JP4641631B2 - Release sheet material for pressure-sensitive adhesive sheet and pressure-sensitive adhesive sheet having the release sheet material - Google Patents

Description

【００５６】
表１より、実施例に係る剥離シート材を有する偏光フィルムは、糸曳き性およびタック性が優れている。従って、加工品同士による汚染が抑制又は防止されており、切断加工性が良好である。なお、実施例に係る剥離シート材は、特定の破断伸度を有するプラスチックフィルム層（Ｂ層）を剥離剤層（Ａ層）とプラスチックフィルム層（Ｃ層）との間に有しているので、該剥離シート材を有する感圧性接着剤シートを切断すると、Ｂ層が切断時に変形を起こして、粘着剤層の切断面を一部又は全部覆うことにより、糸曳き性およびタック性などが優れていると思われる。
【００５７】
一方、比較例に係る剥離シート材を有する偏光フィルムは、糸曳き性及び／又はタック性が良好でなく、ひいては切断加工性が低い。そのため、製品加工時には、加工品同士の汚染が生じると思われる。
【図面の簡単な説明】
【図１】本発明の剥離シート材の一例を示す概略断面図である。
【図２】本発明の剥離シート材を有する感圧性接着シートの一例を示す概略断面図である。
【図３】本発明の剥離シート材を有する感圧性接着シートの他の例を示す概略断面図である。
【図４】従来の剥離シート材を有する偏光フィルムを示す概略断面図である。
【図５】本発明の剥離シート材を有する感圧性接着シートの切断面の拡大写真を示す図である。
【符号の説明】
１ 剥離剤層（Ａ層）
２ 高破断伸度プラスチックフィルム層（Ｂ層）
３ プラスチックフィルム層（Ｃ層）
４ 剥離シート材
７ 偏光板層
８ 粘着剤層
９ 剥離ライナー層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a release sheet material for a pressure-sensitive adhesive sheet capable of imparting excellent cutting processability and punching processability, and a pressure-sensitive adhesive sheet having the release sheet material.
[0002]
[Prior art]
Conventionally, pressure-sensitive adhesive sheets are used in a wide variety of fields, not only for nameplate fixing, automobile interior parts, office work, and general households, but also in the fields of optical materials, electronic materials, and electrical materials. ing. Along with this, products are often cut into various sizes and shapes or punched into products. In such a pressure-sensitive adhesive sheet, the pressure-sensitive adhesive layer is formed of a viscoelastic body having fluidity to wet the adherend. Therefore, contamination due to adhesion of viscoelastic body to cutting blades and punching blades, blocking of cut workpieces, sticking of adhesive layer, contamination of workpieces cut and punched, etc. occur There is a case. These cause deterioration of workability such as cutting workability and punching workability. In particular, in the optical material field, the electronic material field, and the electrical material field, smoothness and heat resistance of the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet are required. Therefore, a release sheet obtained by applying a release agent to a plastic film is often used. However, it is very sensitive to the contamination of LCD, electronic and electrical parts by the adhesive layer because it leads to product defects. At present, in these fields, the pressure-sensitive adhesive sheet is cut and punched into a complicated and small shape, and defects due to cutting and punching are more likely to occur.
[0003]
Therefore, by limiting the material of the pressure-sensitive adhesive layer or its characteristics, cutting workability and punching workability can also be improved, but in this case, the surface to be bonded and the application are limited or the cost is increased. There is a case.
[0004]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a pressure-sensitive adhesive sheet having a release sheet material for pressure-sensitive adhesive sheet that can provide excellent cutting processability and punching processability, and a pressure-sensitive adhesive sheet having the release sheet material. It is to provide.
Another object of the present invention is to provide a pressure-sensitive adhesive sheet having a release sheet material that can exhibit excellent cutting processability and punching processability regardless of the material of the adhesive layer.
[0005]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have peeled off a release sheet material (release liner layer) in a pressure-sensitive adhesive sheet from a plastic film layer of a laminate obtained by applying a release agent to a conventional plastic film. It has been found that when a plastic film layer having a specific elongation at break is provided between the agent layer and the workability and the workability are improved, the present invention has been completed.
