JP6637254B2 - Adhesive composition and adhesive tape - Google Patents

Description

  The present invention relates to an adhesive composition and an adhesive tape.

  In recent years, from the viewpoint of reducing environmental pollution and improving the working environment, hot-melt adhesive compositions have been widely used as adhesive compositions. As the block copolymer contained in the hot melt type adhesive composition, a styrene-based block copolymer is widely used.

  For example, Patent Literatures 1 and 2 disclose an adhesive composition using a triblock copolymer and a diblock copolymer as a styrene-based block copolymer.

  Patent Document 3 describes an adhesive composition using various hydrogenated styrene-based block copolymers, and Examples and Comparative Examples have a vinyl aromatic monomer content of 0%. There are described various types of adhesive compositions comprising a hydrogenated styrene-based block copolymer in an amount of at least 20% by mass or 20% by mass, a tackifier, and an oil.

  Patent Document 4 discloses an adhesive composition comprising a styrene-based block copolymer and a tackifying resin, in which a partially hydrogenated styrene-based block copolymer and a non-hydrogenated styrene-based block copolymer are added to a styrene-based block copolymer. An adhesive composition using a polymer or a partially hydrogenated styrene-based block copolymer and a completely hydrogenated block copolymer is described.

JP-A-64-81877 JP-A-61-278578 International Publication No. WO 2001/85818 JP-A-7-157738

  The adhesive composition used for the adhesive tape has a high adhesive strength and a high adhesive strength after immersion in warm water, and has a high adhesive strength before and after irradiation with ultraviolet rays (hereinafter, also simply referred to as “UV”). A balance between low change, high tack and high holding power is required. However, as a result of intensive studies by the inventors of the present application, adhesive compositions such as those described in Patent Documents 1 to 4 have insufficient properties required for the adhesive composition, In addition, it was found that there is still room for improvement in the adhesive strength, the adhesive strength after immersion in warm water, the change in the adhesive strength before and after ultraviolet irradiation, the tack, and the balance performance of the holding power.

  An object of the present invention is to provide an adhesive composition having a high adhesive strength, a high adhesive strength after immersion in warm water, a small change in the adhesive strength before and after irradiation with ultraviolet light, a high tack, and an excellent balance of high holding power. And an adhesive tape having the adhesive composition.

The present invention is as follows.
[1]
A tacky adhesive composition containing 20 parts by mass to 400 parts by mass of a tackifying resin, based on 100 parts by mass of a block copolymer having a polymer block mainly composed of vinyl aromatic monomer units,
The block copolymer has a different vinyl aromatic monomer unit content, and the structure before hydrogenation has two or more types of moieties including any of the following formulas (i) to (vi). An adhesive composition containing a hydrogenated block copolymer.
(AB) _n ... (i)
B- (AB) _n (ii)
A- (BA) _n (iii)
A- (BA) _n -X (iv)
[(AB) _k ] _m -X (v)
[(AB) _k -A] _m -X (vi)
(In the formulas (i) to (vi), A represents a polymer block mainly composed of a vinyl aromatic monomer unit, B represents a polymer block mainly composed of a conjugated diene monomer unit, X represents a residue of a coupling agent, n represents the formula (i) represents an integer from 2 to 5, in formula (ii) ~ (vi), m, n and k are an integer of 1 or more Represents.)
[2]
Item 3. The pressure-sensitive adhesive composition according to item 1, wherein at least one of the partially hydrogenated block copolymers has a hydrogenation ratio of 10 mol% to 80 mol% based on the total number of moles of the conjugated diene.
[3]
3. The adhesive composition according to item 1 or 2, wherein the partially hydrogenated block copolymer has a structure before hydrogenation containing any of the following formulas (iv) to (vi).
A- (BA) _n -X (iv)
[(AB) _k ] _m -X (v)
[(AB) _k -A] _m -X (vi)
(In the formulas (iv) to (vi), A represents a polymer block mainly containing a vinyl aromatic monomer unit, B represents a polymer block mainly containing a conjugated diene monomer unit, X represents a residue of a coupling agent, m, n and k represents an integer of 1 or more.)
[4]
At least one of the above partially hydrogenated block copolymers is a partial water having one polymer block mainly composed of a vinyl aromatic monomer unit and one polymer block mainly composed of a conjugated diene monomer. The pressure-sensitive adhesive composition according to any one of items 1 to 3, further comprising a subblock copolymer (d).
[5]
Of the partially hydrogenated block copolymer, the partially hydrogenated block copolymer (d) is based on 100% by mass of the partially hydrogenated block copolymer containing the partially hydrogenated block copolymer (d). The adhesive composition according to item 4, comprising 20% by mass to 80% by mass.
[6]
6. The adhesive composition according to any one of items 1 to 5, wherein at least one kind of the partially hydrogenated block copolymer contains a partially hydrogenated block copolymer (r) having a radial structure.
[7]
An adhesive tape having the adhesive composition according to any one of items 1 to 6.

  According to the present invention, a high adhesive strength, having a high adhesive strength after immersion in warm water, a small change in the adhesive strength before and after UV irradiation, a high tack, an adhesive composition excellent in the balance of high holding power, And an adhesive tape having the adhesive composition.

  Hereinafter, a mode for carrying out the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist.

<< Adhesive composition >>
The adhesive composition of the present embodiment contains 20 parts by mass to 400 parts by mass of a tackifying resin based on 100 parts by mass of a block copolymer having a polymer block mainly composed of a vinyl aromatic monomer unit. A pressure-sensitive adhesive composition,
The above block copolymer contains two or more kinds of partially hydrogenated block copolymers having different vinyl aromatic monomer unit contents.

<Block copolymer>
The block copolymer in the present embodiment is a block copolymer having a polymer block mainly composed of vinyl aromatic monomer units. Examples of such a block copolymer include a polymer block having a vinyl aromatic monomer unit and a conjugated diene monomer unit, and mainly containing a vinyl aromatic monomer unit.

  In the present specification, a structural unit constituting a polymer is referred to as a “monomer unit”, and when described as a material of the polymer, it is simply referred to as a “monomer”. In the specification of the present application, “mainly” means that the content of a predetermined monomer unit in a block is 70% by mass or more. The polymer block mainly composed of a vinyl aromatic monomer unit may have a content of a predetermined monomer unit of 70% by mass or more, preferably 80% by mass, more preferably 90% by mass or more. . In the specification of the present application, the “polymer block mainly composed of a conjugated diene monomer” also includes a polymer block mainly composed of a hydrogenated conjugated diene monomer.

In the present embodiment, the structure of the partially hydrogenated block copolymer before hydrogenation (hereinafter, also referred to as “hydrogenation”) is not particularly limited. For example, the structure is represented by the following formulas (i) to (vi). Structure.
(AB) n (i)
B- (AB) n (ii)
A- (BA) n (iii)
A- (BA) n-X (iv)
[(AB) k] mX (v)
[(AB) k-A] m-X (vi)

  In the above formulas (i) to (vi), A represents a polymer block mainly composed of vinyl aromatic monomer units, B represents a polymer block mainly composed of conjugated diene monomer units, X represents a residue of a coupling agent or a residue of a polymerization initiator such as a polyfunctional organic lithium, and m, n, and k represent an integer of 1 or more, preferably an integer of 1 to 5.

  When a plurality of polymer blocks A and B exist in the block copolymer before hydrogenation, the structures such as molecular weight and composition may be the same or different. In the above formulas (i) to (vi), X represents a residue of a coupling agent or a residue of a polymerization initiator such as polyfunctional organolithium. The partially hydrogenated block copolymer may be a mixture of a coupling body in which X is a residue of a coupling agent and a non-coupling body having no X or in which X is a residue of a polymerization initiator. Good. The boundaries and the extreme ends of each block do not necessarily need to be clearly distinguished. For example, a copolymer block of a vinyl aromatic monomer unit and a conjugated diene monomer unit may be present.

  The distribution of vinyl aromatic monomer units in the polymer block mainly composed of vinyl aromatic monomer units and in the polymer block mainly composed of conjugated diene monomer units is not particularly limited, and the distribution is uniform. Even if they are distributed, they may be distributed in a tapered shape, a stepped shape, a convex shape, or a concave shape. Further, a crystal part may be present in the polymer block. In a polymer block mainly composed of a vinyl aromatic monomer unit, a plurality of segments having different contents of the vinyl aromatic monomer unit may coexist.

  The adhesive composition according to the present embodiment has a high adhesive strength, a high adhesive strength after immersion in warm water, a low change in adhesive strength before and after irradiation with ultraviolet light, a high tack, and a viewpoint of a balance of high holding power. At least one of the polymers is a partially hydrogenated block copolymer (a) having a vinyl aromatic monomer unit content of 10% by mass to 25% by mass, and at least one other is a vinyl aromatic monomer unit. It is preferably a partially hydrogenated block copolymer (b) having a monomer unit content of more than 25% by mass.

  The content of the vinyl aromatic monomer unit in the partially hydrogenated block copolymer (a) is, for example, 14 mass from the viewpoint of a balance between high adhesive strength, high adhesive strength after immersion in warm water, high tack, and high holding power. % To 25% by mass, or 16% to 25% by mass.

