CN117120567A - Corrosion-resistant adhesive tape - Google Patents

Abstract

The adhesive tape for corrosion prevention of the present invention comprises an adhesive layer, does not rust in a cyclic corrosion test according to the cyclic D in JIS K5600-7-9, and has an adhesive force of 20N/25mm or more after the cyclic corrosion test. According to the present invention, an adhesive tape for corrosion prevention which is superior in adhesion and corrosion resistance to conventional adhesive tapes can be provided.

Description

Corrosion-resistant adhesive tape

Technical Field

The present invention relates to an adhesive tape for corrosion prevention.

Background

In order to prevent corrosion of iron such as steel or an alloy containing iron, a large amount of corrosion-preventing paint containing zinc is widely used. Zinc is known to be a metal having a lower potential than iron, and has a sacrificial anticorrosive effect, and thus has high corrosion resistance. However, the corrosion prevention using the paint requires a drying step or the like after application, and takes a long time to work, and when local repair is performed in civil engineering such as a bridge, for example, the work efficiency is lowered. In addition, corrosion prevention using a paint is also prone to work unevenness.

In view of the above, conventionally, measures have been taken to impart sacrificial corrosion resistance to an adhesive tape or the like and to improve workability. For example, patent document 1 discloses an anticorrosive method in which a laminate composed of a conductive adhesive layer containing zinc powder, a zinc plate, a resin film, and a stainless steel plate is attached to the outer peripheral surface of a metal pipe. In this corrosion prevention method, zinc powder contained in the adhesive layer and the zinc plate serve as sacrificial anodes, preventing corrosion of the metal piping.

Patent document 2 discloses an anticorrosive member including a conductive adhesive layer containing a conductive material and having a resistance value of a certain value or less, an anticorrosive member including the conductive adhesive layer and a base material, and the like. By using the corrosion-resistant member, both the adhesive property and the sacrificial corrosion resistance can be improved.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 9-242982

Patent document 2: japanese patent application laid-open No. 2019-127606

Disclosure of Invention

Problems to be solved by the invention

However, the adhesive layer in patent document 1 contains 60 to 95 mass% of zinc powder in order to impart conductivity, and thus has low adhesive properties. Therefore, in order to fix the laminate to the metal pipe, a strap is required, and workability cannot be sufficiently improved.

In addition, although the corrosion-resistant member of patent document 2 has excellent adhesive properties and sacrificial corrosion resistance, from the viewpoint of highly preventing peeling from an adherend such as steel material, which occurs due to the influence of weather or the like from the outside, and improving corrosion resistance, there is a demand for a corrosion-resistant adhesive tape having higher adhesive strength after long-term use.

Accordingly, the 1 st object of the present invention is to provide an anticorrosive pressure-sensitive adhesive tape excellent in adhesion and corrosion resistance for a longer period of time than conventional ones.

In addition, the corrosion-resistant member of patent document 2 is excellent in adhesive properties and sacrificial corrosion resistance, and on the other hand, no study on weather resistance has been made. Accordingly, as a result of exposure to light such as ultraviolet light for a long period of time, appearance defects accompanying deterioration of the film occur, or the adhesive force tends to be lowered accompanying deterioration of the adhesive layer.

Accordingly, the present invention has as its object to provide an anticorrosive adhesive tape which does not cause an appearance failure even after being irradiated with light for a long period of time and can maintain an adhesive force at a high level.

Further, the corrosion protection member of patent document 2 has not been studied sufficiently for flexibility of the base material. Therefore, the shape of the adherend having a complicated shape may not be followed, and the corrosion resistance may not be sufficiently exhibited.

Accordingly, the 3 rd problem of the present invention is to provide an anti-corrosive adhesive tape having excellent anti-corrosive properties to an adherend having a complicated shape.

Means for solving the problems

The present inventors have conducted intensive studies. As a result, it has been found that the above problem 1 can be solved by providing an anticorrosive adhesive tape (hereinafter, also referred to as an anticorrosive adhesive tape according to the invention 1) which does not generate rust in a specific cycle corrosion test and has a constant or higher adhesive force after the cycle corrosion test, and the present invention has been completed.

Further, the present inventors have found that the above problem 2 can be solved by providing an anticorrosive adhesive tape (hereinafter, also referred to as an anticorrosive adhesive tape according to the invention 2) comprising a substrate and an adhesive layer provided on one surface of the substrate, wherein the substrate has a gloss retention of 80% or more after a specific accelerated weather resistance test and an adhesive force of 20N/25mm or more after a cyclic corrosion test, and the present invention has been completed.

The present inventors have found that the above problem 3 can be solved by providing an anticorrosive adhesive tape (hereinafter, also referred to as an anticorrosive adhesive tape according to the invention 3) comprising a substrate and an adhesive layer provided on at least one surface of the substrate, wherein the difference between the tensile load of the substrate at 2.5% elongation and the tensile load of the substrate at 0.5% elongation is not more than a predetermined value and the tensile elongation at break of the substrate is not less than a predetermined value, and have completed the present invention.

That is, the present invention provides the following [1] to [18].

[1] An anticorrosive adhesive tape comprising an adhesive layer, which does not rust in a cyclic corrosion test according to cycle D in JIS K5600-7-9, and which has an adhesive force of 20N/25mm or more after the cyclic corrosion test.

[2] The pressure-sensitive adhesive tape for corrosion prevention according to the above [1], further comprising a substrate, wherein the pressure-sensitive adhesive layer is provided on one surface of the substrate.

[3] The adhesive tape for corrosion prevention according to item [2], wherein the substrate has a gloss retention of 80% or more after the accelerated weather resistance test according to JIS K5600-7-7 for 500 hours in cycle A.

[4] The pressure-sensitive adhesive tape for corrosion prevention as described in [2] or [3], wherein a difference between a tensile load when the substrate is subjected to 2.5% elongation and a tensile load when the substrate is subjected to 0.5% elongation is 30N/24mm or less, and a tensile elongation at break is 100% or more.

[5] An anticorrosive adhesive tape comprising a base material and an adhesive layer provided on one surface of the base material, wherein the base material has a gloss retention of 80% or more after an accelerated weather resistance test according to JIS K5600-7-7 for 500 hours and an adhesive force of 20N/25mm or more after a cycle corrosion test according to JIS K5600-7-9 for cycle D.

[6] An anticorrosive adhesive tape comprising a base material and an adhesive layer provided on at least one surface of the base material, wherein the difference between the tensile load of the base material when subjected to 2.5% elongation and the tensile load of the base material when subjected to 0.5% elongation is 30N/24mm or less, and the tensile elongation at break is 100% or more.

[7] The pressure-sensitive adhesive tape for corrosion prevention as described in any one of the above [2] to [6], wherein the substrate has an Elmendorf tear strength of 0.6N or more as measured by an Elmendorf tear method according to JIS K7128-2 (1998).

[8] The pressure-sensitive adhesive tape for corrosion prevention according to any one of the above [2] to [7], wherein the base material is a resin film having a coating film on a surface thereof.

[9] The pressure-sensitive adhesive tape for corrosion prevention according to any one of the above [2] to [8], wherein the substrate is at least 1 selected from the group consisting of an acrylic film and a fluorine film.

[10] The pressure-sensitive adhesive tape for corrosion prevention according to any one of the above [1] to [9], wherein the pressure-sensitive adhesive layer has a thickness of 25 μm or more.

[11] The pressure-sensitive adhesive tape for corrosion prevention as described in any one of the above [1] to [10], wherein the pressure-sensitive adhesive layer contains a metal having a lower potential than iron.

[12] The pressure-sensitive adhesive tape for corrosion prevention as described in [11], wherein the metal having a lower potential than iron is zinc.

[13] The pressure-sensitive adhesive tape for corrosion prevention according to the above [11] or [12], wherein the pressure-sensitive adhesive layer contains a conductive material other than the metal having a lower potential than iron.

[14] The pressure-sensitive adhesive tape for corrosion prevention according to item [13], wherein the conductive material is carbon nanotubes.

[15] The pressure-sensitive adhesive tape for corrosion prevention according to any one of the above [1] to [14], wherein the pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive.

[16] The pressure-sensitive adhesive tape for corrosion prevention according to item [1], wherein the pressure-sensitive adhesive tape comprises the pressure-sensitive adhesive layer and a metal layer provided on one surface of the pressure-sensitive adhesive layer, and the metal layer is a layer of a metal having a lower potential than iron.

[17] The pressure-sensitive adhesive tape for corrosion prevention according to any one of the above [2] to [16], wherein a metal layer is provided between the base material and the pressure-sensitive adhesive layer, and the metal layer is a layer of a metal having a lower potential than iron.

[18] The pressure-sensitive adhesive tape for corrosion prevention as described in the above [16] or [17], wherein the metal layer is a zinc layer.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, an adhesive tape for corrosion prevention excellent in long-term adhesion and corrosion resistance can be provided. Further, according to the present invention, it is possible to provide an anticorrosive adhesive tape which does not cause an appearance failure even after being irradiated with light for a long period of time and which can maintain the adhesive force at a high level. Further, according to another embodiment of the present invention, an adhesive tape for corrosion prevention having excellent corrosion resistance to an adherend surface having a complicated shape can be provided.

Drawings

Fig. 1 is a schematic cross-sectional view showing an embodiment of the adhesive tape for corrosion prevention of the present invention.

Fig. 2 is a schematic cross-sectional view showing another embodiment of the adhesive tape for corrosion prevention of the present invention.

Fig. 3 is a schematic cross-sectional view showing another embodiment of the adhesive tape for corrosion prevention of the present invention.

Fig. 4 is a schematic cross-sectional view showing another embodiment of the adhesive tape for corrosion prevention of the present invention.

Fig. 5 is a schematic view showing an evaluation method of the convex portion following property of the adhesive tape for corrosion prevention of the present invention.

Detailed Description

[ anticorrosive pressure-sensitive adhesive tape (1 st invention) ]

The anticorrosive pressure-sensitive adhesive tape according to invention 1 will be described below.

The adhesive tape for corrosion prevention of the present invention is an adhesive tape for corrosion prevention comprising an adhesive layer, which does not cause rust in a cyclic corrosion test according to cycle D in JIS K5600-7-9, and which has an adhesive force of 20N/25mm or more after the cyclic corrosion test.

< presence of rust in cycle Corrosion test >

The anticorrosive adhesive tape of the present invention does not cause rusting in JIS K5600-7-9 (paint general protocol-section 7: coating film design, long-term durability-section 9: coating film spray/drying/wetting), cycle D) as described in JIS K5600-7-9 (paint general protocol-section 7: coating film long-term durability-section 9: cyclic corrosion protocol-brine spray/drying/wetting), as described in the description of the invention, as described in the following. Therefore, the adhesive tape for corrosion prevention of the present invention is excellent in corrosion resistance. In this cyclic corrosion test, if rust is generated, the corrosion resistance of the corrosion-resistant adhesive tape becomes insufficient. The occurrence of rust can be suppressed by adjusting the composition, thickness, and the like of the pressure-sensitive adhesive layer provided in the pressure-sensitive adhesive tape for corrosion prevention.

The presence or absence of rust generation in the cycle corrosion test was confirmed as follows.

