JP3303291B2 - Surface sizing agent with improved water absorption resistance and printing paper coated with the surface sizing agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel surface sizing agent which is suitable for high-speed coating and can greatly improve the water absorption resistance and the like, and a printing paper coated with the surface sizing agent, especially newspaper printing. Regarding paper.

[0002]

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

[0003] In particular, newsprint paper (newspaper, newsprint paper) is generally made of mechanical pulp or deinked pulp (hereinafter referred to as "pulp").
“Deinked pulp” is abbreviated as “DIP”. ) Is the main type of paper, and is classified as middle or lower grade paper. On the other hand, newspaper printing ensures that the specified number of copies is printed within the specified time during the specified time period. Have to do
Paper that requires more stringent quality than ordinary printing paper.
In this regard, newsprint paper is a special type of paper, and has its own classification in terms of paper classification. Recent newsprint papers are required to be lightweight and have a high DIP content.
Various improvements need to be made while overcoming the disadvantages of these points. In that sense, the improvement of newsprint paper is a severe one that is considerably different from the improvement of general print paper.

In recent years, with respect to newspaper printing, computer systems for newspaper printing have recently been required in view of various demands (for example, a demand for high-speed printing, a demand for color space, a demand for various kinds of printing, and a demand for automation). Coupled with the time of introduction,
The transition from letterpress printing to offset printing is rapidly advancing.

The spread of offset printing requires newsprint paper to have a quality different from that of newsprint paper for letterpress printing. For example, (1) wet strength and no drainage, (2) moderate water absorption resistance, (3) low peel strength (Nepari), (4)
The quality is such that there is no generation of paper dust. Among the required qualities, particularly, retention of water absorption resistance, in other words, control of size (in other words, provision of water absorption resistance) is an important issue.

However, newsprint paper having a high mechanical pulp content and hardwood bleached kraft pulp having a low mechanical pulp content (hereinafter, "hardwood bleached kraft pulp" is referred to as "LB
KP ”. ) Is different in the degree of difficulty in controlling the water absorption resistance (in other words, imparting the water absorption resistance) to the general printing paper having a high content of ()). When the content of mechanical pulp is high, LBKP is dense while the surface of the paper is rough. Further, it is considered that the amount of application of the external additive size is large on a dense paper surface, but the amount of application of the external additive size is large on a rough paper surface.

In general printing paper, the control of the water absorption resistance is performed by, for example, a method of internally adding a chemical such as a sizing agent (internal addition size) or a method of externally adding (coating or external addition size). ing. Internal addition is a method of adding a chemical to the pulp slurry at the so-called wet end and adding the chemical to the inside of the paper at the same time as papermaking.External addition is a two-roll size press after papermaking, or This is a method of applying a chemical to the paper surface using a coating machine represented by a gate roll coater or the like. As a matter of course, a coating machine represented by a gate roll coater or the like is used for newsprint paper.

As sizing agents for internal addition, reinforced rosin sizing agents, emulsion sizing agents, synthetic sizing agents and the like are used for acidic papermaking, and alkyl ketene dimer (AKD) and alkenyl succinic anhydride are used for neutral papermaking. Things (AS
A) is known. JP-A-60-88196 and JP-A-4-363301 disclose a sizing agent comprising a cationized starch and an alkyl ketene dimer.

Further, sizing agents for external addition (also referred to as surface sizing agents) include anionic polymers such as styrene / maleic acid copolymers and styrene / acrylic acid copolymers; rosin, tall oil, and the like. Anionic low molecular compounds such as saponified alkyd resins such as phthalic acid and saponified petroleum resins and rosins; and cationic polymers such as styrene-based polymers and isocyanate-based polymers are known. These are papers having a high content of LBKP, such as general printing papers and ink-jet papers, and have different required water absorption resistance and papermaking conditions.
Hydrogenation or disproportionation by Schultz, WS, etc.
US Pat. No. 4,983,257 describes an internal sizing agent and a surface sizing agent characterized by using digested casein as an emulsifier using partially esterified fortified rosin as an emulsifier and cationized starch as an emulsifier.

On the other hand, in general, the control of water absorption resistance in newsprint papers is controlled by the internal addition of chemicals such as a sizing agent and a waterproofing agent because the content of mechanical pulp is high.

However, among the measures for controlling the water absorption resistance of newsprint paper, the method of internally adding a chemical such as a sizing agent, which is also used in general print paper (internal size), is as follows: It is necessary to add to the slurry. (2) The fixed amount of the chemical on the pulp sheet is not constant (the fixed amount of the chemical is low). (3) Usually, multiple paper machines use the common circulating white water. Therefore, papermaking that does not require water absorption resistance cannot be performed in parallel,
(4) The effect of the yield improver is not stable. If the yield is strengthened, DIP-based colored foreign matter is also incorporated into the sheet. (5) The water absorption resistance changes over time. (6) The neutralized and lightweight newspaper high-speed papermaking requires internal additive size. (7) In high-speed paper making of 1000m / min or more of newsprint paper containing 80% or more of DIP, the yield of the internal sizing agent is low. There are many problems such as a tendency to decrease, it is difficult to have water absorption resistance, and it is difficult to control the amount of chemicals added, and depending on the situation, increase or decrease the internal sizing agent and the yield improver according to the situation I needed to.

When the internal sizing agent is not effective, the internal sizing agent is excessively added, causing a decrease in paper strength, a machine trouble, and a remarkable white water stain caused by adhesion and accumulation of the hydrophobic sizing agent. There was a problem in terms of cost, quality, operability, etc.

[0013] Further, the change of the raw material composition is largely unsuitable as a temporary measure but a long-term measure, due to a large fluctuation of the raw material in an actual machine. Maintaining or improving the quality of conventional newsprint, especially in neutralized and lightweight high-speed papermaking, is an important technical issue for newsprint manufacturers.

As a measure for controlling the size of newsprint paper, a method of externally adding a chemical, in other words, a method of externally adding a surface sizing agent used in general printing paper (externally added size) is considered. However, in practice, there is a problem that a sufficient water absorption resistance effect cannot be obtained from the viewpoint of cost, and it has not been put to practical use in earnest. For example, oxidized starch is coated on newsprint base paper in an amount of 0.5 g / m ^{2 to} 1.0 g.
/ M ² , there is a problem in that the water absorption resistance of the coated product varies with the drip water absorption method described later and is about several tens of seconds.

In order to apply the surface treating agent to newsprint paper, on-machine coating is generally used from an economical point of view, and a gate roll coater which is a film formation transfer system capable of high-speed coating is used. It is common to have. The feature of this gate roll coater method is, for example,
3, No. 4 (1989) p36, Pulp and Paper Technology Times Vol. 36, No. 12
(1993) It is briefly summarized in p20, etc., compared to the conventional two-roll size press method used for general printing paper, it is possible to keep the coating liquid on the paper surface, Is effective in improving the That is,
2 In the roll-size press method, the base paper passes through the pond (liquid pool) of the coating liquid, so that the penetration of the coating liquid into the base paper is very large. Forms a film in advance, and the film is transferred, so that the coating liquid hardly permeates into the base paper.
Therefore, in the gate roll coater method, it is described that the coating material tends to remain on the base paper surface.

However, even when the water-absorbing control composition for forming a two-component ionic complex disclosed in JP-A-8-232193 on the paper surface is applied by a gate roll coater method, the drip water absorption is 10%.
In the case of newsprint base paper with a high content of unsized mechanical pulp in seconds or less, if the coating amount is 0.3 g / m ² or less on one side, it is ideal to completely prevent the coating liquid from penetrating into the base paper. It was experimentally shown that a water-absorbing barrier could not be formed on the base paper surface. Even if a surface sizing agent which is easily applied only on the surface is applied by a gate roll coater method, a sufficient size effect (effect of imparting water absorption resistance) cannot be obtained with a low application amount.