  The content of the polymer block mainly composed of vinyl aromatic monomer units in the partially hydrogenated block copolymer (a) is, for example, 13% by mass or less from the viewpoint of suppressing a change in adhesive strength before and after irradiation with ultraviolet rays. It can be 25% by mass, 14% by mass to 24% by mass, or 15% by mass to 20% by mass.

  The content of the vinyl aromatic monomer unit in the partially hydrogenated block copolymer (b) is, for example, 26 mass from the viewpoint of a balance between high adhesive strength, high adhesive strength after immersion in warm water, high tack, and high holding power. % To 45% by mass, 27% to 40% by mass, or 28% to 35% by mass.

  In the partially hydrogenated block copolymer (b), the content of the polymer block mainly composed of a vinyl aromatic monomer unit is controlled from the viewpoint of suppressing a change in adhesive force before and after irradiation with ultraviolet rays and increasing a holding power. For example, it can be 26% by mass to 45% by mass, 27% by mass to 40% by mass, or 28% by mass to 35% by mass.

  The content of the vinyl aromatic monomer unit in the block copolymer and the content of the polymer block mainly composed of the vinyl aromatic monomer unit can be measured by the method described in Examples described later.

    In the adhesive composition of the present embodiment, from the viewpoint of low viscosity and high holding power, at least one kind of partially hydrogenated block copolymer contains a partially hydrogenated block copolymer (r) having a radial structure. Is preferred. Here, in the present specification, the “radial structure” refers to a structure in which three or more polymers are bonded to a residue X, and for example, A- (BA) n -X (n ≧ 3 ), [(AB) k] mX (m ≧ 3), and [(AB) kA] mX (m ≧ 3).

  As the structure of the partially hydrogenated block copolymer (r) having a radial structure, from the viewpoints of high adhesive strength, low viscosity, and high holding power, [(AB) k] m-X and [(A- B) k-S] m-X (wherein m represents an integer of 3 to 6, k represents an integer of 1 to 4, and more preferably m represents an integer of 3 to 4). At least one structure selected from the group consisting of: From the viewpoint of reducing the change in adhesive strength before and after ultraviolet irradiation, one of the partially hydrogenated block copolymers (a) and (b) contains the partially hydrogenated block copolymer (r) having a radial structure. It is more preferable that both the partially hydrogenated block copolymers (a) and (b) contain a partially hydrogenated block copolymer (r) having a radial structure.

  From the viewpoint of high tack and high adhesive strength after immersion in hot water, at least one kind of partially hydrogenated block copolymer is mainly composed of vinyl aromatic monomer units. It is preferable to contain a partially hydrogenated block copolymer (d) having one polymer block and one partially hydrogenated polymer block mainly composed of a conjugated diene monomer.

  From the viewpoint of high tack, the lower limit of the content of the partially hydrogenated block copolymer (d) is based on 100% by mass of the partially hydrogenated block copolymer containing the partially hydrogenated block copolymer (d). For example, it can be 20% by mass or more, 30% by mass or more, 50% by mass or more, 65% by mass or more, or 70% by mass or more. In addition, the upper limit of the content of the partially hydrogenated block copolymer (d) is to increase the adhesive strength and the adhesive strength after immersion in warm water and to reduce the change in the adhesive strength before and after irradiation with ultraviolet rays. It can be, for example, 90% by mass or less, 85% by mass or less, or 80% by mass or less based on 100% by mass of the partially hydrogenated block copolymer containing the block copolymer (d).

  From the viewpoint of high tack, one of the partially hydrogenated block copolymers (a) and (b) preferably contains the partially hydrogenated block copolymer (d), and the partially hydrogenated block copolymer is preferably used. More preferably, both (a) and (b) contain a partially hydrogenated block copolymer (d).

  In the adhesive composition according to the present embodiment, at least one kind of the partially hydrogenated block copolymer preferably has a hydrogenation rate of 10 mol% to 80 mol% based on the total number of moles of the conjugated diene. When the hydrogenation rate is within the above range, the balance of high tack, high adhesive strength after immersion in warm water, and low change in adhesive strength before and after ultraviolet irradiation is excellent. The hydrogenation rate of either the partially hydrogenated block copolymer (a) or (b) is more preferably 10 mol% to 80 mol% based on the total number of moles of the conjugated diene, and the partially hydrogenated block copolymer More preferably, both of the hydrogenation rates of the polymers (a) and (b) are 10 mol% to 80 mol% based on the total number of moles of the conjugated diene.

  The range of the hydrogenation rate is, for example, independently 10 mol% to 80 mol%, 20 mol% to 74 mol%, 31 mol% to 70 mol%, 33 mol% to 63 mol% for each of the two or more types of partially hydrogenated polymers. , 35 mol% to 59 mol%. The hydrogenation rate of the double bond can be adjusted by controlling the hydrogenation amount and the hydrogenation reaction time in the hydrogenation step described below. Further, the hydrogenation rate can be determined by a method described in Examples described later.

  Before the hydrogenation, the vinyl content in the conjugated diene monomer unit may be, for example, 15 mol% to 75 mol%, 25 mol% to 55 mol%, or 35 mol% independently of each of the two or more kinds of partially hydrogenated polymers. ４５45 mol%. When the vinyl content in the conjugated diene monomer unit before hydrogenation is 15 mol% or more, tackiness, adhesive strength, and holding power tend to be further improved. When the vinyl content in the conjugated diene monomer unit before hydrogenation is 75 mol% or less, tackiness and heat aging resistance tend to be further improved. Here, in the present specification, the “vinyl content” refers to a conjugate incorporated in a 1,2-bond, 1,4-bond, or 1,4-bond bonding mode of a conjugated diene before hydrogenation. The ratio of the conjugated diene monomer unit incorporated by 1,2-bond and 3,4-bond to the total mol amount of the diene monomer unit. The vinyl content can be measured by NMR, and specifically, can be measured by the method described in Examples described later. The distribution of the vinyl content in the block mainly composed of the conjugated diene monomer unit is not limited.

  The adhesive composition in the present embodiment preferably has a melt flow rate (MFR, 200 ° C., 5 kgf) of the partially hydrogenated block copolymer of 0.1 g / 10 min to 50 g / 10 min, For example, it can be 0.2 g / 10 min to 20 g / 10 min, 0.3 g / 10 min to 10 g / 10 min, or 0.4 g / 10 min to 5 g / 10 min. When the MFR of the partially hydrogenated block copolymer is 0.1 g / 10 min or more, tackiness, adhesive strength, holding power, and high resistance to exudation from the edge during tape lamination tend to be further improved. is there. Further, when the MFR of the partially hydrogenated block copolymer is 50 g / 10 minutes or less, coating properties and discoloration resistance tend to be further improved.

  The adhesive composition according to the present embodiment includes a polymer block copolymer mainly composed of a vinyl aromatic monomer unit, and a copolymer block copolymer of two or more partially hydrogenated blocks having different vinyl aromatic monomer unit contents. In addition to the polymer, other block copolymers having blocks mainly composed of vinyl aromatic monomer units (hereinafter, also simply referred to as “other block copolymers”) may be included.

  The other block copolymer is not particularly limited, for example, styrene butadiene-based block copolymer, styrene-isoprene-based block copolymer, hydrogenated styrene-butadiene-based block copolymer, hydrogenated styrene-isoprene System block copolymers.

  Other block copolymers are one polymer block mainly composed of vinyl aromatic monomer units and one polymer mainly composed of conjugated diene monomers, from the viewpoint of the balance between high tack and high adhesion. It is preferably a block copolymer having a block.

  The upper limit of the content of the other block copolymer can be, for example, 50% by mass or less, 40% by mass or less, 30% by mass or less, or 20% by mass or less of 100% by mass of the block copolymer. .

  The other block copolymer may be a completely hydrogenated block copolymer or a non-hydrogenated block copolymer. Here, in the specification of the present application, “completely hydrogenated block copolymer” refers to a block copolymer having a hydrogenation rate of 97 mol% or more based on the total number of moles of the conjugated diene. “Block copolymer” refers to a block copolymer having a hydrogenation rate of 0 mol%.

  From the viewpoint of the softness of the adhesive composition, when the other block copolymer is a completely hydrogenated type block copolymer, in the conjugated diene monomer unit in the block copolymer before hydrogenation The vinyl content can be, for example, 35 mol% to 80 mol%, 40 mol% to 75 mol%, and 50 mol% to 75 mol%.

  The adhesive composition in the present embodiment has a high adhesive strength, a high adhesive strength after immersion in hot water, a low change in the adhesive strength before and after irradiation with ultraviolet light, a high tack, and a viewpoint of a balance between high holding power. Is preferably 60% by mass or more, for example, 70% by mass, 80% by mass or more, or 90% by mass or more.

  The adhesive composition in the present embodiment has a high adhesive strength, a high adhesive strength after immersion in hot water, a low change in the adhesive strength before and after irradiation with ultraviolet light, a high tack, and a viewpoint of a balance between high holding power. The content of the partially hydrogenated block copolymers (a) and (b) is preferably independently 20% by mass or more, for example, 30% by mass or more, or 40% by mass or more. it can.

  The adhesive composition in the present embodiment has a high adhesive strength, a high adhesive strength after immersion in warm water, a high tack, and a viewpoint of high holding power.From the viewpoint of the block copolymer, a hydroxyl group, an acid anhydride group, an epoxy group, and an amino group are used. It preferably has at least one functional group selected from the group consisting of a group, an amide group, a silanol group, and an alkoxysilane group. Among them, the block copolymer more preferably has at least one functional group selected from the group consisting of an amino group and an amide group, and further preferably has an amino group.

