JPH0625996A - Base paper for offset printing coated paper - Google Patents

Abstract

PURPOSE:To obtain base paper for offset printing coated paper having excellent folding endurance and improved in blister resistance using an inexpensive material by adding specific amounts of cationic starch and polyacrylamide to pulp and making the mixture into paper. CONSTITUTION:0.3-1.5wt.% cationic starch and 0.1-1.0wt.% acrylamide based on oven-dry weight of pulp are added to pulp and further, light calcium carbonate, aluminium sulfate and a yield improver are added thereto and the mixture is made into paper by a Fourdrinier multicylindrical drier type paper machine, etc., and starch and an additive sizing agent are applied to the resultant paper and the paper is dried to provide objective base paper for offset printing having >=40g/m<2> oven-dry basis weight and excellent blister resistance and folding strength. This base paper is used in order to produce coated paper for offset printing by applying a coating liquid consisting essentially of a pigment and an adhesive to both sides of the base paper in an amount of 6g/m<2> (oven-dry weight) per one side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of a coated paper for offset printing, which comprises coating a coating liquid containing a pigment and an adhesive as a main component on one or both sides of a base paper made of cellulose pulp using a coater. Regarding the base paper used for. More specifically, the present invention relates to a base paper for producing a coated paper for printing which has excellent folding cracking strength and improved blister resistance.

[0002]

2. Description of the Related Art In recent years, the importance of printed matter has been re-recognized as a medium for publication, advertisement, etc., and visualization, colorization, and high quality of printed matter have been promoted. Demand for coated paper) is increasing.
In particular, there is a great demand for coated paper for offset printing, which is most widely used for multicolor printing.

In offset printing, ink is not directly printed on a plate, but is transferred to a rubber surface called a blanket, printed on the blanket, and then dried to produce a printing paper. Conventionally, as a raw material for base paper of coated paper for offset printing, conifer bleached kraft pulp (N
BKP) and hardwood bleached kraft pulp (LBKP) have been used, but recently, for the purpose of cost reduction, improvement of opacity, recycled use of pulp, etc., high-yield pulp, deinked waste paper pulp made from waste paper It is well known that has come to be used.

Paper-strengthening agents and sizing agents are used in the coated base paper depending on the intended use. For the purpose of improving the strength such as the interlaminar strength of the coated base paper, cationized starch and polysulfate are used. Acrylamide is mainly used, and for the purpose of improving the size property, alkyl ketene dimer size, alkenyl succinic anhydride size, and rosin size are mainly used. Starch, polyvinyl alcohol, etc. are coated with a device such as a gate roll.

In the offset printing, after printing water and ink on the surface of the paper, the paper is rapidly dried at 115 to 125 ° C. to obtain a printed paper. However, when offset printing is applied to the coated paper, the coated paper is dried and dried at a high temperature. There has been a problem that the value of the printing paper is reduced since the water contained in the base paper evaporates and the coating layer swells, so-called “blistering” occurs.

As a method for improving the blistering of coated paper, conventionally, a method of increasing the strength against the force applied in the thickness direction of the coated base paper, that is, the interlayer strength has been taken. The interlayer strength of the coated base paper is adjusted by increasing or decreasing the addition ratio of the paper strengthening agent. The method of adjusting by changing is common.

On the other hand, as the basis weight of the coated base paper constituting the coated paper increases, the water content of the coated paper also increases, so that blistering is more likely to occur during offset printing, and this blistering is prevented. Therefore, the addition rate of the cationized starch added to the coated base paper has to be further increased. However, even if the interlayer strength of the coated base paper reaches a desired level by increasing the addition rate of cationized starch,
The coated base paper became hard and the breaking strength of the coated paper was significantly reduced.

The coated paper is often used as a product such as a book, a cover of a magazine or a paper of an art print book by folding it. There is a problem that when the coated paper causes a decrease in fold cracking strength, tears occur at the folds of a book or magazine, which significantly reduces the value of the product.

As described above, when the interlayer strength of the coated base paper is increased to suppress the occurrence of blistering for offset printing, the folding crack strength of the coated paper tends to decrease. Although cracking strength is an important quality of coated paper, it has a trade-off relationship in producing coated paper.

