JP2012107365A - Rolled newsprint paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolled newsprint paper having a good operability in low cost such that when transporting a bare rolled paper that is not packed, an upper paper of the rolled paper does not break and the problem hardly occurs by giving a criterion for a good operability.SOLUTION: There is provided a rolled newsprint paper having a basis weight of 40 g/m-48 g/min which a value of a tensile strength (longitudinal)/a coefficient of static friction is limited in a range of 5.0 kN/m or more and 7.2 kN/m or less. It is preferable that the rolled newsprint paper has an internal bond strength (longitudinal) of 100 mJ or more and 170 mJ or less, and it is further preferable that the outer peripheral surface of the rolled paper is coated with a slipping agent.

Description

The present invention relates to a newspaper web used in winding. More specifically, a newspaper web that can be provided at low cost with excellent operability at the time of manufacture, printing, etc., because it is difficult for tearing of the upper web of the web to be caused by collision between the webs during conveyance of the web. About.

To date, when paper such as high-quality paper, bleached kraft paper, unbleached kraft paper, and various coated papers manufactured on a paper machine is shipped as a product, it is manufactured on a paper machine, coating machine, or processing machine. A large paper roll of paper is cut into a desired width by a winder to form a flat paper, which is then wrapped with a moisture-proof packaging sheet material to form a box-shaped package. In addition, these paper products, especially newspaper webs, are made into rolls with relatively small rolls, and in order to prevent moisture absorption, breakage, dirt, etc. of the paper, moisture-proof packaging sheet materials, liner paper, kraft paper, etc. Packaged with packaging sheet material and shipped. These packaged products are generally transported by freight car, truck or ship. However, such a packaged flat paper or roll is wound into a roll. One or one piece has a weight of 500-1500 kg and is very heavy, and is stacked while being stored in the paper warehouse, when being carried in or out of the paper warehouse, or during the conveyance. A considerably strong force is applied to the outside of the product package by contact between the objects or between the windings.

In recent years, automation in printing factories has advanced significantly in all aspects. For example, in a newspaper printing factory, there are some areas where everything from loading newspaper rolls into a paper warehouse to unpacking wrapping paper and feeding to a rotary press is automated. In each automated process, a sensor determines whether the process is normal or abnormal, and if it is abnormal, the process is generally stopped and checked for safety.
In many cases, the paper taken into the paper warehouse is unpacked in advance and the wrapping paper is removed and the paper is left as it is, that is, it is handled in the form of the paper itself. There is an increasing demand for increasing the number of windings for the purpose of reducing the number of paper feeds, and as a result, the diameter of the winding becomes significantly larger (increase in diameter) and the weight of the winding also increases accordingly. In recent newspaper rolls, there are 70 papers that weigh about 1.4 tons.

On the floor of a paper warehouse for such a newspaper printing factory, there is a case where the winding is usually inclined by 1 to 2 degrees from the carry-in side to the carry-out side (generally called a slanted paper warehouse). ing). The loaded take-up is sequentially transferred by a conveyor and moved to a row with less take-up, and is pushed out from the upper side of the inclined surface by the moving pusher, that is, from the carry-in side to the carry-out side, and taken up. Rolls on an inclined surface and stops by colliding with a stopper provided in the middle of the inclined surface. Subsequently, the windings that are pushed out one after another collide with the previously stopped winding and are stopped. In this way, 4 to 5 windings are always left in contact with each other at a place where there is one stopper. Thereafter, these windings are sequentially sent to a stopper provided in front of the carry-out conveyor below the inclined surface, and are placed on the carry-out conveyor and sent to the rotary press depending on the carry-out state of the take-up. The same state as described above is repeated at the place where the stopper is installed. The number of rows in the winding flow direction is determined according to the scale of the printing factory.

