U.S. patent application number 16/345211 was filed with the patent office on 2019-09-26 for manufacturing method for glass film with resin tape, and manufacturing method for glass film.
This patent application is currently assigned to NITTO DENKO CORPORATION. The applicant listed for this patent is NIPPON ELECTRIC GLASS CO., LTD., NITTO DENKO CORPORATION. Invention is credited to Yoshinori HASEGAWA, Kazuhito HOSOKAWA, Naohiro IKAI, Junichi INAGAKI, Toshihiro KANNO, Yohei KIRIHATA, Kaoru MITSUGI, Hiroki MORI, Takeshi MURASHIGE, Kota NAKAI.
Application Number | 20190292086 16/345211 |
Document ID | / |
Family ID | 62023428 |
Filed Date | 2019-09-26 |
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United States Patent
Application |
20190292086 |
Kind Code |
A1 |
MURASHIGE; Takeshi ; et
al. |
September 26, 2019 |
MANUFACTURING METHOD FOR GLASS FILM WITH RESIN TAPE, AND
MANUFACTURING METHOD FOR GLASS FILM
Abstract
Provided is a method comprises: continuously forming an
elongated, glass film having marginal portions from molten glass
into a given shape having two marginal portions, in
width-directional opposite edge regions thereof, wherein the glass
film having marginal portions has the marginal portions, and an
effective portion formed in a width-directional central region of
the glass film having marginal portions; annealing the glass film
having marginal portions; continuously forming resin tapes on the
glass film having marginal portions at positions adjacent to and
away by a given distance from the respective marginal portions, to
extend in a length direction of the glass film having marginal
portions; and continuously removing each of the marginal portions
from the glass film having marginal portions, along a position
between the marginal portion and a corresponding one of the resin
tapes, or at a given width-directional position within the
corresponding resin tape.
Inventors: |
MURASHIGE; Takeshi;
(Ibaraki-shi, Osaka, JP) ; INAGAKI; Junichi;
(Ibaraki-shi, Osaka, JP) ; HOSOKAWA; Kazuhito;
(Ibaraki-shi, Osaka, JP) ; NAKAI; Kota;
(Ibaraki-shi, Osaka, JP) ; KANNO; Toshihiro;
(Ibaraki-shi, Osaka, JP) ; HASEGAWA; Yoshinori;
(Otsu-shi, Shiga, JP) ; MITSUGI; Kaoru; (Otsu-shi,
Shiga, JP) ; IKAI; Naohiro; (Otsu-shi, Shiga, JP)
; MORI; Hiroki; (Otsu-shi, Shiga, JP) ; KIRIHATA;
Yohei; (Otsu-shi, Shiga, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NITTO DENKO CORPORATION
NIPPON ELECTRIC GLASS CO., LTD. |
Ibaraki-shi, Osaka
Otsu-shi, Shiga |
|
JP
JP |
|
|
Assignee: |
NITTO DENKO CORPORATION
Ibaraki-shi, Osaka
JP
NIPPON ELECTRIC GLASS CO., LTD.
Otsu-shi, Shiga
JP
|
Family ID: |
62023428 |
Appl. No.: |
16/345211 |
Filed: |
October 17, 2017 |
PCT Filed: |
October 17, 2017 |
PCT NO: |
PCT/JP2017/037547 |
371 Date: |
April 25, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 2701/17 20130101;
C03C 2218/355 20130101; B32B 17/10018 20130101; B32B 2329/00
20130101; C03B 17/064 20130101; C03B 33/091 20130101; B32B 2367/00
20130101; B65H 39/16 20130101; B65D 57/00 20130101; C03B 33/0235
20130101; B29C 65/48 20130101; B32B 17/064 20130101; B65D 85/672
20130101; C03B 17/06 20130101; B32B 2369/00 20130101; B32B 17/10
20130101; C03B 25/04 20130101; C03B 17/067 20130101; C03C 17/32
20130101; B32B 17/10366 20130101; C03B 33/02 20130101 |
International
Class: |
C03B 17/06 20060101
C03B017/06; B32B 17/10 20060101 B32B017/10; C03B 25/04 20060101
C03B025/04; C03C 17/32 20060101 C03C017/32; C03B 33/02 20060101
C03B033/02; B65H 39/16 20060101 B65H039/16 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 26, 2016 |
JP |
2016-209753 |
Claims
1. A manufacturing method of glass film with resin tape comprising:
a forming step of continuously forming an elongated glass film
having marginal portions having marginal portions in
width-directional opposite edge regions thereof from molten glass,
wherein the glass film having marginal portions has the marginal
portions, and an effective portion formed in a width-directional
central region of the glass film having marginal portions; an
annealing step of annealing the glass film having marginal
portions; a resin tape forming step of continuously forming resin
tapes on the glass film having marginal portions at positions
adjacent to and away by a given distance from the respective
marginal portions, in a length direction of the glass film having
marginal portions; and a marginal portion removal step of
continuously removing each of the marginal portions from the glass
film having marginal portions, at a position between the marginal
portion and a corresponding one of the resin tapes, or at a given
width-directional position within the resin tape, to form a glass
film with resin tape.
2. The manufacturing method of glass film with resin tape as
recited in claim 1, wherein the resin tape forming step comprises a
resin tape attaching step of attaching the resin tape to a surface
of the glass film having marginal portions, while continuously
feeding the resin tape from a resin tape roll.
3. The manufacturing method of glass film with resin tape as
recited in claim 2, wherein the resin tape attaching step includes
applying an adhesive to an interface between the resin tape and the
glass film having marginal portions.