The pressure-sensitive adhesive tape for corrosion prevention of the present invention was adhered to a test plate defined in JIS K5600-7-9 to prepare a test piece. At this time, the test piece was produced by bonding the surface of the test piece in contact with the adhesive layer of the etching resist adhesive tape. The dimensions of the adhesive tape for corrosion prevention were 150mm in length and 70mm in width.

Next, with respect to the test piece, a cut-in wound was introduced from the side of the pressure-sensitive adhesive tape for corrosion prevention. The incised wound is formed by intersecting 2 linear wounds (i.e., the wound is introduced in a × symbol shape). At this time, the length of 1 lesion was 70mm, and 2 lesions intersected at 90 ℃. The incision was applied to a test plate as a substrate using a single-blade incision tool as defined in JIS K5600-7-9.

Then, using a test piece having a cut-in wound, a salt spray test was performed based on cycle D of appendix 1 of JIS K5600-7-9. The test was run for 28 cycles (total 168 hours).

The test piece after the salt spray test was observed to confirm the presence or absence of rust in the incised wound portion.

< adhesion after cycle Corrosion test >

The adhesive force of the adhesive tape for corrosion protection of the present invention after the cyclic corrosion test is 20N/25mm or more. If the adhesive force is less than 20N/25mm, the adhesive force for a long period becomes insufficient, and the adhesive tape for corrosion prevention is liable to peel off from an adherend such as a steel material, and thus the corrosion resistance is lowered.

The adhesion after the cycle corrosion test is preferably 25N/25mm or more, more preferably 30N/25mm or more, and still more preferably 40N/25mm or more, from the viewpoint of improving the adhesion and improving the corrosion resistance. The higher the adhesion, the better, but in practice, the 200N/25mm or less.

The adhesion after the cyclic corrosion test of the adhesive tape for corrosion resistance was measured as follows.

The anticorrosive adhesive tape of the present invention was attached to a stainless steel plate (SUS plate) to prepare a sample for evaluating adhesive force. At this time, the adhesive force evaluation sample was prepared by bonding the SUS plate surface to the adhesive layer of the anti-corrosive adhesive tape. The dimensions of the adhesive tape for corrosion prevention were set to 100mm in length and 25mm in width.

Using this sample for evaluating adhesion, a salt spray test was performed based on cycle D of appendix 1 of JIS K5600-7-9. The test was run for 28 cycles (total 168 hours).

The adhesive force evaluation sample after the salt spray test was subjected to a release test of the anticorrosive adhesive tape to measure the adhesive force. The peeling test was performed by a tensile tester under conditions of a peeling angle of 180℃and a peeling speed of 300 mm/min at a temperature of 23℃and a 50RH%, and the section average value of the detected load (N) was used as the adhesive force.

< gloss retention in accelerated weathering test >

The pressure-sensitive adhesive tape of the present invention preferably further comprises a substrate, and an adhesive layer is provided on one surface of the substrate.

In this case, from the viewpoint of improvement in weather resistance, it is preferable that the gloss retention of the substrate is 80% or more after the accelerated weather resistance test according to cycle a in JIS K5600-7-7 is performed for 500 hours. If the gloss retention is 80% or more, the progress of deterioration of the base material itself can be suppressed when the pressure-sensitive adhesive tape for corrosion prevention is irradiated with light for a long period of time, and the appearance of the pressure-sensitive adhesive tape for corrosion prevention is less likely to deteriorate. The substrate can block light such as sunlight (particularly ultraviolet rays), inhibit deterioration of the adhesive layer, and maintain the adhesive force of the anticorrosive adhesive tape.

From such a viewpoint, the gloss retention of the substrate constituting the etching resist adhesive tape of the present invention is preferably 85% or more, more preferably 90% or more. The higher the gloss retention, the better, with an upper limit of 100%.

The gloss retention of the anticorrosive adhesive tape after the accelerated weather resistance test can be measured by the following method.

An anticorrosive pressure-sensitive adhesive tape (width 25mm, length 100 mm) was attached, and the specular gloss was measured on the surface of the tape from the substrate side by a gloss meter (for example, manufactured by horiba, ltd., product name: IG-340 "). The specular gloss was measured in accordance with JIS K5600-4-7 using a 60℃gloss meter. The specular gloss obtained by the measurement at this time was set to specular gloss a. Then, with respect to the tape, an accelerated weather resistance test according to cycle A in JIS K5600-7-7 was conducted for 500 hours. After the accelerated weathering test was performed, the specular gloss of the base material of the tape was measured by the same method as that performed before the test was performed. The specular gloss obtained by measurement after the test was set as specular gloss B. The gloss retention of the base material of the tape was calculated from the 2 specular gloss obtained in the above manner. The expression for determining the gloss retention is as follows.

Gloss retention (%) = (specular gloss B/specular gloss a) ×100

< adhesive force decrease Rate >)

The pressure-sensitive adhesive tape for corrosion prevention of the present invention preferably has a decrease in adhesion of 15% or less, more preferably 10% or less, and still more preferably 6% or less, as measured by the cycle corrosion test according to cycle D in JIS K5600-7-9. The adhesive force decrease rate is equal to or lower than the upper limit value, whereby the adhesive force of the anti-corrosion adhesive tape can be kept at a predetermined value or higher for a long period of time. The lower the adhesive strength decrease rate of the etching resist adhesive tape, the better the lower the adhesive strength decrease rate, and the lower the adhesive strength decrease rate is, the lower the adhesive strength decrease rate is.

The adhesive force decrease rate can be calculated from the initial adhesive force before the cycle corrosion test and the adhesive force after the cycle corrosion test by the following equation.

Adhesive force decrease rate (%) = (initial adhesive force-adhesive force after test)/initial adhesive force×100

< difference in tensile load >

The base material of the anticorrosive adhesive tape of the present invention preferably has a difference between the tensile load when it is subjected to 2.5% elongation and the tensile load when it is subjected to 0.5% elongation (hereinafter, may be simply referred to as "difference in tensile load") of 30N/24mm or less. The difference in tensile load refers to the tensile load relative to each 2% elongation in the substantially elastic region. When the difference in tensile load is small, it is easy to adhere to the adherend following the elongation of the adherend, and even if the difference is adhered to the adherend, stress due to shrinkage or the like is less likely to occur after the adhesion, and thus the adhesion after the adhesion becomes high.

When the difference in tensile load is 30N/24mm or less, the adhesion of the corrosion-resistant adhesive tape is improved by suppressing shrinkage of the corrosion-resistant adhesive tape when the corrosion-resistant adhesive tape is adhered to an adherend having a complicated shape such as a welded portion after the pipe is welded. In addition, the adhesive is easy to follow and adhere to an adherend having a complex shape. From such a viewpoint, the difference in tensile load is preferably 27N/24mm or less, more preferably 25N/24mm or less. The lower limit value of the difference in tensile load is not particularly limited, but is preferably 1N/24mm or more, more preferably 3N/24mm or more, from the viewpoint of imparting a certain mechanical strength.

The difference in tensile load was measured in the MD direction and TD direction of the base material, respectively, and the larger one was used. In the case where the MD direction and the TD direction are not clear, the difference between the tensile loads is preferably the largest. The difference in tensile load can be obtained by the measurement method described in the examples.

< elongation at break in tension >

The substrate used in the anticorrosive adhesive tape of the present invention preferably has a tensile elongation at break of 100% or more. When the tensile elongation at break of the base material is 100% or more, when the pressure-sensitive adhesive tape is to be attached to a surface having a complicated shape, cracking of the pressure-sensitive adhesive tape is suppressed, and adhesion of the pressure-sensitive adhesive tape to an adherend is likely to be satisfactory. From such a viewpoint, the tensile elongation at break of the base material is preferably 200% or more, more preferably 300% or more.

On the other hand, the upper limit value of the tensile elongation at break of the base material is not particularly limited, but is preferably 1500% or less, more preferably 1000% or less, from the viewpoint of mechanical strength and the like.

The tensile elongation at break was measured in the MD direction and TD direction of the substrate, respectively, and the smaller one was used. In the case where the MD direction and the TD direction are not clear, the minimum tensile elongation at break is preferably used. The tensile elongation at break can be obtained by the measurement method described in the examples.

< Elmendorf tear Strength >)

The substrate used in the anticorrosive adhesive tape of the present invention preferably has an elmendorf tear strength of 0.6N or more. When the elmendorf tear strength of the base material is 0.6N or more, cracking of the pressure-sensitive adhesive tape for corrosion prevention is suppressed and adhesion of the pressure-sensitive adhesive tape for corrosion prevention to an adherend is easily improved when the pressure-sensitive adhesive tape for corrosion prevention is to be attached to a surface having a complicated shape. From such a viewpoint, the elmendorf tear strength of the base material is preferably 0.8N or more, more preferably 1N or more.

On the other hand, the upper limit value of the elmendorf tear strength of the base material is not particularly limited, but is preferably 5N or less, more preferably 3N or less, from the viewpoint of mechanical strength and the like.

The elmendorf tear strength was measured in the MD direction and TD direction of the substrate, respectively, and the smaller one was used. In the case where the MD direction and the TD direction are not clear, the minimum elmendorf tear strength is preferably used. The Elmendorf tear strength can be determined by the Elmendorf tear method according to JIS K7128-2 (1998).

In addition, the difference in tensile load, tensile elongation at break, and elmendorf tear strength of the substrate may be adjusted to be within the above ranges by appropriately selecting the material used for the substrate, the thickness of the substrate, and the like.

< Material used for substrate >

Examples of the substrate used in the present invention include sheet materials such as a resin film and a nonwoven fabric.

Examples of the resin film include polyolefin resin films such as polypropylene resin films, polyethylene resin films, and ethylene-vinyl acetate copolymer (EVA) resin films, polyester resin films, polyamide resin films, acrylic resin films, polyurethane resin films, polystyrene resin films, polyvinyl chloride resin films, ethylene-vinyl acetate resin films, acrylonitrile resin films, fluorine-based films, polycarbonate resin films, AES resin films, and ASA resin films.

The nonwoven fabric is, for example, a nonwoven fabric made of synthetic resin fibers such as polyamide-based, polyester-based, polyacrylic-based, polyolefin-based, polyurethane-based, and the like.

These sheet materials may be used singly or in combination of 1 or more than 2. The base material is preferably a resin film from the viewpoint of protecting the pressure-sensitive adhesive layer and improving the following property and adhesion of the tape to the adherend.

The resin film may be a single-layer film or a multilayer film formed by laminating 2 or more kinds of the above films.

From the viewpoint of improving weather resistance, an ultraviolet absorber, a light stabilizer (HALS), and the like may be blended in the resin constituting the base material. In addition, from the viewpoint of improvement in weather resistance, the base material may be a resin film having a coating film on the surface. The coating film is preferably a weather resistant coating film. The weather-resistant coating film may contain at least 1 selected from the group consisting of ultraviolet absorbers and light stabilizers.

Among the above, the resin film is preferable from the viewpoint of improving weather resistance, and for example, an acrylic film, a fluorine film, a polycarbonate film, a polyvinyl chloride film, an AES resin film, an ASA resin film, or the like can be preferably used as the substrate used in the present invention. By using these substrates, weather resistance can be imparted to the substrates without using an ultraviolet absorber or a light stabilizer, and without applying a weather resistant coating. Thus, the ultraviolet absorber and the light stabilizer can be prevented from exuding. In addition, the labor and time for applying the coating material on the surface of the substrate can be eliminated, and the production efficiency of the adhesive tape for corrosion prevention can be improved.

