Block copolymer and adhesive

Abstract

To provide a block copolymer capable of exhibiting moldability, adhesive performance and expandability in a well-balanced manner.SOLUTION: There is provided a block copolymer in which a composition ratios (molar ratios) in a polymer of structural units represented by following formulas (1) to (4) are defined as p, q, r and s, respectively, a value α represented by an expression (i) is 0.75 or more, wherein the block copolymer contains 10 mass% or more of a polymer (A1) having a multi-branched structure having 4 or more polymeric chains in which the polymeric chains have a polymeric block A containing 70 mass% or more of a structural unit derived from a conjugated diene compound and a polymer block B containing 70 mass% or more of a structural unit derived from an aromatic vinyl compound and the block copolymer and has a functional group F containing at least one kind of element selected from a group consisting of nitrogen, silicon, oxygen and sulfur in a part or all of the terminals in 4 or more polymeric chains. α=(p+(0.5×r)) / (p+q+(0.5×r)+s) (i).SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] Conventionally, in order to protect the surfaces of various members such as optical members, metal plates, and synthetic resin plates from contamination and damage, the surfaces of the members have been covered with surface protection films. Further, a hydrogenated conjugated diene polymer has been proposed as a material for forming an adhesive layer such as a surface protection film (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses using, as a material for an adhesive layer, a hydrogenated diene copolymer obtained by hydrogenating a block copolymer containing at least two polymer blocks mainly composed of an aromatic vinyl compound and a copolymer block of an aromatic vinyl compound and a conjugated diene compound, and using, as a material for an adhesive layer, a hydrogenated diene copolymer obtained by hydrogenating a block copolymer containing at least two polymer blocks mainly composed of a conjugated diene compound and having a vinyl bond content of less than 20% and a copolymer block of an aromatic vinyl compound and a conjugated diene compound. In Patent Document 1, by setting the total aromatic vinyl compound unit content of the hydrogenated diene copolymer to a predetermined ratio, the vinyl bond content derived from the conjugated diene compound to a predetermined ratio, etc., it is disclosed in Patent Document 1 that an adhesive film excellent in moldability and adhesiveness can be obtained.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] While the hydrogenated diene copolymer described in Patent Document 1 has good moldability, its adhesion performance (e.g., peel adhesion strength, initial adhesiveness (tackiness) to an adherend, and property of maintaining adhesive force after attachment (low adhesive creep property)) is not yet sufficient. In particular, when applied to a surface protection film for optical use, it is necessary to have excellent adhesion performance to a polar resin substrate such as a polycarbonate substrate. Further, as the material for the adhesive layer, for example, when formed into a film roll for adhesive film applications, it is required that the force (unwinding force) required for rewinding is small. However, it is difficult to develop a material that exhibits all these characteristics in a well-balanced manner, and further improvement is required.

[0006] The present invention has been made in view of the above problems, and a main object thereof is to provide a block copolymer capable of exhibiting moldability, adhesion performance, and unwindability in a well-balanced manner.

Means for Solving the Problems

[0007] The present invention provides the following block copolymer and adhesive.

[0008] [1] When the constituent ratios (molar ratios) of the structural units represented by the following formula (1), the structural units represented by the following formula (2), the structural units represented by the following formula (3), and the structural units represented by the following formula (4) in the polymer are p, q, r, and s, respectively, a block copolymer in which the value α represented by the following mathematical formula (i) is 0.75 or more, wherein the block copolymer contains 10% by mass or more of a polymer (A1) having a multi-branched structure with 4 or more polymer chains, and the polymer chains have a polymer block A containing 70% by mass or more of a structural unit derived from a conjugated diene compound and a polymer block B containing 70% by mass or more of a structural unit derived from an aromatic vinyl compound, and at least a part or all of the terminals of the 4 or more polymer chains have a functional group F containing at least one element selected from the group consisting of nitrogen, silicon, oxygen, and sulfur. α=(p+(0.5×r)) / (p+q+(0.5×r)+s) …(i)

Chemical formula

[0009] [2] An adhesive obtained by using the block copolymer of [1] above.

Advantages of the Invention

[0010] According to the block copolymer of the present invention, an adhesive excellent in molding processability, adhesive performance, and spreadability can be obtained.

Modes for Carrying Out the Invention

[0011] Hereinafter, matters related to the implementation of the present invention will be described in detail. In this specification, a numerical range described using "~" represents a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0012] ≪Block Copolymer≫ The block copolymer of the present disclosure (hereinafter, also referred to as "[A] block copolymer") is a conjugated diene-based block copolymer including a polymer block A mainly composed of structural units derived from a conjugated diene compound and a polymer block B mainly composed of structural units derived from an aromatic vinyl compound. When the composition ratios (molar ratios) of the structural units represented by the following formula (1), the structural units represented by the following formula (2), the structural units represented by the following formula (3), and the structural units represented by the following formula (4) are p, q, r, and s, respectively, the value α represented by the following mathematical formula (i) is 0.75 or more. α = (p + (0.5 × r)) / (p + q + (0.5 × r) + s) …(i)

Chemical Formula

[0013] [A] block copolymer includes a branched polymer which is a polymer having a multi-branched structure. Specifically, [A] block copolymer is a polymer chain P 1The polymer (A1), which is a branched polymer having four or more polymer chains, is contained in an amount of 10% by mass or more with respect to the [A] block copolymer (100% by mass). Each of the four or more polymer chains P 1 of the polymer (A1) has a polymer block A and a polymer block B. Some or all of the terminals in these four or more polymer chains P 1 have a functional group F containing at least one element selected from the group consisting of nitrogen, silicon, oxygen, and sulfur. Hereinafter, the configuration of the [A] block copolymer and its production method will be described in detail.

[0014] <Polymer block A> The polymer block A is a segment mainly composed of structural units derived from a conjugated diene compound. Examples of the conjugated diene compound constituting the polymer block A include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, β-farnesene, and chloroprene. Among these, 1,3-butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethyl-1,3-butadiene are preferable, and 1,3-butadiene and isoprene are more preferable in terms of being industrially applicable and capable of obtaining a polymer exhibiting excellent physical properties. As the conjugated diene compound, one of these can be used alone or in combination of two or more.

[0015] The polymer block A may be a segment consisting only of a conjugated diene compound, or may further contain structural units derived from a monomer different from the conjugated diene compound (hereinafter also referred to as "other monomer a"). The other monomer a is not particularly limited as long as it is a monomer copolymerizable with the conjugated diene compound, and examples thereof include aromatic vinyl compounds, acrylonitrile, methyl (meth)acrylate, and ethyl (meth)acrylate.

[0016] The polymer block A contains, based on all the structural units constituting the polymer block A, 70% by mass or more of structural units derived from a conjugated diene compound. When the proportion of the structural units derived from the conjugated diene compound in the polymer block A is less than 70% by mass, the adhesive strength is insufficient, and particularly the initial adhesiveness (tackiness) tends to be low. In addition, a crystalline block segment showing a structure similar to low-density polyethylene (LDPE) by hydrogenation cannot be sufficiently introduced into the [A] block copolymer, and the adhesiveness tends to increase, or when used as a film roll in the application of an adhesive film, the force (unwinding force) required for rewinding tends to increase. From these viewpoints, the proportion of the structural units derived from the conjugated diene compound in the polymer block A is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 98% by mass or more.

[0017] The polymer block A is preferably a segment in which the value β represented by the following mathematical formula (ii) exceeds 0.20. When the value β in the polymer block A exceeds 0.20, it is suitable in terms of the fact that the [A] block copolymer does not become too hard and the adhesive strength can be increased, and the fact that an increase in the unwinding force can be suppressed. β = (p + q) / (p + q + (0.5×r) + s) …(ii) From the above viewpoints, the value β in the polymer block A is preferably 0.30 or more, more preferably 0.40 or more, still more preferably 0.50 or more, and particularly preferably exceeds 0.60. In addition, the vinyl bond content of the polymer block A is, from the viewpoint of ensuring moldability, for example, 0.85% or less.

[0018] In the case of a hydrogenated polymer, the value β corresponds to the vinyl bond content (mol%) of the polymer before hydrogenation. The "vinyl bond content" is a value indicating the proportion of the structural units having 1,2-bonds with respect to all the structural units derived from the conjugated diene compound contained in the polymer (or polymer block) before hydrogenation. The vinyl bond content of the polymer before hydrogenation is 1It is a value measured by an H-NMR device. For example, when β = 0.20, it indicates that the vinyl bond content of the polymer (or polymer block) is 20 mol%.

[0019] <Polymer block B> Polymer block B is a segment mainly composed of structural units derived from aromatic vinyl compounds. Examples of the aromatic vinyl compound constituting polymer block B include styrene, tert-butylstyrene, α-methylstyrene, p-methylstyrene, p-ethylstyrene, divinylbenzene, 1,1-diphenylstyrene, vinylnaphthalene, vinylanthracene, N,N-diethyl-p-aminoethylstyrene, vinylpyridine, etc. Among these, styrene is particularly preferred. As the aromatic vinyl compound, one of these can be used alone or in combination of two or more.

[0020] Polymer block B may be a segment consisting only of aromatic vinyl compounds, or may further contain structural units derived from monomers different from aromatic vinyl compounds (hereinafter also referred to as "other monomers b"). The other monomer b is not particularly limited as long as it is a monomer copolymerizable with the aromatic vinyl compound. Examples of the other monomer b include conjugated diene compounds, acrylonitrile, methyl (meth)acrylate, ethyl (meth)acrylate, etc.

[0021] Polymer block B contains structural units derived from aromatic vinyl compounds in an amount of 70% by mass or more based on all the structural units constituting polymer block B. In polymer block B, when the proportion of the structural units derived from aromatic vinyl compounds is less than 70% by mass, the adhesiveness decreases, the adhesive strength to the adherend (especially polar resins such as polycarbonate resins) is insufficient, or the self-supporting property of the adhesive decreases, and adhesive creep tends to occur easily. From such a viewpoint, the proportion of the structural units derived from aromatic vinyl compounds in polymer block B is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 98% by mass or more.

