JP2019085588A - Tacky adhesive composition - Google Patents

Abstract

To provide a tacky adhesive composition containing an acrylic block copolymer which is excellent in heat-resistant holding force, tackiness and coating property.SOLUTION: A tacky adhesive composition contains 100 pts.mass of an acrylic triblock copolymer (I) which has two polymer blocks (A1) and (A2) composed of methacrylate units and one polymer block (B) composed of an acrylate unit, has (A1)-(B)-(A2) block structure, has a weight average molecular weight (Mw) of 300,000 or more and 450,000 or less, and has the total content of the polymer blocks (A1) and (A2) of 35 mass% or less, and 1 to 190 pts.mass of a tackifier resin (ii).SELECTED DRAWING: None

Description

  The present invention relates to a pressure-sensitive adhesive composition containing an acrylic block copolymer suitable for a pressure-sensitive adhesive and the like.

  It is conventionally known that a composition containing an acrylic block copolymer or an acrylic block copolymer is used for a pressure-sensitive adhesive.

  For example, a methacrylic acid alkyl ester polymer having a glass transition temperature of 110 ° C. or more and a syndiotacticity of 70% or more at both ends of a (meth) acrylic acid alkyl ester polymer block having a glass transition temperature of 30 ° C. or less There is known a block copolymer composition containing a triblock copolymer having a block bonded thereto and a (meth) acrylic acid alkyl ester-based diblock copolymer, and a pressure-sensitive adhesive comprising the composition (Patent Document 1) reference). Also known is an adhesive composition comprising a specific diblock copolymer comprising a methacrylic acid alkyl ester polymer block and an acrylic acid alkyl ester polymer block and a (meth) acrylic acid ester triblock copolymer. (See Patent Document 2). Furthermore, a pressure-sensitive adhesive composition containing a triblock copolymer and a diblock copolymer consisting of a specific methacrylic acid alkyl ester polymer block and an acrylic acid alkyl ester polymer block is known (Patent Document 3) reference).

Japanese Patent Application Publication No. 11-233072 JP 2004-2736 A JP 2005-307063 A

  The molecular specifications, tackifier resins and plasticizers of block copolymers specifically studied in the pressure-sensitive adhesive and pressure-sensitive adhesive composition described in the above-mentioned patent documents are limited, and the heat resistance, tackiness and coating are limited. There is still room for improvement in workability. An object of the present invention is to provide a pressure-sensitive adhesive composition containing an acrylic block copolymer excellent in heat resistance, tackiness and coatability.

  As a result of intensive studies to achieve the above object, the present inventors have developed a pressure-sensitive adhesive composition containing a specific acrylic triblock copolymer and a tackifying resin in a specific composition ratio. Thus, it has been found that a pressure-sensitive adhesive composition containing an acrylic block copolymer excellent in heat resistance, tackiness and coatability can be obtained.

According to the invention, the object is:
[1] (i) having two polymer blocks (A1) and (A2) consisting of methacrylic acid ester units and one polymer block (B) consisting of acrylic acid ester units, (A1)-(B) )-(A2) block structure, weight average molecular weight (Mw) is 300,000 or more and 450,000 or less, and total content of polymer blocks (A1) and (A2) is 35% by mass or less A pressure-sensitive adhesive composition containing 100 parts by mass of an acrylic triblock copolymer (I), and (ii) 1 to 190 parts by mass of a tackifying resin;
[2] (i) 100 parts by mass of the acrylic triblock copolymer (I),
(Ii) 1 to 190 parts by mass of a tackifying resin, and (iii) 80 parts by mass or less of a plasticizer, the adhesive composition of [1];
[3] It has one polymer block (C) consisting of methacrylic acid ester units and one polymer block (D) consisting of acrylic acid ester units, and has a weight average molecular weight (Mw) of 10,000 to 120, And further containing an acrylic diblock copolymer (II) having a content of the polymer block (C) of 25% by mass or less.
Adhesive composition according to [1] or [2];
Is achieved by providing

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive composition containing the acrylic block copolymer excellent in heat-resistant holding power, tackiness, and coating property is obtained.

  Hereinafter, the present invention will be described in detail. In the present specification, “(meth) acrylic acid ester” is a generic term for “methacrylic acid ester” and “acrylic acid ester”, and “(meth) acrylic” means “methacrylic” and “acrylic”. It is a generic term.

(Acrylic triblock copolymer (I))
The acrylic triblock copolymer (I) contained in the adhesive composition of the present invention is composed of two polymer blocks (A1) and (A2) consisting of methacrylic acid ester units and 1 acrylic acid ester unit Having two polymer blocks (B), having a (A1)-(B)-(A2) block structure, and having a weight average molecular weight (Mw) of 300,000 to 450,000, a polymer block The total content of (A1) and (A2) is 35% by mass or less.

(Polymer block (A1) and (A2))
The acrylic triblock copolymer (I) has two polymer blocks (A1) and (A2) consisting of methacrylic acid ester units.

  Examples of the methacrylic acid ester to be a constituent unit of the polymer blocks (A1) and (A2) include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, and methacrylic acid. Isobutyl, sec-butyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, lauryl methacrylate, tridecyl methacrylate, stearyl methacrylate, methacrylic acid Methacrylates having no functional group such as isobornyl, phenyl methacrylate and benzyl methacrylate; methoxyethyl methacrylate, ethoxyethyl methacrylate, diethyl methacrylate Ethyl, 2-hydroxyethyl methacrylate, 2-aminoethyl methacrylate, glycidyl methacrylate, and methacrylic acid esters having a functional group such as tetrahydrofurfuryl methacrylate.

  Among these, from the viewpoint of improving the heat resistance and durability of the obtained polymer, methacrylic acid esters having no functional group are preferable, and methyl methacrylate, ethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, Isobornyl methacrylate and phenyl methacrylate are more preferable, and methyl methacrylate is more preferable in that the phase separation between the polymer blocks (A1) and (A2) and the polymer block (B) becomes clearer and the cohesion becomes higher. . Polymer block (A1) and (A2) may be comprised from 1 type of these methacrylic acid ester, and may be comprised from 2 or more types. Moreover, although said acrylic triblock copolymer (I) has two of polymer block (A1) and (A2) as a polymer block which consists of a methacrylic acid ester unit, these polymer block (A1) and The methacrylic acid esters constituting (A2) may be the same or different. The proportion of methacrylic acid ester units contained in the polymer blocks (A1) and (A2) is preferably 60% by mass or more in each polymer block of the polymer blocks (A1) and (A2), 80 % By mass or more is more preferable, 90% by mass or more is more preferable, and 95% by mass or more is even more preferable. The proportion of methacrylic acid ester units contained in the polymer blocks (A1) and (A2) may be 100% by mass.

  In addition, the stereoregularity of the methacrylic acid ester unit contained in each polymer block (A1) and (A2) which consists of a methacrylic acid ester unit may mutually be same or different.

  In the acrylic triblock copolymer (I), the total content of the polymer blocks (A1) and (A2) is 35% by mass or less, preferably 25% by mass or less, and 20% by mass or less More preferably, it is 18 mass% or less, and may be 15 mass% or less. The total content of the polymer blocks (A1) and (A2) is preferably 2% by mass or more, more preferably 5% by mass or more, and still more preferably 8% by mass or more. It is further more preferable that it is mass% or more, and 12 mass% or more may be sufficient. When the total content of the polymer blocks (A1) and (A2) is within the above range, the cohesive strength is excellent when the acrylic triblock copolymer (I) is contained in the adhesive composition. While the tack and adhesion are further improved, the viscosity of the adhesive composition is not excessively increased, and the processability is secured. In addition, the adhesive composition increases the cohesion and strength due to the inclusion of the polymer blocks (A1) and (A2) in the acrylic triblock copolymer (I), and the heat resistant adhesive property and the heat resistant holding property Tend to be superior. The content of each of the polymer blocks (A1) and (A2) contained in the acrylic triblock copolymer (I) may be the same or different.

  The glass transition temperature (Tg) of each of the polymer blocks (A1) and (A2) is preferably 60 to 140 ° C., more preferably 70 to 130 ° C., and further preferably 80 to 130 ° C. preferable. When the Tg is in this range, the polymer blocks (A1) and (A2) act as physical pseudo-crosslinking points at the normal use temperature of the adhesive and the cohesion will be developed, and acrylic When the triblock copolymer (I) is contained in the adhesive composition, it is excellent in adhesion properties, durability, heat resistance and the like. In addition, Tg in this specification is the extrapolation start temperature of the curve obtained by DSC measurement.

  The Tgs of the polymer blocks (A1) and (A2) may be the same or different. Even when the Tg of each of the polymer blocks (A1) and (A2) is different, it is a preferred embodiment that the Tg of both polymer blocks is in the above range.

(Polymer block (B))
The acrylic triblock copolymer (I) has one polymer block (B) consisting of acrylic ester units.

  As an acrylic ester used as a structural unit of the said polymer block (B), methyl acrylate, ethyl acrylate, isopropyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, acrylic acid is mentioned, for example sec-Butyl, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, isobornyl acrylate, acrylate Acrylic esters having no functional group such as lauryl, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate and the like; methoxyethyl acrylate, ethoxyethyl acrylate, 2-hydro acrylate Shiechiru, 2-aminoethyl acrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate, diethylaminoethyl acrylate, such as phenoxyethyl acrylate, acrylic acid ester having a functional group.

Among them, from the viewpoint of transparency and flexibility in the adhesive composition, it is represented by the general formula CH ₂ CHCH—COOR ¹ (wherein, R ¹ represents an organic group having 1 to 10 carbon atoms) Acrylic acid ester is preferable, and from the viewpoint that the phase separation of the polymer blocks (A1) and (A2) and the polymer block (B) becomes clear and the adhesive composition develops high cohesion, methyl acrylate Ethyl acrylate, isopropyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate , 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, isobornyl acrylate , Cyclohexyl acrylate, phenyl acrylate, such as benzyl acrylate, acrylic acid esters having no functional group is more preferable. Furthermore, methyl acrylate and n-butyl acrylate are preferable in that the adhesive composition has appropriate adhesiveness at normal temperature and develops stable adhesion under a wide temperature range and a wide peeling rate condition. More preferred is at least one selected from 2-ethylhexyl acrylate, n-octyl acrylate and isooctyl acrylate, and particularly preferred is n-butyl acrylate.