  Furthermore, from the viewpoint of high adhesive strength after immersion in warm water, the partially hydrogenated block copolymer is selected from the group consisting of a hydroxyl group, an acid anhydride group, an epoxy group, an amino group, an amide group, a silanol group, and an alkoxysilane group. It preferably has at least one functional group. Further, it is more preferable that the partially hydrogenated block copolymer contains 2 mol or more of at least one functional group selected from the group consisting of an amino group and an amide group per 1 mol of the molecule.

<Tackifying resin>
Examples of the tackifier resin used in the present embodiment are not particularly limited. For example, rosin derivatives (including tung oil resin), tall oil, tall oil derivatives, rosin ester resins, natural and synthetic terpene resins, and aliphatic hydrocarbons Resin, aromatic hydrocarbon resin, mixed aliphatic-aromatic hydrocarbon resin, coumarin-indene resin, phenol resin, p-tert-butylphenol-acetylene resin, phenol-formaldehyde resin, xylene-formaldehyde resin, oligomer of monoolefin, Diolefin oligomer, aromatic hydrocarbon resin, hydrogenated aromatic hydrocarbon resin, cycloaliphatic hydrocarbon resin, hydrogenated hydrocarbon resin, hydrocarbon resin, hydrogenated tung oil resin, hydrogenated oil resin, hydrogenated oil An ester of a resin and a monofunctional or polyfunctional alcohol is exemplified. These may be used alone or in combination of two or more. In the case of hydrogenation, all of the unsaturated groups may be hydrogenated, or some may be left.

  The tackifier resin used in the present embodiment preferably contains a tackifier resin having a softening point of 80 ° C. or higher in terms of adhesive strength, holding power, and high resistance to bleeding from the end during tape lamination. The softening point of the tackifier resin is more preferably 85 ° C. or higher, still more preferably 95 ° C. or higher, and even more preferably 100 ° C. or higher. The upper limit of the softening point of the tackifier resin is not particularly limited, but is preferably 145 ° C. or lower. The softening point is a value measured by JIS K2207 ring and ball method.

  When high adhesiveness, a change over time in adhesive strength or creep performance, etc. are particularly required, a non-blocking adhesive which can be used in the adhesive composition of the present embodiment is added to the adhesive composition. 20 to 75% by mass of a tackifier having an affinity for a block (usually a middle block) of a glass phase, and a tackifier having an affinity for a block (usually an outer block) of a glass phase of a block copolymer. More preferably, the content is 3 to 30% by mass.

  The tackifier having an affinity for the block of the glass phase of the block copolymer is not particularly limited, but for example, a terminal block tackifier resin is preferable. Such a tackifier is not particularly limited, and examples thereof include a resin having mainly an aromatic group such as a homopolymer or a copolymer containing vinyltoluene, styrene, α-methylstyrene, coumarone or indene. Among these, Kristalex and Plastolyn (trade name, manufactured by Eastman Chemical Company) having α-methylstyrene are preferable. The content of the tackifier having an affinity for the block of the glass phase of the block copolymer is preferably 3 to 30% by mass, more preferably 5 to 20% by mass, based on the total amount of the adhesive composition. And more preferably 6 to 12% by mass.

When high initial adhesive strength, high wettability, low melt viscosity of the adhesive composition or high coatability are particularly required, a petroleum resin having an aroma content of 3 to 12% by mass, more preferably an aroma resin It is preferable to use a petroleum resin having a content of 3 to 12% by mass and hydrogenated as a tackifier. The aroma content of the tackifier in this case is preferably 3 to 12% by mass, and more preferably 4 to 10% by mass.
When higher weather resistance (low change in adhesion after UV irradiation) is required, the tackifier is preferably a hydrogenated tackifier resin. "Hydrogenated tackifying resin" refers to a tackifying resin obtained by hydrogenating an aliphatic tackifying resin containing an unsaturated bond or an aromatic tackifying resin containing an unsaturated bond to an arbitrary hydrogenation rate. Say. The higher the hydrogenation rate, the better.
Examples of the hydrogenated tackifying resin include Alcon M and Ascon P (trade name, manufactured by Arakawa Chemical Industry Co., Ltd.), Clearon P (trade name, manufactured by Yashara Chemical Co., Ltd.), and Imarv P (trade name, manufactured by Idemitsu Kosan Co., Ltd.) And the like.

  The content of the tackifier in the adhesive composition of the present embodiment is 20 parts by mass or more and 400 parts by mass or less, preferably 70 parts by mass or more and 350 parts by mass, based on 100 parts by mass of the block copolymer. Or less, more preferably 120 to 300 parts by mass, and even more preferably 140 to 250 parts by mass. When the content of the tackifier is within the above range, tackiness, adhesive strength, holding power, coating properties, and discoloration resistance tend to be further improved.

<Other additives>
The adhesive composition of the present embodiment is, in addition to the block copolymer and the tackifier, if necessary, an oil, an antioxidant, a weathering agent, an antistatic agent, a lubricant, a filler, a wax, and the like. May be included.

  Examples of the oil include, but are not particularly limited to, for example, a paraffinic oil mainly containing paraffinic hydrocarbons, a naphthenic oil mainly containing naphthenic hydrocarbons, and an aromatic oil mainly containing aromatic hydrocarbons. Oil. Of these, oils that are colorless and substantially odorless are preferred. One type of oil may be used, or two or more types may be used in combination.

  The paraffin-based oil is not particularly limited. For example, Diana Process Oil PW-32, PW-90, PW-150, PS-430 (manufactured by Idemitsu Kosan), Syntax PA-95, PA-100, PA-140 ( Kobe Oil Chemical Co., Ltd.), JOMO Process P200, P300, P500, 750 (manufactured by Japan Energy), Sumper 110, 115, 120, 130, 150, 2100, 2280 (manufactured by Nippon Sun Oil), Fuccoal Process P-100, P -200, P-300, P-400, P-500 (manufactured by Fujikosan) and the like.

  Examples of the naphthenic oil include, but are not limited to, Diana Process Oil NP-24, NR-26, NR-68, NS-90S, NS-100, NM-280 (manufactured by Idemitsu Kosan), and Syntax N- 40, N-60, N-70, N-75, N-80 (manufactured by Kobe Oil Chemical), Shellflex 371JY (manufactured by Shell Japan), JOMO Process R25, R50, R200, R1000 (manufactured by Japan Energy), Sansen Oil 310, 410, 415, 420, 430, 450, 380, 480, 3125, 4130, 4240 (manufactured by Nippon San Petroleum), Fuccoal New Flex 1060W, 1060E, 1150W, 1150E, 1400W, 1400E, 2040E, 2050N (Fujikosan Made), Petrex Process Oil PN 3, PN-3M, PN-3N-H (Yamabun Yuka), and the like.

Further, the aromatic oil is not particularly limited. For example, Diana Process Oil AC-12, AC-640, AH-16, AH-24, AH-58 (made by Idemitsu Kosan), Syntax HA-10, HA -15, HA-30, HA-35 (manufactured by Kobe Oil Chemical), Cosmo Process 40, 40A, 40C, 200A, 100, 1000 (manufactured by Cosmo Oil Lubricant), JOMO Process X50, X100E, X140 (manufactured by Japan Energy), JSO Aroma 790, Nitoprene 720L (manufactured by Nippon Sun Oil), Fuccoal Aromax 1, 3, 5, EXP1 (manufactured by Fujikosan), Petrex Process Oil LPO-R, LPO-V, PF-2 (Yamabun Yuka Manufactured).
When higher weather resistance is required, it is preferable to use a paraffinic oil.

  From the viewpoint of the balance between high holding power, adhesive strength, and adhesive residue resistance, the oil content is preferably 10 parts by mass to 150 parts by mass with respect to 100 parts by mass of the block copolymer, for example, 30 parts by mass. Part to 130 parts by mass, or 50% by mass to 100 parts by mass.

  Although it does not specifically limit as an antioxidant, For example, a phenolic antioxidant, a sulfuric antioxidant, a phosphorus antioxidant, etc. are mentioned.

It is preferable to add a weathering agent from the viewpoint of high weather resistance (low adhesive force change after UV irradiation).
Examples of the weathering agent include benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzoate-based ultraviolet absorbers, hindered amine-based light stabilizers, and inorganic ultraviolet absorbers such as fine particle cerium oxide. From the viewpoint of higher weather resistance, a benzotriazole-based ultraviolet absorber or a hindered amine-based light stabilizer is preferred, and a combination use of a benzotriazole-based ultraviolet absorber and a hindered amine-based light stabilizer is more preferred.

The weathering agent content in the adhesive composition of the present embodiment is preferably 0.03% by mass or more, more preferably 0.05% by mass or more, and 0.07% by mass or more from the viewpoint of high weather resistance. Is more preferred.
In addition, the content of the weathering agent in the adhesive composition of the present embodiment is preferably 1% by mass or less, more preferably 0.5% by mass or less, in terms of suppression of bleeding of the weathering agent and economic efficiency. , 0.3 mass% or less is more preferable.
From the viewpoint of higher weather resistance, it is preferable to use the above antioxidant in combination with the above weather agent.

