JP2022063038A - Block copolymer composition and adhesive composition - Google Patents

Abstract

To provide a block copolymer composition that strikes a balance between low viscosity and holding power and is used in an adhesive composition.SOLUTION: A block copolymer composition contains component (a) and component (b), with (a) and (b) being block copolymers. (b) includes component (b-1) with the ratio of its Mw to Mw of (a) being 1.5 or more and less than 2.5, component (b-2) with the ratio of its Mw to Mw of (a) being 2.5 or more and less than 3.4, and component (b-3) with the ratio of its Mw to Mw of (a) being 3.4 or more and less than 4.5. The content of (b-3) is 35 mass% or more relative to the total of (b). The amount of St in (a) and (b) is 22.0-26.0 mass% relative to the total amount of (a) and (b). In (a) and (b), the amount of vinyl bonds V(%) is 25% or more. In (a) and (b), the hydrogenation rate H(%) satisfies formula (1) in relation to the amount of vinyl bonds V(%). In (a) and (b), the hydrogenation rate of vinyl bonds before hydrogenation is 80% or more. Formula (1): V+50>H>V+10.SELECTED DRAWING: None

Description

The present invention relates to block copolymer compositions and adhesive compositions.

In recent years, vinyl aromatic monomer-conjugated diene monomer-based block polymers (for example, SBS: styrene-butadiene-styrene-block copolymers) have been used as base polymers for solution-type and hot-melt type adhesives and pressure-sensitive adhesives. , SIS: Styrene-isoprene-styrene-block copolymer) is widely used.
For example, Patent Document 1 and Patent Document 2 disclose an adhesive composition or an adhesive composition using SBS or SIS.

However, the adhesive composition or the pressure-sensitive adhesive composition using these SBS and SIS has a high melt viscosity, and the balance between the solubility and coatability and the pressure-sensitive adhesive characteristics such as adhesive strength is insufficient. It has the problem of. As a method for improving these properties, Patent Document 3 and Patent Document 4 describe a triblock copolymer, a diblock copolymer, and a pressure-sensitive adhesive composition containing these tri-branched or tetra-branched products. The technology for manufacturing is disclosed.

Special Publication No. 44-17307 Special Publication No. 56-49958 International Publication No. 2015/111675 International Publication No. 2015/111669

However, the pressure-sensitive adhesive compositions and the pressure-sensitive adhesive compositions disclosed in Patent Documents 3 and 4 are still insufficient in improving the above-mentioned various properties, and in particular, require high holding power such as tape. In applications, there is a problem that it is necessary to improve the balance between low viscosity and holding power performance.

Therefore, in the present invention, in view of the above-mentioned problems of the prior art, the adhesive composition having an excellent balance between low viscosity and holding power performance, and the block copolymer weight used in the adhesive composition. It is an object of the present invention to provide a coalesced composition.

As a result of diligent studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by a block copolymer composition having a specific structure and composition, and complete the present invention. I arrived.
That is, the present invention is as follows.

[1]
Component (a) is 50% by mass or more and 70% by mass or less,
A block copolymer composition containing the component (b) in an amount of 30% by mass or more and 50% by mass or less.
The component (a) comprises a polymer block (A) mainly composed of one vinyl aromatic monomer unit and a polymer block (B) mainly composed of at least one conjugated diene monomer unit. It is a block copolymer contained and having a weight average molecular weight of 50,000 or more and 80,000 or less.
The component (b) comprises a polymer block (A) mainly composed of at least two vinyl aromatic monomer units and a polymer block (B) mainly composed of at least one conjugated diene monomer unit. It is a block copolymer containing
The component (b) is a polymer obtained by coupling the component (a) with a coupling agent having a tetrafunctionality or higher.
The component (b) is a component (b-1) in which the weight average molecular weight ratio of the component (a) to the weight average molecular weight is 1.5 or more and less than 2.5, and the weight of the component (a) with respect to the weight average molecular weight. The component (b-2) having an average molecular weight ratio of 2.5 or more and less than 3.4, and the component (b) having a weight average molecular weight ratio of 3.4 or more and less than 4.5 to the weight average molecular weight of the component (a). -3) including
The content of the component (b-3) is 35% by mass or more with respect to the entire component (b).
The content of the vinyl aromatic monomer unit in the component (a) and the component (b) is 22.0% by mass or more with respect to the total amount of the component (a) and the component (b) 26. It is 0% by mass or less,
The vinyl bond amount V (%) of the conjugated diene monomer unit of the component (a) and the component (b) before hydrogenation is 25% or more.
The hydrogenation rate H (%) of the unsaturated double bond of the conjugated diene monomer unit possessed by the component (a) and the component (b) is as follows in relation to the vinyl bond amount V (%). Satisfy equation (1)
The hydrogenation rate of the vinyl bond of the conjugated diene monomer unit of the component (a) and the component (b) before hydrogenation is 80% or more.
Block copolymer composition.
V + 50>H> V + 10 ... Equation (1)
[2]
The block copolymer composition according to the above [1], wherein the polymer block (A) contained in the component (a) has a weight average molecular weight of 14,000 or more and 19,000 or less.
[3]
The component (a) is a block copolymer represented by (AB) and / or (AB) X.
The component (b-1) is (AB) ₂ X,
The component (b-2) is (AB) _3X ,
The block copolymer composition according to the above [1] or [2], wherein the component (b-3) is a block copolymer represented by (AB) _4X , respectively.
(A indicates a polymer block (A), B indicates a polymer block (B), and X indicates a residue of a coupling agent or a residue of a polymerization initiator.)
[4]
100 parts by mass of the block copolymer composition according to any one of [1] to [3] above.
1 to 250 parts by mass of adhesive,
Softener 0 to 120 parts by mass and
, A viscous adhesive composition.

According to the present invention, it is possible to provide an adhesive composition having an excellent balance between low viscosity and holding power performance, and a block copolymer composition used for the adhesive composition.

The figure which performed the vertical division from the inflection point between the peaks of a component (b-1), (b-2), and (b-3) is shown.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail.
It should be noted that the following embodiments are examples for explaining the present invention, and the present invention is not intended to be limited to the following contents. The present invention can be variously modified and carried out within the scope of the gist thereof.

[Block Copolymer Composition]
The block copolymer composition of the present embodiment is
The component (a) is contained in an amount of 50% by mass or more and 70% by mass or less, and the component (b) is contained in an amount of 30% by mass or more and 50% by mass or less.
The component (a) comprises a polymer block (A) mainly composed of one vinyl aromatic monomer unit and a polymer block (B) mainly composed of at least one conjugated diene monomer unit. It is a block copolymer contained and having a weight average molecular weight of 50,000 or more and 80,000 or less.
The component (b) is a polymer block (A) mainly composed of at least two vinyl aromatic monomer units, and a polymer block (B) mainly composed of at least one conjugated diene monomer unit. It is a block copolymer containing.
The component (b) is a polymer obtained by coupling the component (a) with a coupling agent having a tetrafunctionality or higher, and the component (b) is a weight average molecular weight with respect to the weight average molecular weight of the component (a). The component (b-1) having a ratio of 1.5 or more and less than 2.5, and the component (b-2) having a weight average molecular weight ratio of 2.5 or more and less than 3.4 to the weight average molecular weight of the component (a). , And the component (b-3) in which the weight average molecular weight ratio of the component (a) to the weight average molecular weight is 3.4 or more and less than 4.5.
The content of the component (b-3) is 35% by mass or more with respect to the entire component (b).
The content of the vinyl aromatic monomer unit in the component (a) and the component (b) is 22.0% by mass or more with respect to the total amount of the component (a) and the component (b) 26. It is 0% by mass or less.
The vinyl bond amount V (%) of the conjugated diene monomer unit of the component (a) and the component (b) before hydrogenation is 25% or more.
The hydrogenation rate H (%) of the unsaturated double bond of the conjugated diene monomer unit possessed by the component (a) and the component (b) is as follows in relation to the vinyl bond amount V (%). The formula (1) is satisfied, and the hydrogenation rate of the vinyl bond of the conjugated diene monomer unit of the component (a) and the component (b) before hydrogenation is 80% or more.
V + 50>H> V + 10 ・ ・ ・ Equation (1)

When the block copolymer composition of the present embodiment has the above-mentioned constitution, an adhesive composition having an excellent balance between low viscosity and holding power performance can be obtained.

The "vinyl aromatic monomer unit" indicates a structure produced as a result of polymerizing one vinyl aromatic hydrocarbon compound, and the "conjugated diene monomer unit" is obtained by polymerizing one conjugated diene compound. The resulting structure is shown.

The "polymer block (A) mainly composed of vinyl aromatic monomer units" contains 80% by mass or more, preferably 85% by mass or more, and more preferably 95% by mass or more of vinyl aromatic monomer units. Means a polymer block to be used.
Further, the "polymer block (B) mainly composed of a conjugated diene monomer unit" is a conjugated diene monomer unit in an amount of more than 70% by mass, preferably 85% by mass or more, and more preferably 95% by mass. It means the polymer block contained above.
Hereinafter, each component will be described in more detail.

(Component (a))
<Weight average molecular weight>
The component (a) has a polymer block (A) mainly composed of one vinyl aromatic monomer unit and a polymer block (B) mainly composed of at least one conjugated diene monomer unit. , A block copolymer having a weight average molecular weight of 50,000 or more and 80,000 or less.
The lower limit of the weight average molecular weight of the component (a) is 50,000 or more, preferably 60,000 or more, and more preferably 65,000 or more. When the weight average molecular weight of the component (a) is in the above range, the holding power tends to be improved. The upper limit of the weight average molecular weight of the component (a) is 80,000 or less, preferably 78,000 or less, and more preferably 76,000 or less. When the weight average molecular weight of the component (a) is in the above range, the low viscosity tends to be improved.
The weight average molecular weight of the component (a) can be determined by the evaluation method described in the examples.
The weight average molecular weight of the component (a) can be controlled within the above numerical range by adjusting the polymerization conditions such as the amount of the monomer added in the polymerization step, the polymerization time, and the polymerization temperature.

<Structure of component (a)>
The structure of the component (a) is not particularly limited, but is preferably a structure represented by any one or more of the following formulas (A1), (A2), (A11) and (A21). In particular, when the component (a) has a structure like (A1) or (A2), there is a tendency to obtain a block copolymer composition and an adhesive adhesive composition having excellent holding power.
AB ... (A1)
(AB) X ... (A2)
BAB ... (A11)
(BA) X ... (A21)
In the above formula, A indicates a polymer block mainly composed of a vinyl aromatic monomer unit, B indicates a polymer block mainly composed of a conjugated diene monomer unit, and X indicates a coupling agent. Indicates a residue or a residue of a polymerization initiator.

<Contents of vinyl aromatic monomer unit in component (a)>
The content of the vinyl aromatic monomer unit in the component (a) is 22.0% by mass or more and 26.0% by mass or less.
The lower limit of the content of the vinyl aromatic monomer unit in the component (a) is 22.0% by mass or more, preferably 22.5% by mass or more, and more preferably 23.0% by mass or more. ..
When the content of the vinyl aromatic monomer unit in the component (a) is in the above range, the holding power tends to be improved.
The upper limit of the content of the vinyl aromatic monomer unit in the component (a) is 26.0% by mass or less, preferably 25.5% by mass or less, and more preferably 25.0% by mass or less. Is. When the content of the vinyl aromatic monomer unit in the component (a) is in the above range, the low viscosity tends to be improved, and especially in the low temperature range (about 160 ° C. or lower), the low viscosity is improved. Tend to do.

