JPH0913298A - Printing paper having improved water-absorption, news printing paper and their production - Google Patents

Abstract

PURPOSE: To obtain a printing paper, especially a news printing paper having balanced water-absorption, surface strength and peeling resistance by externally adding a specific water-absorption controlling composition to a base paper. CONSTITUTION: An anionic copolymer such as styrene/maleic acid, styrene/ acrylic acid or α-olefin/maleic acid copolymer produced by compolymerizing (A) a modified starch or starch, (B) at least one kind of water-soluble polyacrylamide selected from nonionic polyacrylamide, cationic polyacrylamide having tertiary amine or quaternary amine and ampholytic polyacrylamide and (C) a monomer having a 6-10C hydrophobic substituent and a monomer having carboxyl group or sulfo group at ratios of A:(B+C)=10:1 to 10:10 and B:C=40:60 to 60:40. The composition is applied to a base paper with a gate roll coater at a rate of 0.05-1.0g/m<2> per one surface to obtain a printing paper having a drop water-absorption (in conformity with Japan TAPPI No.3) of 15-150 sheets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing paper, especially a newsprint paper, having improved water absorption, and a method for producing them.

[0002]

2. Description of the Related Art In recent years, printing technology has been changed to offset printing
Great progress has been made in color printing, high-speed mass printing, and automation. Along with this, even for printing paper,
Improvements in various physical properties are required in terms of workability and printability.

[0003] In particular, newsprint paper is generally a paper mainly composed of mechanical pulp or deinked pulp (hereinafter abbreviated as DIP), and is a paper classified into middle and lower grade paper, but on the other hand In newspaper printing, a specified number of copies must be surely printed within a specified time in a specified time zone, and is a paper that requires stricter quality than general printing paper. In this respect, newsprint paper is a special paper, and is classified uniquely in terms of paper classification. Recent newspaper printing papers are required to be lightweight and have a high DIP content, and while overcoming the negative aspects of these points,
It is necessary to make various improvements. In that sense, the improvement of newspaper printing paper is not the improvement of general printing paper.
It is a very different dimension.

Regarding newspaper printing, in recent years, from the viewpoint of various demands (for example, demand for high-speed printing, demand for color space, demand for multi-product printing, demand for automation, etc.), a computer system for newspaper printing has been proposed. Coupled with the time of introduction,
The shift from letterpress printing to offset printing is progressing rapidly.

The widespread use of offset printing requires newspaper printing paper of a quality different from that of letterpress printing newsprint printing paper. For example, (1) it has wet strength and does not run out of water, (2) its water absorption is kept moderate, and (3) it does not generate paper dust. Among the required qualities, retention of water absorption, in other words, water absorption control, is an important issue.

In general printing paper, the water absorption is controlled by, for example, adding a chemical such as a sizing agent internally or externally to give the printing paper size. Internal addition is a so-called wet end, which is a method of adding a chemical to the pulp slurry and containing the chemical inside the paper at the same time as the paper making.External addition is a size press or a gate roll coater after paper making. It is a method of applying a chemical to the paper surface using a coating machine typified by the above.

As the sizing agent for internal addition, in the case of acidic papermaking, reinforcing rosin sizing agent, emulsion sizing agent, synthetic sizing agent, etc., and in the case of neutral papermaking, alkyl ketene dimer (AKD), alkenyl succinic anhydride. Thing (AS
A) and the like are known. Further, JP-A-60-88196 and JP-A-4-363301 disclose a sizing agent comprising a cationized starch and an alkyl ketene dimer.

As the external sizing agent (also called surface sizing agent), anionic polymers such as styrene / maleic acid type copolymers and styrene / acrylic acid type copolymers; rosin, tall oil, and Anionic low molecular weight compounds such as saponified alkyd resins such as phthalic acid and saponified petroleum resins and rosins; cationic polymers such as styrene-based polymers and isocyanate-based polymers are known.

On the other hand, water absorption control in newsprint paper is performed by, for example, (a) internal addition of chemicals such as sizing agents and water-proofing agents, (b) change of raw material composition, (c) change of papermaking conditions, etc. Is currently being dealt with.

On the other hand, recent major trends in newsprint paper itself include weight reduction and higher DIP content.

Regarding weight reduction of newsprint paper, for example, in 1989, 96% of newsprint paper with a basis weight of 46 g / m ² was used.
In 1993, newsprint paper with a basis weight of 43 g / m ² accounted for about 80%. Such weight reduction causes problems such as a decrease in opacity of newspaper printing paper and a decrease in paper strength. On the other hand, the high content of DIP has led to an increase in various components derived from DIP (fine fibers, fillers, pigments, etc.). The increase in these ingredients is
It causes problems such as paper dust and paper weakness,
These problems also become more serious as the blending ratio of DIP increases. The trend of these newsprint papers is
In particular, it is a major negative factor in terms of surface strength.

Therefore, the newsprint paper for offset printing needs to have improved surface absorbency as well as improved surface strength while overcoming the disadvantages of weight reduction and high DIP content. There is a demand for much more severe quality improvement. For example, improving newsprint paper with a basis weight of less than 46 g / m ² is a much more difficult task than improving newsprint paper with a basis weight of 46 g / m ² or more. ing.

The improvement of the surface strength of newsprint paper is roughly classified into two measures: a non-coating measure and a coating measure. The non-coating measures are methods such as changing the raw material mix, changing the papermaking conditions, and increasing the amount of paper strengthening agent, etc., but this alone will no longer meet the strict quality requirements for newsprint paper for offset printing. It is a difficult situation. On the other hand, the countermeasures by coating are starch, modified starch (oxidized starch, starch derivative, etc.) and polyvinyl alcohol (hereinafter PVA).
It is a method of surface-coating (externally adding) a surface treatment agent (such as abbreviated) to the base paper for newsprint paper, which is an effective means for improving surface strength. Therefore, in the case of newsprint paper, the method of externally adding chemicals is an element that cannot be ignored in terms of improving the surface strength.

However, when a large amount of the chemical is used in the method of externally adding the chemical, the chemical exhibits tackiness when moistened with water. There is a problem that troubles (so-called “Neppari”) caused by adhesiveness such as peeling of paper and peeling of paper or slipping of printed papers from each other do not occur. Therefore, it was necessary to consider the releasability of the coated product in the method of externally adding a chemical.

