JPH03124493A - Sublimation type thermal transfer body - Google Patents

Abstract

PURPOSE:To prevent fusion in speed-difference recording, defective travelling and the thermal transfer of an ink layer by specifying a dynamic friction coefficient to an image-receiving sheet of a sublimation type thermal transfer body in a recording method in which the image-receiving sheet and a recording medium are made to travel under specific conditions. CONSTITUTION:A sublimation type thermal transfer body and an image-receiving sheet are superposed, and both the thermal transfer body and the sheet are made to travel under the conditions of [speed of image-receiving sheet]/[speed of a recording medium]>1 or [feed rate of the image-receiving sheet]/[feed rate of recording medium]>1 and thermal printing is conducted. A dynamic friction coefficient to the image-receiving sheet of the sublimation type thermal transfer body is brought to 0.20 or less at 80 deg.C on measurement according to ASTMD1894 at that time. A dye sublimating and vaporizing at 60 deg.C or higher is used as a sublimating dye, and a vinyl chloride resin, a vinyl acetate resin, etc., are cited as a bonding agent. Condenser paper and a polyester film are employed as a base body sheet, and the kind of the bonding agent, the content of the sublimating dye, etc., are quoted as factors adjusting the dynamic friction coefficient.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a sublimation type thermal transfer material.

[Prior Art] In recent years, the demand for full-color printers has increased year by year, and the recording methods for these full-color printers include electrophotography,
There are inkjet methods, thermal transfer methods, etc., but the thermal transfer method is often used because it is easy to maintain and is noiseless.

This thermal transfer method is a thermal transfer recording medium (so-called color ink sheet) in which an ink layer is provided on a substrate, in which a colorant is dispersed in a heat-fusible substance or a sublimable dye is dispersed in a resin binder. Lay the image receiving sheet on the ink layer surface of
This is a recording method in which thermal energy controlled by an electric signal from a laser or a thermal head is applied from the recording medium side, and the ink in that area is thermally melted transferred or sublimated onto the image receiving sheet to form an image.

This thermal transfer recording method is roughly divided into a heat-melting transfer type and a sublimation transfer type depending on the type of recording medium used, but the latter in particular has a principle in which dyes are transferred in response to heat energy from a thermal head, etc. Since it sublimates in a monomolecular form, it has the advantage of easily obtaining intermediate tones and being able to control the gradation at will, and is considered to be the most suitable method for full-color printers.

However, this sublimation thermal transfer recording method uses one each of yellow, magenta, cyan, and (black) ink sheets and performs selective thermal printing on each ink sheet to obtain one full-color image. After that, even if unused parts remain, they are discarded, which has the disadvantage of high running costs.

In order to overcome this drawback, in recent years a method has been used in which the same ink sheet is used repeatedly to perform printing and recording many times. Specifically, the constant speed mode method involves printing repeatedly while the ink sheet and image receiving sheet are running at a constant speed, and the method in which the speed of the image receiving sheet is n times the speed of the ink sheet (n>
There are two methods: 1) and the 0x mode method, in which printing is performed repeatedly with both sheets running. The latter 0x mode method is a method in which printing is performed multiple times using a relative speed method that gradually shifts the overlap between the previously used portion of the ink layer and the later used portion. Note that in the 0x mode method, it goes without saying that the larger the n value, the more advantageous it is in terms of cost.

In this multi-time recording method using the 0x mode method, a part of the unused portion of the ink layer is always supplied each time printing is performed, so the multiple recording method using the constant-velocity mode method, which simply uses the used portion repeatedly, is indispensable. Compared to the continuous recording method, it has the advantage of reducing the variation in residual ink due to recording history (IEICE Transactions Cvol J 70-C, N
o.

11, pp. 1537-1544, November 1987).

Furthermore, when recording is attempted multiple times using the 0x mode method, the ink layer and the surface of the image receptor may become more closely adhered or friction may occur.
There is a risk of poor running, and as a method for improving this problem, it is known to mix a substance having slipperiness or release properties into the ink layer.

However, even with the use of these generally good materials, the results were still insufficient in the 0x mode method.

[Problems to be Solved by the Invention] Under these circumstances, the present invention aims to provide a sublimation method that does not cause fusion between the ink layer and the image-receiving layer, poor running, or thermal transfer of the ink layer even in the n-times mode recording method. The object of the present invention is to provide a type thermal transfer body.

