JPH108004A - Production of double sided adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production process for a double sided adhesive tape using Japanese paper as a substrate film in which a release paper and the Japanese paper are prevented from being wrinkled during the production of the half product of the objective double sided adhesive tape thereby enabling the repeated use of the release paper. SOLUTION: This double sided adhesive tape is produced by laminating a sheet of Japanese paper 1 on a release paper 2, feeding the laminate 4 to a coater 3 having a coating roller and the base roller to apply an adhesive 33 to the surface of the Japanese paper, as the laminate 4 is passed through so that the release paper 2 may contact with the base roller, peeling off the release paper 2 from the Japanese paper 1, allowing a release roller 34 set between the peeled-off release paper 2 and the Japanese paper 1 to hold the released paper on its surface to pass through, laminating new Japanese paper 1 sheet on the used release paper 2 again and drying the adhesive 33. The surface of the release roller 34 is made of a cushioning material with a 50% compression strength of 1.0-3.0kg/cm<2> and a thickness of 2.5-4.0mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a double-sided pressure-sensitive adhesive tape.

[0002]

2. Description of the Related Art Double-sided pressure-sensitive adhesive tapes based on Japanese paper have high substrate strengths, and therefore are used as adhesive tapes for packaging, medical use, splicing and other industrial uses, especially for fixing plastic members of OA equipment and for metal. It is widely used for fixing parts, fixing products that require re-peeling, and the like.

However, in the method for producing a double-sided pressure-sensitive adhesive tape using Japanese paper as a base material, the Japanese paper base material disperses fibrous materials such as mitsumata, kozo, gangan, etc. Since it is only adhered, the gap is rich, and in the direct coating method using a normal coating roll, the adhesive applied through the gap of the Japanese paper contaminates the base roll of the coating device. .

A transfer method of laminating a pressure-sensitive adhesive layer separately formed on release paper on Japanese paper as a base material and transferring the pressure-sensitive adhesive layer onto the Japanese paper has also been used. As a result, there are many irregularities and voids on the surface, the contact area ratio with the pressure-sensitive adhesive layer to be transferred is low, and the anchoring property is poor. To improve the anchoring properties of the adhesive, the surface of Japanese paper is treated with a primer, or the primer is impregnated in the paper. Has not been reached.

[0005] Furthermore, a dipping method of directly dipping Japanese paper into an adhesive, applying the dried paper, and drying the coated paper to produce a double-sided adhesive tape at a time is also used, but the resulting double-sided adhesive tape has a good anchoring property of the adhesive. Although the product itself is excellent, it has a problem that the productivity is low because it is a thick film because it is applied all at once and drying takes time.

[0006] In order to sufficiently impregnate the pressure-sensitive adhesive into the Japanese paper, the pressure-sensitive adhesive solution is applied to the surface of the Japanese paper while drying the Japanese paper on the first release paper, and then conveyed. The method of laminating the pressure-sensitive adhesive layer formed on another release paper surface on the double-sided pressure-sensitive adhesive tape semi-finished product obtained by removing the first release paper after laminating the pattern paper, the adhesive on the Japanese paper is sufficient. Manufacture of impregnated double-sided pressure-sensitive adhesive tapes became possible (public technical bulletin issued by the Hatsumei Kyokai, official technology number 95-5970)
No.).

[0007] However, there is no escape space for the air sandwiched between the first release paper and the washi paper, that is, the air in the washi paper and the air entrapped during the application of the adhesive, and is trapped at the interface between the release paper and the washi paper. Therefore, when the first release paper is bonded to another release paper, wrinkles due to bubbles are generated, and there is a problem that the release paper cannot be reused.

Therefore, after applying the pressure-sensitive adhesive solution while conveying the Japanese paper on the first release paper, the release paper is once peeled off from the Japanese paper via a peeling roll between the release paper and the Japanese paper, and then again. A method of bonding and transferring to a drying oven was developed.

In the method for manufacturing a double-sided pressure-sensitive adhesive tape disclosed in the above-mentioned publication, the improvement of the anchoring property of the pressure-sensitive adhesive and the removal of air bubbles generated between the pressure-sensitive adhesive layer and the release paper at the time of manufacturing have been discussed. I saw some improvement. However, the pressure-sensitive adhesive solution that has passed through the Japanese paper is present as a very thin film on the release paper surface, and this is accumulated in a non-uniform state on the release roll surface. The accumulated pressure-sensitive adhesive peels off the pressure-sensitive adhesive of the release paper partially in the width direction of the roll to form a streak-free portion without the pressure-sensitive adhesive. Therefore, a new problem arises in that a difference in thickness occurs from a portion where the pressure-sensitive adhesive is not removed and bubbles are trapped in this portion.