On the other hand, without using cationized starch,
It is difficult to improve both the blister resistance and the crease resistance at the same time by using other paper strengthening agents to increase the interlaminar strength of the coated paper. There is also a problem that the cost of the strength enhancer is high and the economical efficiency in manufacturing coated paper is deteriorated.

[0011]

DISCLOSURE OF THE INVENTION The inventors of the present invention have found that the water content of the coated paper, the air permeability, the interlaminar strength, the basis weight and the coating amount, and the resistance to blistering during offset printing (blister resistance). , And the relationship between the breaking strength and the type and effect of the paper strengthening agent for coated base paper were studied.

In order to improve the blister resistance of the coated paper for offset printing, it is most effective to increase the interlayer strength of the coated base paper, and the effect of improving the interlayer strength by the cationized starch is high.

However, with only cationized starch, the coated base paper has an absolute dry weight of 40 g / m ² or more and a coating liquid of 6 g / m ² (per side, absolute dry) or more. There is a limit to the effect of improving the blister resistance (interlayer strength) of coated paper for offset printing, and if the addition rate of cationized starch (absolute dry weight of pulp constituting the coating base paper) exceeds a certain range, the interlaminar strength It was found that not only further improvement cannot be expected, but also the coated paper loses elasticity and becomes hard, and the folding crack strength is significantly reduced.

The present invention is excellent in the case where the absolute dry rice weight is 40 g / m ² or more and the coating liquid is applied in an amount of 6 g / m ² (per side, absolute dry) or more to form a coated paper. The purpose of the present invention is to provide a base paper for coating which is capable of giving a coated paper for offset printing having a blister resistance (interlayer strength) and an excellent folding crack strength, and in particular, a cationized starch is used for improving the blister resistance. The purpose is to provide the coated base paper used.

[0015]

DISCLOSURE OF THE INVENTION The inventors of the present invention have ensured blistering resistance and crease resistance of coated base paper with respect to the coated rice paper having an absolutely dry basis weight and a coating amount exceeding a certain range. In order to produce a coated paper that is low in the cost of producing paper and excellent in economic efficiency, it is essential to add a fixed amount of a cationized starch and another strength enhancer together in the production of the coated base paper, and We have found that polyacrylamide is effective as another paper strengthening agent and completed the present invention.

According to the present invention, a coating liquid containing a pigment and an adhesive as main components is coated on both sides of the coated base paper in an amount of 6 g / m ² (absolute dryness) or more to form a coated paper for offset printing. A coated base paper having an absolute dry rice basis weight of 40 g / m ² or more, which is used for the above, wherein the coated base paper has 0.3 to 1.5 of cationized starch per absolute dry weight of pulp constituting the base paper. The present invention relates to a base paper for coated paper for offset printing, which is manufactured by using 0.1% by weight of polyacrylamide and 0.1% by weight of polyacrylamide.

When the coated base paper is less than 40 g / m ^{2 of} absolutely dry rice, the frequency of blistering is greatly reduced because of the low water content in the coated base paper. The rate can be suppressed to a low level, and the folding crack strength of double-sided coated paper is not reduced.

The amount of coated double coated paper is 6 g per side.
Even if it is less than / m ² (absolute dryness), steam escapes through the coated surface, and the occurrence of blistering is greatly reduced.

On the other hand, the coated base paper 40 g of dried rice
/ M ² or more, the amount of steam generated in the paper increases,
Blistering is likely to occur. Furthermore, when the coated base paper is 40 g / m ² or more of dry-dry rice, and when the coating amount of double-sided coated paper is 6 g / m ² (absolutely dry) or more per side, blistering occurs greatly. Since it becomes easier, the interlaminar strength of the coated base paper must be increased.

Therefore, according to the present invention, the coated base paper is absolutely dry tsubo 40
g / m ² or more, and coating amount of double-sided coated paper is 6 g / m on one side
It is particularly significant for improving the blister resistance and crease strength of double-sided coated paper that is ² (absolutely dry) or more. A double-sided coated paper consisting of a coated base paper below the above range does not need to apply the present invention because both the blister resistance and the crease resistance are within desired levels without applying the present invention.

[0021] Cationized starch is inexpensive and has a sufficient effect of improving the interlaminar strength, and it is indispensable to enhance the internal paper strength for improving the blister resistance of double-sided coated paper considering economy. It is an agent. The cationized starch of the present invention is a modified starch having a cationic group, and a commercially available type is sufficient, and the type of modification is not limited.