[0022] <Functional group F> A plurality of polymer chains P possessed by the polymer (A1) 1 For these plurality of polymer chains P 1 At a part or all of the terminals thereof, there is a functional group F containing at least one element selected from the group consisting of nitrogen, silicon, oxygen, and sulfur. [A] In a block copolymer, by introducing the functional group F into a part or all of the free terminals of the polymer (A1), the adhesion performance and the moldability can be improved well in balance. The functional group F is preferably introduced at the terminal of the polymer block A or the polymer block B.

[0023] Specific examples of the functional group F include, for example, a primary amino group, a secondary amino group, a tertiary amino group, a nitrogen-containing group in which two hydrogen atoms of the primary amino group are substituted by two protecting groups, a nitrogen-containing group in which one hydrogen atom of the secondary amino group is substituted by one protecting group, an imino group, a nitrogen-containing heterocyclic group (for example, a group having a heterocycle such as a pyridine ring or an imide ring), a hydroxyl group, an oxygen-containing group in which one hydrogen atom of the hydroxyl group is substituted by one protecting group, a thiol group, a sulfur-containing group in which one hydrogen atom of the thiol group is substituted by one protecting group, a hydrocarbyloxysilyl group, and the like. The functional group F is preferably a nitrogen-containing functional group (nitrogen-containing group) especially because of its high effect of improving the adhesiveness to a highly polar adherend and its high effect of improving the developability by suppressing excessive adhesion to a low-polar adherend, and it is particularly preferable to have at least one selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, and an imide group. Further, from the viewpoint of securing reaction points with a modifier (post-modifier) or a crosslinking agent that can be used in a later reaction and improving heat resistance, solvent resistance, suppression of glue residue, and contamination of the adherend by residues, this polymer preferably has at least one of a primary amino group and a secondary amino group at a part or all of the terminals of the polymer block A, and it is particularly preferable to have a plurality of at least one of a primary amino group and a secondary amino group in one molecule.

[0024] <Constitution of the polymer (A1)> One aspect of the polymer (A1) can be a block polymer with excellent adhesion performance. In the reaction with a cross-linking agent capable of reacting with the functional group F, it can more efficiently form a network structure, thereby improving heat resistance, solvent resistance, suppression of glue residue, and stain resistance due to low residue. It is a radial polymer (also called a star polymer) having four or more branched structures. Specifically, it is preferably a polymer having a structure in which four or more polymer chains containing a polymer block A and a polymer block B are bonded to a partial structure derived from a coupling agent. Preferred specific examples of the polymer (A1) include block copolymers having a structure represented by the following formula (5). (P 1 )n-X 1 …(5) (In formula (5), P 1 is a polymer chain having a polymer block A and a polymer block B. X 1 is a partial structure derived from a coupling agent. n is an integer of 4 or more.)

[0025] In the above formula (5), as long as P 1 has a polymer block A and a polymer block B, the number of blocks constituting the polymer chain P 1 and the arrangement of each block are not particularly limited. P 1 is preferably linear.)

[0026] P 1 As the block structure of, for example, an AB-type diblock formed of a polymer block A / polymer block B, an ABA-type triblock formed of a polymer block A / polymer block B / polymer block A, a BAB-type triblock formed of a polymer block B / polymer block A / polymer block B, etc. can be mentioned. Further, P 1 may further have a polymer block C different from the polymer block A and the polymer block B, and may be a polymer chain having 4 or more blocks. Among these, a polymer showing excellent adhesion performance with a smaller number of blocks can be produced, and in terms of excellent productivity, P 1It is preferably an AB-type diblock body, an ABA-type triblock body, or an ABC-type triblock body. From the viewpoint of ensuring moldability and the viewpoint that a network structure can be efficiently formed by a crosslinking agent and an improvement effect on solvent resistance and heat resistance can be expected, n is preferably an integer of 4 to 10, and more preferably 4 to 6.

[0027] In addition, when the polymer chain P 1 has a plurality of polymer blocks A, the vinyl bond content (that is, the value β) of these plurality of polymer blocks A may be the same or different from each other.

[0028] One embodiment of the polymer block C is a segment having a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound. When the polymer (A1) further has such a segment, it is preferable in terms of improving the adhesion performance (adhesion strength, tackiness) or improving the developability, and in terms of improving the vibration damping characteristics. The distribution of the aromatic vinyl compound in the polymer block C is not particularly limited, and can be, for example, random, tapered, partially blocky, or any combination thereof. Among these, a random shape is preferable.

[0029] In the polymer block C, the proportion of the structural unit derived from the conjugated diene compound is preferably more than 30% by mass, more preferably 50% by mass or more, and still more preferably 60% by mass or more, based on all the structural units constituting the polymer block C. Also, the proportion of the structural unit derived from the conjugated diene compound is preferably 90% by mass or less, more preferably 85% by mass or less, based on all the structural units constituting the polymer block C.

[0030] In addition, in the polymer block C, the proportion of the structural unit derived from the aromatic vinyl compound is preferably 10% by mass or more, more preferably 15% by mass or more, based on all the structural units constituting the polymer block C. Also, the proportion of the structural unit derived from the aromatic vinyl compound is preferably less than 50% by mass, more preferably 40% by mass or less, based on all the structural units constituting the polymer block C.

[0031] With respect to all the structural units constituting the polymer (A1), the proportion of the structural units derived from the conjugated diene compound is preferably more than 50% by mass, more preferably 60% by mass or more, and still more preferably 70% by mass or more. Further, the proportion of the structural units derived from the conjugated diene compound is preferably 98% by mass or less, more preferably 95% by mass or less, with respect to all the structural units constituting the polymer (A1). It is preferable in that a block copolymer exhibiting good adhesion performance can be obtained when the proportion of the structural units derived from the conjugated diene compound in the polymer (A1) is within the above range.

[0032] Further, in the polymer (A1), the proportion of the structural units derived from the aromatic vinyl compound is preferably 2% by mass or more, more preferably 5% by mass or more, with respect to all the structural units constituting the polymer (A1). Further, the proportion of the structural units derived from the aromatic vinyl compound is preferably less than 50% by mass, more preferably 40% by mass or less, and still more preferably 30% by mass or less, with respect to all the structural units constituting the polymer (A1). When the proportion of the structural units derived from the aromatic vinyl compound in the polymer (A1) is within the above range, it is preferable in that the polymer (A1) can be prevented from becoming too hard and a block copolymer exhibiting good adhesion performance and developability can be obtained.

[0033] The proportion of the structural units derived from the aromatic vinyl compound constituting the polymer block B with respect to the total amount of the structural units derived from the aromatic vinyl compound possessed by the polymer (A1) is preferably more than 50% by mass, more preferably 60% by mass or more, and still more preferably 70% by mass or more. It is preferable in that a polymer having high adhesive strength to a polar resin substrate can be obtained when the proportion of the structural units derived from the aromatic vinyl compound constituting the polymer block B is within the above range with respect to the total amount of the structural units derived from the aromatic vinyl compound possessed by the polymer (A1).

[0034] The proportion of polymer block B relative to the total amount (100% by mass) of polymer block A and polymer block B is preferably 2% by mass or more, more preferably 5% by mass or more, and still more preferably 8% by mass or more. Also, the proportion of polymer block B is preferably less than 50% by mass, more preferably 40% by mass or less, and still more preferably 35% by mass or less, relative to the total amount of polymer block A and polymer block B. When the proportion of polymer block B is 2% by mass or more, the glass transition temperature (Tg) of polymer (A1) can be moderately increased, and low tack creep and developability can be improved in a well-balanced manner. Also, when the proportion of polymer block B is less than 50% by mass, it is preferable in terms of sufficiently ensuring the adhesion performance and mechanical properties of polymer (A1).

[0035] In addition, when polymer (A1) has a plurality of polymer blocks A or polymer blocks B in one molecule, the proportion of polymer block B relative to the total amount of polymer block A and polymer block B represents the proportion occupied by polymer block B (or the total amount when there are a plurality of polymer blocks B) relative to the total amount of all polymer blocks A and polymer blocks B that polymer (A1) has. The proportion of polymer block B relative to the total amount of polymer block A and polymer block B can be calculated based on the charged amount of monomers during polymerization.

[0036] <Production of Block Copolymer> [A] The method for producing the block copolymer is not particularly limited. As the polymerization method to be used, any of solution polymerization method, gas phase polymerization method, bulk polymerization method, etc. may be used, but the solution polymerization method is particularly preferred. Also, as the polymerization mode, either batchwise or continuous mode may be used. When the solution polymerization method is used, as an example of a specific polymerization method, in an organic solvent, monomers are polymerized in the presence of a polymerization initiator and, if necessary, a vinyl content adjuster (randomizer) to obtain a polymer chain P having polymer block A and polymer block B 1It is produced (polymerization step), then a coupling agent is added to carry out a coupling reaction (coupling step), and thereafter, a hydrogenation reaction is carried out (hydrogenation step).

[0037] (Polymerization step) As the polymerization initiator, a metal compound having an alkali metal or an alkaline earth metal can be used. Among these, a compound having an alkali metal is preferably used. Specific examples of the metal compound include alkyllithiums such as methyllithium, ethyllithium, n-propyllithium, n-butyllithium, sec-butyllithium, t-butyllithium; 1,4-dilithiobutane, phenyllithium, stilbenelithium, naphthyllithium, 1,3-bis(1-lithio-1,3-dimethylpentyl)benzene, 1,3-phenylenebis(3-methyl-1-phenylpentylidene)dilithium, naphthylsodium, naphthylpotassium, ethoxypotassium, etc. Among these, lithium compounds are preferred.

[0038] Also, the metal compound used as the polymerization initiator may be a metal amide compound having an alkali metal or an alkaline earth metal. [A] By carrying out the polymerization for obtaining a block copolymer in the presence of a metal amide compound, an amino group can be introduced into the polymerization initiation terminal of the block copolymer (more specifically, the free terminal portion of the branched polymer). Further, the [A] block copolymer obtained by polymerization in the presence of a metal amide compound is suitable in that it exhibits excellent adhesiveness.

