JP2001098196A - Thermally meltable ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermally meltable ink which is used for hot melt type ink jet recording, has an extremely high performance, and gives brilliant images. SOLUTION: This thermally meltable ink comprises a wax solid at the ordinary temperature, a plasticizer, a coloring material, and an antioxidant. The plasticizer is a siloxane bond-having silicone compound, concretely including alkyl-modified silicone oils, higher fatty acid ester-modified silicone oils, methylstyryl-modified silicone oils, alkylaralkylpolyether-modified silicone oils, and tetraoctyl pyromellitate. The compounds are used singly or at a mixture of two or more compounds especially without being not limited. Thereby, the ink has high heat resistance, is scarcely deteriorated even when stored at a high temperature for long time, is not sticky, does not ooze, and strongly adheres to recording paper to form ink images.

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 for use in an ink-jet recording apparatus, and more particularly, to a hot-melt ink-jet method in which recording is performed by heating and melting the ink at a temperature higher than room temperature. The present invention relates to the modification of a hot-melt ink used in a recording apparatus.

[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 ink is ejected by using electrostatic attraction; a so-called drop-on system in which ink is ejected by using a vibration pressure of a piezoelectric element. Demand method (pressure pulse method); various methods such as a so-called thermal ink jet method have been proposed in which ink is ejected using pressure generated by forming and growing bubbles by high heat. Can be obtained.

[0003] In these ink jet recording systems, a water-based ink using water as a main solvent and a solution type ink of a liquid oil ink at room temperature using an organic solvent as a main solvent are generally used. Printed images using water-based inks generally have poor water resistance, whereas oil-based inks can provide printed images having excellent water resistance. However, since these solution-type aqueous inks and oil-based inks are liquids at room temperature, when printed on recording paper, bleeding is likely to occur, and a sufficient print density cannot be obtained. This is liable to cause the generation of precipitates from the ink jet recording, which causes the reliability of the ink jet recording system to be greatly reduced.

For the purpose of remedying the drawbacks of these conventional solution-type inks, so-called hot-melt type oil-based inks for ink-jet type recording apparatuses, which are solid at ordinary temperature and are heated and melted when used, are used. Proposed. Specifically, JP-A-01-242672 discloses an ink containing a phthalate compound, JP-A-02-51570 discloses an ink containing a polyol benzoate, and JP-A-05-3.
JP 39528 proposes an ink containing a phthalic acid diester.

[0005]

However, these heat-meltable inks have low wettability on recording paper, especially coated paper (particularly water-based ink-jet coated paper) which has been subjected to a surface coating treatment for preventing bleeding, and therefore, printing is difficult. In such a case, there is a problem that a sufficient adhesion force cannot be obtained and the printed image is easily peeled off from the recording paper surface. In addition, if the plasticizer is left for a very long time at a high temperature, the plasticizer is deteriorated, and it is not possible to obtain sufficient flexibility, so that the adhesive force is reduced. Greatly increases, furthermore, discoloration of the ink occurs (in particular, the discoloration of the ink is remarkable for sulfonamide and pyroxybenzoate), and the compatibility with the ink vehicle decreases, resulting in separation. In addition, the plasticizer migrates from the inside of the ink to the surface, causing stickiness, and various causes such as blurring when the plasticizer dissolves the dye and the ink migrates to the surface of the recording paper. There were also problems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has significantly improved the storability in a high-temperature environment, suppressed the change in the viscosity of the ink, and suppressed the discoloration of the ink. It can significantly improve compatibility, reduce stickiness, reduce bleeding, and significantly reduce the surface tension in the molten state, making it possible to form a strong print image even on water-based inkjet coated paper, An object of the present invention is to provide a heat-meltable ink having heat resistance.

[0007]

In order to achieve this object, the hot-melt ink of the present invention is solid at room temperature, and has a low melting point.
It is characterized by containing a wax that is a main component of an ink vehicle having a melting point of from 150C to 150C, a coloring material, and a plasticizer. In particular, the plasticizer is selected from room temperature liquid alkyl-modified silicone oil, higher fatty acid ester-modified silicone oil, methylstyryl-modified silicone oil, alkylaralkyl polyether-modified silicone oil or tetraoctyl pyromellitic acid, which is compatible with the ink vehicle. And at least one of them. Here, the normal temperature refers to a temperature of a general working environment of about 10 ° C. to 35 ° C.

[0008] In the hot-melt ink of the present invention having the above-described structure, the wax is a main component of the ink and determines the properties of the ink such as thermal properties and viscosity. The coloring material gives a color to the ink composition.

[0009] In addition to these compositions, as a plasticizer, an alkyl-modified silicone oil, a silicone compound having a siloxane bond, a higher fatty acid ester-modified silicone oil, a methylstyryl-modified silicone oil, and an alkylaralkyl polyether-modified silicone oil are used as inks. When added, the surface tension is remarkably reduced due to its surface activity. Therefore, while improving the wettability of the ink on the recording paper surface, the ink droplet is imparted with appropriate softness, and a printed image which is firmly adhered even when printing on coated paper (especially water-based inkjet-only coated paper) is formed. I do.

