Coating composition, coating layer containing the same, and molded article

Abstract

To provide a coating composition which enables formation of a non-adhesive coat layer that has good adhesion to various resin substrates, and excellent surface hardness, tack resistance, bending resistance, scratch resistance, shrinkage resistance and moist heat resistance and / or an adhesive coat layer having excellent adhesion, stickiness, transparency, stain resistance, moist heat resistance, resistance against yellow discoloration and step followability, a non-adhesive coat layer and an adhesive coat layer formed of the coating composition, various laminates having the coat layer on one surface or both surfaces of the substrate, a cover film, and a substrate.SOLUTION: A coating composition contains 0.5-30.0 mass% of an acrylic polymer (A) having a branched alkyl group having 3 to 20 carbon atoms and / or a branched or non-branched alkenyl group at a side chain, and 70.0-99.5 mass% of a polymerizable compound (B).

Description

[Technical Field]

[0001] The present invention relates to a coating composition, an adhesive or non-adhesive coating layer made of the coating composition, and a laminate comprising these coating layers. [Background technology]

[0002] Thin, plate-shaped glass (glass substrates) with excellent transparency, hardness, and heat resistance have traditionally been used as materials for electronic devices such as display surface materials, touch panel components, liquid crystal display devices, and organic electroluminescent display devices. For example, they are used as display element substrates for displays on which various electronic elements such as thin transistors and transparent electrodes are formed, and as protective cover substrates placed on the surface of displays. In addition, adhesives are used to fix laminates of various optical films to the glass substrate of liquid crystal display (LCD) cells in order to improve the display quality of the display, and adhesives are also used to prevent cracking of protective cover glass and to prevent scattering of shattered glass if it does break.

[0003] However, glass substrates have drawbacks in terms of processability and handling, such as being difficult to bend and prone to breakage, as well as being heavier than plastic products. Therefore, in order to strengthen the impact resistance of the panel itself, make it more flexible, thinner, and lighter, resin products such as resin substrates and resin films are gradually replacing glass products, and research is being conducted on resin products that can serve as glass substitutes from the perspective of processability and weight reduction. In particular, fluororesin films and polyimide films, which have excellent heat resistance, dimensional stability, and insulating properties, are being widely used as insulating materials for electronic components such as chip coating films in semiconductor devices and substrates for flexible printed circuit boards. In recent years, research on resin products using polyimide resin with improved transparency has attracted particular attention as a glass substitute.

[0004] On the other hand, when using resin products, such as resin-based films (also called base film or resin film), resin-based sheets (also called base sheet or resin sheet), or resin-based substrates (also called base substrate or resin substrate), adhesives are needed between these resin products, such as resin films, resin sheets, and resin substrates, for purposes such as fixing the resin sheet for display elements to the optical film laminate, or fixing the resin substrate for cover (surface protection). However, conventional inexpensive and easy-to-handle acrylic adhesives do not provide sufficient adhesion to these resin products, leading to new problems such as unsatisfactory blister resistance and reworkability. In particular, fluororesin films and polyimide films have poor compatibility with general-purpose adhesives and adhesive layers formed from adhesives, resulting in significant drawbacks such as poor adhesion, making practical application difficult. Furthermore, when these resin products are used as protective cover substrates or cover films, they have excellent processability as materials for flexible display devices, but their insufficient surface hardness and scratch resistance prevent their practical application.

[0005] To protect the surface of resin substrates such as polyimide films and to improve surface hardness and scratch resistance, it has been proposed to provide a hard coat layer on the surface (one or both sides) of the polyimide film. For example, Patent Document 1 proposes applying a coating liquid consisting of a polyfunctional acrylate and a photoinitiator to the surface of a polyimide film and forming a hard coat layer by ultraviolet irradiation. Patent Document 2 proposes applying a resin composition consisting of a urethane acrylate-based hard coat agent with a benzene ring content of 50% by mass or more and a hard coat agent having an epoxy skeleton to the surface of a polyimide film and forming a hard coat layer by photocuring.

[0006] However, the cured layer disclosed in Patent Document 1 readily forms a hard coat layer with high crosslink density through photopolymerization of polyfunctional acrylate, improving the surface hardness of the polyimide film. On the other hand, it suffers from poor adhesion between the hard coat layer and the polyimide film. As a result, when used as a flexible material, there is a high possibility of cracks occurring in the hard coat layer due to repeated bending, or of the hard coat layer peeling off from the polyimide film. Meanwhile, the hard coat layer disclosed in Patent Document 2 is intended to protect the polyimide film and is disclosed to have good adhesion to aromatic polyimide films, but the surface hardness, scratch resistance, and bending resistance (folding resistance) of the resulting polyimide film laminate are not mentioned. Furthermore, since the resin composition for the hard coat layer in Patent Document 2 has more than half (50% by mass) rigid benzene ring structures, it is clear that it is not suitable for forming a flexible coat layer.

[0007] Furthermore, because poorly adhering materials such as polyimide have low adhesion to general-purpose coating compositions and coating agents, and low adhesion to other materials, techniques using surface modifiers (wet etching) and techniques combining wet etching and ultraviolet light irradiation have been investigated to improve the adhesion of these film and sheet materials. For example, Patent Document 3 describes a technique to improve the adhesion of a polyimide film surface by applying a surface modifier containing amino alcohol and ammonium salt to the film. Patent Document 4 describes a technique to modify the surface of a polyimide film by wet etching with hydrogen peroxide or hypochlorous acid, and then irradiating it with ultraviolet light at a wavelength of 170 nm to 360 nm. Patent Document 5 describes a technique to modify the surface of a polyimide film by irradiating it with a KrF excimer laser at a wavelength of about 250 nm in the presence of a primary oxidizing agent such as oxygen or ozone, and then etching it with a secondary oxidizing agent such as permanganate.

[0008] However, wet etching alone does not significantly improve the adhesion of the polyimide film, resulting in problems with stable long-term use. Furthermore, the combination of etching and UV irradiation requires chemical treatment such as etching and UV irradiation before the adhesive layer is formed, making the operation complex and requiring special equipment to generate a high-power laser. Moreover, irradiation with high-power laser light may partially alter not only the surface but also the interior of the polyimide film, raising concerns about reduced durability when considering applications in optics and electronic equipment.

[0009] Thus, conventional polyimide films and polyimide film laminates modified using photocurable resin compositions for hard coatings have struggled to achieve both rigid properties such as surface hardness and scratch resistance, and flexible properties such as flexibility and bending resistance. A film laminate that achieves both rigidity and flexibility, and also possesses good adhesion between the coating layer formed from the photocurable resin composition and a base film such as a polyimide film, has not yet been proposed. Furthermore, there is a demand for coating compositions, adhesive compositions, and adhesive layers that maintain the original properties of the resin material while providing good adhesion to the resin surface of various resin films, resin sheets, and resin substrates containing fluororesins and polyimides, without requiring excessive treatment or modification of the surface of these resin materials. In particular, there is a need for adhesive layers and adhesive sheets that can achieve both high adhesion and blister resistance to adhesive layers used for laminating various display element substrates and cover substrates, and various optical films, as well as various base films and sheets, and that exhibit excellent step-following ability, moisture and heat resistance, and weather resistance. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Special Publication No. 2016-501144 [Patent Document 2] Japanese Patent Publication No. 2018-192699 [Patent Document 3] Japanese Patent Publication No. 2003-192811 [Patent Document 4] Japanese Patent Application Publication No. 11-293009 [Patent Document 5] Japanese Patent Application Publication No. 9-157417 [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] In view of the problems of the prior art described above, the present invention aims to provide a coating composition that can form a coating layer having good transparency, resistance to yellowing and curability, excellent surface hardness, resistance to tack, scratch resistance, flexibility, shrinkage resistance and heat and moisture resistance, and excellent adhesion to various resin films, resin sheets and resin substrates containing fluororesin and polyimide; a non-adhesive coating layer and an adhesive coating layer (adhesive layer) formed from the coating composition; and various laminates having the coating layer on one or both sides of various resin substrates (films, sheets, plates, etc.), as well as molded products for optical and electronic devices. [Means for solving the problem]

[0012] As a result of diligent research to solve the above problems, we have found that by using a coating composition containing 0.5 to 30.0% by mass of an acrylic polymer (A) having a branched alkyl group and / or a branched or unbranched alkenyl group with 3 to 20 carbon atoms in its side chain, and 70.0 to 99.5% by mass of a polymerizable compound (B), and applying it to various resin substrates, and performing thermal polymerization and / or polymerization by active energy rays such as light, we can obtain a non-adhesive or adhesive coating layer that satisfies the above properties. By providing these coating layers on one or both sides of the substrate, we can obtain the desired laminate or molded product, and thus complete the present invention.

