WO2025225722A1 - Thermoplastic polymer composition, sheet or film, laminate, and method for producing same - Google Patents

Abstract

The present invention addresses the problem of providing a thermoplastic polymer composition that can be shaped into a highly transparent sheet or film exhibiting low anisotropy, and that has good sheet or film shape formability.

Description

Thermoplastic polymer composition, sheet or film, laminate and method for producing same

This patent application claims priority under the Paris Convention to Japanese Patent Application No. 2024-072203 (filing date: April 26, 2024), the entire contents of which are incorporated herein by reference.
The present invention relates to a thermoplastic polymer composition. The present invention further relates to a sheet or film using the thermoplastic polymer composition, a laminate, a method for producing the same, and a paint protection sheet or film including the laminate.

Paint protection films, chip-resistant films, and vehicle exterior protection films are used to protect the painted surfaces and bodies of automobiles from stone chips, scratches, dirt, etc. Such protective films for the exterior of automobiles and other vehicles are required to be flexible, scratch-resistant, highly transparent, and weather-resistant and durable enough to withstand long-term outdoor use. Polyurethane resin is widely used as the base material for these protective films.

However, polyurethane resins are expensive and subject to cost constraints, so active research is being conducted into alternatives to polyurethane resin substrates, such as thermoplastic elastomers. However, when molded into films or sheets, some are weak to tension in certain directions, which can cause problems in terms of handling.

Among thermoplastic elastomers, styrene-based thermoplastic elastomers, such as styrene-butadiene-styrene block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), and hydrogenated products thereof, are widely used in a variety of applications because they are inexpensive and have excellent flexibility, rubber elasticity, recyclability, and the like, and are also used as a substitute for polyurethane resin substrates in films for protecting vehicle exteriors (see Patent Document 1).
Furthermore, among styrene-based thermoplastic elastomers, block copolymers in which the styrene block is replaced with a polymer block mainly composed of α-methylstyrene are known to have excellent scratch resistance and abrasion resistance, and when mixed with an acrylic resin, a thermoplastic polymer composition can be obtained that has good moldability, flexibility, and rubber elasticity, and that, when made into a sheet or film, can have further improved transparency and mechanical properties while maintaining scratch resistance and abrasion resistance comparable to those of polyurethane-based thermoplastic elastomers and polyester-based thermoplastic elastomers (see Patent Document 2).

JP 2023-150863 A Patent No. 5736529

The surface protection film of Patent Document 1 is said to have excellent workability, flexibility, and extensibility without using polyurethane resin. However, as a result of investigations by the present inventors, it was found to have problems such as poor transparency when an adhesive layer is provided, excessively high flexibility resulting in poor workability due to a difference in feel, and film thickness fluctuations occurring during film formation, making it difficult to obtain a uniform film, particularly at a thickness of 300 μm or less.
Furthermore, although the composition of Patent Document 2 is said to have excellent moldability, the inventors have conducted studies and found that the composition has problems such as the following: when film molding is performed at low temperatures, anisotropy occurs in the film, resulting in a large difference in tear strength between the MD and TD directions; and when film molding is performed at high temperatures to eliminate the anisotropy of the film, fluctuations in film thickness occur, making it difficult to obtain a uniform film, particularly at a thickness of 300 μm or less.

The object of the present invention is to provide a thermoplastic polymer composition that can be molded into a sheet or film that is highly transparent and exhibits low anisotropy, and also has good processability for molding into a sheet or film.

As a result of extensive investigations, the present inventors have found that the above-mentioned problems can be solved by adding specific amounts of an acrylic resin having a relatively low degree of polymerization and an acrylic resin having a relatively high degree of polymerization to a block copolymer containing a polymer block mainly composed of α-methylstyrene units. Based on this finding, the present inventors have furthered their investigations and arrived at the present invention.
The present invention can be configured in the following manner.
[Aspect 1] A block copolymer (I) containing a polymer block P mainly composed of α-methylstyrene units and a hydrogenated or non-hydrogenated polymer block Q mainly composed of conjugated diene or isobutylene units and having a weight average molecular weight of 30,000 to 200,000, an acrylic resin (II) containing 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith and having an average degree of polymerization of 400 to 2,000, an acrylic resin (III) containing 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith and having an average degree of polymerization of 6,000 to 40,000, and a softener (IV) are reacted with compounds represented by the following formulas (a), (b), and (c):

0.1≦W(II)/W(I)≦2.4 (a)
0.001≦W(III)/(W(I)+W(II))≦0.04 (b)
0≦W(IV)/(W(I)+W(II)+W(III)+W(IV))≦0.5 (c)
[In the formula, W(I), W(II), W(III), and W(IV) represent the contents (by mass) of the block copolymer (I), the acrylic resin (II), the acrylic resin (III), and the softener (IV) in the thermoplastic polymer composition, respectively.]
A thermoplastic polymer composition comprising the above components in a proportion satisfying the above formula:
[Aspect 2] A thermoplastic polymer composition comprising a block copolymer (I) having a weight-average molecular weight of 30,000 to 200,000, which comprises a polymer block P mainly composed of α-methylstyrene units and a hydrogenated or non-hydrogenated polymer block Q mainly composed of conjugated diene or isobutylene units, an acrylic resin (II) containing 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith, and having an average degree of polymerization of 400 to 2,000, an acrylic resin (III) containing 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith, and having an average degree of polymerization of 6,000 to 40,000, and a softener (IV), wherein the film thickness variation coefficient measured in accordance with JIS K 7130:1999 using a film extruded to a thickness of 150 μm is 5% or less, and A thermoplastic polymer composition having a tear strength in both the MD direction and the TD direction of 400 N/cm or more at room temperature, as measured using an unnotched angle-shaped test piece in accordance with JIS J 6252-1:2015.
[Embodiment 3] The thermoplastic polymer composition according to embodiment 1 or 2, wherein the acrylic resin (II) has a melt flow rate of 5 to 25 g/10 min at 230° C. and 37.3 N.
[Embodiment 4] The thermoplastic polymer composition according to any one of embodiments 1 to 3, wherein when a strand is extruded at an extrusion temperature of 230°C through a capillary having a diameter of 1 mm and a length of 10 mm at a piston speed of 5 mm/min using a melt tension measurement device of a capillary rheometer and taken up, the tension at which the strand breaks is 30 kPa or more.
[Embodiment 5] The thermoplastic polymer composition according to any one of embodiments 1 to 4, wherein when a strand is extruded at an extrusion temperature of 230°C through a capillary having a diameter of 1 mm and a length of 10 mm at a piston speed of 5 mm/min using a melt tension measurement device of a capillary rheometer and is taken up, the speed at which the strand breaks is 40 m/min or more.
[Embodiment 6] The thermoplastic polymer composition according to any one of embodiments 1, 3 to 5, wherein the tear strength in the MD direction and the tear strength in the TD direction are both 400 N/cm or more at room temperature, as measured using a film extruded to a thickness of 150 μm in accordance with JIS K 6252-1:2015 using an unnotched angle-shaped test specimen.
[Embodiment 7] A sheet or film made of the thermoplastic polymer composition according to any one of embodiments 1 to 6.
[Embodiment 8] A block copolymer (I) containing a polymer block P mainly composed of α-methylstyrene units and a hydrogenated or non-hydrogenated polymer block Q mainly composed of conjugated diene or isobutylene units and having a weight average molecular weight of 30,000 to 200,000, a methacrylic resin (II) consisting of 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith and having an average degree of polymerization of 400 to 2,000, a methacrylic resin (III) consisting of 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith and having an average degree of polymerization of 6,000 to 40,000, and a softener (IV) are reacted with compounds represented by the following formulas (d), (e), and (f):
0.1≦W(II)/W(I)≦2.4 (d)
0.001≦W(III)/(W(I)+W(II))≦0.04 (e)
0≦W(IV)/(W(I)+W(II)+W(III)+W(IV))≦0.5 (f)
[In the formula, W(I), W(II), W(III), and W(IV) represent the contents (by mass) of the block copolymer (I), the methacrylic resin (II), the methacrylic resin (III), and the softener (IV) in the thermoplastic polymer composition, respectively.]
a layer (B) made of a cured resin, and a layer (C) made of a pressure-sensitive adhesive, wherein these are laminated in the order of (B)-(A)-(C).
[Aspect 9] The thicknesses of the layer (A) made of the thermoplastic polymer composition, the layer (B) made of the cured resin, and the layer (C) made of the pressure-sensitive adhesive are expressed by the following formulas (g) and (h):
0.02≦T(B)/T(A)≦0.30 (g)
0.04≦T(C)/(T(A)+T(B))≦0.50 (h)
[wherein T(A), T(B), and T(C) represent the thicknesses (mm) of the layer (A) made of the thermoplastic polymer composition, the layer (B) made of the cured resin, and the layer (C) made of the pressure-sensitive adhesive, respectively]
A laminate according to aspect 8, wherein the ratio satisfies the following.
[Embodiment 10] The laminate according to embodiment 8 or 9, wherein the layer (A) made of the thermoplastic polymer composition has a thickness of 100 to 300 μm.
[Embodiment 11] The laminate according to any one of embodiments 8 to 10, wherein the layer (C) made of the pressure-sensitive adhesive contains an acrylic pressure-sensitive adhesive.
[Aspect 12] The laminate according to aspect 11, wherein the acrylic pressure-sensitive adhesive contains an acrylic block copolymer (V) having at least one polymer block R composed of structural units derived from a methacrylic acid ester and at least one polymer block S composed of structural units derived from an acrylic acid ester.
[Embodiment 13] The laminate according to embodiment 12, wherein the content of the acrylic block copolymer (V) in the layer (C) made of the pressure-sensitive adhesive is 50% by mass or more.
[Embodiment 14] The laminate according to embodiment 12 or 13, wherein the content of the polymer block R in the acrylic block copolymer (V) is 10 to 50 mass %.
[Aspect 15] The laminate according to Aspect 8, wherein the layer (C) made of the pressure-sensitive adhesive contains an aromatic vinyl block copolymer (VI) containing a polymer block containing 50% by mass or more of structural units derived from an aromatic vinyl monomer and a hydrogenated or non-hydrogenated polymer block containing 50% by mass or more of structural units derived from a conjugated diene monomer.
[Embodiment 16] The layer (C) made of the pressure-sensitive adhesive is
Aromatic vinyl block copolymers (VI),
a tackifying resin (VII), and
Optionally, a softener (VIII)
into the following formulas (i) and (j):
0.1≦W(VII)/W(VI)≦3.0 (i)
0.0≦W(VIII)/(W(VI)+W(VII))≦1.0 (j)
[In the formula, W(VI), W(VII), and W(VIII) respectively represent the contents (by mass) of the block copolymer (VI), tackifier resin (VII), and softener (VIII) in the layer (C) composed of the pressure-sensitive adhesive composite.]
A laminate according to aspect 15, containing the compound in a ratio satisfying the following:
[Embodiment 17] The laminate according to any one of embodiments 8 to 16, wherein the layer (B) made of the cured resin contains a urethane (meth)acrylate resin.
[Embodiment 18] The laminate according to embodiment 17, wherein the urethane (meth)acrylate resin contains fluorine atoms and silicon atoms.
[Aspect 19] A method for producing a laminate according to any one of aspects 8 to 18, comprising laminating a layer (A) made of the thermoplastic polymer composition and a layer (C) made of a pressure-sensitive adhesive by melt co-extrusion.
[Embodiment 20] A protection film or protection sheet comprising the laminate according to any one of embodiments 8 to 18.

