Laminate and its manufacturing method

Abstract

The present invention provides a laminate including an acrylic-resin-containing layer and a thermoplastic-polyurethane-resin-containing layer, the laminate being such that the uniformity in the thickness of the thermoplastic-polyurethane-resin-containing layer is excellent, roughening of the interface between the acrylic-resin-containing layer and the thermoplastic-polyurethane-resin-containing layer is suppressed, and exceptional scratch resistance and chemical resistance are exhibited. The laminate (1) according to the present invention includes a laminate structure formed from a base-material layer (21) composed of a resin composition (A) that contains an acrylic resin, and a surface layer (22) composed of a resin composition (B) that contains a thermoplastic polyurethane resin (b1) having structural units derived from polyols and aliphatic diisocyanates, the laminate satisfying formula (1), where ηA and ηB represent the melt viscosity of the resin composition (A) and the resin composition (B), respectively, as measured at a temperature of 220°C and a shear rate of 50 s-1. Formula (1): 0.03≤ηB / ηA≤2.00

Description

Technical Field

[0001] The present invention relates to a laminate including a base material layer containing an acrylic resin and a surface layer containing a polyurethane resin, and a method for producing the same.

Background Art

[0002] Films and sheets made of acrylic resins are excellent in properties such as transparency and weather resistance. For example, the film is used as a surface protection film for optical parts of electrical products, interior and exterior parts of automobiles, signboards, building materials, and various molded products for indoor or outdoor use, and the sheet is used for furniture, signboards, and front panels of vending machines, etc. Generally, acrylic resins are excellent in surface hardness such as pencil hardness, but their scratch resistance and chemical resistance are not so excellent and are equivalent to those of other resins such as polycarbonate resins. Therefore, conventionally, in applications where scratch resistance or chemical resistance is required (for example, applications such as interior and exterior parts of automobiles and building materials), in order to ensure those physical properties, a hard coating agent or a self-healing coating agent is applied to the surface of the acrylic resin and cured to form a cured film.

[0003] Polyurethane resins are known as resins excellent in scratch resistance and chemical resistance. Patent Document 1 discloses a laminated film including an acrylic resin layer and a polyurethane resin layer having self-healing properties and scratch resistance (Claim 4). Patent Document 2 discloses a laminated film in which acrylic resin layers are laminated on both sides of a thermoplastic polyurethane resin layer (core layer) (Claim 1). Since this laminated film includes an intermediate layer made of a thermoplastic polyurethane resin, the tear resistance can be improved (Table 2). As a method for producing the laminated film, a coextrusion molding method is mentioned (Paragraph 0023).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] In Patent Document 1, the polyurethane-based resin is a thermosetting polyurethane-based resin. The method for manufacturing the laminated film described in this document requires a step of forming an acrylic resin film, a step of applying a curable composition containing a thermosetting polyurethane-based resin onto the acrylic resin film, and a step of curing the applied film. The number of steps is large and the cost is high. In addition, since the thermosetting polyurethane-based resin has poor stretchability, there are limitations in the shape design when thermoforming the obtained laminated film. In the laminated film described in Patent Document 2, since a thermoplastic polyurethane-based resin is used in the intermediate layer, the effects of improving scratch resistance and chemical resistance cannot be obtained.

[0006] Conventionally, for the following reasons, it has been difficult to co-extrusion mold an acrylic resin and a thermoplastic polyurethane-based resin, and it has been necessary to perform molding within a very narrow temperature range. Generally, a thermoplastic polyurethane-based resin has a tendency to have a reduced viscosity due to thermal decomposition of urethane bonds in a high-temperature region, while its melt fluidity tends to decrease due to formation of physical crosslinking points in a low-temperature region. Therefore, generally, when extruding a thermoplastic polyurethane-based resin, the variation in melt viscosity with respect to temperature change is large, and there is a risk of resin sagging and deformation immediately after the resin exits the extruder. In addition, when co-extrusion molding a thermoplastic polyurethane-based resin and another resin, depending on the relationship between the melt viscosities of these resins, there is a risk that the thickness ratio of the layers of the two resins in the width direction becomes non-uniform, and roughness may occur at the interface between the two resin layers, resulting in a decrease in the interfacial adhesion between the two resin layers.

[0007] The present invention has been made in view of the above circumstances, and includes an acrylic resin-containing layer and a thermoplastic polyurethane resin-containing layer. The thermoplastic polyurethane resin-containing layer has good thickness uniformity, and the interface roughness between the acrylic resin-containing layer and the thermoplastic polyurethane resin-containing layer is suppressed, and the object is to provide a laminate excellent in scratch resistance and chemical resistance.

Means for Solving the Problems

[0008] The present invention provides the following laminates [1] to

[11] and a method for producing the same. [1] A laminate structure including a base material layer made of a resin composition (A) containing an acrylic resin and a surface layer made of a resin composition (B) containing a thermoplastic polyurethane resin (b1) having structural units derived from a polyol and an aliphatic diisocyanate. When the melt viscosities measured under the conditions of a temperature of 220 °C and a shear rate of 50 s for the resin composition (A) and the resin composition (B) are η -1 and η A respectively, a laminate satisfying the following formula (1). B 0.03 ≦ η / η B ≦ 2.00 ··· Formula (1) A

[0009] [2] The laminate according to [1], wherein the resin composition (B) further contains a thermoplastic resin (b2) other than the thermoplastic polyurethane resin and the acrylic rubber particles. [3] When the refractive index of the thermoplastic polyurethane resin (b1) is n b1 and the refractive index of the thermoplastic resin (b2) is n b2 , the laminate according to [2], which satisfies the following formula (2). |n b1 -n b2 | ≦ 0.005 ··· Formula (2) [4] The laminate according to any one of [1] to [3], wherein the resin composition (B) further contains acrylic rubber particles (b3). [5] When the refractive index of the thermoplastic polyurethane resin (b1) is n b1 and the refractive index of the acrylic rubber particles (b3) is n b3 ​In this case, a laminate of [4] that satisfies the following equation (3). |n b1 -n b3 |≦0.005...Equation (3)

[0010] [6] A laminate of any of [1] to [5], wherein the resin composition (A) comprises a methacrylic resin (a1) and an acrylic elastomer (a2). [7] A laminate of [6] comprising an acrylic elastomer (a2) containing acrylic rubber particles (arx) with a number average particle size of 180-300 nm and acrylic rubber particles (ary) with a number average particle size of 50-170 nm. [8] A laminate of [6] or [7] comprising an acrylic elastomer (a2) and an acrylic block copolymer (ab).

[0011] [9] A laminate of any of [1] to [8] with a total thickness of 0.03 mm or more and less than 0.50 mm.

[10] A laminate of any of [1] to [8] with a total thickness of 0.50 mm or more and 8.00 mm or less.

[11] A method for manufacturing a laminate, comprising producing one of the laminates [1] to

[10] by co-extrusion molding. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a laminate comprising an acrylic resin-containing layer and a thermoplastic polyurethane resin-containing layer, wherein the thickness uniformity of the thermoplastic polyurethane resin-containing layer is good, interface roughness between the acrylic resin-containing layer and the thermoplastic polyurethane resin-containing layer is suppressed, and the laminate has excellent scratch resistance and chemical resistance. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic cross-sectional view of a laminate according to the first embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view of a laminate according to a second embodiment of the present invention. [Figure 3] This is a schematic diagram of a laminate manufacturing apparatus according to one embodiment of the present invention. [Modes for carrying out the invention]

[0014] [Laminated structure] The laminate of the present invention includes a laminated structure comprising a base layer made of a resin composition (A) containing one or more acrylic resins and a surface layer made of a resin composition (B) containing one or more thermoplastic polyurethane resins (b1). The laminate of the present invention may have a surface layer on at least one surface of the base layer. In the laminate of the present invention, the base layer is an acrylic resin-containing layer, and the surface layer is a thermoplastic polyurethane resin-containing layer.

[0015] Figures 1 and 2 are schematic cross-sectional views of laminates according to the first and second embodiments of the present invention. In the figures, reference numerals 1 and 2 indicate the laminate, reference numeral 21 indicates the base layer, and reference numeral 22 indicates the surface layer. The laminate 1 of the first embodiment is a two-layer laminate in which a surface layer 22 is laminated on one side of a base layer 21. The laminate 2 of the second embodiment is a three-layer laminate in which surface layers 22 are laminated on both sides of a base layer 21. Laminates 1 and 2 may have resin layers other than the base layer and the surface layer.

