JP5620067B2 - Adhesive composition, method for producing adhesive composition, and surface protective film using the same - Google Patents

Description

  The present invention relates to a composition for an adhesive, a method for producing an adhesive composition, and a surface protective film using the same.

Conventionally, rubber pressure-sensitive adhesives mainly composed of rubbers such as acrylic pressure-sensitive adhesives, natural rubber, and polyisobutylene have been mainly used as pressure-sensitive adhesives for surface protecting pressure-sensitive adhesive films.
When these pressure-sensitive adhesives are applied to a predetermined support film, a method of applying a pressure-sensitive adhesive solution obtained by dissolving the pressure-sensitive adhesive in a solvent using a roll, a spray or the like has been employed.
This method has the advantage that the pressure-sensitive adhesive layer can be applied uniformly and thinly, but the use of a solvent is preferable from the viewpoint of air pollution, fire, safety and hygiene at the time of production, economy, etc. Absent.
As a hot-melt type manufacturing technology that does not use a solvent, a technology for manufacturing a laminate of a pressure-sensitive adhesive layer and a support film by coextrusion is known, and various hot-melt type materials have also been proposed for pressure-sensitive adhesives. (For example, refer to Patent Document 1).

  Moreover, as an adhesive having excellent adhesive strength, it consists of a block mainly composed of vinyl aromatic compound and a block mainly composed of conjugated diene, and hydrogenates part of the double bond of the conjugated diene part, and the rest An adhesive composition comprising an epoxy-modified hydrogenated block copolymer obtained by epoxidizing a part of a double bond has been proposed (see, for example, Patent Document 2).

  When an olefin resin film, which is a representative of difficult-to-adhere materials, is used as the base film, an ethylene-based copolymer having a high affinity with the olefin resin film, such as EVA, is used as an adhesive layer. A coextruded film is proposed (see Patent Document 3).

Japanese Patent No. 4115791 JP-A-8-73699 Japanese Patent Publication No.7-116410

However, as in Patent Document 1, in the technique for producing a laminate of a pressure-sensitive adhesive layer and a support film by coextrusion, it is an effective means for increasing the adhesive force between the support film and the pressure-sensitive adhesive layer. Since it is difficult to perform corona treatment, alkali treatment, flame treatment and the like, there is a problem that it is difficult to obtain a coextruded film having a strong adhesive force.
Specifically, when the laminate of the support film and the pressure-sensitive adhesive layer is attached to a metal plate or the like, there is a problem in that interfacial peeling occurs between the support film and the pressure-sensitive adhesive layer, and adhesive residue occurs. is there.

  In addition, the adhesive composition disclosed in Patent Document 2 is severely gelled or deteriorated by heating or long-term storage, and has a problem regarding long-term stability.

  Further, the coextruded film disclosed in Patent Document 3 has a problem that sufficient tackiness cannot be obtained for a film having a very low vinyl acetate content.

  Further, in Patent Document 3, for example, a pressure-sensitive adhesive layer using an ABA (A is a styrene polymer block and B is an ethylene / butylene copolymer block) block copolymer is provided on an olefin resin film. Although the adhesive film for surface protection formed on the surface is also disclosed, such an adhesive has good adhesion when the adherend is distorted or has a complicated shape. On the other hand, when it is attached to a smooth adherend, the adhesive strength changes due to long-term storage, and there is a problem that adhesive residue is generated when the film is peeled off.

  Therefore, in the present invention, the solution viscosity and the melt viscosity are low, and when applied to the base film, it can be easily applied, and when it is an extruded film, an excellent workability that a uniform film can be formed is obtained. Excellent adhesiveness is obtained even if the surface of the adherend is uneven, and even if it is peeled off after a long time after sticking, it has good peelability and no adhesive residue. An object is to provide an agent composition.

As a result of intensive studies to solve the above problems, the present inventors have a specific vinyl aromatic content and a specific vinyl aromatic polymer block content, and a conjugate having a specific hydrogenation rate. Adhesive composition containing a diene copolymer has low solution viscosity and melt viscosity when dissolved in a predetermined solvent, excellent workability, and good for the shape of the adherend The present invention has been completed by finding a self-adhesive composition that exhibits excellent adhesiveness and does not produce adhesive residue even after peeling for a long time.
That is, this invention provides the following compositions for adhesives.

[1] Mainly composed of a vinyl aromatic unit and a conjugated diene unit,
(A) The content of the vinyl aromatic unit exceeds 60% by mass and is 90 % by mass or less,
(B) The content of the vinyl aromatic polymer block is 30% by mass or less,
(C) the hydrogenation rate to the double bond based on conjugated diene is less than 70%,
(D) The weight average molecular weight is 5 × 10 ^{4 to} 100 × 10 ^4.
An adhesive composition comprising the hydrogenated block copolymer (A) is provided.
[2]
Mainly composed of vinyl aromatic units and conjugated diene units,
(A) The content of vinyl aromatic units exceeds 60% by mass and is 90% by mass or less,
(B) The content of the vinyl aromatic polymer block is 30% by mass or less,
(C) the hydrogenation rate to the double bond based on conjugated diene is less than 70%,
(D) The weight average molecular weight is 5 × 10 ^{4 to} 100 × 10 ^4.
10% to 80% by mass of the hydrogenated block copolymer (A),
(B) 20% to 90% by mass of hydrogenated styrene elastomer,
Is provided.
[3]
Mainly composed of vinyl aromatic units and conjugated diene units,
(A) The content of vinyl aromatic units exceeds 60% by mass and is 90% by mass or less,
(B) The content of the vinyl aromatic polymer block is 30% by mass or less,
(C) the hydrogenation rate to the double bond based on conjugated diene is less than 70%,
(D) The weight average molecular weight is 5 × 10 ^{4 to} 100 × 10 ^4.
A hydrogenated block copolymer (A),
(C) a tackifier,
Is provided.

[4]
The vinyl bond amount of the conjugated diene portion before hydrogenation of the (B) hydrogenated styrene elastomer is 5
The adhesive composition according to the above [2], which is 0 mol% or more.
[5]
The adhesive composition according to any one of [2] to [4], further including one or more thermoplastic resins.
[6]
(C) The adhesive composition according to [2] or [4], further including a tackifier resin.
[7]
The adhesive composition according to [2], further including one or more thermoplastic resins and (C) a tackifier resin.
[8]
The hydrogenated block copolymer (A), any one of said at least one perforated hydrogenated copolymer block (S) composed mainly of a vinyl aromatic unit and a conjugated diene unit [1] to [7] The adhesive composition described in 1. is provided.

[9]
The adhesive composition according to any one of [1] to [8], wherein a hydrogenation rate of the hydrogenated block copolymer (A) to a double bond based on a conjugated diene is 65% or less. Offer things.

[10]
The hydrogenated copolymer block (S) is a segment vinyl aromatic compound content is different has two or more, either the difference between the vinyl aromatic compound content in the two segments is 5% by mass or more the The adhesive composition according to [8] or [9] is provided.

[11]
The hydrogenated block copolymer (A), the difference in the vinyl aromatic compound content is not less 5% by mass or more, in any one of [1] to [10] containing two segments adjacent to each other The described adhesive compositions are provided.

[12]
The segment having a different vinyl aromatic compound content is a segment (S1) of a monomer composition having a vinyl aromatic compound content of 25 to 55% by mass, and a vinyl aromatic compound content of 55 to 80% by mass. [10] or [11] including a segment (S2) of a certain monomer composition, wherein (S1) and (S2) are each 30% by mass or more based on the copolymer block (S). ] The adhesive composition as described in the above is provided.

[13]
A method for producing the adhesive composition according to any one of [1] to [12] ,
A block copolymer before hydrogenation of the hydrogenated block copolymer (A), comprising a step of polymerizing the block copolymer by living anion polymerization before hydrogenation; In the polymerization step, the step of polymerizing by grading the ratio of the vinyl aromatic compound and the conjugated diene or by dividing the copolymer having a different ratio of the vinyl aromatic compound and the conjugated diene into two or more stages. The manufacturing method of the adhesive composition containing is provided.

[14]
In the step of polymerizing the block copolymer before the hydrogenation of the hydrogenated block copolymer (A) by living anion polymerization, the vinyl aromatic compound and the conjugated diene are combined with each other. Unlike the composition of the first copolymer (M1), the first copolymer (M1) having a content of 25 to 55% by mass has a vinyl aromatic compound content different from the polymerization step. The method for producing an adhesive composition according to the above [13] , wherein the second copolymer (M2) of 55 to 80% by mass is polymerized by a polymerization step in addition to the polymerization tank.

[15]
[14] The difference in vinyl aromatic compound content between the first copolymer (M1) and the second copolymer (M2) is 5% by mass or more and 30% by mass or less. A method for producing an adhesive composition is provided.

[16]
The adhesive composition according to any one of [1] to [12] , wherein the hydrogenated block copolymer (A) has a functional group.

[17]
A surface protective film in which one or more layers of the adhesive composition according to any one of [1] to [12] and [16] having a thickness of 1 μm to 100 μm are provided on a base film. I will provide a.

