JP2002317156A - Double-coated tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double coated tape which prevents air entrainment between adhesive tapes or an adhesive tape and a stuck material and can obtain a good adhesive state without a need of a large capital investment such as a vacuum booth. SOLUTION: In an adhesive film or an adhesive tape providing separating paper at least over the surface, a double-coated tape has layered adhesive layers by applying and drying of an adhesive on the surface of the separating paper wherein average roughness of 10 scores having continuous unevenness is not less than 10 μm to not more than 30 μm and the number of mountains per standard area is not less than 10/mm<2> to not more than 100/mm<2> , and a storage elastic modulus (G') of the adhesive at 20 deg.C is not less than 2.0×10<5> Pa.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided tape used for bonding a metal plate, a synthetic resin plate, a synthetic resin molded product, and the like.

[0002]

2. Description of the Related Art Conventionally, when a metal plate, a synthetic resin plate, a processed product thereof, and a synthetic resin molded product are bonded to the same or different members, the thickness of the support is reduced to one.
Adhesive tapes using a thin nonwoven fabric or a synthetic resin film of 00 μm or less and having an adhesive layer or an adhesive layer on both surfaces thereof, and an adhesive film made of an adhesive or an adhesive without using a support have been used. Adhesive tapes and adhesive films are mostly processed and bonded in the form of double-sided tapes with release paper on at least one side, but because of their good workability and simple bonding process, many industrial fields Used in

When bonding members such as a metal plate and a synthetic resin plate with a double-sided tape, the metal plate or the like is punched or cut in advance to a predetermined size, and is similarly punched or cut to a predetermined size. The double-sided tape processed as described above is bonded at a predetermined position by pressure bonding. At this time, air can be prevented from being entrapped between the double-sided tape and the metal plate or the like by applying pressure from one end to the other end on the release paper side provided on the back surface by a pressure roller or a finger pressure.

[0004] However, in the case where the above-mentioned bonded product from which the release paper has been peeled off is further bonded to a second adherend, pressure is applied in order from one end in accordance with the shape and hardness of the member to be adhered. Often can not do. For this reason, air is entrapped between the double-sided tape and the member, which may cause an adhesion failure such as blistering or insufficient bonding strength due to a reduction in the effective bonding area. Once the air has been swollen and swollen, the air may escape to the side and reduce blisters by applying strong crimping again.However, it is difficult to completely remove the air. Are left behind, and it is difficult to obtain a good adhesion state.

[0005] As a method for preventing the above-mentioned adhesion failure, there is a case where a double-sided tape using a foam base material as a support is used. Because the foam is used as a support, the double-sided tape itself has cushioning properties, and when pressed from one end, the tape itself is compressed and the lamination proceeds sequentially from one end,
It can be bonded without involving air. However, the foam base material double-sided tape increases in thickness, making it difficult to reduce the size of the member, and in addition, there is a problem that the bonded member is inclined or vibrated due to stress due to the cushioning property of the foam. .

[0006] As a measure for preventing air entrapment, it is effective to perform bonding under reduced pressure. If the process of bonding the tapes is performed under reduced pressure, the island-shaped unbonded portions generated due to insufficient pressure bonding immediately after the bonding disappear under normal pressure, and a good bonded state can be obtained.
However, when the bonding size is large or when the adherends need to be bonded continuously, a large-sized decompression booth is required, and a large capital investment is required. Although it is effective to reduce the pressure only in the bonding booth, it is necessary to carry in the member for each bonding unit and repeat degassing and leaking, and thus it is difficult to improve productivity.

[0007]

SUMMARY OF THE INVENTION The present invention prevents air from being trapped between the double-sided tape and the adherend at the time of lamination as described above, and does not require large-scale equipment investment such as a decompression booth. Another object of the present invention is to provide a double-sided tape capable of obtaining a good adhesive state.

[0008]

Means for Solving the Problems The double-sided tape of the present invention comprises:
10 points average roughness of 10μm or more and 30μ with continuous irregularities
m or less, the number of peaks per standard area is 10 / mm ² or more and 10
An adhesive film or an adhesive tape having an adhesive layer laminated by applying an adhesive and drying is laminated on the surface of the release paper of 0 / mm ² or less.
The storage elastic modulus (G ′) is 2.0 × 10 ⁵ Pa or more.

The details of the present invention will be described below. The double-sided tape of the present invention is an adhesive film or an adhesive tape provided with release paper on at least one surface, and has continuous unevenness on each surface where the adhesive film or the adhesive tape and the release paper come into contact, and the release paper comes in contact with the adhesive. Ten-point average roughness of the paper surface is 10 μm or more and 30 μm or less, and the number of peaks per standard area is 1
It is necessary that the number is not less than 0 / mm ^{2 and not} more than 100 / mm ² .

