JPS63254094A - Thermal transfer material - Google Patents

Abstract

PURPOSE:To form a transfer recording image having durability, by respectively providing a first, second and third heat-meltable layers to a support in this order and containing an epoxy resin in the first layer or/and the third layer and containing the curing agent of the epoxy resin in at least one of the other layers. CONSTITUTION:The first, second and third heat-meltable layers 13, 14, 15 are respectively provided to a support 12. It is necessary to make the first layer easy to release from the support at the time of heating and the flocculation force thereof is made low so as to transfer the whole of the heated area of the first layer to a recording medium. The melt viscosity of the second layer is desirably made relatively low in order to melt the first and third layers in a mixed state. Since irregularity is generated in the density of a recording image and no sharp printing is obtained when the third layer is excessively penetrated in the recording medium, the flocculation force and melt viscosity of the third layer are pref. made high. Pref., a curing agent is contained in the first ink layer and an epoxy resin is contained in the third ink layer and both the epoxy resin and the curing agent are not contained in the second ink layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a thermal transfer material used in a thermal transfer recording method.

[Conventional technology]

In recent years, with the rapid development of the information industry, various information processing systems have been developed, and recording methods and devices suitable for each information processing system have also been developed and adopted. For one thing, the thermal recording method uses lightweight equipment and is noiseless.
It has excellent operability and maintainability, and has been widely used recently.

However, among the recording papers used in the thermal recording method, ordinary thermal recording paper is a color-forming processed paper containing a color former and a color developer, so it is expensive, and recording can be tampered with.1. The paper has disadvantages in that it is easily colored by heat or organic solvents, and the recorded image fades in a relatively short period of time, resulting in poor recording stability.

A thermal transfer recording method has recently been attracting particular attention as a method that maintains the advantages of the above-mentioned thermal recording method and compensates for the drawbacks associated with the use of thermal recording paper.

This thermal transfer recording method generally involves the following steps as shown in FIG.
A heat-sensitive transfer material 23 is used, in which a heat-transferable ink layer 22 formed by dispersing a coloring material in a heat-melting material is melt-coated on a sheet-like support 21. The ink layer 22 is superimposed on the recording medium so as to be close to the recording medium, and heat is applied from the support side of the thermal transfer material by a thermal head to transfer the melted ink layer onto the recording medium, thereby applying heat onto the recording medium. This is to form a transfer record 0@ according to the supply shape. According to this method, it is possible to maintain the above-mentioned aspects of the thermal recording method and to use plain paper as a recording medium, and also to eliminate the drawbacks associated with the use of thermal recording paper described above.

However, conventional thermal transfer recording methods are not without drawbacks.

One of them is that the thermal transfer ink layer of conventional thermal transfer materials is
As mentioned earlier, since the colorant is dispersed in the heat-melting material, this heat-melting material has reversible heat-melting properties and is relatively brittle, so it cannot be used after heat transfer. The recorded image also tends to be brittle, and may soften or remelt at high temperatures. Therefore, if the surface of the recording section is rubbed, it is likely to become smudged or peeled off, and if the recording medium is stored at high temperatures, the recorded image may bleed, and if it is stacked one on top of another, Phenomena such as set-off occur.

For this reason, a heat-sensitive transfer material has been proposed in which the heat-melt ink layer contains a compound that causes reactive cross-linking to improve durability, so that the durability of the ink layer is increased through reactive cross-linking over time after transfer. However, in this case, there is a problem in that reactive crosslinking occurs even before recording, deteriorating the storage stability of the heat-sensitive transfer material and inhibiting the transferability of the ink.

Furthermore, in recording using conventional thermal transfer materials, penetration of ink into the recording medium is essentially unavoidable, and it is impossible to correct erroneously recorded areas by peeling them off.

For this reason, there is a need for a type of thermal transfer material that allows the transferred recorded image to be corrected, and in which areas that do not require correction cannot be tampered with afterwards.

