JPS63109083A - Inkjet recording method - Google Patents

Abstract

PURPOSE:To obtain an ink jet recording capable of producing a recorded matter with high recording liquid fixation properties and water resistance, by incorporating a thermosetting resin into a recording liquid, and rapidly hardening the recording liquid thermally after the liquid is adhered to a recording paper. CONSTITUTION:A recording head 5 is moved in the direction of an arrow I by being guided by a carriage guide 6 while being supplied with a recording liquid from a recording liquid tank 15 through a recording liquid supplying pipe 16, and performs ink jet recording on a recording paper intermittently fed (for line feeding) by a paper-feeding roller 2 and a guide roller 4 in synchronism with the head 5. When a thermosetting resin is added to the recording liquid, a solvent consisting mainly of water in the recording liquid is evaporated after adhesion of the recording liquid to the recording paper, and simultaneously, the thermosetting resin is rapidly hardened. The resin thus thermally hardened has strong adhesiveness and is insoluble in water. Therefore, a coloring agent such as a dye and a pigment is protected by the hardened resin, so that the recording liquid fixation properties and water resistance of the recorded matter are enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an inkjet recording method capable of writing entire recorded matter with high recording liquid fixability and water resistance.

[Conventional technology]

Representative examples of inkjet recording apparatuses having recording liquid heating means include Japanese Patent Laid-Open Nos. 55-69464 and 55-846.
70, which heats the entire grating with a heating element installed inside the platen, and heats the back side of the recording paper, as well as JP-A Nos. 57-120447 and 58-10.
There are FE devices that heat the surface of recording paper by irradiation with far-infrared infrared lamps and xenon lamps as shown in No. 7345, which quickly dries the recording liquid and eliminates unnecessary bleeding, wrinkles, and unfixed records. This is an effective means for preventing stains caused by liquid and achieving high-resolution and high-quality image recording.

[Problem that the invention seeks to solve]

However, in the recording using the above-mentioned conventional technology, since the recording liquid penetrates into the recording paper very little, the recording liquid fixability and water resistance of the recorded material are low, and the recording paper may become smudged due to rubbing or water There was a problem in that the print would disappear if it got wet.

The present invention is intended to solve such problems, and its purpose is to provide an inkjet recording method that can obtain recorded matter with high recording liquid fixability and water resistance by improving the recording liquid. It is here.

[Means for resolving issues]

In the inkjet recording method of the present invention, it is assumed that the recording liquid contains a thermosetting resin.

The object of the present invention is achieved using the inkjet recording apparatus Me shown in FIG. 1.3. The configuration of this inkjet recording apparatus will be explained.

FIG. 1 is a schematic overall configuration diagram showing a first row of a printing apparatus equipped with an inkjet printing method of the present invention.

In FIG. 1, the recording head 5 is guided by the carriage guide 6 and moves in the direction of the arrow (■) while being supplied with the recording liquid from the recording liquid tank 15 through the recording liquid supply pipe 16. Inkjet recording is performed on a recording paper that is fed by a roller 4 in an intermittent line feed synchronization with a recording head 5.

In FIG. 2, the recording head 5 has a plurality of recording liquid ejection ports 1.
3 is provided for piezoelectric element control and electric field control.

One row of recording heads 5, which form dots on the recording paper 3J by means of recording liquid discharge means such as charge control and thermal inkjet recording, discharges recording liquid in one vertical column at intervals of 0.141 ax pitch. It is a piezoelectric element controlled recording head equipped with an outlet, and discharges recording droplets of approximately 0.5 μ2 in size.

The fixed platen 1 is suitably made of a material with good heat diffusion such as aluminum alloy or thermally conductive plastic material.

In this example, an aluminum alloy plate with an average thickness of 1W and a size of approximately 250 m x 301 J is used. As shown in FIG. 2, a heating element 12 is provided on the back side of the fixed platen 1 that does not face the recording head 5. 1 heating element 12Fi rated voltage applied V normal temperature average resistance rI! It is appropriate to arrange five 22Ω PTC thermistors for heaters evenly, or to use a sheath heater of about 100V and 250W.

77-17 indicates that the water vapor generated from the recording paper as the recording paper 3 is preheated and heated, and the water or solvent vapor in the recording liquid attached to the recording paper are transferred to the recording head 5 or the curl removal flow/F-14. Alternatively, the paper presser foot 7 is attached to the guide roller 4, etc., cooled, and exhausts the steam to the outside of the recording apparatus to prevent dew condensation. It also promotes evaporation of the printed recording liquid.

Returning to FIG. 2, the recording paper 3 is in sliding contact with the fixed platen l heated by the heating element 12, and is preheated and heated before and after inkjet recording by contact heat transfer, and the recording liquid recorded by the inkjet is attached to the recording surface. Rapid drying afterwards prevents unnecessary dot bleeding, paper wrinkles, and stains from unfixed recording liquid, resulting in good print quality! The paper presser 7 prevents the recording paper 3 from floating, and also brings the recording paper 3 into close contact with the fixed platen l to provide a heat conduction effect.

