A hard coating agent with excellent adhesion to the substrate.

Abstract

To provide a hard coating agent that is cured with ultraviolet rays, heat or the like to form a hard coat layer with high hardness, while also exhibiting superior adhesion to substrates composed of a poorly adhesive material such as polyvinyl chloride.SOLUTION: A hard coating agent includes (a) a compound having two or more ethylenically unsaturated groups in each molecule, (b) a free or cationic polymer having an acidic functional group and an amino group and (c) a polymerization initiator.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hard coating agent, and more specifically, to a hard coating agent that can be cured by sunlight, heat, etc. to form a hard coating layer, and has excellent adhesion to difficult-to-adhere substrates such as polyvinyl chloride, and its applications. [Background technology]

[0002] Plastic substrates such as plastic sheets and plastic films, and inorganic substrates such as glass, are often provided with a hard coat layer for purposes such as providing scratch resistance to their surfaces. From the perspective of process flexibility regarding curing timing and curing time, hard coat agents that can be cured by ultraviolet irradiation or thermal radical generators have been proposed for use in forming hard coat layers. For example, Patent Document 1 proposes a hard coat agent that exhibits excellent curability even with low-light active energy rays, using a system containing a compound having an ethylenically unsaturated group and an acidic group, a compound containing an ethylenically unsaturated group and a basic group, and water, further using a glycerin diacrylate / glycerin triacrylate mixture as a crosslinking agent.

[0003] In recent years, the range of substrates to which a hard coat layer can be applied has expanded considerably, and accordingly, hard coat agents that exhibit excellent substrate adhesion not only to organic substrates but also to inorganic substrates have been proposed (see, for example, Patent Document 2). However, conventional hard coating agents, including those described in Patent Document 2, have not always achieved excellent adhesion to substrates such as polyvinyl chloride, and improvements have been needed. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-188607 [Patent Document 2] Japanese Patent Publication No. 2022-160186 [Overview of the project] [Problems that the invention aims to solve]

[0005] In view of the limitations of the conventional technology described above, the present invention aims to provide a hard coating agent that can harden with ultraviolet light, heat, etc., to form a hard coating layer with high hardness, and that also exhibits excellent adhesion to substrates made of difficult-to-adhere materials such as polyvinyl chloride. [Means for solving the problem]

[0006] As a result of diligent research, the inventors discovered that by adding a free or cationic polymer having acidic functional groups and amino groups to a hard coat agent composition, the adhesion to substrates containing difficult-to-adhere materials such as polyvinyl chloride can be significantly improved, thus completing the present invention. In other words, the present invention is [1] (a) Compounds having two or more ethylenically unsaturated groups in the molecule, (b) Free or cationic polymers having acidic functional groups and amino groups, (c) polymerization initiator, This relates to a hard coating agent containing [a specific ingredient / material].

[0007] Hereinafter, [2] to

[11] are all preferred embodiments or models of the present invention. [2] (a) The hard coat agent according to [1], wherein the compound having two or more ethylenically unsaturated groups in the molecule is a diacrylate or a triacrylate. [3] (b) The hard coating agent according to [1] or [2], wherein the free or cationic polymer having an acidic functional group and an amino group comprises a constituent unit (1) having an acidic functional group and a constituent unit (2) having an amino group. [4] The hard coating agent according to [3], wherein the constituent unit (1) having an acidic functional group is derived from (i) a compound having an ethylenically unsaturated group and an acidic group in the molecule. [5] The hard coating agent according to [3] or [4], wherein the constituent unit (2) having an amino group is (2a) an allylamine-based constituent unit or (2b) a diallylamine-based constituent unit. [6] A hard coating agent according to any one of items [3] to [5], wherein the molar ratio of a constituent unit (1) having an acidic functional group to a constituent unit (2) having an amino group is 10:1 to 1:20. [7] (b) The hard coat agent according to any one of [1] to [6], wherein the amount of free or cationic polymer having acidic functional groups and amino groups added is 1 to 50% by mass relative to the total mass of the hard coat agent. [8] (c) The hard coat agent according to any one of the items [1] to [7], wherein the polymerization initiator is (c1) a photopolymerization initiator or (c2) a thermal radical generator. [9] Furthermore, the hard coat agent according to any one of [1] to [8] contains (d1) a compound having one or more epoxy groups and one or more ethylenically unsaturated groups.

[10] Furthermore, (e) a hard coating agent according to any one of items [1] to [9], comprising a surfactant.

[11] A hard coating agent according to any one of [1] to

[10] , for coating substrates made of polyvinyl chloride, GFRP, ABS, PET, or poly(meth)acrylic.

[12] A method for manufacturing a hard-coated article, comprising the steps of applying a hard coat agent described in any one of items [1] to

[10] onto a substrate, and curing the hard coat agent.

[13] The method for manufacturing a hard-coated article according to

[12] , wherein the substrate is made of polyvinyl chloride, GFRP, ABS, PET, or poly(meth)acrylic.

[14] In the step of curing the hard coat agent, ultraviolet irradiation or heating is performed, and the method for producing an article with a hard coat according to

[12] or

[13] .

Advantages of the Invention

[0008] The hard coat agent of the present invention has a practically high value in that it can form a hard coat layer with high hardness by curing with ultraviolet rays, heat, etc., and also has excellent adhesion to a substrate containing a material with poor adhesion such as polyvinyl chloride. It has characteristics, has a high degree of freedom in the process, and can be suitably used for forming a hard coat layer on substrates and members composed of a wide variety of materials.

Embodiments for Carrying Out the Invention

[0009] The hard coat agent of the present invention (a) a compound having two or more ethylenically unsaturated groups in the molecule, (b) a free or cationic polymer having an acidic functional group and an amino group (c) a polymerization initiator, contains each of the components. Hereinafter, each component will be described in detail.

[0010] (a) Compounds having two or more ethylenically unsaturated groups in the molecule The hard coat agent of the present invention contains (a) a compound having two or more ethylenically unsaturated groups in the molecule. Component (a) functions as a crosslinking agent or the like and can impart appropriate curability to the hard coat agent of the present invention. Also, the viscosity and other physical properties of the hard coat agent can be adjusted. Component (a) may be any compound having two or more ethylenically unsaturated groups in the molecule, and is not particularly limited otherwise. Since component (a) is a compound having two or more ethylenically unsaturated groups, it can also be called a "polyfunctional ethylenically unsaturated compound".

[0011] (a) Examples of components include (meth)acrylates having two (meth)acryloyl groups (hereinafter referred to as "bifunctional (meth)acrylates") and (meth)acrylates having two or more (meth)acryloyl groups (hereinafter referred to as "trifunctional or more (meth)acrylates").

[0012] Examples of bifunctional (meth)acrylates include di(meth)acrylates of alkylene oxide adducts of bisphenol A, di(meth)acrylates of alkylene oxide adducts of bisphenol F, di(meth)acrylates of butanediol, di(meth)acrylates of hexanediol and nonanediol; di(meth)acrylates of polyols such as dipentaerythritol; and di(meth)acrylates of these polyol alkylene oxide adducts. In this case, examples of alkylene oxides in alkylene oxide adducts include ethylene oxide, propylene oxide and tetramethylene oxide.

