JP7293199B2 - Multilayer film and molded article provided with same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a decorative multilayer film and a decorative film used for vehicle exteriors and the like, and a molded article comprising them.

BACKGROUND ART Conventionally, vehicle exterior paints applied by a spray method have been used for vehicle exterior decoration. Such paints are used for the purpose of protecting the base material of the vehicle and providing the vehicle with an aesthetic appearance. In particular, in vehicle exterior members, the paint film may be partially chipped off due to impact applied to the paint film by splashing pebbles or snowmelt salt. Such damage is called chipping, and protection against chipping is called chipping resistance. When a pebble collides with a coating film lacking chipping resistance, the coating film is damaged, exposing the underlying layer and impairing the aesthetic appearance, which is a problem. Among vehicle exterior members, bumpers are particularly prone to chipping, and the coating film used therefor is required to have high chipping resistance.

By the way, polypropylene resin is widely used as a material for vehicle bumpers. The polypropylene-based resin has various advantages such as high impact resistance, low specific gravity, and low cost. On the other hand, a non-polar polypropylene resin tends to repel paint, and it is difficult to maintain high adhesion with the coating film resin. If the adhesiveness between the paint film and the resin forming the bumper is low, the chipping resistance tends to deteriorate.
On the other hand, Patent Document 1 discloses a primer composition having a predetermined composition, which can achieve both chipping resistance of the coating film and adhesion to polypropylene, which is a material for automobile bumpers. Further, in Patent Document 2, by forming a predetermined multilayer coating film, it is possible to obtain a multilayer coating film that is excellent in curability, chipping resistance, and finished appearance in a short time at a low temperature. A method is disclosed.

In recent years, a method has been proposed in which a decorative film is used to decorate the exterior of a vehicle or protect a base material, instead of using paint. The method using the decorative film eliminates the need for a long drying oven, which is essential in the coating process, and thus can save a large amount of energy. As a decoration method using such a film, in Patent Document 3, a film-like base material made of an olefin elastomer and an adhesive material layer applied to the adherend side of the base material for automotive exterior protection A film is disclosed.

Further, Patent Document 4 discloses a functional film composed of an adhesive material, a predetermined urethane resin, and a paint applied to the surface of the urethane resin layer. However, the step of applying the adhesive is required, which is complicated.

JP 2012-67197 A International Application Publication No. 2014/045657 JP 2004-115657 A Japanese Patent Application Laid-Open No. 2004-148508

However, the method using the coating composition described in Patent Document 1 and the method for forming a multilayer coating film described in Patent Document 2 require a large amount of energy to dry and cure the coating film, which poses a problem of increased environmental load. .

In addition, in the automotive exterior protective film described in Patent Document 3, the intervention of a primer layer is required in order to improve the adhesion between the substrate layer and the adhesive layer, which increases the number of steps and is complicated. is. In addition, the elastic modulus of the base material layer is relatively low, and the thickness of the base material is required to be 250 to 1000 μm, resulting in a problem of large weight. The method described in Patent Document 4 requires a step of applying an adhesive, which is complicated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a multilayer film and a decorative film having excellent chipping resistance, and a molded article comprising these films.

The present invention for achieving the above object is a multilayer film comprising a substrate layer and an adhesive material layer, wherein the adhesive material layer comprises
At least one block copolymer containing a polymer block (S) containing a structural unit derived from an aromatic vinyl compound and a polymer block (D) containing a structural unit derived from a conjugated diene compound or a hydrogenated product thereof A thermoplastic polymer composition containing 1 to 50 parts by mass of a polypropylene resin (B) with respect to 100 parts by mass of a thermoplastic elastomer (A) consisting of, at 11 Hz in the range of -50 to -20 ° C. A multilayer film comprising a composition having a loss tangent (tan δ) of 3×10 ⁻² or more.
Moreover, the structural unit derived from the conjugated diene compound constituting the polymer block (D) is preferably a structural unit derived from at least one selected from butadiene and isoprene.
Further, the substrate layer is preferably made of an amorphous resin, and more preferably, the amorphous resin is any one of (meth)acrylic resin, ABS resin, polycarbonate resin and polyester resin.
Another aspect of the present invention is a decorative film comprising the multilayer film described above, and a molded article comprising the multilayer film or the decorative film.

The multilayer film containing the adhesive material layer and the substrate layer of the present invention is excellent in chipping resistance. Therefore, it can be suitably used as a multilayer film for vehicle exteriors.

[Thermoplastic polymer composition]
The multilayer film of the present invention comprises a substrate layer and an adhesive layer comprising the following thermoplastic polymer composition,
The thermoplastic polymer composition comprises at least one block containing a polymer block (S) containing a structural unit derived from an aromatic vinyl compound and a polymer block (D) containing a structural unit derived from a conjugated diene compound. A thermoplastic polymer composition containing 1 to 50 parts by mass of (at least one) polypropylene resin (B) per 100 parts by mass of a thermoplastic elastomer (A) made of a copolymer or a hydrogenated product thereof. , a composition having a loss tangent (tan δ) at 11 Hz in the range of -50 to -20°C of 3×10 ^-2 or more. The above components (A) and (B) will be described in order below.

[Thermoplastic elastomer (A)]
The thermoplastic elastomer (A) contained in the thermoplastic polymer composition comprises a polymer block (S) containing a structural unit derived from an aromatic vinyl compound and a polymer block (D) containing a structural unit derived from a conjugated diene compound. ) is a block copolymer or a hydrogenated product thereof. The thermoplastic elastomer (A) imparts flexibility, good mechanical properties, moldability, etc. to the thermoplastic polymer composition, and plays a role of a matrix in the composition.

-Polymer Block (S) Containing Aromatic Vinyl Compound Unit-
Examples of aromatic vinyl compounds constituting the polymer block (S) include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene and 4-cyclohexylstyrene. , 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, and the like. A polymer block composed of an aromatic vinyl compound may consist of structural units derived from only one of these aromatic vinyl compounds, or may consist of structural units derived from two or more of these aromatic vinyl compounds. Among them, those composed of structural units derived from styrene, α-methylstyrene, and 4-methylstyrene are preferable.

The polymer block (S) containing a structural unit derived from an aromatic vinyl compound preferably contains 80% by mass or more of the structural unit derived from the aromatic vinyl compound, more preferably 90% by mass or more of the structural unit, still more preferably It is a polymer block containing 95% by mass or more of the structural unit. The polymer block (S) may have only structural units derived from an aromatic vinyl compound, but other copolymerizable monomers may be added together with the structural units as long as the effect of the present invention is not impaired. You may have a structural unit derived from. Other copolymerizable monomers include, for example, 1-butene, pentene, hexene, butadiene, isoprene and methyl vinyl ether. When it has a structural unit derived from another copolymerizable monomer, the ratio is relative to the total amount of the structural unit derived from the aromatic vinyl compound and the structural unit derived from the other copolymerizable monomer. , preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less.

-Polymer block (D) containing conjugated diene compound units-
Structural units derived from a conjugated diene compound constituting the polymer block (D) include butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. and the like. Among them, those derived from butadiene or isoprene are preferred.
The polymer block (D) containing structural units derived from a conjugated diene compound may consist of structural units derived from only one of these conjugated diene compounds, or from structural units derived from two or more of these conjugated diene compounds. It may be. In particular, it preferably consists of structural units derived from butadiene or isoprene, or structural units derived from butadiene and isoprene.

The polymer block (D) containing a structural unit derived from a conjugated diene compound preferably contains 80% by mass or more of the structural unit derived from the conjugated diene compound, more preferably 90% by mass or more of the structural unit, still more preferably the structure It is a polymer block containing 95% by mass or more of units. The polymer block (D) may have only a structural unit derived from a conjugated diene compound, but as long as it does not interfere with the present invention, the structural unit is derived from other copolymerizable monomers together with the structural unit. You may have a structural unit that Other copolymerizable monomers include, for example, styrene, α-methylstyrene, 4-methylstyrene and the like. When having structural units derived from other copolymerizable monomers, the ratio is, relative to the total amount of structural units derived from the conjugated diene compound and structural units derived from other copolymerizable monomers, It is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less.

