JP3155656B2 - Recording paper and image forming method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording paper, and more particularly, to a so-called plain paper type which can be used in both an ink jet recording apparatus and an electrophotographic recording apparatus and has no special coating on the recording surface. Recording paper and an image forming method using the recording paper.

[0002]

2. Description of the Related Art An ink jet recording system is a system in which ink is directly ejected onto a recording sheet, and has attracted attention as a recording method which is lower in running cost than conventional recording apparatuses, quiet and easy in color recording. Ink used in such a recording method is water-based ink from the viewpoint of safety and printing characteristics, and the recording material has a rapid absorption of the ink into the recording material and has a different color ink. That ink does not overflow, that the ink dots spread properly, that the dot shape is close to a perfect circle,
Further, it is required that the dot edge is clear, and naturally, the dot density is high and the whiteness is sufficiently high to make the dot contrast stand out.

On the other hand, a recording sheet used in an electrophotographic recording apparatus has an appropriate surface electric resistance and surface smoothness, has good toner transferability, and has good toner fixability. It is required that the generation of paper dust is small, that the generated paper dust adheres to the photoreceptor and the charging roller, and that no image defects occur, and that the recording paper does not cause poor suction on the transfer drum. I have.

As the recording paper for the ink jet recording, for example, Japanese Patent Application Laid-Open No.
It has been proposed to use a special coated paper as disclosed in JP-A-9-35977 and JP-A-1-135682. On the other hand, in the field of monochrome recording and business color recording, it is desired to use low-cost and versatile recording paper, that is, plain paper generally used in the field of electrophotographic recording. On the other hand, as recording paper for electrophotographic recording devices, recently, neutral paper has been used in place of conventional acidic paper due to problems such as paper storability,
For example, JP-A-51-13244, JP-A-59-13244
Japanese Patent Publication No. 162561 and Japanese Patent Publication No. 2-54543 propose a neutral toner transfer sheet having excellent electrophotographic recording characteristics.

[0005]

However, when the conventional plain paper for electrophotographic recording is used in the ink jet recording system, the ink absorbency is poor, and when a large amount of ink is applied, the overflow of the ink or the like may occur. There is a problem that the ink dots are absorbed, and the ink is absorbed along the fibers of the paper. As a means for solving these problems, the present applicant has reduced the amount of high boiling organic solvent previously contained in the ink for the purpose of preventing clogging due to drying of the recording nozzles, and assisted in dissolving the dye. An ink-jet recording system using ammonia, urea and its derivatives, amino alcohols, alkylamines, amino acids and the like as an agent and internally added to recording paper for recording using this ink has been proposed.

In recent years, when toner transfer paper of neutral paper, which is becoming mainstream as plain paper for electrophotographic recording, is used as recording paper of an ink jet recording system, a black ink used in ink jet recording has an image called bronze. However, in the ink jet recording method using the above-mentioned ink containing a nitrogen compound, there is a problem that bronzing is more conspicuous. Such neutral paper also suppresses the generation of paper dust and uneven image density, and also reduces the wear of the photoconductors, fixing rollers, and paper transport rollers such as paper feed, especially for use in electrophotographic recording. There has not yet been obtained a printer which sufficiently satisfies the characteristics of a copying machine, such as preventing defective adsorption on a transfer drum. In such a situation, the ink jet recording method has become widespread due to the excellent characteristics of the ink jet recording method, and the demand for recording paper that can be used in common for both the electrophotographic recording method and the ink jet recording method has become very large. ing. Therefore, the object of the present invention is to
It is an object of the present invention to provide a so-called plain paper type recording sheet which can be used in both an ink jet recording apparatus and an electrophotographic recording apparatus, and in particular, has no special coating on a recording surface, and an image forming method using the recording sheet. .

