JPH0383687A - Thermal transfer recording material - Google Patents

Abstract

PURPOSE:To improve heat diffusibility, a hue, heat resistance and light fastness and to also improve fixing properties by providing a thermal layer containing a dye compound represented by a specific general formula on a support to form a thermal transfer recording material. CONSTITUTION:A dye compound represented by formula I (wherein R<1> and R<2> are a halogen atom, an alkyl group, a cycloalkyl group or an aryl group, m is an integer of 1 - 4, n is 0 or an integer of 1 - 4 and R<1> and R<2> may be same or different when n is 2 - 4) is dissolved in a solvent along with a binder such as a cellulosic water-soluble polymer to prepare dye-containing ink. This ink is applied to a support such as tissue paper or a plastic film and dried to form a thermal layer to obtain a thermal transfer recording material. The use amount of the aforementioned dye compound is pref. about 0.1 - 20g per 1m<2> of the support.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a heat-sensitive transfer material, and more specifically, a new heat-sensitive transfer material containing a cyan dye with excellent spectral properties, heat resistance, and fixing properties; This invention relates to an image forming method using dyes.

[Background of the Invention] Color recording techniques such as inkjet, electrophotography, and thermal transfer are being considered as methods for obtaining color hard copies.

Among these, the thermal transfer method in particular has advantages such as ease of operation and maintenance, miniaturization of the device, and low cost, and low running costs for the thermal transfer method.

In this thermal transfer method C, a transfer sheet (also referred to as a thermal transfer material) having a meltable ink layer on a support is heated by a thermal head, and the ink is transferred onto a transfer sheet (also referred to as an image receiving material). A method of melt transfer and a thermal diffusion method in which a transfer sheet having an ink layer containing a heat-diffusible dye (sublimable dye) on a support is heated by a thermal head to transfer the heat-diffusible dye to a transfer sheet. There are two types of transfer methods (sublimation transfer method), but this thermal diffusion transfer method controls the gradation of the image by changing the amount of dye transferred in response to changes in the thermal energy of the thermal head. This is advantageous for full-color recording.

By the way, in thermal transfer recording using the thermal diffusion transfer method,
The dye used in thermal transfer materials is important, and has a major impact on transfer recording speed, image quality, image storage stability, etc.

Therefore, the dye used in the thermal diffusion transfer method described above must have the following properties.

(1) Easy thermal diffusion (sublimation) under thermal recording conditions (head temperature, head heating time).

(2) It has a hue favorable for color reproduction.

(3) Do not thermally decompose at the heating temperature during recording.

(4) Good light resistance, heat resistance, moisture resistance, chemical resistance, etc.

(5) It has a large molar extinction coefficient.

(6> Easily added to heat-sensitive transfer materials.

(7) Easy to synthesize.

In addition to this, excellent image fixing properties are required.

Conventionally, as a cyan dye for thermal transfer materials, JP-A-59
-78896, 59-227948, 80-2
No. 4996, No. 60-53563, No. 60-1307
No. 35, No. 60-131292, No. 60-23928
No. 9, No. 61-19396, No. 61-22993,
No. 61-31292, No. 61-31467, No. 61
-35994, 61-49893, 61-14
No. 8269, No. 62-191191, No. 63-912
No. 88, No. 63-91287, No. 63-290793
Naphthoquinone dyes, anthraquinone dyes, azomethine dyes, etc. have been disclosed in various publications such as No. 1, but no dye has been found that satisfies all of the above properties. A dye that satisfies properties such as color stability and light resistance and also has good fixing properties has not yet been found.

Therefore, the present inventors have continued various studies on dyes for thermal transfer materials and image forming methods using the dyes based on the above-mentioned viewpoint, and have surprisingly found that the dyes of the general formula [11] The present invention has been completed based on the discovery that the present invention satisfies the following requirements and has particularly excellent fixing properties.

[Object of the Invention] Therefore, the object of the present invention is to provide a heat-sensitive transfer using a cyan dye that satisfies the above-mentioned properties, particularly thermal diffusivity, hue, heat resistance, light resistance, etc., and has significantly improved fixing properties. An object of the present invention is to provide a material and an image forming method using the dye.

