Active energy ray-curable resin composition, cured product thereof, and protective film

Abstract

The present invention provides an active energy ray-curable resin composition capable of forming a film having high adhesion to a substrate, excellent weather resistance, and excellent tensile elongation properties at high temperatures, as well as a cured product thereof and a protective film. [Solution] The present invention provides an active energy ray-curable resin composition containing a urethane acrylate, the urethane acrylate having structural units derived from an alicyclic isocyanate compound, an aromatic isocyanate compound, a polycarbonate diol, and a (meth)acrylic compound having a hydroxyalkyl group, and the polycarbonate diol has an alicyclic structure or a heterocycle.

Description

[Technical field]

[0001] The present invention relates to an active energy ray-curable resin composition, a cured product thereof, and a protective film. [Background technology]

[0002] Since active energy ray-curable resin compositions such as ultraviolet rays have the property of being cured by irradiation with active energy rays, they can be used to produce, for example, protective films used to protect various substrates. In addition, active energy ray-curable resin compositions are also used in coatings for various substrates, hard coat agents, adhesives, and the like.

[0003] Various active energy ray-curable resin compositions have been proposed. For example, Patent Document 1 discloses an active energy ray-curable resin composition containing, as a main component, a urethane acrylate obtained by reacting a diisocyanate compound, a polycarbonate diol compound, and a hydroxyalkyl (meth)acrylate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-037411 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, the value of active energy ray-curable resin compositions as protective films for protecting various substrates has been increasing. For this reason, active energy ray-curable resin compositions capable of forming films having excellent adhesion to various substrates and excellent weather resistance are required.

[0006] In addition, since the surface of the substrate to be protected is not flat but may have a curved or curved shape, it is necessary to attach the protective film to the substrate while pulling the film in order to strongly adhere the protective film to the substrate. For this reason, the protective film formed from the active energy ray-curable resin composition is also required to have excellent tensile elongation properties, particularly tensile elongation properties at high temperatures.

[0007] From such a viewpoint, there has been a demand for an active energy ray-curable resin composition capable of forming a film having high adhesion to a substrate, excellent weather resistance, and excellent tensile elongation properties at high temperatures.

[0008] The present invention has been made in view of the above, and has an object to provide an active energy ray-curable resin composition capable of forming a film having high adhesion to a substrate and excellent weather resistance, and further having excellent tensile elongation properties at high temperatures, and a cured product thereof, and a protective film. [Means for solving the problem]

[0009] As a result of intensive research into achieving the above object, the inventors have found that the above object can be achieved by using a urethane acrylate having a specific structural unit as an essential component, and have thus completed the present invention.

[0010] That is, the present invention includes, for example, the subject matter described in the following sections. Item 1 An active energy ray-curable resin composition containing a urethane acrylate, The urethane acrylate is Alicyclic isocyanate compounds, Aromatic isocyanate compounds, Polycarbonate diol, and (Meth)acrylic compounds having hydroxyalkyl groups having a structural unit derived from The polycarbonate diol has an alicyclic structure or a heterocyclic structure. Section 2 Item 2. The active energy ray-curable resin composition according to item 1, wherein the polycarbonate diol has an alicyclic structure or a heterocyclic ring in a main chain. Section 3 Item 3. The active energy ray-curable resin composition according to item 1 or 2, which is for use in a protective film. Section 4 Item 4. A cured product of the active energy ray-curable resin composition according to any one of items 1 to 3. Section 5 Item 5. A protective film comprising the cured product according to item 4. Effect of the Invention

[0011] The active energy ray-curable resin composition of the present invention can form a film that has high adhesion to a substrate, is excellent in weather resistance, and is also excellent in tensile elongation properties at high temperatures. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present invention will be described in detail. In this specification, the expressions "containing" and "comprise" include the concepts of "containing", "comprises", "consists essentially of" and "consists only of".

[0013] In the numerical ranges described in stages in this specification, the upper or lower limit of a certain numerical range can be arbitrarily combined with the upper or lower limit of another numerical range. In the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in an example or a value that can be unambiguously derived from an example. In addition, in this specification, a numerical value connected with "~" means a numerical range that includes the numerical values ​​before and after "~" as the lower and upper limits.

[0014] The active energy ray curable resin composition of the present invention contains a urethane acrylate. The urethane acrylate has structural units derived from an alicyclic isocyanate compound, an aromatic isocyanate compound, a polycarbonate diol, and a (meth)acrylic compound having a hydroxyalkyl group. The polycarbonate diol has an alicyclic structure or a heterocycle.

[0015] In this specification, "(meth)acrylic" means "acrylic" or "methacrylic", "(meth)acrylate" means "acrylate" or "methacrylate", and "(meth)allyl" means "allyl" or "methallyl".

[0016] The active energy ray curable resin composition of the present invention contains a urethane acrylate containing all of the above structural units, and thus can form a film having high adhesion to a substrate, excellent weather resistance, and excellent tensile elongation properties at high temperatures. Therefore, the active energy ray curable resin composition of the present invention can be suitably used as a raw material for forming a film.