4. The manufacturing method of glass film with resin tape as
recited in claim 1, wherein the resin tape forming step comprises a
resin solution application step of continuously applying a resin
solution to a surface of the glass film having marginal portions,
in a tape-like configuration.
5. The manufacturing method of glass film with resin tape as
recited in claim 4, wherein the resin solution is a solution of a
thermo-curable resin or a photo-curable resin.
6. The manufacturing method of glass film with resin tape as
recited in claim 1, wherein the resin tape forming step includes
forming the resin tapes at positions away from edge sides of the
glass film having marginal portions by 40% or less of a width of
the glass film having marginal portions.
7. The manufacturing method of glass film with resin tape as
recited in claim 1, wherein the forming step includes using one of
a float process, an overflow downdraw process, and a slot downdraw
process.
8. The manufacturing method of glass film with resin tape as
recited in claim 1, wherein the effective portion has a thickness
of 20 to 500 .mu.m.
9. The manufacturing method of glass film with resin tape as
recited in claim 1, which comprises a winding step of winding the
glass film with resin tape in the form of a roll.
10. The manufacturing method of glass film with resin tape as
recited in claim 9, wherein the resin tape forming step includes
continuously forming the resin tapes on only one surface of the
glass film having marginal portions, and the winding step includes
winding the glass film with resin tape in the form of a roll, in a
posture where the one surface of the glass film with resin tape
faces outwardly.
11. The manufacturing method of glass film with resin tape as
recited in claim 10, wherein the winding step includes continuously
feeding a protective sheet from a protective sheet roll, and
winding the glass film with resin tape in the form of a roll,
together with the protective sheet.
12. A glass film manufacturing method comprising: a step of
obtaining a glass film with resin tape using the manufacturing
method of glass film with resin tape as recited in claim 1; and a
resin tape removal step of continuously removing, from the glass
film with resin tape, width-directional opposite edge regions of
the glass film with resin tape on which the resin tapes are formed,
thereby forming a glass film.
13. The glass film manufacturing method as recited in claim 12,
which comprises a winding step of winding the glass film in the
form of a roll.
14. The glass film manufacturing method as recited in claim 12,
which comprises a step of cutting the glass film in a width
direction thereof.
Description
TECHNICAL FIELD
[0001] The present invention relates to a manufacturing method of
glass film with resin tape, and a glass film manufacturing method
using the same. In particular, the present invention relates to a
manufacturing method of glass film with resin tape capable of
stably manufacturing a glass film with resin tape, i.e., an
intermediate product of a glass film, while preventing crack
development due to wrinkles and reducing the load of a marginal
portion removal step, and a glass film manufacturing method using
the same.
BACKGROUND ART
[0002] Recent years, in the fields of display or illumination
elements using a liquid crystal display element or an organic EL
element, and of solar batteries, weight reduction and thickness
reduction have been promoted from the viewpoint of
transportability, storability, and designability, and development
toward continuous production by a roll-to-roll process has also
been promoted.
[0003] In such circumstance, as a way to give flexibility to glass
to be used in the above elements, it is proposed to use an
ultrathin (e.g., 200 .mu.m or less-thick) glass (hereinafter also
referred to as "glass film"). A glass film has flexibility, so that
it is capable of being wound in the form of a roll, and thus
processed through the roll-to-roll process. Heretofore, there have
been disclosures about a method of subjecting a glass film to
processing to form a polarizer, a transparent electrode or the like
thereon through the roll-to-roll process, and others.
[0004] For example, U.S. Pat. No. 8,525,405B discloses a method of
producing a display having a flexible glass layer, through the
roll-to-roll process.
[0005] Generally, sheet glasses including a glass film are produced
by forming molten glass into a flat and smooth sheet shape, and
annealing (slowly cooling) or cooling the resulting shaped body. As
a technique to form molten glass into a sheet shape, there has been
known: a float process which comprises forming molten glass floated
on liquid tin, into a sheet shape, by gradually drawing the molten
glass in a horizontal direction; a slot downdraw process which
comprises forming molten glass into a sheet shape by gradually
drawing the molten glass from a sheet-shaped opening (slot) in a
vertical direction; an overflow downdraw process which comprises
causing molten glass to overflow from a forming trough and then
guiding the overflowed glass downwardly, and others.
[0006] Although these process are different from each other in
terms of a specific means for forming molten glass into a sheet
shape, they resemble each other in terms of taking a technique for
mechanically holding lateral opposite edge regions of glass so as
to enable the glass to be formed into a sheet shape (including a
thin sheet shape). As a result, relatively thick marginal portions
are formed in the respective edge regions of the glass, so that a
difference in thickness arises between each of the edge regions and
an inward region of the glass. The presence of the thick marginal
portions in the edge regions causes difficulty in winding operation
for the resulting glass film. Thus, it is common practice to
produce a glass roll by winding the glass film after going through
a step of cutting and removing the thick marginal portions along a
longitudinal direction of the glass film by a laser, as described
in JP 2010-132531A.
[0007] On the other hand, due to the difference in thickness
between each of the thick edge regions (marginal portions) and the
inward region, arising during formation of the glass film, a
difference in cooling rate arises between each of the edge regions
and the inward region, i.e., the sheet glass is cooled in a state
in which there is a temperature difference between each of the edge
regions and the inward region. That is, the difference in cooling
rate leads to a difference in thermal shrinkage between each of the
edge regions and the inward region, and the difference in thermal
contraction leads to a difference in area within the sheet glass.
