Curable resin composition and coating film

Abstract

The present invention provides a curable resin composition and a coating film obtained from the curable resin composition that exhibit excellent scratch resistance and excellent adhesion to the substrate even in a humid and hot environment, and that also has low viscosity and excellent handling properties. [Solution] The curable resin composition contains a polymerizable component and a carbodiimide compound (L), wherein the polymerizable component contains a compound (A) having 3 to 5 (meth)acryloyl groups and a nitrogen-containing polymerizable compound (B), and the nitrogen-containing polymerizable compound (B) is of formula (1) TIFF0007934061000008.tif47170 (In formula (1), R 1 R represents a hydrogen atom or a methyl group. 2 and R 3 R independently represents a hydrocarbon group which may have substituents and / or heteroatoms, 2 and R 3 This refers to a compound that may be represented as (which may form a cyclic structure by bonding with nitrogen atoms).

Description

[Technical Field]

[0001] The present invention relates to a curable resin composition and a coating film obtained from the curable resin composition. [Background technology]

[0002] Curable resin compositions, which harden when exposed to active energy rays such as ultraviolet light, are widely used in applications such as protective films, adhesives, and various coatings for protecting various substrates, and are highly valuable functional materials. One application of such curable resin compositions is in film coatings. By applying such a film coating composition as a coating to the surface of a film such as a substrate and curing it, a coating film (cured product) can be formed on the film surface. This makes it possible to functionalize the film surface.

[0003] Patent Document 1 discloses preparing an active energy ray curable coating agent composition comprising two or more specific (meth)acryloyl group-containing compounds as a curable resin, and adjusting the mechanical properties of a film by forming a cured product of such composition on the film surface. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2015 / 133560 [Overview of the project] [Problems that the invention aims to solve]

[0005] In the applications such as film coatings as described above, it is required to further improve the mechanical properties (for example, scratch resistance) of the cured product (coating film) of the curable resin composition, and in addition, excellent handleability when applying the curable resin composition is also required. Moreover, in film coating applications, the film may be exposed to a moist heat environment (also referred to as a high-temperature high-humidity environment), so a curable resin composition that can exhibit high adhesion to a substrate even in a moist heat environment is also demanded.

[0006] Even if a cured product obtained from a conventional curable composition can be expected to have a certain improvement in mechanical properties, it has a problem that the adhesion to a substrate in a moist heat resistant environment decreases, and these two properties are in a so-called trade-off relationship, making it difficult to achieve both. From this perspective, there is a demand for a curable resin composition that is capable of forming a cured product having excellent mechanical properties and excellent adhesion to a substrate in a moist heat resistant environment.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a curable resin composition that can form a cured product having excellent scratch resistance and also excellent adhesion to a substrate even in a moist heat environment, and that has low viscosity and excellent handleability, as well as a coating film obtained from the curable resin composition. [Means for Solving the Problems]

[0008] As a result of extensive and intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by combining a polyfunctional compound having a specific structure, a nitrogen-containing polymerizable compound, and a carbodiimide compound, and have completed the present invention.

[0009] That is, the present invention includes, for example, the subject matters described in the following items.

[0010] Item 1 A curable resin composition, comprising at least a polymerizable component and a carbodiimide compound (L), wherein the polymerizable component is A compound (A) having 3 to 5 (meth)acryloyl groups and a nitrogen-containing polymerizable compound (B) are included in at least one of these compounds. The nitrogen-containing polymerizable compound (B) is given by the following formula (1)

[0011] [ka] (In formula (1), R 1 R represents a hydrogen atom or a methyl group. 2 and R 3 R represents a hydrocarbon group which may have substituents and / or heteroatoms, either identical or different, 2 and R 3 (These may be bonded together with the nitrogen atom to which they are attached, either via heteroatoms or without, to form a cyclic structure.) A curable resin composition, which is a compound represented by [the formula shown].

[0012] Section 2 The polymerizable component further contains compound (C), The compound (C) is a compound having at least two pentaerythritol skeletons and at least three (meth)acryloyl groups, The curable resin composition according to item 1, wherein compound (A) is a compound other than compound (C).

[0013] Section 3 The curable resin composition according to claim 1 or 2, wherein the carbodiimide compound (L) is contained in an amount of 0.1 parts by mass or more and 5 parts by mass or less based on 100 parts by mass of the total mass of the polymerizable component and the carbodiimide compound (L).

[0014] Section 4 A curable resin composition according to any one of claims 1 to 3, comprising 75% by mass or more of the polymerizable component and the carbodiimide compound (L).

[0015] Section 5 The curable resin composition according to any one of claims 1 to 4, wherein the compound (C) is a compound having five or more (meth)acryloyl groups.

[0016] Section 6 The curable resin composition according to any one of claims 1 to 5, wherein the compound (C) is a compound having a dipentaerythritol skeleton.

[0017] Section 7 A curable resin composition according to any one of claims 1 to 6, comprising a photoinitiator.

[0018] Section 8 A curable resin composition for use as a paint, as described in any one of items 1 to 7.

[0019] Section 9 A coating film containing a cured product of a curable resin composition described in any one of items 1 to 8. [Effects of the Invention]

[0020] The curable resin composition of the present invention can form a cured product that has excellent scratch resistance and excellent adhesion to the substrate even in a humid and hot environment. Furthermore, because the curable resin composition of the present invention has low viscosity, it also has excellent handling properties. [Modes for carrying out the invention]

[0021] Embodiments of the present invention will be described in detail below. In this specification, the expressions "containing" and "including" include the concepts of "containing," "including," "substantially consisting of," and "consisting only of."

[0022] In the numerical ranges described stepwise in this specification, the upper or lower limit of a numerical range in one step can be arbitrarily combined with the upper or lower limit of a numerical range in another step. In the numerical ranges described in this specification, the upper or lower limit of a numerical range may be replaced with values ​​shown in the examples or values ​​that can be uniquely derived from the examples. Furthermore, in this specification, numbers connected by "~" mean a numerical range that includes the numbers before and after "~" as the lower and upper limits.

[0023] The curable resin composition of the present invention contains a polymerizable component and a carbodiimide compound (L) as essential components. The polymerizable component is at least containing a compound (A) having 3 to 5 (meth)acryloyl groups and a nitrogen-containing polymerizable compound (B).

[0024] The nitrogen-containing polymerizable compound (B) is a compound represented by the following formula (1).

[0025] [Chemical Formula]

[0026] Here, in the formula (1), R 1 represents a hydrogen atom or a methyl group, and R 2 and R 3 are the same or different and each represents a hydrocarbon group which may have a substituent and / or a heteroatom. R 2 and R 3 may be bonded to each other together with the nitrogen atom to which they are bonded, via or not via a heteroatom, to form a cyclic structure.

[0027] By containing the compound (A), the nitrogen-containing polymerizable compound (B) and the carbodiimide compound (L), the curable resin composition of the present invention can form a cured product having excellent scratch resistance.

[0028] Further, by containing the compound (A), the nitrogen-containing polymerizable compound (B) and the carbodiimide compound (L), the curable resin composition of the present invention can form a cured product having excellent adhesion to a substrate even in a moist heat environment, and in particular, can form a cured product having excellent adhesion to a substrate even after being exposed to a moist heat environment for a long time. The excellent adhesion in a moist heat environment can be judged, for example, by the measurement of "Adhesion (in moist heat environment)" described in the Examples. Examples of the moist heat environment include an environment at a temperature of 60°C and a humidity of 95%.

[0029] Furthermore, the curable resin composition of the present invention has low viscosity, resulting in excellent handling properties.

[0030] The polymerizable components and carbodiimide compound (L) contained in the curable resin composition of the present invention will be described in detail below.

[0031] (polymerizable components) Compound (A) The polymerizable component contained in the curable resin composition of the present invention includes compound (A) as an essential component. Compound (A) is a compound having 3 to 5 (3 or more, 5 or less) (meth)acryloyl groups. Compound (A) exhibits, for example, radical polymerizability.

[0032] In this specification, (meth)acryloyl group means either an acryloyl group or a methacryloyl group.

