KR20210103960A - Photocurable adhesive composition, film and optical component - Google Patents

Abstract

Disclosed is a photocurable adhesive composition including: a polymer including a first structural unit represented by the formula (1) and a second structural unit having a reactive group; and a monomer, wherein the polymer is dissolved in the monomer, and the monomer includes a polar (meth)acrylic compound. In the formula (1), R_1, R_2, R_3 and R_4 are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and n is 0, 1 or 2.

Description

Photocurable adhesive composition, film and optical component

The present invention relates to a photocurable adhesive composition, a film obtained by curing the photocurable adhesive, and an optical component comprising the film.

In recent years, with the demand for weight reduction, compactness and high density, replacement of optically transparent resins with optically transparent resins is progressing in the fields of optical components and display element components such as liquid crystals, in which inorganic glass has been conventionally used. With the replacement of such optical components with resins, further improvements in transparency, adhesion/adhesion properties, and the like are demanded also in adhesives used for manufacturing optical components.

For example, Patent Document 1 describes that a resin composition containing an organosilane compound and a silyl group-containing cyclic olefin polymer can be used as a transparent material as an adhesive for optical materials.

Japanese Patent Laid-Open No. 2002-146145

However, as a result of this inventor examining, the resin composition of patent document 1 WHEREIN: It became clear that there was room for improvement from a viewpoint of transparency and adhesiveness. An object of the present invention is to provide an adhesive composition that is excellent in transparency and adhesiveness and can be used in the manufacture of optical components.

The present inventors have found that an adhesive composition having excellent transparency and adhesiveness can be obtained by using a polymer containing a structural unit having a specific structure and a specific monomer in which the polymer is soluble, and completed the present invention.

According to the present invention,

A polymer comprising a first structural unit represented by Formula (1) and a second structural unit having a reactive group;

comprising a monomer;

the polymer is dissolved in the monomer,

The monomer comprises a polar acrylic compound,

A light curable adhesive composition is provided.

In formula (1),

R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and n is 0, 1 or 2.

In addition, according to the present invention, there is provided a film including a cured product of the photo-curable adhesive composition.

Further, according to the present invention, there is provided an optical component comprising the film as an adhesive layer.

ADVANTAGE OF THE INVENTION According to this invention, the photocurable adhesive composition which has high transparency and is excellent in adhesiveness, and therefore can be used as an adhesive agent in manufacture of an optical component is provided.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described. In addition, the notation "a to b" in description of a numerical range in this specification shows a more than b, unless otherwise stated. For example, "1-5 mass %" means "1 mass % or more and 5 mass % or less."

In the description of a group (atom group) in the present specification, the expression not describing whether it is substituted or unsubstituted includes both of not having a substituent and having a substituent. For example, "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

The notation with "(meth)acryl" in this specification shows the concept containing both acryl and methacryl. The same applies to similar notations such as "(meth)acrylate".

(Light Curable Adhesive Composition)

The photocurable adhesive composition of this embodiment (in the specification, it may simply be called "adhesive composition") is a polymer (spec Among them, "polymer P") and a monomer are included. The adhesive composition of this embodiment WHEREIN: The polymer P melt|dissolves in a monomer and exists.

In formula (1),

R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and n is 0, 1 or 2.

The adhesive composition of this embodiment is equipped with high crosslinking property (curability) because the polymer P contains a 1st structural unit and a 2nd structural unit, and therefore has excellent adhesion/adhesion property to an adherend. Moreover, in the adhesive composition of this embodiment, the polymer P melt|dissolves in the monomer, and the hardened|cured material has the outstanding transparency. As a result, the adhesive composition of this embodiment can be used suitably as an adhesive agent for manufacturing the optical component which coexistence of transparency and adhesiveness is calculated|required.

Hereinafter, each component used for the adhesive composition of this embodiment is demonstrated in detail.

(Polymer P)

The polymer P used for the photocurable adhesive composition of this embodiment contains the 1st structural unit represented by Formula (1), and the 2nd structural unit which has a reactive group. The first structural unit represented by formula (1) is chemically robust. Therefore, the cured film obtained from the polymer P containing a 1st structural unit is excellent in a moldability, and is equipped with durability.

1st structural unit represented by Formula (1) WHEREIN: n is 0, 1 or 2, Preferably it is 0 or 1, More preferably, it is 0.

In the first structural unit represented by Formula (1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, preferably an organic group having 1 to 18 carbon atoms. and more preferably an organic group having 1 to 10 carbon atoms. This organic group may have reactive functional groups, such as a carboxyl group, a glycidyl group, and an oxetanyl group. In addition, this organic group may contain one or more atoms selected from O (oxygen), N (nitrogen), S (sulfur), P (phosphorus), and Si (silicon).

Examples of the organic group having 1 to 30 carbon atoms include an alkyl group, alkenyl group, alkynyl group, alkylidene group, aryl group, aralkyl group, alkaryl group, cycloalkyl group and heterocyclic group having 1 to 30 carbon atoms.

