JP2010189532A - Method for manufacturing double-sided adhesive tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-sided adhesive tape which is suited for use of rolling up with a double-sided release liner into a roll and removing an adhesive layer on back side of an adhesive layer first exposed when rewinding, and to provide a method for manufacturing the same. <P>SOLUTION: The method for manufacturing the double-sided adhesive tape comprises steps of: forming a first adhesive layer by applying a first adhesive composition to a release surface 5A of a process liner 5; forming a process liner/substrate laminate by laminating one side of a porous substrate 4 on the upper surface of the first adhesive layer; forming a second adhesive layer by applying a second adhesive composition to the other side of the substrate 4; forming a process liner/substrate/product liner laminate by laminating one side of a product liner 3 on the upper surface of the second adhesive layer; removing the process liner 5 from the laminate; bringing the other side of the product liner 3 into contact with the lower surface of the exposed first adhesive layer; and rolling up a substrate/product liner laminate in a roll so as to obtain the double-sided adhesive tape 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a double-sided pressure-sensitive adhesive tape in which a pressure-sensitive adhesive layer formed using a water-dispersed pressure-sensitive adhesive (also referred to as pressure-sensitive adhesion, hereinafter the same) agent composition is supported by a porous substrate, and a method for producing the same.

Double-sided adhesive tapes with a pressure-sensitive adhesive layer on a porous substrate such as nonwoven fabric are widely used in various industrial fields such as home appliances, automobiles, and office automation equipment as bonding means with good workability and high adhesion reliability. It's being used.
In recent years, from the viewpoint of resource saving, as for recyclable parts used in products, the products or their constituent materials are often reused (recycled) by disassembling the products after use. When reusing a part or its constituent material that has been joined to another part using a double-sided adhesive tape, usually, the joint part of the double-sided adhesive tape is first peeled off, and the part to be reused (recycled part) is used. Separate the parts. At this time, if the peeling is performed in a state where the residue of the double-sided pressure-sensitive adhesive tape is adhered to the surface of the recycling component, the efficiency of the recycling process is significantly reduced due to the operation of removing the residue from the surface of the component. Patent documents 1-3 are mentioned as technical literature about the peelability (removability) of such a double-sided adhesive tape.

JP 2006-143856 A JP 2001-152111 A JP 2000-265140 A

  So far, as a pressure-sensitive adhesive composition used for forming a pressure-sensitive adhesive layer in the production of a double-sided pressure-sensitive adhesive tape, a solvent-type composition in which a pressure-sensitive adhesive component (such as a polymer) is dissolved in an organic solvent has been the mainstream. However, in recent years, from the viewpoint of environmental considerations and reduction of the amount of volatile organic compounds (VOC) emitted from double-sided adhesive tapes, a water-dispersed type (water-based) in which an adhesive component is dispersed in water. ) Use of the pressure-sensitive adhesive composition tends to be preferred. Such conversion to a water-dispersed pressure-sensitive adhesive composition is not limited to pressure-sensitive adhesive compositions for double-sided pressure-sensitive adhesive tapes, and has been studied in various fields. Development is progressing with the aim of a water-dispersed pressure-sensitive adhesive composition that can achieve superior adhesive performance.

  As a representative example of a method for providing a pressure-sensitive adhesive layer on a porous substrate (nonwoven fabric or the like), a method in which a pressure-sensitive adhesive composition is directly applied to a substrate and dried or cured (direct coating method; hereinafter simply referred to as “direct method”). ) And a pressure-sensitive adhesive layer (typically formed by applying a pressure-sensitive adhesive composition to the surface and drying or curing it) on a peelable surface (eg, the surface of a release liner) And a method of transferring the pressure-sensitive adhesive layer onto the substrate (transfer method). In the production of double-sided pressure-sensitive adhesive tapes using a water-dispersed pressure-sensitive adhesive composition, depending on the material of the base material (for example, a nonwoven fabric mainly composed of cellulosic materials), the strength tends to decrease or wrinkles are likely to occur when wet. For this reason, a method (transfer-transfer method) in which an adhesive layer is provided by a transfer method on one side and the other side of a substrate is widely used. As another manufacturing method, there is a method in which an adhesive layer is first formed on one surface of a substrate by a transfer method, and then an adhesive layer is formed on the other surface of the substrate by a direct method (transfer-direct method). Conceivable.

The manufacturing process of the double-sided pressure-sensitive adhesive tape by the transfer-direct method will be described with reference to FIG.
A double-sided pressure-sensitive adhesive tape manufacturing apparatus 120 shown in FIG. 10 includes a first coating unit 130 and a second coating unit 140, an unwinding roll 121 that runs the release liner 103 via these coating units 130 and 140, and A winding roll 122 and a substrate roll 123 that supplies a nonwoven fabric (porous substrate) 104 to the release liner 103 from the first coating unit 130 toward the second coating unit 140 are provided. As the release liner 103, one having both surfaces configured as release surfaces, that is, a double-sided release liner is used.

The release liner 103 delivered from the unwinding roll 121 is first introduced into the first coating unit 130. The first coating unit 130 includes, in order from the upstream side, a coater 132 that applies the pressure-sensitive adhesive composition to the release liner 103 and a dryer 134 that dries the applied composition. The first pressure-sensitive adhesive layer 101 is formed on the one surface 103A of the release liner 103 by the first coating portion 130 having such a configuration (see FIG. 11).
Next, one surface 104A of the nonwoven fabric 104 fed from the substrate roll 123 is placed on the upper surface 101A of the first pressure-sensitive adhesive layer 101 formed on the release liner 103 (the outer surface when the pressure-sensitive adhesive composition is applied). Then, they are bonded together by the pressure roll 124. In this way, the first pressure-sensitive adhesive layer 101 is provided on one surface 104A of the nonwoven fabric 104 (transfer method).
The release liner 103 (see FIG. 12) on which the first pressure-sensitive adhesive layer 101 and the nonwoven fabric 104 are laminated is then introduced into the second coating part 140. The second coating unit 140 includes, in order from the upstream side, a coater 142 that directly applies the pressure-sensitive adhesive composition to the other surface 104B of the nonwoven fabric 104, and a dryer 144 that dries the applied composition. The second pressure-sensitive adhesive layer 102 is formed on the other surface 104B of the nonwoven fabric 104 by the second coating part 140 having such a configuration (direct method).
The laminate thus formed (see FIG. 13) is wound up in a roll shape so that the other surface 103B of the release liner 103 is in contact with the upper surface 102A of the second pressure-sensitive adhesive layer 102. Thereby, the double-sided adhesive tape (product) 100 of the form by which the nonwoven fabric 104 which has the adhesive layers 101 and 102 on both surfaces was wound by roll shape through the peeling liner 103 is obtained. That is, after the release liner 103 is used for forming the first pressure-sensitive adhesive layer 101, it is subsequently used as a component of a double-sided pressure-sensitive adhesive tape product (that is, as a product release liner).

