WO2014162942A1

WO2014162942A1 - Resin film and method for producing same

Info

Publication number: WO2014162942A1
Application number: PCT/JP2014/058475
Authority: WO
Inventors: 伊藤大祐; 菊地慎二; 田靡文大
Original assignee: 株式会社ダイセル
Priority date: 2013-04-05
Filing date: 2014-03-26
Publication date: 2014-10-09
Also published as: TW201446844A; JP6006155B2; JP2014201663A

Abstract

This resin film is obtained by curing an active energy ray-curable composition, wherein the active energy ray-curable composition is characterized by containing 10 wt% or more, relative to all curable compounds, of a tetra- to dodecafunctional urethane (meth)acrylate (A) having in the molecule a group containing a tricyclodecane skeleton represented by formula (1). The thickness of the resin film preferably exceeds 25 μm, and is ideally 500 μm or greater.

Description

Resin film and method for producing the same

The present invention relates to a resin film useful as an optical substrate such as a liquid crystal display, an organic EL display, a touch panel, a display substrate such as a color filter, an optical member, and the like, and a method for producing the same. This application claims the priority of Japanese Patent Application No. 2013-079128 for which it applied to Japan on April 5, 2013, and uses the content here.

Conventionally, a glass substrate has been used as a display substrate for a liquid crystal display or the like, but in recent years, a display using a plastic substrate has been proposed from the viewpoint of lightness, thinning, resistance to cracking, mass productivity, manufacturing cost, and the like. It attracts attention.

As an optical plastic substrate, a hard coat film in which a hard coat layer is coated on a plastic substrate such as a polyethylene terephthalate film (PET film) is known. However, such a hard coat film not only has low pencil hardness, but when it is thickened, the hard coat layer curls or cracks in the hard coat layer due to curing shrinkage of the resin constituting the hard coat layer. There was a problem such as entering.

On the other hand, a plastic member made of a cured product obtained by curing a polymerizable composition has been proposed as an optical plastic member. For example, Japanese Patent Application Laid-Open No. 2002-302517 discloses a resin molded article having excellent heat resistance and low birefringence when a polymerizable composition containing 75 wt% or more of a tri- to 8-functional aliphatic polyfunctional methacrylate is cured. It is described that JP-A-2003-292545 discloses a resin molded article having excellent heat resistance and a small linear expansion coefficient when a polymerizable composition containing an aliphatic difunctional methacrylate and a trifunctional or higher aliphatic polyfunctional methacrylate is cured. It is described that it is obtained.

Japanese Patent No. 4690053 discloses (A) a polyfunctional urethane (meth) acrylate having an alicyclic structure obtained by reacting a polyisocyanate compound having an alicyclic structure with a hydroxyl group-containing (meth) acrylate, and (B When a (meth) acrylate photopolymerizable composition containing a bifunctional (meth) acrylate having an alicyclic structure is photocured, a resin molded product having a thickness of 50 to 400 μm and a pencil hardness of 4H or more is obtained. It is described.

However, the conventional resin molded body tends to cause cracks and curls due to curing shrinkage of the resin, and it is difficult to increase the film thickness. Therefore, a resin film having a high surface hardness such as a pencil hardness of about 9H has not been obtained.

JP 2002-302517 A JP 2003-292545 A Japanese Patent No. 4690053

An object of the present invention is to provide a resin film free from cracks and curls due to cure shrinkage of the resin and having a high surface hardness, and a method for producing the same.
Another object of the present invention is to provide a resin film having a high surface hardness without cracks even if it is a thick film of 500 μm or more, and a method for producing the same.

As a result of diligent studies to solve the above-mentioned object, the present inventors have found that when a curable composition containing a specific amount of a 4- to 12-functional urethane (meth) acrylate having a tricyclodecane skeleton is cured, curing shrinkage occurs. The inventors have found that the generation of cracks and curls is remarkably suppressed, the film thickness can be increased, and a resin film having a very high surface hardness can be obtained, and the present invention has been completed.

That is, this invention is a resin film obtained by hardening | curing an active energy ray curable composition, Comprising: The said active energy ray curable composition is following formula (1).

A resin film comprising 10 to 10% by weight or more of a 4- to 12-functional urethane (meth) acrylate (A) having a tricyclodecane skeleton group represented by provide.

In the above resin film, the thickness preferably exceeds 25 μm, and more preferably 500 μm or more.

The active energy ray-curable composition includes a 4- to 12-functional urethane (meth) acrylate (A) having a group containing a tricyclodecane skeleton represented by the formula (1) in the molecule, and other curing agents. A polyfunctional (meth) acrylate may be included as the functional compound (B).

In addition, the active energy ray-curable composition includes a 4- to 12-functional urethane (meth) acrylate (A) having a group containing a tricyclodecane skeleton represented by the formula (1) in the molecule, and the like. As the curable compound (B), a polyfunctional (meth) acrylate having 4 or more functional groups may be contained.

The total amount of polyfunctional (meth) acrylates having 4 or more functional groups including 4- to 12-functional urethane (meth) acrylate (A) having a group containing a tricyclodecane skeleton represented by the formula (1) in the molecule, It is preferable that it is 30 weight% or more with respect to the whole curable compound in an active energy ray curable composition.

This invention is a manufacturing method of the said resin film, Comprising: following formula (1)

From an active energy ray-curable composition containing 10 to 10% by weight or more of a 4- to 12-functional urethane (meth) acrylate (A) having a group containing a tricyclodecane skeleton represented by A method for producing a resin film is provided, wherein the thin film layer is irradiated with active energy rays to be cured.

