JPH0759799B2 - Method for producing cast coated paper - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing cast coated paper, and more particularly to a method capable of producing cast coated paper having high quality with high productivity. .

(Prior Art) A cast drum is a heating drum in which a water-soluble coating liquid containing a pigment and an adhesive as a main component is applied to a base paper, and then a coating layer having plasticity in a wet state is mirror-finished. It is manufactured by press-bonding on the surface of, and drying, and copying the mirror surface onto the coating layer. The cast coated paper thus obtained has a high white paper gloss and excellent surface smoothness as compared with ordinary super calendered coated paper, and thus an extremely excellent printing effect is obtained, and high-quality printed matter or It is used for high-grade paper containers.

However, in order to dry the wet coating layer by directly pressing it to the heating drum, the water content in the coating layer must pass through the base paper layer to the opposite side and evaporate. It is produced at a much slower rate and is less productive than conventional coated papers which are dried from the top of the layer.

Heretofore, various measures have been taken to increase the moisture permeability of the base paper layer and the productivity of cast coated paper.

For example, in Japanese Patent Laid-Open No. 56-26094, an attempt has been made to enhance the air permeability by subjecting a base paper for cast coated paper to corona discharge or spark discharge treatment in advance to open fine holes on the entire surface.

However, although the apparent air permeability is very low, it is difficult to significantly increase the productivity of the cast coated paper without improving the air permeability of the base paper layer during the production of the cast coated paper.

On the other hand, in order to improve the productivity of cast coated paper, the manufacturing apparatus, manufacturing method, coating liquid composition and the like have been improved and improved.

For example, there is a method in which an undercoating coating layer containing a pigment and an adhesive as a main component is first provided on a base paper, dried or semi-dried, and then a wet coating layer is provided as an overcoating coating layer.

According to the suspension method, since the quality of the cast coated paper can be sufficiently maintained even if the coating amount of the wet coating layer is reduced, the coating amount of the wet coating layer is reduced and The absolute amount of water can be reduced, and the amount of water vapor that passes through the base paper layer and escapes to the opposite side can be reduced.

However, the air permeability of the base paper provided with the undercoat coating layer is
Since it becomes significantly higher due to the effect of the undercoating layer and water vapor is hard to escape, the undercoating layer is provided to reduce the coating amount of the wet coating layer and the amount of evaporated water is reduced, but the cast coated paper is reduced. The drying property of is not promoted and the productivity is not improved so much.

(Problems to be solved by the invention) As described above, in the conventional cast coated paper, by increasing the air permeability of the base paper and increasing the drying speed, the production speed can be increased during the production of the cast coated paper. Improving the property has been an important issue in the production of cast coated paper.

The present inventors, in order to increase the productivity of cast coated paper,
As a result of intensive studies to improve the air permeability of the base paper, as a base paper used when manufacturing cast coated paper, in a slurry containing pulp and a filler, it hits against pulp.
005 to 0.1 parts by weight of cationic polyacrylamide polymer or 0.1 to 2.0 parts by weight of cationic modified starch per pulp and 0.005 to 0.05 parts by weight of anionic polyacrylamide per pulp and / or 0.02 to 0.5 parts by weight of pulp. Part of the anionic inorganic particles, the yield (Y) of the filler and the fine fibers in the papermaking process is calculated by the following formula: Y = 90 · logX-130 (where Y is expressed in% by weight). The yield ratio of the filler and the fine fibers, X is the basis weight of the base paper expressed in g / m ² , and a value greater than or equal to .

That is, it has been found that the air permeability is increased without deteriorating the formation of the base paper by manufacturing the paper making method generally called a high yield system. That is, in general, when producing a base paper in a paper machine, pulp fibers and fine fibers,
Fixing agents (sulfuric acid bands are used mainly in acidic papermaking, and cationic water-soluble polymer compounds (cationized starch, cationic polyacrylamide, etc.) are mainly used in acidic and papermaking. )
The sheet is formed by the entanglement between pulp fibers in the dehydration step, and the base paper is manufactured through the pressing and drying steps.

The base paper obtained in this way has fine voids and minute voids from the part in contact with the wire in the paper making process, but other parts have a mesh structure made of pulp fiber. It has a structure that covers the mesh with the accumulation of fillers and fine fibers.

