc.). Further, if the open area ratio is less than 20%, the number of pores that absorb the melted ink is small, so that the shape of the lower layer dot during stacking becomes unstable. When the open area ratio exceeds 60%, the coating film strength of the receiving layer decreases. Furthermore, the standard deviation of the pore area is
It is preferably 8 or less.

In the present invention, the values of the roughness index (Vr) and the absorption coefficient (Ka) of the surface of the receptor layer by the Bristow method are as described in J. TAPPI Paper Pulp Test Method No. 51-87, the surface tension is 32 dyne / cm with respect to the square root of the absorption time (T) at a constant pressure (0.1 MPa).
The transfer amount (V) of the standard solution of (3) to the receptor layer was measured, and the roughness index (Vr) and the absorption coefficient (Ka) were obtained from the intercept and slope of the linear portion of the absorption curve obtained by the following relational expression. V = Vr + Ka (T) ^1/2 where V is the transfer amount of the standard solution (ml / m ² ), Vr is the roughness index, Ka is the absorption coefficient (ml / m ² · ms ^1/2 ), and T Indicates the absorption time (ms). The surface tension 32
The standard solution for measuring dyne / cm is not particularly limited, but a formamide / ethylene glycol monoethyl ether mixed solution as described in JIS K 6768 is preferably used.

For the measurement of the pore area on the surface of the receptive layer, a photograph of the surface of the receptive layer was taken by a scanning electron microscope observation photograph, and the photograph thus taken was taken into an image analyzer to determine the average pore area and the open area. I asked for the rate.

As the pigment used in the receiving layer of the present invention, various pigments used in general coated paper, for example, kaolin, calcined kaolin, calcium carbonate, calcium sulfate, barium sulfate, titanium dioxide, talc, zinc oxide,
Alumina, magnesium oxide, silica, bentonite,
Examples include mineral pigments such as zeolite and sericite, polystyrene resins, urea resins, melamine resins, and acrylic resins, and it is of course possible to use two or more kinds in combination depending on quality requirements. The type and shape of the pigment affect the surface roughness (smoothness) of the receiving layer, the void structure, the heat insulating property, and the like, and the selection of the pigment is important.

Among the above-mentioned pigments, spherical light calcium carbonate is preferably used in order to adjust the opening area ratio of the surface of the receiving layer to a desired range. Among the above pigments, spherical light calcium carbonate having an average particle diameter of 0.5 to 10 μm is preferably used from the viewpoints of the amount of voids on the surface of the ink receiving layer, the oil absorption of the pigment, and the like. Good recording sensitivity can be obtained by improving transferability. When the average particle diameter is less than 1 μm, the voids in the ink receiving layer are insufficient and the ink acceptability is poor. On the other hand, 10 μm
If the value exceeds the range, the smoothness of the surface of the receiving layer is deteriorated, so that dot omission or the like is likely to occur and the recording image quality tends to be deteriorated. The spherical light calcium carbonate is preferably used in an amount of 30 to 100% by weight based on the total pigment in the receiving layer. If the amount used is less than 30% by weight, the effect of sufficiently improving the ink acceptability cannot be obtained. In order to adjust the roughness index and absorption coefficient of the receiving layer surface by the Bristow method, it is also possible to appropriately use it in combination with other pigments.

Specific examples of the spherical light calcium carbonate used in the present invention include ED-I and E manufactured by Yonejo Lime Industry Co., Ltd.
Examples thereof include D-III and ED-110, and B-1002 manufactured by Tsukumi Fine Ceramics Research Center. The spherical light calcium carbonate of the present invention generally belongs to the calcite system, is a spherical aggregate of fine particles, and is preferably a spherical aggregate of cubic fine particles having a side length of 0.05 to 0.8 μm. Here, the average particle size of the pigment is measured based on observation with an electron microscope. Regarding the oil absorption of spherical light calcium carbonate, JIS K 5101
Oil absorption, measured according to
It is about 1/100 g, which is excellent in ink acceptability of the receiving layer.

