Resin compositions, flat molded bodies, multilayer bodies, and molded articles

Abstract

To provide a resin composition capable of providing a multilayer body which has excellent transparency and suppresses warpage after a wet heat test, and to provide a flat plate-shaped molding, a multilayer body, and a molded article.SOLUTION: The resin composition contains 70-10 pts.mass of a copolymer (B) based on 30-90 pts.mass of a copolymer (A). The copolymer (A) contains 36-96 mass% of a (meth)acrylic monomer unit, 0-60 mass% of an aromatic vinyl monomer unit, and 3-64 mass% in total of a cyclic acid anhydride unit and / or an N-substituted maleimide monomer unit. The copolymer (B) contains 70-90 mass% of an aromatic vinyl monomer unit and 10-30 mass% of an alkenyl cyanide monomer unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to resin compositions, plate-shaped molded articles, multilayer articles, and molded articles. [Background technology]

[0002] Acrylic resin is used in many applications as an optical material due to its excellent transparency, moldability, and surface hardness. However, because acrylic resin has poor material toughness, it is often co-extruded with polycarbonate resin, which has excellent transparency and material toughness, to produce multilayer materials such as multilayer films and sheets. For example, Patent Document 1 discloses a resin laminate characterized in that a thermoplastic resin layer containing a copolymer of a cyanide alkenyl monomer and a styrene monomer as a resin component is laminated on at least one surface of a polycarbonate resin layer. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2014-124786 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Here, it was found that when a copolymer of a cyanide alkenyl monomer and a styrene monomer is blended with methacrylic resin, the resulting flat molded articles may have poor transparency. In addition, co-extruded multilayer materials of acrylic resin and polycarbonate resin may present problems in suppressing warping after humid heat testing. The present invention aims to solve the aforementioned problems and to provide a resin composition, a plate-shaped molded body, a multilayer body, and a molded article that can provide a multilayer body with excellent transparency and suppressed warping after a humid heat test. [Means for solving the problem]

[0005] Based on the above problems, the inventors conducted research and found that the above problems can be solved by blending two predetermined copolymers. Specifically, the above problem was solved by the following means. <1> A resin composition comprising 30 to 90 parts by mass of copolymer (A) and 70 to 10 parts by mass of copolymer (B), wherein copolymer (A) is a copolymer containing 36 to 96% by mass of (meth)acrylic monomer units, 0 to 60% by mass of aromatic vinyl monomer units, and a total of 3 to 64% by mass of cyclic acid anhydride units and / or N-substituted maleimide monomer units, and copolymer (B) is a copolymer containing 70 to 90% by mass of aromatic vinyl monomer units and 10 to 30% by mass of cyanide alkenyl monomer units. <2> The copolymer (A) is a copolymer comprising 36 to 96% by mass of (meth)acrylic monomer units, 1 to 60% by mass of aromatic vinyl monomer units, and a total of 3 to 63% by mass of cyclic acid anhydride units and / or N-substituted maleimide monomer units. <1> The resin composition described above. <3> The haze of the resin composition when it is molded to a thickness of 1 mm is 5.0% or less. <1> or <2> The resin composition described above. <4> The refractive index is 1.54 or higher. <1> ~ <3> A resin composition as described in any one of the following. <5> The onset glass transition temperature (TIG) determined by differential scanning calorimetry is 115°C or higher. <1> ~ <4> A resin composition as described in any one of the following. <6> The resin composition is molded to a thickness of 1 mm, and the pencil hardness measured using a pencil hardness tester in accordance with JIS K5600-5-4:1999 under a 750 g load is F or higher. <1> ~ <5> A resin composition as described in any one of the following. <7> The melt mass flow rate (MFR) at 230°C and a load of 3.8 kg is 1.0 g / 10 min or higher. <1> ~ <6> A resin composition as described in any one of the following. <8>Furthermore, the resin composition according to any one of <1> to <7>, which contains a total of 0.001 to 0.5 parts by mass of an antioxidant and / or a mold release agent with respect to 100 parts by mass of the resin composition. <9>A flat molded body formed from the resin composition according to any one of <1> to <8>. <10>A multilayer body including the flat molded body according to <9> and at least one other layer. <11>The multilayer body according to <10>, wherein the at least one other layer is a layer containing a polycarbonate resin. <12>The multilayer body according to <11>, wherein the initial glass transition temperature (Tig) according to the differential scanning calorimetry of the polycarbonate resin is 130°C or lower. <13>The multilayer body according to <11> or <12>, wherein the polycarbonate resin has a terminal structure represented by the formula (1).

Chemical formula

Advantages of the Invention

[0006] According to the present invention, it has become possible to provide a resin composition, a flat molded body, a multilayer body, and a molded article that are excellent in transparency and have warpage after a damp heat test suppressed.

Brief Description of the Drawings

[0007] [Figure 1] FIG. 1 is a diagram schematically showing the layer structure of the multilayer body of the present invention.

Modes for Carrying Out the Invention

[0008] Hereinafter, modes for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the following present embodiment is an exemplification for explaining the present invention, and the present invention is not limited only to the present embodiment. In this specification, "~" is used to mean including the numerical values described before and after it as lower and upper limits. In this specification, unless otherwise specified, various physical property values and characteristic values are those at 23°C. In the notation of groups (atomic groups) in this specification, a notation without indicating substitution or non-substitution includes both a group (atomic group) having no substituent and a group (atomic group) having a substituent together with the group having no substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). In this specification, a notation without indicating substitution or non-substitution is preferably unsubstituted. In this specification, the (meth)allyl group represents both allyl and methallyl, or either one, "(meth)acrylate" represents both acrylate and methacrylate, or either one, and "(meth)acrylic" represents both acrylic and methacrylic, or either one. The flat molded body and the multilayer body in this specification are each intended to include those having the shape of a film or a sheet. The "flat molded body" refers to a molded body that is thin in thickness and generally flat with respect to its length and width. Also, the "flat molded body" in this specification may be single-layered or multi-layered. If the measurement methods, etc., described in the standards shown herein differ from year to year, unless otherwise specified, the standards as of November 1, 2021 shall apply.

[0009] The resin composition of this embodiment comprises 30 to 90 parts by mass of copolymer (A) and 70 to 10 parts by mass of copolymer (B), wherein copolymer (A) is a copolymer containing 36 to 96% by mass of (meth)acrylic monomer units, 0 to 60% by mass of aromatic vinyl monomer units, and a total of 3 to 64% by mass of cyclic acid anhydride units and / or N-substituted maleimide monomer units, and copolymer (B) is a copolymer containing 70 to 90% by mass of aromatic vinyl monomer units and 10 to 30% by mass of cyanide alkenyl monomer units. This configuration yields a multilayer material with excellent transparency and suppressed warping after humid heat treatment. In other words, in this embodiment, it is presumed that by carefully examining and combining copolymer (A) and copolymer (B), the two could be made compatible, resulting in a resin composition with excellent transparency. Furthermore, it is presumed that by balancing the ratio of (meth)acrylic monomer units to aromatic vinyl monomer units in the resin composition, warping after humid heat treatment was effectively suppressed.

