JP4984060B2 - Paper quality control method and method for producing slip sheet for storage and / or transport slip of glass substrate for flat panel display - Google Patents

Description

  The present invention relates to a paper quality control method and a method for producing a slip sheet for storing and / or transporting a glass substrate for a flat panel display, and for flat panel display (hereinafter also referred to as FPD (Flat Panel Display)). A paper quality control method for selecting and using a suitable interleaving paper interposed between the glass substrates when storing and transporting the glass substrates, and a glass substrate for flat panel display. The present invention relates to a method for producing paper and / or interleaving paper.

  Glass substrates for FPD, such as glass substrates for plasma displays and glass substrates for liquid crystals, are susceptible to product defects due to scratches and contamination on the surface during storage and / or transportation. In particular, when used as a glass substrate that incorporates an electric circuit or the like on its surface, such as a non-alkali glass substrate used for a liquid crystal display, even if there are slight scratches or contamination on the surface, disconnection or poor patterning may occur. appear. Therefore, such a glass substrate is required to have extremely high surface characteristics.

  Scratches on the surface of a glass substrate often occur due to deviation between adjacent glass substrates when the glass substrates are stacked and stored or transported. Further, the contamination of the glass substrate surface often occurs when organic substances in the transport atmosphere adhere to the glass substrate surface. This organic matter (contaminant) is difficult to remove from the surface of the glass substrate only by washing with water. For example, it is necessary to wash with an acid or an alkali. Waste liquid treatment costs also increase, and it is difficult to completely remove organic substances from the glass substrate surface even if such cleaning is performed.

  Therefore, as a method for preventing scratches or contamination during storage or transportation of glass substrates, a method of interposing so-called interleaving papers, in which paper is sandwiched between laminated glass substrates and the surfaces of adjacent glass substrates are separated, has been conventionally used. It is taken.

  However, in the method of interposing the interleaving paper, since the interleaving paper is in direct contact with the surface of the glass substrate, there is a problem that the resin component of the interleaving paper is transferred to the glass substrate surface and contaminates the glass substrate surface. In order to avoid this, currently methods such as using slip sheets with low resin component content are used, but it is practically extremely difficult to precisely control the amount of resin component transferred from slip sheets. In addition, such slip sheets are more expensive than plain paper, and this is a factor in increasing costs.

  Therefore, a glass substrate slip sheet as exemplified below has been proposed.

  Patent Document 1 describes a glass slip sheet containing 0.1% by weight or more of sodium tripolyphosphate. And, by using this slip sheet, it is stated that effects such as water repellency on the glass surface and avoiding paper traces can be obtained without strictly controlling the properties of the slip sheet as in the past. Has been.

Patent Document 2 describes a slip sheet for glass interposed between glass substrates and containing 50 mg / m ² or more of sodium tetraborate. And the traces of the paper skin appearing on the glass substrate surface due to adhesion of water vapor etc. are presumed to be due to transfer unevenness of the resin component from the interleaf paper or its hydrolyzate fatty acid sodium, etc. The effect of facilitating removal of these water-repellent sources by washing is described.
JP-A-6-316432 Japanese Patent Laid-Open No. 7-101483

  However, even when the glass substrate is stored and transported using conventional slip sheets as described in Patent Documents 1 and 2, slight scratches may occur on the glass substrate surface.

  When a glass substrate with even slight scratches is used as a glass substrate in which an electric circuit or the like is incorporated on the surface, such as a liquid crystal display, a disconnection or a patterning defect occurs in the electric circuit. Since malfunction may occur in a liquid crystal display etc., it is not preferable.

  As described above, various applications have been filed regarding interleaving paper that does not cause scratches on the glass substrate. However, the problem is that when the glass substrate is used as interleaving paper for storage and / or transportation, it is scratched. It is important from the viewpoint of preventing the occurrence of scratches to distinguish and manage slip sheets that do not generate scratches and slip sheets that generate scratches during manufacturing. However, there has been no proposal related to a slip sheet management method for preventing the occurrence of scratches.

  The present invention has been made in view of such circumstances, and when used as a glass substrate storage slip and / or transport slip, a good slip sheet that does not cause scratches on the glass substrate, Paper quality control method capable of discriminating and managing the interleaving paper that generates the ink during production, and selecting and using the good interleaving paper, and the interleaving paper for storing and / or transporting the glass substrate for the flat panel display An object of the present invention is to provide a method for producing a slip sheet.

