WO2018181670A1

WO2018181670A1 - Glass plate slip sheet and production method therefor

Info

Publication number: WO2018181670A1
Application number: PCT/JP2018/013129
Authority: WO
Inventors: 浅井　靖彦; 幸恵鈴木; 孝之西村
Original assignee: 特種東海製紙株式会社
Priority date: 2017-03-30
Filing date: 2018-03-29
Publication date: 2018-10-04
Also published as: JPWO2018181670A1; KR20180135856A; TWI763813B; TW201840928A; JP6918925B2; CN110446667A

Abstract

The present invention pertains to a glass plate slip sheet having timber pulp as the raw material therefor and a silicone content of no more than 0.5 ppm. The difference between the number of silcone-containing non-continuous areas having a diameter of at least 30 µm upon one surface and the number of silicone-containing non-continuous areas having a diameter of at least 30 µm upon the other surface is no more than 5/1,000 m2. This glass plate slip sheet is capable of solving the problems caused by differences in the state of the front and rear surfaces thereof.

Description

Interleaving paper for glass plate and method for producing the same

In the process of laminating and storing and transporting a plurality of glass plates for flat panel displays such as liquid crystal displays, plasma displays, organic electroluminescence (organic EL) displays, etc., the paper for packaging the glass plates, and The present invention relates to paper sandwiched between glass plates and the production of these papers.

In general, in the storage process of laminating and storing a plurality of glass plates for flat panel displays, the distribution process of transporting them with trucks, etc., the glass plates are subjected to impacts and come into contact with each other. In order to prevent the glass surface from being contaminated by contaminants from the outside, paper called interleaving paper is sandwiched between glass plates.

Glass plates for flat panel displays are used for high-definition displays compared to general architectural window glass plates, vehicle window glass plates, etc., so impurities on the glass surface are as much as possible on the glass surface. It is required to have a clean surface, and to have excellent flatness for high-speed response and widening of the viewing angle.

Several slip sheets have already been proposed for use in such applications, as slip sheets that can prevent the glass plate from cracking and scratching the surface, and slip sheets that do not contaminate the glass surface. For example, Patent Document 1 discloses a technique for forming a fluorine coating film on the surface of a slip sheet. Further, Patent Document 2 includes a paper sheet in which a polyethylene resin foam sheet and a polyethylene resin film are bonded, and Patent Document 3 includes a paper made of pulp containing 50 mass% or more of exposed chemical pulp. In addition, there is a paper for glass containing a specific alkylene oxide adduct and water-soluble polyether-modified silicone, and Patent Document 4 defines the amount of resin in the paper and considers contamination of the glass surface. A glass sheet slip sheet using the prepared raw materials is disclosed.

JP 2012-188785 A JP 2010-242057 A JP 2008-208478 A JP 2006-44674 A

For example, it is known that problems such as disconnection may occur if the glass plate surface is contaminated during the production of a color filter substrate in an array process, which is one of the manufacturing processes of a TFT liquid crystal display. The color filter substrate is made by forming a thin film such as a semiconductor film, ITO film (transparent conductive film), insulating film, aluminum metal film, etc. on a glass plate by sputtering or vacuum evaporation, but it is a contaminant on the glass plate surface. This is because a circuit pattern formed from a thin film is disconnected or a short circuit occurs due to a defect in the insulating film. In the production of a color filter substrate, a photolithography pattern is formed on a glass plate. If contaminants are present on the glass plate surface during resist coating in this process, pinholes are generated in the resist film after exposure and development. As a result, disconnection or short circuit occurs. Similar problems have been confirmed in the manufacture of organic EL displays. An organic EL display is manufactured by forming a thin film such as an ITO anode, an organic light emitting layer, or a cathode on a glass substrate by sputtering, vapor deposition, printing, etc., and therefore does not emit light when a foreign substance that obstructs the thin film exists on the glass substrate surface. Problems arise.

Such a cause of contamination of the glass plate has been difficult to identify, but it has been found that one of the causes is a fine foreign substance that is transferred from the surface of the glass plate interleaf to the surface of the glass plate.

Also, it has been found that one such foreign material is a silicone-based material.

By the way, when sandwiching the glass sheet interleaf paper between the glass sheets, if there is a difference in the physical state of the front and back surfaces of the interleaving sheet, consider that the specific surface of the interleaf sheet is in contact with the surface of the glass sheet. There may be a need. For example, a glass plate for a flat panel display has a fine circuit formed on its surface, so even if it is a very small amount of foreign matter, its adhesion is particularly avoided. If there is more foreign matter on one surface than the other surface, there is an increased risk that the foreign matter will be transferred to the surface of the glass plate. Care should be taken to bring the slip sheet into contact with the surface of the glass plate so as to be in contact. In this case, it is conceivable that two interleaving papers are sandwiched between the glass plates and the surface of each interleaving paper having the smaller amount of foreign matter is directed to the glass plate, but the amount of interleaving paper used increases. Since the weight of the laminate of the slip sheet and the glass plate increases, it is not preferable in terms of handling.

This invention makes it the subject to solve said problem originating in the difference in the state of the front and back surfaces of the paper for glass plates. In particular, an object of the present invention is to provide a slip sheet for a glass plate that may be brought into contact with either the front or back glass plate.

Therefore, as a result of intensive studies, the present inventors reduce the amount of silicone-containing foreign matter contained in the glass sheet slip sheet, and suppress the difference in the amount of foreign matter present on the front and back surfaces of the slip sheet. Thus, it was found that the difference in the state of the front and back surfaces of the interleaf paper for glass plate can be suppressed, and the interleaf paper for glass plate that can be brought into contact with the glass plate can be provided, thereby completing the present invention.

A first aspect of the present invention is a glass sheet interleaf made of wood pulp, wherein the silicone content is 0.5 ppm or less, and the silicone-containing discontinuity having a diameter of 30 μm or more on one surface This is a slip sheet for glass plate in which the difference between the number of regions and the number of silicone-containing discontinuous regions having a diameter of 30 μm or more on the other surface is within 5/1000 m ² .

It is preferable that the number of the discontinuous regions on one surface of the glass sheet interleaf is 15/1000 m ² or less.

It is preferable that the content of the silicone in the glass sheet interleaf is 0.1 ppm or less.

The silicone is preferably silicone oil. The silicone oil is preferably dimethylpolysiloxane.

The thickness of the glass sheet interleaf is preferably 20 to 200 μm.

The glass sheet slip sheet preferably has an average deviation (MMD) of the friction coefficient of the surface by the KES method of 0.022 or less.

The glass plate is preferably for a display, and more preferably for a TFT liquid crystal display or an organic EL display.

