JP7283517B2 - Glass interleaving paper, method for producing glass interleaving paper, and glass plate laminate - Google Patents

Description

The present invention relates to a glass interleaving paper, a method for producing a glass interleaving paper, and a glass plate laminate.

Glass plates for FPD (Flat Panel Display) such as glass plates for buildings, glass plates for automobiles, glass plates for plasma displays, and glass plates for liquid crystal displays are subject to surface scratches during storage and transportation. Product defects may occur, for example, due to contamination by contaminants in the atmosphere.

In particular, a glass plate (glass substrate) for FPD has fine electrical wiring (hereinafter also referred to as wiring), electrodes, electrical circuits, barrier ribs, and other elements formed on the surface, so slight scratches and contamination may occur on the surface. Even if there is, it may cause defects such as disconnection. Therefore, glass plates used for these applications are required to have a high surface cleanliness.

At this time, by interposing so-called glass interleaving paper between the glass plates as shown in FIG. there is

However, in the method of interposing the glass interleaving paper between the glass plates, the glass interleaving paper and the surface of the glass plate are in direct contact. Therefore, various components (foreign substances) such as resin existing on the surface of the glass interleaving paper are transferred to the surface of the glass plate. When a glass interleaving paper having a large amount of foreign matter on its surface is used, problems such as paper texture patterns, burns, stains, and the like tend to occur on the glass plate. Moreover, it causes defects such as disconnection of fine wiring formed on the surface of the glass plate.

As a method for solving the above problem, for example, Patent Document 1 discloses an interleaving paper that satisfies the condition that the content density of adhesive pitch contaminants is 0.07 pieces/m ² or less.

JP 2008-143542 A

However, as a result of investigation by the present inventors, it was found that simply reducing the content density of the adhesive pitch foreign matter in the glass interleaving paper may not sufficiently suppress the occurrence of defects such as disconnection of the wiring formed on the surface of the glass plate. It turns out there is.

In addition, according to the said patent document 1, the adhesive pitch foreign material means the foreign material which has the adhesiveness which is dispersed in the interleaving paper and which is not completely solidified.

The present invention has been made in view of this background, glass interleaving paper that can sufficiently suppress the occurrence of defects such as contamination and wiring caused by foreign substances transferred from the glass interleaving paper to the surface of the glass plate, It is to provide the manufacturing method of this glass interleaving paper, and the glass plate laminated body using this glass interleaving paper.

In order to achieve the above object, the present invention provides a glass interleaving paper interposed between the glass plates when laminating a plurality of glass plates, wherein the glass interleaving paper is crimped on the surface of the glass plate Provided is a glass interleaving paper characterized by having a density of 50 particles/m ² or less of immovable foreign matters having a major axis of 10 μm or more.

According to the glass interleaving paper according to the present invention, it is possible to sufficiently suppress the occurrence of contamination caused by foreign matter transferred from the glass interleaving paper to the surface of the glass plate, and defects such as wiring.

FIG. 1 is a cross-sectional view of a glass plate laminate in which glass interleaving paper and glass plates are alternately laminated and laid flat. FIGS. 2A and 2B are explanatory diagrams showing the state of the evaluation glass plate passing through the cleaning apparatus. FIG. 3 is a schematic configuration diagram of a paper machine for making glass interleaving paper. FIG. 4 is a diagram showing the value of the vector length of the Hansen solubility parameter of each additive and the interaction distance Ra of the Hansen solubility parameter for water (HSP vector distance Ra). FIGS. 5A and 5B are diagrams showing images of an immovable foreign object.

One embodiment of the present invention will be described below with reference to the drawings as necessary. In addition, the present invention is not limited to the following embodiments.

As described above, in order to suppress defects such as contamination of the surface of the glass plate and disconnection of wiring formed on the surface of the glass plate by transferring foreign matter from the glass interleaving paper to the glass plate, glass interleaving paper has been conventionally used. Attempts have been made to reduce the content of contaminants therein.
On the other hand, in recent years, the spatial resolution of FPDs has become higher, and as a result, wirings, electrodes, etc. formed on glass plates have become finer. For example, in the case of wiring, wiring with a width of about 3 to 5 μm is required to be formed at intervals (pitch) of about 50 to 200 μm.

However, according to the study of the present inventors, when forming such fine wiring, even if there is a slight amount of foreign matter on the surface of the glass plate, the metal thin film (metallic compound thin film) that becomes the wiring can be formed. It becomes a hindrance factor for film formation, patterning by etching, etc., and extremely strict high cleanliness is required.
Furthermore, in the case of glass plates for FPDs, etc., the size of the glass interleaving paper is required to be increased in accordance with the recent increase in size of the display, and the above-mentioned high cleanliness is required.

According to the study of the present inventor, in order to increase the size of the glass interleaving paper, in order to optimize various physical properties of the glass interleaving paper such as strength, density, smoothness, etc. Addition of additives may be effective. However, depending on the type of additive used, it may be difficult to highly clean the glass interleaving paper.

In addition, in the case of large-sized glass interleaving paper, foreign matter must be contained within a large area within a permissible value, so compared to small-sized glass interleaving paper, the non-defective product rate tends to decrease. Therefore, attention must be paid to the members used in manufacturing the glass interleaving paper. This is to prevent substances or the like detached from the surfaces of members in the manufacturing process from being added as unintended additives. For example, selection of appropriate materials for members that come into contact with pulp, pulp slurry, and glass interleaving paper, and cleaning of manufacturing equipment and members are included.