In such a slanted paper warehouse, the winding stopper collides with the winding, and the friction between the windings causes a pulling force in the vertical direction of the paper, and several sheets on the surface side of the winding are torn. It may lead to peeling (this is described as tearing of the upper paper). This is because generally used newspaper webs are significantly reduced in weight with a basis weight of 40 to 48 g / m ² in order to reduce the burden of newspaper delivery and transportation. It is weaker than that of other printing papers, and for the reasons described above, the weight increases as the number of windings increases, so the impact force is further promoted. Higher.
When such a trouble occurs, the operation of the process must be temporarily stopped, and the operator must remove the broken piece of paper. The meaning of labor saving by automation is lost. In addition, if such troubles occur at a newspaper company's printing plant for newspaper printing, where immediacy is critically important, newspapers will be delayed.

The following techniques have been proposed for such problems.
(1) In the winder, the friction coefficient increasing agent is sprayed and applied to one side in the range of 7 to 25 m from the end of winding of the product winding, and the dynamic friction coefficient between the coated papers is different from that of the winding upper paper. The coefficient of dynamic friction with the upper paper of the winding is made larger. (Patent Document 1)
(2) A friction coefficient increasing agent is applied or sprayed on the inner surface of the paper constituting the winding so that the dynamic friction coefficient μ2 between the papers constituting the winding is 0.45 or more and 0.70 or less. The difference (μ2−μ1) between the outer surfaces and the dynamic friction coefficient μ1 is set to 0.14 or more. (Patent Document 2)
(3) JAPAN TAPPI Paper Pulp Test Method No. 37. A web for newspaper printing based on 37, having a web hardness (R) of 40 to 60 and a dynamic friction coefficient of 0.45 to 0.65. (Patent Document 3)
(4) Newspaper printing paper specified by applying a modified starch, an alkyl ketene dimer, and an anti-slip agent to a base paper that has not been internally added and having a dynamic friction coefficient in the range of 0.40 to 0.70. . (Patent Document 4)

Japanese Patent Laid-Open No. 5-24724 JP-A-5-25795 JP 2005-133262 A Japanese Patent Laid-Open No. 7-279094

In Patent Document 1, the friction coefficient increasing agent spraying process in the winder is increased, and a portion where the friction coefficient increasing agent is sprayed and a portion where the friction coefficient increasing agent is not sprayed are formed in one winding. There is a problem that the print finish is not good. When printing, about 4 or 5 sheets are removed from the outer periphery. However, since the upper limit of the length to which the friction coefficient increasing agent is sprayed is as long as 25 m, there is a high possibility that a sprayed portion remains. At this time, the problem that a difference in printability occurs cannot be solved.
In Patent Document 2, a friction coefficient increasing agent is applied or sprayed on one side of paper. At present, the surface treatment agent is often applied to newsprint base paper with a gate roll coater. However, since this coater shares a tank and supply line, a surface treatment agent containing a friction coefficient increasing agent is applied only to one side. In order to do so, improvements are required.
Moreover, when spraying, there exists a problem similar to patent document 1. FIG. That is, the friction coefficient increasing agent spraying process is increased, and a portion where the friction coefficient increasing agent is sprayed and a portion where the friction coefficient increasing agent is not sprayed are formed in one winding, so that there is a difference in printability, and a uniform print finish is not obtained. is there.
In Patent Document 3, a sufficient effect cannot be obtained only by the specified conditions, and adding a friction coefficient adjusting agent or the like to the entire paper leads to a significant cost increase.
In Patent Document 4, it is necessary to use an expensive anti-slip agent for the coating layer, and the process is complicated.

Although the above technology can prevent the tearing of the upper cover to some extent, it causes an increase in manufacturing costs, an increase in processes, and problems with printability, so it is not satisfactory as a countermeasure, and more effective. There is a need for the development of technologies that can be appropriately prevented.

When transporting unwrapped bare take-ups, the upper paper is not torn in the take-up, and the operability at the time of manufacture, printing, etc. shows good standards, so the problem is unlikely to occur. Further, it is an object of the present invention to provide inexpensive newspaper webs that have good operability during manufacturing and printing.