The present invention provides a thermoplastic polymer composition that can be molded into a sheet or film that is highly transparent and exhibits low anisotropy, and that also has good sheet or film molding processability. Furthermore, by laminating a cured resin and an adhesive, the thermoplastic polymer composition of the present invention can provide a laminate that has high abrasion resistance and stain resistance, as well as high adhesion and low adhesive residue to automotive steel sheets and polar resin sheets, exhibits little change over time, and can be co-extruded. The laminate of the present invention can be suitably used as a protection film or protection sheet.

As used in this specification, "mainly composed of" means that the component, structural unit, etc., accounts for 50% by mass or more of the total mass of the composition, polymer, etc.

The present invention provides a thermoplastic polymer composition comprising: a block copolymer (I) having a weight-average molecular weight of 30,000 to 200,000, a polymer block P mainly composed of α-methylstyrene units, and a hydrogenated or non-hydrogenated polymer block Q mainly composed of conjugated diene or isobutylene units; an acrylic resin (II) having an average degree of polymerization of 400 to 2,000, which contains 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith; an acrylic resin (III) having an average degree of polymerization of 6,000 to 40,000, which contains 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith; and a softener (IV). In a preferred embodiment, the thermoplastic polymer composition comprises a polymer represented by the following formulas (a), (b), and (c):
0.1≦W(II)/W(I)≦2.4 (a)
0.001≦W(III)/(W(I)+W(II))≦0.04 (b)
0≦W(IV)/(W(I)+W(II)+W(III)+W(IV))≦0.5 (c)
[In the formula, W(I), W(II), W(III), and W(IV) represent the contents (by mass) of the block copolymer (I), the acrylic resin (II), the acrylic resin (III), and the softener (IV) in the thermoplastic polymer composition, respectively.]
The thermoplastic polymer composition contains the above components in a proportion that satisfies the above formula.

The reason why the effects of the present invention are achieved by adding specific amounts of an acrylic resin with a relatively low degree of polymerization and an acrylic resin with a relatively high degree of polymerization to a block copolymer containing a polymer block mainly composed of α-methylstyrene units is not clear, but is presumed to be as follows.
It is generally known that it is difficult to uniformly finely disperse an acrylic block copolymer in a styrene block copolymer. However, a styrene block copolymer containing a polymer block mainly composed of α-methylstyrene can uniformly maintain an acrylic resin with relatively high fluidity (e.g., MFR of 10 g/10 min or more (230°C, 37.3 N)) as an island structure in its continuous phase. If an acrylic resin with lower fluidity is present in the styrene block copolymer, the acrylic resin with lower fluidity is difficult to disperse in the continuous phase of the styrene block copolymer. Therefore, the acrylic resin is extruded from the continuous phase, and using the relatively high fluidity acrylic resin forming the fine island structure as a foothold, it forms a net-like structure that surrounds the island structure while more firmly maintaining it, thereby achieving the effects of the present invention.

Each component will be explained in turn below.
In the following description, the preferred provisions can be selected arbitrarily, and a combination of preferred provisions can be considered more preferred.

[Block copolymer (I)]
The block copolymer (I) used in the present invention is a block copolymer having a weight average molecular weight of 30,000 to 200,000, which comprises a polymer block P mainly composed of α-methylstyrene units and a hydrogenated or non-hydrogenated polymer block Q mainly composed of conjugated diene compound units or isobutylene units.
Use of block copolymer (I) significantly improves transparency, ease of coating, and mechanical properties compared to a block copolymer or a hydrogenated product thereof having a polymer block mainly composed of units other than α-methylstyrene units, for example, styrene units, instead of polymer block P.
The total content of polymer block P and polymer block Q in block copolymer (I) is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, without taking into account the presence of a coupling agent residue, which will be described later.

(Polymer Block P)
Polymer block P constituting a part of the block copolymer (I) is mainly composed of α-methylstyrene units. As used herein, "mainly composed of" means that the polymer block P contains 50% by mass or more of α-methylstyrene units based on the total mass of the polymer block P. From the viewpoints of transparency, ease of coating, and mechanical properties of the thermoplastic polymer composition, the content of α-methylstyrene units in the polymer block P is preferably 70% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, based on the total mass of the polymer block P.

The polymer block P may contain other monomer units in an amount of 50% by mass or less, 30% by mass or less, 10% by mass or less, or 5% by mass or less, based on the total mass of the polymer block P, as long as the object of the present invention is not impaired. Examples of other monomers include at least one selected from aromatic vinyl compounds such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, diphenylethylene, 1-vinylnaphthalene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, and 4-(phenylbutyl)styrene; conjugated diene compounds such as butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene; and vinyl compounds such as isobutylene. When the polymer block P contains other polymerizable monomer units, the configuration may be either random or tapered.

The weight-average molecular weight of polymer block P is preferably 2,000 to 20,000, and more preferably 3,000 to 15,000. If the weight-average molecular weight of polymer block P is 2,000 or more, the compression set of the thermoplastic polymer composition at high temperatures is good. If it is 20,000 or less, the melt viscosity of block copolymer (I) does not become too high, making it easy to melt-mix with other components and resulting in excellent processability. Note that the weight-average molecular weight referred to in this specification is the molecular weight calculated in terms of standard polystyrene as determined by gel permeation chromatography (GPC).

The content of polymer block P in block copolymer (I) is preferably 5 to 70% by mass, more preferably 10 to 65% by mass, even more preferably 20 to 60% by mass, and particularly preferably 25 to 55% by mass, based on the total mass of polymer block P and polymer block Q. If the content of polymer block P is 5% by mass or more, the mechanical properties of the thermoplastic polymer composition will be good, good compression set will be obtained at high temperatures, and excellent heat resistance will be achieved. If the content is 70% by mass or less, the melt viscosity of block copolymer (I) will not be too high, facilitating melt-mixing with other components, and when formed into a thermoplastic polymer composition, excellent flexibility will be achieved.

(Polymer Block Q)
The polymer block Q constituting a part of the block copolymer (I) is mainly composed of conjugated diene compound units or isobutylene units, preferably mainly composed of conjugated diene compound units. Here, "mainly composed of" means that the polymer block Q contains 50% by mass or more of conjugated diene compound units or isobutylene units based on the total mass of the polymer block Q. The content of conjugated diene compound units or isobutylene units in the polymer block Q is preferably 70% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, based on the total mass of the polymer block Q.

The conjugated diene compound forming the conjugated diene compound unit may be at least one selected from the group consisting of butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. Among these, butadiene, isoprene, or a mixture of butadiene and isoprene is preferred, with butadiene being more preferred. When the conjugated diene compound unit is composed of two or more types, the configuration may be random, block, or tapered.

Furthermore, polymer block Q may be a hydrogenated product obtained by hydrogenating an unhydrogenated product (hereinafter, sometimes abbreviated as "hydrogenation"). Hydrogenation is preferred from the viewpoint of improving heat resistance and weather resistance, etc. The hydrogenation rate (hydrogenation rate) is not particularly limited, but preferably 70 mol % or more of the carbon-carbon double bonds based on the conjugated diene compound units in all polymer blocks Q are hydrogenated, more preferably 80 mol % or more, more preferably 85 mol % or more, even more preferably 90 mol % or more, and particularly preferably 95 mol % or more. The hydrogenation rate of carbon-carbon double bonds in polymer block Q is a value calculated using nuclear magnetic resonance spectroscopy ( ¹ H-NMR spectroscopy), and the same applies hereinafter.

Furthermore, polymer block Q may contain units of polymerizable monomers other than conjugated diene compound units and isobutylene units, provided that the content of these units is 50% by mass or less, 30% by mass or less, 10% by mass or less, or 5% by mass or less, based on the total mass of polymer block Q, within a range that does not impair the objectives of the present invention. Examples of such monomers include at least one aromatic vinyl compound selected from styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, diphenylethylene, 1-vinylnaphthalene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, etc. When polymer block Q contains monomers other than conjugated diene compound units and isobutylene units, the morphology may be either random or tapered.

The content of polymer block Q in block copolymer (I) is preferably 30 to 95% by mass, more preferably 35 to 90% by mass, even more preferably 40 to 80% by mass, and particularly preferably 45 to 75% by mass, based on the total mass of polymer blocks P and Q. When the content of polymer block Q is 30% by mass or more, the melt viscosity of block copolymer (I) does not become too high, and melt-mixing with other components is easy. On the other hand, when the content of polymer block Q is 95% by mass or less, excellent compression set at high temperatures is obtained when the block copolymer (I) is formed into a thermoplastic polymer composition.
The weight-average molecular weight (Mw) of the polymer block Q is preferably 9,000 to 190,000. When the weight-average molecular weight of the polymer block Q is 9,000 or more, the heat resistance of the thermoplastic polymer composition is good, and when the weight-average molecular weight is 190,000 or less, the melt viscosity of the block copolymer (I) is not too high, which facilitates mixing with other components and results in excellent processability.

(Bonding Mode Between Polymer Block P and Polymer Block Q)
The bonding mode between the polymer block P and the polymer block Q in the block copolymer (I) may be linear, branched, radial, or any combination thereof, and is preferably linear, branched, or a combination thereof.
For example, when polymer block P is represented by P and polymer block Q is represented by Q, examples include P-Q diblock copolymers, P-Q-P triblock copolymers, P-Q-P-Q tetrablock copolymers, and (P-Q)nX copolymers (X represents a coupling agent residue, and n represents an integer of 3 or more). Block copolymers with these bonding modes can be used alone or in combination of two or more. Among these, P-Q-P triblock copolymers or a mixture of P-Q-P triblock copolymers and P-Q diblock copolymers are preferred as block copolymer (I).

Herein, in this specification, when polymer blocks of the same type are linearly bonded via a divalent coupling agent or the like, the entire bonded polymer blocks are treated as a single polymer block. Accordingly, polymer blocks that should strictly be expressed as Y-X-Y (X represents a coupling agent residue), including the examples above, are expressed as Y as a whole, unless there is a particular need to distinguish them from a single polymer block Y. Since this type of polymer block containing coupling agent residues is treated as above in this specification, for example, a block copolymer containing coupling agent residues that should strictly be expressed as Y-Z-X-Z-Y (X represents a coupling agent residue) is expressed as Y-Z-Y and is treated as an example of a triblock copolymer.

Furthermore, within the scope of the present invention, block copolymer (I) may contain polymer blocks R composed of polymerizable monomers other than α-methylstyrene, conjugated diene compounds, and isobutylene, such as methyl methacrylate and styrene. In this case, when polymer block R is represented by R, examples of the block copolymer structure include P-QR triblock copolymers, P-Q-R-P tetrablock copolymers, and P-Q-P-R tetrablock copolymers.

(Properties of Block Copolymer (I))
In the thermoplastic polymer composition of the present invention, the weight-average molecular weight of the block copolymer (I) is 30,000 to 200,000. If the weight-average molecular weight is within this range, the resulting thermoplastic polymer composition can be excellent in all of transparency, ease of application, and mechanical properties. From this viewpoint, the weight-average molecular weight of the block copolymer (I) is preferably 40,000 to 150,000, more preferably 40,000 to 100,000.
The structure of the block copolymer (I) is not limited to a linear or branched structure.

There are no particular restrictions on the method for producing block copolymer (I). Furthermore, in the present invention, known block copolymers (I) can also be used without particular restrictions. For example, the Septon (registered trademark) Q series manufactured by Kuraray Co., Ltd. can be mentioned.

[Acrylic resin (II)]
The acrylic resin (II) used in the present invention contains 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith, and has an average degree of polymerization of 400 to 2,000. Usually, the average degree of polymerization can be determined by dissolving the resin in a solvent and converting the viscosity of the solution.
The content of methyl methacrylate units in the acrylic resin (II) is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. It may be 90% by mass or more, or may be 100% by mass, i.e., composed solely of methyl methacrylate units.