[0016] Acrylic resin-containing layers offer excellent transparency, weather resistance, and surface hardness, but their scratch resistance and chemical resistance are not particularly good. By laminating a thermoplastic polyurethane resin-containing layer, which has excellent scratch resistance and chemical resistance, onto at least one surface of this acrylic resin-containing layer, a laminate with excellent scratch resistance and chemical resistance can be provided. From the viewpoint of scratch resistance and chemical resistance, it is preferable that at least one of the outermost layers of the laminate of the present invention is a surface layer containing a thermoplastic polyurethane resin (b1).

[0017] The form of the laminate of the present invention is not particularly limited and includes films, sheets, plates, and any three-dimensional shapes. Generally, the terms "film," "sheet," or "plate" are used for thin film molded articles depending on their thickness, but there are no clear definitions of these terms, and there is no clear distinction between them. Preferred forms of the laminate of the present invention are films and sheets. The total thickness of the film is not particularly limited, for example, 0.03 mm or more and less than 0.50 mm, preferably 0.05 mm or more and less than 0.40 mm, and more preferably 0.07 mm or more and less than 0.2 mm. The total thickness of the sheet is not particularly limited, for example, 0.50 mm or more and 8.00 mm or less, preferably 1.00 mm or more and 5.00 mm or less, and more preferably 1.5 mm or more and 3.5 mm or less. The following description will focus on cases where the laminate of the present invention is a film or a sheet, but the form of the laminate of the present invention is not limited to these.

[0018] The method for manufacturing the laminate of the present invention is not particularly limited, but co-extrusion molding is preferred. Since the laminate of the present invention can be manufactured by co-extrusion molding, it can be manufactured at a low cost with fewer steps, unlike when a polyurethane resin-containing layer is formed using a hard coating agent or self-healing coating agent containing a thermosetting polyurethane resin. In the laminate of the present invention, a thermoplastic polyurethane resin with excellent stretchability is used as the surface layer material instead of a thermosetting polyurethane resin, which is preferable because it allows for greater freedom in designing the shape when thermoforming the laminate of the present invention.

[0019] As explained in the section on [Problems to be Solved by the Invention], it is generally difficult to manufacture a laminate containing an acrylic resin-containing layer and a thermoplastic polyurethane resin-containing layer by co-extrusion molding. The laminate of the present invention is formed by a temperature of 220°C and a shear rate of 50 s of resin composition (A) and resin composition (B). -1 The melt viscosity measured under the following conditions is η A η B When this is the case, the following equation (1) is satisfied. 0.03 ≤ η B / η A ≦2.00...Equation (1)

[0020] In this specification, unless otherwise specified, "melt viscosity" shall be measured using a capillary graph in accordance with JIS K7199, at a temperature of 220°C and a shear rate of 50 s. -1 This is the melt viscosity measured under these conditions. Generally, the shear rate applied to the resin during film or sheet extrusion molding is 10 to 100 s. -1 In this invention, the shear rate applied to the resin during the extrusion molding of the film or sheet is set to 50s as a representative value. -1 The melt viscosity is defined using [this method]. Generally, the extrusion molding temperature for films or sheets containing acrylic resin is 200 to 240°C. In this invention, 220°C is used as a representative value for the extrusion molding temperature of the film or sheet, and the melt viscosity is specified accordingly.

[0021] Equation (1) shows the melt viscosity η of resin composition (B). B and the melt viscosity η of the resin composition (A) A The ratio (η) B / η A ) defines η B / η A The lower limit is 0.03, preferably 0.05, more preferably 0.10, particularly preferably 0.15, and most preferably 0.30. B / η A The upper limit is 2.00, preferably 1.00, and more preferably 0.50. η B / η A If the above range is maintained, the thickness ratio between the substrate layer and the surface layer tends to be uniform in the width direction during co-extrusion, and the thickness of the surface layer in the width direction also tends to be uniform. Furthermore, interface roughness between the substrate layer and the surface layer caused by differences in melt viscosity can be suppressed. In this invention, the compositions of resin composition (A) and resin composition (B) are designed to satisfy formula (1). This improves the uniformity of the thickness ratio between the substrate layer and the surface layer, improves the uniformity of the thickness of the surface layer, and suppresses interface roughness between the substrate layer and the surface layer. In this specification, the width direction during co-extrusion is perpendicular to the resin extrusion direction (flow direction).

[0022] (base material layer) The base layer is an acrylic resin-containing layer made of a resin composition (A) containing one or more acrylic resins. The base layer may also be a laminate of two or more acrylic resin-containing layers. Since the base layer is made of an acrylic resin composition, it can possess the inherent properties of acrylic resins, such as transparency, weather resistance, and surface hardness. The thickness of the base layer is not particularly limited. When the laminate of the present invention is a film, the thickness of the base layer is preferably 0.03 mm or more and less than 0.5 mm, more preferably 0.05 mm or more and less than 0.3 mm, and particularly preferably 0.05 mm or more and less than 0.2 mm. When the laminate of the present invention is a sheet, the thickness of the base layer is preferably 0.5 mm or more and less than 8 mm, more preferably 1 mm or more and less than 4 mm, and particularly preferably 2 mm or more and less than 3.5 mm.

[0023] The acrylic resin is a homopolymer or copolymer containing one or more (meth)acrylic acid ester units, and known acrylic resins can be used. In this specification, (meth)acrylic is a general term for acrylic and methacrylic, and (meth)acrylonitrile is a general term for acrylonitrile and methacrylonitrile. The acrylic resin contained in the resin composition (A) preferably contains a methacrylic resin (a1), and more preferably contains both a methacrylic resin (a1) and an acrylic elastomer (a2).

[0024] <Methacrylic resin (a1)> The methacrylic resin (a1) is a homopolymer or copolymer containing one or more methacrylic acid ester units, and known ones can be used. From the viewpoint of transparency, the content of methacrylic acid ester units in the methacrylic resin (a1) is preferably 50% by mass or more, more preferably 80% by mass or more, particularly preferably 90% by mass or more, and may be 100% by mass.

[0025] The methacrylic acid ester is not particularly limited and includes methyl methacrylate (MMA), ethyl methacrylate, butyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate; monocyclic aliphatic hydrocarbon esters of methacrylic acid; polycyclic aliphatic hydrocarbon esters of methacrylic acid, etc. From the viewpoint of transparency, it is preferable that the methacrylic resin (a1) contains MMA units. The content of MMA units in the methacrylic resin (a1) is preferably 50% by mass or more, more preferably 80% by mass or more, particularly preferably 90% by mass or more, and may be 100% by mass.

[0026] The methacrylic resin (a1) may contain one or more other monomer units other than methacrylic acid ester units. Other monomers include acrylic acid esters such as methyl acrylate (MA), ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, and 2-hydroxyethyl acrylate; olefins such as ethylene, propylene, 1-butene, isobutylene, and 1-octene; conjugated dienes such as butadiene, isoprene, and myrcene; aromatic vinyl compounds such as styrene (St), 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-ethylstyrene, 4-t-butylstyrene, α-methylstyrene, and 4-methyl-α-methylstyrene; (meth)acrylamide, (meth)acrylonitrile; (meth)acrylic acid, (anhydride) maleic acid, and itaconic acid; maleimides such as phenylmaleimide and cyclohexylmaleimide; vinyl acetate, vinylpyridine, vinyl ketone, vinyl chloride, vinylidene chloride, and vinylidene fluoride; and the like. Among these, MA is preferred from the viewpoint of transparency. For example, a copolymer of MMA and MA is preferred because it has excellent transparency. The MMA content in this copolymer is preferably 80% by mass or more, more preferably 85% by mass or more, and particularly preferably 90% by mass or more.

[0027] The methacrylic resin (a1) is obtained by polymerizing one or more methacrylic acid esters, preferably containing MMA, and other monomers as needed. When multiple monomers are used, a monomer mixture is usually prepared by mixing the multiple monomers before polymerization. The polymerization method is not particularly limited, but from the viewpoint of productivity, radical polymerization methods such as bulk polymerization, suspension polymerization, solution polymerization, and emulsion polymerization are preferred.