The addition rate of cationized starch (per absolute dry weight of pulp) is 0.3 to 1.5% by weight. If it is less than 0.3% by weight, the interlayer strength does not rise to a desired level.
If cationized starch is added in an amount of more than 1.5% by weight, the coated base paper becomes hard and loses its elasticity, and the double-sided coated paper is deteriorated in fold crack strength and deteriorates in quality.

Although the required level of interlaminar strength increases and the addition rate of cationized starch increases as the absolute dry rice basis weight of the coated base paper increases, the coating consisting of the coated base paper having an absolute dry rice basis weight of 40 g / m ² or more. In order to prevent the strength of the paper from cracking,
It is indispensable to use a paper strength enhancer, which is different from cationic starch and does not impair the elasticity of paper, together with cationic starch in order to improve the crease resistance as well as the blister resistance of coated paper. .

Various internal paper strength enhancers having an effect of improving the interlaminar strength of the coated base paper, for example, anionic, cationic,
Nonionic or amphoteric polyacrylamide polymer,
Organic compounds such as polyethyleneimine and its derivatives, polyethylene oxide, plant gum, polyvinyl alcohol, cationic latex, cationic urea formalin resin, melamine formalin resin, and polyamide resin are all suitable for the present invention, but amphoteric polyacrylamide-based compounds are preferred. Coalescence is most suitable for the present invention.

Further, among the amphoteric polyacrylamide polymers, those having a molecular weight of 2,000,000 to 3,000,000 are suitable for the present invention, especially in combination with cationized starch, because the paper does not become hard. The polyacrylamide polymer has a high effect on the interlaminar strength of the coated base paper, and hardly cures the paper within the range of the addition ratio of the present invention.

The addition rate of the polyacrylamide-based polymer (hereinafter referred to as polyacrylamide) having an amphoteric property and a molecular weight of 2 to 3,000,000 is 0.1 to 1.0% by weight based on the absolute dry weight of the pulp constituting the coated base paper, It is preferably 0.2 to 0.8% by weight.

When the addition rate of polyacrylamide is less than 0.1% by weight, the addition rate of cationized starch used in combination is 1.
The content may exceed 5% by weight, and the breaking strength of the coated paper may decrease, which is not preferable. Even if the addition rate exceeds 1.0% by weight, no further improvement in the interlaminar strength is observed, so that the chemicals are wasted and the economical efficiency in the production of double-sided coated paper is unfavorable.

The raw material pulp constituting the coated base paper contains a fixing agent, a sizing agent, a retention improving agent, a drainage improving agent which are widely used as an internal addition aid in addition to the cationized starch and polyacrylamide. A pH adjusting agent, a pitch control agent, a slime control agent, an antifoaming agent and the like can be appropriately added if necessary.

The papermaking method of the present invention is suitable for both so-called acidic papermaking and neutral papermaking. Whichever papermaking method is used, in order to use the polyacrylamide and the cationized starch, it is most preferable to add them to the pulp slurry comprising pulp, broke and filler.

The coated paper for printing is produced by coating one or both surfaces of the coated base paper of the present invention with a coating liquid containing a pigment and an adhesive as main components. The coating composition generally has a solid content of 40 to 75% by weight, preferably 45 to 70% by weight.
Adjusted to a range of degrees. In forming the coating layer by coating the coating liquid on the coating base paper, the coating layer may be formed by applying the coating liquid once, or the coating layer may be divided into an undercoat layer and an overcoat layer to form a multilayer structure. You may form as. In the case of a multi-layer structure, the undercoat layer and the overcoat layer do not have to have the same coating liquid composition, and the coating liquid composition can be appropriately changed according to the required quality level.

The coating layer may be formed by a conventional coating apparatus such as a blade coater, an Aa knife coater, a roll coater, a reverse roll coater, a bar coater, a curtain coater, a die slot coater, and a gravure coater. The coating liquid is applied to the surface of the coated base paper using various coaters such as a coater, a Chambrex coater, a brush coater, and a size press coater.
These coating devices may be used in either on-machine or off-machine coater form.

