JPH10292142A - Thermally meltable ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermally meltable ink good in storability and print quality, capable of dealing with the printing of OHP sheets, excellent in adhesivity and heat resistance, and exhibiting a brilliant color optimal to hot melt type ink jet recording. SOLUTION: This thermally meltable ink is used for hot melt ink jet recording devices which thermally melts the ink at higher temperature than ordinary temperature and subsequently prints the ink to record, and comprises C.I. solvent black 29 as a dye and at least one component among (a) a resin selected from amide resins and 5C.9C synthetic petroleum resins, (b) a resin selected from rosin resins, terpene resins and terpene phenolic resins, (c) a wax selected from paraffin wax, ketone waxes and polyethylene oxide wax and (d) a wax selected from monoamide waxes and diamide waxes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-melt ink used in an ink-jet recording apparatus, and more particularly to a hot-melt ink-jet recording apparatus in which recording is performed by heating and melting the ink at a temperature higher than room temperature. And heat-fusible inks.

[0002]

2. Description of the Related Art Conventionally, as an ink jet recording system, for example, a so-called electric field control system in which the flying direction of continuously ejected ink is deflected by electrostatic attraction, and a so-called electric field control system, and vibration of a piezo element are used. A method called a drop-on-demand method (pressure pulse method) in which ink is ejected by controlling the pressure applied to an ink chamber by pressure, and bubbles are formed and grown by locally heating the ink in a capillary to generate ink. Various methods, such as a so-called thermal ink-jet method, for ejecting ink by using an ink jet printer have been proposed, and these can output an extremely high-definition image.

[0003] As inks used in these ink jet recording systems, aqueous inks using water as a main solvent and oil-based inks using an organic solvent as a main solvent are generally used. The print image using the aqueous ink is
In general, oil-based inks can provide printed images having excellent water resistance, while water resistance is poor.

[0004] However, since these aqueous and oily inks are liquid at room temperature, bleeding easily occurs when printed on recording paper. Further, since the printing density tends to decrease due to penetration into the paper, it was difficult to obtain a sufficient recording density. Furthermore, since the ink is always liquid, it is easy for precipitates to be generated from the ink, and these precipitates greatly reduce the reliability of the ink jet recording method, such as blocking the ink flow path and the discharge port of the ink jet recording head. Had the disadvantage of causing the

In order to improve the disadvantages of these conventional solution type inks, a so-called hot melt type ink jet recording system using an ink which is solid at normal temperature and melts by heating has been proposed. Various types of hot-melt inks for use in this type of ink jet recording system have been proposed.

For example, US Pat. No. 3,653,932 discloses an ink containing a dialkyl sebacate, US Pat. No. 4,390,369 and JP-A-58-108271 disclose an ink containing a natural wax. JP-A-59-22973 discloses an ink containing stearic acid.
JP-A-83268 discloses an ink containing an acid or alcohol having 20 to 24 carbon atoms and further containing a ketone having a relatively high melting point.
No. 8774 discloses an ink containing a thermosetting resin having a high hydroxyl value, a solid organic solvent having a melting point lower than 150 ° C., and a small amount of a dye substance.
In Japanese Patent Publication No. 112627, a coloring material, a first solvent which is solid at room temperature and liquefies when heated to a temperature higher than room temperature, and a second solvent which is liquid and highly volatile at room temperature and dissolves the first solvent. Solvent and ink, JP-A-62-29
No. 5973 proposes a synthetic wax having a polar group, an ink containing a dye soluble in the wax, and the like.

[0007]

However, these conventional hot-melt inks have sufficient basic printing properties such as color stability during storage of the ink and good print quality such as recording density and hue. In particular, poor dispersibility and solubility of the dye in the main component of the ink greatly affected these drawbacks. In addition, the demand for OHP has been increasing due to the recent shift to OA.
In order to cope with colorization of presentation media such as (overhead projector), adhesiveness to OHP film and heat resistance during use are necessary.
There was no hot-melt ink that could satisfy all of these conditions.

The present invention has been made to solve the above-mentioned problems, and has excellent storage stability and printing quality.
It is an object of the present invention to provide a hot-melt ink having excellent adhesiveness and heat resistance that can be used for printing on an OHP sheet, and exhibiting a clear color that is optimal for hot-melt ink jet recording.