Further, in order to adjust the affinity of the pores of the ink receiving layer for the molten ink, C ₁₂ specified in the present invention is used.
To a lubricant selected from C ₂₁ higher fatty acid compounds,
Phosphoric acid esters having an aliphatic hydrocarbon group having C _{6 to} C ₂₁ carbon atoms, amine salts thereof, phosphatidylcholine derivatives such as lecithin, hydrocarbons such as polyethylene emulsions, higher alcohols such as stearyl alcohol, and funnel oils It is also possible to appropriately select and use a release agent, and it is of course possible to use two or more kinds.
The compounding amount of these release agents is preferably 3 to 60 parts by weight with respect to 100 parts by weight of the pigment.

As the adhesive used in the receiving layer, a water-soluble or water-dispersible polymer compound is used, and examples thereof include cationic starch, amphoteric starch, oxidized starch, enzyme-modified starch, and thermochemically-modified starch. , Starches such as esterified starch and etherified starch, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, natural or semi-synthetic polymer compounds such as gelatin, casein, soybean protein and natural rubber; polyvinyl alcohol, isoprene, neoprene, polybutadiene , Polybutene, polybutene, polyisobutylene, polypropylene, polyethylene and other polyalkenes, vinyl halides, vinyl acetate, styrene, (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylamide, vinyl vinyl ether, etc. polymerization And copolymers, synthetic rubber latex such as styrene-butadiene type, methyl methacrylate-butadiene type, polyurethane resin, polyester resin, polyamide resin, olefin-maleic anhydride resin, synthetic polymer compound such as melamine resin, and the like. . Among these, one kind or two or more kinds are appropriately selected and used according to the quality target of the receiving paper.

In the receiving layer, the blending ratio of the adhesive component is in the range of 5 to 40% by weight based on the pigment component. Incidentally, if it is less than 5% by weight, there is a problem that the surface strength of the receptive layer is weak and a dot-shaped defect occurs. On the other hand, when it exceeds 40% by weight, the voids such as pigments are filled, so that the acceptability of the ink is lowered and the recording sensitivity tends to be lowered.

In addition to these, various auxiliary agents such as a surfactant, a pH adjusting agent, a viscosity adjusting agent, etc. may be contained in the coating liquid for the receiving layer.
Softening agents, gloss imparting agents, waxes, dispersants, flow modifiers, anti-static agents, stabilizers, antistatic agents, cross-linking agents, sizing agents, optical brighteners, coloring agents, UV absorbers, defoaming agents. A water-proofing agent, a plasticizer, an antiseptic, a fragrance, etc. can be appropriately used if necessary.

The coating amount of the coating composition coating liquid is selected according to the purpose of use of the receiving paper of the present invention, but generally, the extent to which the fibers on the surface of the base paper are completely covered is selected. It is necessary, and the dry weight is preferably 6 to 30 g / m ² per side. As a coating method for forming the receiving layer, generally known coating equipment, for example, blade coater, air knife coater, roll coater, reverse roll coater, bar coater, curtain coater, die slot coater, gravure coater, champlex coater, brush coater. A two-roll or metering blade type size press coater, bill blade coater, short dwell coater, gate roll coater, or the like is appropriately used. These devices are used in conventional manner as on-machine coaters or off-machine coaters.

In forming the receiving layer, 1
It is also possible to have a layer, or a multilayer structure of two or more layers as required. In the case of a multi-layered structure, the coating liquids do not have to be the same, and may be appropriately adjusted and blended according to the required quality level, and are not particularly limited. It is also possible to provide a synthetic resin layer, a coating layer composed of a pigment and an adhesive, an antistatic layer, etc. on the back surface of the support to impart curl prevention, printability, paper feedability and the like. Further, it is of course possible to add various properties to the back surface of the support, for example, post-processing such as adhesion, magnetism, flame retardancy, heat resistance, water resistance, oil resistance, anti-slip, to add the suitability for use.

