JP2004162042A - Viscous/adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a viscous/adhesive composition excellent in cohesive force (e.g., retention at 80°C) under a high temperature condition. <P>SOLUTION: This viscous/adhesive composition comprises at least one kind of addition polymerization-based block copolymer (I) selected from block copolymers or their hydrogenated derivatives having one or more polymer blocks A mainly comprising an aromatic vinyl compound containing at least ≥1 mass% structural unit derived from an alkylstyrene in which at least one 1-8C alkyl group is bonded to the benzene ring and one or more polymer blocks B mainly comprising a diene compound unit, and at least the polymer block A is crosslinkable by active rays. The composition is crosslinked by the active rays. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a pressure-sensitive adhesive / adhesive composition, and more particularly to a pressure-sensitive adhesive / adhesive composition having excellent holding power under high-temperature conditions and suitable for hot-melt pressure-sensitive adhesive / adhesive applications.

  As base polymers for hot melt adhesives and adhesives, various polymers such as ethylene-vinyl acetate copolymer, styrene-conjugated diene block copolymer and hydrogenated product thereof, ethylene-α-olefin copolymer, polyester resin and the like can be used. Coalescence is used. In particular, the styrene-conjugated diene block copolymer has a long open time and a relatively good balance between adhesiveness and holding power, and thus is suitably used as an adhesive for disposable sanitary materials and an adhesive for surface protective films. Have been. For example, an adhesive composition using a linear block copolymer such as a polystyrene-polybutadiene-polystyrene block copolymer or a polystyrene-polyisoprene-polystyrene block copolymer has been disclosed (see Patent Document 1). Further, a hot-melt (hot melt) pressure-sensitive adhesive composition using a branched block copolymer of (polystyrene-polybutadiene) nX is also disclosed (see Patent Document 2).

JP-B-45-41518 JP-B-56-49958

  However, these tacky / adhesives based on a block copolymer composed of styrene and a conjugated diene have a glass transition temperature (Tg) of about 100 ° C. of a polystyrene block of the base copolymer. Therefore, the cohesive strength (holding force) of the tacky / adhesive under a high temperature condition has been reduced, and there is an urgent need for improvement.

  Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a tacky / adhesive composition excellent in cohesive force (holding force) under high temperature conditions.

According to the present invention, the above object is
[1] At least 1% by mass of an alkylstyrene-derived structural unit (a) in which at least one of the alkyl groups having 1 to 8 carbon atoms is bonded to a benzene ring (hereinafter may be abbreviated as structural unit (a)). Has at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound unit, and at least the polymer block A portion is crosslinked by active energy rays. A viscous / adhesive comprising at least one addition-polymerized block copolymer (I) selected from a possible block copolymer and a hydrogenated product thereof, and cross-linkable by active energy rays. Composition;
[2] The photopolymerization initiator (II) is contained in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the addition-polymerized block copolymer (I), and crosslinking is performed by irradiating ultraviolet rays as active energy rays. A viscous / adhesive composition according to [1];
[3] The viscous / adhesive composition according to [1], wherein crosslinking is performed by irradiating an electron beam as an active energy ray;
[4] The tacky / adhesive composition according to any one of [1] to [3], further comprising a tackifier resin (III) and / or a softener (IV);
[5] The adhesive / adhesive composition according to any one of [1] to [4], wherein the structural unit (a) comprises a p-methylstyrene unit;
[6] It is achieved by providing a tacky / adhesive film comprising the tacky / adhesive composition of any one of [1] to [5].

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive composition excellent in cohesive force (holding force) at high temperature under high temperature conditions is obtained.

Hereinafter, the present invention will be described in detail.
The addition-polymerized block copolymer (I), which is an essential component of the adhesive composition of the present invention, comprises an alkylstyrene-derived structural unit having at least one alkyl group having 1 to 8 carbon atoms bonded to a benzene ring ( a) at least one polymer block A mainly composed of an aromatic vinyl compound having at least 1% by mass and at least one polymer block B mainly composed of a conjugated diene compound unit; Part A is at least one type of addition-polymerized block copolymer selected from a block copolymer crosslinkable by an active energy ray and a hydrogenated product thereof.