[0009]

Means for Solving the Problems To achieve this object, the heat-fusible ink according to claim 1 of the present invention comprises C.I. I. The medium containing Solvent Black 29 and further dissolving or dispersing the recording agent is (a) an amide resin, a C5 synthetic petroleum resin, a C9 synthetic petroleum resin,
At least one resin selected from the group consisting of: (b) at least one resin selected from a rosin resin, a terpene resin, and a terpene phenol resin; (c) a paraffin wax;
It is characterized by comprising at least one component of at least one wax selected from ketone wax and oxidized polyethylene wax, and (d) at least one wax selected from monoamide wax and diamide wax.

C. I. Solvent Black 29 is an oil-soluble dye, which is dispersed and dispersed in the resin and wax.
Because solubility and coloring properties are superior to other dyes,
When printed on plain paper, an ideal black color can be developed.

The above-mentioned waxes are used for dispersing a dye.
In addition to dissolving, the physical properties of the ink, such as thermal properties and viscosity, are determined. The above-mentioned resins ensure the adhesiveness of the ink to the printing paper, especially good adhesiveness to different printing papers such as OHP and plain paper, and at the same time, control the viscosity of the ink at the time of melting. Works.
Therefore, it is possible to provide a hot-melt ink which has good print quality, excellent adhesiveness for printing on an OHP sheet, and excellent heat resistance, and is suitable for hot-melt ink jet recording and exhibits a clear color.

[0012] The heat fusible ink according to claim 2 is characterized in that the medium for melting or dispersing the recording agent contains an antioxidant. The antioxidant is intended to prevent oxidation of the ink during use at high temperatures or during long-term storage, thereby preventing discoloration and fading of the ink and the recorded matter due to the ink, and ensuring good storability and print quality. . Therefore, storage stability and print quality are good,
It is possible to provide a hot-melt ink which is excellent in adhesiveness and heat resistance which can be used for printing on an OHP sheet, and which is optimal for hot-melt ink jet recording and which exhibits a clear color.

[0013]

Embodiments of the present invention will be described below.

Dye used as recording agent I. The content of the solvent black 29 is determined depending on the type of a resin or wax as a solvent component for dispersing and dissolving the recording agent, the characteristics required for the ink such as color tone and image density, and the like. Generally, it is in the range of 0.1 to 15% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight based on the total weight of the ink. When the content is less than 1% by weight, the print density becomes insufficient, and when the content exceeds 5% by weight, the degree of freedom in selecting the solvent component tends to be narrow.

As the recording agent, in addition to using the dye alone, the dye and another oil-soluble dye may be used in combination.

Next, the solvent component containing the dye as a solute will be described.

Amide resin, C5 synthetic petroleum resin, and C
At least one resin selected from the ninth synthetic petroleum resins generally has a content of 1 to 35% by weight, more preferably 5 to 30% by weight, based on the total weight of the ink. If the content is less than 5% by weight, the effect of controlling the viscosity of the ink will be weak, and if it exceeds 30% by weight, the viscosity of the ink will be too high and the ink will be ejected well from the ejection opening of the inkjet head. You will not be able to do it.

At least one resin selected from a rosin resin, a terpene resin, and a terpene phenol resin generally has a content of 0.1 to 15% by weight based on the total weight of the ink, and more preferably. It is 0.5 to 10% by weight. When the content is less than 0.5% by weight, the effect of enhancing the adhesiveness to printing paper is weak, and when the content is more than 10% by weight, the tackiness of the ink after printing becomes too large. When the ink is superimposed on the other printing paper, the ink may be transferred to another superposed paper.

At least one kind of wax selected from paraffin wax, ketone wax and fatty acid amide wax is generally used in an amount of 1 to 70% based on the total weight of the ink.
%, More preferably 10 to 60% by weight. When the content is less than 10% by weight, the wax component decreases and the resin component increases, so that the range of the melting temperature of the ink is widened. The solidification speed at the time becomes slow, causing a problem that the ink on the printed paper is transferred to another paper. When the content is less than 10% by weight, the viscosity of the ink becomes too high,
It becomes impossible to discharge well from the discharge port of the inkjet head. If the content exceeds 60% by weight,
If the viscosity of the ink becomes too low, problems such as bleeding of the ink on the paper occur, and good printing cannot be performed.