The receiving paper of the present invention is finished by adjusting the water content to 3 to 10% by weight, more preferably 4 to 8% by weight after the usual drying step and before the surface treatment step.
The smoothing treatment is generally performed by a known smoothing device, and when the smoothing treatment is performed on the surface of the receiving layer, the JIS
Beck's smoothness according to P 8119 is 300-200.
It is preferably adjusted to 0 seconds (10 ml), and a high-quality recorded image desired by the present invention can be obtained. If the Beck's smoothness is less than 300 seconds, the transferability of the ink may be reduced, the reproducibility of the image may be reduced due to missing dots, and the ink ribbon may be rubbed with the surface of the receiving layer to stain the white paper portion. is there. On the other hand, if it exceeds 2000 seconds, a paper feed failure may occur, or voids formed by pigment or the like may decrease due to excessive smoothing treatment, and ink acceptability may deteriorate.

The filler to be blended in the base paper used in the present invention is not particularly limited, but for example, talc, kaolin, clay, calcined kaolin, deramikaolin, heavy calcium carbonate, light calcium carbonate, Minerals such as magnesium carbonate, titanium dioxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, magnesium sulfate, magnesium silicate, calcium sulfate, calcium silicate, white carbon, aluminosilicate, silica, sericite, smectite, etc. Examples of the filler include organic fillers such as quality fillers, polystyrene resin fine particles, urea formalin resin fine particles, and fine hollow particles, and the fillers contained in used paper, broken paper, etc. can be recycled.

In addition to pulp fibers and fillers, various amounts of anionic, nonionic, cationic or amphoteric substances that have been conventionally used in the paper stock are used as long as the desired effects of the present invention are not impaired. Internal retention aids for papermaking such as retention aids, drainage improvers, paper strength enhancers and internal sizing agents are appropriately selected and used as necessary. In addition, dye, optical brightener, pH
Internal additives for papermaking such as a regulator, an antifoaming agent, a pitch control agent, and a slime control agent are appropriately added according to the purpose of the paper.

The papermaking method is not particularly limited. For example, an acidic papermaking method having a papermaking pH of about 4.5, an alkaline filler such as calcium carbonate as a main component, and a papermaking method
It can be applied to all papermaking methods, such as the so-called neutral papermaking method in which H is weakly acidic to about 6 to weakly alkaline to about 9, and the paper machine is also a Fourdrinier paper machine, a twin wire paper machine, a round net paper machine. ,
Yankee paper machine can be used appropriately.

If necessary, the surface is sized with an aqueous adhesive or an aqueous adhesive containing a filler. Examples of the water-based adhesive include the same adhesives as those used in the above-mentioned receiving layer, and one or two or more kinds are appropriately selected and used according to the quality target of the receiving paper.
Also, the filler is not particularly limited,
Mineral filler similar to the filler blended in the base paper described above,
Organic synthetic fillers and the like may be mentioned, and one or more of them may be appropriately selected and used according to the quality target of the receiving paper.

[0034]

The present invention will be described in more detail below with reference to examples, but of course the present invention is not limited to these ranges. In addition, "parts" and "%" in the examples mean "parts by weight of solid content" and "% by weight" unless otherwise specified.

Example 1 [Preparation of base paper] LBKP (freeness = 480 ml) 1
20 parts of talc as a filler in 00 parts of pulp slurry,
1.5 parts of rosin emulsion size and 2 parts of sulfuric acid band were added, and the mixture was diluted with white water to a pH of 5.
3. A paper stock having a solid content concentration of 1.1% was prepared. Paper is made from this stock using a Fourdrinier paper machine, and then oxidized starch with a solid content of 8% (trade name: Ace A, manufactured by Oji Corn Starch)
Using an aqueous solution, a dry press was applied with a size press device so that the dry weight would be 4.0 g / m ² , dried, and smoothed with a machine calender to a Beck smoothness of 80 seconds. A base paper having a basis weight of 97 g / m ² was obtained. [Preparation of Receptor Layer Coating Liquid] Pigment having an average particle size of 3.
0 μm spherical light calcium carbonate (trade name: ED-III
, Yonejo Lime Industry Co., Ltd.) 100 parts (solid content; same below)
Using sodium polyacrylate as a dispersant (trade name:
Aron T-40, manufactured by Toagosei Co., Ltd.) (0.5 parts, solid ratio to the pigment; the same applies hereinafter) was added, and the mixture was dispersed in water using a Choles disperser to prepare a pigment slurry. To this pigment slurry, 15 parts of polyvinyl alcohol, 1 part of styrene-butadiene copolymer latex, and calcium stearate as a lubricant (trade name: SN coat 284, manufactured by San Nopco,
Wetting index 34 (dyne / cm)) (15 parts) was added and stirred, and water was further added to prepare a coating liquid having a solid content concentration of 50%. [Preparation of Receiving Paper] The prepared coating liquid was applied to one surface of the above-mentioned base paper using a bar coater so that the dry weight was 15 g / m ^2, and dried so that the water content was 7%. A receiving layer was formed and further smoothed with a super calendar to obtain a receiving paper having Beck smoothness of 800 seconds.

