JP2016003165A - Production method of glass article, and glass article with film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of producing properly a glass article.SOLUTION: A film deposition part 11b comprising a plurality of re-peelable protection film pieces 11a and a film non-deposition part 11c on which the protection film piece 11a is not formed are formed on at least either of first and second principal surfaces 10a, 10b of a glass preform 10 having the first and second principal surfaces 10a, 10b. The glass preform 10 provided with the protection film pieces 11a is parted, to thereby obtain a glass article 1 having the protection film pieces 11a.

Description

  The present invention relates to a method for producing a glass article and a glass article with a film.

  Conventionally, a glass plate is used as a front plate of various electronic components such as a mobile phone, a smartphone, and a liquid crystal panel. When manufacturing the glass plate, it is necessary to prevent the glass plate from being damaged.

  For example, Patent Document 1 describes a method for forming a planar protective film by adhering a water and polymer solution to at least one main surface of a glass sheet at 200 ° C. or higher as a method for protecting a glass sheet. Has been.

JP 2000-86296 A

  As described in Patent Document 1, when a polymer protective film is formed on at least one main surface of a glass plate, it may be difficult to suitably cut the glass plate by a scribe method or the like. Specifically, when the glass plate is scribed and cut by scribing, the protective film remains undivided and the glass plate may not be separated. In particular, the protective film on the main surface opposite to the main surface on which the scribe line is formed is difficult to cut. Further, if the cut glass plates are separated from each other in a state where the protective film is not cut, most of the protective film may be peeled off from the main surface of the glass plate at an unintended timing. Therefore, the productivity of the glass article may be reduced, the glass plate may be damaged, or the main surface of the glass plate may be contaminated.

  A main object of the present invention is to provide a method that can be easily cut while protecting a main surface of a glass plate and that can suitably manufacture a glass article.

  In the first method for producing a glass article according to the present invention, a plurality of removable protections on at least one of the first and second main surfaces of the glass base material having the first and second main surfaces. A film forming part made of a film piece and a non-film forming part in which no protective film piece is formed are formed. The glass base material provided with the protective film piece is divided to obtain a glass article having the protective film piece.

  According to such a configuration, since the plurality of protective film pieces are separated and independent from each other so as to be divided into non-film-forming parts, the film-forming part can be easily divided when the glass base material is cut. Therefore, it is possible to suppress the cutting failure of the glass base material due to the cutting failure of the film forming portion. Moreover, it can suppress that most of a film-forming part peels at the time of a cutting | disconnection of a glass base material.

In the first method for producing a glass article according to the present invention, it is preferable that the film forming section is constituted by a continuous pattern of a plurality of protective film pieces having a predetermined shape.
According to such a structure, the space | interval of a protective film piece can be equalized easily, and the main surface of a glass article can be protected more reliably.

  In the first method for producing a glass article according to the present invention, the plurality of protective film pieces include a plurality of protective film piece rows each having a plurality of protective film pieces arranged at intervals in one direction. The plurality of protective film piece rows are arranged at intervals from each other along the other direction, and in the protective film piece row adjacent to the other direction, in one direction of the protective film pieces The positions are preferably offset from each other.

  According to such a configuration, for example, the main surface of the glass article can be suitably protected against scratching from a direction crossing one direction, and the occurrence of defects such as linear scratches can be suppressed.

  In the first method for producing a glass article according to the present invention, the plurality of protective film pieces include a plurality of protective film pieces having a plurality of protective film pieces spaced apart from each other along the other direction. The plurality of protective film pieces are arranged at intervals in one direction, and in the protective film pieces adjacent to one direction, in the other direction of the protective film pieces. The positions are preferably offset from each other.

  According to such a configuration, for example, the main surface of the glass article can be suitably protected against scratching from all directions, and the occurrence of defects such as linear scratches can be suppressed.

  In the first method for producing a glass article according to the present invention, in the step of dividing, the glass base material provided with the protective film piece is formed into a straight line to be cut across the film forming part and the non-film forming part. It is preferable to divide along.

  According to such a configuration, it is possible to easily divide the film forming unit while suppressing damage to the glass article in the vicinity of the planned cutting line.

  In the first method for producing a glass article according to the present invention, the protective film piece is provided on both the first main surface and the second main surface, and the protective film piece provided on the second main surface is the first. It is preferable to divide the glass base material by applying a tensile stress to the microcracks after forming the microcracks by scribing the first main surface and making it smaller than the protective film piece provided on the main surface.

