WO2017098649A1 - Adhesive tape for retention - Google Patents

Abstract

Disclosed is an adhesive tape for retention which includes: a laminated substrate 1 having a metallic foil 1a and a resin film 1b; and an adhesive layer 2 provided at least on the side of the metallic foil 1a of the laminated substrate 1. The adhesive tape for retention has excellent flame resistance, and curl resistance which passes, for example, the FMVSS-302 flammability test, and has other excellent properties (adhesiveness, shock resistance, tear resistance, curl resistance, unwinding properties, workability, etc.).

Description

Holding adhesive tape

The present invention relates to a holding pressure-sensitive adhesive tape that is useful for holding and fixing vehicle parts such as a harness to a site such as a ceiling.

In recent years, electronic control of vehicles (particularly automobiles) has progressed, and many electric wires are installed in various places in the vehicle. For example, in an automobile manufacturing process, efficiency is achieved by using a harness in which electric wires and connection connectors are preliminarily assembled. The harness is held and fixed to a part such as the back of the ceiling of the automobile or under the floor panel using an adhesive tape or a clip. Furthermore, harnesses are sometimes used in parts such as bodies, bumpers, door trims, door mirrors, instrument panels, tail lamps, and various sensors, and countless wires are stretched around the vehicle.

When fixing a harness or an electric wire with a clip, it is necessary to provide a through-hole for passing the arm part of the clip and metal fittings in the member, so there are disadvantages in that the strength of the member is reduced and the machining process is increased. Furthermore, due to the additional equipment of optional parts (back monitor, radar brake, false start prevention function, electric mirror, anti-theft device, etc.), the wiring pattern of electric wires becomes various, and the number of through holes increases accordingly. . Such an increase in the number of through holes causes difficulty in strength design and complicates the machining process. On the other hand, when fixing a harness or an electric wire with an adhesive tape, processing to a member such as through-hole processing is unnecessary, and various wiring patterns can be easily handled. Therefore, in recent years, the amount of adhesive tape used per car is increasing.

Generally, various members used inside automobiles are required to have flame retardancy from the viewpoint of ensuring safety. And recently, with the increase in the amount of adhesive tape used, the flame resistance of the adhesive tape has been demanded. Specifically, the flame retardancy is flame retardance that conforms to, for example, the FMVSS-302 combustion test, which is a safety standard for US federal automobile interior components.

In the FMVSS-302 combustion test, the direction in which the flame is applied to the test piece (adhesive tape) is not specified. However, the present inventors prefer that the adhesive tape used for vehicles such as automobiles has excellent flame retardancy against flames from any direction on the front side (vehicle inside) and the back side (vehicle outside). I think. For example, there are various cases such as fire due to short circuit inside the wire, fire due to carelessness of the passenger such as cigarette fire, fire caused by external causes such as engine failure or arson, etc., both from the front and back side of the adhesive tape This is because there is a possibility of fire.

As a method for imparting flame retardancy to the adhesive tape, for example, there is a method of adding flame retardant particles to the adhesive of the adhesive tape. However, in this method, the adhesive strength tends to decrease, and the adhesive tape may be peeled off without being able to withstand the weight of a member such as an electric wire or a tube, and may fall off. Therefore, currently, an adhesive tape using a metal foil is used. The metal foil itself is nonflammable and exhibits cooling and extinguishing effects due to heat transfer.

For example, Patent Document 1 discloses an adhesive sheet for fixing a wire harness. The base material of this pressure-sensitive adhesive sheet is a laminate of a soft metal foil and a foamed resin layer, and the flexibility of the foamed resin layer improves the followability to the uneven surface shape of the automobile ceiling material. However, since the foamed resin layer is flexible, a sufficient pressure cannot be applied to the adherend, and the adhesive force tends to decrease.