The present invention, in the newspaper web typical basis weight ^{40g / m 2 ~48g / m 2} , the value of the tensile strength (vertical) / static friction coefficient by a specific range, thereby resolving the problem described above I got the knowledge that I can do it. The configuration of the present invention is as follows.
(1) basis weight to a newspaper web of ^{40g / m 2 ~48g / m 2} , the value of the tensile strength (vertical) / static friction coefficient of 5.0 kN / m or more and less 7.2KN / m Newspaper rolls featuring
(2) The newspaper web as described in (1), wherein the internal bond strength (vertical) is 100 mJ or more and 170 mJ or less.
(3) The newspaper web as described in (1) or (2), wherein a lubricant is applied only to the outer circumferential surface of the winder.

 According to the present invention, it is possible to obtain a newspaper web that is less likely to tear.

The newspaper web of the present invention has a tensile strength (longitudinal) / static friction coefficient ratio of 5.0 kN / m or more and 7.2 kN / m or less, which is the ratio of tensile strength (longitudinal) and static friction coefficient. The tensile strength (longitudinal) and the coefficient of static friction of newspaper web are adjusted.
The coefficient of friction is related to the tensile force acting on the upper paper constituting the winding when the windings during conveyance collide with each other. Since the coefficient of static friction is the maximum value of the coefficient of friction, it is related to the maximum value of the tensile force that acts on the upper paper and tries to break it. On the other hand, the tensile strength (longitudinal) represents the force that can be endured per unit length in the width direction when the upper paper receives a tensile force.
If the coefficient of static friction is large, the tensile force for breaking the upper paper increases, so that the upper paper can be prevented from being broken by correspondingly increasing the tensile strength (vertical). If the coefficient of static friction is small, the tensile force to break the upper paper is also small, so if there is a corresponding tensile strength, the upper paper can be prevented from tearing, so the tensile strength ( Vertical) is not required. The ratio of tensile strength (longitudinal) and coefficient of static friction indicates the ratio of the force that the upper paper can withstand tearing and the action of trying to break the upper paper, and this ratio is in a specific range to prevent the upper paper from being torn. It is necessary.
This researcher finds that the range of the ratio needs to be 5.0 kN / m or more and 7.2 kN / m or less in order to solve the problem of tearing the upper sheet, and completes the present invention. It came to.
When the value of tensile strength (longitudinal) / static friction coefficient is less than 5.0 kN / m, the upper paper that is the denominator has a large effect of breaking the upper paper against the force that the upper paper of the molecule can withstand. The possibility of occurrence increases. A tensile strength (longitudinal) / static coefficient of friction exceeding 7.2 kN / m means that (1) the numerator is excessively large or (2) the denominator is excessively small. In order to increase the blending ratio and increase the tensile strength (longitudinal), excessive addition of a paper strength enhancer and beating of pulp are performed more than necessary. When the chemical pulp content is increased, the scattering coefficient decreases and the opacity of the paper becomes lower. Therefore, the paper strength enhancer is excessively added without increasing the chemical pulp content, or the pulp is beaten. In this case, since the paper becomes inflexible, there is a problem that it becomes weak against stress concentration and easily breaks when subjected to tearing force. Moreover, excessive addition of a paper strength enhancer may cause deterioration of formation and cost increase. On the other hand, in the case of (2), there is a high possibility that problems such as paper flow at the time of printing, unevenness in the stacker, and load collapse will occur.
The static friction coefficient is a value obtained by bringing the longitudinal directions and the surfaces (surfaces that are outside of the winding) into contact with each other.

As a method for adjusting the tensile strength (longitudinal) of the newspaper web of the present invention, there are a method of adjusting on the raw material side, such as adding a beating degree of pulp, a cationic starch or a paper strength enhancer described later. In addition, by changing the jet / wire ratio (J / W ratio: the speed of the paper jet, which is the speed at which the paper is jetted onto the wire) during paper making, the fibers are oriented in the longitudinal direction, thereby There is also a mechanical adjustment method that increases the tensile strength in the direction.
In the case of a gap former type paper machine widely used in the manufacture of newspaper webs, it is said that the jet / wire ratio is adjusted in the range of 0.97 to 1.05. It is desirable that the aspect ratio of the tensile strength, which is a quotient obtained by dividing the tensile strength (longitudinal) by the tensile strength (horizontal), is adjusted in the range of 2.6 to 3.6. If it is less than 2.6, the operation of increasing the tensile strength performed on the raw material side is not easily reflected, and high-speed papermaking exceeding 1000 m / min becomes difficult. When it is larger than 3.6, the tendency of the fibers to be oriented in the longitudinal direction becomes strong. In this case, the property of the fiber having a large stretch ratio in the transverse direction relative to the longitudinal direction (approximately 10 to 30 times or more) appears in the paper made of each fiber, and the elongation in the transverse direction (CD direction, Cross Direction) is remarkable. Become. Then, when moisture is absorbed, the paper stretches in the horizontal direction, but because it is restrained by the form of winding, moisture absorption wrinkles are likely to occur.
In addition, it is desirable that the tensile strength (vertical) is 3.4 kN / m or less in view of an increase in used paper mixing ratio and operability recently required by users.