A second aspect of the present invention is a method for producing the above glass sheet interleaving paper,
A slurry preparation step for preparing a wood pulp slurry;
A sheet forming step for forming the slurry into a sheet;
A wet paper web preparation step for dehydrating the sheet to form a wet paper web;
Including at least a drying step of drying the wet paper to obtain the slip sheet;
The present invention relates to a manufacturing method in which dehydration is performed from both sides of the sheet in the wet paper preparation step.

It is preferable to perform the dehydration by suction.

The difference between the suction dehydration rate on one surface of the sheet and the suction dehydration rate on the other surface is preferably 10% or less of the suction dehydration rate on the other surface.

It is preferable that the manufacturing method includes an additional suction step of further sucking both sides of the interleaving paper after the drying step.

Further, the present invention also relates to the glass sheet interleaving paper according to the first aspect of the present invention and a laminate with the glass sheet.

And this invention relates also to the protection method of the glass plate including the process of arrange | positioning the paper for glass plates of the 1st aspect of this invention between glass plates.

The slip sheet for glass plate of the present invention contains a small amount of silicone, and the difference in the number of silicone-containing discontinuous regions on the front and back surfaces of the slip sheet is suppressed. The difference in the presence state of the silicone-containing foreign matter is suppressed. Therefore, either of the front and back surfaces of the slip sheet for glass plate of the present invention may be brought into contact with the glass plate. Thereby, the paper for glass plates of this invention is excellent in the handleability.

In addition, the interleaf paper for glass plates is originally wound in a roll shape and shipped, but in the wound state, the front and back surfaces of the interleaf paper are in contact with each other. If there is a large amount of silicone-containing foreign matter, even if the surface of the slip sheet is brought into contact with the surface of the glass plate, the silicone-containing foreign matter on the back surface of the slip sheet is transferred to the surface in the rolled-up state, and the surface is cleaned. May decrease.

However, the interleaving paper for glass plate of the present invention has a roll shape since the transfer of silicone-containing foreign matter from one surface of the interleaving paper to the other surface is suppressed even when the interleaving paper is rolled up. There is no need to worry about a decrease in the cleanliness of the surface of the interleaving paper due to winding.

Furthermore, since the slip sheet for glass plate of the present invention has a small amount of silicone-containing foreign matter, it is possible to effectively suppress or avoid the transfer of fine foreign matter that becomes a problem from the slip sheet to the glass plate. In this way, by suppressing or avoiding the transfer of fine foreign matter that becomes a problem on the glass plate, it becomes possible to prevent circuit disconnection of a color film or the like in a manufacturing process of a TFT liquid crystal display or the like.

Wood pulp usable in the present invention includes softwood bleached kraft pulp (NBKP), hardwood bleached kraft pulp (LBKP), softwood bleached sulfite pulp (NBSP), hardwood bleached sulfite pulp (LBSP), and thermomechanical pulp (TMP). These are wood pulps such as single or mixed. This wood pulp is mainly used, and if necessary, non-wood pulp such as hemp, bamboo, cocoon, kenaf, cocoon, cocoon and cotton, modified pulp such as cationized pulp, mercerized pulp, rayon, vinylon, nylon, Synthetic fibers such as acrylic and polyester, chemical fibers, or microfibrillated pulp can be used alone or in combination. However, if the pulp contains a large amount of resin, the resin may contaminate the glass plate surface. Therefore, chemical pulp with as little resin as possible, for example, softwood bleached kraft pulp, is used alone. It is preferable to do. Also, high yield pulp such as groundwood pulp is not preferred because it contains a large amount of resin. In addition, mixing synthetic fibers and chemical fibers improves cutting performance and improves workability when making interleaving paper into a lithographic plate. However, care must be taken because recyclability deteriorates in terms of waste disposal. .

The form of the wood pulp is not particularly limited, and can take any form such as a sheet, a block, or a flake. The sheet-like pulp can be obtained using, for example, a pulp machine having four steps of wire part, press part, dry part, and finishing. In the wire part, pulp fiber is made using a long mesh or a vacuum filter, and in the press part, it is dehydrated using a roll press. In the dry part, it is dried with a cylinder dryer or a fract dryer, and finally both ends of the sheet pulp are cut off and wound up on a roll. Such a method is described in detail in the “Paper Pulp Manufacturing Technology Series” published by the Paper Pulp Technology Association and “Paper Pulp Manufacture”. The block-like pulp can be obtained, for example, by laminating the sheet-like pulp, and the flake-like pulp can be obtained, for example, by pulverizing the sheet-like pulp.

The thickness of the sheet pulp is preferably 0.7 to 1.5 mm, more preferably 0.9 to 1.3 mm, and even more preferably 1.0 to 1.2 mm. .

The basis weight of the sheet pulp is preferably 400 to 1300 g / m ² , more preferably 500 to 1200 g / m ² , still more preferably 500 to 1100 g / m ² , and 500 to 1000 g. / M ² is more preferable, and 700 to 1000 g / m ² is even more preferable.

In the slip sheet for glass plate of the present invention, the content of silicone contained in the slip sheet is limited to 0.5 ppm or less based on the weight of the slip sheet. The silicone content is preferably 0.4 ppm or less, more preferably 0.3 ppm or less, even more preferably 0.2 ppm or less, and particularly preferably 0.1 ppm or less.

On the other hand, silicone may be present in the interleaving paper for a glass plate of the present invention as long as it is in a very small amount that does not cause a problem. Therefore, the content of silicone may not be zero. For example, the silicone content may be 0.1 ppb.

The silicone content is based on the absolute dry mass of the slip. In the present invention, “absolutely dry” means a state where moisture is not substantially present in an object to be dried by drying.

The silicone content can be determined, for example, by subjecting the slip sheet to an extraction step in an organic solvent capable of silicone extraction and quantifying the amount of extracted silicone.

The shape of the silicone-containing discontinuous region in the present invention is arbitrary, and may be various shapes such as a circle, an ellipse, and a square, but is preferably a circle or an ellipse. Specifically, the discontinuous regions may be scattered in the form of dots (dots) or spots (spots).

The silicone-containing discontinuous region in the present invention has a diameter of 30 μm or more. In the present invention, the “diameter” of the discontinuous region means an equivalent area circle diameter (a diameter of a circle having an area equal to the area of the discontinuous region). The diameter of the discontinuous region is preferably 25 μm or more, more preferably 20 μm or more, still more preferably 15 μm or more, still more preferably 10 μm or more, still more preferably 5 μm or more, still more preferably 1 μm or more, and 0.5 μm or more. Is particularly preferred. When the discontinuous region is circular, the diameter is “diameter”. When the discontinuous region is non-circular, the equivalent area circle diameter (the diameter of a circle having the same area as the discontinuous region) is preferably 25 μm or more, preferably 20 μm or more, more preferably 15 μm or more. 10 μm or more is even more preferable, 5 μm or more is even more preferable, 1 μm or more is even more preferable, and 0.55 μm or more is particularly preferable. The diameter and area of the discontinuous region can be measured by, for example, microscopy.