At least one wax selected from monoamide waxes and diamide waxes generally has a content of 0.5 to 40% by weight, more preferably 5 to 30% by weight, based on the total weight of the ink. It is. If the content is less than 5% by weight, the dispersibility and solubility of the dye will be poor. If the amount exceeds 30% by weight, an unpleasant odor is generated in the ink, the melting point of the ink is increased, and the amount of heat for melting the ink is increased, so that the power consumption of the inkjet head is increased. Further, since the amine value increases, heat resistance, light resistance, and oxidation resistance deteriorate.

The content of the antioxidant is generally from 0.1 to 5% by weight, more preferably from 0.5 to 3% by weight, based on the total weight of the ink. If the content is less than 0.5% by weight, the antioxidant effect of the ink, that is, the effect of preventing discoloration, is insufficient. If the content is more than 3% by weight, the thermal properties of the ink are greatly changed due to the high melting point. In addition, the color of the ink after printing deteriorates because excessive antioxidant is deposited on the surface of the ink after printing as if blowing white powder.

The hot-melt ink of the present embodiment comprising the above five components as essential components includes not only plain paper but also O
It has a high print density on HP paper, provides clear and high-quality prints, and has excellent properties of light resistance and high-temperature storage stability. It is also possible to add additives such as a plasticizer and a surfactant.

Hereinafter, more preferable examples of the heat-fusible ink (hereinafter, simply referred to as ink) according to the embodiment of the present invention will be described in more detail by comparing with a comparative example.

[0024]

EXAMPLES In the following description of Examples and Comparative Examples, "parts" all mean "parts by weight".
Since the sum of the parts by weight of the full prime is described as 100, the numerical value of the parts by weight of each component is equivalent to the weight% based on the total weight of the ink.

The inks having the compositions of Examples 1 to 6 and Comparative Examples 1 to 3 described below are obtained by heating and dissolving each composition at a temperature of 70 to 250 ° C., preferably about 100 to 200 ° C. The actual dissolution temperatures in the examples and comparative examples are slightly different depending on each composition), and after sufficient stirring, filtration is performed using a 2 μm mesh filter with a heating filtration device manufactured by Toyo Roshi Kaisha Co., Ltd. It can be obtained by:

Example 1 Sunmide 550 (manufactured by Sanwa Chemical Industry Co., Ltd.) as an amide resin, Clearon P115 (manufactured by Yashara Chemical Co., Ltd.) as a terpene resin, and T-1 (Kao Kao) as a ketone wax Nikka Amide SE as monoamide wax
(Manufactured by Nippon Kasei Kogyo Co., Ltd.), and an antioxidant is Irganox 1010 (manufactured by Ciba Geigy).

The ink formulation is as follows: I. Solvent Black 29 3.5 parts Sunmide 550 12 parts Clearon P115 5 parts T-148 parts Nikka Amide SE 30 parts Irganox 1010 1.5 parts.

Example 2 Versamide 335 (manufactured by Henkel Hakusui Co., Ltd.) as an amide resin, YS Polystar T115 (manufactured by Yashara Chemical Co., Ltd.) as a terpene resin, and wax KM as a ketone wax
(Manufactured by Nippon Kasei Kogyo Co., Ltd.), Nikka Amide S (manufactured by Nippon Kasei Kogyo Co., Ltd.) as the monoamide wax, and ADK STAB AO-37 (manufactured by Asahi Denka Kogyo Co., Ltd.) as the antioxidant. .

The ink formulation is as follows: I. Solvent Black 29 3.5 parts Versamide 335 22 parts YS Polystar T115 5 parts Wax KM 48 parts Nikka Amide S 20 parts Adekastab AO-37 1.5 parts.

Example 3 Alcon P115 (manufactured by Arakawa Chemical Industries, Ltd.) as a hydrocarbon resin, YS Polystar T100 (manufactured by Yashara Chemical Co., Ltd.) as a terpene resin, and stearone (Kanto) as a ketone wax Bisamide wax is a bisamide (Nippon Kasei Kogyo Co., Ltd.) and the antioxidant is Sumilizer BHT (Sumitomo Chemical Co., Ltd.).

The ink formulation is as follows: I. Solvent Black 29 3.5 parts Alcon P115 22 parts YS Polystar T100 5 parts Stearon 50 parts Bisamide 18 parts Sumilizer BHT 1.5 parts.