[0007]

The above object is achieved by the present invention described below. That is, the present invention is a recording paper based on a neutral paper prescription, a substance that adsorbs ammonia or ammonium ions generated due to a nitrogen compound in the liquid ink is internally added, and, on each of both surfaces , Lee <br/> as penetration retarder for delaying the penetration of ink, casein,
Starch, carboxymethylcellulose, hydroxyethyl
Cellulose, polyvinyl alcohol, polyvinylpyrroli
Don, sodium polyacrylate, polyacrylamide, S
BR latex, acrylic emulsion, styrene / male
Maleic acid copolymer, styrene / acrylic acid copolymer, silicone
Recon oil, paraffin, wax and fluorine compounds
Jet recording and an electronic copy characterized by containing the one selected at the rate of 2.5~5g / m ² from
A recording sheet for true recording and an image forming method using the recording sheet.

[0008]

[Action] neutral paper formulated recording paper based, a substance which adsorbs ammonia or ammonium ions caused by the nitrogen compound in the liquid ink is internally added, and on both sides of the respective penetration of the upper Symbol ink The so-called plain paper type, which can be used in both an ink jet recording apparatus and an electrophotographic recording apparatus, by containing a specific permeation retarder at 2.5 to 5 g / m ² which delays Recording paper can be provided.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in more detail with reference to preferred embodiments. The recording paper that can be used in the present invention is mainly made of chemical pulp represented by LBKP and NBKP, a sizing agent and a filler, and is made by a conventional method using other papermaking aids as required. As the pulp material used for the recording paper of the present invention, mechanical pulp or recycled pulp may be used in combination, or there is no problem even if these are used as the main material.

The sizing agent internally added to the recording paper includes, for example, rosin size, AKD, alnickel succinic anhydride, petroleum resin type size, epichlorohydrin, cationic starch, acrylamide and the like. However, when the recording paper used in the electrophotographic recording apparatus is a sheet having a small surface free tension of the sizing agent, the fixing property of the toner resin used in the recording apparatus may be impaired. What is necessary is just to select suitably according to a toner.

A first feature of the present invention is that a recording paper based on the above neutral paper prescription contains a substance which adsorbs ammonia or ammonium ions generated by a nitrogen compound in ink used for ink jet recording. That is the point. Examples of such adsorbents include finely divided silica,
Fillers such as aluminum silicate, diatomaceous earth, kaolin, kaolinite, halloysite, nacrite, dickite, pyrophyllite, sericite, titanium dioxide, bentonite, activated clay, etc .; homopolymers of monomers such as acrylic acid or methacrylic acid, or others Copolymers with common monomers, maleic acid, homopolymers of α, β unsaturated acids such as methacrylic acid or copolymers with other common monomers,
Polymers having sulfonic acid groups, esters of polycarboxylic acids and polyhydric alcohols, acidic cellulose derivatives modified with polycarboxylic acids or polymers of these alkali metal salts such as sodium and potassium; sodium lauryl sulfate, cetyl Sodium sulfate, sodium polyoxyethylene lauryl ether sulfate, sodium lauryl phosphate, sodium polyoxyethylene lauryl ether phosphate, alkylbenzenesulfonic acid, surfactants such as salts such as alkylsulfosuccinic acid, and the like. Preferred materials are synthetic aluminum silicate or kaolin minerals.

[0012] The maximum feature of the present invention, in addition to the internal addition of the adsorbent material, on both sides of the recording paper, the specific permeation retardant to delay the penetration of the upper SL ink 2.5~5g / m That is, it was contained at a ratio of ² . By doing the above,
The ink adhering to the recording paper surface of the present invention delays permeation into the paper layer by about 0.01 seconds to several seconds due to the action of the permeation retarder, and most of the low boiling solvent such as water on the recording paper surface. After evaporating, it penetrates into the paper layer. By this effect, the ink does not bleed more than necessary, and the dye stays near the recording surface, so that a dot with high contrast is formed.

