JP6998948B2 - Laminated film, laminated molded body, and manufacturing method thereof - Google Patents

Description

The present invention relates to a laminated film, a laminated molded body, and a method for producing these.

Generally, a protective film is laminated on an interior or exterior member used in an automobile or the like for the purpose of surface protection, improvement of scratch resistance, improvement of design, and the like. In the present specification, a molded body on which a protective film is laminated is referred to as an "adhesive molded body", and an adhered molded body on which a protective film is laminated is referred to as a "laminated molded body".
When the adherend is a three-dimensional shape, the conventional method for manufacturing a laminated molded article is a step of manufacturing an adherend, a step of manufacturing a protective film, and protection according to the three-dimensional shape of the adherend. It includes a step of preforming the film, a step of trimming the preformed protective film as needed, and a step of laminating the preformed protective film onto the adherend.

In recent years, a method has been proposed in which a protective film is manufactured, preformed, trimmed if necessary, and then film insert molding is performed in which an adherend is molded in the presence of the preformed protective film.
As a protective film for film insert molding, Patent Document 1 discloses an acrylic film made of a resin composition in which acrylic multilayer structure rubber particles are dispersed in a methacrylic resin (claim 1). Patent Document 2 discloses an insert film in which an acrylic resin layer is laminated on both sides of a polycarbonate resin layer (claim 1).

Japanese Unexamined Patent Publication No. 11-147237 Japanese Unexamined Patent Publication No. 2014-14896

The protective film described in Patent Document 1 has an effect of improving the surface hardness (paragraph 0023, etc.), but because it lacks flexibility, it does not suitablely follow the curved surface of the mold during preform, and cracks occur in the film. May occur. Film cracks can also occur during trimming.

In the protective film described in Patent Document 2, the flexibility is improved by the polycarbonate-based resin layer, and the above-mentioned problems can be solved (paragraph 0007). However, since the insert film described in Patent Document 2 contains a polycarbonate-based resin layer having high heat resistance, if the temperature at the time of preformation is too low for the polycarbonate-based resin, the polycarbonate-based resin will not be sufficiently softened and formability. Alternatively, the interlayer adhesion of the film may deteriorate. If the temperature at the time of preform is raised in accordance with the polycarbonate resin, the surface roughness of the acrylic resin layer forming the surface layer may increase due to heat. It is preferable that the preform can be performed satisfactorily without deteriorating the surface roughness of the surface layer.

The present invention has been made in view of the above problems, is suitable for use in film insert molding, has good surface hardness, and has good shapeability, surface condition, and crack resistance during preformation. It is an object of the present invention to provide a laminated film having good crack resistance during trimming.
Although the laminated film of the present invention is suitable for use in film insert molding, it can be used for any purpose.

The present invention provides the laminated films, laminated molded bodies, and methods for producing these according to the following [1] to [8].
[1] A laminated film having a surface layer containing a methacrylic resin (A) and a binder layer containing a thermoplastic resin (B).
The deflection temperature under load of the constituent material of the surface layer is HDa, the deflection temperature under load of the constituent material of the binder layer is HDb, the total thickness of the laminated film is T (mm), and the thickness of the surface layer is Ta (however, Ta is). The thickness of the binder layer is Tb (mm), and the concentration of acrylic acid alkyl ester units having 6 to 12 carbon atoms contained in the constituent material of the surface layer is C (mass%). ), A laminated film satisfying the following (Equation 1) to (Equation 3).
HDa <HDb ... (Equation 1),
Tb / T <0.5 ... (Equation 2),
25 ≤ C / Ta (mm ^-1 ) ≤ 100 ... (Equation 3).

[2] The methacrylic resin (A) is a methacrylic resin (X) which is a homopolymer of methyl methacrylate or a copolymer of methyl methacrylate and a (meth) acrylic acid ester, and an acrylic rubber (R). Including and
The laminated film of [1] in which the methacrylic resin (X) and / or the acrylic rubber (R) contains an acrylic acid alkyl ester unit having 6 to 12 carbon atoms.
[3] The acrylic rubber (R) is a laminated film of [2] which is a multilayer structure rubber particles (Y) or a block copolymer (Z).

