JP2539883C - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of the Invention The present invention relates to a thermal transfer recording sheet that gives a matte print without gloss. B. Prior Art In recent years, thermal transfer recording for forming a transfer image on plain paper using a thermal printer, thermal facsimile or the like has been actively developed. This thermal transfer recording is easy to maintain because the mechanism of the apparatus is simple, and the cost and maintenance cost are low. Also, clear and robust recording can be performed with low energy, and the use of multicolor ink sheets makes it relatively easy. Recently, it has been widely used because color recording can be easily performed. In particular, the use of monochrome type thermal transfer recording sheets is increasing due to the spread of thermal printers and thermal facsimile machines. However, a printed image recorded by a thermal printer is generally high in glossiness. In the case of multicolor color recording, beautifulness is required in addition to the precision of recording as in fields such as graphic design and full color copying, but the glossiness of the image greatly contributes to these characteristics. On the other hand, monochrome recording has many fields such as character recording and copying. In this case, as for the readability of the printed image, the higher the glossiness, the greater the feeling of fatigue to human eyes, and this is one of the improvements in thermal transfer recording. That is, there is a strong demand for matte printing without gloss in monochrome thermal transfer recording. In such a situation, there are many known techniques for thermal transfer recording that provides matte print without gloss. For example, as in JP-A-60-11084, the surface of the base film on which the hot-melt ink layer is provided is matted by sand blasting or matted by kneading fine particles and forming a film. A method is disclosed. Also, as disclosed in Japanese Patent Application Laid-Open No. 56-14891, a method is disclosed in which a matting agent is mixed and used in a heat-meltable thermosensitive ink. Further, Japanese Patent Application Laid-Open No. Sho 60-11083 discloses a method of providing a mat layer on a base film. C. Problems to be Solved by the Invention There are various problems in the patent gazettes cited in the above prior art. For example, the method of sandblasting the surface of the base film has disadvantages in that the strength of the film itself is reduced and the cost is high. The method of kneading the fine particles to form a film has a disadvantage that the degree of matting does not increase unless many fine particles are kneaded. In addition, in a method in which a matting agent is mixed into ink, the matting agent is generally a white inorganic pigment, and a small amount of matting agent hardly produces a matting effect. There are drawbacks. Furthermore, in the method of providing a mat layer on a base film, the mat layer ink is a material composed of a binder and an inorganic pigment, and it is necessary to increase the mat depth of the mat layer in order to make the matting effect appear. There is a disadvantage that the particle size of the inorganic pigment must be increased or the amount used must be increased. D. Means for Solving the Problems The present invention solves the conventional drawbacks, and provides a thermal transfer recording sheet that gives a matte print without gloss. That is, thermal transfer recording sheet provided by the present invention, in the thermal transfer recording sheet comprising coated with a heat-fusible ink layer on one surface of a polyester film <br/> substrate, heat
The hot-melt substance, which is the main component of the meltable ink, is a polymer based on dimer acid.
A polyamide resin, and the polyamide resin has a molecular weight of less than 4,000 and a reserve amount of 4,000 to
30,000 are used in combination, and the hot-melt ink is heated between the substrate and the hot-melt ink at a temperature of 80 ° C. by the 180 ° peel adhesion strength test method specified in JISK6854.
) Having an adhesive force (g / 25 mm) of 50 to 500 g / 25 mm, and causing the heat-fusible ink to undergo cohesive failure when the thermal transfer recording sheet is separated from the image receiving paper after thermal transfer. It is assumed that. A heat-meltable ink layer is applied on one side of the polyester film base.
In a thermal transfer recording sheet coated with
Soluble fusible material is a saturated polyester resin, the molecular as saturated polyester resin
Two types consisting of less than 3,000 and a molecular weight of 3,000-25,000, and specified in JISK6854.
The hot-melt ink was used for the base material and the hot-melt ink according to the 180 ° peel adhesion strength test method specified.
