WO2002053474A1

WO2002053474A1 - Cushioning body for glass substrate and packing body using the cushioning body

Info

Publication number: WO2002053474A1
Application number: PCT/JP2001/011472
Authority: WO
Inventors: Yasushi Ueda; Itsuo Hamada
Original assignee: Asahi Kasei Kabushiki Kaisha
Priority date: 2000-12-27
Filing date: 2001-12-26
Publication date: 2002-07-11
Also published as: JPWO2002053474A1; KR100552879B1; DE10197125B3; JP4091432B2; CN1222449C; KR20030093192A; CN1482985A

Abstract

A cushioning body for glass substrate having an L-shaped section and the thickness of the L-shaped section at the end part larger than the thickness thereof at the corner part, wherein (1) the thickness of the cushioning body is gradually decreased from the end part to the corner part of the L-shaped section with the bottom part of a fixture guide groove taken as a reference by forming the fixture guide groove so that the depth thereof is gradually increased from the end part to the corner part of the L-shaped section, (2) the cushioning device is formed so that the thickness of the cushioning body itself is gradually decreased from both end parts to the corner part of the L-shaped section without forming the fixture guide groove, and (3) a projected part is formed at both outer end parts of the L-shaped section of the cushioning body, whereby a fixture tightening force is prevented from being concentrated to the corner part when the cushioning body is tightened with a fixture.

Description

Description Buffer for glass substrate and package using the buffer <Technical field>

The present invention relates to a transfer buffer for protecting a glass substrate having electronic components such as a semiconductor device formed on a glass substrate from damage due to vibrations during transportation, and the above glass substrate using the buffer. The present invention relates to a package in which a plurality of sheets are packed at the same time.

In recent years, the production volume of electronic and electrical equipment, especially liquid crystal displays and plasma displays, which are one of the peripheral devices of personal computers, and mobile terminals such as mobile phones, has been increasing with the development of the information technology industry represented by the Internet. The equipment is growing at a rapid pace, and there is a strong demand for the development of shock absorber-related technologies used for packaging and transport. Above all, the thickness of glass substrates incorporating electronic components such as semiconductor devices, such as color filters and TFT liquid crystal cells (substrates on which circuits incorporating thin film transistors are formed), and the glass substrates used for liquid crystal panels, etc., are thin. In addition, it is vulnerable to shocks and vibrations during transportation, and its structure is extremely fine, making it susceptible to external influences and difficult to handle. In particular, when transporting a glass substrate before processing or a semi-finished product before it becomes a final product, the above electronic components are handled in a bare state, and are more strongly affected by static electricity, dust, dust, etc. In some cases, the functions of and were impaired.

Therefore, many packaging techniques have been proposed for safely transporting glass substrates without damaging them.

As an example, there is a technique disclosed in Japanese Patent Application Laid-Open No. 5-319456. The key point is a buffer made of a polyolefin bead foam having specific characteristics and having a substantially L-shaped cross section and a plurality of substrate insertion grooves provided inside along the L-shape. When packing glass substrates, place multiple glass substrates at predetermined intervals. A rectangular parallelepiped is formed by arranging in parallel, corners of each substrate are inserted into the respective substrate insertion grooves of the buffer, and four sides of the rectangular parallel to the substrate surface are fitted by the buffer. In addition, fix with rubber or tape as necessary.

However, when a fastener such as rubber or tape is fixed to the outside of the shock absorber, the fastening force is concentrated on the corners of the shock absorber, so that the L-shape is opened and the glass base is covered at both ends. In some cases, the protection function did not work sufficiently due to the deviation from the board insertion groove.

Further, in the L-shaped buffer, the groove width of the substrate insertion groove is formed to be equal to or slightly smaller than the thickness of the glass substrate, and the elastic recovery property during compression, which is a characteristic of the polyolefin bead foam, is used. The glass substrate is fixed using the height. Therefore, it is effective for dust generation resistance due to vibration friction with the glass substrate during transportation, but when packing the glass substrate, which is the original purpose, the frictional resistance with the glass substrate has an adverse effect. However, if you try to force the glass substrate into the substrate insertion groove, the glass substrate, which is extremely thin, about 0.4 to 1.0 mm, can easily break and bend easily. There is a problem that it takes a long time. This is the same when taking out the glass substrate. In recent years, in particular, automatic storage and unloading devices for glass substrates have been introduced in terms of labor saving, but some problems have been pointed out as problems are likely to occur due to the above problems, and they are not suitable for automation.

Further, when the glass substrate is inserted into the substrate insertion groove, a fine abrasion may occur on the surface of the glass substrate due to frictional resistance, which is a problem.

In view of the above problems, the problem of the present invention is that the groove of the glass substrate at the end of the L-shape of the buffer does not slip when packing the glass substrate, and the glass is not subjected to external force such as vibration or drop impact during transportation or handling. It is an object of the present invention to provide a buffer for a glass substrate that can safely protect the substrate, and is suitable for automating storage and removal of the glass substrate, and generates dust easily even when the glass substrate is rubbed. Another object of the present invention is to provide a buffer for a glass substrate which is excellent in durability and can be used a plurality of times, and provides a package which is packed using these buffers. <Disclosure of Invention>

The first buffer for a glass substrate of the present invention is a buffer for a glass substrate made of a polyolefin bead foam, has a substantially L-shaped cross section according to the shape of a corner of the glass substrate, and The inside surface is provided with a plurality of substrate insertion grooves for fixing the two sides forming the corners of the glass substrate, and the outside surface is provided with at least one fixing tool formed along the L-shape.緩衝 The groove has a groove, and the thickness of the buffer body with respect to the bottom of the fixture guide groove is gradually reduced from both ends of the L-shape to the corners. The first buffer member for a glass substrate of the present invention preferably includes a chamfered bottom portion of the fixture guide groove at the corner.

