Road marking sheet

Abstract

To provide a baseboard device on which a panel material can be placed when the interior panel material is fixed to a wall surface, and which is less likely to be deformed.SOLUTION: A road marking sheet 10 that is heated and adheres to an installation surface, comprising a thermoplastic base sheet 20 that softens or melts by heating during construction, and an adhesive layer 30 that is placed on the installation surface side of the base sheet 20, and the base sheet 20 contains an ethylene-vinyl acetate copolymer, and the adhesive layer 30 is composed mainly of polyamide or polyester, and the porosity of the adhesive layer 30 is 50% or more.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a road marking sheet for drawing lines, characters, symbols, etc. on a road surface to indicate a center line of a road, a crosswalk, etc.

Background Art

[0002] Regarding road marking sheets for marking lines, characters, etc. on a road surface, various inventions have been disclosed. For example, in Patent Document 1, 200 to 500 parts by weight of additives such as a colorant, a filler, and a reflector are mixed into 100 parts by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 15 to 40% by weight and a melt index of 50 to 150, and these are uniformly melt-mixed and formed into a sheet-like road marking sheet, which is disclosed by the applicant of the present application.

[0003] Further, in Patent Document 2, there is disclosed a road surface marking material in which a hot melt adhesive is laminated on one surface of a base material, the base material has a softening point of 90°C or higher, and the hot melt adhesive has an elastic modulus of 10

[0005] , ~10 10 Pa and a softening point of 90°C or lower. [[ID=2​​​​​​​​​​​​​​​​​​​​​​​​Incidentally, the roads on which road marking sheets described in Patent Document 1 and road surface marking materials described in Patent Document 2 are installed are typically assumed to be asphalt-paved roads. On the other hand, concrete surfaces are also installation surfaces for such road marking sheets, and there has been a need for road marking sheets that can be used on installation surfaces with different surface conditions.

[0006] The present invention solves the aforementioned problems and provides a marking sheet that is easy to install and has excellent adhesion regardless of the condition of the installation surface. [Means for solving the problem]

[0007] To solve the above problems, the inventors conducted diligent research and discovered that by creating a marking sheet consisting of a base sheet containing a specific resin component and an adhesive layer mainly composed of that specific resin component, the sheet can have strong adhesive strength even on asphalt pavement and concrete surfaces. This eliminates the need for pretreatment such as applying a primer to improve adhesion, which was previously required depending on the installation surface. As a result, the inventors have found that a road marking sheet can be placed in a predetermined position on the installation surface and firmly adhered to the installation surface by heat treatment, thus completing the present invention.

[0008] To achieve the above objective, the present invention has the following configuration. In other words, the road marking sheet according to the present invention is a road marking sheet that adheres to an installation surface when heated, and comprises a thermoplastic base sheet that softens or melts when heated during installation, and an adhesive layer disposed on the installation surface side of the base sheet, wherein the base sheet contains an ethylene-vinyl acetate copolymer, the adhesive layer is mainly composed of polyamide or polyester, and the adhesive layer is characterized by being either a nonwoven fabric made of adhesive component fibers, or a sponge-like material with voids that are connected in the vertical and horizontal directions. Furthermore, the road marking sheet according to the present invention is a road marking sheet that adheres to an installation surface when heated, and comprises a thermoplastic base sheet that softens or melts when heated during installation, and an adhesive layer disposed on the installation surface side of the base sheet, wherein the base sheet contains an ethylene-vinyl acetate copolymer, the adhesive layer is mainly composed of polyamide or polyester, and the adhesive layer has voids, so that air in the gap formed between the installation surface and the adhesive layer during installation can move through the voids in the adhesive layer to the side edge of the adhesive layer. [Effects of the Invention]

[0009] According to the present invention, a road marking sheet with excellent workability can be obtained regardless of the condition of the installation surface. [Brief explanation of the drawing]

[0010] [Figure 1] This is a front view showing one embodiment of the baseboard device according to the present invention. [Figure 2] This is an enlarged cross-sectional view along line AA in Figure 1. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be specifically described with reference to the drawings. In the drawing, 10 is a road marking sheet. The road marking sheet 10 shown in Figure 1 is formed in a rectangular shape.

[0012] Figure 2 is a cross-sectional view of Figure 1, section AA. The road marking sheet 10 consists of two layers: a base sheet 20 and an adhesive layer 30 placed on its lower surface. In this embodiment, the adhesive layer 30 is formed by applying adhesive to the lower surface of the base sheet 20.