[0010] In addition, since silicone oil has a higher heat resistance than a compound conventionally added as a plasticizer of a heat-meltable ink, an ink containing a silicone oil as a plasticizer has an extremely high heat resistance. Is provided. In addition, if the modified silicone oil is used, the compatibility with the ink vehicle will be very good, and the flash point will be high, so that it will be safe. Then, the dye solubility is lowered, and even if the ink is transferred to the surface of the fibrous recording paper in which the ink easily penetrates, bleeding due to the spread of the dye dissolved in the plasticizer does not occur.

Further, by adding tetraoctyl pyromellitic acid ester having a higher molecular weight than the ordinary plasticizer (such as phthalate ester) as a plasticizer to these compositions, the heat resistance becomes good and the material is deteriorated or evaporated. Therefore, the ink viscosity is stable and the discoloration of the ink is suppressed. Therefore, even when printing on coated paper (especially coated paper dedicated to water-based ink jet), a printed image that is firmly attached is formed.

Since the ratio of the hydrocarbon chains is higher than that of a normal plasticizer (phthalate ester or the like), the compatibility with the ink vehicle is high, and the ink does not separate even when left at a high temperature. In addition, since the molecular structure is more complicated and there are many branches compared to ordinary plasticizers (such as phthalic acid esters), the ink image formed on the recording paper has a low transferability to the surface by being separated in the ink. It is possible to prevent stickiness on the surface of the image and bleeding on the recording paper surface. In addition, as in the case where the silicone compound is added, the flash point is increased and the composition becomes safe.

[0013]

EXAMPLES Examples of the hot-melt ink of the present invention will be described below.

The hot-melt ink embodying the present invention has 50
Wax having a melting point of 30.0-90.0 ° C.
5.0%, a plasticizer is 1.0 to 30.0% by weight, desirably 1.0 to 20.0% by weight, and a dye as a coloring material is 0.1 to 10.0% by weight, desirably. The ink composition contains 0.5 to 5.0% by weight and 0.1 to 0.5% by weight of an antioxidant.

A wax having a melting point of 50 ° C. to 150 ° C., a so-called room temperature solid wax, which is used as a component of the ink vehicle, is heated at least at the ink discharge temperature of a recording apparatus having an ink jet recording head in a heated and molten state at or above the melting point. Use a stable one.

Examples of the wax include petroleum wax, preferably paraffin wax or microcrystalline wax; vegetable wax, preferably candelilla wax, carnauba wax, rice wax, or jojoba solid wax; animal wax; Preferably beeswax, lanolin or spermaceti; mineral waxes, preferably montan wax; synthetic hydrocarbons, preferably Fischer-Tropsch wax or polyethylene wax; hydrogenated waxes, preferably hydrogenated castor oil or hydrogenated castor oil derivatives; Modified waxes, preferably montan wax derivatives, paraffin wax derivatives, microcrystalline wax derivatives or polyethylene wax derivatives; higher fatty acids, preferably behenic acid, Aric acid, palmitic acid, myristic acid, or lauric acid; higher alcohol, preferably stearyl alcohol, or behenyl alcohol; hydroxystearic acid, preferably 12-hydroxystearic acid or 12-hydroxystearic acid derivative; ketone, preferably Fatty acid amides, preferably lauric acid amide, stearic acid amide, oleic acid amide, erucic acid amide, ricinoleic acid amide, 12-hydroxystearic acid amide, special fatty acid amide or N-substituted fatty acid amide or amine; Preferably dodecylamine, tetradecylamine or octadecylamine; esters;
Preferably, methyl stearate, octadecyl stearate, glycerin fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, ethylene glycol fatty acid ester, or polyoxyethylene fatty acid ester; and a polymerized wax, preferably an α-olefin maleic anhydride copolymer Any conventionally known wax such as wax can be used without any particular limitation. These waxes may be used alone or as a mixture of two or more, and may be used in an amount of 30.0 to 95.0% by weight, preferably 30.
It is contained in the range of 0 to 90.0% by weight.

The plasticizer used together with the wax reduces the surface tension of the ink to increase the wettability of the ink on the surface of the recording paper, thereby firmly attaching a printed image, and lowering the solubility of the dye. Even when transferred to the surface of the recording paper, bleeding due to spreading of the dye dissolved in the plasticizer does not occur. Further, heat resistance is improved by a silicone compound having high heat resistance. By improving the compatibility with the wax, transfer of the plasticizer to the ink surface is prevented, and stickiness is reduced. And it can be made safe by increasing the flash point.

The plasticizer is a silicone compound having a siloxane bond. Specifically, alkyl-modified silicone oil (manufactured by Shin-Etsu Chemical) higher fatty acid ester-modified silicone oil (manufactured by Shin-Etsu Chemical) methylstyryl-modified silicone oil (manufactured by Shin-Etsu Chemical) Alkyl aralkyl polyether-modified silicone oil (manufactured by Dow Corning Silicone Toray), tetraoctyl pyromellitic acid (manufactured by Asahi Denka Kogyo), and the like.