  In the polymer block A, examples of the alkylstyrene constituting the structural unit (a) include o-alkylstyrene, m-alkylstyrene, p-alkylstyrene, and 2,4 in which the alkyl group has 1 to 8 carbon atoms. -Dialkylstyrene, 3,5-dialkylstyrene, 2,4,6-trialkylstyrene, halogenated alkylstyrene in which one or more of the hydrogen atoms of the alkyl group in the above-mentioned alkylstyrenes is substituted with a halogen atom And the like. More specifically, examples of the alkylstyrene constituting the structural unit (a) include o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 3,5-dimethylstyrene, , 4,6-trimethylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, 2,4-diethylstyrene, 3,5-diethylstyrene, 2,4,6-triethylstyrene, o-propylstyrene M-propylstyrene, p-propylstyrene, 2,4-dipropylstyrene, 3,5-dipropylstyrene, 2,4,6-tripropylstyrene, 2-methyl-4-ethylstyrene, 3-methyl- 5-ethylstyrene, o-chloromethylstyrene, m-chloromethylstyrene, p-chloromethylstyrene, 2,4- Chloro (methyl) styrene, 3,5-bis (chloromethyl) styrene, 2,4,6-tri (chloromethyl) styrene, o-dichloromethylstyrene, m-dichloromethylstyrene, p-dichloromethylstyrene, etc. Can be mentioned.

  The polymer block A can have, as the structural unit (a), a unit composed of one or more of the above-described alkylstyrenes and halogenated alkylstyrenes. Among these, as the structural unit (a), a structural unit based on p-methylstyrene is preferable from the viewpoint of easy availability and excellent crosslinking reactivity.

  Examples of the aromatic vinyl compound unit other than the structural unit (a) include styrene, α-methylstyrene, β-methylstyrene, monofluorostyrene, difluorostyrene, monochlorostyrene, dichlorostyrene, methoxystyrene, vinylnaphthalene, and vinyl. Units composed of anthracene, indene, acetonaphthylene and the like can be mentioned, and among these, units composed of styrene and α-methylstyrene are preferred.

  In the addition-polymerized block copolymer (I), the polymer block A corresponds to a hard segment, and the alkyl group bonded to the benzene ring in the structural unit (a) undergoes a static crosslinking reaction by irradiation with active energy rays. Has the effect of introducing crosslinks into the hard segment comprising the polymer block A.

  The ratio of the structural unit (a) in the polymer block A is 1% by mass or more, preferably 10% by mass or more, more preferably 40% by mass or more, based on the mass of the polymer block A, Further, all units may be composed of the structural unit (a). When the proportion of the structural unit (a) is less than 1% by mass, crosslinking is difficult to be introduced into the polymer block A, and the obtained adhesive / adhesive composition has a sufficient cohesive force especially at a high temperature (for example, at 80 ° C). ) Tends to be difficult to develop. The bonding form between the structural unit (a) and the other aromatic vinyl compound unit in the polymer block A may be any form such as random, block, or tapered.

  The content of the polymer block A in the addition-polymerized block copolymer (I) is preferably from 10 to 40% by mass. If the amount is less than 10% by mass, the crosslinking effect does not sufficiently appear, and a sufficient cohesive force (holding force) tends to be hardly developed. On the other hand, if it is more than 40% by mass, it tends to be difficult to obtain tackiness of the adhesive / adhesive composition.

  The polymer block A in the addition-polymerized block copolymer (I) contains, as necessary, a structural unit composed of another polymerizable monomer together with a structural unit composed of an aromatic vinyl compound containing the structural unit (a). It may have a small amount, and in that case, the ratio of the structural unit composed of another polymerizable monomer is preferably 30% by mass or less based on the mass of the polymer block A, and is preferably 10% by mass or less. More preferably, there is. In this case, examples of other polymerizable monomers include 1-butene, pentene, hexene, butadiene, isoprene, and methyl vinyl ether.

  The addition-polymerized block copolymer (I) used in the present invention is, in addition to the polymer block A composed of an aromatic vinyl compound unit containing the structural unit (a), an aromatic block containing no structural unit (a). It may have a polymer block composed of a vinyl compound unit.

  On the other hand, examples of the conjugated diene compound constituting the polymer block B mainly composed of a conjugated diene compound unit in the addition polymerization type block copolymer (I) include butadiene, isoprene, 2,3-dimethyl-1,3-butadiene. , 1,3-pentadiene, 1,3-hexadiene and the like. The polymer block B may be composed of only one type of these compounds, or may be composed of two or more types. Among them, butadiene, isoprene, or a mixture of butadiene and isoprene is preferred. preferable. The type and content of the microstructure of the polymer block B are not particularly limited. When two or more conjugated diene compounds are used in combination, their bonding forms can be random, block, tapered, or a combination of two or more thereof.