  One typical operation example in the case of fixing a consumable part (a part that is not scheduled to be recycled, such as a cushioning material) to a recycling part (for example, a resin molding) using the double-sided adhesive tape 100 is as follows. . That is, as shown in FIG. 14, the end of the double-sided pressure-sensitive adhesive tape 100 wound in a roll shape is rewound (that is, pulled out from the roll), and the upper surface 102A (first application) of the second pressure-sensitive adhesive layer 102 exposed thereby. Surface) to the consumable part 12. The rewound double-sided pressure-sensitive adhesive tape 100 is cut to an appropriate length before or after pressure bonding to the consumable part 12 (FIG. 14 shows an example of cutting after pressure bonding). Next, the release liner 103 is peeled off from the double-sided pressure-sensitive adhesive tape 100 pressure-bonded to the consumable part 12, and the lower surface 101B (second bonding surface) of the first pressure-sensitive adhesive layer 101 exposed thereby is pressure-bonded to the recycling part 14 (FIG. 15). ). In this way, the consumable part 12 can be fixed to the recycling part 14 in an efficient manner.

Here, as shown in FIG. 15, when the consumable part 12 attached to the recycling part 14 is separated from the recycling part 14 using the double-sided adhesive tape 100, the double-sided adhesive tape 100 together with the consumable part 12 is used. Is peeled off from the recycling component 14 so that the residue of the double-sided adhesive tape 100 does not remain on the surface of the recycling component 14.
However, the pressure-sensitive adhesive layer formed by directly applying the pressure-sensitive adhesive composition to the porous substrate is free from bubbles (the gas contained in the porous substrate tends to escape outside) when the composition is dried. Bubbles are easily generated, and the surface state (smoothness) of the pressure-sensitive adhesive layer is easily impaired by the bubbles. For this reason, compared with the pressure-sensitive adhesive surface (surface exposed first by rewinding, here, the upper surface 102A of the second pressure-sensitive adhesive layer 102 formed by the direct method), it is pressure-bonded to the recycling component 14. The pressure-sensitive adhesive surface (the lower surface 101B of the first pressure-sensitive adhesive layer 101 provided by the transfer method) has higher smoothness, and the double-sided pressure-sensitive adhesive tape 100 adheres more firmly to the recycling component 14 than the consumable component 12. It tends to be. This is disadvantageous for the above-mentioned demand for peeling the entire double-sided adhesive tape 100 together with the consumable part 12 from the recycling part 14.

  Therefore, the present invention is a double-sided pressure-sensitive adhesive tape wound in a roll shape through a release liner, wherein the pressure-sensitive adhesive layer on the back surface of the pressure-sensitive adhesive layer that is first exposed by rewinding is re-peeled from the adherend. An object is to provide a method for producing a double-sided pressure-sensitive adhesive tape suitable for other uses (for example, the use in which the pressure-sensitive adhesive layer on the back surface is attached to a recycling part). Another object of the present invention is to provide a double-sided pressure-sensitive adhesive tape suitable for such use.

  According to the present invention, double-sided pressure-sensitive adhesive in which a pressure-sensitive adhesive layer formed from a water-dispersed pressure-sensitive adhesive composition (for example, an emulsion-type pressure-sensitive adhesive composition) is provided on one surface and the other surface of a porous substrate. A double-sided pressure-sensitive adhesive tape (adhesive tape roll) is manufactured in a roll form through a double-sided peelable product release liner (hereinafter sometimes abbreviated as “product liner”). A method is provided. The method includes applying a first pressure-sensitive adhesive composition on a release surface of a process release liner (hereinafter sometimes abbreviated as “process liner”) to form a first pressure-sensitive adhesive layer. In addition, after the first step, one of the surfaces of the substrate is bonded to the upper surface of the first pressure-sensitive adhesive layer to form a process liner / substrate laminate. Further, the method includes applying a second pressure-sensitive adhesive composition to the other surface of the base material to form a second pressure-sensitive adhesive layer. Further, the method includes bonding one surface of the release liner for product to the upper surface of the second pressure-sensitive adhesive layer to form a process liner / substrate / product liner laminate. Also, the process release liner may be removed from the process liner / substrate / product liner laminate to form a substrate / product liner laminate in which the lower surface of the first pressure-sensitive adhesive layer is exposed. Furthermore, the other surface of the release liner for product is brought into contact with the exposed lower surface of the first pressure-sensitive adhesive layer, and the substrate / product liner laminate is wound up in a roll shape.

  In the double-sided pressure-sensitive adhesive tape manufactured by such a method, the first exposed surface (first adhesive surface) when rewound becomes the lower surface of the pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer) provided by the transfer method, and its back surface The (second adhesive surface) is an adhesive layer (second adhesive layer) formed by a direct method. Therefore, this method is suitable for producing a double-sided pressure-sensitive adhesive tape in which the first sticking surface has higher smoothness than the second sticking surface. Thus, the high smoothness of the first pasting surface is advantageous in improving the adhesiveness (peeling adhesive strength, etc.) of the first pasting surface. The double-sided pressure-sensitive adhesive tape manufactured by the above method is, for example, an aspect in which the first adhesive surface is first attached to the consumable part, and then the second adhesive surface is attached to the recycling part, thereby fixing the consumable part to the recycling part. And can be used to achieve excellent recyclability. The above production method uses a water-dispersed pressure-sensitive adhesive composition, which is preferable for environmental hygiene. In addition, since a pressure-sensitive adhesive layer is formed on one surface of a base material by a transfer method, and then a pressure-sensitive adhesive layer is formed on the other surface of the base material by a direct method (that is, transfer-direct method), various base materials It can be preferably applied to the production of double-sided pressure-sensitive adhesive tapes using For example, it is suitable as a method for producing a double-sided pressure-sensitive adhesive tape using a nonwoven fabric mainly composed of a cellulose-based material (that is, a nonwoven fabric in which the content of the cellulose-based material exceeds 50% by mass) as a substrate.

  In a preferred embodiment, a composition having a lower viscosity than the first pressure-sensitive adhesive composition is used as the second pressure-sensitive adhesive composition (that is, a pressure-sensitive adhesive composition that is directly applied to a substrate). By using such a low-viscosity pressure-sensitive adhesive composition, the penetration of the composition into the base material is improved, so that a second pressure-sensitive adhesive layer that is well impregnated with the base material can be formed. . As a result, when the second pressure-sensitive adhesive layer is peeled off again from the adherend, a phenomenon in which a part of the pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer remains on the adherend surface (adhesive residue) is further prevented. can do. As the first and second pressure-sensitive adhesive compositions, an emulsion-type pressure-sensitive adhesive composition mainly composed of the same or different acrylic polymer (for example, a pressure-sensitive adhesive composition obtained by emulsion polymerization) is preferably employed. Can do.

  According to the present invention, the pressure-sensitive adhesive layer formed from the water-dispersed pressure-sensitive adhesive composition is provided on one side and the other side of the porous substrate, and the double-sided release product release liner is provided. A double-sided adhesive tape wound in a roll is provided. Among the above-mentioned pressure-sensitive adhesive layers, the first pressure-sensitive adhesive layer provided on one surface of the base material is formed by laminating a pressure-sensitive adhesive layer previously formed on the release surface on the base material (that is, by a transfer method). It is provided. Further, the second pressure-sensitive adhesive layer provided on the other surface of the base material is provided by directly applying the pressure-sensitive adhesive composition to the base material (that is, by a direct method). The double-sided pressure-sensitive adhesive tape is configured such that the first pressure-sensitive adhesive layer is exposed by rewinding from the state wound in the roll shape.

