JPH0657686A - Base paper for coated paper for web offset printing - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a base paper for offset rotary printing coated paper, which is excellent in eliminating wrinkles generated in rotary offset printing. Concerning a base paper for offset rotary printing mainly composed of pulp fiber, the ratio of the maximum value and the minimum value of the microwave transmission intensity obtained by the microwave measurement method of the base paper is 1.70 or less, and further Fenchel's water immersion elongation in the transverse direction of the base paper is 4.0% or less, and the JIS-
A base paper for offset rotary printing coated paper, which has a value obtained by dividing the air permeability defined by P-8117 by the paper thickness defined by JIS-P-8118 at 0.6 seconds / μm or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base paper for offset rotary printing coated paper which is excellent in eliminating wrinkles generated in rotary offset printing.

[0002]

2. Description of the Related Art In recent years, in rotary offset printing, along with the improvement of printing methods and the increasing demand for printed materials, there has been a trend toward higher speed printing and high-quality multicolor printing. Further, with the progress of printing machines, there is a demand for quality characteristics of printing paper, which produces a higher quality printing effect. By the way, since the offset rotary printing is a printing method in which high-temperature drying is continuously performed after printing, phenomena such as blisters and wrinkles that are not seen in other printing methods occur. here,
A wrinkle is a wrinkle that occurs in the flow direction of the paper when the ink on the paper is forcibly dried at a high temperature immediately after offset rotary printing. The cause of such wrinkles is generally due to the difference in shrinkage amount between the image area and the non-image area during high temperature drying in offset rotary printing (Japanese Patent Laid-Open No. 58-18670).
However, there are still many problems to be improved. The wrinkles as described above not only lower the printing effect but also impair the appearance of the printed matter.

[0003]

DISCLOSURE OF THE INVENTION The present invention, in rotary offset printing on coated paper, identifies the physical properties of the coated base paper to provide excellent offset rotary printing with an excellent effect of eliminating the wrinkles generated in the drying step. The present invention provides a base paper for coated paper.

[0004]

According to the present invention, in a base paper for offset rotary printing mainly composed of pulp fibers, the ratio of the maximum value and the minimum value of the microwave transmission intensity obtained by the microwave measurement method is 1.70 or less, further, the water penetration elongation of Fenchel in the transverse direction of the base paper is 4.0% or less, and the air permeability of the base paper specified in JIS-P-8117 is divided by the paper thickness specified in JIS-P-8118. Value is
It is a base paper for coated paper for offset rotary printing characterized by being 0.6 second / μm or less.

[0005]

In the offset rotary printing, the present inventors have
We have earnestly conducted research on the above-mentioned factors causing the wrinkles and measures to solve them. As a result, it was found that the wrinkle phenomenon occurring in the drying process of offset rotary printing is greatly related to the fiber orientation of the base paper, the water immersion elongation and the air permeability, and by adjusting these conditions, the wrinkle The generation is extremely efficiently suppressed, and in offset rotary printing,
The inventors have found that the coated paper can have an excellent printing effect and have completed the present invention.

Here, the fiber orientation of the base paper is a tendency that pulp fibers are lined up in the outflow (longitudinal) direction in the process of flowing out on the wire of the paper machine, dehydrating and forming a paper layer.
That is, at the time of papermaking, the stock material flows out on the wire at a high speed and is dehydrated, so that the number of fibers oriented in the longitudinal direction (the flow direction of the raw material on the paper machine) increases, and the tensile strength and rigidity in the longitudinal direction are increased in the transverse direction. It is considerably stronger or higher than (width direction). Probably, such a difference in the length and width (nonuniformity) of the base paper causes stress strain of the pulp fibers and contributes to the wrinkles.

Further, when the obtained base paper has a high water immersion elongation, that is, a high elongation due to water, the amount of shrinkage when the coated paper is dehydrated in the drying process of the offset rotary printing becomes large, resulting in wrinkles. It tends to occur. Also,
When the air permeability of the base paper is poor, it indicates that there are few voids in the base paper, and even if the fiber orientation and the water immersion elongation are improved, the strain due to shrinkage is difficult to be absorbed in the strong drying process of the offset rotary printing, and as a result, The wrinkle phenomenon is promoted.

