JPH0752531A - Coating material of medium to be recorded and recorder - Google Patents

Abstract

PURPOSE:To print and record without flow and stain of ink by incorporating cellulose derivative in a coating material to be used to coat, before adherence of the ink, a medium to be recorded for ink jet recording. CONSTITUTION:When a medium 103 to be recorded is conveyed in a direction of an arrow 102 by rotating a platen roller 101 and an end of the medium 103 wound on the roller 101 is rotated to a position of a coating roller 124, a coating unit 125 is pressed to the roller 101 by pressing means. The medium 103 is coated by the roller 124. As a coating material to be used for the coating, a material containing 0.5 to 15% of cellulose derivative is used. After the coating film is formed, ink jet recording is conducted by an ink jet recording head 111.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating material for coating the surface of a recording medium for ink jet recording, and particularly to obtain stable high-quality printing without being affected by the type of recording medium. The present invention relates to a recording apparatus having a coating material for a recording medium and a coating means for coating the coating material for the purpose.

[0002]

2. Description of the Related Art Ink jet recording systems use various ink ejection systems such as an electrostatic suction system, a system in which a piezoelectric element is used to mechanically vibrate or displace the ink, and the ink is heated and foamed to utilize its pressure. The method is to generate and fly small droplets of ink, and then attach some or all of them to a recording medium such as paper for recording, which produces less noise, high-speed printing, and high-quality printing. It is attracting attention as a recording method that enables printing and multicolor printing.

A recording medium used for such ink jet recording has an inorganic pigment on the base paper so that the ink adhered on the recording medium does not bleed or flow to impair the printing quality. Such as special inkjet paper coated with a layer of a special material that is porous and has a large water absorption capacity and that adsorbs the coloring components in the ink, and a special film for inkjet that has a special surface treatment to prevent the ink from flowing. , A dedicated recording medium that has undergone a special process for inkjet is used.

[0004]

However, there is a problem that high-quality printing and recording cannot be performed unless such a limited recording medium is used. Furthermore, if a user who handles a print recording apparatus using an inkjet recording system mistakenly uses a different type of recording medium, not only high quality print recording cannot be performed due to ink bleeding,
There is a problem that the flow of ink causes fatal contamination inside the print recording apparatus.

Further, there has been a problem that these recording media are expensive due to the above-mentioned special treatment and special materials. Therefore, an object of the present invention is to solve the problems as described above, and to enable high-quality ink jet recording without being limited to the type of recording medium, an inexpensive coating material for recording medium and recording It is in the area of providing equipment.

[0006]

The above-mentioned problems can be solved by the following constitution of the present invention. That is, the present invention provides a recording medium used for inkjet recording,
It is a recording device having a coating material characterized by containing a cellulose derivative in a coating material used for coating before ink is applied by ink jet recording, and a coating means for coating the coating material.

[0007]

The cellulose derivative contained in the coating material used in the present invention is a general term for the compounds derived from the cellulose represented by the structural formula (Formula 1), and mainly a part or all of the hydroxyl groups of cellulose are chemically modified. It is a thing. And, as an example of the compound derived from the cellulose, there are acetyl cellulose, methyl cellulose, ethyl cellulose, benzyl cellulose, trityl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, aminoethyl cellulose, oxyethyl cellulose, etc., and the solubility is different depending on the structure. However, it is generally soluble in water.

[0008]

[Chemical 1]

Ink jet recording for generating and flying small droplets of ink by a method of applying mechanical vibration or displacement to the ink using a piezoelectric element, a method of heating the ink to foam it and utilizing its pressure, or the like. Since the main component of the ink used in the device is water, it is possible to form a coating film on the recording medium for which compatibility has been selected by coating the coating material containing the cellulose derivative as described above. Is.

In the present invention, a cellulose derivative is selected, and a coating film is formed on the recording medium with a coating material containing the cellulose derivative so that ink deposited on the coating film by ink jet recording can be removed. Swell and dissolve the coating film,
Since the ink itself penetrates into the coating film, it is possible to perform inkjet print recording without the ink flowing or bleeding regardless of the type of the substrate of the recording medium coated with the coating film.