[0013] In other words, the present invention is (1) A coating composition comprising 0.5 to 30.0% by mass of an acrylic polymer (A) and 70.0 to 99.5% by mass of a polymerizable compound (B), wherein the acrylic polymer (A) has a branched alkyl group having 3 to 20 carbon atoms and / or a branched or unbranched alkenyl group in its side chain. (2) The coating composition according to (1), characterized in that the acrylic polymer (A) has a weight-average molecular weight of 100,000 to 6,000,000 and a glass transition temperature (Tg) of -85°C to 40°C. (3) The coating composition according to (1) or (2) above, characterized in that the acrylic polymer (A) further has a functional group (R1) containing active hydrogen in its side chain (A1), or a functional group (R2) that reacts with the functional group (R1) containing active hydrogen in its side chain (A2), and / or further has a (meth)acryloyl group or an unsaturated alicyclic hydrocarbon group in its side chain (A3). (4) The polymerizable compound (B) contains a monofunctional acrylic monomer (b1) and a polyfunctional acrylic monomer (b2), wherein the content of (b1) is 10.0 to 96.0% by mass of the total coating composition, and the content of (b2) is 0 to 80.0% by mass of the total coating composition, characterized in that the coating composition is as described in any one of (1) to (3) above. (5) The coating composition according to any one of (1) to (4) above, wherein the polymerizable compound (B) further contains a urethane oligomer (b3) (excluding b1 and b2), and the content of (b3) is 2.0 to 50.0% by mass of the total coating composition. (6) The coating composition according to (5) above, characterized in that the urethane oligomer (b3) is a urethane (meth)acrylamide oligomer. (7) A non-stick coating layer obtained by polymerizing the coating composition described in any one of the above items (1) to (6) with light and / or heat. (8) A sticky coating layer obtained by polymerizing the coating composition described in any one of the above items (1) to (6) with light and / or heat. (9) An adhesive sheet having the coating layer described in (7) or (8) on one or both sides of a film-like and / or sheet-like substrate, (10) A laminate having the coating layer described in (7) or (8) on one or both sides of a film-like and / or sheet-like substrate, (11) An optical laminate having the coating layer described in (7) or (8) provided on one or both sides of a film-like and / or sheet-like base material, and having a total light transmittance of 80% or more. (12) A laminate for a flexible device having the coating layer described in (7) or (8) provided on one or both sides of a film-like and / or sheet-like base material. (13) A laminate for surface protection having the coating layer described in (7) or (8) provided on one or both sides of a film-like and / or sheet-like base material. (14) A laminate for a display having the coating layer described in (7) or (8) provided on one or both sides of a film-like and / or sheet-like base material. (15) The film-like base material is any one film selected from a polyester film, a polycarbonate film, a fluororesin film, a polyimide film, a triacetyl cellulose film, an acrylic film, a polystyrene film, a polyvinyl chloride film, a polyvinyl alcohol film, and a nylon film. The laminate according to any one of (10) to (14) above, characterized in that. is provided. [Effect of the Invention]

[0014] The coating composition of the present embodiment contains an acrylic polymer (A) and a polymerizable compound (B) as essential constituent components. Since the acrylic polymer (A) has a branched alkyl group having 3 to 20 carbon atoms and / or a branched or unbranched alkenyl group in its side chain, in the non-adhesive coating layer formed from the coating composition and also in the adhesive coating layer (adhesive layer), the coating layer itself has flexibility and water resistance, and the bending resistance and wet heat resistance of various laminates and molded products provided with such a coating layer are improved. Further, by combining the acrylic polymer (A) and the polymerizable compound (B), the coating composition exhibits excellent affinity (wettability) and adhesion to fluororesin-based and polyimide-based base materials that are difficult to adhere to general-purpose resin base materials such as polyester-based and polycarbonate-based ones.

[0015] Furthermore, polymerizable compound (B) can be used as a raw material monomer for acrylic polymer (A). In this case, even if the acrylic polymer (A) has a high molecular weight, it can be uniformly and stably dissolved in polymerizable compound (B) down to the molecular level. This makes it possible to obtain an extremely transparent coating composition and a coating layer with good transparency and resistance to yellowing, which can be suitably used as optical components and electronic device components.

[0016] Furthermore, it is preferable to use (meth)acrylamide monomers as both the raw material monomer for the acrylic polymer (A) and the polymerizable compound (B). When (meth)acrylamide monomers are used as the raw material monomer for the acrylic polymer (A), numerous amide groups are present in the side chain of A, resulting in strong cohesive force between the amide groups. This cohesive force and the interaction between the hydrophilic amide groups and the hydrophobic main chain of A further improve the adhesion of the resulting coating layer, and prevent adhesive residue and contamination of the adherend when reworking the adhesive coating layer. Also, when (meth)acrylamide monomers are used as the polymerizable compound (B), the polymerizability of B is good, resulting in high polymerizability and curability of the coating composition. Furthermore, because the glass transition temperature of the homopolymer of (meth)acrylamide monomers is high, the resulting non-stick coating layer has excellent surface hardness, tack resistance, and scratch resistance. [Modes for carrying out the invention]

[0017] Embodiments of the present invention will be described in detail below. The first embodiment of the present invention is a coating composition (D). The coating composition (D) according to this embodiment is a composition containing an acrylic polymer (A) having a branched alkyl group with 3 to 20 carbon atoms and / or a branched or unbranched alkenyl group in its side chain, and a polymerizable compound (B). The coating composition (D) can form a coating layer by polymerization by heat (thermal polymerization), polymerization by active energy rays such as light (photopolymerization), or polymerization by a combination of thermal polymerization and photopolymerization (hybrid polymerization). The coating composition can be applied to one or both sides of a film-like or sheet-like substrate and then polymerized by the above-mentioned polymerization methods to form a coating layer. Alternatively, the coating composition can be polymerized by the above-mentioned polymerization methods, and then prepared as a solid such as a powder, or as a solution in the presence of a solvent and a polymerizable compound, and then applied to one or both sides of a film-like or sheet-like substrate and treated with active energy rays such as electricity, heat, or light to form a coating layer. Furthermore, by adjusting the composition of the coating composition, a non-adhesive coating layer for surface protection and topcoating, and an adhesive coating layer used as an adhesive or adhesive layer can be easily obtained.

[0018] A second embodiment of the present invention is a coat layer having a crosslinked structure obtained by curing a coating composition (D). The crosslinked structure of the coat layer can be formed by thermal polymerization, polymerization by active energy rays such as light, or hybrid polymerization of branched or unbranched alkenyl groups (ethylenically unsaturated bonds) having 3 to 20 carbon atoms present in the side chains of an acrylic polymer (A) and a polymerizable compound (B). In the case of a non-adhesive coat layer, the surface hardness, strength, scratch resistance, etc. of the coat layer increase as the crosslinking density increases, making it suitable for use as a top layer coating film or a surface protective layer coating film; therefore, a crosslinked non-adhesive coat layer is preferable. On the other hand, in the case of an adhesive coat layer, the formation of a crosslinked structure improves blister resistance, weather resistance, heat resistance, and substrate stain resistance; therefore, a crosslinked adhesive coat layer is preferable.

[0019] Acrylic polymer (A) may further have a functional group (R1) containing active hydrogen or a functional group (R2) that reacts with the functional group (R1) in its side chain, and these will be referred to as acrylic polymer (A1) and acrylic polymer (A2), respectively. Acrylic polymer (A), acrylic polymer (A1) and acrylic polymer (A2) may be used individually or as a mixture of two or more. When acrylic polymer (A1) is used in a coating composition, if the polymerizable compound (B) contains a reactive functional group (R2), a crosslinked structure can be formed by thermal polymerization, polymerization by active energy rays such as light or hybrid polymerization, and a chemical reaction between acrylic polymer (A1) and polymerizable compound (B) (a chemical reaction between the functional group (R1) and the functional group (R2)). Similarly, when acrylic polymer (A2) is used, if the polymerizable compound (B) contains the aforementioned functional group (R1), a crosslinked structure can be formed. Furthermore, examples of the functional group (R1) having active hydrogen include hydroxyl groups, thiol groups, amino groups, and carboxyl groups, and examples of the functional group (R2) that reacts with R1 include isocyanate groups and glycidyl groups.

[0020] Acrylic polymer (A) may have (meth)acryloyl groups or unsaturated alicyclic hydrocarbon groups in its side chains, and this is referred to as acrylic polymer (A3). The (meth)acryloyl groups or unsaturated alicyclic hydrocarbon groups may be introduced from the raw material monomers of acrylic polymer (A3), or they may be introduced after the synthesis of acrylic polymer (A) via the functional group (R1) or (R2). When acrylic polymer (A3) is used in a coating composition, a crosslinked structure can be formed by thermal polymerization, polymerization by active energy rays such as light, or hybrid polymerization.

[0021] Examples of raw material monomers for acrylic polymer (A) include (meth)acrylic monomers having branched alkyl groups and / or branched or unbranched alkenyl groups with 3 to 20 carbon atoms.

[0022] Examples of (meth)acrylic monomers used as raw materials for acrylic polymer (A) include monomers having one unsaturated bond selected from methacrylate, acrylate, methacrylamide, and acrylamide groups within a single molecule. Furthermore, among the unsaturated bonds, monomers having one selected from acrylate, methacrylate, and acrylamide groups are preferred from the viewpoint of easily obtaining polymers with relatively low glass transition temperatures (hereinafter sometimes abbreviated as Tg).