The diameter of the discontinuous region is preferably 10 mm or less, more preferably 5 mm or less, still more preferably 3 mm or less, still more preferably 1 mm or less, still more preferably 500 μm or less, still more preferably 100 μm or less, and particularly preferably 50 μm or less. preferable. When the discontinuous region is circular, the diameter is preferably 10 mm or less, more preferably 5 mm or less, still more preferably 3 mm or less, still more preferably 1 mm or less, and even more preferably 500 μm or less. 100 μm or less is even more preferable, and 50 μm or less is particularly preferable. When the discontinuous region is non-circular, the equivalent circle diameter is preferably 10 mm or less, preferably 5 mm or less, more preferably 3 mm or less, still more preferably 1 mm or less, even more preferably 500 μm or less, and even more preferably 100 μm. The following is still more preferable, and 50 μm or less is particularly preferable.

It is preferable that a silicone-containing discontinuous region having a diameter exceeding 10 mm does not exist on the surface of the glass sheet interleaf of the present invention.

In the slip sheet for glass plate of the present invention, the difference between the number of discontinuous regions containing silicone of 30 μm or more on one surface and the number of discontinuous regions containing silicone of 30 μm or more on the other surface is 5 / 1000m ^{2 or} less, preferably 4 pieces / 1000m ^{2 or} less, more preferably 3 pieces / 1000m ^{2 or} less, more preferably 2 pieces / 1000m ^{2 or} less, preferably 1 piece / 1000m ^{2 or} less. Even more preferably. That is, in the slip sheet for glass plate of the present invention, the amount of the silicone-containing discontinuous region on one surface does not vary so much that the amount of the discontinuous region on the other surface falls within the above specific range. It is preferable. Here, the “abundance” means the number of the discontinuous regions containing silicone per unit area of the surface of the slip sheet. For example, a plurality of locations on the surface of the slip sheet for glass plate are magnified by an electron microscope. It can be determined by observing and averaging the number of silicone-containing discontinuous regions observed at that location per unit area.

The silicone-containing discontinuous region on the surface of the slip sheet for glass plate according to the first aspect of the present invention has, for example, an affinity for silicone on the surface of the slip sheet, but has no affinity for the slip sheet (typically Apply a hydrophobic or coloring agent and measure the colored or colored area on the surface, or have affinity for the interleaf and the silicone on the surface of the interleaf It can be determined by applying a colorant or color former without any color (typically hydrophilic) and measuring the non-colored or non-colored area on the surface.

The interleaving paper for glass plate of the present invention has a small amount of silicone contained, and the variation in the abundance of the silicone-containing discontinuous regions on the front and back surfaces of the interleaving paper is suppressed. Differences in the physical state of the front and back surfaces of the slip sheet are suppressed. Therefore, in the slip sheet for glass plate of the present invention, the abundance of the silicone-containing foreign matter is not greatly different between the front and back surfaces of the slip sheet. Accordingly, the interleaving paper for glass plate of the present invention may be brought into contact with either the front or back surface of the glass plate.

The foreign matter that is a problem in the present invention includes silicone. The silicone-containing discontinuous region on the surface of the interleaf paper for the glass plate of the present invention corresponds to the foreign matter that is a problem of the present invention.

Although the kind of silicone contained in the silicone containing discontinuous area | region in the surface of the paper for glass plates of this invention is not specifically limited, For example, silicone oil is mentioned. Silicone oil is hydrophobic and its molecular structure may be cyclic, linear or branched. Kinematic viscosity at 25 ° C. of the silicone oil is usually in the range of 0.65 ~ 100,000mm ² / s, it may be in the range of 0.65 ~ ^10,000mm 2 / s.

Examples of the silicone oil include linear organopolysiloxanes, cyclic organopolysiloxanes, and branched organopolysiloxanes.

Examples of the linear organopolysiloxane, cyclic organopolysiloxane, and branched organopolysiloxane include the following general formulas (1), (2), and (3):

R ¹ ₃ SiO— (R ¹ ₂ SiO) _a —SiR ¹ ₃ (1)

R ¹ _(4-c) Si (OSiR ¹ ₃ ) _c (3)

(Where
Each R ¹ is independently a hydrogen atom, a hydroxyl group, or a group selected from a group represented by a substituted or unsubstituted monovalent hydrocarbon group or an alkoxy group;
a is an integer of 0 to 1000;
b is an integer of 3 to 100,
c is an integer of 1 to 4, preferably an integer of 2 to 4)
The organopolysiloxane represented by these is mentioned.

The substituted or unsubstituted monovalent hydrocarbon group is typically a substituted or unsubstituted one having 1 to 30 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms. A saturated saturated hydrocarbon group; a substituted or unsubstituted monovalent unsaturated hydrocarbon group having 2 to 30 carbon atoms, preferably 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms; A monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, more preferably 6 to 12 carbon atoms.

Examples of the monovalent saturated hydrocarbon group having 1 to 30 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. A linear or branched alkyl group such as a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group and a decyl group, and a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group and a cyclooctyl group. Can be mentioned.

Examples of the monovalent unsaturated hydrocarbon group having 2 to 30 carbon atoms include vinyl, 1-propenyl, allyl, isopropenyl, 1-butenyl, 2-butenyl, pentenyl, and hexenyl groups. Linear or branched alkenyl groups such as cyclopentenyl group, cyclohexenyl group and the like cycloalkenyl group; cyclopentenylethyl group, cyclohexenylethyl group, cyclohexenylpropyl group and the like cycloalkenylalkyl group; and ethynyl group, Alkynyl groups such as propargyl group can be mentioned.

Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include aryl groups such as a phenyl group, a tolyl group, a xylyl group, and a mesityl group. A phenyl group is preferred. In addition, in this specification, the aromatic hydrocarbon group includes a group in which an aromatic hydrocarbon and an aliphatic saturated hydrocarbon are combined in addition to a group consisting of only an aromatic hydrocarbon. Examples of the group in which an aromatic hydrocarbon and a saturated hydrocarbon are combined include an aralkyl group such as a benzyl group or a phenethyl group.

The hydrogen atom on the monovalent hydrocarbon group may be substituted with one or more substituents, and examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom and an iodine atom), a hydroxyl group , Carbinol group, epoxy group, glycidyl group, acyl group, carboxyl group, amino group, methacryl group, mercapto group, amide group, oxyalkylene group and the like. Specifically, 3,3,3-trifluoropropyl group, 3-chloropropyl group, 3-hydroxypropyl group, 3- (2-hydroxyethoxy) propyl group, 3-carboxypropyl group, 10-carboxydecyl group And 3-isocyanatopropyl group.

Examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group, but a methoxy group or an ethoxy group is preferable, and a methoxy group is more preferable.

