JPH05221113A - Recording paper - Google Patents

Abstract

PURPOSE:To provide excellent recording paper having good toner fixation as electrophotographic transfer paper, and also having quick ink absorptivity, high printing density, and ink-run preventability as ink-jet recording paper employing water-color ink. CONSTITUTION:The recording paper is featured such that the original paper contains calcium carbonate and a cationic sizing agent in each of the filler and inner sizing agent, and the steckigt sizing degree is 2-15sec., and the cationic sizing agent consists of a copolymer of stylene or its derivative and acrylic acid or ester of methacrylic acid, and the surface of the original paper is applied with a surface sizing liquid containing a surface sizing agent and water soluble polymer. Herein, the recording paper represents excellent toner fixation as electrophotographic transfer paper, and also represents quick ink absorptive speed, good dot shape and high printing density as ink-jet recording paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to recording paper. Especially for inkjet printers that use water-based ink, excellent dot shape, high print density,
The present invention relates to a recording paper which exhibits a rapid ink absorbability and is excellent in toner fixing property, transfer property and workability as an electrophotographic transfer paper.

[0002]

2. Description of the Related Art In recent years, the number of cases where electrophotographic transfer paper or the like is manufactured in a neutral region by using calcium carbonate has been increasing for the purpose of improving whiteness and opacity and improving the storage stability of paper.

When paper is produced in the neutral range, a neutral sizing agent is used instead, since a rosin sizing agent that can perform in an acidic atmosphere and in the presence of a sulfuric acid band cannot be used.

Here, as the neutral sizing agent, an aqueous dispersion of an alkyl ketene dimer (hereinafter abbreviated as AKD) is most preferable because it is easy to handle or excellent sizing property can be obtained by adding a small amount. Many are used.

When AKD or alkenyl succinic anhydride (hereinafter abbreviated as ASA) is used as a sizing agent on a recording paper, if the sizing agent is added in order to obtain a high sizing degree, the paper cannot be used. The surface energy of the toner tends to decrease, and the fixability of the toner transferred to the paper by an electrophotographic copying machine tends to deteriorate.

As measures for improving the toner fixing property, reduction of the amount of AKD or ASA added and increase of the amount of starch applied to the surface size solution have been attempted.

For strong size paper using AKD or ASA,
When printing with an inkjet printer, the dot size is small and the shape is close to a perfect circle, so resolution and print density are high, but the ink absorption speed is slow and stains when overwriting with a line marker pose a problem. That is, it is not satisfactory as an inkjet recording paper.

As a means for improving the printing quality of ink jet recording paper, JP-A-1-165574 discloses that a styrene-acrylic acid copolymer is applied to a base paper containing 16% ash content in the paper to obtain a Steckigt sizing degree. 10
There is a method to use paper for more than a second. Furthermore, JP-A-3-133
Japanese Patent No. 685 discloses, as a conventional technique, a method of coating silica having a large oil absorption amount on the surface of paper in order to increase the resolution and the ink absorption speed.

[0009]

Techniques applicable to obtain excellent toner fixing properties as electrophotographic transfer paper include reduction of the amount of AKD and ASA added as described above, and coating of starch in surface size treatment. There are ways to increase the amount.

The above-mentioned internally added sizing agent (AKD or ASA)
From the characteristics of inkjet recording paper, the method of reducing the addition amount of is that the absorption speed of the water-based ink becomes faster,
The bleeding of the water-based ink increases and the resolution decreases.

Further, when the amount of the internally added sizing agent (AKD or ASA) is reduced, the aqueous ink permeates into the inside of the base paper layer, and as a result, the printing density becomes low and sufficient printing quality cannot be obtained. ..

That is, an object of the present invention is to provide a recording paper which has excellent toner fixing property when used as a transfer paper for electrophotography and sufficient printing quality when used as an ink jet recording paper. To do.

[0013]

The inventors of the present invention have made diligent efforts to solve the above-mentioned problems, and as a result, have a Steckigt sizing degree of 2 to 15 containing calcium carbonate as a filler and a cationic sizing agent as an internal sizing agent. Second base paper, wherein the cationic sizing agent is composed of a copolymer of styrene or a derivative thereof and an ester of acrylic acid or methacrylic acid, and the surface sizing agent and the water-soluble polymer on the surface of the base paper. It has been found that a recording paper having the necessary properties as a transfer paper for electrophotography or an inkjet recording paper can be obtained by applying a surface size liquid consisting of

As the ink jet recording paper or the electrophotographic transfer paper, it is necessary to satisfy the following characteristic conditions. 1. Toner fixability. 2. Prompt absorption of water-based ink. 3. Water-based ink does not bleed (dot shape close to a perfect circle). 4. Print density is high. 5. No stain after overwriting with line marker.

