JPH07224263A - Production of pressure-sensitive adhesive double coated tape - Google Patents

Abstract

PURPOSE:To provide a process for producing a pressure-sensitive adhesive double coated tape using Japanese paper as a support, which provides rapid coating and high productivity and is suitable for applications where removability is required. CONSTITUTION:A pressure-sensitive adhesive layer formed of a resin is formed by transfer on both sides of Japanese paper impregnated with a resin. The resin for constituting the pressure-sensitive adhesive layer is of the same type as the resin impregnated into the Japanese paper. The use of creped Japanese paper makes it possible to produce pressure-sensitive adhesive double coated tape which is less likely to be broken when pulled at the time of removal.

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 based on Japanese paper.

[0002]

2. Description of the Related Art Double-sided adhesive tape using Washi as a support is
It is widely used for applications that require removability. The removability refers to a property that, when the pressure-sensitive adhesive tape attached to the adherend is peeled off, the support can be peeled without leaving the pressure-sensitive adhesive on the adherend without damaging the support. The application requiring removability is, for example, as shown in FIG. 1, after attaching one side of the double-sided adhesive tape 2 to the surface of the recycle-use adherend 1 made of a plastic plate or metal to be recycled. The adherend 3 that is not recycled is attached to the other surface of the tape for use, and after use, the adherend 3 is recycled together with the double-sided adhesive tape 2 together with the adhesive layer of the double-sided adhesive tape 2. This indicates an application in which the recycled adherend 1 to be peeled off from the adherend 1 to be used is reused.

Among the methods for producing a double-sided tape, those using a non-woven fabric, a plastic film, a plastic foam or the like as a support are generally coated with an adhesive on one side of a release sheet from the viewpoint of productivity and safety. , A pressure-sensitive adhesive layer with a release sheet, which is dried to form a pressure-sensitive adhesive layer, is laminated on both sides of a support,
A method in which the pressure-sensitive adhesive layer is transferred to both surfaces of the support by pressure bonding is used (Adhesion Handbook, pages 165 to 167,
Japan Adhesive Tape Manufacturers Association, issued March 2, 1985).

However, when the support is Japanese paper, the basis weight is larger than non-woven fabric and the like, and the material is dense. In the transfer method as described above, the adhesive hardly impregnates the Japanese paper.
If the adhesive is not impregnated into the washi paper, if it is used for removability, the layers of the washi will be destroyed at the time of peeling and the adhesive layer and a part of the washi paper will remain on the adherend side for recycling. Cannot be used again. Therefore, in the production of a double-sided pressure-sensitive adhesive tape using Washi as a support, a dip coating method in which Washi is passed through a pressure-sensitive adhesive liquid and the pressure-sensitive adhesive is immersed in Washi is adopted.

[0005]

However, although the dip coating method is excellent in that the coating process can be completed only once, high-speed coating is impossible because it takes time to dry,
There was a problem of low productivity. The present invention has been made in view of the above problems, and an object thereof is to enable high-speed coating of a pressure-sensitive adhesive by a transfer method, have high productivity, and be suitable for use where re-peeling is required. Another object of the present invention is to provide a method for producing a double-sided adhesive tape using Washi as a support.

[0006]

A method for producing a double-sided pressure-sensitive adhesive tape according to the first aspect of the present invention is to form a pressure-sensitive adhesive layer made of the same resin as the resin on both sides of a resin-impregnated Japanese paper by a transfer method. Is characterized by.

The method for producing the double-sided adhesive tape of the second invention is
The method for producing a double-sided adhesive tape according to claim 1, wherein the Japanese paper is creped.

The method for producing the double-sided adhesive tape of the third invention is
A method for producing a double-sided pressure-sensitive adhesive tape in which a pressure-sensitive adhesive layer is formed on both sides of Japanese paper by a transfer method is characterized in that transfer is performed under a temperature condition of 80 ° C. or higher.

The first invention will be described in detail below.
Examples of the resin used for producing the Japanese paper impregnated with the resin in the first invention include acrylic type and rubber type. Washi has a basis weight of 30 to 80 g / m
² , those having a thickness of 50 to 100 μm are preferable.

In order to impregnate the Japanese paper with the resin, a method of immersing the Japanese paper in a resin solution having a solid content concentration of 5 to 60% by weight, pulling it up, and drying it to evaporate the solvent, water and the like can be mentioned.

