JPS6151387A - Thermal transfer sheet and transfer method - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer sheet imparting high quality printing even to transfer paper inferior to surface smoothness, by providing a sealer layer to the heat-meltable ink layer provided to one surface of a base film. CONSTITUTION:A thermal transfer sheet having a sealer layer is used on the heat-meltable ink layer providing on a base film and, simultaneously with transfer, sealing treatment is applied only to the printing part of transfer paper. As the base film, a plastic film such as a usually used polyester film or papers such as condenser paper or paraffin paper are used but the polyester film is optimum. The heat-meltable ink layer is prepared by compounding carbon black with EVA, paraffin wax or carnauba wax. As the coating amount of the heat-meltable ink, a thickness of 3-8mum is proper in order to stably perform high quality printing. The sealant to be used is selected from waxes with a m.p. range of 40-150 deg.C so that said sealant is melted under heating by a thermal head and can apply sealing function to transfer paper.

Description

[Detailed description of the invention]

purpose of invention

[Industrial Application Field] The present invention relates to improvements in heat-sensitive transfer sheets and transfer methods,
More specifically, the present invention relates to a thermal transfer sheet and a transfer method that provide high quality printing even on transfer paper with low surface smoothness. (Prior art) When printing prints from a computer or word processor using a thermal transfer method, a thermal transfer sheet with a heat-melting ink layer on one side of a base film and a thermal head are used. Conventional thermal transfer sheets , using paper such as capacitor paper or paraffin paper with a thickness of 10 to 20 μm, or a plastic film such as polyester or cellophane with a thickness of 3 to 20 μm as a base film, and a hot-melt ink that is a mixture of wax and pigment. It is manufactured by applying layers by coating.Although the thermal transfer method can print on plain paper,
Clear printing can be done on all types of plain paper.In case of trouble, high-quality paper or coated paper that has been calendered and has a value of 100 seconds or more will produce the best printing, and high-quality paper with a time of 50 seconds or more will suffice. You can obtain high printing quality. But 5
If a transfer paper with a low smoothness that does not reach 0 seconds is used, the sharpness of the print will deteriorate. This is because when paper has a highly uneven surface, the pressing pressure of the thermal head does not allow the ink surface to come into complete contact with the paper, and areas where there is no contact result in poor transfer. Problems to be Solved by the Invention The purpose of the present invention is to improve the drawbacks of the conventional thermal transfer method and transfer sheet described above, and to provide high quality printing even on transfer paper with low surface smoothness. An object of the present invention is to provide a thermal transfer method and a transfer sheet. Composition of the invention

[Means to solve the problem]

