JP2002362641A - Cushioning body for glass substrate, and package using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cushioning body which integrally packs a plurality of glass substrates to form an electronic part or the like, does not require a dummy substrate, and is suitable for the packing work in a clean room, especially for the automation, and of which the reuse is possible. SOLUTION: An internal die molded body of a polyolefin resin expanded particle having specified physical properties is used. Then, on both side ends of a main body 2 of which the cross section is an L-shape, a side wall 4 which extends to the total length of the L-shape is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer buffer for protecting a glass substrate having an electronic component such as a semiconductor device formed on a glass substrate from damage due to vibration or the like during transportation.
The present invention relates to a package in which a plurality of the glass substrates are packed at the same time using the buffer.

[0002]

2. Description of the Related Art In recent years, electronic and electrical related devices, particularly liquid crystal displays and plasma displays, which are one of the peripheral devices of personal computers, and mobile terminals such as mobile phones have been used in information technology industries such as the Internet. The production volume is increasing rapidly with the development, and there is a strong demand for the development of buffer-related technology used for packing and transporting the devices. Among them, glass substrates incorporating electronic components such as semiconductor devices, for example, a color filter glass substrate, a TFT glass substrate (a substrate on which a circuit incorporating a thin film transistor is formed), and a glass substrate such as a liquid crystal panel substrate have a small thickness. It is susceptible to external shocks and vibrations generated during transportation, and has a very fine structure. In particular, when transporting a glass substrate before processing or a semi-finished product before becoming a final product, the above electronic components are handled in a bare state, so they are more strongly affected by static electricity, dust, dust, etc. In some cases, the function was impaired.

[0003] Therefore, many packaging techniques have been proposed for safely transporting the glass substrate without damaging it.

As one example, Japanese Patent Application Laid-Open No. 5-319456 discloses
The technology disclosed in Japanese Patent Application Laid-Open Publication No. H10-260,086 is cited. The main point is a buffer made of a polyolefin bead foam having specific characteristics and having an L-shaped cross section and a plurality of substrate insertion grooves provided inside along the L-shape. In packing the glass substrates, 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 inserted into the substrate insertion grooves of the buffer, and are orthogonal to the substrate surface. The four sides of the rectangular parallelepiped to be fitted are fitted by the buffer, and further fixed with a fixing tool such as rubber or tape as necessary.

[0005]

However, when a fixing member such as rubber or tape is fixed to the outside of the shock absorber, the fastening force is concentrated on the corner of the shock absorber, so that the L-shape is opened. At both ends, the glass substrate may come off from the substrate insertion groove, and the protection function may not work sufficiently.

Another problem is that the outermost two of the plurality of glass substrates packed in the buffer are open, so that the clean glass surface is damaged or contaminated during handling. Yes, the outer two glass substrates are called extraordinary products, so-called dummy substrates, and are distinguished from normal products. This dummy substrate cannot be subjected to secondary processing at the transport destination, and is extremely economical.At the time of the glass substrate removal operation at the time of secondary processing as well, it is necessary to distinguish the normal product and the dummy substrate, which are products, from each other. At present, it is necessary to perform management and improvement is desired.

In the above-mentioned L-shaped buffer, the 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 provided. The glass substrate is fixed using the goodness of the above. Therefore, it is effective for dust 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, and it is impossible. When trying to fit the glass substrate into the substrate insertion groove, the glass substrate which is extremely thin as about 0.6 to 0.8 mm easily bends and breaks easily,
There is a problem that it takes a long time to work carefully to avoid damage. This is the same when taking out the glass substrate. In recent years, in particular, automatic storage and removal devices for glass substrates have been introduced from the point of labor saving, but problems have occurred due to the above problems, and it is pointed out that the buffer is not suitable for automation as a real problem. There is also.

Furthermore, when the glass substrate is inserted into the substrate insertion groove, there is a potential problem that fine scratches are generated on the surface of the glass substrate due to frictional resistance.

The suitability for automation is a practical characteristic that is increasingly gaining importance with the recent increase in the size of glass substrates.
The size of the shock absorber has also been increased, and in the conventional shock absorber, the problems of warpage and deformation have become apparent.