[0039] Among metal amide compounds, a compound obtained by mixing a lithium compound (for example, an alkyl lithium, etc.) and a compound having a nitrogen atom (hereinafter also referred to as an “initiating end modifier”) is preferably used. The initiating end modifier is preferably a secondary amine compound, and specific examples thereof include dimethylamine, diethylamine, dipropylamine, dibutylamine, dodecamethyleneimine, N,N'-dimethyl-N'-trimethylsilyl-1,6-diaminohexane, piperidine, pyrrolidine, hexamethyleneimine, heptamethyleneimine, dicyclohexylamine, N-methylbenzylamine, di-(2-ethylhexyl)amine, diallylamine, morpholine, N-(trimethylsilyl)piperazine, N-(tert-butyldimethylsilyl)-4-piperazine, 1,3-ditrimethylsilyl-1,3,5-triazinane, etc. Among these, a compound having a group in which at least one of a primary amino group and a secondary amino group is protected with a silyl compound or the like can be preferably used for the purpose of improving the reactivity with a post-modifier (such as maleic anhydride) or a cross-linking agent (such as a polyfunctional epoxy compound).

[0040] When polymerization is carried out in the presence of a metal amide compound, the metal amide compound may be prepared by previously mixing a lithium compound and an initiating end modifier, and the prepared metal amide compound may be added to the polymerization system to carry out the polymerization. Alternatively, a lithium compound and an initiating end modifier may be added to the polymerization system, and the metal amide compound may be prepared by mixing the two in the polymerization system to carry out the polymerization. The amount of the polymerization initiator used (the total amount when two or more kinds are used) is preferably 0.01 to 20 mmol, more preferably 0.05 to 15 mmol, per 100 g of the monomer used for the synthesis of the polymer.

[0041] The vinyl content regulator is used for the purpose of adjusting the vinyl bond content in the polymer, etc. Examples of the vinyl content regulator include dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, 2,2-di(tetrahydrofuryl)propane, 2-(2-ethoxyethoxy)-2-methylpropane, triethylamine, pyridine, N-methylmorpholine, and tetramethylethylenediamine, etc. As the vinyl content regulator, one kind can be used alone or two or more kinds can be used in combination.

[0042] As the organic solvent used for polymerization, an organic solvent inert to the reaction may be used. For example, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, etc. can be used. Among these, hydrocarbons having 3 to 8 carbon atoms are preferred. Specific examples thereof include propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propene, 1-butene, isobutene, trans-2-butene, cis-2-butene, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene, heptane, cyclopentane, methylcyclopentane, methylcyclohexane, 1-pentene, 2-pentene, cyclohexene, etc. Note that as the organic solvent, one kind can be used alone or two or more kinds can be used in combination.

[0043] When carrying out solution polymerization, from the viewpoint of maintaining the balance between productivity and ease of polymerization control, the monomer concentration in the reaction solvent is preferably 5 to 50% by mass, and more preferably 10 to 30% by mass. The temperature of the polymerization reaction is preferably -30°C to 150°C. The polymerization may be carried out while controlling the temperature to be constant, or may be carried out under heating without heat removal. Also, the polymerization reaction is preferably carried out under a pressure sufficient to keep the monomer substantially in the liquid phase. Such pressure can be obtained by a method such as pressurizing the inside of the reactor with a gas inert to the polymerization reaction.

[0044] The method of making the reaction product (more specifically, a chain polymer) by the above polymerization reaction into a block copolymer can be any method. When producing a block copolymer having a polymer block A and a polymer block B, from the perspective of productivity, first, a monomer is polymerized in the presence of a polymerization initiator to produce one segment (hereinafter also referred to as the "first segment") of either the polymer block A or the polymer block B. Next, the other segment (hereinafter also referred to as the "second segment") is produced by polymerizing the monomer in the presence of the first segment. At this time, by using a metal amide compound as the polymerization initiator, a block copolymer in which a functional group F is introduced at the polymerization initiation terminal of the first segment can be obtained. After the polymerization of the second segment, if necessary, a polymer composed of a first segment - second segment - third segment can be produced by further adding a monomer and performing polymerization. The third segment may be either the polymer block A or the polymer block B, or may be a polymer block C.

[0045] Among them, the chain polymer (i.e., polymer chain P 1 ) obtained by this step preferably has the first segment as the polymer block A and the second segment as the polymer block B. In this case, the effect of improving the adhesion performance (especially, adhesion strength and tackiness) of the [A] block copolymer can be enhanced. In terms of being able to further enhance the effect of improving the adhesion performance, the polymer chain P 1 is preferably a triblock composed of polymer block A - polymer block B - polymer block A or polymer block A - polymer block B - polymer block C. The boundaries of each polymer block do not necessarily have to be clearly distinguishable. Hereinafter, for convenience, the second polymer block A as viewed from the polymerization initiation terminal may be denoted as "polymer block A'".

[0046] (Coupling step) Next, the block copolymer obtained by the above polymerization step (i.e., the polymer chain P constituting the polymer (A1) 1) and react it with a coupling agent. The coupling agent used for the production of the polymer (A1) is not particularly limited, and known coupling agents in the production of polymers can be arbitrarily used. The coupling agent is preferably a polyfunctional coupling agent having four or more reaction points with the active terminals of the block copolymer obtained by the above polymerization step.

[0047] Specific examples of the coupling agent include, for example, tetrachlorosilane, tetramethoxysilane, tetrachlorogermane, tetrachlorotin, bis(trichlorosilyl)ethane and the like.

[0048] Further, as the coupling agent, a compound having a functional group F containing at least one element selected from the group consisting of nitrogen, silicon, oxygen and sulfur and having four or more reaction sites with the polymer chain obtained by the above polymerization step (hereinafter, also referred to as "terminal modifier") can also be used. Specific examples of the functional group F of the terminal modifier include the same groups as the specific examples of the functional group F described in the above polymerization step.

[0049] Specific examples of such terminal modifiers include, for example, nitrogen-containing alkoxysilane compounds described in JP-A-2014-177519, JP-A-2016-079217, and WO 2017 / 221943; glycidyl group-containing polysiloxanes described in WO 2017 / 090421 and the like. Among these, a polyfunctional coupling agent having a nitrogen-containing functional group can be preferably used. When a nitrogen-containing polyfunctional coupling agent is used, it is suitable in that a block copolymer with further balanced improvement in high adhesiveness and suppression of increase in tackiness can be produced.

[0050] The reaction between the block copolymer obtained by the above polymerization step and the coupling agent is preferably carried out as a solution reaction. The usage ratio of the coupling agent (the total amount when two or more kinds are used) is preferably 0.01 mol or more, more preferably 0.05 mol or more, per 1 mol of the metal atom involved in the polymerization of the polymerization initiator, from the viewpoint of sufficiently increasing the adhesiveness and developability. Also, the usage ratio of the coupling agent is preferably less than 2.0 mol, more preferably less than 1.5 mol, per 1 mol of the metal atom involved in the polymerization of the polymerization initiator, from the viewpoint of suppressing the decrease in moldability and maintaining sufficiently high adhesive strength. Note that, as the coupling agent, one kind may be used alone, or two or more kinds may be used in combination.

[0051] The temperature of the above reaction is usually the same as that of the polymerization reaction, and is preferably -30°C to 150°C. When the reaction temperature is low, the viscosity of the polymer after coupling tends to increase easily, and when the reaction temperature is high, the polymerization terminal tends to be deactivated easily. The reaction time is preferably 1 minute to 5 hours, more preferably 2 minutes to 1 hour.

[0052] In the coupling reaction for obtaining the [A] block copolymer, the coupling rate is preferably 30% or more, more preferably 35% or more, still more preferably 50% or more, and even more preferably 65% or more, from the viewpoints of improving the adhesiveness of the [A] block copolymer, suppressing the enhancement of adhesiveness, and developability, and efficiently forming a network structure when reacting with a crosslinking agent. Also, the coupling rate is preferably 98% or less, more preferably 95% or less, from the viewpoint of obtaining a polymer with high fluidity and good moldability. Note that in this specification, the "coupling rate" means the ratio of the polymer bonded via the coupling agent among the polymers used in the reaction with the coupling agent (that is, the polymer chains P 1 ) that constitute the present polymer. The coupling rate can be calculated from the peak area ratio of the GPC curve obtained using gel permeation chromatography (GPC).

[0053] (Hydrogenation Step) In this step, the block copolymer obtained in the above coupling step is hydrogenated. The method and conditions of the hydrogenation reaction can be any method and conditions as long as a block copolymer with a desired hydrogenation rate can be obtained. Specific examples of the hydrogenation method include a method using a catalyst mainly composed of an organometallic compound of titanium as a hydrogenation catalyst, a method using a catalyst composed of an organic compound of iron, nickel, or cobalt and an organometallic compound such as alkylaluminum, a method using an organic complex of an organometallic compound such as ruthenium or rhodium, and a method using a catalyst in which a metal such as palladium, platinum, ruthenium, cobalt, or nickel is supported on a carrier such as carbon, silica, or alumina. Among various methods, a method of hydrogenating under mild conditions of low pressure and low temperature using a homogeneous catalyst composed of an organometallic compound of titanium alone or an organometallic compound of titanium and an organometallic compound of lithium, magnesium, or aluminum (see, for example, Japanese Patent Publication No. 63-4841 and Japanese Patent Publication No. 1-37970) is industrially preferable and also has high hydrogenation selectivity for the double bond of butadiene and is suitable.

[0054] The hydrogenation of the block copolymer is preferably carried out using a solvent that is inert to the catalyst and soluble in the block copolymer. Preferred solvents include aliphatic hydrocarbons (e.g., n-pentane, n-hexane, n-octane), alicyclic hydrocarbons (e.g., cyclohexane, cycloheptane), aromatic hydrocarbons (e.g., benzene, toluene), ethers (e.g., diethyl ether, tetrahydrofuran), either alone or as a mixture having these as the main components.

