JP6666767B2 - Curable composition - Google Patents

Description

  The present invention relates to a curable composition.

BACKGROUND ART Polyolefins such as polypropylene and polyethylene are widely used for interior and exterior parts of automobiles, exterior parts of electric equipment, daily necessities, etc. because of their excellent moldability and solvent resistance.
However, since polyolefin is a non-polar resin, there is a problem in that it has low affinity with an adhesive, which is a polar substance, and is difficult to adhere.
Therefore, various adhesives with improved adhesion to polyolefin have been proposed.

For example, a vinyl ether-based resin composition containing a vinyl ether monomer having two or more vinyl ether groups, a compound having a urethane skeleton and having a vinyl ether group at a terminal, and a cationic photopolymerization initiator has been proposed (for example, Patent Document 1).
In addition, as an adhesive having improved adhesiveness to polyolefin by improving elongation properties, it contains a vinyl ether urethane compound having a specific structure, a thiol compound, and a monofunctional (meth) acryl monomer having a cyclic structure. (See, for example, Patent Document 2).
Furthermore, a resin composition containing a vinyl ether compound, a polyester elastomer, and a cationic photopolymerization initiator has been proposed (for example, see Patent Document 3).

JP 2013-053297 A JP 2015-165018 A JP-A-7-228842

  By the way, when the adherend is a polyolefin, the adherend and the adhesive are easily separated by impact. Therefore, in addition to the conventional adhesive strength (so-called peel strength measured by a 180 ° peel test), the adhesive used for bonding the polyolefin is required to have shear adhesive strength.

With respect to the above points, in the conventional adhesives including the adhesives described in Patent Documents 1 to 3, the problem of peeling due to impact, which may occur when a polyolefin is used as an adherend, has not been particularly considered. Was.
For example, in the adhesive described in Patent Literature 2, the adhesive force is improved by increasing flexibility and improving elongation characteristics. The body easily peels off and is vulnerable to impact.

  The present invention has been made in view of the above circumstances, and has as its object to provide a curable composition having excellent impact resistance when a non-polar resin such as polyolefin is used as an adherend.

Specific means for solving the problems include the following aspects.
<1> A curable composition comprising a urethane compound having two or more vinyl ether groups in a molecule, a thiol compound having two or more thiol groups in a molecule, a polyester resin, and a radical generator.

  <2> The curable composition according to <1>, wherein the urethane compound is a compound represented by the following formula (1).

Wherein, -X ¹ - and -X ² - are each _{independently, -C 4 H 8 -, -} C 2 H 4 -, - C 2 H 4 OC 2 H 4 -, - C 2 H 4 OC _{2 H 4 OC 2 H 4 -} , - C 3 H 6 -, - C 3 H 6 OC 3 H 6 -, - C 3 H 6 OC 3 H 6 OC 3 H 6 -, or the formula (2) below Represents any of the linking groups represented. -Z- represents a linking group represented by the following formula (3). L represents at least one skeleton selected from an ester skeleton, a caprolactone skeleton, an ether skeleton, and a carbonate skeleton. ]

  <3> The curable composition according to <1> or <2>, wherein the content of the polyester resin in the curable composition is 15 parts by mass or more and 240 parts by mass or less based on 100 parts by mass of the urethane compound.

  <4> The curable composition according to any one of <1> to <3>, wherein the polyester resin is a chlorinated polyester resin.

  <5> The curable composition according to any one of <1> to <4>, wherein the weight average molecular weight of the polyester resin is from 400 to 100,000.

  <6> The curable composition according to any one of <1> to <5>, which is used for adhesion to an olefin-based resin.

  According to the present invention, it is possible to provide a curable composition having excellent impact resistance when a non-polar resin such as polyolefin is used as an adherend.

  Hereinafter, specific embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and is implemented with appropriate modifications within the scope of the present invention. be able to.

In this specification, a numerical range indicated by using “to” means a range including numerical values described before and after “to” as a minimum value and a maximum value, respectively.
In the present specification, the amount of each component in the composition is, when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified, the total amount of the plurality of substances present in the composition. Means

[Curable composition]
The curable composition of the present invention comprises a urethane compound having two or more vinyl ether groups in a molecule (hereinafter, appropriately referred to as a "vinyl ether group-containing urethane compound") and a thiol compound having two or more thiol groups in a molecule. (Hereinafter, referred to as a “polyfunctional thiol compound”), a polyester resin, and a radical generator.

  A conventional pressure-sensitive adhesive containing a compound having a vinyl ether group has excellent adhesiveness (so-called interfacial adhesiveness) to a non-polar resin such as polyolefin as an adherend by increasing flexibility and improving elongation characteristics. Has been realized. On the other hand, since the above-mentioned pressure-sensitive adhesive is insufficient in hardness, when an excessive stress is applied, there is a problem that the adherend is easily peeled off and is weak against impact.

On the other hand, the curable composition of the present invention is excellent in impact resistance when a non-polar resin such as polyolefin is used as an adherend.
Although the reason why the curable composition of the present invention can exhibit such an effect is not clear, the present inventors speculate as follows.

Since the curable composition of the present invention contains a vinyl ether group-containing urethane compound, a polyfunctional thiol compound, and a radical generator, the curable composition exhibits the following curing reaction.
When the curable composition of the present invention is irradiated with light or heat, radicals are generated from the radical generator. By the generated radicals, the enethiol reaction between the vinyl ether group-containing urethane compound and the polyfunctional thiol compound proceeds, and a cured product having a network structure is formed. Since the curable composition of the present invention contains a urethane compound having a vinyl ether group that is a reactive group having a low polarity, a cured product having good affinity for a nonpolar resin such as polyolefin is formed. In addition, since the curable composition of the present invention contains a urethane compound having two or more vinyl ether groups in the molecule, the molecules are attracted to each other by the urethane skeleton at the time of curing, and the curing shrinkage is reduced and the curing is performed. The network structure of the object becomes dense (that is, the crosslink density increases), and the cohesive force increases. As a result, the curable composition of the present invention is considered to have excellent adhesion.

Since the polyester resin contained in the curable composition of the present invention does not contribute to the cross-linking reaction, the pores of the network structure formed by the reaction between the vinyl ether group-containing urethane compound and the polyfunctional thiol compound do not involve a chemical bond. It is thought to enter.
In other words, in the present invention, since the polyester resin having hardness enters the gaps of the network structure of the cured product exhibiting excellent adhesion to non-polar resins such as polyolefin, the excellent adhesiveness provided by the cured product is obtained. It is considered that the hardness of the cured product is increased, the shear adhesive strength is improved, and excellent impact resistance can be realized without being damaged.
Note that even if the vinyl ether group-containing urethane compound has a polyester skeleton, the above effects cannot be obtained.

