JP2006095985A - Cyan dye, ink using the dye, and thermal transfer sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new cyan dye which can form an image excellent in image stability and image density when the cyan dye is used for a heat sensitive sublimation dye transfer system. <P>SOLUTION: The cyan dye is expressed by general formula (I) (wherein R<SB>1</SB>and R<SB>2</SB>each represent a hydroxyl group; R<SB>3</SB>represents a 3-8C alkyl group, a 3-8C cycloalkyl group, a 3-8C alkoxyalkyl group, a 3-8C alkenylalkyl group or a 3-8C aryl group; and R<SB>4</SB>represents an amino group). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a novel cyan dye.

Various compounds are conventionally known as cyan dyes and are used in various applications.
For example, a sublimable dye is used as a color material in the thermal sublimation transfer method. The heat-sensitive sublimation transfer method uses a thermal transfer film that carries a dye layer in which a sublimable dye is dissolved or dispersed in a binder resin on a base material, and this thermal transfer film is layered on the image-receiving film to transfer image information to a heating device such as a thermal head. By applying energy according to the above, the sublimation dye contained in the dye layer on the thermal transfer film is transferred to the image receiving film to form an image.

  This heat-sensitive sublimation transfer method can control the amount of dye transfer in dot units according to the amount of energy applied to the thermal transfer film, and is therefore excellent in the formation of gradation images and has the advantage of easy formation of characters, symbols, etc. Have.

  The image obtained by such a thermal transfer method can form a high-quality image similar to a silver salt photograph, and accordingly, there is an extremely high demand for prevention of image quality degradation due to factors such as light, heat, and humidity of the image. It's getting higher.

  Conventionally, new dyes have been developed to improve image storability, but none of them can sufficiently satisfy both storability and print density. Furthermore, even when light resistance is sufficient when an image is formed using a single dye, there is a phenomenon (catalytic fading) that light resistance is inferior when combined with other dyes in the image layer. It is a problem. For example, when comparing the light resistance of yellow, cyan, and green (comprising a mixture of yellow and cyan), the yellow component and cyan component in green may be significantly worse than the light resistance level of yellow and cyan. .

で表されるSolvent Blue 63が知られている。しかしながら、このシアン染料は上記要求を満足するものではない。 As a thing which has a structure close | similar to the cyan dye which this application intends to provide, for example, the following structure:

Solvent Blue 63 represented by is known. However, this cyan dye does not satisfy the above requirements.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a novel cyan dye, particularly a cyan dye capable of forming an image having excellent image storage stability and image density when used in a heat-sensitive sublimation transfer method. It is.

（式中、Ｒ_１、Ｒ_２は水酸基を表す；Ｒ_３は炭素原子数３〜８の、アルキル基、シクロアルキル基、アルコキシアルキル基、アルケニルアルキル基またはアリール基を表す；Ｒ_４はアミノ基を表す）を提供するものである。 That is, the present invention provides a cyan dye represented by the following general formula (I):

Wherein R ₁ and R ₂ represent a hydroxyl group; R ₃ represents an alkyl group, cycloalkyl group, alkoxyalkyl group, alkenylalkyl group or aryl group having 3 to 8 carbon atoms; R ₄ represents an amino group Represents).

In the general formula (I), R ₃ represents an alkyl group, a cycloalkyl group, an alkoxyalkyl group, an alkenylalkyl group or an aryl group having 3 to 8 carbon atoms.

  As the alkyl group, an optionally branched alkyl group having 3 to 8 carbon atoms, preferably a propyl group, butyl group or pentyl group, more preferably n-, which may be branched having 3 to 5 carbon atoms. A butyl group, an iso-butyl group, a sec-butyl group, and a 1-ethylpropyl group.

  The cycloalkyl group is a cyclohexyl group, preferably a cyclohexyl group, which may have a substituent of a methyl group or an ethyl group. The alkoxyalkyl group is a propyl group to which a methoxy group or an ethoxy group is bonded, preferably a methoxypropyl group.

  Examples of alkenylalkyl include an allyl group.

  As the aryl group, a phenyl group is preferable.

The cyan dye represented by the general formula (I) can be synthesized by the following reaction formula.