The heat-sensitive transfer sheet of the present invention is characterized by having a filler layer on the heat-melting ink layer provided on one side of the base film. The heat-sensitive transfer method of the present invention uses a heat-sensitive transfer sheet that has a layer of sealant on a heat-melting ink layer provided on a base film, and at the same time as transfer, seals only the printed portion of the transfer paper. It is characterized by carrying out the following. [Function l] The filler layer on the hot-melt ink layer is heated by the thermal head and transferred onto the transfer paper, filling in the unevenness of the surface and improving smoothness. Even when using low-quality transfer paper, it is possible to achieve high-quality printing similar to that achieved when transferring to paper that has been smoothed by sealing beforehand. [Embodiment] As the base film, commonly used plastic films such as polyester, polypropylene, cellophane, acetate, and polycarbonate, and papers such as condenser paper and paraffin paper are used. Polyester film is best. The heat-melting ink is prepared by blending carbon black, EVA1 paraffin wax, carnauba wax, and the like. The appropriate amount of heat-melting ink to be applied is a thickness of 3 to 8 microns in order to stably perform high quality printing. When a plastic film is used as the base film, it is preferable to provide a layer on the other side, that is, on the side opposite to the ink surface that contacts the thermal head, to prevent sticking to the thermal head. The anti-sticking layer basically includes a heat-resistant resin and a substance that functions as a heat release agent or a lubricant.
Heat-resistant resins include synthetic resins with a glass transition point of 60°C or higher, or thermoplastic resins with OH or C0OH groups, mixed with a compound having two or more 7-mino groups, or diisocyanate or triisocyanate. Those that have undergone crosslinking and curing are preferred. Thermal mold release agents or lubricants include those that melt when heated, such as waxes and amides, esters, and salts of higher fatty acids, and those that are useful while remaining solid, such as fluororesin and inorganic substance powders. There is something. As understood from the above, the filler has a melting point of 40 to 40, so that it melts when heated by the thermal head and functions as a seal for the transfer paper.
Select from waxes with a temperature range of 150°C. One typical filler is one whose main ingredient is an emulsion type wax, and carnauba wax, microcrystalline wax, paratmelt type fillers, and hot lacquer type fillers containing solvents can also be used. It is recommended to add an appropriate amount of extender pigment to the eye blocker. This is popular because it prevents printing from bleeding or trailing. The particle size of the extender pigment is not suitable if it is too large, and it is desirable that the average particle size is 5 μm or less. Suitable as extender pigments are inorganic fillers such as silica, talc, calcium carbonate, precipitated barium sulphate, alumina, titanium black or tin oxide. If the blending amount is less than 5% by weight of the filler composition, the effect will be poor, while if it exceeds 30%, the dispersibility will decrease and it will be difficult to adjust the ink. Because it may fall off (or become),
It is preferable to add it in a range of 5 to 30% by weight. When the thickness of the filler layer is less than 1 μm, the sealing effect is insufficient, and when it exceeds 4 μm, the printing tends to bleed. Two layers of hot melt ink are applied on the base film.
~4μ, the sealant layer preferably has a thickness of 1 to 4μ, and the total thickness is approximately 3 to 8μ. Thermal transfer generally produces glossy and beautiful prints, but on the other hand,
Matte printing may be desirable as it may make the document difficult to read. Several technologies have been developed to meet such demands, including those that use a heat-sensitive transfer sheet with a matte layer on the base film and coated with heat-melting ink, and those that use a matte layer on the base film itself. Japanese Patent Application Nos. 58-208306 and 2008 proposed by the applicant using a heat-sensitive transfer sheet made of
No. 8307 is an example of these) can also be applied in implementing the present invention. (Example 1) A thermofusible ink and a filler were prepared by blending the following raw materials (all parts are by weight). (Thermofusible ink) Carbon black "Diablack G" ( Mitsubishi Kasei)
15 parts ethylene/vinyl acetate copolymer r E V A Flex 310J (Mitsui Polychemicals) 8 parts paraffin wax [paraffin 150°FJ (Nippon Seiro) 47 parts carnauba wax 30 parts (filler) Natural wax emulsion [Die Jet T-10J
(Melting point 80℃, water 30%, compatibility chemistry)
57 parts paraffin wax emulsion "Dijet EKJ (melting point 55°C, water 30%, compatible chemical) 43 parts On a polyester base film, apply the above heat-melt ink to a thickness of 3 μm and filler to a thickness of 2 μm. The ribbon was coated to produce a thermal transfer ribbon. This ribbon was used in a commercially available thermal transfer printer, and the transfer properties were examined using plain paper with various smoothness as the transfer paper. The transfer properties were determined by the ink. The degree of inkling was measured using a halftone dot analyzer "Erea Duck 1500J (Konishiroku Photo Industry) and expressed as area dot%. If the area dot% is 80 or more, it can be said that the print is of sufficiently high quality for visual perception. The results are shown in the table below.For comparison, no filler layer was applied and hot melt ink 5.
The results obtained when using a transfer ribbon having only a μ layer are also shown. Transfer paper smoothness 4.6 seconds 10.1 seconds 33.1 seconds 52.1 seconds Example 1 80.6% 82.3% 86.1% 92.1
% comparative example 47.9 54.1 66.6
81.6 In the case of a comparative example corresponding to a conventional thermal transfer ribbon, good printing can be achieved with high-quality paper with a smoothness of 50 seconds or more, but with paper with a low smoothness, the print quality deteriorates. On the other hand, in the embodiment of the present invention using a transfer sheet having a layer of filler, high-quality printing can be performed even on paper with considerably low smoothness. [Example 21] The same procedure was carried out except that the following formulation was used, in which an extender pigment was added to the filler of Example 1. (mouth sealant) [Dijet Knee 10] (above > 50 parts [
Dijet EKJ (above) 20 parts Paraffin wax-silica [Bond Wax WE-3J (30% water, Bond Wax Co. > 30 parts Quality has been improved. Transfer paper smoothness [Example 3] In Example 1, Prior to coating the base film with the hot melt ink, the following composition (parts by weight) is prepared:
Prepare pine 1~ layer ink, polyester resin "Vylin 200" (Toyobo) 6 parts vinyl chloride/vinyl acetate copolymer resin [Vinyrite VAGHJ (IJCC) 7 parts silica [Erogil 0K412J 3 parts talc]
Micro Ace L-11J Nippon Talc> 1 part methyl ethyl ketone 30 parts toluene
30 parts of this was mixed with a 50% butyl acetate solution of the isocyanate "Takenate D-204J (Shikinichi Yakuhin Kogyo) in a ratio of mud ink composition: isocyanate solution = 20:3 (weight ratio), and then applied on the base film. The amount was 1 g/m.Hereafter, a thermal transfer ribbon was made in the same manner as in Example 1,
When we examined the transfer properties, they showed similar performance, with matte reading and rough printing. Effects of the Invention By using the @thermal transfer sheet of the present invention, high-quality printing can be performed even on transfer paper with low surface smoothness, so thermal transfer can be carried out on a variety of paper types. Patent Applicant Dainippon Printing Co., Ltd. Agent Patent Attorney Souo Suga Procedure? ...IF writing spontaneously) September 19, 1980 1, Display of the case 1989 Patent Application No. 172998 2, Name of the invention Thermal transfer sheet and transfer method 3, Person making the amendment Relationship with the case Patent applicant residence Address: 12, Ichigaya Kaga-cho, Shinjuku-ku, Tokyo
Name (289) Inu Nippon Printing Co., Ltd. Representative Kita
Yoshitoshi Shima (and 1 other person) 4, Agent 104 Address Yasuda Fudosan Tsukiji Building, 2-15-14 Tsukiji, Chuo-ku, Tokyo! (541) Column 7 of the title of the invention and the unexplored explanation in the 3792 specification, contents of the amendment
(1) The title of the invention, ``Thermal transfer method and transfer sheet'' on page 1, line 3 of the specification is corrected to ``Thermal transfer sheet and transfer method''. <2) "Thermal transfer method and transfer sheet" on page 4, lines 14 to 15 was changed to "thermal transfer sheet and transfer method"
I am corrected. (3) “EV A” on page 9, line 11 is corrected to “Eva”. (4) “30% water” on page 9, line 18 is changed to “30% water”.
Correct it as 5olidJ. (5) Add 30% water to [30%] on page 10, line 3.
Correct it as 5olidJ. (6) “Paraffin wax” on page 11, line 17.
Correct "silica" to "silanized silica emulsion". (7) On page 11, line 19, “30% water” was changed to “10% water”.
Correct it as 5olidJ. (8) Correct “Baylin” in line 10 of page 12 to “Byron”. (Kuh) “Erojiru OK” on page 12, line 14 of the same page. (10) “Micro Ace” on page 12, line 15 of the same page]
-11” is corrected as [Micro Ace L-11. Procedure? City official letter (spontaneous) Day 1, Incident indication 1982 Patent Application No. 172998 2, Title of invention Thermal transfer sheet and transfer method 3, Amendment Relationship with the case of a person covering the patent applicant Address 1-12 Ichigaya Kaga-cho, Shinjuku-ku, Tokyo Name
(289> Dai Nippon Printing Co., Ltd. Representative Yoshitoshi Kitajima (and 1 other person) 4, Agent 104 Address 2-15-14 Tsukiji, Chuo-ku, Tokyo (1)
It is also applicable even if the paragraph on page 9, line 4 of the specification is correct. ” and “[Example 11”] in the fifth line, add the following sentence. [Note that during printing, with a normal thermal transfer sheet, background stains on the transfer paper tend to occur due to rubbing between the transfer sheet and the transfer paper, but the thermal transfer sheet of the present invention having a layer of sealant, Even if it is rubbed, the surface layer of the filler layer only sticks to the transfer paper, which has the advantage of not causing stains. (2) Page 13, line 13 ``...Thermal transfer can be performed. Add the following sentence after ``.