The resin film of the present invention is a resin film obtained by curing an active energy ray-curable composition containing a specific amount or more of a 4- to 12-functional urethane (meth) acrylate having a tricyclodecane skeleton. The occurrence of cracks and curls is remarkably suppressed, the film can be made thick, and the surface hardness can be very high. For example, when the film thickness is 100 μm or more, the pencil hardness is 4H or more, and when the film thickness is 500 μm or more, the pencil hardness is 9H or more. Further, the resin film of the present invention can obtain the high surface hardness as described above without adding a filler such as fine particle silica. Furthermore, the resin film of the present invention is excellent in optical properties such as transparency, thermal properties, and mechanical properties.

The resin film of the present invention has a 4- to 12-functional group having in its molecule a group containing a tricyclodecane skeleton represented by the above formula (1) (a group obtained by removing two hydrogen atoms of a hydroxyl group from tricyclodecane dimethanol). Urethane (meth) acrylate (A) [hereinafter sometimes simply referred to as “4- to 12-functional urethane (meth) acrylate (A)” or “urethane (meth) acrylate (A)”) It is the resin film obtained by hardening | curing the active energy ray curable composition containing 10 weight% or more with respect to this.

[Urethane (meth) acrylate (A)]
In the present invention, by setting the proportion of urethane (meth) acrylate (A) in the entire curable compound to 10% by weight or more, generation of cracks and curls due to curing shrinkage can be remarkably suppressed, and a thick film can be formed. A resin film having a high surface hardness can be obtained. When the amount of urethane (meth) acrylate (A) is less than 10% by weight of the entire curable compound, the effect of suppressing cracks and curls due to the curing shrinkage is reduced. The amount of urethane (meth) acrylate (A) is preferably 15% by weight or more, more preferably 20% by weight or more, based on the entire curable compound in the active energy ray-curable composition. Urethane (meth) acrylate (A) may be used individually by 1 type, and may be used in combination of 2 or more type.

In this specification, the number of functional groups of urethane (meth) acrylate means the number of (meth) acryloyl groups in one molecule. When the number of functional groups of the urethane (meth) acrylate (A) is 3 or less, the surface hardness of the resin film tends to decrease. On the other hand, when the number of functional groups of urethane (meth) acrylate (A) is 13 or more, the effect of suppressing the occurrence of cracks and curls due to curing shrinkage is reduced, and the impact resistance and accelerated weather resistance of the resin film are lowered. It becomes a trend. In the present invention, the number of functional groups of the urethane (meth) acrylate (A) is preferably 6 to 10, and more preferably 6 to 8.

Urethane (meth) acrylate (A) is, for example, tricyclodecane dimethanol (X) [a compound in which hydrogen atoms are bonded to both ends of a group containing a tricyclodecane skeleton represented by the above formula (1)] and poly It can be produced by reacting isocyanate (Y) with hydroxy group-containing (meth) acrylate (Z). Hereinafter, urethane (meth) acrylate (A) is simply “(A)” or “A”, tricyclodecane dimethanol (X) is simply “(X)” or “X”, and polyisocyanate (Y) is The “(Y)” or “Y” may be simply referred to, and the hydroxy group-containing (meth) acrylate (Z) may be simply referred to as “(Z)” or “Z”. In this specification, the number of functional groups of polyisocyanate means the number of isocyanate groups in one molecule, and the number of functional groups of hydroxy group-containing (meth) acrylate means the number of (meth) acryloyl groups in one molecule. Means.

For example, diisocyanate (bifunctional polyisocyanate) is used as polyisocyanate (Y), bifunctional (meth) acrylate compound is used as hydroxy group-containing (meth) acrylate (Z), tricyclodecane dimethanol (X) and When the molar ratio of polyisocyanate (Y) and hydroxy group-containing (meth) acrylate (Z) is reacted at 1: 2: 2, tetrafunctional urethane (meth) acrylate (A) can be obtained. Moreover, in the above, when a trifunctional (meth) acrylate compound is used as the hydroxy group-containing (meth) acrylate (Z), a hexafunctional urethane (meth) acrylate (A) can be obtained. Furthermore, in the above, when a tetrafunctional (meth) acrylate compound is used as the hydroxy group-containing (meth) acrylate (Z), an octafunctional urethane (meth) acrylate (A) can be obtained.

Also, triisocyanate (trifunctional polyisocyanate such as nurate polyisocyanate) is used as polyisocyanate (Y), and monofunctional (meth) acrylate compound is used as hydroxy group-containing (meth) acrylate (Z). When the molar ratio of decanedimethanol (X), polyisocyanate (Y), and hydroxy group-containing (meth) acrylate (Z) is 1: 2: 4, a tetrafunctional urethane (meth) acrylate (A ) Can be obtained. Moreover, in the above, when a bifunctional (meth) acrylate compound is used as the hydroxy group-containing (meth) acrylate (Z), an octafunctional urethane (meth) acrylate (A) can be obtained. In the above, when a trifunctional (meth) acrylate compound is used as the hydroxy group-containing (meth) acrylate (Z), a 12-functional urethane (meth) acrylate (A) can be obtained.

In the present invention, the urethane (meth) acrylate (A) can be schematically represented by (Z) _m —Y—XY— (Z) _m (m is an integer of 1 or more, preferably 1 or 2). “-” In the above formula indicates that the components on both sides are reacted (hereinafter the same).

Although it does not specifically limit as a manufacturing method of urethane (meth) acrylate (A), For example, the following method is mentioned.
[Method 1]: A method in which (X), (Y), and (Z) are mixed and reacted.
[Method 2]: A method in which (X) and (Y) are reacted to form a urethane isocyanate prepolymer containing an isocyanate group, and then the prepolymer and (Z) are reacted.
[Method 3]: A method of reacting (Y) and (Z) to form a urethane isocyanate prepolymer containing an isocyanate group, and then reacting the prepolymer with (X).

[Method 2] is preferable among [Method 1] to [Method 3].

