JP5920704B2 - Method for producing releasable adhesive sheet - Google Patents

Description

  The present invention relates to a method for producing a releasable pressure-sensitive adhesive sheet.

  The re-peelable pressure-sensitive adhesive sheet has an adhesive property that can be securely adhered to the surface to be adhered, and has a re-peelable property that can be peeled cleanly without causing adhesive residue or sheet damage after a predetermined period of time. Required. As an example of a conventional re-peelable pressure-sensitive adhesive sheet, Patent Document 1 discloses a method for producing a plastic foam sheet that can be used for buffer packaging, curing, and the like, and can be easily peeled after sticking. This plastic foam sheet is formed by partially applying an ultraviolet curable adhesive in a predetermined pattern on the surface of the foam sheet main body fed out from a roll, and then curing and winding the adhesive by ultraviolet irradiation. Is done.

JP-A-2005-205818

  However, the releasable pressure-sensitive adhesive sheet produced by the conventional method is used in an environment where the adherend surface is likely to be highly humid, such as curing of the lining concrete of the tunnel wall surface. There is a problem that it is easy to peel off, and if the adhesive strength of the pressure-sensitive adhesive is increased to avoid this, there is a problem that peeling after use becomes difficult.

  Then, this invention aims at provision of the manufacturing method of the releasable adhesive sheet which can maintain adhesiveness and removability favorable also in a high-humidity environment.

The object of the present invention is to laminate a non-woven fabric on the upper surface side of a base material and sandwich the non-woven fabric with an adhesive by supplying pressure-sensitive adhesive to the non-woven fabric from above with a pair of coating rolls. A sheet body forming step for forming a sheet body in which a material and the nonwoven fabric are integrated, and a curing step for curing the pressure-sensitive adhesive while supporting the entire lower surface side of the base material and maintaining the sheet body horizontally. The base material is formed by heat-sealing a smoothing sheet made of foamed polyethylene on the back side of a foam cushioning sheet having a large number of foamed portions on the surface, and the sheet body forming step includes This is achieved by a method for producing a releasable pressure-sensitive adhesive sheet comprising a step of laminating the nonwoven fabric on the surface of a smoothing sheet .

  In the method for producing a releasable pressure-sensitive adhesive sheet, the pair of application rolls are preferably arranged above and below the sheet body, and the sheet body forming step is performed on the surface of the upper application roll. It is preferable to include the process of supplying and transferring to the said nonwoven fabric.

  Moreover, it is preferable that the said sheet body formation process includes the process of impregnating the said adhesive to the said nonwoven fabric so that a part of said nonwoven fabric may be exposed from the surface of the said adhesive.

  The pressure-sensitive adhesive is preferably a thermosetting acrylic pressure-sensitive adhesive, and the curing step preferably includes a step of supplying hot air to the upper surface side of the sheet body to heat-dry the pressure-sensitive adhesive.

  Moreover, it is preferable to further include a stacking step of cutting and stacking the sheet bodies to a predetermined length after the curing step.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the releasable adhesive sheet which can maintain adhesiveness and removability favorable also in a high-humidity environment can be provided.

It is a schematic block diagram of the apparatus which enforces the manufacturing method of the releasable adhesive sheet which concerns on one Embodiment of this invention. It is a principal part enlarged view of the apparatus shown in FIG. It is a principal part enlarged view of the other apparatus which enforces the manufacturing method of the releasable adhesive sheet which concerns on one Embodiment of this invention. It is a schematic sectional drawing of the sheet | seat body which comprises a releasable adhesive sheet.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of an apparatus for carrying out a method for producing a releasable pressure-sensitive adhesive sheet according to an embodiment of the present invention. The apparatus shown in FIG. 1 includes a base material roll 10 around which a sheet-like base material 1 is wound, a non-woven fabric roll 20 around which a sheet-like non-woven fabric 2 is wound, and a pressure sensitive adhesive 3 supplied from a tank 31. A pair of coating rolls 30a and 30b that sandwich the material 1 and the nonwoven fabric 2 to form the sheet body 4, a curing device 40 that cures the adhesive 3 of the sheet body 4, and a release paper roll around which the release paper 5 is wound 50, a pair of pressure-bonding rolls 60a and 60b for forming a releasable pressure-sensitive adhesive sheet 6 by pressure-bonding the release paper 5 to the pressure-sensitive adhesive 3 after the sheet 4 is cured, and the releasable pressure-sensitive adhesive sheet 6 to a predetermined length. And a stacking device 70 for cutting and stacking.

  Various materials can be selected as the material of the substrate 1 according to the purpose of use such as curing of concrete, soundproofing and heat insulation, and examples thereof include glass wool, rock wool, aluminum, urethane foam, and foamed polyethylene. When used for curing concrete, it is preferably a known bubble buffer sheet made of polyethylene, polypropylene or the like having a large number of convex bubble portions formed on the surface. When using a bubble cushioning sheet, it is preferable to laminate a smoothing sheet made of foamed polyethylene on the back side opposite to the surface on which the bubble part is formed, by heat-sealing. The unevenness can be relaxed, the adhesion to the concrete surface can be improved, and at the time of peeling, it can be peeled cleanly without leaving an adhesion mark.