[0017] The urethane acrylate contained in the active energy ray curable resin composition of the present invention is obtained by reacting an alicyclic isocyanate compound, an aromatic isocyanate compound, a polycarbonate diol, and a (meth)acrylic compound having a hydroxyalkyl group. Hereinafter, the alicyclic isocyanate compound is referred to as "(A1) alicyclic isocyanate compound", the aromatic isocyanate compound is referred to as "(A2) aromatic isocyanate compound", the polycarbonate diol is referred to as "(B1) polycarbonate diol", and the (meth)acrylic compound having a hydroxyalkyl group is referred to as "(C1) hydroxyalkyl group-containing (meth)acrylic compound". These compounds may also be abbreviated as compound (A1), compound (A2), compound (B1), and compound (C1), respectively.

[0018] (A1) Alicyclic isocyanate compound The urethane acrylate contains a structural unit based on an (A1) alicyclic isocyanate compound. The (A1) alicyclic isocyanate compound is an isocyanate compound having an alicyclic structure in the molecule. In particular, the (A1) alicyclic isocyanate compound is a polyisocyanate having at least two isocyanate groups in the molecule.

[0019] The urethane acrylate contains a structural unit based on the (A1) alicyclic isocyanate compound, and therefore the active energy ray-curable resin composition of the present invention can easily form a film that is excellent in both weather resistance and elongation properties at high temperatures.

[0020] An alicyclic structure is one that contains one or more saturated and / or unsaturated carbon ring structures that do not have aromaticity. The number of such carbon ring structures may be two or more. The carbon ring structure may have a branch of an aliphatic hydrocarbon structure. The carbon ring structure is bonded directly or via a hydrocarbon chain to the hydrocarbon chain of the polymer backbone.

[0021] Examples of the carbon ring structure include monocyclic structures such as cycloalkane structures such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, and cyclododecane, and cycloalkene structures such as cyclopropene, cyclobutene, cyclopropene, cyclohexene, cycloheptene, and cyclooctene. Examples of bicyclic structures include bicyclic alkane structures such as bicycloundecane, and bicyclic alkene structures such as norbornene and norbornadiene, which can be suitably used. Among these, a carbon ring structure having 4 to 8 carbon atoms is preferred, a monocyclic carbon ring structure having 4 to 8 carbon atoms is more preferred, a carbon ring structure of a monocyclic cycloalkane structure having 4 to 8 carbon atoms is even more preferred, and a cyclohexane structure is particularly preferred.

[0022] The alicyclic structure may have a substituent. Examples of the "substituent" in this specification include an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, a halogen atom, a carboxyl group, a carbonyl group, a sulfonyl group, a sulfone group, and a cyano group.

[0023] The (A1) alicyclic isocyanate compound can have one or more of the alicyclic structures in the molecule, preferably has two or more, and more preferably has two. The (A1) alicyclic isocyanate compound also preferably has two or more, and more preferably has two isocyanate groups in the molecule.

[0024] Specific examples of the (A1) alicyclic isocyanate compound include isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (also known as 4,4'-methylenebis(cyclohexyl isocyanate), 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, and 1,3-bis(isocyanatemethyl)cyclohexane.

[0025] (A2) Aromatic isocyanate compounds The urethane acrylate contains structural units based on (A2) an aromatic isocyanate compound. (A2) The aromatic isocyanate compound is an isocyanate compound having an aromatic ring structure in the molecule. In particular, (A2) the aromatic isocyanate compound is a polyisocyanate having at least two isocyanate groups in the molecule.

[0026] Since the urethane acrylate contains a structural unit based on the aromatic isocyanate compound (A2), the active energy ray-curable resin composition of the present invention is likely to form a film that is excellent in both adhesion to a substrate and elongation properties at high temperatures.

[0027] The aromatic ring structure may be a monocyclic, bicyclic, tricyclic, or tetracyclic aryl group, for example, having from 6 to 18 carbon atoms. Examples of the aryl group include phenyl, 1-naphthyl, 2-naphthyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, and 2-anthryl.

[0028] The aromatic isocyanate compound (A2) preferably has one or more aromatic ring structures in the molecule, more preferably has one or two, and the alicyclic isocyanate compound (A1) preferably has two or more isocyanate groups in the molecule, more preferably has two.

[0029] Specific examples of the (A2) aromatic isocyanate compound include 2,4-tolylene diisocyanate (also known as tolylene-2,4-diisocyanate), 2,6-tolylene diisocyanate (also known as tolylene-2,6-diisocyanate), 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, 4,4'-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, and 1,4-phenylene diisocyanate.

[0030] (B1) Polycarbonate diol The urethane acrylate contains structural units based on (B1) polycarbonate diol. (B1) Polycarbonate diol is a diol compound having an alicyclic structure or a heterocyclic ring in the molecule.

[0031] Since the urethane acrylate contains a structural unit based on the (B1) polycarbonate diol, the active energy ray-curable resin composition of the present invention can easily form a film that has both excellent adhesion to a substrate and excellent elongation properties at high temperatures.

[0032] In the polycarbonate diol (B1), the alicyclic structure has the same meaning as the alicyclic structure in the alicyclic isocyanate compound (A1). The alicyclic structure in the polycarbonate diol (B1) preferably has a carbon ring structure having 4 to 8 carbon atoms, more preferably has a monocyclic carbon ring structure having 4 to 8 carbon atoms, further preferably has a carbon ring structure of a monocyclic cycloalkane structure having 4 to 8 carbon atoms, and particularly preferably has a cyclohexane structure.

