Block copolymer composition and adhesive film

Abstract

To provide a block copolymer composition having practically sufficient adhesive strength and low blocking properties.SOLUTION: A block copolymer composition comprises 50 mass% or more and 90 mass% or less of a predetermined block copolymer: component (A), and 10 mass% or more and 50 mass% or less of a predetermined block copolymer: component (B), wherein the total content of vinyl aromatic monomer units in polymer blocks (Ar) composed mainly of vinyl aromatic monomer units contained in the components (A) and (B) is 5.0 mass% or more and 20.0 mass% or less relative to the entire block copolymer composition, the total content of vinyl aromatic monomer units contained in the components (A) and (B) is 20.0 mass% or more and 45.0 mass% or less relative to the entire block copolymer composition, and the average hydrogenation rate of conjugated diene monomer units contained in the components (A) and (B) is 90 mol% or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a block copolymer composition and an adhesive film.

Background Art

[0002] Block copolymers of vinyl aromatic compounds and conjugated diene compounds have elasticity similar to that of vulcanized natural rubber and synthetic rubbers at room temperature without vulcanization, and moreover, have processability similar to that of thermoplastic resins at high temperatures. Therefore, they have been widely used in fields such as footwear, plastic modification, asphalt modification, adhesives, etc., packaging materials for household products, home appliances and industrial parts, and toys. In addition, hydrogenated products of the block copolymer are widely used in automotive parts, medical instruments, etc. in addition to the above-mentioned application fields because they are excellent in weather resistance and heat resistance.

[0003] On the other hand, in recent years, smartphones, tablets, and thin TVs have become popular, and surface protection films are frequently used to prevent dirt and scratches during processing and transportation of optical films and optical resin plates that make up them. The surface protection film is used for protecting the surfaces of synthetic resin plates for building materials, stainless steel plates, aluminum plates, decorative plywood, steel plates, glass plates, furniture, utensils, home appliances, precision machinery, automobiles, and prism sheets used for optical applications from scratches, dust, and dirt. The surface protection film has a configuration in which an adhesive layer is formed on a predetermined support, and various proposals have been made conventionally regarding the adhesive that constitutes the adhesive layer.

[0004] As the adhesive used for the adhesive layer of such a surface protection film, acrylic adhesives and rubber-based adhesives mainly composed of rubbers such as natural rubber and polyisobutylene have been mainly used conventionally. As a method of applying these adhesives to a predetermined support, a method of applying an adhesive solution obtained by dissolving an adhesive in a solvent using a roll, a spray, or the like is used. These methods have the merit that an adhesive layer can be applied uniformly and thinly, but since a solvent is used, they have problems such as being unfavorable from the viewpoints of air pollution, fire, labor safety and hygiene during manufacturing, and economy. For these reasons, in recent years, as the surface protection film, a co-extruded film in which a base material layer made of a polyolefin resin and an adhesive layer containing a hydrogenated styrene-based elastomer or an olefin-based elastomer are integrated has been preferably used. For example, Patent Document 1 discloses a hydrogenated copolymer having a structure containing at least one polymer block A composed of vinyl aromatic monomer units or a hydrogenated polymer block C composed of conjugated diene monomer units and having a specific vinyl bond amount, and at least one hydrogenated random copolymer block B composed of vinyl aromatic monomer units and conjugated diene monomer units and having a specific vinyl bond amount.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the surface protection film as described above, while a practically sufficient adhesive force is required, there is a problem that when the adhesive force is high, blocking is likely to occur during product storage and it is difficult to handle.

[0007] Therefore, in the present invention, in view of the problems of the above-described conventional technologies, an object is to provide a block copolymer composition having a practically sufficient adhesive force and a low blocking property.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above-described problems of the prior art, the present inventors have found that, in a block copolymer composition having predetermined components (A) and (B), by specifying the physical properties of the components (A) and (B), the above-described problems can be solved, and the present invention has been completed. That is, the present invention is as follows.

[0009] [1] A block copolymer composition containing 50% by mass or more and 90% by mass or less of component (A) and 10% by mass or more and 50% by mass or less of component (B), wherein component (A) is a block copolymer containing a polymer block (Ar) mainly composed of at least two vinyl aromatic monomer units and a copolymer block (R) containing at least one vinyl aromatic monomer unit and a conjugated diene monomer unit, and having a weight average molecular weight of 80,000 or more and 200,000 or less, component (B) is a block copolymer containing a polymer block (Ar) mainly composed of at least two vinyl aromatic monomer units and a copolymer block (R) containing at least one vinyl aromatic monomer unit and a conjugated diene monomer unit, and having a weight average molecular weight of 120,000 or more and 900,000 or less, the total content of the vinyl aromatic monomer units in the polymer block (Ar) contained in component (A) and component (B) is 5.0% by mass or more and 20.0% by mass or less of the entire block copolymer composition, the total content of the vinyl aromatic monomer units contained in component (A) and component (B) is 20.0% by mass or more and 45.0% by mass or less of the entire block copolymer composition, and the average hydrogenation rate of the conjugated diene monomer units possessed by component (A) and component (B) is 90 mol% or more. Block copolymer composition. [2] the component (B) is component (B-1) having a weight-average molecular weight ratio to the weight-average molecular weight of the component (A) of 1.5 or more and less than 2.5, component (B-2) having a weight-average molecular weight ratio to the weight-average molecular weight of the component (A) of 2.5 or more and less than 3.5, component (B-3) having a weight-average molecular weight ratio to the weight-average molecular weight of the component (A) of 3.5 or more and less than 4.5, and contains at least one selected from the group consisting of the block copolymer composition according to the above [1]. [3] The area ratio of each of the component (B-1) and the component (B-2) in the GPC elution curve is larger than the area ratio of the component (B-3) in the GPC elution curve, the block copolymer composition according to the above [2]. [4] the component (A) is a block copolymer represented by (Ar-R-Ar) and / or (Ar-R-Ar)X, the component (B-1) is (Ar-R-Ar) 2 represented by X, the component (B-2) is (Ar-R-Ar) 3 represented by X, the component (B-3) is (Ar-R-Ar) 4 represented by X, wherein Ar represents a polymer block mainly composed of vinyl aromatic monomer units, R represents a copolymer block containing vinyl aromatic monomer units and conjugated diene monomer units, X represents a residue of a coupling agent or a residue of a polymerization initiator, the block copolymer composition according to the above [2] or [3]. [5] the component (A) is a block copolymer represented by (R-Ar-R-Ar) and / or (R-Ar-R-Ar)X, the component (B-1) is (R-Ar-R-Ar) 2represented by X, the component (B-2) is (R-Ar-R-Ar) 3 represented by X, the component (B-3) is (R-Ar-R-Ar) 4 represented by X, wherein Ar represents a polymer block mainly composed of vinyl aromatic monomer units, wherein R represents a copolymer block containing vinyl aromatic monomer units and conjugated diene monomer units, wherein X represents a residue of a coupling agent or a residue of a polymerization initiator, the block copolymer composition according to the above [2] or [3]. [6] the component (A) is a block copolymer represented by (D-Ar-R-Ar) and / or (D-Ar-R-Ar)X, the component (B-1) is (D-Ar-R-Ar) 2 represented by X, the component (B-2) is (D-Ar-R-Ar) 3 represented by X, the component (B-3) is (D-Ar-R-Ar) 4 represented by X, wherein Ar represents a polymer block mainly composed of vinyl aromatic monomer units, wherein R represents a copolymer block containing vinyl aromatic monomer units and conjugated diene monomer units, wherein D represents a polymer block mainly composed of conjugated diene monomers, wherein X represents a residue of a coupling agent or a residue of a polymerization initiator, the block copolymer composition according to the above [2] or [3]. [7] the average vinyl bond amount of the conjugated diene monomer units before hydrogenation in the component (A) and the component (B) is 40% or more, the block copolymer composition according to any one of the above [1] to [6]. [8] containing 70% by mass or more and 90% by mass or less of the component (A) The block copolymer composition according to any one of the above [1] to [7]. [9] An adhesive film in which an adhesive layer containing the block copolymer composition according to any one of the above [1] to [8] is disposed on at least one surface of a base material layer mainly composed of an olefin resin. [Advantages of the Invention]

[0010] According to the present invention, it is possible to provide a block copolymer composition having practically sufficient adhesive strength and low blocking property. [Brief Description of the Drawings]

[0011]

Figure 1

[0012] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. It should be noted that the following present embodiment is an exemplification for explaining the present invention, and is not intended to limit the present invention to the following contents. The present invention can be variously modified and implemented within the scope of its gist.

[0013] [Block Copolymer Composition] The block copolymer composition of the present embodiment is 50% by mass or more and 90% by mass or less of component (A), and contains 10% by mass or more and 50% by mass or less of component (B). Said component (A) is a polymer block (Ar) mainly composed of at least two vinyl aromatic monomer units, It contains a copolymer block (R) containing at least one vinyl aromatic monomer unit and a conjugated diene monomer unit, and is a block copolymer having a weight average molecular weight of 80,000 or more and 200,000 or less. The component (B) is a polymer block (Ar) mainly composed of at least two vinyl aromatic monomer units, and a copolymer block (R) containing at least one vinyl aromatic monomer unit and a conjugated diene monomer unit, and is a block copolymer having a weight average molecular weight of 120,000 or more and 900,000 or less. The total content of the vinyl aromatic monomer units in the polymer block (Ar) contained in the component (A) and the component (B) is 5.0% by mass or more and 20.0% by mass or less of the entire block copolymer composition. The total content of the vinyl aromatic monomer units contained in the component (A) and the component (B) is 20.0% by mass or more and 45.0% by mass or less of the entire block copolymer composition. The average hydrogenation rate of the conjugated diene monomer units possessed by the component (A) and the component (B) is 90 mol% or more.

[0014] The "vinyl aromatic monomer unit" refers to a structure resulting from polymerizing one vinyl aromatic compound, and the "conjugated diene monomer unit" refers to a structure resulting from polymerizing one conjugated diene compound.

[0015] The "polymer block (Ar) mainly composed of vinyl aromatic monomer units" means a polymer block containing 80% by mass or more of vinyl aromatic monomer units, preferably 85% by mass or more, more preferably 95% by mass or more. The "copolymer block (R) containing a vinyl aromatic monomer unit and a conjugated diene monomer unit" means a polymer block containing a vinyl aromatic monomer unit and a conjugated diene monomer unit and having a content of vinyl aromatic monomer units of less than 80% by mass. The polymer block (Ar) and the copolymer block (R) can be clearly distinguished from the above description. Hereinafter, each component will be described in more detail.

[0016] (Component (A)) The block copolymer composition of this embodiment contains component (A). Component (A) contains a polymer block (Ar) mainly composed of at least two vinyl aromatic monomer units and a copolymer block (R) containing at least one vinyl aromatic monomer unit and a conjugated diene monomer unit, and is a block copolymer having a weight average molecular weight of 80,000 or more and 200,000 or less. Component (A) has a polymer block (Ar) mainly composed of at least two vinyl aromatic monomer units. Thereby, compared with the case where the number of polymer blocks (Ar) is one or less, the adhesive force of the block copolymer composition of this embodiment tends to be stronger. The plurality of polymer blocks (Ar) contained in component (A) may be the same or different.

[0017] Also, as described above, the weight average molecular weight of component (A) is 80,000 or more and 200,000 or less. The lower the weight average molecular weight, the lower the melt viscosity, and the handling property during the extrusion molding of the block copolymer composition of this embodiment tends to improve. From this viewpoint, the weight average molecular weight of component (A) is 200,000 or less, preferably 180,000 or less, more preferably 170,000 or less, and even more preferably 160,000 or less. Also, the higher the weight average molecular weight, the higher the adhesive force of the block copolymer composition of this embodiment, and the blocking property tends to be better. From this viewpoint, the weight average molecular weight of component (A) is 80,000 or more, preferably 90,000 or more, more preferably 100,000 or more, and even more preferably 110,000 or more. The weight average molecular weight of component (A) can be measured by GPC (gel permeation chromatography), and specifically, it can be determined by the method described in the examples below.