The fixability of the toner depends on the type and amount of the internally added sizing agent. When AKD or ASA which is generally used is used, the toner fixing property tends to be deteriorated when the addition amount is large.

Further, AKD and ASA have a high sizing degree with a small amount of addition, and it is very difficult to control the sizing degree at a low sizing degree.

However, when a cationic sizing agent is used as an internally added sizing agent, control at a low sizing degree is relatively easy. Even if the amount of addition is large, the problem of deterioration of toner fixing property does not occur.

The above characteristics 2 to 5 are basically closely related to the size of the paper.

If the amount of the cationic internal sizing agent added is small, for example, if the Steckigt sizing degree is less than 2 seconds, the water-based ink will bleed to increase the dot diameter, resulting in a reduction in resolution and print density.

The amount of the cationic internal sizing agent added increases,
As the size of the base paper increases, the dot diameter decreases and the print density increases. However, the Steckigt size degree is 1
If it exceeds 5 seconds, the ink absorption speed will slow down,
Pen writing stains occur when using line markers.

Oxidized starch, PVA or modified PV for controlling absorption, bleeding and print density of water-based ink
It is effective to apply a water-soluble polymer such as A as a surface size.

By coating a water-soluble polymer on the paper surface, the coating layer functions as an ink absorbing layer, and the rate and amount of water-based ink absorbed by the base paper layer can be controlled. Further, it is possible to prevent the ink from bleeding along the capillaries between the fibers and the deterioration of the dot shape.

The coating amount of the water-soluble polymer is 0.5 g / m ^2.
If it is less than the above, it does not function as an absorption layer. Also, 3.0 g / m ²
Even if it exceeds, improvement cannot be expected. Further, when used as a transfer paper for electrophotography, curling occurs, which causes troubles such as paper jams, and a coating amount of 0.5 to 3.0 g / m ² is desirable.

As the water-soluble polymer, it is preferable to use at least one of modified starch, polyvinyl alcohol or a derivative thereof obtained by subjecting starch to an oxidation treatment or a phosphoric acid esterification treatment according to the purpose.

Further, in order to easily control the absorption rate of the water-based ink, the dot diameter and the dot shape, a surface sizing agent is added to the water-soluble polymer, and the surface of the base paper is made 0.0%.
It is preferable to apply it in an amount of 05 to 0.05 g / m ² .

The coating amount of the surface sizing agent is 0.005 g /
If it is less than m ² , the absorption rate of the water-based ink cannot be controlled, and if it exceeds 0.05 g / m ² , the absorption rate of the water-based ink will be slow and smearing with a pen will occur.

There is also a method of reducing the amount of the internally added sizing agent and the surface sizing agent in order to improve the smearing with the pen.
In this method, the print density decreases as the stain on the pen is improved.

A method of using a penetrating agent is also effective for improving pen writing stains while maintaining a high print density.
The print density may decrease.

As described above, by applying the surface sizing agent and the water-soluble polymer to a base paper containing a cationic sizing agent and having a Steckigt size of 2 to 15 seconds, an ink jet recording paper or a paper is prepared. It was found that the recording paper has sufficient characteristics as an electrophotographic paper, thus completing the present invention.

The reason for this is that the use of a cationic sizing agent as the internal sizing agent does not lower the surface energy and does not deteriorate the toner fixing property, and also the penetrating agent and the surface sizing agent. Also, by applying a surface-size liquid containing a water-soluble polymer, it is possible to increase the printing density even if the water-soluble ink has a high absorption speed, and it is considered that the characteristics as an inkjet recording paper are obtained. ..

The electrophotographic transfer paper in the present invention refers to a transfer electrophotographic (xerographic) copying machine, a page printer, a continuous printer to which this method is applied, a facsimile, a full-color copying machine, and the like. Is what is used.

The ink jet recording paper in the present invention is a recording paper used in drop-on-demand type or continuous type printers and facsimiles using water-soluble ink.

The pulp used in the base paper of the present invention includes NBKP, LBKP, NBSP, LBSP, GP,
Examples include TMP and waste paper. Upon use, they are mixed in several types at a ratio according to the purpose.

The surface sizing agent used in the present invention is
Styrene-acrylic acid, which is commonly used for neutral paper,
Among the polymers of olefin-maleic acid, acrylic acid, styrene-maleic acid and the like, among them, styrene-acrylic copolymers and styrene-maleic acid copolymers are effective. For example, it is a surface sizing agent containing as a main component a copolymer of styrene and acrylic acid as described in JP-A-55-99909 and JP-A-57-24363.