Adhesive strength (g / 25mm) consisting of 50-500g / 25mm when hot (80 ℃) with fusible ink
When the thermal transfer recording sheet is separated from the image receiving paper after the thermal transfer, the thermal fusibility
The ink is characterized by causing cohesive failure. In the formulation of the heat-fusible ink, the heat-fusible substance is 10 to 80 parts by weight of a polyamide resin having a molecular weight of less than 4,000 and 10 to 60 parts by weight of a polyamide resin having a molecular weight of 4,000 to 30,000.
It is a combination of two kinds of parts by weight. In addition, in the blending of the hot-melt ink, the hot-melt substance has 10 to 60 parts by weight of a saturated polyester resin having a molecular weight of less than 3,000 and 10 to 50 parts by weight of a saturated polyester resin having a molecular weight of 3,000 to 25,000. It is characterized by being used in combination. Further, the printed image obtained by thermal transfer recording by combining the thermal transfer recording sheet and the image receiving paper is converted to a 60 ° specular gloss (hereinafter referred to as “specular gloss”) according to the specular gloss measurement method defined in JISZ8741.
This is characterized in that the image is a mat-tone print image of 30 or less . Below, the present invention will be described in detail. The thermal transfer recording sheet of the present invention is formed by coating a heat-fusible ink layer on one surface of a base material, and when printed using a thermal head in combination with an image receiving paper, matte matte printing on the image receiving paper. Gives an image. That is, the purpose of the thermal transfer recording sheet of the present invention is to provide matte printability without gloss. In the present invention, it is considered that the state at the interface between the heat-fusible ink applied to the base material and the base material is related to the heat transfer recording sheet in order to achieve the above object. In the case of ordinary thermal transfer recording, the heat-fusible ink applied to a base material is completely peeled off from the base material and transferred to an image receiving paper. In this case, since the base material generally has a highly smooth surface such as a mirror surface, the printed image transferred to the image receiving paper reflects the surface condition of the base material and becomes glossy. The purpose of obtaining a matte printability by utilizing this concept is the method of providing a mat layer on a base material according to the above-mentioned Japanese Patent Application Laid-Open No. 60-11083. Here, a mat-like print is given by reproducing the state of the mat layer on the surface of the print image. In contrast to such a method, in the present invention, when the thermal transfer recording sheet is separated from the image receiving paper after thermal printing, complete peeling is performed between the substrate surface of the thermal transfer recording sheet and the heat-fusible ink. The matte tone is obtained by causing the heat-fusible ink itself to undergo cohesive failure (breaking and peeling between the thermal transfer recording sheet and the image receiving paper) without causing the surface of the transferred printed image to be broken and peeled. Here, the breaking peeling that occurs between the thermal transfer recording sheet and the image receiving paper depends on the adhesive force between the base material and the hot-melt ink. The adhesive strength is expressed in g / 25 mm by a measuring method based on a 180 ° peel adhesive strength test method specified in JISK6854. 180 ° peel adhesion strength test method
130-180 g / m2 of the hot-melt material is applied to the base material, and the test pieces are stuck together on the coated surface. Then, a load of 5 kg is applied by using a hand roller, and 5 kg is applied so as not to reciprocate in the length direction. After repeated pressure bonding, the film is left at room temperature for 48 hours and then peeled 180 ° at a moving speed of 200 ± 20 mm / min using a load cell type peeling tester. In the present invention, the measurement is performed in accordance with the above-described test method.Specifically, a hot-melt ink is applied on a substrate, and the coated surface and an uncoated equivalent substrate are applied. After laminating under heat, apply pressure of a specified amount and crimp, and leave at 120 ° C for 10 minutes. After bonding, the mixture was left at room temperature for 10 minutes, and slit into a 25 mm width to be used as a test piece. Using such a test method, when the heat-fusible ink in the thermal transfer recording sheet of the present invention has an adhesive force between 50 and 500 g / 25 mm in the range of 50-500 g / 25 mm when heated (80 ° C.), The inventive matte print with no gloss can be provided. When the adhesive strength is within the specified range, the cohesive failure of the ink itself occurs between the substrate and the hot-melt ink as described above. The main material of the hot-melt ink is basically a hot-melt substance for controlling the adhesive force. A heat-fusible substance having a high adhesive strength to a substrate is suitable for the purpose of the present invention, but in the present invention, a polyamide resin and a saturated polyester resin based on dimer acid are particularly preferred. These have an adhesive force with the base material, and the adhesive force increases as the molecular weight increases. However, in the present invention, if the adhesive force is too high, the effect of thermal transfer recording is hindered. In particular, those having a high adhesive force have a large molecular weight, a high softening point and a high melt viscosity. In the hot melt material of the present invention, the polyamide resin has a molecular weight of less than 4,000 and a molecular weight of 4.0.