[0013] The road marking sheet 10 is formed to adhere to the installation surface by placing it on the road surface or other installation surface, making contact with the bottom surface, and heating it from above with a flame or other method. Specifically, the base sheet 20 contains a binder as a raw material that softens or melts when heated and hardens again when heating is stopped. More specifically, in addition to the binder, the base sheet 20 contains additives such as wax and pigment as raw materials, and these are uniformly melted and mixed to form a sheet, thereby providing the base sheet 20.

[0014] As the binder, ethylene-vinyl acetate copolymer, rosin, petroleum resin, etc., can be selected or used in combination. In this embodiment, the base sheet 20 contains ethylene-vinyl acetate copolymer as the binder at a concentration of approximately 10 to 30% by weight.

[0015] The base sheet 20 can take various forms, such as a long sheet of a fixed width or a combination of multiple base sheets 20. In the latter case, a specific example is a rectangular base sheet 20 with holes formed through it in the thickness direction, into which another base sheet 20, formed to match the outer diameter of the holes, is fitted to form an integrated structure. By using letters, numbers, or symbols for the outer diameter of the holes, and by changing the color tone of the other base sheet 20, it can also be used to provide information to pedestrians and vehicles. These base sheets 20 with different color tones contain different pigments, but the other raw materials are almost the same.

[0016] The adhesive used in the adhesive layer 30 can be polyamide or polyester, which have a higher melting point or softening temperature than ethylene-vinyl acetate copolymer. Generally, when installing the road marking sheet 10, the adhesive layer 30 is placed on the installation surface side, and the road marking sheet 10 is heated from the base sheet 20 side to melt it, then cooled and solidified to adhere it to the installation surface. The installation surface is usually an asphalt pavement or concrete surface. For example, when installing on an asphalt pavement surface, if the adhesive layer melts first during heating, the adhesive strength with the base sheet 20 will not be fully developed, and some of the melted adhesive layer may flow into the recesses for the asphalt, potentially reducing the adhesive strength between the base sheet 20 and the adhesive layer 30 in some areas. Therefore, by using polyamide or polyester, which have a higher melting point or softening temperature than the ethylene-vinyl acetate copolymer contained in the base sheet 20, the base sheet 20 is also melted or softened when the adhesive layer 30 is melted or softened, so sufficient adhesive strength is achieved.

[0017] Considering the installation method of the road marking sheet 10 as described above, it is preferable for the adhesive layer 30 to be thin. This is because if the adhesive layer 30 is thick, when the road marking sheet 10 is heated during installation, the heat rises from above, and it takes time for the lower part of the adhesive layer 30 in contact with the installation surface to be sufficiently heated. This may result in insufficient heating time, which could prevent the adhesive strength of the adhesive layer 30 from being fully developed on the installation surface, or excessive heating time, which could cause thermal degradation such as discoloration of the base sheet 20.

[0018] One method for forming a thin adhesive layer 30 on the lower surface of the base sheet 20 is to simultaneously mold the adhesive layer 30 when the base sheet 20 is formed by extrusion molding. However, this method can be used when the base sheet 20 is in the form of a long body of a certain width, but it is difficult to use the above method for a form in which multiple base sheets 20 are combined.

[0019] Therefore, in the present invention, the adhesive layer 30 is formed on the base material sheet 20 later. Specifically, methods include directly forming a thin sheet-like adhesive layer 30 on the lower surface of the base material sheet 20 by spray coating, and forming a sheet-like adhesive layer 30 and disposing it on the lower surface of the base material sheet 20.

[0020] Examples of the form of the thin sheet-like adhesive layer 30 include dissolving the adhesive in a solvent to form a solution, or heating and melting the adhesive, and forming the adhesive layer 30 by spray coating the solution or melt on the lower surface of the base material sheet 20. When the adhesive is heated and melted, it is generally difficult to reduce the thickness of the adhesive layer 30. Therefore, as the form of the adhesive layer 30, it is preferably formed in a sponge-like shape having voids that communicate in the vertical and width directions.