[0013] As penetration retardants granting the recording surface of the recording sheet of the present invention, casein, starch, carboxymethyl cellulose, hydroxyethyl cell row scan, polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate, polyacrylamide, S BR latex, acrylic emulsion, styrene / maleic acid copolymer, styrene / acrylic acid copolymer, divorced oil, paraffin, compounds der selected from waxes and fluorine compounds
You.

These materials are used on both sides of the recording paper so that problems such as uneven transfer of toner and damage to the photoreceptor do not occur even when used for double-sided copying in a recording apparatus of an electrophotographic recording system. Apply. In order to prevent the permeation retarder applied to both sides of the recording paper during image formation from adhering to and fusing to the surface of the photoreceptor, image density unevenness and dot-like image quality deterioration do not occur. It is coated and contained at a rate of 5 to 5 g / m ² . If within the above range, even if the recording paper is used in an ink jet recording system, the effect of delaying the penetration of the ink is maintained, and the ink that is the evaporation residue containing a nonvolatile solvent such as a polyhydric alcohol is Since the ink permeates and is absorbed in the paper layer, the ink fixing property does not extremely decrease.

The recording paper of the present invention is adjusted to have a water extraction pH of 6 or more, preferably 7 or more. The water extraction pH is obtained by measuring the pH of an extract obtained by immersing about 1.0 g of a test piece specified in JIS-P-8133 in 7 ml of distilled water in accordance with JIS-Z-8802. p
When H is less than the above range, not only does the long-term storability of the recording paper itself deteriorate, but also the dye in the ink does not show sufficient coloring properties.

If the recording paper size adjusted in this manner is too low, the attached ink will be too bleeding, and clear images and characters will not be easily formed.
If it is too high, the ink will not be absorbed into the paper layer for a long time, and the fixing and drying properties of the attached ink will decrease. Therefore, in the recording paper of the present invention, it is desired that the Steckigt sizing degree is in the range of 16 to 40 seconds.

As described above, since the edges are sharp and uniform, the ink has an appropriate ink bleeding on the recording paper surface, and dots of high density are formed (images of good print quality are formed). As a configuration of both the ink and the recording paper, the ink droplets adhering to the recording surface are not instantaneously absorbed into the paper layer, and after the evaporation of the ink solvent on the recording paper surface is completed to some extent, Desirably, it is absorbed in the paper layer.

In the present invention, since the recording paper contains a substance that adsorbs ammonia and ammonium ions generated from a nitrogen compound in the ink, the ink jet recording method using an ink containing a nitrogen compound and neutral paper is particularly useful. An ink jet recording sheet having good printing quality and no bronzing while maintaining advantages is provided. Further, since the recording paper of the present invention does not involve a significant change in the surface shape and physical characteristics other than the recording characteristics even when compared with the conventional neutral PPC paper, the toner transfer recording paper for electrophotographic recording and the ink jet recording Applicable to both types of paper.

As described above, the ink used in the ink jet recording method of the present invention contains water as a main component, an organic solvent such as a polyhydric alcohol, a dye as a recording agent, a nitrogen compound as a dye dissolution aid, The composition further contains other additives as necessary. As the dye itself used in the ink, a conventionally known acid dye or direct dye can be used.

The ink-jet recording system using the recording paper of the present invention is any of the conventionally known ink-jet recording systems in which small ink droplets are ejected from nozzles to perform recording by utilizing various driving principles. Is also applicable. Above all, the present invention is disclosed in
The ink which has been subjected to the action of thermal energy by the method described in JP-A-36-36 causes a sudden change in volume, and can be used particularly effectively in an ink jet recording system in which ink is ejected from nozzles by the action force due to this state change.