[0010] <Copolymer (A)> The resin composition of this embodiment includes copolymer (A) comprising 36 to 96% by mass of (meth)acrylic monomer units, 0 to 60% by mass of aromatic vinyl monomer units, and a total of 3 to 64% by mass of cyclic acid anhydride units and / or N-substituted maleimide monomer units. By including copolymer (A), compatibility with copolymer (B) is improved compared to the case where polymethyl methacrylate (PMMA), a general-purpose acrylic resin, is used, and a resin composition with excellent transparency is obtained. In this embodiment, it is preferable that copolymer (A) is a copolymer comprising 36 to 96% by mass of (meth)acrylic monomer units, 1 to 60% by mass of aromatic vinyl monomer units, and a total of 3 to 64% by mass of cyclic acid anhydride units and / or N-substituted maleimide monomer units. More specifically, the proportion of (meth)acrylic monomer units in copolymer (A) is preferably 37% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, even more preferably 60% by mass or more, and even more preferably 65% ​​by mass or more. Setting it above the lower limit tends to improve scratch resistance. Furthermore, the proportion of (meth)acrylic monomer units in copolymer (A) is preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less, even more preferably 80% by mass or less, and even more preferably 75% by mass or less. Setting it below the upper limit tends to improve the refractive index of the resin composition and suppress the occurrence of interference fringes when laminated with polycarbonate. Furthermore, the proportion of aromatic vinyl monomer units in copolymer (A) is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, even more preferably 4% by mass or more, and may be 5% by mass or more. Setting it above the lower limit improves the refractive index of the resin composition, and effectively suppresses the generation of interference fringes when it is formed into a multilayer with a polycarbonate resin layer. Furthermore, the proportion of aromatic vinyl monomer units in copolymer (A) is preferably 55% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, even more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less. Setting it below the upper limit tends to improve scratch resistance and heat resistance. Furthermore, the proportion of cyclic acid anhydride units and / or N-substituted maleimide monomer units (preferably N-substituted maleimide monomer units) in copolymer (A) is preferably 4% by mass or more, more preferably 5% by mass or more, even more preferably 7% by mass or more, even more preferably 10% by mass or more, even more preferably 16% by mass or more, and even more preferably 20% by mass or more. Setting it above the lower limit tends to improve heat resistance. Also, the proportion of cyclic acid anhydride units and / or N-substituted maleimide monomer units (preferably N-substituted maleimide monomer units) in copolymer (A) is preferably 63% by mass or less, more preferably 55% by mass or less, even more preferably 45% by mass or less, even more preferably 40% by mass or less, even more preferably 35% by mass or less, even more preferably 30% by mass or less, and especially most preferably 25% by mass or less. Setting it below the upper limit tends to improve scratch resistance and toughness. Furthermore, the total proportion of (meth)acrylic monomer units, aromatic vinyl monomer units, and cyclic acid anhydride units and / or N-substituted maleimide monomer units in copolymer (A) is preferably 85% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 97% by mass or more, and even more preferably 99% by mass or more. Setting it above the lower limit tends to more effectively exhibit the effects of the present invention. The upper limit of the total proportion of (meth)acrylic monomer units, aromatic vinyl monomer units, and cyclic acid anhydride units and / or N-substituted maleimide monomer units in copolymer (A) is 100% by mass. In this embodiment, copolymer (A) may contain only one (meth)acrylic monomer unit, an aromatic vinyl monomer unit, a cyclic acid anhydride unit, and an N-substituted maleimide monomer unit, or it may contain two or more of each. When it contains two or more, it is preferable that the total amount is within the above range.

[0011] Copolymer (A) contains (meth)acrylic monomer units. The inclusion of (meth)acrylic monomer units tends to improve the pencil hardness of the resulting flat molded product. The (meth)acrylic compound is not particularly limited as long as it contains a (meth)acrylic group, but compounds represented by formula (a1) are preferred. Formula (a1) [ka] (In formula (a1), Ra 1 is a hydrogen atom or a methyl group, Ra 2 (This is an aliphatic group.) In the above equation (a1), Ra 1 Ra is a hydrogen atom or a methyl group, with a methyl group being preferred. 2 Ra is an aliphatic group, preferably a linear or branched aliphatic group, and more preferably a linear aliphatic group. Examples of aliphatic groups include alkyl groups (including cycloalkyl groups), alkynyl groups (including cycloalkynyl groups), alkenyl groups (including cycloalkenyl groups), etc., with alkyl groups being preferred, linear or branched alkyl groups being more preferred, and linear alkyl groups being even more preferred. 2 The number of carbon atoms in the aliphatic group is preferably 1 to 10, more preferably 1 to 5, even more preferably 1 to 3, even more preferably 1 or 2, and even more preferably 1. The (meth)acrylate represented by formula (a1) is preferably an alkyl (meth)acrylate (preferably an alkyl methacrylate), and more preferably a methyl (meth)acrylate (preferably methyl methacrylate). Using methyl methacrylate tends to improve the impact strength and pencil hardness of the resulting flat molded article.

[0012] Copolymer (A) may contain aromatic vinyl monomer units. The inclusion of aromatic vinyl monomer units can suppress the generation of interference fringes. The aromatic vinyl monomer in the copolymer (A) is a compound having a vinyl group and an aromatic ring group, and a compound copolymerizable with (meth)acrylate can be widely adopted. The aromatic vinyl monomer is CH2=CH-L 1 -Ar 1 and is preferably a compound represented by. Here, L 1 is a single bond or a divalent linking group, preferably a single bond or a divalent linking group with a formula weight of 100 to 500, more preferably a single bond or a divalent linking group with a formula weight of 100 to 300, and even more preferably a single bond. When L 1 is a divalent linking group, it is preferably a group composed of an aliphatic hydrocarbon group or a combination of an aliphatic hydrocarbon group and -O-. Here, the formula weight means the mass (g) per mole of the portion corresponding to L 1 in the aromatic vinyl monomer. Hereinafter, the same applies to other "formula weights". Ar 1 is an aromatic ring group, preferably a substituted or unsubstituted benzene ring group or naphthalene ring (preferably a benzene ring), and even more preferably an unsubstituted benzene ring group.

[0013] More specifically, the aromatic vinyl monomer preferably contains an aromatic vinyl monomer represented by formula (b1). Formula (b1)

Chemical formula

[0014] In formula (b1), Ra 3 is a substituent, and examples thereof include a halogen atom (preferably a chlorine atom, a fluorine atom or a bromine atom), a hydroxyl group, an alkyl group (preferably an alkyl group having 1 to 5 carbon atoms), an aryl group (preferably a phenyl group), an alkenyl group (preferably an alkenyl group having 2 to 5 carbon atoms), an alkoxy group (preferably an alkoxy group having 1 to 5 carbon atoms), and an aryloxy group (preferably a phenoxy group). When na is 2 or more, a plurality of Ra 3These may be the same or they may be different. na is preferably an integer less than or equal to 5, more preferably an integer less than or equal to 4, even more preferably an integer less than or equal to 3, even more preferably an integer less than or equal to 2, even more preferably an integer less than or equal to 1, and even more preferably 0.

[0015] The aromatic vinyl monomer is preferably a compound with a molecular weight of 104 to 600, more preferably a compound with a molecular weight of 104 to 400, and even more preferably 104 to 200. Aromatic vinyl monomers specifically include styrene monomers (styrene derivatives) such as styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene, vinylnaphthalene, methoxystyrene, monobromostyrene, dibromostyrene, fluorostyrene, and tribromostyrene, with styrene being particularly preferred.

[0016] Copolymer (A) contains cyclic acid anhydride monomer units and / or N-substituted maleimide monomer units. The inclusion of cyclic acid anhydride monomer units and / or N-substituted maleimide monomer units improves the heat resistance of the resulting plate-shaped molded article.

[0017] Examples of cyclic acid anhydride monomer units in copolymer (A) include maleic anhydride monomer units and glutaric acid anhydride monomer units, with maleic anhydride monomer units being preferred. Including cyclic acid anhydride monomer units, particularly maleic acid monomer units, more effectively improves compatibility with copolymer (B) and heat resistance. Examples of N-substituted maleimide monomer units in copolymer (A) include N-phenylmaleimide monomer units, N-cyclohexylmaleimide monomer units, N-benzylmaleimide monomer units, and N-(4-carboxyphenyl)maleimide monomer units, with N-phenylmaleimide monomer units and / or N-cyclohexylmaleimide monomer units being preferred. By including N-substituted maleimide monomer units, particularly N-phenylmaleimide monomer units and / or N-cyclohexylmaleimide monomer units, and even more so by including both N-phenylmaleimide monomer units and N-cyclohexylmaleimide monomer units, heat resistance and compatibility with copolymer (B) are more effectively exhibited.

[0018] The copolymer (A) in this embodiment may or may not contain other monomer units other than (meth)acrylic monomer units, aromatic vinyl monomer units, cyclic acid anhydride units, and N-substituted maleimide monomer units. Other examples of monomeric units include aliphatic vinyl compound units, lactone ring structural units, and glutarimide units.

[0019] The initial glass transition temperature (Tig) of the copolymer (A) is preferably 120°C or higher, more preferably 125°C or higher, even more preferably 127°C or higher, and even more preferably 130°C or higher. Setting it above the lower limit tends to further improve the crack prevention effect during hot bending molding. Furthermore, the initial glass transition temperature (Tig) of the copolymer (A) is preferably 170°C or lower, more preferably 160°C or lower, even more preferably 150°C or lower, and may also be 140°C or lower. Setting it below the upper limit tends to further improve the springback suppression effect during hot bending molding. If the resin composition of this embodiment contains two or more copolymers (A), the starting glass transition temperature (Tig) of copolymer (A) shall be the Tig of the mixture. Furthermore, the method for measuring the glass transition temperature shall be as described in the examples below (the same applies to the weight-average molecular weight, pencil hardness, and the glass transition temperature, weight-average molecular weight, and pencil hardness of copolymer (B) hereafter).