[0023] Examples of branched alkyl groups having 3 to 20 carbon atoms include isopropyl group, sec-butyl group, tert-butyl group, isobutyl group, 1-methylbutyl group, 2-methylbutyl group, 1,1-dimethylpropyl group, 1,1-dimethylbutyl group, 2,2-dimethylbutyl group, 3,3-dimethylbutyl group, 2-ethylbutyl group, isooctyl group, tert-octyl group, 2-ethylhexyl group, and isodecyl group.

[0024] Examples of branched or unbranched alkenyl groups having 3 to 20 carbon atoms include allyl group, 1-propenyl group, 2-propenyl group, 2-methyl-1-propenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 3-methyl-2-butenyl group, 1,3-butadienyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 4-methyl-3-pentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 5-hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tetradecenyl group, hexadecenyl group, octadecenyl group (oleyl group), eicocenyl group, and dococenyl group.

[0025] The (meth)acrylic monomer, which is a raw material for the acrylic polymer (A), is not limited to any monomer having a structure composed of one unsaturated bond arbitrarily selected from the various (meth)acrylic unsaturated bonds mentioned above, and one substituent arbitrarily selected from the group of branched alkyl groups and / or branched or unbranched alkenyl groups having 3 to 20 carbon atoms.

[0026] The acrylic polymer (A) used in the present invention may be a homopolymer of one monomer arbitrarily selected from the group of (meth)acrylic monomers used as raw materials, or a copolymer of two or more monomers arbitrarily selected from the group, or a copolymer of one or more monomers arbitrarily selected from the group and other monomers (not included in the group). When the acrylic polymer (A) is a copolymer, the content of one or more monomers selected from the group is preferably 30 mol% or more, more preferably 50 mol% or more, and particularly preferably 80 mol% or more. If the content of one or more monomers selected from the group is 30 mol% or more, the Tg of the acrylic polymer (A) can be easily adjusted to a predetermined range (-85°C to 40°C), and adhesion to resin substrates that are difficult to adhere to can be imparted.

[0027] The functional group (R1) of acrylic polymer (A1) and the functional group (R2) of acrylic polymer (A2) may be introduced from their respective raw material monomers, or they may be introduced after the synthesis of acrylic polymer (A) via the monomer having the functional group (R1) or (R2). When calculated on a raw material monomer basis, the content of monomers having the functional group (R1) or (R2) relative to the total raw material monomer should be 20 mol% or less, preferably 10 mol% or less, and more preferably 5 mol% or less. If the content of monomers having the functional group (R1) or (R2) exceeds 20 mol%, the long-term stability of the coating composition of this embodiment may decrease. Furthermore, unreacted functional groups (R1) or (R2) may remain in the resulting coating layer, potentially causing changes in the physical properties of the coating layer, various laminates, molded articles, etc., over time.

[0028] The total content of (meth)acryloyl groups and unsaturated alicyclic hydrocarbon groups in the side chains of the acrylic polymer (A3) should be 20 mol% or less, preferably 10 mol% or less, and more preferably 5 mol% or less, based on the total content of the raw material monomers. If the total content of (meth)acryloyl groups and unsaturated alicyclic hydrocarbon groups in the side chains of A3 exceeds 20 mol%, the long-term stability of the coating composition of this embodiment may decrease, and the resulting coating layer may have too high a crosslinking density, reducing its flexibility and potentially failing to provide satisfactory adhesion and flexural resistance to resin substrates that are difficult to adhere to.

[0029] The molecular weight of the acrylic polymer (A) used in the present invention is 100,000 to 6,000,000 on a weight average. Preferably, it is 300,000 to 6,000,000, and more preferably 600,000 to 6,000,000. If the weight average molecular weight of the acrylic polymer (A) is 100,000 or more, the resulting coating composition and the coating layer formed from the composition will have excellent adhesion to general-purpose resin substrates such as polyester and polycarbonate, as well as to substrates such as fluororesin and polyimide films and sheets that are difficult to adhere to, while also having strong adhesion (also referred to as adhesion) between the coating layer and the substrate, and providing sufficient flexibility and bending resistance. Furthermore, as the molecular weight of the acrylic polymer (A) increases, when used as an adhesive coating layer, the stain resistance essential for rework operations increases, which is preferable. While it is considered that a higher weight average molecular weight of the acrylic polymer (A) is better, it is currently difficult to synthesize acrylic polymer (A) with a molecular weight exceeding 6,000,000.

[0030] The Tg of the acrylic polymer (A) used in the present invention is -85°C to 40°C. Preferably, it is -80°C to 25°C, and more preferably -70°C to 10°C. When the Tg is within the range of -85°C to 40°C, the resulting coating composition is easily applied uniformly to film or sheet-like substrates, and the coating layer formed from the composition adheres well to the substrate. As the Tg of the acrylic polymer (A) decreases, the adhesion to substrates such as fluororesin-based and polyimide-based films and sheets, which are difficult to adhere to, tends to improve.

[0031] If the acrylic polymer (A) is a copolymer, its glass transition temperature (Tg) is a value calculated based on the following known Fox equation. If the copolymer is composed of n monomer components, monomer 1, monomer 2, ..., monomer n, 1 / Tg=W1 / Tg1+W2 / Tg2+···+Wi / Tgi (In the formula, Tg is the glass transition temperature of the copolymer (unit: K), Tgi(i=1, 2, ...n) is the glass transition temperature when monomer i forms a homopolymer (unit: K), and Wi(i=1, 2, ...n) represents the weight (mass) fraction of monomer i in the total monomer components.) In this specification, "glass transition temperature when homopolymer is formed" means "glass transition temperature of the monomer homopolymer."

[0032] The polymerizable compound (B) used in the present invention contains a monofunctional acrylic monomer (b1) having only one type and one unsaturated bond in one molecule, and a polyfunctional acrylic monomer (b2) having one or more types and two or more unsaturated bonds in one molecule. The unsaturated bonds in the monofunctional acrylic monomer (b1) and the polyfunctional acrylic monomer (b2) are one or more selected from methacrylate groups, acrylate groups, methacrylamide groups, and acrylamide groups.

[0033] Preferably, the monofunctional acrylic monomer (b1) contains a monofunctional acrylic monomer with a homopolymer glass transition temperature (Tg) of 10°C or less and a monofunctional acrylic monomer with a homopolymer glass transition temperature (Tg) of 60°C or more. By combining a monofunctional acrylic monomer with a homopolymer Tg of 10°C or less and a monofunctional acrylic monomer with a homopolymer Tg of 60°C or more, the Tg of the acrylic polymer (A) can be easily adjusted to a predetermined range, improving the transparency and curability by active energy rays such as heat and light of the coating composition containing the acrylic polymer (A). This makes it easier to achieve a balance between the surface hardness (rigidity) and flexibility (flexibility) of the resulting coating layer, and makes it easier to adjust the balance between adhesion to difficult-to-adhere substrates, tack resistance, and surface hardness of the non-adhesive coating layer. It also makes it easier to adjust the balance between adhesion to difficult-to-adhere substrates, tack resistance, and stain resistance (reworkability) of the adhesive coating layer.

[0034] Examples of monofunctional acrylic monomers with a homopolymer Tg of 10°C or less include methoxydipropylene glycol acrylate (Tg=-44°C), methoxytriethylene glycol acrylate (Tg=-50°C), methoxypolyethylene glycol acrylate (average molecular weight of polyethylene glycol 400) (Tg=-71°C), methoxytripropylene glycol acrylate (Tg=-75°C), phenoxyethyl acrylate (Tg=-22°C), methyl acrylate (Tg=8°C), ethyl acrylate (Tg=-22°C), butyl acrylate (Tg=-54°C), 2-ethylhexyl acrylate (Tg=-85°C), octyl acrylate (Tg=-65°C), nonyl acrylate (Tg=-58°C), dodecyl acrylate (Tg=-3°C), isodecyl acrylate (Tg=-62°C), and isostearyl acrylate (Tg=-18°C). ), tridecyl acrylate (Tg=-75℃), 2-ethylhexyl methacrylate (Tg=-10℃), octyl methacrylate (Tg=-20℃), dodecyl methacrylate (Tg=-65℃), 2-hydroxyethyl acrylate (Tg=-15℃), 2-hydroxypropyl acrylate (Tg=-7℃), 4-hydroxybutyl acrylate (Tg=-40℃), methoxyethyl acrylate (Tg=-50℃), et Examples include oxyethyl acrylate (Tg=-50°C), methoxybutyl acrylate (Tg=-56°C), 3-methoxypropyl acrylate (Tg=-75°C), butoxyethyl acrylate (Tg=-40°C), phenoxydiethylene glycol acrylate (Tg=-25°C), dicyclopentenyloxyethyl acrylate (Tg=10°C), and tetrahydrofurfuryl acrylate (Tg=-12°C). These monofunctional acrylic monomers with a Tg of 10°C or less may be used individually or in mixtures of two or more.