On the other hand, when produced by [Method 1], urethane (meth) acrylate (A) increases the amount of urethane isocyanate prepolymer produced by repeating tricyclodecane dimethanol (X) and polyisocyanate (Y), ) Intramolecular density of the acryloyl group may decrease, and the surface hardness of the target resin film may decrease. Moreover, since various complicated compounds are irregularly generated, quality control may be difficult when the product is used as an active energy ray-curable resin composition.

Further, when the reaction is carried out by [Method 3], a compound in which all isocyanate groups of the polyisocyanate (Y) have reacted with the hydroxy group-containing (meth) acrylate (Z) is by-produced. Since this by-product does not contain a skeleton derived from tricyclodecane dimethanol (X), the resin film may be curled or cracked, or the surface hardness may be reduced.

In [Method 2], the following method may be mentioned as a method for synthesizing the urethane isocyanate prepolymer.
[Method 2-1]: A method in which (X) and (Y) are mixed and reacted.
[Method 2-2]: A method in which (Y) is dropped into (X) for reaction.
[Method 2-3]: A method in which (X) is dropped into (Y) for reaction.

In the case of [Method 2-2], polyisocyanate (Y) is dropped into a large amount of tricyclodecane dimethanol (X). When urethanized with the hydroxyl group of methanol (X) and written schematically, a urethane isocyanate prepolymer having hydroxyl groups at both ends of the XYX type is formed, and this is further reacted with 2 moles of polyisocyanate (Y). However, when written schematically, a compound having an isocyanate group at both ends of the YXYXY type is generated, and the same reaction is repeated. Generate in large quantities.
Y- [XY] _n -XY (n is an integer of 1 or more)

When such a product is produced in a large amount, urethane (meth) acrylate [(Z) _m -Y- [XY] _n -X obtained by reacting this with a hydroxy group-containing (meth) acrylate (Z). -Y- (Z) _m (m, n is an integer of 1 or more)], the intramolecular density of the (meth) acryloyl group is low, and a sufficient crosslinking density cannot be obtained even when cured. There exists a possibility that the surface hardness of a certain resin film may fall. Therefore, [Method 2-1] and [Method 2-3] are preferably used to increase the surface hardness of the resin film.

In [Method 2-1], tricyclodecane dimethanol (X) and polyisocyanate (Y) and, if necessary, a diluting solvent are charged into a reactor, and the temperature is raised as necessary while stirring until uniform. Thereafter, a method of introducing a urethanization catalyst and starting urethanization is preferred. The temperature may be increased as necessary after the urethanization catalyst is added.

When the urethanization catalyst is added from the beginning, the urethanization reaction proceeds in a non-uniform state of tricyclodecane dimethanol (X) and polyisocyanate (Y) at the stage of charging the polyisocyanate (Y). The molecular weight and viscosity of the resulting urethane isocyanate prepolymer change, and the reaction may be terminated in a state where unreacted polyisocyanate (Y) remains in the system. In such a case, a by-product is generated due to the reaction of the hydroxy group-containing (meth) acrylate (Z) and the remaining polyisocyanate (Y) to be used later, which may cause a decrease in the surface hardness of the resin film. is there. The content of such a by-product is preferably less than 15% by weight based on the urethane (meth) acrylate (A) having a skeleton derived from the target tricyclodecane dimethanol (X). There exists a possibility that the surface hardness of a resin film may fall that it is 15 weight% or more. [Method 2-1] is industrially superior in that urethane (meth) acrylate (A) can be produced in one pot.

In [Method 2-3], for example, a polyisocyanate (Y), a urethanization catalyst, and, if necessary, a diluting solvent are charged into a reactor and stirred until uniform. While stirring, the temperature is raised as necessary, and tricyclodecane dimethanol (X) is added dropwise.

[Method 2-3] is preferable in that the following products described in [Method 2-2] are the least generated.
Y- [XY] _n -XY (n is an integer of 1 or more)

In any method, when the urethane isocyanate prepolymer is synthesized by reaction of tricyclodecane dimethanol (X) and polyisocyanate (Y), tricyclodecane dimethanol (X) and polyisocyanate (Y) are combined. The reaction is preferably carried out until the isocyanate group concentration in the reaction solution is equal to or lower than the end-point isocyanate group concentration. The isocyanate group concentration in the reaction solution may be referred to as “NCO group concentration”.

“End-point isocyanate group concentration” means the theoretical isocyanate group concentration (hereinafter, sometimes referred to as “theoretical end-point isocyanate group concentration”) assuming that all of the hydroxyl groups charged into the system have been urethanized. It means the higher isocyanate group concentration of the isocyanate group concentration when the isocyanate group concentration no longer changes.

When the generated urethane isocyanate prepolymer and the hydroxy group-containing (meth) acrylate (Z) are reacted, if the amount of isocyanate group used for the reaction exceeds the amount of hydroxyl groups, there is a possibility that unreacted isocyanate groups will remain and cause gelation. There is. Moreover, it becomes a cause of the hardening defect of a coating film after mix | blending. For this reason, it is preferable to adjust the addition amount of hydroxy-group containing (meth) acrylate (Z) so that the amount of hydroxyl groups used for reaction may become larger than the amount of isocyanate groups.

This reaction is preferably performed in the presence of a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, or phenothiazine for the purpose of preventing polymerization. The addition amount of these polymerization inhibitors is preferably 1 to 10,000 ppm (weight basis), more preferably 100 to 1000 ppm, and still more preferably 400 to 500 ppm with respect to the urethane (meth) acrylate (A) to be produced. If the addition amount of the polymerization inhibitor is less than 1 ppm relative to the urethane (meth) acrylate (A), a sufficient polymerization inhibition effect may not be obtained. If it exceeds 10000 ppm, the physical properties of the product may be adversely affected. There is.

For the same purpose, this reaction is preferably performed in a molecular oxygen-containing gas atmosphere. The oxygen concentration is appropriately selected in consideration of safety.