  The double-sided pressure-sensitive adhesive tape having such a structure (which may be produced by any of the methods disclosed herein) has a smoothness on the back surface (first sticking surface) that is exposed first when it is rewound. It may be higher than the smoothness of the (second pasting surface). Therefore, by first attaching the first pasting surface to a consumable part (parts that are not scheduled to be recycled) and then pasting the second pasting surface to a recycling part (parts that are expected to be recycled) It can be preferably used in a manner of fixing a part and can realize excellent recyclability. Any one of the double-sided pressure-sensitive adhesive tapes disclosed herein is suitable for applications in which the pressure-sensitive adhesive tape (typically, the second sticking surface of the pressure-sensitive adhesive tape) is attached to a recycling part. For example, it is suitable for applications in which consumable parts are fixed to recycling parts.

The typical explanatory view which illustrates the double-sided adhesive tape manufacturing method concerning one embodiment. II-II sectional view taken on the line of FIG. III-III sectional view taken on the line of FIG. IV-IV sectional view taken on the line of FIG. The VV sectional view taken on the line of FIG. The VI-VI sectional view taken on the line of FIG. The typical sectional view which illustrates the use mode of the double-sided adhesive tape concerning one embodiment. The typical sectional view which illustrates the use mode of the double-sided adhesive tape concerning one embodiment. The typical sectional view which illustrates the use mode of the double-sided adhesive tape concerning one embodiment. Typical explanatory drawing which shows the conventional double-sided adhesive sheet manufacturing method. XI-XI sectional view taken on the line of FIG. XII-XII sectional view taken on the line of FIG. XIII-XIII sectional view taken on the line of FIG. Typical sectional drawing which illustrates the usage condition of the conventional double-sided adhesive tape. Typical sectional drawing which illustrates the usage condition of the conventional double-sided adhesive tape.

  Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field.

  The double-sided pressure-sensitive adhesive tape according to the present invention may have, for example, a cross-sectional structure schematically shown in FIG. 7 (showing a state where one end of the roll is unwound). This double-sided pressure-sensitive adhesive tape 10 has a porous substrate 4 having pressure-sensitive adhesive layers 1 and 2 on both sides, wound in a roll shape through a product liner 3 having both sides as release surfaces (surfaces having peelability). Have different forms. As the porous substrate 4, for example, a nonwoven fabric (cellulosic nonwoven fabric) mainly composed of a cellulose material is preferably used. The first pressure-sensitive adhesive layer 1 on one side of the nonwoven fabric 4 is provided by the transfer method, and the second pressure-sensitive adhesive layer 2 on the other side is provided by the direct method. The double-sided pressure-sensitive adhesive tape 10 is configured such that the surface (first sticking surface) 1B of the first pressure-sensitive adhesive layer 1 is exposed by rewinding from the roll shape.

  A preferred embodiment for producing the double-sided pressure-sensitive adhesive tape 10 having such a configuration will be described with reference to the drawings. FIG. 1 is a schematic view illustrating a schematic configuration of a double-sided pressure-sensitive adhesive tape manufacturing apparatus 20 that can be preferably used for manufacturing the double-sided pressure-sensitive adhesive tape 10. The manufacturing apparatus 20 includes a first coating unit 30 and a second coating unit 40, feed rolls 21 and 22 that run the process liner 5 through the coating units 30 and 40, and a first coating. A substrate roll 23 that is disposed between the portion 30 and the second coating portion 40 and feeds the nonwoven fabric 4 as a porous substrate, and is disposed on the downstream side of the second coating portion 40 and feeds the product liner 3. A product liner supply roll 25 and a take-up roll 27 that is disposed on the downstream side of the product liner and winds the double-sided pressure-sensitive adhesive tape 10 into a roll shape are provided. The process liner 5 is removed before the winding roll 27 (that is, in the middle of the manufacturing process) and is not included in the components of the double-sided pressure-sensitive adhesive tape 10.

  The process liner 5 sent to the right from the left end in FIG. 1 is first introduced into the first coating unit 30. The first coating unit 30 dries the coater 32 for applying the water-dispersed pressure-sensitive adhesive composition to one surface (peeling surface) 5A of the process liner 5 and the applied composition in order from the upstream side. A dryer 34. As shown in FIG. 2 (sectional view taken along the line II-II in FIG. 1), the first pressure-sensitive adhesive layer 1 is formed on the process liner 5 by the first coating part 30 having such a configuration (step S10).

  Next, the one surface 4A of the nonwoven fabric 4 fed from the base roll 23 is used as the upper surface 1A of the first pressure-sensitive adhesive layer 1 formed on the release surface 5A of the process liner 5 (at the time of application of the pressure-sensitive adhesive composition). A process liner / nonwoven fabric (base material) laminate is formed on the outer side surface by, for example, the pressure roll 24 (step S20). Thereby, as shown in FIG. 3 (III-III line sectional drawing of FIG. 1), the 1st adhesive layer 1 is provided in one surface 4A of the nonwoven fabric 4 (transfer method). The lower surface 1B of the first pressure-sensitive adhesive layer 1 is continuously supported (backed) by the process liner 5.

  The process liner / nonwoven fabric (base material) laminate shown in FIG. 3 is then introduced into the second coating part 40. The second coating unit 40 includes, in order from the upstream side, a coater 42 that directly applies the water-dispersed pressure-sensitive adhesive composition to the other surface 4B of the nonwoven fabric 4, and a dryer 44 that dries the applied composition. Prepare. As shown in FIG. 4 (sectional view taken along the line IV-IV in FIG. 1), the second pressure-sensitive adhesive layer 2 is formed on the other surface 4B of the nonwoven fabric 4 by the second coating portion 40 having such a configuration (direct method; Step S30). Here, when the water-dispersed pressure-sensitive adhesive composition is directly applied to the other surface 4B of the non-woven fabric 4, the non-woven fabric 4 is provided with the first pressure-sensitive adhesive layer 1 on its one surface 4A by a transfer method, and The lower surface 1B of one pressure-sensitive adhesive layer is supported by the process liner 5. As a result, the phenomenon that the nonwoven fabric 4 is broken or wrinkled is prevented.

  Next, one surface 3 </ b> A of the product liner 3 sent out from the product liner supply roll 25 is bonded to the upper surface 2 </ b> A of the second pressure-sensitive adhesive layer 2 by, for example, a pressure roll 26. Thereby, the process liner / base material / product liner laminate shown in FIG. 5 (cross-sectional view taken along the line VV in FIG. 1) is formed (step S40).

  Thereafter, the process liner 5 is removed from the process liner / substrate / product liner laminate. Thereby, as shown in FIG. 6 (sectional view taken along line VI-VI in FIG. 1), a base material / product liner laminate in which the lower surface 1B of the first pressure-sensitive adhesive layer 1 is exposed is formed (step S50). And the said base material / product liner laminated body is wound up by the winding roll 27 so that the other surface 3B of the product liner 3 may contact | abut on the lower surface 1B of the 1st adhesive layer 1 (step S60). Prior to the winding, the substrate / product liner laminate may be slit to a predetermined width as necessary. In this way, a roll-shaped double-sided pressure-sensitive adhesive tape (adhesive tape roll) 10 is obtained.

