TW201738165A - Paper capable of stable paper feeding - Google Patents

Abstract

The present invention relates to a paper the raw material of which is wood pulp, wherein the paper has a mean deviation (MMD) of the friction coefficient on the surface thereof according to the KES method of 0.022 or less, and a formation index on the surface thereof of 90 or more. The paper according to the present invention is made of wood pulp and is capable of stable paper feeding.

Description

Paper that can stably feed paper

The present invention relates to a paper which uses wood pulp as a raw material and which can stably perform a paper feeding operation.

In general, various papers using wood pulp as a raw material such as printing paper, engineering paper, and spacer paper are distributed in the form of a laminate in which a plurality of sheets of paper are laminated, and when used, the paper is taken out one by one from the laminated body.

In the industrial use, the operation of taking out the paper from the laminated body is usually mechanized or automated for the efficiency of the work. For example, the holding means such as a gripper or a suction means such as a vacuum pad is used to hold the uppermost paper of the laminated body. At the end, the paper is supplied one by one to the next step by moving the holding means (Patent Document 1 and Patent Document 2).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1]: JP-A-2008-230853

[Patent Document 2]: JP-A-2013-124169

However, in the case where the paper of the highest position of the laminated body of the paper is held by the holding means and the holding means is moved, there is a case where a sheet of paper is moved and moved in contact with the uppermost paper, so that The position of the next sheet of paper changes from the initial position.

As described above, when the position of the paper to be fed is changed, the holding means cannot maintain the fixed position of the paper, and it is difficult to stably perform the paper feeding. In particular, if the fluctuation of the position of the paper becomes large, it is difficult to perform the automatic take-out operation by the machine at a high speed.

Therefore, it is considered to reduce the contact area between the uppermost paper and the next paper when the uppermost paper of the laminated body is moved, thereby suppressing the movement of the next paper.

However, it has been confirmed that even if the holding means is moved not only along the horizontal direction of the paper surface of the next paper but also in a direction away from the paper surface, in order to reduce the contact area between the uppermost paper and the next paper, it is impossible to suppress A piece of paper moves.

SUMMARY OF THE INVENTION An object of the present invention is to provide a paper which uses wood pulp as a raw material and which can stably perform a paper feeding operation.

In particular, it is an object of the present invention to provide a paper which maintains the end portion of the uppermost paper of the laminated body of paper which is made of wood pulp as a raw material and causes the paper to move in a direction away from the paper surface. It is possible to suppress the positional change of a sheet of paper in contact with the uppermost paper.

The inventors of the present invention conducted intensive studies and found that the average deviation (MMD) of the friction coefficient of the surface of the paper using wood pulp as a raw material and the texture index were set to a specific range. The present invention can be accomplished by solving the above problems.

The first aspect of the present invention is a paper obtained by using wood pulp as a raw material, and the average deviation (MMD) of the friction coefficient of the surface measured by the KES method is 0.022 or less, and the texture index of the surface is 90 or more.

The above MMD is preferably 0.018 or less.

The above texture index is preferably from 100 to 210.

The basis weight of the paper of the present invention is preferably from 20 to 80 g/m ² .

The paper of the present invention is preferably a spacer paper.

The spacer paper is preferably a spacer paper for a metal plate.

The spacer paper is preferably a spacer paper for printing plates.

The spacer paper is preferably a spacer paper for glass sheets.

The above glass plate is preferably used for a display.

The above display is preferably a TFT liquid crystal display or an organic EL display.

A second aspect of the present invention is a laminate comprising at least one sheet of the first aspect of the invention and at least one metal plate, a printing plate or a glass plate.

In the above laminated body, it is preferable that the metal plate, the printing plate or the glass plate is present in plurality, and the paper is present between the plurality of metal plates, the printing plate or the glass plate.

A third aspect of the invention is a method of protecting a metal plate, a printing plate or a glass plate, comprising the step of inserting the paper of the first aspect of the invention between a plurality of metal plates, a printing plate or a glass plate.

A fourth aspect of the present invention is a supply method using wood pulp as a raw material. A paper supply method comprising the steps of holding an end portion of the paper of the laminated layer by a holding means, and moving the holding means in a direction away from a surface of the paper or an extended surface thereof; The average deviation (MMD) of the friction coefficient measured by the KES method on the surface was set to 0.022 or less, and the texture index was set to 90 or more.