The ratio of the Japanese paper to the resin of the Japanese paper impregnated with the resin and dried is such that the resin is 2 parts by weight based on 100 parts by weight of the Japanese paper.
0 to 50 parts by weight is preferred. When the proportion of the resin is high, the impregnated and dried Japanese paper is rolled and stored, and the blocking becomes strong and the development becomes difficult.

The pressure-sensitive adhesive used for producing the pressure-sensitive adhesive layer in the first invention must be made of the same type of resin as the resin impregnated in the Japanese paper. The "same type" is meant to include not only the case where both are the same but also the case of the same system. The same system means that if one is an acrylic resin, the other is also an acrylic resin, and if one is a rubber resin, the other is also a rubber resin. In this way, by using the same type of resin, the two adhere well.

The method for producing the double-sided adhesive tape of the first invention is
First, a pressure-sensitive adhesive layer is applied to a release sheet with, for example, a roll coater or a knife coater, and dried to evaporate a solvent or the like to produce a pressure-sensitive adhesive layer with a release sheet. The thickness of the pressure-sensitive adhesive layer after drying is preferably 40 to 90 μm. The release sheet is not particularly limited, and examples thereof include kraft paper and high-quality paper laminated with a plastic film, which is treated with silicone, and glassine paper which is treated with silicone.

Next, the pressure-sensitive adhesive layer with the release sheet is laminated on both sides of the above-mentioned resin-impregnated Japanese paper, and then pressure-bonded by a roll or the like so that the pressure-sensitive adhesive layer is sufficiently fixed on both sides of the Japanese paper. Transfer the agent layer to Japanese paper. Next, peel off the release sheet attached to the adhesive layer and stack other release paper, or
Alternatively, the release sheet attached to the pressure-sensitive adhesive layer is not peeled off but is attached as it is to obtain a product.

Next, the second invention will be described. The second invention is that, as the Japanese paper used in the method for producing the double-sided pressure-sensitive adhesive tape of the first invention, crepe-processed Japanese paper is used,
A double-sided pressure-sensitive adhesive tape having the same configuration as the first invention and using the crepe-processed Japanese paper can be manufactured by the same method as in the first invention. The double-sided pressure-sensitive adhesive tape obtained by the production method of the first invention may cause tape breakage when the pulling speed is increased during re-peeling, but the double-sided pressure-sensitive adhesive tape obtained by the second invention was pulled during re-peeling. Sometimes it will be difficult for the tape to break.

The crepe-processed Japanese paper used in the second invention is a Japanese paper that has been creped and preferably has an elongation in the longitudinal direction of the tape of 7 to 20%. If the elongation in the longitudinal direction of the tape becomes small, the double-sided pressure-sensitive adhesive tape is likely to break when pulled at the time of re-peeling, and if it becomes large, the current crepe processing technology has a problem in productivity during crepe processing.

In the third invention, the Japanese paper may be impregnated with resin as the Japanese paper in the first and second inventions. In this case, the adhesiveness between the resin and the resin of the pressure-sensitive adhesive layer to be transferred. Is particularly preferable because of high value. However, even if the Japanese paper is not impregnated with the resin, the resin of the pressure-sensitive adhesive layer softens under the temperature condition of 80 ° C. or higher, so that it easily enters between the fibers of the Japanese paper and becomes as if impregnated. More preferably, the Japanese paper is creped.

The release paper for forming the pressure-sensitive adhesive layer has a polyethylene layer provided on a paper base material, and is subjected to a release treatment with a silicone resin or the like. If the transfer temperature exceeds 110 ° C, the polyethylene layer will melt and the release layer will be destroyed.
It is preferable to carry out the treatment in a range not exceeding ° C. In order to transfer the pressure-sensitive adhesive layer under a temperature condition of 80 ° C. or higher, a method of heating the laminating roll is preferable because the heating is uniform and efficient.

[0019]

According to the production method of the first invention, since the Japanese paper is impregnated with the resin in advance, the double-sided adhesive tape suitable for re-peeling use can be produced even if the adhesive layer is formed by the transfer method.

According to the production method of the second invention, since the Japanese paper is impregnated with the resin in advance, even if the adhesive layer is formed by the transfer method, the double-sided adhesive tape suitable for re-peeling use can be produced, and Since the Japanese paper is creped, the double-sided pressure-sensitive adhesive tape is less likely to break because the tape stretches and the stress is dispersed even if it is pulled at a high speed during re-peeling.

According to the manufacturing method of the third invention, when the pressure-sensitive adhesive layer on the release paper is transferred to the Japanese paper at a temperature condition of 80 ° C. or higher, the pressure-sensitive adhesive layer softens and enters between the fibers of the Japanese paper, It is possible to produce a pressure-sensitive adhesive tape having a strong bond between the adhesive tape and the adhesive layer.