<Urethane compound containing vinyl ether group>
The curable composition of the present invention contains a urethane compound having two or more vinyl ether groups in a molecule (vinyl ether group-containing urethane compound).
The vinyl ether group-containing urethane compound has two or more vinyl ether groups in the molecule, preferably two to four, and more preferably two or three.
In the curable composition of the present invention, since the vinyl ether group-containing urethane compound has two or more vinyl ether groups that are reactive groups having low polarity in the molecule, the affinity with a non-polar resin such as polyolefin is improved. The adhesiveness at the interface with the non-polar resin is excellent.

  As the vinyl ether group-containing urethane compound, a urethane compound represented by the following formula (1) is preferable. The urethane compound represented by the following formula (1) has a urethane bond [-NH (CO) O-] in its structure, and has vinyl ether groups at both ends of the molecule.

In the formula ^(1), -X 1 - and -X ² - are each _{independently, -C 4 H 8 -, -} C 2 H 4 -, - C 2 H 4 OC 2 H 4 -, - C 2 H _{4 OC 2 H 4 OC 2 H} 4 -, - C 3 H 6 -, - C 3 H 6 OC 3 H 6 -, - C 3 H 6 OC 3 H 6 OC 3 H 6 -, or the following formula (2 ) Represents any of the linking groups.
-Z- represents a linking group represented by the following formula (3).
L represents at least one skeleton selected from an ester skeleton, a caprolactone skeleton, an ether skeleton, and a carbonate skeleton.

  The linking group represented by the formula (2) has a cyclohexyl skeleton, and the linking group represented by the formula (3) has a skeleton derived from isophorone.

  The vinyl ether group-containing urethane compound is preferably at least one urethane compound selected from a urethane compound represented by the following formula (4) and a urethane compound represented by the following formula (5).

The vinyl ether group-containing urethane compound represented by the formula (4) has a carbonate skeleton as a repeating structure in the molecule. Incidentally, ^-X 1 in the formula ^{(4) -, - X 2} -, and -Z- is, ^-X 1 in the formula ^{(1) -, - X 2} -, and -Z- as synonymous.
The vinyl ether group-containing urethane compound represented by the formula (5) has an ether skeleton having three carbon atoms as a repeating structure in the molecule. Incidentally, ^-X 1 in the formula ^{(5) -, - X 2} -, and -Z- is, ^-X 1 in the formula ^{(1) -, - X 2} -, and -Z- as synonymous.

In the formula (4), l and n represent the number of repeating structural units. 1 and n each independently represent a positive integer, preferably 1 to 200, and more preferably 1 to 50 from the viewpoint of handling during synthesis.
In the formula (5), m represents the number of repeating structural units. m represents a positive integer, preferably 1 to 700, and more preferably 1 to 100 from the viewpoint of handling during synthesis.

The weight average molecular weight (Mw) of the vinyl ether group-containing urethane compound is not particularly limited. For example, the weight average molecular weight (Mw) of the urethane compound containing a vinyl ether group is preferably 50,000 or less, more preferably 10,000 or less, and even more preferably 5,000 or less.
The lower limit of the weight average molecular weight (Mw) of the vinyl ether group-containing urethane compound is not particularly limited, and is, for example, 800 or more.
When the weight average molecular weight (Mw) of the vinyl ether group-containing urethane compound is 50,000 or less, the shear adhesive strength of the cured product is further increased, so that the impact resistance is more excellent. Further, since the viscosity of the urethane compound containing a vinyl ether group does not become too high, the handleability is good.

  The weight average molecular weight (Mw) of the above-mentioned vinyl ether group-containing urethane compound is a value calculated by a standard polystyrene conversion method using the following gel permeation chromatography (GPC).

~conditions~
Measuring device: High-speed GPC device HLC-8220 GPC (Tosoh Corporation)
Detector: Differential refractometer (RI) RI-8220 (Tosoh Corporation)
Column: TSK-GEL GMHXL (use four) (Tosoh Corporation)
Column size: 7.8mmID × 30cm
Column temperature: 40 ° C
Eluent: tetrahydrofuran Sample concentration: 0.6 mg / mL
Injection volume: 100 μL
Flow rate: 0.8 mL / min

  The curable composition of the present invention may contain only one kind of urethane compound having a vinyl ether group, or may contain two or more kinds.

The content of the vinyl ether group-containing urethane compound in the curable composition of the present invention is preferably from 15% by mass to 70% by mass, more preferably from 25% by mass to 60% by mass, based on the total solid content of the curable composition. Preferably, it is more preferably from 35% by mass to 55% by mass.
When the content of the vinyl ether group-containing urethane compound in the curable composition is within the above range, adhesiveness and cohesion are obtained, and the impact resistance becomes more excellent.

(Synthesis method of urethane compound containing vinyl ether group)
The vinyl ether group-containing urethane compound includes at least a polyol compound having two or more hydroxy groups in a molecule (hereinafter, appropriately referred to as a “polyol compound”) and an isocyanate compound having two or more isocyanate groups in a molecule (hereinafter, referred to as “polyol compound”). It is appropriately synthesized from a “polyfunctional isocyanate compound”) and a monovinyl ether compound having a hydroxy group in the molecule (hereinafter, appropriately referred to as a “hydroxy group-containing monovinyl ether compound”).
The method for synthesizing the vinyl ether group-containing urethane compound is not particularly limited, and at least a polyol compound, a polyfunctional isocyanate compound, and a hydroxy group-containing monovinyl ether compound are used, and if necessary, a known polymerization catalyst is used. It can be synthesized by heating and mixing in the presence.
For example, a vinyl ether group-containing urethane compound can be suitably synthesized by the following method. However, the method for synthesizing the vinyl ether group-containing urethane compound in the present invention is not limited to the following method.

In a reaction vessel, a polyol compound, a polyfunctional isocyanate compound, and a polymerization catalyst such as dibutyltin dilaurate (DBTDL) are put, and the temperature of the contents in the reaction vessel is raised to 60 ° C. and reacted for 2 hours. The polymerization catalyst and the hydroxy group-containing monovinyl ether compound are charged into the reaction vessel after the reaction, and further reacted for 2 hours to synthesize a vinyl ether group-containing urethane compound. Completion of the reaction can be confirmed by the disappearance of the peak at 2250 cm ^-1 derived from isocyanate in the infrared absorption spectrum (IR).
Hereinafter, the polyol compound, the polyfunctional isocyanate compound, and the hydroxy group-containing monovinyl ether compound will be described in detail.

-Polyol compound-
The polyol compound in the present invention is not particularly limited as long as it is a polyol compound having two or more hydroxy groups in a molecule.
Examples of the polyol compound include polycarbonate polyol, polyoxypropylene glycol, polycaprolactone polyol, polyester polyol, polytetramethylene ether glycol, and polyoxyethylene-bisphenol A ether.
In the synthesis of the urethane compound containing a vinyl ether group, the polyol compound may be used alone or in combination of two or more.