The coating amount of the coating liquid on the coated base paper is usually about ² to 50 g / m ^{2 on a} dry basis, but it is 5 when considering the quality of blank paper and printability of the obtained coated paper. ~ 3
It is desirable to adjust in the range of about 0 g / m ² . Also,
The coated paper obtained in this way usually has a water content of 3
After drying so as to be in the range of about 10% by weight, the paper is passed through an on or off super calendar or the like for pressure finishing.

Cellulose pulp constituting the coated base paper of the present invention includes soft-leaf bleached kraft pulp (referred to as NBKP) and hard-leaf bleached kraft pulp (referred to as LBKP), as well as high-yield pulp such as refiner ground pulp (RG).
P), thermomechanical pulp (TMP), stone ground pulp (GP), used newspapers and newspapers, and deinked used paper pulps made from OA used papers (quality used papers).

[0034]

EXAMPLES The present invention will be described in more detail with reference to specific examples. All parts and% in the examples are parts by weight and% by weight. The following description and examples are illustrative of the invention and are not limiting of the invention.

The polyacrylamide used had a molecular weight of 26.
Hermide EX-360 manufactured by Harima Kasei Co., Ltd., which is an amphoteric polyacrylamide having a capacity of 0,000 to 2.8 million, and the cationized starch was Kate F manufactured by Oji National Co., Ltd., both of which were added to the pulp slurry before papermaking. The addition ratios of cationized starch and polyacrylamide are shown in the following Examples and Comparative Examples, and other conditions such as pulp and auxiliaries used are listed below.

Coated base paper 1 NB adjusted to have a freeness of 430 ml (C.S.F.)
40 parts KP and 410 ml freeness (C.S.F.)
Pulp (slurry) consisting of 60 parts of LBKP adjusted to
Light calcium carbonate (10 parts) was added to 100 parts, and cationized starch, polyacrylamide (addition rate was changed in Examples and Comparative Examples), and sulfuric acid band (homemade) 0.5% to 100 parts of pulp. , Yield improver (NR-11LH manufactured by Kyoritsu Organic Co., Ltd.) 0.02% was added,
Paper is made with a long-net multi-cylinder dryer type paper machine and starch is made with a size press (Oji Ace A manufactured by Oji Constarch Co., Ltd.) 1.8
g / m ² and external sizing agent (Polymaron manufactured by Arakawa Chemical Co., Ltd.)
0.02g / m ² was applied and the water content was 5.5%.
A coated base paper of ² g / m ² was produced.

Coated base paper 2 NB adjusted to have a freeness of 430 ml (C.S.F.)
30 parts KP and 390 ml freeness (C.S.F.)
Pulp (slurry) consisting of 70 parts of LBKP adjusted to
4 parts of light calcium carbonate was added to 100 parts, and further cationized starch, polyacrylamide (addition rate was changed in Examples and Comparative Examples), and sulfuric acid band (homemade) 0.5% to 100 parts of pulp. , Yield improver (NR-11LH manufactured by Kyoritsu Organic Co., Ltd.) 0.02% was added,
Paper is made with a long-steel multi-cylinder dryer type paper machine, and starch (made by Oji Konstarch Co., Ltd.) 2.5 g / m ² and external sizing agent (Polymaron made by Arakawa Chemical Co., Ltd.) 0.03 g /
m ² was applied to produce a coated base paper having a water content of 5.5% and an absolutely dry rice weight of 90 g / m ² .

Coating A coating solution having the following composition was coated on the coated base paper in the same amount on both sides with a blade coater, dried with an air foil dryer at 150 ° C., and then supercalendered. The water content of the coated paper was 5.5% by weight. Kaolin 60 parts Heavy calcium carbonate 40 parts Starch 2.5 parts (per 100 parts pigment) Styrene-butadiene latex 11 parts (per 100 parts pigment)

The quality of the coated base paper and the coated paper was evaluated by the following method. (1) Blister resistance A RI printing tester manufactured by Akira Seisakusho kneads 1 ml of offset printing ink and prints on both sides of coated paper. Immediately after 250
The condition of blistering on the printed surface caused by heating from both sides at ° C was visually evaluated. ◎: Extremely good ○: Slightly excellent △: Normal ×: Slightly inferior XX: Extremely inferior

(2) Interlaminar strength (coated base paper) Adhesive tape (Tesa No 4863 width 38 mm manufactured by Beiersdorf (Germany) 38 mm width) is evenly pressed on both sides of the coated base paper to give a width of 2
After cutting into a 5 mm strip shape, the adhesive strength on both sides of the strip was pulled with a Tensilon universal tensile tester (manufactured by Toyo Bold-In Co., Ltd.) to remove the paper layer of the coated base paper. (G) was evaluated.