[0020] The weight-average molecular weight of the copolymer (A) is preferably 50,000 or more, more preferably 70,000 or more, even more preferably 100,000 or more, and may be 150,000 or more. Setting it above the lower limit can further improve the impact strength of the resulting flat molded article. The weight-average molecular weight of the copolymer (A) is preferably 300,000 or less, more preferably 250,000 or less, even more preferably 225,000 or less, even more preferably 210,000 or less, and even more preferably 200,000 or less. Setting it below the upper limit can effectively lower the melt viscosity of the resin composition.

[0021] The pencil hardness of the copolymer (A) is preferably HB or higher, more preferably F or higher, and even more preferably H or higher. By setting it to be above the lower limit, the surface hardness of the resulting flat molded article can be increased. Furthermore, the pencil hardness of the copolymer (A) is preferably 2H or lower, and more preferably H or lower.

[0022] The refractive index of the copolymer (A) is preferably 1.51 or higher, and more preferably 1.52 or higher. The upper limit is, for example, 1.57 or lower, and may also be 1.55 or lower, or 1.54 or lower.

[0023] <Copolymer (B)> The resin composition of this embodiment comprises a copolymer (B) containing 70 to 90% by mass of aromatic vinyl monomer units and 10 to 30% by mass of alkenyl cyanide monomer units. The proportion of aromatic vinyl monomer units in copolymer (B) is preferably 71% by mass or more, more preferably 72% by mass or more, even more preferably 73% by mass or more, even more preferably 74% by mass or more, and even more preferably 75% by mass or more. Furthermore, the proportion of aromatic vinyl monomer units in copolymer (B) is preferably 87% by mass or less, more preferably 85% by mass or less, even more preferably 83% by mass or less, even more preferably 80% by mass or less, and even more preferably 78% by mass or less. By setting the proportions above the lower limit and below the upper limit, a resin composition that is compatible with copolymer A and has excellent transparency tends to be obtained. The proportion of alkenyl cyanide monomer units in copolymer (B) is preferably 13% by mass or more, more preferably 15% by mass or more, even more preferably 17% by mass or more, even more preferably 20% by mass or more, and even more preferably 22% by mass or more. Setting it above the lower limit tends to improve heat resistance. Furthermore, the proportion of alkenyl cyanide monomer units in copolymer (B) is preferably 29% by mass or less, more preferably 28% by mass or less, even more preferably 27% by mass or less, even more preferably 26% by mass or less, and even more preferably 25% by mass or less. Setting it below the upper limit tends to yield a resin composition that is compatible with copolymer A and has excellent transparency.

[0024] Furthermore, the total proportion of aromatic vinyl monomer units and alkenyl cyanide monomer units in copolymer (B) is preferably 85% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 95% by mass or more, and even more preferably 99% by mass or more. Setting it above the lower limit tends to more effectively exhibit the effects of the present invention. The upper limit of the total proportion of aromatic vinyl monomer units and alkenyl cyanide monomer units in copolymer (B) is 100% by mass. In this embodiment, copolymer (B) may contain only one aromatic vinyl monomer unit and one alkenyl cyanide monomer unit, or two or more units. When two or more units are included, it is preferable that the total amount is within the above range.

[0025] Copolymer (B) contains aromatic vinyl monomer units. The inclusion of aromatic vinyl monomer units results in a flat molded article with excellent flow marks. The aromatic vinyl monomers constituting the aromatic vinyl monomer units in copolymer (B) are the same as the aromatic vinyl monomers constituting the aromatic vinyl monomer units in copolymer (A), and the preferred range is also the same.

[0026] Copolymer (B) contains alkenyl cyanide monomer units. The inclusion of alkenyl cyanide monomer units results in a flat molded article with excellent transparency. The cyanide alkenyl monomer constituting the cyanide alkenyl monomer unit in copolymer (B) is preferably acrylonitrile and methacrylonitrile, with acrylonitrile being more preferred.

[0027] The copolymer (B) in this embodiment may or may not contain other monomer units other than aromatic vinyl monomer units and alkenyl cyanide monomer units. Other monomer units include (meth)acrylic monomer units, cyclic acid anhydride monomer units, and N-substituted maleimide monomer units.

[0028] The initial glass transition temperature (Tig) of the copolymer (B) is preferably 95°C or higher, more preferably 100°C or higher, even more preferably 102°C or higher, and even more preferably 104°C or higher. Setting it above the lower limit tends to suppress cracking during hot bending molding. Furthermore, the initial glass transition temperature (Tig) of the copolymer (B) is preferably 130°C or lower, more preferably 120°C or lower, even more preferably 115°C or lower, and may also be 110°C or lower, or 107°C or lower. Setting it below the upper limit tends to further improve the effect of suppressing springback during hot bending molding.

[0029] The weight-average molecular weight of copolymer (B) is preferably 50,000 or more, more preferably 60,000 or more, even more preferably 80,000 or more, even more preferably 90,000 or more, and even more preferably 100,000 or more. Setting it above the lower limit can further improve the impact strength of the resulting flat molded article. Furthermore, the weight-average molecular weight of copolymer (B) is preferably 200,000 or less, more preferably 180,000 or less, even more preferably 170,000 or less, even more preferably 160,000 or less, even more preferably 150,000 or less, and may also be 130,000 or less. Setting it below the upper limit can effectively lower the melt viscosity of the resin composition.

[0030] The pencil hardness of the copolymer (B) is preferably B or higher, and more preferably HB or higher. By setting it to be above the lower limit, the surface hardness of the resulting flat molded article can be increased. Furthermore, the pencil hardness of the copolymer (B) is preferably H or lower, and more preferably HB or lower.

[0031] The refractive index of the copolymer (B) is preferably 1.54 or higher, more preferably 1.55 or higher, even more preferably 1.56 or higher, even more preferably 1.57 or higher, and may be 1.58 or higher. The upper limit is, for example, 1.60 or lower, and may be 1.59 or lower.

[0032] <Blending ratio of copolymer (A) and copolymer (B)> The resin composition of this embodiment contains 30 to 90 parts by mass of copolymer (A) and 70 to 10 parts by mass of copolymer (B). In this embodiment, it is particularly preferable that the ratio of copolymer (A) is 35 parts by mass or more, more preferably 40 parts by mass or more, even more preferably 45 parts by mass or more, and may be 51 parts by mass or more, 56 parts by mass or more, or 60 parts by mass or more, based on a total of 100 parts by mass of copolymer (A) and copolymer (B). Setting it above the lower limit tends to improve scratch resistance and further improve the crack suppression effect during heat bending molding. Furthermore, it is preferable that the ratio of copolymer (A) is 85 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 76 parts by mass or less, and may be 74 parts by mass or less, or 70 parts by mass or less, based on a total of 100 parts by mass of copolymer (A) and copolymer (B). Setting it below the upper limit makes it easier to produce flat molded articles with excellent flow marks, and interference fringes tend to be less likely to occur when a multilayer body with a polycarbonate resin layer is formed. The resin composition of this embodiment may contain only one copolymer (A) and one copolymer (B), or two or more copolymers. When two or more copolymers are included, it is preferable that the total amount is within the above range.

[0033] In this embodiment, the resin composition preferably contains 85% by mass or more of copolymer (A) and copolymer (B) in total, more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 97% by mass or more, and even more preferably 99% by mass or more. By setting the content above the lower limit, the effects of the present invention tend to be exhibited more effectively. The upper limit of the total content of copolymer (A) and copolymer (B) in the resin composition is 100% by mass.

[0034] In the resin composition of this embodiment, the ratio of (meth)acrylic monomer units to the total mass of copolymer (A) and copolymer (B) is preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, and even more preferably 40% by mass or more. Setting it above the lower limit tends to further improve scratch resistance. Furthermore, the ratio of (meth)acrylic monomer units to the total mass of copolymer (A) and copolymer (B) is preferably 70% by mass or less, more preferably 65% ​​by mass or less, even more preferably 63% by mass or less, and even more preferably 50% by mass or less. Setting it below the upper limit tends to further improve heat resistance. In the resin composition of this embodiment, the ratio of aromatic vinyl monomer units (preferably styrene monomer units) to the total mass of copolymer (A) and copolymer (B) is preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more. Setting it above the lower limit improves the refractive index and tends to suppress the occurrence of interference fringes when laminated with polycarbonate. Furthermore, the ratio of aromatic vinyl monomer units (preferably styrene monomer units) to the total mass of copolymer (A) and copolymer (B) is preferably 45% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less, even more preferably 33% by mass or less, and even more preferably 30% by mass or less. Setting it below the upper limit tends to suppress warping after the wet heat test.