In the production of urethane (meth) acrylate (A), the reaction (urethanization reaction) may be performed using a catalyst (urethanization catalyst) in order to obtain a sufficient reaction rate. As the catalyst, dibutyltin dilaurate, tin octylate, tin chloride or the like can be used, but dibutyltin dilaurate is preferable from the viewpoint of reaction rate. The amount of these catalysts added is usually 1 to 3000 ppm (weight basis), preferably 50 to 1000 ppm. When the addition amount of the catalyst is less than 1 ppm, a sufficient reaction rate may not be obtained. When the addition amount is more than 3000 ppm, the physical properties of the target product may be adversely affected, such as a decrease in the surface hardness of the resin film.

The reaction can be performed in the presence of a known volatile organic solvent. Examples of the volatile organic solvent include, but are not limited to, esters such as ethyl acetate, butyl acetate, and isobutyl acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone; ethylene glycol monomethyl ether and the like Ethers; glycol monoether acetates such as diethylene glycol monobutyl ether acetate and propylene glycol monomethyl ether acetate; hydrocarbons such as xylene and toluene; and mixtures thereof. Among these, ketones such as methyl isobutyl ketone and esters such as butyl acetate are preferable.

The reaction is preferably carried out at a temperature of 130 ° C. or less, more preferably 40 to 130 ° C. When the temperature is lower than 40 ° C., a practically sufficient reaction rate may not be obtained. When the temperature is higher than 130 ° C., the double bond portion may be cross-linked by radical polymerization due to heat, and a gelled product may be generated.

The reaction is usually carried out until the residual isocyanate group is 0.1% by weight or less. The residual isocyanate group concentration is analyzed by gas chromatography, titration method or the like.

[Tricyclodecane dimethanol (X)]
Tricyclodecane dimethanol (X) is not particularly limited, and a commercially available product may be used. Examples of commercially available products include “TCD alcohol DM” (manufactured by Oxea) (tricyclo [5.2.1.0 ^2,6 ] decanedimethanol).

[Polyisocyanate (Y)]
The polyisocyanate (Y) is not particularly limited, but aliphatic polyisocyanates (including those having an alicyclic skeleton) are preferable. Examples of such polyisocyanate (Y) include isophorone diisocyanate, 1,6-hexane diisocyanate (1,6-hexamethylene diisocyanate), 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethyl. Hexamethylene diisocyanate, diisocyanate compounds obtained by hydrogenating aromatic diisocyanates (for example, diisocyanate compounds such as hydrogenated xylylene diisocyanate and hydrogenated diphenylmethane diisocyanate), or trimers of these diisocyanates (biuret, nurate, or adducts); Trifunctional polyisocyanate) and the like. As the trimer of the diisocyanate compound, nurate polyisocyanate is particularly preferable. Polyisocyanate (Y) may be used individually by 1 type, and may be used in combination of 2 or more.

[Hydroxy group-containing (meth) acrylate (Z)]
The hydroxy group-containing (meth) acrylate (Z) is not particularly limited. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy -3-Methoxypropyl (meth) acrylate, monofunctional (meth) acrylate compounds having hydroxyl groups such as lactone adducts (caprolactone adducts, etc.); pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) ) Acrylates, dipentaerythritol tetra (meth) acrylates, dipentaerythritol tri (meth) acrylates, and other lactone adducts such as caprolactone adducts. Relate compounds and the like can be used. Hydroxyl group containing (meth) acrylate (Z) may be used individually by 1 type, and may be used in combination of 2 or more.

[Curable compound (B)]
The active energy ray-curable composition in the present invention includes the urethane (meth) acrylate (A) and other curable compounds (B) [hereinafter sometimes referred to simply as “curable compounds (B)”]. May be included.

The curable compound (B) may be any compound (a monomer or oligomer having a polymerizable group) that is cured by irradiation with active energy rays. For example, a single compound having one (meth) acryloyl group in the molecule. Functional (meth) acrylates, polyfunctional (meth) acrylates having two or more (meth) acryloyl groups in the molecule can be used.

Examples of the monofunctional (meth) acrylate include (meth) acrylate having an aromatic carbon ring such as phenoxyethyl (meth) acrylate and benzyl (meth) acrylate; cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, and dicyclo (Meth) acrylates having an alicyclic skeleton such as pentenyloxyethyl (meth) acrylate; lactone-modified hydroxyalkyl (meth) acrylates such as polycaprolactone-modified hydroxyethyl (meth) acrylate; heterocycles such as acryloylmorpholine (meta ) Acrylate and the like.

Examples of the polyfunctional (meth) acrylate include 1,6-hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Of polyhydric alcohols (aliphatic polyhydric alcohols, alicyclic polyhydric alcohols, etc.) such as pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate ) Polyfunctional monomers such as acrylate; Urethane (meth) acrylate [excluding the urethane (meth) acrylate (A)], epoxy (meth) acrylate, polyester (meth) acrylate and other polyfunctional oligomers It is.

The curable compound (B) is preferably a polyfunctional (meth) acrylate, particularly a polyfunctional (functional 4 or more, preferably 6 to 15, preferably 6 to 12, more preferably 8 to 12 functional). (Meth) acrylate is preferred.

Among the polyfunctional (meth) acrylates, polyfunctional urethane (meth) acrylate (B1) is preferable. The number of functional groups of the polyfunctional urethane (meth) acrylate is preferably 4 or more (for example, 4 to 15 functions, preferably 6 to 15 functions, more preferably 8 to 12 functions).

Polyfunctional urethane (meth) acrylate (B1) can be produced by a known method. For example, (i) a method of reacting a polyisocyanate (Y ′) with a hydroxy group-containing (meth) acrylate (Z ′), (ii) a polyol (X ′), a polyisocyanate (Y ′), and a hydroxy group-containing (meta ) It can be produced by a method of reacting with acrylate (Z ′).

