JPH0797552A - Production of double-faced tacky adhesive tape - Google Patents

Abstract

PURPOSE:To provide a process for the continuous production of a double-faced tacky adhesive tape by covering a tacky adhesive layer with a releasing paper and covering the other tacky adhesive layer with a releasing paper having a releasing force to the tacky adhesive layer different from the releasing force of the former releasing paper and giving a wound roll by the continuous releasing of one of the releasing papers without generating a void between the other releasing paper and the tacky adhesive layer. CONSTITUTION:The upper surface of the 1st releasing paper 1 is subjected to a static treatment at 0.5-8KV to form a static-treated layer 8 and increase the adhesive force (or releasing force) between the paper and the 1st tacky adhesive layer 9 formed on the treated layer. The releasing force between the 1st releasing paper and the 1st tacky adhesive layer becomes different from the releasing force between the 2nd releasing paper 12 and the 2nd tacky adhesive layer 13 by this process to prevent the generation of void between the 1st releasing paper 1 and the 1st tacky adhesive layer 9 in the releasing of the 2nd releasing paper 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a double-sided pressure-sensitive adhesive tape in which a pressure-sensitive adhesive layer is formed on both sides of a substrate, and in particular, it is possible to prevent the peeling force of release paper from decreasing with time. The present invention relates to a method for producing a double-sided pressure-sensitive adhesive tape in which the peeling force of each release paper laminated on each pressure-sensitive adhesive layer is different.

[0002]

2. Description of the Related Art An example of a conventional method for producing a double-sided adhesive tape will be described with reference to FIG. As shown in FIG. 2 (a), first, a pressure-sensitive adhesive is applied to one surface of a first release paper a whose surface has been subjected to a release treatment with a release agent such as silicone, and dried to form a first adhesive. A layer b is formed, and a tape base material c made of non-woven fabric or the like is laminated on the first pressure-sensitive adhesive layer b to form a primary original fabric d.

On the other hand, as shown in FIG. 2B, a second release paper e which is similarly subjected to a release treatment is prepared, and an adhesive is applied and dried on one surface of the second release paper e to form a second adhesive layer. f is formed and the secondary original fabric g is shape | molded. Then, as shown in FIG. 2C, on the surface h of the tape base material c on which the first adhesive layer b of the primary original fabric d is not formed, the second adhesive layer of the secondary original fabric g is formed. Laminate so that f is overlapped. Thus, the double-sided adhesive tape t can be obtained.

The double-sided pressure-sensitive adhesive tape t thus obtained is peeled off from the second pressure-sensitive adhesive layer f from the second release paper e in the next step and wound around a core or the like to be processed into a product of a roll. Alternatively, the release papers a and e may be punched into various shapes while being stuck to each other, and the products having the same shape may be processed into a stacked product by stacking them together.

By the way, when the second release paper e is released from the second adhesive layer f, as shown in FIG.
A gap may occur between the first pressure-sensitive adhesive layer b and the first release paper a along with the peeling. This is a phenomenon called "tape lifting". When such tape floating occurs, when the second release paper e is peeled off and then wound around a core or the like, the double-sided adhesive tape t cannot be stably wound, and the non-defective rate decreases.

Therefore, in order to prevent such a tape floating phenomenon, a method (hereinafter referred to as "differential peelability") in which the peeling forces of the first and second release papers a and e are made different is developed. However, since this is not a perfect technology, the applicant has developed one technology that can obtain effective results after repeated research in order to fundamentally solve this problem. −
No. 51563). The main point of this technique is that the surface of the first release paper on which the first pressure-sensitive adhesive layer is formed is subjected to corona discharge treatment in advance, and then the first pressure-sensitive adhesive layer is formed. By doing so, a large peeling force is formed on the first release paper by the blowing of the ionic wind during the corona discharge treatment, and the peeling force does not decrease with time and is a stable difference. It retains peelability.

[0007]

However, in order to perform the corona discharge treatment, generally, for example, a grounded metal roll that supports and transfers the object to be treated is used as one electrode, and a large number of needle-shaped electrodes are opposed to it. A device is used in which electrodes are provided and a high DC voltage (usually 4 to 8 KV) is applied between the electrodes to perform corona discharge. In other words, it is a type of plasma processing method, requires the above-mentioned electrodes, high-voltage transformers, transmitters, and other equivalent equipment, and not only increases equipment costs and maintenance costs, but also requires specialized processing technology. It requires the installation of professional engineers.

Further, in the above-mentioned prior art, it is indispensable to use silicone as a treating agent used for the first release paper, and among them, non-migrating type silicone is preferable. Then, there is a problem that the release agent used for the second release paper depends on the form of the product. From the standpoint of the manufacturing side, it goes without saying that using the same release agent is advantageous in terms of manufacturing and cost.