From the above, it is possible to drastically reduce or eliminate the wrinkle phenomenon by adjusting the above three factors, that is, the fiber orientation, the water immersion elongation and the air permeability of the base paper to the specific values desired in the present invention. I found it.

The fiber orientation, water immersion elongation and air permeability of the base paper will be described below. Generally, as a method for measuring the fiber orientation of the base paper, for example, a thermal expansion method, a mechanical breaking strength method, an X-ray diffraction method, an ultrasonic method, a microwave measuring method,
The NMR method, the polarized fluorescence method, the dielectric measurement method and the like can be mentioned.
In the present invention, a microwave type molecular orientation meter (manufactured by Kanzaki Paper Co., Ltd.) is employed, and the microwave transmission intensity is measured to obtain the fiber orientation of the paper. This device (JP-A-59-1)
JP-A-88546) can measure the fiber orientation of paper in a non-contact, non-destructive, rapid, simple and accurate manner.

This microwave type molecular orientation meter was developed based on the idea of evaluating the orientation of molecules from the anisotropy of the dielectric constant in the microwave region.
Utilizing the fact that the dielectric constant based on the orientation polarization of local molecular motions such as micro Brownian motions of polymer chains and twisting of the main chain is observed at room temperature in the microwave region, which is the frequency range of 00MHz to 30GHz. There is.

That is, the sample (sheet) surface set in the cavity resonator system is irradiated with the microwave polarized wave vertically while the sample is rotated to change the angle between the reference direction of the sample and the microwave polarized wave. The angle dependence of the wave transmission intensity is obtained, and the ratio between the maximum and minimum values of the microwave transmission intensity (index of anisotropy) and the orientation angle (deviation between the molecular chain axis and the reference direction) can be known. be able to. In this case, the above ratio of 1 means that the orientation of the fibers is lost. Therefore, the paper qualities in the longitudinal direction and the lateral direction of such paper, for example, the paper qualities such as tension, rigidity, or water immersion elongation have the same value. However, in the case of the paper actually made by the Fourdrinier paper machine, even if the adjustment to make it 1 is made, it is slightly oriented in the longitudinal direction (paper making direction).

In the offset rotary printing coated base paper of the present invention, the ratio of the maximum value of the microwave transmission intensity to the minimum value thereof is 1.70 or less, more preferably 1.50.
It will be as follows. Incidentally, when this ratio exceeds 1.70, the fiber orientation becomes strong, the stress strain of the pulp fiber becomes extremely large, and the generation of wrinkles is promoted.

Here, as a method for controlling the orientation of pulp fibers, the kind and the number of parts of pulp fibers, the machine speed, the outflow speed (= J) of the pulp slurry onto the wire and the wire speed (= W). (Hereinafter, referred to as J / W ratio), an arrangement of forming boards or hydrofoils, and suitability of wire shake or dandy roll, and the like, and these conditions can be appropriately combined. On the other hand, it is necessary to harmonize the texture of the paper and the quality of other papers.

Next, the water immersion elongation means "J. TAPPI paper pulp test method" No. According to the method described in No. 27-78, the value after the immersion time of 2 minutes in the lateral direction of the base paper is measured. For Fourdrinier paper machine,
Normally, the tension in the longitudinal direction is constant because the tension is dried, but the tension in the lateral direction is relaxed each time the dryer is released, so that the paper is shortened in the lateral direction. Therefore, due to the change in water content in the paper, the paper hardly changes in expansion and contraction in the vertical direction, but greatly expands and contracts in the horizontal direction. That is, since the measured value in the vertical direction hardly changes, the value in the horizontal direction was adopted.

Further, in this measuring method, the immersion time is set to 5 minutes, but in this case, it is difficult to obtain a difference in measured values, and a satisfactory result cannot always be obtained. Therefore, as a result of various studies, it was found that the value obtained when immersed in water for 2 minutes has a strong correlation with the occurrence of wrinkles.
That is, as a base paper for offset rotary printing coated paper, the Fenchel's water immersion elongation (dipping for 2 minutes) in the lateral direction of the base paper is 4.0% or less, preferably 3.0% or less. Incidentally, when it exceeds 4.0%, the shrinkage amount when the coated paper is dehydrated in the drying step of the offset printing becomes large, and the wrinkles are more likely to occur.