[0006]
That is, this invention is a release sheet material for pressure-sensitive adhesive sheets laminated | stacked in order of the following A layer, B layer, and C layer at least.
A layer: Release agent layer
B layer: a plastic film layer having a breaking elongation of 200 to 1200%
C layer: Breaking elongation is smaller than B layer Plastic film layer
[0007]
Moreover, the pressure sensitive adhesive sheet which has the said peeling sheet material for pressure sensitive adhesive sheets is also contained in this invention.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings as necessary. In addition, the same code | symbol is attached | subjected to the same member and part.
[0009]
[Peeling sheet material]
FIG. 1 is a schematic sectional view showing an example of a release sheet material for a pressure-sensitive adhesive sheet of the present invention. In FIG. 1, 1 is a release agent layer (A layer), 2 is a plastic film layer having a specific breaking elongation (hereinafter sometimes referred to as “high breaking elongation plastic film layer”) (B layer), 3 A plastic film layer (C layer) and 4 is a release sheet material. In this example, the release sheet material 4 has a three-layer structure in which a high breaking elongation plastic film layer 2 is provided between a release agent layer 1 and a plastic film layer 3.
[0010]
(B layer: high breaking elongation plastic film layer)
The high breaking elongation plastic film layer 2 is formed of a plastic film having a breaking elongation of 200 to 1200% (preferably 300 to 1100%, more preferably 400 to 1000%). When the rupture elongation of the plastic film forming the high rupture elongation plastic film layer 2 is less than 200%, the deformability of the high rupture elongation plastic film layer 2 is lowered during processing, so that the cutting workability and the punching workability are reduced. Decreases. On the other hand, when the breaking elongation exceeds 1200%, the deformability of the high breaking elongation plastic film layer 2 at the time of processing is too large, and it becomes easy to get entangled with the cutting blade, and the cutting workability and the punching workability are lowered.
[0011]
The breaking elongation of the plastic film of the high breaking elongation plastic film layer 2 can be measured according to JIS K 6760.
[0012]
The material of the plastic film of the high breaking elongation plastic film layer 2 is not particularly limited as long as it is a resin having the breaking elongation. Examples of the material of the plastic film include ethylene resins such as polyethylene (low density polyethylene, linear low density polyethylene, high density polyethylene, etc.), olefin resins such as poly-4-methyl-1-pentene; nylon 6, amide resins such as nylon 6,6, partially aromatic polyamide; vinyl chloride resins such as soft polyvinyl chloride; vinylidene chloride resins such as polyvinylidene chloride. As the material of the film, an olefin resin (especially an ethylene resin) is preferable. The plastic film material can be used alone or in admixture of two or more resins.
[0013]
In the high breaking elongation plastic film layer 2, the breaking elongation is, for example, the type of resin component constituting the plastic film layer, the type of additive component such as a filler blended with the resin component, and the content thereof, Or it can adjust to the specific range (for example, 200-1200%) prescribed | regulated by this invention by selecting suitably the film-forming conditions of a plastic film layer, etc.
[0014]
The thickness of the high breaking elongation plastic film layer 2 is not particularly limited, and can be selected, for example, from a range of about 1 to 1000 μm, preferably 5 to 300 μm, and more preferably about 10 to 100 μm.
[0015]
(A layer: release agent layer)
The release agent layer 1 is formed of a release agent. The release agent is not particularly limited as long as it can exhibit a release function or a release function. Specifically, examples of the release agent include silicone release agents, fluorine release agents, long chain alkyl acrylate release agents, long chain alkyl-modified polymer release agents, and the like. Especially, as a release agent, a silicone type release agent is preferable.
[0016]
The release agents can be used alone or in combination of two or more. The release agent can be used in the form of an emulsion, a form dissolved with a solvent, a form without solvent, and the like.
[0017]
The thickness of the release agent layer 1 is not particularly limited, but is usually about 0.01 to 5 μm.
