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

Abstract

Provided are an active energy ray curable resin composition, a cured product thereof, and a protective film, which can form a film having high adhesion to a substrate, excellent weather resistance, and excellent tensile elongation characteristics in a high temperature state. **Solution**: The present invention is an active energy ray curable resin composition containing a urethane acrylate and a nitrogen-containing (meth)acrylic compound, wherein the urethane acrylate has a structural unit derived from an alicyclic isocyanate compound, a polycarbonate diol, and a (meth)acrylic compound having a hydroxyalkyl group, and the polycarbonate diol has an alicyclic structure or a heterocyclic ring.

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 Art

[0002] An active energy ray curable resin composition such as ultraviolet rays has the property of curing by irradiation with active energy rays, and thus, for example, a protective film used for protecting various substrates can be manufactured. In addition, the active energy ray curable resin composition is also applied to coating on 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 mainly composed of 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

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, the utilization value of active energy ray curable resin compositions as protective films for protecting various substrates has been increasing. For this reason, there is a demand for an active energy ray curable resin composition that can form a film having excellent adhesion to various substrates and excellent weather resistance.

[0006] In addition, since the surface of the substrate to be protected is not flat and may form a curved or spherical shape, it is necessary to bond the protective film to the substrate while stretching 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 in a high temperature state.

[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 in a high temperature state.

[0008] The present invention has been made in view of the above, and an object thereof is to provide an active energy ray curable resin composition, a cured product thereof, and a protective film, which can form a film having high adhesion to a substrate, excellent weather resistance, and excellent tensile elongation properties in a high temperature state.

Means for Solving the Problems

[0009] As a result of intensive studies to achieve the above object, the present inventor has found that the above object can be achieved by using a urethane acrylate having a specific structural unit as an essential component, and has completed the present invention.

[0010] That is, the present invention includes, for example, the subject matter described in the following items. Item 1 An active energy ray curable resin composition, comprising: a urethane acrylate and a nitrogen-containing (meth)acrylic compound, wherein the urethane acrylate: has a structural unit derived from an alicyclic isocyanate compound, a polycarbonate diol, and a (meth)acrylic compound having a hydroxyalkyl group, and the polycarbonate diol has an alicyclic structure or a heterocyclic ring, the active energy ray curable resin composition. Item 2 The polycarbonate diol-containing active energy ray-curable resin composition according to Item 1, wherein the polycarbonate diol has an alicyclic structure or a heterocyclic ring in the main chain. Item 3 The active energy ray-curable resin composition according to Item 1 or 2, wherein the nitrogen-containing (meth)acrylic compound has a -C(=O)-N- bond in the molecule. Item 4 The active energy ray-curable resin composition according to any one of Items 1 to 3, which is for a protective film. Item 5 A cured product of the active energy ray-curable resin composition according to any one of Items 1 to 4. Item 6 A protective film containing the cured product according to Item 5.

Advantages of the Invention

[0011] The active energy ray-curable resin composition of the present invention has high adhesion to a substrate, excellent weather resistance, and can form a film having excellent tensile elongation characteristics in a high-temperature state.

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described in detail. In this specification, the expressions "containing" and "comprising" include the concepts of "containing", "comprising", "substantially consisting of", and "consisting only of".

[0013] In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value of a numerical range at a certain step can be arbitrarily combined with the upper limit value or the lower limit value of a numerical range at another step. In the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples or a value uniquely derivable from the examples. Further, in this specification, the numerical values connected by "~" mean a numerical range including the numerical values before and after "~" as the lower limit value and the upper limit value.

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

[0015] In the present 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 a nitrogen-containing (meth)acrylic compound, thereby having high adhesion to a substrate, excellent weather resistance, and furthermore, being able to form a film having excellent tensile elongation characteristics in a high-temperature state. 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, 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 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”. Further, the nitrogen-containing (meth)acrylic compound is referred to as “(D1) nitrogen-containing (meth)acrylic compound”. Also, these compounds may be abbreviated as compound (A1), compound (B1), compound (C1), and compound (D1) in order.

[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] By containing a structural unit based on the (A1) alicyclic isocyanate compound, the active energy ray-curable resin composition of the present invention easily forms a film excellent in both weather resistance and elongation characteristics at high temperatures.

[0020] The alicyclic structure includes one or more saturated and / or unsaturated carbocyclic structures having no aromaticity. The carbocyclic structure may be two or more. The carbocyclic structure can have a branch of an aliphatic hydrocarbon structure. The carbocyclic structure is bonded to the hydrocarbon chain of the polymer main chain directly or via a hydrocarbon chain.