  According to the present invention, an adhesive composition having good processability, excellent adhesion to an adherend surface, suitable adhesive strength, and no adhesive residue even when peeled after adhesion for a long time. , A method for producing the adhesive composition, and a surface protective film using the adhesive composition.

  Hereinafter, although the form (henceforth this embodiment) for carrying out the present invention is explained, the present invention is not limited to the form shown below.

[Adhesive composition]
The adhesive composition of the present embodiment is mainly composed of a vinyl aromatic unit and a conjugated diene unit. (A) The content of the vinyl aromatic unit exceeds 35% by mass and is 90% by mass or less,
(B) The content of the vinyl aromatic polymer block is 40% by mass or less,
(C) the hydrogenation rate to the double bond based on conjugated diene is less than 70%,
(D) The weight average molecular weight is 5 × 10 ^{4 to} 100 × 10 ^4.
It is the adhesive composition containing the hydrogenated block copolymer (A) which is.

(Hydrogenated block copolymer (A))
In the hydrogenated block copolymer (A), examples of the vinyl aromatic monomer component include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N, N. -Dimethyl-p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene and the like. These may be used alone or in combination of two or more.
The content of the vinyl aromatic unit in the hydrogenated block copolymer (A) is intended to prevent adhesive residue when the adhesive composition in the present embodiment is pasted and left for a long time and then peeled off. From a viewpoint, it shall be over 35 mass%, and shall be 90 mass% or less from a viewpoint of obtaining favorable adhesiveness (requirement of said (a)).
The content of the vinyl aromatic unit in the hydrogenated block copolymer (A) is preferably more than 50% by mass and preferably 90% by mass or less, more preferably more than 55% by mass and 88% by mass or less, and more preferably 60% by mass. More than 86 mass% is more preferable.

The content of the vinyl aromatic polymer block in the hydrogenated block copolymer (A) needs to be 40% by mass or less from the viewpoint of obtaining good adhesion (requirement of the above (b)).
Moreover, it is 1 mass% or more from the viewpoint of securing practically good manufacturability and preventing adhesive residue when bonded and peeled after a long time, and from the viewpoint of obtaining practically sufficient adhesive strength. preferable.
When the content of the vinyl aromatic polymer block in the hydrogenated block copolymer (A) is less than 1% by mass, the hydrogenated block copolymer (A) is maintained in a granular form because the tackiness is too high. This makes it impossible to adhere the grains to each other, making it impossible to feed the hydrogenated block copolymer (A) quantitatively. Therefore, it becomes difficult to produce a surface protective film by a coextrusion method.
The content of the vinyl aromatic polymer block in the hydrogenated block copolymer (A) is more preferably from 5 to 35 mass%, further preferably from 10 to 30 mass%.

Here, the content of the vinyl aromatic polymer block in the hydrogenated block copolymer (A) is a method of oxidatively decomposing the copolymer before hydrogenation with tertiary butyl hydroperoxide using osmium tetroxide as a catalyst. (The method described in I.M.KOLTHOFF, et al., J. Polym. Sci. 1, 429 (1946), hereinafter also referred to as “the osmium tetroxide method”) of the vinyl aromatic polymer block obtained Using the weight (however, the vinyl aromatic polymer having an average degree of polymerization of about 30 or less is excluded), it is defined by the following formula.
Content of vinyl aromatic polymer block (% by mass)
= (Weight of vinyl aromatic polymer block in copolymer before hydrogenation / Weight of copolymer before hydrogenation) × 100

In the hydrogenated block copolymer (A), the conjugated diene as a monomer component refers to a diolefin having a pair of conjugated double bonds.
For example, 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1 , 3-hexadiene and the like. Particularly common are 1,3-butadiene and isoprene. These may be used alone or in combination of two or more.
In the adhesive composition in the present embodiment, 1,3-butadiene is preferably used as a main component from the viewpoint of obtaining good adhesive strength.
Specifically, the 1,3-butadiene content in the conjugated diene is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more.
The conjugated diene content in the hydrogenated block copolymer (A) is preferably more than 10% by mass and 65% by mass or less.

In the hydrogenated block copolymer (A), the microstructure of the conjugated diene moiety in the copolymer before hydrogenation (ratio of cis, trans, vinyl bond) is determined by the use of a polar compound such as a vinyl bond amount adjusting agent described later. There are no particular restrictions.
In terms of manufacturability, the vinyl bond content based on the conjugated diene is preferably 5% or more, and preferably 80% or less from the viewpoint of obtaining good adhesive strength in the adhesive composition of this embodiment. The range of 60% or less is more preferable, and the range of 15% or more and 40% or less is more preferable.
The vinyl bond content based on the conjugated diene is usually 8% or more and at least 5% or more, and it is substantially difficult to reduce the vinyl bond content to less than 5%.
The vinyl bond content based on the conjugated diene in the hydrogenated block copolymer (A) can be measured using a nuclear magnetic resonance apparatus (NMR).

In the hydrogenated block copolymer (A), the hydrogenation rate to the double bond based on the conjugated diene is less than 70% (requirement for the above (c)).
Thereby, in the adhesive composition of this embodiment, favorable adhesiveness and the outstanding adhesive strength are obtained.
In addition, from the viewpoint of reducing the adhesive residue when peeled after being stored for a long time after pasting, the hydrogenation rate to the double bond based on the conjugated diene is preferably 5% or more and 5% or more and less than 65%. The range is more preferable, the range of 10% or more and less than 60% is more preferable, and the range of 15% or more and less than 50% is even more preferable.
The hydrogenation rate of the hydrogenated block copolymer can be measured using a nuclear magnetic resonance apparatus (NMR).

The weight average molecular weight of the hydrogenated block copolymer (A) is sufficient for practical use from the viewpoint of reducing the adhesive residue when the adhesive composition in the present embodiment is bonded and peeled after long-term storage. From the viewpoint of obtaining adhesive strength, it is assumed to be 5 × 10 ⁴ or more. From the viewpoint of preventing an excessive burden on the extruder when forming a surface protective film by co-extrusion, that is, 100 × 10 4 It shall be ⁴ or less (requirement (d) above).
The weight average molecular weight of the hydrogenated block copolymer (A) is more preferably in the range of 8 × 10 ⁴ to 80 × 10 ⁴ , further preferably in the range of 10 × 10 ⁴ to 50 × 10 ⁴ , and 13 × 10 ⁴ to A range of 30 × 10 ⁴ is even more preferred.

The molecular weight distribution of the hydrogenated block copolymer (A) is preferably 1.01 to 6, and preferably 1.03 to 5 from the viewpoint of moldability.
The weight average molecular weight and molecular weight distribution of the hydrogenated block copolymer (A) were measured by gel permeation chromatography (apparatus: LC-10 (manufactured by Shimadzu Corporation, trade name), column: TSKgelGMHXL (4.6 mm ID × 30 cm). The molecular weight can be determined from the polystyrene-equivalent molecular weight using two solvents (solvent: tetrahydrofuran).

 The melt flow rate of the hydrogenated block copolymer (A) (JIS K-7210: 190 ° C., 2.16 Kg load) is a good residue of paste when it is peeled off after being bonded and stored for a long time. From the standpoint of preventing adhesion and obtaining practically sufficient adhesive strength, it is preferably 0.01 or more and 60 or less (measurement unit: g / 10 minutes), more preferably 0.1 or more and 40 or less, It is more preferably 0.5 or more and 35 or less, and even more preferably 1.5 or more and 35 or less.

The structure of the hydrogenated block copolymer (A) is not particularly limited, but a hydrogenated copolymer having at least one structure selected from the following general formulas (1) to (13) is preferable. .
(1) HS
(2) S-H-S
(3) (HS) _m -X
(4) (HS) _n -X- (H) _p
(5) (HS) _n -H
(6) H- (SE) _n
(7) H- (ES) _n
(8) E- (SH) _n -S
(9) H- (ES) _n -H
(10) (ESH) _m- X
(11) (HES) _m -X
(12) (HSE) _m -X
(13) (HEESE) _m -X

S in the general formulas (1) to (13) is a copolymer block of a conjugated diene and a vinyl aromatic (hydrogenated copolymer block (S) mainly composed of a vinyl aromatic unit and a conjugated diene unit). It is.
H is a polymer block mainly composed of vinyl aromatic.
E is a polymer block mainly composed of a conjugated diene.
In the present specification, “mainly” means that the copolymer contains monomer units of 60% by mass or more, preferably 80% by mass or more, preferably 90% by mass. It is more preferable to contain above, and it is further more preferable to contain 95 mass% or more.
In general formulas (1) to (13), m is an integer of 2 or more, and is preferably an integer of 2 or more and 10 or less.
n and p are integers of 1 or more, preferably 1 or more and 10 or less.
X represents a coupling agent residue or a polyfunctional initiator residue.

In the general formulas (1) to (13), the distribution of the vinyl aromatic in the hydrogenated copolymer block (S) mainly composed of the vinyl aromatic unit and the conjugated diene unit is the content of the vinyl aromatic compound. If it is the range of this, it will not be limited, and even if it distributes uniformly, you may distribute in taper shape, step shape, convex shape, or concave shape.
In addition, a crystal part may be present in the polymer block.