In view of the above problems, the object of the present invention is to prevent the groove of the glass substrate at the end of the L-shape of the buffer from slipping when packing the glass substrate, and to apply an external force such as vibration or drop impact during transportation or handling. Even to provide a glass substrate buffer that can safely protect the glass substrate,
Furthermore, it is suitable for automatic packing and unloading of glass substrates, does not easily generate dust even when rubbed against glass substrates, can be used multiple times with excellent durability, and does not require dummy glass. Another object of the present invention is to provide a buffer for a glass substrate which is economically superior, and to provide a package packed using the buffer.

[0011]

The first aspect of the present invention is a buffer for a glass substrate comprising an in-mold molded article of polyolefin-based resin expanded particles, the cross section of which has an L-shape according to the shape of the corner of the glass substrate. A main body provided with a plurality of substrate insertion grooves for fixing two side ends forming corners of the glass substrate on the inner side along the L-shape, and provided on both sides forming an L-shape of the main body, respectively. A side wall parallel to the substrate insertion groove and extending over the entire length of the L-shape, wherein the side wall is opposed to a corner of the rectangular L-shape having two sides forming a contact with the main body. A portion having a notch of a straight line or a convex arc on the outside is provided, and its area exceeds 80% of the area of the rectangle and is 99%.
The average particle diameter of the foamed particles of the molded article is as follows.
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 60% or more.

In the above-mentioned shock absorber, the maximum thickness of the main body is 10 to 100 mm, the ratio of the two sides of the L shape of the main body is 1.0 to 3.5 based on the short side, and the thickness of the side wall is 10 to 100 mm. The groove width of the substrate insertion groove is 1.0 to 4.0 times the thickness of the glass substrate,
It is preferable that the groove depth is 3 to 15 mm and the groove pitch is 6 to 100 mm.

A second aspect of the present invention is to form a rectangular parallelepiped by arranging a plurality of glass substrates in parallel at a predetermined interval, and to form corners of each of the substrates into the substrate insertion grooves of the buffer for a glass substrate of the present invention. And the four sides of the rectangular parallelepiped orthogonal to the substrate surface are fitted with the buffer, and a long fixing tool is wound around the outside of the buffer, fastened, and fixed. Package.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A buffer according to the present invention has an L-shaped groove having a substrate insertion groove for fixing two ends forming a corner of a glass substrate.
The present invention is characterized in that wide side walls are attached to both side ends of the V-shaped main body. Thereby, in the package using the buffer of the present invention, the surface of the outermost glass substrate is widely covered by the side wall to prevent contamination and damage, and at the same time, the L-shape of the main body is fixed by the side wall. , L is prevented from spreading.

Hereinafter, the buffer of the present invention will be described with reference to embodiments.

FIG. 1 is a perspective view of a preferred embodiment of a buffer according to the present invention. In the figure, reference numeral 1 denotes a buffer of the embodiment, 2 denotes a main body, 3 denotes a substrate insertion groove, 4 denotes a side wall, and 5 denotes a side wall. Is a fixture guide groove, and 6 is a notch.

The basic structure of the shock absorber according to the present invention is as follows: a main body 2 having an L-shaped cross section according to the shape of the corner of the glass substrate;
The main body 2 includes a pair of opposing side walls 4 attached to both ends of the L-shape. The body 2 is provided with a plurality of substrate insertion grooves 3 for fixing two ends forming the corners of the glass substrate on the inner side along the L-shape, and the side wall 4 is formed in parallel with the substrate insertion grooves 3. Is done.

The side wall 4 according to the present invention is formed over the entire length of the L-shape of the main body 2.
In this case, a notch 6 is provided at a corner of the main body 2 which is opposite to the L-shaped corner of the main body 2. The shape of the notch 6 may be a straight arc as shown in FIG. 1 or may be an arc that is convex outward, and the size of the side wall 4 is more than 80% of the area of the rectangle and 99% or less. To adjust.

