JP2000272234A - Recording paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a recording paper having the adaptability for printings in general using an oxidation polymerization type ink, an ultraviolet curing type ink and the like, dealing with various information recording methods such as a thermal transfer recording method, an electronic photograph method and an ink jet recording method and provided with superior character quality level and image water resistance particularly in the ink jet recording using a water- soluble dye. SOLUTION: A recording layer, having a 0.5 g/m2-5.0 g/m2 solid content per one face and containing a cationic polymer compound formed of a water-soluble polymer binder, a cationic polymer compound A of 2.5 meq/g to 5.0 meq/g cationic density and a cationic polymer compound B of 5.0 meq/g-7.5 meq/g, is formed at least on one face of a substrate composed at least of a filler and a paper-making pulp.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for a printing method using an oxidative polymerization type or an ultraviolet curable ink, and is applicable to various information recording methods such as a thermal transfer recording method, an electrophotographic recording method and an ink jet recording method. The present invention also relates to a recording paper which is suitable for recording paper, and particularly excellent in water resistance and color development of a recorded image in ink jet recording using a water-soluble dye, and which can provide a high quality image.

[0002]

2. Description of the Related Art Printing properties such as surface strength and ink setting properties and label processing suitability are imparted to general printing paper and label paper as required. In particular, in the field of business form printing, in addition to ordinary multicolor printing, toner transferability and fixability are also provided in order to record variable data such as a product name and a barcode by an electrophotographic recording method.

[0003] For example, when a price bill, a product quote, a price tag, etc. are created using form paper or label paper,
Conventionally, invariant data such as ground patterns and ruled line frames are printed by general printing using oxidation polymerization type or ultraviolet curable ink, and variable data such as other product names, amounts and bar codes are recorded by electrophotography or thermal transfer recording. I have recorded in the system. On the other hand, in recent years, as the high-speed printing of the ink jet printer has progressed and the price has become lower, the demand for recording the variable data by the ink jet recording method has been increasing.

However, when ink-jet recording is performed on ordinary foam paper or the like as it is, the water resistance of the image is insufficient, and when water droplets adhere, the recorded image blurs. For this reason, it cannot be used for applications in which the value of information is lost due to the generation of a very small amount of bleeding like a bar code, and there is a limitation on the recorded contents.

[0005] On the other hand, most of ink jet recording papers are coated papers using silica or the like, and therefore generally have low surface strength, and are generally used in the field of business form printing, such as oxidation polymerization type and ultraviolet curable inks. In printing such as offset printing using such a method, there is a problem that a coating layer is formed on a plate due to tackiness of ink, and a white point is generated in a printed image, so that a good printed matter cannot be obtained.

[0006] In addition, various chemicals are used in such ink-jet recording paper for the purpose of imparting ink drying property, image water resistance, and color development to the coating layer. For example, JP-A-59-117525 discloses an example of an ink jet recording sheet containing cationic colloidal silica for the purpose of imparting image water resistance.
No. 2 discloses a quaternized product of polyvinyl pyridine;
Japanese Patent Application Laid-Open No. 9-2012 discloses a method using a reaction product of a secondary amine and epihalohydrin, and Japanese Patent Application Laid-Open No. Hei 10-119418 discloses a method using a reaction product of a tertiary diamine and dibenzyl halide.

However, in the conventional ink jet recording paper, sufficient water resistance cannot be obtained depending on the kind of the dye, and there are also cases where the coloring property is inferior. Thus, the ink jet recording paper having sufficient water resistance and color developing property can be obtained. Was not reached.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional recording paper, and enables printing using an oxidative polymerization type or an ultraviolet curable ink. It is an object of the present invention to provide a recording sheet which is excellent in image quality and can obtain a high-quality recorded image, and is compatible with a thermal transfer recording method and an electrophotographic recording method.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on a recording paper which achieves the above object, and as a result, by using a cationic polymer compound in two regions having different cation densities in combination, an image is obtained. The inventors have found that both water resistance and color development can be achieved, and have completed the present invention.

That is, according to the present invention, a recording layer containing a water-soluble polymer binder and a cationic polymer compound as main components is coated on at least one surface of a support made of pulp for papermaking. 0.5 g / m ^{2 to} 5 min.
0 g / m ² , wherein the cationic polymer compound has a cation density of 2.5 meq / g.
The cationic polymer compound (A) having a concentration of 5.0 meq / g or less and a cation density of more than 5.0 meq / g and 7.5.
It is intended to provide a recording sheet characterized by containing a cationic polymer compound (B) having a meq / g or less.