Examples of copolymerizable vinyl monomers include olefin compounds such as ethylene and propylene; acrylic acid or metal salts thereof; acrylic acid esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, s-butyl acrylate, t-butyl acrylate, and 2-ethylhexyl acrylate; methacrylic acid or metal salts thereof; methacrylic acid esters such as ethyl methacrylate, n-butyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, and cyclohexyl methacrylate; vinyl acetate; aromatic vinyl compounds such as styrene, α-methylstyrene, and p-methylstyrene; maleic anhydride; and maleimide compounds such as N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide. When these are copolymerized with methyl methacrylate, one type may be used alone, or two or more types may be used in combination. In the copolymer obtained by copolymerizing methyl methacrylate with another copolymerizable vinyl monomer, the ratio of the other copolymerizable vinyl monomer is preferably a ratio that does not significantly change the properties of the acrylic resin (II), and specifically, is 50% by mass or less, preferably 30% by mass or less, and more preferably 25% by mass or less.
As the acrylic resin (II), a combination of at least one selected from ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), and ethylene-butyl acrylate copolymer (EBA) with polymethyl methacrylate (PMMA) is also preferred. As a copolymer to be used in combination with PMMA, EMA is more preferred from the viewpoint of facilitating viscosity adjustment of the thermoplastic polymer composition.

The average degree of polymerization of the acrylic resin (II) is 400 to 2,000, preferably 800 to 1,200. If the average degree of polymerization is higher than this, the viscosity of the composition after blending increases, making melt extrusion difficult, and it becomes difficult to finely disperse the acrylic resin (II) during blending, resulting in a decrease in transparency. If the average degree of polymerization is lower than this, drawdown is likely to occur, making melt extrusion difficult.
The melt flow rate of the acrylic resin (II), measured in accordance with ISO 1133-1:2011 under conditions of 230°C and 37.3 N, is preferably 5 to 25 g/10 min, more preferably 5 to 20 g/10 min, and even more preferably 5 to 15 g/10 min. If the melt flow rate is outside this range, the fluidity of the composition will vary, making it difficult to mold it into a sheet or film shape.

Acrylic resin (II) can be produced by common polymerization techniques such as solution polymerization, emulsion polymerization, and suspension polymerization, and there are no particular restrictions on the production method. Furthermore, in the present invention, known acrylic resins (II) can also be used without particular restrictions. Examples include the ACRYPET (registered trademark) series manufactured by Mitsubishi Rayon Co., Ltd., the DELPET (registered trademark) series manufactured by Asahi Kasei Chemicals Corporation, the SUMIPEX (registered trademark) series manufactured by Sumitomo Chemical Co., Ltd., and the PARAPET (registered trademark) series manufactured by Kuraray Co., Ltd.

[Acrylic resin (III)]
The acrylic resin (III) used in the present invention contains 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith, and has an average degree of polymerization of 6,000 to 40,000.
The content of methyl methacrylate units in the acrylic resin (III) is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. It may be 90% by mass or more, or may be 100% by mass, i.e., may be composed of only methyl methacrylate units.

Examples of copolymerizable vinyl monomers include olefin compounds such as ethylene and propylene; acrylic acid or metal salts thereof; acrylic acid esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, s-butyl acrylate, t-butyl acrylate, and 2-ethylhexyl acrylate; methacrylic acid or metal salts thereof; methacrylic acid esters such as ethyl methacrylate, n-butyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, and cyclohexyl methacrylate; vinyl acetate; aromatic vinyl compounds such as styrene, α-methylstyrene, and p-methylstyrene; maleic anhydride; and maleimide compounds such as N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide. When these are copolymerized with methyl methacrylate, one type may be used alone, or two or more types may be used in combination. In the copolymer obtained by copolymerizing methyl methacrylate with another copolymerizable vinyl monomer, the ratio of the other copolymerizable vinyl monomer is preferably a ratio that does not significantly change the properties of the acrylic resin (III), and specifically, is 50% by mass or less, preferably 30% by mass or less, and more preferably 25% by mass or less.
As the acrylic resin (III), it is also preferable to use at least one selected from ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), and ethylene-butyl acrylate copolymer (EBA) in combination with polymethyl methacrylate (PMMA).

The average degree of polymerization of the acrylic resin (III) is 6,000 to 40,000, preferably 8,000 to 36,000, and more preferably 10,000 to 32,000. If the average degree of polymerization is lower than this, it may become difficult for the acrylic resin (III) to form a net-like structure independently from the acrylic resin (II), resulting in a decrease in film transparency and insufficient improvement in film formability (film thickness stability, high melt tension, good extensibility). On the other hand, if the average degree of polymerization of the acrylic resin (III) is higher than this, it may become difficult for the acrylic resin (III) to disperse during blending, resulting in a decrease in film transparency and insufficient improvement in film formability (film thickness stability, high melt tension, good extensibility).

Acrylic resin (III) can be produced by common polymerization techniques such as solution polymerization, emulsion polymerization, and suspension polymerization, and there are no particular restrictions on the production method. In addition, in the present invention, known acrylic resins (III) can also be used without particular restrictions. Examples include the Metablen (registered trademark) P series manufactured by Mitsubishi Chemical Corporation and the Kane Ace (registered trademark) PA series manufactured by Kaneka Corporation.

[Softener (IV)]
The softener (IV) used in the present invention can be any known softener, including hydrocarbon oils such as paraffinic, naphthenic, and aromatic oils; vegetable oils such as peanut oil and rosin; phosphate esters; low-molecular-weight polyethylene glycol; liquid paraffin; and hydrocarbon synthetic oils such as low-molecular-weight polyethylene, ethylene-α-olefin copolymer oligomer, liquid polybutene, liquid polyisoprene or its hydrogenated products, and liquid polybutadiene or its hydrogenated products. These may be used alone or in combination of two or more. Among these, paraffinic hydrocarbon oils and hydrocarbon synthetic oils such as ethylene-α-olefin copolymer oligomer are preferred. The kinematic viscosity of the softener (IV) at 40°C is preferably 50 to 1,000 mm ² /s, more preferably 50 to 800 mm ² /s, and even more preferably 80 to 600 mm ² /s, from the viewpoints of moldability and ease of application.

(Contents of Block Copolymer (I), Acrylic Resin (II), Acrylic Resin (III) and Softener (IV))
In a preferred embodiment of the thermoplastic polymer composition of the present invention, the block copolymer (I), the acrylic resin (II), the acrylic resin (III), and the softener (IV) are reacted with compounds represented by the following formulas (a), (b), and (c):
0.1≦W(II)/W(I)≦2.4 (a)
0.001≦W(III)/(W(I)+W(II))≦0.04 (b)
0≦W(IV)/(W(I)+W(II)+W(III)+W(IV))≦0.5 (c)
[In the formula, W(I), W(II), W(III), and W(IV) represent the contents (by mass) of the block copolymer (I), the acrylic resin (II), the acrylic resin (III), and the softener (IV) in the thermoplastic polymer composition, respectively.]
It contains in a proportion that satisfies the following.

In formula (a), if the value of "W(II)/W(I)," i.e., the ratio (mass ratio) of the content of acrylic resin (II) to block copolymer (I) in the thermoplastic polymer composition, is less than 0.1, the ease of application and mechanical properties will be insufficient, and if it exceeds 2.4, the flexibility, rubber elasticity, transparency, and mechanical properties of the thermoplastic polymer composition will be poor. The value of "W(II)/W(I)" is preferably 0.2 to 2.0, more preferably 0.3 to 1.8, even more preferably 0.4 to 1.6, and particularly preferably 0.6 to 1.3.

Furthermore, in formula (b), if the value of "W(III)/(W(I)+W(II))" (i.e., the ratio (mass ratio) of the content of acrylic resin (III) to the total content of block copolymer (I) and acrylic resin (II)) is less than 0.001, sufficient improvement in film formability will not be achieved. Furthermore, if it exceeds 0.04, the transparency of the composition may decrease, or the melt tension may become too high, making both ends of the melt curtain more likely to tear during molding. The value of "W(III)/(W(I)+W(II))" is preferably 0.005 to 0.04, more preferably 0.008 to 0.04, even more preferably 0.009 to 0.04, still more preferably 0.009 to 0.035, even more preferably 0.009 to 0.02, and particularly preferably 0.009 to 0.015.

In formula (c), when the value of "W(IV)/(W(I)+W(II)+W(III)+W(IV))", i.e., the ratio (mass ratio) of the content of the softener (IV) to the total content of the block copolymer (I), the acrylic resin (II), the acrylic resin (III), and the softener (IV), exceeds 0.5, the ease of application and mechanical properties become poor.
The lower limit of "W(IV)/(W(I)+W(II)+W(III)+W(IV))" is 0, and the softener (IV) does not have to be contained; however, from the viewpoints of transparency, ease of application, and moldability, it is preferable that the softener (IV) be contained, and the value of "W(IV)/(W(I)+W(II)+W(III)+W(IV))" is preferably 0.01 to 0.5, more preferably 0.01 to 0.3, and even more preferably 0.03 to 0.2.

[Other ingredients]
The thermoplastic polymer composition of the present invention may contain, as necessary, another thermoplastic polymer different from the block copolymer (I), the acrylic resin (II), and the acrylic resin (III). Examples of the other thermoplastic polymer include polyethylenes such as medium-density polyethylene and low-density polyethylene (LDPE); ethylene-α-olefin copolymers such as ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-heptene copolymer, ethylene-1-octene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-nonene copolymer, and ethylene-1-decene copolymer; ethylene-vinyl acetate copolymer; polypropylenes such as atactic polypropylene, isotactic polypropylene, and syndiotactic polypropylene; polyolefin resins such as ethylene-propylene random copolymer and ethylene-vinyl acetate copolymer; styrene resins such as polystyrene, poly(α-methylstyrene), and styrene-acrylonitrile copolymer; styrene block copolymers having a styrene block as a hard segment different from the block copolymer (I); polyphenylene oxide, polycarbonate, thermoplastic polyolefin elastomers, and crosslinked thermoplastic polyolefin elastomers. These may be used alone or in combination of two or more.
Among these, polyethylene and polypropylene are preferred, and polypropylene is more preferred. The melt flow rate of the polyethylene and polypropylene is preferably 5 to 60 g/10 min, more preferably 10 to 60 g/10 min.
When other thermoplastic polymers are contained, the content thereof is preferably 60% by mass or less, more preferably 50% by mass or less, based on the thermoplastic polymer composition.

Furthermore, the total content of block copolymer (I), acrylic resin (II), acrylic resin (III), and softener (IV) in the thermoplastic resin composition of the present invention is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 70% by mass or more, and may be 80% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass.

Furthermore, the thermoplastic polymer composition of the present invention may contain components other than those described above. Examples of such components include inorganic fillers such as talc, clay, mica, calcium silicate, glass, hollow glass spheres, glass fiber, calcium carbonate, magnesium carbonate, basic magnesium carbonate, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, zinc borate, dawsonite, ammonium polyphosphate, calcium aluminate, hydrotalcite, silica, diatomaceous earth, alumina, titanium oxide, iron oxide, zinc oxide, magnesium oxide, tin oxide, antimony oxide, barium ferrite, strontium ferrite, carbon black, graphite, carbon fiber, activated carbon, hollow carbon spheres, calcium titanate, lead zirconate titanate, silicon carbide, and mica; organic fillers such as wood flour and starch; and organic pigments.
Furthermore, the composition may further contain a heat stabilizer, a light stabilizer, an ultraviolet absorber, an antioxidant, a lubricant, a colorant, an antistatic agent, a flame retardant, a foaming agent, a water repellent, a waterproofing agent, a tackifying resin, an electrical conductivity imparting agent, a thermal conductivity imparting agent, an electromagnetic wave shielding agent, a fluorescent agent, an antiblocking agent, or an antibacterial agent, as necessary.