[0028] Preferred methacrylic resins (a1) include polymethyl methacrylate (PMMA), copolymers of methyl methacrylate (MMA) and one or more (meth)acrylic acid esters, and methacrylic acid ester-styrene copolymers (MS resins). Examples of commercially available methacrylic resins (a1) include the following products. PMMA: Kuraray's "Parapet", Mitsubishi Chemical's "Acrypet", Sumitomo Chemical's "Sumipex", Asahi Kasei's "Delpet", MS resin: "Toyo MS" manufactured by Toyo Styrene.

[0029] <Acrylic elastomer (a2)> The acrylic elastomer (a2) is an elastomer having one or more alkyl acrylate units, and known elastomers can be used. When the resin composition (A) contains the acrylic elastomer (a2), the impact resistance, flexibility, and bending resistance of the laminate of the present invention can be improved. Examples of acrylic elastomers (a2) include acrylic rubber particles (ar) having an alkyl acrylate copolymer layer, acrylic block copolymers (ab) having an alkyl acrylate polymer block, and combinations thereof.

[0030] <Acrylic rubber particles (ar)> As acrylic rubber particles (ar), multilayer rubber particles with a core-shell structure consisting of an interior containing one or more rubber component layers and an exterior consisting of one or more thermoplastic resin component layers are preferred. The core of the acrylic rubber particle is considered as a "layer". The interior of the acrylic rubber particles (ar) consists of a core and, optionally, one or more intermediate layers. The number of layers of the acrylic rubber particles (ar) is two or more, and may be three or four or more. The upper limit of the number of layers is, for example, five. As for the acrylic rubber particles (ar), from the viewpoint of physical properties and ease of manufacture, multilayer polymer particles with a three-layer structure consisting of a first thermoplastic resin component layer (core), a rubber component layer (intermediate layer), and a second thermoplastic resin component layer (outer layer) from the center are preferred.

[0031] The mass ratio (rubber component layer / thermoplastic resin component layer) of the total amount of the rubber component layer to the total amount of the thermoplastic resin component layer is preferably 30 / 70 to 90 / 10. If the proportion of the rubber component layer is equal to or greater than the lower limit, the effects of improving the impact resistance, flexibility, and bending resistance of the laminate of the present invention can be effectively obtained. If the proportion of the rubber component layer exceeds the upper limit, it becomes difficult to form a particle structure, and the melt fluidity decreases, which may make it difficult to knead with other components and mold the resin composition (A).

[0032] The rubber component layer preferably contains a copolymer comprising 50 to 98.99% by mass of acrylic acid ester units, 44.99% to 1% by mass of other monofunctional monomer units, and 0.01 to 10% by mass of polyfunctional monomer units. The raw material monomers for the rubber component layer will be described below.

[0033] The acrylic acid ester is not particularly limited and examples include n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, pentyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, and cyclohexyl acrylate. One or more of these can be used.

[0034] Other monofunctional monomers are not particularly limited and include methacrylic acid esters such as methyl methacrylate (MMA), ethyl methacrylate, phenyl methacrylate, and benzyl methacrylate; aromatic vinyl monomers such as styrene (St), α-methylstyrene, 1-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, and halogenated styrene; and vinyl cyanide monomers such as (meth)acrylonitrile. One or more of these can be used. Styrene (St) is preferred among them.

[0035] A polyfunctional monomer is a monomer having two or more carbon-carbon double bonds in its molecule. The polyfunctional monomer is not particularly limited and examples include allyl (meth)acrylate, methyl (meth)acrylate, allyl cinnamate, methyl cinnamate, diallyl maleate, diallyl phthalate, diallyl terephthalate, diallyl isophthalate, divinylbenzene, ethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, and hexanediol di(meth)acrylate. One or more of these can be used. Among these, allyl methacrylate (ALMA) is preferred.

[0036] The thermoplastic resin component layer preferably contains a copolymer consisting of 40 to 100% by mass of methacrylic acid ester units and 60 to 0% by mass of other monomer units. The raw material monomers for the thermoplastic resin component layer will be described below. The methacrylic acid ester is not particularly limited and examples include methyl methacrylate (MMA), ethyl methacrylate, phenyl methacrylate, and benzyl methacrylate. One or more of these can be used. Among these, MMA is preferred. Other monomers are not particularly limited and include methyl acrylate (MA), ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate (BA); esters of acrylic acid with C5 or C6 alicyclic alcohols such as cyclohexyl acrylate; aromatic vinyl monomers such as styrene (St) and α-methylstyrene; vinyl cyanide monomers such as (meth)acrylonitrile; and polyfunctional monomers as exemplified in the rubber component layer. One or more of these can be used. Among these, alkyl acrylates such as methyl acrylate (MA), ethyl acrylate, and n-butyl acrylate (BA) are preferred.

[0037] The number-average particle diameter of the acrylic rubber particles (ar) is not particularly limited, but is preferably 50 to 300 nm. If the number-average particle diameter is greater than or equal to the lower limit, stress concentration in the acrylic rubber particles (ar) occurs effectively, and the effects of improving the impact resistance, flexibility, and bending resistance of the laminate of the present invention are effectively obtained. If the number-average particle diameter exceeds the upper limit, voids may be generated within the acrylic rubber particles (ar) due to stress during bending, etc., and whitening (also called stress whitening) may occur.

[0038] From the viewpoint of improving impact resistance, bending resistance, and flexural resistance by stress concentration on the particles, it is preferable that the acrylic rubber particles (ar) include acrylic rubber particles (arx) with a number average particle diameter of 180 to 300 nm. To effectively achieve both improved impact resistance, flexural resistance, and bending resistance through stress concentration on the particles, and suppression of void formation within the particles due to stress and the resulting whitening, multiple types of acrylic rubber particles (ar) with different number-average particle diameters can be used in combination. For example, the acrylic rubber particles (ar) can include acrylic rubber particles (arx) with a number-average particle diameter of 180 to 300 nm and acrylic rubber particles (ary) with a number-average particle diameter of 50 to 170 nm.

[0039] In this specification, unless otherwise specified, "number-average particle diameter of acrylic rubber particles" refers to the number-average particle diameter of the part of the acrylic rubber particle excluding the outer part consisting of one or more thermoplastic resin component layers, i.e., the part containing one or more rubber component layers. The number-average particle size of acrylic rubber particles can be measured, for example, by electron microscopy. A film or sheet containing acrylic rubber particles is electron-stained with phosphotungstic acid or ruthenium tetroxide, and observed with a transmission electron microscope. The particle sizes of multiple stained particles are measured, and their average value is calculated to determine the number-average particle size of the acrylic rubber particles. If the stained particles are non-spherical, their particle size is the average of their major axis diameter and minor axis diameter. For specific examples of evaluation methods, please refer to the [Examples] section below.

[0040] <Acrylic block copolymer (ab)> The acrylic block copolymer (ab) has one or more alkyl acrylate polymer blocks, preferably one or more methacrylic polymer blocks and one or more acrylic polymer blocks. From the viewpoint of compatibility, a block copolymer comprising 10 to 80% by mass of a methacrylic polymer block mainly having methacrylic acid ester units and 90 to 20% by mass of an acrylic polymer block mainly having acrylic acid ester units is preferred. However, the total amount of the methacrylic polymer block and the acrylic polymer block is set to 100% by mass.

[0041] The content of methacrylic acid ester units in the methacrylic polymer block is preferably 80% by mass or more, more preferably 90% by mass or more, particularly preferably 95% by mass or more, most preferably 98% by mass or more, and may also be 100% by mass. The methacrylic acid ester used as a raw material is not particularly limited, and examples include methyl methacrylate (MMA), ethyl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, glycidyl methacrylate, and allyl methacrylate (ALMA). One or more of these can be used. Among these, MMA is preferred from the viewpoint of transparency and heat resistance.

[0042] The content of acrylic acid ester units in the acrylic polymer block is preferably 45% by mass or more, more preferably 50% by mass or more, particularly preferably 60% by mass or more, and most preferably 90% by mass or more. The acrylic acid ester used as a raw material is not particularly limited and includes methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate (BA), i-butyl acrylate, s-butyl acrylate, t-butyl acrylate, phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, glycidyl acrylate, and allyl acrylate. One or more of these can be used.

[0043] The bonding configuration between the methacrylic polymer block and the acrylic polymer block in the acrylic block copolymer (ab) is not particularly limited. For example, a diblock copolymer or triblock copolymer in which a methacrylic polymer block is bonded to one or both ends of the acrylic polymer block is preferred.