In the hydrogenated copolymer block (S) mainly composed of each vinyl aromatic unit and conjugated diene unit, a plurality of segments having different vinyl aromatic contents may coexist.
Here, the segment means a unit of a polymer chain having a substantially constant vinyl aromatic compound content in the hydrogenated copolymer block (S) mainly composed of a vinyl aromatic unit and a conjugated diene unit, Preferably, it means a unit of a polymer chain whose vinyl aromatic compound content change is less than 5% by mass.
Such a segment can be formed by supplying and polymerizing a vinyl aromatic compound and a conjugated diene at a constant ratio. Further, when the supply ratio of the vinyl aromatic compound and the conjugated diene is continuously changed, it can be regarded as another segment when the content of the vinyl aromatic compound in the polymer chain is changed by 5% by mass or more. Here, the vinyl aromatic compound content in the segment is an average value in the segment.

The content of the vinyl aromatic compound in the hydrogenated copolymer block (S) mainly composed of vinyl aromatic units and conjugated diene units is the same as that of the hydrogenated copolymer block (S) mainly composed of vinyl aromatic units and conjugated diene units. ), The individual copolymers with different polymerization addition rates extracted from the polymerization tank a number of times during the polymerization are analyzed by nuclear magnetic resonance spectrum (NMR).
The vinyl aromatic compound content in the hydrogenated copolymer block (S) mainly composed of vinyl aromatic units and conjugated diene units is an average value at a predetermined polymerization addition rate.
The hydrogenated copolymer block (S) mainly composed of a vinyl aromatic unit and a conjugated diene unit is composed of a copolymer mainly composed of a vinyl aromatic compound and a conjugated diene, and has a vinyl aromatic compound content. Including the two adjacent segments having a difference of 5% by mass or more reduces the adhesive residue when peeled off after long-term storage after bonding in the adhesive composition of the present embodiment. Sufficient adhesive strength is preferable from the viewpoint of realizing both properties in a balanced manner.

The segment having a different vinyl aromatic compound content is a segment (S1) of a monomer composition having a vinyl aromatic compound content of 25 to 55% by mass, and a vinyl aromatic compound content of 55 to 80% by mass. A segment (S2) having a certain monomer composition, and the (S1) and (S2) are respectively for the hydrogenated copolymer block (S) mainly composed of the vinyl aromatic unit and the conjugated diene unit. In the adhesive composition according to the present embodiment, it is 30% by mass or more to prevent adhesive residue when peeled off after a long period of time from pasting, to obtain a practically sufficient adhesive strength, It is preferable for realizing the characteristics in a balanced manner.
In the copolymer used for the adhesive composition of the present embodiment, the distribution of hydrogenation of double bonds based on the conjugated diene compound is not particularly limited. Depending on necessity such as adhesive strength, many double bonds based on the conjugated diene compound may exist in one or more molecular terminal block portions of the copolymer.

As the hydrogenated block copolymer (A), a modified hydrogenated block copolymer in which at least one atomic group having a functional group is bonded may be used. Moreover, you may use a modified | denatured hydrogenated block copolymer as a part of hydrogenated block copolymer (A).
Examples of the atomic group having a functional group include a hydroxyl group, a carboxyl group, a carbonyl group, a thiocarbonyl group, an acid halide group, an acid anhydride group, a thiocarboxylic acid group, an aldehyde group, a thioaldehyde group, a carboxylic acid ester group, and an amide. Group, sulfonic acid group, sulfonic acid ester group, phosphoric acid group, phosphoric acid ester group, amino group, imino group, nitrile group, pyridyl group, quinoline group, epoxy group, thioepoxy group, sulfide group, isocyanate group, isothiocyanate group , An atomic group containing at least one functional group selected from a halogenated silicon group, an alkoxysilicon group, a tin halide group, an alkoxytin group, a phenyltin group, and the like.

In the production of the modified hydrogenated block copolymer, an atomic group having a functional group may be formed, or a predetermined modifier compound containing a functional group may be used.
Further, a secondary modified hydrogenated block copolymer obtained by reacting a modified hydrogenated block copolymer with a secondary modifier having reactivity with the functional group of the modified hydrogenated block copolymer may be used. . A secondary modified hydrogenated block copolymer may be used as a part of the modified hydrogenated block copolymer.

[Method for producing adhesive composition]
The method for producing an adhesive composition in the present embodiment includes a step of polymerizing the block copolymer by living anionic polymerization before hydrogenation of the hydrogenated block copolymer (A). In the polymerization step of the block copolymer before hydrogenation of the polymer (A), the ratio between the vinyl aromatic compound and the conjugated diene is inclined, or the ratio between the vinyl aromatic compound and the conjugated diene is different. The polymer mixture is divided into two or more stages and polymerized.
The polymerization step can be performed using a polymerization initiator in a hydrocarbon solvent.

(solvent)
Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as n-butane, isobutane, n-pentane, n-hexane, n-heptane, and n-octane; cyclopentane, cyclohexane, cycloheptane, methylcycloheptane, and the like. And aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene.

(Polymerization initiator)
As the polymerization initiator, it is possible to use organic alkali metal compounds that are generally known to have anionic polymerization activity for conjugated dienes and vinyl aromatics. Examples thereof include aliphatic hydrocarbon alkali metal compounds, aromatic hydrocarbon alkali metal compounds, and organic amino alkali metal compounds.
Examples of the alkali metal include lithium, sodium, potassium, and the like. Suitable organic alkali metal compounds include aliphatic and aromatic hydrocarbon lithium compounds having 1 to 20 carbon atoms, and a plurality of lithium atoms in one molecule. Examples include dilithium compounds, trilithium compounds, and tetralithium compounds.
For example, n-propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, a reaction product of diisopropenylbenzene and sec-butyllithium, and divinylbenzene and sec-butyllithium with a small amount of 1, Examples include reaction products with 3-butadiene. Furthermore, organic alkali metal compounds disclosed in US Pat. No. 5,708,092, British Patent 2,241,239, US Pat. No. 5,527,753, etc. can also be used. .

(Vinyl amount adjusting agent)
In the step of polymerizing the block copolymer by living anion polymerization before hydrogenation of the hydrogenated block copolymer (A), when an organic alkali metal compound is used as a polymerization initiator, the vinyl bond based on the conjugated diene In order to increase the content, a tertiary amine compound, an ether compound, an alkali metal alkoxy compound or the like may be added as a vinyl amount adjusting agent.

Such tertiary amine compounds include those represented by the general formula R ₁ R ₂ R ₃ N (wherein R ₁ , R ₂ and R ₃ are each independently a hydrocarbon group having 1 to 20 carbon atoms, secondary amino Group or a hydrocarbon group having a tertiary amino group). For example, trimethylamine, triethylamine, tributylamine, N, N-dimethylaniline, N-ethylpiperidine, N-methylpyrrolidine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′— Tetraethylethylenediamine, 1,2-dipiperidinoethane, trimethylaminoethylpiperazine, N, N, N ′, N ″, N ″ -pentamethylethylenetriamine, N, N′-dioctyl-p-phenylenediamine and the like It is done.

Examples of ether compounds include linear ether compounds and cyclic ether compounds.
Examples of linear ether compounds include dimethyl ether, diethyl ether, diphenyl ether; ethylene glycol dialkyl ether compounds such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol dibutyl ether. And dialkyl ether compounds of diethylene glycol.
Cyclic ether compounds include tetrahydrofuran, dioxane, 2,5-dimethyloxolane, 2,2,5,5-tetramethyloxolane, 2,2-bis (2-oxolanyl) propane, furfuryl alcohol, Examples include alkyl ethers of furyl alcohol.

Examples of the alkali metal alkoxy compound include compounds represented by general formulas LiOR, KOR, and NaOR (wherein R is an alkyl group having 2 to 12 carbon atoms).
In particular, sodium alkoxide having an alkyl group having 3 to 6 carbon atoms is preferable, and sodium t-butoxide and sodium t-pentoxide are more preferable.

(Polymerization method)
The polymerization method of the block copolymer before hydrogenation of the hydrogenated block copolymer (A) may be batch polymerization, continuous polymerization, or a combination thereof. Any hydrogenated block copolymer (A) may be obtained.

(Polymerization temperature, polymerization time, polymerization atmosphere, polymerization pressure)
The polymerization temperature is generally 0 ° C to 180 ° C, preferably 30 ° C to 150 ° C.
The time required for the polymerization varies depending on the conditions, but is usually within 48 hours, particularly preferably 0.1 to 10 hours.
The polymerization atmosphere is preferably an inert gas atmosphere such as nitrogen gas.
The polymerization pressure is not particularly limited as long as the polymerization pressure is in a range sufficient to maintain the monomer and solvent in a liquid phase within the above polymerization temperature range.