In Formula (1), n is 0, 1 or 2, Preferably it is 0 or 1, More preferably, it is 0.

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group. , an octyl group, a nonyl group, and a decyl group. As an alkenyl group, an allyl group, a pentenyl group, and a vinyl group are mentioned, for example. An ethynyl group is mentioned as an alkynyl group. As an alkylidene group, a methylidene group and an ethylidene group are mentioned, for example. Examples of the aryl group include a tolyl group, a xylyl group, a phenyl group, a naphthyl group and an anthracenyl group. As an aralkyl group, a benzyl group and a phenethyl group are mentioned, for example. Examples of the cycloalkyl group include an adamantyl group, a cyclopentyl group, a cyclohexyl group and a cyclooctyl group. As a heterocyclic group, an epoxy group and oxetanyl group are mentioned, for example.

From the viewpoint of the cured product it will increase the light transmission properties of the resulting adhesive composition, preferably from R ₁ to R ₄ in which one hydrogen, and more preferably all of R ₁ to R ₄ are hydrogen.

The second structural unit constituting the polymer P has a reactive functional group, for example, a radically polymerizable reactive group capable of initiating radical polymerization by a photoradical generator. The polymer P including the second structural unit forms a crosslinked structure by a crosslinking reaction to form a resin film. Examples of the reactive group of the second structural unit include a vinyl group, a vinylidene group, an acryloyl group, a methacryloyl group, an epoxy group, a carboxyl group, and a hydroxyl group. Preferably, the reactive group is preferably an organic group containing a carbon-carbon double bond, and any group selected from the group consisting of a vinyl group, a vinylidene group, an acryloyl group and a methacryloyl group is more preferable.

As a 2nd structural unit, the structural unit represented by Formula (2) is mentioned, for example.

In Formula (2), R<_5> is a reactive group provided with radical polymerization which can start radical polymerization with an optical radical generating material, for example. Examples of such a reactive group include a vinyl group, a vinylidene group, an acryloyl group, a methacryloyl group, an epoxy group, a carboxyl group and a hydroxyl group. The reactive group is preferably an organic group containing a carbon-carbon double bond, and any group selected from the group consisting of a vinyl group, a vinylidene group, an acryloyl group and a methacryloyl group is more preferable.

As a preferable example of R<_5> , the organic group represented by Formula (I) and Formula (II) is mentioned.

In Formula (I), f is an integer of 1-9, In Formula (II), e is an integer of 1-9.

The polymer P which has a 2nd structural unit may also contain the structural unit represented by the following formula (3) or (4) containing the structural unit of Formula (2). In Formulas (3) and (4), R ₆ , R ₇ and R ₈ have the same definitions as R ₅ in Formula (2). However, if the polymer P containing the structural unit of the formula (4), R _7, either one of R ₈ is long as they have an above-mentioned reactive, and the other R ₁ to R ₄ in the formula (1) An organic group having 1 to 30 carbon atoms, which is synonymous with However, when the polymer P contains both structural units of formulas (3) and (4) _{, at least one of R 6} to R _{8 should} just have the above-described reactive group, and the remainder should be an organic group having 1 to 30 carbon atoms. also contribute.

Polymer P may further contain at least one of structural units represented by Formula (5), Formula (6), Formula (7), Formula (8), Formula (9), and Formula (10).

In Formulas (6), (7), and (10), R ₁₁ to R ₁₄ are an organic group having 1 to 30 carbon atoms, which is synonymous with _{R 1} to R ₄ in Formula (1).

The upper limit of Mw (weight average molecular weight) of the polymer P according to the present embodiment is, for example, 30000 or less, preferably 20000 or less, more preferably 14000 or less, still more preferably 10000 or less. Thereby, the mobility of polymer P is improved, and a more suitable crosslinked structure can be made. Moreover, the lower limit of Mw of polymer P is 1000 or more, for example, It is preferable to set it as 2000 or more, and it is more preferable to set it as 3000 or more. Thereby, when the adhesive composition containing polymer P is photocured, formation of a crosslinked structure is accelerated|stimulated.

The dispersion degree of the polymer P, that is, the upper limit of Mw (weight average molecular weight)/Mn (number average molecular weight) is, for example, 2.5 or less, preferably 2.2 or less, and more preferably 2.0 or less. Thereby, the width|variety of molecular weight distribution of polymer P can be reduced and a uniform crosslinked structure can be formed. In addition, the lower limit of Mw/Mn is good also as 1.0 or more, for example, and can be made into 1.5 or more. In addition, Mw/Mn is so good that it is close to monodispersion. In addition, Mw/Mn is a dispersion degree which shows the width|variety of molecular weight distribution. By making Mw/Mn of polymer P into the said range, the shape of the resin film containing the adhesive composition containing polymer P can be made favorable.

Here, the weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw/Mn) use, for example, a polystyrene conversion value obtained from a calibration curve of standard polystyrene (PS) obtained by GPC measurement. Measurement conditions are as follows, for example.

