JP7532855B2 - Active energy ray curable composition, cured product thereof, and laminate - Google Patents

Description

The present invention relates to an active energy ray-curable composition, a cured product of the composition, and a laminate such as an electromagnetic radar cover having a cured film of the cured product.

Resin molded products made from polymethyl methacrylate resin, polymethacrylimide resin, polycarbonate resin, polystyrene resin, acrylonitrile-styrene resin, etc. are lightweight, have excellent impact resistance, and good transparency. These resins are used as materials for various automotive lamp lenses, glazing, exteriors, instrument covers, etc.

In recent years, radar devices that use various electromagnetic waves, such as millimeter waves, have been installed on the back of the emblem or front grill on the front of vehicles such as automobiles to detect obstacles ahead and measure the distance to the target object. Since these electromagnetic waves are significantly attenuated by water, the outermost surfaces of emblems, front grills, etc. through which the electromagnetic waves pass are required to have a water-repellent function that makes it difficult for water droplets to adhere and allows water droplets to slide off easily. To meet these requirements, a method is known that imparts water-repellent properties by coating the surface of a resin molded product with a composition that contains a resin having a polydimethylsiloxane structure.

For example, Patent Document 1 describes that a coating film with excellent slip properties can be formed by blending a silicone oil with an active energy ray-curable composition. Patent Document 2 describes that a resin composition having a copolymer of a monomer having a polydimethylsiloxane structure and a crosslinkable reactive group can form a coating film with excellent scratch resistance, hardness, crack resistance, impact resistance, low curl properties, transparency, etc.

JP 2004-299199 A JP 2015-199333 A

However, the coating film described in Patent Document 1 had insufficient water sliding properties. The coating film described in Patent Document 2 also had insufficient water sliding properties, and there was a problem that increasing the amount of polymer that contributes to water sliding properties would result in a deterioration in the appearance of the coating film due to poor compatibility between the polymer and the monomer.

The object of the present invention is to provide an active energy ray-curable composition capable of forming a cured product such as a cured film having a good appearance and excellent water sliding properties, and a laminate having a cured film made of the cured product.

That is, the above object of the present invention can be achieved by the following means [1] to [15].
[1] A copolymer (A) containing a structural unit derived from a silicone macromer (X) and a structural unit derived from a polymerizable monomer (Y) having at least one aromatic ring or alicyclic skeleton, and a difunctional or higher functional (meth)acrylate (B),
the silicone macromer (X) contains an organopolysiloxane structure in its main chain or side chain,
the aromatic ring-containing polymerizable monomer (Y) is an aromatic vinyl compound,
The copolymer (A) contains an aromatic ketone group as a crosslinkable functional group.
An active energy ray-curable composition.
[2] The active energy ray-curable composition according to [1], wherein the silicone macromer (X) has a weight average molecular weight of 500 to 20,000.
[3] The active energy ray-curable composition according to [1] or [2], wherein the weight average molecular weight of the copolymer (A) is 10,000 to 100,000.
[4] The active energy ray-curable composition according to any one of [1] to [3], comprising 0.1 to 60 parts by mass of the copolymer (A) relative to 100 parts by mass of the di- or higher functional (meth)acrylate (B).
[5] The active energy ray-curable composition according to any one of [1] to [4], wherein the di- or higher functional (meth)acrylate (B) contains a urethane (meth)acrylate.
[6] The active energy ray-curable composition according to [5], wherein the urethane (meth)acrylate is a reaction product of a diisocyanate, a polyol, and a mono(meth)acrylate containing a hydroxyl group.
[7] The active energy ray-curable composition according to [ 5 ] or [6], wherein the urethane (meth)acrylate is contained in an amount of 1 to 40 mass% based on the total amount of the di- or higher functional (meth)acrylate (B).
[8] The active energy ray-curable composition according to any one of [1] to [7], wherein the di- or higher functional (meth)acrylate (B) contains a tri- or higher functional (meth)acrylate.
[9] The active energy ray-curable composition according to [8], wherein the tri- or higher functional (meth)acrylate is contained in an amount of 30 to 85 mass % based on the total amount of the di- or higher functional (meth)acrylate (B 1 ).
[10] A cured product obtained by curing the active energy ray-curable composition according to any one of [1] to [9] above.
[11] A laminate having a cured film made of the cured product according to [10] on a surface of a substrate.
[12] The molded article according to [11], wherein the laminate is an electromagnetic radar cover.

The present invention provides an active energy ray-curable composition capable of forming a cured product such as a cured film having good appearance and excellent water sliding performance, and a laminate having a cured film made of the cured product having good appearance and excellent water sliding performance.

The following describes in detail an embodiment of the present invention, but the following description is merely an example of an embodiment of the present invention, and the present invention is not limited to the following description as long as it does not deviate from the gist of the present invention. In this specification, when the expression "~" is used, it is used as an expression including the numerical value or physical property value before and after it. In addition, when the expression "(meth)acrylic" is used in this invention, it means either or both of "acrylic" and "methacrylic". The same applies to "(meth)acrylate", "(meth)acryloyl", etc.

<Active Energy Ray-Curable Composition>
The active energy ray-curable composition of the present invention (hereinafter referred to as the present composition) contains a copolymer (A) and a di- or higher functional (meth)acrylate (B) (hereinafter referred to as the (meth)acrylate (B)).

<Copolymer (A)>
Copolymer (A), a component of the present composition, contains a constituent unit derived from a silicone macromer (X) [hereinafter referred to as macromer (X)] and a constituent unit derived from a polymerizable monomer (Y) having at least one type of aromatic ring or alicyclic skeleton [hereinafter referred to as monomer (Y)]. In other words, copolymer (A) contains a constituent unit derived from macromer (X) in either or both of its main chain or side chain, and further contains a constituent unit derived from monomer (Y) in either or both of its main chain or side chain.

<Production of Copolymer (A)>
The copolymer (A) can be produced, for example, by a method of copolymerizing a macromer (X) and a monomer (Y). In this case, a monomer other than the macromer (X) and the monomer (Y) may be copolymerized. The method for producing the copolymer (A) by this method will be described below.

<Macromer X>
The macromer (X) contributes to the water sliding properties of the cured film of the composition. The silicone skeleton of the macromer (X) may have a straight-chain structure or a branched-chain structure. The silicone skeleton of the macromer (X) may have a hydrocarbon skeleton such as an alkyl group or an alkylene group introduced at the end or inside thereof. The unsaturated bond and the siloxane skeleton of the macromer (X) may be bonded via a hydrocarbon skeleton such as an alkylene group having 1 to 6 carbon atoms.

Examples of the macromer (X) include linear silicone macromer (X1) [hereinafter referred to as macromer (X1)] and branched silicone macromer (X2) [hereinafter referred to as macromer (X2)]. The macromer (X) preferably has an organopolysiloxane structure in the main chain or side chain. Examples of the organopolysiloxane structure include alkylpolysiloxane structures such as polydimethylsiloxane structures. From the viewpoint of ease of obtaining raw materials, the macromer (X1) is preferred as the macromer (X). Examples of the unsaturated bond of the macromer (X1) include a (meth)acryloyl group, a vinyl group, and a (meth)acrylamide group. Among these, the (meth)acryloyl group is preferred from the viewpoint of ease of copolymerization with other monomers.

Examples of macromers (X1) include Silaplane (registered trademark) FM-0711 (number average molecular weight listed in the catalog: 1000), Silaplane FM-0721 (number average molecular weight listed in the catalog: 5000), and Silaplane FM-0725 (number average molecular weight listed in the catalog: 10000) manufactured by JNC; and X-22-174ASX (number average molecular weight listed in the catalog: 900), X-22-174BX (number average molecular weight listed in the catalog: 2300), KF-2012 (number average molecular weight listed in the catalog: 4600), and X-22-2426 (number average molecular weight listed in the catalog: 12000) manufactured by Shin-Etsu Chemical Co., Ltd.

