JP2018165419A - Wood pulp for glass sheet slip paper and use thereof, slip paper for glass sheet, and inspection method of wood pulp for glass sheet slip paper or slip paper for glass sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slip paper for a glass sheet used as a substrate material for a flat panel display which requires high cleanness and scratch property, capable of reducing contamination of the glass surface to substantially no-problem level, and a wood pulp for the slip paper.SOLUTION: The wood pulp for a glass sheet slip paper is characterized by that, when a slurry is prepared by the disintegration method of a plain paper sample according to JIS P 8120, followed by adding a coloring agent or a color former to the slurry and measuring the coloring slurry or the color forming slurry by using a flow cytometer, the number of a coloring foreign matter or a color forming foreign matter having a size of 0.1-50 μm is 30,000/μg or under; and, the glass sheet slip paper is characterized by that the number of the foreign matter is 15,000/μg or under.SELECTED DRAWING: None

Description

  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 wood pulp used in 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 used for such applications have already been proposed as slip sheets that can prevent breakage of the glass plate and scratches on 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 plywood using the prepared raw materials is disclosed.

  However, these slip sheets do not completely prevent contamination of the glass plate surface for flat panel displays. In some cases, the glass plate surface contamination for some reason increases the defect rate of the glass plate. There is a real situation.

  In particular, due to the recent increase in size and definition of flat panel displays, products exist even if there are minute foreign objects and scratches (including defects and disconnections caused by them) that have not been a problem in display images. As a result, it becomes out of specification and leads to a decrease in yield. This problem is increasing year by year, and from the viewpoint of profitability, a high yield is required in the manufacturing process of flat panel displays, etc., and how to prevent contamination of the glass plate surface used for flat panel displays. is important.

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

  The present invention can reduce the contamination of the glass surface to a practically no problem level for glass plates used as substrate materials for flat panel displays that require high cleanliness and scratch quality. An object of the present invention is to provide a slip sheet and wood pulp for the slip sheet.

  For example, it is known that when a 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, problems such as disconnection occur. 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.

  The cause of such contamination of the glass plate has been difficult to identify, but one of the causes is a very small and very small amount of particulate foreign matter transferred from the surface of the glass sheet interleaf to the surface of the glass plate. Is known.

  Therefore, it can be considered that the size and the number of particulate foreign substances existing on the surface of the glass sheet interleaf (hereinafter also referred to as “glass sheet interleaf”) are made constant or less. However, it has been found that it is sometimes difficult to reduce the contamination of the glass plate surface to a practically no problem level only by limiting the size and number of particulate foreign substances on the surface of the glass plate slip sheet. .

  Therefore, as a result of intensive studies, the present inventors need to pay attention not only to the surface of the glass plate interleaf, but also to the particulate foreign matter inside thereof, and to the inside of the glass plate interleaf as a finished product. Dispersion of fibers constituting the interleaf paper or the wood pulp by disassembling the glass board interleaving paper or disassembling the wood pulp that is the raw material of the glass board interleaving paper, instead of observing the particulate foreign substances present The present invention found that the contamination of the surface of the glass plate can be reduced to a practically no problem level by limiting the size and number of particles after observing the particulate foreign matter and then reducing the size and number of the particles. Was completed.

The first aspect of the present invention is a wood pulp for glass board interleaving paper,
A slurry is prepared by dispersing the wood pulp in accordance with the disaggregation method of the plain paper test piece according to JIS P 8120,
The number of colored foreign substances or colored foreign substances having a size of 0.1 μm to 50 μm when the colored slurry or colored slurry after adding a colorant or color former to the slurry is measured with a flow cytometer is 30,000 / μg or less. It is wood pulp for glass board interleaving paper.

The second aspect of the present invention is a glass sheet interleaf made of wood pulp,
A slurry is prepared by dispersing the slip sheet according to the disaggregation method of the plain paper test piece according to JIS P 8120,
The number of colored foreign substances or colored foreign substances having a size of 0.1 μm to 50 μm when the colored slurry or colored slurry after adding a colorant or color former to the slurry is measured with a flow cytometer is 15000 / μg or less. It is a slip sheet for glass plate.

  The colorant or color former is preferably hydrophobic.

  The color former is preferably a fluorescent color former.

  The fluorescent color former is preferably Nile Blue or Nile Red.

  The foreign matter preferably contains a hydrophobic substance. The hydrophobic substance is selected from the group consisting of silicone, pitch, resin, rubber, oil, and talc adsorbing hydrophobic foreign matter. The silicone is preferably silicone oil. The silicone oil is preferably dimethylpolysiloxane.

  The glass plate is preferably used for a display, and in particular, the display is preferably a TFT liquid crystal display or an organic EL display.

  In addition, the present invention provides a glass sheet interleaving paper containing the wood pulp of the first aspect of the present invention and / or the glass sheet interleaving sheet of the second aspect of the present invention, and lamination with a glass sheet. Also related to the body.

  Furthermore, the present invention also relates to the use of the wood pulp of the first aspect of the invention for the production of glass board interleaving paper, in particular the glass board interleaving paper of the second aspect of the invention.

  And this invention relates also to the protection method of the glass plate including the process of arrange | positioning the glass plate interleaving paper of the 2nd aspect of this invention between glass plates.