  The number of hydroxy groups in the molecule of the polyol compound is preferably 2 to 4, more preferably 2 or 3, from the viewpoint of handling during synthesis.

The number average molecular weight of the polyol compound is preferably less than 3,000, more preferably 100 or more and 2,000 or less, and still more preferably 300 or more and 1,000 or less.
When the number average molecular weight of the polyol compound is less than 3,000, the attraction between molecules of the synthesized vinyl ether group-containing urethane compound due to the urethane skeleton in the curable composition becomes stronger, and curing shrinkage is further reduced. Therefore, the adhesiveness to the adherend becomes more excellent.

The number average molecular weight (Mn) of the above polyol compound is a value calculated by a standard polystyrene conversion method using the following gel permeation chromatography (GPC).
As described later, a commercially available product can be used as the polyol compound. When the polyol compound is a commercial product, the catalog data of the commercial product is preferentially adopted.

~conditions~
Measuring device: High-speed GPC device HLC-8220 GPC (Tosoh Corporation)
Detector: Differential refractometer (RI) RI-8220 (Tosoh Corporation)
Column: TSK-GEL GMHXL (use four) (Tosoh Corporation)
Column size: 7.8mmID × 30cm
Column temperature: 40 ° C
Eluent: tetrahydrofuran Sample concentration: 0.6 mg / mL
Injection volume: 100 μL
Flow rate: 0.8 mL / min

The polyol compound preferably has an alkyl group having 1 to 4 carbon atoms in the molecule. Examples of the alkyl group having 1 to 4 carbon atoms include a linear group such as a methyl group having 1 carbon atom, an ethyl group having 2 carbon atoms, and a 1-propyl group having 3 carbon atoms [— (CH ₂ ) ₂ —CH ₃ ]. In addition to the alkyl group, a branched alkyl group such as a 1-methylethyl group having 3 carbon atoms [—CH (CH ₃ ) ₂ ] and the like can be mentioned. When the polyol compound has an alkyl group having 1 to 4 carbon atoms in the molecule, the alkyl group is more preferably a methyl group.
When the polyol compound has a methyl group in the molecule, the affinity of the curable composition with a nonpolar resin such as a polyolefin is further improved, and the adhesiveness is further improved.

The polyol compound more preferably has a branched alkyl group in the molecule.
When the polyol compound has a branched alkyl group in the molecule, the affinity of the curable composition with a non-polar resin such as polyolefin is further improved, and the adhesiveness is further improved.

Commercially available products may be used as the polyol compound.
Examples of commercially available polyol compounds include Praxel® CD205PL (Mn = 500, catalog value), CD210 (Mn = 1,000, catalog value), CD220PL (Mn = 2,000, catalog value), etc. [ All are trade names, Daicel Corporation), Sannics (registered trademark) PP-400 (Mn = 400, catalog value), PP-1000 (Mn = 1,000, catalog value), PP-2000 (Mn = 2 [All, trade name, Sanyo Chemical Industries, Ltd.], Uniol (registered trademark) DA-700 [trade name, NOF CORPORATION, Mn = 700, catalog value], Kuraray polyol P -510 [trade name, Kuraray Co., Ltd., Mn = 500, catalog value], Praxel (registered trademark) 205U [trade name, Daicel Corp., Mn = 530, Catalog value], PTMG650 [trade name, Mitsubishi Chemical Corporation, Mn = 650, catalog value], and the like.

-Polyfunctional isocyanate compound-
The polyfunctional isocyanate compound in the present invention is not particularly limited as long as it has two or more isocyanate groups in the molecule.
Examples of the polyfunctional isocyanate compound include a diisocyanate compound having two isocyanate groups in a molecule, a triisocyanate compound having three isocyanate groups in a molecule, and a tetraisocyanate compound having four isocyanate groups in a molecule.

Examples of the diisocyanate compound include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate (H6XDI), naphthalene diisocyanate ( NDI), norbornene diisocyanate (NBDI), tetramethylxylene diisocyanate (TMXDI), dicyclohexylmethane 4,4′-diisocyanate (H12MDI), trimethylhexamethylene diisocyanate (TMDI) and the like.
Examples of the triisocyanate compound include triphenylmethane triisocyanate and 1-methylbenzol-2,4,6-triisocyanate.
Examples of the tetraisocyanate compound include dimethyltriphenylmethanetetraisocyanate.

Among them, polyfunctional isocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, naphthalene diisocyanate, norbornene diisocyanate, tetramethyl xylene diisocyanate, dicyclohexyl methane 4, At least one compound selected from 4′-diisocyanate and trimethylhexamethylene diisocyanate is preferable, and a polyol compound and a hydroxy group-containing monovinyl ether compound react favorably, and a linear vinyl ether group-containing urethane compound is efficiently produced. From the viewpoint of being synthesized, isophorone diisocyanate is more preferable.
In the synthesis of the vinyl ether group-containing urethane compound, a polyfunctional isocyanate compound may be used alone or in combination of two or more.

The polyfunctional isocyanate compound preferably has an alkyl group having 1 to 4 carbon atoms in the molecule. Examples of the alkyl group having 1 to 4 carbon atoms include a linear group such as a methyl group having 1 carbon atom, an ethyl group having 2 carbon atoms, and a 1-propyl group having 3 carbon atoms [— (CH ₂ ) ₂ —CH ₃ ]. In addition to the alkyl group, a branched alkyl group such as a 1-methylethyl group having 3 carbon atoms [—CH (CH ₃ ) ₂ ] and the like can be mentioned. When the polyfunctional isocyanate compound has an alkyl group having 1 to 4 carbon atoms in the molecule, the alkyl group is more preferably a methyl group.
When the polyfunctional isocyanate compound has a methyl group in the molecule, the affinity of the curable composition with a non-polar resin such as polyolefin is further improved, and the adhesiveness is further improved.
Examples of the polyfunctional isocyanate compound having a methyl group in the molecule include tolylene diisocyanate, isophorone diisocyanate, tetramethyl xylene diisocyanate, trimethyl hexamethylene diisocyanate, 1-methyl benzol-2,4,6-triisocyanate, dimethyl triphenyl methane tetraisocyanate. And isocyanate.

The polyfunctional isocyanate compound more preferably has a branched alkyl group in the molecule.
When the polyfunctional isocyanate compound has a branched alkyl group in the molecule, the affinity of the curable composition with a nonpolar resin such as a polyolefin is further improved, and the adhesiveness is further improved.
Examples of the polyfunctional isocyanate compound having a branched alkyl group in the molecule include isophorone diisocyanate, dicyclohexylmethane 4,4′-diisocyanate and the like.