Therefore, it was found that the distribution of minute voids was different and the vapor permeability of water vapor was inferior compared to the base paper using the high yield system.

That is, in the case of a base paper produced by using a high yield system, pulp fibers and fine fibers, a microflock is made with a filler, and since a sheet is formed thereafter, the mesh formed by the entanglement of pulp fibers is a fine fiber, It is easy to remain without being blocked by the charges.

When a cast coated paper is manufactured using such a base paper,
Compared with the case of using the base paper manufactured by the conventional method, the air permeability of water vapor is remarkably improved, the drying speed is increased, and the cast coated paper can be manufactured with high productivity.

(Means for Solving Problems) The present invention provides a coating layer containing a pigment and an adhesive as a main component on a base paper, and the coating layer is a mirror surface drum heated while being in a wet state. In a method for producing a cast coated paper which is pressed and has a high gloss finish, as the base paper, in a slurry containing pulp and a filler, 0.005 to 0.1 parts by weight of a cationic polyacrylamide polymer per pulp or a pulp is used. 0.1 to 2.0 parts by weight of cationic modified starch per pulp to pulp and 0.005 to 0.05 parts by weight of anionic polyacrylamide per pulp and / or per pulp
By adding 0.02 to 0.5 parts by weight of anionic inorganic particles, the yield (Y) of the filler and fine fibers in the papermaking process can be calculated by the following formula: Y = 90 · logX-130 (where Y is It is the yield rate of the filler and the fine fiber expressed in wt%, and X is the basis weight of the base paper expressed in g / m ² . A method for producing a cast coated paper, which comprises using a base paper as described above.

That is, the base paper used in the present invention is one type of cationic polymer selected from an acrylamide polymer having a cationic group and cationic modified starch in a slurry containing pulp and a filler, and an anionic acrylamide. Based polymer and / or anionic inorganic particles, 0.005 to 0.1 part by weight per pulp in the case of a cationic polyacrylamide polymer, 0.1 to 2.0 parts by weight per pulp in the case of cationic modified starch, anionic polyacrylamide In the case of 0.005 per pulp
By adding 0.05 parts by weight, and 0.02 to 0.5 parts by weight per pulp in the case of anionic inorganic particles, the yield (Y) of the filler and fine fibers in the papermaking process is calculated by the following formula: Y = 90. logX-130 (where Y is the yield of the filler and fine fibers expressed in wt% and X is the basis weight of the base paper expressed in g / m ² ). It is a base paper obtained by paper making and dry rolling.

The fine fibers and the filler in the pulp slurry form microflocs in the papermaking process due to the action of the cationic polymer and the anionic polymer and / or the anionic inorganic particles, and then a sheet is formed. The mesh formed by entanglement tends to remain without being blocked by fine fibers and fillers.

As a result, a highly permeable base paper that allows water vapor to easily pass therethrough is obtained.

Examples of the acrylamide-based polymer having a cationic group used in the present invention include a Hoffmann degradation product of an acrylamide-based polymer, a Mannich reaction product, or various kinds of (meth) acrylamide and a tertiary amino group or a quaternary ammonium group. Examples thereof include copolymers with (meth) acrylate-based monomers and / or (meth) acrylamide-based monomers.

As the cation-modified starch, any one having a tertiary amino group or a quaternary ammonium group can be used, but the degree of substitution (DS / glucose unit) is particularly 0.
It is preferably 02 or more.

As the anionic polyacrylamide, those containing 1 to 20 mol% of anionic groups in the molecule are preferable, and these are obtained by partially hydrolyzing polyacrylamide.

The above-mentioned acrylamide polymer having a cationic group, as the addition amount of the cationic modified starch, 0.005 to 0.1 parts by weight per pulp in the case of an acrylamide polymer having a cationic group, 0.1 to 2.0 parts by weight in the case of cationic modified starch. The department is general.

The addition amount of anionic polyacrylamide and anionic inorganic particles is 0.005 to 0.05 parts by weight per pulp in the case of anionic polyacrylamide, and 0.02 to 0.5 parts by weight per pulp in the case of anionic inorganic particles. It is common.