The present invention solves the above-mentioned drawbacks of the prior art,
No specific release agent is required, and even if the release agents used for the first and second release papers are the same, different release properties can be obtained without any problems in terms of production and quality. The present invention has been made for the purpose of providing a method for producing a double-sided pressure-sensitive adhesive tape.

[0010]

According to the present invention, "a surface of a first release paper is subjected to an electrostatic treatment of 0.5 to 8 KV, and a first pressure-sensitive adhesive layer is formed on the surface to be electrostatically treated. Laminating a tape base material on one pressure-sensitive adhesive layer to form a primary original fabric,
A step of forming a second adhesive layer by forming a second pressure-sensitive adhesive layer on one surface of the second release paper, and the primary raw material, on the tape substrate surface on which the first pressure-sensitive adhesive layer is not formed, "The method for producing a double-sided pressure-sensitive adhesive tape, which comprises laminating a second pressure-sensitive adhesive layer of a secondary original fabric".

That is, the essence is to provide differential peelability by simply performing electrostatic treatment instead of corona discharge treatment, that is, one surface on the first release paper, When an electrostatic charge is applied, a functional group such as an OH group is generated on the one surface, oxygen and moisture in the air are easily attached to the functional group, and the peeling force is improved due to considerable activation. In this respect, since it does not directly depend on the attractive force of static electricity, if the adhesive layer is formed, the peeling force does not decrease even if static electricity disappears.

As the release agent used in the present invention,
It does not matter if the first and second release agents are the same, and there is no requirement for a specific release agent, and an appropriate release agent is selected and used according to the product form and application. can do. However, from various viewpoints, silicone-based ones, especially exposure-type silicones are preferable. The exposure type refers to a silicone treated surface to which water or dust is likely to adhere.

The electrostatic voltage in the case of the electrostatic treatment performed in the present invention is required to be in the range of 0.5 to 8 KV, and if it is less than 0.5 KV, the desired differential peeling property cannot be obtained.
On the other hand, if it exceeds 8 KV, for example, when silicone is used, the releasability is lost for the reason that is considered to be due to modification of siloxane, and the function as a double-sided pressure-sensitive adhesive tape is not exhibited.

As means for performing the electrostatic treatment, an insulating material such as a silicone rubber roll is provided between the position where the release paper is rewound from the roll and the coating machine for forming the first adhesive layer. A method in which one or more rolls made of a material is disposed and friction is caused between the release paper and the surface of the release paper to be triboelectrically charged, or to discharge from a grounded discharge cloth, or a combination of these means is used. There are ways to do it. Further, as a method of adjusting the static voltage, there are a method of adjusting the type of cloth for the static elimination cloth, a distance between the static elimination cloth and the release paper, a method of adjusting the strength of the static elimination air, and the like.

The pressure-sensitive adhesive, tape base material, release base paper and the like used in the production method of the present invention are not particularly limited, and those generally used for double-sided pressure-sensitive adhesive tapes can be used as they are. For example, as the release base paper, a high-quality paper laminated with polyethylene resin or the like is suitable.

[0016]

According to the present invention, one surface of the first release paper is subjected to electrostatic treatment with a treatment voltage in a specific range, and then the first adhesive layer is formed on the electrostatic treatment surface. The surface of the release agent layer is considerably activated by the electrostatic treatment, the release force of the first adhesive layer formed thereon is improved, and the release agent used for the first release paper is Even if the release agent used for the release paper is the same, the differential release property is imparted between the two.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings.

In FIG. 1 (a), reference numeral 1 denotes one surface of a release base paper obtained by laminating polyethylene on both surfaces of high-quality paper,
Silicone as a release agent (Shin-Etsu Chemical Co., Ltd., product number = K
S-776A) is applied and dried to form a first release paper. 2 is a roll body of the first release paper 1, 3, 3, ...
A static electricity treatment roll having at least a surface on which a silicone rubber roll layer is formed, 4 is a grounded discharge cloth, 5 is a discharge rod, 6 is a delivery roll for coating, and 7 is an adhesive coater. In the case of the example, an acrylic solvent-based pressure-sensitive adhesive (manufactured by Soken Chemical Industry Co., Ltd., product number = SK Dyne-1717) was used.

Then, while rewinding the first release paper 1 from the roll body 2 of the first release paper 1, the discharge cloth 4 discharges the surface on which the first adhesive layer is to be formed. The first release paper 1 is passed through the five electrostatic treatment rolls 3, 3, ... And in the process, the potential is made higher than 5 to discharge and is fed to the pressure-sensitive adhesive applicator 7 via the delivery roll 6. Then, the pressure-sensitive adhesive was applied so that the coating thickness after drying was 65 μm, and dried to form a first pressure-sensitive adhesive layer.

