JP2019052280A - Adhesive sheet - Google Patents

Abstract

To provide an adhesive sheet which has excellent adhesive force to a polyolefin resin member having a rough surface.SOLUTION: An adhesive sheet is an adhesive sheet having an adhesive layer formed from an adhesive composition containing one or more styrene resins (A) selected from a styrene-isoprene diblock copolymer (SI) and a styrene-isoprene-styrene triblock copolymer (SIS) and a tackifier resin (B), where a thickness of the adhesive layer is 15 μm or more, and an adhesive force of a polypropylene plate having a rough surface with arithmetic average roughness Ra of 1.0-3.0 μm to the rough surface is 8.0 N/25 mm or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an adhesive sheet.

Conventionally, pressure-sensitive adhesive sheets have been widely used for joining various members.
As the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet, various pressure-sensitive adhesives such as acrylic, silicone, rubber, and urethane are used.
For example, Patent Document 1 discloses a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer obtained by crosslinking a pressure-sensitive adhesive composition made of an acrylic polymer composed of a predetermined monomer together with acrylic (meth) acrylate. According to Patent Document 1, the pressure-sensitive adhesive sheet is said to have high adhesive strength even when the thickness of the pressure-sensitive adhesive layer is reduced to 1 to 20 μm.

Special table 2014-118485 gazette

By the way, the member containing polyolefin resin, such as polyethylene and a polypropylene, is used in various fields.
However, since the polyolefin resin has low polarity, even if an ordinary pressure-sensitive adhesive sheet is used to adhere the polyolefin resin member, the adhesive strength to the member is low and the adhesion is often insufficient.
In patent document 1, although the measurement of the adhesive force of an adhesive sheet is performed with respect to the glass surface, the measurement of the adhesive force with respect to the to-be-adhered body containing polyolefin resin is not performed.

  In addition, the surface of the polyolefin resin member is roughened and roughened by surface treatment or the like, which becomes a factor that hinders adhesion. There is a demand for a pressure-sensitive adhesive sheet that can exhibit excellent adhesive force even on such a rough surface.

  This invention is made | formed in view of the said situation, and it aims at providing the adhesive sheet which has the outstanding adhesive force with respect to the polyolefin-type resin member which has a rough surface.

  The present inventors have found that a pressure-sensitive adhesive sheet formed from a pressure-sensitive adhesive composition containing a specific styrenic resin and a tackifier resin and having a pressure-sensitive adhesive layer having a predetermined thickness can solve the above-mentioned problems. The present invention has been completed.

That is, the present invention provides the following [1] to [2].
[1] One or more styrene resins (A) selected from styrene-isoprene diblock copolymer (SI) and styrene-isoprene-styrene triblock copolymer (SIS), and tackifying resin (B) A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing
The pressure-sensitive adhesive layer has a thickness of 15 μm or more,
The adhesive sheet whose adhesive force with respect to the said rough surface of the polypropylene plate which has a rough surface whose arithmetic mean roughness Ra is 1.0-3.0 micrometers is 8.0 N / 25mm or more.
[2] The pressure-sensitive adhesive sheet according to [1], wherein the tackifying resin (B) is at least one selected from rosin-based resins, terpene-based resins, styrene-based resins, and hydrocarbon-based resins.

  The pressure-sensitive adhesive sheet of the present invention has an excellent pressure-sensitive adhesive force against a polyolefin resin member having a rough surface.

It is a cross-sectional schematic diagram of an adhesive sheet which shows an example of a structure of the adhesive sheet of this invention.

  In the present specification, “mass average molecular weight (Mw)” is a value in terms of standard polystyrene measured by gel permeation chromatography (GPC), and specifically measured based on the method described in Examples. It is the value.

[Configuration of adhesive sheet]
If the adhesive sheet of this invention has an adhesive layer, there will be no restriction | limiting in particular.
FIG. 1 is a schematic cross-sectional view of an adhesive sheet showing an example of the configuration of the adhesive sheet of the present invention.
As an adhesive sheet of 1 aspect of this invention, as shown to Fig.1 (a), the adhesive sheet 1a with a base material which has the adhesive layer 12 on the at least one surface of the base material 11 is mentioned, for example.
In addition, in the structure of the adhesive sheet 1a with a base material, as shown in FIG.1 (b), it is good also as the adhesive sheet 1b with a base material which laminated | stacked the peeling material 13 on the adhesive layer 12. FIG.