  The inventor of the present application examined the cause of scratches caused by the slip sheet on the surface of the glass substrate when the slip sheet was interposed between the glass substrates. The cause of the scratch was found to be correlated with the size of the foreign material contained in the slip sheet, and if the slip sheet contained foreign material of a predetermined size or less, the scratch problem was solved. It was confirmed by experiment. It was also confirmed that the foreign matter was fine gravel, minerals, etc. contained in water (well water, groundwater, river) used for diluting pulp, which is a raw material for paper. That is, it was confirmed that the quality of the slip sheet was different depending on the quality of the water collected at that time.

Therefore, in the paper making process of manufacturing paper process, collect part of the manufactured paper, check the size of the foreign matter contained in the paper and the collected paper manufactured through the paper making process, the foreign substance magnitude predetermined size, or that it segregated based on exceeding a predetermined magnitude.

In papermaking process, collect part of the manufactured paper (wet paper), the size of the foreign matter contained in the collected papers examined by measuring means, on the basis of the inspection results, via the paper making process The manufactured paper is classified according to quality, that is, with respect to foreign matters, with a specific size as a threshold value. Thus, according to the present invention, when used as a storage slip and / or a transport slip for a glass substrate, a good slip sheet that does not cause scratches on the glass substrate and a slip sheet that generates scratches are provided. It becomes possible to discriminate and manage at the time of manufacture. Paper collected for foreign matter inspection is reused as raw material, but foreign matter inspection can be continuously monitored in the process of returning to raw material. This does not affect the paper production efficiency.
In order to achieve the above object, the present invention provides a storage slip and / or transport slip for a glass substrate for a flat panel display in which the size of a foreign substance contained in the slip is 200 μm or less. In the paper making process, the ears of the manufactured paper are collected, the size of the foreign matter contained in the collected ears is inspected, and the paper manufactured through the paper making step is measured with a size of the foreign matter of 200 μm. Provided is a paper quality control method characterized in that separation management is performed based on the following.
In the slip sheet, in the paper making process of the paper making process, the ear of the manufactured paper is collected, the size of the foreign matter contained in the collected ear is inspected, and the paper manufactured through the paper making process Is preferably separated and managed on the basis that the size of the foreign matter is 200 μm or less.

  In JP-A-2003-213585, a video camera and a light emitting device are arranged opposite to each other across a running line of wet paper (paper) that runs in contact with a wire of a paper machine, and wet paper is removed by the video camera. Capture as a static two-dimensional image, process this static two-dimensional image with an image processing device, and remove the low-frequency noise component of grayscale fluctuation and the periodic high-frequency noise component of grayscale fluctuation to improve the quality of wet paper ( A quality control method for analyzing foreign matter) has been proposed. However, since this quality control method performs analysis based on the moving wet paper, it can be analyzed if it is in the ground, but it is possible to analyze even the size of minute foreign matter that scratches the glass substrate. Difficult and impractical.

The present invention is characterized in that the inspection is a method in which the collected paper is immersed in water or a paper raw material liquid, the paper is returned to the raw material to separate foreign matter, and the size of the separated foreign matter is measured by a measuring means. And

Foreign matter inspection how the present invention is collected paper is immersed in water or paper raw material liquid foreign matter was separated by returning the paper feed, checking means the size of the separated foreign matters, for example, is measured with a microscope. For example, when the collected paper is put into a container and immersed in water or a paper raw material liquid, the paper is returned to the raw material and overflowed from the container, the foreign matter settles from the weight to the bottom of the container. When draining water from the container, foreign matters can be collected through the filter by passing through the filter, and in this state, inspection can be performed with a microscope. Thereby, the magnitude | size of a foreign material can be measured reliably.

The present invention provides a method for producing a slip sheet for storage of a glass substrate for a flat panel display and / or a transport slip sheet, which is quality-controlled by the paper quality control method.

According to the present invention, when used as a slip sheet for storing and / or transporting a glass substrate for FPD, a slip sheet in which the size of foreign matter contained in the paper exceeds a predetermined size is a glass substrate. Based on the experimental result of generating scratches on the paper, the paper in which the size of the foreign matter contained in the collected paper is equal to or smaller than a predetermined size is used as a storage slip and / or a transport slip for the glass substrate for FPD. to manage. This makes it possible to discriminate and manage a slip sheet that does not generate a scratch and a slip sheet that generates a scratch when used as a storage slip and / or a transport slip for an FPD glass substrate. It is possible to prevent the occurrence of scratches by selectively using the former slip sheet .