[0018]
(C layer: plastic film layer)
The plastic film layer 3 constituting the C layer is laminated together with the above-described high breaking elongation plastic film layer (B layer: 2) and the release agent layer (A layer: 1) to form a base material layer (support) of the release sheet material. It is a layer that functions as a body. The plastic material constituting the plastic film layer (C layer: 3) is not particularly limited as long as it is usually a plastic material used as a base material for a release sheet material. Examples of such plastic materials include ester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene nitrate; hard polyvinyl chloride; propylene resins such as polypropylene, and the like. Above all, from the viewpoint of little dimensional change with respect to (tensile) tension applied during the production of release sheet materials and pressure-sensitive adhesive sheets, and good heat resistance, ester systems such as polyethylene terephthalate Resins are preferred. Further, the plastic film layer constituting the C layer preferably has a smaller breaking elongation than the high breaking elongation plastic film layer constituting the B layer. Specifically, the breaking elongation is 0 to 500%. Preferably there is. By adopting such a configuration, the insertion of the blade at the time of cutting is stable, the deformation of the B layer is effectively expressed, and the cutting workability and punching workability are improved.
[0019]
Moreover, the plastic material which comprises a plastic film layer (C layer: 3) can also mix and use 2 or more types of different resin.
[0020]
The thickness of the plastic film layer (C layer: 3) is not particularly limited. For example, it can select from the range of about 5-1000 micrometers.
[0021]
In the release sheet material of the present invention, since the C layer functioning as a base material layer is composed of a plastic film, for example, a pressure-sensitive adhesive sheet using a release sheet material compared to a release sheet material based on paper. There is an effect that fine fibrous materials such as paper powder are not generated when punching.
[0022]
The release sheet material of the present invention only needs to have a laminated structure composed of at least the three layers (A layer, B layer, C layer), and may have a layer structure of four or more layers. For example, the high breaking elongation plastic film layer (B layer) and the plastic film layer (C layer) may be composed of a plurality of layers. The total thickness of the release sheet material can be appropriately selected within a range that does not impair the strength, handleability, and the like, but is generally about 10 to 500 μm.
[0023]
It does not specifically limit as a manufacturing method of the peeling sheet material of this invention, A various method is employable. For example, a method in which the B layer and the C layer are laminated and extruded by a multilayer (co) extrusion method, and then the release agent layer A is applied to the surface of the B layer, or the B layer and the C layer are formed separately. Examples thereof include a method in which the B layer and the C layer are laminated by a means such as an adhesive or heat bonding, and then the release agent layer A is applied to the surface of the B layer.
[0024]
According to the release sheet material of the present invention, a plastic film layer (B layer) having a specific breaking elongation is provided between the release agent layer (A layer) and the plastic film layer (C layer). When the pressure-sensitive adhesive sheet having the release sheet material is cut or punched, the B layer is deformed at the time of cutting or punching, and the cut surface of the pressure-sensitive adhesive layer (adhesive layer) is at least partially By covering (partially or entirely), it is possible to suppress or prevent the pressure-sensitive adhesive layer from being exposed on the cut surface or the punched surface after the processing by cutting or punching. Therefore, adhesion of the adhesive to the processing blade (cutting processing blade, punching processing blade), blocking of the cut workpieces, contamination of the cut or punched workpieces can be reduced. That is, the release sheet material of the present invention can impart excellent cutting processability and punching processability to the pressure-sensitive adhesive sheet, thereby improving workability. Therefore, the release sheet material of the present invention can be suitably used as a release layer of a pressure-sensitive adhesive sheet in the optical material field, electronic material field, and electrical material field.
[0025]
In the release sheet material of the present invention, the peel force on the pressure-sensitive adhesive surface (pressure-sensitive adhesive layer surface) of the pressure-sensitive adhesive sheet is not particularly limited, but is about 0.05 to 10 N / 50 mm at 180 ° peel and 300 mm / min. It is preferable that
[0026]
[Pressure-sensitive adhesive sheet]
FIG. 2 is a schematic sectional view showing an example of the pressure-sensitive adhesive sheet of the present invention. FIG. 3 is a schematic cross-sectional view showing another example of the pressure-sensitive adhesive sheet of the present invention. 2 and / or 3, 5 is a pressure-sensitive adhesive layer (pressure-sensitive adhesive layer), and 6 is a substrate.