In the example of Patent Document 1, an FMVSS-302 combustion test is performed for flame retardancy evaluation. Specifically, the test was conducted with the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive sheet facing down, that is, in contact with the back side of the pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive sheets of Examples 1 to 6 had flame retardancy (self-extinguishing). Evaluating. However, according to the knowledge of the present inventors, when performing a test with the metal foil surface facing down instead of the pressure-sensitive adhesive layer surface of these pressure-sensitive adhesive sheets, that is, in contact with the front side of the pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet spreads, There is a risk of not meeting the acceptance criteria for flame retardancy. This is considered to be due to scattering of the surface carbonized layer (char) caused by combustion of the pressure-sensitive adhesive layer or the foamed layer. That is, when a flame is applied from the bottom to the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive sheet as in the test of Patent Document 1, a surface carbonized layer (char) is generated on the lower surface of the sheet due to combustion of the pressure-sensitive adhesive layer or the foam layer. This exerts an oxygen blocking action and exhibits self-extinguishing properties. However, conversely, if a flame is applied to the metal foil side of the pressure-sensitive adhesive sheet from the bottom, a char surface layer (char) is generated on the upper surface of the pressure-sensitive adhesive sheet. Therefore, it is presumed that the oxygen-blocking action is lowered and the self-extinguishing property is hardly exhibited. That is, it is considered that the pressure-sensitive adhesive sheet of Patent Document 1 has insufficient flame retardancy when it is in contact with the front side (metal foil side).

Patent Document 2 discloses an adhesive sheet in which an adhesive layer is provided on a soft metal foil. However, since this pressure-sensitive adhesive sheet is a sheet composed only of a soft metal foil and a pressure-sensitive adhesive layer, it is easily broken. Specifically, for example, there is a possibility that the metal foil may be torn due to vibration generated during transportation or processing of parts in an automobile assembly process, or impact generated during travel of a completed automobile. Furthermore, if burrs are generated at the edge of the adhesive sheet, the burrs are sharp and the operator may be injured. In addition, since the soft metal foil has a large plastic deformation, curling is likely to occur when the pressure-sensitive adhesive sheet is rewound, and it is relatively difficult to attach to the adherend. Accordingly, release paper is laminated in advance on such a commercial product of this type, thereby eliminating the curling problem. However, the use of release paper is not preferable in terms of workability and cost.

When holding and fixing parts using adhesive tape, it is necessary to cut the adhesive tape to a predetermined size in advance. Therefore, in the case of an adhesive tape in which a separator such as release paper is bonded to the adhesive layer, a process of attaching the release paper to the adhesive tape, a cutting process with a cutting machine, and a punching process are necessary, and the work becomes complicated. . Furthermore, since a mold for punching a predetermined dimension is required, it is not preferable from the viewpoint of manufacturing cost, and it is not preferable from the viewpoint of workability because it is necessary to peel off the release paper when using the adhesive tape. Further, the peeled release paper becomes a large amount of garbage.

In the case of a wound adhesive tape that does not use release paper, the wound adhesive tape is cut to a desired length using a tape dispenser, so the base material of the adhesive tape is required. On the other hand, if the metal foil of the base material is made thick in order to hold the waist, the base material is easily wrinkled, and curling occurs during rewinding, resulting in poor workability.

Patent Document 3 discloses a flame-resistant sheet material provided with a thin metal layer and a synthetic resin thin layer, and a flame-resistant sheet material further provided with an adhesive layer on the metal thin layer side. However, the non-ignitable sheet material provided with the pressure-sensitive adhesive layer of Patent Document 3 is stuck on a plate material such as plywood or particle board, a building material such as a wall, firewood, or floor, and it is difficult for combustion to occur even if the cigarette is pressed. This is a sheet intended for this purpose. Therefore, compared with the pressure-sensitive adhesive sheet for holding vehicle parts such as harnesses as in Patent Documents 1 and 2, its use is completely different. Further, the flame ignitability in Patent Document 3 is a characteristic that assumes a case of simply pressing a cigarette, and is not a strict standard like the flame retardant test of the automotive interior member safety standard (FMVSS-302) in Patent Document 1. . In addition, the synthetic resin thin layer of the hardly ignitable sheet material of Patent Document 3 is a layer mainly provided to widen the range of design selection, and this synthetic resin thin layer and the high standard such as the FMVSS-302 combustion test are used. Patent Document 3 does not discuss any correlation with flame retardancy.

