JPH10265723A - Hot-melt ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain hot-melt ink having good shelf life and printing quality, capable of corresponding also to OHP sheet, excellent in transparency, adhesiveness and heat resistance, optimum to hot-melt type ink jet recording and exhibiting vivid color. SOLUTION: This ink uses C.I. solvent yellow 162 (R) as a recording agent and contains at least one kind among four kinds of components comprising (a) a resin selected from an amide resin and 5C and 9C-based synthetic petroleum resins, (b) a resin selected from a rosin resin, a terpene resin and a terpenephenol resin and (c) wax selected from paraffin wax, ketone wax and polyethylene oxide wax and (d) wax selected from monoamide wax and diamide wax and further may contain an antioxidant.

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.

However, these water-based and oil-based inks are liquid at room temperature, and when printed on recording paper, penetrate rapidly due to rapid penetration, and it is difficult to obtain sufficient print density. Furthermore, since the ink is always liquid, precipitates such as dye aggregates are likely to be generated from the ink during storage, and these deposits block the ink flow paths and ejection ports, thereby reducing the reliability of the ink jet recording system. This was a major cause of the decline.

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.
No. 12627, discloses a coloring material, a first solvent which is solid at room temperature and liquefies when heated to a temperature higher than room temperature,
An ink comprising a second solvent which is liquid at room temperature and has a high volatility in which the first solvent is dissolved;
No. 73 proposes an ink containing a synthetic wax having a polar group and a dye soluble in the wax.

[0007]

However, these conventional hot-melt inks have good printing properties such as transparency, color stability during storage, recording density and hue, which are the basic properties of the ink. There is no one that satisfies the quality satisfactorily. In particular, poor dispersibility and solubility of the dye with respect to the main component of the ink greatly affected these defects. In addition, demand has been increasing due to the recent shift to OA.
To cope with the colorization of presentation media such as OHP (overhead projector), transparency for image color reproduction at the time of projection, adhesiveness to an OHP film, and heat resistance at the time of use are required. 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.
Transparency and adhesiveness that can be used for printing on OHP sheets,
It is an object of the present invention to provide a hot-melt ink which is excellent in heat resistance and exhibits a clear color which 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. A medium containing Solvent Yellow 162 and further dissolving or dispersing the recording agent;
(B) at least one resin selected from rosin resin, terpene resin, and terpene phenol resin; (c) at least one resin selected from amide resin, C5 synthetic petroleum resin, and C9 synthetic petroleum resin It is characterized by comprising at least one component selected from the group consisting of at least one wax selected from paraffin wax, ketone wax and oxidized polyethylene wax, and (d) at least one wax selected from monoamide wax and diamide wax. .

C. I. Solvent Yellow 162 is an oil-soluble dye, and has an excellent dispersibility / solubility and coloring property with respect to the above-mentioned resin and wax as compared with other dyes, so that it produces an ideal yellow color when printed on plain paper. be able to.

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 resins ensure the adhesiveness of the ink to the printing paper, especially good adhesiveness even to different printing papers such as OHP and plain paper, and at the same time, control the viscosity of the ink during melting. Also, it acts to impart transparency to the ink by preventing crystallization of the wax. Therefore, it is an object of the present invention to provide a hot-melt ink having good printing quality, excellent transparency, 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. Can be.

[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,
Transparency and adhesiveness that can be used for printing on OHP sheets,
It is possible to provide a hot-melt ink which is excellent in heat resistance and exhibits a clear color which is optimal for hot-melt ink jet recording.

[0013]

Embodiments of the present invention will be described below.

Dye used as recording agent I. The content of the solvent yellow 162 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, 0.1% based on the total weight of the ink.
To 15% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight. Content is 1
If it is less than 5% by weight, the printing density becomes insufficient and
When the ratio exceeds the range, 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. When the content is less than 5% by weight, the effects of controlling the viscosity of the ink and imparting the transparency of the ink by inhibiting the crystallization of the wax are weakened, and in the range exceeding 30% by weight, the viscosity of the ink becomes high. This makes it impossible to discharge well from the discharge port of the inkjet head.

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".
In the case of a composition such that the sum of the parts by weight of all the components becomes 100, the numerical value of the parts by weight of each component is expressed as a weight% based on the total weight of the ink.
Is equivalent to

The inks having the compositions of Examples 1 to 6 and Comparative Examples 1 to 4 are obtained by heating and dissolving each composition at a temperature of about 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 Yellow 162 1.5 parts Sunmide 550 12 parts Clearon P115 5 parts T-1 50 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 Yellow 162 1.5 parts Versamide 335 22 parts YS Polystar T115 5 parts Wax KM 50 parts Nikka Amide S 20 parts ADK STAB 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 Yellow 162 1.5 parts Archon P115 22 parts YS Polystar T100 5 parts Stearon 52 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 Yellow 162 1.5 parts Alcon P100 22 parts YS Polystar T100 5 parts HNP-0190 45 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 Yellow 162 1.5 parts Alcon M90 20 parts YS Polystar 2115 5 parts HNP-16B 47 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 Yellow 162 1.5 parts Alcon P115 20 parts SR-30PX 5 parts Paraffin wax 155 52 parts Nikka Amide S 20 parts ADK STAB AO-37 1.5 parts.