[0022]

EXAMPLES Examples of the present invention will be described below. In addition, Example 1 and Example 2 are examples of the first invention, Example 3 is an example of the second invention, and Examples 4 and 5 are examples of the third invention. Example 1 (a) Preparation of resin-impregnated Japanese paper Acrylic resin (manufactured by Japan Synthetic Rubber Co., Ltd., trade name: AE11)
6) in 40% by weight of ethyl acetate solution, Japanese paper (basis weight 50
g / m ² , thickness 70 μm, manufactured by Daifuku Paper Co., Ltd., product name: DP
After soaking the base paper for 30 seconds, pull it up and put it at 100 ° C for 5
The resin-impregnated Japanese paper was obtained after drying for a minute. The amount of acrylic resin impregnated was 20 g / m ² . (B) Preparation of pressure-sensitive adhesive layer with release sheet Release sheet (thickness 120 μm, manufactured by Fujimori Industry Co., Ltd., product name:
SYA) with acrylic adhesive (manufactured by Soken Chemical Industry Co., Ltd., trade name: S
A 45 wt% ethyl acetate solution of Kdyne-1717) was applied so that the thickness after drying would be 65 μm, and 10
It dried at 0 degreeC for 5 minutes, and obtained the adhesive layer with a release sheet. (C) Production of double-sided pressure-sensitive adhesive tape The pressure-sensitive adhesive layer with the release sheet obtained in the step (b) is laminated on both sides of the resin-impregnated Japanese paper obtained in the step (a) and 5 kg.
The pressure-sensitive adhesive tape was pressure-bonded at a pressure of / cm ² and transferred to produce a double-sided adhesive tape. The total thickness of the obtained double-sided pressure-sensitive adhesive tape was 190 μm.

Example 2 (a) Preparation of resin-impregnated Japanese paper Rubber latex (manufactured by Japan Synthetic Rubber Co., Ltd., trade name: 061)
A Japanese paper similar to the Japanese paper used in the step (a) of Example 1 was dipped in the liquid having a solid content of 48% by weight of 9) for 30 seconds, then pulled up and dried at 100 ° C. for 5 minutes to obtain a resin-impregnated Japanese paper. It was The amount of rubber-based resin impregnated was 20 g / m ² . (B) Preparation of pressure-sensitive adhesive layer with release sheet Release sheet (thickness 120 μm, manufactured by Fujimori Industry Co., Ltd., product name:
SYA) rubber adhesive (made by Rikidyne, trade name: G
A 35 wt% toluene solution of R-1035) was applied so that the thickness after drying would be 65 μm, and dried at 100 ° C. for 5 minutes to obtain a pressure-sensitive adhesive layer with a release sheet. (C) Production of double-sided pressure-sensitive adhesive tape The pressure-sensitive adhesive layer with the release sheet obtained in the step (b) is laminated on both sides of the resin-impregnated Japanese paper obtained in the step (a) and 5 kg.
The pressure-sensitive adhesive tape was pressure-bonded at a pressure of / cm ² and transferred to produce a double-sided pressure-sensitive adhesive tape. The total thickness of the obtained double-sided pressure-sensitive adhesive tape was 190 μm.

[0024] 45% by weight of ethyl acetate solution of an acrylic pressure-sensitive adhesive similar to the acrylic pressure-sensitive adhesive used in Comparative Example 1 Example 1 step (b), similar to the paper used in the step (a) of Example 1 30 Japanese paper
After soaking for 2 seconds, pulling up, the total thickness after drying is 190 μm
After passing through a roll so that it becomes, it was dried at 100 ° C. for 5 minutes to obtain a double-sided adhesive tape.

Comparative Example 2 Example 1 was added to a 35% by weight toluene solution of a rubber-based adhesive similar to the rubber-based adhesive used in the step (b) of Example 2.
After dipping a Japanese paper similar to the one used in step (a) for 30 seconds, pulling it up, passing it through a roll so that the total thickness after drying is 190 μm, and then drying at 100 ° C. for 5 minutes, a double-sided adhesive tape Got

Comparative Example 3 In the step (a) of Example 1, the Japanese paper was not impregnated with the acrylic resin, and in the step (c) of Example 1,
Other than using Japanese paper not impregnated with acrylic resin,
A double-sided pressure-sensitive adhesive tape was obtained in the same manner as in Example 1. The total thickness of the obtained double-sided pressure-sensitive adhesive tape was 190 μm.