By preheating and heating the recording paper 3, the recording paper 3 is curled along the shape of the fixed platen 1.

In order to remove this curl, the recording paper 3 is wound around a curl removing roller 14 after inkjet recording, and the curl is removed by curling it in the opposite direction to the curling direction, and the recording paper 3 is taken out in a flat state. be able to.

FIG. 3 is a schematic diagram showing the entire configuration of the second row of the recording apparatus equipped with the inkjet recording method of the present invention.

The recording head 5 is guided by a carriage guide 6 and moves in the direction of arrow I, and performs inkjet recording 8 on the recording paper 3 which is intermittent line feed fed in synchronization with the recording head 5 by the single paper feed roller 2 and guide roller 4. On the other hand, the light radiation from the first heat source rung 18 is, for example, a paraboloid, an ellipsoid,
By means of a reflector having a curved surface such as a hyperboloid, the recording portion of the surface of the recording paper 3 is irradiated with focused light in a heating range 4 extending before and after recording, and is heated by width-thickness heat transfer. In addition, the air flow sent from the blower is directed to the air inlet path 25 by the arrows ■ and Ill.
As shown in FIG. 2, the light is sent to the lamp house section composed of the reflective side plates α, 22b of the reflector plate 11 and transparent glass blades, and the one heat source lamp 18 and the lamp house section are cooled by air. After cooling, the air flow passes through the air discharge path zskfV*V and is discharged from the air discharge port n toward the recording surface of the recording paper 3, and the convective heat and conductive heat generated by the first heat source lamp 18 is transferred to the recording paper surface. Blow heat is transferred.

The recording head 5 has a plurality of ink ejection ports 1 as shown in FIG.
3 is provided for piezoelectric element control and electric field control.

Dots are formed on the recording paper 3) by an ink ejection control means such as charge control, and are recorded using a drawing method.

In this example, a piezoelectric element is used, and 24 recording liquid ejection ports are arranged in a vertical row with a 0.141 wx pinch, and recording liquid droplets of about 0.5 μt are ejected.

The heat source lamp 18 is an incandescent lamp typified by a halogen lamp, a quinanone lamp, or an infrared eyelid lamp, and in this example, a rod-shaped halogen lamp of 200 W and a total length of 250 u is used. The recording width of the recording paper 3 is 220w5, and a lamp with an effective light emitting section at least as long as this length is required. heating range 28
Metal radiation heats up. The heating state of the recording paper 3 is detected by a temperature sensor 4 as shown in the fourth prisoner, compared with the set temperature by a comparison circuit built in the light amount control circuit 19, and the temperature of the recording paper 3 is approximately set using optical i feedback. It is kept in a stable position. @The degree sensor 29 is the recording paper 3 in Fig. 4.
Although the temperature is set on the front side of the recording paper 3, it may also be set on the back side of the recording paper 3. Furthermore, the user can freely control the set temperature according to the paper quality.

The blower U is a fan with an air flow rate of about 3 m''/min.The direction of the air flow discharged from the air outlet 4 is adjusted so as not to affect the discharge of the recording liquid.The light-shielding cover 21 is attached to the recording head. This prevents direct light radiation from becoming cloudy and prevents the recording head from being heated.

In addition, the transparent glass prevents dust from adhering to the heat source lamp 18 and the reflector plate.

For proper preheating-heating temperature of recording paper, 170″C
If it exceeds ', the recording paper will smoke or change color, and if it is less than the leap degree, the evaporation of the recording liquid will be slow and it will take a long time for the recording liquid to fix on the recording paper.

Print quality is poor. Therefore, it is desirable that the preheating/heating temperature of the recording medium and the attached recording liquid be 80 to 170°C.

Next, the recording liquid of the present invention will be explained.

When printing using the above-mentioned inkjet recording device by preheating and heating the paper to a temperature of 80 to 170'CK, if a thermosetting resin is added to the recording liquid, after the recording liquid adheres to the recording paper, the recording liquid The solvent, mainly water, vaporizes, and at the same time, the thermosetting resin rapidly hardens.

The thermoset resin has strong adhesion to paper fibers and is unfriendly to water. Therefore, in order to protect colorants such as dyes and pigments, the recording liquid fixability and water resistance of recorded matter are improved. The thermosetting resin to be added is preferably water-soluble before thermosetting, but even water-insoluble resins can be used by uniformly dispersing them in the recording liquid. for example.

Urea resins, melamine resins, phenol resins, acrylic resins, alkyd resins, polyester resins, epoxy resins, vinyl acetate resins, silicon resins, or co-condensed resins thereof can be used. More specifically, Eurane P, Eloid, Cymel, Almatex, VFR (Mitsui Toatsu Chemical Resin, Woodrock, Kanebinol (also manufactured by Kanebo NSC)) FWP, Dianol (
Hard Rock (manufactured by Near Sea Eye)
If the amount added is less than 0.1% by weight based on the total weight of the recording liquid, the amount of resin after curing will be insufficient to protect the colorant, and addition of a large amount of resin will increase the curing energy. Because of this increase, heating requires a high temperature and a long time, which is a disadvantage in increasing the speed and reducing the cost of recording devices. Therefore, the recording liquid used in the present invention desirably contains a thermosetting resin of 0.1 to 20 percent heavy needles.