[0015]

However, among the measures for controlling water absorption in newsprint paper, the method of internally adding chemicals such as sizing agents that are also used in general printing paper (internal size) is (1) Chemicals need to be added to the low consistency pulp slurry. (2) The fixed amount of chemicals on the pulp sheet is not constant. (Low fixing amount of chemicals) (3) Circulating white water is used. However, it was difficult to control the amount of chemicals added, and it was necessary to add them excessively. This excessive addition tends to cause deterioration of paper strength, machine trouble, remarkable white water stains, etc.
There was a problem in terms of operability.

Further, changing the blending of raw materials or changing the papermaking conditions is not appropriate as a long-term countermeasure, though it is a temporary countermeasure, because there are large fluctuations in the raw materials in the actual machine. .

The method of externally adding a surface treatment agent such as starch, modified starch (oxidized starch, starch derivative, etc.), PVA, etc., which is carried out as a measure for surface strength, is certainly effective in terms of surface strength. The water absorption could not be improved.

It is also conceivable to externally add a surface sizing agent used in general printing paper. However, these surface sizing agents also need to be characterized as surface strength countermeasure materials, and these surface sizing agents are, compared with starch, modified starch (oxidized starch, starch derivative, etc.), PVA, etc.
It was not possible to improve the surface strength and water absorption in a well-balanced manner. Further, it is not satisfactory in terms of material economy and peelability of the coated product.

In view of the above, the present invention has an object to provide a printing paper, particularly a newspaper printing paper, which has improved both water absorption and surface strength in a well-balanced manner by only external addition of chemicals, and a method for producing the same.

[0020]

[Means for Solving the Problems] The above problems mainly consist of a modified starch (or starch), a cationic (or amphoteric) polyacrylamide, and an anionic water-soluble copolymer on a printing base paper. The problem was solved by providing a water absorption control layer. This method is effective for general printing paper as well, but is particularly effective for newsprint paper, and will be described below as newsprint paper.

[0021] Modified raw starch (eg, modified starch)
Oxidized starch, etherified starch, etc.), starch, nonionic polyacrylamide, cationic polyacrylamide (water-soluble polyacrylamide having tertiary amine group or quaternary ammonium group), and amphoteric polyacrylamide applied alone Even though the surface strength could be improved, the water absorption could not be improved. For example, apply oxidized starch to newsprint base paper and apply
Even when applied in the range of 0.5 to 1.0 g / m ² , it was about several seconds by the drip water absorption method described later.

Further, the coating of the copolymer having an anionic hydrophobic group alone could not improve the water absorption at a level where the releasability was not a problem.

As will be described later, the water absorption control layer of the present invention can be considered to be based on an ionic complex. An example of applying such a complex to a chemical for paper is, for example, the paper paper technical magazine (VOL.45, No.2, (1991) 245-249), which describes anionic paper strength agents and special cationic agents. A method is described in which a paper strength agent mixed with a paper strength agent to form a high molecular weight ion complex is added to a pulp slurry. However, this method is merely a method of internally adding a chemical and is not intended to improve water absorption. Further, JP-A-60-119297 discloses a method for sizing paper using an anionic hydrophobic sizing agent and a cationic holding agent. However, this method is also a method of internally adding a chemical and cannot solve the above-mentioned problems associated with internal addition.

On the other hand, JP-A-52-148211 and JP-A-562-182
-118995 and Japanese Patent Laid-Open No. 3-54609 disclose a surface sizing method using a coating solution containing an anionic resin and a cationic resin. JP
Japanese Patent No. 52-148211 describes a method for producing a reinforced core paper for corrugated board using a coating solution containing an anionic resin and a cationic resin. However,
This method is mainly intended to improve the compressive strength and the rigidity, and is not particularly intended to improve the water absorption. Further, in this method, the coating amount is about 10 g / m ² , which is far from being applied to general printing paper. JP-A-56-118995 describes a method for producing oil resistant paper using a surface sizing agent composed of, for example, oxidized starch, vinylidene chloride / acrylamide copolymer and polyethyleneimine. However, while the oil resistant paper is a paper that is required to have resistance to oil, the printing paper of the present invention has a high absorbency for oil (in other words, ink) in response to high-speed printing in offset printing. It is the paper that is required, and the exact opposite of the technology. Further, JP-A-56-118995 discloses a surface sizing agent composed of a ketene dimer, a cationized starch and an anionic polymer, but it has a problem of lowering the friction coefficient.

Further, in JP-A-62-122781 and JP-A-62-146674, there is provided a recording material for ink jet recording having an ink receiving layer containing a polymer complex of a basic polymer and an acidic polymer. The material is disclosed. However, in these publications, both polymers are dissolved in an organic solvent such as dimethylformamide,
Since it is used as a coating liquid, it is difficult to adapt it to general printing paper. Further, the recording material for ink jet recording is required to have receptivity (in other words, absorbability) for an ink composed of a water-polyhydric alcohol mixture system, which is different from the water absorption required in the present invention. It is a thing.

However, the present inventors have found that modified starch,
Alternatively, the water absorption was improved only by external addition, and the surface strength and the releasability were improved in a well-balanced manner only by combining starch, a specific polyacrylamide, and a copolymer having an anionic hydrophobic group. It was found that a newspaper printing paper could be obtained, and the present invention was completed.

That is, according to the present invention, a newspaper printing paper is provided with a coating layer containing a water-absorbent control composition mainly containing the following three components A, B and C on the surface of the paper. Regarding

Component A: Modified starch or starch Component B: 1) Nonionic polyacrylamide 2) Cationic polyacrylamide (water-soluble polyacrylamide having tertiary amine group) 3) Cationic polyacrylamide (quaternary) Water-soluble polyacrylamide having ammonium group) 4) Amphoteric polyacrylamide At least one water-soluble polyacrylamide selected from the above 1) to 4) Component C: a monomer having a hydrophobic substituent having 6 to 10 carbon atoms , An anionic copolymer with a monomer having a carboxyl group or a sulfonic acid group, the water-absorbing control composition of the present invention comprises the above component A,
It is composed mainly of three components B and C.

Component A used in the water absorption control composition of the present invention is modified starch or starch, or a mixture of modified starch and starch. The modified starch is described in detail, for example, in "Muranori Nakamura, Shigeo Suzuki: Starch Science Handbook, Asakura Shoten Co., Ltd., 1977, p496-522", and the modified starch used in the present invention is modified starch. (Ammonium persulfate (APS) modified starch, enzyme modified starch, starch for thermochemical modification described in JP-A-60-28475,
Examples thereof include starch for thermochemical modification described in JP-A-163471), pregelatinized starch, oxidized starch, starch derivatives (esterified starch, etherified starch, cross-linked starch, etc.), and grafted starch. In the present invention, these starches may be used alone or as a mixture of two or more kinds. Among these, gate roll coating suitability, that is,
Those having properties such as (a) high solution concentration and low viscosity, (b) high aging resistance, and (c) excellent film-forming ability are preferable, and oxidized starch and etherified starch are more preferable.