Examples of the application of such a complex to paper chemicals include, for example, Paper and Paper Technical Journal VOL. 45, No. 2, (1)
991) Pages 245 to 249 describe a method of adding a paper strength agent formed by mixing an anionic paper strength agent and a special cationic paper strength agent to form a high molecular weight ion complex to a pulp slurry. Have been. However, this method
This is a method of internally adding a chemical to a pulp slurry, and is not intended to improve water absorption resistance.
The purpose and the method are different. Also, Japanese Patent Application Laid-Open No. 60-119297 discloses a paper sizing method 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 the internal addition.

On the other hand, JP-A-52-148211 and JP-A-56
JP-A-118995 and JP-A-3-54609 disclose a surface sizing method using a coating solution containing an anionic resin and a cationic resin. JP-A-52-1
Japanese Patent No. 48211 describes a method for producing a reinforced corrugated paper for cardboard using a coating solution containing an anionic resin and a cationic resin. However, this method is mainly intended to improve the compressive strength and rigidity, and is not particularly aimed at improving the water absorption resistance. Further, in the example of this publication, the amount of applied chemical is also
It 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, a vinylidene chloride / acrylamide copolymer and polyethyleneimine. However, oil-resistant paper is paper that is required to have resistance to oil, whereas the printing paper of the present invention is compatible with ink (in other words,
This is a paper that is required to absorb oil (oil). Also, in JP-A-56-118995,
Of ketene dimer, cationized starch and anionic polymer
Although a surface sizing agent consisting of three members is disclosed, this surface sizing agent has a problem of a decrease in friction coefficient.

US Pat. No. 4,983,257 discloses a surface sizing agent comprising rosin and cationized starch, but this surface sizing agent has poor high-speed coating suitability.
There is a problem of generation of mist and bubbles.

Further, JP-A-62-122781 and JP-A-62-146674 disclose a recording material for ink jet recording having an ink receiving layer containing a polymer complex of a basic polymer and an acidic polymer. Is disclosed. However, in these publications, since both polymers are dissolved in an organic solvent such as dimethylformamide to form a coating solution, it is difficult to adapt to printing paper having a high mechanical pulp content. In addition, mechanical pulp is rarely used for inkjet paper, and base paper having a high content of bleached kraft pulp (LBKP) is used. The recording material for ink jet recording is required to have receptivity (in other words, absorptivity) with respect to the ink for ink jet composed of a water-polyhydric alcohol mixture system, which is different from the water absorption resistance required in the present invention. It is. There has been no surface sizing agent that has high-speed coating suitability and can greatly improve water absorption resistance and the like, and no printing paper, particularly newsprint paper, coated with the surface sizing agent.

[0021]

Therefore, in the present invention,
Surface sizing agent with greatly improved suitability for high-speed coating and sizing (water absorption resistance), and printing paper coated with the surface sizing agent, especially newspaper printing paper with a drip water absorption of 100 seconds or more even at a low coating amount Was provided as an issue.

[0022]

Means for Solving the Problems The above problems are mainly composed of the following three components of component A, component B and component C, or two components of component B and component C , and further components A, B and
When the ratio of component C (solid content weight ratio) is A: B: C = 0-8
Achieved by novel surface sizing agents with excellent high speed coatability in the range of 0:95 to 20: 1 to 10 . Furthermore, by providing a coating layer containing this high-performance surface sizing agent on printing paper base paper having a high content of mechanical pulp, a sufficient size effect (effect of imparting water absorption resistance) can be obtained even at a low coating amount. The present inventors have found that it is possible to achieve the object of the present invention. Component A: 1) nonionic polyacrylamide 2) cationic polyacrylamide 3) amphoteric polyacrylamide Water-soluble polyacrylamide selected from at least one of the above 1) to 3) Component B: a monomer having a hydrophobic substituent, Ammonium salt of a water-soluble anionic copolymer with a monomer having a carboxyl group Component C: at least one selected from abietic acid, dehydroabietic acid, dihydroabietic acid, pimaric acid, neopimar, isopimaric acid, levopimaric acid, and parastric acid Resin acid , or rosin containing the resin acid

Although this method can be applied to general printing paper, it is particularly effective for newsprint paper having a high content of mechanical pulp, because it is effective in a small amount. Hereinafter, newsprint paper will be described.

Even if the components A, B, and C are individually applied to the base paper of newsprint paper, the water absorption resistance, the surface strength, the suitability for high-speed coating, and the improvement of Neppari (peelability) are improved. Improvement) could not. Similarly, the effect of size and coating suitability are insufficient with only two components of components A and B or a combination of components A and C which are compositions other than the present invention. In particular, the combination of components A and C changes in fluidity and gels.

Specifically, component A, that is, nonionic polyacrylamide, cationic polyacrylamide (for example, water-soluble polyacrylamide having a tertiary amine group and / or a quaternary ammonium base), or amphoteric polyacrylamide is used. Even if applied alone, the surface strength could be improved, but the water absorption resistance could not be improved.

Further, even if the component B is applied alone, it has almost no effect of reinforcing the surface strength, generates many bubbles, and if the coating amount is not increased, water absorption resistance of 50 seconds or more can be obtained. Did not.

Furthermore, in the combination of components A and B, the water absorption resistance is insufficient with an economical addition amount, that is, a coating amount, as compared with the internal addition, and the peel strength (Nepari) of the coated product is high. The combination of components A and C is apt to gel and has a problem as a coating solution.

That is, component A, which is a composition of the present invention,
In the combination of the three components B and C, especially as a surface sizing agent for external addition, water absorption resistance and surface strength can be greatly improved. The combination of the two components B and C does not significantly improve the surface strength as compared with the combination of the three components, but can greatly increase the water absorption resistance.

Further, the present inventors have found that printing paper or newsprint base paper having a high mechanical pulp content can be prepared from three components of component A, component B and component C, or two components of component B and component C. With a surface speed of 600 m /
By applying external coating at a speed of 1 to 1800 m / min, it is possible to obtain printing paper and newsprint paper with improved water absorption resistance, high-speed coating suitability, and improved surface strength and peelability in a well-balanced manner. They have found and completed the present invention.

[0030]

DETAILED DESCRIPTION OF THE INVENTION The component A used in the surface sizing agent of the present invention is a cationic water-soluble polyacrylamide (hereinafter, "polyacrylamide" is abbreviated as "PAM"), and is a nonionic PAM, Cationic PAM,
Amphoteric PAM is included.

Nonionic PAM used as component A
As, for example, (meth) acrylamide (where,
(Meth) is used as an indication that it includes a case where meth is present, and "(meth) acrylamide" means "methacrylamide and / or acrylamide". The same applies hereinafter), a copolymer, a copolymer of a nonionic monomer copolymerizable with (meth) acrylamide and (meth) acrylamide, and the like. These PAM is essentially a nonionic, a portion of the amide structure is Amidiniumu (-CONH ₃
⁺ ) It is said to be present in the form of a slightly weak cationic. Therefore, even nonionic PAM can be used as Component A in the present invention.

The cationic PAM and the amphoteric PAM used as the component A are, in short, PAMs having a cationic monomer unit, and preferably a tertiary cation as a cationic monomer unit. PAM having a monomer unit having an amine group (or a tertiary amine base) and / or a monomer unit having a quaternary ammonium base is preferred. Basically, a PAM that does not contain an anionic monomer unit other than a cationic monomer unit is a cationic PAM, while a PAM that also has an anionic monomer unit in addition to a cationic monomer unit is an amphoteric PAM. .

If the cationic monomer unit is specifically mentioned, the monomer units represented by the general formulas [1] and [2] are more preferable.