[Means for Solving the Problems] The present inventors have conducted intensive studies to solve the above-mentioned problems, and have found that it is effective to control the coefficient of dynamic friction of the sublimation type thermal transfer material with respect to the image receiving sheet within a specific range. We have discovered that this is the case, and have arrived at the present invention.

That is, the present invention provides (1) overlapping a sublimation type thermal transfer member and an image receiving sheet [speed of image receiving sheet]/[speed of recording medium]>
1 or [Image-receiving sheet feed amount] / [Recording medium feed amount]> While both are running under the conditions of 1, thermal printing is performed from the back side of the recording medium to transfer the dye in the transfer body in that area onto the image-receiving sheet. In the sublimation type thermal transfer body used in the recording method of transferring,
The coefficient of dynamic friction of the sublimation type thermal transfer body with respect to the image receiving sheet is A
A sublimation type thermal transfer material characterized by having a coefficient of 0.20 or less at 80°C when measured according to STM D 1894, and (2) a sublimation type thermal transfer material having a particulate sublimable dye on a substrate. The sublimation type thermal transfer material according to (1) above, which has an ink layer containing an organic binder or an ink layer formed by laminating a dye supply layer consisting of a sublimable dye and an organic binder in order from the substrate side. It is.

In the present invention, the dynamic friction coefficient is determined according to ASTM D1894 using a surface property tester TYPE: HEICON-14s/D.
[Manufactured by Shinra Kagaku Co., Ltd.] is used in conjunction with a heating device to superimpose RL and IL for measurement.

To explain the present invention specifically, the recording medium used is a sublimable dye that sublimes or vaporizes at 60°C or higher, and is mainly used in the field of thermal transfer recording such as disperse dyes and oil-soluble dyes. For example, C1
1, Disperse yellow 1.3.8.9.1B, 4
1.54.60, 77.116, etc., C, 1, Dispersed thread 1.4.6, 11, 15, 17, 55°5
9.60.73.83, etc., C, 1, Disperse Blue 3, 14.19.26.5B, 60, 84, 72,
99.1 mouth 8 etc., C, 1, solvent yellow 77
．． 118 etc., C, 1, Solvent Red 23.25
．． 27 etc., C, 1, Solvent Blue 36.83,
105 and the like. These dyes may be used alone or in combination.

Examples of binders that hold sublimable dyes include vinyl chloride resin, vinyl acetate resin, polyamide, polyethylene, polycarbonate, polystyrene, polypropylene, acrylic resin, phenol resin, polyester, polyurethane, epoxy resin, silicone resin, and fluorine resin. Examples include resin, butyral resin, melamine resin, natural rubber, synthetic rubber, polyvinyl alcohol, cellulose resin, and the like. These resins can be used alone, but several types may be mixed or a copolymer may be used. More preferably, the binder has a curing reaction product of isocyanate and a binder having an OH group, and the polymer compound for the binder having active hydrogen used in the urethane forming reaction is polyvinyl butyral. , polyvinyl acetal, polyurethane polyol, polyether polyol, polyester polyol, acrylic, acrylic-polyester copolymer, alkyd, silicone polyester, and those in which the epoxy group of epoxy is ring-opened with alkanolamine to form a 10H group. As the isocyanate, di- or tolylene diisocyanate is effective, such as 2.44-lylene diisocyanate, 2,6-1-lylene diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, triphenylmethane. Examples include triisocyanate, isophorone diisocyanate, bisisocyanate methylcyclohexane, and trimethylhexamethylene diisocyanate.

Among these, polyvinyl butyral is particularly desirable because it has a rate interaction with the dye used and can achieve both barrier properties against dye diffusion and ribbon storage stability.

In addition, as an isocyanate, commercially available Coronate L (
(manufactured by Nippon Polyurethane Co., Ltd.) and Takenate D (manufactured by Takeda Pharmaceutical Co., Ltd.) are preferable because they are easy to handle.

The mixing ratio of the two is preferably in the range of 0.1:1 to 1:1 between the -NGO group of the isocyanate and the 10H group of the active hydrogen-containing compound.

In addition, the dye concentration is 5 to 80% by weight, preferably 1
It is about 0 to 60% by weight.

The ink layer thickness is 0.1 to 30 μm, preferably 1.0 to 2
It is 0 μm.