The electrophotographic recording system using the recording paper of the present invention is well known, and an example of the apparatus is shown in FIGS. 1 and 2. FIG. First, as shown in FIG. 1, a photoconductor 3 having photoconductive properties is charged by a primary charger 5 and then exposed to form an electrostatic latent image, which is held in a developing device 6 as a developing means. The above-described electrostatic latent image is developed using the toner 8 of the developer in the two-component or two-component developer to form a toner image, and then a transfer charger as a transfer unit on the recording paper 4 of the present invention that has been separately conveyed. 7, the toner image on the photoconductor is transferred. Subsequently, as described above, the image is transferred by a fixing device 12 as a fixing unit including two rollers 9 and a roller 10 (or one roller and one belt) shown in FIG. 2 by the action of heat, pressure, or both. The obtained toner image is fixed on the recording paper 4 to obtain a final copied image.

Recording paper 4 generated in the transfer step
The unfixed toner and paper dust generated from the recording paper 4
Removed by the cleaner unit 1 arranged in the transfer process,
The photoconductor 3 is cleaned. After the surface of the photoconductor is cleaned by the cleaning member 2 (for example, a cleaning blade) in contact with the photoconductor 3, a process such as charging is repeated again. Further, as shown in FIG. 2, unfixed toner and paper dust generated from the recording paper 4 in the fixing device 12 are removed by the cleaning member 11 abutted on the fixing roller 9.
And a release agent such as silicone oil is applied to the fixing roller 9. The above-described example describes one example of a method of forming an image using the recording paper of the present invention in an electrophotographic recording system, and the recording paper of the present invention may be any other known electrophotographic recording apparatus. Of course, it can also be used.

[0023]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following, "parts" and "%" are based on weight unless otherwise specified. (Preparation of recording paper) After mixing 90 parts of LBKP and 10 parts of NBKP as a raw material pulp and beaten, kaolin (made by Tsuchiya Kaolin) 10
Parts, 0.2 parts of alkenyl succinic anhydride and 0.5 parts of cationized starch were mixed to obtain recording paper having a basis weight of 70 g / m ² and a Steckigt sizing degree of 23 seconds by a conventional method. For this recording paper, a permeation retardant solution (concentration: 2%) having the following composition was prepared as a surface sizing agent, and this was applied to each side of the recording paper by air spray within a range of 1 to 6 g / m ² . The recording paper of the present invention and the comparative example were prepared by changing the coating amount and coating on both sides. Solid composition of permeation retardant solution: oxidized starch (MS-3800, manufactured by Nippon Shokuhin) 95 parts Styrene / maleic acid copolymer (Oxylac, manufactured by Nippon Shokubai Chemical) 5 parts

(1) Evaluation by Electrophotographic Recording Apparatus Each of the recording sheets obtained above was passed through 100,000 sheets and 10,000 sheets, respectively, using a copying machine FC-5 manufactured by Canon Inc. as an electrophotographic recording apparatus. , Transfer unevenness, photoreceptor scratches, cleaning properties, filming properties and drum fusion were evaluated according to the following criteria, and the results shown in Table 1 below were obtained.

Evaluation items (a) Transfer unevenness: x: level at which image density unevenness due to transfer unevenness can be clearly recognized visually. Δ: level at which image density unevenness due to transfer unevenness can be slightly visually recognized. …: Level at which image density unevenness due to transfer unevenness cannot be visually recognized. (B) Scratches on the photoreceptor: ×: A level at which the surface of the photoreceptor is scratched by a visual check and an image defect occurs. Δ: a level at which the surface of the photoreceptor is scratched by a visual check but does not appear in the image. …: A level at which the surface of the photoreceptor is scarcely damaged by a visual check. (C) Cleaning performance: x: A level at which residual toner due to poor cleaning remains on the surface of the photoreceptor, resulting in defective images. Δ: A level at which residual toner due to poor cleaning remains on the surface of the photoreceptor but does not appear in an image. …: Level at which residual toner due to poor cleaning does not remain on the surface of the photoconductor. (D) Filming property x: A level at which a surface sizing agent adheres to the surface of the photoreceptor and image density unevenness occurs. Δ: A level at which the surface sizing agent adheres to the surface of the photoreceptor, but image density unevenness cannot be visually recognized. …: The level at which the surface sizing agent does not adhere to the photoconductor surface. (E) Attachment of the drum ×: The level at which the surface sizing agent adheres to the surface of the photoreceptor and image deterioration occurs. Δ: A level at which the surface sizing agent adheres to the surface of the photoreceptor but does not appear on the image. …: The level at which the surface sizing agent does not adhere to the photoconductor surface.