JP 2006-206820 A JP 2006-96856 A Japanese Patent Laid-Open No. 10-159290

An object of the present invention is to provide a pressure-sensitive adhesive tape for holding that is particularly excellent in flame retardancy and curl resistance and other properties.

As a result of intensive studies to solve the above-mentioned problems, the present inventors did not use a metal foil alone as a base material, but a laminated base material having a metal foil and a resin film, the resin film side being the front side of the adhesive tape The present inventors have found that it is very effective to use such a laminated base material to complete the present invention.

That is, the present invention is a holding pressure-sensitive adhesive tape having a laminated base material having a metal foil and a resin film, and an adhesive layer provided on at least the metal foil side of the laminated base material.

The adhesive tape of the present invention is particularly excellent in flame retardancy and curling resistance. Moreover, in the FMVSS-302 combustion test of the safety standard of the US federal automobile interior member, it can also have high flame retardance that passes the flame contact from either the front side or the back side of the adhesive tape. Furthermore, it can also have excellent properties in adhesiveness, impact resistance, tear resistance, rewinding property, workability, and the like. Therefore, it is useful for various uses in fields where such characteristics are required, for example, for holding and fixing vehicle parts such as harnesses on a site such as a ceiling.

It is typical sectional drawing which shows one Embodiment of the adhesive tape of this invention. It is the typical top view for demonstrating the impact resistance evaluation method in an Example and a comparative example, and its sectional drawing. It is typical sectional drawing for demonstrating the evaluation method of the curl resistance in an Example and a comparative example.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the holding adhesive tape of the present invention. In this embodiment, the pressure-sensitive adhesive tape includes a laminated base material 1 having a metal foil 1a and a resin film 1b, and a pressure-sensitive adhesive layer 2 provided on the metal foil 1a side of the laminated base material 1. The laminated substrate 1 is a laminated body in which a metal foil 1a and a resin film 1b are bonded through an adhesive layer 1c. Further, a release layer 3 is formed on the resin film 1 a of the laminated substrate 1.

The pressure-sensitive adhesive tape shown in FIG. 1 is a preferred embodiment of the present invention, but the present invention is not limited to this. For example, the pressure-sensitive adhesive tape of the present invention does not necessarily have to be formed with the release layer 3 and does not necessarily have the adhesive layer 1c. For example, the resin film 1b can be formed by directly applying and curing a desired resin material on the metal foil 1a.

For the purpose of improving the adhesion between the metal foil 1a and the pressure-sensitive adhesive layer 2, a desired resin layer may be provided between the metal foil 1a and the pressure-sensitive adhesive layer 2. Furthermore, although the adhesive tape shown in FIG. 1 is a single-sided adhesive tape, a double-sided adhesive tape may be sufficient. In the case of a double-sided pressure-sensitive adhesive tape, the release layer 3 is not necessary. For example, a double-sided pressure-sensitive adhesive tape can be obtained by providing a pressure-sensitive adhesive layer on the resin film 1 b side of the laminated substrate 1.

[Laminated substrate 1]
Although the metal foil 1a which comprises a part of the laminated base material 1 is not specifically limited, The soft metal foil which is excellent in heat conductivity is preferable. Specific examples of the metal include silver, copper, aluminum, and nickel. Among these, aluminum is preferable from the viewpoints of resistance to discoloration and deterioration and cost. The thickness of the metal foil is preferably 7 to 130 μm, more preferably 12 to 50 μm, and particularly preferably 20 to 30 μm.

The resin film 1b constituting a part of the laminated base material 1 is not particularly limited, but a film made of a resin such as a plastic having a high oxygen index, which is an index of difficulty in burning, is preferable. Specific examples of the plastic include cross-linked polyethylene, polycarbonate, polyamide, polystyrene, polyester, polypropylene, polyethylene, acrylic resin, and polyacetal. Among them, polyester is preferable from the viewpoint of waist strength and economical point. The thickness of the resin film 1b is preferably 4 to 250 μm, more preferably 12 to 125 μm, and particularly preferably 25 to 75 μm. In order to improve the flame retardancy, a known flame retardant can also be added to the resin film 2.