[0013] Specifically, as (meth)acrylates with three or more functions, poly(meth)acrylates of polyols such as glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate can be used; di(meth)acrylates of these polyol alkylene oxide adducts can also be used. In this case, examples of alkylene oxides in the alkylene oxide adducts include ethylene oxide, propylene oxide, and tetramethylene oxide.

[0014] (a) The component may have a hydroxyl group, and preferred examples include compounds having a hydroxyl group and two or more (meth)acryloyl groups (hereinafter also referred to as "hydroxyl group-containing polyfunctional (meth)acrylate"). Examples of hydroxyl group-containing polyfunctional (meth)acrylates include trimethylolpropane di(meth)acrylate, glycerin di(meth)acrylate, di or tri(meth)acrylate of pentaerythritol, di or tri(meth)acrylate of ditrimethylolpropane and polyols of di, tri, tetra or penta(meth)acrylate of dipentaerythritol; poly(meth)acrylates of these polyol alkylene oxide adducts; di(meth)acrylate of isocyanuric acid; and di(meth)acrylate of isocyanuric acid alkylene oxide adducts. In this case, examples of alkylene oxides in the alkylene oxide adducts include ethylene oxide, propylene oxide, and tetramethylene oxide.

[0015] (a) As component (a), a hydroxyl group-containing polyfunctional (meth)acrylate is particularly preferred because it has excellent compatibility with other components, including (a), and the hard coat obtained by curing has excellent cured film performance such as hardness. More specifically, glycerin (meth)acrylate is particularly preferred. (a) Only one component may be used, or two or more components may be used in combination. It is particularly preferable to use a combination of a trifunctional or more (meth)acrylate and a hydroxyl group-containing polyfunctional (meth)acrylate. More specifically, it is particularly preferable to use a combination of glycerin tri(meth)acrylate and glycerin di(meth)acrylate.

[0016] There are no particular restrictions on the content ratio of component (a) in the hard coat agent of the present invention, but it is preferably 10 to 90 parts by mass, and particularly preferably 50 to 80 parts by mass, based on 100 parts by mass of the total curable components (component (a) and component (b) described below, and component (d) described below if present). Using component (a) within the above range allows for adjustment of physical properties without impairing the excellent curability and other characteristics of the hard coat agent of the present invention. When using two or more types of component (a), it is preferable to use each component in an amount such that their total mass falls within the above range.

[0017] (b) Free or cationic polymers having acidic functional groups and amino groups The hard coating agent of the present invention contains (b) a free or cationic polymer having an acidic functional group and an amino group (hereinafter also simply referred to as "component (b)"). (b) By containing component (b), the hard coat agent of the present invention can form a hard coat layer that has excellent adhesion to substrates containing difficult-to-adhere materials such as polyvinyl chloride, while maintaining the excellent properties of conventional hard coat agents such as high hardness. (b) One component may be used alone, or two or more components may be used in combination.

[0018] (b) There are no particular restrictions on the amount of component used, but from the viewpoint of further improving substrate adhesion while maintaining the good performance of the hard coat agent, it is preferable that it be 1 to 80 parts by mass, and particularly preferable that it be 1 to 50 parts by mass, based on 100 parts by mass of the total curable components (components (a) and (b), and component (d) below if present). When using the total mass of the hard coat agent as a reference, it is preferable to add component (b) at a concentration of 1 to 50% by mass relative to the total mass of the hard coat agent, and particularly preferable to add it at a concentration of 5 to 25% by mass. When using two or more types of component (b), it is preferable to use each component in an amount such that their total mass falls within the above range.

[0019] (b) The component may be any free or cationic polymer having at least one acidic functional group and at least one amino group in its molecule, and is not otherwise limited. From the standpoint of design and manufacturing flexibility, as well as ease of availability, component (b) is preferably a compound having a constituent unit (1) having an acidic functional group and a constituent unit (2) having an amino group. The constituent unit (1) having an acidic functional group and the constituent unit (2) having an amino group may each be introduced into the structure of component (b) as one type only, or two or more types may be introduced in combination. There are no particular restrictions on the ratio of constituent units (1) having an acidic functional group to constituent units (2) having an amino group, but it is preferable that the molar ratio of constituent units (1) to constituent units (2) be 5:1 to 1:10, and particularly preferable that it be 5:1 to 1:5.

[0020] (1) Constituent units having acidic functional groups Preferred examples of acidic functional groups in the constituent unit (1) having an acidic functional group include sulfonic acid groups, phosphoric acid groups, alkyl sulfate groups, dicarboxylic acid groups, and the like. There are no particular restrictions on the number of acidic functional groups in the constituent unit (1) having acidic functional groups, but it is preferable to have 1 to 4, and particularly preferable to have 1 to 2.

[0021] (b) From the viewpoint of ease of production of free or cationic polymers having acidic functional groups and amino groups, and ease of control of the number of acidic functional groups, it is preferable that the constituent unit (1) having acidic functional groups is derived from (i) a compound having an ethylenically unsaturated group and an acidic group in the molecule (hereinafter also simply referred to as compound (i)). Compound (i) is any compound having at least one ethylenically unsaturated group and at least one acidic group in its molecule, and is not subject to any other restrictions.

[0022] Preferred examples of the ethylenically unsaturated group of compound (i) include (meth)acryloyl group, (meth)allyl group, vinyl group, and styryl group, with (meth)acryloyl group being particularly preferred. Compound (i) is preferably a compound having one ethylenically unsaturated group, and more preferably a compound having one (meth)acryloyl group.

[0023] The acidic group of compound (i) is preferably an acidic group with high acidity, such as a sulfonic acid group, an alkyl sulfate group, or a phosphate group. Compound (i) is preferably a compound having one acidic group.

[0024] Specific examples of preferred compounds as compound (i) include compounds having a sulfonic acid group, such as sulfoalkyl (meth)acrylates like 2-(meth)acrylamido-2-methylpropanesulfonic acid and 2-[(meth)acryloyloxy]ethanesulfonic acid, vinyl sulfonic acid, and allylsulfonic acid. Examples of compounds having alkyl sulfate groups include (meth)acryloyloxypropylene sulfate, polyoxyethylene-1-((meth)allyloxymethyl)alkyl ether sulfate, polyoxyethylene nonylpropenylphenyl ether sulfate alkyl(meth)allylsulfosuccinate, and sulfated esters of {oxirane polyadducts of the reaction product of an alkanol (C=10~14, branched type) and 1-((meth)allyloxy)-2,3-epoxypropane}, mainly composed of ({α-[2-(meth)allyloxy)-1-({[alkyl(C=10~14)]oxy}methyl)ethyl]-ω-hydroxypoly(n=1~100)(oxyethylene)}. Examples of compounds containing a phosphate group include 2-(meth)acryloyloxyethyl acid phosphate.

[0025] Among these compounds, 2-(meth)acrylamide-2-methylpropanesulfonic acid is preferred, and 2-acrylamide-2-methylpropanesulfonic acid is particularly preferred, from the viewpoint of polymerizability and adhesion improvement effects.