[0033] In the (B1) polycarbonate diol, the heterocycle means, for example, a ring structure in which at least one (preferably one) of the carbon atoms forming the alicyclic structure is replaced with a heteroatom. Examples of the heteroatom include a nitrogen atom, an oxygen atom, a sulfur atom, and a phosphorus atom.

[0034] The (B1) polycarbonate diol preferably has an alicyclic structure or a heterocyclic ring in the main chain. In this case, the active energy ray-curable resin composition of the present invention is likely to form a film having high adhesion to a substrate and excellent elongation properties at high temperatures.

[0035] The (B1) polycarbonate diol more preferably has an alicyclic structure in the main chain, further preferably has a carbon ring structure of a monocyclic cycloalkane structure having 4 to 8 carbon atoms in the main chain, and particularly preferably has a cyclohexane structure in the main chain.

[0036] The polycarbonate diol (B1) can be, for example, a diol compound having a structural unit represented by the following formula (1).

[0037] [ka]

[0038] In formula (1), R represents a divalent group based on the above-mentioned alicyclic structure or heterocyclic ring. Therefore, R may be, for example, a divalent group based on a carbon ring structure of a monocyclic cycloalkane structure having 4 to 8 carbon atoms, and a specific example is a divalent group based on a cyclohexane structure, that is, a cyclohexylene group (-CH 10 It is particularly preferred that

[0039] When the (B1) polycarbonate diol is a diol compound having a structural unit represented by the formula (1), both ends are, for example, R-OH.

[0040] When the polycarbonate diol (B1) is a diol compound having a structural unit represented by the above formula (1), it may have other structural units in addition to the structural unit. For example, the polycarbonate diol (B1) may be a diol compound having a structural unit represented by the following formula (2) in addition to the structural unit represented by the above formula (1).

[0041] [ka]

[0042] In formula (2), R 1 R represents a chain alkylene group. The chain alkylene group is, for example, an alkylene group having 20 or less carbon atoms, preferably 16 or less, more preferably 12 or less, even more preferably 10 or less, and particularly preferably 8 or less. The number of carbon atoms in the chain alkylene group is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more. 1 The chain alkylene group as R may be linear or may have a branched chain. 1 Specific examples of the alkyl group include -CH2-, -C2H4-, -C3H6-, -C4H8-, and -C6H 12 -It is.

[0043] When the polycarbonate diol (B1) contains a diol compound having a structural unit represented by the formula (2) and such a structural unit is arranged at a terminal, the terminal of the structural unit represented by the formula (2) may be, for example, R 1 -OH.

[0044] The (B1) polycarbonate diol may be a diol compound consisting of only the structural unit represented by the formula (1), or may be a diol compound having both the structural unit represented by the formula (1) and the structural unit represented by the formula (2).

[0045] When the (B1) polycarbonate diol is a diol compound having both the structural unit represented by the formula (1) and the structural unit represented by the formula (2), the content ratio of the structural unit represented by the formula (1) is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, even more preferably 40 mol% or more, and particularly preferably 50 mol% or more, based on the total amount of the structural unit represented by the formula (1) and the structural unit represented by the formula (2). The content ratio of the structural unit represented by the formula (1) may be 70 mol% or more based on the total amount of the structural unit represented by the formula (1) and the structural unit represented by the formula (2).

[0046] When the polycarbonate diol (B1) is a diol compound having both the structural unit represented by the formula (1) and the structural unit represented by the formula (2), the polycarbonate diol (B1) may further contain other structural units, or may be a diol compound consisting only of the structural unit represented by the formula (1) and the structural unit represented by the formula (2).

[0047] When the polycarbonate diol (B1) is a diol compound having both the structural unit represented by the formula (1) and the structural unit represented by the formula (2), the polycarbonate diol (B1) may be a random polymer in which these structural units are randomly arranged, or may be a block polymer or an alternating polymer.

[0048] In addition, when the (B1) polycarbonate diol is a diol compound consisting only of the structural unit represented by the formula (1), it may also contain a diol compound having a structural unit represented by the formula (2) separately. That is, the (B1) polycarbonate diol may be a mixture.

[0049] The number average molecular weight of the (B1) polycarbonate diol is not particularly limited, and is, for example, preferably 400 or more, more preferably 600 or more, and even more preferably 800 or more, and is preferably 100,000 or less, more preferably 10,000 or less, even more preferably 5,000 or less, and particularly preferably 2,000 or less.

[0050] In the present invention, the number average molecular weight can mean a value obtained by GPC measurement. Specifically, it is measured by a GPC apparatus using tetrahydrofuran (THF) as a solvent, and is calculated as a polystyrene equivalent value. Specific measurement conditions are as follows. Column: Tosoh polystyrene gel column (TSKgel G4000HXL + TSKgel G3000HXL + TSKgel G2000HXL + 2 TSKgel G1000HXL connected in series in this order) Column temperature: 40℃ Detector: Differential refractive index detector (Shimadzu RID-6A) Flow rate: 1ml / min

[0051] In addition, when the polycarbonate diol (B1) is a commercially available product and its number average molecular weight is known by a manufacturer's guaranteed value or the like, this value can be used as the number average molecular weight of the polycarbonate diol (B1).