The third aspect of the present invention is:
A step of preparing a slurry by dispersing wood pulp for glass plate interleaving paper or glass sheet interleaving paper according to the disaggregation method of plain paper test pieces according to JIS P 8120;
Adding a colorant or color former to the slurry to obtain a color slurry or color slurry;
Measuring the colored or colored slurry with a flow cytometer and measuring the number of colored foreign matters or colored foreign matters having a size of 0.1 to 50 μm,
Including a step of selecting wood pulp for glass plate interleaving paper having a number of foreign matters of 30000 pieces / μg or less or glass sheet interleaving paper having a number of foreign matters of 15000 pieces / μg or less, or The present invention relates to a method for inspecting slip sheets for glass plates.

  The glass board interleaving paper comprising the wood pulp for glass board interleaving paper according to the present invention and the glass sheet interleaving paper according to the present invention effectively suppress the transfer that causes fine particulate foreign matter from the interleaving paper to the glass plate. Or can be avoided. In this way, by suppressing or avoiding the transfer that causes a problem of fine particulate foreign matters to the glass plate, it becomes possible to prevent the circuit breakage of the color film or the like in the manufacturing process of the TFT liquid crystal display or the like.

  In the present invention, rather than limiting the size and number of particulate foreign matter only on the surface of the glass board interleaving paper, dismantling the glass board interleaving paper or dismantling the wood pulp that is the raw material of the glass board interleaving paper, In the state of the dispersion of the fibers constituting the slip paper or the wood pulp, the size and number of particles are limited by observing the particulate foreign matter, which may cause problems when transferred to a glass plate. All fine particulate foreign matters can be controlled, and contamination of the glass plate surface derived from the particulate foreign matters can be reduced to a level at which there is no practical problem.

  Further, in the present invention, the particulate foreign matter contained in the wood pulp itself for glass board interleaving paper or the glass board interleaving paper prepared from the wood pulp is obtained by disassembling the wood pulp or the interleaving paper for glass board. By treating the resulting slurry with a colorant or color former, it can be easily identified as a colored foreign matter or colored foreign matter. By measuring the size and number of the foreign matter, it can be used for glass board interleaving paper. Wood pulp or glass sheet slip paper can be easily selected.

  Furthermore, in the present invention, since the colored foreign matters or the colored foreign matters are measured using a flow cytometer, the size and number of the foreign matters can be quickly measured for a large number of minute foreign matters. Therefore, the inspection method of the present invention can be easily performed at high speed.

  A slurry is prepared according to the disaggregation method of the plain paper test piece according to JIS P 8120, and the colored slurry or coloring slurry after adding the coloring agent or coloring agent to the slurry is 0.1 μm to 50 μm when measured with a flow cytometer. A slurry is prepared according to a method for disaggregating a glass sheet interleaf made from wood pulp for glass sheet interleaving paper, wherein the number of colored foreign matters or colored foreign matters is 30000 pieces / μg or less, and a plain paper test piece according to JIS P 8120 The number of colored foreign matters or colored foreign matters having a size of 0.1 μm to 50 μm when the colored slurry or color developing slurry after adding the colorant or color developing agent to the slurry is measured with a flow cytometer is 15000 / μg or less. The glass sheet interleaf can effectively suppress or avoid the transfer of particulate foreign matter to the glass sheet. Kill. Therefore, by using the above glass plate interleaving paper, it is possible to reduce the contamination of the surface of the glass plate to a level where there is no practical problem. Here, “μg” in the above “30000 pieces / μg” and the above “15000 pieces / μg” mean the solid contents of the pulp and the slip sheet in the slurry to be measured by the flow cytometer, respectively.

  In the present invention, the slurry concentration obtained by the disaggregation method of plain paper test pieces according to JIS P 8120 is preferably 1 g / 100 ml.

  The “size” in the present invention means a volume average (median) particle diameter. The volume average particle diameter can be measured, for example, by a laser diffraction scattering method. The size of the foreign matter in the present invention is 0.1 μm to 50 μm, preferably 0.1 μm to 40 μm. More preferably, it is 0.1 μm to 30 μm. When the foreign matter is non-spherical, the volume average particle diameter means the average (median) of the spherical volume equivalent diameter of the foreign matter.

The first aspect of the present invention is a wood pulp for glass board interleaving paper,
A slurry is prepared by dispersing the wood pulp in accordance with the disaggregation method of the plain paper test piece according to JIS P 8120,
The number of colored foreign matters or colored foreign matters having a size of 0.1 μm to 50 μm as measured with a flow cytometer after adding a colorant or color developing agent to the slurry is preferably 30,000 / μg or less, preferably Is 25,000 pieces / μg or less, more preferably 20000 pieces / μg or less.

  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. .

  In addition, in the range not impairing the performance of the present invention, for the papermaking fiber mainly composed of the above-described wood pulp, if necessary, an adhesive, an antifungal agent, various papermaking fillers, a wet paper strength enhancer, Add dry paper strength enhancer, sizing agent, colorant, fixing agent, yield improver, slime control agent, etc., then known and existing long net paper machine, circular net paper machine, short net paper machine, long net It can be obtained by paper making with a circular net combination paper machine. In addition, when adding these chemicals, extreme caution is required so that insects and dust do not enter.