  A double-sided pressure-sensitive adhesive tape 10 having such a structure (which may be a double-sided pressure-sensitive adhesive tape manufactured by any of the methods disclosed herein. The same shall apply hereinafter) is used for a consumable part (for example, a resin molded body). The operation of fixing an unplanned part, for example, a cushioning material, can be preferably performed as follows, for example. That is, as shown in FIG. 7, the end of the double-sided pressure-sensitive adhesive tape 10 wound in a roll shape is rewound (step S100), and the lower surface 1B (first sticking surface) of the first pressure-sensitive adhesive layer 1 exposed thereby is removed. Crimp to the consumable part 12 (step S110). The rewound double-sided pressure-sensitive adhesive tape 10 is cut to an appropriate length before or after pressure bonding to the consumable part 12 (step S120). FIG. 7 shows an example of cutting after pressure bonding. Next, the product liner 3 is peeled off from the double-sided pressure-sensitive adhesive tape 10 pressure-bonded to the consumable part 12 (step 130), and the upper surface 2A (second adhesive surface) of the second pressure-sensitive adhesive layer 2 exposed thereby is shown in FIG. Crimping is performed on the recycling component 14 (step S140). In this way, the consumable part 12 can be fixed to the recycling part 14 in an efficient manner.

  In the usage mode (see FIGS. 7 and 8), the double-sided pressure-sensitive adhesive tape 10 is opposite to the usage modes shown in FIGS. Thus, the second adhesive surface on the recycling component 14 side is configured to be the second pressure-sensitive adhesive layer 2 by the direct method. As described above, the pressure-sensitive adhesive layer formed by the direct method tends to have lower surface smoothness than the pressure-sensitive adhesive layer formed by the transfer method, and thus the double-sided pressure-sensitive adhesive tape 10 is consumed more than the recycling component 14 side. It has a configuration suitable for enhancing the adhesion to the component 12 side. Therefore, according to the double-sided pressure-sensitive adhesive tape 10 having the configuration shown in FIG. 7, compared to the double-sided pressure-sensitive adhesive tape 100 having the configuration shown in FIG. 14 (the first sticking surface is formed by the direct method and the second sticking surface is formed by the transfer method). Thus, better removability can be realized.

  1 and 7 show an example of winding the substrate / product liner laminate with the first pressure-sensitive adhesive layer 1 on the inside, but the above-mentioned laminate is wound with the first pressure-sensitive adhesive layer 1 on the outside. You may take it. Also in this case, the first exposed surface (first applied surface) when rewinding becomes the first adhesive layer 1 by the transfer method, and then the exposed surface (second applied surface, i.e., first applied surface) by peeling off the product liner. A roll-shaped double-sided pressure-sensitive adhesive tape configured such that the back surface of one sticking surface becomes the second pressure-sensitive adhesive layer by a direct method can be obtained.

  The manufacturing apparatus 20 shown in FIG. 1 is typically configured such that the long process liner 5 is wound from a winding roll (not shown) to a winding roll (not shown) via feed rolls 21 and 22. . This aspect is suitable for stably producing a high-quality double-sided pressure-sensitive adhesive tape. Further, the manufacturing apparatus 20 may be configured such that the annular process liner 5 circulates (repeatedly used) through the feed rolls 21 and 22. This embodiment has an advantage that the amount of the process liner 5 used is small.

  FIG. 1 shows an example of continuously performing from the application of the first pressure-sensitive adhesive composition to the completion of the double-sided pressure-sensitive adhesive tape. For example, a long process liner 5 having both surfaces as peeling surfaces is shown. Use the process liner / nonwoven fabric laminate after forming the second pressure-sensitive adhesive layer 2 (that is, after step S30) so that the other surface of the process liner contacts the upper surface 2A of the second pressure-sensitive adhesive layer 2. And may be wound up once. Thereafter, the wound process liner / nonwoven fabric laminate is rewound, and the product liner 3 is bonded to the upper surface 2A of the second pressure-sensitive adhesive layer 2 exposed by the rewound, and the process liner 5 is removed to remove the substrate / product. A double-sided adhesive tape (product) can be obtained by winding up the liner laminate. From the viewpoint of productivity and the like, usually, a mode in which the process from the application of the first pressure-sensitive adhesive composition to the completion of the double-sided pressure-sensitive adhesive tape can be preferably employed.

  Note that the double-sided pressure-sensitive adhesive tape 10 having a cross-sectional shape shown in FIG. 7 can be suitably manufactured, for example, by the following method. The manufacturing method is: a product liner having both sides of a release surface, one side (light release surface) having a release treatment relatively stronger than the other side (heavy release surface). Preparing; applying a first pressure-sensitive adhesive composition to the light release surface of the product liner to form a first pressure-sensitive adhesive layer; bonding one surface of a substrate to the upper surface of the first pressure-sensitive adhesive layer Forming a product liner / substrate laminate; applying a second pressure-sensitive adhesive composition to the other surface of the substrate to form a second pressure-sensitive adhesive layer; and The product liner / substrate laminate constituting the product liner / substrate laminate is brought into contact with the upper surface of the product liner, and the laminate is wound into a roll. In the double-sided pressure-sensitive adhesive tape thus wound in a roll shape, the light release surface of the product liner is in contact with the lower surface of the first pressure-sensitive adhesive layer, and the heavy release surface is in contact with the upper surface of the second pressure-sensitive adhesive layer. Therefore, this double-sided pressure-sensitive adhesive tape can be easily rewound so that the lower surface of the first pressure-sensitive adhesive layer is peeled off from the light release surface of the product liner. That is, the double-sided pressure-sensitive adhesive tape produced by the above-described method is configured such that the first pressure-sensitive adhesive layer is exposed by rewinding from a state wound in a roll shape. This method has an advantage that the double-sided pressure-sensitive adhesive tape can be produced without using a process liner.

As the porous substrate constituting the double-sided pressure-sensitive adhesive tape disclosed herein, a well-known or commonly used nonwoven fabric or other nonwoven fabrics can be preferably used in the field of double-sided pressure-sensitive adhesive tapes. For example, non-woven fabric composed of natural fibers such as wood pulp, cotton, hemp (eg Manila hemp); chemicals such as polyester fiber, rayon, vinylon, acetate fiber, polyvinyl alcohol (PVA) fiber, polyamide fiber, polyolefin fiber, polyurethane fiber Nonwoven fabrics composed of fibers (synthetic fibers); nonwoven fabrics composed of two or more fibers of different materials can be used. Examples of the porous substrate other than the nonwoven fabric include foam sheets made of foams such as foamed polyurethane and foamed polychloroprene rubber; various fabrics; and the like.
The thickness of the porous substrate is not particularly limited. Usually, a substrate having a thickness of about 15 μm to 150 μm (typically about 30 μm to 120 μm, for example, about 50 μm to 100 μm) can be preferably used.

Preferred porous substrates include nonwoven fabrics mainly composed of cellulosic fibers (including natural fibers and regenerated fibers such as rayon, typically natural fibers). In an embodiment in which a nonwoven fabric having such a fiber composition is used for the porous substrate, the effect of applying the present invention can be exhibited particularly well. Moreover, the double-sided adhesive tape which uses the said nonwoven fabric as a base material may have what was intensity | strength and moderate softness | flexibility. The proportion of cellulosic fibers in the nonwoven fabric constituting fiber is typically about 50% by mass or more, preferably about 70% by mass or more, and more preferably about 85% by mass or more. In a preferred embodiment of the invention disclosed herein, a nonwoven fabric whose constituent fibers are substantially composed of cellulosic fibers (for example, 100% hemp) is used as the nonwoven fabric.
The term “nonwoven fabric” as used herein refers to a non-woven fabric for pressure-sensitive adhesive sheets mainly used in the field of pressure-sensitive adhesive tapes and other pressure-sensitive adhesive sheets, and is typically produced using a general paper machine. Non-woven fabric (sometimes called “paper”).