According to the present invention, it is possible to provide a paper which uses wood pulp as a raw material and which can stably perform a paper feeding operation.

In particular, it is possible to suppress contact with the uppermost paper by holding the end portion of the uppermost paper of the laminated body of the paper of the present invention by the holding means and moving the paper in a paper feed direction away from the paper surface. The position of a piece of paper changes. Therefore, according to the present invention, the holding means can hold the fixed position of the paper, so that the paper feeding can be stably performed. In particular, according to the present invention, the automatic paper take-out operation can be stably performed by the mechanical high-speed lamination from the paper.

The present invention relates to a paper using wood pulp as a raw material, wherein the average deviation (MMD) of the friction coefficient of the surface measured by the KES method is 0.022 or less, and the texture index of the surface is 90 or more.

The wood pulp which can be used in the present invention is a single use of conifer bleached kraft pulp (NBKP), broadleaf bleached kraft pulp (LBKP), conifer bleached sulfite pulp (NBSP), broadleaf bleached sulfite pulp (LBSP), thermomechanical. Wood pulp (TMP) and other wood pulp or a mixture of them. Preferred are conifer bleached kraft pulp (NBKP) and conifer bleached sulfite pulp (NBSP). The wood pulp can be used as a main body, and the non-wood pulp, the cationized wood pulp, the mercerized wood pulp, etc., such as hemp, bamboo, alfalfa, kenaf, mulberry, fragrant or kapok, can be used separately or in combination as needed. Synthetic or chemical fibers such as pulp, enamel, vinylon, nylon, acrylic, polyester, or microfibrillated wood pulp. However, if the resin component is contained in a large amount in the wood pulp, the resin component may be contaminated by the surface of the object in contact with the paper of the present invention. Therefore, it is preferred to use chemical wood pulp having as little resin component as possible. For example, conifer bleached kraft pulp. Further, high-yield wood pulp such as ground wood pulp is unsatisfactory because it contains a large amount of resin components. In addition, when the synthetic fiber or the chemical fiber is mixed, the machinability is improved, and the workability at the time of making the paper into a lithographic plate is improved, but the recyclability in the waste disposal is deteriorated, so care is required.

Moreover, it is possible to add an adhesive, a mold inhibitor, various paper-making fillers, a wet paper strength enhancer, and a dry paper force to the papermaking fiber mainly composed of the above-mentioned wood pulp, as needed within the range which does not impair the performance of the present invention. Reinforcing agent, sizing agent, coloring agent, fixing agent, antistatic agent, yield improving agent, viscosity control agent, and the like. Also, when adding these drugs, it is necessary to pay close attention not to mix insects or dirt.

When the wood pulp for paper of the present invention is produced, if the pulping of the wood pulp is carried out, the effect of enhancing the strength between the paper layers can be expected. However, if the fine fibers in the wood pulp are increased due to beating, there is a tendency to generate paper dust during use, and therefore, beating is performed more than necessary. The situation is not good. Therefore, in the present invention, the preferred degree of beating is 300 to 650 mlc.s.f.

It is possible to obtain a conventional method such as papermaking of the above-mentioned wood pulp by using a known long-web type paper machine, a rotary net type paper machine, a short-web type paper machine, a combination paper machine of a long net and a rotary net, or the like. Paper of the invention.

The paper of the present invention may also be composed of a plurality of layers, but is preferably a single layer.

The thickness of the paper of the present invention is preferably from 0.01 to 2 mm, more preferably from 0.05 to 1 mm, still more preferably from 0.1 to 0.5 mm.

The basis weight of the paper of the present invention is preferably from 20 to 80 g/m ² , more preferably from 25 to 70 g/m ² , still more preferably from 30 to 60 g/m ² .

The density of the paper of the present invention is preferably from 0.40 to 1.10 g/cm ³ , more preferably from 0.5 to 1.00 g/cm ³ , still more preferably from 0.60 to 0.90 g/cm ³ .

In the first aspect of the invention, the paper has a mean deviation (MMD) of the coefficient of friction of the surface measured by the KES method of 0.022 or less, and a texture index of the surface of 90 or more.