Comparative Example 4 In the step (a) of Example 2, the Japanese paper was not impregnated with the rubber latex, and in the step (c) of Example 2, the Japanese paper not impregnated with the rubber latex was used. A double-sided adhesive tape was obtained in the same manner as in Example 2 except for the above.
The total thickness of the obtained double-sided pressure-sensitive adhesive tape was 190 μm.

Comparative Example 5 The pressure-sensitive adhesive layer with the release sheet obtained in the step (b) of Example 1 was laminated on both sides of the resin-impregnated Japanese paper obtained in the step (a) of Example 2, and 5 kg / cm. ^A double-sided pressure-sensitive adhesive tape was manufactured by pressure-bonding with ² and transferring. The total thickness of the obtained double-sided pressure-sensitive adhesive tape was 190 μm.

Performance evaluation of double-sided pressure-sensitive adhesive tape The double-sided pressure-sensitive adhesive tapes of Examples 1 and 2 and Comparative Examples 1 to 5 were evaluated as follows, and the evaluation results are shown in Table 1 together with the method for producing the double-sided pressure-sensitive adhesive tape. Light transmittance The light transmittance of the double-sided pressure-sensitive adhesive tape was measured with a haze meter. This test was carried out in order to check the impregnation property of the Japanese paper with the resin, and if the impregnation with the resin is good, the light transmittance will be high. Removability test Adhesive aluminum foil (thickness: 0.3 mm) is bonded to both sides of the double-sided adhesive tape, stored at 80 ° C. for 100 hours, and then subjected to T-type peeling.
The state of the tape left on the aluminum foil on both sides was examined according to the following evaluation criteria. Evaluation Criteria ◯: The tape was tacky. Δ: Peeled at the interface between the pressure-sensitive adhesive layer and the resin-impregnated Japanese paper. X: The tape was not tacky. That is,
This means that the torn surface is between the layers of Japanese paper, indicating that the resin is not impregnated.

[0030]

[Table 1]

Example 3 (a) Preparation of resin-impregnated Japanese paper Acrylic resin (manufactured by Japan Synthetic Rubber Co., Ltd., trade name: AE11)
6) 40% by weight ethyl acetate solution was dipped in creped Japanese paper (basis weight: 50 g / m ² , thickness: 70 μm, product name: CP base paper, manufactured by Daifuku Paper Manufacturing Co., Ltd.) for 30 seconds, then pulled up and raised to 100 ° C. And dried for 5 minutes to obtain a resin-impregnated crepe-processed Japanese paper. The amount of acrylic resin impregnated is 20g / m
^{Was 2} . (B) Preparation of pressure-sensitive adhesive layer with release sheet A pressure-sensitive adhesive layer with release sheet was obtained in the same manner as in step (b) of Example 1. (C) Production of double-sided pressure-sensitive adhesive tape The pressure-sensitive adhesive layer with the release sheet obtained in the step (b) is laminated on both sides of the resin-impregnated crepe-processed Japanese paper obtained in the step (a), and pressure-bonded at 5 kg / cm ^2. And transferred to produce a double-sided adhesive tape. The total thickness of the obtained double-sided adhesive tape is 19
It was 0 μm.

Comparative Example 6 A double-sided pressure-sensitive adhesive tape was manufactured in exactly the same manner as in Example 1.

Performance evaluation of double-sided pressure-sensitive adhesive tapes The double-sided pressure-sensitive adhesive tapes of Example 3 and Comparative Example 6 were subjected to a re-peelability test in the same manner as the above-mentioned method, and a tape breaking test was further conducted by the following method to evaluate the results. Is shown in Table 2 together with the method for producing the double-sided adhesive tape. Tape breakage test method Adhesive aluminum foil (thickness 0.3 mm) was bonded to one side of double-sided adhesive tape, stored at 80 ° C for 100 hours, then peeled off at a speed of about 10 m / min, holding the tape end, and observing the tape breakage. did. Evaluation Criteria ◯: No tape breakage occurred. X: Tape breakage occurred.

[0034]

[Table 2]

Example 4 (a) Preparation of pressure-sensitive adhesive layer with release sheet Example 1 except that an ethyl acetate solution of the same pressure-sensitive adhesive as used in Example 1 was applied so that the thickness after drying was 75 μm. The same thing as the one adjusted in was used. (B) Production of double-sided pressure-sensitive adhesive tape The double-sided pressure-sensitive adhesive tape was obtained by laminating the pressure-sensitive adhesive layer with the release sheet on both sides of the same Japanese paper as used in Example 1 and transferring by pressure bonding with a laminating roll at 80 ° C. Manufactured. The total thickness of the obtained double-sided pressure-sensitive adhesive tape was 170 μm.