[0034]

Embedded image

Embedded image (Here, R represents a methyl group or a hydrogen atom.
Represents NH or an oxygen atom. Z is CH ₂ CH
(OH) CH ₂ or an alkylene group having 1 to 4 carbon atoms. R ₁ , R ₂ and R ₃ represent an alkyl group having 1 to 18 carbon atoms, a benzyl group or a hydrogen atom. However, R ₁ , R ₂ and R ₃ may be the same or different. X ion represents an anion, halogen atom ion (chlorine ion, bromine ion, iodine ion, etc.), sulfate ion, alkyl sulfate ion (methyl sulfate ion, ethyl sulfate ion, etc.), alkyl sulfonate ion, aryl sulfonate ion, Represents acetate ion. )

Examples of a method for introducing a cationic monomer unit into a PAM include (a) a method for modifying various PAMs by utilizing a Mannich reaction, and (b) a method for modifying various PAMs by utilizing a Hoffman decomposition reaction. , (C) a method of copolymerizing a monomer having a tertiary amine group or a quaternary ammonium salt group, and (d) a method of copolymerizing a monomer having a tertiary amine group, followed by alkylation, arylation, etc. A method of converting to a quaternary ammonium base by a reaction and the like can be mentioned.

For example, in the method of copolymerizing (c), for example, (meth) acrylamide and a cationic monomer (a monomer having a tertiary amine group or a quaternary ammonium base), or (meth) What is necessary is just to copolymerize using an acrylamide derivative and a cationic monomer. In other words, in the present invention, it is possible to use, as the component A, a copolymer of (meth) acrylamide and a cationic monomer described below.

In this method, the monomers having a tertiary amine group used include, for example, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethyl Aminopropyl (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-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, 2-vinylpyridine, 4-vinylpyridine, 2 -Methyl
-5- vinylpyridine and the like.

On the other hand, in this copolymerization method, usable monomers having a quaternary ammonium base include:
(Meth) acryloyloxyethyltrimethylammonium chloride, (meth) acryloyloxyethyldimethylbenzylammonium chloride, (meth) acryloyloxyethyltriethylammonium chloride,
(Meth) acryloyloxyethyl diethylbenzylammonium chloride, (meth) acrylamidopropyltrimethylammonium chloride, (meth) acrylamidopropyltriethylammonium chloride,
(Meth) acrylamidopropyldimethylbenzylammonium chloride, diallyldimethylammonium chloride, diallyldiethylammonium chloride,
(Meth) acryloyloxyethyltrimethylammonium sulfate and the like can be exemplified.

In this copolymerization method, (meth) acrylamide or a monomer copolymerizable with the above-mentioned cationic monomer may be used as long as it does not interfere with the present invention. That is, in the present invention, a copolymer of (meth) acrylamide, a cationic monomer, and a copolymerizable monomer described below may be used as the component A in some cases.

The copolymerizable monomers used in this method include, for example, ethylene, butadiene, styrene, α-methylstyrene, isoprene, propylene, vinyl acetate, vinylcarbazole, vinylpyrrolidone,
(Meth) acrylonitrile, (meth) acrylate, N-methylolated (meth) acrylamide, methylenebisacrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-sulfoethyl (meth) acrylate , Ethylene di (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, vinyl benzyl sulfonium salt, vinyl benzyl phosphonium salt, etc. No. When anionic monomers such as acrylic acid and itaconic acid are used among these monomers, an amphoteric PAM can be obtained.

In the method (d) for converting a tertiary amine group to a quaternary ammonium base, the alkylating agent used includes, for example, dimethyl sulfate, methyl chloride,
Examples include methyl bromide, methyl iodide, benzyl chloride, benzyl bromide and the like.

The role of component A is to improve the ionic retention of components B and C, suitability for high-speed coating and surface strength.

As the PAM used as the component A, cationic PAM and amphoteric PAM are preferably used rather than nonionic PAM from the viewpoint of water absorption resistance control (providing water absorption resistance). This is because nonionic PAM has a small effect of imparting water absorption resistance because the cationic property derived from the amidinium structure present in a part thereof is weak. Also, cationic PAM and amphoteric PAM
In the ratio of the cationic monomer unit is 0.1
Desirably, it is at least mol%. When the ratio of the cationic monomer unit is less than 0.1 mol%, the effect of controlling the water absorption resistance tends to be slightly weakened. Furthermore, when comparing the cationic PAM and the amphoteric PAM, the cationic PAM is more preferable when high water absorption resistance is desired.

Each PAM used as the component A is prepared by subjecting the corresponding monomer to a conventionally known method, for example, an aqueous solution polymerization method, a solvent polymerization method, a reverse phase emulsion polymerization method, a precipitation polymerization method, a suspension polymerization method or the like. , Polymerization or copolymerization.

In the present invention, one kind of PA
M may be used alone, or two or more PAMs may be mixed and used.

The weight average molecular weight of PAM used as Component A of the present invention is suitably in the range of 200,000 to 4,000,000. When the average molecular weight of PAM is smaller than 200,000, such PAM cannot form a sufficient film, and the effect of imparting water absorption resistance and improving surface strength is insufficient. On the other hand, P
If the average molecular weight of the AM is greater than 4 million, such a PAM may become too viscous and cause operational problems, resulting in unsatisfactory release of the coating. Regarding the average molecular weight of the PAM used, generally, from the viewpoint of imparting water absorption resistance and surface strength,
It is preferable that "the average molecular weight is high", but conversely, it is considered that "the average molecular weight is low" is preferable from the viewpoint of the releasability of the coated product. Therefore, the average molecular weight of PAM may be appropriately determined within the above-described range according to required specifications. When considering the three factors of water absorption resistance, surface strength and releasability, the average molecular weight of the PAM used is preferably in the range of 500,000 to 2,000,000, and more preferably in the range of 700,000 to 1.2 million. is there.

Component B used in the surface sizing agent of the present invention
Is an ammonium salt of a water-soluble anionic copolymer of a monomer having a hydrophobic substituent and a monomer having a carboxyl group.

The hydrophobic substituent may be any substituent having at least 6 carbon atoms, and is not particularly limited. What is necessary is just to determine suitably according to the problem of foaming of a coating material, the degree of required water absorption resistance, etc. As the hydrophobic substituent, for example, an alkyl group having 6 or more carbon atoms, an alkenyl group having 6 or more carbon atoms, a cycloalkyl group having 6 or more carbon atoms, an aryl group having 6 or more carbon atoms, or 7 carbon atoms The above aralkyl groups are exemplified.

Examples of the monomer having a hydrophobic substituent include:
For example, styrene monomers (eg, styrene, α-
Examples thereof include methylstyrene, chlorostyrene, cyanostyrene, and the like, olefin-based monomers (for example, hexene, octene, and decene), (meth) acrylates, and maleates. Such monomers are described in detail in “Polymer Data Handbook-Fundamental Edition”, edited by The Society of Polymer Science, Baifukan (1986), etc. (For styrene-based monomers, see the table on page 47.)
5-1.For olefin monomers, see Table 1-1 on page 2.
For acrylic esters, see Table 10-1 on page 105,
Examples of maleic acid esters are given in Table 14-1 on page 162. Therefore, a monomer having a hydrophobic substituent may be selected from these.

Examples of the monomer having a carboxyl group include acrylic acid monomers (for example, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid,
Ethylacrylic acid, 3-tert-butylacrylic acid, etc.),
Maleic acid monomers (for example, maleic acid, methylmaleic acid, phenylmaleic acid, chloromaleic acid, fumaric acid, itaconic acid, muconic acid, etc.) and the like.

In this component B, the ratio of the monomer having a hydrophobic substituent to the monomer having a carboxyl group is preferably in the range of 90:10 to 40:60. At least one kind of each of a monomer having a hydrophobic substituent and a monomer having a carboxyl group may be used.

In component B, a small amount of an anionic or nonionic polymerizable with the above-mentioned monomer having a hydrophobic substituent and / or a monomer having a carboxyl group may be used in a small amount within a range not to impair the present invention. It may be polymerized.

As a method for producing the component B, for example,
Examples thereof include aqueous solution polymerization, solvent polymerization, reversed-phase emulsion polymerization, precipitation polymerization, and suspension polymerization.

Component B is an anionic hydrophilic polymer, and preferably has an acid value in the range of 50 to 500.
If it is further limited, it is desirably in the range of 100 to 300. If the acid value is less than 50, the copolymer is
Insufficient water solubility and weak interaction with component A,
Therefore, it is not preferable. On the other hand, when the acid value is larger than 500, the copolymer has too strong anionic property, which is not preferable.