It is desirable to use two kinds consisting of 00 to 30,000 or two kinds consisting of a saturated polyester resin having a molecular weight of less than 3,000 and a molecular weight of 3,000 to 25,000. This can also contribute to lowering the melting point and the softening point melt viscosity of the compatible and hot-melt ink of the same resin by using two kinds of molecular weights in combination. The softening point and melt viscosity of the hot-melt ink are important factors in relation to workability in manufacturing the hot-melt ink and transferability of the thermal transfer recording sheet. By the way, the case where the adhesive strength of the hot melt ink of the present invention is out of the specified range can be explained as follows. When it is less than the lower limit and less than 50 g / 25 mm, the hot-melt ink is easily peeled from the substrate, and cohesive failure does not occur. That is, since the surface of the base material is reproduced as it is, a glossy printed image is obtained, which does not meet the purpose of the matte tone printing of the present invention. On the other hand, if it is more than the upper limit of 500 g / mm, peeling of the hot-melt ink from the substrate becomes difficult, and transferability to the image receiving paper decreases. The degree of cohesive destruction of the hot-melt ink increases, and the printed image exceeds the matte-tone printing, resulting in a state of missing characters or white spots. Incidentally, whether or not cohesive failure has occurred can be conveniently identified by examining the peeled portion of the heat-fusible ink layer of the transferred thermal transfer recording sheet. If there is cohesive failure according to the present invention, the hot-melt ink remains irregularly on the substrate. If the remaining degree is large, the transfer to the image receiving paper is small and the printability is poor, and the transfer density is low. The desired degree of residue is that, on average, a small amount is left behind on the substrate. On the other hand, when the heat-fusible ink remains on the base material to the extent that it is hardly discernable, for example, when the base material uses a transparent material such as polyester film, in this case, from the surface of the base material Is almost transferred onto the image receiving paper, and the transferred printed image becomes a glossy printed image reflecting the surface condition of the base material as it is. Subsequently, in the present invention, a print image obtained by thermal transfer recording by combining the thermal transfer recording sheet and the image receiving paper is JISZ8741
It is desirable that the image be a matte-tone print image having a 60-degree specular glossiness of 30 or less according to the specular glossiness measurement method defined in the above. When the glossiness is greater than 30, the matte print image of the present invention does not meet the intended purpose, and the user can easily visually feel fatigue. Next, the materials to be used will be described more specifically. As the base material, thin paper such as condenser paper, typewriter paper, tracing paper, synthetic paper, cellophane paper, and synthetic resin film such as polyester film, polyimide film, polyethylene film, polycarbonate film, Teflon film, etc. It is used after heat-resistant treatment so that it does not stick to the head. Of these examples, a polyester film is particularly preferred for the purpose of the present invention. As described above, the main heat-fusible substance of the heat-fusible ink in the heat transfer recording sheet of the present invention is preferably a polyamide resin or a saturated polyester resin, but various materials described below are also within the range of the adhesive force specified in the present invention. Use alone or in combination is not limited. The hot-melt ink used in the present invention is a hot-melt substance, a colorant, a binder,