[0033] The inclusion of compound (A) as a polymerizable component results in cured products formed from the curable resin composition of the present invention exhibiting excellent adhesion to the substrate, and in particular, improved adhesion to the substrate even under humid and hot conditions.

[0034] If compound (A) contains fewer than three (meth)acryloyl groups, the cured product formed from the curable resin composition may have reduced adhesion to the substrate in a humid and hot environment. If compound (A) contains six or more (meth)acryloyl groups, the curable resin composition of the present invention is prone to increased viscosity, resulting in reduced handling properties, and the cured product formed from the curable resin composition of the present invention will have difficulty adhering to the substrate. Compound (A) preferably has three or four (meth)acryloyl groups in its molecule, and is particularly preferably four (meth)acryloyl groups.

[0035] The structure of compound (A) is not particularly limited, as long as it has three to five (meth)acryloyl groups. However, compound (A) is a compound other than compound (C) described below.

[0036] Specific examples of compound (A) include glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, urethane(meth)acrylate, and the like.

[0037] In this specification, "(meth)acrylic" means "acrylic" or "methacrylic." For example, "(meth)acrylate" means "acrylate" or "methacrylate," and "(meth)acrylamide" means "acrylamide" or "methacrylamide."

[0038] Compound (A) is preferably a compound having one or more skeletons selected from the group consisting of a pentaerythritol skeleton, a trimethylolpropane skeleton, a ditrimethylolpropane skeleton, and a diethylene glycol skeleton. For example, if compound (A) has a pentaerythritol skeleton, there may be only one pentaerythritol skeleton present in compound (A). Examples of compound (A) having one pentaerythritol skeleton include the aforementioned pentaerythritol tri(meth)acrylate and pentaerythritol tetra(meth)acrylate.

[0039] In this specification, the pentaeristol skeleton can mean a group formed by removing a hydrogen atom from all or some of the hydroxyl groups of pentaeristol.

[0040] It is preferable that compound (A) does not contain alkylene oxide units. Even if compound (A) contains alkylene oxide units, the average number of added moles is less than 1 mole. It is also preferable that compound (A) does not contain carboxyl groups.

[0041] Compound (A) can be obtained by known manufacturing methods, and can also be obtained from commercially available products.

[0042] Compound (A) may be included in the curable resin composition of the present invention as one or more compounds.

[0043] Nitrogen-containing polymerizable compound (B) The polymerizable component contained in the curable resin composition of the present invention contains a nitrogen-containing polymerizable compound (B) as an essential component. The nitrogen-containing polymerizable compound (B) contained in the curable resin composition of the present invention is the compound represented by formula (1) above.

[0044] The inclusion of the nitrogen-containing polymerizable compound (B) represented by formula (1) as a polymerizable component results in cured products formed from the curable resin composition of the present invention exhibiting excellent adhesion to the substrate, particularly improved adhesion even in humid and hot environments. Furthermore, the inclusion of the nitrogen-containing polymerizable compound (B) as a polymerizable component prevents the curable resin composition of the present invention from becoming excessively viscous, thus resulting in excellent handling properties.

[0045] Nitrogen-containing polymerizable compound (B) is a compound that exhibits radical polymerization.

[0046] As can be seen from the structure shown in formula (1) above, nitrogen-containing polymerizable compound (B) is a (meth)acrylamide derivative, and more specifically, an N-substituted (meth)acrylamide derivative.

[0047] Here, in equation (1) above, R 1 R represents a hydrogen atom or a methyl group. 2 and R 3 R represents a hydrocarbon group which may have substituents and / or heteroatoms, either identical or different. 2 and R 3These are identical or different hydrocarbon groups: "hydrocarbon groups without substituents and heteroatoms," "hydrocarbon groups with substituents and without heteroatoms," "hydrocarbon groups with heteroatoms and without substituents," and "hydrocarbon groups having both substituents and heteroatoms."

[0048] Also, in equation (1), R 2 and R 3 These atoms may bond to each other, with or without heteroatoms, along with the nitrogen atom to which they are bonded, to form a cyclic structure.

[0049] In formula (1), the "hydrocarbon group" can be a linear or branched hydrocarbon group. The number of carbon atoms in the "hydrocarbon group" can be, for example, 1 to 30, 1 to 20, 1 to 15, 1 to 12, 1 to 10, 1 to 6, 1 to 4, 1 to 3, etc., and for example, 3 carbon atoms, 2 carbon atoms, or 1 carbon atom. It is preferable that the "hydrocarbon group" does not have a cyclic structure such as a saturated or unsaturated ring.

[0050] Examples of "hydrocarbon groups" can include alkyl groups, alkenyl groups, and alkynyl groups, with alkyl groups being preferred. Examples of "alkyl groups" can include linear or branched alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, and nonadecyl group. Among these, methyl group, ethyl group, propyl group, and isopropyl group are preferred, with methyl group or ethyl group being particularly preferred in terms of easily increasing adhesion to the substrate, and methyl group being particularly preferred.

[0051] When the hydrocarbon group has the substituents, examples of such substituents include hydroxyl groups, amino groups, phosphate ester groups, sulfate ester groups, halogens, and the like. Such substituents may be bonded to any carbon in the hydrocarbon group.

[0052] When a hydrocarbon group has the heteroatom, examples of such heteroatoms include oxygen, nitrogen, and sulfur. The heteroatom can be inserted into the hydrocarbon group. For example, if the heteroatom is oxygen, one or more -O- moieties can be inserted into the hydrocarbon group. That is, in the case of a hydrocarbon group having oxygen as a heteroatom, the hydrocarbon group may have one or more ether bonds.

[0053] In the above equation (1), R 2 and R 3 If they do not bond to each other to form a ring structure, 2 and R 3 R is preferably the same or different hydrocarbon group without substituents and heteroatoms, more preferably an alkyl group without substituents and heteroatoms, and even more preferably an alkyl group having 10 or fewer carbon atoms. 2 and R 3 The groups may be the same or different, with a methyl group or an ethyl group being more preferable, and a methyl group being particularly preferable.

[0054] In the above equation (1), R 2 and R 3 When the nitrogen-containing polymerizable compound (B) does not bond to each other to form a cyclic structure, various N-alkyl-substituted (meth)acrylamide derivatives can be used as nitrogen-containing polymerizable compound (B). Specifically, examples include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-propyl(meth)acrylamide, and N,N-hydroxyethyl(meth)acrylamide. In terms of forming a cured product that exhibits particularly high adhesion to the substrate in a humid and hot environment, N,N-dimethyl(meth)acrylamide and N,N-diethyl(meth)acrylamide are more preferred as nitrogen-containing polymerizable compound (B), and N,N-dimethyl(meth)acrylamide is even more preferred. It is also preferable that nitrogen-containing polymerizable compound (B) does not have hydroxyl groups.

[0055] Next, R 2and R 3 This section describes the case where these atoms, along with the nitrogen atom to which they bond, bond to each other, either via heteroatoms or without heteroatoms, to form a cyclic structure.

[0056] The aforementioned cyclic structure may be either a saturated ring or an unsaturated ring, and is preferably a saturated ring.

[0057] Even when the compound represented by formula (1) forms the aforementioned cyclic structure, R 2 and R 3 Preferably, all of these are "hydrocarbon groups," and such hydrocarbon groups have 1 to 30 carbon atoms, 1 to 20 carbon atoms, 1 to 15 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, 1 to 3 carbon atoms, etc. For example, 3 carbon atoms, 2 carbon atoms, or 1 carbon atom. In these cases, it is preferable that the hydrocarbon group does not have substituents.

[0058] R 2 and R 3 When these atoms bond with each other along with the nitrogen atom to which they are bonded, R 2 and R 3 The number of carbon atoms in each of these atoms may be the same or different, preferably R 2 and R 3 Each of them has the same number of carbon atoms.

[0059] R 2 and R 3 This means that these can bond to each other via heteroatoms along with the nitrogen atom to which they are bonded, forming a cyclic structure, or R 2 and R 3 These can bond with each other together with the nitrogen atom to which they are bonded, without the need for heteroatoms, to form a cyclic structure. Preferably, R 2 and R 3 This refers to the process where these atoms, along with the nitrogen atom to which they bond, bond to each other via heteroatoms to form a cyclic structure.