The second buffer for a glass substrate of the present invention is a buffer for a glass substrate made of a polyolefin bead foam, having a substantially L-shaped cross section according to the shape of the corner of the glass substrate. The inside surface is provided with a plurality of substrate insertion grooves for fixing the two ends forming the corners of the glass substrate, and the thickness of the buffer gradually decreases from both ends of the L-shape toward the corners. Is what it is.

The third buffer for a glass substrate of the present invention is a buffer for a glass substrate made of a polyolefin bead foam, and has a substantially L-shaped cross section according to the shape of the corner of the glass substrate, The inside surface is provided with a plurality of substrate insertion grooves for fixing two sides forming a corner of the glass substrate, and convex portions are formed at both outer ends of the L-shape. .

The second and third buffer members for a glass substrate of the present invention preferably include that the outer corners are chamfered.

Further, the buffer for a glass substrate of the present invention has a cutout groove on the inner side in a direction perpendicular to the substrate insertion groove, the maximum thickness of the buffer is 10 to 60 mm, and two sides of an L-shape. Is 1.0 to 3.0 on the short side basis, the groove width of the substrate insertion groove is 1.0 to 4.0 times the thickness of the glass substrate, and the groove depth is 3 to 15 mm. The pitch is 6 to; L0 Omm, the polyolefin bead foam has an average particle diameter of 1.5 to 5.0 mm, and a fusion rate of 70. /. As described above, the preferred embodiment includes a compression elasticity index of 3.9 to 490 and a recovery rate of 60% or more. Further, the first package of the present invention comprises a plurality of glass substrates arranged in parallel at predetermined intervals to form a rectangular parallelepiped, and the corners of each substrate are respectively formed on the substrate of the first glass substrate buffer of the present invention. The four sides of the rectangular parallelepiped which is inserted into the insertion groove and orthogonal to the substrate surface are fitted by the buffer, and a long fixing tool is wound along the fixing guide groove of the buffer. It is characterized by being concluded.

Further, in the second package of the present invention, a plurality of glass substrates are arranged in parallel at a predetermined interval to form a rectangular parallelepiped, and the corners of each substrate are respectively formed in the second or third glass substrate of the present invention. Four sides of the rectangular parallelepiped, which is inserted into the substrate insertion groove of the buffer and is orthogonal to the substrate surface, are fitted by the buffer, and a long fixing tool is formed outside the buffer along the L-shape. It is characterized by being wound and fastened.

FIG. 1 is a perspective view of one embodiment of the shock absorber of the present invention.

FIG. 2 is a perspective view of one embodiment of the package of the present invention.

3 (a) to 3 (e) are schematic cross-sectional views of an embodiment of the buffer according to the present invention. 4 (a) to 4 (c) are schematic cross-sectional views showing a configuration example of the substrate insertion groove of the buffer of the present invention.

In the figures, 1 is a buffer, 2 is a groove for inserting a board, 3 is a guide groove for a fixture, 4 is a ridge, 21 is a glass substrate, 22 is a fixture, and 31 is a wall surface of a buffer. , 32 is the bottom of the board insertion groove, 33 is the L-shaped end, 34, 34 'is the L-shaped corner, 35 is the bottom of the fixture guide groove, 36 is the chamfer, 37 Is a notch groove, 38 is a convex portion, and 39 is a concave portion. BEST MODE FOR CARRYING OUT THE INVENTION>

The shock absorber of the present invention is characterized in that, in a shock absorber made of a polyolefin bead foam and having a substantially L-shaped cross section, the end of the L-shape is formed to be thicker than a corner. Accordingly, when the glass substrate is packed and the outside is fastened by the fixture, the fixture passes through the outside of the corner at the end of the L-shape, and the fastening force of the fixture is reduced to the corner. To protect the glass substrate by pressing the entire buffer evenly can do.

In the present invention, a specific configuration for making the thickness of the L-shaped end of the buffer body larger than the corners is as follows.

(1) By forming the depth of the fixture guide groove so as to increase from the end of the L-shape toward the corner, the thickness of the buffer at the bottom of the guide groove of the L-shape is reduced. Gradually decrease from the part toward the corner.

(2) Form the buffer so that the thickness of the buffer itself decreases gradually from both ends of the L-shape to the corners without forming the fixture guide groove.

(3) Protrusions are formed at both ends of the cushion outside the L-shape. Hereinafter, the buffer of the present invention and a package in which a plurality of glass substrates are integrally packaged using the buffer will be specifically described with reference to embodiments.

FIG. 1 is a perspective view of one embodiment of the shock absorber of the present invention having the above-mentioned configuration (1). In the figure, 1 is a buffer, 2 is a board insertion groove, 3 is a fixture guide groove, and 4 is a ridge that separates adjacent board insertion grooves 2. FIG. 2 is a perspective view of an embodiment of the package of the present invention in which a plurality of glass substrates are packed using four of the buffers. In the figure, 21 is a glass substrate, 22 is a fixture, and the same members as those in FIG.

The buffer 1 of the present invention protects the corners of the glass substrate 21 and fixes a plurality of the substrates integrally. However, two or more, preferably four, are packaged.

As shown in FIG. 1, the buffer 1 of the present invention has a substantially L-shaped cross section according to the shape of the corner of the glass substrate. A plurality of substrate insertion grooves 2 are provided along the groove and are separated from each other by the ridges 4. In the case where the configuration (1) is provided, the fixture guide groove 3 is formed along the L-shape. As shown in FIG. 2, the fixing tool guide groove 3 is for winding the fixing tool 22 along the guide groove 3 after packing the glass substrate 21. When the groove 3 is provided, the depth is changed so that the thickness of the buffer 1 at the bottom gradually decreases toward the corner. FIG. 3 (a) schematically shows a cross section along the fixture guide groove 3 and the substrate insertion groove 2 of the buffer 1 in FIG. In FIG. 3, 3 1 Is the outer wall surface of the buffer 1, 32 is the bottom of the board insertion groove 2, 33 is the L-shaped end of the buffer 1, 34, 34 'is the L-shaped corner, and 35 is the fixture guide. The bottom of the groove 3, 36 is a chamfered portion, 37 is a cutout groove, 38 is a convex portion, and 39 is a concave portion. In the following description, the thickness at the corner 34 or 34 'means the thickness of the short side and the long side of the buffer at the inside corner of the L-shape.