  The amount of the polyfunctional isocyanate compound to be used is preferably 1.5 mol to 2.5 mol, more preferably 1.8 mol to 2.2 mol, per 1 mol of the polyol compound.

-Hydroxy group-containing monovinyl ether compound-
The hydroxy group-containing monovinyl ether compound in the present invention is not particularly limited as long as it is a monovinyl ether compound having a hydroxy group in a molecule.
Examples of the hydroxy group-containing monovinyl ether compound include 2-hydroxyethyl vinyl ether (HVE), 2-hydroxypropyl vinyl ether (HPVE), 4-hydroxybutyl vinyl ether (HBVE), 4-hydroxymethylcyclohexylmethyl vinyl ether, and diethylene glycol monovinyl ether (DEGMVE). , Triethylene glycol monovinyl ether (TEGDVE), dipropylene glycol monovinyl ether (DPGMVE) and the like.
In the synthesis of the vinyl ether group-containing urethane compound, the hydroxy group-containing monovinyl ether compound may be used alone or in combination of two or more.

The hydroxy group-containing monovinyl ether compound preferably has an alkyl group having 1 to 4 carbon atoms in the molecule. Examples of the alkyl group having 1 to 4 carbon atoms include a linear group such as a methyl group having 1 carbon atom, an ethyl group having 2 carbon atoms, and a 1-propyl group having 3 carbon atoms [— (CH ₂ ) ₂ —CH ₃ ]. In addition to the alkyl group, a branched alkyl group such as a 1-methylethyl group having 3 carbon atoms [—CH (CH ₃ ) ₂ ] and the like can be mentioned.
When the hydroxy group-containing monovinyl ether compound has an alkyl group having 1 to 4 carbon atoms in the molecule, the alkyl group is more preferably a methyl group having 1 carbon atom.
When the hydroxy group-containing monovinyl ether compound has a methyl group in the molecule, the affinity of the curable composition with a non-polar resin such as polyolefin is further improved, and the adhesiveness is further improved.

When the hydroxy group-containing monovinyl ether compound has a hydroxyalkyl group in the molecule, the hydroxyalkyl group may be linear or branched.
When the hydroxy group-containing monovinyl ether compound has a linear hydroxyalkyl group in the molecule, the number of carbon atoms in the carbon chain of the hydroxyalkyl group is preferably from 1 to 4, more preferably from 1 to 3, and from 1 to 2. More preferably, 2 is particularly preferred.
When the carbon number of the carbon chain of the linear hydroxyalkyl group is within the above range, the attraction of molecules of the synthesized vinyl ether group-containing urethane compound due to the urethane skeleton in the curable composition becomes stronger, and the Since the shrinkage is further alleviated, the adhesiveness becomes more excellent.

When the hydroxy group-containing monovinyl ether compound has a branched hydroxyalkyl group in the molecule, the number of carbon atoms in the carbon chain of the hydroxyalkyl group is preferably from 3 to 6, and particularly preferably 3.
When the hydroxyalkyl group is branched, the curability of the curable composition with a nonpolar resin such as polyolefin is further improved, and the adhesiveness is further improved.
Examples of the monovinyl ether compound having a branched hydroxyalkyl group in the molecule include 2-hydroxypropyl vinyl ether and dipropylene glycol monovinyl ether.
In addition, among the polyol compound, the polyfunctional isocyanate compound, and the hydroxy group-containing monovinyl ether compound, the hydroxy group-containing monovinyl ether compound more preferably has an alkyl group having 1 to 4 carbon atoms in the molecule.

  The amount of the hydroxy group-containing monovinyl ether compound to be used is preferably 1.5 mol to 2.5 mol, more preferably 1.8 mol to 2.2 mol, per 1 mol of the polyol compound.

-Other components-
In the method for synthesizing the vinyl ether group-containing urethane compound, other components may be used, if necessary, in addition to the polyol compound, the polyfunctional isocyanate compound, and the hydroxy group-containing monovinyl ether compound.
Other components include a polymerization catalyst, a diluent and the like.

As the polymerization catalyst, triethylamine, tetramethylethylenediamine, triethylenediamine (TEDA), bis (N, N-dimethylamino-2-ethyl) ether, N, N, N ′, N′-tetramethylhexamethylenediamine, bis ( Examples thereof include amine catalysts such as 2-dimethylaminoethyl) ether, carboxylic acid metal salts such as potassium acetate and potassium octylate, and organic metal compounds such as dibutyltin dilaurate.
Among these, dibutyltin dilaurate is preferred as the polymerization catalyst.
In the synthesis of a vinyl ether group-containing urethane compound, a polymerization catalyst may be used alone or in combination of two or more.

  The amount of the polymerization catalyst used is preferably 0.01 parts by mass to 0.3 parts by mass, and more preferably 0.05 parts by mass, based on 100 parts by mass of the total of the polyol compound, the polyfunctional isocyanate compound and the hydroxy group-containing monovinyl ether compound. -0.1 parts by mass is more preferred.

<Polyfunctional thiol compound>
The curable composition of the present invention contains a thiol compound having two or more thiol groups in a molecule (a polyfunctional thiol compound).
The polyfunctional thiol compound contributes to curing of the curable composition of the present invention.
The curable composition of the present invention is cured by the progress of the enethiol reaction between the above-described urethane compound having a vinyl ether group and the polyfunctional thiol compound.

The polyfunctional thiol compound in the present invention is not particularly limited as long as it is a thiol compound having two or more thiol groups in a molecule.
Examples of the polyfunctional thiol compound include bifunctional thiol compounds such as tetraethylene glycol bis (3-mercaptopropionate) and 1,4-bis (3-mercaptobutyryloxy) butane, and trimethylolpropane tris (3-mercaptopropionate). Pionate), tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate, 1,3,5-tris (3-mercaptobutyryloxyethyl) -1,3,5-triazine-2,4. Trifunctional thiol compounds such as 6 (1H, 3H, 5H) -trione, trimethylolpropane tris (3-mercaptobutyrate), trimethylolethanetris (3-mercaptobutyrate), and pentaerythritol tetrakis (3-mercaptopropio) Penta), pentaerythritol tetrakis (3-me Mercaptobutyrate) tetrafunctional thiol compounds such as dipentaerythritol hexakis (3-mercaptopropionate) hexafunctional thiol compound such as and the like.
Among these, as the polyfunctional thiol compound, from the viewpoint of solvent resistance, at least one selected from a trifunctional thiol compound and a tetrafunctional thiol compound is preferable, and a tetrafunctional thiol compound is more preferable.