The double-sided tape of the present invention has a ten-point average roughness of 1
By forming an adhesive layer on the surface of a continuous uneven release paper having a peak area of 0 μm or more and 30 μm or less and a peak number per standard area of 10 pieces / mm ² or more and 100 pieces / mm ² or less, the unevenness of the release sheet is reduced. It can be obtained by transferring to an adhesive and forming an adhesive layer having unevenness equivalent to peeling on the surface of the adhesive. By forming continuous irregularities on the surface of the adhesive, air can escape from the concave portion during bonding and bonding, so that a large air pool does not occur on the bonded surface and a good bonding state can be obtained. It becomes possible.

Further, in order to transfer the irregularities of the release paper to the surface of the adhesive, an adhesive of a solution previously dissolved in a solvent or an emulsion solution dispersed in water is applied to the release paper and dried. It is necessary to form an adhesive layer. By applying the adhesive to the release paper in a solution state, the adhesive enters into the unevenness of the release paper without any gap, so that the surface of the dried adhesive may have the unevenness transferred from the unevenness of the release paper. it can.

There is also a method of laminating an adhesive layer or a double-sided tape prepared in advance on a release paper having irregularities and transferring the irregularities to the adhesive layer. Therefore, it is difficult to transfer irregularities sufficiently even when the laminating temperature and speed are controlled, and it is not possible to efficiently form irregularities equivalent to the release paper on the adhesive surface. There is also a method in which a hot-melt type adhesive is melt-extruded with a T-die extruder or the like and applied to the uneven surface of the release paper, but air slightly remaining in the concave portion is heated by the heat of the hot-melt adhesive. It is not preferable because it swells and causes blisters to inhibit the formation of irregularities on the surface of the adhesive.

The irregularities on the surface of the release paper used must have a ten-point average roughness of 10 μm or more and 30 μm or less, and the number of peaks per standard area should be 10 / mm ² or more and 100 / mm ² or less.

If the ten-point average roughness is 10 μm or less, there is no effect of unevenness, and the wetting proceeds at the moment when the adhesive film or adhesive tape from which the release paper is peeled is attached to the second adherend. Then, air is partially entrained before crimping. On the other hand, if the ten-point average roughness is more than 30 μm, the air in the concave portion remains in the form of islands on the entire surface even after bonding to the adherend and pressure bonding, and the effective bonding area cannot be increased.

The number of peaks per standard area is 10 / mm.
^If it is less than ² , the number of recesses that become air passages at the time of crimping is small, and the passage of air further decreases as the crimping proceeds, so that the air cannot be sufficiently removed and the effect of preventing air entrapment is not exhibited. . When the number of peaks per standard area exceeds 100 / mm ² , air is likely to be included when the adhesive is applied to the release paper, and air bubbles enter the adhesive to obtain a uniform adhesive layer. Not only can not be performed, but also air enters the release paper and the surface of the adhesive, and there are portions where irregularities of the release paper cannot be transferred to the surface of the adhesive. In addition, when peeling the release paper, there is a problem that the adhesive is caught by the unevenness of the release paper, making it difficult to remove the release paper. Further, the irregularities need to be continuous. If the irregularities are independent or partially independent, air will accumulate in the recess after bonding.

The double-sided tape used in the present invention may be a so-called adhesive film having a single adhesive layer as described above, or may be an adhesive tape having a two-layer adhesive layer via a support. , In contact with the release paper as described above,
The storage elastic modulus (G ′) at 20 ° C. of the adhesive layer on the side to which the second adherend is bonded needs to be 2.0 × 10 ⁵ Pa or more.

The storage elastic modulus at 20 ° C. of the adhesive layer is 2.0
When the pressure is less than × 10 ⁵ Pa, it is difficult to maintain the shape of the unevenness after peeling off the release paper, the unevenness disappears, and the effect of preventing air entrapment cannot be obtained.

In the present invention, as the kind of the adhesive layer, both a pressure-sensitive type and a heat-activated adhesive type can be used. In the pressure-sensitive type, acrylic acid ester copolymers, styrene block copolymers, butyl rubber, styrene butadiene rubber, natural rubber, etc. can be used. Those based on copolymers and styrenic block copolymers are preferred. In the case of the heat activated adhesive type, a resin mainly composed of a urethane-based resin, a polyester-based resin, chloroprene rubber, or the like can be used, and it can be appropriately selected according to an adherend and characteristics required for adhesive strength. In the present invention, it is also possible to prevent air entrapment by bonding a double-sided tape to both sides of a member to be bonded, and bonding the peeled surfaces having irregularities to each other.