The bonding form of the conjugated diene constituting the polymer block (D) containing structural units derived from the conjugated diene compound is not particularly limited. For example, butadiene can have 1,2-bond and 1,4-bond, and isoprene can have 1,2-bond, 3,4-bond and 1,4-bond. Among them, when the polymer block (D) containing a structural unit derived from a conjugated diene compound is composed of a structural unit derived from butadiene, is composed of a structural unit derived from isoprene, or is derived from both butadiene and isoprene. When composed of structural units, the total amount of 1,2-bonds and 3,4-bonds in the polymer block (D) is preferably 40 mol% or more from the viewpoint of developing high adhesive performance. . The ratio of the total amount of 1,2-bonds and 3,4-bonds to the total amount of bonds in the polymer block (D) is preferably 40 to 90 mol%, and 50 to 80 mol%. is more preferred.
The total amount of 1,2-bonds and 3,4-bonds can be calculated by ¹ H-NMR measurement. Specifically, the integrated value of the peak present at 4.2 to 5.0 ppm derived from 1,2-bonded and 3,4-bonded structural units and 5 derived from 1,4-bonded structural units It can be calculated from the ratio of the integrated values of the peaks existing at 0 to 5.45 ppm.

The form of bonding between the polymer block (S) containing a structural unit derived from an aromatic vinyl compound and the polymer block (D) containing a conjugated diene compound in the thermoplastic elastomer (A) is not particularly limited, and may be linear. The binding form may be linear, branched, radial, or a combination of two or more of these, but a linear binding form is preferred.
Examples of the linear bond form include the polymer block (S) containing a structural unit derived from an aromatic vinyl compound as a, and the polymer block (D) containing a structural unit derived from a conjugated diene compound. When represented by b, a diblock copolymer represented by ab, a triblock copolymer represented by aba or b-a-b, represented by abab a tetrablock copolymer represented by a-ba-ba or b-a-b-a-b, a pentablock copolymer represented by (a-b) nX type copolymer (X is a coupling and n represents an integer of 2 or greater), and mixtures thereof. Among these, triblock copolymers are preferred, and triblock copolymers represented by aba are more preferred.

The content of the polymer block (S) containing a structural unit derived from an aromatic vinyl compound in the thermoplastic elastomer (A) is, from the viewpoint of flexibility and mechanical properties, relative to the thermoplastic elastomer (A) as a whole. , preferably 5 to 75% by mass, more preferably 5 to 60% by mass, still more preferably 10 to 40% by mass.
The weight average molecular weight of the thermoplastic elastomer (A) is preferably 30,000 to 500,000, more preferably 50,000 to 400,000, more preferably 60, from the viewpoint of mechanical properties and moldability. ,000 to 200,000, more preferably 70,000 to 200,000, particularly preferably 70,000 to 190,000, most preferably 80,000 to 180,000. is. Here, the weight average molecular weight is the polystyrene-equivalent weight average molecular weight obtained by gel permeation chromatography (GPC) measurement.
The thermoplastic elastomer (A) may be used alone or in combination of two or more.

The method for producing the thermoplastic elastomer (A) is not particularly limited, but it can be produced, for example, by an anionic polymerization method. Specifically, (i) a method of sequentially polymerizing the aromatic vinyl compound, the conjugated diene compound, and then the aromatic vinyl compound using an alkyllithium compound as an initiator; (ii) using an alkyllithium compound as an initiator. (iii) using a dilithium compound as an initiator, the conjugated diene compound, and then the aromatic vinyl A method of sequentially polymerizing compounds can be used.

By adding an organic Lewis base during the anionic polymerization, the amount of 1,2-bonds and 3,4-bonds of the polymer block (D) in the thermoplastic elastomer (A) can be increased. The amount of 1,2-bond and 3,4-bond can be easily controlled by the amount of organic Lewis base added.
Examples of the organic Lewis base include esters such as ethyl acetate; amines such as triethylamine, N,N,N',N'-tetramethylethylenediamine (TMEDA) and N-methylmorpholine; nitrogen-containing heterocyclic compounds such as pyridine; aromatic compounds; amides such as dimethylacetamide; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran (THF) and dioxane; glycol ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; sulfoxides such as dimethyl sulfoxide; mentioned.

From the viewpoint of improving the heat resistance and weather resistance of the thermoplastic elastomer (A), part or all of the polymer block (D) containing the conjugated diene compound is hydrogenated (hereinafter abbreviated as "hydrogenated"). there is) is preferred. The hydrogenation rate of the polymer block containing the conjugated diene compound at that time is preferably 80% or more, more preferably 90% or more. Here, in this specification, the degree of hydrogenation is a value obtained by measuring the iodine value of the block copolymer before and after the hydrogenation reaction.

A hydrogenated thermoplastic elastomer (A) can be produced by subjecting an unhydrogenated thermoplastic elastomer (A) to a hydrogenation reaction. The hydrogenation reaction is carried out by dissolving the unhydrogenated thermoplastic elastomer (A) obtained above in a solvent inert to the reaction and the hydrogenation catalyst, or dissolving the unhydrogenated thermoplastic elastomer (A) is used as it is without being isolated from the above reaction solution, and reacted with hydrogen in the presence of a hydrogenation catalyst.
Moreover, a commercial item can also be used as a thermoplastic elastomer (A).

[Polypropylene resin (B)]
When the polypropylene resin (B) is included in the thermoplastic polymer composition, the molding processability is improved, and a film made of the thermoplastic polymer composition can be easily produced. In addition, the mechanical properties of the film are improved, making handling easier. Furthermore, it imparts adhesiveness to the adherend, and can be well adhered to the adherend by heat treatment.

The polypropylene-based resin (B) includes a propylene homopolymer or a copolymer of propylene and an α-olefin having 2 to 8 carbon atoms. In the case of a copolymer of propylene and an α-olefin having 2 to 8 carbon atoms, the α-olefin in the copolymer may be ethylene, butene-1, isobutene, pentene-1, hexene-1, 4-methylpentene. -1, octene-1 and the like. The polypropylene resin (B) includes, for example, homopolypropylene, propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-butene random copolymer, propylene-ethylene-butene random copolymer, propylene- Examples include pentene random copolymers, propylene-hexene random copolymers, propylene-octene random copolymers, propylene-ethylene-pentene random copolymers, propylene-ethylene-hexene random copolymers, and the like. The ratio of structural units derived from α-olefins other than propylene to all structural units possessed by the polypropylene resin (B) is preferably 0 to 45 mol% from the viewpoint of affinity with the thermoplastic elastomer (A). , more preferably 0 to 35 mol %, still more preferably 0 to 25 mol %. In other words, the content of structural units derived from propylene in the polypropylene resin (B) is preferably 55 mol% or more, more preferably 65 mol% or more, and even more preferably 75 mol% or more.
The polypropylene-based resin (B) may be used alone or in combination of two or more.

The polypropylene resin (B) can be synthesized by a conventionally known method. For example, using a Ziegler-Natta type catalyst or a metallocene type catalyst, propylene homopolymer, random or block propylene and α-olefin can be synthesized. Moreover, a commercially available product may be used as the polypropylene-based resin (B).