Examples of the macromer (X2) include silicone dendrimers represented by the following structural formulas (1) to (4).

As the macromer (X), for example, mono(meth)acryloyloxypropyl-modified polydimethylsiloxanes such as Silaplane FM-072, Silaplane FM-0721, Silaplane FM-0725, X-22-174ASX, X-22-174BX, KF-2012, and X-22-2426 are suitable because they are easily available industrially.

The molecular weight of the macromer (X) is preferably 500 to 40,000, more preferably 700 to 30,000, and even more preferably 800 to 20,000. The smaller the molecular weight, the easier the compatibility of the macromer (X) with other monomers, and the easier it tends to be to produce the copolymer (A). Also, the larger the molecular weight, the better the water slip properties of the cured film of this composition.

The amount of macromer (X) introduced into copolymer (A) is preferably 5% by mass or more and less than 70% by mass, more preferably 10% by mass or more and less than 60% by mass, and even more preferably 20% by mass or more and less than 50% by mass. The greater the amount introduced, the better the water sliding properties of the cured film, and the smaller the amount introduced, the less unpolymerized macromer (X) there is, so the transparency of the cured film tends to be better.

<Monomer (Y)>
The monomer (Y) is a polymerizable monomer having an aromatic ring or an alicyclic skeleton, and contributes to the water slipping property and appearance of the cured film.
Examples of the monomer (Y) having an aromatic ring include aromatic vinyl compounds such as styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, vinylbiphenyl, vinylanthracene, and vinylxylene; and (meth)acrylates having an aromatic ring such as benzyl (meth)acrylate and phenyl (meth)acrylate.
Examples of the monomer (Y) having an alicyclic skeleton include cycloalkyl (cycloalkenyl) (meth)acrylates such as cyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and dicyclopentenyl (meth)acrylate.

The amount of monomer (Y) introduced into copolymer (A) is preferably 30% by mass or more and less than 90% by mass, more preferably 40% by mass or more and less than 85% by mass, and even more preferably 50% by mass or more and less than 80% by mass. The higher the amount introduced, the better the copolymerization properties when producing copolymer (A), and the lower the amount introduced, the more macromer (X) there is, which tends to improve water slip properties.

<Monomer (Z1)>
In addition to the macromer (X) and the monomer (Y), the copolymer (A) may have a constituent unit derived from a monomer (Z1) having at least one crosslinkable functional group selected from an aromatic ketone group, an epoxy group, and a vinyl ether group [hereinafter referred to as monomer (Z1)], within a range that does not impair performance. In this case, the copolymer (A) has at least one crosslinkable functional group selected from the group consisting of an aromatic ketone group, an epoxy group, and a vinyl ether group. When the active energy ray used for curing the present composition is ultraviolet light, the copolymer (A) containing the crosslinkable functional group can form a stronger bond in the cured film.
An example of a method for introducing a constituent unit derived from the monomer (Z1) into the copolymer (A) is a method of copolymerizing a monomer (Z1) having a polymerizable functional group copolymerizable with the macromer (X) and the monomer (Y) with the macromer (X) and the monomer (Y). As the polymerizable functional group copolymerizable with the macromer (X) and the monomer (Y), a (meth)acryloyl group is preferred.

Examples of monomers (Z1) having an aromatic ketone group include (meth)acrylates such as 4-(meth)acryloyloxybenzophenone, 4-(meth)acryloyloxyethoxybenzophenone, 4-(meth)acryloyloxy-4'-methoxybenzophenone, 4-(meth)acryloyloxyethoxy-4'-methoxybenzophenone, 4-(meth)acryloyloxy-4'-bromobenzophenone, 4-(meth)acryloyloxyethoxy-4'-bromobenzophenone, and 2-[4-(2-hydroxy-2-methyl-1-oxopropyl)phenoxy]ethyl (meth)acrylate.

Examples of the monomer (Z1) having an epoxy group include (meth)acrylates such as glycidyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate glycidyl ether.

Examples of the monomer (Z1) having a vinyl ether group include (meth)acrylates such as 2-(2-vinyloxyethoxy)ethyl (meth)acrylate.

As the monomer (Z1), it is preferable to use an aromatic ketone group from the viewpoint of surface curing properties by ultraviolet light, and among them, it is particularly preferable to use 4-(meth)acryloyloxybenzophenone.
When the copolymer (A) contains a structural unit derived from the monomer (Z1), the type of the structural unit may be only one, or two or more.

The copolymerization amount of monomer (Z1) in copolymer (A) (the proportion of constituent units derived from this monomer) is preferably 0% by mass or more and less than 80% by mass, more preferably 0% by mass or more and less than 60% by mass, and even more preferably 5% by mass or more and less than 40% by mass. When the active energy ray used to cure the present composition is ultraviolet light, the higher the copolymerization amount, the higher the hardness of the cured film tends to be, and the lower the copolymerization amount, the better the water slippage of the cured film tends to be.

<Monomer (Z2)>
In addition to the macromer (X) and the monomer (Y), the copolymer (A) may have a structural unit derived from a monomer (Z2) having at least one functional group selected from the group consisting of an alkoxysilyl group, a hydroxyl group, an isocyanate group, and a carboxyl group [hereinafter referred to as monomer (Z2)], within a range that does not impair performance. In this case, the copolymer (A) has at least one functional group selected from the group consisting of an alkoxysilyl group, a hydroxyl group, an isocyanate group, and a carboxyl group. When the present composition includes a heating step during curing, the copolymer (A) containing the functional group can form a stronger bond in the cured film.
An example of a method for introducing a constituent unit derived from the monomer (Z2) into the copolymer (A) is a method in which a monomer (Z2) having a polymerizable functional group copolymerizable with the macromer (X) and the monomer (Y) is copolymerized with the macromer (X) and the monomer (Y).
Examples of the monomer (Z2) having an alkoxysilyl group include β-(meth)acryloyloxyethyl methyl dimethoxysilane, β-(meth)acryloyloxyethyl methyl diethoxysilane, β-(meth)acryloyloxyethyl dimethyl methoxysilane, β-(meth)acryloyloxyethyl dimethyl ethoxysilane, β-(meth)acryloyloxyethyl trimethoxysilane, β-(meth)acryloyloxyethyl triethoxysilane, γ-(meth)acryloyloxypropyl dimethyl methoxysilane, γ-(meth)acryloyloxypropyl dimethyl ethoxysilane, γ-(meth)acryloyloxypropyl methyl dimethoxysilane, γ-(meth)acryloyloxypropyl methyl diethoxysilane, γ-(meth)acryloyloxypropyl trimethoxysilane, and γ-(meth)acryloyloxypropyl triethoxysilane.
Examples of the monomer (Z2) having a hydroxyl group include (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, propylene glycol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, and glycerin mono(meth)acrylate; N-(2-hydroxyethyl)acrylamide, N-(2-hydroxyethyl)methacrylamide, N-(2-hydroxypropyl) ... Examples of N-substituted (meth)acrylamides include N-(1-hydroxypropyl)acrylamide, N-(1-hydroxypropyl)acrylamide, N-(3-hydroxypropyl)acrylamide, N-(3-hydroxypropyl)methacrylamide, N-(2-hydroxybutyl)acrylamide, N-(2-hydroxybutyl)methacrylamide, N-(3-hydroxybutyl)acrylamide, N-(3-hydroxybutyl)methacrylamide, N-(4-hydroxybutyl)acrylamide, and N-(4-hydroxybutyl)methacrylamide. Preferred (meth)acrylic acid esters include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 3-hydroxypropyl (meth)acrylate, and preferred N-substituted (meth)acrylamides include N-(2-hydroxyethyl)acrylamide and N-(2-hydroxyethyl)methacrylamide. Among these, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are particularly preferred.
Examples of the monomer (Z2) having an isocyanate group include 2-isocyanatoethyl (meth)acrylate, 3-isocyanatopropyl (meth)acrylate, 2-isocyanato-1-methylethyl (meth)acrylate, and methacryloyloxyethoxyethyl isocyanate.
Examples of the monomer (Z2) having a carboxyl group include (meth)acrylic acid, carboxyethyl (meth)acrylate, an adduct of glycerin di(meth)acrylate and succinic anhydride, an adduct of pentaerythritol tri(meth)acrylate and succinic anhydride, and an adduct of pentaerythritol tri(meth)acrylate and phthalic anhydride.
When the copolymer (A) contains a structural unit derived from the monomer (Z2), the type of the structural unit may be only one, or two or more.