Any of these plasticizers can be used without any particular limitation, and may be used alone or
Two or more kinds may be used as a mixture, and as a whole ink
1.0 to 30.0% by weight, preferably 1.0 to 20.0%
It is contained in the range of weight%.

As the coloring material used in the ink of the present embodiment, any pigment or dye conventionally used in oil-based ink compositions can be used.

As the pigment, those generally used in the technical field of printing can be used irrespective of inorganic pigments and organic pigments. Specifically, for example, carbon black, cadmium red, molybdenum red, chrome yellow, cadmium yellow, titanium yellow, chromium oxide, viridian, titanium cobalt green, ultramarine blue, Prussian blue, cobalt blue, azo pigments, phthalocyanine-based Pigments, quinacridone pigments, isoindolinone pigments, dioxazine pigments, sulene pigments, perylene pigments, perinone pigments, thioindigo pigments, quinophthalone pigments, known pigments such as metal complex pigments without particular limitation Can be used.

As the dye, azo dye, disazo dye,
Metal complex dyes, naphthol dyes, anthraquinone dyes,
Indigo dye, carbonium dye, quinone imine dye,
Cyanine dye, quinoline dye, nitro dye, nitroso dye, benzoquinone dye, naphthoquinone dye, xanthene dye, phthalocyanine dye, metal phthalocyanine dye,
And the like.

These pigments and dyes may be used alone or in an appropriate combination, but may be used in an amount of 0.1 to 10.0% by weight, preferably 0.5% by weight based on the whole ink. To 10.0% by weight, more preferably 0.1% by weight.
It is contained in the range of 5 to 5.0% by weight.

Next, an embodiment for realizing the hot-melt ink of this embodiment will be described below.

<Example 1> A room temperature solid wax as a vehicle in Example 1 was a paraffin wax (HNP-
12, Nippon Seisaku) and stearic acid amide (Amide
S, manufactured by Kao Corporation) and montanic acid ester wax (Hoechst Wax E, manufactured by Hoechst). The plasticizer is an alkyl-modified silicone oil (KF-414, manufactured by Shin-Etsu Chemical Co., Ltd.). (CI) SO
LVENT BLACK 3 (Oil Black HBB, manufactured by Orient). Antioxidant for preventing oxidation (Irganox 1010, manufactured by Ciba Specialty Chemicals)
Is added.

The composition of the hot-melt ink used in Example 1 is as shown below.

Paraffin wax (HNP-12, manufactured by Nippon Seisaku) 40.0% by weight Amide stearate (Amide S, manufactured by Kao) 42.9% by weight Montanate ester wax (Hoechst wax E, manufactured by Hoechst) 10.0 Weight% Alkyl-modified silicone oil (KF-414, manufactured by Shin-Etsu Chemical) 5.0% by weight Antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) 0.1% by weight Colorant (SOLVENT BLACK 3 (Oil Black HBB) , Manufactured by Orient) 2.0% by weight The hot-melt ink can be prepared by the procedure shown in FIG.

First, as shown in FIG. 1A, paraffin wax (1), stearic acid amide (2), montanic acid ester wax (3), alkyl-modified silicone oil (KF-414, manufactured by Shin-Etsu Chemical) ( 4) at 70 ° C. to 2
The mixture is heated and dissolved at a temperature of 50 ° C., preferably about 100 ° C. to 200 ° C., and as shown in FIG. 1B, SOLVENT BLACK 3 (6) is mixed as a colorant with this mixture. Next, as shown in FIG. 1 (C), an antioxidant (5) is added, and a dissolver (21) is used for 200 to 10000 r.
pm, preferably 500-5000 rpm. The composition (11) mixed and stirred is shown in FIG.
As shown in (D), filtration is performed using a 2 μm mesh filter (22) with a hot filtration device manufactured by Toyo Roshi Kaisha to obtain a final hot-melt ink (12).

The prepared hot melt ink was heated at 130 ° C.
When stored in an environment for 10 days, the viscosity reduction rate was 1.0 (%) and the weight reduction rate was 2.0 (%).
The surface tension in an environment of 120 ° C. is 19.1.
(MN / m).

The prepared hot-melt ink was applied to coated paper, film, and aluminum, and the adhesiveness was confirmed by the presence or absence of peeling when bent at 180 degrees. However, no peeling was observed in any of the coated paper, film, and aluminum. Excellent adhesiveness was confirmed.

Printed matter obtained by printing the prepared hot-melt ink on plain paper was stored at 50 ° C. for 48 hours in an environment, and the printed matter before and after storage was compared to confirm the high-temperature preservability of the printed matter. However, no difference was confirmed in the printed matter before and after storage, and good printed matter high-temperature storability was confirmed.