Although it is composed of a softener and the like, it is used as needed when used. Representative examples of the heat-fusible substance are shown below, but are not limited thereto. Examples of waxes include plant waxes such as rice wax, wood wax, candelilla wax, carnauba wax, animal waxes such as lanolin, dense wax, whale wax, shellac wax, montan wax, ozokerite, ceresin, etc. Petroleum waxes such as mineral wax, paraffin wax and microcrystalline wax, synthetic hydrocarbon waxes such as oxidized paraffin wax and low molecular weight polyethylene, ricinoleic amide, lauric amide, erucic acid amide, palmitic acid amide, oleic acid amide And amide waxes such as stearic acid amide and ethylene bisstearic acid amide. Examples of the metal soap include metal salts of higher fatty acids such as sodium stearate, sodium palmitate, potassium laurate, potassium myristate, calcium stearate, zinc stearate, aluminum stearate, and magnesium stearate. Examples of resins include polyamide resins, polyester resins, epoxy resins, polyurethane resins, polyacrylic resins, polyvinyl resins, polyvinyl chloride resins, cellulose resins, polyvinyl alcohol resins, petroleum resins, and terpene resins. Resins, polystyrene resins, polyolefin resins, elastomers and the like can be mentioned. Colorants include dyes and pigments such as oil-soluble dyes, disperse dyes, and colored pigments, but they are used as needed. Hereinafter, specific examples will be given, but the present invention is not limited thereto, and two or more kinds may be used in combination. Examples of the oil-soluble dye include an azo dye, an azo metal complex dye, an anthraquinone dye, and a phthalocyanine dye. More specifically, examples of azo dyes include Solvent Yellow 2 (CI11020, hereinafter the parentheses indicate CI No.) Solvent Orange 1 (11920), Solvent Red 24 (26105), Solvent Brown 3 (11360), and the like. Solvent Yellow 19 as a metal complex dye
(13900A), Solvent Orange 5 (18745A), Solvent Red 8 (12715)
, Solvent Brown 37, Solvent Black 123 (12195), etc., and as anthraquinone dyes, Solvent Violet 13 (60725), Solvent Blue 11
(61525), Solvent Green 3 (61565) and the like, and phthalocyanine dyes such as Solvent Blue 25 (74350). Examples of the disperse dye include an aminoazo or aminoanthraquinone dye and a nitroarylamine dye. More specifically, examples of aminoazo dyes include Disperse Yellow 3 (CI11855, hereinafter the CI number is shown in parentheses), Disperse Orange 3 (11005), Disperse Red 1 (11110), Disperse Violet 24 (11200). , Disperse Blue 44 and others. Examples of the aminoanthraquinone dye include Disperse Orange 11 (60700), Disperse Red 4 (60755), Disperse Violet 1 (61100), Disperse Blue 3 (61505), and the like. Nitroarylamine dyes include Disperse Yellow 1 (10345) and 42
(10338). Colored pigments include azo pigments (monoazo, bisazo, condensed azo pigments), dye lake pigments (acid dye lakes, basic dye lakes, mordant dye lake pigments), nitro pigments, nitroso pigments, phthalocyanine pigments, and high-grade pigments (vat dyes). Dye-based pigments, metal complex pigments, perylene pigments, isoindolinone pigments, quinacridone pigments, and the like. More specifically, Hanzo Yellow G is used as an azo pigment.
(CI11680, hereinafter the parentheses indicate CI No.), Hansa Yellow R (12710), Pyrazolone Red B (21120), Permanent Red R (12085), Lake Red C
(15585), Brilliant Carmine 6B (15850), Permanent Carmine FB (1249
0) (above monoazo pigment), benzidine yellow G (21090), benzidine yellow GR
(21100), permanent yellow NCR (20040) (above bisazo pigment), chromophtal yellow, chromophtal red (above condensed azo pigment) and the like. As dye lake pigments, quinoline yellow lake (47005), eosin lake (45380),
Alkaline Blue Lake (42750A, 42770A) (acid dye lake pigment), Rhodamine Lake B (45170), Methyl Violet Lake (42535), Victoria Blue Lake (44045), Malachite Green Lake (42000) (basic dye lake pigment) ), Alizarin Lake (58000) (mordanting dye lake pigment). As nitro pigments, naphthol yellow S (10316), as nitroso pigments, Pigment Green B (10006), naphthol green B (10020), and as phthalocyanine pigments, metal-free phthalocyanine blue (74100), phthalocyanine blue (74160)
), Phthalocyanine green (74260) and the like. High-grade pigments include Anthrapyrimidine Yellow (68420) and Indanthrene Brilliant Orange GK (59305)
), Indaslen Blue RS (69800), Thioindigo Red B (73300) (Vatable dye-based pigment), Nickel Azo Yellow (12775) metal complex salt pigment), Perylene Red (71140), Perylene Scarlet (71137) (More Perylene pigment), isoindolinone yellow (isoindolinone pigment), quinacridone red Y (46500),