The melt flow rate (MFR) of the polypropylene resin (B) under conditions of 230° C. and a load of 2.16 kgf (21.18 N) is preferably 0.1 to 300 g/10 minutes, more preferably 0.1 to 100 g. /10 min, more preferably 0.1 to 70 g/10 min, more preferably 0.1 to 50 g/10 min, more preferably 1 to 30 g/10 min, even more preferably 1 to 20 g/10 min, particularly preferably is 1 to 15 g/10 minutes. If the MFR of the polypropylene-based resin (B) under the above conditions is 0.1 g/10 minutes or more, good moldability can be obtained. On the other hand, if the MFR is 300 g/10 minutes or less, the mechanical properties are likely to develop.
From the viewpoint of heat resistance, the melting point of the polypropylene resin (B) is preferably 100°C or higher, more preferably 100 to 170°C, and even more preferably 110 to 145°C.

[Polar olefin resin (C)]
The polar olefin resin (C) can enhance the adhesion to highly polar adherends by being contained in the thermoplastic polymer composition, and can be well adhered to the adherends by heat treatment. .

Examples of the polar olefin resin (C) include those obtained by incorporating a polar group into an olefin resin which is a copolymer of ethylene or propylene and an α-olefin having 2 to 8 carbon atoms. The α-olefin in the copolymer includes ethylene, propylene, butene-1, isobutene, pentene-1, hexene-1, 4-methylpentene-1, octene-1 and the like. For example, propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-butene random copolymer, propylene-ethylene-butene random copolymer, propylene-pentene random copolymer, propylene-hexene random copolymer propylene-octene random copolymers, propylene-ethylene-pentene random copolymers, propylene-ethylene-hexene random copolymers, and the like.

Examples of polar groups include (meth)acryloyloxy groups; hydroxyl groups; amide groups; halogen atoms such as chlorine atoms; carboxyl groups; The method for producing the polar group-containing polypropylene resin is not particularly limited, but it can be obtained by random copolymerization, block copolymerization or graft copolymerization of propylene and a polar group-containing copolymerizable monomer by a known method. . Among these, random copolymerization and graft copolymerization are preferred, and graft copolymers are more preferred.
In addition, it can also be obtained by subjecting an olefinic resin to a reaction such as oxidation or chlorination by a known method.

Polar group-containing copolymerizable monomers include, for example, vinyl acetate, vinyl chloride, ethylene oxide, propylene oxide, acrylamide, unsaturated carboxylic acids or their esters or anhydrides. Among these, unsaturated carboxylic acids or their esters or anhydrides are preferred. Examples of unsaturated carboxylic acids or their esters or anhydrides include (meth)acrylic acid, (meth)acrylic acid esters, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, hymic acid, and hymic anhydride. acid and the like. Among these, maleic acid and maleic anhydride are more preferable. These polar group-containing copolymerizable monomers may be used singly or in combination of two or more.
From the viewpoint of adhesion, the polar olefin resin (C) is preferably an olefin resin containing a carboxyl group as a polar group, that is, a carboxylic acid-modified olefin resin, such as maleic acid-modified olefin resin, maleic anhydride-modified olefin system resin is more preferred.

The thermoplastic polymer composition of the present invention contains 0 to 30 parts by mass of the polypropylene resin (B) with respect to 100 parts by mass of the thermoplastic elastomer (A). If the polypropylene-based resin (B) is more than 30 parts by mass, the thermoplastic polymer composition may become hard, making it difficult to develop flexibility and mechanical properties. The content of the polypropylene resin (B) is preferably 5 parts by mass or more and more preferably 25 parts by mass or less with respect to 100 parts by mass of the thermoplastic elastomer (A).
Based on these, the content of the polypropylene resin (B) is preferably 0 to 30 parts by mass, more preferably 5 to 25 parts by mass with respect to 100 parts by mass of the thermoplastic elastomer (A).
When the polar olefin resin (C) is further included, 1 to 50 parts by mass of the polar olefin resin (C) is added to 100 parts by mass of the thermoplastic elastomer (A). If the polar olefin resin (C) is less than 1 part by mass, the adhesiveness to the substrate may be insufficient. On the other hand, when the amount of the olefin resin exceeds 50 parts by mass, phase separation from the thermoplastic elastomer (A) tends to occur, which may pose a problem in terms of thermal stability.

[Other ingredients]
The thermoplastic polymer composition of the present invention may contain tackifier resins, softeners, antioxidants, lubricants, light stabilizers, processing aids, pigments, dyes, etc. Colorants, flame retardants, antistatic agents, matting agents, silicone oils, antiblocking agents, UV absorbers, release agents, foaming agents, antibacterial agents, antifungal agents, perfumes, and the like may be contained.

Examples of tackifying resins include aliphatic unsaturated hydrocarbon resins, aliphatic saturated hydrocarbon resins, alicyclic unsaturated hydrocarbon resins, alicyclic saturated hydrocarbon resins, aromatic hydrocarbon resins, and hydrogenated aromatic hydrocarbon resins. Hydrogen resin, rosin ester resin, hydrogenated rosin ester resin, terpene phenolic resin, hydrogenated terpene phenolic resin, terpene resin, hydrogenated terpene resin, aromatic hydrocarbon-modified terpene resin, coumarone/indene resin, phenolic resin, xylene resin, etc. is mentioned.

Examples of softening agents include softening agents generally used for rubbers and plastics. For example paraffinic, naphthenic and aromatic process oils; phthalic acid derivatives such as dioctyl phthalate and dibutyl phthalate; white oils, mineral oils, oligomers of ethylene and α-olefins, paraffin wax, liquid paraffin, polybutene, low molecular weight polybutadiene. , low-molecular-weight polyisoprene, and the like.

Examples of antioxidants include hindered phenol-based, phosphorus-based, lactone-based, and hydroxyl-based antioxidants. Among these, hindered phenol-based antioxidants are preferred.

The thermoplastic polymer composition of the present invention may optionally contain antioxidants, lubricants, light stabilizers, processing aids, colorants such as pigments and dyes, flame retardants, as long as the effects of the invention are not impaired. Antistatic agents, matting agents, silicone oils, antiblocking agents, ultraviolet absorbers, release agents, foaming agents, antibacterial agents, antifungal agents, fragrances, and the like may be contained.

[Method for producing thermoplastic polymer composition]
The method of preparing the thermoplastic polymer composition of the present invention is not particularly limited, but in order to increase the dispersibility of each component constituting the thermoplastic polymer composition, for example, a method of melt-kneading and mixing is recommended. be. In this case, the thermoplastic elastomer (A) and the polypropylene-based resin (B) may be simultaneously mixed and melt-kneaded with other components added as necessary. The mixing operation can be carried out using known mixing or kneading equipment such as, for example, a kneader ruder, an extruder, a mixing roll, a Banbury mixer, and the like. In particular, from the viewpoint of improving kneadability and compatibility between the thermoplastic elastomer (A) and the polypropylene-based resin (B), it is preferable to use a twin-screw extruder. The temperature during mixing and kneading should be appropriately adjusted according to the melting temperature of the thermoplastic elastomer (A), polypropylene resin (B), etc., and is usually within the range of 110°C to 300°C. Good to mix.

Thus, the thermoplastic polymer composition of the present invention can be obtained in any form such as pellets and powder. The obtained thermoplastic polymer composition can be molded into various shapes such as films, sheets, plates, pipes, tubes, rods, and granules. There are no particular restrictions on the production method of these, and various conventional molding methods such as injection molding, blow molding, press molding, extrusion molding, and calender molding can be used.

[Multilayer film]
The multilayer film of the present invention has at least a substrate layer and an adhesive layer comprising the thermoplastic polymer composition of the present invention. The substrate layer used in the multilayer film of the present invention is described below.

[Base material layer]
Although the base material layer is not particularly limited, one made of an amorphous resin is preferable. As used herein, "amorphous resin" means a resin that does not have a definite melting point in a differential scanning calorimetry (DSC) curve.
Examples of amorphous resins include polystyrene-based resins, polyvinyl chloride resins, acrylonitrile-styrene resins, ABS resins (acrylonitrile-butadiene-styrene resins), polycarbonate resins, polyester-based resins (meth)acrylic-based resins, and the like. Among them, (meth)acrylic resins, ABS resins, polycarbonate resins and polyester resins are preferable from the viewpoint of weather resistance, surface glossiness, and scratch resistance, and (meth)acrylic resins from the viewpoint of transparency or surface glossiness. is preferred.

