KR20040089617A - Glass substrate package - Google Patents

Abstract

The present invention relates to a glass substrate package (1) for wrapping and sealing a glass substrate (2) by folding a film such as a PET film (3) that does not contaminate the surface of the glass substrate (2), the glass substrate (2) Inserted into the folded portion of PET film 3 and heat-sealed three sides of the folded portion of PET film while forming air-sealed portions 4 and 5 while pressing air out of the folded portion. The package can achieve high efficiency in transport light storage of glass substrates (especially glass substrates used for LCDs, etc.) and at the same time chemical cleaning process using specific detergents performed after unpacking and before processing each glass substrate. Eliminates the need for

Description

Glass substrate package

In order to obtain a high quality display device such as a liquid crystal display (LCD), one of the most important considerations is that scratches and dirt on the surface of the glass substrate used as the display device should be removed as far as possible during transportation and storage.

In order to solve the above-mentioned problems, several practical methods exist for transporting and storing the glass substrates. Such methods include using a container provided with a plurality of grooves for inserting each glass substrate, and stacking a plurality of glass substrates that are each protected through a frame. The methods provide that a gap filled with clean air is provided between each adjacent glass substrate. Thus, scratches due to friction between adjacent glass substrates can be prevented and at the same time contamination by external sources of external atmosphere can be reduced.

However, the methods of providing a gap between each glass substrate significantly limit the number of glass substrates that can be stored in a space of a predetermined size (ie stacking efficiency), and thus the transport and storage efficiency of the glass substrate. This is limited.

In order to improve the stacking efficiency of the glass substrate during transportation and storage of the glass substrate, there are other practical ways of stacking multiple glass substrates and paper sheets alternately. However, this method creates a problem called "surface yellowing" due to the chemical reaction between the paper sheet and the moisture in the atmosphere. In addition, since the edge face of the glass is exposed to the outside atmosphere, contamination of each edge of the glass substrate cannot be removed by the above method.

In order to solve the surface sulfiding problem, a method of stacking a plurality of glass substrates with a coating film such as polyethylene film attached to both surfaces of each glass substrate was also used. When stacking the coated glass substrate, a paper sheet may be additionally inserted between the films to prevent the films from sticking together.

However, the method of using the film caused another problem. That is, even after the film was removed, the remaining film remained on the glass substrate surface. Because of the residue, it was essential to clean each glass substrate through chemical cleaning with a detergent or the like after unpacking the glass substrate and before processing it into a product. Such a chemical cleaning process using a detergent, etc. required a lot of time and cost, and thus became a decisive factor limiting the production efficiency of products such as LCD.

In addition, the method using the coating film did not solve the problem of contamination of the edge face. In addition, when additionally the paper sheet was used, the contamination due to the paper sheet could also not be completely removed.

On the other hand, Japanese Patent Laid-Open No. 11-1205 discloses a bag-like glass substrate package for completely packaging a single glass substrate. During transportation, a plurality of glass substrates, each packaged in this manner, are stacked in a container.

Here, the bag-like package is made of a conventional laminated film consisting of alumina sheets sandwiched between pairs of polyethylene films.

Since the package disclosed in Japanese Patent Laid-Open No. 11-1205 covers the entire surface of the glass substrate including the edge surface, the inner surface of the film is intentionally formed in a manner similar to the above-described method of coating both sides of the glass substrate with a film. It is not necessary to adhere to the surface to further prevent contact between the outside air and the glass substrate. However, there is a possibility that more undesirable adhesion occurs between the inner surface of the film and the glass substrate surface, in particular stacking a number of packaged glass substrates in a container causes the film to be pressed against the glass substrate surface. That is, Japanese Patent Application Laid-Open No. 11-1205 did not eliminate the possibility of residues present on the surface of the glass substrate after unpacking, thus requiring a costly and expensive chemical cleaning process. In this respect, Japanese Patent Laid-Open No. 11-1205 applies a technique of treating the inner surface of the film with a nonuniform surface having fine protrusions so that the contact surface between the film and the glass substrate surface is reduced. This may reduce the residue to some extent but does not completely eliminate the need for chemical cleaning processes using detergents or the like.