Gel permeation chromatography apparatus HLC-8320GPC manufactured by Tosoh Corporation

Column: TSK-GEL Supermultipore HZ-M manufactured by Tosoh Corporation

Detector: RI detector for liquid chromatograms

Measuring temperature: 40℃

Solvent: THF

Sample concentration: 2.0 mg/milliliter

The compounding quantity of the polymer P in the adhesive composition of this embodiment can be 5-80 mass % with respect to the whole adhesive composition, Preferably it is 10-70 mass %, More preferably, it is 20-60 mass %. mass%. By using the polymer P in an amount within the above range, an adhesive composition having excellent handleability and high transparency in a cured product thereof can be obtained.

(Method for Producing Polymer P)

Polymer P may be manufactured (synthesized) by any method, for example, a step of preparing a raw material polymer comprising a structural unit represented by Formula (1) and a structural unit represented by Formula (7) (Step I ) and reacting the obtained raw material polymer with a compound having the above-described reactive group in the presence of a basic catalyst to obtain a polymer P comprising a first structural unit represented by the formula (1) and a second structural unit having a reactive group It can manufacture by the method including a process (process II).

Hereinafter, as an example, the polymer P includes a structural unit represented by Formula (1) and a structural unit represented by Formula (2), and R ₅ in Formula (2) is Formula (I) or Formula (II) In this case, the manufacturing method thereof will be described in detail. The method for producing polymer P should not be construed as being limited to the specific structure described above.

<Preparation of raw material polymer>

The raw material polymer comprising the structural unit represented by the formula (1) and the structural unit represented by the formula (7) is typically a monomer represented by the formula (1-m) and maleic anhydride polymerization (addition polymerization) can be obtained by _{The definitions of R 1} , R ₂ , R ₃ and R ₄ , and n in the formula (1-m) are the same as those in the formula (1). It is the same also about a preferable aspect.

Examples of the monomer represented by the formula (1-m) include bicyclo[2.2.1]-hept-2-ene (common name: 2-norbornene), 5-methyl-2-norbornene, 5- Ethyl-2-norbornene, 5-butyl-2-norbornene, 5-hexyl-2-norbornene, 5-decyl-2-norbornene, 5-allyl-2-norbornene, 5- (2-propenyl)-2-norbornene, 5-(1-methyl-4-pentenyl)-2-norbornene, 5-ethynyl-2-norbornene, 5-benzyl-2-nor Bornene, 5-phenethyl-2-norbornene, 2-acetyl-5-norbornene, 5-norbornene-2-carboxylic acid, 5-norbornene-2-methyl carboxylate, 5 -norbornene-2,3-dicarboxylic anhydride etc. are mentioned. The monomer represented by Formula (1-m) may be used individually by 1 type, and may be used in combination of 2 or more type.

Although the method of polymerization is not limited, Radical polymerization using a radical polymerization initiator is preferable.

As a polymerization initiator, an azo compound, an organic peroxide, etc. can be used, for example.

Specifically as the azo compound, azobisisobutyronitrile (AIBN), dimethyl 2,2'-azobis(2-methylpropionate), 1,1'-azobis(cyclohexanecarbonitrile) (ABCN) and the like.

Examples of the organic peroxide include hydrogen peroxide, di-tert-butyl peroxide (DTBP), benzoyl peroxide (benzoyl peroxide, BPO), and methyl ethyl ketone peroxide (MEKP).

Only 1 type may be used for a polymerization initiator, and may be used in combination of 2 or more type.

As a polymerization solvent, organic solvents, such as diethyl ether, tetrahydrofuran, toluene, methyl ethyl ketone, can be used, for example. A single solvent may be sufficient as a polymerization solvent, and a mixed solvent may be sufficient as it.

Addition polymerization is advanced by dissolving the monomer represented by Formula (1-m), maleic anhydride, and a polymerization initiator in a solvent, injecting|throwing-in to a reaction container, and heating after that. The heating temperature is, for example, 50 to 80°C, and the heating time is, for example, 5 to 20 hours.

It is preferable that the molar ratio of the monomer represented by Formula (1-m) and maleic anhydride at the time of inject|throwing-in to a reaction container is 0.5:1 - 1:0.5. From the viewpoint of molecular structure control, the molar ratio is preferably 1:1.

By the above process, a "raw material polymer" can be obtained.

The raw material polymer may be any of a random copolymer, an alternating copolymer, a block copolymer, a periodic copolymer, and the like. Typically, it is a random copolymer or an alternating copolymer. In addition, in general, maleic anhydride is known as a monomer having strong alternating copolymerizability.

Moreover, you may perform the process of removing low molecular weight components, such as an unreacted monomer, an oligomer, and a polymerization initiator, remaining after the synthesis|combination of a raw material polymer.