A (meth)acrylic polymer can be used as the (meth)acrylic resin used for the substrate layer. Further, the (meth)acrylic resin used for the substrate layer is more preferably a (meth)acrylic resin composition containing a (meth)acrylic polymer, an elastic body (R), and the like.

The (meth)acrylic polymer has 80% by mass or more, preferably 90% by mass or more of structural units derived from methyl methacrylate. In other words, the structural units derived from monomers other than methyl methacrylate in the (meth)acrylic polymer should be 20% by mass or less, preferably 10% by mass or less. The (meth)acrylic polymer may be a polymer containing only methyl methacrylate as a monomer.

Examples of monomers other than methyl methacrylate include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, s-butyl acrylate, and t-acrylate. Butyl, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate; phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, 2-acrylate Hydroxyethyl, 2-ethoxyethyl acrylate, glycidyl acrylate, allyl acrylate; Acrylic esters such as cyclohexyl acrylate, norbornenyl acrylate, isobornyl acrylate; Ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate , n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, Dodecyl methacrylate; phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-ethoxyethyl methacrylate, glycidyl methacrylate, allyl methacrylate; cyclohexyl methacrylate, norbornenyl methacrylate, methacryl methacrylic acid esters other than methyl methacrylate such as isobornyl acid; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride, maleic acid and itaconic acid; Olefins; conjugated dienes such as butadiene, isoprene and myrcene; aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene and m-methylstyrene; acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl Examples include pyridine, vinyl ketone, vinyl chloride, vinylidene chloride, and vinylidene fluoride.

The stereoregularity of the (meth)acrylic polymer is not particularly limited, and for example, those having stereoregularity such as isotactic, heterotactic and syndiotactic may be used.

The weight average molecular weight of the (meth)acrylic polymer is preferably from 30,000 to 180,000, more preferably from 40,000 to 150,000, and particularly preferably from 50,000 to 130,000. If the weight-average molecular weight is small, the mechanical strength of the obtained material layer tends to decrease. If the weight-average molecular weight is too high, the flowability of the thermoplastic polymer composition tends to be low and the moldability tends to be low. In addition, a weight average molecular weight is a standard polystyrene conversion value measured by GPC (gel permeation chromatography).
Also, the molecular weight and molecular weight distribution of the (meth)acrylic polymer can be controlled by adjusting the types and amounts of the polymerization initiator and the chain transfer agent.

The method for producing the (meth)acrylic polymer is not particularly limited, and may be polymerization of a monomer (mixture) containing 80% by mass or more of methyl methacrylate, or copolymerization with a monomer other than methyl methacrylate. obtained by

A commercially available methacrylic resin may also be used as the (meth)acrylic resin. Examples of such commercially available methacrylic resins include "PARAPET H1000B" (MFR: 22 g/10 minutes (230°C, 37.3N)), "PARAPET GF" (MFR: 15 g/10 minutes (230°C, 37.3N) )), “Parapet EH” (MFR: 1.3 g/10 minutes (230° C., 37.3 N)), “Parapet HRL” (MFR: 2.0 g/10 minutes (230° C., 37.3 N)), “ Parapet HRS" (MFR: 2.4 g/10 min (230°C, 37.3 N)) and "Parapet G" (MFR: 8.0 g/10 min (230°C, 37.3 N)) [both trade names, manufactured by Kuraray Co., Ltd.] and the like.

Examples of the elastic body (R) include butadiene-based rubber, chloroprene-based rubber, block copolymer, multilayer structure, and the like, and these may be used alone or in combination. Among these, from the viewpoint of transparency, impact resistance and dispersibility, block copolymers or multilayer structures are preferable, and acrylic block copolymers (G) or multilayer structures (E) are more preferable.

The acrylic block copolymer (G) has a methacrylate polymer block (g1) and an acrylate polymer block (g2). The acrylic block copolymer (G) may have one methacrylic acid ester polymer block (g1) and one acrylic acid ester polymer block (g2), or may have a plurality of them.

The methacrylic acid ester polymer block (g1) has structural units derived from methacrylic acid ester as main structural units. The ratio of structural units derived from methacrylic acid ester in the methacrylic acid ester polymer block (g1) is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass, from the viewpoint of stretchability and surface hardness. It is at least 98% by mass, particularly preferably at least 98% by mass.

A method for producing the acrylic block copolymer (G) is not particularly limited, and a method according to a known technique can be employed. For example, a method of living polymerization of monomers constituting each polymer block is generally used. . Examples of such living polymerization techniques include a method of anionic polymerization in the presence of a mineral acid salt such as an alkali metal or alkaline earth metal salt using an organic alkali metal compound as a polymerization initiator; a method of anionic polymerization using an organic rare earth metal complex as a polymerization initiator; a method of radical polymerization using an α-halogenated ester compound as an initiator in the presence of a copper compound. etc. Further, a method of polymerizing monomers constituting each block using a polyvalent radical polymerization initiator or a polyvalent radical chain transfer agent to produce a mixture containing the acrylic block copolymer (G) may be used. Among these methods, the acrylic block copolymer (G) can be obtained with high purity, the molecular weight and composition ratio can be easily controlled, and the organic alkali metal compound is used as the polymerization initiator because it is economical. A method of anionic polymerization in the presence of an organoaluminum compound is preferred.

The multilayer structure (E) contains at least two layers, an inner layer and an outer layer, and has at least one layer structure in which the inner layer and the outer layer are arranged in this order from the center layer toward the outermost layer. The multilayer structure (E) may further have a crosslinkable resin layer inside the inner layer or outside the outer layer.

The inner layer is a layer composed of a crosslinked elastic body obtained by copolymerizing a monomer mixture containing an acrylic acid alkyl ester and a crosslinkable monomer. As such alkyl acrylates, alkyl acrylates in which the number of carbon atoms in the alkyl group is in the range of 2 to 8 are preferably used, and examples thereof include butyl acrylate and 2-ethylhexyl acrylate. The proportion of the alkyl acrylate ester in the total monomer mixture used to form the inner layer copolymer is preferably in the range of 70 to 99.8% by mass, more preferably in terms of impact resistance. is 80 to 90% by mass.

The outer layer is composed of a rigid thermoplastic resin obtained by polymerizing a monomer mixture containing 80% by mass or more, preferably 90% by mass or more of methyl methacrylate, from the viewpoint of the heat resistance of the substrate layer. Further, the rigid thermoplastic resin contains 20% by mass or less, preferably 10% by mass or less of other monofunctional monomers. Other monofunctional monomers include acrylic acid alkyl esters such as methyl acrylate, butyl acrylate and 2-ethylhexyl acrylate; acrylic acid; methacrylic acid and the like.

The contents of the inner layer and the outer layer in the multilayer structure (E) are determined from the viewpoint of impact resistance, heat resistance, surface hardness, handleability, ease of melt-kneading, etc. of the resulting substrate layer. The content of the inner layer is selected from the range of 40 to 80% by mass, and the content of the outer layer is selected from the range of 20 to 60% by mass, based on the mass of (for example, the total amount of the inner and outer layers when consisting of two layers). preferably

Although the method for producing the multilayer structure (E) is not particularly limited, it is preferably produced by emulsion polymerization from the viewpoint of controlling the layer structure of the multilayer structure (E).

The amorphous resin constituting the base material layer preferably has an elastic modulus of 2 to 600 MPa at an arbitrary temperature in the range of 110 to 160°C. If the elastic modulus is less than 2 MPa, the elongation tends to be uneven during vacuum forming, and if the elastic modulus is greater than 600 MPa, cracking or breakage tends to occur during vacuum forming. The elastic modulus is a value obtained by rounding off to the first decimal place when expressed in units of [MPa].

