JP2002226095A - Bonding tape, support bonding method and support coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an adhesive from protruding from an end of an adhesive tape. SOLUTION: A groove 41a having a diameter of about 50 μm and a depth of 15 μm and having a circular cross section is formed at a pitch of 100 μm on one side of a PET film 41. An acrylic adhesive 42 is applied to the groove forming surface to form an adhesive tape 43. Even if the two webs 60 and 61 are joined together with an adhesive tape 43 to make them longer and various kinds of coating are performed, the adhesive 4 is formed by the grooves 41a.
2 is retained and the adhesive does not protrude. In addition, the adhesion of foreign matter to the application surface due to the protrusion of the adhesive is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding tape for bonding a support, a method for bonding a support using the bonding tape, and a method for coating the bonded support.

[0002]

2. Description of the Related Art Adhesive tapes are made of plastic films,
It is used as a tape for joining paper or a thin metal foil, a laminated sheet thereof, or a strip-shaped flexible support (hereinafter, referred to as a web) made of these materials. As the adhesive tape, one obtained by directly applying an adhesive to a tape base or one obtained by applying an adhesive on both sides of very thin paper or the like and attaching the same to the tape base is used. Various types of paper, various types of plastic films, metal foils such as aluminum, or laminates thereof, and various types of metals and metal oxides on paper, plastic films, etc. are used for the tape base of the adhesive tape. Thinly coded ones are used.

[0003] In the production of conventional optical films, when applying a coating solution to a web, a web as long as possible is used in order to reduce the loss of the web. Therefore, a method has been adopted in which the webs are joined together to form a long web and are continuously applied at once. Web Joining
As shown in FIG. 7 (a), adhesive tapes 12 are applied from both the front and back surfaces of the webs so that the end faces of the webs 10 and 11 do not overlap. Further, the adhesive tape is stuck over the width direction of the web as shown in FIG. 7 (b). As another method, there is a method in which a plurality of adhesive tapes 13 are attached so as to intersect the end faces of the webs 10 and 11 as shown in FIG. Further, as shown in FIG. 9, there is a method in which ends of two webs 14 and 15 are overlapped and an adhesive tape 16 is attached.

Even if the web is bonded with an adhesive tape by any of the methods, there is a problem that uneven coating of the coating liquid, streaks, or coating abnormalities such as local thickening and thin coating are apt to occur at the bonded portion. . For this reason, when applying a web having a joint, a method for reducing the loss due to the abnormal application was required. For example, Japanese Patent Application Laid-Open No. 58-88074 discloses a method in which the application head is separated from the application position immediately before the joint is applied, and is returned to the original position after the joint passes. Further, in Japanese Patent No. 2,632,265, a black layer is provided at a joint portion, and the surface potential is 0.5 to
A method for charging to 2.0 kV is disclosed. According to these methods, it is possible to reduce various coating abnormalities due to a change in the wettability of the coating liquid at the web and the joint by the adhesive tape.

[0005]

However, even with the above method, there is a problem that the failure due to the protrusion of the adhesive from the adhesive tape cannot be reduced. FIG.
Is a coating apparatus using an extrusion coater method. The web 21 delivered from the delivery device 20 is:
The rollers are conveyed to the extrusion coater 24 by the rollers 22 and 23. Extrusion coater 24
Then, the web 21 supported by the backup roller 25
Is applied with a coating liquid. Next, the web 21
The paper 6 is sent through the dryer 27 and dried. The dried web 21 is conveyed by pass rollers 28 and 29 and wound up by a winder 30.

[0006] In the coating device, depending on the surface in contact with the web,
Two types of rollers are provided in combination. These are a roller in contact with the application surface of the web (hereinafter referred to as the application surface side roller 22) and a roller in contact with the surface on which the web is not applied (hereinafter referred to as the opposite surface side roller 23). Similarly, the pass rollers 28, 29 are also composed of the application surface side roller 28 and the opposite surface side roller 29.