  Polymer block (B) may be comprised from 1 type of these acrylic acid ester, and may be comprised from 2 or more types. 60 mass% or more is preferable, as for the ratio of the acrylic acid ester unit contained in a polymer block (B), 80 mass% or more is more preferable, 90 mass% or more is more preferable, 95 mass% or more is still more preferable. Moreover, 100 mass% may be sufficient as the ratio of the acrylic ester unit contained in a polymer block (B).

  In the acrylic triblock copolymer (I), the content of the polymer block (B) is preferably 65% by mass or more, more preferably 75% by mass or more, and 80% by mass or more Is more preferable, and 85% by mass or more is even more preferable. The content of the polymer block (B) is preferably 98% by mass or less, more preferably 95% by mass or less, still more preferably 92% by mass or less, and 90% by mass or less Is even more preferred. When the content of the polymer block (B) is in the above range, when the acrylic triblock copolymer (I) is used for the adhesive composition, it exhibits excellent cohesive force, and the tack or tack While the adhesion is further improved, the viscosity of the composition is not excessively increased and processability is ensured.

  The glass transition temperature (Tg) of the polymer block (B) is preferably -100 to 30 ° C, more preferably -80 to 10 ° C, and still more preferably -70 to 0 ° C. When the Tg is in this range, it can have excellent tack and adhesion when used in a pressure-sensitive adhesive composition.

  The polymer blocks (A1) and (A2) and the polymer block (B) may contain monomer components of each other as long as the effects of the present invention are not impaired. For example, it may have a tapered structure at the boundary between the polymer block (A1) or (A2) and the polymer block (B). In addition, the polymer block (A1) or (A2) and the polymer block (B) may not contain each other's monomer components.

  Further, the polymer blocks (A1) and (A2) and the polymer block (B) may contain other monomer units as needed. Such other monomers include, for example, vinyl monomers having a carboxyl group such as (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid and the like; (meth) acrylamides, (meth) acrylonitrile, Vinyl monomers having functional groups such as vinyl acetate, vinyl chloride and vinylidene chloride; aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene and m-methylstyrene; butadiene, isoprene and the like Conjugated diene-based monomers; olefin-based monomers such as ethylene, propylene, isobutene and octene; and lactone-based monomers such as ε-caprolactone and valerolactone. When each polymer block contains these other monomers, its content is preferably 20% by mass or less, more preferably 10% by mass, with respect to the total mass of the monomers constituting each polymer block. % Or less, more preferably 5% by mass or less.

  (A1)-(B)-(A2) block structure in which acrylic triblock copolymer (I) is bonded in the order of polymer block (A1), polymer block (B) and polymer block (A2) Have. By the acrylic triblock copolymer (I) having this structure, a pressure-sensitive adhesive composition excellent in adhesion, heat-resistant holding power and cohesion can be obtained.

  The weight average molecular weight (Mw) of the acrylic triblock copolymer (I) is 300,000 or more and 450,000 or less. From the viewpoint of cohesion and handleability at the time of production, it is preferably 310,000 or more and 430,000 or less, more preferably 320,000 or more and 420,000 or less, and 320,000 or more and 400,000 or less It is further preferred that If the Mw of the acrylic triblock copolymer (I) is less than 300,000, the heat resistance may be inferior. In addition, when Mw exceeds 450,000, there is a possibility that gel may be generated during the production, and the handleability at the time of production and the processability at the time of processing may be inferior.

  The molecular weight distribution (Mw / Mn) of the acrylic triblock copolymer (I) is preferably 1.0 to 1.5, and more preferably 1.0 to 1.4. The weight average molecular weight (Mw) and the number average molecular weight (Mn) in the present specification are the weight average molecular weight and the number average molecular weight in terms of standard polystyrene determined by gel permeation chromatography (GPC) measurement.

(Acrylic diblock copolymer (II))
The adhesive composition of the present invention further comprises one polymer block (C) consisting of methacrylic acid ester units and one polymer block (D) consisting of acrylic acid ester units, and has a weight average You may contain acrylic diblock copolymer (II) whose molecular weight (Mw) is 10,000-120,000 and whose content of a polymer block (C) is 25 mass% or less.

(Polymer block (C))
The acrylic diblock copolymer (II) preferably has one polymer block (C) composed of methacrylic acid ester units.

  Specific examples of the methacrylic acid ester to be a constituent unit of the polymer block (C) are a methacrylic acid ester to be a constituent unit of the polymer blocks (A1) and (A2) of the acrylic triblock copolymer (I) It is similar.

  Among these, from the viewpoint of improving the heat resistance and durability of the obtained polymer, methacrylic acid esters having no functional group are preferable, and methyl methacrylate, ethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, Isobornyl methacrylate and phenyl methacrylate are more preferable, and methyl methacrylate is more preferable in that the phase separation between the polymer block (C) and the polymer block (D) becomes clearer and the cohesion becomes higher. A polymer block (C) may be comprised from 1 type of these methacrylic acid ester, and may be comprised from 2 or more types. 60 mass% or more is preferable, as for the ratio of the methacrylic acid ester unit contained in a polymer block (C), 80 mass% or more is more preferable, 90 mass% or more is more preferable, 95 mass% or more is still more preferable. Moreover, the ratio of the methacrylic acid ester unit contained in a polymer block (C) may be 100 mass%.

  In the acrylic diblock copolymer (II), the content of the polymer block (C) is preferably 25% by mass or less, more preferably 20% by mass or less, and 10% by mass or less Is more preferred. Moreover, it is preferable that it is 2 mass% or more, and, as for content of a polymer block (C), it is more preferable that it is 4 mass% or more. When the content of the polymer block (C) is in the above range, when the acrylic diblock copolymer (II) is contained in the tacky-adhesive composition, the tack and the cohesion are not impaired. The processability tends to be further improved.

  The glass transition temperature (Tg) of the polymer block (C) is preferably 60 to 140 ° C., more preferably 70 to 130 ° C., and still more preferably 80 to 130 ° C. When the Tg is in this range, this polymer block (C) acts as a physical pseudo-crosslinking point at the normal use temperature of the adhesive to develop cohesion, and thus acrylic diblock copolymer When the combined (II) is contained in the adhesive composition, it is excellent in adhesive properties, durability, heat resistance and the like.

(Polymer block (D))
It is preferable that acrylic type diblock copolymer (II) has one polymer block (D) which consists of an acrylic acid ester unit.

  The specific example of the acrylic ester used as the structural unit of the said polymer block (D) is the same as that of the acrylic ester used as the structural unit of the polymer block (B) of acrylic type triblock copolymer (I).

Among them, from the viewpoint of transparency and flexibility in the adhesive composition, it is represented by the general formula CH ₂ CHCH—COOR ¹ (wherein, R ¹ represents an organic group having 1 to 10 carbon atoms) Acrylic acid ester is preferable, and methyl acrylate, ethyl acrylate, and the like from the viewpoint that the phase separation of the polymer block (C) and the polymer block (D) becomes clear and the adhesive composition develops high cohesion. Isopropyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-acrylate acrylate Ethyl hexyl, n-octyl acrylate, isooctyl acrylate, decyl acrylate, isobornyl acrylate, acrylic acrylate Hexyl, phenyl acrylate, such as benzyl acrylate, acrylic acid esters having no functional group is more preferable. Furthermore, methyl acrylate and n-butyl acrylate are preferable in that the adhesive composition has appropriate adhesiveness at normal temperature and develops stable adhesion under a wide temperature range and a wide peeling rate condition. More preferred is at least one selected from 2-ethylhexyl acrylate, n-octyl acrylate and isooctyl acrylate, and particularly preferred is n-butyl acrylate.

  A polymer block (D) may be comprised from 1 type of these acrylic acid ester, and may be comprised from 2 or more types. 60 mass% or more is preferable, as for the ratio of the acrylic acid ester unit contained in a polymer block (D), 80 mass% or more is more preferable, 90 mass% or more is more preferable, 95 mass% or more is still more preferable. Further, the proportion of the acrylic ester unit contained in the polymer block (D) may be 100% by mass.

  In the acrylic diblock copolymer (II), the content of the polymer block (D) is preferably 75% by mass or more, more preferably 80% by mass or more, and 90% by mass or more Is more preferred. The content of the polymer block (D) is preferably 98% by mass or less, more preferably 96% by mass or less. When the content of the polymer block (D) is in the above-mentioned range, when the acrylic diblock copolymer (II) is contained in the adhesive composition, the tack and the cohesion are not impaired. Processability is further improved.

  The glass transition temperature (Tg) of the polymer block (D) is preferably -100 to 30 ° C, more preferably -80 to 10 ° C, and still more preferably -70 to 0 ° C. When the Tg is in this range, the acrylic diblock copolymer (II) can have excellent tackiness and adhesion when used in the adhesive composition.

  The polymer block (C) and the polymer block (D) may contain monomer components of each other as long as the effects of the present invention are not impaired. For example, it may have a tapered structure at the boundary between the polymer block (C) and the polymer block (D). Moreover, the polymer block (C) and the polymer block (D) may not contain each other's monomer components.

  Moreover, the said polymer block (C) and the polymer block (D) may contain another monomer unit as needed. Specific examples of such other monomers are the polymer blocks (A1) and (A2) of the acrylic triblock copolymer (I) and other monomers optionally contained in the polymer block (B). The same as other monomers exemplified as those used for the monomer unit. When each polymer block contains these other monomers, its content is preferably 20% by mass or less, more preferably 10% by mass, with respect to the total mass of the monomers constituting each polymer block. % Or less, more preferably 5% by mass or less.