  According to the quality control method for paper of the present invention and the method for producing a slip sheet for storing a glass substrate for flat panel display and / or a method for manufacturing a slip sheet for transport, as a slip sheet for storing a glass substrate and / or a slip sheet for transport When used, a good slip sheet that does not cause scratches on the glass substrate and a slip sheet that generates scratches can be discriminated and managed at the time of manufacture, and the good slip sheet can be selected and used.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a paper quality control method according to the present invention and a method for producing a storage slip and / or a transport slip for a glass substrate for flat panel display will be described in detail below with reference to the accompanying drawings.

  1 and 2 show the configuration of a paper machine 10 of the paper making apparatus. As shown in FIG. 1, the paper raw material liquid (liquid obtained by diluting pulp with water) blown out from the head box 12 is supplied to the lower wire 16 installed in the wire part 14, and then the lower wire 16 and the upper wire By being sandwiched by 18, it is dehydrated and becomes wet paper (paper). A water jet nozzle (not shown) that cuts the wet paper ear P from the wet paper main body is disposed above the lower wire 16, and the wet paper ear P cut by the water jet nozzle includes: Used as an inspection sample for quality control of paper manufactured in this lot. The paper quality control method will be described later.

  The lower wire 16 and the upper wire 18 of the wire part 14 are permeable membranes formed endlessly, and are a net made of plastic or metal material, or a felt made of natural fiber or synthetic fiber. The lower wire 16 and the upper wire 18 are looped over a plurality of rollers to form a closed pool, and move around at a predetermined speed by transmitting the power of a motor (not shown) to a driving roller among the plurality of rollers. Has been.

  The dehydrated wet paper is conveyed to a press part 20 constituted by a roll and a blanket, where further dehydration and pressing are performed simultaneously. The wet paper that has passed through the press part 20 is conveyed to a dryer part 22 constituted by a plurality of rollers, and is dried in an atmosphere of about 120 ° C. while passing through the dryer part 22. The paper that has passed through the dryer part 22 and dried is conveyed to the coater part 24 of FIG. 2 and coated on the front and back surfaces of the paper, and then transported to the calendar part 26, where the front and back surfaces of the paper are smoothed. Is done. The smoothed paper is wound on a reel 28, and the rolled paper is subdivided into rolls 32, 32 of a predetermined width by a winder 30, and cut into rectangular paper 36 of a predetermined size by a cutter 34. The This rectangular paper 36 is used as a storage slip for the glass substrate and / or a transport slip.

  Here, the paper making process by the paper machine 10 includes all the processes from the wet paper process by the wire part 14 to the cutting process by the cutter 34 as described above, and the measuring process for measuring the size of the foreign matter contained in the paper is as described above. It is performed during the paper making process. This measurement process will be described later.

  FIG. 3 is a side view (schematic diagram) showing an example of a packing form in which glass substrates G are stacked and stored and / or transported.

  The packaging pallet 40 shown in FIG. 3 is composed of a base 42 and an inclined base 44 erected on the base 42, and a plurality of glass substrates G lean against the inclined surface of the inclined base 44. In addition, a slip sheet (rectangular paper) 36 is interposed between the glass substrates G.

  Next, a paper quality control method for selecting and using good paper as the interleaf paper 36 for the FPD glass substrate will be described. In this embodiment, a paper quality control method for selecting and using good paper as an interleaf for an FPD glass substrate will be described. However, the target glass of the present invention is not limited to an FPD substrate, and occurs during storage and transportation. It can be applied to any glass where scratches are a problem.

  The basic paper quality control method is to cut the paper ear P manufactured by the paper machine 10 with a water jet nozzle and collect it, and inspect and measure the size of the foreign matter contained in the ear P. The paper 36 manufactured through the paper machine 10 is managed according to the quality based on the measurement result of the foreign matter. That is, when the size of the foreign matter contained in the ear portion P is measured and used for storage and / or transportation of the glass substrate for FPD, the specific size of the foreign matter that causes scratches on the glass substrate G is measured. As the threshold, the paper 36 is sorted and managed for each lot.