Among these substrates, at least 1 selected from the group consisting of acrylic films and fluorine films is preferably used.

In addition, the acrylic film is particularly excellent for protecting the pressure-sensitive adhesive layer because the bonding force between atoms in the acrylic resin as a main component is strong and the transmittance of ultraviolet rays is low. In addition, it is considered that the fluorine-based film has high weather resistance by the strong interatomic bonding force between the fluorine atom and other atoms.

Among the above, the base material used in the present invention is preferably a polyolefin resin film, more preferably a polypropylene resin film, a polyethylene resin film, an EVA resin film, or a multilayer film of 2 or more films selected from them, from the viewpoint of improving the following property and adhesion of the tape to an adherend. In the case of using a polyethylene resin film as a base material, the polyethylene to be used is not particularly limited, and examples thereof include low-density polyethylene (LDPE, density: less than 0.930 g/cm) ³ ) Medium density polyethylene (MDPE, density: 0.930g/cm ³ The above and less than 0.942g/cm ³ ) High density polyethylene (HDPE, density: 0.942g/cm ³ Above), linear Low Density Polyethylene (LLDPE), and the like. Among them, LDPE, MDPE, LLDPE is preferable.

< thickness of substrate >

The thickness of the base material is not particularly limited, but is preferably 10 to 1000. Mu.m, more preferably 20 to 400. Mu.m, still more preferably 20 to 100. Mu.m, still more preferably 25 to 80. Mu.m. When the thickness of the base material is equal to or greater than these lower limit values, the base material can function as a support, and the adhesive layer can be easily and appropriately protected from ultraviolet rays or the like. Further, the thickness of the base material is not less than the upper limit value, so that workability is improved and the base material can be easily handled as a tape.

< adhesive layer >)

The adhesive tape for corrosion prevention of the present invention comprises an adhesive layer. Hereinafter, the adhesive layer will be described. The pressure-sensitive adhesive layer is the same as in all of the pressure-sensitive adhesive tape for corrosion prevention according to the invention 1, the pressure-sensitive adhesive tape for corrosion prevention according to the invention 2, and the pressure-sensitive adhesive tape for corrosion prevention according to the invention 3.

Accordingly, the description of the pressure-sensitive adhesive layer in the pressure-sensitive adhesive tape for corrosion protection according to invention 1 described below is also applicable to the pressure-sensitive adhesive layers in the pressure-sensitive adhesive tapes for corrosion protection according to inventions 2 and 3 described below.

(Metal having a lower potential than iron)

The adhesive layer preferably contains a metal having a lower potential than iron. By containing a metal having a lower potential than iron (hereinafter, also referred to as "sacrificial corrosion-preventing metal"), the adhesive tape has sacrificial corrosion resistance, and the corrosion resistance of the adhesive tape is improved. The sacrificial corrosion-preventing metal is dispersed in an adhesive constituting the adhesive layer.

Examples of the sacrificial corrosion-preventing metal include cadmium, chromium, zinc, manganese, and aluminum, and among them, zinc and aluminum are preferable, and zinc is particularly preferable. By using zinc, the sacrificial corrosion resistance is excellent.

The sacrificial corrosion-preventing metal may be dispersed in the binder in any form as a filler, such as a particle shape, a flake shape, a spindle shape, etc., but is preferably in a particle shape. The sacrificial corrosion-preventing metal is in the form of particles, and thus is easily dispersed in the adhesive layer with little decrease in the adhesion of the adhesive layer.

In the present specification, the particle shape is a particle shape in which the ratio (aspect ratio) of the length in the major axis direction to the length in the minor axis direction is small, and for example, the aspect ratio is 3 or less, preferably 2 or less. The particle shape is not particularly limited, and may be spherical, or may be amorphous such as powder. The particle diameter of the metal in the form of particles is, for example, 1 to 500. Mu.m, preferably 1 to 200. Mu.m. In the present specification, the particle size refers to an average particle size measured by a laser diffraction method.

The content of the metal for sacrificial corrosion prevention in the adhesive layer is, for example, 0.5 to 20% by mass, preferably 1 to 12% by mass, and more preferably 2 to 10% by mass, based on the total amount of the adhesive layer.

If the content of the sacrificial corrosion-preventing metal is not less than the lower limit, the sacrificial corrosion resistance is improved, and if it is not more than the upper limit, the adhesion is increased.

The adhesive layer also preferably does not contain a sacrificial corrosion-preventing metal. In the case where the sacrificial corrosion-preventing metal is not contained, the adhesive force of the corrosion-preventing adhesive tape is maintained higher than in the case of containing the sacrificial corrosion-preventing metal, and peeling from the adherend is made difficult, whereby water and oxygen are blocked, and corrosion resistance is easily improved.

(conductive Material)

The pressure-sensitive adhesive layer preferably contains a conductive material other than the sacrificial corrosion-preventing metal. If the conductive material is contained, electrons emitted when the sacrificial corrosion-preventing metal is ionized are easily moved to the adherend, and the sacrificial corrosion resistance is easily improved.

The conductive material may be 1 or 2 or more selected from a carbon-based material, a metal oxide-based material, an ionic polymer, and a conductive polymer.

Examples of the carbon-based material include carbon black, graphite, graphene, carbon nanotubes, and acetylene black. Examples of the metal-based material include metals having a higher potential than iron, such as gold, silver, copper, nickel, or an alloy containing these metals, and iron. Examples of the metal oxide material include Indium Tin Oxide (ITO), antimony Trioxide (ATO), fluorine-doped tin oxide (FTO), and zinc oxide. Examples of the conductive polymer include polyacetylene, polypyrrole, PEDOT (polyethylene dioxythiophene), PEDOT/PSS (a complex of polyethylene dioxythiophene and polystyrene sulfonic acid), polythiophene, polyaniline, poly (p-phenylene), polyfluorene, polycarbazole, polysilane, and derivatives thereof. Examples of the ionic polymer include sodium polyacrylate and potassium polyacrylate.

The conductive material may be used alone in an amount of 1 kind or in an amount of 2 or more kinds.

Among the above, the conductive material is preferably a carbon-based material, and more preferably a carbon nanotube.

(carbon nanotubes)

The adhesive layer preferably contains carbon nanotubes. By containing the carbon nanotubes, the sacrificial corrosion resistance of the adhesive layer is improved, and the adhesive force can be maintained high, so that an adhesive tape for corrosion prevention having both high adhesive force and sacrificial corrosion resistance can be easily obtained. This is presumably because, although the carbon nanotubes are conductive materials, the amount required to exhibit a certain sacrifice corrosion resistance is small compared to other types of conductive materials, and therefore the degree of decrease in adhesion is small.

Carbon nanotubes are tubular materials formed from carbon. The carbon nanotubes have excellent electrical characteristics, and if they are compounded with a resin or the like, a sheet or the like having high conductivity can be formed. The carbon nanotubes are those in which graphite sheets having a hexagonal mesh-like carbon array are rolled into a cylindrical structure, and the rolled material is referred to as single-walled carbon nanotubes, and the rolled material is referred to as multi-walled carbon nanotubes.

In the etching resist adhesive tape according to an embodiment of the present invention, the type of the carbon nanotube is not particularly limited, and may be any of single-walled carbon nanotubes, multi-walled carbon nanotubes, and a mixture containing them in an arbitrary ratio. Carbon nanotubes produced by various methods such as arc discharge method, laser evaporation method, and chemical vapor deposition method (CVD method) can be used.

The average diameter of the carbon nanotubes is preferably 1 to 100nm, more preferably 2 to 15nm. The average length of the carbon nanotubes is preferably 0.1 to 1000. Mu.m, more preferably 10 to 500. Mu.m. The aspect ratio (average length/average diameter) of the carbon nanotubes is preferably 10 to 100000, more preferably 500 to 30000.

The diameter of a carbon nanotube means the outer diameter in the case of a single-walled carbon nanotube, and means the outer diameter of a tube located at the outermost side in the case of a multi-walled carbon nanotube. The diameter and length of the carbon nanotubes may be measured in an image obtained by observation with a TEM (transmission electron microscope), for example, and the average diameter and average length may be obtained by arithmetic average of any 50.

The content of the conductive material in the adhesive layer is preferably 0.005 to 10 mass%, more preferably 0.005 to 5 mass%, even more preferably 0.006 to 3 mass%, and even more preferably 0.006 to 2 mass%, based on the total amount of the adhesive layer, from the viewpoint of sacrificing corrosion resistance and adhesion of the adhesive layer.

When the conductive material is carbon nanotubes, the content of the carbon nanotubes in the adhesive layer is preferably 0.0005 to 0.7 mass%, more preferably 0.005 to 0.05 mass%, and even more preferably 0.006 to 0.045 mass%, based on the total amount of the adhesive layer.

If the content of the carbon nanotubes is above these lower limits, the sacrificial corrosion resistance tends to be improved, and if the content of the carbon nanotubes is below these upper limits, the adhesion tends to be improved.

(adhesive)

The adhesive layer is preferably formed by an adhesive. The type of the adhesive is not particularly limited, but acrylic adhesives, rubber adhesives, urethane adhesives, silicone adhesives, and the like may be mentioned. They may be used alone or in combination.

Among them, the adhesive layer is preferably formed by an acrylic adhesive.

(acrylic adhesive)

The acrylic pressure-sensitive adhesive is a pressure-sensitive adhesive containing an acrylic polymer obtained by polymerizing a polymerizable monomer containing an alkyl (meth) acrylate monomer (a).

In the present specification, the term alkyl (meth) acrylate refers to a concept including both alkyl acrylate and alkyl methacrylate, and other similar terms are the same. The term "polymerizable monomer" is a concept that includes not only a compound having no repeating unit but also a compound copolymerized with the alkyl (meth) acrylate monomer (a), and may include a monomer itself having a repeating unit such as the olefin polymer (C) described later.

((meth) acrylic acid alkyl ester monomer (A))

The alkyl (meth) acrylate monomer (a) is an ester of (meth) acrylic acid and an aliphatic alcohol, and is preferably an alkyl ester of an aliphatic alcohol having 2 to 14 carbon atoms, more preferably 4 to 10 carbon atoms, derived from an alkyl group of the aliphatic alcohol. When the number of carbon atoms of the alkyl group is within this range, the adhesive strength can be easily improved, and the storage modulus at 23℃of the adhesive to be described later can be easily adjusted to a predetermined range.

Specific examples of the alkyl (meth) acrylate monomer (a) include ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, and tetradecyl (meth) acrylate.

Among them, n-butyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, more preferably n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, or a combination thereof is preferable.

The alkyl (meth) acrylate monomers may be used alone or in combination of 2 or more.

The structural unit derived from the alkyl (meth) acrylate monomer (a) constitutes a main component in the adhesive layer, and the content thereof is generally 30 mass% or more, preferably 50 mass% or more, and more preferably 70 mass% or more, based on the total amount of the adhesive layer. In this way, if the content of the alkyl (meth) acrylate monomer (a) is made large, a desired adhesive force can be imparted to the adhesive layer. In order to contain a certain amount or more of other components, the content of the structural unit derived from the alkyl (meth) acrylate monomer (a) is, for example, 97% by mass or less, preferably 95% by mass or less, and more preferably 90% by mass or less.