[0021] By forming a sponge-like adhesive layer 30 having voids, even if the thickness of the adhesive layer 30 per unit area increases, the amount (basis weight) of the adhesive component per unit area can be reduced. Therefore, as the road marking sheet 10, when it is arranged on the construction surface and heated, the base material sheet 20 that melts first can easily penetrate into the voids of the sponge-like adhesive before melting, so the adhesive layer 30 can easily melt to the bottom, and an improvement in the adhesive strength at the interface between the base material sheet 20 and the adhesive layer 30 can be expected.

[0022] Also, examples of forming the latter sheet-like adhesive layer 30 include an extruded thin sheet-like elongated body by extrusion molding, and a non-woven fabric made of fibers of the adhesive component. When using a non-woven fabric, the same effects as those of the aforementioned sponge-like adhesive layer 30 can be expected.

[0023] Furthermore, when using a thin sheet-like form for the aforementioned adhesive layer 30, the asphalt pavement or concrete surface, which is the application surface, is not always smooth. Therefore, when the road marking sheet 10 is placed on the application surface, a gap (air) exists between the application surface and the adhesive layer 30. As a result, heating may cause the air to expand, potentially damaging part of the road marking sheet 10 or leaving gaps, preventing sufficient adhesive strength from being achieved. On the other hand, when using a sponge-like adhesive layer 30 with voids or an adhesive layer 30 made of nonwoven fabric, even if gaps (air) exist, the air can move from the voids in the adhesive layer 30 along the side edges of the adhesive layer 30. Therefore, as the adhesive layer 30 melts after heating, any remaining air can be expelled to the outside, thus reducing the amount of gaps.

[0024] Next, an embodiment of the road marking sheet 10 according to the present invention is shown.

[0025] (Example 1) An adhesive layer 30 was formed by applying a dimer acid-based polyamide (manufactured by Bostec, product name "HM4229") as an adhesive to the lower surface of a base sheet 20 containing an ethylene-vinyl acetate copolymer (manufactured by Sekisui Jushi Co., Ltd., product name "Jisline S", width 150 mm). Specifically, a solid adhesive (polyamide) was placed in the container of a hot melt spray gun, the container was heated to 180-210°C to melt the polyamide, and the melted polyamide was applied to the base sheet 20 with its bottom surface facing upwards to form a sponge-like adhesive layer 30. After drying for 10 seconds, a road marking sheet was created with the adhesive layer 30 solidified.

[0026] (Apparent specific gravity and void ratio of the adhesive layer) The apparent specific gravity of the adhesive layer 30 was calculated in accordance with the fabric testing method for woven and knitted fabrics (JIS L1096). Regarding the thickness of the adhesive layer 30, if it was possible to peel the adhesive layer 30 from the base sheet 20, or if a separate adhesive layer 30 was used, the thickness of the peeled adhesive layer 30 was measured. If peeling from the base sheet 20 was difficult, the thickness of the adhesive layer 30 was calculated by subtracting the thickness of the base sheet 20 from the thickness of the road marking sheet 10. Furthermore, when the adhesive layer 30 was formed by directly applying the adhesive to the application surface, the void ratio was considered to be 0%. In the road marking sheet 10 according to this embodiment, it was possible to peel the adhesive layer 30 from the base sheet 20, and the void ratio (%) was calculated from the thickness of the peeled adhesive layer 30 (unit: μm), the specific gravity of the adhesive component (g / cm3), the basis weight (g / m2), and the apparent density (g / cm3). The measurement results for each physical property are shown in Table 1. The void ratio (%) was calculated based on the following formula. Porosity (%) = (1-apparent specific gravity) / density x 100.

[0027] (Asphalt adhesion evaluation test) As the application surface, the road marking sheet 10 was placed on the asphalt pavement, and the entire surface of the base sheet 20 was heated evenly from the top side using a propane burner (nozzle diameter 100 mm, gas pressure 0.03 MPa, burner height 100 mm) to melt the road marking sheet 10, and it was cured for 1 hour. Next, in order to measure the adhesive strength using the Building Research Institute type adhesive testing machine (Building Research Institute type tensile tester, manufactured by Oxjack Co., Ltd., product name "LPT-1500"), a special jig was bonded to the base sheet 20 with adhesive (manufactured by Sekisui Jushi Co., Ltd., product name "Road Bond"), and it was cured for 24 hours, and the force (kgf / cm) when pulled upward using the Building Research Institute type tensile tester was measured. 2 The strength of the bond was measured and defined as the adhesive strength. The results of the adhesiveness evaluation are shown in Table 1.