[0018] (Component (B)) The block copolymer composition of this embodiment contains component (B). Component (B) is a block copolymer containing a polymer block (Ar) mainly composed of at least two vinyl aromatic monomer units and a copolymer block (R) containing at least one vinyl aromatic monomer unit and a conjugated diene monomer unit, and having a weight average molecular weight of 120,000 or more and 900,000 or less. Component (B) has a polymer block (Ar) mainly composed of at least two vinyl aromatic monomer units. Thereby, compared with the case where the number of polymer blocks (Ar) is one or less, the adhesive strength of the block copolymer composition of this embodiment tends to be stronger. The plurality of polymer blocks (Ar) contained in component (B) may be the same or different. Also, it may be the same as or different from the polymer block (Ar) contained in component (A).

[0019] Also, as described above, the weight average molecular weight of component (B) is 120,000 or more and 900,000 or less. The lower the weight average molecular weight, the lower the melt viscosity, and the handleability during the extrusion molding of the block copolymer composition of this embodiment tends to improve. From this viewpoint, the weight average molecular weight of component (B) is 900,000 or less, preferably 810,000 or less, more preferably 765,000 or less, and even more preferably 720,000 or less. Also, the higher the weight average molecular weight, the higher the adhesive strength of the block copolymer composition of this embodiment, and the blocking property tends to be better. From this viewpoint, the weight average molecular weight of component (B) is more preferably 135,000 or more, even more preferably 150,000 or more, and even more preferably 165,000 or more. The weight average molecular weight of component (B) can be measured by GPC (gel permeation chromatography), and specifically, it can be determined by the evaluation method described in the examples.

[0020] In the block copolymer composition of the present embodiment, it is preferable that the component (B) contains at least one of a component (B-1) having a weight average molecular weight ratio to the weight average molecular weight of the component (A) of 1.5 or more and less than 2.5, a component (B-2) having a weight average molecular weight ratio to the weight average molecular weight of the component (A) of 2.5 or more and less than 3.5, and a component (B-3) having a weight average molecular weight ratio to the weight average molecular weight of the component (A) of 3.5 or more and less than 4.5. Thereby, the balance between the adhesive strength and the blocking property of the block copolymer composition of the present embodiment tends to be improved. The component (B) may contain the component (B-1), the component (B-2), and the component (B-3) individually or in combination. When the component (B-2) is included, it is preferable to also include the component (B-1), and when the component (B-3) is included, it is preferable to also include the component (B-1) and the component (B-2). When a plurality of components are included, it is preferable that the area ratio of each of the component (B-1) and the component (B-2) in the GPC elution curve is larger than the area ratio of the component (B-3) in the GPC elution curve. Thereby, the balance between the adhesive strength and the blocking property of the block copolymer composition of the present embodiment tends to be further improved. The area ratios of the component (B-1), the component (B-2), and the component (B-3) in the component (B) in the GPC elution curve can be controlled, for example, by adjusting the addition amount, temperature, and time of the coupling agent in the coupling reaction.

[0021] Whether the component (B-1), the component (B-2), and the component (B-3) are included in the block copolymer composition of the present embodiment as the component (B) can be determined by the difference in the peak positions of the molecular weight distribution curves under the predetermined conditions shown below for GPC. That is, in the GPC curve, by confirming the peak (component (B-1)) at 1.5 times or more and less than 2.5 times the weight-average molecular weight of component (A), the peak (component (B-2)) at 2.5 times or more and less than 3.5 times the weight-average molecular weight of component (A), and the peak (component (B-3)) at 3.5 times or more and less than 4.5 times the weight-average molecular weight of component (A), components (B-1), (B-2), and (B-3) contained in the block copolymer composition of the present embodiment can be confirmed. The weight-average molecular weight of component (B) can be determined by the method described in the examples below.

[0022] Also, regarding the area ratio of components (B-1), (B-2), and (B-3) to the total area of component (B) in the GPC elution curve, after GPC measurement under the apparatus (ACQUITY APC system) and conditions described in the examples below, it is determined by vertical division up to the baseline at the inflection point between each peak of the GPC elution curve using the system software also described in the examples. The inflection points between each peak of components (B-1), (B-2), and (B-3) in the GPC elution curve are the lowest points (valley peaks) that are the lowest in the vertical direction between adjacent peaks. Also, when the lowest points are continuous, the midpoint is used. Using the aforementioned inflection points, vertical division is performed using a predetermined waveform separation software, and after division, the calculation of each weight-average molecular weight and the calculation of the area ratio are performed. In the GPC elution curve, a diagram showing the determination of the inflection points between each peak of components (B-2) and (B-3) and the vertical division at the inflection points is shown in FIG. 1. In FIG. 1, the horizontal axis is the elution time, and the vertical axis is the output value. In FIG. 1, the peak marked "199102" is component (B-1). In FIG. 1, the peak marked "275794" is component (B-2). In FIG. 1, the peak marked "352601" is component (B-3). In FIG. 1, the peak marked "93801" is component (A).

[0023] (Content of component (A) and component (B)) The block copolymer composition of this embodiment contains 50% by mass or more and 90% by mass or less of component (A) and 10% by mass or more and 50% by mass or less of component (B). From the viewpoint of improving the balance between the adhesiveness and the blocking property of the block copolymer composition of this embodiment, the content of component (A) is assumed to be 50% by mass or more, preferably 60% by mass or more, more preferably 65% by mass or more, and still more preferably 70% by mass or more. Also, from the same viewpoint, the content of component (A) is assumed to be 90% by mass or less, preferably 87% by mass or less, and more preferably 85% by mass or less. Similarly, from the viewpoint of improving the balance between the adhesiveness and the blocking property of the block copolymer composition of this embodiment, the content of component (B) is assumed to be 10% by mass or more, preferably 13% by mass or more, and more preferably 15% by mass or more. Also, from the same viewpoint, the content of component (B) is assumed to be 50% by mass or less, preferably 40% by mass or less, more preferably 35% by mass or less, and still more preferably 30% by mass or less.

[0024] In the block copolymer composition of this embodiment, the structures of the component (A), component (B), component (B-1), component (B-2), and component (B-3) are not particularly limited, but from the viewpoint of productivity, structures such as those in the following examples are preferred. Component (A) is a block copolymer represented by (Ar-R-Ar) and / or (Ar-R-Ar)X, and component (B-1) is (Ar-R-Ar) 2 represented by X, component (B-2) is (Ar-R-Ar) 3 represented by X, and component (B-3) is preferably a block copolymer represented by (Ar-R-Ar) 4 represented by X. The Ar represents a polymer block mainly composed of vinyl aromatic monomer units. The R represents a copolymer block containing vinyl aromatic monomer units and conjugated diene monomer units. The X represents a residue of a coupling agent or a residue of a polymerization initiator.

[0025] In addition, in the block copolymer composition of the present embodiment, another preferred embodiment is that component (A) is a block copolymer represented by (R-Ar-R-Ar) and / or (R-Ar-R-Ar)X, and component (B-1) is (R-Ar-R-Ar) 2 represented by X, component (B-2) is (R-Ar-R-Ar) 3 represented by X, and component (B-3) is (R-Ar-R-Ar) 4 represented by X and is a block copolymer. Ar represents a polymer block mainly composed of vinyl aromatic monomer units. R represents a copolymer block containing vinyl aromatic monomer units and conjugated diene monomer units. X represents a residue of a coupling agent or a residue of a polymerization initiator.

[0026] In addition, in the block copolymer composition of the present embodiment, another preferred embodiment is that component (A) is a block copolymer represented by (D-Ar-R-Ar) and / or (D-Ar-R-Ar)X, and component (B-1) is (D-Ar-R-Ar) 2 represented by X, component (B-2) is (D-Ar-R-Ar) 3 represented by X, and component (B-3) is (D-Ar-R-Ar) 4 represented by X and is a block copolymer. Ar represents a polymer block mainly composed of vinyl aromatic monomer units. R represents a copolymer block containing vinyl aromatic monomer units and conjugated diene monomer units. D represents a polymer block mainly composed of conjugated diene monomer units. X represents a residue of a coupling agent or a residue of a polymerization initiator. The "polymer block (D) mainly composed of conjugated diene monomer units" means a polymer block containing 80% by mass or more of conjugated diene monomer units and not containing vinyl aromatic monomer units.

[0027] The polymer blocks (Ar), (R), and (D) contained in component (A) and component (B) may be the same as or different from each other between component (A) and component (B).

[0028] (Content of vinyl aromatic monomer units in the polymer block (Ar) contained in component (A) and component (B) with respect to the entire block copolymer composition) The total content of vinyl aromatic monomer units in the polymer block (Ar) contained in component (A) and component (B) constituting the block copolymer composition of the present embodiment is 5.0% by mass or more and 20.0% by mass or less of the entire block copolymer composition. The higher the content of vinyl aromatic monomer units contained in the polymer block (Ar), the more likely the block copolymer composition of the present embodiment has good blocking properties. From this perspective, the total content of vinyl aromatic monomer units in the polymer block (Ar) contained in component (A) and component (B) is set to be 5.0% by mass or more of the entire block copolymer composition, preferably 8.0% by mass or more, more preferably 9.0% by mass or more, and even more preferably 10.0% by mass or more. Also, the lower the content of vinyl aromatic monomer units contained in the polymer block (Ar), the more likely the block copolymer composition of the present embodiment has improved adhesive strength. From this perspective, the total content of vinyl aromatic monomer units in the polymer block (Ar) contained in component (A) and component (B) is set to be 20.0% by mass or less of the entire block copolymer composition, preferably 18.0% by mass or less, more preferably 16.0% by mass or less, and even more preferably 15.0% by mass or less. The content of vinyl aromatic monomer units in the polymer block (Ar) contained in component (A) and component (B) may be the same as or different from each other between component (A) and component (B). The content of the vinyl aromatic monomer unit contained in the polymer block (Ar) included in the component (A) and the component (B) can be controlled within the above numerical range by adjusting the addition amount of the vinyl aromatic compound and the polymerization time during the polymerization process of the component (A) and the component (B) when forming the polymer block (Ar).

[0029] (Content of vinyl aromatic monomer unit) Moreover, in the block copolymer composition of the present embodiment, the total content of the vinyl aromatic monomer units contained in the component (A) and the component (B) is 20.0% by mass or more and 45.0% by mass or less of the entire block copolymer composition. When the content of the vinyl aromatic monomer units contained in the component (A) and the component (B) is within this range, the block copolymer composition of the present embodiment tends to have improved adhesive strength, preferably 22.0% by mass or more and 43.0% by mass or less, more preferably 24.0% by mass or more and 41.0% by mass or less, and even more preferably 26.0% by mass or more and 39.0% by mass or less. The content of the vinyl aromatic monomer units in the component (A) and the component (B) may be the same as or different from each other. The content of the vinyl aromatic monomer units contained in the component (A) and the component (B) can be controlled within the above numerical range by adjusting the addition amount of the vinyl aromatic compound and the polymerization time during the polymerization process of the component (A) and the component (B).

[0030] The total content of the vinyl aromatic monomer units in the polymer block (Ar) contained in the component (A) and the component (B), and the total content of the vinyl aromatic monomer units contained in the component (A) and the component (B) can be determined by the method described in the examples below.