FIG. 2 is a perspective view of a package in which a glass substrate is packed by using the buffer of FIG. In the figure, 11 is a glass substrate and 12 is a fixture. As shown in FIG. 2, the buffer 1 of the present invention is basically used in groups of four, a plurality of glass substrates 11 are arranged in parallel at a predetermined interval to form a rectangular parallelepiped, and the corners of each substrate are buffered. The rectangular parallelepiped is inserted into the board insertion groove of the body 1 and four sides of the rectangular parallelepiped are fitted with the buffer 1. After that, the long fixture 1 is inserted into the fixture guide groove 5 formed outside the buffer body 1.
2 is wound and fastened and fixed. In the shock absorber of the present invention, the fixture guide groove 5 may be formed as needed.

In the shock absorber 1 of the present invention, as shown in FIG. 1, the L-shape is fixed by the side wall 4 by providing the wide side wall 4 over the entire length of the L-shape. Since the rigidity of the fixing member 12 is improved, even if the fastening force of the fixing tool 12 acts intensively on the corners of the L-shape in the package packed as shown in FIG. The groove of the substrate at the L-shaped end is prevented from slipping.

Further, as shown in FIG. 2, since the surface of the outermost glass substrate 11 is covered with the wide side wall 4, the contamination and damage thereof are greatly suppressed. Further, since the notch 6 is formed at a diagonal portion of the side wall 4 opposite to the L-shaped corner portion, the side wall 4 is unlikely to be warped at the diagonal portion, and contact with the glass substrate 11 is prevented. Is suppressed.

The buffer of the present invention is an in-mold molded article of polyolefin resin expanded particles. The molded body, after filling the polyolefin resin foamable particles in a mold, heating,
It is formed by foaming to expand the expanded particles and molded into a desired shape. The mold used for the molding is inexpensive with a production cost of 1/10 or less even in a complicated shape as compared with an injection mold. Since a compact having a complicated shape can be mass-produced easily and efficiently with high dimensional accuracy, it is economical and suitable for mass production.

Further, in the in-mold molded article of the polyolefin resin foamed particles, minute dust is generated in a very small amount even when the glass substrate is rubbed, and contamination of the glass substrate by the dust is extremely small. Further, the molded body is hardly deformed even when subjected to an external force during handling operation or transportation, and even if deformed, has excellent recoverability and high dimensional stability. Further, when the buffer is repeatedly used, it is washed with pure water each time before use, but the molded body has a small water absorption and is excellent in drying property.

The polyolefin resin used in the buffer of the present invention may be of 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, polyethylene with a metallocene catalyst, polyethylene resin typified by ethylene-vinyl acetate copolymer resin, and copolymerization of propylene with ethylene, butene-1,4-methylpentene-1, etc. It is preferably selected from a random and block copolymer resin, or a composition containing two or more of the above.

Particularly suitable resin materials for the present invention include random copolymers of polyethylene and propylene having a resin density of 0.927 to 0.970 g / cm ³ . Polyethylene having a resin density of 0.927 g / cm ³ or more has an appropriate compression elasticity index of a buffer described later, and is hardly deformed when an external force is applied. Further, it is not necessary to reduce the expansion ratio of the expanded particles in order to obtain a specific compression elasticity index, which is preferable from the viewpoint of lightness and economy. In addition, polyethylene having a resin density of 0.970 g / cm ³ or less is preferable because it has sufficient flexibility and dust resistance and recovery properties are appropriate. Further, the random copolymer resin of propylene has a high compression elasticity index and also has excellent recoverability and durability upon repeated use, and is most preferably used in the present invention.

In the molded article constituting the buffer of the present invention, the average particle diameter of the expanded particles is 1.5 to 5.0 mm, the fusion ratio is 70% or more, the compression elasticity index is 3.9 to 490, and the recovery is The rate is 60% or more.

As described above, the average particle size of the expanded particles is 1.5 to 5.0 mm, and preferably 2.0 to 4.5 mm.
mm. The average particle diameter of the expanded particles is 1.5 mm to 5.
In the case of 0 mm, the foamed particles can be filled into the fine portion of the substrate insertion groove at the time of molding, and the reproducibility of the mold shape and dimensions is good. Further, since the ratio of the surface area per foamed particle (volume) is small, and the gas pressure (air) dissipating property in the particle is small in the steam heating step at the time of in-mold molding, sufficient foaming expandability is exhibited. As a result, voids are less likely to be generated between the foamed particles constituting the in-mold molded body, and there is no possibility that dust enters into the voids and the cleanliness of the buffer cannot be maintained, which is preferable.