It is also preferable to mix a substance with slipping or mold-releasing properties into the ink layer.
Examples of lubricating substances include Ishiura-based lubricating oils such as liquid paraffin, synthetic lubricating oils such as hydrogen halides, diester oils, silicone oils, and fluorosilicone oils, various modified silicone oils (epoxy-modified, amino-modified, alkyl silicone-based lubricating substances such as copolymers of organic compounds such as polyoxyalkylene glycol and silicone, various fluorine-based surfactants such as fluoroalkyl compounds, trifluorochloroethylene low polymers, etc. fluorine-based lubricating substances, waxes such as paraffin wax and polyethylene wax, higher fatty acids, higher fatty alcohols, higher fatty acid amides, higher fatty acid esters, higher fatty acid salts, and particles having the above-mentioned lubricity or thermal release properties. There are various types of particles mentioned above.

The content of the substance having slipperiness or mold release properties in the dye transfer contributing layer is preferably 5 to 30% by weight.

If the content is less than 5%, the mold releasability or adhesion prevention effect will be insufficient, while if it exceeds 30%, problems will occur in storage stability.

In addition, films such as capacitor paper, polyester film, polystyrene film, polysulfone film, polyimide film, and polyamide film are used as the base sheet, and a conventional adhesive layer or the like is used between the base sheet and the ink layer as necessary. Furthermore, a conventional heat-resistant lubricant layer may be provided on the back surface of the base sheet, if necessary.

Furthermore, as described in Japanese Patent Application No. 62-280434, which satisfies the above, the ink layer has two layers: a dye transfer contributing layer (a layer that contributes to image formation) and a dye supply layer (a layer that supplies dye to the contributing layer). Laminated type with separated functions and patent application 1986
-316979, a single-layer type in which particulate dye is dispersed, is suitable for the 0x mode method for multipurpose use.

In addition, the method for adjusting the coefficient of dynamic friction includes, specifically, the type of binder used, the content of sublimable dye, the degree of hardening of the binder, the type of substance with lubricity or mold release properties, and the addition of The most effective way is to control the amount of substances that have lubricity or mold release properties.As the amount increases, the coefficient of dynamic friction decreases. It is preferably about % by weight.

In addition, other auxiliary measures include the type of binder and curing of the binder. As for the type of binder, the coefficient of dynamic friction can be increased by using a resin that is incompatible with the resin used in the image-receiving layer. For example, when polyester resin is used as the image-receiving layer resin, acrylic resin, salt picopolymer xylene, chlorosulfone rubber, cellulose type, butyral, polyester polyol, fluorine type, oligomer, etc. can be used as the binder for the ink layer. Styrene-based incompatible resins are preferred.

Curing of the binder is also effective in improving the coefficient of dynamic friction due to softening and melting of the binder during heating recording, and the above-mentioned heat curing, ultraviolet curing, etc. are useful as curing methods.

The dynamic friction coefficient range is preferably 0.20 to 0.05, preferably 0.15 to 0.10, and the coefficient is 0.
．． If it is less than 05, there will be a side effect that wrinkles will easily occur on the transfer material.

The present invention will be explained in more detail with reference to Examples below.

Example 1 (Intermediate adhesive layer formulation) Part by weight Polyvinyl butyral BX-110 [Built-in Chemical Industry Co., Ltd. Koshiisocyanate Coronate L5 [Japan Polyurethane Industry Co., Ltd.] Toluene 95 Methyl ethyl ketone 95 (Ink layer formulation) Polyvinyl butyral BX-17 Sublimation Color dye Kaya Set Blue 14 167 Mino-modified silicone oil 5iP8417 2 Epoxy-modified silicone oil 5F8411 2 Diisocyanate
Coronate 2 Toluene 70 Methyl ethyl ketone 70 The composition of the above formulation
After dispersion in a ball mill for 4 hours, a 6 μm thick aromatic polyamide film with a 1 μm thick silicone resin heat-resistant layer formed on the back side was coated with a 1.0 μm thick intermediate adhesive layer using a wire bar, and then a dye was added on top of it using a wire bar. ．． ``0g7m'' Form a cyan ink layer.

Further, as an image-receiving paper, a mixture having the following composition was sufficiently mixed and dispersed to prepare a dye-receiving layer coating liquid [A].

[A] Liquid vinyl chloride/vinyl acetate/vinyl alcohol copolymer (VAGH; manufactured by Union Carbide Co., Ltd.) 10 parts Isocyanate (Coronate L; manufactured by Nippon Polyurethane Industries, Ltd.) 5 parts Amino-modified silicone (SF-8417; Toshi Silicone) company) 0.
5 parts Epoxy-modified silicone (SF-8411; manufactured by Toshi Silicone Co., Ltd.) 0.5 parts Toluene 40 parts Methyl ethyl ketone 40 parts Next, using a wire bar, apply liquid [A] to a synthetic paper with a thickness of about 150 μm (Yupo FPG- 150; manufactured by Oji Yuka Synthetic Paper Co., Ltd.) and dried for 1 minute at a drying temperature of 75°C to form a dye-receiving layer with a thickness of about 5 μm, and then stored at 80°C for 3 hours. This was cured to produce an image-receiving medium of the present invention.