The coefficient of static friction of the newspaper web of the present invention is preferably 0.44 or more and 0.61 or less. If it is less than 0.44, problems such as wrinkling and misregistration due to paper flow at the time of printing may occur, and if it is more than 0.61, problems such as clogging of the sword and wrinkling will occur at the time of printing.
Since the static friction coefficient is strongly affected by the roughness of the surface, the static friction coefficient can be lowered by increasing the calendar pressure. (If the smoothness of newspaper rolls is within the range, increasing the smoothness will reduce the friction coefficient.) However, pressure is applied to the paper, resulting in higher density and changing the paper thickness, which is an important specification for newspaper rolls. The adjustable range is narrow. An anti-slip agent can be used to increase the static friction coefficient, and a lubricant can be used to decrease the coefficient of static friction.

Since newspaper webs are printed by an offset printing method using dampening water, it is necessary to impart size. Some surface sizing agents change the static friction coefficient, so that the static friction coefficient can be adjusted using the surface sizing agent.
To increase the coefficient of friction, a styrene / acrylic surface sizing agent can be used. The sizing agent is a rubber-based substance and has a certain anti-slip effect.
In order to lower the static friction coefficient, an alkyl ketene dimer-based surface sizing agent can be used.
The static friction coefficient also varies depending on the blending of pulp, pulp freeness, addition of filler, change of pigment coating, and the like.

The newspaper web of the present invention will be described in more detail.
The newspaper web of the present invention contains DIP obtained by deinking waste newspaper, magazine waste paper, etc., or mechanical pulp or other pulp, but from the viewpoint of resource reuse, it is preferable that DIP is highly blended. . As the mechanical pulp, thermomechanical pulp (TMP), ground wood pulp (GP), refiner ground wood pulp (RGP), pressured ground wood pulp (PGW), or the like can be used. These mechanical pulps contribute to improving the opacity of newspaper webs. As other pulps, chemical pulps such as softwood kraft pulp (NKP) and hardwood kraft pulp (LKP) can be appropriately blended. Chemical pulp contributes to improving the tensile strength of newspaper webs.

(Filler)
In the newspaper web of the present invention, a filler can be added for the purpose of improving opacity after mixing pulp as a raw material in the preparation step. Examples of the filler used include white carbon, calcined kaolin, calcium carbonate, talc, and kaolin. Among them, the static friction coefficient increases when white carbon or calcined kaolin is used, and the static friction coefficient decreases when talc or kaolin is used.

(Auxiliary)
If necessary, internal sizing agents such as saponified rosin sizing agent, rosin emulsion sizing agent, alkyl ketene dimer, alkenyl succinic anhydride can be used, but alkyl ketene dimer has the effect of reducing the coefficient of static friction. Therefore, it is necessary to use the final product with care so that the value of the tensile strength (longitudinal) / static friction coefficient of the final product falls within the range of 5.0 kN / m or more and 7.2 kN / m or less.
If necessary, fixing agents such as sulfuric acid band, cationic starch, and cationic polyacrylamide resin can be internally added. In addition, paper strength enhancer for dry paper strength, wet strength paper strength enhancer, slime control Additives such as agents, pitch control agents, antifoaming agents and dyes can also be used.
The papermaking pH may be any of acidic, neutral and alkaline. A pulp suspension obtained by mixing these raw materials is made by a known paper machine.