[0055] The hydrogenation reaction is generally carried out by maintaining a block polymer at a predetermined temperature under hydrogen or an inert atmosphere, adding a hydrogenation catalyst with stirring or without stirring, and then introducing hydrogen gas to pressurize it to a predetermined pressure. The inert atmosphere means an atmosphere that does not react with the participants in the hydrogenation reaction, and examples include helium, neon, argon, etc. Air and oxygen may oxidize the catalyst and cause deactivation of the catalyst. Also, nitrogen may act as a catalyst poison during the hydrogenation reaction and may reduce the hydrogenation activity. Therefore, it is preferable that the inside of the hydrogenation reactor is an atmosphere of hydrogen gas alone.

[0056] The hydrogenation reaction process for obtaining a hydrogenated block copolymer can be used in any of a batch process, a continuous process, or a combination thereof. When using a titanocene diaryl-based compound as the hydrogenation catalyst, it may be added directly to the reaction solution as it is, or added as a solution in an inert organic solvent. The addition amount of the catalyst is, for example, 0.02 to 20 mmol per 100 g of the block polymer before hydrogenation.

[0057] [A] The hydrogenation rate of the block copolymer is 75% or more. When the hydrogenation rate of the [A] block copolymer is less than 75%, gelation tends to occur, resulting in a decrease in moldability or a tendency for adhesive residue to occur during peeling from the adherend. From the viewpoint of improving moldability and reducing adhesive residue, the hydrogenation rate of the [A] block copolymer is preferably 80% or more, more preferably 83% or more, still more preferably 85% or more, even more preferably 90% or more, and particularly preferably 95% or more. Also, the hydrogenation rate of the [A] block copolymer is, for example, 99% or less.

[0058] Note that the value α represented by the above formula (i) corresponds to the hydrogenation rate of the polymer. For example, when α = 0.75, the hydrogenation rate of the polymer is 75%. The hydrogenation rate of the polymer and α can be adjusted, for example, by adjusting the time of the hydrogenation reaction or controlling the integrated amount of hydrogen supplied. In this specification, the hydrogenation rate is 1 a value measured by an H-NMR apparatus.

[0059] After hydrogenation, the catalyst residue is removed as necessary, or a phenolic or amine-based antioxidant is added. Then, the hydrogenated conjugated diene polymer (i.e., the [A] block copolymer) is isolated from the polymer solution. The isolation of the polymer can be carried out, for example, by adding acetone, alcohol, or the like to the polymer solution to cause precipitation, or by charging the polymer solution into hot water with stirring and distilling off the solvent.

[0060] (Post-modification step) Regarding the block copolymer after the hydrogenation reaction, it may be used as it is for the desired application, but the block copolymer after the hydrogenation reaction may be further subjected to a modification treatment (post-modification step). Such a modification treatment is preferable in that it can further improve the suppression of the increase in tackiness and the developability of the present polymer. In particular, in the case of a polymer in which a primary amine or a secondary amine is introduced at the terminal by the modification treatment, the modification rate of the modifier (hereinafter also referred to as the "post-modifier") in the post-modification step is improved, and the generation of residues of the post-modifier can be suppressed. For this reason, it is preferable in that it can suppress the contamination of the adherend due to re-peeling and the diffusion of the contamination components to the adherend due to permanent adhesion.

[0061] For the [A] block copolymer, the weight average molecular weight (Mw) in terms of polystyrene measured using gel permeation chromatography (GPC) is preferably 5.0×10 4 ~7.0×10 5 When Mw is 5.0×10 4 or more, it has excellent mechanical properties, and when peeling from the adherend, there is little glue residue, the holding force is high, and the displacement between the adherend and the adhesive can be reduced. Also, when Mw is 7.0×10 5 or less, the fluidity of the [A] block copolymer can be sufficiently ensured, and the molding processability can be improved. The Mw of the [A] block copolymer is more preferably 7.0×10 4 or more, and still more preferably 1.0×10 5 or more. Also, the Mw of the [A] block copolymer is more preferably 6.5×10 5It is as follows. The weight average molecular weight (Mw) of the [A] block copolymer referred to herein is a value obtained from all peaks of the GPC curve measured by GPC before hydrogenation. Hereinafter, it is also referred to as the "total weight average molecular weight".

[0062] Also, for the [A] block copolymer, the peak top molecular weight of the peak with the smallest molecular weight measured by GPC (hereinafter, also referred to as the "1st peak weight average molecular weight") is preferably 1.2×10 4 ~2.2×10 5 . When the 1st peak weight average molecular weight is within the above range, it is suitable in that an adhesive with a good balance between adhesive strength and moldability can be obtained, and in that tackiness is good and residue after pasting is less likely to occur. The 1st peak weight average molecular weight of the [A] block copolymer is more preferably 2.0×10 4 or more, and even more preferably 3.0×10 4 or more. Also, in terms of making the moldability more excellent, the 1st peak weight average molecular weight is more preferably 2.0×10 5 or less, and even more preferably 1.9×10 5 or less. The 1st peak weight average molecular weight is a value obtained from the GPC curve measured by GPC before hydrogenation.

[0063] For the [A] block copolymer, the melt flow rate (MFR) measured at 230°C under a load of 21.2 N is preferably 0.1 to 100 g / 10 min. In the manufacturing process of the pressure-sensitive adhesive film, when coextrusion molding the resin constituting the base material layer and the [A] block copolymer constituting the pressure-sensitive adhesive layer, the moldability can be improved by setting the MFR within the above range. The MFR of the [A] block copolymer is more preferably 0.3 g / 10 min or more, and even more preferably 0.5 g / 10 min or more. Also, the MFR of the [A] block copolymer is more preferably 50 g / 10 min or less, and even more preferably 30 g / 10 min or less.

[0064] The [A] block copolymer obtained by the above process contains a polymer (A1) having a multi-branched structure with four or more polymer chains. Typically, the polymer (A1) has a structure in which four or more polymer chains are bonded to a partial structure derived from a coupling agent. In terms of being able to improve various properties such as adhesion performance (adhesion strength, tackiness, low adhesion creep property), moldability, spreadability, and resistance to residual paste in a well-balanced manner, it is preferable for the coupling agent to have a functional group containing nitrogen.

[0065] The [A] block copolymer preferably contains a linear polymer (A2) together with the polymer (A1). More specifically, the polymer (A2) is a polymer obtained by the above polymerization process and is a hydrogenated product of an unreacted polymer that was not subjected to reaction with a coupling agent among the block copolymers before coupling. In terms of being able to increase the adhesion strength while reducing the spreading force, it is preferable for the polymer (A2) to have a primary amino group, a secondary amino group, or a tertiary amino group at one terminal portion. Such a terminally modified chain polymer can be obtained by using a metal amide compound as a polymerization initiator in the above polymerization process.

[0066] When the amount of the [A] block copolymer is 100% by mass, the proportion of the polymer (A1) in the [A] block copolymer is 10% by mass or more. When the proportion of the polymer (A1) with respect to the [A] block copolymer is less than 10% by mass, the adhesion strength and low adhesion creep property are insufficient, and the adhesion performance is poor. Also, there is a tendency for the spreadability to deteriorate and for residual paste to easily occur when peeled from the adherend. Further, when used in combination with a crosslinking agent, it is difficult to efficiently form a network, and there is a tendency that sufficient heat resistance and solvent resistance cannot be ensured. The proportion of the polymer (A1) in the [A] block copolymer is preferably 20% by mass or more, more preferably 35% by mass or more, still more preferably 50% by mass or more, and even more preferably 60% by mass or more. Also, the proportion of the polymer (A1) in the [A] block copolymer is preferably 90% by mass or less, and more preferably 80% by mass or less. When the proportion of the polymer (A1) in the [A] block copolymer is 90% by mass or less, it is suitable in terms of being able to increase the tackiness.

[0067] In addition, the content ratio of polymer (A1) in the [A] block copolymer can be calculated by separating the waveform of the coupling polymer in the measurement chart by gel permeation chromatography (GPC).

[0068] Also, the ratio of polymer (A1) to the total amount (100% by mass) of polymer (A1) and polymer (A2) in the [A] block copolymer is preferably 10% by mass or more, preferably 20% by mass or more, more preferably 35% by mass or more, still more preferably 50% by mass or more, and even more preferably 60% by mass or more. Further, the ratio of polymer (A1) is preferably 90% by mass or less, more preferably 80% by mass or less, based on the total amount of polymer (A1) and polymer (A2).

[0069] <<Adhesive and Adhesive Film>> Since the [A] block copolymer has excellent adhesion performance, it is suitable for use as an adhesive. The adhesive obtained by using the [A] block copolymer (hereinafter also referred to as "the present adhesive") may be composed only of the [A] block copolymer, or may further contain components different from the [A] block copolymer (hereinafter also referred to as "other components"). Examples of other components include tackifiers. By blending a tackifier into the present adhesive, the initial adhesiveness of the adhesive can be improved.

[0070] As the tackifier, for example, petroleum resins (such as aliphatic copolymers, aromatic copolymers, aliphatic-aromatic copolymers, alicyclic copolymers, etc.), coumarone-indene resins, terpene resins, terpene phenol resins, rosin resins, (alkyl)phenol resins, xylene resins, or hydrogenated products thereof, etc., which are generally used in adhesive applications, can be used. As the tackifier, only one kind may be used, or two or more kinds may be used in combination.

[0071] In addition, as other components, in addition to the above, for example, polyolefin resins, antioxidants, ultraviolet absorbers, colorants, light stabilizers, heat polymerization inhibitors, defoamers, leveling agents, antistatic agents, surfactants, storage stabilizers, anti-aging agents, flame retardants, various fillers and the like can be mentioned. In this adhesive, the blending ratio of other components can be appropriately set according to each component within the range that does not impair the effects of the present disclosure.