As shown in FIG. 3 (a), the depth of the fixture guide groove is formed so as to be shallow at the end 33 of the L-shape and deep at the corner 34 ′ so that the guide for the fixture is formed. The thickness of the buffer at the bottom 35 of the groove gradually decreases from the L-shaped end 33 toward the corner 3 4 ′. As a result, when a long fixing tool is wound along the fixing guide groove after packing the glass substrate, the distance from the fixing device to the glass substrate is smaller at the end 33 than at the corner 3 4 ′. As a result, the fastening force of the fixing device can be prevented from being concentrated on the corners 3 4 ′.

Also, as shown in FIG. 3 (b), the chamfered portion 36 is preliminarily chamfered to prevent the fixing force of the fixing member from being concentrated on the corner portion 34 'of the bottom portion 35 of the fixing device guide groove. It is also preferable to form them. By forming the chamfered portion 36, there is no danger that the fixture will cut into the buffer and cause damage, the deformation distortion at the corner 34 'is reduced, and the end 33 of the buffer becomes difficult to open outward. . The chamfered portion 36 may have a flat shape or a curved shape.

Furthermore, as shown in FIG. 3 (c), a cut is made in the buffer body in a direction perpendicular to the board insertion groove (a direction perpendicular to the paper surface), and at least one notch groove 37 is provided. It is preferable that the notch groove 37 absorbs the deformation stress that tends to open the end portion 33 to the outside at the time of fastening by the fixing tool and does not propagate the deformation stress to the end portion 33. It should be noted that the shape of the notch groove 37 may be a substantially U-shape in addition to the substantially V-shape shown in FIG. 3 (c).

Further, in FIG. 3, a concave portion 39 from which the ridge 4 is partially removed is formed inside the corner portion 34 on the short side, which is caused by a vibration impact or a drop impact during transportation. This is a configuration for preventing the loss of the corner of the glass substrate that is most easily damaged when the glass substrate is subjected to the heat. In the recess 39, the ridge 4 is removed until it reaches the bottom 32 of the substrate insertion groove. Just do it. In addition, from the viewpoint of preventing the corners of the glass substrate from being damaged, it is preferable to form the glass substrate further deeper than the bottom 32.

In the present invention, the L-shaped end 33 of the buffer is configured to be thicker than the corner 34, and an example of the above-described configuration (2) is shown in FIG. 3 (d), and an example of the configuration (3) is shown in FIG. (e). In FIG. 3 (d), the thickness of the buffer itself is formed so as to gradually decrease from the L-shaped end 33 toward the corner 34. In this case, since the fixture guide groove is not particularly formed, the width and the winding position of the fixture can be freely selected. Further, in FIG. 3 (e), the thickness of the buffer is uniform, but a convex portion 38 is formed outside the L-shaped end 33, and as a result, the thickness of the buffer at the end 33 is square. It is thicker than part 34. The protruding portion 38 may be formed integrally with the main body, but may be separately formed into a plate shape and subsequently attached to the main body by heat fusion or an adhesive, in which case the same as the main body is used. It may be a material or a different material.

In the configurations of FIGS. 3 (d) and 3 (e), the chamfered portions 36 and the notched grooves 37 as shown in FIGS. 3 (b) and 3 (c) can be appropriately incorporated. Next, preferred external dimensions of the cushioning body of the present invention will be described.

In the buffer of the present invention, the ratio of the two sides of the L-shape (the length of the portion in contact with the glass substrate) is preferably 1.0 or more, more preferably 3.0 or less, based on the short side. Within this range, the balance between the long side and the short side is good, and the fixing stability of the rectangular glass substrate is very good. Also, the probability of the glass substrate being radiused and damaged is lower. More preferably, it is less than 2.7.

Further, within the above range, the length of the short side is preferably 10% or more of the length of the short side of the glass substrate to be packed, and more preferably 45% or less. Furthermore, it is preferably at least 15%, and most preferably at most 40%. If the length of the short side of the buffer is within the above range, even if it receives a drop impact, etc., there is a risk of damaging the glass substrate because the buffer is arranged to sufficiently absorb the impact force. Can be avoided. In addition, since the stress (self-weight of the glass substrate) applied to the buffer can be reduced, dust generation due to contact friction due to vibration during transport can be suppressed, and cleanliness can be satisfied. As a specific external dimension, the short side is preferably 10 Omm or more, more preferably 50 Omm or less. The long side is preferably 100 mm or more, more preferably 150 mm or less. Further, the length in the direction perpendicular to the short side and the long side depends on the number of glass substrates accommodated, but is preferably 15 Omm or more, more preferably 600 mm or less.

The maximum thickness of the buffer of the present invention is preferably 1 Omm or more, more preferably 60 mm or less, in view of the size, weight, number of packages, and compression index of the glass substrate. More preferably, it is 15 mm or more and / or 4 O mm or less. When the outer dimensions and the maximum thickness are within the above ranges, the glass substrate before processing can be used as a transfer buffer that can stably fix all glass substrate products of various dimensions as well as the glass substrate before processing. 'In addition, the glass substrate protection function that can sufficiently withstand the impact during transportation can be demonstrated.

Further, when the fixing tool guide groove is formed as shown in FIG. 3 (a), the depth thereof is preferably 0.5 mm or more at the end 33, more preferably 5 mm or less, and furthermore, the corners 34, Is preferably 2 mm or more, more preferably 15 mm or less. If the depth of the fixture guide groove is formed so as to fall within this range, the fastening force will not only be displaced but also over the entire short side and long side of the shock absorber when the fixture is fastened and fixed by the fixture. As a result, the four corners of the glass substrate can be fixed stably, thereby fully satisfying the protection function of the glass substrate. In FIG. 3 (a), the fixture guide groove is formed up to the end 33, but it may be formed near the end 33 so as to be flush with the outer wall 31 of the shock absorber. In this case, it is preferable that the fixture guide groove is separated from the end 33 by at least 10 mm, more preferably 10 mm from the end 33, and more preferably gradually deeper toward the corner 3 4 ′. It is more preferable to form them so that Within this range, there is no displacement of the fixture during conveyance, and the same effect as when the guide groove is formed from the end 33 described above can be obtained.