The amorphous resin constituting the base material layer contains various additives such as antioxidants, heat stabilizers, lubricants, processing aids, antistatic agents, heat deterioration inhibitors, ultraviolet absorbers, light stabilizers, polymers. It may also contain processing aids, colorants, impact resistance aids, and the like.

Also, the above amorphous resin can be used by mixing with other polymers. Such other polymers include polyolefin resins such as polyethylene, polypropylene (PP), polybutene-1, poly-4-methylpentene-1, and polynorbornene; ethylene-based ionomers; polystyrene, styrene-maleic anhydride copolymers. , high impact polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer (ABS), acrylonitrile-ethylene-styrene copolymer, acrylonitrile-acrylate-styrene copolymer resin, acrylonitrile-chlorinated polyethylene - styrene resins such as styrene copolymers, methyl methacrylate-butadiene-styrene copolymers; methyl methacrylate-styrene copolymers; polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate; nylon 6, nylon 66, Polyamide such as polyamide elastomer; polycarbonate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacetal, polyvinylidene fluoride, polyurethane, modified polyphenylene ether, polyphenylene sulfide, silicone modified resin; acrylic rubber, silicone Rubber: Styrenic thermoplastic elastomers such as styrene-ethylene/propylene-styrene copolymer, styrene-ethylene/butadiene-styrene copolymer, styrene-isoprene-styrene copolymer; isoprene rubber, ethylene propylene rubber, ethylene propylene diene Olefin-based rubbers such as rubbers can be used.

The method for preparing the amorphous resin constituting the base material layer is not particularly limited, but a method of melt-kneading and mixing is preferable in order to increase the dispersibility of each component constituting the amorphous resin. For the mixing operation, a known mixing or kneading device such as a kneader ruder, an extruder, a mixing roll, or a Banbury mixer can be used, and from the viewpoint of improving kneadability and compatibility, it is preferable to use a twin screw extruder. The temperature during mixing and kneading may be appropriately adjusted according to the melting temperature of the amorphous resin to be used, and is usually in the range of 110 to 300°C. When melt-kneading using a twin-screw extruder, it is preferable to use a vent and melt-knead under reduced pressure and/or in a nitrogen atmosphere from the viewpoint of suppressing coloring.

[Other layers]
The multilayer film of the present invention may be made into a decorative film by printing patterns such as pictures, letters, figures, etc. or colors on the substrate layer and/or the adhesive layer. The pattern may be chromatic or achromatic. Examples of printing methods include known printing methods such as gravure printing, offset printing, screen printing, transfer printing, and ink jet printing. In printing, a resin composition containing a resin such as polyvinyl resin, polyester resin, acrylic resin, polyvinyl acetal resin, cellulose resin, etc., as a binder and a pigment or dye as a colorant, which is generally used in such a printing method. is preferably used.

The multilayer film of the present invention may be a decorative film having a colored base layer. As a coloring method, the amorphous resin itself contains a pigment or dye to color the resin itself before being formed into a film; the amorphous resin film is immersed in a liquid in which the dye is dispersed for coloring. Examples include dyeing methods, but are not particularly limited thereto.

The multilayer film of the present invention may be a decorative film in which a metal or metal oxide is vapor-deposited on a substrate layer. As such metals or metal oxides, metals or metal oxides used in sputtering, vacuum deposition, etc. can be used without particular limitation, such as gold, silver, copper, aluminum, zinc, nickel, chromium, indium, and oxides thereof. etc. Moreover, these metals or metal oxides may be used singly or as a mixture of two or more. Methods for vapor-depositing a metal or metal oxide on the substrate layer include vacuum film-forming methods such as vapor deposition and sputtering, electrolytic plating, and electroless plating.

The substrate layer side surface of the multilayer film of the present invention preferably has a pencil hardness of HB or higher, more preferably H or higher. If the pencil hardness is higher than HB, the multi-layer film is less likely to be damaged, and can be suitably used as a decorative and protective film for the surface of molded articles that require good design.

The total thickness of the multilayer film of the present invention is preferably in the range of 20-1,000 μm, more preferably in the range of 50-500 μm, even more preferably in the range of 100-250 μm. If the thickness of the multilayer film is 20 μm or more, it is easy to manufacture, excellent in impact resistance and reduction in warping when heated, and has hiding properties when colored. When the thickness of the multilayer film is 1,000 μm or less, the three-dimensional coating formability tends to be improved.

In the multilayer film of the present invention, the thickness of the substrate layer is preferably 500 µm or less. If the thickness is more than 500 μm, secondary workability such as laminating property, handling property, cutting property and punching property will be deteriorated, making it difficult to use as a film, and the unit price per unit area will increase, which is economically disadvantageous. I don't like it because The thickness of the substrate layer is more preferably 40-300 μm, particularly preferably 50-250 μm.

The ratio (y/x) of the thickness (y) of the base material layer to the thickness (x) of the adhesive material layer is preferably in the range of 0.2 to 5, more preferably 0.5 to 4. and more preferably in the range of 0.8 to 3. When the value of the ratio (y/x) is less than 0.2, the surface hardness tends to be low. become a trend.

[Manufacturing method of multilayer film]
The multilayer film of the present invention has a substrate layer and an adhesive layer, and can be obtained by laminating the adhesive layer on one surface of the substrate layer.

The method for producing the substrate layer is not particularly limited. For example, when an amorphous resin is used, known methods such as a T-die method, inflation method, melt casting method, calendar method, etc. can be used. From the viewpoint of obtaining a film with good surface smoothness and low haze, the melt-kneaded material of the amorphous resin constituting the base layer is extruded in a molten state from a T-die, and both sides thereof are coated with a mirror roll surface or a mirror belt surface. A method comprising the step of molding in contact with is preferred. Any of the rolls or belts used at this time is preferably made of metal. When both sides of the extruded melt-kneaded material are brought into contact with a mirror surface to form a film, it is preferable to press and sandwich both sides of the film with a mirror surface roll or a mirror surface belt. The nipping pressure by the mirror-finished rolls or mirror-finished belt is preferably high, and the linear pressure is preferably 10 N/mm or more, more preferably 30 N/mm or more.

The base layer may be a stretched film. The stretching process increases the mechanical strength and makes cracking less likely. The stretching method is not particularly limited, and includes a simultaneous biaxial stretching method, a sequential biaxial stretching method, a tubular stretching method, a rolling method and the like.

Lamination of the adhesive layer on the substrate layer obtained as described above includes a method of applying a solution of the thermoplastic polymer composition constituting the adhesive layer to the substrate layer, A method of laminating a film comprising the thermoplastic polymer composition can be mentioned. A film made of the thermoplastic polymer composition can be obtained in the same manner as the method for producing the substrate layer exemplified above.
Alternatively, the amorphous resin forming the substrate layer and the thermoplastic polymer composition forming the adhesive layer may be co-extruded using a T-die method. A co-extrusion method using a multi-manifold die is particularly preferred. At this time, the side in contact with the base material layer is a metal roll, and the side in contact with the adhesive layer is a silicone roll having a roll surface made of a silicone resin or coated with silicone. It is suitable because it is easy to prevent troubles that are wrapped around.

[Molded body]
The molded article of the present invention has the multilayer film of the present invention or a decorative film made of the multilayer film on the surface of an adherend. More preferably, the multilayer film of the present invention is provided on the surface of an adherend made of other thermoplastic resin, thermosetting resin, wood base material or non-wood fiber base material.