Further, the present invention provides that the cationic polymer compound (A) is a methacrylic acid-based quaternary ammonium salt derivative and the cationic polymer compound (B) is an alkylamine / epichlorohydrin-based polymer compound. The present invention provides the above-described recording paper.

Further, the present invention provides the above-mentioned recording paper wherein the surface of the recording layer has an Oken type smoothness of 40 seconds or more.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The cation density referred to in the present invention is:
It was measured by a general colloid titration method using (1/400) N polyvinyl potassium sulfate (PVSK) solution as a titrant and a 0.1% toluidine blue solution as an indicator. is there.

[0014]

(Equation 1)

In the present invention, the cationic polymer compound (A) having a cation density of 2.5 meq / g or more and 5.0 meq / g or less in the recording layer and a cation density of 5.0 meq / g.
A cationic polymer compound (B) having a content of more than q / g and not more than 7.5 meq / g is simultaneously contained. More preferred cation density of the cationic polymer compound (A) is 3.0 to 4.0.
5 meq / g, and a more preferred cation density of the cationic polymer compound (B) is 5.5 to 7.0 meq / g.
g.

When a cationic polymer compound having a cation density of less than 2.5 meq / g is used as the cationic polymer compound (A), the water resistance of an ink jet recorded image becomes insufficient, and the image resistance of an image such as a bar code becomes poor. Cannot be used for applications where retention is very important. Conversely, the cationic polymer compound (B) has a cation density of 7.5 meq / g.
When a cationic polymer compound exceeding the above is used, problems such as a change in color development of an image, a decrease in recording density, and uneven recording in a solid portion occur, and character quality and image quality are impaired. The change in the coloring property is particularly noticeable when recording is performed with an ink using a dye containing a carboxyl group.

The weight ratio of the cationic polymer compound (A) to the cationic polymer compound (B) is from 2: 8 to A: B.
Preferably, the ratio is 8: 2. More preferably, the weight ratio of A: B is 3: 7 to 7: 3.

In the recording layer, the cationic polymer compound (A)
When the composition contains only the compound, the desired image water resistance cannot be obtained. On the other hand, when only the cationic polymer compound (B) is contained, problems such as a change in color development of the image and a decrease in the recording density occur even if the desired image water resistance is obtained.

In the present invention, examples of the cationic polymer compound include dicyandiamide / alkylamine polymer compounds, dicyandiamide / formalin polymer compounds, polyethyleneimine derivatives, alkylamine / epichlorohydrin polymer compounds, and ammonia / epichlorohydrin. Commercially available chemicals such as a polymer compound, a polymethacrylic acid-based quaternary ammonium salt derivative, and polydiallyldimethylammonium chloride can be used, and the use of a polycondensation copolymer composed of two or more monomers is particularly preferable.

Such a cationic polymer compound may be used in an appropriate amount within the scope of the present invention.
In order to achieve both image water resistance and ink color development during inkjet recording, a polymethacrylic acid-based quaternary ammonium salt derivative is used as the cationic polymer compound (A).
As the cationic polymer compound (B), an alkylamine / epichlorohydrin polymer compound is preferably used.

The type of the water-soluble polymer binder used in the present invention is such that it has a strong adhesive strength to the base paper and a paper There is no particular limitation as long as blocking does not occur when superimposed. Such water-soluble polymer binders include starches such as oxidized starch, esterified starch, enzyme-modified starch, and cationized starch, polyvinyl alcohol and derivatives thereof, polyvinyl pyrrolidone, casein, proteins such as soy protein, Examples include cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose.

If necessary, for example, styrene-acryl resin, isobutylene-maleic anhydride resin, acrylic emulsion, vinyl acetate emulsion, vinylidene chloride emulsion, polyester emulsion, styrene emulsion
Water-dispersible resins such as butadiene latex and acrylonitrile-butadiene latex, as well as defoamers, surface sizing agents, water-proofing agents for water-soluble polymer binders, pH adjusters, dyes and colored pigments for adjusting hue, An appropriate amount of a fluorescent dye or the like can be used in the recording layer as long as the effects of the present invention are not impaired.

[0023] In the present invention, the recording layer a few 0.5g / m ² ~5.0g / m ² provided with a solid content to one surface of the support comprising a water-soluble polymer binder and a cationic polymer compound ones, and the more preferable to provide particular ^{1.0g / m 2 ~3.0g / m 2} .