  The polymer block B may have a small amount of a structural unit composed of another polymerizable monomer together with a structural unit composed of a conjugated diene compound, if necessary. In this case, the ratio of the other polymerizable monomer is preferably 30% by mass or less, and more preferably 10% by mass, based on the total mass of the polymer blocks B constituting the addition-polymerized block copolymer (I). It is more preferred that: In this case, examples of the other polymerizable monomer include styrene, α-methylstyrene, and the above-mentioned alkylstyrene (preferably p-methylstyrene) constituting the structural unit (a).

  Among them, the polymer block B is a polyisoprene block composed of isoprene units or a hydrogenated polyisoprene block obtained by partially or entirely hydrogenating carbon-carbon double bonds based on the isoprene units; a polybutadiene block composed of butadiene units Or a hydrogenated polybutadiene block in which part or all of the carbon-carbon double bond based on the butadiene unit is hydrogenated; or a copolymer block composed of a mixture of isoprene and butadiene composed of an isoprene unit and a butadiene unit, or the isoprene unit It is preferable that the carbon-carbon double bond based on butadiene units is a copolymer block in which part or all of the carbon-carbon double bond is hydrogenated.

  As long as the polymer block A and the polymer block B are bonded, the type of the addition-polymerized block copolymer (I) is not limited, and may be linear, branched, radial, or a combination thereof. Any combination of two or more combinations may be used. Among them, the bonding form of the polymer block A and the polymer block B is preferably linear, for example, when the polymer block A is represented by A and the polymer block B is represented by B. A triblock copolymer represented by ABA, a tetrablock copolymer represented by ABAB, a pentablock copolymer represented by ABABA, etc. Can be mentioned. Among them, the triblock copolymer (ABA) is preferably used from the viewpoint of easiness of production and flexibility of the addition polymerization type block copolymer (I).

  The number average molecular weight of the addition polymerization type block copolymer (I) is not particularly limited, but is preferably in the range of 30,000 to 1,000,000, and more preferably in the range of 40,000 to 300,000. In addition, the number average molecular weight here means the number average molecular weight in terms of polystyrene obtained by gel permeation chromatography (GPC).

The addition-polymerized block copolymer (I) can be produced, for example, by the following known anionic polymerization method. That is, using an alkyllithium compound or the like as an initiator, an alkylstyrene constituting the structural unit (a) or an alkylstyrene constituting the structural unit (a) in an organic solvent inert to a polymerization reaction such as n-hexane or cyclohexane. And a conjugated diene compound are sequentially polymerized to form a block copolymer (ie, an unhydrogenated addition-polymerized block copolymer (I)).
Further, the obtained block copolymer can be further hydrogenated as necessary. In the hydrogenation reaction, for example, the block copolymer is prepared by mixing a metal such as Raney nickel; Pt, Pd, Ru, Rh, and Ni with a carrier such as carbon, alumina, and diatomaceous earth in a saturated hydrocarbon solvent such as cyclohexane. Heterogeneous catalyst supported on Ziegler catalyst comprising a combination of an organic metal compound comprising a Group 9 or 10 metal such as cobalt or nickel and an organic aluminum compound such as triethylaluminum or triisobutylaluminum or an organic lithium compound A hydrogenation catalyst such as a metallocene catalyst comprising a combination of a bis (cyclopentadienyl) compound of a transition metal such as titanium, zirconium, hafnium and an organometallic compound such as lithium, sodium, potassium, aluminum, zinc or magnesium; In the presence, usually The reaction can be carried out at a reaction temperature of 20 to 100 ° C. and a hydrogen pressure of 0.1 to 10 MPa, and the hydrogenated product of the block copolymer (ie, the hydrogenated addition polymerization block) Copolymer (I)) can be obtained.

The hydrogenation rate can be appropriately adjusted according to the physical properties required for the adhesive / adhesive composition of the present invention. However, when importance is placed on heat resistance, weather resistance and ozone resistance, the addition polymerization type block may be used. It is preferable that 70% or more of the carbon-carbon double bond based on the conjugated diene compound unit of the polymer block B constituting the polymer (I) is hydrogenated, more preferably 85% or more, and 95% or more. % Or more is more preferably hydrogenated.
The hydrogenation rate of the carbon-carbon double bond based on the conjugated diene compound unit of the polymer block B is determined by measuring the polymer before and after the hydrogenation reaction by measuring means such as iodine titration, infrared spectrophotometer, and nuclear magnetic resonance. The amount of the carbon-carbon double bond in the block B is measured and can be calculated from the measured value.