ASTM 018
The dynamic friction coefficient measured at 80℃ according to 94 was 0.1.
It was 0.

Comparative Example 1 Comparative Example 1 was carried out in the same manner as in Example 1 except that the amino-modified silicone oil and epoxy-modified silicone in the ink layer formulation were omitted.

The dynamic friction coefficient at this time was 0.21.

Example 2 [Formulation of the first layer] Part by weight Polyvinyl butyral resin BX-17 Sublimation dye Kayaset Bruch 14 30 Polyethylene oxide 3 Coronatate 2 Toluene 5 Methyl ethyl ketone 5 [Formulation of the second layer] Polyvinyl butyral resin BX-110 Sublimation Sex dye Kaya set blue 14t.

Amino modified silicone oil S F 8411 1.5
Epoxy modified silicone oil 5P8417 1.5 Coronate L2 Toluene 95 Methyl ethyl ketone 95 The composition of the above formulation was placed on a film provided with an intermediate adhesive layer in the same manner as in Example 1 so that the first layer had a thickness of 4.5 μm and the second layer had a thickness of 1.0 μm. All other steps were the same as in Example 1.

The coefficient of dynamic friction at 80° C. at this time was 0.10.

Comparative Example 2 The same procedure as in Example 2 was carried out except that the amino-modified and epoxy-modified silicone oil in the second layer was omitted.

The coefficient of dynamic friction at 80° C. at this time was 0.22.

Example 3 Polyethylene wax 32 was used instead of amino-modified silicone oil and epoxy-modified silicone oil in Example 1.
0MP [Mitsui Petrochemical Industries, Ltd.] All procedures were carried out in the same manner except that 14 parts by weight was used.

The coefficient of dynamic friction at 80°C was 0.15.

Example 4 Rice wax No. 1 was used instead of amino-modified silicone oil and epoxy-modified silicone oil in Example 2.
(Noda wax) The same procedure was repeated except that 3 parts by weight was used.

The coefficient of dynamic friction at 80°C was 0.16.

The above Examples 1 to 4 and Comparative Examples 1.2 were recorded using a thermal head under the following conditions.

Impression type crab 442 mW/dot Thermal head: 6 dots/mm Partial gray Speed ratio between image receiving paper and recording medium n-7 Applied energy: 2.21 nj/dot As a result, in Examples 1 to 4, the distance between the ink layer and the image receiving layer In Comparative Example 1.2, running defects due to fusion and thermal transfer of the ink layer did not occur due to fusion, but in Comparative Example 1.2, running defects and thermal transfer of the ink layer due to fusion occurred between the ink layer and the image-receiving layer.

[Effects of the invention 1. In n-times mode recording, the dynamic friction coefficient μ of the ink layer against the image receiving layer is 8 according to ASTM D 1894.
By setting μ≦0.2 at 0° C., it is possible to prevent fusion, poor running, and thermal transfer of the ink layer during speed difference recording between the ink layer and the image-receiving layer.

2. By using a recording medium containing particulate dye or having a two-layer (one-layer) multi-capacity, it is possible to perform good multi-recording in which the recording density does not decrease even when the number of n increases in n-time mode recording. becomes.

Claims (2)

[Claims] (1) Layer the dye-sublimation thermal transfer material and the image-receiving sheet under the conditions of [image-receiving sheet speed]/[recording medium speed]>1 or [image-receiving sheet feed amount]/[recording medium feed amount]>1. In a sublimation thermal transfer body used in a recording method in which thermal printing is performed from the back side of the recording medium while the recording body is running and the dye in the transfer body in that area is transferred onto the image receiving sheet, the coefficient of kinetic friction of the sublimation thermal transfer body with respect to the image receiving sheet is The coefficient at 80°C is 0.20 when measured according to ASTM D1894.
A sublimation type thermal transfer material characterized by the following: (2) The sublimation thermal transfer material has an ink layer containing particulate sublimable dye in an organic binder on the substrate, or a dye supply layer consisting of a sublimable dye and an organic binder in order from the substrate side. Claim (1) comprising an ink layer formed by laminating layers.
The sublimation type thermal transfer material described above.