KR20220029487A - Slip sheet for glass plate - Google Patents

Abstract

The purpose of the present invention is to provide a laminate for a glass plate, which restrains attachment of a foreign substance containing silicon, and especially, a silica foreign substance of a micro-size on a surface of a glass plate. The laminate for a glass plate uses cellulose pulp as a main component. When X is silicon concentration measured by fluorescence X-ray analysis, and Y is calcium concentration, the X is 200ppm or less, and an X/Y ratio, which is a value dividing the silicon concentration by the calcium concentration, is 4.00 or less.

Description

Sheet for glass plate {SLIP SHEET FOR GLASS PLATE}

This invention relates to the paper for glass plates, a glass plate laminated body, and a glass plate package.

In a glass plate used for a flat panel display (FPD) such as a liquid crystal display, fine electronic wiring (hereinafter, also referred to as "wiring") is formed on the surface of the glass plate. cause of Therefore, high cleanliness is calculated|required by the surface of a glass plate.

A glass plate is conveyed by overlapping a glass plate for the purpose of improving conveyance efficiency. At this time, between adjacent glass plates, the paper for glass plates (henceforth simply referred to as "paper") is interposed, and it is suppressing that a flaw etc. generate|occur|produce on the glass plate surface during conveyance.

However, foreign substances may adhere to the surface of the glass plate from the paper under the influence of foreign substances or various chemical substances mixed in the process of manufacturing the paper. Although most of the foreign material adhering to the glass plate surface is removed by washing|cleaning before the process of forming wiring on the glass plate surface, it remains on the glass plate surface even after washing|cleaning, and there exists a possibility that it may become a cause, such as disconnection. Therefore, the paper for glass plates which reduces the foreign material adhering to the surface of a glass plate is calculated|required.

In patent document 1, it is going to reduce the surface contamination of a glass plate by making low density|concentration, such as aluminum, a silicon, and magnesium, contained in the paper for glass plates.

Japanese Patent Laid-Open No. 2017-210286

However, with the high-definition display of recent years, when the width and pitch of wiring formed in the surface of a glass plate become narrower than before, even if you use the paper for glass plates like patent document 1, for example, at the time of wiring formation Problems such as disconnection have occurred.

As a result of the inventors investigating the said problem, it discovered that the micro-size silica foreign material which remained on the glass plate surface even after washing|cleaning was the cause. Since it is difficult to remove a micro-sized silica foreign material by the washing|cleaning process before forming a wiring, it is important not to make a micro-sized silica foreign material adhere to the surface of a glass plate.

An object of this invention is to provide the paper for glass plates which suppresses generation|occurrence|production of defects, such as disconnection at the time of wiring formation, by suppressing that a microsize silica foreign material adheres to the surface of a glass plate.

The paper for glass plates according to the present invention has cellulose pulp as a main component, and has a basis weight of 10 g/m 2 or more and 100 g/m 2 or less, and the glass sheet paper is the silicon concentration measured by fluorescence X-ray analysis X, calcium concentration When Y is, X is 200 ppm or less, and the X/Y ratio, which is a value obtained by dividing the silicon concentration by the calcium concentration, is 4.00 or less.

It is preferable that the X/Z ratio which is the value which divided the silicon concentration by the magnesium concentration when the said paper for glass plates makes the magnesium concentration measured by fluorescence X-ray analysis Z be 3.00 or less.

Z is preferably 20 ppm or more and 100 ppm or less.

The Y is preferably 20 ppm or more and 400 ppm or less.

As for the said paper for glass plates, it is preferable that the number of the silicon-containing foreign material of 0.5 micrometer or more and 50 micrometers or less which exists in at least one paper surface is 2000 pieces/mm<2> or less.

As for the said paper for glass plates, it is preferable that the number of the silicon-containing foreign material of 1 micrometer or more and 10 micrometers or less which exists in at least one paper surface is 1000 pieces/mm<2> or less.

As for the said paper for glass plates, it is preferable that the number of the silica foreign material of 0.5 micrometer or more and 50 micrometers or less which exists in at least one paper surface is 100 pieces/mm<2> or less.

As for the said paper for glass plates, it is preferable that the number of the silica foreign material of 1 micrometer or more and 10 micrometers or less which exists in at least one paper surface is 50 pieces/mm<2> or less.

It is preferable that the air permeation resistance of the paper for glass plate is 5 second or more.

The glass plate laminated body which concerns on this invention laminates|stacks at least 2 or more sheets of glass plates, and has the paper for glass plates which concerns on this invention between adjacent glass plates.