Those containing J-■ weight percent can also be used.

Many conventionally known dyes and pigments are effective as colorants. Typical dyes include various azo dyes, indevoid dyes, and phthalocyanine dyes.
Specifically, C6 construction, direct black 19. C, engineering, direct black rho, C0 engineering.

Direct black 38. C, Engineering, Direct Black 154, C, Engineering, Direct Yellow 12. C, Engineering, Direct Yellow 26. C, Engineering, Direct Red 13. C.

Engineering, Direct Red 17. C, Engineering, Direct Blue 80, Engineering, Direct Blue (I), C0 Engineering, Acid Black 52, C, Engineering, Acid Yellow 5. C1 construction, acid red 37. C, Engineering, Acid Red 52.
C, Eng., Ashitudretsu) '254. C, Engineering, Acid Blue 9, etc. can be used. As the pigment, inorganic pigments and organic pigments with a particle size in the range of 0.01 to 3 μm can be used.1 It is best to disperse using a dispersant.1 The amount of colorant added is usually 0.1 to 3 μm. The amount is desirably 10% by weight, preferably 0.5 to 5% by weight, most preferably 1 to 3% by weight, and two or more types may be added to obtain the desired hue.

Examples of solvents include polyhydric alcohols and derivatives thereof as wetting agents, specifically glycerin, diethylene glycol,
Thiodiglycol, triethylene glycol, polyethylene glycol +200°300.400. Diethylene glycol monomethyl ether, diethylene glycol diethyl ether, etc. can be used. If the amount added is too small, the wetting ability of the ink will decrease and the nozzle of the inkjet head will become clogged, and if it is too large, the drying time of the recording liquid on the recording paper will be delayed, so a range of 5 to 20% by weight is appropriate. It is.

Furthermore, in addition to the above-mentioned components, preservatives, antifungal agents, pH adjusters, and chelating agents can also be appropriately added to the recording liquid used in the present invention.

[Implementation row]

The present invention will be explained in detail below.

Table 1 shows typical medium- and high-quality papers used for printing.

The actual row and comparison row of the recording paper used for printing are shown below.

J: Pour the mixture with the following composition into a container, stir thoroughly, and reduce the pore size to lμ.
The recording paper is filtered under pressure using an ordinary membrane filter, and used as a recording liquid after deaeration treatment. Approximately 0.5μ for each nozzle
Recording liquid droplets of f were ejected to print on the recording paper shown in Table 1. After the recording liquid was attached, heating was continued, and the area where the first class droplets were attached was rubbed with gauze, and when the recording paper was no longer stained, drying and thermosetting of the resin were considered complete.

In order to examine the fixability of the recording liquid on the above-mentioned recorded matter, the recording liquid was strongly rubbed with wet gauze to allow the recording liquid to flow.

The dirt is so bad that it is impossible to distinguish one character.
Difficult to read letters ∆It gets dirty, but one letter is clearly written O Marita〈Not dirty
It was judged as ◎. The results are shown in Table 3. Regarding water resistance, the recorded matter was immersed in water, and the shape after a period of time was determined.

The printing has disappeared and it is impossible to distinguish one character. × The printing has become so faint that it is difficult to read one character. ∆ The printing is not good, but one character can be clearly read. ○ The printing condition has not changed at all. It was rated as ◎. The results are shown in Table 4.

〔Effect of the invention〕

According to the inkjet recording method of the present invention, since the recording liquid contains a thermosetting resin, after adhering to the preheated recording paper,
When heated further, the water and solvent evaporate and the resin hardens at the same time, resulting in strong adhesion to paper fibers and protecting the colorant, making it possible to obtain a recorded matter with high recording liquid fixability and water resistance. Furthermore, since most of the water in the recording liquid evaporates and the amount that permeates into the recording paper is extremely small, paper wrinkles do not occur in high-density recording such as hard copies of images and color printing5, and the effect is is big.

[Brief explanation of the drawing]

FIG. 1 is a schematic overall configuration diagram showing a first example of a recording apparatus equipped with an inkjet recording method of the present invention, and FIG. 2 is a partial side view of FIG. 1. Fig. 3 is a schematic overall diagram showing a second example of a printing apparatus equipped with the inkjet printing method of the present invention, and Fig. 4 is a partial side view of Fig. 3. Figure 2

Claims (1)

[Claims] An inkjet recording method in which a recording liquid attached to a recording medium is heated at a temperature higher than room temperature, characterized in that the recording liquid contains a thermosetting resin, and the recording liquid is rapidly thermosetted after being attached to the recording paper. An inkjet recording method.