(Coupling reaction)
In the polymerization of the block copolymer before hydrogenation of the hydrogenated block copolymer (A), a coupling reaction can be performed by adding a necessary amount of a bifunctional or higher functional coupling agent at the end of the polymerization.
Any known bifunctional coupling agent can be used, and is not particularly limited.
For example, dihalogen compounds such as dimethyldichlorosilane, dichlorodiphenylsilane, dimethyldibromosilane, and dibromoethane; acid esters such as methyl benzoate, ethyl benzoate, phenyl benzoate, phthalates, methyl acrylate, and ethyl acrylate An alkoxysilane compound such as dimethoxysilane or diethoxysilane;
Moreover, as a polyfunctional coupling agent more than trifunctional, any well-known thing can be used and it is not specifically limited.
For example, polyalcohols having three or more valences, polyepoxy compounds such as epoxidized soybean oil, diglycidyl bisphenol A, general formula R _(4-n) SiX _n (where each R is independent and has 1 to 20 hydrocarbon groups, X is halogen, n is an integer of 3 or 4, and silicon halide compounds such as methylsilyl trichloride, t-butylsilyltrichloride, silicon tetrachloride and bromine thereof And tin halide compounds such as polyvalent halogen compounds such as methyltin trichloride, t-butyltin trichloride and tin tetrachloride.
Further, an alkoxysilane compound represented by the general formula R _(4-n) Si (OR) _n (where each R is independently a hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 2 to 4). Examples thereof include trimethoxysilane, tetramethoxysilane, tetraethoxysilane and the like.
In addition, dimethyl carbonate or diethyl carbonate can also be used.

In the step of polymerizing the block copolymer before hydrogenation of the hydrogenated block copolymer (A) by living anion polymerization, a copolymer of two vinyl aromatic compounds and a conjugated diene compound described later Is preferably used.
The first copolymer (M1) has a vinyl aromatic compound content of 25 to 55 mass%. By using this (M1), excellent adhesiveness can be secured. If the content of the vinyl aromatic compound is less than 25% by mass, an effect of improving the tackiness can be obtained, but the adhesive strength is deteriorated, and when it is peeled off after long-term storage, an adhesive residue is generated. Moreover, when it exceeds 55 mass%, adhesiveness will not be obtained.
The content of the vinyl aromatic compound in the second copolymer (M2) is 55 to 80% by mass. By using this (M2), it is possible to prevent adhesive residue when peeling after being stored for a long time. However, when the content of the vinyl aromatic compound is less than 55% by mass, an adhesive residue is generated when peeling after long-term storage. When it exceeds 80 mass%, adhesiveness will deteriorate and it is not preferable.

The difference in vinyl aromatic compound content between the first copolymer (M1) and the second copolymer (M2) is preferably 5% by mass or more and 30% by mass or less.
Outside this range, there is a tendency for the performance balance between adhesiveness and adhesive residue resistance to deteriorate.

(Method for producing modified hydrogenated block copolymer)
As described above, as the hydrogenated block copolymer (A), a modified hydrogenated block copolymer having at least one functional group having a functional group bonded thereto can be used. There is no limitation in particular about the manufacturing method of a polymer, A conventionally well-known method is applicable.
The modified hydrogenated block copolymer is obtained by hydrogenating a modified block copolymer obtained by reacting with a modifier at the end of the polymerization of the copolymer of the vinyl aromatic compound and the conjugated diene compound.
For example, in living anionic polymerization, a method of performing hydrogenation after polymerization using a polymerization initiator having a functional group or an unsaturated monomer having a functional group may be used.
In addition, for example, as described in Japanese Patent Publication No. 4-39495 (US Pat. No. 5,115,035), a modifier is added to the living terminal of a polymer obtained using an organic alkali metal compound as a polymerization catalyst. Then, a method of hydrogenation may be used.
Alternatively, the block copolymer may be reacted with an organic alkali metal compound (metalation reaction), further reacted with a modifier, and then hydrogenated.
Alternatively, a method may be used in which after the hydrogenation of the copolymer, a metallation reaction is performed, and then a modifier is reacted.
Depending on the type of the modifier, the hydroxyl group, amino group, or the like may be an organometallic salt at the stage of reaction of the modifier. In that case, a hydroxyl group, an amino group, or the like can be formed by treatment with a compound having active hydrogen such as water or alcohol.

Examples of the method for producing the secondary modified hydrogenated block copolymer include a method in which the modified hydrogenated block copolymer is reacted with a secondary modifier.
Secondary modifiers include, for example, carboxylic acids having two or more carboxyl groups or acid anhydrides thereof, or secondary modifications having two or more acid anhydride groups, isocyanate groups, epoxy groups, silanol groups, and alkoxysilane groups. Agents.
Specifically, maleic anhydride, pyromellitic anhydride, 1,2,4,5-benzenetetracarboxylic dianhydride, toluylene diisocyanate, tetraglycidyl-1,3-bisaminomethylcyclohexane, bis- (3-triethoxysilylpropyl) -tetrasulfane and the like.
The secondary modified hydrogenated block copolymer is obtained by graft-modifying the hydrogenated block copolymer with an α, β-unsaturated carboxylic acid or a derivative thereof such as an anhydride, esterified product, amidated product or imidized product thereof. Can also be obtained.
Examples of the α, β-unsaturated carboxylic acid or derivative thereof include maleic anhydride, maleic anhydride imide, acrylic acid or ester thereof, methacrylic acid or ester thereof, and endo-cis-bicyclo [2,2,1]. -5-heptene-2,3-dicarboxylic acid or its anhydride.
The addition amount of the α, β-unsaturated carboxylic acid or derivative thereof is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the hydrogenated polymer.
The reaction temperature in the case of graft modification is preferably 100 to 300 ° C, more preferably 120 to 280 ° C.
For details of the graft modification method, reference can be made to, for example, JP-A No. 62-79211.

(Hydrogenation reaction)
The hydrogenation catalyst for obtaining the hydrogenated block copolymer (A) is not particularly limited, and a conventionally known catalyst can be used.
For example, (1) a supported heterogeneous hydrogenation catalyst in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth, or the like (2) Ni, Co, Fe, Cr, or the like So-called Ziegler type hydrogenation catalyst using transition metal salt such as organic acid salt or acetylacetone salt and reducing agent such as organic aluminum, (3) so-called organometallic complex such as organometallic compound such as Ti, Ru, Rh, Zr And homogeneous hydrogenation catalysts.
Specific examples of the hydrogenation catalyst include Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841, Japanese Patent Publication No. 1-337970, Japanese Patent Publication No. 1-53851, The hydrogenation catalyst described in Japanese Utility Model Publication No. 2-9041 can be used.
Preferred hydrogenation catalysts include mixtures with titanocene compounds and / or reducing organometallic compounds.
As the titanocene compound, compounds described in JP-A-8-109219 can be used. Specific examples include at least one ligand having a (substituted) cyclopentadienyl skeleton, indenyl skeleton or fluorenyl skeleton such as biscyclopentadienyl titanium dichloride and monopentamethylcyclopentadienyl titanium trichloride. Compounds.
Examples of the reducing organometallic compound include organic alkali metal compounds such as organolithium, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds.

The hydrogenation reaction is preferably performed in a temperature range of 0 to 200 ° C., more preferably 30 to 150 ° C.
The pressure of hydrogen used for the hydrogenation reaction is preferably 0.1 to 15 MPa, more preferably 0.2 to 10 MPa, and still more preferably 0.3 to 5 MPa.
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.

In the solution obtained after the hydrogenation reaction, the catalyst residue can be removed if necessary, and the hydrogenated block copolymer (A) can be separated from the solvent.
As a separation method, for example, a polar solvent that is a poor solvent for a hydrogenated block copolymer such as acetone or alcohol is added to the solution obtained after the hydrogenation reaction to precipitate the hydrogenated block copolymer (A). The solution obtained after the hydrogenation reaction is poured into hot water, the solvent is removed by steam stripping, and the solution obtained after the hydrogenation reaction is heated directly to distill the solvent. The method of leaving is mentioned.
In addition, you may add stabilizers, such as various phenol type stabilizers, phosphorus type stabilizers, sulfur type stabilizers, and amine type stabilizers, to the hydrogenated block copolymer (A).

[Method for producing composition for pressure-sensitive adhesive]
The composition for adhesives of this embodiment can be manufactured by a conventionally well-known method.
For example, a melt kneading method using a general mixer such as a Banbury mixer, a single screw extruder, a twin screw extruder, a kneader, a multi-screw extruder, etc. A method of removing the solvent by heating after coating on the Kizai film is used.

The adhesive composition of the present embodiment may be foamed from the viewpoint of weight reduction, softening, and good adhesion to an uneven surface. Examples of the foaming method include a chemical method, a physical method, and use of a thermal and thermal expansion type microballoon. In each case, bubbles can be distributed inside the material by adding a chemical foaming agent such as an inorganic foaming agent or an organic foaming agent, a physical foaming agent or the like, or adding a thermal and thermal expansion type microballoon.
Moreover, you may aim at weight reduction, softening, and the improvement of adhesiveness by adding a hollow filler (already inflated balloon).