  The acrylic diblock copolymer (II) preferably has a (C)-(D) block structure in which the polymer block (C) and the polymer block (D) are bonded in this order. Tack and processability tend to be further improved by containing the acrylic diblock copolymer (II) having such a structure in the adhesive composition.

  The weight average molecular weight (Mw) of the acrylic diblock copolymer (II) is preferably 10,000 to 120,000. It is more preferable that it is 20,000-110,000, it is more preferable that it is 25,000-100,000, and it is 30,000-90,000 from the point of cohesive force and the handleability at the time of manufacture. Is even more preferred. If the Mw of the acrylic diblock copolymer (II) is less than 10,000, the adhesive composition of the present invention may be inferior in cohesion. Moreover, when Mw exceeds 120,000, there exists a possibility that it may be inferior to the handleability at the time of manufacture.

  The molecular weight distribution (Mw / Mn) of the acrylic diblock copolymer (II) is preferably 1.0 to 1.5, and more preferably 1.0 to 1.4.

  When the adhesive composition of the present invention contains the acrylic diblock copolymer (II), the mass ratio of the acrylic triblock copolymer (I) to the acrylic diblock copolymer (II) Is not particularly limited, but in order to combine adhesion, cohesion and adhesion properties in a balanced manner, acrylic triblock copolymer (I): acrylic diblock copolymer (II) = 100: It is preferably 1 to 100: 500, and more preferably 100: 1 to 100: 300.

  The method for producing the acrylic triblock copolymer (I) and the acrylic diblock copolymer (II) used in the present invention is particularly limited as long as a polymer satisfying the conditions of the present invention regarding the chemical structure is obtained. It is possible to adopt a method according to a known method without being Generally, as a method of obtaining a block copolymer having a narrow molecular weight distribution, a method of living polymerizing a monomer which is a structural unit is taken. As a method of such living polymerization, for example, a method of living polymerizing an organic rare earth metal complex as a polymerization initiator (refer to JP-A 06-93060), an alkali metal or alkaline earth metal compound as a polymerization initiator Method of living anionic polymerization in the presence of mineral acid salts such as salts of bimetallics (see JP 05-507737), living anionic polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound Methods (see JP-A-11-335432), atom transfer radical polymerization (ATRP) (see Macromolecular Chemistry and Physics, Volume 201, pp. 1108-1114), and the like.

  Among the above production methods, the method of living anion polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organic aluminum compound results in high transparency of the block copolymer to be obtained, little residual monomer, and odor In addition, when used as a pressure-sensitive adhesive composition, the generation of air bubbles after bonding can be suppressed, which is preferable. Furthermore, the molecular structure of the methacrylic acid ester polymer block becomes highly syndiotactic, and has the effect of enhancing the heat resistance of the adhesive composition, and living polymerization is possible under relatively mild temperature conditions, which is industrially It is also preferable that the environmental load (electric power applied to the refrigerator mainly for controlling the polymerization temperature) is small when producing.

Examples of the organic aluminum compound include the following general formula (1)
AlR ² R ³ R ⁴ (1)
(In formula (1), R ² , R ³ and R ⁴ each independently have an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, and a substituent Aryl group, aralkyl group which may have a substituent, alkoxy group which may have a substituent, aryloxy group which may have a substituent, or N, N-disubstituted amino group Or R ² is any of the above-mentioned groups, and R ³ and R ⁴ together form an arylenedioxy group which may have a substituent. Aluminum compounds are mentioned.

  As the organoaluminum compound represented by the above general formula (1), isobutyl bis (2,6-di-tert-butyl-4-methylphenoxy) from the viewpoints of the height of living property of polymerization, ease of handling, etc. Aluminum, isobutylbis (2,6-di-tert-butylphenoxy) aluminum, isobutyl [2,2'-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum and the like are preferably mentioned.

  Examples of the organic alkali metal compounds include alkyllithiums and alkyldilithiums such as n-butyllithium, sec-butyllithium, isobutyllithium, tert-butyllithium, n-pentyllithium, tetramethylenedilithium and the like; phenyllithium, p Aryllithiums and aryldilithiums such as tolyllithium and lithium naphthalene; aralkyllithiums and aralkyldilithiums such as dilithium formed by the reaction of benzyllithium, diphenylmethyllithium, diisopropenylbenzene and butyllithium; lithium such as lithium dimethylamide Amides; and lithium alkoxides such as methoxylithium and ethoxylithium can be mentioned. These may be used alone or in combination of two or more. Among them, alkyllithium is preferable because polymerization initiation efficiency is high, among which tert-butyllithium and sec-butyllithium are more preferable, and sec-butyllithium is more preferable.

  The living anionic polymerization is usually carried out in the presence of a solvent inert to the polymerization reaction. Examples of the solvent include aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as chloroform, methylene chloride and carbon tetrachloride; ethers such as tetrahydrofuran and diethyl ether; Be

  In the block copolymer, for example, a step of forming a desired polymer block (polymer block (A2), polymer block (B), etc.) at a desired living polymer end obtained by polymerizing a monomer After repeating the desired number of times, it can be produced by stopping the polymerization reaction. Specifically, for example, a first step of polymerizing a monomer forming a first polymer block with a polymerization initiator comprising an organic alkali metal compound in the presence of an organic aluminum compound, and a second polymer block The weight obtained through a multistage polymerization process including a second step of polymerizing the monomer to be formed, and a third step of polymerizing the monomer which forms the third polymer block, if necessary. The acrylic triblock copolymer (I) and the acrylic diblock copolymer (II) can be produced by reacting the active end of the combination with an alcohol or the like to stop the polymerization reaction. According to the method as described above, a triblock copolymer consisting of polymer block (A1) -polymer block (B) -polymer block (A2), polymer block (C) -polymer block (D) The diblock copolymer which consists of can be manufactured.

  The polymerization temperature is 0 to 100 ° C. when forming polymer blocks (A1), (A2) and (C), and −50 to 50 ° C. when forming polymer blocks (B) and (D). preferable. When the polymerization temperature is lower than the above range, the progress of the reaction is delayed, and it takes a long time to complete the reaction. On the other hand, when the polymerization temperature is higher than the above range, the deactivation of the living polymer terminal is increased, and the molecular weight distribution becomes broad, or a desired block copolymer can not be obtained. Each polymer block can be polymerized in the range of 1 second to 20 hours.

(Tackifying resin)
The tackifier resin is contained in the adhesive composition of the present invention. By including the tackifying resin in the adhesive composition of the present invention, adhesion, tackiness, and compatibility are improved. In addition, in the adhesive composition of this invention, it is a preferable aspect that the plasticizer mentioned later is not contained.

  As the tackifying resin which can be added to the adhesive composition of the present invention, any tackifying resin conventionally used in pressure-sensitive adhesives can be used and is not particularly limited. For example, rosin-based resins (rosin, Rosin derivatives, hydrogenated rosin derivatives, etc.), terpene resins, terpene phenol resins, (hydrogenated) petroleum resins, styrene resins, xylene resins, hydrogenated aromatic copolymers, phenolic resins, coumarone-indene resins And the like.

  In the present invention, the rosin-based resin is an amber-colored, amorphous natural resin obtained from pine, and its main component is a mixture of abietic acid and its isomer. In addition, resins modified by esterification, polymerization, hydrogenation and the like utilizing the reactivity of this abietic acid or its isomer are also included in the rosin resin. For example, unmodified rosins (eg, tall rosins, gum rosins, and wood rosins), polymerized rosins, disproportionated rosins, hydrogenated rosins, maleic acid modified rosins, fumaric acid modified rosins, and esters thereof (eg, glycerol esters, pentamers) Erythritol ester, methyl ester, ethyl ester, butyl ester, ethylene glycol ester and the like) and those obtained by further modifying such as hydrogenation (hereinafter, also referred to as hydrogenation), etc. are mentioned, and in particular, heat resistance and color resistance viewpoint And hydrogenated rosin esters are preferably used.

In the present invention, a terpene resin is an oligomer obtained by polymerizing a raw material containing a terpene monomer. In addition, an oligomer obtained by subjecting the thus obtained oligomer to modification such as hydrogenation is also included in the terpene resin. Terpene generally means a polymer of isoprene (C ₅ H ₈ ), and is classified into monoterpene (C ₁₀ H ₁₆ ), sesquiterpene (C ₁₅ H ₂₄ ), diterpene (C ₂₀ H ₃₂ ), etc. Ru. The terpene monomer is a monomer having these as a basic skeleton, and, for example, α-pinene, β-pinene, dipentene, limonene, myrcene, alloocimene, osimene, α-ferrane drain, α-terpinene, γ -Terpinene, terpinorene, 1,8-cineole, 1,4-cineole, α-terpinneol, β-terpinneol, γ-terpinneol, sabinene, paramentadienes, carenes and the like. Further, as a raw material containing a terpene monomer, another monomer copolymerizable with the terpene monomer, for example, a coumarone monomer such as benzofuran (C ₈ H ₆ O); styrene, α- Vinyl aromatic compounds such as methylstyrene, vinyltoluene, divinyltoluene and 2-phenyl-2-butene; phenol, cresol, xylenol, propylphenol, norylphenol, hydroquinone, resorcin, methoxyphenol, bromophenol, bisphenol A, bisphenol F Etc. may be contained. As an oligomer obtained by polymerizing the raw material containing the other monomer copolymerizable with the said terpene-type monomer, terpene phenol-type resin etc. are mentioned. Further, those obtained by modifying the oligomer thus obtained by hydrogenation or the like are also included in the terpene resin.

In this invention the (hydrogenated) petroleum resin consists C ₅ fraction, C ₉ fraction, C purified components of ₅ fraction, purified components of C ₉ fraction, or a mixture thereof fractions or purified components It is an oligomer obtained by polymerizing a raw material. Further, those obtained by modifying the oligomer obtained in this way by hydrogenation and the like are also included in the above (hydrogenated) petroleum resin. Note that the _{C 5} fraction, typically, cyclopentadiene, dicyclopentadiene, isoprene, 1,3-pentadiene, 2-methyl-1-butene, 2-methyl-2-butene, 1-pentene, 2-pentene and cyclopentene and the like are included, the C ₉ fraction, usually, styrene, allyl benzene, alpha-methyl styrene, vinyl toluene, include β- methylstyrene and indene. Also, the C ₉ fraction may contain small amounts of C ₈ fraction and C ₁₀ fraction.