If it is less than the minimum rate specified for steam, the desired effect cannot be obtained, and if it exceeds the upper limit, the texture tends to deteriorate.

As a method of adding the cationic polymer and the anionic polymer and / or the anionic inorganic particles, it is particularly preferable to avoid adding the cationic polymer and the anionic polymer and / or the anionic inorganic particles at the same time. May be added first. However, it is generally desirable to add the cation type and the anion type in this order, and to add the latter after allowing the former time to be sufficiently dispersed in the pulp.

As the pulp used when making the raw paper in the high yield system referred to in the present invention, those used in ordinary paper machines are used, for example, chemical pulp (KP, SP, AP, etc.), mechanical pulp (SGP, There are SCP, RGP, CGP, TMP, CTMP, etc.) and waste paper pulp (DIP, etc.). These pulps are appropriately blended according to the specifications of the final product, subjected to a mechanical treatment, added with necessary auxiliary agents and the like, and then subjected to a paper machine. In theory, as a paper machine used in this case, not only a fourdrinier or cylinder type paper machine but also a double-sided dehydration type paper machine widely used in recent years may be used. In addition, as this papermaking method, acidic papermaking,
The paper is arbitrarily made by neutral (alkali) paper making and is not particularly limited. Furthermore, in making paper from these base papers, as with general base papers,
For example, in the case of acidic papermaking, talc, kaolin, plastic pigments, urea resins, and other fillers are used; in the case of neutral (alkaline) papermaking, calcium carbonate such as heavy calcium carbonate and light calcium carbonate, talc, kaolin, A filler such as a plastic pigment or a urea resin is appropriately mixed in the pulp slurry. The basis weight of the cast coated base paper produced by the above conditions is 30 to 300 g / m 2.
It is adjusted in the range of about ² .

In the method of the present invention, a cast coated paper is produced using the specific base paper prepared as described above, but the coating liquid composition for cast coating is not particularly limited, and is generally A coating liquid composition for cast paper containing a pigment and an adhesive as the main components can be used.

Examples of the pigment include clay, kaolin, aluminum hydroxide, calcium carbonate, titanium oxide, barium sulfate,
Zinc oxide, satin white, plastic pigment,
Pigments generally used for coated papers such as urea resins can be used alone or in combination.

Adhesives include starch, modified starch, casein,
Ordinary aqueous coating compositions such as natural adhesives such as proteins, styrene-butadiene copolymer latex, acrylonitrile-butadiene copolymer latex, acrylic ester emulsion latex, synthetic polymer adhesives such as polyvinyl alcohol, etc. One or more kinds of various natural and synthetic adhesives used in the product are appropriately combined and used.

Furthermore, in the coating composition, if necessary, a dispersant, a release agent,
Various auxiliaries such as a water-proofing agent, a defoaming agent, a dye, a coloring pigment, and a preservative can be appropriately added.

The specific base paper used in the present invention may be coated with a general pigment coating composition on one side or both sides, if necessary.

The coating amount is preferably about 5 to 30 g / m ² .

As a method for producing a cast coated paper using the specific base paper of the present invention, any of the known cast coating methods, i.e., wet casting method, rewet casting method, gelation casting method, may be used. Although good, the effect of the present invention is particularly remarkable in the wet casting method and gelling casting method.

(Effect of the Invention) By using the specific base paper of the present invention, the air permeability of water vapor is significantly improved as compared with the case of using the base paper manufactured by the conventional method, and the high speed as described in the examples. Made it possible to produce cast coated paper.

(Examples) Next, the present invention will be described with reference to examples in order to more specifically describe the present invention, but the present invention is not limited thereto.

All parts in the examples are parts by weight unless otherwise specified.

In the examples, the glossiness of white paper and the surface property are values obtained as follows.

White paper gloss: 75 ° gloss was measured using a gloss meter manufactured by Murakami Color Research Laboratory.

Surface property: The surface property of the cast coated paper is visually evaluated for unevenness of the gloss of the surface due to the texture of the base paper (excellent), ○, △, × (poor).
It was evaluated in four stages.

