JP2000247942A - Styryl compounds - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new styryl compound of a yellow pigment compound having excellent characteristics suitable for pigment transfer type heat-sensitive transfer recording, and having a structure for which a specified combination is selected as substituents of a substituted amino group bonded to a benzene ring. SOLUTION: A compound of formula I [Ring A is a benzene ring which may have another substituent; R1 is a 2-4C alkyl; R2 is a 5-8C alkyl; R3 is a 1-4C alkyl]. For example, a compound of formula II. The compound of formula I is, for example, obtained by formylating a compound of formula III through Vilsmeier reaction to form a compound of formula IV, then subjecting the formed compound to dehydrating condensation with malononitrile using a basic catalyst in an inert solvent. Water, an alcohol, N,N-dimethylformamide or the like is suitable for the solvent, when the dehydrating condensation is carried out. An inorganic salt, such as sodium hydroxide, and an organic amine, such as triethylamine, can be used as the basic catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel styryl compound. More specifically, the present invention relates to a yellow dye compound having a styryl-based structure and having excellent properties for dye transfer type thermal transfer recording.

[0002]

2. Description of the Related Art Conventionally, color recording technology has been demanded in printers, copiers, facsimile machines, etc.
A color recording technique using ink jet, thermal transfer, or the like is being studied. Among them, a new recording method has recently been proposed (Japanese Patent Application Laid-Open No. 7-89107). The recording liquid is guided to a transfer portion having a porous structure by a capillary phenomenon, and is heated by a suitable heating means such as a laser beam to vaporize the recording liquid or generate a mist having a diameter of 1 μm or less,
This is a non-contact type dye vaporization type thermal transfer recording system in which this is transferred onto a photographic paper which is disposed opposite to a gap of 10 to 300 μm. This method is capable of performing multi-value density gradation and obtaining high-quality recording, easy to maintain and operate the apparatus, and inexpensive consumables of the apparatus. is there. As a dye used in this recording method, a styryl dye has already been proposed (see JP-A-8-244364). However, the dye compounds specifically described in the conventional recording method do not always have sufficient performance.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a novel styryl compound, and solves the problems of kogation and recording density when used as a dye for a dye vaporization type thermal transfer recording. It is an object of the present invention to provide a yellow dye compound that can be used.

[0004]

Means for Solving the Problems As a result of various studies on the structure of a styryl compound, the present inventors have found that a specific combination is selected as a substituent of a substituted amino group bonded to a benzene ring to obtain a comparative example. It has been found that it is possible to obtain a recorded matter of a yellow color having a clearer color density than the known compounds as shown in (1). That is, the gist of the present invention resides in a styryl compound represented by the following general formula (I) and a dye comprising the same.

[0005]

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(Wherein, in the general formula (I), ring A is a benzene ring which may further have a substituent, R ₁ is an unsubstituted alkyl group having 2 to 4 carbon atoms, and R ₂ is 5-8 carbon atoms
Represents an unsubstituted alkyl group, and R ₃ represents an unsubstituted alkyl group having 1 to 4 carbon atoms.)

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the styryl compound of the present invention, R ₁ includes an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, and the like.
R ₂ is n-amyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, i-
Amyl groups and the like, and as R ₃ , a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group,
and an i-butyl group. Particularly preferred examples of R ₁ include an ethyl group, an n-butyl group, and an i-butyl group, and among them, an n-butyl group is most preferably used.
Particularly preferred examples of R ₂ include an n-hexyl group, an n-
An octyl group and a 2-ethylhexyl group are exemplified, and among them, an n-octyl group is most preferably used. A particularly advantageous R ₃ is a methyl group.

The ring A is a benzene ring which may further have a substituent, and examples of the substituent include an alkyl group having 1 to 3 carbon atoms and an alkoxy group having 1 to 3 carbon atoms. Among them, ring A is preferably a benzene ring having no further substituent. Specific examples of the styryl-based compound represented by the general formula (I) are shown in Table 1 below.