Example 4 Alcon P100 (manufactured by Arakawa Chemical Industries, Ltd.) as a hydrocarbon resin, YS Polystar T100 (manufactured by Yashara Chemical Co., Ltd.) as a terpene resin, and HNP-0 as a paraffin wax
190 (manufactured by Nippon Seiro Co., Ltd.), as monoamide waxes, Nikka Amide S (manufactured by Nippon Kasei Kogyo Co., Ltd.),
The antioxidant is Sumilizer BHT (manufactured by Sumitomo Chemical Co., Ltd.).

The ink formulation is as follows: I. Solvent Black 29 3.5 parts Alcon P100 22 parts YS Polystar T100 5 parts HNP-0190 43 parts Nikka Amide S 25 parts Sumilizer BHT 1.5 parts.

Example 5 Alcon M90 (manufactured by Arakawa Chemical Industries, Ltd.) as a hydrocarbon resin, YS Polystar 2115 (manufactured by Yashara Chemical Co., Ltd.) as a terpene resin, and HNP-1 as a paraffin wax
6B (manufactured by Nippon Seiro Co., Ltd.), Nikka Amide S (manufactured by Nippon Kasei Kogyo Co., Ltd.) as a monoamide wax, and ADK STAB AO-37 (manufactured by Asahi Denka Kogyo Co., Ltd.) as an antioxidant. is there.

The ink formulation is as follows: I. Solvent Black 29 3.5 parts Alcon M90 20 parts YS Polystar 2115 5 parts HNP-16B 45 parts Nikka Amide S 25 parts Adekastab AO-37 1.5 parts.

Example 6 Alcon P115 (manufactured by Arakawa Chemical Industry Co., Ltd.) as a hydrocarbon resin, SR-30PX (Arakawa Chemical Industry Co., Ltd.) as a terpene resin, and paraffin as paraffin wax Wax 155 (manufactured by Nippon Seiro Co., Ltd.), as monoamide wax, Nikka Amide S (manufactured by Nippon Kasei Kogyo Co., Ltd.),
As the antioxidant, ADK STAB AO-37 (manufactured by Asahi Denka Kogyo KK) is used.

The ink formulation is as follows: I. Solvent Black 29 3.5 parts Alcon P115 20 parts SR-30PX 5 parts Paraffin wax 155 50 parts Nikka Amide S 20 parts Adekastab AO-37 1.5 parts.

Comparative Example 1 Sunmide 550 (manufactured by Sanwa Chemical Industry Co., Ltd.) as an amide resin, Clearon P115 (manufactured by Yashara Chemical Co., Ltd.) as a terpene resin, and T-1 (Kao Kao) as a ketone wax Nikka Amide SE as monoamide wax
(Nippon Kasei Kogyo Co., Ltd.).

The ink formulation is as follows: I. Solvent Black 29 3.5 parts Sunmide 550 12 parts Clearon P115 5 parts T-148 parts Nikka Amide SE 31.5 parts.

Comparative Example 2 The dye was C.I. I. Solvent Black 3, Versamide 335 (manufactured by Henkel Hakusui Co., Ltd.) as an amide resin, YS Polystar T115 (manufactured by Yasuhara Chemical Co., Ltd.) as a terpene resin, and Wax KM (Nippon Kasei Kogyo Co., Ltd.) as a ketone wax
Nikka Amide S as monoamide wax
(Manufactured by Nippon Kasei Kogyo Co., Ltd.), and the antioxidant is ADK STAB AO-37 (manufactured by Asahi Denka Kogyo Co., Ltd.).

The ink formulation is as follows: I. Solvent Black 3 3.5 parts Versamide 335 22 parts YS Polystar T115 5 parts Wax KM 48 parts Nikka Amide S 20 parts Adekastab AO-37 1.5 parts.

<Comparative Example 3> C.I. I. Solvent Black 27, Alcon P as hydrocarbon resin
115 (manufactured by Arakawa Chemical Industry Co., Ltd.), and as terpene resin, YS Polystar T100 (Yasuhara Chemical Co., Ltd.)
), Ketone wax as stearone (Kanto Chemical Co., Ltd.), bisamide as bisamide (Nippon Kasei Kogyo Co., Ltd.), and antioxidant as Sumilizer BHT (Sumitomo Chemical Co., Ltd.). ).