This difference in area is not particularly problematic in a sheet
glass having a thickness of around 700 .mu.m. On the other hand, in
a ultrathin glass sheet (glass film) having a thickness of 200
.mu.m or less, the difference in area is observed as wrinkles in
the inward region, because the glass film has flexibility. In this
glass film having marginal portions with wrinkles, the state of the
wrinkles is always changed during conveyance, and the state of
stress which arises at a cut site is also changed depending on the
change in the state of the wrinkles. This causes difficulty in
performing a slitting step of continuously cutting and removing the
marginal portions by a laser or the like.
[0008] With a view to solving this problem, JP 2015-140280A
describes a technique of cutting and removing the marginal portions
by a laser after smoothing out the wrinkles arising in the glass
film. According to this document, it is described that, by
performing the laser cutting after smoothing out the wrinkles, it
becomes possible to stably remove the marginal portions.
[0009] However, even when the above technique is employed in the
continuous cutting of the marginal portions (slitting step), it is
unable to continuously remove the marginal portions in a stable
manner, because it is difficult to completely remove the wrinkles,
in principle. Further, during the continuous cutting of the
marginal portions, a crack is likely to develop toward the inward
region of the glass film due to the wrinkles, thereby causing a
halt to the continuous cutting of the marginal portions. However,
the above technique is incapable to stopping development itself of
a crack.
CITATION LIST
Parent Document
[0010] Patent Document 1: U.S. Pat. No. 8,525,405B
[0011] Patent Document 2: JP 2010-132531A
[0012] Patent Document 3: JP 2015-140280A
SUMMARY OF INVENTION
Technical Problem
[0013] In view of solving the above problems, it is an object of
the present invention to provide a manufacturing method of glass
film with resin tape capable of stably manufacturing a glass film
with resin tape, i.e., an intermediate product of a glass film,
while preventing crack development due to wrinkles and reducing the
load of a continuous marginal portion removal step, and a glass
film manufacturing method using the same.
Solution to Technical Problem
[0014] As a result of diligent researches for solving the above
problems, the inventers found that crack development due to
wrinkles can be prevented to solve the above problem by, when
continuously removing an unnecessary part (marginal portions) from
an elongated, glass film having marginal portions, forming resin
tapes on the glass film having marginal portions at given positions
adjacent to respective width-directional opposite edge regions of
the glass film having marginal portions, and then performing the
continuous removal of the edge regions (marginal portions), and
have finally reached the present invention.
[0015] The present invention made to solve the above problems
relates to a manufacturing method of glass film with resin tape
comprising: a forming step of continuously forming an elongated
glass film having marginal portions having marginal portions in
width-directional opposite edge regions thereof from molten glass,
wherein the glass film having marginal portions has the marginal
portions, and an effective portion formed in a width-directional
central region of the glass film having marginal portions; an
annealing step of annealing the glass film having marginal
portions; a resin tape forming step of continuously forming resin
tapes on the glass film having marginal portions at positions
adjacent to and away by a given distance from the respective
marginal portions, in a length direction of the glass film having
marginal portions; and a marginal portion removal step of
continuously removing each of the marginal portions from the glass
film having marginal portions, at a position between the marginal
portion and a corresponding one of the resin tapes, or at a given
width-directional position within the resin tape, to form a glass
film with resin tape.
[0016] Preferably, in the manufacturing method of glass film with
resin tape of the present invention, the resin tape forming step
comprises a resin tape attaching step of attaching the resin tape
to a surface of the glass film having marginal portions, while
continuously feeding the resin tape from a resin tape roll.
[0017] More preferably, in the above manufacturing method of glass
film with resin tape, the resin tape attaching step includes
applying an adhesive to an interface between the resin tape and the
glass film having marginal portions.
[0018] It should be noted here that the term "adhesive" includes a
so-called "pressure-sensitive adhesive".
[0019] As an alternative, in the manufacturing method of glass film
with resin tape of the present invention, the resin tape forming
step may comprise a resin solution application step of continuously
applying a resin solution to a surface of the glass film having
marginal portions, in a tape-like configuration.
[0020] More preferably, in the above manufacturing method of glass
film with resin tape, the resin solution is a solution of a
thermo-curable resin or a photo-curable resin.
[0021] Preferably, in the manufacturing method of glass film with
resin tape of the present invention, the resin tape forming step
includes forming the resin tapes at positions away from edge sides
of the glass film having marginal portions by 40% or less of a
width of the glass film having marginal portions.
[0022] Preferably, in the manufacturing method of glass film with
resin tape of the present invention, the forming step includes
using one selected from the group consisting of a float process, an
overflow downdraw process, and a slot downdraw process.
[0023] Preferably, in the manufacturing method of glass film with
resin tape of the present invention, the effective portion has a
thickness of 20 to 500 .mu.m.
[0024] Preferably, the manufacturing method of glass film with
resin tape of the present invention comprises a winding step of
winding the glass film with resin tape in the form of a roll.
[0025] More preferably, in the above manufacturing method of glass
film with resin tape,
[0026] the resin tape forming step includes continuously forming
the resin tapes on only one surface of the glass film having
marginal portions, and the winding step includes winding the glass
film having marginal portions in the form of a roll, in a posture
where the one surface of the glass film with resin tape faces
outwardly.
[0027] More preferably, in the above manufacturing method of glass
film with resin tape, the winding step includes continuously
feeding a protective sheet from a protective sheet roll, and
winding the glass film with resin tape in the form of a roll,
together with the protective sheet.
[0028] The present invention preferably comprises: a step of
obtaining a glass film with resin tape using the above
manufacturing method of glass film with resin tape; and a resin
tape removal step of continuously removing, from the glass film
with resin tape, width-directional opposite edge regions of the
glass film with resin tape on which the resin tapes are formed,
thereby forming a glass film.