That is, due to the use of additives and the influence of the materials used in the manufacture of the glass interleaving paper, immovable foreign matter that does not change its position on the glass plate even after washing may be present on the surface of the glass plate. there were.

Therefore, as a result of further investigation by the present inventor, the number of immovable foreign substances present on the surface of the glass plate in contact with the glass interleaving paper is reduced by specifying the types of additives used in the glass interleaving paper and the members used for manufacturing. As a result, the inventors have found that defects such as disconnection of wiring can be suppressed, and have completed the present invention.

In addition, the invention which concerns on this embodiment is not what is premised on a large sized glass interleaving paper, but is that it is used suitably in the case of a large sized glass interleaving paper. In the present specification, "large glass interleaving paper" is not particularly limited, but has a short side of 730 mm or more, for example. The invention according to this embodiment preferably has a short side of 1000 mm or more, more preferably 1200 mm or more, still more preferably 1500 mm or more, still more preferably 1800 mm or more, even more preferably 2000 mm or more, and even more preferably 2200 mm. As described above, it is particularly preferably used for glass interleaving paper having a thickness of 2500 mm or more.

In this specification, the term "additives" includes not only additives such as chemicals for papermaking, but also those detached and added from the surfaces of members in the manufacturing process.

The glass interleaving paper according to the present embodiment is a glass interleaving paper interposed between the glass plates when laminating a plurality of glass plates, and when the glass interleaving paper is crimped to the surface of the glass plate, the glass The density of immovable foreign matter having a major diameter of 10 μm or more generated (transferred) on the surface of the plate is 50 particles/m ² or less. This can sufficiently suppress the occurrence of contamination caused by foreign matter transferred from the glass interleaving paper and defects in wiring and the like.
Moreover, the glass plate laminated body which concerns on this embodiment has the glass interleaving paper interposed between the glass plates of several sheets.

The glass interleaving paper preferably has a thickness of 0.1 mm or less. This is preferable from the point of view of physical distribution because more length of glass interleaving paper can be obtained with one glass interleaving paper roll. In addition, when more glass plates and glass interleaving papers are alternately laminated to form a glass plate package, more glass plates can be laminated on the pallet, which is preferable. The thickness of the glass interleaving paper is more preferably 0.09 mm or less, still more preferably 0.08 mm or less, still more preferably 0.07 mm or less.
Although the lower limit of the thickness of the glass interleaving paper is not particularly limited, it is, for example, 0.01 mm or more.

When the glass interleaving paper has a rectangular shape, it is preferable that the short side is 730 mm or more. This allows it to be inserted between the larger size glass plates that are in demand in recent years. It is more preferably 100 mm or more, still more preferably 1500 mm or more, and even more preferably 2000 mm or more. Moreover, although the upper limit of the short side of glass interleaving paper is not specifically limited, it is 4000 mm or less, for example.

In addition, when the thickness of the glass interleaving paper is 0.1 mm or less and / or the short side is 730 mm or more, in the process of laminating the glass plate and the glass interleaving paper, etc., the strength and density of the glass interleaving paper are higher, smoothness, water resistance properties, moisture resistance, etc. are required. Therefore, more or new additives not used conventionally may be added, and one embodiment of the present invention is preferably used.

Glass interleaving paper used in the present embodiment includes chemical pulp such as kraft pulp (KP), sulfite pulp (SP), soda pulp (AP); semi-chemical pulp (SCP), chemi-grand wood pulp (CGP). semi-chemical pulp such as; mechanical pulp such as ground wood pulp (GP), thermomechanical pulp (TMP, BCTMP), refiner groundwood pulp (RGP); non-wood fiber pulp made from kozo, mitsumata, hemp, kenaf, etc.; Glass interleaving paper containing various raw materials such as synthetic pulp can be used. Further, the glass interleaving paper of the present invention may be made from a mixture of these materials, or may be made from a material containing cellulose or the like.

Moreover, these raw materials may be waste paper, virgin pulp, or a mixture of waste paper and virgin pulp. Among them, virgin pulp is preferred.

In the glass interleaving paper of the present embodiment, no matter which pulp is used, silicone-based antifoaming agents (silicone-containing antifoaming agents) are a major cause of defects in wiring and electrodes when transferred to a glass plate. It is preferable to use as a raw material pulp produced without using any agent).

In particular, pulp produced without using an antifoaming agent containing polydimethylsiloxane is particularly suitably used as a raw material for the glass interleaving paper of the present embodiment.

Next, immovable foreign matter on the surfaces of the glass plates laminated via the glass interleaving paper according to one embodiment of the present invention will be described. Immovable foreign matter is often made of artificial synthetic resin, and is often solid at room temperature.

First, one evaluation glass plate (thickness: 0.5 mm, 470 mm x 370 mm) is prepared (step A). Examples of the glass plate for evaluation include glass plates for FPDs such as liquid crystal displays (LCD), plasma display panels (PDP), and organic electroluminescence (EL) displays, but are not limited thereto. Planar glass panes may also be mentioned, including plates, vehicle glass panes, and the like. It may also be a curved glass plate.