[4] The thermoplastic resin (B) is a laminated film according to any one of [1] to [3] containing a polycarbonate resin.
[5] The laminated film according to any one of [1] to [4], further comprising a hard coat layer on the surface layer.
[6] A laminated molded product having a layer made of the laminated film according to any one of [1] to [5] on the surface of the adherend molded product.

[7] The method for producing a laminated film according to any one of [1] to [5], which comprises a step of coextruding the constituent material of the surface layer and the constituent material of the binder layer.
[8] Production of the laminated molded product according to [6], in which the laminated film is preformed at 130 ° C. or lower, and then film insert molding for molding the adherend molded product is performed in the presence of the preformed laminated film. Method.

According to the present invention, it is suitable for use in film insert molding, has good surface hardness, good shapeability during preformation, surface condition, and crack resistance, and has good crack resistance during trimming. A good laminated film can be obtained.

It is a schematic cross-sectional view of the laminated film of one Embodiment which concerns on this invention. It is a schematic cross-sectional view of the laminated molded body of one Embodiment which concerns on this invention.

[Laminated film]
The present invention relates to a laminated film suitable for use in film insert molding. The laminated film of the present invention has a surface layer containing one or more kinds of methacrylic resin (A) as a main component and a binder layer containing one or more kinds of thermoplastic resin (B) as a main component. The laminated film of the present invention may further have any one or more other layers, if necessary.
FIG. 1 shows a schematic cross-sectional view of a laminated film according to an embodiment of the present invention. In the figure, reference numeral 10 is a laminated film, reference numeral 11 is a surface layer, and reference numeral 12 is a binder layer.

In the laminated film of the present invention, the deflection temperature under load of the constituent material of the surface layer is HDa, the deflection temperature under load of the constituent material of the binder layer is HDb, the total thickness of the laminated film is T (mm), and the thickness of the surface layer is Ta (). mm) (where Ta is 0.05 to 0.35 mm), the thickness of the binder layer is Tb (mm), and the concentration of the acrylic acid alkyl ester unit having 6 to 12 carbon atoms contained in the constituent material of the surface layer is When C (mass%), the following (Equation 1) to (Equation 3) are satisfied.
HDa <HDb ... (Equation 1),
Tb / T <0.5 ... (Equation 2),
25 ≤ C / Ta (mm ^-1 ) ≤ 100 ... (Equation 3).

Unless otherwise specified in the present specification, "main component" is defined as a component of 80% by mass or more.
Generally, a planar molded product having a thickness of 5 to 250 μm is mainly classified as a “film”, and a planar molded product having a thickness of more than 250 μm is mainly classified as a “sheet”, which is not specified in this specification. As far as this is concerned, these are collectively referred to as "film".
Unless otherwise specified, the various parameters described in the present specification shall be measured by the method described in the section [Example] below.

The laminated film of the present invention can be preferably used for producing a laminated molded body using a film insert molding method. The laminated molded product has a layer made of a laminated film on the surface of at least a part of the adherend molded product. The form of the adherend is arbitrary, but the present invention can be preferably applied when the adherend has a three-dimensional shape. In this case, the laminated film is preformed by a vacuum forming method, a hot press molding method, etc., trimmed as necessary, and then film insert molding is performed in which the adherend is molded in the presence of the preformed protective film. By doing so, it is possible to manufacture a laminated molded body having an arbitrary three-dimensional shape.

(Surface layer)
The surface layer contains one or more methacrylic resins (A). The methacrylic resin (A) is a homopolymer or a copolymer containing one or more methacrylic acid ester monomer units. From the viewpoint of weather resistance, transparency, and surface hardness, a homopolymer of methyl methacrylate (MMA) or a copolymer of MMA and other monomers is preferable. Examples of the monomer other than MMA include acrylic acid esters such as methyl acrylate and ethyl acrylate; methacrylic acid esters other than MMA; unsaturated carboxylic acids; olefins; conjugated diene; aromatic vinyl compounds; and the like. ..