In addition, in the conventional thermal transfer recording method, the transfer recording performance, that is, the print quality, is greatly affected by the surface smoothness of the recording medium. In the case of recording media, the print quality deteriorates significantly.

However, even when using paper, which is the most typical recording medium, highly smooth paper is rather special, and ordinary paper has various degrees of unevenness due to entangled fibers. Therefore, in the case of paper with large surface irregularities, the hot melted ink cannot be transferred to the entire recording area of the paper during printing, but only penetrates and adheres to the convexities on the surface or the vicinity thereof, resulting in the edges of the printed image being uneven. If this happens, part of the image may be missing, resulting in a decrease in print quality.

[Problems to be solved by the invention]

The present invention has been made to solve the above-mentioned conventional problems.

Accordingly, a first object of the present invention is to provide a heat-sensitive transfer material that can form a transferred recorded image that is thermally and mechanically durable and has good storage stability before recording.

A second object of the present invention is to provide a heat-sensitive transfer material that can correct erroneously recorded areas and provide a transferred recorded image that does not require correction or that can prevent falsification of normal recorded areas after correction. There is a thing called K.

A third object of the present invention is to provide a thermal transfer material that makes it possible to form a good transferred recorded image even on a recording medium with poor surface smoothness.

[Problems to be solved by the invention]

The heat-sensitive transfer material provided by the present invention includes, on a support,
From the support side, the first layer, the M2 layer, and the third layer are respectively heat-fusible, and the first layer and/or the third layer contain an epoxy resin, and the epoxy resin It is characterized in that at least the other layer (1) which does not contain resin contains an epoxy resin curing agent.

When thermal transfer recording is performed using the thermal transfer material of the present invention,
Due to the heat obtained during recording and the melting and mixing effect between the layers, the separately contained epoxy resin and the curing agent for the polyurethane resin mix, and a curing reaction begins. Therefore, the curing reaction does not occur before recording and the storage stability is good, and the curing reaction progresses due to changes over time after recording or secondary treatments such as heating and pressurization performed after recording. The film strength and cohesive force of the image are increased, and since the epoxy resin increases the adhesive force with the paper and the recording medium, the durability of the recorded image is improved.

In addition, immediately after recording, before the secondary processing, and before the hardening of the epoxy resin has sufficiently progressed, the recorded image does not penetrate excessively into the recording medium, and since it has film properties, it is possible to erase erroneously recorded areas. Corrections such as re-recording are possible, and it is difficult to peel off the recorded image after the epoxy resin has hardened, thus preventing falsification.

Moreover, since it is divided into three layers: the first layer, the second layer, and the third layer, which are heat-meltable, it is easier to adjust the physical properties such as melt viscosity and cohesive force of each layer, and it is possible to avoid problems with poor surface smoothness. It is also possible to provide good recording on a recording medium.

Hereinafter, the present invention will be described in further detail with reference to the drawings as necessary. In the following description, "chi" and "part" representing quantitative ratios are based on weight unless otherwise specified.

FIG. 1 is a schematic cross-sectional view in the thickness direction for explaining the structure of the thermal transfer material of the present invention.

As illustrated in FIG. 1, the thermal transfer material 11 of the present invention usually has a heat-fusible first layer 13, a second layer 14, and a third layer 15 on a sheet-like support 12. have.

As the support 12, conventionally known films and papers can be used as they are, such as films of relatively heat-resistant plastics such as polyester, polycarnate, triacetylcellulose, nylon, and polyimide, cellophane, or sulfuric acid. Paper or the like can be suitably used.

The thickness of the support is preferably about 2 to 15 microns when considering a thermal head as a heat source during thermal transfer, but for example, a heat source such as a laser beam that can selectively heat the thermal transferable ink layer is used. In this case, the heat resistance of the support can be improved by providing a heat-resistant protective layer made of epoxy resin, phenol resin, melamine resin, nitrocellulose, etc., or it is possible to use a support material that could not be used conventionally. You can also do it.