The component B used in the water-absorbent control composition of the present invention is a specific water-soluble polyacrylamide having a cationic property (hereinafter abbreviated as PAM), a nonionic PAM, a cationic PAM (tertiary grade). PAMs having amine groups and / or quaternary ammonium groups), amphoteric PAMs are included. Nonionic PAM has a part of the amide structure in the form of amidinium (—CONH ₃ ⁺ ) and is considered to have a slight cationic property.
It is possible to use it as the component B used in the present invention. Further, as the component B, each PAM may be used alone, or may be used as a mixture.

For each PAM used as the component B, the corresponding monomer is prepared by a conventionally known method such as an aqueous solution polymerization method, a solvent polymerization method, a reverse phase emulsion polymerization method, a precipitation polymerization method or a suspension polymerization method. It may be polymerized or copolymerized.

Nonionic PAM used as component B
For example, (meth) acrylamide (where
(Meth) is used as an indication that meta is included, and (meth) acrylamide means methacrylamide and / or acrylamide. The same shall apply hereinafter), or a copolymer, a nonionic monomer copolymerizable with (meth) acrylamide, and (meth)
Examples thereof include acrylamide copolymers.

The cationic PAM and amphoteric PAM used as the component B are
It is a PAM having a tertiary amine group and / or a quaternary ammonium group. Basically, a PAM having no anionic residue other than the cationic residue is a cationic PAM, while a PAM having an anionic residue other than the cationic residue is an amphoteric PAM. The ratio of cationic residues in these PAMs is preferably 0.1 mol% or more. The ratio of cationic residues is 0.1
If it is less than mol%, the effect of water absorption control tends to be slightly weakened.

As a method for introducing a cationic residue into PAM, for example, (a) a method of copolymerizing a monomer having a tertiary amine group or a quaternary ammonium group,
(b) A method of modifying a PAM polymer by using the Mannich reaction, (c) A method of modifying a PAM polymer by using a Hoffmann decomposition reaction, and (d) a copolymerization of a monomer having a tertiary amine group. Then, a method of converting to a quaternary ammonium group by a reaction such as alkylation or arylation can be given.

In the method of copolymerizing (a), (meth) acrylamide and a cationic monomer (tertiary amine group,
Alternatively, it may be copolymerized using a monomer having a quaternary ammonium group). In this method, examples of the monomer having a tertiary amine group used include:
N, N-Dimethylaminoethyl (meth) acrylate, N, N-
Diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminohydroxypropyl (meth) acrylate, N-
Methyl, N-ethylaminoethyl (meth) acrylate,
N, N-diphenylaminoethyl (meth) acrylate, N,
N-dimethylaminoethyl (meth) acrylamide, N, N-
Diethylaminopropyl (meth) acrylamide, N, N-
Examples thereof include dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, 2-vinylpyridine, 4-vinylpyridine and 2-methyl-5-vinylpyridine.

As the monomer having a quaternary ammonium group which can be used, (meth) acroyloxyethyl trimethylammonium chloride, (meth) acroyloxyethyl dimethylbenzylammonium chloride, (meth) acroyloxy Ethyltriethylammonium chloride, (meth) acryloyloxyethyldiethylbenzylammonium chloride, (meth) acrylamidopropyltrimethylammonium chloride, (meth) acrylamidopropyltriethylammonium chloride, (meth) acrylamidopropyldimethylbenzylammonium chloride, diallyldimethylammonium chloride , Diallyldiethyl ammonium chloride, (meth) acroyloxyethyl trimethyl Such as Le ammonium sulfate are exemplified.

In this copolymerization method, (meth) acrylamide or a monomer copolymerizable with the above-mentioned cationic monomer may be used within the range not hindering the present invention. Examples of the copolymerizable monomer include ethylene, butadiene, styrene, α-methylstyrene, isoprene, propylene, vinyl acetate, vinylcarbazole, vinylpyrrolidone, (meth) acrylonitrile, (meth) acrylic acid ester, and N-methylol group. (Meth) acrylamide, methylenebisacrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-sulfoethyl (meth) acrylate, ethylenedi (meth) acrylate, acrylic acid, methacrylic acid, maleic acid , Fumaric acid, itaconic acid, muconic acid, crotonic acid, allyl glycidyl ether, glycidyl (meth) acrylate, sodium salt of ethylene sulfonate, sodium salt of p-styrene sulfonate, vinylbenzyl sulphate Salts, and vinyl benzyl phosphonium salt.
Amphoteric PAM can be obtained by using anionic monomers such as acrylic acid and itaconic acid among these monomers.

In the method (d) of converting a tertiary amine group to a quaternary ammonium group, the alkylating agent used is, for example, dimethylsulfate, methyl chloride, methyl bromide, methyl iodide, or chloride. Examples thereof include benzyl and benzyl bromide.

PAM used as component B according to the invention
Is preferably about 10,000 to 4,000,000, more preferably 50,000 to 1,000,000. If the molecular weight is less than 10,000, PAM of component B
Is not preferable in terms of surface strength and water absorption control because a sufficient film cannot be formed. On the other hand, the molecular weight is 400
If it is larger than 10,000, the viscosity of the PAM becomes high, which may cause operational problems.

Among the PAM used as the component B,
Cationic PAM (tertiary amine group and / or quaternary amine group
Having a primary ammonium group), and amphoteric PAM
However, it is more preferable than nonionic PAM in terms of water absorption control (water absorption impartation). This is because in nonionic PAM, the cationicity derived from the amidinium structure that is partially present is weak. Also,
Comparing the cationic PAM and the amphoteric PAM, the cationic PAM is more preferable when high water absorption is desired.

Component C used in the water absorption control composition of the present invention has an anionic monomer (a monomer having a carboxyl group or a sulfonic acid group) and a hydrophobic substituent having 6 to 10 carbon atoms. It is a copolymer with a monomer.

Examples of the monomer having a carboxyl group or a sulfonic acid group include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, muconic acid, crotonic acid, 2-acrylamido-2-methylpropanesulfonic acid. , 2-sulfoethyl methacrylate, styrene sulfonic acid, ethylene sulfonic acid and the like.