In the present invention, since the laminated base material 1 has the resin film 1b, the impact resistance is improved, and for example, the adhesive tape can be prevented from being broken by a strong impact such as vehicle running. Furthermore, compared with the base material which consists only of metal foil, curl resistance improves, and since the resin film 1b protects the sharp corner of the cross section of the metal foil 1a, an operator's injury can be prevented.

[Adhesive layer 2]
The pressure-sensitive adhesive used for the pressure-sensitive adhesive layer 2 is not particularly limited. Specific examples include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, and the like. Among these, an acrylic pressure-sensitive adhesive is preferable because it is inexpensive and has excellent heat resistance. The thickness of the pressure-sensitive adhesive layer 2 is not particularly limited, but is preferably 10 to 140 μm, more preferably 30 to 100 μm, and particularly preferably 40 to 80 μm.

In the pressure-sensitive adhesive 2, flame retardancy and other known additives can be added within a range not impairing the object of the present invention.

[Release layer 3]
The release layer 3 can be formed by applying a release agent (back treatment) on the front side of the adhesive tape. By forming this release layer 1, curling when the tape is rewound can be prevented and workability is improved. The release agent is not particularly limited. Specific examples include silicone release agents, long-chain alkyl release agents, fluorine release agents, and wax release agents. Among these, a silicone release agent is preferable from the viewpoint of easy peeling. Two or more release agents may be combined. When a mold release agent contains a functional group, you may improve the adhesiveness to a base material using the hardening | curing agent which reacts with this. The amount of the release agent applied is preferably 0.005 to 1 g / m ² , more preferably 0.01 to 0.5 g / m ² , and particularly preferably 0.05 to 0.3 g / m ² .

[Adhesive tape]
The holding pressure-sensitive adhesive tape of the present invention includes the laminated base material 1 having the metal foil 1a and the resin film 1b described above, and the pressure-sensitive adhesive layer 2 provided on at least the metal foil 1a side of the laminated base material 1. By using the metal foil 1a as an intermediate layer, the flame is divided into the resin film 1b side and the pressure-sensitive adhesive layer 2 side even if the flame comes into contact. Therefore, in the FMVSS-302 combustion test, the flame contact from any side of the test piece In contrast, it is possible to obtain a holding pressure-sensitive adhesive tape excellent in flame retardancy that can pass.

In the present invention, by adjusting the ratio of the thickness of the metal foil 1a and the thickness of the resin film 1b, it is possible to impart very excellent flame retardancy even when the metal foil 1a is thin. . Specifically, when the thickness of the metal foil 1a is less than 50 μm, the thickness (Mt) of the metal foil 1a and the thickness (Ft) of the resin film 1b preferably satisfy the following formula (1).
Ft / Mt ≦ 2 (1)

When the above formula (1) is satisfied, even if the metal foil 1a is thin (less than 50 μm), in the FMVSS-302 combustion test of the safety standard for US automobile interior parts, flame contact to the front side of the adhesive tape And the adhesive tape which has the high flame retardance which passes in any case of the flame contact to a back side is obtained. Specifically, the acceptance criteria of the FMVSS-302 combustion test are: a) the combustion distance is within 51 mm and the combustion time is within 60 seconds, or b) the combustion speed divided by the combustion time is 102 mm / min. It conforms to one of the following.

When the back side of the pressure-sensitive adhesive tape of the present invention is in contact with the flame, a surface carbonized layer (char) is generated by the combustion of the pressure-sensitive adhesive layer 2, which exerts an oxygen blocking action and exhibits self-extinguishing properties. On the other hand, when the front side is in contact with the flame, a surface carbonized layer (char) is generated by the combustion of the resin film 1b, and this exerts an oxygen blocking action and expresses self-extinguishing properties. In other words, the flame retardancy is excellent in flame contact from any surface. On the other hand, for example, a conventional adhesive tape with a metal foil on the front side causes a carbonized surface (char) to form on the upper side of the pressure-sensitive adhesive sheet when it comes in contact with the front side (metal foil side) down, so an upward air flow accompanying combustion As a result, the char is easily scattered, the oxygen blocking action is lowered, and the self-extinguishing property is hardly exhibited.