  The synthesis method represented by the above reaction formula will be explained. In the first step, one chlorine of one of dichloroquinizarine is more selectively substituted with amine, so that the amount of amine used, reaction temperature, and time must be controlled. There is. The preferred amount is 2 to 4 molar ratio to dichloroquinizarine, the reaction temperature is 100 to 125 ° C., the reaction time is 1 to 3 hours, and a purple monoamino-substituted product is mainly produced.

  In the second step, one chlorine remaining in the previous step is replaced with p-toluenesulfonamide. The amount of p-toluenesulfonamide used is 4 to 6 molar ratio to the raw material, the reaction temperature is 150 to 165 ° C., and the reaction time is 3 to 6 hours.

  In both the first and second steps, an inert cellosolve, glycol, alcohol, and chlorobenzene are used alone or as a mixture.

In the third step, the sulfoamide derivative obtained in the previous step is hydrolyzed in concentrated sulfuric acid to be converted into an amino group. The concentration of sulfuric acid used is 90 to 94%, and the amount used is 7 to 12 times that of the raw material, and the reaction proceeds easily at room temperature.
If this sulfuric acid solution is added to 7 to 10 times the amount of ice water, the desired cyan dye can be precipitated.

  The cyan dye represented by the general formula (I) of the present invention can be applied to a color material or the like in a thermal sublimation transfer system. Below, the example which applied the cyan dye represented by general formula (I) of this invention to the thermal transfer sheet is demonstrated.

The thermal transfer sheet is formed by providing a dye layer on at least one surface of a base film and a heat-resistant slip layer (back layer) on the other surface.

  The base film constituting the thermal transfer sheet may be any film as long as it has a conventionally known degree of heat resistance and strength. For example, it has a thickness of about 0.5 to 50 μm, preferably about 1 to 10 μm. Polyethylene terephthalate film, 1,4-polycyclohexylenedimethylene terephthalate film, polyethylene naphthalate film, polyphenylene sulfide film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, cellulose acetate, etc. In addition to cellulose derivatives, polyethylene film, polyvinyl chloride film, nylon film, polyimide film, ionomer film, etc. It may be paper such as raffin paper or paper, or a cloth made of paper, a nonwoven fabric and a resin.

  The dye layer is formed on one side of the base film with a dye (including the cyan dye of the present invention), a binder resin, and an additive as necessary, for example, a release agent such as silicone oil or phosphate ester, or polyethylene wax. Dispersion (ink) in which organic fine particles and inorganic fine particles such as those added are dissolved in an appropriate organic solvent such as toluene, methyl ethyl ketone, ethanol, isopropyl alcohol, cyclohexanone, DME, or dispersed in an organic solvent or water Can be formed by applying and drying by means of a gravure printing method, a screen printing method, a reverse roll coating printing method using a gravure plate, or the like.

  Examples of preferable binder resins for supporting the above dyes include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, and cellulose tributyrate, polyvinyl alcohol , Vinyl resins such as polyvinyl acetate, polyvinyl butyral, polyvinyl acetoacetal and polyvinyl pyrrolidone, acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyurethane resins, polyamide resins and polyester resins It is done. Among these, cellulose-based, vinyl-based, acrylic-based, urethane-based, and polyester-based resins are preferable from the viewpoints of heat resistance, dye transferability, and the like.

Coating amount drying 0.2~5.0g / ^{m 2} in solid standard dye layer, preferably about 0.3 to 2.0 g / ^{m 2,} also sublimable dye in the dye layer, the dye It is suitable to be present in an amount of 5 to 90% by weight, preferably 10 to 70% by weight of the weight of the layer. When the dye layer to be formed is a full-color image, further, for example, an appropriate magenta and yellow (further, if necessary) is selected, and yellow, magenta and cyan (including the cyan dye of the present invention) are selected. ) Further, if necessary, a black dye layer is formed. Conventionally known dyes such as yellow and magenta may be used. As for cyan, a known dye and the cyan dye of the present invention can be mixed and used.