Among the antioxidants, it is preferable to use at least a phosphorus-based antioxidant in addition to the above-mentioned weathering agent in terms of higher weather resistance.
The antioxidant content in the adhesive composition of the present embodiment is preferably 0.02% by mass or more, more preferably 0.04% by mass or more, and 0.06% by mass from the viewpoint of high weather resistance. % Or more is more preferable.
In addition, the content of the weathering agent in the adhesive composition of the present embodiment is preferably 1.5% by mass or less, and more preferably 1.0% by mass or less from the viewpoint of suppressing bleeding of the antioxidant and economical efficiency. Is more preferred.

When preventing generation of static electricity, it is preferable to add an antistatic agent to the adhesive composition of the present embodiment.
Examples of the antistatic agent include a surfactant, a conductive resin, and a conductive filler.

A lubricant may be used in the adhesive composition of the present embodiment in order to improve the slipperiness of the product surface during and after the molding of the plastic.
Examples of the lubricant include stearamide, calcium stearate and the like.

  Examples of the filler include, but are not particularly limited to, mica, calcium carbonate, kaolin, talc, diatomaceous earth, urea resin, styrene beads, calcined clay, starch, and the like. These shapes are preferably spherical.

  Examples of the wax include, but are not particularly limited to, paraffin wax, microcrystalline wax, low molecular weight polyethylene wax and the like.

  The polymer other than the block copolymer used in the present embodiment is not particularly limited. For example, natural rubber, polyisoprene rubber, polybutadiene rubber, styrene butadiene rubber, olefin elastomers such as ethylene propylene copolymer; chloroprene rubber, Acrylic rubber, ethylene vinyl acetate copolymer and the like can be mentioned. These may be liquid or solid at room temperature.

  When high low-temperature coatability (low viscosity), creep performance (smaller value is better), high strength or high elongation, etc. are required, the ionomer in the adhesive composition is in a range of 5% by mass or less. May be used in

  In order to exhibit excellent adhesive strength to a hydrophilic porous substrate in a wet state, a liquid rubber having a carboxyl group and / or a carboxylic acid anhydride group in a molecule thereof in the adhesive composition and / or Alternatively, an acid-modified polyethylene acid-modified with a carboxylic anhydride is preferably added in a range of 0.5 to 8% by mass.

  When the high-temperature storage stability, the high elongation or the amount of the tackifying resin in the composition is reduced, a copolymer using an α-olefin or a propylene homopolymer may be used in an amount of 20% by mass in the adhesive composition. It is preferable to contain it in the following range. The melting point (condition: DSC measurement, 5 ° C./min) of these polymers is preferably 110 ° C. or less, more preferably 100 ° C. or less, and further preferably 60 ° C. to 90 ° C. These polymers may be resins or elastomers.

  Further, when elongation or the like is required, it is preferable to use an olefin-based elastomer in combination. Although it does not specifically limit as an olefin-type elastomer, For example, what has Tg at least -10 degreeC or less is preferable. From the viewpoint of creep performance, an olefin-based elastomer having a block is more preferable.

  When the surface smoothness or the like of the adhesive composition is particularly required, the wax component may be used in a range of 10% by mass or less based on the total amount of the adhesive composition.

  When a low melt viscosity at 130 ° C. or lower is required, at least one wax selected from paraffin wax, microcrystalline wax, and Fischer-Tropsch wax having a melting point of 50 ° C. to 110 ° C. is used in an amount of 2 to 10%. It is preferred that the content be contained by mass%. The content of these waxes is preferably 5 to 10% by mass based on the total amount of the adhesive composition. Further, the melting point of these waxes is preferably 65 ° C. or higher, more preferably 70 ° C. or higher, and further preferably 75 ° C. or higher. The softening point of the tackifier (b) used at this time is preferably 70 ° C. or higher, more preferably 80 ° C. or higher. At this time, the obtained adhesive composition has a G '(measurement condition: 25C, 10 rad / s) of preferably 1 Mpa or less, more preferably 7C or less.

  When used at a high temperature, as in JP-A-2015-28130, JP-A-2007-56119, JP-A-2014-534303 or JP-A-2015-30854, using an additive capable of radical crosslinking, epoxy crosslinking, or urethane crosslinking, It is preferable to improve heat resistance.

<< Production method of adhesive composition >>
<Method for producing partially hydrogenated block copolymer>
Partially hydrogenated block copolymer is, for example, in a hydrocarbon solvent, using a lithium compound as a polymerization initiator, a polymerization step of polymerizing at least a conjugated diene monomer and a vinyl aromatic monomer to obtain a block polymer. Performed, a hydrogenation step of adding hydrogen to part of the double bond in the conjugated diene monomer unit of the obtained block polymer, the solvent of the solution containing the resulting partially hydrogenated block copolymer It can be produced by performing a solvent removing step of removing the solvent.

  In the polymerization step, a polymer is obtained by polymerizing a monomer containing at least a conjugated diene monomer and a vinyl aromatic monomer in a hydrocarbon solvent using a lithium compound as a polymerization initiator.

  The hydrocarbon solvent used in the polymerization step is not particularly limited, and examples thereof include aliphatic hydrocarbons such as butane, pentane, hexane, isopentane, heptane, and octane; cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, and ethylcyclohexane. And alicyclic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene. These may be used alone or as a mixture of two or more.

  The lithium compound used as a polymerization initiator in the polymerization step is not particularly limited, and examples thereof include compounds in which one or more lithium atoms are bonded in a molecule such as an organic monolithium compound, an organic dilithium compound, and an organic polylithium compound. . Such an organic lithium compound is not particularly limited. For example, ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, hexamethylene dilithium, butadienyl Dilithium, isoprenyl dilithium and the like. These may be used alone or in combination of two or more.

  The conjugated diene monomer is not particularly limited. For example, 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3- Examples thereof include diolefins having a pair of conjugated double bonds such as pentadiene, 2-methyl-1,3-pentadiene, and 1,3-hexadiene. Of these, 1,3-butadiene and isoprene are preferred. From the viewpoint of mechanical strength, 1,3-butadiene is more preferable. These may be used alone or in combination of two or more.

  Examples of the vinyl aromatic monomer include, but are not particularly limited to, styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N, N-dimethyl-p-aminoethylstyrene, And vinyl aromatic compounds such as N, N-diethyl-p-aminoethylstyrene. Of these, styrene is preferred from the viewpoint of economy. These may be used alone or in combination of two or more.

  In addition to the conjugated diene monomer and the vinyl aromatic monomer, other monomers copolymerizable with the conjugated diene monomer and the vinyl aromatic monomer can also be used.

  In the polymerization step, the polymerization rate is adjusted, the microstructure (ratio of cis, trans, and vinyl) of the polymerized conjugated diene monomer unit is adjusted, and the reaction ratio between the conjugated diene monomer and the vinyl aromatic monomer is adjusted. A predetermined polar compound or randomizing agent can be used for the purpose of, for example, adjusting the concentration of the compound.

  The polar compound and the randomizing agent are not particularly limited. For example, ethers such as tetrahydrofuran, diethylene glycol dimethyl ether and diethylene glycol dibutyl ether; amines such as triethylamine and tetramethylethylene diamine; thioethers, phosphines, phosphoramides and alkylbenzene sulfones And alkoxides of potassium and sodium.

  The polymerization method carried out in the polymerization step of the block copolymer is not particularly limited, and a known method can be applied. Known methods include, for example, JP-B-36-19286, JP-B-43-17979, JP-B-46-32415, JP-B-49-36957, JP-B-48-2423, and JP-B-48-2423. 48-4106, JP-B-56-28925, JP-A-59-166518, JP-A-60-186577, and the like.

  The block copolymer may be coupled using a coupling agent.

  The coupling agent is not particularly limited, but any bifunctional or higher coupling agent can be used. The bifunctional coupling agent is not particularly limited. For example, bifunctional halogenated silanes such as dichlorosilane, monomethyldichlorosilane, and dimethyldichlorosilane; diphenyldimethoxysilane, diphenyldiethoxysilane, dimethyldimethoxysilane, and dimethyldichlorosilane Bifunctional alkoxysilanes such as ethoxysilane; difunctional halogenated alkanes such as dichloroethane, dibromoethane, methylene chloride, dibromomethane; dichlorotin, monomethyldichlorotin, dimethyldichlorotin, monoethyldichlorotin, diethyldichlorotin, monobutyl Difunctional tin halides such as dichlorotin and dibutyldichlorotin; dibromobenzene, benzoic acid, CO, 2-chloropropene and the like.

  The trifunctional coupling agent is not particularly limited. For example, trifunctional halogenated alkanes such as trichloroethane and trichloropropane; trifunctional halogenated silanes such as methyltrichlorosilane and ethyltrichlorosilane; methyltrimethoxysilane; Trifunctional alkoxysilanes such as phenyltrimethoxysilane and phenyltriethoxysilane; and the like.

  The tetrafunctional coupling agent is not particularly restricted but includes, for example, tetrafunctional halogenated alkanes such as carbon tetrachloride, carbon tetrabromide and tetrachloroethane; tetrafunctional halogenated silanes such as tetrachlorosilane and tetrabromosilane Tetrafunctional alkoxysilanes such as tetramethoxysilane and tetraethoxysilane; tetrafunctional tin halides such as tetrachlorotin and tetrabromotin; and the like.