The printed matter obtained by printing the prepared hot-melt ink on plain paper is superimposed on plain paper, and the printing is performed at 60 ° C. and 50%
It was left for 24 hours under a load of 2 kg under an RH environment, and the blocking resistance was confirmed by inspecting whether or not set-off was performed. However, set-off to plain paper was not confirmed, and good blocking resistance was confirmed. Was confirmed.

Example 2 The room temperature solid wax as an ink vehicle in Example 2 was paraffin wax (HNP-12, manufactured by Nippon Seisaku), stearic acid amide (Amide S, manufactured by Kao) and montanic acid ester wax ( Hoechst Wax E, manufactured by Hoechst), the plasticizer is a higher fatty acid ester-modified silicone oil (X-22-715, manufactured by Shin-Etsu Chemical Co., Ltd.), and the oil-soluble dye as a coloring material is Color Index (CI) SOLVENT BLACK 3 (Oil Black HBB, manufactured by Orient). An antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) for preventing oxidation is added to this.

The composition of the hot-melt ink used in Example 2 is as shown below.

Paraffin wax (HNP-12, manufactured by Nippon Seisaku) 40.0% by weight Amide stearic acid (Amide S, manufactured by Kao) 42.9% by weight Montanate ester wax (Hoechst wax E, manufactured by Hoechst) 10.0 Weight% Higher fatty acid ester modified silicone oil (X-22-715, manufactured by Shin-Etsu Chemical) 5.0% by weight Antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) 0.1% by weight Colorant (SOLVENT BLACK 3) (Oil Black HBB, manufactured by Orient)) 2.0% by weight The above heat-fusible ink is prepared as follows, but is prepared in the same procedure as in Example 1 shown in FIGS. 1 (A) to 1 (D). The illustration is omitted (the following embodiment,
Same for the comparative example).

First, paraffin wax, stearic acid amide, montanic acid ester wax, and higher fatty acid ester-modified silicone oil are heated and dissolved at a temperature of 70 to 250 ° C., preferably about 100 to 200 ° C., and mixed. Mix SOLVENT BLACK 3 as a colorant into the liquid. Next, an antioxidant was added, and 2
00 to 10000 rpm, preferably 500 to 500
Stir and mix at 0 rpm. This stirred and mixed composition is filtered by a hot filtration device manufactured by Toyo Roshi Kaisha using a 2 μm mesh filter to obtain a final hot-melt ink.

The prepared hot-melt ink was heated at 130 ° C.
When stored in an environment for 10 days, the viscosity reduction rate was 1.0 (%) and the weight reduction rate was 2.0 (%).
The surface tension under the environment of 120 ° C. is 18.9.
(MN / m).

The prepared hot-melt ink was applied to coated paper, film, and aluminum, and adhesion was confirmed by the presence or absence of peeling when bent at 180 degrees. However, no peeling was observed in any of the coated paper, film, and aluminum. Excellent adhesiveness was confirmed.

Printed matter obtained by printing the prepared hot-melt ink on plain paper was stored in an environment of 50 ° C. for 48 hours, and the printed matter before and after storage was compared to confirm the high-temperature storage property of the printed matter. However, no difference was confirmed in the printed matter before and after storage, and good printed matter high-temperature storability was confirmed.

The printed matter obtained by printing the prepared hot-melt ink on plain paper and the plain paper were combined, and the temperature was 60 ° C., 50% RH.
The anti-blocking property was confirmed by leaving it under a load of 2 kg under an environment for 24 hours and inspecting whether or not set-off was observed. However, set-off to plain paper was not confirmed, and good anti-blocking property was obtained. confirmed.

Example 3 A room-temperature solid wax used as an ink vehicle in Example 3 was paraffin wax (HNP-12, manufactured by Nippon Seisaku) and stearic acid (Kanto Chemical).
And montanic acid ester wax (Hoechst wax E,
Hoechst), the plasticizer is methylstyryl-modified silicone oil (KF-410, manufactured by Shin-Etsu Chemical), and the oil-soluble dye as a coloring material is Color Index (CI) SOLVENT
BLACK 3 (Oil Black HBB, manufactured by Orient). An antioxidant (Irganox 1) for preventing oxidation
010, manufactured by Ciba Specialty Chemicals).

The composition of the hot-melt ink used in Example 3 is as shown below.

Paraffin wax (HNP-12, manufactured by Nippon Seisaku) 40.0% by weight Stearic acid (manufactured by Kanto Kagaku) 42.9% by weight Montanic acid ester wax (Hoechst wax E, manufactured by Hoechst) 10.0% by weight Methylstyryl-modified silicone oil (KF-410, manufactured by Shin-Etsu Chemical) 5.0% by weight Antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) 0.1% by weight Colorant (SOLVENT BLACK 3 (Oil Black HBB, Orient) The hot melt ink can be prepared by the same procedure as in Example 1.