The glass plate package which concerns on this invention has the said glass plate laminated body and the pallet which mounts the said glass plate laminated body.

The paper for glass plates which suppresses that the silica foreign material of a micro size adheres to the surface of a glass plate can be provided. Thereby, generation|occurrence|production of defects, such as disconnection at the time of wiring formation, can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a conceptual diagram which shows the manufacturing method of the paper for glass plates.
It is a conceptual diagram which shows the pallet which loads a glass plate.
It is a conceptual diagram which shows one Embodiment of a glass plate package.

Hereinafter, preferable embodiment of the paper for glass plates which concerns on this invention is demonstrated. Embodiment described below is an example, and this invention is limited to these embodiment and is not interpreted.

A glass plate laminates|stacks at least 2 sheets or more of glass plates from a viewpoint of conveyance efficiency, it mounts on a pallet, and is conveyed. At least 2 or more glass plates are laminated|stacked, what sandwiched the paper between adjacent glass plates is called a glass plate laminated body, and what loaded the said glass plate laminated body on the pallet is called a glass plate package. Glass plate laminate WHEREIN: When glass plates contact, there exists a possibility that a flaw may arise on the surface of a glass plate. It is known that such a flaw causes problems, such as disconnection, in manufacturing processes, such as a display. Then, it is suppressing that a flaw arises on the surface of a glass plate by interposing the paper for glass plates between a glass plate and a glass plate.

However, when the foreign material contained in the paper for glass plates adheres to the surface of a glass plate, problems, such as disconnection, may arise. In particular, with the high-definition display of recent years, even if it used the paper for glass plates which did not become a problem conventionally, problems, such as disconnection, have come to arise.

Then, the present inventors analyzed the foreign material adhering to the glass plate. As a result, it became clear that many silicon-containing foreign materials had adhered to the surface of a glass plate. Furthermore, it has been discovered that among the silicon-containing foreign substances, silica foreign substances having a particularly small size are difficult to be removed by washing before wiring formation, and remain there even after washing to cause a problem. In this specification, the silica foreign material of a micro size means a silica foreign material whose longest diameter is 10 micrometers or less.

In addition, since the silica foreign material having the longest diameter of more than 10 μm is easy to remove by washing performed before forming the wiring on the glass plate, compared to the silica foreign material having the longest diameter of 10 μm or less, it causes defects such as disconnection. I think it's hard to be the cause.

Among the silicon-containing foreign substances, silica foreign substances having a particularly small size are difficult to be removed by washing, and are likely to remain after washing. This is considered to be the reason that silicon-containing foreign substances other than silica foreign substances such as talc have many spherical shapes, whereas the silica foreign substances have a flat shape in many cases. That is, in the case of a flat shape, since the height is low, for example, since it is difficult to remove by cleaning processes, such as brush cleaning, it is thought that it is easy to remain|survive.

Moreover, inventors discovered that the silica foreign material which remain|survives on the surface of a glass plate is what adhered to the surface of a glass plate from paper. From the above, it is important to reduce the silica foreign material of the micro size which exists in the paper for glass plates.

(Manufacturing method of paper for glass plate)

The raw material liquid (liquid obtained by diluting pulp with water) of the paper for glass plates is supplied from the head box 112 on the lower wire 116 provided in the wire part 114 in a sheet form. The raw material solution supplied to the lower wire 116 is then sandwiched by the lower wire 116 and the upper wire 118 to expand to a uniform thickness, and is dehydrated to become wet paper (paper).

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

The lower wire 116 and the upper wire 118 span a plurality of rollers, and by transmitting the driving force of a motor (not shown) to a driving roller among the plurality of rollers, they are moved around at a predetermined speed.

The wet paper formed from the wire part 114 is conveyed to the press part 120 having a press roller, an endless belt-shaped felt, a press roller stand, and the like, where further dewatering and pressing are performed.

The wet paper which has passed through the press part 120 is conveyed to the dryer part 124 comprised by the several roller, and is dried in the atmosphere of about 120 degreeC while passing through the dryer part 124, for example.

When passing through the dryer part 124 , if the wet paper is conveyed at high speed as it is, there is a risk of paper cutting. Therefore, it is conveyed in a state in which an auxiliary member called a canvas is brought into contact with the wet paper.