In addition, in the case of the package covering the entire surface of the glass substrate including the edge surface as in the case of Japanese Patent Application Laid-Open No. 11-1205, air in each package inner volume is used for several purposes including the improvement of transportation and storage efficiency. It is desirable to remove. However, if the film requires a chemical cleaning process, air removal from the package interior volume is undesirable because the film adheres firmly to the glass substrate surface, further increasing the residue. This further increases the cost and time required for the chemical cleaning process.

Summary of the Invention

I. Problem solving by the present invention

As mentioned above, conventional techniques in which no gap is provided between adjacent glass substrates are costly and time consuming using at least one surface sulfation problem (1) and detergents or the like that significantly limit the production efficiency of LCDs and the like. Phosphorus chemical cleaning process problem (2).

It is therefore an object of the present invention to provide an improved glass substrate package that can overcome all the above-mentioned problems of the prior art. In other words, the present invention has a high stacking efficiency (i.e., high efficiency in transportation and storage), and at the same time eliminates the costly and time-consuming chemical cleaning process performed after surface sulfiding and unpacking and before processing the glass substrate. can do.

II. How to solve the problem

The glass substrate package according to the present invention is a package wrapped and sealed with a film that does not contaminate the glass substrate surface. The said glass substrate is a glass substrate for liquid crystal displays normally.

In the present invention, a polyethylene terephthalate film is usually used as a film which does not contaminate the glass substrate surface.

Laminated films can also be used as films that do not contaminate the glass substrate surface. In this case, the innermost layer of the layers constituting the laminated film is a polyethylene terephthalate layer. In addition, at least one layer constituting the laminated film has moisture resistance. In this case, the aluminum layer, not the inner layer, may serve as the moisture resistant layer.

It is also desirable to remove air from the internal volume of the glass substrate package according to the present invention.

In the present invention, the film that does not "contaminate" the surface of the glass substrate is (1) even if a plurality of packages are stacked and the film is pressed on the glass substrate surface, no residual film remains on the glass substrate surface or only through a physical cleaning process Means a very small amount of residue that can be removed, and (2) means that there is no deleterious effect on the glass substrate surface (eg, chemical reaction of the film material) that requires a chemical cleaning process on the glass substrate.

By "physical cleaning process" is meant a cleaning process that does not require the use of a special detergent or formulation, for example a cleaning process or an ultrasonic cleaning process using only water spray. On the other hand, the "chemical cleaning process" means a cleaning process that requires the use of a special detergent or formulation.

In addition, the "polyethylene terephthalate film / layer" of the present invention may contain a small amount of impurities as long as it is called "polyethylene terephthalate film / layer (PET film / layer) in an industrial sense.

In addition, the "laminated film" of the present invention is strictly meant to be not only a laminated film made through a lamination process, but also all other types of layers including a film made through a vapor deposition process, in which a layer made of two or more materials are laminated. It means a film made. The "aluminum layer" of the present invention also includes an aluminum deposition layer.

III. Preferred Effects of the Invention

Since the glass substrate package according to the present invention wraps and seals the glass substrate with a film that does not contaminate the glass substrate surface, it eliminates the costly and time-consuming cleaning process issues performed after surface-sulfurization and unpacking and before glass substrate processing. All can be solved, and stacking multiple packages directly results in high efficiency for transportation and storage of glass substrates. Thus, glass substrates packaged with the glass substrate package according to the present invention only require a physical cleaning process after unpacking and before processing. This can significantly reduce the time and cost required for the cleaning process at lower levels in essential chemical cleaning processes. This desirable effect is particularly important for glass substrates for liquid crystal displays, which particularly require special attention to surface scratches and dirt removal.