Next, the glass plate for evaluation is inspected using a foreign substance inspection machine (HS730 manufactured by Toray Industries, Inc.) to obtain a first image of all foreign substances (step B). The first foreign matter that can be recognized in the first image is not derived from the glass interleaving paper, but is a foreign matter such as a fine scratch originally included in the evaluation glass plate. Therefore, the first foreign matter is excluded when defining an immovable foreign matter, which will be described later. Moreover, the above inspection is performed using a mode called a 1 μm mode, which detects a foreign matter of 1 μm or more with standard particles.

Next, a glass interleaving paper is laminated on the glass plate for evaluation, and a weight of 50 kg is further loaded thereon to form a laminate (step C). Thereby, the glass interleaving paper is brought into contact with and pressed against the evaluation glass plate. The load of 50 kg corresponds to the weight of 200 glass plates (0.5 mm thick, 2500 mm×2500 mm). This weight simulates the actual transportation of the laminated glass body as shown in FIG. That is, as shown in FIG. 1, a laminate is assumed in which the lowermost glass plate of the glass laminate is the evaluation glass plate 12 and the glass plate 13 is laminated via the glass interleaving paper 11 .

In addition, in order to simulate the state of flat stacking as shown in FIG. It is desirable to go to

Next, the laminated body is left for two days in an environment with a temperature of 60° C. and a humidity of 80% (step D), and the evaluation glass plate 12 is removed from the laminated body (step E) and washed (step F).

In the cleaning step (step F), the surface of the evaluation glass plate 12 on which the glass interleaving paper 11 is pressed is washed using a cleaning device, and the glass interleaving paper 11 adheres to the surface of the evaluation glass plate 12 (transfer). remove foreign matter.

In the cleaning apparatus, while conveying the evaluation glass plate 12 at a line speed of 300 cm/min, cleaning water containing an alkaline detergent is supplied from the nozzle 58 at a flow rate of 30 L/min, and an upper first roll brush 60 and a lower The first roll brush 64 is rotated at a rotation speed of 300 rpm (in the same direction as the conveying direction of the glass plate 12 for evaluation) while being in contact with the surface of the glass plate 12 for evaluation.

In this embodiment, the upper first roll brush 60 and the lower first roll brush 64 are all the same roll brush. The roll brush is a tightly wound roll brush having a roll diameter (inner diameter) of 60 mm, a roll diameter (outer diameter) of 80 mm, and a bristle diameter of 0.06 mm. The bristles of the roll brush are composed of nylon 612. Tight winding means winding the flocked channel brush around a roll without gaps.

Further, as shown in FIG. 2A, there is no gap between the upper first roll brush 60 and the lower first roll brush 64, and before the evaluation glass plate 12 passes through, the upper first roll brush The bristles of the 60 and the lower first roll brush 64 are arranged at positions where the bristles come into contact with each other, that is, at a vertical position of 0 mm. Therefore, as shown in FIG. 2B, when the evaluation glass plate 12 passes between the upper first roll brush 60 and the lower first roll brush 64, the upper first roll brush 60 and the lower first roll brush 60 The first roll brush 64 is pressed against the evaluation glass plate 28 with a pressure corresponding to the plate thickness of the evaluation glass plate 12 .

Thereafter, the cleaned evaluation glass plate 12 is inspected using a foreign matter inspection machine (HS730 manufactured by Toray Industries, Inc.) (process G). The foreign matter inspector inspects the surface of the cleaned evaluation glass plate 12 for foreign matter. The foreign matter inspection device inspects foreign matter existing on the surface of the evaluation glass plate 12 and acquires an image (second image) of all the foreign matter.

Next, the evaluation glass plate 12 is washed (process F) and inspected for foreign matter (process G) a plurality of times, and the first image is not obtained and there is no change in the existence position between the plurality of second images. The foreign matter is identified as the immobile foreign matter, and the number of the immovable foreign matter having a major diameter of 10 μm or more per unit area is measured (step H).

In other words, immovable foreign matter refers to foreign matter that adheres or adheres to the glass surface to such an extent that it cannot be completely removed even after multiple cleaning steps. The tensile shear bond strength of immovable foreign matter on the glass plate surface is often 0.05 N/mm ² or more, more often 0.07 N/mm ² or more, and further 0.1 N/mm ² or more. There are many.
The upper limit of the tensile shear bond strength of the immovable foreign matter on the surface of the glass plate is not particularly limited, but is, for example, 0.4 N/mm ² or less.
The tensile shear strength is measured in accordance with JIS K 6850:1999 in a state in which glass substrates are adhered to each other using each polymer as an additive as an adhesive layer.

Note that the cleaning and foreign matter inspection of the evaluation glass plate 12 may be performed at least twice. point to

For example, when washing is performed twice, the second image obtained after the first washing is compared with the second image obtained after the second washing. Often no change. Here, "there is no change in the existing position" is not limited to being completely the same in a strict sense, and is a concept that allows a range to the extent that the gist of the present application is not lost. For example, if the X-coordinate and Y-coordinate of the foreign matter on the glass plate are within a range of ±1 mm between a plurality of second images, it can be considered that there is no change in the existing position.

