JP7415511B2 - Adhesives for surface protection materials and surface protection materials - Google Patents

Description

The present invention relates to an adhesive for a surface protection material and a surface protection material, and more specifically to a surface protection material that has well-balanced adhesiveness and spreadability, suppresses increase in adhesive strength, and has excellent thermal stability. The present invention relates to an adhesive for a surface protection material, which can provide a surface protection material, and a surface protection material having an adhesive layer made of the adhesive.

Surface protection products such as surface protection films, surface protection sheets, and surface protection tapes are used to protect the surfaces of various products from damage caused by dirt, dust, and contact with other objects during storage and transportation. The material is widely used. Surface protection materials generally have a structure in which an adhesive layer made of an adhesive is laminated on a base material such as resin, and is applied to the article so that the adhesive layer is in contact with the surface of the article to be protected. Used by pasting.

As an adhesive for such a surface protection material, for example, Patent Document 1 discloses a block copolymer composition containing a specific block copolymer A and a specific block copolymer B in a specific ratio. , and a tackifying resin have been disclosed. According to the technology of Patent Document 1, it has excellent adhesiveness and spreadability, and furthermore, the adhesive strength increases (a phenomenon in which the adhesive strength gradually becomes stronger as time passes while it is attached to an article). It is possible to provide a pressure-sensitive adhesive for a surface protection material, which can provide a surface protection material that is well suppressed and does not easily leave adhesive residue when peeled off from the object to be protected. On the other hand, in Patent Document 1, the thermal stability of the surface protection material is not studied.

Further, Patent Document 2 discloses that a specific multi-block copolymer having an aromatic alkenyl polymer block and an aromatic alkenyl-conjugated diene copolymer block is used in the adhesive layer, and a tackifier and a softener are added to the adhesive layer. A pressure-sensitive adhesive composition formed by blending in a fixed amount is disclosed. According to the technique of Patent Document 2, it is possible to provide a pressure-sensitive adhesive composition that has excellent spreadability and can suppress adhesive residue after peeling off to an adherend while ensuring appropriate initial adhesive strength. However, it is desired to further improve the adhesiveness and spreadability, and at the same time, it is also desired to improve the thermal stability of the surface protection material obtained.

Japanese Patent Application Publication No. 2014-167074 Japanese Patent Application Publication No. 2012-111793

The present invention provides an adhesive for a surface protection material that has well-balanced adhesion and spreadability, suppresses increase in adhesion strength, and can provide a surface protection material with excellent thermal stability. The purpose is to

The present inventors conducted studies to achieve the above object, and found that a hydrogenated block copolymer composition containing two types of hydrogenated block copolymers having a specific structure and a tackifying resin. In the adhesive for surface protection materials, the weight ratio of two types of hydrogenated block copolymers having a specific structure is set in a specific range, and the olefin in the polymer component constituting the hydrogenated block copolymer composition is By controlling the hydrogenation rate within a specific range, the surface protection material obtained using this material has excellent adhesion and spreadability in a well-balanced manner, the increase in adhesion is well suppressed, and the material has excellent thermal stability. The present inventors have discovered that the present invention is excellent in the following.

That is, according to the present invention, a hydrogenated block copolymer having a hydrogenated block copolymer A represented by the following general formula (A) and a hydrogenated block copolymer B represented by the following general formula (B) A pressure-sensitive adhesive for a surface protection material comprising a combination composition and a tackifying resin, the hydrogenated block copolymer A and the hydrogenated block copolymer in the hydrogenated block copolymer composition. The weight ratio (A/B) with coalescence B is 10/90 to 80/20, and the hydrogenation rate of the olefin in the polymer component constituting the hydrogenated block copolymer composition is 10 to 100%. A surface protection adhesive is provided.
Ar1 ^a -HD ^a -Ar2 ^a (A)
Ar1 ^b -HD ^b -Ar2 ^b (B)
(In the general formulas (A) and (B) above, Ar1 ^a , Ar2 ^a , Ar1 ^b , and Ar2 ^b are aromatic vinyl polymer blocks, and HD ^a and HD ^b are conjugated diene polymer blocks. It is a hydrogenated polymer block, and the ratio of the weight average molecular weight (Mw (Ar2 ^a )) of Ar2 ^a to the weight average molecular weight (Mw (Ar1 ^a )) of Ar1 ^a (Mw (Ar2 ^a )/Mw (Ar1 ^a ) ) is 2.6 to 66.)

In the adhesive for surface protection materials of the present invention, the proportion of aromatic vinyl monomer units in the total repeating units of the polymer component of the hydrogenated block copolymer composition is 20 to 70% by weight. is preferred.
In the adhesive for surface protection materials of the present invention, the weight average molecular weights of Ar1 ^a , Ar1 ^b , and Ar2 ^b in the general formula (A) and general formula (B) of the hydrogenated block copolymer composition are The weight average molecular weights of HD ^a and HD ^b are preferably in the range of 15,000 to 300,000, respectively.
In the adhesive for surface protection materials of the present invention, HD ^a and HD ^b in the general formula (A) and general formula (B) of the hydrogenated block copolymer composition each have a vinyl bond content of 1. It is preferably 20 mol%.
In the adhesive for surface protection materials of the present invention, the content of the tackifying resin is preferably 1 to 100 parts by weight based on 100 parts by weight of the hydrogenated block copolymer composition.

Further, according to the present invention, there is provided a surface protection material in which an adhesive layer made of any of the above adhesives for surface protection materials and a base material layer made of resin are laminated.

According to the present invention, there is provided an adhesive for a surface protection material that is excellent in adhesion and spreadability in a well-balanced manner, that increases in adhesion strength is well suppressed, and that can provide a surface protection material that has excellent thermal stability. can be provided.

<Adhesive for surface protection materials>
The adhesive for surface protection materials of the present invention comprises a hydrogenated block copolymer A represented by the general formula (A) described later, and a hydrogenated block copolymer B represented by the general formula (B) described later. An adhesive for a surface protection material, comprising a hydrogenated block copolymer composition containing: and a tackifier resin,
In the hydrogenated block copolymer composition, the weight ratio (A/B) of the hydrogenated block copolymer A and the hydrogenated block copolymer B is 10/90 to 80/20,
The hydrogenation rate of olefin in the polymer component constituting the hydrogenated block copolymer composition is 10 to 100%.

The hydrogenated block copolymer composition used in the present invention comprises a hydrogenated block copolymer A represented by the following general formula (A) and a hydrogenated block copolymer B represented by the following general formula (B). It contains.
Ar1 ^a -HD ^a -Ar2 ^a (A)
Ar1 ^b -HD ^b -Ar2 ^b (B)

In the above general formula (A), Ar1 ^a and Ar2 ^a are aromatic vinyl polymer blocks, and the weight average molecular weight (Mw (Ar2 ^a )) of Ar2 ^a is the weight average molecular weight (Mw (Ar2 ^{a )) of Ar1 a .} )) ratio (Mw(Ar2 ^a )/Mw(Ar1 ^a )) is 2.6 to 66. Moreover, HD ^a is a hydrogenated polymer block of a conjugated diene polymer.

Furthermore, in the general formula (B), Ar1 ^b and Ar2 ^b are aromatic vinyl polymer blocks, and HD ^b is a hydrogenated polymer block of a conjugated diene polymer.

The aromatic vinyl polymer blocks Ar1 ^a , Ar2 ^a , Ar1 ^b , and Ar2 ^b of hydrogenated block copolymer A and hydrogenated block copolymer B are polymer blocks composed of aromatic vinyl monomer units. be.

The aromatic vinyl monomer used to constitute the aromatic vinyl monomer unit is not particularly limited as long as it is an aromatic vinyl compound. Examples of aromatic vinyl compounds include styrene; α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2,4- Styrenes substituted with alkyl groups such as diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene; 2-chlorostyrene, 3-chlorostyrene, 4- Examples include styrenes substituted with halogen atoms such as chlorostyrene, 4-bromostyrene, 2-methyl-4,6-dichlorostyrene, and 2,4-dibromostyrene; vinylnaphthalene; and the like. Among these, it is preferable to use styrene. These aromatic vinyl monomers can be used alone or in combination of two or more types in each aromatic vinyl polymer block. Moreover, in each aromatic vinyl polymer block, the same aromatic vinyl monomer may be used, or different aromatic vinyl monomers may be used.

Further, the aromatic vinyl polymer blocks Ar1 ^a , Ar2 ^a , Ar1 ^b , and Ar2 b constituting the hydrogenated block copolymer A and the hydrogenated block copolymer ^B each contain other than aromatic vinyl monomer units. may contain monomeric units. Monomers constituting monomer units other than aromatic vinyl monomer units include conjugated diene monomers such as 1,3-butadiene and isoprene (2-methyl-1,3-butadiene); α, Examples include β-unsaturated nitrile monomers; unsaturated carboxylic acid or acid anhydride monomers; unsaturated carboxylic acid ester monomers; non-conjugated diene monomers.

The content of monomer units other than aromatic vinyl monomer units in each aromatic vinyl polymer block is preferably 20% by weight or less, and 10% by weight based on the entire aromatic vinyl polymer block. It is more preferable that it is below, and it is especially preferable that it is substantially 0% by weight.

The hydrogenated polymer blocks HD ^a and HD b of the conjugated diene polymer constituting the hydrogenated block copolymer A and the hydrogenated block copolymer ^B are polymer blocks composed of conjugated diene monomer units. At least a portion of the conjugated diene monomer units constituting the polymer block are hydrogenated.

The conjugated diene monomer used to constitute the conjugated diene monomer unit is not particularly limited as long as it is a conjugated diene compound. Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, etc. can be mentioned. Among these, from the viewpoint of polymerization reactivity, it is preferable to use 1,3-butadiene and/or isoprene, and it is particularly preferable to use isoprene. These conjugated diene monomers can be used alone or in combination of two or more types in each hydrogenated polymer block. Moreover, in each hydrogenated polymer block, the same conjugated diene monomer may be used, or different conjugated diene monomers may be used.