[0035] <Antioxidant> The resin composition of this embodiment preferably contains an antioxidant. Examples of antioxidants include phenolic antioxidants, amine antioxidants, phosphorus-based antioxidants, and thioether-based antioxidants. In this embodiment, phosphorus-based antioxidants and phenolic antioxidants (more preferably hindered phenolic antioxidants) are preferred. Phosphorus-based antioxidants are particularly preferred because they provide excellent coloration for resin compositions and flat molded articles.

[0036] Phosphorus-based antioxidants are preferred, and phosphite compounds represented by the following formulas (1) or (2) are preferred. [ka] (In formula (1), R 11 and R 12 Each of these independently represents an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms. [ka] (In formula (2), R 13 ~R 17 Each of these independently represents a hydrogen atom, an aryl group with 6 to 20 carbon atoms, or an alkyl group with 1 to 20 carbon atoms.

[0037] In the above equation (1), R 11 , R 12 The alkyl groups represented are preferably linear or branched alkyl groups having 1 to 10 carbon atoms, independently of each other. 11 , R 12 If the group is an aryl group, an aryl group represented by any of the following formulas (1-a), (1-b), or (1-c) is preferred. The asterisk (*) in the formula represents the bond position.

[0038] [ka] (In formula (1-a), RA Each of these independently represents an alkyl group having 1 to 10 carbon atoms. In formula (1-b), R B Each of these independently represents an alkyl group having 1 to 10 carbon atoms.

[0039] For hindered phenol antioxidants, refer to paragraph 0063 of Japanese Patent Publication No. 2018-090677 and paragraph 0076 of Japanese Patent Publication No. 2018-188496, which are incorporated herein by reference.

[0040] In addition to the above, the antioxidants can be described in paragraphs 0057 to 0061 of Japanese Patent Publication No. 2017-031313, and this content is incorporated herein by reference.

[0041] The antioxidant content is preferably 0.001 parts by mass or more, and more preferably 0.008 parts by mass or more, per 100 parts by mass of the resin composition. Furthermore, the upper limit of the antioxidant content is preferably 0.5 parts by mass or less, more preferably 0.3 parts by mass or less, even more preferably 0.2 parts by mass or less, even more preferably 0.15 parts by mass or less, even more preferably 0.10 parts by mass or less, and especially most preferably 0.08 parts by mass or less, per 100 parts by mass of the resin composition.

[0042] By setting the antioxidant content above the lower limit, a flat molded article with better hue and heat discoloration resistance can be obtained. Furthermore, by setting the antioxidant content below the upper limit, a flat molded article with good moist heat stability can be obtained without worsening heat discoloration resistance. The antioxidant may be used alone or in combination of two or more types. If two or more types are used, it is preferable that the total amount be within the above range.

[0043] <Release agent> The resin composition of this embodiment preferably contains a mold release agent. By including a mold release agent, the moldability of the flat molded product can be improved. There are no specific requirements regarding the type of release agent, but examples include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds with a number average molecular weight of 200 to 15,000, polyethers with a number average molecular weight of 100 to 5,000, and polysiloxane-based silicone oils.

[0044] Details of the release agent can be found in paragraphs 0035-0039 of International Publication No. 2015 / 190162, which are incorporated herein by reference.

[0045] The release agent content is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, and even more preferably 0.01 parts by mass or more, per 100 parts by mass of the resin composition. The upper limit is preferably 0.5 parts by mass or less, more preferably 0.3 parts by mass or less, and even more preferably 0.2 parts by mass or less. The release agent may be used by one type only, or by two or more types. When using two or more types, it is preferable that the total amount be within the above range.

[0046] In particular, the resin composition of this embodiment preferably contains a total of 0.001 to 0.5 parts by mass of antioxidants and / or release agents per 100 parts by mass of the resin composition.

[0047] <Other ingredients> The resin composition of this embodiment may also contain, in addition to the above components, other thermoplastic resins, ultraviolet absorbers, heat stabilizers, flame retardants, flame retardant enhancers, colorants, antistatic agents, fluorescent whitening agents, antifogging agents, flow modifiers, plasticizers, dispersants, antibacterial agents, antiblocking agents, impact modifiers, sliding modifiers, hue modifiers, acid trapping agents, etc. These components may be used individually or in combination of two or more. The content of the above components, if present, is preferably 0.1 to 5% by mass of the resin composition in total.

[0048] <Physical properties of resin compositions> The resin composition of this embodiment preferably has excellent transparency. Specifically, when the resin composition of this embodiment is molded to a thickness of 1 mm, the haze is preferably 5.0% or less, more preferably 2.0% or less, even more preferably 1.0% or less, even more preferably 0.4% or less, even more preferably 0.3% or less, even more preferably less than 0.2%, and may be 0.15% or less. The lower limit is ideally 0%, but 0.01% or more is practical. The haze is measured according to the examples described below.

[0049] The resin composition of this embodiment tends to have a higher refractive index. Specifically, the refractive index of the resin composition of this embodiment is preferably 1.54 or higher, and more preferably 1.55 or higher. The upper limit is, for example, 1.58 or lower, but may also be 1.57 or lower, or 1.56 or lower. Such refractive indices can be achieved by adjusting the types of monomer units, monomer ratios, and blend ratios of copolymers (A) and (B). The refractive index is measured according to the method described in the examples described later.

[0050] The resin composition of this embodiment preferably has a high Tig (TiG) onset temperature determined by differential scanning calorimetry. Specifically, the Tig onset temperature of the resin composition of this embodiment is preferably 115°C or higher, more preferably 118°C or higher, even more preferably 119°C or higher, even more preferably 120°C or higher, and even more preferably 121°C or higher. By setting it above the lower limit, the occurrence of cracks can be effectively suppressed. Furthermore, the durability in environmental resistance tests such as humid heat tests and high-temperature tests tends to be further improved. The upper limit of the Tig onset temperature determined by differential scanning calorimetry is, for example, 130°C or lower, and even 125°C or lower is sufficient to meet the required performance. The starting glass transition temperature (Tig) is measured according to the method described in the examples below. To increase the initial glass transition temperature (TIG), one example is to adjust the raw material monomers of the resin. Another method is to increase the molecular weight of the resin. The initial glass transition temperature of a resin is generally determined by the raw material monomers and molecular weight, and can be appropriately selected by those skilled in the art.

[0051] The resin composition of this embodiment preferably has a high pencil hardness (hardness). Specifically, when the resin composition of this embodiment is molded to a thickness of 1 mm and measured with a pencil hardness tester in accordance with JIS K5600-5-4:1999 under a 750 g load, the pencil hardness is preferably F or higher, and more preferably H or higher. By setting the pencil hardness to F or higher, the overall hardness of the multilayer can be increased, and scratch resistance can be improved. There is no particular upper limit, but 3H or lower is practical. The pencil hardness is measured according to the example described below.

[0052] The resin composition of this embodiment preferably has a melt mass flow rate (MFR) of 1.0 g / 10 min or more at 230°C and a load of 3.8 kg. Setting it above the lower limit tends to further improve moldability, effectively suppress deterioration and yellowing of the resin composition, and effectively suppress the decomposition of resin components. The MFR is preferably 1.2 g / 10 min or more, more preferably 1.3 g / 10 min or more, even more preferably 1.4 g / 10 min or more, and even more preferably 1.5 g / 10 min or more. Furthermore, the upper limit of the MFR is preferably 11.0 g / 10 min or less, more preferably 10.0 g / 10 min or less, even more preferably 8.0 g / 10 min or less, even more preferably 6.0 g / 10 min or less, and even more preferably 4.0 g / 10 min or less. Setting it below the upper limit tends to improve moldability and suppress the occurrence of flow marks. Such MFRs can be achieved by appropriately adjusting the weight-average molecular weight and / or number-average molecular weight of copolymer resin A and / or copolymer B. The MFR is measured according to the method described in the examples below.