As the polyfunctional urethane (meth) acrylate (B1), schematically described, (Z ′) _m —Y ′ — (Z ′) _m (m is an integer of 1 or more, preferably 1 or 2 ), (Z ′) _m —Y′—X′—Y ′ — (Z ′) _m (m is an integer of 1 or more, preferably 1 or 2).

Examples of the polyol (X ′) include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, and 3-methyl. Diols such as -1,5-pentanediol and tricyclodecane dimethanol; trivalent or higher polyols such as trimethylolpropane, ditrimethylolpropane, pentaerythritol and dipentaerythritol can be used. Polyol (X ') may be used individually by 1 type, and may be used in combination of 2 or more.

Examples of the polyisocyanate (Y ′) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, xylylene diisocyanate, 1,5 -Aromatic diisocyanates such as naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, diphenylmethane diisocyanate; isophorone diisocyanate, 1,6-hexane diisocyanate (1,6-hexamethylene diisocyanate), 2,2,4-trimethylhexa Diisocyanate compounds obtained by hydrogenating methylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, aromatic diisocyanate (for example, hydrogenated) Aliphatic polyisocyanates (including those having an alicyclic skeleton) such as silylene diisocyanate and hydrogenated diphenylmethane diisocyanate); or trimers of these diisocyanates (biuret, nurate, or adducts); trifunctional Polyisocyanate) and the like.

Among these, aliphatic polyisocyanates (including those having an alicyclic skeleton) are preferable. The nurate type polyisocyanate is also preferable. Polyisocyanate (Y ′) may be used alone or in combination of two or more.

Examples of the hydroxy group-containing (meth) acrylate (Z ′) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxy-3- Monofunctional (meth) acrylate compounds having a hydroxyl group such as methoxypropyl (meth) acrylate and these lactone adducts (caprolactone adduct, etc.); pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, Polyfunctional (meth) acrylate compounds having hydroxyl groups such as dipentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, and these lactone adducts (caprolactone adducts, etc.) Such as things. The hydroxy group-containing (meth) acrylate (Z ′) may be used alone or in combination of two or more.

In the present invention, when the curable compound (B) is used, the 4- to 12-functional urethane (meth) acrylate (A) and the curable compound (B) [preferably a polyfunctional (meth) acrylate having 4 or more functions, More preferably, the ratio of the polyfunctional urethane (meth) acrylate having 4 or more functional groups is, for example, the former / the latter (weight ratio) = 10/90 to 99/1, preferably 20/85 to 95/5, more preferably 30/70 to 90/10.

In the active energy ray-curable composition according to the present invention, from the viewpoints of the surface hardness of the target resin film, the suppression of curing shrinkage, and the like, the tetrafunctional or higher functional group containing the 4- to 12-functional urethane (meth) acrylate (A) is used. The total amount of polyfunctional (meth) acrylates (especially polyfunctional urethane (meth) acrylates having 4 or more functionalities) is 30% by weight or more based on the entire curable compound in the active energy ray-curable composition. It is preferably 50% by weight or more, more preferably 60% by weight or more.

The active energy ray-curable composition in the present invention may contain a solvent, a photopolymerization initiator, an additive and the like as required in addition to the curable compound.

The solvent can be appropriately selected in consideration of the solubility of the curable compound and is not particularly limited. Examples thereof include esters such as ethyl acetate, butyl acetate, and isobutyl acetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone. Ketones such as ethylene glycol monomethyl ether; glycol monoether acetates such as diethylene glycol monobutyl ether acetate and propylene glycol monomethyl ether acetate; hydrocarbons such as xylene and toluene; and mixtures thereof.

The content of the solvent in the active energy ray-curable composition is, for example, 0 to 95% by weight, preferably 5 to 90% by weight, and more preferably 10 to 80% by weight.

As the photopolymerization initiator, a known radical photopolymerization initiator can be used, and is not particularly limited. For example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one Diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 4 -(2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, benzoin, benzoin methyl ether, Benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether Le, benzoin phenyl ether, benzyl dimethyl ketal, benzophenone, benzoyl benzoate, methyl benzoyl benzoate, 4-phenyl benzophenone, hydroxybenzophenone, and acrylated benzophenone. These can be used alone or in combination of two or more. In particular, α-hydroxyalkylphenone polymerization initiators such as 1-hydroxycyclohexyl phenyl ketone and α-aminoalkyl such as 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one When used in combination with a phenone-based polymerization initiator, it can be uniformly cured from the surface to the inside of the thin film layer made of the active energy ray-curable composition, and a homogeneous resin film can be obtained.

The amount of the photopolymerization initiator used is, for example, 1 to 20 parts by weight, preferably 1.5 to 10 parts by weight with respect to 100 parts by weight of the curable compound in the active energy ray-curable composition. If it is less than 1 part by weight, there is a risk of causing poor curing. Conversely, if it exceeds 20 parts by weight, an odor derived from the photoinitiator may remain from the cured coating film.

Examples of additives that can be used include fillers (particulate silica, etc.), dyes and pigments, leveling agents, ultraviolet absorbers, light stabilizers, antifoaming agents, dispersants, thixotropic agents, and the like. The amount of these additives to be added is, for example, 0 to 10 parts by weight, preferably 0.05 to 5 parts by weight with respect to 100 parts by weight of the curable compound in the active energy ray-curable composition. In the present invention, since it is possible to increase the film thickness, a resin film having a high surface hardness can be obtained without adding fine particle silica (or without adding filler such as fine particle silica). .

[Manufacture of resin film]
The resin film of the present invention comprises a tetra- to 12-functional urethane (meth) acrylate (A) having a group containing a tricyclodecane skeleton represented by the above formula (1) in the molecule, in an amount of 10 to the entire curable compound. It can manufacture by irradiating an active energy ray to the thin film layer which consists of an active energy ray curable composition containing weight% or more and making it harden | cure.