The hydrogenated polymer blocks HD ^a and HD b of the conjugated diene polymer constituting the hydrogenated block copolymer A and the hydrogenated block copolymer ^B each contain monomer units other than conjugated diene monomer units. May contain. Monomers constituting monomer units other than conjugated diene monomer units include aromatic vinyl monomers such as styrene and α-methylstyrene; α, β-unsaturated nitrile monomers; unsaturated carbon Examples include acid or acid anhydride monomers; unsaturated carboxylic acid ester monomers; non-conjugated diene monomers; and the like.

The content of monomer units other than conjugated diene monomer units in each hydrogenated polymer block is preferably 20% by weight or less, and preferably 10% by weight or less, based on the entire conjugated diene polymer block. is more preferred, and substantially 0% by weight is particularly preferred.

The hydrogenated block copolymer A constituting the hydrogenated block copolymer composition has a ratio of the weight average molecular weight of Ar2 ^a (Mw(Ar2 ^a )) to the weight average molecular weight of Ar1 ^a (Mw(Ar1 ^a )). (Mw(Ar2 ^a )/Mw(Ar1 ^a )) is in the range of 2.6 to 66, and therefore the aromatic vinyl polymer block Ar1 ^a and the conjugated diene polymer have a relatively small weight average molecular weight. A ^hydrogenated polymer block HD ^a of It is a hydride of a polymer.

In hydrogenated block copolymer A, Mw(Ar2 ^a )/Mw(Ar1 ^a ) is in the range of 2.6 to 66, preferably in the range of 4 to 40, more preferably in the range of 4.5 to 35. It is. If Mw(Ar2 ^a )/Mw(Ar1 ^a ) is too small or too large, the surface protection material obtained will have poor adhesiveness and spreadability. In the present invention, the weight average molecular weight of a polymer or a polymer block is determined as a polystyrene equivalent value by measurement using high performance liquid chromatography.

The weight average molecular weight (Mw(Ar1 ^a )) of the aromatic vinyl polymer block Ar1 ^a having a relatively small weight average molecular weight constituting the hydrogenated block copolymer A is preferably 2,000 to 40, 000, more preferably 2,500 to 30,000, still more preferably 3,000 to 10,000. By setting Mw (Ar1 ^a ) within the above range, the resulting surface protection material can have better adhesiveness and spreadability.

Further, the weight average molecular weight (Mw(Ar2 ^a )) of the aromatic vinyl polymer block Ar2 ^a having a relatively large weight average molecular weight constituting the hydrogenated block copolymer A is preferably 5,000 to 250, 000, more preferably 8,000 to 120,000, still more preferably 10,000 to 80,000. By setting Mw (Ar2 ^a ) within the above range, the obtained surface protection material can be made to have an increase in adhesive strength that is further suppressed.

Vinyl bond content of hydrogenated polymer block HD ^a of conjugated diene polymer constituting hydrogenated block copolymer A (1,2-vinyl bond and 3,4-vinyl bond in all conjugated diene monomer units) The proportion occupied by bonds is preferably 0.1 to 50 mol%, more preferably 1 to 20 mol%, even more preferably 2 to 15 mol%, particularly preferably 3 to 10 mol%. be. By setting the vinyl bond content within the above range, the resulting surface protection material can have better adhesiveness.

The weight average molecular weight (Mw (HD ^a )) of the hydrogenated polymer block HD ^a of the conjugated diene polymer constituting the hydrogenated block copolymer A is preferably 10,000 to 300,000, more preferably is 15,000 to 300,000, more preferably 15,000 to 150,000, particularly preferably 20,000 to 80,000.

The content of aromatic vinyl monomer units based on all monomer units of hydrogenated block copolymer A is not particularly limited, but is preferably 10 to 35% by weight, more preferably 12 to 32% by weight, More preferably, it is 15 to 30% by weight.

The weight average molecular weight of the hydrogenated block copolymer A as a whole is also not particularly limited, but is preferably 20,000 to 500,000, more preferably 25,000 to 300,000, even more preferably 30,000 to 150, It is 000.

Further, hydrogenated block copolymer B constituting the hydrogenated block copolymer composition has two aromatic vinyl polymer blocks Ar1 ^b and Ar2 ^b bonded to both ends of the conjugated diene polymer block HD ^b , respectively. This is a hydrogenated product of an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer.

The weight average molecular weights (Mw(Ar1 ^b ), Mw(Ar2 ^b )) of the two aromatic vinyl polymer blocks Ar1 ^b and Ar2 ^b constituting the hydrogenated block copolymer B are preferably 2,000, respectively. ~40,000, more preferably 2,500~30,000, still more preferably 3,000~10,000. By setting Mw (Ar1 ^b ) and Mw (Ar2 ^b ) within the above ranges, the resulting surface protection material can have better adhesiveness and spreadability. As long as the weight average molecular weights (Mw(Ar1 ^b ), Mw(Ar2 ^b )) of the two aromatic vinyl polymer blocks Ar1 ^b and Ar2 ^b are within the above range, even if they are equal to each other, they may be different from each other. However, it is preferable that they be substantially the same. For example, if the ratio (Mw(Ar2 ^b )/Mw(Ar1 ^b )) of the weight average molecular weight (Mw(Ar2 ^b )) of Ar2 ^b to the weight average molecular weight (Mw(Ar1 ^b )) of Ar1 ^b is 0.95 to It is preferably in the range of 1.05.

Furthermore, at least one of these two aromatic vinyl polymer blocks Ar1 ^b and Ar2 ^b has a weight average molecular weight (Mw (Ar1 ^b ), Mw (Ar2 ^b )) that is similar to that of the hydrogenated block. It is more preferable that it is substantially equal to the weight average molecular weight (Mw(Ar1 ^a )) of the aromatic vinyl polymer block Ar1 ^a that constitutes the polymer A and has a relatively small weight average molecular weight. For example, the ratio (Mw(Ar1 ^b )/Mw(Ar1 ^a )) of the weight average molecular weight (Mw(Ar1 ^b )) of Ar1 ^b to the weight average molecular weight (Mw(Ar1 ^a )) of Ar1 ^a is 0.95 to ^{1.05, or the ratio (Mw(Ar2 b ) / Mw (} Preferably, Ar1 ^a )) is in the range of 0.95 to 1.05.

The vinyl bond content of the hydrogenated polymer block HD ^b of the conjugated diene polymer constituting the hydrogenated block copolymer B (1,2-vinyl bond and 3,4-vinyl bond in all conjugated diene monomer units) The proportion occupied by bonds is preferably 0.1 to 50 mol%, more preferably 1 to 20 mol%, even more preferably 2 to 15 mol%, particularly preferably 3 to 10 mol%. be. By setting the vinyl bond content within the above range, the resulting surface protection material can have better adhesiveness. In addition, the vinyl bond content of the hydrogenated polymer block HD b of the conjugated diene polymer constituting the hydrogenated block copolymer ^B is the same as the vinyl bond content of the hydrogenated polymer block HD b of the conjugated diene polymer constituting the hydrogenated block copolymer A. Preferably, it is substantially equal to the vinyl bond content of the polymer block HD ^a .

In addition, when producing the hydrogenated block copolymer composition used in the present invention, for example, when employing a method for producing a hydrogenated block copolymer composition having steps (1a) to (6a) described below. When adopting a manufacturing method using a coupling agent such ^as It may be something that does. Specifically, hydrogenated block copolymer B may be a compound represented by the following formula.
Ar1 ^b - (HD ^b' -X-HD ^b'' ) - Ar2 ^b
That is, as shown in the above formula, the hydrogenated polymer block HD ^b of the conjugated diene polymer is formed by coupling HD ^b' and HD ^b'' through the residue X of the coupling agent. It may be an aspect. In addition, as the coupling agent residue Examples include.

The weight average molecular weight (Mw (HD ^b )) of the hydrogenated polymer block HD ^b of the conjugated diene polymer constituting the hydrogenated block copolymer B is preferably 10,000 to 300,000, more preferably is 15,000 to 300,000, more preferably 15,000 to 150,000, particularly preferably 20,000 to 80,000.

The content of aromatic vinyl monomer units based on all monomer units of hydrogenated block copolymer B is not particularly limited, but is preferably 35 to 90% by weight, more preferably 40 to 87% by weight, More preferably, it is 43 to 85% by weight.

The weight average molecular weight of the hydrogenated block copolymer B as a whole is also not particularly limited, but is preferably 20,000 to 200,000, more preferably 25,000 to 150,000, even more preferably 30,000 to 70, It is 000.

The weight average molecular weight (Mw) of hydrogenated block copolymer A and hydrogenated block copolymer B constituting the hydrogenated block copolymer composition used in the present invention, and each polymer block constituting these. The molecular weight distribution represented by the ratio [(Mw)/(Mn)] to the number average molecular weight (Mn) is not particularly limited, but each is preferably 1.1 or less, more preferably 1.05 or less. be.

The weight ratio (A/B) of hydrogenated block copolymer A and hydrogenated block copolymer B contained in the hydrogenated block copolymer composition used in the present invention is 10/90 to 80/20. Yes, preferably 12/88 to 60/40, more preferably 15/85 to 50/50. By containing hydrogenated block copolymer A and hydrogenated block copolymer B in such a ratio, the resulting surface protection material can be made to be excellent in well-balanced adhesiveness and spreadability. . If the weight ratio (A/B) is too small, the resulting surface protective material will tend to have increased adhesive strength, and if the weight ratio (A/B) is too large, the resulting surface protective material will have insufficient adhesiveness. Become something.

