JP2008111105A - Cation-polymerizable adhesive for plastic substrate, laminated body and polarizing plate using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cation-polymerizable adhesive for plastic substrate excellent in initial adhesion, quick curability in lamination of various plastic substrates such as an optical film, a food packaging film and films for other industrial materials, etc., and to provide a laminate and a polarizing plate using the same. <P>SOLUTION: The invention relates to the cation-polymerizable adhesive for plastic substrate comprising (A) a multi-branched polyol having 10 or more hydroxy groups, (B) an alicyclic epoxy compound having two or more alicyclic epoxy groups, and (C) an acid generator. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a cationic polymerizable adhesive for plastic substrates that can be used for laminating plastic substrates such as optical films, food packaging films, and other industrial material films, and a laminate and a polarizing plate using the same. .

As a polarizing plate used for a liquid crystal display, generally, a polarizer made of a polyvinyl alcohol film impregnated with a dichroic material such as iodine is added to a transparent film made of triacetyl cellulose or a thermoplastic saturated norbornene resin. A laminate of protective films is known.
As an adhesive used for laminating the polarizer and the protective film, from the viewpoint of improving the production efficiency of the polarizing plate, an adhesive having excellent adhesion to a substrate and capable of rapid curing is used in industry. Demanded by the world.

As the adhesive, for example, it is proposed to use a urethane prepolymer obtained by reacting a compound having two or more isocyanate groups in a molecule with a compound having active hydrogen that reacts with an isocyanate group in one molecule. (For example, refer to Patent Document 1).
However, the adhesive has a problem of low production efficiency because it takes time to cure.

As the adhesive, for example, it has been proposed to use an isocyanate compound having a water-dispersible component in the molecule (see, for example, Patent Document 2).
However, the adhesive does not have sufficient initial adhesive strength at the level required for the application, and has a problem of low production efficiency because it takes time for curing.

As the adhesive, an acrylic resin comprising a solution obtained by dissolving one or more acrylic ester (co) polymers in an organic solvent such as toluene or ethyl acetate, or an aqueous emulsion of these (co) polymers. System adhesives are known (for example, see Patent Document 3).
However, the use of the acrylic resin-based pressure-sensitive adhesive has a problem that it is difficult to improve the production efficiency of a polarizing plate and the like because it requires a step of evaporating an organic solvent or water by heating.

Further, as the adhesive, for example, an aqueous adhesive containing a urethane resin, an oxetane compound, and an epoxy compound has been proposed (see, for example, Patent Document 4).
However, the adhesive has a problem of low production efficiency because it takes time to cure.

As the adhesive, for example, an adhesive mainly composed of an epoxy resin that does not contain an aromatic ring has been proposed (see, for example, Patent Document 5).
However, it was difficult to say that the adhesive had sufficient initial adhesiveness and normal adhesiveness at the level required for the application. Moreover, since the use of the adhesive requires a step of volatilizing water as a solvent, it has a problem that it is difficult to improve the production efficiency of a polarizing plate and the like.

JP-A-7-120617 JP 2003-107245 A Japanese Patent Laid-Open No. 5-212828 JP 2005-181817 A JP 2004-245925 A

The problem to be solved by the present invention is to provide a cationically polymerizable adhesive for a plastic substrate that is excellent in initial adhesion to a plastic substrate, normal adhesion, and has fast curing properties.
Moreover, the subject which this invention tends to solve is providing the laminated body firmly adhere | attached with the said cationic polymerizable adhesive for plastic base materials, and a polarizing plate.

  As a result of diligent studies to solve the above problems, the present inventors have developed a specific multi-branched polyol having 10 or more hydroxyl groups, an alicyclic epoxy compound having 2 or more alicyclic epoxy groups, and an acid. The present invention has been completed by using an adhesive composed of a generator.

That is, the present invention contains a multi-branched polyol (A) having 10 or more hydroxyl groups, an alicyclic epoxy compound (B) having two or more alicyclic epoxy groups, and an acid generator (C). The present invention relates to a cationic polymerizable adhesive for plastic substrates.
In addition, the present invention relates to a laminate and a polarizing plate, wherein two or more plastic substrates are bonded using the cationic polymerizable adhesive for plastic substrates.

  The cationic polymerizable adhesive for plastic substrates according to the present invention exhibits excellent adhesiveness to plastic substrates, and therefore is used as an adhesive for producing laminates of optical films, food packaging films, and other industrial material films. It is extremely effective, and can be suitably used especially for the production of optical parts such as polarizing plates.

Hereinafter, the best mode for carrying out the present invention will be described in detail.
The cationic polymerizable adhesive for plastic substrates of the present invention includes a polyol (A) having 10 or more hydroxyl groups in one molecule and an alicyclic epoxy compound (B) having 2 or more alicyclic epoxy groups. And an acid generator (C).

  First, the polyol (A) having 10 or more hydroxyl groups in one molecule used in the present invention will be described.

  The multi-branched polyol (A) having 10 or more hydroxyl groups used in the present invention has a molecular structure in which the molecular chain is further branched into 2 or more at the point where the molecular chain is branched into 2 or more, and has 10 or more hydroxyl groups. The compound which has.

As the multi-branched polyol (A), a polyester-based dendritic polymer formed by polymerization of a polyalcohol and a hydroxy acid, which is commercially available as a registered trademark BOLTORN from Perstorp, Inc. is used. can do.
BOLTORN H2003 (average number of hydroxyl groups in one molecule 12)
BOLTORN H20 (average number of hydroxyl groups in one molecule: 16)
BOLTORN H30 (average number of hydroxyl groups in one molecule 32)
BOLTORN H40 (average number of hydroxyl groups in one molecule: 64)

  Further, as the multi-branched polyol (A), a multi-branched polyether polyol obtained by a ring-opening reaction of a hydroxyalkyl oxetane (a1) and a monofunctional epoxy compound (a2) can be preferably used. Here, “multi-branch” means a molecular structure in which a molecular chain is further branched into two or more at a point where the molecular chain is branched into two or more.

  As said hydroxyalkyl oxetane (a1), what has a structure represented by following General formula (1) can be used, for example.

(R ₁ in the general formula (1) represents a methylene group, an ethylene group or a propylene group, and R ₂ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxyalkyl group having 1 to 5 carbon atoms. Or a hydroxyalkyl group having 1 to 6 carbon atoms.)
Examples of the alkyl group having 1 to 8 carbon atoms that can constitute R ₂ in the general formula (1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and a 2-ethylhexyl group. Is mentioned.

Examples of the alkoxyalkyl group having 1 to 5 carbon atoms that can constitute R ₂ in the general formula (1) include a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, a methoxyethyl group, and an ethoxyethyl group. And propoxyethyl group.

Examples of the hydroxyalkyl group having 1 to 6 carbon atoms that can constitute R ₂ in the general formula (1) include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.

As the hydroxyalkyl oxetane (a1), R ₁ in the general formula (1) is a methylene group from the viewpoint that the inertia radius is smaller, the viscosity of the multi-branched polyether polyol is low, and effective for liquefaction. And R ₂ is preferably an alkyl group having 1 to 7 carbon atoms, among which 3-hydroxymethyl-3-ethyloxetane and 3-hydroxymethyl-3-methyloxetane are used. More preferably.

  As the monofunctional epoxy compound (a2) that undergoes a ring-opening polymerization reaction with the hydroxyalkyl oxetane (a1), for example, a compound represented by the following general formula (2) can be used.