Example 2 In the preparation of the coating liquid for the receptor layer of Example 1, the pigment was spherical light calcium carbonate having an average particle diameter of 5.0 μm (trade name: B-0502, manufactured by Tsukumi Fine Ceramics Research Institute) 70. Parts and 30 parts of calcined clay having an average particle diameter of 0.3 μm (trade name: Ansilex 93, manufactured by Engelhard, amorphous), and calcium stearate as a lubricant (trade name: SN coat 284, manufactured by San Nopco, A receiving layer was formed in the same manner as in Example 1 except that the addition amount of wetting index 34 (dyne / cm) was changed to 30 parts,
Further, smoothing treatment was carried out with a super calendar to obtain a receiving paper having Beck's smoothness of 600 seconds.

Example 3 In the preparation of the coating liquid for the receiving layer of Example 1, the pigment was used as spherical light calcium carbonate having an average particle size of 1.5 μm (trade name:
ED-071002-3, manufactured by Yonejo Lime Industry Co., Ltd., and changed to 100 parts, and the lubricant was methylolamide stearate (trade name: Hydrin D-757, manufactured by Chukyo Yushi Co., Ltd., wetness index 3).
6 (dyne / cm)) was changed to 30 parts to form a receiving layer in the same manner as in Example 1 and further smoothed with a super calendar to obtain a receiving paper having Beck smoothness of 1800 seconds.

Example 4 In the preparation of the coating liquid for the receptor layer of Example 1, the pigment was used as spherical light calcium carbonate having an average particle size of 10 μm (trade name: B
-1002, manufactured by Tsukumi Fine Ceramics Research Center) and changed to 100 parts, and the lubricant was paltimic acid amide (trade name: fatty acid amide P, manufactured by Kao Corporation, wetting index 32 (d
yne / cm)) except that the content was changed to 7 parts to form a receiving layer in the same manner as in Example 1 and smoothing treatment was carried out with a super calender to obtain a receiving paper having Beck smoothness of 400 seconds.

Example 5 In the preparation of the coating liquid for the receptor layer of Example 1, the pigment was used as spherical light calcium carbonate having an average particle size of 2.5 μm (trade name:
TP-CPC, manufactured by Okutama Industry Co., Ltd., 50 parts, and cubic light calcium carbonate having an average particle diameter of 0.4 μm (trade name: TP
-222, manufactured by Okutama Kogyo Co., Ltd., and the lubricant was changed to 50 parts by weight, and the lubricant was changed to 50 parts by weight of stearic acid (trade name: SN coat 282, manufactured by San Nopco, wet index 33 (dyne / cm)). A receiving layer is formed in the same manner and smoothed with a super calendar to obtain Beck smoothness of 1
A receiving paper of 000 seconds was obtained.

Example 6 In the preparation of the coating liquid for the receptor layer of Example 1, the pigment was columnar light calcium carbonate having an average particle size of 0.6 μm (trade name:
TP-123, manufactured by Okutama Kogyo Co., Ltd.) except that the amount was changed to 100 parts to obtain a receiving paper in the same manner as in Example 1.