All the following steps were performed using a conventionally known device and method (not shown). That is, a tape base material made of a paper pulp non-woven fabric (manufactured by Nippon Paper Industries Co., Ltd., SPC base paper) was laminated on the obtained sheet having the first pressure-sensitive adhesive layer to form a primary stock. Separately, the second pressure-sensitive adhesive layer is applied to the same side of the second pressure-sensitive adhesive release paper 1 as the first pressure-sensitive adhesive layer with the same pressure-sensitive adhesive as the first pressure-sensitive adhesive layer and dried to form the second pressure-sensitive adhesive layer. To form a secondary web, and a second adhesive layer of the secondary web is laminated on the tape substrate surface on which the first adhesive layer of the primary web is not formed. A double-sided adhesive tape sample T was manufactured.

The structure of the obtained double-sided adhesive tape T is shown in FIG.
Shown in (b). In the figure, an electrostatic treatment layer 8 is formed on one surface of the first release paper 1. Reference numeral 9 is a first pressure-sensitive adhesive layer, 10 is a tape base material, and thus the primary original fabric 11 is constituted. Further, 12 is a second release paper, 13 is a second pressure-sensitive adhesive layer, and thus the secondary original fabric 14 is constituted. The thin layers present on both sides of each release paper 1 and 12 are laminate layers.

In the case of this embodiment, the first release paper 1
The amount of charge on one side was adjusted in two cases by adjusting the type of cloth for static elimination cloth, the distance between the static elimination cloth and the release paper, and the strength of the static elimination wind. . First 1.
The sample tape was manufactured by setting it to 5 KV, and then 7.0
A sample tape was manufactured in the same manner with KV set.

As a comparative example, the charge amounts on one surface of the first release paper 1 are set to be 0, 0.3, and 10.5 KV, respectively, and other three are the same as in the embodiment. A double-sided adhesive tape sample was prepared.

Then, the differential peelability was evaluated for the sample tapes of these Examples and Comparative Examples. As an evaluation method, when the second release paper was peeled from each of the obtained sample tapes, did the tape floating phenomenon occur between the first adhesive layer and the first release paper? Whether or not it was visually observed and evaluated. The results are shown in Table 1.

[0025]

[Table 1]

[0026]

According to the present invention, one surface of the first release paper is subjected to electrostatic treatment and the first adhesive layer is formed on the electrostatically treated surface. Therefore, the surface of the release agent layer is treated by the electrostatic treatment. Is considerably activated, the peeling force of the first pressure-sensitive adhesive layer formed thereon is improved, and a release agent used for the first release paper,
Even if the release agent used for the second release paper is the same, the differential release property is provided between the two.

Therefore, as the first pretreatment method for the release paper, it is sufficient to simply perform the electrostatic treatment, the equipment cost for imparting the differential peelability is low, and the special energy cost is not required. Since no special operation technique for the above is required, a double-sided pressure-sensitive adhesive tape having differential peelability can be manufactured at low cost. Furthermore, even if the same release agent is used for the release paper on both sides, the desired effect can be obtained, and it can be said that the manufacturing cost can be reduced also from this point.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing only a main part of an apparatus suitable for carrying out a manufacturing method of the present invention.

FIG. 2 is a partially cutaway cross-sectional view showing an example of a double-sided pressure-sensitive adhesive tape manufactured using the apparatus shown in FIG.

[Explanation of symbols]

 1 First Release Paper 2 First Release Paper Roll 3 Electrostatic Treatment Roll 4 Discharge Cloth 5 Discharge Rod 6 Delivery Roll 7 Adhesive Coating Machine 8 Electrostatic Treatment Layer 9 First Adhesive Layer 10 Tape Base Material 11 Primary Fabric 12 Second Release Paper 13 Second Adhesive Layer 14 Secondary Fabric T Double-sided Adhesive Tape Made by the Manufacturing Method of the Present Invention

Claims (1)

[Claims] 1. The surface of the first release paper is 0.5 to 8 KV.
The step of forming a first adhesive layer on the electrostatically treated surface, laminating a tape base material on the first adhesive layer to form a primary sheet, and a second peeling step. A step of forming a second adhesive sheet by forming a second adhesive layer on one side of the paper, and a secondary original sheet on the tape substrate surface of the primary original sheet on which the first adhesive layer is not formed. 2. A method for producing a double-sided pressure-sensitive adhesive tape, which comprises laminating a second pressure-sensitive adhesive layer as described above.