The paper dried by the dryer parts 124 may be conveyed to the calender parts 126, calendered by clamping conveyance by a calender roll, etc., and the front and back surfaces may be smoothed. In addition, if necessary, a coater part may be provided between the dryer parts 124 and the calender parts 126 , and a paint or the like may be applied to the smoothed surface of the paper.

The paper to which the calendering process was performed in the calender parts 126 is wound up on the reel 128 as paper for glass plates, and turns into roll shape (it is set as the jumbo roll 130 hereafter).

The jumbo roll 130 for glass plate paper is usually, for example, the glass plate paper is cut to a width according to the product and wound, and a long glass plate paper of a predetermined length of about 8000 to 10000 m is wound on a paper roll ( 42) becomes.

The paper for glass plates is sent out from the jumbo roll 130 , is cut (cut in the longitudinal direction) to a predetermined width by the cutter 134 , and is wound up by the winder 136 . When the paper for glass plates sent out from the jumbo roll 130 becomes a predetermined length, it is cut|disconnected (cut|disconnected in the width direction) to predetermined length by the cutter 134, and it is predetermined width, and the long paper for glass plates is wound. It becomes the paper roll 42 formed by doing it.

The paper for elongate glass plates wound by the paper roll 42 is cut|disconnected in the cut sheet shape (rectangular shape) of the size according to the glass plate to laminate, and is interposed between the glass plates laminated|stacked.

(silicon concentration)

Silicon contained in the paper for glass plates originates in the cellulose pulp and water mainly used as a raw material, and the dust in the air mixed in a manufacturing process. Silicon is mainly present as a silicon-containing foreign material such as hydrous magnesium silicate (hereinafter also referred to as "talc") or silica in the manufactured paper for glass plates.

The paper for glass plates of this invention fully reduces the silica foreign material of the paper for glass plates by making the silicon concentration at the time of measuring by fluorescent X-ray analysis 200 ppm or less, and suppresses generation|occurrence|production of defects, such as disconnection.

The silicon concentration is preferably 150 ppm or less, more preferably 130 ppm or less, still more preferably 100 ppm or less, and particularly preferably 50 ppm or less.

In addition, in this specification, the silicon density|concentration at the time of measuring the paper for glass plates by fluorescent X-ray analysis is also called X. X is measured by the following method.

(Method for measuring silicon concentration X)

The X-ray fluorescence analysis in the present invention can be performed using, for example, a commercially available X-ray fluorescence analyzer such as ZXS PRIMUS (Rigaku, Ltd.). As a pretreatment for fluorescence X-ray analysis, the paper for glass plate is cut in advance to a size suitable for measurement with a knife or the like. The cut paper is loaded on the sample stand. At this time, a high-purity sample stand with a known composition may be used in advance so that the components of the sample stand do not become noise in the measurement, a cup-shaped sample stand with a deep bottom may be used, or paper for glass plates may be overlapped. Next, use a cover with an open hole in the measurement area and fix the paper for glass plate. After the sample stand is put in a fluorescent X-ray analysis apparatus and the inside of an apparatus is made into a vacuum, X-rays are irradiated to a measurement surface, and the fluorescent X-ray which generate|occur|produced from the paper for glass plates is measured and analyzed.

Since stable results are obtained as the evaluation area is wider, the evaluation area is preferably 10 square millimeters or more, more preferably 100 square millimeters or more, and still more preferably 600 square millimeters or more. In this specification, unless otherwise specified, the evaluation area is 700 square millimeters.

For the quantification of the detection element, a reference sample having a known concentration was measured in advance, and then the numerical value of each element was corrected from the X-ray intensity. The electric power at the time of measurement was set to 3000W.

At the time of measurement, content of each element of sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, potassium, calcium, iron, nickel, copper, and zircon was quantified.

When silicon density|concentration is too small, the foamability at the time of stirring the raw material liquid of the paper for glass plates may be bad, and a hole may be opened in the paper for glass plates. Therefore, silicon concentration becomes like this. Preferably it is 10 ppm or more, More preferably, it is 15 ppm or more, More preferably, it is 20 ppm or more.

Silicon concentration is influenced by the cellulose pulp of a raw material, the water of a raw material, and the manufacturing method of paper.