Furthermore, the hydrogenated block copolymer composition used in the present invention is one in which the hydrogenation rate of olefin in the polymer components constituting the hydrogenated block copolymer composition is in the range of 10 to 100%. Here, the hydrogenation rate of olefin is the hydrogenation rate of olefin in all polymer components constituting the hydrogenated block copolymer composition, and specifically, It is the percentage (mol%) of hydrogenated bonds among all non-aromatic carbon-carbon double bonds included. The present inventors conducted extensive studies and found that hydrogenated block copolymer compositions include hydrogenated block copolymer A represented by the above general formula (A) and hydrogenated block copolymer A represented by the above general formula (B). By containing hydrogenated block copolymer B in a specific weight ratio and having a hydrogenation rate of olefin in the hydrogenated block copolymer composition within the above range, this It has been discovered that the adhesive for surface protection materials obtained using the method can be made into a surface protection material that has well-balanced adhesiveness and spreadability, and also has excellent thermal stability. be. In particular, according to the present invention, hydrogenated block copolymer A represented by the above general formula (A) and a hydrogenated block represented by the above general formula (B) are used as hydrogenated block copolymer compositions. By containing Copolymer B in a specific weight ratio, it is possible to obtain an effect of improving thermal stability due to hydrogenation, thereby improving the adhesiveness and spreadability of the surface protection material obtained. In addition, the adhesive strength can be well-balanced, the increase in adhesive strength can be suppressed well, and the thermal stability can be improved.

The hydrogenation rate of olefin in the polymer component constituting the hydrogenated block copolymer composition used in the present invention may be in the range of 10 to 100%, preferably 30 to 100%, and more preferably is 70 to 100%, more preferably 90 to 100%. If the hydrogenation rate of the olefin is too low, the resulting surface protective material will have insufficient thermal stability.

Further, the hydrogenated block copolymer composition used in the present invention may have an olefin hydrogenation rate within the above range, but the iodine value in the polymer component constituting the hydrogenated block copolymer composition is 0. It is preferably within the range of ~300gI ₂ /100g, more preferably within the range of 0-150gI ₂ /100g, even more preferably within the range of 0-125gI ₂ /100g, and even more preferably within the range of 0-90gI ₂ It is even more preferably within the range of /100g, and particularly preferably within the range of 0 to 30gI ₂ /100g. If the iodine value is within the above range, the resulting surface protection material will have better thermal stability.

The hydrogenated block copolymer composition used in the present invention may contain only hydrogenated block copolymer A and hydrogenated block copolymer B as polymer components, but this may impair the effects of the present invention. It may contain polymer components other than hydrogenated block copolymer A and hydrogenated block copolymer B, as long as they are not included.

As polymer components other than hydrogenated block copolymer A and hydrogenated block copolymer B that may be contained in the hydrogenated block copolymer composition used in the present invention, hydrogenated block copolymer A and hydrogenated block Aromatic vinyl-conjugated diene-aromatic vinyl block copolymer other than copolymer B, aromatic vinyl-conjugated diene block copolymer, aromatic vinyl homopolymer, conjugated diene homopolymer, aromatic vinyl-conjugated Diene random copolymers and branched polymers thereof; Thermoplastic elastomers such as polyurethane thermoplastic elastomers, polyamide thermoplastic elastomers, polyester thermoplastic elastomers; polyethylene, polypropylene, polyvinyl chloride, acrylonitrile-styrene copolymers thermoplastic resins such as polymers, acrylonitrile-butadiene-styrene copolymers, and polyphenylene ethers.

In the hydrogenated block copolymer composition used in the present invention, the content of polymer components other than hydrogenated block copolymer A and hydrogenated block copolymer B is 20% by weight based on the entire polymer component. It is preferably at most 10% by weight, more preferably at most 10% by weight.

In the hydrogenated block copolymer composition used in the present invention, the aromatic vinyl monomer is The proportion occupied by the aromatic vinyl monomer unit (hereinafter sometimes referred to as "total aromatic vinyl monomer unit content") is preferably 20 to 70% by weight, more preferably 25 to 60% by weight, and even more preferably 30 to 50% by weight, particularly preferably 32 to 50% by weight. By setting the total aromatic vinyl monomer unit content within the above range, the resulting surface protective material can be made to have better suppressed increase in adhesive strength. The total aromatic vinyl monomer unit content is the aroma of hydrogenated block copolymer A, hydrogenated block copolymer B, and other polymer components constituting the hydrogenated block copolymer composition. It can be easily adjusted by taking into account the content of group vinyl monomer units and adjusting their blending amounts.

In addition, when all the polymer components constituting the hydrogenated block copolymer composition are composed only of aromatic vinyl monomer units and conjugated diene monomer units, Rubber Chem. Technol. , 45, 1295 (1972), the polymer components in the hydrogenated block copolymer composition are ozonolyzed and then reduced with lithium aluminum hydride to obtain conjugated diene monomer units. Since the portion (including the hydrogenated portion) is decomposed and only the aromatic vinyl monomer unit portion can be taken out, the total aromatic vinyl monomer unit content can be easily measured.

The weight average molecular weight of the entire polymer component constituting the hydrogenated block copolymer composition used in the present invention is not particularly limited, but is preferably 30,000 to 400,000, more preferably 35,000 to 100. ,000, more preferably 40,000 to 80,000.

In addition, the molecular weight distribution represented by the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the entire polymer component constituting the hydrogenated block copolymer composition used in the present invention is Although not particularly limited, it is preferably 1.01 to 10, more preferably 1.02 to 5, and even more preferably 1.03 to 3.

The method for producing the hydrogenated block copolymer composition used in the present invention is not particularly limited. For example, hydrogenated block copolymer A and water By manufacturing the additive block copolymer B separately, blending other polymer components and various additives as necessary, and then mixing them according to conventional methods such as kneading or solution mixing. can be manufactured. On the other hand, in the present invention, the production method described below is preferable from the viewpoint that the hydrogenated block copolymer composition can be produced with high productivity.

That is, the method for producing the hydrogenated block copolymer composition used in the present invention is preferably a production method having the following steps (1) to (7).
(1): Step of obtaining a solution containing an aromatic vinyl polymer having an active end by polymerizing an aromatic vinyl monomer using a polymerization initiator in a solvent (2): (1) above By adding a conjugated diene monomer to a solution containing an aromatic vinyl polymer having an active end obtained in the step and polymerizing the conjugated diene monomer, an aromatic vinyl conjugate having an active end is obtained. Step (3) of obtaining a solution containing a diene block copolymer: An aromatic vinyl monomer is added to the solution containing the aromatic vinyl-conjugated diene block copolymer having an active end obtained in step (2) above. Step (4) of obtaining a solution containing an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end by adding and polymerizing the aromatic vinyl monomer: (3) ) A polymerization terminator is added to the solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end obtained in step ) in an amount less than 1 molar equivalent with respect to the active end. Step (5) of deactivating a part of the active end of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end to obtain a solution containing the block copolymer B': By adding an aromatic vinyl monomer to the solution containing block copolymer B' obtained in step 4) and polymerizing the aromatic vinyl monomer, block copolymer B' and Step (6) of obtaining a solution containing block copolymer A': A hydrogenation reaction is performed on the solution containing block copolymer B' and block copolymer A' obtained in step (5) above. Step (7) of obtaining a solution containing hydrogenated block copolymer B and hydrogenated block copolymer A: Hydrogenated block copolymer B and hydrogenated block copolymer B obtained in step (6) above. Step of recovering a hydrogenated block copolymer composition from a solution containing polymer A

<Step (1)>
In this method for producing a hydrogenated block copolymer composition, first, in step (1), an aromatic vinyl monomer having an active end is polymerized using a polymerization initiator in a solvent. A solution containing vinyl polymer is obtained.

As the polymerization initiator, a polymerization initiator known to have anionic polymerization activity toward aromatic vinyl monomers and conjugated diene monomers can be used. Examples of the polymerization initiator include organic alkali metal compounds, organic alkaline earth metal compounds, and organic lanthanoid rare earth metal compounds.

As the organic alkali metal compound, an organic lithium compound having one or more lithium atoms in the molecule is particularly preferably used. Specific examples of organic alkali metal compounds include ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, phenyllithium, stilbenelithium, dialkylaminolithium, and diphenyl. Organic monolithium compounds such as aminolithium and ditrimethylsilylaminolithium; organic dilithium compounds such as methylene dilithium, tetramethylene dilithium, hexamethylene dilithium, isoprenyl dilithium, and 1,4-dilithio-ethylcyclohexane; Examples include organic trilithium compounds such as 1,3,5-trilithiobenzene. Among these, organic monolithium compounds are particularly preferably used.

Examples of organic alkaline earth metal compounds include n-butylmagnesium bromide, n-hexylmagnesium bromide, ethoxycalcium, calcium stearate, t-butoxystrontium, ethoxybarium, isopropoxybarium, ethylmercaptobarium, t-butoxybarium, Examples include phenoxybarium, diethylaminobarium, barium stearate, and ethylbarium.

In addition to the above, we also offer composite catalysts consisting of lanthanide rare earth metal compounds containing neodymium, samarium, gadolinium, etc./alkylaluminum/alkylaluminum halides/alkylaluminum hydrides, metallocene type catalysts containing titanium, vanadium, samarium, gadolinium, etc. It is also possible to use those that form a homogeneous system in an organic solvent and have living polymerizability.

The above polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator to be used may be determined depending on the molecular weight of each target block copolymer, and is not particularly limited, but is preferably 0.01 to 20 mmol per 100 g of total monomers used for polymerization. The amount is more preferably 0.05 to 15 mmol, and even more preferably 0.1 to 10 mmol.

The solvent used for polymerization may be any solvent as long as it is inert to the polymerization initiator, and is not particularly limited, and examples thereof include a chain hydrocarbon solvent, a cyclic hydrocarbon solvent, or a mixed solvent thereof. Examples of the chain hydrocarbon solvent include n-butane, isobutane, 1-butene, isobutylene, trans-2-butene, cis-2-butene, 1-pentene, trans-2-pentene, cis-2-pentene, Examples include linear alkanes and alkenes having 4 to 6 carbon atoms, such as n-pentane, isopentane, neo-pentane, and n-hexane. Examples of the cyclic hydrocarbon solvent include aromatic compounds such as benzene, toluene, and xylene; and alicyclic hydrocarbon compounds such as cyclopentane and cyclohexane. These solvents may be used alone or in combination of two or more.