[0052] The method for producing the polycarbonate diol (B1) is not particularly limited, and for example, the polycarbonate diol (B1) can be produced by a known method for producing a carbonate diol. The polycarbonate diol (B1) can also be obtained from commercial products. Commercially available products of the polycarbonate diol (B1) include the "ETERNACOLL (registered trademark)" series from UBE Corporation, and specific examples thereof include "ETERNACOLL (registered trademark) UC-100", "ETERNACOLL (registered trademark) UM-90 (3 / 1)", "ETERNACOLL (registered trademark) UM-90 (1 / 1)", and "ETERNACOLL (registered trademark) UM-90 (1 / 3)".

[0053] (C1) Hydroxyalkyl group-containing (meth)acrylic compound The urethane acrylate contains a structural unit based on a (meth)acrylic compound containing a hydroxyalkyl group (C1). By containing a structural unit based on a (meth)acrylic compound containing a hydroxyalkyl group (C1), an acrylic moiety is introduced into the urethane acrylate, which can provide curability.

[0054] The hydroxyalkyl group can be, for example, an alkyl group having 1 to 20 carbon atoms and having at least one hydroxy group, and preferably has 2 to 10 carbon atoms.

[0055] The (C1) hydroxyalkyl group-containing (meth)acrylic compound can be, for example, a (meth)acrylic ester having a hydroxyalkyl group. The (C1) hydroxyalkyl group-containing (meth)acrylic compound can be, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, or 4-hydroxybutyl (meth)acrylate. In terms of improved adhesion to a polyethylene terephthalate substrate and improved excellent elongation properties at high temperatures, the (C1) hydroxyalkyl group-containing (meth)acrylic compound is preferably a methacrylic compound, and among these, hydroxyethyl methacrylate and hydroxypropyl methacrylate are particularly preferred.

[0056] Urethane Acrylate The urethane acrylate contained in the active energy ray curable resin composition of the present invention can be obtained by reacting an alicyclic isocyanate compound, an aromatic isocyanate compound, a polycarbonate diol, and a (meth)acrylic compound having a hydroxyalkyl group. This allows the urethane acrylate to have structural units derived from the alicyclic isocyanate compound, the aromatic isocyanate compound, the polycarbonate diol, and the (meth)acrylic compound having a hydroxyalkyl group.

[0057] It should be noted just for the sake of certainty that when a urethane acrylate contains a structural unit derived from a methacrylic compound having a hydroxyalkyl group, the urethane acrylate is strictly speaking a urethane methacrylate. Therefore, in the present invention, the urethane acrylate also includes a urethane methacrylate.

[0058] The urethane acrylate preferably contains 50% by mass or more of structural units based on the (B1) polycarbonate diol, which allows the active energy ray-curable resin composition of the present invention to easily form a film having high adhesion to a substrate and excellent elongation properties at high temperatures.

[0059] The urethane acrylate preferably contains structural units based on the (B1) polycarbonate diol in an amount of 60% by mass or more, more preferably 65% ​​by mass or more, and particularly preferably 70% by mass or more, and preferably contains 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less, and particularly preferably 80% by mass or less.

[0060] The urethane acrylate preferably contains 5 to 25 mass % of structural units based on the (A1) alicyclic isocyanate compound, which makes it easier for the active energy ray-curable resin composition of the present invention to form a film that is excellent in weather resistance and elongation properties at high temperatures.

[0061] The urethane acrylate preferably contains structural units based on the (A1) alicyclic isocyanate compound in an amount of 8 mass% or more, even more preferably 10 mass% or more, and more preferably 20 mass% or less, even more preferably 18 mass% or less, and particularly preferably 16 mass% or less.

[0062] From another viewpoint, the urethane acrylate preferably contains 5 to 40 parts by mass of the structural unit based on the alicyclic isocyanate compound (A1) per 100 parts by mass of the structural unit based on the polycarbonate diol (B1), which makes it easier for the active energy ray-curable resin composition of the present invention to form a film having excellent weather resistance and elongation properties at high temperatures.

[0063] The urethane acrylate preferably contains 6 parts by mass or more, even more preferably 8 parts by mass or more, and particularly preferably 10 parts by mass or more of the structural units based on the alicyclic isocyanate compound (A1) per 100 parts by mass of the structural units based on the polycarbonate diol (B1), and more preferably contains 35 parts by mass or less, even more preferably contains 33 parts by mass or less, and particularly preferably contains 30 parts by mass or less.

[0064] The urethane acrylate preferably contains 10 parts by mass or more of structural units based on the aromatic isocyanate compound (A2) relative to 100 parts by mass in total of the structural units based on the (A1) alicyclic isocyanate compound and the (A2) aromatic isocyanate compound, more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, and particularly preferably 25 parts by mass or more, and preferably contains 150 parts by mass or less, more preferably 120 parts by mass or less, even more preferably 100 parts by mass or less, and particularly preferably 80 parts by mass or less.