As a method for adjusting the water immersion elongation of the base paper, a method of eliminating uneven distribution of fibers (texture unevenness) or a papermaking chemical such as a plasticizer or a filler is added to adjust the interfiber bond. Method, type of pulp fiber, method of optimizing mixing number and beating condition, etc., method of adjusting J / W ratio, paper flow direction tension (draw) in paper machine, felt mounting pressure, and drying condition, etc. And can be adjusted using at least one of these. Of course,
It is also possible to appropriately combine two or more conditions in consideration of other paper quality.

Regarding the regulation of air permeability, JIS-
It is a value obtained by dividing the air permeability specified in P-8117 by the paper thickness specified in JIS-P-8118. By taking the paper thickness into consideration, the air passage time (second) per unit distance (thickness) (μm) ), Which is an index showing the degree of voids in the base paper. Here, as the base paper for coated paper for rotary offset printing, the air permeability determined in JIS-P-8117 is specified in JIS-P.
The value divided by the paper thickness specified in -8118 is specified to be 0.6 second / μm or less. By the way, this value is 0.6 seconds /
When it exceeds μm, the porosity in the base paper is small, and when the coated paper shrinks during the offset rotary printing drying process, the distortion due to the shrinkage is less likely to be absorbed by the coated paper, resulting in wrinkles. become.

In order to obtain the above values, the beating conditions of pulp, the shape of the filler to be used, the particle size and the amount to be used, and the type and amount of the size press agent to be adjusted, or the size press device to be used, etc. The desired result can be obtained by appropriately selecting or adjusting the calendering conditions for smoothing the base paper.

That is, in the present invention, as described above, the ratio of the maximum value and the minimum value of the microwave transmission intensity of the base paper is 1.70.
Hereinafter, the water immersion elongation of Fenchel in the lateral direction of the base paper is set to 4.0% or less, and the JIS-P of the base paper is set.
A value obtained by dividing the air permeability defined by −8117 by the paper thickness defined by JIS-P-8118 is set to 0.6 seconds / μm or less,
It has been found that the occurrence of wrinkles can be suppressed extremely efficiently by satisfying the conditions 1 to 3 at the same time.

As the base paper in the present invention, one having a basis weight of about 30 to 400 g / m ² can be appropriately used. At the time of papermaking of the base paper, a filler, a sizing agent, a paper strength enhancer, a yield improving agent, various auxiliaries and the like can be appropriately added.

The pulp is appropriately selected and used from chemical pulp and mechanical pulp made from wood fibers and plant fibers such as hemp, recycled pulp obtained from chemical pulp and mechanical pulp, synthetic pulp, inorganic fibers and the like. .

As the filler, known and publicly-used materials generally used in the paper manufacturing industry are appropriately used. Furthermore, pigments contained in waste paper, broaches, etc. can be recycled as fillers. In addition to pulp fibers and fillers in the paper, various anionic, nonionic, cationic or amphoteric retention aids that have been conventionally used in the range not impairing the desired effects of the present invention, An internal additive for papermaking, such as a water-based improver, a paper strength improver, and an internal sizing agent, is used as necessary.

Further, dyes, optical brighteners, pH adjusters,
An internal additive for papermaking such as a defoaming agent, a pitch control agent, and a slime control agent is appropriately added as necessary.

The papermaking method is, for example, papermaking PH 4
It is about 5 to about 5 or a so-called neutral paper, which is weakly acidic with a pH PH of about 6 and weakly alkaline with a papermaking PH of about 9, which is mainly composed of an alkaline filler such as calcium carbonate. Further, as the paper machine, a Fourdrinier paper machine, a twin wire machine, a cylinder paper machine, a Yankee paper machine or the like is appropriately used.