[0021] Examples of the carbocyclic structure include, as examples of monocyclic structures, cycloalkane structures such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, cyclododecane, and cycloalkene structures such as cyclopropene, cyclobutene, cyclopropene, cyclohexene, cycloheptene, cyclooctene. Also, as examples of bicyclic structures, bicyclic alkane structures such as bicycloundecane, and bicyclic alkene structures such as norbornene and norbornadiene can be mentioned and can be preferably used. Among them, it is preferable to have a carbocyclic structure having 4 to 8 carbon atoms, more preferably to have a monocyclic carbocyclic structure having 4 to 8 carbon atoms, still more preferably to have a carbocyclic structure of a monocyclic cycloalkane structure having 4 to 8 carbon atoms, and particularly preferably to have a cyclohexane structure.

[0022] Incidentally, the alicyclic structure may have a substituent. The "substituent" referred to in this specification includes, for example, 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, a cyano group, and the like.

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

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

[0025] (B1) Polycarbonate diol The urethane acrylate contains a structural unit based on (B1) polycarbonate diol. (B1) The polycarbonate diol is a diol compound having an alicyclic structure or a heterocyclic ring in the molecule.

[0026] By containing a structural unit based on (B1) polycarbonate diol, the urethane acrylate makes it easy to form a film in which the active energy ray-curable resin composition of the present invention has both excellent adhesion to the base material and excellent elongation characteristics at high temperatures.

[0027] (B1) In the polycarbonate diol, the alicyclic structure has the same meaning as the alicyclic structure in the (A1) alicyclic isocyanate compound. The alicyclic structure of the (B1) polycarbonate diol preferably has a carbocyclic structure having 4 to 8 carbon atoms, more preferably has a monocyclic carbocyclic structure having 4 to 8 carbon atoms, still more preferably has a carbocyclic structure of a monocyclic cycloalkane structure having 4 to 8 carbon atoms, and particularly preferably has a cyclohexane structure.

[0028] (B1) In the polycarbonate diol, the heterocyclic ring means, for example, a ring structure in which at least one (preferably one) of the carbon atoms forming the alicyclic structure is replaced by a hetero atom. Examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom, and the like.

[0029] (B1) The 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 has high adhesion to the substrate and easily forms a film having excellent elongation characteristics at high temperatures.

[0030] (B1) The polycarbonate diol more preferably has an alicyclic structure in the main chain, still more preferably has a carbocyclic 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.

[0031] (B1) Examples of the polycarbonate diol include diol compounds having a structural unit represented by the following formula (1).

[0032]

Chemical formula

[0033] In formula (1), R represents a divalent group based on the aforementioned alicyclic structure or heterocyclic ring. Therefore, examples of R include divalent groups based on a carbon ring structure of a monocyclic cycloalkane structure having 4 to 8 carbon atoms. Specific examples include a divalent group based on a cyclohexane structure, that is, a cyclohexylene group (-C6H 10 ) and it is particularly preferable to have this.

[0034] (B1) When the polycarbonate diol is a diol compound having a structural unit represented by the above formula (1), both ends are, for example, R-OH.

[0035] (B1) When the polycarbonate diol is a diol compound having a structural unit represented by the above formula (1), it can have other structural units in addition to the said structural unit. For example, (B1) the polycarbonate diol can include 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).

[0036]

Chemical formula

[0037] In formula (2), R 1 represents a chain-like alkylene group. The chain-like alkylene group is, for example, an alkylene group having 20 or fewer carbon atoms, preferably 16 or fewer, more preferably 12 or fewer, still more preferably 10 or fewer, and particularly preferably 8 or fewer. Also, the number of carbon atoms of the chain-like alkylene group is preferably 1 or more, more preferably 2 or more, still more preferably 3 or more. R 1 as the chain-like alkylene group may be linear or may have a branched chain. Specific examples of R 1 include -CH2-, -C2H4-, -C3H6-, -C4H8-, -C6H 12 -.

[0038] (B1) When the polycarbonate diol contains a diol compound having a structural unit represented by the formula (2) and such a structural unit is arranged at the terminal, the terminal of the structural unit represented by the formula (2) is, for example, R 1 -OH.

[0039] (B1) The polycarbonate diol may be a diol compound consisting only of 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).

[0040] (B1) When the 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, still more preferably 25 mol% or more, even more preferably 40 mol% or more, and particularly preferably 50 mol% or more with respect to 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 with respect to the total amount of the structural unit represented by the formula (1) and the structural unit represented by the formula (2).