The content of the structural unit derived from the alkyl (meth) acrylate monomer (a) in the pressure-sensitive adhesive layer is substantially the same as the content of the alkyl (meth) acrylate monomer (a) in the pressure-sensitive adhesive composition described later, and therefore can be expressed by substitution. The components other than the component (A), such as the components (B) and (C) described below, are also similar.

(polar group-containing vinyl monomer (B))

The polymerizable monomer preferably contains a polar group-containing vinyl monomer (B) in addition to the alkyl (meth) acrylate monomer (a). The polar group-containing vinyl monomer (B) has a polar group and a vinyl group. By using the polar group-containing monomer (B), the adhesion to an adherend can be easily improved.

Examples of the polar group-containing vinyl monomer (B) include vinyl monomers having a hydroxyl group such as vinyl carboxylate (e.g., vinyl acetate), carboxylic acid (e.g., vinyl (meth) acrylate) and itaconic acid), anhydrides thereof, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, caprolactone-modified (meth) acrylate, polyoxyethylene (meth) acrylate, and polyoxypropylene (meth) acrylate, (meth) acrylonitrile, N-vinylpyrrolidone, N-vinylcaprolactam, N-vinyllaurolactam, (meth) acryloylmorpholine, (meth) acrylamide, dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, and dimethylaminomethyl (meth) acrylate.

Among them, vinyl-containing carboxylic acids such as (meth) acrylic acid and itaconic acid, and anhydrides thereof are preferable, and (meth) acrylic acid is more preferable, and acrylic acid is still more preferable. These polar group-containing vinyl monomers (B) may be used alone or in combination of 2 or more.

When the polar group-containing vinyl monomer (B) is used, the content of the structural unit derived from the polar group-containing vinyl monomer (B) in the pressure-sensitive adhesive layer is preferably 1 to 15 parts by mass, more preferably 2 to 12 parts by mass, and even more preferably 3 to 10 parts by mass, relative to 100 parts by mass of the structural unit derived from the alkyl (meth) acrylate-based monomer (a). When the content of the polar group-containing vinyl monomer (B) is in such a range, the adhesive strength of the pressure-sensitive adhesive tape for corrosion prevention can be easily improved.

(olefin Polymer (C))

The polymerizable monomer preferably further comprises an olefin polymer (C) having a polymerizable bond at one end. By using such an olefin polymer (C), the adhesive force of the adhesive tape for corrosion prevention can be easily improved.

The polymerizable bond is an unsaturated carbon-carbon bond polymerizable with a polymerizable monomer, and examples thereof include an unsaturated double bond, and preferable examples thereof include a (meth) acryloyl group and the like.

The olefin polymer (C) may be a polyolefin having a (meth) acryloyl group at one end. The polyolefin is a polymer of an aliphatic hydrocarbon compound having a double bond such as ethylene, propylene, butane, butadiene, or isoprene, or a hydrogenated product thereof.

Examples of the polyolefin having a (meth) acryloyl group at one end include polyethylene having a (meth) acryloyl group at one end, which is prepared by reacting polyethylene having an epoxy group at one end with (meth) acrylic acid. Further, polybutadiene having a (meth) acryloyl group at one end or a hydride thereof may be mentioned, and as a commercial product thereof, "L-1253" manufactured by Laryku corporation and the like may be mentioned.

The number average molecular weight of the olefin polymer (C) is preferably 500 to 20000, more preferably 1000 to 10000. The number average molecular weight may be measured by Gel Permeation Chromatography (GPC) and calculated using a standard curve of standard polystyrene.

The content of the structural unit derived from the olefin polymer (C) in the pressure-sensitive adhesive layer is preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass, and even more preferably 4 to 12 parts by mass, relative to 100 parts by mass of the structural unit derived from the alkyl (meth) acrylate monomer (a).

(crosslinking agent (D))

The polymerizable monomer preferably further contains a crosslinking agent. The crosslinking agent may be a polyfunctional monomer having 2 or more vinyl groups, and preferably a polyfunctional (meth) acrylate having 2 or more (meth) acryloyl groups. If a polyfunctional monomer is used, the adhesive force of the adhesive layer can be easily adjusted to an appropriate range.

Examples of the polyfunctional (meth) acrylate include, but are not particularly limited to, polymers such as hexanediol di (meth) acrylate, ethoxylated bisphenol a di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated glyceryl triacrylate, neopentyl glycol adipate diacrylate, and polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and liquid hydrogenated 1, 2-polybutadiene di (meth) acrylate. Among these polyfunctional (meth) acrylates, polymers are preferred, and liquid hydrogenated 1, 2-polybutadiene diacrylate is more preferred. As a commercially available product of liquid hydrogenated 1, 2-polybutadiene diacrylate, there may be mentioned "TEAI-1000" manufactured by Nippon Caesada Co.

The content of the structural unit derived from the crosslinking agent in the pressure-sensitive adhesive layer is preferably 0.1 to 4 parts by mass, more preferably 0.3 to 3 parts by mass, and even more preferably 0.5 to 2 parts by mass, relative to 100 parts by mass of the structural unit derived from the alkyl (meth) acrylate monomer (a).

(tackifying resin)

From the viewpoint of improving the adhesive force, the acrylic adhesive may contain a tackifying resin. The tackifying resin is preferably a tackifying resin having low polymerization inhibition such as a hydrogenated terpene resin, a hydrogenated rosin, a disproportionated rosin resin, and a petroleum resin. Among them, hydrogenated materials are preferable from the viewpoint of inhibiting polymerization reaction if the tackifying resin has a large number of double bonds, and hydrogenated petroleum resins are preferable.

The softening point of the tackifier resin is preferably about 95 ℃ or higher from the viewpoint of improving the cohesive force and adhesive force of the adhesive, but it is preferable to include a substance of 120 ℃ or higher, for example, a substance of 95 ℃ or higher and lower than 120 ℃ may be used in combination with a substance of 120 ℃ or higher and 150 ℃ or lower. The softening point may be measured by the ring and ball method defined in JIS K2207.

The content of the tackifying resin in the acrylic pressure-sensitive adhesive is preferably 5 to 40 parts by mass, more preferably 7 to 35 parts by mass, and even more preferably 10 to 25 parts by mass, based on 100 parts by mass of the structural unit derived from the alkyl (meth) acrylate monomer (a).

(microparticles)

The acrylic binder may contain particulates. By containing the fine particles, the adhesive force can be improved.

Examples of the fine particles include inorganic hollow particles such as glass spheres, volcanic ash spheres, and fly ash spheres, organic hollow particles formed from polymethyl methacrylate, acrylonitrile-1, 1-dichloroethylene copolymer, polystyrene, and phenol resin, inorganic fine particles such as glass beads, silica beads, and synthetic mica, and organic fine particles such as polyethyl acrylate, polyurethane, polyethylene, and polypropylene.

The content of the fine particles in the acrylic pressure-sensitive adhesive is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 0.7 to 5 parts by mass, based on 100 parts by mass of the structural unit derived from the alkyl (meth) acrylate monomer (a).

(other Components)

The acrylic adhesive used for the adhesive layer may contain, in addition to the above components, various additives conventionally used in adhesives, such as plasticizers, softeners, pigments, dyes, photopolymerization initiators, and flame retardants.

(acrylic adhesive and method for producing adhesive layer)

The acrylic pressure-sensitive adhesive can be obtained by irradiating a pressure-sensitive adhesive composition containing the polymerizable monomer, and optionally, a sacrificial corrosion-preventing metal and a conductive material with light to polymerize the polymerizable monomer. In addition, the adhesive composition may contain at least 1 of the above tackifying resins, microparticles, and other ingredients as needed.

To be more specific, first, a polymerizable monomer, a sacrificial corrosion-preventing metal and a conductive material, which are optionally mixed, and a tackifying resin, fine particles, and other components, which are optionally mixed, are put into a reaction vessel such as a glass vessel and mixed to obtain an adhesive composition.

Next, in order to remove dissolved oxygen in the adhesive composition, an inert gas such as nitrogen is generally supplied and oxygen is purged. Further, the pressure-sensitive adhesive layer can be obtained by applying the pressure-sensitive adhesive composition to a release sheet, or applying the pressure-sensitive adhesive composition to a support such as a resin film, a woven fabric, or a nonwoven fabric, and then irradiating the support with light to polymerize the polymerizable monomer.

The step from the application or impregnation of the adhesive composition to the irradiation of light is preferably performed under an inert gas atmosphere or in a state where oxygen is blocked by a film or the like.

In the present production method, the pressure-sensitive adhesive composition obtained by mixing the components may be prepolymerized before being applied to a release sheet, a support, or the like in order to increase the viscosity.

(rubber-based adhesive)

Next, a rubber-based adhesive used for the adhesive layer will be described. The rubber-based adhesive contains a rubber component and a tackifying resin, and as the rubber component, a styrene-isoprene block copolymer is preferably used. The diblock ratio of the styrene-isoprene block copolymer is preferably 25 to 70% by mass, more preferably 30 to 65% by mass, and even more preferably 45 to 60% by weight. Here, the diblock means a diblock formed from styrene and isoprene. By setting the diblock ratio to the above range, the adhesion is easily improved. In addition, the styrene-isoprene block copolymer contains not only diblock but also a triblock structure having 3 or more blocks such as a triblock structure composed of styrene, isoprene and styrene blocks.

The amount of styrene in the styrene-isoprene block copolymer is not particularly limited, but is preferably 14 to 24% by mass, more preferably 15 to 18% by mass. If the styrene content is 14 mass% or more, the adhesive tends to be highly aggregated. If the content is 24 mass% or less, the cohesion is appropriately large, and the adhesion is easily exhibited.

The molecular weight of the styrene-isoprene block copolymer is not particularly limited, but is preferably 100,000 ～ 400,000, more preferably 150,000 ～ 250,000, in terms of mass average molecular weight. The mass average molecular weight herein refers to a value measured as a molecular weight in terms of polystyrene by GPC (gel permeation chromatography).

The tackifying resin used in the rubber-based adhesive may be any of various tackifying resins, but petroleum-based resins, terpene resins, and coumarone resins are preferably used. The tackifier resin may be used alone or in combination of 1 or 2 or more kinds, but it is preferable to use a petroleum resin in combination with at least 1 kind selected from terpene resins and coumarone resins. By combining such tackifying resins, the adhesive force is easily improved.

The petroleum resin may be an aliphatic petroleum resin (C5 petroleum resin), an alicyclic petroleum resin, an aromatic petroleum resin, or the like, and is preferably an aliphatic petroleum resin from the viewpoint of compatibility with the styrene-isoprene block copolymer. The petroleum resin preferably has a softening point of about 90 to 120 ℃.

Further, as the terpene resin, a substance having a softening point of about 80 to 120 ℃ can be used, but from the viewpoint of securing adhesion, a substance having a softening point of less than 100 ℃ is preferable. In order to secure the cohesive force, the coumarone resin preferably has a softening point of 110 to 130 ℃, more preferably 115 to 125 ℃.

The tackifier resin is preferably 60 to 250 parts by mass, more preferably 100 to 200 parts by mass, and even more preferably 110 to 180 parts by mass, per 100 parts by mass of the rubber component. By setting the mixing amount of the tackifying resin to the above range, the cohesive force can be improved and appropriate adhesive force can be provided.