  The coupling agent having five or more functional groups is not particularly limited, and examples thereof include polyhalogens such as 1,1,1,2,2-pentachloroethane, perchloroethane, pentachlorobenzene, perchlorobenzene, octabromodiphenyl ether, and decabromodiphenyl ether. Hydrocarbon compounds. In addition, polyvinyl compounds such as epoxidized soybean oil, 2- to 6-functional epoxy group-containing compounds, carboxylic acid esters, and divinylbenzene can also be used. One type of coupling agent may be used alone, or two or more types may be used in combination.

  After the polymerization step, it is preferable to perform a deactivation step of deactivating the active terminal of the block copolymer. By reacting a compound having active hydrogen with an active terminal, the active terminal of the polymer can be deactivated. The compound having active hydrogen is not particularly limited, but alcohol, water, and the like can be mentioned from the viewpoint of economy.

  In the hydrogenation step, hydrogen is added to a part of the double bond in the conjugated diene monomer unit of the block copolymer obtained in the polymerization step. The catalyst used for the hydrogenation reaction is not particularly limited. For example, a supported heterogeneous metal in which a metal such as Ni, Pt, Pd, and Ru is supported on a carrier such as carbon, silica, alumina, and diatomaceous earth. -Based catalysts; so-called Ziegler-type catalysts using an organic salt or acetylacetone salt such as Ni, Co, Fe, Cr and the like and a reducing agent such as organic Al; so-called organic complex catalysts such as organometallic compounds such as Ru and Rh; and titanocene A homogeneous catalyst using organic Li, organic Al, organic Mg, or the like as a reducing agent for the compound may be used. Among them, a homogeneous catalyst system using an organic Li, an organic Al, an organic Mg or the like as a reducing agent for the titanocene compound is preferable from the viewpoints of economy, coloring property of the polymer and adhesive strength.

  The method of the hydrogenation reaction is not particularly limited. For example, the methods described in JP-B-42-8704, JP-B-43-6636, and preferably JP-B-63-4841 and JP-B-63 And a method described in JP-A-5401. Specifically, a hydrogenation reaction is carried out in an inert solvent in the presence of a hydrogenation catalyst to obtain a partially hydrogenated block copolymer solution. The hydrogenation reaction is preferably performed after the deactivation step from the viewpoint of high hydrogenation activity.

  In the hydrogenation step, the conjugate bond of the vinyl aromatic monomer unit may be hydrogenated. The upper limit of the hydrogenation rate of conjugated bonds in all vinyl aromatic monomer units may be, for example, 30 mol% or less, 10 mol% or less, or 3 mol% or less based on the total amount of unsaturated groups in the aromatic. The lower limit may be, for example, 0.1 mol% or more, or may be 0 mol%. When the hydrogenation rate of the conjugate bond in the whole vinyl aromatic monomer is within the above range, the holding power and the adhesiveness tend to be further improved.

  It is preferable to add a functional group to the obtained partially hydrogenated block copolymer by using a compound having a functional group as an initiator, a monomer, a coupling agent, or a terminator.

  As the initiator containing a functional group, an initiator containing a nitrogen-containing group is preferable, and dioctylaminolithium, di-2-ethylhexylaminolithium, ethylbenzylaminolithium, (3- (dibutylamino) -propyl) lithium, And peridinolithium.

  Examples of the monomer containing a functional group include compounds containing a hydroxyl group, an acid anhydride group, an epoxy group, an amino group, an amide group, a silanol group, and an alkoxysilane group as the monomers used for the above-mentioned polymerization. Among these, a monomer containing a nitrogen-containing group is preferable. For example, N, N-dimethylvinylbenzylamine, N, N-diethylvinylbenzylamine, N, N-dipropylvinylbenzylamine, N, N-dibutylvinylbenzyl Amine, N, N-diphenylvinylbenzylamine, 2-dimethylaminoethylstyrene, 2-diethylaminoethylstyrene, 2-bis (trimethylsilyl) aminoethylstyrene, 1- (4-N, N-dimethylaminophenyl) -1- Phenylethylene, N, N-dimethyl-2- (4-vinylbenzyloxy) ethylamine, 4- (2-pyrrolidinoethyl) styrene, 4- (2-piperidinoethyl) styrene, 4- (2-hexamethyleneiminoethyl) Styrene, 4- (2-morpholinoethyl) styrene, 4- (2- Ajinoechiru) styrene, 4- (2-N-methyl-piperazino-ethyl) styrene, 1 - ((4-vinyl) methyl) pyrrolidine, and 1- (4-vinyl benzyloxycarbonyl) pyrrolidine, and the like.

  Examples of the coupling agent and the terminator containing a functional group include, among the aforementioned coupling agents, compounds containing a hydroxyl group, an acid anhydride group, an epoxy group, an amino group, an amide group, a silanol group, and an alkoxysilane group.

  Among these, a coupling agent containing a nitrogen-containing group or an oxygen-containing group is preferable, for example, tetraglycidyl metaxylenediamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, tetraglycidyl-p-phenylenediamine, tetraglycidyldiaminodiphenylmethane, Diglycidylaniline, γ-caprolactone, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriphenoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ- Glycidoxypropyldiethylethoxysilane, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N, N′-dimethylpropyleneurea, N-methylpyrrolidone and the like It is below.

  In the solvent removing step, the solvent of the solution containing the partially hydrogenated block copolymer is removed. The method of desolvation is not particularly limited, and examples thereof include a steam stripping method and a direct desolvation method.

  The residual solvent amount in the partially hydrogenated block copolymer obtained by the solvent removing step is preferably as small as possible, for example, 2% by mass or less, 0.5% by mass or less, 0.2% by mass or less, 0.05% by mass. % Or less, or 0.01% by mass or less, more preferably 0% by mass. From the viewpoint of economy, the amount of the residual solvent in the partially hydrogenated block copolymer is usually in the range of 0.01% by mass to 0.1% by mass.

  It is preferable to add an antioxidant to the partially hydrogenated block copolymer from the viewpoint of heat aging resistance and suppression of gelation of the partially hydrogenated block copolymer. Examples of the antioxidant include a phenolic antioxidant such as a radical scavenger, a phosphorus antioxidant such as a peroxide decomposer, and a sulfur antioxidant. Further, an antioxidant having both properties may be used. These may be used alone or in combination of two or more. Among them, a phenolic antioxidant is preferable from the viewpoint of heat aging resistance and suppression of gelation of the partially hydrogenated block copolymer.

  From the viewpoint of preventing coloring of the partially hydrogenated block copolymer and improving mechanical strength, before the desolvation step, a deashing step of removing metals in a solution containing the partially hydrogenated block copolymer, A neutralization step for adjusting the pH of the solution containing the polymer may be performed. For example, an acid and / or a carbon dioxide gas may be added.

<Production method of adhesive tape / label>
The method for producing the adhesive composition of the present embodiment is not particularly limited, and two or more partially hydrogenated block copolymers having different vinyl aromatic monomer unit contents, and a tackifying resin, and If necessary, while heating other components such as block copolymers and oils with a known mixer, kneader, single-screw extruder, twin-screw extruder, Banbury mixer, etc., at a predetermined compounding ratio. There is a method of mixing uniformly.

The adhesive composition of the present embodiment is preferably used by being laminated at least on a substrate. There is no limitation on the type of the base material. For example, a non-thermoplastic base material such as a film made of a thermoplastic resin, paper, metal, woven fabric, or nonwoven fabric can be used. A release agent may be added to the material of the base material. Examples of the release agent include a long-chain alkyl-based release agent and a silicon-based release agent.
Further, when higher weather resistance (low change in adhesive strength after UV irradiation) is required, it is more preferable to use a substrate having a low ultraviolet transmittance, and the transmittance is more preferably 1% or less.

  The method for applying the adhesive composition of the present embodiment to a substrate is not particularly limited, and examples thereof include a T-die coating method, a roll coating method, a multi-bead coating method, and a spray coating method. . The extrusion coating (hot melt coating) method or the spread coating method may be used, but the adhesive composition of the present embodiment is suitable for the extrusion coating method having high heat aging resistance and high economic efficiency. .

《Adhesive tape》
The adhesive composition of the present embodiment includes various adhesive tapes / labels, pressure-sensitive thin plates, pressure-sensitive sheets, surface protection sheets / films, back paste for fixing various lightweight plastic molded products, back for carpet fixing. It can be suitably used as a glue, a back glue for fixing a tile, an adhesive, a sealing agent, a masking agent at the time of repainting work, a sanitary article, and the like. Particularly, an adhesive tape is preferable.

  When the adhesive composition of the present embodiment is used as a masking material at the time of repainting work, it is preferable to use a metal foil such as an aluminum foil as a base material from the viewpoint of suppressing corrosion by a chemical solution. .

  When the adhesive composition of the present embodiment is used for a sanitary article, a nonwoven fabric is used as a base material, and a stretchable laminate is obtained by laminating an adhesive composition layer and an elastomer layer on the nonwoven fabric on this basis. Is also good. In order to obtain an excellent fit, it is preferable that the elastic laminate has a residual strength at 100% elongation of 80% or more and a residual strength at 50% elongation of 70% or more.

  Hereinafter, the present invention will be described specifically with reference to specific examples and comparative examples, but the present invention is not limited to these.