In the present invention, at least one methacrylic acid resin (A) contains a (co) polymer having an acrylic acid alkyl ester unit having 6 to 12 carbon atoms. Examples of the acrylic acid alkyl ester having 6 to 12 carbon atoms include n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, pentyl acrylate, hexyl acrylate, octyl acrylate, and 2-ethyl hexyl acrylate. , And cyclohexyl acrylate and the like.

<Methyl resin (X)>
The methacrylic resin (A) can include a homopolymer of MMA or a methacrylic resin (X) which is a copolymer of MMA and another (meth) acrylic acid ester. From the viewpoint of surface hardness, the methacrylic resin (X) contains 90 to 100% by mass of MMA units and, if necessary, 0 to 10% by mass of acrylic acid alkyl ester units having 4 to 5 carbon atoms (co). The polymer (Xa) is preferred. The MMA (co) polymer (Xa) may contain a methacrylic acid ester unit other than MMA and another (meth) acrylic acid ester unit such as an acrylic acid alkyl ester unit having 6 to 12 carbon atoms.
Although the steric regularity of the methacrylic resin (X) is generally atactic, a methacrylic resin having a high syndiotacticity may be used.

<Acrylic rubber (R)>
From the viewpoint of crack resistance when processing the laminated film, the methacrylic resin (A) preferably contains an acrylic rubber (R) in accordance with the methacrylic resin (X). In such an embodiment, the methacrylic resin (X) and / or the acrylic rubber (R) can contain acrylic acid alkyl ester units having 6 to 12 carbon atoms.

In one embodiment, the methacrylic resin (A) comprises an MMA (co) polymer (Xai) composed of 90 to 100% by mass of MMA units and 0 to 10% by mass of acrylic acid alkyl ester units having 4 to 5 carbon atoms, and carbon. Acrylic rubber (Ra) containing the number 6 to 12 acrylic acid alkyl ester units can be included.
The concentration of the acrylic acid alkyl ester unit having 6 to 12 carbon atoms in the acrylic rubber (Ra) with respect to the total mass of the constituent material of the surface layer may satisfy (Equation 3), preferably 2.5 to 25. It is mass%.
The content of the acrylic acid alkyl ester unit having 6 to 12 carbon atoms in the acrylic rubber (Ra) is preferably more than 5% by mass, more preferably 10% by mass or more, and particularly preferably 20% by mass or more. Is 90% by mass or less, more preferably 80% by mass or less.
The acrylic rubber (Ra) may contain (meth) acrylic acid ester units other than the MMA unit and the acrylic acid alkyl ester unit having 6 to 12 carbon atoms, and other units. The content of MMA units in the acrylic rubber (Ra) is preferably less than 90% by mass.

Examples of the acrylic rubber (R) include multilayer structure rubber particles (Y) and block copolymer (Z).

Examples of the multilayer rubber particles (Y) include acrylic multilayer rubber particles having one or more graft copolymer layers containing one or more acrylic acid alkyl ester copolymers. As the acrylic multilayer structure rubber particles, those disclosed in JP-A-2004-352837 can be used. The acrylic multilayer structure rubber particles can have a crosslinked polymer layer containing an acrylic acid alkyl ester unit having 6 to 12 carbon atoms.
The number of layers of the multi-layer structure rubber particles (Y) is not particularly limited, and may be two layers or three or more layers. Preferably, the multilayer structure rubber particles (Y) have three or more layers of core-shell structure particles including an innermost layer (y-1), one or more intermediate layers (y-2), and an outermost layer (y-3). Y-CS).

The constituent polymer of the innermost layer (y-1) contains an MMA unit and a graftable / or crosslinkable monomer unit, and may further contain one or more other units, if necessary. The content of MMA units in the constituent polymer of the innermost layer (y-1) is preferably 80 to 99.99% by mass, more preferably 85 to 99% by mass, and particularly preferably 90 to 98% by mass. The ratio of the innermost layer (y-1) in the three or more layers of core-shell structural particles (Y-CS) is preferably 0 to 15% by mass, more preferably 7 to 13% by mass. When the ratio of the innermost layer (y-1) is within such a range, the heat resistance of the surface layer can be enhanced.