The active energy ray used for crosslinking the adhesive / adhesive composition of the present invention includes an electromagnetic wave, a particle beam, and a combination thereof. The electromagnetic wave includes ultraviolet (UV), visible light, infrared, γ-ray, X-ray, and the like, and the particle beam includes electron beam (EB) and α-ray. Among these, it is preferable to use an ultraviolet ray (UV) or an electron beam (EB) as the active energy ray.
These active energy rays can be irradiated using a known device. In the case of an electron beam (EB), the accelerating voltage is suitably in the range of 0.1 to 10 MeV, and the irradiation dose is suitably in the range of 1 to 500 kGy. In the case of ultraviolet rays (UV), a lamp having a radiation wavelength of 200 nm to 450 nm can be suitably used as the radiation source. Examples of the radiation source include an electron beam (EB), for example, a tungsten filament, and an ultraviolet ray (UV), for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultraviolet mercury lamp, a carbon arc lamp, a xenon lamp, a zirconium lamp, and the like. Is mentioned.

  In the adhesive / adhesive composition of the present invention, when crosslinking is carried out by ultraviolet rays (UV) as active energy rays, it is preferable to contain a photopolymerization initiator (II). Examples of the photopolymerization initiator (II) include benzophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, α-methylol benzoin, α-methylol benzoin methyl ether, α-methoxy benzoin methyl ether, benzoin phenyl ether, Examples thereof include α-t-butylbenzoin, but are not limited thereto. These may be used alone or in combination of two or more.

  When the photopolymerization initiator (II) is contained in the adhesive / adhesive composition of the present invention, the content is 0.1 to 5 parts by mass with respect to 100 parts by mass of the addition-polymerized block copolymer (I). Is preferably within the range. When the content of the photopolymerization initiator (II) is less than 0.1 part by mass, it becomes difficult to form a sufficient crosslink even by irradiating ultraviolet rays (UV). On the other hand, when the content is more than 5 parts by mass, Since the transmittance of ultraviolet rays (UV) is reduced, and the exposure sensitivity is rather reduced, sufficient crosslinking is less likely to be formed.

  The tackifier / adhesive composition of the present invention may contain a tackifier resin (III) as necessary. As the tackifying resin (III), those conventionally used as a resin for imparting tackiness for a tacky / adhesive can be used without particular limitation. Examples thereof include a rosin resin, a terpene resin, and an aliphatic resin. Petroleum resins, aromatic petroleum resins, alicyclic petroleum resins, cumarone / indene resins, styrene resins, alkylphenol resins, xylene resins, and the like. One of these may be used alone, or two or more thereof may be used. May be used in combination.

  When the tackifier resin (III) is contained, the amount thereof is not particularly limited, but is usually in the range of 40 to 1,000 parts by mass with respect to 100 parts by mass of the addition-polymerized block copolymer (I). Is preferred, and the content is more preferably in the range of 100 to 500 parts by mass. One type of tackifier resin (III) may be used alone, or two or more types may be used in combination.

  The adhesive / adhesive composition of the present invention may contain a softener (IV) as needed. Examples of the softener (IV) include non-aromatic petroleum softeners such as paraffinic and naphthenic process oils, and vegetable oil softeners such as vegetable oils such as paraffin, peanut oil, and rosin. Among these, non-aromatic petroleum softeners are preferred. As the softener (IV), one type may be used alone, or two or more types may be used in combination.

  When the softening agent (IV) is contained, the amount thereof is not particularly limited, but is usually in the range of 10 to 1000 parts by mass with respect to 100 parts by mass of the addition-polymerized block copolymer (I). Preferably, it is in the range of 20 to 500 parts by mass, more preferably 50 to 300 parts by mass.

  A stabilizer can be added to the adhesive / adhesive composition of the present invention, if necessary. Examples of the stabilizer include 2,6-di-tert-butyl-p-cresol, pentaerythryltetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5- Trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, triethylene glycol -Bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 2,4-bis (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino ) -1,3,5-Triazine, 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N -Hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrodinamamide), 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl ester, tris (3,5-di-tert-butyl-4) -Hydroxybenzyl) isocyanurate, 3,9-bis {2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} -2,4. Phenolic stabilizers such as 8,10-tetraoxaspiro [5.5] undecane; pentaerythrityltetrakis (3-laurylthiopropionate), distearyl 3,3'-thiodipropionate, dilauryl 3,3 Sulfur-based stabilizers such as' -thiodipropionate and dimyristyl 3,3'-thiodipropionate; Nyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, distearylpentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, etc. And phosphorus-based stabilizers. One of these stabilizers may be used alone, or two or more of them may be used in combination.