  Moreover, as an adhesive sheet of 1 aspect of this invention, as shown in FIG.1 (c), the structure like the double-sided adhesive sheet 1c with a base material which has the adhesive layers 12a and 12b on both surfaces of the base material 11, respectively. It is good. In addition, the double-sided pressure-sensitive adhesive sheet 1c shown in FIG. 1C may have a configuration in which a release material is further laminated on the pressure-sensitive adhesive layers 12a and 12b.

Moreover, as an adhesive sheet of 1 aspect of this invention, as shown in FIG.1 (d), the base | substrate which has the structure by which the adhesive layer 12 was pinched | interposed into two peeling materials 13a and 13b, without using a base material. The materialless adhesive sheet 1d may be used.
The release materials 13a and 13b of the adhesive sheet without base material 1d may be the same type of material or different types of materials, but the release force between the release material 13a and the release material 13b is different. It is preferable that the material is adjusted as described above.
In addition, as an adhesive sheet without a base material, the adhesive sheet which has the structure which wound what provided the adhesive layer on one side of the peeling material by which the peeling process was given to both surfaces was rolled is mentioned.

  The pressure-sensitive adhesive sheet shown in FIGS. 1 and 2 has a configuration in which a base material and a pressure-sensitive adhesive layer are directly laminated. However, in the pressure-sensitive adhesive sheet of one embodiment of the present invention, the base material and the pressure-sensitive adhesive are used. The structure which has another layer between layers may be sufficient.

By the way, the adhesive sheet of this invention requires that the adhesive force with respect to the said rough surface of the polypropylene plate which has a rough surface whose arithmetic mean roughness Ra is 1.0-3.0 micrometers is 8.0 N / 25mm or more.
The arithmetic average roughness Ra is a value measured according to JIS B 0601: 1994, and specifically means a value measured based on the method described in the examples.
Said adhesive force assumes the adhesive force with respect to the polyolefin-type resin member which has a rough surface generally used widely. That is, if the said adhesive force is 8.0 N / 25mm or more, it can be said that it is an adhesive sheet which can fully adhere | attach also on the rough surface of such a member.
In the pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive strength is 8.0 N / 25 mm or more, preferably 15.0 N / 25 mm or more, more preferably 20 N / 25 mm or more, still more preferably 30 N / 25 mm or more, and still more preferably. Is 40 N / 25 mm or more.
In addition, in this specification, said adhesive force means the value measured based on the method as described in an Example.

  Hereinafter, the pressure-sensitive adhesive layer, the base material, and the release material that constitute the pressure-sensitive adhesive sheet of one embodiment of the present invention will be described.

(Adhesive layer)
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention comprises at least one styrene resin (A) selected from a styrene-isoprene block copolymer (SI) and a styrene-isoprene-styrene triblock copolymer (SIS). And a layer formed from a pressure-sensitive adhesive composition containing a tackifying resin (B).
The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition containing the tackifying resin (B) together with the specific styrene-based resin (A) is a general acrylic pressure-sensitive adhesive against a polyolefin resin member having a rough surface. Compared with the case where an agent is used, high adhesive force can be expressed.

In addition, the thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention is 15 μm or more, preferably 17 μm or more, from the viewpoint of improving the adhesive force to the polyolefin resin member having a rough surface.
Moreover, from the viewpoint of obtaining a pressure-sensitive adhesive sheet with good handleability, the thickness of the pressure-sensitive adhesive layer is preferably 100 μm or less, more preferably 90 μm or less.

  The pressure-sensitive adhesive composition, which is a material for forming the pressure-sensitive adhesive layer, may contain other resin components and additives for pressure-sensitive adhesives together with the components (A) and (B) as long as the effects of the present invention are not impaired. Good.