[0009]

[Table 1]

The styryl compound represented by the general formula (I) according to the present invention is represented by the following general formula (II)

[0011]

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(Wherein ring A and R _{1 to} R ₃ have the same meaning as in the above formula (I))
Formylation by the ilsmeier reaction is performed by the following general formula (II)
I)

[0013]

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(Wherein ring A and R _{1 to} R ₃ have the same meanings as in the above formula (I)), which is synthesized by dehydration condensation with malononitrile using a base catalyst in an inert solvent. can do. Suitable solvents for the dehydration condensation include water, various alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and isobutyl alcohol, and N, N-dimethylformamide. As the base catalyst, inorganic bases such as caustic soda and sodium carbonate, and organic amines such as triethylamine, pyridine and piperidine can be used. The reaction temperature can be carried out in the range of 20 to 100 ° C.

When the styryl compound of the present invention is used, for example, as a dye vaporizing dye for thermal transfer recording, the dye is treated at 50 ° C.
5% by weight or more of a boiling point of 150 to be dissolved or dispersed below
It is preferable to use a recording liquid containing a solvent (a non-aqueous solvent excluding water) at a temperature of at least ° C. Examples of the solvent for the ink include aromatic esters including dialkyl phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisopropyl phthalate, and dioctyl phthalate. Up to 30 aromatic hydrocarbons such as n-alkylbenzene, n-alkylnaphthalene, n-dialkylbenzene, and n-dialkylnaphthalene.

[0016] In addition to the above components, an antistatic agent, an antifoaming agent, an antioxidant, a viscosity modifier and the like can be added to the above-mentioned ink, if necessary. The transfer head includes a recording unit provided with a heating unit, an ink tank for storing a recording liquid, and a recording liquid passage connecting the recording unit and the ink tank. The entire transfer head can be heated to 50 ° C. in order to adjust the viscosity of the recording liquid. The recording liquid consumed in the recording unit can be continuously supplied to the recording unit through the recording liquid passage. As the heating means, a heating element such as a resistance heater, a laser whose output changes in accordance with recording information, a combination of a laser and a laser light absorber (photothermal converter) provided in a recording section, or the like can be used. When a semiconductor laser is used as the laser, a small and light head can be configured with high controllability. The resistance heater is manufactured by directly attaching a conductive substance such as polysilicon on the recording unit. The photographic paper is plain paper such as PPC paper, high-quality paper such as art paper, etc. In order to obtain a high-quality image with particularly high gradation and density, polyester, polycarbonate, etc. ,
Special paper made by applying acetate, epoxy resin, polyvinyl chloride or the like on a base paper can also be used. In order to improve the storage stability of the obtained image, it is effective to laminate a resin film on the photographic paper after transfer.

[0017]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 Compound no. Synthesis of 1 Nn-butyl-Nn-octyl-m-toluidine 1
5.6 g was dissolved in 50 ml of N, N-dimethylformamide, and 8.44 g of phosphorus oxychloride was added dropwise to the solution in about 15 minutes. At this time, the temperature of the reaction solution rose from 20 ° C to 45 ° C. After completion of the dropwise addition, the temperature was raised to 95 ° C., and the reaction was carried out at that temperature for about 1 hour. Thereafter, the reaction solution was cooled to room temperature and discharged into ice water. A 25% aqueous solution of caustic soda was added to the solution to neutralize the solution to pH 7, and then isobutanol 120
Then, the mixture was separated into an organic layer and an aqueous layer with a separating funnel, the organic layer was collected, and the collected organic layer was washed with water. To the organic layer washed with water, 3.3 g of malononitrile was added.
A time reaction was performed. After cooling to room temperature, the solvent was distilled off, and the residue was purified by column chromatography (silica gel / toluene) and dried to obtain 5.00 g of yellow crystals. Melting point, absorption maximum (λmax) and 28 ° C
The solubility in dibutyl phthalic acid was as follows.