[0053] <Flat-shaped molded body> The resin composition of this embodiment is preferably used in the form of a flat molded body. That is, the flat molded body of this embodiment is formed from the resin composition of this embodiment. The flat molded body of this embodiment has excellent transparency and effectively suppresses warping after a humid heat test. Examples of flat molded bodies include plates, films, and sheets. Furthermore, as will be described in detail later, the flat molded body may be included in a multilayer structure laminated on other substrates. Also, the flat molded body of this embodiment may be subjected to bending or other processes after being incorporated into a part of the multilayer structure. The thickness of the flat molded body has a lower limit, for example, 1 μm or more, preferably 10 μm or more, more preferably 20 μm or more, even more preferably 50 μm or more, even more preferably 80 μm or more, and may be 90 μm or more. Setting the thickness above the lower limit makes molding easier and tends to improve hardness. There is no particular upper limit to the thickness of the flat molded body, but it is preferably 5,000 μm or less, more preferably 2,000 μm or less, even more preferably 1,000 μm or less, even more preferably 500 μm or less, and even more preferably 300 μm or less. In particular, as will be described in detail later, it is preferable that the flat molded body is thinner than the sum of the thicknesses of the flat molded body and the polycarbonate resin layer. With such a configuration, even when the multilayer body is heat-molded, the occurrence of cracks is effectively suppressed and the occurrence of springback is effectively suppressed. The flat molded body of this embodiment is formed by injection molding, extrusion molding using a T-die, or the like.

[0054] <Multilayer body> The multilayer body of this embodiment comprises the plate-shaped molded body of this embodiment and at least one other layer. Such a multilayer body has excellent surface hardness. In this embodiment, it is preferable that the other at least one layer is a layer containing polycarbonate resin (polycarbonate resin layer). The polycarbonate resin layer usually serves as the base material of the multilayer body. The multilayer body of this embodiment preferably further includes a hard coat layer. The hard coat layer is preferably provided on the surface of the flat molded body of this embodiment. Furthermore, it is more preferable that the hard coat layer is laminated in the order of the polycarbonate resin layer, the flat molded body, and the hard coat layer. The hard coat layer may also be provided on the polycarbonate resin layer side. Other layers may be present between the polycarbonate resin layer and the flat molded body, and between the flat molded body and the hard coat layer, without departing from the spirit of this embodiment. Figure 1 is a schematic diagram showing an example of a multilayer body according to this embodiment, where 1 represents the multilayer body, 2 represents the substrate (polycarbonate resin layer), 3 represents the flat molded body, and 4 represents the hard coat layer. In this embodiment, other layers may be present without departing from the spirit of this embodiment. Specific examples of other layers include adhesive layers, tack layers, and antifouling layers. Furthermore, it is preferable that the multilayer of this embodiment has a low refractive index layer on the hard coat layer, on the side opposite to the substrate (the polycarbonate resin layer). That is, the multilayer can be used as an anti-reflective film. In this embodiment, it is preferable that one or more of the following treatments are applied to one or both sides of the multilayer: fingerprint-resistant, anti-reflective, anti-glare, weather-resistant, anti-static, anti-fouling, and anti-blocking. An example of the outermost surface of the multilayer in this case is a hard coat layer. Anti-blocking treatment refers to a treatment that allows films to be easily separated even if they are in close contact with each other, and examples include adding an anti-blocking agent or creating irregularities on the surface of the multilayer.

[0055] Next, we will describe the base material 1. The type of base material 1 is not particularly specified, and any known base material can be used as long as it satisfies the performance required for the multilayer body of this embodiment. Specifically, a resin base material is preferred, polyolefin resin, polyester resin, polycarbonate resin, acrylic resin, and polystyrene resin are more preferred, and it is even more preferable that it contains polycarbonate resin. These resins may be used individually or to form a composite base material of two or more types. In the multilayer body of this embodiment, as described above, the base material 1 is preferably a layer containing polycarbonate resin (polycarbonate resin layer). The proportion of polycarbonate resin in the polycarbonate resin layer is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0056] The polycarbonate resin used in this embodiment preferably has an end structure represented by formula (1). By using a polycarbonate resin having an end structure represented by formula (1), the glass transition temperature of the polycarbonate resin can be lowered. [ka] (In formula (1), R 1 R represents an alkyl group having 8 to 36 carbon atoms, or an alkenyl group having 8 to 30 carbon atoms. 2 Each of these independently represents a halogen atom, an alkyl group with 1 to 20 carbon atoms, or an aryl group with 6 to 12 carbon atoms. n represents an integer from 0 to 4. * indicates a bonding site with another part.

[0057] R 1 This represents an alkyl group having 8 to 36 carbon atoms, or an alkenyl group having 8 to 30 carbon atoms, preferably an alkyl group or alkenyl group having 10 or more carbon atoms, more preferably an alkyl group or alkenyl group having 12 or more carbon atoms, and even more preferably an alkyl group or alkenyl group having 14 or more carbon atoms. This lowers the glass transition temperature of the resin and further improves the thermal flexibility of the multilayer. Also, R 1It is preferably an alkyl group or alkenyl group having 22 or fewer carbon atoms, and more preferably an alkyl group or alkenyl group having 18 or fewer carbon atoms. This further improves compatibility with other resins. 1 It is preferable that the alkyl group is an alkyl group. The alkyl group and alkenyl group are preferably linear or branched alkyl or alkenyl groups, and more preferably linear alkyl or alkenyl groups. In this embodiment, R 1 It is particularly preferable that this is a hexadecyl group. Also, R 1 It may be located at the meta, para, or ortho position, but it is preferably located at the meta or para position, and more preferably at the para position.

[0058] R 2 Each of these independently represents a halogen atom, a C1-C20 alkyl group, or a C6-C12 aryl group, preferably a fluorine atom, a chlorine atom, a methyl group, an ethyl group, or a phenyl group, and more preferably a fluorine atom, a chlorine atom, or a methyl group. n represents an integer between 0 and 4, preferably between 0 and 2, more preferably 0 or 1, and even more preferably 0.

[0059] The terminal structure represented by formula (1) can be added to a polycarbonate resin by using an end-capturing agent such as hexadecyl parahydroxybenzoate. Details thereof can be found in paragraphs 0022 to 0030 of Japanese Patent Application Publication No. 2019-002023, and these contents are incorporated herein by reference. The aromatic polycarbonate resin used in this embodiment may have one or more terminal structures represented by formula (1).

[0060] In this embodiment, the aromatic polycarbonate resin having the terminal structure represented by formula (1) is preferably a bisphenol-type polycarbonate resin, and more preferably a bisphenol A-type polycarbonate resin. Furthermore, it is preferable that 50 mol% or more of the bisphenol-type polycarbonate resin has at least one terminal structure represented by formula (1).

[0061] Bisphenol A type polycarbonate resin may also have other structural units other than carbonate structural units derived from bisphenol A and its derivatives. Examples of dihydroxy compounds constituting such other structural units include aromatic dihydroxy compounds described in paragraph 0014 of Japanese Patent Application Publication No. 2018-154819, the details of which are incorporated herein by reference. In this embodiment, the bisphenol-type polycarbonate resin preferably contains carbonate structural units derived from bisphenol A and its derivatives accounting for 90% or more by mass of all structural units excluding terminal structures, more preferably 95% or more by mass, and even more preferably 97% or more by mass.

[0062] The method for producing bisphenol A type polycarbonate resin is not particularly limited, and any method can be used. Examples include interfacial polymerization, molten transesterification, pyridine method, ring-opening polymerization of cyclic carbonate compounds, and solid-phase transesterification of prepolymers.

[0063] The weight-average molecular weight of the polycarbonate resin is not particularly defined, but is preferably 10,000 or more, more preferably 20,000 or more, even more preferably 30,000 or more, even more preferably 40,000 or more, and even more preferably 50,000 or more. Setting it above the lower limit tends to further improve the impact resistance of the multilayer and suppression of flow marks during molding. Furthermore, the weight-average molecular weight of the polycarbonate resin is preferably 200,000 or less, more preferably 150,000 or less, even more preferably 100,000 or less, even more preferably 80,000 or less, and even more preferably 60,000 or less. Setting it below the upper limit tends to improve the moldability of the multilayer.

[0064] The starting glass transition temperature (Tig) of the polycarbonate resin having the end structure represented by formula (1) used in this embodiment is preferably 130°C or lower, and more preferably 125°C or lower. Setting it below the upper limit tends to further improve the heat-bending moldability of the multilayer. Furthermore, the starting glass transition temperature (Tig) of the polycarbonate resin having the end structure represented by formula (1) used in this embodiment is preferably 121°C or higher, more preferably 122°C or higher, and even more preferably 123°C or higher. Setting it above the lower limit tends to further improve the durability of the resulting multilayer in environmental resistance tests such as humid heat tests and high-temperature tests. The refractive index of the polycarbonate resin used in this embodiment is, for example, 1.55 or higher, may be 1.56 or higher, or 1.57 or higher. The upper limit is, for example, 1.61 or lower, may be 1.60 or lower, or 1.59 or lower.