<Amount of vinyl bond before hydrogenation of conjugated diene monomer unit of component (a)>
The vinyl bond amount (V) of the conjugated diene monomer unit of the component (a) before hydrogen addition is 25% or more, and the vinyl bond of the conjugated diene monomer unit of the component (a) before hydrogen addition. The hydrogenation rate is 80% or more, and the hydrogenation rate (H) of the unsaturated double bond of the conjugated diene monomer unit of the component (a) satisfies the following formula (1).
V + 50>H> V + 10 ... Equation (1)

<Hydrogenation rate of vinyl bond before hydrogenation of conjugated diene monomer unit of component (a)>
The hydrogenation rate of the vinyl bond of the conjugated diene monomer unit of the component (a) before hydrogenation is 80% or more, preferably 85% or more, and more preferably 90% or more.
When the hydrogenation rate of the vinyl bond before hydrogenation of the conjugated diene monomer unit of the component (a) is within the above range, the weather resistance and the heat resistance tend to be improved.

<Hydrogenation rate of unsaturated double bond of conjugated diene monomer unit possessed by component (a)>
Further, when the hydrogenation rate H of the unsaturated double bond of the conjugated diene monomer unit possessed by the component (a) satisfies the above (formula 1), it exhibits high weather resistance and heat resistance.
Further, from the viewpoint of enhancing the compatibility with the tackifier resin generally used for the adhesive composition and enhancing the adhesive performance, the conjugated diene monomer unit of the component (a) is unsaturated. The hydrogenation rate (H) of the double bond is preferably 30% or more and 70% or less, more preferably 40% or more and 60% or less, and further preferably 45% or more and 55% or less.

<Vinyl bond amount (V) of the conjugated diene monomer unit of component (a) before hydrogenation>
The vinyl bond amount (V) of the conjugated diene monomer unit of the component (a) before hydrogenation is 25% or more, preferably 28% or more, and more preferably 30% or more.
When the vinyl bond amount (V) of the conjugated diene monomer unit of the component (a) before hydrogenation is in the above range, the low viscosity tends to be improved.
Further, from the viewpoint of improving the low viscosity, the hydrogenation rate (H) of the unsaturated double bond of the conjugated diene monomer unit of the component (a) preferably satisfies the following (formula 2).
V + 25> H ... (Equation 2)

The amount of vinyl bond of the conjugated diene monomer unit in the component (a) constituting the block copolymer composition and the component (b) described later can be determined by using, for example, ethers or tertiary amines. Can be controlled. Specifically, one or a mixture of two or more selected from ethylene glycol dimethyl ether, tetrahydrofuran, α-methoxytetrahydrofuran, N, N, N', N'-tetramethylethylenediamine and the like is used. These are preferably added to the polymerization solvent at a stage before the conjugated diene monomer is added.

<Weight average molecular weight of the polymer block (A) contained in the component (a)>
The weight average molecular weight of the polymer block (A) contained in the component (a) is preferably 14,000 or more, more preferably 15,000 or more, and even more preferably 16,000 or more. When the weight average molecular weight of the polymer block (A) contained in the component (a) is in the above range, the holding power tends to be improved.
Further, the weight average molecular weight of the polymer block (A) contained in the component (a) is preferably 19,000 or less, and more preferably 18,000 or less. When the weight average molecular weight of the polymer block (A) contained in the component (a) is in the above range, the low viscosity tends to be improved.
The weight average molecular weight of the polymer block (A) contained in the component (a) can be measured by the method described in Examples described later.
The weight average molecular weight of the polymer block (A) contained in the component (a) is adjusted by adjusting the type and the amount of the monomer added in the polymerization step of the component (a) in the manufacturing step of the block copolymer composition. By doing so, the control can be performed within the above numerical range.

The content of the vinyl aromatic monomer unit in the block copolymer constituting the block copolymer composition of the present embodiment, the vinyl bond amount V of the conjugated diene monomer unit before hydrogenation, and the conjugated diene single amount. The hydrogenation rate of the vinyl bond before hydrogenation of the body unit, the hydrogenation rate H of the unsaturated double bond of the conjugated diene monomer unit, and the weight average molecular weight of the polymer block (A) are described in Examples described later. The block copolymer composition can be measured according to the method for measuring the physical properties of the block copolymer composition.

(Component (b))
The component (b) comprises a polymer block (A) mainly composed of at least two vinyl aromatic monomer units and a polymer block (B) mainly composed of at least one conjugated diene monomer unit. It is a block copolymer contained.
The component (b) is a polymer obtained by coupling the component (a) with a coupling agent having a tetrafunctionality or higher.
Further, the component (b) is a component (b-1) in which the weight average molecular weight ratio of the component (a) to the weight average molecular weight is 1.5 or more and less than 2.5, and the weight of the component (a) with respect to the weight average molecular weight. The component (b-2) having an average molecular weight ratio of 2.5 or more and less than 3.4, and the component (a) having a weight average molecular weight ratio of 3.4 or more and less than 4.5 to the weight average molecular weight (a). Contains b-3).
The content of the component (b-3) is 35% by mass or more with respect to the entire component (b).
When the component (b) has the above-mentioned structure, it becomes a block copolymer composition having an excellent balance between holding power and low viscosity.
The content of the component (b-3) is 35% by mass or more, preferably 40% by mass or more, and more preferably 45% by mass or more with respect to the entire component (b). When the content of the component (b-3) is in the above range, the holding power tends to be improved. The content of the component (b-3) is preferably 65% by mass or less, more preferably 60% by mass or less, and further preferably 55% by mass or less with respect to the entire component (b). preferable. When the content of the component (b-3) is in the above range, the low viscosity tends to be improved.
Further, from the viewpoint of improving the holding power, the content of the component (b-3) is preferably higher than the content of the component (b-2), and the content of the component (b-2) is the content of the component (b-1). It is preferable that the content is higher than the content of.

It is a gel permeation that the component (b-1), the component (b-2), and the component (b-3) are contained in the block copolymer composition of the present embodiment as the component (b). It can be determined by the difference in the position of the peak of the molecular weight distribution curve under the predetermined conditions shown below in chromatography (hereinafter, also referred to as “GPC”).
That is, in the GPC chart, the peak (component (b-1)) at 1.5 times or more and less than 2.5 times the weight average molecular weight of the component (a) and 2.5 times or more the weight average molecular weight of the component (a). Confirm the peak at less than 3.4 times (component (b-2)) and the peak at 3.4 times or more and less than 4.5 times the weight average molecular weight of component (a) (component (b-3)). Therefore, the component (b-1), the component (b-2), and the component (b-3) contained in the block copolymer composition can be confirmed.
The weight average molecular weight of the component (b) can be determined by the evaluation method described in the examples.

Further, the area ratios of the component (b-1), the component (b-2), and the component (b-3) to the total area of the component (b) are described in the apparatus (ACQUITY APC system) described in Examples described later. ) And under the conditions, after GPC measurement, it is obtained by performing vertical division to the baseline at the inflection point between peaks of the GPC curve using the system software also described in the embodiment.
Here, the inflection between the peaks of the components (b-1), (b-2), and (b-3) is the lowest point (valley peak) that is the lowest in the vertical direction between the adjacent peaks. If the lowest points are continuous, the middle point is used. With the above-mentioned inflection point, vertical division is performed using a predetermined waveform separation software, and after the division, the weight average molecular weight of each component is calculated and the area ratio is calculated.
The content of the components (b-1) to (b-3) can be calculated from the area ratio.
FIG. 1 shows a diagram in which the inflection points between the peaks of the components (b-1), (b-2), and (b-3) are obtained and the inflection points are vertically divided.

The structure of the component (b) is not particularly limited, but the component (b-1) is preferably a structure represented by any one or more of the following formulas (B1) and (B11), and the component (b-1) is preferable. (B-2) preferably has a structure represented by any one or more of the following formulas (B2) and (B21), and the component (b-3) is represented by the following formulas (B3) and (B31). It is preferable that the structure is represented by any one or more of them.
From the viewpoint of improving the holding power, it is particularly preferable that the component (b-1) has a structure represented by the following formula (B1), and the component (b-2) is represented by the following formula (B2). The structure is preferable, and the component (b-3) is preferably a structure represented by the following formula (B3).
(AB) ₂ X ... (B1)
(BAB) ₂ X ... (B11)
(AB) ₃ X ... (B2)
(BAB) ₃ X ... (B21)
(AB) ₄ X ... (B3)
(BAB) ₄ X ... (B31)

In each of the above formulas, A is a polymer block mainly composed of a vinyl aromatic monomer unit, B is a polymer block mainly composed of a conjugated diene monomer, and X is a coupling agent. Indicates a residue or a residue of a polymerization initiator.

Since the component (b) is a coupling of the above-mentioned component (a), the content of the vinyl aromatic monomer unit in the component (b) and the conjugated diene monomer unit contained in the component (b). The amount of vinyl bond (V) before hydrogenation, the hydrogenation rate of the vinyl bond before hydrogenation of the conjugated diene monomer unit of component (b), and the non-conducting diene monomer unit of component (b). The range of the hydrogenation rate (H) of the saturated double bond and the weight average molecular weight of the polymer block (A) contained in the component (b) is the same as that described in the above-mentioned section of the component (a). , The numerical range is the same as that of the component (a).

Since the block copolymer composition of the present embodiment contains the component (a) and the component (b) as essential components, the block copolymer composition contains the vinyl aromatic monomer unit in the component (a) and the component (b). The amount is 22.0% by mass or more and 26.0% by mass or less, and the vinyl bond amount V (%) of the conjugated diene monomer unit of the component (a) and the component (b) before hydrogenation is 25. % Or more, and the hydrogenation rate H (%) of the unsaturated double bond of the conjugated diene monomer unit possessed by the component (a) and the component (b) is the vinyl bond amount V (%). In relation to this, the following formula (1) is satisfied, and the hydrogenation rate of the vinyl bond of the conjugated diene monomer unit of the component (a) and the component (b) before hydrogenation is 80% or more.
V + 50>H> V + 10 ・ ・ ・ Equation (1)
That is, these physical properties are in the same numerical range as that of the component (a) for the same reason as that described in the above-mentioned section of the component (a).

(Block Copolymer Composition Containing Component (a) and Component (b))
The block copolymer composition of the present embodiment contains the component (a) in an amount of 50% by mass or more and 70% by mass or less, and the component (b) in an amount of 30% by mass or more and 50% by mass or less.
Since the component (a) is a component having a lower molecular weight than the component (b), the low viscosity is improved when the content of the component (a) is large. From these viewpoints, the content of the component (a) is preferably 53% by mass or more, more preferably 55% by mass or more.
If the content of the component (a) is too large, cross-linking is not sufficiently formed, and the holding power tends to decrease. Therefore, the content of the component (a) is preferably 67% by mass or less, more preferably 65% by mass or less.
The component (b) has a large content of the component (b-3) that exhibits a high holding power, and when the content of the component (b) is high, the block copolymer composition and the adhesive adhesive have a high holding power. Compositions tend to be obtained. Therefore, the content of the component (b) is preferably 33% by mass or more, and more preferably 35% by mass or more.
Since the component (b) is a component having a higher molecular weight than the component (a), if the content of the component (b) is too large, the low viscosity is lowered. Therefore, the content of the component (b) is preferably 47% by mass or less, more preferably 45% by mass or less.