  When the wood pulp of the present invention is produced, if the beating of the wood pulp is advanced, an effect of increasing the paper interlayer strength can be expected. However, if the fine fibers in the wood pulp increase as the beating progresses, paper dust may be generated during use as a slip sheet, so it is not preferable to advance the beating degree more than necessary. Therefore, a preferable beating degree in the present invention is 300 to 650 mlc. s. f. It is.

  The form of the wood pulp for glass plate interleaving paper of the present invention is not particularly limited, and can take any form of sheet, block or 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 “Paper Pulp Manufacturing Technology Series” published by the Paper Pulp Technology Association and “Paper Pulp Manufacturing Technology Full Text”. 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 pulp sheet is preferably 400~1300g / ^{m 2,} more preferably from 500~1200g / ^{m 2,} more preferably from 500~1100g / ^{m 2,} 500~1000g / M ² is more preferable, and 700 to 1000 g / m ² is even more preferable.

  By using the wood pulp of the present invention, glass plate interleaving paper, particularly the glass plate interleaving paper of the present invention, can be obtained by an ordinary method such as papermaking. In addition, you may perform processes, such as a calendar process, a super calendar process, a soft nip calendar process, and embossing, in the middle of papermaking of a glass board interleaving paper, and / or after papermaking. Surface properties and thickness can be adjusted by processing.

The second aspect of the present invention is a glass sheet interleaf made of wood pulp,
A slurry is prepared by dispersing the slip sheet according to the disaggregation method of the plain paper test piece according to JIS P 8120,
The number of colored foreign matters or colored foreign matters having a size of 0.1 μm to 50 μm as measured with a flow cytometer after adding a colorant or color developing agent to the slurry is preferably 15000 pieces / μg or less, preferably Is a slip sheet for glass plate, which is 10000 pieces / μg or less, more preferably 7000 pieces / μg or less.

  The thickness of the glass plate interleaving paper is preferably 0.01 to 0.4 mm, more preferably 0.05 to 0.2 mm, and even more preferably 0.06 to 0.1 mm. preferable.

The basis weight of the glass plate for inserting paper of the present invention is preferably 20 to 200 g / ^{m 2,} more preferably from 25~100g / ^{m 2,} still to be 30 to 80 g / ^{m 2} from preferable.

  The colorant or color former used in the first aspect and the second aspect of the present invention is not particularly limited as long as it can color or color foreign matter. Therefore, it is preferable that the cellulose fibers constituting the wood pulp or the interleaf paper are not colored or colored, or the degree of coloring or coloring is small. Since cellulose fibers are usually hydrophilic, the colorant or color former used in the present invention is preferably hydrophobic.

  The colorant is not particularly limited as long as it can color foreign matter in wood pulp or interleaf, and for example, dyes, pigments and mixtures thereof can be used.

  Any dye can be used. The dye is preferably hydrophobic and more preferably an oil-soluble dye.

  In the present invention, any hydrophobic dye can be used. Specific examples of the hydrophobic dye include C.I. I. Solvent Black, C.I. I. Solvent Yellow, C.I. I. Solvent Red, C.I. I. Solvent Violet, C.I. I. Solvent Blue, C.I. I. Solvent Green, and C.I. I. Solvent orange etc. are mentioned. C. I. Disperse Yellow, C.I. I. Disperse Orange, C.I. I. Disperse Red, C.I. I. Dispers Violet, C.I. I. Disperse Blue, C.I. I. Disperse dyes such as Disperse Green can also be used.

  Any pigment can be used. As the pigment, inorganic pigments, organic pigments, and mixtures thereof can be used. The pigment is preferably hydrophobic and more preferably lipophilic. Further, the pigment may be obtained by hydrophobizing the surface of a hydrophilic pigment.

  Examples of inorganic pigments include titanium oxide, zinc oxide, aluminum hydroxide, calcium carbonate, barium sulfate, silicon oxide, kaolin, clay, sericite, carbon black, oil smoke, bone black and the like.

  Examples of organic pigments include polystyrene particles, nylon powder, polyethylene powder, silicone resin filler, urea formalin resin filler, and the like whose surface is hydrophobic by a polymerization method or the like.

  The color former is not particularly limited as long as it has a property of developing color by stimulation such as electromagnetic wave irradiation and can develop a foreign substance in the slurry of wood pulp or interleaf. For example, it develops color by irradiation of electromagnetic waves. A color former, a color former that develops color upon contact with a chemical substance, or a mixture thereof can be used.

  Any color former can be used, but a fluorescent colorant that develops fluorescence upon irradiation with electromagnetic waves such as ultraviolet rays and infrared rays is preferred. As the fluorescent color former, for example, oxazine derivatives having an oxazine ring such as Nile Red and Nile Blue, and fluorescent dyes such as Oil Red O, Sudan III, and Sudan IV can be used.

  Further, the color former may be a fluorescent microsphere having a hydrophobic fluorescent substance in the fine particle or on the fine particle surface, or a quantum dot called nanocrystal. The surface of the quantum dot may be modified to be hydrophobic.