When the thermoplastic polymer composition of the present invention contains such other components (excluding the aforementioned "other thermoplastic polymers"), there are no particular restrictions on their content as long as the effects of the present invention are not significantly impaired. However, typically, the content is preferably 30 parts by mass or less, more preferably 20 parts by mass or less for each of the components (I) to (IV), and even more preferably 10 parts by mass or less for each of the components (I) to (IV), per 100 parts by mass of the total.

(Characteristics and properties of thermoplastic polymer compositions)
The thermoplastic polymer composition of the present invention preferably has a Shore A hardness of about 30 to 100 when measured at 23° C. using a pressed sheet having a thickness of 2 mm in accordance with JIS K 6253-3:2023.
The specific gravity measured using a 2 mm thick press sheet by method A in accordance with JIS K 7112-1:2023 is preferably about 0.9 to 1.10 g/cm ³ , making it suitable for use in a wide range of applications.
The melt flow rate (MFR) measured by Method A in accordance with JIS K 7210-1:2014 under conditions of 230°C and 21.2 N is preferably about 0.5 to 40 g/10 min, more preferably in the range of 0.5 to 35 g/10 min. When the MFR is in this range, the flowability and moldability are good.

When the thermoplastic polymer composition of the present invention is molded into a film having a thickness of 150 μm using an extruder, the difference between the maximum and minimum film thickness (film thickness variation) determined by the method described in the Examples is preferably 25 μm or less, more preferably 20 μm or less, even more preferably 17 μm or less, and even more preferably 15 μm or less.

Furthermore, a film having a thickness of 150 μm formed by an extruder using the thermoplastic polymer composition of the present invention has a film thickness variation coefficient, which is expressed as the ratio of film thickness variation to the average film thickness (actually measured value), of 5% or less, preferably 4% or less, more preferably 3% or less, and even more preferably 2% or less, calculated by the following formula:
(Film thickness variation coefficient) [%] = (Film thickness variation) / (Average film thickness) × 100
It can be found by:

Furthermore, when the thermoplastic polymer composition of the present invention is extruded at an extrusion temperature of 230°C through a capillary having a diameter of 1 mm and a length of 10 mm at a piston speed of 5 mm/min using a melt tension measurement device of a capillary rheometer and the strand is taken up, the tension at which the strand breaks is preferably 30 kPa or more, more preferably 40 kPa or more, and even more preferably 50 kPa or more. Moreover, the speed at which the strand breaks under the same conditions is preferably 40 m/min or more, more preferably 50 m/min or more, and even more preferably 60 m/min or more.
The tensile strength of the thermoplastic polymer composition of the present invention, measured in accordance with JIS K 6251:2023 using a dumbbell No. 3 at a tensile speed of 500 mm/min, is preferably 10 to 60 MPa, more preferably 15 to 60 MPa, and even more preferably 20 to 60 MPa.
Further, the breaking elongation under the same conditions is preferably about 180 to 500%.

Furthermore, the thermoplastic polymer composition of the present invention has a haze value of preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.2 or less, measured in accordance with JIS K7136:2000 using a film molded to a thickness of 150 μm using an extruder. The haze value can be 0.9 or less. In other words, a molded article obtained using the thermoplastic polymer composition of the present invention has excellent transparency.
The thermoplastic polymer composition of the present invention has a tear strength in both the MD direction and the TD direction, measured at 23°C in accordance with JIS K6252-1:2015 using a film formed to a thickness of 150 μm using an unnotched angle-shaped test piece, of preferably 400 N/cm or more, more preferably 430 N/cm or more, and even more preferably 450 N/cm or more.
Furthermore, the tear strength in the MD direction and the tear strength in the TD direction are each preferably 400 N/cm or more, more preferably 450 N/cm or more, and even more preferably 500 N/cm or more, and can also be 550 N/cm or more, and 600 N/cm or more.

(Method for producing thermoplastic polymer composition)
The thermoplastic polymer composition of the present invention can be produced by, but not limited to, the following method, for example.
Specifically, all components to be mixed are first melt-kneaded by a known method to produce pellets. For example, pellets of the thermoplastic polymer composition are obtained by melt-kneading the components using a kneading machine such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a Brabender mixer, an open roll mixer, or a kneader. The kneading temperature is generally preferably 160 to 280°C, and more preferably 190 to 260°C.

In the melt-kneading, for example, (1) all components constituting the thermoplastic polymer composition are dry-blended in advance using a mixer such as a high-speed mixer or a tumbler mixer before kneading, and then melt-kneaded all at once;
(2) A method in which the other components except the softener (IV) are first fed into an extruder to start melt-kneading, and then a predetermined amount of the softener (IV) is added to the extruder midway using a side feeder or the like, and then all the components are melt-kneaded;
(3) A method in which the components other than the acrylic resin (II) are melt-kneaded in advance, and then a predetermined amount of the acrylic polymer (II) is added to the extruder midway using a side feeder or the like, and then all the components are melt-kneaded:
Other methods may also be adopted.

The thermoplastic polymer composition thus obtained can be molded and processed using a variety of molding methods, such as injection molding (insert molding, two-color molding, sandwich molding, gas injection molding, etc.), extrusion molding, inflation molding, T-die film molding, lamination molding, blow molding, hollow molding, compression molding, and calendar molding.

The thermoplastic polymer composition of the present invention can be used, for example, in automotive interior and exterior parts such as instrument panels, rack and opinion boots, suspension boots, constant velocity joint boots, bumpers, side moldings, weather strips, mudguards, emblems, leather seats, floor mats, armrests, airbag covers, steering wheel coverings, belt line moldings, flush mounts, gears, and knobs; hoses and tubes such as pressure-resistant hoses, fire hoses, painting hoses, washing machine hoses, fuel tubes, oil and air pressure tubes, and dialysis tubes; grip materials for various products (e.g., scissors, screwdrivers, toothbrushes, pens, cameras, etc.); home appliance parts such as refrigerator gaskets, vacuum cleaner bumpers, mobile phone protective films, and waterproof bodies; copier feed rollers, It can be effectively used in a wide range of applications, including office machine parts such as take-up rollers; furniture such as sofas and chair seats; parts such as switch covers, casters, stoppers, and foot rubbers; building materials such as coated steel plates and coated plywood; sporting goods such as swimming goggles, snorkels, ski poles, ski boots, snowboard boots, ski and snowboard coverings, golf ball covers, various types of shoes, and shoe outer soles; medical supplies such as syringe gaskets and rolling tubes; industrial materials such as conveyor belts, electric belts, and pelletizer rolls; elastic parts for sanitary materials such as disposable diapers, poultices, and bands; band applications such as hair bands, wristbands, watch bands, and eyeglass bands; snow chains, electrical wire coverings, trays, films, sheets, stationery, toys, and everyday items.

The present invention also includes a sheet or film made from the above thermoplastic polymer composition.
Although there is generally no clear distinction between sheets and films, there is a tendency that a thickness of 200 μm or less is called a film, and anything thicker than that is called a sheet, and this is also true in the present invention.

From the viewpoints of transparency, ease of application, and mechanical properties, the method for producing a sheet or film preferably includes a molding step using a film molding machine that includes a static mixer. More specifically, the film molding is performed by positioning the film molding machine so that a static mixer is connected continuously to the outlet of a kneading machine similar to the single-screw extruder, twin-screw extruder, Banbury mixer, Brabender, open roll, kneader, etc., that are used when melt-kneading all of the components that make up the thermoplastic polymer composition of the present invention to produce pellets, and preferably the static mixer is positioned before the T-die. It is also possible to omit the pellet-making step and directly melt-knead and mold the film.

When molding a film or sheet, from the perspective of increasing transparency, the cylinder temperature in the static mixer is preferably 180 to 270°C, more preferably 190 to 260°C, and even more preferably 200 to 250°C. The die head temperature is preferably 210 to 270°C, more preferably 220 to 260°C. The screw speed is preferably 20 to 70 rpm, more preferably 20 to 60 rpm. Furthermore, the cast roll temperature is preferably 10 to 110°C, more preferably 20 to 100°C.

To achieve transparency and mechanical properties, it is preferable to produce a sheet or film by passing the sheet or film-like resin extruded from the T-die through the gap between at least one pair of pressure rolls while applying pressure. It is even more preferable that at least one of the pair of pressure rolls is a metal elastic roll. Furthermore, from the viewpoints of suppressing the inclusion of foreign matter and fisheyes, as well as transparency, it is preferable that a screen mesh be included in the film molding machine. While there are no particular restrictions on the mesh count of the screen mesh, from the viewpoints of suppressing the inclusion of foreign matter and fisheyes, it is preferably 40 mesh or more, more preferably 60 mesh or more, and even more preferably 70 mesh or more. From the viewpoint of achieving transparency, it is preferably 300 mesh or less, more preferably 250 mesh or less, and even more preferably 150 mesh or less. Therefore, the mesh count of the screen mesh is preferably 40 to 300 mesh, more preferably 60 to 250 mesh, and even more preferably 70 to 150 mesh. The transparency can be further enhanced by suppressing the expansion of dispersed particles in the resin due to shear when the molten resin passes through the screen mesh. In this specification, mesh count refers to the number of holes per inch (25.4 mm) as specified in ASTM E11.

The upper limit of the thickness of the sheet or film is preferably 800 μm, more preferably 600 μm, even more preferably 400 μm, and particularly preferably 300 μm. The lower limit of the thickness of the sheet or film is preferably 10 μm, more preferably 30 μm, even more preferably 50 μm, and particularly preferably 80 μm.

[Laminate]
The present invention also includes a laminate having a layer (A) made of the thermoplastic polymer composition, a layer (B) made of a cured resin, and a layer (C) made of a pressure-sensitive adhesive, which are laminated in the order of (B)-(A)-(C).

[Layer (A) made of thermoplastic polymer composition]
(Contents of Block Copolymer (I), Acrylic Resin (II), Acrylic Resin (III) and Softener (IV))
The thermoplastic polymer composition contained in the layer (A) made of a thermoplastic polymer composition in the laminate of the present invention (hereinafter, may be referred to as the thermoplastic polymer composition layer (A)) is a thermoplastic polymer composition containing the block copolymer (I), the acrylic resin (II), the acrylic resin (III), and the softener (IV) represented by the following formulas (d), (e), and (f):
0.1≦W(II)/W(I)≦2.4 (d)
0.001≦W(III)/(W(I)+W(II))≦0.04 (e)
0≦W(IV)/(W(I)+W(II)+W(III)+W(IV))≦0.5 (f)
[In the formula, W(I), W(II), W(III), and W(IV) represent the contents (by mass) of the block copolymer (I), the acrylic resin (II), the acrylic resin (III), and the softener (IV) in the thermoplastic polymer composition, respectively.]
It contains in a proportion that satisfies the following.
The preferred ranges of the formulas (d) to (f) are the same as the preferred ranges of the formulas (a) to (c).

In one preferred embodiment of the laminate of the present invention, the layer (A) is made of a thermoplastic resin composition having a film thickness variation coefficient of 5% or less, as measured in accordance with JIS K 7130:1999 using a film formed to a thickness of 150 μm using an extruder, and having tear strengths of 400 N/cm or more in both the MD and TD directions, as measured at room temperature using an unnotched angle-shaped test piece in accordance with JIS K 6252-1:2015.
Furthermore, the laminate of the present invention preferably has a tear strength in both the MD direction and the TD direction of 400 N/cm or more at room temperature, as measured using an unnotched angle-shaped test piece according to JIS K 6252-1:2015.

[Layer (B) made of cured resin]
The layer (B) made of a cured resin in the laminate of the present invention (hereinafter sometimes referred to as the cured resin layer (B)) can be made of any cured resin without any particular restrictions, and any curing method can be used. In view of adhesion to the thermoplastic polymer composition layer (A), the cured resin layer (B) is preferably one containing a urethane (meth)acrylate resin. In view of antifouling properties, the urethane (meth)acrylate resin preferably contains a fluorine atom and a silicon atom.