There is quinacridone magenta (73915). As a black pigment, there is carbon black (CI77265). As the binder, any of a water-soluble binder and a water-insoluble binder can be used. Specific examples of such a binder will be described below, but the present invention is not limited thereto, and two or more binders may be used in combination. As the binder, for example, polyvinyl alcohol, methyl cellulose, gelatin, hydroxyethyl cellulose, carboxymethyl cellulose, gum arabic, starch and derivatives thereof, casein, polyvinyl pyrrolidone, butyral resin, ethylene ethyl acrylate, styrene-butadiene copolymer, vinyl acetate resin, Examples thereof include a vinyl acetate copolymer, an acrylic resin, a methyl methacryl resin, a styrene / acrylonitrile resin, an ethylene-vinyl acetate copolymer, a polyester resin, and a petroleum resin. Examples of the softener include mineral oil, dibutyl phthalate, dioctyl phthalate, mineral spirit, and liquid paraffin. In addition to the above-mentioned heat-fusible substances, colorants, binders and softeners, additives such as surfactants, dispersants, antistatic agents, antioxidants, and ultraviolet absorbers may be added. Coating machines used for coating the hot-melt ink of the present invention on a substrate include known coaters such as a hot melt coater, an air knife coater, a roll coater, a blade coater, a bar coater, and a flexo method. A known printing machine using a gravure method or the like can also be used. In addition, about solvent coating, it is possible with a general solvent, for example, methanol,
Ethanol, isopropyl alcohol, toluene, methyl ethyl ketone, acetone, ethyl acetate and the like can be appropriately used. The coating thickness of the hot-melt ink layer is 1 to 15 μm, preferably 2 to 10 μm, and more preferably 3 to 6 μm. E. Function The thermal transfer recording sheet of the present invention is obtained by coating a heat-fusible ink layer on one surface of a substrate, and is used to bond a heat-fusible ink by a 180 ° peel adhesion strength test method specified in JISK6854. It is characterized in that the force is between 50 and 500 g / 25 mm when heated (80 ° C.) between the substrate and the hot-melt ink. Further, as a main component of the heat-meltable ink, the heat-meltable substance is composed of a polyamide resin based on dimer acid, and two kinds of polyamide resins having a molecular weight of less than 4,000 and a molecular weight of 4,000 to 30,000 are used in combination or a saturated polyester resin. And two types of saturated polyester resins having a molecular weight of less than 3,000 and 3,000 to 25,000 are used in combination. The thermal transfer recording sheet of the present invention having such features has an effect that a matte print image without gloss can be obtained by thermal transfer recording in combination with an image receiving paper. Hereinafter, the present invention will be described specifically with reference to examples. In addition, "part" in an Example shows a weight part. F. Examples Example 1 A hot-melt ink was produced using a sand mill with the following composition of a polyamide resin having a molecular weight of 1000 and a molecular weight of 5,000 on the uncoated surface of a 5.4 μm-thick polyester film provided with a heat-resistant layer. Then, coating was performed with a hot melt coater to a thickness of 4 μm to obtain a thermal transfer recording sheet. Polyamide resin (molecular weight 1000) 30 parts Polyamide resin (molecular weight 5000) 30 parts Stearic acid amide (melting point 100 ° C) 30 parts Carbon black 10 parts The thermal transfer recording sheet obtained in this manner is used as a receiving paper (Mitsubishi Paper Corp. product). Name TT
R-T) and a printing tester (Matsushita Electronic Components Co., Ltd. thermal head printer)
Was used to perform a character pattern and solid printing at an applied energy of 1.2 mJ / dot. When the image receiving paper and the thermal transfer recording sheet were peeled off, it was confirmed that the heat-fusible ink remained in the thermally printed corresponding portion of the thermal transfer recording sheet and caused cohesive failure. or,
The adhesive strength (g / 25mm) between the substrate of the thermal transfer recording sheet and the heat-meltable ink is JISK
Measured according to the 180 ° peel adhesion strength test method specified in 6854, 181 g / 25 mm
Have gained. In addition, solid printing and character patterns on the image receiving paper were able to obtain matte printing without gloss. Furthermore, for solid printing, a 60-degree specular gloss measured by the specular gloss measurement method specified in JISZ8741 is used as a gloss meter (trade name: VGS-1001DP, manufactured by Nippon Denshoku Industries Co., Ltd.).