The constituent polymer of the intermediate layer (y-2) contains an acrylic acid alkyl ester unit having 6 to 12 carbon atoms and a graftable / or crosslinkable monomer unit, and if necessary, one or more other types. Can include units. The content of the acrylic acid alkyl ester unit in the constituent polymer of the intermediate layer (y-2) is preferably 70 to 99.8% by mass, more preferably 75 to 90% by mass, and particularly preferably 78 to 86% by mass. Is. The proportion of the intermediate layer (y-2) in the three or more layers of core-shell structural particles (Y-CS) is preferably 40 to 60% by mass, more preferably 45 to 55% by mass. When the ratio of the intermediate layer (y-2) is within such a range, the surface hardness of the surface layer can be increased and the surface layer can be made difficult to crack.

The constituent polymer of the outermost layer (y-3) contains MMA units, and can further contain one or more other monomer units, if necessary. The content of MMA units in the constituent polymer of the outermost layer (y-3) is preferably 80 to 100% by mass, more preferably 85 to 100% by mass, and particularly preferably 90 to 100% by mass. The proportion of the outermost layer (y-3) in the three or more layers of core-shell structural particles (Y-CS) is preferably 35 to 50% by mass, more preferably 37 to 45% by mass. When the ratio of the outermost layer (y-3) is within such a range, the surface hardness of the surface layer can be increased.

The particle size of the multi-layered rubber particles (Y) is preferably 0.05 to 0.3 μm. The particle size can be measured by a known method such as electron microscope observation and dynamic light scattering measurement. Measurements by electron microscopy include, for example, selectively staining a specific layer of multi-layered rubber particles by electron staining and using a transmission electron microscope (TEM) or a scanning electron microscope (SEM) for multiple particles. This can be done by actually measuring the particle size and finding the average value. The dynamic light scattering method is a measurement method that utilizes the principle that the Brownian motion increases as the particle size increases.

The multi-layered rubber particles (Y) have a multi-layered structure rubber particle (Y) in order to suppress a decrease in handleability due to sticking between the multi-layered rubber particles (Y) and a decrease in impact resistance due to poor dispersion during melt-kneading. ) And particles (D) for dispersion can be used in the form of latex or powder. As the dispersion particles (D), for example, particles made of a polymer of one or more types of monomers mainly composed of MMA and having a smaller particle size than the multilayer structure rubber particles (Y) can be used.

The particle size of the dispersion particles (D) is preferably as small as possible from the viewpoint of improving dispersibility, and is preferably 40 to 120 nm, more preferably 50 to 100 nm from the viewpoint of production reproducibility by the emulsion polymerization method. The amount of the dispersion particles (D) added is preferably 10 to 50% by mass with respect to the total amount of the multilayer structure rubber particles (Y) and the dispersion particles (D) from the viewpoint of the effect of improving the dispersibility. It is preferably 20 to 40% by mass.

The block copolymer (Z) has one or more methacrylic acid ester polymer blocks (z1) and one or more acrylic acid alkyl ester polymer blocks (z2). In one embodiment, the acrylic acid alkyl ester polymer block (z2) can contain acrylic acid alkyl ester units having 6 to 12 carbon atoms.

The block copolymer (Z) preferably contains a total of 10 to 80% by mass, preferably 20 to 70% by mass of the methacrylic acid ester polymer block (z1), and a total of the acrylic acid alkyl ester polymer block (z2). It can be contained in a proportion of 90 to 20% by mass, preferably 30 to 80% by mass. By using such a block copolymer (Z), it is possible to enhance the whitening resistance of the surface layer during film insert molding.

As the form of the block copolymer (Z), a diblock copolymer and a triblock in which the methacrylic acid ester polymer block (z1) is bonded to one end or both ends of the acrylic acid alkyl ester polymer block (z2). Examples include block polymers.