[Layer (C) made of adhesive]
The layer (C) comprising a pressure-sensitive adhesive in the laminate of the present invention (hereinafter, may be referred to as pressure-sensitive adhesive layer (C)) can be one or more pressure-sensitive adhesives selected from the group consisting of pressure-sensitive adhesives such as synthetic rubber-based pressure-sensitive adhesives, acrylic-based pressure-sensitive adhesives, silicone pressure-sensitive adhesives, urethane pressure-sensitive adhesives, etc., without any particular limitation. In view of the adhesiveness to the thermoplastic polymer composition layer (A), the pressure-sensitive adhesive layer (C) is preferably one containing an acrylic pressure-sensitive adhesive or a synthetic rubber pressure-sensitive adhesive.

[Acrylic adhesive]
The pressure-sensitive adhesive layer (C) preferably contains, as an acrylic pressure-sensitive adhesive, an acrylic block copolymer (V) having at least one polymer block R composed of structural units derived from a methacrylic acid ester and at least one polymer block S composed of structural units derived from an acrylic acid ester. The content of the acrylic block copolymer (V) in the pressure-sensitive adhesive layer (C) is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

The acrylic pressure-sensitive adhesive may contain an acrylic polymer other than the acrylic block copolymer (V). Examples of acrylic polymers other than the acrylic block copolymer (V) include (meth)acrylic acid ester homopolymers such as polymethyl methacrylate, random copolymers of (meth)acrylic acid esters, ethylene-acrylic acid ester copolymers, ethylene-methacrylic acid copolymers (EMAA resins), AS resins, ABS resins, AES resins, AAS resins, ACS resins, MBS resins, and styrene-methyl methacrylate copolymers, but are not limited to these and include polymers obtained using (meth)acrylic acid or (meth)acrylic acid esters as at least one of the raw materials.

The weight-average molecular weight (Mw) of the acrylic block copolymer (V) is typically preferably 30,000 to 300,000, and more preferably 45,000 to 150,000. If the Mw of the acrylic block copolymer (V) is 30,000 or more, the melt viscosity of the acrylic block copolymer (V) does not become extremely small, improving take-up by rolls and facilitating coextrusion molding. If the Mw of the acrylic block copolymer (V) is 300,000 or less, the melt viscosity of the acrylic block copolymer (V) does not become extremely large, reducing the risk of the surface of the molded article obtained by coextrusion molding becoming rough. Furthermore, from the viewpoint of improving adhesive properties such as cohesive strength of the pressure-sensitive adhesive layer (C), the ratio of Mw to Mn (Mw/Mn) of the acrylic block copolymer (V) is preferably 1.0 to 2.0, more preferably 1.0 to 1.8, even more preferably 1.0 to 1.5, and particularly preferably 1.0 to 1.3.

Examples of methacrylate esters that are constituent units of polymer block R include methacrylate esters that do not have functional groups, such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, lauryl methacrylate, tridecyl methacrylate, stearyl methacrylate, isobornyl methacrylate, phenyl methacrylate, and benzyl methacrylate; and methacrylate esters that have functional groups, such as methoxyethyl methacrylate, ethoxyethyl methacrylate, diethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, 2-aminoethyl methacrylate, glycidyl methacrylate, and tetrahydrofurfuryl methacrylate.

Among these, from the viewpoint of improving the transparency, heat resistance, and durability of the acrylic pressure-sensitive adhesive, methacrylic acid esters having no functional group are preferred, and methyl methacrylate, ethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, and phenyl methacrylate are more preferred, with methyl methacrylate being even more preferred. The polymer block R may be composed of one or more of these methacrylic acid esters.
From the viewpoint of enhancing durability, the acrylic block copolymer (V) preferably contains two or more polymer blocks R. In this case, the polymer blocks R may be the same or different.

The weight-average molecular weight (Mw) of polymer block R is not particularly limited, but is typically preferably 1,000 to 50,000, and more preferably 4,000 to 20,000. When the weight-average molecular weight (Mw) of polymer block R is 1,000 or more, there is little risk of the resulting acrylic block copolymer (V) or an acrylic pressure-sensitive adhesive containing the acrylic block copolymer (V) having insufficient cohesive strength. Furthermore, when the weight-average molecular weight (Mw) of polymer block R is 50,000 or less, the melt viscosity of the resulting acrylic pressure-sensitive adhesive does not become too high, resulting in good productivity and coextrusion moldability of the acrylic block copolymer (V). The proportion of methacrylic acid ester units contained in polymer block R is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, of the polymer block R.

The content of polymer block R in acrylic block copolymer (V) is preferably 10 to 50% by mass. In order to provide excellent adhesive properties and enable the supply of acrylic block copolymer (V) or an acrylic pressure-sensitive adhesive containing acrylic block copolymer (V) in a form that is easy to handle (e.g., pellets), the content of polymer block R is more preferably 10 to 45% by mass, and even more preferably 15 to 40% by mass.

Examples of acrylic acid ester units constituting the polymer block S include acrylic acid esters without functional groups, such as n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, isobornyl acrylate, lauryl acrylate, phenyl acrylate, and benzyl acrylate; and acrylic acid esters with functional groups, such as methoxyethyl acrylate, ethoxyethyl acrylate, diethylaminoethyl acrylate, 2-hydroxyethyl acrylate, 2-aminoethyl acrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate, and phenoxyethyl acrylate. Among these, acrylic acid esters without functional groups are preferred from the viewpoint of improving the transparency, flexibility, cold resistance, and low-temperature properties of the resulting acrylic pressure-sensitive adhesive containing the acrylic block copolymer (V). These may be used alone or in combination of two or more.

When the acrylic block copolymer (V) contains two or more polymer blocks S, the structures of the polymer blocks S may be the same or different. Furthermore, the proportion of acrylic acid ester units contained in the polymer block S is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, of the polymer block S.

Polymer block R and polymer block S may contain components of each other to the extent that the effects of the present invention are not impaired. When these components are contained, the structure may be a random structure, or a gradient structure (tapered structure) in which the copolymerization ratio gradually changes at one or more boundaries between polymer block R and polymer block S. Other monomers may also be contained as necessary. Examples of such other monomers include vinyl compounds having a carboxyl group such as (meth)acrylic acid, crotonic acid, maleic acid, maleic anhydride, and fumaric acid; vinyl monomers having functional groups such as (meth)acrylamide, (meth)acrylonitrile, vinyl acetate, vinyl chloride, and vinylidene chloride; aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, and m-methylstyrene; conjugated diene compounds such as butadiene and isoprene; olefin compounds such as ethylene, propylene, isobutene, and octene; and lactone monomers such as ε-caprolactone and valerolactone. When these are contained, their amount is usually preferably 40% by mass or less, and more preferably 20% by mass or less, based on the total mass of the monomers used in each polymer block.

In addition to the polymer block R and polymer block S, the acrylic block copolymer (V) may contain other polymer blocks as needed. Examples of such other polymer blocks include polymer or copolymer blocks made of styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, acrylonitrile, methacrylonitrile, ethylene, propylene, isobutene, butadiene, isoprene, octene, vinyl acetate, maleic anhydride, vinyl chloride, vinylidene chloride, etc.; polymer blocks made of polyethylene terephthalate, polylactic acid, polyurethane, and polydimethylsiloxane. The above polymer blocks also include hydrogenated polymer blocks containing conjugated diene compounds such as butadiene and isoprene.

The method for producing the acrylic block copolymer (V) is not particularly limited, and a method based on a known technique can be employed.
Alternatively, commercially available products such as the Kuraly (registered trademark) series manufactured by Kuraray Co., Ltd. may also be used.

The acrylic adhesive may further contain one or more additives, such as tackifier resins, softeners, plasticizers, heat stabilizers, light stabilizers, antistatic agents, flame retardants, foaming agents, colorants, dyes, refractive index adjusters, fillers, and curing agents, to the extent that the effects of the present invention are not impaired.

The above-mentioned tackifying resins may, from the viewpoint of easy adjustment of tack, adhesive strength, and holding power, be, for example, rosins such as gum rosin, tall oil rosin, and wood rosin; modified rosins such as hydrogenated rosin, disproportionated rosin, and polymerized rosin; rosin-based resins such as rosin esters of these rosins and modified rosins, such as glycerin esters and pentaerythritol esters; terpene-based resins such as terpene resins based on α-pinene, β-pinene, and dipentene, aromatic modified terpene resins, hydrogenated terpene resins, and terpene phenolic resins; (hydrogenated) aliphatic (C5) petroleum resins, (hydrogenated Examples of suitable tackifier resins include (hydrogenated) petroleum resins such as aromatic (C9) petroleum resins, (hydrogenated) copolymer (C5/C9) petroleum resins, (hydrogenated) dicyclopentadiene petroleum resins, and alicyclic saturated hydrocarbon resins; styrene polymers such as poly-α-methylstyrene, α-methylstyrene/styrene copolymers, styrene monomer/aliphatic monomer copolymers, styrene monomer/α-methylstyrene/aliphatic monomer copolymers, styrene monomer copolymers, and styrene monomer/aromatic monomer copolymers; and synthetic resins such as coumarone-indene resins, phenolic resins, and xylene resins. Among the above tackifier resins, rosin resins, terpene resins, (hydrogenated) petroleum resins, and styrene resins are preferred due to their high adhesive strength. These may be used alone or in combination.

Furthermore, when a tackifier resin is contained, from the viewpoint of adhesive strength and durability, the content thereof is preferably 1 to 100 parts by mass, more preferably 3 to 70 parts by mass, even more preferably 5 to 50 parts by mass, particularly preferably 5 to 40 parts by mass, and most preferably 5 to 35 parts by mass, per 100 parts by mass of the acrylic block copolymer (V).

Commercially available styrene-based resins include SX100 (manufactured by Yasuhara Chemical Co., Ltd.), FTR6000 series, and FTR7000 series (manufactured by Mitsui Chemicals, Inc.).

Softeners or plasticizers include, for example, fatty acid esters such as dibutyl phthalate, di-n-octyl phthalate, bis-2-ethylhexyl phthalate, di-n-decyl phthalate, and diisodecyl phthalate; adipate esters such as bis-2-ethylhexyl adipate and di-n-octyl adipate; sebacate esters such as bis-2-ethylhexyl sebacate and di-n-butyl sebacate; and azelaate esters such as bis-2-ethylhexyl azelate; chlorinated para- Examples of suitable oils include paraffins such as fin; glycols such as polypropylene glycol; epoxy-based polymer plasticizers such as epoxidized soybean oil and epoxidized linseed oil; phosphate esters such as trioctyl phosphate and triphenyl phosphate; phosphites such as triphenyl phosphite; acrylic oligomers such as poly(n-butyl(meth)acrylate) and poly(2-ethylhexyl(meth)acrylate; polybutene; polyisobutylene; polyisoprene; process oil; and naphthenic oil. These may be used alone or in combination of two or more.

Fillers include, for example, inorganic fibers such as glass fiber and carbon fiber; organic fibers; and inorganic fillers such as calcium carbonate, talc, carbon black, titanium oxide, silica, clay, barium sulfate, and magnesium carbonate.

Curing agents include photocuring agents such as UV curing agents and heat curing agents, such as benzoins such as benzoin, α-methylolbenzoin, and α-t-butylbenzoin; benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin-n-propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, α-methylolbenzoin methyl ether, α-methoxybenzoin methyl ether, and benzoin phenyl ether; benzophenone; anthraquinones such as 9,10-anthraquinone and 2-ethyl-9,10-anthraquinone; benzyl; acetophenones such as 2,2-dimethoxy-1,2-diphenylethan-1-one (2,2-dimethoxy-2-phenylacetophenone); and diacetyl. These curing agents may be used alone or in combination. By including a curing agent, the adhesive can be suitably used as a curable adhesive, such as a UV-curable hot-melt adhesive.