Specifically, the synthesized raw material polymer and the organic layer containing the low molecular weight component are concentrated, and then mixed with an organic solvent such as tetrahydrofuran (THF) to obtain a solution. And this solution is mixed with poor solvents, such as methanol, and a monomer is precipitated. The purity of the raw material polymer can be improved by filtering out this precipitate and drying it.

<Preparation of polymer P>

By reacting the above-mentioned raw material polymer and the compound represented by formula (11) as a compound having a reactive group in the presence of a basic catalyst, at least a part of the structural unit of formula (7) contained in the raw material polymer is ring-opened, A structural unit represented by 13) and a structural unit represented by formula (14) are produced, and as a result, a polymer (p-1) having a structure represented by formula (p-1) is produced. f in formulas (11), (13) and (p-1) has the same meaning as f in formula (I), and R ₁ to R ₄ and n in formula (p-1) are represented by formula (1) ) is the same as in p, q, r and s in the formula (p-1) represent the molar content of each structural unit in the polymer (p-1), and p+q+r+s=1.

Alternatively, by reacting the above raw material polymer with the compound represented by formula (12) as a compound having a reactive group in the presence of a basic catalyst, at least a part of the structural unit of formula (7) contained in the raw material polymer is ring-opened, The structural unit represented by the formula (13), the structural unit represented by the formula (15), and the structural unit represented by the formula (14) are produced, resulting in a polymer (p) having a structure represented by the formula (p-2) -2) is generated. f in formula (12), formula (13), formula (15), and formula (p-1) has the same meaning as f in formula (I), R ₁ to R ₄ in formula (p-2) and n is synonymous with the thing in Formula (1). a, b, c, d and e in the formula (p-2) represent the molar content of each structural unit in the polymer (p-2), and a+b+c+d+e=1.

More specifically, a solution in which a raw material polymer is dissolved in an appropriate organic solvent is prepared first. As the organic solvent, a single solvent or a mixture of methyl ethyl ketone (MEK), propylene glycol monomethyl ether acetate (PGMEA), dimethyl acetamide (DMAc), N-methylpyrrolidone (NMP), tetrahydrofuran (THF), etc. Although a solvent can be used, it is not limited only to these, Various organic solvents used in the synthesis|combination of organic compounds and polymers can be used.

Next, the compound of Formula (11) or the compound of Formula (12) is added to the above solution, and a basic catalyst is further added, and the mixed solution is appropriately mixed to obtain a uniform solution. As the base catalyst, an alkylamine such as pyridine and triethylamine, an amine compound such as dimethylaniline, urotropine and dimethylaminopyridine, and a metal salt such as sodium acetate can be used.

Next, reaction is advanced by heating the obtained mixed solution at the temperature of 50-100 degreeC, for example. Thereby, the target polymer P can be obtained.

(monomer)

The monomer used in the photocurable adhesive composition of the present embodiment is a compound in which the polymer P can be dissolved, and is a compound having a reactive group capable of participating in the crosslinking reaction of the polymer P. The monomer is capable of crosslinking polymer P (capable of chemical bonding with polymer P) by the action of active species generated from the photopolymerization initiator. The monomer may not only chemically bond with the polymer P, but may also undergo a polymerization reaction between the monomers to form a polymer.

By including such a monomer, the adhesive composition of this embodiment can adjust a viscosity suitably and is excellent in handleability. Moreover, since the polymer P can be dissolved in this monomer, a uniform resin film is obtained by hardening process, and the resin film which has high transparency in which the insoluble component of polymer P does not exist is obtained.

Although it will not restrict|limit especially as a monomer used for the adhesive composition of this embodiment, if it is a compound in which polymer P can melt|dissolve, For example, a polar (meth)acrylic compound is mentioned. As a specific example of a polar acrylic compound, For example, dimethyl (meth)acrylamide, diethyl (meth)acrylamide, (meth)acryloylmorpholine, tetrahydrofurfuryl (meth)acrylate, phenoxyethyl (meth) Acrylate, hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, hydroxypropyl (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, (2-methyl -2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, (3-ethyloxetan-3- Yl) methyl (meth) methacrylate, cyclic trimethylol propane formal (meth) acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, nonylphenoxy polyethylene glycol (meth) acrylate, phenoxy Polyethylene glycol (meth) acrylate, methoxyethoxyethyl (meth) acrylate, N-vinyl pyrrolidone, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, triethylene glycol di (meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra( Although meth)acrylate etc. are mentioned, It is not limited to these. These monomers may be used individually by 1 type, and may be used in combination of 2 or more type.

It is preferable that the adhesive composition of this embodiment does not contain a non-reactive solvent. By not containing a non-reactive solvent, since volatilization of a solvent does not arise at the time of hardening process, it can be used suitably as an adhesive agent. Here, the non-reactive solvent means a solvent that can be volatilized by heat treatment, which does not have a polymerizable or crosslinkable reactive group. Not containing a non-reactive solvent means not containing substantially, and points out the case where content of the non-reactive solvent with respect to the whole adhesive composition is 0.1 mass % or less.