Claims (8)

[Claims] (1) A heat-sensitive transfer sheet characterized by having a layer of sealant for transfer paper on a heat-melting ink layer provided on one side of a base film. (2) Claim 1 in which the filler is wax
Thermal transfer sheet. (3) The heat-sensitive transfer sheet according to claim 2, wherein the filler comprises a wax and an extender pigment. (4) Claim 3 uses a filler in which an inorganic filler with an average particle size of 5 μm or less is selected as an extender pigment and is blended so as to account for 5 to 30% by weight in the filler composition. thermal transfer sheet. (5) As extender pigments, silica, talc, calcium carbonate, precipitated barium sulfate, alumina, titanium white,
The heat-sensitive transfer sheet according to claim 4, using a material selected from clay, magnesium carbonate, carbon black, or tin oxide. (6) The thermal transfer sheet according to claim 1, wherein a plastic film is used as the base film and an anti-sticking layer is provided on the surface in contact with the thermal head. (7) The heat-sensitive transfer sheet according to claim 1, wherein a matte layer is provided on the base film, or the surface of the base film is matted, and the heat-melt ink layer and sealing layer are further provided. (8) A heat-sensitive transfer sheet having a layer of sealant on the heat-melting ink layer provided on the base film is used, and at the same time as the transfer, sealing treatment is performed only on the printed portion of the transfer paper. Thermal transfer method.