First, paraffin wax, stearic acid, montanic acid ester wax, and methylstyryl-modified silicone oil (KF-410, manufactured by Shin-Etsu Chemical Co., Ltd.) were heated at 70 ° C.
To 250 ° C, preferably 100 ° C to 200 ° C, and heat-dissolve and mix.
Mix T BLACK 3. Next, an antioxidant is added, and the mixture is stirred and mixed with a dissolver at 200 to 10000 rpm, preferably 500 to 5000 rpm. This stirred and mixed composition was filtered using a 2 μm mesh filter by a hot filtration device manufactured by Toyo Roshi Kaisha, Ltd.
Obtain the final hot melt ink.

The prepared hot-melt ink was heated at 130 ° C.
When stored in an environment for 10 days, the viscosity reduction rate was 2.0 (%) and the weight reduction rate was 2.0 (%).
The surface tension under the environment of 120 ° C. is 23.5.
(MN / m).

The prepared hot-melt ink was applied to coated paper, film, and aluminum, and adhesion was confirmed by the presence or absence of peeling when bent at 180 degrees. However, no peeling was observed in any of the coated paper, film, and aluminum. Excellent adhesiveness was confirmed.

Printed matter obtained by printing the prepared hot-melt ink on plain paper was stored under an environment of 50 ° C. for 48 hours, and the printed matter before and after storage was compared to confirm the high-temperature preservability of the printed matter. However, no difference was confirmed in the printed matter before and after storage, and good printed matter high-temperature storability was confirmed.

The printed matter obtained by printing the prepared hot-melt ink on plain paper and the plain paper were combined, and the temperature was 60 ° C., 50% RH.
The anti-blocking property was confirmed by leaving it under a load of 2 kg under an environment for 24 hours and inspecting whether or not set-off was observed. However, set-off to plain paper was not confirmed, and good anti-blocking property was obtained. confirmed.

Example 4 The room-temperature solid wax as an ink vehicle in Example 4 was paraffin wax (HNP-12, manufactured by Nippon Seisaku) and stearic acid (Kanto Chemical).
And montanic acid ester wax (Hoechst wax E,
Hoechst), the plasticizer is an alkyl aralkyl polyether-modified silicone oil (SF-8419, manufactured by Dow Corning Toray Silicone), and the oil-soluble dye as a coloring material is Color Index (CI) SOLVENT BLACK 3
(Oil Black HBB, manufactured by Orient). An antioxidant for preventing oxidation (Irganox 101)
0, Ciba Specialty Chemicals).

The composition of the hot-melt ink used in Example 4 is as shown below.

Paraffin wax (HNP-12, manufactured by Nippon Seisaku) 40.0% by weight Stearic acid (manufactured by Kanto Kagaku) 42.9% by weight Montanic acid ester wax (Hoechst wax E, manufactured by Hoechst) 10.0% by weight Alkyl aralkyl polyether modified silicone oil (SF-8419, manufactured by Dow Corning Silicone Toray) 5.0% by weight Antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) 0.1% by weight Colorant (SOLVENT BLACK) 3 (Oil Black HBB, manufactured by Orient)) 2.0% by weight The hot-melt ink can be prepared in the same procedure as in Example 1.

First, paraffin wax, stearic acid, montanic acid ester wax, alkyl aralkyl polyether-modified silicone oil (SF-8419, Toray
Dow Corning Silicone) from 70 ° C to 250
C., preferably at a temperature of about 100 ° C. to 200 ° C., and mixed by heating. SOLVENT BLACK
Mix 3 Next, an antioxidant is added, and a dissolver is used to add 200 to 10,000 rpm, preferably 50 to 10,000 rpm.
Stir and mix at 0-5000 rpm. This stirred and mixed composition was heated to 2 μm by a hot filtration device manufactured by Toyo Roshi Kaisha.
Then, filtration is performed using a mesh filter of the formula (1) to obtain a final hot-melt ink.

The prepared hot-melt ink was heated at 130 ° C.
When stored in an environment for 10 days, the viscosity reduction rate was 1.0 (%) and the weight reduction rate was 2.0 (%).
The surface tension under an environment of 120 ° C. is 24.1.
(MN / m).

The prepared hot-melt ink was applied to coated paper, film, and aluminum, and adhesion was confirmed by the presence or absence of peeling when bent at 180 degrees. However, no peeling was observed in any of the coated paper, film, and aluminum. Excellent adhesiveness was confirmed.

Printed matter obtained by printing the prepared hot-melt ink on plain paper was stored in an environment of 50 ° C. for 48 hours, and the printed matter before and after storage was compared to confirm the high-temperature storage property of the printed matter. However, no difference was confirmed in the printed matter before and after storage, and good printed matter high-temperature storability was confirmed.

The printed matter obtained by printing the prepared hot-melt ink on plain paper and the plain paper were combined, and the temperature was 60 ° C., 50% RH.
The anti-blocking property was confirmed by leaving it under a load of 2 kg under an environment for 24 hours and inspecting whether or not set-off was observed. However, set-off to plain paper was not confirmed, and good anti-blocking property was obtained. confirmed.