The quantity of the monomer in the adhesive composition of this embodiment can be 10-60 mass % with respect to the whole adhesive composition, Preferably it is 20-50 mass %, More preferably, it is 25-45 mass %. Further, the monomer is, for example, 10 to 2000 mass%, preferably 12 to 1900 mass%, more preferably 15 to 1500 mass%, still more preferably 15 to 1000 mass%, with respect to the mass of the polymer P, further More preferably, it is 20-400 mass %, Especially preferably, it is preferable that it is an amount of 20-150 mass %. By using a monomer within the said range, while being excellent in applicability|paintability, the adhesive composition excellent in sclerosis|hardenability can be obtained.

(radical photopolymerization initiator)

The adhesive composition of this embodiment may also contain a radical photopolymerization initiator. By mix|blending a radical photopolymerization initiator, the adhesive composition of this embodiment can be hardened by light irradiation.

As the radical photopolymerization initiator, a compound known in the art can be used, for example, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one , 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one, 2-methyl-1-(4-methyl Thiophenyl)-2-morpholinopropan1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[( alkylphenone compounds such as 4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone; benzophenone compounds such as benzophenone, 4,4'-bis(dimethylamino)benzophenone, and 2-carboxybenzophenone; benzoin compounds such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; Thioxanthone type, such as thioxanthone, 2-ethyl thioxanthone, 2-isopropyl thioxanthone, 2-chloro thioxanthone, 2, 4- dimethyl thioxanthone, 2, 4- diethyl thioxanthone compound; 2-(4-Methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-s- Triazine, 2-(4-ethoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-ethoxycarbonylnaphthyl)-4,6-bis(trichloro halomethylated triazine-based compounds such as romethyl)-s-triazine; 2-trichloromethyl-5-(2'-benzofuryl)-1,3,4-oxadiazole, 2-trichloromethyl-5-[β-(2'-benzofuryl)vinyl]-1,3 Halomethylated oxadiazole compounds such as ,4-oxadiazole, 4-oxadiazole and 2-trichloromethyl-5-furyl-1,3,4-oxadiazole; 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)- 4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'- biimidazole compounds such as tetraphenyl-1,2'-biimidazole; 1,2-Octanedione,1-[4-(phenylthio)-2-(O-benzoyloxime)], ethanone,1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole oxime ester compounds such as -3-yl]-,1-(O-acetyloxime); titanocene compounds such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium; benzoic acid ester compounds such as p-dimethylaminobenzoic acid and p-diethylaminobenzoic acid; Acridine-type compounds, such as 9-phenyl acridine, etc. are mentioned. A radical photopolymerization initiator may be used individually by 1 type, and may be used in combination of 2 or more type.

The compounding quantity of a radical photopolymerization initiator is, for example, 1-60 mass parts with respect to 100 mass parts of polymer P, Preferably it is 1-50 mass parts, More preferably, it is 1-40 mass parts, More preferably, It is 1-30 mass parts, More preferably, it is 2-15 mass parts, Especially preferably, it is 2-8 mass parts.

(Other ingredients)

The photocurable adhesive composition of this embodiment is a filler, binder resins other than the above-mentioned polymer, acid generator, heat resistance improver, plasticizer, polymerization inhibitor, ultraviolet absorber, antioxidant, matting agent, antifoamer according to various objects and required characteristics according to various purposes and required characteristics. , a leveling agent, a surfactant, an antistatic agent, a dispersing agent, a slip agent, a surface modifier, a thixotropic agent, a thixotropic auxiliary agent, a silane coupling agent, and a polyhydric phenol compound.

(purpose)

The adhesive composition of this embodiment can be used for manufacture of an optical component, and can be used as an adhesive agent for optical components. The adhesive composition of this embodiment can be specifically used as an adhesive agent for optical lenses, such as a vehicle-mounted lens, an adhesive agent for optical pickup, an adhesive agent for optical path bonding, and a photocurable adhesive agent for optical bonding.

The adhesive composition of this embodiment is arrange|positioned between an optical component and a to-be-adhered body, and can make an optical component adhere|attach to a to-be-adhered body by irradiating light from the optical component and/or to-be-adhered body side, and hardening it, for example. The cured adhesive composition exists as an adhesive layer between the optical component and the adherend.

As mentioned above, although embodiment of this invention was described, these are illustrations of this invention, and you may employ|adopt various structures other than the above.

<Example>

Hereinafter, although an Example and a comparative example demonstrate this invention, this invention is not limited to these.

First, each material used in the Example was prepared by the method shown below.