More specifically, the linear organopolysiloxane may be a trimethylsiloxy group-blocked dimethylpolysiloxane having a molecular chain at both ends (a low-viscosity dimethylsilicone such as 2 mPa · s or 6 mPa · s to a high viscosity such as 1 million mPa · s). ), Organohydrogenpolysiloxane, trimethylsiloxy group-capped methylphenyl polysiloxane with both molecular chains, trimethylsiloxy group-capped dimethylsiloxane / methylphenylsiloxane copolymer with both molecular chains, trimethylsiloxy group-capped diphenylpolysiloxane with both molecular chains , A trimethylsiloxy group-capped dimethylsiloxane / diphenylsiloxane copolymer, both ends of a molecular chain, trimethylpentaphenyltrisiloxane, phenyl (trimethylsiloxy) siloxane, Polyalkylpolysiloxane, trimethylsiloxy group-capped dimethylpolysiloxane / methylalkylsiloxane copolymer with both ends of the molecular chain, trimethylsiloxy group-capped dimethylsiloxane / methyl (3,3,3-trifluoropropyl) siloxane with molecular chain at both ends Combined, α, ω-dihydroxypolydimethylsiloxane, α, ω-diethoxypolydimethylsiloxane, 1,1,1,3,5,5,5-heptamethyl-3-octyltrisiloxane, 1,1,1,3 , 5,5,5-heptamethyl-3-dodecyltrisiloxane, 1,1,1,3,5,5,5-heptamethyl-3-hexadecyltrisiloxane, tristrimethylsiloxymethylsilane, tristrimethylsiloxyalkylsilane, Tetrakistrimethylsiloxysilane, tetramethyl-1, -Dihydroxydisiloxane, octamethyl-1,7-dihydroxytetrasiloxane, hexamethyl-1,5-diethoxytrisiloxane, hexamethyldisiloxane, octamethyltrisiloxane, higher alkoxy modified silicone, higher fatty acid modified silicone, dimethiconol, etc. Is done.

Cyclic organopolysiloxanes include hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), 1,1-diethylhexamethyl. Cyclotetrasiloxane, phenylheptamethylcyclotetrasiloxane, 1,1-diphenylhexamethylcyclotetrasiloxane, 1,3,5,7-tetravinyltetramethylcyclotetrasiloxane, 1,3,5,7-tetramethylcyclotetra Siloxane, 1,3,5,7-tetracyclohexyltetramethylcyclotetrasiloxane, tris (3,3,3-trifluoropropyl) trimethylcyclotrisiloxane, 1,3,5,7-tetra (3-methacryloxyp Pyr) tetramethylcyclotetrasiloxane, 1,3,5,7-tetra (3-acryloxypropyl) tetramethylcyclotetrasiloxane, 1,3,5,7-tetra (3-carboxypropyl) tetramethylcyclotetrasiloxane 1,3,5,7-tetra (3-vinyloxypropyl) tetramethylcyclotetrasiloxane, 1,3,5,7-tetra (p-vinylphenyl) tetramethylcyclotetrasiloxane, 1,3,5, 7-tetra [3- (p-vinylphenyl) propyl] tetramethylcyclotetrasiloxane, 1,3,5,7-tetra (N-acryloyl-N-methyl-3-aminopropyl) tetramethylcyclotetrasiloxane, 1 , 3,5,7-Tetra (N, N-bis (lauroyl) -3-aminopropyl) tetramethyl Cyclotetrasiloxane and the like.

Examples of the branched organopolysiloxane include methyltristrimethylsiloxysilane, ethyltristrimethylsiloxysilane, propyltristrimethylsiloxysilane, tetrakistrimethylsiloxysilane, and phenyltristrimethylsiloxysilane.

As the silicone oil in the present invention, dimethylpolysiloxane, diethylpolysiloxane, methylphenylpolysiloxane, polydimethyl-polydiphenylsiloxane copolymer, polymethyl-3,3,3-trifluoropropylsiloxane and the like are preferable. As the silicone in the present invention, dimethylpolysiloxane is typical.

The silicone oil in the present invention may be a modified silicone oil. Examples of the modified silicone oil include polyoxyalkylene-modified silicone oil.

The polyoxyalkylene-modified silicone oil is a silicone oil having a polyoxyalkylene group bonded to the molecule via a silicon-carbon bond, and preferably exhibits water solubility at room temperature, specifically at 25 ° C. More preferably, it is a nonionic one.

Specifically, the polyoxyalkylene-modified silicone oil is, for example, a copolymer of a silicone oil composed of linear or branched siloxane and a polyoxyalkylene, and there are various types. ) Is preferred.

R ² ₃ SiO— (R ¹ ₂ SiO) _d — (R ¹ ASiO) _e —SiR ² ₃ (4)

(Where
R ¹ is independently the same as above,
Each R ² is independently R ¹ or A;
A is independently a group represented by R ³ G, R ³ is a substituted or unsubstituted divalent hydrocarbon group, and G is a carbon number of 2 to 5 such as ethylene oxide or propylene oxide. A polyoxyalkylene group comprising at least one alkylene oxide of
d represents an integer of 1 to 500;
e represents an integer of 1 to 50).

Examples of the substituted or unsubstituted divalent hydrocarbon group include a linear or branched divalent hydrocarbon group having 1 to 30 carbon atoms. Specific examples include a methylene group, a dimethylene group, and trimethylene. A linear or branched alkylene group having 1 to 30 carbon atoms such as a group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group; vinylene group, arylene group, butenylene group, Alkenylene groups having 2 to 30 carbon atoms such as hexenylene group and octenylene group; arylene groups having 6 to 30 carbon atoms such as phenylene group and diphenylene group; alkylene arylene groups having 7 to 30 carbon atoms such as dimethylenephenylene group And hydrogen atoms bonded to carbon atoms of these groups are at least partially halogen atoms such as fluorine, hydroxyl groups, The carbinol group, epoxy group, a glycidyl group, an acyl group, a carboxyl group, an amino group, a methacryl group, a mercapto group, an amide group, and substituted groups in the organic group containing an oxyalkylene group or the like. The divalent hydrocarbon group is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, and more preferably an alkylene group having 3 to 5 carbon atoms.

For example, specific examples of the polyoxyalkylene-modified silicone oil include the following.

(Where
x is 20 to 160, y is 1 to 25, and the value of x / y is 50 to 2,
A is, for example, — (CH ₂ ) ₃ O— (CH ₂ CH ₂ O) _m — (CH ₂ CH ₂ CH ₂ O) _n —R ⁴ , where m is 7 to 40, n is 0 to 40, m + n The value of is at least 1 and may be graft polymerized or randomly polymerized, and R ⁴ represents a hydrogen atom or the above substituted or unsubstituted monovalent hydrocarbon group. Preferably, m is 7-30 and n is 0-30)

In addition, examples of the modified silicone oil include aminoalkyl-modified silicone oil.