The non-woven fabric 2 plays a role of impregnating and holding the pressure-sensitive adhesive 3 and absorbing moisture and moisture on the adherend surface. The basis weight of the nonwoven fabric 2 is preferably 10 g / m ² or more, and preferably 30 g / m ² or more in order to ensure a sufficient amount of impregnation of the pressure-sensitive adhesive 3 and improve water absorption (hygroscopicity). More preferred. The upper limit of the basis weight does not exist in particular, but if it is too large, it becomes too thick and the cost is high, so it is practically 100 g / m ² or less.

  As the pressure-sensitive adhesive 3, the same type as that used for known releasable pressure-sensitive adhesive sheets can be used, and those having thermosetting property and ultraviolet curable property are preferable. When used for curing concrete, a thermosetting acrylic pressure-sensitive adhesive that can withstand high temperature and high humidity can be preferably used as the pressure-sensitive adhesive 3. The viscosity at the time of supply of the pressure-sensitive adhesive 3 is preferably such that the entire nonwoven fabric 2 can be impregnated. For example, a medium viscosity of about 4000 mPa · s at 20 ° C. can be used. The main component of the pressure-sensitive adhesive 3 may be a polymer such as silicone, polyester or polyurethane other than acrylic, and the medium may be either solvent type or aqueous type.

  The base material 1 fed out from the base material roll 10 is sent between the pair of coating rolls 30a and 30b in a state where the base material 1 is lightly stretched by the tension roll 12. On the other hand, the non-woven fabric 2 fed out from the non-woven fabric roll 20 is fed between a pair of coating rolls 30a and 30b so that the feed amount is adjusted by the pair of feed rolls 22a and 22b and is laminated on the upper surface side of the substrate 1. It is done.

  Each of the pair of application rolls 30a and 30b is a hard roll made of a metal material (for example, stainless steel) and the like, and the substrate 1 is connected to the upper application roll 30a by driving the lower application roll 30b. And the nonwoven fabric 2 is conveyed while pinching. In order to increase the holding amount of the pressure-sensitive adhesive 3 of the hard roll 30a, fine irregularities may be formed on the surface of the hard roll 30a. One of the pair of application rolls 30a and 30b may be an elastic roll 30b made of synthetic resin or rubber.

  FIG. 2 is an enlarged view of a main part showing the vicinity of a pair of coating rolls 30a and 30b in the apparatus shown in FIG. The pressure-sensitive adhesive 3 supplied through a gap formed between the surface of the application roll 30a and the supply port 31a of the tank 31 is held on the surface of the upper application roll 30a. The pressure-sensitive adhesive 3 is transferred to the nonwoven fabric 2. Since the base material 1 exists below the nonwoven fabric 2, the pressure-sensitive adhesive 3 impregnated in the nonwoven fabric 2 spreads uniformly over the entire surface by the pressure between the pair of coating rolls 30a and 30b. In this way, a sheet body 4 in which the base material 1 and the nonwoven fabric 2 are integrated by the pressure-sensitive adhesive 3 is obtained. The supply of the pressure-sensitive adhesive 3 to the surface of the upper application roll 30a may be performed by providing a holding roll 32 such as a hard roll as shown in FIG. In FIG. 3, the holding roll 32 has a diameter smaller than the diameter of the coating roll 30a, and is disposed so as to form a slight gap between the holding roll 32 and the coating roll 30a. The rotation axis of the holding roll 32 is located slightly above the rotation axis of the application roll 30a. With this configuration, the pressure-sensitive adhesive 3 can be stored between the coating roll 30a and the holding roll 32, and transferred from the coating roll 30a to the nonwoven fabric 2 with a predetermined coating amount, similarly to the configuration shown in FIG.

  The film thickness of the pressure-sensitive adhesive 3 impregnated in the nonwoven fabric 2 is preferably about the same as the thickness of the nonwoven fabric 2, and can be, for example, about 10 to 100 μm after pinching with a pair of coating rolls 30 a and 30 b. . It is preferable that at least a part of the non-woven fabric 2 is exposed on the surface of the pressure-sensitive adhesive 3, instead of being entirely buried in the pressure-sensitive adhesive 3. The film thickness of the pressure-sensitive adhesive 3 can be set to a desired value by adjusting the size of the gap between the application roll 30a and the tank 31 (or the holding roll 32), for example.

  The sheet body 4 delivered from the pair of application rolls 30a and 30b is conveyed to the curing device 40 by a conveying device 80 formed of a belt conveyor. The curing device 40 includes a drying device 41 that is disposed immediately above the conveying device 80 and supplies hot air from above. The drying device 41 introduces the hot air generated by the electrothermal dryer 42 into the drying furnace 44 through the blowing duct 43 having a plurality of blowing portions 43a along the conveying direction of the conveying device 80, whereby the sheet body The adhesive 3 is heated and dried while 4 passes through the drying furnace 44. In this way, as shown in a schematic cross-sectional view in FIG. 4, a sheet body 4 is obtained in which the pressure-sensitive adhesive 3 impregnated in the nonwoven fabric 2 on the substrate 1 is cured.

