Adhesive sheet and manufacturing method of adhesive sheet

Abstract

To provide an adhesive sheet in which a rugged shape of a release liner is hard to be seen so as to appear raised on the surface of adhesive sheet, and a method for manufacturing an adhesive sheet.SOLUTION: An adhesive sheet 100 has a substrate layer 110, an adhesive layer 120, and a release liner 130 in this order in a lamination direction, where a rugged shape 131 is formed on the surface on adhesive layer side of the release liner, and 60-degree specular gloss on one surface 111 of a substrate layer side which is measured according to JIS Z 8741 is 30% or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pressure-sensitive adhesive sheet and a method for producing the pressure-sensitive adhesive sheet. [Background technology]

[0002] Conventionally, in order to prevent swelling of a pressure-sensitive adhesive sheet attached to an adherend, for example, a method disclosed in Patent Document 1 has been proposed. As shown, a release liner having a textured surface is used.

[0003] The release liner having a concave-convex shape is used by laminating it with the adhesive layer of the adhesive sheet. The concave and convex shapes of the inner are transferred to the adhesive layer. Therefore, when the pressure-sensitive adhesive sheet is attached to an adherend via the pressure-sensitive adhesive layer, swelling is prevented. It can be stopped. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-058395 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a release liner having an uneven surface is used with a PSA sheet having a relatively high glossy surface, When used in this way, the uneven shape of the release liner is visible as if it were raised on the surface of the adhesive sheet. This sometimes happens.

[0006] This is because the base layer of the PSA sheet deforms to fit the uneven shape of the release liner. The reason for this is thought to be that the deformation is more noticeable on adhesive sheets with a relatively glossy surface. can be done.

[0007] If the uneven shape of the release liner is visible as it stands out on the surface of the adhesive sheet, it is a decorative film. Adhesive sheets such as films are not preferred because they may impair the design.

[0008] The present invention has been made in view of such problems, and aims to provide a method for manufacturing a pressure-sensitive adhesive sheet, comprising the steps of: To provide an adhesive sheet that is hardly visible as if it is floating on the surface and a method for manufacturing the adhesive sheet The purpose is to: [Means for solving the problem]

[0009] In order to achieve the above object, the pressure-sensitive adhesive sheet of the present invention comprises a substrate layer, a pressure-sensitive adhesive layer, and a release liner. and a release liner having a concave-convex shape on the surface of the pressure-sensitive adhesive layer side. The shape is formed, and the measurement is performed on one surface of the base layer side in accordance with JIS Z 8741. The 60-degree specular gloss is 30% or less.

[0010] In order to achieve the above object, the method for producing a pressure-sensitive adhesive sheet of the present invention is a method for producing a pressure-sensitive adhesive sheet in accordance with JIS Z 8741. Prepare a sheet substrate having a surface whose 60-degree specular gloss measured according to the method is 30% or less. and a release liner having a concave-convex shape formed on the surface thereof is prepared, and A pressure-sensitive adhesive composition is applied to at least one of the release liners, and the sheet substrate and the release liner are bonded to each other. At the time of lamination, the sheet substrate is adhered to at least one of both surfaces of the sheet substrate. At least one of the surfaces having a 60-degree specular gloss of 30% or less is opposite to the release liner. The release liner is oriented so that the surface on which the concave and convex shapes are formed faces the sheet substrate. It is directed at. [Effects of the Invention]

[0011] According to the invention having the above configuration, the gloss of the surface of the pressure-sensitive adhesive sheet is suppressed, so that the release liner Even if the base layer of the adhesive sheet deforms to fit the uneven shape of the nozzle, such deformation is not noticeable. The uneven surface of the release liner is visible on the surface of the adhesive sheet. This can prevent this. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a side view of the pressure-sensitive adhesive sheet according to the embodiment. [Figure 2] FIG. 2 is a side view of the pressure-sensitive adhesive sheet of the embodiment with the release liner removed. [Figure 3] FIG. 2 is a plan view of a release liner. [Figure 4] 1A to 1C are diagrams illustrating an outline of a method for manufacturing a pressure-sensitive adhesive sheet according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The proportions are exaggerated for illustrative purposes and may differ from the actual proportions.