The aminoalkyl-modified silicone oil is a silicone oil in which an aminoalkyl group is bonded to the molecule via a silicon-carbon bond, and preferably exhibits a viscosity of 10 to 100,000 cs at room temperature, specifically at 25 ° C. It is.

As the aminoalkyl silicone oil, in the above formula (4), G is represented by the formula: — (NR ⁴ CH ₂ CH ₂ ) _z NR ⁴ ₂ (wherein R ⁴ is independently as defined above, z Is a number of 0 ≦ z ≦ 4).

The thickness of the slip sheet for glass plate of the present invention is preferably 20 to 200 μm, more preferably 30 to 150 μm, and still more preferably 40 to 200 μm. Thus, by using a relatively thin slip sheet, the difference in physical state between the front and back of the slip sheet can be further suppressed.

The basis weight of the interleaving paper for glass plate of the present invention is preferably 20 to 80 g / m ² , more preferably 25 to 70 g / m ² , and even more preferably 30 to 60 g / m ^2. preferable.

In the slip sheet for glass plate of the present invention, the average deviation (MMD) of the friction coefficient of the surface by the KES method is preferably 0.022 or less, preferably 0.020 or less, and 0.019 or less. More preferably, it is still more preferably 0.018 or less, and still more preferably 0.017 or less. MMD uses a friction tester (KES-SE manufactured by Kato Tech Co., Ltd.), and a 10 mm square friction element consisting of a bundle of piano wires with a diameter of 0.5 mm is fixed with a tension of 20 g / cm. Is an average deviation value of the coefficient of friction measured by moving 2 cm at a sample moving speed of 0.1 cm / second in the same direction as the direction in which the tension is applied while contacting with a contact pressure of 50 g / cm ² . When this MMD is large, it means that the coefficient of friction of the paper surface varies greatly depending on the position of the paper surface. Microscopically, it means that minute irregularities on the surface of the paper increase. By providing fine irregularities on the surface of the slip sheet in this way, the friction coefficient between the surface of the glass plate and the surface of the slip sheet is reduced, and the removal work when removing the slip sheet from the surface of the glass sheet is facilitated. . If the MMD exceeds 0.022, minute irregularities on the surfaces of the papers increase and the catching between the papers increases, which is not preferable. For example, the MMD is preferably 0.001 to 0.022, more preferably 0.002 to 0.020, and still more preferably 0.004 to 0.019.

Although the interleaving paper for glass plate of the present invention may contain short fibers having a fiber length of 200 μm or less, the short fibers may attract foreign substances, so that the content of the short fibers is preferably limited.

The content of short fibers having a fiber length of 200 μm or less in the interleaving paper for glass plate of the present invention is preferably 10.5 wt% or less with respect to the absolute dry mass of the interleaving paper, and is 10.0 wt% or less. Is more preferable, 9.5% by weight or less is even more preferable, and 9.0% by weight or less is particularly preferable. Here, “fiber length” does not mean the average fiber length. Accordingly, all the short fibers having a fiber length of 200 μm or less have a fiber length of 200 μm or less. In other words, the maximum fiber length of the short fibers is 200 μm or less. Here, the fiber length refers to the length of the fiber when the fiber is straightened.

The average fiber diameter of the short fibers is preferably 10 μm to 50 μm, more preferably 12 μm to 40 μm, and even more preferably 15 μm to 30 μm. In addition, “average fiber diameter” here refers to a plurality of locations on the surface of the glass sheet interleaf, which are enlarged and observed by an electron microscope, and a predetermined number of fibers are randomly selected from each electron microscope image. The average fiber diameter obtained by measuring and averaging the diameters of the fibers. The number of fibers to be selected is 100 or more, preferably 150 or more, more preferably 200 or more, and even more preferably 300 or more.

The abundance of the short fibers on the surface of the interleaving paper for glass plate of the present invention is preferably 300 to 850 / cm ² , more preferably 330 to 800 / cm ² , and 350 to More preferably, it is 750 pieces / cm ² . When the amount of short fibers is relatively small, the amount of foreign matter attracted by the short fibers can be reduced.

In the slip sheet for glass plate of the present invention, the difference between the amount of the short fibers on one surface and the amount of the short fibers on the other surface is 15% of the amount of the short fibers on the other surface. Or less, more preferably 12% or less, even more preferably 10% or less. That is, in the interleaving paper for a glass plate of the present invention, it is preferable that the amount of short fibers on one surface does not vary so much as to be within the above specific range from the amount of short fibers on the other surface. Here, the “abundance” means the number of the short fibers per unit area of the surface of the slip sheet, for example, by observing a plurality of positions on the surface of the slip sheet for the glass plate with an electron microscope, It can be determined by averaging the number of short fibers observed at the location per unit area. It can also be determined by obtaining the number of short fibers of 200 μm or less per unit area from fibers dropped by rubbing a predetermined area with a sheet or the like with the surface of the interleaf facing downward. Furthermore, it can also be determined by dividing the slip sheet into two very thin sheets at the center in the thickness direction, slurrying each sheet, and measuring the number of short fibers of 200 μm or less in the slurry. Alternatively, the abundance of short fibers can also be determined by thoroughly washing the surface of a predetermined area of the glass sheet interleaf with water, and using the dropped fibers in a fiber length measuring machine.

The interleaf paper for glass plate of the present invention may contain talc, but since the surface of talc is relatively lipophilic and has a property of adsorbing silicone to form a composite, the content of talc is suppressed. It is preferable. Note that. The form of composite of talc and silicone is not particularly limited, but at least a part of talc may be covered with silicone, or silicone may penetrate at least a part of talc.

In the interleaving paper for glass plate of the present invention, the ratio of talc on one surface is preferably 3 pieces / 100 m ² or less, more preferably 2 pieces / 100 m ² or less, and 1 piece / 100 m ² or less. Is more preferably 0.8 pieces / 100 m ² or less, still more preferably 0.6 pieces / 100 m ² or less, and 0.4 pieces / 100 m ² or less. Even more preferably, and particularly preferably 0.2 pieces / 100 m ² or less.

In the glass plate for a slip sheet of the present invention, it is preferable that the difference between the existing ratio of the talc in the talc existence ratio and the other surface of the one surface is 5 / 100m ² within four / 100m It is more preferably ^{2 or} less, more preferably 3 pieces / 100 m ^{2 or} less, more preferably 2 pieces / 100 m ^{2 or} less, still more preferably 1 piece / 100 m ^{2 or} less. That is, in the slip sheet for glass plate of the present invention, it is preferable that the ratio of talc on one surface does not vary so much as to be within the above specific range from the ratio of talc on the other surface. Here, the “existence ratio” means the number of talc per unit area on the surface of the slip sheet. For example, a plurality of locations on the surface of the slip sheet for glass plate are magnified and observed by an electron microscope, Can be determined by averaging the number of talc observed in Alternatively, the talc presence ratio can also be determined by thoroughly washing the surface of a predetermined area of the glass sheet interleaf with an acidic solution such as water or concentrated sulfuric acid and counting the talc that has fallen.