[0060] R 2 and R 3In the case where these atoms bond to each other via heteroatoms along with the nitrogen atom to which they bond, the heteroatom can be oxygen, nitrogen, sulfur, etc., and oxygen is preferred.

[0061] In the above equation (1), R 2 and R 3 When these compounds bond to each other to form a cyclic structure, (meth)acryloylmorpholine can be cited as an example of nitrogen-containing polymerizable compound (B).

[0062] Nitrogen-containing polymerizable compound (B) is, in formula (1) above, R 2 and R 3 It is preferable that they do not bond to each other to form a cyclic structure, that is, it is preferable that they are the aforementioned N-alkyl-substituted (meth)acrylamide derivatives, of which N,N-dimethyl(meth)acrylamide and N,N-diethyl(meth)acrylamide are more preferable, and N,N-dimethyl(meth)acrylamide is even more preferable.

[0063] Nitrogen-containing polymerizable compounds (B) can be obtained by known manufacturing methods, and can also be obtained from commercially available products.

[0064] The nitrogen-containing polymerizable compound (B) may be included in the curable resin composition of the present invention by one or more types.

[0065] Other polymerizable components The curable resin composition of the present invention may include, for example, other radical polymerizable components in addition to compound (A) and the nitrogen-containing polymerizable compound (B). As such a radical polymerizable component, compound (C) may be a compound having at least two pentaerythritol skeletons and at least three (meth)acryloyl groups. Hereinafter, a compound having at least two pentaerythritol skeletons and at least three (meth)acryloyl groups will be referred to as "compound (C)".

[0066] In other words, the curable resin composition of the present invention may include embodiments in which the polymerizable component further contains compound (C), wherein compound (C) is a compound having at least two pentaerythritol skeletons and at least three (meth)acryloyl groups.

[0067] Furthermore, if the polymerizable component contains compound (C), then compound (A) and compound (C) are different compounds. In other words, compound (A) is a compound other than compound (C).

[0068] Compound (C) is a compound having at least two pentaerythritol skeletons and at least three (meth)acryloyl groups (i.e., a compound with three or more functional groups). The pentaerythritol skeleton can refer to a group formed by removing hydrogen atoms from all or some of the hydroxyl groups of pentaerythritol, as described above.

[0069] In compound (C), the (meth)acryloyl group may be present, for example, as a substitute for a hydrogen atom in the hydroxyl group in pentaerythritol. That is, it is preferable that the (meth)acryloyl group is bonded to an oxygen atom in the pentaerythritol skeleton.

[0070] Compound (C) is a compound having two or more pentaerythritol skeletons, and examples include polypentaerythritol derivatives such as dipentaerythritol derivatives, tripentaerythritol derivatives, and tetrapentaerythritol derivatives.

[0071] In compound (C), the number of pentaerythritol skeletons is preferably 2 or more and 4 or less, more preferably 2 or 3, and particularly preferably 2.

[0072] In other words, compound (C) is preferably a compound having a dipentaerythritol skeleton. In this case, the cured product formed from the curable resin composition of the present invention has superior scratch resistance and excellent adhesion to the substrate even in a humid and hot environment, and the curable resin composition of the present invention has a lower viscosity and improved handling properties.

[0073] In compound (C), the number of (meth)acryloyl groups is preferably four or more, and more preferably five or more. In particular, when compound (C) is a compound having five or more (meth)acryloyl groups, the cured product formed from the curable resin composition of the present invention has superior scratch resistance and superior adhesion to the substrate even in a humid and hot environment, and the curable resin composition of the present invention has a lower viscosity and superior handling properties.

[0074] In compound (C), the number of (meth)acryloyl groups is preferably 5 or 6. In particular, the curable resin composition of the present invention preferably contains both compound (C) having 5 (meth)acryloyl groups and compound (C) having 6 (meth)acryloyl groups (i.e., the curable resin composition of the present invention preferably contains pentafunctional and hexafunctional compound (C)).

[0075] Compound (C) is a compound having a dipentaerythritol skeleton, and is particularly preferably a compound having five or more (meth)acryloyl groups. Specifically, it is particularly preferably a compound in which a (meth)acryloyl group is bonded to each of the five or more oxygen atoms in the dipentaerythritol skeleton.

[0076] The curable resin composition of the present invention is more preferably to contain both a compound in which a (meth)acryloyl group is bonded to each of the five oxygen atoms in the dipentaerythritol skeleton, and a compound in which a (meth)acryloyl group is bonded to each of the six oxygen atoms in the dipentaerythritol skeleton.

[0077] In compound (C), if a (meth)acryloyl group is not bonded to the oxygen atom in the dipentaerythritol skeleton, a hydrogen atom may be bonded to that oxygen atom (except for oxygen atoms that bond two pentaerythritol skeletons together).

[0078] Specific examples of compound (C) include dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0079] It is preferable that compound (C) does not contain alkylene oxide units. Even if compound (C) contains alkylene oxide units, the average number of added moles is less than 1 mole. It is also preferable that compound (C) does not contain carboxyl groups.

[0080] Compound (C) can be obtained by known manufacturing methods, and can also be obtained from commercially available products.

[0081] Compound (C) may be included in the curable resin composition of the present invention in one or more forms. In particular, it is preferable that the curable resin composition of the present invention includes compound (C) having 5 (meth)acryloyl groups and compound (C) having 6 (meth)acryloyl groups.

[0082] The number of (meth)acryloyl groups in compound (C) can be measured by high-performance liquid chromatography (HPLC). For example, if compound (C) contains two or more compounds with different numbers of (meth)acryloyl groups, the ratio of the two can be determined from the peak area ratio of each compound in the HPLC chart. Specifically, if compound (C) contains both a pentafunctional dipentaerythritol acrylate and a hexafunctional dipentaerythritol acrylate, the ratio of the two can be derived from the peak area ratio of the pentafunctional dipentaerythritol acrylate and the hexafunctional dipentaerythritol acrylate in the resulting HPLC chart.

[0083] The polymerizable component contains compound (A) and the nitrogen-containing polymerizable compound (B) as essential components, as described above, and may optionally contain compound (C). In other words, compound (C) is an optional component included in the polymerizable component.

[0084] The polymerizable component may include other optional components besides compound (C), such as a di(meth)acrylate compound having two (meth)acryloyl groups.

[0085] Examples of di(meth)acrylate compounds include those having an alkylene oxide moiety and two (meth)acryloyl groups. More specifically, di(meth)acrylate compounds are bifunctional (meth)acrylic compounds containing an alkylene oxide moiety and two (meth)acryloyl groups.

[0086] Di(meth)acrylate compounds may have one or more alkylene oxide moieties, and preferably have one alkylene oxide moiety. That is, di(meth)acrylate compounds preferably have one or more moieties composed of repeating alkylene oxide units, and more preferably have one.

[0087] In the alkylene oxide moiety of the di(meth)acrylate compound, the number of carbon atoms in the alkylene is, for example, 1 to 6, preferably 2 or more and 4 or less. Therefore, the alkylene oxide moiety is preferably ethylene oxide or propylene oxide, and is particularly preferably ethylene oxide.

[0088] The average number of added moles of alkylene oxide units at the alkylene oxide moiety is preferably 1 mole or more, and preferably 50 moles or less. In this case, the curable resin composition of the present invention is more likely to form a coating film that is less prone to scratching. The average number of added moles of alkylene oxide units is more preferably 2 moles or more, even more preferably 3 moles or more, particularly preferably 4 moles or more, and more preferably 30 moles or less, even more preferably 20 moles or less, even more preferably 15 moles or less, and particularly preferably 10 moles or less. Note that "average number of added moles of alkylene oxide units" means the average number of added moles of alkylene oxide units at one alkylene oxide moiety in the case of a compound that has two or more alkylene oxide moieties in the molecule.