[0044] In the resin composition (A), the content (total amount in the case of multiple types) of acrylic elastomers (a2), such as acrylic rubber particles (ar) and acrylic block copolymers (ab), is not particularly limited and is designed according to the form of the laminate, etc.

[0045] When the laminate of the present invention is a film, the acrylic elastomer (a2) content in the resin composition (A) can be made relatively high to ensure the flexibility, bending resistance, and flexibility required for a filter. When the laminate of the present invention is a film, in order to effectively achieve both the effect of improving impact resistance, flexibility, and bending resistance by stress concentration on the particles, and the suppression of void formation within the particles due to stress during bending, etc., and the resulting whitening, multiple types of acrylic rubber particles with different number-average particle diameters may be used in combination. For example, acrylic rubber particles with a number-average particle diameter of 180 to 300 nm (arx) and acrylic rubber particles with a number-average particle diameter of 50 to 170 nm (ary) can be used in combination. When the laminate of the present invention is a film, the content of the acrylic elastomer (a2) in the resin composition (A) is preferably 10 to 60% by mass, more preferably 30 to 50% by mass, and particularly preferably 40 to 50% by mass.

[0046] When the laminate of the present invention is a sheet, the content of the acrylic elastomer (a2) in the resin composition (A) can be kept relatively low, while ensuring the rigidity required for a sheet. When the laminate of the present invention is a sheet, the content of the acrylic elastomer (a2) in the resin composition (A) is preferably 2 to 40% by mass, more preferably 10 to 30% by mass, and particularly preferably 15 to 25% by mass.

[0047] The acrylic elastomer (a2) may contain acrylic rubber particles (ar). When acrylic rubber particles (ar) are used alone as the acrylic elastomer (a2), the preferred content of acrylic rubber particles (ar) in the resin composition (A) is as follows: When the laminate of the present invention is a film, the content of acrylic rubber particles (ar) in the resin composition (A) is preferably 10 to 60% by mass, more preferably 30 to 50% by mass, and particularly preferably 40 to 50% by mass. When the laminate of the present invention is a sheet, the content of acrylic rubber particles (ar) in the resin composition (A) is preferably 2 to 40% by mass, more preferably 10 to 30% by mass, and particularly preferably 15 to 25% by mass.

[0048] When using acrylic rubber particles (arx) with a number average particle size of 180-300 nm, acrylic rubber particles (ary) with a number average particle size of 50-170 nm, and an acrylic block copolymer (ab) as the acrylic elastomer (a2), the preferred content of these in the resin composition (A) is as follows. The content of acrylic rubber particles (arx) in the resin composition (A) is preferably 0.1 to 7.5% by mass, more preferably 0.5 to 7.0% by mass. If the content of acrylic rubber particles (arx) is less than 0.1% by mass, the additive effect will not be effectively exhibited, and if it exceeds 7.5% by mass, microscopic cracks may occur due to stress concentration around the acrylic rubber particles (ar), which may lead to stress whitening. The content of the acrylic block copolymer (ab) in the resin composition (A) is preferably 0.1% by mass or more and less than 5% by mass, more preferably 0.5 to 4.5% by mass. If the content of the acrylic block copolymer (ab) is less than 0.1% by mass, the additive effect will not be effectively exhibited, and if it is 5% by mass or more, the dispersed particle size of the acrylic block copolymer (ab) will increase, which may cause an increase in haze and stress whitening during bending, etc. The content of acrylic rubber particles (ary) in the resin composition (A) can be designed such that the total amount of acrylic elastomer (a2) in the resin composition (A) falls within the above preferred range.

[0049] An acrylic block copolymer (ab) may be used alone as the acrylic elastomer (a2). In this case, the content of the acrylic block copolymer (ab) in the resin composition (A) is preferably 2% by mass or more and less than 40% by mass, more preferably 10 to 30% by mass.

[0050] The resin composition (A) may optionally contain one or more polymers other than acrylic resins. The types of other polymers are not particularly limited and include polycarbonate resins, polyolefins such as polyethylene and polypropylene, other thermoplastic resins such as polyamides, polyphenylene sulfide, polyether ether ketone, polyester, polysulfone, polyphenylene oxide, polyimide, polyetherimide, and polyacetal; and thermosetting resins such as phenolic resins, melamine resins, silicone resins, and epoxy resins. The acrylic resin content in resin composition (A) is preferably high, preferably 90% by mass or more, more preferably 95% by mass or more, and particularly preferably 98% by mass or more. The content of other polymers in resin composition (A) is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 2% by mass or less.

[0051] The resin composition (A) may contain various additives as needed. Examples of additives include colorants, antioxidants, thermal degradation inhibitors, ultraviolet absorbers, light stabilizers, lubricants, mold release agents, polymer processing aids, antistatic agents, flame retardants, light diffusers, matting agents, and phosphors. The content of the additives can be appropriately set within a range that does not impair the effects of the present invention. For example, per 100 parts by mass of the constituent resin of the resin composition (A), the content of antioxidants is preferably 0.01 to 1 part by mass, the content of ultraviolet absorbers is preferably 0.01 to 3 parts by mass, the content of light stabilizers is preferably 0.01 to 3 parts by mass, and the content of lubricants is preferably 0.01 to 3 parts by mass. When other polymers and / or additives are added to resin composition (A), the timing of the addition may be during or after polymerization of the constituent resins of resin composition (A), or during the preparation of resin composition (A).

[0052] (Surface layer) The surface layer is a thermoplastic polyurethane resin-containing layer made of a resin composition (B) containing one or more thermoplastic polyurethane resins (b1). The surface layer is a layer that has scratch resistance and chemical resistance. The surface layer may also be a laminate of two or more thermoplastic polyurethane resin-containing layers. The thickness of the surface layer is not particularly limited, but is preferably 0.01 to 0.30 mm, more preferably 0.02 to 0.20 mm, and most preferably 0.02 to 0.10 mm. If the thickness of the surface layer is equal to or greater than the lower limit above, scratch resistance and chemical resistance are effectively exhibited, and the thickness in the width direction tends to be uniform when co-extruded with the base layer. If the thickness of the surface layer exceeds the upper limit above, the rigidity of the laminate of the present invention may decrease. Also, since the material of the surface layer is more expensive than the material of the base layer, from the viewpoint of cost reduction, it is preferable to design the thickness of the surface layer to be as thin as possible while maintaining good scratch resistance and chemical resistance. If the thickness of the surface layer is equal to or less than the upper limit above, the increase in cost due to material costs can be suppressed.

[0053] <Thermoplastic polyurethane resin (b1)> Polyurethane resins are resins having urethane bonds in their main chain. In this invention, one or more thermoplastic polyurethane resins (b1) having structural units derived from polyols and aliphatic diisocyanates are used as the polyurethane resin contained in the surface layer. Unlike the case in which a polyurethane resin-containing layer is formed using a hard coating agent or self-healing coating agent containing a thermosetting polyurethane resin, the laminate of the present invention, which uses a thermoplastic polyurethane resin (b1), can be manufactured by co-extrusion molding and can be produced at low cost with a small number of steps. Unlike thermosetting polyurethane resins, thermoplastic polyurethane resin (b1) has excellent stretchability, which allows for greater freedom in designing the shape of the laminate of the present invention when thermoforming it, making it preferable.

[0054] Generally, polyurethane resins are obtained by reacting one or more active hydrogen group-containing compounds having two or more active hydrogen groups with one or more polyisocyanates. In the present invention, since a thermoplastic polyurethane resin (b1) with good transparency can be obtained, a polyol having two or more hydroxyl groups is used as the active hydrogen group-containing compound. In the present invention, since a thermoplastic polyurethane resin (b1) with good transparency and weather resistance can be obtained, an aliphatic diisocyanate is used as the polyisocyanate having two or more isocyanate groups. The thermoplastic polyurethane resin (b1) obtained using polyol and aliphatic diisocyanate as raw materials exhibits good transparency and weather resistance, and yellowing is suppressed in weather resistance tests. In this invention, by using a thermoplastic polyurethane resin (b1) having structural units derived from polyols and aliphatic diisocyanates as the material for the surface layer, it is possible to form a surface layer with excellent scratch resistance and chemical resistance, as well as good transparency and weather resistance.