Was 11.5. Example 2 A thermal transfer recording sheet was produced in the same manner except that the polyamide resin used in Example 1 was changed to those having a molecular weight of 1,000 and a molecular weight of 10,000. The evaluation results obtained in the same manner as in Example 1 are shown in Table 1. Comparative Example 1 A thermal transfer recording sheet was produced in the same manner as in Example 1 except that the polyamide resin having a molecular weight of 1,000 was used alone, and the polyamide resin having a molecular weight of 1,000 was used, except that the molecular weight of the polyamide resin was 5,000. The evaluation results are shown in Table 1. Example 3 A polyamide resin having a molecular weight of 2,000 and a molecular weight of 8,000 was dissolved in isopropyl alcohol on an uncoated surface of a 5.4 μm-thick polyester film provided with a heat-resistant treatment layer,
A hot-melt ink was manufactured according to the following formulation, and the thickness was 4 μm using a gravure coater.
Thus, a thermal transfer recording sheet was obtained. Polyamide resin (molecular weight 2000) 20 parts Polyamide resin (molecular weight 8000) 40 parts Microcrystalline wax (melting point 70 ° C) 30 parts Carbon black 10 parts Isopropyl alcohol 200 parts The thermal transfer recording sheet thus obtained was the same as in Example 1. The results are shown in Table 1. Example 4 A polyamide resin was produced and evaluated in the same manner as in Example 3 except that the polyamide resin having a molecular weight of 20,000 was used instead of the molecular weight of 8000 used in Example 3. The results are shown in Table 1. Comparative Example 2 A thermal transfer recording sheet was produced in the same manner as in Example 1 except that the polyamide resin having a volume of 20,000 was used alone, and the polyamide resin having a volume of 20,000 was used, and 60 parts were used, except for the polyamide resin having a volume of 2,000 used in Example 3. Was evaluated. The results are shown in Table 1. Example 5 A hot-melt coater was prepared by using a sand mill with a polyester resin having a molecular weight of 2,000 and a molecular weight of 7000 as described below on a non-coated surface of a 5.4 μm-thick polyester film provided with a heat-resistant treatment layer. Was applied to a thickness of 4.5 μm to obtain a thermal transfer recording sheet. Polyester resin (molecular weight 2000) 40 parts Polyester resin (molecular weight 7000) 20 parts Oxidized paraffin wax (melting point 83 ° C) 30 parts Carbon black 10 parts The thermal transfer recording sheet thus obtained was evaluated in the same manner as in Example 1. The results are shown in Table 1. Example 6 A polyester resin was produced and evaluated in the same manner as in Example 5 except that the polyester resin having a molecular weight of 10,000 was used instead of the molecular weight of 7000 used in Example 5. The results are shown in Table 1. Comparative Example 3 Except for the polyester resin having a molecular weight of 7000 used in Example 5, a polyester resin having a molecular weight of 2,000 was used alone, and a thermal transfer recording sheet was produced with the following composition. Evaluation was performed in the same manner as in Example 1, and the results are shown in Table 1. Polyester resin (molecular weight 2000) 40 parts Oxidized paraffin wax (melting point 83 ° C) 50 parts Carbon black 10 parts Example 7 A 5.4 μm-thick polyester film coated with a heat-resistant treatment layer having a molecular weight of 2000 and a molecular weight of 10,000 Polyester resin is toluene / methyl ethyl ketone = 8
/ 2 solvent to prepare a heat-meltable ink according to the following formulation, and coated with a gravure coater to a thickness of 4.5 μm to obtain a thermal transfer recording sheet. Polyester resin (molecular weight: 2000) 20 parts Polyester resin (molecular weight: 10,000) 40 parts Polystyrene (melting point: 75 ° C.) 30 parts Carbon black: 10 parts The thermal transfer recording sheet thus obtained was evaluated in the same manner as in Example 1. Are shown in Table 1. Example 8 A polyester resin was produced and evaluated in the same manner as in Example 7, except that the polyester resin having a molecular weight of 25,000 was used instead of the molecular weight of 10,000 used in Example 7. The results are shown in Table 1. Comparative Example 4 A thermal transfer recording sheet was produced in the same