<Styrene resin (A)>
The pressure-sensitive adhesive composition used in the present invention includes a styrene-isoprene block copolymer (SI) (hereinafter also referred to as “SI resin”) and a styrene-isoprene-styrene triblock copolymer (SIS) (hereinafter referred to as “SIS resin”). 1) or more styrene-based resin (A) selected from.
In one embodiment of the present invention, it is preferable to use an SI resin and an SIS resin in combination as the styrene resin (A).

  In one embodiment of the present invention, the SI resin content relative to the total amount (100% by mass) of the styrenic resin (A) is preferably 10 from the viewpoint of improving the adhesive force to the polyolefin resin member having a rough surface. -90 mass%, More preferably, it is 20-80 mass%, More preferably, it is 25-70 mass%.

  Moreover, in 1 aspect of this invention, as content of the structural unit derived from styrene with respect to the whole quantity (100 mass%) of the structural unit of styrene resin (A), it is the adhesive force with respect to the polyolefin-type resin member which has a rough surface. From the viewpoint of improving the viscosity, it is preferably 5 to 40% by mass, more preferably 8 to 35% by mass, and still more preferably 10 to 30% by mass.

  The mass average molecular weight (Mw) of the styrene resin (A) is preferably 10,000 to 500,000, more preferably 20,000 to 400,000, more preferably 25,000 to 350,000, and still more preferably 30,000. ~ 300,000.

In the pressure-sensitive adhesive composition used in one embodiment of the present invention, the content of the component (A) is preferably 10 to 90% by mass, more preferably 10 to 90% by mass, based on the total amount (100% by mass) of the active ingredients in the pressure-sensitive adhesive composition. Preferably it is 20-80 mass%, More preferably, it is 30-70 mass%.
In the present specification, the “active component of the pressure-sensitive adhesive composition” refers to a component obtained by removing a solvent such as water or an organic solvent from the components contained in the pressure-sensitive adhesive composition.

<Adhesive resin other than component (A)>
The pressure-sensitive adhesive composition used in one embodiment of the present invention may contain a pressure-sensitive adhesive resin having a mass average molecular weight (Mw) other than the component (A) of 10,000 or more as long as the effects of the present invention are not impaired.
Examples of such an adhesive resin include styrene resins other than the component (A), acrylic resins, urethane resins, polyisobutylene resins, and the like.

<Tackifying resin (B)>
The pressure-sensitive adhesive composition used in the present invention contains a tackifier resin (B).
In the present specification, the tackifying resin is a component that assists in improving the adhesive strength of the adhesive resin, and is an oligomer having a mass average molecular weight (Mw) of usually less than 10,000. Are distinct.
The mass average molecular weight (Mw) of the tackifier resin (B) is preferably 400 to 4000, more preferably 800 to 1500.

The tackifier resin (B) is preferably at least one selected from rosin resins, terpene resins, styrene resins, and hydrocarbon resins.
In addition, as the tackifier resin (B), a hydrogenated resin obtained by hydrogenating these resins may be used.

  Examples of the rosin resin include rosin resins, rosin ester resins, and rosin phenol resins, and may be hydrogenated rosin resins obtained by hydrogenating these resins.

  The terpene resin may be a compound having a structural unit derived from isoprene, and examples thereof include terpene resins, aromatic modified terpene resins, and terpene phenol resins, and hydrogenation of these resins by hydrogenation. A terpene resin may be used.

Examples of the styrene resin include a resin obtained by copolymerizing a styrene monomer such as α-methylstyrene or β-methylstyrene and an aliphatic monomer, and hydrogenated styrene obtained by hydrogenating the resin. A resin may be used.
The styrenic resin used as the tackifier resin (B) is a resin that does not correspond to the component (A), and can be distinguished from the component (A) at least in terms of molecular weight.

Examples of hydrocarbon resins include C5 hydrocarbon resins obtained by copolymerizing C5 fractions such as pentene, isoprene, piperine, and 1.3-pentadiene produced by the thermal decomposition of petroleum naphtha; And C9 hydrocarbon resins obtained by copolymerizing C9 fractions such as indene and vinyltoluene produced by decomposition; and hydrogenated hydrocarbon resins obtained by hydrogenating these.
The hydrocarbon resin may be any of an aliphatic hydrocarbon resin, an alicyclic hydrocarbon resin, and an aromatic hydrocarbon resin, but the aliphatic hydrocarbon resin and the alicyclic hydrocarbon resin. Is preferred.