[0041] (B1) When the 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), (B1) the polycarbonate diol 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).

[0042] (B1) When the 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), (B1) the polycarbonate diol may be a random polymer in which these structural units are randomly arranged, or may be a block polymer or an alternating polymer.

[0043] In addition, when (B1) the polycarbonate diol is a diol compound consisting only of the structural unit represented by the formula (1), it is also possible to separately contain a diol compound having the structural unit represented by the formula (2). That is, (B1) the polycarbonate diol may be a mixture.

[0044] (B1) The number average molecular weight of the polycarbonate diol is not particularly limited. For example, it is preferably 400 or more, more preferably 600 or more, still more preferably 800 or more, and preferably 100,000 or less, more preferably 10,000 or less, still more preferably 5,000 or less, and particularly preferably 2,000 or less.

[0045] In the present invention, the number average molecular weight can mean a value obtained by GPC measurement. Specifically, it is carried out by a GPC apparatus using tetrahydrofuran (THF) as a solvent and determined as a polystyrene equivalent value. The specific measurement conditions are as follows. Column: Tosoh Corporation's polystyrene gel column (TSKgel G4000HXL + TSKgel G3000HXL + TSKgel G2000HXL + 2 TSKgel G1000HXL connected in series in this order) Column temperature: 40 °C Detector: Differential refractive index detector (RID-6A manufactured by Shimadzu Corporation) Flow rate: 1 ml / min

[0046] In addition, when the (B1) polycarbonate diol is a commercially available product and its number average molecular weight is known from the manufacturer's guarantee value or the like, that value can be adopted as the number average molecular weight of the (B1) polycarbonate diol.

[0047] The production method of the (B1) polycarbonate diol is not particularly limited. For example, the (B1) polycarbonate diol can be produced by a known method for producing carbonate diol. In addition, the (B1) polycarbonate diol can also be obtained from commercially available products or the like. Examples of commercially available products of the (B1) polycarbonate diol include the "ETERNACOLL (registered trademark)" series of UBE Corporation. Specifically, "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)" can be mentioned.

[0048] (C1) (Meth)acrylic compound containing hydroxyalkyl group The urethane acrylate contains a structural unit based on the (C1) hydroxyalkyl group-containing (meth)acrylic compound. By containing a structural unit based on the (C1) hydroxyalkyl group-containing (meth)acrylic compound in the urethane acrylate, an acrylic moiety can be introduced into the urethane acrylate to impart curability.

[0049] Examples of the hydroxyalkyl group include alkyl groups having at least one hydroxy group and having 1 to 20 carbon atoms, preferably 2 to 10 carbon atoms.

[0050] (C1) The hydroxyalkyl group-containing (meth)acrylic compound can include, for example, (meth)acrylic esters having a hydroxyalkyl group. Examples of the (C1) hydroxyalkyl group-containing (meth)acrylic compound include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. In terms of further improving the adhesion to the polyethylene terephthalate substrate and being more likely to improve the excellent elongation properties at high temperatures, the (C1) hydroxyalkyl group-containing (meth)acrylic compound is preferably a methacrylic compound, and among them, hydroxyethyl methacrylate and hydroxypropyl methacrylate are particularly preferred.

[0051] 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, a polycarbonate diol, and a (meth)acrylic compound having a hydroxyalkyl group. Thereby, the urethane acrylate can have structural units derived from an alicyclic isocyanate compound, an aromatic isocyanate compound, a polycarbonate diol, and a (meth)acrylic compound having a hydroxyalkyl group.

[0052] Incidentally, although it is only for the sake of note, when the urethane acrylate contains a structural unit derived from a methacrylic compound having a hydroxyalkyl group, strictly speaking, the urethane acrylate is urethane methacrylate. Therefore, in the present invention, urethane acrylate also includes urethane methacrylate.

[0053] The urethane acrylate preferably contains, based on the total mass of the urethane acrylate and the total mass of the (D1) nitrogen-containing (meth)acrylic compound in the active energy ray-curable resin composition described below (hereinafter referred to as "total mass S"), 10% by mass or more of a structural unit based on (B1) polycarbonate diol. Thereby, the active energy ray-curable resin composition of the present invention has high adhesion to a substrate and easily forms a film excellent in elongation characteristics at high temperatures.

[0054] More preferably, the urethane acrylate contains 15% by mass or more, still more preferably 20% by mass or more, particularly preferably 25% by mass or more of a structural unit based on (B1) polycarbonate diol with respect to the total mass S, and preferably contains 80% by mass or less, more preferably 70% by mass or less, still more preferably 60% by mass or less, particularly preferably 50% by mass or less.