[0026] Constituent units having an amino group (2) There are no particular restrictions on the constituent unit (2) having an amino group, but from the viewpoint of improving adhesion, ease of availability, structural controllability, and solubility in water, it is preferable that it be (2a) an allylamine-based constituent unit or (2b) a diallylamine-based constituent unit. In other words, the compound having a constituent unit (1) having an acidic functional group and a constituent unit (2) having an amino group is preferably (b1) an allylamine copolymer having a constituent unit (1) having an acidic functional group, or (b2) a diallylamine copolymer having a constituent unit (1) having an acidic functional group. (b1) It is also preferable to use only one of the allylamine copolymers having an acidic functional group (1) or (b2) a diallylamine copolymer having an acidic functional group (1), and it is also preferable to use two or more in combination.

[0027] (b1) Allylamine copolymer having a constituent unit (1) having an acidic functional group The allylamine copolymer having (1) an acidic functional group component (b1), which is preferably used as component (b) in the present invention, has the above-mentioned (1) acidic functional group component and (2a) allylamine-based component. More specifically, (2a) the allylamine system unit has a structure represented by the following formula (I), or a structure that is an addition salt thereof. In formula (I), R 1 This represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cycloalkyl group having 5 to 6 carbon atoms. R 1 The C1-C12 alkyl group in the formula may be linear, branched, or aralkyl. Examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl, and benzyl groups. Examples of C5-C6 cycloalkyl groups include cyclopentyl and cyclohexyl groups, but the formula is not limited to these. [ka]

[0028] (2a) When the allylamine system unit is an addition salt, the structure is represented by the following formula (I'). [ka] In formula (I'), R 1 As described above, HX represents an inorganic or organic acid, H is a hydrogen atom, and X is not particularly limited as long as it is a group that can form an inorganic or organic acid together with hydrogen. There are no particular restrictions on the type of addition salt, but from the viewpoint of availability and ease of reaction control, for example, hydrochloride, sulfate, phosphate, nitrate, sulfite, phosphate, nitrite, hydrobromide, acetate, amide sulfate, methanesulfonate, trifluoroacetate, p-toluenesulfonate, etc. can be used. Among these, hydrochloride salts, sulfate salts, phosphate salts, and amide sulfate salts are preferred, and hydrochloride salts, sulfate salts, phosphate salts, and amide sulfate salts with structures derived from monoallylamine are particularly preferred.

[0029] (b1) In the allylamine copolymer having a constituent unit (1) having an acidic functional group, there are no particular restrictions on the ratio of the constituent unit (1) having an acidic functional group to the allylamine constituent unit (2a), but it is preferably 10:1 to 1:20 in molar ratio, more preferably 5:1 to 1:10, and particularly preferably 5:1 to 1:5.

[0030] By keeping the ratio of the acidic functional group component (1) to the allylamine-based component (2a) within the above range, it is possible to achieve even more desirable effects, such as even higher adhesion to substrates containing materials that are difficult to adhere to. The ratio of the constituent unit (1) having an acidic functional group to the allylamine-based constituent unit (2a) can be appropriately adjusted by adjusting the proportion of monoallylamine-based monomers used and other polymerization conditions when producing the allylamine copolymer having the constituent unit (1) having an acidic functional group (b1).

[0031] (b1) The allylamine copolymer having the acidic functional group component (1) may consist only of the acidic functional group component (1) and (2a) the allylamine-based component, or it may have other component units. More specifically, the proportion of the other component units in the allylamine copolymer having the acidic functional group component (1) is preferably 0 to 50 mol%, and more preferably 0 to 10 mol%.

[0032] There are no particular restrictions on the other constituent units mentioned above. Such constituent units can be derived by copolymerizing monomers that yield the acidic functional units (1) and (2a) allylamine-based constituent units with monomers that can copolymerize with them as appropriate. Preferred copolymerizable monomers include, but are not limited to, diallylamines such as diallylamine and diallylmethylamine or their addition salts; diallyldialkylammonium salts such as diallyldimethylammonium chloride; acrylamides such as acrylamide, dimethylacrylamide, acryloylmorpholine, N-[3-(dimethylamino)propyl](meth)acrylamide, (3-acrylamidopropyl)trimethylammonium chloride, and (3-methacrylamidopropyl)trimethylammonium chloride; allyl alcohols, ethylene glycol monoallyl ethers, and other allyl ethers. The monomers used to derive the other constituent units mentioned above can be of one type or a combination of two or more types.

[0033] (b1) There are no particular restrictions on the molecular weight of the allylamine copolymer having a constituent unit (1) having an acidic functional group. A suitable (co)polymer with an appropriate molecular weight can be obtained or polymerized depending on the form of use of the hard coat agent and its relationship with other components. From the viewpoint of achieving an appropriate viscosity for the hard coat agent and carrying out polymerization in a practically acceptable time and cost, it is preferable that the weight-average molecular weight (Mw) is 100 to 150,000. It is more preferable that the weight-average molecular weight (Mw) is 500 to 100,000. It is particularly preferable that the weight-average molecular weight (Mw) is 1,000 to 50,000. (b1) The weight-average molecular weight (Mw) of an allylamine copolymer having a constituent unit (1) having an acidic functional group can be measured, for example, by gel permeation chromatography (GPC) using a liquid chromatograph. (b1) The molecular weight of the allylamine copolymer having a constituent unit (1) having an acidic functional group can be appropriately adjusted by adjusting the copolymerization ratio, temperature, time and pressure in the polymerization process, the type and amount of radical initiator used in the polymerization process, etc.

[0034] (b1) There are no particular restrictions on the rotational viscosity [η] of the allylamine copolymer having a constituent unit (1) having an acidic functional group, and it can be set appropriately depending on the form of use of the hard coat agent and its relationship with other components, but it is preferably 10 to 700 mPa·s (25℃), and particularly preferably 10 to 60 mPa·s (25℃). The rotational viscosity [η] can be measured by methods commonly used in this industry, for example, by an AMETEK Brookfield DV-3T digital type B viscometer. Measurement is typically performed using a ULA adapter, with a liquid volume of 16 mL and a liquid temperature of 25°C. The rotational viscosity [η] can also be adjusted as appropriate by adjusting the dilution concentration, copolymerization ratio, temperature, time, and pressure in the polymerization process, and the type and amount of radical initiator used in the polymerization process.

[0035] (b2) Diallylamine copolymer having a constituent unit (1) having an acidic functional group The diallylamine copolymer having the structural unit (1) with an acidic functional group, which is preferably used as the component (b) constituting the hard coat agent of the present invention, has the above-mentioned (1) structural unit with an acidic functional group and (2b) diallylamine-based structural unit. More specifically, the (2b) diallylamine-based structural unit preferably has a structure represented by the following structural formula (IIa) or (IIb), or an inorganic acid salt or organic acid salt thereof, or a structure represented by the following structural formula (IIIa) or (IIIb).

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0036] In the above formulas (IIa) and (IIb), R 2 is more preferably a hydrogen atom, a methyl group, an ethyl group, or a benzyl group, and particularly preferably a hydrogen atom or a methyl group. In the above formulas (IIIa) and (IIIb), R 3 and R4 Each of these is preferably independently a hydrogen atom, a methyl group, an ethyl group, or a benzyl group, and is particularly preferably a hydrogen atom or a methyl group.