Other thermoplastic resins used for the adherend include polycarbonate resins, polyethylene terephthalate resins, polyamide resins, polyethylene resins, polypropylene resins, polystyrene resins, polyvinyl chloride resins, other (meth)acrylic resins, ABS (acrylonitrile -butadiene-styrene copolymer) resin. Other thermosetting resins include epoxy resins, phenolic resins, melamine resins, and the like. Moreover, the molded article may be one in which the multilayer film of the present invention is provided on the surface of an adherend made of a wooden base material or non-woody fibers such as kenaf. Since the adhesive layer of the present invention is particularly excellent in adhesion to olefin resins, it is highly effective when the adherend is made of polypropylene resin.

A method for producing the molded article is not particularly limited. For example, the multilayer film of the present invention is subjected to vacuum molding, air pressure molding, or compression molding under heating onto the surface of an adherend such as other thermoplastic resins, thermosetting resins, wooden substrates, and non-woody fiber substrates. Thus, the molded article of the present invention can be obtained. The molded article has the substrate layer in the multilayer film of the present invention provided as the outermost layer of the molded article, and is therefore excellent in surface hardness, surface gloss, and the like.

Another preferred method for producing a molded body is a method generally called injection molding simultaneous lamination method.
In this injection molding simultaneous lamination method, the multilayer film of the present invention is inserted between male and female molds for injection molding, and a molten thermoplastic resin is injected from the adhesive layer side of the film into the molds, followed by injection molding. In this method, a body is formed as an adherend, and at the same time, the multilayer film is laminated on the surface of the injection molded body.

The multilayer film to be inserted into the mold may be flat as it is, or may be preformed by vacuum forming, pressure forming, or the like and shaped into an uneven shape.
The preforming of the multilayer film may be carried out in a separate molding machine, or may be carried out in the mold of an injection molding machine used in the simultaneous injection molding lamination method.

The multi-layer film of the present invention or a molded article having the multi-layer film on the surface of an adherend has good designability, making use of the good stretchability and moldability of the multi-layer film, excellent bipolar adhesiveness and surface smoothness. It can be applied to the requested article. For example, signboard parts such as advertising towers, stand signs, sleeve signs, transom signs, roof signboards; display parts such as showcases, partitions, store displays; fluorescent lamp covers, mood lighting covers, lampshades, light ceilings, light walls , lighting parts such as chandeliers; interior parts such as furniture, pendants, mirrors; doors, domes, safety window glass, partitions, stair waistboards, balcony waistboards, building parts such as roofs for leisure buildings, interior and exterior parts for automobiles, Parts related to transportation equipment such as automotive exterior parts such as bumpers; Electronic device parts such as audiovisual nameplates, stereo covers, vending machines, mobile phones, personal computers, etc.; , bathroom members, clock panels, bathtubs, sanitary goods, desk mats, game parts, toys, wallpapers; marking films; Since the multilayer film of the present invention has the properties described above, it can be used particularly preferably as a decorative film.

EXAMPLES The present invention will be described in more detail below with reference to Examples, etc., but the present invention is not limited to these Examples. Preparation of test samples and measurement or evaluation of physical properties in Examples and Comparative Examples were carried out as follows.

[Viscoelasticity evaluation of thermoplastic polymer composition]
Pellets of the thermoplastic polymer compositions shown in Examples and Comparative Examples to be described later were compression molded for 2 minutes at 200° C. and a load of 50 kgf/cm ² using a compression molding machine to obtain a thermoplastic polymer. A 150×150 mm sheet of coalesced composition was obtained. A test piece of 10 x 20 mm was cut out from the obtained sheet, and a dynamic viscoelasticity measuring device (Rheogel-4000 manufactured by UBM Co., Ltd.) was used to perform temperature dispersion measurement. The tan δ at 20°C was measured.

[Adhesion strength (PP) of thermoplastic polymer composition]
Pellets of the thermoplastic polymer compositions obtained in Examples and Comparative Examples and the methacrylic resin composition obtained in Production Example 5 were molded using a compression molding machine under the conditions of 200° C. and a load of 50 kgf/cm ² . A sheet of the thermoplastic polymer composition and a sheet of the methacrylic resin composition were obtained by compression molding for minutes. 150×150 mm thermoplastic polymer composition sheet (length 150 mm×width 150 mm×thickness 0.5 mm), polyimide film (manufactured by DuPont Toray Co., Ltd. Kapton film, length 75 mm×width 150 mm×thickness 0.05 mm) , Polypropylene sheets (MA3 manufactured by Japan Polypropylene Co., Ltd., length 150 mm x width 150 mm x thickness 0.4 mm) are stacked in this order and placed in the center of a metal spacer with an inner dimension of 150 mm x 150 mm and a thickness of 0.8 mm. bottom. The stacked sheets and metal spacers are sandwiched between polytetrafluoroethylene sheets, and ^further sandwiched between metal plates from the outside. A multilayer film of a thermoplastic polymer composition and a methacrylic resin composition was obtained.
The multilayer film was cut to a width of 25 mm and used as a test piece for measuring adhesive strength, and the peel strength between the thermoplastic polymer composition and the methacrylic resin composition was measured according to JIS K 6854-2 using a peel tester (Shimadzu Corporation). AGS-X (manufactured by AGS-X) was used to measure the adhesive strength (PP) of the thermoplastic polymer composition under the conditions of a peel angle of 90°, a tensile speed of 300 mm/min, and an environmental temperature of 23°C.

[Evaluation of Chipping Resistance of Molded Body]
Pellets of the thermoplastic polymer composition obtained in Example 1 and pellets of the methacrylic resin composition obtained in Production Example 5 were each added to the hopper of a single-screw extruder (VGM25-28EX manufactured by GM Engineering). It was charged and coextruded at 240° C. and a flow rate of 5 kg/h using a multi-manifold die to obtain a multilayer film with a width of 30 cm. In addition, polypropylene (J708UG manufactured by Prime Polymer Co., Ltd.) was put into an injection molding machine (SG-100 manufactured by Sumitomo Heavy Industries, Ltd.) and injected at 230 ° C. to obtain polypropylene of 100 mm long × 40 mm wide × 3 mm thick. A compact was obtained.
A 100×40 mm multilayer film comprising a thermoplastic polymer composition and a base material and a polypropylene molded body (length 100 mm×width 40 mm×thickness 3 mm) were stacked in this order. The stacked sheets were sandwiched between polytetrafluoroethylene sheets and further sandwiched between metal plates from the outside, and compressed for 2 minutes at a load of 50 kgf/cm ² using a compression molding machine heated to the temperature shown in each example and comparative example. By molding, a molded article composed of a multilayer film and a polypropylene molded article was obtained.

On the methacrylic resin composition side of the molded body, using a Gravelo tester manufactured by Suga Test Instruments, the test piece temperature is -20 ° C., the shot material spraying axis is 90 degrees, and the air pressure is 0.4 MPa. 50 g of No. 7 crushed stone was collided from a distance of 350 mm from. The surface of the compact after collision was visually observed.
×: 10 or more peeling spots were observed △: 1 to 9 peeling spots were observed ○: No peeling was observed

In addition, each component used in the following examples and comparative examples is as follows.

<Production Example 1> [Synthesis of thermoplastic elastomer (A-1)]
The pressure container was dried by purging the pressure container with nitrogen in advance. In such a pressure vessel, 50.0 kg of cyclohexane as a solvent, 94.1 g of a 10.5% by mass cyclohexane solution of sec-butyllithium as an anionic polymerization initiator (equivalent to 9.9 g of sec-butyllithium), and 300 g of tetrahydrofuran as a Lewis base were added. I prepared. The solution was heated to 50°C. After adding 1.25 kg of styrene (1) to the solution, a polymerization reaction was carried out for 1 hour. Subsequently, 10.00 kg of isoprene was added to the solution, followed by a polymerization reaction for 2 hours. Further, 1.25 kg of styrene (2) was added to the solution, and the polymerization reaction was carried out for 1 hour. Thus, a reaction liquid containing a styrene-isoprene-styrene triblock copolymer was obtained.