[0028] (Concrete adhesion evaluation test) An adhesion evaluation test similar to the asphalt adhesion evaluation was performed on a concrete surface as the application surface, and the adhesion strength to the application surface was measured. The results of the adhesion strength measurement are shown in Table 1.

[0029] As shown in Comparative Examples 1 and 2 below, each adhesive was applied to the asphalt pavement surface and the concrete surface, and the adhesive layer 30 was formed by curing for 1 hour in Comparative Example 1 and 2 hours in Comparative Example 2 to allow it to dry completely. Subsequently, the base sheet 20 was placed on top of the adhesive layer, and the base sheet 20 was heated from the top side with a propane burner to melt it, and then cured for 1 hour. After that, an adhesion evaluation test was conducted to measure the adhesion strength between the applied surface and the adhesive layer 30. Comparative Example 1 was used as the standard for the adhesion strength of the asphalt pavement surface, and Comparative Example 2 was used as the standard for the adhesion strength of the concrete surface, with each adhesion strength set to 100. In Table 1, the adhesion strengths of each example and each comparative example are listed as relative values ​​to the adhesion strengths of Comparative Examples 1 and 2.

[0030] [Table 1]

[0031] (Example 2) A road marking sheet 10 was obtained by laminating a polyester nonwoven fabric (Kureha Tech Co., Ltd., product name "G4030") as an adhesive layer 30 onto a base sheet 20 containing an ethylene-vinyl acetate copolymer (manufactured by Sekisui Jushi Co., Ltd., product name "Jisline S", width 150 mm). Similar to Example 1, the porosity of the adhesive layer 30 was calculated and adhesion evaluation tests were conducted on various application surfaces. The physical properties and adhesion evaluation results are shown in Table 1.

[0032] (Example 3) In Example 2, a road marking sheet 10 was obtained in the same manner as in Example 2, except that a polyamide nonwoven fabric (manufactured by Kureha Tech Co., Ltd., product name "LSN0030") was used as the adhesive layer 30. The porosity of the adhesive layer 30 was calculated and adhesion evaluation tests were performed on various application surfaces in the same manner as in Example 1. The physical properties and adhesion evaluation results are shown in Table 1.

[0033] (Comparative Example 1) In Example 1, a solvent-type adhesive mainly composed of chloroprene rubber (manufactured by Sekisui Jushi Co., Ltd., product name "Jisline S Primer") was used instead of adhesive. In each adhesion evaluation, instead of applying the adhesive to the base sheet 20, the solvent-type adhesive was applied to the asphalt pavement surface and cured for 1 hour to form an adhesive layer 30. Then, the base sheet 20 was placed on top of it and heated from the top side of the base sheet 20 with a propane burner to melt it. After curing for 24 hours, an adhesion evaluation test to the asphalt pavement surface was conducted in the same manner as in Example 1. In this embodiment, since a solvent-type adhesive was used for the adhesive layer 30 and it was applied to the asphalt pavement surface, the specific gravity, thickness, basis weight, apparent specific gravity, etc. were not measured, and the void ratio was set to 0% as it was assumed that no voids were present. The results of each adhesion evaluation are shown in Table 1.

[0034] (Comparative Example 2) In Comparative Example 1, a different solvent-type adhesive mainly composed of epoxy resin (manufactured by Sekisui Jushi Co., Ltd., product name "Epoprimer C") was used. In each adhesion evaluation, instead of applying the adhesive to the base sheet 20, the solvent-type adhesive was applied to the concrete surface and cured for 1 hour to form an adhesive layer 30. Then, the base sheet 20 was placed on top of it and heated from the top side of the base sheet 20 with a propane burner to melt it. After curing for 24 hours, an adhesion evaluation test to the concrete surface was performed in the same manner as in Example 1. In this embodiment, since the adhesive layer 30 uses a solvent-type adhesive and is applied to a concrete surface, specific gravity, thickness, basis weight, apparent specific gravity, etc. were not measured, and the void ratio was assumed to be 0% as no voids were generated. The results of each adhesion evaluation are shown in Table 1.

[0035] (Comparative Example 3) In Example 1, a road marking sheet 10 was obtained in the same manner as in Example 1, except that a sponge-like adhesive layer 30 was obtained using an adhesive containing ethylene-vinyl acetate copolymer (manufactured by Sanyo Life Material Co., Ltd., product name "Pure Melt P-502") as the adhesive. The porosity of the adhesive layer 30 was calculated and adhesion evaluation tests were performed on various application surfaces in the same manner as in Example 1. The physical properties and adhesion evaluation results are shown in Table 1.