[0031] (Average hydrogenation rate) In the block copolymer composition of the present embodiment, the average hydrogenation rate of the double bonds of the conjugated diene monomer units in the component (A) and the component (B), that is, the average value of the hydrogenation rates of the double bonds of the conjugated diene monomer units of the component (A) and the component (B) is 90 mol% or more. The higher the average hydrogenation rate of the double bond of the conjugated diene monomer unit, the more likely the heat resistance is to improve. From this perspective, the average hydrogenation rate of the double bond of the conjugated diene monomer unit in component (A) and component (B) is preferably 92 mol% or more, more preferably 94 mol% or more, and even more preferably 96 mol% or more. The average hydrogenation rate of the double bond of the conjugated diene monomer unit possessed by component (A) and component (B) can be measured by the method described in the examples below. Note that the hydrogenation rates of component (A) and component (B) may be the same or different from each other. The average hydrogenation rate of component (A) and component (B) can be controlled within the above numerical range by adjusting the hydrogen addition amount and hydrogenation time in the hydrogenation process of component (A) and component (B).

[0032] (Average vinyl bond amount of component (A) and component (B)) The average vinyl bond amount of the conjugated diene monomer unit before hydrogenation in component (A) and component (B) constituting the block copolymer composition of this embodiment is preferably 40% or more. When the average vinyl bond amount of the conjugated diene monomer unit before hydrogenation is high, the adhesive strength of the block copolymer composition of this embodiment tends to improve. From this perspective, the average vinyl bond amount of the conjugated diene monomer unit before hydrogenation in component (A) and component (B) is preferably 40% or more, more preferably 42% or more, even more preferably 45% or more, and even more preferably 48% or more. Also, from the perspective of blocking properties, the average vinyl bond amount of the conjugated diene monomer unit before hydrogenation is preferably 75% or less, more preferably 70% or less, and even more preferably 65% or less. Note that the vinyl bond amount of the conjugated diene monomer unit before hydrogenation may be the same or different between component (A) and component (B) as long as their average vinyl bond amounts are within the above range.

[0033] In addition, after hydrogenation, the ratio of the total mass of the conjugated diene monomer units incorporated in the bonding modes of the non-hydrogenated 1,2-bond, the hydrogenated 1,2-bond, the non-hydrogenated 3,4-bond, the hydrogenated 3,4-bond, the non-hydrogenated 1,4-bond, and the hydrogenated 1,4-bond to the total mass of the conjugated diene monomer units incorporated in the non-hydrogenated 1,2-bond, the hydrogenated 1,2-bond, the non-hydrogenated 3,4-bond, and the hydrogenated 3,4-bond is equal to the vinyl bond amount of the conjugated diene monomer units before hydrogenation. Therefore, the vinyl bond amount of the conjugated diene monomer units before hydrogenation can be measured by nuclear magnetic resonance spectrum analysis (NMR) using the block copolymer after hydrogenation, specifically, by the method described in the examples below.

[0034] As a method for adjusting the vinyl bond amount of the conjugated diene monomer units before hydrogenation in component (A) and component (B), for example, a method of using ethers, tertiary amines, etc. during the polymerization of component (A) and component (B) can be mentioned. Specifically, one or a mixture of two or more selected from ethylene glycol dimethyl ether, tetrahydrofuran, α-methoxytetrahydrofuran, N,N,N’,N’-tetramethylethylenediamine, 2,2-di(2-tetrahydrofuryl)propane, etc. is used. These are preferably added to the polymerization solvent at a stage before adding the conjugated diene monomer.

[0035] (Melt flow rate of block copolymer composition) From the viewpoint of ease of handling during film forming, the block copolymer composition of this embodiment preferably has a melt flow rate (MFR) of 5 g / 10 min or more and 20 g / 10 min or less under the conditions of 230 °C and 2.16 kg, more preferably 7 g / 10 min or more and 18 g / 10 min or less, even more preferably 8 g / 10 min or more and 16 g / 10 min or less, and even more preferably 9 g / 10 min or more and 15 g / 10 min or less.

[0036] (Vinyl aromatic compound, conjugated diene compound) The vinyl aromatic compound used for component (A) and component (B) in the block copolymer composition of this embodiment is not particularly limited. For example, alkyl styrenes such as styrene, α-methylstyrene, p-methylstyrene, and p-tert-butylstyrene; alkoxy styrenes such as p-methoxystyrene; vinyl naphthalene, etc. may be mentioned. Particularly, styrene is preferable. The vinyl aromatic compound may be used alone or in combination of two or more. In addition, the conjugated diene compound used for component (A) and component (B) is not particularly limited as long as it is a diolefin having a conjugated double bond. For example, 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, etc. may be mentioned. Particularly, 1,3-butadiene and isoprene are preferable. Furthermore, by using 1,3-butadiene, the block copolymer composition of this embodiment tends to be excellent in heat aging resistance and light resistance, so it is more preferable. The conjugated diene compound may be used alone or in combination of two or more.

[0037] [Production method of block copolymer composition] (Polymerization reaction and coupling reaction) As a production method of the block copolymer composition of this embodiment, for example, in an inert hydrocarbon solvent, using an organolithium compound as a polymerization initiator, copolymerizing a vinyl aromatic compound such as styrene and a conjugated diene compound such as butadiene to obtain a block copolymer, a polymerization step, a coupling step of reacting the block copolymer obtained in the polymerization step with a coupling agent to obtain component (A) and component (B) may be mentioned. In this case, for example, the coupled block copolymer becomes component (B), and the uncoupled remaining block copolymer becomes component (A). In addition, by controlling the addition amount of the coupling agent in this coupling reaction, the contents of component (A) and component (B) can be adjusted to the above-mentioned predetermined range. Alternatively, the block copolymer composition can also be obtained by polymerizing component (A) and component (B) separately and then mixing them later.

[0038] The weight average molecular weights of component (A) and component (B) can be controlled by adjusting the amount of polymerization initiator such as an organolithium compound. After the polymerization reaction is completed, a coupling reaction is carried out, water, alcohol, acid, etc. are added to deactivate the active species, and then, for example, after performing steam stripping or the like to separate the polymerization solvent, drying is performed to obtain the block copolymer composition of the present embodiment containing the above-mentioned component (A) and component (B). The polymerization method of the block copolymer of component (A) and component (B) is not particularly limited, and examples thereof include polymerization methods such as coordination polymerization, anionic polymerization, or cationic polymerization. Among these, from the viewpoint of ease of controlling the structure, anionic polymerization is preferred. As a method for producing a block copolymer by anionic polymerization, a known method can be used and is not particularly limited. For example, the methods described in Japanese Patent Publication No. 36-19286, Japanese Patent Publication No. 43-17979, Japanese Patent Publication No. 46-32415, Japanese Patent Publication No. 49-36975, Japanese Patent Publication No. 48-2423, Japanese Patent Publication No. 48-4106, Japanese Patent Publication No. 56-28925, Japanese Unexamined Patent Application Publication No. 59-166518, Japanese Unexamined Patent Application Publication No. 60-186577, etc. can be mentioned.

[0039] The inert hydrocarbon solvent used in the polymerization step of component (A) and component (B) constituting the block copolymer composition of the present embodiment is not limited to the following, and examples thereof include aliphatic hydrocarbons such as butane, pentane, hexane, isopentane, heptane, octane, isooctane; alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane; and hydrocarbon solvents such as aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene. These may be used alone or in combination of two or more.

[0040] In addition, as the organolithium compound used as a polymerization initiator in the polymerization step of component (A) and component (B) constituting the block copolymer composition of the present embodiment, known compounds can be used and are not limited to the following. For example, ethyllithium, propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, phenyllithium, propenyllithium, hexyllithium, etc. can be mentioned. In particular, n-butyllithium and sec-butyllithium are preferable. Only one kind of organolithium compound may be used, or a mixture of two or more kinds may be used.

[0041] Known ones can be used as the coupling agent for causing a coupling reaction using component (A) to obtain component (B). Examples of the bifunctional coupling agent include, but are not limited to, bifunctional halogenated silanes such as dichlorosilane, monomethyldichlorosilane, and dimethyldichlorosilane; bifunctional alkoxysilanes such as diphenyldimethoxysilane, diphenyldiethoxysilane, dimethyldimethoxysilane, and dimethyldiethoxysilane; bifunctional halogenated alkanes such as dichloroethane, dibromoethane, methylene chloride, and dibromomethane; bifunctional halogenated stannanes such as dichlorotin, monomethyldichlorotin, dimethyldichlorotin, monoethyldichlorotin, diethyldichlorotin, monobutyldichlorotin, and dibutyldichlorotin; dibromobenzene, benzoic acid, CO, 2-chloropropene, etc. Examples of the trifunctional coupling agent include, but are not limited to, trifunctional halogenated alkanes such as trichloroethane and trichloropropane; trifunctional halogenated silanes such as methyltrichlorosilane and ethyltrichlorosilane; trifunctional alkoxysilanes such as methyltrimethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane; etc. Examples of the tetrafunctional coupling agent include, but are not limited to, tetrafunctional halogenated alkanes such as carbon tetrachloride, carbon tetrabromide, and tetrachloroethane; tetrafunctional halogenated silanes such as tetrachlorosilane and tetrabromosilane; tetrafunctional alkoxysilanes such as tetramethoxysilane and tetraethoxysilane; and tetrafunctional tin compounds such as tetrachlorotin, tetrabromotin, and tetrabutyltin. Examples of the coupling agent having five or more functional groups include, but are not limited to, 1,1,1,2,2-pentachloroethane, perchloroethane, pentachlorobenzene, perchlorobenzene, octabromodiphenyl ether, and decabromodiphenyl ether. In addition, epoxidized soybean oil, epoxy group-containing compounds having two to six functional groups, carboxylic acid esters, and polyvinyl compounds such as divinylbenzene can also be used. The coupling agent may be used alone or in combination of two or more. Among these, tetramethoxysilane and tetraethoxysilane are particularly preferable.

[0042] The area ratios of component (B-1), component (B-2), and component (B-3) in the above-mentioned component (B) constituting the block copolymer composition of the present embodiment in the GPC elution curve can be controlled by adjusting the addition amount, temperature, and time of the coupling agent in the coupling reaction as described above. Specifically, when the coupling agent is an alkoxysilane compound, the time from when the reaction temperature reaches the maximum temperature until the coupling agent is added is 1 to 30 minutes, the reaction time of the coupling agent is 1 to 60 minutes, the reaction temperature is 55 to 100 °C, and the addition amount of the coupling agent is adjusted so that the molar ratio to the total number of moles of the polymerization initiator is 0.025 to 0.30. Also, when the coupling agent is other than an alkoxysilane compound, the time from when the reaction temperature reaches the maximum temperature until the coupling agent is added is 1 to 30 minutes, the reaction time of the coupling agent is 1 to 35 minutes, the reaction temperature is 50 to 95 °C, and the addition amount of the coupling agent is adjusted so that the molar ratio to the total number of moles of the polymerization initiator is 0.025 to 0.20.

[0043] (Hydrogenation reaction) When partially or entirely hydrogenating some or all of the unsaturated double bonds derived from the conjugated diene compound in component (A) and component (B), the hydrogenation method is not particularly limited and can be carried out using a known technique using a hydrogenation catalyst.

[0044] The hydrogenation catalyst is not particularly limited and known catalysts can be used. For example, supported heterogeneous hydrogenation catalysts in which metals such as Ni, Pt, Pd, Ru, etc. are supported on carbon, silica, alumina, diatomaceous earth, etc.; so-called Ziegler-type hydrogenation catalysts using transition metal salts such as organic acid salts or acetylacetone salts of Ni, Co, Fe, Cr, etc. and reducing agents such as organoaluminum; homogeneous hydrogenation catalysts such as so-called organometallic complexes such as organometallic compounds of Ti, Ru, Rh, Zr, etc. are used. Specifically, the hydrogenation catalysts described in Japanese Patent Publication No. Sho 42-8704, Sho 43-6636, Sho 63-4841, Hei 1-37970, Hei 1-53851, and Hei 2-9041 can be used. Among these, preferred hydrogenation catalysts include titanocene compounds, reducing organometallic compounds, or mixtures thereof. Examples of titanocene compounds include, but are not limited to, the compounds described in Japanese Patent Laid-Open No. Hei 8-109219. Specifically, compounds having at least one ligand having a (substituted) cyclopentadienyl skeleton, indenyl skeleton, or fluorenyl skeleton such as biscyclopentadienyltitanium dichloride and monopenta-methylcyclopentadienyltitanium trichloride can be mentioned. Examples of reducing organometallic compounds include, but are not limited to, organoalkali metal compounds such as organolithium, organomagnesium compounds, organoaluminum compounds, organoboron compounds, or organozinc compounds.