(Production Example of Block Copolymer)
[Production of hydrogenation catalyst]
In a reaction vessel purged with nitrogen, put 1 L of dried and purified cyclohexane, add 100 mmol of bis (cyclopentadienyl) titanium dichloride, add an n-hexane solution containing 200 mmol of trimethylaluminum with sufficient stirring, By reacting at room temperature for about 3 days, a hydrogenation catalyst was produced.

[Production of partially hydrogenated block copolymer P1]
A predetermined amount of cyclohexane was charged into a jacketed tank reactor, and the temperature in the reactor was adjusted to 60 ° C. Thereafter, n-butyllithium was added from the bottom of the reactor so that n-butyllithium was 0.11 part by mass with respect to 100 parts by mass of all monomers (total amount of butadiene monomer and styrene monomer charged into the reactor). Was added. Furthermore, a cyclohexane solution of N, N, N ′, N′-tetramethylethylenediamine was added so that N, N, N ′, N′-tetramethylethylenediamine would be 0.35 mol per 1 mol of n-butyllithium. Was added. Thereafter, as a first-step polymerization reaction, a cyclohexane solution (styrene monomer concentration: 15% by mass) containing 15 parts by mass of a styrene monomer was supplied over about 10 minutes. While feeding the styrene monomer, the temperature in the reactor was adjusted to 60 ° C. After stopping the supply of the styrene monomer, the reaction was continued for 15 minutes while adjusting the temperature in the reactor to 70 ° C.

  Next, as a polymerization reaction in the second step, a cyclohexane solution (butadiene monomer concentration: 15% by mass) containing 85 parts by mass of a butadiene monomer was continuously supplied to the reactor at a constant rate over 50 minutes. During the supply of the butadiene monomer, the temperature in the reactor was adjusted to 70 ° C. After stopping the supply of the butadiene monomer, the reaction was continued for 10 minutes while adjusting the temperature in the reactor to 70 ° C. to obtain a polystyrene-polybutadiene block copolymer.

  In the obtained polystyrene-polybutadiene block copolymer, the content of the vinyl aromatic monomer unit and the content of the block mainly composed of the vinyl aromatic monomer unit (polystyrene block) were both 15% by mass. The vinyl bond amount (vinyl content in butadiene) of the conjugated diene monomer unit was 34 mol%, and the weight average molecular weight (hereinafter, also simply referred to as “Mw”) was 90000.

  A part of the obtained polystyrene-polybutadiene block copolymer was extracted, and tetraethoxysilane was added as a coupling agent so that the molar ratio to the total mol of n-butyllithium was 0.1, and the coupling reaction was performed for 10 minutes. Then, a coupling polymer was obtained.

  Thereafter, using the hydrogenation catalyst, the obtained coupling polymer was hydrogenated at 80 ° C. to obtain a partially hydrogenated block copolymer. After the completion of the reaction, 0.25 parts by mass of a stabilizer (octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) was added to 100 parts by mass of the partially hydrogenated block copolymer. Thus, a partially hydrogenated block copolymer P1 was obtained. The hydrogenation rate of the partially hydrogenated block copolymer P1 was 40 mol%, and the MFR (200 ° C., 5 kgf) was 2.0 g / 10 minutes.

The structure and composition of the partially hydrogenated block copolymer P1 are as follows:
(S-B): 65% by mass, Mw 90000
(SB) 2-X: 4% by mass, Mw 180000
(S-B) 3-X: 8% by mass, Mw 270000
(S-B) 4-X: 23% by mass, Mw 360000
(In the formula, S represents a styrene block, B represents a butadiene block, and X represents a residue of a coupling agent. The same applies hereinafter.)

[Production of partially hydrogenated block copolymer P2]
After the coupling reaction, the partially hydrogenated block copolymer P1 was added except that dimethylimidazolidinone was added so that dimethylimidazolidinone was 0.6 mol per 1 mol of n-butyllithium added in the polymerization reaction. A partially hydrogenated block copolymer P2 was produced in the same manner as described above.

  The hydrogenation rate of the partially hydrogenated block copolymer P2 was 40 mol%, and the MFR (200 ° C., 5 kgf) was 2.0 g / 10 minutes.

The structure and composition of the partially hydrogenated block copolymer P2 are as follows:
(S-B): 65% by mass, Mw 90000
(SB) 2-X: 4% by mass, Mw 180000
(S-B) 3-X: 8% by mass, Mw 270000
(S-B) 4-X: 23% by mass, Mw 360000
And the dimethylimidazolidinone was added to 80 mol% of (SB).

[Production of partially hydrogenated block copolymer P3]
Except for changing the amounts of n-butyllithium, N, N, N ', N'-tetramethylethylenediamine, butadiene monomer and styrene monomer in the production of the partially hydrogenated block copolymer P1, the partially hydrogenated block A polystyrene-polybutadiene block copolymer was produced in the same manner as in the production of the copolymer P1.

  In the obtained polystyrene-polybutadiene block copolymer, the content of the vinyl aromatic monomer unit and the content of the block mainly composed of the vinyl aromatic monomer unit (polystyrene block) were both 30% by mass. The vinyl bond amount (vinyl content in butadiene) of the conjugated diene monomer unit was 40 mol%, and Mw was 70,000.

    The obtained polystyrene-polybutadiene block copolymer was subjected to a coupling reaction and a hydrogenation reaction in the same manner as in the production of the partially hydrogenated block copolymer P1. The hydrogenation rate of the partially hydrogenated block copolymer P3 was 43 mol%, and the MFR (200 ° C., 5 kgf) was 20 g / 10 minutes.

The structure and composition of the partially hydrogenated block copolymer P3 are as follows:
(S-B): 70% by mass, Mw 70000
(S-B) 2-X: 30% by mass, Mw 140000
Met.

[Production of partially hydrogenated block copolymer P4]
A polystyrene-polybutadiene block copolymer was produced in the same manner as in the production of the partially hydrogenated block copolymer P1 except that the amount of the butadiene monomer and the amount of styrene were changed.

  In the obtained polystyrene-polybutadiene block copolymer, the content of the vinyl aromatic monomer unit and the content of the block mainly composed of the vinyl aromatic monomer unit (polystyrene block) were both 23% by mass. The vinyl bond amount (vinyl content in butadiene) of the conjugated diene monomer unit was 34 mol%, and Mw was 90000.

  The obtained polystyrene-polybutadiene block copolymer was subjected to a coupling reaction and a hydrogenation reaction in the same manner as in the production of the partially hydrogenated block copolymer P1. The hydrogenation rate of the partially hydrogenated block copolymer P4 was 40 mol%, and the MFR (200 ° C., 5 kgf) was 2.0 g / 10 minutes.

The structure and composition of the partially hydrogenated block copolymer P4 are as follows:
(S-B): 65% by mass, Mw 90000
(SB) 2-X: 4% by mass, Mw 180000
(S-B) 3-X: 8% by mass, Mw 270000
(S-B) 4-X: 23% by mass, Mw 360000
Met.

[Production of Completely Hydrogenated Block Copolymer P5]
A predetermined amount of cyclohexane was charged into a jacketed tank reactor, and the temperature in the reactor was adjusted to 60 ° C. Thereafter, n-butyllithium was added from the bottom of the reactor so that n-butyllithium was 0.14 parts by mass with respect to 100 parts by mass of all monomers (total amount of butadiene monomer and styrene monomer charged into the reactor). Was added. Further, a cyclohexane solution of N, N, N ', N'-tetramethylethylenediamine was added so that N, N, N', N'-tetramethylethylenediamine was 0.40 mol per 1 mol of n-butyllithium. Was added. Thereafter, as a first-step polymerization reaction, a cyclohexane solution (styrene monomer concentration: 15% by mass) containing 9 parts by mass of a styrene monomer was supplied over about 10 minutes. While feeding the styrene monomer, the temperature in the reactor was adjusted to 60 ° C. After stopping the supply of the styrene monomer, the reaction was continued for 15 minutes while adjusting the temperature in the reactor to 70 ° C.

  Next, as a polymerization reaction in the second step, a cyclohexane solution (butadiene monomer concentration: 15% by mass) containing 82 parts by mass of a butadiene monomer was continuously supplied to the reactor at a constant rate over 70 minutes. During the supply of the butadiene monomer, the temperature in the reactor was adjusted to 70 ° C. After stopping the supply of the butadiene monomer, the reaction was continued for 10 minutes while adjusting the temperature in the reactor to 70 ° C.

  Next, as a polymerization reaction in a third step, a cyclohexane solution (styrene monomer concentration: 15% by mass) containing 9 parts by mass of a styrene monomer was continuously supplied to the reactor at a constant rate over 10 minutes. During the supply of the styrene monomer, the temperature in the reactor was adjusted to 70 ° C. After the supply of the styrene monomer was stopped, the reaction was continued for 10 minutes while adjusting the temperature in the reactor to 70 ° C. to obtain a polystyrene-polybutadiene-polystyrene block copolymer.

  In the obtained polystyrene-polybutadiene-polystyrene block copolymer, the content of the vinyl aromatic monomer unit and the content of the block (polystyrene block) mainly composed of the vinyl aromatic monomer unit were both 18% by mass. The vinyl bond amount (vinyl content in butadiene) of the conjugated diene monomer unit was 41 mol%, and Mw was 60000.