[0055] Thermoplastic polyurethane resin (b1) can be produced by known methods, and can be produced by reacting one or more polyols, one or more aliphatic diisocyanates, and optionally one or more chain extenders. For example, see Japanese Patent Application Publication No. 2007-217678.

[0056] Known polyols can be used, with adipate polyols, polycaprolactone polyols (PCL), polycarbonate polyols (PCD), polyethylene glycol (PEG), polypropylene glycol (PPG), and polymer polyols such as polytetramethylene glycol (PTMG) being preferred. For applications requiring heat resistance or oil resistance, adipate polyols, PCL, and PCD are preferred. Among these, PCD is more preferred from the viewpoint of hydrolysis resistance.

[0057] As the aliphatic diisocyanate, any known type can be used. The aliphatic diisocyanate may be alicyclic or non-alicyclic. Examples of non-alicyclic aliphatic diisocyanates include hexamethylene diisocyanate (HDI). Examples of alicyclic aliphatic diisocyanates (also called alicyclic diisocyanates) include hydrogenated 4,4-diphenylmethane diisocyanate (H 12 Examples include MDI, isophorone diisocyanate (IPDI), and 1,4-bis(isocyanatomethyl)cyclohexane (1,4H6XDI). Alicyclic aliphatic diisocyanates are preferred.

[0058] Examples of chain extenders include aliphatic glycols, aromatic glycols, 1,4-butanediol, 1,6-hexanediol, and low molecular weight diols such as bis(hydroxyethyl)hydroquinone.

[0059] The hardness (ShoreA) of the thermoplastic polyurethane resin (b1) is not particularly limited, but is preferably 85A or higher, more preferably 87A or higher. A hardness of 85A or higher is preferable because it suppresses surface tack of the laminate of the present invention, and allows the laminate to be wound up without a protective film during co-extrusion molding. The hardness of the thermoplastic polyurethane resin (b1) can be measured in accordance with the hardness test of JIS-K7311-1995.

[0060] The weight-average molecular weight (Mw) of the thermoplastic polyurethane resin (b1) is not particularly limited, but from the viewpoint of heat resistance, it is preferably 5.0 × 10 4 The above is a comfortable 7.0 × 10 4 The above is particularly preferable to 1.0 × 10 5 That concludes the explanation. From the viewpoint of moldability, 1.0 × 10 is preferred. 6 More preferably 9.0 × 10 5 The following is particularly preferred: 7.0 × 10 5 The following applies: In this specification, unless otherwise specified, "weight-average molecular weight (Mw)" is measured by the GPC method and is the value obtained by converting the chromatogram measured by GPC to the molecular weight of standard polystyrene.

[0061] The melt mass flow rate (MFR) of the thermoplastic polyurethane resin (b1), measured at 220°C and a load of 2.16 kg, is not particularly limited, but is preferably 1 to 100 g / 10 min, more preferably 2 to 90 g / 10 min, and most preferably 3 to 80 g / 10 min. If the MFR is above the lower limit, good moldability can be obtained, and if it is below the upper limit, uneven lamination due to the difference in melt viscosity with the acrylic resin is less likely to occur. In this specification, MFR can be measured in accordance with JIS K7210.

[0062] <Thermoplastic resin (b2)> The resin composition (B) may optionally include thermoplastic resins other than thermoplastic polyurethane resins and acrylic rubber particles (b2). Known thermoplastic resins (b2) can be used, including homopolymers or copolymers of methacrylic acid esters, methacrylic acid ester-styrene copolymers (MS resins), styrene-maleic anhydride copolymers (SMA resins), styrene-methacrylic acid ester-maleic anhydride copolymers (SMM resins), acrylonitrile-styrene copolymers (AS resins), polycarbonate resins, polyolefins such as polyethylene and polypropylene, polyamides, polyphenylene sulfide, polyether ether ketones, polyesters, polysulfones, polyphenylene oxides, polyimides, polyetherimides, and polyacetals. One or more of these can be used.

[0063] From the viewpoint of the transparency of the resin composition (B) and the laminate of the present invention, it is preferable that the thermoplastic resin (b2) has a refractive index close to that of the thermoplastic polyurethane resin (b1). Specifically, the refractive index of the thermoplastic polyurethane resin (b1) is n b1 The refractive index n of the thermoplastic resin (b2) b2 In this case, it is preferable that the following equation (2) is satisfied. |n b1 -n b2 |≦0.005...Equation (2) |n b1 -n b2 The value of | is more preferably 0.003 or less, and particularly preferably 0.002 or less. The refractive index of the resin can be measured by the method described in the [Examples] section below.

[0064] When the surface layer contains a thermoplastic resin (b2), selecting one with a small refractive index difference from the thermoplastic polyurethane resin (b1) can improve the transparency of the surface layer. Since the refractive index is close to that of the polyurethane resin (b1), methacrylic resins such as polymethyl methacrylate (PMMA), copolymers of methyl methacrylate (MMA) and one or more (meth)acrylic acid esters, and MS resins are preferred as the thermoplastic resin (b2).

[0065] <Acrylic rubber particles (b3)> The resin composition (B) may optionally contain acrylic rubber particles (b3) having an alkyl acrylate copolymer layer. When the resin composition (B) contains acrylic rubber particles (b3), the impact resistance, flexural resistance, and bending resistance of the laminate of the present invention can be improved. The acrylic rubber particles (b3) are preferably multilayer rubber particles with a core-shell structure, consisting of an interior containing one or more rubber component layers and an exterior consisting of one or more thermoplastic resin component layers. The interior of the acrylic rubber particles (b3) consists of a core and, optionally, one or more intermediate layers. The number of layers of the acrylic rubber particles (b3) is two or more, and may be three or four or more. The upper limit of the number of layers is, for example, five. As for the acrylic rubber particles (b3), from the viewpoint of physical properties and ease of manufacture, multilayer polymer particles with a three-layer structure consisting of a first thermoplastic resin component layer (core), a rubber component layer (intermediate layer), and a second thermoplastic resin component layer from the center are preferred.

[0066] The mass ratio (rubber component layer / thermoplastic resin component layer) of the total amount of the rubber component layer to the total amount of the thermoplastic resin component layer is preferably 30 / 70 to 90 / 10. If the proportion of the rubber component layer is equal to or greater than the lower limit, the effects of improving the impact resistance, flexibility, and bending resistance of the laminate of the present invention can be effectively obtained. If the proportion of the rubber component layer exceeds the upper limit, it becomes difficult to form a particle structure, and the melt fluidity decreases, which may make it difficult to knead with other components and mold the resin composition (B).

[0067] The rubber component layer preferably contains a copolymer comprising 50 to 98.99% by mass of acrylic acid ester units, 44.99 to 1% by mass of other monofunctional monomer units, and 0.01 to 10% by mass of polyfunctional monomer units. The thermoplastic resin component layer preferably contains a copolymer consisting of 40 to 100% by mass of methacrylic acid ester units and 60 to 0% by mass of other monomer units. Examples of raw material monomers for the rubber component layer and the thermoplastic resin component layer are the same as those for acrylic rubber particles (ar).

[0068] The number-average particle diameter of the acrylic rubber particles (b3) is not particularly limited, but is preferably 50 to 300 nm. If the number-average particle diameter is greater than or equal to the lower limit, stress concentration on the acrylic rubber particles (b3) occurs effectively, and the effects of improving the impact resistance, flexibility, and bending resistance of the laminate of the present invention are effectively obtained. If the number-average particle diameter exceeds the upper limit, voids may be generated within the acrylic rubber particles (b3) due to stress during bending, etc., which may cause whitening.

[0069] To effectively achieve both improved impact resistance, flexural resistance, and bending resistance through stress concentration on the particles, and suppression of void formation within the particles due to stress and the resulting whitening, multiple types of acrylic rubber particles (b3) with different number-average particle sizes can be used in combination. For example, the acrylic rubber particles (b3) can include acrylic rubber particles (b3x) with a number-average particle size of 180-300 nm and acrylic rubber particles (b3y) with a number-average particle size of 50-170 nm.

[0070] From the viewpoint of the transparency of the resin composition (B) and the laminate of the present invention, it is preferable that the acrylic rubber particles (b3) have a refractive index close to that of the thermoplastic polyurethane resin (b1). Specifically, the refractive index n of the acrylic rubber particles (b3) b3 In this case, it is preferable that the following equation (3) is satisfied. |n b1 -n b3 |≦0.005...Equation (3) |n b1 -n b3 The value of | is more preferably 0.003 or less, particularly preferably 0.002 or less, and most preferably 0.001 or less. When the surface layer contains acrylic rubber particles (b3), selecting a material with a small refractive index difference from the thermoplastic polyurethane resin (b1) can improve the transparency of the surface layer.