The (hydrogenated) petroleum resin, C ₅ fraction or a C ₅ resin purified components were the raw material, C ₉ fraction or C ₉ resins the purified components to the raw material, C ₅ fraction or purified components thereof the mixture of the C ₉ fraction or a purified component was the raw material is roughly classified into C ₅ -C ₉ copolymer resin. Among these, hydrogenated petroleum resins are preferably used particularly from the viewpoint of heat resistance and color resistance.

  In the present invention, aromatic hydrocarbon resins such as styrene resins, xylene resins, hydrogenated aromatic copolymers, and phenolic resins are, for example, styrene, α-methylstyrene, vinyltoluene, β-methylstyrene, divinyltoluene 2-phenyl-2-butene, methoxystyrene, t-butylstyrene, chlorostyrene, indene, methylindene, phenol, cresol, xylenol, propylphenol, norylphenol, hydroquinone, resorcin, methoxyphenol, bromophenol, bisphenol A, It is an oligomer obtained by polymerizing a raw material consisting of bisphenol F or a mixture thereof. In addition, those obtained by modifying the oligomer thus obtained by hydrogenation or the like are also included. In addition, coumarone-indene resin etc. are mentioned. Among these, in particular, styrene resins are preferably used from the viewpoints of compatibility, heat resistance and color resistance.

  These tackifying resins may be contained singly or in combination of two or more. When 2 or more types of these tackifying resins are contained, it is desirable at the point which is excellent in the balance of adhesive force and a tack | tack. Moreover, about the softening point of the said tackifying resin, the thing of 50-160 degreeC is preferable from the point which expresses high adhesive force.

  The content of the tackifier resin is 1 to 190 parts by mass with respect to 100 parts by mass of the acrylic triblock copolymer (I). When the adhesive composition of the present invention contains the acrylic diblock copolymer (II), the total of the acrylic triblock copolymer (I) and the acrylic diblock copolymer (II) The amount is preferably 1 to 190 parts by mass with respect to 100 parts by mass. When the tackifier resin is a rosin resin, terpene phenol resin, styrene resin, xylene resin, hydrogenated aromatic copolymer, phenol resin, coumarone-indene resin, etc., the content of the tackifier resin is in the above range If it exists, it is excellent in the balance of the adhesive force, tackiness and cohesion of the adhesive composition. The content of the tackifier resin is preferably 10 to 180 parts by mass with respect to 100 parts by mass of the acrylic triblock copolymer (I), from the viewpoint of achieving higher adhesive strength, tackiness and cohesion, More preferably, it is 15 to 170 parts by mass. When the adhesive composition of the present invention contains the acrylic diblock copolymer (II), the total of the acrylic triblock copolymer (I) and the acrylic diblock copolymer (II) It is preferable that it is 10-180 mass parts with respect to 100 mass parts, and it is more preferable that it is 15-170 mass parts.

  On the other hand, when the tackifying resin is a (hydrogenated) petroleum-based resin or a terpene-based resin composed only of terpene-based monomers, the content is selected from the viewpoint of compatibility with the acrylic triblock copolymer. It tends to be difficult to improve. From the viewpoint of adhesion, tackiness, cohesion, and compatibility, the content of the tackifying resin is preferably 2 to 40 parts by mass with respect to 100 parts by mass of the acrylic triblock copolymer (I), It is more preferable that it is 2-20 mass parts. When the adhesive composition of the present invention contains the acrylic diblock copolymer (II), the total of the acrylic triblock copolymer (I) and the acrylic diblock copolymer (II) It is preferable that it is 2-40 mass parts with respect to 100 mass parts, and it is more preferable that it is 2-20 mass parts.

(Plasticizer)
The adhesive composition of the present invention may contain a plasticizer. By containing a plasticizer in the adhesive composition of the present invention, an adhesive composition excellent in the balance between adhesion and tack can be obtained, and further, generally, as the entire adhesive composition. Cost can be reduced.

  Examples of such plasticizers include phthalic acid esters such as dibutyl phthalate, di n-octyl phthalate, bis (2-ethylhexyl) phthalate, bis (2-ethylhexyl) terephthalate, di n-decyl phthalate, diisodecyl phthalate and the like; Adipates such as bis (2-ethylhexyl) adipate, diisodecyl adipate and di n-octyl adipate; sebacates such as bis (2-ethylhexyl) sebacate and di n-butyl sebacate; bis (2-ethyl hexyl) azelate etc Azelaic acid esters; citric acid esters such as tributyl acetyl citrate; paraffins such as chlorinated paraffin; glycols such as polypropylene glycol; epoxy such as epoxidized soybean oil and epoxidized linseed oil Vegetable oils; phosphoric esters such as trioctyl phosphate and triphenyl phosphate; phosphorous esters such as triphenyl phosphite; esters of adipic acid and 1,3-butylene glycol; benzoic acid and dipropylene glycol Esters such as esters of low molecular weight polybutene, low molecular weight polyisobutylene, low molecular weight polymers such as low molecular weight polyisoprene; acrylic oligomers such as n-butyl polyacrylate and 2-ethylhexyl polyacrylate; Diana Process Oil PW Paraffin oil such as series (made by Idemitsu Kosan Co., Ltd.), SUNPURE LW70 and P series (made by Nippon Sun Oil Co., Ltd.); SUNPURE N90 and NX90, SUNTHENE series (made by Nippon Sun Oil Co., Ltd.) Naphthenic oils; JSO AROMA790 (manufactured by Japan Sun Oil Co., Ltd.), Vivatec500 (H & R Co., Ltd.) aromatic oil and the like, these are used alone or in combination.

  The content of the plasticizer is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and 60 parts by mass or less with respect to 100 parts by mass of the acrylic triblock copolymer (I). Is more preferred. When the adhesive composition of the present invention contains the acrylic diblock copolymer (II), the total of the acrylic triblock copolymer (I) and the acrylic diblock copolymer (II) It is preferable that it is 80 mass parts or less with respect to 100 mass parts, It is more preferable that it is 70 mass parts or less, It is more preferable that it is 60 mass parts or less. When the content of the plasticizer is in the above-mentioned range, the adhesive composition having no bleeding and excellent in transparency can be obtained. In addition, in order to obtain the effect due to the plasticizer included in the adhesive composition, it is desirable that the content is usually 5 parts by mass or more with respect to 100 parts by mass of the acrylic triblock copolymer (I). When the adhesive composition of the present invention contains the acrylic diblock copolymer (II), the total of the acrylic triblock copolymer (I) and the acrylic diblock copolymer (II) It is desirable that the content is usually 5 parts by mass or more with respect to 100 parts by mass.

  The pressure-sensitive adhesive composition of the present invention may contain other polymers, as long as the effects of the present invention are not impaired; softeners, heat stabilizers, light stabilizers, antistatic agents, flame retardants, blowing agents, colorants, Additives such as a staining agent, a refractive index adjusting agent, a filler, a curing agent and an anti-sticking agent may be contained. These other polymers and additives may be contained singly or in combination of two or more.

  Other polymers include, for example, acrylic resins such as polymethyl methacrylate and (meth) acrylic acid ester copolymer; polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polybutene-1, poly-4-methyl Pentene-1, olefin resins such as polynorbornene; ethylene ionomers; polystyrene, styrene-maleic anhydride copolymer, high impact polystyrene, AS resin, ABS resin, AES resin, AES resin, AAS resin, ACS resin, MBS resin, etc. Styrene-based resins; styrene-methyl methacrylate copolymers; polyester resins such as polyethylene terephthalate, polybutylene terephthalate and polylactic acid; polyamides such as nylon 6, nylon 66 and polyamide elastomer; polycarbonate; polyvinyl chloride; Polyvinyl chloride; Polyvinyl alcohol; Ethylene-vinyl alcohol copolymer; Polyacetal; Polyvinylidene fluoride; Polyurethane; Modified polyphenylene ether; Polyphenylene sulfide; Silicone rubber modified resin; Acrylic rubber; Silicone rubber; Styrene such as SEPS, SEBS, SIS Thermoplastic elastomers; olefin rubbers such as IR, EPR, EPDM, and the like. Among these, from the viewpoint of compatibility with the acrylic triblock copolymer (I) contained in the above-mentioned adhesive composition, acrylic resin, ethylene-vinyl acetate copolymer, AS resin, polylactic acid, Preferred are polyvinylidene fluoride and styrenic thermoplastic elastomers, and (meth) acrylic acid ester copolymers (different from acrylic triblock copolymers (I) and acrylic diblock copolymers (II) of the present invention) Is more preferred.

  Examples of the filler include inorganic fibers such as glass fibers and carbon fibers, and organic fibers; inorganic fillers such as calcium carbonate, talc, titanium oxide, silica, clay, barium sulfate and magnesium carbonate; carbon black and the like . When the inorganic fiber and the organic fiber are contained, durability is imparted to the resulting pressure-sensitive adhesive composition. When the inorganic filler is contained, heat resistance and weather resistance are imparted to the resulting adhesive composition.

  When the adhesive composition of the present invention contains a curing agent, it can be suitably used as a curable adhesive. Examples of the curing agent include photocuring agents such as UV curing agents, and thermosetting agents, and examples thereof include benzoins, benzoin ethers, benzophenones, anthraquinones, benzyls, acetophenones, diacetyls, and the like. . Specifically, benzoin, α-methylolbenzoin, α-t-butylbenzoin, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, α-methylol benzoin methyl ether, α -Methoxybenzoin methyl ether, benzoin phenyl ether, benzophenone, 9,10-anthraquinone, 2-ethyl-9,10-anthraquinone, benzyl, 2,2-dimethoxy-1,2-diphenylethane-1-one (2,2 -Dimethoxy-2-phenylacetophenone), diacetyl and the like. The curing agent may be contained singly or in combination of two or more.