The newspaper web of the present invention is coated with a surface treatment agent containing an adhesive on the base paper. The purpose of this surface treatment agent application is to impart sizing to the paper in addition to imparting surface strength or printability to the paper. In order to impart these functions, starch-based adhesives such as oxidized starch and phosphate esterified starch and water-soluble polymer substances such as carboxymethyl cellulose and polyvinyl alcohol are used. It is processed and gelatinized. As the surface treatment agent, other known chemicals such as an anti-slip agent, a lubricant, a thickener, an antifoaming agent and a dye can be used. In addition, a pigment may be used for the surface treatment agent for the purpose of improving whiteness and opacity, or improving ink deposition.

A surface sizing agent may be used as the surface treatment agent applied to the base paper of the newspaper web of the present invention.
As the surface sizing agent, an alkyl ketene dimer surface sizing agent and a polymer surface sizing agent may be used in combination. Two types of surface sizing agents are used for the following reason.
When an alkyl ketene dimer surface sizing agent is used for newspaper webs, a high sizing effect can be obtained, but if the amount added is increased, slippage during printing, wrinkling due to paper flow, paper breakage, etc. may occur. Becomes higher.
However, if a polymer surface sizing agent is used together with an alkyl ketene dimer surface sizing agent, the coating amount of the alkyl ketene dimer surface sizing agent can be suppressed, and the anti-slip effect of the polymer surface sizing agent can be reduced. As a result, the above problem can be prevented from occurring. That is, it is possible to prevent slipping during printing, wrinkling due to paper flow, paper breakage, and the like while obtaining a high size effect.
The degree of sizing required for newspaper webs can be adjusted by the surface sizing agent and the internal sizing agent. Compared to alkyl ketene dimer surface sizing agents, other surface sizes have a lower sizing effect, but if the surface sizing agent alone is insufficient in sizing, it can be compensated by the addition of an internal sizing agent or wet paper strength enhancer. it can.

Examples of the coater for applying the surface treatment agent include a gate roll size press, a two roll size press, a rod metering size press, a blade metering size press, a blade coater, a rod coater, and a bar coater. A gate roll size press suitable for the amount of coating is preferred.
The paper coated with the surface treatment agent is subjected to a calendar process through a drying process. As the calendar device used here, a machine calendar in which both surfaces are treated with a metal roll, a soft calendar composed of an elastic roll and a metal roll, a shoe calendar, and the like are used.

The newspaper web, which has been calendered and taken up by a reel, is taken up to a predetermined size (width and length) by a winder and sent to a packaging machine in the next process for packaging. Here, it is desirable to apply the lubricant only to the winding outer peripheral surface after the winder finish.
The newspaper web of the present invention is characterized in that the value of tensile strength (longitudinal) / static friction coefficient is in the range of 5.0 kN / m or more and 7.2 kN / m or less. By applying and lowering the friction coefficient of only the upper paper portion, it is possible to further suppress the possibility of occurrence of upper paper tearing in the inclined paper storage. Even if a lubricant is applied, the outermost surface of the winding is removed at the time of printing, so that the paper quality of the entire newspaper web is not affected.
As a lubricant, it is desirable to use powdered talc in terms of effectiveness, availability and cost. There is a method of applying to the surface when rolling and winding.

The internal bond strength (vertical) of the newspaper web of the present invention is preferably 100 mJ or more and 170 mJ or less. If the internal bond strength (longitudinal) is too low, delamination will occur on the paper, and there is a possibility that the paper will break due to the concentration of the tensile force in the vertical direction of the paper. If it is too high, it is added in an excessive range where the effect of the paper strength enhancer is gradually reduced, or the pulp is beaten more than necessary, so the tear strength is greatly reduced and the power used in the preparation process is reduced. Problems such as enlargement occur. In order to increase the internal bond strength (vertical), internal addition of cationic starch is effective, but in addition to this, DIP with a high blending ratio to which a paper strength enhancer is added is beaten, and the freeness is 10 to 30 ml. There are methods such as lowering the degree.