[0037] (b2) A diallylamine copolymer having a constituent unit (1) having an acidic functional group may (2b) have a constituent unit of the structure shown in the above structural formula (IIa) or (IIb), i.e., a constituent unit of a free structure, as a diallylamine-based constituent unit, but may also have a constituent unit of an inorganic salt or organic salt of the structure shown in the above structural formula (IIa) or (IIb), i.e., a structure having an addition salt, or a constituent unit of the structure shown in the above structural formula (IIIa) or (IIIb), i.e., a structure having a counterion. (b2) In the production of a diallylamine copolymer having a constituent unit (1) having an acidic functional group, it is preferable from the viewpoint of production cost, etc., to use a diallylamine monomer having an addition salt or a counterion. The process of removing addition salts such as HCl or counterions from the polymer is complicated and can increase costs, so using an addition salt type or counterion type diallylamine copolymer (b2) that can be produced without such a process is a preferred embodiment from the viewpoint of cost, etc. From the viewpoint of ease of availability and controllability of the reaction, the inorganic or organic acid salt of the structure represented by the above structural formula (IIa) or (IIb) is preferably a hydrochloride salt, carboxylate salt, sulfonate salt, or alkyl sulfate salt, and is particularly preferably a hydrochloride salt.

[0038] When the diallylamine copolymer (b2) has a structure represented by the above structural formula (IIIa) or (IIIb) as a diallylamine system constituent unit (2b), the counterion X - There are no particular limitations, but from the viewpoint of ease of availability and controllability of the reaction, chloride ions, carboxylate ions, sulfonate ions, or alkyl sulfate ions are preferred, and chloride ions or ethyl sulfate ions are particularly preferred.

[0039] (b2) In a diallylamine copolymer having a constituent unit (1) having an acidic functional group, one type of (2b) diallylamine constituent unit may be used alone, or multiple types of (2b) diallylamine constituent units having different structures may be used in combination. When using multiple types of different (2b) diallylamine structural units, each diallylamine structural unit may have different structures within the range represented by the same general structural formula (IIa), (IIb), (IIIa), or (IIIb), or it may have different structures represented by different general structural formulas. In the former case, for example, it is represented by the general structural formula (IIa), but R 2 Multiple types of (2b) diallylamine-based constituent units, whose structures differ from each other, may be used. In the latter case, for example, one constituent unit (2) having the structure represented by structural formula (IIa) and another constituent unit (2) having the structure represented by structural formula (IIIa) may be used. (b2) There are no particular restrictions on the content of (2b) diallylamine-based structural units in the diallylamine copolymer having a structural unit (1) having an acidic functional group, but it is preferably 1 mol% or more of the total structural units of the (b2) diallylamine copolymer, and more preferably 5 to 100 mol%.

[0040] (2b) The proportion of diallylamine-based constituent units can be appropriately adjusted by adjusting the proportion of diallylamine-based monomers used in the production of the diallylamine (co)polymer (b2) and other polymerization conditions.

[0041] (b2) The diallylamine copolymer having the acidic functional group component (1) may consist only of the acidic functional group component (1) and (2b) the diallylamine-based component, or it may have other component units. More specifically, the proportion of the other component units in the diallylamine copolymer having the acidic functional group component (1) is preferably 0 to 50 mol%, and more preferably 0 to 10 mol%.

[0042] There are no particular restrictions on the other constituent units mentioned above, and such constituent units can be derived by copolymerizing monomers that can copolymerize with constituent units (1) and (2b) diallylamine-based constituent units having acidic functional groups. Preferred copolymerizable monomers include, but are not limited to, monoallylamines or their addition salts; anionic monomers such as dicarboxylic acids; sulfur dioxide; acrylamides such as acrylamide, acrylamide, dimethylacrylamide, acryloylmorpholine, N-[3-(dimethylamino)propyl](meth)acrylamide, (3-acrylamidopropyl)trimethylammonium chloride, and (3-methacrylamidopropyl)trimethylammonium chloride; allyl alcohols; and allyl ethers such as ethylene glycol monoallyl ether.

[0043] Among these, monoallylamines, anionic monomers such as dicarboxylic acids, sulfur dioxide, and acrylamide are preferably used. The monomers used to derive the other constituent units mentioned above can be one type or a combination of two or more types.

[0044] (b2) There are no particular restrictions on the molecular weight of the diallylamine copolymer having the constituent unit (1) having an acidic functional group. A copolymer with a suitable molecular weight can be obtained or polymerized as appropriate depending on the form of use of the hard coat agent and its relationship with other components. From the viewpoint of achieving an appropriate viscosity for the hard coat agent and carrying out polymerization in a practically acceptable time and cost, it is preferable that the weight-average molecular weight (Mw) is 500 to 200,000. More preferably, the weight-average molecular weight (Mw) is 2,000 to 100,000. Particularly preferable, the weight-average molecular weight (Mw) is 1,000 to 50,000. The weight-average molecular weight (Mw) of the diallylamine copolymer (b2) can be measured, for example, by gel permeation chromatography (GPC) using a liquid chromatograph. The molecular weight of the diallylamine copolymer (b2) can be appropriately adjusted by adjusting the copolymerization composition, temperature, time, and pressure in the polymerization process, and the type and amount of radical initiator used in the polymerization process.

[0045] There are no particular restrictions on the rotational viscosity [η] of the diallylamine copolymer (b2), and it can be set appropriately depending on the form of use of the hard coat agent and its relationship with other components, but it is preferably 20 to 220 mPa·s (25°C), and particularly preferably 20 to 100 mPa·s (25°C). The rotational viscosity [η] can be measured by methods commonly used in this industry, for example, by an AMETEK Brookfield DV-3T digital type B viscometer. Measurement is typically performed using a ULA adapter, with a liquid volume of 16 mL and a liquid temperature of 25°C. The rotational viscosity [η] can also be adjusted as appropriate by adjusting the copolymerization composition, temperature, time, and pressure in the polymerization process, and the type and amount of radical initiator used in the polymerization process.

[0046] (c) Polymerization initiator The hard coating agent of the present invention contains (c) a polymerization initiator. (c) As polymerization initiators, (c1) photopolymerization initiators or (c2) thermal radical generators can be preferably used. When the hard coat agent of the present invention is used as an active energy ray curable composition, in particular when ultraviolet light and visible light are used as the active energy rays, it is preferable to further contain (c1) a photopolymerization initiator from the viewpoint of ease of curing and cost. When used as an electron beam curable composition, it is not necessarily required to include (c1) a photopolymerization initiator, but a small amount may be added as needed to improve curability.