[0019]

Embodiments of the present invention will be described below. In addition, "parts" in the composition indicates parts by weight. (Example 1) The following composition (1) containing a pressure-sensitive type acrylate copolymer as a main component was applied onto a strong matte release paper CPM-7 manufactured by Lintec Co., Ltd., and then 100 ° C.
After drying for 2 minutes, a double-sided tape having an adhesive layer having a thickness of about 50 μm was obtained.

(Formulation 1) SK Dyne 1386 (manufactured by Soken Chemical Co., Ltd., acrylic adhesive) 100 parts Coronate L (manufactured by Nippon Polyurethane Co., Ltd., isocyanate-based crosslinking agent) 1 part

Example 2 Using the following composition (2) containing a styrene-based block copolymer as a main component (Example 1)
Under the same conditions as above, a double-sided tape was obtained.

(Blend 2) Carifrex TR1107 (Shell Chemical Co., styrene block copolymer) 100 parts Super Ester A125 (Arakawa Chemical Co., Ltd., rosin ester resin) 55 parts HARKOTAC 1149 (Rika Hercules, C5 series) Petroleum resin) 35 parts Toluene 130 parts

(Example 3) The following compound (3) containing a polyester-based heat-active adhesive as a main component was coated on a strong matte release paper EKR90M-7 manufactured by Lintec Co., Ltd.
It was dried at 00 ° C. for 2 minutes to obtain a double-sided tape having an adhesive layer having a thickness of about 50 μm.

(Formulation 3) Hybon 7663 (Hitachi Chemical Polymer, polyester-based heat-active adhesive) 100 parts Coronate L (Nippon Polyurethane, Isocyanate-based cross-linking agent) 5 parts

(Embodiment 4) 1 is applied to the surface of the pressure-sensitive adhesive of (Example 1).
A 2 μm polyester film is laminated, and the other side of the polyester film is coated with a blending (1) on a polyester film base paper GS25 manufactured by Lintec Co., and a 50 μm adhesive film obtained by drying is laminated. A double-sided tape was obtained.

(Comparative Example 1) A double-sided tape was obtained in the same manner as in Example (1) except that a polyester film base release paper GS25 manufactured by Lintec was used for release paper.

(Comparative Example 2) Linf P
E-laminated woodfree base paper release paper EN56 (G0-0
A double-sided tape was obtained in the same manner as in Example (2) except that 9) was used.

Comparative Example 3 Using the following composition (4) containing an acrylate copolymer as a main component (Example 1)
Under the same conditions as above, a double-sided tape was obtained.

(Formulation 4) Oribain BPS 5331 (Toyo Ink, acrylic adhesive) 100 parts Coronate L (Nippon Polyurethane, Isocyanate crosslinking agent) 1 part

(Evaluation Test) The air was entangled by laminating a double-sided tape to an ABS plate having a thickness of 3 mm using a laminator, cutting it into a size of 50 × 50 mm, and peeling off a release paper having irregularities. The adhesive surface was attached to a glass plate having a thickness of 5 mm,
Crimping was performed at 0 ° C. and 50 kN / m ² for 60 seconds, and the presence or absence of air from the glass surface was visually checked. ；: No air entrapment ×: Judged that air was entrained.

The ten-point surface roughness and the number of peaks per standard area of the release paper were measured using a contact type three-dimensional roughness measuring instrument (manufactured by Kosaka Laboratory Co., Ltd.).

The storage elastic modulus (G ') of the adhesive was determined by measuring the shear storage elastic modulus at a frequency of 1 Hz using a viscoelasticity measuring device. Below, the evaluation results

The results are shown in Table 1.

[0033]

[Table 1]

[0034]

According to the present invention, it is possible to prevent air from being trapped between an adhesive film or an adhesive tape and an adherend, and to obtain a good adhesive state without requiring large-scale equipment investment such as a decompression booth. It is possible to provide a double-sided tape that can be used.

[Brief description of the drawings]

 1 and 2 are cross-sectional views of the double-sided tape.

FIG. 1 shows a double-sided tape composed of an adhesive film and release paper.

FIG. 2 shows a double-sided tape composed of an adhesive tape and release paper.

[Explanation of symbols]

 1. 1. Release paper 2. Adhesive layer Support 4. Adhesive layer 5. Adhesive tape 21. Adhesive film (adhesive layer)

Claims (1)

[Claims] 1. An adhesive film or an adhesive tape provided with release paper on at least one surface thereof, has continuous irregularities, has a 10-point average roughness of 10 μm or more and 30 μm or less, and has a number of peaks per standard area of 10 / mm ² or more. 100 pieces / mm ²
An adhesive layer laminated by applying and drying an adhesive on the surface of the following release paper,
A double-sided tape having a storage elastic modulus (G ′) of 2.0 × 10 ⁵ Pa or more.