[0007] When the web is conveyed by these rollers, the problem of adhesive bleeding occurs. When the adhesive tape is adhered to the application surface and the web 21 is joined, the adhesive tape joining the web 21 is squeezed by the application surface roller 22 and a phenomenon occurs that the adhesive protrudes from the end of the adhesive tape. . The small amount of adhesive that has overflowed contaminates the roller and transfers it to the subsequent web 21. This causes an abnormal application surface when the application liquid is applied to the web 21. Further, after the web 21 is sent out from the dryer 27, a similar problem occurs with the application surface side roller 28 of the pass roller, which causes a failure such as adhesion of foreign substances on the application surface later. This problem occurs even when the web 21 is bonded using the adhesive tape on the surface opposite to the application surface. That is, the adhesive tape is ironed by the opposite rollers 23 and 29 to stain the rollers,
Transfer to subsequent web. Further, when the web is wound up, the web is transferred to the coating surface side, causing a failure with foreign matters and the like. In the coating apparatus, the coating side rollers 22 and 28 and the opposite side rollers 23 and 29 are combined, so that the problem of the protrusion of the adhesive is an unavoidable problem when the web is bonded by the adhesive tape. .

An object of the present invention is to provide a bonding tape which prevents the adhesive from protruding from the end of the tape.

Another object of the present invention is to provide a method for joining webs by using the joining tape. Still another object is to provide a method for applying a coating liquid to a web joined by the joining tape.

[0010]

In order to solve the above-mentioned problems, a bonding tape according to the present invention comprises a support and an adhesive layer applied or affixed to at least one surface of the support. In the above, fine irregularities are formed on the surface of the support on which the adhesive layer is provided. Thereby, the adhesive or the adhesive member is held by the tape base, and it is possible to prevent the adhesive from protruding from the tape base.
In addition, it is preferable that the uneven surface is formed of a groove arranged in a lattice, a groove arranged in a line, and minute holes arranged discretely.

More preferably, the opening width of the groove is 10 to 5000 μm, the depth of the groove is 2 to 300 μm, and the product thickness of the adhesive layer is 5 to 300 μm.

[0012] The present invention also includes a web joining method for joining an end of a web using a joining tape, wherein the joining tape described above is used.

Further, the present invention also includes a method of applying a web having a joining portion joined by a joining tape, wherein the method employs any of the joining tapes described above.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below. The tape base of the adhesive tape is made of polyethylene terephthalate (PET) or polyethylene naphthalate (PE) which has been subjected to coloring processing, translucent processing, or various kinds of vapor deposition processing.
N), polyimide, polypropylene (PP) and other plastic films, aluminum and other metal foils, various papers, and laminates thereof are mainly used. Among these materials, plastic films such as polyethylene naphthalate (PEN) and polyimide, various papers, and laminates thereof can be preferably used in the present invention. When used as a laminate, it is preferable to use the tape base material on the surface to which the adhesive is applied. Further, among them, polyethylene terephthalate (PET) is preferably used.

The thickness of the tape base is from 10 μm to 200
μm is preferred. More preferably, from 25 μm to 100
μm. Also, the width of the tape is not particularly limited,
It is preferably from 10 mm to 100 mm.

The fine irregularities on the adhesive-deposited surface of the tape base material according to the present invention can take various forms. In FIG.
An adhesive tape 43 in which a tape base 41 is provided with irregularities and an adhesive 42 is applied is shown. The tape base 41 is formed with a groove 41a having an arc-shaped cross section. This groove 41a
The tape base 41 is formed in a lattice shape or an oblique line shape. In the present invention, the shape of these grooves 41a,
There are no restrictions on size, depth, arrangement, etc. The groove 41a formed on the same surface of the tape base 41 has a shape,
The size, depth, etc. need not be the same. Groove 41
The size of “a” is preferably from 10 μm to 5000 μm in terms of the diameter of the groove (the diameter in the case of an arc, the representative diameter in other cases). More preferably, the groove is 30 μm to 1000 μm. If the size of the groove is too small, the diameter of the groove may be correspondingly reduced, and the effect of the groove holding the adhesive or the like does not occur. On the other hand, if the size of the groove is too large, the meaning of the groove is lost and the effect of holding the adhesive or the like does not occur. Further, the depth of the groove is suitably from 2 μm to 300 μm. If the groove is shallower, the effect of the groove is reduced. Also, if the depth of the groove is deeper than this, the adhesive will
It becomes difficult to apply. In this case, the thickness to which the adhesive is applied increases, which increases the cost, which is not preferable.