The copolymerization amount of monomer (Z2) in copolymer (A) is preferably 0% by mass or more and less than 80% by mass, more preferably 0% by mass or more and less than 60% by mass, and even more preferably 0% by mass or more and less than 40% by mass. When the present composition includes a heating step during curing, the higher the copolymerization amount, the higher the hardness of the cured film tends to be, and the lower the copolymerization amount, the better the water sliding properties of the cured film tends to be.

<Monomer (Z3)>
In addition to the macromer (X) and the monomer (Y), the copolymer (A) may contain a constituent unit derived from a monomer (Z3) other than the monomer (Z1) and the monomer (Z2) [hereinafter referred to as monomer (Z3)], within a range that does not impair the performance.
Examples of the monomer (Z3) include alkyl (alkenyl) (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, behenyl (meth)acrylate, and allyl (meth)acrylate; oxygen atom-containing (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate; N-substituted (meth)acrylics such as (meth)acrylamide, dimethyl (meth)acrylamide, (meth)acryloylmorpholine, isopropyl (meth)acrylamide, and dimethylaminopropylacrylamide. amides; halogen atom-containing (meth)acrylates such as trifluoroethyl (meth)acrylate and heptadecafluorodecyl (meth)acrylate; silicon atom-containing (meth)acrylates such as trimethylsilyl (meth)acrylate, 3-(trimethoxysilyl)propyl (meth)acrylate, 3-(methyldiethoxy)propyl (meth)acrylate and 3-(triethoxy)propyl (meth)acrylate; (meth)acrylates having an ultraviolet absorbing group such as 2-(4-benzoxy-3-hydroxyphenoxy)ethyl methacrylate and 2-(2'-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole; nitrogen atom-containing (meth)acrylates such as tetramethylpiperidinyl (meth)acrylate and diethylaminoethyl (meth)acrylate; vinyl alkanoate compounds; and maleic acid monomers.
When the copolymer (A) contains a structural unit derived from the monomer (Z3), the type of the structural unit may be only one, or two or more.

The copolymerization amount of monomer (Z3) in copolymer (A) is preferably 0% by mass or more and less than 40% by mass, more preferably 0% by mass or more and less than 20% by mass, and even more preferably 0% by mass or more and less than 10% by mass. The higher the copolymerization amount, the better the copolymerization property when producing copolymer (A), and the lower the copolymerization amount, the better the water slipping property of the cured film tends to be.

<Method for introducing a polymerizable double bond into a side chain>
When the active energy ray used for curing the present composition is ultraviolet light, it is preferable that the copolymer (A) has a polymerizable double bond such as a (meth)acryloyl group in the side chain. Examples of the method for introducing a polymerizable double bond into the side chain of the copolymer (A) include a method of reacting a compound having a double bond and a carboxyl group with an acrylic polymer having an epoxy group (Method 1), a method of reacting a compound having a double bond and an epoxy group with an acrylic polymer having a carboxyl group (Method 2), a method of reacting a compound having a double bond and a carboxyl group with an acrylic polymer having a hydroxyl group (Method 3), a method of reacting a compound having a double bond and a hydroxyl group with an acrylic polymer having a carboxyl group (Method 4), a method of reacting a compound having a double bond and a hydroxyl group with an acrylic polymer having an isocyanate group (Method 5), and a method of reacting a compound having a double bond and an isocyanate group with an acrylic polymer having a hydroxyl group (Method 6). The above methods may also be used in combination.

In (Method 1), examples of monomers having epoxy groups used to obtain an acrylic polymer having epoxy groups include glycidyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate, and 3,4-epoxycyclohexylmethyl (meth)acrylate. Among these, glycidyl (meth)acrylate is preferred because of its high reactivity and ease of handling, and glycidyl methacrylate is particularly preferred. These may be used alone or in combination of two or more.

Examples of compounds having a double bond and a carboxyl group in (Method 1) and (Method 3) include (meth)acrylic acid, carboxyethyl (meth)acrylate, an adduct of glycerin di(meth)acrylate and succinic anhydride, an adduct of pentaerythritol tri(meth)acrylate and succinic anhydride, and an adduct of pentaerythritol tri(meth)acrylate and phthalic anhydride. Among these, (meth)acrylic acid and an adduct of pentaerythritol tri(meth)acrylate and succinic anhydride are preferred, and (meth)acrylic acid is particularly preferred. Note that only one type of compound having a double bond and a carboxyl group may be used, or two or more types may be combined.

In (Method 2) and (Method 4), examples of monomers having a carboxyl group used to obtain an acrylic polymer having a carboxyl group include (meth)acrylic acid, carboxyethyl (meth)acrylate, polybasic acid-modified (meth)acrylate, etc. Among these, (meth)acrylic acid is preferred. These may be used alone or in combination of two or more.

In (Method 2), examples of compounds having a double bond and an epoxy group include glycidyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate glycidyl ether. Among these, glycidyl (meth)acrylate is preferred, and glycidyl methacrylate is particularly preferred. These may be used alone or in combination of two or more.

In (Method 3) and (Method 6), examples of monomers having a hydroxyl group used to obtain an acrylic polymer having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and hydroxypropyl (meth)acrylate. These may be used alone or in combination of two or more.

In (Method 4) and (Method 5), examples of compounds having a double bond and a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and hydroxypropyl (meth)acrylate. These may be used alone or in combination of two or more.

In (Method 5), the monomer having an isocyanate group used to obtain an acrylic polymer having an isocyanate group may be, for example, isocyanate ethyl (meth)acrylate. These may be used alone or in combination of two or more.

In (Method 6), examples of compounds having a double bond and an isocyanate group include isocyanate ethyl (meth)acrylate. These may be used alone or in combination of two or more.

Among the above methods, (Method 1) is preferred because it is easy to control the reaction. In (Method 1), the double bond is introduced by a ring-opening/addition reaction between the epoxy group of the acrylic polymer having an epoxy group and the carboxyl group of the compound having a double bond and a carboxyl group.

In (Method 1), the amount of the compound having a double bond and a carboxyl group used is preferably 10 to 150 mol %, more preferably 30 to 130 mol %, and even more preferably 50 to 110 mol %, relative to the number of moles of epoxy groups in the acrylic polymer having epoxy groups. By using the compound in this range, the reaction can be carried out without excess or deficiency, and the amount of residual raw material can be reduced.

<Initiator>
In the production of copolymer (A), it is preferable to use an initiator when copolymerizing macromer (X), monomer (Y), and other optional monomers. The same is true in the case of producing an acrylic polymer having an epoxy group, a carboxyl group, a hydroxyl group, and an isocyanate group, i.e., copolymer (A) before introducing a double bond into the side chain, in (Method 1) to (Method 6).