The talc in the present invention is not particularly limited. Talc is called “hydrous magnesium silicate”, and the chemical formula can be represented by 4SiO ₂ .3MgO.H ₂ O. The chemical composition differs somewhat depending on the place of production, and the theoretical values are weight ratios of SiO ₂ 64.4%, MgO 31.8%, ignition loss (water) 4.7%. Talc is also called talc.

The average particle diameter of the talc is not particularly limited, but is preferably 1 to 10 μm, more preferably 1 to 8 μm, still more preferably 1 to 6 μm, and particularly preferably 1 to 4 μm. The average particle diameter may be a volume average particle diameter and can be measured, for example, by a laser diffraction / scattering method.

The surface area of the talc is not particularly limited, but the specific surface area by the BET method is preferably 1 m ² / g or more, more preferably 10 m ² / g or more, and still more preferably 20 m ² / g or more.

The density of the talc is not particularly limited, but the apparent density based on JIS K5101 is preferably 1 g / ml or less, more preferably 0.8 g / ml or less, still more preferably 0.6 g / ml or less, and 0.4 g / ml. Even more preferably, it is even more preferably 0.2 g / ml or less.

The average particle size of the composite form of the talc and the hydrophobic substance is preferably 30 μm or more, more preferably 40 μm or more, and even more preferably 50 μm or more.

The slip sheet for glass plate of the present invention can be produced on the basis of a usual method such as a papermaking method.

The second aspect of the present invention is a method for producing a glass sheet interleaving paper,
A slurry preparation step for preparing a wood pulp slurry;
A sheet forming step for forming the slurry into a sheet;
A wet paper web preparation step for dehydrating the sheet to form a wet paper web;
Including at least a drying step of drying the wet paper to obtain the slip sheet;
In the wet paper preparation step, the dehydration is performed from both sides of the sheet slurry.

In the slurry preparation step, a wood pulp slurry can be prepared by a conventionally known method. For example, in the slurry preparation step, cellulose fibers constituting the wood pulp are disaggregated to prepare an aqueous suspension to prepare a slurry.

In addition, as long as the performance of the present invention is not impaired, the above-mentioned slurry, if necessary, an adhesive, an antifungal agent, an antifoaming agent, a filler, a wet paper strength enhancer, a dry paper strength enhancer, a sizing agent, Coloring agents, fixing agents, yield improvers, slime control agents and the like can be added. In addition, it is preferable to pay close attention when adding these chemicals so that insects, dust and the like are not mixed.

In general, wood pulp and interleaf paper often contain silicone. This is because a silicone-based antifoaming agent is frequently used as an antifoaming agent used to prevent deterioration in cleaning ability due to generation of foam in the production process of wood pulp and interleaf paper, particularly in the cleaning process. Antifoam-derived silicone remains in the pulp and interleaf. The silicone-based antifoaming agent is produced, for example, by mixing a modified silicone, a surfactant or the like with a mixture of silicone oil and hydrophobic silica.

In the second aspect of the present invention, a non-silicone antifoaming agent is used as an antifoaming agent when an antifoaming agent is used in order to reduce the silicone content contained in the glass sheet interleaf to 0.5 ppm or less. Can be used. Furthermore, it is preferable to use wood pulp obtained using a non-silicone antifoaming agent.

Examples of non-silicone-based antifoaming agents include mineral oil-based antifoaming agents, higher alcohol-based antifoaming agents, fatty acid-based antifoaming agents, fatty acid ester-based antifoaming agents, amide-based antifoaming agents, and amine-based antifoaming agents. , Phosphate ester defoamers, metal soap defoamers, sulfonate ester defoamers, polyether defoamers and vegetable oil defoamers.

The mineral oil-based antifoaming agent includes, for example, mineral oil such as hydrocarbon oil, mineral wax and the like.

Higher alcohol-based antifoaming agents include, for example, octyl alcohol, hexadecyl alcohol and the like.

The fatty acid-based antifoaming agent includes, for example, palmitic acid, oleic acid, stearic acid and the like.

The fatty acid ester antifoaming agent includes, for example, isoamyl stearate, glycerin monoricinoleate, sorbitol monolaurate, soliitol trioleate and the like.

The amide antifoaming agent includes, for example, acrylate polyamine.

The amine-based antifoaming agent includes, for example, diallylamine.

The phosphate ester antifoaming agent includes, for example, tributyl phosphate, sodium octyl phosphate, and the like.

The metal soap antifoaming agent includes, for example, aluminum stearate, calcium stearate, potassium oleate and the like.

Examples of the sulfonic acid ester-based antifoaming agent include sodium lauryl sulfonate, sodium dodecyl sulfonate, and the like.

Polyether-based antifoaming agents include, for example, polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene (Poly) oxyalkylene alkyl ethers such as 2-ethylhexyl ether, higher alcohols having 8 or more carbon atoms and secondary alcohols having 12 to 14 carbon atoms such as oxyethyleneoxypropylene adducts; polyoxypropylene phenyl ether, polyoxy (Poly) oxyalkylene (alkyl) aryl ethers such as ethylene nonylphenyl ether; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-he Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylene alcohols such as syn-2,5-diol and 3-methyl-1-butyn-3-ol; diethylene glycol oleate, diethylene glycol laurate, ethylene glycol distearate (Poly) oxyalkylene fatty acid esters such as polyoxyethylene sorbitan monolaurate, (poly) oxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan trioleate; polyoxypropylene methyl ether sodium sulfate, polyoxyethylene (Poly) oxyalkylene alkyl (aryl) ether sulfate esters such as sodium dodecylphenol ether sulfate; (poly) oxyethylene Nsutearirurin acid esters of (poly) oxyalkylene alkyl phosphoric acid esters; polyoxyethylene such as polyoxyethylene lauryl amine (poly) oxyalkylene alkyl amines; containing polyoxyalkylene amide.

Plant oil-based antifoaming agents include, for example, vegetable oils such as soybean oil, corn oil, coconut oil, linseed oil, rapeseed oil, cottonseed oil, sesame oil, castor oil and the like.

Further, the non-silicone antifoaming agent can include inorganic particles such as hydrophobic silica. As the hydrophobic silica, it is preferable to use silica hydrophobized by substituting silanol groups of hydrophilic silica with alkyl groups such as methyl groups.

The non-silicone antifoaming agent can contain a surfactant or the like as necessary. Accordingly, the non-silicone antifoaming agent may be an emulsion type.

When preparing the slurry, if the beating of the wood pulp is advanced, the effect of increasing the paper interlayer strength can be expected. However, if fine fibers increase by advancing beating, there is a possibility that inconveniences such as attracting foreign substances or generating paper dust during use as interleaving paper, it is not preferable to advance the beating degree more than necessary. . In the present invention, the preferred beating degree is 300 to 650 ml c. s. f. It is.