manner as in Example 1, except that the polyester resin having a molecular weight of 25,000 was used alone, and the polyester resin having a molecular weight of 25,000 was used, except that the polyester resin having a molecular weight of 2000 was used. . The results are shown in Table 1. Evaluation method 1) Adhesion strength Adhesion strength (g / 25mm) between the substrate and the hot-melt ink when heated (80 ° C) was measured in accordance with the 180 ° peel adhesion strength test method specified in JISK6854. It was measured. In preparing the sample, the hot-melt ink was applied on the substrate, and immediately after coating, the coated surface and the uncoated substrate were bonded together, and then a specified amount of load was applied. Crimp,
Leave at 120 ° C for 10 minutes. After bonding, the mixture was left at room temperature for 10 minutes, and slit into a 25 mm width to be used as a test piece. 2) 60 degree specular glossiness The 60 degree specular glossiness measured by the specular glossiness measurement method specified in JISZ8741 is a gloss meter (
It was measured using Nippon Denshoku Industries Co., Ltd., trade name: VGS-1001DP). The image receiving paper (Mitsubishi Paper Corp., trade name: TTR-T) and the thermal transfer recording sheet are superimposed and solid-printed by a printing tester (Matsushita Electronic Components Co., Ltd., thermal head printer). A solid printing portion was used. 3) Printability The character pattern printed on the image receiving paper and the solid print portion were visually observed. The results were represented by ○ and × as follows. ：: Gives clear printability without white spots and blurring. ×: Many white spots and blurring. 4) Cohesive failure The peeled portion of the heat-fusible ink on the thermal transfer recording sheet solid-printed on the image receiving paper is visually observed, and the state in which the heat-fusible ink remains is regarded as cohesive failure “Yes” and the transparent state. The state in which no residue was obtained was indicated as "no cohesion failure". In Examples 1 to 8, the adhesive strength (g / 25 mm) of the polyamide resin and the polyester resin which are heat-meltable substances, when two kinds of resins having different molecular weights were used together.
Are within the range of the present invention, and the glossiness is also within the range of 30 or less, giving a matte print image without gloss. In addition, all have caused cohesive failure. On the other hand, in Comparative Example 1, the adhesive strength was low, the value of glossiness was 65.7, and a glossy printed image was shown. This does not cause cohesive failure, although the printability is improved. In Comparative Example 2, since a polyamide resin having a low molecular weight was not used, it had a high adhesive strength and caused cohesive failure, but had large white spots and blurring in printability. In Comparative Example 3, only a polyester resin having a low molecular weight was used, but the adhesive strength was low and no cohesive failure occurred. Although the printability is preferable, it gives a glossy print image and is not suitable for the purpose of the present invention. In Comparative Example 4, although a polyester resin having a large molecular weight was used, the adhesive force was extremely increased, the cohesive failure was large, and almost no image was transferred to the image receiving paper. On the other hand, the glossiness is within the range of the present invention, but the printability is poor, and it is not suitable as a thermal transfer recording sheet. Examples 9 to 12 In the same manner as in Example 1, a thermal transfer recording sheet was produced using a heat-fusible ink having the following composition and evaluated. The results are shown in Table 2. Example 9 Polyamide resin (molecular weight 2000, melting point 89 ° C) 10 parts Polyamide resin (molecular weight 5000, melting point 107 ° C) 60 parts Lauric amide (melting point 80 ° C) 20 parts Carbon black 10 parts Example 10 Polyamide resin (molecular weight 2000, melting point 89 ° C) 80 parts Polyamide resin (Molecular weight 20,000 melting point 105 ° C) 10 parts Carbon black 10 parts Example 11 Polyester resin (Molecular weight 2000 melting point 83 ° C) 10 parts Polyester resin (Molecular weight 7000 melting point 110 ° C) 50 parts Oxidized microcrystalline wax (Melting point 77) ℃) 30 parts carbon black 10 parts Example 12 polyester resin (molecular weight 2000 melting point 83 ℃) 60 parts polyester resin (molecular weight 25000 melting point 113 ℃) 10 parts oxidized microcrystalline wax (melting point 77 ℃) 20 parts carbon black 10 parts In Example 9-12, the heat-fusible substance (polyamide resin or