[0089] A di(meth)acrylate compound may have two or more alkylene oxide molars in its molecule, each with an average addition number of 1 mole or more. In this case, the structures of each alkylene oxide molar may be identical, or at least a part of their structure (e.g., number of carbon atoms, number of addition moles, arrangement order, etc.) may differ. If a di(meth)acrylate compound has two or more alkylene oxide molars in its molecule, all of the alkylene oxide molars may be identical, or at least one of the alkylene oxide molars may be different.

[0090] The average number of added moles of alkylene oxide units is the number of di(meth)acrylate compounds. 1 It can be estimated from the H-NMR spectrum.

[0091] The type of di(meth)acrylate compound is not particularly limited, as long as it is a di(meth)acrylate compound having an alkylene oxide moiety and two (meth)acryloyl groups. For example, the di(meth)acrylate compound preferably has a bisphenol skeleton.

[0092] When a di(meth)acrylate compound has a bisphenol skeleton, the skeleton is not particularly limited. The bisphenol skeleton can be broadly exemplified by any bisphenol skeleton similar to the one exemplified in component (A), and one of these can be selected as the bisphenol skeleton for the di(meth)acrylate compound. That is, it is preferable that the di(meth)acrylate compound has a group formed by removing a hydrogen atom from the hydroxyl group of bisphenol.

[0093] The bisphenol skeleton in the di(meth)acrylate compound can be derived from various bisphenols, such as bisphenol A, bisphenol F, bisphenol P, and bisphenol Z, with bisphenol A being preferred. In other words, in component (A), the bisphenol skeleton is preferably a structure derived from bisphenol A, and is particularly preferably a divalent group formed by removing the hydrogen atoms from the two hydroxyl groups of bisphenol A.

[0094] The di(meth)acrylate compound preferably has a structure in which an alkylene oxide moiety is directly or indirectly bonded to a bisphenol skeleton, and a (meth)acryloyl group is directly or indirectly bonded to the terminal of the alkylene oxide moiety. A more preferred di(meth)acrylate compound has a structure in which two alkylene oxide moieties are directly bonded to one bisphenol skeleton, and a (meth)acryloyl group is directly bonded to the terminal of each alkylene oxide moiety.

[0095] As an example of a di(meth)acrylate compound, alkylene oxide-modified bisphenol A diacrylate having the following structure (compound represented by formula (3)) can be cited.

[0096] [ka]

[0097] In equation (3) above, R5 and R 6 R represents a hydrogen or methyl group that is either identical or different from each other. 3 and R 4 The terms and represent alkylene groups that are either identical or different from each other, and n indicates the average number of added moles of alkylene oxide units.

[0098] In equation (3) above, R 3 and R 4 The alkylene group has 1 to 6 carbon atoms, and is more preferably an alkylene group with 2 to 4 carbon atoms. 3 and R 4 It is particularly preferable that all of these are ethylene groups.

[0099] In formula (3) above, n is a number of 1 or more, more preferably 2 or more, even more preferably 3 or more, particularly preferably 4 or more, more preferably 30 or less, even more preferably 20 or less, and particularly preferably 10 or less. In formula (3) above, the two ns may be the same or different.

[0100] The method for producing di(meth)acrylate compounds is not particularly limited and can be produced by known methods, for example. Alternatively, di(meth)acrylate compounds can be obtained from commercially available products. Examples of commercially available di(meth)acrylate compounds include the New Frontier® series of bifunctional monomers from Daiichi Kogyo Seiyaku Co., Ltd., such as the "New Frontier® BPE" series as EO-modified bisphenol A diacrylate.

[0101] The curable resin composition of the present invention may contain only one di(meth)acrylate compound, or it may contain two or more di(meth)acrylate compounds.

[0102] Other radical polymerizable components include, in addition to the di(meth)acrylate compounds mentioned above, compounds having two to six (meth)acryloyl groups and an average number of added alkylene oxide units of 1 to 20 moles (i.e., 1 mole to 20 moles). Such compounds may have a structure in which at least one hydrogen atom of a hydroxyl group of dipentaerythritol is replaced with an ethylene oxide unit or a (poly)ethylene oxide unit, and in addition, a (meth)acryloyl group is bonded to the oxygen atom at the end of the ethylene oxide unit or polyethylene oxide.

[0103] Furthermore, other radical polymerizable components may be monofunctional polymerizable compounds. For example, compounds having one radical polymerizable vinyl bond can be cited. Examples of such compounds include (meth)acrylic ester compounds, (meth)acrylamide derivatives (excluding compounds represented by formula (1) above), styrene compounds, and the like.

[0104] Polymerizable components As described above, the polymerizable component contained in the curable resin composition of the present invention contains compound (A) and the nitrogen-containing polymerizable compound (B) as essential components, and may further contain compound (C) and the di(meth)acrylate compound, etc., as optional components. Note that the polymerizable component does not contain the photoinitiator described later.

[0105] The polymerizable component preferably includes compound (A), the nitrogen-containing polymerizable compound (B), and compound (C). In this case, the curable resin composition of the present invention is more likely to form a cured product that exhibits particularly excellent adhesion to the substrate even in a humid and hot environment.

[0106] In the polymerizable components, the content of the nitrogen-containing polymerizable compound (B) is preferably, for example, 10% by mass or more and 50% by mass or less, based on the total mass of the polymerizable components. In this case, the cured product formed from the curable resin composition of the present invention has superior scratch resistance and superior adhesion to the substrate even in a humid and hot environment, and the curable resin composition of the present invention has low viscosity and therefore superior handling properties.

[0107] In the polymerizable component, the content of the nitrogen-containing polymerizable compound (B) is more preferably 13% by mass or more, even more preferably 15% by mass or more, even more preferably 18% by mass or more, particularly preferably 20% by mass or more, more preferably 40% by mass or less, even more preferably 35% by mass or less, even more preferably 32% by mass or less, and particularly preferably 30% by mass or less. If the polymerizable component consists only of compound (A) and the nitrogen-containing polymerizable compound (B), the remainder is compound (A).

[0108] When the polymerizable component includes compound (A), nitrogen-containing polymerizable compound (B), and compound (C), the content of compound (A) in the polymerizable component is preferably 5% by mass or more and 45% by mass or less, based on the total mass of the polymerizable component. In this case, the cured product formed from the curable resin composition of the present invention has superior scratch resistance and superior adhesion to the substrate even in a humid and hot environment, and the curable resin composition of the present invention has low viscosity and therefore superior handling properties.

[0109] When the polymerizable component includes compound (A), nitrogen-containing polymerizable compound (B), and compound (C), the content of compound (A) in the polymerizable component is more preferably 8% by mass or more, even more preferably 10% by mass or more, even more preferably 13% by mass or more, particularly preferably 15% by mass or more, more preferably 40% by mass or less, even more preferably 35% by mass or less, and particularly preferably 30% by mass or less.

[0110] When the polymerizable component includes compound (A), nitrogen-containing polymerizable compound (B), and compound (C), the content of nitrogen-containing polymerizable compound (B) in the polymerizable component is preferably 10% by mass or more and 50% by mass or less. In this case, the cured product formed from the curable resin composition of the present invention has superior scratch resistance and superior adhesion to the substrate even in a humid and hot environment, and the curable resin composition of the present invention has low viscosity and therefore superior handling properties.

[0111] When the polymerizable component includes compound (A), nitrogen-containing polymerizable compound (B), and compound (C), the content of nitrogen-containing polymerizable compound (B) is more preferably 13% by mass or more, even more preferably 15% by mass or more, even more preferably 18% by mass or more, particularly preferably 20% by mass or more, more preferably 40% by mass or less, even more preferably 35% by mass or less, even more preferably 32% by mass or less, and particularly preferably 30% by mass or less.

[0112] When the polymerizable component includes compound (A), nitrogen-containing polymerizable compound (B), and compound (C), the content of compound (C) in the polymerizable component is preferably 15% by mass or more and 70% by mass or less. In this case, the cured product formed from the curable resin composition of the present invention has superior scratch resistance and superior adhesion to the substrate even in a humid and hot environment, and the curable resin composition of the present invention has low viscosity and therefore superior handling properties.