In addition, when the immobile foreign matter is washed twice, for example, the second image obtained after the first washing is compared with the second image obtained after the second washing, and the outline of the foreign matter in the obtained image is is often 30% or more, more often 50% or more, and more often 70% or more. Immobile foreign matter has a portion that continues to adhere even if a portion of the foreign matter is removed by washing.

The density of the immovable foreign matter can be obtained by the steps A to H described above. If the density of immobile foreign matter having a major diameter of 10 μm or more is 50 particles/m ² or less, it is possible to sufficiently suppress the occurrence of wiring defects. In addition, since it is possible to use additives having properties that can cause non-transferable foreign matter to some extent, it is possible to optimize the physical properties and quality required especially for large-sized glass interleaving papers. In addition, the density of immobile foreign matter having a major axis of 10 μm or more is preferably 40 particles/m ² or less, more preferably 30 particles/m ² or less, and even more preferably 20 particles/m ² or less. As a result, it is possible to further suppress the occurrence of defects such as wiring.
In the embodiment of the present invention, the lower limit is not particularly limited as the density of immovable particles having a major axis of 10 μm or more is preferably as low as possible. However, it is difficult to remove them completely, and glass interleaving paper, which has an extremely low density of immovable foreign matter with a major diameter of 10 μm or more, requires labor and cost to manufacture. Considering this point, it is preferable that the density of immovable foreign matter having a major diameter of 10 μm or more is 3 particles/m ² or more.
Moreover, although the upper limit of the size of the immovable foreign matter is not particularly limited, for example, the long axis is 1000 μm or less.

In addition, the glass interleaving paper has a first additive, and the first additive is the 180° peeling adhesive strength specified in JIS Z 0237: 2009 (hereinafter simply referred to as "180° peeling adhesive strength" ) is preferably 10 N/25 mm or less. As a result, even if the additive component is pressure-bonded to the evaluation glass plate 12, it can be easily removed by the cleaning process (process F), and the possibility of becoming an immobile foreign matter can be reduced. By using the first additive, the physical properties and quality required for the glass interleaving paper can be optimized. The 180° peeling adhesive strength of the first additive is more preferably 8 N/25 mm or less, still more preferably 5 N/25 mm or less.
In the embodiment of the present invention, the lower limit of the 180° peeling adhesive strength of the first additive is preferably as small as possible, and the lower limit is not particularly limited. However, in order to optimize the physical properties and quality required for the glass interleaving paper, it may be necessary to use one with a certain degree of 180° peeling adhesive strength. Considering this point, the 180° peeling adhesive strength of the first additive is preferably 0.02 N/25 mm or more.
Using each polymer as an additive as an adhesive layer, a glass substrate and a tape-shaped base material (glass interleaving paper) are adhered, and when the adhesive layer is peeled off together with the tape-shaped base material (glass interleaving paper), If it peels off at the interface between the glass interleaving paper and the adhesive layer, it means that the adhesive layer is attached to the glass with more force than that, so the 180° peeling adhesive strength is calculated at the interface between the glass interleaving paper and the adhesive layer. The value when peeled off was adopted.

Moreover, the glass interleaving paper may have a second additive having a 180° peeling adhesive strength defined in JIS Z 0237:2009 greater than 10 N/25 mm. In this case, and when the interaction distance of the Hansen solubility parameter for water, which will be described later, is greater than 17, the second additive is preferably 10 ppm or less by weight of the glass interleaving paper, more preferably 8 ppm or less. , more preferably 5 ppm or less. By using a small amount of the second additive, while optimizing the physical properties and quality required for the glass interleaving paper, the density of immobile foreign matter on the surface of the glass plate in contact with the glass interleaving paper can be suppressed within an allowable range.
In addition, in the embodiment of the present invention, the content of the second additive is preferably as small as possible, and the lower limit is not particularly limited. However, glass interleaving paper with an extremely low content of the second additive is laborious and costly to manufacture. Considering this point, the content of the second additive is preferably 0.05 ppm or more.

Further, the first additive preferably has an interaction distance of 17 or less in Hansen solubility parameter (also referred to as HSP) for water at 25°C.

Here, the Hansen solubility parameter is an index showing the ease of dissolving a certain solute in a certain solvent. Further, the interaction distance Ra1 (also referred to as HSP vector distance _Ra1 ) obtained from the value of the Hansen solubility parameter for water of the first additive is represented by the following equation (1).
Ra ₁ = (4×( _δD1 −18.1) ² +( _δP1 −17.1) ² +( _δH1 −16.9) ² ) ^0.5 (1)
Ra ₁ : Interaction distance of Hansen solubility parameters for water δ _D1 : Among Hansen solubility parameters of additives, dispersion force term δ _P1 : Among Hansen solubility parameters of additives, force term between dipoles δ _H1 : Additives Among _{the Hansen solubility} parameters, the hydrogen bonding force term It is divided into components and shown in three-dimensional space. The dispersion term _δD indicates the effect due to dispersion forces, the polar term _δP indicates the effect due to the dipole force, and the hydrogen bonding term _δH indicates the effect due to hydrogen bonding force. The closer the coordinates of a particular substance X and the coordinates of a certain solvent in the three-dimensional space are, the easier the substance X is to dissolve in the solvent. Details of the definition of the Hansen Solubility Parameter and the method of calculation can be found in the following references; Hansen, "Hansen Solubility Parameters: A Users Handbook," CRC Press, 2007.