The cellulose derivative is a very inexpensive material as is widely used as a synthetic paste and an additive when making paper from pulp, and it is possible to provide an inexpensive coating material. It is possible. As described above, the coating material for a recording medium according to the present invention is an inexpensive coating material for a recording medium that enables high-quality ink jet recording regardless of the type of the recording medium. .

[0012]

EXAMPLES Examples of the present invention will be described below, but these examples are for specifically explaining the present invention, and the embodiments are not limited thereto. (Example 1) Sodium cellulose glycolate 4.0
The weight% was gradually added to warmed ion-exchanged water 96.0% by weight, and dissolved so as not to make a joint powder to prepare a coating material.

The prepared coating material has a material viscosity of about 570 cP, and using a bar coater, a plain paper PPC-K which is a general recording paper for electrophotography, which is generally called PPC, is used. A coating gap having a thickness of 50 μm was coated on the surface of (trade name) and dried.

In this way, the recording medium coated with the coating material is subjected to single-color or multi-color recording by an ink jet recording apparatus filled with ink having the following composition. In the single-color recording, the dot diameter is confirmed and the multi-color recording is performed. Then, the amount of bleeding at the recording boundary portion with a single color and the recording density of the overlapping color recording portion were confirmed.

For comparison, plain paper PPC-K not coated with the coating material is
Single-color recording and multi-color recording were performed by the same device. The size of the opening of the nozzle orifice of the ink jet recording apparatus used in this embodiment is a square having a length of 25 μm and a width of 40 μm, and ink droplets having a diameter of about 30 to 40 μm can be ejected at one time.

(Ink Composition 1) C. I. DirectRed277 3.0 wt% Ethanol 2.5 wt% Diethylene glycol 15.0 wt% Ion-exchanged water 79.5 wt% (Ink composition 2) C.I. I. DirectYellow86 2.0% by weight Ethanol 2.5% by weight Diethylene glycol 16.0% by weight Ion-exchanged water 79.5% by weight And, single-color recording is a part recorded with magenta ink, and heavy-color recording is a superposition of yellow ink and magenta ink. The coating effect of the coating material in this example was confirmed in the recorded portion.

As a result of observing the recording portion with a microscope and measuring the diameter of the single-color dot and the amount of bleeding at the recording boundary portion between the multi-color recording and the single-color recording, all the dots were coated in the portion coated with the coating material. 80-85
The size is μm. The bleeding amount at the recording boundary portion between the heavy-color recording and the single-color recording is about several μm, which means that the bleeding is extremely small, and the coating with the coating material in this example is effective in improving the image quality. . As for the recording density in the multi-color recording, the high density recording was 1.35 as a result of measurement using a Macbeth densitometer RD920, which shows that high quality print recording was performed.

Next, as a comparison, in monochrome recording on plain paper PPC-K without coating, the dot diameter is 85.
.About.120 .mu.m, the variation in dot diameter becomes large, and the bleeding amount at the recording boundary portion between heavy-color recording and single-color recording is about 150 due to bleeding.
The image quality was deteriorated such that bleeding of up to 200 μm occurred. Regarding the recording density in multicolor recording,
As a result of measurement using a Macbeth densitometer RD920, 1.
The recording quality was as low as 17, and the recording quality including the image quality was poor. This is because wicking or bleeding, in which the recorded ink permeates along the paper surface fibers and causes bleeding, is the phenomenon that causes the most deterioration in image quality. Further, in the recording density measurement by the above-mentioned densitometer, the ink penetrates into a fibrous state and the dye molecules in the ink disperse, resulting in low density recording, which is a cause that high quality print recording cannot be expected.

As described above, it was confirmed that the coating material for a recording medium of the present invention enables stable high-quality printing without being influenced by the type of the recording medium. The coating material used in Example 1 contained 4.0% by weight of sodium cellulose glycolate, but a lower content, specifically 0.5% by weight of the coating material of the present invention. It goes without saying that the effect is recognized.