[0071] The resin composition (B) may contain various additives as needed. Examples of additive types and preferred amounts are the same as those for the additives usable in resin composition (A). When an additive is added to the resin composition (B), the timing of the addition may be during or after the polymerization of the constituent resins of the resin composition (B), or it may be during the preparation of the resin composition (B).

[0072] (Other resin layers) The laminate of the present invention may have other resin layers besides the base layer and the surface layer. Examples of the laminate structure of the laminate of the present invention include a two-layer structure of surface layer-base layer; a three-layer structure of surface layer-base layer-surface layer, other resin layer-surface layer-base layer, surface layer-base layer, and other resin layer; a four-layer structure of other resin layer-surface layer-base layer-surface layer, and other resin layer; and a five-layer structure of other resin layer-surface layer-base layer-surface layer. From the viewpoint of scratch resistance and chemical resistance, it is preferable that at least one of the outermost layers of the laminate of the present invention is a surface layer containing a thermoplastic polyurethane resin (b1).

[0073] [Method for manufacturing laminates] The laminate of the present invention, having a laminated structure of a base layer and a surface layer, can be molded using known methods such as extrusion molding and hot press molding. Among these, extrusion molding (also called melt extrusion) is preferred, and co-extrusion molding is particularly preferred from the viewpoint of productivity. The following describes the method for manufacturing the laminate of the present invention by co-extrusion molding. Figure 3 shows a schematic diagram of an extrusion molding apparatus, as one embodiment, which includes a T-die 11, first to third cooling rolls 12 to 14, and a pair of take-up rolls 15. Each layer material (resin composition) is melt-kneaded using an extruder and co-extruded in the form of a film or sheet from a T-die 11 having a wide discharge port in the desired laminated structure. Lamination methods include a feed block method where the material is laminated before it enters the T-die, and a multi-manifold method where the material is laminated inside the T-die. From the viewpoint of improving inter-layer interface smoothness, the multi-manifold method is preferred. It is preferable to extrude the molten material (resin composition) of each layer from a T-die while filtering it to remove nuclei and impurities that cause surface defects. A screen mesh of 200 mesh or more is preferred as the filter. The molten thermoplastic resin laminate co-extruded from the T-die 11 is pressurized and cooled using the first to third cooling rolls 12 to 14. The laminate (film or sheet) 16 obtained after pressurization and cooling is taken up by a pair of take-up rolls 15. The number of cooling rolls can be designed as appropriate. The configuration of the manufacturing apparatus can be modified as appropriate without departing from the spirit of the present invention. The temperature of the T-die 11 (extrusion molding temperature) is not particularly limited, but is preferably 200 to 240°C. If the temperature of the T-die 11 is 200°C or higher, both the base layer material and the surface layer material can be brought to a good melted state. If the temperature of the T-die 11 is 240°C or lower, thermal degradation of the base layer material and the surface layer material can be suppressed.

[0074] Other preferred manufacturing methods for the laminate of the present invention besides the co-extrusion molding method include: A method of forming a base layer and a surface layer into a film or sheet by extrusion molding using a T-die, and then laminating the film or sheet made of the base layer and the film or sheet made of the surface layer by a thermal lamination method; Examples include an extrusion lamination method in which one of the base layer and the surface layer is formed into a film or sheet by an extrusion molding method using a T-die, and the other layer is laminated onto the resulting film or sheet by an extrusion molding method.

[0075] The laminate of the present invention, which is in the form of a film or sheet, obtained by the above method may be thermoformed. The thermoforming process may include, for example, a step of heating the film or sheet, a step of pressing a mold onto the heated film or sheet, a step of cooling the film or sheet in the mold, and a step of removing the cooled film or sheet from the mold. In the laminate of the present invention, a thermoplastic polyurethane resin with excellent stretchability is used as the surface layer material instead of a thermosetting polyurethane resin, which is preferable because it allows for greater freedom in designing the shape when thermoforming the laminate of the present invention. Furthermore, laminates of any shape obtained after thermoforming a film-like or sheet-like laminate of the present invention are also included in the laminates of the present invention.

[0076] The laminate of the present invention includes a laminated structure comprising a base layer made of a resin composition (A) containing an acrylic resin and a surface layer made of a resin composition (B) containing a thermoplastic polyurethane resin (b1) having structural units derived from a polyol and an aliphatic diisocyanate. The laminate of the present invention has excellent scratch resistance and chemical resistance because its surface layer contains a thermoplastic polyurethane resin. In the laminate of the present invention, the temperature of resin composition (A) and resin composition (B) is 220°C and the shear rate is 50 s. -1 The melt viscosity measured under the following conditions is η A η BIn this case, the compositions of resin composition (A) and resin composition (B) are designed to satisfy the above formula (1). This improves the uniformity of the thickness ratio between the base layer and the surface layer, improves the uniformity of the thickness of the surface layer, and suppresses interface roughness between the base layer and the surface layer.

[0077] Since the base layer is made of an acrylic resin composition, it can possess the inherent properties of acrylic resins, such as transparency, weather resistance, and surface hardness. By using a thermoplastic polyurethane resin (b1) having structural units derived from polyols and aliphatic diisocyanates as the material for the surface layer, a surface layer with good scratch resistance, chemical resistance, transparency, and weather resistance can be formed. When the surface layer contains thermoplastic polyurethane resin and thermoplastic rubber particles other than thermoplastic polyurethane resin (b2), the transparency of the surface layer can be improved by selecting a thermoplastic polyurethane resin (b1) with a small refractive index difference. When the surface layer contains acrylic rubber particles (b3), selecting a material with a small refractive index difference from the thermoplastic polyurethane resin (b1) can improve the transparency of the surface layer.

[0078] As described above, according to the present invention, it is possible to provide a laminate comprising an acrylic resin-containing layer and a thermoplastic polyurethane resin-containing layer, wherein the thickness uniformity of the thermoplastic polyurethane resin-containing layer is good, interface roughness between the acrylic resin-containing layer and the thermoplastic polyurethane resin-containing layer is suppressed, and the laminate has excellent scratch resistance and chemical resistance. According to the present invention, it is possible to provide a laminate with good transparency, weather resistance, and surface hardness in accordance with the above-mentioned properties.

[0079] [Application] The laminate of the present invention can be used for a variety of applications. Specific applications include sign parts, marking films, display parts, lighting parts, interior parts, building parts, transportation equipment parts such as automotive interior / exterior components, electronic equipment parts, medical equipment parts, various equipment parts, optical components, traffic-related components, bathroom components, and surface materials. [Examples]

[0080] Examples and comparative examples of the present invention will be described below. [Evaluation items and evaluation methods] (Weight average molecular weight (Mw)) The weight-average molecular weight (Mw) of the resin was determined by GPC using the following procedure. A Tosoh Corporation HLC-8320 (model number) equipped with a differential refractive index detector (RI detector) was used as the GPC instrument. Tetrahydrofuran (THF) was used as the eluent. A column consisting of two Tosoh Corporation "TSKgel SuperMultipore HZM-M" columns and a "SuperHZ4000" column connected in series was used. A sample solution was prepared by dissolving 4 mg of resin in 5 ml of THF. The column oven temperature was set to 40°C, and 20 μl of the sample solution was injected at an eluent flow rate of 0.35 ml / min. The chromatogram was then measured. GPC measurements were performed on 10 standard polystyrene samples with molecular weights in the range of 400 to 5,000,000, and a calibration curve showing the relationship between retention time and molecular weight was created. Mw was determined based on this calibration curve.

[0081] (Melting viscosity η) A η B ) The melt viscosity of resin composition (A) or (B) was measured using a capillary rheometer (Capillograph 1D, manufactured by Toyo Seiki Seisakusho Co., Ltd.). At 220°C, the piston speed was varied, and resin composition (A) or (B) was extruded from a capillary with a diameter of 1 mmφ and a length of 40 mm. The viscosity was measured from the shear stress generated during this process. The shear rate and viscosity data were plotted in two dimensions, and η A or η B For example, shear rate 50s -1The melt viscosity was determined under these conditions.