More specifically, for example, after the active energy ray-curable composition is cast on a substrate or in a mold to form a thin film and dried as necessary (after removing the solvent), the active energy ray The resin film of the present invention can be produced by curing by irradiation.

The substrate is not particularly limited, and examples thereof include polyester resins, polyolefin resins, cellulose resins, polystyrene resins, methacrylic resins, polycarbonate resins, polymethylpentels, polysulfones, polyether ketones, and polyethers. Examples thereof include plastic base materials such as sulfone, polyetherimide, polyimide, and fluorine resin, glass base materials, metal base materials, and the like. From the viewpoint of releasability of the formed resin film, the surface of the substrate is preferably subjected to a release treatment with a release agent (release agent). The material of the mold can be the same as that of the substrate, and the surface thereof is preferably subjected to a release treatment (fluorine resin coating or the like) with a release agent (release agent).

When casting the active energy ray-curable composition on a substrate, for example, airless spray, air spray, roll coat, bar coat, gravure coat, die coat, etc. can be used.

When the active energy ray-curable composition contains a solvent, heat drying with hot air or the like is performed. And the resin film of this invention can be obtained by irradiating the surface of the thinned active energy ray-curable composition with active energy rays such as ultraviolet rays or electron beams to cure the curable compound. A high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, or the like is used as a light source for ultraviolet irradiation. Usually, an irradiation source with a lamp output of about 80 to 300 W / cm is used. In the case of electron beam irradiation, it is preferable to use an electron beam having an energy in the range of 50 to 1000 KeV and to give an irradiation amount of 2 to 5 Mrad. After the active energy ray irradiation, curing may be promoted by heating as necessary.

The thickness of the resin film of the present invention is preferably more than 25 μm, more preferably 100 μm or more, further preferably 200 μm or more, and particularly preferably 500 μm or more in order to ensure high pencil hardness. The upper limit of the thickness of the resin film is not particularly limited, but is, for example, 4 mm, preferably 2 mm. The resin film of the present invention has a high surface hardness, for example, a pencil hardness of 4H or more when the film thickness is 100 μm or more, and a pencil hardness of 9H or more when the film thickness is 500 μm or more.

The resin film of the present invention thus obtained can be used as an optical substrate such as a display substrate such as a liquid crystal display, an organic EL display, a touch panel, and a color filter, and an optical member.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

[Synthesis example of urethane (meth) acrylate]
Below, the synthesis example of urethane (meth) acrylate is demonstrated. Note that “ppm”, “wt%”, and “wt%” in the concentration notation are concentrations with respect to the entire urethane (meth) acrylate-containing product, unless otherwise specified.

(Measurement of isocyanate group concentration)
The isocyanate group concentration was measured as follows. In addition, the measurement was performed under stirring with a stirrer in a 100 mL glass flask.

The blank value was measured as follows. First, 15 mL of a THF solution (0.1N) of dibutylamine was added to 15 mL of THF (tetrahydrofuran). Further, after adding 3 drops of bromophenol blue (diluted in 1% by weight of methanol) to give a blue color, titration was performed with an aqueous HCl solution having a normality of 0.1N. The titration amount of the aqueous HCl solution when the color change was observed was defined as V _b (mL).

The measured isocyanate group concentration was measured as follows. First, a sample of W _s (g) was weighed and dissolved in 15 mL of THF, and 15 mL of dibutylamine in THF (0.1 N) was added. After confirming that the solution was formed, 3 drops of bromophenol blue (diluted in 1% by weight of methanol) were added to give a blue color, followed by titration with an aqueous HCl solution having a normality of 0.1N. The titer of the aqueous HCl solution when the color change was observed was defined as V _s (mL).

The isocyanate group concentration in the sample was calculated by the following calculation formula.
Isocyanate group concentration (% by weight) = (V _b −V _s ) × 1.005 × 0.42 ÷ W _s

(Tricyclodecane dimethanol used in the synthesis example)
TCDDM: Product name "TCD alcohol DM" (Oxea)

(Polyisocyanate used in the synthesis example)
HMDI trimer: Product name “Sumijour N3300” (manufactured by Sumitomo Bayer Urethane Co., Ltd .; 1,6-hexamethylene diisocyanate-derived nurate compound)
IPDI: Product name “VESTANAT IPDI” (Evonik; isophorone diisocyanate)

(Hydroxy group-containing (meth) acrylate used in synthesis example)
HEA: Product name “BHEA” (manufactured by Nippon Shokubai Co., Ltd .; 2-hydroxyethyl acrylate)
PETIA: Product name “PETRA” (manufactured by Cytec; mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate having a hydroxyl value of 120 mg KOH / g)
M-403: Product name “Aronix M-403” (manufactured by Toagosei Co., Ltd .; mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate)

[Synthesis Example 1 / UA1]
A separable flask equipped with a thermometer and a stirrer was charged with 200 g of methyl isobutyl ketone (MIBK) and 225.9 g of IPDI, and the internal temperature was raised to 50 ° C. while stirring. Next, 0.08 g of dibutyltin dilaurate was added, and 99.8 g of TCDDM was added dropwise over 1 hour while maintaining the internal temperature at 50 ° C. After completion of the dropping, stirring was continued for 2 hours at 50 ° C. to complete the reaction of the urethane isocyanate prepolymer. The completion of the reaction was confirmed by confirming that the isocyanate group concentration in the reaction solution was not more than the theoretical end-point isocyanate group concentration (the same applies to other synthesis examples).
In this example, after confirming that the isocyanate group concentration in the reaction solution was equal to or lower than the theoretical end-point isocyanate group concentration (8.12% by weight), the procedure shifted to the next operation.
Next, the internal temperature was raised to 70 ° C., 0.08 g of dibutyltin laurate was added, and 474.3 g of PETIA was added dropwise over 2 hours while maintaining the reaction temperature at 70 ° C. After completion of the dropping, stirring was continued at 70 ° C. for 1 hour. After confirming that the isocyanate group concentration was 0.1% by weight or less, the reaction was terminated, and the skeleton had an organic group in which two hydrogen atoms of the hydroxyl group were removed from tricyclodecane dimethanol, and the number of functional groups was 6 The urethane (meth) acrylate containing material (UA1) was obtained.