  The softening point of the tackifier resin (B) is preferably 70 to 170 ° C., more preferably 80 to 160 ° C., from the viewpoint of improving the adhesive force to the polyolefin resin member having a rough surface.

  In addition, when using rosin-type resin as tackifying resin (B), the softening point of the said rosin-type resin becomes like this. Preferably it is 80-130 degreeC, More preferably, it is 80-110 degreeC, More preferably, it is 80-90 degreeC. .

  When a terpene resin is used as the tackifier resin (B), the softening point of the terpene resin is preferably 80 to 150 ° C, more preferably 85 to 130 ° C, and still more preferably 90 to 105 ° C.

  When a hydrocarbon resin is used as the tackifier resin (B), the softening point of the hydrocarbon resin is preferably 90 to 160 ° C, more preferably 100 to 155 ° C, still more preferably 120 to 150 ° C. .

In addition, in this specification, the softening point of tackifying resin (B) means the value measured based on JISK2531.
Moreover, when using together 2 or more types of tackifying resin, it is preferable that the value of the weighted average calculated from the softening point and compounding quantity of each tackifying resin is the said range.

  In one embodiment of the present invention, the content of the component (B) is preferably 10 to 300 parts by mass, more preferably 30 to 200 parts by mass with respect to 100 parts by mass of the total amount of the component (A) in the pressure-sensitive adhesive composition. Part, more preferably 50 to 180 parts by weight.

<Adhesive additive>
The pressure-sensitive adhesive composition used in one embodiment of the present invention may further contain a general pressure-sensitive adhesive additive as long as the effects of the present invention are not impaired.
Examples of such an adhesive additive include a crosslinking agent, a plasticizer (liquid resin, liquid paraffin, etc.), an ultraviolet absorber, an antioxidant, a rust inhibitor, an antibacterial agent, an insect repellent, a fragrance, a pigment, and a dye. , Curing agents, curing aids, catalysts and the like.

〔Base material〕
Although the base material which the adhesive sheet of 1 aspect of this invention has is suitably selected according to a use, porous base materials, such as a paper base material, a metal base material, and a nonwoven fabric, a resin film etc. are mentioned, for example.

Examples of the paper material constituting the paper base include thin paper, medium quality paper, high quality paper, impregnated paper, coated paper, art paper, sulfuric acid paper, glassine paper and the like.
As a metal which comprises a metal base material, aluminum, copper, silver, gold | metal | money etc. are mentioned, for example.

  Examples of the resin constituting the resin film include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resins such as polyethylene and polypropylene; polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, and ethylene-vinyl acetate. Vinyl resins such as copolymers and ethylene-vinyl alcohol copolymers; polystyrene; acrylonitrile-butadiene-styrene copolymers; cellulose triacetate; polycarbonate; urethane resins such as polyurethane and acrylic-modified polyurethane; polymethylpentene; Polyetheretherketone; Polyethersulfone; Polyphenylene sulfide; Polyimide resins such as polyetherimide and polyimide; Polyamide Resins, acrylic resins, fluorine-based resins.

These resin films may be composed of only one kind of resin, or may be composed of two or more kinds of resins.
The resin film may be unstretched, or may be stretched in a uniaxial direction or a biaxial direction such as longitudinal or lateral.
Further, the resin film may be a resin film having a cavity-containing layer including a cavity inside. In addition, it is good also as a resin film which laminated | stacked the resin layer which does not contain a cavity further on the at least one surface side of the said cavity content layer.
In addition, the resin film may contain various additives such as an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a slip agent, an antiblocking agent, and a colorant together with these resins.

These base materials may be used alone or in combination of two or more types.
The multilayer body used as the substrate includes a laminate substrate obtained by laminating a paper substrate with a resin, a resin film with a metal film having a metal film on the surface of the resin film, and the like.

