Laminate and decorative film including laminate

Abstract

To provide a laminate which has such transparency as not to impair designability of a coated material itself, and has good touch feeling on the surface, and a decorative film having the same.SOLUTION: A laminate has a coating layer containing a polyurethane resin and particles on the outermost surface, and has a base material, wherein hardness of the particles is 0.1 MPa to 800 MPa, and a composite elastic modulus thereof is 0.01 GPa to 10 GPa, and a haze of the laminate is 78% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a laminate that can be used as a decorative sheet or the like that is pleasant to the touch. [Background technology]

[0002] With the development of autonomous driving control technology for four-wheeled vehicles progressing, it is said that the arrival of cars that can drive automatically without a human operating the steering wheel, once the desired location is input, is imminent. As a result, the interior space of a car will place emphasis on comfort rather than operability, and it is said that it will become a comfortable living space, like a mobile living room. To create a living room, it is necessary to improve the aesthetics and tactile feel of the surfaces of automobile interior parts such as instrument panels and airbag covers.

[0003] Automotive interior parts are mainly made by molding plastics, but because the surface of these molded bodies is hard, in order to improve the aesthetics and tactile feel of the surface, the surface of the molded body has traditionally been covered with a covering sheet made of resin containing particles, for example.

[0004] One such covering sheet is a peach skin-like decorative sheet characterized in that "on the surface of the decorative sheet body, a first surface protective layer with an average thickness of 3 to 10 μm formed from a resin composition containing a gloss-adjusting matting agent with an average particle size of 0.1 to 3 μm, and a second surface protective layer formed from a resin composition containing synthetic resin beads with an average particle size of 10 to 30 μm are formed in this order, and the average thickness of the portion excluding the synthetic resin beads protruding from the surface of the second surface protective layer is 3 to 6 μm," which is proposed to eliminate the cold feel (plastic feel) common in conventional plastic decorative sheets and to provide a smooth, warm feel similar to that of solid wood (see Patent Document 1 below).

[0005] Furthermore, there is proposed a decorative sheet having "at least a base layer, a first surface layer, and a second surface layer provided on a part of the first surface layer, in this order, the second surface layer being formed from a resin composition containing a resin and synthetic resin particles, and the second surface layer containing 50 parts by mass or more of the synthetic resin particles per 100 parts by mass of the resin," which has excellent formability and scratch resistance, and also has an excellent tactile feel that gives a sense of three-dimensionality when actually touched with the hand (see Patent Document 2 below).

[0006] Furthermore, there is a decorative sheet in which "at least convex portions containing a resin are formed on a base sheet, and the convex portions contain 15 to 75 mass % organic particles having an average particle size of 12 to 45 μm," and it is proposed that the whitening of the convex portions is suppressed and that the sheet has an excellent feel even after being processed into a decorative board (see Patent Document 3 below). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-262105 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-66732 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-203432 Summary of the Invention [Problem to be solved by the invention]

[0008] Conventionally, as described above, the surface feel of a covering sheet has been changed by blending particles of an appropriate size into the outermost surface layer of the covering sheet to form irregularities. However, the coating sheets disclosed in the above Patent Documents 1 to 3 contain particles with large particle diameters or at high blending ratios, resulting in a matte finish, which results in a loss of transparency and a whitish appearance, which may impair the design of the molded body itself that is being coated.

[0009] Therefore, the inventors of the present invention conducted extensive research and discovered that by adjusting the material, properties, and proportions of the particles to be blended within appropriate ranges, the coated molded body can be made to have transparency that does not impair the design of the molded body itself, and the surface has a good feel (tactile sensation), thereby achieving the present invention.

[0010] An object of the present invention is to provide a laminate having transparency that does not impair the design of the molded article itself that it covers, and having a surface that feels good to the touch, and a decorative film including the laminate. [Means for solving the problem]

[0011] The present invention is summarized as follows [1] to

[12] .