[Other composition of adhesive composition]
The adhesive composition of the present embodiment can further contain one or more thermoplastic resins.
Thereby, improvement, such as adhesiveness and adhesive strength, is achieved.
Examples of thermoplastic resins include polyethylene, polypropylene, butadiene resin, acrylonitrile / styrene resin, acrylonitrile / butadiene / styrene resin, polymethacrylstyrene, methacrylic resin, styrene, olefin, polyester, polyurethane, etc. And may contain petroleum resins as various tackifiers.
In particular, hydrogenated styrene-based elastomers and tackifying resins are suitable.

((B) Hydrogenated styrene elastomer)
In the adhesive composition of this embodiment, (B) hydrogenated styrene-type elastomer may further be contained.
(B) Although it does not specifically limit as hydrogenated styrene-type elastomer, For example, styrene-ethylene-butylene-styrene (SEBS) which saturated styrene-butadiene-styrene (SBS), styrene-isoprene-styrene by hydrogenation, Styrene-ethylene-propylene-styrene (SEPS) is a typical hydrogenated styrene-based elastomer, but may be an elastomer having a structure such as styrene-ethylene-butylene (SEB) or styrene-ethylene-propylene (SEP).
In addition, the hydrogenated styrene-based elastomer has a hydroxyl group, a carboxyl group, a carbonyl group, a thiocarbonyl group, an acid halide group, an acid anhydride group, a thiocarboxylic acid group, an aldehyde group, a thioaldehyde group, a carboxylic acid ester group, an amide group, Sulfonic acid group, sulfonic acid ester group, phosphoric acid group, phosphoric acid ester group, amino group, imino group, nitrile group, pyridyl group, quinoline group, epoxy group, thioepoxy group, sulfide group, isocyanate group, isothiocyanate group, halogen A reactive elastomer having a functional group, which includes a silicon halide group, an alkoxysilicon group, a tin halide group, a boronic acid group, a boron-containing group, a boronate group, an alkoxytin group, and a phenyltin group, may be used.

  (B) The composition ratio of the hydrogenated block copolymer (A) and the hydrogenated styrene elastomer (B) in the case of further containing a hydrogenated styrene elastomer is not particularly limited, but hydrogen The added block copolymer (A) is preferably 10% by mass to 80% by mass, the hydrogenated styrene elastomer (B) is preferably 20% by mass to 90% by mass, and the component (A) is 20% by mass to 70% by mass. %, Component (B) is more preferably 30% by mass to 80% by mass, component (A) is 30% by mass to 60% by mass, and component (B) is 40% by mass to 70% by mass. Further preferred.

  Further, after the hydrogenated styrenic elastomer (B) to be used has a vinyl bond content of the conjugated diene part before hydrogenation of 50 mol% or more, after the adhesive composition in this embodiment has been adhered for a long time. This is preferable because the adhesive strength does not change greatly.

  When the blending ratio of the hydrogenated block copolymer (A) is less than 10% by mass, the adhesiveness is inferior, the adhesive strength after adhesion for a long time changes, and the adhesive strength at low temperature is reduced. Therefore, it is not preferable. Moreover, since the adhesive strength will fall when the mixture ratio of a hydrogenated block copolymer (A) exceeds 80 mass%, it is unpreferable.

((C) tackifier resin)
The adhesive composition in the present embodiment may further contain (C) a tackifier resin.
As the tackifier resin, there is no particular limitation, for example, rosin terpene resin, hydrogenated rosin terpene resin, coumarone resin, phenol resin, terpene-phenol resin, aromatic hydrocarbon resin, Known tackifying resins such as aliphatic hydrocarbon resins can be used. A tackifier may be used independently and may be used in mixture of 2 or more types.
As specific examples of the tackifier, those described in “Rubber / Plastic Compounding Chemicals” (edited by Rubber Digest Co., Ltd.) can be used.
(C) The adhesion strength is improved by using a tackifier resin.
The content of the (C) tackifier resin in the adhesive composition of the present embodiment is 0 to 200 parts by mass, preferably 0 when the hydrogenated block copolymer (A) is 100 parts by mass. Used in the range of ˜100 parts by mass. From the viewpoint of improving productivity and adhesiveness, 5 to 80 parts by mass is particularly preferable. If necessary, a styrene elastomer such as SBS may be further added. (C) When the usage-amount of tackifier resin exceeds 200 mass parts, since the adhesive force after a long-term sticking is strong and it is easy to produce adhesive residue in the case of peeling, it is not preferable.

((D) softener)
The adhesive composition of this embodiment may further contain (D) a softening agent.
(D) As the softener, either a mineral oil softener or a synthetic resin softener can be used.
Mineral oil softeners generally include mixtures of aromatic hydrocarbons, naphthenic hydrocarbons, and paraffinic hydrocarbons. Paraffinic hydrocarbons account for 50% or more of all carbon atoms. Is called paraffinic oil, naphthenic hydrocarbons with 30-45% carbon atoms are called naphthenic oils, and aromatic hydrocarbons with 35% or more carbon atoms are aromatic. It is called oil.
As the softening agent (D), paraffinic oil which is a softening agent for rubber is preferable, and as the synthetic resin softening agent, for example, polybutene, low molecular weight polybutadiene and the like are preferable.

(D) By containing a softening agent, in the adhesive composition of this embodiment, adhesiveness and adhesiveness are improved.
The content of the (D) softener in the adhesive composition of the present embodiment ensures the mechanical strength sufficient for practical use in the (D) softener bleed suppression and the pressure-sensitive adhesive composition of the present embodiment. It is preferable that it is 0-100 mass% from a viewpoint to do.
(D) As for content in the composition for adhesives of a softener, the range of 0-50 mass% is more preferable, and the range of 0-30 mass% or less is further more preferable.
As the softening agent (D), paraffinic oil which is a softening agent for rubber is preferable, and as the synthetic resin softening agent, for example, polybutene, low molecular weight polybutadiene and the like are preferable.

(Antioxidants, light stabilizers, etc.)
You may add stabilizers, such as antioxidant and a light stabilizer, to the composition for adhesives of this embodiment.
Examples of the antioxidant include 2,6-di-t-butyl-4-methylphenol, n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-t-butylphenyl) propionate, 2 , 2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 2,4-bis [(octylthio) methyl] -o-cresol 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2,4-di-t-amyl-6- [1- (3 , 5-di-t-amyl-2-hydroxyphenyl) ethyl] phenyl acrylate, 2- [1- (2-hydroxy-3,5-di-tert-pentylphenyl)] acrylate, and the like. Antioxidants such as dilauryl thiodipropionate, lauryl stearyl thiodipropionate pentaerythritol-tetrakis (β-lauryl thiopropionate); tris (nonylphenyl) phosphite, tris ( And phosphorus-based antioxidants such as 2,4-di-t-butylphenyl) phosphite.
Examples of the light stabilizer include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-t-butylphenyl) benzotriazole, 2- (2 Benzotriazole ultraviolet absorbers such as '-hydroxy-3', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, benzophenone ultraviolet absorbers such as 2-hydroxy-4-methoxybenzophenone, or hindered amines System light stabilizers and the like.

  In addition, the adhesive composition of the present embodiment includes, if necessary, pigments such as Bengala and titanium dioxide; waxes such as paraffin wax, microcrystalline wax, and low molecular weight polyethylene wax; amorphous polyolefin, ethylene Polyolefin or low molecular weight vinyl aromatic thermoplastic resins such as ethyl acrylate copolymer; natural rubber; polyisoprene rubber, polybutadiene rubber, styrene-butadiene rubber, ethylene-propylene rubber, chloroprene rubber, acrylic rubber, isoprene-isobutylene Rubber, polypentenamer rubber or the like may be added. Other examples include those described in “Rubber / Plastic Compounding Chemicals” (edited by Rubber Digest Co., Ltd.).

The adhesive composition of the present embodiment preferably has a melt flow rate (190 ° C., 2.16 kg) of 1 or more from the viewpoint of ensuring good extrudability and obtaining excellent adhesion. It is preferably 40 or less from the viewpoint of reducing the adhesive residue when peeled off after standing for a long time after bonding, and obtaining practically sufficient adhesive strength.
As a range of a melt flow rate (190 degreeC, 2.16 kg), 2-30 are more preferable, and 5-20 are more preferable.
The solution viscosity (15% toluene solution) is preferably from 5 to 200 mPa · s, more preferably from 10 to 100 mPa · m, in terms of moldability, adhesion, adhesive residue resistance, and adhesive strength.

[Surface protection film]
The surface protective film of this embodiment has a configuration comprising a pressure-sensitive adhesive layer obtained by laminating the above-mentioned adhesive composition of this embodiment on a predetermined substrate film.
As the base film, either a nonpolar resin or a polar resin can be used, but from the viewpoint of performance and price, the nonpolar resin is polyethylene, homo or block polypropylene, and the polar resin is polyethylene terephthalate, polybutylene. Preferred examples include polyester resins such as terephthalate, polyamide resins, ethylene-vinyl acetate copolymers and hydrolysates thereof.
About the thickness of each layer in the surface protection film of this embodiment, the layer of an adhesive composition becomes like this. Preferably it is 100 micrometers or less, More preferably, it is 5-80 micrometers.
The substrate film is preferably 5 mm or less, preferably 3 mm or less, more preferably 1 mm or less. In particular, 300 micrometers or less are preferable and 10-200 micrometers is more preferable.
In general, a sheet having a thickness exceeding 300 μm is referred to as a sheet, but in the present specification, these are also referred to as a film.