The average particle diameter of the foamed particles constituting the buffer of the present invention is defined as a length of 100 mm on the surface of the molded article in the mold.
Are marked with a ballpoint pen, the number of foamed particles in contact with the straight line is measured, and the average particle diameter C [mm] is calculated from the following equation (A). Note that the evaluation is an average of the values obtained by three straight lines.

C = (1.626 × L) / N (A) L: center line length [mm] N: number of particles

The fusion rate of the molded article according to the present invention is defined as the thickness at the fracture surface when a cut having a depth of about 1 mm is made in the thickness direction of the buffer, and the cut is made outside and the sheet is bent and fractured. It is a numerical value indicating the number of foamed particles that are broken (material destruction) with respect to the total number of foamed particles in the area extending over the entire length in the direction and the length of about 75 mm in percentage. In the shock absorber of the present invention, sufficient mechanical strength is obtained when the fusion rate is 70% or more, and when the fastener is fastened by the fastener, the fastener bites into the buffer to break the buffer. In addition, problems such as the buffer being easily chipped are less likely to occur. Further, the problem that micro voids are generated between the foamed particles and water absorption due to a capillary phenomenon is developed is preferable because the fusion rate is less likely to occur at 70% or more.

Further, when the compression elasticity index of the molded body is 3.9 or more, the shock absorber is less likely to be deformed even when subjected to an external force, so that the durability is good and the size of the glass substrate is 600 mm. Even with a large size exceeding 700 mm, permanent distortion due to the weight of the glass substrate hardly occurs, and fixing of the glass substrate is easy, which is preferable. Further, when the compression elasticity index is 490 or less, it is not necessary to particularly reduce the expansion ratio of the shock absorber, which is preferable in terms of lightness and economy. Further, when the compression elasticity index is in the range of 490 or less, the flexibility is good, the dust generation resistance is excellent, and the shock absorbing performance such as a drop impact is also excellent.

The compression elasticity index according to the present invention is a value obtained by dividing the compression elasticity [N / cm ² ] by the expansion ratio.
The compression elastic modulus is a value obtained in accordance with JIS K 7220 for a test piece having the following expansion ratio, and the compression speed is 10 mm / min. When the thickness of the test piece is less than 20 mm, a plurality of test pieces are measured so that the thickness becomes about 20 mm.

Method for measuring compression ratio: width 50 from buffer
mm, length 50 mm, cut out a flat test piece of thickness 20 mm, measure the weight [g] up to 10 mg, measure the width, length, thickness with calipers, calculate the volume [cm ³ ],
The expansion ratio E [cm ³ / g] is calculated from the following equation (B).

E = volume / weight [cm ³ / g] (B)

When the compression elasticity index is in the range of 3.9 to 490 and the recovery rate is 60% or more, the in-mold molded article of the expanded polyolefin resin particles has good repetition durability. Even if the frequency of use is high, the deformation is small, which is preferable. In addition, the recovery rate is 5 times wider than the buffer.
A flat test piece having a thickness of 0 mm, a length of 50 mm, and a thickness of 20 mm was cut out, and the thickness of the test piece was reduced to 50 mm at a compression speed of 10 mm / min using a compression tester “Autograph AG-5000D” manufactured by Shimadzu Corporation. %, Immediately remove the load at the same speed until the load becomes zero, measure the thickness at the moment when the load becomes zero, and calculate the recovery rate R [%] from the following formula (C).
Is calculated. In addition, when the thickness of a test piece is less than 20 mm, a plurality of test pieces are measured so as to have a thickness of about 20 mm.