The amount of the solvent to be used is not particularly limited, but it is preferable that the concentration of the total block copolymer in the solution after the polymerization reaction is from 5 to 60% by weight, and preferably from 10 to 55% by weight. More preferably, the amount is 20 to 50% by weight.

Furthermore, when producing the hydrogenated block copolymer composition, a Lewis base compound may be added to the reaction system in order to control the structure of each polymer block of each block copolymer. Examples of Lewis base compounds include ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, and diethylene glycol dibutyl ether; tertiary amines such as tetramethylethylenediamine, trimethylamine, triethylamine, pyridine, and quinuclidine. alkali metal alkoxides such as potassium-t-amyl oxide and potassium-t-butyl oxide; phosphines such as triphenylphosphine; and the like. These Lewis base compounds may be used alone or in combination of two or more.

When producing a hydrogenated block copolymer composition, the timing of adding the Lewis base compound is not particularly limited, and may be appropriately determined depending on the structure of each target block copolymer. For example, it may be added in advance before starting polymerization, or it may be added after some polymer blocks have been polymerized. Furthermore, it may be added in advance before starting polymerization, or may be further added after some polymer blocks have been polymerized.

The polymerization reaction temperature is preferably 10 to 150°C, more preferably 30 to 130°C, even more preferably 40 to 90°C, and the polymerization time is preferably within 48 hours, more preferably 0.5 to 10 hours. be. Further, the polymerization pressure is not particularly limited as long as it is within a pressure range sufficient to maintain the monomer and solvent in a liquid phase at the polymerization temperature.

By polymerizing an aromatic vinyl monomer using a polymerization initiator in a solvent under the above conditions, a solution containing an aromatic vinyl polymer having an active terminal can be obtained. In this way, the aromatic vinyl polymer having active terminals obtained in step (1) has a relatively low weight average molecular weight of the hydrogenated block copolymer A constituting the hydrogenated block copolymer composition. The aromatic vinyl polymer block Ar1 ^a and the aromatic vinyl polymer block Ar1 ^b and Ar2 ^b of the hydrogenated block copolymer B (i.e., Ar1 ^b or Ar2 ^b ) will be constituted by be. Therefore, each polymerization condition including the amount of aromatic vinyl monomer in step (1) may be determined depending on the intended weight average molecular weight of these polymer blocks.

<Step (2)>
Next, in step (2), a conjugated diene monomer is added to the solution containing the aromatic vinyl polymer having an active end obtained in the above step (1), and the conjugated diene monomer is polymerized. By doing so, a solution containing an aromatic vinyl-conjugated diene block copolymer having an active end is obtained.

According to step (2), a conjugated diene monomer is added to the solution containing the aromatic vinyl polymer having an active end obtained in the above step (1), thereby forming a conjugate starting from the active end. A diene polymer chain is formed, which makes it possible to obtain a solution containing an aromatic vinyl-conjugated diene block copolymer with active ends.

The conjugated diene polymer chain formed in step (2) (the conjugated diene block constituting the aromatic vinyl-conjugated diene block copolymer having an active end obtained in step (2)) is a hydrogenated block copolymer. This constitutes the hydrogenated polymer block HD ^a of the conjugated diene polymer of the coalescence A and the hydrogenated polymer block HD ^b of the conjugated diene polymer of the hydrogenated block copolymer B. Therefore, each polymerization condition including the amount of the conjugated diene polymer in step (2) may be determined depending on the target weight average molecular weight of these polymer blocks (for example, the polymerization conditions may be determined as described above). It may be determined within the range explained in step (1).)

<Step (3)>
Next, in step (3), an aromatic vinyl monomer is added to the solution containing the aromatic vinyl-conjugated diene block copolymer having an active end obtained in step (2) above, and the aromatic vinyl monomer is By polymerizing group vinyl monomers, a solution containing an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end is obtained.

According to step (3), an aromatic vinyl monomer is added to the solution containing the aromatic vinyl-conjugated diene block copolymer having an active end obtained in step (2) above, thereby increasing the activity. Starting from the end, an aromatic vinyl polymer chain is formed, thereby making it possible to obtain a solution containing an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end.

The aromatic vinyl polymer chain formed in step (3) (the aromatic vinyl block constituting the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end obtained in step (3)) is , one of the aromatic vinyl polymer blocks Ar1 ^b and Ar2 ^b of hydrogenated block copolymer B (i.e., one of Ar1 ^b and Ar2 ^b is a block different from the block formed in step (1), For example, when Ar1 ^b is formed in step (1), Ar2 ^b corresponds to this.). Therefore, each polymerization condition including the amount of aromatic vinyl monomer in step (3) may be determined depending on the target weight average molecular weight of such a polymer block (for example, the polymerization conditions may be , may be determined within the range described in step (1) above.)

<Step (4)>
Next, in step (4), a solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end obtained in the above step (3) is added at 1 mol based on the active end. A polymerization terminator is added in an amount less than the equivalent amount to deactivate a part of the active end of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end, thereby forming the block copolymer B'. Obtain a solution containing:

The block copolymer B' obtained in step (4) is a block copolymer before hydrogenation to obtain hydrogenated block copolymer B.

The polymerization terminator is not particularly limited as long as it can deactivate the active end by reacting with the active end, and does not react with another active end after reacting with one active end, and is not particularly limited. A polymerization terminator that produces a metal alkoxide, metal aryloxide, or metal hydroxide when reacting with an active terminal is particularly preferable. Specific examples of the polymerization terminator include water; monohydric alcohols such as methanol and ethanol; monohydric phenols such as phenol and cresol; and the like.

The amount of the polymerization terminator used may be determined depending on the ratio of hydrogenated block copolymer A and hydrogenated block copolymer B constituting the hydrogenated block copolymer composition. The amount of the polymerization terminator used is not particularly limited as long as it is less than 1 molar equivalent relative to the active end of the polymer, but the amount of the polymerization terminator used may be in the range of 0.18 to 0.91 molar equivalent relative to the active end of the polymer. Preferably, the molar equivalent range is from 0.35 to 0.80.

As described above, according to step (4), the solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having an active end has a content of less than 1 molar equivalent with respect to the active end. By adding a polymerization terminator in a certain amount, some of the active ends of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer are deactivated, and the active ends are deactivated. The deactivated copolymer becomes a block copolymer B' before hydrogenation to constitute hydrogenated block copolymer B. The remaining part of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having active ends that did not react with the polymerization terminator remains unreacted and remains in the solution while maintaining the active ends. will remain.

<Step (5)>
Next, in step (5), an aromatic vinyl monomer is added to the solution containing the block copolymer B' obtained in the above step (4), and the aromatic vinyl monomer is polymerized. By doing so, a solution containing block copolymer B' and block copolymer A' is obtained.

According to step (5), when the aromatic vinyl monomer is added to the solution obtained in the above step (4), the aromatic vinyl-conjugated diene having an active end that did not react with the polymerization terminator remained. An aromatic vinyl monomer is further polymerized from the aromatic vinyl polymer chain on the side having the active end of the aromatic vinyl block copolymer, and the aromatic vinyl polymer chain is extended, thereby forming a block copolymer. A combination A' is obtained. Note that block copolymer A' is an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer obtained by extending the aromatic vinyl polymer chain, and hydrogenated block copolymer A is obtained. This is a block copolymer before hydrogenation.

At this time, in step (5), the aromatic vinyl polymer chain to be extended is an aromatic vinyl polymer chain having a relatively large weight average molecular weight of the hydrogenated block copolymer A constituting the hydrogenated block copolymer composition. This constitutes a vinyl polymer block ^Ar2a . Therefore, each polymerization condition including the amount of aromatic vinyl monomer in step (5) may be determined depending on the desired weight average molecular weight of such aromatic vinyl polymer block ^Ar2a ( For example, the polymerization conditions may be determined within the range described in step (1) above.)

<Step (6)>
Next, in step (6), the hydrogenated block copolymer is A solution containing coalesce B and hydrogenated block copolymer A is obtained.

The method for carrying out the hydrogenation reaction on the solution containing block copolymer B' and block copolymer A' is not particularly limited, but for example, in the presence of a hydrogenation catalyst, block copolymer B' and Examples include a method in which a solution containing block copolymer A' is brought into contact with hydrogen.

Examples of hydrogenation catalysts include, but are not limited to, supported heterogeneous catalysts in which metals such as Ni, Pt, Pd, and Ru are supported on carriers such as carbon, silica, alumina, and diatomaceous earth; Ziegler type catalyst using an organic salt such as , Fe, Cr or acetylacetone salt and a reducing agent such as organic Al; an organic complex catalyst such as an organometallic compound such as Ru or Rh; a titanocene compound using organic Li or organic Al as a reducing agent. , a homogeneous catalyst using organic Mg, etc. Among these, Ziegler type catalysts are preferred.

The hydrogenation reaction may be carried out according to the method disclosed in, for example, Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Application Laid-Open No. 59-133203, Japanese Patent Application Laid-open No. 60-220147, etc. I can do it.

The hydrogenation reaction conditions may be selected depending on the hydrogenation rate of the olefin in the polymer components constituting the hydrogenated block copolymer composition, but the hydrogenation reaction temperature is preferably 0 to 200°C. The temperature is more preferably 30 to 150°C. Further, the pressure of hydrogen used in the hydrogenation reaction is preferably 0.1 to 15 MPa, more preferably 0.2 to 10 MPa, even more preferably 0.3 to 5 MPa, and the hydrogenation reaction time is The time is preferably 3 minutes to 10 hours, more preferably 10 minutes to 5 hours. Note that the hydrogenation reaction may be a batch process, a continuous process, or a combination thereof.