[0036] (Comparative Example 4) In Example 1, a nylon-based polyamide (manufactured by Arkema, trade name Platamid HX2544) was used as the adhesive, but it clogged the spray gun nozzle and could not be applied to the substrate sheet 20. Therefore, each adhesion evaluation could not be performed.

[0037] (Comparative Example 5) As the adhesive layer 30, a dimer acid polyamide (manufactured by Bostec, product name "HM4229") was pressed in a hot press at 180°C for 2 minutes to form a sheet. The adhesive layer 30 was laminated onto a base sheet 20 containing ethylene-vinyl acetate copolymer (manufactured by Sekisui Jushi, product name "Jisline S", width 150 mm) to obtain a road marking sheet 10. For the adhesive layer 30 in this embodiment, the void ratio was set to 0%, assuming that no voids were present. The adhesive layer 30 and base sheet 20 were placed in order on an asphalt pavement surface as the application surface, and the base sheet 20 was heated from the top side with a propane burner to melt it, and then cured for 24 hours. Subsequently, an adhesion evaluation test was conducted and the adhesive strength to the application surface was measured. The adhesion evaluation results are shown in Table 1.

[0038] In Comparative Examples 1 and 2, curing of the adhesive takes 1 hour in Comparative Example 1 and 2 hours in Comparative Example 2. In other words, the adhesive application process and the installation of the base sheet 20 are separated. However, in Examples 1 to 3, the adhesive application process and the installation of the base sheet 20 can be performed substantially simultaneously, resulting in superior workability and excellent adhesive strength.

[0039] The reason why Examples 1 to 3 have higher adhesive strength than Comparative Examples 1 and 2 is thought to be due to the difference in the morphology of the adhesive layer 30. Specifically, when installing the road marking sheet 10, heating is performed from the base sheet 20 side, so the base sheet 20 melts first, and the adhesive layer 30 melts later. In Examples 1 to 3, the void ratio of the adhesive layer 30 exceeds 50%, and the air in the adhesive layer 30 can move along the side edges of the adhesive layer 30, thus reducing the amount of air that can remain in the adhesive layer 30 and reducing its impact on the adhesive strength. In addition, since the melted base sheet 20 can penetrate into the voids, the contact area between the base sheet 20 and the adhesive layer 30 increases, which is thought to increase the adhesive strength. Furthermore, as the contact area between the base sheet 20 and the adhesive layer 30 increases, the adhesive layer 30 melts more easily when heated, which is thought to make it easier for adhesive strength to be expressed on the installation surface.

[0040] Comparing Example 1 and Comparative Example 5, although the material of the adhesive layer 30 is the same, the difference lies in the form of the adhesive layer 30: it is a sponge-like form with voids, while Comparative Example 5 is a thin sheet-like form without voids. As a result, the adhesive strength to the asphalt pavement surface in Comparative Example 5 is more than 30% lower than that of Example 1. As mentioned above, when the adhesive layer 30 is in the form of a thin sheet, if a gap (air) is created between the application surface and the adhesive layer 30, it is difficult for the air to escape to the outside, which is likely why the adhesive strength was not fully realized.

[0041] Comparative Example 3 used the same resin component as the ethylene-vinyl acetate copolymer contained in the base sheet 20 as the main component of the adhesive in the adhesive layer 30. Similar to Example 1, the adhesive layer 30 was a sponge-like adhesive layer with voids, but its adhesive strength to the concrete surface was inferior to that of Examples 1 to 3 and Comparative Example 2. [Explanation of symbols]

[0042] 10 Road marking sheets 20 Base sheet 30 Adhesive layer

Claims

[Claim 1] A road marking sheet that is heated and adheres to the installation surface, A thermoplastic base sheet that softens or melts when heated during construction, The base sheet comprises an adhesive layer disposed on the installation surface side, The aforementioned base sheet contains an ethylene-vinyl acetate copolymer. The adhesive layer is mainly composed of polyamide or polyester. The adhesive layer is either a nonwoven fabric made of adhesive fiber, or a sponge-like material having voids that are connected in the vertical and horizontal directions. A road marking sheet characterized by the following features.

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