[0029] Preferably, the glass film manufacturing method of the
present invention comprises a winding step of winding the glass
film in the form of a roll.
[0030] Preferably, the glass film manufacturing method of the
present invention comprises a step of cutting the glass film in a
width direction thereof.
Effect of Invention
[0031] The manufacturing method of glass film with resin tape and
the glass film manufacturing method of the present invention make
it possible to stably manufacture a glass film with resin tape
(typically, a resin tape-attached glass roll), i.e., an
intermediate product of a glass film, and a glass film (typically,
a glass roll or a sheet-shaped glass film), while preventing crack
development due to wrinkles and reducing the load of the continuous
marginal portion removal step.
BRIEF DESCRIPTION OF DRAWINGS
[0032] FIG. 1 is a process flow chart of a manufacturing method of
glass film with resin tape according to the present invention.
[0033] FIG. 2 is a schematic diagram for explaining one example of
the overall process of the manufacturing method of glass film with
resin tape according to the present invention.
[0034] FIG. 3(a) is a schematic diagram for explaining the details
of one example of a forming step in the manufacturing method of
glass film with resin tape according to the present invention, and
FIG. 3(b) is a sectional view taken along the line A-A in FIG.
3(a).
[0035] FIGS. 4(a) to 4(c) are schematic diagrams for explaining
respective steps of the manufacturing method of glass film with
resin tape according to the present invention.
[0036] FIG. 5 is a schematic diagram for explaining the details of
one example of a glass film winding step in the manufacturing
method of glass film with resin tape according to the present
invention.
[0037] FIG. 6 is a schematic diagram for explaining one example of
a glass film manufacturing method according to the present
invention.
DESCRIPTION OF EMBODIMENTS
[0038] FIG. 1 is a process flow chart of a manufacturing method of
glass film with resin tape according to the present invention. As
depicted in FIG. 1, the manufacturing method of glass film with
resin tape according to the present invention comprises a forming
step (P1), an annealing step (P2), a resin tape forming step (P3),
and a marginal portion removal step (P4), and may further comprises
a winding step (P5). Specific examples of these steps will be
described in detail below.
[0039] FIG. 2 is a schematic diagram for explaining one example of
the overall process of a manufacturing method for a glass film with
resin tape Ga, according to the present invention. FIGS. 3(a) and
3(b) are schematic diagrams for explaining the details of one
example of a forming step in the manufacturing method for the glass
film with resin tape Ga, according to the present invention.
<Forming Step (P1)>
[0040] The forming step (P1) is a step of continuously forming an
elongated, glass film having marginal portions Gc from molten glass
into a given shape having two marginal portions Gb, respectively,
in width-directional opposite edge regions thereof.
[0041] According classification by composition, examples of a raw
material for the molten glass include soda-lime glass, borosilicate
glass, aluminosilicate glass, and quartz glass. Further, according
classification by alkaline component, examples thereof include
alkali-free glass, and low-alkali glass. Preferably, alkali-free
glass is used. This is because alkali-free glass is excellent in
strength and chemical durability. The molten glass is used in a
molten state after heating at an arbitrary appropriate temperature
(1400.degree. C. to 1700.degree. C.).
[0042] Examples of a technique to continuously form the molten
glass into a film shape include an overflow downdraw process, a
slot downdraw process, and a float process. Even by employing any
one of the above processes, it is possible to continuously form the
elongated, glass film having marginal portions Gc into a given
shape having the marginal portions Gb in the respective
width-directional opposite edge regions thereof. It is to be
understood that the present invention is not limited to the above
forming processes as long as the marginal portions Gb are formed in
the respective width-directional opposite edge regions of the glass
film having marginal portions Gc.
[0043] In particular, the overflow downdraw process is preferable
as a technique to continuously form a thinned glass film. A glass
film obtainable through this process has a feature that each
surface thereof has excellent smoothness, i.e., this process is
less likely to cause in-plane defects, and suitable for
continuously forming a glass film.
[0044] With reference to FIGS. 2 and 3, a specific example of the
forming step using the overflow downdraw process will be
described.
[0045] As depicted in FIG. 2, a forming apparatus 10 has a forming
region 10A in which a forming body 11 having a wedge-shaped outer
surface in vertical section is disposed. When glass melted in a
non-depicted melting kiln (molten glass) is supplied into the
forming body 11, the molten glass overflows from a top opening of
the forming body 11. Then, forming of the molten glass into a glass
film ribbon Gd is started such that the overflowed molten glass
flows downwardly along opposite lateral surfaces of the forming
body 11 having a wedge shape in vertical section, and merges at a
lower end of the forming body 11. After merging at the lower end,
width-directional opposite edge regions of the glass film ribbon Gd
are held, respectively, by two cooling roller pairs 12, so that two
thick marginal portions Gb (see FIG. 3(b)) are formed,
respectively, in the width-directional opposite edge regions of the
glass film ribbon Gd. By forming the marginal portions Gb, it is
possible to suppress aggregation due to surface tension and thermal
shrinkage, and promote thinning and curing while maintaining the
form of a film. This makes it possible to form a glass film having
marginal portions Gc into a given shape. Although metal roller
pairs are typically used as the cooling roller pairs 12, the
present invention is not limited thereto.
(P2) Annealing Step
[0046] The annealing step (P2) is a step of annealing the glass
film having marginal portions Gc.