The MMD system uses a friction sensor (KES-SE manufactured by Kato Tech Co., Ltd.) to make a 10 mm square friction element composed of a bundle of 0.5 mm diameter piano wires of 50 g/cm ^{2 on} one side. The average deviation value of the friction coefficient measured by moving the surface of the paper which was fixed at a tension of 20 g/cm under contact with the tension in the same direction as the direction in which the tension was applied was moved by 2 cm at a moving speed of the sample of 0.1 cm/sec.

If the MMD is large, it means that the friction coefficient of the paper surface varies greatly depending on the position of the paper surface. Microscopically, it means that the surface of the paper has a large number of irregularities. If the MMD exceeds 0.022, the slight irregularities on the surfaces of the papers increase, so that the resistance of the papers increases, so good.

The MMD is preferably 0.020 or less, more preferably 0.019 or less, still more preferably 0.018 or less, still more preferably 0.017 or less.

The MMD is, for example, preferably 0.001 to 0.022, more preferably 0.002 to 0.020, still more preferably 0.004 to 0.019.

The "Formation Index" is the standard for the uniformity of the fiber structure of paper. The method of determining the texture index is described in the specification of U.S. Patent No. 6,440,267, and the specification of U.S. Patent No. 6,440,267 is incorporated herein by reference. Specifically, the texture index can be measured by a sheet uniformity tester (for example, a uniformity tester FMT-MIII, manufactured by Nomura Corporation).

If the texture index is small, it means that the fibers in the paper are evenly distributed, and the fibers are too much or too small, so the macroscopically means that the surface of the paper is more uniform in shape. However, a more uniform surface shape of the paper surface means that the paper surface is closer to the plane, and the contact area of the papers with each other increases. If the texture index is less than 90, the contact area of the paper surface will increase, and the offset caused by the friction between the papers will increase, which is not preferable.

The texture index is preferably 95 or more, more preferably 98 or more, and still more preferably 100 or more.

The texture index is, for example, preferably from 95 to 300, more preferably from 98 to 250, and still more preferably from 100 to 210. A method of setting the texture index to a specific range can be carried out by a known method, for example, adjusting the papermaking speed, adjusting the slurry concentration of the wood pulp, adjusting the pulp speed ratio (J/W ratio) of the wire portion in the papermaking step, and adjusting Wire vibrating device, adjusting the tension or suction condition of the wire, or adjusting the conditions of the small printing roller. The J/W ratio is related to the slurry flow associated with the slurry slurry from the slurry box. (slice jet) The ratio of the speed to the speed of the wire.

In the first aspect of the present invention, the average deviation (MMD) of the friction coefficient of the surface measured by the KES method is set to 0.022 or less to reduce minute irregularities on the paper surface, and on the other hand, the texture index of the surface is set. If it is 90 or more, the surface shape of the paper surface is intentionally made uneven, whereby the area where the papers are in contact with each other is reduced, the deviation due to friction is reduced, and the jamming due to minute irregularities on the contact surface is reduced.

The method of producing the paper of the first aspect of the present invention is not particularly limited, and the paper of the first aspect of the present invention can be produced by appropriately selecting the type of wood pulp to be used as a raw material of paper, but in order to be versatile The wood pulp is used as a raw material to produce the paper of the first aspect of the present invention, and is preferably subjected to calendering treatment, super calendering treatment, soft nip calender treatment, embossing, etc. during and/or after the production of the paper of the present invention. machining. By such processing, the surface properties of the paper of the present invention can be adjusted, and the MMD and texture index of the paper surface can be adjusted.

The use of the paper of the first aspect of the present invention is not limited, and may be any type of printing paper or non-printing paper. Examples of the non-printing paper include engineering paper and spacer paper. Regardless of the use, the paper of the first aspect of the invention is preferably a paper of the type that feeds the end portion. Most of this type of paper is a relatively large type of paper having a relatively large weight, and most of them are discontinuous paper in a suitably cut state rather than a continuous paper of a drum shape.

The paper of the first aspect of the invention is preferably a spacer paper. The spacer paper is used, for example, to protect a metal plate, a printing plate (a photosensitive image forming layer is present on the substrate), and a surface of the glass plate. Therefore, the paper according to the first aspect of the present invention is preferably a spacer paper for a metal plate, a spacer paper for printing plates, or a spacer paper for a glass plate.

Thus, the second aspect of the present invention is a laminated body comprising at least one of the present inventions The first aspect of the paper, and at least one metal plate, printing plate or glass plate.