  The colorant or color former can be applied, for example, by applying a composition such as a solution or dispersion containing the colorant or color former to a slurry prepared from wood pulp or interleaving paper according to the disaggregation method for plain paper specimens according to JIS P 8120. It can carry out by adding. The concentration of the colorant or color former in the composition is not particularly limited, but is preferably 0.001 to 20% by weight, more preferably 0.01 to 10% by weight, and Even more preferred is 1-1 wt%.

  By the application, the colorant or color former is fixed on the surface of the particulate foreign matter contained in the slurry, and the foreign matter is colored to become a “colored foreign matter” or the foreign matter is colored. It becomes “colored foreign matter”. In the present invention, the particulate foreign matter present in the slurry can be identified as a colored foreign matter or a colored foreign matter. Therefore, in the present invention, the particulate foreign matter contained in the wood pulp for glass board interleaving paper, or contained in the paper for glass board interleaving, the presence or absence of colored or colored matter in the slurry, or coloring or coloring. Can be identified based on the shading.

  In the present invention, the foreign matter preferably contains a hydrophobic substance. The hydrophobic substance is colored or colored by a hydrophobic colorant or color former. Therefore, when a hydrophobic colorant or color former is used, it is contained in the particulate foreign matter contained in the slurry, preferably the particulate foreign matter. A colorant or color former selectively adheres to or dissolves in at least a hydrophobic substance present on the surface, and foreign matters having the hydrophobic substance are colored or colored. It is particularly preferable that the foreign material is composed only of a hydrophobic substance.

  The hydrophobic substance is not particularly limited as long as it has an affinity for a colorant or a color former. The hydrophobic substance is preferably non-volatile, and oils (excluding silicone oils. For example, aliphatic hydrocarbons, vegetable oils, animal oils, synthetic glycerides, fatty alcohols, fatty acids, fatty alcohols and / or esters of fatty acids). More preferably selected from the group consisting of resin (excluding silicone), silicone, pitch, rubber, and talc adsorbing hydrophobic foreign matter, especially from the group consisting of talc adsorbing silicone and hydrophobic foreign matter Even more preferably, it is selected.

  Aliphatic hydrocarbons include, for example, linear or branched hydrocarbons, especially mineral oil (liquid paraffin, etc.), paraffin, petrolatum, ie petrolatum, naphthalene, etc .; hydrogenated polyisobutene, isoeicosane, polydecene, pearl reamer, etc. And polyisobutenes and decene / butene copolymers; and mixtures thereof.

As examples of other aliphatic hydrocarbons, mention may also be made of linear, branched or optionally cyclic C ₆ -C ₁₆ lower alkanes. Examples that may be mentioned include hexane, undecane, dodecane, tridecane and isoparaffins such as isohexadecane and isodecane.

  Examples of vegetable oils include, for example, linseed oil, camellia oil, macadamia nut oil, sunflower oil, apricot oil, soybean oil, arara oil, hazelnut oil, corn oil, olive oil, avocado oil, sasanqua oil, castor oil, safflower Mention may be made of oil, jojoba oil, almond oil, grape seed oil, sesame oil, peanut oil, and mixtures thereof.

  Examples of animal oils include, for example, mink oil, squalene, perhydrosqualene and squalane.

  Examples of synthetic glycerides include caprylic / capric triglycerides.

  Fatty acids should be in acidic form (ie not in salt form to avoid soaping) and may be saturated or unsaturated and have 6 to 30 carbon atoms, especially 9 to 30 carbons. Contains atoms and is optionally substituted, in particular with one or more hydroxyl groups (especially 1 to 4). When the fatty acid is unsaturated, the compound can contain 1 to 3 conjugated or non-conjugated carbon-carbon double bonds. The fatty acid is selected from, for example, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid, linolenic acid and isostearic acid.

The term “aliphatic alcohol” as used herein means any saturated, linear or branched C ₈ -C ₃₀ alcohol, optionally, especially one or more hydroxyl groups ( In particular, 1 to 4) are substituted.

Among the aliphatic alcohols, C _{12 to} C ₂₂ aliphatic alcohols are preferable, and C _{16 to} C ₁₈ saturated aliphatic alcohols are more preferable. Among these, lauryl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, behenyl alcohol, undecyl alcohol, myristyl alcohol, and mixtures thereof can be mentioned.

Examples of esters of fatty acids and / or fatty alcohols are saturated or unsaturated, linear or branched C ₁ -C ₂₆ aliphatic mono- or polyacid esters, and saturated or unsaturated, linear Jo or branched C ₁ -C ₂₆ monohydric alcohol or polyhydric alcohol esters of aliphatic can particularly mention, the total number of carbon atoms in the ester is preferably 10 or more.

  The resin (excluding silicone) is not particularly limited as long as it is hydrophobic. Examples of the resin include thermoplastic resins such as polyolefin, polystyrene, poly (meth) acrylate, polyacrylamide, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyester, polycarbonate, polyamide, polyimide, polyurethane, melamine resin, and urea resin. And the like, and a mixture thereof.

Silicone includes silicone oil. 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 silicone oils include linear organopolysiloxanes, cyclic organopolysiloxanes, and branched organopolysiloxanes.