[0065] Further details regarding polycarbonate resin can be found in paragraphs 0040-0073 of Japanese Patent Publication No. 2019-035001 and paragraphs 0016-0043 of Japanese Patent Publication No. 2018-103518, the contents of which are incorporated herein by reference.

[0066] The base material 1 may contain various resin additives as needed, provided that the desired physical properties are not significantly impaired. Examples of resin additives include antioxidants, mold release agents, flame retardants, anti-dripping agents, dyes and pigments (including carbon black), antistatic agents, anti-fogging agents, anti-blocking agents, flow improvers, plasticizers, dispersants, and antibacterial agents. The base material may contain only one type of resin additive, or two or more types in any combination and ratio.

[0067] Furthermore, the base material 1 may be a single layer or a multi-layer material. The thickness of the base material 1 (preferably a polycarbonate resin layer) is not particularly limited, but for example, it is 1 μm or more, preferably 30 μm or more, more preferably 35 μm or more, even more preferably 40 μm or more, even more preferably 50 μm or more, even more preferably 100 μm or more, even more preferably 300 μm or more, especially more preferably 500 μm or more, and may also be 700 μm or more. Furthermore, the thickness of the base material 1 is preferably 10,000 μm or less, more preferably 5,000 μm or less, may also be 3,000 μm or less, and may also be 2,500 μm or less.

[0068] As described above, the multilayer body of this embodiment preferably includes a flat molded body and a base material. In this case, it is preferable that the relationship between the thickness of the flat molded body and the base material (preferably a polycarbonate resin layer) satisfies the condition: thickness of the flat molded body / [total thickness of the flat molded body and base material] < 1 / 5. By satisfying this relationship, the flat molded body becomes thinner as a whole in the multilayer body, so that even when the multilayer body is heat-molded, the occurrence of cracks is more effectively suppressed, and the occurrence of springback is also more effectively suppressed. More specifically, in order to suppress springback, it is more effective to relieve the residual stress due to bending that remains in the entire multilayer body when the multilayer body is bent. From this viewpoint, it is more preferable to relieve the residual stress not only in the base material but also in the flat molded body. By ensuring that the flat molded body and the base material satisfy the above relationship, the residual stress originating from the flat molded body is more easily relieved, and springback can be suppressed more effectively. In this embodiment, it is more preferable that the thickness of the flat molded body / [total thickness of the flat molded body and base material] < 1 / 6, and even more preferable that the thickness of the flat molded body / [total thickness of the flat molded body and base material] < 1 / 8. Furthermore, it is preferable that 1 / 35 < thickness of the flat molded body / [total thickness of the flat molded body and base material], and even more preferable that 1 / 25 < thickness of the flat molded body / [total thickness of the flat molded body and base material]. In particular, in this embodiment, it is more preferable that the flat molded body and base material satisfy the above-mentioned preferred range of thickness, and that the multilayer body satisfies the preferred range of thickness described later, while satisfying the above relationship. By adopting such a configuration, the effects of the present invention are achieved more effectively.

[0069] In this embodiment, the change in warpage of the multilayer body consisting of the flat molded body (acrylic resin layer) and the polycarbonate resin layer after being left standing for 120 hours in an environment of 85°C and 85% relative humidity is preferably less than 600 μm, more preferably less than 350 μm, and even more preferably less than 200 μm. The lower limit of the change in warpage is ideally 0 μm, but 1 μm or more is practical. The amount of warpage change is measured according to the description in the examples below.

[0070] Next, the details of the hard coat layer will be described. The hard coat layer that may be included in the multilayer of this embodiment is a layer with a higher surface hardness than the substrate (for example, the polycarbonate resin layer). By including such a hard coat layer, the surface hardness of the multilayer or molded product can be increased. The thickness of the hard coat layer is preferably 0.5 μm or more, more preferably 1 μm or more, even more preferably 2 μm or more, even more preferably 4 μm or more, and even more preferably 5 μm or more. Setting it above the lower limit tends to further improve the pencil hardness of the entire multilayer structure due to the hard coat layer. The upper limit of the hard coat layer thickness is preferably 20 μm or less, more preferably 15 μm or less, even more preferably 12 μm or less, even more preferably 10 μm or less, and even more preferably 8 μm or less. Setting it below the upper limit tends to further improve the processability when heat bending.

[0071] The hard coat layer is preferably obtained by applying a hard coat material that can be cured by heat or by active energy rays, and then curing it. Examples of coatings cured using active energy rays include resin compositions consisting of one or more monofunctional or polyfunctional (preferably 2 to 10-functional) (meth)acrylate monomers or oligomers, and preferably resin compositions containing monofunctional or polyfunctional (preferably 2 to 10-functional) urethane (meth)acrylate oligomers. It is preferable that a photopolymerization initiator be added to these resin compositions as a curing catalyst. Examples of thermosetting resin coatings include polyorganosiloxane-based and cross-linked acrylic-based coatings. Some of these resin compositions are commercially available as hard coat agents for acrylic resin or polycarbonate resin films or sheets, and should be selected appropriately considering their suitability for the painting line. For the hard coat layer, reference can be given to paragraphs 0045 to 0055 of Japanese Patent Publication No. 2013-020130, paragraphs 0073 to 0076 of Japanese Patent Publication No. 2018-103518, and paragraphs 0062 to 0082 of Japanese Patent Publication No. 2017-213771, and these contents are incorporated herein by reference.

[0072] The total thickness of the multilayer in this embodiment is not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 100 μm or more. A thicker layer thickness tends to improve the rigidity of the multilayer. Furthermore, the total thickness of the multilayer is preferably 10,000 μm or less, more preferably 5,000 μm or less, and may be 2,000 μm or less. By using such layer thicknesses, when the multilayer sheets are pressed together between rolls during multilayer molding and the resin is cooled, the resin is cooled all the way to the inside of the multilayer, thereby improving the moldability of the multilayer.

[0073] The multilayer body of this embodiment can be formed by using a main extruder that extrudes a resin composition containing polycarbonate resin and a sub-extruder that extrudes the resin composition of this embodiment, melting the resin under the conditions of the resin used in each, guiding it to an extrusion die, and laminating it inside the die to form a sheet, or laminating it after it has been formed into a sheet.

[0074] The multilayer body of this embodiment also has excellent heat bending resistance, making it suitable for applications involving bent sections. For example, it is preferably used in molded products having sections with a radius of curvature of 50 mmR or less (preferably 40 to 50 mmR). The molded article is preferably obtained by thermo-bending the multilayer body of this embodiment at 130 to 150°C (preferably 133 to 143°C). The multilayer body of this embodiment has excellent thermo-bending resistance, which is particularly beneficial when the molded article has a portion with a radius of curvature of 50 mmR or less. Furthermore, it is preferable that the temperature be 133°C or higher from the viewpoint of preventing springback and cracking. Setting the temperature above the lower limit allows for a shorter thermo-bending time, accelerates stress relaxation of the resin, and makes springback less likely to occur, which is preferable. In addition, the thermo-bending temperature is preferably 147°C or lower, more preferably 144°C or lower, and even more preferably 143°C or lower.

[0075] <Application> The resin composition, flat molded body, and multilayer body of this embodiment can be suitably used in molded articles, such as optical components, decorative products, and anti-reflective molded articles. That is, the molded article of this embodiment includes the flat molded body or multilayer body of this embodiment. The flat molded articles and multilayer articles of this embodiment are suitably used in components for display devices, electrical and electronic equipment, office automation equipment, portable information terminals, machine parts, home appliances, vehicle parts, various containers, lighting equipment, and the like. Among these, they are particularly suitable for use in housings for various displays, electrical and electronic equipment, office automation equipment, portable information terminals, and home appliances, lighting equipment and vehicle parts (especially vehicle interior parts), surface films for smartphones and touch panels, optical materials, and optical discs. In particular, the molded articles of this embodiment are suitably used as sensor films for touch panels and anti-reflective molded articles for various displays. [Examples]

[0076] The present invention will be described in more detail below with reference to examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate, as long as they do not depart from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or other reasons, measurements can be taken using other instruments with equivalent performance.