  Examples of the laminated base material include laminated paper obtained by laminating the above paper base material with a thermoplastic resin such as polyethylene.

The metal film which a resin film with a metal film has can be formed from metals such as aluminum, tin, chromium, and titanium.
As a method of forming a metal film on the surface of a resin film, a method of depositing these metals by a PVD (physical vapor deposition) method such as vacuum deposition, sputtering, or ion plating, or a metal foil made of the above metals is generally used. The method of sticking using a typical adhesive is mentioned.

In addition, when the base material used by 1 aspect of this invention is a resin film or a laminate base material, it is an oxidation method or uneven | corrugated with respect to the surface of these base materials from a viewpoint of improving adhesiveness with an adhesive layer. Surface treatment such as chemical conversion or primer treatment may be performed.
The oxidation method is not particularly limited, and examples thereof include a corona discharge treatment method, a plasma treatment method, chromic acid oxidation (wet), flame treatment, hot air treatment, and ozone / ultraviolet irradiation treatment.
The unevenness forming method is not particularly limited, and examples thereof include a sand blast method and a solvent treatment method.

  As thickness of a base material, Preferably it is 5-1000 micrometers, More preferably, it is 10-500 micrometers, More preferably, it is 12-250 micrometers, More preferably, it is 15-150 micrometers.

[Release material]
As the release material of the pressure-sensitive adhesive sheet of one embodiment of the present invention, a release material that has been subjected to a double-sided release treatment, a release material that has been subjected to a single-side release treatment, or the like is used, and a release agent is applied on a release material base Etc.
Examples of the base material for the release material include paper base materials such as glassine paper, coated paper, high-quality paper, laminated paper obtained by laminating a thermoplastic resin such as polyethylene on these paper base materials, or polyethylene terephthalate resin, polybutylene terephthalate. Examples thereof include plastic films such as resins, polyester resin films such as polyethylene naphthalate resin, and polyolefin resin films such as polypropylene resin and polyethylene resin.
Examples of the release agent include silicone resins, olefin resins, long chain alkyl resins, alkyd resins, fluorine resins, and the like.

  The thickness of the release material is appropriately set, but is preferably 10 to 200 μm, and more preferably 25 to 150 μm.

[Method for producing adhesive sheet]
There is no restriction | limiting in particular as a manufacturing method of the adhesive sheet of this invention, The above-mentioned adhesive composition is apply | coated on a base material or a peeling material, a coating film is formed, the said coating film is dried, and an adhesive. The manufacturing method which has the process of forming a layer is mentioned.
In addition, in order to improve the workability | operativity of the application | coating on the surface of the base material or a peeling material to a base material or a peeling material, the adhesive composition of this invention which is a forming material of an adhesive layer is further with an organic solvent. It is preferable to dilute to form a solution.

Examples of the organic solvent include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, isopropanol and the like.
As solid content concentration of the solution of an adhesive composition, Preferably it is 5-70 mass%, More preferably, it is 10-65 mass%, More preferably, it is 15-60 mass%.

  Examples of the method for applying the solution of the pressure-sensitive adhesive composition on the substrate or release material include spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure. Examples thereof include a coating method.

As a specific manufacturing method, as a manufacturing method of the pressure-sensitive adhesive sheet 1a with a substrate as shown in FIG. 1A, for example, a solution of the pressure-sensitive adhesive composition is directly applied to one surface of the substrate 11 and dried. Then, the method of forming the pressure-sensitive adhesive layer 12 and producing it can be mentioned.
Moreover, as a manufacturing method of the adhesive sheet 1b with a base material like FIG.1 (b), the solution of an adhesive composition is directly apply | coated on the peeling process surface of the peeling material 13, for example, it dries and it is an adhesive. Examples include a method in which the surface of the pressure-sensitive adhesive layer 12 exposed and the base material 11 are bonded together after the layer 12 is formed.
Furthermore, as a manufacturing method of the double-sided pressure-sensitive adhesive sheet 1c with a substrate as shown in FIG. 1C, for example, a solution of the pressure-sensitive adhesive composition is directly applied to each of both surfaces of the substrate and dried to be a pressure-sensitive adhesive layer. A method for producing 12, 12 ′ and two release materials are prepared, and a solution of the adhesive composition is directly applied onto the release-treated surface of each release material, followed by drying to provide an adhesive layer The method of bonding the adhesive layers 12a and 12b formed on the two release materials to both surfaces of the base material 11 and the like, etc., after the formation of the substrate, can be mentioned.
And as a manufacturing method of the adhesive sheet 1d without a base material like FIG.1 (d), for example, the solution of an adhesive composition is directly apply | coated to the peeling process surface of the one peeling material 13a, it dries by drying. Examples include a method in which another release material 13b is bonded to the surface of the pressure-sensitive adhesive layer 12 that is exposed after the layer 12 is formed.