(In general formula (2), R ₃ represents an organic residue.)
R ₃ in the formula (2) may be bonded to carbon forming an epoxy group via a divalent organic residue or the like to form a ring, and in the general formula (1) those exemplified as R ₂ and may be similar.

  More specifically, as the monofunctional epoxy compound (a2), olefin epoxide, glycidyl ether compound, glycidyl ester compound and the like can be used.

  The olefin epoxide is not particularly limited, and specific examples include propylene oxide, 1-butene oxide, 1-pentene oxide, 1-hexene oxide, 1,2-epoxyoctane, 1,2-epoxydodecane, and cyclohexene oxide. , Cyclooctene oxide, cyclododecene oxide, styrene oxide, fluoroalkyl epoxide having 1 to 18 fluorine atoms, and the like can be used.

  The glycidyl ether compound is not particularly limited, but specific examples include methyl glycidyl ether, ethyl glycidyl ether, n-propyl glycidyl ether, i-propyl glycidyl ether, n-butyl glycidyl ether, i-butyl glycidyl ether, n -Pentyl glycidyl ether, 2-ethylhexyl-glycidyl ether, undecyl glycidyl ether, hexadecyl glycidyl ether, aryl glycidyl ether, phenyl glycidyl ether, 2-methylphenyl glycidyl ether, 4-t-butylphenyl glycidyl ether, 4-nonylphenyl Glycidyl ether, 4-methoxyphenyl glycidyl ether, and fluoroalkyl glycidyl ether having 1 to 18 fluorine atoms It can be used.

  Although it does not specifically limit as said glycidyl ester compound, As a specific example, glycidyl acetate, glycidyl propionate, glycidyl butyrate, glycidyl methacrylate, glycidyl benzoate, etc. can be used.

  As the monofunctional epoxy compound (a2), it is preferable to use an olefin epoxide from the viewpoint that the multi-branched polyether polyol has a low viscosity and is effective for liquefaction. Among them, propylene oxide and 1-butene oxide are preferable. More preferably, 1-pentene oxide or 1-hexene oxide is used.

  The multi-branched polyether polyol can be produced, for example, by a ring-opening polymerization reaction between the hydroxyalkyl oxetane (a1) and the monofunctional epoxy compound (a2). Examples of such production methods include, but are not limited to, the following methods.

(Method)
The hydroxyalkyl oxetane (a1) and the monofunctional epoxy compound (a2) are converted into [hydroxyalkyloxetane (a1) / 1 functional epoxy compound (a2)] = 1/1 to 1/10, preferably on a molar basis. Are mixed in a ratio of 1/1 to 1/6, more preferably 1/1 to 1/3. The resulting mixture and a peroxide free organic solvent such as diethyl ether, di-i-propyl ether, di-n-butyl ether, di-i-butyl ether, di-t-butyl ether, t-amyl methyl ether, t -The mass ratio of [{(a1) + (a2)} / organic solvent] to butyl methyl ether, cyclopentyl methyl ether or dioxolane is 1/1 to 1/5, preferably 1 / 1.5-1 to 1 / 4. More preferably, the raw material solution is mixed and dissolved at a ratio of 1 / 1.5 to 1 / 2.5.

  Next, the polymerization initiator or the organic solvent solution thereof is added for 0.1 to 1 hour, preferably 0.3 to 0.8 hour, more preferably 0.3 to 0.5 hour, and the temperature is -10 ° C to- The solution is added dropwise to the raw material solution cooled to 15 ° C. with stirring.

  The polymerization initiator is preferably 0.01 to 1.0 mol%, more preferably 0.03 to 0, based on the total molar amount of the hydroxyalkyl oxetane (a1) and the monofunctional epoxy compound (a2). 0.7 mol%, particularly preferably 0.05 to 0.5 mol%.

Any polymerization initiator can be used as long as there is no particular problem. For _{example, H 2 SO 4, HCl,} HBF 4, HPF 6, HSbF 6, HAsF 6, p- toluenesulfonic acid, Bronsted acids such as trifluoromethanesulfonic _{acid, BF 3, AlCl 3, TiCl} 4, SnCl 4 , etc. Lewis acid, triarylsulfonium-hexafluorophosphate, triarylsulfonium-antimonate, diaryliodonium-hexafluorophosphate, diaryliodonium-antimonate, N-benzylpyridinium-hexafluorophosphate, N-benzyl Onium salt compounds such as pyridinium-antimonate, triphenylcarbonium-tetrafluoroborate, triphenylcarbonium-hexafluorophosphate, triphenylcarbonium-hexaful Triphenylcarbonium salts such as oroantimonate, p-toluenesulfonyl chloride, methanesulfonyl chloride, trifluoromethanesulfonyl chloride, p-toluenesulfonic acid anhydride, methanesulfonic acid anhydride, trifluoromethanesulfonic acid anhydride, p-toluene Examples include alkylating agents such as sulfonic acid methyl ester, p-toluenesulfonic acid ethyl ester, methanesulfonic acid methyl ester, trifluoromethanesulfonic acid methyl ester, and trifluoromethanesulfonic acid trimethylsilyl ester.

From the viewpoint of improving the reactivity, it is preferable to use HPF ₆ , HSbF ₆ , HAsF ₆ , triphenylcarbonium-hexafluorophosphate, and BF ₃ as the polymerization initiator, and among them, HPF ₆ , triphenylcarbohydrate. More preferably, nitro-hexafluorophosphate and BF ₃ are used.

  As the organic solvent when the polymerization initiator is used as an organic solvent solution, peroxide-free organic solvents such as diethyl ether, di-i-propyl ether, di-n-butyl ether, di-i-butyl ether, -T-Butyl ether, t-amyl methyl ether, t-butyl methyl ether, cyclopentyl methyl ether or dioxolane can be used.

  Moreover, when using the organic solvent solution of the said polymerization initiator, from a viewpoint of improving reactivity, the density | concentration of the polymerization initiator in the said solution is 1-90 mass%, Preferably it is 10-75 mass%, More preferably Is 25-65 mass%.

  After completion of the dropwise addition, the raw material solution containing the polymerization initiator is stirred until it reaches 25 ° C., then heated to the refluxing temperature, and the hydroxyalkyloxetane (a1) and monofunctional are added over 0.5 to 20 hours. A polymer solution is obtained by performing a polymerization reaction until most of the epoxy compound (a2) is converted into a multi-branched polyether polyol. The conversion rate of the hydroxyalkyl oxetane (a1) and the epoxy compound (a2) to the multi-branched polyether polyol (A) is determined using a gas chromatography, a nuclear magnetic resonance apparatus, or an infrared absorption spectrometer. Can be confirmed.

  After completion of the ring-opening polymerization reaction, the polymerization initiator remaining in the obtained reaction solution is deactivated using an equivalent amount of an alkali hydroxide aqueous solution, sodium alkoxide, or potassium alkoxide. Then, after filtering the said reaction solution and extracting a multibranched polyether polyol using a solvent, a multibranched polyether polyol can be obtained by distilling off the organic solvent under reduced pressure.

  The specific structure of the multi-branched polyether polyol may include various structures obtained by subjecting a hydroxyalkyl oxetane (a1) and a monofunctional epoxy compound (a2) to a ring-opening polymerization reaction.