The vinyl aromatic hydrocarbon compound in the vinyl aromatic hydrocarbon compound unit constituting the polymer block in the component (a) and the component (b) is not limited to the following, and is, for example, styrene, α-methylstyrene, p. -Alkylstyrene such as methylstyrene and p-tershall butylstyrene; alkoxystyrene such as p-methoxystyrene; vinylnaphthalene and the like.
Among these, styrene is preferable as the vinyl aromatic hydrocarbon.
The vinyl aromatic hydrocarbon compound may be used alone or in combination of two or more.
The conjugated diene compound in the conjugated diene monomer unit constituting the polymer block in the components (a) and (b) is not particularly limited as long as it is a diolefin having a conjugated double bond, and is, for example, 1,3-. Examples thereof include butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene.
Among these, 1,3-butadiene and isoprene are preferable as the conjugated diene compound. Further, it is more preferable to use 1,3-butadiene because the adhesive composition tends to have excellent heat aging resistance and light resistance.
The conjugated diene compound may be used alone or in combination of two or more.

[Method for producing block copolymer composition]
(Polymerization reaction and coupling reaction)
As a method for producing the block copolymer composition of the present embodiment, for example, a vinyl aromatic hydrocarbon compound such as styrene and a conjugated diene such as butadiene using an organic lithium compound as a polymerization initiator in an inert hydrocarbon solvent are used. A polymerization step of copolymerizing a compound to obtain a block copolymer and a coupling step of reacting the obtained block copolymer and a coupling agent to obtain a component (a) and a component (b). The method of having is mentioned.
In this case, the coupled block copolymer becomes the component (b), and the block copolymer remaining without coupling becomes the component (a).
By controlling the amount of the coupling agent added in this coupling reaction, the contents of the component (a) and the component (b) can be adjusted to the above-mentioned predetermined range.
The weight average molecular weight of the components (a) and (b) can be adjusted by controlling the amount of the polymerization initiator such as an organolithium compound.
After the completion of the polymerization reaction, a coupling reaction is carried out, water, alcohol, acid, etc. are added to inactivate the active species, and then, for example, steam stripping or the like is performed to separate the polymerization solvent, and then the components are dried. a) and (b) can be obtained.

The method for polymerizing the block copolymer of the component (a) and the component (b) is not particularly limited, and examples thereof include a polymerization method such as coordination polymerization, anionic polymerization, or cationic polymerization.
Of these, anionic polymerization is preferable from the viewpoint of ease of structural control. As a method for producing a block copolymer by anionic polymerization, a known method can be used, and the method is not particularly limited. Publication No. 49-36975, Japanese Patent Publication No. 48-2423, Japanese Patent Publication No. 48-4106, Japanese Patent Publication No. 56-28925, Japanese Patent Application Laid-Open No. 59-166518, Japanese Patent Application Laid-Open No. 60-186577 Examples thereof include the methods described in the publications and the like.

The inert hydrocarbon solvent used in the polymerization steps of the components (a) and (b) is not particularly limited, and is, for example, an aliphatic hydrocarbon such as butane, pentane, hexane, isopentan, heptane, octane, and isooctane; cyclo. Alicyclic hydrocarbons such as pentane, methylcyclopentane, cyclohexane, methylcyclohexane and ethylcyclohexane; hydrocarbon solvents such as aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene can be mentioned. Only one of these may be used, or two or more thereof may be mixed and used.

The organolithium compound used as the polymerization initiator in the polymerization steps of the components (a) and (b) is not particularly limited, and known compounds can be used, for example, ethyllithium, propyllithium, n-. Examples thereof include butyllithium, sec-butyllithium, tert-butyllithium, phenyllithium, propenyllithium, hexyllithium and the like. In particular, n-butyllithium and sec-butyllithium are preferable. As the organolithium compound, only one kind may be used, or a mixture of two or more kinds may be used.

As a coupling agent for obtaining a multi-branched block copolymer, known ones can be used.
The tetrafunctional coupling agent is not particularly limited, and is, for example, a tetrafunctional halogenated alkane such as carbon tetrachloride, carbon tetrabromide, or tetrachloroethane; a tetrafunctional halogenated silane such as tetrachlorosilane or tetrabromosilane. Tetrafunctional alkoxysilanes such as tetramethoxysilane and tetraethoxysilane; tetrafunctional tin compounds such as tetrachlorotin, tetrabromotin and tetrabutyltin can be mentioned.
The five-functional or higher functional coupling agent is not particularly limited, and examples thereof include 1,1,1,2,2-pentachloroethane, perchloroethane, pentachlorobenzene, perchlorobenzene, octabromodiphenyl ether, and decabromodiphenyl ether. .. In addition, epoxidized soybean oil, a compound containing an epoxy group having 2 to 6 functions, a carboxylic acid ester, a polyvinyl compound such as divinylbenzene, and the like can also be used.
One type of coupling agent may be used alone, or two or more types may be used in combination.
Among these, tetramethoxysilane and tetraethoxysilane are particularly preferable.

The area ratio of the component (b-1), the component (b-2), and the component (b-3) in the GPC elution curve in the component (b) is the amount of the coupling agent added in the coupling reaction as described above. , Temperature and time can be controlled.
Thereby, the weight average molecular weight of each of the component (b-1), the component (b-2), and the component (b-3), and the content of each component can be controlled.
Specifically, when the coupling agent is an alkoxysilane compound, the time from when the reaction temperature reaches the maximum temperature until the coupling agent is added is set to 1 to 30 minutes, and the reaction time of the coupling agent is set to 1. Examples thereof include a method in which the reaction temperature is 55 to 100 ° C. for about 60 minutes, and the amount of the coupling agent added is adjusted so that the mol ratio to the total mol number of the polymerization initiator is 0.025 to 0.30.
When the coupling agent is other than the alkoxysilane compound, the time from when the reaction temperature reaches the maximum temperature until the coupling agent is added is set to 1 to 30 minutes, and the reaction time of the coupling agent is set to 1 to 35. Examples thereof include a method in which the reaction temperature is set to 50 to 95 ° C. for 1 minute, and the amount of the coupling agent added is adjusted so that the mol ratio to the total mol number of the polymerization initiator is 0.025 to 0.20.

(Hydrogenation reaction)
In the block copolymer composition of the present embodiment, some or all of the unsaturated double bonds derived from the conjugated diene compound of the component (a) and the component (b) are hydrogenated.
The hydrogenation method is not particularly limited, and a known technique using a hydrogenation catalyst can be used.

As the hydrogenation catalyst, a known catalyst can be used without particular limitation. For example, a supported non-uniform system in which a metal such as Ni, Pt, Pd, Ru is supported on carbon, silica, alumina, silica soil or the like. Hydrogenation catalyst; so-called Cheegler type hydrogenation catalyst using organic acid salts such as Ni, Co, Fe, Cr or transition metal salts such as acetylacetone salt and reducing agents such as organic aluminum; Ti, Ru, Rh, Zr and the like. A homogeneous hydrogenation catalyst such as a so-called organic metal complex such as an organic metal compound is used.

Specifically, Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841, Japanese Patent Publication No. 1-377970, Japanese Patent Publication No. 1-53851 and Japanese Patent Publication No. 2-9041 The hydrogenation catalyst described in Japanese Patent Publication No. can be used.
Among these, suitable hydrogenation catalysts include titanocene compounds, reducing organometallic compounds, and mixtures thereof.

The titanocene compound is not particularly limited, and examples thereof include the compounds described in JP-A-8-109219. Specifically, at least one ligand having a (substituted) cyclopentadienyl skeleton, an indenyl skeleton, or a fluorenyl skeleton such as biscyclopentadienyl titanium dichloride, monopentamethylcyclopentadienyl titanium trichloride, etc. Examples thereof include compounds having.

The reducing organic metal compound is not particularly limited, and examples thereof include an organic alkali metal compound such as organic lithium, an organomagnesium compound, an organoaluminum compound, an organoboron compound, and an organozinc compound.

The hydrogenation reaction temperature is preferably 0 to 200 ° C, more preferably 30 to 150 ° C. The pressure of hydrogen used in the hydrogenation reaction is preferably 0.1 to 15 MPa, more preferably 0.2 to 10 MPa, and even more preferably 0.3 to 5 MPa. Further, the hydrogenation reaction time is preferably 3 minutes to 10 hours, more preferably 10 minutes to 5 hours.
The hydrogenation reaction may be a batch process, a continuous process, or a combination thereof.

A block copolymer composition can be obtained by removing the catalyst residue from the block copolymer solution obtained through the hydrogenation reaction, if necessary, and separating the solution.
The method for separating the solvent is not particularly limited, but for example, a polar solvent that is a poor solvent for the hydrogenated block copolymer such as acetone or alcohol is added to the reaction solution after hydrogenation to precipitate and recover the polymer. Examples thereof include a method in which the reaction solution after hydrogenation is put into boiling water under stirring and the solvent is removed and recovered by steam stripping, and a method in which the reaction solution after hydrogenation is heated to distill off the solvent. ..

Further, the polymer block (A) amount (mass%), that is, the block ratio with respect to the total vinyl aromatic monomer unit amount (100% by mass) used for polymerizing the block copolymer is preferably 90% by mass. The above is more preferably 95% by mass or more, and further preferably 97% by mass or more. When the block ratio is within the above range, a block copolymer composition having excellent finishability tends to be obtained, and the adhesive adhesive composition containing this block copolymer composition has adhesive strength and retention. It tends to be superior in power.

The polymer block (A) amount (% by mass), that is, the block ratio can be calculated by calculating the block styrene content and dividing by the total vinyl aromatic monomer unit amount as follows.
That is, the block copolymer before hydrogenation is dissolved in chloroform, and an osminic acid / tertiary butyl hydroperoxide solution is added to break the double bond of the butadiene component. Next, methanol is added, the mixture is filtered, the filtrate is dissolved in chloroform, and the obtained solution can be calculated from the peak intensity (absorption wavelength: 262 nm) with an ultraviolet spectrophotometer.

In the method for producing a block copolymer composition of the present embodiment, a step of decalcifying metals derived from a polymerization initiator or the like can be adopted, if necessary. Further, in the method for producing a block copolymer composition of the present embodiment, a step of adding an antioxidant, a neutralizing agent, a surfactant and the like may be further adopted, if necessary.
The antioxidant is not particularly limited, and examples thereof include the same hindered phenol-based compounds, phosphorus-based compounds, and sulfur-based compounds as those described below.
The neutralizing agent is not particularly limited, and examples thereof include various metal stearic acid salts, hydrotalcite, and benzoic acid.
The surfactant is not particularly limited, and examples thereof include anionic surfactants, nonionic surfactants, cationic surfactants, and the like. The anionic surfactant is not particularly limited, and examples thereof include fatty acid salts, alkyl sulfate ester salts, and alkylaryl sulfonates. The nonionic surfactant is not particularly limited, and examples thereof include polyoxyethylene alkyl ether and polyoxyethylene alkyl aryl ether. Further, the cationic surfactant is not particularly limited, and examples thereof include an alkylamine salt and a quaternary ammonium salt.