R = (T ₁ / T ₀ ) × 100 [%] (C) T ₀ : thickness of test piece before test [mm] T ₁ : thickness of test piece after test (load is zero) At the time) [m
m]

Next, the outer dimensions of the shock absorber of the present invention will be described in detail with reference to FIGS. FIG. 3 is a partial cross-sectional view in a direction orthogonal to the L-shape of the main body in the embodiment of the shock absorber of the present invention, and FIG. 4 is a side view of the embodiment of FIG. In FIG. 3, reference numeral 13 denotes a ridge that separates the adjacent substrate insertion grooves 3, 22 denotes a bottom of the substrate insertion groove 3, and 23 denotes a top of the ridge 13. In FIG. It is a buffer plate to be formed, and forms a short side and a long side of an L-shape, respectively. 22a and 22b are buffer plates 21a and 2b.
These are the bottoms of the substrate insertion grooves respectively formed in 1b, and correspond to 22 in FIG. In addition, 23a and 23b correspond to 2 in FIG.
The top of the ridge between adjacent substrate insertion grooves, which corresponds to No. 3.

As shown in FIG. 4, the shock absorber of the present invention has a substantially L-shaped cross section, and the maximum thickness of the shock-absorbing plates 21a and 21b (see FIG. 3). , T ₁ ), and the thickness of the side wall 4 depend on the size of the target glass substrate, but are preferably selected from the range of 10 to 100 mm, more preferably 15 to 50 mm. When the thickness is within the above preferred range, the rigidity of the cushioning member is sufficient, warpage or deformation hardly occurs, and a sufficient L-shaped restraining force is obtained on the side wall 4. Also,
Within the above range, the productivity of the buffer is good, the bulk of the buffer and the package are appropriate, and the economy is good. The buffer plates 21a, 2b at the bottoms 22a, 22b of the substrate insertion groove 3
The thickness of 1b is preferably 5 mm or more in order to obtain the above-mentioned effects.

In the shock absorber of the present invention, the L
The ratio (t _L / t _S ) of the short side (t _S ) and the long side (t _L ) of the character based on the short side is preferably from 1.0 to 3.5, more preferably from 1.0 to 3.5. .3. When the ratio is within the above range, the balance between the long side and the short side is good, the fixing stability of the rectangular glass substrate is good, and the glass substrate is less likely to be damaged by bending.

In the present invention, in order to prevent the glass substrate from being contaminated and damaged, it is preferable that the surface of the glass substrate be covered with the side wall of the buffer as widely as possible.
Therefore, within the range between the short side and the long side, the length of the side end supported by the two shock absorbers at each side end of the glass substrate during packing is preferably 50% or more, more preferably. 70% or more. When the length of the side edge of the glass substrate supported by the buffer is 50% or more, the glass substrate is less likely to be damaged even if an impact load is concentrated on the supporting portion when a drop impact is received, and the glass substrate surface Can be widely covered and protected, which is preferable. Further, the stress applied to the buffer body is lower than that of the glass substrate, and the generation of dust due to contact friction due to vibration during transportation is reduced, which is desirable from the viewpoint of cleanliness.
Further, since a slight gap is required between the two buffers supporting each side edge of the glass substrate, the length of the side edge supported by the two buffers at each side edge is 98% or less. Is preferred.

Further, the side wall 4 of the buffer of the present invention is
In order to cover and protect the glass substrate, it is preferable that the width is large. Also, in consideration of the provision of the notch 6, the area of the side wall 4 [the area removed by the notch 6 from the rectangular area (t _a × t _b )] Is the area of the rectangle 80
% To 99% or less.

As the specific external dimensions, preferably,
Short sides (t _S) is 100 to 500 mm, long side (t _L) is 10
0 to 1100 mm, and the length in the direction orthogonal to the L-shape depends on the number of glass substrates packed, but is 150 to 600 mm.
It is.

Next, the substrate insertion groove 3 will be described with reference to FIG. In the buffer member of the present invention, the groove width t ₃ of the plurality of board insertion groove 3 provided on the main body 2 is preferably 1.0 to 4.0 times the thickness of the glass substrate for packing, more preferably 1.2 ~ 3.5 times. When the value is 1.0 times or more, the workability at the time of manually inserting and removing the glass substrate is good, and the glass substrate is less likely to be damaged even when automatic insertion is performed. At a ratio of 4.0 times or less, there is no problem even if the glass substrate is automatically inserted and removed, and there is no play due to vibration and impact during the transportation of the glass substrate, thereby preventing damage to the glass substrate. It is preferable from the viewpoint of cleanliness because it generates less dust.