[0113] When the polymerizable component includes compound (A), nitrogen-containing polymerizable compound (B), and compound (C), the content of compound (C) is more preferably 25% by mass or more, even more preferably 30% by mass or more, even more preferably 35% by mass or more, particularly preferably 40% by mass or more, more preferably 65% ​​by mass or less, even more preferably 60% by mass or less, and particularly preferably 58% by mass or less.

[0114] In the polymerizable component, the content of compounds other than compound (A), the nitrogen-containing polymerizable compound (B), and compound (C) is preferably 25% by mass or less, and more preferably 20% by mass or less, relative to the total mass of compound (A), the nitrogen-containing polymerizable compound (B), and compound (C), as well as the other radical polymerizable components.

[0115] The content ratio of compound (A), nitrogen-containing polymerizable compound (B), and compound (C) in the polymerizable component is, for example, 75% by mass or more. As a result, the cured product formed from the curable resin composition of the present invention exhibits improved adhesion to the substrate in a humid and hot environment, and can show particularly high adhesion even when the substrate is an acrylic film in a humid and hot environment.

[0116] The content ratio of compound (A), nitrogen-containing polymerizable compound (B), and compound (C) contained in the polymerizable component is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. In these cases, compound (C) may not be included, or it may be included in the above-mentioned content ratio.

[0117] The radical polymerizable component may consist only of compound (A) and the nitrogen-containing polymerizable compound (B), or it may consist only of compound (A), the nitrogen-containing polymerizable compound (B), and compound (C).

[0118] (Carbodiimide compound (L)) The curable resin composition of the present invention contains, in addition to the polymerizable component, a carbodiimide compound (L) as an essential component.

[0119] The curable resin composition of the present invention contains a carbodiimide compound (L), and the cured product formed from this curable resin composition exhibits excellent adhesion to the substrate even when exposed to a humid and hot environment for a long period of time.

[0120] The carbodiimide compound (L) is a compound having a carbodiimide group (-N=C=N-), and it is preferable that the compound has two or more carbodiimide groups in one molecule. That is, it is preferable that the carbodiimide compound (L) is a polycarbodiimide. It is also preferable that the carbodiimide compound (L) contains three or more carbodiimide groups in one molecule.

[0121] Specific examples of carbodiimide compounds (L) include poly(3,5'-dimethyl-4,4'-biphenylmethanecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(4,4'-dicyclohexylmethanecarbodiimide), poly(4,4'-diphenylmethanecarbodiimide), poly(3,5'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(1,3-diisopropylphenylenecarbodiimide), p-phenylene-bis(2,6-xylylcarbodiimide), poly(1-methyl-3,5-diisopropylphenylenecarbodiimide), poly(1,3,5-triethylphenylenecarbodiimide), and poly(triisopropylphenylenecarbodiimide).

[0122] The carbodiimide equivalent of carbodiimide compound (L) is not particularly limited, but is preferably 100 or more, more preferably 200 or more, more preferably 2000 or less, and more preferably 1000 or less. Carbodiimide equivalent refers to the chemical formula weight per mole of carbodiimide groups.

[0123] The method for producing the carbodiimide compound (L) is not particularly limited, and for example, known methods can be widely employed. The carbodiimide compound (L) can be obtained, for example, by carrying out a carbodiimide reaction of an isocyanate compound such as monoisocyanate or diisocyanate in the presence of a carbodiimide catalyst (such as phospholenes).

[0124] Carbodiimide compounds (L) can also be obtained from the market. Examples of commercially available products include Carbodilite V-02 (Nisshinbo Chemical), Carbodilite V-02B (Nisshinbo Chemical), Carbodilite V-02-L2 (Nisshinbo Chemical), Carbodilite V-03 (Nisshinbo Chemical), Carbodilite V-04 (Nisshinbo Chemical), Carbodilite V-05 (Nisshinbo Chemical), Elastostab H01 (BASF), and Stavaxol P (LANXESS).

[0125] The carbodiimide compound (L) contained in the curable resin composition of the present invention may be one type alone or two or more types.

[0126] During the formation of the cured product, the carbodiimide compound (L) does not react with the polymerizable components mentioned above; that is, immediately after the formation of the cured product, most of the carbodiimide compound (L) may exist as carbodiimide compound (L).

[0127] (Curable resin composition) The curable resin composition of the present invention contains the polymerizable component and a carbodiimide compound (L) as essential components. Because the curable resin composition of the present invention contains the polymerizable component, it has the property of curing when exposed to active energy rays such as ultraviolet light. For example, the curable resin composition of the present invention can be said to be an ultraviolet-curable resin composition.

[0128] The curable resin composition of the present invention preferably contains 80% by mass or more of the polymerizable component, more preferably 85% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0129] In the curable resin composition of the present invention, the carbodiimide compound (L) is preferably present in an amount of 0.1 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the total mass of the polymerizable component and the carbodiimide compound (L). In this case, the cured product formed from the curable resin composition of the present invention is more likely to form a cured product that exhibits excellent adhesion to the substrate even when exposed to a humid and hot environment for a long period of time.

[0130] In the curable resin composition of the present invention, the content of the carbodiimide compound (L) is more preferably 0.2 parts by mass or more, even more preferably 0.3 parts by mass or more, particularly preferably 0.4 parts by mass or more, more preferably 2 parts by mass or less, even more preferably 1 part by mass or less, and particularly preferably 0.8 parts by mass or less, based on 100 parts by mass of the total mass of the polymerizable component and the carbodiimide compound (L).

[0131] The curable resin composition of the present invention may contain 75% by mass or more of the polymerizable component and the carbodiimide compound (L), preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0132] In one preferred embodiment of the curable resin composition of the present invention, the total content of compound (A), nitrogen-containing compound (B), compound (C), and carbodiimide compound (L) is 75% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, based on the total amount of the curable resin composition.

[0133] The curable resin composition of the present invention may contain other components in addition to the polymerizable components and carbodiimide compound (L) described above, and it is particularly preferable that it contains a photoinitiator.

[0134] Photoinitiator The photoinitiator has the effect of promoting the polymerization reaction of the polymerizable components (i.e., compound (A), nitrogen-containing polymerizable compound (B), and compound (C), as well as other radical polymerizable components) by active energy rays such as ultraviolet light.

[0135] The photoinitiator preferably contains an acylphosphine oxide-based photopolymerization initiator. In this case, the cured product formed from the curable resin composition of the present invention tends to be highly transparent, i.e., less prone to discoloration. Furthermore, by containing an acylphosphine oxide-based photopolymerization initiator as the photoinitiator in the curable resin composition of the present invention, the cured product formed from the curable resin composition of the present invention tends to have improved adhesion to the substrate.

[0136] Examples of acylphosphine oxide-based photopolymerization initiators include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide.

[0137] Among acylphosphine oxide-based photopolymerization initiators, those with high sensitivity to long-wavelength light are particularly preferred.

[0138] The photoinitiator can include other photoinitiators as long as it contains an acylphosphine oxide-based photopolymerization initiator, and can broadly include known photoinitiators that may be included in conventional active energy ray curable compositions. Examples of other photoinitiators 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 other than visible light, such as ultraviolet 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, and benzyl dimethicone. Examples include Luketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, etc.

[0139] The photoinitiator preferably contains 40% by mass or more of an acylphosphine oxide-based photopolymerization initiator, more preferably 50% by mass or more, even more preferably 70% by mass or more, and particularly preferably 80% by mass or more. The photoinitiator may consist solely of an acylphosphine oxide-based photopolymerization initiator.

[0140] Photoinitiators can be obtained by known manufacturing methods, or they can be obtained from commercially available products. Examples of commercially available acylphosphine oxide-based photopolymerization initiators include IGM Resins BV "Omnirad TPO N", "Omnirad 819", "Omnirad 380", "Omnirad TPO-L", and "Omnirad TP". Among these, "Omnirad 819" is particularly preferred because it is an acylphosphine oxide-based photopolymerization initiator with high sensitivity to long-wavelength light.

[0141] Examples of commercially available photoinitiators other than acylphosphine oxide-based photoinitiators include IGM Resins BV "Omnirad 184" and IGM Resins BV "Omnirad 369".