  According to such a structure, the area of the 2nd main surface exposed when the protective film piece located on a cutting projected line peels can be restrained small. Therefore, the second main surface in the vicinity of the cut surface can be suitably protected.

  In the first method for producing a glass article according to the present invention, the shape of each of the plurality of protective film pieces may be a hexagon, a circle, or an ellipse.

  According to such a configuration, peeling of the protective film piece can be suppressed. Moreover, the protective film piece can be easily formed as a continuous pattern.

  In the second glass article manufacturing method according to the present invention, a plurality of removable protections on at least one of the first and second main surfaces of the glass base material having the first and second main surfaces. A thin film portion thinner than the protective film piece is provided in a releasable manner in a film forming portion composed of the film piece and an area where the protective film piece is not formed. The glass base material provided with the protective film piece is divided to obtain a glass article having the protective film piece.

  The first film-coated glass plate according to the present invention is provided on a glass plate having a first main surface and a second main surface, and at least one of the first and second main surfaces, A film-forming part composed of a plurality of removable protective film pieces and a non-film-forming part in which no protective film pieces are formed are provided.

  The second film-coated glass plate according to the present invention is provided on at least one of the glass plate having the first main surface and the second main surface and the first and second main surfaces. A film forming unit composed of a plurality of peelable protective film pieces, and a thin part thinner than the protective film piece is provided in a region where the protective film pieces are not formed so as to be removable again.

  ADVANTAGE OF THE INVENTION According to this invention, it can cut | disconnect easily, protecting the main surface of a glass plate, and the method which can manufacture a glass article suitably can be provided.

It is a typical sectional view of a glass board with a film in one embodiment of the present invention. It is a top view of the surface side of the glass plate with a film in one embodiment of the present invention. It is a top view of the back surface side of the glass plate with a film in one embodiment of the present invention. It is a top view of the surface side of the glass article manufactured in one Embodiment of this invention. It is a top view of the back surface side of the glass article manufactured in one Embodiment of this invention. It is a typical top view of a glass board with a film in the 1st modification. It is a typical top view of a glass board with a film in the 2nd modification. It is a typical sectional view of a glass board with a film in the 3rd modification. It is a typical sectional view of a glass board with a film in the 4th modification.

  Hereinafter, an example of the preferable form which implemented this invention is demonstrated. However, the following embodiment is merely an example. The present invention is not limited to the following embodiments. Moreover, in each drawing referred in embodiment etc., the member which has a substantially the same function shall be referred with the same code | symbol. The drawings referred to in the embodiments and the like are schematically described. A ratio of dimensions of an object drawn in a drawing may be different from a ratio of dimensions of an actual object. The dimensional ratio of the object may be different between the drawings. The specific dimensional ratio of the object should be determined in consideration of the following description.

  In the present embodiment, a method for producing glass articles 1α and 1β will be described with reference to FIGS.

  First, the glass base material 10 (refer FIG. 1) used as the original plate of the glass articles 1α and 1β is prepared. The material of the glass base material 10 may be arbitrarily selected. For example, the glass base material 10 may be tempered glass or non-alkali glass. Moreover, the glass base material 10 may consist only of a glass material, and may have a glass material and the thin film etc. which were formed on the glass material. Moreover, the glass base material 10 may be a laminated glass obtained by laminating a plurality of glass materials, resin materials, adhesives, and the like. In the present embodiment, the glass base material 10 has a flat plate shape. However, for example, the glass base material 10 may have a curved plate shape or a plate shape having a bent portion.

  The glass base material 10 has the 1st main surface 10a and the 2nd main surface 10b which are mutually in a front-and-back relationship. The thickness of the glass base material 10 can be appropriately set according to the thickness of the glass article 1 to be manufactured. The thickness of the glass base material 10 can be about 0.1-2.0 mm, for example.

  Next, it forms into a film on the 1st and 2nd main surface 10a, 10b of the glass base material 10, and the glass plate 100 with a film | membrane is obtained. Specifically, a first film forming portion 11b including a plurality of protective film pieces 11a is provided on the first main surface 10a of the glass base material 10 so as to be peelable. On the 2nd main surface 10b of the glass base material 10, the 2nd film-forming part 12b which consists of a some protective film piece 12a is provided so that peeling is possible. The 1st and 2nd film-forming parts 11b and 12b are films | membranes which protect the main surface of the glass base material 10 and the glass articles 1α and 1β manufactured therefrom, and prevent the main surface from being scratched.