Comparative Example 1 In the preparation of the coating liquid for the receptor layer of Example 1, the lubricant was zinc stearate (trade name: KW-509, manufactured by Kyosho Chemical Co., Ltd.,
A receiving paper was obtained in the same manner as in Example 1 except that the wettability index was 46 (dyne / cm) 15 parts. The recording paper was contaminated mainly in the blank area.

Comparative Example 2 In the preparation of the coating liquid for the receiving layer of Example 1, the lubricant was changed to 15 parts of carnauba wax (trade name: Cerosol-524, manufactured by Chukyo Yushi Co., Ltd., wetting index less than 30 (dyne / cm)). A receiving paper was obtained in the same manner as in Example 1 except that the above was carried out. This recording paper had thick dots in the heavy color portion, missing dots in the low energy portion of the gradation recording image, and had low sensitivity.

Comparative Example 3 In the preparation of the coating liquid for the receiving layer of Example 1, the pigment was used as spherical light calcium carbonate having an average particle diameter of 5.0 μm (trade name:
B-0502, manufactured by Tsukumi Fine Ceramics Research Institute)
Change to 100 parts, the lubricant is polyethylene paraffin wax (trade name: Nopcoat PEM17, manufactured by San Nopco,
A wetting index of 34 (dyne / cm) was changed to 15 parts to form a receptor layer in the same manner as in Example 1, and smoothing treatment was performed using a super calender to obtain Beck smoothness of 100.
A 0 second receiving paper was obtained. Light stains were observed on this recording paper.

Comparative Example 4 In the preparation of the coating liquid for the receptive layer of Example 1, the addition amount of calcium stearate (trade name: SN coat 284, manufactured by San Nopco, wettability index 34 (dyne / cm)) of 3 was used as a lubricant. A receptive layer was formed in the same manner as in Example 1 except that the parts were changed, and the surface was smoothed with a super calender.
A receiving paper having a Bekk smoothness of 600 seconds was obtained. The recording paper was slightly soiled on the blank area.

Comparative Example 5 In the preparation of the coating liquid for the receiving layer of Example 1, the addition amount of calcium stearate (trade name: SN coat 284, manufactured by San Nopco, wettability index 34 (dyne / cm)) as a lubricant was 70. A receiving layer was formed in the same manner as in Example 1 except that parts were changed, and smoothing treatment was performed using a super calender to obtain a receiving paper having Beck smoothness of 800 seconds. With this recording paper, the fine line breaks in the recorded image occurred due to the decrease in surface strength or the decrease in sensitivity.

Evaluation Method The lubricants used in Examples 1 to 6 and Comparative Examples 1 to 5 and the receiving papers obtained were evaluated by the following methods, and the results are shown in Table 1. [Wettability test] The wetting index of the lubricant is measured according to JIS K
According to the wetting test method for polyethylene and polypropylene films described in 6768. A sample for measuring the wetting index of a lubricant is prepared by adding 0.5% of polyvinyl alcohol to an aqueous dispersion of each lubricant to a lubricant solid content to prepare a coating liquid, and coating the liquid on a polyethylene film support. 80
After drying at 20 ° C. for 20 minutes, a lubricant layer having a coating film thickness of 5 μm was formed and used as a measurement sample.

[Dot Reproducibility Evaluation of Recorded Image] With respect to the above-mentioned receiving sheet, a commercially available serial thermal transfer color printer (trade name: MD-2000J, manufactured by Alps Electric Co., Ltd.) was used under the environment of 20 ° C. and 65% RH. Then, full-color image recording is performed, and for dot reproducibility, the halftone dot portion of the recorded image surface is measured by a dot analyzer (DA-3000).
The degree of dot omission and sharpness (thickness or thinness) was evaluated according to the following criteria by enlarging to 0 times. ⊚: Very good with no missing dots or thickening or thinning. ◯: There are almost no missing dots or thickening or thinning, which is good. Δ: The dots are missing or thick or thin, and slightly inferior. Poor: Many dots are missing or thick or thin, which is inferior.