[0014] As shown in FIG. 1, the pressure-sensitive adhesive sheet 100 of the embodiment includes a base layer 110, a pressure-sensitive adhesive layer 120, and a release liner 130 in this order in the stacking direction. For example, it is a decorative film that decorates an adherend. For example, the present invention is applicable to vehicles such as four-wheeled automobiles and two-wheeled motorcycles, but is not limited thereto. It may be attached to an adherend other than the above, and it may also be used for any purpose. There is no particular limitation. The adhesive sheet 100 is used as, for example, a mark or a sticker. It may also be used as an alternative to striping tape or painting.

[0015] The adhesive sheet 100 has a surface 111 on the side of the base layer 110 that conforms to JIS Z 874 The 60-degree specular gloss measured in accordance with JIS No. 1 is greater than 0% and less than 30%. By roughening the surface 111, the specular glossiness can be reduced, but how can the surface 111 There is no particular limitation on how to reduce the specular gloss of the surface 111. For example, a method of embossing the base material layer 110, a method of adding a filler to the base material layer 110, Examples of methods include, but are not limited to, methods such as

[0016] The substrate layer 110 is used for an adherend with many curved surfaces, such as a vehicle, for example, a four-wheeled automobile or a two-wheeled motorcycle. It is preferable that the surface has good conformability to the surface of the substrate, and for example, the surface is made of a vinyl chloride resin. Examples of vinyl chloride resins include polyvinyl chloride, vinyl chloride monomer, and Examples include copolymers of vinyl chloride monomer with other copolymerizable monomers. The material for forming the base layer 110 is not limited, and may be, for example, an acrylic resin, a urethane resin, or may be other resin materials such as fluorine-based resin.

[0017] Furthermore, the base material layer 110 may contain, as needed, additives such as plasticizers, antioxidants, ultraviolet absorbers, and photo-sensitive materials. It may contain various additives such as stabilizers, flame retardants, antistatic agents, foaming agents, lubricants, fillers, and colorants. The thickness of the base layer 110 is, for example, 10 μm to 300 μm, but is not limited to this. It will not be done.

[0018] The base layer 110 is colored, and the adhesive layer 120 is visible from the base layer 110 side. In this embodiment, the base layer 110 contains a colorant, thereby blocking the color of the base layer 110. However, the present invention is not limited to this embodiment. Configurations in which at least one of the ten surfaces is colored are also within the scope of the present invention.

[0019] Furthermore, the base layer 110 is not limited to a plain form as in this embodiment, and may have, for example, a pattern, Letters, numbers, symbols, etc. may be provided on the base layer 110 itself. Alternatively, for example, a printed layer may be formed on at least one of the two surfaces of the base layer 110. It may be provided as follows.

[0020] The adhesive layer 120 may be made of, for example, an acrylic adhesive, a rubber adhesive, a silicone adhesive, The adhesive layer is formed from a polyurethane adhesive, a polyester adhesive, etc. The material for forming the adhesive layer 120 is not limited to these. The thickness of the adhesive layer 120 is, for example, 5 μm to The thickness is 100 μm, but is not limited to this.

[0021] The release liner 130 is releasably disposed on the surface of the adhesive layer 120. The roller 130 is made of a paper substrate such as fine paper, glassine paper, or coated paper, and a layer of polyethylene or the like. A thermoplastic resin is laminated, and a release agent layer made of a release agent such as silicone is provided. The thickness of the release liner 130 may be, for example, For example, it is 30 μm to 180 μm, but is not limited to this.

[0022] As shown in FIG. 2, the release liner 130 has a protrusion 132 on the surface of the adhesive layer 120 side. The uneven shape 131 is formed by the uneven shape 131. The dimensions of the uneven shape 131 are not particularly limited. However, the height L1 of the convex portion (or the depth of the concave portion) is, for example, 7 μm or more and 20 μm or less, and the width L 2 is, for example, 50 μm or more and 70 μm or less, and the interval L3 between the protrusions is, for example, 400 μm or more. The uneven shape 131 is transferred in reverse onto the adhesive layer 120, and this As a result, recesses 121 are formed in the adhesive layer 120.

[0023] Since the depressions 121 are formed in the adhesive layer 120, the adhesive sheet 100 When the adhesive layer 120 is attached to the adherend via the adhesive layer 120, if air is present between the adhesive layer 120 and the adherend, Even if the adhesive sheet 100 is pressed against the adhesive layer 102, the recesses 121 allow air to escape, thereby preventing the adhesive sheet 100 from swelling.