The groove depth t ₂ of the substrate insertion groove 3 is preferably in the range of 3 to 15 mm in consideration of the size and weight of the glass substrate, the compression elasticity index of the molded body, and the like. 3m groove depth
When the glass substrate is at least m, the glass substrate is not easily detached and damaged even when subjected to a vibration impact during transportation or a drop impact during handling. Also, near the side edge of the glass substrate in contact with the buffer, fine abrasions are apt to occur due to rubbing due to vibration and impact during transportation, and when processing the glass substrate, the region is cut and removed, but the substrate is inserted. It is preferable that the depth of the groove 3 be 15 mm or less, since the area to be cut and removed can be small. In addition, dust generation due to friction between the glass substrate and the buffer is reduced, which is desirable from the viewpoint of cleanliness.

Further, the groove pitch t ₄ of the substrate insertion groove 3 is
In view of the type of the glass substrate (for example, a display component substrate such as a mother glass or a color filter glass substrate) and the size and weight thereof, the compression elasticity index of the molded product, the groove width, and the like, it is preferably selected in the range of 6 to 100 mm. I just need. In other words, it is sufficient to set the glass substrate to bend so that the substrates do not come into contact with each other when receiving a vibration impact during transportation or a drop impact during handling.

As shown in FIG. 3, the cross-sectional shape of the substrate insertion groove 3 provided in the buffer of the present invention is such that the groove width t ₃ is the same at the bottom and the opening, that is, between the adjacent substrate insertion grooves. The shape of the ridge 13 may be rectangular (a), but in consideration of the workability of inserting the glass substrate, the groove width of the substrate insertion groove 3 is increased at the opening, that is, the top cross section of the ridge 13 is reduced. An upwardly convex arc shape (b) or trapezoidal shape (c) is preferable.

The buffer of the present invention has four
After packaging the glass substrate, a long fixing device is wound around the glass substrate, fastened and fixed to form a package. The fixing tool used here may be a long one such as a string or a tape, and for example, a polypropylene tape is preferably used. In addition, the package is usually housed in a clean polyethylene bag or the like, sealed, stored, and transported so that dust does not intrude from the outside.

Also, in the embodiment of FIG. 2, an example is shown in which the same buffer is used in a set of four, but the present invention is not limited to this, and the size, packing, unloading workability, In particular, in the case of an automatic device, two types of shock absorbers of different sizes may be used in combination in consideration of takeout positioning and the like. For example, there is a combination in which a large-size buffer is used for a bottom portion to which a load is applied, and a small-size buffer is used for the upper portion. In addition, it is not always necessary to make the short side of the buffer correspond to the short side of the glass substrate. For two buffers supporting one side of the glass substrate, even if one is a combination of the short side and the other is the long side. I do not care.

The buffer of the present invention can be used not only for transporting a glass substrate but also for storage. Specifically, the buffer of the present invention is fixed in a pair in an outer box such as a plastic cardboard, and a glass substrate is inserted. In this case, the buffer on the glass substrate may or may not be used. In addition, a cover is used as necessary to prevent dust from entering.

[0050]

EXAMPLES A buffer having the following specifications was prepared, and a glass substrate was packed and evaluated.

(Example 1) [Glass substrate specification] Use: Mother glass for liquid crystal display Dimension: 850 mm × 1000 mm Thickness: 0.7 mm

[Resin Properties] Material: ethylene / propylene random copolymer resin Expansion ratio: 20 cm ³ / g Average particle size: 3.6 mm Fusing rate: 88% Compressive elasticity: 559 N / cm ² Compressive elasticity: 28. 0 Recovery rate: 88%