Various initiators can be used as the initiator. Examples of oil-soluble radical polymerization initiators include azonitriles such as 2,2-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70, Fujifilm Wako Pure Chemical Industries, Ltd.), 2,2'-azobis(2,4-dimethylvaleronitrile) (V-65, Fujifilm Wako Pure Chemical Industries, Ltd.), 2,2'-azobisisobutyronitrile (V-60, Fujifilm Wako Pure Chemical Industries, Ltd.), and 2,2'-azobis(2-methylbutyronitrile) (V-59, Fujifilm Wako Pure Chemical Industries, Ltd.). Allyl compounds: octanoyl peroxide (Perloyl (registered trademark) O, manufactured by NOF Corp.), lauroyl peroxide (Perloyl L, manufactured by NOF Corp.), stearoyl peroxide (Perloyl S, manufactured by NOF Corp.), succinic acid peroxide (Perloyl SA, manufactured by NOF Corp.), benzoyl peroxide (Niper (registered trademark) BW, manufactured by NOF Corp.), isobutyryl peroxide (Perloyl IB, manufactured by NOF Corp.), 2,4-dichlorobenzoyl peroxide (Niper CS diacyl peroxides such as 3,5,5-trimethylhexanoyl peroxide (Peroyl 355, manufactured by NOF Corp.); di-n-propyl peroxydicarbonate (Peroyl NPP-50M, manufactured by NOF Corp.), diisopropyl peroxydicarbonate (Peroyl IPP-50, manufactured by NOF Corp.), bis(4-t-butylcyclohexyl) peroxydicarbonate (Peroyl TCP, manufactured by NOF Corp.), di-2-ethoxyethyl peroxydicarbonate peroxydicarbonates such as di-2-ethoxyhexyl peroxydicarbonate (Perloyl EEP, manufactured by NOF Corp.), di-2-ethoxyhexyl peroxydicarbonate (Perloyl OPP, manufactured by NOF Corp.), di-2-methoxybutyl peroxydicarbonate (Perloyl MBP, manufactured by NOF Corp.), and di(3-methyl-3-methoxybutyl) peroxydicarbonate (Perloyl SOP, manufactured by NOF Corp.); t-butyl hydroperoxide (Perbutyl (registered trademark) H-69, manufactured by NOF Corp.), 1,1,3,3-tetramethylphenyl peroxydicarbonate (Perloyl EEP, manufactured by NOF Corp.), di-2-ethoxyhexyl peroxydicarbonate (Perloyl OPP, manufactured by NOF Corp.), di-2-methoxybutyl peroxydicarbonate (Perloyl MBP, manufactured by NOF Corp.), and di(3-methyl-3-methoxybutyl) peroxydicarbonate (Perloyl SOP, manufactured by NOF Corp.); hydroperoxides such as di-t-butyl peroxide (Perocta (registered trademark) H, manufactured by NOF Corp.); dialkyl peroxides such as di-t-butyl peroxide (Perbutyl D, manufactured by NOF Corp.) and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane (Perhexa (registered trademark) 25B, manufactured by NOF Corp.); α,α'-bis(neodecanoylperoxy)diisopropylbenzene (Diper (registered trademark) ND, manufactured by NOF Corp.) and cumyl peroxide Odecanoate (Percumyl (registered trademark) ND, manufactured by NOF Corp.), 1,1,3,3-tetramethylbutyl peroxyneodecanoate (Perocta ND, manufactured by NOF Corp.), 1-cyclohexyl-1-methylethyl peroxyneodecanoate (Percyclo (registered trademark) ND, manufactured by NOF Corp.), t-hexyl peroxyneodecanoate (Perhexyl (registered trademark) ND, manufactured by NOF Corp.), t-butyl peroxyneodecanoate (Perbutyl ND, manufactured by NOF Corp.), t-hexyl peroxyneodecanoate -Oxypivalate (Perhexyl PV, manufactured by NOF Corp.), t-butyl peroxypivalate (Perbutyl PV, manufactured by NOF Corp.), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (Perocta O, manufactured by NOF Corp.), 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane (Perhexa 250, manufactured by NOF Corp.), 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate (Percyclo O, manufactured by NOF Corp.) , organic peroxides such as peroxyesters such as t-hexylperoxy 2-ethylhexanoate (Perhexyl O, manufactured by NOF Corp.), t-butylperoxy 2-ethylhexanoate (Perbutyl O, manufactured by NOF Corp.), t-butylperoxyisobutyrate (Perbutyl IB, manufactured by NOF Corp.), t-hexylperoxyisopropyl monocarbonate (Perhexyl I, manufactured by NOF Corp.), and t-butylperoxymaleic acid (Perbutyl MA, manufactured by NOF Corp.). The initiator is not particularly limited to these.

The amount of initiator added when producing copolymer (A) is preferably 0.1% by mass or more and less than 10% by mass, more preferably 0.3% by mass or more and less than 6% by mass, and even more preferably 0.5% by mass or more and less than 3% by mass, based on the total amount of macromer (X), monomer (Y), and other optional monomers. The more initiator is added, the better the coatability becomes, and the less initiator is added, the better the water slip properties tend to be.

The copolymer (A) can be produced by a polymerization method such as solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization. The initiator may be used in an appropriate manner for each polymerization method.

<Molecular Weight of Copolymer (A)>
The weight average molecular weight of the copolymer (A) is preferably 1000 to 400000, more preferably 5000 to 300000, and particularly preferably 10000 to 200000. The smaller the weight average molecular weight, the better the compatibility of the copolymer (A) with other components such as the (meth)acrylate (B) in the composition, and the better the appearance of the cured film, whereas the larger the weight average molecular weight, the more firmly the copolymer (A) is fixed to the cured film, and the better the water sliding properties tend to be.

The molecular weight of copolymer (A) is the weight average molecular weight (Mw) calculated using standard polystyrene standards and measured by gel permeation chromatography (GPC).

<Content of Copolymer (A)>
The content of copolymer (A) in this composition is preferably 0.1 mass% or more, more preferably 0.5 mass% or more, even more preferably 1 mass% or more, and particularly preferably 3 mass% or more, based on 100 mass% of (meth)acrylate (B).The content of copolymer (A) is preferably 80 mass% or less, more preferably 70 mass% or less, and even more preferably 60 mass% or less.The content of copolymer (A) is more likely to improve the water slipping of cured film, and is more likely to improve the appearance and hardness of cured film.

<(Meth)acrylate (B)>
The composition contains a (meth)acrylate (B) which is a difunctional or higher functional (meth)acrylate. The (meth)acrylate (B) contributes to improving the scratch resistance of the cured film. The composition contains the (meth)acrylate (B), and thus exhibits good polymerization activity upon irradiation with active energy rays, and can form an excellent cured film having a high crosslink density.

Examples of bifunctional (meth)acrylates (B) include (meth)acrylates having a ring skeleton such as tricyclodecane dimethanol di(meth)acrylate, cyclohexane dimethanol di(meth)acrylate, hydrogenated bisphenol A di(meth)acrylate, and bisphenoxyfluorene ethanol di(meth)acrylate; 1,4-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2,4-diethyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, and 1,9-nonanediol. Examples of such (meth)acrylates include (meth)acrylates having a hydrocarbon skeleton such as di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,11-undecanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 1,13-tridecanediol di(meth)acrylate, and 1,14-tetradecanediol di(meth)acrylate; epoxy (meth)acrylates such as acrylic acid adduct of bisphenol A (specifically, EA-1025 manufactured by Shin-Nakamura Chemical); (meth)acrylates having a polyalkylene skeleton such as tripropylene glycol di(meth)acrylate and polybutylene glycol di(meth)acrylate, alkylene oxide modified products thereof; and polycaprolactone modified products thereof.