[0024] In this embodiment, the protrusion 132 has a triangular cross-sectional shape, but is not limited thereto. First, the protrusion 132 may have, for example, a rectangular cross section, a mountain-shaped cross section with rounded vertices, a semicircular cross section, or the like. The protrusions 132 may have other cross-sectional shapes, such as a cross-sectional shape of the release liner 13. The protrusions 13 are formed by embossing the surface of the There is no particular limitation on whether or not 2 is formed.

[0025] As shown in FIG. 3, the protrusions 132 extend in the planar direction on the surface of the release liner 130 . In this embodiment, a plurality of linearly extending protrusions 132 intersect in a mesh pattern. The shape is not limited to the above. A plurality of linearly extending protrusions 132 are arranged parallel to each other without intersecting each other. The protrusions 132 may also be curved.

[0026] Next, a method for producing a pressure-sensitive adhesive sheet according to an embodiment will be described.

[0027] As shown in FIG. 4, in the method for producing a pressure-sensitive adhesive sheet according to this embodiment, The base sheet 110A and the release liner 130 are prepared. After the adhesive composition 120A is applied to the sheet substrate 110A and the release liner 130 and are pasted together.

[0028] The sheet substrate 110A has a 60-degree specular gloss measured in accordance with JIS Z 8741. The sheet substrate 110A has a surface 111A in which the ratio is greater than 0% and not more than 30%. At least one of the surfaces 111A and 111B has a 60-degree specular gloss of 30% or less. The 60-degree specular gloss of both the front and opposite surfaces may be 30% or less, or one of the surfaces may be The surface 111A alone may have a 60-degree specular gloss of 30% or less. When the release liner 130 is attached to the sheet, the surface 111A faces away from the release liner 130. It is turned to the side.

[0029] The release liner 130 has a surface on which the uneven pattern 131 is formed, and the adhesive composition 120A is applied to the surface. The adhesive composition 120A is applied to the sheet substrate 110A, and the adhesive composition 120A is attached to the sheet substrate 110A with the adhesive composition 120A facing the sheet substrate 110A. is applied by a knife coater, but the method of application is The coating machine is not particularly limited, and may be, for example, a die coater, a curtain coater, or the like.

[0030] The adhesive composition 120A includes an adhesive and a crosslinking agent. The crosslinking agent is not particularly limited. Examples of such crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, and metal chelate-based crosslinking agents. These crosslinking agents may be used alone or in combination of two or more. stomach.

[0031] The adhesive composition 120A may also contain, for example, a plasticizer, a filler, an antistatic agent, an antiblocking agent, etc. The release liner 130 may contain additives such as a blocking agent, a light stabilizer, and a colorant. When applying the adhesive composition 120A, a solvent may be added to adjust the viscosity.

[0032] After the adhesive composition 120A is applied, the adhesive composition 120A is cured to form an adhesive layer. The adhesive layer 120 is formed. The method of curing the adhesive composition 120A is particularly However, the curing is not limited to this, and may be performed by heating, for example. Other embodiments, such as curing the pressure-sensitive adhesive composition 120A by irradiation with light, are also within the scope of the present invention. Included in.

[0033] After the adhesive layer 120 is formed on the release liner 130, the laminate and the sheet substrate are The adhesive sheet 10 is adhered to the substrate 110A via the adhesive layer 120. 0 is created.

[0034] In this embodiment, a laminate of the adhesive layer 120 and the release liner 130 is formed on the sheet substrate 11. 0A, the adhesive sheet 100 is produced, but the present invention is not limited to this form. For example, the sheet substrate 110A may have a pressure-sensitive adhesive layer on the surface opposite to the surface 111A. The composition 120A is applied and cured to form a laminate of the sheet substrate 110A and the adhesive layer 120. A laminate is formed, and the laminate is bonded to a release liner 130 to form an adhesive sheet. A card 100 may be produced.

[0035] Next, the effects of this embodiment will be described.

[0036] Before the sheet substrate 110A and the release liner 130 are bonded together, the sheet substrate 110A is The release liner 130 has a relatively flat surface compared to the uneven surface 131 of the sheet substrate. The base material layer 110 is formed by bonding the material 110A and the release liner 130 together. The base layer 110 may deform to fit the uneven shape 131 of the release liner 130 .