[0055] The urethane acrylate preferably contains 5 to 30% by mass of a structural unit based on (A1) an alicyclic isocyanate compound with respect to the total mass S. Thereby, the active energy ray-curable resin composition of the present invention easily forms a film excellent in weather resistance and elongation characteristics at high temperatures.

[0056] More preferably, the urethane acrylate contains 6% by mass or more, still more preferably 7% by mass or more, particularly preferably 8% by mass or more of a structural unit based on (A1) an alicyclic isocyanate compound with respect to the total mass S, and more preferably contains 25% by mass or less, still more preferably 20% by mass or less, even more preferably 18% by mass or less, particularly preferably 16% by mass or less.

[0057] From another perspective, it is preferable that the urethane acrylate contains 5 to 60 parts by mass of a structural unit based on an alicyclic isocyanate compound (A1) with respect to 100 parts by mass of a structural unit based on a polycarbonate diol (B1). Thereby, the active energy ray-curable resin composition of the present invention is likely to form a film excellent in weather resistance and elongation characteristics at high temperatures.

[0058] More preferably, the urethane acrylate contains 10 parts by mass or more of a structural unit based on an alicyclic isocyanate compound (A1) with respect to 100 parts by mass of a structural unit based on a polycarbonate diol (B1), even more preferably 15 parts by mass or more, particularly preferably 20 parts by mass or more. Also, more preferably, it contains 55 parts by mass or less, even more preferably 50 parts by mass or less, particularly preferably 45 parts by mass or less.

[0059] Preferably, the urethane acrylate contains 0.2 to 10% by mass of a structural unit based on a hydroxyalkyl group-containing (meth)acrylic compound (C1) with respect to the total mass S. More preferably, the urethane acrylate contains 0.3% by mass or more of a structural unit based on a hydroxyalkyl group-containing (meth)acrylic compound (C1) with respect to the total mass S, even more preferably 0.4% by mass or more, particularly preferably 0.5% by mass or more. Also, more preferably, it contains 8% by mass or less, even more preferably 7% by mass or less, even more preferably 6% by mass or less, particularly preferably 5% by mass or less.

[0060] The urethane acrylate is formed as described above and has a polymerizable site (acrylic site) in the molecule, and is, for example, a compound having an acrylic ester site. The polymerizable site is contained at least one or more in the urethane acrylate molecule, preferably two or more. Thereby, the urethane acrylate can have the property of curing by irradiation with active energy rays.

[0061] The urethane acrylate contained in the active energy ray-curable resin composition of the present invention can contain structural units other than those based on (A1) an alicyclic isocyanate compound, (B1) a polycarbonate diol, and (C1) a hydroxyalkyl group-containing (meth)acrylic compound, as long as the effects of the present invention are not inhibited. For example, the urethane acrylate can contain structural units based on an aromatic isocyanate compound. Specific examples of the aromatic isocyanate compound include 2,4-tolylene diisocyanate (alias tolylene-2,4-diisocyanate), 2,6-tolylene diisocyanate (alias 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, 1,4-phenylene diisocyanate, and the like.

[0062] Alternatively, the urethane acrylate contained in the active energy ray-curable resin composition of the present invention may consist only of structural units based on (A1) an alicyclic isocyanate compound, (B1) a polycarbonate diol, and (C1) a hydroxyalkyl group-containing (meth)acrylic compound. It is preferable that the total amount of the structural units based on (A1) an alicyclic isocyanate compound, (B1) a polycarbonate diol, and (C1) a hydroxyalkyl group-containing (meth)acrylic compound in the urethane acrylate contained in the active energy ray-curable resin composition of the present invention is 50% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0063] The urethane acrylate may be any of a random polymer, a block polymer, and an alternating polymer.

[0064] The number average molecular weight of the urethane acrylate is preferably, for example, 800 or more, more preferably 2000 or more, still more preferably 5000 or more, still more preferably 7000 or more, and preferably 1000000 or less, more preferably 100000 or less, still more preferably 50000 or less, and particularly preferably 20000 or less.

[0065] The production method of the urethane acrylate is not particularly limited, and for example, a known production method of urethane acrylate can be widely adopted. For example, urethane acrylate can be produced by an addition reaction (polyaddition) using a raw material containing (A1) an alicyclic isocyanate compound, (B1) a polycarbonate diol, and (C1) a hydroxyalkyl group-containing (meth)acrylic compound.