(Example 2) 8.0% by weight of methyl cellulose was gradually added to 92.0% by weight of warm ion-exchanged water and dissolved so as not to make a powder, and a coating material was prepared. did.

The prepared coating material has a material viscosity of about 300 cP, and using a bar coater, a plain paper PPC-K which is a general recording paper for electrophotography, which is generally called PPC, is used. A coating gap having a thickness of 50 μm was coated on the surface of (trade name) and dried.

In this way, the recording medium coated with the coating material is subjected to single-color or multi-color recording by an ink jet recording apparatus in which ink having the following composition is filled. Then, the amount of bleeding at the recording boundary portion with a single color and the recording density of the overlapping color recording portion were confirmed.

For comparison, plain paper PPC-K not coated with the coating material is also
Single-color recording and multi-color recording were performed by the same device. The size of the opening of the nozzle orifice of the ink jet recording apparatus used in this embodiment is a square having a length of 25 μm and a width of 40 μm, and ink droplets having a diameter of about 30 to 40 μm can be ejected at one time.

(Ink Composition 1) C. I. DirectRed277 3.0 wt% Ethanol 2.5 wt% Diethylene glycol 15.0 wt% Ion-exchanged water 79.5 wt% (Ink composition 2) C.I. I. DirectBlue 199 3.0% by weight Ethanol 2.5% by weight Diethylene glycol 15.0% by weight Ion-exchanged water 79.5% by weight And, single color recording is a part recorded with magenta ink, and heavy color recording is a superposition of magenta ink and cyan ink. The coating effect of the coating material in this example was confirmed in the recorded portion.

As a result of observing the recording portion with a microscope and measuring the diameter of the single-color dot and the amount of bleeding at the recording boundary portion between the multi-color recording and the single-color recording, in the portion coated with the coating material, all the dots were 80-85
The size is μm. The amount of bleeding at the recording boundary between heavy-color recording and single-color recording is bleeding that is extremely difficult to confirm due to the influence of paper fibers, and the coating with the coating material in this example is effective in improving image quality. It became a result. As for the recording density in the multi-color recording, the result was measured by using a Macbeth densitometer RD920, and the high density recording was 1.44, which shows that high-quality printing recording was performed.

Next, as a comparison, in monochrome recording on plain paper PPC-K without coating, the dot diameter is 85.
.About.120 .mu.m, the variation in dot diameter becomes large, and the bleeding amount at the recording boundary portion between heavy-color recording and single-color recording is about 150 due to bleeding.
The image quality was deteriorated such that bleeding of up to 200 μm occurred. Regarding the recording density in multicolor recording,
As a result of measurement using a Macbeth densitometer RD920, 1.
The recording quality was 23, which was low density, and the recording quality including the image quality was poor. This is because wicking or bleeding, in which the recorded ink permeates along the paper surface fibers and causes bleeding, is the phenomenon that causes the most deterioration in image quality. Further, in the measurement of recording density by the above-mentioned densitometer, the ink penetrates into a fibrous state and the dye molecules in the ink are dispersed, resulting in low density recording, which is a cause that high-quality print recording cannot be expected.

As described above, it was confirmed that the coating material for a recording medium of the present invention enables stable high-quality printing without being affected by the type of recording medium. The coating material used in this Example 2 contained 8.0% by weight of methylcellulose, but the effect of the present invention was recognized even with a smaller content, specifically 2.0% by weight. It goes without saying that it will be done.

(Example 3) Ethyl cellulose (15.0% by weight) was gradually added to warm ion-exchanged water (85.0% by weight) and dissolved so as not to produce a joint powder to prepare a coating material. did.

The prepared coating material has a material viscosity of about 650 cP, and using a bar coater, a plain paper PPC-K which is a general recording paper for electrophotography, which is generally called PPC, is used. A coating gap having a thickness of 50 μm was coated on the surface of (trade name) and dried.

In this way, the recording medium coated with the coating material is subjected to single-color or multi-color recording by an ink jet recording apparatus in which the ink having the following composition is filled. Then, the amount of bleeding at the recording boundary portion with a single color and the recording density of the overlapping color recording portion were confirmed.