Example 5 The room temperature solid wax as an ink vehicle in Example 5 was paraffin wax (HNP-12, manufactured by Nippon Seisaku) and stearic acid (Kanto Chemical).
And montanic acid ester wax (Hoechst wax E,
Hoechst), the plasticizer is tetraoctyl pyromellitic acid (UL-80, manufactured by Asahi Denka Kogyo), and the oil-soluble dye as a coloring material is Color Index (CI) SOLV
ENT BLACK 3 (Oil BlackHBB, manufactured by Orient).
An antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) for preventing oxidation is added to this.

The composition of the hot-melt ink used in Example 5 is as shown below.

Paraffin wax (HNP-12, manufactured by Nippon Seiro) 40.0% by weight Stearic acid (manufactured by Kanto Kagaku) 42.9% by weight Montanic acid ester wax (Hoechst wax E, manufactured by Hoechst) 10.0% by weight Tetraoctyl pyromellitic acid (UL-80, manufactured by Asahi Denka Kogyo) 5.0% by weight Antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) 0.1% by weight Colorant (SOLVENT BLACK 3 (Oil Black) HBB, manufactured by Orient)) 2.0% by weight The hot-melt ink can be prepared in the same procedure as in Example 1.

First, paraffin wax, montanic acid ester wax, stearic acid, and tetraoctyl pyromellitic acid ester (UL-80, manufactured by Asahi Denka Kogyo) were heated at 70 ° C.
To 250 ° C, preferably 100 ° C to 200 ° C, and heat-dissolve and mix.
Mix T BLACK 3. Next, an antioxidant is added, and the mixture is stirred and mixed with a dissolver at 200 to 10000 rpm, preferably 500 to 5000 rpm. This stirred and mixed composition was filtered using a 2 μm mesh filter by a hot filtration device manufactured by Toyo Roshi Kaisha, Ltd.
Obtain the final hot melt ink.

The prepared hot-melt ink was heated at 130 ° C.
When stored in an environment for 10 days, the viscosity reduction rate was 2.0 (%) and the weight reduction rate was 2.0 (%).
The surface tension in an environment at 120 ° C. is 27.0.
(MN / m).

The prepared hot-melt ink was applied to coated paper, film, and aluminum, and adhesion was confirmed by the presence or absence of peeling when bent at 180 degrees. However, no peeling was observed in any of the coated paper, film, and aluminum. Excellent adhesiveness was confirmed.

Printed matter obtained by printing the prepared hot-melt ink on plain paper was stored in an environment of 50 ° C. for 48 hours, and the printed matter before and after storage was compared to confirm the high-temperature storage property of the printed matter. However, no difference was confirmed in the printed matter before and after storage, and good printed matter high-temperature storability was confirmed.

The printed matter obtained by printing the prepared hot-melt ink on plain paper and the plain paper are combined, and the temperature is 60 ° C., 50% RH.
It was left for 24 hours under a load of 2 kg under an environment and inspected for set-off. The anti-blocking property was confirmed. However, set-off to plain paper was not confirmed, and good blocking resistance was confirmed. Was done.

Comparative Example 1 The composition of the hot-melt ink in Comparative Example 1 is as shown below.

Paraffin wax (HNP-12, manufactured by Nippon Seisaku) 40.0% by weight amide stearic acid (Amide S, manufactured by Kao) 42.9% by weight montanic acid ester wax (Hoechst wax E, manufactured by Hoechst) 10.0 Weight% Antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) 0.1% by weight Colorant (SOLVENT BLACK 3 (Oil Black HBB, manufactured by Orient)) 2.0% by weight Thermal fusibility of Comparative Example 1 above The ink can be prepared by the following method.

First, paraffin wax, stearic acid amide and montanic acid ester wax were added at 70 ° C. to 2 ° C.
Heat and melt at a temperature of 50 ° C., preferably about 100 ° C. to 200 ° C. and mix.
Mix ACK 3. Next, an antioxidant is added, and the mixture is stirred and mixed at 200 to 10000 rpm, preferably 500 to 5000 rpm by the above-mentioned dissolver. The composition obtained by stirring and mixing is filtered by a heating filter manufactured by Toyo Roshi Co., Ltd. using a 2 μm mesh filter to obtain a final hot-melt ink.

The prepared hot-melt ink was heated at 130 ° C.
When stored in an environment for 10 days, the viscosity reduction rate was 1.0 (%) and the weight reduction rate was 2.0 (%).
The surface tension in an environment at 120 ° C. is 27.0.
(MN / m).

The prepared hot-melt ink was applied to coated paper, film, and aluminum, and the adhesiveness was confirmed by the presence or absence of peeling when bent at 180 degrees. Peeling occurred in any of the coated paper, film, and aluminum. It was confirmed that the adhesiveness of the hot-melt ink of Comparative Example 1 was poor.

The printed matter obtained by printing the prepared hot-melt ink on plain paper was stored at 50 ° C. for 48 hours in an environment, and the printed matter before and after storage was compared to confirm the high-temperature storage property of the printed matter. However, no difference was confirmed in the printed matter before and after storage, and good printed matter high-temperature storability was confirmed.