[0037] Specifically, in the pressure-sensitive adhesive sheet 100 of this embodiment, the release liner 130 is provided with the protrusions 132. At the locations where the layers are cut, the surface 111 of the base layer 110 is convex, and the areas between the convexities are concave. The deformation of the surface 111 is not limited to the shape disclosed in this embodiment. First, it differs depending on the uneven shape 131 of the release liner 130.

[0038] Such deformation occurring in the base layer 110 occurs when the surface 111 is highly glossy, unlike in this embodiment. As a result, the uneven shape 131 of the release liner 130 is visible on the surface of the adhesive sheet 100. More specifically, if the surface 111 is highly glossy, the A similar mesh pattern to that shown may also be visible on the surface of the adhesive sheet 100.

[0039] On the other hand, in this embodiment, the surface 111 is measured in accordance with JIS Z 8741. The 60-degree specular gloss is 30% or less, so the gloss is suppressed, and the release liner 13 Even if the base layer 110 is deformed in accordance with the uneven shape 131 of the substrate 110, such deformation is not noticeable. It is difficult to adhere the release liner 130 to the surface of the adhesive sheet 100, so that the uneven shape 131 of the release liner 130 stands out. This can prevent the image from being seen by others.

[0040] In addition, the depressions 121 formed in the adhesive layer 120 form a surface of the adhesive layer 120. Specifically, in the above embodiment, the same mesh pattern as shown in FIG. 3 is formed on the base material layer 110. If it is visible from the side, the appearance of the adhesive sheet 100 may be marred.

[0041] However, in this embodiment, the colored base layer 110 is adhesive from the base layer 110 side. In order to block the visibility of the adhesive layer 120, the surface of the adhesive layer 120 is patterned with recesses 121. Even if a pattern is formed, such a pattern cannot be seen through the base layer 110 side, and the adhesive sheet 100% appearance can be prevented from being damaged.

[0042] In this embodiment, the protrusions 132 extend in the surface direction, and are therefore transferred in an inverted manner. The recesses 121 are formed in the shape of grooves extending in the surface direction of the adhesive layer 120. When the adhesive sheet 100 is attached to the adherend, air that is present between the adherend and the adhesive layer 120 However, since the pressure-sensitive adhesive sheet 100 is smoothly released in the surface direction, the pressure-sensitive adhesive sheet 100 can be prevented from swelling according to this embodiment. can be effectively suppressed.

[0043] Next, an example will be described.

[0044] <Example> The present inventors actually produced pressure-sensitive adhesive sheets of Examples 1 to 3 according to the above embodiment. For comparison, PSA sheets of Comparative Examples 1 to 3 were also prepared. It was confirmed whether the uneven shape of the adhesive sheet was visible as if it stood out on the surface of the adhesive sheet.

[0045] The pressure-sensitive adhesive sheets of Examples 1 to 3 and Comparative Examples 1 to 3 each comprise a substrate layer, a pressure-sensitive adhesive layer, and and a release liner are laminated in this order. For the adhesive sheet of 3, the 60 degree angle measured on the surface of the base layer in accordance with JIS Z 8741 The specular glossiness is different for each product. Measurements were taken using a VG7000 meter.

[0046] The release liner used in the examples and comparative examples had a polyethylene layer on the surface of a paper substrate. The surface on which the polyethylene layer is provided is embossed with In this uneven shape, the concave and convex portions of the release liner 130 shown in FIG. The dimensions of the convex shape 131 are as follows: the height L1 of the convex (or the depth of the concave) is 10 μm; The width L2 is 65 μm, and the interval L3 between the protrusions is 600 μm.

[0047] The surface of the release liner on which the uneven surface was formed was coated with a coating amount of 25 g / m 2 Sticky The adhesive composition was applied to form a pressure-sensitive adhesive layer having a thickness of about 23 μm. The base layers of the adhesive sheets are all made of polyvinyl chloride. The base layer of the adhesive sheets of Comparative Examples 1 and 2 had a thickness of 50 μm, and the adhesive sheet of Comparative Example 3 The base layer of the sheet has a thickness of 80 μm.