[0142] The amount of photoinitiator contained in the curable resin composition of the present invention is not particularly limited. For example, the curable resin composition of the present invention may contain 0.1 parts by mass or more and 5 parts by mass or less of the photoinitiator per 100 parts by mass of the total mass of the polymerizable component and the carbodiimide compound (L).

[0143] The curable resin composition of the present invention may contain other components in addition to the polymerizable component, the carbodiimide compound (L), and the photoinitiator. Preferably, the total content of the polymerizable component, the carbodiimide compound (L), and the photoinitiator in the curable resin composition of the present invention is 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 99% by mass or more. The curable resin composition of the present invention may consist only of the polymerizable component, the carbodiimide compound (L), and the photoinitiator.

[0144] The curable resin composition of the present invention preferably does not contain solvents. That is, the curable resin composition of the present invention is preferably a solvent-free composition.

[0145] As described above, the curable resin composition of the present invention is less prone to viscosity increase even when it is solvent-free. Therefore, the curable resin composition of the present invention has excellent handling properties even when it is solvent-free.

[0146] Even if the curable resin composition of the present invention contains a solvent, its content is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 5% by mass or less, and most preferably 1% by mass or less, based on the total mass of the curable resin composition.

[0147] The method for preparing the curable resin composition of the present invention is not particularly limited, and various known methods can be employed, for example. For example, the curable resin composition of the present invention can be prepared by blending and mixing a predetermined amount of polymerizable component and carbodiimide compound (L) with a photoinitiator.

[0148] The curable resin composition of the present invention can form a coating film upon curing. Therefore, the curable resin composition of the present invention can be applied to various applications where the formation of a coating film is required, and is therefore suitably used, for example, as a paint. Specifically, the curable resin composition of the present invention can form a coating film on a substrate. In other words, the curable resin composition of the present invention can be applied to coating applications on various substrates.

[0149] As described above, the cured product obtained from the curable resin composition of the present invention is formed as a coating film such as a film, thin film, or protective film. Such a coating film contains the cured product of the curable resin composition of the present invention. Therefore, because the coating film contains the cured product obtained from the curable resin composition of the present invention, it has excellent scratch resistance and also excellent adhesion to the substrate even in a humid and hot environment, and in particular, its adhesion is maintained over a long period of time.

[0150] The cured product obtained from the curable resin composition of the present invention contains polymers of the polymerizable components.

[0151] By using the curable resin composition of the present invention, a coating film (cured product) can be formed on various substrates. The type of substrate is not particularly limited, but for example, a resin substrate is preferred, and among these, a highly transparent resin substrate is more preferred, and in particular, resin substrates such as polyethylene terephthalate resin and acrylic resin can be used particularly suitably.

[0152] When the substrate is polyethylene terephthalate resin or acrylic resin, the adhesion of the curable resin composition of the present invention to the cured product is particularly enhanced, and high adhesion can be observed even in a humid and hot environment.

[0153] The method for forming a cured product using the curable resin composition of the present invention is not particularly limited, and for example, conventional methods can be broadly applied in the present invention. For example, the curable resin composition is applied to a substrate to a desired thickness to form a film, and the film is cured by irradiating the film with active energy rays. As a result, the film hardens and a cured product can be obtained. The cured product is the coating film, and for example, consists only of the curing components described above.

[0154] When curing the coating, the active energy rays (ultraviolet rays) can be irradiated from the coating side or from the substrate side. In particular, if the photoinitiator contains an acyl phosphine oxide-based photopolymerization initiator, the desired cured product (film) can be obtained even if the active energy rays are irradiated from the substrate side (the side opposite to the side where the coating is formed).

[0155] Examples of active energy rays include ultraviolet rays, electron beams, visible light, X-rays, and ion beams, which can be appropriately selected depending on the type of photoinitiator. Among these, ultraviolet rays or electron beams are preferred from the viewpoint of versatility, and ultraviolet rays are particularly preferred. In other words, the curable resin composition of the present invention can have active energy ray curability, and more specifically, it can have ultraviolet curability.

[0156] Examples of ultraviolet light sources that can be used include chemical lamps, high-pressure mercury lamps, low-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, carbon arc lamps, xenon arc lamps, and electrodeless ultraviolet lamps.

[0157] The thickness of the cured material is not particularly limited and can be adjusted to an appropriate thickness depending on the application. For example, the thickness of the cured material can be 1 to 1000 μm, 1 to 500 μm, 1 to 100 μm, 1 to 50 μm, etc.

[0158] The surface of the cured product obtained from the curable resin composition of the present invention may be flat, or it may have an uneven surface with a predetermined depth, and can be appropriately designed according to the application.

[0159] The cured product of the curable resin composition of the present invention may be used as a film, or a laminate may be formed by forming the cured product of the curable resin composition of the present invention on a substrate, and such laminate may be used as a film.

[0160] In identifying the inventions contained herein, the components (properties, structures, functions, etc.) described in each embodiment of this disclosure may be combined in any way. That is, this disclosure encompasses all subject matter consisting of any combination of the combinatable components described herein. [Examples]

[0161] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to the embodiments of these examples.

[0162] (raw materials) The curable resin compositions for each example and comparative example were prepared by selecting the appropriate raw materials from those listed below.

[0163] First, as polymerizable components, we prepared the following compounds: compound (A), nitrogen-containing polymerizable compound (B), compound (C), other radical polymerizable compounds, and a nitrogen-containing monomer for comparison. <Compound (A)> The following compound (A) (a compound having 3 to 5 (meth)acryloyl groups) was prepared. Pentaerythritol tetraacrylate: Shin-Nakamura Chemical Co., Ltd. "A-TMMT" Pentaerythritol triacrylate: Shin-Nakamura Chemical Co., Ltd. "A-TMM-3L"

[0164] <Nitrogen-containing polymerizable compound (B)> The following nitrogen-containing polymerizable compound (B) was prepared. • DMAA: N,N-dimethylacrylamide (KJ Chemical Co., Ltd. "DMAA") • ACMO: Acryloylmorpholine (KJ Chemical Co., Ltd. "ACMO") • DEAA: N,N-diethylacrylamide (KJ Chemical Co., Ltd. "DEAA")

[0165] <Nitrogen-containing monomers for comparison> • N-(2-hydroxyethyl)acrylamide (abbreviated as 2HEAAm)

[0166] <Compound (C)> The following compounds were prepared as compound (C) (a compound having at least two pentaerythritol skeletons and at least three (meth)acryloyl groups): • Dipentaerythritol acrylate [5-functional / 6-functional = 35 / 65]: Synthesized by Manufacturing Example 1 described below. • Dipentaerythritol acrylate [5-functional / 6-functional = 45 / 55]: Synthesized by the manufacturing example 2 described below. • Dipentaerythritol acrylate [5-functional / 6-functional = 30 / 70]: Synthesized by the manufacturing example 3 described below. • Dipentaerythritol acrylate [5-functional / 6-functional = 15 / 85]: Synthesized by manufacturing example 4 described below. In compound (C), "pentafunctional" means that there are 5 acryloyl groups, and "hexafunctional" means that there are 6 acryloyl groups. Furthermore, in compound (C), the pentafunctional / hexafunctionality indicates the peak area ratio based on pentafunctional dipentaerythritol acrylate and hexafunctional dipentaerythritol acrylate in the HPLC chart obtained from high-performance liquid chromatography (HPLC) measurement of compound (C). The HPLC measurement conditions were as follows. • Equipment used: Prominence-iLC2050C (manufactured by Shimadzu Corporation) • Column: Inertsil ODS-2 (4.6mm inner diameter x 250mm length (manufactured by GL Sciences Co., Ltd.)) Column temperature: 40°C • Mobile phase: Measurement was performed using a gradient elution method with methanol / water = 20 / 80 to 100 / 0.