[0066] In this case, it is also possible to adopt a method in which an addition reaction (polyaddition) using a compound other than (C1) the hydroxyalkyl group-containing (meth)acrylic compound is first carried out, and the (C1) hydroxyalkyl group-containing (meth)acrylic compound is added to the reaction system when the isocyanate content in the reaction system reaches a predetermined numerical range.

[0067] In the above addition reaction, a catalyst can be used as necessary. As the catalyst, for example, an organotin compound can be used. 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, dimethyltin dichloride, and the like. The amount of the catalyst used can be adjusted in the range of 0.001 to 5 parts by mass with respect to 100 parts by mass of the total amount of the compound (A1), the compound (B1), and the compound (C1).

[0068] In addition to the above addition reaction, a solvent can be used as necessary, and the reaction can also be carried out in the presence of a polymerization inhibitor such as hydroquinone monomethyl ether.

[0069] The temperature of the above addition reaction is not particularly limited. For example, it can be about 30 to 100 °C, preferably 50 to 80 °C. The reaction time is not particularly limited either and can be appropriately adjusted according to the reaction temperature. For example, the reaction can be carried out until the amount of free isocyanate is 10% by mass or less, preferably 5% by mass or less, more preferably 0.1% by mass or less, based on the isocyanate compound used.

[0070] Actinic energy ray curable resin composition The active energy ray-curable resin composition of the present invention contains the urethane acrylate and (D1) a nitrogen-containing (meth)acrylic compound as essential components.

[0071] (D1) The nitrogen-containing (meth)acrylic compound is a (meth)acrylic compound containing a nitrogen atom in the molecule and exhibiting polymerizability, particularly radical polymerizability.

[0072] (D1) The nitrogen-containing (meth)acrylic compound can be a compound having a -C(=O)-N- moiety (-C(=O)-N- bond) in the molecule. Examples of such (D1) nitrogen-containing (meth)acrylic compounds include (meth)acrylamide or (meth)acrylamide derivatives.

[0073] Examples of the (meth)acrylamide derivative include, for example, a compound represented by the following general formula (3).

[0074] [Chemical formula]

[0075] In formula (3), Ra is a hydrogen atom or a methyl group, R 3 represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and R 4 represents a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent. R 3 and R 4 may be bonded to each other via a heteroatom or without a heteroatom together with the nitrogen atom to which they are bonded to form a saturated ring.

[0076] R 3 When is a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, examples of the hydrocarbon group include an alkyl group. The number of carbon atoms of the alkyl group is preferably 8 or less, more preferably 6 or less, and still more preferably 4 or less. The alkyl group may have a linear structure, a branched structure, or a cyclic structure. The alkyl group may also have a substituent such as a hydroxyl group.

[0077] In the compound represented by formula (3), when R 3 and R 4 are bonded to each other via a heteroatom together with the nitrogen atom to which they are bonded to form a saturated ring, examples of the heteroatom include a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom, etc., and an oxygen atom is preferred. Examples of the compound represented by such formula (3) include N-acryloylmorpholine.

[0078] Examples of the compound represented by the formula (3) include N-acryloylmorpholine, N-alkyl-substituted (meth)acrylamides, that is, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, and the like.

[0079] (D1) The nitrogen-containing (meth)acrylic compound preferably has a cyclic moiety in the molecule, and in this case, it is more preferable that the cyclic moiety has an oxygen atom. In this case, the active energy ray-curable resin composition can form a film having particularly high adhesion to the substrate, particularly excellent weather resistance, and particularly excellent tensile elongation properties in a high-temperature state.

[0080] From this viewpoint, N-acryloylmorpholine is particularly preferable as the (D1) nitrogen-containing (meth)acrylic compound.

[0081] In the active energy ray-curable resin composition of the present invention, the content ratio of the (D1) nitrogen-containing (meth)acrylic compound is not particularly limited. For example, it is preferably 20% by mass or more, more preferably 25% by mass or more, further preferably 30% by mass or more, particularly preferably 35% by mass or more, and preferably 90% by mass or less, more preferably 85% by mass or less, further preferably 80% by mass or less, even more preferably 75% by mass or less, and particularly preferably 70% by mass or less with respect to the total mass S (total mass of the urethane acrylate and the (D1) nitrogen-containing (meth)acrylic compound).

[0082] The active energy ray-curable resin composition of the present invention can contain one or more of the above urethane acrylates. Further, the active energy ray-curable resin composition of the present invention can contain one or more of the (D1) nitrogen-containing (meth)acrylic compounds.