In newspaper webs, in order to prevent tearing of the upper paper, there can be considered a corresponding means for reducing the frictional force acting between the upper papers on the winding surface by reducing the static friction coefficient. Another countermeasure is that the upper paper has a sufficient tensile strength to withstand the tensile force caused by the frictional force.
However, when the coefficient of static friction is small, troubles such as wrinkles and misregistration due to paper flow at the time of printing may occur. In order to increase the tensile strength, the use of high-strength pulp and pulp beating can be considered. However, newspaper rolls mainly use deinked waste paper pulp (DIP). It is difficult to select and use, and also for beating, the freeness of DIP is lower than that of virgin pulp, so the adjustable range is narrow. In addition, the increase in strength due to the addition of a paper strength enhancer is not only limited by the deterioration of the formation, but also increases the cost.
There are many restrictions on countermeasures against tearing of upper paper, and newspaper webs are manufactured under different manufacturing conditions in accordance with the requirements of each printing factory. Since the degree of freedom in manufacturing conditions increases, operations can be facilitated while clearing problems, and newspaper webs can be provided at low cost.

The present invention will be specifically described below with reference to examples. Of course, the present invention is not limited thereto. In addition, the mass%, the mass part, and the coating amount are represented by solid content or active ingredients unless otherwise specified.

Example 1
Cationic starch (product name: CATO304, Japan) with respect to 100 parts by mass of pulp raw material in which DIP (Canada standard freeness 219 ml) is mixed with 80% and TMP (Canadian standard freeness 110 ml) as a pulp raw material in a proportion of 20%. NS Co., Ltd.) 1%, yield improver (product name: ND260, Hymo Co., Ltd.) 0.020 parts by mass, white carbon (Maruzumi Engineering Co., Ltd.) 1.5% ash in paper, Add light calcium carbonate (product name: Tama Pearl TP-121S, manufactured by Okutama Kogyo Co., Ltd.) to contain 4.5% ash in the paper, and adjust the pH to 5.8 with a sulfuric acid band (manufactured by Marusumi Engineering Co., Ltd.). Then, paper was made using a gap former type paper machine at a J / W ratio of 0.99. Next, using a gate roll size press, a surface treatment agent containing an adhesive and a surface sizing agent was applied as follows.
(Conditions for surface treatment agent coating, calendar, etc.)
Oxidized starch (product name: MS9000, manufactured by Nippon Shokuhin Kako Co., Ltd.) is used as an adhesive, and a polymer surface sizing agent (olefin-based surface sizing agent, product name: Polymaron OM-25, manufactured by Arakawa Chemical Industries, Ltd.) It was used.
With the same coating amount on both sides of the base paper so that the coating amount per side of the adhesive is 0.50 g / m ² and the coating amount per side of the polymer surface sizing agent is 0.028 g / m ^2. Coated.
After coating, the film was dried and treated at a calender pressure of 42 kN / m and a temperature of 81 ° C. to obtain newsprint paper having a basis weight of 44.0 g / m ² with a reel. From the reel winding, a series of 70 A-roll newspaper rolls were obtained in a winder. The paper making speed on the reel was 1,220 m / min.

(Example 2)
The same operation as in Example 1 was conducted except that 0.3% of a paper strength enhancer (polyacrylamide-based dry paper strength enhancer, product name: Polystron 1280, manufactured by Arakawa Chemical Industries, Ltd.) was added instead of cationic starch. I went and got a newspaper roll.

(Example 3)
DIP was beaten to a Canadian standard freeness of 190 ml, and the same operation as in Example 1 was carried out except that the addition of cationic starch was 0, and a newspaper web was obtained.

Example 4
Except that the addition of cationic starch was 0 and the J / W ratio was adjusted to 0.98, the same operation as in Example 1 was performed to obtain a newspaper web.

(Example 5)
The addition of cationic starch is 0, and the surface sizing agent of the surface treatment agent is used at a ratio of 1: 1 of an olefin type surface sizing agent and an AKD type surface sizing agent (product name: SE2395, manufactured by Seiko PMC Co., Ltd.) Except that the J / W ratio was adjusted to 1.00, the same operation as in Example 1 was performed to obtain a newspaper web.

(Example 6)
Except that the addition of cationic starch was 0 and the basis weight was 47.2 g / m ² , the same operation as in Example 1 was performed to obtain a newspaper web.