The silicon concentration can be reduced by selecting the cellulose pulp as the raw material that does not contain silicone oil or has a small amount of use, does not contain talc as a pitch control agent, or has been removed by applying a strong centrifugal force to fine ore and dust. can The silicon concentration can also be made small by using water which removed the silicon component derived from the ore of groundwater or river water by sufficient filtration etc. as raw material water. In addition, in the manufacturing method of the paper, by performing the sheeting step in a clean room, the penetration of dirt is prevented, or by separating the sheeting step using cellulose pulp containing silicone oil and the sheeting step of the paper for glass plate, the silicon concentration can be made smaller

Examples of the cellulose pulp include chemical pulps such as kraft pulp (KP), sulfite pulp (SP), and soda pulp (AP); semi-chemical pulps such as semi-chemical pulp (SCP) and chemical ground wood pulp (CGP); mechanical pulps such as ground wood pulp (GP), thermomechanical pulp (TMP, BCTMP), and refiner ground wood pulp (RGP); non-wood fiber pulp made from mulberry, cedar mulberry, hemp, kenaf, etc. as raw materials; synthetic pulp; etc., the paper for glass plates containing various raw materials can be used. Moreover, what mixed these may be sufficient.

(Calcium Concentration)

Calcium contained in the paper for glass plates is derived from the cellulose pulp and water mainly used as a raw material, and the dust in the air mixed in the manufacturing process. Calcium is present in the manufactured paper for glass plates, for example, as a silicon-containing foreign material or calcium carbonate such as calcium meta silicate and ortho calcium silicate.

In this specification, the calcium concentration at the time of measuring the paper for glass plates by fluorescence X-ray analysis is also called Y. Y is measured by a procedure similar to the above (method for measuring silicon concentration X).

The smaller the X/Y ratio, which is a value obtained by dividing the silicon concentration by the calcium concentration, means that a large amount of calcium exists with respect to the silicon. In addition to existing as calcium carbonate, calcium also exists as a compound containing silicon, such as metacalcium metasilicate and orthocalcium silicate. Therefore, the larger the calcium concentration Y, the smaller the ratio of silicon present as silica, and the silica foreign matter is small. I think it's true

The paper for glass plates of this invention was able to fully reduce the silica foreign material of the paper for glass plates by making X/Y ratio 4.00 or less. The X/Y ratio is preferably 3.50 or less, more preferably 3.00 or less, still more preferably 2.00 or less, particularly preferably 1.00 or less, and most preferably 0.50 or less.

Moreover, when Y is too large, although it is thought that a silica foreign material will decrease, calcium-containing foreign material, such as calcium carbonate, increases, and there exists a possibility of becoming a problem. Therefore, 400 ppm or less is preferable, as for Y, 300 ppm or less is more preferable, and its 250 ppm or less is still more preferable.

Moreover, when Y is too small, the foamability at the time of stirring the raw material liquid of the paper for glass plates may be bad, and a hole may be opened in the paper for glass plates. Therefore, Y becomes like this. Preferably it is 20 ppm or more, More preferably, it is 30 ppm or more, More preferably, it is 50 ppm or more.

By using virgin pulp with a high calcium-containing concentration, the X/Y ratio can be made small.

(magnesium concentration)

Magnesium contained in the paper for glass plates mainly originates in the cellulose pulp and water used as a raw material, and the dust in the air mixed in a manufacturing process. Magnesium is mainly present as a silicon-containing foreign material such as talc in the manufactured paper for glass plates.

In this specification, the magnesium concentration at the time of measuring the paper for glass plates by fluorescence X-ray analysis is also called Z. Z is measured by the same procedure as the above (method for measuring silicon concentration X).

The smaller the X/Z ratio, which is a value obtained by dividing the silicon concentration by the magnesium concentration, means that more magnesium is present with respect to the silicon. As described above, magnesium exists as a silicon-containing compound such as talc. Therefore, it is thought that as Z is larger, the proportion of silicon present as silica decreases and the amount of silica foreign matter decreases.

X/Z ratio of the paper for glass plates of this invention becomes like this. Preferably it is 3.00 or less, More preferably, it is 2.50 or less, More preferably, it is 2.00 or less, Especially preferably, it is 1.00 or less.

Moreover, when Z is large, although it is thought that a silica foreign material will decrease, talc increases and there exists a possibility that it may become a problem. Therefore, 100 ppm or less is preferable and, as for content of magnesium, 70 ppm or less is more preferable. Although the lower limit of Z is not specifically limited, 10 ppm or more is preferable, and 20 ppm or more is more preferable.