Examples of the trifunctional or higher (meth)acrylate (B) include (meth)acrylates having a skeleton derived from trimethylolpropane, such as pentaerythritol triacrylate, dipentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, and neopentyl glycol modified trimethylolpropane di(meth)acrylate; (meth)acrylates having an isocyanurate skeleton, such as ditrimethylolpropane tetraacrylate and bis(2-acryloyloxyethyl)-2-hydroxyethyl isocyanurate; polyfunctional acrylates, such as a pentaerythritol triacrylate adduct to succinic anhydride and a dipentaerythritol pentaacrylate adduct to succinic anhydride; polyester oligomers having acryloyl groups on the side chain or on the side chain and at the end (specifically, Toagosei Polyester (meth)acrylates such as M8030, M7100, etc., manufactured by Epson Corporation; polyfunctional urethane (meth)acrylates such as an isocyanurate of isophorone diisocyanate (IPDI), a reaction product of polytetramethylene glycol (PTMG) and hydroxyethyl acrylate (HEA), and a reaction product of hexamethylene diisocyanate (HDI) and PTMG reactant with pentaerythritol triacrylate; polyester (meth)acrylates having a carbonate bond such as a reaction product of an oligoester using polycarbonate diol and pentaerythritol triacrylate; polyurethane (meth)acrylates such as a reaction product of a diisocyanate and a polyol having three or more functional groups and a hydroxyl group-containing (meth)acrylate; triethoxy (meth)acrylates having an isocyanurate ring such as triethoxyisocyanuric acid triacrylate; alkylene oxide modified products of these; and polycaprolactone modified products of these.

Among these, from the viewpoints of viscosity and curability of the present composition and hardness of the cured film, it is preferable to include pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol triacrylate; alkylene oxide modified products thereof; and caprolactone modified products thereof. Also, from the viewpoints of viscosity and adhesion of the present composition, it is preferable to include urethane (meth)acrylates such as multifunctional urethane (meth)acrylates and polyurethane (meth)acrylates.
The (meth)acrylate (B) may be used alone or in combination of two or more kinds.

<Monofunctional Monomer>
The present composition may contain a monofunctional monomer such as (meth)acrylic acid, a monofunctional (meth)acrylate, or a derivative thereof. Examples of such optional monofunctional monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, sec-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-decyl (meth)acrylate, and the like. acrylate, lauryl (meth)acrylate, n-tridecyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethoxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate, butoxyethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and cationizing agents thereof modified by diethylaminoethyl (meth)acrylate and its modified by a cationizing agent, alkoxy polyalkylene glycol (meth)acrylates such as cyanoethyl (meth)acrylate, methoxy polyethylene glycol (meth)acrylate, and methoxy polypropylene glycol (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloylpropyl phthalate, (meth)acryloyloxyethyl succinate, and 2-isocyanatoethyl (meth)acrylate. These may be used alone or in combination of two or more.

<Photopolymerization initiator>
When ultraviolet light is used to cure the composition, the composition preferably contains a photopolymerization initiator. Examples of photopolymerization initiators include photoradical generators and photoacid generators. The photopolymerization initiator is not particularly limited as long as it can initiate polymerization of a polymerizable component such as (meth)acrylate (B) by irradiation with ultraviolet light. The photopolymerization initiator is preferably one that has good compatibility with other components of the composition.

Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, acetoin, butyroin, toluoin, benzil, benzophenone, p-methoxybenzophenone, diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, methylphenyl glyoxylate, ethylphenyl glyoxylate, 4,4-bis(dimethylaminobenzophenone), 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-hydroxyphenylpropane ... carbonyl compounds such as 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one; sulfur compounds such as tetramethylthiuram disulfide; azo compounds such as azobisisobutyronitrile and azobis-2,4-dimethylvaleronitrile; peroxide compounds such as benzoyl peroxide and di-tert-butyl peroxide; and acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide.
When the present composition is cured with ultraviolet light, the photopolymerization initiator is preferably one having an absorption maximum at 360 to 400 nm. Such photopolymerization initiators generate radicals by ultraviolet light and can effectively polymerize polymerizable components not only on the surface of the coating film but also in its depths, i.e., on the substrate side, thereby improving the adhesion between the cured film and the substrate.
These photopolymerization initiators may be used alone or in combination of two or more.

<Photopolymerization initiator content>
When the present composition is cured by active energy rays other than ultraviolet rays, such as electron beams, a photopolymerization initiator is not necessarily required. However, when curing by ultraviolet rays, the content of the polymerization initiator in the present composition is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, based on 100 parts by mass of the total of the copolymer (A) and the (meth)acrylate (B), in order to prevent adverse effects caused by excessive addition. On the other hand, in order to obtain sufficient addition effect, the content is preferably 0.05 parts by mass or more, and more preferably 0.1 parts by mass or more.

<Organic Solvent>
The present composition may contain an organic solvent. The organic solvent contributes to reducing the viscosity of the present composition. Examples of organic solvents include alcohol-based solvents such as methanol, isopropyl alcohol, n-butanol, diacetone alcohol, 2-methoxyethanol (methyl cellosolve), 2-ethoxyethanol (ethyl cellosolve), 2-butoxyethanol (butyl cellosolve), and tertiary amyl alcohol; carboxylic acid ester-based solvents such as ethyl acetate, n-propyl acetate, butyl acetate, and butyl formate; ketone-based solvents such as methyl ethyl ketone, methyl isobutyl ketone, acetone, and cyclohexanone; amide-based solvents such as dimethylformamide and dimethylacetamide; ether-based solvents such as diethyl ether, methoxytoluene, 1,2-dimethoxyethane, 1,2-dibutoxyethane, 1,1-dimethoxymethane, 1,1-dimethoxyethane, 1,4-dioxane, and tetrahydrofuran; and aliphatic and aromatic hydrocarbon-based solvents such as hexane, pentane, xylene, toluene, and benzene. These may be used alone or in combination of two or more.

<Ultraviolet absorbers, light stabilizers>
The composition may contain a weather resistance imparting agent such as an ultraviolet absorber, a light stabilizer, etc., in order to impart weather resistance to the cured film. As the weather resistance imparting agent, an ultraviolet absorber having a maximum absorption spectrum in the ultraviolet wavelength region that accelerates substrate deterioration is preferred.

Preferred ultraviolet absorbents are compounds derived from triazine, benzophenone, benzotriazole, phenyl salicylate and phenyl benzoate compounds, with benzophenone compounds being preferred because they can be contained in large amounts in the composition, and triazine and benzotriazole compounds being preferred because they can prevent yellowing of substrates such as polycarbonate. More preferred ultraviolet absorbents have a maximum absorption wavelength in the range of 240 to 380 nm.

Examples of ultraviolet absorbents include a mixture of 2-[4-(2-hydroxy-3-dodecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine] and 2-[4-(2-hydroxy-3-tridecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine] (trade name "Tinuvin (registered trademark) 400") manufactured by BASF; Tris[2,4,6-[2-{4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl}]-1,3,5-triazine] {trade name: "Tinuvin 777"}, and other commercially available products such as 2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2 -hydroxy-4-octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, phenyl salicylate, p-tert-butylphenyl salicylate, p-(1,1,3,3-tetramethylbutyl)phenyl salicylate, 3-hydroxyphenyl benzoate, phenylene-1,3-dibenzoate, 2- Examples of such compounds include (2-hydroxy-5'-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-4-octylphenyl)benzotriazole, and 2-(2'-hydroxy-5'-methacryloxyethylphenyl)-2H-benzotriazole. These compounds may be used alone or in combination of two or more.

The content of the ultraviolet absorber in the composition is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, based on the total mass of the copolymer (A) and the (meth)acrylate (B). The higher the content of the ultraviolet absorber, the more likely it is that the weather resistance of the cured film will be improved. The lower the content, the more likely it is that the curability of the composition and the toughness, heat resistance, and abrasion resistance of the cured film will be improved.

<Other ingredients>
The present composition may contain components such as a polymer other than (A), a silane coupling agent, inorganic fine particles, an antioxidant, an anti-yellowing agent, a bluing agent, a pigment, a leveling agent, an antifoaming agent, a thickener, an anti-settling agent, an antistatic agent, and an anti-fogging agent.

<Cured Product>
A cured product obtained by curing the present composition can be obtained, for example, by applying the present composition to a substrate by a known method.