The effect of preventing contamination of the glass substrate surface can be further enhanced by using a laminated film as the package film of the present invention and providing moisture resistance to at least one layer composed of the laminated film. This further reduces the time and cost required for the cleaning process.

In addition, a package according to the invention that uses a film that does not contaminate the glass substrate surface can vacuum-pack the glass substrate (ie, package while removing air from the package internal volume). This is because the film used in the package does not remain on the surface of the glass substrate, even if the film is strongly pressed onto the surface, there is no residue left to be removed through the chemical cleaning process. As such vacuum-packing further improves the stacking efficiency, ie the transport and storage efficiency of the glass substrate. In addition, when vacuum-packing is applied, undesirable movement of the glass substrate in the package can be prevented. This prevents scratches due to frictional effects between adjacent glass substrates that cannot be completely blocked by the film.

The present invention relates to a package in which a glass substrate is packaged in a film and sealed, and more particularly, to a package in which a glass substrate used in a liquid crystal display or the like packed and sealed in a film is packaged and sealed in a film. .

1 is a front view of a glass substrate package according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an exemplary process of each step for manufacturing the package shown in FIG. 1.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 shows a glass substrate package 1 according to one embodiment of the invention. In the glass substrate package 1, the glass substrate 2 was packaged and sealed with the polyethylene terephthalate film 3 (henceforth "PET film 3"). In FIG. 1, the PET film 3 is folded at the lower edge of the glass substrate package 1. Heat-sealed portions 4 and 5 are provided at the left and right edges and the upper edge proximal ends of the glass substrate package 1, respectively. It is desirable to remove air from the interior volume of the glass substrate package 1.

FIG. 2 is a diagram exemplarily illustrating steps of a process of manufacturing the glass substrate package 1 shown in FIG. 1.

First, in step 2A, the glass substrate 2 is inserted into the folded end of the PET film 3 in a long and continuous form. Here, a heat-sealable material was applied to the inner surface of the band-like portion 4 'near the left and right edges of the PET film 3 through a lamination process. Similarly, the heat-sealing material was also applied to the inner surface of the horizontal band-like portion 5 'via a lamination process. The horizontal band-like portions 5 'are arranged at predetermined intervals so that the positions of two adjacent horizontal band-like portions 5' coincide when the PET film 3 is folded.

In step 2B, a roller 6 having a pair of heating rollers 7 on the opposite side rotates in the folded portion of the PET film 3 into which the glass substrate 2 is inserted. The roller 6 forms a heat-sealed portion 4 while heat-sealing the band-like portion 4 'to press air out of the folded portion of the PET film 3.

In step 2C, a heat-sealed portion 5 is formed by heat-sealing a band-like portion 5 'where the heat-sealing bar 8 is locally-matched. Packaging and sealing the glass substrate 2 in the PET film 3 folded in this step is completed. Here, instead of performing the steps of FIG. 2C, the band-like portion 5 'may be temporarily sealed, leaving the unsealed portion first, followed by removal of air from the internal volume of the folded portion and complete sealing. . This further improves the degree of air removal in the volume inside the glass substrate package 1.

Finally, in the step of FIG. 2D, the formed glass substrate package 1 is cut from the remaining portion of the PET film 3 in a long continuous form. Then, in one embodiment, the process returns to the first step shown in FIG. 2A to form a number of similar packages in succession.

As the PET film 3 used in the above-described embodiment does not contaminate the surface of the glass substrate 2, the level of cleaning process required for each glass substrate after unpacking and before processing is very low, such as the level of physical cleaning process. Also, it has high efficiency in transportation and storage of glass substrates. The stacking efficiency (ie transport and storage efficiency) of the package 1 may be further improved if the degree of air removal of the internal volume is improved. In addition, an improvement in the degree of air removal prevents undesired movement of the glass substrate 2 in the package 1 and, therefore, the frictional force between adjacent glass substrates 2 that cannot be completely blocked by the PET film 3. By this, each glass substrate 2 can be prevented from being scratched.