[0035] Examples of monofunctional acrylic monomers with a homopolymer Tg exceeding 60°C include isobornyl acrylate (Tg=94°C), cyclohexyl methacrylate (Tg=66°C), 2-hydroxyethyl methacrylate (Tg=71°C), 4-t-butylcyclohexyl acrylate (Tg=81°C), dicyclopentenyl acrylate (Tg=120°C), dicyclopentanyl acrylate (Tg=120°C), acryloylmorpholine (Tg=145°C), N,N-dimethylacrylamide (Tg=119°C), and N,N-diethyl Examples include acrylamide (Tg=81°C), N-(2-hydroxyethyl)acrylamide (Tg=98°C), N-isopropylacrylamide (Tg=134°C), acrylamide (Tg=153°C), methacrylamide (Tg=77°C), diacetone acrylamide (Tg=77°C), N-methylacrylamide (Tg=130°C), N-methylmethacrylamide (Tg=65°C), N-ethylacrylamide (Tg=100°C), N-octylacrylamide (Tg=79°C), and acrylic acid (Tg=106°C). Monofunctional acrylic monomers with a Tg of over 60°C may be used individually or in combination of two or more.

[0036] The aforementioned polyfunctional acrylic monomer (b2) includes alkylene glycol di(meth)acrylates, polyalkylene glycol di(meth)acrylates, polyester di(meth)acrylates, polycarbonate di(meth)acrylates, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol penta(meth)acrylate. Examples include lithritol hexa(meth)acrylate, tri(meth)acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly(meth)acrylate, isocyanurate ethylene oxide-modified tri(meth)acrylate, ethylene oxide-modified dipentaerythritol penta(meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tetra(meth)acrylate, succinate-modified pentaerythritol tri(meth)acrylate, etc. These polyfunctional acrylic monomers (b2) may be used individually or in combination of two or more.

[0037] The coating composition of this embodiment contains 0.5 to 30.0% by mass of acrylic polymer (A) and 70.0 to 99.5% by mass of polymerizable compound (B). If the content of acrylic polymer (A) and polymerizable compound (B) is within these ranges, the resulting coating composition and the coating layer formed from the coating composition have good adhesion to substrates such as films and sheets, and can be suitably used for various applications. Furthermore, depending on the molecular weight of acrylic polymer (A), if the acrylic polymer (A) content is 0.5% by mass or more, even if a coating layer having a crosslinked structure is generated from the coating composition by various polymerization reactions, the adhesion to the substrate is good, and curing shrinkage is low, so the formed coating layer is difficult to peel off from the substrate and has high flexibility. Furthermore, from the viewpoint of further improving the surface hardness and scratch resistance of the resulting non-adhesive coating layer and laminate, the coating composition preferably contains 0.5 to 25.0% by mass of acrylic polymer (A) and 75.0 to 99.5% by mass of polymerizable compound (B), and more preferably contains 1.0 to 20.0% by mass of acrylic polymer (A) and 80.0 to 99.0% by mass of polymerizable compound (B). From the viewpoint of further improving the stain resistance and step-following ability of the resulting adhesive coating layer and laminate, the coating composition preferably contains 1.0 to 30.0% by mass of acrylic polymer (A) and 70.0 to 99.0% by mass of polymerizable compound (B), and more preferably contains 2.0 to 25.0% by mass of acrylic polymer (A) and 75.0 to 98.0% by mass of polymerizable compound (B).

[0038] The polymerizable compound (B) described above contains a monofunctional acrylic monomer (b1) and a polyfunctional acrylic monomer (b2). The content of the monofunctional acrylic monomer (b1) is preferably 10.0 to 95.0% by mass of the total coating composition (D). The monofunctional acrylic monomer (b1) has the effect of improving the compatibility between the acrylic polymer (A) and the polyfunctional acrylic monomer (b2). If its content is 10.0% by mass or more, the transparency of the coating composition (D) and the transparency and resistance to yellowing of the cured coat layer are good. Furthermore, if the content of the monofunctional acrylic monomer (b1) is 95.0% by mass or less, the content of the acrylic polymer (A) and the polyfunctional acrylic monomer (b2) in the coating composition (D) can be easily adjusted. If the content of the polyfunctional acrylic monomer (b2) is 80.0% by mass or less, it becomes easier to adjust the content of the acrylic polymer (A) and the monofunctional acrylic monomer (b1) in the coating composition (D) according to the purpose, and the curing shrinkage resistance and flexural resistance of the resulting coat layer are good, which is preferable.

[0039] The coating composition used for the non-adhesive coating layer and laminate preferably contains 15.0 to 80.0% by mass of monofunctional acrylic monomer (b1), and more preferably 20.0 to 60.0% by mass, from the viewpoint of further improving the adhesion and flexibility of the resulting non-adhesive coating layer and laminate. Furthermore, from the viewpoint of enabling the coating composition (D) to cure quickly and sufficiently satisfying rigid properties such as surface hardness, tack resistance, and scratch resistance of the resulting coating layer, the content of polyfunctional acrylic monomer (b2) preferably contains 2.0 to 80.0% by mass, more preferably 5.0 to 60.0% by mass, and more preferably 10.0 to 50.0% by mass.

[0040] The coating composition used in the adhesive coating layer and laminate preferably contains 30.0 to 80.0% by mass of monofunctional acrylic monomer (b1), and particularly preferably 45.0 to 70.0% by mass, from the viewpoint of further improving wettability and tackiness to the substrate. Furthermore, from the viewpoint of improving the stain resistance and heat resistance of the resulting adhesive coating layer while maintaining good tackiness, the content of polyfunctional acrylic monomer (b2) preferably contains 0.5 to 20.0% by mass, and particularly preferably 0.5 to 10.0% by mass. Moreover, from the viewpoint of sufficiently satisfying adhesion to difficult-to-adhere substrates and step-following ability, the content of polyfunctional acrylic monomer (b2) is most preferably 1.0 to 5.0% by mass or less.

[0041] The polymerizable compound (B) may further contain a urethane oligomer (b3), excluding the monofunctional acrylic monomer (b1) and polyfunctional acrylic monomer (b2) described above. The urethane oligomer (b3) is a polyfunctional urethane oligomer having one or more unsaturated bonds and urethane bonds within one molecule. The unsaturated bonds of the urethane oligomer (b3) are one or more selected from methacrylate groups, acrylate groups, methacrylamide groups, and acrylamide groups. Furthermore, when the urethane oligomer (b3) uses one or more methacrylamide groups or acrylamide groups as unsaturated bonds within the molecule, that is, when the urethane oligomer (b3) is a urethane (meth)acrylamide oligomer, the curability of the coating composition (D) is improved, and at the same time, curing shrinkage when curing the coating composition (D) by various polymerization methods is low, resulting in a coat layer with sufficient shrinkage resistance, which is preferable.

[0042] The urethane oligomer (b3) can be obtained using a known urethane reaction method with a polyol, polyisocyanate, and a (meth)acrylate and / or a (meth)acrylamide having hydroxyl groups. The urethane oligomer (b3) has one or more polyol-derived skeletons selected from ether skeletons, ester skeletons, carbonate skeletons, silicone skeletons, olefin skeletons, and acrylic skeletons, and the number of unsaturated bonds in one molecule is preferably two or more from the viewpoint of improving the curability of the coating composition (D), and is usually 10 or less, preferably 6 or less, and more preferably 4 or less from the viewpoint of achieving both rigidity and flexibility in the resulting coat layer.

[0043] The average molecular weight (Mw) of the urethane oligomer (b3) is preferably 1,500 to 100,000, and more preferably 2,000 to 50,000. If the average molecular weight (Mw) of the urethane oligomer (b3) is within this range, the wettability and adhesion of the coating composition (D) to various substrates are good, the resulting coating layer has high adhesion to a wide range of substrates, from general-purpose resin substrates to substrates that are difficult to adhere to, and the laminates, molded products, etc., formed from such a coating layer have sufficient flexibility and heat and humidity resistance.

[0044] The content of urethane oligomer (b3) is preferably 2.0 to 50.0% by mass of the total coating composition (D). When (b3) is contained at 2.0% by mass or more, improved curability of the coating composition and improved balance of rigidity and flexibility of the resulting coat layer are observed. On the other hand, if the content of (b3) exceeds 50.0% by mass, there is a risk of decreased moisture and heat resistance of the cured coat layer, the target laminate, and the molded product. Furthermore, when used in non-adhesive coat layers and laminates, from the viewpoint of further improving adhesion and bending resistance, the content of (b3) is more preferably 2.0 to 35.0% by mass, and particularly preferably 5.0 to 20.0% by mass. When used in adhesive coat layers and laminates, from the viewpoint of further improving tackiness (adhesion) and stain resistance, the content is more preferably 5.0 to 50.0% by mass, and particularly preferably 10.0 to 30.0% by mass.