Melting point: 56.2 ° C. λmax (in acetone): 449 nm Solubility: 34.5% The mass spectrum of this product showed a parent ion peak of 351. However, the chemical structure of this is as follows:

[0019]

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Application Example Using the dye compound of the present invention obtained in Example 1 above, a transfer recording test was carried out according to the method described in JP-A-10-258584 as follows. First, a description will be given with reference to the drawings. 1 to 4 are views showing a dye vaporization type thermal transfer printer head used in the embodiment. FIG. 1 (a) is a sectional view thereof, FIG. 1 (b) is a perspective view, FIG. 2 is a plan view, and FIG. Is a plan view showing a state in which a cover 7 described later is removed, and FIG. 4 is a partially enlarged view of a part thereof. As shown in FIGS. 1 to 3, the printer head 1 has an aluminum head base 2 also serving as a heat sink, a vaporizing section heated by a heater according to image information, and a recording liquid applied to the vaporizing section by capillary action. A recording liquid introduction path to be introduced is mounted on a silicon substrate by mounting a heater chip 3 integrally formed on a silicon substrate and a driver IC 5 covered with a potting resin 4, and supplying a current to each heater in accordance with image data to be transferred. Printed circuit board 6 on which wiring is formed, and driver IC 5
And a cover 7 that also serves as a protective path for the dye and a supply path for the dye.

The head base 2 has a recording liquid introduction hole 8 for introducing a recording liquid into the printer head 1,
When the heater chip 3 is adhered to the head base 2, a groove 9 is formed as an escape area for an excess adhesive that protrudes.
The inside of the cover 7 is a recording liquid supply path 10 for supplying the recording liquid to the recording liquid introduction path of the heater chip 3. The printed circuit board 6 is provided with connector terminals 11. The surface of the heater chip 3 is N for protection.
It is covered with an i-sheet 3a, and a sheet resist 3b for forming a recording liquid introduction path is formed in a line inside the i-sheet 3a. Further, the heater chip 3 has a plurality of heaters for heating and vaporizing the recording liquid, wiring for applying a signal voltage based on an image signal to each of the heaters, and supplying a current to each heater. Are formed by a lithography process.

That is, as shown in FIG. 4 (a partial enlarged view of the vaporizing portion 13 at the tip of the heater chip 3 and its vicinity), for example, with a pitch Lp = 84.7 μm and a total of 25 heaters 14
Six are formed. At this time, since one heater 14 transfers one dot, a resolution of 300 DPI can be realized.
The heater 14 is formed of polysilicon having a size of 20 μm × 20 μm. The heater 14 is connected to an aluminum individual electrode 15 and a common electrode 16 for applying a signal voltage based on an image signal and supplying current. Have been. Here, the vaporizing portions 13 are separated from each other by the partition walls 17, and a concave portion (the recording liquid storage portion 18) surrounded by the partition walls 17.
The recording liquid is stored in the storage. The diameter of the heater 14 is 2 mm on and around the heater 14 via SiO ₂ (not shown) which is a protective film.
A small columnar body 19 having a column diameter of 2 μm, a partition wall of 2 μm, and a height of 6 μm is provided as one of the constituent elements of the vaporizing section 13 in a group of 13 × 13.

The height of the small column 19 is set to the recording liquid storage portion 18.
And the height from the bottom surface to the top surface thereof, that is, the same height as the height of the partition wall 17 surrounding the recording liquid storage portion 18 of each heater 14, and each small column 19 is They are provided with a small gap between each other so as to form a porous structure. Accordingly, the porous structure causes a capillary action, and thus each of the small columns 19 can hold the recording liquid in the recording liquid storage portion 18. At the same time, the heater 14
When the recording liquid is heated in step (1), the surface tension of the recording liquid decreases as the temperature rises. However, the recording liquid can be prevented from escaping from the vicinity of the surface of the heater 14 by the capillary action. Therefore, at the time of image transfer, a necessary recording liquid is continuously supplied.

As shown in FIG. 1A, the printer head 1 comes into contact with a recording material (printing paper) 12 at only one end 2a of the base, and has a predetermined angle with respect to the recording material 12. So it is held. Thus, the distance between the vaporizing section 13 and the recording material 12 can be kept constant. For example, the center position of the heater 14 of the vaporizing section 13 (FIG. 1)
(A dashed line in (a)) is located at a distance of 1.85 mm from the head base end 2 a in contact with the recording material 12, and is formed on a 0.4 mm thick silicon substrate. The angle between the head base 2 and the recording material 12 such that the distance between the recording material 12 and the recording material 12 is 50 μm (however, the thickness of the adhesive layer between the silicon substrate and the head base 2 is 10 μm). At 14 degrees. Thus, by appropriately changing the distance from the head base end 2a to the center position of the heater and the angle between the recording material 12 and the head base 2, the heater 14 and the recording material 12 are formed.
Can be set to an arbitrary size.
Hereinafter, an application example of the recording used in the above-described printer will be specifically described.