(Synthesis Example 1 (Synthesis of Polymer A))

In an appropriately sized reaction vessel equipped with a stirrer and cooling tube, maleic anhydride (735 g, 7.5 mol), 2-norbornene (706 g, 7.5 mol) and dimethyl2,2'-azobis(2-methylpropio) nate) (69 g, 0.3 mol) was weighed and dissolved in methyl ethyl ketone and toluene. After removing dissolved oxygen in the system by nitrogen bubbling, this solution was heat-treated at 60°C for 15 hours while stirring. Thereby, the copolymer of 2-norbornene and maleic anhydride was obtained. Then, after reprecipitating the said solution cooled to room temperature using a large amount of methanol, the precipitate was filtered out, it dried with a vacuum dryer, and 1100 g of white solid was obtained.

Thus, the weight average molecular weight (Mw) of the obtained polymer was 10,000, and the dispersion degree (Mw/Mn) was 2.1.

In an appropriately sized reaction vessel equipped with a stirrer and a cooling tube, the above-mentioned copolymer of 2-norbornene and maleic anhydride (250 g) was weighed and dissolved in MEK (460 g). Furthermore, 2-hydroxyethyl acrylate (HEA, 188.8 g, 1.626 mol) and sodium acetate (25 g) were added, followed by heating at 70°C for 6 hours. After acid treatment by adding formic acid to the reaction solution, it was added dropwise to a large amount of pure water to precipitate a polymer. The filtered solid was dried with a vacuum dryer at 40 degreeC for 16 hours, and the polymer A was obtained. The yield was 327.5 g, Mw was 10,100, and Mw/Mn was 2.30.

In Synthesis Example 1, a polymer A having each structural unit represented by the formula (PA) was obtained.

(Synthesis Example 2 (Synthesis of Polymer B))

In an appropriately sized reaction vessel equipped with a stirrer and cooling tube, maleic anhydride (735 g, 7.5 mol), 2-norbornene (706 g, 7.5 mol) and dimethyl2,2'-azobis(2-methylpropio) nate) (69 g, 0.3 mol) was weighed and dissolved in methyl ethyl ketone and toluene. After removing dissolved oxygen in the system by nitrogen bubbling, this solution was heat-treated at 80°C for 15 hours while stirring. Thereby, the copolymer of 2-norbornene and maleic anhydride was obtained. Then, it cooled to room temperature. After reprecipitating the said solution using a large amount of methanol, the precipitate was filtered out, it dried with a vacuum dryer, and 1100 g of white solid was obtained.

Thus, the weight average molecular weight (Mw) of the obtained polymer was 7,000, and the dispersion degree (Mw/Mn) was 1.8.

In a reaction vessel of an appropriate size equipped with a stirrer and a cooling tube, the above-mentioned copolymer of 2-norbornene and maleic anhydride (150 g) was weighed and dissolved in MEK (280 g). Furthermore, 2-hydroxyethyl acrylate (HEA, 113.3 g, 0.976 mol) and sodium acetate (15 g) were added, followed by heating at 70°C for 6 hours. After acid treatment by adding formic acid to the reaction solution, it was added dropwise to a large amount of pure water to precipitate a polymer. The filtered solid was dried with a vacuum dryer at 40 degreeC for 16 hours, and the polymer B was obtained. The yield was 193.5 g, Mw was 7,300, and Mw/Mn was 2.02.

In Synthesis Example 2, a polymer B having each structural unit represented by the formula (PB) was obtained.

(Synthesis Example 3 (Synthesis of Polymer C))

In an appropriately sized reaction vessel equipped with a stirrer and a cooling tube, maleic anhydride (460 g, 4.69 mol) and 2-norbornene (441.6 g, 4.69 mol) were weighed and dissolved in methyl ethyl ketone and toluene. With respect to this solution, dissolved oxygen in the system was removed by nitrogen bubbling, and after reaching 80°C while stirring, dimethyl 2,2'-azobis(2-methylpropionate) (43.2 g, 0.19 mol) and A solution of n-dodecyl mercaptan (152.1 g, 0.75 mol) in methyl ethyl ketone was sequentially added over 1 hour, and then heat treatment was performed for an additional 7 hours. Thereby, the copolymer of 2-norbornene and maleic anhydride was obtained. Then, it cooled to room temperature. After reprecipitating the said solution using a large amount of methanol, the precipitate was filtered out and dried with a vacuum dryer, and 832 g of white solid was obtained.

Thus, the weight average molecular weight (Mw) of the obtained polymer was 2,600, and the dispersion degree (Mw/Mn) was 1.53.

In a reaction vessel of an appropriate size equipped with a stirrer and a cooling tube, the above-mentioned copolymer of 2-norbornene and maleic anhydride (100 g) was weighed and dissolved in MEK (190 g). Furthermore, 2-hydroxyethyl acrylate (HEA, 75.5 g, 0.65 mol) and sodium acetate (10 g) were added, followed by heating at 70°C for 6 hours. To this reaction solution, glycidyl methacrylate (GMA, 74 g, 0.52 mol) was added, followed by stirring at 70°C for 6 hours. After acid treatment by adding formic acid to the reaction solution, it was added dropwise to a large amount of pure water to precipitate a polymer. The filtered solid was dried with a vacuum dryer at 40 degreeC for 16 hours, and the polymer C was obtained. The yield was 207.5 g, Mw was 4,900, and Mw/Mn was 1.79.

