JPS62112672A - Ink for jet - Google Patents

Abstract

PURPOSE:To provide ink for jet, which gives a printing of good quality and has a short warming-up time, by mixing a coloring material with a solvent which is solid at room temp., but is liquefied by heating, and a solvent which can dissolve said solvent and is liquid at room temp. and highly volatile. CONSTITUTION:A coloring material is mixed with a first solvent which is solid at room temp., but is liquefied by heating it at a temp. higher than room temp. (e.g., polyethylene glycol, 1,2-hydroxystearic acid) and a second solvent which can dissolve said first solvent and is liquid at room temp. and highly volatile (e.g., ethyl alcohol, dichloromethane) to obtain the desired ink for jet. When printing is made, the second solvent is rapidly evaporated so that the first solvent is precipitated and solidified to give a printing of good quality. The first solvent solidified by the evaporation of the second solvent within a head near a nozzle can be easily recovered by heating the head.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to improvements in inks for vintage inkjet. More specifically, the present invention relates to an ink that provides good print quality on various types of paper.

[Conventional technology]

Technology and shite that provide good print quality on various paper types,
Example f-Ha BP! f Kaisho 58-10'82711c, I
! It has been proposed to inject a solid ink at a high temperature and deposit it on the recording medium, which results in a ready-to-fix ink.

[The problem that the invention attempts to solve]

However, when trying to put the above-mentioned proposal into an actual product, it requires a lot of energy and heating time to completely melt the solid ink, and the ink supply mechanism to the head is subject to many limitations. There were some problems, such as difficulty in installing the ink tank and the ink tank separately.

Therefore, it is an object of the invention to provide an inkjet device that requires less energy and has a shorter warm-up time.

Another object of the present invention is to avoid complicating the ink supply mechanism to the head.

Still another object of the present invention is to provide an entire inkjet device that provides good print quality.

[Means for solving problems]

The jet ink of the present invention includes a coloring material, a first solvent that is solid at room temperature and liquefies when heated above room temperature, and a second solvent that is liquid at room temperature and highly volatile that completely dissolves in the tenth bath medium.
and a solvent.

[Effect]

According to the above configuration of the present invention, since the first solvent is normally dissolved in the liquid second solvent at room temperature and is in a liquid state, the process from the ink tank to the head is the same as in a conventional general liquid inkjet. Since the second solvent quickly evaporates during printing, the first solvent precipitates and solidifies, giving good printing quality. Also, inside the head near the nozzle (
7) Solidification of the first solvent due to evaporation of the '1E2 solvent can be easily recovered by heating the head.

[Structure of the invention]

The first solvent used in the present invention, which is solid at room temperature and liquefies when heated to a higher temperature than room temperature, includes high molecular weight polyhydric alcohols, cellulose derivatives, oxidized hydrocarbon waxes, natural waxes, and other synthetic waxes. Specifically, as high molecular weight polyhydric alcohols, polyethylene glycol (hereinafter abbreviated as PEG), molecular weight (hereinafter referred to as
+)2000, PEG+4QO(], PIIXG+
6000゜PmG$211000 Cellulose acetate (6 degree s1s~56'1
As nitrocellulose oxidized hydrocarbon waxes, 1-dodecanol,
1-tetradecanol, 1-hexadecanol. 1-octaditanol, 1-eicosanol, 1-docosanol* 1-7 h lacosanol.

1-hexacosanol. Myricyl alcohol, 9-dodecen-1-ol, 9-tetradecen-1-ol, 9
-hexadecen-1-ol, 9-oftatecen-1-
ol, 9-diicosen-1-ol, 13-tocosen-1-ol, 9-12-octadecadien-1-ol, 9,12゜15-octadecatrien-1-ol, 5,8゜11, 1.4-eicosatetraene-
1-all.

4.8.12,15.19-docosapenten-1-ol, 1.10-decanodiol, 1.11-undecanediol, 1.12-dodecanediol, 1.14-tetrazocadiol, 1°16- xadecanediol, 1.18-octadecanediol, 1.20-eigosandiol.