The heat resistant slipping layer is provided for the purpose of preventing thermal fusion between a heating device such as a thermal head and a substrate film, smooth running, and removing deposits on the thermal head. A well-known thing can be used as a heat-resistant slipping layer, It does not specifically limit. In order to form the back layer, an appropriate known binder resin, and other materials such as inorganic fillers and lubricants, if necessary, are dissolved or dispersed in a binder solvent to prepare a coating solution. It is formed by coating with a conventional coating method such as roll coater or wire bar and drying. The coating amount of the back layer is a dry solid basis at 0.1 to 3.0 g / ^{m 2,} preferably to form a back layer having a sufficient performance at a thickness of 0.1 to 2.0 g / ^{m 2} .

  The image receiving sheet, which is a transfer material used for forming an image using a thermal transfer sheet, may be any material as long as its recording surface has dye acceptability with respect to the above dyes. In the case of non-receptive paper, metal, glass, synthetic resin, etc., a dye receptive layer may be formed on at least one surface thereof. As a printer used when performing thermal transfer using a thermal transfer sheet and an image receiving sheet, a known thermal transfer printer can be used as it is, and is not particularly limited.

（１）第１工程
反応フラスコに５,８−ジクロルキニザリン４６．４ｇ、シクロヘキシルアミン４５ｇ、酢酸ナトリウム１６．４ｇおよび溶媒としてイソブタノール２００ｇとメチルセロソルブ５０ｇを仕込んだ。内容物を混合、加熱し、１１０〜１１５℃で３時間反応した。
反応マスを室温まで冷却し、吸引濾過、ケーキはメタノール洗浄および湯洗を行ない、１００℃で乾燥した。中間体の得量は３９．６ｇ（収率７１％）であった。 (Synthesis Example 1)

(1) First Step 46.4 g of 5,8-dichloroquinizarin, 45 g of cyclohexylamine, 16.4 g of sodium acetate and 200 g of isobutanol and 50 g of methyl cellosolve as a solvent were charged in a reaction flask. The contents were mixed and heated, and reacted at 110 to 115 ° C. for 3 hours.
The reaction mass was cooled to room temperature, suction filtered, the cake was washed with methanol and hot water, and dried at 100 ° C. The yield of the intermediate was 39.6 g (yield 71%).

(2) Second Step 32.2 g of the intermediate obtained in the previous step, 74 g of p-toluenesulfonamide, 14.2 g of sodium acetate, and 100 g of diethylene glycol monomethyl ether and 50 g of o-dichlorobenzene were charged as solvents. . The contents were mixed and heated and reacted at 160 to 165 ° C. for 5 hours.
The reaction mass was cooled to room temperature and suction filtered, and the cake was washed with methanol and hot water, and dried at 100 ° C. The yield of this second intermediate was 25 g (yield 57%).

(3) Third Step 250 g of 93% sulfuric acid was placed in a beaker, and 25 g of the second intermediate obtained in the previous step was gradually added over about 30 minutes while stirring. It stirred for 2 hours after completion | finish of addition. 2.5 kg of ice water was put into a beaker, and the sulfuric acid solution was poured in a trickle while stirring. Blue pigment crystals precipitated and precipitated.
The precipitate was filtered off, washed and dried at 100 ° C. The yield of the target dye (5-amino-8-cyclohexylaminoquinizarin) was 17 g (yield 98%).

The dimethylformamide solution of this dye had a λmax of 654 nm and a molecular extinction coefficient of 27500. On the other hand, the elemental analysis result was very close to the calculated value from the composition formula.
C H N
Experimental value 68.01% 5.60% 8.02%
Calculated value 68.17% 5.72% 7.95%

（１）第１工程
反応フラスコに５,８−ジクロルキニザリン７７．３ｇ、第２ブチルアミン３７ｇ、酢酸ナトリウム２６ｇおよび溶媒としてジエチレングリコールモノメチルエーテル１８０ｇを仕込んだ。内容物を混合、加熱し、１２０〜１２４℃で３時間反応した。
反応マスを放冷し７０℃でメタノール１００ｇを加え、室温まで冷却し、吸引濾過、ケーキはメタノール洗浄および湯洗を行ない、７０℃で乾燥した。この中間体の得量は６４．５ｇ（収率７５％）であった。 (Synthesis Example 2)

(1) First Step 77.3 g of 5,8-dichloroquinizarine, 37 g of secondary butylamine, 26 g of sodium acetate and 180 g of diethylene glycol monomethyl ether as a solvent were charged in a reaction flask. The contents were mixed and heated, and reacted at 120 to 124 ° C. for 3 hours.
The reaction mass was allowed to cool, 100 g of methanol was added at 70 ° C., cooled to room temperature, suction filtration, the cake was washed with methanol and hot water, and dried at 70 ° C. The yield of this intermediate was 64.5 g (75% yield).