[Structure of the Invention] The objects of the present invention are as follows: 1) A heat-sensitive transfer recording material characterized by having a heat-sensitive layer containing at least a dye compound represented by the general formula [I] on a support, and a heat-sensitive transfer recording material of the general formula [! ] [In the formula, RI R2 is 1. Halogen atom, alkyl group, cycloalkyl group, aryl group, alkenyl group, aralkyl group, alkoxy group, aryloxy group, cyano group, acylamino group, alkylthio group, arylthio group,
It represents a sulfonyla group, a ureido group, a carbamoyl group, a sulfamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfonyl group, an acyl group, and an aryl group.

m represents an integer of 1 to 4, and n represents an integer of 0, 1 to 4. Further, when m or n is 2 to 4, R1 or R2 may be the same or different. Furthermore, those substituents may combine with each other to form a carbocycle or a heterocycle.] 2) A heat-sensitive transfer material having a heat-sensitive layer containing at least a dye compound represented by the general formula [11] on a support. distant relatives by a thermal transfer image forming method characterized by heating the support from the back side according to the image information to form an image of the dye compound on the image-receiving material in the presence of a basic compound and/or a mordant. It was done.

The present invention will be explained in more detail below.

In the general formula [I], RI R2 is a hydrogen atom, a halogen atom (e.g. chlorine atom, fluorine atom, etc.), an alkyl group (e.g. methyl group, ethyl group, isopropyl group, n-
butyl group), cycloalkyl group (e.g. cyclopentyl group, cyclohexyl group, etc.), aryl group (e.g. phenyl group, etc.), alkenyl group (e.g. 2-propenyl group, etc.)
, aralkyl groups (e.g. benzyl group, 2-phenethyl group, etc.), alkoxy groups (e.g. methoxy group, ethoxy group,
isopropoxy group, n-butoxy group, etc.), aryloxy group (e.g., phenoxy group, etc.), cyano group, acylamino group (e.g., acetylamino group, propionyl group, etc.), alkylthio group (e.g., methylthio group, ethylthio group, n-butylthio group, etc.), arylthio group (e.g. phenylthio group), sulfonylamino group (e.g. methanesulfonylamino group, benzenesulfonylamino group, etc.)
, ureido group (e.g. 3-methylureido group, 3.3-
dimethylureido group, 1,3-dimethylureido group, etc.)
, carbamoyl group (e.g. methylcarbamoyl group, ethylcarbamoyl group, dimethylcarbamoyl group, etc.), sulfamoyl group (e.g. ethylsulfamoyl group, dimethylsulfamoyl group, etc.), alkoxycarbonyl group (e.g. methoxycarbonyl group, ethoxycarbonyl group, etc.) )
, aryloxycarbonyl group (e.g., phenoxycarbonyl group, etc.), sulfonyl group (e.g., methanesulfonyl group, butanesulfonyl group, phenylsulfonyl group, etc.),
It represents an acyl group (for example, an acetyl group, a propanoyl group, a butyroyl group, etc.), an amino group (mainly methyla group, an ethylthio group, a dimethylamino group, etc.).

These groups may be further substituted, and examples of such substituents include alkyl groups (e.g. methyl group, ethyl group, trifluoromethyl group, etc.), aryl groups (e.g. phenyl group etc.), alkoxy groups (e.g. methoxy group, etc.). group, ethoxy group, etc.), amino group (e.g., methylamino group, ethyl group, etc.), acylamino group (e.g., acetyl group, etc.), sulfonyl group (e.g., methanesulfonyl group, etc.), alkoxycarbonyl group (e.g., methoxycarbonyl group) , a cyano group, a nitro group, a halogen atom (for example, a chlorine atom, a fluorine atom, etc.).

Further, the group represented by these RI R2 (including the substituent when it has a substituent) preferably has 12 or less carbon atoms (particularly preferably 8 or less).

The compound represented by the general formula [I] (hereinafter referred to as the compound used in the present invention) is particularly preferably represented by the following general formula [II].

General formula [11] [In the formula, 3 represents an alkyl group (e.g., methyl group, ethyl group, isopropyl group, etc.), a cycloalkyl group (e.g., cyclopentyl group, cyclohexyl group, etc.), an aryl group (e.g., phenyl group, etc.), R4 represents a main group (e.g., methylamino group, ethylamino group, etc.), dialkylamino group (e.g., dimethylamino group, diethylamino group, etc.), or an aryl group (e.g., phenylah group), and R4 is , alkyl groups (e.g. methyl group, ethyl group, isopropyl group, butyl group, etc.), acylamino groups (e.g. acetylamino group, propionylamino group, etc.)
or represents a hydrogen atom, R8 is an alkyl group (e.g. methyl group, ethyl group, etc.),
represents an acylamino group (eg, an acetylamino group, a propionyl group, etc.), a halogen atom (eg, a chlorine atom, a fluorine atom, etc.), or a hydrogen atom. Furthermore, R4 and R11 may be bonded together to form a 5- to 6-membered ring.] These groups may be further substituted, and examples of the substituent include an alkyl group (e.g., methyl group, ethyl group). group, trifluoromethyl group, etc.), aryl group (e.g., phenyl group, etc.), alkoxy group (e.g., methoxy group, ethoxy group, etc.), aryl group (e.g., methyla group, ethyl ano group, etc.), acylamino group (eg, acetyl group, etc.), sulfonyl group (eg, methanesulfonyl group, etc.), alkoxycarbonyl group (eg, methoxycarbonyl group), cyano group, nitro group, halogen atom (eg, chlorine atom, fluorine atom, etc.), and the like.