[0027]
In the example of FIG. 2, the pressure-sensitive adhesive sheet is formed by peeling each of two release sheet materials 4 (release liner layers) composed of a release agent layer 1, a high breaking elongation plastic film layer 2, and a plastic film layer 3. The surface (outer surface) on the side of the agent layer 1 is configured to be bonded to the surface of the pressure-sensitive adhesive layer 5. In the example of FIG. 3, the pressure-sensitive adhesive sheet is composed of two release sheet materials 4 (release liner layers) composed of a release agent layer 1, a high breaking elongation plastic film layer 2, and a plastic film layer 3. The surface on each release agent layer 1 side is configured to be bonded to each surface of the pressure-sensitive adhesive layer 5 formed on both sides of the substrate 6. These pressure-sensitive adhesive sheets shown in FIG. 2 or 3 are used as a double-sided pressure-sensitive adhesive tape or sheet, and are used by peeling off the release sheet material 4 (release liner layer).
[0028]
The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 5 is not particularly limited, and various types of pressure-sensitive adhesives such as rubber and acrylic can be used, but the amount of impurity ions contained in the pressure-sensitive adhesive is small. In particular, an acrylic adhesive is preferable.
[0029]
The acrylic pressure-sensitive adhesive is mainly composed of an acrylic polymer obtained by a conventional polymerization method. If necessary, various additives such as a crosslinking agent, a tackifier, a softening agent, an anti-aging agent and a filler are added. Can be prepared.
[0030]
As the acrylic polymer, for example, a copolymer of a monomer mixture in which (meth) acrylic acid alkyl ester is a main component and a copolymerizable monoethylenically unsaturated monomer is added as necessary is used. . When a monoethylenically unsaturated monomer is used as a comonomer, a functional group or a polar group is introduced, and heat resistance and adhesiveness can be improved and modified.
[0031]
Examples of (meth) acrylic acid alkyl esters include ethyl (meth) acrylate, butyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and isooctyl (meth) acrylate. (Meth) acrylic acid alkyl esters having about 2 to 12 carbon atoms in the alkyl moiety such as isononyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, and the like. These (meth) acrylic acid alkyl esters can be used alone or in combination.
[0032]
Examples of the monoethylenically unsaturated monomer include carboxyl group-containing monomers such as acrylic acid and itaconic acid; sulfo group-containing monomers such as sulfopropyl (meth) acrylate; hydroxyalkyl (meth) acrylate and the like Hydroxyl group-containing monomers; cyano group-containing monomers such as cyanoalkyl (meth) acrylate and acrylonitrile; amide group-containing monomers such as acrylamide, substituted acrylamide and N-vinylcaprolactam; glycidyl groups such as glycidyl acrylate Containing monomers; alkoxyalkyl (meth) acrylates such as 2-methoxyethyl acrylate; vinyl esters such as vinyl acetate; styrene monomers such as styrene. These monomers can be used alone or in combination of two or more depending on the purpose.
[0033]
The polymerization method of the acrylic polymer is arbitrary, and for example, an appropriate method such as an addition polymerization method such as a solution polymerization method, an emulsion polymerization method, a photopolymerization method using an electron beam or ultraviolet rays, or a combination method thereof can be adopted. .
[0034]
The thickness of the pressure-sensitive adhesive layer 5 can be appropriately selected in consideration of tackiness and the like, and is, for example, about 1 to 200 μm, preferably about 30 to 150 μm.
[0035]
Examples of the substrate 6 include plastic films such as polyester, polypropylene, polystyrene, and polyvinyl chloride; metal foils such as aluminum foil and stainless steel foil; paper such as kraft paper, fine paper, and crepe paper; Although the thickness of the base material 6 can be suitably selected in consideration of handling properties and the like, it is generally about 5 to 300 μm, preferably about 30 to 200 μm.
[0036]
The pressure-sensitive adhesive sheet of the present invention can be produced by a conventional film lamination method (for example, a coating method).
[0037]
For example, in the pressure-sensitive adhesive sheet of FIG. 2, a pressure-sensitive adhesive is applied to the surface of the release agent layer 1 of one release sheet material 4, dried, and cross-linked as necessary, and the pressure-sensitive adhesive layer 5. And the surface of the pressure-sensitive adhesive layer 5 is bonded to the surface of the other release sheet material 4 on the release agent layer 1 side.