<Substrate>
Examples of the substrate include metals such as zinc-plated steel sheet, zinc alloy-plated steel sheet, stainless steel sheet, and tin-plated steel sheet, polymethyl methacrylate resin, polycarbonate resin, polyester resin, polystyrene resin, ABS resin, AS resin, polyamide resin, polyarylate resin, polymethacrylimide resin, and polyallyl diglycol carbonate resin.
It is particularly effective in improving the scratch resistance of the surfaces of polymethyl methacrylate resin, polycarbonate resin, polystyrene resin and polymethacrylimide resin.

<Coating method>
Coating of the substrate can be carried out by known methods such as brush coating, gravure coater method, die coater method, bar coater method, spray coating method, flow coating method, dip coating method, spin coating method, and curtain coating method. It is preferable to add an organic solvent to the composition, since this improves the coating workability of the composition, the smoothness and uniformity of the coating film, and the adhesion of the cured film to the substrate. In addition, the composition may be heated during coating to reduce the viscosity. If necessary, the composition can be applied multiple times. When curing with ultraviolet light, the film thickness of the composition to be applied is preferably 1 to 50 μm, more preferably 3 to 20 μm.

<Curing method>
The composition coated on the substrate is crosslinked by irradiation with active energy rays to form a cured film. When curing with ultraviolet rays, it is preferable to use a light source such as a high pressure mercury lamp or a metal halide lamp to irradiate with ultraviolet rays having a wavelength of 340 to 380 nm so that the cumulative irradiation amount is 200 to 6000 mJ/ ^cm2 , and more preferably 400 to 4000 mJ/ ^cm2 . The atmosphere in which the ultraviolet rays are irradiated may be air or an inert gas such as nitrogen or argon.

The composition applied to the substrate may be heat-treated before being irradiated with active energy rays such as ultraviolet rays. This heat treatment can be performed by irradiation with a near-infrared lamp, circulating hot air, or the like. A cured film obtained by irradiating active energy rays after heat treatment tends to have improved adhesion over a long period outdoors compared to a film not subjected to heat treatment, since organic solvents are less likely to remain inside the cured film. The conditions for the heat treatment are preferably a substrate surface temperature (hereinafter referred to as heating temperature) of 40 to 90°C and a heating time of 60 to 180 seconds, and more preferably a heating temperature of 50 to 70°C and a heating time of 90 to 120 seconds, from the viewpoint of the appearance and adhesion of the cured film.

<Thickness of cured film>
The thickness of the cured film obtained by curing the present composition is preferably 1 to 50 μm. The thicker the thickness, the easier it is for the effects of the present invention to be exhibited, and the thinner the thickness, the more likely it is that cracks will be reduced.

<Laminate>
The laminate of the present invention is a laminate having a layer of a cured film obtained by curing the composition on a substrate. The laminate of the present invention has excellent water sliding properties and appearance, and is therefore suitable for use in various lamp lenses and glazing for automobiles, as well as radome parts such as emblems and front grilles on the front surface of electromagnetic wave radar devices, and is particularly suitable for use in millimeter wave radar covers.

The present invention will be described in more detail below with examples and comparative examples, but the present invention is not limited to these. In the explanation, "parts" refers to "parts by mass." Measurements and evaluations were performed using the following methods. Examples 1 and 3, which use a copolymer (A) that does not contain an aromatic ketone group as a crosslinkable functional group, are reference examples.

[Measurement and evaluation method]
<Molecular weight>
The molecular weight of the polymer produced in the present invention is a weight average molecular weight (Mw) calculated as standard polystyrene, measured by gel permeation chromatography (GPC) under the following conditions.
Equipment: Waters "e2695",
Column: Tosoh "TSKgel Super H3000+H4000+H6000"
Detector: Differential refractive index detector (RI detector/built-in),
Solvent: tetrahydrofuran,
Temperature: 40° C.
Flow rate: 0.5mL/min,
Injection volume: 10 μL,
Concentration: 0.2% by mass,
Calibration sample: monodisperse polystyrene,
Calibration method: Polystyrene equivalent

<Evaluation Sample>
An active energy ray curable composition was spray-coated onto a polycarbonate resin injection-molded plate (manufactured by TAKIRON CI, product name: "TAKIRON CI PC-1600", clear, thickness 3 mm) so that the thickness of the cured film was 12 to 14 μm, and then dried using a hot air dryer at 60° C. for 180 seconds. The dried sample was then irradiated with ultraviolet light at 1000 mJ/cm ² (integrated ultraviolet light energy with a wavelength of 340 to 380 nm, measured with an ultraviolet light meter UV-351 (product name) manufactured by ORC Seisakusho) using a high-pressure mercury lamp in an air atmosphere to produce a laminate in which a cured film of the active energy ray curable composition was formed on the polycarbonate resin plate, and this was used as an evaluation sample for the following evaluations.

<Appearance>
The appearance of the evaluation sample was evaluated by measuring the diffuse transmittance (haze value) using a haze meter (HM-65W, manufactured by Murakami Color Research Laboratory) in accordance with JIS K7136: 2000. The criteria for judging the appearance are as follows:
Criteria A: Haze value is less than 2% B: Haze value is 2% or more but less than 5% C: Haze value is 5% or more

<Water sliding>
The water sliding property of the evaluation sample was evaluated by measuring the sliding angle of 20 μL of water by the sliding method using a contact angle meter (DM-500, manufactured by Kyowa Interface Science Co., Ltd.). The water sliding property was evaluated based on the following criteria.
Criterion A: The sliding angle of 20 μL of water is greater than 1° and less than 40°.
B: The sliding angle of 20 μL of water is greater than 40° and less than 90°.
C: 20 μL of water does not slide down even at a sliding angle of 90°.

[Preparation of Polymer]
The methods for preparing the polymers used in the examples and comparative examples of the present invention will be described. The copolymers (A-1) to (A-7) prepared in the following examples correspond to the copolymer (A). The copolymers (B-1) and (B-2) prepared in the following examples do not correspond to the copolymer (A). Table 1 shows the amounts of raw materials used in each example.

Synthesis Example 1 <Preparation of Copolymer (A-1)>
127.0 g of toluene, 35.0 g of styrene, 20.0 g of polydimethylsiloxane having a methacryloyl group at one end (manufactured by JNC, Silaplane FM-0721), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (manufactured by NOF Corp., Perocta O) were placed in a 300 ml five-neck separable flask equipped with a stirrer, dropping funnel, cooling condenser, and thermometer. In addition, 105.0 g of toluene, 35.0 g of styrene, 10.0 g of polydimethylsiloxane having a methacryloyl group at one end (manufactured by JNC, Silaplane FM-0721), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (manufactured by NOF Corp., Perocta O) were placed in the dropping funnel. Next, the flask was placed in an oil bath, stirring was started under a nitrogen atmosphere, and the temperature was raised until the internal temperature reached 85°C. 30 minutes after the internal temperature reached 85°C, the monomer mixture was dropped from the dropping funnel over 2 hours and held for 1 hour, after which 0.1 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O, manufactured by NOF Corp.) was added, and 1 hour later, 0.1 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O, manufactured by NOF Corp.) was added, and the reaction was carried out for 5 hours, after which the flask was cooled and 3.0 g of toluene was added to prepare a copolymer (A-1) solution. This solution had a nonvolatile content of 30% by mass, and the weight average molecular weight of the copolymer (A-1) was 53,900.

Synthesis Example 2 <Preparation of Copolymer (A-2)>
Into a 300 ml five-neck separable flask equipped with a stirrer, a dropping funnel, a cooling condenser, and a thermometer, 127.0 g of toluene, 29.0 g of styrene, 6.0 g of 4-methacryloyloxybenzophenone (MBP, manufactured by MCC Unitec), 20.0 g of polydimethylsiloxane having a methacryloyl group at one end (Silaplane FM-0721, manufactured by JNC), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxyate (Perocta O, manufactured by NOF Corp.) were placed. In addition, 105.0 g of toluene, 29.0 g of styrene, 6.0 g of 4-methacryloyloxybenzophenone (MBP, manufactured by MCC Unitec), 10.0 g of polydimethylsiloxane having a methacryloyl group at one end (Silaplane FM-0721, manufactured by JNC), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O, manufactured by NOF Corp.) were added to the dropping funnel. A copolymer (A-2) solution was prepared by the same operation as in Synthesis Example 1 except for the above. This solution had a nonvolatile content of 30% by mass, and the weight average molecular weight of the copolymer (A-2) was 37,200.