For comparison, plain paper PPC-K not coated with the coating material is also
Single-color recording and multi-color recording were performed by the same device. The size of the opening of the nozzle orifice of the ink jet recording apparatus used in this embodiment is a square having a length of 25 μm and a width of 40 μm, and ink droplets having a diameter of about 30 to 40 μm can be ejected at one time.

(Ink Composition 1) C. I. DirectBlue199 3.0 wt% Ethanol 2.5 wt% Diethylene glycol 15.0 wt% Ion-exchanged water 79.5 wt% (Ink composition 2) C.I. I. DirectYellow86 2.0% by weight Ethanol 2.5% by weight Diethylene glycol 16.0% by weight Ion-exchanged water 79.5% by weight And, single color recording is a portion recorded with cyan ink, and heavy color recording is a superposition of yellow ink and cyan ink. The coating effect of the coating material in this example was confirmed in the recorded portion.

As a result of observing the recording portion with a microscope and measuring the diameter of the single-color dot and the amount of bleeding at the recording boundary portion between the multi-color recording and the single-color recording, in the portion coated with the coating material, all dots were 80-85
The size is μm. The amount of bleeding at the recording boundary between heavy-color recording and single-color recording was in a bleeding state that could not be confirmed, and the coating with the coating material in this example was effective in improving image quality. As for the recording density in the multi-color recording, as a result of measurement using a Macbeth densitometer RD920,
High density recording is shown at 1.35, and it can be seen that high quality print recording was performed.

Next, as a comparison, in the monochrome recording on plain paper PPC-K which is not coated, the dot diameter is 85.
.About.120 .mu.m, the variation in dot diameter becomes large, and the bleeding amount at the recording boundary portion between heavy-color recording and single-color recording is about 150 due to bleeding.
The image quality was deteriorated such that bleeding of up to 200 μm occurred. Regarding the recording density in multicolor recording,
As a result of measurement using a Macbeth densitometer RD920, 1.
The recording quality was as low as 17, and the recording quality including the image quality was poor. This is because wicking or bleeding, in which the recorded ink permeates along the paper surface fibers and causes bleeding, is the phenomenon that causes the most deterioration in image quality. Further, in the recording density measurement by the above-mentioned densitometer, the ink penetrates into a fibrous state and the dye molecules in the ink disperse, resulting in low density recording, which is a cause that high-quality print recording cannot be expected.

As described above, it was confirmed that the coating material for a recording medium of the present invention enables stable high-quality printing without being affected by the type of recording medium. The coating material used in Example 3 contained 15.0% by weight of ethyl cellulose, but the effect of the present invention was recognized even with a smaller content, specifically 1.0% by weight. It goes without saying that it will be done.

Although the bar coater is selected as the coating means in Examples 1 to 3, the present invention is not limited to this coating means, and any of various general coating means such as a micro dispenser may be used. Needless to say, the effects of the present invention are similar.

(Fourth Embodiment) A fourth embodiment of the present invention will be described with reference to FIGS. 1, 2 and 3. FIG. 1 is a perspective view showing the configuration of a recording apparatus using the present invention, and FIG. 2 is a sectional view of a recording head unit used in the recording apparatus shown in FIG. Also,
FIG. 3 shows the configuration of the recording apparatus of FIG. 1 as seen from the side.

In FIG. 1, 101 is a platen roller which rotates in the direction of arrow 107 by a motor or the like not shown, and arrow 102 shows the direction in which the recording medium 103 is moved by the platen roller. 104 is a carrier, which is carried on a shaft 105. A drive timing belt 106 is stretched between pulleys (not shown). The carrier 104 is clamped to the drive timing belt 106 by the clamp means 110 as shown in FIG. Reference numeral 111 is an ink jet recording head, and in a state where the ink supply pipe 112 is connected,
It is fixed on the carrier 104 by a fixing tool (not shown). Reference numeral 124 denotes a coating roller, which coats the recording material prepared in the coating unit 125 on the recording medium 103 in accordance with the rotation of the platen roller 101.