Further, when changing the thickness of the buffer body itself as shown in FIG. 3 (d), it is preferable that the thickness of the corner portion 34 is thinner than the thickness of the end portion 33 by 1 mm or more, more preferably 10 mm. It is as follows. More preferably, 0.3 mm or more, most preferably 8 mm or less It is. Also in this case, the end 33 is formed to have a uniform thickness with the thickness of the end 33 up to a position of 1 Oram or more in the direction of the corner 34 from the end 33 and more preferably 10 Omm or less. The same effect as above can be obtained even if the thickness up to the portion 34 is gradually reduced.

In the case of FIG. 3 (e), it is preferable that the thickness of the corner portion 34 is thinner than the thickness of the end portion 33 by 1 mm or more, more preferably 1 Omm or less. The means for reducing the thickness of the corner 34 can be achieved by forming a projection 38 near the end 33 as shown in FIG. Further, the width of the projection 38 in the direction along the L-shape is preferably 1 Omm or more, more preferably 10 Omm or less. More preferably, it is 20 mm or more, most preferably 8 Omm or less.

Furthermore, in the case of forming the chamfered portion 36 shown in FIG. 3 (b), in consideration of the compression elasticity index, the maximum thickness, the length of both sides, etc. of the shock absorber, an arc-shaped or The length is preferably 3 mm or more, and more preferably 6 Omm or less.

When the chamfer is within this range, when the glass substrate is packed and the outside is fastened by the fixture, the fastening force of the fixture is prevented from concentrating on the corners, so the entire buffer is even. To fix the corners of the glass substrate. Therefore, the function of fixing and protecting the glass substrate is further enhanced, and the phenomenon that the fixing tool is cut and bitten into the buffer even when the fixing tool is wound with a strong fastening force is eliminated, and the glass substrate is repeatedly reused many times over a long period of time. The durability can be greatly improved.

When the notch groove 37 shown in FIG. 3 (c) is formed, the groove depth is preferably 1/20 or more of the thickness of the buffer at the portion where the notch groove 37 is formed, and more preferably 1Z 2 The following is good. Further, the groove width is preferably 2 mm or more, more preferably 10 mm or less. Although the position and the number of the notch grooves 37 are not particularly limited, the side length (the portion where the glass substrate is in contact with the short side and the long side of the glass substrate in contact) is not particularly limited. Is preferably 1Z8 or more, more preferably 4/5 or less, more preferably 1 or more, more preferably 3 or less. When the cutout groove 37 is formed in the above range, the glass substrate can be inserted without impairing the rigidity of the buffer. Since the admission qualities of the glass substrate are improved over the entire length of the groove, the protection function of the substrate is improved, and the effect of lowering the frictional dust generation of the buffer is derived.

Further, when forming the concave portion 39 in FIG. 3, it is preferable that the bottom of the concave portion 39 be set so as to reach the bottom portion 32 of the substrate insertion groove. In consideration of the maximum thickness of the body, the bottom 32 of the board insertion groove should have a depth of at least 1 mm, most preferably at most 8 mm, most preferably at least 2 mm, most preferably at most 6 mm. It is good to form it. Within this range, even if the shock absorber is distorted and deformed due to a drop impact or the like, the probability of damage is extremely low because no external force is applied to the most fragile corner of the glass substrate. Further, since the structural strength of the cushioning member can be sufficiently maintained, the initial shape can be maintained even if the cushioning member is repeatedly used. Therefore, the function of fixing and protecting the glass substrate can be exhibited over a long period of time. '' "

The groove width of the substrate insertion groove formed in the buffer of the present invention is preferably 1.0 times or more and 4.0 times or less, more preferably 1.2 times or more and 3.5 times or more the thickness of the glass substrate to be packed. Double or less is better. Within this range, the insertion and removal of the glass substrate by a manual or automatic device can be performed quickly and efficiently, and the trouble of damage to the glass substrate during the insertion operation is drastically reduced. In addition, since the glass substrate is sufficiently fixed in the substrate insertion groove, the friction between the glass substrate and the buffer is suppressed even if it is subjected to vibration or shock during transportation, and the dust phenomenon is extremely low. Can be kept.

Further, the depth of the substrate insertion groove is preferably 3 mm or more, more preferably 15 mm or less, in view of the size and weight of the glass substrate, the compression elasticity index of the buffer, the groove width of the substrate insertion groove, and the like. Is good. More preferably, it is at least 5 mm and most preferably at most 1 Omm. Within this range, the glass substrate can be securely fixed with the glass substrate inserted into the insertion groove even if it is subjected to a vibration impact during transportation or a drop impact due to handling. Damage accidents such as contact with the substrate can be prevented. In addition, the portion where the glass substrate comes into contact with the substrate insertion groove is constantly rubbed with the buffer due to the vibration and impact during transportation, so that it is extremely possible that fine scratches are generated on the surface of the glass substrate. For example, when processing a transported glass substrate into a liquid crystal panel, etc., use it after cutting and removing the substrate portion that has been in contact with the substrate insertion groove of the buffer beforehand. This is generally the case, but if the groove depth is within the above range, the portion is extremely small, so that a decrease in yield can be kept small and economic efficiency is high. Further, the amount of dust generated by the rubbing between the glass substrate and the buffer is small, which is desirable from the viewpoint of cleanliness.