As the water-soluble polymer used in the present invention,
Oxidized starch, phosphate esterified starch, cationized starch, self-modified starch and various modified starches, polyethylene oxide,
Polyacrylamide, sodium polyacrylate, sodium alginate, hydroxyethylethyl cellulose, methyl cellulose, polyvinyl alcohol or derivatives thereof are used. Further, these water-soluble polymers can be used as a mixture of several kinds depending on the purpose.

The recording paper of the present invention optionally contains a filler such as a dye, talc, kaolin titanium oxide, etc., a sizing agent, a fixing agent, a dry paper strengthening agent, etc., which are usually used in the papermaking process. Is.

The surface sizing liquid of the present invention is used on the surface of a base paper for various blades, rods and air knives such as size press, gaiter coater, bill blade coater, blade metalling size press, bell vapa coater and short dwell coater. It is possible to apply with a curtain coater.

[0037]

EXAMPLES The present invention will be described in detail below with reference to examples. The present invention is not limited to the embodiments. All parts and percentages below are by weight. The value indicating the smear amount is the weight after drying, unless otherwise specified.

First, a cationic sizing agent comprising a copolymer of styrene and an ester of acrylic acid was prepared.

Preparation Example 1 Capacity 300 cc equipped with reflux condenser and rubbing agitator
Into the four-necked Kolben, 13.9 g of styrene, 6.1 g of 2-ethylhexyl-acrylate, 11.8 g of acrylamide and 6.2 cc of 1,4-dioxane were charged, and 320 cc of azoisobutyronitrile was used as a polymerization catalyst.
After the addition, polymerization was carried out in a nitrogen stream at a temperature of 70 ° C. for 6 hours. After completion of the polymerization, 5 more 1,4-dioxane was added.
0 cc, dimethylamine 40% aqueous solution 19.1 cc,
Add 20.7 cc of formalin 37% aqueous solution, 70 ℃
The reaction is carried out at the temperature of 5 hours. The resin concentration after the reaction is
It was 19.2%. 50 g of this resin solution was collected in a 100 cc beaker, and dimethylsulfate 6.3 was added under ice cooling and stirring.
A mixed solution of g and 10 cc of 1,4-dioxane was added dropwise for 30 minutes, and stirring was continued for another 30 minutes. Then, 3 cc of acetic acid
Was added for neutralization to obtain a transparent solution.

Example 1 Freeness of 380 ml c.p.m. s. f. LBKP beaten up to 450 ml c. s. f. N beat up
Pulp 10 in which BKP is mixed in a weight ratio of 7: 3
To 0 parts, 7 parts of light calcium carbonate (TP121, manufactured by Okutama Kogyo Co., Ltd.), 0.3 parts of the cationic sizing agent of Preparation Example 1 as a solid component, amphoteric starch (Kate 321)
0, made by Oji National Co., Ltd.), 0.8 part is added, and the basis weight is 64
A handsheet of g / m ² was prepared. The sheet was dried at 90 ° C. for 5 minutes. Then, a styrene acrylic surface sizing agent (trade name KN500, manufactured by Harima Kasei Co., Ltd.) was applied to these sheets together with the oxidized starch in a size press at an amount of 0.03 g / m ² , and the oxidized starch (trade name MS3800, Japan). (Food Processing Co., Ltd.) so that the coating amount is 1.5 g / m ² and the temperature is 90 ° C.
After drying for a minute, machine calendar processing was performed to prepare recording paper.

Example 2 The amount of the cationic sizing agent used in Example 1 was changed to
A recording sheet was prepared in the same manner as in Example 1 except that 0.4 parts was used.

Example 3 The same method as in Example 1 except that the surface sizing agent used in Example 1 was replaced with a styrene-maleic acid type surface sizing agent (trade name: Hamacoat AK600, manufactured by Misawa Ceramic Chemical Co.). To prepare a recording sheet.

Example 4 The surface sizing agent used in Example 1 was an olefin surface sizing agent (trade name: Polymaron 482S, manufactured by Arakawa Chemical Co., Ltd.).
A recording sheet was prepared in the same manner as in Example 1 except that the above was used.

Example 5 The coating amount of the surface sizing agent used in Example 1 was 0.00
A recording sheet was prepared in the same manner as in Example 1 except that the amount was 5 g / m ² .

Example 6 The coating amount of the surface sizing agent used in Example 1 was 0.05.
A recording sheet was prepared in the same manner as in Example 1 except that the amount was changed to g / m ² .

Example 7 The coating amount of the water-soluble polymer used in Example 1 was 0.5 g.
A recording paper was prepared in the same manner as in Example 1 except that the recording paper was / m ² .

Example 8 The coating amount of the water-soluble polymer used in Example 1 was 3.0 g.
A recording paper was prepared in the same manner as in Example 1 except that the recording paper was / m ² .