  For example, a hydroxyalkyloxetane (a1) represented by the following general formula (1) and a monofunctional epoxy compound (a2) represented by the following general formula (2) are subjected to a ring-opening reaction. The following structural units are included: That is, the multi-branched polyether polyol can be composed of structural units appropriately selected from repeating units and terminal structural units represented by the following structure.

(R ₁ in the general formula (1) represents a methylene group, an ethylene group or a propylene group, and R ₂ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxyalkyl group having 1 to 5 carbon atoms. Or a hydroxyalkyl group having 1 to 6 carbon atoms.)

(In the general formula (2), R ₃ represents an organic residue. R ₃ may be bonded to carbon forming an epoxy group via a divalent organic residue or the like to form a ring. R ₃ may be a group selected from the example of R _2. )

  Here, the solid line portion of each of the structural units of OR1 to OR3, OE1, OE2, ER1, EE1, and EE2 indicates a single bond in the structural unit, and the broken line portion indicates a gap between the structural unit and other structural units. And a single bond forming an ether bond.

  The OR1 to OR3, OE1, and OE2 are structural units derived from the hydroxyalkyl oxetane (a1), of which OR1 to OR3 represent repeating units, and OE1 and OE2 are terminal structures of the multi-branched polyether polyol. Represents a unit.

  ER1, EE1, and EE2 are structural units derived from the monofunctional epoxy compound (a2), in which ER1 represents a repeating unit, and EE1 and EE2 represent terminal structural units of the multi-branched polyether polyol. To express.

  In the multi-branched polyether polyol, a continuous multi-branched structure can be formed by repeating units selected from the OR1 to OR3 and ER1. And the terminal structural unit selected from the said OE1, OE2, EE1, and EE2 can be provided at the terminal of the multi-branched structure. In addition, these repeating units and terminal structural units may exist in any configuration as long as there is no particular problem, and may exist in any proportion and amount. For example, the repeating unit and the terminal structural unit may be present at random, or OR1 to OR3 may constitute the central part of the molecular structure and have the terminal structural unit at the terminal.

  The multi-branched polyether polyol preferably has a primary hydroxyl group and a secondary hydroxyl group in its molecular structure. In particular, it is presumed that the pot life of the adhesive of the present invention can be secured to some extent due to the reaction delay of the secondary hydroxyl group.

The molecular structure of the multi-branched polyether polyol has a three-dimensional structure such as a spherical shape or a dendritic shape due to the multi-branching. At this time, the hydroxyl group is presumed to exist facing the outside of the shape. Therefore, even when the reaction rate is decreased due to the presence of secondary hydroxyl groups, since most hydroxyl groups present in the multi-branched polyether polyol can be sufficiently involved in the reaction, the adhesive of the present invention can be used. It is considered that the crosslink density of the cured product can be remarkably improved.
Thus, from the viewpoint of improving the sufficient pot life of the adhesive of the present invention and the excellent curability of the obtained cured product, the secondary hydroxyl group in the multi-branched polyether polyol adhesive is improved. The number is preferably 20 to 70%, more preferably 25 to 60%, based on the total number of hydroxyl groups.

  The number average molecular weight (Mn) of the multi-branched polyol (A) is preferably 1,000 to 4,000, more preferably 1,300 to 3,500. When the multi-branched polyol (A) is the multi-branched polyether polyol, it is preferable to use one having a number average molecular weight of 1,300 to 3,500.

  The hydroxyl value of the multi-branched polyol (A) is preferably 150 to 350 mg · KOH / g, more preferably 170 to 330 mg · KOH / g.

  The multi-branched polyol (A) having a number average molecular weight and a hydroxyl value in such a range is liquid at room temperature and exhibits good fluidity, and therefore has an alicyclic epoxy compound having two or more alicyclic epoxy groups ( B) can be easily blended with the acid generator (C) and the like, and the cationic polymerizable adhesive using the multi-branched polyol (A) is easy to apply and has excellent wettability to the substrate.

  The above-mentioned liquid means that it has fluidity at room temperature, and specifically, the viscosity by a BH type rotational viscometer is 100 Pa · s (25 ° C.) or less from the viewpoint of easy blending. State.

  Next, the alicyclic epoxy compound (B) having two or more alicyclic epoxy groups used in the present invention will be described.

  The alicyclic epoxy group possessed by the alicyclic epoxy compound (B) is two carbon atoms (usually adjacent to each other) among the carbon atoms forming the alicyclic structure of the alicyclic compound. ) Represents an epoxy group to which one common oxygen atom is bonded.

  Further, the alicyclic epoxy compound (B) is not particularly limited, but it is excellent to use a compound having 2 to 4 alicyclic epoxy groups with excellent curability and good initial property. This is preferable from the viewpoint of obtaining a cationic polymerizable adhesive capable of achieving both adhesiveness and normal adhesiveness.

  Examples of the alicyclic epoxy compound (B) include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate represented by the following general formula (3) (in the formula (3), a is 0). Compound), its caprolactone-modified product (compound of formula (3), wherein a is 1), its trimethylcaprolactone-modified product (Structural Formula (4) and Structural Formula (5)), and its valerolactone-modified product (Structure) A compound represented by the formula (6) and the structural formula (7)) or the structural formula (8) can be used.

  In the general formula (3), a represents 0 or 1.

Examples of the 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate represented by the general formula (3) and its caprolactone modified product include, for example, ceroxide 2021, ceroxide 2021A, ceroxide 2021P, ceroxide 2081, ceroxide 2083, Celoxide 2085 (manufactured by Daicel Chemical Industries, Ltd.), Syracure UVR-6105, Syracure UVR-6107, Syracure UVR-6110 (manufactured by Dow Chemical Japan Co., Ltd.) and the like are commercially available.
Examples of the adipic ester-based alicyclic epoxy compound represented by the general formula (8) include commercially available Cyracure UVR-6128 (manufactured by Dow Chemical Japan Co., Ltd.).
Moreover, as an alicyclic epoxy compound which has three alicyclic epoxy groups, the compound shown by following General formula (9) can be used.

  In general formula (9), b and c are each independently 0 or 1, and they may be the same or different.

  As the alicyclic epoxy compound represented by the general formula (9), for example, Epolide GT301, Epolide GT302 (manufactured by Daicel Chemical Industries, Ltd.) and the like are commercially available.

  Moreover, as an alicyclic epoxy compound which has four alicyclic epoxy groups, the compound shown, for example by following General formula (10) can be used.

  In the general formula (10), d to g each independently represent 0 or 1, and they may be the same or different.

  As the alicyclic epoxy compound represented by the general formula (10), for example, Epolide GT401, Epolide GT403 (manufactured by Daicel Chemical Industries, Ltd.) and the like are commercially available.

  The content of the alicyclic epoxy compound (B) contained in the cationic polymerizable adhesive of the present invention is not particularly limited, but the alicyclic epoxy compound (B) has an alicyclic. The molar ratio of the epoxy group and the hydroxyl group of the multibranched polyol (A) [the alicyclic epoxy group of the alicyclic epoxy compound (B) / the hydroxyl group of the multibranched polyol (A)] is 1 or more. A certain range is preferable, and a range of 1 to 5 is more preferable. Since the cationic polymerizable adhesive containing the alicyclic epoxy compound (B) in such a range is excellent in curability, it can exhibit excellent initial adhesiveness and normal adhesiveness.