Ｒ^１ _{（４−ｃ）}Ｓｉ（ＯＳｉＲ^１ _３）_ｃ （３）

（式中、
Ｒ^１は、それぞれ独立して、水素原子、水酸基、或いは、置換若しくは非置換の一価炭化水素基、アルコキシ基で示される基から選択される基であり、
ａは、０〜１０００の整数であり、
ｂは３〜１００の整数であり、
ｃは１〜４の整数、好ましくは２〜４の整数である）
で表されるオルガノポリシロキサンが挙げられる。 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.

  A 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. Valent saturated hydrocarbon group; 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; carbon atom A monovalent aromatic hydrocarbon group having a number of 6 to 30, 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 a vinyl group, 1-propenyl group, allyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, pentenyl group, and hexenyl group. 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 , 3-isocyanatopropyl group and the like.

  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 dimethylsilicone 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 , Trimethylsiloxy group-blocked dimethylsiloxane / diphenylsiloxane copolymer, both ends of molecular chain, trimethylpentaphenyltrisiloxane, phenyl (trimethylsiloxy) siloxane, trimethylsiloxy group-blocked methyl at both ends of molecular chain Alkylpolysiloxane, trimethylsiloxy group-capped dimethylpolysiloxane / methylalkylsiloxane copolymer with both ends of molecular chain, dimethylsiloxane / methyl (3,3,3-trifluoropropyl) siloxane copolymer with trimethylsiloxy group-capped dimethylsiloxane , 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, tetrakis Trimethylsiloxysilane, tetramethyl-1,3 Examples include dihydroxydisiloxane, octamethyl-1,7-dihydroxytetrasiloxane, hexamethyl-1,5-diethoxytrisiloxane, hexamethyldisiloxane, octamethyltrisiloxane, higher alkoxy-modified silicone, higher fatty acid-modified silicone, and dimethiconol. The

  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-methacryloxypro L) 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 Black tetra siloxane 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 in which a polyoxyalkylene group is 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 each 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 and 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, and specifically 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, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group; a vinylene group, an arylene group, a 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, , 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, preferably an alkylene group having 1 to 6 carbon atoms, and more preferably an alkylene group having 3 to 5 carbon atoms.

（式中、
ｘは２０〜１６０であり、ｙは１〜２５であり、ｘ／ｙの値は５０〜２であり、
Ａは、例えば−（ＣＨ_２）_３Ｏ−（ＣＨ_２ＣＨ_２Ｏ）_ｍ−（ＣＨ_２ＣＨ_２ＣＨ_２Ｏ）_ｎ−Ｒ^４であり、ｍは７〜４０、ｎは０〜４０、ｍ＋ｎの値は少なくとも１であり、グラフト重合されたものでもランダム重合されたものでもよく、Ｒ^４は水素原子又は上記置換若しくは非置換の一価炭化水素基を表す。好適には、ｍは７〜３０、ｎは０〜３０である） 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)

  Examples of the modified silicone oil include aminoalkyl-modified silicone oil.

  The aminoalkyl-modified silicone oil is a silicone oil having an aminoalkyl group 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).

  In the present invention, when the foreign substance is silicone, the amount of silicone contained in the wood pulp or glass board interleaf is preferably 0.5 ppm or less with respect to the absolute dry mass of the wood pulp or interleaf. It is more preferably 4 ppm or less, still more preferably 0.3 ppm or less, still more preferably 0.2 ppm or less, and particularly preferably 0.1 ppm or less. When there is more than 0.5ppm of silicone, color film breaks caused by a small amount of silicone transferred to the glass in high-definition scenes such as mobile devices that require a very high-definition display are highly detailed. This is because there is an increased risk of being conspicuous and being judged as a quality defect. In the present invention, “absolutely dry” means a state in which moisture is not substantially present in an object to be dried by drying. For example, at the room temperature (25 ° C.) of an object in an “absolutely dry” state. The weight change per hour is 1% or less, preferably 0.5% or less, more preferably 0.1% or less.

  In general, wood pulp often contains silicone. This is because a silicone-based antifoaming agent is frequently used as a defoaming agent used to prevent a decrease in cleaning ability due to foam generation in the wood pulp manufacturing process, particularly in the cleaning process. The derived silicone remains in the pulp. 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.

Talc is an inorganic powder obtained by pulverizing talc, and is a hydrous magnesium silicate having a general structure: Mg ₃ (SiO ₂ ) ₂ (OH) ₂ or Mg ₃ Si ₄ O ₁₀ (OH) ₂ having a layered structure. Talc is used as a filler, pitch control agent, or coating agent, and may be contained in wood pulp.

  Accordingly, the amount of hydrophobic foreign matter contained in the wood pulp or glass board interleaf of the present invention is determined by the colorant or colorant in the slurry obtained by dispersing the wood pulp by the disaggregation method of plain paper test pieces according to JIS P 8120. To the extent that the number of colored foreign matters or colored foreign matters having a size of 0.1 μm to 50 μm when measured with a flow cytometer is 30000 / μg or less, and according to JIS P 8120 Size of 0.1 μm to 50 μm when the colored slurry or color developing slurry is measured with a flow cytometer after adding the colorant or color developing agent to the slurry obtained by dispersing the slip sheet by the disaggregation method of the plain paper test piece The number of colored foreign matters or colored foreign matters is preferably 15000 / μg or less and is reduced to some extent. Arbitrariness.