[0045] The hydrogenation reaction temperature is preferably 0 to 200°C, more preferably 30 to 150°C. Also, the pressure of hydrogen used in the hydrogenation reaction is preferably 0.1 to 15 MPa, more preferably 0.2 to 10 MPa, and even more preferably 0.3 to 5 MPa. Further, the hydrogenation reaction time is preferably 3 minutes to 10 hours, more preferably 10 minutes to 5 hours.

[0046] The hydrogenation reaction may be any of a batch process, a continuous process, or a combination thereof.

[0047] A block copolymer composition can be obtained by removing catalyst residues, if necessary, from a solution of the block copolymer obtained through a hydrogenation reaction and separating the solution. Examples of the method for separating the solvent include, but are not limited to, adding a polar solvent such as acetone or alcohol, which is a poor solvent for the hydrogenated block copolymer, to the reaction solution after hydrogenation to precipitate and recover the polymer; introducing the reaction solution after hydrogenation into hot water under stirring and removing and recovering the solvent by steam stripping; heating the reaction solution after hydrogenation to distill off the solvent; and the like.

[0048] (Other steps) In the method for producing the block copolymer composition of the present embodiment, a step of deashing metals derived from a polymerization initiator or the like can be employed, if necessary. Further, in the method for producing the block copolymer composition of the present embodiment, a step of adding an antioxidant, a neutralizing agent, a surfactant, etc. can be employed, if necessary. Examples of the antioxidant include, but are not limited to, hindered phenol-based compounds, phosphorus-based compounds, sulfur-based compounds, etc. similar to those described later. Examples of the neutralizing agent include, but are not limited to, various metal stearates, hydrotalcite, benzoic acid, etc. Examples of the surfactant include, but are not limited to, anionic surfactants, nonionic surfactants, cationic surfactants, etc. Examples of the anionic surfactant include, but are not limited to, fatty acid salts, alkyl sulfate esters, alkyl aryl sulfonates, etc. Examples of the nonionic surfactant include, but are not limited to, polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, etc. Examples of the cationic surfactant include, but are not limited to, alkylamine salts, quaternary ammonium salts, etc.

[0049] The block copolymer composition of the present embodiment that can be produced as described above may include a so-called modified block copolymer in which a polar group-containing functional group containing an atom selected from nitrogen, oxygen, silicon, phosphorus, sulfur, and tin is bonded to the block copolymer, or a modified block copolymer obtained by modifying the block copolymer component with a modifier such as maleic anhydride. Such a modified block copolymer can be obtained by performing a known modification reaction on components (A) and (B). Examples of the method for imparting these functional groups include, but are not limited to, a method of adding a functional group to the block copolymer by using a compound containing a functional group as a polymerization initiator, a monomer, a coupling agent, or a polymerization terminator, respectively.

[0050] As the polymerization initiator containing a functional group, a polymerization initiator containing an N group is preferable. Examples include, but are not limited to, dioctylaminolithium, di-2-ethylhexylaminolithium, ethylbenzylaminolithium, (3-(dibutylamino)-propyl)lithium, piperidinolithium, and the like.

[0051] In addition, examples of the monomer containing a functional group include compounds containing a hydroxyl group, an acid anhydride group, an epoxy group, an amino group, an amide group, a silanol group, and an alkoxysilane group in the monomers used for the aforementioned polymerization. Among these, monomers containing a functional group having a nitrogen atom are preferable. Although not limited to the following, for example, N,N-dimethylvinylbenzylamine, N,N-diethylvinylbenzylamine, N,N-dipropylvinylbenzylamine, N,N-dibutylvinylbenzylamine, N,N-diphenylvinylbenzylamine, 2-dimethylaminoethylstyrene, 2-diethylaminoethylstyrene, 2-bis(trimethylsilyl)aminoethylstyrene, 1-(4-N,N-dimethylaminophenyl)-1-phenylethylene, N,N-dimethyl-2-(4-vinylbenzyloxy)ethylamine, 4-(2-pyrrolidinoethyl)styrene, 4-(2-piperidinoethyl)styrene, 4-(2-hexamethyleneiminoethyl)styrene, 4-(2-morpholinoethyl)styrene, 4-(2-thiazinoethyl)styrene, 4-(2-N-methylpiperazinoethyl)styrene, 1-((4-vinylphenoxy)methyl)pyrrolidine, 1-(4-vinylbenzyloxymethyl)pyrrolidine, and the like can be mentioned.

[0052] Furthermore, examples of the coupling agent and polymerization terminator containing a functional group include compounds containing a hydroxyl group, acid anhydride group, epoxy group, amino group, amide group, silanol group, alkoxysilane group, etc. among the aforementioned coupling agents. Among these, coupling agents containing a functional group having a nitrogen atom or an oxygen atom are preferred. Although not limited to the following, for example, tetraglycidyl metaxylenediamine, tetraglycidyl-1,3-bis(aminomethyl)cyclohexane, tetraglycidyl-p-phenylenediamine, tetraglycidyl diaminodiphenylmethane, diglycidyl aniline, γ-caprolactone, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriphenoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyldiethylethoxysilane, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, N-methylpyrrolidone, etc. can be mentioned.

[0053] (Isolation step) After producing the block copolymer of components (A) and (B) constituting the block copolymer composition of the present embodiment as described above, isolation, that is, finishing of the block copolymer is carried out by the method described later. When the polymerization step of components (A) and (B) is carried out in an inert hydrocarbon solvent, the inert hydrocarbon solvent is removed to isolate the block copolymer. As a specific method for removing the solvent, steam stripping can be mentioned. By steam stripping, a hydrous cake can be obtained, and the obtained hydrous cake can be dried to obtain the block copolymer. In steam stripping, it is preferable to use a surfactant as the flocculant. Such surfactants are not particularly limited, and examples include the same anionic surfactants, cationic surfactants, and nonionic surfactants as described above. These surfactants can generally be added to the water in the stripping zone at 0.1 to 3000 ppm. In addition to the surfactant, water-soluble salts of metals such as Li, Na, Mg, Ca, Al, and Zn can also be used as dispersion aids for the flocs.

[0054] The concentration of the floc-like block copolymer dispersed in water obtained through the polymerization step of the block copolymer and the steam stripping is generally 0.1 to 20% by mass (ratio to the water in the stripping zone). Within this range, flocs with good particle sizes can be obtained without causing operational problems. It is preferable to adjust the water content of the flocs of this block copolymer to 1 to 30% by mass by dehydration and then perform drying until the water content becomes 1% by mass or less. In the dehydration step of the flocs, dehydration with a compression water squeezer such as a roll, Banbury dehydrator, or screw extruder type squeezing dehydrator, or dehydration and drying can be performed simultaneously with a conveyor or a box-type hot air dryer.

[0055] [Adhesive film] The adhesive film of this embodiment is formed by disposing an adhesive layer containing the block copolymer composition of this embodiment on at least one side of a base material layer mainly composed of an olefin resin. According to the adhesive film of this embodiment, while exhibiting practically sufficient adhesive force, the film unwinding property when the adhesive film is formed into a roll is good.

[0056] (Adhesive layer) The adhesive layer containing the block copolymer composition may consist only of the block copolymer composition of this embodiment or may contain other components. Examples of the other components include polymers different from component (A) and component (B) that constitute the block copolymer composition of the present embodiment, tackifiers, softeners, antioxidants, waxes, stabilizers such as light stabilizers, and other additives.

[0057] <Tackifier> When the pressure-sensitive adhesive layer containing the block copolymer composition contains a tackifier, the tackifier can be selected in various ways depending on the required performance. Examples of the tackifier include, but are not limited to, rosin-based compounds such as natural rosin, modified rosin, glycerol ester of natural rosin, glycerol ester of modified rosin, pentaerythritol ester of natural rosin, pentaerythritol ester of modified rosin, hydrogenated rosin, and pentaerythritol ester of hydrogenated rosin; terpene-based compounds such as copolymers of natural terpenes, three-dimensional polymers of natural terpenes, aromatic-modified terpene fats, hydrogenated derivatives of aromatic-modified terpene resins, terpene phenol resins, hydrogenated derivatives of terpene phenol resins, terpene resins (monoterpenes, diterpenes, triterpenes, polypentenes, etc.), hydrogenated terpene resins, and hydrogenated derivatives of hydrogenated terpene resins; hydrocarbon-based compounds such as aliphatic petroleum hydrocarbon resins (C5 resins), hydrogenated derivatives of aliphatic petroleum hydrocarbon resins, aromatic petroleum hydrocarbon resins (C9 resins), hydrogenated derivatives of aromatic petroleum hydrocarbon resins, dicyclopentadiene-based resins, hydrogenated derivatives of dicyclopentadiene-based resins, C5 / C9 copolymer resins, hydrogenated derivatives of C5 / C9 copolymer resins, cycloaliphatic petroleum hydrocarbon resins, and hydrogenated derivatives of cycloaliphatic petroleum hydrocarbon resins, and aromatic group-containing resins. These tackifiers may be used alone or in combination of two or more. The C5 / C9 copolymer resin is a copolymer petroleum resin polymerized from a mixture of a C5 fraction and a C9 fraction as raw materials.

[0058] As the tackifier, in addition to solid ones, liquid-type tackifiers with a colorless to light yellow color tone, substantially no odor, and good thermal stability can also be used. Hereinafter, preferred tackifiers according to the use and performance will be described in more detail.

[0059] [Tackifier of hydrogenated derivative] From the viewpoints of suppressing coloring and having low odor, the tackifier is preferably a hydrogenated derivative. Examples of the hydrogenated derivative include, but are not limited to, hydrogenated derivatives of aromatic-modified terpene resins, hydrogenated derivatives of terpene phenol resins, hydrogenated derivatives of hydrogenated terpene resins, hydrogenated derivatives of aliphatic petroleum hydrocarbon resins (C5 resins), hydrogenated derivatives of aromatic petroleum hydrocarbon resins (C9 resins), hydrogenated derivatives of dicyclopentadiene resins, hydrogenated derivatives of C5 / C9 copolymer resins, and hydrogenated derivatives of cycloaliphatic petroleum hydrocarbon resins. Among these, hydrogenated derivatives of aromatic petroleum hydrocarbon resins (C9 resins), hydrogenated derivatives of dicyclopentadiene resins, hydrogenated derivatives of hydrogenated terpene resins, etc. are particularly preferred. Examples of commercially available products of such hydrogenated derivatives include, but are not limited to, Alcon P and M series (trade names) manufactured by Arakawa Chemical Industries, Ltd., Imerub S and P series manufactured by Idemitsu Kosan Co., Ltd., Escorez 5000 series (trade names) manufactured by ExxonMobil Chemical Company, Clearon P series manufactured by Yasuhara Chemical Co., Ltd., etc.