  In addition, for the purpose of modifying the adhesive / adhesive composition of the present invention, other additives such as an antistatic agent, a flame retardant, a pigment, and a dye are added within a range that does not impair the purpose of the present invention. be able to.

  In addition, in the pressure-sensitive adhesive composition of the present invention, from the viewpoint of further improving heat resistance, as long as the properties are not impaired, as a reinforcing resin, polystyrene, polyethylene, polypropylene, ethylene-propylene copolymer, In addition to the ethylene-butene copolymer and the ethylene-vinyl acetate copolymer, a thermoplastic polyester resin, a polyamide resin, a polyphenylene ether resin, or the like having a relatively low molecular weight can be blended.

  Furthermore, in the adhesive / adhesive composition of the present invention, other polymers, such as natural rubber, synthetic polyisoprene rubber, and liquid polyisoprene rubber, for the purpose of improving fluidity and the like, as long as the properties are not impaired. And hydrogenated products thereof, polybutadiene rubber, liquid polybutadiene rubber and hydrogenated products thereof, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, acrylic rubber, isoprene-isobutylene rubber, rubber such as acrylonitrile-butadiene rubber; or polystyrene- A styrene-based elastomer such as a polyisoprene-polystyrene block copolymer or a polystyrene-polybutadiene-polystyrene block copolymer, or a hydrogenated styrene-based elastomer that is a hydrogenated product thereof may be used as a mixture.

  The viscosity-adhesive composition of the present invention may further contain an inorganic filler as long as its properties are not impaired. Specific examples of such an inorganic filler include talc, calcium carbonate, silica, glass fiber, carbon fiber, mica, kaolin, titanium oxide and the like.

  The method for preparing the adhesive / adhesive composition of the present invention can employ a usual method, for example, a general tank-type mixer, a high-speed stirrer, a closed kneader, an internal mixer, a single-screw extruder, a twin-screw extruder, and the like If necessary, in an atmosphere of nitrogen gas, if necessary, usually in the range of 80 ° C. to 230 ° C., the above-mentioned addition-polymerized block copolymer (I) and, if necessary, It can be prepared by melt-kneading the polymerization initiator (II), the tackifier resin (III), the softener (IV), and other optional components. The obtained adhesive / adhesive composition of the present invention can be in an appropriate form depending on its use, use mode, etc., for example, block, granular, flake, pellet, rod, film, In the form of a sheet or the like, it can be used for various adhesive applications, various kinds of adhesive products, and the like.

  Further, the adhesive composition of the present invention may be, depending on its use, an aliphatic hydrocarbon such as heptane, isopentane, n-hexane, and cyclohexane; an aromatic hydrocarbon such as benzene, xylene, toluene, and ethylbenzene; Usually, a solution-type viscous / adhesive can be prepared by dissolving the solid content so as to have a concentration of 5% to 70%.

  The adhesive / adhesive composition of the present invention can be used for adhesive / adhesive use of various materials similarly to conventional hot melt type adhesives and pressure-sensitive adhesives, and the application is not particularly limited. For example, it can be used for sticking and bonding plastic films and sheets such as polyethylene, polypropylene, and polyester, paper, wood, textiles, metal foil, and leather. More specifically, the adhesive / adhesive composition of the present invention is used for packaging such as bag making, sealing small boxes or cardboard, picking up labels, manufacturing aluminum foil cans, etc .; bookbinding; ; Manufacture of textile products such as shoes, carpet backings and binders for nonwoven fabrics; Manufacture of various sanitary materials such as disposable diapers and sanitary napkins; Adhesive tape for packaging; Electrical insulating tapes and films; Adhesive for surface protection of various articles Tapes and adhesive sheets; various adhesive films and adhesive sheets used in the semiconductor wafer manufacturing process; binding and fixing pipes; various building materials such as window frames; sealing materials around automotive lamps and instrument panels; and adhesives for labels. be able to.

  When the adhesive / adhesive composition of the present invention is used as an application of a hot melt adhesive, the adhesive / adhesive composition of the present invention is applied using a hot melt adhesive applicator similar to the conventional one. Bonding can be performed by irradiating active energy rays in a state where the adherends are adhered to each other by being heated and melted, and the adherends are adhered to each other (compressed).