Further, the component B may have a weight average molecular weight of about 0.1 to 1,000,000, and more preferably a range of 0.1 to 100,000. When the molecular weight is smaller than 0.1000, this copolymer cannot form a sufficient film, which is not preferable in terms of surface strength and water absorption resistance control. On the other hand, when the molecular weight is larger than 1,000,000, there is a possibility that an operational problem due to the high viscosity of the coating liquid may occur.

The copolymer used as the component B is, specifically, a styrene / acrylic acid copolymer, a styrene / (meth) acrylic acid copolymer, a styrene / (meth)
Acrylic acid / (meth) acrylic acid ester copolymer, styrene / maleic acid copolymer, styrene / maleic acid half-ester copolymer, styrene / maleic acid / maleic acid ester copolymer, (meth) acrylic acid / ( Examples thereof include ammonium salts such as a (meth) acrylate copolymer, an α-olefin / maleic acid copolymer, and an olefin / acrylic acid copolymer. Among them, styrene / acrylic acid copolymer, styrene / (meth) acrylic acid copolymer, styrene / maleic acid copolymer and α
-An ammonium salt of an olefin / maleic acid copolymer is more preferable in terms of imparting water absorption resistance. Further, in particular, an ammonium salt of a styrene / acrylic acid copolymer and an ammonium salt of an α-olefin / maleic acid copolymer are preferable in that the balance between the hydrophilic substituent and the hydrophobic substituent is excellent. When compared, styrene /
Most preferred are ammonium salts of acrylic acid copolymers.

The component C used in the present invention is a resin acid selected from at least one of abietic acid, dehydroabietic acid, dihydroabietic acid, pimaric acid, neopimal, isopimaric acid, levopimaric acid, and parastric acid. These mixtures may be used. Also,
The rosin referred to in the present invention is gum rosin, wood rosin, purified rosin such as tall oil rosin, and is abietic acid, dehydroabietic acid, dihydroabietic acid, pimaric acid, neopimal, isopimaric acid, levopimaric acid, A substance mainly composed of a resin acid such as parastric acid.

As described above, the surface sizing agent of the present invention is mainly composed of three components of components A, B and C, or two components of components B and C. This composition
The ratio (weight ratio) of each component of
The degree of water absorption resistance and peelability required
Degree, or depending on the amount of this composition applied,
The ratio of A, component B, and component C (A: B: C) is 0 to 80: 9.
It must be in the range of 5-20: 1-10. Also,
The ratio of component B to component C (B: C) is in the range of 100: 1 to 10
It is better if it is in the surrounding area, and considering economics
Is preferably in the range of A: B: C = 40-60: 60-40: 3-7. Even when the ratio of the component A is 0, the water absorption resistance can be improved, but the surface strength is not so improved.

The surface sizing agent used in the present invention may be basically composed of three components of component A, component B and component C, or two components of component B and component C.
May work in a relatively small amount in favor of size and peelability,
In the coating amount region described below, it is possible to obtain good sizing and releasability only with the surface sizing agent of the present invention.

The surface sizing agent of the present invention basically does not require the use of other binder-like components, but within a range that does not hinder the present invention (for example, a range that does not interfere with releasability). In some cases, such components are contained in small amounts.
As other binder-like components, for example, celluloses such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose; styrene / butadiene copolymer,
Latexes such as styrene / acrylonitrile copolymer, styrene / butadiene / acrylate copolymer; fully saponified PVA, partially saponified PVA, amide-modified PVA, carboxy-modified PVA, sulfonic acid-modified PVA
PAMs such as anionic PAM; various resins such as silicone resin, petroleum resin, ketone resin, and coumarone resin. In particular, when PVA is applied to paper, it tends to increase the adhesiveness of the paper when wet, so that when used in combination, sufficient attention must be paid to the amount of the combination.

The surface sizing agent of the present invention may be used in such a range as not to affect the present invention, such as a preservative, an antifoaming agent, an ultraviolet ray inhibitor, an anti-fading agent, a fluorescent brightener, a viscosity stabilizer, and an anti-slip agent. May be contained.

Further, the present inventors have found that the above-mentioned three components of component A, component B and component C, or two components of component B and component C are added to printing paper or newsprint base paper having a high mechanical pulp content. Component A, Component A, Component B
And the ratio of component C (solid content weight ratio) is A: B: C = 0
By providing a coating layer containing a surface sizing agent in the range of ~ 80: 95 ~ 20: 1 ~ 10 , the water absorption resistance is improved,
In addition, it has been found that printing paper and newsprint paper having improved surface strength and releasability in a well-balanced manner can be obtained.

In the present invention, the target base paper is not necessarily limited to newsprint base paper. However, in the case of newsprint base paper, the effects of the present invention are remarkably recognized. I do.

The printing paper and newsprint base paper having a high mechanical pulp content used in the present invention are ground pulp (G
P), mechanical pulp (MP) such as thermo-mechanical pulp (TMP) and semi-chemical pulp, chemical pulp (CP) represented by kraft pulp (KP), and debinding obtained by deinking waste paper containing these pulp. Ink pulp (DIP) and recovered pulp obtained by disintegrating broke from the papermaking process are used alone or in an arbitrary ratio. It is particularly effective when used as printing paper, telephone directory paper or newsprint base paper having a mechanical pulp content of 30% or more. In printing paper having a high mechanical pulp content, the effect of the present invention is remarkable because the basis weight is 37 g /
a base paper sheet forming below m ² ~43g / m ^2. Basis weight 46g
/ M ² or more, it is considered that the base paper has a sufficient surface strength, and the dimensional change of the paper due to the dampening solution during offset printing or the strength reduction is negligible. So it is not necessarily
It is not necessary to simultaneously improve both water absorption resistance and surface strength by externally adding a chemical.

On the other hand, the blending ratio of DIP in the base paper used in the present invention may be blended in an arbitrary range (0 to 100%). According to the recent trend of high blending of DIP, 30-
A range of 100% is more preferred.

This newsprint base paper may be used as required.
White carbon, clay, silica, talc, titanium oxide, calcium carbonate, synthetic resin fillers (vinyl chloride resin, polystyrene resin, urea formalin resin,
Melamine resins, styrene / butadiene copolymer resins, etc.). Especially in neutral papermaking,
Calcium carbonate is effective. Paper-strengthening agents such as polyacrylamide polymers, polyvinyl alcohol polymers, cationized starch, urea / formalin resin, melamine / formalin resin; salts of acrylamide / aminomethylacrylamide copolymers, cationized starch; It may contain a drainage / retention improver such as polyethyleneimine, polyethylene oxide, acrylamide / sodium acrylate copolymer; and an auxiliary agent such as aluminum sulfate (sulfate band), an ultraviolet inhibitor, and a fading inhibitor. However, it is necessary to add these agents in amounts that do not impair the control of the water absorption resistance of the surface sizing agent of the present invention. The physical properties of the base paper need to be such that it can be printed by an offset printing machine, and may have any properties such as tensile strength, tear strength and elongation comparable to those of ordinary newsprint paper.

The newsprint base paper may be a base paper having an internal size. However, in the present invention, there is also a meaning to solve the above-mentioned problem associated with the internal addition, and if anything, the use of base paper without the internal addition size makes the effect of the present invention more effective. be able to. That is, by externally adding the surface sizing agent of the present invention, it is possible to impart the same or higher water absorption resistance as the internally added size without performing the internally added size. For example, the surface sizing agent of the present invention can be sufficiently applied to newsprint paper of less than 10 seconds by the drip water absorption method described later.

The newsprint base paper of the present invention may be an acidic newsprint base paper or a neutral or alkaline newsprint base paper.

Two methods are known as methods for evaluating the water absorption resistance of paper having low water absorption resistance, such as newsprint paper. One method is the drip water absorption method based on Japan TAPPI No.33. This method uses 1 μm of water on paper.
This is a method of measuring the time until a water drop is absorbed by the paper surface by dropping 1. Another method is a method of measuring a contact angle (contact angle method). In the present invention, 5 μl of water is dropped and a method of measuring the contact angle of a water droplet after a lapse of a predetermined time (5 seconds) is adopted. . High water absorption resistance (water absorption resistance)
The longer the drop water absorption method, the longer the absorption time, and the longer the contact angle method, the larger the contact angle and the longer the absorption time.