[0012] [1] A laminate having a coating layer on the outermost surface of a substrate, the coating layer comprising particles contained in a polyurethane resin, wherein the particles have a hardness of 0.1 MPa to 800 MPa and a composite modulus of elasticity of 0.01 GPa to 10 GPa, and the haze of the laminate is 78% or less. [2] The laminate according to [1], wherein the coating layer has a dynamic friction coefficient of 1.90 or less. [3] A laminate having a coating layer made of polyurethane resin containing particles on the outermost surface of a substrate, wherein the dynamic friction coefficient of the laminate is 1.90 or less and the haze is 78% or less. [4] The laminate according to [3], wherein the particles have a hardness of 0.1 MPa to 800 MPa and a composite modulus of elasticity of 0.01 GPa to 10 GPa. [5] The laminate according to any one of [1] to [4], wherein the particles have an average particle size of 1 μm to 10 μm. [6] The laminate according to any one of [1] to [5], wherein the coating layer contains 1 to 50 parts by mass of the particles per 100 parts by mass of the polyurethane resin. [7] The laminate according to any one of [1] to [6], wherein the particles are acrylic particles or urethane particles. [8] The laminate according to any one of [1] to [7], wherein the thickness of the laminate is 1 μm to 1000 μm. [9] The laminate according to any one of [1] to [8], wherein the coating layer has a static friction coefficient of 4.80 or less.

[10] The laminate according to any one of [1] to [9], wherein the coating layer has a thickness of 0.1 μm to 50 μm.

[11] The laminate according to any one of [1] to

[10] , wherein the substrate is composed mainly of an acrylic resin.

[12] A decorative film comprising the laminate according to any one of [1] to

[11] . [Effects of the Invention]

[0013] The laminate of the present invention has transparency that does not impair the design of the molded article to be covered, and can provide a laminate with a good surface feel (tactile sensation). This laminate is suitable as a decorative film for covering the surfaces of industrial products such as automobile interior parts and home appliances. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the laminate of the present invention will be described below, but the present invention is not limited to this embodiment.

[0015] The laminate of the first embodiment of the present invention is a laminate having a coating layer on the outermost surface of a substrate, the coating layer comprising particles contained in a polyurethane resin, characterized in that the particles have a hardness of 0.1 MPa to 800 MPa, a composite modulus of elasticity of 0.01 GPa to 10 GPa, and a haze of 78% or less. The laminate of the second embodiment of the present invention is a laminate having a coating layer made of a polyurethane resin containing particles on the outermost surface of a substrate, and is characterized in that the dynamic friction coefficient of the laminate is 1.90 or less and the haze is 78% or less. In the following description, the laminates of the first and second embodiments will be collectively referred to as the present laminate.

[0016] <Coating layer> The coating layer is a layer disposed on the outermost surface of the present laminate, and is made of a polyurethane resin containing particles.

[0017] (Polyurethane resin) The polyurethane resin used in the coating layer is a general term for polymers containing urethane bonds, and is usually produced by a polyaddition reaction between a compound containing an isocyanate group and a compound containing a hydroxyl group. Generally, one-component and two-component polyurethanes are used, but two-component polyurethanes are preferred from the standpoint of storage stability. When a two-component polyurethane is used as the resin component, a chain extender, a curing accelerator, a filler, a solvent, etc. may be added to the polyols and polyisocyanates as needed. For curing in the polyaddition reaction, known methods such as heat curing and active energy ray curing using ultraviolet rays or electron beams can be used, with heat curing being preferred.

[0018] As the polyol, polymer polyols are mainly used. Examples of the polymer polyols include polycarbonate polyols, polyester polyols, polyether polyols, and polyetherester polyols. From the viewpoints of adhesion to the substrate and tactile feel, polycarbonate polyols or polyester polyols are preferred. Specifically, 1,4-butanediol, 1,20-decanediol, etc. are preferred.

[0019] Examples of polyisocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, aromatic polyisocyanates, and polyisocyanate derivatives. Examples of aliphatic polyisocyanates include tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate. Examples of alicyclic polyisocyanates include 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), hydrogenated xylylene diisocyanate, and norbornane diisocyanate. Examples of araliphatic polyisocyanates include xylylene diisocyanate and tetramethylxylylene diisocyanate. Examples of aromatic polyisocyanates include phenylene diisocyanate, 1,5-naphthylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, 4,4'-toluidine diisocyanate, and 4,4'-diphenyl ether diisocyanate. Examples of polyisocyanate derivatives include multimers such as dimers and trimers, biurets, allophanates, carbodiimides, and uretdione. These polyisocyanates can be used alone or in combination.