[External Dimensions] Number of glass substrates accommodated: 12 Main body Short side: 430 mm Long side: 460 mm Length in L-shape orthogonal direction: 415 mm Thickness: 35 mm Side wall Shape: FIG. 1 (straight cutout) Area: 85% of rectangle Thickness: 35mm Board insertion groove Groove width: 1.5mm Groove depth: 9.5mm Groove pitch: 25mm Shape: Fig. 3 (c), height of straight part 5.0mm, height of trapezoid part 4.5mm

[Evaluation 1] Twelve glass substrates were packed as a set of four buffers, and a polypropylene tape was wound at two places as a fixture, fastened and fixed to obtain a package. When this package was transported along a normal route, there was no warping or deformation at the L-shaped end of the buffer, the workability of packing the glass substrate was good, and the L-shape was maintained and the glass substrate in the package was maintained. The grooves were not displaced and could be transported stably.

[Evaluation 2] Further, in order to evaluate the cushioning performance of the shock absorber of this embodiment, the package of the above evaluation 1 was packed in a cardboard box (CD-4 of JIS Z 1506 standard), and A free-fall test was performed depending on the conditions. -Drop test conditions Drop height: 30 cm Package drop surface: Only the ground of the package Drop frequency: 3 times

Under the above conditions, the glass substrate did not fall off even after falling three times, and the packing state before the test was maintained.
No damage to the glass substrate was observed. Further, when the surface of the glass substrate was visually observed, no adhesion of dust was observed at all.

[Evaluation 3] Further, in order to evaluate the glass substrate fixing performance of the buffer of the present invention, a vibration test was performed on the package of Evaluation 1 under the following conditions. In the vibration test, the package was fixed to a vibration table of a vibration test device,
The test was performed in accordance with the test method of SZ0232. -Vibration test conditions Vibration direction: Up and down Vibration waveform: Sine wave Sweep: Logarithmic sweep (frequency: 5 to 100 Hz, sweep speed:
0.5 octave / min) Vibration acceleration: ± 0.75G Vibration time: 30 minutes

After completion of the vibration test, when the packing state of the glass substrate was visually observed, although the glass substrate was found to be slightly loose, none of the glass substrates dropped out of the substrate insertion groove and the dust was visually observed. No adhesion was observed.

(Comparative Example 1) A buffer body having only the main body without the side wall having the following specifications was prepared, and a glass substrate was packed and evaluated.

[Glass substrate specification] Same as in the first embodiment.

[Resin Properties] Material: Ethylene / propylene random copolymer resin Expansion ratio: 20 cm ³ / g Average particle size: 3.6 mm Fusing rate: 86% Compression elasticity: 549 N / cm ² Compression elasticity index: 27. 5 Recovery rate: 87%

[External dimensions] Number of glass substrates accommodated: 12 Main body Short side: 430 mm Long side: 460 mm Length in L-shaped orthogonal direction: 400 mm Thickness: 35 mm Same as in the first embodiment.

[Evaluation] A package was obtained in the same manner as in Evaluation 1 of Example 1, except that the above four buffers were used as a set. When the obtained package was transported along the same route as in Example 1,
Warping and deformation were often observed at the L-shaped end of the buffer. Also,
Since the L-shape was opened by the fastening force of the fixture and the five glass substrates were displaced from the substrate insertion groove by about 1 to 3 mm in the vicinity of the L-shaped end, the same evaluations 2 and 3 as in Example 1 were performed. Could not be implemented.

Example 2 A buffer was prepared in the same manner as in Example 1 except that a resin having the following physical properties was used.

[Resin Properties] Material: ethylene / propylene random copolymer resin Expansion ratio: 7 cm ³ / g Average particle size: 2.9 mm Fusing rate: 78% Compressive elasticity: 2940 N / cm ² Compressive elasticity index: 420 Recovery Rate: 78%

Using the above buffer, a package was formed and transported in the same manner as in Example 1. As a result, both the packing workability and transportability were good.

Comparative Example 2 A buffer was produced in the same manner as in Example 1 except that a resin having the following physical properties was used.

[Resin Properties] Material: ethylene / propylene random copolymer resin Expansion ratio: 30 cm ³ / g Average particle size: 4.8 mm Fusing rate: 98% Compressive elasticity: 98 N / cm ² Compressive elasticity index: 3. 3 Recovery rate: 92%

As a result of forming and transporting a package in the same manner as in Example 1 using the above-mentioned buffer, the buffer is compressed and deformed by the fastening force of the fixing tool, and the glass substrate is bent to be normal. Could not be packed.