[0065] In the urethane acrylate, the total amount of structural units based on the (A1) alicyclic isocyanate compound and the (A2) aromatic isocyanate compound is preferably 10 parts by mass or more, more preferably 12 parts by mass or more, and even more preferably 14 parts by mass or more, and is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, even more preferably 50 parts by mass or less, and particularly preferably 40 parts by mass or less, relative to 100 parts by mass of structural units based on the (B1) polycarbonate diol.

[0066] The urethane acrylate preferably contains 1 to 10 mass % of structural units based on the (C1) hydroxyalkyl group-containing (meth)acrylic compound, more preferably 1.5 mass % or more, even more preferably 2 mass % or more, particularly preferably 2.5 mass % or more, more preferably 8 mass % or less, even more preferably 7 mass % or less, particularly preferably 6 mass % or less.

[0067] The urethane acrylate contained in the active energy ray curable resin composition of the present invention may contain structural units other than the structural units based on (A1) the alicyclic isocyanate compound, (A2) the aromatic isocyanate compound, (B1) the polycarbonate diol, and (C1) the hydroxyalkyl group-containing (meth)acrylic compound, as long as the effects of the present invention are not impaired. Alternatively, the urethane acrylate contained in the active energy ray curable resin composition of the present invention may be composed only of structural units based on (A1) the alicyclic isocyanate compound, (A2) the aromatic isocyanate compound, (B1) the polycarbonate diol, and (C1) the hydroxyalkyl group-containing (meth)acrylic compound. In the urethane acrylate contained in the active energy ray-curable resin composition of the present invention, the total amount of structural units based on (A1) the alicyclic isocyanate compound, (A2) the aromatic isocyanate compound, (B1) the polycarbonate diol, and (C1) the hydroxyalkyl group-containing (meth)acrylic compound is preferably 50 mass% or more, more preferably 80 mass% or more, even more preferably 90 mass% or more, and particularly preferably 95 mass% or more.

[0068] The urethane acrylate is formed as described above, and thus has a polymerizable portion (acrylic portion) in the molecule, for example, a compound having an acrylic ester portion. At least one polymerizable portion is contained in the urethane acrylate molecule, and preferably two or more polymerizable portions. This allows the urethane acrylate to have the property of being cured by irradiation with active energy rays.

[0069] The urethane acrylate may be any of a random polymer, a block polymer, and an alternating polymer.

[0070] The number average molecular weight of the urethane acrylate is, for example, preferably 800 or more, more preferably 2000 or more, even more preferably 5000 or more, and even more preferably 7000 or more, and is preferably 1000000 or less, more preferably 100000 or less, even more preferably 50000 or less, and particularly preferably 20000 or less.

[0071] The method for producing the urethane acrylate is not particularly limited, and for example, a known method for producing the urethane acrylate can be widely adopted. For example, the urethane acrylate can be produced by an addition reaction (polyaddition) using raw materials including (A1) an alicyclic isocyanate compound, (A2) an aromatic isocyanate compound, (B1) a polycarbonate diol, and (C1) a hydroxyalkyl group-containing (meth)acrylic compound.

[0072] In this case, a method can also be adopted in which an addition reaction (polyaddition) is first carried out using a compound other than the (C1) hydroxyalkyl group-containing (meth)acrylic compound, and when the isocyanate content in the reaction system reaches a predetermined numerical range, the (C1) hydroxyalkyl group-containing (meth)acrylic compound is added to the reaction system.

[0073] In the above addition reaction, a catalyst can be used as necessary. For example, an organic tin compound can be used as the catalyst, and specific examples include tin octoate, dibutyltin dilaurate, dioctyltin dineodecanoate, dioctyltin dilaurate, manganese, cobalt, lead, bismuth stannate, lead stannate, zirconium octoate, zinc octoate, dibutyltin-bis-o-phenylphenylene, dibutyltin-S,S-dibutyldithio-carbonate, triphenylantimony dichloride, dibutyltin maleate, dibutyltin diacetate, dibutyltin dilaurate mercaptide, triethylenediamine, bismuth stearate, lead stearate, and dimethyltin dichloride. The amount of the catalyst used can be adjusted within the range of 0.001 to 5 parts by mass relative to 100 parts by mass of the total amount of compound (A1), compound (A2), compound (B1), and compound (C1).

[0074] The above addition reaction can be carried out in the presence of a solvent, if necessary, and can also be carried out in the presence of a polymerization inhibitor such as hydroquinone monomethyl ether.

[0075] The temperature of the addition reaction is not particularly limited, and can be, for example, about 30 to 100° C., preferably 50 to 80° C. The reaction time is also not particularly limited, and can be set within an appropriate range depending on the reaction temperature. For example, the reaction can be continued until the amount of free isocyanate becomes 10% by mass or less, preferably 5% by mass or less, more preferably 0.1% by mass or less, based on the amount of the isocyanate compound used.

[0076] Active energy ray-curable resin composition The active energy ray-curable resin composition of the present invention may contain other components as long as it contains the urethane acrylate as an essential component. Examples of the other components include a polymerizable compound such as a vinyl monomer, a polymerization initiator, and a solvent.

[0077] As the polymerization initiator, for example, a wide variety of known polymerization initiators can be used. As the polymerization initiator, for example, one that initiates a polymerization reaction by irradiation with active energy rays is preferable, and an example of the polymerization initiator is a photopolymerization initiator.