[0047] As depicted in FIGS. 2 and 3, a plurality of sets of two
annealer roller pairs 13 and a non-depicted heater are arranged in
an annealing region 10B. The annealing region 10B is set such that
a given temperature gradient is formed by the non-depicted heater,
so that, as the glass film having marginal portions Gc flows
downwardly along the annealing region 10B, the temperature thereof
is gradually lowered and thus thermal strain generated thereinside
is removed. In this example, the annealer roller pairs 13 in the
annealing region 10B are made of an inorganic material comprising
ceramic fibers and a binder. However, the present invention is not
limited thereto. Further, all the annealer roller pairs 13 need not
hold the glass film having marginal portions Gc, but part of the
annealer roller pairs 13 may be an idle roller pair.
[0048] As depicted in FIGS. 3(a) and 3(b), in the glass film having
marginal portions Gc, each of the edge regions which are being held
is maintained thick (as the marginal portion Gb), whereas an inward
thinned region (thinned portion Ge) is stretched in a flow
direction, in principle. As a result, a difference in size (area
difference) between the marginal portion Gb and the thinned portion
Ge occurs. This is assumed to cause generation of wrinkles Gf in
the thinned portion Ge. However, if the marginal portions Gb are
removed, the wrinkles Gf in the thinned portion Ge are relieved,
and thus it becomes possible to form a glass film with resin tape
or glass film and continuously wind it.
(P3) Resin Tape Forming Step
[0049] The resin tape forming step is roughly classified into the
following two processes. Specifically, (1) process of attaching at
least two tape-shaped resin films onto a surface of the glass film
having marginal portions, while continuously feeding the
tape-shaped resin films (resin tape attaching step), and (ii)
continuously applying resin in solution form to a surface of the
glass film, and curing the resin to form at least two tape-shaped
resin films on the surface (resin solution application step).
(i) Process of Laminating Tape-Shaped Resin Films (Resin Tapes) to
Glass Film Having Marginal Portions (Resin Tape Attaching Step)
[0050] Examples of a laminating method includes a technique of
laminating tape-shaped resin films (resin tapes), while forming
resin films into a tape shape, and a technique of laminating resin
films each preliminarily formed into a tape shape. As a technique
to develop adhesiveness between each of the tape-shaped resin films
and the glass film having marginal portions, an adhesive or
pressure-sensitive adhesive is preferably interposed between the
resin tape and the glass film having marginal portions.
Alternatively, each of the resin tapes may be thermally fused
before or after lamination of the resin tape to develop
adhesiveness with respect to the glass, based on an anchor
effect.
[0051] In a particularly preferred embodiment, the lamination is
performed while the resin tapes each wound into a roll are
continuously unrolled and fed, and an adhesive or
pressure-sensitive adhesive is interposed between each of the resin
tape and the glass.
[0052] The resin tapes are arranged and laminated at positions
adjacent to and away by a given distance from the respective
marginal portions of the glass film having marginal portions.
[0053] Examples of a material for the resin tapes include
polyethylene, polyvinyl chloride, polyethylene terephthalate,
polyvinylidene chloride, polypropylene, polyvinyl alcohol,
polyester, polycarbonate, polystyrene, polyacrylonitrile, an
ethylene vinyl acetate copolymer, an ethylene-vinyl alcohol
copolymer, an ethylene-methacrylic acid copolymer, nylon,
cellophane, and a silicone resin. The resin tape may be formed as a
mixture or a laminate thereof. From an industrial viewpoint,
polyethylene terephthalate resin is preferable.
[0054] As a production method for resin tapes made of the above
materials, it is possible to use an inflation process, a T-die
process, a melt casting process, a calender process, etc. From an
industrial viewpoint, it is preferable to produce a resin tape roll
by, after forming a wide-width resin film through one of the above
processes, slitting the wide-width resin film into a given width,
and winding the resulting tape-shaped resin film.
[0055] The resin film laminated through an adhesive or
pressure-sensitive adhesive are preferably subjected to
cross-linking reaction, and stabilized, using a device for
radiating ultraviolet light or electron beam. In this way, the
glass film having marginal portions and the resin tapes are
strongly fixed together, so that it can be expected to enhance the
effect of suppressing crack development in the glass.
[0056] A technique to interpose an adhesive or pressure-sensitive
adhesive between each of the resin tapes and the glass film having
marginal portions may comprise: dropping or continuously applying
liquid adhesive or pressure-sensitive adhesive to one or each of
the resin tape and the glass film having marginal portions; or
laminating a sheet-shaped adhesive film or pressure-sensitive
adhesive film to the resin tape or the glass film having marginal
portions successively to or currently with the lamination of the
resin tape. Alternatively, a roll formed by winding a laminate of a
resin tape preliminarily applied with an adhesive or
pressure-sensitive adhesive and a release film (separator) attached
onto the adhesive or pressure-sensitive adhesive may be used.
[0057] FIGS. 4(a) to 4(c) are schematic diagrams for explaining
respective steps of the manufacturing method of glass film with
resin tape according to the present invention. Specifically, FIG.
4(a), FIG. 4(b) and FIG. 4(c) are, respectively, a sectional view
taken along the line B-B in FIG. 2, a sectional view taken along
the line C-C in FIG. 2, and a sectional view taken along the line
D-D in FIG. 2.
[0058] With reference to FIG. 2 and FIGS. 4(a) to 4(c), a
particularly preferred embodiment will be described. Each of two
resin tapes 21 is continuously fed from a resin tape roll 20. Then,
after applying an adhesive (not depicted) to each of the resin
tapes 21, the resin tapes 21 are laminated to the glass film having
marginal portions Gc at positions adjacent to and away by a given
distance from the respective marginal portions Gb, and irradiated
with ultraviolet light from an ultraviolet light irradiation device
22 to continuously form the resin tapes 21 in a length direction of
the glass film having marginal portions Gc.