When the petroleum resin is used in combination with at least 1 selected from the group consisting of terpene resins and coumarone resins, the petroleum resin is preferably 50 to 200 parts by mass, more preferably 60 to 150 parts by mass, and still more preferably 60 to 110 parts by mass, relative to 100 parts by mass of the rubber component. On the other hand, the terpene resin is preferably 10 to 70 parts by mass, more preferably 20 to 60 parts by mass, and still more preferably 30 to 50 parts by mass, per 100 parts by mass of the rubber component. Further, the coumarone resin is preferably 10 to 60 parts by mass, more preferably 15 to 50 parts by mass, and even more preferably 20 to 40 parts by mass, per 100 parts by mass of the rubber component.

The rubber-based adhesive may contain the fine particles as in the case of the acrylic-based adhesive, and may contain a sacrificial anticorrosive metal, a conductive material, a softener, an antioxidant, a filler, and the like as required.

(urethane-based adhesive)

The urethane-based binder is not particularly limited, and examples thereof include urethane resins obtained by reacting at least a polyol with a polyisocyanate compound. Examples of the polyol include polyether polyol, polyester polyol, polycarbonate polyol, and polycaprolactone polyol. Examples of the polyisocyanate compound include diphenylmethane diisocyanate, toluene diisocyanate, and 1, 6-hexamethylene diisocyanate. These urethane binders may be used alone or in combination of 2 or more.

As the urethane-based adhesive, a urethane resin obtained by reacting a urethane polyol with a polyfunctional isocyanate-based curing agent can be used. The polyurethane polyol may be obtained by reacting the above polyol with a polyisocyanate compound or by reacting the polyol with a polyisocyanate compound and a chain extender such as diamine. The polyfunctional isocyanate-based curing agent may be any compound having 2 or more isocyanate groups, and the isocyanate compound may be used.

The urethane-based adhesive may contain the fine particles in addition to the urethane resin, and may contain a tackifying resin, a sacrificial corrosion-preventing metal, a conductive material, a softener, an antioxidant, a filler, and the like as necessary.

(Silicone-based adhesive)

Examples of the silicone-based adhesive include addition-reaction type, peroxide-curing type, and condensation-reaction type silicone-based adhesives. Among them, from the viewpoint of being capable of curing at a low temperature in a short time, an addition reaction type silicone-based adhesive is preferably used. In addition, the addition reaction type silicone-based adhesive is cured when the adhesive layer is formed. When an addition reaction type silicone-based adhesive is used as the silicone-based adhesive, the silicone-based adhesive may contain a catalyst such as a platinum catalyst.

The silicone-based adhesive may contain fine particles, and a crosslinking agent and various additives for controlling adhesion may be added.

(storage modulus G')

The adhesive layer preferably has a storage modulus G' at 23 ℃ of 5 to 100 Pa. If the storage modulus G' at 23 ℃ is within the above range, the force (hereinafter, also referred to as self-repairing force) for returning the damaged portion to the original position is increased when the adhesive layer is damaged by external impact or the like. As a result, the occurrence of rust is suppressed, and the corrosion resistance is improved.

The storage modulus G' of the pressure-sensitive adhesive layer at 23 ℃ is more preferably 20 to 80 tens of thousands of Pa, and still more preferably 30 to 60 tens of thousands of Pa, from the viewpoint of improving self-repairing ability and corrosion resistance.

For example, DVA-200 (Teteup Session Co., ltd.) can be used as the storage modulus G' in shear mode: 10Hz, strain amount: 0.1%, temperature range: -100 ℃, and the temperature rising speed is as follows: and (3) measuring the dynamic viscoelasticity spectrum at the condition of 10 ℃ per minute.

(thickness)

The thickness of the adhesive layer is preferably 25 μm or more, more preferably 100 μm or more. By setting the thickness to 100 μm or more, the self-repairing force and the like are improved, and thus the corrosion resistance of the pressure-sensitive adhesive tape for corrosion resistance can be improved, and the adhesive force can be easily improved. From such a viewpoint, the thickness of the pressure-sensitive adhesive layer is more preferably 200 μm or more, still more preferably 300 μm or more, still more preferably 500 μm or more. The upper limit of the thickness of the pressure-sensitive adhesive layer is not particularly limited, but from the viewpoint of obtaining an effect of improving the corrosion resistance corresponding to the thickness, the thickness of the pressure-sensitive adhesive layer is, for example, 3000 μm or less, preferably 2000 μm or less, and more preferably 1500 μm or less.

[ constitution of adhesive tape for Corrosion prevention ]

The pressure-sensitive adhesive tape for corrosion prevention of the present invention may be a double-sided pressure-sensitive adhesive tape or a single-sided pressure-sensitive adhesive tape. The layer structure of the etching resist adhesive tape of the present invention will be described below with reference to the drawings.

As shown in fig. 1, the etching resist adhesive tape 10 is preferably a double-sided adhesive tape called a base-free double-sided tape and composed only of an adhesive layer 11 (i.e., a separate adhesive layer). By using the pressure-sensitive adhesive tape 10 for corrosion prevention composed only of the pressure-sensitive adhesive layer 11, the thickness of the tape can be made thin while maintaining good corrosion resistance.

The anti-corrosive adhesive tape of each figure is used by adhering the surface 11A of the adhesive layer 11 to an adherend as an adhesive surface.

As shown in fig. 2, the pressure-sensitive adhesive tape 10 for corrosion prevention may be a single-sided pressure-sensitive adhesive tape having a substrate 12 and a pressure-sensitive adhesive layer 11 provided on one surface of the substrate 12. Thereby, the adhesive layer 11 can be protected by the base material 12.

Further, although not shown, the pressure-sensitive adhesive tape for corrosion prevention may be a double-sided pressure-sensitive adhesive tape provided with a base material and pressure-sensitive adhesive layers provided on both sides of the base material. In this case, each adhesive layer is as described above.

As described above, the adhesive layer in the present invention may not contain a metal having a lower potential than iron. In this case, in order to improve the corrosion resistance of the corrosion-resistant adhesive tape 10, as shown in fig. 3, the corrosion-resistant adhesive tape 10 preferably includes an adhesive layer 11 and a metal layer 13 provided on one surface of the adhesive layer 11, and the metal layer 13 is a layer of a metal having a lower potential than iron. The metal having a lower potential than iron is not particularly limited, but the metal layer 13 is more preferably a zinc layer. Specifically, the metal layer 13 may be formed by adhering a metal foil made of a metal having a lower potential than iron to the surface of the adhesive layer 11. The metal layer 13 may be a metal film formed by coating the surface of the pressure-sensitive adhesive layer 11 with a metal by sputtering, vacuum evaporation, or the like.

The metal layer 13 is formed directly on the adhesive layer 11. That is, the metal constituting the metal layer 13, which has a lower potential than iron, is in contact with the adhesive layer 11. In this way, if a metal having a lower potential than iron is in contact with the adhesive layer 11, electrons emitted during ionization can easily move to the adhesive layer 11, and thus the corrosion resistance of the corrosion-resistant adhesive tape 10 is improved. In this case, too, the pressure-sensitive adhesive layer 11 preferably contains a conductive material other than a metal having a lower potential than iron from the viewpoint of the corrosion resistance of the pressure-sensitive adhesive tape 10.

The thickness of the metal layer 13 is preferably 2.5 μm or more. If the thickness of the metal layer 13 is 2.5 μm or more, electrons obtained by ionization of the metal in the metal layer 13 can be sufficiently supplied to the metal layer 13, and the sufficient corrosion resistance of the corrosion-resistant adhesive tape 10 can be maintained. The thickness of the metal layer 13 is more preferably 5 μm or more from the viewpoint of improving the corrosion resistance of the pressure-sensitive adhesive tape 10 for corrosion resistance. In addition, from the viewpoint of ensuring flexibility of the pressure-sensitive adhesive tape 10 for corrosion prevention, improving handleability of the pressure-sensitive adhesive tape 10 for corrosion prevention, and the like, the thickness of the metal layer 13 is preferably 200 μm or less, more preferably 100 μm or less.

As shown in fig. 4, the pressure-sensitive adhesive tape 10 for corrosion prevention may further include a base material 12 and a metal layer 13 provided on one surface of the base material 12, wherein the pressure-sensitive adhesive layer 11 is provided on one surface of the metal layer 13, and the metal layer 13 is a layer of a metal having a lower potential than iron. Since the metal layer 13 is protected by the base material 12, the corrosion resistance of the adhesive tape 10 for corrosion resistance can be further improved. In this case, too, the pressure-sensitive adhesive layer 11 preferably contains a conductive material other than a metal having a lower potential than iron from the viewpoint of the corrosion resistance of the pressure-sensitive adhesive tape 10. In this case, the metal layer 13 may be bonded to the base material 12 by an adhesive or the like, or may be formed on the base material 12 by sputtering, vacuum deposition, or the like.

In the case where the corrosion-resistant adhesive tape includes a metal layer as a layer of a metal having a potential lower than that of iron, the adhesive layer may contain a metal having a potential lower than that of iron. Thus, the corrosion resistance of the corrosion-resistant adhesive tape can be further improved by both the metal having a lower potential than iron in the metal layer and the metal having a lower potential than iron in the adhesive layer.

The pressure-sensitive adhesive tape of the present invention can be used to attach a release sheet to the surface of a pressure-sensitive adhesive layer. The release sheet is preferably released from the pressure-sensitive adhesive layer before the use of the etching resist pressure-sensitive adhesive tape, and the pressure-sensitive adhesive layer is exposed and bonded to the adherend through the exposed pressure-sensitive adhesive layer. For example, in the double-sided pressure-sensitive adhesive tape, a release sheet may be attached to both sides of the tape, or a release sheet may be attached to only one side of the tape. In the single-sided pressure-sensitive adhesive tape, a release sheet is preferably attached to one side of the exposed pressure-sensitive adhesive layer.

The release sheet preferably uses a resin film, but the surface to be bonded to the pressure-sensitive adhesive layer is preferably a release-treated surface subjected to release treatment with a silicone release agent or the like.

The pressure-sensitive adhesive tape for corrosion prevention of the present invention is used by bonding various adherends, and the type of the adherend is not particularly limited. The pressure-sensitive adhesive tape for corrosion prevention of the present invention is preferably used by adhering to the surface of an adherend made of various metal materials because of excellent adhesion and corrosion resistance. As the metal material, a metal material containing at least 1 selected from iron and an alloy containing iron is preferable. Specific examples of the iron-containing alloy include various steels such as nickel-chromium steel, nickel-chromium-molybdenum steel, chromium-molybdenum steel, alloy steel such as manganese steel, and carbon steel.

[ anticorrosive pressure-sensitive adhesive tape (2 nd invention) ]

The anticorrosive pressure-sensitive adhesive tape according to invention 2 will be described below.

The anticorrosive adhesive tape according to claim 2 of the present invention is an anticorrosive adhesive tape comprising a substrate and an adhesive layer provided on one surface of the substrate, wherein the substrate has a gloss retention of 80% or more after the accelerated weather resistance test according to JIS K5600-7-7 for 500 hours in cycle a. Further, the adhesive force of the anticorrosive adhesive tape according to invention 2 after the cyclic corrosion test according to the cyclic D in JIS K5600-7-9 is 20N/25mm or more.