[0078] Examples of photopolymerization initiators include aromatic ketones such as benzophenone, aromatic compounds such as anthracene and α-chloromethylnaphthalene, and sulfur compounds such as diphenyl sulfide and thiocarbamate. Examples of polymerization initiators using active energy rays such as ultraviolet rays other than visible light include acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, benzoin propyl ether, benzoin ethyl ether, benzyl dimethyl ketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1- Examples of the phenylpropan-1-one include thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 2,4,6,-trimethylbenzoyldiphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone).

[0079] The content of the polymerization initiator contained in the active energy ray-curable resin composition is not particularly limited, and can be 0.01 to 10 parts by mass, and preferably 0.03 to 5 parts by mass, based on 100 parts by mass of the urethane acrylate.

[0080] The solvent may be added, for example, for the purpose of improving the coating property of the active energy ray curable resin composition of the present invention. Examples of the solvent include chlorine-based hydrocarbons such as chloroform and 1,2-dichloroethane; ether compounds such as diethyl ether and tetrahydrofuran; aliphatic hydrocarbons such as hexane and heptane; alicyclic hydrocarbons such as cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; ketone compounds such as acetone and methyl ethyl ketone; ester compounds such as vinyl acetate; alcohols such as methanol, ethanol, isopropyl alcohol and t-butanol; formamides such as N,N-dimethylformamide and N,N-dimethylacetamide; pyrrolidones such as 2-pyrrolidone and N-methylpyrrolidone; dimethyl sulfoxide, etc.

[0081] The amount of the solvent contained in the active energy ray-curable resin composition of the present invention is not particularly limited. For example, the amount of the solvent can be adjusted so that the concentration of the urethane acrylate is 1 to 100 mass %, and in consideration of coatability, the amount is preferably about 5 to 50 mass %.

[0082] The active energy ray-curable resin composition of the present invention may also contain, as necessary, a polymerization inhibitor, a photosensitizer, a light stabilizer, a silane coupling agent, an ultraviolet absorber, a catalyst, a leveling agent, an antifoaming agent, a polymerization accelerator, an antioxidant, a flame retardant, an infrared absorber, an antistatic agent, a slip agent, a plasticizer, a dispersant, and the like.

[0083] The active energy ray-curable resin composition of the present invention preferably contains the urethane acrylate in an amount of 50 mass% or more, more preferably 80 mass% or more, even more preferably 90 mass% or more, and particularly preferably 95 mass% or more, based on the total mass excluding the solvent.

[0084] The method for preparing the active energy ray-curable resin composition of the present invention is not particularly limited. For example, the composition can be prepared by mixing a urethane acrylate with components that are added as necessary.

[0085] The active energy ray-curable resin composition of the present invention contains the urethane acrylate and has the property of being cured by active energy rays, so that it can form a cured product. As the active energy rays, ultraviolet rays are preferable, and other examples include electron beams, gamma rays, carbon arc lamps, xenon lamps, metal halide lamps, etc.

[0086] The method for curing the active energy ray curable resin composition of the present invention is not particularly limited, and for example, a wide variety of known methods can be adopted in the present invention. For example, a coating film of the active energy ray curable resin composition of the present invention is formed on a substrate, and the coating film is irradiated with active energy rays to form a cured product of the active energy ray curable resin composition.

[0087] A film can be formed using the active energy ray curable resin composition of the present invention. Since such a film contains a cured product of the active energy ray curable resin composition of the present invention, it has high adhesion to a substrate, excellent weather resistance, and excellent tensile elongation properties at high temperatures. Of course, a film formed using the active energy ray curable resin composition of the present invention has excellent tensile elongation properties even at low temperatures (e.g., room temperature).

[0088] Conventional protective films obtained from active energy ray-curable resin compositions have poor tensile elongation properties at high temperatures, and therefore even when the film is heated and laminated to a substrate having a curved or curved shape, the film has poor elongation and is difficult to laminate to the substrate. In contrast, the film obtained from the active energy ray-curable resin composition of the present invention has excellent tensile elongation properties at high temperatures and excellent adhesion to the substrate, and therefore has excellent adhesion to the substrate having a curved or curved shape.

[0089] Since the active energy ray-curable resin composition of the present invention has the above-mentioned properties, it can be applied to various films, and among them, it can be particularly suitably used for protective films.

[0090] The type of substrate to which the protective film is attached is not particularly limited, and examples thereof include various resin substrates. In terms of particularly excellent adhesion, the substrate is preferably an acrylic substrate, a polyethylene terephthalate substrate, or the like.

[0091] The thickness of the film formed from the active energy ray-curable resin composition of the present invention is not particularly limited, and may be within an appropriate range depending on the intended use, and may be the same as that of a conventional protective film, for example.

[0092] In specifying the invention included in the present disclosure, the configurations (properties, structures, functions, etc.) described in each embodiment of the present disclosure may be combined in any manner. In other words, the present disclosure includes all subject matter consisting of all combinations of the configurations that can be combined as described in this specification. EXAMPLES

[0093] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the embodiments of these examples.

[0094] (raw materials) Appropriate raw materials were selected from the raw materials shown below to prepare urethane acrylate, and an active energy ray-curable resin composition containing the urethane acrylate was prepared.