<Step (7)>
Next, in step (7), a desired hydrogenated block copolymer composition is obtained from the solution containing hydrogenated block copolymer B and hydrogenated block copolymer A obtained in step (6) above. Collect.

The method of recovery may be any conventional method and is not particularly limited. For example, after the reaction is completed, a polymerization terminator is added as necessary to deactivate the active end of the polymer having an active end, and further additives such as an antioxidant are added as necessary. The desired hydrogenated block copolymer composition can be recovered from the solution by applying a known solvent method such as direct drying or steam stripping to the solution. In this case, as the polymerization terminator, those mentioned above can be used.

When the hydrogenated block copolymer composition is recovered as a slurry by steam stripping or the like, dehydration is performed using any dehydrator such as an extruder type squeezer to form a crumb-like hydrogenated block copolymer composition. It is preferable to collect the composition and further dry the obtained crumb using any dryer such as a band dryer or an expansion extrusion dryer. Further, the hydrogenated block copolymer composition obtained in this manner may be processed into a pellet shape or the like according to a conventional method before being used.

The solid (pellet-like, crumb-like, etc.) hydrogenated block copolymer composition obtained in this manner can be produced using, for example, a hopper dryer, a hot air circulation type shelf dryer, a shelf-type vacuum dryer, a stirring type vacuum dryer, etc. It is preferable to use a dryer such as a dryer to reduce the amount of water contained in the solid hydrogenated block copolymer composition before use. The drying conditions at this time are not particularly limited as long as the desired moisture content can be achieved, and may be set depending on the moisture content to be reduced and the type of dryer, but usually the drying temperature is 40 to 90%. ℃, and the drying time is set in the range of 1 to 24 hours.

According to the above-described method for producing a hydrogenated block copolymer composition, hydrogenated block copolymer A and hydrogenated block copolymer B can be continuously obtained in the same reaction vessel. The desired hydrogenated block copolymer composition can be obtained with superior productivity compared to the case where hydrogenated block copolymers are individually produced and mixed.

In addition, when producing the hydrogenated block copolymer composition of the present invention, in addition to the above-mentioned preferred production method (production method comprising steps (1) to (7)), the following (1a) to A method for producing a hydrogenated block copolymer composition having the step (6a) is also preferably used.
(1a): Step (2a) of obtaining a solution containing an aromatic vinyl polymer having an active end by polymerizing an aromatic vinyl monomer using a polymerization initiator in a solvent: (1a) above By adding a conjugated diene monomer to a solution containing an aromatic vinyl polymer having an active end obtained in the step and polymerizing the conjugated diene monomer, an aromatic vinyl conjugate having an active end is obtained. Step (3a) of obtaining a solution containing a diene block copolymer: Into the solution containing the aromatic vinyl-conjugated diene block copolymer having an active end obtained in step (2a) above, A difunctional coupling agent is added in an amount such that the total amount of functional groups is less than 1 molar equivalent, and a part of the aromatic vinyl-conjugated diene block copolymer having an active end is coupled to form a block copolymer. Step (4a) of obtaining a solution containing the polymer B': Adding an aromatic vinyl monomer to the solution containing the block copolymer B' obtained in the step (3a) above to obtain a solution containing the aromatic vinyl monomer. Step (5a) of obtaining a solution containing block copolymer B' and block copolymer A' by polymerizing vinyl monomers: Block copolymer B' obtained in the step (4a) above and Step (6a) of obtaining a solution containing hydrogenated block copolymer B and hydrogenated block copolymer A by performing a hydrogenation reaction on the solution containing block copolymer A': (5a) above A step of recovering a hydrogenated block copolymer composition from a solution containing hydrogenated block copolymer B and hydrogenated block copolymer A obtained in step

<Step (1a), Step (2a)>
Step (1a) and step (2a) are similar to step (1) and step (2) described above, and similar conditions can be adopted.

<Step (3a)>
In step (3a), a total amount of functional groups of 1 molar equivalent relative to the active end is added to the solution containing the aromatic vinyl-conjugated diene block copolymer having an active end obtained in step (2a) above. A difunctional coupling agent is added in an amount less than obtain.

The block copolymer B' obtained in step (3a) is a block copolymer before hydrogenation to obtain hydrogenated block copolymer B.

The bifunctional coupling agent is not particularly limited as long as it has two functional groups that react with the active end, but examples include difunctional halogenated agents such as dichlorosilane, monomethyldichlorosilane, and dimethyldichlorosilane. Silane; difunctional halogenated alkanes such as dichloroethane, dibromoethane, methylene chloride, dibromomethane; dichlorotin, monomethyldichlorotin, dimethyldichlorotin, monoethyldichlorotin, diethyldichlorotin, monobutyldichlorotin, dibutyldichlorotin, etc. Difunctional tin halide;

The amount of the bifunctional coupling agent to be used may be determined depending on the ratio of hydrogenated block copolymer A and hydrogenated block copolymer B constituting the hydrogenated block copolymer composition.

As described above, according to step (3a), the total amount of functional groups is less than 1 molar equivalent with respect to the active end in the solution containing the aromatic vinyl-conjugated diene block copolymer having an active end. By adding a bifunctional coupling agent in an amount that is equal to This becomes a block copolymer B' before hydrogenation to constitute B. The remaining part of the aromatic vinyl-conjugated diene block copolymer with active ends that did not react with the bifunctional coupling agent remains unreacted and remains in the solution with the active ends maintained. It will remain.

<Step (4a)>
Next, in step (4a), an aromatic vinyl monomer is added to the solution containing the block copolymer B' obtained in the above step (3a), and the aromatic vinyl monomer is dissolved. By polymerizing, a solution containing block copolymer B' and block copolymer A' is obtained.

According to step (4a), when the aromatic vinyl monomer is added to the solution obtained in the above step (3a), the aromatic vinyl monomer having an active end that did not react with the bifunctional coupling agent remains. An aromatic vinyl monomer is polymerized from the active end of the conjugated diene block copolymer to form an aromatic vinyl polymer chain, thereby obtaining a block copolymer A'. Note that the block copolymer A' is a block copolymer before hydrogenation to obtain the hydrogenated block copolymer A.

At this time, in step (4a), the aromatic vinyl polymer chain formed is an aromatic vinyl polymer chain having a relatively large weight average molecular weight of hydrogenated block copolymer A constituting the hydrogenated block copolymer composition. This constitutes a vinyl polymer block ^Ar2a . Therefore, each polymerization condition including the amount of aromatic vinyl monomer in step (4a) may be determined depending on the target weight average molecular weight of such aromatic vinyl polymer block ^Ar2a ( For example, the polymerization conditions may be determined within the range described in step (1) above.)

<Step (5a), Step (6a)>
Then, using the solution containing block copolymer B' and block copolymer A' obtained in step (4a), through the operations in step (5a) and step (6a) described above, the present invention is carried out. A hydrogenated block copolymer composition for use can be obtained. Note that the above-described step (5a) and step (6a) are the same as the above-mentioned step (6) and step (7), and the same conditions can be adopted.

The adhesive for a surface protection material of the present invention contains a tackifier resin in addition to the above-mentioned hydrogenated block copolymer composition. The adhesive for a surface protection material of the present invention can form a surface protection material exhibiting excellent adhesiveness by containing a tackifying resin. The type of tackifying resin contained in the adhesive for surface protection materials of the present invention is not particularly limited, and examples thereof include rosin; modified rosin such as disproportionated rosin and dimerized rosin; glycol, glycerin, pentaerythritol, etc. Esterified products of polyhydric alcohols and rosins or modified rosins; terpene resins; aliphatic, aromatic, alicyclic or aliphatic-aromatic copolymerized hydrocarbon resins such as petroleum resins; hydrides; phenolic resins; coumaron-indene resins, etc. can be used as tackifying resins, especially aliphatic, aromatic, alicyclic, or aliphatic-aromatic copolymerized hydrocarbons. Resins or hydrides thereof are preferably used, and in particular, alicyclic hydrocarbon resins or hydrides of alicyclic hydrocarbon resins are particularly preferably used. Note that the tackifying resin may be used alone or in combination of two or more.

The softening point of the tackifying resin contained in the adhesive for surface protection materials of the present invention is not particularly limited, but is preferably 10 to 160°C, more preferably 20 to 150°C. By using a tackifier resin having a softening point within this range, the surface protection material obtained will have better adhesiveness.

The content of the tackifier resin in the pressure-sensitive adhesive for surface protection materials of the present invention is not particularly limited, but is preferably 1 to 100 parts by weight, based on 100 parts by weight of the hydrogenated block copolymer composition. The amount is more preferably 90 parts by weight, and even more preferably 10 to 85 parts by weight. When the content of the tackifying resin is within this range, the resulting surface protective material has better suppression of increase in adhesive strength.

In addition to the hydrogenated block copolymer composition and the tackifier resin, an antioxidant can be added to the adhesive for surface protection material of the present invention, if necessary. The type is not particularly limited, and examples include pentaerythritol tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,6-di-t-butyl-p-cresol, di Hindered phenolic compounds such as -t-butyl-4-methylphenol; thiodicarboxylate esters such as dilaurylthiopropionate; phosphites such as tris(nonylphenyl)phosphite; can. The amount of the antioxidant used is not particularly limited, but is usually 10 parts by weight or less, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the hydrogenated block copolymer composition. In addition, one type of antioxidant may be used alone, or two or more types may be used in combination. Furthermore, there is no particular limitation on the timing of blending the antioxidant into the adhesive for surface protection materials. Alternatively, it may be added when mixing the hydrogenated block copolymer composition and the tackifying resin.

Other additives such as a softener, a heat stabilizer, an ultraviolet absorber, and a filler can be further added to the adhesive for surface protection material of the present invention.

To obtain the adhesive for surface protection materials of the present invention, the method of mixing the block copolymer composition with the tackifier resin and various additives is not particularly limited. For example, each component is dissolved in a solvent and mixed uniformly. After that, the solvent may be removed by heating or the like, or the components may be heated and melted and mixed using a kneader or the like.