The anticorrosive adhesive tape according to invention 2 of the present invention has a gloss retention of 80% or more after 500 hours of accelerated weathering test according to cycle A in JIS K5600-7-7. If the gloss retention is less than 80%, the corrosion-resistant adhesive tape deteriorates due to deterioration of the substrate itself when irradiated with light for a long period of time, and the appearance of the corrosion-resistant adhesive tape deteriorates. In addition, the substrate cannot sufficiently block light such as sunlight (particularly ultraviolet rays), the adhesive layer also deteriorates, and the adhesive force of the anticorrosive adhesive tape decreases. Therefore, if a coating having weather resistance is not taken from the tape Fang Tubu or the like, it is difficult to suppress the decrease in adhesive force.

From such a viewpoint, the gloss retention of the substrate constituting the etching resist adhesive tape of the present invention is preferably 85% or more, more preferably 90% or more. The higher the gloss retention, the better, with an upper limit of 100%.

The gloss retention of the anticorrosive adhesive tape after the accelerated weather resistance test can be measured by the same method as described in the anticorrosive adhesive tape according to the invention 1.

The adhesive force of the anticorrosive adhesive tape according to claim 2 of the present invention after the cyclic corrosion test is 20N/25mm or more. If the adhesive force is less than 20N/25mm, the adhesive force for a long period becomes insufficient, and the adhesive tape for corrosion prevention is liable to peel off from an adherend such as a steel material, and thus the corrosion resistance is lowered.

The adhesion after the cycle corrosion test is preferably 25N/25mm or more, more preferably 30N/25mm or more, and even more preferably 40N/25mm or more, from the viewpoint of improving the adhesion and improving the corrosion resistance. The higher the adhesion, the better, but in practice, the 200N/25mm or less.

The method for measuring the adhesive force after the cycle corrosion test is as described in the above-mentioned adhesive tape for corrosion protection according to the invention 1, and the description thereof is omitted.

From the viewpoint of improvement of the corrosion resistance over a long period of time, the corrosion-resistant adhesive tape according to invention 2 is preferably free from generation of rust in the cycle corrosion test, as described in the corrosion-resistant adhesive tape according to invention 1. The description of the "presence or absence of rust in the cycle corrosion test" given in the corrosion-resistant adhesive tape according to the invention 1 is applicable to the corrosion-resistant adhesive tape according to the invention 2, and the description thereof is omitted.

In addition, regarding the pressure-sensitive adhesive tape for corrosion prevention according to the invention 2, it is preferable that the requirements of "difference in tensile load", "tensile elongation at break", "elmendorf tear strength" described in the pressure-sensitive adhesive tape for corrosion prevention according to the invention 1 are satisfied from the viewpoint of following the shape of an adherend having a complicated shape and exhibiting excellent corrosion resistance. The matters described in the description of the anticorrosive adhesive tape according to the invention 1 are applicable to the anticorrosive adhesive tape according to the invention 2, and the description thereof is omitted.

< substrate >

The substrate of the etching resist adhesive tape according to claim 2 may be the substrate described in the etching resist adhesive tape according to claim 1, without any particular limitation. The descriptions of the "material used for the substrate" and "thickness of the substrate" in the etching resist tape according to the invention 1 are applicable to the etching resist tape according to the invention 2, and the descriptions thereof are omitted.

< adhesive layer >)

The etching resist adhesive tape according to claim 2 includes an adhesive layer on at least one surface of a substrate. The pressure-sensitive adhesive layer is similar to the pressure-sensitive adhesive layer in the etching-resistant pressure-sensitive adhesive tape according to the invention 1, and therefore, description thereof is omitted.

Structure of adhesive tape for anticorrosion

As shown in fig. 2, the etching resist tape 10 according to the invention 2 is preferably a single-sided adhesive tape comprising a base material 12 and an adhesive layer 11 provided on one side of the base material 12. Thereby, the adhesive layer 11 can be protected by the base material 12.

The anti-corrosive adhesive tape of each figure is used by adhering the surface 11A of the adhesive layer 11 to an adherend as an adhesive surface.

Although not shown, the pressure-sensitive adhesive tape for corrosion prevention may be a double-sided pressure-sensitive adhesive tape provided with a base material and pressure-sensitive adhesive layers on both sides of the base material.

As described above, the adhesive layer in the present invention may not contain a metal having a lower potential than iron. In this case, in order to improve the corrosion resistance of the corrosion-resistant adhesive tape 10, as shown in fig. 4, the corrosion-resistant adhesive tape 10 preferably further includes a metal layer 13 between the base material 12 and the adhesive layer 11, and the metal layer 13 is a layer of a metal having a lower potential than iron. The metal having a lower potential than iron is not particularly limited, but the metal layer 13 is more preferably a zinc layer. Specifically, the metal layer 13 may be bonded to the base material 12 by an adhesive or the like, or may be formed on the base material 12 by sputtering, vacuum deposition, or the like. The metal layer 13 may be a metal film formed by coating the surface of the pressure-sensitive adhesive layer 11 with a metal by sputtering, vacuum evaporation, or the like.

The metal layer 13 is directly formed on the pressure-sensitive adhesive layer 11 in such a manner as to be sandwiched between the base material 12 and the pressure-sensitive adhesive layer 11. That is, the metal constituting the metal layer 13, which has a lower potential than iron, is in contact with the adhesive layer 11. In this way, if a metal having a lower potential than iron is in contact with the adhesive layer 11, electrons emitted during ionization can easily move to the adhesive layer 11, and thus the corrosion resistance of the corrosion-resistant adhesive tape 10 is improved. In this case, from the viewpoint of the corrosion resistance of the corrosion-resistant adhesive tape 10, the adhesive layer 11 preferably contains a conductive material other than a metal having a lower potential than iron.

The thickness of the metal layer 13 is preferably 2.5 μm or more. If the thickness of the metal layer 13 is 2.5 μm or more, electrons obtained by ionization of the metal in the metal layer 13 can be sufficiently supplied to the metal layer 13, and the sufficient corrosion resistance of the corrosion-resistant adhesive tape 10 can be maintained. The thickness of the metal layer 13 is more preferably 5 μm or more from the viewpoint of improving the corrosion resistance of the pressure-sensitive adhesive tape 10 for corrosion resistance. In addition, from the viewpoint of ensuring flexibility of the pressure-sensitive adhesive tape 10 for corrosion prevention, improving handleability of the pressure-sensitive adhesive tape 10 for corrosion prevention, and the like, the thickness of the metal layer 13 is preferably 200 μm or less, more preferably 100 μm or less.

The etching resist adhesive tape according to claim 2 may be formed by attaching a release sheet to the surface of the adhesive layer. The release sheet is preferably released from the pressure-sensitive adhesive layer before the use of the etching resist pressure-sensitive adhesive tape, and the pressure-sensitive adhesive layer is exposed and bonded to the adherend through the exposed pressure-sensitive adhesive layer. More specifically, the release sheet is preferably attached to the surface 11A, which is the surface opposite to the surface on which the base material or the metal layer 13 is provided, of the surfaces of the pressure-sensitive adhesive layer.

The release sheet preferably uses a resin film, but the surface to be bonded to the pressure-sensitive adhesive layer is preferably a release-treated surface subjected to release treatment with a silicone release agent or the like.

The etching resist pressure-sensitive adhesive tape according to claim 2 is used by attaching various adherends, and the type of the adherend is not particularly limited. The pressure-sensitive adhesive tape for corrosion prevention of the present invention is preferably used by adhering to the surface of an adherend made of various metal materials because of excellent adhesion and corrosion resistance. As the metal material, a metal material containing at least 1 selected from iron and an alloy containing iron is preferable. Specific examples of the iron-containing alloy include various steels such as nickel-chromium steel, nickel-chromium-molybdenum steel, chromium-molybdenum steel, alloy steel such as manganese steel, and carbon steel.

[ anticorrosive pressure-sensitive adhesive tape (3 rd invention) ]

The anticorrosive pressure-sensitive adhesive tape according to invention 3 will be described below.

The anticorrosive adhesive tape according to claim 3 of the present invention comprises a substrate and an adhesive layer provided on at least one surface of the substrate. In the adhesive tape for corrosion prevention, the difference between the tensile load of the base material when it is subjected to 2.5% elongation and the tensile load when it is subjected to 0.5% elongation is 30N/24mm or less, and the tensile elongation at break is 100% or more.

The difference between the tensile load at 2.5% elongation and the tensile load at 0.5% elongation (difference between the tensile loads) of the base material of the anticorrosive adhesive tape according to claim 3 is 30N/24mm or less. The difference in tensile load refers to the tensile load relative to each 2% elongation in the substantially elastic region. When the difference in tensile load is small, it is easy to adhere to the adherend following the elongation of the adherend, and even if the difference is made to adhere to the adherend, stress due to shrinkage or the like after the adhesion is less likely to occur, so that the adhesion after the adhesion becomes high.

When the difference in tensile load exceeds 30N/24mm, if the corrosion-resistant adhesive tape is adhered to an adherend having a complicated shape, such as a welded portion after the pipe is welded, the corrosion-resistant adhesive tape may shrink, and the adhesion of the corrosion-resistant adhesive tape may become insufficient. In addition, it is not easy to follow and adhere an adherend having a complicated shape. From such a viewpoint, the difference in tensile load is preferably 27N/24mm or less, more preferably 25N/24mm or less. The lower limit value of the difference in tensile load is not particularly limited, but is preferably 1N/24mm or more, more preferably 3N/24mm or more, from the viewpoint of imparting a certain mechanical strength.

The difference in tensile load was measured in the MD direction and TD direction of the base material, respectively, and the larger one was used. In the case where the MD direction and the TD direction are not clear, the difference between the tensile loads is preferably the largest. The difference in tensile load can be obtained by the measurement method described in the examples.

The base material used in the anticorrosive adhesive tape of the present invention has a tensile elongation at break of 100% or more. If the tensile elongation at break of the base material is less than 100%, the pressure-sensitive adhesive tape may be cracked when the pressure-sensitive adhesive tape is to be attached to a surface having a complicated shape, and the adhesion of the pressure-sensitive adhesive tape to an adherend may be insufficient. From such a viewpoint, the tensile elongation at break of the base material is preferably 200% or more, more preferably 300% or more.

On the other hand, the upper limit value of the tensile elongation at break of the base material is not particularly limited, but is preferably 1500% or less, more preferably 1000% or less, from the viewpoint of mechanical strength and the like.

The tensile elongation at break was measured in the MD direction and TD direction of the substrate, respectively, and the other one was used. In the case where the MD direction and the TD direction are not clear, the minimum tensile elongation at break is preferably used. The tensile elongation at break can be obtained by the measurement method described in the examples.

In addition, the difference in tensile load and tensile elongation at break of the base material can be adjusted to be within the above ranges by appropriately selecting the material used for the base material, the thickness of the base material, and the like.

In addition, regarding the pressure-sensitive adhesive tape for corrosion prevention according to invention 3, it is preferable that the requirement of "elmendorf tear strength" described in the pressure-sensitive adhesive tape for corrosion prevention according to invention 1 is satisfied from the viewpoint of following the shape of an adherend having a complicated shape and exhibiting excellent corrosion resistance. The description of the "elmendorf tear strength" in the etching resist adhesive tape according to invention 1 is applicable to the etching resist adhesive tape according to invention 3, and the description thereof is omitted.