[0047] (c1) Photopolymerization initiator In this embodiment, various known photopolymerization initiators can be used as the (c1) photopolymerization initiator, but a photoradical polymerization initiator is preferred. (c1)Specific examples of photopolymerization initiators include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl Acetophenone compounds such as (L)butan-1-one, diethoxyacetophenone, oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone} and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one; benzophenone compounds such as benzophenone, 4-phenylbenzophenone, 2,4,6-trimethylbenzophenone and 4-benzoyl-4'-methyldiphenyl sulfide; methylbenzoyl formate, oxy α-ketoester compounds such as 2-(2-oxo-2-phenylacetoxyethoxy)ethyl ester of phenylacetic acid and 2-(2-hydroxyethoxy)ethyl ester of oxyphenylacetic acid; phosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide; benzoin, benzoin methyl ether, benzoin ether Examples include, but are not limited to, benzoin compounds such as tyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; titanocene compounds; acetophenone / benzophenone hybrid photoinitiators such as 1-[4-(4-benzoylphenylsulfanyl)phenyl]-2-methyl-2-(4-methylphenylsulfinyl)propan-1-one; oxime ester photopolymerization initiators such as 2-(o-benzoyloxime)-1-[4-(phenylthio)]-1,2-octanedione; and camphorquinone.

[0048] Among these, acetophenone compounds, benzophenone compounds, and phosphine oxide compounds are particularly preferred examples. Acetophenone compounds are especially preferred because they allow for easy acquisition of good curability in air even when the hard coat film is applied as a thin film of a few micrometers or less.

[0049] (c1) When using a photopolymerization initiator, there are no particular restrictions on the amount used, but it is preferably 0.01 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and particularly preferably 1 to 5 parts by mass, per 100 parts by mass of the total amount of curable components (components (a) and (b), and component (d) below if present). Within the above range, the hard coat agent has excellent curability, and the resulting cured film has excellent scratch resistance.

[0050] (c2) Thermal radical generator The hard coating agent of the present invention may contain (c2) a thermal radical generator. By incorporating (c2) a thermal radical generator, the hard coating agent of this embodiment can be used as a thermosetting composition and can be cured by heating. (c2) Various compounds can be used as thermal radical generators, with organic peroxides and azo initiators being preferred.

[0051] Specific examples of organic peroxides include 1,1-bis(t-butylperoxy)2-methylcyclohexane, 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(4,4-di-butylperoxycyclohexyl)propane, and 1,1-bis (t-butylperoxy)cyclododecane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di(m-toluylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5 -Dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxyacetate, 2,2-bis(t-butylperoxy)butane, t-butylperoxybenzoate, n-butyl-4,4-bis(t-butylperoxy)valerate, di-t-butylperoxyisophthalate, α,α'-bis(t-butylperoxy)diisopropylbenzene, dicumylperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylcumylperoxide Examples include, but are not limited to, di-t-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexine, diisopropylbenzene hydroperoxide, t-butyltrimethylsilyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, and t-butyl hydroperoxide.

[0052] Specific examples of azo compounds include, but are not limited to, 1,1'-azobis(cyclohexane-1-carbonitride), 2-(carbamoylazo)isobutyronitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, azodi-t-octane, and azodi-t-butane. These can be used individually or in combination of two or more. Furthermore, combining organic peroxides with reducing agents can accelerate curing through a redox reaction.

[0053] (c2) When using a thermal radical generator, there are no particular restrictions on the amount used, and it can be set appropriately according to the desired performance and application, but for example, it is preferable to use 20 parts by mass or less per 100 parts by mass of the total amount of curable components (components (a) and (b), and component (d) below if present). (c2) When using a thermal radical generator alone, the procedure should be carried out according to the usual standard methods for radical thermal polymerization. However, in some cases, it may be used in combination with (c1) a photopolymerization initiator, and after photocuring, thermal curing may be performed to further improve the reaction rate.

[0054] (d) Other curing components The hard coat agent of the present invention may contain, in addition to the above components (a) to (c), a component that can react with component (a) and / or component (b) to form a cured product (hereinafter also referred to as "(d) other curable component"). (d) Other curable components can react with component (a) and / or component (b) above to form a cured product, and do not fall under either component (a) or component (b). There are no other restrictions, however, it is preferable that the compound has two or more reactive functional groups in its structure.

[0055] Preferred examples of reactive functional groups include, but are not limited to, (meth)acryloyl groups, epoxy groups, urethane-bonded residues, hydroxyl groups, mercapto groups, and amino groups. There are no particular restrictions on the number of reactive functional groups, but as mentioned above, it is preferable to have two or more per molecule, more preferably two to six, and particularly preferable to have two to three. (d) If other curable components have multiple reactive functional groups, they may all be the same reactive functional group, or they may be a combination of multiple types of reactive functional groups.

[0056] (d) The other curable component preferably has one or more epoxy groups as reactive functional groups, and more preferably has one or more ethylenically unsaturated groups. That is, (d) it is preferable to use a compound having one or more epoxy groups and one or more ethylenically unsaturated groups as the other curable component. There are no particular restrictions on the number of epoxy groups, but it is preferable to have 1 to 3, and particularly preferable to have 1 to 2. Preferred ethylenically unsaturated groups include (meth)acryloyl groups, vinyl groups, and allyl groups, with (meth)acryloyl groups being particularly preferred. There are no particular restrictions on the number of ethylenically unsaturated groups, but it is preferably 1 to 6, and particularly preferably 1 to 2. (d1) Compounds having one or more epoxy groups and one or more ethylenically unsaturated groups may or may not have groups other than epoxy groups and one or more ethylenically unsaturated groups, such as hydroxyl groups, ether groups, etc. (d1) Preferred specific examples of compounds having one or more epoxy groups and one or more ethylenically unsaturated groups include glycidyl (meth)acrylate and allyl glycidyl ether.

[0057] (d) Other preferred examples of curable components include, but are not limited to, urethane (meth)acrylates, in addition to the compounds having one or more epoxy groups and one or more ethylenically unsaturated groups as described in (d1) above. (d) When using other curing components, only one type may be used, or two or more types of (d) other curing components may be used in combination.

[0058] (d) When using other curing components, there are no particular restrictions on the amount used, but from the viewpoint of maintaining high hardness and suppressing curing shrinkage, it is preferable that the amount be 1 to 50 parts by mass, and particularly preferable that it be 1 to 20 parts by mass, per 100 parts by mass of the total curing components (components (a), (b), and (d)).

[0059] solvent The (a) compound having two or more ethylenically unsaturated groups in its molecule, and the (b) free or cationic polymer having an acidic functional group and an amino group, used in the hard coat agent of the present invention are often liquid at room temperature, and therefore the hard coat agent of the present invention can be formed without using a solvent. On the other hand, a solvent may be used to adjust the viscosity of the hard coat agent to a preferred range. There are no particular restrictions on the solvent used in this embodiment, but from the viewpoint of the working environment and environmental impact, it is preferable to use an aqueous solvent. By using an aqueous solvent, the hard coat agent of this embodiment does not use volatile organic compounds (VOCs) or its use is significantly reduced, providing a hard coat agent that is suitable from the viewpoint of environmental impact, safety, and other factors.