[0060] [Tackifiers other than hydrogenated derivatives] Examples of tackifiers other than hydrogenated derivatives include, but are not limited to, natural rosin, modified rosin, glycerol esters of natural rosin, glycerol esters of modified rosin, pentaerythritol esters of natural rosin, pentaerythritol esters of modified rosin, hydrogenated rosin, pentaerythritol esters of hydrogenated rosin; copolymers of natural terpenes, three-dimensional polymers of natural terpenes, aromatic modified terpene resins, terpene phenol resins, terpene resins, hydrogenated terpene resins; aliphatic petroleum hydrocarbon resins (C5 resins), aromatic petroleum hydrocarbon resins (C9 resins), dicyclopentadiene resins, C5 / C9 copolymer resins, cycloaliphatic petroleum hydrocarbon resins. Among these, aliphatic petroleum hydrocarbon resins (C5 resins), aromatic petroleum hydrocarbon resins (C9 resins), C5 / C9 copolymer resins, cycloaliphatic petroleum hydrocarbon resins, terpene resins, natural and modified rosin esters, and mixtures thereof are preferred. Examples of commercially available products include, as aliphatic petroleum hydrocarbon resins (C5 resins), for example, Quintone 100 series (trade name) manufactured by Nippon Zeon Co., Ltd., Escorez 1000 series manufactured by ExxonMobil Chemical Co., Ltd., and WINGTACK series (trade name) manufactured by Kraton Polymers; as aromatic petroleum hydrocarbon resins (C9 resins) and C5 / C9 copolymer resins, for example, PICCOTAC series (trade name) manufactured by Eastman Chemical Co., Ltd., Escorez 2000 series (trade name) manufactured by ExxonMobil Chemical Co., Ltd., and FTR series (trade name) manufactured by Mitsui Chemicals, Inc.; as terpene resins, natural and modified rosin esters, for example, SYLVALITE series, SYLVARES series (trade name) manufactured by Arizona Chemical Co., Inc., PICCOLYTE series (trade name) manufactured by Pinova AB, etc.

[0061] [Aliphatic tackifier] Examples of aliphatic tackifiers include, but are not limited to, aliphatic petroleum hydrocarbon resins (C5 resins), hydrogenated derivatives of aliphatic petroleum hydrocarbon resins (C5 resins), C5 / C9 copolymer resins, and hydrogenated derivatives of C5 / C9 copolymer resins. The aliphatic tackifier refers to a tackifier in which the content of aliphatic hydrocarbon groups is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, even more preferably 88% by mass or more, and even more preferably 95% by mass or more. Aliphatic tackifiers can be produced by homopolymerizing or copolymerizing monomers having an aliphatic group and a polymerizable unsaturated group. Examples of monomers having an aliphatic group and a polymerizable unsaturated group include, but are not limited to, natural and synthetic terpenes containing a C5 or C6 cyclopentyl or cyclohexyl group. Other monomers that can be used in copolymerization include, but are not limited to, 1,3-butadiene, cis-1,3-pentadiene, trans-1,3-pentadiene, 2-methyl-1,3-butadiene, 2-methyl-2-butene, cyclopentadiene, dicyclopentadiene, terpenes, terpene-phenol resins, and the like.

[0062] [Aromatic tackifiers] Examples of aromatic tackifiers include, but are not limited to, aromatic petroleum hydrocarbon resins (C9 resins) and C5 / C9 copolymer resins. The aromatic tackifier refers to a tackifier in which the content of aromatic hydrocarbon groups is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, even more preferably 88% by mass or more, and even more preferably 95% by mass or more. The aromatic tackifier can be produced by homopolymerizing or copolymerizing a monomer having an aromatic group and a polymerizable unsaturated group respectively. Examples of the monomer having an aromatic group and a polymerizable unsaturated group include, but are not limited to, styrene, α-methylstyrene, vinyltoluene, methoxystyrene, tert-butylstyrene, chlorostyrene, indene monomer (including methylindene), etc. Further, examples of other monomers that can be used in copolymerization include, but are not limited to, 1,3-butadiene, cis-1,3-pentadiene, trans-1,3-pentadiene, 2-methyl-1,3-butadiene, 2-methyl-2-butene, cyclopentadiene, dicyclopentadiene, terpene, terpene-phenol resin, etc.

[0063] [Tackifier having affinity with the glass phase of the block copolymer (for example, the polymer block (Ar))] In the pressure-sensitive adhesive film of the present embodiment, from the viewpoint of obtaining high adhesive strength and suppressing the change in adhesive strength over time, it is also a preferred embodiment that the pressure-sensitive adhesive layer contains a tackifier having affinity with the block of the glass phase of the block copolymer (for example, a polymer block (Ar) mainly composed of vinyl aromatic monomer units). Here, the block copolymer means including the above-described component (A) and component (B). Examples of the tackifier having affinity with the block of the glass phase of the block copolymer include, but are not limited to, resins having an aromatic ring between molecules. Examples of such resins include, but are not limited to, aromatic group-containing resins such as homopolymers or copolymers containing vinyltoluene, styrene, α-methylstyrene, coumarone, or indene as a structural unit. Further, among these, Kristalex and Plastolyn (trade name, manufactured by Eastman Chemical Company) having α-methylstyrene are preferred. The compounding amount of the tackifier having an affinity for the block of the glass phase of the block copolymer is preferably 3 to 30 parts by mass, more preferably 5 to 20 parts by mass, and still more preferably 6 to 12 parts by mass with respect to 100 parts by mass of the block copolymer composition of the present embodiment. From the viewpoints of high initial adhesiveness and high wettability, it is preferable to use a petroleum resin having an aroma content of 3 to 12% by mass as the tackifier. Examples of such petroleum resins include, but are not limited to, aliphatic petroleum hydrocarbon resins (C5-based resins), hydrogenated derivatives of aliphatic petroleum hydrocarbon resins (C5-based resins), aromatic petroleum hydrocarbon resins (C9-based resins), hydrogenated derivatives of aromatic petroleum hydrocarbon resins (C9-based resins), dicyclopentadiene-based resins, hydrogenated derivatives of dicyclopentadiene-based resins, C5 / C9 copolymer-based resins, hydrogenated derivatives of C5 / C9 copolymer-based resins, cycloaliphatic petroleum hydrocarbon resins, and hydrogenated derivatives of cycloaliphatic petroleum hydrocarbon resins. The aroma content of the petroleum resin is preferably 3 to 12% by mass, more preferably 4 to 10% by mass. Among these, hydrogenated petroleum resins are particularly preferable.

[0064] In the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive film of the present embodiment, the content of the tackifier is preferably 1 to 200 parts by mass with respect to 100 parts by mass of the block copolymer composition of the present embodiment, and can be selected in a wide variety according to the use and required performance of the obtained pressure-sensitive adhesive layer.

[0065] <Softening agent> The "softening agent" refers to a substance having the function of lowering the hardness and viscosity of the pressure-sensitive adhesive layer. Examples of the softening agent include, but are not limited to, oils; plasticizers; synthetic liquid oligomers; and mixtures thereof. Hereinafter, preferable softening agents according to use and performance will be described more specifically.

[0066] From the viewpoints of improving the adhesiveness and lowering the hardness of the adhesive layer, oils can be used. Examples of the oils include, but are not limited to, known paraffinic process oils, naphthenic process oils, aromatic process oils, and mixed oils thereof.

[0067] In addition, plasticizers can be used as softening agents. Examples of the (liquid) plasticizers include, but are not limited to, liquid paraffin; fatty acid esters composed of higher fatty acids having 12 to 16 carbon atoms such as isopropyl myristate, ethyl laurate, and isopropyl palmitate and lower monohydric alcohols having 1 to 4 carbon atoms; fatty acids having 8 to 10 carbon atoms; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, and polypropylene glycol; oils and fats such as olive oil, castor oil, squalene, and lanolin; organic solvents such as ethyl acetate, ethyl alcohol, dimethyldecyl sulfoxide, decylmethyl sulfoxide, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, dimethyllaurylamide, dodecyl pyrrolidone, isosorbide, oleyl alcohol, and lauric acid; liquid surfactants; ethoxylated stearyl alcohol, glycerin ester, isotridecyl myristate, N-methylpyrrolidone, ethyl oleate, oleic acid, diisopropyl adipate, octyl palmitate, 1,3-propanediol, and glycerin. Compounds that are liquid at normal temperature are used from among these. The plasticizer may be used alone or in combination of two or more.

[0068] When it is desired to make the adhesive layer softer, synthetic liquid oligomers can be used from the viewpoint of improving bleedability. Examples of the synthetic liquid oligomers include, but are not limited to, styrene oligomers, butadiene oligomers, isoprene oligomers, and butene oligomers.

[0069] Examples of commercially available softening agents include, but are not limited to, Diana Freshia S32 (trade name), Diana Process Oil PW-90 (trade name), Process Oil NS100 (trade name), Process Oil NS90S (trade name) manufactured by Idemitsu Kosan Co., Ltd.; White Oil Broom350 (trade name), DN Oil KP-68 (trade name) manufactured by Kukdong Oil&Chem Co., Ltd.; Enerper M1930 (trade name) manufactured by BP Chemicals; Kaydol (trade name) manufactured by Crompton; Primol 352 (trade name) manufactured by Esso; KN4010 (trade name) manufactured by PetroChina Company, etc. Also, the content of the softening agent can be selected in a wide variety according to the required performance.

[0070] <Antioxidant> Examples of antioxidants include, but are not limited to, hindered phenol antioxidants such as 2,6-di-t-butyl-4-methylphenol, n-octadecyl 3-(4'-hydroxy-3',5'-di-t-butylphenyl) propionate, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 2,4-bis[(octylthio)methyl]-o-cresol, 2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 2,4-di-t-amyl-6-[1-(3,5-di-t-amyl-2-hydroxyphenyl)ethyl]phenyl acrylate, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)] acrylate; sulfur antioxidants such as dilauryl thiodipropionate, lauryl stearyl thiodipropionate, pentaerythritol tetrakis(β-laurylthiopropionate); phosphorus antioxidants such as tris(nonylphenyl) phosphite, tris(2,4-di-t-butylphenyl) phosphite, etc. Examples of commercially available antioxidants include, for example, Sumilizer GM (trade name), Sumilizer TPD (trade name), and Sumilizer TPS (trade name) manufactured by Sumitomo Chemical Co., Ltd., Irganox 1010 (trade name), Irganox HP2225FF (trade name), Irgafos 168 (trade name), and Irganox 1520 (trade name) manufactured by Ciba Specialty Chemicals, and JF77 (trade name) manufactured by Johoku Chemical Co., Ltd. These antioxidants may be used alone or in combination of two or more. The content of the antioxidant is arbitrary, but is preferably 5 parts by mass or less with respect to 100 parts by mass of the block copolymer composition.

[0071] <Polymers other than component (A) and component (B)> The block copolymer composition of this embodiment may contain a polymer other than component (A) and component (B). Examples of the polymer other than component (A) and component (B) include, but are not limited to, polyolefin copolymers, vinyl aromatic copolymers, and other rubbers. In this specification, "other than component (A) and component (B)" means not corresponding to either component (A) or component (B).

[0072] Examples of the polyolefin copolymer include, but are not limited to, atactic polypropylene, ethylene-ethyl acrylate copolymer, and α-olefin polymers.

[0073] Examples of the vinyl aromatic copolymer include, but are not limited to, styrene-ethylene block copolymer, styrene-butadiene block copolymer, styrene-propylene block copolymer, styrene-isoprene block copolymer, styrene-butadiene-isoprene block copolymer, styrene-butadiene / isoprene block copolymer, hydrogenated styrene-butadiene block copolymer, hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-butadiene-isoprene block copolymer, hydrogenated styrene-butadiene / isoprene block copolymer, etc., and polymers other than component (A) and component (B). The vinyl aromatic copolymer may be a vinyl aromatic thermoplastic resin or a vinyl aromatic elastomer.

[0074] Examples of other rubbers include, but are not limited to, natural rubber; synthetic rubbers such as isoprene-isobutylene rubber, polyisoprene rubber, polybutadiene rubber, styrene-butadiene rubber, styrene-isoprene rubber, propylene-butylene rubber, ethylene-propylene rubber, chloroprene rubber, acrylic rubber, isoprene-isobutylene rubber, polypentenamer rubber.