[0020] Among these polyisocyanates, from the viewpoint of stability, non-yellowing diisocyanates or derivatives thereof, for example, aliphatic diisocyanates, isophoric diisocyanates, and alicyclic diisocyanates such as hydrogenated xylylene diisocyanate, are preferred. These polyisocyanates can be used alone or in combination.

[0021] Examples of the chain extender include diols such as aliphatic diols and alicyclic diols, alkanolamines, diamines, alicyclic diamines, aromatic diamines, and aromatic aliphatic diamines. These chain extenders can be used alone or in combination.

[0022] Examples of the curing accelerator include amine catalysts and metal catalysts. Examples of amine catalysts include monoamines such as triethylamine and N,N-dimethylcyclohexylamine, diamines such as tetramethylethylenediamine, other triamines, cyclic amines, alcohol amines such as dimethylethanolamine, and ether amines. Examples of metal catalysts include lead octoate, dibutyltin dilaurate, tin octoate, zinc octoate, potassium acetate, potassium 2-ethylhexanoate, calcium acetate, and phosphine.

[0023] The polyurethane resin may be a copolymer with a polymerizable monomer such as an acrylic, methacrylic, or ester monomer. Copolymers of these polymers with other polymers are also included, such as block copolymers and graft copolymers. That is, the polyurethane resin may be an acrylic-modified polyurethane resin.

[0024] The polyurethane resin obtained from these polyols and polyisocyanates has moderate elasticity and good durability, and exhibits excellent mixing and dispersibility when mixed with the particles described below, making it possible to obtain a coating layer that has a good soft feel and touch.

[0025] <Particle> The particles used in the coating layer preferably have a hardness of 0.1 MPa to 800 MPa and a composite elastic modulus of 0.01 GPa to 10 GPa. The particles may be either inorganic particles or organic particles, and multiple types may be used. Examples include acrylic particles, urethane particles, and silica particles, and among these, acrylic particles or urethane particles are preferred.

[0026] Examples of acrylic resins used in acrylic particles include polymers made of polymerizable monomers including acrylic and methacrylic monomers, which may be homopolymers or copolymers, or copolymers with polymerizable monomers other than acrylic and methacrylic monomers. Also included are copolymers of these polymers with other polymers (such as polyesters and polyurethanes), such as block copolymers and graft copolymers. That is, the acrylic resin may be an acrylic-modified polyester resin. Furthermore, the term also includes polymers (or polymer mixtures, as the case may be) obtained by polymerizing polymerizable monomers in a polyester solution or polyester dispersion. Similarly, the term also includes polymers (or polymer mixtures, as the case may be) obtained by polymerizing polymerizable monomers in a polyurethane solution or polyurethane dispersion. Similarly, the term also includes polymers (or polymer mixtures, as the case may be) obtained by polymerizing polymerizable monomers in other polymer solutions or dispersions.

[0027] The polymerizable monomer is not particularly limited, but examples thereof include various carboxyl group-containing monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and citraconic acid, and salts thereof; various hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, monobutylhydroxyfumarate, and monobutylhydroxyitaconate; methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and lauryl (meth)acrylate. various nitrogen-containing compounds such as (meth)acrylamide, diacetone acrylamide, N-methylolacrylamide, or (meth)acrylonitrile; various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene, or vinyltoluene; various vinyl esters such as vinyl propionate; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane; phosphorus-containing vinyl monomers; various vinyl halides such as vinyl chloride and vinylidene chloride; and various conjugated dienes such as butadiene.

[0028] Examples of the urethane resin used for the urethane particles include the polyurethane resins described above.

[0029] (Average particle size) The particles contained in the coating layer preferably have an average particle size of 1 μm to 10 μm, more preferably 1.5 μm to 9.5 μm, and particularly preferably 2 μm to 8.5 μm. The inclusion of particles having an average particle size of 1 μm or more provides a soft touch when touched with fingers and also tends to improve the matte finish and the appearance of black when layered on a black substrate or paper material. On the other hand, the inclusion of particles having an average particle size of 10 μm or less provides a laminate that is less scratchy when touched with fingers and has good abrasion resistance. The detailed method for measuring the average particle size will be described later.