In the present invention, the cross section of the adhesive substrate on the tape substrate is not limited to an arc. For example, a groove having a trapezoidal cross section may be formed like the tape base material 45 of the adhesive tape 44 shown in FIG. 2, and the adhesive 42 may be applied to the groove. As another form, the adhesive tape 4 shown in FIG.
Like the tape base material 47 of No. 6, a groove having a triangular cross section may be formed and the adhesive 42 may be applied. Instead of the triangular cross section, a groove having a polygonal cross section (not shown) may be formed. Further, if the groove is formed in the tape base material at random without being patterned, the concave portion such as a conical shape can be arranged in a dot shape.

As described above, the unevenness of the groove, which is the surface on which the adhesive is provided, is filled with the adhesive 42 so that the adhesive tapes 43, 4
4, 46 are formed. As the adhesive 42, various commercially available ones, for example, an acrylic adhesive, an epoxy adhesive, a polyester adhesive, a polyurethane adhesive, a phenol adhesive, and the like can be used. However, in the present invention, the adhesive is not limited to these.

The applied thickness of the adhesive 42 is 5 μm to 300 μm, more preferably 8 μm to 100 μm, when the adhesive tape is completed. An extrusion coater, a roll coater, or the like is suitable as a method of coating the grooves. Further, the adhesive tape of the present invention may be an adhesive member in which a double-sided tape having an adhesive on both sides is attached instead of the adhesive. The adhesive applied to the tape substrate may be an adhesive, or a double-sided tape having an adhesive on both sides may be attached.

Next, a method for forming an adhesive tape by forming concaves and convexes in the tape base will be described with reference to FIG. The apparatus for forming the adhesive tape includes a heating roller 50, a pressure roller 51, an adhesive application section 52, and a dryer 53. After the tape base material 41 is heated by the heating roller 50, a groove 41 a (see FIG. 1) is formed on the surface of the tape base material 41 by the pressing roller 51, and the unevenness is provided. Subsequently, in the adhesive application section 52, the pickup roller 54 lifts the adhesive 42 from the adhesive tank 55. The adhesive 42 is coated by the coating roller 56 on the surface of the tape base 41 on which the irregularities are formed. Finally, the adhesive tape 43 is obtained while being dried while being conveyed by the rollers 57 in the dryer 53. In this way, pressure is applied to the surface of the tape base material 41 to plastically deform the tape base material 41 to form a depression on the surface, and then the adhesive is applied to form the adhesive tape 43.

FIG. 5 is a sectional view of a main part of the pressure roller 51 shown in FIG. As the pressure roller 51, an emboss roller having fine irregularities on the surface is used. Pressure roller 5
The grooves 41 a are formed on the surface of the tape base 41 by the plurality of minute projections 51 a provided on the surface of the tape base 41 being pressed against the tape base 41. Changing the pattern of the groove 41a
This can be easily achieved by replacing a pressure roller having a different pattern of minute projections. The protrusions of the pressure roller have many shapes such as a conical shape, a pyramid shape, and a truncated pyramid shape. The protrusions may be arranged regularly in a rectangular shape, or may be arranged in a random manner. The size of the projection is 8 to 6000 μm, more preferably 40 to 1300 μm. The pitch (average pitch in the case of random arrangement) is 8 to 600.
0 μm. The height of the projection is preferably from 3 to 400 μm, more preferably from 4 to 200 μm.

When the tape base is formed from a polymer such as PET, it is effective to heat the tape base with a heating roller or the like. Pressing the tape substrate while heating or immediately after the heating is a preferable method because a depression is formed in a short time. Heating, a method using a heating roller having a heating mechanism inside the pass roller,
A method of heating before pressurization using a heating furnace and a method of heating simultaneously with pressurization using the above-mentioned heating roller can also be used. However, even when a polymer such as PET is used for the tape substrate, it is not always necessary to heat. Further, the irregularities formed on the tape base material surface are not limited to being formed by pressing. If an adhesive that does not require a dryer is selected, the drying may be a method of natural drying.

FIG. 6 shows a state where the webs are joined by the adhesive tape 43 shown in FIG. The tape base 41 of the adhesive tape 43 has a surface formed with grooves 41a. Filling this groove 41a, the adhesive tape 43
The adhesive 42 is provided so that the surface of the substrate becomes smooth.
The webs 60 and 61 have their end faces approaching and facing each other, and the surfaces thereof are joined by an adhesive tape 43.
Further, the adhesive tape of the present invention can be applied to a joining method for joining both the front and back surfaces of the web as shown in FIG. Further, as shown in FIG. 9, the present invention can also be applied to a method in which a part of the web is overlapped and joined with an adhesive tape.