As the product liner, a release liner whose both surfaces are release surfaces, which are well known or commonly used in the field of double-sided pressure-sensitive adhesive tapes, can be appropriately selected and used. For example, a release liner having a configuration in which release treatment is performed on both sides of a long base material can be suitably used. Examples of the base material (exfoliation treatment target) constituting this type of release liner include various resin films, papers, cloths, rubber sheets, foam sheets, metal foils, and composites thereof (for example, paper A sheet having a laminated structure in which an olefin resin is laminated on both sides thereof can be appropriately selected and used. The release treatment can be performed by a conventional method using a known or commonly used release treatment agent (for example, a silicone-based, fluorine-based, or long-chain alkyl-based release treatment agent).
Further, a low-adhesive substrate such as an olefin resin (for example, polyethylene, polypropylene, ethylene-propylene copolymer, polyethylene / polypropylene mixture), a fluorine-based polymer (for example, polytetrafluoroethylene, polyvinylidene fluoride), You may use as a product liner, without performing the peeling process on the surface of this base material. Or you may use what performed the peeling process to the surface (one side or both surfaces) of this low-adhesive base material.

  As the process liner, various release liners whose both surfaces are release surfaces can be used in the same manner as the product liner. For example, the same release liner as the product liner can be preferably used for the process liner. Further, various release liners (for example, a release liner obtained by laminating an olefin resin on one side of the paper and further performing a release process) in which only one side is a release surface may be used as the process liner.

  As an adhesive composition, water dispersion in which various polymers such as acrylic, polyester, urethane, polyether, rubber, silicone, polyamide, and fluorine that can function as an adhesive component are dispersed in water. A type (typically emulsion type) pressure-sensitive adhesive composition can be appropriately selected and used. The solid content concentration of the pressure-sensitive adhesive composition may be, for example, about 30 to 70% by mass. Usually, an adhesive composition having a solid content concentration of about 40 to 65% by mass (for example, about 45 to 55% by mass) can be preferably used.

  The first pressure-sensitive adhesive composition used for forming the first pressure-sensitive adhesive layer by the transfer method and the second pressure-sensitive adhesive composition used for forming the second pressure-sensitive adhesive layer by the direct method may have the same composition. Different compositions may be used. The embodiment in which the same pressure-sensitive adhesive composition is used to form both pressure-sensitive adhesive layers has the advantage that only one type of pressure-sensitive adhesive composition is used. For example, according to the same thickness and manufacturing method, the first and second pressure-sensitive adhesive compositions are selected so that the first pressure-sensitive adhesive composition forms a higher pressure-sensitive adhesive layer than the second pressure-sensitive adhesive composition. By doing, the double-sided adhesive tape which shows better removability can be implement | achieved.

  The first pressure-sensitive adhesive composition used in the transfer method preferably has a viscosity of about 20 Pa · s or less (more preferably about 15 Pa · s or less) measured at 10 ° C. with a B-type viscometer at 10 rpm. Further, a first pressure-sensitive adhesive composition having the viscosity of about 2 Pa · s or more (more preferably about 5 Pa · s or more) is preferable. Since this first pressure-sensitive adhesive composition is applied to the release surface (usually high water repellency), if the viscosity of the composition is too low, holes will form in the pressure-sensitive adhesive layer due to repelling or the thickness will be uneven. Can happen. On the other hand, if the viscosity of the first pressure-sensitive adhesive composition is too high, coatability may be reduced.

  On the other hand, the second pressure-sensitive adhesive composition used in the direct method preferably has a viscosity (30 ° C., 10 rpm) of about 15 Pa · s or less. It is more preferable to use a second pressure-sensitive adhesive composition having a viscosity of about 10 Pa · s or less (more preferably about 5 Pa · s or less, for example, about 3 Pa · s or less). By using the low-viscosity second pressure-sensitive adhesive composition, it is possible to form a second pressure-sensitive adhesive layer that is well impregnated into the porous substrate. According to the double-sided pressure-sensitive adhesive tape including the second pressure-sensitive adhesive layer, better removability can be realized. The lower limit of the viscosity of the second pressure-sensitive adhesive composition is not particularly limited, and may be, for example, about 0.1 Pa · s or more (typically about 0.3 Pa · s or more, for example, about 0.5 Pa · s or more). it can. Since the second pressure-sensitive adhesive composition is directly applied to a porous substrate (cellulosic non-woven fabric, etc.), even if it has a lower viscosity than the first pressure-sensitive adhesive composition applied to the release surface, It is hard to produce. Moreover, since the low-viscosity pressure-sensitive adhesive composition has good penetration into the porous substrate, it is suitable for forming a pressure-sensitive adhesive layer that is well impregnated into the substrate. The fact that the adhesive layer is well impregnated in the base material is advantageous from the viewpoint of preventing adhesive residue on the adherend (improvement of removability).

In a preferred embodiment of the invention disclosed herein, the second pressure-sensitive adhesive composition has a lower viscosity than the first pressure-sensitive adhesive composition (for example, about 1/2 or less, more preferably about the first pressure-sensitive adhesive composition). A composition having a viscosity of 1/3 or less is used. This makes it possible to achieve a high degree of compatibility between repellency prevention in the transfer method and good substrate impregnation in the direct method.
In addition, the viscosity of the pressure-sensitive adhesive composition can be adjusted using a known thickener, diluent (may be a solvent such as water) and the like. Moreover, in the pressure-sensitive adhesive composition whose viscosity changes depending on pH (for example, a pressure-sensitive adhesive composition mainly composed of an acrylic polymer obtained by copolymerizing a monomer having an acidic group), the property is utilized (for example, neutralization). Viscosity may be adjusted).

Application of the pressure-sensitive adhesive composition can be performed by using a conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, or a spray coater. Although not particularly limited, the pressure-sensitive adhesive composition may be applied to form a pressure-sensitive adhesive layer having a thickness of, for example, about 20 μm to 150 μm (typically about 40 μm to 100 μm) after drying (that is, based on solid content). The amount can be about.
From the viewpoint of promoting the crosslinking reaction and improving the production efficiency, the pressure-sensitive adhesive composition is preferably dried under heating. Although it depends on the material of the object to be coated (porous substrate or process liner), usually a drying temperature of about 40 ° C. to 120 ° C., for example, can be preferably used.

The water-dispersed pressure-sensitive adhesive composition preferably used in the technology disclosed herein is mainly composed of an acrylic polymer (that is, the mass of the acrylic polymer in the nonvolatile content (solid content) contained in the pressure-sensitive adhesive composition. An aqueous emulsion-type pressure-sensitive adhesive composition in which the acrylic polymer is dispersed in water is exemplified.
The acrylic polymer is a polymer obtained by polymerizing (typically emulsion polymerization) a monomer material having an alkyl (meth) acrylate, that is, a (meth) acrylic acid ester of alkyl alcohol as a main monomer (main constituent monomer). Can be coalesced. The alkyl (meth) acrylate constituting the monomer raw material is preferably a (meth) acrylic acid ester of an alkyl alcohol having 2 to 20 (more preferably 4 to 10) carbon atoms. Specific examples of the alkyl group in the alkyl alcohol include ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, isopentyl group, hexyl group, heptyl group, 2-ethylhexyl group, isooctyl group, isononyl group, An isodecyl group etc. are mentioned. Particularly preferred alkyl (meth) acrylates include butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate.