[Evaluation of Quality of Recorded Image] With respect to the recorded image surface of the receiving paper on which the full color image was recorded, the quality of the recorded image was visually comprehensively evaluated according to the following evaluation criteria. ⊚: The image quality is excellent with a very clear image with no color misregistration or uneven density. ◯: The image quality is good with a clear image with almost no color misregistration or uneven density. Δ: Color misregistration and unevenness of light and shade are recognized, the image is slightly dull, and the image quality is slightly inferior. X: Color misregistration and unevenness of light and shade are recognized, and the image is not crisp and the image quality is poor.

[Evaluation of Contamination of Recorded Image] With respect to the receiving paper after recording the full-color image, the degree of contamination was visually evaluated according to the following evaluation criteria. ⊚: No stain is generated on both the blank area and the recording area at the beginning of printing. ◯: Slight stain is found only on the blank area at the beginning of printing. Δ: Stain is partially generated on the blank portion and the recording portion at the beginning of printing. X: Staining occurs on almost the entire surface of both the blank area and the recording area at the beginning of printing. In the above evaluation criteria, a level of O or higher is suitable for practical use, and a level of Δ or lower is not suitable for practical use.

Example 7 [Preparation of base paper] LBKP (freeness (CSF) = 48)
20 parts of talc as a filler, 1.5 parts of rosin emulsion sizing agent, and 2 parts of sulfuric acid band are added to 100 parts of pulp slurry (0 ml), and the mixture is diluted with white water to have a pH of 5.3 and a solid content concentration of 1. A 1% stock was prepared. This stock is made using a Fourdrinier paper machine, and then oxidized starch (trade name: Ace A, made by Oji Corn Starch) and light calcium carbonate (trade name: TP-121, made by Okutama Kogyo) are mixed (mixed). The size press solution obtained by the ratio 1: 2) is applied by a size press device so that the applied amount is 5.0 g / m ^{2 in} dry weight, dried, and smoothed by a machine calender. Beck smoothness 80 seconds, tsubo 97
A base paper of g / m ² was obtained.

[Preparation and Application of Coating Liquid for Receptor Layer] 70 parts of spherical light calcium carbonate (trade name: ED-III, Yonejo Lime Industry Co., Ltd., average particle diameter 3.0 μm), light calcium carbonate (trade name) : Univer 70, manufactured by Shiraishi Calcium Co., average particle size 2.8 μm, 10 parts, clay (trade name: UW-9)
0, manufactured by Engelhard Co., average particle size 0.2 μm) 10
Parts, calcined clay (trade name: Ansilex 90, manufactured by Engelhard Co., average particle size 0.4 μm) and 10 parts of sodium polyacrylate as a dispersant (trade name: Aron A-9,
0.5 part (manufactured by Toagosei Co., Ltd.) was added and dispersed in water using a Choles disperser to prepare a pigment slurry. To this pigment slurry, 25 parts of polyvinyl alcohol and 1 part of styrene-butadiene copolymer latex were added and stirred, and a lubricant of calcium stearate (trade name: SN Coat 284, manufactured by San Nopco) was used as an affinity modifier for pores and ink. 1
3 parts of the release agent of the emulsion which emulsified 0 parts and lecithin
Part of the solution, and then water was added to prepare a coating liquid having a solid content concentration of 40%.

[Formation of Receptor Layer] The obtained coating liquid was applied onto one surface of the above-mentioned base paper using a bar coater so that the dry weight was 15 g / m ^2, and dried to form a receptor layer, Beck smoothness of 7 after smoothing with a super calendar
A receiving paper of 00 seconds was obtained.

Example 8 In the preparation of the coating liquid for the receptor layer of Example 7, the pigment was used as spherical light calcium carbonate having an average particle size of 5 μm (trade name: B-
0502, manufactured by Tsukumi Fine Ceramics Research Center)
70 parts and clay (trade name: UW-90, manufactured by Engelhard Co., average particle size 0.2 μm) 10 parts, calcined clay (trade name: Ansilex 90, manufactured by Engelhard Co., average particle size 0.4 μm) 20 A receiving paper was obtained in the same manner as in Example 7, except that the affinity modifier was changed to 30 parts of palmitic acid amide (trade name: fatty acid amide P, manufactured by Kao Corporation).