In the block copolymer composition of the present embodiment, which can be produced as described above, a polar group-containing functional group containing an atom selected from nitrogen, oxygen, silicon, phosphorus, sulfur and tin is bonded to the block copolymer. It may contain a so-called modified block copolymer or a modified block copolymer obtained by modifying a block copolymer component with a modifying agent such as maleic anhydride. Such a modified block copolymer can be obtained by subjecting the component (a) and the component (b) to a known modification reaction.

The method for imparting these functional groups is not particularly limited, and for example, a method for adding a functional group to the polymer by using a compound having a functional group as an initiator, a monomer, a coupling agent or a stopping agent is used. Can be mentioned.

As the initiator containing a functional group, an initiator containing an N group is preferable, and dioctylaminolithium, di-2-ethylhexylaminolithium, ethylbenzylaminolithium, (3- (dibutylamino) -propyl) lithium, and piperidi Benzyl and the like can be mentioned.

Examples of the monomer containing a functional group include compounds containing a hydroxyl group, an acid anhydride group, an epoxy group, an amino group, an amide group, a silanol group, and an alkoxysilane group in the monomer used for the above-mentioned polymerization. .. Of these, a monomer containing an N group is preferable, and N, N-dimethylvinylbenzylamine, N, N-diethylvinylbenzylamine, N, N-dipropylvinylbenzylamine, N, N-dibutylvinylbenzylamine, N, N-diphenylvinylbenzylamine, 2-dimethylaminoethylstyrene, 2-diethylaminoethylstyrene, 2-bis (trimethylsilyl) aminoethylstyrene, 1- (4-N, N-dimethylaminophenyl) -1-phenylethylene , N, N-dimethyl-2- (4-vinylbenzyloxy) ethylamine, 4- (2-pyrrolidinoethyl) styrene, 4- (2-piperidinoethyl) styrene, 4- (2-hexamethyleneiminoethyl) styrene, 4- (2-morpholinoethyl) styrene, 4- (2-thiadinoethyl) styrene, 4- (2-N-methylpiperazinoethyl) styrene, 1-((4-vinylphenoxy) methyl) pyrrolidine, 1-( 4-vinylbenzyloxymethyl) pyrrolidine and the like can be mentioned.

Further, as the coupling agent and the terminator containing a functional group, among the above-mentioned coupling agents, a compound containing a hydroxyl group, an acid anhydride group, an epoxy group, an amino group, an amide group, a silanol group, an alkoxysilane group and the like can be used. Can be mentioned. Of these, a coupling agent containing an N group or an O group is preferable, and tetraglycidylmethoxylenidamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, tetraglycidyl-p-phenylenediamine, tetraglycidyldiaminodiphenylmethane, diglycidylaniline. , Γ-Caprolactone, γ-glycidoxyethyl trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriphenoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxy Examples thereof include propyldiethylethoxysilane, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N, N'-dimethylpropyleneurea and N-methylpyrrolidone.

After producing the block copolymers of the components (a) and (b) constituting the block copolymer of the present embodiment as described above, the block polymer is isolated, that is, finished by the method described later. , Obtain a block copolymer composition.
When the polymerization steps of the components (a) and (b) are carried out in an inert hydrocarbon solvent, the inert hydrocarbon solvent is removed to isolate the block copolymer. As a specific method for removing the solvent, steam stripping can be mentioned. A hydrous crumb can be obtained by steam stripping, and the obtained hydrous crumb can be dried to obtain a block copolymer composition.

In steam stripping, it is preferable to use a surfactant as a crumbing agent. Examples of such a surfactant include, but are not limited to, anionic surfactants, cationic surfactants, and nonionic surfactants as described above. These surfactants can generally be added in an amount of 0.1 to 3000 ppm to water in the stripping zone. In addition to the surfactant, water-soluble salts of metals such as Li, Na, Mg, Ca, Al, and Zn can also be used as a dispersion aid for crumbs.

The concentration of the crumb-shaped block copolymer dispersed in water obtained through the block copolymer polymerization step and the steam stripping is generally 0.1 to 20% by mass (ratio of the stripping zone to water). be. Within this range, a crumb having a good particle size can be obtained without causing any trouble in operation. It is preferable to adjust the water content of the block copolymer crumb to 1 to 30% by mass by dehydration, and then dry the block copolymer until the water content becomes 1% by mass or less.

In the dewatering step of the crumb, dehydration may be performed with a compressed water squeezer such as a roll, a Banbury type dehydrator, a screw extruder type squeezing dehydrator, or a conveyor or a box-shaped hot air dryer at the same time. good.

[Adhesive composition]
The adhesive composition of the present embodiment contains the above-mentioned block copolymer composition, a tackifier, and a softening agent.
The content of the tackifier in the adhesive composition is 1 to 250 parts by mass with respect to 100 parts by mass of the block copolymer composition, and the content of the softening agent is 100 parts by mass of the block copolymer composition 100. It is 120 parts by mass or less with respect to the mass part. As a result, a viscous adhesive composition having a high holding power and a low viscosity and having an excellent balance between the holding power and the viscosity can be obtained.
The adhesive composition of the present embodiment may contain other components described later, if necessary.
From the viewpoint of obtaining a pressure-sensitive adhesive composition having higher holding power, the content of the tackifier is preferably 1 to 200 parts by mass with respect to 100 parts by mass of the block copolymer composition, and 1 to 150 parts by mass. It is more preferably parts, and even more preferably 1 to 130 parts by mass. From the same viewpoint, the content of the softening agent is preferably 80 parts by mass or less, more preferably 50 parts by mass or less, based on 100 parts by mass of the block copolymer composition.

In addition, the adhesive composition of the present embodiment includes styrene-butadiene block copolymers, styrene-isoprene block copolymers, and hydrogenated styrene-butadiene blocks other than the block copolymer compositions described above. When other polymers such as polymers and hydrogenated styrene-isoprene block copolymers are added, the total content of the other polymers and the above-mentioned components (a) and (b) is 100 mass. It is preferable that the tackifier contains 1 to 250 parts by mass of the tackifier described later and 0 to 120 parts by mass of the softening agent described later.

(Adhesive)
The tackifier can be selected from a wide variety depending on the intended use and required performance of the obtained adhesive composition.
The tackifier is not particularly limited, and for example, natural rosin, modified rosin, glycerol ester of natural rosin, glycerol ester of modified rosin, pentaerythritol ester of natural rosin, pentaerythritol ester of modified rosin, hydrogenated rosin, and hydrogen. Additive rosin rosin compounds such as pentaerythritol ester; natural terpene copolymers, natural terpene three-dimensional polymers, aromatic-modified terpene fats, aromatic-modified terpene resin hydrogenated derivatives, terpene phenolic resins, terpenephenolic resin hydrogenated Terpene compounds such as derivatives, terpene resins (monoterpene, diterpene, triterpene, polyperten, etc.), hydrogenated terpene resins, hydrogenated derivatives of hydrogenated terpene resins; aliphatic petroleum hydrocarbon resins (C5 based resins), aliphatic petroleum Hydrocarbon Derivatives of Hydrocarbons, Aromatic Petrocarbonate Resins (C9-based Resins), Hydrogenated Derivatives of Aromatic Petrocarbonate Resins, Dicyclopentadiene Resins, Hydrogenated Derivatives of Dicyclopentadiene Resins, C5 / C9 Hydrocarbon compounds such as copolymerized resins, hydrogenated derivatives of C5 / C9 copolymerized resins, cyclic aliphatic petroleum hydrocarbon resins, hydrogenated derivatives of cyclic aliphatic petroleum hydrocarbon resins, aromatic group-containing resins It can be exemplified.
These tackifiers can be used alone or in combination of two or more.
The C5 / C9 copolymerization system is a copolymerized petroleum resin obtained by polymerizing a mixture of a C5 fraction and a C9 fraction as a raw material.
As the tackifier, a liquid type tackifier having a color tone of colorless to pale yellow, substantially no odor, and good thermal stability can also be used.
Hereinafter, preferable tackifiers according to the intended use and performance will be described more specifically.

<Adhesive for hydrogenated derivatives>
From the viewpoint of suppressing coloring and low odor, a hydrogenated derivative is preferable as the tackifier.
The hydrogenated derivative is not particularly limited, and is, for example, a hydrogenated derivative of an aromatic-modified terpene resin, a hydrogenated derivative of a terpene phenol resin, a hydrogenated derivative of a hydrogenated terpene resin, and an aliphatic petroleum hydrocarbon resin (C5 series resin). ), Hydrogenated derivative of aromatic petroleum hydrocarbon resin (C9 series resin), Hydrogenated derivative of dicyclopentadiene based resin, Hydrogenated derivative of C5 / C9 copolymer resin, Cyclic aliphatic petroleum hydrocarbon Examples include hydrogenated derivatives of the resin. Among these, a hydrogenated derivative of an aromatic petroleum hydrocarbon resin (C9-based resin), a hydrogenated derivative of a dicyclopentadiene-based resin, a hydrogenated derivative of a hydrogenated terpene resin, and the like are particularly preferable.
Commercially available products of such hydrogenated derivatives are not particularly limited, but are Arakawa Chemical's Archon P and M series (trade name), Idemitsu Kosan's Imarve S and P series, and Exxon Mobile Chemical's Escolets. Examples include the 5000 series (trade name) and the Clearon P series manufactured by Yasuhara Chemical Co., Ltd.

<Adhesives other than hydrogenated derivatives>
The tackifier other than the hydrogenated derivative is not particularly limited, and for example, natural rosin, modified rosin, glycerol ester of natural rosin, glycerol ester of modified rosin, pentaerythritol ester of natural rosin, pentaerythritol ester of modified rosin, and the like. Hydrogenated rosin, pentaerythritol ester of hydrogenated rosin; copolymer of natural rosin, three-dimensional polymer of natural turpen, aromatic-modified terpene resin, terpene phenol resin, terpene resin, hydrogenated terpene resin; aliphatic petroleum hydrocarbon resin (C5) Examples include rosin), aromatic petroleum hydrocarbon resin (C9 resin), dicyclopentadiene resin, C5 / C9 copolymer resin, and cyclic aliphatic petroleum hydrocarbon resin.
Among these, aliphatic petroleum hydrocarbon resin (C5 series resin), aromatic petroleum hydrocarbon resin (C9 series resin), C5 / C9 copolymer resin, cyclic aliphatic petroleum hydrocarbon resin, terpene resin, natural and Modified rosin esters, as well as mixtures thereof, are preferred.
As commercial products, as aliphatic petroleum hydrocarbon resins (C5 series resins), Quinton 100 series (trade name) manufactured by Nippon Zeon, Escolets 1000 series manufactured by Exxon Mobile Chemical, and WINGTACK series (product) manufactured by Clay Valley. Name), aromatic petroleum hydrocarbon resin (C9 series resin), C5 / C9 copolymer resin, PICCOTAC series (trade name) manufactured by Eastman Chemical Co., Ltd., Escoletz 2000 series (trade name) manufactured by Exxon Mobile Chemical Co., Ltd. ), FTR series (trade name) manufactured by Mitsui Kagaku Co., Ltd., terpene resin, natural and modified hydrocarbon esters, SYLVALITE series manufactured by Arizona Chemical Co., Ltd., SYLVARES series (trade name), PICCOLYTE series manufactured by PINOVA (trade name). ) Etc. can be mentioned.