As the monomer having a hydrophobic substituent,
Styrene, α-methylstyrene, (meth) acrylic acid ester, maleic acid ester, olefins (for example,
Octene, decene, etc.) and the like.

In this copolymer, the ratio of the anionic monomer to the monomer having the hydrophobic substituent is 60: 40-
A range of 10:90 is desirable. The anionic monomer and the monomer having a hydrophobic substituent each have at least 1
You can use more than one type.

Further, in this copolymer, a small amount of anionic or nonionic monomer capable of polymerizing with the above-mentioned anionic monomer and / or a monomer having a hydrophobic substituent is copolymerized within a range not hindering the present invention. It may be polymerized.

Examples of the method for producing the copolymer include an aqueous solution polymerization method, a solvent polymerization method, a reverse phase emulsion polymerization method, a precipitation polymerization method and a suspension polymerization method.

In other words, this copolymer is an anionic hydrophilic polymer, and its acid value is preferably in the range of 50 to 500, and further limited, it is 100 to 100.
It is desirable to be in the range of 300. When the acid value is less than 50, the copolymer has insufficient water solubility and weak interaction with the component B, which is not preferable. Also,
If the acid value is greater than 500, the copolymer is not good because it is too anionic.

Further, the copolymer may have a weight average molecular weight of about 10 to 3,000,000, and more preferably
The range of 01,000 to 100,000 is desirable. When the molecular weight is less than 10 thousand, the copolymer of the component C cannot form a sufficient film, which is not preferable in terms of surface strength and water absorption control. On the other hand, when the molecular weight is more than 3,000,000, there is a risk of causing operational problems due to the high viscosity of the coating liquid.

Specific examples of the copolymer used as the component C include styrene / (meth) acrylic acid copolymer, styrene / (meth) acrylic acid / (meth) acrylic acid ester copolymer, and (meth ) Acrylic acid / (meth) acrylic acid ester copolymer, styrene / maleic acid copolymer, styrene / maleic acid alcohol ester copolymer, olefin / maleic acid copolymer and the like can be mentioned. Among these, styrene / (meth) acrylic acid copolymer, styrene / (meth) acrylic acid / (meth) acrylic acid ester copolymer, and olefin /
A maleic acid copolymer is more preferable from the viewpoint of imparting water absorption. In addition, in particular, the styrene / (meth) acrylic acid copolymer and the styrene / (meth) acrylic acid / (meth) acrylic acid ester copolymer are excellent in that the balance between the hydrophilic substituent and the hydrophobic substituent is excellent. Coalition is more desirable.

As described above, the water absorption control composition of the present invention is mainly composed of the three components A, B and C. The ratio (weight ratio) of each component of the composition depends on the required degree of water absorption, the degree of releasability, or the coating amount of the composition on the manufactured newsprint paper. It cannot be limited. However, if it is intentionally limited, the ratio (A: (B + C)) of the component A and the remaining two components (component B + component C) is 10: 0.3.
The ratio (B: C) of the component B to the component C may be in the range of 20:80 to 80:20, and more preferably A: (B + C)
= 10: 1 to 10:10 and B: C = 40: 60 to 60:
A range of 40 is good.

The water-absorption control composition used in the present invention may be composed of only three components A, B, and C, and in the coating amount range described below, they alone can obtain good releasability. Is possible. However, in order to further improve the releasability, in other words, as a measure against the Nappari, a range that does not hinder the present invention (for example, does not adversely affect the water absorption, foaming at the time of coating at a level where there is no problem in coating). A small amount of anti-blocking agent may be added.
Examples of the peeling component include a monoalkenyl succinate described in JP-B-63-58960, an anti-adhesive agent containing an organic fluoro compound described in JP-A-6-57688, and JP-A-6-57688.
An anti-adhesive agent containing a substituted succinic acid and / or a substituted succinic acid derivative described in Japanese Patent No. 192995 as an active ingredient can be mentioned. An appropriate addition rate of the anti-tack agent is 5% or less (% by weight). If the addition rate is higher than 5%, there may be a problem of foaming during coating.

The water-absorption control composition of the present invention basically does not need to be used in combination with other binder-like components, but is in a range not hindering the present invention (particularly, a range in which releasability is not affected). In some cases, such components may be included in small amounts. As other binder-like components, for example, celluloses such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose; latexes such as styrene / butadiene copolymer, styrene / acrylonitrile copolymer, styrene / butadiene / acrylic ester copolymer; Fully saponified PVA, partially saponified PVA,
PVA such as amide-modified PVA, carboxy-modified PVA, sulfonic acid-modified PVA; silicone resin, petroleum resin,
Examples include various resins such as terpene resin, ketone resin, and coumarone resin. In particular, PVA's tend to increase the tackiness of paper when wet when applied to paper,
Careful attention must be paid to the amount of the combination when using it in combination.

The water-absorption control composition of the present invention contains auxiliary agents and fillers such as preservatives, antifoaming agents, UV inhibitors, optical brighteners, viscosity stabilizers, etc. within a range that does not affect the present invention. May be included.

The base paper for newsprint paper used in the present invention is ground pulp (GP) or thermomechanical pulp (TM).
P), mechanical pulp such as semi-chemical pulp (M
P), chemical pulp (CP) represented by kraft pulp (KP), deinked pulp (DIP) obtained by deinking waste paper containing these pulps, and disintegrating broke from the papermaking process The recovered pulp etc. obtained is
Alternatively, they are mixed at an arbitrary ratio. The effect of the present invention is remarkable on the base paper made into a paper having a basis weight of less than 46 g / m ² . In the case of base paper with a basis weight of 46 g / m ² or more, the base paper is
It is considered to have sufficient surface strength, and it is considered that the dimensional change of the paper due to the dampening water during offset printing or the decrease in strength is negligible. It is not necessary to improve both the property and the surface strength at the same time. Further, the DIP may be blended in an arbitrary range (0 to 100%). In view of the recent trend of high compounding of DIP,
The range of 30 to 70% is more preferable.

This newsprint base paper is, if necessary,
White carbon, clay, silica, talc, titanium oxide, calcium carbonate, synthetic resin (vinyl chloride resin, polystyrene resin, urea formalin resin, melamine resin,
Styrene / butadiene copolymer resin, etc.) for papermaking; polyacrylamide polymer, polyvinyl alcohol polymer, cationized starch, urea / formalin resin, melamine / formalin resin, etc. paper strengthening agent; acrylamide / Aminomethyl acrylamide copolymer salt, cationized starch, polyethyleneimine, polyethylene oxide, acrylamide / sodium acrylate copolymer etc. drainage / yield improver; aluminum sulfate (sulfate band), UV inhibitor, anti-fading You may contain auxiliary agents, such as an agent. However, it is necessary to add these agents within a range that does not impair the water absorption control by external addition. The physical properties of this base paper must be such that it can be printed by an offset printing machine, and it is sufficient if it has physical properties such as tensile strength, tear strength and elongation that are comparable to those of ordinary newspaper printing paper.