The glass transition temperature of the adhesive for surface protection materials of the present invention is not particularly limited, but is preferably -50 to 30°C, more preferably -40 to 25°C. When the glass transition temperature is within this range, the adhesive for surface protection material has a particularly good balance between tackiness and spreadability. Note that the glass transition temperature of the adhesive for surface protection material can be easily adjusted according to a conventional method, for example, by adjusting the content of the tackifying resin.

The adhesive for surface protection materials of the present invention is used, for example, to form adhesive layers of various surface protection materials such as surface protection films, surface protection sheets, and surface protection tapes. By forming an adhesive layer with the adhesive for surface protection materials of the present invention, it has excellent adhesiveness and spreadability in a well-balanced manner, and furthermore, the increase in adhesive strength is well suppressed, and it also has excellent thermal stability. A surface protection material can be obtained. The base material and use of the surface protection material in which the adhesive for surface protection material of the present invention is used are not particularly limited, and it can be applied to various base materials and uses. In addition, aspects and uses of the surface protection material for which the adhesive for surface protection materials of the present invention is suitably used will be described in detail below as a description of the surface protection material of the present invention.

The surface protection material of the present invention is a surface protection material formed by laminating an adhesive layer made of the adhesive for surface protection materials of the present invention and a base material layer made of resin. The material constituting the base layer of the surface protection material of the present invention is not particularly limited as long as it is a resin, but from the viewpoint of ease of molding, thermoplastic resins are preferred, and olefin resins are particularly preferred. It is. The olefin resin used as the material for the base layer is not particularly limited, but includes, for example, polyethylene (low density, medium density, high density), polypropylene, polymethylpentene, polybutene, ethylene-propylene copolymer, propylene-butene copolymer, etc. Polymers can be used. Note that the resin constituting the base material layer may be used alone or in a mixture of two or more. In addition, additives such as antioxidants, colorants, foaming agents, flame retardants, lubricants, ultraviolet absorbers, light stabilizers, fillers, etc. may be added to the resin constituting the base layer as necessary. can do.

The thickness of the adhesive layer in the surface protection material of the present invention is not particularly limited, but is usually in the range of 1 to 50 μm, preferably in the range of 2 to 30 μm. The thickness of the base material layer is also not particularly limited, but is usually in the range of 10 to 50 μm, preferably in the range of 15 to 45 μm.

The surface protection material of the present invention may be a laminate consisting of only two layers, the above-mentioned adhesive layer and the base material layer, or may be a laminate consisting of only two layers, the above-mentioned adhesive layer and the base material layer, or may further be provided at any arbitrary position between these two layers or on either surface. A laminate of three or more layers including other layers may also be used. Further, each layer may be subjected to surface treatment such as corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, etc., as necessary.

The total thickness of the surface protection material of the present invention is not particularly limited, but is usually in the range of 11 to 100 μm, preferably in the range of 12 to 75 μm. Further, the surface protection material of the present invention can be in any form such as a surface protection film, a surface protection sheet, or a surface protection tape.

The method for manufacturing the surface protection material of the present invention is not particularly limited, and conventionally known methods for manufacturing surface protection materials can be applied. A preferred manufacturing method includes a method of forming a laminate by coextruding materials for each layer, such as the adhesive for surface protection material of the present invention and the resin constituting the base layer. .

After manufacturing, the surface protection material of the present invention can be stored in any form, for example, it can be wound into a so-called roll body. Since the surface protection material of the present invention uses the pressure-sensitive adhesive for surface protection materials of the present invention which has excellent spreadability, it can be easily rolled out from a roll and used.

The surface protection material of the present invention has an adhesive layer that protects the surface of various articles from damage caused by dirt/dust adhesion or contact with other objects during storage or transportation. It is used by being attached to an article so that it is in contact with the surface of the article. Specific examples of articles to be protected include, but are not limited to, metal plates, synthetic resin plates, decorative wooden boards, displays, optical films, and construction materials.

The surface protection material of the present invention has excellent adhesiveness and spreadability in a well-balanced manner by using the adhesive for surface protection materials of the present invention, so when it is applied to an article, unintended peeling may occur. It is tough and easily peels off from the article. In addition, since the surface protection material of the present invention is one in which the increase in adhesive strength is well suppressed by using the adhesive for surface protection materials of the present invention, even after being attached to an article for a long period of time, the surface protection material remains stable. It is easy to peel off from the surface. Furthermore, the surface protection material of the present invention has excellent thermal stability due to the use of the adhesive for surface protection materials of the present invention, so even if it is attached to an article for a long period of time under high temperature conditions, Unintended peeling is unlikely to occur.

The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Note that "parts" and "%" are based on weight unless otherwise specified.
The test methods performed in the present examples and comparative examples are as follows.

[Weight average molecular weight, molecular weight distribution]
A chart based on polystyrene equivalent molecular weight was obtained by high performance liquid chromatography using tetrahydrofuran as a carrier at a flow rate of 0.35 ml/min, and the determination was made based on the obtained chart. The device is HLC8320 manufactured by Tosoh Corporation, the column is a combination of three Shodex (registered trademark) KF-404HQ manufactured by Showa Denko Co., Ltd. (column temperature 40°C), and the detector is a differential refractometer and an ultraviolet detector. Calibration was performed on 12 points of standard polystyrene (500 to 3 million) manufactured by Polymer Laboratory.

[Weight ratio of each block copolymer in the (hydrogenated) block copolymer composition]
It was determined from the area ratio of the peaks corresponding to each block copolymer in the chart obtained by the above-mentioned high performance liquid chromatography.

[Weight average molecular weight of styrene polymer block of (hydrogenated) block copolymer]
Rubber Chem. Technol. , 45, 1295 (1972), by reacting the (hydrogenated) block copolymer with ozone and reducing it with lithium aluminum hydride. The block was disassembled.
Specifically, the following steps were performed. That is, 300 mg of the sample was dissolved in a reaction vessel containing 100 ml of dichloromethane treated with molecular sieve. The reaction vessel was placed in a cooling tank and cooled to −25° C., and then ozone generated by an ozone generator was introduced while oxygen was flowing into the reaction vessel at a flow rate of 170 ml/min. After 30 minutes from the start of the reaction, completion of the reaction was confirmed by introducing the gas flowing out from the reaction vessel into the aqueous potassium iodide solution. Next, 50 ml of diethyl ether and 470 mg of lithium aluminum hydride were placed in another reaction vessel purged with nitrogen, and while cooling the reaction vessel with ice water, the solution reacted with ozone was slowly dropped into the reaction vessel. Then, the reaction container was placed in a water bath, and the temperature was gradually raised to reflux at 40° C. for 30 minutes. Thereafter, while stirring the solution, dilute hydrochloric acid was added dropwise little by little into the reaction vessel, and the dropwise addition was continued until almost no hydrogen generation was observed. After this reaction, the solid product formed in the solution was filtered off, and the solid product was extracted with 100 ml of diethyl ether for 10 minutes. This extract and the filtrate obtained by filtration were combined, and the solvent was distilled off to obtain a solid sample. The weight average molecular weight of the sample thus obtained was measured according to the method for measuring weight average molecular weight described above, and the value was taken as the weight average molecular weight of the styrene polymer block.

[Weight average molecular weight of (hydrogenated) isoprene polymer block of (hydrogenated) block copolymer]
The weight average molecular weight of the corresponding styrene polymer block is subtracted from the weight average molecular weight of the (hydrogenated) block copolymer determined as above, and based on that calculated value, the weight average molecular weight of the (hydrogenated) isoprene is determined. The weight average molecular weight of the combined block was determined.

[Styrene unit content of (hydrogenated) block copolymer]
It was determined based on the detection intensity ratio between the differential refractometer and the ultraviolet detector in the above-mentioned high performance liquid chromatography measurement. Note that copolymers having different styrene unit contents were prepared in advance, and a calibration curve was created using them.

[Styrene unit content of the entire (hydrogenated) block copolymer composition]
It was determined based on proton NMR measurements.

[Vinyl bond content of (hydrogenated) isoprene polymer block]
It was determined based on proton NMR measurements.

[Olefin hydrogenation rate (mol%) of (hydrogenated) block copolymer composition]
By ^1H -NMR spectrum measurement, the olefin content was determined for each of the block copolymer composition before hydrogenation and the hydrogenated block copolymer composition after hydrogenation, and based on the difference in the olefin content before and after hydrogenation. The olefin hydrogenation rate (mol%) was calculated.
In ^{the 1} H-NMR spectrum measurement, deuterated chloroform was used as a solvent, and JMN-AL series AL400 (manufactured by JEOL) was used as an NMR measuring device.
In addition, in the present Examples and Comparative Examples, the block copolymer composition before hydrogenation and the hydrogenated block copolymer composition after hydrogenation both contained monomer units derived from olefins. Since it contained only isoprene units, upon measurement, the hydrogenation rate of isoprene was determined and this was taken as the olefin hydrogenation rate.

[Iodine value of (hydrogenated) block copolymer composition]
Measured in accordance with JIS K0070.

[Melt index of (hydrogenated) block copolymer composition]
Measured in accordance with ASTM D-1238 (G conditions, 200°C, 5 kg).