By providing a coating layer containing the surface sizing agent of the present invention on the base paper of newsprint paper, it is possible to control the water absorption resistance in a wide range, for example, from 10 seconds to 1000 seconds by the drip water absorption method. Is possible. Also, in terms of the contact angle method, the water absorption resistance can be controlled by the above-described method, for example, when the contact angle is in the range of 75 to 95 degrees. That is, the water absorption resistance of the manufactured newsprint paper is changed to a predetermined water absorption resistance by changing the type of each component of the composition of the present invention, the mixing ratio of each component, the coating amount of the composition, and the like.
It can be controlled freely.

The degree of water absorption resistance of the produced newsprint may be appropriately determined according to the specifications required for the product, and is not particularly limited. But,
To limit the water absorption, the range of 20 to 1000 seconds by the drip water absorption method and the range of 80 to 95 degrees by the contact angle method are more preferable water absorption resistance.

The printing paper (especially newsprint) having improved water absorption resistance of the present invention has the surface sizing agent of the present invention externally added to one or both sides of the printing paper base paper by an on-machine coating machine. It is manufactured by

The application amount of the surface sizing agent of the present invention should be determined according to the degree of water absorption resistance required for the printing paper to be produced, and is not particularly limited. From the viewpoint of imparting properties, the composition of the present invention has a coating amount (in other words, the sum of the solid contents of the components A, B, and C) of 0.05 g / m ^{2 to} 2.0 g / m ^2.
Effective within ² (per side). If the coating amount is less than 0.05 g / m ² , the composition of the present invention cannot form a sufficient barrier layer, or cannot improve the water absorption resistance. On the other hand, when the coating amount is 2.0 g / m ²
Even if the height is higher, there arises a problem that, for example, the releasability remarkably deteriorates (a Neppari phenomenon occurs). It is also uneconomical in terms of cost. Considering the application to newsprint, it is necessary to improve the water absorption resistance, suitability for high-speed coating, surface strength improvement, and releasability in a well-balanced manner as described above. When comprehensively considered, the application amount of the surface sizing agent of the present invention (in other words, the sum of the solid contents of the components A, B, and C) is
The range of 0.1 g / m ^{2 to} 0.3 g / m ² (per side) is most desirable.

The surface sizing agent of the present invention can be used as a coating machine,
It is preferable to use a coat transfer type coater such as a gate roll coater or a blade rod metering coater. Particularly, in the case of a system using a gate roll coater, the effect is greatly exhibited. That is, as described above,
Conventionally, the surface sizing agent used in the gate roll coater method has a drawback that a sufficient water absorption resistance imparting effect and high-speed coating suitability cannot be obtained, but the surface sizing agent of the present invention has a high-speed coating suitability. Therefore, even in this method, by applying on-machine coating at a paper making speed of 600 m / min to 1800 m / min in the above-described coating amount range, mist and bubbles are less generated, and water absorption of the printing paper is efficiently performed. It is possible to improve the resistance.

The coating liquid of the present invention containing a surface sizing agent as a main component is also excellent in suitability for high-speed coating by a gate roll coater. For example, when oxidized starch is applied alone with a gate roll coater, mist and bubbles may be generated,
In the coated product, a considerably streak-like pattern is recognized. On the other hand, when the coating solution containing the surface sizing agent of the present invention as a main component is applied, generation of mist and bubbles is small, and such a streak is generated. Almost no pattern is recognized, and coating can be performed more uniformly.

Also when applied to newsprint paper, it is most desirable to apply the surface sizing agent of the present invention to a base paper of newsprint paper using a gate roll coater to perform double-side coating. It goes without saying that an on-machine coater is desirable from the viewpoint of productivity.

That is, the surface sizing agent of the present invention may be coated on the base paper of newsprint paper in a coating amount of 0.1 g / m ^{2 to} 0.3 g / m ² (per side) by a gate roll coater on both sides. .

In the case of newsprint paper, the surface of the paper is not uniform, and a water absorbing resistance barrier layer may be provided on the paper surface in a relatively low coating amount region by external addition (particularly, a gate roll coater method). It is said to be difficult. However, the surface sizing agent of the present invention has a paper making speed of 600 m /
Min. To 1800 m / min., High productivity, a relatively low coating amount, and an effect of imparting water absorption resistance.

Even if a coating layer containing the surface sizing agent of the present invention is provided on the surface of printing paper, no decrease in the coefficient of friction is observed. For example, it is generally known that an anionic styrene / acid monomer copolymer, when applied to paper by a size press, lowers the dynamic / static friction coefficient of the coated paper. However, such a tendency is not recognized in the surface sizing agent of the present invention, and it is not particularly necessary to incorporate an anti-slip agent. When applied to newsprint paper, the dynamic friction coefficient of the manufactured newsprint paper is preferably in the range of 0.4 to 0.7.

The surface sizing agent of the present invention can improve the water absorption resistance with a smaller amount of application on the felt surface than on the wire surface.

Newsprint paper using the surface sizing agent of the present invention can control the water absorption resistance in a wide range, so that it can be widely used for various inks used in printing. For example, special inks such as emulsion ink in which dampening water is mixed into oil-based ink, and inks having high tackiness for lithographic printing without water can be considered.

As described above, the improvement of newsprint paper is as follows.
Difficult compared to general high quality printing paper. For this reason, it is impossible to directly convert the technology for general printing paper to the technology for newsprint paper. However, on the contrary, it is relatively easy to convert the technology for newsprint paper to the technology for general print paper. Therefore, the surface sizing agent of the present invention can be applied not only to newsprint paper but also to general print paper, and has the same effect as that of newsprint paper (for example, improvement of water absorption resistance, surface Strength improvement, etc.).

By using the surface sizing agent of the present invention, it is possible to easily produce printing papers of various types of brands having different water absorption resistances without using an internal size that easily causes operational problems. is there. Also, this printing paper is
The surface strength has also been improved at the same time.

[0084]

[Action] Fast coating for sizing agents of the present invention (surface sizing agent), the printing base ^{paper, 0.05g / m 2 ~2.0 g /} m 2
By applying a coating amount in the range (per one side) with a gate roll coater or the like, it is possible to obtain a paper having improved water absorption resistance. 0.1 g / m ^{2 to} 0.3 g /
the coating amount region ranging m ² (per one side), by coating by a gate roll coater or the like, water resistance, surface strength and peeling of the three parties newsprint which is suitable for high-speed offset printing with good balance improved You can get the paper.

Although the clear reason has not been elucidated yet, it is presumed as follows.

When the surface sizing agent of the present invention is applied to base paper and then dried, component A controls the permeability. On the other hand, component B and component C control the hydrophobicity. Further, it is considered that the components A, B, and C are for forming a hydrophobic complex coating capable of controlling water absorption resistance. That is, component A (cationic PAM), component B (anionic water-soluble polymer having a hydrophobic group), and component C (hydrophobic compound having an anionic substituent) form an ionic complex and a hydrophobic compound. Forming a complex, eventually forming a coating with the hydrophobic substituents oriented outward,
It is believed that a hydrophobic barrier layer is obtained on the paper surface. That is, in the web drying step, the component C and the component B form a strong hydrophobic complex (styrene group and abietic acid skeleton) through the deammonification process by heating, and further promote improvement of water absorption resistance. From the viewpoint of hydrophobicity alone, it is considered that the water absorption resistance can be improved only by the component B and the component C. However, the component A causes the component B and the component C to be ionic,
Alternatively, it is considered that even a small amount works very effectively in forming a film (in other words, improving water absorption resistance) because it is effectively retained from a chemical aspect.

It is considered that the component A greatly contributes to improvement of surface strength in addition to ionic retention performance and high-speed coating suitability.