In the above-described embodiment, the heat-sealing material is applied to the band-like portion of the inner surface of the PET film 3 by using a heat-sealing technique to package and seal the glass substrate 2, but as in the method of using a double-sided tape. Alternative methods may be used.

In an alternative method of the embodiment described above, a laminated film may be used instead of the PET film 3. Similar to the PET film 3, the laminated film is a film that does not contaminate the surface of the glass substrate 2. Moreover, it is preferable that at least one layer which comprises the said laminated | multilayer film has moisture resistance.

For example, the laminated film described above may be a film laminated in this order through a lamination process consisting of a protective layer such as a PET layer, an aluminum layer, and a polypropylene layer facing the glass substrate 2. In this example, the aluminum layer having moisture resistance can further prevent the surface of the glass substrate 2 from being contaminated. In addition, in the above example, the degree of cleaning process required for each glass substrate after unpacking and before processing can be as low as the level of physical cleaning process, indicating high efficiency in the transportation and storage of glass substrates. In addition, the same effects as described above can be obtained even when the air removal is improved.

Here, the vapor deposition process can be used instead of the lamination process to provide the aluminum layer described above.

In one embodiment described above, the PET film was used as an example of a conventional film that does not contaminate the surface of the glass substrate.

Now, experimental results that demonstrate the effectiveness of PET films with films that do not contaminate the surface of glass substrates are described.

The experiment was performed with eight commercially available films.

The experiment was carried out through the following process.

First, nine samples were prepared for each of the eight films. Each sample was prepared by attaching a piece of film to a portion of one side of the glass substrate. Three of the nine samples were stored for one day at room temperature, the other three samples were kept for one hour at a temperature of 60 ° C., and the other three samples were kept for one day at a temperature of 60 ° C. The film was then removed from each sample. Next, steam was applied to the entire surface of the glass substrate of each sample, and the vapor state was visually observed and compared at the portion where the film was attached and the portion where the film was not attached. According to visual observation of the marking of the film, the degree of surface contamination of the portion to which the film was attached was evaluated at a sixth grade (ie, the A-F grade described below).

Next, one of each of the three glass substrates was maintained under the same conditions as in the above-mentioned steps and washed in pure water at 50 ° C. through an ultrasonic cleaning process for 4 minutes, rinsed and dried (condition “I”). The other of the three glass substrates was washed, rinsed and dried in a conventional 50 ° C. alkaline detergent used to clean the glass substrates via an ultrasonic cleaning process for 4 minutes (condition “II”). The other was washed with ultrasonic cleaning for 1 minute with the same alkaline detergent at 50 ° C. above, rinsed and dried (condition “III”). Then, the degree of surface contamination of each of the glass substrates was evaluated by the above-described grade 6 (ie A-F). The grade was determined according to the following criteria.

A: No film marking was observed at all;

B: Weak signs are observed when observed with great care;

C: Film contour that is rarely observed.

D: film contour is clearly observed when viewed from the opposite side of the glass substrate;

E: Film contour is clearly observed on both sides of the glass substrate;

F: The whole film display is clearly observed on both surfaces of a glass substrate.

In addition, in the following Table 1, grade B 'means between grades B and C.

The experimental results are summarized in Table 1 below, and the specific films tested are shown in Table 2 below.

As shown in Table 1 below, each of the samples 1-3 with PET film attached had only a very few film residues corresponding to at least Grade B 'before washing (ie, immediately after removing the film). After physical washing without detergent (corresponding to condition "I"), the grades of each of Samples 1-3 improved to Grade A. This result clearly shows the efficiency of PET film as a film that does not contaminate the glass substrate surface.