[0083] As long as the active energy ray-curable resin composition of the present invention contains the urethane acrylate and the (D1) nitrogen-containing (meth)acrylic compound as essential components, other components can be included. Examples of the other components include polymerizable compounds such as vinyl monomers, polymerization initiators, solvents, and the like.

[0084] As the polymerization initiator, for example, known polymerization initiators can be widely used. The polymerization initiator is preferably one that initiates a polymerization reaction by irradiation with active energy rays, and examples thereof include photopolymerization initiators.

[0085] Examples of the photoinitiator 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 the polymerization initiator for 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-diphenylethane-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-phenylpropan-1-one, thioxanthone, diethyl thioxanthone, 2-isopropyl thioxanthone, 2-chloro thioxanthone, 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, oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), and the like.

[0086] 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, preferably 0.03 to 5 parts by mass, based on 100 parts by mass of the urethane acrylate.

[0087] The solvent can be added, for example, for the purpose of improving the coatability of the active energy ray curable resin composition of the present invention. Examples of the solvent include chlorinated 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; and dimethyl sulfoxide and the like.

[0088] 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% by mass. Considering the coatability, it is preferably about 5 to 50% by mass.

[0089] The active energy ray curable resin composition of the present invention can optionally contain 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.

[0090] In the active energy ray curable resin composition of the present invention, the total amount of the urethane acrylate and the nitrogen-containing (meth)acrylic compound (D1) is preferably 50% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more, based on the total mass excluding the solvent.

[0091] The method for preparing the active energy ray curable resin composition of the present invention is not particularly limited. For example, it can be prepared by mixing urethane acrylate, the nitrogen-containing (meth)acrylic compound (D1), and components added as necessary.

[0092] The active energy ray-curable resin composition of the present invention contains the urethane acrylate and (D1) a nitrogen-containing (meth)acrylic compound, and has the property of curing by active energy rays, so a cured product can be formed. As the active energy rays, ultraviolet rays are preferable, and in addition, electron beams, γ-rays, carbon arc lamps, xenon lamps, metal halide lamps, etc. can be mentioned.

[0093] The method for curing the active energy ray-curable resin composition of the present invention is not particularly limited. For example, known methods can be widely 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 by irradiating such a coating film with active energy rays, a cured product of the active energy ray-curable resin composition can be formed.

[0094] 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 the substrate, excellent weather resistance, and moreover, excellent tensile elongation characteristics in a high-temperature state.

[0095] The protective film obtained from the conventional active energy ray-curable resin composition did not have good tensile elongation characteristics at high temperatures. Therefore, even when trying to bond it to a substrate having a curved or curved surface shape while heating, the film had poor elongation and it was difficult to bond it to the substrate. On the other hand, the film obtained from the active energy ray-curable resin composition of the present invention has excellent tensile elongation characteristics at high temperatures and excellent adhesion to the substrate, so it also has excellent adhesion to a substrate having a curved or curved surface shape.

[0096] Since the active energy ray-curable resin composition of the present invention has the above characteristics, it can be applied to various films, and among them, it can be particularly preferably used for protective films.

[0097] The type of the base material to which the protective film is to be laminated is not particularly limited, and for example, various resin base materials can be mentioned. In terms of particularly excellent adhesiveness, the base material is preferably an acrylic base material, a polyethylene terephthalate base material, or the like.

[0098] The thickness of the film formed from the active energy ray curable resin composition of the present invention is also not particularly limited. It can be set to an appropriate range according to the intended use, and for example, it can be the same as that of a conventional protective film.

[0099] In identifying the inventions included in the present disclosure, each configuration (properties, structure, function, etc.) described in each embodiment of the present disclosure may be combined in any manner. That is, the present disclosure includes all the themes consisting of any combinations of the combinable configurations described in this specification.

Examples

[0100] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the aspects of these examples.

[0101] (Raw materials) Appropriate raw materials were selected from the raw materials shown below to prepare urethane acrylate.

[0102] (A1) Alicyclic isocyanate compound · Hydrogenated MDI: 4,4'-dicyclohexylmethane diisocyanate (Evonik's "VESTANAT H12MDI") · IPDI: Isophorone diisocyanate (Evonik's "VESTANAT IPDI")

[0103] Other isocyanate compounds · MDI: 4,4'-diphenylmethane diisocyanate

[0104] (B1) Polycarbonate diol · UM-90(3 / 1): UBE's "ETERNACOLL (registered trademark) UM-90(3 / 1)" ·UC-100: "ETERNACOLL (registered trademark) UC-100" manufactured by UBE ·UM-90(1 / 3): "ETERNACOLL (registered trademark) UM-90(1 / 3)" manufactured by UBE

[0105] Other polycarbonate diols ·UH-100: "ETERNACOLL (registered trademark) UH-100" manufactured by UBE (Polycarbonate diol having no alicyclic structure or heterocyclic ring)

[0106] (C1) (Meth)acrylic compound containing hydroxyalkyl group ·HEMA: Hydroxyethyl methacrylate ·HPMA: Hydroxypropyl methacrylate ·HEA: Hydroxyethyl acrylate

[0107] Also, appropriate raw materials were selected from the following raw materials to prepare an active energy ray curable resin composition.