The pitch of the substrate insertion groove is determined by the type of glass substrate, etc. (eg, glass alone, force filter, liquid crystal module, liquid crystal, plasma display panel, etc.), its size, weight, compression elasticity index of the buffer, substrate insertion groove In view of the width and the suitability for automatic insertion and removal of the glass substrate, the thickness is preferably 6 mm or more, and more preferably 100 mm or less. Within this range, the workability of inserting and removing the substrate can be easily and reliably ensured, and the glass substrate may be in contact with the next substrate radially due to the vibration impact during transportation or the drop impact during handling. The danger of doing so can be avoided.

Also, in the cushioning body of the present invention, the cross-sectional shape of the ridge separating the adjacent substrate insertion grooves is a flat top as shown in FIG. 4 (a). In consideration of the workability of inserting the glass substrate and dust generation at the time of insertion, a guide section is provided on the upper part of the ridge, as shown in a chevron (Fig. 4 (b)) or a trapezoid (Fig. 4 (c)). The formed two-stage shape is preferable, and the trapezoid is more preferable. With a trapezoid, the mold used for in-mold molding can be manufactured with high precision even for a buffer with a narrow storage groove pitch. In the figure, t1 is the maximum thickness of the buffer 1, t2 is the depth of the substrate insertion groove 2, t3 is the groove width, and t4 is the groove pitch. Next, the constituent material of the buffer of the present invention will be described.

The buffer of the present invention comprises a polyolefin bead foam. The foam is obtained by filling foamed polyolefin beads in a mold having a desired shape, heating and foaming with steam, cooling, and forming the foam into a desired shape. As a mold used for the molding, a mold obtained by a solid-state method can be used.錶 Mold by metal method can be easily manufactured with high precision even for complicated shapes, and it is economical and mass-produced because the manufacturing cost is less than 10 times less than injection mold. It is suitable for The polyolefin used for molding the polyolefin bead foam used in the present invention may be either a crosslinked type or a non-crosslinked type. Specific examples of the resin material include low, medium, high density polyethylene, linear low density polyethylene, Linear ultra low density polyethylene, Random and block copolymers of propylene with polyethylene-based resins typified by polyethylene and ethylene-vinyl acetate copolymer, and copolymer components such as ethylene, butene 1-1, and 4-methylpentene 11 Examples thereof include a polymerized polypropylene resin, a random copolymerized polypropylene resin obtained by using a meta-mouth catalyst, and a composition in which two or more of the above are blended.

Among them, random polyethylene resin, the resin density 0. 9 2 7 g Z cm 3 or more, more preferably 0. 9 7 0 g / cm 3 or less of those or ethylene Ya butene one 1 and pro pyrene A copolymerized polypropylene resin is a preferred example. When the polyethylene resin density is within the above range, the buffer has properties such as moderate rigidity, flexibility, and recoverability, and has sufficient practical performance as a buffer for transporting a glass substrate, such as shape stability and drop. The shock absorbing performance at the time, durability of repeated use and dust resistance are extremely improved. In addition, the expansion ratio of the shock absorber can be relatively increased to obtain a specific compression elasticity index, which is excellent in terms of lightness and economy. In addition, since the random copolymer polypropylene resin of ethylene butene and propylene has higher elasticity than polyethylene resin, it is suitable for a buffer of a large-sized glass substrate. It is preferable because the initial state can be maintained even after repeated use and the durability is excellent.

First, the buffer made of the polyolefin bead foam of the present invention preferably has an average particle size of 1.5 mm or more, more preferably 5.0 mm or less, of the foamed particles constituting the buffer. It is more preferably at least 2.0 mm, most preferably at most 4.5 mm. When the average particle diameter is in this range, the surface area ratio per volume of the foamed particles is small, so that the rate at which the gas pressure (air) in the particles escapes and decreases during steam heating in the in-mold molding is extremely small. As a result, sufficient heat-expandable foaming properties are exhibited. As a result, very little voids are hardly generated between the foamed particles on the surface of the obtained in-mold body, and when used as a buffer for transporting a glass substrate, dust in the air penetrates into this portion. It is excellent in cleanliness. In addition, even when filling the foamed particles into the mold, the foamed particles can be filled into the details of the narrow groove of the substrate, so that the effect of obtaining a high-precision buffer in accordance with the shape and dimensions of the mold can be obtained. is there. The average particle diameter of the foamed particles refers to three straight lines with a length of 100 mm on the surface of the in-mold molded product, which are marked with a ballpoint pen, and the number of foamed particles in contact with this straight line is measured. Then, the average particle diameter C [mm] is calculated from the following equation (A). The evaluation is the average value evaluated with three straight lines.

C = (1.66 6 X L) / N… (A)

L: Center line length [mm], N: Number of particles

A second requirement of the buffer comprising the polyolefin bead foam of the present invention resides in the properties of the buffer. That is, the fusion rate is preferably 70% or more, the compression elasticity index is 3.9 or more (more preferably, 490 or less), and the recovery rate is preferably 60% or more.

The above fusion rate refers to the total length in the thickness direction of the fractured surface when a cut with a depth of about lmm is made in the thickness direction of the buffer body, and the cut is made with the cut outside. The total number of foamed particles and the number of foamed particles that have been ruptured (material destruction) in the area over the length of 75 mm are measured, and the value obtained by dividing the number of broken particles by the total number of foamed particles is shown as a percentage. It is a numerical value. In the present invention, when the fusion rate is 70% or more, the inherent properties of the polyolefin bead foam inherently related to mechanical strength such as compression and tension are sufficiently exhibited. In other words, the innumerable foamed particles constituting the buffer are fused and integrated firmly with each other, so they have excellent durability and recoverability.When the glass substrate is fixed and packaged using this buffer, Because it can withstand strong fastening force, it can fix and package the glass substrate at a high level, and the probability of damaging the glass substrate is further reduced. Furthermore, since there is no minute gap between the foamed particles on the surface of the buffer body and the water absorption is substantially zero even in the washing and washing performed repeatedly after each use, there is also an effect that the drying workability is excellent.