The first layer, the second layer, and the third layer can be made to exhibit heat-melting properties by using essential components such as the epoxy resin, but they can be made to have heat-melting properties by containing other appropriate heat-melting materials. This is desirable because it is possible to easily exhibit desired physical properties such as the above-mentioned melt viscosity and cohesive force to a desired degree.

In this case, the heat-melting materials used for the first ink layer, second layer, and third layer are desirably selected in consideration of physical properties such as cohesive force and melt viscosity of each layer as described above. As an example, by adopting the following selection criteria, it is possible to obtain a thermal transfer material that is excellent in recording transferability, print quality, etc., and further improves transferability on recording media with poor surface smoothness. can.

That is, the first layer needs to be easily peeled off from the support when heated. For this purpose, the interfacial shear force at the interface between the heated region and the unheated region is small, and the cohesive force of the first layer is small so that the entire first layer in the heated region is transferred to the recording medium. It is necessary.

In the transfer material before recording, the second layer is the first layer and the third layer.
When the layers are completely isolated and melted by heating or secondary processing during recording, it is desirable that the melt viscosity is relatively low so that the first layer and the third layer can be mixed and fused. The third layer is peeled off when the first layer is peeled off from the support, so the cohesive force may be large. Rather, the layer of the cylinder 3 may excessively permeate into the recording medium after being transferred to the recording medium. In this case, the density of the recorded image becomes paranky, making it impossible to obtain a clear print and making it impossible to correct erroneous recording. Therefore, it is preferable that the third layer has a large cohesive force and a high melt viscosity. be.

The preferred physical properties of the first layer, second layer, and third layer vary depending on conditions such as the amount of heat during thermal printing and the pressure applied to the thermal transfer material and recording medium, but generally the physical properties are as follows. It is desirable that the conditions are met.

That is, for the reasons mentioned above, the cohesive force of the first layer is usually 2-100 kg/m'' at 20°C, the cohesive force of the second layer is 2-300 kg/m'', and the cohesive force of the third layer is 3.
A range of 0 to 300 kJi/cm" is preferable. Also,
Outflow start temperature (Shimadzu Flow Tester CFT-5
00A type, load 30kli+, temperature increase rate 2℃/m i
It refers to the temperature that gives an apparent viscosity of 5 x 10 pg under the conditions of n. ) is preferably in the range of 40°C to 120°C for the first layer, 40°C to 120°C for the second layer, and 50°C to 150°C for the third layer. The melt viscosity (at 150°C) measured by a rotational viscometer is 10 to 10,000 for the first layer.
Centiboise, 2o to 6000 centiboise, 2nd
The layer is between 1 and 10,000 centipoise, especially between 2 and 6,000 centipoise.
Centiboise is preferred.

As mentioned earlier, the function of the third J- is that it does not penetrate deep into the paper, but uses small contact points with the paper as a foothold to form a film on the entire dot or in the connections between dots. It is preferable to transfer onto uneven paper in the form of a cover, and in this respect, the melt viscosity is 500°C at 150°C.
Centipoise ~ 2,000,000 centipoise, especially 2
000: centipoise-1,000,000 centipoise is suitable. If the melt viscosity is too low, the recording material (paper)
The ink permeates from the place where it comes into contact with the convex part, and the ink is not likely to be cut off at that part, and if it is too large, the adhesion to the recording member will deteriorate.