From the viewpoint of improving the long-term corrosion resistance, the corrosion-resistant adhesive tape according to invention 3 is preferably free from rust generation in the cycle corrosion test, as described in the above-mentioned corrosion-resistant adhesive tape according to invention 1. The description of the "presence or absence of rust in the cycle corrosion test" and "adhesion after the cycle corrosion test" in the corrosion-resistant adhesive tape according to the invention 1 is applicable to the corrosion-resistant adhesive tape according to the invention 3, and the description thereof is omitted.

From the viewpoint of improvement in weather resistance, the anticorrosive adhesive tape according to invention 3 is preferably one having a gloss retention of 80% or more after 500 hours of accelerated weather resistance test according to cycle A in JIS K5600-7-7. The description of the "gloss retention in accelerated weathering test" in the anticorrosive adhesive tape according to invention 1 is applicable to the anticorrosive adhesive tape according to invention 3, and the description thereof is omitted.

< substrate >

The substrate of the etching resist adhesive tape according to claim 3 may be the substrate described in the etching resist adhesive tape according to claim 1, without any particular limitation. The description of the "material used for the substrate" and "thickness of the substrate" in the etching resist tape according to the invention 1 is applicable to the etching resist tape according to the invention 3, and the description thereof is omitted.

< adhesive layer >)

The etching resist adhesive tape according to claim 3 includes an adhesive layer on at least one surface of a substrate. The pressure-sensitive adhesive layer is similar to the pressure-sensitive adhesive layer in the etching-resistant pressure-sensitive adhesive tape according to the invention 1, and therefore, description thereof is omitted.

Structure of adhesive tape for anticorrosion

As shown in fig. 2, the etching resist adhesive tape 10 according to invention 3 is preferably a single-sided adhesive tape having a base material 12 and an adhesive layer 11 provided on one side of the base material 12. Thereby, the adhesive layer 11 can be protected by the base material 12.

The anti-corrosive adhesive tape of each figure is used by adhering the surface 11A of the adhesive layer 11 to an adherend as an adhesive surface.

Although not shown, the pressure-sensitive adhesive tape for corrosion prevention may be a double-sided pressure-sensitive adhesive tape provided with a base material and pressure-sensitive adhesive layers on both sides of the base material.

As described above, the adhesive layer in the present invention may not contain a metal having a lower potential than iron. In this case, in order to improve the corrosion resistance of the corrosion-resistant adhesive tape 10, as shown in fig. 4, the corrosion-resistant adhesive tape 10 preferably further includes a metal layer 13 between the base material 12 and the adhesive layer 11, and the metal layer 13 is a layer of a metal having a lower potential than iron. The metal having a lower potential than iron is not particularly limited, but the metal layer 13 is more preferably a zinc layer. Specifically, the metal layer 13 may be bonded to the base material 12 by an adhesive or the like, or may be formed on the base material 12 by sputtering, vacuum deposition, or the like. The metal layer 13 may be a metal film formed by coating the surface of the pressure-sensitive adhesive layer 11 with a metal by sputtering, vacuum evaporation, or the like.

The metal layer 13 is directly formed on the pressure-sensitive adhesive layer 11 in such a manner as to be sandwiched between the base material 12 and the pressure-sensitive adhesive layer 11. That is, the metal constituting the metal layer 13, which has a lower potential than iron, is in contact with the adhesive layer 11. In this way, if a metal having a potential lower than that of iron is in contact with the adhesive layer 11, electrons emitted when ionization is performed can easily move to the adhesive layer 11, and thus the corrosion resistance of the corrosion-resistant adhesive tape 10 is improved. In this case, from the viewpoint of the corrosion resistance of the corrosion-resistant adhesive tape 10, the adhesive layer 11 preferably contains a conductive material other than a metal having a lower potential than iron.

The thickness of the metal layer 13 is preferably 2.5 μm or more. If the thickness of the metal layer 13 is 2.5 μm or more, electrons obtained by ionization of the metal in the metal layer 13 can be sufficiently supplied to the metal layer 13, and the sufficient corrosion resistance of the corrosion-resistant adhesive tape 10 can be maintained. The thickness of the metal layer 13 is more preferably 5 μm or more from the viewpoint of improving the corrosion resistance of the pressure-sensitive adhesive tape 10 for corrosion resistance. Further, the thickness of the metal layer 13 is preferably 200 μm or less, more preferably 100 μm or less, from the viewpoints of ensuring the flexibility of the pressure-sensitive adhesive tape 10 for corrosion prevention, making the workability of the pressure-sensitive adhesive tape 10 for corrosion prevention good, and making it easy to adhere the pressure-sensitive adhesive tape for corrosion prevention to an adherend having a complicated shape.

The pressure-sensitive adhesive tape for corrosion prevention of the invention 3 can be produced by attaching a release sheet to the surface of the pressure-sensitive adhesive layer. The release sheet is preferably released from the pressure-sensitive adhesive layer before the use of the etching resist pressure-sensitive adhesive tape, and the pressure-sensitive adhesive layer is exposed and bonded to the adherend through the exposed pressure-sensitive adhesive layer. More specifically, the release sheet is preferably attached to the surface 11A, which is the surface opposite to the surface on which the base material 12 or the metal layer 13 is provided, of the surfaces of the pressure-sensitive adhesive layer.

The release sheet preferably uses a resin film, but the surface to be bonded to the pressure-sensitive adhesive layer is preferably a release-treated surface subjected to release treatment with a silicone release agent or the like.

[ use of adhesive tape for Corrosion prevention ]

The pressure-sensitive adhesive tape for corrosion prevention according to claim 3 is used for adhering various adherends and for corrosion prevention of the adherends. The pressure-sensitive adhesive tape for corrosion prevention according to an embodiment of the present invention is preferably used by adhering to the surface of an adherend made of various metal materials because of excellent adhesion and corrosion resistance. As the metal material, a metal material containing at least 1 selected from iron and an alloy containing iron is preferable. Specific examples of the iron-containing alloy include various steels such as nickel-chromium steel, nickel-chromium-molybdenum steel, chromium-molybdenum steel, alloy steel such as manganese steel, and carbon steel.

The anticorrosive pressure-sensitive adhesive tape according to claim 3 is preferably used for an adherend having a complicated shape. Specific examples of the adherend include an adherend having irregularities, and examples thereof include a member having a welded portion formed by joining 2 members by welding. In the member having the welded portion, the welded portion becomes a convex portion. Examples of the adherend having a welded portion include welded pipes. The welded pipe had a welded joint portion where 2 pipes were connected. The pressure-sensitive adhesive tape for corrosion prevention is preferably applied to the adherend having the welded portion so as to cover the welded portion.

In general, even if an anticorrosive paint is applied to a welded portion, the film may drip until it is cured, and thus the film thickness after curing may be thinner than necessary, cracks may be generated, and the torturous area may be exposed to cause relatively easy rusting. In addition, the adhesive tape for corrosion prevention of the present invention can exhibit excellent corrosion resistance because it can ensure high adhesion and follow-up properties without cracking even when it is attached to an adherend having a complicated shape such as a welded part.

The pressure-sensitive adhesive tape for corrosion prevention according to the invention 3 can be bonded to various adherends by pressure-bonding the pressure-sensitive adhesive tape to the adherends while heating the pressure-sensitive adhesive tape to, for example, 90 to 150℃and preferably 90 to 130 ℃. By adhering to the adherend while heating, the adhesive can be adhered to the adherend with higher adhesion and follow-up properties, and high corrosion resistance can be easily ensured. The pressure-sensitive adhesive tape may be heated by a known heating device such as an industrial dryer.

The adhesive tape for corrosion prevention of the present invention can be used for repair purposes. The repair application is to perform an anticorrosive treatment on a metal material such as a steel material constituting an existing structure such as a bridge, a pylon, a viaduct, a tank, a factory, a bridge pier, or a piping.

Examples

The present invention will be described in further detail with reference to examples, but the present invention is not limited to these examples.

[ evaluation method ]

In examples and comparative examples, the pressure-sensitive adhesive tapes for corrosion prevention were evaluated by the following evaluation methods.

< presence or absence of rust in cycle Corrosion test >

As described in the specification, in JIS K5600-7-9 (paint general protocol-7 th part: paint coating durability-9 th part: coating method-water spray coating/drying/wetting (paint general test method-7 th part: long-term durability of coating film-9 th part: cyclic corrosion test method-brine spray/drying/wetting), the presence or absence of rust generation in cut-in portions was visually confirmed by the cycle D).

(adhesive force)

1. Preparation of the sample

The adhesive tapes for corrosion protection (width 25mm, length 100 mm) of each example and comparative example were attached to SUS plates (width 50mm, length 125 mm), adhesive force evaluation samples were prepared, and initial adhesive forces (adhesive forces before test) were measured using the adhesive force evaluation samples.

Further, using a sample for evaluating adhesive force prepared in the same manner as above, a salt spray test was performed based on cycle D of appendix 1 of JIS K5600-7-9. The test was run for 28 cycles (total 168 hours). Further, the adhesive force was measured on the adhesive force evaluation sample after the salt spray test.

2. Determination of adhesion

The adhesive force was measured using the adhesive force evaluation samples before and after the test, as follows.

Each of the samples for evaluating the adhesive force was fixed to a tensile tester (product name, dupont) a chuck for manufacturing a "Teflon universal material tester". Then, the pressure-sensitive adhesive tape for corrosion prevention was stretched at 180℃and a speed of 300 mm/min at 60mm or more under an environment of 50RH% at 23℃to record the average value of the intervals of the load (N) detected by the load cell as the adhesive force.

(storage modulus)

The storage modulus at 23℃of the adhesive layer of the pressure-sensitive adhesive tape for corrosion prevention was measured using a dynamic viscoelasticity measuring device (product name "DVA-200" manufactured by Soy Seiyaku Co., ltd.) in shear mode: 10Hz, strain amount: 0.1%, temperature range: -100 ℃, and the temperature rising speed is as follows: and (3) measuring the dynamic viscoelasticity spectrum at the condition of 10 ℃ per minute.

< difference in tensile load >

The base materials used in each example and comparative example were measured for a tensile load in the case of 2.5% stretching and a tensile load in the case of 0.5% stretching by using a tensile tester, respectively, and the difference between the two was calculated. The measurement was performed in each of the MD direction and the TD direction, and the difference between the tensile load when 2.5% stretching was performed and the tensile load when 0.5% stretching was performed was calculated for each direction. The difference between the calculated tensile loads in the MD and TD is set to be the larger value.

< elongation at break in tension >

The substrates used for the production of the anticorrosive adhesive tapes of examples and comparative examples were subjected to tensile tests in the respective MD and TD directions using a tensile tester (tikoku d/dud universal material test machine) and the tensile elongation at break was calculated by the following equation.

Elongation at break (%) = (L-L) ₀ )/L ₀ ×100

Where L is the length of the sample at break, L ₀ The length of the specimen before the tensile test.

The value of the smaller of the calculated tensile elongation at break in the MD and TD is defined as the tensile elongation at break of the film.

The conditions for measuring the tensile load and the tensile elongation at break are as follows.

Size and shape of the substrate: elongated shape with width of 10mm x length of 80mm

Distance between chucks: 50mm

Stretching speed: 300 mm/min

< Elmendorf tear Strength >)

The measurement was carried out by the Elmendorf tear method in accordance with JIS K7128-2 (1998). The measurement was performed on both MD and TD, and the smaller value was taken as the elmendorf tear strength (N) of the substrate.