The methacrylic acid ester polymer block (z1) is a block mainly containing a methacrylic acid ester unit. The content of the methacrylic acid ester unit in the methacrylic acid ester polymer block (z1) is preferably 80% by mass or more, more preferably 90% by mass or more, particularly preferably 95% by mass or more, and most preferably 98% by mass or more. It may be 100% by mass. As the methacrylic acid ester, MMA is preferable from the viewpoint of improving the transparency and heat resistance of the surface layer.

The stereoregularity of the methacrylic acid ester polymer block (z1) is defined by the syndiotacticity (rr) (hereinafter, also simply referred to as “rr ratio”) in triplet representation. From the viewpoint of increasing the glass transition temperature (Tg) of the surface layer and enhancing the heat resistance, the rr ratio is preferably 60% or more, more preferably 65% or more, particularly preferably 70% or more, and most preferably 75% or more. ..

The acrylic acid alkyl ester polymer block (z2) is a block mainly containing an acrylic acid alkyl ester unit. At least one acrylic acid alkyl ester polymer block (z2) in the block copolymer (Z) can contain an acrylic acid alkyl ester unit having 6 to 12 carbon atoms. From the viewpoint of cost, low temperature characteristics, and transparency, (z2) is a homopolymer block of n-butyl acrylate or a copolymer block of an acrylic acid alkyl ester having 6 to 12 carbon atoms and benzyl acrylate. Is preferable.
The content of the acrylic acid alkyl ester unit in the acrylic acid alkyl ester polymer block (z2) is preferably 50% by mass or more, more preferably 70% by mass or more, particularly preferably 80% by mass or more, and most preferably 90% by mass. % Or more, and may be 100% by mass.

The block copolymer (Z) may have a functional group such as a hydroxyl group, a carboxy group, an acid anhydride group, and an amino group in the molecular chain or at the end of the molecular chain, if necessary.
The melt viscosity of the block copolymer (Z) at 220 ° C. and a shear rate of 122 / sec is preferably 75 to 1500 Pa · s.
The block copolymer (Z) can be produced by a known method, and examples thereof include a method of living-polymerizing the monomers constituting each polymer block.

<Other methacrylic resins>
The methacrylic resin (A) can include other methacrylic resins other than the methacrylic resin (X) and the acrylic rubber (R). Examples of other methacrylic resins include methacrylic copolymers (S) containing aromatic vinyl compound units, acid anhydride units, methacrylic acid ester units, and optionally other units.
Aromatic vinyl compounds include styrene; nuclear alkyl substituted styrenes such as 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-ethylstyrene, and 4-tert-butylstyrene; α-methylstyrene and 4-. Α-alkyl substituted styrene such as methyl-α-methylstyrene; From the viewpoint of availability, styrene is preferable.
Examples of the acid anhydride include maleic anhydride (MAH), citraconic anhydride, dimethyl maleic anhydride and the like. Maleic anhydride (MAH) is preferred from the standpoint of availability.
Examples of the methacrylic copolymer (S) include styrene (St) -maleic anhydride (MAH) -MMA copolymer (SMM resin) and the like. The SMM resin can contain, for example, St unit of 50 to 85% by mass, MAH unit of 15 to 40% by mass, and MMA unit of 10 to 40% by mass. Examples of the commercially available SMM resin include "Registry" manufactured by Denka Corporation.

(Binder layer)
The binder layer contains one or more thermoplastic resins (B). In the laminated film of the present invention, the deflection temperature HDb under load of the constituent material of the binder layer is higher than the deflection temperature HDa under load of the constituent material of the surface layer. The thermoplastic resin (B) may be a material that satisfies these conditions and can adhere the adherend to the surface layer well, and is a polycarbonate resin from the viewpoint of deflection temperature under load, transparency, and impact resistance. (PC) or the like is preferable. The deflection temperature HDb under load of the polycarbonate resin (PC) is about 135 ° C.