The pressure-sensitive adhesive tape of the present invention is used for holding purposes. Specifically, it is preferably used for holding vehicle parts. For example, it is very useful for applications in which vehicle parts such as harnesses are held and fixed to a site such as a ceiling.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the following description, “part” means “part by mass”.

[Example 1]
A 12 μm thick soft aluminum foil and a 12 μm thick polyester film (PET film) were bonded together with an adhesive to obtain a laminated substrate (metal foil + adhesive layer + resin film). Next, a silicone coating agent (manufactured by Matsumoto Fine Chemical Co., Ltd., OlgaTix (registered trademark) SIC-434) as a release agent is applied to the polyester film (resin film) surface of the laminated substrate so that the coating amount after drying is 0.00. A release layer was formed by coating so as to be 1 g / m ² .

2.5 parts of an isocyanate-based crosslinking agent (trade name BHS8515, manufactured by Toyochem Co., Ltd.) was mixed with 100 parts of an acrylic adhesive (trade name BPS6080TFK, manufactured by Toyochem Co., Ltd.) to obtain a mixed solution for the adhesive layer. This mixed solution was applied to the aluminum foil (metal foil) surface of the laminated substrate and dried to form a pressure-sensitive adhesive layer having a thickness of 60 μm to obtain a pressure-sensitive adhesive tape.

[Example 2]
An adhesive tape was produced in the same manner as in Example 1 except that the thickness of the resin film was changed to 20 μm.

[Example 3]
An adhesive tape was produced in the same manner as in Example 2 except that a stretched polypropylene film (OPP film) having a thickness of 20 μm was used as the resin film.

[Examples 4, 6 and 7]
An adhesive tape was produced in the same manner as in Example 2 except that the thickness of the resin film and / or the thickness of the metal foil was changed as shown in Table 1.

[Example 5]
An adhesive tape was produced in the same manner as in Example 3 except that the thickness of the metal foil was changed as shown in Table 1.

[Example 8]
An adhesive tape was produced in the same manner as in Example 2 except that the thickness of the resin film was changed to 50 μm, the thickness of the metal foil was changed to 25 μm, and the thickness of the adhesive layer was changed to 45 μm.

[Examples 9 to 14]
An adhesive tape was produced in the same manner as in Example 8 except that the thickness of the metal foil was changed as shown in Table 1.

[Example 15]
A pressure-sensitive adhesive tape was produced in the same manner as in Example 8 except that the thickness of the metal foil and the thickness of the pressure-sensitive adhesive layer were changed as shown in Table 1.

[Example 16]
A pressure-sensitive adhesive tape was prepared in the same manner as in Example 9 except that a long-chain alkyl coating agent (product name: Pyroyl 1010, manufactured by Lion Specialty Chemicals Co., Ltd.) was used as the release agent.

[Example 17]
An adhesive tape was produced in the same manner as in Example 9 except that a fluorine-based coating agent (trade name: X70-201S, manufactured by Shin-Etsu Chemical Co., Ltd.) was used as a release agent.

[Example 18]
Rubber adhesive (100 parts natural rubber (peel crepe), 100 parts styrene butadiene rubber (trade name: 1013N, manufactured by JSR Corporation), aliphatic hydrocarbon resin (Nippon Zeon Corporation, trade name: Quinton R100) A pressure-sensitive adhesive tape was prepared in the same manner as in Example 9 except that 90 parts were dissolved in toluene to a concentration of 55% and prepared).

[Example 19]
An adhesive tape was prepared in the same manner as in Example 9 except that a urethane-based adhesive (trade name SP-205, manufactured by Toyochem Co., Ltd.) was used as the adhesive.

The adhesive tapes of Examples 1 to 19 were evaluated according to the following method. The results are shown in Tables 1 and 2.