  Thereafter, using the hydrogenation catalyst, the obtained polystyrene-polybutadiene-polystyrene block polymer was hydrogenated at 80 ° C. to obtain a completely hydrogenated block copolymer. After the completion of the reaction, 0.25 parts by mass of a stabilizer (octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) was added to 100 parts by mass of the partially hydrogenated block copolymer. Thus, a completely hydrogenated block copolymer P5 was obtained. The hydrogenation rate of the completely hydrogenated block copolymer P5 was 99 mol%, and the MFR (200 ° C., 5 kgf) was 3.0 g / 10 minutes.

[Production of non-hydrogenated block copolymer P6]
A predetermined amount of cyclohexane was charged into a jacketed tank reactor, and the temperature in the reactor was adjusted to 60 ° C. Thereafter, n-butyllithium was added from the bottom of the reactor so that n-butyllithium was 0.19 parts by mass with respect to 100 parts by mass of all monomers (total amount of butadiene monomer and styrene monomer charged into the reactor). Was added. Further, a cyclohexane solution of N, N, N ', N'-tetramethylethylenediamine was added so that N, N, N', N'-tetramethylethylenediamine was 0.03 mol per 1 mol of n-butyllithium. Was added. Thereafter, as a polymerization reaction in the first step, a cyclohexane solution (styrene monomer concentration: 15% by mass) containing 38 parts by mass of a styrene monomer was supplied over about 15 minutes. While feeding the styrene monomer, the temperature in the reactor was adjusted to 60 ° C. After the supply of the styrene monomer was stopped, the reaction was continued for 20 minutes while adjusting the temperature in the reactor to 70 ° C.

  Next, as a polymerization reaction in the second step, a cyclohexane solution containing butadiene monomer (62 parts by mass) (butadiene monomer concentration: 15% by mass) was continuously supplied to the reactor at a constant rate over 50 minutes. During the supply of the butadiene monomer, the temperature in the reactor was adjusted to 70 ° C. After stopping the supply of the butadiene monomer, the reaction was continued for 10 minutes while adjusting the temperature in the reactor to 70 ° C. to obtain a polystyrene-polybutadiene block copolymer.

  In the obtained polystyrene-polybutadiene block copolymer, the content of the vinyl aromatic monomer unit and the content of the block mainly composed of the vinyl aromatic monomer unit (polystyrene block) were both 38% by mass. The vinyl bond amount (vinyl content in butadiene) of the conjugated diene monomer unit was 13 mol%, and Mw was 50,000.

  A part of the polystyrene-polybutadiene block copolymer was extracted, tetraethoxysilane was added as a coupling agent so that the molar ratio to the total mol of n-butyllithium was 0.1, and the coupling reaction was performed for 15 minutes. A hydrogenated block polymer was obtained.

  After completion of the coupling reaction, a stabilizer (octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) was added to 100 parts by mass of the obtained non-hydrogenated block copolymer. 25 parts by mass were added to obtain a non-hydrogenated block copolymer P6. The non-hydrogenated block copolymer P6 had a hydrogenation rate of 0 mol% and an MFR (200 ° C., 5 kgf) of 100 g / 10 min.

The structure and composition of the non-hydrogenated block copolymer P6 are as follows:
(S-B): 73% by mass, Mw 50,000
(SB) 2-X: 2% by mass, Mw 100000
(S-B) 3-X: 15% by mass, Mw 150000
(S-B) 4-X: 10% by mass, Mw200000
Met.

[Other materials]
In addition to the above partially hydrogenated block copolymers P1 to P4, fully hydrogenated block copolymer P5, and non-hydrogenated block copolymer P6, the following block polymers (SIS-a) and (SIS-b), The imparting agents (b-1) and (b-2), the oils (c-1) and (c-2), and the antioxidant were used.

Block polymer (SIS-a): D1161 (manufactured by Kraton, polystyrene block content 15% by mass, diblock content 19% by mass)
Block polymer (SIS-b): Quintac3450 (manufactured by Zeon Corporation, polystyrene block content 19% by mass, diblock content 30% by mass)
Tackifier (b-1): Quintone R100 (manufactured by Nippon Zeon Co., Ltd., 99% or more of polymer of C4-C5 hydrocarbon fraction, softening point 96 ° C, aliphatic tackifier)
Tackifier (b-2): Alcon M100 (Arakawa Chemical Industries, softening point 100 ° C, partially hydrogenated aromatic tackifier)
Tackifier (b-3): Clearon P105 (manufactured by Yasuhara Chemical Co., Ltd., softening point 105 ° C, completely hydrogenated terpene resin)

Oil (c-1): Diana Process Oil PW-90 (Idemitsu Kosan Co., Ltd., paraffin oil)
Oil (c-2): Diana Process Oil NS-90S (Naphthenic oil manufactured by Idemitsu Kosan Co., Ltd.)
Antioxidant: Irganox 1010 (BASF, phenolic antioxidant)
Antioxidant: Irgafos168 (BASF, phosphorus-based antioxidant)
Weathering agent: TINUVIN P (manufactured by BASF, benzotriazole-based ultraviolet absorber, molecular weight 225, melting point 128-132 ° C)
Weathering agent: TINUVIN 326 (manufactured by BASF, benzotriazole-based ultraviolet absorber, melting point 138-141 ° C)
Weathering agent: ADK STAB LA-63 (ADEKA, HALS, molecular weight about 2,000, melting point 85-105 ° C)
Weathering agent: TINUVIN 622 (manufactured by BASF, HALS, molecular weight about 3,500)
Weathering agent: Syasorb UV3346 (manufactured by Sun Chemical Co., Ltd., HALS, molecular weight about 1,600, melting point 110-130 ° C)

(Production Example of Adhesive Composition)
In the composition shown in Table 1, the block copolymers P1 to P6, the tackifier, the oil, and the additives were mixed in a kneader while heating to 150 ° C., and Examples 1 to 14 and Comparative Examples Examples 1 to 4 prepared adhesive compositions.

[Production example of adhesive tape]
The melted adhesive composition was cooled to room temperature, dissolved in toluene, and coated with an applicator on a transparent polyethylene terephthalate (PET) film having a thickness of 50 μm as a substrate. Thereafter, toluene was completely evaporated at room temperature for 30 minutes and in a 70 ° C. oven for 7 minutes to prepare an adhesive tape having a transparent PET film having a thickness of 30 μm as a substrate.

(Measurement and evaluation method)
The method for specifying the structures and compositions of the partially hydrogenated block copolymers P1 to P4, the completely hydrogenated block copolymer P5, and the non-hydrogenated block copolymer P6, and the methods of Examples 1 to 21 and Comparative Examples 1 to 4 The evaluation method of the pressure-sensitive adhesive composition is described below.

(Measurement of vinyl content and hydrogenation rate of block copolymer)
The vinyl content in partially hydrogenated, fully hydrogenated and non-hydrogenated block copolymers, and the hydrogenation rate of unsaturated groups in conjugated dienes in partially hydrogenated and fully hydrogenated block copolymers are determined by nuclear magnetic properties. It was measured under the following conditions by resonance spectrum analysis (NMR).

  By adding a large amount of methanol to the reaction solution containing the block copolymer before the hydrogenation reaction, the block copolymer was precipitated and recovered. Next, this block copolymer was extracted with acetone, and the block copolymer was dried under vacuum. Using this as a sample for 1H-NMR measurement, the vinyl content was measured.

  A large amount of methanol is added to the reaction solution containing the partially hydrogenated (or completely hydrogenated) block copolymer after the hydrogenation reaction to precipitate the partially hydrogenated (or completely hydrogenated) block copolymer. Collected. Next, the partially hydrogenated (or completely hydrogenated) block copolymer was extracted with acetone, and the partially hydrogenated block copolymer was dried under vacuum. Using this as a sample for 1H-NMR measurement, the hydrogenation rate was measured.

The conditions for 1H-NMR measurement are described below.
Measuring equipment: JNM-LA400 (manufactured by JEOL)
Solvent: deuterated chloroform Measurement sample: sampled before and after hydrogenation of polymer Sample concentration: 50 mg / mL
Observation frequency: 400 MHz
Chemical shift standard: TMS (tetramethylsilane)
Pulse delay: 2.904 seconds Number of scans: 64 Pulse width: 45 °
Measurement temperature: 26 ° C

(Measurement of the content of vinyl aromatic monomer units (styrene) in the block copolymer)
A certain amount of the block copolymer composition is dissolved in chloroform, and the absorption wavelength (attributable to the vinyl aromatic compound component (styrene) in the solution is measured using an ultraviolet spectrophotometer (manufactured by Shimadzu Corporation, UV-2450). 262 nm). From the obtained peak intensity, the content of the vinyl aromatic monomer unit (styrene) was calculated using a calibration curve.