Further, the newsprint paper base paper may be one having an internally added size. However, in the present invention, there is also a meaning to solve the problems associated with the internal addition as described above, and if anything, it is more effective to use the base paper to which the internal addition sizing agent is not applied, to achieve the effect of the present invention. Can be made. From the viewpoint of water absorption, a base paper having a drip water absorption of 10 seconds or less may be used in the drip water absorption method described below.

The newsprint paper with improved water absorption of the present invention has the above-mentioned newsprint base paper on one side or both sides,
It is produced by externally adding the above-mentioned water absorption control composition using a coating machine.

Two methods are known as a method for evaluating the water absorbency of the surface of a paper of low size such as newsprint paper. One method is a drip water absorption method based on Japan TAPPI No.33. This method is a method in which 1 μl of water is dropped on the paper surface and the time until the water droplet is absorbed on the paper surface is measured. Another method is a method of measuring a contact angle (contact angle method). In the present invention, 5 μl of water is dropped,
The method was to measure the contact angle of a water drop after a certain period of time (5 seconds). The higher the water absorption (the higher the water absorption resistance), the longer the absorption time by the drip water absorption method, and the larger the contact angle by the contact angle method, and the longer the retention time.

By providing a base paper for newsprint paper with a coating layer containing the water absorption control composition of the present invention,
It is possible to control the water absorption in a wide range from 10 seconds to 600 seconds by the drip water absorption method. In terms of the contact angle method, water absorption can be controlled by the above-mentioned method in the contact angle range of 75 to 95 degrees. That is, the water absorption of newsprint paper can be controlled to a predetermined water absorption by the type of each component, the compounding ratio of each component, the coating amount of the composition, and the like.

The degree of water absorption may be appropriately determined according to the specifications required for the product and is not particularly limited. However, if it is intentionally limited, a range of 15 seconds to 150 seconds by the drip water absorption method is a more preferable degree of water absorption.

The water absorption control composition of the present invention effectively exhibits its effect when the coating amount is in the range of 0.05 to 1.0 g / m ² (per surface). Coating amount is 0.05g / m ²
If it is less than 1, the water absorption cannot be improved probably because the water absorption control composition cannot form a sufficient barrier layer. On the other hand, even if the coating amount is higher than 1.0 g / m ² , there is a disadvantage that the releasability deteriorates (a neppar phenomenon occurs). It is also uneconomical in terms of cost. When considering application to newsprint paper, considering the total surface strength and peelability, the coating amount of the water absorption control composition of the present invention is 0.1 to 0.5 g / m ² (per surface). Range is desirable. As a matter of course, the coating amount should be determined according to the degree of water absorption required for newsprint paper, and the range is not particularly limited.
Also, it goes without saying that it is desirable to impart water absorption with a coating amount as small as possible according to the required degree of water absorption.

As a coating machine, a size press, a bar coater, an air knife coater, a gate roll coater,
A blade rod metalling coater etc. are mentioned.
Among these coaters, transfer type coaters such as a gate roll coater and a blade rod metering coater are preferable, and a gate roll coater is most preferable. The coating method using a transfer coater is, for example, a method using a size press in which the base paper is once dipped in a pond (liquid puddle) of the coating liquid existing between the rolls. Is a method of forming a coating film having a constant thickness on the roll surface and applying the coating film to the base paper. Therefore, with this transfer coater method, it is possible to coat the surface of the raw paper very efficiently. As described above, since the newspaper printing paper of the present invention has a low coating amount, it is effective to use a transfer type coater (particularly, a gate roll coater or a blade rod metalling coater).

Further, the water absorption control composition of the present invention exerts its effect to a great extent particularly in the system using a gate roll coater. That is, the water absorption control composition of the present invention can improve water absorption efficiently in the above-mentioned coating amount range by using a coating method using a gate roll coater.

Considering the maintenance of the coater, double-sided coating with a gate roll coater is most desirable for the newsprint paper of the present invention. Needless to say, the on-machine coater is preferable as the coater in terms of productivity.

That is, the water absorption control composition of the present invention was applied to a base paper for newsprint paper having a drip absorption of 10 seconds or less,
It may be applied with a gate roll coater in an application amount of 0.05 to 1.0 g / m ² .

In the case of newsprint paper, the surface of the paper is not uniform, and it is difficult to provide a water-absorbing barrier layer on the surface of the paper in the low coating amount region by external addition.
However, the water absorption control composition of the present invention,
It has an excellent feature that its effect can be obtained with a relatively low coating amount. Further, this composition can improve water absorption on the felt surface with a smaller coating amount than on the wire surface.

Further, even if a coating layer containing the water absorption control composition of the present invention is provided on a newsprint base paper, no reduction in friction coefficient is observed. For example, it is generally known that an anionic styrene / acid monomer copolymer reduces the dynamic / static friction coefficient of the coated paper when the paper is coated by a size press. However, such a tendency is not recognized in the water absorption control composition of the present invention, and in particular, it is not necessary to add an anti-slip agent. The coefficient of dynamic friction of the newsprint paper of the present invention is preferably in the range of 0.40 to 0.70.

The coating liquid containing the water absorption control composition of the present invention as a main component is also excellent in suitability for a gate roll coater. For example, when the oxidized starch alone is applied by a gate roll coater, a streak pattern is considerably recognized on the coated product, whereas when the coating liquid used in the present invention is applied, Almost no streak pattern is observed, and more uniform application is possible.

Since the newsprint paper of the present invention can control the water absorption in a wide range, it can be widely applied to various inks used during printing. For example, it is conceivable to deal with special inks such as emulsion inks obtained by mixing dampening water in oil-based inks and inks with high tackiness for waterless planographic printing.

As described above, the improvement of newsprint paper is
It is more difficult than general printing paper. Therefore, it is not possible to directly transfer the technology for general printing paper to the technology for newsprint paper. However, on the contrary, it is relatively easy to transfer the technology for newsprint paper to the technology for general printing paper. Therefore, the water-absorption control composition of the present invention can be applied not only to newspaper printing paper but also to general printing paper, and similar effects (for example, improvement of water absorption) can be obtained.