[0072] Further, a composition containing a hydrogenated block polymer and a crosslinking agent may be reacted while applying shear deformation, thereby crosslinking the hydrogenated block polymer. By forming a crosslinked structure in the hydrogenated block copolymer, further improvement in solvent resistance and mechanical strength can be achieved. As the crosslinking agent, a compound having two or more functional groups capable of reacting with the functional group F can be preferably used. Examples of such crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, melamine-based crosslinking agents, aldehyde-based crosslinking agents, amine-based crosslinking agents, chelate-based crosslinking agents, carbodiimide-based crosslinking agents, in addition to hydroxyl group-containing compounds, acid compounds, acid anhydrides, radical generators and the like.

[0073] Examples of the isocyanate-based crosslinking agent include aromatic isocyanate-based crosslinking agents such as tolylene diisocyanate-based crosslinking agents like 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, xylylene diisocyanate-based crosslinking agents like 1,3-xylylene diisocyanate, diphenylmethane-based crosslinking agents like diphenylmethane-4,4-diisocyanate, and naphthalene diisocyanate-based crosslinking agents like 1,5-naphthalene diisocyanate; alicyclic isocyanate-based crosslinking agents such as isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, isopropylidene dicyclohexyl-4,4'-diisocyanate, 1,3-diisocyanatomethylcyclohexane, and norbornane diisocyanate; aliphatic isocyanate-based crosslinking agents such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; and adducts, burettes, isocyanurates, etc. of the above isocyanate-based compounds.

[0074] Examples of the epoxy-based crosslinking agent include bisphenol A·epichlorohydrin type epoxy resins, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, and diglycerol polyglycidyl ether.

[0075] Examples of the aziridine-based crosslinking agent include tetramethylolmethane-tri-β-aziridinylpropionate, trimethylolpropane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), and N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide).

[0076] Examples of the melamine-based crosslinking agent include hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, hexaptoxymethylmelamine, hexapentyloxymethylmelamine, hexahexyloxymethylmelamine, melamine resins, and the like.

[0077] Examples of the aldehyde crosslinking agent include glyoxal, malondialdehyde, succindialdehyde, maleic dialdehyde, glutaric dialdehyde, formaldehyde, acetaldehyde, and benzaldehyde.

[0078] Examples of the amine-based crosslinking agent include hexamethylenediamine, triethyldiamine, polyethyleneimine, hexamethylenetetraamine, diethylenetriamine, triethyltetraamine, isophoronediamine, amino resins, and polyamides.

[0079] Examples of the metal chelate crosslinking agent include acetylacetone and acetoacetyl ester coordination compounds of polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium.

[0080] Examples of the carbodiimide crosslinking agent include polyfunctional carbodiimide compounds and polymeric carbodiimide compounds.

[0081] Examples of the hydroxyl group-containing compound include polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, and polyisoprene polyols.

[0082] Examples of the polyfunctional crosslinking agent containing a carboxy group include aromatic dicarboxylic acids such as σ-phthalic acid, isophthalic acid, terephthalic acid, 1,4-dimethylterephthalic acid, 1,3-dimethylisophthalic acid, 5-sulfo-1,3-dimethylisophthalic acid, 4,4-biphenyldicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, norbornenedicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid or phenylindanedicarboxylic acid; aromatic dicarboxylic anhydrides such as phthalic anhydride, 1,8-naphthalenedicarboxylic anhydride or 2,3-naphthalenedicarboxylic anhydride; alicyclic dicarboxylic acids such as hexahydrophthalic acid; alicyclic dicarboxylic anhydrides such as hexahydrophthalic anhydride, 3-methyl-hexahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride or 1,2-cyclohexanedicarboxylic anhydride; aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, suberic acid, maleic acid, chloromaleic acid, fumaric acid, dodecanedioic acid, pimelic acid, citraconic acid, glutaric acid or itaconic acid, and the like.

[0083] Examples of the acid anhydride include pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, oxydiphthalic dianhydride, diphenylsulfone tetracarboxylic dianhydride, diphenylsulfide tetracarboxylic dianhydride, butanetetracarboxylic dianhydride, perylene tetracarboxylic dianhydride or naphthalene tetracarboxylic dianhydride, and the like.

[0084] The above radical generator is used to generate radicals by irradiating ultraviolet rays such as heat or ultraviolet rays when producing an adhesive layer that constitutes a part of the adhesive film. Radicals can be generated to crosslink the present polymer. As the radical generator, a photo radical generator that generates radicals by irradiating light such as ultraviolet rays is preferable. Specific examples of the photo radical generator include hydroxyketones, benzyldimethylketals, aminoketones, acylphosphine oxides, benzophenones, and the like. These photo radical generators can be used alone or in combination of two or more.

[0085] The radical generator may be an oligomer-type photo radical generator. The oligomer-type photo radical generator is a low molecular weight polymer of a monomer having a functional group capable of generating radicals by irradiating light such as ultraviolet rays. Such an oligomer-type photo radical generator has a plurality of radical generation points in one molecule, so it is less affected by crosslinking inhibition by oxygen, can be crosslinked with a small amount, and does not scatter even in a solvent-free hot melt state when applied to a substrate, and is preferably used in that it is not extracted from the polymer.

[0086] Specific examples of the oligomer-type photo radical generator include an oligomer obtained by polymerizing acrylated benzophenone (manufactured by UCB, trade name "Ebecryl P36"), an oligomer obtained by polymerizing a reaction product of the primary hydroxyl group of 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one (manufactured by BASF, trade name "Irgacure 2959") and 2-isocyanatoethyl methacrylate, and 2-hydroxy-2-methyl-[4-(1-methylvinyl)phenyl]propanol oligomer (manufactured by Lamberti, trade name "Esacure KIP150"). The molecular weight of these oligomer-type photo radical generators is preferably about 50,000 or less.

[0087] In addition, as the crosslinking agent, one kind may be used alone, or two or more kinds may be used in combination. The amount of the crosslinking agent used can be appropriately determined according to the performance required for the target final composition. The amount of the crosslinking agent used is usually 0.1 to 20 parts by mass, preferably 0.2 to 10 parts by mass, based on 100 parts by mass of the present polymer. The reaction between the present polymer and the crosslinking agent may be carried out in the presence of a curing catalyst as necessary.

[0088] This adhesive can be used for various applications. Specifically, it can be used as various adhesive films such as adhesive tapes, adhesive labels, adhesive sheets, assemblies, building material protection films, resin plate protection films, automobile protection films, protection films for optical members (for example, for various displays such as liquid crystal displays, for light guide plates), and interlayer films for laminated glass. In particular, this adhesive is suitable for use as an optical surface protection film (for example, a surface protection film for an optical film).

[0089] Since the present polymer is excellent in various properties such as initial adhesiveness, low adhesive creep property, developability, adhesive residue suppression property, and solvent resistance, it can be used for various applications. Specifically, it can be used as the adhesive layer of a surface protection film, the adhesive layer of an adhesive film for a structure, a modifier for a resin composition, and also as a molded article. Furthermore, the present polymer is excellent in vibration damping property and can be used for various applications such as vibration damping materials, vibration damping films, and vibration damping sheets.

[0090] Further, according to the present disclosure, there is also provided a laminate having an X layer containing the present polymer and a Y layer laminated on at least one surface of the X layer. As such a laminate, for example, laminated glass is suitable. Specifically, by using the above X layer as an interlayer film for laminated glass and the above Y layer as a glass layer and laminating them to form laminated glass, not only excellent vibration damping properties but also excellent sound insulation properties can be expected. Further, as the Y layer, in addition to the glass layer, it can be appropriately selected according to various applications. For example, a laminate having a layer containing a thermoplastic resin other than the present polymer as the Y layer can be mentioned. Examples of such thermoplastic resins include polyvinyl acetal resins, ionomers, ethylene-vinyl acetate copolymers, urethane resins, polyamide resins, and the like.

[0091] Other uses of the present polymer include, for example, the following uses. (1) Pellets, veils, sound absorbing materials, sound insulation materials, dam rubbers, shoe sole materials, floor materials, weather strips, floor mats, dash insulators, roof linings, door panels, engine head covers, door hole seals, fender liners, etc. (2) Various products in the automotive field: For example, cooling parts such as thermostat housings, radiator tanks, radiator hoses, water outlets, water pump housings, rear joints, etc.; intake and exhaust system parts such as intercooler tanks, intercooler cases, turbo duct pipes, EGR cooler cases, resonators, throttle bodies, intake manifolds, tail pipes, etc.; fuel system parts such as fuel delivery pipes, gasoline tanks, quick connectors, canisters, pump modules, fuel pipes, oil strainers, lock nuts, sealing materials, etc.; structural parts such as mount brackets, torque rods, cylinder head covers, etc.; drive system parts such as bearing retainers, gear tensioners, headlamp actuator gears, HVAC gears, slide door rollers, clutch peripheral parts, etc.; brake system parts such as air brake tubes, etc.; in-vehicle electrical parts such as wire harness connectors, motor parts, sensors, ABS bobbins, combination switches, in-vehicle switches, electronic control unit (ECU) boxes, etc. inside the engine room; interior and exterior parts such as slide door dampers, door mirror stays, door mirror brackets, inner mirror stays, roof rails, engine mount brackets, air cleaner inlet pipes, door checkers, plastic chains, emblems, clips, breaker covers, cup holders, airbags, fenders, spoilers, radiator supports, radiator grills, louvers, air scoops, hood bulges, back doors, fuel sender modules, floor mats, instrument panels, dashboards, dash insulators, dam rubbers, weather strips, etc., and tires, etc.

[0092] (3) Various products in the household appliance field: For example, various electrical products such as televisions, various recorders such as Blu-ray recorders and HDD recorders, projectors, game consoles, digital cameras, home videos, antennas, speakers, electronic dictionaries, IC recorders, FAX machines, copiers, telephones, door phones, rice cookers, microwave ovens, oven ranges, refrigerators, dishwashers, dish dryers, IH cooking heaters, hot plates, vacuum cleaners, washing machines, chargers, sewing machines, irons, dryers, electric bicycles, air cleaners, water purifiers, electric toothbrushes, lighting fixtures, air conditioners, outdoor units of air conditioners, dehumidifiers, humidifiers, etc. Sealing materials, adhesives, pressure-sensitive adhesives, packings, O-rings, belts, soundproofing materials, etc.