(Polyester resin), the blending ratio of the hot-melt ink was within the range of the upper limit or the lower limit of the present invention. As can be seen from Table 2, Examples 9 to 12 are also suitable for the purpose of the present invention in each of the evaluation items of adhesive strength (g / 25 mm), 60 ° specular gloss, printability, and cohesive failure. G. Effects of the Invention As described above, the thermal transfer recording sheet of the present invention has a lower glossiness of a printed image as compared with a conventional thermal transfer recording sheet, has excellent matte printability, and has extremely high industrial significance. is there.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are views showing the structure of a thermal transfer recording sheet of the present invention. In addition,
FIG. 1 is a configuration diagram in which a heat-resistant treatment layer is provided on the opposite surface of the base material, and FIG. 2 does not include a heat-resistant treatment layer. FIGS. 3 and 4 are diagrams showing the configuration when the image is transferred onto an image receiving paper using a thermal head. FIG. 3 shows the matte print image of the present invention, and FIG. FIG. 3 is a configuration diagram for giving a glossy print image.

Claims (1)

[Claims] 1. Heat transfer by coating a heat-meltable ink layer on one side of a polyester film substrate
In the recording sheet, the heat-fusible substance which is a main component of the heat-fusible ink is made of a polyamide resin based on dimer acid, and the polyamide resin has a molecular weight of
Uses two types consisting of less than 4,000 and molecular weight of 4,000 to 30,000, and specified in JISK6854
According to the 180 ° peel adhesion strength test method, the heat-fusible ink is
It has an adhesive strength (/ 25mm) consisting of 50 to 500 / 25mm when heated (80 ° C) with a hydrophilic ink,
In addition, when the thermal transfer recording sheet is separated from the image receiving paper after thermal transfer, the thermal fusible ink is used.
A thermal transfer recording sheet characterized by causing cohesive failure . 2. Heat transfer by applying a hot-melt ink layer on one side of a polyester film substrate
In shoot recording sheet, consisting mainly composed thermally fusible substance is a saturated polyester resin is of the heat-meltable ink, a combination of two or consisting of molecules 3,000 and less than the molecular weight weight 3,000～25,000 as saturated polyester resin, and in JISK6854 180 ° peeling specified
According to the peel adhesion strength test method, the hot-melt ink is placed between the substrate and the hot-melt ink.
With hot (80 ° C) adhesive strength (g / 25mm) consisting of 50-500g / 25mm, and also thermal transfer
When the thermal transfer recording sheet is later separated from the image receiving paper, the heat-fusible ink causes cohesive failure.
A thermal transfer recording sheet characterized by being raised . 3.In the formulation of the heat-fusible ink, the heat-fusible substance is 10 to 80 parts by weight of a polyamide resin having a molecular weight of less than 4,000 and 10 to 80 parts by weight of a polyamide resin having a molecular weight of 4,000 to 30,000.
2. The thermal transfer recording sheet according to claim 1, wherein the thermal transfer recording sheet is used in combination of two kinds in which the amount is up to 60 parts by weight. 4. In the blending of the heat-fusible ink, the heat-fusible substance has 10 to 60 parts by weight of a saturated polyester resin having a molecular weight of less than 3,000 and 10 to 50 parts by weight of a saturated polyester resin having a molecular weight of 3,000 to 25,000. 3. The thermal transfer recording sheet according to claim 2 , wherein the thermal transfer recording sheet is used in combination. 5.The printed image obtained by thermal transfer recording by combining the thermal transfer recording sheet and the image receiving paper is a matte printed image having a mirror glossiness of 60 degrees or less by a mirror glossiness measurement method defined by JISZ8741 of 30 or less. claim 1 or 2 thermal transfer recording sheet according.