When selecting based on these criteria, suitable heat-melting materials used for the first layer include natural waxes such as spermaceti wax, beeswax, lanolin, carnauba wax, candelilla wax, and montan wax, paraffin wax, and micro- Synthetic waxes such as crystalline wax, oxidized wax, ester wax, and low-molecular FZ polyethylene; higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, fromene acid, and behenic acid;
Stearyl alcohol, behenyl alcohol, etc.? a
xR alcohol, esters such as fatty acid ester of citrus sugar, fatty acid ester of nlupitan, amides such as stearinamide and oleinamide, etc. are used as main components, and within the range that satisfies the conditions of cohesive force and melt viscosity, polyolefin resin, polyamide resin, polyester resin, epoxy resin, polyurethane resin,
Elastomers such as acrylic resins, vinyl chloride resins, cellulose resins, polyvinyl alcohol resins, petroleum resins, phenolic resins, styrene resins, natural rubber, styrene-butanoene rubber, Inglene rubber, chloroglene rubber, etc. Alternatively, an appropriate mixture of oils such as mineral oil and vegetable oil may be used.

The suitable heat-melting material used for the second layer is selected as appropriate from among the hot bath-melting materials exemplified in the case of the first layer, taking into consideration physical properties such as cohesive force and melt viscosity. can do.

In addition, suitable heat-melting materials used for the third layer include polyamide resins, polyolefin resins, polyester resins, epoxy resins, polyurethane resins,
Mainly elastomers such as acrylic resins, vinyl chloride resins, cellulose resins, polyvinyl alcohol resins, petroleum resins, phenolic resins, styrene resins, natural rubber, styrene-butadiene rubber, imprene rubber, and chloroglene rubber. A heat-melting material used as a main component of the first layer or a plasticizer such as tricresol phosphate or dibutyl phthalate, or mineral oil or vegetable oil, if necessary, within a range that does not deviate from the above viscosity and cohesive force. You may mix and use them as appropriate.

In addition, the said cohesive force means what was measured under the following conditions.

Measuring equipment: Tensilon RTM-100 (manufactured by Toyo Goldwin) Measuring sample: Width 10 gourds x thickness 0.1-2 wm (Tension part) Knob spacing: 20 m1 Tensile speed y 100 w/min Measurement temperature/humidity: 20°C 65% RH Epoxy resins used in the present invention include bisphenol A, bisphenol F, halogenated bisphenol,
One type or two or more types of epoxy resins derived from the condensation reaction of tetrahydroxyphenylethane, novolac, etc. and epichlorohydrin may be used in combination as appropriate. When the epoxy resin is used in combination with other heat-fusible materials, it is usually preferably used in an amount of 1 to 50 parts per 100 parts of the heat-fusible material.

If it is less than 1 part, the desired effect cannot be obtained, and if it exceeds 50 parts, the cohesive force of the layer containing the epoxy resin will decrease, which is not preferable.

Further, the curing agent for the epoxy resin is appropriately selected depending on the type of the epoxy resin. Suitable ones include organic amines and acid anhydrides. Examples of organic amines include primary amines and secondary amines having active hydrogen, or complex compounds derived from Lewis acids such as aluminum chloride, aluminum bromide, titanium tetrachloride, and the aforementioned primary amines or secondary amines. used. Further, as the acid anhydride, anhydrides of dicarboxylic acids such as phthalic anhydride are used.

As mentioned above, the epoxy resin is used in the 10th layer and/or the 3rd layer.
The epoxy resin curing agent is contained in at least one of the layers that do not contain an epoxy resin.

Further, the layer to which the epoxy resin and curing agent are added may be either the first ink layer or the third ink layer, and since both do not coexist, they may be added to either of the ink layers.

However, for the purpose of improving the fixability of printing, a combination in which the first ink layer preferably contains a curing agent and the third ink layer contains an epoxy resin is preferred. Furthermore, since the second ink layer is an ink layer intended to separate and protect the epoxy resin-containing layer and the curing agent-containing layer, it does not contain either an epoxy resin or a curing agent.

At least one of the first layer, second layer, and third layer contains a coloring material for coloring, if necessary. Colorants include carbon black, nigrosine dye, lamp black, Sudan black SM, alkali blue, First Niro 01 benzidine yellow, pigment yellow, India first orange, irgazine red, Nogura nitroaniline red, Toluidine Red, Carmine FB, Permanent Bordeaux FRB, Pigment Orange R%J Sole and Red 20, Lake Red C10-Damine FB.