(2) Evaluation by Inkjet Recording Apparatus In the evaluation, inks having the following compositions were used. Dye 3 parts Diethylene glycol 5 parts Ethanol 5 parts Urea 5 parts Water 82 parts

Using the recording papers and inks obtained above, an ink jet recording apparatus CJ-10 manufactured by Canon Inc.
And recording suitability was evaluated. Table 1 shows the results.

(Evaluation items) (a) Print quality A straight line having a width of 1 dot is printed in parallel with the scanning direction of the head.
The evaluation was made visually from a distance of 25 cm. Straight edges are opaque and blurred, feathering is noticeable,
The level at which dot bleeding occurred and was unacceptable visually was rated as x, and the level at which a clear straight line was visible and dot bleeding was not visually recognizable was rated as o. Although feathering occurred, it was light and practically acceptable, and slight dot bleeding occurred.

(B) Bronze Solid printing was performed on the entire surface of the recording paper using the recording apparatus described above.
When the printed portion was recognizable as black, it was rated as ○, and when bronze was generated and a brown magenta pattern was seen, it was rated as x. Also, some bronzes are generated, but are acceptable in practice.
And Table 1 shows the evaluation results.

[0030]

[Table 1] Table 1 Evaluation results

[0031]

As described above, according to the present invention, there is provided a neutral plain paper for both ink jet recording and electrophotographic recording wherein uniform images can be obtained without uneven absorption of ink and uneven transfer of toner. An image forming method using a recording sheet is provided.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating copying by an electrophotographic recording method.

FIG. 2 is a diagram illustrating a fixing process in an electrophotographic recording method.

[Description of Signs] 1: Cleaner section 2: Cleaning member 3: Photoconductor 4: Recording paper 5: Primary charger 6: Developing device 7: Transfer charger 8: Toner 9, 10: Roller 11: Cleaning member 12: Fixing vessel

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akio Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Mamoru Sakaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Masato Katayama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masayoshi Takahashi 3-30-2, Shimomaruko 3-chome, Ota-ku, Tokyo Canon Inc. ( 56) References JP-A-5-177921 (JP, A) JP-A-5-221113 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/00 D21H 19/10 G03G 7/00 101

Claims (3)

(57) [Claims] 1. A recording paper based on a neutral paper prescription, wherein a substance which adsorbs ammonia or ammonium ions generated by a nitrogen compound in a liquid ink is internally added, and a Casein, starch, carboxymethyl
Cellulose, hydroxyethyl cellulose, polyvinyl
Alcohol, polyvinylpyrrolidone, polyacrylic acid
, Polyacrylamide, SBR latex, acrylic
Emulsion, styrene / maleic acid copolymer, styrene
Len / acrylic acid copolymer, silicone oil, paraffin
One selected from the group consisting of waxes, waxes and fluorine compounds .
Characterized in that it is contained at a ratio of 5 to 5 g / m ^2.
Recording paper for inkjet recording and electrophotographic recording. 2. A recording image on a recording sheet according to claim 1, wherein a small droplet of an ink containing a nitrogen compound is ejected from an orifice of a recording head and adhered to the recording sheet according to a recording signal. Forming an image by an inkjet recording method. 3. A toner image formed on a photoreceptor is electrostatically transferred to the recording sheet according to claim 1, and the toner image transferred on the recording sheet is heated and / or pressured. An image forming method using an electrophotographic recording method, wherein a recording image is formed by adding and fixing a recording medium.