Example 1 0.1 part of alkyl ketene dimer, cationic polyacrylamide (trade name KL-65, manufactured by Kyoritsu Organic Industry Research Institute), anionic polyacrylamide (trade name Hermide B) were added to pulp slurry consisting of 10 parts of NBKP and 90 parts of LBDP. −15,
Harima Kasei Kogyo Co., Ltd.) and a stock with 10 parts of light calcium carbonate added as a filler, and papermaking with a paper machine,
A size press treatment was carried out so that 1.5 g / m ^{2 of} oxidized starch was adhered on both sides to obtain a base paper for cast coated paper having a basis weight of 85 g / m ² . This base paper was coated with the following composition: 100 parts of kaolin, 10 parts of casein, 15 parts of styrene-butadiene copolymer latex, 5 parts of release agent, 0.5 parts of defoaming agent, and 45 parts of solid content, and a coating liquid composition having a solid content concentration of 45%. Apply the coating so that the dry weight is 25 g / m ^2, and immediately apply 85 ℃.
A cast drum coated with a chrome-plated cast drum having a diameter of 600 mm which had been heated was dried and dried to obtain a cast coated paper.

The quality of the cast coated paper obtained in this manner had no problem, and the operating speed could be increased without causing operational problems due to poor drying such as drum pick and drum blister.

The obtained results are shown in Table 1.

Comparative Example 1 A cast coated paper was obtained in the same manner as in Example 1 except that the cationic polyacrylamide was used alone instead of the combined use of the cationic polyacrylamide and the anionic polyacrylamide. .

Table 1 shows the operability results and the paper quality during the casting process.

Example 2 0.1 part of alkyl ketene dimer, cationic modified starch (trade name CATO-F, manufactured by Oji National Co.), anionic polyacrylamide (trade name Hermide B15, Harima) were added to a pulp slurry consisting of 100 parts of LBKP as in Example 1. Kasei Kogyo Co., Ltd.) and a stock with 10 parts of light calcium carbonate added as a filler, prepared by a paper machine, and subjected to size press treatment so that oxidized starch adheres to both sides at 1.5 g / m ^2. A base paper for cast coated paper having an amount of 100 g / m ² was obtained.

The following composition was added to this base paper: Kaolin 80 parts Calcium carbonate 20 parts Casein 10 parts Styrene-butadiene copolymer latex 15 parts Release agent 5 parts Defoamer 0.5 parts Coating liquid composition with a solid content of 45% The product was coated in the same manner as in Example 1 to obtain a cast coated paper.

Table 1 shows the operability results and paper quality results during cast coating.

Comparative Example 2 A cast coated paper was obtained in the same manner as in Example 2 except that the cationic modified starch was used alone instead of the combined use of the cationic modified starch and the anionic polyacrylamide.

Table 1 shows the operability results and the paper quality during the casting process.

Example 3 A pulp slurry consisting of 100 parts of LBKP as in Example 2 was added to 0.1 part of alkyl ketene dimer, cationic polyacrylamide (trade name KL-65, manufactured by Kyoritsu Organic Industry Research Institute),
Prepare a stock containing natural zeolite (produced in Itaya district, Yamagata Prefecture) and 10 parts of light calcium carbonate as a filler, paper-making with a paper machine, and size press treatment so that 1.5 g / m ^{2 of} oxidized starch is attached on both sides. Then, a base paper for cast coated paper having a basis weight of 100 g / m ² was obtained.

The base liquid thus obtained was coated with the same coating liquid composition as in Example 2 in the same manner as in Example 1 to obtain a cast coated paper.

Table 1 shows the operability results and paper quality results during cast coating.

Example 4 A pulp slurry consisting of 15 parts of NBKP and 85 parts of LBKP as in Example 1 was added to 0.5 part of rosin size, 2.0 parts of sulfuric acid band,
Cationic polyacrylamide (trade name: KL-65, manufactured by Kyoritsu Organic Industry Research Institute), anionic polyacrylamide (trade name: Hermide B-15, manufactured by Harima Kasei Co., Ltd.) and 10 parts of talc for papermaking as a filler were added. prepared stock, paper making by paper machine, oxidized starch subjected to size press treatment to 1.5 g / m ² adhered on both sides to obtain a base paper for the cast coated paper having a basis weight of 85 g / m ^2.

The base paper was coated with the same coating composition as in Example 1 in the same manner as in Example 1 to obtain a cast coated paper.