[0082] (refractive index n) b1 , n b2 , n b3 ) The refractive index of thermoplastic polyurethane resin (b1), thermoplastic resin (b2), or acrylic rubber particles (b3) was measured as follows. An evaluation sheet measuring 12mm x 12mm with a thickness of 3mm was prepared by press molding the resin to be measured. The refractive index was measured using the KPR-20 from Carnew Optical Industry Co., Ltd. at 25°C and a measurement wavelength of 587.6nm (d-line).

[0083] (Hardness of thermoplastic polyurethane resin (b1)) The hardness (Shore A) of thermoplastic polyurethane resin (b1) was measured in accordance with the hardness test specified in JIS K7311-1995.

[0084] (Number-average particle size of acrylic rubber particles) Acrylic rubber particle powder was heat-pressed at 230°C to obtain a 100 μm thick film. Ultrathin sections of 80 nm thickness were prepared using an ultramicrotome (Leica EM UC7rt, JEOL Ltd.). The prepared ultrathin sections were stained with a 10% phosphotungstic acid aqueous solution, and the morphology of the stained particles containing one or more rubber component layers was observed using a scanning transmission electron microscope (JEOL Ltd., main unit: JSM-7600F, detector: SM-74240RTED). The particle diameters of 30 stained particles were measured, and their average values ​​were calculated to determine the number-average particle diameter of the acrylic rubber particles.

[0085] (Uniformity of surface layer thickness) The thickness distribution of the surface layer in the cross-section in the width direction of the laminate was measured using a Nikon Instec "Universal Projector (V-12B)". The thickness of the surface layer was measured in the cross-section (width 300 mm) of the laminate in the width direction, specifically at the central section (150 mm from one end) and the end section (30 mm from one end). The thickness ratio of the central section to the end section (thickness of the central section / thickness of the end section) was calculated. The closer this thickness ratio is to 1.0, the higher and better the thickness uniformity of the surface layer in the width direction.

[0086] (Interface roughness) The interface between the substrate layer and the surface layer was visually observed from the surface layer side of the laminate, and the roughness of the interface between the substrate layer and the surface layer was evaluated according to the following criteria. A (Good): No interface roughness, and the appearance is good. C (Defective): The interface is rough and the appearance is poor.

[0087] (transparency) The haze of the laminate (initial haze before the abrasion test described later) was measured using a haze meter (HAZE METER HM-150, Murakami Color Technology Laboratory Co., Ltd.).

[0088] (Scratch resistance) A Taber abrasion test was performed on the surface layer in accordance with JIS K7204. A CS-10F abrasion wheel was used, and the test was conducted under conditions of a load of 4.9N, a rotation speed of 60rpm, and 1000 cycles. The haze of the laminate after the test was measured using the same method as described above, and the difference in haze before and after the test (ΔHaze) was determined.

[0089] (Chemical resistance) The laminate was cut to obtain a 60mm x 60mm test specimen. 0.2 mL of 10% lactic acid aqueous solution or 2.5 g of sunscreen (Bayer's "Coppetone SPORT LOTION SPF30") was dropped onto the surface layer of this specimen as a chemical. The specimen was placed in an oven and heated at 80°C for 24 hours. The specimen was removed from the oven. If sunscreen was used as the chemical, any remaining sunscreen on the surface of the specimen was wiped off with gauze containing deionized water. After these procedures, the appearance of the laminate was visually inspected and evaluated according to the following criteria. Evaluation criteria (in the case of lactic acid solution) A (Good): No chemical traces were observed on the surface of the test specimen, and no delamination between the substrate layer and the surface layer was observed. B (Acceptable): Chemical residue was observed on the surface of the test specimen, but no delamination between the substrate layer and the surface layer was observed. C (Poor): Swelling was observed on the surface of the test specimen, and delamination between the substrate layer and the surface layer was observed. Evaluation criteria (for sunscreen) A (Good): The sunscreen could be wiped off with gauze, and no whitening was observed on the surface of the test specimen. B (Acceptable): The sunscreen could be wiped off with gauze, but whitening was observed on the surface of the test piece. C (Defective): The laminate and sunscreen were fused together, making it impossible to wipe off the sunscreen with gauze.

[0090] [Materials of resin composition (A)] <Methacrylic resin (a1)> (a1-1) Polymethyl methacrylate (PMMA), manufactured by Kuraray Co., Ltd., "Parapet (registered trademark) EH", MFR (measured at a temperature of 230°C and a load of 3.8 kg) = 1.3 g / 10 min.

[0091] <Acrylic rubber particles (ar)> (arx-1) Acrylic rubber particles (arx-1) with a three-layer structure were produced by sequentially forming the innermost layer, intermediate layer, and outermost layer from copolymers with the following compositions. The number-average particle size was 230 nm. Innermost layer: Methyl methacrylate (MMA) units / Methyl acrylate (MA) units / Allyl methacrylate units (crosslinkable monomer) (mass ratio) = 32.91 / 2.09 / 0.07 Intermediate layer: Butyl acrylate units / styrene units / crosslinkable monomer allyl methacrylate units (mass ratio) = 37.00 / 8.00 / 0.90 Outermost layer: Methyl methacrylate (MMA) units / Methyl acrylate (MA) units (mass ratio) = 18.80 / 1.20.

[0092] (ary-1) Acrylic rubber particles (ary-1) with a three-layer structure were produced by sequentially forming the innermost layer, intermediate layer, and outermost layer from copolymers with the following compositions. The number-average particle size was 110 nm. Innermost layer: Methyl methacrylate (MMA) units / Methyl acrylate (MA) units / Allyl methacrylate units (crosslinkable monomer) (mass ratio) = 9.39 / 0.61 / 0.02 Intermediate layer: Butyl acrylate units / styrene units / crosslinkable monomer allyl methacrylate units (mass ratio) = 41.11 / 8.89 / 2.00 Outermost layer: Methyl methacrylate (MMA) units / Methyl acrylate (MA) units (mass ratio) = 37.61 / 2.39.

[0093] <Acrylic block copolymer (ab)> (ab-1) Acrylic triblock copolymer, methyl methacrylate (MMA) polymer block / butyl acrylate polymer block / methyl methacrylate (MMA) polymer block (mass ratio) = 14.3 / 50.0 / 35.7, weight-average molecular weight (Mw) = 70,000.

[0094] [Manufacturing Examples 11-13] Manufacturing of resin composition (A) The resin compositions (A-1) to (A-3) were obtained by melting and kneading one or more materials at 230°C according to the formulations shown in Table 1, and then pelletizing them. The formulations and melt viscosity η of the obtained resin compositions are as follows. A This is shown in Table 1. The unit of composition is "parts by mass".

[0095] [Table 1]

[0096] [Materials for resin composition (B)] <Thermoplastic polyurethane resin (b1)> (TPU-1) XCT-1095A, manufactured by FCI Corporation, is a polyurethane resin obtained using polycarbonate polyol (PCD) and 1,4-bis(isocyanatomethyl)cyclohexane (1,4H6XDI), an alicyclic aliphatic diisocyanate. It has a refractive index of 1.490 and a hardness of 95A. (TPU-2) FCI Corporation's "NY585N11A" is an adipate polyol and hydrogenated 4,4-diphenylmethane diisocyanate (H 12 A polyurethane resin obtained using MDI, with a refractive index of 1.490 and a hardness of 86A. (TPU-2) FCI Corporation's "NY988-10HB2" contains polycaprolactone polyol (PCL) and hydrogenated 4,4-diphenylmethane diisocyanate (H), an alicyclic aliphatic diisocyanate. 12 A polyurethane resin obtained using MDI, with a refractive index of 1.490 and a hardness of 97A.

[0097] <Thermoplastic resin (b2)> (b2-1) Polymethyl methacrylate (PMMA), manufactured by Kuraray Co., Ltd., "Parapet (registered trademark) HR-S", MFR (measured at a temperature of 230°C and a load of 3.8 kg) = 2.4 g / 10 min). (b2-2) Methyl methacrylate (MMA)-styrene copolymer, "Toyo MS600" manufactured by Toyo Styrene Co., Ltd., MFR (measured at a temperature of 200°C and a load of 49N) = 1.0g / 10min.