In the sheet forming step in which the slurry is formed into a sheet, the sheet can be formed by a conventionally known method. For example, by discharging the slurry onto a flat wire (for example, a long net paper machine) or by scooping a sheet from the slurry with a wire wound around a cylindrical cylinder (for example, a circular paper machine) , You can get a sheet.

In the second aspect of the present invention, dehydration is performed from both sides of the sheet in a wet paper preparation step in which the sheet is dehydrated to form a wet paper. Thereby, the silicone containing foreign material contained in the said sheet | seat is effectively removed from both surfaces of a sheet | seat. And the number of silicone-containing discontinuous regions having a diameter of 30 μm or more on one surface of the interleaving paper for glass plate obtained by the second aspect of the present invention and the silicone-containing discontinuous regions having a diameter of 30 μm or more on the other surface The difference from the number can be within 5 pieces / 1000 m ² .

The method of dehydration is arbitrary, and a conventionally known method can be used. For example, the sheet can be dehydrated by pressing with a roll. However, in order to effectively remove the silicone-containing foreign matter, it is preferable to perform the dehydration by suction.

In the process of dehydrating from both sides of the sheet, for example, the sheet extending in the horizontal direction is sandwiched from above and below by a net, and may be dehydrated by suction by a suction device in the vertical direction. There is a difference between the suction force to the surface and the downward suction force, and there is a possibility that more silicone-containing foreign matter may remain on the surface of the sheet that is sucked upward than the surface of the sheet that is sucked downward. Therefore, it is preferable that the sheet extending in the vertical direction is sandwiched between the nets and sucked in the left-right direction to dehydrate. In this case, it is preferable to maintain the moving direction of the wet paper so as to be in the vertical direction or in an inclined range within 30 ° from the vertical direction.

The difference between the suction dehydration rate on one surface of the sheet and the suction dehydration rate on the other surface is preferably 10% or less of the suction dehydration rate on the other surface. That is, in the method for producing a glass sheet slip sheet of the present invention, it is preferable that suction from both sides of the sheet is performed with substantially the same suction force.

The sheet forming step and the wet paper web preparation step may be performed separately using separate devices, but may be performed continuously or partially overlapping in the same device. For example, in the wire part of a paper machine, the wet paper may be formed by dewatering while placing the slurry on a wire (net) to form a sheet.

In the drying step, the interleaf paper can be obtained by drying wet paper by a conventionally known method using a dryer roll or the like.

In order to further remove the silicone-containing foreign matter that may remain on the surface of the slip sheet, the glass sheet slip sheet manufacturing method of the present invention includes an additional suction step of further sucking both surfaces of the slip sheet after the drying step. Is preferred.

Note that calendering, super calendering, soft nip calendering, embossing, and the like may be performed during and / or after papermaking of the glass sheet interleaf. Surface properties and thickness can be adjusted by processing.

The glass sheet slip sheet of the first aspect of the present invention can be efficiently manufactured by the manufacturing method of the second aspect of the present invention.

Whether or not the slip sheet obtained by the production method of the second aspect of the present invention matches the characteristics of the slip sheet for glass plate of the first aspect of the present invention is determined by using, for example, the same lot of wood pulp. A part of the interleaving paper obtained by the production method is subjected to an extraction step in a silicone extractable organic solvent as a sample, the amount of the extracted silicone is quantified, and both sides of the interleaving paper of the sample are quantified. Apply a colorant or color former that has an affinity for silicone but no affinity for slip paper (typically hydrophobic) to measure the colored or colored area on each surface, or To be determined by measuring a non-colored area or a non-colored area on each surface by applying a colorant or color former having affinity for the interleaving paper on both sides of the interleaving paper but not with silicone. Can do. The silicone content of the sample is 0.5 ppm or less, and the number of silicone-containing discontinuous regions with a diameter of 30 μm or more on one surface and the silicone-containing discontinuity with a diameter of 30 μm or more on the other surface When the difference from the number of areas is within 5 pieces / 1000 m ² , all the slip sheets prepared from the wood pulp of the lot can be recognized as the slip sheets for the glass plate according to the first aspect of the present invention. .

By the way, generally, talc is often contained in wood pulp and interleaf. This is because talc is frequently used as a pitch control agent in the production process of wood pulp and interleaf. In addition, talc is used not only as a pitch control agent but also as a filler and a pigment for paper coating, and exhibits the effect of improving the whiteness of paper and improving printing characteristics.

When the ratio of talc present on one surface of the interleaving paper obtained by the second aspect of the present invention is 3/100 m ² or less, a non-talc pitch control agent, filler, pigment, etc. may be used. it can.

Further, by performing dehydration from both sides of the sheet in the wet paper preparation step of dehydrating the sheet in the second aspect of the present invention to form a wet paper, the talc contained in the sheet is also effective from both sides of the sheet. Can be removed. Thus, to the difference between the talc existing ratio of the existence ratio and the other surface of the talc on one surface of the glass plate for slip sheet obtained by the second aspect of the present invention and five / 100 m ² within You can also.

The glass sheet slip sheet of the present invention is used by being inserted between the glass sheets. For example, the glass sheet interleaving paper is typically inserted one by one between a plurality of glass sheets to form a laminated body as a whole, and the laminated body is a target for storage and transportation. Moreover, you may package a glass plate single-piece | unit or the said laminated body using the slip sheet for glass plates of this invention. Therefore, this invention has the side surface of the protection method of a glass plate including the process of arrange | positioning (especially inserting) the said paper for glass plates between glass plates.

Although it does not specifically limit as a glass plate, It is preferable that it is a glass plate for flat panel displays, such as a plasma display panel, a liquid crystal display panel (especially TFT liquid crystal display panel), and an organic electroluminescent display panel. Fine electrodes, partition walls, etc. are formed on the surface of the glass plate for flat panel display, but by using the interleaving paper for the glass plate of the present invention, transfer of fine foreign matter that becomes a problem to the glass plate Therefore, even if a fine electrode, a partition, or the like is formed on the surface of the glass plate, inconvenience due to the foreign matter can be suppressed or avoided, and as a result, display defects can be suppressed or avoided. be able to.

In particular, the size and weight of a glass plate for a flat panel display have increased with the increase in the size of the display. However, the slip sheet for a glass plate of the present invention has the surface of such a large or heavy glass plate. It can be well protected. In particular, since the slip sheet for glass plate of the present invention has a very small content of fine silicone-containing foreign matter, it is suppressed or avoided that the foreign matter is transferred to the glass plate even when pressed by a heavy glass plate. . Therefore, the interleaving paper for a glass plate of the present invention can be suitably used for a glass plate for a flat panel display in which surface cleanliness is particularly required.