In the laminate of the present invention, preferably, the metal plate, the printing plate or the glass plate is present in plurality, and the paper according to the first aspect of the present invention is present on the plurality of metal plates, the printing plate or the glass plate. between.

Further, a third aspect of the invention is a method for protecting a metal plate, a printing plate or a glass plate, which comprises the step of inserting the paper of the first aspect of the invention between a plurality of metal plates, a printing plate or a glass plate. .

In the case where the paper according to the first aspect of the present invention is a spacer paper for glass sheets, the spacer paper for glass sheets of the present invention is inserted between glass sheets and used. For example, the spacer paper sheets for glass sheets of the present invention are typically inserted one by one between a plurality of glass sheets, and a laminate is formed as a whole, and the laminated body is stored and transported. In this manner, the glass sheet can be inserted between the plurality of glass sheets by the spacer paper to protect the glass sheet. Further, the glass plate alone or the laminated body may be packaged using a spacer for the glass plate.

The glass plate is not particularly limited, and is preferably a glass plate for a flat panel display such as a plasma display panel, a liquid crystal display panel (particularly a TFT liquid crystal display panel), or an organic EL display panel.

In particular, with the increase in the size of the display, the size and weight of the glass plate for a flat panel display are increasing. However, the spacer paper for glass sheets composed of the paper of the first aspect of the present invention can well protect such a large or large size. The surface of the glass plate of weight.

A fourth aspect of the present invention is a supply method of a paper using wood pulp as a raw material, characterized in that it comprises a step of holding an end portion of the paper of the laminated layer by a holding means; The step of moving the holding means away from the surface of the paper or the extending surface thereof, the average deviation (MMD) of the friction coefficient measured by the KES method on the surface of the paper is set to 0.022 or less, and the texture index is set. It is 90 or more.

The MMD is preferably 0.020 or less, more preferably 0.018 or less, still more preferably 0.017 or less.

The MMD is, for example, preferably 0.001 to 0.020, more preferably 0.002 to 0.018, still more preferably 0.004 to 0.017.

The texture index is preferably 95 or more, more preferably 98 or more, and still more preferably 100 or more.

The texture index is, for example, preferably from 95 to 300, more preferably from 98 to 250, and still more preferably from 100 to 210.

In the fourth aspect of the invention, the type of holding means for holding the end portions of the laminated paper is not limited. For example, any holding means used in the paper supply field, such as a jig, a gripping means such as a pair of rolls, and an adsorption means such as a vacuum pad, can be used.

The paper holding the end portion by the holding means is preferably the uppermost paper of the laminated paper.

The above end portion is also not particularly limited. Any portion of the peripheral portion of the paper can be used as the end portion. Specifically, it is preferably in the range of 1 to 50 cm from the periphery of the paper, preferably in the range of 3 to 40 cm, preferably in the range of 5 to 30 cm.

The moving direction of the holding means is not particularly limited as long as it is away from the surface of the paper or the extending surface thereof. For example, if the above holding means is away from the paper The movement vector of the surface or its extension surface may also include a movement vector in the direction of the surface of the paper or its extended surface. Specifically, the holding means may be moved from the paper surface in the vertical direction, or the holding means may be moved from the paper surface in the obliquely upward direction.

In the fourth aspect of the invention, even if the paper of the layer is moved by the holding means, the positional change of one sheet of paper under contact with the paper can be suppressed. Therefore, in the fourth aspect of the present invention, the holding means can hold the fixed position of the paper, so that the paper feeding can be stably performed.

[Examples]

Hereinafter, the present invention will be specifically described using examples and comparative examples, but the scope of the present invention is not limited to the examples.

[MMD]

A frictional testing machine (KES-SE manufactured by Gado Technology Co., Ltd.) will be used to make a 10 mm square friction element composed of a bundle of 0.5 mm diameter piano wires contact with a contact pressure of 50 g/cm ² at 20 g. The surface of the paper fixed by tension of /cm was moved to 2 cm in the same direction as the direction in which the tension was applied, and the average deviation value of the friction coefficient measured was 2 mm.

[Texture Index]

The texture index was measured using a uniformity tester FMT-MIII (manufactured by Nomura Corporation).