[0093] In addition, this polymer can also be used as a modifier for improving properties such as the toughness and impact resistance of thermoplastic resins. Examples of the thermoplastic resin in which this polymer is blended as a modifier include polypropylene, polyethylene, polystyrene, polycarbonate, polyester, polyarylene, polyarylene ether, polyarylene sulfide, polyamide, polyimide, ABS resin, etc.

Examples

[0094] Hereinafter, specific explanations will be given based on examples, but the present invention is not limited to these examples. Note that "parts" and "%" in the examples and comparative examples are based on mass unless otherwise specified.

[0095] 1. Physical property measurement method The measurement methods for various physical property values of the polymer are as follows. [Vinyl bond content (mol%)]: Measured using a polymer before hydrogenation with a 500 MHz apparatus 1 Calculated from the H-NMR spectrum. [1st peak weight average molecular weight]: Determined in terms of polystyrene from the retention time of the peak with the longest retention time in the GPC curve obtained using gel permeation chromatography (GPC) (HLC-8120GPC (product name, manufactured by Tosoh Corporation)). (GPC conditions) Columns; two columns of product name "GMHXL" (manufactured by Tosoh Corporation) Column temperature; 40 °C Mobile phase; tetrahydrofuran Flow rate; 1.0 ml / min Sample concentration; 10 mg / 20 ml [Total weight average molecular weight]: Determined in terms of polystyrene from the GPC curve obtained using GPC (HLC-8120GPC (product name (manufactured by Tosoh Corporation))). [Coupling rate]: Calculated from the peak area ratio of the GPC curve obtained using GPC (HLC-8120GPC (product name (manufactured by Tosoh Corporation))). [Hydrogenation rate]: Measured with a 100 MHz apparatus using ethylene tetrachloride as a solvent 1 Calculated from the 1H-NMR spectrum. [Melt flow rate (MFR)]: Measured at 230 °C under a load of 21.2 N in accordance with JIS K7210.

[0096] 2. Production of block copolymer [Example 1]: Production of polymer (A-1) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.11 part of piperidine, and 0.11 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel. 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, and temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, and temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.05 part of tetrachlorosilane was added, and further temperature-rising polymerization was carried out. The polymer thus obtained contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 70 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene and having a vinyl bond content of 70 mol%, and was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 110,000, the total weight average molecular weight was 340,000, and the coupling rate was 75%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogen addition reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C and normal pressure, and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, stirred and poured into water, and the solvent was removed by steam distillation. Drying was carried out using a hot roll adjusted to 110°C to obtain a polymer (A-1) with a hydrogenation rate of the conjugated diene portion of 98% and an MFR of 3.0 g / 10 min. Various physical property values, etc. of the obtained polymer (A-1) are shown in Table 1.

[0097] [Example 2]: Production of Polymer (A-2) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.15 part of piperidine, and 0.16 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel, and 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.08 part of tetrachlorosilane was added, and further temperature-rising polymerization was carried out. The polymer thus obtained contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 71 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene with a vinyl bond content of 72 mol%, and was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 80,000, the total weight average molecular weight was 260,000, and the coupling rate was 70%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C at normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, and it was stirred and poured into water to remove the solvent by steam distillation, and dried by a hot roll adjusted to 110°C, whereby a polymer (A-2) with a hydrogenation rate of the conjugated diene portion of 98% and an MFR of 16.2 g / 10 min was obtained. Various physical property values of the obtained polymer (A-2) are shown in Table 1.

[0098] [Example 3] Production of Polymer (A-3) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.11 part of piperidine, and 0.11 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel, and 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.07 part of tetrachlorosilane was added, and further temperature-rising polymerization was carried out. The polymer thus obtained contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 73 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene and having a vinyl bond content of 71 mol%, and was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 110,000, the total weight average molecular weight was 380,000, and the coupling rate was 95%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C and normal pressure, and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, stirred and poured into water, and the solvent was removed by steam distillation, and drying was carried out using a hot roll adjusted to 110°C to obtain a polymer (A-3) with a hydrogenation rate of the conjugated diene portion of 98% and an MFR of 1.3 g / 10 min. Various physical property values of the obtained polymer (A-3) are shown in Table 1.

[0099] [Example 4]: Production of Polymer (A-4) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.08 part of piperidine, and 0.08 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel, and 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, followed by temperature-raising polymerization. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, followed by temperature-raising polymerization. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-raising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.03 part of tetrachlorosilane was added, and further temperature-raising polymerization was carried out. The polymer thus obtained contained a structural unit derived from 1,3-butadiene, a polymer block A having a vinyl bond content of 70 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene and having a vinyl bond content of 72 mol%. It was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 160,000, the total weight average molecular weight was 460,000, and the coupling rate was 73%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C under normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, and it was stirred and poured into water to remove the solvent by steam distillation, and then dried by a hot roll adjusted to 110°C to obtain a polymer (A-4) having a hydrogenation rate of 98% for the conjugated diene part and an MFR of 0.7 g / 10 min. Various physical property values, etc. of the obtained polymer (A-4) are shown in Table 1.

[0100] [Example 5]: Production of Polymer (A-5) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.25 part of N-(tert-butyldimethylsilyl)piperazine, and 0.11 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel, and 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.05 part of tetrachlorosilane was added, and further temperature-rising polymerization was carried out. The polymer thus obtained contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 70 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene with a vinyl bond content of 72 mol%. It was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 110,000, the total weight average molecular weight was 340,000, and the coupling rate was 75%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C and normal pressure, and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, stirred and poured into water, and the solvent was removed by steam distillation, and drying was carried out with a hot roll adjusted to 110°C to obtain a polymer (A-5) with a hydrogenation rate of the conjugated diene part of 98% and an MFR of 2.7 g / 10 min. Various physical property values of the obtained polymer (A-5) are shown in Table 1.

[0101] [Example 6]: Production of Polymer (A-6) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.08 part of piperidine, and 0.08 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel, and 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, followed by temperature-raising polymerization. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, followed by temperature-raising polymerization. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-raising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.05 part of tetrachlorosilane was added, and further temperature-raising polymerization was carried out. The polymer thus obtained contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 70 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene and having a vinyl group content of 70 mol%, and was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 160,000, the total weight average molecular weight was 320,000, and the coupling rate was 35%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogen addition reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C at normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, stirred and poured into water, and the solvent was removed by steam distillation, and drying was carried out with a hot roll adjusted to 110°C to obtain a polymer (A-6) having a hydrogenation rate of 98% for the conjugated diene part and an MFR of 2.7 g / 10 min. Various physical property values, etc. of the obtained polymer (A-6) are shown in Table 1.

[0102] [Example 7]: Production of Polymer (A-7) A polymer (A-7) having a hydrogenation rate of 83% for the conjugated diene part and an MFR of 5.2 g / 10 min was obtained using the same production method as that of polymer (A-1) except that the hydrogen supply amount in the hydrogenation reaction was reduced. Various physical property values, etc. of the obtained polymer (A-7) are shown in Table 1.

[0103] [Example 8]: Production of Polymer (A-8) Into a nitrogen-substituted reaction vessel, 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, and 0.12 part of n-butyllithium were charged. 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, and temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, and temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.16 part of 1,1'-(1,4-phenylene)bis(N-(3-(triethoxysilyl)propyl)methanimine) was added, and further temperature-rising polymerization was carried out. The polymer thus obtained contained structural units derived from 1,3-butadiene, a polymer block A having a vinyl bond content of 70 mol% and a polymer block B containing structural units derived from styrene, and a polymer block A' containing structural units derived from 1,3-butadiene and having a vinyl bond content of 70 mol%. It was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 100,000, the total weight average molecular weight was 290,000, and the coupling rate was 70%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxychloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C at normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, stirred and poured into water, and the solvent was removed by steam distillation. Drying was carried out using a hot roll adjusted to 110°C to obtain a polymer (A-8) having a hydrogenation rate of the conjugated diene portion of 97% and an MFR of 3.6 g / 10 min. Various physical property values of the obtained polymer (A-8) are shown in Table 1.

[0104] [Example 9]: Production of Polymer (A-9) Into a nitrogen-substituted reaction vessel, 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.12 part of piperidine, and 0.11 part of n-butyllithium were charged, and 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.16 part of 1,1'-(1,4-phenylene)bis(N-(3-(triethoxysilyl)propyl)methanimine) was added, and further temperature-rising polymerization was carried out. The obtained polymer contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 70 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene with a vinyl bond content of 70 mol%, and was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 100,000, the total weight average molecular weight was 340,000, and the coupling rate was 77%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxychloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C and normal pressure, and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, and it was stirred and poured into water to remove the solvent by steam distillation, and dried by a hot roll adjusted to 110°C to obtain a polymer (A-9) with a hydrogenation rate of the conjugated diene part of 96% and an MFR of 4.5 g / 10 min. Various physical property values of the obtained polymer (A-9) are shown in Table 1.

[0105] [Example 10]: Production of Polymer (A-10) Into a nitrogen-substituted reaction vessel, 550 parts of degassed and dehydrated cyclohexane, 4.1 parts of tetrahydrofuran, 0.11 part of piperidine, and 0.11 part of n-butyllithium were charged. 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, and temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, and temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.05 part of tetrachlorosilane was added, and further temperature-rising polymerization was carried out. The obtained polymer contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 52 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene and having a vinyl bond content of 54 mol%, and was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 110,000, the total weight average molecular weight was 340,000, and the coupling rate was 75%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C at normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, stirred and poured into water, and the solvent was removed by steam distillation, and drying was carried out with a hot roll adjusted to 110°C, whereby a polymer (A-10) with a hydrogenation rate of the conjugated diene part of 98% and an MFR of 1.3 g / 10 min was obtained. Various physical property values of the obtained polymer (A-10) are shown in Table 1.