(Example 7)
DIP was beaten to a Canadian standard freeness of 190 ml, and the same operation as in Example 4 was performed except that the basis weight was changed to 40.3 g / m ² to obtain a newspaper web.

(Example 8)
A newspaper web was obtained in the same manner as in Example 1 except that NBKP (Canadian standard freeness 504 ml) was used in place of TMP, and the addition of cationic starch was set to 0.

Example 9
Except for replacing all TMP with DIP to make DIP 100%, the same operation as in Example 3 was performed to obtain a newspaper web.

(Example 10)
The addition of cationic starch was set to 0, and the surface sizing agent of the surface treatment agent was used in a ratio of 1: 1 of an olefin type surface sizing agent and an AKD type surface sizing agent (product name: SE2395, manufactured by Seiko PMC Co., Ltd.). Performed the same operation as in Example 1 to obtain a newspaper web.

(Example 11)
A paper roll was obtained by performing the same operation as in Example 1 except that 0.3% of the paper strength enhancer was added and that all the AKD surface sizing agent was used as the surface sizing agent.

(Example 12)
The same operation as in Example 4 was performed except that 0.5% of cationic starch was added and a styrene / acrylic surface sizing agent (product name: SS2754, manufactured by Seiko PMC Co., Ltd.) was used as the surface size. Obtained.

(Example 13)
A newspaper web was obtained in the same manner as in Example 4 except that the DIP was 50% (Canadian standard freeness of 205 ml) and the TMP was 50%, and the AKD surface sizing agent was used for the entire surface size.

(Example 14)
Except that the addition of cationic starch was 0, the calendar pressure was 55 kN / m, and the temperature was 90 ° C., the same operation as in Example 1 was performed to obtain a newspaper web.

(Example 15)
The same operation as in Example 14 except that DIP was beaten to a Canadian freeness of 190 ml, and the surface sizing agent was used in a ratio of 1: 1 of olefin surface sizing agent and AKD surface sizing agent. And obtained a newspaper roll.

(Comparative Example 1)
Except that the addition of cationic starch was set to 0, the same operation as in Example 1 was performed to obtain a newspaper web.

(Comparative Example 2)
Except that the J / W ratio was adjusted to 1.01, the same operation as in Comparative Example 1 was performed to obtain a newspaper web.

(Comparative Example 3)
Except for using a styrene / acrylic surface sizing agent as the surface sizing agent, the same operation as in Example 2 was performed to obtain a newspaper web.

(Comparative Example 4)
The same operation as in Example 3 was performed except that white carbon was ash content 3.5% and light calcium carbonate (product name: Tama Pearl TP-121S, manufactured by Okutama Kogyo Co., Ltd.) was ash content 1.0%. I got a newspaper roll.

(Comparative Example 5)
Comparative Example 1 except that the basis weight was 40.5 g / m ² and the polymer surface sizing agent of the surface treatment agent was used in a ratio of 1: 1 of olefin surface sizing agent and AKD surface sizing agent. The same operation was performed and a newspaper roll was obtained.

(Comparative Example 6)
Except for DIP 50% (Canadian standard freeness 219 ml) and TMP 50%, the same operation as in Comparative Example 5 was performed to obtain a newspaper web.

(Comparative Example 7)
A newspaper web was obtained by performing the same operation as in Comparative Example 1 except that the basis weight was 47.8 g / m ² and a styrene / acrylic surface sizing agent was used as the surface sizing agent.

(Comparative Example 8)
Except for setting the coating amount of the surface sizing agent to 0.035 g / m ² , the same operation as in Example 11 was performed to obtain a newspaper web.

(Comparative Example 9)
The same operation as in Comparative Example 8 was performed except that 0.5% of the paper strength enhancer was added and the coating amount of the surface sizing agent was 0.028 g / m ² to obtain a newspaper web.

(Comparative Example 10)
Except that the J / Y ratio was adjusted to 0.97, the same operation as in Comparative Example 1 was performed to obtain a newspaper web.