The coating composition thus obtained, which is applied to the base paper, comprises a pigment, an adhesive and various auxiliaries used in the general field of producing coated paper. As the pigment, at least one selected from clay, kaolin, aluminum hydroxide, calcium carbonate, titanium dioxide, barium sulfate, zinc oxide, calcium sulfate, talc, satin white, calcined kaolin, various white carbons, organic pigments, etc. is appropriately selected. used.

Examples of the adhesive include proteins such as casein, soybean protein and synthetic protein; conjugated diene polymer latex such as styrene-butadiene copolymer, polymers or copolymers of acrylic acid ester and / or methacrylic acid ester. Acrylic polymer latex such as coalesce, vinyl polymer latex such as ethylene-vinyl acetate copolymer; or alkali solubility of these various polymer latex modified with functional group-containing monomer such as carboxyl group Alternatively, alkali-insoluble polymer latex; synthetic resin adhesives such as polyvinyl alcohol and melamine resin; positive starch,
At least one of ordinary adhesives for coated paper such as starches such as oxidized starch; cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose is appropriately selected and used. In addition, the adhesive is generally 5 to 50 with respect to the pigment.
%, Preferably 10 to 30% by weight.

Further, various auxiliary agents such as a water-proofing agent, an antifoaming agent, a release agent, and a flow modifier are appropriately added to the coating composition, if necessary, to solidify the coating layer. As an accelerating agent,
For example, 0.1 to 10% by weight of amine, amide, polyacrylamine, etc. or salt of polyvalent metal such as zinc, aluminum, magnesium, calcium, barium, etc. with respect to the pigment.
It can be added to some extent.

The coating composition obtained under the above conditions is
Installed coating equipment such as blade coater, air knife coater, roll coater, reverse roll coater, bar coater, curtain coater, die slot coater, gravure coater, champlex coater, size press coater, etc. used in general coated paper manufacturing On-machine or off-machine coater is used to coat the base paper in one layer or two or more layers.

At this time, the solid content concentration of the coating composition is generally about 40 to 75% by weight, but it is preferably in the range of 45 to 70% by weight in consideration of workability and the like. The coating amount when the coating composition is coated on the base paper is 3 to 25 g / m ² per side.
Adjusted in a range of degrees.

As a method for drying the wet coating layer, various methods such as steam heating, hot air heating, gas heater heating, electric heater heating, infrared heater heating, high frequency heating, laser heating and electron beam heating are adopted. However, it is not particularly limited. This coated paper is on-machine,
Alternatively, off-machine calendering can be performed, and conventional devices such as a machine calender, a super calender, a soft compact calender, and a gross calender can be appropriately used.

[0031]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the scope of the invention is not limited thereto. In the examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively, unless otherwise specified.

Example 1 [Preparation of base paper] 90 parts of LBKP (csf 360 ml),
To a pulp slurry consisting of 10 parts of NBKP (csf 360 ml), a heavy calcium carbonate (trade name; Softon 1200 / manufactured by Bihoku Powder Co., Ltd.) was added as a filler so that the paper ash content was 5%, and further aluminum sulfate 0. 3 parts, cationic starch (BMB-190 / manufactured by Nissan Eka Nobel) 0.5 part, alkyl ketene dimer (brand name: Hacon 601 / Dick Hercules) 0.04 parts as an internally added sizing agent, 0.1 part of colloidal silica (trade name; BMA-0 / manufactured by Nissan Eka Nobel) was added to prepare a paper stock, which was then paper-made with a Fourdrinier paper machine to obtain a raw paper. The J / W ratio was 0.980. Oxidized starch (brand name; Ace A)
/ Oji Corn Starch Co., Ltd.) 5% and surface sizing agent (trade name; Polymaron 1308 / Arakawa Chemical Industry Co., Ltd.) 0.0
A 5% aqueous solution was size-pressed on both sides to 50 cc / m ^2, and after drying, a base paper having a specific value as shown in Table 1 and having a specific weight of 70 g / m ² was obtained. The papermaking conditions (arrangement of forming board or hydrofoil, suitability of wire shake or dandy roll, tension in the flow direction of the paper machine (draw), press, calender linear pressure, etc.) were appropriately adjusted.