(2) Second Step 34.5 g of the intermediate obtained in the previous step, 86 g of p-toluenesulfonamide, 16.4 g of sodium acetate, and 60 g of diethylene glycol and 100 g of o-dichlorobenzene were charged as solvents. The contents were mixed and heated and reacted at 160-168 ° C. for 6 hours.
The reaction mass was cooled to room temperature and suction filtered, and the cake was washed with methanol and hot water, and dried at 100 ° C. The yield of this second intermediate was 26.3 g (yield 55%).

(3) Third Step 250 g of 93% sulfuric acid was placed in a beaker, and 25 g of the second intermediate obtained in the previous step was gradually added over about 30 minutes while stirring. It stirred for 2 hours after completion | finish of addition. 2.5 kg of ice water was put into a beaker, and the sulfuric acid solution was poured in a trickle while stirring. Blue pigment crystals precipitated and precipitated.
The precipitate was filtered off, washed and dried at 100 ° C. The yield of the target dye (5-amino-8-secondary butylaminoquinizarin) was 16.5 g (yield 97%).

The dimethylformamide solution of this dye had a λmax of 652 nm and a molecular extinction coefficient of 31700. On the other hand, the elemental analysis result was very close to the calculated value from the composition formula.
C H N
Experimental value 66.38% 5.33% 8.42%
Calculated value 66.25% 5.55% 8.58%

Example 1
As a base material, a polyethylene terephthalate film (PET) having a thickness of 6 μm and an easy adhesion treatment (Diafoil K203E, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.) was used. The surface of the surface opposite to the easy-adhesion treated surface is preliminarily coated with a heat resistant slipping layer composition liquid (a) having the following composition by gravure coating, and dried so that the dry coating amount is 1.0 g / m ² . A layer was formed.

A dye layer composition liquid A having the following composition was applied to the easy-adhesion treated surface by gravure coating so that the dry coating amount was 0.8 g / m ² and dried to form a dye layer to prepare a thermal transfer sheet.

<Dye layer composition liquid A>
Cy dyes listed in Table 1 1.5 parts polyvinyl butyral resin (S-REC BX-5, manufactured by Sekisui Chemical Co., Ltd.) 3.0 parts methyl ethyl ketone 47.7 parts toluene 47.8 parts

<Heat resistant slipping layer composition liquid (a)>
Polyvinyl butyral resin (ESREC BX-1 manufactured by Sekisui Chemical Co., Ltd.) 13.6 parts polyisocyanate curing agent (Takenate D218 manufactured by Takeda Pharmaceutical Co., Ltd.) 0.6 parts phosphoric acid ester (Plysurf A208S Daiichi Kogyo Seiyaku Co., Ltd.) 0.8 parts methyl ethyl ketone 42.5 parts toluene 42.5 parts

(Examples 2-7, Comparative Examples 1-4)
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the Cy dye was changed to that shown in Table 1 in Example 1.

(Evaluation)
Using the thermal transfer sheets prepared in each Example and Comparative Example, each evaluation of printing density, light resistance, heat resistance, moisture resistance, and dye transfer to a heat resistant slipping layer was performed by the following methods.

(Print)
Printing was performed under the following conditions, and the density of the obtained print was measured.
The thermal transfer sheets prepared in Examples and Comparative Examples were printed using a card photo printer CP-200 manufactured by Canon Inc., and the density of the printed part was measured using a Macbeth densitometer RD-918 (manufactured by Sakata Inx Corporation). It was measured. The thermal transfer sheet is cut and pasted on the cyan panel of genuine media (color ink / paper set KL-36IP), and cyan and black (genuine media yellow + genuine media magenta + cyan mixed color of the present invention) Key values 17/255, 34/255, 51/255, 68/255, 85/255, 102/255, 119/255, 136/255, 153/255, 170/255, 187/255, 204/255, Printing was performed with a 15-tone printing pattern of 221/255, 238/255, and 255/255 (density max). Printing was performed in an environment of 30 ° C. and 50%. As the image receiving sheet, genuine media (color ink / paper set KL-36IP paper) was used.