Further, the group represented by R3R4R8 (including the substituent when it has a substituent) preferably has 12 or less carbon atoms (particularly preferably 8 or less).

R2 represents the same as R2 represented by formula [I]; p represents 1 or 2;

The compounds used in the present invention include phenol derivatives and p-
It is synthesized by oxidative coupling of achnophenol derivatives.

Conventionally known compounds are obtained by oxidative coupling with p-phenylenediamine derivatives, whereas the compounds used in the present invention are obtained by oxidative coupling with p-phenol derivatives. ,
Therefore, by having a phenolic hydroxyl group, fixing properties are improved.

Next, typical compound examples of the dye represented by the general formula [I] used in the present invention will be shown, but the present invention is not limited thereto.

The following margins ye-1 ye-2 ye-3 υ■ Dye-4 Dye-5 Dye-6 s■ Dye-7 Dye-8 Dye-9 sn Dye-10 Dye-11 Dye-12 l11 Dye-13 n Dye-14 Dye-15 Dye-16 Dye-17 Dye-18 Sun Dye-19 Dye-20 Dye-21 Su■ υn Dye-22 tt Dye-23 Sun Dye-24 Dye-25 Dye-26 Dye- 27 Sun Dye-28 Dye-29 Dye-30 U+t υn Dye-31 Dye-32 Dye-33 Sun Dye-34 Dye-35 Dye-36 Dye-37 The compound used in the present invention can be used under basic conditions. In this case, it gives a good cyan hue, but on the acidic side, it shifts to a shallow color and becomes a red to purple hue. Therefore, although it is possible to form an image by transferring the compound used in the present invention alone, a clear cyan image can be obtained by forming an image in the presence of a basic compound in the image-receiving layer.

Furthermore, the compound used in the present invention gives a good cyan hue when used in a mordant, regardless of the presence or absence of a basic compound. Therefore, it is preferable to form an image in the presence of a basic compound and/or a mordant in the image-receiving layer.

In particular, the method of forming an image in the presence of a mordant improves fixability by mordanting the dye with the mordant.
More preferable.

In the present invention, the basic compound and/or mordant are added to the image-receiving material (usually referred to as the image-receiving layer), but when the heat-sensitive transfer material has a two-layer structure as described below, the basic compound and/or mordant are added to the heat-fusible layer. Good too. Further, a basic compound may be added to the ink layer; in such a case, it is not necessary for the image-receiving layer to contain the basic compound and/or mordant.

The basic compound used in the present invention is not particularly limited, but inorganic or organic basic compounds are used, such as calcium carbonate, sodium carbonate, sodium acetate,
Examples include alkylamines, aryl amines, and the like.

In the present invention, it is preferable to use a mordant, and it is particularly preferable to add a mordant to the image-receiving layer.

The mordant used in the present invention includes a compound having a tertiary amino group, a compound having a nitrogen-containing heterocyclic group, and a compound having a quaternary cation group thereof.

When a mordant is used in the image-receiving layer, it is preferable that the mordant is immobilized, and a polymer mordant is particularly preferable, and when the mordant is added to the heat-melting layer of the heat-sensitive transfer material, a mordant with a molecular weight of 400 or less is used. is preferred.

As a polymer mordant, it receives images by itself.

Although it may constitute a layer, it is usually used in conjunction with other suitable binders to constitute the image-receiving layer. Examples of the binder include those made of heat-resistant organic polymeric substances having a glass transition point of 40° C. or higher and 250° C. or lower, as described in JP-A-57-207250 and the like. These polymers are usually supported on a support as an image-receiving layer, but they may also serve as a support themselves.
randrup, E.) I, Immergut (ed.)
Also useful are platform polymers with glass transition temperatures of 40° C. or higher, as described in the John Wiley & 5ons publication.