Next, the acid generator (C) used in the present invention will be described.
As an acid generator (C) used by this invention, a photo-acid generator, a thermal acid generator, etc. can be used individually, or 2 or more types can be used together, for example.

  The photoacid generator means a compound that generates an acid capable of initiating cationic polymerization by ultraviolet irradiation, and the thermal acid generator refers to a compound that generates an acid capable of initiating cationic polymerization by heat. means.

As the photoacid generator, for example, the cation moiety is aromatic sulfonium, aromatic iodonium, aromatic diazonium, aromatic ammonium, thioxanthonium, (2,4-cyclopentadien-1-yl) [(1- Methylethyl) benzene] -iron cation, and thianthrium, and the anion moiety is BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , [BX ₄ ] ⁻ (where X is a hydrogen atom of the phenyl group) Two or more of the above represent a functional group substituted with a fluorine atom or a trifluoromethyl group.), An aromatic sulfonium salt, an aromatic iodonium salt, an aromatic diazonium salt, an aromatic ammonium salt, a thioxan Tonium salt, (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -iron salt, etc. Can be used alone or in combination of two or more.

  Examples of the aromatic sulfonium salt include bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluorophosphate, bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluoroantimonate, and bis [4- (diphenyl). Sulfonio) phenyl] sulfide bistetrafluoroborate, bis [4- (diphenylsulfonio) phenyl] sulfide tetrakis (pentafluorophenyl) borate, diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate, diphenyl-4- (phenylthio) ) Phenylsulfonium hexafluoroantimonate, diphenyl-4- (phenylthio) phenylsulfonium tetrafluoroborate, diphenyl-4- (phenylthio) E) Phenylsulfonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, bis [4- ( Di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bishexafluorophosphate, bis [4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bishexafluoroantimony Bis [4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bistetrafluoroborate, bis [4- ( Di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide tetrakis (pentafluorophenyl) borate and the like can be used.

  Examples of the aromatic iodonium salt include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis (pentafluorophenyl) borate, bis (dodecylphenyl) iodonium hexafluorophosphate, Bis (dodecylphenyl) iodonium hexafluoroantimonate, bis (dodecylphenyl) iodonium tetrafluoroborate, bis (dodecylphenyl) iodonium tetrakis (pentafluorophenyl) borate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium Hexafluorophosphate, 4-methylphenyl-4- (1-methyl Ethyl) phenyliodonium hexafluoroantimonate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrafluoroborate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) borate Etc. can be used.

  Examples of the aromatic diazonium salt include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis (pentafluorophenyl) borate.

  Examples of the aromatic ammonium salt include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2-cyanopyridinium tetrafluoroborate, 1-benzyl 2-cyanopyridinium tetrakis (pentafluorophenyl) borate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluorophosphate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluoroantimonate, 1- (naphthylmethyl) -2-Cyanopyridinium tetrafluoroborate, 1- (naphthylmethyl) -2-cyanopyridinium tetrakis (pentafluorophenyl) borate, and the like can be used.

  Moreover, S-biphenyl 2-isopropyl thioxanthonium hexafluorophosphate etc. can be used as said thioxanthonium salt.

  The (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -iron salt includes (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene. ] -Iron (II) hexafluorophosphate, (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -Iron (II) hexafluoroantimonate, 2,4-cyclopentadiene-1- Yl) [(1-methylethyl) benzene] -iron (II) tetrafluoroborate, 2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -iron (II) tetrakis (pentafluorophenyl) ) Borate and the like can be used.

  Examples of the photoacid generator include CPI-100P, CPI-101A, CPI-200K (manufactured by San Apro Co., Ltd.), Cyracure photocuring initiator UVI-6990, Cyracure photocuring initiator UVI-6922, Cyracure. Photocuring initiator UVI-6976 (above, manufactured by Dow Chemical Japan Co., Ltd.), Adekaoptomer SP-150, Adekaoptomer SP-152, Adekaoptomer SP-170, Adekaoptomer SP-172 (above, Asahi Denka Kogyo Co., Ltd.), CI-5102, CI-2855 (Nippon Soda Co., Ltd.), Sun-Aid SI-60L, Sun-Aid SI-80L, Sun-Aid SI-100L, Sun-Aid SI-110L, Sun-Aid SI- 180L, Sun-Aid SI-110, Sun-Aid SI-145, Sun-Aid I-150, Sun-Aid SI-160, Sun-Aid SI-180 (above, manufactured by Sanshin Chemical Industry Co., Ltd.), Esacure 1064, Esacure 1187 (above, manufactured by Lamberti), Omnicat 432, Omnicat 440, Omnicat 445, Omnicat 550, Omnicat 650, Omnicat BL-550 (manufactured by IG Resin Co., Ltd.), Irgacure 250 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Rhodosil Photo Initiator 2074 (RHODORSIL PHOTOINITIATOR 2074 (Rhodia Japan) Etc.) are commercially available.

As the thermal acid generator, for example, the cation moiety is quaternary ammonium, sulfonium, phosphonium, or iodonium, and the anion moiety is BF ₄ −, PF ₆ −, SbF ₆ −, SbF ₄ −, AsF _6. A quaternary ammonium salt, a sulfonium salt, a phosphonium salt, an iodonium salt, or the like composed of-can be used alone or in combination of two or more.

  Examples of the quaternary ammonium salt include N, N-dimethyl-N-benzylanilinium hexafluoroantimonate, N, N-diethyl-N-benzylanilinium tetrafluoroborate, N, N-dimethyl-N-benzyl. Pyridinium hexafluoroantimonate, N, N-diethyl-N-benzylpyridinium trifluoromethanesulfonic acid, N, N-dimethyl-N- (4-methoxybenzyl) pyridinium hexafluoroantimonate, N, N-diethyl-N- ( 4-methoxybenzyl) pyridinium hexafluoroantimonate, N, N-diethyl-N- (4-methoxybenzyl) toluidinium hexafluoroantimonate, N, N-dimethyl-N- (4-methoxybenzyl) toluidinium hexafluoroantimony Can be used.

  Examples of the sulfonium salt include triphenylsulfonium tetrafluoroborate, 2-butenyltetramethylenesulfonium hexafluoroantimonate, 3-methyl-2-butenyltetramethylenesulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroantimonate. , Triphenylsulfonium hexafluoroarsenate, tri (4-methoxyphenyl) sulfonium hexafluoroarsenate, diphenyl (4-phenylthiophenyl) sulfonium hexafluoroarsenate, and the like can be used.

  As the phosphonium salt, for example, ethyltriphenylphosphonium tetrafluoroborate, tetrabutylphosphonium tetrafluoroborate and the like can be used.

  Examples of the iodonium salt include diphenyliodonium hexafluoroarsenate, di-4-chlorophenyliodonium hexafluoroarsenate, di-4-bromophenyliodonium hexafluoroarsenate, di-p-tolyliodonium hexafluoroarsenate, phenyl (4-Methoxyphenyl) iodonium hexafluoroarsenate or the like can be used.

  Examples of the thermal acid generator include Adeka Opton CP-66, Adeka Opton CP-77 (above, manufactured by Asahi Denka Kogyo Co., Ltd.), CI-2855 (above, manufactured by Nippon Soda Co., Ltd.), Sun-Aid SI-60L, Sun-Aid SI-80L, Sun-Aid SI-100L, Sun-Aid SI-110L, Sun-Aid SI-180L, Sun-Aid SI-110, Sun-Aid SI-145, Sun-Aid SI-150, Sun-Aid SI-160, Sun-Aid SI-180 (above, Sanshin Chemical) Kogyo Co., Ltd.) is commercially available.