1.22-Tocosandiol, 1.24-Tetracosandiol 12-Hydroxystearic acid, Fatty acid amide, Tsukishima stearic acid ester, NFS-6010, NFS-6115,0
X-0207, NFS-8070゜NFS-8020,
NFS-81! S5. NFS-L-70, NFS-92
10, NPB-9125゜NFS-9035,0X-1
949, Paracol 5011 [1, Paracol 5010
(Japanese octopus *■ Oxidized wax mark) Natural waxes and synthetic waxes include diundecylketone (lauron), dihebutadicylsatone (stearon), and 2-macetonaphtonepehenic acid.

Examples include valmitic acid, lauric acid, teglic acid, urucamide, stearamide, erucic acid, oleic acid, midodinosterin, -1-tubalmitin, t-caprolactam, maleic anhydride, and the like.

The melting point i of the first solvent is 50°C to 150°C, more preferably 60°C to 120°C. This is because if the melting point is lower than this, the first crystal that precipitates and solidifies after printing.
This is because the solvent dissolves at room temperature, staining the paper, degrading print quality, and causing a phenomenon called blocking, where papers stick to each other. If the melting point is too high, the first solvent will precipitate and solidify too quickly after the second solvent evaporates, making it impossible to fix it in the paper fibers and causing the first solvent to peel off from the paper. This is because it becomes impossible to provide good printing quality. Further, these first solvents can be used alone or in a mixture of 2P4 or more depending on the intended physical properties such as melting point and viscosity of the ink.

Further, the second solvent which is liquid at room temperature and has high volatility that dissolves the first solvent includes water, halogenated hydrocarbons, alcohols, and ketones. Hydrogens include dichloromethane, trichloroethylene, alcohols, methyl alcohol, and ethyl alcohol.

Examples of isopropyl alcohol ketones include dimethyl ketone (acetone) and methyl ethyl ketone.

The second solvent has a boiling point of 30°C to 100°C, more preferably 40°C to 100°C. This is because if the boiling point is lower than this, the second solvent in the ink will evaporate during printing, making the physical properties of the ink unstable and making it difficult to maintain stable printing quality. At the same time, the ink at the nozzle orifice eventually solidifies, making it impossible to print.
It's your body. Moreover, if the boiling point is higher than this, the evaporation rate of the second finished medium is slow on the paper surface after printing, resulting in blurring of the print. Further, these second solvents can be used singly or in a mixture of 21 or more, depending on the desired boiling point (vapor pressure).

Also, for visualization, coloring materials (particularly dyes and pigments), such as, for example, oil- or solvent-soluble dyes, are added to the composition. Specifically, C1 engineering, 5olventY
rl'low 2, 6, 1 4
, 1 5.

1 6.19,21,56゜61.80 C8 engineering, 5olvent Ovange 1
．． 2. 5. 6, 14.

37, 40, 45 C1 engineering, 5olvent Re6 1
# 8 * 2 3 + S Or49.
81,82,83 84.100,109°C9■, Elolvent Violet
8, 1 3, 1 4, 2 1.

C1 engineering, 5olvent Blue 2
, 1 2 , 2 5 , 5 5 .

C6 construction, day o'1vent Black
3, 5, 7, 2 2, 2 5
0, L Ac1d 1lnack 1 2
3 (Solvent dye) These dyes and pigments are the first solvent component of the ink of the present invention.
Although it varies depending on the color, (L 1 to 10 wt %, preferably CL 5 to 5 wt %) is suitable. Excess dye and pigment content may increase the viscosity of the ink or If it is too high, the color and density of the print will be lacking, which is not desirable.

Furthermore, when using pigments, they must be atomized and dispersed into particles of 1 μm or less in consideration of the occurrence of clogging due to agglomeration.

Furthermore, if the first solvent has a color, it can also serve as a coloring material.

In addition, the ink used in the present invention may clog the ink path during use due to the growth of microorganisms or mold, so 1Bucoside N-96 (San 1Pco C scoop anti-mold agent trademark) 1001 antifungal agents and preservatives such as
~[Ll wt% can be added.