  From the viewpoint of enhancing the effect of the curing agent, for example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-halogenated acrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, itaconic acid, and acrylic acid ester , Esters such as methacrylic acid ester, crotonic acid ester, maleic acid ester; acrylamide; methacrylamide; N-methylol acrylamide, N-hydroxyethyl acrylamide, acrylamide derivatives such as N, N- (dihydroxyethyl) acrylamide; N- methylol methacryl Methacrylamide derivatives such as amide, N-hydroxyethyl methacrylamide, N, N- (dihydroxyethyl) methacrylamide; vinyl esters; vinyl ethers; mono-N-vinyl derivatives; monomers such as styrene derivatives; An oligomer or the like containing the above-mentioned monomer as a constituent component may be further contained in the adhesive composition of the present invention. From the viewpoint of enhancing the durability, esters such as acrylic acid esters, methacrylic acid esters, crotonic acid esters and maleic acid esters; vinyl ethers; styrene derivatives; and oligomers containing the above-mentioned monomers as a component are preferable. Further, in addition to these monomers, a crosslinking agent composed of a monomer or oligomer having two or more functional groups may be further contained.

  When the adhesive composition of the present invention contains an anti-stick agent, improvement in the handling can be expected. Examples of the anti-stick agent include fatty acids such as stearic acid and palmitic acid; fatty acid metal salts such as calcium stearate, zinc stearate, magnesium stearate, potassium palmitate, sodium palmitate; polyethylene wax, polypropylene wax, montanic acid Waxes such as waxes; low molecular weight polyolefins such as low molecular weight polyethylene and low molecular weight polypropylene; acrylic resin powder; polyorganosiloxanes such as dimethylpolysiloxane; such as octadecylamine, alkyl phosphate, fatty acid ester, ethylene bis stearylamide Examples thereof include amide resin powder, fluorocarbon resin powder such as tetrafluoroethylene resin, molybdenum disulfide powder, silicone resin powder, silicone rubber powder, silica and the like.

  The method for producing the pressure-sensitive adhesive composition of the present invention is not particularly limited, and, for example, each component is usually 100 using a known mixing or kneading apparatus such as a kneader ruler, an extruder, a mixing roll, or a Banbury mixer. It can be produced by mixing at a temperature in the range of -250 ° C. Moreover, after melt | dissolving and mixing each component in the organic solvent, you may manufacture by distilling off the said organic solvent. The obtained pressure-sensitive adhesive composition may be used by heating and melting, or may be dissolved in a solvent and used as a solution-type pressure-sensitive adhesive. Examples of the solvent include toluene, ethyl acetate, ethylbenzene, methylene chloride, chloroform, tetrahydrofuran, methyl ethyl ketone, dimethyl sulfoxide, a mixed solvent of toluene and ethanol, and the like. Among these, toluene, ethylbenzene, ethyl acetate and methyl ethyl ketone are preferable.

  When the adhesive composition of the present invention is used by heating and melting, the melt viscosity is preferably low from the viewpoint of processability and handleability. On the other hand, it is preferable that the melt viscosity is high from the viewpoint of achieving both the adhesive properties of the adhesive composition and the high holding power (creep resistance, heat resistant holding power).

  The pressure-sensitive adhesive composition of the present invention is a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition, a pressure-sensitive adhesive layer in the form of a laminate (for example, a laminate film or a laminate sheet) containing the It is suitably used for adhesive products.

  When the adhesive composition of the present invention is used by heating and melting to form the above-mentioned adhesive layer, for example, hot melt coating method, T-die method, inflation method, calendar molding method, lamination method, etc. It can be formed into a sheet-like or film-like shape. For example, an adhesive layer can be formed on a film or sheet of a heat-resistant material such as polyethylene terephthalate by using a hot melt coater to melt coat the adhesive composition. In the case where the melt viscosity of the adhesive composition of the present invention is high, for example, when the melt viscosity at 180 ° C. exceeds 20,000 mPa · s, heating is performed at a higher temperature, so from T die A hot melt coating method in which the heated melt is applied onto the support in a noncontact manner is preferable from the viewpoint of thickness control of the adhesive and pressure-sensitive adhesive layer, homogeneity, and heat resistance required for the support. When acrylic triblock copolymer (I) having a higher melt viscosity is used, pellets of acrylic triblock copolymer (I) and, if necessary, acrylic diblock copolymer (II) are used. After dry blending of the pellets, or while feeding the liquid acrylic diblock copolymer (II) to the acrylic triblock copolymer (I) as needed using a liquid addition facility, A viscous and adhesive layer can be formed by applying a mixture obtained by kneading with a screw extruder into a pellet once using a twin-screw extrusion laminator or the like. When the adhesive composition of the present invention is used by dissolving it in a solvent, for example, a heat-resistant material such as polyethylene terephthalate or a flat plate or a roll such as a steel belt is used as a support. Adhesive composition including acrylic triblock copolymer (I) using a roll coater, die coater, comma coater, etc., if necessary, acrylic diblock copolymer (II), tackifying resin, etc. The adhesive layer can be formed using a method (solution casting method) of applying a solution in which a substance is dissolved in a solvent and removing the solvent by drying (solution casting method).

  The method for removing the solvent by drying is not particularly limited, and a conventionally known method can be used, but it is preferable to divide the drying into a plurality of steps. When the drying is performed in a plurality of stages, the first stage drying is performed at a relatively low temperature to suppress foaming due to the rapid evaporation of the solvent, and the second and subsequent stages of drying are sufficiently performed. More preferred is a method of drying at high temperature to remove the solvent.

  The concentration of the adhesive composition containing the acrylic triblock copolymer (I), the acrylic diblock copolymer (II) if necessary, and the tackifying resin in the solution is The solubility is determined in consideration of the solvent solubility in the solvent, the viscosity of the solution obtained, etc., but the preferable lower limit is 5% by mass, and the preferable upper limit is 70% by mass.

  The laminate can be obtained by laminating a mucoadhesive layer comprising the mucoadhesive composition of the present invention and various substrates such as paper, cellophane, plastic materials, cloth, wood, and metals. Since the adhesive composition of the present invention is excellent in transparency and weatherability as it is a base material layer which consists of a transparent material, since a transparent layered product is obtained, it is suitable. As a base material layer made of a transparent material, polyethylene terephthalate, triacetyl cellulose, polyvinyl alcohol, cycloolefin resin, styrene-methyl methacrylate copolymer, polypropylene, polyethylene, polyvinyl chloride, ethylene-vinyl acetate copolymer And copolymers of polymers such as polycarbonate, polymethyl methacrylate, polyethylene or polypropylene with various monomers, mixtures of two or more of these polymers, and base layers made of glass etc. It is not limited to these.

  As a structure of the said laminated body, 2 layer structure of the adhesion and adhesion layer which consists of a pressure-sensitive adhesive composition of the present invention and a base material layer, the base material layer 2 layer, and the adhesion and pressure-sensitive adhesive composition of the present invention Three-layer structure (base layer / adhesive / layer / base layer) with the adhesive / adhesive layer consisting of two different adhesive / adhesive layers consisting of a substrate layer and the adhesive / adhesive composition of the present invention a) and the four-layer structure of the adhesive and pressure sensitive adhesive layer (b) and the substrate layer (substrate layer / adhesive / adhesive layer (a) / adhesive / adhesive layer (b) / substrate layer), the substrate layer and the present A four-layer constitution comprising a mucoadhesive layer (a) comprising the mucoadhesive composition of the invention, a mucoadhesive layer (c) comprising another material, and a substrate layer (base layer / mucoadhesive layer (a ) / Adhesive / adhesive layer (c) / substrate layer), 5 layers of substrate layer 3 layers and adhesive / adhesive layer 2 layers comprising the adhesive / adhesive composition of the present invention (substrate layer / adhesive) Examples include, but are not limited to, adhesion layer / substrate layer / cohesion / adhesion layer / substrate layer) and the like.

  The thickness ratio of the above laminate is not particularly limited, but it is in the range of base material layer / adhesive / adhesive layer = 1/100 to 1000/1 from the tackiness, durability, and handleability of the resulting tacky-adhesive product. Is preferable, and the range of 1/200 to 200/1 is more preferable.

  When producing the above-mentioned layered product, after forming an adhesive layer and a substrate layer, respectively, you may bond them together by the lamination method etc. Even if an adhesive layer is formed directly on a substrate layer Good. Alternatively, the layer structure may be formed at once by coextrusion of the tacky-adhesive layer and the base material layer, and a laminate may be produced, for example, as a coextrusion film or coextrusion sheet.

  In the laminate of the present invention, surface treatment such as corona discharge treatment or plasma discharge treatment may be performed in advance on the surface of the base material layer in order to enhance the adhesion between the base material layer and the adhesive layer. Moreover, you may form an anchor layer in the surface of at least one of the said mucoadhesive layer and a base material layer using resin etc. which have adhesiveness.

  Examples of the resin used for such an anchor layer include ethylene-vinyl acetate copolymer, ionomer, block copolymer (for example, styrenic triblock copolymer such as SIS and SBS, and diblock copolymer), Ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, etc. are mentioned. The anchor layer may be a single layer or two or more layers.

  When forming an anchor layer, the method in particular is not restrict | limited, For example, the method of applying the solution which contains the said resin in a base material layer, and forming an anchor layer, the composition containing the said resin etc. which becomes an anchor layer A method of heating and melting and forming an anchor layer on the surface of a base material layer by a T-die or the like can be mentioned.

  Moreover, when forming an anchor layer, you may co-extrude the said resin used as an anchor layer, and the adhesive composition of this invention, and may integrally laminate an anchor layer and an adhesive layer on the base material surface. Alternatively, a resin to be an anchor layer and a pressure-sensitive adhesive composition may be sequentially laminated on the surface of a substrate layer, and furthermore, when the substrate layer is a plastic material, a plastic material to be a substrate layer, anchor The layer resin and the adhesive composition may be coextruded simultaneously.