By using the water-absorption control composition of the present invention, it is possible to easily produce printing papers of various brands having different size characteristics without performing internal addition size which tends to cause operational problems. Is. The surface strength of this printing paper is also improved.

[0072]

The water-absorbent control composition containing three components (components A, B, and C) as main components is applied to printing paper base paper, especially newsprint paper base paper, using a gate roll coater.
By applying in a low application amount region in the range of 05 to 1.0 g / m ² , it is possible to obtain a paper suitable for high-speed offset printing, which is excellent in water absorption and surface strength.

Regarding the reason, although the clear reason has not been clarified yet, it is presumed as follows.

It is considered that the water absorption control composition of the present invention still forms a hydrophobic complex coating capable of controlling water absorption when it is applied to a base paper and then dried. That is, component B (cationic P
AM) and component C (anionic water-soluble polymer having a hydrophobic group) form an ionic complex, and finally form a film in which the hydrophobic substituents are oriented toward the outside, and a hydrophobic surface is formed on the paper surface. It is believed that a barrier layer is obtained.

Component A (modified starch or starch)
Is useful for thinly and uniformly spreading the hydrophobic complex composed of the components B and C on the surface of the paper, and is thought to have the function of promoting the formation of the hydrophobic barrier layer and improving the surface strength. . Although it can be considered that the coating of two components, components B and C, can be performed only from the viewpoint of improving the water absorption, the use of component A makes it possible to apply components B and C more than the case of coating two components. It is possible to reduce the amount used, and it is also advantageous in terms of cost. Component B,
As described above, the component C and the component C are considered to form an ionic complex and contribute to the improvement of water absorption. From a different point of view, the component B is the component C on the paper surface.
It is also considered that (anionic water-soluble polymer having a hydrophobic group) is retained from the ionic or chemical viewpoint.

[0076]

The present invention will be described in detail below with reference to Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to these. In the description, parts and percentages indicate parts by weight and percentages by weight, respectively.

<Manufacture of newsprint base paper> DIP 35 parts,
Mix and disintegrate at a ratio of 30 parts TMP, 20 parts GP, and 15 parts KP,
The mixed pulp whose freeness was adjusted to 200 was made with a velveformer type paper machine at a paper making speed of 1000 m / min, and the basis weight was
An unsized, no-calendar newsprint base paper of 43 g / m ² was obtained. (Drip water absorption = 5 seconds)

<Synthesis of Component B> [Synthesis Example 1] Synthesis of B-1 (Cationic PAM) In a four-necked flask equipped with a reflux condenser, N, N-diethylaminoethyl methacrylate (7.8 g), 40 % Acrylamide aqueous solution (168.6 g) and water (300 g) were charged, and the mixture was heated to 60 ° C. under a nitrogen atmosphere, and then 1% ammonium persulfate aqueous solution (10 g) and 1% sodium hydrogen sulfite aqueous solution (2 g) were added to the reaction solution. In addition, the mixture was reacted at 85 ° C for 0.5 hour and then cooled to obtain a polymer (B-1). The weight average molecular weight of this polymer was 220,000.

[Synthesis Example 2] Synthesis of B-2 (cationic PAM) In a four-necked flask equipped with a reflux condenser, N, N-diethylaminoethyl methacrylate (15.6 g) and a 40% acrylamide aqueous solution (160.8 g) were added. ), And water (300g),
After heating to 60 ° C under a nitrogen atmosphere, 1% aqueous solution of ammonium persulfate (10g) and 1% aqueous solution of sodium hydrogen sulfite (2g) were added to the reaction solution, and the mixture was reacted at 85 ° C for 1 hour and then cooled, A polymer (B-2) was obtained. The weight average molecular weight of this polymer was 720,000.

[Synthesis Example 3] Synthesis of B-3 (cationic PAM) In a four-necked flask equipped with a reflux condenser, N, N-diethylaminopropylmethacrylamide (7.8 g) and 40% acrylamide aqueous solution (168.6 g) ) And water (300 g) and heated to 60 ° C under a nitrogen atmosphere, and then 1% aqueous solution of ammonium persulfate (15 g) and 1% aqueous solution of sodium bisulfite (3 g) are added to the reaction mixture at 3 ° C at 85 ° C. After reacting for a time, it was cooled to obtain a polymer (B-3). The weight average molecular weight of this polymer was 2.2 million.

[Synthesis Example 4] Synthesis of B-4 (cationic PAM) In a four-necked flask equipped with a reflux condenser, 80% methacryloyloxytrimethylammonium chloride aqueous solution (13 g) and 40% acrylamide aqueous solution (168.6) were added. g) and water (300 g), and heat up to 60 ° C under nitrogen atmosphere,
1% aqueous solution of ammonium persulfate (10 g
) And a 1% aqueous solution of sodium hydrogen sulfite (2 g) were added, and the mixture was reacted at 85 ° C. for 1 hour and then cooled to obtain a polymer (B-4). The weight average molecular weight of this polymer is
It was 650,000.

[Synthesis Example 5] Synthesis of B-5 (amphoteric PA
M) In a four-necked flask equipped with a reflux condenser, 60% methacryloyloxyethyl dimethylbenzylammonium chloride aqueous solution (22.5 g) and 40% acrylamide aqueous solution (16
0g), 80% acrylic acid aqueous solution (4.5g), and water (50g
) Was added and the mixture was heated to 60 ° C under a nitrogen atmosphere, and then 1% aqueous solution of ammonium persulfate (10 g) and 1% aqueous solution of sodium hydrogen sulfite (2 g) were added to the reaction solution at 85 ° C.
After reacting for 0.5 hour, it was cooled to obtain polymer (B-5).
I got The weight average molecular weight of this polymer was 60,000.

[Synthesis Example 6] Synthesis of B-6 (amphoteric PA
M) In a four-necked flask equipped with a reflux condenser, 60% methacryloyloxyethyldimethylbenzylammonium chloride aqueous solution (22.5 g) and 40% acrylamide aqueous solution (20
0g) and 80% acrylic acid aqueous solution (3.5g)
After heating to 60 ° C under a nitrogen atmosphere, 1% aqueous solution of ammonium persulfate (10g) and 1% aqueous solution of sodium bisulfite (2g) were added to the reaction solution, reacted at 85 ° C for 1.5 hours, and then cooled. A polymer (B-6) was obtained. The weight average molecular weight of this polymer was 1,250,000.