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

[Content of silicone]
The glass sheet interleaf was cut into about 1 cm square, and Soxhlet extraction was performed with hexane for about 3 and a half hours. The obtained extract was condensed with a rotary evaporator, redissolved in 1 mL of deuterated chloroform and subjected to ¹ H-NMR measurement. For this quantification, an absolute calibration method was used to prepare a calibration curve by using a deuterated chloroform solution of polydimethylsiloxane as a standard product. The NMR apparatus used was AVANCE 500 type (manufactured by Blue Car Biospin).

[Number of discontinuous areas containing silicone]
As a result of applying a 1% by weight aqueous solution of the direct dye “Rebasel First Black G” (Brancofor Japan Co., Ltd.) to the surface of the interleaving paper for glass plates, a non-colored discontinuous region with a diameter of 30 μm or more is generated. And the abundance (number per 1000 m ² ) was determined.

[Transfer test method to glass plate (transport test)]
Aluminum foam is placed on the glass mounting surface on the L-shaped frame with an angle of 75 degrees, and the mounting surface for mounting the glass plate in the vertical direction and the rear end of the mounting surface Insert a sheet of glass plate between 120 glass plates of size 680 mm x 880 mm x 0.7 mm and each glass plate toward the backrest surface extending in the vertical direction, and lean against the backrest surface so that it is parallel to the backrest surface. A fixed belt-like belt was stretched over the entire circumference from the rear end portion to the backrest surface to fix the glass plate. The gantry set as described above was entirely covered with a packaging material in order to prevent dust and dirt from entering from the outside. After that, a truck transportation test was conducted. The transportation test was conducted at a transportation distance of 1000 km (stored for 5 days in an environment of 40 ° C. × 95% RH during transportation).

[Example 1]
In a conifer bleached kraft pulp manufacturing apparatus comprising a cooking process, a washing process, an oxygen delignification reaction process, and a multistage bleaching bleaching process with chlorine dioxide and hydrogen peroxide, the drum washer immediately after the knot is removed after the cooking process An appropriate amount of a stock solution of mineral oil-based antifoaming agent “Pronal A5044” (manufactured by Toho Chemical Co., Ltd.), which is a non-silicone-based antifoaming agent, was continuously added as an antifoaming agent used in the cleaning liquid. Similarly, an appropriate amount of “Pronal A5044” was added as an antifoaming agent added to the wash press in the press washing step. In the washing step, washing with a mixed solvent of toluene and methanol and washing with solvent were repeated five times. As mentioned above, the softwood bleached kraft pulp which used the non-silicone type | system | group antifoamer in the manufacturing process was obtained. 100 parts by mass of this was prepared and disaggregated to give a beating degree of 550 mlc. s. f. 0.2 parts by mass of polyacrylamide (trade name: Polystron 1250, manufactured by Arakawa Chemical Industry Co., Ltd.) as a paper strength enhancer was added to the prepared slurry, and a 0.4% by weight pulp slurry. Was prepared. This was paper-made using a long web paper machine equipped with an on-top former in the wire part to obtain a slip sheet for a glass plate having a basis weight of 55 g / m ² . In the wire part, the difference in the dewatering rate of the on-top former on both surfaces of the wet paper was adjusted to be 10% or less (based on the dewatering rate of the upper on-top former).

[Comparative Example 1]
A glass sheet slip with a basis weight of 55 g / m ² was obtained in the same manner as in Example 1 except that the on-top former was not used.

[Comparative Example 2]
Further, a softwood obtained in the same manner as in the production of the softwood bleached kraft pulp except that the silicone-based antifoaming agent “SN Deformer 551K” (manufactured by San Nopco) was used as the antifoaming agent and the solvent was not washed. A glass sheet slip with a basis weight of 55 g / m ² was obtained in the same manner as in Example 1 except that 100 parts by weight of bleached kraft pulp was used.

The silicone content of Examples and Comparative Examples was 0.1 ppm in Example 1, 0.1 ppm in Comparative Example 1, and 2.3 ppm in Comparative Example 2. Non-colored discrete number of regions on one surface of Example 1 was 8 per 1000 m ^2, the other side was 11 per 1000 m ^2. The number of non-colored discontinuous regions on one surface of Comparative Example 1 was 8 per 1000 m ² , and the other surface was 16 per 1000 m ² . When the transfer to the glass plate of the glass sheet interleaving paper obtained in Examples and Comparative Examples was confirmed by a transportation test, an array of liquid crystal panels using the glass plate using the interleaving paper of Example 1 was formed. No disconnection of the color film was observed. On the other hand, disconnection of the color film was observed during the formation of an array of a liquid crystal panel using a glass plate using the glass sheet for Comparative Example 1 and Comparative Example 2.

Claims

It is a slip sheet for glass plate made from wood pulp,
The silicone content is 0.5 ppm or less,
The difference between the number of silicone-containing discontinuous regions having a diameter of 30 μm or more on one surface and the number of silicone-containing discontinuous regions having a diameter of 30 μm or more on the other surface is within 5/1000 m 2. paper.
The slip sheet for glass plates according to claim 1, wherein the number of discontinuous regions on one surface is 15/1000 m 2 or less.
The glass sheet interleaf according to claim 1 or 2, wherein the silicone content is 0.1 ppm or less.
The glass sheet interleaving paper according to claim 1 or 2, wherein the silicone is silicone oil.
The glass sheet interleaving paper according to claim 4, wherein the silicone oil is dimethylpolysiloxane.
3. The glass sheet interleaf according to claim 1, wherein the thickness is 20 to 200 μm.
The interleaving paper for a glass plate according to claim 1 or 2, wherein the mean deviation (MMD) of the friction coefficient of the surface by the KES method is 0.022 or less.
The glass sheet slip sheet according to claim 1 or 2, wherein the glass sheet is for display.
The glass sheet slip sheet according to claim 8, wherein the display is a TFT liquid crystal display or an organic EL display.
A laminate comprising the glass sheet interleaving paper according to any one of claims 1 to 9 and a glass sheet.
A method for protecting a glass plate, comprising a step of arranging the interleaving paper for a glass plate according to any one of claims 1 to 9 between the glass plates.
A method for producing a glass sheet interleaving paper according to any one of claims 1 to 9,
A slurry preparation step for preparing a wood pulp slurry;
A sheet forming step for forming the slurry into a sheet;
A wet paper web preparation step for dehydrating the sheet to form a wet paper web;
Including at least a drying step of drying the wet paper to obtain the slip sheet;
A manufacturing method in which dehydration is performed from both sides of the sheet in the wet paper preparation step.
The manufacturing method according to claim 12, wherein the dehydration is performed by suction.
The manufacturing method according to claim 13, wherein a difference between the suction dewatering rate on one surface of the sheet and the suction dewatering rate on the other surface is 10% or less of the suction dewatering rate on the other surface. .
The manufacturing method according to claim 13 or 14, further comprising an additional suction step of sucking both surfaces of the interleaving paper after the drying step.