[0030] The shape of the particles is not particularly limited, and examples thereof include spheres, ellipsoids, polygonal shapes such as polygonal pyramids, cubes, rectangular parallelepipeds, and plates, rods, irregular shapes, etc. Among these shapes, spheres or ellipsoids are preferred, and perfect spheres or nearly perfect spheres are particularly preferred, in view of smoothness, excellent softness, and excellent tactile feel.

[0031] (physical properties) The particles contained in the coating layer preferably have a hardness of 0.1 MPa to 800 MPa, more preferably 1.0 MPa to 700 MPa, and particularly preferably 2.0 MPa to 600 MPa. When the particle hardness is 0.1 MPa or more, the particles are not too soft and a good feel can be obtained. When the particle hardness is 800 MPa or less, the particles are not too hard and a good feel can be obtained. The particles preferably have a composite modulus of elasticity of 0.01 GPa to 10 GPa, more preferably 0.02 GPa to 9 GPa, and particularly preferably 0.03 GPa to 8 GPa. When the particles have a composite modulus of elasticity of 0.01 GPa or more, the particles are not too soft and have a good feel to the touch. When the particles have a composite modulus of elasticity of 10 GPa or less, the particles are not too hard and have a good feel to the touch. The composite elastic modulus is the elastic modulus obtained by the nanoindentation method, which combines the Young's modulus and Poisson's ratio of the indenter. (For a detailed explanation of the composite elastic modulus, see, for example, "Shimizu Satoshi. Fracture, Electrical, and Viscoelasticity Measurement Technology in Microscopic Areas. Journal of the Japan Society for Precision Engineering. 2013, 79(12), pp. 1204-1207.") The hardness and composite modulus can be measured by the methods shown in the examples below.

[0032] (mixing ratio) The coating layer is mainly composed of a polyurethane resin. In the present invention, the term "main component" refers to a component that accounts for 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more. The content of the particles is preferably 1 to 50 parts by mass per 100 parts by mass of polyurethane resin, more preferably 1.5 to 47 parts by mass of particles per 100 parts by mass of polyurethane resin, and particularly preferably 2 to 44 parts by mass of particles.

[0033] In addition to the above particles, the particles contained in the coating layer preferably further include silica particles having an average particle size of less than 1.8 μm. The average particle size of this silica is preferably less than 1.8 μm, more preferably less than 1.5 μm, even more preferably less than 1.0 μm, and particularly preferably less than 0.8 μm. By including silica particles having an average particle size of less than 1.8 μm, it becomes easier to adjust the balance between transparency and tactile feel of the laminate. The silica particles having an average particle size of 1.8 μm or less are preferably contained in an amount of 0.1 to 10 parts by mass, more preferably 0.2 to 7.5 parts by mass, and even more preferably 0.3 to 5 parts by mass, per 100 parts by mass of polyurethane resin. By containing 0.1 to 10 parts by mass of silica particles having an average particle size of 1.8 μm or less per 100 parts by mass of polyurethane resin, it becomes easier to adjust the balance between transparency and tactile feel of the laminate. The total amount of particles, including the silica particles, is preferably 1 to 50 parts by mass per 100 parts by mass of polyurethane resin, more preferably 1.5 to 47 parts by mass of particles per 100 parts by mass of polyurethane resin, and particularly preferably 2 to 44 parts by mass of particles.

[0034] The coating layer may contain other additives that do not have a particle shape, as needed. For example, various additives such as film-forming aids, crosslinking agents, curing accelerators, plasticizers, antistatic agents, waxes, surfactants, light stabilizers, flow adjusters, leveling agents, rheology control agents, ultraviolet absorbers, antioxidants, photocatalytic compounds, matting agents, dyes, colorants, inorganic pigments, organic pigments, and extender pigments can be used.

[0035] (Thickness) The thickness of the coating layer can be appropriately selected depending on the application, but is preferably 0.1 μm to 50 μm, more preferably 0.5 μm to 30 μm, and particularly preferably 1 μm to 10 μm.