As the polyfunctional thiol compound, commercially available products may be used.
Examples of commercially available polyfunctional thiol compounds include Karenz MT (registered trademark) BD [trade name, bifunctional thiol compound, 1,4-bis (3-mercaptobutyryloxy) butane, Showa Denko KK], Karenz MT (registered trademark) NR (trade name, trifunctional thiol compound, 1,3,5-tris (3-mercaptobutyryloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H , 5H) -Trione, Showa Denko KK], Karenz MT (registered trademark) PE1 [trade name, 4-functional thiol compound, pentaerythritol tetrakis (3-mercaptobutyrate), Showa Denko KK], EGMP-4 [Trade name, bifunctional thiol compound, tetraethylene glycol bis (3-mercaptopropionate), SC Organic Chemical Co., Ltd.], TMMP [trade name, trifunctional All compounds, trimethylolpropane tris (3-mercaptopropionate, SC Organic Chemical Co., Ltd.), TEMPIC [trade name, trifunctional thiol compound, tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate, SC Organic Chemical Co., Ltd.], PEMP [trade name, 4-functional thiol compound, pentaerythritol tetrakis (3-mercaptopropionate), SC Organic Chemical Co., Ltd.], DPMP [trade name, hexafunctional thiol compound, dipentane Erythritol hexakis, (3-mercaptopropionate), SC Organic Chemical Co., Ltd.] and the like.

  The curable composition of the present invention may contain only one type of polyfunctional thiol compound, or may contain two or more types.

The content of the polyfunctional thiol compound in the curable composition of the present invention is preferably 5 parts by mass to 100 parts by mass, more preferably 10 parts by mass to 50 parts by mass, based on 100 parts by mass of the vinyl ether group-containing urethane compound. , 15 parts by mass to 35 parts by mass is more preferred.
When the content of the polyfunctional thiol compound in the curable composition is 5 parts by mass or more with respect to 100 parts by mass of the vinyl ether group-containing urethane compound, the curable composition has a sufficient cross-linking point and has a sufficient aggregation. Since a force is obtained, the adhesiveness at the interface with the adherend becomes better.
When the content of the polyfunctional thiol compound in the curable composition is 100 parts by mass or less with respect to 100 parts by mass of the vinyl ether group-containing urethane compound, an increase in the polarity of the curable composition due to the influence of the polyfunctional thiol compound occurs. As a result, the adhesiveness to a non-polar resin such as polyolefin becomes better.

In the curable composition of the present invention, the ratio of the equivalent number of the thiol group of the polyfunctional thiol compound to the equivalent number of the vinyl ether group of the vinyl ether group-containing urethane compound (the equivalent number of the vinyl ether group of the vinyl ether group-containing urethane compound) : Equivalent number of thiol groups of the polyfunctional thiol compound) is preferably 1: 0.5 to 1: 1.5, more preferably 1: 0.7 to 1: 1.3, More preferably, the ratio is 1: 0.9 to 1: 1.1.
When the ratio between the number of equivalents of the thiol group of the polyfunctional thiol compound and the number of equivalents of the vinyl ether group of the vinyl ether group-containing urethane compound is within the above range, the adhesive force due to the unreacted polyfunctional thiol compound. And the decrease in cohesive force due to the decrease in the number of crosslinking points is suppressed, so that the adhesiveness at the interface with the adherend becomes better.

<Polyester resin>
The curable composition of the present invention contains a polyester resin.
In the curable composition of the present invention, the polyester resin enters the gaps of the network structure formed by the enethiol reaction between the vinyl ether group-containing urethane compound and the polyfunctional thiol compound, so that the hardness of the cured product is increased and the impact resistance is increased. improves.

The type of the polyester resin in the present invention is not particularly limited.
As the polyester resin, a synthetic product may be used, or a commercially available product may be used.
The polyester resin is obtained by, for example, using a dicarboxylic acid component and a diol component as raw materials and subjecting these components to polycondensation by a known method.

Examples of the dicarboxylic acid component include aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, and sebacic acid; alicyclic dicarboxylic acids such as norbornene dicarboxylic acid and cyclohexane dicarboxylic acid; terephthalic acid; and isophthalic acid. And dicarboxylic acids such as aromatic dicarboxylic acids such as phthalic acid and 1,4-naphthalenedicarboxylic acid, and ester derivatives thereof.
In the synthesis of the polyester resin, the dicarboxylic acid component may be used alone or in combination of two or more.

Examples of the diol component include aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, and 1,3-butanediol; and alicyclic diols such as cyclohexanedimethanol. And diol compounds such as aromatic diols such as bisphenol A, 1,3-benzenedimethanol, and 1,4-benzenedimethanol.
In the synthesis of the polyester resin, the diol component may be used alone or in combination of two or more.

The polyester resin may be an unmodified polyester resin or a modified polyester resin.
Examples of the modified polyester resin include a chlorinated polyester resin obtained by reacting chlorine with a polyester resin, and a polyester resin in which an acryloyl group is added to a polyester skeleton (a so-called polyester acrylate).
For example, chlorinated polyester resins are preferred because they can increase the shear adhesion of the curable composition with a relatively small amount.

The weight average molecular weight (Mw) of the polyester resin is not particularly limited.
For example, the weight average molecular weight (Mw) of the polyester resin is preferably 400 or more and 100,000 or less, more preferably 700 or more and 50,000 or less, and further preferably 1,000 or more and 10,000 or less.
When the weight average molecular weight (Mw) of the polyester resin is 400 or more, the resin enters the gaps of the network structure formed by the enethiol reaction between the vinyl ether group-containing urethane compound and the polyfunctional thiol compound, so that the hardness of the cured product increases, The impact properties are better.
When the weight average molecular weight (Mw) of the polyester resin is 100,000 or less, the compatibility with other components is good, and the impact resistance becomes more excellent.

  The above-mentioned weight average molecular weight (Mw) of the polyester resin is a value calculated by the same method as the above-mentioned weight average molecular weight (Mw) of the vinyl ether group-containing urethane compound.

  Examples of commercially available polyester resins include EBECRYL (registered trademark) 436 [trade name, chlorinated polyester / trimethylolpropane triacrylate (mass ratio) = 60/40, weight average molecular weight: 5,000, Daicel Ornex ( EBECRYL (registered trademark) 438 [trade name, chlorinated polyester / glycerol propoxy triacrylate (mass ratio) = 60/40, weight average molecular weight: 5,000, Daicel Ornex Co., Ltd.], EBECRYL (registered trademark) Trademark) 800 [trade name, polyester acrylate, weight average molecular weight: 780, Daicel Ornex Co., Ltd.], EBECRYL (registered trademark) 446 [trade name, chlorinated polyester / trimethylolpropane triacrylate (mass ratio) = 68 / 32, weight average molecular weight: 4, 00, Daicel Ornex Co., Ltd.], EBECRYL (registered trademark) 524 (trade name, polyester / 1,6-hexanediol diacrylate (mass ratio) = 70/30, weight average molecular weight: 1,000, Daicel Ornex) Co., Ltd.), EBECRYL (registered trademark) 525 [trade name, polyester / dipropylene glycol diacrylate (mass ratio) = 60/40, weight average molecular weight: 40,000, Daicel Ornex Co., Ltd.] and the like. .