[0077] 1.Raw materials ·Copolymer (A) (A1) Asahi Kasei Chemicals Corporation, acrylic resin, Delpet PM120N, styrene:N-phenylmaleimide:methyl methacrylate (MMA) mass ratio = 4%:15%:81%, Tig: 126℃, Mw: 121,000, pencil hardness 2H, refractive index: 1.53 (A2) Nippon Shokubai Co., Ltd., acrylic resin, PML203, styrene:N-phenylmaleimide:N-cyclohexylmaleimide:MMA mass ratio = 6 mass%:19 mass%:4 mass%:71 mass%, Tig: 135℃, Mw: 189,000, pencil hardness 2H, refractive index: 1.53

[0078] ·Copolymer (B) (B1) Daicel Mirise Co., Ltd., styrene resin, 020SF, styrene:acrylonitrile mass ratio = 74%:26%, Tig: 106℃, Mw: 145,500, pencil hardness HB, refractive index: 1.58 (B2) Daicel Mirise Co., Ltd., styrene resin, 050SF, styrene:acrylonitrile mass ratio = 76%:24%, Tig: 105℃, Mw: 126,800, pencil hardness HB, refractive index: 1.58 (B3) Daicel Mirise Co., Ltd., styrene resin, 090SF, styrene:acrylonitrile mass ratio = 68%:32%, Tig: 108℃, Mw: 103,800, pencil hardness HB, refractive index: 1.57

[0079] • PMMA(C) (C) Manufactured by Arkema, Polymethyl Methacrylate, ALTUGLAS® V020

[0080] • Polystyrene (D) (D) Manufactured by PS Japan, SPG10

[0081] • Antioxidant (E) (E) Adekastab PEP-36, the following compound, where tBu represents a t-butyl group. [ka]

[0082] • Release agent (F) (F) Glycerin monostearate, manufactured by Riken Vitamin Co., Ltd., Rikemar S-100A

[0083] • Polycarbonate resin T-1380: Bisphenol A type polycarbonate resin using hexadecyl parahydroxybenzoate as an end-cap encapsulant, manufactured by Mitsubishi Gas Chemical Company, Inc., Tig: 124℃, refractive index: 1.58, Mw 55,000

[0084] 2. Examples 1-4, Comparative Examples 1-12 <Manufacturing of resin compositions (pellets)> Each of the components listed above was weighed to the amounts shown in Tables 1-3 (the amounts for each component in Tables 1-3 are expressed in parts by mass). After mixing in a tumbler for 15 minutes, the mixture was melt-kneaded at a cylinder temperature of 260°C using a twin-screw extruder with a screw diameter of 32 mm and a vent (TEX30α, manufactured by Japan Steel Works, Ltd.), and pellets were obtained by strand cutting.

[0085] <Pellet appearance> The obtained pellets were visually evaluated for their appearance. The evaluation was conducted by five experts, and the decision was made by majority vote. A: It was transparent. B: Anything other than A above (for example, no pellets were obtained, or the obtained pellets were semi-transparent or cloudy). Furthermore, the pellets that received an evaluation of "A" (resin compositions of Examples 1-4 or Comparative Examples 1-6) were further evaluated as follows.

[0086] <Measurement of the initial glass transition temperature (TIG)> The initial glass transition temperature (TIG) of polycarbonate resin and resin composition was determined by performing two cycles of heating and cooling under the differential scanning calorimetry (DSC) conditions described below, and measuring the glass transition temperature during the heating phase of the second cycle. The starting glass transition temperature (TIG) was defined as the intersection of a straight line extending from the low-temperature baseline to the high-temperature side and the tangent line at the inflection point. The measurement start temperature was 30°C, the heating rate was 10°C / min, the target temperature was 250°C, and the cooling rate was 20°C / min. All units are shown in °C. The measuring device used was a differential scanning calorimeter (DSC, manufactured by Hitachi High-Tech Science Corporation, model "DSC7020").

[0087] <Method for measuring weight-average molecular weight> The weight-average molecular weight (Mw) of various resins was measured by gel permeation chromatography. Specifically, an LC-20AD system (Shimadzu Corporation) gel permeation chromatography apparatus was used, connected to an LF-804 column (Shodex Corporation). The column temperature was set to 40°C. A RID-10A (Shimadzu Corporation) radioisotope detector was used. Chloroform was used as the eluent, and a calibration curve was created using standard polystyrene (Tosoh Corporation). If the above-mentioned gel permeation chromatography apparatus, column, and detector are difficult to obtain, measurements should be performed using other equipment with equivalent performance.

[0088] <Measurement of Meltmass Flow Rate (MFR)> The melt mass flow rate (MFR) of the obtained pellets (resin composition) was measured using a melt indexer at a temperature of 230°C and a load of 3.8 kg. The unit is expressed as g / 10 min. The melt indexer used was the "Melt Indexer G-02" manufactured by Toyo Seiki Co., Ltd.

[0089] <Manufacturing of flat molded products> The obtained pellets (resin composition) were melted and kneaded at a cylinder temperature of 260°C using a vented twin-screw injection molding machine (Sodick "PE-100", twin-screw diameter 29 mm, meshing type, co-rotating, plunger diameter 28 mm), and a flat molded body (100 × 100 × 1 mm) was formed at a mold temperature of 80°C.

[0090] <Haze Measurement> Using a haze meter, the haze (in %) of the flat molded body obtained above was measured under the condition of a D65 light source and a 10° field of view. A haze meter, model "HM-150" manufactured by Murakami Color Technology Research Institute, was used.

[0091] <Measurement of refractive index of resins and resin compositions> The refractive index of the resin composition was measured by polarization diffraction. The refractive index of the obtained flat molded body was determined using an automated thin-film analyzer to detect light at a wavelength of 589 nm. The refractive index of the resin was also measured in the same manner as described above, by forming a flat molded body. For measuring the refractive index, a spectroscopic ellipsometer Auto SE (manufactured by HORIBA Corporation) was used as an automated thin-film measurement device.

[0092] <Pencil hardness> The flat molded body prepared as described above was subjected to a pencil hardness test using a pencil hardness tester in accordance with JIS K5600-5-4:1999, and its pencil hardness was determined by measuring a 750g load. The evaluation was conducted by five experts, and the decision was made by majority vote.

[0093] <Manufacturing of multilayer materials without a hard coat layer> Multilayer bodies were molded using a multilayer extrusion apparatus that included a 32mm diameter single-screw extruder, a 65mm diameter single-screw extruder, a feed block connected to all extruders, a 650mm wide T-die connected to the feed block, and a multi-manifold die connected to each extruder. The resin compositions of Examples 1-4 or Comparative Examples 1-6 shown in Tables 1-3 were introduced into the 32mm diameter single-screw extruder and extruded at a cylinder temperature of 250°C and a discharge rate of 3.6 kg / h. In addition, polycarbonate resin (T-1380) was continuously introduced into the 65mm diameter single-screw extruder and extruded at a cylinder temperature of 280°C and a discharge rate of 32.4 kg / h. The feed block connected to all extruders was equipped with two types of two-layer distribution pins and was extruded and laminated at a temperature of 270°C. The material was extruded into a sheet using a T-die connected to the end at a temperature of 270°C, and cooled while transferring a mirror finish using three mirror-finishing rolls at temperatures of 110°C, 120°C, and 160°C from the upstream side, thereby obtaining a multilayer body consisting of a polycarbonate resin layer and an acrylic resin layer formed from the above resin composition. The overall thickness of the central part of the obtained multilayer body was 1000 μm, and the thickness of the acrylic resin layer was 100 μm.

[0094] <Flow Mark Appearance> In the above-mentioned <manufacturing of multilayer structures>, the presence or absence of flow marks was confirmed visually. The evaluation was conducted by five experts, and the decision was made by majority vote. A: No flow marks were observed. B: Flow marks were observed.

[0095] <Interference fringes> Black tape (3M Japan, black vinyl tape model number 117BLA) was attached to the layer side of the multilayer polycarbonate resin obtained above, and a three-wavelength fluorescent lamp (Technica Co., Ltd., Inverter Light 60, AL-60231) was shone from the polycarbonate resin layer side to evaluate the presence or absence of interference fringes. The evaluation was performed by five experts and decided by majority vote. A: Interference fringes were either not visible or very faint. B: Other than A above, such as strongly observed interference fringes.