To this reaction solution, palladium carbon was added as a hydrogenation catalyst in an amount of 5% by mass per 100% by mass of the block copolymer. The supported amount of palladium per 100% by mass of palladium carbon is 5% by mass. A reaction was carried out for 10 hours under an environment of a hydrogen pressure of 2 MPa and a temperature of 150°C. The reaction was allowed to cool and depressurized. Thereafter, palladium carbon is removed from the reaction solution by filtration, the filtrate is concentrated, and the concentrated solution is vacuum-dried to obtain a block copolymer (a-1) which is a hydrogenated product of a styrene-isoprene-styrene triblock copolymer. ).

<Production Example 2> [Synthesis of styrenic thermoplastic elastomer (A-2)]
A nitrogen-purged and dried pressure vessel was charged with 50.0 kg of cyclohexane as a solvent and 61.1 g of sec-butyllithium (10.5% by mass cyclohexane solution) as an anionic polymerization initiator (6.42 g of sec-butyllithium). After heating to 50° C., 0.81 kg of styrene (1) was added and polymerized for 1 hour, 10.87 kg of isoprene was added and polymerized for 2 hours, and 0.81 kg of styrene (2) was added to Polymerization was carried out for 1 hour to obtain a reaction liquid containing a styrene-isoprene-styrene triblock copolymer.
To this reaction solution, 5% by mass of palladium on carbon (amount of palladium supported: 5% by mass) relative to the block copolymer was added as a hydrogenation catalyst, and the reaction was carried out for 10 hours under conditions of a hydrogen pressure of 2 MPa and 150°C. .
After allowing to cool and release the pressure, palladium carbon is removed by filtration, and the filtrate is concentrated and further vacuum-dried to obtain a hydrogenated styrene-isoprene-styrene triblock copolymer (A-2-1). rice field.

In the same manner as in the procedure for obtaining the hydrogenated product (A-2-1), 50.0 kg of cyclohexane as a solvent and sec-butyllithium (10. 420.0 g of a 5% by mass cyclohexane solution) (44.1 g of sec-butyllithium) was charged, heated to 50° C., 2.83 kg of styrene (1) was added and polymerized for 1 hour, followed by 19.81 kg of isoprene. was added and polymerization was carried out for 2 hours to obtain a reaction liquid containing a styrene-isoprene diblock copolymer.
This reaction solution was hydrogenated in the same manner as above to obtain a hydrogenated styrene-isoprene diblock copolymer (A-2-2).
(A-2-1) and (A-2-2) obtained above are kneaded at a screw speed of 300 rpm and a kneading temperature of 200° C. using a twin-screw extruder ZSK26 MegaCompounder (L/D=54) manufactured by Coperion Co., Ltd. The mixture was melt-kneaded to obtain a styrenic thermoplastic elastomer composition (A-2).

<Production Example 3> [Synthesis of styrene-based thermoplastic elastomer (A-3)]
50.0 kg of cyclohexane as a solvent and 170.6 g of sec-butyllithium (10.5% by mass cyclohexane solution) as an anion polymerization initiator (17.91 g of sec-butyllithium) were charged into a pressure vessel that had been purged with nitrogen and dried. After raising the temperature to 50° C., 1.87 kg of styrene (1) was added and polymerized for 1 hour, then 8.75 kg of butadiene was added and polymerized for 2 hours, and 1.87 kg of styrene (2) was added. Polymerization was carried out for 1 hour to obtain a reaction liquid containing a styrene-butadiene-styrene triblock copolymer.
To this reaction solution, 5% by mass of palladium on carbon (amount of palladium supported: 5% by mass) relative to the block copolymer was added as a hydrogenation catalyst, and the reaction was carried out for 10 hours under conditions of a hydrogen pressure of 2 MPa and 150°C. .

After allowing to cool and release the pressure, palladium carbon is removed by filtration, and the filtrate is concentrated and further vacuum-dried to obtain a hydrogenated styrene-butadiene-styrene triblock copolymer (A-3-1). rice field.
In the same manner as in (A-3-1), 50.0 kg of cyclohexane as a solvent and 313.5 kg of sec-butyllithium (10.5% by mass cyclohexane solution) as an anion polymerization initiator were placed in a pressure-resistant container that had been purged with nitrogen and dried. 1 g (32.9 g of sec-butyllithium) was charged and the temperature was raised to 50° C., 3.75 kg of styrene (1) was added and polymerized for 1 hour, and then 8.75 kg of butadiene was added and polymerized for 2 hours. , a reaction solution containing a styrene-butadiene diblock copolymer was obtained.

This reaction liquid was hydrogenated in the same manner as in (A-3-1) to obtain a hydrogenated styrene-butadiene diblock copolymer (A-3-2).
(A-3-1) and (A-3-2) obtained above are kneaded at a screw speed of 300 rpm and a kneading temperature of 200° C. using a twin-screw extruder ZSK26MagaCompounder (L/D=54) manufactured by Coperion Co., Ltd. A thermoplastic elastomer composition (A-3) was obtained by melt-kneading.

[Polypropylene resin (B-1)]
WFX4TA (MFR at 230° C. 7 g/10 min) manufactured by Nippon Polypropylene Co., Ltd. was used as the polypropylene resin (B-1).

<Production Example 4> [Synthesis of polar group-containing polypropylene resin ( C -2)]
42 g of polypropylene “Prime Polypro F327” (manufactured by Prime Polymer Co., Ltd.), 160 mg of maleic anhydride and 42 mg of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane were mixed at 180° C. using a batch mixer and a screw Melt-kneading was performed at a rotation speed of 40 rpm to obtain a polar group-containing polypropylene resin ( C -2). The MFR [230°C, load 2.16 kgf (21.18 N)] of the resulting polar group-containing polypropylene resin ( C -2) was 6 g/10 min, the maleic anhydride concentration was 0.3%, and the melting point was It was 138°C. The maleic anhydride concentration is a value obtained by titrating the obtained kneaded material with a methanol solution of potassium hydroxide. The melting point is the value read from the endothermic peak of the differential scanning calorimetry curve when the temperature is raised at 10°C/min.

[Polypropylene resin (B-3)]
As the polypropylene resin (B-3), Tafmer ^™ XM7090 (MFR at 230° C. 7 g/10 min) manufactured by Mitsui Chemicals, Inc. was used.

[Polar olefin resin (C-1)]
As the polypropylene-based resin (C-1), Tafmer ^™ MA8510 (MFR at 230° C. of 5.0 g/10 min) manufactured by Mitsui Chemicals, Inc. was used.

<Production Example 5> [Synthesis of (meth)acrylic resin]
Polymerization initiator (2,2'-azobis (2-methylpropionitrile), hydrogen abstraction capacity: 1%, 1 hour half-life Temperature: 83° C.) and 0.28 parts by mass of a chain transfer agent (n-octyl mercaptan) were added and dissolved to obtain a raw material liquid.
A mixture was obtained by mixing 100 parts by mass of ion-exchanged water, 0.03 parts by mass of sodium sulfate and 0.45 parts by mass of a suspension dispersant. A pressure-resistant polymerization tank was charged with 420 parts by mass of the mixed solution and 210 parts by mass of the raw material solution, and the temperature was raised to 70° C. to initiate a polymerization reaction while stirring in a nitrogen atmosphere. After 3 hours from the initiation of the polymerization reaction, the temperature was raised to 90° C. and stirring was continued for 1 hour to obtain a liquid in which the bead-like copolymer was dispersed. The resulting copolymer dispersion was washed with an appropriate amount of ion-exchanged water, and the bead-like copolymer was taken out with a bucket-type centrifuge and dried with a hot air dryer at 80° C. for 12 hours. ) to obtain an acrylic resin. The obtained (meth)acrylic resin had a weight average molecular weight of 30,000 and a Tg of 128°C.