The printed matter obtained by printing the prepared hot-melt ink on plain paper and plain paper are combined, and the temperature is 60 ° C., 50% RH.
The anti-blocking property was confirmed by being left under a load of 2 kg under an environment for 24 hours and inspecting whether or not set-off occurred. Set-off to plain paper was confirmed, and it was confirmed that the blocking resistance was poor.

Comparative Example 2 The ink composition in Comparative Example 2 is as shown below.

9. Paraffin wax (HNP-12, manufactured by Nippon Seisaku) 40.0% by weight amide stearic acid (Amide S, manufactured by Kao) 42.9% by weight montanic acid ester wax (Hoechst wax E, manufactured by Hoechst) 0% by weight Di-ethylhexyl phthalate (Kanto Chemical) 5.0% by weight Antioxidant (Irganox 1010, Ciba Specialty Chemicals) 0.1% by weight Colorant (SOLVENT BLACK 3 (Oil Black HBB, manufactured by Orient) )) 2.0% by weight The hot-melt ink of Comparative Example 2 can be prepared by the following method.

First, paraffin wax, stearic acid amide, montanic acid ester wax, diphthalic acid
Ethylhexyl (manufactured by Kanto Chemical Co., Ltd.)
Preferably, the mixture is heated and dissolved at a temperature of about 100 ° C. to 200 ° C. and mixed, and SOLVENT BLACK 3 is mixed as a coloring material with the mixed liquid. Next, an antioxidant is added, and 200 to 10,000 rpm, preferably 5
Stir and mix at 00-5000 rpm. The composition obtained by stirring and mixing is filtered by a heating filter manufactured by Toyo Roshi Co., Ltd. using a 2 μm mesh filter to obtain a final hot-melt ink.

The prepared hot-melt ink was heated at 130 ° C.
When stored in an environment for 10 days, the viscosity reduction rate was 6.0 (%) and the weight reduction rate was 5.0 (%).
The surface tension in an environment at 120 ° C. is 27.0.
(MN / m).

The adhesiveness was confirmed by the presence or absence of peeling when the prepared hot-melt ink was applied to coated paper, film, or aluminum and bent at 180 °, but no peeling was observed in any of the coated paper, film, and aluminum. Excellent adhesiveness was confirmed.

The printed matter obtained by printing the prepared hot-melt ink on plain paper was stored at 50 ° C. for 48 hours in an environment, and the printed matter before and after storage was compared to confirm the high-temperature storage property of the printed matter. However, a difference was confirmed in the printed matter before and after storage, and it was confirmed that the printed matter had a poor high-temperature preservability. Specifically, thickening of characters due to occurrence of bleeding was observed.

The printed matter obtained by printing the prepared hot-melt ink on plain paper and the plain paper were combined, and the temperature was 60 ° C., 50% RH.
The anti-blocking property was confirmed by leaving the product under a load of 2 kg under an environment for 24 hours and inspecting whether or not set-off was observed. However, set-off to plain paper was confirmed, and the anti-blocking property was poor. It was confirmed.

Comparative Example 3 The composition of the hot-melt ink in Comparative Example 3 is as shown below.

Paraffin wax (HNP-12, manufactured by Nippon Seisaku) 40.0% by weight Amide stearate (Amide S, manufactured by Kao) 42.9% by weight Montanate ester wax (Hoechst wax E, manufactured by Hoechst) 10.0 Weight% Hydrocarbon solvent (Isoper M, manufactured by Exxon Chemical) 5.0% by weight Antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) 0.1% by weight Colorant (SOLVENT BLACK 3 (Oil Black HBB, Orient) 2.0% by weight) The hot-melt ink of Comparative Example 3 can be prepared by the following method.

First, paraffin wax, stearic acid amide, montanic acid ester wax, and a hydrocarbon solvent are added at 70 ° C. to 250 ° C., preferably 100 ° C. to 200 ° C.
Heat and dissolve at about the temperature and mix. SOLVENT BLACK 3 is mixed with this mixture as a coloring material. Next, an antioxidant was added, and 200 to 10,000
Stir and mix at rpm, preferably 500-5000 rpm. The composition obtained by stirring and mixing is filtered by a heating filter manufactured by Toyo Roshi Co., Ltd. using a 2 μm mesh filter to obtain a final hot-melt ink.

The prepared hot-melt ink was heated at 130 ° C.
When stored in an environment for 10 days, the viscosity reduction rate was 25.0 (%) and the weight reduction rate was 12.0 (%). The surface tension in an environment of 120 ° C. is 27.
0 (mN / m).

The adhesiveness was confirmed by the presence or absence of peeling when the prepared hot-melt ink was applied to coated paper, film, or aluminum and bent at 180 °. Peeling was observed in any of the coated paper, film, and aluminum. The adhesion was confirmed to be poor.

Printed matter obtained by printing the prepared hot-melt ink on plain paper was stored in an environment of 50 ° C. for 48 hours, and the printed matter before and after storage was compared to confirm the high-temperature storage property of the printed matter. However, no difference was confirmed in the printed matter before and after storage, and good printed matter high-temperature storability was confirmed.