<Aliphatic adhesives>
From the viewpoint of obtaining a pressure-sensitive adhesive composition having high adhesiveness and high holding power, and from the viewpoint of economy, it is preferable to use an aliphatic pressure-sensitive adhesive as the pressure-sensitive adhesive.
The aliphatic tackifier is not particularly limited, but for example, an aliphatic petroleum hydrocarbon resin (C5 series resin), a hydrogenated derivative of an aliphatic petroleum hydrocarbon resin (C5 series resin), and a C5 / C9 copolymer type. Examples thereof include a resin and a hydrogenated derivative of a C5 / C9 copolymer resin.
The aliphatic tackifier has an aliphatic hydrocarbon group content of preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more. Further, it refers to a tackifier having an amount of 88% by mass or more, and even more preferably 95% by mass or more. When the content of the aliphatic hydrocarbon group is within the above range, the adhesiveness, holding power and economic efficiency tend to be further improved.

The aliphatic tackifier can be produced by homopolymerizing or copolymerizing a monomer having an aliphatic group and a polymerizable unsaturated group.
Monomers having an aliphatic group and a polymerizable unsaturated group are not particularly limited, and examples thereof include natural and synthetic terpenes containing a C5 or C6 cyclopentyl or a cyclohexyl group. The other monomers that can be used in the copolymerization are not particularly limited, but are, for example, 1,3-butadiene, cis-1,3-pentadiene, trans-1,3-pentadiene, and 2-methyl-1,3-. Examples thereof include butadiene, 2-methyl-2-butene, cyclopentadiene, dicyclopentadiene, terpene, terpene-phenol resin and the like.

<Aromatic adhesives>
From the viewpoint of obtaining a pressure-sensitive adhesive composition having high adhesive strength and high coatability, it is preferable to use an aromatic pressure-sensitive adhesive as the pressure-sensitive adhesive.
The aromatic pressure-sensitive adhesive is not particularly limited, and examples thereof include aromatic petroleum hydrocarbon resins (C9-based resins) and C5 / C9 copolymer-based resins.
The aromatic tackifier has an aromatic hydrocarbon group content of preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more. , More preferably 88% by mass or more, and even more preferably 95% by mass or more. When the content of the aromatic hydrocarbon group is within the above range, the adhesive strength and the coatability tend to be further improved.

The aromatic tackifier can be produced by homopolymerizing or copolymerizing a monomer having an aromatic group and a polymerizable unsaturated group, respectively.
The monomer having an aromatic group and a polymerizable unsaturated group is not particularly limited, and for example, styrene, α-methylstyrene, vinyltoluene, methoxystyrene, TERT-butylstyrene, chlorostyrene, and inden monomer (methylinden). Including). The other monomers that can be used in the copolymerization are not particularly limited, but are, for example, 1,3-butadiene, cis-1,3-pentadiene, trans-1,3-pentadiene, and 2-methyl-1,3-. Examples thereof include butadiene, 2-methyl-2-butene, cyclopentadiene, dicyclopentadiene, terpene, terpene-phenol resin and the like.

<Adhesive-imparting agent having an affinity with a block of a glass phase (for example, polymer block (A)) and / or a non-glass phase (for example, polymer block (B)) of a block copolymer>
From the viewpoint of high adhesive strength, suppression of change in adhesive strength over time, or creep performance (smaller value is better), the non-glass phase block of the block copolymer (usually, the smaller the value is, the better) is contained in the adhesive composition of the present embodiment. Contains 20 to 75% by mass of a tackifier having an affinity for the intermediate block) and 3 to 30% by mass of a tackifier having an affinity for the block (usually the outer block) of the glass phase of the block copolymer. It is more preferable to do so.
Here, the block copolymer means to include the above-mentioned components (a) and (b).

The tackifier having an affinity for the block of the glass phase of the block copolymer is not particularly limited, but for example, a resin having an aromatic ring between the molecules is preferable. Examples of such a resin include, but are not limited to, aromatic group-containing resins such as homopolymers or copolymers containing vinyltoluene, styrene, α-methylstyrene, kumaron, or indene as a constituent unit. Be done. Further, among these, Kristarex and Plastolin (manufactured by Eastman Chemical Company, trade name) 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 3 to 30% by mass, based on 100% by mass of the adhesive composition of the present embodiment. It is preferably 5 to 20% by mass, more preferably 6 to 12% by mass.

From the viewpoints of high initial adhesive strength, high wettability, low melt viscosity of the adhesive composition, high coatability, etc., a petroleum resin having an aroma content of 3 to 12% by mass should be used as the tackifier. Is preferable. Such petroleum resin is not particularly limited, and is, for example, an aliphatic petroleum hydrocarbon resin (C5 series resin), a hydrogenated derivative of an aliphatic petroleum hydrocarbon resin (C5 series resin), and an aromatic petroleum hydrocarbon resin (C5 series resin). C9-based resin), hydrogenated derivative of aromatic petroleum hydrocarbon resin (C9-based resin), dicyclopentadiene-based resin, hydrogenated derivative of dicyclopentadiene-based resin, C5 / C9 copolymer resin, C5 / C9 copolymer Examples thereof include a hydrogenated derivative of a system resin, a cyclic aliphatic petroleum hydrocarbon resin, and a hydrogenated derivative of a cyclic aliphatic petroleum hydrocarbon resin. The aroma content of the petroleum resin is preferably 3 to 12% by mass, more preferably 4 to 10% by mass. Of these, hydrogenated petroleum resin is particularly preferable.

In the adhesive composition of the present embodiment, the content of the tackifier is 1 to 250 parts by mass with respect to 100 parts by mass of the block copolymer composition described above, and the obtained adhesive composition is obtained. A wide variety of selections can be made within the range depending on the application and required performance of the object.

(Softener)
The "softener" refers to an adhesive composition having a function of lowering the hardness and lowering the viscosity. The softening agent is not particularly limited, and examples thereof include oils; plasticizers; synthetic liquid oligomers; and mixtures thereof.
Hereinafter, preferable softeners according to the application and performance will be described more specifically.

From the viewpoint of reducing the viscosity, improving the adhesiveness, and lowering the hardness of the adhesive composition of the present embodiment, oils can be used as the softening agent. The oils are not particularly limited, and examples thereof include known paraffin-based process oils, naphthen-based process oils, aroma-based process oils, and mixed oils thereof.

The plasticizer is not particularly limited, but is, for example, a liquid paraffin; a fatty acid composed of a higher fatty acid having 12 to 16 carbon atoms such as isopropyl myristate, ethyl laurate, and isopropyl palmitate and a lower monohydric alcohol having 1 to 4 carbon atoms. Esters; Fatty acids with 8 to 10 carbon atoms; Glycols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol; Fats and oils such as olive oil, castor oil, squalane, lanolin; ethyl acetate, ethyl alcohol , Dimethyldecylsulfoxide, decylmethylsulfoxide, dimethylsulfoxide, dimethylformamide, dimethylacetamide, dimethyllaurylamide, dodecylpyrrolidone, isosorbitol, oleyl alcohol, lauric acid and other organic solvents; liquid surfactants; ethoxylated stearyl alcohol, glycerin Examples thereof include esters, isotridecyl myristate, N-methylpyrrolidone, ethyl oleate, oleic acid, diisopropyl adipate, octyl palmitate, 1,3-propanediol, glycerin and the like.
Of these, compounds that are liquid at room temperature are used.
The plasticizer may be used alone or in combination of two or more.

Among the plasticizers, glycerin ester is preferable, and medium-chain fatty acid triglyceride, which is an ester of a fatty acid having 8 to 10 carbon atoms and glycerin, is more preferable. Examples of the medium-chain fatty acid triglyceride include tri (caprylic acid / capric acid) glyceryl.

When the adhesive tape using the adhesive composition of the present embodiment is used as a medical adhesive tape such as a taping tape, the plasticizer should be a combination of liquid paraffin and another liquid plasticizer. Is preferable.

When it is desired to soften the adhesive composition of the present embodiment, it is preferable to use a synthetic liquid oligomer as the softening agent from the viewpoint of improving the bleeding property. The synthetic liquid oligomer is not particularly limited, and examples thereof include styrene oligomers, butadiene oligomers, isoprene oligomers, butene oligomers, and the like.

The commercially available softener used in the adhesive composition of the present embodiment is not particularly limited, and for example, Diana Fresia S32 (trade name) and Diana Process Oil PW-90 (trade name) manufactured by Idemitsu Kosan Co., Ltd. , Process Oil NS100 (Product Name) Process Oil NS90S (Product Name), Kukdong Oil & Chem's White Oil Bloom350 (Product Name), DN Oil KP-68 (Product Name), BP Chemicals' Enerper M1930 (Product Name), Examples thereof include Kaydol (trade name) manufactured by Crompton, Primol 352 (trade name) manufactured by Esso, and KN4010 (trade name) manufactured by PetroChina Company.

(Other ingredients)
The adhesive composition of the present embodiment may contain, if necessary, an antioxidant, a polymer other than the components (a) and (b), a wax, a stabilizer such as a light stabilizer, and other additives. It may contain other components of.

<Antioxidant>
Antioxidants include, but are not limited to, 2,6-di-t-butyl-4-methylphenol, n-octadecyl-3- (4'-hydroxy-3', 5'-di-t. -Butylphenyl) propionate, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol), 2,4-bis [(octylthio) ) Methyl] -0-cresol, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenylacrylate, 2,4-di-t-amyl- 6- [1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl] phenyl acrylate, 2- [1- (2-hydroxy-3,5-di-tert-pentylphenyl)] acrylate, etc. Hindered phenolic antioxidants; sulfur-based antioxidants such as dilaurylthiodiprovionate, laurylstearylthiodipropionate pentaerythritol-tetrakis (β-laurylthiopropionate); tris (nonylphenyl) phosphite , Tris (2,4-di-t-butylphenyl) Phosphite and other phosphorus-based antioxidants and the like.

Commercially available products of antioxidants include, for example, Sumitomo Chemical Co., Ltd.'s Sumilyzer GM (trade name), Sumilyzer TPD (trade name) and Sumilyzer TPS (trade name), and Cibas Specialty Chemicals' Ilganox 1010. (Product name), Irganox HP2225FF (trade name), Irgafos 168 (trade name) and Irganox 1520 (trade name), JF77 (trade name) manufactured by Johoku Kagaku Co., Ltd. can be mentioned.
These stabilizers can be used alone or in combination of two or more.