  The plurality of protective film pieces 11a and 12a are spaced apart from each other. Of the first and second main surfaces 10a and 10b, portions where the protective film pieces 11a and 12a (film forming portions 11b and 12b) are not provided are referred to as non-film forming portions 11c and 12c. That is, it can be said that the first and second film forming portions 11b and 12b are divided into a plurality of protective film pieces 11a and 12a by the mesh-like non-film forming portions 11c and 12c.

  The protective film pieces 11a and 12a have, for example, a polygonal shape. Specifically, the protective film pieces 11a and 12a are hexagonal. If the shape of the protective film pieces 11a and 12a is hexagonal, the protective film pieces can be spread at a small interval, and the main surface of the glass base material 10 (glass articles 1α and 1β) can be more reliably protected. The protective film piece may be, for example, a triangle, a quadrangle, a pentagon, a heptagon, an octagon, or the like. If the protective film pieces are polygonal, the gaps between the adjacent protective film pieces can be arranged uniformly, so that cutting and peeling can be performed more stably.

  The protective film pieces 11a and 12a are preferably made of, for example, an elastic film made of an elastic body. The protective film pieces 11a and 12a may be made of a resin film containing, for example, acrylic, polyester, polyurethane, or urethane. As a method of forming the protective film pieces 11a and 12a, any conventionally known method such as a printing method or a spray coating method may be used.

  The thickness of the protective film pieces 11a and 12a is, for example, preferably about 10 to 100 μm, and more preferably 20 to 50 μm. Moreover, it is preferable that the plurality of protective film pieces 11a and 12a have the same thickness. Moreover, it is preferable that the length of the longest part of the protective film pieces 11a and 12a is 5 mm or less, and the length of the shortest part is 0.1 mm or more. Moreover, it is preferable that the space | interval space | interval of each of the protective film pieces 11a and 12a is 0.1-5 mm.

  In the present embodiment, the case where the first and second film forming portions 11b and 12b are each configured by a continuous pattern of a plurality of protective film pieces 11a and 12a will be described as an example.

  Specifically, the plurality of protective film pieces 11a constitute a plurality of protective film piece rows 11d. In the protective film piece row 11d, the plurality of protective film pieces 11a are arranged at intervals along the x-axis direction. The plurality of protective film rows 11d are arranged along the y-axis direction different from the x-axis direction. In the present embodiment, the x-axis direction and the y-axis direction are orthogonal to each other. In the protective film piece row 11d adjacent in the y-axis direction, the position of the protective film piece 11a in the x-axis direction is shifted. That is, the protective film piece rows 11d adjacent in the y-axis direction are provided such that the arrangement period of the protective film pieces 11a is shifted in the x-axis direction. In addition, it is preferable that the protective film piece rows 11d adjacent in the y-axis direction are provided such that the arrangement period of the protective film pieces 11a is shifted by a half period in the x-axis direction. Thus, in this embodiment, the protective film pieces 11a are provided in a staggered manner in the y-axis direction.

  Further, the plurality of protective film pieces 11a constitute a plurality of protective film piece rows 11e. Each protective film piece row 11e has a plurality of protective film pieces 11a. In the protective film piece row 11e, the plurality of protective film pieces 11a are arranged at intervals from each other along the y-axis direction. The plurality of protective film piece rows 11e are arranged along the x-axis direction. In the protective film piece rows 11e adjacent in the x-axis direction, the positions of the protective film pieces 11a in the y-axis direction are shifted. That is, the protective film piece rows 11e adjacent in the x-axis direction are provided such that the arrangement period of the protective film pieces 11a is shifted in the y-axis direction. In addition, it is preferable that the protective film piece rows 11e adjacent in the x-axis direction are provided such that the arrangement period of the protective film pieces 11a is shifted by a half period in the y-axis direction. Thus, the protective film pieces 11a are provided in a staggered manner in the x-axis direction.

  Similar to the protective film pieces 11a, the protective film pieces 12a are also provided in a zigzag pattern in the x-axis direction and the y-axis direction.