The measurement method and evaluation method of each test were as follows.
[Measurement method of tensile strength (longitudinal) (horizontal) and tensile strength aspect ratio]
From the outside of the take-up, collect the upper paper that is the outermost layer when three layers are removed in addition to all the layers that are damaged due to tearing of the upper paper. This upper paper was equally divided in a width direction of 500 mm, and test pieces in the longitudinal direction and the transverse direction for tensile strength measurement were collected from sheets collected from each part. The test piece was measured based on JISP8113: 2006, and the measured values were averaged to obtain measured values of tensile strength (longitudinal) (lateral) and tensile strength aspect ratio.
[Static friction coefficient]
In accordance with the tensile strength measurement method, two test pieces for measuring the static friction coefficient in the vertical direction were collected. About this test piece, it measured based on JISP8147: 1994 "friction coefficient test method of paper and paperboard", and the measured value of the static friction coefficient was obtained by averaging a measured value. The measurement was performed between test pieces obtained from sheets having the same width direction, and the combination of measurement was the vertical direction for the vertical and horizontal directions of the paper, and the surface (the surface to be the outer side of the winding) for the measurement surface.
[Measurement method of internal bond strength (vertical)]
A test piece for measuring the internal bond strength in the longitudinal direction was collected according to the method for measuring the tensile strength. JAPAN TAPPI No. 18-2 “Paper and paperboard—Internal bond strength test method—Part 2: Internal bond tester method”, values were measured under a pressing pressure of 4.0 kgf / cm ² and a pressing time of 10 seconds. By averaging the measured values obtained, a measured value of internal bond strength (longitudinal) was obtained.
[Frequency of tears on newspaper rolls]
The obtained newspaper webs (20 for each example and each comparative example) were placed on an inclined surface with an inclination of 2 degrees with two windings spaced at an interval of 8 m, and the winding below the inclined surface was stopped by a stopper. The number of occurrences of tearing of the upper paper was taken as the frequency, with the windings above the slopes rolling and colliding with each other.

(Measurement result)
The newspaper webs produced in Examples 1 to 15 and Comparative Examples 1 to 10 were measured for the tensile strength length, tensile strength aspect ratio, static friction coefficient, internal bond strength, and number of tears of the upper paper. The results are shown in Table 1.

In the newspaper webs shown in Examples 1 to 15, when the value of tensile strength (longitudinal) / static friction coefficient is in the range of 5.0 kN / m or more and 7.2 kN / m or less, upper paper tearing does not occur. I understand that.

Comparative Examples 1 to 7 and 10 are cases where the value of tensile strength (longitudinal) / static friction coefficient is smaller than 5.0 kN / m. In Comparative Examples 1 to 7, tearing of the upper paper occurred. In Comparative Example 10, although the upper paper was not broken, there was a problem that moisture absorption wrinkles were generated on the paper on the winding surface layer.

Comparative Examples 8 and 9 are cases where the value of tensile strength (longitudinal) / static friction coefficient is greater than 7.2 kN / m. The paper flow occurred. Further, in Comparative Example 9, a formation defect occurred and a defect (measured by a paper inspection machine installed in the paper machine, the defect means a black spot having a size of 2 mm or more) occurred due to contamination in the system.

As shown above, when the value of tensile strength (longitudinal) / static friction coefficient is in the range of 5.0 kN / m or more and 7.2 N / m or less, it is possible to prevent paper breakage on winding. It can be seen that the operability is also good.

The present invention is effective when applied to newspaper webs delivered to a printing shop having an inclined paper storage. Although the present invention describes winding with the wrapping paper removed and stripped naked, even with winding wound in a wrap, peeling may occur in the dam at the time of collision. Because of the similar phenomenon, the idea seems to be applicable for Wamp paper quality.

Claims (3)

Basis weight a newspaper web of ^{40g / m 2 ~48g / m 2} , tensile strength (vertical) / static value of the friction coefficient of 5.0 kN / m or more, and equal to or less than 7.2KN / m Newspaper roll. The newspaper web according to claim 1, wherein the internal bond strength (vertical) is 100 mJ or more and 170 mJ or less. The newspaper web according to claim 1 or 2, wherein a lubricant is applied only to the outer circumferential surface of the winding.