[0075] Hereinafter, polymers other than the preferred components (A) and (B) according to the use and performance will be described more specifically.

[0076] [Hydrogenated vinyl aromatic copolymer] When it is necessary to reduce the glue residue when peeling off the adhesive layer, suppress the change in adhesive strength over time, improve thermal stability, light resistance, etc., it is preferable to use a hydrogenated vinyl aromatic copolymer as the polymer other than the components (A) and (B). Examples of the hydrogenated vinyl aromatic copolymer include, but are not limited to, hydrogenated styrene-butadiene block copolymers having a structure such as S-EB-S (S: polystyrene block, EB: ethylene / butylene copolymer block); hydrogenated styrene-isoprene block copolymers having a structure such as S-EP-S (S: polystyrene block, EP: ethylene / propylene copolymer block), or hydrogenated styrene-butadiene-isoprene block copolymers having a structure such as S-E-EP-S (S: polystyrene block, E: ethylene block, EP: ethylene / propylene copolymer block). The styrene content of the hydrogenated vinyl aromatic copolymer is preferably 10% by mass to 45% by mass with respect to 100% by mass of the hydrogenated vinyl aromatic copolymer. In addition, the hydrogenation rate of the unsaturated groups in the conjugated diene in the hydrogenated vinyl aromatic copolymer is preferably 30 mol% or more, more preferably 50 mol% or more, still more preferably 70 mol% or more, and even more preferably 85 mol% or more.

[0077] [Isoprene block copolymer] When high adhesiveness or suppression of gelation is required for the adhesive layer, it is preferable to use an isoprene block copolymer having isoprene monomer units. Examples of the isoprene block copolymer include, but are not limited to, (S-I) n , (S-I) n -S, (S-I) n Y (S: polystyrene block, I: polyisoprene block, Y: residue of a polyfunctional coupling agent or residue of a polymerization initiator, n is an integer of 1 or more, preferably an integer of 1 to 5) and other styrene-isoprene block copolymers having such a structure; (S-I-B) n , (SI-B) n , (S-I-B) nY (where S is a polystyrene block, I is a polyisoprene block, B is a polybutadiene block, Y is a residue of a polyfunctional coupling agent or a residue of a polymerization initiator, n is an integer of 1 or more, preferably an integer of 1 to 5), or (S-I / B) n , (S-I / B) n -S, (S-I / B) n Examples thereof include styrene-butadiene-isoprene block copolymers having a structure such as Y (where S is a polystyrene block, I / B is an isoprene / butadiene copolymer block, Y is a residue of a coupling agent or a residue of a polymerization initiator, n is an integer of 1 or more, preferably an integer of 1 to 5). More preferably, these have a radial structure.

[0078] [Polyolefin copolymer] As the adhesive layer, when high-temperature storage stability is required, it is preferable to use a polyolefin copolymer. Examples of the polyolefin copolymer include, but are not limited to, copolymers of α-olefins and olefins, or propylene homopolymers. The melting points of these polymers (condition: DSC measurement, 5°C / min) are preferably 110°C or lower, more preferably 100°C or lower, and still more preferably 60°C to 90°C. These polymers may be thermoplastic resins or elastomers. The molecular weight distribution of these polymers is preferably 1 to 4, more preferably 1 to 3. From the viewpoint of processability, it is more preferable to use two or more copolymers using α-olefins or propylene homopolymers in combination. Specifically, it is preferable to use in combination a polymer having a weight average molecular weight of 30,000 to 60,000 and a polymer having a weight average molecular weight of 60,000 to 90,000, and it is more preferable to use in combination a polymer having a weight average molecular weight of 35,000 to 55,000 and a polymer having a weight average molecular weight of 60,000 to 80,000. Also, the liquid component (such as oil) in the adhesive layer using these is preferably 20% by mass or more, more preferably 25% by mass or more.

[0079] [Conjugated diene rubber] In addition, according to the required performance of the adhesive layer, conjugated diene rubbers can be used. Examples of the conjugated diene rubbers include, but are not limited to, isoprene-isobutylene rubber, polyisoprene rubber, polybutadiene rubber, styrene-butadiene rubber, styrene-isoprene rubber, and propylene-butylene rubber.

[0080] [Olefin-based elastomer] In addition, according to the required performance of the adhesive layer, olefin-based elastomers can be used. As the olefin-based elastomers, those having a Tg of -10°C or lower are preferably used, for example, but are not limited thereto.

[0081] [Wax] The adhesive layer may contain wax as required. Examples of the wax include, but are not limited to, paraffin wax, microcrystalline wax, and low molecular weight polyethylene wax, which can be added. The content of the wax in the adhesive layer is preferably 2 to 10% by mass, more preferably 5 to 10% by mass. The melting point of the wax is preferably 50°C to 110°C, more preferably 65°C to 110°C, still more preferably 70°C to 110°C, and even more preferably 75°C to 110°C. At this time, the softening point of the tackifier used in combination is preferably 70°C or higher, more preferably 80°C or higher.

[0082] [Light stabilizer] The adhesive layer may contain a light stabilizer as required. Examples of the light stabilizer include, but are not limited to, benzotriazole-based ultraviolet absorbers such as 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, 2-(2'-hydroxy-3',5'-t-butylphenyl) benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole; benzophenone-based ultraviolet absorbers such as 2-hydroxy-4-methoxybenzophenone; hindered amine light stabilizers, and the like.

[0083] <Fine particle filler> The adhesive layer may further contain a fine particle filler as other additives. The fine particle filler may be any commonly used one and is not particularly limited. Examples of the fine particle filler include, but are not limited to, mica, calcium carbonate, kaolin, talc, titanium oxide, diatomaceous earth, urea resin, styrene beads, fired clay, starch, and the like. These shapes are preferably spherical, and their dimensions (diameter in the case of spherical) are not particularly limited.

[0084] (Base material layer) The base material layer of the pressure-sensitive adhesive film of this embodiment is mainly composed of an olefin resin. Here, the main component means 50% by mass or more in the base material layer. Examples of the olefin resin constituting the base material layer include resins obtained by polymerizing one or more monoolefins by a high-pressure method or a low-pressure method. Specifically, polyethylene, polypropylene, polybutene-1, and poly-4-methylpentene-1 can be preferably used. This olefin resin may be either a homopolymer or a copolymer. When the olefin resin constituting the base material layer is a copolymer, examples of the monomer copolymerizable with the monoolefin constituting the copolymer include linear α-olefins such as ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, etc., branched α-olefins such as 4-methylpentene-1, 2-methylpropene-1, 3-methylpentene-1, 5-methylhexene-1, 4-methylhexene-1, 4,4-dimethylpentene-1, etc., monocarboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, etc., dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid and their monoesters, acrylic acid or methacrylic acid esters such as methyl methacrylate, methyl acrylate, ethyl acrylate, etc., vinyl esters of saturated carboxylic acids such as vinyl acetate, vinyl propionate, etc., aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, etc., acid anhydrides such as maleic anhydride, itaconic anhydride, citraconic anhydride, aconitic anhydride, etc., α,β-unsaturated nitriles such as acrylonitrile, methacrylonitrile, etc., diene monomers such as 1,4-hexadiene, dicyclopentadiene, ethylidene norbornene, etc., or acrylamide, methacrylamide, maleimide, etc. These monomers copolymerizable with other monomers may be used alone or in combination of two or more. Also, the copolymer may be any of random type, block type, graft type, or a mixed type thereof.

[0085] Preferred copolymers used as the olefin resin constituting the base material layer include, but are not limited to, for example, propylene-ethylene copolymer, propylene-butene-1 copolymer, butene-1-ethylene copolymer, propylene-ethylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-n-butyl acrylate copolymer, etc. In addition, the melt flow rate (MFR) of the olefin resin constituting the base material layer, measured at 230°C under a load of 21.2 N, is preferably 0.01 to 100 g / 10 min, and more preferably 0.1 to 80 g / 10 min. Also, the base material layer may be composed of only one type of olefin resin, or may be composed of a mixture of two or more types of olefin resins. Furthermore, the base material layer may be a single layer or may be a multilayer of two or more layers. Also, it is possible to select a foamed layer as the base material layer, which is preferable as various protective films for packaging protective films and tapes, building materials, household appliances, electronic components, etc.

[0086] 〔Manufacturing method of the adhesive film〕 The adhesive film of this embodiment is a film having a laminated structure, including a base material layer and an adhesive layer disposed on one or both sides of the base material layer. Therefore, using the olefin resin, which is the raw material constituting the two layers, and the block copolymer composition of this embodiment, which is the constituent material of the adhesive layer, this laminated structure is formed by a generally adopted lamination method or the like, thereby producing the film. Specifically, from the viewpoint of simplifying the manufacturing process, etc., it is preferable to co-extrusion mold the base material layer and the adhesive layer using a melt co-extrusion device or the like, so that an adhesive layer is disposed on at least one side of the base material layer made of an olefin resin to form a laminated structure. In addition, when a foamed layer is selected as the base material layer, an appropriate method among the extrusion lamination method or the co-extrusion method can be selected according to the foaming ratio. As the melt co-extrusion device, any device having a plurality of extruders and equipped with a feed block type or a multi-layer type die can be used, and both a T-die type and an inflation type can be used. In addition, when manufacturing the adhesive film using a take-up device and a winding device, it may be preferable to use a device in which various devices such as non-sticking treatment are applied as required.

Examples

[0087] Hereinafter, the present invention will be described in detail with specific examples and comparative examples, but the present invention is not limited to the following examples. In addition, in the examples and comparative examples, the properties and physical properties of the polymer were measured by the following methods.

[0088] [(1): Physical properties of block copolymer composition] <(1-1): Weight-average molecular weight> The weight-average molecular weights of component (A) and component (B) were determined based on the calibration curve obtained from the measurement of commercially available standard polystyrene (prepared using the peak molecular weight of standard polystyrene) according to the measurement conditions described below, based on the molecular weight of the peak of the chromatogram. First, a single peak with the lowest peak top molecular weight in the range of molecular weight of 20,000 or more and having an area ratio calculated by the peak splitting described below of 0.1 or more with respect to the total peak area of the block copolymer composition was defined as component (A), and all peaks in the higher molecular weight range were defined as component (B). The weight-average molecular weights of component (A) and component (B) were determined by vertical division to the baseline at the inflection point between each peak of the GPC curve using the system software described below. Here, the inflection point between the peaks of component (A) and component (B) was defined as the lowest point (valley peak) in the most vertical direction between adjacent peaks. Also, when the lowest points were continuous, the midpoint was used. Based on the aforementioned inflection points, vertical division was performed using the waveform separation function in the above-described system software, and after division, each weight-average molecular weight and area ratio were calculated. (Measurement conditions) GPC; ACQUITY APC system (manufactured by Waters K.K., Japan) System (measurement / analysis) software; Empower3 Detector; RI Refractive index unit full scale; 500 μRIU Output full scale; 2000 mV Sampling rate; 10 points / sec Column; ACQUITY APC XT125 (4.6 mm × 150 mm); 1 piece ACQUITY APC XT200 (4.6 mm × 150 mm); 1 piece ACQUITY APC XT900 (4.6 mm × 150 mm); 1 piece ACQUITY APC XT450 (4.6 mm × 150 mm); 1 piece Solvent; THF Flow rate; 1.0 mL / min Concentration; 0.1 mg / mL Column temperature; 40 °C Injection volume; 20 μL

[0089] <(1 - 2): Content of component (A) and component (B)> The ratio of the area of component (A) to the total peak area of the elution curve measured in (1 - 1) was defined as the content of component (A). Also, the ratio of the area of all peaks in the molecular weight range higher than that of component (A) to the total peak area of the elution curve measured in (1 - 1) was defined as the content of component (B).