[0106] [Example 11]: Production of Polymer (A-11) Into a nitrogen-substituted reaction vessel, 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.11 part of piperidine, and 0.11 part of n-butyllithium were charged. 20 parts of 1,3-butadiene were added at a polymerization initiation temperature of 40°C, and temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 10 parts of styrene were added at a polymerization initiation temperature of 40°C, and temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 50 parts of 1,3-butadiene and 20 parts of styrene were added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.05 part of tetrachlorosilane was added, and further temperature-rising polymerization was carried out. The polymer thus obtained contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 70 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block C containing a structural unit derived from 1,3-butadiene and a structural unit derived from styrene with a vinyl bond content of 70 mol%, and was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 110,000, the total weight average molecular weight was 340,000, and the coupling rate was 75%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxychloride were added into the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C at normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, stirred and poured into water, and the solvent was removed by steam distillation. Drying was carried out with a hot roll adjusted to 110°C to obtain a polymer (A-11) with a hydrogenation rate of the conjugated diene part of 98% and an MFR of 4.5 g / 10 min. Various physical property values, etc. of the obtained polymer (A-11) are shown in Table 2.

[0107] [Example 12]: Production of Polymer (A-12) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.11 part of piperidine, and 0.11 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel, and 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, followed by temperature-raising polymerization. After the polymerization conversion rate reached 99% or more, 20 parts of styrene was added at a polymerization initiation temperature of 40°C, followed by temperature-raising polymerization. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 34°C, 60 parts of 1,3-butadiene was added, and further temperature-raising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.05 part of tetrachlorosilane was added, and further temperature-raising polymerization was carried out. The obtained polymer contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 70 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene with a vinyl bond content of 70 mol%, and was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 110,000, the total weight average molecular weight was 340,000, and the coupling rate was 75%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C under normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, stirred and poured into water, and the solvent was removed by steam distillation, and drying was carried out with a hot roll adjusted to 110°C to obtain a polymer (A-12) with a hydrogenation rate of the conjugated diene portion of 98% and an MFR of 1.3 g / 10 min. Various physical property values of the obtained polymer (A-12) are shown in Table 2.

[0108] [Example 13]: Production of Polymer (A-13) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.11 part of piperidine, and 0.11 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel, and 5 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 20°C, 85 parts of 1,3-butadiene was added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.05 part of tetrachlorosilane was added, and further temperature-rising polymerization was carried out. The obtained polymer contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 70 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene with a vinyl bond content of 70 mol%, and was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 110,000, the total weight average molecular weight was 340,000, and the coupling rate was 75%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C at normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, stirred and poured into water, and the solvent was removed by steam distillation, and drying was carried out with a hot roll adjusted to 110°C to obtain a polymer (A-13) with a hydrogenation rate of the conjugated diene part of 98% and an MFR of 2.4 g / 10 min. Various physical property values, etc. of the obtained polymer (A-13) are shown in Table 2.

[0109] [Example 14]: Production of Polymer (A-14) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.11 part of piperidine, and 0.11 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel. 10 parts of styrene was added at a polymerization initiation temperature of 40°C, and temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 17°C, 90 parts of 1,3-butadiene was added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.05 part of tetrachlorosilane was added, and further temperature-rising polymerization was carried out. The obtained polymer was a block copolymer having a polymer block B containing a structural unit derived from styrene and a polymer block A containing a structural unit derived from 1,3-butadiene and having a vinyl bond content of 70%. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 110,000, the total weight average molecular weight was 340,000, and the coupling rate was 75%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C at normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, stirred and poured into water, and the solvent was removed by steam distillation. Drying was carried out with a hot roll adjusted to 110°C to obtain a polymer (A-14) having a hydrogenation rate of the conjugated diene portion of 98% and an MFR of 2.0 g / 10 min. Various physical property values of the obtained polymer (A-14) are shown in Table 2.

[0110] [Comparative Example 1]: Production of Polymer (A-15) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, and 0.11 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel, and 20 parts of 1,3-butadiene was added at a polymerization start temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization start temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.05 part of tetrachlorosilane was added, and further temperature-rising polymerization was carried out. The resulting polymer contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 70 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene with a vinyl bond content of 70 mol%, and was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 120,000, the total weight average molecular weight was 350,000, and the coupling rate was 75%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C at normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, and it was stirred and poured into water to remove the solvent by steam distillation, and dried with a hot roll adjusted to 110°C, thereby obtaining a polymer (A-15) with a hydrogenation rate of the conjugated diene part of 98% and an MFR of 3.1 g / 10 min. Various physical property values, etc. of the obtained polymer (A-15) are shown in Table 2.

[0111] [Comparative Example 2]: Production of Polymer (A-16) 800 parts of degassed and dehydrated cyclohexane, 0.03 part of tetrahydrofuran, 0.14 part of piperidine, and 0.14 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel. 30 parts of 1,3-butadiene was added at a polymerization initiation temperature of 70°C, and temperature-raising polymerization was carried out. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 20°C, 70 parts of 1,3-butadiene and 16 parts of tetrahydrofuran were added, and further temperature-raising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.06 part of tetrachlorosilane was added, and further temperature-raising polymerization was carried out. The obtained polymer was a block copolymer having a polymer block A containing a structural unit derived from 1,3-butadiene and having a vinyl bond content of 15 mol% and a polymer block A' containing a structural unit derived from 1,3-butadiene and having a vinyl bond content of 75 mol%. Further, for the obtained block copolymer, the 1st peak weight average molecular weight was 100,000, the total weight average molecular weight was 300,000, and the coupling rate was 75%. Thereafter, 0.05 part of diethylaluminum chloride and 0.11 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C and normal pressure, and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, and it was stirred and poured into water, and the solvent was removed by steam distillation. Drying was carried out with a hot roll adjusted to 110°C to obtain a polymer (A-16) having a hydrogenation rate of the conjugated diene portion of 98% and an MFR of 4.2 g / 10 min. Various physical property values, etc. of the obtained polymer (A-16) are shown in Table 2.

[0112] [Comparative Example 3]: Production of Polymer (A-17) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.05 part of piperidine, and 0.06 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel, and 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, followed by temperature-rising polymerization. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-rising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.002 part of tetrachlorosilane was added, and further temperature-rising polymerization was carried out. The obtained polymer contained a structural unit derived from 1,3-butadiene, and was a block copolymer having a polymer block A with a vinyl bond content of 70 mol% containing a structural unit derived from 1,3-butadiene, a polymer block B containing a structural unit derived from styrene, and a polymer block A' with a vinyl bond content of 70 mol% containing a structural unit derived from 1,3-butadiene. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 220,000, the total weight average molecular weight was 270,000, and the coupling rate was 8%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogen addition reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C at normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, stirred and poured into water, and the solvent was removed by steam distillation, and drying was carried out with a hot roll adjusted to 110°C to obtain a polymer (A-17) in which the hydrogenation rate of the conjugated diene part was 98% and the MFR was 4.8 g / 10 min. Various physical property values of the obtained polymer (A-17) are shown in Table 2.

[0113] [Comparative Example 4]: Production of Polymer (A-18) A polymer (A-18) in which the hydrogenation rate of the conjugated diene part was 60% and the MFR was 7.6 g / 10 min was obtained using the same production method as that of polymer (A-1) except that the hydrogen supply amount in the hydrogenation reaction was reduced. Various physical property values of the obtained polymer (A-18) are shown in Table 2.

[0114] [Comparative Example 5]: Production of Polymer (A-19) Into a nitrogen-substituted reaction vessel, 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, 0.06 part of piperidine, and 0.06 part of n-butyllithium were charged, and 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, followed by temperature-raising polymerization. After the polymerization conversion rate reached 99% or more, 10 parts of styrene was added at a polymerization initiation temperature of 40°C, followed by temperature-raising polymerization. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 70 parts of 1,3-butadiene was added, and further temperature-raising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.04 part of methyldichlorosilane was added, and further temperature-raising polymerization was carried out. The obtained polymer was a block copolymer having a polymer block A containing structural units derived from 1,3-butadiene with a vinyl bond content of 70 mol%, a polymer block B containing structural units derived from styrene, and a polymer block A' containing structural units derived from 1,3-butadiene with a vinyl bond content of 70 mol%. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 220,000, the total weight average molecular weight was 300,000, and the coupling rate was 75%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C at normal pressure and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, and it was stirred and poured into water, and the solvent was removed by steam distillation, and drying was carried out with a hot roll adjusted to 110°C, whereby a polymer (A-19) having a hydrogenation rate of the conjugated diene portion of 98% and an MFR of 1.2 g / 10 min was obtained. Various physical property values, etc. of the obtained polymer (A-19) are shown in Table 2.

[0115] [Comparative Example 6]: Production of Polymer (A-20) 550 parts of degassed and dehydrated cyclohexane, 14 parts of tetrahydrofuran, and 0.06 part of n-butyllithium were charged into a nitrogen-substituted reaction vessel, and 20 parts of 1,3-butadiene was added at a polymerization initiation temperature of 40°C, followed by temperature-raising polymerization. After the polymerization conversion rate reached 99% or more, 12 parts of styrene was added at a polymerization initiation temperature of 40°C, and temperature-raising polymerization was carried out. After the polymerization conversion rate reached 99% or more, the reaction solution was cooled to 30°C, 68 parts of 1,3-butadiene was added, and further temperature-raising polymerization was carried out. After the polymerization conversion rate reached 99% or more, 0.03 part of tetrachlorosilane was added, and further temperature-raising polymerization was carried out. The obtained polymer contained a structural unit derived from 1,3-butadiene, a polymer block A with a vinyl bond content of 70 mol%, a polymer block B containing a structural unit derived from styrene, and a polymer block A' containing a structural unit derived from 1,3-butadiene with a vinyl bond content of 70 mol%, and was a block copolymer. Also, for the obtained block copolymer, the 1st peak weight average molecular weight was 210,000, the total weight average molecular weight was 580,000, and the coupling rate was 75%. Thereafter, 0.04 part of diethylaluminum chloride and 0.10 part of bis(cyclopentadienyl)titanium furfuryloxy chloride were added to the reaction vessel and stirred. The hydrogenation reaction was started at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80°C. After 3.0 hours, the reaction solution was brought to 60°C and normal pressure, and withdrawn from the reaction vessel. Next, 0.2 part of 2,6-di-tert-butyl-p-cresol was added to the obtained polymer solution, and it was stirred and poured into water to remove the solvent by steam distillation, and dried by a hot roll adjusted to 110°C, whereby a polymer (A-20) with a hydrogenation rate of the conjugated diene portion of 98% and an MFR of 0.1 g / 10 min was obtained. Various physical property values, etc. of the obtained polymer (A-20) are shown in Table 2.