In the following examples and comparative examples, methods for measuring various physical properties are as described below.
<Mass average molecular weight (Mw)>
Using a gel permeation chromatograph (manufactured by Tosoh Corporation, product name “HLC-8020”), the measurement was performed under the following conditions, and the measurement was performed in terms of standard polystyrene.
(Measurement condition)
Column: “TSK guard column HXL-H”, “TSK gel GMHXL” (two), and “TSK gel G2000HXL” (both manufactured by Tosoh Corporation) Column temperature: 40 ° C.
・ Developing solvent: Tetrahydrofuran ・ Flow rate: 1.0 mL / min

<Softening point>
It measured based on JISK2531.

<Arithmetic mean roughness Ra, maximum section height Rt>
Using a surface roughness measuring machine (product name “SV3000S4”, stylus type, manufactured by Mitutoyo Corporation), the measurement was performed according to JIS B0601: 1994. The measurement conditions are as follows.
Reference length = 2.5 mm, λc = 0.25 mm, λs = 0.008 mm, evaluation length = 10 mm, scanning speed = 1.0 mm / s, range = 800 μm.

<Flexibility of base material>
A sample for measurement was prepared by cutting a base material used in Examples and Comparative Examples into a rectangle of length 38 mm × width 25 mm.
About the measurement sample, using a bending resistance tester (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name “Gurley type flexibility tester”) under an environment of 23 ° C. and 50% RH (relative humidity), JIS In accordance with the Gurley method of L 1096 (1999) 8.20.1, the stiffness of the substrate in the flow direction (MD direction) during molding of the substrate and the direction perpendicular to the MD direction (TD direction) Each degree was measured.

<Tear strength of substrate>
A sample for measurement was prepared by cutting a base material used in Examples and Comparative Examples into a rectangle having a length of 75 mm and a width of 63 mm.
Four measurement samples are stacked, and a tear test is performed in accordance with JIS K 7128 using an Elmendorf Tear Tester (Toyo Seiki Seisakusho Co., Ltd.) in an environment of 23 ° C. and 50% RH (relative humidity). 4 times each in the MD direction and TD direction of the substrate. Then, the average value of each of the four values measured in the MD direction and the TD direction (tear strength for four base materials) is calculated, respectively, and the value of 1/4 of the average value is the tear strength of the base material. did.

<Thickness of adhesive layer>
The pressure-sensitive adhesive layer was measured in accordance with JIS K6783, Z1702, and Z1709 using a constant pressure thickness measuring device (manufactured by Teclock Co., Ltd., product name “PG-02J”).

Examples 1-43
Each component of the kind and compounding quantity (solid content ratio) shown in Table 1 was added, further diluted with toluene, and stirred to prepare respective solutions of the pressure-sensitive adhesive composition having a solid content concentration of 50% by mass.
Then, the prepared pressure-sensitive adhesive composition solution is applied to the release-treated surface of the release sheet (product of Lintec Corporation, product name “SP-PET751130”, thickness 75 μm) to form a coating film. Were dried at 100 ° C. for 1 minute to form pressure-sensitive adhesive layers having the thicknesses shown in Table 1, respectively.
Subsequently, the base material of the kind shown in Table 1 was laminated on the pressure-sensitive adhesive surface of the formed pressure-sensitive adhesive layer to obtain a pressure-sensitive adhesive sheet having the same configuration as that of the pressure-sensitive adhesive sheet 1b shown in FIG.