  Thus, by providing the protective film pieces 11a in a staggered manner, for example, even when a sharp object contacts the glass base material 10 (glass articles 1α, 1β) linearly, the contact locus is Since the protective film piece 11a is traversed, it is difficult to make a large linear scratch.

  In the present embodiment, a case where the protective film piece 11a provided on the first main surface 10a is larger than the protective film piece 12a provided on the second main surface 10b will be described as an example. The area of the protective film piece 11a is, for example, 1 to 4 times or more the area of the protective film piece 12a.

  In addition, the area ratio of the 1st film-forming part 11b which occupies for the whole 1st main surface 10a (The area | region where the 1st film-forming part 11b was provided, and the whole area | region where the non-film-forming part 11c was provided) is , Preferably 25% to 97%, more preferably 50% to 90%. Similarly, the area ratio of the second film forming unit 12b in the entire second main surface 10b (the entire region in which the second film forming unit 12b and the non-film forming unit 12c are provided) Is preferably 25% to 97%, more preferably 50% to 90%.

  Next, the film-coated glass plate 100 is cut to obtain glass articles 1α and 1β. Specifically, the film-coated glass plate 100 is cut along a planned cutting line L that crosses the first film forming unit 11b and the non-film forming unit 11c. In the present embodiment, the planned cutting line L is linear.

  In the present embodiment, microcracks extending linearly along the planned cutting line L are formed by scribing the first main surface 10a of the glass base material 10 from above the protective film piece 11a. Thereafter, the glass base material 10 is cut by bending the film-coated glass plate 100, for example, by applying tensile stress to the microcracks formed in the glass base material 10 to develop the microcracks. The microcracks may be formed mechanically by running a scribe wheel or the like, or may be formed by an optical device such as a laser.

  By cutting the film-coated glass plate 100 as described above, glass articles 1α and 1β having first and second film forming portions 11b and 12b can be obtained as shown in FIGS. FIG. 4 is a plan view of the glass articles 1α and 1β viewed from the first main surface 10a side. FIG. 5 is a plan view of the glass articles 1α and 1β viewed from the second main surface 10b side. In addition, the said cutting method is an example and you may use arbitrary methods as a cutting method of the glass plate 100 with a film | membrane.

Moreover, many of the protective film pieces 11a located on the planned cutting line L are cut when the first main surface 10a is scribed. As shown in FIG. 4, the cut protective film pieces 11a are separated in a state where they are adhered to the glass articles 1α and 1β.
On the other hand, the second film forming unit 12b formed on the second main surface 10b, which is the back surface of the surface to be scribed, is difficult to be cut during scribing. However, since the 2nd film-forming part 12b is comprised by the some protective film piece 12a each independent, when it isolate | separates into the glass articles 1α and 1β, it can be easily divided. More specifically, when separating the glass article 1α and the glass article 1β, an external force (peeling force) associated with the separation acts on the protective film piece 12a existing on the planned cutting line L. Here, since the protective film pieces 12a are individually independent, no peeling force acts on the protective film pieces 12a formed outside the planned cutting line L. Therefore, the protective film piece 1 existing outside the planned cutting line L is not peeled off, and only the protective film piece 12a existing on the planned cutting line L is peeled off from one glass article 1β and attached to the other glass article 1α. To separate. In this way, the second film forming unit 12b is easily divided along the cutting line L. Accordingly, when the film-coated glass plate 100 is cut, the first film forming unit 11b and the second film forming unit 12b are not peeled off entirely, and the main surface is protected, and the cut line L is cut. Can be easily divided along. That is, it is possible to suppress the occurrence of defects such as scratches on the main surface during the manufacturing process of the glass articles 1α and 1β.

  Even when the protective film piece 11a is not cut at the time of scribing, only the protective film piece 11a on the planned cutting line L is separated when the glass article 1α and the glass article 1β are separated. Since it sticks to either one and can peel from the other glass, it can suppress that the 1st film-forming part 11b peels entirely.

  Note that the first and second film forming portions 11b and 12b may be peeled off from the glass article 1 after the film-coated glass plate 100 is cut. For example, the first and second film forming portions 11b and 12b may be removed by washing with a liquid such as warm water or chemical treatment with a chemical solution. That is, the finally obtained glass article of the present invention may not have a film forming part.