Further, in the present invention, when the compression elasticity index of the shock absorber is in the above range, the excellent shock-absorbing performance inherent in polyolefin can be efficiently exhibited to the maximum, and the appropriate rigidity and flexibility are well balanced. In addition, the protection function is very high, especially if the glass substrate size exceeds 50 Omm X 60 Omm and the stability is fixed. In addition, since it has sufficient strength to withstand external forces during transport and handling, it is slightly deformed and has durability that can be used repeatedly over a long period of time. Also, The expansion ratio of the buffer can be relatively increased to obtain a specific compression elasticity index, which is excellent in terms of lightness and economy.

Furthermore, since the compression elasticity index is within the above range and the recovery rate is 60% or more, the polyolefin bead foam has excellent repetition durability, which is the largest characteristic, and is deformed even when used frequently. It can be kept small.

The compression elasticity index is a value obtained by dividing the compression elastic modulus (NZ cm ² ) by the expansion ratio.

The above-mentioned compression modulus is a value obtained in accordance with JISK7220 for a sample in which the following expansion ratio is measured, and the compression speed is 1 OmmZ. If the sample thickness is less than 2 Omm, measure multiple samples so that the thickness is about 20 mm. The foaming ratio is as follows: From the buffer, cut out a flat test piece with a width of 50 mm, a length of 50 mm and a thickness of 2 Omm, measure the weight (g) to 1 Omg, and then use a vernier caliper The length and thickness are measured, the volume (cm ³ ) is calculated, and the expansion ratio E [cm ³ / g] is calculated from the following equation (B).

E = volume / weight [cm ³ / g]… (B)

The above-mentioned recovery rate refers to a compression test apparatus “Autograph AG-150” manufactured by Shimadzu Corporation, which is obtained by cutting a flat test piece having a width of 50 mm, a length of 50 mm, and a thickness of 20 mm from the buffer. After compressing to 50% of the thickness of the test piece at a compression speed of 1 OmrnZ using `` 0 0D '', immediately remove it until the load becomes zero at the same speed, and remove the thickness at the moment when the load becomes zero. The recovery rate R [%] is calculated from the following formula (C). If the thickness is less than 20 mm, measure multiple layers so that the thickness is about 20 mm.

R = (ΎΙ / ΎΟ) X I 0 0 [%]… (C)

TO: Thickness before test [mm], T1: Thickness after test (when load is zero) [mm] Next, the package of the present invention will be described. In the package of the present invention, a plurality of glass substrates are packed in a set of two or more of the above-described buffers of the present invention, and preferably in a set of four. That is, a plurality of glass substrates are arranged in parallel at a predetermined interval to form a rectangular parallelepiped, and the corners of each substrate are inserted into the substrate insertion groove of the buffer of the present invention, respectively, and are orthogonal to the substrate surface. The four sides of the rectangular parallelepiped are fitted by the buffer. afterwards, Wind and fasten a long fixture along the L-shape of the buffer. When the shock absorber has a fixture guide groove, the fixture is wound along the fixture guide groove.

Incidentally, a dummy glass substrate may be arranged as the outermost glass substrate. Embodiments other than the glass substrate package using the buffer of the present invention will be described below.

In the same manner as above, a plurality of glass substrates are arranged in parallel at a predetermined interval to form a rectangular parallelepiped, and the corners of each substrate are inserted into the substrate insertion grooves of the buffer of the present invention, respectively. The four sides of the rectangular parallelepiped perpendicular to the surface are fitted by the buffer. After that, a long fixture is wound along the L-shaped of the buffer along the fixture guide groove, fastened and fixed to form a package, and the package is heat-shrinkable resin film. The film is subjected to a heat treatment to shrink the film by heat, and is shrink-wrapped.

When wrapping the package with the heat-shrinkable resin film as necessary, after storing the package in a bag-shaped or tubular-shaped film, preferably heat-sealing the end of the film. The film may be sealed, and the film may be heat-shrinked to adhere to the package. The above-described package is characterized in that a package in which a plurality of glass substrates are integrally packaged using the buffer of the present invention is shrink-wrapped using a heat-shrinkable resin film. Even with a glass substrate package, the packaging operation of the package is easy, and automatic packaging is possible. In the package after packaging, since the heat-shrinkable film has no looseness, the film does not come into contact with the outermost substrate of the package and the glass substrate is not contaminated. There is no need to use a dummy substrate, and the buffer can be used effectively and the efficiency is high. Furthermore, since the entire buffer is pressed from the outside by the shrinkage stress of the film, the buffer and the glass substrate are satisfactorily fixed together, so that the groove of the glass substrate is not dislodged or damaged. Rubbing between the glass substrate and the buffer due to vibrations at the time is drastically reduced, thereby preventing the glass substrate from being scratched or adhering dust and keeping the glass substrate clean.

Examples of the heat shrinkable resin film used for shrink packaging include a polyolefin resin film and a polychlorinated vinyl resin film. Due to its properties, a large amount of plasticizers and stabilizers are added to the resin in order to impart processability and flexibility during extrusion film formation. These additives exude to the surface of a film or the like over time after film formation, or cause a very small amount of volatilization even at room temperature, thereby deteriorating the cleanliness of a work place for packaging glass substrates. In addition, there is a risk of causing a fatal contamination problem such as indirect contact of the additive attached to the hand when handling the packaging of the glass substrate. In order to prevent dust from entering from outside during transportation, it is desirable to heat seal the film and seal the package.However, polychlorinated vinyl resin is not suitable for heat sealing. Since expensive equipment such as a sound wave or high frequency sealing device is required, it is preferable to use a polyolefin resin film.

As the polyolefin-based resin film, a single-layer or multi-layer product of a polypropylene-based resin or a polyethylene-based resin, or a crosslinked or non-crosslinked type is preferably used.