The polycarbonate resin (PC) is a polymer obtained by reacting a polyfunctional hydroxy compound with a carbonic acid ester-forming compound. Examples of the polyfunctional hydroxy compound include 4,4'-dihydroxybiphenyls which may have a substituent and bis (hydroxyphenyl) alkanes which may have a substituent. Of these, 2,2-bis (4-hydroxyphenyl) propane is preferable. Examples of the carbonic acid ester-forming compound include various dihalogenated carbonyls such as phosgene, halohomates such as chlorohomates, and bisaryl carbonates. The amounts of the polyfunctional hydroxy compound and the carbonic acid ester-forming compound may be appropriately adjusted in consideration of the stoichiometric ratio (equivalent) of the reaction.

The polycarbonate-based resin (PC) may contain a unit having a polyester structure, a polyurethane structure, a polyether structure, or a polysiloxane structure in addition to the polycarbonate unit.

From the viewpoint of improving crack resistance during preformation and trimming, the weight average molecular weight (Mw) of the polycarbonate resin (PC) is preferably 30,000 or more, more preferably 45,000 or more.
From the viewpoint of ease of production by extrusion molding, the viscosity average molecular weight of the polycarbonate resin (PC) is preferably 13000 to 30,000. From the same viewpoint, the melt viscosity of the polycarbonate resin (PC) at 250 ° C. and 100 sec ^-1 is preferably 13000 to 60,000 poise. The molecular weight can be adjusted by adjusting the amount of the terminal inhibitor and / or the branching agent.

(Optional ingredient)
<Colorant>
The surface layer and / or the binder layer can contain colorants such as dyes and pigments, if necessary.
Dyes include anthracinones, azos, anthrapyridones, perylenes, anthracenes, perinones, indanthrons, quinacridones, xanthenes, thioxanthenes, oxazines, oxazolines, indigoids, thioindigoids. , Quinophthalones, Naphthalimides, Cyanines, Metins, Pyrazolones, lactones, Kumarins, Bis-benzoxazolylthiophenes, Naphthalenetetracarboxylic acids, Phthalocyanines, Triarylmethanes, Aminoketones, Bis ( Styryl) Biphenyls, azines, rhodamines, derivatives thereof, combinations thereof and the like can be mentioned. From the viewpoint of heat resistance and weather resistance, perinones, perylenes, azos, methines, quinolines and the like are preferable, and anthraquinones and the like are more preferable.
Organic pigments include azo, azomethine, polyazo, phthalocyanine, quinacridone, anthraquinone, indigo, thioindigo, quinophthalone, benzimidazolone, isoindoline, isoindolinone, and diacet. Examples include acetarylides. Inorganic pigments include carbon black, titanium oxide, zinc oxide, zinc oxide, lithopon, iron oxide, aluminum oxide, silicon dioxide, kaolinite, montmorillonite, talc, barium sulfate, calcium carbonate, silica, alumina, cadmium red, and red iron oxide. Molybdenum Red, Chrome Vermillion, Molybdate Orange, Yellow Lead, Chrome Yellow, Cadmium Yellow, Yellow Iron Oxide, Titanium Yellow, Chromium Oxide, Pyridian, Cobalt Green, Titanium Cobalt Green, Cobalt Chrome Green, Ultramarine Blue, Ultramarine Blue, Navy Blue , Cobalt Blue, Cerulean Blue, Manganese Violet, Cobalt Violet, Mica and the like.

<Other additives>
The surface layer and / or the binder layer can contain one or more additives, if desired. Examples of the additive include antioxidants, stabilizers, ultraviolet absorbers, lubricants, processing aids, antistatic agents, impact resistant agents, foaming agents, fillers, matting agents and the like.