  The curable composition of the present invention may include only one type of polyester resin, or may include two or more types of polyester resins.

The content of the polyester resin in the curable composition of the present invention is preferably 10 to 300 parts by mass, more preferably 15 to 240 parts by mass, based on 100 parts by mass of the vinyl ether group-containing urethane compound. Or less, more preferably 15 to 60 parts by mass.
When the content of the polyester resin in the curable composition is 10 parts by mass or more based on 100 parts by mass of the vinyl ether group-containing urethane compound, the polyester resin for securing hardness is sufficiently contained, and thus the curable composition Impact resistance is further improved.
When the content of the polyester resin in the curable composition is 300 parts by mass or less with respect to 100 parts by mass of the vinyl ether group-containing urethane compound, the polyester resin that secures the hardness ensures the affinity with the adherend. Since it is not too much with respect to the urethane compound containing a vinyl ether group, the curable composition is more excellent in the balance between the adhesion at the interface and the impact resistance.

<Radical generator>
The curable composition of the present invention contains a radical generator.
The curable composition of the present invention is cured by the progress of an enethiol reaction between a vinyl ether group-containing urethane compound and a polyfunctional thiol compound by a radical generated from a radical generator.

  The radical generator is not particularly limited, and any known radical generator can be used without limitation. Examples of the radical generator include a thermal radical generator (thermal polymerization initiator), a redox initiator, and a photoradical generator (photopolymerization initiator).

  Examples of the thermal radical generator include benzoyl peroxide, lauroyl peroxide, caproyl peroxide, di-n-propylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, t-butylperoxypivalate, and t-butylperoxypivalate. Organic peroxides such as butylperoxy-2-ethylhexanate, 2,2'-azobis-isobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 2,2'-azobis- An azo compound such as 4-methoxy-2,4-dimethylvaleronitrile is exemplified.

  Examples of the redox initiator include a combination of Permec N (trade name, methyl ethyl ketone peroxide, NOF CORPORATION) and cobalt naphthenate, Parkmill H (trade name, cumene hydroperoxide, NOF CORPORATION) and pentoxide Combination with vanadium, Niper BMT [trade name, di (3-methylbenzoyl) peroxide + benzoyl (3-methylbenzoyl) peroxide + dibenzoyl peroxide, NOF Corporation] and dimethylaniline, nipper Combination of PMB (trade name, di (4-methylbenzoyl) peroxide, NOF CORPORATION) with dimethylaniline, and combination of Niper BW (trade name, dibenzoyl peroxide, NOF CORPORATION) with dimethylaniline Combinations and the like can be mentioned.

Examples of the photo radical generator include a benzoin derivative compound, a benzyl ketal compound, an α-hydroxyacetophenone compound, a thioxanthone compound, and an acylphosphine oxide compound.
Specifically, as the photo-radical generator, 1-hydroxycyclohexyl phenyl ketone [trade name: Irgacure 184, BASF Japan Ltd.], 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl ] Propanol oligomer [trade name: Esacure ONE, Lamberti Co., Ltd.], 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one [trade name: Irgacure] 2959, BASF Japan Ltd.], 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one [product Name: Irgacure 127, BASF Japan Ltd.], 2,2-Dimethoxy-2-phenylacetophenone Name: Irgacure 651, BASF Japan Ltd.], 2-hydroxy-2-methyl-1-phenyl-propan-1-one [trade name: Darocure 1173, BASF Japan Ltd.], 2-methyl-1- [ (4-Methylthio) phenyl] -2-morpholinopropan-1-one [trade name: Irgacure 907, BASF Japan Ltd.], 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone -1,2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenyl Phosphine oxide, bis (2,6-dimethoate) Shibenzoiru) -2,4,4-trimethyl pentyl phosphine oxide and the like.

  Among these, a photo-radical generator is preferable as the radical generator from the viewpoint of easy operation. Further, as the photoradical generator, α-hydroxyacetophenone compounds are preferred from the viewpoint that they have good compatibility with the vinyl ether group-containing urethane compound, hardly cause yellowing of the curable composition, and have little odor. And 1-hydroxycyclohexyl phenyl ketone are particularly preferred.

  The curable composition of the present invention may contain only one type of radical generator, or may contain two or more types.

When the curable composition of the present invention contains a photo-radical generator as a radical generator, the content of the photo-radical generator in the curable composition includes a vinyl ether group-containing urethane compound, a polyfunctional thiol compound, and a vinyl ether group-containing 0.1 part by mass to 20 parts by mass, preferably 0.5 parts by mass to 10 parts by mass, more preferably 1 part by mass to 100 parts by mass of the compound having an ethylenically unsaturated bond other than the urethane compound. 7 parts by mass is more preferred.
The content of the photo-radical generator in the curable composition is 0 with respect to 100 parts by mass of a total of a vinyl ether group-containing urethane compound, a polyfunctional thiol compound, and a compound having an ethylenically unsaturated bond other than the vinyl ether group-containing urethane compound. When the amount is more than 1 part by mass, the photocuring of the curable composition proceeds sufficiently during light irradiation, and thus poor curing hardly occurs.
The content of the photo-radical generator in the curable composition is based on a total of 100 parts by mass of a vinyl ether group-containing urethane compound, a polyfunctional thiol compound, and a compound having an ethylenically unsaturated bond other than the vinyl ether group-containing urethane compound. When the amount is 20 parts by mass or less, the photo-radical generator does not excessively absorb light, so that poor curing of the curable composition hardly occurs. Further, the photo-radical generator hardly precipitates over time, and the storage stability of the curable composition becomes better.

<Other components>
The curable composition of the present invention contains a vinyl ether group-containing urethane compound, a polyfunctional thiol compound, a polyester resin, and other components other than the radical generator, if necessary, as long as the effects of the present invention are not impaired. May be.
Other components include compounds having an ethylenically unsaturated bond other than a vinyl ether group-containing urethane compound, a polymerization inhibitor, a sensitizer, an antioxidant, a flame retardant, an antistatic agent, a leveling agent, a defoaming agent, Various additives such as pigments are included.

  Examples of the compound having an ethylenically unsaturated bond other than the vinyl ether group-containing urethane compound include a polyfunctional acrylate having two or more acryloyl groups. Examples of such polyfunctional acrylates include 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, and polytetraethylene glycol diacrylate. Acrylate, tricyclodecane dimethanol diacrylate, ethoxylated bisphenol A diacrylate, alkoxylated glycerin triacrylate, trimethylolpropane triacrylate, alkoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, alkoxylated pentaerythritol triacrylate, glycerin Propoxy triacrylate, pentaerythritol tetraacrylate Alkoxylated pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, and dipentaerythritol hexaacrylate.