(Method for measuring silicon-containing foreign substances and silica foreign substances)

The silicon-containing foreign material is measured by, for example, a scanning electron microscope and an energy dispersive X-ray analyzer installed in the scanning electron microscope. As a pretreatment for measurement, the sample cut into small pieces may be subjected to a conductive film treatment of an element not to be measured, for example, carbon or platinum. After the paper is set in the scanning electron microscope, an element heavier than carbon, which is an element mainly constituting the paper, is discriminated from the contrast of the image using a reflection electron detector. In the method using this reflection electron detector, elements heavier than carbon are usually represented by bright pixels. First, for example, an area of 0.1 mm x 0.1 mm is measured for 100 areas. Next, when measuring the number of silicon-containing foreign substances and silica foreign substances of 1 µm or more and 10 µm or less, foreign substances other than carbon of 1 µm or more are counted. For each foreign material detected by this reflection electron detector, the size is calculated from the number of pixels, and the element is analyzed with an energy dispersive X-ray analyzer for each particle having the longest diameter of 1 µm or more and 10 µm or less, Particles containing 10 wt% or more of silicon among elements other than carbon and oxygen were used as the silicon-containing material. Moreover, the particle|grains containing 80 weight% or more of silicon were made into a silica foreign material.

In the case of measuring the number of silicon-containing foreign substances of 0.5 µm or more and 50 µm or less and silica foreign substances, foreign substances other than carbon of 0.5 µm or more were counted and measured similarly.

When the longest diameter of the silicon-containing foreign material is less than 1 µm and is sufficiently smaller than the wiring width or pitch width, it is difficult to cause problems such as disconnection. Moreover, it turned out that it is difficult to remove by washing|cleaning, so that the longest diameter is small among a silica foreign material, and especially the silica foreign material with a longest diameter of 10 micrometers or less is easy to remain|survive on the surface of a glass plate also after washing|cleaning.

In the paper of this embodiment, it is preferable that the silicon-containing foreign material of 0.5 µm or more and 50 µm or less present on at least one paper surface is 2000 pieces/mm 2 or less, more preferably 1000 pieces/mm 2 or less, and 200 pieces/mm 2 or less It is more preferable, and it is especially preferable that it is 20 pieces/mm<2> or less. It is thought that there are also few silica foreign substances of 1 micrometer or more and 10 micrometers or less which become a problem, so that there are few silicon-containing foreign materials of 0.5 micrometer or more and 50 micrometers or less contained in paper.

Moreover, in the paper of this embodiment, it is preferable that the silicon-containing foreign material of 1 micrometer or more and 10 micrometers or less existing on the surface of at least one paper is 1000 pieces/mm<2> or less, It is more preferable that it is 100 pieces/mm<2> or less, 10 pieces/ It is more preferable that it is mm2 or less. It is thought that there are also few silica foreign substances of 1 micrometer or more and 10 micrometers or less, so that there are few silicon-containing foreign materials of 1 micrometer or more and 10 micrometers or less contained in paper.

Moreover, as for the paper of this embodiment, 100 pieces/mm<2> or less of the silica foreign material of 0.5 micrometer or more and 50 micrometers or less existing on at least one paper surface is preferable, 50 pieces/mm<2> or less is more preferable, and 20 pieces/mm<2> The following is more preferable, and 10 pieces/mm<2> or less is especially preferable. It is thought that there are also few silica foreign substances of 1 micrometer or more and 10 micrometers or less, so that there are few silica foreign substances of 0.5 micrometer or more and 50 micrometers or less contained in paper.

Moreover, as for the paper of this embodiment, 50 pieces/mm<2> or less of the silica foreign material of 1 micrometer or more and 10 micrometers or less existing on at least one paper surface is preferable, 30 pieces/mm<2> or less is more preferable, 10 pieces/mm<2> The following are more preferable, and 5 pieces/mm<2> or less is especially preferable. The silica foreign material transferred to a glass plate decreases, and it becomes difficult to generate|occur|produce problems, such as disconnection, so that there are few silica foreign substances of 1 micrometer or more and 10 micrometers or less.

(Speculative resistance)

Air permeation resistance is measured by the method based on JIS P8117. 5 second or more is preferable, as for air permeation resistance, 10 second or more is more preferable, 15 second or more is especially preferable. It is easy to remove only one sheet of paper from a glass plate package with a vacuum suction pad as air permeation resistance is 5 second or more. On the other hand, when air permeation resistance is less than 5 seconds, when it intends to remove paper from a glass plate package with a vacuum suction pad, it becomes easy to generate|occur|produce the abnormality that the glass plate under the paper to be removed is removed at the same time. Moreover, although the upper limit of air permeation resistance is not specifically limited, 50 second or less is preferable, 45 second or less is more preferable, and its 40 second or less is still more preferable.