[paper feed test]

The paper was cut into the size of a half of the chrysanthemum (636 mm X 470 mm) and 7,000 sheets were laminated. A commercially available printing machine of the type that supplies the paper to the end of the paper, and continuously prints 7,000 sheets at a speed of 7000 sheets per hour at 25 ° C and a relative humidity of 30%. Make the following judgment.

◎: Paper is not offset, and paper feeding can be performed stably.

○: During the paper feeding process, when the paper to be fed is the highest paper, the next paper is moved and the position is moved. However, the printing machine is not stopped and the paper feeding operation is continued.

X: In the paper feeding process, it is observed that when the paper is fed to the uppermost sheet, the next sheet is driven and the position is moved, and the printing machine is stopped.

[Example 1]

The conifer bleached kraft pulp and the broadleaf bleached kraft pulp are mixed at a mass ratio of 90:10 to prepare a wood pulp, which is mashed and the degree of beating is adjusted to a slurry of 520 mlc.sf, and added to all the wood. A cationized starch (trade name: paper strength agent DD4280, manufactured by Starlight PMC Co., Ltd.) having a pulp mass of 0.1 part by mass was used as a paper strength enhancer to prepare a wood pulp slurry having a concentration of 0.2% by mass. Under the condition of a J/W ratio of 0.97, papermaking was carried out by a long-wire type paper machine, and further, smoothing was performed by a soft nip rolling under non-heating conditions at a line pressure of 60 kgf/cm or less. And a paper having a basis weight of 55 g/m ² was obtained. The paper obtained had an MMD of 0.022 and a texture index of 93.

[Embodiment 2]

A paper having a basis weight of 55 g/m ² was obtained in the same manner as in Example 1 except that papermaking was carried out under the conditions of a J/W ratio of 0.95. The paper obtained had an MMD of 0.021 and a texture index of 102.

[Example 3]

A paper having a basis weight of 55 g/m ² was obtained in the same manner as in Example 1 except that the smoothing treatment was carried out by a soft nip rolling under a non-heating condition at a linear pressure of 80 kgf/cm. The paper obtained had an MMD of 0.018 and a texture index of 93.

[Comparative Example 1]

A paper having a basis weight of 55 g/m ² was obtained in the same manner as in Example 1 except that the J/W ratio was set to 1.00. The paper obtained had an MMD of 0.021 and a texture index of 88.

[Comparative Example 2]

A paper having a basis weight of 55 g/m ² was obtained in the same manner as in Example 1 except that the calendering treatment was not carried out. The paper obtained had an MMD of 0.025 and a texture index of 94.

The paper feed test was carried out using the papers obtained in the examples and the comparative examples. As a result, Example 1 was ○, Example 2 and Example 3 were ◎, and Comparative Examples were all ×.

Claims (14)

A paper using wood pulp as a raw material, wherein the average deviation (MMD) of the friction coefficient of the surface measured by the KES method is 0.022 or less, and the texture index of the surface is 90 or more. For example, in the paper of claim 1, wherein the above MMD is 0.018 or less. For example, the paper of claim 1 or 2, wherein the above texture index is 100-210. A paper according to any one of claims 1 to 3, which has a basis weight of 20 to 80 g/m ² . A paper according to any one of claims 1 to 4, which is a spacer paper. For example, the paper of the fifth item of the patent application is a spacer paper for metal plates. For example, the paper of the fifth paragraph of the patent application is a spacer paper for printing plates. For example, the paper of the fifth item of the patent application is a spacer paper for glass plates. The paper of claim 8, wherein the glass plate is for display. The paper of claim 9, wherein the display is a TFT liquid crystal display or an organic EL display. A laminate comprising at least one of the papers of any one of claims 1 to 10, and at least one metal plate, printing plate or glass plate. The laminate according to claim 11, wherein the metal plate, the printing plate or the glass plate is present in plurality, and the paper is present between the plurality of metal plates, the printing plate or the glass plate. A method of protecting a metal plate, a printing plate or a glass plate, comprising the step of inserting the paper of any one of claims 1 to 10 between a plurality of metal plates, printing plates or glass plates. A supply method of paper using wood pulp as a raw material, comprising: a step of holding an end portion of the paper layer by a holding means, and moving the holding means away from a surface of the paper or The step of moving in the direction of the extension surface; the average deviation (MMD) of the friction coefficient measured by the KES method on the surface of the paper is set to 0.022 or less, and the texture index is set to 90 or more.