[0036] (coefficient of friction) The surface of the coating layer of the present laminate has predetermined frictional properties depending on the materials and blending of the polyurethane resin and particles that make up the coating layer, which affect the smoothness and feel.

[0037] The coefficient of dynamic friction of the coating layer surface of the present laminate is preferably 1.90 or less, more preferably 1.85 or less, and particularly preferably 1.80 or less. The lower limit is not particularly limited, but is preferably 0.10 or more, more preferably 0.15 or more, and particularly preferably 0.20 or more. If the dynamic friction coefficient is 1.90 or less, the frictional resistance when sliding a finger over the surface of the coating layer will not be too high, and the coating layer will not feel sticky or sticky.

[0038] The static friction coefficient of the coating layer surface of the present laminate is preferably 4.80 or less, more preferably 4.60 or less, and particularly preferably 4.40 or less. There are no particular restrictions on the lower limit, but it is preferably 0.30 or more, more preferably 0.45 or more, and particularly preferably 0.60 or more. If the static friction coefficient is 4.80 or less, the frictional resistance will not be too high when a finger touches the surface of the coating layer, making it difficult for the finger to feel sticky or sticky. The dynamic friction coefficient and static friction coefficient can be adjusted by, for example, the material, particle size, and ratio of the particles to be blended in the coating layer, and can also be measured by the method shown in the examples below.

[0039] <Base material> The substrate of the present laminate can be a resin film or a resin sheet. Examples of resin films or resin sheets used as the substrate include films or sheets whose main component is polyolefin resin, polyester resin, acrylic resin, etc., and among these, films or sheets whose main component is acrylic resin are preferred. The acrylic resin may be the acrylic resin shown above for the particles. The resin film or resin sheet may be of either a single-layer structure or a multi-layer structure, and may be any of unstretched, uniaxially stretched, and biaxially stretched films or sheets.

[0040] The thickness of the substrate can be appropriately selected depending on the application, but is preferably 1 μm to 1000 μm, more preferably 3 μm to 750 μm, and particularly preferably 5 μm to 500 μm.

[0041] <This laminate> The laminate has a coating layer on one surface of a substrate and has a haze value of 78% or less, preferably 76% or less, and more preferably 75% or less. The haze value can be adjusted, for example, by the particle size, the type, amount, thickness, etc. of particles added, and can be calculated as the ratio of diffuse transmittance to total light transmittance. The total light transmittance and diffuse transmittance can be measured in accordance with JIS K7136 (2000).

[0042] In the present laminate, one or more other layers, such as an anchor coat layer, may be provided between the substrate and the coating layer.

[0043] The thickness of the present laminate can be appropriately selected depending on the application, but is preferably 1 μm to 1000 μm, more preferably 3 μm to 750 μm, and particularly preferably 5 μm to 500 μm.

[0044] <Method of manufacturing the present laminate> The present laminate can be produced by forming a coating layer on a substrate. In order to ensure sufficient adhesive strength between the coating layer and the substrate, a coating method in which the composition constituting the coating layer is applied to the surface of the substrate is preferred.

[0045] As the application method, known methods can be used, and examples thereof include methods using a bar coater, gravure coater, die coater, roll coater, comma coater, knife coater, air knife coater, curtain coater, kiss coater, shower coater, flow coater, or spin coater, as well as dipping, screen printing, spraying, brush coating, and applicators. For example, when a resin film is used as the substrate, the coating may be applied after the film is produced, or when the film is produced by sequential biaxial stretching, the coating may be applied between the longitudinal and transverse stretching steps. From the viewpoint of applying a thin and uniform coating, the use of a gravure coater or a die coater is preferred, and the use of a gravure coater is particularly preferred because it can be applied to a variety of substrates and is suitable for thin coating.

[0046] Gravure coating is a coating method that uses a gravure roll with concave cells formed on the outer peripheral surface of the roll plate. After the coating liquid is supplied to the gravure roll, unnecessary coating liquid is scraped off using a doctor blade, and a substrate such as a film is sandwiched between the gravure roll and the backup roll on the side opposite the gravure roll is pressed against the substrate to bring the substrate and the gravure roll into contact, and then the substrate is peeled off, allowing the coating liquid filled in the cells of the gravure roll plate to be transferred to the substrate, thereby applying the coating liquid to the substrate. A method in which the gravure roll and the backup roll are in contact with each other with the substrate sandwiched therebetween and the rotation direction of the gravure roll and the transport direction of the film are the same is called direct gravure coating, and a method in which the rotation direction of the gravure roll and the transport direction of the film are opposite is called direct reverse gravure coating. Either method can be selected and used as appropriate.