[0096] <Post-heat warping (warping under high temperature and high humidity conditions)> A 10cm x 6cm specimen was cut from near the center of the multilayer material without the hard coat layer obtained above. The specimen was placed in a two-point support holder and immersed in an environmental testing machine set to 23°C and 50% relative humidity for more than 24 hours to adjust its condition, after which the warp was measured. This value was taken as the warp amount before treatment. Next, the specimen was placed in a holder and immersed in an environmental testing machine set to 85°C and 85% relative humidity, and held in that state for 120 hours. Furthermore, the holder was moved to an environmental testing machine set to 23°C and 50% relative humidity, and after being held in that state for 4 hours, the warp was measured again. This value was taken as the warp amount after treatment. For warp measurement, a 3D shape measuring machine equipped with an electric stage was used. The removed specimen was placed horizontally in a convex position upwards, scanned at 1mm intervals, and the bulge in the center was measured as the warp. The difference in warpage before and after processing, i.e., (warpage after processing) - (warpage before processing), was evaluated as the amount of warpage change. In this evaluation, a "-" sign was used if the flat molded body (acrylic resin layer) side was convex, and a "+" sign was used if the polycarbonate resin layer was convex. A: The absolute value of the change in warpage was less than 350 μm. B: The absolute value of the change in warpage was between 350 μm and 600 μm. C: The absolute value of the change in warpage was 600 μm or more.

[0097] <Manufacturing of multilayer materials with hard coat layers> A coating was prepared by adding 1% by mass of a photopolymerization initiator (product name: I-184 [compound name: 1-hydroxycyclohexylphenyl ketone] manufactured by BASF Corporation) to a total of 100 parts by mass of a mixture of 60 parts by mass of a hexafunctional urethane acrylate oligomer (product name: U6HA, manufactured by Shin Nakamura Chemical Industry Co., Ltd.), 35 parts by mass of PEG200# diacrylate (product name: 4EG-A, manufactured by Kyoeisha Chemical Co., Ltd.), and 5 parts by mass of an oligomer containing fluorine-containing groups, hydrophilic groups, lipophilic groups, and UV-reactive groups (product name: RS-90, manufactured by DIC Corporation). This coating was then applied to the surface of the multilayer acrylic resin layer without a hard coat layer prepared above using a bar coater, and a metal halide lamp (20 mW / cm²) was used. 2The hard coat was cured by applying () for 5 seconds. The thickness of the hard coat layer was 6 μm.

[0098] <Heat press formability 1 (120℃, 3-minute bend)> For the multilayer body with a hard coat layer obtained above, a convex (male) mold and a concave (female) mold with a radius of curvature of 50 mmR were fabricated. The multilayer body with the hard coat layer was preheated at 90°C for 1 minute before molding. It was then placed in the mold with the hard coat layer facing the convex side, pressed at a mold temperature of 120°C for 3 minutes, and allowed to cool naturally to produce a hot-press molded product. The cracks in the bent portions of the above-mentioned hot-pressed molded products were visually evaluated. The evaluation was conducted by five experts, and the decision was made by majority vote. A: No cracks were found in the bent portion of the hot-pressed product. B: Cracks were found in the bent portion of the hot-pressed product.

[0099] <Heat press formability 2 (115℃, 7 minutes heat bending)> For the multilayer body with a hard coat layer obtained above, a convex (male) mold and a concave (female) mold with a radius of curvature of 50 mmR were fabricated. The multilayer body with the hard coat layer was preheated at 90°C for 1 minute before molding. It was then placed in the mold with the hard coat layer facing the convex side, pressed at a mold temperature of 115°C for 7 minutes, and allowed to cool naturally to produce a hot-press molded product. The cracks in the bent portions of the above-mentioned hot-pressed molded products were visually evaluated. The evaluation was conducted by five experts, and the decision was made by majority vote. A: No cracks were found in the bent portion of the hot-pressed product. B: Cracks were found in the bent portion of the hot-pressed product.

[0100] <Springback after heat bending> The hot-press molded body produced using the above hot-press formability method 1 was placed along a 50mmR cylinder, and the springback was judged to pass or fail according to the following criteria, with A being considered a pass. The evaluation was conducted by five experts, and the decision was made by majority vote. A: It conforms to the cylinder (without springback). B: Does not conform to the cylinder (springback occurs).

[0101] <Overall Rating> Based on the results of the above-mentioned post-moist heat warping, hot press formability 1 (120°C), hot press formability 2 (115°C), and post-heat bending springback, the evaluation was performed as follows. A: All of the above evaluations are A. B: The three evaluations mentioned above are A. C: Other than A and B above

[0102] [Table 1]

[0103] [Table 2]

[0104] [Table 3] [Explanation of symbols]

[0105] 1 Multilayer body 2 Base material 3 Flat plate shaped body 4. Hard court layer

Claims

1. The copolymer (A) is present in a quantity of 30 to 90 parts by mass, and the copolymer (B) is present in a quantity of 70 to 10 parts by mass. The copolymer (A) is a copolymer comprising 36 to 96% by mass of methyl methacrylate units, 1 to 60% by mass of styrene units, and 3 to 63% by mass of N-phenylmaleimide units. The copolymer (B) is a copolymer containing 70 to 90% by mass of styrene units and 10 to 30% by mass of acrylonitrile units. A resin composition in which the total content of copolymer (A) and copolymer (B) accounts for 90% by mass or more of the resin composition.

2. The resin composition according to claim 1, wherein the haze when the resin composition is molded to a thickness of 1 mm is 5.0% or less.

3. The resin composition according to claim 1 or 2, wherein the refractive index of light with a wavelength of 589 nm is 1.54 or higher.

4. The resin composition according to any one of claims 1 to 3, wherein the onset glass transition temperature (TiG) determined by differential scanning calorimetry is 115°C or higher.

5. The resin composition according to any one of claims 1 to 4, wherein the resin composition is molded to a thickness of 1 mm, and the pencil hardness measured using a pencil hardness tester in accordance with JIS K5600-5-4:1999 under a 750 g load is F or higher.

6. A resin composition according to any one of claims 1 to 5, wherein the melt mass flow rate (MFR) at 230°C and a load of 3.8 kg is 1.0 g / 10 min or more.

7. The resin composition according to any one of claims 1 to 6, further comprising 0.001 to 0.5 parts by mass of an antioxidant and / or a mold release agent in total, per 100 parts by mass of the resin composition.

8. The resin composition comprises the copolymer (A) and the copolymer (B), and at least one selected from the group consisting of an antioxidant, a mold release agent, a thermoplastic resin other than copolymer (A) and copolymer (B), an ultraviolet absorber, a flame retardant, a flame retardant aid, a colorant, an antistatic agent, a fluorescent whitening agent, an antifogging agent, a flow improver, a plasticizer, a dispersant, an antibacterial agent, an antiblocking agent, an impact improver, a sliding improver, a hue improver, and an acid trapper, The total content of antioxidants and / or release agents is 0 to 0.5 parts by mass per 100 parts by mass of the resin composition. The total content of the thermoplastic resin other than copolymer (A) and copolymer (B), ultraviolet absorber, flame retardant, flame retardant aid, colorant, antistatic agent, fluorescent whitening agent, antifogging agent, flow improver, plasticizer, dispersant, antibacterial agent, antiblocking agent, impact improver, sliding improver, hue improver, and acid trapper is 0 to 5% by mass of the resin composition. The resin composition according to any one of claims 1 to 7.

9. A flat molded article formed from the resin composition according to any one of claims 1 to 8.

10. A multilayer body comprising the plate-shaped molded body described in claim 9 and at least one other layer.

11. The multilayer according to claim 10, wherein the other at least one layer is a layer containing polycarbonate resin.

12. The multilayer according to claim 11, wherein the starting glass transition temperature (TiG) of the polycarbonate resin, as determined by differential scanning calorimetry, is 130°C or less.

13. The multilayer according to claim 11 or 12, wherein the polycarbonate resin has an end structure represented by formula (1). 【Chemistry 1】 (In formula (1), R １ R represents an alkyl group having 8 to 36 carbon atoms, or an alkenyl group having 8 to 30 carbon atoms. ２ Each of these independently represents a halogen atom, an alkyl group with 1 to 20 carbon atoms, or an alkyl group with 6 to 12 carbon atoms. n represents an integer from 0 to 4. * indicates a bonding site with another part.

14. Furthermore, the multilayer body according to any one of claims 10 to 13, further comprising a hard coat layer.

15. The multilayer body according to any one of claims 10 to 14, wherein one or both sides of the multilayer body are treated with one or more of the following: anti-fingerprint treatment, anti-reflective treatment, anti-glare treatment, weather-resistant treatment, anti-static treatment, anti-fouling treatment, and anti-blocking treatment.

16. A molded article comprising a flat molded body according to claim 9, or a multilayer body according to any one of claims 10 to 15.

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