Moreover, by using computer software (Hansen Solubility Parameters in Practice (HSPiP)), Hansen solubility parameters can be easily estimated from the chemical structure.

In the present invention, HSPiP version 4.1.07 is used, the values are used for substances registered in the database, and the estimated values are used for substances not registered.

If the interaction distance of the additive with respect to water is 17 or less, the first additive is easily dissolved in water, so that it can be easily removed in the washing step (step F), and the possibility of becoming immobile foreign matter can be reduced. The interaction distance Ra ₁ of the Hansen solubility parameter for water of the first additive is more preferably 15 or less, and even more preferably 12 or less. Since it becomes easier to dissolve in water, the possibility of becoming an immovable foreign matter can be reduced.

In addition, the glass interleaving paper has a 180 ° peeling adhesive strength specified in JIS Z 0237: 2009, even if the second additive is greater than 10 N / 25 mm, if the following conditions are satisfied, the weight with respect to the glass interleaving paper Even ratios in the range greater than 10 ppm may have a second additive. The condition is that, in the second additive, the interaction distance Ra ₂ of the Hansen solubility parameter for water at 25° C. is 17 or less. The interaction distance _Ra2 is represented by Equation (2) below.
Ra ₂ = (4×( _δD2 −18.1) ² +( _δP2 −17.1) ² +( _δH2 −16.9) ² ) ^0.5 (2)
Ra ₂ : interaction distance δ _D2 of the Hansen solubility parameter for water of the second additive: dispersion force term δ _P2 of the Hansen solubility parameter of the additive : force term between dipoles of the Hansen solubility parameter of the additive δ _H2 : Hydrogen bonding force term in the Hansen solubility parameter of the additive The interaction distance Ra ₂ of the Hansen solubility parameter in water of the second additive is more preferably 15 or less, more preferably 12 or less. While optimizing the physical properties and quality required for the glass interleaving paper, the density of immobile foreign matter on the surface of the glass plate in contact with the glass interleaving paper can be suppressed within the allowable range.

In addition, when the second additive has a 180° peeling adhesive strength defined in JIS Z 0237:2009 greater than 10 N/25 mm and an interaction distance Ra ₂ with respect to water greater than 17, as described above, The weight ratio to the glass interleaving paper is preferably 10 ppm or less, preferably 8 ppm or less, more preferably 5 ppm or less. While optimizing the physical properties and quality required for the glass interleaving paper, the density of immobile foreign matter on the surface of the glass plate in contact with the glass interleaving paper can be suppressed within an allowable range.
In addition, in the embodiment of the present invention, the content of the second additive is preferably as small as possible, and the lower limit is not particularly limited. However, glass interleaving paper with an extremely low content of the second additive is laborious and costly to manufacture. Considering this point, the content of the second additive is preferably 0.05 ppm or more.

In addition, representative examples of additives added to glass interleaving paper, main purposes, and main components that can cause immovable foreign matter are described below.

When the first additive and the second additive are not particularly distinguished, they are simply referred to as "additives".

The internal paper strength enhancer is used mainly for the purpose of improving the strength of paper. A representative example of the main component is polyacrylamide (PAM).

The pitch control agent is used mainly for the purpose of dispersing pitch (sticky substance derived from resin or drug) or discharging it out of the system. Typical examples of main components are cationic polymers such as cationic (C-) PAM, polyethyleneimine (PEI), and C-acryl, surfactants, polyacrylic acid, polyvinyl alcohol (PVA), and PAM.

A coagulant is used for the main purpose of making the fiber particles into small dense aggregates. Since the pulp slurry and fiber particles are anionic, they are neutralized and coagulated by a cationic coagulant. In addition, an effect of fixing anionic sticky foreign matter to the pulp and preventing roll staining can also be obtained. Representative examples of main components are polydiallyldimethylammonium chloride (PDADMAC), PEI, cationic starch (CS).

A dry paper strength enhancer is used mainly for the purpose of improving the strength of paper, especially in a dry state. Representative examples of main components are polyacrylate (AE), CS, PAM and PVA.

Wet paper strength agents are used mainly for the purpose of improving the strength of paper, especially in a wet state. Typical examples of main components are AE, polyamide polyamine epichlorohydrin (PAE), PVA, polyvinylamine (PVAm), melamine (formaldehyde) resin (MF), urea (formaldehyde) resin (UF), polyvinyl chloride (PVC) ), polyvinylidene chloride (PVDC).

The internal sizing agent is used mainly for the purpose of suppressing water permeability, suppressing bleeding, and enhancing water resistance. Representative examples of main components are AE, rosin, PVA, alkylketene dimer (AKD), alkenylsuccinic anhydride (ASA), carboxymethylcellulose (CMC).

A surface sizing agent is used for the main purposes of suppressing water permeability, suppressing bleeding, and enhancing water resistance. Typical examples of main components are oxidized starch (OS) and styrene-acrylic copolymer (AS).

The viscosity agent is used mainly for the purpose of increasing viscosity, uniformly dispersing pulp fibers in water, and preventing sedimentation. Representative examples of main components are AE, PAM, polyethylene oxide (PEO), CMC and alginic acid (AA).