In Synthesis Example 3, a polymer C having each structural unit represented by the formula (PC) was obtained.

(Synthesis Example 4 (Synthesis of Polymer D))

Methyl ethyl ketone (192 g) is weighed into a reaction vessel of an appropriate size equipped with a stirrer and a cooling tube, and dissolved oxygen in the system is removed from the solution by nitrogen bubbling, and then after reaching 80° C. while stirring, methacrylic Methyl acid (120.2 g, 1.20 mol), glycidyl methacrylate (170.6 g, 1.20 mol), dimethyl 2,2'-azobis (2-methylpropionate) (3.05 g, 0.013 mol) and n- A methyl ethyl ketone solution of dodecyl mercaptan (15.1 g, 0.074 mol) was sequentially added over 3 hours, and then methyl of dimethyl 2,2'-azobis (2-methylpropionate) (0.76 g, 3.24 mmol) was added. An ethyl ketone solution was added, and heat treatment was further performed for 4 hours. Thereby, the copolymer of methyl methacrylate and glycidyl methacrylate was obtained. Then, it cooled to room temperature. After reprecipitating the said solution using a large amount of methanol, the precipitate was filtered out, and it dried with a vacuum dryer to obtain 207.8 g of white solid.

Thus, the weight average molecular weight (Mw) of the obtained polymer was 14,300, and the dispersion degree (Mw/Mn) was 1.83.

In a reaction vessel of an appropriate size equipped with a stirrer and a cooling tube, the above-mentioned copolymer of methyl methacrylate and glycidyl methacrylate (100 g) was weighed and dissolved in MEK (200 g). Further, acrylic acid (59.5 g, 0.83 mol) and sodium acetate (15 g) were added, followed by heating at 70°C for 6 hours. After cooling the reaction solution, it was added dropwise to a large amount of pure water to precipitate a polymer. The filtered solid was dried with a vacuum dryer at 40 degreeC for 16 hours, and polymer E was obtained. The yield was 95.4 g, Mw was 9,600, and Mw/Mn was 1.60.

In Synthesis Example 4, a polymer D having each structural unit represented by the formula (PD) was obtained.

(Synthesis Example 5 (Synthesis of Polymer E))

A copolymer of styrene/maleic anhydride SMA-1000-P (manufactured by Cray Valley USA, LLC) was prepared.

SMA-1000-P (157.4 g) described above was weighed into a reaction vessel of an appropriate size equipped with a stirrer and a cooling tube, and dissolved in methyl ethyl ketone (270 g). Furthermore, 2-hydroxyethyl acrylate (HEA, 113.3 g, 0.976 mol) and sodium acetate (15 g) were added, followed by heating at 70°C for 6 hours. After acid treatment by adding formic acid to the reaction solution, it was added dropwise to a large amount of pure water to precipitate a polymer. The filtered solid was dried with a vacuum dryer at 40 degreeC for 16 hours, and polymer E was obtained. The yield was 189.1 g, Mw was 5,400, and Mw/Mn was 2.21.

In Synthesis Example 5, a polymer E having each structural unit represented by the formula (PE) was obtained.

(Preparation of photocurable adhesive composition)

According to Table 1 below, a polymer was dissolved in a monomer to obtain a mixed solution. Then, this mixed solution was filtered with a 0.2 micrometer nylon filter, and the adhesive composition was obtained.

The detail of each component in Table 1 is as follows.

(Polymer)

ㆍPolymer A: Polymer A prepared in Synthesis Example 1

ㆍPolymer B: Polymer B prepared in Synthesis Example 2

ㆍPolymer C: Polymer C prepared in Synthesis Example 3

ㆍPolymer D: Polymer D prepared in Synthesis Example 4

ㆍPolymer E: Polymer E prepared in Synthesis Example 5

(monomer)

ㆍTHFA: tetrahydrofurfuryl acrylate

ㆍINAA: isononyl acrylate

ㆍIBXA: isobornyl acrylate

ㆍDPHA: dipentaerythritol hexaacrylate

ㆍTMPTA: trimethylolpropane triacrylate

(Polymerization Initiator)

ㆍIrgacure184 (manufactured by BASF, photo-radical polymerization initiator)

(Evaluation of photo-curable adhesive composition)

About the obtained adhesive composition, the following items were evaluated. An evaluation result is shown in Table 1.

(solubility)

In the step of preparing the adhesive composition described above, a polymer was dissolved in a monomer to obtain a mixed solution, and when the mixed solution was filtered through a 0.2 μm nylon filter, it was visually observed whether the polymer remained in the nylon filter. What did not remain polymer was evaluated as "dissolution", and what remained was evaluated as "insoluble".

(Evaluation of cured product of photocurable adhesive composition)

About the obtained adhesive composition, application|coating and photocuring were performed on the following conditions, and the cured film was obtained. About the obtained cured film, the following items were evaluated. An evaluation result is shown in Table 1.