[0059] As depicted in FIG. 4(b), the glass film having marginal
portions Gc normally has the thick marginal portions Gb, and an
effective portion Gg formed in a width-directional central region
of the glass film having marginal portions Gc. Here, the effective
portion Gg is a portion of the glass film having marginal portions
Gc formed between the resin tapes 21. The effective portion Gg
includes a region which is guaranteed in terms of a desired
thickness and is capable of shipment as a product. Considering that
the effective portion Gg includes a region to be used as a product,
the thickness of the effective portion Gg is preferably 20 .mu.m to
500 .mu.m, more preferably 20 .mu.m to 300 .mu.m, still more
preferably 20 .mu.m to 150 .mu.m, from the viewpoint of handling
and flexibility.
[0060] On the other hand, a non-effective portion Gh is resin tapes
21 and a portion of the glass film having marginal portions Gc
outside each of the resin tapes 21. Specifically, the non-effective
portion Gh include the marginal portions Gb and a portion whose
thickness gradually decreases from the marginal portions Gb toward
the effective portion Gg, i.e., includes a region which is not
guarantee in terms of a desired thickness as a product, and is
incapable of shipment as a product. In a case where it is necessary
to set the width of the effective portion Gg to a relatively small,
a region guaranteed as a product may be partially included in the
non-effective portion Gh.
[0061] In this embodiment, the given distance means a distance h1
between one of opposite edges 21a of each of the resin tapes 21 on
the side of a corresponding one of the marginal portions Gb, and an
edge Gb 1 of the corresponding marginal portion Gb on the side of
the resin tape 21, as depicted in FIG. 4(b). In this embodiment,
from the view point of widely ensuring the effective portion Gg, a
distance h2 between the edge side Gc1 of the glass film having
marginal portions Gc and the edge 21a of the resin tapes 21 is
preferably 40% or less, more preferably 30% or less, still more
preferably 20% or less, particularly preferably 10% or less, of the
width w1 of the glass film having marginal portions Gc.
[0062] Further, from the viewpoint of effectively preventing crack
development, in a case where, in the marginal portion removal step
(P4) descried in detail later, each of the marginal portions Gb is
continuously removed along a given width-directional position
between the marginal portion Gb and a corresponding one of the
resin tapes 21, the width w2 of each of the resin tapes 21 is
preferably 3 mm or more, more preferably 10 mm or more. On the
other hand, in a case where, in the marginal portion removal step
(P4) descried in detail later, each of the marginal portions Gb is
continuously removed at a given width-directional position within
the corresponding resin tape, the width w2 of each of the resin
tapes 21 is selected such that the width of a part of the resin
tape to be left on the glass film with resin tape Ga preferably
becomes 3 mm or more, more preferably 10 mm or more. Further, from
the viewpoint of ensuring the width of the effective portion Gg,
the width w2 is preferably 100 mm or less, more preferably 50 mm or
less.
[0063] Further, from the viewpoint of effectively preventing crack
development, the thickness t1 of each of the resin tapes 21 is
preferably 25 .mu.m to 500 .mu.m, more preferably 50 .mu.m to 200
.mu.m. It should be noted here that, in case of using a
non-depicted adhesive layer, the thickness t1 of each of the resin
tapes 21 is a thickness as measured after removing the adhesive
layer.
[0064] In a case where the adhesive is liquid form, when the resin
tapes are laminated to the glass film having marginal portions, the
adhesive has good wettability and spreading with respect to the
glass, so that air bubbles or the like are less likely to be
entrained between the glass and each of the resin tapes. Further,
before the adhesive is cured, there is a chance for each of the
adhesive tapes to freely slide on the surface of the glass. Thus,
slight wrinkles and meandering irregularly occurring during the
lamination are advantageously self-corrected before curing of the
adhesive.
[0065] Examples of the adhesive include an epoxy-based adhesive, an
acrylic-based adhesive, a urethane-based adhesive, a rubber-based
pressure-sensitive adhesive, an acrylic-based pressure-sensitive
adhesive, a silicone-based pressure-sensitive adhesive and a
urethane-based pressure-sensitive adhesive, and any mixture
thereof. From the viewpoint of effectively preventing crack
development, the thickness of the adhesive layer is preferably 1
.mu.m to 10 .mu.m, more preferably 1 .mu.m to 40 .mu.m.
(ii) Process of Continuously Applying Resin in Solution Form to
Surface of Glass Film (Resin Solution Application Step)
[0066] As a resin material, it is possible to use a
solvent-dissolvable resin, or a thermo- or photo-curable resin.
[0067] As the solvent-dissolvable resin, it is possible to use
polyimide, polyamide, polyarylate, polyethylene, polyvinyl
chloride, polyethylene terephthalate, polyvinylidene chloride,
polypropylene, polyvinyl alcohol, polyester, polycarbonate,
polystyrene, polyacrylonitrile, polyvinyl alcohol,
triacetylcellulose, an ethylene vinyl acetate copolymer, an
ethylene-vinyl alcohol copolymer, an ethylene-methacrylic acid
copolymer, nylon, cellophane, or silicone resin, or any mixture
thereof.
[0068] Examples of the thermo- or photo-curable resin include an
epoxy-based resin, an acrylic-based adhesive, a urethane-based
adhesive, and a rubber-based resin, and any mixture thereof.