[Viscosity retention of (hydrogenated) block copolymer composition]
The crumb-like (hydrogenated) block copolymer composition was fed into a single-screw extruder equipped with an underwater hot-cut device at the tip of the extruder, and a cylindrical material with an average diameter of 5 mm and an average length of about 5 mm was produced. It was made into pellets. This pelletized (hydrogenated) block copolymer composition was placed in a hopper dryer heated to 60°C and dried for 10 hours while circulating dry air at 60°C.
Next, the dried (hydrogenated) block copolymer composition in the form of pellets obtained as described above is heated and melted at 200° C. using a twin screw extruder equipped with a T-die and extruded. As a result, it was formed into a film having a thickness of 0.2 mm.
Composition processing speed: 15kg/hr
Film take-up speed: 10m/min
Extruder temperature: Inlet 200℃, T-die 220℃
Screw: Full flight Extruder L/D: 42
T-die: width 300mm, lip 1mm
The obtained film was subjected to a heat deterioration test (170°C x 60 minutes; in the presence of air), and the melt viscosity was measured before and after the heat deterioration test, and the viscosity retention was calculated using the following formula. The rate was calculated. It can be judged that the higher the viscosity retention rate, the better the stability of the (hydrogenated) block copolymer composition.
Viscosity retention rate (%) = (melt viscosity after thermal deterioration test/melt viscosity before thermal deterioration test) x 100
The melt viscosity was measured using a flow tester CFT-500C (manufactured by Shimadzu Corporation) under the conditions of a temperature of 180° C., a load of 100 kgf/cm ² , and a die shape of 1 mmφ×10 mm.

[Softening point of tackifier resin]
It was measured by the ring and ball method according to JIS K 2531.

[Initial peel force (low speed peel)]
The surface protection material was attached to a polypropylene plate by pressing at a speed of 300 mm/min at 23° C. using a 2 kg rubber roller, and the sample was measured 30 minutes after attachment. For this measurement sample, the peel adhesion strength (N/m) at 23°C was measured using a ChemInstruments "PA-1000" measuring device according to PSTC-1 (180° peel adhesion test by the United States Adhesive Tape Committee). -180'' and the peeling speed was 0.3 m/min to evaluate the peeling force. The larger this value is, the better the adhesiveness is.

[Initial peeling force (high speed peeling)]
The surface protection material was attached to a polypropylene plate by pressing at a speed of 300 mm/min at 23° C. using a 2 kg rubber roller, and the sample was measured 30 minutes after attachment. For this measurement sample, the peel adhesion strength (N/m) at 23°C was measured using a high-speed peel tester manufactured by Tester Sangyo Co., Ltd. The peeling force was evaluated by measuring using a testing machine "TE-701-S" at a peeling speed of 15 m/min. The smaller this value is, the better the expandability is.

[Room temperature aging peeling force]
The surface protection material was attached to the polypropylene plate by pressing at a speed of 300 mm/min at 23 °C using a 2 kg rubber roller, and after pasting, it was left to stand in a gear oven at 20 °C for 14 days. After that, the sample was allowed to cool and was used as a measurement sample. For this measurement sample, the peel adhesion strength (N/m) at 23°C was measured using a ChemInstruments "PA-1000" measuring device according to PSTC-1 (180° peel adhesion test by the United States Adhesive Tape Committee). -180'' and the peeling speed was 0.3 m/min to evaluate the peeling force. It can be judged that the smaller the difference between this value and the value of the initial peeling force (low-speed peeling), the better the increase in adhesive force is suppressed.

[High temperature aging peeling force]
The surface protection material was pasted on the polypropylene plate by pressing at a speed of 300 mm/min using a 2 kg rubber roller at 23°C, and left undisturbed in a gear oven at 80°C for 14 days after pasting. After that, the sample was allowed to cool and was used as a measurement sample. For this measurement sample, the peel adhesion strength (N/m) at 23°C was measured using a ChemInstruments "PA-1000" measuring device according to PSTC-1 (180° peel adhesion test by the United States Adhesive Tape Committee). -180'' and the peeling speed was 0.3 m/min to evaluate the peeling force. It can be judged that the smaller the difference between this value and the value of the peeling force over time at room temperature is, the more excellent the thermal stability is.

[Manufacture example 1]
(1) Production of block copolymer composition before hydrogenation 56.6 kg of cyclohexane, 505 mmol of dibutyl ether, and 1.22 kg of styrene were added to a pressure reactor. While stirring the entire volume at 40°C, 270.6 mmol of n-butyllithium (1.6M solution) was added. After the addition was completed, the temperature was raised to 50°C and a polymerization reaction was carried out for 1 hour (first stage of polymerization). The polymerization conversion rate of styrene at this time was 100% by weight.

Subsequently, 6.49 kg of isoprene was continuously added to the reactor over 1 hour while controlling the temperature to maintain a temperature of 50-60°C. After the addition of isoprene was completed, the polymerization reaction was further carried out for 1 hour (second stage of polymerization). The polymerization conversion rate of isoprene at this time was 100%.

Next, 1.22 kg of styrene was continuously added over 1 hour while controlling the temperature to maintain the temperature at 50 to 60°C. After the addition of styrene was completed, the polymerization reaction was further carried out for 1 hour to obtain a solution containing a styrene-isoprene-styrene triblock copolymer having an active terminal (third stage of polymerization). The polymerization conversion rate of styrene at this time was 100%.

Next, 195 mmol of methanol was added as a polymerization terminator and mixed to deactivate some of the active ends of the styrene-isoprene-styrene triblock copolymer having active ends, resulting in hydrogenation. A solution containing a styrene-isoprene-styrene triblock copolymer to be used as block copolymer B' to obtain block copolymer B was obtained.

Thereafter, 1.06 kg of styrene was continuously added over 1 hour while controlling the temperature to maintain the temperature at 50 to 60°C. After completing the addition of styrene, the polymerization reaction is further carried out for 1 hour to obtain a hydrogenated block copolymer A. A styrene-isoprene-styrene triblock copolymer having an active end becomes block copolymer A'. A solution containing (4th stage of polymerization) was obtained. The polymerization conversion rate of styrene at this time was 100%.

Finally, 345 mmol of methanol is added as a polymerization terminator and mixed to deactivate all the active ends of the styrene-isoprene-styrene triblock copolymer having active ends, thereby completing the polymerization reaction. As a result, a solution containing the block copolymer composition before hydrogenation was obtained.
The amounts of each reagent used in the reaction are summarized in Table 1.

(2) Hydrogenation reaction of block copolymer composition before hydrogenation By performing a hydrogenation reaction on the solution containing the block copolymer composition before hydrogenation obtained above, the hydrogenated block A solution containing the copolymer composition was obtained. In the hydrogenation reaction, a Ni(AcAc) ₂ -TIBAL catalyst was added as a hydrogenation catalyst to a solution containing the block copolymer composition before hydrogenation obtained above. The reaction was carried out under conditions of hydrogen pressure of 3 MPa, reaction temperature of 80° C., and reaction time of 3 hours.

A part of the solution containing the hydrogenated block copolymer composition obtained in this way was taken out, and the weight average molecular weight and molecular weight distribution of the hydrogenated block copolymer composition (whole) were measured. Weight ratio of block copolymers, weight average molecular weight of styrene polymer block of each hydrogenated block copolymer, weight average molecular weight of hydrogenated isoprene polymer block of each hydrogenated block copolymer, weight average molecular weight of hydrogenated isoprene polymer block of each hydrogenated block copolymer, The styrene unit content of the aggregate, the styrene unit content of the hydrogenated block copolymer composition (total), the vinyl bond content of the hydrogenated isoprene polymer block of each hydrogenated block copolymer, and the hydrogenated block copolymer composition. The olefin hydrogenation rate of the combined composition (total) was determined. These values are summarized in Table 2.

(3) Recovery of hydrogenated block copolymer composition 2,6-di-t-butyl was added as an antioxidant to 100 parts of the solution containing the hydrogenated block copolymer composition obtained as described above. 0.3 part of -p-cresol was added and mixed, and the mixed solution was dropped little by little into warm water heated to 85 to 95°C to evaporate the solvent to obtain a precipitate. The resulting precipitate was pulverized and dried with hot air at 85°C to recover a crumb-like hydrogenated block copolymer composition. The iodine value, melt index, and viscosity retention of the obtained hydrogenated block copolymer composition were measured. These results are summarized in Table 2.

[Production example 2]
A hydrogenated block copolymer composition was obtained in the same manner as in Production Example 1, except that the reaction time in the hydrogenation reaction was changed from 3 hours to 1 hour, and measurements were performed in the same manner. The results are summarized in Table 2.

[Manufacture example 3]
Except that the amounts of styrene, dibutyl ether, n-butyl lithium, isoprene, and methanol were changed as shown in Table 1, and the reaction time in the hydrogenation reaction was changed from 3 hours to 15 minutes. A hydrogenated block copolymer composition was obtained in the same manner as in Example 1, and measurements were performed in the same manner. The results are summarized in Table 2.

[Manufacture example 4]
Except that the amounts of styrene, dibutyl ether, n-butyl lithium, isoprene, and methanol were changed as shown in Table 1, and the reaction time in the hydrogenation reaction was changed from 3 hours to 2 hours. A hydrogenated block copolymer composition was obtained in the same manner as in Example 1, and measurements were performed in the same manner. The results are summarized in Table 2.

[Manufacture example 5]
(1) Production of block copolymer composition before hydrogenation 56.6 kg of cyclohexane, 842 mmol of dibutyl ether, and 1.04 kg of styrene were added to a pressure reactor. While stirring the entire volume at 40°C, 451.5 mmol of n-butyllithium (1.6M solution) was added. After the addition was completed, the temperature was raised to 50°C and a polymerization reaction was carried out for 1 hour (first stage of polymerization). The polymerization conversion rate of styrene at this time was 100% by weight.

Subsequently, 7.99 kg of isoprene was continuously added to the reactor over 1 hour while controlling the temperature to maintain a temperature of 50-60°C. After the addition of isoprene was completed, the polymerization reaction was further carried out for 1 hour to obtain a solution containing a styrene-isoprene diblock copolymer having an active terminal (second stage of polymerization). The polymerization conversion rate of isoprene at this time was 100%.

Next, 154 mmol of dimethyldichlorosilane was added as a bifunctional coupling agent and mixed to couple a portion of the styrene-isoprene diblock copolymer having an active end, resulting in hydrogenation. A solution containing a styrene-isoprene-styrene triblock copolymer to be used as block copolymer B' to obtain block copolymer B was obtained.