  When the pressure-sensitive adhesive composition of the present invention is used as a hot-melt type pressure-sensitive adhesive (or pressure-sensitive adhesive), the pressure-sensitive adhesive composition of the present invention is heated and melted. Then, a layer of a pressure-sensitive adhesive (or pressure-sensitive adhesive) is formed on the base material by coating on one or both sides of a base material such as paper, fabric, plastic film, sheet, or metal foil, and the active energy ray is formed. By irradiating, a sticky / adhesive film, a sticky / adhesive sheet, and other sticky / adhesive products can be manufactured.

  In both cases where the adhesive / adhesive composition of the present invention is a hot melt type adhesive and a hot melt type pressure sensitive adhesive (or pressure sensitive adhesive), The adhesive composition can usually be easily melted by heating to a temperature of about 120 ° C. to 200 ° C., and the adhesive work with good workability and the work of manufacturing an adhesive product such as an adhesive film smoothly. It is excellent in cohesive force at high temperature (for example, holding force at 80 ° C.).

  Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples. The evaluation of the performance of the adhesive / adhesive composition was carried out by the following method.

1) Holding force The holding force was evaluated according to JIS Z-0237. That is, a test piece having a width of 25 mm x a length of 25 mm was prepared from the pressure-sensitive adhesive films prepared in Examples and Comparative Examples, bonded to a stainless steel (SUS304) plate, suspended under a load of 1 kg at an environmental temperature of 80 ° C, and dropped. The time was measured.

2) Adhesion The adhesion was evaluated by a 180 ° peel test according to JIS Z-0237. That is, a test piece having a width of 25 mm and a length of 100 mm was prepared from the pressure-sensitive adhesive films prepared in Examples and Comparative Examples, and attached to a sheet of high-density polyethylene having a thickness of 1 mm or a stainless steel (SUS304) plate. The film was peeled at a rate of / min in a direction of 180 °, and the peel strength was measured.

3) Tack Tack was evaluated according to JIS Z-0237. That is, the pressure-sensitive adhesive films prepared in Examples and Comparative Examples were cut into a width of 25 mm and a length of 100 mm to prepare test pieces. The test piece was fixed on a 30 ° inclined face with the adhesive face up. The ball bearing ball was spontaneously rolled at a position 100 mm above the slope of the test piece without giving an initial speed. Within this test piece, within 100 mm, the largest diameter of the spheres stopped by adhesive force (using various spheres whose diameters differ in 1/32 inch units, (Shown) was taken as the ball tack value.

Reference Example 1
In a pressure vessel equipped with a stirrer, 23 kg of cyclohexane and 99 ml of sec-butyllithium (11% by mass, cyclohexane solution) were added, and a mixed solution of p-methylstyrene and styrene (p-methylstyrene / styrene = 2/1) was added to the solution. (Mass ratio)) 467 g was added over 30 minutes and polymerized at 50 ° C. for 30 minutes, then 6380 g of isoprene was added over 60 minutes and polymerized at 50 ° C. for 90 minutes, and a mixed solution of p-methylstyrene and styrene ( 467 g of (p-methylstyrene / styrene = 2/1 (mass ratio)) was added over 30 minutes and polymerized at 50 ° C. for 30 minutes to obtain poly (p-methylstyrene / styrene) -polyisoprene-poly (p-methylstyrene). / Styrene) to obtain a reaction mixture containing a triblock copolymer (hereinafter referred to as block copolymer (I) -1). The number average molecular weight of the obtained block copolymer (I) -1 was 88,500, and the total content of p-methylstyrene and styrene measured by ¹ H-NMR was 18% by mass.
Hydrogenation separately prepared by adding 90 g of nickel octylate (64% by mass, cyclohexane solution) to 460 g of triisopropylaluminum (20% by mass, cyclohexane solution) to the reaction mixture containing the block copolymer (I) -1. A catalyst was added thereto, and a hydrogenation reaction was carried out at 80 ° C. under a hydrogen atmosphere of 1 MPa to obtain a poly (p-methylstyrene / styrene) -polyisoprene-poly (p-methylstyrene / styrene) triblock copolymer. A hydrogenated product (hereinafter, referred to as a block copolymer (I) -2) was obtained. The number average molecular weight of the obtained block copolymer (I) -2 was 95,000, and the content and hydrogenation ratio of p-methylstyrene and styrene, each measured by ¹ H-NMR, were 17% by mass, respectively. 97%.