When the recording layer is less than 0.5 g / m ² , the surface strength of the recording layer of the paper is low, and when the recording layer is printed with an oxidative polymerization type or ultraviolet curable ink, the printing ink has a high viscosity, so that the surface is exposed to the surface layer. Filler, pulp fibers, etc. in the support are taken up by the ink and deposited on a plate, an ink kneading roll, or the like, causing white spots on the image portion of the printed matter. Further, when inkjet recording is performed on paper having a recording layer of less than 0.5 g / m ² , problems such as a decrease in recording density and bleeding of ink along a filler or pulp fiber in a support exposed on the surface layer are caused. appear. On the other hand, if the recording layer is provided in an amount of more than 5.0 g / m ² , not only is it uneconomical, but also there are problems such as inability to cope with high-speed printing due to a change in coloring properties and poor ink drying properties in ink jet recording.

In the present invention, the amount of the cationic polymer in the recording layer is determined from the qualities of the ink-jet recorded image such as color development and water resistance. The total amount of the cationic polymer compound in the recording layer is water-soluble polymer binder 1
It is preferably in the range of 10 to 100 parts by weight, more preferably in the range of 20 to 80 parts by weight, per 100 parts by weight. When the total amount of the cationic polymer compound is less than 10 parts by weight, the water resistance of the image obtained by ink-jet recording tends to be insufficient within the above-mentioned range of the coating amount. If the retention of the polymer is extremely severe and the total amount of the cationic polymer compound exceeds 100 parts by weight, the change in the coloring property of the recorded image, the decrease in the recording density, and the recording of the solid portion may occur. Problems such as unevenness tend to occur, and image quality is impaired. The change in the coloring property is remarkable when recorded with an ink using a dye containing a carboxyl group. More preferably, the cationic polymer compound is incorporated in the recording layer in a total amount of 0.2 to 1.8 g / m ² . In the case of 0.2 g / m ^2, the water resistance of the image becomes insufficient, and in the case of more than 1.8 g / m ² , there is a tendency that a change in coloring properties and a decrease in recording density occur.

In the present invention, the total content of the water-soluble polymer binder and the cationic polymer compound in the recording layer is preferably at least 90% by weight. In general, when a pigment such as silica is contained in a large amount in the recording layer, the surface strength of the recording layer becomes weak. When ink-jet recording is performed on the recording paper of the present invention, the ink is absorbed by the water-soluble polymer binder and the support, so that it is not necessary to include an ink-absorbing pigment in the recording layer for the purpose of absorbing the ink.

On the other hand, in the present invention, a very small amount of pigment may be added to the recording layer for the purpose of adjusting the physical properties such as the friction coefficient of the recording paper surface. The pigment is not particularly limited, and can be appropriately selected from known pigments and used.

Further, in order to obtain good quality in the thermal transfer recording system, ordinary multicolor printing and the electrophotographic recording system, it is preferable that the surface of the recording paper has an Oken type smoothness of 40 seconds or more. If the Oken type smoothness is less than 40 seconds, the transfer of ink or toner is not uniform, and a good printed image cannot be obtained.

The support of the recording paper of the present invention is mainly composed of pulp for papermaking, and the pulp for papermaking is LB.
In addition to KP, NBKP, LBSP, NBSP, etc., non-wood fibers such as various kinds of used paper and kenaf are mentioned, and are not particularly limited. These may be used alone or in combination as necessary.

A filler may be internally added to the support used in the present invention. The filler to be internally added is not particularly limited, and can be appropriately selected from known fillers and used. Examples of such a filler include talc, kaolin, illite, calcined clay, calcium carbonate, titanium dioxide and the like. Filler usage is usually
The filler is added in an amount of 3 to 20% by weight in the paper. In the recording paper of the present invention, it is not preferable to add a filler in an amount of 20% by weight or more in terms of the filler rate in the paper, since the surface strength of the recording layer is weakened.

It is not preferable to use titanium dioxide or the like having a high refractive index as the filler because the optical density often causes a decrease in the recording density during ink jet recording. When a filler having a high refractive index is used, the filler rate in paper is preferably as small as possible without impairing print-through, or is preferably used in combination with another filler. As the filler of the present invention, talc and kaolin are particularly preferably used alone or in combination from the viewpoint of production cost.

In the present invention, an internal sizing agent may be used for the support. The internal sizing agent is not particularly limited, and can be appropriately selected from known internal sizing agents used for printing paper and ink jet recording paper. Preferred internal sizing agents include, for example, hydrophobically modified rosin emulsion sizing agents. Usually, the amount of the internal sizing agent used is adjusted in the range of 0.05 to 0.6 parts by weight with respect to 100 parts by weight of the pulp, but is not particularly limited.