[Preparation of coating composition] 30 parts of heavy calcium carbonate (trade name; Softon 1800 / Bihoku Kouka Co., Ltd.),
0.3 part of sodium polyacrylate was added as a dispersant to an aqueous dispersion of a pigment consisting of 70 parts of kaolin (trade name; manufactured by HT / EMC Co., Ltd.) and dispersed using a Corres disperser to give a solid content concentration of 68 % Pigment slurry was prepared. Oxidized starch (trade name; Ace A / Oji Cornstarch Co., Ltd.) 5 parts (solid content), styrene-butadiene copolymer latex (trade name; JSR0696 / Nippon Synthetic Rubber Co., Ltd.) (solid content) 10 parts Was added, and water was added to obtain a coating composition having a solid content concentration of 60%.

[0034] In a blade coater so previously prepared basis weight of [coated paper were obtained in the above coated composition is 10 g / m ² on one surface per dry weight base paper of 70 g / m ² to be double-sided coating Performed and dried to obtain a coated paper. The method for measuring the paper quality of the base paper and the evaluation criteria were as follows.

[Measurement of Fiber Orientation of Base Paper] A microwave type molecular orientation meter (manufactured by Kanzaki Paper Co., Ltd.) was used to measure the microwave transmission intensity, and the ratio between the maximum value and the minimum value was obtained.

[Measurement of Submersion Elongation of Base Paper] “J. TAPP
I Pulp Test Method "No. According to the method described in 27-78, the value after 2 minutes of immersion in water was measured.

[Measurement of Air Permeability of Base Paper] JIS-P-81
According to 17.

[Measurement of Paper Thickness of Base Paper] JIS-P-811
According to 8.

[Formation of Wrinkles] The formation of wrinkles was visually evaluated according to the following criteria. Evaluation Criteria ⊚: Almost no generation of wrinkles. ○: Occurrence of wrinkles is occasionally seen, but there is no problem in practical use. B: Occurrence of wrinkles is clearly observed. X: Generation of wrinkles is remarkable.

Example 2 In the preparation of the base paper of Example 1, the Canadian standard freeness of the pulp slurry was changed to NBKP and LB.
A coated paper was obtained in the same manner as in Example 1 except that the KP was 550 ml, the J / W ratio was 0.995, and 0.14 parts of the internally added sizing agent was added. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Example 3 In preparing the base paper of Example 1, the Canadian standard freeness of the pulp slurry was changed to NBKP, LB.
A coated paper was obtained in the same manner as in Example 1 except that the KP was 400 ml, the J / W ratio was 1.020, and 0.08 part of the internally added sizing agent was added. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Example 4 In the preparation of the base paper of Example 1, LBKP (csf32
(0 ml) 90 parts, NBKP (csf 320 ml) 10 parts, to a pulp slurry containing talc as a filler so that the paper ash content is 10%, and as an internal sizing agent, a rosin sizing agent (trade name: Size Pine E) (Manufactured by Arakawa Chemical Industry Co., Ltd.) and 0.7 part of aluminum sulfate and 2 parts of aluminum sulfate were added to prepare a paper stock, which was then made with a twin wire paper machine to obtain a raw paper. The J / W ratio was 0.980. An aqueous solution containing 5% of oxidized starch (trade name; Ace A / manufactured by Oji Corn Starch) and 0.05% of surface sizing agent (trade name; Polymarlon 1308 / manufactured by Arakawa Chemical Industry Co., Ltd.) with a size press machine. 50cc / m on both sides
^A size press treatment was performed so that the weight became ^2, and after drying, a base paper having a specific value shown in Table 1 and a basis weight of 70 g / m ² was obtained. In addition, papermaking conditions (arrangement of forming board or hydrofoil, tension in paper machine flow direction (draw) and press, calender linear pressure, etc.)
A coated paper was obtained in the same manner as in Example 1 except that was changed appropriately. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.
It was shown to.