  In the present embodiment, the protective film piece 12a constituting the second film forming unit 12b is smaller than the protective film piece 11a constituting the first film forming unit 11b. For this reason, even if the protective film piece 12a on the cutting planned line L peels at the time of the cutting | disconnection of the glass plate 100 with a film | membrane, the increase in the exposed area of the 2nd main surface 10b becomes relatively small. Therefore, it is possible to suitably protect the second main surface 10b. Further, since the protective film piece 11a is relatively large on the first main surface 10a on which scribing is performed, the unevenness on the planned cutting line L is relatively reduced, and stable scribing is possible. The size of the protective film pieces 11a and 12a is an example, and the protective film piece 11a and the protective film piece 12a may be formed with substantially the same dimensions and the same shape. In this case, since the film forming portions 11b and 12b can be easily formed under the same film forming conditions, the productivity of the film-coated glass plate 100 and the glass articles 1α and 1β can be improved.

  In the above embodiment, the case where the plurality of protective film pieces 11a and 12a are provided in a staggered manner has been described as an example, but the arrangement of the plurality of protective film pieces 11a and 12a may be arbitrarily set. For example, the protective film pieces 11a and 12a may be provided in a matrix or randomly.

(First and second modifications)
FIG. 6 is a schematic plan view of a glass plate with a film in a first modification of the present invention. FIG. 7 is a schematic plan view of a glass plate with a film in the second modification of the present invention. In the above embodiment, an example in which the protective film pieces 11a and 12a are hexagonal has been described. However, in the present invention, the shape of the protective film piece is not particularly limited. For example, as shown in FIG. 6, the glass plate 101 with a film according to the first modification includes a circular protective film piece 21a. Moreover, as shown in FIG. 7, the glass plate 102 with a film of the second modified example includes an elliptical (or oval) protective film piece 31a. If the protective film piece is circular, elliptical, or the like, the protective film piece has no corners, and thus the protective film pieces can be prevented from peeling off from the corners.

  Moreover, you may comprise a protective film by the protective film piece of a different multiple types of shape and magnitude | size. For example, as shown in FIG. 7, the glass plate 102 with a film according to the second modification of the present invention may include an elliptical protective film piece 31a and a circular protective film piece 41a as a film forming unit. . According to such a configuration, since the gap between the protective film pieces can be reduced, the main surface of the glass base material (glass article) can be more reliably protected. In addition, the shape of the above-mentioned protective film piece is an example, and the shape of the protective film piece is the number of contacts to the main surface of the glass article in the manufacturing process of the glass article, the peeling force in the peeling process of the protective film, etc. May be set as appropriate.

(Third Modification)
FIG. 8 is a schematic cross-sectional view of the film-coated glass plate 103 according to the third modification of the present invention. In the above embodiment, the example in which the film forming units 11b and 12b and the non-film forming units 11c and 12c are provided has been described. However, the present invention is not limited to this configuration. For example, instead of providing the non-film forming portions 11c and 12c, thin portions 11f and 12f thinner than the protective film pieces 11a and 12a may be provided. According to such a configuration, the first and second main surfaces 10a and 10b can be protected without a gap. Further, since the plurality of protective film pieces 11a and 12a constituting the film forming parts 11b and 12b are respectively connected by the thin-walled parts 11f and 12f, the protective film pieces 11a and 12a can be more effectively separated at unintended timing. Can be suppressed. Since the thin portions 11f and 12f are configured to be thinner than the protective film pieces 11a and 12a, the first and second film forming portions 11b and 12b are placed in the thin portions 11f and 12f when the film-coated glass plate 103 is cut. Can be easily separated.

  In addition, although FIG. 8 demonstrated the example which provided the thin parts 11f and 12f in both the main surfaces of the glass base material 10, you may provide the thin parts 11f and 12f only in one main surface. For example, when scribing the 1st main surface 10a, the thin part 11f may be provided in the 1st main surface 10a, and the non-film-forming part 12c may be provided in the 2nd main surface 10b. According to such a configuration, the first main surface 10a in which glass powder or the like, which is likely to generate glass powder or the like during scribing, can be more reliably protected, and the second film forming unit 12b on the back surface that is difficult to cut during scribing is not formed. Since it is divided in advance by the portion 12c, it can be easily divided.

(Fourth modification)
FIG. 9 is a schematic cross-sectional view of a glass base material of a fourth modified example.