Rhodamine B Lake, Methyl Violet B-ki, Phthalocyanine Blue, Pigment Blue, Brilliant Green B1 Phthalocyanine Green, Oil Yellow GG, Zapon First Niro-CGG, Kayaset Y963, Kayaset YG, Sumiplast Niro G , Zapon First Orange RR, Oil Scarlet, Sumiplast Orange G1 Orazole Brown B1 Zapon First Nucaret CG, Eisensviron Red, BEH, Oil Pink OP1 Victoria Blue F4R, First Gumpuru-5007,
Printing, such as Sudan blue, oil peacock blue, etc.
All the various dyes and pigments used in the field of recording can be conveniently used. These layer coloring agents can usually be used in a proportion of 3 to 450 parts per 100 parts of the heat-melting material.

In the present invention, it is possible to erase and correct the recorded image before the curing reaction of the epoxy resin has sufficiently progressed, but specific methods for erasing the recorded image include peeling with an eraser or adhesive tape. It will be done.

In addition, the curing reaction of epoxy resin is started by mixing it with an organic amine or acid anhydride due to the heat during recording and the melt mixing effect, but if the curing reaction does not proceed sufficiently, heating or The recorded image may be further hardened by performing a secondary treatment that accelerates the reaction using a pressure roll, open heating light irradiation, or the like.

To obtain the thermal transfer material of the present invention, first, various additives such as the heat-melting material, colorant, and dispersant and filler that can be used in the first layer are melt-kneaded using a dispersion device such as an attritor. Alternatively, the ink is kneaded with a suitable solvent to obtain a hot-melt ink or a solution or dispersion ink, and this ink is applied onto a support to form the first layer. Next, the second layer is formed by the same method as the first layer as described above.
It is sufficient to form a third layer.

The thickness of the first layer, second layer, and third layer obtained as described above is 1 to 10 μm%, 0.1 to 5 μm, respectively.
The thickness is preferably in the range of 1 to 10 μm, and the thickness of the entire ink layer is preferably in the range of 3 to 20 μm.

The planar shape of the thermal transfer material of the present invention is not particularly limited, but it is generally used in the form of a tie-brighter bin or a wide tape used in line printers. Further, for color recording, it is also possible to use a thermal transfer material in which heat-melting inks of several tones are applied in stripes or blocks.

Further, the thermal transfer recording method using the thermal transfer material of the present invention includes:
This method is not particularly different from the conventional method, and recording media made of plain paper or the like are stacked so as to be in contact with the heat transferable ink layer of this heat-sensitive transfer material, and the recording medium is preferably heated from the support side of the heat-sensitive transfer material using a thermal head or laser beam. After applying heat in a pattern according to a desired recording pattern, the heat-sensitive transfer material and the recording medium may be dispersed.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Carmen black 10 parts Polyethylene wax (softening point 95°C) 6 parts M ethylene-vinyl acetate copolymer (softening point 68°C) 30 parts Carbon black obtained by heating and dispersing with the above-mentioned generating attritor While heating the dispersion to about 100°C, a toluene/xylene mixed solvent (mixing ratio 50150
) 400 parts were added, stirred vigorously, and then cooled to room temperature to obtain a fine dispersion of ink.

Next, 100 parts of the above dispersion and 2 parts of diethylenetriamine were added and mixed to obtain a first layer-forming coating solution.

Dry the above-mentioned first layer-forming coating liquid and prepare a sample.
When the melt viscosity and cohesive force were measured at 50°C, the following values were obtained.

Melt viscosity at 150°C 5000 centidays Cohesive force (20°C) 3 Yu/crn2 Then 50 parts of carnauba wax (softening point 70°C) 50 parts paraffin wax (softening point 80°C) A second layer-forming composition was obtained by thermal dispersion.