[0060] There are no particular limitations on the type of aqueous solvent that constitutes the hard coat agent of this embodiment, but water and a mixed solvent of a water-miscible organic solvent and water can be given as preferred examples. From the viewpoint of reducing the amount of organic solvent used, the use of water is particularly preferred. From the viewpoint of appropriately adjusting the properties and curing speed of the hard coat agent, a mixed solvent of a water-miscible organic solvent and water is also suitably used. Conventionally known organic solvents that can be miscible with water can be used. Examples include alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol (IPA), n-butyl alcohol, s-butyl alcohol, isobutyl alcohol, and t-butyl alcohol; esters such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, methoxybutyl acetate, cellosolve acetate, amyl acetate, methyl lactate, ethyl lactate, and butyl lactate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone; amides such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and N,N-dimethylformamide; and sulfoxides such as dimethyl sulfoxide. Among these, alcohols are suitably used, and IPA is particularly suitably used. These water-miscible organic solvents may be used individually or in combination. There are no particular restrictions on the amount used when using an aqueous solvent, but it can be used in an amount such that the total concentration of all curable components (components (a) and (b), and component (d) if present) is 30 to 90% by mass, more preferably 50 to 90% by mass, and especially preferably 70 to 80% by mass.

[0061] (e) Surfactants The hard coat agent of the present invention may contain (e) a surfactant for purposes such as improving the leveling properties during application or improving the uniformity of the hard coat film after curing. In particular, when a cationic polymer is used as component (b) in the present invention, the surface tension of the hard coat agent tends to increase, so it is especially preferable to use (e) a surfactant so as not to impair the leveling properties during application or the uniformity of the hard coat film after curing. There are no particular restrictions on the type of surfactant (e) used in this embodiment, and it can be appropriately selected depending on the coating form of the hard coat agent and the affinity with other components, such as the solvent if one is used. The surfactant (e) may be an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a nonionic surfactant.

[0062] From the viewpoint of improving coating film uniformity, leveling properties, and penetration, fluorine-based surfactants, silicone-based surfactants, alkyl ether-based surfactants, cationic surfactants, etc., are preferably used. Among these, the use of silicone-based surfactants is particularly preferred from the viewpoint of coating film uniformity. Specific examples of preferred silicone-based surfactants include silicone-based polymers and oligomers having silicone chains and polyalkylene oxide chains, and silicone-based polymers and oligomers having silicone chains and polyester chains, with polyether-modified polydimethylsiloxane being particularly preferred. Examples of commercially available products include "BYK-302," "BYK-307," and "BYK-348" from BIC Chemie Japan, and "VORASURF SZ-1919" from DOW.

[0063] Specific examples of preferred fluorinated surfactants include fluorinated polymers and oligomers having a perfluoroalkyl group and a polyalkylene oxide chain, and fluorinated polymers and oligomers having a perfluoroalkyl ether chain and a polyalkylene oxide chain. Examples of commercially available products include the "Surflon" series from AGC Seimi Chemical Co., Ltd., the "Megafac" series from DIC Corporation, and the "Futergent" series from Neos Corporation.

[0064] (e) There are no particular restrictions on the amount of surfactant added, and it can be set appropriately depending on the coating form of the hard coat agent and the physical properties required after curing. Assuming a typical usage pattern for hard coating agents, (e) when a surfactant is used, the amount used is preferably 0.01 to 5.0% by mass, and particularly preferably 0.1 to 1.0% by mass, based on 100 parts by mass of the total amount of curing components (components (a) and (b), and component (d) if present). (e) One type of surfactant may be used, or two or more types may be used in combination.

[0065] The hard coating agent of the present invention may contain, in addition to each of the constituent components of components (a) to (c) above, and preferred components such as component (e) above, if present, other components. Other components may include various known additives conventionally used in hard coating agents, such as UV absorbers, light stabilizers, acidic substances, inorganic particles, antioxidants, silane coupling agents, polymers, acid generators, pigments, dyes, tackifiers, and polymerization inhibitors.

[0066] Specific examples of UV absorbers include 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2-[4-[(2-hydroxy Xy-3-(2-ethylhexyloxy)propyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butyroxyphenyl)-6-(2,4-bisbutyroxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-[1-octyroxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl) Examples of UV absorbers include, but are not limited to, triazine-based UV absorbers such as (nyl)-1,3,5-triazine; benzotriazole-based UV absorbers such as 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole, and 2-[2-hydroxy-5-(2-(meth)acryloyloxyethyl)phenyl]-2H-benzotriazole; benzophenone-based UV absorbers such as 2,4-dihydroxybenzophenone and 2-hydroxy-4-methoxybenzophenone; cyanoacrylate-based UV absorbers such as ethyl-2-cyano-3,3-diphenylacrylate and octyl-2-cyano-3,3-diphenylacrylate; and inorganic particles that absorb ultraviolet light such as titanium dioxide particles, zinc oxide particles, and tin oxide particles.

[0067] Among the aforementioned compounds, benzotriazole-based ultraviolet absorbers are particularly preferred. These ultraviolet absorbers can be used to suppress discoloration of plastic substrates and other materials that are prone to yellowing when exposed to active energy rays, and can also be used to prevent deterioration of articles with hard coat films due to sunlight when used outdoors. When using an ultraviolet absorber, the amount used is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 2 parts by mass, per 100 parts by mass of the total amount of curable components (components (a) and (b), and component (d) if present).

[0068] While known light stabilizers can be used, hindered amine light stabilizers (HALS) are particularly preferred. Specific examples of hindered amine-based light stabilizers include bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)amino]-6-(2-hydroxyethylamine)-1,3,5-triazine, and bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) decandioate ester. Commercially available hindered amine light stabilizers include BASF's TINUVIN 111FDL, TINUVIN 123, TINUVIN 144, TINUVIN 152, TINUVIN 292, and TINUVIN 5100.

[0069] When using a light stabilizer, the amount used is preferably 0.01 to 5 parts by mass, and more preferably 0.1 to 1 part by mass, per 100 parts by mass of the total amount of curable components (components (a) and (b), and component (d) if present).

[0070] The hard coating agent of the present invention exhibits excellent adhesion to organic substrates, inorganic substrates, etc., but the adhesion to the substrate can be further improved by adding an acidic substance. Examples of acidic substances include photoacid generators that produce acid upon irradiation with active energy rays, as well as sulfuric acid, nitric acid, hydrochloric acid, p-toluenesulfonic acid, methanesulfonic acid, and phosphoric acid. Among these, inorganic acids or organic acids are preferred, organic sulfonic acid compounds are more preferred, aromatic sulfonic acid compounds are even more preferred, and p-toluenesulfonic acid is particularly preferred. When using an acidic substance, the amount used is preferably 0.0001 to 200 parts by mass, and more preferably 0.0005 to 100 parts by mass, per 100 parts by mass of the total amount of the curing components (components (a) and (b), and component (d) if present). Within this range, adhesion to the substrate is superior, and problems such as corrosion of the substrate and decomposition of other components can be prevented.

[0071] The hard coating agent of the present invention may further contain an antioxidant for the purpose of improving the heat resistance and weather resistance of the hard coating film. Examples of antioxidants used in this embodiment include phenolic antioxidants, phosphorus-based antioxidants, or sulfur-based antioxidants. As phenolic antioxidants, hindered phenols such as di-t-butylhydroxytoluene are preferred examples. Commercially available examples include AO-20, AO-30, AO-40, AO-50, AO-60, AO-70, and AO-80 manufactured by ADEKA Corporation. Preferred phosphorus-based antioxidants include phosphines such as trialkylphosphines and triarylphosphines, as well as trialkyl phosphites and triaryl phosphites. Commercially available derivatives of these include, for example, Adeka Stab PEP-4C, PEP-8, PEP-24G, PEP-36, HP-10, 260, 522A, 329K, 1178, 1500, 135A, and 3010, all manufactured by Adeka Corporation. Examples of sulfur-based antioxidants include thioether compounds, and commercially available products include AO-23, AO-412S, and AO-503A manufactured by ADEKA Corporation.