  In addition, as an example of the separation management method, a plurality of ears P are collected within a predetermined set time, and the foreign matters contained in these ears P are measured. As a result, foreign matters exceeding a specific size are detected. In this case, there is a method in which the paper that has passed through the paper machine 10 within the set time is separated and managed as other paper (good slip paper that does not cause scratches on the glass substrate G) as slip paper that generates scratches. In addition, the process of measuring the magnitude | size of the foreign material contained in the ear | edge part P is the above-mentioned measurement process.

  According to this paper quality control method, when used for storage and / or transportation of glass substrates for FPD, a good slip sheet that does not cause scratches on the glass substrate G and a slip sheet that generates scratches are produced. It becomes possible to distinguish and manage at times.

  Explaining the method for inspecting foreign matter, the collected ear P is immersed in water or a paper raw material liquid, the ear P is returned to the paper raw material, the foreign matter is separated, and the size of the separated foreign matter is measured with a microscope (measuring means) ) To inspect and measure. Specifically, as shown in FIG. 1, the collected ear portion P is put into a container 50, immersed in water or paper raw material liquid 52, returned to the raw material, and overflowed from the container 50. On the other hand, the foreign matter is separated from the paper and settles to the bottom of the container 50 from its weight. If the filter 54 is laid in advance at the bottom of the container 50, foreign matter can be collected through the filter 54 by passing the filter 54 when the water 52 is discharged from the container 50. In this state, the microscope Inspect and measure according to 56. Thereby, the magnitude | size of a foreign material can be measured reliably.

  In the present embodiment, it was confirmed by experiment that the threshold value described above, that is, the threshold value of a specific size of a foreign substance that causes scratches on the glass substrate G was 200 μm. Therefore, a paper having a size of the foreign matter contained in the collected ear portion P of 200 μm or less can be used as a slip sheet for transporting the glass substrate G for FPD. Managed every time. Therefore, by selectively using the managed slip sheet, it is possible to prevent the glass substrate G from being damaged. In addition, the thickness of the interleaving paper manufactured by this Embodiment is 0.06-0.1 mm, and the glass substrate G for FPD used the brand name AN100 and Asahi Glass Co., Ltd. product.

  In the embodiment, the threshold is set to 200 μm. However, when the thickness of the slip sheet is reduced or the composition of the glass is changed, it is necessary to determine the threshold by experiment. For example, the slip sheet needs to have the same size (1500 mm × 1800 mm) as the size of the glass substrate G for FPD of the sixth generation size, and the quality-controlled paper can be manufactured by the method of the present invention. For example, a thickness of about 0.01 to 0.2 mm can be manufactured. The paper raw material may be waste paper, virgin pulp, or a mixture thereof. Furthermore, a raw material containing cellulose or the like may be used.

Explanatory drawing showing the configuration on the front side of the configuration of the paper machine Explanatory drawing showing the configuration of the latter stage of the configuration of the paper machine Side view of a pallet showing an example of the packaging form of a glass substrate for FPD

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Paper machine, 12 ... Head box, 14 ... Wire part, 16 ... Lower wire, 18 ... Upper wire, 20 ... Press part, 22 ... Dryer part, 24 ... Coater part, 26 ... Calendar part, 28 ... Reel, 30 ... Winder, 32 ... Roll, 34 ... Cutter, 36 ... Rectangular paper, 40 ... Packing pallet, 42 ... Base, 44 ... Inclined base, 50 ... Container, 52 ... Water or paper raw material liquid, 54 ... Filter, 56 ... Microscope, 58 ... Cyclone

Claims (3)

The slip sheet for storage and / or transport of the glass substrate for a flat panel display in which the size of the foreign matter contained in the slip sheet is 200 μm or less is used in the paper making process of the paper making process. Collecting, inspecting the size of the foreign matter contained in the collected ear, and separating and managing the paper manufactured through the paper making process based on the size of the foreign matter being 200 μm or less. Characteristic paper quality control method.   2. The paper according to claim 1, wherein the inspection is a method in which the collected paper is immersed in water or a paper raw material liquid, the paper is returned to the raw material to separate foreign matter, and the size of the separated foreign matter is measured by a measuring unit. Quality control method.   A method for producing a slip sheet for storage and / or conveyance slip for a glass substrate for a flat panel display, the quality of which is controlled by the paper quality control method according to claim 1.

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