[0048] The present inventors have prepared a sheet of a release liner coated with a pressure-sensitive adhesive composition and a base sheet for a base layer. The adhesive sheet was then stored at 23°C for 24 hours, and the adhesive sheet was then When observed from the side, the uneven shape of the release liner is visible as if it is raised on the surface of the adhesive sheet. The evaluation results are shown in Table 1 below.

[0049] [Table 1]

[0050] In the evaluation results in Table 1, ⊚ indicates that the effect of preventing the unevenness of the release liner from being seen is particularly excellent. A indicates that the effect is good, and a indicates that the uneven shape of the release liner is not good enough to prevent adhesion. This indicates that the mark is visible as if it is raised on the surface of the attached sheet.

[0051] As shown in Table 1, the PSA sheets of Comparative Examples 2 and 3, which have a high specular gloss and a strong surface gloss, In the case of the adhesive sheet, the uneven shape of the release liner is visually recognized as being raised on the surface of the adhesive sheet, as shown in Figure 3. A mesh pattern similar to the above was observed on the surface of the adhesive sheet.

[0052] On the other hand, in the PSA sheet of Comparative Example 1, which has a relatively low gloss, the uneven shape of the release liner is Unlike Examples 2 and 3, it was not clearly visible, and the impact on the appearance was minimized.

[0053] Furthermore, in Examples 1 to 3, which had a low specular gloss and a more suppressed gloss, The unevenness of the release liner is not visible on the surface, and the original appearance of the PSA sheet is maintained in good condition. It was drooping.

[0054] For these reasons, we have decided to suppress the gloss so that the specular gloss of the surface of the adhesive sheet is below a specified value. By doing so, the uneven shape of the release liner is visually recognized as if it stands out on the surface of the adhesive sheet. It was confirmed that this can prevent the

[0055] The present invention is not limited to the above-described embodiments and examples, and is not limited to the scope of the claims. For example, the adhesive sheet 100 of the above embodiment may be made up of a base material layer 110, an adhesive layer 112, and a The adhesive layer 120 and the release liner 130 are laminated together. Further embodiments are also included within the scope of the present invention.

[0056] The shape of the adhesive sheet is not particularly limited, and may be, for example, a long shape, a rectangular shape, or a circular shape. It may be a square, oval, or other shape, or may be shaped like the outline of a letter or character. It may also have an irregular shape. [Explanation of symbols]

[0057] 100 adhesive sheets, 110 base material layer, 110A sheet substrate, 111 One surface of the adhesive sheet on the base layer side, 111A sheet substrate surface; 120 adhesive layer, 120A adhesive composition, 121 recesses, 130 release liner, 131 Uneven shape, 132 Protrusion.

Claims

1. The adhesive sheet has a base layer, a pressure-sensitive adhesive layer, and a release liner in this order in the lamination direction, and the release liner a pressure-sensitive adhesive sheet having a concave-convex shape formed on the surface of the core facing the pressure-sensitive adhesive layer, The 60-degree specular gloss measured on one surface of the substrate layer side in accordance with JIS Z 8741 The adhesive sheet has a degree of adhesion of 30% or less.

2. The colored base layer prevents the pressure-sensitive adhesive layer from being viewed from the base layer side. The pressure-sensitive adhesive sheet according to claim 1.

3. the uneven shape of the release liner is formed by protrusions extending in a surface direction; The pressure-sensitive adhesive sheet according to claim 1 or 2.

4. A surface with a 60-degree specular gloss of 30% or less as measured in accordance with JIS Z 8741 and preparing a sheet substrate having the following: preparing a release liner having a textured surface; a pressure-sensitive adhesive composition is applied to at least one of the sheet substrate and the release liner; The sheet substrate and the release liner are bonded together, When laminating the materials, The sheet substrate has a 60-degree specular gloss of 30% or less on at least one of both surfaces. the surface facing away from the release liner, The release liner has a surface on which the concave and convex shapes are formed facing the sheet substrate. A method for manufacturing adhesive sheets.

5. The sheet substrate is colored to prevent visibility from one side to the other side, The method for producing a pressure-sensitive adhesive sheet according to claim 4.

6. The release liner is used, in which the uneven shape is formed by protrusions extending in the surface direction. The method for producing a pressure-sensitive adhesive sheet according to claim 4 or 5.

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