(Flame retardance)
The adhesive tape is cut to a size of 102mm x 365mm, and the flame is applied to the release layer side (front side) of the adhesive tape and the adhesive by the method specified in the FMVSS-302 combustion test, which is the safety standard for US automobile interior parts. Each test in the case of flame contact to the layer side (back side) was conducted and evaluated according to the following criteria.
“◯”: a) The combustion distance is within 51 mm and the combustion time is within 60 seconds, or b) The combustion speed obtained by dividing the combustion distance by the combustion time is 102 mm / min or less.
“X”: a) The combustion distance exceeds 51 mm, or the combustion time exceeds 60 seconds, or b) The combustion speed obtained by dividing the combustion distance by the combustion time exceeds 102 mm / min.

(Adhesiveness)
Three PET spunlaces each having a size of 50 mm × 125 mm were stacked, and the PET layer was bonded to a SUS304 plate having a size of 50 mm × 125 mm × thickness 1.5 mm. This was subjected to pressure and heat bonding at 1.6 kgf / cm ² for 2 minutes in an atmosphere at 155 ° C. to obtain an evaluation adherend. An adhesive tape having a size of 20 mm × 100 mm was attached to this adherend in an atmosphere of 23 ° C. and 50% RH and pressure-bonded with a 2 kgf roller. Twenty minutes later, the film was peeled off in a 90 ° direction at a pulling rate of 300 mm / min with a tensile tester, the adhesive strength was measured, and the following criteria were evaluated.
“◯”: Adhesive strength is 5 N / 20 mm or more.
"X": Adhesive strength is less than 5N / 20mm.

(Impact resistance)
Three PET spunlaces each having a size of 200 mm × 200 mm were stacked, and the PET layer was bonded to a SUS304 plate having a size of 200 mm × 200 mm × thickness 1.5 mm. This was pressure-heat bonded for 2 minutes at 0.75 kgf / cm ² under an atmosphere of 155 ° C. to obtain an adherend for evaluation having a total weight of 320 g. Then, as shown in FIG. 2, a vinyl chloride tube 8 having a diameter of 17 mm simulating a harness is placed on the adherend 6 and an atmosphere of 23 ° C. and 50% RH is used using an adhesive tape 7 having a size of 20 mm × 100 mm. Two places were pasted so that the bonding area would be 20 mm × 25 mm. This was pressure-bonded with a 2 kgf roller to obtain a test sample having a total weight of 400 g. This test sample was repeatedly dropped from a height of 300 mm under an atmosphere of 23 ° C. and 50% RH, and the number of drops until the adhesive tape 7 was peeled off was measured and evaluated according to the following criteria.
-“◯”: The number of drops until the adhesive tape is peeled is 2 or more.
-"X": It is less than 2 times of dropping until an adhesive tape peels.

(Tear resistance)
A vinyl chloride tube having a diameter of 17 mm, imitating a harness, was fixed to the same adherend for evaluation as in the adhesive test described above with an adhesive tape having a size of 50 mm × 100 mm. At that time, it was confirmed whether or not the tape was torn. This test was conducted on 4 adherends by a total of 10 boys and 5 girls in their 20s to 40s. That is, 40 tubes were fixed to 40 adherends with 40 tapes. In this test, when the pressure-sensitive adhesive tape whose pressure-sensitive adhesive layer surface was protected with release paper was tested, the pressure-sensitive adhesive tape already cut into a size of 50 mm × 100 mm was used. When testing an adhesive tape with no release paper, the tester cuts the adhesive tape with a width of 50 mm with a tape dispenser (ZCUT (registered trademark) -9GR manufactured by Yaesu Light Industry Co., Ltd.) with a tape feed length of 100 mm. Was used for the test.
・ “○”: The tape is torn.
・ "X": The tape is not torn.

(Curl resistance)
A 50 mm wide adhesive tape wound around a paper tube having an inner diameter of 3 inches was set in the tape dispenser and cut with a tape feed length of 100 mm. Then, as shown in FIG. 3, the adhesive tape 9 was placed on a horizontal surface with the curled direction facing up. At that time, the positions of the cut surfaces of the tape were confirmed, and the curl resistance was evaluated according to the following criteria (see FIG. 3).
・ "○": Cut surfaces do not contact or overlap each other.
・ "X": Cut surfaces contact or overlap each other.