[0098] <Acrylic rubber particles (b3)> (b3-1) Acrylic rubber particles (b3-1) with a three-layer structure were produced by sequentially forming the innermost layer, intermediate layer, and outermost layer from copolymers with the following compositions. The number-average particle size was 100 nm. Innermost layer: Methyl methacrylate (MMA) units / Butyl acrylate (BA) units / Styrene units / Allyl methacrylate units (crosslinkable monomer) (mass ratio) = 14.11 / 30.00 / 5.89 / 0.02 Intermediate layer: Methyl methacrylate (MMA) units / Butyl acrylate (BA) units / Styrene units / Allyl methacrylate units (crosslinkable monomer) (mass ratio) = 1.03 / 20.00 / 3.97 / 0.1 Outermost layer: Methyl methacrylate (MMA) units / Methyl acrylate (MA) units (mass ratio) = 23.75 / 1.25.

[0099] [Manufacturing Examples 21-28] Manufacturing of resin composition (B) The resin compositions (B-1) to (B-8) were obtained by melting and kneading one or more materials at 230°C according to the formulations shown in Table 2, and then pelletizing them. The formulations and melt viscosity η of the obtained resin compositions are as follows. B This is shown in Table 2. The unit of composition is "parts by mass".

[0100] [Table 2]

[0101] [Examples 1-17, Comparative Examples 2, 3] A resin for the base layer (resin composition (A)) was melt-extruded using a 50 mmφ single-screw extruder (manufactured by Toshiba Machine Co., Ltd.). A resin for the surface layer (resin composition (B)) was melt-extruded using a 30 mmφ single-screw extruder (manufactured by Toshiba Machine Co., Ltd.). These molten resins were laminated via a multi-manifold die, and a two-layer thermoplastic resin laminate was co-extruded from a T-die (width: 400 mm). The two-layer resin in a molten state was discharged from the T-die, sandwiched between two adjacent first and second cooling rolls, wrapped around the second cooling roll, sandwiched between the second and third cooling rolls, wrapped around the third cooling roll, and cooled, then taken up by a pair of take-up rolls. In this way, a two-layer film or sheet (laminated, width: 300 mm) consisting of a base layer and a surface layer was obtained. For each example, the main manufacturing conditions and evaluation results are shown in Tables 3 and 4. In the example shown in Table 3, conditions not listed in the table were considered common conditions. In Table 3, the total thickness is the measured value, while the thickness of each layer is calculated from the measured total thickness and the extrusion ratio of each resin.

[0102] [Comparative Example 1] A 50mmφ single-screw extruder (manufactured by Toshiba Machine Co., Ltd.) was used to melt-extrude the resin for the base layer (resin composition (A)). The molten, single-layer resin was extruded from a T-die, sandwiched between adjacent first and second cooling rolls, wrapped around the second cooling roll, sandwiched between the second and third cooling rolls, wrapped around the third cooling roll, and cooled, before being taken up by a pair of take-up rolls. In this way, a single-layer sheet (width: 300mm) consisting only of the base layer was obtained. The main manufacturing conditions and evaluation results are shown in Tables 3 and 4.

[0103] [Table 3]

[0104] [Table 4]

[0105] [Summary of results] In Examples 1 to 17 and Comparative Examples 2 and 3, a film or sheet (laminated) was produced consisting of a base layer made of a resin composition (A) containing an acrylic resin and a surface layer made of a resin composition (B) containing a thermoplastic polyurethane resin (b1) having structural units derived from polyols and aliphatic diisocyanates. In Comparative Example 1, a single-layer sheet was manufactured consisting only of a base layer made of a resin composition (A) containing an acrylic resin.

[0106] In Examples 1-17, η B / η A The compositions of resin composition (A) and resin composition (B) were designed so that the ratio was between 0.03 and 2.00. In these examples, it was possible to obtain a film or sheet with good thickness uniformity of the surface layer, suppression of interface roughness between the substrate layer and the surface layer, and excellent scratch resistance and chemical resistance.

[0107] In Examples 1, 4, 7, 10, 13, and 14, where the surface layer consisted solely of thermoplastic polyurethane resin (b1), highly transparent films or sheets were obtained. In Examples 2, 5, 8, 11, and 15, where the surface layer consisted of a thermoplastic polyurethane resin (b1) and a thermoplastic resin (b2), and the thermoplastic resin (b2) had a small refractive index difference with the thermoplastic polyurethane resin (b1), highly transparent films or sheets were obtained. In Examples 3, 6, 9, 12, and 16, where the surface layer consisted of a thermoplastic polyurethane resin (b1) and acrylic rubber particles (b3), and acrylic rubber particles (b3) with a small refractive index difference from the thermoplastic polyurethane resin (b1) were used, highly transparent films or sheets were obtained.

[0108] In Examples 2, 5, 8, 11, and 15, which used a resin composition (B-2) or (B-5) consisting of a polymer alloy of a thermoplastic polyurethane resin (b1) and PMMA (linear polymethyl methacrylate) as the surface layer material, the chemical resistance when using an aqueous lactic acid solution as the chemical was excellent (rated A). The PMMA used had a high glass transition temperature (Tg) of 110°C, and its chemical resistance when used alone with an aqueous lactic acid solution was excellent (rated A), so the polymer alloy also performed well (rated A).

[0109] The PMMA single-layer sheet obtained in Comparative Example 1 exhibited poor scratch resistance and poor chemical resistance when sunscreen was used as the chemical. In comparative examples 2 and 3, η B / η A Because the value was less than 0.03, there was a large difference in melt viscosity between the base layer material and the surface layer material. As a result, the obtained film or sheet had poor thickness uniformity of the surface layer and roughness at the interface between the base layer and the surface layer.

[0110] The present invention is not limited to the embodiments and examples described above, and design modifications can be made as appropriate without departing from the spirit of the invention.

[0111] This application claims priority based on Japanese Patent Application No. 2021-077576, filed on 30 April 2021, and incorporates all of its disclosures herein. [Explanation of symbols]

[0112] 1, 2 laminated 21 Base material layer 22 Surface layer

Claims

1. The structure comprises a laminated structure consisting of a base layer made of a resin composition (A) containing an acrylic resin and a surface layer made of a resin composition (B) containing a thermoplastic polyurethane resin (b1) having structural units derived from a polyol and an aliphatic diisocyanate. The resin composition (B) further comprises a thermoplastic resin (b2) other than a thermoplastic polyurethane resin and acrylic rubber particles. Resin composition (A) and resin composition (B) were subjected to a temperature of 220°C and a shear rate of 50 s. －１ The melt viscosity measured under the following conditions is η Ａ η Ｂ When this is the case, the following equation (1) is satisfied, A laminate that satisfies the following formula (2), where the refractive index of thermoplastic polyurethane resin (b1) is n b1 and the refractive index of thermoplastic resin (b2) is n b2. 0.05≦h Ｂ / or Ａ ≦0.50・・・expression (1) |n b1 -n b2 |≦0.005...Formula (2)

2. The laminate according to claim 1, satisfying the following formula. 0.05≦η B / η A ≦0.41

3. The laminate according to claim 1, wherein the thermoplastic resin (b2) is one or more methacrylic resins selected from the group consisting of polymethyl methacrylate, copolymers of methyl methacrylate and one or more (meth)acrylic acid esters, and methyl methacrylate-styrene copolymers.

4. The laminate according to claim 1, wherein the resin composition (B) further comprises acrylic rubber particles (b3).

5. The refractive index of the thermoplastic polyurethane resin (b1) is n ｂ１ The refractive index of the acrylic rubber particles (b3) is set to n ｂ３ The laminate according to claim 4, which satisfies the following formula (3). |n ｂ１ -n ｂ３ |≦0.005・・・Form (3)

6. The laminate according to claim 1, wherein the resin composition (A) comprises a methacrylic resin (a1) and an acrylic elastomer (a2).

7. The laminate according to claim 6, wherein the acrylic elastomer (a2) comprises acrylic rubber particles (arx) having a number average particle diameter of 180 to 300 nm and acrylic rubber particles (ary) having a number average particle diameter of 50 to 170 nm.

8. The laminate according to claim 6, wherein the acrylic elastomer (a2) comprises an acrylic block copolymer (ab).

9. The laminate according to claim 1, wherein the total thickness is 0.03 mm or more and less than 0.50 mm.

10. The laminate according to claim 1, wherein the total thickness is 0.50 mm or more and 8.00 mm or less.

11. A method for manufacturing a laminate, comprising producing the laminate described in claim 1 by co-extrusion molding.

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