[0069] In a preferred embodiment, the solution-form
solvent-dissolvable resin or the thermo- or photo-curable resin is
continuously applied onto the surface of the glass film at
positions adjacent to and away by a given distance from the
respective marginal portions, and irradiated with heat, light or
electron beam to continuously form two resin tapes in the length
direction of the glass film.
[0070] In this preferred embodiment, the width and position of each
of the resin tapes are the same as those in the above resin tape
attaching step.
(P4) Marginal Portion Removal Step
[0071] The marginal portion removal step (P4) is process of
continuously removing each of the marginal portions Gb from the
glass film having marginal portions Gc, along a position between
the marginal portion Gb and a corresponding one of the resin tapes
21, or at a given width-directional position within the
corresponding resin tape 21, to form a glass film with resin tape
Ga.
[0072] As a technique to remove the marginal portions Gb, it is
possible to use a technique of mechanically cutting the glass, a
technique of flawing (scribing) the surface of the glass, and
glowing a crack (breaking the glass) by heat or bending stress, or
a technique of volatilizing the glass or fragmenting the chemical
bonding of the glass by light. Referring FIG. 2 again, as a
technique to continuously remove the marginal portions Gb, it is
preferable to use, as an energy source, light, particularly a laser
light source 30 capable of radiating laser light as collimated and
coherent light. It is preferable to select laser light having a
wavelength bend in which light absorption by a glass is
significant. Further, for increasing irradiation energy, it is
effective to focus the laser light inside the glass by using an
optical system such as lenses. As the laser light source 30, it is
possible to use a CO.sub.2 laser, a YAG laser or the like. As
depicted in FIG. 4(c), in order to adequately perform the marginal
portion removal step P4, a distance h3 from the one edge of the
resin tape 21a of the resin tape 21 to a cut line by the laser
light source 30 is preferably set to 1 mm or more, more preferably
3 mm or more. In this manner, each of the marginal portions Gb can
be continuously removed from the glass film having marginal
portions Gc, along a given position between the marginal portion Gb
of the glass film having marginal portions Gc and a corresponding
one of the resin tapes 21, as depicted in FIG. 4(c) (or within the
corresponding resin tape 21), to produce a glass film with resin
tape Ga. As a result of cutting and removal of the marginal
portions Gb, the wrinkles Gf generated in the glass film having
marginal portions Gc are relieved. Here, from the viewpoint of more
simply performing the continuous removal of the marginal portions,
it is preferable to continuously remove each of the marginal
portions Gb from the glass film having marginal portions Gc, along
a given width-directional position between the marginal portion Gb
and a corresponding one of the resin tapes 21, as depicted in FIG.
4(c).
[0073] The manufacturing method of glass film with resin tape
according to the present invention may further comprise the winding
step (P5) to produce a roll of the glass film with resin tape Ga
(hereinafter referred to as "resin tape-attached glass roll
Gi").
(P5) Winding Step
[0074] The winding step (P5) depicted in FIG. 1 is process of
winding the glass film with resin tape Ga in the form of a roll to
produce a resin tape-attached glass roll Gi.
[0075] As depicted in FIG. 2 to FIG. 5, in a case where the resin
tapes 21 are formed on only one surface (upper surface Gj) of the
glass film with resin tape Ga, it is preferable to wind the glass
film with resin tape Ga around a winding core 40, in a posture
where the upper surface Gj of the glass film with resin tape Ga on
which the resin tapes 21 are formed, face outwardly.
[0076] Thus, even when a curvature arises in the glass film with
resin tape Ga during winding, it becomes possible to effectively
block growth of a crack starting from an edge of the glass film
with resin tape Ga in a tearing direction by a corresponding one of
the resin tapes 21.
[0077] Further, it is preferable to, during winding the glass film
with resin tape Ga, continuously feed a protective sheet 51 from a
protective sheet roll 50, and wind the glass film with resin tape
Ga in the form of a roll, together with the protective sheet 51.
This makes it possible to protect the surface of the glass film,
and prevent winding displacement from being fixed due to blocking
caused by smoothness of the surface of the glass film. Although the
protective sheet 51 is not particularly limited, but examples
thereof includes: a resin sheet such as polyethylene terephthalate,
polystyrene, polyethylene, polypropylene, polyimide, nylon,
polyvinyl chloride, polyester, polycarbonate, cellophane, or
silicone; a foamable resin sheet; and paper.
[0078] From the view point of continuing good winding without
winding displacement, it is preferable to dispose the protective
sheet 51 between the resin tapes 21. This makes it possible to
prevent interference between the protective sheet 51 and the resin
tapes 21. In this case, in order to prevent the resin tapes 21 on a
previously-wound part of the glass film with resin tape Ga from
coming into contact with a subsequently-wound part of the glass
film in the glass film with resin tape Ga, it is preferable that
the thickness of the protective sheet 51 is greater than the
thickness of each of the resin tapes 21 (when using the adhesive
layer, the total thickness of the resin tape as a substrate and the
adhesive layer). Thus, even when the thickness of the adhesive
layer becomes uneven when each of the resin tape 21 is bonded to
the glass film having marginal portions Gc, the resin tapes 21
never come into contact with the glass film, during production of
the resin tape-attached glass roll Gi. This makes it possible to
prevent the occurrence of winding displacement due to the
unevenness of the thickness of the adhesive layer, during
production of the resin tape-attached glass roll Gi.
[0079] On the other hand, from the viewpoint of protecting edge
faces of the resin tape-attached glass roll Gi after the winding,
it is preferable that the width of the protective sheet 51 is
greater than the width of the glass film with resin tape Ga.