[0047] The cell shape of the gravure roll can be selected from oblique, pyramidal, lattice, tortoiseshell, etc. depending on the properties of the coating liquid, such as viscosity. The coating thickness can also be adjusted by the cell depth and the solids concentration of the coating liquid.

[0048] Furthermore, from the viewpoint of using a resin film as a substrate and applying a thin, uniform coating, it is preferable that the composition constituting the coating layer contains a solvent, and that the coating layer is formed by applying the composition and drying the solvent. The solvent can be selected depending on the solubility of the polyurethane resin constituting the coating layer, and any solvent that can uniformly dissolve the polyurethane resin may be used. Examples include ketones, ethers, hydrocarbons, esters, water, alcohols, and amides. These solvents can be used alone or in combination of two or more, and may also be mixed solvents. Among these solvents, water, alcohols such as isopropanol, esters such as ethyl acetate, and aromatic hydrocarbons such as toluene are commonly used.

[0049] The solvent may be dried at a temperature of, for example, 40°C to 150°C, preferably 60°C to 120°C, and more preferably 70°C to 90°C. The drying temperature can be appropriately selected depending on the thickness and thermal stability of the substrate, the process speed, etc. A heating step may be provided to accelerate curing, and the temperature and time should be selected from the viewpoint of the stability of the substrate and the coating layer.

[0050] In order to improve the applicability of the composition constituting the coating layer and the adhesion between the coating layer and the substrate, the surface of the substrate may be subjected to a surface treatment such as a chemical treatment or a discharge treatment before forming the coating layer. In addition, in order to further improve the surface properties, a discharge treatment may be performed after forming the coating layer.

[0051] The present laminate may be provided with a bonding layer on the surface opposite to the surface on which the coating layer is provided, for laminating onto a molded article or the like.

[0052] (Joining layer) The bonding layer can be made of a known adhesive resin, and is not particularly limited as long as it has adhesive properties between the substrate and other materials. For bonding, known methods such as thermal lamination, extrusion lamination, and dry lamination can be used, and an adhesive resin suitable for these methods can be used. Among these, the thermal lamination method is preferred because it has a low environmental impact since lamination can be performed using only heat without using volatile organic compounds (VOCs) such as organic solvents, and also because thermal lamination can be performed as is if an adhesive resin layer is previously formed on the substrate film. In order to further enhance the adhesiveness, an anchor layer may be provided between the substrate and the bonding layer, if necessary.

[0053] Adhesive resins constituting the bonding layer for thermal lamination and extrusion lamination include, for example, ethylene-α-olefin copolymers, ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid ester copolymers, polyamide resins, and polyester resins. Elastomers such as styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers, natural rubber, and acrylic resins may also be mixed. Furthermore, to enhance adhesion, resins modified to include functional groups or polar groups, such as carboxyl groups or acid anhydride groups, are more preferred. These adhesive resins can be used alone or in combination, and can be selected according to the application. Among these, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, and ethylene-(meth)acrylic acid ester copolymer are preferred from the viewpoints of adhesive strength with other materials and versatility. In the case of thermal lamination, a coextruded multilayer film can be produced in which a bonding layer made of these resins is used as an outer layer on one side (opposite the side on which the coating layer is formed) of the plastic film used as the base material of the laminated film of the present invention.

[0054] Examples of adhesive resins for dry lamination include known urethane-based, acrylic-based, polyester-based, epoxy-based, vinyl acetate-based, cellulose-based, etc. The curing agent used therefor is not particularly limited, and examples thereof include known isocyanate-based, melamine-based, oxazoline-based, aziridine-based, and epoxy-based curing agents.

[0055] The thickness of the bonding layer can be appropriately selected depending on the intended use, but is preferably 0.1 μm to 10 μm, more preferably 0.2 μm to 7.5 μm, and particularly preferably 0.3 μm to 3 μm.