[0088]

EXAMPLES The present invention will be described below with reference to synthesis examples and examples, but the present invention is not limited to these examples. In the description, parts and percentages indicate parts by weight and percentage by weight, respectively.

<Synthesis of Various PAMs: Component A> [Synthesis Example 1] Synthesis of A-1 In a four-necked flask equipped with a reflux condenser, N, N-dimethylaminoethyl methacrylate (7.8 g), 40% Acrylamide aqueous solution (168.6 g) and ion-exchanged water (300 g)
After heating to 60 ° C under a nitrogen atmosphere, a 1% aqueous solution of ammonium persulfate (10 g) and a 1% aqueous solution of sodium hydrogen sulfite (2 g) were added to the reaction solution, and the mixture was reacted at 85 ° C for 1 hour, and then cooled. Thus, a polymer (A-1) was obtained. The weight average molecular weight of this polymer was 740,000.

Synthesis Example 2 Synthesis of A-2 In a four-necked flask equipped with a reflux condenser, 80% methacryloyloxyethyltrimethylammonium chloride (7.
8 g), a 40% aqueous acrylamide solution (168.6 g) and ion-exchanged water (300 g) were charged and heated to 60 ° C. under a nitrogen atmosphere, and the reaction mixture was added with a 1% aqueous solution of ammonium persulfate (10 g) and sodium hydrogen sulfite 1 % Aqueous solution (2 g)
After reacting at 85 ° C. for 1 hour, the mixture was cooled to obtain a polymer (A-2). The weight average molecular weight of this polymer was 740,000.

Synthesis Example 3 Synthesis of A-3 In a four-necked flask equipped with a reflux condenser, 80% methacryloyloxyethyltrimethylammonium chloride (5.
2 g), a 40% aqueous solution of acrylamide (174.0 g) and ion-exchanged water (300 g) were charged and heated to 60 ° C. under a nitrogen atmosphere, and the reaction mixture was added with a 1% aqueous solution of ammonium persulfate (10 g) and sodium hydrogen sulfite 1 % Aqueous solution (2 g)
After reacting at 85 ° C. for 1 hour, the mixture was cooled to obtain a polymer (A-3). The weight average molecular weight of this polymer was 1.04 million.

Synthesis Example 4 Synthesis of A-4 In a four-necked flask equipped with a reflux condenser, 60% acrylamidopropyldimethylbenzylammonium chloride (9.4 g), 40% acrylamide aqueous solution (174.0 g) and ion-exchanged water (300 g), 60 ℃ under nitrogen atmosphere
After heating to room temperature, a 1% aqueous solution of ammonium persulfate (10 g) and a 1% aqueous solution of sodium hydrogen sulfite (2 g) were added to the reaction mixture.
g) was added and reacted at 85 ° C. for 1 hour, and then cooled to obtain a polymer (A-4). The weight average molecular weight of this polymer was 1.05 million.

Synthesis Example 5 Synthesis of A-5 In a four-necked flask equipped with a reflux condenser, 60% acrylamidopropyldimethylbenzylammonium chloride (9.4 g), itaconic acid (2.6 g), and 40% acrylamide aqueous solution ( 170.4 g) and ion-exchanged water (300 g) were charged and heated to 60 ° C. under a nitrogen atmosphere. To the reaction solution, a 1% aqueous solution of ammonium persulfate (10 g) and a 1% aqueous solution of sodium bisulfite (2 g) were added. After reacting at 85 ° C. for 1 hour, the mixture was cooled to obtain a polymer (A-5). The weight average molecular weight of this polymer was 560,000.

<Anionic Copolymer Having Hydrophobic Substituent: Regarding Component B> For component B, aqueous solutions of ammonium salts of the following three types of polymers were used. B-1: Styrene / maleic acid copolymer weight average molecular weight = 1700 B-2: Styrene / maleic acid copolymer weight average molecular weight = 13000 B-3: Styrene / acrylic acid copolymer weight average molecular weight = 39000 (oxidation Value = 230)

<Preparation of Coating Solution: Component A + Component B + Component C> Aqueous solutions of various synthesized PAMs (Component A) corresponding to the present invention and an aqueous ammonia solution of an anionic copolymer having a hydrophobic substituent (Component B) , And a resin acid (component C) in a predetermined ratio and dissolving, whereby a coating stock solution of the coating sizing agent of the present invention can be easily prepared. A coating solution that produces an emulsified solution or an insoluble precipitate upon mixing is not preferred in the present invention and may gum up while passing through a roll for an extended period of time.

<Manufacture of newsprint base paper> DIP (deinked pulp) 35 parts, TMP (thermomechanical pulp) 30
Parts, 20 parts of GP (ground pulp) and 15 parts of KP (kraft pulp). The mixed pulp having a freeness adjusted to 200 was made at a papermaking speed of 1050 m / min using a Berbe-former type paper machine. An unsized, no-calendar newsprint base paper was obtained. This base paper has a basis weight of 43 g /
m ² , density 0.65, whiteness 51%, smoothness 60 seconds, static coefficient of friction
The paper quality (for example, strength) other than water absorption resistance was 0.45 and the coefficient of kinetic friction was 0.56. The base paper did not contain an internal sizing agent, and had a water absorption resistance of 5 to 7 seconds as measured by a drip absorptivity method.

<Manufacture of Newsprint Paper> [Examples 1 to 6] PA having cationic properties as A component
An aqueous solution of an ammonium salt of a styrene-acrylic acid polymer (B-3) as a component B was added to the aqueous solution (A-3) of M.
The mixing ratio is 1: 1 (solid content weight ratio). Further, as the C component, C-1: abietic acid, C-2: dehydroabietic acid, and C-3: heartlurosin are the total of the components A and B. Was added to 5%, mixed, dissolved and diluted to prepare a coating solution (solid content: 1 to 4%). Also,
C-1: abietic acid, C-2: dehydroabietic acid, and C-3: heartle rosin were added to an aqueous solution of the styrene / acrylic acid polymer (B-3) in an amount of 5% based on the total amount of B, and mixed and dissolved. To prepare a coating solution. The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using a Meyer bar. After the application, a super calendar treatment was performed to obtain newsprint paper.

[Comparative Example 1] A styrene-acrylic acid polymer (B) was added to an aqueous solution of cationic PAM (A-2).
The ammonium aqueous solution of -3) was added at a mixing ratio of 1: 1 (weight ratio of solid content), mixed, dissolved and diluted to prepare a coating solution. The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using a Meyer bar. After the application, a super calendar treatment was performed to obtain newsprint paper.

Comparative Example 2 A solution of rosin emulsion (trade name: Sizepine NTS-45, manufactured by Arakawa Chemical Co., Ltd.) was adjusted to a predetermined concentration to prepare a coating solution. The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using the Meyer bar, and the obtained coating liquid was applied to the F side of the aforementioned newsprint base paper. After the application, a super calendar treatment was performed to obtain newsprint paper.

Comparative Example 3 Rosin Emulsion (trade name: Sizepine SPN-773, manufactured by Arakawa Chemical Co., Ltd.)
Was adjusted to a predetermined concentration to obtain a coating solution. The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using the Meyer bar, and the obtained coating liquid was applied to the F side of the aforementioned newsprint base paper. After the application, a super calendar treatment was performed to obtain newsprint paper.

Comparative Example 4 A solution of rosin emulsion (trade name: Sizepine NT-80, manufactured by Arakawa Chemical Co., Ltd.) was adjusted to a predetermined concentration to prepare a coating solution. The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using the Meyer bar, and the obtained coating liquid was applied to the F side of the aforementioned newsprint base paper. After the application, a super calendar treatment was performed to obtain newsprint paper.

Comparative Example 5 An aqueous solution of cationic PAM (A-3) was diluted to prepare a coating solution. The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using a Meyer bar. After the application, a super calendar treatment was performed to obtain newsprint paper.

Comparative Example 6 An aqueous solution of an ammonium salt of a styrene-acrylic acid polymer (B-1) was diluted to prepare a coating solution. The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using a Meyer bar. After the application, a super calendar treatment was performed to obtain newsprint paper.