[0108] (D1) Nitrogen-containing (meth)acrylic compound ·ACMO: N - acryloylmorpholine ·DMAA: N,N - dimethylacrylamide

[0109] Other monomers ·IBXA: Isobornyl acrylate

[0110] (Example 1) The raw materials shown in Example 1 of the formulation table in Table 1 were selected to prepare an active energy ray-curable resin composition containing urethane acrylate. Specifically, in 50 parts by mass of methyl ethyl ketone, 35.80 parts by mass of (B1) polycarbonate diol (UM-90(3 / 1)), 12.22 parts by mass of (A1) alicyclic isocyanate compound (hydrogenated MDI), and 0.01 part by mass of dioctyltin dilaurate as a catalyst were added, and the mixture was reacted at 70 to 75 °C for 120 minutes. By this reaction, a urethane prepolymer solution having a free isocyanate group content (in terms of solid content) of 1.50% by mass was obtained. To the obtained urethane prepolymer solution, 1.98 parts by mass of (C1) hydroxyalkyl group-containing (meth)acrylic compound (HEMA) was added, and then the reaction was carried out at 70 to 75 °C until the free isocyanate group content (in terms of solid content) became less than 0.1% by mass, and a solution of urethane acrylate having a number average molecular weight (Mn) of 10,000 was obtained. To the obtained solution of urethane acrylate, 50 parts by mass of (D1) nitrogen-containing (meth)acrylic compound (ACMO) and 3 parts by mass of "Omnirad 184" manufactured by IGM Resins B.V. as a photopolymerization initiator were mixed to obtain an active energy ray-curable resin composition.

[0111] (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 compounding amounts shown in the formulation table of Table 1 were selected.

[0112] (Examples 9 to 15) An active energy ray-curable resin composition was obtained in the same manner as in Example 1, except that the raw materials and compounding amounts shown in the formulation table of Table 2 were selected.

[0113] (Comparative Examples 1 to 3) An active energy ray-curable resin composition was obtained in the same manner as in Example 1, except that the raw materials and compounding amounts shown in the formulation table of Table 3 were selected.

[0114] (Evaluation Method) The physical properties (adhesion to the 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 according to the following procedure.

[0115] [Fabrication of Film 1] The active energy ray-curable resin compositions obtained in each of the examples and comparative examples were applied to a PET (polyethylene terephthalate) substrate (「Cosmo Shine A4360」manufactured by Toyobo Co., Ltd.) with a thickness of 100 μm so that the film thickness in the dried 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. Thereafter, in a nitrogen atmosphere, a high-pressure mercury lamp (80 W / cm × 1 lamp) was irradiated onto the film at an integrated illuminance of 600 mJ / cm 2 to cure the film and form a film. Thus, a laminate in which a film was formed on a PET substrate was obtained.

[0116] [Fabrication of Film 2] A laminate in which a film was formed on an acrylic substrate was obtained in the same procedure as in Fabrication of Film 1, except that an acrylic substrate (「Acrylic Test Piece」manufactured by Nippon Test Panel Co., Ltd.) with a thickness of 2 mm was used instead of the PET substrate.

[0117] [Adhesion to PET Substrate] With respect to the film surface formed on the surface of the laminate obtained in Fabrication of Film 1, cuts were made on the surface of the cured coating film with a cutter knife to prepare 100 squares of 2 mm × 2 mm, and after sticking a cellophane adhesive tape thereon, the operation of rapidly peeling it off was performed 3 times, and the number of squares remaining without peeling was counted, and the adhesion to the substrate (PET film) was evaluated according to the following criteria. ≪Judgment Criteria≫ A: The number of remaining squares was 100, and the adhesion to the substrate was extremely excellent. B: The number of remaining squares was 80 or more and less than 100, and the adhesion to the substrate was excellent. C: The number of remaining squares was 60 or more and less than 80, and the adhesion to the substrate was good. D: The number of remaining squares was less than 60, and the adhesion to the base material was poor.