The content of the antioxidant is arbitrary, but is preferably 5 parts by mass or less with respect to 100 parts by mass of the adhesive composition.

<Polymer other than component (a) and component (b)>
The polymer other than the component (a) and the component (b) is not particularly limited, and examples thereof include a polyolefin-based copolymer, a vinyl aromatic copolymer, and other rubbers. In addition, in this specification, "other than component (a) and component (b)" means that it does not correspond to any of component (a) and component (b).

The polyolefin-based copolymer is not particularly limited, and examples thereof include an atactic polyprovylene, an ethylene-ethyl acrylate copolymer, and an α-olefin-based polymer.

The vinyl aromatic copolymer is not particularly limited, and for example, a styrene-ethylene block copolymer, a styrene-butadiene block copolymer, a styrene-propylene block copolymer, and a styrene-isoprene block are used together. Polymers, styrene-butadiene-isoprene block copolymers, styrene-butadiene / isoprene block copolymers, hydrogenated styrene-butadiene block copolymers, hydrogenated styrene-isoprene block copolymers, hydrogenated styrene -Butadiene-isoprene-based block copolymers, hydrogenated styrene-butadiene / isoprene-based block copolymers, and the like, and examples thereof include polymers other than the component (a) and the component (b). The vinyl aromatic copolymer may be a vinyl aromatic thermoplastic resin or a vinyl aromatic elastomer.
The content of the vinyl aromatic copolymer other than the component (a) and the component (b) is 100 in total of the polymer other than the component (a) and the component (b) and the component (a) and the component (b). It is preferably 10 to 80 parts by mass, more preferably 10 to 70 parts by mass, still more preferably 10 to 60 parts by mass, and even more preferably 20 to 50 parts by mass with respect to parts by mass.

The other rubber is not particularly limited, and is, for example, natural rubber; isoprene-isoprene rubber, polyisoprene rubber, polybutadiene rubber, styrene-butadiene rubber, styrene-isoprene rubber, propylene-butylene rubber, ethylene-propylene rubber, chloroprene rubber, acrylic. Synthetic rubbers such as rubber, isoprene-isoprene rubber, and polypentenemar rubber can be mentioned.

Hereinafter, polymers other than the preferable components (a) and (b) according to the use and performance of the adhesive composition of the present embodiment will be described more specifically.

[Hydrogenated vinyl aromatic copolymer]
When it is necessary to reduce the adhesive residue when the adhesive composition of the present embodiment is peeled off, suppress the change in adhesive strength with time, or creep (the smaller the value is better), thermal stability, light resistance, etc. Can use a hydrogenated vinyl aromatic copolymer as the above-mentioned "polymer other than the component (a) and the component (b)".
The hydrogenated vinyl aromatic copolymer is not particularly limited, but is, for example, hydrogenated styrene-butadiene having a structure such as S-EB-S (S: polystyrene block, EB: ethylene / butylene copolymer block). Block-based block copolymer; hydrogenated styrene-isoprene-based block copolymer having a structure such as S-EP-S (S: polystyrene block, EP: ethylene / propylene copolymer block), or S-E-EP. Examples thereof include hydrogenated styrene-butadiene-isoprene block copolymers having a structure such as —S (S: polystyrene block, E: ethylene block, EP: ethylene / propylene copolymer block).

The styrene content of the hydrogenated vinyl aromatic copolymer is preferably 10% by mass to 45% by mass with respect to 100% by mass of the hydrogenated vinyl aromatic copolymer.
The hydrogenation rate of the unsaturated group in the conjugated diene in the hydrogenated vinyl aromatic copolymer is preferably 30 mol% or more, more preferably 50 mol% or more, still more preferably 70. It is mol% or more, and even more preferably 85 mol% or more.

[Isoprene-based block copolymer]
When the adhesive composition of the present embodiment requires high adhesiveness or suppression of gelation, a single amount of isoprene is used as the above-mentioned "polymer other than the component (a) and the component (b)". An isoprene-based block copolymer having a body unit can be used.
The isoprene-based block copolymer is not particularly limited, and is, for example, (SI) _n , (SI) _n -S, (SI) _n Y (S: polystyrene block, I: polyisoprene block). ) Etc.; (SIB) _n , (SIB) _n —S, (SIB) _n Y (S: polystyrene block, I :) Polyisoprene block, B: polybutadiene block, Y: residue of polyfunctional coupling agent or residue of polymerization initiator, n is an integer of 1 or more, preferably an integer of 1 to 5), or (SI. / B) _n , (SI / B) _n -S, (SI / B) _n Y (S: polystyrene block, I / B: isoprene / butadiene copolymer block, Y: residue of coupling agent Examples thereof include styrene-butadiene-isoprene block copolymers having a structure such as a group or a residue of a polymerization initiator, n is an integer of 1 or more, preferably an integer of 1 to 5). It is more preferable that these have a radial structure.

[Ionomer]
When the adhesive composition of the present embodiment requires high low-temperature coatability, creep (smaller value is better), high strength or high elongation, etc., the above-mentioned "component (a) and" A polymer other than the component (b) may be used in the state of an ionomer. The ionomer is not particularly limited, but for example, a homopolymer or a copolymer containing a carboxylate, a sulfonate or a phosphonate that is neutralized or partially neutralized by a metal ion is preferable. The content of ionomer is preferably 5% by mass or less with respect to the total amount of the adhesive composition.

[Polyolefin-based copolymer]
As the adhesive composition of the present embodiment, the amount of the tackifier in the high temperature storage stability, high elongation or block copolymer composition is reduced (55% by mass or less in the composition, further 45% by mass). When the following) and the like are required, a polyolefin-based copolymer can be used as the above-mentioned "polymer other than the component (a) and the component (b)".
The polyolefin-based copolymer is not particularly limited, but for example, a copolymer of α-olefin and olefin, or a propylene homopolymer is preferable. The melting point (condition: DSC measurement, 5 ° C./min) of these polymers is preferably 110 ° C. or lower, more preferably 100 ° C. or lower, and further preferably 60 ° C. to 90 ° C. These polymers may be thermoplastic resins or elastomers. The molecular weight distribution of these polymers is preferably 1 to 4, more preferably 1 to 3.

Further, from the viewpoint of processability, it is more preferable to use two or more kinds of copolymers using α-olefins or propylene homopolymers in combination. Specifically, it is preferable to use a polymer having a weight average molecular weight of 30,000 to 60,000 and a polymer having a weight average molecular weight of 60,000 to 90000 in combination, a polymer having a weight average molecular weight of 35,000 to 55,000, and a polymer having a weight average molecular weight of 60,000 to 80,000. It is more preferable to use the above polymer together. The liquid component (oil or the like) in the adhesive composition using these is preferably 20% by mass or more, more preferably 25% by mass or more.

[Conjugated diene rubber]
When the adhesive composition of the present embodiment is used as the composition of the adhesive tape to improve the self-backing adhesive force and the skin adhesive force, the above-mentioned "polymers other than the component (a) and the component (b)" are used. As a result, a conjugated diene-based rubber can be used.
The conjugated diene rubber is not particularly limited, and examples thereof include isoprene-isoprene rubber, polyisoprene rubber, polybutadiene rubber, styrene-butadiene rubber, styrene-isoprene rubber, and propylene-butylene rubber. Among these, polyisoprene rubber is more preferable from the viewpoint of high effect.
The content of the conjugated diene-based rubber is preferably 3% by mass or more and 25% by mass or less, more preferably 5% by mass or more and 20% by mass or less, still more preferably, with respect to the total amount of the adhesive composition. Is 5% by mass or more and 15% by mass or less.
When the content of the conjugated diene-based rubber is 3% by mass or more, the adhesive strength on the back surface and the adhesive strength on the skin tend to be further improved. Further, when the content of the conjugated diene rubber is 25% by mass or less, the cohesive force is further improved and the adhesive residue tends to be further suppressed.

[Olefin-based elastomer]
When elongation or the like is required as the adhesive composition of the present embodiment, it is preferable to use an olefin elastomer in combination as the above-mentioned "polymer other than the component (a) and the component (b)". ..
The olefin-based elastomer is not particularly limited, but for example, one having Tg at −10 ° C. or lower is preferable. Further, from the viewpoint of creep performance (smaller value is better), an olefin-based elastomer having a block is more preferable.

<Wax>
If necessary, the adhesive composition of the present embodiment may contain wax. The wax is not particularly limited, but for example, paraffin wax, microkristang wax, low molecular weight polyethylene wax and the like can be added.
If the adhesive composition requires a low melt viscosity, especially a low melt viscosity below 140 ° C, then at least one wax selected from paraffin waxes, microcrystalline waxes, and Fisher-Tropsch waxes. It is preferable to use them together.
The wax content is preferably 2 to 10% by mass, more preferably 5 to 10% by mass. The melting point of the wax is preferably 50 ° C. to 110 ° C., more preferably 65 ° C. to 110 ° C., still more preferably 70 ° C. to 110 ° C., and even more preferably 75 ° C. to 110 ° C. be. The softening point of the tackifier used in combination at this time is preferably 70 ° C. or higher, more preferably 80 ° C. or higher. At this time, the G'(measurement condition: 25 ° C., 10 rad / s) of the obtained adhesive composition is preferably 1 Mpa or less. The crystallization temperature of the adhesive composition is preferably 7 ° C. or lower.

<Light stabilizer>
The adhesive composition of the present embodiment may contain a light stabilizer, if necessary.
The light stabilizer is not particularly limited, and is, for example, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-t-butylphenyl) benzo. Benzotriazole-based UV absorbers such as triazole, 2- (2'-hydroxy-3', 5'-di-t-butylphenyl) -5-chlorobenzotriazole; benzophenone-based such as 2-hydroxy-4-methoxybenzophenone UV absorbers; hindered amine-based light stabilizers and the like can be mentioned.

<Fine particle filler>
The adhesive composition of the present embodiment may further contain a fine particle filler as another additive.
The fine particle filler may be any commonly used one, and is not particularly limited. The fine particle filler is not particularly limited, and examples thereof include mica, calcium carbonate, kaolin, talc, titanium oxide, diatomaceous earth, urea-based resin, styrene beads, calcined clay, and starch. These shapes are preferably spherical, and their dimensions (diameter in the case of spherical shape) are not particularly limited.

[Characteristics of adhesive composition]
The performance of the adhesive composition of the present embodiment can be measured according to the measurement conditions shown in the examples using the adhesive tape produced under the conditions shown in the examples described later.

[Manufacturing method of adhesive composition]
The adhesive composition of the present embodiment is prepared by mixing the above-mentioned block copolymer composition, a tackifier, a softening agent, and if necessary, other additives by a known method. Can be manufactured by
The mixing method is not particularly limited, and examples thereof include a method of uniformly mixing a block copolymer composition, a tackifier, and a softener with a mixer, a kneader, or the like while heating.
The temperature at the time of mixing is preferably 130 ° C. to 210 ° C., more preferably 135 ° C. to 200 ° C., and even more preferably 140 ° C. to 190 ° C. When the temperature at the time of mixing is 130 ° C. or higher, the block copolymer composition tends to be sufficiently melted and the dispersion tends to be good. Further, when the temperature at the time of mixing is 210 ° C. or lower, it tends to be possible to prevent evaporation of low molecular weight components of the cross-linking agent and the tackifier and deterioration of the adhesive property.
The mixing time is preferably 5 to 90 minutes, more preferably 10 to 80 minutes, and even more preferably 20 to 70 minutes. When the mixing time is 5 minutes or more, each component tends to be uniformly dispersed. Further, when the mixing time is 90 minutes or less, there is a tendency that evaporation of low molecular weight components of the cross-linking agent and the tackifier, deterioration of the adhesive property, and deterioration of the block copolymer can be prevented.