As a polymer mordant, JP-A No. 48-28325,
No. 54-74430, No. 54-124726, No. 5
No. 5-22766, No. 55-142339, No. 55-
No. 23850, No. 60-23851, No. 60-238
No. 52, No. 60-23853, No. 60-57836, No. 60-60643, No. 60-118834, No. 60-122940, No. 80-122941, No. 6
No. 0-122942, No. 60-235134, U.S. Patent No. 2,484,430, U.S. Patent No. 2,548°564,
3,148. Oat No. 3,148.161, No. 3,309,690, No. 3゜756.814, rM
J3,898,088, J3,958,995, J4,115,124, J4,124,386, J4
, No. 193,800, No. 4,273,853, No. 4,
Selected from those described in the specifications of No. 282.305, No. 4,450,224, British Patent No. 1,594,981, British Patent No. 2,056.101, British Patent No. 2,093,041, etc. However, for example, the following polymer mordants can be used.

First, examples of the polymer mordant having a tertiary amino group include the following polymers.

Hereinafter, specific representative examples of the mordant used in the present invention will be listed, but the present invention is not limited to these examples.

(Numbers represent mol%) -1 -2 -3 -tC1i (:Hz j- -4 H3 As the nitrogen-containing heterocyclic group, an imidazole group and a pyridyl group are preferable, and specific examples of the polymer mordant having a grid include The following polymers may be mentioned.

-5 +CHxCH+ro.

-6- 7- -9 -10 -1 1 P-12 P-13 -14 -15 Specific examples of the polymer mordant having a quaternary ammonium group include the following polymers.

-16 Cl1s-N”-C1(.

Cl- -17 CHs N" CHs l- -18 -19 -20 -21 ans P-22 P-23 i- The thermal transfer material of the present invention is characterized in that the dye is dissolved in a solvent together with a binder or in the form of fine particles. An ink layer or a heat-sensitive layer is obtained by preparing an ink containing a pigment by dispersing it, applying the ink onto a support, and drying it.

The amount of the dye used in the present invention is preferably 0.1 to 20 g per m2 of support.

The image forming method using the heat-sensitive transfer material obtained in this way involves preparing the image-receiving material, aligning the heat-sensitive layer and the image-receiving layer surface, and then applying heat from the back side of the support of the heat-sensitive transfer material according to the image information. When applied, the dye corresponding to this thermal image diffuses into the image-receiving layer, where the dye is fixed and a dye image is obtained.

The binder includes water-soluble polymers such as cellulose, polyacrylic acid, polyvinyl alcohol, and polyvinylpyrrolidone, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone,
There are polymers that are soluble in organic solvents, such as polyether sulfone and ethyl cellulose. When using polymers that are soluble in organic solvents, they are not only dissolved in organic solvents, but also
It may also be used in the form of a latex dispersion.

The amount of binder used is 0.1 per 11 supports.
g to sog are preferred.

The support used in the present invention may be any material as long as it has good dimensional stability and can withstand the heat during recording with a thermal head, including thin paper such as condenser paper, glassine paper, polyethylene terephthalate, polyamide, etc. A heat resistant plastic film such as polycarbonate can be used.

The thickness of the support is preferably 2 to 30 μm, and the support may have a subbing layer for the purpose of improving adhesion with the binder and preventing transfer and dyeing of the dye to the support. good.

Furthermore, a slipping layer may be provided on the back surface of the support (the side opposite to the ink layer) for the purpose of preventing the head from adhering to the support.

The ink layer, ie, the heat-sensitive layer, used in the present invention is coated on the support or printed on the support by a 6-printing method such as a gravure method. /! 5. The thickness of the thermal layer is 0.
A thickness of 1 μm to 5 μm is preferable.

Solvents for preparing the ink for the heat-sensitive layer include water, alcohols (e.g. ethanol, propatool), cellosolves (e.g. ethyl acetate), aromatics (e.g. toluene, xylene, chlorobenzene), ketones (e.g. acetone). , methyl ethyl ketone), ethers (eg, tetrahydrofuran, dioxane), chlorinated solvents (eg, chloroform, trichlorethylene), and the like.

The heat-sensitive transfer material of the present invention basically comprises an ink layer on a support, comprising the dye used in the present invention and a binder;
That is, it is composed of a heat-sensitive layer, but may have a heat-fusible layer containing a heat-fusible compound as described in JP-A-59-106997 on the ink layer.

Furthermore, when the thermal transfer material of the present invention is used for full-color image recording, a cyan ink layer containing a cyan dye, a magenta ink layer containing a heat-diffusible magenta dye, and a heat-diffusible yellow dye are formed on the support. It is preferable that three yellow ink layers are sequentially and repeatedly applied.