In addition to the above, a defoaming agent, a pH adjuster, a dye or a color pigment for adjusting the hue, and a visibly improving whiteness are added to the support of the recording paper of the present invention, if necessary. Can be further used.

The recording layer of the present invention is provided by coating or impregnating a coating solution on a support. Using known coating methods such as size press, various blade coating, roll coating, air knife coating, bar coating, etc., it can be provided on one side or both sides of the support as necessary. From the viewpoint of cost and cost, it is preferable to use a size press coating method that can simultaneously apply both surfaces on-machine.

[0035]

As described above, according to the present invention, it is suitable for recording in various recording methods including general printing using an oxidative polymerization type or ultraviolet curable ink, etc., and particularly, image water resistance and character quality in ink jet recording. An excellent recording paper was obtained.

[0036]

EXAMPLES The specific structure of the recording sheet of the present invention will be described below with reference to examples, and the characteristics of the recording sheet will be described in comparison with comparative examples. However, the present invention is not limited to this example. is not. In the examples, “%” indicates “% by weight”, and “parts” indicates “parts by weight”.

Example 1 bleached hardwood kraft pulp (LB) having a freeness of 450 csf
KP) Kaolin 10 in pulp slurry consisting of 100 parts
Parts by weight, aluminum sulfate 1.5 parts by weight, an internal sizing agent 0.1 parts by weight, and a retention aid 0.02 parts by weight were added to a support using a twin-roll paper machine. A coating solution having a solid content of 10% in the composition shown in Table 1 was applied to both sides, and the coating amount per one side was 2.0 g in solid content.
/ M ² was provided on the recording layer. After that, a calendar process is applied to the Oken type smoothness (Japan Tappi).
No. 5) A recording paper having a basis weight of 64 g / m ² for 50 seconds was obtained.

[0038]

[Table 1] Recording liquid for recording layer (solid content except water)

Example 2 A recording having a basis weight of 64 g / m ² was carried out in the same manner as in Example 1 except that 15 parts of the polymethacrylic acid-based quaternary ammonium chloride as the cationic polymer (A) in Table 1 was used. I got the paper.

Example 3 The cationic polymers (A) and (B) shown in Table 1
Except that the basis weight was 64 g / g in the same manner as in Example 1.
to obtain a recording sheet of m ^2.

Example 4 Example 4 was repeated except that the coating liquid of Table 1 having a solid content of 15% was provided by air knife coating so that the coating amount per one side of the recording layer was 4.0 g / m ^2. The basis weight is 64 g / m as in the case of 1.
² recording papers were obtained.

Example 5 Recording having a basis weight of 64 g / m ² was performed in the same manner as in Example 1 except that the calendar conditions were adjusted after coating the recording layer so that the Oken type smoothness was 30 seconds. I got the paper.

Comparative Example 1 A basis weight of 64 g / g was obtained in the same manner as in Example 1 except that the polymethacrylic acid-based quaternary ammonium chloride in Table 1 was changed to 0 parts and the polycondensate of methylamine / ammonia / epichlorohydrin was set to 50 parts. to obtain a recording sheet of m ^2.

Comparative Example 2 The basis weight was 64 g / g in the same manner as in Example 1 except that the polymethacrylic acid-based quaternary ammonium chloride in Table 1 was 50 parts and the polycondensate of methylamine / ammonia / epichlorohydrin was 0 part. to obtain a recording sheet of m ^2.

Comparative Example 3 A basis weight of 64 g was obtained in the same manner as in Example 1 except that a cation density of 7.8 meq / g was used as the methylamine / ammonia / epichlorohydrin polycondensate shown in Table 1.
/ M ² of recording paper.

Comparative Example 4 A recording having a basis weight of 64 g / m ² was carried out in the same manner as in Example 1 except that a polymethacrylic acid-based quaternary ammonium chloride shown in Table 1 having a cation density of 2.3 meq / g was used. I got the paper.

Comparative Example 5 A recording layer was formed by coating with a coating roll having a solid content of 10% as shown in Table 1 so that the coating amount per one side was 0.3 g / m ^2. The basis weight is 64 g / m as in the case of 1.
² recording papers were obtained.

Comparative Example 6 Example 1 was repeated except that the recording layer was provided by air knife coating with the coating liquid of Table 1 having a solid content of 20% so that the coating amount per one side was 6.0 g / m ^2. In the same manner as in the case of the above, the basis weight is 64 g / m ^2.
Recording paper was obtained.