Example 9 The coating amount of the water-soluble polymer used in Example 1 was 4.0 g.
A recording paper was prepared in the same manner as in Example 1 except that the recording paper was / m ² .

Example 10 The water-soluble polymer oxidized starch used in Example 1 was mixed with PVA.
A recording paper was prepared in the same manner as in Example 1 except that (trade name: Gohsenal T330H, manufactured by Nippon Gosei Co., Ltd.).

Comparative Example 1 The paper hand-made in Example 1 was subjected to the same calendar treatment as in Example 1 to obtain a recording sheet.

Comparative Example 2 The same as Example 1 except that the cationic sizing agent used in Example 1 was replaced with the neutral sizing agent AKD (trade name Hacon 603S) and the addition amount was 0.1 part. A recording paper was prepared by the method.

Comparative Example 3 The amount of the cationic sizing agent used in Example 1 was changed to
A recording sheet was prepared in the same manner as in Example 1 except that the content was 0.2 parts. Here, the Steckigt sizing degree of the base paper was 1 second.

Comparative Example 4 The amount of the cationic sizing agent used in Example 1 was changed to
A recording sheet was prepared in the same manner as in Example 1 except that the amount was 0.5 part. Here, the Steckigt sizing degree of the base paper was 28 seconds.

Comparative Example 5 A nonanol-type penetrant (trade name: Laol XA-60-50, manufactured by Lion Corporation) was added to the surface size liquid used in Example 1, and the coating amount of the penetrant was 0.02 g / m ^2. A recording sheet was prepared in the same manner as in Example 1 except that the above was used.

Comparative Example 6 The same procedure as in Comparative Example 5 was carried out except that the penetrant used in Comparative Example 5 was replaced with a nonylphenol penetrant (trade name: Liponox NC150, manufactured by Lion). I got a recording sheet.

Example 7 A recording paper was prepared in the same manner as in Comparative Example 5, except that the penetrant used in Comparative Example 5 was replaced with an octylsuccinic acid penetrant (Ripard 870P, manufactured by Lion). Obtained.

The above results are shown in Table 1.

[0058]

[Table 1]

Here, the toner fixability is measured by using a PPC copying machine (5055, manufactured by Fuji Xerox Co., Ltd.), and a commercially available 18 mm width adhesive tape (cellophane tape) is applied to the image portion having an optical density of about 1.4. , Made by Nichiban Co., Ltd., and the toner peels off from the surface of the paper when the tape is peeled off x, when there is no problem in practical use Δ, and when good.
Evaluated as.

The sizing degree was measured by the Steckit method according to JISP8122.

In order to evaluate the performance as an ink jet recording paper, an ink jet printer (BJ10
V, manufactured by Canon Inc. is used for printing, and the optical density of the solid printing portion (hereinafter abbreviated as OD. Macbeth reflection densitometer model RD)
918), as an evaluation of ink bleeding, a shape factor S was measured by an image analyzer (Luzex 5000, manufactured by Nireco).
F2 was measured. The shape factor is 10 as it approaches a perfect circle.
This index is close to 0, and practically 250 or less is a level with no problem.

Further, immediately after the completion of printing on the printer, overwriting was carried out with a highlighter pen, and it was evaluated whether or not bleeding occurred. A sample that hardly bleeds was evaluated as ◯, a sample that had no practical problems was evaluated as Δ, and a sample in which the white paper portion was stained due to ink bleeding was evaluated as x.

As can be seen from Table 1, a cationic sizing agent was internally added to a base paper having a Steckigt size of 2 to 15 seconds, a surface sizing agent of 0.005 to 0.05 g / m ² , and a high water solubility. By coating the surface of the raw paper with a molecule in the range of 0.5 to 3.0 g / m ² , sufficient properties were obtained as an inkjet recording paper or a transfer paper for electrophotography.

[0064]

From the above examples, a recording paper obtained by applying a surface sizing agent and a surface sizing liquid containing a water-soluble polymer to the surface of a base paper internally added with the cationic sizing agent of the present invention. Was found to be a recording paper having the required performance as a transfer paper for electrophotography or an inkjet recording paper.

Claims (2)

[Claims] 1. A base paper having a Steckigt sizing degree of 2 to 15 seconds, containing calcium carbonate as a filler and a cationic sizing agent as an internal sizing agent, wherein the cationic sizing agent is styrene or a derivative thereof and acrylic acid or A recording paper comprising a copolymer of methacrylic acid ester and a surface sizing liquid comprising a surface sizing agent and a water-soluble polymer applied to the surface of the raw paper. The coating amount of 2. A surface sizing agent applied to the base paper surface, 0.005~0.05g / m ^2, the coating amount of the water-soluble polymer, is 0.5 to 3.0 g / m ² The recording sheet according to claim 1, wherein the recording sheet is a recording sheet.