Such a polyolefin-based resin film preferably has a heat shrinkage at 120 ° C. of preferably at least 15% in at least one of the vertical and horizontal directions, more preferably 90% or less. Most preferably, it is 20% or more. More preferably, it is 15% or more and 90% or less in both the vertical and horizontal directions. If heat shrinkage is performed in this range, the package is tightly shrink-wrapped without loosening, and there is no possibility that the glass substrate comes into contact with the film to contaminate the glass substrate. The heat shrinkage is a value measured at 120 ° C. by the method of ASTM D-2732.

Further, the maximum heat shrinkage stress at 120 ° C. is preferably 0.15 NZmm ² or more, more preferably 5 NZmm ² or less, in at least one of the vertical and horizontal directions. Most preferably, it is not less than 0.2 N / mm ^{2 and not} more than 4.5 N / mm ² . More preferably, the vertical, in the lateral direction both 0. 1 5 NZmm ² or more, 5 NZmra ² below.

When the maximum heat shrinkage stress at 120 ° C is within the above range, the package is tightly shrink-wrapped without loosening, and the film does not easily come into contact with the glass substrate even when the film is pressed at the time of handling. The cleanliness of the substrate is maintained. In addition, since the heat shrinkage stress is moderate, the film can be sealed and sealed without breaking at the corners during packaging. Intrusion of dust from the air can be blocked.

The maximum heat shrinkage stress is a value measured at 120 ° C. by ASTM D—2838.

Further, the thickness of the polyolefin resin film is preferably 10 m or more, more preferably 200 m or less. It is even more preferably 20 or more, and most preferably 180 μηι or less. When the thickness is in this range, the film has an appropriate stiffness, so that the packaging workability of the package can be performed easily, efficiently, and efficiently. In addition to being able to perform heat sealing with high welding strength, it has breaking strength to withstand impact during transport and handling.

The fixing tool used in the present invention may be a long string-shaped or tape-shaped fixing tool. For example, a polypropylene tape is preferably used. 'Further, although the buffer of the present invention is used in a set of four, the four may be completely the same or may have different configurations. For example, when packing a large glass substrate, The buffer located below may be large and thick to withstand the weight of the glass substrate.

The buffer of the present invention may be used not only as a set of four but also as a stopper for preventing the absorber of the present invention from moving to the inner bottom of a plastic container or a plastic cardboard box having an open top. The two are fixed in the opposite direction using a tool, etc., and the glass substrate is inserted and fixed from the upper opening.If necessary, cover the box with a box to prevent dust from entering from the upper opening. It can be used for storing glass substrates. In this case, by attaching the buffer or the plate-like plastic foam of the present invention to the glass lid, it can be used as a transport container.

(Example 1, Reference Example 1)

(Glass substrate)

Mother glass for liquid crystal display

Dimensions: 600 mm X 720 mm Thickness: 0.1 mm

(Foam)

Resin material: Ethylene propylene random copolymer having an expansion ratio of 20 cm ³ / g Average particle diameter of expanded resin particles: 3.6 mm

Fusion rate: 86%

Compression modulus: 549 N / cm ²

Compression elasticity index: 27.5

(Buffer)

Glass substrate capacity: 26

External dimensions;

Short side: 250 mm

Long side: 350 mm

Length (length perpendicular to short side and long side): 300mm

Maximum thickness: 32mm

Board insertion groove;

Width: 2.4 mm

Depth: 1 2mm

Pitch: 20 mm

Sectional shape of the ridge: a trapezoid with a 6.5 mm wall perpendicular to the bottom of the board insertion groove and a top with a width of 8 mm and a height of 5.5 mm (Fig. 4 (c)) Shape)

(Fixture guide groove)

A total of two cushions with a width of 30 mm were provided at 1/4 the length (300 mm) of the buffer from both sides. The depth of the groove is 1 mm at the end of the L-shape, an arc-shaped chamfer with a radius of 20 mm is formed at the corner, and the depth of the groove at the connection between the bottom of the groove and the chamfer is 4 mm. did.

(Free drop test)

The above-mentioned glass substrate was packaged as shown in FIG. 2 using four of the above-mentioned buffer bodies to obtain a package. In order to evaluate the cushioning performance of the cushioning body in this package, The test was performed. As Reference Example 1, the same test was performed using exactly the same buffer except that the fusion ratio was 65%.

Test condition

Drop height: 30 cm

Falling surface of package: only at the location of the package

Number of drops: 3 times

The package of Example 1 did not fall off the glass substrate at all after falling three times, and kept the glass substrate packaged state before the test, and showed no damage to the glass substrate. In addition, the adhesion of the buffer dust to the glass substrate surface can be visually observed. No dust of a size was observed at all.

In the package of Reference Example 1, although the glass substrate did not fall off, a small chip was generated at the end of the glass substrate that was in contact with the groove in the long side direction of the absorber arranged on the ground. . It is considered that, as a result of closely observing the buffer in order to determine the cause of the occurrence of the chipping, a crack was generated between the foam beads, and the glass substrate bit into the buffer due to a drop impact. In addition, it was found that the foamed beads had fallen off, indicating that the durability to withstand repeated use was inferior to that of the buffer of Example 1. That is, it is probable that the fusion rate of the buffer was less than 70%, so that the mechanical strength of the buffer was inferior, and that excessive strain occurred when subjected to a drop impact.

(Example 2, Comparative Example 1)

(Glass substrate)

Mother glass for liquid crystal display

Dimensions: 5.50 mm X 6.50 mm

Thickness: 0.7 mm

(Foam)

Resin Material:. Resin Density expansion ratio at 1 0 cm ³ / g is 0 9 3 0 g Z c ni 3 of crosslinked polyethylene

Average particle size of expanded particles: 2.8 mm Fusion rate: 98%

Compression modulus: 4 12 N / cm ²

Compression elasticity index: 4.1.2

(Buffer)

Glass substrate capacity: 1 2

External dimensions;

Short side: 2 1 Omm

Long side: 3 10 mm

Length (length perpendicular to short side and long side): 240mm

Maximum thickness: 23 mm

Board insertion groove; · '■ Width ··· 1.5 mm

Depth: 7mm

Pitch: 20 mm

Cross-sectional shape of the ridge: 3.5 mm wall perpendicular to the bottom of the board insertion groove and 3.5 mm height at the top (Fig. 4 (b) shape)

(Fixture guide groove)

A total of two wires with a width of 25 mm were provided at 1/4 of the length of the buffer (240 mm) from both sides. A groove is formed from the position of 5 Omm toward the corner from the end of the L-shape to the corner, an arc-shaped chamfer with a radius of 1 Omm is formed at the corner, and the bottom and the chamfer of the groove The depth of the groove at the connection part with was set to 3 mm.