As a manufacturing method of the surface protection film in this embodiment, the method by a film extruder and the method of coating are mentioned, for example.
First, as a method using a film extruder, a component of an adhesive composition layer and a thermoplastic resin component of a base film layer are made into two flows in a melt co-extruder, that is, an adhesive layer. The fluid for forming and the fluid for forming the substrate body film are merged in the die mouth to form a single fluid and extruded, and the adhesive layer and the resin film layer are combined to produce the fluid.
As a method for coating, it can be produced by dissolving the pressure-sensitive adhesive layer composition in a predetermined solvent, preparing a coating solution, and applying this to a base film.
In the case of the method using a film extruder, the adhesive composition is excellent in productivity because it can be produced by dry blending each component in advance.
Moreover, as a coating method, it can manufacture by melt | dissolving the composition for adhesives in the solvent which can be melt | dissolved, apply | coating on a base film using a coater etc., and heat-drying a solvent. Suitable solvents for the pressure-sensitive adhesive composition include cyclohexane, toluene, xylene, diethyl ether, tetrahydrofuran, chloroform and the like.

Examples of the present invention and comparative examples will be specifically described below.
First, evaluation methods and physical property measurement methods applied to Examples and Comparative Examples are shown below.

(Characteristic evaluation of polymer)
A method for measuring the structure and physical properties of the polymer described later is shown.
(1) Styrene content, vinyl bond amount of conjugated diene, hydrogenation rate of double bond based on conjugated diene Styrene content in polymer, vinyl bond amount of conjugated diene, hydrogenation rate of double bond based on conjugated diene Was measured by nuclear magnetic resonance spectrum analysis (NMR) under the following conditions.
Measuring instrument: JNM-LA400 (manufactured by JEOL)
Solvent: Deuterated chloroform Sample: Sample taken before and after hydrogenation of polymer Sample concentration: 50 mg / ml
Observation frequency: 400 MHz
Chemical shift criteria: TMS (tetramethylsilane)
Pulse delay: 2.904 seconds Number of scans: 64 times Pulse width: 45 °
Measurement temperature: 26 ° C

(2) Styrene block content
I. M. Kolthoff, etal. , J .; Polym. Sci. 1946, Vol. 1, p. It was measured by the osmium tetroxide method described in 429.
Measurement sample: sample taken before hydrogenating the polymer Solution for polymer decomposition: solution in which 0.1 g of osmic acid was dissolved in 125 ml of tertiary butanol

(3) Weight average molecular weight and molecular weight distribution The weight average molecular weight and molecular weight distribution of the hydrogenated block copolymer (A) were measured by gel permeation chromatography (GPC) under the following conditions.
Measuring device: LC-10 (manufactured by Shimadzu Corporation)
Column: TSKgelGMHXL (4.6 mm ID × 30 cm), two solvents: tetrahydrofuran calibration curve sample: commercially available standard polystyrene (manufactured by Tosoh Corporation), 10-point measurement The molecular weight distribution is the weight average molecular weight and number average molecular weight obtained. I asked for the ratio.

(4) Coupling rate The coupling rate of the hydrogenated block copolymer (A) was determined by using the molecular weight distribution measured by GPC and using the peak area before coupling and the peak area after coupling.

(5) Melt flow rate The melt flow rate of the hydrogenated block copolymer (A) was determined by the following method.
In accordance with JIS K-7210, the amount of resin that flowed out for 10 minutes was measured.
Measurement temperature: 190 ° C
Load weight: 2.16 kg

[Characteristic evaluation of adhesive composition]
(1) Solution viscosity The adhesive composition was dissolved in toluene so as to be 15% by mass, and the solution viscosity was measured with a Brookfield viscometer.
The measurement temperature was 23 ° C.

(2) Adhesion A surface protective film prepared in the following Examples, Reference Examples, and Comparative Examples was attached to a PMMA plate (arithmetic surface roughness: 1.1 μm), and in a relative humidity of 23 ° C. × 50%. A rubber roll having a weight of 1 kg (diameter: 10 cm) was rolled and pasted, and then the area ratio between the close contact portion and the gap portion was visually observed.
In Tables 3 to 5 below, the evaluation of adhesion was performed in four stages of ◎, ○, ×, and XX.
I will show you these evaluation criteria.
A: No bubble that can be visually observed with respect to the peeled area (1 m ² ).
A: One bubble can be visually observed with respect to the peeled area (1 m ² ).
×: ² to 4 bubbles that can be visually observed with respect to the peeled area (1 m ² ).
XX: 5 or more bubbles that can be visually observed with respect to the peeled area (1 m ² ).

(3) Adhesive strength (g / 25mm)
A surface protective film prepared in Examples 1 to 10 and Comparative Examples 1 to below is attached to a PMMA plate (surface arithmetic average roughness: 0.1 μm), and a 180 ° peeling test is attached at a temperature of 23 ° C. I went right after attaching.
The “180 degree peel test” was performed according to the standard of JIS K6854-2, Adhesive-Peeling adhesive strength test method—Part 2: 180 degree peeling.

(4) Adhesive residue evaluation when peeled after long-term storage from adhesion The surface protective film produced in the following Examples, Reference Examples, and Comparative Examples was attached to a PMMA plate (arithmetic surface roughness: 1.1 μm). The rubber roll (diameter 10 cm) having a weight of 1 kg was rolled and pasted at 23 ° C. × 50% relative humidity, and then allowed to stand at a temperature condition of 23 ° C. for 14 days. Thereafter, the surface protective film was peeled off, and the state of the adhesive residue on the PMMA plate was evaluated.
In Tables 3 to 5 below, the evaluation of the adhesive residue was performed in four stages of 、, ○, ×, and XX.
I will show you these evaluation criteria.
A: No adhesive residue that can be visually observed with respect to the peeled area (1 m ² ).
A: One adhesive residue that can be visually observed with respect to the peeled area (1 m ² ).
X: The adhesive residue which can be visually observed with respect to a peeling area (1m < ² >) is a thing of 2-4 points | pieces.
Xx: The adhesive residue which can be visually observed with respect to a peeling area (1 m < ² >) is 5 or more points | pieces.

[Adjustment of hydrogenated block copolymer, thermoplastic resin containing hydrogenated block copolymer, crosslinked body, crosslinked foam]
(I) Hydrogenated block copolymer (1) Preparation of hydrogenation catalyst The hydrogenation catalyst used for the hydrogenation reaction was prepared by the following method.
(A) Hydrogenation catalyst I
(I) A reaction vessel purged with nitrogen was charged with 1 liter of dried and purified cyclohexane.
(Ii) 100 mmol of bis (η ⁵ -cyclopentadienyl) titanium dichloride was added to the reactor.
(Iii) An n-hexane solution containing 200 mmol of trimethylaluminum was added with sufficient stirring.
(Iv) The reaction was allowed to proceed for about 3 days under room temperature (23 ° C.) conditions.
(B) Hydrogenation catalyst II
(I) A reaction vessel purged with nitrogen was charged with 2 liters of dried and purified cyclohexane.
(Ii) The reactor is charged with 40 mmol of bis (η ⁵ -cyclopentadienyl) titanium di- (p-tolyl) and 1,2-polybutadiene (1,2-vinyl) having a molecular weight of about 1,000. 150 g) was dissolved.
(Iii) Further, a cyclohexane solution containing 60 mmol of n-butyllithium was added to the reactor and reacted at room temperature for 5 minutes.
(Iv) Thereafter, 40 mmol of n-butanol was immediately added, stirred, and stored at room temperature.
(C) Hydrogenation catalyst III
The catalyst described in Japanese Patent No. 3273635 was used.

(2) Production of Hydrogenated Block Copolymer Table 1 below shows the raw materials used for the production of hydrogenated block copolymers <Polymer 1> to <Polymer 7> described below and the blending amounts thereof.
The raw materials shown in Table 1 below will be described below.
Cyclohexane: Used as the initial charge solvent.
n-BuLi: normal butyl lithium TMEDA: N, N, N ′, N′-tetramethylethylenediamine. Used diluted with cyclohexane.
St: Styrene Bd: Butadiene Ip: Isoprene

  The monomer (St, Bd) was prepared by diluting with cyclohexane to prepare a 24% monomer solution, whether used alone or as a monomer mixture.

Benzoic acid Et: ethyl benzoate. Used as a bifunctional coupling agent. Used diluted with cyclohexane.
Methanol: used as a polymerization terminator.
Octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate: used as a stabilizer.

<Polymer 1>
A stirrer and a jacketed tank reactor (internal volume: 10 liters) were used as the reactor.
The structure of the reactor and the reaction at each stage will be described.
(First stage): Cyclohexane was charged into the reactor and the temperature was adjusted to 70 ° C., and then n-butyllithium was added from the bottom of the reactor.
Next, N, N, N ′, N′-tetramethylethylenediamine was added.
Thereafter, styrene was fed over about 10 minutes.
After stopping the supply of styrene, the reaction was carried out while maintaining the temperature in the reactor at 70 ° C. for 15 minutes.