The pressure-sensitive adhesive layer (C) contains the acrylic pressure-sensitive adhesive in an amount of preferably 50% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably substantially 100 parts by mass. The pressure-sensitive adhesive layer (C) may further contain other polymers in addition to the acrylic pressure-sensitive adhesive.
Examples of the other polymers include olefin polymers such as polyethylene, ethylene-vinyl acetate copolymer (EVA resin), maleic anhydride-modified polyethylene, polypropylene, maleic anhydride-modified polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene; ethylene ionomers; styrene resins such as polystyrene, styrene-maleic anhydride copolymer, and high-impact polystyrene; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyamides such as nylon 6, nylon 66, and polyamide elastomers; polycarbonate; polyvinyl chloride; polyvinylidene chloride; polyvinyl alcohol; ethylene-vinyl alcohol copolymer; polyacetal; polyvinylidene fluoride; polyurethane; modified polyphenylene ether; polyphenylene sulfide; silicone rubber-modified polymers; acrylic rubber; silicone rubber; and olefin rubbers such as isoprene rubber (IR), ethylene-propylene rubber (EPR), and ethylene-propylene-diene rubber (EPDM).

The method for producing the acrylic adhesive is not particularly limited. For example, it can be produced by mixing the components using a known mixing or kneading device such as a kneader-ruder, extruder, mixing roll, or Banbury mixer, typically at 100 to 250°C. The resulting acrylic adhesive can then be heated and melted for use in forming the adhesive layer (C).

[Synthetic rubber adhesive]
The pressure-sensitive adhesive layer (C) preferably contains, as a synthetic rubber-based pressure-sensitive adhesive, an aromatic vinyl block copolymer (VI) containing a polymer block mainly composed of structural units derived from an aromatic vinyl monomer and a hydrogenated or non-hydrogenated polymer block mainly composed of structural units derived from a conjugated diene monomer. Here, "mainly composed" means that the polymer block contains 50% by mass or more of structural units derived from an aromatic vinyl monomer, based on the total mass of the polymer blocks, and that the hydrogenated or non-hydrogenated polymer blocks contain 50% by mass or more of structural units derived from a conjugated diene monomer. The content of the block copolymer (VI) in the pressure-sensitive adhesive layer (C) is preferably 10% by mass or more.

Aromatic vinyl monomers that constitute polymer blocks primarily composed of structural units derived from aromatic vinyl monomers include, for example, styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene (o,p-dimethylstyrene), vinylnaphthalene, and vinylanthracene, with styrene or α-methylstyrene being preferred. Polymer blocks primarily composed of structural units derived from aromatic vinyl monomers can be formed from one or more of these aromatic vinyl monomers.

Conjugated diene monomers that constitute hydrogenated or non-hydrogenated polymer blocks primarily composed of structural units derived from conjugated diene monomers include, for example, 1,3-butadiene (butadiene), isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene, with isoprene, butadiene, or mixtures of these being preferred. Hydrogenated or non-hydrogenated polymer blocks primarily composed of structural units derived from conjugated diene monomers can be formed from one or more of these conjugated diene monomers.

In the hydrogenated or non-hydrogenated polymer block in block copolymer (VI) that is primarily composed of structural units derived from a conjugated diene monomer, it is preferred that 70% or more of the carbon-carbon double bonds derived from the conjugated diene are hydrogenated, more preferably 80% or more, and particularly preferably 95% or more.

By selecting a hydrogenated block copolymer with a hydrogenation rate of 70% or more, it is possible to suppress deterioration of the base polymer during extrusion molding, improve the heat resistance of the resulting adhesive article, and obtain an adhesive article with the desired adhesive performance.

The hydrogenation rate of the carbon-carbon double bonds derived from the conjugated diene in the polymer block of block copolymer (VI) primarily composed of structural units derived from the conjugated diene monomer can be determined, for example, by measuring the iodine value, using an infrared spectrophotometer, or a nuclear magnetic resonance spectrometer.

In block copolymer (VI), the content of polymer blocks primarily composed of structural units derived from aromatic vinyl monomers is preferably in the range of 3% by mass to 70% by mass, and more preferably 10% by mass to 65% by mass. If the polymer block content is less than 3% by mass, the cohesive strength of the adhesive composition using the hydrogenated block copolymer as the base polymer will be poor, and extrusion moldability will be reduced, making it difficult to form a good adhesive layer. On the other hand, if the polymer block content exceeds 70% by mass, the adhesive performance of the resulting adhesive layer will be insufficient.

The number average molecular weight of the block copolymer (VI) is in the range of 50,000 or more and 200,000 or less. If the number average molecular weight is less than 50,000, it will be difficult to obtain an adhesive article with sufficient adhesive performance. On the other hand, if the number average molecular weight exceeds 200,000, even if the amounts of polyethylene and tackifier resin added are adjusted, the melt viscosity of the adhesive composition will be high, making extrusion molding difficult. A preferred number average molecular weight is in the range of 50,000 or more and 180,000 or less.

In the block copolymer (VI), one or more polymer blocks primarily composed of structural units derived from an aromatic vinyl monomer are bonded to one or more hydrogenated or non-hydrogenated polymer blocks primarily composed of structural units derived from a conjugated diene monomer to form the block copolymer. The bonding mode of the polymer blocks is not limited, and may be linear, branched, or any combination thereof.

Furthermore, hydrogenated or non-hydrogenated polymer blocks primarily composed of structural units derived from conjugated diene monomers may have functional groups or substituents such as carboxyl groups, hydroxyl groups, acid anhydride groups, amino groups, epoxy groups, halogen atoms, etc. in the main chain or in side chains, including terminals, within the scope of the present invention.

There are no particular limitations on the method for obtaining block copolymer (VI). For example, it can be obtained by sequentially polymerizing an aromatic vinyl monomer and a conjugated diene monomer in an inert organic solvent such as hexane or cyclohexane using an alkyllithium compound as an initiator, and then hydrogenating the resulting block copolymer by a known method. Aromatic vinyl block copolymers are also commercially available. Block copolymer (VI) may be used alone or in combination of two or more types.

[Tackifying resin]
The synthetic rubber-based adhesive may contain a tackifying resin (VII).
Examples of tackifying resins include, from the viewpoint of facilitating adjustment of tack, adhesive strength, and holding power, rosins such as gum rosin, tall oil rosin, and wood rosin; modified rosins such as hydrogenated rosin, disproportionated rosin, and polymerized rosin; rosin-based resins such as rosin esters of these rosins and modified rosins, such as glycerin esters and pentaerythritol esters; terpene-based resins such as terpene resins based on α-pinene, β-pinene, dipentene, etc., aromatic modified terpene resins, hydrogenated terpene resins, and terpene phenolic resins; (hydrogenated) aliphatic (C5) petroleum resins; (hydrogenated) Examples of (hydrogenated) petroleum resins include aromatic (C9) petroleum resins, (hydrogenated) copolymer (C5/C9) petroleum resins, (hydrogenated) dicyclopentadiene petroleum resins, and alicyclic saturated hydrocarbon resins; styrene polymers such as poly-α-methylstyrene, α-methylstyrene/styrene copolymers, styrene monomer/aliphatic monomer copolymers, styrene monomer/α-methylstyrene/aliphatic monomer copolymers, styrene monomer copolymers, and styrene monomer/aromatic monomer copolymers; and synthetic resins such as coumarone-indene resins, phenolic resins, and xylene resins. Among the above tackifying resins, rosin resins, terpene resins, (hydrogenated) petroleum resins, and styrene resins are preferred in terms of exhibiting high adhesive strength. These may be used alone or in combination of two or more.

Commercially available styrene-based resins include SX100 (manufactured by Yasuhara Chemical Co., Ltd.), FTR6000 series, and FTR8000 series (manufactured by Mitsui Chemicals, Inc.).

Commercially available petroleum resins such as the Imarv series (Idemitsu Kosan Co., Ltd.) and the Alcon series (Arakawa Chemical Industries Co., Ltd.) can be used.

[Softener]
The synthetic rubber-based adhesive may contain a softener (VIII).
Examples of softeners that can be used include known softeners such as hydrocarbon oils such as paraffinic, naphthenic, and aromatic oils; vegetable oils such as peanut oil and rosin; phosphate esters; low-molecular-weight polyethylene glycol; liquid paraffin; and hydrocarbon synthetic oils such as low-molecular-weight polyethylene, ethylene-α-olefin copolymer oligomer, liquid polybutene, liquid polyisoprene or its hydrogenated products, and liquid polybutadiene or its hydrogenated products. These may be used alone or in combination of two or more. Among these, paraffinic hydrocarbon oils and hydrocarbon synthetic oils such as ethylene-α-olefin copolymer oligomer are preferred. The kinematic viscosity of the softener (IV) at 40°C is preferably 50 to 1,000 mm ² /s, more preferably 50 to 800 mm ² /s, and even more preferably 80 to 600 mm ² /s, from the viewpoints of moldability and ease of application.

The synthetic rubber-based adhesive contained in the adhesive layer (C) is a compound obtained by reacting the block copolymer (VI), the tackifier resin (VII), and the softener (VIII) with each other in the following formulas (i) and (j):
0.1≦W(VII)/W(VI)≦3.0 (i)
0.0≦W(VIII)/(W(VI)+W(VII))≦1.0 (j)
[wherein W(VI), W(VII), and W(VIII) represent the contents (by mass) of the block copolymer (VI), tackifier resin (VII), and softener (VIII), respectively, in the synthetic rubber-based pressure-sensitive adhesive.]
It is preferable that the content satisfies the following ratio.

As with the acrylic adhesive described above, the synthetic rubber adhesive may further contain one or more additives such as plasticizers, heat stabilizers, light stabilizers, antistatic agents, flame retardants, foaming agents, colorants, dyes, refractive index adjusters, fillers, and curing agents, as long as the effects of the present invention are not impaired.

The pressure-sensitive adhesive layer (C) preferably contains 50% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably substantially 100 parts by mass of the synthetic rubber-based pressure-sensitive adhesive. The pressure-sensitive adhesive layer (C) may further contain other polymers in addition to the synthetic rubber-based pressure-sensitive adhesive.
Examples of the other polymers include olefin polymers such as polyethylene, ethylene-vinyl acetate copolymer (EVA resin), maleic anhydride-modified polyethylene, polypropylene, maleic anhydride-modified polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene; ethylene ionomers; styrene resins such as polystyrene, styrene-maleic anhydride copolymer, and high-impact polystyrene; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyamides such as nylon 6, nylon 66, and polyamide elastomers; polycarbonate; polyvinyl chloride; polyvinylidene chloride; polyvinyl alcohol; ethylene-vinyl alcohol copolymer; polyacetal; polyvinylidene fluoride; polyurethane; modified polyphenylene ether; polyphenylene sulfide; silicone rubber-modified polymers; acrylic rubber; silicone rubber; and olefin rubbers such as isoprene rubber (IR), ethylene-propylene rubber (EPR), and ethylene-propylene-diene rubber (EPDM).

The synthetic rubber-based adhesive can be produced by any method without particular limitations. For example, it can be produced by mixing the components using a known mixing or kneading device such as a kneader-ruder, extruder, mixing roll, or Banbury mixer, typically at 100 to 250°C. The resulting synthetic rubber-based adhesive can then be heated and melted for use in forming the adhesive layer (C).