  The pressure-sensitive adhesive comprising the pressure-sensitive adhesive composition of the present invention can be used in various applications. In addition, the tacky-adhesive layer composed of the tacky-adhesive composition can be used alone as a tacky-adhesive sheet, and a laminate including the tacky-adhesive layer can be applied to various uses. For example, for protection such as surface protection, for masking, for binding, for packaging, for business, for labels, for decoration and display, for bonding, for dicing tape, for sealing, for anticorrosion and waterproofing, for medical and hygiene, glass Adhesives and adhesives for shatterproofing, electrical insulation, holding and fixing of electronic devices, for manufacturing semiconductors, for optical display films, for adhesive type optical films, for electromagnetic wave shielding, or for sealing materials of electric and electronic parts An adhesive tape, a film, a sheet, etc. are mentioned. Specific examples will be given below.

  Adhesives for surface protection, adhesive tapes or films can be used for various materials such as metal, plastic, rubber, wood, etc. Specifically, in the case of paint surface, plastic plastic working or deep drawing of metal, It can be used for surface protection of automobile members and optical members. Examples of the automobile member include a painted skin, a wheel, a mirror, a window, a light, a light cover and the like. As the optical member, various image display devices such as liquid crystal display, organic EL display, plasma display, field emission display, etc .; polarizing film, polarizing plate, retardation plate, light guide plate, diffusion plate, optical disc constituting film such as DVD; -For example, precision fine coat face plates for optical applications.

  For applications such as adhesives for masking, tapes and films, masking at the time of production of printed circuit boards and flexible printed circuit boards; masking at the time of plating and solder processing in electronic devices; production of vehicles such as automobiles, vehicles, architecture Painting of objects, printing on textiles, masking at civil engineering work closing, etc. may be mentioned.

  As a binding application, a wire harness, an electric wire, a cable, a fiber, a pipe, a coil, a winding, a steel material, a duct, a plastic bag, food, vegetables, flowers, etc. can be mentioned.

  Examples of packaging applications include heavyweight packaging, export packaging, cardboard box sealing, can sealing and the like.

  Examples of business applications include general office use, cover, repair of books, drafting, memos, and the like.

  Label applications include price, product indication, tag, POP, sticker, stripe, name plate, decoration, for advertising, etc.

  Examples of the label include paper, processed paper (paper subjected to aluminum deposition processing, aluminum lamination processing, varnish processing, resin processing, etc.), synthetic papers and the like; cellophane, plastic material, cloth, wood and metal The label which makes a film etc. a substrate is mentioned. Specific examples of the substrate include, for example, high quality paper, art paper, cast paper, thermal paper, foil paper; polyethylene terephthalate film, polyvinyl chloride film, OPP film, polylactic acid film, synthetic paper, synthetic paper thermal, overlamination A film etc. are mentioned. Among them, the pressure-sensitive adhesive composition of the present invention can be suitably used for a label using a substrate made of a transparent material in that it is excellent in transparency and weather resistance. In addition, since the adhesive composition of the present invention has little discoloration with time, it can be suitably used for a thermal label or a thermal label based on synthetic paper thermal.

  Examples of adherends of the label include plastic products such as plastic bottles and foamed plastic cases; paper products such as cardboard boxes; cardboard products; glass products such as glass bottles; metal products; and other inorganic material products such as ceramics Be

  The label consisting of a laminate including the pressure-sensitive adhesive layer consisting of the adhesive composition of the present invention may have little adhesion promotion at the time of storage at a temperature slightly higher than room temperature (e.g. 40.degree. C.) and peel off after use without adhesive residue it can. Moreover, it can be bonded to the adherend even at low temperature (-40 to + 10 ° C), and does not peel off even if stored at low temperature (-40 to + 10 ° C).

  Examples of decoration / display applications include danger indication seals, line tapes, wiring markings, luminous tapes, reflective sheets and the like.

  As an adhesive type optical film application, for example, a polarizing film, a polarizing plate, a retardation film, a viewing angle widening film, a brightness enhancement film, an antireflection film, an antiglare film, a color filter, a light guide plate, a diffusion film, a prism sheet, an electromagnetic wave shielding film , Near-infrared absorbing film, functional composite optical film, film for ITO bonding, impact resistance-imparting film, brightness improving film, visibility improving film etc Optical films and the like. The pressure-sensitive adhesive optical film includes a film obtained by forming a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition of the present invention on a protective film used to protect the surface of the optical film. The adhesive type optical film is suitably used for various image display devices such as liquid crystal display devices, PDPs, organic EL display devices, electronic paper, game machines, mobile terminals and the like.

  Examples of the electrical insulation application include protective coating or insulation of a coil, interlayer insulation such as a motor and a transformer, and the like.

  Examples of applications for holding and fixing electronic devices include carrier tape, packaging, fixing of a Braun tube, splicing, rib reinforcement and the like.

  Examples of semiconductor manufacturing include those for protecting silicone wafers.

  Bonding applications include various bonding fields, automobiles, trains, electrical devices, printing plate fixing, construction, nameplate fixing, general household use, rough surfaces, uneven surfaces, adhesion to curved surfaces, and the like.

  Sealing applications include heat insulation, anti-vibration, waterproof, moisture-proof, soundproof or dustproof sealing.

  Examples of anticorrosion / waterproof applications include corrosion protection of gas and water pipes, corrosion protection of large diameter pipes, and corrosion protection of civil engineering buildings.

  For medical and hygiene applications, analgesic and anti-inflammatory agents (plasters, paps), agents for treating ischemic heart disease, female hormone replacement agents, bronchodilators, cancer pain relieving agents, smoking cessation adjuncts, patches for colds, patches for preventing epilepsy, Applications for percutaneous absorption such as keratin softener; First-aid bandage (with bactericidal agent), surgical dressing, surgical tape, bandage, hemostatic plaque, tape for human excrement treatment attachment (colostomy tape), suture tape, antibacterial tape , Fixed tape, self-adhesive bandage, oral mucous membrane adhesive tape, tape for sports, tape for depilation etc .; various tape applications; face pack, eye moisturizing sheet, cosmetic use such as exfoliation pack; cooling sheet, warmth, dustproof, Waterproof, for catching insects, etc. can be mentioned.

  Examples of applications of encapsulants for electronic and electrical components include liquid crystal monitors and solar cells.

  EXAMPLES The present invention will be specifically described by way of Examples and Comparative Examples, but the present invention is not limited by the following Examples. In addition, in the manufacture examples 1-13 shown below, a monomer and other compounds were dry-purified by the conventional method, and it degased and used with nitrogen. Also, transfer and supply of monomers and other compounds to the reaction system were performed under a nitrogen atmosphere.

In the following examples, the weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) of the block copolymer were determined by GPC in terms of polystyrene. The measuring apparatus and conditions used by GPC are as follows.
[Device and conditions for GPC measurement]
Device: GPC apparatus "HLC-8020" manufactured by Tosoh Corporation
・ Separation column: "TSKgel GMHXL" manufactured by Tosoh Corp., "G4000HXL"
And "G5000HXL" in series · Eluent: tetrahydrofuran · Eluant flow rate: 1.0 ml / min · Column temperature: 40 ° C
・ Detection method: Differential refractive index (RI)
In the following examples, the content of each polymer block in the block copolymer was determined by ¹ H-NMR measurement. ^The measuring devices and conditions used in the ¹ H-NMR measurement are as follows.
[Apparatus and conditions of ¹ H-NMR measurement]
Device: Nuclear magnetic resonance device "JNM-ECX400" manufactured by JEOL Ltd.
-Heavy solvent: deuterated chloroform
^{In the 1} H-NMR spectrum, signals at around 3.6 ppm and 4.0 ppm are respectively the ester group (—O—CH ₃ ) of methyl methacrylate unit and the ester group (—O—C H ₂ ) of acrylic ester unit The content of each polymer block was determined by the ratio of its integral value, which is attributed to -CH ₂ -CH ₂ -CH ₃ ).

The evaluation of the pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition was carried out by the following method.
[Heat resistant holding power]
The heat retention was measured in accordance with ASTM D4498. That is, an adhesive tape having a 25 μm thick adhesive layer prepared by the method described later is attached to a stainless steel (SUS 304) plate (bright annealed product) with a width of 25 mm × length 25 mm, and a load of 500 g is suspended. The temperature was raised from 40.degree. C. to 205.degree. C. at a rate of 0.5.degree. The thing whose temperature is 125 degreeC or more was made into "A" (holding power: good), and the thing less than 125 degreeC was made into "B" (holding power: bad).
[tack]
The resistance at the time of pressing the thumb off at 25 ° C. to the surface of the tacky-adhesive layer surface of the tacky-adhesive tape having a tacky-adhesive layer having a thickness of 25 μm prepared by the method described later was sensory evaluated as tackiness. Here, it was shown that it was suitable as a pressure-sensitive adhesive, with those with a sense of tack being "A" simply by gently pressing a finger and those with a sense of tack when pressed strongly by a finger "B". On the other hand, those without tackiness were regarded as "C" and not suitable as pressure sensitive adhesives.
[Coatability]
The pressure-sensitive adhesive composition obtained in Examples and Comparative Examples described later is coated on a 100 μm polyester film at a temperature of 180 ° C. to a coating thickness of 40 μm using a coater, Visually observed, "A" (good / coated surface is mirror-like), "B" (defective / defective / defective coating surface has many bumps or clear coating unevenness) The coating properties were evaluated separately.