[Synthesis Example 2 / UA2]
A separable flask equipped with a thermometer and a stirrer was charged with 200 g of methyl isobutyl ketone (MIBK) and 516.9 g of HMDI trimer, and the internal temperature was raised to 50 ° C. while stirring. Next, 0.08 g of dibutyltin dilaurate was added, and 84.1 g of TCDDM was added dropwise over 1 hour while maintaining the internal temperature at 50 ° C. After completion of the dropping, stirring was continued for 2 hours at 50 ° C. to complete the reaction of the urethane isocyanate prepolymer.
In this example, after confirming that the isocyanate group concentration in the reaction solution was equal to or lower than the theoretical end-point isocyanate group concentration (8.99% by weight), the procedure shifted to the next operation.
Next, the internal temperature was raised to 70 ° C., 0.08 g of dibutyltin laurate was added, and 199.0 g of HEA was added dropwise over 2 hours while maintaining the reaction temperature at 70 ° C. After completion of the dropping, stirring was continued at 70 ° C. for 3 hours. After confirming that the isocyanate group concentration was 0.1% by weight or less, the reaction was terminated, and the backbone had an organic group in which two hydrogen atoms of the hydroxyl group were removed from tricyclodecane dimethanol, and the number of functional groups was 4. The urethane (meth) acrylate containing material (UA2) was obtained.

[Synthesis Example 3 / UA3]
A separable flask equipped with a thermometer and a stirring device was charged with 200 g of methyl isobutyl ketone (MIBK) and 407.4 g of IPDI, and the internal temperature was raised to 50 ° C. while stirring. Next, 0.08 g of dibutyltin dilaurate was added, and 179.8 g of TCDDM was added dropwise over 1 hour while maintaining the internal temperature at 50 ° C. After completion of the dropping, stirring was continued for 2 hours at 50 ° C. to complete the reaction of the urethane isocyanate prepolymer.
In this example, it was confirmed that the isocyanate group concentration in the reaction solution was equal to or lower than the theoretical end-point isocyanate group concentration (9.78% by weight), and then the next operation was performed.
Next, the internal temperature was raised to 70 ° C., 0.08 g of dibutyltin laurate was added, and 212.8 g of HEA was added dropwise over 2 hours while maintaining the reaction temperature at 70 ° C. After completion of the dropping, stirring was continued at 70 ° C. for 1 hour. After confirming that the isocyanate group concentration was 0.1% by weight or less, the reaction was terminated, and the backbone had an organic group obtained by removing two hydrogen atoms of a hydroxyl group from tricyclodecane dimethanol, and the number of functional groups was 2. The urethane (meth) acrylate containing material (UA3) was obtained.

[Synthesis Example 4 / UA4]
A separable flask equipped with a thermometer and a stirrer was charged with 200 g of methyl isobutyl ketone (MIBK) and 153.9 g of IPDI (0.69 mol), and the internal temperature was raised to 70 ° C. while stirring. Next, 0.08 g of dibutyltin dilaurate was added, and 646.1 g of PETIA (1.38 mol as pentaerythritol triacrylate) was added dropwise over 2 hours while maintaining the internal temperature at 70 ° C. After completion of dropping, 0.08 g of dibutyltin laurate was added, and stirring was further continued at 70 ° C. for 3 hours. After confirming that the isocyanate group concentration was 0.1% by weight or less, the reaction was terminated, and the organic group obtained by removing two hydrogen atoms of a hydroxyl group from tricyclodecane dimethanol did not have a skeleton, the number of functional groups was 6 The urethane (meth) acrylate containing material (UA4) was obtained.

[Synthesis Example 5 / UA5]
A separable flask equipped with a thermometer and a stirrer was charged with 200 g of methyl isobutyl ketone (MIBK) and 153.9 g of IPDI (0.69 mol), and the internal temperature was raised to 70 ° C. while stirring. Next, 0.08 g of dibutyltin dilaurate was added, and 1340 g of M-403 (1.38 mol as dipentaerythritol pentaacrylate) was added dropwise over 2 hours while maintaining the internal temperature at 70 ° C. After completion of dropping, 0.08 g of dibutyltin laurate was added, and stirring was further continued at 70 ° C. for 3 hours. After confirming that the isocyanate group concentration was 0.1% by weight or less, the reaction was terminated, and the organic group obtained by removing two hydrogen atoms of the hydroxyl group from tricyclodecane dimethanol did not have a skeleton, the number of functional groups was 10 The urethane (meth) acrylate containing material (UA5) was obtained.

[Synthesis Example 6 / UA6]
A separable flask equipped with a thermometer and a stirrer was charged with 500 g of methyl isobutyl ketone (MIBK) and 160.0 g of isophorone diisocyanate trimer (0.24 mol), and the internal temperature was raised to 70 ° C. while stirring. The temperature rose. Next, 0.04.8 g of dibutyltin dilaurate was added, and 214.8 g of pentaerythritol triacrylate (0.72 mol) was added dropwise over 2 hours while maintaining the internal temperature at 70 ° C. After completion of dropping, 0.08 g of dibutyltin laurate was added, and stirring was further continued at 70 ° C. for 3 hours. After confirming that the isocyanate group concentration was 0.1% by weight or less, the reaction was terminated, and the organic group obtained by removing two hydrogen atoms of a hydroxyl group from tricyclodecane dimethanol did not have a skeleton, the number of functional groups was 9 The urethane (meth) acrylate containing material (UA6) was obtained.