〔Vibration test〕

The above-mentioned glass substrate was packaged as shown in FIG. 2 using four of the above-mentioned buffer bodies to obtain a package. A vibration test was performed to evaluate the performance of fixing the buffer in the glass substrate package in this package. The vibration test was performed by fixing the package on a vibration table of a vibration test apparatus and following the test method of JISZ0232. Further, as Comparative Example 1, the same test was performed using exactly the same buffer, except that the depth of the fixture guide groove was set to 1 mm at all portions. Test condition

Vibration direction: up and down

Vibration waveform: sine wave

Sweep: Logarithmic sweep (frequency 5 to 100 Hz)

Sweep speed 0.5 octave Z minutes

Vibration acceleration: ± 0.75 G

Vibration time: 30 minutes

Visual observation of the fixed state of the glass substrate in the package after the end of the vibration test revealed that, in the package of Example 2, the glass substrate was slightly loose, but none of the glass substrates fell out of the substrate insertion groove. Was. In addition, no dust having a size observable visually was observed at all on the adhesion of the buffer dust to the glass substrate surface.

In the package of Comparative Example 1, 8 minutes after the start of the vibration test, the glass substrate came off in the board insertion groove on the long side of the upper two cushions, and it came into contact with the adjacent glass substrate, which could cause damage. As a result, the study was discontinued. Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

This application is based on a Japanese patent application filed on Dec. 27, 2000 (Japanese Patent Application No. 2000-396934), the contents of which are incorporated herein by reference. Industrial applicability>

As described above, when the shock absorber of the present invention is fastened by the fastener, the fastening force of the fastener is prevented from concentrating on the corners, so that the glass substrate can be satisfactorily pressed against the glass substrate even at the end. The groove of the substrate is not displaced, and a good protective effect is exhibited. In particular, the shock absorber of the present invention has its dimensions adjusted, and by using a foam having a specific characteristic as a constituent material, the work of packing and removing the glass substrate becomes easy, which is also suitable for automation. Becomes In addition, excellent dust generation and durability, work in a clean room It can withstand repeated use many times. Therefore, in the package of the present invention in which a plurality of glass substrates are packed using the buffer of the present invention, the internal glass substrate is reliably protected against vibration impact and drop impact during transportation, and defective products are protected. The occurrence is greatly reduced.

Claims

The scope of the claims

1. A buffer for a glass substrate made of a polyolefin bead foam, which has a substantially L-shaped cross section according to the shape of the corner of the glass substrate, and the inner surface along the L-shaped portion has a corner of the glass substrate. A plurality of substrate insertion grooves for fixing the two side ends are provided, and at least one fixture guide groove formed along the L-shape is provided on the outer surface. A buffer for a glass substrate, wherein the thickness of the buffer relative to the bottom of the groove gradually decreases from both ends of the L-shape to the corners.

2. The buffer for a glass substrate according to claim 1, wherein the bottom of the fixture guide groove at the corner is chamfered. .

3. A buffer for a glass substrate made of a polyolefin bead foam, having a substantially L-shaped cross-section according to the shape of the corner of the glass substrate, and the inside of the glass substrate along the L-shape having a corner of the glass substrate. A buffer for a glass substrate, wherein a plurality of substrate insertion grooves for fixing the two side ends are provided, and the thickness of the buffer gradually decreases from both ends of the L-shape to the corners.

4. A buffer for a glass substrate made of a polyolefin bead foam, which has a substantially L-shaped cross section according to the shape of the corner of the glass substrate, and the inner surface along the L-shaped portion has a corner of the glass substrate. A buffer for a glass substrate, comprising a plurality of substrate insertion grooves for fixing two side ends, and convex portions formed at both outer ends of the L-shape.

5. The buffer for a glass substrate according to claim 4, wherein an outer corner of the buffer is chamfered.

6. The buffer for a glass substrate according to any one of claims 1 to 5, wherein a cutout groove is provided inside the buffer in a direction orthogonal to the substrate insertion groove.

7. The maximum thickness of the buffer is 10 to 60 mm, the ratio of the two sides of the L-shape is 1.0 to 3.0 based on the short side, and the width of the substrate insertion groove is the thickness of the glass substrate. The buffer for a glass substrate according to any one of claims 1 to 5, wherein the buffer pitch is 1.0 to 4.0 times, the groove depth is 3 to 15 mm, and the groove pitch is 6 to 100 mm. body.

8. The polyolefin bead foam has an average particle diameter of 1.5 to 5.0 mm, a fusion rate of 70% or more, a compression elasticity index of 3.9 to 490, and a recovery rate of 6 The glass substrate absorber according to any one of claims 1 to 5, which is 0% or more.

9. Multiple glass substrates,

2. The glass substrate buffer according to claim 1, wherein the plurality of glass substrates are held in a state of being arranged in parallel at a predetermined interval by inserting four corners of the glass substrate into a substrate insertion groove. , as well as

A long fixing tool wound to be fastened along the fixing tool guide groove of the shock absorber.

10. Multiple glass substrates,

The glass according to claim 3 or 4, wherein the plurality of glass substrates are held in a state of being arranged in parallel with a predetermined interval by inserting four corners of the glass substrate into a substrate insertion groove. Substrate buffer, and

A package comprising a long fixing tool wound around the outside of the cushioning body for fastening along the L-shape.