(Thickness ratio of thermoplastic polymer composition layer (A), cured resin layer (B), and pressure-sensitive adhesive layer (C))
The laminate of the present invention has thicknesses of the thermoplastic polymer composition layer (A), the cured resin layer (B), and the pressure-sensitive adhesive layer (C) that satisfy the following formulas (g) and (h):
0.02≦T(B)/T(A)≦0.30 (g)
0.04≦T(C)/(T(A)+T(B))≦0.50 (h)
[In the formula, T(A), T(B), and T(C) respectively represent the thicknesses (mm) of the thermoplastic polymer composition layer (A), the cured resin layer (B), and the pressure-sensitive adhesive layer (C) constituting the laminate.]
In one preferred embodiment, the above condition is satisfied.

In formula (g), when the value of "T(B)/T(A)", i.e., the ratio of the thickness of the cured resin layer (B) to the thickness of the thermoplastic polymer composition layer (A), is 0.02 or more, resistance to scratches and impacts is easily maintained. Furthermore, when it is 0.30 or less, the layer made of the cured resin does not become too thick, and is less likely to break when bent or stretched. The value of "T(B)/T(A)" is preferably 0.02 to 0.30, more preferably 0.03 to 0.28, even more preferably 0.04 to 0.24, and particularly preferably 0.05 to 0.20.
Furthermore, in formula (h), when the value of "T(C)/(T(A)+T(B))", i.e., the ratio of the thickness of the pressure-sensitive adhesive layer (C) to the total thickness of the thermoplastic polymer composition layer (A) and the cured resin layer (B), is 0.04 or more, the laminate is likely to exhibit sufficient adhesive strength. Furthermore, when it is 0.50 or less, adhesive residue is less likely to be left when the laminate is peeled off from the adherend. The value of "T(C)/(T(A)+T(B))" is preferably 0.04 to 0.50, more preferably 0.06 to 0.45, and even more preferably 0.08 to 0.40.

In the laminate of the present invention, the thickness of the thermoplastic polymer composition layer (A) is preferably 100 to 300 μm, more preferably 110 to 250 μm, and even more preferably 120 to 220 μm. When the thickness of the thermoplastic polymer composition layer (A) is 300 μm or less, the laminate does not become too hard and is easy to handle. On the other hand, when the thickness is 100 μm or more, the strength of the laminate can be maintained, and when used as a protective film, sufficient protective performance tends to be exhibited.
The form of the laminate of the present invention before application to various uses is not particularly limited, but examples thereof include a form in which sheets are stacked together, and a form in which the laminate is wound into a roll.

The film thickness variation (difference between the maximum and minimum thickness values) of the thermoplastic polymer composition layer (A) is preferably 25 μm or less, more preferably 20 μm or less, even more preferably 17 μm or less, and even more preferably 15 μm or less.
The thickness variation coefficient, which is expressed as the ratio of thickness variation to the average thickness (actually measured value) of the thermoplastic polymer composition layer (A), is preferably 5% or less, more preferably 4% or less, more preferably 3% or less, and even more preferably 2% or less. The thickness variation coefficient can be calculated using the following formula:
(Film thickness variation coefficient) [%] = (Film thickness variation) / (Average film thickness) × 100
It can be found by:

There is no particular limit to the number of layers constituting the laminate of the present invention, and as long as they are laminated in the order of (B)-(A)-(C), another layer may be laminated between each of the layers. For example, another layer such as a release layer may be laminated on the surface of the pressure-sensitive adhesive layer (C) opposite to the surface that comes into contact with the thermoplastic polymer composition layer (A), or another layer such as a printed layer may be laminated on the surface that comes into contact with the thermoplastic polymer composition layer (A).

(Properties of the laminate)
In the laminate of the present invention, the 180° peel strength at a peel rate of 300 mm/min 24 hours after lamination to an automotive steel plate (product name: SPCC-SD, manufactured by Nippon Test Panel Co., Ltd.), measured at room temperature (23°C) in accordance with JIS Z 0237:2022, is preferably 10 to 25 N/25 mm, more preferably 15 to 25 N/25 mm, and even more preferably 18 to 25 N/25 mm.
For example, when the laminate of the present invention is used as a protective film, if the peel strength to an automotive steel plate (adherend) is small, the laminate may not adhere to the adherend with sufficient strength during attachment to the automotive steel plate, and may peel off easily. If the peel strength is too high, the peeling operation becomes difficult, and if an attempt is made to peel it off forcefully, the adherend itself may be deformed.

(Method for manufacturing laminate)
The method for producing the laminate of the present invention is not particularly limited, and any method can be used, such as coextrusion molding or solution coating of the thermoplastic polymer composition layer (A). From the viewpoint of cost, the method for producing the laminate is preferably a coextrusion molding method using a feed block or a multi-manifold die, and further using a film-forming device such as a T-die extruder or an inflation molding machine. Furthermore, from the viewpoint of transparency when formed into a laminate, solution coating of the thermoplastic polymer composition layer (A) can also be preferably used. A production method including laminating the thermoplastic polymer composition layer (A) and the pressure-sensitive adhesive layer (C) by melt coextrusion is also a preferred embodiment.

[Application]
The laminate of the present invention can be used for various applications, such as pressure-sensitive adhesive tapes and films for surface protection, masking, bundling, packaging, office use, labeling, decoration/display, bonding, dicing tape, sealing, corrosion prevention/waterproofing, medical/hygienic use, shatterproofing of glass, electrical insulation, holding and fixing electronic devices, semiconductor manufacturing, optical display films, pressure-sensitive adhesive optical films, electromagnetic wave shielding, and sealing materials for electric/electronic components.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.
The components used in the examples and comparative examples and their properties are shown in Tables 1 to 8 below.

The weight average molecular weight was determined by gel permeation chromatography (GPC) under the following conditions and expressed as a value converted into standard polystyrene:
Column: "TSKgel G4000HXL" (trade name) x 2, manufactured by Tosoh Corporation (column temperature: 40°C)
Mobile phase: tetrahydrofuran (flow rate: 1 ml/min)
Detector: differential refractometer (a multi-wavelength detector (detection wavelength: 254 nm) was further connected)
Standard substance: TSK standard polystyrene, manufactured by Tosoh Corporation. Sample concentration: 0.06% by mass.

The average degree of polymerization was measured at 20°C using an automatic dilution-type capillary viscometer (Ubbelohde type, capillary inner diameter = 0.5 mm) in chloroform as the solvent, and calculated as the PMMA-equivalent degree of polymerization.

[Block copolymer (I)]
Block copolymer (1) "Septon (registered trademark) Q-1250" (polymer block P: poly(α-methylstyrene), polymer block Q: polybutadiene (hydrogenation rate 90% or more), weight average molecular weight 78,700), manufactured by Kuraray Co., Ltd.
Block copolymer (2) "Septon (registered trademark) 4033" (polymer block P: polystyrene, polymer block Q: polybutadiene (hydrogenation rate 90% or more), weight average molecular weight 97,500), manufactured by Kuraray Co., Ltd.

[Acrylic resin (II)]
Acrylic resin (3) "PARAPET (registered trademark) G" (content of methyl methacrylate units = 85% by mass, content of vinyl monomer units copolymerizable with methyl methacrylate units = 15% by mass or less, average degree of polymerization = 1,000, MFR = 8 g/10 min (measured in accordance with JIS K 7210-1:2014, conditions: 230°C, 37.3 N), manufactured by Kuraray Co., Ltd.)
Acrylic resin (4) "PARAPET (registered trademark) GF" (methyl methacrylate unit content = 85% by mass, vinyl monomer unit content copolymerizable with methyl methacrylate units = 15% by mass or less, average polymerization degree = 1,000, MFR = 15 g/10 min (measured in accordance with JIS K 7210-1:2014, conditions: 230°C, 37.3 N), manufactured by Kuraray Co., Ltd.)
Acrylic resin (5) "PARAPET (registered trademark) GH-S" (methyl methacrylate unit content = 90% by mass, vinyl monomer unit content copolymerizable with methyl methacrylate units = 10% by mass or less, average polymerization degree = 1,200, MFR = 10 g/10 min (measured in accordance with JIS K 7210-1:2014, conditions: 230°C, 37.3 N), manufactured by Kuraray Co., Ltd.)
Acrylic resin (6) "PARAPET (registered trademark) LW" (content of methyl methacrylate units = 85% by mass, content of vinyl monomer units copolymerizable with methyl methacrylate units = 15% by mass or less, average degree of polymerization = 500, MFR = not measurable due to high fluidity (measured in accordance with JIS K 7210-1:2014, conditions: 230°C, 37.3N), manufactured by Kuraray Co., Ltd.)
Acrylic resin (7) "PARAPET (registered trademark) HR-G" (methyl methacrylate unit content = 95% by mass, vinyl monomer unit content copolymerizable with methyl methacrylate units = 5% by mass or less, average polymerization degree = 1,800, MFR = 0.5 g/10 min (measured in accordance with JIS K 7210-1:2014, conditions: 230°C, 37.3 N), manufactured by Kuraray Co., Ltd.)
Acrylic resin (8) "Metablen (registered trademark) P-570A" (content of methyl methacrylate units = 95% by mass, content of vinyl monomer units copolymerizable with methyl methacrylate units = 5% by mass or less, average degree of polymerization = 2,700, MFR = < 0.1 g/10 min (measured in accordance with JIS K 7210-1:2014, conditions: 230°C, 37.3 N), manufactured by Mitsubishi Chemical Corporation)

[Acrylic resin (III)]
Acrylic resin (9) "Metablen (registered trademark) P-551A" (content of methyl methacrylate units = 84% by mass, content of vinyl monomer units copolymerizable with methyl methacrylate units = 16% by mass or less, average degree of polymerization = 14,500, MFR = < 0.1 g/10 min (measured in accordance with JIS K 7210-1:2014, conditions: 230 °C, 37.3 N), manufactured by Mitsubishi Chemical Corporation)
Acrylic resin (10) "Metablen (registered trademark) P-550A" (content of methyl methacrylate units = 88% by mass, content of vinyl monomer units copolymerizable with methyl methacrylate units = 12% by mass or less, average degree of polymerization = 9,500, MFR = < 0.1 g/10 min (measured in accordance with JIS K 7210-1:2014, conditions: 230°C, 37.3 N), manufactured by Mitsubishi Chemical Corporation)
Acrylic resin (11) "Metablen (registered trademark) P-530A" (content of methyl methacrylate units = 80% by mass, content of vinyl monomer units copolymerizable with methyl methacrylate units = 20% by mass or less, average degree of polymerization = 31,000, MFR = < 0.1 g/10 min (measured in accordance with JIS K 7210-1:2014, conditions: 230 °C, 37.3 N), manufactured by Mitsubishi Chemical Corporation)
Acrylic resin (12) "Metablen (registered trademark) P-531A" (content of methyl methacrylate units = 80% by mass, content of vinyl monomer units copolymerizable with methyl methacrylate units = 20% by mass or less, average degree of polymerization = 47,000, MFR = < 0.1 g/10 min (measured in accordance with JIS K 7210-1:2014, conditions: 230 °C, 37.3 N), manufactured by Mitsubishi Chemical Corporation)

[Softener (IV)]
Softener (13) "Diana Process Oil PW380" (kinematic viscosity (40°C) = 386.1 mm ² /s, paraffinic process oil, manufactured by Idemitsu Kosan Co., Ltd.)

[Laminate]
[Layer (B) made of cured resin]
(14) Two-component reactive curing resin containing urethane (meth)acrylate resin as the main material and containing fluorine and silicon atoms

[Layer (C) made of adhesive]
(15) An acrylic pressure-sensitive adhesive mainly composed of "CLARITY (registered trademark) LA3320" (an acrylic block copolymer with a polymer block R content of 18% by mass).

(16) LOCTITE DURO-TAK2835 (commercially available acrylic adhesive containing a crosslinking agent, manufactured by Henkel)

(17) A synthetic rubber adhesive primarily composed of "Septon (registered trademark) 2063" and containing FTR8100 (a styrene-based resin manufactured by Mitsubishi Chemical Corporation) as a tackifier.