On the other hand, each of Samples 6 and 7, polyethylene film samples, which have been commonly used for surface protection of glass substrates until now, exhibited a very large film residue corresponding to Grade E before cleaning (ie, immediately after film removal). In addition, even after a chemical cleaning process under defined conditions (ie, conditions "II" or "III"), the grade was improved up to grade C only. Of course, the condition worsens when a physical cleaning process is applied. Thus, glass substrates wrapped with polyethylene films require a longer chemical cleaning process to achieve the level required for the use of the substrate for making LCDs or the like, where surface clearness of glass substrates is particularly important. This undesirably increases the time and cost required for the cleaning process and thus significantly limits the production efficiency of the final product, such as an LCD. The same applies to the polyolefin film used in Sample 8.

In the bi-axial polypropylene film used for Samples 4 and 5, surface clarity as good as PET film was obtained in the film of Sample 4. However, the film of Sample 5 only had the same level of surface clarity as the polyethylene film and the polyolefin film.

As described above, the experimental results demonstrated the efficiency of the PET film as a film that does not contaminate the surface of the glass substrate. In addition, as described above, the laminated film having a PET layer as an inner layer that can be used alternatively also proved to be effective according to the above results.

The present invention has been described in detail through one preferred embodiment and another embodiment. The above embodiments are merely representative examples. In other words, the scope of the invention is defined based on the claims set out below.

Sample number matter surface Room temperature, 1 day aging, 60 ° C, 1 hour aging 60 ° C, 1 day aging I Ⅱ Ⅲ I Ⅱ Ⅲ I Ⅱ Ⅲ One PET Face A face B B → AB → A A → AA → A A → AA → A B → AB → A B → AB → A B → AA → A B '→ AB' → A B → AB → A B → AB → A 2 PET Face A face B B → AB → A B → AA → A A → AB → A B → AB → A A → AA → A A → AB → A B '→ AB → A B → AB → A B → AB → A 3 PET B → A B → A B → A B → A B → A A → A B '→ A B → A B → A 4 OPP B → A A → A A → A B → A A → A B → B B '→ A C → A B → A 5 OPP Face A face B E → D-- D → B-- D → B-- F → F-- F → D-- F → D-- F → F-- F → E-- F → E-- 6 Polyethylene E → D E → C E → C E → E E → D E → D E → E E → E E → E 7 Polyethylene E → E E → D E → C E → E E → E E → C E → D E → E E → D 8 Polyolefin E → E E → B E → C E → E F → D F → D F → F F → E F → D

Sample number matter Surface finish Seller Product name (film) One PET Face A: Corona discharge finish Face B: None Futamura Kagaku Kogyo FE2001 # 12 2 PET Face A: Corona discharge finish Face B: None Toyobooseki E5100 3 PET Torrey Lumirror T60 4 OPP (biaxial-oriented polypropylene film) Toyobooseki P2002 5 OPP (biaxial-oriented polypropylene film) Face A: Corona discharge finish Face B: None Futamura Kagaku Kogyo FOR # 20 6 Polyethylene Sekisui Kagaku Kogyo Protect tape # 624S 7 Polyethylene Sekisui Kagaku Kogyo Protect tape # 624C 8 Polyolefin Sanecaken PAC-2-50THK

Claims (8)

A package for packaging and sealing a glass substrate, the film comprising a film that does not contaminate the glass substrate surface. The package of claim 1 wherein the film is a polyethylene terephthalate film. The package of claim 1 wherein the film is a laminated film comprising a plurality of layers. The package according to claim 3, wherein the innermost layer of the layer constituting the laminated film is a polyethylene terephthalate layer. The package according to claim 3 or 4, wherein at least one layer of the layer constituting the laminated film has moisture resistance. 6. The package of claim 5, wherein the at least one layer having moisture resistance is an aluminum layer rather than the innermost layer. The package of any one of claims 1 to 6, wherein air is removed from the interior volume of the package. The package according to any one of claims 1 to 7, wherein the glass substrate is a glass substrate for a liquid crystal display.