  The conveying device 80 preferably uses a belt conveyor so that the entire lower surface side of the sheet body 4 can be supported and conveyed, but other conveying devices such as a roller conveyor may be used. Further, instead of continuously conveying the sheet body 4, it is also possible to stop the sheet body 40 for a predetermined time in the curing device 40 while keeping the sheet body 40 horizontal. The curing device 40 is not limited to the configuration in which the sheet body 4 is heated and dried, and may be, for example, an ultraviolet curing device.

  In the sheet device 4 in which the pressure-sensitive adhesive 3 is cured in the curing device 40, the release paper 5 fed out from the release paper roll 50 is bonded to the surface of the pressure-sensitive adhesive 3 by a pair of pressure-bonding rolls 60a and 60b. In this way, the releasable pressure-sensitive adhesive sheet 6 is manufactured. The stacking device 70 includes a cutting machine 72 that cuts the releasable pressure-sensitive adhesive sheet 6 into a predetermined length, and a stocker 74 that sequentially stacks and holds the cut removable pressure-sensitive adhesive sheets 6. A bundle of removable adhesive sheets 6 sent from 60a and 60b is formed. When applying the releasable pressure-sensitive adhesive sheet of the present invention to the curing of lining concrete on the tunnel wall surface, prepare a bundle of removable pressure-sensitive adhesive sheets 6 cut into a panel shape in advance and transport this bundle to the construction site. Thus, the releasable pressure-sensitive adhesive sheet 6 can be sequentially adhered to the curved arch-shaped concrete surface, and the construction work can be performed quickly and easily.

  As mentioned above, according to the manufacturing method of the releasable pressure-sensitive adhesive sheet of this embodiment, the base material 1 and the non-woven fabric are supplied to the non-woven fabric 2 laminated on the upper surface side of the base material 1 while supplying the pressure-sensitive adhesive 3 from above. 2 is sandwiched between the pair of coating rolls 30a and 30b, so that the sheet body 4 in which the adhesive 3 is uniformly distributed over the entire base material 1 and the nonwoven fabric 2 can be obtained. And since the adhesive 3 is cured while supporting the entire lower surface side of the substrate 1 and maintaining the sheet body 4 horizontally, the adhesion between the substrate 1 and the adhesive 3 can be kept good, Even when the thickness of the substrate 1 is large, wrinkles and broken grooves are hardly generated, and a smooth pressure-sensitive adhesive surface excellent in adhesion and peelability to the adherend surface can be obtained. As a result, when adhering, even if moisture or moisture is present on the adherend surface, the non-woven fabric 2 absorbs water and absorbs moisture and maintains good adhesive strength. The releasable pressure-sensitive adhesive sheet 6 that can be easily peeled off from the surface to be bonded while preventing the interfacial peeling with 3 can be obtained.

  The method for producing a releasable pressure-sensitive adhesive sheet of the present invention can be particularly suitably used for curing concrete that is moisture-released from the surface after placement, but is not limited to this application. It can also be preferably used as a soundproof sheet or a heat insulating sheet in an atmosphere.

DESCRIPTION OF SYMBOLS 1 Base material 2 Nonwoven fabric 3 Adhesive 4 Sheet body 6 Removable adhesive sheet 30a, 30b Coating roll 40 Curing device

Claims (5)

A non-woven fabric is laminated on the upper surface side of the base material, and the non-woven fabric is impregnated with the adhesive by supplying pressure-sensitive adhesive to the non-woven fabric with a pair of coating rolls from above, so that the base material and the non-woven fabric are integrated. Sheet body forming step of forming a sheet body,
A curing step of curing the pressure-sensitive adhesive while supporting the entire lower surface side of the substrate and maintaining the sheet body horizontally,
The base material is formed by heat-sealing a smoothing sheet made of foamed polyethylene on the back surface side of a foam cushioning sheet having a large number of foam portions on the surface,
The said sheet body formation process is a manufacturing method of the releasable adhesive sheet including the process of laminating | stacking the said nonwoven fabric on the surface of the said smoothing sheet . The pair of application rolls are arranged above and below the sheet body,
The said sheet body formation process is a manufacturing method of the releasable adhesive sheet of Claim 1 including the process of supplying the said adhesive to the surface of the said application | coating roll of the upper side, and transcribe | transferring to the said nonwoven fabric.   The releasable pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the sheet body forming step includes a step of impregnating the non-woven fabric with the pressure-sensitive adhesive so that a part of the non-woven fabric is exposed from the surface of the pressure-sensitive adhesive. Production method. The pressure-sensitive adhesive is a thermosetting acrylic pressure-sensitive adhesive,
The said hardening process is a manufacturing method of the releasable adhesive sheet in any one of Claim 1 to 3 including the process of supplying hot air to the upper surface side of the said sheet | seat body, and heating-drying the said adhesive.   The method for producing a releasable pressure-sensitive adhesive sheet according to any one of claims 1 to 4, further comprising a stacking step of cutting and stacking the sheet bodies into a predetermined length after the curing step.

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