  In particular, 0.1 μm or more selected from the group consisting of talc adsorbing silicone, pitch, resin, rubber, oil (excluding silicone oil) and hydrophobic foreign matters contained in the wood pulp or glass board interleaf of the present invention When the amount of the hydrophobic substance having a size of 50 μm is measured with a flow cytometer in a slurry obtained by dispersing the wood pulp or glass board interleaving paper by the disaggregation method of the plain paper test piece according to JIS P 8120 It is more preferable that the amount is reduced to a rate of 30000 pieces / μg or less (in the case of a wood pulp slurry) or 15000 pieces / μg or less (in the case of a slip slurry).

  The means for reducing the content of the foreign matter which is a problem contained in the wood pulp or glass board interleaf of the present invention is not particularly limited, but non-silicone is used as an antifoaming agent used in the production of wood pulp or interleaf. It is preferable to use a system antifoaming agent and to use a filler other than talc as a filler.

  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.

  The higher alcohol antifoaming agent includes, 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 monoricinolate, 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 type antifoaming agent includes, for example, aluminum stearate, calcium stearate, potassium oleate and the like.

  The sulfonate ester antifoaming agent includes, for example, 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-hex Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylene alcohols such as 2-methyl-2-butanol 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 Stearylphosphate esters of (poly) oxyalkylene alkyl phosphoric acid esters; polyoxyethylene such as polyoxyethylene lauryl amine (poly) oxyalkylene alkyl amines; containing polyoxyalkylene amide.

  The vegetable oil-based antifoaming agent includes, 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.

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

  As fillers other than talc, inorganic fillers such as kaolin, calcium carbonate, titanium oxide, and barium sulfate, and organic fillers such as urea resin can be used.

  The wood pulp for glass board interleaving paper of the present invention is a colored slurry or color developing slurry after adding a colorant or color developing agent to a slurry obtained by dispersing the wood pulp by the disaggregation method of plain paper test pieces according to JIS P 8120. The number of colored foreign matters or colored foreign matters having a size of 0.1 μm to 50 μm when measured with a flow cytometer is 30000 / μg or less. Therefore, the wood pulp for glass board plywood according to the present invention is intended to be before being slurried.

  Similarly, the interleaving paper for glass plate of the present invention is a colored slurry or coloring slurry after adding a coloring agent or a coloring agent to a slurry obtained by dispersing the interleaving paper by the disaggregation method of the plain paper test piece according to JIS P 8120. The number of colored foreign substances or colored foreign substances having a size of 0.1 μm to 50 μm when measured with a flow cytometer is 15000 / μg or less. Therefore, the interleaving paper for a glass plate of the present invention is intended before being slurried.

  The interleaving paper obtained from the wood pulp of the present invention, particularly the glass plate interleaving paper of the present invention, is used by being inserted between the glass plates. 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 paper which consists of the wood pulp of this invention, especially the glass plate slip paper 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 glass plate interleaf made of the wood pulp of the present invention, particularly the glass plate interleaf of the present invention. Since transfer of fine foreign matters such as silicone and other hydrophobic substances to the glass plate is suppressed or avoided, even if fine electrodes, partition walls, etc. are formed on the surface of the glass plate, there is no problem due to the foreign matter. As a result, display defects can be suppressed or avoided.

  In particular, as the size of the display increases, the size and weight of the glass plate for flat panel displays has increased, but the glass plate interleaf made of the wood pulp of the present invention, particularly the glass plate interleaf of the present invention, The surface of such a large or heavy glass plate can be well protected. In particular, the glass plate interleaf made of the wood pulp of the present invention, in particular the glass plate interleaf of the present invention, is a foreign material having a size of 0.1 μm to 50 μm, particularly silicone, pitch, resin, rubber, oil (excluding silicone). In addition, since the content of hydrophobic foreign matter such as talc adsorbing hydrophobic foreign matter is extremely small, transfer of the foreign matter to the glass plate is suppressed or avoided even when pressed by a heavy glass plate. Therefore, the glass plate interleaf made of the wood pulp of the present invention, particularly the glass plate interleaf of the present invention, can be suitably used for a glass plate for a flat panel display in which surface cleanliness is particularly required.

The present invention also relates to a method for inspecting wood pulp for glass plate interleaving paper or glass sheet interleaving paper. The inspection method of the wood pulp for glass board interleaving paper or the glass sheet interleaving paper of the present invention,
A step of preparing a slurry by dispersing wood pulp for glass plate interleaving paper or glass sheet interleaving paper according to the disaggregation method of plain paper test pieces according to JIS P 8120;
Adding a colorant or color former to the slurry to obtain a color slurry or color slurry;
Measuring the colored or colored slurry with a flow cytometer and measuring the number of colored foreign matters or colored foreign matters having a size of 0.1 to 50 μm,
Including a step of selecting wood pulp for glass plate interleaving paper having the number of foreign matters of 30000 pieces / μg or less or glass sheet interleaving paper having the number of foreign matters of 15000 pieces / μg or less.

  In the step of preparing slurry by dispersing wood pulp for glass plate interleaving paper or glass sheet interleaving paper according to the disaggregation method of plain paper test pieces according to JIS P 8120, the slurry concentration is preferably 1 g / 100 ml.