[Synthesis Example 7] Synthesis of B-7 (amphoteric PA
M) In a four-necked flask equipped with a reflux condenser, a 60% acrylamidopropyldimethylbenzylammonium chloride aqueous solution (23.6 g) and a 40% acrylamide aqueous solution (200
g), 80% itaconic acid aqueous solution (4.0 g), and water (30 g
) Was added and the mixture was heated to 60 ° C. under a nitrogen atmosphere, 1% aqueous solution of ammonium persulfate (10 g) and 1% aqueous solution of sodium hydrogen sulfite (2 g) were added, and the mixture was reacted at 85 ° C. for 1 hour. Upon cooling, a polymer (B-7) was obtained. The weight average molecular weight of this polymer was 820,000.

[Synthesis Example 8] Synthesis of B-8 (nonionic (weakly cationic PAM)) A four-necked flask equipped with a reflux condenser was charged with 40% aqueous acrylamide solution (177.8 g) and water (300 g). After charging and heating to 60 ° C under a nitrogen atmosphere, 1% aqueous solution of ammonium persulfate (10g) and 1% aqueous solution of sodium bisulfite (2g) were added to the reaction solution, reacted at 85 ° C for 1 hour, and then cooled. Thus, a polymer (B-8) was obtained. The weight average molecular weight of this polymer was 850,000.

[Synthesis Example 9] Synthesis of B-9 (anionic PAM) In a four-necked flask equipped with a reflux condenser, 80% acrylic acid aqueous solution (5.2 g) and 40% acrylamide aqueous solution (174.0%) were added.
g) and water (300 g), and after heating to 60 ° C under a nitrogen atmosphere, add 1% aqueous solution of ammonium persulfate (10 g) and 1% aqueous solution of sodium hydrogen sulfite (2 g) to the reaction mixture at 85 ° C. After reacting for 1 hour, cool down,
A polymer (B-9) was obtained. The weight average molecular weight of this polymer was 920,000.

<About Component C> For Component C, the following three types of polymers were used. C-1: Styrene / maleic acid copolymer weight average molecular weight = 13000 C-2: Styrene / acrylic acid copolymer weight average molecular weight = 39000 C-3: α-olefin / maleic acid copolymer weight average molecular weight = 25000 * The oxidation value of C-2 is 230.

<Production of Newsprint Paper> [Examples 1 to 20] Modified starch (oxidized starch (trade name: SK-20
/ Manufactured by Japan Corn Starch Co., Ltd.) or an etherified starch (trade name: PG-280 / Penford Products Co.) paste solution, polymer solution for component B (B-1 to B-8), A solution of the polymer for component C (C-1 to C-8) was added at a predetermined mixing ratio (see Table 1) to prepare a coating liquid (solid content concentration 7 to 15%). This coating solution was applied to the above-mentioned base paper for newsprint paper with a Mayer bar. After coating, calendering was performed to obtain a newsprint paper.

[Comparative Examples 1 to 8] A coating liquid (solid content concentration 7 to 15%) was prepared with the components shown in Table 2 and the compounding ratio thereof. This coating solution was applied to the above-mentioned base paper for newsprint paper with a Mayer bar. After coating, carry out calendar treatment,
A newsprint paper for a comparative example was obtained.

For the newspaper printing papers of Examples 1 to 20 and Comparative Examples 1 to 8, the coating amount and the water drip absorption were measured. The results are shown in Tables 1 and 2.

Measurement of coating amount: A sample (100 cm ² ) was cut, added to 50 ml of distilled water, and kept in a boiling water bath for 1 hour to extract starch. After filtering the extract, the filtrate was diluted to 100 ml, 10 ml of which was sampled,
Add 2.5 ml of 2N-hydrochloric acid and 2.5 ml of potassium iodide / iodine solution to bring the total volume to 50 ml. The absorbance at 580 nm was measured, and the amount of starch was measured from a calibration curve prepared in advance. The coating amount was obtained by back-calculating from the obtained starch amount and the compounding ratio of the coating liquid. -Measurement of drip water absorption: According to Japan TAPPI No. 33 (Testing method for water absorption rate of absorbent paper), the amount of water dropped was 1 μl.

[0092]

[Table 1]

[Table 2] [Examples 21 to 28] A coating liquid (solid content concentration 7 to 15%) was prepared with the components shown in Table 3 and the compounding ratio thereof. This coating liquid was applied to the above-mentioned base paper for newspaper printing paper with a gate roll test coater at a coating speed of 300 m / min in a predetermined coating amount range. After coating, perform super calendar processing,
I got a newspaper printing paper.

[Comparative Examples 9 to 14] A coating solution (solid content concentration 7 to 15%) was prepared with the components shown in Table 3 and the compounding ratio thereof. This coating solution was applied to the above-mentioned base paper for newsprint paper with a Mayer bar. After coating, carry out calendar treatment,
A newsprint paper for a comparative example was obtained.

For the newspaper printing papers of Examples 21 to 28 and Comparative Examples 9 to 14, the coating amount, drip water absorption, contact angle, neppar strength, surface strength A (printing strength by a Prüfbau printing tester), and surface strength. B (FRT (Fiber rising
test)) was measured. Table 3 shows the results.

Measurement of contact angle: Dynamic Absorption Tes
Using ter 1100 DAT (manufactured by Fibro), drop water volume 5 μl
The contact angle after 5 seconds was measured. -Measurement of Nappari strength: Two newspaper printing paper sheets were cut into 4 x 6 cm pieces, the coated surfaces were immersed in water at a temperature of 20 ° C for 5 seconds, and then the coated surfaces were brought into close contact with each other. Newspaper printing base paper is placed on both outer sides, passed through a roll with a pressure of 50 kg / cm ² , and at 25 ℃, 60
Humidification was performed at% RH for 24 hours. After forming a sample piece of 3 × 6 cm, the measurement was performed by a tensile tester under the condition of a tensile speed of 30 mm / min. The larger the measured value, the harder it is to peel off (in other words, the stronger the adhesiveness). In the newsprint paper of the present invention, one having a neppar strength of 25.0 g / 3 cm or less was defined as “having good peelability”. -Measurement of surface strength: Surface strength is measured by two types of methods, that is, measurement of printing strength by a Prüfbau printing tester,
And FRT (Fiber rising test) were measured, and those having good measured values were defined as “excellent in surface strength”.・ Surface strength A (printing strength with the Prüfbau printing tester) Put red ink (manufactured by Dainippon Ink & Chemicals, Inc.) on the rubber roll of the Prüfbau printing tester and print it on newspaper printing paper (printing area: 4 x 20 cm). , Printing pressure: 15N / m, Printing speed: 6.0m / s
applied with ec. The number of rising fibers when the rubber roll and the newsprint paper were peeled off during coating was measured with a microscope. The smaller the measured value, the stronger the surface strength. In the present invention, the number of rising fibers of 20 or less is defined as "excellent in surface strength".・ Surface Strength B (FRT) Newspaper printing paper is cut into a machine direction of 300 mm × width 35 mm, and a surface analysis device FIBR 1000 (manufactured by Fibro system AB)
Was used to determine the number of fluffs longer than 0.1 mm of the fiber in a constant area (1 m ² ). The smaller the measured value, the better the surface strength. In the newsprint paper of the present invention, those having 22 or less fluffs per 1 m ² were designated as “excellent in surface strength”.