The method of applying a coating solution to a web bonded with an adhesive tape according to the present invention is a conventional coating apparatus (see FIG. 10).
Can be used. The web 21 is provided on the delivery device 20 by being joined by the adhesive tape of the present invention. The coating surface roller 2 is used to apply the coating liquid to the web 21.
No matter which of the rollers 2 and 28 and the opposite rollers 23 and 29 are squeezed, the adhesive does not protrude from the tape substrate because the adhesive is fixed by the unevenness of the tape substrate. In this case, the ironing force of the roller is absorbed by the elastic force of the polymer because the adhesive is formed of the polymer. For this reason, the protrusion of the adhesive due to the ironing action of the roller can be suppressed, the roller is not stained, and the application surface does not fail. Thus, according to the present invention,
It is possible to prevent the adhesive from protruding from the adhesive tape without improving the conventional coating machine.

FIG. 10 shows an embodiment using the extrusion coating method. However, the present invention can be used in any of a slide bead coating method, a curtain coating method, a bar coating method, a roll coating method, and the like in which a web is transported by a roller. Furthermore, the present invention is not limited to these methods, and can be applied to any device that rubs the adhesive tape with a roller.

[0026]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto. The execution conditions will be described in detail by a first embodiment. The materials and methods of Examples 2 to 4 and Comparative Examples 1 to 4 are the same as those of Example 1 unless otherwise specified.

Example 1 A polyethylene terephthalate (PET) film having a thickness of 40 μm and a width of 60 mm was used as a tape base of the adhesive tape. On one side of the tape substrate, arc-shaped grooves having a diameter of about 50 μm and a depth of 15 μm were formed at a pitch of 100 μm. Next, this P
An adhesive was applied to the surface of the ET film on which the groove was formed to prepare an adhesive tape. An acrylic adhesive was used as the adhesive. The web has a thickness of 70 μm and a width of 120 μm.
A 0 mm PET film was used. The end faces of the two webs were attached to each other, and the adhesive tape was attached to both the front and back surfaces of the two webs along the joined surfaces to form a sample. This sample was continuously applied by a coating machine including the bonding surface by an extrusion coating method. The application conditions were an application amount of 60 cc / m ² and an application speed of 70 m / min. The coating liquid was 10 parts by weight of an acrylic resin, 2 parts by weight of a pigment, and surfactant.
One having a composition ratio of 01 parts by weight, methyl ethyl ketone 65 parts by weight, methanol 20 parts by weight, and methylene glycol 5 parts by weight was used. After the application, the sample was taken out from the winding portion and the applied surface was observed, but there was no abnormality in the surface state. In addition, the end of the adhesive tape at the joint was checked in detail, but no protruding adhesive was found on the end face of the adhesive tape.

Comparative Example 1 A web was bonded under the same conditions as in Example 1 except that the surface of the tape substrate on which the adhesive was applied was a smooth surface, and application was performed under the same conditions. Observation of the applied surface after application showed that the application surface after the joint was 6 fine defects / m ² , and 10 foreign material adhesion defects / m ² .
m ² was observed.

Example 2 An adhesive tape was formed after forming a trapezoidal groove having a diameter of about 90 μm and a depth of 12 μm at a pitch of 200 μm on one side of a PET film as a tape base material. The sample was prepared by attaching two webs with the adhesive tape prepared in this example. A coating solution was continuously applied to this sample. After the application, the sample was taken out from the winding portion and the applied surface was observed, but there was no abnormality in the surface state. In addition, the end of the adhesive tape at the joint was confirmed in detail, but no protruding adhesive was found on the end face of the adhesive tape.

Comparative Example 2 A web was bonded under the same conditions as in Example 2 except that the surface of the tape substrate on which the adhesive was applied was a smooth surface, and application was performed under the same conditions. On the coated surface after the joint, fine repelling defects were found 6 / m ² , and foreign matter adhesion failures were found 10 / m ² .