As a result, when the pressure-sensitive adhesive is applied, the paper is impregnated with the pressure-sensitive adhesive into the Japanese paper, and the air bubbles caught in the release paper lose their escape, and the air bubbles are generated at the interface between the first release paper and the Japanese paper. Generate. In the step of drying this adhesive and transferring it to the second release paper, wrinkles due to the air bubbles occur in the first release paper or Japanese paper, and the problem remains that the first release paper cannot be reused.

[0011]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and provides a method for producing a pressure-sensitive adhesive tape using Japanese paper as a base film. It is an object of the present invention to provide a method for producing a double-sided pressure-sensitive adhesive tape that can prevent wrinkles from occurring and that can repeatedly use release paper.

[0012]

According to the present invention, a laminate in which Japanese paper is superimposed on release paper is supplied to a coating apparatus comprising an application roll and a base roll, and the release paper is brought into contact with the base roll and passed through the laminate. After applying the adhesive to the surface of the washi paper, the release paper was peeled off from the washi paper, the release paper was passed through the release roll surface provided between the released release paper and the washi paper, and then released again from the washi paper. A method for producing a double-sided pressure-sensitive adhesive tape, comprising laminating a pattern paper and drying a pressure-sensitive adhesive, wherein the release roll surface has a 50% compressive strength of 1.0 to 3.0 kg / cm ² and a thickness of 2.5 to 2.5 kg / cm ^2. It is characterized by being made of a cushion material of 4.0 mm.

The apparatus for applying the pressure-sensitive adhesive is not particularly limited as long as it is a two-roll coater including an application roll and a base roll forming a pair with the adhesive roll. For example, a comma coater, a direct gravure roll coater, a gravure offset Roll coater, natural roll coater, reverse roll coater, squeeze roll coater, kiss roll coater and the like can be mentioned.

The Japanese paper used in the present invention has a basis weight of 30 to 80 g.
/ M ² and a thickness of 50 to 100 μm are preferred.

The pressure-sensitive adhesive may be any one of a water-based pressure-sensitive adhesive and an organic solvent-based pressure-sensitive adhesive, and examples thereof include a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, and an emulsion-type pressure-sensitive adhesive. In particular, an acrylic pressure-sensitive adhesive is preferable because it has a smaller molecular weight than a rubber-based pressure-sensitive adhesive and is easily impregnated into Japanese paper. In order to make a double-sided adhesive tape, it is preferable to increase the amount of the adhesive applied at the time of the first adhesive application and to sufficiently impregnate the Japanese paper so that the strength of the Japanese paper can be improved.
The coating amount is preferably 50 g / m ² or more in terms of the solid content of the pressure-sensitive adhesive.

The release paper is not particularly limited. For example, high-quality paper, glassine paper, kraft paper or the like or a polyester film on which at least one surface of a release film has been release-treated can be used. When release paper having one side subjected to release processing is used, Japanese paper is to be superposed on the release processing surface.

In the present invention, a laminate in which Japanese paper is superimposed on release paper is supplied to a coating device using the release paper as a base roll side, and an adhesive is applied to the surface of the Japanese paper. Immediately after the applied laminate separates from the base roll, the release paper is peeled off from the washi paper, guided outside the transport direction of the washi paper, and passed through a release roll disposed between the washi and the release paper. The peeling roll is disposed so as to contact only the release paper without contacting the Japanese paper, and to feed the release paper toward the Japanese paper again. After passing through the peeling roll, the release paper is bonded again to the Japanese paper, and then sent to a drying device for the adhesive to be dried. The purpose of once separating the release paper from the Japanese paper is to release air bubbles interposed between the interface between the Japanese paper and the release paper.

Since the peeling roll rotates in contact with the laminating surface of the release paper that has been laminated and peeled off from the washi paper coated with the adhesive,
A small amount of the adhesive adhered to the release paper adheres to the release roll. When a normal roll having a metal surface is used as the peeling roll, the pressure-sensitive adhesive gradually accumulates in a portion where the pressure-sensitive adhesive adheres to the peeling roll. The adhesion and accumulation of the pressure-sensitive adhesive is non-uniform on the roll surface, and the pressure-sensitive adhesive on the surface of the release paper is taken in a portion where the thickness of the pressure-sensitive adhesive is large, so that the pressure-sensitive adhesive becomes thicker. However, the thinner part of the adhered adhesive gradually loses contact with the surface of the release paper, and the amount of the adhered adhesive becomes uneven on the surface of the release paper after passing through the release roll.