[How to apply the adhesive composition]
The method for applying the adhesive composition of the present embodiment is not particularly limited as long as the target product can be obtained. For example, the adhesive composition is dissolved in a solvent and coated with a solution. Examples thereof include a method of coating and a method of coating by a hot melt coating method in which the adhesive composition is melted and coated.
Among these, the hot melt coating method is preferable because of environmental pollution and ease of coating. The hot melt coating method is roughly classified into contact coating and non-contact coating. "Contact coating" refers to a coating method in which a ejector is brought into contact with a member or a film when applying a hot melt adhesive. Further, "non-contact coating" refers to a coating method in which the ejector is not brought into contact with a member or a film when the hot melt adhesive is applied. The contact coating method is not particularly limited, and examples thereof include die coater coating, slot coater coating, and roll coater coating. The non-contact coating method is not particularly limited, but is, for example, a spiral coating that can be applied in a spiral shape, an omega coating or a control seam coating that can be applied in a wavy shape, a slot spray coating that can be applied in a planar shape, or a curtain spray. Examples include coating, dot coating that can be applied in dots, and bead coating that can be applied on lines.

The pressure-sensitive adhesive composition of the present embodiment has good thermal stability, is uniformly melted in a high-temperature tank at 100 to 200 ° C., and does not undergo phase separation. On the other hand, in the hot melt adhesive having poor thermal stability, the components are easily phase-separated in the high temperature tank. Since the phase separation also causes clogging of the tank filter and the transportation pipe, the adhesive composition of the present embodiment has excellent properties from this viewpoint.

[Use]
Since the adhesive composition of the present embodiment has a low viscosity, it is easy to apply at a relatively low temperature and has a particularly excellent holding power. Taking advantage of these characteristics, various adhesive tapes / labels, pressure-sensitive thin plates, pressure-sensitive sheets, surface protection sheets / films, back glue for fixing various lightweight plastic molded products, back glue for fixing carpets, back glue for fixing tiles , Can be used as an adhesive or the like, and can be particularly preferably used as an adhesive for an adhesive tape.

Hereinafter, the present invention will be described in more detail with reference to specific examples and comparative examples, but the present invention is not limited to the following examples and comparative examples.
In the following Examples and Comparative Examples, the characteristics and physical properties of the polymer were measured by the following methods.

[(1): Characteristics of block copolymer composition]
((1-1) Content of vinyl aromatic compound monomer unit in block copolymer composition (hereinafter, also referred to as styrene content), hydrogen of vinyl bond of conjugated diene monomer unit before hydrogenation Addition rate, hydrogenation rate of unsaturated double bond in conjugated diene monomer unit (H))
The hydrogenation rate of the double bond of the conjugated diene monomer unit in the block copolymer composition was measured under the following conditions using a nuclear magnetic resonance apparatus (NMR).
First, by adding a large amount of methanol to the reaction solution after the hydrogenation reaction, the block copolymer constituting the block copolymer composition was precipitated and recovered. Next, the block copolymer was extracted with acetone, the extract was vacuum dried, and the conditions for ¹ H-NMR measurement used as a sample for ¹ H-NMR measurement are described below.
<Measurement conditions>
Measuring equipment: JNM-LA400 (manufactured by JEOL)
Solvent: Deuterated chloroform Measurement sample: Sample concentration before and after hydrogenation of polymer Sample concentration: 50 mg / mL
Observation frequency: 400MHz
Chemical shift criteria: TMS (tetramethylsilane)
Pulse delay: 2.904 seconds Number of scans: 64 times Pulse width: 45 °
Measurement temperature: 26 ° C

((1-2) Weight average molecular weight)
For the weight average molecular weights of the components (a) and (b) constituting the block copolymer composition, a calibration curve (peak molecular weight of standard polystyrene) obtained from the measurement of commercially available standard polystyrene is used based on the measurement conditions described later. Was created based on the molecular weight of the peak of the chromatogram.
First, the peak top molecular weight is the lowest in the range of molecular weight of 20,000 or more, and the area ratio calculated by the peak division described later is 0.1 or more with respect to the total peak area of the block copolymer composition. The peak was designated as the component (a), and all the peaks in the higher molecular weight range were designated as the component (b).
The weight average molecular weights of the components (a) and (b) were determined by vertical division to the baseline at the inflection between peaks of the GPC curve using the system software described later. Here, the inflection between the peaks of the component (a) and the component (b) is set to the lowest point (valley peak) which is the lowest in the vertical direction between the adjacent peaks. When the lowest points are continuous, they are set as the intermediate points. With the above-mentioned inflection points, vertical division was performed using the waveform separation function in the above-mentioned system software, and after the division, each weight average molecular weight and area ratio were calculated.
<Measurement conditions>
GPC; ACQUITY APC system (manufactured by Japan Waters Corp.)
System (measurement / analysis) software; Emper3
Detector; RI
Refractive index unit Shaking scale; 500 μRIU
Output full scale; 2000mV
Sampling rate; 10 points / sec
Column; ACQUITY APC XT125 (4.6 mm x 150 mm); 1
ACQUITY APC XT200 (4.6 mm x 150 mm); 1
ACQUITY APC XT900 (4.6 mm x 150 mm); 1
ACQUITY APC XT450 (4.6 mm x 150 mm); 1 solvent; THF
Flow rate; 1.0 mL / min Concentration: 0.1 mg / mL
Column temperature; 40 ° C
Injection volume; 20 μL

<Weight average molecular weight of the polymer block (A) contained in (1-3) component (a)>
The weight average molecular weight of the polymer block (A) contained in the component (a) was calculated from the values of the weight average molecular weight of the component (a) and the content of the vinyl aromatic monomer unit (styrene).

<Contents of component (a) and component (b) in (1-4) block copolymer composition>
The ratio of the area of the component (a) to the total peak area of the elution curve measured in (1-2) was defined as the content of the component (a).
Further, the ratio of the area of all the peaks in the molecular weight range in which the molecular weight is higher than that of the component (a) to the total peak area of the elution curve measured in (1-2) was defined as the content of the component (b).

<(1-5): Content of components (b-1), (b-2), and (b-3), weight average molecular weight>
In the component (b), the peak having a peak top 1.5 times or more and less than 2.5 times the weight average molecular weight of the component (a) is defined as the component (b-1), and the weight average molecular weight of the component (a). A peak having a peak top 2.5 times or more and less than 3.4 times is a peak having a peak of 3.4 times or more and less than 4.5 times the weight average molecular weight of the component (a). The peak with the top was defined as the component (b-3), and the ratio of the peak area of each component to the total peak area of the elution curve measured in (1-2) above was defined as the content of each component.
The peak area and weight average molecular weight of the component (b-1), the component (b-2) and the component (b-3), and the weight average molecular weight ratio are described above after GPC measurement under the above-mentioned equipment and conditions. It was obtained by vertical division to the baseline at the inflection between peaks of the GPC curve using the system software of.
Here, the inflection points between the peaks of the components (b-1), (b-2), and (b-3) are set to the lowest points (valley peaks) that are the lowest in the vertical direction between the adjacent peaks. When the lowest points are continuous, they are set as the intermediate points. With the above-mentioned inflection points, vertical division was performed using the waveform separation function in the above-mentioned system software, and after the division, each weight average molecular weight, each weight average molecular weight ratio, and the peak area were calculated.

<(1-6) Vinyl bond amount V before hydrogenation of conjugated diene monomer unit>
It was calculated by the Hampton method using a block copolymer composition before hydrogenation and an infrared spectrophotometer (FT / IR-230, manufactured by JASCO Corporation).

[(2) Measurement of physical properties of adhesive composition]
(Preparation of adhesive composition)
100 parts by mass of the block copolymer composition of each example and comparative example, 100 parts by mass of Quinton R100 (manufactured by Nippon Zeon Co., Ltd.) as a tackifier, and process oil NS-90S (Idemitsu Kosan Co., Ltd.) as a softener. ), And 1 part by mass of 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenylacrylate as a stabilizer are mixed. It was melt-kneaded with a pressure-type kneader (model: DR0.5-3MB-E, Moriyama Co., Ltd.) at 180 ° C., 50 rpm, and 30 minutes to obtain a uniform hot-melt type adhesive composition.

<Melting viscosity of adhesive composition>
The melt viscosity of the adhesive composition was measured at a temperature of 160 ° C. and 180 ° C. with a Brookfield type viscometer (DV-III manufactured by Brookfield Co., Ltd.).

(Making adhesive tape)
The melted adhesive composition was cooled to room temperature and dissolved in toluene to obtain a toluene solution.
The obtained toluene solution was coated on a polyester film with an applicator, and then held at room temperature for 30 minutes and in an oven at 70 ° C. for 7 minutes to completely evaporate the toluene to prepare an adhesive tape.
The coating thickness was 25 μm (base material thickness 38 μm).

<Adhesive properties of adhesive composition (1) (probe tack)>
Using the adhesive compositions of Examples 1 to 9 and Comparative Examples 1 to 12, adhesive tapes having a length of 30 mm and a width of 30 mm were prepared as described above.
The produced adhesive tape was attached to the top surface of a probe tack tester (NTS-4800 / manufactured by Tester Sangyo Co., Ltd.) with a load of 10 g (cylindrical) so that the adhesive surface faced downward.
A cylinder (made of SUS) having a diameter of 5 mmφ was adhered to the adhesive surface from below in a floating state for 1 second.
Then, the peeling force when the cylinder was peeled off was measured.
Adhesion and peeling speed was 10 mm / sec.

<Adhesive properties of adhesive composition (2) (adhesive strength)>
Using the adhesive compositions of Examples 1 to 9 and Comparative Examples 1 to 12, an adhesive tape having a width of 25 mm was prepared as described above.
The produced adhesive tape was attached to a SUS plate (SUS304), and the peeling force was measured at a peeling speed of 300 mm / min at 180 degrees.

<Adhesive properties of adhesive composition (3) (holding power)>
Using the adhesive compositions of Examples 1 to 9 and Comparative Examples 1 to 12, an adhesive tape having a width of 15 mm was prepared as described above.
The produced adhesive tape was attached to a SUS plate (SUS304) with a contact area of 15 mm × 15 mm.
Then, a load of 1 kg was applied to the adhesive tape in the vertical direction at 50 ° C., and the holding time until the adhesive tape slipped off was measured.
The holding power of each sample was determined based on the following criteria.

<Adhesive properties of adhesive composition (4) (balance between melt viscosity and adhesive performance)>
The balance between the melt viscosity and the adhesive performance was determined based on the value obtained by dividing the holding time (minutes) obtained above by the measured value (Pa · s) of the melt viscosity obtained above.