Example 3 An arc-shaped groove having a diameter of about 80 μm and a depth of 30 μm was formed at a pitch of 200 μm on one side of a PET film as a tape base material, and then an adhesive was applied to form an adhesive tape. Created. A phenol type adhesive was used as the adhesive. The web also has a thickness of 12
A PET film having a size of 5 μm and a width of 1200 mm was used.
The sample was prepared by attaching two webs to each other with the adhesive tape prepared in this example. This sample has a coating weight of 7
Coating was performed continuously under the conditions of 0 cc / m ² and a coating speed of 70 m / min. After the application, the sample was taken out from the winding portion and the applied surface was observed, but there was no abnormality in the surface state. In addition, the end of the adhesive tape at the joint was confirmed in detail, but no protruding adhesive was found on the end face of the adhesive tape.

Comparative Example 3 A web was bonded under the same conditions as in Example 3 except that the surface of the tape substrate on which the adhesive was applied was a smooth surface, and application was performed under the same conditions. On the coated surface after the joint, fine repelling defects were found 5 / m ² , and foreign matter adhesion failures were found 9 / m ² .

Example 4 An arc-shaped groove having a diameter of about 50 μm and a depth of 18 μm was randomly formed on one side of a PET film as a tape base material at about 2,500 grooves / c on the surface of the film.
After forming m ² , an adhesive tape was prepared. Further, a sample was prepared by attaching the adhesive tape prepared in this example using two webs. A coating solution was continuously applied to this sample. After the application, the sample was taken out from the winding portion and the applied surface was observed, but there was no abnormality in the surface state. In addition, the end of the adhesive tape at the joint was confirmed in detail, but no protruding adhesive was found on the end face of the adhesive tape.

Comparative Example 4 A web was joined under the same conditions as in Example 4 except that the surface of the tape substrate on which the adhesive was applied was a smooth surface, and application was performed under the same conditions. Nine repellent defects / m ² and foreign matter adhesion defects 9 / m ^{2 were} observed on the coated surface after the joint.

[0035]

According to the bonding tape of the present invention, the adhesive or the adhesive is formed by forming irregularities on the surface of the tape substrate on which the adhesive is applied or on the surface of the tape substrate on which the adhesive member is adhered. The adhesive member is held in the concave portion of the tape base, so that the adhesive can be prevented from protruding from the tape base. Further, the joining tape of the present invention can be applied to joining a web and applying a coating liquid to the joined web.

[Brief description of the drawings]

FIG. 1 is a sectional view of an adhesive tape according to the present invention.

FIG. 2 is a sectional view of another embodiment of the adhesive tape according to the present invention.

FIG. 3 is a sectional view of another embodiment of the adhesive tape according to the present invention.

FIG. 4 is a schematic view of a production line for producing an adhesive tape according to the present invention.

FIG. 5 is a sectional view of a main part of a pressure roller for forming a groove of the adhesive tape according to the present invention.

FIG. 6 is a cross-sectional view in which webs are joined by the adhesive tape shown in FIG.

FIG. 7 is a side view showing an embodiment in which webs are joined by a conventional adhesive tape.

FIG. 8 is a plan view showing another embodiment in which webs are joined by a conventional adhesive tape.

FIG. 9 is a side view showing another embodiment in which webs are joined by a conventional adhesive tape.

FIG. 10 is a schematic view of an apparatus for applying a coating liquid to a web.

[Explanation of symbols]

 41, 45, 47 Tape base material 42 Adhesive 43, 44, 46 Adhesive tape 50 Heating roller 51 Pressing roller 51a Microprojection 52 Adhesive application part 53 Dryer 54 Pickup roller 55 Adhesive tank 56 Coating roller 60, 61 Web

Claims (5)

[Claims] 1. A bonding tape comprising a support and an adhesive layer applied or affixed to at least one surface of the support, wherein the surface of the support on which the adhesive layer is provided is subjected to fine unevenness processing. Bonding tape characterized by doing. 2. The bonding tape according to claim 1, wherein the uneven surface is formed of grooves arranged in a lattice, grooves arranged in a line, and minute holes arranged discretely. 3. An opening width of the groove is 10 to 5000 μm,
3. The groove according to claim 2, wherein the depth of the groove is 2 to 300 [mu] m, and the thickness of the adhesive layer in the product is 5 to 300 [mu] m.
The bonding tape as described. 4. A web joining method for joining an end portion of a web using a joining tape, wherein the joining tape according to any one of claims 1 to 3 is used. 5. A method for applying a web having a joining portion joined by a joining tape, wherein the joining tape according to any one of claims 1 to 3 is used.