[0116] 3. Production of Adhesive Film and Evaluation of Adhesive Performance Using polyethylene (manufactured by Mitsubishi Chemical Corporation, YF30) as the base material layer and the polymers (A-1) to (A-20) manufactured above as the adhesive layer, a biaxial coextrusion apparatus equipped with a feed block type T-die was used to coextrude and mold the base material layer and the adhesive layer so that the thickness of the base material layer was 100 μm and the thickness of the adhesive layer was 10 μm, and adhesive films (Examples 1 to 14, Comparative Examples 1 to 6) were manufactured. The molding conditions (cylinder temperature, die temperature) at this time were as follows: extrusion temperature for the adhesive layer: 150 - 220 °C (hopper side - die side (°C)), extrusion temperature for the base material layer: 150 - 220 °C (hopper side - die side (°C)), die temperature: 220 °C. When manufacturing the adhesive film, as stabilizers, the product named "Tinuvin 326" manufactured by Ciba Specialty Chemicals and the product named "Adekastab LA52" manufactured by Asahi Denka Co., Ltd. were each blended at 0.2 parts by mass with respect to 100 parts by mass of the block copolymer. For the adhesive films thus obtained, the following various properties were evaluated. The evaluation methods are as follows.

[0117] [Extrusion moldability] The adhesive films obtained by coextrusion molding were visually evaluated according to the following four evaluation criteria of A to D. (Evaluation criteria) A: There was no surface roughness and no thickness unevenness was observed. B: There was no surface roughness, but thickness unevenness was observed. C: Melt fracture was observed in a part of the surface. D: Melt fracture was observed over the entire surface and the moldability was poor.

[0118] [Peel strength] Each of the adhesive films of the examples and comparative examples was polished on the surface of a SUS plate (SUS mirror finish plate) so that the surface roughness was 2.0 - 5.0 μm, and in an environment of room temperature 23 °C and relative humidity 50%, using a tabletop laminator, at a pressure of 5.9×10 5They were each pasted at a speed of 30 mm / min. After leaving them for 30 minutes in an environment of room temperature 23°C and relative humidity 50%, in accordance with the method of JIS Z 0237:2009, the 180-degree peel strength of these films (25 mm width) was measured at a speed of 300 mm / min, and this was taken as the initial peel strength. From the obtained initial peel strength, the peel strength was judged according to the following four criteria of A to D. A: 0.50 N / 10 mm or more, and the peel strength is extremely good. B: 0.30 N / 10 mm or more and less than 0.50 N / 10 mm, and the peel strength is good. C: 0.10 N / 10 mm or more and less than 0.30 N / 10 mm, and the peel strength is at an acceptable level. D: Less than 0.10 N / 10 mm, and the peel strength is poor.

[0119] [Low tack progression] Each of the pressure-sensitive adhesive films of the examples and comparative examples was pasted on the surface of a plate similar to the SUS plate used in the above peel strength evaluation at room temperature 23°C and relative humidity 50% using a tabletop laminator at a pressure of 5.9×10 5 Pa and a speed of 30 mm / min. Next, each pressure-sensitive adhesive film was left at 60°C for 30 minutes and left at 60°C for 1 week, and in accordance with the method of JIS Z 0237, the 180-degree peel strength of these films (25 mm width) was measured at a speed of 300 mm / min, and these were taken as the initial peel strength and the peel strength over time, respectively. The change ratio (tack progression ratio) of the peel strength over time from the initial peel strength was calculated by the following formula (a). Change ratio (tack progression ratio) = (Peel strength over time / Initial peel strength) …(a) From the obtained change ratio (tack progression ratio), the progression of tackiness was judged according to the following four criteria of A to D. A: The tack progression ratio is in the range of 1.2 or less, and the low tack progression is extremely good. B: The tack progression ratio exceeds 1.2 and is in the range of 1.6 or less, and the low tack progression is good. C: The tack progression ratio exceeds 1.6 and is in the range of 2.0, and the tack progression is at an acceptable level. D: The sticking progress ratio exceeds 2.0, and the low sticking progress property is poor.

[0120] [Developability] Each pressure-sensitive adhesive film of the examples and comparative examples was attached to a polypropylene film under the environment of 23°C at room temperature and 50% relative humidity using a tabletop laminator at a pressure of 5.9×10 5 Pa and a speed of 30 m / min. Then, after leaving it at 23°C for 24 hours, in accordance with the method of JIS Z 0237:2009, the 180-degree peel strength of the pressure-sensitive adhesive film (25 mm width) was measured at a speed of 15 m / min, and this was used as the developing force. From the obtained developing force, the developability was determined according to the following four criteria of A to D. A: Less than 0.05 N / 10 mm, and the developability is extremely good. B: 0.05 N / 10 mm or more and less than 0.10 N / 10 mm, and the developability is good. C: 0.10 N / 10 mm or more and less than 0.20 N / 10 mm, and the developability is at an acceptable level. D: 0.20 N / 10 mm or more, and there is concern about the adverse effect on the rewinding from the film roll, and the developability is poor.

[0121] [Adhesive residue] In the above evaluation of the low sticking progress property, after evaluating the peel strength over time, the surface of the SUS plate was visually observed to confirm the presence or absence of residues of the adhesive layer. From the obtained presence or absence of residues, the adhesive residue was determined according to the following two criteria of A and B. A: There is no residue, and the adhesive residue is good. B: Residues are observed, and due to the high contaminability to the polar adherend, the adhesive residue is poor.

[0122] [Table 1]

[0123] [Table 2]

[0124] In Tables 1 and 2, the abbreviations of the monomer, starting-end modifier, coupling agent, and post-modifier represent the following compounds. The number of parts of the monomer represents the charged amount (parts by mass). · BD: 1,3-butadiene · ST: Styrene · R-1: Piperidine · R-2: N-(tert-butyldimethylsilyl)piperazine · C-1: Tetrachlorosilane · C-2: Methyldichlorosilane · C-3: 1,1'-(1,4-phenylene)bis(N-(3-(triethoxysilyl)propyl)methanimine)

[0125] As shown in Tables 1 and 2, it was found that the pressure-sensitive adhesive films of Examples 1 to 14 using the [A] block copolymer exhibited good balance in extrusion moldability, adhesive strength (peel strength), low-tack progression, developability, and residual paste characteristics. In contrast, Comparative Example 1 and Comparative Example 6 in which no starting-end modifier was used during polymerization had an evaluation of "D" for adhesive strength and developability. Also, the pressure-sensitive adhesive film of Comparative Example 3 with a low content of the polymer (A1) was further inferior in low-tack progression and residual paste characteristics, and the pressure-sensitive adhesive film of Comparative Example 5 using a bifunctional coupling agent was also inferior in extrusion moldability and low-tack progression. Further, Comparative Example 2 having no styrene block had an evaluation of "D" for adhesive strength and tackiness. The pressure-sensitive adhesive film of Comparative Example 4 using a block copolymer with a low hydrogenation rate of 60% was inferior in extrusion moldability, and the low-tack progression and residual paste characteristics were also insufficient.

[0126] From the above results, it became clear that the block copolymer of the present invention exhibits good balance in molding processability, adhesive performance, and developability. Furthermore, it was confirmed that the block copolymer of the present invention is less likely to cause tack progression and is less likely to leave residual paste when peeled from the adherend.

Claims

1. When the composition ratios (molar ratios) of the structural units represented by the following formula (1), the structural units represented by the following formula (2), the structural units represented by the following formula (3), and the structural units represented by the following formula (4) in the polymer are p, q, r, and s, respectively, it is a block copolymer in which the value α represented by the following mathematical formula (i) is 0.75 or more. The block copolymer contains 10% by mass or more of a polymer (A1) having a multi-branched structure with 4 or more polymer chains. The polymer chain has a polymer block A containing 70% by mass or more of a structural unit derived from a conjugated diene compound and a polymer block B containing 70% by mass or more of a structural unit derived from an aromatic vinyl compound. A block copolymer having a functional group F containing at least one element selected from the group consisting of nitrogen, silicon, oxygen, and sulfur at a part or all of the terminals in the 4 or more polymer chains, and the functional group F contains at least nitrogen. α = (p + (0.5 × r)) / (p + q + (0.5 × r) + s) … (i) 【Chemical 1】

2. The block copolymer according to Claim 1, containing 20 to 90% by mass of the polymer (A1).

3. The block copolymer according to Claim 1, containing 50 to 80% by mass of the polymer (A1).

4. The block copolymer according to any one of Claims 1 to 3, having at least one selected from the group consisting of a primary amino group, a secondary amino group, and a tertiary amino group as the functional group F.

5. The block copolymer according to any one of Claims 1 to 4, having the functional group F at the terminal of the polymer block A or the polymer block B.

6. The polymer (A1) has a structure in which 4 or more polymer chains are bonded to a partial structure derived from a coupling agent. The block copolymer according to any one of Claims 1 to 5, wherein the coupling agent has the functional group F.

7. The block copolymer according to any one of Claims 1 to 6, wherein the value β represented by the following mathematical formula (ii) in the polymer block A exceeds 0.

20. β = (p + q) / (p + q + (0.5 × r) + s) … (ii)

8. The block copolymer according to Claim 7, wherein the value β is greater than 0.

60.

9. The block copolymer according to any one of Claims 1 to 8, wherein the polymer (A1) further contains a polymer block C having a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound.

10. The block copolymer according to any one of claims 1 to 9, comprising a linear polymer (A2). **Claim 11** An adhesive obtained by using the block copolymer according to any one of claims 1 to 10.

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