(Light curing -Production of plate-shaped cured product-)

A curable resin composition was introduced between two glass plates whose gap was controlled to 1 mm using a spacer with a thickness of 1 mm, and a conveyor-type UV irradiator equipped with a high-pressure mercury lamp (manufactured by Takeden Co., Ltd.: MDC15001Y) was used. , illuminance: 100 mW/cm 2 , accumulated light amount: 500 mJ/cm 2 UV irradiation was performed by conveying the conveyor. After UV irradiation was irradiated from one side of the glass plate, the taken out sample was turned over and passed through a conveyor again, and UV irradiation was performed from both sides (accumulated light amount: 1000 mJ/cm 2 ), and a cured product was obtained.

(Cured material appearance)

The obtained plate of the cured product having a thickness of 1 mm was visually observed. The case of colorless and transparent was evaluated as "colorless and transparent", the case of colorless and transparent was evaluated as "colored transparent", and the case of opaque was evaluated as "opaque".

(contractility)

The liquid specific gravity of the composition before curing was measured using a pycnometer, and the curable resin composition was further cured by light irradiation, and then the cured product having a thickness of 1 mm was measured with an electronic hydrometer (ALFA MIRAGE Co., Ltd.: SD-200L). ) was used, and the specific gravity of the cured product was obtained. The cure shrinkage rate was computed from the ratio of liquid specific gravity and hardened|cured material specific gravity. A smaller cure shrinkage rate is preferable for use as an adhesive.

Curing shrinkage = [(Cured material specific gravity - Liquid specific gravity)/Cured material specific gravity] x 100 (%)

(tensile stress, tensile modulus, strain)

A sheet of a cured product having a thickness of 1 mm was punched out in the shape of a JIS 3 dumbbell, and a tensile test was performed according to JISK6251 to evaluate tensile stress, tensile modulus of elasticity, and strain at break. The tensile modulus was read the maximum slope at the time of the test. Incidentally, the unit of tensile strength and tensile modulus is MPa. The unit of rupture strain is %. Larger values of tensile stress and tensile modulus indicate higher tensile strength.

(Adhesive)

A photocurable resin composition was applied to an adherend [25 mm x 80 mm x thickness 2 mm, an acrylic plate (manufactured by Acrysunday Co., Ltd.: Acrysunday plate 001, transparent, thickness 2 mm)], and the adherend [acrylic plate] was joined to an area of 25 mm x 10 mm, pressed with a bulldog clip, and then UV irradiated (irradiation conditions: high-pressure mercury lamp, illuminance: 100 mW/cm 2 , accumulated light amount: 500 mJ/cm 2 ). The bulldog clip was removed from the test piece carried out by the conveyor, and by turning the front and back sides and passing the conveyor again, UV irradiation was performed from the back surface (accumulated light amount: 1000 mJ/cm 2 ), and a test piece for adhesion test was obtained.

The obtained test piece for an adhesion test was measured for adhesive strength at a test rate of 0.5 mm/min in accordance with the JISK6850 tensile shear adhesion strength test method of a rigid adherend. It shows that adhesive force is so high that the value of shear adhesive force is high.

The hardened|cured material of the adhesive composition of an Example was transparent and was equipped with high adhesiveness.

This application claims priority on the basis of Japanese Patent Application No. 2020-023730 for which it applied on February 14, 2020, and takes in all the indications here.

Claims (9)

A polymer comprising a first structural unit represented by the formula (1) and a second structural unit having a reactive group;
comprising a monomer;
the polymer is dissolved in the monomer,
The monomer comprises a polar (meth)acrylic compound,
Light curable adhesive composition:

In formula (1),
R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and n is 0, 1 or 2. The photocurable adhesive composition of Claim 1 whose said polymer is 5 mass % or more and 80 mass % or less with respect to the said whole photocurable adhesive composition. The photo-curable adhesive composition according to claim 1, wherein the reactive group is at least one selected from a vinyl group, a vinylidene group, an acryloyl group, a methacryloyl group, an epoxy group, a carboxyl group, and a hydroxyl group. The photocurable adhesive composition according to claim 1, wherein the second structural unit has a structure represented by formula (2):

In formula (2),
R ₅ is an organic group having 1 to 30 carbon atoms and having at least one reactive group selected from a vinyl group, a vinylidene group, an acryloyl group, a methacryloyl group, an epoxy group, a carboxyl group and a hydroxyl group. The photocurable adhesive composition according to claim 1, wherein the polymer has a weight average molecular weight of 1000 or more and 30000 or less. The photo-curable adhesive composition according to claim 1, further comprising a photo-radical polymerization initiator. The light curable adhesive composition of claim 1 , wherein the composition is substantially free of non-reactive solvents. The film containing the hardened|cured material of the photocurable adhesive composition in any one of Claims 1-7. An optical component comprising the film according to claim 8 as an adhesive layer.