< practical evaluation on exfoliation >)

The etching resist tapes (width 25mm, length 100 mm) of each example and comparative example were attached to SUS plates (width 50mm, length 125 mm), and cured at 23℃for 3 days to prepare test pieces for peeling evaluation. Water was sprayed from a spray position obliquely above the etching resist adhesive tape in the peeling evaluation specimen toward the longitudinal end side of the etching resist adhesive tape under a water pressure of 8MPa for 5 minutes. The position (ejection position) of the water jet was a position where the angle between the line connecting the ejection position and the central portion of the end portion of the etching resist adhesive tape and the SUS plate became 30 ℃ and a position directly above a point 5cm away from the central portion of the end portion of the etching resist adhesive tape in the horizontal direction.

The distance by which the anticorrosive adhesive tape was peeled off after water spraying was measured, and evaluated based on the following criteria.

A.peel-off distance is 0mm or more and less than 15mm

The distance of peeling of B is 15mm or more and less than 25mm

The distance of C.peel-off is 25mm or more

< weather resistance (gloss retention) >

The anticorrosive adhesive tapes (width 25mm, length 100 mm) of the examples and comparative examples were attached, and the specular gloss was measured on the surface of the tapes from the substrate side by a gloss meter (manufactured by horiba corporation, product name: IG-340). Specular gloss measurements were carried out in accordance with JIS K5600-4-7 using a 60℃gloss meter. The specular gloss obtained by the measurement at this time was set to specular gloss a. Then, with respect to the tape, an accelerated weather resistance test according to cycle A in JIS K5600-7-7 was conducted for 500 hours. After the accelerated weathering test was performed, the specular gloss of the base material of the tape was measured by the same method as that performed before the test was performed. The specular gloss obtained by measurement after the test was set as specular gloss B.

The gloss retention of the base material of the tape was calculated from the 2 specular gloss obtained in the above manner. The expression for determining the gloss retention is as follows.

Gloss retention (%) = (specular gloss B/specular gloss a) ×100

A.gloss retention of 90% or more

A B.gloss retention of 80% or more and less than 90%

C.gloss retention of less than 80%

Practical evaluation of convex portion following Property

The following steps 1 to 4 were used to evaluate the convex portion following property.

1. As shown in fig. 5, the etching resist adhesive tape 10 was attached to the surface 20A to be attached of the L-shaped SUS plate 20 so that the height h and width t of the pitch angle became 2mm.

2. The scraping member is pressed against a portion of the etching resist adhesive tape 10 which is not adhered to the L-shaped SUS plate 20.

3. After the pressing of 2, the height h was measured, and the occurrence of cracking of the pressure-sensitive adhesive tape 10 was visually confirmed. In addition, when the pressure is applied and the pressure-sensitive adhesive tape 10 is cracked, the height is set to h=2mm.

4. Based on the measured value of the height h obtained in the above 3, the protrusion following property of the pressure-sensitive adhesive tape 10 for corrosion prevention was evaluated according to the following criteria.

A.multidot.height h is 0mm, and the adhesive tape 10 for corrosion prevention does not crack.

The height h is greater than 0mm, or the etching resist adhesive tape 10 is cracked.

< comprehensive evaluation >)

Based on the above-described "peeling", "weather resistance", "convex portion following property" 3 evaluations, comprehensive evaluations were performed as follows.

All of the S.3 evaluations were "B" or more.

A- "peeling" was evaluated as "B" or more, and 1 of the remaining evaluations was "C".

B- "flaking" was rated as "B" or more, and the remaining 2 were rated as "C".

Evaluation of C.cndot. "flaking" was "C".

< substrate used >

As the base material, the following resin films were used.

Polyolefin resin film: the product name "Lavenn NEXT-S", manufactured by Kohl co Co., ltd., for local area water and fiber industry, respectively

Polyolefin resin film: the product name "Chandu compound CP-WGF", manufactured by Kohl co., ltd., wold., kogyo Co., ltd.)

Polyolefin resin film: the product name "d/d", manufactured by industrial co

Monolayer film of Low Density Polyethylene (LDPE): the product name "seta sleeve PE sleeve" is produced by water molding industry Co., ltd

Fluorine-based film: product name "50NS", manufactured by AGC Co., ltd

Acrylic resin film: product name "mountain hose MBS121E", mitsubishi chemical corporation

Acrylic resin film: the product name "uronate HBS005", manufactured by mitsubishi corporation

Acrylic resin film: the product name "uronate HBS006", mitsubishi chemical corporation

Polyethylene terephthalate film (PET)

As the other part of the resin film, a substance having a paint film on the surface is used. The presence or absence of the paint film is shown in the table.

Example 1

The adhesive compositions were prepared according to the compounding described in table 1. The adhesive composition was purged with nitrogen gas to remove dissolved oxygen. Next, the adhesive composition is coated on the film.

In this state, the irradiation intensity with ultraviolet light was 5mW/cm ² The lamp intensity of the chemical lamp was adjusted and ultraviolet light was irradiated from one side for 15 minutes to obtain an adhesive tape for corrosion prevention, and various evaluations were performed. The results are shown in table 1.

Examples 2 to 27 and comparative examples 1 to 2

An anticorrosive adhesive tape was obtained in the same manner as in example 1, except that the adhesive compositions were prepared by blending as shown in tables 1 to 3 and the films as shown in tables 1 to 3 were coated with the adhesive compositions. The results of the various evaluations are shown in tables 1 to 3.

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The components in tables 1 to 3 are as follows.

Olefin polymer: hydrogenated polybutadiene having a (meth) acryloyl group at one end, manufactured by Kyowa corporation under the trade name "L-1253

Tackifying resin 1: trade name "ALL コ N P140", hydrogenated Petroleum resin, softening Point 140 ℃ manufactured by Kagaku Kogyo Co., ltd

Tackifying resin 2: trade name "ALL コ N P100", hydrogenated Petroleum resin manufactured by Kagaku Kogyo Co., ltd., softening point 100 DEG C

Microparticles: trade name "Seal Z-27", glass ball manufactured by Tohai industry Co., ltd

Crosslinking agent: trade name "TEAI-1000", manufactured by Nippon Caesada Co., ltd

Polymerization initiator: 2, 2-dimethoxy-2-phenylacetophenone

Zinc particles: trade name "No. 40", manufactured by saku chemical industry co., ltd., average particle size: 50 μm

Carbon Nanotubes (CNT): JEIO Co., ltd., product name "JECTOUBE 8A", average diameter of 6 to 9nm, average length of 100 to 200 μm

Carbon black: artificial graphite powder, amorphous fiber, trade name "AT-NO.15S", average particle diameter 13 μm

Dispersant: brand name "pbx-L", manufactured by water chemical industry corporation, polyvinyl butyral resin

The anticorrosive pressure-sensitive adhesive tapes of examples 1 to 27 (invention 1) which did not rust in the cyclic corrosion test and had an adhesive force of 20N/25mm or more after the cyclic corrosion test were excellent in corrosion resistance, and further maintained high adhesive force for a long period of time. In addition, good results were obtained with respect to practical evaluation of exfoliation.

The anticorrosive adhesive tapes of examples 1 to 26 (invention 2) having a gloss retention of 80% or more after the accelerated weathering test and an adhesive force of 20N/25mm or more after the cyclic corrosion test were not degraded even after the irradiation of ultraviolet rays for a long period of time, and maintained high adhesive force and good appearance.

The anticorrosive adhesive tapes of examples 1 to 12 (invention 3) which had a difference between a tensile load at 2.5% elongation and a tensile load at 0.5% elongation of 30N/24mm or less and had a tensile elongation at break of 100% or more had a follow-up property with respect to the adherend surface, and could be bonded to the adherend surface having a complicated shape without cracking.

Description of symbols

10. Corrosion-resistant adhesive tape

11. Adhesive layer

12. Substrate material

13. Metal layer

20L-shaped SUS plate

20A stuck surface

h height

t width.

Claims (18)

1. An anti-corrosive adhesive tape comprising an adhesive layer, wherein rust does not occur in a cyclic corrosion test according to cycle D in JIS K5600-7-9, and the adhesive force after the cyclic corrosion test is 20N/25mm or more.

2. The pressure-sensitive adhesive tape for corrosion prevention according to claim 1, further comprising a substrate, wherein the pressure-sensitive adhesive layer is provided on one surface of the substrate.

3. The adhesive tape for corrosion prevention according to claim 2, wherein the substrate has a gloss retention of 80% or more after the accelerated weather resistance test according to cycle A in JIS K5600-7-7 is carried out for 500 hours.

4. The adhesive tape for corrosion prevention according to claim 2 or 3, wherein a difference between a tensile load of the substrate when subjected to 2.5% elongation and a tensile load of the substrate when subjected to 0.5% elongation is 30N/24mm or less, and a tensile elongation at break is 100% or more.

5. An anti-corrosive adhesive tape comprising a base material and an adhesive layer provided on one surface of the base material,

the substrate has a gloss retention of 80% or more after the accelerated weathering test according to cycle A in JIS K5600-7-7 for 500 hours and an adhesion of 20N/25mm or more after the cyclic corrosion test according to cycle D in JIS K5600-7-9.

6. An anti-corrosive adhesive tape comprising a base material and an adhesive layer provided on at least one surface of the base material,

the difference between the tensile load of the base material when subjected to 2.5% elongation and the tensile load when subjected to 0.5% elongation is 30N/24mm or less, and the tensile elongation at break is 100% or more.

7. The adhesive tape for corrosion prevention according to any one of claims 2 to 6, wherein the substrate has an elmendorf tear strength of 0.6N or more as measured by the elmendorf tear method according to JIS K7128-2 in 1998.

8. The adhesive tape for corrosion prevention according to any one of claims 2 to 7, wherein the substrate is a resin film having a coating film on a surface thereof.

9. The adhesive tape for corrosion prevention according to any one of claims 2 to 8, wherein the substrate is at least 1 selected from an acrylic film and a fluorine film.

10. The adhesive tape for corrosion prevention according to any one of claims 1 to 9, wherein the thickness of the adhesive layer is 25 μm or more.

11. The adhesive tape for corrosion prevention according to any one of claims 1 to 10, wherein the adhesive layer contains a metal having a lower potential than iron.

12. The adhesive tape for corrosion prevention according to claim 11, wherein the metal having a lower potential than iron is zinc.

13. The adhesive tape for corrosion prevention according to claim 11 or 12, wherein the adhesive layer contains a conductive material other than the metal having a lower potential than iron.

14. The adhesive tape for corrosion prevention according to claim 13, wherein the conductive material is carbon nanotubes.

15. The adhesive tape for corrosion prevention according to any one of claims 1 to 14, wherein the adhesive layer is formed by an acrylic adhesive.

16. The adhesive tape for corrosion prevention according to claim 1, comprising the adhesive layer and a metal layer provided on one surface of the adhesive layer, wherein the metal layer is a layer of a metal having a lower potential than iron.

17. The pressure-sensitive adhesive tape for corrosion prevention according to any one of claims 2 to 16, wherein a metal layer is provided between the base material and the pressure-sensitive adhesive layer, and the metal layer is a layer of a metal having a lower potential than iron.

18. The adhesive tape for corrosion prevention according to claim 16 or 17, wherein the metal layer is a layer of zinc.