[0038]
In addition, the pressure-sensitive adhesive sheet of FIG. 2 is coated with a pressure-sensitive adhesive on a film (separator) such as a polyethylene terephthalate film whose surface is silicone-treated, dried, and cross-linked as necessary to form a pressure-sensitive adhesive layer 5. After the surface of the pressure-sensitive adhesive layer 5 is bonded to the surface of the release sheet material 4 on the release agent layer 1 side, the separator is peeled off to expose the exposed pressure-sensitive adhesive layer 5 surface. It can also be manufactured by bonding the release agent layer 1 side of another release sheet material 4 together. The pressure-sensitive adhesive sheet thus obtained is used as a base sheet-less pressure-sensitive adhesive sheet using a release sheet material. This method is used when it is desired to avoid the gas generated when the pressure-sensitive adhesive layer 5 is heated and dried from adhering to the release sheet material and remaining on the pressure-sensitive adhesive sheet as it is or when excessive heat is applied to the release sheet material. This is useful when you do not want to give
[0039]
In the pressure-sensitive adhesive sheet of FIG. 3, for example, a pressure-sensitive adhesive is applied to one surface of the substrate 6 and dried, and then crosslinked as necessary to form the pressure-sensitive adhesive layer 5. After the surface of the release agent layer 5 on the release agent layer 1 side of the release sheet material 4 is bonded, the pressure-sensitive adhesive layer 5 is formed on the other surface of the substrate 6 in the same manner. The surface of the pressure-sensitive adhesive layer 5 can be manufactured by bonding the surface of the other release sheet material 4 on the release agent layer 1 side.
[0040]
The pressure-sensitive adhesive sheet of the present invention may be a single-sided pressure-sensitive adhesive tape or sheet having a pressure-sensitive adhesive layer only on one side. Such a single-sided pressure-sensitive adhesive tape or sheet is formed by, for example, applying a pressure-sensitive adhesive to one surface of the substrate 6, drying, and cross-linking as necessary to form the pressure-sensitive adhesive layer 5. It can be manufactured by bonding the surface of the release sheet material 4 on the release agent layer 1 side to the surface of the adhesive layer 5.
[0041]
FIG. 5 is an enlarged photograph of the cut surface of the pressure-sensitive adhesive sheet (polarizing film) having the release sheet material of the present invention. Specifically, a sample in which the release sheet material of the present invention was pasted on the pressure-sensitive adhesive layer surface of a polarizing film having a pressure-sensitive adhesive layer on one side, a Thomson blade (trade name “MIR23” manufactured by Nakayama Corporation, It is a figure which shows the enlarged photograph (magnification: 500 times) which looked at the cut surface after cutting | disconnecting by the blade edge angle 30 degrees) from the horizontal direction. In the photograph of FIG. 5, the right side is a cut surface. As can be seen from FIG. 5, it can be seen that the end portion on the cut surface side of the B layer constituting the release sheet material is stretched during the cutting process and covers the cut surface of the pressure-sensitive adhesive layer. In addition, the structure of the peeling sheet material used in FIG. 5 is as follows.
Layer A (release agent layer): 10% by weight of silicone (trade name “KS-778” manufactured by Shin-Etsu Chemical Co., Ltd.), 0.2% by weight of curing agent (trade name “PL-50T” manufactured by Shin-Etsu Chemical Co., Ltd.) And a silicone-based release agent comprising 89.8% by weight of toluene
B layer (high breaking elongation plastic film layer): polyethylene resin (trade name “205” manufactured by Tosoh Corporation, thickness 50 μm)
C layer (plastic film layer): polyethylene terephthalate (trade name “Lumirror S-27” manufactured by Toray Industries, Inc., thickness 38 μm)
[0042]
According to the pressure-sensitive adhesive sheet of the present invention, regardless of the material of the adhesive layer (that is, without using a specific pressure-sensitive adhesive), the pressure-sensitive adhesive (viscoelastic body) of the pressure-sensitive adhesive layer. However, it is suppressed or prevented from adhering to the processing blade during processing such as cutting or punching. Further, after processing, blocking between the processed products cut and processed, sticking of the adhesive in the pressure-sensitive adhesive layer, and contamination between the processed products cut and punched are suppressed or prevented. Accordingly, workability such as cutting workability and punching workability is excellent, and workability is improved. Therefore, the pressure-sensitive adhesive sheet of the present invention is suitable as a pressure-sensitive adhesive sheet or tape in the fields of optical materials, electronic materials, and electric materials.