Comparative Examples 1-6
To 100 parts by mass (solid content ratio) of an acrylic resin (1) described later, a cross-linking agent described later is added in a blending amount (solid content ratio) shown in Table 1, diluted with ethyl acetate, and an adhesive composition. Each product solution was prepared.
Then, the prepared pressure-sensitive adhesive composition solution is applied to the release-treated surface of the release sheet (product of Lintec Corporation, product name “SP-PET751130”, thickness 75 μm) to form a coating film. Were dried at 100 ° C. for 1 minute to form pressure-sensitive adhesive layers having the thicknesses shown in Table 1, respectively.
Subsequently, the base material of the kind shown in Table 1 was laminated on the pressure-sensitive adhesive surface of the formed pressure-sensitive adhesive layer to obtain a pressure-sensitive adhesive sheet having the same configuration as that of the pressure-sensitive adhesive sheet 1b shown in FIG.

The details of the substrate used in Examples and Comparative Examples are as follows.
PET film: manufactured by Toray Industries, Inc., product name “Lumirror (R) T-60”, 50 μm thick polyethylene terephthalate (PET) film.
-Foamed PET film (1): A foamed PET film having a void-containing layer and a thickness of 50 µm. Bending softness: MD direction = 0.21 mN, TD direction = 0.22 mN, tear strength: MD direction = 270 mN, TD direction = 294 mN.
Foamed PET film (2): manufactured by Toyobo Co., Ltd., product name “Crisper K2411”. A foamed PET film having a void-containing layer and a thickness of 50 μm. Bending softness: MD direction = 0.25 mN, TD direction = 0.28 mN, tear strength: MD direction = 319 mN, TD direction = 294 mN.
-Foamed PP film: a product of "Yupo SGP80" manufactured by YUPO CORPORATION, and a foamed polypropylene (PP) film having a thickness of 80 µm and having a void-containing layer.

The detail of each component used for preparation of an adhesive composition is as follows.
<Adhesive resin>
Styrene resin (1): SIS resin (triblock body) / SI resin (diblock body) = 75/25 (mass%) mixed resin, styrene content = 15 mass%, Mw = 190,000.
Styrene resin (2): SIS resin (triblock body) / SI resin (diblock body) = 25/75 (mass%) mixed resin, styrene content = 15 mass%, Mw = 160,000.
Styrene resin (3): SIS resin (triblock body) / SI resin (diblock body) = 35/65 (mass%) mixed resin, styrene content = 25 mass%, Mw = 180,000.
Acrylic resin (1): Mw of 550,000 acryl, copolymerized with n-butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), acrylic acid (AAc), and 2-hydroxyethyl acrylate (HEA) Copolymer (constituent unit ratio: BA / EHA / AAc / HEA = 47.0 / 47.0 / 5.5 / 0.5 (mass%)).

<Tackifying resin>
Terpene resin (1): manufactured by Yasuhara Chemical Co., Ltd., product name “YS Resin PX1150N”, non-hydrogenated terpene resin, Mw = less than 10,000, softening point = 115 ° C.
Terpene resin (2): manufactured by Yasuhara Chemical Co., Ltd., product name “YS Polyester U115”, terpene phenol resin, Mw = less than 10,000, softening point = 115 ° C.
Terpene resin (3): manufactured by Yasuhara Chemical Co., Ltd., product name “YS Resin PX1000”, non-hydrogenated terpene resin, Mw = less than 10,000, softening point = 100 ° C.
Terpene resin (4): manufactured by Yasuhara Chemical Co., Ltd., product name “Clearon P105”, hydrogenated terpene resin, Mw = less than 10,000, softening point = 105 ° C.