[0072] When using an antioxidant, the amount used is preferably 0.001 to 5 parts by mass, and more preferably 0.001 to 1 part by mass, per 100 parts by mass of the total amount of curing components (components (a) and (b), and component (d) if present). With the above amount of additive, the hard coat agent has excellent stability, as well as good curability and adhesion.

[0073] There are no particular restrictions on how the hard coating agent of the present invention can be used, and it can be used in accordance with methods commonly used in the art. For example, a hard-coated article can be manufactured by applying a hard coat agent to the substrate using a conventional painting method, and then curing the hard coat agent. Hard coating agents can be cured by irradiating them with active energy rays, preferably ultraviolet rays, or by heating. The ability to cure them with active energy rays or heating improves the degree of flexibility in the curing process, such as the timing and duration of curing. The method of irradiation with active energy rays, preferably ultraviolet light, can be a general method known as a conventional curing method. In the hard coat agent, a method can also be employed in which (c1) a photopolymerization initiator and (c2) a thermal radical generator are used in combination, and the hard coat agent is irradiated with active energy rays, preferably ultraviolet light, and then heat-cured to improve adhesion to the substrate.

[0074] Various materials can be used as substrates to which the hard coating agent of the present invention can be applied, including inorganic materials, organic materials such as plastics, and paper. Specific examples of plastics include polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, ABS resin, polyvinyl alcohol, cellulose acetate resins such as triacetylcellulose and diacetylcellulose, acrylic resin, polycarbonate, polyarylate, cyclic polyolefin resins using cyclic olefins such as polyethersulfone and norbornene as monomers, polyvinyl chloride, epoxy resin, and polyurethane resin. The hard coating agent of the present invention exhibits excellent adhesion to substrates containing poorly bondable materials such as polyvinyl chloride, GFRP, ABS, PET, or poly(meth)acrylic resin, and is therefore particularly suitable for forming a hard coating layer on substrates containing these poorly bondable materials.

[0075] The method for applying the hard coat agent of the present invention to a substrate can be appropriately set according to the purpose, but examples include coating using a bar coater, applicator, doctor blade, dip coater, roll coater, spin coater, flow coater, knife coater, comma coater, reverse roll coater, die coater, lip coater, spray coater, gravure coater, and microgravure coater.

[0076] The thickness of the hard coat film can be set appropriately depending on the purpose. The thickness after curing can be selected according to the substrate used and the intended use of the substrate with the manufactured hard coat film, but it is preferably 1 to 100 μm, and more preferably 2 to 40 μm.

[0077] If the hard coating agent contains an organic solvent, it is preferable to heat and dry it after coating the substrate to evaporate the organic solvent. The drying temperature is not particularly limited as long as it is below a temperature at which the substrate to be dried does not deform or experience other problems. A preferred heating temperature is 40 to 100°C. The drying time can be set appropriately depending on the substrate to be dried and the heating temperature, and is preferably 0.5 to 20 minutes.

[0078] When the hard coat agent of the present invention is used as an active energy ray curable composition, the active energy rays used for curing include electron beams, ultraviolet rays, and visible light, but ultraviolet rays or visible light are preferred, and ultraviolet rays are particularly preferred. Examples of ultraviolet irradiation devices include high-pressure mercury lamps, metal halide lamps, ultraviolet (UV) electrodeless lamps, and UV-LEDs (ultraviolet light-emitting diodes). The irradiation energy should be set appropriately depending on the type and composition of the active energy rays. As an example, when using a high-pressure mercury lamp, the irradiation energy (integrated luminous intensity) in the UV-A region should be 100 to 8,000 mJ / cm². 2 Preferably, 200-4,000 mJ / cm² 2 This is preferable. Furthermore, when using UV-LEDs, for example, in the case of clear varnish using a 365nm UV-LED, the UV level is 100-1,000 mJ / cm². 2 Preferably, 200-700 mJ / cm² 2 This is preferable.

[0079] When the hard coating agent of the present invention is used as a thermosetting composition, a cured film can be obtained by leaving the cured film standing in a heat-sensitive dryer or the like. The heating temperature can be set appropriately depending on the substrate and purpose, but 40 to 180°C is preferable. If the substrate is plastic, it is preferable to keep the temperature below 100°C, as excessively high temperatures may cause the substrate to deform. The heating time can be set appropriately depending on the substrate and heating temperature, and is preferably 0.5 to 60 minutes.

[0080] Because the hard coating agent of the present invention can be activated by active energy rays or heating, it offers a high degree of process flexibility regarding curing timing and curing time, and also exhibits excellent adhesion to various substrates, including those containing materials that are difficult to adhere to. Therefore, it can be suitably used with a high degree of process flexibility in forming hard coating layers on various organic substrates such as polyvinyl chloride, GFRP, ABS, PET, and acrylic resins.

[0081] Furthermore, in preferred embodiments of the present invention, the use of volatile organic compounds (VOCs) can be eliminated or significantly reduced by not using a solvent or by using an aqueous solvent. This significantly improves the working environment in the manufacture, storage, and use of hard coating agents, and also significantly reduces the environmental burden.

[0082] More specific examples of applications for the hard coat layer include resin flooring materials. [Examples]

[0083] The present invention will be described in more detail below with reference to the examples and comparative examples. However, the scope of the present invention is not limited in any way by these examples and comparative examples.

[0084] In the following examples / comparative examples, the characteristics were measured and evaluated according to the following methods. (Preparation of test specimens with coatings) The hard coat composition of each example / comparative example was coated onto a rigid polyvinyl chloride substrate manufactured by Kasai Sangyo Co., Ltd. using a bar coater (No. 16) to a thickness of approximately 32 μm to prepare a test specimen. This test specimen was irradiated from approximately 15 cm above it using a UV conveyor device, i-mini Grandage (manufactured by i-Graphics Co., Ltd., ECS-1511U, 1.5kW mercury lamp, cold filter). The conveyor belt speed is 4 meters per minute, and the test specimen has an accumulated light intensity of approximately 660 mJ / cm². 2 The light was irradiated twice to allow it to receive the light.

[0085] (Appearance of the coating) The cured coating obtained above was examined by touch and visual inspection to evaluate the presence or absence of tack, unevenness, whitening, peeling, repelling, and cracking.

[0086] (Pencil hardness) The pencil hardness of the cured coating obtained above was evaluated using the method of JIS K5600-5-4 (load 750±10g).

[0087] (Scratch resistance) The surface of the cured coating obtained above was rubbed 10 times back and forth using a melamine sponge. The surface after rubbing was visually inspected under a three-wavelength fluorescent lamp, and the scratch resistance was evaluated according to the following criteria. ○: The number of scratches was 5 or less. ×: There were 5 or more scratches.