[0043]
Further, in the pressure-sensitive adhesive sheet of the present invention, there is no limitation on the pressure-sensitive adhesive, and therefore, the adherend in the optical material field, the electronic material field, and the electric material field is not particularly limited, and various adherends can be used. Can be used.
[0044]
Furthermore, in the present invention, as described above, only the release sheet material having a specific configuration is used, and the cost can be reduced.
[0045]
【The invention's effect】
According to the release sheet material of the present invention, it is possible to impart excellent cutting processability and punching processability to the pressure-sensitive adhesive sheet. Therefore, a pressure-sensitive adhesive sheet having excellent cutting processability and punching processability can be obtained without using a specific pressure-sensitive adhesive.
[0046]
【Example】
Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. The elongation at break of the B layer and the like is a measured value measured according to JIS K 6760.
[0047]
Example 1
A release sheet material according to Example 1 (sometimes referred to as “release liner A”) was produced by the following method using the following materials or raw materials.
Materials used for layer A: Silicone (trade name “KS-778” manufactured by Shin-Etsu Chemical Co., Ltd.) 10% by weight, curing agent (trade name “PL-50T” manufactured by Shin-Etsu Chemical Co., Ltd.) 0.2% by weight, And a silicone release agent comprising 89.8% by weight of toluene
Material used for layer B: Polyethylene resin (trade name “LW04” manufactured by Tosoh Corporation)
Material used for layer C: Polyethylene terephthalate film (trade name “Lumirror S-27” manufactured by Toray Industries, Inc., thickness 38 μm)
A urethane-based anchor coating agent was applied to one side of the polyethylene terephthalate film (C layer) with a gravure coater so that the coating thickness after drying was 0.1 μm, and dried at 80 ° C. On this anchor coat layer, a polyethylene resin layer (B layer) having a thickness of 40 μm was formed by extrusion lamination. Further, a silicone release agent was applied to the surface of the polyethylene resin using a Meyer bar (# 12) and dried at 110 ° C. for 40 seconds to form a release agent layer (A layer) having a thickness of 1 μm. A release sheet material was prepared. The breaking elongation of the polyethylene resin layer constituting the B layer was 400%.
After peeling off the release sheet material (release liner) used in the polarizing film (NPF-SEG1425ADU, manufactured by Nitto Denko Corporation), the release liner A is bonded again and the polarizing film (optical) having the release liner A Film).
[0048]
Example 2
When the release sheet material (referred to as “release liner B”) according to Example 2 is used in the same manner as Example 1 except that the material used for the B layer is changed to polyethylene resin (trade name “205” manufactured by Tosoh Corporation). There is). The breaking elongation of the polyethylene resin layer constituting the B layer was 600%.
Further, a polarizing film having the release liner B was produced in the same manner as in Example 1 except that the release liner B was used.
[0049]
The material used for the B layer was changed to a polyethylene resin (trade name “205” manufactured by Tosoh Corporation), and the thickness of the B layer was changed to 60 μm. A release sheet material (sometimes referred to as “release liner C”) was prepared. The breaking elongation of the polyethylene resin layer constituting the B layer was 700%.
Further, a polarizing film having the release liner C was produced in the same manner as in Example 1 except that the release liner C was used.
[0050]
Comparative Example 1
A silicone release agent similar to Example 1 was applied to one side of a polyethylene terephthalate film (trade name “Lumirror S-27” manufactured by Toray Industries, Inc., thickness 38 μm) at a thickness of 1 μm, and a release sheet material (“release liner” D ").
Further, a polarizing film having the release liner D was produced in the same manner as in Example 1 except that the release liner D was used.
[0051]
The polarizing film having the trade name “NPF-SEG1425ADU (manufactured by Nitto Denko Corporation)” has a configuration as shown in FIG. 4, that is, a polarizing plate 7, an adhesive layer 8, and a release liner layer 9. In this order, the layers are stacked. Therefore, the polarizing film (polarizing film having release liners A to D) according to the examples and comparative examples has a configuration in which the release liner 9 in FIG. 4 is changed to the release liners produced in the examples and comparative examples. Yes.