When laminating again on the Japanese paper in this state, it is separated from the Japanese paper.
Air is entrapped between the paper and the paper pattern, and
The air bubbles accumulate before the laminating roll,
Release paper and Japanese paper when crushed by
You. Therefore, in the present invention, the roll surface has a 50% compressive strength.
1.0 to 3.0 kg / cm ^TwoFrom cushioning material
Use The cushion material is a normal metal roll surface
It may be used by winding and bonding.

The cushioning material has a compressive strength of 50% of 1.0 to 3.0 kg / cm ² and a thickness of 2.5 to 3.0 kg / cm ^2.
The material is not limited as long as it is 4.0 mm, and examples thereof include foams such as polyethylene and polyurethane. When the thickness and the compressive strength are in the above ranges, the surface contact state between the release paper surface and the release roll can always be made uniform and constant, and the distribution of the pressure-sensitive adhesive on the release paper surface is averaged.

(Function) An adhesive is applied to the Japanese paper surface of a laminate obtained by laminating Japanese paper on release paper, and after the laminate passes through the base roll, the release paper is once separated from the Japanese paper. Bubbles interposed at the interface with are released. The peeled release paper has a compressive strength of 1.0 to 3.0 kg / 50% on the surface.
cm ² and a release roll made of a cushion material having a thickness of 2.5 to 4.0 mm, so that the surface contact state between the release paper surface and the release roll can always be uniform and constant. The distribution of the adhesive on the paper pattern surface is averaged,
No air bubbles are generated between the Japanese paper and the release paper, and no wrinkles are generated on the release paper or the Japanese paper.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. The materials used are as follows. Release paper : high-quality paper on both sides of which polyethylene is laminated with a thickness of 20 μm, and which is subjected to a release treatment by applying silicone so that the release force is 50 g / mm. Washi: DP base paper (Daifuku Paper Co., Ltd., thickness 65 μm, basis weight 3)
5 g / m ² ) Adhesive: Acrylic adhesive (trade name “S” manufactured by Soken Chemical Co., Ltd.)
K-1717 "(solid content 45%), 100 parts by weight of a curing agent (trade name" Coronate L55 "manufactured by Nippon Polyurethane Co., Ltd.)
E ") One part by weight is added.

(Embodiment 1) FIG. 1 is an explanatory view for explaining an embodiment of the method for producing a pressure-sensitive adhesive tape of the present invention, and FIG.
It is an enlarged view of the A section. Reference numeral 3 denotes a coating device, which includes a comma roll 31 and a base roll 32. The tension of each of the Japanese paper 1 and the first release paper 2 fed from the roll-shaped winding body is adjusted, and the laminate 4 obtained by stacking the Japanese paper 1 on the release processing surface of the first release paper 2 is subjected to the first release. Pattern 2 is base roll 3
2 and was supplied to the coating device 3.

The adhesive 4 is dried by the comma coater 31 in the coating device 3 so that the thickness of the laminate 4 becomes 80 g / m ² after drying.
Was coated on one side of Japanese paper. When the laminate 4 has left the base roll 32, only the first release paper 2 is peeled off toward the base roll 32, and a polyethylene foam (manufactured by Sekisui Chemical Co., Ltd., trade name "Softlon S # 3003", 50% The peeling surface of the first release paper 2 is passed through a peeling roll 34 wound with a compressive strength of 1.0 kg / cm ² and a thickness of 3 mm), guided to a guide roll 35, where it is laminated with the Japanese paper 1 again. Then, it was transferred to a drying device 5 set in five temperature zones as shown in Table 1.

The second release paper 6 having a larger peeling force than the first release paper 2 is fed out, and the Japanese paper surface of the laminate 4 whose adhesive has been dried by the drying device 5 is overlaid on the second release paper 6, and the pinch roll 9 , 91, the Japanese paper 1 was transferred to the second release paper 6, and the first release paper 2 was peeled off. The Japanese paper 1 transferred to the second release paper 6 is wound together with the second release paper 6 to obtain an adhesive tape product. When a double-sided pressure-sensitive adhesive tape is manufactured using Japanese paper wound with the second release paper 6, this state is the semi-finished product 61.