Example 9 In the preparation of the coating liquid for the receptor layer of Example 7, the pigment was spherical light calcium carbonate having an average particle size of 2.5 μm (trade name:
TP-CPC, manufactured by Okutama Kogyo Co., Ltd., 50 parts and calcined clay having an average particle size of 0.3 μm (trade name: Ansilex 9)
3, changed to 50 parts by Engelhard Co., amorphous, and the affinity modifier is stearic acid (trade name: SN coat 282,
A receiving paper was obtained in the same manner as in Example 7 except that the amount of the receiving paper was changed to 40 parts by San Nopco.

Example 10 [Preparation of base paper] LBKP (freeness (CSF) = 48)
0 ml) 100 parts of pulp slurry with calcium carbonate as a filler (trade name: TP-121, manufactured by Okutama Kogyo Co., Ltd.)
10 parts, 1.0 part of alkyl ketene dimer sizing agent, 0.4 part of sulfuric acid band, and 1.2 parts of starch were added, and the mixture was diluted with white water to pH 6.5 and solid content concentration 1.1%. Was prepared. The stock was paper-made using a Yankee paper machine to obtain a base paper having a basis weight of 97 g / m ² .

[Preparation and Application of Coating Liquid for Receptor Layer] 60 parts of spherical light calcium carbonate (trade name: TU-5, Yonejo Lime Industry Co., Ltd., average particle size 5.0 μm) and calcined clay (product Name: Ansilex 93, manufactured by Engelhard Co., average particle size 0.4 μm, 30 parts, clay (trade name: UW-9)
0, manufactured by Engelhard Co., average particle size 0.2 μm) 10
0.5 part of sodium polyacrylate (trade name: Aron A-9, manufactured by Toagosei Co., Ltd.) was added as a dispersant to the parts, and the mixture was water-dispersed using a Choles disperser to prepare a pigment slurry. Acrylic copolymer latex (trade name:
UX-100, manufactured by Daicel Chemical Co., Ltd., 12 parts, and oxidized starch (trade name: Ace A, manufactured by Oji Corn Starch Co., Ltd.)
5 parts were added and stirred, and 9 parts of stearic acid methylolamide (trade name: Hydrin D-757, manufactured by Chukyo Yushi Co., Ltd.) was added as an affinity modifier for pores and ink, and water was further added to obtain a solid content concentration. To prepare a coating liquid of 40%.

[Formation of Receptor Layer] The obtained coating liquid was applied onto one surface of the above-mentioned base paper using a bar coater so that the dry weight was 20 g / m ^2, and dried to form a receptor layer, Beck smoothness of 7 after smoothing with a super calendar
A receiving paper of 00 seconds was obtained.

Example 11 In the preparation of the receiving layer coating liquid of Example 10, 30 parts of calcined clay (trade name: Ansilex 93, manufactured by Engelhard Co., average particle size 0.3 μm), and clay (trade name) : UW-90, manufactured by Engelhard Co., Ltd., average particle size: 0.2 μm) A receiving paper was obtained in the same manner as in Example 10 except that 10 parts were removed. However, the Bekk smoothness of the obtained receiving paper was 450 seconds.

Evaluation Method The receiving papers obtained in Examples 7 to 11 above were further evaluated by the following methods, and the results are shown in Tables 2 and 3. [Measurement of Roughness Index and Absorption Coefficient by Bristow Method] The roughness index (Vr) and absorption coefficient (Ka) of the surface of the receptor layer by the Bristow method are described in J. TAPPI Paper Pulp Test Method No. 5
It measured according to 1-87. Surface tension 32 dyne / c
The standard solution of m is formamide / ethylene glycol monoethyl ether (volume ratio = 10.5 / 89.5).
The pressure was measured at 0.1 MPa using the mixed liquid.