The main purpose of the water-resistant cross-linking agent is to improve water resistance and strength by cross-linking. A representative example of the main component is an epoxy resin (ER).

The main purpose of the adhesive is to bond paper together with a Yankee dryer. The main components are AE, styrene-butadiene copolymer rubber (SBR) and starch.

As a general rule, the additives mentioned above should be used in appropriate amounts for their respective main purposes. Therefore, it is desirable that the immobile foreign matter contains at least one selected from the group consisting of the above substances and derivatives derived from the above substances. When the additive corresponds to the second additive, it is preferable that the interaction distance to water is 17 or less, or the weight ratio to the glass interleaving paper is 10 ppm or less.

In particular, it is desirable that the additives and immovable foreign matter contain substances that are highly effective for each purpose of each papermaking chemical. That is, alginic acid, polyacrylic acid ester, alkyl ketene dimer, styrene-acrylic copolymer, alkenyl succinic anhydride, epoxy resin, melamine resin, polyamide polyamine epichlorohydrin, polyvinyl chloride, polyvinylidene chloride, styrene-butadiene copolymer It preferably contains at least one substance selected from the group consisting of polymer rubber, rosin, polyethylene terephthalate, and derivatives thereof.

In addition, even if these substances are used, the density of immobile foreign matter with a major diameter of 10 μm or more present on the surface of the glass plate is limited to 50 particles/m ² or less. It is preferred to use

Thereby, while optimizing the physical properties and quality required for the glass interleaving paper, the density of immobile foreign matter on the surface of the glass plate in contact with the glass interleaving paper can be suppressed within the allowable range.

Moreover, it is preferable that at least a part of the additive protrudes from the surface of the glass interleaving paper. That is, it is preferable that at least one of at least a portion of the first additive and at least a portion of the second additive protrude from the surface of the glass interleaving paper. Since the additive protrudes from the surface of the glass interleaving paper, the additive is easily detached from the glass interleaving paper when the glass interleaving paper is subjected to the washing process described below.

The additive is preferably dispersed in the glass interleaving paper and solidified at 20°C. This is to prevent the glass interleaving paper from adhering to each other when the glass interleaving paper is rolled.

As for the composition of the glass plate, the following is preferable because it is difficult for foreign matter to adhere and the density of immovable foreign matter tends to be low. Note that, for example, "containing 0 to 7% of B ₂ O ₃ " means that B ₂ O ₃ is not essential but may be contained up to 7%.
(i) Composition expressed in % by weight, 57-67% SiO ₂ , 15-25% Al ₂ O ₃ , 0-7% B ₂ O ₃ , 0-5% MgO, 2-2% CaO A glass containing 7%, 0-5% SrO, and 5-12% BaO.
₍ ii) _a composition _{expressed in} wt _. 10%, 4-10% SrO, and 0-3% BaO.

Moreover, below, it describes about the manufacturing method of the glass interleaving paper which concerns on this embodiment. FIG. 3 is a schematic configuration diagram of a paper machine 100 that manufactures glass interleaving paper.

As shown in FIG. 3 , a raw material liquid for glass interleaving paper (a liquid obtained by diluting pulp with water; also referred to as pulp slurry) is passed from a head box 112 onto a lower wire 116 installed in a wire part 114 in the form of a sheet. supplied to The paper stock liquid supplied to the lower wire 116 is then sandwiched between the lower wire 116 and the upper wire 118 to spread to a uniform thickness and dehydrated to form wet paper (paper).

The lower wire 116 and the upper wire 118 of the wire part 114 are permeable membranes formed in endless strips. Specifically, it is a net made of plastic or metal material, or an endless belt made of felt made of natural or synthetic fibers.

The lower wire 116 and the upper wire 118 are stretched over a plurality of rollers, and are circulated at a predetermined speed by transmitting the driving force of a motor (not shown) to the drive rollers among the plurality of rollers. there is

The wet paper web formed by the wire part 114 is conveyed to a press part 120 having a press roller, an endless band of felt, a pair of press rollers, etc., where further dewatering and pressing are performed simultaneously.

The wet paper web that has passed through the press part 120 is transported to a dryer part 124 composed of a plurality of rollers, and dried in an atmosphere of about 120° C., for example, while passing through the dryer part 124 .

The paper dried in the dryer part 124 is conveyed to the calender part 126, where it is calendered by nipping and conveying by calender rolls to smooth the front and back surfaces. If necessary, a coater part may be provided between the dryer part 124 and the calender part 126 to apply paint or the like to the smoothed surface of the paper.

The paper calendered in the calender part 126 is wound around a reel 128 as a glass interleaving paper and formed into a roll (hereinafter referred to as a jumbo roll 130).

The glass interleaving paper is sent out from the jumbo roll 130 , cut into a predetermined width by the cutter 134 (cut in the longitudinal direction), and wound up by the winder 136 . When the glass interleaving paper sent out from the jumbo roll 130 reaches a predetermined length, it is cut to a predetermined length (cut in the width direction) by the cutter 134, and a long glass interleaving paper is formed with a predetermined width. An interleaving paper roll 42 is formed by winding.

The long glass interleaving paper wound around the interleaving paper roll 42 is cut into a cut sheet shape (rectangular shape) having a size corresponding to the glass plates to be laminated, and is interposed between the laminated glass plates.