[0090] <(1 - 3): Content of component (B - 1), (B - 2), and (B - 3)> In component (B), a peak with a peak top within 1.5 times or more and less than 2.5 times the weight - average molecular weight of component (A) was defined as component (B - 1), a peak with a peak top within 2.5 times or more and less than 3.5 times the weight - average molecular weight of component (A) was defined as component (B - 2), and a peak with a peak top within 3.5 times or more and less than 4.5 times the weight - average molecular weight of component (A) was defined as component (B - 3). The ratio of the peak area of each component to the total peak area of the elution curve measured in (1 - 1) was defined as the content of each component. Regarding the peak areas, weight average molecular weights, and weight average molecular weight ratios of component (B-1), component (B-2), and component (B-3), after GPC measurement using the above-mentioned apparatus and conditions, they were determined by vertically dividing the GPC curve at the inflection points between each peak up to the baseline using the above-mentioned system software. Here, the inflection points between each peak of component (B-1), (B-2), and (B-3) were taken as the lowest points (valley peaks) that were the lowest in the vertical direction between adjacent peaks. Also, when the lowest points were continuous, the midpoint between them was taken. Using the above-mentioned inflection points, vertical division was performed using the waveform separation function in the above-mentioned system software, and after division, each weight average molecular weight, each weight average molecular weight ratio, and peak area were calculated.

[0091] <(1-4): Content of vinyl aromatic monomer units contained in polymer block (Ar) with respect to the entire block copolymer composition> The content of vinyl aromatic monomer units contained in polymer block (Ar) with respect to the entire block copolymer composition was calculated using the mass of the polymer mainly composed of vinyl aromatic monomer units determined by the method of oxidative decomposition of the block copolymer composition before hydrogenation using osmium tetroxide as a catalyst and t-butyl hydroperoxide (the method described in I.M. KOLTHOFF, et al., Polym. Sci. 1, 429 (1946)) (hereinafter referred to as the osmium tetroxide decomposition method). However, vinyl aromatic compounds with an average degree of polymerization of about 30 or less were excluded.

[0092] <(1-5): Content of vinyl aromatic monomer units contained in the block copolymer composition> A certain amount of the block copolymer composition was dissolved in chloroform and measured with an ultraviolet spectrophotometer (UV-2450 manufactured by Shimadzu Corporation). The content of vinyl aromatic monomer units (styrene) was calculated using a calibration curve from the peak intensity of the absorption wavelength (262 nm) attributed to the vinyl aromatic compound component (styrene).

[0093] <(1-6): Average vinyl bond amount in conjugated diene monomer units before hydrogenation> The average vinyl bond amount of the conjugated diene monomer units before hydrogenation in component (A) and component (B) was calculated by the Hampton method using an infrared spectrophotometer (FT / IR-230, manufactured by JASCO Corporation) with the block copolymer composition before hydrogenation.

[0094] <(1-7): Hydrogenation rate> The average hydrogenation rate of the double bonds of the conjugated diene monomer units in the block copolymer was measured under the following conditions using a nuclear magnetic resonance apparatus (NMR). First, a large amount of methanol was added to the reaction solution after the hydrogenation reaction to precipitate and recover the block copolymer. Next, the block copolymer was extracted with acetone, and the extract was dried under vacuum and 1 used as a sample for 1H-NMR measurement 1 The conditions for 1H-NMR measurement are described below. (Measurement conditions) Measuring instrument: JNM-LA400 (manufactured by JEOL) Solvent: Deuterated chloroform Measurement sample: Extracted samples before and after hydrogenating the polymer Sample concentration: 50 mg / mL Observation frequency: 400 MHz Chemical shift standard: TMS (tetramethylsilane) Pulse delay: 2.904 seconds Number of scans: 64 times Pulse width: 45° Measurement temperature: 26 °C

[0095] Also, for "the content of the vinyl aromatic monomer units contained in the polymer block (Ar) with respect to the entire block copolymer composition", "the content of the vinyl aromatic monomer units contained in the block copolymer composition", and "the average vinyl bond amount in the conjugated diene monomer units", it is possible to measure using a nuclear magnetic resonance apparatus even in the state after hydrogenation by the method described in Y. Tanaka, et al., RUBBER CHEMISTRY and TECHNOLOGY 54, 685 (1981).

[0096] 〔(2): Properties of the block copolymer composition〕 <(2-1): Melt flow rate> In accordance with ISO 1133, the MFR of the block copolymer was measured under the conditions of a temperature of 230 °C and a load of 2.16 kg.

[0097] <(2-2): Blocking property> The blocking resistance of the pellets of the hydrogenated block copolymer composition was measured by the following method. 300 g of sample pellets of the same shape (cylindrical shape with a diameter of about 4 mm × 4 mm) made of the hydrogenated block copolymer composition were put into a metal cylinder with a diameter of 7.5 cm, and a weight of 3000 g was placed on it. In this state, after heating in a gear oven heated to 60 °C for 72 hours, the pellets solidified into a cylindrical shape were returned to room temperature, and the stress when compressed at a speed of 300 mm / min using a precision universal testing machine (AUTOGRAPH AGS-X manufactured by Shimadzu) was measured. The blocking property was judged to be good at 6.0 kgf or less and very good at 4.0 kgf or less.

[0098] <(2-3): Adhesive strength of the adhesive film> Using a polycarbonate plate as the adherend, it was measured in accordance with JIS Z0237. The adhesive strength was judged to be practically applicable at 50 g / 25 mm or more, good at 60 g / 25 mm or more, and very good at 70 g / 25 mm or more.

[0099] 〔Block copolymer composition〕 (Preparation of hydrogenation catalyst) In the examples and comparative examples described below, the hydrogenation catalyst used when preparing the block copolymer composition was prepared by the following method. The reaction vessel equipped with a stirring device was purged with nitrogen, and 1 L of dried and purified cyclohexane was charged therein. Next, 100 mmol of bis(η5-cyclopentadienyl)titanium dichloride was added. While stirring this thoroughly, an n-hexane solution containing 200 mmol of trimethylaluminum was added, and the reaction was carried out at room temperature for about 3 days. Thereby, a hydrogenation catalyst was obtained.

[0100] (Preparation of block copolymer composition) <Example 1, Block copolymer composition 1> Using a stirring device with an internal volume of 100 L and a tank-type reactor with a jacket, batch polymerization was carried out in the following manner. As a first step, 36 L of cyclohexane and 7 parts by mass of styrene monomer were charged into the reactor. After adjusting the temperature to 30 °C, 0.073 part by mass of n-butyllithium (hereinafter also referred to as "Bu-Li") and 0.5 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added with respect to the total amount of butadiene monomer and styrene monomer charged into the reactor (hereinafter referred to as "total monomers"). Polymerization was started while adjusting the temperature inside the reactor to 45 °C. As a second step, 20 parts by mass of styrene monomer and 67 parts by mass of butadiene monomer were continuously charged over 60 minutes, and the reaction was continued while adjusting the temperature inside the reactor to 80 °C. As a third step, 6 parts by mass of styrene monomer was charged over 3 minutes, and then the reaction was continued while adjusting the temperature inside the reactor to 80 °C for another 5 minutes. As a fourth step, 0.08 mol of tetraethoxysilane was added per 1 mol of Bu-Li and subjected to a coupling reaction for 10 minutes, and 0.8 mol of methanol was added per 1 mol of Bu-Li to deactivate the reaction. Furthermore, the hydrogenation catalyst prepared as described above was added at 80 ppm on a Ti basis per 100 parts by mass of the block copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.8 MPa and an average temperature of 85 °C. To the obtained block copolymer solution, 0.3 part by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added per 100 parts by mass of the above block copolymer, and the mixture was thoroughly mixed. Thereafter, the solvent was removed by heating, and melt-kneading was carried out at a set temperature of 220 °C using a twin-screw extruder ("TEX-30αII" manufactured by Japan Steel Works, cylinder diameter 30 mm) to obtain pellets of the thermoplastic elastomer composition. To the pellets, 1200 ppm of calcium stearate was added as an antiblocking agent to obtain Block Copolymer Composition 1.

[0101] (Example 2: Block Copolymer Composition 2) Block Copolymer Composition 2 was obtained in the same manner as Block Copolymer Composition 1, except that 0.75 mol of 2,2-bis(2-tetrahydrofuryl)propane was added per 1 mol of Bu-Li in the first step.

[0102] (Example 3: Block Copolymer Composition 3) Block Copolymer Composition 3 was obtained in the same manner as Block Copolymer Composition 1, except that 0.068 part by mass of Bu-Li and 0.75 mol of 2,2-bis(2-tetrahydrofuryl)propane were added per 1 mol of Bu-Li in the first step.

[0103] (Example 4: Block Copolymer Composition 4) Block Copolymer Composition 4 was obtained in the same manner as Block Copolymer Composition 1, except that 0.077 part by mass of Bu-Li and 0.75 mol of 2,2-bis(2-tetrahydrofuryl)propane were added per 1 mol of Bu-Li in the first step, and the temperature inside the reactor was adjusted to 70 °C in the second step.

[0104] (Example 5: Block Copolymer Composition 5) Block Copolymer Composition 5 was obtained in the same manner as Block Copolymer Composition 1, except that 0.082 part by mass of Bu-Li and 0.75 mol of 2,2-bis(2-tetrahydrofuryl)propane were added per 1 mol of Bu-Li in the first step.

[0105] (Example 6: Block copolymer composition 6) In the first step, 8 parts by mass of styrene monomer, 0.093 parts by mass of Bu-Li, and 0.42 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the second step, 18 parts by mass of styrene monomer were added, and in the third step, 7 parts by mass of styrene monomer were added. A block copolymer composition 6 was obtained in the same manner as block copolymer composition 1 except for the above.

[0106] (Example 7: Block copolymer composition 7) In the first step, 0.75 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li was added. In the fourth step, tetraethoxysilane was changed to dimethyldichlorosilane, and 0.124 mol was added. A block copolymer composition 7 was obtained in the same manner as block copolymer composition 1 except for the above.

[0107] (Example 8: Block copolymer composition 8) In the first step, 0.081 parts by mass of Bu-Li and 0.75 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the fourth step, tetraethoxysilane was changed to trichlorosilane, and 0.066 mol was added. A block copolymer composition 8 was obtained in the same manner as block copolymer composition 1 except for the above.

[0108] (Example 9: Block copolymer composition 9) In the first step, 0.095 parts by mass of Bu-Li and 0.75 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the fourth step, tetraethoxysilane was changed to tetrachlorosilane, and 0.051 mol was added. A block copolymer composition 9 was obtained in the same manner as block copolymer composition 1 except for the above.

[0109] (Example 10: Block copolymer composition 10) In the first step, 0.083 parts by mass of Bu-Li and 0.75 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the fourth step, 0.059 mol of tetraethoxysilane was added, and block copolymer composition 10 was obtained in the same manner as block copolymer composition 1 except that the coupling was carried out for 40 minutes.

[0110] (Example 11: Block copolymer composition 11) In the first step, 0.100 parts by mass of Bu-Li and 0.75 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the fourth step, 0.200 mol of tetraethoxysilane was added, and 0.5 mol of methanol was added to deactivate the reaction. Block copolymer composition 11 was obtained in the same manner as block copolymer composition 1.

[0111] (Example 12: Block copolymer composition 12) In the first step, 0.090 parts by mass of Bu-Li and 0.75 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the fourth step, 0.160 mol of tetraethoxysilane was added, and 0.6 mol of methanol was added to deactivate the reaction. Block copolymer composition 12 was obtained in the same manner as block copolymer composition 1.