<Examples 1 to 15 and Comparative Examples 1 to 7>
The components were premixed in a supermixer in the mass ratios shown in Table 1, then melt-kneaded using a twin-screw extruder and cut using an underwater cut method to obtain pellets of a thermoplastic polymer composition. The resulting pellets of the thermoplastic polymer composition were extruded using a single-screw extruder at a cylinder temperature of 240°C, a die head temperature of 245°C, and a cast roll temperature of 25°C, connected to a film molding machine, and a 150 μm thick, 30 cm wide film was produced using the T-die method. Using the thermoplastic polymer composition and the 150 μm thick film produced therefrom, physical properties were measured and evaluated as follows.
The evaluation results are shown in Tables 9-1 to 9-5 and Tables 10-1 to 10-2.

[Transparency]
Transparency was evaluated using the haze value of a 150 μm thick film measured using a turbidity/haze meter "HR-100" (manufactured by Murakami Color Research Laboratory Co., Ltd.) in accordance with JIS K 7136:2000. The lower the haze value, the better the transparency, with less than 2.0 being rated as ◯, 2.0 to 3.0 being △, and more than 3.0 being x.

[Film thickness variation]
A 150 μm thick film was collected in a length of 100 cm and divided into grids of 5 cm in the MD and 5 cm in the TD. The thickness of the center of each grid of 120 grids was measured in accordance with JIS K 7130:1999. The difference between the maximum and minimum measured thicknesses was taken as the film thickness variation. A film thickness variation of 15 μm or less was evaluated as ◯, more than 15 to 25 μm was evaluated as △, and more than 25 μm was evaluated as ×.
The coefficient of variation in film thickness was calculated using the following formula, and a coefficient of variation in film thickness of 5% or less was marked as ◯, and a coefficient of variation in film thickness of more than 5% was marked as x.
(Film thickness variation coefficient) [%] = (Film thickness variation) / (Average film thickness) × 100

[Melt tension]
The pellet-shaped thermoplastic polymer composition was extruded at an extrusion temperature of 230°C through a capillary having a diameter of 1 mm and a length of 10 mm at a piston speed of 5 mm/min using a melt tension measuring device of a capillary rheometer, and the strand was taken up, and the tension at which the strand broke was measured to evaluate the melt tension. A tension of 30 kPa or more was rated as ◯, a tension of 20 kPa or more but less than 30 kPa as △, and a tension of less than 20 kPa as ×.

[Spreadability]
The pellet-shaped thermoplastic polymer composition was extruded at an extrusion temperature of 230°C through a capillary having a diameter of 1 mm and a length of 10 mm at a piston speed of 5 mm/min using a melt tension measuring device of a capillary rheometer, and the strand was taken up to measure the breaking speed of the strand to evaluate extensibility. Breaking speeds of 40 m/min or more were rated as ◯, those of 35 m/min or more but less than 40 m/min as △, and those less than 35 m/min as ×.

[Tear strength (MD direction, TD direction)]
A 150 μm thick film was punched into an unnotched angle-shaped test piece according to JIS K 6252-1:2015, and the tear strength in the MD direction at room temperature was measured. The tear strength in the TD direction was also measured. Tear strengths of 400 N/cm or more were evaluated as ◯, those of 300 N/cm or more but less than 400 N/cm as △, and those of less than 300 N/cm as ×.

Tables 9-1 to 9-5 show that the 150 μm thick films formed using the thermoplastic polymer compositions of Examples 1 to 15 exhibited good transparency, high formability (film thickness stability), and low anisotropy. On the other hand, as shown in Table 10-1, Comparative Example 1, in which block copolymer (2) in which polymer block P was composed of polystyrene was used as block copolymer (I), resulted in significantly poor film transparency and formability. Comparative Example 2, in which acrylic resin (6) with a high average polymerization degree was used as acrylic resin (II), resulted in high film haze and poor transparency. Comparative Example 3, in which acrylic resin (9) with a high average polymerization degree was used as acrylic resin (III), resulted in low melt tension and poor formability. Comparative Example 4, in which acrylic resin (III) was not blended, showed significant film thickness fluctuation, making stable film formation impossible. Furthermore, as shown in Table 10-2, Comparative Example 5, in which excessive block copolymer (I) was used, showed significant film thickness fluctuation and made stable film formation impossible. In Comparative Example 6, in which an excess of acrylic resin (II) was used, the film had increased haze and decreased transparency. In Comparative Example 7, in which an excess of acrylic resin (III) was used, the film had increased haze, decreased transparency, and decreased extensibility.

<Examples 16 to 20 and Comparative Example 8>
In Examples 16 to 20 and Comparative Example 8, a three-layer laminate was prepared in which a 150 μm or 250 μm thick film made of the thermoplastic polymer composition of Example 2 was used as the thermoplastic polymer composition layer (A), and a cured resin layer (B) and a pressure-sensitive adhesive layer (C) were provided in the order (B)-(A)-(C).
In Examples 16 to 19, the laminate was prepared by solution coating both the cured resin layer (B) and the pressure-sensitive adhesive layer (C). In Example 20, the thermoplastic polymer composition layer (A) and the pressure-sensitive adhesive layer (C) were laminated by coextrusion molding (melt coextrusion), and the cured resin layer (B) was laminated by solution coating onto the thermoplastic resin layer (A) of the obtained laminate. In Comparative Example 8, the cured resin layer (B) was laminated onto the thermoplastic polymer composition layer (A) by solution coating, but the pressure-sensitive adhesive layer (C) was not laminated.
The physical properties of the produced laminate were measured and evaluated as follows. The evaluation results are shown in Table 11.

[Adhesive strength]
The laminate was subjected to 180° peel strength measurement at room temperature at a peel rate of 300 mm/min 24 hours after lamination to an automotive steel plate (product name: SPCC-SD, manufactured by Nippon Test Panel Co., Ltd.) in accordance with JIS Z 0237:2022 to evaluate adhesive strength. Adhesive strengths of 10 to 25 N/25 mm were evaluated as ◯, and adhesive strengths of less than 10 N/25 mm and greater than 25 N/25 mm were evaluated as ×.

[Glue residue]

The laminate was subjected to a 180° peel test at room temperature at a peel rate of 300 mm/min against an automotive steel plate (product name: SPCC-SD, manufactured by Nippon Test Panel Co., Ltd.) in accordance with JIS Z 0237:2022 24 hours after lamination, and the adhesive residue on the automotive steel plate at that time was visually evaluated. Those that did not leave adhesive residue were marked with ◯, and those that did leave adhesive residue were marked with ×.

Table 11 shows that the laminates of Examples 16 to 20 exhibit high adhesion to automotive steel sheets while leaving no adhesive residue. On the other hand, in Comparative Example 8, in which the adhesive layer (C) was not laminated, the tackiness of the thermoplastic polymer composition layer (A) was insufficient to provide adhesion to painted automotive steel sheets, and the laminate could not be used suitably as a protective film.

Claims (15)

a block copolymer (I) containing a polymer block P mainly composed of α-methylstyrene units and a hydrogenated or non-hydrogenated polymer block Q mainly composed of conjugated diene or isobutylene units, and having a weight average molecular weight of 30,000 to 200,000;
an acrylic resin (II) containing 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith, and having an average degree of polymerization of 400 to 2,000;
An acrylic resin (III) containing 50% by mass or more of methyl methacrylate units and 50% by mass or less of vinyl monomer units copolymerizable therewith, and having an average degree of polymerization of 6,000 to 40,000; and
Optionally, a softener (IV)
is expressed by the following formulas (a), (b) and (c):
0.1≦W(II)/W(I)≦2.4 (a)
0.001≦W(III)/(W(I)+W(II))≦0.04 (b)
0≦W(IV)/(W(I)+W(II)+W(III)+W(IV))≦0.5 (c)
[In the formula, W(I), W(II), W(III), and W(IV) represent the contents (by mass) of the block copolymer (I), the acrylic resin (II), the acrylic resin (III), and the softener (IV) in the thermoplastic polymer composition, respectively.]
A thermoplastic polymer composition comprising the above components in a proportion satisfying the above formula: The thermoplastic polymer composition according to claim 1, wherein the acrylic resin (II) has a melt flow rate of 5 to 25 g/10 min at 230°C and 37.3 N. The thermoplastic polymer composition according to claim 1, wherein the tension at which the strand breaks is 30 kPa or more when a strand is extruded at an extrusion temperature of 230°C from a capillary having a diameter of 1 mm and a length of 10 mm at a piston speed of 5 mm/min using a melt tension measuring device of a capillary rheometer and withdrawn. The thermoplastic polymer composition according to claim 1, wherein when a strand is extruded at an extrusion temperature of 230°C from a capillary having a diameter of 1 mm and a length of 10 mm at a piston speed of 5 mm/min using a melt tension measuring device of a capillary rheometer, the strand breaks at a speed of 40 m/min or more. Using a film formed to a thickness of 150 μm using an extruder,
The film thickness variation coefficient measured based on JIS K 7130:1999 is 5% or less.
The thermoplastic polymer composition according to claim 1, wherein the tear strength in the MD direction and the tear strength in the TD direction at room temperature measured using an unnotched angle-shaped test piece according to JIS K 6252-1:2015 are both 400 N/cm or more. A sheet or film made from the thermoplastic polymer composition described in any one of claims 1 to 5. A layer (A) comprising the thermoplastic polymer composition according to claim 1;
A layer (B) made of a cured resin, and a layer (C) made of an adhesive.
and a laminate in which these are laminated in the order of (B), (A), and (C). The thicknesses of the layer (A) made of the thermoplastic polymer composition, the layer (B) made of the cured resin, and the layer (C) made of the pressure-sensitive adhesive are each defined by the following formulas (g) and (h): 0.02≦T(B)/T(A)≦0.30(g).
0.04≦T(C)/(T(A)+T(B))≦0.50 (h)
[wherein T(A), T(B), and T(C) represent the thicknesses (mm) of the layer (A) made of the thermoplastic polymer composition, the layer (B) made of the cured resin, and the layer (C) made of the pressure-sensitive adhesive, respectively]
The laminate according to claim 7, wherein the ratio satisfies the following formula: The laminate described in claim 7, wherein the thickness of the layer (A) made of the thermoplastic polymer composition is 100 to 300 μm. The laminate according to claim 7, wherein the pressure-sensitive adhesive layer (C) contains an aromatic vinyl block copolymer (VI) containing a polymer block mainly composed of structural units derived from an aromatic vinyl monomer and a hydrogenated or non-hydrogenated polymer block mainly composed of structural units derived from a conjugated diene monomer. The layer (C) made of the pressure-sensitive adhesive is
Aromatic vinyl block copolymers (VI),
a tackifying resin (VII), and
Optionally, a softener (VIII)
into the following formulas (i) and (j):
0.1≦W(VII)/W(VI)≦3.0 (i)
0.0≦W(VIII)/(W(VI)+W(VII))≦1.0 (j)
[In the formula, W(VI), W(VII), and W(VIII) respectively represent the contents (by mass) of the block copolymer (VI), tackifier resin (VII), and softener (VIII) in the layer (C) composed of the pressure-sensitive adhesive composite.]
The laminate according to claim 10, wherein the content satisfies the following ratio. The laminate described in claim 7, wherein the layer (B) made of the cured resin contains a urethane (meth)acrylate resin. The laminate described in claim 12, wherein the urethane (meth)acrylate resin contains fluorine atoms and silicon atoms. The method for producing a laminate according to claim 7, comprising laminating a layer (A) made of the thermoplastic polymer composition and a layer (C) made of the pressure-sensitive adhesive by melt co-extrusion.
A protection film or protection sheet comprising the laminate according to any one of claims 8 to 13.