In this embodiment, a preparation step of preparing pulp as a raw material when preparing the paper raw material liquid to be supplied to the head box 112, a pulp slurry step of producing a pulp slurry from the pulp, and a paper making of glass interleaving paper from the pulp slurry. and a step. At least one step selected from the group consisting of the preparation step, the pulp slurry step and the papermaking step is preferably carried out using a member whose surface is covered with the following substances. That is, at least one selected from the group consisting of metals having heat resistance and solvent resistance, carbon fibers, and resins having a 180° peeling adhesive strength of 0.02 N / 25 mm or less as defined in JIS Z 0237: 2009. , the above step is preferably performed using a member whose surface is covered. Thereby, it is possible to prevent the addition of additives that cause immovable foreign matter in the manufacturing process of the glass interleaving paper.

Here, the "members" include, for example, trays used in the preparation process, containers and stirring blades used in the pulp slurry process, and wires, felts, and rollers used in the papermaking process. Moreover, the metal having heat resistance means that the softening point is 100° C. or higher.

In addition, if the member is covered with a resin having a 180° peeling adhesive strength of 0.02 N / 25 mm or less, even if foreign matter derived from the member is mixed in the glass interleaving paper manufacturing process, after the steps C to E It does not easily remain on the glass surface. Moreover, even if it adheres, it is easy to remove in the washing process (process F), and does not easily become an immovable foreign matter adhered to the surface of the glass plate.

In addition, when manufacturing different types of paper, if the manufacturing equipment and parts are not cleaned sufficiently at the time of job change, the additives added to the previously produced paper will remain on the surface of the parts, etc. Sometimes added to paper. In particular, substances that are likely to cause immovable foreign matter include, for example, alginic acid, polyacrylic acid esters, alkylketene dimers, styrene-acrylic copolymers, alkenyl succinic anhydrides, epoxy resins, melamine resins, polyamide polyamine epichlorohydrin. , polyvinyl chloride, polyvinylidene chloride, styrene-butadiene copolymer rubber, rosin, and the like.

Since it is very difficult to strictly clean paper manufacturing equipment and members, these resin components are contained in the glass interleaving paper as long as the density of immovable foreign matter can be suppressed within the allowable range. may That is, if the weight ratio of the glass interleaving paper is 10 ppm or less, preferably 8 ppm or less, and even more preferably 5 ppm or less, it may be added to the glass interleaving paper. Since it is not necessary to strictly wash manufacturing equipment and members, the burden on workers is reduced.

In addition, when the material of the surface of the manufacturing equipment and members is polyethylene terephthalate (PET), it may be detached and added to the glass interleaving paper, which may also cause immovable foreign matter. In this case, the amount of PET added is preferably controlled to be 10 ppm or less, more preferably 8 ppm or less, more preferably 5 ppm or less in terms of weight ratio of the glass interleaving paper. For example, it is conceivable to form a protective layer or the like on the surface of a member, or to replace a member that has deteriorated over time at an early stage. As a result, PET, which is a versatile and easy-to-process material, can be used as a material for manufacturing equipment and members.

Moreover, in the present embodiment, the method for producing the glass interleaving paper preferably further includes a step of removing additives contained in the pulp or the glass interleaving paper, and the removal is preferably performed by dissolution. The removing step preferably includes at least one step selected from the group consisting of the following (i) to (iii).

(i) a step of stirring and washing the pulp and/or the glass interleaving paper before drying and/or the glass interleaving paper after drying with washing water containing an organic solvent, an alkaline detergent, or washing water containing an acid detergent; .
(ii) a step of shower-washing the pulp and/or the glass interleaving paper before drying and/or the glass interleaving paper after drying with washing water containing an organic solvent, an alkaline detergent, or washing water containing an acid detergent; .
(iii) A step of passing and washing the glass interleaving paper before drying and/or the glass interleaving paper after drying in a water tank filled with washing water containing an organic solvent, an alkaline detergent, or an acidic detergent. .
As a result, even if a substance that causes immovable foreign matter is mixed in the manufacturing process of the glass interleaving paper, it is possible to suppress the generation of immovable foreign matter after the steps C to E.

An embodiment of the present invention will be shown below, and the effects of the present invention will be described.

First, NBKP 100% by mass pulp was beaten to obtain a freeness CSF of 450 ml, and the additives listed in Table 1 below were added to a plurality of pulp slurries to prepare pulp slurries each having a concentration of 0.5% by mass. bottom. The paper was made by the inventor using a manual paper-making device using nylon as a felt material. As a result, a glass interleaving paper having a size of 490 mm×390 mm and a thickness of about 0.08 mm was obtained.

Next, the evaluation glass plate (thickness: 0.5 mm, 470 mm x 370 mm) was inspected using a foreign substance inspection machine (HS730 manufactured by Toray Industries, Inc.) to obtain a first image of all foreign substances.

Next, the evaluation glass plate and the glass interleaving paper were laminated, and the weight of 200 glass plates (50 kg) was placed on the laminate and left for 2 days in an environment of 60° C. temperature and 80% humidity.

After that, the glass plate for evaluation was taken out and washed to remove foreign matters. Washing was carried out using the washing apparatus shown in step F.