Example 5 In preparing the base paper of Example 4, the Canadian standard freeness of the pulp slurry was changed to NBKP, LB.
A coated paper was obtained in the same manner as in Example 1 except that the KP was 560 ml, the J / W ratio was 1.005, and the base paper was obtained under the same base paper adjustment conditions as in Example 4. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Example 6 In the preparation of the base paper of Example 4, the Canadian standard freeness of the pulp slurry was changed to NBKP and LB.
A coated paper was obtained in the same manner as in Example 1 except that the KP was 600 ml, the J / W ratio was 1.015, and 1.4 parts of the internally added sizing agent was added. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Example 7 In preparing the base paper of Example 4, the Canadian standard freeness of the pulp slurry was changed to NBKP, LB.
A coated paper was obtained in the same manner as in Example 1 except that the KP was 560 ml, the J / W ratio was 1.020, and the internally added sizing agent was 0.6 part. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Comparative Example 1 In the preparation of the base paper of Example 1, the Canadian standard freeness of the pulp slurry was changed to NBKP, LB.
A coated paper was obtained in the same manner as in Example 1 except that the KP was 450 ml, the J / W ratio was 1.030, and the internally added sizing agent was 0.05 part. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Comparative Example 2 In the preparation of the base paper of Example 1, the Canadian standard freeness of the pulp slurry was changed to NBKP, LB.
Coated paper was obtained in the same manner as in Example 1 except that the KP was 380 ml, the J / W ratio was 0.975, and the internally added sizing agent was 0.03 part. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Comparative Example 3 In the preparation of the base paper of Example 1, the Canadian standard freeness of the pulp slurry was changed to NBKP and LB.
Coated paper was obtained in the same manner as in Example 1 except that KP was 270 ml, the J / W ratio was 0.995, and 0.10 part of the internally added sizing agent was added. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Comparative Example 4 In the preparation of the base paper of Example 4, the Canadian standard freeness of the pulp slurry was changed to NBKP, LB.
A coated paper was obtained in the same manner as in Example 1 except that the KP was 590 ml, the J / W ratio was 1.005, and the internally added sizing agent was 0.5 part. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Comparative Example 5 In the preparation of the base paper of Example 4, the Canadian standard freeness of the pulp slurry was changed to NBKP and LB.
A coated paper was obtained in the same manner as in Example 1 except that the KP was 300 ml, the J / W ratio was 1.025, and the internally added sizing agent was 0.9 part. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Comparative Example 6 In the preparation of the base paper of Example 4, the Canadian standard freeness of the pulp slurry was changed to NBKP and LB.
A coated paper was obtained in the same manner as in Example 1 except that the KP was 280 ml, the J / W ratio was 0.970, and 0.4 parts of the internally added sizing agent was added. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Comparative Example 7 In the preparation of the base paper of Example 4, the Canadian standard freeness of the pulp slurry was changed to NBKP and LB.
A coated paper was obtained in the same manner as in Example 1 except that the KP was 300 ml, the J / W ratio was 1.010, and the internally added sizing agent was 0.4 part. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

[0053]

[Table 1]

[0054]

As is apparent from Table 1, the coated paper obtained by using the base paper for offset rotary printing coated paper obtained by the method of the present invention has less wrinkles in offset rotary printing. It was of excellent quality.

Claims (3)

[Claims] 1. In a base paper for offset rotary printing mainly comprising pulp fibers, the ratio of the maximum value and the minimum value of the microwave transmission intensity obtained by the microwave measurement method of the base paper is 1.70 or less, Further, the water penetration elongation of Fenchel in the transverse direction of the base paper is 4.0% or less, and the JI of the base paper is
The air permeability specified in SP-8117 is JIS-P-811.
A base paper for offset rotary printing coated paper, characterized in that the value divided by the paper thickness specified in 8 is 0.6 sec / μm or less. 2. The base paper for offset rotary printing coated paper according to claim 1, wherein the ratio of the maximum value and the minimum value of the microwave transmission intensity obtained by the microwave measurement method of the base paper is 1.50 or less. 3. The base paper for coated web for offset rotary printing according to claim 1, wherein the water penetration elongation of Fenchel in the transverse direction of the base paper is 3.0% or less.