[0026]

[Table 1]

In order to form a double-sided adhesive tape, as shown in FIG. 3, a third release paper 8 is fed out, an adhesive is applied to the third release paper 8 by the adhesive application device 3 and dried by the drying device 5. Then, the semi-finished product 61 is fed out, the adhesive layer is transferred to the surface of the Japanese paper to form a double-sided adhesive tape, and then the second release paper 6 is peeled off to form the third release paper 8. At the same time, the double-sided adhesive tape 7 was wound up.

(Example 2) Using the same manufacturing apparatus as in Example 1, a polyethylene foam (manufactured by Sekisui Chemical Co., Ltd., trade name "Softlon S # 1003", thickness 3 mm, 50% compressive strength 1.7 kg) / Cm ² ), except that a double-sided pressure-sensitive adhesive tape was obtained in the same manner as in Example 1.

(Comparative Example 1) Polyethylene foam (manufactured by Sekisui Chemical Co., Ltd., trade name "Softlon S # 1003", 1 mm thick sliced product, 50% compressive strength of 1.3 kg / c)
except using m ²⁾ in the same manner as in Example 1 to obtain a double-sided adhesive tape.

Comparative Example 2 A double-sided pressure-sensitive adhesive tape was obtained in the same manner as in Comparative Example 1, except that a polyethylene foam having a thickness of 2 mm was used.

(Comparative Example 3) Polyethylene foam (manufactured by Sekisui Chemical Co., Ltd., trade name "Softlon F # 30025", thickness 2.5 mm, 50% compressive strength 0.9 kg / cm ² )
A double-sided pressure-sensitive adhesive tape was obtained in the same manner as in Example 1 except for using.

Comparative Example 4 A double-sided pressure-sensitive adhesive tape was obtained in the same manner as in Example 1 except that a polyethylene foam having a thickness of 3 mm and a 50% compressive strength of 5.7 kg / cm ² was used.

(Comparative Example 5) The thickness of the polyethylene foam was
4.5mm, 50% compressive strength is 1.5kg / cm ^TwoNomo
Double-sided adhesive tape in the same manner as in Example 1 except that
I got

The state of wrinkling of the double-sided pressure-sensitive adhesive tapes obtained in Examples 1 and 2 and Comparative Examples 1 to 5 was visually observed. Table 2 shows the results.

[0035]

[Table 2]

As is clear from Table 2, wrinkles did not occur at all in the double-sided pressure-sensitive adhesive tape produced by the method of the present invention, but wrinkles occurred in all of the comparative examples.

[0037]

The method for producing a double-sided pressure-sensitive adhesive tape of the present invention has the above constitution. Immediately after the application of the pressure-sensitive adhesive, the release paper is once peeled off from the washi paper. 0.0-3.0 kg / cm ² and thickness 2.5
Since it passes through a release roll made of a cushion material of up to 4.0 mm, the surface contact state between the release paper surface and the release roll can always be uniform and constant, and the distribution of the adhesive on the release paper surface is averaged. In the process from application of the adhesive to drying, no air bubbles are generated between the Japanese paper and the release paper, and no wrinkles are generated on the release paper or the Japanese paper. Also, release paper can be used repeatedly.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of the method for producing a double-sided pressure-sensitive adhesive tape of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is an explanatory view showing an embodiment when a double-sided pressure-sensitive adhesive tape is manufactured according to the present invention.

[Explanation of symbols]

 1: Japanese paper 2: First release paper 3: Coating device 4: Laminate 5: Drying device 6: Second release paper 7: Double-sided adhesive tape 8: Third release paper 9, 91: Pinch roll 31: Comma roll 32: Base roll 33: Adhesive 34: Peeling roll 35: Guide roll 61: Semi-finished product

Claims (1)

[Claims] 1. A laminate obtained by laminating Japanese paper on release paper is supplied to an adhesive application device comprising an application roll and a base roll, and an adhesive is applied to the surface of the Japanese paper while the release paper is in contact with the base roll and passes through the laminate. After applying the release paper, the release paper is peeled off from the washi paper, the release paper is provided between the peeled release paper and the washi paper, and the release paper is passed through a release roll surface arranged so that only the release paper comes in contact with the release paper, and then again with the washi paper. A method for producing an adhesive tape, comprising laminating release paper and drying an adhesive, wherein the release roll surface has a 50% compressive strength of 1.0 to 3.0 kg / cm ^2.
A method for producing a double-sided pressure-sensitive adhesive tape, comprising a cushion material having a thickness of 2.5 to 4.0 mm.