A sample was prepared using the second layer-forming composition, and
When we measured the melt viscosity and cohesive force at °C, we found that
I got the following values.

150C melt viscosity 30 centipoise cohesive force (2
0°C) 2.5 kg/cm2 Next, 60 parts of vinyl acetate-ethylene copolymer, 30 parts of low molecular weight polyethylene oxide, and 10 m of mother rough-in wax (softening point: 80°C) were heated and dispersed in the above-mentioned Seikokin Attritor. This is about 100℃
While heating, 400 parts of a toluene/xylene mixed solvent (mixing ratio 50150) was added, stirred vigorously, and then cooled to room temperature to obtain a fine dispersion of ink. Next, the above dispersion 100
5 parts of bisphenol A type epoxy resin was added to obtain a coating solution for forming a third layer.

The third layer-forming coating solution was dried and a sample was prepared, and the melt viscosity and cohesive force at 150° C. were measured, and the following values were obtained.

Melt viscosity at 150℃ 55000 centipoise Cohesive force 20℃ 60 kg7cm2 then 6μ
A first layer having an average thickness of 3 μm was obtained by applying the first layer-forming coating liquid onto the polyethylene terephthalate film of 100 m using an applicator and drying it.

Next, a coating liquid for forming a second layer was hot-melt coated onto the first layer using a wire bar to obtain a second layer having an average thickness of 2 μm. Next, a third layer forming coating liquid is applied onto the second layer using an applicator and dried to form a third layer having an average thickness of 3 μm, thereby forming the thermal transfer material of the present invention. I got it.

When this thermal transfer material was printed on a bond paper with a Peck smoothness of 12 seconds using Canoward 458, the print was very clear and had good print density and quality. Furthermore, when the printed characters were rubbed with an eraser immediately after printing, they could be erased. Furthermore, after printing - after leaving the prints at room temperature day and night, attempts were made to erase them with an eraser comb in the same manner, but it was not possible to erase them, confirming that the prints had excellent fixation properties.

Comparative Example 1 Carden Black 10 parts Carnauba wax 50 parts Paraffin wax
40 parts of the above-mentioned attritor was heated and dispersed to obtain an ink layer-forming composition.

Melt viscosity at 150°C of the above ink layer composition and 2
When the cohesive force was measured at 0°C, the following values were obtained.

Melt viscosity at 150°C 40 centipoise Cohesive force (20°C) 2.7 Yu/Tan 2 A thermal transfer material was obtained in the same manner as in Example 1, and a printing test was conducted on the thermal transfer material in the same manner as in Example 1. However, the printing was unclear on Punto paper with Peck smoothness, and satisfactory printing quality could not be obtained. Furthermore, when the print was rubbed with an eraser immediately after printing, it was impossible to erase it.

〔Effect of the invention〕

According to the thermal transfer material of the present invention, a thermally and mechanically durable transferred recorded image can be formed, and furthermore, the thermal transfer material has good storage stability before recording. Moreover,
In the transferred recorded image that is formed, it is possible to correct the erroneously recorded portion, and either no correction is required, or it is possible to prevent falsification of the correct recorded portion after the correction. Further, a good transferred recorded image can be formed even on a recording medium with poor surface smoothness.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view in the thickness direction for explaining the structure of a thermal transfer material of the present invention, and FIG. 2 is a conventional thermal transfer material. 11.23 Thermal transfer material, 12.21 Support, 13 First layer, 14 Second layer, 15...
- Third layer, 22... thermal transferable ink layer.

Claims (1)

[Claims] On the support, from the support side, heat-fusible first
, a second layer, and a third layer, the first layer and/or the third layer contains an epoxy resin, and at least one other layer that does not contain the epoxy resin contains an epoxy resin. A heat-sensitive transfer material characterized by containing a curing agent.