[0167] <Other radical polymerizable compounds> • EO-modified bisphenol A diacrylate: Daiichi Kogyo Seiyaku Co., Ltd. "New Frontier (registered trademark) BPE-4"

[0168] In addition, the following carbodiimide compounds (L) were prepared. <Carbodiimide compound (L)> • Carbodiimide compound (1): Elastostab H01 (BASF Polyurethanes GmbH) • Carbodiimide compound (2): V-02B (Nisshinbo Chemical)

[0169] The following epoxy crosslinking agents were prepared as comparative materials for the carbodiimide compound (L). <Epoxy crosslinking agent> • Epoxy crosslinking agent: Denacol EX-321 (Nagase ChemteX Corporation)

[0170] The following photoinitiators were prepared. <Photoinitiator> • Acylphosphine oxide system (1): Omnirad 819 (IGM Resins BV) • Acylphosphine oxide system (2): Omnirad TPO-L (IGM Resins BV)

[0171] (Manufacturing example 1: Dipentaerythritol acrylate [5-functional / 6-functional = 35 / 65]) In a four-necked flask equipped with a thermometer, stirrer, and water-cooled condenser, 3459 parts by mass (48.0 moles) of acrylic acid, 1526 parts by mass (6.0 moles) of dipentaerythritol, 187.7 parts by mass of p-toluenesulfonic acid, 9.4 parts by mass of hydroquinone monomethyl ether, and 939 parts by mass of toluene were added and mixed. Then, under reduced pressure, the reaction was carried out while maintaining a reaction temperature of approximately 100°C with the addition of air until 94% of the total hydroxyl groups in the dipentaerythritol were esterified. The reaction was carried out while removing condensation water. After the reaction was complete, neutralization treatment was performed by adding 1.2 times the molar amount of a 25% by mass aqueous sodium hydroxide solution while stirring, thereby removing excess acrylic acid and p-toluenesulfonic acid. Subsequently, the organic layer was separated and washed with water by adding 25 parts by mass of water per 100 parts by mass of the organic layer while stirring. Then, the organic layer was separated again and toluene was removed by distillation under reduced pressure by heating. The obtained dipentaerythritol acrylate was 3600 parts by mass and had a hydroxyl value of 37 mgKOH / g. Thus, a dipentaerythritol acrylate with a pentafunctionality / hexafunctionality ratio of 35 / 65 (representing the area ratio of the two in the HPLC chart; the same applies hereafter) was obtained.

[0172] (Manufacturing example 2: Dipentaerythritol acrylate [5-functional / 6-functional = 45 / 55]) In a four-necked flask equipped with a thermometer, stirrer, and water-cooled condenser, 3166 parts by mass (43.9 moles) of acrylic acid, 1526 parts by mass (6.0 moles) of dipentaerythritol, 187.7 parts by mass of p-toluenesulfonic acid, 9.4 parts by mass of hydroquinone monomethyl ether, and 939 parts by mass of toluene were added and mixed. Then, under reduced pressure, the reaction was carried out while blowing air into the mixture and maintaining a reaction temperature of approximately 100°C until 93% of the total hydroxyl groups in the dipentaerythritol were esterified. The reaction was carried out while removing condensation water. After the reaction was complete, neutralization treatment was performed by adding 1.2 times the molar amount of a 25% by mass aqueous sodium hydroxide solution while stirring, thereby removing excess acrylic acid and p-toluenesulfonic acid. Subsequently, the organic layer was separated and washed with water by adding 25 parts by mass of water per 100 parts by mass of the organic layer while stirring. Then, the organic layer was separated again and toluene was removed by distillation under reduced pressure by heating. The obtained dipentaerythritol acrylate was 3650 parts by mass and had a hydroxyl value of 48 mgKOH / g. Thus, a dipentaerythritol acrylate with a pentafunctional / hexafunctional ratio of 45 / 55 was obtained.

[0173] (Manufacturing example 3: Dipentaerythritol acrylate [5-functional / 6-functional = 30 / 70]) In a four-necked flask equipped with a thermometer, stirrer, and water-cooled condenser, 3675 parts by mass (51.0 moles) of acrylic acid, 1526 parts by mass (6.0 moles) of dipentaerythritol, 187.7 parts by mass of p-toluenesulfonic acid, 9.4 parts by mass of hydroquinone monomethyl ether, and 939 parts by mass of toluene were added and mixed. Then, under reduced pressure, the reaction was carried out while blowing air into the mixture and maintaining a reaction temperature of approximately 100°C until 95% of the total hydroxyl groups in the dipentaerythritol were esterified. The reaction was carried out while removing condensation water. After the reaction was complete, neutralization treatment was performed by adding 1.2 times the molar amount of a 25% by mass aqueous sodium hydroxide solution while stirring, thereby removing excess acrylic acid and p-toluenesulfonic acid. Subsequently, the organic layer was separated and washed with water by adding 25 parts by mass of water per 100 parts by mass of the organic layer while stirring. Then, the organic layer was separated again and toluene was removed by distillation under reduced pressure by heating. The obtained dipentaerythritol acrylate was in the volume of 3550 parts by mass and had a hydroxyl value of 32 mgKOH / g. Thus, a dipentaerythritol acrylate with a pentafunctional / hexafunctional ratio of 30 / 70 was obtained.

[0174] (Manufacturing example 4: Dipentaerythritol acrylate [5-functional / 6-functional = 15 / 85]) In a four-necked flask equipped with a thermometer, stirrer, and water-cooled condenser, 3891 parts by mass (54.0 moles) of acrylic acid, 1526 parts by mass (6.0 moles) of dipentaerythritol, 187.7 parts by mass of p-toluenesulfonic acid, 9.4 parts by mass of hydroquinone monomethyl ether, and 939 parts by mass of toluene were added and mixed. Then, under reduced pressure, the reaction was carried out while maintaining a reaction temperature of approximately 100°C with the addition of air until 98% of the total hydroxyl groups in the dipentaerythritol were esterified. The reaction was carried out while removing condensation water. After the reaction was complete, neutralization treatment was performed by adding 1.2 times the molar amount of a 25% by mass aqueous sodium hydroxide solution while stirring, thereby removing excess acrylic acid and p-toluenesulfonic acid. Subsequently, the organic layer was separated and washed with water by adding 25 parts by mass of water per 100 parts by mass of the organic layer while stirring. Then, the organic layer was separated again and toluene was removed by distillation under reduced pressure by heating. The obtained dipentaerythritol acrylate was 3500 parts by mass and had a hydroxyl value of 16 mgKOH / g. Thus, a dipentaerythritol acrylate with a pentafunctional / hexafunctional ratio of 15 / 85 was obtained.

[0175] (Example 1) A curable resin composition was prepared by selecting raw materials according to the formulation conditions of Example 1 shown in Table 1 below. Specifically, the curable resin composition was prepared by blending 18.25 parts by mass of pentaerythritol tetraacrylate as compound (A), 25.00 parts by mass of DMAA as nitrogen-containing polymerizable compound (B), 56.25 parts by mass of dipentaerythritol acrylate [5-functional / 6-functional = 35 / 65] obtained in Production Example 1 as compound (C), 0.50 parts by mass of carbodiimide compound (1) as carbodiimide compound (L), and 3.00 parts by mass of acylphosphine oxide system (1) as a photoinitiator.

[0176] (Examples 2-7) A curable resin composition was prepared in the same manner as in Example 1, except that the raw materials were selected according to the formulation conditions of each example shown in Table 1 below, and the raw materials were blended in the amounts shown in Table 1.

[0177] (Example 8) A curable resin composition was prepared by selecting raw materials according to the formulation conditions of Example 7 shown in Table 2 below. Specifically, the curable resin composition was prepared by blending 14.60 parts by mass of pentaerythritol tetraacrylate as compound (A), 20.00 parts by mass of DMAA as nitrogen-containing polymerizable compound (B), 45.00 parts by mass of dipentaerythritol acrylate [pentafunctional / hexafunctional = 35 / 65] as compound (C), 20.00 parts by mass of EO-modified bisphenol A diacrylate as another radical polymerizable compound, 0.40 parts by mass of carbodiimide compound (1) as carbodiimide compound (L), and 3.00 parts by mass of acylphosphine oxide system (1) as a photoinitiator.

[0178] (Examples 9-13) A curable resin composition was prepared in the same manner as in Example 1, except that the raw materials were selected according to the formulation conditions of each example shown in Table 2 below, and the raw materials were blended in the amounts shown in Table 2.