Production Example 1 [Production of Acrylic Triblock Copolymer (I-1)]
(1) After adding a three-way cock to a 2 L three-necked flask and replacing the inside with nitrogen, 1021 g of toluene and 8.48 g of 1,2-dimethoxyethane are added while stirring at room temperature, followed by addition of isobutyl bis (2, 2, 16.8 g of a toluene solution containing 8.47 mmol of 6-di-t-butyl-4-methylphenoxy) aluminum was added, and 0.621 g of a cyclohexane solution of sec-butyllithium containing 1.06 mmol of sec-butyllithium was further added. added.
(2) Subsequently, 20.8 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to -30 ° C, and 218 g of n-butyl acrylate was dropped over 2 hours, and after completion of the dropping, the mixture was stirred at -30 ° C for 5 minutes.
(4) Furthermore, 20.8 g of methyl methacrylates were added to this, and it stirred at room temperature overnight.
(5) After the polymerization reaction was stopped by adding 5.0 g of methanol, the obtained reaction solution was poured into 15 kg of methanol to precipitate a precipitate. Thereafter, the precipitate was recovered and dried to obtain 240 g of an acrylic triblock copolymer (I-1). The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the obtained acrylic triblock copolymer (I-1) were determined by GPC measurement of the above-mentioned method. Moreover, content of the polymer block which consists of a methyl methacrylate unit in acrylic type triblock copolymer (I-1) was calculated | required by < ¹ > H-NMR measurement mentioned above.

<< Production Example 2 >> [Production of Acrylic Triblock Copolymer (I-2)]
(1) After adding a three-way cock to a 2 L three-necked flask and replacing the inside with nitrogen, 1021 g of toluene and 8.48 g of 1,2-dimethoxyethane are added while stirring at room temperature, followed by addition of isobutyl bis (2, 2, 16.8 g of a toluene solution containing 8.47 mmol of 6-di-t-butyl-4-methylphenoxy) aluminum was added, and 0.621 g of a cyclohexane solution of sec-butyllithium containing 1.06 mmol of sec-butyllithium was further added. added.
(2) Subsequently, 13.0 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to -30.degree. C., 234 g of n-butyl acrylate was dropped over 2 hours, and after completion of dropping, the mixture was stirred at -30.degree. C. for 5 minutes.
(4) Furthermore, 13.0 g of methyl methacrylate was added to this, and it stirred at room temperature overnight.
(5) After the polymerization reaction was stopped by adding 5.0 g of methanol, the obtained reaction solution was poured into 15 kg of methanol to precipitate a precipitate. Thereafter, the precipitate was collected and dried to obtain 240 g of an acrylic triblock copolymer (I-2). The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the obtained acrylic triblock copolymer (I-2) were determined by GPC measurement of the above-mentioned method. Moreover, content of the polymer block which consists of a methyl methacrylate unit in acrylic type triblock copolymer (I-2) was calculated | required by < ¹ > H-NMR measurement mentioned above.

<< Production Example 3 >> [Production of Acrylic Triblock Copolymer (I-3)]
(1) After adding a three-way cock to a 2 L three-necked flask and replacing the inside with nitrogen, while stirring at room temperature, 1020 g of toluene and 7.28 g of 1,2-dimethoxyethane are added, followed by isobutyl bis (2, 2, To this was added 18.0 g of a toluene solution containing 9.07 mmol of 6-di-t-butyl-4-methylphenoxy) aluminum, and further 0.532 g of a cyclohexane solution of sec-butyllithium containing 0.907 mmol of sec-butyllithium added.
(2) Subsequently, 18.6 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to -30 ° C, and 218 g of n-butyl acrylate was dropped over 2 hours, and after completion of the dropping, the mixture was stirred at -30 ° C for 5 minutes.
(4) Furthermore, 23.0 g of methyl methacrylate was added to this, and it stirred at room temperature overnight.
(5) After the polymerization reaction was stopped by adding 5.1 g of methanol, the resulting reaction solution was poured into 15 kg of methanol to precipitate a precipitate. Thereafter, the precipitate was recovered and dried to obtain 240 g of an acrylic triblock copolymer (I-3). The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the obtained acrylic triblock copolymer (I-3) were determined by GPC measurement of the above-mentioned method. Moreover, content of the polymer block which consists of a methyl methacrylate unit in acrylic type triblock copolymer (I-3) was calculated | required by < ¹ > H-NMR measurement mentioned above.

<< Production Example 4 >> [Production of Acrylic Triblock Copolymer (I-4)]
(1) After adding a three-way cock to a 2 L three-necked flask and replacing the inside with nitrogen, 1021 g of toluene and 8.50 g of 1,2-dimethoxyethane are added while stirring at room temperature, followed by addition of isobutyl bis (2, 2, 16.8 g of a toluene solution containing 8.47 mmol of 6-di-t-butyl-4-methylphenoxy) aluminum was added, and 0.621 g of a cyclohexane solution of sec-butyllithium containing 1.06 mmol of sec-butyllithium was further added. added.
(2) Subsequently, 30.3 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to -30.degree. C., 197 g of n-butyl acrylate was dropped over 2 hours, and after completion of dropping, the mixture was stirred at -30.degree. C. for 5 minutes.
(4) Furthermore, 32.0 g of methyl methacrylates were added to this, and it stirred at room temperature overnight.
(5) After the polymerization reaction was stopped by adding 5.0 g of methanol, the obtained reaction solution was poured into 15 kg of methanol to precipitate a precipitate. Thereafter, the precipitate was recovered and dried to obtain 250 g of an acrylic triblock copolymer (I-4). The weight average molecular weight (Mw) of the obtained acrylic triblock copolymer (I-4) was determined by GPC according to the method described above. Moreover, content of the polymer block which consists of a methyl methacrylate unit in acrylic type triblock copolymer (I-4) was calculated | required by < ¹ > H-NMR measurement mentioned above.

<< Production Example 5 >> [Production of Acrylic Triblock Copolymer (I-5)]
(1) After adding a three-way cock to a 2 L three-necked flask and replacing the inside with nitrogen, while stirring at room temperature, 1020 g of toluene and 7.28 g of 1,2-dimethoxyethane are added, followed by isobutyl bis (2, 2, To this was added 18.0 g of a toluene solution containing 9.07 mmol of 6-di-t-butyl-4-methylphenoxy) aluminum, and further 0.532 g of a cyclohexane solution of sec-butyllithium containing 0.907 mmol of sec-butyllithium added.
(2) Subsequently, 12.6 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to -30.degree. C., 234 g of n-butyl acrylate was dropped over 2 hours, and after completion of dropping, the mixture was stirred at -30.degree. C. for 5 minutes.
(4) Furthermore, 13.4 g of methyl methacrylate was added to this, and it stirred at room temperature overnight.
(5) After the polymerization reaction was stopped by adding 5.1 g of methanol, the resulting reaction solution was poured into 15 kg of methanol to precipitate a precipitate. Thereafter, the precipitate was recovered and dried to obtain 250 g of an acrylic triblock copolymer (I-5). The weight average molecular weight (Mw) of the obtained acrylic triblock copolymer (I-5) was determined by GPC according to the method described above. Moreover, content of the polymer block which consists of a methyl methacrylate unit in acrylic type triblock copolymer (I-5) was calculated | required by < ¹ > H-NMR measurement mentioned above.

<< Production Example 6 >> [Production of Acrylic Triblock Copolymer (I-6)]
(1) After adding a three-way cock to a 2 L three-necked flask and replacing the inside with nitrogen, 1022 g of toluene and 6.80 g of 1,2-dimethoxyethane are added while stirring at room temperature, followed by addition of isobutyl bis (2, 2, 16.8 g of a toluene solution containing 8.47 mmol of 6-di-t-butyl-4-methylphenoxy) aluminum was added, and 0.497 g of a cyclohexane solution of sec-butyllithium containing 0.847 mmol of sec-butyllithium was further added added.
(2) Subsequently, 9.01 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to -30.degree. C., 242 g of n-butyl acrylate was dropped over 2 hours, and after completion of dropping, the mixture was stirred at -30.degree. C. for 5 minutes.
(4) Furthermore, 9.18 g of methyl methacrylate was added to this, and it stirred at room temperature overnight.
(5) The polymerization reaction was stopped by adding 4.8 g of methanol, and the resulting reaction solution was poured into 15 kg of methanol to precipitate a precipitate. Thereafter, the precipitate was recovered and dried to obtain 250 g of an acrylic triblock copolymer (I-6). The weight average molecular weight (Mw) of the obtained acrylic triblock copolymer (I-6) was determined by GPC according to the method described above. Moreover, content of the polymer block which consists of a methyl methacrylate unit in acrylic type triblock copolymer (I-6) was calculated | required by < ¹ > H-NMR measurement mentioned above.

<< Production Example 7 >> [Production of Acrylic Triblock Copolymer (I-7)]
(1) After adding a three-way cock to a 2 L three-necked flask and replacing the inside with nitrogen, 939 g of toluene and 21.8 g of 1,2-dimethoxyethane are added while stirring at room temperature, followed by addition of isobutyl bis (2, 2, 32.4 g of a toluene solution containing 16.3 mmol of 6-di-t-butyl-4-methylphenoxy) aluminum was added, and 1.59 g of a cyclohexane solution of sec-butyllithium containing 2.72 mmol of sec-butyllithium was further added added.
(2) Subsequently, 21.7 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to -30.degree. C., 273 g of n-butyl acrylate was dropped over 2 hours, and after completion of dropping, the mixture was stirred at -30.degree. C. for 5 minutes.
(4) Furthermore, 30.2 g of methyl methacrylate was added to this, and it stirred at room temperature overnight.
(5) 10 g of methanol was added to stop the polymerization reaction, and the resulting reaction solution was poured into 15 kg of methanol to precipitate a precipitate. Thereafter, the precipitate was recovered and dried to obtain 310 g of an acrylic triblock copolymer (I-7). The weight average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) of the obtained acrylic triblock copolymer (I-7) were determined by GPC measurement of the above method. Moreover, content of the polymer block which consists of a methyl methacrylate unit in acrylic type triblock copolymer (I-7) was calculated | required by < ¹ > H-NMR measurement mentioned above.