[0095] (A1) Alicyclic isocyanate compound Hydrogenated MDI: 4,4'-dicyclohexylmethane diisocyanate (Evonik "VESTANAT H12MDI") IPDI: Isophorone diisocyanate (Evonik "VESTANAT IPDI")

[0096] Other aliphatic isocyanate compounds ·HMDI: Hexamethylene diisocyanate

[0097] (A2) Aromatic isocyanate compounds ·TDI: 2,4-tolylene diisocyanate ·MDI: 4,4'-diphenylmethane diisocyanate

[0098] (B1) Polycarbonate diol UM-90(3 / 1): UBE "ETERNACOLL (registered trademark) UM-90(3 / 1)" UC-100: UBE's "ETERNACOLL (registered trademark) UC-100" UM-90(1 / 3): UBE "ETERNACOLL (registered trademark) UM-90(1 / 3)"

[0099] Other polycarbonate diols UH-100: UBE "ETERNACOLL (registered trademark) UH-100" (Polycarbonate diol not having an alicyclic structure or a heterocyclic ring)

[0100] (C1) Hydroxyalkyl group-containing (meth)acrylic compound ·HEMA: Hydroxyethyl methacrylate HPMA: Hydroxypropyl methacrylate ·HEA: Hydroxyethyl acrylate

[0101] Example 1 The raw materials shown in Example 1 of the recipe in Table 1 were selected to prepare an active energy ray curable resin composition containing urethane acrylate. Specifically, 75.68 parts by mass of (B1) polycarbonate diol (UM-90 (3 / 1)), 10.24 parts by mass of (A1) alicyclic isocyanate compound (hydrogenated MDI), 10.24 parts by mass of (A2) aromatic isocyanate compound (TDI), and 0.01 parts by mass of dioctyltin dilaurate as a catalyst were added to 50 parts by mass of methyl ethyl ketone, and reacted at 70 to 75°C for 120 minutes. This reaction produced a urethane prepolymer solution with a free isocyanate group content (solid content equivalent) of 1.50% by mass. To the obtained urethane prepolymer solution, 3.84 parts by mass of (C1) hydroxyalkyl group-containing (meth)acrylic compound (HEMA) was added, and the reaction was carried out at 70 to 75°C until the free isocyanate group content (solid content equivalent) became less than 0.1% by mass, thereby obtaining a urethane acrylate solution having a number average molecular weight (Mn) of 10,000. The obtained urethane acrylate solution was mixed with 3 parts by mass of "Omnirad 184" manufactured by IGM Resins BV as a photopolymerization initiator to obtain an active energy ray-curable resin composition.

[0102] (Examples 2 to 8) An active energy ray-curable resin composition was obtained in the same manner as in Example 1, except that the raw materials and the blending amounts shown in the recipe in Table 1 were selected.

[0103] (Examples 9 to 16) An active energy ray-curable resin composition was obtained in the same manner as in Example 1, except that the raw materials and their blending amounts shown in the recipe in Table 2 were selected.

[0104] (Comparative Examples 1 to 4) An active energy ray-curable resin composition was obtained in the same manner as in Example 1, except that the raw materials and their blending amounts shown in the recipe in Table 3 were selected.

[0105] (Evaluation method) The physical properties (adhesion to substrate, weather resistance, and tensile elongation properties) of the films formed using the active energy ray-curable resin compositions obtained in each of the Examples and Comparative Examples were evaluated by the following procedures.

[0106] [Film Preparation 1] The active energy ray-curable resin composition obtained in each Example and Comparative Example was applied to a 100 μm-thick PET (polyethylene terephthalate) substrate (Cosmoshine A4360, manufactured by Toyobo Co., Ltd.) so that the film thickness in a dry state was about 10 μm, and then dried in an oven at 80° C. for 1 minute to form a film on the PET film. Then, in a nitrogen atmosphere, a high-pressure mercury lamp (80 W / cm×1 lamp) was used to illuminate the film with an integrated illuminance of 600 mJ / cm. 2 The coating was cured by irradiating the coating with light at 400 nm to form a film. This resulted in a laminate in which a film was formed on a PET substrate.

[0107] [Film Creation 2] A laminate was obtained in which a film was formed on an acrylic substrate by following the same procedure as in Film Preparation 1, except that a 2 mm thick acrylic substrate ("Acrylic Test Piece" manufactured by Nippon Test Panel Co., Ltd.) was used instead of the PET substrate.

[0108] [Adhesion to PET substrate] For the film surface formed on the laminate surface obtained in Film Preparation 1, 100 2 mm x 2 mm grids were made by cutting the surface of the cured coating with a cutter knife, and cellophane adhesive tape was attached on top of them and then rapidly peeled off three times. The number of grids remaining without peeling was counted and the adhesion to the substrate (PET film) was evaluated according to the following criteria. ≪Judgment criteria≫ A: 100 grids remained, and the adhesion to the substrate was extremely excellent. B: The number of remaining grids was 80 or more and less than 100, and the adhesion to the substrate was excellent. C: The number of remaining grids was 60 or more and less than 80, and the adhesion to the substrate was good. D: The number of remaining cross-cut marks was less than 60, and the adhesion to the substrate was poor.