Hydrocarbon resin (1): manufactured by Arakawa Chemical Industries, Ltd., product name “Alcon P-100”, alicyclic saturated hydrocarbon resin, Mw = less than 10,000, softening point = 100 ° C.
Hydrocarbon resin (2): manufactured by Arakawa Chemical Industries, Ltd., product name “Alcon P-90”, alicyclic saturated hydrocarbon resin, Mw = less than 10,000, softening point = 90 ° C.
Hydrocarbon resin (3): manufactured by Arakawa Chemical Industries, Ltd., product name “Alcon P-115”, alicyclic saturated hydrocarbon resin, Mw = less than 10,000, softening point = 115 ° C.
Hydrocarbon resin (4): manufactured by Arakawa Chemical Industries, Ltd., product name “Alcon P-125”, alicyclic saturated hydrocarbon resin, Mw = less than 10,000, softening point = 125 ° C.
Hydrocarbon resin (5): manufactured by Arakawa Chemical Industries, Ltd., product name “Arcon P-140”, alicyclic saturated hydrocarbon resin, Mw = less than 10,000, softening point = 140 ° C.
Hydrocarbon resin (6): manufactured by Nippon Zeon Co., Ltd., product name “Quinton LB406”, hydrocarbon resin, Mw = less than 10,000, softening point = 90 ° C.

Styrene resin (1): copolymer of styrene monomer and aliphatic monomer, Mw = less than 10,000, softening point = 95 ° C.

Rosin resin (1): manufactured by Arakawa Chemical Industries, Ltd., product name “Pine Crystal KE-100”, rosin ester resin, Mw = less than 10,000, softening point = 100 ° C.
Rosin resin (2): manufactured by AR BROWN, product name “Sylvalite RE85L”, non-hydrogenated rosin resin, Mw = less than 10,000, softening point = 85 ° C.
Rosin resin (3): manufactured by Arakawa Chemical Industries, Ltd., product name “Ester Gum HP”, hydrogenated rosin ester resin, Mw = less than 10,000, softening point = 80 ° C. or higher.

<Other additives>
-Liquid resin: Yasuhara Chemical Co., Ltd., product name "Dimaron", terpene resin.
-Liquid paraffin: Product name “MORESCO White P-350P” manufactured by MORESCO Co., Ltd.
Antioxidant: manufactured by ADEKA Corporation, product name “ADK STAB AO60”, hindered phenol antioxidant.
UV absorber: manufactured by ADEKA Corporation, product name “ADK STAB LA32”, benzotriazole UV absorber.
-Cross-linking agent: manufactured by Tosoh Corporation, product name “Coronate L”, isocyanate-based cross-linking agent.

Using the pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples, “adhesive strength against a rough surface of a polypropylene plate” was measured. The results are shown in Table 1.
<Adhesion to rough surface of polypropylene (PP) plate>
The pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were removed from the test piece release sheet cut into a rectangular shape with a length of 150 mm and a width of 25 mm, and the surface of the exposed pressure-sensitive adhesive layer had an arithmetic average roughness Ra of 2 μm and a maximum. The polypropylene plate having a rough surface with a cross-sectional height Rt of 17 μm was attached to the rough surface using a 2 kg roller and allowed to stand for 24 hours in an environment of 23 ° C. and 50% RH (relative humidity).
After standing, the adhesive force to the rough surface of the polypropylene (PP) plate was measured by a 180 ° peeling method at a pulling speed of 300 mm / min based on JIS Z0237: 2000.

  From Table 1, the pressure-sensitive adhesive sheets produced in Examples 1 to 43 were higher in the adhesive strength to the rough surface of the polypropylene plate than the pressure-sensitive adhesive sheets of Comparative Examples 1 to 6.

1a, 1b, 1c, 1d Adhesive sheet 11 Base material 12, 12a, 12b Adhesive layer 13, 13a, 13b Release material

Claims (2)

1 or more types of styrene resin (A) chosen from a styrene-isoprene diblock copolymer (SI) and a styrene-isoprene-styrene triblock copolymer (SIS), and a tackifying resin (B) are contained. A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition,
The pressure-sensitive adhesive layer has a thickness of 15 μm or more,
The adhesive sheet whose adhesive force with respect to the said rough surface of the polypropylene plate which has a rough surface whose arithmetic mean roughness Ra is 1.0-3.0 micrometers is 8.0 N / 25mm or more.   The pressure-sensitive adhesive sheet according to claim 1, wherein the tackifying resin (B) is at least one selected from rosin-based resins, terpene-based resins, styrene-based resins, and hydrocarbon-based resins.