The printed matter obtained by printing the prepared hot-melt ink on plain paper and plain paper are combined, and the temperature is 60 ° C., 50% RH.
The anti-blocking property was confirmed by leaving the specimen under a load of 2 kg under an environment for 24 hours and inspecting whether or not set-off occurred. However, set-off to plain paper was confirmed, and the anti-blocking property was poor. It was confirmed.

Comparative Example 4 The composition of the hot-melt ink in Comparative Example 4 is as shown below.

Paraffin wax (HNP-12, manufactured by Nippon Seisaku) 40.0% by weight Amide stearate (Amide S, manufactured by Kao) 42.9% by weight Montanate ester wax (Hoechst wax E, manufactured by Hoechst) 10.0 Weight% Straight silicone oil (KF-96-100, manufactured by Shin-Etsu Chemical) 5.0% by weight Antioxidant (Irganox 1010, manufactured by Ciba Specialty Chemicals) 0.1% by weight Colorant (SOLVENT BLACK 3 (Oil Black) HBB, manufactured by Orient)) 2.0% by weight The hot-melt ink of Comparative Example 4 can be prepared by the following method.

First, paraffin wax, stearic acid amide, montanic acid ester wax, and straight silicone oil (KF-96-100, manufactured by Shin-Etsu Chemical Co., Ltd.) were heated at 70 ° C.
To 250 ° C, preferably 100 ° C to 200 ° C, and heat-dissolve and mix.
Mix T BLACK 3. Next, an antioxidant was added, and the above-mentioned dissolver was used for 200 to 10,000 rpm,
Preferably, stirring and mixing are performed at 500 to 5000 rpm. The composition obtained by stirring and mixing is filtered by a heating filter manufactured by Toyo Roshi Co., Ltd. using a 2 μm mesh filter to obtain a final hot-melt ink.

In the hot-melt ink prepared by the above method, the silicone oil separated from the ink vehicle, and it was impossible to carry out the above evaluation.

FIG. 2 is a table summarizing the evaluations of the inks of Examples 1 to 5 and Comparative Examples 1 to 3 described above. As can be seen from the evaluations of the inks of Examples 1 to 5 and Comparative Examples 1 to 3 described above, Comparative Example 1 not having the requirements of the present invention.
Ink Nos. 1 to 3 did not have satisfactory performance, and Examples 1 to 5 having the requirements of the present invention were able to obtain satisfactory evaluations as compared with these inks. In particular, the inks of Example 1 and Example 2 were desirable.

[0091]

As described above, in the hot-melt ink of the present invention having the above constitution, as a plasticizer, an alkyl-modified silicone oil, a higher fatty acid ester-modified silicone oil, a methylstyryl-modified silicone oil, an alkyl aralkyl polyether-modified silicone oil, pyromellitic The addition of the acid tetraoctyl ester has the effect that the surface tension can be significantly reduced. Therefore, even when printing is performed on coated paper (especially, coated paper dedicated to water-based ink jet), it is possible to form a strongly adhered print image.

Further, since a plasticizer which has high heat resistance and can be stored at a high temperature for a long period of time is used, there is an effect that a stable ink which is hardly deteriorated even when stored at a high temperature for a long time can be obtained. In particular, since this plasticizer has high compatibility with the ink vehicle and does not separate even when left in a high temperature state, there is an effect that it is possible to prevent an increase in ink viscosity. Furthermore, the plasticizer does not separate and migrate to the ink surface to cause stickiness, and in addition, the plasticizer that has melted the dye spreads without causing the plasticizer to melt the dye and causes bleeding. There is an effect that it is also possible to prevent other things. Moreover,
There is also an effect that the flash point is high and safe.

[Brief description of the drawings]

FIG. 1 is a diagram showing a procedure for preparing a hot-melt ink of Example 1.

FIG. 2 is a table summarizing evaluations of inks of Examples 1 to 5 and Comparative Examples 1 to 3.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paraffin wax 2 stearic acid amide 3 montanic acid ester wax 4 alkyl-modified silicone oil 5 antioxidant 6 colorant (SOLVENT BLACK 3) 11 composition stirred and mixed 12 heat-meltable ink 21 dissolver 22 mesh filter

Claims (2)

[Claims] 1. A hot-melt ink which is solid at room temperature and becomes liquid at a temperature higher than room temperature, is heated and melted in a printing apparatus having an ink jet head, and is used for printing, and is room temperature compatible with an ink vehicle. A hot-melt ink containing at least one of liquid alkyl-modified silicone oil, higher fatty acid ester-modified silicone oil, methylstyryl-modified silicone oil, and alkylaralkyl polyether-modified silicone oil. 2. A hot-melt ink which is solid at room temperature and becomes liquid at a temperature higher than room temperature, is heated and melted in a printing apparatus equipped with an ink-jet head and is used for printing, and is compatible with an ink vehicle at room temperature. A hot-melt ink containing liquid tetraoctyl pyromellitic ester.