(Rewind property)
In the same manner as in the curl resistance test described above, an adhesive tape was set as a tape dispenser, and it was confirmed whether or not the tape could be rewound at a tape feed length of 100 mm.
-"O": It is possible to rewind and there is no adhesive that can be visually confirmed on the back side.
"X": It is impossible to rewind. Or the adhesive which can be visually confirmed remains on the back side.

(Workability)
In the above-described tear resistance test, the work time taken by 10 testers to fix the tube with the adhesive tape was measured, the average work time was calculated, and evaluated according to the following criteria.
-“◯”: Average work time is 4 minutes or less.
・ "X": Average work time exceeds 4 minutes.

Abbreviations in Tables 1 and 2 are as follows.
Release layer “S”: Silicone coating agent “A”: Long chain alkyl coating agent “F”: Fluorine coating agent Resin film “PET”: Polyester film “OPP”: Stretched polypropylene film Metal foil “Al” Soft Aluminum foil Adhesive layer “Ac”: Acrylic adhesive “G”: Rubber adhesive “U”: Urethane adhesive

<Evaluation results>
As shown in Table 1 and Table 2, in Examples 1 to 19, even when the metal foil was thin, in the flame retardancy test (FMVSS-302 combustion test), the release layer side (front side), the adhesive layer It has high flame resistance that can pass any flame contact from either side (back side), and has various properties such as adhesion, impact resistance, tear resistance, curl resistance, rewinding property, and workability. An excellent adhesive tape was obtained.

[Comparative Example 1]
A pressure-sensitive adhesive tape was produced in the same manner as in Example 9 except that the resin film was not used and only the metal foil was used as the base material. The adhesive tape of Comparative Example 1 was subjected to an evaluation test for tear resistance and curl resistance. The results are shown in Table 3.

The abbreviations in Table 3 have the same meaning as the abbreviations in Tables 1 and 2.

<Evaluation results>
As shown in Table 3, in Comparative Example 1, since the resin film was not used as the base material and only the metal foil was used as the base material, the tear resistance and curl resistance were inferior.

Next, the relationship between the difference (Ft−Mt) between the thickness of the resin film (Ft) and the thickness of the metal foil (Mt) (Ft−Mt) and the flame retardancy will be described in more detail with reference examples 1 to 9.

[Reference Examples 1 to 6]
Resin Film Thickness and Metal Foil Thickness An adhesive tape was prepared in the same manner as in Example 1 except that the thickness was changed as shown in Table 4.

[Reference Example 7]
An adhesive tape was produced in the same manner as in Example 1 except that a polyethylene film (PE film) having a thickness of 60 μm was used as the resin film.

[Reference Example 8]
An adhesive tape was produced in the same manner as in Reference Example 8 except that the thickness of the metal foil was changed to 20 μm.

[Reference Example 9]
A pressure-sensitive adhesive tape was prepared in the same manner as in Reference Example 4 except that 15 parts of phosphorus-based flame retardant particles (manufactured by Chisso Corporation, trade name Terrage C30) were added to the pressure-sensitive adhesive layer.

The same evaluation tests as in Examples were performed on the adhesive tapes of Reference Examples 1 to 9 described above. The results are shown in Table 4.

Abbreviations in Table 4 are as follows.
Release layer “S”: Silicone coating agent Resin film “PET”: Polyester film “PE”: Polyethylene film Metal foil “Al” Soft aluminum foil Adhesive layer “Ac”: Acrylic adhesive

<Evaluation results>
As shown in Table 4, in Reference Examples 1 to 8, the difference (Ft−Mt) between the thickness of the resin film (Ft) and the thickness of the metal foil (Mt) is large (Ft−Mt). It was unacceptable when the flame contacted from the side. On the other hand, in Reference Example 9, since a flame retardant was added to the pressure-sensitive adhesive layer, it passed the FMVSS-302 combustion test, but it was inferior in adhesion and impact resistance. From these results, the pressure-sensitive adhesive tapes of Examples 1 to 19 described above have a smaller thickness difference (Ft−Mt) than those of Reference Examples 1 to 8 (particularly 2 or less). It can be seen that this is a very useful embodiment in that it passes the FMVSS-302 flammability test without the addition.