[0045] The coating composition (D) can be polymerized by thermal polymerization, photopolymerization, or hybrid polymerization. In the case of thermal polymerization, it is preferable to use a thermal polymerization initiator. In the case of polymerization using active energy rays such as light (photopolymerization), if an electron beam is used as the active energy ray, it is not necessary to use a photopolymerization initiator, but if ultraviolet rays or visible rays are used, it is preferable to use a photopolymerization initiator. In the case of hybrid polymerization, a thermal polymerization initiator and a photopolymerization initiator may be used in combination. If (A1) has an active hydrogen-containing functional group (R1) and (A2) has a functional group (R2) in its side chain that reacts with the active hydrogen-containing functional group (R1), the polymerizable compound (B) may be polymerized with a photopolymerization initiator, and then the reaction of functional groups R1 and R2 may be carried out by heating. Also, if (A3) has a (meth)acryloyl group or an unsaturated alicyclic hydrocarbon group in its side chain, it may be copolymerized with the polymerizable compound (B) with a photopolymerization initiator, or the polymerizable compound (B) may be photopolymerized, and then (A3) may be polymerized with a thermal polymerization initiator.

[0046] As thermal polymerization initiators, you can appropriately select from commonly used ones such as azo initiators, peroxide initiators, persulfate initiators, and redox initiators. For example, azo initiators include VA-044, VA-46B, V-50, VA-057, VA-061, VA-067, VA-086, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (VAZO 33), 2,2'-azobis(2-amidinopropane) dihydrochloride (VAZO 50), 2,2'-azobis(isobutyronitrile) (VAZO 64), 2,2'-azobis-2-methylbutyronitrile (VAZO 67), and 1,1-azobis(1-cyclohexanecarbonitride) (VAZO 88) (all from DuPont). Examples include 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(methylisobutyrate) (V-601), and 2,2'-azobis(2,4-dimethylvaleronitrile) (V-65) (available from Wako Pure Chemical Industries, Ltd.). Examples of peroxide initiators include benzoyl peroxide, acetyl peroxide, lauroyl peroxide, decanoyl peroxide, dicetyl peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate (Perkadox 16S) (available from Akzo Nobel), di(2-ethylhexyl)peroxydicarbonate, t-butyl peroxypivalate (Lupersol 11) (available from Elf Atochem), t-butyl peroxy-2-ethylhexanoate (Trigonox 21-C50) (available from Akzo Nobel), and dicumyl peroxide. Examples of persulfate initiators include potassium persulfate, sodium persulfate, and ammonium persulfate. Examples of redox initiators include combinations of the persulfate initiator with reducing agents such as sodium metabisulfite and sodium bisulfite, systems based on organic peroxides and tertiary amines (for example, systems based on benzoyl peroxide and dimethylaniline), and systems based on organic hydroperoxides and transition metals (for example, systems based on cumene hydroperoxide and cobalt naphthate).These thermal polymerization initiators can be used individually or in combination of two or more.

[0047] The content of the thermal polymerization initiator is preferably 0.1 to 10% by mass relative to the total coating composition (D). More preferably 0.5 to 5% by mass, and particularly preferably 1.0 to 3% by mass.

[0048] As a photopolymerization initiator, one can be appropriately selected from commonly used ones such as acetophenone-based, benzoin-based, α-aminoketone-based, xanthone-based, anthraquinone-based, acylphosphine oxide-based, and polymer photopolymerization initiators. For example, acetophenones include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, 4-(2-hydroxyethoxy)-phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1; benzoins include benzoin, α-methylbenzoin, α-phenylbenzoin, α-allylbenzoin, α-benzoylbenzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyldimethyl ketal; and benzophenones include benzophenone, benzoylbenzoic acid, benzoyl benzoic acid Examples of methyl acetates and α-aminoketones include 2-methyl-1-(4-methylthiophenyl)-2-(4-morpholinyl)-1-propanone, 2-benzyl-2-(dimethylamino)-1-(4-(4-morpholinyl)phenyl)-1-butanone, and 2-(dimethylamino)-2-(4-methylphenyl)methyl-1-(4-(4-morpholinyl)phenyl)-1-butanone. Examples of xanthones include xanthones, thioxanthones, and anthraquinones. Examples of photopolymerization initiators include anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, acylphosphine oxides such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and polymer photopolymerization initiators such as 2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propan-1-one polymer. These photopolymerization initiators can be used individually or in combination of two or more.

[0049] The photopolymerization initiator content is preferably 0.01 to 10% by mass relative to the total coating composition (D). More preferably 0.1 to 5% by mass, and particularly preferably 0.5 to 3% by mass.

[0050] The coating composition (D) does not need to contain a solvent, but solvents and various additives may be added as needed. The solvent is not particularly limited as long as it can be mixed with the coating composition (D) to obtain a clear and homogeneous solution and does not react with any of the components of the coating composition (D). Examples include aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as hexane, heptane, octane, decane, and cyclohexane; esters such as ethyl acetate, butyl acetate, and 2-hydroxyethyl acetate; aliphatic alcohols such as ethyl alcohol, n-propyl alcohol, and isopropyl alcohol; glycols such as ethylene glycol, propylene glycol, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide; and acetonitrile. These solvents may be used individually or in combination of two or more. Furthermore, from the viewpoint of applying the coating composition (D) to the substrate, removing the solvent, and then performing polymerization and curing, it is preferable to use low-boiling point solvents such as ethyl acetate, methyl ethyl ketone, and acetone, which are easy to remove.

[0051] The coating composition (D) may contain various additives as needed. Specifically, additives that can be added include thermal polymerization inhibitors, antioxidants, UV sensitizers, preservatives, phosphate esters and other flame retardants, surfactants, antistatic agents, pigments, dyes and other colorants, fragrances, defoamers, fillers, silane coupling agents, surface tension modifiers, plasticizers, surface lubricants, leveling agents, softeners, organic fillers, inorganic fillers, silica particles, etc. The amount of these other components added is not particularly limited as long as it does not adversely affect the properties of the coating composition (D), but it is preferable that it be in the range of 5% by mass or less of the total coating composition (D).

[0052] A third embodiment of the present invention relates to a laminate, a surface protection sheet such as a cover film, and a molded product such as a substrate, which have a coated layer obtained by applying the coating composition (D) to various substrates and curing it by various polymerization methods. The film used as the substrate is one of the films selected from polyester film, polycarbonate film, fluororesin film, polyimide film, triacetylcellulose film, acrylic film, polystyrene film, polyvinyl chloride film, polyvinyl alcohol film, and nylon film. The transparent substrate film is one of the transparent films selected from transparent polyester film, transparent polycarbonate film, transparent fluororesin film, transparent polyimide film, transparent triacetylcellulose film, transparent acrylic film, transparent polystyrene film, transparent polyvinyl chloride film, transparent polyvinyl alcohol film, and transparent nylon film, and is a film with a total light transmittance of 80% or more. The coating composition (D) can be applied to one or both sides of various substrate films, polymerized and cured by various polymerization methods to obtain a laminate, etc., having a coated layer on one or both sides of the substrate. The coating composition (D) can be applied using conventionally known methods, such as spin coating, spray coating, knife coating, dipping, gravure roll, reverse roll, screen printing, and bar coater. [Examples]

[0053] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Also, in the following, "parts" and "%" all refer to mass unless otherwise specified.