(Print density)
In the above prints, the cyan tone value of 255/255 parts was measured and compared with the value of the reference ribbon (the ribbon of Comparative Example 1) and ranked as follows. The results are summarized in Table 1.
A: The density is 105% or more. B: The density is 95% or more and less than 105%. X: The density is less than 95%.

(Light resistance evaluation)
In the above-mentioned printing, cyan and black gradation values 119/255, 170/255, 255/255 are measured in advance, and Ci4000 Xenon Weather-Ometer manufactured by ATLAS (filter: soda lime / CIRA, xenon lamp, 400 kJ) A forced deterioration test was performed (accumulated light of 420 nm) and 30 ° C. and 30% environment). For the sample after irradiation, the same gradation value portion measured before irradiation was measured.
In comparison with the reference ribbon, the ranking was as follows. The results are summarized in Table 1.

A: Color difference ΔE * ab is smaller than the standard at all measurement points (good)
○: Color difference ΔE * ab is small and large compared to the standard (equivalent)
×: The color difference ΔE * ab is larger than the standard at all measurement points (defect)

Colorimetry was measured with Gretag Spectrolino (D65 light source, viewing angle 2 °) manufactured by Gretag, and the color difference was calculated according to the following formula.
ΔE * ab =
((Difference in L value before and after irradiation) ² + (difference in a value before and after irradiation) ² + (difference in b value before and after irradiation) ² ) ^1/2

(Heat resistance evaluation)
In the above prints, cyan tone values of 119/255, 170/255, and 255/255 parts were measured and stored in an environment of 60 ° C. and 60% for 4 weeks. For the sample after storage, the same gradation value portion measured before irradiation was measured. Note that the colorimetry was performed using the same method as in the light resistance evaluation.
In comparison with the reference ribbon, the ranking was as follows. The results are summarized in Table 1.

A: Color difference ΔE * ab is smaller than the standard at all measurement points (good)
○: Color difference ΔE * ab is small and large compared to the standard (equivalent)
×: The color difference ΔE * ab is larger than the standard at all measurement points (defect)

ΔE * ab =
((Difference between L values before and after saving) ² + (difference between a values before and after saving) ² + (difference between b values before and after saving) ² ) ^1/2

(Evaluation of dye transfer to heat-resistant slipping layer)
The dye transfer property to the heat resistant slipping layer was evaluated under the following conditions.
The dye layer and the heat-resistant slip layer of the thermal transfer sheet prepared in Examples and Comparative Examples were opposed to each other and stored for 96 hours in a 20% environment at 40 ° C. under a load of 20 kg / cm ² . The heat-resistant slipping layer was obtained by coating and drying the heat-resistant slipping layer composition liquid (a) of Example 1 on the PET substrate used in Example 1 under the conditions of Example 1 (formation of dye layer). Did not.) Evaluation of dye transfer to the heat resistant slipping layer was performed based on the following criteria. The colorimetry and color difference were calculated using the same method as in the light resistance evaluation. The results are summarized in Table 1.

○: Color difference ΔE * ab between the heat-resistant slipping layer before and after facing the dye layer is less than 1.5 Δ: Color difference ΔE * ab between the heat-resistant slipping layer before and after facing the dye layer is 1.5 or more Less than 3.0 ×: The color difference ΔE * ab between the heat-resistant slipping layer before and after facing the dye layer is 3.0 or more

Claims (3)

Cyan dye represented by the following general formula (I):

Wherein R ₁ and R ₂ represent a hydroxyl group; R ₃ represents an alkyl group, cycloalkyl group, alkoxyalkyl group, alkenylalkyl group or aryl group having 3 to 8 carbon atoms; R ₄ represents an amino group Represents).   An ink containing at least the cyan dye according to claim 1, a binder resin, and an organic solvent. A thermal transfer sheet comprising a dye-carrying layer on at least one surface of a substrate sheet, wherein the dye-carrying layer contains at least the cyan dye according to claim 1.