The ink formulation is as follows: I. Solvent Black 27 3.5 parts Alcon P115 22 parts YS Polystar T100 5 parts Stearon 50 parts Bisamide 18 parts Sumilizer BHT 1.5 parts.

Each of the inks of Examples 1 to 6 and Comparative Examples 1 to 3 described above was ejected on demand from a hot-melt ink jet recording apparatus (an ink heated and liquefied in the apparatus by a recording head). Table 1 shows the evaluation results of the printing color, storage stability, heat resistance, and light resistance when printing was performed by mounting the ink on a recording paper (a type of ink jet recording apparatus that attaches droplets to recording paper). The evaluation method and conditions for each item are as follows.

(1) Print density: 4024 paper (XERO)
X (manufactured by Company X) and simultaneously print all nozzles to produce a patch (solid print of a square shape of several cm square), and measure the patch with a densitometer (RD914 manufactured by Macbeth Co., Ltd.). The values were evaluated according to the following criteria: ：: OD value of 1.2 or more Δ: OD value of less than 1.2 ×: Unprintable (no dye dissolved)

(2) Storage stability: The prepared ink was used for 1
It was put into an oven heated to 20 ° C. and stored for 10 days. After that, it is mounted on the recording device and mounted on 4024 paper (XE
ROX Co., Ltd.) and continuous printing was performed on 100 sheets, and evaluated according to the following criteria.

(3) Viscosity change: The sample heat-preserved in the above (2) was subjected to a viscometer (Brookfield Corp.
LVDV-2 +), and compared with those in the initial state, and evaluated according to the following criteria: ○: difference of 3.0 or less Δ: difference of 5.0 or less ×: difference of 10.0 or more

(4) Heat resistance: The sample printed in the above (2) is used as a patch, and the patch is measured with a multi-source spectrophotometer (MSC-5N manufactured by Suga Test Instruments Co., Ltd.), and L * Δ in comparison with the initial state in the a * b * color system
E was measured, and the following criteria were evaluated: ΔE: 3.0 or less Δ: ΔE: 5.0 or less ×: ΔE: 10.0 or more

[0049]

[Table 1]

From the results shown in Table 1 above, Examples 1 to 6
It was confirmed that the ink showed almost satisfactory characteristics in all four evaluation items of print density, storage stability, viscosity change, and heat resistance.

On the other hand, Comparative Example 1 has substantially the same composition as Examples 1 to 6, but does not contain an antioxidant. Therefore, as described above, the change in viscosity was large, and the heat resistance was deteriorated.

Further, Comparative Examples 2 and 3 are Examples 1 to 6
Since a dye different from the above was used, the dispersibility and solubility in resins and waxes were poor, so that all the evaluation items such as print density and storage stability were poor.

[0053]

As is apparent from the above description, according to the heat fusible ink of the first aspect of the present invention, C.I. I. Solvent Black 29
By providing good dispersibility and solubility in specific resins and waxes, it is possible to provide a hot-melt ink which has excellent storage stability and printing quality, and is optimal for hot-melt ink jet recording and exhibits a clear color. . This hot-melt ink is
Good heat resistance and storage stability, not only plain paper but also OH
Printing can be performed with good adhesiveness on any recording paper such as a P sheet.

The hot-melt ink according to the second aspect has good storage stability and print quality, excellent adhesiveness for printing on an OHP sheet, and excellent heat resistance. It is possible to provide a hot-melt ink which is optimal for recording and exhibits a clear color.

Claims (2)

[Claims] 1. A hot-melt ink used in a hot-melt ink jet recording apparatus in which recording is performed by heating and melting the ink at a temperature higher than room temperature, wherein C.I. I. A medium containing Solvent Black 29 and dissolving or dispersing the recording agent includes the following (a), (b),
(C) and (d), that is, (a) at least one resin selected from the group consisting of amide resin, C5 synthetic petroleum resin, and C9 synthetic petroleum resin, (b) rosin resin, terpene resin, terpene At least one resin selected from the group consisting of phenolic resins, (c) at least one wax selected from paraffin wax, ketone wax, and oxidized polyethylene wax; (d) monoamide wax and diamide wax. A heat-fusible ink comprising at least one component selected from the group consisting of at least one wax selected from the group consisting of: 2. The hot-melt ink according to claim 1, wherein the medium contains an antioxidant.