  The monomer raw material can contain other monomers (copolymerization components) as optional components in addition to the alkyl (meth) acrylate as the main monomer. The “other monomer” may be one or more selected from various monomers copolymerizable with the alkyl (meth) acrylate used herein. For example, an ethylenically unsaturated monomer having one or more functional groups selected from the group consisting of a carboxyl group, a hydroxyl group, an amino group, an amide group, an epoxy group, and an alkoxysilyl group (functional group-containing monomer) Can be used. Of these, the use of acrylic acid and / or methacrylic acid is preferred. The functional group-containing monomer is used as a constituent component of the monomer raw material together with the alkyl (meth) acrylate as the main monomer, and can serve to introduce a crosslinking point into the acrylic polymer obtained from the monomer raw material. The type and content ratio (copolymerization ratio) of the functional group-containing monomer are appropriately set in consideration of the type and amount of the crosslinking agent used, the type of crosslinking reaction, the desired degree of crosslinking (crosslinking density), and the like. be able to.

  The water-dispersed pressure-sensitive adhesive composition used in the method of the present invention may be obtained by subjecting the monomer raw material as described above to emulsion polymerization. The aspect of the emulsion polymerization is not particularly limited. For example, various known monomer supply methods, polymerization conditions (polymerization temperature, polymerization time, polymerization pressure, etc.), materials used ( Polymerization initiators, surfactants, etc.) can be employed as appropriate. For example, as the monomer supply method, any of a batch charging method, a continuous supply method, a divided supply method, and the like in which all monomer raw materials are supplied to the polymerization vessel at once can be employed. A part or all of the monomer raw material may be preliminarily mixed with water and emulsified, and the emulsion may be supplied into the reaction vessel.

As the polymerization temperature, for example, a temperature of about 20 to 100 ° C. (typically 40 to 80 ° C.) can be employed. Examples of the polymerization initiator include, but are not limited to, azo initiators, peroxide initiators, redox initiators, and the like. The usage-amount of a polymerization initiator can be about 0.005-1 mass part with respect to 100 mass parts of monomer raw materials, for example.
As an emulsifier (surfactant) used for emulsion polymerization, anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium polyoxyethylene lauryl sulfate; polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether Nonionic emulsifiers such as, etc. can be used. Such emulsifiers may be used alone or in combination of two or more. The usage-amount of an emulsifier can be about 0.2-10 mass parts (preferably about 0.5-5 mass parts) with respect to 100 mass parts of monomer raw materials.

  For the above polymerization, conventionally known various chain transfer agents (which can also be grasped as molecular weight regulators or polymerization degree regulators) can be used as necessary. Such a chain transfer agent may be one or more selected from mercaptans such as dodecyl mercaptan (dodecanethiol), glycidyl mercaptan, 2-mercaptoethanol, and the like. Of these, use of dodecanethiol is preferable. The amount of the chain transfer agent used can be, for example, about 0.001 to 0.5 parts by mass with respect to 100 parts by mass of the monomer raw material. The amount used may be about 0.02 to 0.05 parts by mass.

  The pressure-sensitive adhesive composition (preferably an acrylic water-based emulsion-type pressure-sensitive adhesive composition) used in the method disclosed herein contains a general crosslinking agent such as a carbodiimide-based crosslinking agent or a hydrazine-based crosslinking agent as necessary. A crosslinking agent selected from an epoxy crosslinking agent, an isocyanate crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, a metal chelate crosslinking agent, a silane coupling agent, and the like may be blended. These crosslinking agents can be used alone or in combination of two or more.

  The pressure-sensitive adhesive composition may contain a tackifier. As the tackifier, for example, one or two or more selected from various tackifier resins such as rosin resins, rosin derivative resins, petroleum resins, terpene resins, phenol resins, and ketone resins are used. be able to. The blending ratio of the tackifier is, for example, about 50 parts by mass or less with respect to 100 parts by mass of a polymer component (for example, an acrylic polymer in the case of an acrylic aqueous emulsion type adhesive composition) in terms of non-volatile content (solid content). be able to. Usually, it is appropriate that the blending ratio is about 30 parts by mass or less. The lower limit of the tackifier content is not particularly limited, but usually good results can be obtained by setting it to about 1 part by mass or more with respect to 100 parts by mass of the polymer component.

  Commercially available tackifiers include trade names “Superester E-865”, “Superester E-865NT”, “Superester E-650”, “Superester E-786-60” of Arakawa Chemical Industries, Ltd. ”,“ Tamanol E-100 ”,“ Tamanol E-200 ”,“ Tamanol 803L ”,“ Pencel D-160 ”,“ Pencel KK ”; trade names“ YS Polystar S ”,“ YS Polystar T ”of Yashara Chemical Co., Ltd. ”,“ Mighty Ace G ”; and the like, but are not limited thereto. Such tackifiers may be used alone or in combination of two or more. From the viewpoint of increasing the cohesive force in a high temperature environment, for example, a tackifier having a softening point of about 140 ° C. or higher (typically 140 to 180 ° C.) can be preferably used. It is particularly preferable to use a tackifier emulsion which is in the form of an aqueous dispersion (tackifier emulsion) in which such a tackifier is dispersed in water and which does not substantially contain an organic solvent.

  The pressure-sensitive adhesive composition may contain an acid or a base (such as ammonia water) used for the purpose of adjusting pH. Other optional components that can be contained in the composition include aqueous pressure-sensitive adhesives such as viscosity modifiers, leveling agents, plasticizers, fillers, colorants such as pigments and dyes, stabilizers, preservatives, and anti-aging agents. Examples of various additives that are common in the field of compositions are exemplified. About such various additives, conventionally well-known things can be used by a conventional method, and since it does not characterize this invention in particular, detailed description is abbreviate | omitted.

The invention disclosed herein includes the following.
(1) A method of fixing a consumable part to a recycling part using any one of the double-sided adhesive tapes disclosed herein. The method includes a step of crimping the first pressure-sensitive adhesive layer (first adhesive surface) exposed by unwinding the double-sided pressure-sensitive adhesive tape to the consumable part. Typically, the method includes a step of cutting the double-sided pressure-sensitive adhesive tape into an appropriate length before or after pressure bonding to the consumable part. Further, the method includes a step of pressure-bonding the second pressure-sensitive adhesive layer (second sticking surface) exposed by peeling the product liner from the double-sided pressure-sensitive adhesive tape to the recycling component.
(2) A method of manufacturing an article in which a consumable part is fixed to a recycling part. The manufacturing method includes a step of preparing any one of the double-sided pressure-sensitive adhesive tapes disclosed herein. Further, the method includes the step of fixing the consumable part to the recycling part by applying the fixing method of (1).

  Several examples relating to the present invention will be described below, but the present invention is not intended to be limited to those shown in the examples. In the following description, “parts” and “%” are based on mass unless otherwise specified.