[0096]

[Table 3] Regarding the dynamic / static friction coefficient, even when the water absorption control composition of the present invention was applied, it did not significantly deteriorate. For example, the newspaper printing paper of Example 21 had a dynamic friction coefficient of 0.45, a static friction coefficient of O.57, and a newspaper printing paper base paper had a dynamic friction coefficient of 0.43 and a static friction coefficient of O.56.
The dynamic / static coefficient of friction is measured by JAPAN TAPPI No.30-79.
(Paper and board friction coefficient test method) was followed.

Example 29 Oxidized Starch (SK-20), B-
A stripping component (sodium salt of alkenylsuccinic acid having 10 to 16 carbon atoms (described in JP-B-63-58960)) was added to the solution containing 4 and C-2 to prepare a coating solution. This coating solution was applied to the above-mentioned base paper for newspaper printing paper with a gate roll test coater at a coating speed of 300 m / min. After coating, super calender treatment was performed to obtain a newspaper printing paper. Mixing ratio: A: B: C: Release agent = 10: 2: 2: 0.25 Application amount: 0.30 g / m ² , Water absorption: 81 seconds, Nappari strength: 1
4.0g / 3cm Surface Strength A: 10, Surface Strength B: 16

[Example 30] Oxidized starch (SK-20), B-
1 and a solution of C-1 (used in Example 21. Mixing ratio: A: B: C = 10: 1: 1) was applied to fine paper (basis weight: 78 g / m ² , water absorption: 9). Seconds), and water was applied with a gate roll test coater at a coating speed of 300 m / min. After coating, super calendar processing was performed. Application amount: 0.32g / m ² , water absorption = 82 seconds

[Example 31] Oxidized starch (SK-20), B-
4 and C-2 (the one used in Example 23. Compounding ratio: A: B: C = 10: 2: 2) was applied to fine wood paper (basis weight: 78 g / m ² , water absorption: 9). Second), a gate roll test coater was applied at a coating speed of 300 m / min. After coating, super calendar processing was performed. Application amount: 0.40g / m ² , water absorption = 110 seconds

[Comparative Example 15] Oxidized starch (SK-20), B-
9 and a solution consisting of C-1 (used in Comparative Example 9; compounding ratio: A: B: C = 10: 5: 5) were mixed with fine paper (basis weight: 78 g / m ² , water absorption: 9). Second), a gate roll test coater was applied at a coating speed of 300 m / min. After coating, super calendar processing was performed. Application amount: 0.30g / m ² , water absorption = 9 seconds

[0101]

EFFECT OF THE INVENTION By coating the water absorption control composition of the present invention with a gate roll coater, it is possible to obtain a printing paper having improved water absorption and having well-balanced surface strength and releasability. is there. In particular, newspaper printing paper suitable for high-speed offset printing can be obtained. Further, in the newsprint paper of the present invention, the size property can be imparted only by external addition of the water-absorption control composition of the present invention without applying internal addition size, and various problems associated with internal addition of chemicals It is also possible to solve the above. Further, it is easy to support a wide variety of products by arbitrarily changing the coating amount, the compounding ratio, the type of material and the like of the water absorption control composition of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisami Satake 5-21-1 Oji, Kita-ku, Tokyo Inside Nippon Paper Industries Co., Ltd.

Claims (10)

[Claims] 1. A printing paper comprising a printing paper base paper and a coating layer containing a water-absorption control composition mainly comprising the following three components A, B and C. Component A: Modified starch or starch Component B: 1) Nonionic polyacrylamide 2) Cationic polyacrylamide (water-soluble polyacrylamide having tertiary amine group) 3) Cationic polyacrylamide (quaternary ammonium group Water-Soluble Polyacrylamide Having 4) Amphoteric Polyacrylamide At least one water-soluble polyacrylamide selected from the above 1) to 4) Component C: a monomer having a hydrophobic substituent having 6 to 10 carbon atoms and a carboxyl group Or anionic copolymer with a monomer having a sulfonic acid group 2. A newsprint paper comprising a base paper for newsprint paper provided with a coating layer containing a water-absorbent control composition mainly comprising the three components of component A, component B and component C according to claim 1. 3. The newsprint paper according to claim 2, wherein the component C according to claim 2 is a styrene / maleic acid copolymer. 4. The newspaper printing paper according to claim 2, wherein the component C according to claim 2 is a styrene / acrylic acid copolymer. 5. The component C according to claim 2 is an α-olefin / maleic acid copolymer.
Newspaper printing paper as described. 6. The newspaper printing paper according to claim 2, claim 3, claim 4, or claim 5, wherein the coating amount of the water-absorption control composition is 0.05 to 1.0 g / m ² (per side). Newsprint paper characterized by being in the range of. 7. The newspaper printing paper according to claim 2, claim 3, claim 4, or claim 5, wherein the mixing ratio of the water absorption control composition is component A: (component B + component C) = 10: 1 to 10:10, and component B: component C
= Newspaper printing paper characterized by being in the range of 40:60 to 60:40. 8. The newspaper printing paper according to claim 2, claim 3, claim 4, claim 5, or claim 6, which has a drop water absorption (Japan TAPPI No. 33, a drop water amount of 1 μl).
Newsprint paper with a) of 15 seconds to 150 seconds. 9. A printing paper comprising the water absorption control composition according to claim 1 as a coating layer on a printing paper base paper using a gate roll coater. 10. The newspaper printing paper according to claim 2, claim 3, claim 4, claim 5, claim 6, or claim 7, wherein the water-absorbent control composition is prepared using a gate roll coater. Newspaper printing paper Newspaper printing paper provided as a coating layer on the base paper.