<< Production Example 8 >> [Production of Acrylic Triblock Copolymer (I-8)]
(1) After adding a three-way cock to a 2 L three-necked flask and replacing the inside with nitrogen, while stirring at room temperature, 1020 g of toluene and 7.28 g of 1,2-dimethoxyethane are added, followed by isobutyl bis (2, 2, To this was added 18.0 g of a toluene solution containing 9.07 mmol of 6-di-t-butyl-4-methylphenoxy) aluminum, and further 0.532 g of a cyclohexane solution of sec-butyllithium containing 0.907 mmol of sec-butyllithium added.
(2) Subsequently, 44.5 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to -30.degree. C., 164 g of n-butyl acrylate was dropped over 2 hours, and after completion of dropping, the mixture was stirred at -30.degree. C. for 5 minutes.
(4) Furthermore, 51.6 g of methyl methacrylates were added to this, and it stirred at room temperature overnight.
(5) After the polymerization reaction was stopped by adding 5.1 g of methanol, the resulting reaction solution was poured into 15 kg of methanol to precipitate a precipitate. Thereafter, the precipitate was recovered and dried to obtain 250 g of an acrylic triblock copolymer (I-8). The weight average molecular weight (Mw) of the obtained acrylic triblock copolymer (I-8) was determined by GPC according to the method described above. Moreover, content of the polymer block which consists of a methyl methacrylate unit in acrylic type triblock copolymer (I-8) was calculated | required by < ¹ > H-NMR measurement mentioned above.

<< Production Example 9 >> [Production of Acrylic Triblock Copolymer (I-9)]
(1) After adding a three-way cock to a 2 L three-necked flask and replacing the inside with nitrogen, 1019 g of toluene and 6.07 g of 1,2-dimethoxyethane are added while stirring at room temperature, followed by isobutyl bis (2, 2, 19.6 g of a toluene solution containing 9.83 mmol of 6-di-t-butyl-4-methylphenoxy) aluminum was added, and 0.444 g of a cyclohexane solution of sec-butyllithium containing 0.756 mmol of sec-butyllithium was further added added.
(2) Subsequently, 30.9 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to -30.degree. C., 195 g of n-butyl acrylate was dropped over 2 hours, and after completion of dropping, the mixture was stirred at -30.degree. C. for 5 minutes.
(4) Furthermore, 34.0 g of methyl methacrylates were added to this, and it stirred at room temperature overnight.
(5) After the polymerization reaction was stopped by adding 5.4 g of methanol, the resulting reaction solution was poured into 15 kg of methanol to precipitate a precipitate. Thereafter, the precipitate was recovered and dried to obtain 250 g of an acrylic triblock copolymer (I-9). The weight average molecular weight (Mw) of the obtained acrylic triblock copolymer (I-9) was determined by GPC according to the method described above. Moreover, content of the polymer block which consists of a methyl methacrylate unit in acrylic type triblock copolymer (I-9) was calculated | required by < ¹ > H-NMR measurement mentioned above.

<< Production Example 10 >> [Production of Acrylic Triblock Copolymer (I-10)]
(1) After adding a three-way cock to a 2 L three-necked flask and displacing the inside with nitrogen, while stirring at room temperature, 899 g of toluene and 63.4 g of 1,2-dimethoxyethane are added, followed by isobutyl bis (2, 2, 39.4 g of a toluene solution containing 19.8 mmol of 6-di-t-butyl-4-methylphenoxy) aluminum was added, and 4.65 g of a cyclohexane solution of sec-butyllithium containing 7.92 mmol of sec-butyllithium was further added added.
(2) Subsequently, 25.9 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to -30.degree. C., 373 g of n-butyl acrylate was dropped over 2 hours, and after completion of dropping, the solution was stirred at -30.degree. C. for 5 minutes.
(4) Furthermore, 6.48 g of methyl methacrylate was added to this, and it stirred at room temperature overnight.
(5) After the polymerization reaction was stopped by adding 16 g of methanol, the resulting reaction solution was poured into 15 kg of methanol to precipitate a precipitate. Thereafter, the precipitate was recovered and dried to obtain 385 g of an acrylic triblock copolymer (I-10). The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the obtained acrylic triblock copolymer (I-10) were determined by GPC measurement of the above method. Moreover, content of the polymer block which consists of a methyl methacrylate unit in acrylic type triblock copolymer (I-10) was calculated | required by < ¹ > H-NMR measurement mentioned above.

<< Production Example 11 >> [Production of Acrylic Diblock Copolymer (II-1)]
(1) After adding a three-way cock to a 2 L three-necked flask and displacing the inside with nitrogen, 903 g of toluene and 58.3 g of 1,2-dimethoxyethane are added while stirring at room temperature, followed by addition of isobutyl bis (2, 2, 36.2 g of a toluene solution containing 18.2 mmol of 6-di-t-butyl-4-methylphenoxy) aluminum was added, and 4.27 g of a cyclohexane solution of sec-butyllithium containing 7.28 mmol of sec-butyllithium was further added. added.
(2) Subsequently, 26.8 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to -30.degree. C., 378 g of n-butyl acrylate was dropped over 2 hours, and after completion of dropping, the solution was stirred at -30.degree. C. for 5 minutes.
(4) After the polymerization reaction was stopped by adding 15 g of methanol, the resulting reaction solution was poured into 15 kg of methanol to precipitate a precipitate. Thereafter, the precipitate was recovered and dried to obtain 380 g of an acrylic diblock copolymer (II-1). The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the obtained acrylic diblock copolymer (II-1) were determined by GPC measurement of the above method. Moreover, content of the polymer block which consists of a methyl methacrylate unit in acrylic diblock copolymer (II-1) was calculated | required by < ¹ > H-NMR measurement mentioned above.

  Weight average molecular weight (Mw) and molecular weight distribution of the acrylic triblock copolymers (I-1) to (I-10) and the acrylic diblock copolymer (II-1) obtained in the above Production Examples 1 to 11 The contents of (Mw / Mn), block structure, and each polymer block are shown in Table 1.

In Examples and Comparative Examples, the following were used as a tackifying resin and a plasticizer.
Tackifying resin:
-Brand name "Ysertack 311" made by Euro Yser, rosin ester, softening point 88 ° C
· Brand name "Foral 85" made by Pinova, hydrogenated rosin ester, softening point 85 ° C
· Brand name "Foral AX" made by Pinova, rosin acid, softening point 66 ° C
· Brand name "Clearon K4100" manufactured by Yasuhara Chemical Co., Ltd., hydrogenated aromatic modified terpene resin, softening point 100 ° C
· Brand name "YS polyster T160" manufactured by Yasuhara Chemical Co., Ltd., terpene phenol resin, softening point 160 ° C
· Brand name "YS resin SX100" made by Yasuhara Chemical Co., Ltd., aromatic hydrocarbon resin, softening point 100 ° C
· Brand name "Arkon M100" manufactured by Arakawa Chemical Industries, Ltd., hydrogenated petroleum resin, softening point 100 ° C
Plasticizer:
· Brand name: "DOP", manufactured by Shin Nippon Rika Co., Ltd., bis (2-ethylhexyl) phthalate · Brand name: "ATBC", manufactured by Asahi Kasei Finechem Co., Ltd., tributyl acetyl citrate Name "Acronal LR8820" made by BASF, acrylic oligomer

«Examples 1 to 23, Comparative Examples 1 to 5»
The acrylic triblock copolymers (I-1) to (I-10) and the acrylic diblock copolymer (II-1) obtained in the above Production Examples 1 to 11, and the tackifying resin and the plasticizer It melt | dissolved in toluene by the mass ratio shown to the following Tables 2-3, and produced the toluene solution containing the adhesive composition with a density | concentration of 30 mass%. This is coated on a polyethylene terephthalate film (Toyobo Co., Ltd. E5000, thickness 50 μm) by a coater so that the thickness of the tacky-adhesive layer after drying becomes 25 μm, and then the film is heated at 100 ° C. for 3 minutes. And heat-treated to prepare a tacky adhesive tape. In the evaluation of the produced pressure-sensitive adhesive tape, when it is necessary to stick to the adherend, evaluation was carried out by sticking a 2 kg roller twice by reciprocating at a speed of 10 mm / sec. The results are shown in Tables 2-3 below.

From the results of Table 2 and Table 3, it can be seen that the adhesive composition of the present invention has good coatability, and the adhesive tape obtained therefrom is excellent in heat resistance retention and tack. On the other hand, according to the results of Table 3, in Comparative Example 1 consisting only of the acrylic triblock copolymer, the viscosity of the composition is high, and the coatability and the tackiness are poor. The adhesive composition comprising a composition outside the scope of the present invention as in Comparative Example 2 is excellent in coatability but inferior in heat-resistant holding power and tack. In Comparative Examples 3 to 5 using an acrylic triblock copolymer having a molecular specification outside the scope of the present invention, the resulting pressure-sensitive adhesive composition becomes inferior in heat resistance retention or coating property and tackiness. .
From the above, it can be seen that the adhesive composition of the present invention has good coatability, and exhibits excellent performance in heat retention and tack.

Claims (3)

(I) having two polymer blocks (A1) and (A2) consisting of methacrylic acid ester units and one polymer block (B) consisting of acrylic acid ester units, (A1)-(B)-(A) A2) Acrylic tri having a block structure, a weight average molecular weight (Mw) of 300,000 to 450,000, and a total content of polymer blocks (A1) and (A2) of 35% by mass or less A pressure-sensitive adhesive composition containing 100 parts by mass of the block copolymer (I) and (ii) 1 to 190 parts by mass of a tackifying resin. (I) 100 parts by mass of the acrylic triblock copolymer (I),
The adhesive composition according to claim 1, comprising (ii) 1 to 190 parts by mass of a tackifier resin, and (iii) 80 parts by mass or less of a plasticizer. It has one polymer block (C) consisting of methacrylic acid ester units and one polymer block (D) consisting of acrylic acid ester units, and has a weight average molecular weight (Mw) of 10,000 to 120,000 And further containing an acrylic diblock copolymer (II) having a polymer block (C) content of 25% by mass or less.
The pressure-sensitive adhesive composition according to claim 1.