(Measurement of content of polymer block mainly composed of vinyl aromatic monomer units in block copolymer)
I. M. Kolthoff, et al. , J. et al. Polym. Sci. , 1946, Vol. 1, p. 429, the content of a polymer block mainly composed of vinyl aromatic monomer units was measured using the following polymer decomposition solution.
Measurement sample: Extracted product before hydrogenation of the block copolymer Polymer decomposition solution: A solution in which 0.1 g of osmium tetroxide was dissolved in 125 mL of tertiary butanol

(Measurement of weight average molecular weight (Mw) of block copolymer)
The weight average molecular weight (Mw) of the block copolymer was determined based on the molecular weight of the peak in the chromatogram using a calibration curve (prepared using the peak molecular weight of standard polystyrene) obtained from measurement of commercially available standard polystyrene. I asked. The measurement software used was HLC-8320 EcoSEC collection, and the analysis software used was HLC-8320 analysis. The measurement conditions are shown below.
GPC; HLC-8320GPC (Tosoh Corporation)
Detector; RI
Detection sensitivity: 3 mV / min Sampling pitch: 600 msec
Column: TSKgel superHZM-N (6 mm ID × 15 cm) 4 (manufactured by Tosoh Corporation)
Solvent; THF
Flow rate: 0.6 mm / min Concentration: 0.5 mg / mL
Column temperature; 40 ° C
Injection volume: 20 μL

(Evaluation of 180 ° C. melt viscosity of adhesive composition)
The melt viscosity of the adhesive composition was measured at a temperature of 180 ° C. using a Brookfield viscometer (DV-III, manufactured by Brookfield).

(Adhesive properties of adhesive composition: evaluation of initial adhesive strength)
Method 1 for measuring peel strength according to JIS Z0237 1: Measured according to the method for measuring 180 ° peel strength of a test plate. First, the adhesive tape manufactured as described above was cut into a width of 25 mm to prepare a 25 mm-wide adhesive tape sample. The adhesive tape sample was attached to a stainless steel plate, and the 180 ° peeling force was measured at a peeling speed of 300 mm / min. Based on the obtained peeling force, the adhesive strength of the adhesive composition was evaluated according to the following criteria. The evaluation was ◎, △, Δ, and × from the best order. If it is Δ or more, it can be used as a pressure-sensitive adhesive composition without practical problems.
Peeling force (N / 10 mm) 9 or more: ◎
8 or more and less than 9: ○
6 or more and less than 8:
Less than 6: ×

(Adhesive properties of adhesive composition: Evaluation of adhesive strength after immersion in warm water)
Method 1 for measuring peel strength according to JIS Z0237 1: Measured according to the method for measuring 180 ° peel strength of a test plate. The adhesive tape sample having a width of 25 mm prepared as described above was attached to a stainless steel plate, and then immersed in warm water of 40 ° C. for 1 hour, and peeled at a speed of 300 mm / min. ° Peeling force was measured. Based on the obtained peeling force, the adhesive strength of the adhesive composition was evaluated according to the following criteria. The evaluation was ◎, △, Δ, and × from the best order. If it is Δ or more, it can be used as a pressure-sensitive adhesive composition without practical problems.
Peeling force (N / 10mm) 8 or more: ◎
7 or more and less than 8: ○
5 or more and less than 7:
Less than 5: ×

(Adhesive property of adhesive composition: Evaluation of adhesive strength (change rate) after UV irradiation)
As an index of light resistance, using a sunshine weather meter (Sunshine Super Long Weather Meter CWEL-SUN-HCH-B type / manufactured by Suga Test Instruments Co., Ltd.), adhesion before light irradiation (initial value) and adhesion after light irradiation The force was measured. The adhesive tape sample having a width of 25 mm prepared as described above was attached to a SUS plate (SUS304). Thirty minutes later, the adhesive tape was peeled off from the SUS plate at a peeling speed of 300 mm / min without light irradiation, and the 180 ° peeling force before UV irradiation was measured.

  In addition, the prepared adhesive tape sample having a width of 25 mm was adhered to a SUS plate (SUS304), and the black adhesive sheet was heated from the base (transparent PET film) side at a temperature of 63 ° C. and no rain. For 72 hours. Thereafter, the adhesive tape was peeled off from the SUS plate at a peeling speed of 300 mm / min, and the 180 ° peeling force after UV irradiation was measured.

The rate of change of the 180 ° peel force before UV irradiation and the rate of change of the 180 ° peel force after 72 hours of UV irradiation were defined as the adhesive force change rate. The obtained adhesive force change rate was evaluated according to the following evaluation criteria. The evaluation was ◎, △, Δ, and × from the best order.
Adhesive force change rate = {(peeling force after UV irradiation)-(peeling force before UV irradiation)} (peeling force before UV irradiation) × 100
Adhesion force change rate is less than ± 30%: ◎
Adhesive strength change rate is ± 30% or more and less than 40%: ○
Adhesive strength change rate is ± 40 or more and less than 50%: △
Adhesive force change rate is ± 50% or more: ×

(Evaluation of probe tack of adhesive composition)
The adhesive tape produced as described above was cut to prepare an adhesive tape sample having a length of 30 mm and a width of 30 mm. The prepared adhesive tape sample was stuck on a 10 g load (cylindrical) top surface of a probe tack tester (NTS-4800 / manufactured by Tester Sangyo Co., Ltd.) so that the adhesive surface faced downward. A cylinder (made of SUS) having a diameter of 5 mmφ was adhered from below to the adhesive surface for 1 second in a floating state. Thereafter, the peeling force when the cylinder was peeled downward was measured. The bonding and peeling speed was 10 mm / sec. The probe tack of the adhesive composition was evaluated according to the following criteria. The evaluation was ◎, △, Δ, and × from the best order. If it is Δ or more, it can be used as a pressure-sensitive adhesive composition without practical problems.
Peeling force measured value (N / 5mmφ) 2.0 or more: ◎
1.7 or more and less than 2.0: ○
1.4 or more and less than 1.7: △
Less than 1.4: ×

(Evaluation of adhesive holding power of adhesive composition)
The adhesive tape produced as described above was cut to prepare an adhesive tape sample having a length of 25 mm and a width of 15 mm. The adhesive tape sample was stuck on a stainless steel plate, the stainless steel plate was made vertical, and a load of 1 kg was applied vertically downward at 50 ° C. to measure the time until the adhesive tape came off. The adhesive holding power of the adhesive composition was evaluated according to the following criteria. The evaluations were evaluated as ○, Δ, and × in descending order. If it is Δ or more, it can be used as a pressure-sensitive adhesive composition without practical problems.
Adhesive holding power (min) 50 minutes or more: ○
10 minutes or more and less than 50 minutes:
Less than 10 minutes: ×

  Although the adhesive composition of the present invention is not limited to the following, various pressure-sensitive adhesive tapes / labels, pressure-sensitive thin plates, pressure-sensitive sheets, surface protection sheets / films, back paste for fixing various lightweight plastic molded products, carpet fixing It can be used as a back glue for tiles, a back glue for fixing tiles, an adhesive, a sealing agent, a masking agent at the time of repainting work, and a sanitary article.

Claims (7)

A tacky adhesive composition containing 20 parts by mass to 400 parts by mass of a tackifying resin, based on 100 parts by mass of a block copolymer having a polymer block mainly composed of vinyl aromatic monomer units,
The block copolymer has a different vinyl aromatic monomer unit content, and the structure before hydrogenation has two or more types of moieties containing any of the following formulas (i) to (vi). Contains a hydrogenated block copolymer,
At least one kind of the partially hydrogenated block copolymer is a partially hydrogenated block copolymer (a) having a vinyl aromatic monomer unit content of 10% by mass to 25% by mass, and at least one other type. Is a partially hydrogenated block copolymer (b) having a vinyl aromatic monomer unit content exceeding 25% by mass.
(AB) _n ... (i)
B- (AB) _n (ii)
A- (BA) _n (iii)
A- (BA) _n -X (iv)
[(AB) _k ] _m -X (v)
[(AB) _k -A] _m -X (vi)
(In the formulas (i) to (vi), A represents a polymer block mainly composed of a vinyl aromatic monomer unit, B represents a polymer block mainly composed of a conjugated diene monomer unit, X represents a residue of a coupling agent, n represents the formula (i) represents an integer from 2 to 5, in formula (ii) ~ (vi), m, n and k are an integer of 1 or more Represents.)   2. The adhesive composition according to claim 1, wherein at least one of the partially hydrogenated block copolymers has a hydrogenation rate of 10 mol% to 80 mol% based on the total number of moles of the conjugated diene. 3. The adhesive composition according to claim 1, wherein the partially hydrogenated block copolymer has a structure before hydrogenation containing any of the following formulas (iv) to (vi). 4.
A- (BA) _n -X (iv)
[(AB) _k ] _m -X (v)
[(AB) _k -A] _m -X (vi)
(In the formulas (iv) to (vi), A represents a polymer block mainly containing a vinyl aromatic monomer unit, B represents a polymer block mainly containing a conjugated diene monomer unit, X represents a residue of a coupling agent, m, n and k represents an integer of 1 or more.)   At least one kind of the partially hydrogenated block copolymer is a partial water having one polymer block mainly composed of a vinyl aromatic monomer unit and one polymer block mainly composed of a conjugated diene monomer. The pressure-sensitive adhesive composition according to any one of claims 1 to 3, further comprising an addition block copolymer (d).   Of the partially hydrogenated block copolymer, the partially hydrogenated block copolymer (d) is based on 100% by mass of the partially hydrogenated block copolymer containing the partially hydrogenated block copolymer (d). The adhesive composition according to claim 4, comprising 20% by mass to 80% by mass.   The adhesive composition according to any one of claims 1 to 5, wherein at least one kind of the partially hydrogenated block copolymer contains a partially hydrogenated block copolymer (r) having a radial structure. .   An adhesive tape having the adhesive composition according to claim 1.