  Examples of the polymerization inhibitor include methylhydroquinone, t-butylhydroquinone, 4-methoxynaphthol, 1,4-benzoquinone, methoquinone, dibutylhydroxytoluene, N-nitrosophenylhydroxyalkylamine aluminum salt, 1,4-naphthoquinone and 4-hydroxy -2,2,6,6-tetramethylpiperidine 1-oxyl (4-hydroxy TEMPO) and the like.

[Application]
The curable composition of the present invention exhibits a high shear adhesive force of, for example, 1 MPa or more, and is excellent in impact resistance, and thus can be suitably used as an adhesive. The curable composition of the present invention is excellent not only in polar substances such as metal, glass, porcelain, wood, and ceramics, but also has excellent impact resistance when a non-polar resin is used as an adherend. It can be suitably used for adhesion.

The curable composition of the present invention can be suitably used for adhesion between a polar substance and a nonpolar resin and between nonpolar resins.
Further, the curable composition of the present invention can be suitably used as an adhesive for labels, stickers and the like of various products. When the curable composition of the present invention is used as an adhesive for labels, stickers, and the like of various products, for example, the curable composition of the present invention is applied on various resin films made of olefin-based resins, acrylic-based resins, and the like. Is applied, and the application surface is attached to various adherends, and then, by irradiating light, labels, stickers, and the like can be adhered to the commodity as the adherend.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following examples as long as the gist is not exceeded.

  The weight average molecular weight (Mw) of the urethane compound produced in this example was measured by the method described above.

-Production of urethane compounds-
[Production Example 1]
In a reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, Sannics (registered trademark) PP-400 (polyoxypropylene glycol (m = 7) represented by the following structural formula (a), number average) Molecular weight (Mn) = 400 (catalog value), 100 parts by mass of Sanyo Chemical Industry Co., Ltd., 112 parts by mass of isophorone diisocyanate (IPDI), and 0.03 part by mass of dibutyltin dilaurate (DBTDL) are added and stirred. The temperature of the contents of the reaction vessel was raised to 60 ° C., and the reaction was carried out for 2 hours. Thereafter, 0.20 parts by mass of dibutyltin dilaurate (DBTDL) and 56 parts by mass of 4-hydroxybutyl vinyl ether (HBVE) are charged, and the mixture is further reacted for 2 hours, to thereby obtain a urethane compound having vinyl ether groups at both ends of a molecular chain. (Hereinafter, referred to as "vinyl ether urethane compound (A)"). The completion of the reaction was confirmed by the disappearance of the peak at 2250 cm ^-1 derived from isocyanate in the infrared absorption spectrum (IR).
When the weight average molecular weight (Mw) of the obtained vinyl ether urethane compound (A) was measured, it was 2,200.
Incidentally, vinyl urethane compound (A) is a compound represented by the above formula (5), -X ¹ in the formula (5) is _-C 4 _{H 8} - and is, -X ² is - C ₄ H ₈ —, —Z— is a linking group represented by the formula (3), and m is 7.

[Production Example 2]
In a reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, Sannicks® PP-400 (polyoxypropylene glycol (m = 7) represented by the structural formula (a) described above, An average molecular weight (Mn) = 400 (catalog value), 100 parts by mass of Sanyo Chemical Industry Co., Ltd., 112 parts by mass of isophorone diisocyanate (IPDI), and 0.03 parts by mass of dibutyltin dilaurate (DBTDL) were added and stirred. Below, the temperature of the contents of the reaction vessel was raised to 60 ° C. and reacted for 2 hours. Thereafter, 0.20 parts by mass of dibutyltin dilaurate (DBTDL) and 43 parts by mass of 2-hydroxyethyl vinyl ether (HVE) are added, and the mixture is further reacted for 2 hours, so that a urethane compound having vinyl ether groups at both ends of the molecular chain. (Hereinafter, referred to as "vinyl ether urethane compound (B)"). The completion of the reaction was confirmed by the disappearance of the peak at 2250 cm ^-1 derived from isocyanate in the infrared absorption spectrum (IR).
When the weight average molecular weight (Mw) of the obtained vinyl ether urethane compound (B) was measured, it was 2,100.
Incidentally, vinyl urethane compound (B) is a compound represented by the above formula (5), -X ¹ in the formula (5) is _-C 2 _{H 4} - a and, -X ² is - C ₂ H ₄ —, —Z— is a linking group represented by the formula (3), and m is 7.

[Production Example 3]
In a reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, Praxel® 205U (polycaprolactone diol (l, n = 2) represented by the following structural formula (c), number average molecular weight ( (Mn) = 530 (catalog value, Daicel Co., Ltd.) 100 parts by mass, 89 parts by mass of isophorone diisocyanate (IPDI), and 0.03 parts by mass of dibutyltin dilaurate (DBTDL), and the above reaction vessel under stirring. Was heated to 60 ° C. and reacted for 2 hours. Thereafter, 0.16 parts by mass of dibutyltin dilaurate (DBTDL) and 44 parts by mass of 4-hydroxybutyl vinyl ether (HBVE) are added, and the mixture is further reacted for 2 hours to have a polyester skeleton and both molecular chains. A urethane compound having a vinyl ether group at a terminal (hereinafter, referred to as "vinyl ether urethane compound (C)") was obtained. The completion of the reaction was confirmed by the disappearance of the peak at 2250 cm ^-1 derived from isocyanate in the infrared absorption spectrum (IR).
When the weight average molecular weight (Mw) of the obtained vinyl ether urethane compound (C) was measured, it was 2,900.

-Production of curable composition-
[Example 1]
100 parts by mass of the vinyl ether urethane compound (A) obtained in Production Example 1 above and Irgacure (registered trademark) 184 as a radical generator [photoradical generator, 1-hydroxycyclohexyl phenyl ketone, BASF Japan Ltd. )] And 3.75 parts by mass were weighed into a brown sample bottle, heated at 60 ° C. for 20 minutes, and then stirred with a spatula for 5 minutes. Next, in a brown sample bottle after stirring, EBECRYL (registered trademark) 438 [chlorinated polyester / glycerol propoxy triacrylate (mass ratio) = 60/40, weight average molecular weight: 5,000, Daicel Ornex Co., Ltd.] Co., Ltd.) and 25 parts by mass of Karenz MT (registered trademark) PE1 which is a polyfunctional thiol compound [thiol compound having four thiol groups in the molecule (tetrafunctional thiol compound), pentaerythritol tetrakis (3-mercaptobutyrate) ), Showa Denko KK], 22.4 parts by mass, and heated at 40 ° C for 10 minutes, followed by stirring and mixing with a spatula for 5 minutes to obtain a curable composition of Example 1.