<Production Example 6> [Multilayer structure]
1050 parts by mass of ion-exchanged water, 0.5 parts by mass of sodium dioctylsulfosuccinate and 0.7 parts by mass of sodium carbonate were placed in a reactor equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, a monomer inlet tube and a reflux condenser. was charged, the inside of the container was sufficiently replaced with nitrogen gas, and the inside temperature was set to 80°C. After adding 0.25 parts by mass of potassium persulfate thereto and stirring for 5 minutes, a monomer consisting of methyl methacrylate: methyl acrylate: allyl methacrylate = 94: 5.8: 0.2 (mass ratio) 245 parts by mass of the mixture was continuously added dropwise for 50 minutes, and after completion of the dropwise addition, the polymerization reaction was further performed for 30 minutes.
Next, 0.32 parts by mass of potassium peroxodisulfate was added to the same reactor and stirred for 5 minutes. 315 parts by mass of the solid mixture was continuously added dropwise over 60 minutes, and after the completion of the dropwise addition, the polymerization reaction was further carried out for 30 minutes.
Subsequently, 0.14 parts by mass of potassium peroxodisulfate was charged into the same reactor and stirred for 5 minutes, and then 140 parts by mass of a monomer mixture consisting of methyl methacrylate:methyl acrylate = 94:6 (mass ratio) was added. The solution was continuously supplied dropwise over 30 minutes, and after completion of the dropwise addition, a polymerization reaction was further carried out for 60 minutes to obtain a multilayer structure.

<Production Example 7> [Base material layer]
20 parts by mass of the multilayer structure obtained in Production Example 6 and 80 parts by mass of the (meth)acrylic resin obtained in Production Example 5 were extruded using a twin-screw extruder (TEM-28 manufactured by Toshiba Machine Co., Ltd.). After melt-kneading at 230° C., the mixture was extruded into strands and cut to produce pellets (P) of the methacrylic resin composition.

<Example 1>
Thermoplastic elastomers (A-1) to (A-3) and polypropylene resin (B-1) were charged into a twin-screw extruder (KZW15-30MG manufactured by Technobel) at the ratios shown in Table 1 and extruded at 225°C. , 250 rpm, extruded into strands and cut to obtain pellets of the thermoplastic polymer composition.
The viscoelasticity, adhesive strength (PP), and chipping resistance of the molded article of the resulting thermoplastic polymer composition were evaluated by the methods described above. Table 1 shows the results.

<Examples 2 to 9, Comparative Examples 1 to 5, Reference Example 1>
Thermoplastic elastomers (A-1) to (A-3) and polypropylene resins (B-1) to (B-3) and (C-1) were mixed in the proportions shown in Table 1. Pellets of a thermoplastic polymer composition were obtained in the same manner as in Example 1. The resulting thermoplastic polymer composition was evaluated by the method described above. Table 1 shows the results.

In Example 1, the loss tangent (tan δ) of the thermoplastic polymer composition at 11 Hz in the -50 to -20°C range was 3 × 10 ^-2 or more, and the composition exhibited high adhesive strength to polypropylene. . The molded article using the thermoplastic polymer composition of Example 1 for the adhesive layer exhibited high chipping resistance. This is believed to be due to the excellent low-temperature impact resistance of the thermoplastic polymer composition. From this, it became clear that the multilayer film of the present invention is suitable as a decorative film having excellent chipping resistance.
On the other hand, the thermoplastic polymer composition of Comparative Example 1, which has a loss tangent (tan δ) at 11 Hz in the range of −50 to −20° C. of 3×10 ⁻² or less, is similar to Example 1 to polypropylene. Although excellent adhesive strength was exhibited, the molded article using this thermoplastic polymer composition for the adhesive layer had poor chipping resistance.
Even when the thermoplastic polymer composition of Comparative Example 1 is used for the adhesive layer, when the adhesive layer is thick as in Reference Example 1 and the temperature during press bonding is high, polypropylene The adhesion strength to the adhesive was very excellent, and the chipping resistance was also good. From the above, it can be seen that the multilayer film of the present invention can exhibit high chipping resistance even when the thickness of the adhesive layer is thin and the lamination temperature is low.

The thermoplastic polymer composition of Example 2, in which the content of the polypropylene resin (B) was changed from that of Example 1, had a loss tangent (tan δ) at 11 Hz in the range of −50 to −20° C. of 3×10. ⁻² or higher, indicating high adhesive strength to polypropylene, and the molded article using the thermoplastic polymer composition for the adhesive layer exhibited high chipping resistance. In Examples 3 to 6, the same thermoplastic polymer composition as in Example 1 was used to change the adhesive strength with polypropylene. It showed chipping property.
In addition, the thermoplastic polymer compositions of Examples 7 to 9, in which the type of polypropylene resin (B) was changed and the polar olefin resin (C) was added, had a loss at 11 Hz in the range of -50 to -20 ° C. It had a tangent (tan δ) of 3×10 ⁻² or more, exhibited high adhesive strength to polypropylene, and a molded article using the thermoplastic polymer composition for the adhesive layer exhibited high chipping resistance.

On the other hand, the thermoplastic polymer compositions of Comparative Examples 2 to 4 had a loss tangent (tan δ) at 11 Hz in the range of −50 to −20° C. of 3×10 ⁻² or less, and chipping resistance similar to that of Comparative Example 1. was nasty. The thermoplastic polymer composition of Comparative Example 5 has a loss tangent (tan δ) at 11 Hz in the range of −50 to −20° C. of 3×10 ⁻² or more. When the lamination temperature was low, the adhesion strength to polypropylene was low, and the chipping resistance was also poor.

As described above, the multilayer film comprising the adhesive layer made of the thermoplastic polymer composition of the present invention has a thin adhesive layer and exhibits high chipping resistance even at low lamination temperatures. Since it can be expressed, it can be suitably used as a multilayer film for vehicle exteriors.

This application claims priority based on Japanese Patent Application No. 2018-077682 filed on April 13, 2018, and the entire disclosure thereof is incorporated herein.

Claims (10)

A multilayer film comprising a substrate layer and an adhesive layer, wherein the adhesive layer comprises
containing a polymer block (S) containing a structural unit derived from an aromatic vinyl compound and a polymer block (D) containing a structural unit derived from a conjugated diene compound; At least two types of block copolymers , which are a diblock copolymer represented by ab and a triblock copolymer represented by aba, where the united block (D) is represented by b 5 to 30 parts by mass of a polypropylene resin (B) containing no polar group and 1 to 50 parts by mass of a polar olefin resin (C) are added to 100 parts by mass of a thermoplastic elastomer (A) made of a hydrogenated product of The thermoplastic polymer composition ^containing the A multilayer film characterized by : 2. The multilayer film according to claim 1, wherein the structural unit derived from the conjugated diene compound constituting the polymer block (D) is a structural unit derived from at least one selected from butadiene and isoprene. 2. The multilayer film according to claim 1, wherein the base material layer comprises an amorphous resin. 4. The multilayer film according to claim 3, wherein the amorphous resin is any one of (meth)acrylic resin, ABS resin, polycarbonate resin and polyester resin. The multilayer film according to any one of claims 1 to 4, wherein the multilayer film is a decorative film. 6. A method for producing a multilayer film according to any one of claims 1 to 5, characterized in that the substrate layer and the adhesive layer are co-extruded. 7. The method for producing a multilayer film according to claim 6, wherein nip molding is performed using a metal roll on the side in contact with the base material layer and a silicone roll on the side in contact with the adhesive layer. A molded article comprising the multilayer film according to any one of claims 1 to 5 on the surface of an adherend. The molded article according to claim 8, wherein the adherend is a polypropylene resin. A step of preforming the multilayer film according to any one of claims 1 to 5 by vacuum forming;
placing the preshaped multilayer film in a mold such that the substrate layer is in contact with the mold;
injection molding a thermoplastic resin that forms the adherend after closing the mold;
A method for producing a molded body having