Further, in addition to the yellow, magenta, and cyan layers, an ink layer containing a black image-forming substance may be further applied as necessary, so that a total of four layers may be repeatedly applied in sequence.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited only to these examples.

Example 1 [Ink layer (heat-sensitive layer)] A mixture having the following composition was treated with a paint conditioner to obtain a uniform solution ink containing a heat-diffusible pigment used in the present invention.

Pigment compound Dye-210g Polyvinyl butyral resin 15g Methyl ethyl ketone 150 mfl Toluene 150 t*fl [Preparation of transfer sheet] The ink containing the above heat-diffusible dye was applied to a thickness of 15 μm.
A heat-sensitive transfer material -1 was produced.

Similarly, in place of Dye-2 of thermal transfer material-1,
Thermal transfer materials-2 to 7 were prepared in the same manner as the thermal transfer material-1 except that the dyes shown in Table 2 were used.

[Preparation of image-receiving material] 10 g of polyvinylpyrrolidone was dissolved in 100g of a latex dispersion containing 10% polymer mordant (P-16), and the amount of polyvinylpyrrolidone (binder) applied was 10g per 112 of the support for photographic use. Image-receiving material-8 was prepared by coating on baryta paper.

Image receiving materials B to G having the compositions shown in Table 1 were prepared in the same manner.

No. table Note) Alkaline agent is synonymous with basic compound.

[Thermal transfer image forming method] Thermal transfer sheets (1 to 7) obtained as described above and image-receiving materials (A and E) are stacked so that the ink-coated surface of the thermal transfer sheet and the image-receiving surface of the image-receiving material face each other. An image was recorded by applying a thermal head to the back side of the thermal transfer sheet. As a result, an image with excellent gradation was obtained.

Table 2 shows the maximum density of the obtained image.

The recording conditions at this time are as follows.

Linear density of main scanning and sub-scanning: 4 dots/ml11 Recording power: 0.8 W/dot Heating time of thermal head: 20 m5ec (applied energy: approx. 11.2 x 10
-'J) to 2 m5ec (applied energy approximately 1.1
The heating time was adjusted stepwise between 2 x 10-''J).

oye-h Dye-B As is clear from Table 2 below, a high density thermal transfer image can be obtained by using the method of the present invention.

Example 2 The images obtained in Example 1 (No. 1 to No. 14) were laminated with high-quality dry electrophotographic paper on the image-receiving layer side and contained dioctyl phthalate (30%) as a plasticizer. Regarding the two types, one made of overlapping polyvinyl chloride sheets,
After applying a pressure of 30 g/c++2 from above and leaving it at a temperature of 60° C. for 3 days, the high-quality paper was peeled off from the image-receiving material, and the image density retransferred onto the high-quality paper was measured.

The results obtained are shown in Table 3.

As is clear from Table 3, images with excellent fixability can be obtained by the method of the present invention.

Example 3 The same thermal transfer recording as in Example 1 was performed using the thermal transfer material and image-receiving materials A to G produced in Example 1. The density and hue of the obtained images are shown in Table 4, and the fixability (non-retransferability) of these images was determined in the same manner as in Example 2.
A test was conducted. The results are also shown in Table 4.

As is clear from Table 4, the method of the present invention provides images with high density, good hue, and excellent fixing properties. The effect is remarkable.

[Effects of the Invention] By the thermal transfer image forming method of the present invention, color images with good gradation and excellent fixing properties can be obtained.

Claims (1)

[Scope of Claims] 1) A heat-sensitive transfer recording material comprising a heat-sensitive layer containing at least a dye compound represented by the general formula [I] on a support. General formula [I] ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R^1 and R^2 are a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, an aralkyl group, an alkoxy group, Aryloxy group, cyano group, acylamino group, alkylthio group, arylthio group,
Represents a sulfonylamino group, ureido group, carbamoyl group, sulfamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, sulfonyl group, acyl group, and amino group. m represents an integer of 1 to 4, and n represents an integer of 0 and 1 to 4. Further, when m or n is 2 to 4, R^1 or R^2 may be the same or different. Furthermore, these substituents may be bonded to each other to form a carbocycle or a heterocycle. ] 2) A heat-sensitive transfer material having a heat-sensitive layer containing at least a dye compound represented by the general formula [I] on a support is heated from the back side of the support in accordance with image information, and a basic compound and a basic compound are coated on the image-receiving material. A thermal transfer image forming method comprising forming an image using the dye compound in the presence of/or a mordant.