(Second stage): Butadiene and styrene were continuously supplied to the reactor at a constant rate over 60 minutes, and the temperature in the reactor during that period was adjusted to 70 to 80 ° C.
After stopping the supply of butadiene and styrene, the reaction was carried out for 10 minutes while adjusting the temperature in the reactor to 70 ° C.

(Coupling reaction)
Ethyl benzoate was added to the reactor, and the reaction was carried out for 10 minutes while adjusting the temperature in the reactor to 70 ° C. Thereafter, methanol was added as a polymerization terminator.

(Hydrogenation reaction)
Hydrogenation catalyst I was added to the reactor, and a hydrogenation reaction was carried out for 1 hour at a hydrogen pressure of 0.7 MPa and a temperature of 65 ° C.
After the hydrogenation reaction, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate was added to obtain a hydrogenated copolymer (Polymer 1).

The production conditions of <Polymer 1> are shown in Table 1 below.
In addition, <polymer 1> has a styrene content, a styrene block content, a vinyl content in a conjugated diene, a coupling rate, a weight average molecular weight, a molecular weight distribution, a hydrogenation rate to a double bond in the conjugated diene, and a melt flow. The rates are shown in Table 2 below.
In addition, the styrene content of <Polymer 1>, the styrene block content, the vinyl content in the conjugated diene, the coupling rate, the weight average molecular weight, the molecular weight distribution, and the hydrogenation rate to the double bond in the conjugated diene is 2 Measurement was performed using a sample extracted at the end of the stage.
However, the vinyl content in the conjugated diene was measured before the hydrogenation reaction.
The hydrogenation rate to the double bond in the conjugated diene was measured after completion of the hydrogenation reaction.
The weight average molecular weight and molecular weight distribution were also measured after the hydrogenation reaction.
The coupling rate calculated using the samples at the end of the second stage and at the end of the coupling reaction was 50%.

<Polymers 2, 3, 4, 5>
As shown in Table 1 below, the amount of N, N, N ′, N′-tetramethylethylenediamine, the amount of monomer, and the type of hydrogenation catalyst were appropriately changed, and polymerization was carried out in the same manner as <Polymer 1> described above. It was.

<Polymer 6>
Reactor: The same as <Polymer 1> described above was used.
(First stage): Cyclohexane was charged into the reactor, adjusted to a temperature of 60 ° C., and then n-butyllithium was added from the bottom of the reactor.
Next, N, N, N ′, N′-tetramethylethylenediamine was added.
Thereafter, styrene was fed over about 10 minutes. After stopping the supply of styrene, the temperature in the reactor was maintained at 60 ° C. for 15 minutes for reaction.
(Second stage): Butadiene was continuously fed to the reactor at a constant rate over 60 minutes, and then reacted for 10 minutes.
The temperature in the reactor was adjusted to 60 to 70 ° C.
(3rd stage): Styrene was fed over about 10 minutes.
(Hydrogenation reaction): Hydrogenation catalyst I was added to the reactor, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 65 ° C. Methanol was added after the reaction. Next, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate was added to obtain a hydrogenated block copolymer <Polymer 6>.

The production conditions of <Polymer 6> are shown in Table 1 below.
In addition, the styrene content of <polymer 6>, the styrene block content, the vinyl content in the conjugated diene, the weight average molecular weight, the molecular weight distribution, the hydrogenation rate to the double bond in the conjugated diene, and the melt flow rate are as follows: It shows in Table 2.
The <polymer 6> has a styrene content, a styrene block content, a vinyl content in the conjugated diene, a weight average molecular weight, a molecular weight distribution, and a hydrogenation rate to the double bond in the conjugated diene at the end of the third stage. It measured using the sample extracted.
However, the vinyl content in the conjugated diene was measured before the hydrogenation reaction.
The hydrogenation rate to the double bond in the conjugated diene was measured after completion of the hydrogenation reaction.
The weight average molecular weight and molecular weight distribution were also measured after the hydrogenation reaction.

<Polymer 7>
Reactor: The same as <Polymer 1> described above was used.
(First stage): Cyclohexane was charged into the reactor, adjusted to a temperature of 70 ° C., and then n-butyllithium was added from the bottom of the reactor.
Next, N, N, N ′, N′-tetramethylethylenediamine was added.
Thereafter, styrene was fed over about 5 minutes.
After stopping the supply of styrene, the temperature in the reactor was maintained at 70 ° C. for 15 minutes for reaction.
(Second stage): Styrene and butadiene were continuously fed to the reactor at a constant rate over 20 minutes, and then reacted for 5 minutes.
The temperature inside the reactor was adjusted to 70 to 80 ° C.
(3rd stage): Styrene and butadiene were continuously supplied to the reactor at a constant rate over 40 minutes, and then reacted for 10 minutes.
The temperature inside the reactor was adjusted to 70 to 80 ° C.
(4th stage): Styrene was continuously supplied to the reactor at a constant rate over 5 minutes, and then reacted for 15 minutes.
The temperature inside the reactor was adjusted to 70 ° C. Thereafter, methanol was added.
(Hydrogenation reaction) The obtained copolymer was subjected to a hydrogenation reaction in the same manner as in <Polymer 1> described above.
After the reaction was completed, a stabilizer was added to obtain a hydrogenated block copolymer <Polymer 7>.

The production conditions of <Polymer 7> are shown in Table 1 below.
In addition, the styrene content of <polymer 7>, the styrene block content, the vinyl content in the conjugated diene, the weight average molecular weight, the molecular weight distribution, the hydrogenation rate to the double bond in the conjugated diene, and the melt flow rate are as follows: It shows in Table 2.
The <polymer 7> has a styrene content, a styrene block content, a vinyl content in the conjugated diene, a weight average molecular weight, a molecular weight distribution, and a hydrogenation rate to the double bond in the conjugated diene at the end of the fourth stage. It measured using the sample extracted.
However, the weight average molecular weight, molecular weight distribution, and hydrogenation rate to the double bond in the conjugated diene were measured after completion of the hydrogenation reaction.

[Example 1]
A 15% toluene solution of (Polymer 1) was prepared as the hydrogenated block copolymer (A).
Next, the above-mentioned toluene solution was applied to a 25 μm thick polyester film using an applicator, air-dried in a draft for 30 minutes, and then toluene was completely evaporated in an oven at 70 ° C. to prepare a surface protective film.
In addition, the thickness of the adhesive composition layer was 15 μm.
The evaluation results for this surface protective film are shown in Table 3 below.

[Example 2]
Instead of (Polymer 1), (Polymer 7) was used as the hydrogenated block copolymer (A).
Other conditions were the same as in Example 1, a surface protective film was prepared, and the characteristics were evaluated.
The evaluation results are shown in Table 3 below.

[Comparative Example 1]
Instead of (Polymer 1), (Polymer 5) was used.
Other conditions were the same as in Example 1, and a surface protective film was produced and evaluated for characteristics.
The evaluation results are shown in Table 3 below.

[Comparative Example 2]
Instead of (Polymer 1), (Polymer 6) was used.
Other conditions were the same as in Example 1, and a surface protective film was produced and evaluated for characteristics.
The evaluation results are shown in Table 3 below.

Example 3
50% by mass of (Polymer 1) as hydrogenated block copolymer (A), hydrogenated styrene elastomer (B) (polymer structure is EB-S-EB-S, styrene content is 13%, butadiene before hydrogenation A 15% toluene solution was prepared by using 50% by mass of a vinyl content of 73% and MFR (230 ° C., 2.16 kg load) of 3.5 g / 10 min).
Using this toluene solution, a surface protective film was produced in the same manner as in Example 1, and the characteristics were evaluated.
The evaluation results are shown in Table 4 below.

Example 4
As the hydrogenated block copolymer (A), (Polymer 2) was used instead of (Polymer 1).
Further, the ratio of (Polymer 2) and hydrogenated styrene elastomer (B) was changed as shown in Table 4 below.
Other conditions were the same as in Example 3, and a 15% toluene solution was prepared.
Using this toluene solution, a surface protective film was produced in the same manner as in Example 1, and the characteristics were evaluated.
The evaluation results are shown in Table 4 below.

Example 5
Instead of (Polymer 1), (Polymer 4) was used as the hydrogenated block copolymer (A).
Further, the ratio of (Polymer 4) and hydrogenated styrene elastomer (B) was changed as shown in Table 4 below.
Other conditions were the same as in Example 3, and a 15% toluene solution was prepared.
Using this toluene solution, a surface protective film was produced in the same manner as in Example 1, and the characteristics were evaluated.
The evaluation results are shown in Table 4 below.

Example 6
Instead of (Polymer 1), (Polymer 7) was used as the hydrogenated block copolymer (A).
The ratio of (Polymer 7) to hydrogenated styrene-based elastomer (B) was as shown in Table 4 below.
Other conditions were the same as in Example 3, and a 15% toluene solution was prepared.
Using this toluene solution, a surface protective film was produced in the same manner as in Example 1, and the characteristics were evaluated.
The evaluation results are shown in Table 4 below.