In FIG. 2, the piezo element 150 is vibrated,
FIG. 9 is a diagram showing a structure of a recording head unit 154 configured to eject a recording ink 152 in an ink flow path 151 from a nozzle 153 by obtaining a displacement 155. Although an ink jet recording head using a piezoelectric element is used in this embodiment, it goes without saying that the recording apparatus of the present invention is not limited to this.

FIG. 3 is a side view of the constitutional perspective view of the recording apparatus of FIG. 1, and the coating unit 125 is shown in a sectional view. 3, the same parts as those in FIG. 1 are designated by the same reference numerals. In FIG. 3, the ink jet recording head 111 includes a recording head unit and a pressure adjusting unit (not shown). Coating unit 1
In 25, sodium cellulose glycolate 7% by weight, methylcellulose 3% by weight, ion-exchanged water 90
A coating material 123 consisting of wt.% Is included. Reference numeral 122 denotes a coating material agitating / supplying roller, the coating material 123 is supplied to the coating roller 124 with an appropriate coating thickness, and is adjusted by the coating material thinning means 121 so as to have an appropriate coating thickness. Further, the coating roller 124 is adjusted so as to move up and down in the arrow direction of 120 depending on the thickness of the recording medium 103 so as to have an appropriate film thickness. The entire coating unit can be moved by pressing means (not shown), and by this movement, the coating roller 124 can control contact and contact with the recording medium 103. Further, the surface of the coating material coated on the recording medium 103 is adjusted by the blade 300 in order to make the surface state smooth and uniform.

The operation of the printer, which is a recording apparatus using the present invention having the above configuration, will be described with reference to FIGS. 1 and 3. The recording medium 103 is a platen roller 10.
The recording medium is wound around the recording medium 1 and is set in a state in which recording can be easily performed by a recording medium pressing mechanism (not shown). And
By rotating the platen roller 101, the recording medium 103 is carried out in the direction of arrow 102. First, when the tip of the recording medium 103 wound around the platen roller 101 is rotated to the position of the coating roller 124, the coating unit 125 is pressed against the platen roller 101 by a pressing unit (not shown), and the recording medium by the coating roller 124 is pressed. The coating of 103 is started. In the coated recording medium 103, the platen roller 101 has an arrow 107.
Since it rotates in the direction, the surface state of the recording medium 103 coated by the installed blade 300 is adjusted smoothly and uniformly. Next, inkjet recording is performed on the coating film at the position of the inkjet recording head 111. The carrier 104 is stopped at the position of one end of the platen roller before recording is started.

When recording is next started, a pulley (not shown) rotates, the drive timing belt 106 associated with the pulley causes the carrier 104 to reciprocate on the shaft 105 in the main scan, and the platen roller 101 moves to the position shown in FIG. The sub-scanning movement is made in the direction of arrow 107 in FIG. At this time, when a recording signal is input to the recording head 111, ink particles are ejected from the recording head 111, and the ink particles adhere to the coating film on the recording medium 103 to perform recording. In this way, the main scan by the reciprocating movement of the carrier 104 and the sub-scan by the rotation of the platen roller 101 are repeated, and thus the recording medium 1
03 coating and ink jet recording.

Regarding the recording ink used for ink jet recording, single color or multi-color recording is carried out by an ink jet recording apparatus filled with ink of the following composition, the dot diameter is confirmed in single-color recording, and in multi-color recording. The amount of bleeding at the recording boundary portion with a single color and the recording density of the overlapping color recording portion were confirmed.

For comparison, plain paper PPC-K which is not coated with the coating material,
Single-color recording and multi-color recording were performed by the same device. The size of the opening of the nozzle orifice of the ink jet recording apparatus used in this embodiment is a square having a length of 25 μm and a width of 40 μm, and ink droplets having a diameter of about 30 to 40 μm can be ejected at one time.