After that, it was inspected again by the foreign matter inspection machine to obtain a second image of all the foreign matter existing on the surface of the glass plate for evaluation. After that, cleaning and foreign matter inspection were performed again, and a total of two second images were obtained. Based on these results, a foreign object for which the first image could not be obtained and whose position did not change between the two second images was identified as an immovable foreign object.

Table 1 shows the results. In Table 1, “×” indicates that the density of immobile foreign matter with a major axis of 10 μm or more was confirmed to be more than 50/m ² , and “◯” indicates that the density of immovable foreign matter with a major axis of 10 μm or more was 50/m ² or less. Show things.

From Table 1, when the additive was polytetrafluoroethylene or polyvinyl alcohol, the density of immovable foreign matter with a major diameter of 10 μm or more could be reduced to 50 particles/m ² or less.

FIG. 4 also shows the length of the Hansen Solubility Parameter (HSP) vector of each additive (polymer) and the interaction distance Ra of the Hansen Solubility Parameter with respect to water. The length of the Hansen solubility parameter vector indicates (δ _D ² +δ _P ² +δ _H ² ) ^0.5 .

As shown in FIG. 4, polyvinyl alcohol has a small interaction distance Ra with respect to water, and therefore is easily dissolved in the washing process, and it is considered that the density of immovable foreign matter having a major axis of 10 μm or more is 50 particles/m ² or less. In addition, since polytetrafluoroethylene has a small 180° peeling adhesive strength, it is difficult to adhere to glass, and even if it adheres, it easily falls off from the glass plate during the cleaning process. It is thought that the number of pieces/m ² or less.

5A and 5B are diagrams showing images of the obtained immovable foreign matter. FIG. 5(A) is a second image of the foreign matter obtained after the first cleaning step (step F), and FIG. 5(B) is a second image of the foreign matter obtained after the second cleaning step (step F). show. Note that both FIGS. 5A and 5B are images in which the obtained second image is binarized and the outline is clearly shown. From FIGS. 5A and 5B, the coincidence rate of the outline of the immobile foreign matter was 80%.

10 glass plate laminate 11 glass interleaving paper 12 glass plate for evaluation 13 glass plate 14 cleaning device 42 interleaving paper roll 58 nozzle 60 upper first roll brush 64 lower first roll brush 112 head box 114 wire part 116 lower wire 118 top Wire 120 Press Part 124 Dryer Part 126 Calendar Part 128 Reel 130 Jumbo Roll 134 Cutter 136 Winder

Claims (6)

A glass interleaving paper interposed between the glass plates when laminating a plurality of glass plates,
The glass interleaving paper consists of raw materials and additives dispersed in the glass interleaving paper,
The additive comprises a first additive and a second additive ,
The first additive has an interaction distance Ra ₁ of 12 or less in the Hansen solubility parameter for water at 25 ° C., represented by the following formula (1) , and JIS Z 0237: 180 ° peeling specified in 2009 Adhesive strength is 10 N / 25 mm or less,
The second additive has a 180° peeling adhesive strength of greater than 10 N/25 mm as defined in JIS Z 0237:2009,
The glass interleaving paper , wherein the weight ratio of the second additive to the glass interleaving paper is 10 ppm or less .
Ra ₁ = (4×( _δD1 −18.1) ² +( _δP1 −17.1) ² +( _δH1 −16.9
) ² ) ^0.5 (1)
Ra ₁ : Interaction distance of the Hansen solubility parameter for water of the first additive δ _D1 : Among the Hansen solubility parameters of the first additive, the dispersion force term δ _P1 : Among the Hansen solubility parameters of the first additive, the dipolar Force term δ _H1 : Hydrogen bond term among the Hansen solubility parameters of the first additive 2. The glass interleaving paper according to claim 1 , wherein the second additive is at least one selected from substances in the following groups and derivatives derived from substances in the following groups.
Alginic acid, polyacrylate, alkyl ketene dimer, styrene-acrylic copolymer, alkenyl succinic anhydride, epoxy resin, melamine resin, polyamide polyamine epichlorohydrin, polyvinyl chloride, polyvinylidene chloride, styrene-butadiene copolymer rubber, rosin, polyethylene terephthalate The glass interleaving paper according to claim 1 or 2, wherein the second additive has an interaction distance Ra ₂ of the Hansen solubility parameter for water of 12 or less at 25 ° C., represented by the following formula (2) .
Ra ₂ = (4×( _δD2 −18.1) ² +( _δP2 −17.1) ² +( _δH2 −16.9
) ² ) ^0.5 (2)
Ra ₂ : interaction distance of the Hansen solubility parameter for water of the second additive δ _D2 : dispersion force term δ _P2 of the Hansen solubility parameter of the second additive : dipole of the Hansen solubility parameter of the second additive Force term δ _H2 : Hydrogen bond term among the Hansen solubility parameters of the second additive The glass interleaving paper according to any one of claims 1 to 3, wherein at least one of at least part of the first additive and at least part of the second additive protrudes from the surface of the glass interleaving paper. . The glass interleaving paper according to any one of claims 1 to 4, wherein the glass interleaving paper has a thickness of 0.1 mm or less and a short side of 730 mm or more. A glass plate laminate in which the glass interleaving paper according to any one of claims 1 to 5 is interposed between a plurality of glass plates.

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