JPH0578624A - Double-sided tacky tape and its production - Google Patents

Abstract

PURPOSE:To obtain a reapplicable and coreless silicone double-sided tacky tape having different tackinesses on both surfaces. CONSTITUTION:A reapplicable and coreless silicone double-sided tacky tape is obtained by applying a silicone tacky agent 2 containing a spherical silicone polymer 3 onto a release liner 4 and curing the tacky agent. Only one surface of the tacky agent layer 1 becomes a rough surface and tackiness differs between both surfaces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coreless double-sided silicone adhesive tape having different adhesiveness on both sides and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, an adhesive tape coated with a silicone adhesive has been used in various industrial fields because of its excellent heat resistance, cold resistance, durability and electrical insulation. This silicone adhesive tape includes a single-sided tape in which an adhesive is applied to one side of a base material, a double-sided tape in which an adhesive is applied to both sides of a base material or a core material, or both sides without a base material as shown in FIG. There is a form of a coreless (non-carrier) double-sided tape (transfer tape) composed of the adhesive layer A having the adhesive surfaces a and a. In the figure, B indicates a release liner having release agent layers c, c on both sides.

[0003]

Among them, transfer tapes of different types having different tackiness on both sides have not been developed so far. However, there is a strong market need for tapes of different adhesiveness on both sides, for example, one side of both sides has adhesiveness that can be replaced at the time of attaching work, and the other side has normal adhesiveness,
That is, development of a double-sided adhesive tape having a high initial adhesiveness is desired. That is, in the conventional transfer tape, since both sides have the usual adhesiveness, once it is pasted during the pasting work, even if a mistake is made, it cannot be easily peeled off, and it is extremely difficult to replace it. Not only was there a problem, however, it was not possible to make such a double-sided pressure-sensitive adhesive tape even when it was necessary to have different adhesive strengths on both sides.

Although it is not a silicone adhesive tape, a double-sided adhesive tape in which a glass balloon is blended with an acrylic adhesive and the adhesive surface is roughened, or a pigment is used as an acrylic adhesive, as a replacement. Although a double-sided pressure-sensitive adhesive tape is known in which the adhesive surface is roughened by blending the above-mentioned one, there are problems. That is, when glass balloons or pigments are blended with an acrylic pressure-sensitive adhesive, the adhesiveness and compatibility between the two are insufficient, and problems such as the glass balloons or pigments covering the adhesive surface and reducing the adhesive strength etc. There is. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems, to provide a double-sided adhesive tape without silicone core (non-carrier) which has different adhesiveness on both sides and which can be re-attached, and a simple manufacturing method thereof.

[0005]

As shown in FIG. 1, a double-sided pressure-sensitive adhesive tape of the present invention is a coreless double-sided pressure-sensitive adhesive tape comprising a pressure-sensitive adhesive layer 1 having both front and back surfaces as pressure-sensitive adhesive surfaces, wherein the pressure-sensitive adhesive layer 1 is a silicone pressure-sensitive adhesive. Consists of agent 2 and its one side 1
The spherical silicone polymer 3 is blended so that only a has a rough surface. Reference numeral 4 in the drawing denotes a release liner having both surfaces coated with a fluorosilicone release agent 5, which is attached to the other surface 1b side of the pressure-sensitive adhesive layer 1.

The present invention further provides a method for producing a coreless double-sided adhesive tape having different adhesive strengths on both sides, wherein a silicone adhesive 2 containing a spherical silicone polymer 3 is coated on a release liner 4, It is characterized by being cured. Even if a silicone pressure-sensitive adhesive containing no spherical silicone polymer is coated on a smooth release liner, the adhesiveness on both sides of the pressure-sensitive adhesive layer cannot be made different, but according to the production method of the present invention, the spherical silicone polymer is used. When 3 is mixed with silicone adhesive 2 and applied and cured,
The side 1b in contact with the smooth release liner 4 exhibits normal tackiness, but the concavo-convex formed by the spherical silicone polymer 3 is formed on the opposite surface 1a, and tackiness that can be replaced during sticking work is obtained. Further, the adhesive strength becomes different on both sides, and the adhesive strength on the opposite surface can be made lower than that on the surface in contact with the release liner 4.

As the silicone adhesive, known ones such as an organic peroxide curing type and a platinum type curing type can be used, and the type of the adhesive may be solvent type or solventless type.

As the spherical silicone polymer, for example, a polymer having rubber elasticity such as Tospearl (trade name) manufactured by Toshiba Silicone Co., Ltd. is used. In addition, spherical polymers other than silicone have heat resistance, cold resistance, durability,
It cannot be used because it impairs electrical insulation. The average particle diameter of the spherical silicone polymer is preferably 0.1 to 100 µ, and particularly preferably 1 to 60 µ. This is because if the average particle size is smaller than 0.1 μ, the effect on the removability and adhesiveness is small, and if it is larger than 100 μ, the adhesive strength is significantly reduced and it becomes practically unusable. Further, the compounding amount of the spherical silicone polymer is 0.5 to 105 parts by weight, preferably 10 to 50 parts by weight in terms of solid content relative to 100 parts by weight of the silicone adhesive. If the compounding amount of the spherical silicone polymer is less than 0.5 part by weight, effects such as ease of replacement cannot be obtained, and if it exceeds 105 parts by weight, the adhesive strength is significantly reduced, which is a practical problem. Is.