  CI-2855 (Nippon Soda Co., Ltd.), Sun-Aid SI-60L, Sun-Aid SI-80L, Sun-Aid SI-100L, Sun-Aid SI-110L, Sun-Aid SI-180L, Sun-Aid SI-110, Sun-Aid SI- 145, Sun-Aid SI-150, Sun-Aid SI-160, and Sun-Aid SI-180 (manufactured by Sanshin Chemical Industry Co., Ltd.) can generate an acid regardless of light irradiation or heating.

  Although the usage-amount of the said acid generator (C) is not necessarily limited, 0.1-15 mass% with respect to the whole quantity of the said multibranched polyol (A) and the said alicyclic epoxy compound (B). The range is preferably 0.5 to 10% by mass, more preferably 1.0 to 7.5% by mass. By using the acid generator (C) within the above range, a cationic polymerizable adhesive exhibiting excellent storage stability, excellent curability, and good adhesion to a substrate can be obtained. Since the residual amount of the acid generated by the acid generator (C) in the cured product can be reduced, deterioration of the metal substrate due to the acid can be suppressed.

  In addition to the multi-branched polyol (A), the alicyclic epoxy compound (B), and the acid generator (C), the cation polymerizable compound of the present invention further includes an oxetane compound (D ) May be used in combination. By using the oxetane compound (D) in combination, it is possible to further improve the curability of the cationic polymerizable adhesive, so that excellent initial adhesiveness and normal adhesiveness can be expressed.

  The oxetane compound (D) means a compound having an oxetane ring structure represented by the following structural formula (11) in the molecule.

  As the oxetane compound (D), for example, compounds represented by the following general formulas (12), (13) and (14) can be used alone or in combination of two or more.

In the general formulas (12), (13) and (14), R ₄ is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group, an aralkyl group. Represents a furyl group or a thienyl group, and R ₅ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or a group having an aromatic ring. Represents an alkylcarbonyl group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, or an N-alkylcarbamoyl group having 2 to 6 carbon atoms, an acryloyl group, and a methacryloyl group, and R ₆ is divalent. And Z represents an oxygen atom or a sulfur atom.

Examples of the linear, branched or cyclic alkyl group having 1 to 6 carbon atoms represented by R ₄ include a methyl group, an ethyl group, an n- or i-propyl group, an n-, i- or t- group. A butyl group, a pentyl group, a hexyl group, a cyclohexyl group, and the like; and an aryl group such as a phenyl, naphthyl, tolyl, and xylyl group; and an aralkyl group such as a benzyl and phenethyl group It is.

Examples of the linear, branched or cyclic alkyl group having 1 to 8 carbon atoms represented by R ₅ include a methyl group, an ethyl group, an n- or i-propyl group, an n-, i- or t- group. Examples thereof include a butyl group, a pentyl group, a hexyl group, a cyclohexyl group, and a 2-ethylhexyl group. Examples of the alkenyl group having 2 to 6 carbon atoms include a 1-propenyl group, a 2-propenyl group, and 2-methyl-1-propenyl. Group, 2-methyl-2-propenyl group, 1-butenyl group, 2-butenyl group or 3-butenyl group, and the group having an aromatic ring includes, for example, phenyl group, benzyl group, fluorobenzyl group, methoxybenzyl Group or a phenoxyethyl group, and examples of the alkylcarbonyl group having 2 to 6 carbon atoms include an ethylcarbonyl group and a propylcarbonyl group. Group or a butylcarbonyl group.

In the general formula (13), examples of the divalent organic residue represented by R ₆ include a linear, branched, or cyclic alkylene group and a polyoxyalkylene having 4 to 30 carbon atoms. Groups, phenylene groups, xylylene groups, and structures represented by the following general formulas (15) and (16).

The linear, branched, or cyclic alkylene group constituting R ₆ has 1 carbon atom such as a methylene group, an ethylene group, a 1,2- or 1,3-propylene group, a butylene group, and a cyclohexylene group. It is preferably an alkylene group of ˜15. Further, the polyoxyalkylene group having 4 to 30 carbon atoms is preferably one having 4 to 8 carbon atoms, and is preferably a polyoxyethylene group or a polyoxypropylene group, for example.

In the general formula (15), R ₇ represents an oxygen atom, a sulfur atom, CH ₂ , NH, SO, SO ₂ , C (CF ₃ ) ₂ or C (CH ₃ ) ₂ .

In the general formula (16), R ₈ represents an alkylene group having 1 to 6 carbon atoms, an arylene group, and a functional group represented by the following general formula (17).

  In the general formula (17), h represents an integer of 1 to 6, and i represents an integer of 1 to 15. The i is preferably an integer of 1 to 3.

  Examples of the oxetane compound (D) include Aron Oxetane OXT-101, Aron Oxetane OXT-121, Aron Oxetane OXT-212, Aron Oxetane OXT-221 (above, manufactured by Toagosei Co., Ltd.), Etanacol EHO, Etanacol OXMA Etanacol OXBP, Etanacol OXTP (manufactured by Ube Industries, Ltd.) and the like are commercially available.

  When the oxetane compound (D) is used in combination, the content of the oxetane compound (D) is not particularly limited, but the oxetaneyl group of the oxetane compound (D) and the alicyclic epoxy compound (B ) And the alicyclic epoxy group possessed by [Oxetanyl group possessed by oxetane compound (D) / alicyclic epoxy group possessed by alicyclic epoxy compound (B)] is 0.01-5. Preferably, it is 0.1-2.5. The cationic polymerizable adhesive containing the oxetane compound (D) in such a range is excellent in that it can further reduce the amount of the alicyclic epoxy compound (B) remaining unreacted and is further excellent in curability. The initial adhesiveness and normal adhesiveness can be expressed.

  The cationically polymerizable adhesive of the present invention can be produced, for example, by the following method.

  The cationically polymerizable adhesive of the present invention includes, for example, a closed-type planetary mixer or the like, the multi-branched polyol (A) having the hydroxyl group, the alicyclic epoxy compound (B), and if necessary, the oxetane compound ( D) can be mixed and stirred until uniform, and then the acid generator (C) is mixed and stirred.

  The cationically polymerizable adhesive of the present invention may contain various additives as necessary within a range not impairing the effects of the present invention.

  Examples of the additive include silane coupling agents, organic solvents, fillers, thixotropic agents, sensitizers, various polyols described above and other polyols, leveling agents, antioxidants, tackifiers, and waxes. , Heat stabilizer, light resistance stabilizer, fluorescent whitening agent, foaming agent, organic pigment, inorganic pigment, dye, conductivity imparting agent, antistatic agent, moisture permeability improver, water repellent, hollow foam, flame retardant, In addition to water-absorbing agents, moisture-absorbing agents, deodorants, foam stabilizers, antifoaming agents, antifungal agents, antiseptics, algae-proofing agents, pigment dispersants, antiblocking agents, hydrolysis inhibitors, and other organic and inorganic water-soluble substances Other resins such as compounds, thermoplastic resins and thermosetting resins can be used in combination.

  Typical examples of the additive include the following silane coupling agents, fillers, and thixotropic agents.

  Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2- (3,4-epoxycyclohexyl). ) Ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3- Methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, vinyltrimethoxysilane, vinyltri Tokishishiran, 3-chloropropyl trimethoxy silane or bis (triethoxysilylpropyl) can be used tetrasulfide and the like.

  As the filler, for example, calcium carbonate, aluminum hydroxide, barium sulfate, kaolin, talc, carbon black, alumina, magnesium oxide, inorganic or organic balloon, lithia tourmaline, activated carbon and the like can be used.

  As the thixotropic agent, for example, surface-treated calcium carbonate, fine powder silica, bentonite, zeolite, and the like can be used.

  When using the various additives described above, the additive is, for example, using the closed planetary mixer or the like, the multi-branched polyol (A), the alicyclic epoxy compound (B), and if necessary, the above-mentioned When the oxetane compound (D) is mixed and stirred, they can be mixed together.

  The cationic polymerizable adhesive of the present invention can be cured by ultraviolet irradiation or heating. The curing method can be selected depending on the acid generator used.

When using a photoacid generator as the acid generator (C) is preferably 50 to 5000 mJ / cm ^2, more preferably 100~3000mJ / cm ^2, particularly preferably in the range of 100~1000mJ / cm ² Polymerization can be initiated by irradiation with ultraviolet light. Moreover, hardening can further be accelerated | stimulated by heating so that the temperature of a cationically polymerizable adhesive may be 60-80 degree | times after ultraviolet irradiation. For example, a known lamp such as a xenon lamp, a xenon-mercury lamp, a metal halide lamp, a high-pressure mercury lamp, or a low-pressure mercury lamp can be used as the ultraviolet ray generation source. In addition, the ultraviolet irradiation amount was based on a value measured in a wavelength region of 300 to 390 nm using a UV checker UVR-N1 (manufactured by Nippon Battery Co., Ltd.). Moreover, when using a thermal acid generator as said acid generator (C), the temperature of the apply | coated cationic polymerizable adhesive is 60-200 degreeC, Preferably it is 80-180 degree | times, More preferably, it is 100-150 degreeC. Polymerization can be initiated by heating to

  Moreover, the cationically polymerizable adhesive of the present invention can be used particularly for the production of a laminate comprising a plastic substrate, and can be suitably used for the production of optical members such as polarizing plates.

  A polarizing plate usually refers to a polarizer having protective films attached to both sides of a polarizer. Here, the adhesive of this invention can be used conveniently for adhesion | attachment with the said polarizer and a protective film.

  As the transparent protective film, it is preferable to use a plastic film made of a cellulose-based polymer such as triacetyl cellulose, a resin having a cycloolefin structure, a norbornene resin, etc., from the viewpoint of improving polarization characteristics, durability, and the like. It is particularly preferable to use a plastic film made of norbornene resin.

  In addition, the polarizer is not particularly limited, and various types of polarizers can be used. For example, from a hydrophilic polymer such as polyvinyl alcohol, partially formalized polyvinyl alcohol, ethylene / vinyl acetate copolymer partially saponified product, etc. Using uniaxially drawn dichroic materials such as iodine and dichroic dyes on a plastic base material, polyene-based oriented films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride can do. Of these, it is preferable to use a polyvinyl alcohol film and a film on which a dichroic substance such as iodine is adsorbed.

  The thickness of the plastic substrate that can be used when producing the laminate and the polarizing plate of the present invention varies depending on the intended use, but is preferably in the range of about 10 μm to 3 mm.

  The surface of the plastic substrate is preferably subjected to a surface treatment such as corona discharge treatment, ultraviolet irradiation treatment or alkali treatment. It is preferable to use a plastic substrate having a surface condition of preferably 45 mN / m or more, more preferably 50 mN / m or more in terms of wetness index. In addition, the said wetting index means the critical surface tension by Zisman, and is a value measured with a standard wetting reagent based on JISK8768.

  Examples of the method for applying the cationic polymerizable adhesive of the present invention on the plastic substrate include conventionally known coating methods such as gravure coating, rod coating, spray coating, air knife coating, and roll coating. Can be applied onto the plastic substrate.

  The cationic polymerizable adhesive for plastic substrates of the present invention is preferably applied so that the film thickness is in the range of 0.01 to 100 μm, and more preferably in the range of 0.05 to 50 μm.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention more concretely, this invention is not necessarily limited to the following Example.

[Synthesis Example 1]
<Synthesis of multi-branched polyol (I)>
In a 2-liter three-necked flask equipped with a reflux condenser, a magnetic stirring bar, and a thermometer, 348 parts by mass (3 mol) of 3-hydroxymethyl-3-ethyloxetane and 348 parts by mass (6 mol) of propylene oxide were sufficiently dried. Were then dissolved in 1 liter of diethyl ether free of peroxide and then cooled in an ice bath at -14 ° C.

Then, a 60 wt% aqueous solution of _HPF 6 5.5 parts by weight was added dropwise over 10 minutes to the flask as an initiator. The mixture in the flask became slightly cloudy.

  The mixture in the flask was then allowed to react overnight at room temperature, and the next morning the clear reaction mixture was refluxed for 3 hours.

Subsequently, the initiator was deactivated using a 9% by mass NaOCH ₃ 30% by mass methanol solution.

  After filtering the reaction mixture after deactivation of the initiator, diethyl ether in the reaction mixture was distilled off by heating at a bath temperature of 75 ° C. under reduced pressure. After diethyl ether was completely distilled off, 667 parts by mass of a multi-branched polyether polyol (I) was obtained. The yield was 89% by mass.

  This multi-branched polyether polyol (I) has a number average molecular weight (Mn) = 1,440, a weight average molecular weight (Mw) = 3,350, and a hydroxyl value (OHV) = 265 mg · KOH / g. The molar ratio of 3-hydroxymethyl-3-ethyloxetane to propylene oxide was 1: 1.9.

[Example 1]
In a closed planetary mixer, 65.1 parts by mass of the multi-branched polyether polyol (I), Cyracure UVR-6110 (3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, Dow Chemical Japan ( Co., Ltd.) 34.9 parts by mass was charged and mixed and stirred until uniform.
Next, by mixing and stirring 5 parts by mass of CPI-100P (diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate 50% by mass solution, manufactured by San Apro Co., Ltd.), the cationic polymerizable adhesive is obtained. Prepared.