[0054] The abbreviations for the acrylic polymer (A), polymerizable compound (B), initiator (C), and various substrates (E) described in the examples and comparative examples are as follows: <Acrylic polymer (A)> A-1: Homopolymer of 2-ethylhexyl acrylate (b1-3), weight-average molecular weight (Mw) of 5.6 million, Tg = -85℃ A-2: Copolymer of 2-ethylhexyl acrylate (b1-3), butyl acrylate (b1-4), and N,N-dimethylacrylamide (b1-8) (molar ratio = 70 / 10 / 20), Mw = 2.2 million, Tg = -69°C A-3: Copolymer of butyl acrylate (b1-4) and N-isopropylacrylamide (b1-14) (molar ratio = 70 / 30), Mw = 600,000, Tg = -22℃ A-4: Copolymer of ethyl acrylate (Tg=-20℃), isobutyl methacrylate (b1-1), and diacetone acrylamide (b1-13) (molar ratio=30 / 50 / 20), Mw=120,000, Tg=35℃ A-5: Copolymer of 2-ethylhexyl acrylate (b1-3) and oleylacrylamide (b1-16) (molar ratio = 80 / 20), Mw = 900,000, Tg = -60°C A-6: Copolymer of 2-ethylhexyl acrylate (b1-3) and allyl methacrylate (Tg=52℃) (molar ratio=90 / 10), Mw=850,000, Tg=-79℃ A1-1: Copolymer of 2-ethylhexyl acrylate (b1-3), N,N-diethylacrylamide (b1-9), and N-(2-hydroxyethyl)acrylamide (b1-10) (molar ratio = 60 / 35 / 5), Mw = 1.1 million, Tg = -52℃ A1-2: Copolymer of isobutyl acrylate (Tg -26℃) and acrylic acid (b1-17) (molar ratio = 95 / 5), Mw = 2.8 million, Tg = -24℃ A2-1: Copolymer of isodecyl acrylate (b1-5), isobornyl acrylate (b1-11), and glycidyl methacrylate (b1-19) (molar ratio = 70 / 28 / 2), Mw = 330,000, Tg = -29℃ A2-2: 2-ethylhexyl acrylate (b1-3), acryloylmorpholine (b1-12), 2-isocyanatoethyl methacrylate (b1-18) (molar ratio = 80 / 17 / 3), Mw = 730,000, Tg = -67℃ A3-1: A copolymer of isodecyl acrylate (b1-5), acryloylmorpholine (b1-12), and acrylic acid (b1-17) (molar ratio = 50 / 10 / 20), to which glycidyl methacrylate (molar ratio = 20) is added. Mw = 180,000, Tg = 22℃ A3-2: Copolymer of 2-ethylhexyl acrylate (b1-3), oleyl acrylamide (b1-16), isobornyl acrylate (b1-11), and N-acryloyloxyethyl norbornene carboxamide (registered trademark "Kohshylmer," manufactured by KJ Chemicals Co., Ltd.) (molar ratio = 25 / 25 / 40 / 10), Mw = 240,000, Tg = 8℃ <Polymerizable compound (B)> b1-1: Isobutyl methacrylate (Tg=48℃) b1-2: Cyclohexyl acrylate (Tg=15℃) b1-3: 2-ethylhexyl acrylate (Tg=-85℃) b1-4: Butyl acrylate (Tg=-54℃) b1-5: Isodecyl acrylate (Tg=-62℃) b1-6: Phenoxyethyl acrylate (Tg=-22℃) b1-7: Dicyclopentenyloxyethyl acrylate (Tg=10℃) b1-8: N,N-dimethylacrylamide (Tg=119℃) (Registered trademarks "Kohshylmer" and "DMAA", manufactured by KJ Chemicals Co., Ltd.) b1-9: N,N-Diethylacrylamide (Tg=81℃) (Registered trademarks "Kohshylmer" and "DEAA", manufactured by KJ Chemicals Co., Ltd.) b1-10: N-(2-hydroxyethyl)acrylamide (Tg=98℃) (Registered trademarks "Kohshylmer" and "HEAA", manufactured by KJ Chemicals Co., Ltd.) b1-11: Isobornyl acrylate (Tg=94℃) b1-12: Acryloylmorpholine (Tg=145℃) (Registered trademarks "Kohshylmer" and "ACMO", manufactured by KJ Chemicals Co., Ltd.) b1-13: Diacetone acrylamide (Tg=77℃) (Registered trademark "Kohshylmer", manufactured by KJ Chemicals Co., Ltd.) b1-14: N-isopropylacrylamide (Tg=134℃) (Registered trademarks "Kohshylmer" and "NIPAM", manufactured by KJ Chemicals Co., Ltd.) b1-15: 4-tert-butylcyclohexyl acrylate (Tg=77℃) (Registered trademark "Kohshylmer", manufactured by KJ Chemicals Co., Ltd.) b1-16: Oleylacrylamide (Tg=29℃) (Registered trademark "Kohshylmer", manufactured by KJ Chemicals Co., Ltd.) b1-17: Acrylic acid (Tg=106℃) b1-18: 2-Isocyanatoethyl methacrylate (Tg=60℃) (Kalenz MOI, manufactured by Showa Denko Corporation) b1-19: Glycidyl methacrylate (Tg=46℃) b2-1: Pentaerythritol (tri / tetra)acrylate (3-4 functional) b2-2: Dipentaerythritol hexaacrylate (6-functional) b2-3: Bisphenol A ethylene glycol (4) adduct diacrylate (bifunctional, light acrylate BP-4EAL, Kyoeisha Chemical Co., Ltd.) b2-4: Tripropylene glycol diacrylate (bifunctional) b3-1: Polyester-based urethane acrylate (bifunctional, UV-3000B, molecular weight Mw=18000, manufactured by Mitsubishi Chemical Corporation) b3-2: Polyether-based urethane acrylate (bifunctional, Shiko UV-6640B, molecular weight Mw=5000, manufactured by Mitsubishi Chemical Corporation) b3-3: Polycarbonate-based urethane acrylamide (registered trademark "Quick Cure", bifunctional, molecular weight Mw=15000, manufactured by KJ Chemicals Co., Ltd.) b3-4: Polyester-based urethane acrylamide (registered trademark "Quick Cure", trifunctional, molecular weight Mw=9000, manufactured by KJ Chemicals Co., Ltd.) b3-5: Polyether-based urethane acrylamide (registered trademark "Quick Cure", bifunctional, molecular weight Mw=35000, manufactured by KJ Chemicals Co., Ltd.) <Initiator (C)> C-1:1-Hydroxycyclohexylphenyl ketone (Photopolymerization initiator Omnirad 184, manufactured by IGM Resins B.V.) C-2: 2-Hydroxy-2-methyl-1-phenylpropan-1-one (Photopolymerization initiator Omnirad 1173, manufactured by IGM Resins B.V.) C-3: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (photopolymerization initiator Omnirad TPO, manufactured by IGM Resins B.V.) C-4: 2,2'-Azobis(2,4-dimethylvaleronitrile) (thermal polymerization initiator V-65) (manufactured by Wako Pure Chemical Industries, Ltd.) <Film-like substrate> E-1: Polyethylene terephthalate (PET) film (Cosmoshine A4300, single-sided anchor coating, manufactured by Toyobo Co., Ltd.) E-2: Polycarbonate film (Panlight PC-2151, manufactured by Teijin Corporation) E-3: Polyimide film (Kapton, manufactured by Toray DuPont) E-4: Transparent polyimide film (TORMEND™, manufactured by IST Corporation) E-5: Transparent acrylic film (Sanduren SD-014, manufactured by Kaneka Corporation)

[0055] Examples 1-24 and Comparative Examples 1-8 Acrylic polymer (A), polymerizable compound (B), initiator (C), etc. were added to a container in predetermined mass parts as shown in Tables 1 to 3 and mixed uniformly to prepare coating compositions (D-1) to (D-24) of Examples 1 to 24 and mixed solutions (F-1) to (F-8) of Comparative Examples 1 to 8. Subsequently, using the obtained coating compositions of the examples and mixed solutions of the comparative examples, a non-stick coating layer and a sticky coating layer (sticky layer) were produced as cured films by heating and / or ultraviolet (UV) irradiation using the following method, and the resulting film laminates equipped with these coating layers were prepared and evaluated. The polymer used in Comparative Example 3 was a homopolymer of butyl acrylate (b1-4) (P-1, molecular weight Mw=100,000, Tg=-54℃), and the polymer used in Comparative Example 7 was a copolymer of butyl acrylate (b1-4) and acrylic acid (b1-17) (P-2, molar ratio=90 / 10, molecular weight Mw=150,000, Tg=-44℃).

[0056] [Table 1]

[0057] [Table 2]

[0058] [Table 3]

[0059] <Fabrication and evaluation of non-adhesive coating layers> Examples 25-40 used the prepared coating compositions (D-1)-(D-16), and Comparative Examples 9-12 used the prepared mixed solutions (F-1)-(F-4). Using a desktop coating machine (Coater TC-1, manufactured by Mitsui Electric Seiki Co., Ltd.), the coating was applied to the anchor-coated surface of a 100 μm thick polyethylene terephthalate (PET) film ("Cosmoshine A4100," manufactured by Toyobo Co., Ltd., with one side anchor-coated) using a bar coater (RDS, Inc., #6) to obtain an uncured coating film. In Examples 25 and Comparative Example 9, the uncured coating film was aged in an 80°C constant temperature bath for 5 hours to obtain a cured coating layer. In Examples 26-40 and Comparative Examples 10-12, the uncured coating film was aged using ultraviolet light (illuminance 700 mW / cm²). 2 , cumulative light intensity 1000 mJ / cm 2 The coating layers were obtained as cured films by irradiation with ultraviolet light (device: I-Graphics inverter-type conveyor device ECS-4011GX, metal halide lamp: I-Graphics M04-L41). In Examples 31-34 and 39, which used coating compositions (D-7)-(D-10) and (D-15) using acrylic polymer (A) having a functional group (R1) containing active hydrogen in its side chain (A1), or (A2) having a functional group (R2) that reacts with the functional group (R1) containing active hydrogen in its side chain (A2), the coating layers for evaluation were further aged for 3 days in a constant temperature bath at 40°C after ultraviolet irradiation. The curability of the obtained coating compositions, the surface hardness of the non-stick coating layer, tack resistance, scratch resistance, shrinkage resistance, and humid heat resistance were measured according to the following methods. The evaluation results are shown in Table 4.

[0060] <Curing properties of coating composition (D) and mixture (F)> Peaks derived from vinyl groups in the coating composition (1620-1640 cm) -1 The height of the coating was measured using FT-IR, and the curing rate was calculated as follows to evaluate the curability of the coating composition. Curing rate (%) = (Vinyl group-derived peak height before curing - Vinyl group-derived peak height after curing) / Vinyl group-derived peak height before curing × 100%). ◎: Curing rate 90% or more ○: Hardening rate 80% or more but less than 90% ×: Hardening rate less than 80%

[0061] <Shrinkage resistance of non-adhesive coating layer> A non-stick coating layer was prepared in the same manner as described above, except that the thickness of the non-stick coating layer was set to 50 μm, and the resulting cured coating layer was measured in 10 × 10 cm². 2 The paper was cut out, and the height of the lift at each of the four corners was measured. The average value was calculated from the measurements of five similarly cut pieces. ◎: The floating height is less than 0.5 mm. ○: The floating height is 0.5 mm or more and less than 1 mm. ×: The height of the float is 1 mm or more.