Reference Example 2
In a pressure vessel equipped with a stirrer, 23 kg of cyclohexane and 33 ml of sec-butyllithium (11% by mass, cyclohexane solution) were added, and a mixed solution of p-methylstyrene and styrene (p-methylstyrene / styrene = 2/1) was added to this solution. (Mass ratio)) 467 g was added over 30 minutes and polymerized at 50 ° C. for 30 minutes, then 6380 g of isoprene was added over 60 minutes and polymerized at 50 ° C. for 90 minutes, and a mixed solution of p-methylstyrene and styrene ( 467 g of (p-methylstyrene / styrene = 2/1 (mass ratio)) was added over 30 minutes and polymerized at 50 ° C. for 30 minutes to obtain poly (p-methylstyrene / styrene) -polyisoprene-poly (p-methylstyrene). (Styrene)) A reaction mixture containing a triblock copolymer (hereinafter, this is referred to as block copolymer (I) -3) was obtained. The number average molecular weight of the obtained block copolymer (I) -3 was 275000, and the total content of p-methylstyrene and styrene measured by ¹ H-NMR was 18% by mass.
Hydrogenation separately prepared by adding 90 g of nickel octylate (64% by mass, cyclohexane solution) to 460 g of triisopropylaluminum (20% by mass, cyclohexane solution) to the reaction mixture containing the block copolymer (I) -3. A catalyst was added thereto, and a hydrogenation reaction was carried out at 80 ° C. under a hydrogen atmosphere of 1 MPa to obtain a poly (p-methylstyrene / styrene) -polyisoprene-poly (p-methylstyrene / styrene) triblock copolymer. A hydrogenated product (hereinafter, referred to as a block copolymer (I) -4) was obtained. The number average molecular weight of the obtained block copolymer (I) -4 was 285,000, and the content of p-methylstyrene and styrene combined and the hydrogenation rate measured by ¹ H-NMR were 17% by mass, respectively. 97%.

Reference Example 3
In a pressure vessel equipped with a stirrer, 23 kg of cyclohexane and 99 ml of sec-butyllithium (11% by mass, cyclohexane solution) were added, 467 g of styrene was added to this solution over 30 minutes, polymerization was carried out at 50 ° C. for 30 minutes, and then 6380 g of isoprene Was added over 60 minutes and polymerized at 50 ° C. for 90 minutes. Further, 467 g of styrene was added over 30 minutes and polymerized at 50 ° C. for 30 minutes to obtain a polystyrene-polyisoprene-polystyrene triblock copolymer (hereinafter referred to as a block). A reaction mixture containing the copolymer (referred to as copolymer (1)) was obtained. The number average molecular weight of the obtained block copolymer (1) was 88,500, and the styrene content measured by ¹ H-NMR was 18% by mass.
A hydrogenation catalyst prepared separately by adding 90 g of nickel octylate (64% by mass, cyclohexane solution) and 460 g of triisopropylaluminum (20% by mass, cyclohexane solution) to the reaction mixture containing the block copolymer (1) was added. And a hydrogenation reaction was carried out at 80 ° C. in a hydrogen atmosphere of 1 MPa to obtain a hydrogenated product of the above-mentioned polystyrene-polyisoprene-polystyrene triblock copolymer (hereinafter referred to as a block copolymer (2)). Got. The number average molecular weight of the obtained block copolymer (2) was 95,000, and the styrene content and the hydrogenation rate measured by ¹ H-NMR were 17% by mass and 97%, respectively.

Reference example 4
In a pressure vessel with a stirrer, 23 kg of cyclohexane and 33 ml of sec-butyllithium (11% by mass, cyclohexane solution) were added, 467 g of styrene was added to this solution over 30 minutes, polymerization was carried out at 50 ° C. for 30 minutes, and then 6380 g of isoprene Was added over 60 minutes and polymerized at 50 ° C. for 90 minutes. Further, 467 g of styrene was added over 30 minutes and polymerized at 50 ° C. for 30 minutes to obtain a polystyrene-polyisoprene-polystyrene triblock copolymer (hereinafter referred to as a block). (Referred to as copolymer (3)). The number average molecular weight of the obtained block copolymer (3) was 275000, and the styrene content measured by ¹ H-NMR was 18% by mass.
A hydrogenation catalyst separately prepared by adding 460 g of triisopropylaluminum (20 mass%, cyclohexane solution) to 90 g of nickel octylate (64 mass%, cyclohexane solution) was added to the reaction mixture containing the block copolymer (3). And a hydrogenation reaction was carried out at 80 ° C. under a hydrogen atmosphere of 1 MPa to obtain a hydrogenated product of the above-mentioned polystyrene-polyisoprene-polystyrene triblock copolymer (hereinafter referred to as a block copolymer (4)). Got. The number average molecular weight of the obtained block copolymer (4) was 285,000, and the styrene content and the hydrogenation rate measured by ¹ H-NMR were 17% by mass and 97%, respectively.