  In the above-described embodiment and the third modification, the example in which the first and second film forming portions 11b and 12b including the protective film pieces 11a and 12a are provided on both main surfaces of the glass base material 10 has been described. A protective film made of a protective film piece may be formed only on the surface. For example, as shown in FIG. 9, a glass plate 104 with a film according to a fourth modification of the present invention includes a constant thickness protective film 13 having a uniform thickness on the first main surface 10a to be scribed, The second main surface 10a includes a second film forming unit 12b composed of a plurality of protective film pieces 12a. If it is set as such a structure, when scribing from the 1st main surface 10a side, the 1st main surface 10a in which glass powder etc. which are easy to generate | occur | produce at the time of scribing can be protected more reliably. Further, the second film forming portion 12b on the back surface that is difficult to be cut at the time of scribing can be easily divided because it is partitioned in advance by the non-film forming portion 12c.

  Further, for example, when the necessity to protect the second main surface 10b in the manufacturing process of the glass article is low, the first film forming unit 11b is provided only on the first main surface 10a to be scribed, and the second It is good also as a structure which does not provide a protective film on the main surface 10b.

DESCRIPTION OF SYMBOLS 1 Glass article 10 Glass base material 10a 1st main surface 10b 2nd main surface 11a, 12a, 21a, 31a, 41a Protective film piece 11b, 12b Film-forming part 11c, 12c Non-film-forming part 11d, 12d Protective film piece Rows 11e, 12e Protective film strips 11f, 12f Thin portion 13 Constant thickness protective film 100, 101, 102, 103, 104 Glass plate L with film Planned cutting line

Claims (10)

On at least one of the first and second main surfaces of the glass base material having the first and second main surfaces, a film forming portion comprising a plurality of removable protective film pieces and the protective film pieces Forming a non-film-forming portion that is not formed;
Dividing the glass base material provided with the protective film piece, and obtaining a glass article having the protective film piece;
A method for producing a glass article.   The said film-forming part is a manufacturing method of the glass article of Claim 1 comprised by the continuous pattern of these protective film pieces of predetermined shape. The plurality of protective film pieces constitutes a plurality of protective film piece rows having a plurality of protective film pieces arranged at intervals from each other along one direction,
The plurality of protective film strips are spaced apart from each other along the other direction,
The manufacturing method of the glass article of Claim 1 or 2 with which the position in the said one direction of the said protective film piece has mutually shifted | deviated in the protective film piece row | line | column adjacent to the said other direction. The plurality of protective film pieces constitutes a plurality of protective film piece rows having a plurality of protective film pieces spaced apart from each other along the other direction,
The plurality of protective film single lines are spaced apart from each other along the one direction,
The method of manufacturing a glass article according to claim 3, wherein the positions of the protective film pieces in the other direction are shifted from each other in the protective film piece rows adjacent in the one direction.   5. The cutting step includes dividing the glass base material provided with the protective film pieces along a straight cutting line that crosses the film forming part and the non-film forming part. The manufacturing method of the glass article as described in any one of these. The protective film piece is provided on both the first main surface and the second main surface,
The protective film piece provided on the second main surface is made smaller than the protective film piece provided on the first main surface,
The glass article according to any one of claims 1 to 5, wherein the glass base material is divided by applying tensile stress to the microcrack after forming the microcrack by scribing the first main surface. Manufacturing method.   The method for producing a glass article according to any one of claims 1 to 6, wherein each of the plurality of protective film pieces has a hexagonal shape, a circular shape, or an elliptical shape. A film forming portion comprising a plurality of removable protective film pieces on at least one of the first and second main faces of the glass base material having the first and second main faces, and the protective film pieces A step of providing a thin part thinner than the protective film piece in a region where the film is not formed so as to be removable again;
Dividing the glass base material provided with the protective film piece, and obtaining a glass article having the protective film piece;
A method for producing a glass article. A glass plate having a first main surface and a second main surface;
A non-film forming part provided on at least one of the first and second main surfaces, and formed of a plurality of detachable protective film pieces, and a non-film forming part in which the protective film pieces are not formed;
A glass plate with a film. A glass plate having a first main surface and a second main surface;
A film-forming unit that is provided on at least one of the first and second main surfaces and includes a plurality of re-peelable protective film pieces;
A glass plate with a film, which is provided in a region where the protective film piece is not formed so as to be re-detachable and has a thin part thinner than the protective film piece.