[0056] (Application) This laminate has transparency and a good surface feel (touch), making it suitable for use as a decorative sheet to cover the surfaces of industrial products such as automobile parts and home appliances. Molded articles that can be covered with this decorative sheet include resins and metals. It is particularly preferred to use it as a decorative sheet for automobile interior parts made of resin molded articles such as instrument panels and airbag covers.

[0057] In the present invention, when expressed as "X to Y" (X and Y are any numbers), unless otherwise specified, it includes the meaning of "X or more and Y or less", as well as "preferably larger than X" and "preferably smaller than Y". [Example]

[0058] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0059] The following examples and comparative examples were prepared using the following materials. Paint 1: Polycarbonate diol solution (1,4-butanediol 58.1 wt%, 1,10-decanediol 41.9 wt%), solid content 38%, refractive index 1.49 Hardener 1: Polyisocyanate hardener solution (isocyanurate of pentamethylene diisocyanate), solid content 50% Diluent (solvent) 1: Thinner (a mixture of ethyl acetate and methyl ethyl ketone, mixed in a volume ratio of 1:1) Substrate 1: Acrylic film (Acryplene HBA002P: manufactured by Mitsubishi Chemical Corporation), thickness 77 μm

[0060] (Preparation of Example 1) Coating material 1, curing agent 1, and diluent 1 were mixed in a mass ratio of 5:1:5, and the particles shown in Table 1 were added and dispersed to prepare a coating liquid. The prepared coating liquid was applied to the substrate 1 using a bar coater #4 to form a coating layer, and then dried in a hot air dryer at 90°C for 3 minutes to produce a laminate. The coating layer was adjusted to have a thickness of 3 μm after drying. The physical properties of the obtained laminate are shown in Table 1.

[0061] (Preparation of Examples 2 to 19 and Comparative Examples 1 to 3) In Examples 2 to 19 and Comparative Example 3, laminates were produced in the same manner as in Example 1, except that the particles added were changed as shown in Tables 1 to 3. Note that Comparative Example 1 contained only the substrate, and Comparative Example 2 did not contain any particles in the coating layer. The physical properties of the resulting laminates are shown in Tables 1 to 3.

[0062] (Physical property measurement) The physical properties were measured for Examples 1 to 19 and Comparative Examples 1 to 3. The methods for measuring the physical properties are shown below.

[0063] <Static friction coefficient, dynamic friction coefficient> The dynamic friction coefficient and static friction coefficient were calculated from the results of the friction measurement shown below. Friction measurements were carried out using a tactile contactor on a static and dynamic friction measuring instrument (TL201Tt) manufactured by Trinity Labs, Inc., at a test temperature of 23°C and a test humidity of 50%. The test conditions were a load of 20g, a speed of 2.5mm / sec, and an operating distance of 50mm. The static friction coefficient was calculated using the following formula from the maximum friction force when the contact started to move. μ s =F s / m×g μ s : coefficient of static friction, F s: static friction force, m: load, g: gravitational acceleration The coefficient of dynamic friction was calculated using the following formula from the average value of the friction force obtained in the search range of 10 to 40 mm. μ d =F d / m×g μ d : Coefficient of kinetic friction, F d :Dynamic friction force, m: Load, g: Gravitational acceleration

[0064] <Haze> Using a haze meter NDH-7000II (manufactured by Nippon Denshoku Industries Co., Ltd.), the total light transmittance and diffuse transmittance were measured based on JIS K7136 (2000), and the haze was calculated using the following formula. [Haze] = ([Diffuse transmittance] / [Total light transmittance]) x 100

[0065] <Particle hardness and composite elastic modulus> Since it was not possible to measure particles with an average particle size of less than 1.0 μm, the hardness and composite modulus of elasticity were measured for particles with an average particle size of 1.0 μm or more. The particles were added to an embedding agent, which was then thermally cured, and the surface was polished to expose the cross section of the particles. The obtained samples were examined using a microscope mounted on a nanoindenter (Bruker, TI-980) to find particle cross sections with diameters close to the average particle size. An indentation test was performed on the particle cross sections using a diamond Berkovich-type (triangular pyramidal) probe to obtain displacement-load hysteresis curves. The indentation test was performed in load-controlled mode under the following conditions: maximum load 25 μN, loading rate 5 μm / sec, holding time 2 sec, and unloading rate 5 μm / sec. The obtained displacement-load hysteresis curves were numerically processed using the instrument's accompanying software (triboscan) for the range of 5 to 23.75 μN to calculate the composite elastic modulus and indentation hardness. The area function used to correct the shape of the Berkovich probe was determined from an indentation test on quartz glass.