[Examples and Comparative Examples]
The urethane (meth) acrylate-containing material prepared in the synthesis example, the photopolymerization initiator, and methyl isobutyl ketone (MIBK) are mixed in a light-shielding bottle so as to have the composition shown in Table 1 (numbers are parts by weight) An energy ray curable composition was prepared. In the table, photopolymerization initiator 1 is 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF, product name “IRGACURE184”), and photopolymerization initiator 2 is 2-methyl-1- [4- ( Methylthio) phenyl] -2-morpholinopropan-1-one (product name “IRGACURE907” manufactured by BASF). The number in parentheses below “UA1” in the urethane (meth) acrylate column indicates the number of functional groups of the (meth) acryloyl group in one molecule.

Using the energy ray-curable composition prepared above, a resin film was produced by the following film production method 1 or 2.
Film production method 1: An active energy ray-curable composition is flowed on a polyethylene terephthalate (PET) film (base material: thickness 125 μm, trade name “O321E”, manufactured by Mitsubishi Plastics) using a wire bar # 38. After extending, the solvent was removed by drying with a dryer at 80 ° C. After irradiating ultraviolet rays from a high pressure mercury lamp in a nitrogen atmosphere, the resin film having a predetermined thickness (20 μm, 100 μm) was obtained by peeling from the base material.
Film production method 2: The active energy ray-curable composition was cast on a Teflon (registered trademark) petri dish, and then the solvent was removed by drying with a dryer at 80 ° C. After irradiating ultraviolet rays from a high pressure mercury lamp in a nitrogen atmosphere, the resin film having a predetermined thickness (200 μm, 1000 μm) was obtained by peeling from the teflon petri dish.

[Evaluation of resin film]
The characteristics of the resin films obtained in each example and comparative example were evaluated by the following methods. The results are shown in Table 1.

(Pencil hardness)
The measurement was performed according to JIS K-5600.

(Curl, crack)
The resin films obtained in each Example and Comparative Example were visually observed, and the presence and degree of curling and cracking were evaluated according to the following criteria. Even if the curl is “Δ”, it may be used without any problem depending on the application.
<Curl>
○: None △: Slight curling was observed ×: Curl was clearly observed <Crack>
○: None △: Slight cracks were observed ×: Many cracks were observed

As shown in Table 1, the resin films of Examples 1 to 3 using a tetra- or hexafunctional urethane (meth) acrylate having a group containing a tricyclodecane skeleton represented by the formula (1) in the molecule Compared with a bifunctional urethane (meth) acrylate having a group containing a tricyclodecane skeleton represented by the formula (1) in the molecule, while the pencil hardness is “3H” even when the thickness is 20 μm. The resin film of Example 1 has a thickness of 20 μm and a pencil hardness of “H”. In addition, the resin films of Examples 5 to 11 using a tetra- or hexafunctional urethane (meth) acrylate having a group containing a tricyclodecane skeleton represented by the formula (1) in the molecule have a thickness of 200 μm or 1000 μm. In Comparative Examples 2 to 4 using a bifunctional urethane (meth) acrylate having a group containing a tricyclodecane skeleton represented by the formula (1) in the molecule. The resin film has a thickness of 200 μm or 1000 μm and a pencil hardness of “5H” to “7H”. In Comparative Example 5 in which no urethane (meth) acrylate having a group containing a tricyclodecane skeleton represented by the formula (1) is used in the molecule, even if an attempt was made to produce a resin film having a thickness of 1000 μm, the film was self-destructed. A resin film that can withstand use was not obtained.

According to the resin film of the present invention, generation of cracks and curls due to curing shrinkage is remarkably suppressed, the film thickness can be increased, and the surface hardness can be very high. Further, high surface hardness can be obtained without adding a filler such as fine particle silica. Furthermore, the resin film of the present invention is excellent in optical properties such as transparency, thermal properties, and mechanical properties. Therefore, it is useful as an optical substrate such as a liquid crystal display, an organic EL display, a touch panel, a display substrate such as a color filter, an optical member, or the like.

Claims

A resin film obtained by curing an active energy ray-curable composition, wherein the active energy ray-curable composition is represented by the following formula (1):

A resin film comprising 10 to 10% by weight or more of 4- to 12-functional urethane (meth) acrylate (A) having a tricyclodecane skeleton group represented by
The resin film according to claim 1, wherein the thickness exceeds 25 μm.
The resin film according to claim 1, wherein the thickness is 500 μm or more.
In addition to the tetra- to 12-functional urethane (meth) acrylate (A) having a group containing a tricyclodecane skeleton represented by the formula (1) in the molecule, the active energy ray-curable composition is used for other curing. The resin film according to any one of claims 1 to 3, comprising a polyfunctional (meth) acrylate as the functional compound (B).
In addition to the tetra- to 12-functional urethane (meth) acrylate (A) having a group containing a tricyclodecane skeleton represented by the formula (1) in the molecule, the active energy ray-curable composition is used for other curing. The resin film according to any one of claims 1 to 4, comprising a polyfunctional (meth) acrylate having 4 or more functional groups as the functional compound (B).
The total amount of polyfunctional (meth) acrylates having 4 or more functional groups including 4- to 12-functional urethane (meth) acrylate (A) having a group containing a tricyclodecane skeleton represented by the formula (1) in the molecule, The resin film according to any one of claims 1 to 5, which is 30% by weight or more based on the entire curable compound in the active energy ray-curable composition.
A method for producing a resin film according to any one of claims 1 to 6, comprising the following formula (1):

From an active energy ray-curable composition containing 10 to 10% by weight or more of a 4- to 12-functional urethane (meth) acrylate (A) having a group containing a tricyclodecane skeleton represented by A method for producing a resin film, comprising: irradiating an active energy ray to a thin film layer to be cured.