Comparative Example 7 A coating solution was prepared by diluting an aqueous ammonium solution of a styrene-acrylic acid polymer (B-2). The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using a Meyer bar. After application,
Super calendar processing was performed to obtain newsprint paper.

[Comparative Example 8] A coating solution was prepared by diluting an aqueous ammonium solution of a styrene-acrylic acid polymer (B-3). The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using a Meyer bar. After application,
Super calendar processing was performed to obtain newsprint paper.

Comparative Example 9 Abietic acid (C-1) was dissolved in a dilute aqueous ammonium solution and diluted to prepare a coating solution. The obtained coating solution was coated with F
The surface was coated using a Mayer bar. After the application, a super calendar treatment was performed to obtain newsprint paper.

Comparative Example 10 Dehydroabietic acid (C
-2) was dissolved in a dilute aqueous ammonium solution and diluted to prepare a coating solution. The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using a Meyer bar. After the application, a super calendar treatment was performed to obtain newsprint paper.

[Comparative Example 11] Heartle rosin (C-3)
Was dissolved in a dilute aqueous ammonium solution and diluted to prepare a coating solution. The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using a Meyer bar. After application,
Super calendar processing was performed to obtain newsprint paper.

[Comparative Example 12] PA having cationic properties
Abietic acid (C-1) was added to the aqueous solution of M (A-3) in an ammonium aqueous solution at 10% with respect to the component A , mixed, dissolved, diluted and added to prepare a coating solution. The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using a Meyer bar. After the application, a super calendar treatment was performed to obtain newsprint paper.

Comparative Example 13 PA Having Cationicity
Dehydroabietic acid (C-2) was added to the aqueous ammonium solution of the aqueous solution of M (A-3) at 10% with respect to the component A , mixed, dissolved, diluted and added to prepare a coating solution.
The obtained coating liquid is applied to the F side of the aforementioned newsprint base paper,
It was applied using a Mayer bar. After the application, a super-calender treatment was performed to obtain newsprint paper.

[Comparative Example 14] PA having cationic property
Was added 10% Hatorurojin the aqueous solution of ammonium M aqueous solution of (A-3) a (C-3) with respect to component A, mixing was dissolved, it was added and diluted to prepare a coating solution. The obtained coating liquid was applied to the F side of the aforementioned newsprint base paper using a Meyer bar. After the application, a super calendar treatment was performed to obtain newsprint paper.

With respect to the newsprint papers of Examples 1 to 6 and Comparative Examples 1 to 14, the following items were examined, and the results are shown in Table 1.
It was shown to. Foamability: After the coating solution was stirred for 1 minute with a mixer, the amount of foam generated was evaluated as Δ: small, Δ: slightly large, ×: large. -Coating aptitude: Coatability in the Meyer bar: 〇: good, △: somewhat good, ×: bad, gelation: no fluidity,
Was evaluated. -Measurement of drop water absorption: Measured with a dropping water volume of 1 µl according to Japan TAPPI No. 33 (Testing method for water absorption rate of absorbent paper). In the drip water absorption, "> 1200 indicates that the drip water absorption is 1200 seconds or more."

[0113]

[Table 1] [Example 7] Aqueous solution of cationic PAM (A-
4) an aqueous solution of an ammonium salt of a styrene-acrylic acid polymer (B-3), and further an aqueous solution of dehydroabietic acid (C
-2) was added at a mixing ratio of 1: 1: 0.05 (solids weight ratio), dissolved and diluted to prepare a coating liquid having a solids concentration of 2.82%. The obtained coating liquid was applied to the F side of newsprint base paper (basis weight: 43 g / m ² , drip water absorption: 9 seconds) using a gate roll coater. No mist was generated even with a gate roll coater coating at 1050 m / min. After the application, a super calendar treatment was performed to obtain newsprint paper.

Example 8 A styrene-acrylic acid polymer (B) was added to an aqueous solution of a cationic PAM (A-5).
-3) An aqueous solution of an ammonium salt is added at a mixing ratio of 1: 1 (weight ratio of solids), and gum rosin is further added to components A and B.
Was added, and mixed, dissolved and diluted to prepare a coating solution having a solid concentration of 3.0%. The obtained coating liquid was applied to the F side of the base paper for newsprint used in Example 7 using a gate roll coater in the same manner as in Example 7. After the application, a super calendar treatment was performed to obtain newsprint paper.

[Comparative Example 15] PAM having cationic property
Aqueous solution (A-4) was mixed with an aqueous solution of ammonium salt of styrene-acrylic acid polymer (B-3) at a mixing ratio of 1: 1.
(Weight ratio of solid content), mixed, dissolved and diluted to prepare a coating solution having a solid content concentration of 2.90%. The obtained coating solution was applied onto the F side of the base paper for newsprint paper used in Example 7 to obtain Example 7.
Using a gate roll coater in the same manner as described above. Ten
No mist was generated at all even with a 50 m / min gate roll coater coating. After the application, a super calendar treatment was performed to obtain newsprint paper.

[Comparative Example 16] Oxidized starch (trade name: S
K-20, manufactured by Nippon Cornstarch Co., Ltd.) and an aqueous solution of a styrene / acrylic acid-based surface sizing agent (trade name: Coropearl M-150-9, manufactured by Seiko Chemical Co., Ltd.) was added to the paste liquid of blending ratio 5 : 2 (solid weight ratio)
A 6.0% coating solution was prepared. The obtained coating solution was used in Example 7
Was applied using a gate roll coater in the same manner as in Example 7 on the F side of the newsprint base paper used in the above. However, foaming of the coating material during gate roll coating was remarkable, and there was a problem in coating suitability. After the application, a super calendar treatment was performed to obtain newsprint paper.

Comparative Example 17 A paste solution of cationized starch (trade name: CATO 302, manufactured by National Starch and Chemical Co., Ltd.) was added to an aqueous solution of sodium salt of polymaleic acid, and an alkyl ketene dimer (trade name: A)
-8, manufactured by Arakawa Chemical Industry Co., Ltd.)
1: 1 (weight ratio of solid content) was added to prepare a coating solution having a solid content of 5.5%. The obtained coating solution was applied to the F side of the base paper for newsprint paper used in Example 7 using a gate roll coater in the same manner as in Example 7.
However, foaming of the coating material during coating was remarkable, and coating with a gate roll coater for a long time could not be performed. The coated product obtained by the coating in a short time was subjected to a super calendar treatment to obtain a newspaper printing paper.

The following items were measured for the newsprint papers of Examples 7 to and Comparative Examples 15 to 17, and the results are shown in Table 2.

Measurement of coating amount: The nitrogen content was determined by the Kjeldahl method and converted.・ Drip water absorption measurement: Japan TAPPI No.3 as described above
Followed 3. In addition, in the drip water absorption, "> 300 is
The drip water absorption is 300 seconds or more. "・ Measurement of contact angle: As described above, dripping with 5 μl of dropping water
The contact angle after 5 seconds was measured.・ Measurement of Nepari strength: Newspaper printing paper 4 cm x 6 cm
The coated surfaces were immersed in water at a temperature of 20 ° C. for 5 seconds, and the coated surfaces were brought into close contact with each other. Newsprint paper base paper is laid on both outer sides and passed through a roll with a pressure of 50 kg / m ² ,
The humidity was controlled at 60 ° C and 60% RH for 24 hours. After forming a sample piece of 3 × 6 cm, the measurement was performed with a tensile tester at a tensile speed of 30 mm / min. The larger the measured value, the more difficult it is to peel off (in other words, the stronger the adhesiveness). The newsprint paper of the present invention has a Neppari strength of 15.0 g.
A sample having a size of / 3 cm or less was regarded as "having good releasability". "Tear." Means that when the sample was peeled off by the tensile tester, the peeling did not occur on the bonding surface, and the delamination phenomenon of the sample itself occurred. In other words, it means that the adhesiveness is so high that it cannot be measured by this measuring method.・ Surface strength measurement: Surface strength is measured in two different ways: measurement of print strength by a Prüfbau printing tester,
And FRT (Fiber rising test) were measured, and those with both good measured values were determined to be "excellent in surface strength". Surface strength A (printing strength by the Prüfbau printing tester) Red ink (manufactured by Dainippon Ink and Chemicals, Inc.) is placed on a rubber roll of the Prüfbau printing tester and printed on newsprint paper (printing area: 4 cm x 20 cm). The coating was performed at a pressure of 15 N / m and a printing speed of 6.0 m / sec. The number of rising fibers when the rubber roll and the newsprint were peeled off at the time of coating was measured with a microscope. The smaller the measured value, the higher 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) Newsprint paper is cut to 300 mm x 35 mm in width in the machine direction, and the surface analysis device FIBR 1000 (Fibro system AB)
0.1% of fiber in a fixed area (1 m ² )
The number of fluffs longer than mm was determined. The smaller the measured value, the better the surface strength. In the newsprint paper of the present invention, a sheet having 22 or less fuzz per m ² was defined as “excellent in surface strength”.