The adhesive tapes of Reference Examples 1 to 8 failed the high flame retardancy test called FMVSS-302 combustion test. However, since the pressure-sensitive adhesive tapes of Reference Examples 1 to 8 have the same layer structure of resin film / metal foil / pressure-sensitive adhesive as in Examples 1 to 19, the metal foil / foamed resin layer (or, for example, as in Patent Document 1) Resin film) / Flame retardancy when flame-contacted from the front side is higher than that of adhesive tape having a layer structure of adhesive. Accordingly, in this respect, the adhesive tapes of Reference Examples 1 to 8 are also superior to the conventional adhesive tape.

Next, with reference examples 10 and 11, the relationship between the release layer and the unwinding property will be described in more detail.

[Reference Example 10]
An adhesive tape was prepared in the same manner as in Example 9 except that the release layer was not provided.

[Reference Example 11]
An adhesive tape was produced in the same manner as in Example 9 except that &#21085; release paper (separator) was provided instead of the release layer.

The same evaluation test as the example was performed on the adhesive tapes of Reference Examples 10 and 11 described above. The results are shown in Table 5.

The abbreviations in Table 5 have the same meaning as the abbreviations in Tables 1 and 2.

<Evaluation results>
As shown in Table 5, since no release layer was provided in Reference Example 10, the curl resistance, rewinding property and workability were inferior. In Comparative Example 12, a release paper (separator) was provided in place of the release layer, so the curl resistance and rewinding properties were good, but the workability was inferior because it increased the effort to peel the release paper. It was. From this result, since the adhesive tapes of Examples 1 to 19 described above have a release layer, &#21085; very useful in that the above-mentioned performance such as rewinding property is excellent without using a release paper. It can be understood that this is an embodiment.

The adhesive tapes of Reference Examples 10 and 11 were inferior in the above performance. However, the pressure-sensitive adhesive tapes of Reference Examples 10 and 11 have the same resin film / metal foil / pressure-sensitive adhesive layer structure as in Examples 1 to 19, and the resin film thickness (Ft) and the metal foil thickness. Since the difference (Ft−Mt) in (Mt) is small (particularly 2 or less), it is excellent in that it passes the FMVSS-302 combustion test.

The holding pressure-sensitive adhesive tape of the present invention has high flame retardancy and excellent properties such as impact resistance and workability. Therefore, it is very useful in the field where these characteristics are required, for example, in the fixing application of vehicle parts such as automobiles.

DESCRIPTION OF SYMBOLS 1 Laminate base material 1a Metal foil 1b Resin film 1c Adhesive layer 2 Adhesive layer 3 Release layer 6 Adhering body 7 Adhesive tape 8 Vinyl chloride tube 9 Adhesive tape

Claims (8)

A holding pressure-sensitive adhesive tape comprising a laminated base material having a metal foil and a resin film, and an adhesive layer provided on at least the metal foil side of the laminated base material. The pressure-sensitive adhesive tape for holding according to claim 1, wherein when the thickness of the metal foil is less than 50 µm, the thickness of the metal foil (Mt) and the thickness of the resin film (Ft) satisfy the following formula (1).
Ft / Mt ≦ 2 (1) The holding adhesive tape according to claim 1, wherein the metal foil has a thickness of 7 to 130 µm. 2. The pressure-sensitive adhesive tape for holding according to claim 1, wherein the resin film has a thickness of 4 to 250 μm. The pressure-sensitive adhesive tape for holding according to claim 1, further comprising a release layer on the resin film side of the laminated substrate. 2. The holding adhesive tape according to claim 1, wherein the metal constituting the metal foil is aluminum. In the FMVSS-302 burning test, a) the burning distance is within 51 mm and the burning time is within 60 seconds, or b) the burning distance, regardless of whether the adhesive tape is in contact with the front side or the back side. The holding pressure-sensitive adhesive tape according to claim 1, wherein the burning rate obtained by dividing the amount by the burning time is 102 mm / min or less. The holding adhesive tape according to claim 1, which is used for holding vehicle parts.

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