Synthesis Example 3 Preparation of Copolymer (A-3)
A 300 ml five-neck separable flask equipped with a stirrer, dropping funnel, cooling condenser, and thermometer was charged with 26.0 g of toluene, 31.0 g of styrene, 4.0 g of glycidyl methacrylate, 20.0 g of polydimethylsiloxane having a methacryloyl group at one end (manufactured by JNC, Silaplane FM-0721), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (manufactured by NOF Corp., Perocta O). In addition, 36.0 g of toluene, 31.0 g of styrene, 4.0 g of glycidyl methacrylate, 10.0 g of polydimethylsiloxane having a methacryloyl group at one end (manufactured by JNC, Silaplane FM-0721), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (manufactured by NOF Corp., Perocta O) were charged into the dropping funnel. Next, the flask was placed in an oil bath, and stirring was started under a nitrogen atmosphere, and the temperature was raised until the internal temperature reached 85°C. 30 minutes after the internal temperature reached 85°C, the monomer mixture was dropped from the dropping funnel over 2 hours and held for 1 hour, after which 0.1 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O, manufactured by NOF Corp.) was added, and 1 hour later, 0.1 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O, manufactured by NOF Corp.) was added and reacted for 5 hours, after which 77.5 g of toluene was added and the internal temperature was raised to 110°C, and further stirred for 3 hours. Next, 0.26 g of 4-methoxyphenol, 0.39 g of triphenylphosphine, and 4.1 g of acrylic acid were added and reacted for 6 hours, after which 107 g of toluene was added and cooled to prepare a copolymer (A-3) solution. The solution had a nonvolatile content of 30% by mass, and the weight average molecular weight of the copolymer (A-3) was 56,300. In addition, the conversion rate of the added acrylic acid (reaction rate to epoxy groups) was 95% as determined by acid value titration.

Synthesis Example 4 <Preparation of Copolymer (A-4)>
Into a 300 ml five-neck separable flask equipped with a stirrer, a dropping funnel, a cooling condenser, and a thermometer, 127.0 g of toluene, 42.0 g of styrene, 6.0 g of 4-methacryloyloxybenzophenone (MBP, manufactured by MCC Unitec), 7.0 g of polydimethylsiloxane having a methacryloyl group at one end (Silaplane FM-0721, manufactured by JNC), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxyate (Perocta O, manufactured by NOF Corp.) were placed. Further, 105.0 g of toluene, 36.0 g of styrene, 6.0 g of 4-methacryloyloxybenzophenone (MBP manufactured by MCC Unitec), 3.0 g of polydimethylsiloxane having a methacryloyl group at one end (Silaplane FM-0721 manufactured by JNC), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O manufactured by NOF Corp.) were added to the dropping funnel. A copolymer (A-4) solution was prepared by the same operation as in Synthesis Example 1 except for the above. This solution had a nonvolatile content of 30% by mass, and the weight average molecular weight of the copolymer (A-4) was 36,400.

Synthesis Example 5 <Preparation of Copolymer (A-5)>
Into a 300 ml five-neck separable flask equipped with a stirrer, a dropping funnel, a cooling condenser, and a thermometer, 127.0 g of toluene, 19.0 g of styrene, 6.0 g of 4-methacryloyloxybenzophenone (MBP, manufactured by MCC Unitec), 30.0 g of polydimethylsiloxane having a methacryloyl group at one end (Silaplane FM-0721, manufactured by JNC), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxyate (Perocta O, manufactured by NOF Corp.) were placed. In addition, 105.0 g of toluene, 19.0 g of styrene, 6.0 g of 4-methacryloyloxybenzophenone (MBP manufactured by MCC Unitec), 20.0 g of polydimethylsiloxane having a methacryloyl group at one end (Silaplane FM-0721 manufactured by JNC), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O manufactured by NOF Corp.) were added to the dropping funnel. A copolymer (A-5) solution was prepared by the same operation as in Synthesis Example 1 except for the above. This solution had a nonvolatile content of 30% by mass, and the weight average molecular weight of the copolymer (A-5) was 34,500.

Synthesis Example 6 <Preparation of Copolymer (A-6)>
Into a 300 ml five-neck separable flask equipped with a stirrer, a dropping funnel, a cooling condenser, and a thermometer, 127.0 g of toluene, 29.0 g of styrene, 6.0 g of 4-methacryloyloxybenzophenone (MBP manufactured by MCC Unitec), 20.0 g of a silicone dendrimer having a methacryloyl group at one end and represented by the structural formula (1) (manufactured by Silicon Material Development Co., Ltd.), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxyate (Perocta O manufactured by NOF Corp.). In addition, 105.0 g of toluene, 29.0 g of styrene, 6.0 g of 4-methacryloyloxybenzophenone (MBP manufactured by MCC Unitec), 10.0 g of a silicone dendrimer having a methacryloyl group at one end and represented by the structural formula (1) (manufactured by Silicon Material Development Co., Ltd.), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O manufactured by NOF Corp.) were added to the dropping funnel. A copolymer (A-6) solution was prepared by the same operation as in Synthesis Example 1 except for the above. The nonvolatile content of this solution was 30% by mass, and the weight average molecular weight of the copolymer (A-6) was 47,900.

Synthesis Example 7 Preparation of Copolymer (A-7)
Into a 300 ml five-neck separable flask equipped with a stirrer, a dropping funnel, a cooling condenser, and a thermometer, 127.0 g of toluene, 29.0 g of cyclohexyl methacrylate, 6.0 g of 4-methacryloyloxybenzophenone (MBP, manufactured by MCC Unitec), 20.0 g of polydimethylsiloxane having a methacryloyl group at one end (Silaplane FM-0721, manufactured by JNC), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxyate (Perocta O, manufactured by NOF Corp.) were placed. In addition, 105.0 g of toluene, 29.0 g of cyclohexyl methacrylate, 6.0 g of 4-methacryloyloxybenzophenone (MBP, manufactured by MCC Unitec), 10.0 g of polydimethylsiloxane having a methacryloyl group at one end (Silaplane FM-0721, manufactured by JNC), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O, manufactured by NOF Corp.) were added to the dropping funnel. A copolymer (A-7) solution was prepared by the same operation as in Synthesis Example 1 except for the above. This solution had a nonvolatile content of 30% by mass, and the weight average molecular weight of the copolymer (A-7) was 46,400.

Synthesis Example 8 Preparation of Comparative Copolymer (R-1)
Into a 300 ml five-neck separable flask equipped with a stirrer, a dropping funnel, a cooling condenser, and a thermometer, 127.0 g of toluene, 14.0 g of methyl methacrylate, 15.0 g of stearyl methacrylate, 6.0 g of 4-methacryloyloxybenzophenone (MBP, manufactured by MCC Unitec), 20.0 g of polydimethylsiloxane having a methacryloyl group at one end (Silaplane FM-0721, manufactured by JNC), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxyate (Perocta O, manufactured by NOF Corp.) were placed. In addition, 105.0 g of toluene, 14.0 g of methyl methacrylate, 15.0 g of stearyl methacrylate, 6.0 g of 4-methacryloyloxybenzophenone (MBP manufactured by MCC Unitec), 10.0 g of polydimethylsiloxane having a methacryloyl group at one end (Silaplane FM-0721 manufactured by JNC), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O manufactured by NOF Corp.) were added to the dropping funnel. A comparative copolymer (R-1) solution was prepared by the same operation as in Synthesis Example 1 except for this. This solution had a nonvolatile content of 30% by mass, and the weight average molecular weight of the comparative copolymer (R-1) was 48,200.