(Characteristics of Laminate for Glass Plate)

The basis weight of the paper for glass plates is measured by the method based on JISP8118. Although the one with a smaller basis weight of paper is preferable since the mass at the time of conveyance becomes small, when it is too small, sufficient buffering property cannot be acquired. Therefore, 10 g/m<2> or more is preferable, as for the basis weight of paper, 20 g/m<2> or more is more preferable, and 30 g/m<2> or more is still more preferable. Moreover, since the mass at the time of conveyance becomes large when the basis weight of paper is too large, it is unpreferable. Therefore, 100 g/m<2> or less is preferable, as for the basis weight of paper, 90 g/m<2> or less is more preferable, and 80 g/m<2> or less is still more preferable.

The thickness of the paper is preferably 50 µm or more and 200 µm or less from the viewpoint of buffering properties. In addition, the density of the paper is preferably 0.30 g/cm 3 or more and 1.00 g/cm 3 or less.

(Glass plate laminate)

The glass plate laminated body 12 of this embodiment laminates|stacks the glass plate 14 of at least 2 or more sheets, and has the paper 16 for glass plates which concerns on this invention between adjacent glass plates.

(glass plate package)

The glass plate package 10 of this embodiment has the glass plate laminated body 12 and the pallet on which the glass plate laminated body 12 is mounted.

The pallet is a well-known pallet for packing a glass plate, and has a base 22, a ramp 18 provided on the upper surface of the base 22, and a mounting base 24 for supporting the end face of the glass plate laminate 12. . Although the angle (theta) of the mounting table 24 and the inclination stand 18 will not be specifically limited if the glass plate 14 can be mounted stably, 90 degrees is preferable.

The angle γ of the slope 18 is an angle between the slope 18 and the horizontal plane. That is, when the upper surface of the base on which the ramp 18 and the mounting base 24 are installed is horizontal as shown in FIG. 1 , the angle γ of the ramp 18 refers to the angle between the ramp 18 and the base 22 . . The closer the angle γ of the inclination band 18 is to 90°, the more space saving is achieved. In addition, as the slope 18 is made closer to 0°, the pressure applied to the glass plate 14 is dispersed, and defects such as notch in the end surface can be suppressed, but since a large space is required, the efficiency of storage and conveyance it falls In this specification, the angle of the slope 18 is called a pallet of 10 degrees or less of a flat pallet, and the pallet of more than 10 degrees is called a vertical pallet.

Although a flat pallet or a vertical pallet may be sufficient as the pallet to be used, in the case of a large glass plate, a big pressure is applied to the edge part of the glass plate 14 by the weight of the glass plate 14. Therefore, in the case of a large sized glass plate, it is preferable to use the pallet which mounts a glass plate in a flat state. Moreover, since the pressure applied to the end surface of the glass plate 14 becomes large so that the glass plate 14 is large, 0 degrees or more and 5 degrees or less are preferable, as for the angle of an inclination band, 0 degrees or more and 3 degrees or less are more preferable, 0 ° or more and 1 ° or less are more preferable. However, when storing in a truck, a container, etc. for transportation of the glass plate 14, it may not be accommodated with a flat pallet. Therefore, you may use a vertical pallet for space saving.

A large sized glass plate means, for example, a glass plate whose at least one side is 2400 mm or more, and, as a specific example, the glass plate of 2400 mm or more of long sides, and 2000 mm or more of short sides. The large glass plate is preferably a glass plate having at least one side of 2400 mm or more, for example, a glass plate having a long side of 2400 mm or more and a short side of 2100 mm or more, and a glass plate having at least one side of 3000 mm or more, for example, a long side of 3000 mm or more, A glass plate with a short side of 2800 mm or more is more preferable, a glass plate with at least one side of 3200 mm or more, for example, a glass plate with a long side of 3200 mm or more and a short side of 2900 mm or more, is still more preferable, and at least one side is a glass plate of 3300 mm or more, for example , a glass plate having a long side of 3300 mm or more and a short side of 2950 mm or more is particularly preferable.

As for the thickness of the glass plate 14, 1 mm or less is preferable. By making the glass plate 14 thin, weight reduction can be achieved. As for the thickness of the glass plate 14 of this invention, 0.75 mm or less is more preferable, 0.6 mm or less is still more preferable, 0.5 mm or less is especially preferable, Most preferably, it is 0.4 mm or less. The thickness may be 0.1 mm or less or 0.05 mm or less. However, 0.1 mm or more is preferable from a viewpoint of preventing dead weight bending, and, as for thickness, 0.2 mm or more is more preferable.