[0088] (Adhesion to substrate) The adhesion of the cured test specimens to the substrate was evaluated using the method of JIS K5600-5-6. Specifically, based on JIS K5600-5-6 (General Test Method for Adhesion of Paints), the cured paint film was cut into a grid of 1 mm intervals to create 100 squares. Cellophane tape manufactured by Nichiban Co., Ltd. was then applied to these squares and quickly peeled off, and the result was determined by "number of normal squares / 100 squares".

[0089] (Stain-resistant) On the surface of the cured coating obtained above, marks were arbitrarily made with an oil-based marker, and immediately wiped off. Those that could be wiped off without leaving any visible stains were marked with a circle (○), and those that could not be wiped off were marked with a cross (×).

[0090] (water resistance) The hardened test specimens obtained above were immersed in 60°C water for 24 hours. Those showing delamination were marked with ×, and those not showing delamination were marked with ○.

[0091] (Example 1) (b) 16.88 parts by mass of diallylamine hydrochloride / 2-acrylamide-2-methylpropanesulfonic acid copolymer (copolymerization molar ratio: 3:1, molecular weight: 2,500, "P(DAA-HCl / AMPS=3 / 1)" in Table 1) was used as component, and to this, 1.13 parts by mass of Surflon S242 (manufactured by AGC Seimi Chemical Co., Ltd., "S-242" in Table 1) was added as a surfactant to prepare solution A. (a) 24.64 parts by mass of a mixture of glycerin diacrylate / glycerin triacrylate (manufactured by Toagosei Co., Ltd., trade name: Aronics M-920, referred to as "M-920" in Table 1) and 2.79 parts by mass of dipentaerythritol hexaacrylate (referred to as "DPHA" in Table 1) as component (c1) 1.81 parts by mass of 2-hydroxycyclohexyl phenyl ketone (manufactured by Tokyo Chemical Industry Co., Ltd., referred to as "HCPK" in Table 1) and (e) 0.36 parts by mass of BYK-307 (trade name, surfactant manufactured by Bic Chemie Japan Co., Ltd., also referred to as "BYK-307" in Table 1) were weighed out and mixed to prepare solution B. The above-mentioned solutions A and B were mixed separately at 40°C for 30 minutes, and then mixed in a mass ratio of A:B = 1:5. The mixture was then thoroughly stirred at room temperature to prepare a hard coat solution. Using the prepared hard coat solution, test specimens with coated films were prepared and evaluated according to the method described above. The evaluation results are shown in Table 1.

[0092] (Examples 2-10, Comparative Examples 1-3) A hard coat composition was prepared and evaluated in the same manner as in Example 1, except that the starting materials and quantities used were changed to those shown in Table 1. The details of the components that differ from those in Example 1 in Table 1 are as follows. The amounts of these components used, including the aqueous solvent, are shown in Table 1. P(DAA-HCl / AMPS=2 / 1): Diallylamine hydrochloride / 2-acrylamido-2-methylpropanesulfonic acid copolymer (molar copolymer ratio: 2:1, molecular weight: 67,000) P(DAA-HCl / AMPS=1 / 1): Diallylamine hydrochloride / 2-acrylamido-2-methylpropanesulfonic acid copolymer (molar copolymer ratio: 1:1, molecular weight: 15,000) P(DAA-HCl / AMPS=1 / 2): Diallylamine hydrochloride / 2-acrylamido-2-methylpropanesulfonic acid copolymer (molar copolymer ratio: 1:2, molecular weight: 35,000) P(DAMA-HCl / AMPS=3 / 1): Diallylmethylamine hydrochloride / 2-acrylamido-2-methylpropanesulfonic acid copolymer (molar copolymer ratio: 3:1, molecular weight: 65,000) P(DADMAC / AMPS=2 / 1): Diallyldimethylammonium chloride / 2-acrylamido-2-methylpropanesulfonic acid copolymer (molar copolymerization ratio: 2:1, molecular weight: 53,000) • PAS-2141CL: Diallylamine hydrochloride / acrylamide copolymer (copolymerization molar ratio 8 / 1) (manufactured by Nitto Boseki Medical Co., Ltd., product name: PAS-2141CL, concentration 25%) • PAS-21CL: Diallylamine hydrochloride polymer (manufactured by Nitto Boseki Medical Co., Ltd., product name: PAS-21CL, concentration 26%) • BYK-302: Surfactant manufactured by Big Chemie Japan Co., Ltd. (Product name: BYK-302) AMPS: 2-acrylamido-2-methylpropanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd., concentration 98%) The results are shown in Table 1.

[0093] [Table 1] [Industrial applicability]

[0094] The hard coat agent of the present invention can form a hard coat layer with high hardness by curing with ultraviolet light, heat, etc., and also exhibits excellent adhesion to substrates containing difficult-to-adhere materials such as polyvinyl chloride. Therefore, it can be suitably used with a high degree of process freedom in forming hard coat layers on substrates and components made of a wide range of materials in display devices, electrical and electronic equipment, transportation machinery, optical equipment, building materials, etc., and has high applicability in various industrial fields, including the electrical and electronics industry, the automotive industry, the optical industry, and the building and construction industry.

Claims

1. (a) Compounds having two or more ethylenically unsaturated groups in the molecule, (b) Free or cationic polymers having acidic functional groups and amino groups, and (c) polymerization initiator, A hard coating agent containing, (b) A free or cationic polymer having an acidic functional group and an amino group, comprising a constituent unit (1) having an acidic functional group and a constituent unit (2) having an amino group, A constituent unit (1) having an acidic functional group is derived from (i) a compound having an ethylenically unsaturated group and an acidic group in the molecule. The constituent unit (2) having an amino group is (2a) an allylamine-based constituent unit, or (2b) a diallylamine-based constituent unit. A hard coating agent in which the molar ratio of a constituent unit (1) having an acidic functional group to a constituent unit (2) having an amino group is 5:1 to 1:

10.

2. (a) The hard coat agent according to claim 1, wherein the compound having two or more ethylenically unsaturated groups in the molecule is a diacrylate or a triacrylate.

3. (b) The hard coat agent according to claim 1 or 2, wherein the amount of free or cationic polymer having an acidic functional group and an amino group added is 1 to 50% by mass of the total mass of the hard coat agent.

4. (c) The hard coat agent according to claim 1 or 2, wherein the polymerization initiator is (c1) a photopolymerization initiator or (c2) a thermal radical generator.

5. Furthermore, the hard coat agent according to claim 1 or 2, further comprising (d1) a compound having one or more epoxy groups and one or more ethylenically unsaturated groups.

6. The hard coating agent according to claim 1 or 2, further comprising (e) a surfactant.

7. A hard coating agent according to claim 1 or 2, for coating a substrate made of polyvinyl chloride, GFRP, ABS, PET, or poly(meth)acrylic.

8. A method for manufacturing a hard-coated article, comprising the steps of applying a hard coat agent according to claim 1 or 2 onto a substrate, and curing the hard coat agent.

9. The method for manufacturing a hard-coated article according to claim 8, wherein the substrate is a polyvinyl chloride, GFRP, ABS, PET, or poly(meth)acrylic substrate.

10. A method for manufacturing a hard-coated article according to claim 8, wherein the hard-coating agent is cured by irradiation with ultraviolet light or heating.

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