[Table 2] <Application to General Printing Paper> [Example 9] Aqueous solution of cationic PAM (A-
To 1), an aqueous solution of an ammonium salt of a styrene-acrylic acid polymer (B-3) and abietic acid were added, and the mixture was added so that the mixing ratio became 1: 1: 0.01 (solid content weight ratio).
It was dissolved and diluted to prepare a coating solution having a solid content of 2.8%. The obtained coating solution was applied to high quality paper (basis weight: 78 g / m ² , drip water absorption: 9 seconds) using a gate roll coater.
Applied. No mist was generated even with a 1200 m / min gate roll coater coating. After the application, a super calendar treatment was performed to obtain a printing paper. The coating amount: 0.20 g / m ² infusion water absorbency:> 300 seconds, the contact angle: 91 degrees, the surface strength A: 17,
Surface strength B: 19

[Example 10] PAM having cationic property
To the aqueous solution (A-4) of the above, an aqueous solution of an ammonium salt of a styrene-acrylic acid polymer (B-3), and dehydroabietic acid were added so that the blending ratio became 1: 1: 0.01 (solid content weight ratio). The solid was dissolved and diluted to prepare a coating solution having a solid content of 2.8%. The obtained coating solution is applied to a high quality paper (basis weight:
78 g / m ² , drip water absorption: 9 seconds) using a gate roll coater. No mist was generated at all even with a 1200 m / min gate roll coater coating. After the application, a super calendar treatment was performed to obtain a printing paper. The coating amount: 0.22 g / m ² infusion water absorbency:> 300 seconds, the contact angle: 92 degrees, the surface strength A: 17,
Surface strength B: 19

[0121]

According to the development of a new high-speed coating sizing agent having a prescription of three or two components, a high sizing effect can be obtained with a small application amount. By applying the high-speed coating sizing agent (surface sizing agent) of the present invention with a gate roll coater, the water absorption resistance is greatly improved,
In addition, it has become possible to obtain printing paper having a good balance of surface strength and releasability by high-speed papermaking. In particular, newsprint paper suitable for high-speed offset printing is obtained. Further, in the newsprint paper of the present invention, the water-absorbing resistance can be imparted only by externally adding the high-speed coating sizing agent (surface sizing agent) without the internal sizing. It is also possible to solve various problems associated with the internal addition of. Furthermore, by arbitrarily changing the application amount, blending ratio, material type, etc. of the sizing agent for high-speed coating (surface sizing agent) of the present invention, it is easy to cope with a wide variety of products at a lower cost than the internal addition system. is there.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Yukiko Uebori 5-2-1-1, Oji, Kita-ku, Tokyo Nippon Paper Industries Co., Ltd. Central Research Laboratory (56) References JP-A-7-119077 (JP, A) JP-A-3-17492 (JP, A) JP-A-8-246391 (JP, A) JP-A-8-120592 (JP, A) JP-A-55-62297 (JP, A) (58) (Int.Cl. ⁷ , DB name) D21H 19/20 D21H 19/10 D21H 21/16

Claims (14)

(57) [Claims] 1. A composition mainly comprising three components consisting of components A, B and C shown below, or two components consisting of components B and C, and the ratio of components A, B and C (solids weight ratio) ) Is in the range of A: B: C = 0-80: 95-20: 1-10. Component A: 1) nonionic polyacrylamide 2) cationic polyacrylamide 3) amphoteric polyacrylamide Water-soluble polyacrylamide selected from at least one of the above 1) to 3) Component B: a monomer having a hydrophobic substituent, Ammonium salt of a water-soluble anionic copolymer with a monomer having a carboxyl group Component C: at least one selected from dehydroabietic acid, abietic acid, dihydroabietic acid, pimaric acid, neopimal, isopimaric acid, levopimaric acid, and parastric acid Resin acid, or rosin containing the resin acid 2. A printing paper base paper comprising three components comprising component A, component B and component C according to claim 1 or component B.
And component C, and component A and component B
And the ratio of component C (solid content weight ratio) is A: B: C = 0
Printing paper provided with a coating layer containing a surface sizing agent in the range of from 80:95 to 20: 1 to 10. 3. A newsprint base paper mainly comprising three components consisting of component A, component B and component C, or two components consisting of component B and component C according to claim 1, wherein component A, component B and component When the ratio of C (solids weight ratio) is A: B: C =
Newsprint paper provided with a coating layer containing a surface sizing agent in the range of 0 to 80:95 to 20: 1 to 10. 4. The printing paper according to claim 2, wherein the component A, one of the components constituting the surface sizing agent, is a cationic or amphoteric having a tertiary amine group and / or a quaternary ammonium base. A surface sizing agent characterized by being polyacrylamide. 5. The newsprint paper according to claim 3,
Be those newsprint base paper was lighter in a range of basis weight ^{37g / m 2 ~43g / m 2} , Component A is one of the components constituting the surface sizing agent, tertiary amine groups and / or the 4th
Newsprint paper characterized by being a cationic or amphoteric polyacrylamide having a quaternary ammonium base. 6. The newsprint paper according to claim 3,
Lightweight newsprint base paper in the range of basis weight ^{37g / m 2 ~43g / m 2} , and be one obtained by internally added calcium carbonate, component is one of components constituting the surface sizing agent A
Is a cationic or amphoteric polyacrylamide having a tertiary amine group and / or a quaternary ammonium base. 7. A newsprint paper according to claim 3 wherein the, be those newsprint base paper is lighter in the range of basis weight ^{37g / m 2 ~43g / m 2} , containing DIP 80 wt% or more, Component A, which is one of the components constituting the surface sizing agent, is the third component.
Newsprint paper characterized by being a cationic or amphoteric polyacrylamide having a tertiary amine group and / or a quaternary ammonium base. 8. The surface sizing agent according to claim 1, wherein the component B, which is one of the components constituting the surface sizing agent, comprises ammonium of a styrene monomer and an acrylic acid monomer. A surface sizing agent, which is a water-soluble anionic copolymer. 9. The newsprint paper according to claim 6, wherein
Newsprint paper characterized in that the main component of the component C, one of the components constituting the surface sizing agent, is abietic acid or dehydroabietic acid. 10. The newspaper printing paper according to any one of claims 3, 5, 6, or 7, wherein the drip water absorption (according to Japan TAPPI No. 33,
Newspaper printing paper characterized in that (measured in 1 μl) is in the range of 20 seconds to 1000 seconds. 11. The newsprint paper according to claim 3, wherein the contact angle (measured after 1 second with a drop water volume of 5 μl) is determined.
Newsprint paper characterized by being in the range of 80 to 95 degrees. 12. The newsprint paper according to claim 3, wherein the amount of the surface sizing agent applied is 0.1 to 0.3.
g / m ² (per side) in newspaper printing paper. 13. The surface sizing agent according to claim 1, wherein the pH of the surface sizing agent is in the range of 9-11. 14. The newsprint paper according to claim 3, claim 5, claim 6, claim 7, claim 9, claim 10, or claim 11, wherein the surface sizing agent is coated by a gate roll coater method. Newsprint paper characterized by being processed.