[Measurement Method of Average Pore Area and Open Area Ratio] For the measurement of the pore area on the surface of the receptor layer, a photograph of the surface of the receptor layer was taken using a scanning electron microscope (observation magnification: 1,000 times). Image analysis device (product name: Im
age Analyzer V10, Toyobo Co., Ltd.
The average pore area, the standard deviation of the pore area, and the open area ratio were obtained by The open area ratio is the ratio of the total area of the open area occupied by the pores to the total surface area of the ink receiving layer surface, and is calculated by the following formula. Open area ratio (%) = (total area of open area occupied by pores) / (total surface area of receiving layer) × 100

[Dot Reproducibility on Recorded Image Surface] A commercially available thermal transfer color printer (trade name: MD-
Image recording was performed by using 2000J, manufactured by Alps Electric Co., Ltd., and dot reproducibility was evaluated for the following three items. (1) Evaluation of dot dropout and chipping The above-mentioned one-color (cyan) halftone dot area of the recorded image surface is magnified 30 times with a dot analyzer (DA-5000), and the degree of dot dropout and chipping is shown below. It was visually judged according to the evaluation criteria. ⊚: Very good with no missing dots or chips. ◯: Good with almost no missing dots or chipping. Δ: Slightly inferior due to missing dots and chips. ×: Many dots are missing and defective.

(2) Collapse of Negative Part The above-mentioned one-color (magenta) halftone dot part of the recorded image surface is magnified 30 times by a dot analyzer (DA-5000),
The degree of crushing of the negative portion was visually judged by the following evaluation criteria. ⊚: Very good without crushing. ◯: Good with almost no crushing. Δ: Slightly inferior with crushing. X: Many crushes are inferior.

(3) Ink Thickening at Color Overlapping Portion Regarding the recording image surface described above, the quality of the recording image was visually evaluated comprehensively by the following evaluation criteria for the color overlapping (two colors) portion. ⊚: Excellent without the thickening (bleeding) of the first color ink. ◯: Good with almost no thickening (bleeding) of the first color ink. Δ: Thick (bleeding) of the first color ink is recognized and slightly inferior. X: Inferior because a large amount of thickening (bleeding) of the first color ink is recognized.

[Evaluation of Image Quality of Recorded Image] With respect to the above-mentioned recorded image surface, the color superimposition (three colors) portion was visually comprehensively evaluated for the quality of the recorded image based on the following evaluation criteria. ⊚: The image quality is excellent with a very clear image with no color misregistration or uneven density. ◯: The image quality is good with a clear image with almost no color misregistration or uneven density. Δ: Color misregistration and unevenness of light and shade are recognized, the image is slightly dull, and the image quality is slightly inferior. X: Color misregistration and unevenness of light and shade are recognized, and the image is not crisp and the image quality is poor.

[0065]

[Table 1]

[0066]

[Table 2]

[0067]

[Table 3]

[0068]

EFFECTS OF THE INVENTION The receiving paper of the present invention has no white spots at the beginning of printing or stains on the recorded image, has no dots missing or thickened on the recorded image surface, has excellent dot reproducibility, and is extremely clear and of high quality. A recorded image can be obtained, which is of high practical value especially for full-color recording.

Claims (3)

[Claims] 1. A melting-type thermal transfer recording receiving paper having an ink receiving layer containing an adhesive and a pigment as main components on a base paper, wherein the receiving layer has a wetting index of 32 to 40 (according to JIS K 6768). 12 carbon atoms which is dyne / cm)
No. 21 to 21 higher fatty acid-based compound, and 5 to 60% by weight of a lubricant selected from the above pigments is contained in the melt-type thermal transfer recording receiving paper. 2. The roughness index (Vr) of the surface of the receptor layer measured by the Bristow method using a standard solution having a surface tension of 32 dyne / cm is 3 to 15 ml / m ² , and the absorption coefficient (Ka) is ^{2. The} receptor for melt type thermal transfer recording according to claim 1, wherein the average pore area on the surface of the receptive layer is 0.3 to 5.0 .mu.m.sup.2, and the open area ratio is 20 to 60%. paper. 3. The pigment has an average particle diameter of 0.5 to 10 μm.
3. The melt-type thermal transfer recording receiving paper according to claim 1 or 2, which is m spherical light calcium carbonate.