Synthesis Example 9 Preparation of Comparative Copolymer (R-2)
127.0 g of toluene, 49.0 g of styrene, 6.0 g of 4-methacryloyloxybenzophenone (MBP, manufactured by MCC Unitec), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O, manufactured by NOF Corp.) were added to a 300 ml five-neck separable flask equipped with a stirrer, a dropping funnel, a cooling condenser, and a thermometer. In addition, 105.0 g of toluene, 39.0 g of styrene, 6.0 g of 4-methacryloyloxybenzophenone (MBP, manufactured by MCC Unitec), and 0.25 g of 1,1,3,3-tetramethylbutyl 2-ethylhexaneperoxy acid (Perocta O, manufactured by NOF Corp.) were added to the dropping funnel. A comparative copolymer (R-2) solution was prepared by the same operation as in Synthesis Example 1 except for this. This solution had a nonvolatile content of 30% by mass, and the weight average molecular weight of the comparative copolymer (R-2) was 28,800.

Synthesis Example 10 Preparation of Urethane Acrylate (B1)
In a flask equipped with a dropping funnel with a heat retention function, a reflux condenser, a stirring blade and a temperature sensor, 530 g (2 mol) of dicyclohexylmethane diisocyanate and 300 ppm of di-n-butyltin dilaurate were charged and heated to 40 ° C. Then, 800 g (weight average molecular weight 800) and 650 g (1 mol) of polycarbonate diol (trade name: Kuraray Polyol C-770, manufactured by Kuraray) were dropped over 4 hours as a polyol compound. After stirring at 40 ° C. for 2 hours, the temperature was raised to 70 ° C. over 1 hour. Then, 232 g (2 mol) of 2-hydroxyethyl acrylate (HEA) was dropped over 2 hours and further stirred for 2 hours to prepare urethane acrylate (B1). The obtained product had a non-volatile content of 75%, and the weight average molecular weight of the urethane acrylate (B1) was 1500.

Synthesis Example 11 <Preparation of other acrylic copolymer (C)>
300g of toluene and 175g of butyl fumarate were charged into a 2L four-neck flask, and the liquid temperature in the flask was heated to 110°C. Next, the liquid in the flask was stirred while maintaining the internal temperature at 110°C, and a monomer-containing mixture consisting of 200g of styrene, 125g of 2-hydroxyethyl methacrylate, and 5g of azobisisobutylnitrile was dripped into the flask at a constant rate over 4 hours, followed by adding 200g of butyl acetate. Thereafter, 1g of azobisisobutylnitrile was added to the flask every hour for a total of four times (total of 4g), and the mixture was stirred for another 2 hours to prepare an acrylic copolymer (C). The resulting product had a non-volatile content of 50% and a weight average molecular weight of the acrylic copolymer (C) of 25,000.

<Preparation of Blend Solution 1>
22 parts of a caprolactone-modified DPHA (DPCA-20, manufactured by Nippon Kayaku Co., Ltd.) as a (meth)acrylate (B) and 16 parts of the urethane acrylate (B1) prepared in Synthesis Example 10 were mixed, and 0.9 parts of benzophenone as a photopolymerization initiator was added thereto. Then, the mixture was diluted with propylene glycol monomethyl ether to a nonvolatile content of 32 mass%, thereby preparing a blended solution 1.

<Preparation of Blend Solution 2>
20 parts of DPHA (DPHA, manufactured by Nippon Kayaku Co., Ltd.) as the (meth)acrylate (B) and 20 parts of the acrylic polymer (C) prepared in Synthesis Example 11 as other components were mixed, and 0.9 parts of benzophenone was added thereto as a photopolymerization initiator. Then, the mixture was diluted with propylene glycol monomethyl ether to a non-volatile content of 30 mass%, thereby preparing blend solution 2.

<Examples 1 to 8 and Comparative Examples 1 to 3>
An active energy ray-curable composition was prepared by blending the copolymer and the blend liquid in the blending ratio shown in Table 2. The composition was subjected to various evaluations, and the results are shown in Table 2.

The abbreviations in Table 1 are as follows.
FM-0721: JNC Silaplane FM-0721 (catalog number average molecular weight 5000)
X2-1: Silicon dendrimer represented by the above structural formula (1) (manufactured by Silicon Material Development Co., Ltd.)
St: styrene CHMA: cyclohexyl methacrylate MBP: 4-methacryloyloxybenzophenone (MBP manufactured by MCC Unitech)
MMA: methyl methacrylate DTDMA: stearyl methacrylate GMA: glycidyl methacrylate AA: acrylic acid

In Table 2, "x" means that the droplet did not move even when the tilt angle was changed to 90 degrees, and the sliding angle could not be measured.

As shown in Table 2, the active energy ray curable composition of Comparative Example 1 used a copolymer that did not contain a structural unit derived from a monomer (Y) having an aromatic ring or an alicyclic skeleton, and therefore the water slippage and appearance (compatibility) of the cured film were low. The active energy ray curable composition of Comparative Example 2 used a copolymer that did not contain a structural unit derived from a macromer (X), and therefore the water slippage of the cured film was low. The active energy ray curable composition of Comparative Example 3 did not contain a copolymer, and therefore the water slippage of the cured film was low.

The cured film obtained from the active energy ray-curable composition of the present invention has excellent water sliding properties and appearance. Therefore, the active energy ray-curable composition of the present invention is suitable as a hard coat material for various lamp lenses and glazing for automobiles, as well as for radome parts such as emblems and front grilles on the front of electromagnetic wave radar devices, and is particularly suitable for use as a hard coat material for millimeter wave radar covers.

Claims (12)

The present invention relates to a copolymer (A) having a structural unit derived from a silicone macromer (X) and a structural unit derived from a polymerizable monomer (Y) having at least one type of aromatic ring or alicyclic skeleton, and a di- or higher functional (meth)acrylate (B),
the silicone macromer (X) contains an organopolysiloxane structure in its main chain or side chain,
the aromatic ring-containing polymerizable monomer (Y) is an aromatic vinyl compound,
The copolymer (A) contains an aromatic ketone group as a crosslinkable functional group.
An active energy ray-curable composition. The active energy ray-curable composition according to claim 1, wherein the weight average molecular weight of the silicone macromer (X) is 500 to 20,000. The active energy ray-curable composition according to claim 1 or 2, wherein the weight average molecular weight of the copolymer (A) is 10,000 to 100,000. The active energy ray curable composition according to any one of claims 1 to 3, comprising 0.1 to 60 parts by mass of the copolymer (A) per 100 parts by mass of the difunctional or higher (meth)acrylate (B). The active energy ray curable composition according to any one of claims 1 to 4, wherein the difunctional or higher (meth)acrylate (B) contains a urethane (meth)acrylate. The active energy ray curable composition according to claim 5, wherein the urethane (meth)acrylate is a reaction product of a diisocyanate, a polyol, and a mono(meth)acrylate containing a hydroxyl group. The active energy ray-curable composition according to claim 5 or 6 , wherein the urethane (meth)acrylate is contained in an amount of 1 to 40 mass% based on the total amount of the di- or higher functional (meth)acrylate (B). The active energy ray curable composition according to any one of claims 1 to 7, wherein the difunctional or higher (meth)acrylate (B) contains a trifunctional or higher (meth)acrylate. The active energy ray-curable composition according to claim 8, wherein the tri- or higher functional (meth)acrylate is contained in an amount of 30 to 85 mass % based on the total amount of the di- or higher functional (meth)acrylate (B 1 ). A cured product obtained by curing the active energy ray-curable composition according to any one of claims 1 to 9. A laminate having a cured film made of the cured product according to claim 10 on the surface of a substrate. The laminate according to claim 11, which is an electromagnetic radar cover.