In order to achieve the above object, the ink of the present invention can tolerate a wide range of ink viscosity, and can perform printing by heating the head, if necessary. Specifically, 2. at room temperature.
The viscosity range is from 0 mPa8 to 500 mPa5, and the heat temperature by head is from room temperature to 100C.

〔Example〕

Example 1 Polyethylene glycol Φ6000 41LOP was placed in a beaker, heated and melted at 80°C, and O,
1.8 o 1vent Black f 20 f Weighed 25.
Of, ethyl alcohol '15. Off: Add and stir to mix to make a uniform solution. Thereafter, filtration was performed using a Teflon membrane filter (bottom size: 1 μm) to remove undissolved substances and impurities, and an ink having the following composition was obtained.

Compositional viscosity f 100+nPa5 (25℃) 80 mPa8
(70°C) Example 2 An ink with the following composition was obtained in the same manner as in Example 1. Composition Example 3 An ink with the following composition was obtained in the same manner as in Example 1. Composition Example 4 Example 1 In the same manner as above, an ink having the following composition was obtained.

composition Example 5 An ink having the following composition was obtained in the same manner as in Example 1.

Composition Example 6 Cellulose acetate-h (acetyl fK s 1i ) 4
a.

? To the f crack, add acetone 5aOfi and stir at room temperature to make a homogeneous solution, and then add dye C1.

5olvent Black 2. Add Of, 2
After stirring and dissolving for a period of time, use a Teflon membrane filter (1
The entire ink was filtered using a microcosm (μ inertia) to remove undissolved matter and impurities, and an ink having the following composition was obtained.

Composition Comparative Example 1 An ink was prepared using the composition of Example 2 except that ethyl alcohol was removed.

Composition viscosity 3 a OmPa,s (100C) Melting point 8
0°C Comparative Example 2 An ink was prepared using the composition of Example 4 except that trichlene was removed.

Composition viscosity $ 9.0 mPa, s (100℃) Melting point
87℃ The inks of Examples 1 to 6 and the inks of Comparative Example 1.2 were put into a tank, mounted on a printer, and the ink was filled into the head. After ejecting the ink at room temperature for one week, it was possible to print. When the initial operation time was investigated, the results are shown in Table 1.

In addition, after printing for a certain period of time, the head was left at room temperature and printed again, and the head equipped with the ink of Comparative Example 1゜2 was found to have air bubbles inside the head from the nozzle tip during cooling and assimilation after printing. There was a phenomenon in which the ink was taken in, and when printing was performed again, the ink stopped flying from some nozzles and the ink went down.

In contrast, with the inks of Examples 1 to 6 of the present invention, the nozzle tip solidified as the second solvent evaporated;
The inside of the head did not solidify, so no air was drawn in from the nozzle or bubbles were generated within the head. As a result, good printing power 1 was immediately achieved by heating and melting a small portion of the nozzle tip during the reprinting operation. In addition, by heating and melting the solidified ink at the tip of the nozzle and driving the ink barge pump, relatively high viscosity ink is pushed out of the nozzle, and steady printing is performed using low viscosity ink, resulting in even more stable printing. was completed.

[Effects of the Invention] As can be seen from the above explanation, the jet ink of the present invention has a wide applicable viscosity range, and during normal use, it is possible to supply ink and print in the same way as a conventional general inkjet. In addition, the solidification of the first solvent due to evaporation of the second solvent in the head near the nozzle heats the head, and the first solvent melts to enable printing, which reduces the viscosity of the ink during printing. It can be held over a wide range, and furthermore, the solidification of the first solvent at the tip of the nozzle eliminates the need for a mechanical nozzle cap to prevent drying, making it easy to use +! It is possible to provide an inkjet printer that is highly reliable because there is no air bubbles or seepage into the head, and that can provide good print quality on any paper.

that's all

Claims (1)

[Claims] A jet ink comprising a coloring material, a first solvent that is solid at room temperature and liquefies when heated above room temperature, and a second solvent that is liquid at room temperature and highly volatile and dissolves the first solvent. .