[0066] <Average particle size> Observation samples were prepared by attaching double-sided carbon tape to a sample stage and attaching particles to the tape without changing their shape. SEM images (secondary electron images) of these particle samples were acquired using a Regulus SU8220 scanning electron microscope (Hitachi High-Tech) at an accelerating voltage of 3 kV and a magnification of 1000x. The images were then binarized using image analysis software (ImageJ), and interparticle boundaries were separated within the software. The images obtained after this series of image processing operations were then analyzed using the software to obtain particle area results. Since the area obtained is in pixels, the length per pixel was measured using the scale bar included in the SEM image. After converting the pixel to μm, the particle diameter was calculated from the obtained area to obtain the particle size. The average particle size was calculated as the average value of at least 300 particles.

[0067] <Tactile sensation> The overall feel when the fingertip was lightly placed on the surface of the coating layer of the laminated film and rubbed with the finger from side to side was evaluated according to the following criteria. ○: The surface is smooth to the fingertips, has moderate resistance, and feels comfortable to the touch. ×: If you feel a lot of resistance or vibration in your fingertips, or if your fingertips are not sliding smoothly due to the grip, etc.

[0068] [Table 1]

[0069] [Table 2]

[0070] [Table 3]

[0071] (result) The laminates of Examples 1 to 19 had a transparency that did not impair the design when visually inspected, and the surface of the laminate also felt good when stroked with a fingertip. On the other hand, in Comparative Example 3, where the haze was over 78%, the appearance looked whitish, and therefore it is thought that there will be problems with the design when used for automobile interiors, etc. In addition, in Comparative Examples 1 and 2, in which the coefficient of dynamic friction exceeded 1.90, there was a feeling of grip, but the fingertips did not slide smoothly, and the feel was not good.

Claims

1. A laminate having a coating layer on the outermost surface of a substrate, the coating layer comprising particles contained in a polyurethane resin, wherein the particles have a hardness of 0.1 MPa to 800 MPa and a composite modulus of elasticity of 0.01 GPa to 10 GPa, and the coating layer surface of the laminate has a static friction coefficient of 2.21 to 4.80 and a haze of 78% or less.

2. 2. The laminate according to claim 1, wherein the coating layer has a surface with a dynamic friction coefficient of 1.90 or less.

3. A laminate having a coating layer on the outermost surface of a substrate, the coating layer comprising particles contained in a polyurethane resin, wherein the coating layer surface of the laminate has a dynamic friction coefficient of 1.90 or less, a static friction coefficient of 2.21 to 4.80, and a haze of 78% or less.

4. 4. The laminate according to claim 3, wherein the particles have a hardness of 0.1 MPa to 800 MPa and a composite modulus of elasticity of 0.01 GPa to 10 GPa.

5. A laminate described in any one of claims 1 to 4, wherein the particles are acrylic particles or urethane particles and have an average particle size of 1 μm to 10 μm.

6. 6. The laminate according to claim 5, wherein the coating layer contains 1 to 50 parts by mass of the particles per 100 parts by mass of the polyurethane resin.

7. A laminate described in claim 5 or 6, wherein the coating layer further contains silica particles having an average particle size of less than 1.8 μm.

8. A laminate described in any one of claims 1 to 7, wherein the polyurethane resin is a reaction product of polyols and polyisocyanates.

9. 9. The laminate according to claim 1, wherein the thickness of the laminate is 1 μm to 1000 μm.

10. The laminate according to any one of claims 1 to 9, wherein the coating layer has a thickness of 0.1 µm to 50 µm.

11. The laminate according to any one of claims 1 to 10, wherein the substrate is composed mainly of an acrylic resin.

12. A decorative film comprising the laminate according to any one of claims 1 to 11.

Images