[0062] <Tack resistance of the non-adhesive coating layer> A cured non-adhesive coating layer with a thickness of 10 μm was prepared in the same manner as described above. The tack resistance of the non-adhesive coating layer was evaluated by touching the surface of the coating layer with a finger and observing the degree of stickiness. ◎: Not sticky at all. ○: It is slightly sticky, but no fingerprints are left on the surface. △: It is sticky and leaves fingerprints on the surface. ×: It's extremely sticky, and your fingers stick to the surface.

[0063] <Scratch resistance of non-adhesive coating layer> Similarly to the above, a cured non-stick coating layer with a thickness of 10 μm was prepared, and 100 g / cm³ of #0000 steel wool was used. 2 The load was applied and the device was moved back and forth 10 times, and the presence or absence of damage was visually evaluated. ◎: Almost no peeling or damage to the film is observed. ○: A small, fine scratch is visible on a part of the membrane. △: Linear scratches are observed across the entire surface of the membrane. ×: Delamination of the film occurs.

[0064] <Surface hardness of the non-stick coating layer> Similarly to the above, a hardened non-stick coating layer with a thickness of 10 μm was prepared, and in accordance with JIS K 5600-5-4, the hardest pencil that did not scratch the surface of the non-stick coating layer when scratched with a pencil at a 45° angle for approximately 10 mm was defined as the pencil hardness. ◎: Pencil hardness of 3H or higher ○:Pencil hardness H~2H △: Pencil hardness B~F ×: Pencil hardness 2B or lower

[0065] <Heat and moisture resistance of the non-adhesive coating layer> As described above, a cured non-adhesive coating layer with a thickness of 10 μm was prepared and held for 100 hours under conditions of 85°C and 85% relative humidity. The presence or absence of bubbles or clouding was observed visually, and the evaluation was performed as follows. ◎: Transparent and does not produce bubbles. ○: There is a very slight cloudiness, but no air bubbles are formed. ×: Foam or bubbles may form.

[0066] <Fabrication and evaluation of film laminates with a non-adhesive coating layer> Polyethylene terephthalate (PET) film (E-1), polycarbonate (PC) film (E-2), polyimide (PI) film (E-3), transparent polyimide film (E-4), and acrylic film (E-5) were used as substrates for fabricating non-adhesive coating layers. A non-adhesive coating layer with a thickness of 10 μm was fabricated on one side of each film using the same method as described above. The substrate films equipped with the obtained non-adhesive coating layers were used to form various film laminates, and the adhesion between the coating layer and the substrate film, as well as the flexibility and transparency of the film laminate, were evaluated according to the method described below. The results are shown in Table 4.

[0067] <Adhesion of film laminates with a non-adhesive coating layer> Using the resulting film laminate, a 1×1mm sheet was prepared in accordance with JIS K 5600-5-6. 2The coated layer was cut into 100 grids, and cellophane tape was applied to the surface to ensure close contact. After the cellophane tape was peeled off in one swift motion, the number of grid squares on the base film where the coated layer remained was counted, and the results were evaluated as follows. The results are shown in Table 4. ◎: 100 squares of the court layer remain. ○: Court layers of 90-99 squares remain △: Court layers of 60-89 squares remain ×: Court layers with fewer than 60 squares remain.

[0068] <Flexural resistance of film laminates with a non-adhesive coating layer> The obtained film laminate was cut into 15 mm wide x 100 mm long test pieces. In accordance with JIS P8115, a bending test was performed 20,000 times using an MIT-type bending fatigue testing machine (Toyo Seiki Seisakusho Co., Ltd., Type D) with a load of 0.25 kgf applied to the test piece, under the conditions of a bending clamp radius R of 2.0 mm, a bending angle of 135°, and a speed of 175 cpm. After the test, the presence or absence of peeling of the coating layer, cracks, or clouding was observed visually and evaluated as follows. The results are shown in Table 4. ◎: Transparent and does not peel or crack. ○: There is a very slight cloudiness, but no peeling or cracking occurs. △: Slight clouding, peeling, or cracking may occur. ×: Clouding, peeling, or cracking may occur.

[0069] <Transparency of film laminates with a non-adhesive coating layer> The resulting film laminate is 100 mm 2 The test specimens were cut and left for 24 hours in an environment of 23°C and 50% relative humidity. Under the same conditions, the total light transmittance of the uncolored film laminate was measured in accordance with JIS K 7361-1, and the evaluation was performed as follows. The results are shown in Table 4. Note that since the polyimide film (E-3) is yellow, transparency evaluation was not performed on its film laminate. ◎: Transmittance is 90% or higher ○: Transmittance is 80% or higher and less than 90%. ×: Transmittance is less than 80%

[0070]

Table 4

[0071] <Preparation and Evaluation of Adhesive Coat Layer> Examples 41 to 48 and Comparative Examples 13 to 16 In Examples 41 to 48, the prepared coating compositions (D-17) to (D-24) were used, and in Comparative Examples 13 to 16, the prepared mixed solutions (F-5) to (F-8) were used. Using a tabletop coater (coater TC-1, manufactured by Mitsui Electric Precision Co., Ltd.), a polyethylene terephthalate (PET) film with a thickness of 100 μm (「Cosmo Shine A4100」, manufactured by Toyobo Co., Ltd., one-sided anchor coat treatment) was coated on the anchor coat surface with a bar coater (RDS 30) to a thickness of 50 μm. Then, a 50-μm-thick lightly peelable PET film (manufactured by Toyobo Co., Ltd., polyester film E7002) was overlaid on the coating film, and ultraviolet rays (device: Inverter type conveyor device ECS-4011GX manufactured by Eye Graphics Co., Ltd., metal halide lamp: M04-L41 manufactured by Eye Graphics Co., Ltd., ultraviolet rays (irradiance 700 mW / cm 2 , integrated light quantity 1000 mJ / cm 2 ) irradiation was performed. Then, after removing the lightly peelable PET film, an adhesive coat layer was obtained as a cured film. In the case of Examples 44 to 46 and 48 using the coating compositions (D-20) to (D-22), (D-24) using the acrylic polymer (A) having a functional group (R1) containing active hydrogen in the side chain or (A2) having a functional group (R2) reacting with the functional group (R1) containing active hydrogen in the side chain, after ultraviolet irradiation, aging was further performed in a constant temperature bath at 40 °C for 3 days. Then, after removing the lightly peelable PET film, an adhesive coat layer for evaluation was obtained. The curability of the obtained coating composition, the shrinkage resistance, the humidity and heat resistance, and the step following property of the adhesive coat layer were measured according to the following methods. The evaluation results are shown in Table 5.

[0072] <Curability of Coating Composition (D) and Mixed Solution (F)> Peaks derived from vinyl groups in the coating composition (1620-1640 cm) -1 The height of the coating was measured using FT-IR, and the curing rate was calculated as follows to evaluate the curability of the coating composition. Curing rate (%) = (Vinyl group-derived peak height before curing - Vinyl group-derived peak height after curing) / Vinyl group-derived peak height before curing × 100%). ◎: Curing rate 90% or more ○: Hardening rate 80% or more but less than 90% ×: Hardening rate less than 80%

[0073] <Shrinkage resistance of the adhesive coating layer> A cured adhesive coating layer was prepared in the same manner as described above, except that the thickness of the adhesive coating layer was set to 100 μm, and a 10 × 10 cm 2 The paper was cut out, and the height of the lift at each of the four corners was measured. The average value was calculated from the measurements of five similarly cut pieces. ◎: The floating height is less than 0.5 mm. ○: The floating height is 0.5 mm or more and less than 1 mm. ×: The height of the float is 1 mm or more.

[0074] <Heat and moisture resistance of the adhesive coating layer> As described above, a cured adhesive coating layer with a thickness of 50 μm was prepared and held for 100 hours under conditions of 85°C and 85% relative humidity. The presence or absence of bubbles or clouding was observed visually, and the evaluation was performed as follows. ◎: Transparent and does not produce bubbles. ○: There is a very slight cloudiness, but no air bubbles are formed. ×: Foam or bubbles may form.

[0075] <Step-following ability of adhesive coating layer> A stepped glass surface was fabricated by laminating a 20 μm thick black tape onto a polyimide substrate. An adhesive coating layer was transferred to the stepped glass surface and pressed down once with a 2 kg load roller (pressure speed 300 mm / min) in an atmosphere of 23°C and 50% relative humidity. After being left at 80°C for 24 hours, the condition of the stepped surface was examined with an optical microscope and evaluated in four stages as described below. The results are shown in Table 5. ◎: No bubbles are visible at all. ○: A few small, spherical bubbles are visible. △: Large bubbles are visible, and in some cases, the bubbles are connected to each other. ×: Large bubbles are connected to each other and spread out in a linear fashion at the step.