[Comparative Example 3]
Instead of (Polymer 1), (Polymer 3) was used.
Other conditions were the same as in Example 3, and a 15% toluene solution was prepared.
Using this toluene solution, a surface protective film was produced in the same manner as in Example 1, and the characteristics were evaluated.
The evaluation results are shown in Table 4 below.

[Comparative Example 4]
(Polymer 5) was used instead of (Polymer 1).
Other conditions were the same as in Example 3, and a 15% toluene solution was prepared.
Using this toluene solution, a surface protective film was produced in the same manner as in Example 1, and the characteristics were evaluated.
The evaluation results are shown in Table 4 below.

[Comparative Example 5]
Instead of (polymer 1), (polymer 6) was used.
Other conditions were the same as in Example 3, and a 15% toluene solution was prepared.
Using this toluene solution, a surface protective film was produced in the same manner as in Example 1, and the characteristics were evaluated.
The evaluation results are shown in Table 4 below.

[Example 7], [Example 8], [Reference Example 1], [Reference Example 2]
The ratio of (Polymer 1) and hydrogenated styrene elastomer was changed as shown in Table 5 below. Other conditions were the same as in Example 3, and a 15% toluene solution was prepared.
Using this toluene solution, a surface protective film was produced in the same manner as in Example 1, and the characteristics were evaluated.
The evaluation results are shown in Table 5 below.

Example 9
(Polymer 1) (A), hydrogenated styrene elastomer (B), tackifier resin (C) (hydrogenated petroleum resin, Alcon P115, manufactured by Arakawa Chemical Co., Ltd.) and softener (Diana Process Oil PW90, Idemitsu Kosan Co., Ltd.) was made into the composition shown in Table 5 below, and the other conditions were the same as in Example 3 to prepare a 15% toluene solution.
Using this 15% toluene solution, a surface protective film was produced in the same manner as in Example 1, and the characteristics were evaluated.
The evaluation results are shown in Table 5 below.

[Example 10], [Comparative Example 6]
(Polymer 1), tackifier resin (C) (hydrogenated petroleum resin, Alcon P115, manufactured by Arakawa Chemical Industries, Ltd.) have the composition shown in Table 5 below, and other conditions are the same as in Example 3. As a result, a 15% toluene solution was prepared.
Using this 15% toluene solution, a surface protective film was produced in the same manner as in Example 1, and the characteristics were evaluated.
The evaluation results are shown in Table 5 below.

As shown in Table 3, in Examples 1 and 2, both have good adhesion, practically sufficient adhesion strength has been obtained, and when peeled after standing for a long time after bonding together There was no adhesive residue and good peelability was achieved.
On the other hand, in Comparative Example 1 and Comparative Example 2, since the hydrogenation rate of the polymers 5 and 6 to the double bond in the conjugated diene was too high, good adhesion could not be obtained. Moreover, in Comparative Example 2, the solution viscosity was high and the coating could not be performed uniformly, and a stable measurement value could not be obtained for the adhesive strength.

As shown in Table 4, in Examples 3 to 6, the adhesiveness was good, practically sufficient adhesive strength was obtained, and when left after standing for a long time, the adhesive residue remained. And good peelability was realized.
On the other hand, in Comparative Examples 3-5, since the hydrogenation rate of the double bond in the conjugated diene of the polymers 3, 5, and 6 was too high, adhesiveness deteriorated.

As shown in Table 5, in each of Examples 7 to 10, good adhesion and practically sufficient adhesive strength were obtained. And good peelability was realized.
Further, as shown in Table 5, in Reference Examples 1 and 2, since the ratio of the copolymer (A) to the hydrogenated styrene elastomer (B) is poor, the copolymer (A) is rich in the reference example. In Example 2, which is rich in component (B), the adhesion is enhanced when adhered for a long time, and the adhesive adheres too much to the adherend. As a result, the adhesive residue increases when the film is peeled off. It was.
Moreover, as shown in Table 5, in Comparative Example 6, polymer 5 was too high in the hydrogenation rate of the double bond in the conjugated diene, so that good evaluation was not obtained for the peelability.

  The adhesive composition of the present invention has industrial applicability as an adhesive that is applied to a film for surface protection such as metal, glass, and synthetic resin.

Claims (17)

Mainly composed of vinyl aromatic units and conjugated diene units,
(A) The content of the vinyl aromatic unit exceeds 60% by mass and is 90 % by mass or less,
(B) The content of the vinyl aromatic polymer block is 30% by mass or less,
(C) the hydrogenation rate to the double bond based on conjugated diene is less than 70%,
(D) The weight average molecular weight is 5 × 10 ^{4 to} 100 × 10 ^4.
An adhesive composition comprising the hydrogenated block copolymer (A). Mainly composed of vinyl aromatic units and conjugated diene units,
(A) The content of vinyl aromatic units exceeds 60% by mass and is 90% by mass or less,
(B) The content of the vinyl aromatic polymer block is 30% by mass or less,
(C) the hydrogenation rate to the double bond based on conjugated diene is less than 70%,
(D) The weight average molecular weight is 5 × 10 ^Four ~ 100 × 10 ^Four
10% to 80% by mass of the hydrogenated block copolymer (A),
(B) 20% to 90% by mass of hydrogenated styrene elastomer,
An adhesive composition containing
Mainly composed of vinyl aromatic units and conjugated diene units,
(A) The content of vinyl aromatic units exceeds 60% by mass and is 90% by mass or less,
(B) The content of the vinyl aromatic polymer block is 30% by mass or less,
(C) the hydrogenation rate to the double bond based on conjugated diene is less than 70%,
(D) The weight average molecular weight is 5 × 10 ^Four ~ 100 × 10 ^Four
A hydrogenated block copolymer (A),
  (C) a tackifier,
An adhesive composition containing The vinyl bond amount of the conjugated diene portion before hydrogenation of the (B) hydrogenated styrene elastomer is 5
The adhesive composition according to claim 2 , which is 0 mol% or more. The pressure-sensitive adhesive composition according to any one of claims 2 to 4, further comprising one or more thermoplastic resins. (C) The adhesive composition according to claim 2 or 4 , further comprising a tackifier resin. The adhesive composition according to claim 2, further comprising at least one thermoplastic resin and (C) a tackifier resin. The hydrogenated block copolymer (A), according to any one of claims 1 to 7 having at least one hydrogenated copolymer block (S) composed mainly of vinyl aromatic units and conjugated diene units Adhesive composition. The pressure-sensitive adhesive composition according to any one of claims 1 to 8, wherein a hydrogenation rate of the hydrogenated block copolymer (A) to a double bond based on a conjugated diene is 65% or less. The hydrogenated copolymer block (S) has two or more segments having different vinyl aromatic compound contents,
The adhesive composition according to claim 8 or 9 , wherein a difference in vinyl aromatic compound content in any two segments is 5% by mass or more. The hydrogenated block copolymer (A), the difference in the vinyl aromatic compound content is not less 5% by mass or more, according to any one of claims 1 to 10 containing two segments adjacent to each other Adhesive composition. Segments with different vinyl aromatic compound content are:
A segment (S1) having a monomer composition having a vinyl aromatic compound content of 25 to 55% by mass and a segment having a monomer composition having a vinyl aromatic compound content of 55 to 80% by mass (S2)
Including
The pressure-sensitive adhesive composition according to claim 10 or 11 , wherein (S1) and (S2) are each 30% by mass or more based on the copolymer block (S). A method for producing an adhesive composition according to any one of claims 1 to 12 ,
A step of polymerizing the block copolymer before hydrogenation of the hydrogenated block copolymer (A) by living anion polymerization,
In the polymerization step of the block copolymer before hydrogenation of the hydrogenated block copolymer (A), the ratio of the vinyl aromatic compound and the conjugated diene is inclined, or the vinyl aromatic compound and the conjugated diene are Including a step of polymerizing the copolymers having different ratios in two or more stages,
A method for producing an adhesive composition. In the step of polymerizing the block copolymer before hydrogenation of the hydrogenated block copolymer (A) by living anion polymerization,
A vinyl aromatic compound and a conjugated diene,
As a first copolymer (M1) having a vinyl aromatic compound content of 25 to 55% by mass, a step of polymerizing in addition to the polymerization tank;
Unlike the composition of the first copolymer (M1), the vinyl aromatic compound content is 55-80.
The manufacturing method of the adhesive composition of Claim 13 superposed | polymerized by the process superposed | polymerized in addition to a polymerization tank as a 2nd copolymer (M2) which is the mass%. The viscosity according to claim 14 , wherein a difference in vinyl aromatic compound content between the first copolymer (M1) and the second copolymer (M2) is 5% by mass or more and 30% by mass or less. A method for producing an adhesive composition. The adhesive composition according to any one of claims 1 to 12 , wherein the hydrogenated block copolymer (A) has a functional group. The surface protection film in which the layer of the adhesive composition as described in any one of Claims 1 thru | or 12 and 16 of thickness 1 micrometer-100 micrometers is provided on the base film at least one layer.