The pressure-sensitive adhesive composition used in the following examples was prepared as follows.
[Composition A1]
In a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer, 90 parts of butyl acrylate (BA), 10 parts of 2-ethylhexyl acrylate (2EHA), 4 parts of acrylic acid (AA), γ-methacryloxypropyltri 0.07 part of methoxysilane (Shin-Etsu Chemical Co., Ltd., trade name “KBM-503”), 0.05 part of dodecanethiol (chain transfer agent), 2,2′-azobis [N- ( 2-carboxyethyl) -2-methylpropionamidine] hydrate (product of Wako Pure Chemical Industries, Ltd., trade name “VA-057” was used) 0.1 part, sodium polyoxyethylene alkyl ether sulfate as emulsifier (Kao Corporation product, trade name “Latemul E-118B”) 2 parts and ion-exchanged water 100 parts were charged. Nitrogen gas was introduced into the reaction vessel and the temperature was raised to 60 ° C. while stirring, and the emulsion polymerization reaction was allowed to proceed for 4 hours by maintaining the same temperature for 4 hours. Cooled to. The liquid property was adjusted to pH 7 by adding 10% ammonium water to the polymerization reaction solution. Thus, an aqueous dispersion (emulsion) of an acrylic polymer was obtained.
A tackifier emulsion (Arakawa Chemical Industries, Ltd., trade name “Tamanol E-200NT”, emulsion of polymerized rosin resin with a softening point of 150 ° C.) is adhered per 100 parts of the acrylic polymer emulsion to the acrylic polymer emulsion. An emulsion-type pressure-sensitive adhesive composition (Composition A1) was prepared by adding 20 parts (based on solid content) of the imparting agent. The viscosity of the composition A1 was 8.0 Pa · s. The viscosity of the pressure-sensitive adhesive composition was measured using a B-type viscometer under the conditions of 30 ° C. and 10 rpm.

[Composition A2]
The amount of 10% ammonia water added to the polymerization reaction solution was set to 1/10 of the amount added in the composition A1. About the other point, it carried out similarly to preparation of composition A1, and prepared the emulsion type adhesive composition (composition A2). The viscosity of the composition A2 was 1.0 Pa · s.

[Composition B1]
Same as Composition A1, except that the amount of BA was changed to 70 parts, the amount of 2EHA was changed to 30 parts, the amount of AA was changed to 3 parts, and the amount of γ-methacryloxypropyltrimethoxysilane was changed to 0.03 parts. An aqueous dispersion (emulsion) of an acrylic polymer was obtained. To this acrylic polymer emulsion, the same tackifier emulsion as in composition A1 is added so as to be 30 parts of tackifier per 100 parts of acrylic polymer, and an emulsion-type pressure-sensitive adhesive composition (composition B1) Was prepared. The viscosity of this composition B1 was 8.6 Pa · s.

<Example 1>
It is wound in a roll shape through a double-sided release liner (product liner), and the first adhesive layer provided by the transfer method is the first application surface (the first surface exposed when the roll is unwound) Thus, a double-sided pressure-sensitive adhesive tape was produced in which the second pressure-sensitive adhesive layer formed by the direct method was the second application surface. In forming the first and second pressure-sensitive adhesive layers, the composition A1 was used. As the base material, a nonwoven fabric manufactured by Nippon Daishowa Paperboard Co., Ltd., trade name “F-18 processed paper” was used. As the product liner, a release liner (Kite Chemical Co., Ltd., trade name “SLB-80WD (V2)”) treated on both sides with a silicone release agent was used.
The double-sided pressure-sensitive adhesive tape was produced according to the following procedure. That is, the composition A1 was applied to the release surface of the process liner having the release surface treated with the silicone release agent (the same release liner as the product liner was used), and dried at 100 ° C. for 2 minutes. A pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer) having a thickness of 60 μm was formed on the release surface. One surface of the base material was bonded to the upper surface of the first pressure-sensitive adhesive layer, and the first pressure-sensitive adhesive layer was transferred to the base material to form a process liner / base material laminate. Next, the composition A1 was directly applied to the other surface of the substrate and dried at 100 ° C. for 2 minutes. As a result, a second pressure-sensitive adhesive layer having a thickness of 60 μm was formed on the other surface. One surface of the product liner was bonded to the upper surface of the second pressure-sensitive adhesive layer to form a process liner / substrate / product liner laminate. Next, the process liner is peeled off from the laminate to expose the lower surface of the first pressure-sensitive adhesive layer, and the substrate / product liner laminate is wound up so that the first pressure-sensitive adhesive layer is on the inner side. A double-sided adhesive tape (adhesive tape roll) was obtained.

<Example 2>
In this example, composition B1 was used for forming the first pressure-sensitive adhesive layer (transfer method), and composition A1 was used for forming the second pressure-sensitive adhesive layer (direct method). About the other point, it carried out similarly to Example 1, and obtained the double-sided adhesive tape which concerns on Example 2.

<Example 3>
In this example, composition A2 was used for forming the first pressure-sensitive adhesive layer (transfer method), and composition A1 was used for forming the second pressure-sensitive adhesive layer (direct method). About the other point, it carried out similarly to Example 1, and obtained the double-sided adhesive tape which concerns on Example 2.

<Example 4>
In this example, it is wound in a roll shape through a double-sided release liner (product liner), and the second pressure-sensitive adhesive layer formed by the direct method becomes the first application surface and is provided by the transfer method. A double-sided pressure-sensitive adhesive tape having one pressure-sensitive adhesive layer as the second application surface was produced. In forming the first and second pressure-sensitive adhesive layers, the composition A1 was used. As a base material, the nonwoven fabric made from Daifuku Paper Co., Ltd. and the brand name "SP base paper-14" were used. As the product liner, a release liner manufactured by Kite Chemical Industry Co., Ltd., trade name “SLB-80WD (V2)” was used.
The double-sided pressure-sensitive adhesive tape was produced according to the following procedure. That is, the composition A1 was applied to one release surface of the product liner and dried at 100 ° C. for 2 minutes to form a 60 μm thick adhesive layer (first adhesive layer) on the release surface. One surface of the base material was bonded to the upper surface of the first pressure-sensitive adhesive layer, and the first pressure-sensitive adhesive layer was transferred to the base material to form a product liner / base material laminate. Next, the composition A1 was directly applied to the other surface of the substrate and dried at 100 ° C. for 2 minutes. As a result, a second pressure-sensitive adhesive layer having a thickness of 60 μm was formed on the other surface. This was wound up so that the second pressure-sensitive adhesive layer was inside, and a double-sided pressure-sensitive adhesive tape according to Example 4 was obtained.

The removability of the double-sided pressure-sensitive adhesive tapes according to Examples 1 to 4 was evaluated as follows.
[Removability]
The end of the double-sided pressure-sensitive adhesive tape according to each example was rewound from the roll shape, and the exposed pressure-sensitive adhesive surface (first application surface) was pressure-bonded to the buffer material (consumable part). As the cushioning material, a flame retardant nonwoven fabric manufactured by Amvic Co., Ltd., trade name “Himeron (registered trademark) ULA-E” was used. The cushioning material with the double-sided adhesive tape attached is cut into a strip of 15mm x 150mm, the product liner is peeled off from the back of the double-sided adhesive tape, and the exposed adhesive surface (second adhesive surface) is a resin molded product (recycled) Affixed with a hand roller. As the resin molding, a liquid crystal television manufactured by Sharp Corporation, a plastic casing of model number “LC-37GX3W” was used. Thus, the resin molded product (sample) which fixed the buffering material using the double-sided adhesive tape was stored in a 70 degreeC hot-air circulation type dryer for two weeks. Thereafter, the sample was taken out from the dryer, and allowed to cool by being kept at 23 ° C. and 50% RH for 3 hours. Next, the cushioning material was peeled off from the casing by hand (peeling speed: about 300 mm / min, peeling angle: 90 degrees), and the state of adhesive residue on the casing surface was visually confirmed. As a result, in Example 4, adhesive residue was observed on the surface of the housing in almost the entire area where the double-sided adhesive tape was affixed (poor removability), whereas in Example 1, a small amount of adhesive residue was present. In Example 2, the adhesive residue was further reduced (good removability), and in Example 3, no adhesive residue was observed (excellent removability). The evaluation results of the removability are shown in Table 1 together with the schematic configuration of the double-sided pressure-sensitive adhesive tape according to each example.