[0179] (Examples 14-19) A curable resin composition was prepared in the same manner as in Example 1, except that the raw materials were selected according to the formulation conditions of each example shown in Table 3 below, and the raw materials were blended in the amounts shown in Table 3.

[0180] (Comparative Examples 1-5) A curable resin composition was prepared in the same manner as in Example 1, except that the raw materials were selected according to the formulation conditions of each comparative example shown in Table 4 below, and the raw materials were blended in the amounts shown in Table 4.

[0181] (Evaluation method) [Preparation of cured products from curable resin compositions] The curable resin compositions obtained in each example and comparative example were used as coating liquids to coat an untreated PET film (Lumirror T60) with a thickness of 100 μm, so that the dry film thickness was approximately 10 μm. An easily adhesive PET film (Cosmoshine A4360, 100 μm, manufactured by Toyobo Co., Ltd.) or an acrylic film (manufactured by AS ONE) was then bonded to the coated film (i.e., the coated surface) using a hand roller, and a high-pressure mercury lamp was shone from the substrate side (opposite the untreated PET film) at an illuminance of 470 mW / cm². 2 , cumulative illuminance 600 mJ / cm 2 The coating was cured by irradiation, and a cured product was obtained. By peeling off the untreated PET film, a laminate containing the cured product (coating) of the curable resin composition was obtained as a test specimen (two types of laminates were used as test specimens: one with a PET film as the base material and another with an acrylic film as the base material).

[0182] [Steel wool resistance (scratch resistance)] Of the test specimens obtained as described above, #0000 steel wool was used on the coating surface (cured product) of the test specimen with a PET base material, and a load of 500 g / cm² was applied. 2 The material was polished 10 times, and the state of the hardened material after polishing was visually observed. The steel wool resistance (scratch resistance) was evaluated according to the following criteria. ≪Judgment criteria≫ A: The hardened surface has three or fewer scratches and exhibits extremely excellent scratch resistance. B: Only four to ten scratches can be observed on the surface of the hardened material, indicating excellent scratch resistance. C: More than 10 scratches were observed on the surface of the hardened material, indicating poor scratch resistance.

[0183] [Viscosity (handling properties)] The viscosity of the curable resin composition was measured at 25°C using an E-type viscometer, and its handling properties were evaluated. Specifically, a viscosity of less than 400 mPa·s was judged to be "extremely good handling properties," while a viscosity of 400 mPa·s or higher was judged to be "poor handling properties."

[0184] [Adhesion (initial)] The two types of test specimens obtained as described above (one with a PET substrate and the other with an acrylic film substrate) were stored for 24 hours in a humid environment at 25°C and 65% humidity. After storage, a 1mm grid test in accordance with JIS K5400-8.5:1990 was performed on each specimen, and the following formula was used: Adhesion (%) = 100 - (Number of squares that peeled off) The adhesion was quantified using this method, and a value of 80% or higher was judged to have excellent adhesion.

[0185] [Adhesion (under humid and hot environments)] The two types of test specimens obtained as described above (one with a PET substrate and the other with an acrylic film substrate) were stored for 1000 hours in a humid heat environment at 60°C and 95% humidity. Next, the test specimens were stored for 24 hours in a humid heat environment at 25°C and 65% humidity, and a 1mm grid test in accordance with JIS K5400-8.5:1990 was performed on each test specimen, and the following formula was used. Adhesion (%) = 100 - (Number of squares that peeled off) The adhesion was quantified using this method, and a value of 80% or higher was judged to have excellent adhesion.

[0186] (Evaluation results) Tables 1, 2, 3, and 4 show the formulation conditions and evaluation results (viscosity (handling), adhesion (initial), adhesion (under humid heat conditions), and steel wool resistance (scratch resistance)) for the curable resin compositions prepared in each example and comparative example. In the formulation conditions of Tables 1-4, blank spaces indicate that the raw material was not used.

[0187] In Tables 1-4, compound (B) refers to the nitrogen-containing polymerizable compound (B). Also in Tables 1-4, compound (A), compound (B), compound (C), and other radical polymerizable compounds are the "polymerizable components" in the curable resin composition. Note that photoinitiators are not included in the polymerizable components. Also in Tables 1-4, compound (L) refers to carbodiimide compound (L).

[0188] The "Adhesion (to PET film)" listed in Tables 1-4 refers to the adhesion between the PET film and the cured product (coating). The "Adhesion (to acrylic film)" listed in Tables 1-4 refers to the adhesion between the acrylic film and the cured product (coating). Furthermore, "Initial" refers to the evaluation results of the adhesion (initial) described above, and "Moist heat environment" refers to the evaluation results of the adhesion (under a moist heat environment) described above.

[0189] Tables 1-4 show that the curable resin compositions prepared in each example had low viscosity and excellent handling properties. Furthermore, the cured products obtained using the curable resin compositions prepared in each example contained compound (A), nitrogen-containing polymerizable compound (B), and carbodiimide compound (L), resulting in excellent scratch resistance and excellent adhesion to the substrate even under humid and hot conditions (storage at 60°C and 95% humidity for 1000 hours).

[0190] From the above, it can be seen that a curable resin composition containing a polymerizable component that contains at least a predetermined compound (A) and a nitrogen-containing polymerizable compound (B), and a carbodiimide compound (L), can form a cured product that has excellent scratch resistance and excellent adhesion to the substrate even in a humid and hot environment, and that the curable resin composition has low viscosity and excellent handling properties.

[0191] [Table 1]

[0192] [Table 2]

[0193] Table 3

[0194] Table 4

Claims

1. A curable resin composition, It contains at least a polymerizable component and a carbodiimide compound (L), The polymerizable component is, A compound (A) having three to five (meth)acryloyl groups and a nitrogen-containing polymerizable compound (B) are included in at least one of these compounds. The nitrogen-containing polymerizable compound (B) is one or more selected from the group consisting of N,N-dimethylacrylamide, N,N-diethylacrylamide, and acryloylmorpholine. The carbodiimide compound (L) is present in an amount of 0.1 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the total mass of the polymerizable component and the carbodiimide compound (L). The content of compound (A) is 5% by mass or more and 45% by mass or less, based on the total mass of the polymerizable component. A curable resin composition in which the content of the nitrogen-containing polymerizable compound (B) is 10% by mass or more and 50% by mass or less, based on the total mass of the polymerizable components.

2. The polymerizable component further contains compound (C), The compound (C) is a compound having at least two pentaerythritol skeletons and at least three (meth)acryloyl groups, The compound (A) is a compound other than the compound (C), The curable resin composition according to claim 1, wherein the content of compound (C) in the polymerizable component is 15% by mass or more and 70% by mass or less.

3. A curable resin composition, It contains at least a polymerizable component and a carbodiimide compound (L), The polymerizable component is, A compound (A) having three to five (meth)acryloyl groups and a nitrogen-containing polymerizable compound (B) are included in at least one of these compounds. The nitrogen-containing polymerizable compound (B) is one or more selected from the group consisting of N,N-dimethylacrylamide, N,N-diethylacrylamide, and acryloylmorpholine. The carbodiimide compound (L) is present in an amount of 0.1 parts by mass or more and 5 parts by mass or less based on 100 parts by mass of the total mass of the polymerizable component and the carbodiimide compound (L). A curable resin composition in which the content of the nitrogen-containing polymerizable compound (B) is 10% by mass or more and 50% by mass or less with respect to the total mass of the polymerizable component, and the remainder is the compound (A).

4. The curable resin composition according to claim 1, comprising 75% by mass or more of the polymerizable component and the carbodiimide compound (L).

5. The curable resin composition according to claim 1, wherein the compound (C) is a compound having five or more (meth)acryloyl groups.

6. The curable resin composition according to claim 1, wherein the compound (C) is a compound having a dipentaerythritol skeleton.

7. A curable resin composition according to claim 1, comprising a photoinitiator.

8. A curable resin composition according to claim 1, for use as a paint.

9. A coating film containing a cured product of the curable resin composition according to any one of claims 1 to 8.

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