[0052]
Evaluation test
The polarizing films according to Examples 1 to 3 and Comparative Example 1 were cut to a size of 30 mm × 40 mm with a Thomson blade (trade name “MIR23” manufactured by Nakayama Co., Ltd., blade angle 30 °), The stringing property (blocking property) and the tack property (stickiness) of the cut surface, which occurred during take-up, were examined, and the cutting processability was evaluated. The evaluation results of the stringiness and tackiness are shown in the “stringage” and “tackiness” columns of Table 1, respectively.
[0053]
(Method for evaluating stringiness)
After the polarizing film was cut under the above-mentioned conditions, when the residue was removed from the cut 30 mm × 40 mm portion, the generated stringiness was evaluated according to the following stringiness evaluation criteria. The evaluation of the stringiness can be used as an index of contamination between processed products.
Evaluation of stringiness
○: Level at which no stringing occurs
Δ: Level at which stringing is slightly observed
×: Level at which significant stringing is observed
[0054]
(Tackiness evaluation method)
Using a polyethylene terephthalate film (PET film) as an adherend, the tackiness (stickiness) generated when the cut surface of 30 mm × 40 mm is pressed and then separated is measured by a sensory test. It was evaluated by. In addition, evaluation of tackiness can be used as an index of contamination between processed products.
Evaluation criteria for tackiness
○: The tackiness is not felt at all, and the PET film is not lifted at all.
Δ: A level of tackiness is felt and the PET film is lifted up
X: A level at which tackiness is greatly felt and the PET film is lifted
[0055]
[Table 1]

[0056]
From Table 1, the polarizing film which has the peeling sheet material which concerns on an Example is excellent in stringing property and tack property. Therefore, the contamination by processed goods is suppressed or prevented and cutting workability is favorable. In addition, since the release sheet material which concerns on an Example has a plastic film layer (B layer) which has specific breaking elongation between a release agent layer (A layer) and a plastic film layer (C layer). When the pressure-sensitive adhesive sheet having the release sheet material is cut, the layer B is deformed at the time of cutting, and covers part or all of the cut surface of the pressure-sensitive adhesive layer, so that the stringiness and tackiness are excellent. It seems that
[0057]
On the other hand, the polarizing film having the release sheet material according to the comparative example does not have good stringiness and / or tackiness and consequently has low cutting workability. For this reason, it is considered that the processed products are contaminated during product processing.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an example of a release sheet material of the present invention.
FIG. 2 is a schematic cross-sectional view showing an example of a pressure-sensitive adhesive sheet having the release sheet material of the present invention.
FIG. 3 is a schematic cross-sectional view showing another example of a pressure-sensitive adhesive sheet having the release sheet material of the present invention.
FIG. 4 is a schematic cross-sectional view showing a polarizing film having a conventional release sheet material.
FIG. 5 is an enlarged photograph of a cut surface of a pressure-sensitive adhesive sheet having a release sheet material of the present invention.
[Explanation of symbols]
1 Release agent layer (A layer)
2 High breaking elongation plastic film layer (B layer)
3 Plastic film layer (C layer)
4 Release sheet material
7 Polarizer layer
8 Adhesive layer
9 Release liner layer

Claims (4)

A release sheet material for a pressure-sensitive adhesive sheet, which is laminated in the order of at least the following A layer, B layer, and C layer.
A layer: Release agent layer B layer: Plastic film layer having a breaking elongation of 200 to 1200% C layer: Plastic film layer having a smaller breaking elongation than B layer   The release sheet for a pressure-sensitive adhesive sheet according to claim 1, wherein the material of the plastic film of layer B is at least one thermoplastic resin selected from olefin resins, amide resins, vinyl chloride resins, and vinylidene chloride resins. Wood.   A pressure-sensitive adhesive sheet comprising the release sheet material for a pressure-sensitive adhesive sheet according to claim 1 or 2.   The pressure-sensitive adhesive sheet according to claim 3, wherein the layer B of the release sheet material can partially cover the cut surface of the pressure-sensitive adhesive layer after the pressure-sensitive adhesive sheet is cut or punched.

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