Comparative Example 7 Ethanolamine / epichlorohydrin polycondensate (cation density: 4.9 m) was used as the cationic polymer (A) in Table 1.
eq / g), and a recording paper having a basis weight of 64 g / m ² was obtained in the same manner as in Example 1 except that 50 parts of eq / g) were used.

Comparative Example 8 The cationic polymer shown in Table 1 was a polymethacrylic acid-based quaternary ammonium chloride cation density of 4.0 meq /.
g), 25 parts of ethanolamine / epichlorohydrin polycondensate (cation density: 4.9 meq / g),
Other than that used, it was the same as in Example 1 and the basis weight was 64 g /
to obtain a recording sheet of m ^2.

The ink jet recording test, printing test and thermal transfer recording test of the recording papers obtained in Examples 1 to 5 and Comparative Examples 1 to 8 were performed by the following methods. The results are shown in Tables 2 and 3.
And ○ and。 can be used without any particular problem.

(1) Printing Test The printing test was performed under the following test conditions, and evaluated according to criteria. Test conditions Printing machine RI printing machine Ink Sakata Ink NewGSL Red Ink amount 1.0 cc Rotation speed 80 rpm a, surface strength The degree of white spot generation in the solid printing portion was visually evaluated. ◎ No white spots are observed ○ White spots are slightly observed △ White spots are slightly observed × Many white spots are observed

(2) Inkjet recording test The recording test was performed using an inkjet printer (BJC-420).
J: trade name, manufactured by Canon Inc.), predetermined solid and ruled line patterns were recorded, and evaluated according to the following criteria. a, Whisker-like bleeding of ink (feathering) Blurring of whisker-like ink in a ruled line pattern was visually evaluated according to the following criteria. ◎ No whisker-like bleeding was observed. ○ Slight whisker-like bleeding was observed. △ Some whisker-like bleeding was observed. × Notable whisker-like bleeding was observed. B, Ink color development. Compared with paper (manufactured by Canon Inc.), it was visually evaluated according to the following criteria. ◎ No difference in color tone ○ Small difference in color tone △ Slight difference in color tone × Significant difference in color tone c, Water resistance of ink After being immersed in tap water adjusted to ΔC for 5 minutes and allowed to air dry, changes in the image were visually evaluated according to the following criteria. ◎ No image change ○ Very slight image change △ Image change × Most of the image is flowing

(3) Thermal transfer recording test The recording test was performed using a thermal transfer printer (Zebra 140Xi:
(Brand name manufactured by Zebra Technologies)
And recorded according to the following criteria. a, Solid uniformity The uniformity (presence or absence of white spots) of the solid recording portion was visually evaluated. ◎ No white spots are observed ○ White spots are slightly observed △ White spots are slightly observed × Many white spots are observed (4) Measurement of coating amount of recording layer The coating amount of the recording layer conforms to JIS P8124. The grammage of the recording paper provided with the recording layer and the grammage of the support used for the recording paper were respectively measured by the same gravimetric measurement, and the difference between the grammages of the two was calculated and used.

[0055]

[Table 2] Table 2 Formulation and physical properties

[0056]

[Table 3] Table 3 Evaluation results

Continued on the front page (72) Inventor Tsuyoshi Yasuda 1-30-6 Kamiochiai, Shinjuku-ku, Tokyo Japan Paper Products Co., Ltd. Product Development Laboratory F-term (reference) 2H086 BA21 BA35 BA41 BA44 4F100 AK01B AK25B AK35B AS00B BA02 DG02A EH46B GB90 JB07 JB09B JK15B YY00B

Claims (3)

[Claims] 1. A recording layer containing a water-soluble polymer binder and a cationic polymer compound as main components on at least one surface of a support made of pulp for papermaking. a recording sheet provided so as to ^{5g / m 2 ~5.0g / m 2} , wherein the cationic polymer compound is a cationic density 2.5 meq / g or more 5.0 meq / g
A recording paper comprising: a cationic polymer compound (A) as described below and a cationic polymer compound (B) having a cation density of more than 5.0 meq / g and not more than 7.5 meq / g. 2. The cationic polymer compound (A) is a methacrylic acid-based quaternary ammonium salt derivative, and the cationic polymer compound (B) is an alkylamine / epichlorohydrin-based polymer compound. The recording sheet according to claim 1. 3. The recording paper according to claim 1, wherein the surface of the recording layer has an Oken-type smoothness of 40 seconds or more.