[Example 2]
In a closed planetary mixer, 62.7 parts by mass of the multi-branched polyether polyol (I) and 37.3 parts by mass of Cyracure UVR-6110 were charged and mixed and stirred until uniform.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Example 3]
In a closed planetary mixer, 50.0 parts by mass of the multi-branched polyether polyol (I) and 50.0 parts by mass of Cyracure UVR-6110 were charged and mixed and stirred until uniform.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Example 4]
In a closed type planetary mixer, 25.0 parts by mass of the multi-branched polyether polyol (I) and 75.0 parts by mass of Cyracure UVR-6110 were charged and mixed and stirred until uniform. Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Example 5]
In a closed planetary mixer, 10.0 parts by mass of the multi-branched polyether polyol (I) and 90.0 parts by mass of Cyracure UVR-6110 were charged and mixed and stirred until uniform. Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Example 6]
In a closed planetary mixer, 49.0 parts by mass of the multi-branched polyether polyol (I), 49.0 parts by mass of Cyracure UVR-6110, Aron oxetane OXT-221 (bis [1-ethyl (3-oxetanyl)] ] 2.0 parts by mass of methyl ether (manufactured by Toa Gosei Co., Ltd.) were mixed and stirred until uniform.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Example 7]
In a closed planetary mixer, 41.2 parts by mass of the multi-branched polyether polyol (I), 41.2 parts by mass of Cyracure UVR-6110, and 17.6 parts by mass of Aron Oxetane OXT-221 were charged uniformly. Mix and stir until.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Example 8]
In a closed type planetary mixer, 35.1 parts by mass of the multi-branched polyether polyol (I), 35.1 parts by mass of Cyracure UVR-6110, and 29.8 parts by mass of Aron Oxetane OXT-221 are charged uniformly. Mix and stir until.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Example 9]
In a closed type planetary mixer, 22.0 parts by mass of the multi-branched polyether polyol (I), 22.0 parts by mass of Cyracure UVR-6110, and 56.0 parts by mass of Aron Oxetane OXT-221 were charged uniformly. Mix and stir until.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Comparative Example 1]
100.0 parts by mass of Syracure UVR-6110 and 5 parts by mass of CPI-100P are charged.
A cationically polymerizable adhesive was prepared by mixing and stirring until uniform.

[Comparative Example 2]
A cationic polymerizable adhesive was prepared by charging 100.0 parts by mass of Aron oxetane OXT-221 and 5 parts by mass of CPI-100P, and mixing and stirring until uniform.

[Comparative Example 3]
50.0 parts by mass of Syracure UVR-6110 and 50.0 parts by mass of Alonoxetane OXT-221 were charged and mixed and stirred until uniform.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Comparative Example 4]
50.0 parts by mass of the multi-branched polyether polyol (I), Aron oxetane OXT-221
Of 50.0 parts by mass was mixed and stirred until uniform.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Comparative Example 5]
Charge 50.0 parts by mass of the multi-branched polyether polyol (I) and 50.0 parts by mass of EX-214L (1,4-butanediol diglycidyl ether, manufactured by Nagase ChemteX Corp.) and mix until uniform. , Stirred.
Next, a cationically polymerizable adhesive was prepared by mixing and stirring CPI-100P: 5 parts by mass.

[Comparative Example 6]
50.0 parts by mass of the multi-branched polyether polyol (I) and 50.0 parts by mass of jER828 (bisphenol A type epoxy resin, Japan Epoxy Resin Co., Ltd.) were charged and mixed and stirred until uniform.
Next, a cationically polymerizable adhesive was prepared by mixing and stirring CPI-100P: 5 parts by mass.

[Comparative Example 7]
PTMG-2000 (polytetramethylene glycol, hydroxyl value (OHV) = 56 mg · KOH / g, manufactured by Mitsubishi Chemical Corporation) 50.0 parts by mass, Cyracure UVR-6110 50.0 parts by mass are charged, and uniform. Until mixed.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Comparative Example 8]
Exenol 2020 (polypropylenediol, hydroxyl value (OHV) = 56 mg · KOH / g, manufactured by Asahi Glass Co., Ltd.) 50.0 parts by mass, Cyracure UVR-6110 50.0 parts by mass, and mixed until uniform, Stir.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Comparative Example 9]
Exenol 3030 (polypropylene triol, hydroxyl value (OHV) = 56 mg · KOH / g, manufactured by Asahi Glass Co., Ltd.) 50.0 parts by mass, Cyracure UVR-6110 50.0 parts by mass, and mixed until uniform, Stir.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Comparative Example 10]
PEG # 2000U (polyethylene glycol, hydroxyl value (OHV) = 56.1 mg · KOH / g, manufactured by NOF Corporation) and 50.0 parts by mass of Cyracure UVR-6110 were charged uniformly. Mix and stir until.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Comparative Example 11]
15.0 parts by mass of glycerin and 85.0 parts by mass of Cyracure UVR-6110 were charged and mixed and stirred until uniform.
Next, 5 mass parts of CPI-100P was mixed and stirred to prepare a cationic polymerizable adhesive.

[Comparative Example 12]
jERYX8000 (hydrogenated bisphenol A type epoxy resin, manufactured by Japan Epoxy Resins Co., Ltd.) 100.0 parts by mass, CI-5102 (organic iodonium hexafluorophosphate 50% by mass solution of γ-butyrolactone, Nippon Soda Co., Ltd. )) 4 parts by mass and CS-7001 (aromatic compound, Nippon Soda Co., Ltd.) 1 part by mass were charged and mixed and stirred until uniform to prepare a cationic polymerizable adhesive.

[Comparative Example 13]
Aliphatic polyester polyol water-based urethane resin (II) (non-volatile content: 50%) 66.7 parts by mass, Hydran Assist C1 (polyisocyanate compound, manufactured by Dainippon Ink & Chemicals) 33.3 parts by mass were charged uniformly. A water-based adhesive was prepared by mixing and stirring until.

[Comparative Example 14]
A water-based adhesive was prepared by measuring 100.0 parts by mass of Hydran Assist C1.

  The initial adhesiveness and normal state adhesiveness of the cationic polymerizable adhesives of Examples 1 to 9 and Comparative Examples 1 to 12 and the aqueous adhesives of Comparative Examples 13 and 14 were evaluated by the methods described below.

[Evaluation method of initial adhesion]
(Test piece preparation method)
The cationic polymerizable adhesives for plastic substrates described in Examples 1 to 9 and Comparative Examples 1 to 12 were applied on a norbornene film (thickness: 100 μm) previously subjected to corona treatment using an applicator (adhesive layer) About 10 μm), the adhesive-coated surface and the polyvinyl alcohol film (thickness 40 μm) were pressed and bonded together using a rubber roller to prepare a laminate. Next, using a conveyor type ultraviolet irradiation device CSOT-40 (manufactured by Nippon Battery Co., Ltd., using a high pressure mercury lamp, strength 120 W / cm), the norbornene film is adjusted so that the ultraviolet irradiation amount is 450 to 550 mJ / cm ^2. The above-mentioned cationically polymerizable adhesive was irradiated with ultraviolet rays.

  In addition, each plastic base aqueous adhesive described in Comparative Examples 13 and 14 was applied onto a norbornene film (thickness: 100 μm) that had been subjected to corona treatment in advance using an applicator (adhesive layer of about 10 μm). The coated surface and a polyvinyl alcohol film (thickness 40 μm) were pressed and bonded together using a rubber roller, and then a laminate was produced. Thereafter, the laminate produced using the aqueous adhesive for plastic substrates described in Comparative Example 15 was dried at 80 ° C. for 5 minutes.

Next, for each laminate, the peel strength after curing for 5 minutes in an environment of 23 ° C. was measured using a tensile tester (tensile speed = 50 mm / min T-type peel).
[Criteria]
The adhesive strength was evaluated according to the following criteria.
Good ... Peel strength of 10N / 25mm or more, or rupture of norbornene film (MB)
Defect ... Peel strength less than 10N / 25mm

  In addition, all said ultraviolet irradiation amount was based on the value measured in the wavelength range of 300-390 nm using UV checker UVR-N1 (made by Nippon Battery Co., Ltd.).