Table 1 shows the operability results and paper quality results during cast coating.

Comparative Example 3 A cast coated paper was obtained in the same manner as in Example 4, except that the cationic polyacrylamide was used alone instead of the combined use of the cationic polyacrylamide and the anionic polyacrylamide. .

Table 1 shows the operability results and the paper quality during the casting process.

Example 5 Example 1 is the same as Example 1 except that the types and addition amounts of the cationic and anionic polymers of Example 1 were compounded as shown in Table 1.
I got a cast coated paper in the same way as. The cast operability results and paper quality are shown in Table 1.

Example 6 0.5 parts of rosin size, 2.0 parts of sulfuric acid band, cationic modified starch (trade name CATO-F, manufactured by Oji National Co., Ltd.), anionic polyacrylamide (trade name) in a pulp slurry consisting of 100 parts of LBKP as in Example 2 (Harmide B15, made by Harima Kasei Co., Ltd.) and 10 parts of talc for papermaking as a filler were prepared, papermaking was carried out by a paper machine, and size press treatment was performed so that 1.5 g / m ^{2 of} oxidized starch was attached on both sides. Was carried out to obtain a base paper for cast coated paper having a basis weight of 100 g / m ² .

This base paper was coated with the same coating composition as in Example 2 by the same method as in Example 2 to obtain a cast coated paper.

Table 1 shows the operability results and the paper quality during the casting process.

Example 7 Example 2 is the same as Example 2 except that the types and addition amounts of the cationic and anionic polymers of Example 2 were compounded as shown in Table 1.
I got a cast coated paper in the same way as. The cast operability results and paper quality are shown in Table 1.

Comparative Example 4 A cast coated paper was obtained in the same manner as in Example 6, except that the cationic modified starch was used alone instead of the combined use of the cationic modified starch and the anionic polyacrylamide.

Table 1 shows the operability results and the paper quality during the casting process.

Example 8 A base paper for cast coated paper having a basis weight of 66 g / m ² was obtained in exactly the same manner as in Example 1 except that the paper was made by a paper machine having a double-sided dehydration mechanism.

The base paper was cast in the same manner as in Example 1 to obtain cast coated paper.

Table 1 shows the operability results and the paper quality during the casting process.

Example 9 Basis weight as in Example 4 except for a pulp composition consisting of 10 parts NBKP, 80 parts LBKP and 10 parts mechanical pulp (CTMP).
A base paper for cast coated paper of 85 g / m ² was obtained.

The base paper was cast in the same manner as in Example 4 to obtain cast coated paper.

Table 1 shows the operability results and the paper quality during the casting process.

Example 10 A cast coated paper was obtained in the same manner as in Example 5 except that the pulp composition consisted of 80 parts LBKP and 20 parts DIP.

Table 1 shows the operability results and paper quality during casting.

Comparative Example 5 Paper was made using a paper machine having a double-sided dehydration mechanism as in Example 8, except that cationic polyacrylamide was used alone instead of using both cationic polyacrylamide and anionic polyacrylamide. A cast coated base paper of / m ² was obtained.

The base paper was cast in the same manner as in Example 1 to obtain cast coated paper.

Table 1 shows the operability results and the paper quality during the casting process.

Claims (1)

[Claims] 1. A cast coating in which a base paper is provided with a coating layer containing a pigment and an adhesive as main components, and while the coating layer is in a wet state, the coating layer is brought into pressure contact with a heated mirror surface drum to give a strong gloss finish. In the method for producing paper, as the base paper, in a slurry containing pulp and a filler, 0.005 to 0.1 part by weight of cationic polyacrylamide polymer per pulp or 0.1 to 2.0 parts by weight of cation per pulp. 0.005 to 0.05 parts by weight of anionic polyacrylamide per modified pulp and pulp and / or 0.02 to 0 per pulp.
By adding 5 parts by weight of anionic inorganic particles, the yield rate (Y) of the filler and fine fibers in the papermaking process was calculated by the following formula: Y = 90 · logX-130 (where Y is% by weight). Which is the yield rate of the filler and the fine fiber expressed by, and X is the basis weight of the base paper expressed in g / m ^2. ) A method for producing a cast coated paper, which comprises using