It is preferable to use the glass plate 14 for a display. Since there are few silica foreign substances of 1 micrometer or more and 10 micrometers or less which exist in the main surface of the glass plate 14, defects, such as disconnection, can be suppressed. As a display, it is preferable to use for the board|substrate of a liquid crystal display.

As mentioned above, although the paper 16 for glass plates, the glass plate laminated body 12, and the glass plate package 10 were demonstrated in detail, limitation is not carried out to the example mentioned above, The range which does not deviate from the summary of this invention It goes without saying that various improvements and changes may be made.

<Example>

Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by these. In the following, Examples 1 to 4 are Examples, and Examples 5 to 7 are comparative examples. In addition, about the case where there is no description in particular, the manufactured paper was measured, after performing a process according to JIS P8111.

The silicon concentration, magnesium concentration, and calcium concentration contained in the paper of Examples 1 to 7 were measured twice, respectively, using X-ray fluorescence analysis, and the average value was calculated. Next, the number of silicon-containing foreign substances with the longest diameter of 0.5 µm or more and 50 µm or less and 1 µm or more and 10 µm or less by scanning electron microscope and an energy dispersive X-ray analyzer installed in the scanning electron microscope (pieces/ mm 2 ), and the number of silica foreign substances (pieces/mm 2 ) having the longest diameter of 0.5 μm or more and 50 μm or less and 1 μm or more and 10 μm or less. The silicon-containing foreign material and the silica foreign material of each size were measured twice each using different paper, respectively, and the average value was computed.

The paper for glass plates of Examples 1 to 7 was molded into a size of 2330 mm × 1990 mm, each having a plate thickness of 0.5 mm, sandwiched between the glass plates for FPD of the size of 2250 mm × 1950 mm, a plurality of glass plates It was set as the laminated|stacked glass plate laminated body.

Each glass plate laminated body was mounted on the pallet of the vertical volume shown in FIG. 2 (600 sheets of glass plates), and the glass plate package was produced. The produced glass plate package was stored for 10 days.

From the glass plate package, the glass plate closest to the ramp of the pallet was taken out, and after washing the glass plate, the number of foreign substances remaining on the surface of the glass plate was measured with an optical inspection machine.

Each measurement was performed by the following method.

<Measurement of element concentration of paper for glass plate by fluorescence X-ray analysis>

The approximately central portion of the paper was measured using a fluorescence X-ray analyzer (manufactured by Rigaku Co., Ltd., model: ZXS PRIMUSII). Next, after measuring a reference sample whose concentration is known in advance for quantification of the detection element, the numerical value of each element was corrected from the X-ray intensity. The electric power at the time of measurement was set to 3000 W, and content of each element of magnesium, aluminum, silicon, and calcium was quantified.

<Measurement of the number of silicon-containing foreign substances and silica foreign substances contained in the paper for glass plate>

The silicon-containing foreign material contained in the paper is a scanning electron microscope (manufactured by Nippon Electronics Co., Ltd., model: JSM-6490LA) and an energy dispersive X-ray analyzer (manufactured by Oxford Instruments, Inc., model). :X-MAXN50) was used to measure the approximate center of the paper. The acceleration voltage at the time of observation was 20 kV.

When measuring silicon-containing foreign substances and silica foreign substances having the longest diameter of 0.5 µm or more and 50 µm or less, first, 100 areas of 0.1 mm × 0.1 mm are measured, and foreign substances other than carbon having the longest diameter of 0.5 µm or more counted. For each foreign material detected by this reflection electron detector, the size is calculated from the number of pixels, and the element is analyzed with an energy dispersive X-ray analyzer for each particle having the longest diameter of 0.5 µm or more and 50 µm or less, Among the elements other than carbon and oxygen, the number of particles containing 10 wt% or more of silicon (silicon-containing foreign matter) and particles containing 80 wt% or more of silicon (silica foreign material) were counted.

In addition, when measuring the silicon-containing foreign material and the silica foreign material whose longest diameter is 1 micrometer or more and 10 micrometers or less, it measured similarly.

<Measurement and evaluation of foreign matter remaining on the surface of the glass plate>

From the glass plate package stored for 10 days, take out the glass plate closest to the ramp of the pallet, wash the glass plate, and measure the number of foreign substances remaining on the surface of the glass plate with an optical inspection machine (manufactured by Hitachi High-Tech Fine Systems, Ltd., Format: GI). Washing of a glass plate was performed by spraying pure water and rubbing with a PVA sponge, conveying a glass plate in a horizontal direction.