[0118] [Adhesion to acrylic base material] For the film surface formed on the surface of the laminate obtained in Film Preparation 2, a cut was made with a cutter knife on the surface of the cured coating film to prepare 100 squares of 2 mm × 2 mm. After sticking a cellophane adhesive tape on it, the operation of quickly peeling it off was performed 3 times, and the number of remaining squares that did not peel off was counted, and the adhesion to the base material (acrylic film) was evaluated according to the following criteria. ≪Judgment criteria≫ A: The number of remaining squares was 100, and the adhesion to the base material was extremely excellent. B: The number of remaining squares was 80 or more and less than 100, and the adhesion to the base material was excellent. C: The number of remaining squares was 60 or more and less than 80, and the adhesion to the base material was good. D: The number of remaining squares was less than 60, and the adhesion to the base material was poor.

[0119] [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 a light source: carbon arc lamp and an 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 the evaluation was based on the following judgment criteria. The smaller the difference in color difference before and after the test, the higher the weather resistance of the film. ≪Judgment criteria≫ A: The ΔE*ab value is less than 0.10 B: The ΔE*ab value is 0.10 or more and less than 0.30 C: The ΔE*ab value is 0.30 or more and less than 0.50 D: The ΔE*ab value is 0.50 or more

[0120] [Tensile elongation (130 °C)] 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 became 100 μm, cured with a UV irradiator, and a film was formed. 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 at 130°C in an atmosphere using an autograph (precision universal testing machine) manufactured by Shimadzu Corporation, and the elongation (tensile elongation) at the time when the test piece broke was measured and evaluated based on the following criteria. <<Judgment Criteria>> A: The tensile elongation was 120% or more, and the tensile elongation characteristics were extremely excellent. B: The tensile elongation was 100% or more and less than 120%, and the tensile elongation characteristics were excellent. C: The tensile elongation was 80% or more and less than 100%, and the tensile elongation characteristics were good. D: The tensile elongation was less than 80%, and the tensile elongation characteristics were inferior.

[0121] [Tensile Elongation (25°C)] The tensile elongation was measured in the same procedure as [Tensile Elongation (130°C)] except that the tensile test was performed in an atmosphere at 25°C, and the evaluation was made based on the following criteria. <<Judgment Criteria>> A: The tensile elongation was 120% or more, and the tensile elongation characteristics were extremely excellent. B: The tensile elongation was 100% or more and less than 120%, and the tensile elongation characteristics were excellent. C: The tensile elongation was 80% or more and less than 100%, and the tensile elongation characteristics were good. D: The tensile elongation was less than 80%, and the tensile elongation characteristics were inferior.

[0122] Tables 1 to 3 show the compounding conditions and evaluation results of the active energy ray-curable resin compositions prepared in each example and comparative example. In Tables 1 to 3, a blank means that the raw material was not used.

[0123] From the results in Tables 1 to 3, it was found that an active energy ray-curable resin composition containing a urethane acrylate containing all predetermined structural units and a nitrogen-containing (meth)acrylic compound (D1) has high adhesion to a substrate, excellent weather resistance, and moreover, can form a film having excellent tensile elongation characteristics in a high-temperature state. Although not shown in Table 1, the film prepared from the active energy ray-curable resin composition obtained in Example 1 had a tensile elongation of about 6% at room temperature (25°C). Therefore, it can be said that the film prepared from the active energy ray-curable resin composition obtained in Example 1 is a material in which the tensile elongation characteristics at a high-temperature state (130°C) are significantly improved compared to room temperature.

[0124]

Table 1

[0125]

Table 2

[0126]

Table 3

Claims

1. An active energy ray-curable resin composition, Contains a urethane acrylate and a nitrogen-containing (meth)acrylic compound, The urethane acrylate is Alicyclic isocyanate compounds, Polycarbonate diol, and having a structural unit derived from a (meth)acrylic compound having a hydroxyalkyl group, The alicyclic isocyanate compound contains 4,4'-dicyclohexylmethane diisocyanate, The polycarbonate diol has an alicyclic structure or a heterocyclic structure.

2. The active energy ray-curable resin composition according to claim 1 , wherein the polycarbonate diol has an alicyclic structure or a heterocyclic ring in a main chain.

3. 2. The active energy ray-curable resin composition according to claim 1, wherein the nitrogen-containing (meth)acrylic compound has a -C(=O)-N- bond in the molecule.

4. The active energy ray-curable resin composition according to any one of claims 1 to 3, which is for use in a protective film.

5. A cured product of the active energy ray-curable resin composition according to any one of claims 1 to 3.

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

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