  The “size” in the present invention means a volume average (median) particle diameter. The volume average particle diameter can be measured, for example, by a laser diffraction scattering method. The size of the foreign matter in the present invention is 0.1 μm to 50 μm, preferably 0.1 μm to 40 μm. More preferably, it is 0.1 μm to 30 μm.

  The step of obtaining a colored slurry or color developing slurry by adding a colorant or color developing agent to the slurry may be carried out, for example, by adding a composition such as a solution or dispersion containing the colorant or color developing agent to the slurry. it can. The concentration of the colorant or color former in the composition is not particularly limited, but is preferably 0.001 to 20% by weight, more preferably 0.01 to 10% by weight, and Even more preferred is 1-1 wt%.

  The step of measuring the colored or colored slurry with a flow cytometer and measuring the number of colored foreign matters or colored foreign matters having a size of 0.1 μm to 50 μm can be performed using a flow cytometer.

  A flow cytometer is a device that performs flow cytometry. Specifically, flow cytometry uses a suspension of an object to be measured as a high-speed fluid, especially water flow, and measures scattered light and fluorescence generated by irradiating the fluid with laser light, mercury light, etc. -It is a method of measuring the size, amount, etc. of the measurement object with high accuracy and sorting the particles of the measurement object by quantifying. The measurement object is introduced into a very fine tube (flow cell), and the irradiation is performed while the measurement object is flowing through the tube in an aligned state.

  The flow cytometer according to the present invention irradiates foreign matter with excitation light, and measures the size of the foreign matter by measuring reflected light and / or scattered light from the foreign matter and / or fluorescence from the excited state of the foreign matter. The number etc. can be measured automatically. Since the flow cytometer is widely used particularly in the biotechnology field, and the device itself is also commercially available, the measurement using the flow cytometer in the present invention does not involve any difficulty. Examples of the flow cytometer that can be used in the present invention include CyFlow Cube 6 manufactured by Sysmex Corporation.

  The flow rate of the slurry, which is an object to be measured by the flow cytometer in the present invention, is preferably 1000 pieces / second.

  The flow cytometer can quickly measure the size and the number of foreign matters for a large number of minute foreign matters. Therefore, the inspection method of the present invention can be easily performed at high speed.

  In addition, before implementing the said process, in order to remove a huge foreign material beforehand, you may filter a slurry suitably.

  The step of selecting the wood pulp for glass plate interleaving paper having the number of foreign matters of 30000 pieces / μg or less or the glass sheet interleaving paper having the number of foreign matters of 15000 pieces / μg or less is, for example, a preset 30000 pieces / According to a standard of not more than μg or not more than 15000 pieces / μg, it can be carried out by manually or automatically selecting glass pulp interleaving wood pulp or glass sheet interleaving paper that meets the standard.

  Specifically, for example, when the above-mentioned application / measurement / decision process is performed on a part of wood pulp of the same lot or the paper obtained from the wood pulp, and the wood pulp or the paper meets the above criteria In addition, it can be considered acceptable for all of the wood pulp or the slip sheet to satisfy the standard.

  Since the inspection method of the present invention can use a flow cytometer, it can be easily performed at a high speed.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely using an Example and a comparative example, the scope of the present invention is not limited to an Example.

[Example 1] (Production of wood pulp)
In a conifer bleached kraft pulp manufacturing apparatus consisting of a cooking process, a washing process, an oxygen delignification reaction process, and a multistage bleaching bleaching process with chlorine dioxide and hydrogen peroxide, An appropriate amount of a stock solution of a 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 A which used the non-silicone type | system | group antifoamer in the manufacturing process was obtained. The form of this softwood bleached kraft pulp A was made into a sheet-like pulp having a thickness of 1.2 mm and a basis weight of 700 g / m ² according to a conventional method.
This softwood bleached kraft pulp A is dispersed according to the disaggregation method of plain paper test pieces according to JIS P 8120 to prepare a slurry having a concentration of 1 g / 100 ml. When the colored slurry after the addition of 20 ppm was measured with a flow cytometer (CyFlow Cube 6 manufactured by Sysmex Corporation), the number of colored foreign matters having a size of 0.1 μm to 50 μm was 26000 / μg.

[Comparative Example 1] (Manufacture of wood pulp)
Softwood bleached kraft pulp B was obtained in the same manner as in Example 1 except that the solvent was not washed. The form of this softwood bleached kraft pulp B was made into a sheet-like pulp having a thickness of 1.2 mm and a basis weight of 700 g / m ² according to a conventional method.
This softwood bleached kraft pulp A is dispersed according to the disaggregation method of plain paper test pieces according to JIS P 8120 to prepare a slurry having a concentration of 1 g / 100 ml. When the colored slurry after the addition of 20 ppm was measured with a flow cytometer (CyFlow Cube 6 manufactured by Sysmex Corporation), the number of colored foreign matters having a size of 0.1 μm to 50 μm was 38000 / μg.