Example 5 Example 4 except that the temperature of the laminating roll was 90 ° C.
A double-sided pressure-sensitive adhesive tape was produced in the same manner as in. The total thickness of the obtained double-sided pressure-sensitive adhesive tape was 170 μm.

Comparative Example 7 The same Japanese paper as used in Example 1 was dipped in an ethyl acetate solution of the same adhesive as used in Example 1 for 30 seconds and then pulled up to a total thickness of 170 μm after drying. To pass through a roll and dried at 100 ° C. for 5 minutes to obtain a double-sided adhesive tape.

Comparative Example 8 Example 4 except that the temperature of the laminating roll was 30 ° C.
A double-sided pressure-sensitive adhesive tape was produced in the same manner as in.

Comparative Example 9 Example 4 except that the temperature of the laminating roll was 70.degree.
A double-sided pressure-sensitive adhesive tape was produced in the same manner as in. The total thickness of the obtained double-sided pressure-sensitive adhesive tape was 170 μm.

Performance evaluation of double-sided adhesive tape The double-sided adhesive tapes of Examples 4 and 5 and Comparative Examples 7 to 9 were evaluated in the same manner as in Example 1, and the evaluation results are shown in Table 3 together with the method for producing the double-sided adhesive tape. It was However, the evaluation criteria of the removability test are as follows. Evaluation Criteria ◯: The tape was tacky. X: The tape was not tacky. That is,
This means that the torn surface is between the layers of Japanese paper, indicating that the resin is not impregnated.

[0041]

[Table 3]

As is clear from Table 3, in Examples 4 and 5, Japanese paper was well impregnated with the adhesive even when transferred at high speed.
Therefore, even if peeled from the adherend, the layer of Washi is not destroyed. However, in Comparative Example 7, the pressure-sensitive adhesive impregnation property is good, but the coating speed by dipping is slow and the productivity is very poor.
In Comparative Examples 8 and 9, since the laminating temperature was low, the impregnating property of the pressure-sensitive adhesive was poor, and the layer destruction of Japanese paper occurred.

[0043]

The structure of the method for producing the double-sided adhesive tape of the first invention is as described above. Since the Japanese paper is impregnated with the resin in advance, high-speed coating of the adhesive by the transfer method is possible, It is a method for producing a double-sided pressure-sensitive adhesive tape using Washi as a support, which has high properties and is suitable for re-peeling.

The construction of the method for producing the double-sided pressure-sensitive adhesive tape of the second invention is as described above. Since the Japanese paper is impregnated with the resin in advance, high-speed coating of the pressure-sensitive adhesive by the transfer method is possible and the productivity is improved. This is a method for producing a double-sided pressure-sensitive adhesive tape using Washi as a support, which is high and suitable for re-peeling. Furthermore, since the crepe-processed Japanese paper is used, the double-sided pressure-sensitive adhesive tape which is less likely to cause tape breakage can be produced because the tape stretches and the stress is dispersed even if it is pulled at a high speed during re-peeling.
Therefore, the tape obtained by the method of the second invention can be used without particular consideration of the peeling speed, and is particularly easy to use.

The structure of the method for producing the double-sided pressure-sensitive adhesive tape of the third invention is as described above, and since the pressure-sensitive adhesive layer is transferred to Japanese paper at a temperature of 80 ° C., high-speed coating of the pressure-sensitive adhesive is possible. It is a manufacturing method with excellent productivity.
Further, the obtained double-sided pressure-sensitive adhesive tape is excellent in practicability since the layer of Washi paper is not destroyed even when it is peeled from the adherend.

[Brief description of drawings]

FIG. 1 is an explanatory diagram for explaining an application in which removability is required.

[Explanation of symbols]

 1 Recycled adherend 2 Double-sided adhesive tape 3 Recycled adherend

Claims (3)

[Claims] 1. A method for producing a double-sided pressure-sensitive adhesive tape, comprising forming a pressure-sensitive adhesive layer made of the same type of resin as the resin by a transfer method on both sides of a Japanese paper impregnated with the resin. 2. The method for producing a double-sided adhesive tape according to claim 1, wherein the Japanese paper is creped. 3. 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 Japanese paper by a transfer method, wherein the transfer is performed under a temperature condition of 80 ° C. or higher.