(3) Folding strength of coated paper: JIS P81
Follow 15. (Sample: Cutting parallel to the papermaking direction of the coated base paper machine) (4) Stiffness of coated base paper: According to JIS P8125. (Sample: Cut parallel to the papermaking direction of the coated base paper machine)

Example 1 In the coated base paper 1, 0.3% of cationized starch and 0.9% of polyacrylamide per weight of bone-dry pulp were used.
Was added. 7 g / m ² per side of this coated base paper (dry)
The above-mentioned coating liquid was applied to produce a double-sided coated paper.

Example 2 In the coated base paper 1, 0.3% of cationized starch and 0.9% of polyacrylamide per weight of bone-dry pulp were used.
% Added. This coated base paper was coated with 15 g / m ² (absolutely dry) of the above-mentioned coating solution on each side to produce a double-sided coated paper.

Example 3 In the coated base paper 1, 1.4% of cationized starch and 0.2% of polyacrylamide were added per weight of the absolutely dried pulp.
% Added. This coated base paper was coated with 7 g / m ² (absolutely dry) of the above-mentioned coating solution on each side to produce a double-sided coated paper.

Example 4 In the coated base paper 1, 1.4% of cationized starch and 0.2% of polyacrylamide per weight of bone-dry pulp were used.
% Added. This coated base paper was coated with 15 g / m ² (absolutely dry) of the above-mentioned coating solution on each side to produce a double-sided coated paper.

Example 5 In the coated base paper 2, 0.6% of cationized starch and 0.9% of polyacrylamide per weight of bone-dry pulp were used.
% Added. This coated base paper was coated with 7 g / m ² (absolutely dry) of the above-mentioned coating solution on each side to produce a double-sided coated paper.

Example 6 In the coated base paper 2, 0.6% of cationized starch and 0.9% of polyacrylamide per weight of bone-dry pulp were used.
% Added. This coated base paper was coated with 15 g / m ² (absolutely dry) of the above-mentioned coating solution on each side to produce a double-sided coated paper.

Example 7 In the coated base paper 2, cationized starch was 1.4% and polyacrylamide was 0.5% based on the weight of absolutely dry pulp.
% Added. This coated base paper was coated with 7 g / m ² (absolutely dry) of the above-mentioned coating solution on each side to produce a double-sided coated paper.

Example 8 In the coated base paper 2, cationized starch was 1.4% and polyacrylamide was 0.5% based on the weight of absolutely dry pulp.
% Added. This coated base paper was coated with 15 g / m ² (absolutely dry) of the above-mentioned coating solution on each side to produce a double-sided coated paper.

COMPARATIVE EXAMPLE 1 In the coated base paper 1, 0.1% of cationized starch and 1.2% of polyacrylamide per weight of bone-dry pulp were used.
A coated paper was produced in the same manner as in Example 1 except that the amount of the added amount was 0.1%.

Comparative Example 2 In the coated base paper 1, 0.1% of cationized starch and 1.2% of polyacrylamide were used per weight of the absolutely dry pulp.
A coated paper was produced in the same manner as in Example 2 except that the amount of the added amount was 0.1%.

Comparative Example 3 A coated paper was prepared in the same manner as in Example 3 except that 1.8% of cationized starch was added to the coated base paper 1 and the polyacrylamide was not added. Manufactured.

Comparative Example 4 A coated paper was prepared in the same manner as in Example 4 except that 1.8% of cationized starch was added to the coated base paper 1 and the polyacrylamide was not added. Manufactured.

Comparative Example 5 In the coated base paper 2, 0.2% of cationized starch and 1.4% of polyacrylamide were used per weight of bone-dry pulp.
A coated base paper was produced in the same manner as in Example 5 except that the addition amount of 10% was added.

Comparative Example 6 In the coated base paper 2, 0.2% of cationized starch and 1.4% of polyacrylamide were used per weight of the absolutely dried pulp.
A coated base paper was produced in the same manner as in Example 6 except that the addition amount of 10% was added.