[Examples 2 to 7]
Except that the composition of the curable composition was changed to the composition shown in Table 1 below, the same operation as in Example 1 was performed to obtain the curable compositions of Examples 2 to 7.

[Comparative Examples 1 to 8]
Except that the composition of the curable composition was changed to the composition shown in Table 2 below, the same operation as in Example 1 was performed to obtain curable compositions of Comparative Examples 1 to 8.

<Measurement of shear adhesive strength>
As an index for evaluating the impact resistance of the curable composition, the shear adhesive strength was measured.
Two 25 mm-wide polypropylene plates (hereinafter referred to as “PP plates”) [trade name: PP-N-BN, Paltec Co., Ltd.] were prepared.
Each of the curable compositions of Examples 1 to 7 and Comparative Examples 1 to 8 was applied on a PP plate using an applicator so that the thickness after application was 30 μm, and another sheet was applied to the application surface. Were laminated to produce a sheet having the structure of PP plate / curable composition / PP plate. Next, the sheet was irradiated with light under the conditions of an illuminance of 150 mW / cm ² and an integrated amount of light of 500 mJ / cm ² to cure the curable composition to obtain a test piece.
Using a tensile tester (model number: RTF-1350, A & D Corporation), this test piece was bonded to the bonding surface under the conditions of 23 ° C. and 50% RH at a tensile speed of 10 mm / min. In parallel, the adhesive portion was pulled at a constant speed and a load was applied to break the adhesive portion, and the shear adhesive force (unit: MPa, maximum load when the adhesive portion was broken) was measured. The time required for the bonded portion to break was about 5 seconds.
When the shear adhesive strength is 1 MPa or more, it means that the resin has excellent impact resistance.

Table 1 shows the compositions of the curable compositions of Examples 1 to 7 and the measurement results of the shear adhesive strength. Table 2 shows the compositions of the curable compositions of Comparative Examples 1 to 8 and the measurement results of the shear adhesive strength.
In Tables 1 and 2, "-" means that the corresponding component was not blended.

Details of the components in Tables 1 and 2 are as follows.
<Vinyl ether urethane compound>
(A): Vinyl ether urethane compound obtained in Production Example 1 above (B): Vinyl ether urethane compound obtained in Production Example 2 above (C): Vinyl ether urethane compound obtained in Production Example 3 above <Polyester Resin>
EBECRYL (registered trademark) 438: chlorinated polyester / glycerin propoxy triacrylate (OTA480) (mass ratio) = 60/40, weight average molecular weight: 5,000, Daicel Ornex Co., Ltd.
EBECRYL (registered trademark) 436: chlorinated polyester / trimethylolpropane triacrylate (mass ratio) = 60/40, weight average molecular weight: 5,000, Daicel Ornex Co., Ltd.
EBECRYL (registered trademark) 800: polyester acrylate, weight average molecular weight: 780, Daicel Ornex Co., Ltd.

<Polyfunctional acrylate>
OTA480: glycerin propoxy triacrylate, weight average molecular weight: 480, Daicel Ornex Co., Ltd.
<Modified epoxy acrylate>
EBECRYL (registered trademark) 3708: weight average molecular weight: 1,500, Daicel Ornex Co., Ltd.
<Polyfunctional thiol compound>
Karenz MT (registered trademark) PE1: thiol compound having four thiol groups in the molecule (tetrafunctional thiol compound), pentaerythritol tetrakis (3-mercaptobutyrate), Showa Denko KK
<Radical generator>
Irgacure (registered trademark) 184: photo-radical generator, 1-hydroxycyclohexyl phenyl ketone, BASF Japan Ltd.

As shown in Table 1, urethane compounds having two or more vinyl ether groups in the molecule (urethane compounds containing a vinyl ether group), thiol compounds having two or more thiol groups in the molecule (polyfunctional thiol compounds), polyester resins, and It was suggested that the curable compositions of Examples 1 to 7 containing the radical generator exhibited sufficiently high shear adhesive strength and were excellent in impact resistance.
On the other hand, as shown in Table 2, the curable compositions of Comparative Examples 1 to 6 and 8, which do not contain at least one of a vinyl ether group-containing urethane compound, a polyfunctional thiol compound, and a polyester resin, have the curability of Examples. Compared with the composition, it was suggested that the shear adhesive strength was low and the impact resistance was poor. In addition, the curable composition of Comparative Example 7 containing no polyfunctional thiol compound did not cure even when irradiated with light, and the shear adhesive force could not be measured.

In the curable composition of Comparative Example 4 containing no acrylic resin but containing an acrylic resin, an improvement in shear adhesive strength was observed, but a shear adhesive strength exceeding 1 MPa was not obtained.
It was suggested that the curable composition of Comparative Example 5, which contained a vinyl ether group-containing urethane compound having a polyester skeleton and did not contain a polyester resin, had low shear adhesive strength and poor impact resistance.
According to the comparison of the curable compositions of Example 2, Comparative Example 1 and Comparative Example 3, the high shear adhesive strength observed in the curable composition of Example 2 is included in EBECRYL® 438. Glycerin propoxy triacrylate, but not chlorinated polyester.

Claims (6)

Seen containing a urethane compound having two or more vinyl ether groups in the molecule, a thiol compound having two or more thiol groups in a molecule, a polyester resin, a radical generator, a,
The polyester resin is, including the curable composition chlorinated polyester resin. The curable composition according to claim 1, wherein the urethane compound is a compound represented by the following formula (1).


Wherein, -X ¹ - and -X ² - are each _{independently, -C 4 H 8 -, -} C 2 H 4 -, - C 2 H 4 OC 2 H 4 -, - C 2 H 4 OC _{2 H 4 OC 2 H 4 -} , - C 3 H 6 -, - C 3 H 6 OC 3 H 6 -, - C 3 H 6 OC 3 H 6 OC 3 H 6 -, or the formula (2) below Represents any of the linking groups represented. -Z- represents a linking group represented by the following formula (3). L represents at least one skeleton selected from an ester skeleton, a caprolactone skeleton, an ether skeleton, and a carbonate skeleton. ]



  The curable composition according to claim 1, wherein the content of the polyester resin in the curable composition is from 15 parts by mass to 240 parts by mass with respect to 100 parts by mass of the urethane compound.   The curable composition according to any one of claims 1 to 3, wherein the polyester resin is a chlorinated polyester resin.   The curable composition according to any one of claims 1 to 4, wherein the polyester resin has a weight average molecular weight of 400 or more and 100,000 or less. The curable composition according to any one of claims 1 to 5, which is used for adhesion to an olefin-based resin.