(Ink Composition 1) C. I. DirectRed9 3.0 wt% Diethylene glycol 15.0 wt% Carbitol 2.5 wt% Ion-exchanged water 79.5 wt% (Ink composition 2) C.I. I. DirectYellow86 2.5% by weight Diethylene glycol 16.0% by weight Carbitol 2.5% by weight Ion-exchanged water 79.0% by weight Then, single-color recording is a portion recorded with magenta ink, and heavy-color recording is a superposition of yellow ink and magenta ink. The coating effect of the coating material in this example was confirmed in the portion where the recording was performed.

The recorded portion was observed under a microscope to measure the diameter of the single-color dot and the amount of bleeding at the recording boundary between the multi-color recording and the single-color recording. As a result, in the portion coated with the coating material, all dots were 82-86
The size is μm. The bleeding amount at the recording boundary portion between the heavy-color recording and the single-color recording is about several μm, which means that the bleeding is extremely small, and the coating with the coating material in this example is effective in improving the image quality. . As for the recording density in the multi-color recording, the result was measured using a Macbeth densitometer RD920, which showed high density recording of 1.30, which shows that high-quality print recording was performed.

Next, for comparison, in monochrome recording on plain paper PPC-K without coating, the dot diameter is 86.
In addition to the large dot diameter variation of up to 125 μm, the bleeding amount at the recording boundary between heavy-color recording and single-color recording is about 150 due to bleeding.
The image quality was deteriorated such that bleeding of up to 200 μm occurred. Regarding the recording density in multicolor recording,
As a result of measurement using a Macbeth densitometer RD920, 1.
The recording quality was as low as 17, and the recording quality including the image quality was poor. This is because wicking or bleeding, in which the recorded ink permeates along the paper surface fibers and causes bleeding, is the phenomenon that causes the most deterioration in image quality. Further, in the recording density measurement by the above-described densitometer, the dye molecules in the ink are dispersed because the ink permeates into a fibrous state, resulting in low density recording, which makes high quality print recording impossible.
From this result as well, it was confirmed that the coating material for the recording medium and the recording apparatus of the present invention enabled stable high-quality printing without being affected by the type of the recording medium.

It is needless to say that other than the coating material or the recording ink shown in the present embodiment, it is possible to appropriately use other inks within the scope of the present invention. It goes without saying that the same applies to the recording apparatus used.

[0049]

As is apparent from the above description, in the present invention, a recording medium used for ink jet recording,
By including a cellulose derivative in a coating material that is applied before ink is applied by inkjet recording, high image quality, high recording density, and color reproducibility in multicolor recording can be achieved regardless of the type of recording medium used. It is possible to provide a coating material for a recording medium and a recording device that enable high-quality inkjet recording with good quality.

[0050]

[Brief description of drawings]

[0051]

FIG. 1 is a configuration perspective view of a recording apparatus according to a fourth embodiment of the present invention.

[0052]

FIG. 2 is a cross-sectional view of the inkjet recording head used in the above-described example.

[0053]

FIG. 3 is a configuration diagram of a recording apparatus according to an exemplary embodiment of the present invention as viewed from a side surface.

[0054]

[Explanation of symbols]

 101 Platen Roller 103 Recording Medium 104 Carrier 105 Shaft 106 Drive Timing Belt 111 Inkjet Recording Head 112 Ink Supply Pipe 120-125 Coating Means 300 Blade

[0055]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayoshi Shiraishi 6-31-1, Kameido, Koto-ku, Tokyo Seiko Electronics Industry Co., Ltd.

Claims (3)

[Claims] 1. A coating material for a recording medium used for inkjet recording, which comprises a cellulose derivative in a coating material used for coating before the ink is adhered by inkjet recording. material. 2. The content of the cellulose derivative is 0.5.
The coating material for a recording medium according to claim 1, wherein the coating material is 15% to 15%. 3. In an inkjet type recording apparatus for recording an image on a recording medium by ejecting recording ink from an inkjet recording head in response to a recording signal, recording with the recording ink is performed on the recording medium. Prior to the above, a recording device is provided with a coating means for coating the recording medium with the coating material according to claim 1 or 2.