Comparative Example 7 A coated base paper was produced in the same manner as in Example 7 except that the coated base paper 2 contained 2.4% of cationized starch based on the weight of absolutely dry pulp and no polyacrylamide was added. .

Comparative Example 8 A coated base paper was produced in the same manner as in Example 8 except that the coated base paper 2 contained 2.4% of cationized starch based on the weight of absolutely dry pulp and no polyacrylamide was added. .

Comparative Example 9 NB adjusted to a freeness of 430 ml (C.S.F.)
KP 45 parts and freeness 410 ml (C.S.F.)
Pulp (slurry) consisting of 55 parts of LBKP adjusted to
10 parts of light calcium carbonate was added to 100 parts, and further 1.3% of cationized starch, 0.5% of sulfuric acid band (homemade), yield improver (NR-11LH manufactured by Kyoritsu Organic Co., Ltd.) based on the weight of absolutely dry pulp 0 0.02% was added. Paper making by Fourdrinier paper machine using this paper stock, starch size press (manufactured by Oji Cornstarch Co., Ltd.) 1.5 g / m ² and the external sizing agent coated (manufactured by Arakawa Chemical Industries, Ltd. Polymaron) 0.02 g / m ² Then, a coated base paper having a water content of 5.5% and an absolutely dry tsubo of 38 g / m ² was produced. 5.5 g / m on each side of this coated base paper
² (absolutely dry) coating solution was applied to produce double-sided coated paper.

Comparative Example 10 To the coated base paper 2, 0.6% of cationized starch and 0.9% of cation-modified polyamide resin (Kaymen 1300, manufactured by Dick Hercules Co., Ltd.) were added per 100% by weight of absolutely dry pulp. 15g / m per side of this coated base paper
² (absolutely dry) of the above coating liquid was applied to produce double-sided coated paper.

Table 1 shows the quality evaluation results of the coated base papers prepared in Examples 1 to 8 and Comparative Examples 1 to 10. As can be seen from Table 1, when polyacrylamide is not used,
Since the paper becomes hard (the rigidity increases) and the folding crack strength (folding strength) decreases, the evaluation result of the blister resistance of the coated paper becomes low (see Comparative Examples 3, 4, 7, and 8). On the other hand, the combination of the cationized starch and polyacrylamide in an appropriate range can eliminate the above-mentioned drawbacks (Example 3,
See 4, 7, 8).

On the other hand, polyacrylamide can be used in an amount exceeding the range of the present invention so as to decrease the amount of cationized starch, and the blister resistance can be maintained at the same level. It is also economically disadvantageous (see Comparative Examples 1, 2, 5, and 6). in this case,
By increasing the amount of cationized starch and decreasing the amount of polyacrylamide slightly, it is possible to improve the blister resistance in a state where quality and economy are balanced (Example 1,
2, 5, 6).

On the other hand, when the absolute dry weight of the coated base paper and the coating amount are lower than the ranges of the present invention, the evaluation result of the blister resistance and the crease strength are good even if the polyacrylamide is not used in combination. It is not necessary to apply the invention (see Comparative Example 9). Furthermore, even if a cationized starch and a paper strength enhancer other than polyacrylamide are used in combination, the crease cracking strength is lowered and the blister resistance cannot be made to an excellent level (see Comparative Example 10).

[0063]

EFFECTS OF THE INVENTION As is clear from the above description, the present invention uses both cationic starch and polyacrylamide as an internal paper strength enhancer, and the addition ratios per absolute dry weight of the pulp constituting the coated base paper are different from each other. 0.3-1.5% by weight and 0.1
When the content is in the range of 1.0% by weight, there is an effect that it is possible to provide a coated base paper which improves the crease strength of the coated paper and improves the blister resistance of the coated paper for printing while maintaining the economical efficiency. .

[0064]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 7199-3B D21H 5/00 Z

Claims (1)

[Claims] 1. A coating liquid containing a pigment and an adhesive as main components,
6 g / m ² (absolute dryness) or more per side, absolutely dry rice tsubo 4 used for coating on both sides to make coated paper for offset printing
It is a base paper of 0 g / m ² or more, and the coated base paper has 0.3 to 1.5% by weight of cationized starch and 0.1% by weight of polyacrylamide per absolute dry weight of pulp constituting the base paper.
A base paper for coated paper for offset printing, which is produced by adding 1 to 1.0% by weight.