[Evaluation method for normal adhesion]
(Test piece preparation method)
The cationic polymerizable adhesives for plastic substrates described in Examples 1 to 9 and Comparative Examples 1 to 12 were applied on a norbornene film (thickness: 100 μm) previously subjected to corona treatment using an applicator (adhesive layer) About 10 μm), the adhesive-coated surface and the polyvinyl alcohol film (thickness 40 μm) were pressed and bonded together using a rubber roller to prepare a laminate. Next, using a conveyor type ultraviolet irradiation device CSOT-40 (manufactured by Nippon Battery Co., Ltd., using a high pressure mercury lamp, strength 120 W / cm), the norbornene film is adjusted so that the ultraviolet irradiation amount is 450 to 550 mJ / cm ^2. The above-mentioned cationically polymerizable adhesive was irradiated with ultraviolet rays.

  Also, each of the plastic base aqueous adhesives immediately after preparation described in Comparative Examples 13 and 14 was applied onto a norbornene film (thickness: 100 μm) that had been subjected to corona treatment in advance using an applicator (adhesive layer of about 10 μm). Then, the adhesive coated surface and the polyvinyl alcohol film (thickness 40 μm) were pressed together using a rubber roller, and then a laminate was prepared. Thereafter, the laminate produced using the aqueous adhesive for plastic substrates described in Comparative Example 15 was dried at 80 ° C. for 5 minutes.

Next, the peel strength after curing for 5 days in an environment of 40 ° C. was measured for each laminate using a tensile tester (tensile speed = 50 mm / min T-type peel).
[Criteria]
The adhesive strength was evaluated according to the following criteria.
Good ... Peel strength of 10N / 25mm or more, or rupture of norbornene film (MB)
Defect ... Peel strength less than 10N / 25mm

  In addition, all said ultraviolet irradiation amount was based on the value measured in the wavelength range of 300-390 nm using UV checker UVR-N1 (made by Nippon Battery Co., Ltd.).

[Method for evaluating curability]
About the adhesive agent of Examples 1-9 and Comparative Examples 1-12, after apply | coating to the thickness of 100 micrometers on a polypropylene board using an applicator, conveyor type ultraviolet irradiation apparatus CSOT-40 (Nippon Battery Co., Ltd.) ), Using a high-pressure mercury lamp, and an intensity of 120 W / cm), the ultraviolet curable resin composition was irradiated with ultraviolet rays so that the amount of ultraviolet irradiation was 700 to 800 mJ / cm ² . Thereafter, the film was cured by curing for 7 days in an atmosphere of temperature 23 ° C. and humidity 50% RH. About 1 g of the film was cut out and its initial mass (g) was measured using a precision electronic balance.

The film after measurement of the initial mass was immersed in 100 g of ethyl acetate at 50 ° C. for 24 hours. After immersion, the film in ethyl acetate was dried for 1 hour at 107 ° C., and then measured with a precision electronic balance to determine the mass (g) after immersion of the film.
The gel fraction (% by mass) was calculated based on the initial mass of the film, the mass after immersion, and the above formula.

  In addition, the water-based adhesives described in Comparative Examples 13 and 14 were applied on a polypropylene plate using an applicator so that the dry curtain pressure was 100 μm thick, and then the temperature was 23 ° C. and the humidity was 50% RH. Films were made by curing for 7 days and volatilizing the water.

The film after measurement of the initial mass was immersed in 100 g of ethyl acetate at 50 ° C. for 24 hours. After immersion, the film in ethyl acetate was dried for 1 hour at 107 ° C., and then measured with a precision electronic balance to determine the mass (g) after immersion of the film.
The gel fraction (% by mass) was calculated based on the initial mass of the film, the mass after immersion, and the above formula.

[Evaluation criteria for curability]
The ultraviolet curable resin composition having a gel fraction calculated by the above method of 90% by mass or more can be said to be excellent in curability and is practically preferable.

Description of compounds in Tables 1-6.
UVR-6110: 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate (manufactured by Dow Chemical Japan Co., Ltd., trademark: Cyracure, epoxy group equivalent weight = 137 g).

  CPI-100P: 50% by mass solution of propylene carbonate in diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate (manufactured by San Apro Co., Ltd.).

  CI-5102: γ-butyrolactone 50 mass% solution (manufactured by Nippon Soda Co., Ltd.) of organic iodonium hexafluorophosphate.

  OXT-221: Bis [1-ethyl (3-oxetanyl)] methyl ether (manufactured by Toagosei Co., Ltd., trademark: Aron oxetane, oxetanyl group equivalent weight = 107.2 g).

  CS-7001: Aromatic compound (manufactured by Nippon Soda Co., Ltd.).

  EX-214L: 1,4-butanediol diglycidyl ether (manufactured by Nagase ChemteX Corporation, trademark: Denacol, epoxy group equivalent weight = 120 g)

  jER828: Bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., epoxy group equivalent weight = 189 g)

  jERYX8000: Hydrogenated bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., epoxy group equivalent weight = 205 g)

  Exenol 2020: Polypropylenediol (Asahi Glass Co., Ltd.)

  Exenol 3030: Polypropylene triol (Asahi Glass Co., Ltd.)

  PEG # 2000U: Polyethylene glycol (manufactured by NOF Corporation)

  PTMG-2000: Polytetramethylene glycol (Mitsubishi Chemical Corporation)

  H2004: Hyperbranched polyester polyol (manufactured by Perstorp, trademark: Borton)

  C1: Polyisocyanate compound (Dainippon Ink Chemical Co., Ltd., trademark: Hydran Assister)

FIG. 1 is a ¹³ C-NMR chart of the multibranched polyol (I) obtained in Synthesis Example 1. FIG. 2 is a proton NMR chart of the multibranched polyol (I) obtained in Synthesis Example 1. FIG. 3 is a chemical formula showing an example of a multi-branched polyol used in the present invention. FIG. 4 is a chemical reaction formula showing an example of formation of a multi-branched polyol used in the present invention.

Claims (9)

A plastic comprising a multi-branched polyol (A) having 10 or more hydroxyl groups, an alicyclic epoxy compound (B) having two or more alicyclic epoxy groups, and an acid generator (C) Cationic polymerizable adhesive for substrate. The cationic polymerizable adhesive for plastic substrates according to claim 1, wherein the multi-branched polyol (A) has a number average molecular weight in the range of 1000 to 4000. The plastic according to claim 1, wherein the multi-branched polyol (A) is a multi-branched polyether polyol (a) obtained by ring-opening reaction of a hydroxyalkyl oxetane (a1) and a monofunctional epoxy compound (a2). Cationic polymerizable adhesive for substrate. The cationic polymerizable adhesive for plastic substrates according to claim 1, wherein the ratio of the epoxy group of the alicyclic epoxy compound (B) to 1 mol of the hydroxyl group of the multi-branched polyol (A) is 1 mol or more. . The cationically polymerizable adhesive for plastic substrates according to claim 1, further comprising an oxetane compound (D) having an oxetane ring structure. Two or more plastic base materials are adhere | attached using the cation polymerizable adhesive agent for plastic base materials in any one of Claims 1-5, The laminated body characterized by the above-mentioned. The laminate according to claim 6, wherein the plastic substrate is a substrate made of a resin having a cycloolefin structure. A polarizing plate, wherein two or more plastic substrates are bonded using the cationic polymerizable adhesive for plastic substrates according to any one of claims 1 to 5. The polarizing plate according to claim 8, wherein the plastic substrate is a substrate made of a resin having a cycloolefin structure.

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