  As shown in Table 1, the configuration is such that the pressure-sensitive adhesive layer formed by the direct method is the buffer material side (first application surface) and the pressure-sensitive adhesive layer formed by the transfer method is the housing side (second application surface). The double-sided pressure-sensitive adhesive tape according to Example 4 was poor in removability from the casing. On the other hand, in contrast to Example 4, while using the same pressure-sensitive adhesive composition, according to Example 1 configured such that the pressure-sensitive adhesive layer by the transfer method is on the buffer material side and the pressure-sensitive adhesive layer by the direct method is on the housing side, The removability was remarkably increased. In the double-sided pressure-sensitive adhesive tape according to Example 2 in which the pressure-sensitive adhesive composition used in the transfer method was changed to B1, better removability was obtained. According to Example 3 in which the pressure-sensitive adhesive composition used in the direct method was changed to A2, further excellent removability was realized. This result is presumed to be related to the improvement of the base material impregnation property (throwing property) by reducing the viscosity of the composition used in the direct method.

The adhesive force and holding force of the double-sided pressure-sensitive adhesive tapes according to Examples 1 to 4 were evaluated as follows.
[Adhesive force]
In accordance with JIS Z1528, the peel adhesive strength of the double-sided adhesive tape according to each example was measured for each of the first application surface and the second application surface.
That is, the first application surface or the second application surface of the double-sided pressure-sensitive adhesive tape (20 mm width) according to each example was crimped to a stainless steel (SUS) plate by reciprocating a 2 kg roller. At this time, a polyester film having a thickness of 25 μm was attached in advance to the surface opposite to the surface to be attached to the SUS plate. This was left at 23 ° C. for 20 minutes, and then peeled off 180 ° from the SUS plate at a tensile speed of 300 mm / min using a tensile tester in a measurement environment at a temperature of 23 ° C. and a relative humidity of 50%. (N / 20 mm width) was measured.
Moreover, it replaces with the said SUS board, and the flame-retardant nonwoven fabric (buffer material) used for the said peelability evaluation on the surface of this SUS board is a double-sided adhesive tape (the Nitto Denko Co., Ltd. grade name "No.500"). The test piece affixed in (1) was used, and the adhesive strength (N / 20 mm width) was measured in the same manner as described above except that the test piece was peeled off by 180 °.

[Retention force]
A double-sided pressure-sensitive adhesive tape according to each example was cut into 10 mm to prepare a test piece. The first application surface or the second application surface of the test piece was attached to a bakelite plate so that the application area was 10 mm × 20 mm. At this time, a polyester film having a thickness of 25 μm was attached in advance to the surface opposite to the surface attached to the bakelite plate. A load of 500 g was applied to the free end of the test piece and left at 80 ° C. for 1 hour, and then the deviation of the test piece was measured.
The measurement results of the adhesive force and holding force are shown in Table 2 together with the schematic configuration of the double-sided adhesive tape according to each example.

  As shown in Table 2, the double-sided pressure-sensitive adhesive tape according to Example 4 showed higher adhesive strength on the second sticking surface than on the first sticking surface for both adherends of SUS and cushioning material. . On the other hand, the double-sided pressure-sensitive adhesive tapes according to Examples 1 to 3 showing improved removability as compared with Example 4 are higher on the first application surface than on the second application surface for any adherend. It was confirmed to show adhesive strength. This is presumed to be related to the improvement of removability (preventing adhesive residue on the housing side). In addition, both the double-sided adhesive tapes of Examples 1 to 4 had practically sufficient holding power on both the first and second application surfaces.

1 1st adhesive layer 1A upper surface 1B lower surface (surface, first pasting surface)
2 2nd adhesive layer 2A Upper surface (2nd sticking surface)
3. Product liner (release liner for products)
3A One side 3B The other side 4 Nonwoven fabric (porous substrate)
5 Process liner (release liner for process)
10 Double-sided adhesive tape 12 Buffer material (consumable parts)
14 Resin moldings (recycling parts)
DESCRIPTION OF SYMBOLS 20 Double-sided adhesive tape manufacturing apparatus 23 Base material roll 25 Product liner supply roll 27 Winding roll 30 1st coating part 40 2nd coating part 100 Double-sided adhesive tape 101 1st adhesive layer 101A Upper surface 101B Lower surface (2nd sticking surface) )
102 2nd adhesive layer 102A upper surface (1st sticking surface)
103 Release liner 103A One side 103B The other side 104 Nonwoven fabric (porous substrate)
120 Double-sided adhesive tape manufacturing apparatus 123 Base roll 130 First coating unit 140 Second coating unit

Claims (8)

Double-sided adhesive layer formed from a water-dispersed pressure-sensitive adhesive composition provided on one side and the other side of a porous substrate and wound in a roll shape through a double-sided release liner for products A method for producing an adhesive tape comprising:
Applying the first pressure-sensitive adhesive composition on the release surface of the process release liner to form a first pressure-sensitive adhesive layer;
Bonding one surface of the substrate to the upper surface of the first pressure-sensitive adhesive layer to form a process liner / substrate laminate;
Applying a second pressure-sensitive adhesive composition to the other surface of the substrate to form a second pressure-sensitive adhesive layer;
Bonding one surface of the release liner for product to the upper surface of the second pressure-sensitive adhesive layer to form a process liner / substrate / product liner laminate;
Removing the process release liner from the process liner / substrate / product liner laminate to form a substrate / product liner laminate with the bottom surface of the first adhesive layer exposed; and
Winding the substrate / product liner laminate into a roll by bringing the other surface of the product release liner into contact with the exposed lower surface of the first pressure-sensitive adhesive layer;
A method for producing a double-sided pressure-sensitive adhesive tape, comprising:   The method according to claim 1, wherein a nonwoven fabric mainly composed of a cellulosic material is used as the porous substrate.   The method according to claim 1 or 2, wherein a composition having a lower viscosity than the first pressure-sensitive adhesive composition is used as the second pressure-sensitive adhesive composition.   The method according to any one of claims 1 to 3, wherein an emulsion-type pressure-sensitive adhesive composition mainly composed of the same or different acrylic polymer is used as the first and second pressure-sensitive adhesive compositions.   The double-sided adhesive tape manufactured by the method as described in any one of Claim 1 to 4. Double-sided adhesive layer formed from a water-dispersed pressure-sensitive adhesive composition provided on one side and the other side of a porous substrate and wound in a roll shape through a double-sided release liner for products An adhesive tape,
The first pressure-sensitive adhesive layer provided on one surface of the base material is provided by laminating a pre-formed pressure-sensitive adhesive layer on the base material on the base material,
The second pressure-sensitive adhesive layer provided on the other surface of the base material is provided by directly applying the pressure-sensitive adhesive composition to the base material,
The double-sided pressure-sensitive adhesive tape is configured such that the first pressure-sensitive adhesive layer is exposed by rewinding from the state wound in the roll shape.   The pressure-sensitive adhesive tape according to claim 5 or 6, wherein the pressure-sensitive adhesive tape is used by being attached to a recycling part.   The pressure-sensitive adhesive tape according to claim 5 or 6, which is used for fixing a consumable part to a recycling part.

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