[Example 2] (Production of glass plate interleaving paper)
As a wood pulp, 100 parts by mass of the kraft pulp A of the conifer of Example 1 was prepared, and this was disaggregated to give a beating degree of 520 mlc. s. f. 0.5 parts by weight of polyacrylamide (trade name: Polystron 1250, manufactured by Arakawa Chemical Industries, Ltd.) as a paper strength enhancer was added to the slurry prepared in the above, and a pulp slurry having a concentration of 0.4% was added. Prepared. From this, a glass sheet interleaf having a basis weight of 50 g / m ² and a thickness of 0.093 mm was obtained using a long web paper machine.
This glass board interleaving paper is dispersed according to the disaggregation method of plain paper test pieces according to JIS P 8120 to prepare a slurry having a concentration of 1 g / 100 ml. When the colored slurry after the addition was measured with a flow cytometer (CyFlow Cube 6 manufactured by Sysmex Corporation), the number of colored foreign matters having a size of 0.1 μm to 50 μm was 12000 / μg.

[Comparative Example 2] (Production of glass plate interleaving paper)
A glass sheet plywood having a basis weight of 50 g / m ² was obtained in the same manner as in Example 2 except that 100 parts by mass of the softwood bleached kraft pulp B of Comparative Example 1 was used as the wood pulp.
This glass board interleaving paper is dispersed according to the disaggregation method of plain paper test pieces according to JIS P 8120 to prepare a slurry having a concentration of 1 g / 100 ml. When the colored slurry after the addition was measured with a flow cytometer (CyFlow Cube 6 manufactured by Sysmex Corporation), the number of colored foreign matters having a size of 0.1 μm to 50 μm was 19000 / μg.

  When the transfer of the glass plate interleaving paper obtained in Example 2 and Comparative Example 2 to the glass plate was confirmed by a transportation test, an array of a liquid crystal panel using the glass plate using the interleaving paper of Example 2 was formed. No disconnection of the color film was observed. On the other hand, when forming an array of a liquid crystal panel using a glass plate using the interleaving paper of Comparative Example 2, disconnection of the color film was observed.

Claims (19)

Wood pulp for glass board interleaving paper,
A slurry is prepared by dispersing the wood pulp in accordance with the disaggregation method of the plain paper test piece according to JIS P 8120,
The number of colored foreign substances or colored foreign substances having a size of 0.1 μm to 50 μm when the colored slurry or colored slurry after adding a colorant or color former to the slurry is measured with a flow cytometer is 30,000 / μg or less. Wood pulp for glass board interleaving paper.   The wood pulp for glass board interleaving paper according to claim 1, wherein the colorant or color former is hydrophobic.   The wood pulp for glass board interleaving paper according to claim 1 or 2, wherein the color former is a fluorescent color former.   The wood pulp for glass board plywood according to claim 3, wherein the fluorescent color former is Nile Blue or Nile Red.   The wood pulp for glass board interleaving paper as described in any one of Claim 1 to 4 in which the said foreign material contains a hydrophobic substance.   The wood pulp for glass board plywood according to claim 5, wherein the hydrophobic substance is selected from the group consisting of talc adsorbing silicone, pitch, resin, rubber, oil and hydrophobic foreign matter.   The wood pulp for glass plate interleaving paper according to any one of claims 1 to 6, wherein the glass plate is for display, preferably for TFT liquid crystal display or for organic EL display.   A glass sheet interleaf comprising the wood pulp for glass sheet interleaving paper according to any one of claims 1 to 7.   Use of the wood pulp according to any one of claims 1 to 7 for the production of glass board interleaving paper. It is a slip sheet for glass plate made from wood pulp,
A slurry is prepared by dispersing the slip sheet according to the disaggregation method of the plain paper test piece according to JIS P 8120,
The number of colored foreign substances or colored foreign substances having a size of 0.1 μm to 50 μm when the colored slurry or colored slurry after adding a colorant or color former to the slurry is measured with a flow cytometer is 15000 / μg or less. Interleaving paper for glass plate.   The slip sheet for glass plates according to claim 10, wherein the colorant or color former is hydrophobic.   The slip sheet for glass plates according to claim 10 or 11, wherein the color former is a fluorescent color former.   The slip sheet for glass plates according to claim 12, wherein the fluorescent color former is Nile Blue or Nile Red.   The slip sheet for glass plates according to any one of claims 10 to 13, wherein the foreign matter contains a hydrophobic substance.   The slip sheet for glass plates according to claim 14, wherein the hydrophobic substance is selected from the group consisting of talc adsorbing silicone, pitch, resin, rubber, oil, and hydrophobic foreign matters.   The interleaf paper for a glass plate according to any one of claims 10 to 15, wherein the glass plate is for a display, preferably for a TFT liquid crystal display or an organic EL display.   The laminated body which consists of the paper for glass plates as described in any one of Claims 10-16, and a glass plate.   The protection method of a glass plate including the process of arrange | positioning the paper for glass plates as described in any one of Claims 10-16 between glass plates. A step of preparing a slurry by dispersing wood pulp for glass plate interleaving paper or glass sheet interleaving paper according to the disaggregation method of plain paper test pieces according to JIS P 8120;
Adding a colorant or color former to the slurry to obtain a color slurry or color slurry;
Measuring the number of colored foreign matters or colored foreign matters having a size of 0.1 to 50 μm by measuring the colored or colored slurry with a flow cytometer,
Including a step of selecting wood pulp for glass plate interleaving paper having a number of foreign matters of 30000 pieces / μg or less or glass sheet interleaving paper having a number of foreign matters of 15000 pieces / μg or less, or Inspection method for slip sheets for glass plates.