[0076] <Stain resistance of the adhesive coating layer> Similarly to the above, a cured adhesive coating layer with a thickness of 50 μm was prepared. The light-release PET film was peeled off, and the adhesive coating layer was transferred to one side of the base films (E-1) to (E-5). The films were then pressed and attached using a 2 kg pressure roller by making two passes back and forth, and left at 80°C for 24 hours. After that, the films (E-1) to (E-5) were peeled off, and the condition of the adhesive coating layer remaining on the film surface was visually observed. The stain resistance was evaluated in four stages as described below. The results are shown in Table 5. ◎: No contamination. ○: There is a very slight contamination. △: Slight contamination present. ×: There is adhesive residue.

[0077] <Fabrication and evaluation of film laminates with an adhesive coating layer> Similarly to the above, a cured adhesive coating layer with a thickness of 50 μm was prepared, the light-release PET film was peeled off, and the adhesive coating layer was transferred to one side of the base films (E-1) to (E-5). The films were then pressed and attached using a 2 kg pressure roller by two passes, yielding various film laminates. The tackiness (adhesion strength), transparency, and resistance to yellowing of the adhesive coating layer were evaluated according to the method described below. The results are shown in Table 5.

[0078] <Adhesion of the adhesive coating layer of a film laminate> Using film laminates left for 30 minutes in an environment of 23°C and 50% relative humidity, a 180° peel test was performed on the adhesive coating layer and various film substrates in accordance with JIS Z 0237:2009 at a peeling speed of 5 mm / sec. The peel strength was measured and evaluated as follows. The results are shown in Table 5. ◎: 8N / cm or more ○: 4N / cm or more and less than 8N / cm △: 2N / cm or more and less than 4N / cm ×: Less than 2N / cm

[0079] <Transparency of film laminates with an adhesive coating layer> The resulting film laminate is 100 mm 2 The test specimens were cut and left for 24 hours in an environment of 23°C and 50% relative humidity. Under the same conditions, the total light transmittance of the uncolored film laminate was measured in accordance with JIS K 7361-1, and the evaluation was performed as follows. The results are shown in Table 5. Note that since film E-3 is yellow, the transparency of its film laminate was not evaluated. ◎: Transmittance is 90% or higher ○: Transmittance is 80% or higher and less than 90%. ×: Transmittance is less than 80%

[0080] <Resistance to yellowing of film laminates with an adhesive coating layer> The resulting uncolored film laminate was placed in a xenon fade meter (SC-700-WA: manufactured by Suga Test Instruments Co., Ltd.) and measured at 70 mW / cm². 2 After irradiating the film laminate with ultraviolet light of the specified intensity for 120 hours, the discoloration was visually evaluated in four stages as described below. The results are shown in Table 5. Note that since film E-3 is yellow, its resistance to yellowing was not evaluated. ◎: No yellowing is visible to the naked eye. ○: Very slight yellowing can be observed with the naked eye. △: Yellowing is visible to the naked eye. ×: Obvious yellowing is visible to the naked eye.

[0081] [Table 5]

[0082] As shown in the results of the examples and comparative examples, the coating composition of the first embodiment of the present invention contains a specific acrylate polymer (A) and a polymerizable compound (B) in a specific mass ratio, resulting in high polymerizability and curability by active energy rays such as heat and / or light, and good wettability and adhesion to various substrates. The non-adhesive coating layer formed from this coating composition, which is one of the second embodiments of the present invention, exhibits high surface hardness, tack resistance, scratch resistance, shrinkage resistance, and heat and humidity resistance. In various laminates equipped with this non-adhesive coating layer and one of the third embodiments of the present invention, the non-adhesive coating layer exhibits excellent adhesion to a wide range of resin substrates, from general-purpose polyester films and polycarbonate films to polyimide films that are difficult to adhere to, and it is clear that the resulting film laminates have flexibility and transparency. Furthermore, the adhesive coating layer, which is another embodiment of the present invention formed from the coating composition, exhibits high shrinkage resistance and heat and humidity resistance. In various laminates, which is another embodiment of the present invention equipped with this adhesive coating layer, the adhesive coating layer exhibits excellent adhesion and tackiness to a wide range of resin substrates, from general-purpose polyester films and polycarbonate films to polyimide films that are difficult to adhere to, and it is clear that it also possesses transparency, stain resistance, and resistance to yellowing. Film laminates, cover films, and substrates having such non-adhesive coating layers can achieve both surface hardness and flexibility, while film laminates having an adhesive coating layer exhibit excellent adhesion to polyimide films and the like, as well as properties such as shrinkage resistance, heat and humidity resistance, and step-following ability, making them suitable for use in various optical and electronic devices. [Industrial applicability]

[0083] As described above, the coating composition of the present invention contains 0.5 to 30.0% by mass of an acrylic polymer (A) having branched alkyl groups and / or branched or unbranched alkenyl groups with 3 to 20 carbon atoms in its side chains, and 70.0 to 99.5% by mass of a polymerizable compound (B). Polymerization and curing by active energy rays such as heat and / or light yield the desired non-stick or adhesive coating layer. By applying this coating layer to one or both sides of a resin substrate, such as a film, sheet, or substrate, the desired laminate, cover film, or substrate can be obtained. By using the coating composition of the present invention, a non-adhesive coating layer can be obtained that has excellent wettability and adhesion to a resin substrate, while also possessing good surface hardness, tack resistance, scratch resistance, shrinkage resistance, flexibility resistance, transparency, and moisture and heat resistance. Additionally, an adhesive coating layer can be obtained that has excellent adhesion, along with good shrinkage resistance, moisture and heat resistance, step-following ability, stain resistance, transparency, and yellowing resistance. These can be used as various optical components, such as optical films, with the non-adhesive coating layer on one and / or both sides of the aforementioned resin substrates. Furthermore, the adhesive coating layer can be used to bond various optical films, resulting in various laminated films. These various optical films can be suitably used as materials for electronic devices such as various displays and touch panel components, liquid crystal displays and organic electroluminescent displays, and various sensor materials.

Claims

1. It contains 0.5 to 30.0% by mass of acrylic polymer (A) and 70.0 to 99.5% by mass of polymerizable compound (B), The acrylic polymer (A) has a branched alkyl group having 3 to 20 carbon atoms and / or a branched or unbranched alkenyl group in its side chain. The polymerizable compound (B) is a coating composition containing a (meth)acrylamide monomer and a urethane oligomer.

2. The coating composition according to claim 1, characterized in that the acrylic polymer (A) is an acrylic polymer having a weight-average molecular weight of 100,000 to 6,000,000 and a glass transition temperature (Tg) of -85°C to 40°C.

3. The coating composition according to claim 1 or 2, characterized in that the acrylic polymer (A) further has a functional group (R1) containing active hydrogen in its side chain (A1), or a functional group (R2) that reacts with the functional group (R1) containing active hydrogen in its side chain (A2), and / or further has a (meth)acryloyl group or an unsaturated alicyclic hydrocarbon group in its side chain (A3).

4. The coating composition according to any one of claims 1 to 3, characterized in that the polymerizable compound (B) contains a monofunctional acrylic monomer (b1) and a polyfunctional acrylic monomer (b2), and the content of (b1) is 10.0 to 96.0% by mass of the total coating composition, and the content of (b2) is 0 to 80.0% by mass of the total coating composition.

5. The coating composition according to any one of claims 1 to 4, characterized in that the content of the urethane oligomer (b3) (excluding b1 and b2) is 2.0 to 50.0% by mass of the total coating composition.

6. The coating composition according to claim 5, characterized in that the urethane oligomer (b3) is a urethane (meth)acrylamide oligomer.

7. A non-stick coating layer obtained by polymerizing the coating composition according to any one of claims 1 to 6 with light and / or heat.

8. An adhesive coating layer obtained by polymerizing the coating composition according to any one of claims 1 to 6 with light and / or heat.

9. An adhesive sheet comprising a coating layer according to claim 7 or 8 on one or both sides of a film-like and / or sheet-like substrate.

10. A laminate comprising a coating layer according to claim 7 or 8 on one or both sides of a film-like and / or sheet-like substrate.

11. An optical laminate comprising a coating layer according to claim 7 or 8 on one or both sides of a film-like and / or sheet-like substrate, wherein the total light transmittance is 80% or more.

12. A laminate for a flexible device comprising a coating layer according to claim 7 or 8 on one or both sides of a film-like and / or sheet-like substrate.

13. A surface protection laminate comprising a coating layer according to claim 7 or 8 on one or both sides of a film-like and / or sheet-like substrate.

14. A display laminate comprising a coating layer according to claim 7 or 8 on one or both sides of a film-like and / or sheet-like substrate.

15. The laminate according to any one of claims 10 to 14, characterized in that the film-like substrate is one film selected from polyester film, polycarbonate film, fluororesin film, polyimide film, triacetylcellulose film, acrylic film, polystyrene film, polyvinyl chloride film, polyvinyl alcohol film, and nylon film.

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