Comparative Example 1 An antioxidant was removed from the formulation of Example 1 above. That is, the ink formulation is: I. Solvent Yellow 162 1.5 parts Sunmide 550 12 parts Clearon P115 5 parts T-1 50 parts Nikka Amide SE 31.5 parts.

Comparative Example 2 C.I. I. The composition was the same as that of Example 2 except that Solvent Yellow 163 was used. That is, the ink formulation is: I. Solvent Yellow 163 1.5 parts Versamide 335 22 parts YS Polystar T115 5 parts Wax KM 50 parts Nikka Amide S 20 parts ADK STAB AO-37 1.5 parts.

Comparative Example 3 C.I. I. The composition is the same as that of Example 3 except that Solvent Yellow 114 was used. That is, the ink formulation is: I. Solvent Yellow 114 1.5 parts Alcon P115 22 parts YS Polystar T100 5 parts Stearon 52 parts Bisamide 18 parts Sumilizer BHT 1.5 parts.

Comparative Example 4 C.I. I. The composition was the same as that of Example 4 except that Solvent Yellow 77 was used. That is, the ink formulation is: I. Solvent Yellow 77 1.5 parts Alcon P100 22 parts YS Polystar T100 5 parts HNP-0190 45 parts Nikka Amide S 25 parts Sumilizer BHT 1.5 parts.

Each of the inks of Examples 1 to 6 and Comparative Examples 1 to 3 described above was heated and liquefied in a hot-melt type ink jet recording apparatus by discharging the ink on demand 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) Printing color: 4024 paper (XEROX)
Prints on all nozzles at the same time, and prints a patch (several c).
An m-square square shape solid print) was manufactured, and the patch was applied to a multi-source spectrophotometer (MSC-5 manufactured by Suga Test Instruments Co., Ltd.).
N), and the following criteria in the L * a * b * color system ○: a * is -20 or less, b * is 70 or more Δ: a * is -15 or less, b * is 70 or more ×: a * Was -15 or less and b * was 70 or less.

(2) Storage stability: The prepared ink was 1
It was put into an oven heated to 20 ° C. and stored for 10 days. Thereafter, the sheet was mounted on the recording apparatus and 100 sheets of continuous printing were printed, and evaluated according to the following criteria: 異常: no abnormality ×: non-ejection, print disorder.

(3) Heat resistance: The sample printed in the above (2) was used as a patch, and the patch was measured using a multi-source spectrophotometer (MSC-5N manufactured by Suga Test Instruments Co., Ltd.), and L * ΔE was measured using the a * b * color system, and the following criteria were evaluated: ΔE: 5.0 or less Δ: ΔE: 7.0 or less ×: ΔE: 10.0 or more

(4) Light resistance: The patch manufactured in the above (1) was irradiated with ultraviolet rays of 17,500 lx in a weather meter (manufactured by Suga Test Instruments Co., Ltd.) and subjected to a continuous test for 72 hours. . After that, the patch was measured with a multi-source spectrophotometer (MSC-5N, manufactured by Suga Test Instruments Co., Ltd.).
ΔA was measured using the * a * b * color system, and the following criteria were evaluated: ΔE: 5.0 or less Δ: ΔE: 7.0 or less ×: ΔE: 10.0 or more

[0047]

[Table 1]

From the results shown in Table 1 above, Examples 1 to 6
It was confirmed that the ink of No. 4 exhibited almost satisfactory characteristics in all of the four evaluation items of the hue of printing color, storage stability, heat resistance and light resistance.

On the other hand, in Comparative Example 1, the antioxidant was removed from the composition of Example 1, and the heat resistance and light resistance deteriorated because the oxidation resistance deteriorated.

Comparative Examples 2 to 4 correspond to Examples 1 to 6
A different dye was used, and the color and hue were poor due to poor dispersibility and solubility in resins and waxes, and heat resistance and light resistance were also poor.

[0051]

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 Yellow 162
With good dispersibility and solubility in specific resins and waxes, it has good preservability and print quality, and has transparency that can be used for printing on OHP sheets, making it ideal for hot melt inkjet recording. A hot-melt ink exhibiting a clear color can be provided. This heat-meltable ink has good heat resistance and storage stability, and can be used not only for plain paper but also for OHP.
Printing can be performed with good adhesiveness on any recording paper such as a sheet.

The hot-melt ink according to claim 2 has good storage stability and print quality, and is excellent in transparency, adhesiveness, and heat resistance that can be used for printing on an OHP sheet. It is possible to provide a hot-melt ink that is optimal for melt-type ink jet 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 Yellow 162 and dissolving or dispersing the recording agent includes the following (a):
(B), (c) and (d), that is, (a) at least one resin selected from amide resin, C5 synthetic petroleum resin, and C9 synthetic petroleum resin, (b) rosin resin, terpene resin , At least one resin selected from terpene phenolic resins, (c) at least one type of wax selected from paraffin wax, ketone wax, and polyethylene oxide wax; (d) at least one type selected from monoamide wax and diamide wax A hot melt ink comprising at least one component selected from the group consisting of: 2. The hot-melt ink according to claim 1, wherein the medium contains an antioxidant.