<Examples 1 to 8>
The block copolymer (I) -2, the block copolymer (I) -4, and the tackifier resin ("Alcon P-100" (trade name, manufactured by Arakawa Chemical Industries, Ltd .; alicyclic group) obtained in Reference Examples Petroleum resin)), softener (“Diana Process PW-380” (trade name, manufactured by Idemitsu Kosan Co., Ltd .; paraffin-based process oil)), benzophenone as a photopolymerization initiator, and Irganox 1076 (trade name, Ciba Specialty) as an antioxidant Tea Chemicals Co .; hindered phenolic antioxidant) was added to a kneader heated to 160 ° C. in a formulation (all parts by mass) shown in Table 1 and melted and mixed for 30 minutes to prepare a tacky / adhesive composition. Using a 40 μm coater, the obtained tacky / adhesive composition was applied to a polyethylene terephthalate film (“Lumirror S10” (trade name, manufactured by Toray Industries, Inc.), Perform a coating on a 50 [mu] m), to prepare a pressure-sensitive adhesive film was irradiated ultraviolet rays of 30 mW / cm ² a (emission wavelength 200 to 450 nm) 30 seconds or 60 seconds to the adhesive surface (see Table 1). The resulting adhesive film The above-mentioned performance evaluation was performed by using Table 1. The results are shown in Table 1.

<Comparative Examples 1 to 8>
Examples 1 to 8 were carried out except that the block copolymer (2) and the block copolymer (4) were used instead of the block copolymer (I) -2 and the block copolymer (I) -4. In the same manner as in Examples 1 to 8, a viscous / adhesive composition was prepared and a pressure-sensitive adhesive film was prepared. Table 2 shows the results.

<Comparative Examples 9 to 12>
In Examples 5 and 7 and Comparative Examples 5 and 7, a pressure-sensitive adhesive film was prepared from the adhesive / adhesive composition in the same manner as in Examples 5 and 7 and Comparative Examples 5 and 7, except that ultraviolet light was not irradiated. The performance evaluation described above was performed. Table 3 shows the results.

When Examples 1 to 8 and Comparative Examples 1 to 8 are compared, the adhesive / adhesive composition containing the block copolymer (I) -2 or (I) -4 shows that the block copolymer (2) Alternatively, it is found that the cohesive force (holding force) at a high temperature (80 ° C.) is superior to that of the adhesive / adhesive composition containing the block copolymer (4).
Further, from Comparative Examples 9 to 12, it is found that the cohesive force (holding force) at a high temperature (80 ° C.) of the viscous / adhesive composition of the present invention is significantly improved by UV irradiation.

The adhesive / adhesive composition obtained by the method of the present invention can be utilized as a material or adhesive / adhesive for various adhesive / adhesive films by utilizing their excellent properties.

Claims (6)

At least one polymer block A mainly composed of an aromatic vinyl compound having at least 1% by mass or more of an alkylstyrene-derived structural unit (a) in which at least one of the alkyl groups having 1 to 8 carbon atoms is bonded to a benzene ring; A block copolymer having at least one polymer block B mainly composed of a conjugated diene compound unit, at least a portion of the polymer block A being crosslinkable by an active energy ray, and at least one hydrogenated product thereof. A viscous / adhesive composition comprising an addition-polymerized block copolymer (I) and being crosslinked by active energy rays. The photopolymerization initiator (II) is contained in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the addition-polymerized block copolymer (I) according to claim 1, and irradiated with ultraviolet rays as active energy rays. 2. The adhesive / adhesive composition according to claim 1, wherein crosslinking is carried out by: The adhesive / adhesive composition according to claim 1, wherein crosslinking is performed by irradiating an electron beam as an active energy ray. The tacky / adhesive composition according to any one of claims 1 to 3, further comprising a tackifier resin (III) and / or a softener (IV). The alkylstyrene-derived structural unit (a) in which at least one of the alkyl groups having 1 to 8 carbon atoms is bonded to a benzene ring comprises a p-methylstyrene unit. 6. The adhesive / adhesive composition according to claim 1. A pressure-sensitive adhesive / adhesive film comprising the pressure-sensitive adhesive / adhesive composition according to claim 1.