According to the production method of the present invention, the silicone adhesive compounded with the spherical silicone polymer needs to be coated on a smooth release liner, but the coating viscosity of the adhesive agent can be adjusted to various coating methods. It is necessary to select it according to need, and it is better that the viscosity is low. Also, the coating thickness of the adhesive is 5 to 1
00μ, preferably 20-60μ.

Further, the release liner is preferably a polyester film as a base material and a fluorosilicone release agent applied to the base material. The release liner is the same as that shown in FIG.
2 may be used, or the release liner 4 may be coated on one side with the release agent 5 as shown in FIG. As shown in FIG. 2, the pressure-sensitive adhesive 2 is applied to the surface of the release agent 5 of the single-sided release liner 4 and, after curing, the spherical silicone polymer 3
Then, another one-side treated liner 4 is attached to the 1a surface of the pressure-sensitive adhesive layer 1 on which irregularities have been formed, to form a one-side treated liner / adhesive / one-side treated liner, and the tape is wound. In this case, it is preferable that the single-sided treated liner 4 to be bonded has an uneven surface rather than a smooth surface.

The applied pressure-sensitive adhesive may be cured by heat, UV or EB, but heat curing is generally used.

[0012]

The silicone adhesive and the spherical silicone polymer have good compatibility and adhesiveness with each other, and good adhesiveness can be obtained without removing the spherical silicone polymer. Further, while glass balloons and pigments are hard and brittle substances, spherical silicone polymers are flexible with rubber elasticity, so they are easy to integrate with the flexibility of the adhesive,
Stable adhesive properties are obtained. Furthermore, when glass balloons and pigments are blended with the silicone adhesive, the original excellent characteristics of the silicone adhesive, such as heat resistance, cold resistance, and water resistance, are reduced, but with spherical silicone polymers there is almost no deterioration in physical properties. ..

[0013]

【Example】

Example 1 A silicone pressure-sensitive adhesive containing 30% by weight of a spherical silicone polymer having an average particle diameter of 2 μ (Toshiba Silicone Co., Ltd., trade name Tospearl 120) (Toray Dow Corning
Silicone Co., Ltd. product name SD4580) diluted with toluene is applied at a coating amount of 50 μ (dry) onto a double-sided release liner in which a fluorosilicone release agent is applied to both sides of a polyester film having a thickness of 50 μ, and then applied. , Heat cure at 130 ℃ for 2 minutes, wind this,
A coreless double-sided adhesive tape was prepared. As a result of examining the adhesiveness on both sides of this adhesive tape, the surface contacting the release liner at the time of heat curing showed normal adhesiveness with good initial adhesiveness,
The opposite surface showed tackiness that was easy to replace. By the way, the adhesive strength of each side (against polyethylene plate, polyester film 50μ lining, peeling speed 0.3m / min, 23
℃ 65% RH, 180 peel adhesive strength) is 280g / 20
mm and 150 g / 20 mm, coreless double-sided tapes having different tackiness on both sides were obtained.

Comparative Example 1 A coreless double-sided pressure-sensitive adhesive tape was prepared in the same manner as in Example 1 except that a silicone pressure-sensitive adhesive containing no spherical silicone polymer was used, but the pressure-sensitive adhesive strength on both sides of the pressure-sensitive adhesive layer was almost the same. Of course, it was not possible to obtain the replaceability.

As described above in detail, according to the double-sided pressure-sensitive adhesive tape of the present invention, a coreless silicone double-sided pressure-sensitive adhesive tape which has different adhesiveness on both sides and which can be replaced is obtained, and according to the production method of the present invention. There is an effect that such a double-sided adhesive tape can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the double-sided pressure-sensitive adhesive tape of the present invention.

FIG. 2 is a diagram showing the configuration of another embodiment of the double-sided pressure-sensitive adhesive tape of the present invention.

FIG. 3 is a diagram showing the structure of a conventional double-sided adhesive tape.

[Explanation of symbols]

 1 Adhesive Layer 1a One Side 1b Other Side 2 Silicone Adhesive 3 Spherical Silicone Polymer 4 Release Liner 5 Release Agent

Claims (6)

[Claims] 1. A coreless double-sided pressure-sensitive adhesive tape comprising a pressure-sensitive adhesive layer having both front and back surfaces as pressure-sensitive adhesive surfaces, wherein the pressure-sensitive adhesive layer is composed of a silicone pressure-sensitive adhesive, and a spherical silicone polymer is used so that only one surface thereof is roughened. A double-sided adhesive tape characterized by being blended. 2. The spherical silicone polymer has an average particle diameter of 0.1 to 100 μm, and the compounding amount thereof is 0.5 to 105 parts by weight with respect to 100 parts by weight of the silicone adhesive. The double-sided adhesive tape described. 3. The double-sided pressure-sensitive adhesive tape according to claim 1, further comprising a release liner coated with a fluorosilicone release agent. 4. The method for producing a double-sided pressure-sensitive adhesive tape according to claim 1, wherein a silicone pressure-sensitive adhesive containing a spherical silicone polymer is applied onto the release liner and cured. 5. The spherical silicone polymer having an average particle diameter of 0.1 to 100 microns is used, and the compounding amount thereof is 0.5 to 10 parts by weight with respect to 100 parts by weight of the silicone adhesive.
The manufacturing method according to claim 4, wherein the amount is 5 parts by weight. 6. The manufacturing method according to claim 4, wherein a release liner coated with a fluorosilicone release agent is used as the release liner.