[0112] (Example 13: Block copolymer composition 13) In the first step, 0.087 parts by mass of Bu-Li and 0.75 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the fourth step, 0.140 mol of tetraethoxysilane was added, and 0.65 mol of methanol was added to deactivate the reaction. Block copolymer composition 13 was obtained in the same manner as block copolymer composition 1.

[0113] (Example 14: Block copolymer composition 14) In the first step, 0.080 part by mass of Bu-Li and 0.75 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the fourth step, 0.116 mol of tetraethoxysilane was added, and 0.7 mol of methanol was added to deactivate the reaction. A block copolymer composition 14 was obtained in the same manner as block copolymer composition 1 except for the above.

[0114] (Example 15: Block copolymer composition 15) In the first step, 0.065 part by mass of Bu-Li and 0.75 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the fourth step, 0.052 mol of tetraethoxysilane was added, and 0.9 mol of methanol was added to deactivate the reaction. A block copolymer composition 15 was obtained in the same manner as block copolymer composition 1 except for the above.

[0115] (Example 16: Block copolymer composition 16) In the first step, 0.065 part by mass of Bu-Li and 0.75 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the fourth step, 0.040 mol of tetraethoxysilane was added, and 0.9 mol of methanol was added to deactivate the reaction. A block copolymer composition 16 was obtained in the same manner as block copolymer composition 1 except for the above.

[0116] (Example 17: Block copolymer composition 17) A block copolymer composition 17 was obtained in the same manner as block copolymer composition 1 except that in the first step, 0.112 part by mass of Bu-Li and 0.35 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added.

[0117] (Example 18: Block copolymer composition 18) A block copolymer composition 17 was obtained in the same manner as block copolymer composition 1 except that in the first step, 0.137 part by mass of Bu-Li and 0.25 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added.

[0118] (Comparative Example 1: Block Copolymer Composition 19) In the first step, 0.75 mol of 2,2 - bis(2 - tetrahydrofuryl)propane was added per 1 mol of Bu - Li. In the fourth step, tetraethoxysilane was not added, and 1.0 mol of methanol was added per 1 mol of Bu - Li. A block copolymer composition 19 was obtained in the same manner as block copolymer composition 1 except for the above.

[0119] (Comparative Example 2: Block Copolymer Composition 20) In the first step, 0.065 part by mass of Bu - Li and 0.75 mol of 2,2 - bis(2 - tetrahydrofuryl)propane were added per 1 mol of Bu - Li. In the second step, the temperature inside the reactor was adjusted to 70°C. In the fourth step, tetraethoxysilane was not added, and 1.0 mol of methanol was added per 1 mol of Bu - Li. A block copolymer composition 20 was obtained in the same manner as block copolymer composition 1 except for the above.

[0120] (Comparative Example 3: Block Copolymer Composition 21) In the first step, 0.113 part by mass of Bu - Li and 0.75 mol of 2,2 - bis(2 - tetrahydrofuryl)propane were added per 1 mol of Bu - Li. In the fourth step, 0.260 mol of tetraethoxysilane was added, and 0.35 mol of methanol was added to deactivate the reaction. A block copolymer composition 21 was obtained in the same manner as block copolymer composition 1 except for the above.

[0121] (Comparative Example 4: Block Copolymer Composition 22) In the first step, 0.058 part by mass of Bu - Li and 0.75 mol of 2,2 - bis(2 - tetrahydrofuryl)propane were added per 1 mol of Bu - Li. In the fourth step, 0.020 mol of tetraethoxysilane was added, and 0.95 mol of methanol was added to deactivate the reaction. A block copolymer composition 22 was obtained in the same manner as block copolymer composition 1 except for the above.

[0122] (Comparative Example 5: Block Copolymer Composition 23) In the first step, 17 parts by mass of styrene monomer, 0.170 parts by mass of Bu-Li, and 0.25 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the second step, 9 parts by mass of styrene monomer, 70 parts by mass of butadiene monomer were added. In the third step, 4 parts by mass of styrene monomer were added. In the fourth step, tetraethoxysilane was changed to stannic chloride, 0.4 mol was added, 0.2 mol of methanol was added to deactivate the reaction, and block copolymer composition 23 was obtained in the same manner as block copolymer composition 1 except that the hydrogenation reaction was not carried out.

[0123] (Comparative Example 6: Block Copolymer Composition 24) In the first step, 12 parts by mass of styrene monomer, 0.090 parts by mass of Bu-Li, and 0.30 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the second step, 10 parts by mass of styrene monomer, 70 parts by mass of butadiene monomer were added. In the third step, 8 parts by mass of styrene monomer were added. In the fourth step, tetraethoxysilane was changed to stannic chloride, 0.3 mol was added, 0.4 mol of methanol was added to deactivate the reaction, and block copolymer composition 24 was obtained in the same manner as block copolymer composition 1 except that the hydrogenation reaction was not carried out.

[0124] (Comparative Example 7: Block Copolymer Composition 25) In the first step, 10 parts by mass of styrene monomer, 0.085 parts by mass of Bu-Li, and 0.30 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the second step, 13 parts by mass of styrene monomer, 74 parts by mass of butadiene monomer were added. In the third step, 3 parts by mass of styrene monomer were added. In the fourth step, tetraethoxysilane was changed to stannic chloride, 0.1 mol was added, and block copolymer composition 25 was obtained in the same manner as block copolymer composition 1 except that the hydrogenation reaction was not carried out.

[0125] (Comparative Example 8: Block Copolymer Composition 26) In the first step, 20 parts by mass of styrene monomer, 0.140 parts by mass of Bu-Li, and 0.60 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the second step, 10 parts by mass of styrene monomer and 70 parts by mass of butadiene monomer were added. In the third step, no styrene monomer was added. In the fourth step, tetraethoxysilane was changed to methyldichlorosilane, and 0.3 mol was added. 0.4 mol of methanol was added. Block copolymer composition 26 was obtained in the same manner as block copolymer composition 1 except for the above.

[0126] (Comparative Example 9: Block Copolymer Composition 27) In the first step, 13 parts by mass of styrene monomer, 0.065 parts by mass of Bu-Li, and 0.75 mol of 2,2-di(2-tetrahydrofuryl)propane per 1 mol of Bu-Li were added. In the third step, no styrene monomer was added. In the fourth step, tetraethoxysilane was changed to methyldichlorosilane, and 0.1 mol was added. 0.8 mol of methanol was added. Block copolymer composition 27 was obtained in the same manner as block copolymer composition 1 except for the above. Since no styrene monomer was added in the third step, components (A) and (B) do not have two styrene blocks.

[0127] 〔Preparation of Adhesive Film〕 Using polyethylene (manufactured by Mitsubishi Chemical Corporation, YF30) as the base material layer and the above-described block copolymer compositions 1 to 7 as the adhesive layer, the base material layer and the adhesive layer were coextruded and molded by a two-layer coextrusion apparatus equipped with a feed block type T-die so that the thickness of the base material layer was 100 μm and the thickness of the adhesive layer was 15 μm to produce an adhesive film.

[0128] The block copolymer compositions and the adhesive films obtained as described above were evaluated by the above method. The evaluation results are shown in Tables 1 to 3 below.

[0129]

Table 1

[0130]

Table 2

[0131]

Table 3

[0132] In Examples 1 to 18, Comparative Examples 1 to 2, and 4, all show practically sufficient adhesive force. However, in Comparative Examples 3 and 5 to 9, the adhesive force is low, and in Comparative Examples 1 to 9, the blocking property is poor. It was found that in Examples 1 to 18, the balance between the adhesive force and the blocking performance is good.

Industrial Applicability

[0133] The block copolymer composition of the present invention has industrial applicability as a material for plastic modifiers, asphalt modifiers, automotive parts (automotive interior materials, automotive exterior materials), various containers such as food packaging containers, household electrical appliances, medical device parts, industrial parts, toys, footwear, adhesives, surface protection films for various products and parts, etc.

Claims

1. Component (A) is 50% by mass or more and 90% by mass or less, A block copolymer composition comprising 10% by mass or more and 50% by mass or less of component (B), The component (A) is A polymer block (Ar) based on at least two vinyl aromatic monomer units; and a copolymer block (R) containing at least one vinyl aromatic monomer unit and a conjugated diene monomer unit, and having a weight average molecular weight of 80,000 or more and 200,000 or less, The component (B) is A polymer block (Ar) based on at least two vinyl aromatic monomer units; and a copolymer block (R) containing at least one vinyl aromatic monomer unit and a conjugated diene monomer unit, and having a weight average molecular weight of 120,000 or more and 900,000 or less, the total content of vinyl aromatic monomer units in the polymer block (Ar) contained in the component (A) and the component (B) is 5.0 mass% or more and 20.0 mass% or less of the entire block copolymer composition, the total content of vinyl aromatic monomer units contained in the component (A) and the component (B) is 20.0 mass% or more and 45.0 mass% or less of the entire block copolymer composition, The average hydrogenation rate of the conjugated diene monomer units contained in the component (A) and the component (B) is 90 mol % or more. Block copolymer compositions.

2. The component (B) is Component (B-1) having a weight average molecular weight ratio to the weight average molecular weight of component (A) of 1.5 or more and less than 2.5; A component (B-2) having a weight average molecular weight ratio to the weight average molecular weight of the component (A) of 2.5 or more and less than 3.5; Component (B-3) having a weight average molecular weight ratio to the weight average molecular weight of component (A) of 3.5 or more and less than 4.5; At least one selected from the group consisting of: The block copolymer composition of claim 1 .

3. the area ratio of each of the components (B-1) and (B-2) in a GPC elution curve is greater than the area ratio of the component (B-3) in a GPC elution curve; The block copolymer composition of claim 2.

4. The component (A) is A block copolymer represented by (Ar-R-Ar) and / or (Ar-R-Ar)X, The component (B-1) is (Ar-R-Ar) 2 represented by X, The component (B-2) is (Ar-R-Ar) 3 represented by X, The component (B-3) is (Ar-R-Ar) 4 represented by X, Ar represents a polymer block mainly composed of vinyl aromatic monomer units, R represents a copolymer block containing a vinyl aromatic monomer unit and a conjugated diene monomer unit, X represents a residue of a coupling agent or a residue of a polymerization initiator; The block copolymer composition of claim 2.

5. The component (A) is is a block copolymer represented by (R-Ar-R-Ar) and / or (R-Ar-R-Ar)X, The component (B-1) is (R-Ar-R-Ar) 2 represented by X, The component (B-2) is (R-Ar-R-Ar) 3 represented by X, The component (B-3) is (R-Ar-R-Ar) 4 represented by X, Ar represents a polymer block mainly composed of vinyl aromatic monomer units, R represents a copolymer block containing a vinyl aromatic monomer unit and a conjugated diene monomer unit, X represents a residue of a coupling agent or a residue of a polymerization initiator; The block copolymer composition of claim 2.

6. The component (A) is A block copolymer represented by (D-Ar-R-Ar) and / or (D-Ar-R-Ar)X, The component (B-1) is (D-Ar-R-Ar) 2 represented by X, The component (B-2) is (D-Ar-R-Ar) 3 represented by X, The component (B-3) is (D-Ar-R-Ar) 4 represented by X, Ar represents a polymer block mainly composed of vinyl aromatic monomer units, R represents a copolymer block containing a vinyl aromatic monomer unit and a conjugated diene monomer unit, D represents a polymer block mainly composed of a conjugated diene monomer, X represents a residue of a coupling agent or a residue of a polymerization initiator; The block copolymer composition of claim 2.

7. the average vinyl bond content of the conjugated diene monomer units before hydrogenation in the components (A) and (B) is 40% or more; The block copolymer composition of claim 1 .

8. The component (A) is contained in an amount of 70% by mass or more and 90% by mass or less. The block copolymer composition of claim 1 .

9. An adhesive film comprising an adhesive layer comprising the block copolymer composition according to claim 1 and disposed on at least one surface of a base layer mainly composed of an olefin-based resin.

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