[Preparation of block copolymer composition]
(Preparation of hydrogenation catalyst)
In Examples and Comparative Examples described later, a hydrogenation catalyst used for producing a block copolymer composition was prepared by the following method.
A reaction vessel equipped with a stirrer was replaced with nitrogen, and 1 L of dried and purified cyclohexane was charged therein.
Next, 100 mmol of bis (η5-cyclopentadienyl) titanium dichloride was added. While sufficiently stirring this, an n-hexane solution containing 200 mmol of trimethylaluminum was added, and the mixture was reacted at room temperature for about 3 days.
As a result, a hydrogenation catalyst was obtained.

(Preparation of block copolymer composition)
<Example 1>
Batch polymerization was carried out by the following method using a stirrer having an internal volume of 100 L and a tank reactor with a jacket.
First, 36 L of cyclohexane was placed in the reactor, the temperature was adjusted to 55 ° C., and then n-butyl lithium (hereinafter referred to as n-butyl lithium) (hereinafter referred to as “all monomers”) with respect to 100 parts by mass of the total amount of butadiene monomer and styrene monomer charged into the reactor (hereinafter referred to as all monomers). Also referred to as "Bu-Li") 0.143 parts by mass and 0.28 mol of N, N, N', N'-tetramethylethylenediamine (hereinafter also referred to as "TMEDA") with respect to 1 mol of Bu-Li. Added.
Next, 24.0 parts by mass of styrene was added over 5 minutes and then reacted for another 15 minutes (reached 65 ° C. by the polymerization reaction). At this point, the polymer solution was sampled and the polymerization conversion rate of styrene was measured and found to be 100%.
Next, a cyclohexane solution (concentration: 40 parts by mass) containing 76.0 parts by mass of butadiene was continuously added to the reactor at a constant rate over 60 minutes, and then reacted for another 10 minutes, and the reaction temperature was 86, which is the maximum temperature. Three minutes after the temperature reached ° C., tetraethoxysilane was added as a coupling agent to a concentration of 0.114 per 1 mol of Bu-Li, and the coupling reaction was carried out for 30 minutes. Then, 0.6 mol of methanol was added to 1 mol of Bu-Li to terminate the polymerization reaction, and a block copolymer composition was obtained.
Next, 50 ppm of the hydrogenation catalyst was added as titanium per 100 parts by mass of the copolymer to the obtained block copolymer composition, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.9 MPa and a temperature of 90 ° C. for 45 minutes. rice field.
Then, as a stabilizer, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate was added in an amount of 0.3 parts by mass based on 100 parts by mass of the copolymer to form a block copolymer composition. I got 1.

<Example 2>
The block copolymer composition 2 was obtained in the same manner as in Example 1 except that the amount of styrene was changed to 25 parts by mass and the amount of butadiene was changed to 75 parts by mass.

<Example 3>
The block copolymer composition 3 was obtained in the same manner as in Example 1 except that the amount of styrene was changed to 23 parts by mass and the amount of butadiene was changed to 77 parts by mass.

<Example 4>
The block copolymer composition 4 was obtained in the same manner as in Example 1 except that Bu-Li was changed to 0.129 parts by mass with respect to 100 parts by mass of all the monomers.

<Example 5>
The block copolymer composition 5 was obtained in the same manner as in Example 1 except that Bu-Li was changed to 0.185 parts by mass with respect to 100 parts by mass of all the monomers.

<Example 6>
The block copolymer composition 6 was obtained in the same manner as in Example 1 except that the hydrogenation reaction time was changed to 60 minutes.

<Example 7>
The block copolymer composition 7 was obtained in the same manner as in Example 1 except that TMEDA was changed to 0.05 mol with respect to 1 mol of Bu-Li and the hydrogenation reaction time was changed to 30 minutes.

<Example 8>
The block copolymer composition 8 was similarly changed to Example 1 except that tetraethoxysilane was changed to 0.145 mol with respect to 1 mol of Bu-Li and methanol was changed to 0.5 mol with respect to 1 mol of Bu-Li. Got

<Example 9>
The block copolymer composition 9 was similarly changed to Example 1 except that tetraethoxysilane was changed to 0.097 mol to 1 mol of Bu-Li and methanol was changed to 0.7 mol to 1 mol of Bu-Li. Got

<Comparative Example 1>
Changed the amount of Bu-Li to 0.112 parts by mass, the amount of styrene to 22 parts by mass, the amount of butadiene to 78 parts by mass, and the amount of tetraethoxysilane to 0.126 mol to 1 mol of Bu-Li with respect to 100 parts by mass of all the monomers. The block copolymer composition 10 was obtained in the same manner as in Example 1.

<Comparative Example 2>
0.112 parts by mass of Bu-Li, 26 parts by mass of styrene, 74 parts by mass of butadiene, 0.138 mol of tetraethoxysilane per 1 mol of Bu-Li, coupling with respect to 100 parts by mass of all monomers. The block copolymer composition 11 was obtained in the same manner as in Example 1 except that the reaction time was changed to 15 minutes.

<Comparative Example 3>
0.2 mol of TMEDA with respect to 1 mol of Bu-Li, 25 parts by mass of styrene, 75 parts by mass of butadiene, 0.152 mol of tetraethoxysilane with respect to 1 mol of Bu-Li, maximum temperature during butadiene reaction The block copolymer composition 12 was obtained in the same manner as in Example 1 except that the temperature was changed to 75 ° C. by cooling the reactor.

<Comparative Example 4>
The block copolymer composition was the same as in Example 1 except that Bu-Li was changed to 0.138 parts by mass, styrene amount was changed to 28 parts by mass, and butadiene amount was changed to 72 parts by mass with respect to 100 parts by mass of all the monomers. I got the thing 13.

<Comparative Example 5>
The block copolymer composition was the same as in Example 1 except that Bu-Li was changed to 0.150 parts by mass, styrene amount was changed to 17 parts by mass, and butadiene amount was changed to 83 parts by mass with respect to 100 parts by mass of all the monomers. I got a thing 14.

<Comparative Example 6>
The block copolymer composition 15 was obtained in the same manner as in Example 1 except that Bu-Li was changed to 0.109 parts by mass with respect to 100 parts by mass of all the monomers.

<Comparative Example 7>
A block copolymer composition 16 was obtained in the same manner as in Example 1 except that Bu-Li was changed to 0.226 parts by mass with respect to 100 parts by mass of all the monomers.

<Comparative Example 8>
The block copolymer composition 17 was obtained in the same manner as in Example 1 except that the hydrogenation reaction time was changed to 90 minutes.

<Comparative Example 9>
The block copolymer composition 18 was obtained in the same manner as in Example 1 except that the hydrogenation reaction time was changed to 30 minutes.

<Comparative Example 10>
Block copolymer composition 19 in the same manner as in Example 1 except that tetraethoxysilane was changed to 0.059 mol with respect to 1 mol of Bu-Li and methanol was changed to 0.8 mol with respect to 1 mol of Bu-Li. Got

<Comparative Example 11>
The block copolymer composition 20 is the same as in Example 1 except that tetraethoxysilane is changed to 0.178 mol with respect to 1 mol of Bu-Li and methanol is changed to 0.4 mol with respect to 1 mol of Bu-Li. Got

<Comparative Example 12>
Except for changing the amount of Bu-Li to 0.109 parts by mass, the coupling agent to ethyl benzoate, and the amount of the coupling agent to be added to 0.193 mol to 1 mol of Bu-Li with respect to 100 parts by mass of all the monomers. , The block copolymer composition 21 was obtained in the same manner as in Example 1.

The physical characteristic values of the obtained Examples 1 to 9 and Comparative Examples 1 to 12 are shown in Tables 1 and 2.
The characteristics of Examples 1 to 9 and Comparative Examples 1 to 12 obtained as described above were evaluated by the above method.
Further, an adhesive tape was obtained by the above-mentioned method for producing an adhesive tape. The obtained adhesive tape was evaluated by the above method.
The evaluation results are shown in Tables 1 and 2.

In the above evaluation, the value obtained by dividing the holding time by the melt viscosity at 180 ° C. is calculated as the balance between the melt viscosity and the adhesive performance, and the value of 2.0 or more is the balance between the low viscosity and the holding power performance. It was judged to be an excellent block copolymer composition and a viscous adhesive composition.

The block copolymer composition and the adhesive adhesive composition of the present invention have industrial applicability as materials for solution-type and hot-melt type adhesives and adhesives.

Claims (4)

Component (a) is 50% by mass or more and 70% by mass or less,
A block copolymer composition containing the component (b) in an amount of 30% by mass or more and 50% by mass or less.
The component (a) comprises a polymer block (A) mainly composed of one vinyl aromatic monomer unit and a polymer block (B) mainly composed of at least one conjugated diene monomer unit. It is a block copolymer contained and having a weight average molecular weight of 50,000 or more and 80,000 or less.
The component (b) comprises a polymer block (A) mainly composed of at least two vinyl aromatic monomer units and a polymer block (B) mainly composed of at least one conjugated diene monomer unit. It is a block copolymer containing
The component (b) is a polymer obtained by coupling the component (a) with a coupling agent having a tetrafunctionality or higher.
The component (b) is a component (b-1) in which the weight average molecular weight ratio of the component (a) to the weight average molecular weight is 1.5 or more and less than 2.5, and the weight of the component (a) with respect to the weight average molecular weight. The component (b-2) having an average molecular weight ratio of 2.5 or more and less than 3.4, and the component (b) having a weight average molecular weight ratio of 3.4 or more and less than 4.5 to the weight average molecular weight of the component (a). -3) including
The content of the component (b-3) is 35% by mass or more with respect to the entire component (b).
The content of the vinyl aromatic monomer unit in the component (a) and the component (b) is 22.0% by mass or more with respect to the total amount of the component (a) and the component (b) 26. It is 0% by mass or less,
The vinyl bond amount V (%) of the conjugated diene monomer unit of the component (a) and the component (b) before hydrogenation is 25% or more.
The hydrogenation rate H (%) of the unsaturated double bond of the conjugated diene monomer unit possessed by the component (a) and the component (b) is as follows in relation to the vinyl bond amount V (%). Satisfy equation (1)
The hydrogenation rate of the vinyl bond of the conjugated diene monomer unit of the component (a) and the component (b) before hydrogenation is 80% or more.
Block copolymer composition.
V + 50>H> V + 10 ... Equation (1) The weight average molecular weight of the polymer block (A) contained in the component (a) is 14,000 or more and 19,000 or less.
The block copolymer composition according to claim 1. The component (a) is a block copolymer represented by (AB) and / or (AB) X.
The component (b-1) is (AB) ₂ X,
The component (b-2) is (AB) _3X ,
The component (b-3) is a block copolymer represented by (AB) _4X , respectively.
The block copolymer composition according to claim 1 or 2.
(A indicates a polymer block (A), B indicates a polymer block (B), and X indicates a residue of a coupling agent or a residue of a polymerization initiator.) 100 parts by mass of the block copolymer composition according to any one of claims 1 to 3.
1 to 250 parts by mass of adhesive,
Softener 0 to 120 parts by mass and
, A viscous adhesive composition.

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