[0109] [Adhesion to acrylic substrates] For the film surface formed on the laminate surface obtained in Film Preparation 2, 100 2 mm x 2 mm grids were made by cutting the surface of the cured coating with a cutter knife, and cellophane adhesive tape was attached on top of them and then rapidly peeled off three times. The number of grids remaining without peeling off was counted and the adhesion to the substrate (acrylic film) was evaluated according to the following criteria. ≪Judgment criteria≫ A: 100 grids remained, and the adhesion to the substrate was extremely excellent. B: The number of remaining grids was 80 or more and less than 100, and the adhesion to the substrate was excellent. C: The number of remaining grids was 60 or more and less than 80, and the adhesion to the substrate was good. D: The number of remaining cross-cut marks was less than 60, and the adhesion to the substrate was poor.

[0110] [Weather resistance] The weather resistance of the film obtained in Film Preparation 1 was evaluated using a Sunshine Weather Meter S80 manufactured by Suga Test Instruments Co., Ltd. The test conditions were: light source: carbon arc lamp, irradiation time: 100 hours. The color difference ΔE*ab of the film before and after the test was measured using a color difference meter (SD6000 manufactured by Nippon Denshoku Industries Co., Ltd.) and evaluated based on the following criteria. The smaller the difference in color difference before and after the test, the higher the weather resistance of the film. ≪Judgment criteria≫ A: ΔE*ab value is less than 0.20 B: ΔE*ab value is 0.20 or more and less than 0.40 C: ΔE*ab value is 0.40 or more and less than 0.60 D: ΔE*ab value is 0.60 or more

[0111] [Tensile elongation (130℃)] The tensile elongation (%) at 130°C of the films obtained from the active energy ray curable resin compositions of each Example and Comparative Example was evaluated by a tensile test using a universal testing machine. Specifically, the active energy ray curable resin composition was applied to a release paper so that the thickness of the cured product was 100 μm, and cured by a UV irradiator to form a film. The obtained film was punched out with a dumbbell to prepare a test piece for the tensile test. A tensile test (tensile speed: 50 mm / min) was performed in an atmosphere of 130°C using an autograph (precision universal testing machine) made by Shimadzu Corporation, and the elongation (tensile elongation) at the time when the test piece broke was measured, and the evaluation was performed based on the following criteria. ≪Judgment criteria≫ A: The tensile elongation was 140% or more, and the tensile elongation properties were extremely excellent. B: The tensile elongation was 120% or more and less than 140%, and the tensile elongation characteristics were excellent. C: The tensile elongation was 100% or more and less than 120%, and the tensile elongation properties were good. D: Less than 100%, and the tensile elongation properties were poor.

[0112] [Tensile elongation (25℃)] The tensile elongation was measured in the same manner as in [Tensile elongation (130°C)], except that the tensile test was performed in an atmosphere of 25°C, and evaluated based on the following criteria. ≪Judgment criteria≫ A: The tensile elongation was 140% or more, and the tensile elongation properties were extremely excellent. B: The tensile elongation was 120% or more and less than 140%, and the tensile elongation characteristics were excellent. C: The tensile elongation was 100% or more and less than 120%, and the tensile elongation properties were good. D: Less than 100%, and the tensile elongation properties were poor.

[0113] Tables 1 to 3 show the compounding conditions and evaluation results of the active energy ray-curable resin compositions prepared in each of the Examples and Comparative Examples. In Tables 1 to 3, a blank space means that the corresponding raw material was not used, and "-" means that the evaluation was not performed.

[0114] The results in Tables 1 to 3 show that urethane acrylates containing all of the specified structural units have high adhesion to substrates, excellent weather resistance, and can form films with excellent tensile elongation properties at high temperatures.

[0115] [Table 1]

[0116] [Table 2]

[0117] [Table 3]

Claims

1. An active energy ray-curable resin composition containing a urethane acrylate, The urethane acrylate is Alicyclic isocyanate compounds, Aromatic isocyanate compounds, Polycarbonate diol, and (Meth)acrylic compounds having hydroxyalkyl groups having a structural unit derived from The polycarbonate diol is The following general formula (1) 【Chemistry 1】 (In formula (1), R represents a cycloalkane structure) is contained in an amount of 10 mol % or more, The urethane acrylate is Contains 50% by mass or more of structural units derived from the polycarbonate diol, The alicyclic isocyanate compound-derived structural unit is contained in an amount of 5 to 25% by mass, The composition contains 1 to 10% by mass of a structural unit derived from a (meth)acrylic compound having a hydroxyalkyl group, an active energy ray-curable resin composition comprising 10 parts by mass or more of a structural unit derived from the aromatic isocyanate compound per 100 parts by mass of the total amount of the structural units derived from the alicyclic isocyanate compound and the aromatic isocyanate compound;

2. The polycarbonate diol is The following general formula (2) 【Chemistry 2】 The active energy ray-curable resin composition according to claim 1 , comprising a structural unit represented by the following formula (2): (In formula (2), R 1 represents a chain alkylene group).

3. The active energy ray-curable resin composition according to claim 1 or 2, which is for use in a protective film.

4. A cured product of the active energy ray-curable resin composition according to claim 1 or 2.

5. A protective film comprising the cured product according to claim 4.

Images