[0070]

As described above, in the present invention, the provision of the wide side walls in the shock absorber improves the rigidity and increases the L-shaped restraining force of the main body. Therefore, in the package in which the glass substrate is packed using the buffer, deformation of the buffer is prevented, the groove of the glass substrate at the L-shaped end is not displaced, and the glass substrate is securely fixed and protected. In addition, generation of dust and damage to the glass substrate due to sliding friction between the glass substrate and the buffer are prevented. Further, since the outermost glass substrate surface is widely covered with the side walls to prevent dust adhesion and damage, a dummy substrate is not required. Therefore, according to the present invention, the protection effect of the glass substrate is high,
Good packaging and removal workability, suitable for automation of the work, and a reusable buffer that does not require a dummy substrate is provided, greatly improving the economic efficiency in packing, storing and transporting glass substrates. Can be done.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of a buffer according to the present invention.

FIG. 2 is a perspective view of one embodiment of the package of the present invention using the buffer of FIG. 1;

FIG. 3 is a schematic partial cross-sectional view showing an example of a shape of a substrate insertion groove of the buffer of the present invention.

FIG. 4 is an explanatory diagram of external dimensions of the shock absorber of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Buffer 2 Main body 3 Board insertion groove 4 Side wall 5 Fixture guide groove 6 Notch 11 Glass substrate 12 Fixture 13 Protrusion 21a, 21b Buffer plate 22, 22a, 22b Bottom portion 23, 23a, 23b of substrate insertion groove Top of

(72) Inventor Toshio Yamazaki 1-2-1, Yurakucho, Chiyoda-ku, Tokyo Asahi Kasei Corporation (72) Inventor Hiroto Shibata 5-5-2, Wakabayashi-ku, Wakabayashi-ku, Sendai City, Miyagi Pref. In-house F term (reference) 3E066 AA05 CA01 DA01 FA13 HA04 NA30 NA43 3E096 AA06 BA15 BA24 BB05 DA05 DB01 DC02 EA02 FA03 FA09 FA10 FA16 FA20 FA31 GA11

Claims (3)

[Claims] 1. A buffer for a glass substrate comprising an in-mold molded article of polyolefin-based resin expanded particles, wherein the cross-section has an L-shape according to the shape of a corner of the glass substrate, and an inner portion is formed along the L-shape. A main body provided with a plurality of substrate insertion grooves for fixing the two side ends forming the corners of the glass substrate; and an L-shaped parallel to the substrate insertion groove provided at both ends of the main body forming an L-shape. A side wall extending over the entire length, wherein the side wall is a straight line or an outwardly protruding arc at a corner corresponding to the corner of the rectangular L-shaped corner having two end sides that make contact with the main body. The area of which is more than 80% and 99% or less of the area of the rectangle, the average particle diameter of the foamed particles of the molded body is 1.5 to 5.0 mm, and the fusion ratio is Is 70%
As described above, the compression elasticity index is 3.9 to 490, and the recovery rate is 60%.
A buffer for a glass substrate as described above. 2. The shock absorber according to claim 1, wherein a maximum thickness of the main body is 10 to 100 mm, a ratio of two sides of the L shape of the main body is 1.0 to 3.5 on a short side basis, and a thickness of a side wall is 10 to 100 mm. The groove width of the substrate insertion groove is 1.0 to 4.0 times the thickness of the glass substrate,
The buffer according to claim 1, wherein the groove depth is 3 to 15 mm and the groove pitch is 6 to 100 mm. 3. A rectangular parallelepiped is formed by arranging a plurality of glass substrates in parallel at predetermined intervals, and each corner of each substrate is inserted into a substrate insertion groove of the glass substrate buffer according to claim 1 or 2. A package body characterized in that four sides of the rectangular parallelepiped orthogonal to the substrate surface are fitted with the buffer, and a long fixing device is wound around the outside of the buffer and fastened and fixed. .