Less than 50 foreign substances present on the surface of the glass plate were A, 50 or more and less than 60 B, and 60 or more C.

(Example 1, Example 2)

The raw material liquid of paper was obtained by diluting virgin pulp with a high calcium-containing concentration as a raw material with the groundwater filtered with the process filter of 200 micrometers of filtration precision. The raw material solution was expanded to a uniform thickness and dehydrated to obtain a wet paper. The obtained wet paper was dehydrated by pressing with a press roller, and the paper was obtained by drying the wet paper after pressing in an atmosphere of about 120°C.

(Example 3, Example 4)

It was manufactured in the same manner as in Example 1 except that virgin pulp having a high silicon-containing concentration was used as a raw material.

(Example 5)

It was manufactured in the same manner as in Example 1 except that virgin pulp having a high silicon-containing concentration and a low calcium-containing concentration was used as a raw material.

(Example 6, Example 7)

As a raw material, it was prepared in the same manner as in Example 1, except that virgin pulp containing talc and having a high concentration of silicon and magnesium was used.

<Result>

Table 1 shows the measurement results and evaluation results. According to Table 1, when the silicon concentration was 200 ppm or less and the X/Y ratio obtained by dividing the silicon concentration by the calcium concentration was 4.00 or less, the contamination was A or B. On the other hand, when the silicon concentration was more than 200 ppm and the X/Y ratio was greater than 4.00, the contamination properties were all C.

As a result, it can be understood that the silicon concentration and the X/Y ratio are related to the number of silicas present in the paper and the contamination properties of the glass plate.

10 … glass plate package
12 … glass plate laminate
14 … glass plate
16 … Laminate for glass plate
18 … ramp
22 … Expectation
24 … loading stand
42 … paper roll
100 … Manufacturing apparatus of laminate for glass plate
112 … head box
114 … wire part
116 … lower wire
118 … upper wire
120 … press part
124 … dryer parts
126 … calendar part
128 … reel
130 … jumbo roll
134 … cutter
136 … winder

Claims (11)

Cellulose pulp as the main component,
It is a paper for glass plates with a basis weight of 10 g/m2 or more and 100 g/m2 or less,
When the silicon concentration measured by the fluorescence X-ray analysis of the paper for glass plates is X and the calcium concentration is Y,
X is 200 ppm or less,
Paper for glass plates, characterized in that the X/Y ratio, which is a value obtained by dividing the silicon concentration by the calcium concentration, is 4.00 or less. The method of claim 1,
The glass plate paper, when the magnesium concentration measured by fluorescence X-ray analysis is Z, the value obtained by dividing the silicon concentration by the magnesium concentration X/Z ratio is 3.00 or less. 3. The method of claim 2,
The Z is 20ppm or more, 100ppm or less of the glass plate paper. 4. The method according to any one of claims 1 to 3,
The Y is 20ppm or more, 400ppm or less of the paper for glass plates. 5. The method according to any one of claims 1 to 4,
The number of silicon-containing foreign substances of 0.5 µm or more and 50 µm or less present on the surface of at least one of the paper for glass plates is 2000 pieces/mm2 or less of the paper for glass plates. 6. The method according to any one of claims 1 to 5,
The number of silicon-containing foreign substances of 1 µm or more and 10 µm or less present in the at least one surface of the paper for glass plates is 1000 pieces/mm 2 or less, paper for glass plates. 7. The method according to any one of claims 1 to 6,
The said paper for glass plates, the number of the silica foreign material of 0.5 micrometer or more and 50 micrometers or less which exists on at least one paper surface is 100 pieces/mm<2> or less paper for glass plates. 8. The method according to any one of claims 1 to 7,
The said paper for glass plates is 50 pieces/mm<2> or less of the number of the silica foreign materials of 1 micrometer or more and 10 micrometers or less which exist in at least one paper surface. 9. The method according to any one of claims 1 to 8,
The glass plate laminate has an air permeation resistance of 5 seconds or more. It is a glass plate laminate in which at least two or more glass plates are laminated,
The glass plate laminated body which has the paper for glass plates in any one of Claims 1-9 between adjacent glass plates. A glass plate package provided with the glass plate laminated body of Claim 10, and the pallet which mounts the said glass plate laminated body.

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