No. 1 in Table 1. The dye No. 1 was dissolved in dibutyl phthalic acid at a concentration of 10% by weight to obtain a yellow recording liquid. When this was introduced into the ink tank from the recording liquid introduction hole of the printer head shown in FIG. 1, the recording liquid spontaneously was introduced to the vaporizing portion at the tip of the recording heater chip through the passage. Next, to the heater of the printer head,
By applying the following pulse voltage, the recording liquid was thermally transferred to photographic paper.

(Pulse voltage condition) 80 mW, 1 gradation, ON time 12 μs, OFF time 2 μs, 1 pulse, 256 pulses applied per dot. As a result of thermal transfer under the above conditions, a dot having an optical density of 1.33 was able to be formed on A6 plain paper as measured with a Macbeth reflection densitometer. When this transfer was continued, a large number of prints of 5,000 or more could be performed.

Examples 2 to 3 In place of the dyes used in Example 1, the dyes shown in Table 2 were used among the dyes shown in Table 1 above, and the melting point and the maximum absorption were obtained in the same manner as in Example 1. As shown in Table 2, the solubility was high, as shown in Table 2,
It was possible to obtain a yellow color record with a clear color density, and the number of prints was good.

Examples 4 and 5 Instead of the dyes used in Example 1, the dyes shown in Table 2 of the following Table 1 were used and dissolved in dibutylphthalic acid at a concentration of 20% by weight. As a result, a yellow recording liquid was obtained, and a transfer test was performed using this recording liquid in the same manner as in Example 1. As a result, as shown in Table 2, a yellow recording having a clear color density was obtained. And the number of prints was good.

Application Comparative Example Instead of the dye compound of Example 1, the following dye compound A,
Measurement and transfer of melting point, maximum absorption wavelength and solubility using the following dye compound B described in the examples of JP-A-8-244364 and the following dye compound C described in the examples of JP-A-63-142062. The test was performed as in the application. Table 2 shows the results.

[0030]

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[0031]

[Table 2]

[0032]

The styryl compound of the present invention is a novel yellow dye compound and has good solubility in a solvent, so that it is easy to prepare an ink. Particularly, when used for dye vaporization type thermal transfer recording, Since an ink having a high pigment concentration can be prepared, a clear yellow recorded matter having a low energy and a high density can be obtained, and the number of printed images of the recorded matter is large and good.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view (FIG. 1A) and a lower perspective view (FIG. 1B) of a printer head used in an embodiment.

FIG. 2 is a plan view of a printer head used in the embodiment.

FIG. 3 is a plan view of a printer head used in the embodiment.

FIG. 4 is a partially enlarged view of a printer head used in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printer head 2 Head base 3 Heater chip 4 Potting resin 5 Driver IC 6 Printed circuit board 7 Cover 8 Recording liquid introduction hole 9 Groove 10 Recording liquid supply path 11 Connector terminal 12 Recording material (printing paper) 13 Vaporization part 14 Heater 15 Individual electrode 16 Common electrode 17 Partition wall 18 Recording liquid storage unit 19 Column

Claims (5)

[Claims] 1. A styryl compound represented by the following general formula (I). Embedded image (However, in the general formula (I), ring A is a benzene ring which may further have a substituent, R ₁ represents an unsubstituted alkyl group having 2 to 4 carbon atoms, and R ₂ represents 5 carbon atoms. -8 represents an unsubstituted alkyl group, and R ₃ represents an unsubstituted alkyl group having 1 to 4 carbon atoms.) 2. The styryl compound according to claim 1, wherein R ₃ in the general formula (I) is a methyl group. 3. The styryl compound according to claim 1, wherein R ₂ in the general formula (I) is an unsubstituted alkyl group having 8 carbon atoms. 4. The styryl compound according to claim 1, wherein ring A in formula (I) has no further substituent. 5. A dye comprising the styryl compound according to claim 1.