Thereafter, 0.96 kg of styrene was continuously added over 1 hour while controlling the temperature to maintain the temperature at 50 to 60°C. After completing the addition of styrene, the polymerization reaction is further carried out for 1 hour to obtain hydrogenated block copolymer A, which is a styrene-isoprene-styrene triblock copolymer with active terminals, which becomes block copolymer A'. A solution containing (3rd stage of polymerization) was obtained. The polymerization conversion rate of styrene at this time was 100%.

Finally, 595 mmol of methanol is added as a polymerization terminator and mixed to deactivate all the active ends of the styrene-isoprene-styrene triblock copolymer having active ends, thereby completing the polymerization reaction. As a result, a solution containing the block copolymer composition before hydrogenation was obtained.
The amounts of each reagent used in the reaction are summarized in Table 1.

(2) Hydrogenation reaction of block copolymer composition before hydrogenation By performing a hydrogenation reaction on the solution containing the block copolymer composition before hydrogenation obtained above, the hydrogenated block A solution containing the copolymer composition was obtained. The hydrogenation reaction was carried out under the same conditions as in Production Example 1. Then, a portion of the solution containing the obtained hydrogenated block copolymer composition was taken out, and measurements were performed in the same manner as in Production Example 1. The results are summarized in Table 2.

(3) Recovery of hydrogenated block copolymer composition Using a solution containing the obtained hydrogenated block copolymer composition, recovery was carried out in the same manner as in Production Example 1, and then measurement was carried out in the same manner. Ta. The results are summarized in Table 2.

[Production example 6]
(1) Production of block copolymer composition before hydrogenation 56.6 kg of cyclohexane, 517 mmol of dibutyl ether, and 1.75 kg of styrene were added to a pressure reactor. While stirring the entire volume at 40°C, 284.2 mmol of n-butyllithium (1.6M solution) was added. After the addition was completed, the temperature was raised to 50°C and a polymerization reaction was carried out for 1 hour (first stage of polymerization). The polymerization conversion rate of styrene at this time was 100% by weight.

Subsequently, 6.49 kg of isoprene was continuously added to the reactor over 1 hour while controlling the temperature to maintain a temperature of 50-60°C. After the addition of isoprene was completed, the polymerization reaction was further carried out for 1 hour (second stage of polymerization). The polymerization conversion rate of isoprene at this time was 100%.

Next, 1.75 kg of styrene was continuously added over 1 hour while controlling the temperature to maintain the temperature at 50 to 60°C. After the addition of styrene was completed, the polymerization reaction was further carried out for 1 hour to obtain a solution containing a styrene-isoprene-styrene triblock copolymer having an active terminal (third stage of polymerization). The polymerization conversion rate of styrene at this time was 100%.

Finally, 568.4 mmol of methanol is added as a polymerization terminator and mixed to deactivate all the active terminals of the styrene-isoprene-styrene triblock copolymer having active terminals and stop the polymerization reaction. This resulted in a solution containing the block copolymer composition before hydrogenation.
The amounts of each reagent used in the reaction are summarized in Table 1.

(2) Hydrogenation reaction of block copolymer composition before hydrogenation By performing a hydrogenation reaction on the solution containing the block copolymer composition before hydrogenation obtained above, the hydrogenated block A solution containing the copolymer composition was obtained. The hydrogenation reaction was carried out under the same conditions as in Production Example 1. Then, a portion of the solution containing the obtained hydrogenated block copolymer composition was taken out, and measurements were performed in the same manner as in Production Example 1. The results are summarized in Table 2.

(3) Recovery of hydrogenated block copolymer composition Using a solution containing the obtained hydrogenated block copolymer composition, recovery was carried out in the same manner as in Production Example 1, and then measurement was carried out in the same manner. Ta. The results are summarized in Table 2.

[Manufacture example 7]
The same procedure as in Production Example 1 was carried out except that the amounts of styrene, dibutyl ether, n-butyl lithium, isoprene, and methanol were changed as shown in Table 1, and the hydrogenation reaction was not performed. A hydrogenated block copolymer composition was produced, and measurements were conducted in the same manner using the obtained unhydrogenated block copolymer composition. The results are summarized in Table 2.

[Production example 8]
The same procedure as in Production Example 6 was carried out except that the amounts of styrene, dibutyl ether, n-butyl lithium, isoprene, and methanol were changed as shown in Table 1, and the hydrogenation reaction was not performed. A hydrogenated block copolymer composition was produced, and measurements were conducted in the same manner using the obtained unhydrogenated block copolymer composition. The results are summarized in Table 2.

[Example 1]
100 parts of the hydrogenated block copolymer composition obtained in Production Example 1 was charged into a stirring vane type kneader, and an alicyclic hydrocarbon resin having a softening point of 125° C. was added as a tackifying resin. 50 parts of "Escolettes 5320" manufactured by ExxonMobil Chemical Company and "Irganox 1010" manufactured by BASF, which is pentaerythritol tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] as an antioxidant. After adding 1 part of the mixture and purging the system with nitrogen gas, the adhesive was prepared by kneading at 160 to 180° C. for 1 hour. Next, coextrusion molding is performed using the T-die method using the obtained adhesive and "Nipolon-L F14" manufactured by Tosoh Corporation, which is a linear low-density polyethylene resin, to obtain a thickness of the adhesive. A surface protection material was obtained in which two layers were laminated: a 10 μm adhesive layer and a 25 μm thick base material layer made of linear low-density polyethylene resin. Regarding this surface protection material, initial peel force (low-speed peel), initial peel force (high-speed peel), peel force over time at room temperature, and peel force over time at high temperature were measured. The results are summarized in Table 3.

[Examples 2 to 5, Comparative Examples 1 to 3]
A pressure-sensitive adhesive was prepared in the same manner as in Example 1, except that the type of hydrogenated block copolymer composition used and the amount of tackifier resin were changed as shown in Table 3, and a surface protection material was obtained. Then, the obtained surface protection material was evaluated in the same manner as in Example 1. The results are summarized in Table 3.

As shown in Table 3, the hydrogenated block copolymer A represented by the general formula (A) and the hydrogenated block copolymer B represented by the general formula (B) were mixed in A/B (weight ratio )=10/90 to 80/20, and the hydrogenation rate of olefin in the polymer component constituting the hydrogenated block copolymer composition is 10 to 100%. According to the adhesive for surface protection material containing the combined composition and the tackifier resin, the surface protection material obtained has excellent tackiness and spreadability in a well-balanced manner, and the increase in tackiness is well suppressed. Furthermore, it was also excellent in thermal stability.
On the other hand, when the hydrogenated block copolymer A represented by the general formula (A) is not contained, the surface protective material obtained has excellent thermal stability but has increased adhesive strength. (Comparative Example 1).
Further, when the hydrogenation rate of the olefin was less than 10%, the resulting surface protection material had poor thermal stability (Comparative Example 2).
Furthermore, when the hydrogenated block copolymer A represented by the general formula (A) is not contained and the hydrogenation rate of the olefin is less than 10%, the resulting surface protection material has poor spreadability. The adhesive strength was increased, and the thermal stability was also poor (Comparative Example 3).

Claims (6)

A hydrogenated block copolymer composition having a hydrogenated block copolymer A represented by the following general formula (A) and a hydrogenated block copolymer B represented by the following general formula (B), and a tackifying resin An adhesive for a surface protection material, comprising:
In the hydrogenated block copolymer composition, the weight ratio (A/B) of the hydrogenated block copolymer A and the hydrogenated block copolymer B is 10/90 to 80/20,
An adhesive for a surface protection material, wherein the hydrogenation rate of olefin in the polymer component constituting the hydrogenated block copolymer composition is 10 to 100%.
Ar1 ^a -HD ^a -Ar2 ^a (A)
Ar1 ^b -HD ^b -Ar2 ^b (B)
(In the general formulas (A) and (B) above, Ar1 ^a , Ar2 ^a , Ar1 ^b , and Ar2 ^b are aromatic vinyl polymer blocks, and HD ^a and HD ^b are conjugated diene polymer blocks. It is a hydrogenated polymer block, and the weight average molecular weights of Ar1 ^a , Ar1 ^b , and Ar2 ^b are each in the range of 2,000 to 40,000, and the weight average molecular weight of Ar2 ^a is in the range of 5,000 to 250. ,000, and the weight average molecular weights of HD ^a and HD ^b are each in the range of 10,000 to 300,000, and the weight average molecular weight of Ar2 ^a with respect to the weight average molecular weight (Mw (Ar1 ^a )) of Ar1 ^a is The ratio (Mw( ^{Ar2 a )} /Mw(Ar1 ^{a )) of the weight average molecular weight (Mw(Ar2 a} )) is 2.6 to 66, and the weight average molecular weight (Mw(Ar1 ^b )) of Ar1 ^b is The ratio of the weight average molecular weight (Mw(Ar2 b ⁾ ) of Ar2 ^b (Mw(Ar2 ^b )/Mw(Ar1 ^b )) is 0.95 to 1.05 .) The pressure-sensitive adhesive for surface protection materials according to claim 1, wherein the proportion of aromatic vinyl monomer units in the total repeating units of the polymer component of the hydrogenated block copolymer composition is 20 to 70% by weight. . The hydrogenated block copolymer composition has a weight average molecular weight of H D ^a and HD ^b in the general formula (A) and general formula (B), respectively, in the range of 15,000 to 300,000. Item 2. The adhesive for surface protection materials according to item 1 or 2. Claims 1 to 3, wherein HD ^a and HD ^b in the general formula (A) and general formula (B) of the hydrogenated block copolymer composition each have a vinyl bond content of 1 to 20 mol%. The adhesive for surface protection materials according to any one of the above. The adhesive for a surface protection material according to any one of claims 1 to 4, wherein the content of the tackifying resin is 1 to 100 parts by weight based on 100 parts by weight of the hydrogenated block copolymer composition. A surface protection material formed by laminating an adhesive layer made of the adhesive for surface protection material according to any one of claims 1 to 5 and a base material layer made of a resin.