[0080] FIG. 2 depicts a production system constructed by
selectively combining desirable examples of the above process
elements (P1 to P5). However, the present invention is not limited
thereto. Further, the schematic diagram depicts a process in which,
after the glass film having marginal portions Gc is formed into a
given shape and solidified through the overflow downdraw process,
while being conveyed in a vertical direction, and further conveyed
by feed roller pairs 60, the direction of the glass film having
marginal portions Gc is changed in a transverse direction by
direction-change rollers 70, and then the wounding step is
performed. However, the glass film having marginal portions Gc may
be conveyed only in the vertical direction by omitting the
direction-change rollers 70, or may be conveyed only in the
transverse direction in a case where the float process is employed.
The process elements P1 to P5 are not limited to those in FIG. 2,
as long they are an optimal arrangement in terms of productivity
under restrictions of principle.
[0081] In the resin tape forming step (P3) depicted in FIG. 2, the
resin tapes 21 are formed on only the upper surface Gj of the glass
film having marginal portions Gc. However, the present invention is
not limited thereto, but the resin tapes 21 may be formed on only a
lower surface or each of the upper and lower surfaces of the glass
film having marginal portions Gc.
[0082] FIG. 6 is a schematic diagram for explaining one example of
a glass film manufacturing method according to the present
invention.
[0083] For example, as depicted in FIG. 6, a glass film Gk
according to the present invention is produced by: unrolling the
glass film with resin tape Ga from the resin tape-attached glass
roll Gi; and performing a resin tape removal step of continuously
removing, from the glass film with resin tape Ga, width-directional
opposite edge regions G1 of the glass film with resin tape Ga on
which the resin tapes are formed, by cutting means such as a laser
light source 31. As depicted in FIG. 6, the glass film Gk may be
further wound into a roll of the glass film Gk (glass roll Gm), or
may be cut in a width direction by a non-depicted width-directional
cutting device, to produce a sheet-shaped glass film Gk. Further, a
feeding source is not limited to the resin tape-attached glass roll
Gi, but may be the sheet-shaped glass film with resin tape Ga in an
unrolled state. The glass film with resin tape Ga is free of
wrinkles Gf, as mentioned above. Thus, the width-directional
opposite edge regions G1 of the glass film with resin tape Ga can
be continuously removed adequately by the laser light source 31,
without further firming the resin tapes 21.
EXAMPLES
[0084] Although the manufacturing method of glass film with resin
tape according to the present invention will be described in detail
based on an example, it should be noted that the present invention
is not limited to such an example.
Inventive Example
[0085] A glass film with resin tape was produced using the method
described in connection with FIG. 2. Specifically, a glass film
having marginal portions was formed into a given shape through the
overflow downdraw process, to have a width of 1500 mm. The
thickness of each of two marginal portions was 1 mm, the thickness
of an effective portion was 100 .mu.m. After annealing the glass
film having marginal portions, the direction of the glass film
having marginal portions was changed to a transverse direction.
Each of two resin tapes made of polyethylene terephthalate (PET)
and formed to have a width of 25 mm was laminated to an upper of
the glass film having marginal portions after being subjected to
the direction change, while an ultraviolet-curing resin was
interposed therebetween at a thickness of 20 .mu.m. After the
lamination, the resin tapes were irradiated with ultraviolet light
to bond the resin tapes to the upper surface of the glass film
having marginal portions. Here, each of the resin tapes was
attached at a position where the h1 in FIG. 4(b) is 130 mm.
Subsequently, the marginal portions were continuously removed by
radiating a CO.sub.2 laser having a wavelength of 10.6 .mu.m from
the upper surface of the glass film having marginal portions. The
CO.sub.2 laser is radiated to a position where the h3 in FIG. 4(c)
is 5 mm. A glass film with resin tape obtained after the cutting
and removal was wound around a winding core through a protective
sheet to produce a resin tape-attached glass roll. As a result, a
glass film with resin tape having a length of 1 km could be wound
into a roll 10 times without breakage. That is, even when laser
cutting of the marginal portions was continuously performed over 10
km, no breakage occurred.
[0086] Further, the above resin tape-attached glass roll having a
length of 1 km was unrolled, and subjected to cutting using a
CO.sub.2 laser having a wavelength of 10.6 .mu.m to continuously
remove width-directional opposite edge regions of the glass film
with resin tape on which the resin tapes were formed, thereby
producing a glass film. The CO.sub.2 laser is radiated to a
position away inwardly from an edge of the glass film with resin
tape by 35 mm (5 mm inward from an outer edge of the resin tapes).
The produced glass film was further wound through a protective film
to form a glass roll. The above ten resin tape-attached glass rolls
were unrolled, and each of the resulting ten tape-attached glass
films was used to produce a glass roll. As a result, all of the ten
glass films could be wound without breakage.
Comparative Example
[0087] Except that no resin tape was used, a glass roll was
produced in the same manner as that in Inventive Example. As a
result, it was unable to produce a glass roll having a length of 1
km. Laser cutting of the marginal portions was tried over a
cumulative distance of 10 km. However, breakage occurred 53
times.
LIST OF REFERENCE SIGNS
[0088] 10: forming apparatus [0089] 21: resin tape [0090] 30: laser
light source [0091] 40: winding core [0092] 51: protective sheet
[0093] Ga: glass film with resin tape [0094] Gb: marginal portion
[0095] Gc: glass film having marginal portions [0096] Gf: wrinkle
[0097] Gg: effective portion [0098] Gh: non-effective portion
[0099] Gi: resin tape-attached glass roll [0100] Gj: upper surface
[0101] Gk: glass film [0102] Gl: width-directional opposite edge
region on which resin tapes are formed [0103] Gm: glass roll
* * * * *