(Thickness of each layer, total thickness of laminated film)
The thickness of each layer and the total thickness of the laminated film are appropriately designed according to the application of the laminated molded product and the required performance for the laminated film.
From the viewpoint of improving the surface hardness of the laminated film, the shapeability at the time of preformation, the crack resistance at the time of trimming, and the handleability, the thickness Ta of the surface layer is 0.05 to 0.35 mm, preferably 0. It is 05 to 0.3 mm, more preferably 0.06 to 0.25 mm, and particularly preferably 0.07 to 0.2 mm.
The thickness Tb of the binder layer is preferably 0.01 to 0 from the viewpoint of improving the shapeability at the time of preformation, the crack resistance at the time of trimming, the handling property, and the adhesion with the injection resin at the time of film insert molding. It is .2 mm, more preferably 0.02 to 0.15 mm, and particularly preferably 0.03 to 0.1 mm.
The total thickness T of the laminated film is preferably 0.15 to 0.5 mm, from the viewpoint of improving the shapeability at the time of preformation, the crack resistance at the time of trimming, the handling property, and the surface hardness of the laminated molded product. It is preferably 0.07 to 0.4 mm, and particularly preferably 0.09 to 0.35 mm.

((Equation 1): HDa <HDb)
In the laminated film of the present invention, the material of each layer is selected so that the deflection temperature HDb of the constituent material of the binder layer is higher than the deflection temperature HDa of the constituent material of the surface layer.

((Equation 2): Tb / T <0.5)
Tb / T is the ratio of the thickness Tb of the binder layer to the total thickness T of the laminated film. In the present invention, Tb / T is less than 0.5, preferably 0.4 or less, and more preferably 0.3 or less.
In the laminated film of the present invention, the deflection temperature HDb under load of the constituent material of the binder layer is higher than the deflection temperature HDa under load of the constituent material of the surface layer, and a polycarbonate resin (PC) or the like is preferable as the constituent resin of the binder layer. Polycarbonate-based resin (PC) is a resin having high heat resistance. In this case, in the prior art, if the temperature at the time of preformation is too low for the polycarbonate resin (PC), the polycarbonate resin may not be sufficiently softened, and the shapeability or the interlayer adhesion of the film may be deteriorated. If the temperature at the time of preform is raised in accordance with the polycarbonate resin (PC), the surface roughness of the surface layer containing the methacrylic resin (A) may increase due to heat.
If the proportion of the binder layer having high heat resistance is relatively small and Tb / T <0.5, the preform is performed at a temperature that does not deteriorate the surface roughness of the surface layer regardless of the constituent resin of the binder layer. Also, the preform can be carried out satisfactorily. In addition, since the ratio of the surface layer to the total thickness is relatively high, the concentration of the UV absorber added to the surface layer as needed can be reduced, and the UV absorber can be used in actual use. It is possible to suppress bleeding out to the surface on the surface layer side.
When Tb / T ≧ 0.5, the ratio of the binder layer having high heat resistance is large, and the molding temperature suitable for the surface layer containing the methacrylic resin (A) at the time of preform (molding that does not deteriorate the surface roughness of the surface layer). With temperature), it is difficult to shape the desired shape well. Even if Tb / T ≧ 0.5, the surface layer can be shaped to a desired shape by adjusting the temperature at the time of preform to a molding temperature suitable for the binder layer containing the thermoplastic resin (B). There is a risk that the surface roughness of the surface will deteriorate.

((Equation 3): 25 ≦ C / Ta ≦ 100)
C / Ta is the ratio of the concentration C of the acrylic acid alkyl ester unit having 6 to 12 carbon atoms contained in the constituent material of the surface layer to the thickness Ta of the surface layer. In the present invention, C / Ta is 25 to 100 mm ^-1 , preferably 30 to 90 mm ^-1 .
When C / Ta <25 mm ^-1 , cracks may occur in the laminated film at the time of preforming or trimming, and when C / Ta> 100 mm ^-1 , the surface hardness of the laminated film may decrease. When 25 ≦ C / Ta (mm ^-1 ) ≦ 100, the elongation of the laminated film is improved, and cracks in the laminated film during preform and trimming can be suppressed without lowering the surface hardness.

(Any layer)
The laminated film of the present invention may have any layer other than the surface layer and the binder layer, if necessary. Optional layers include a hardcourt layer, an antifouling layer, an antireflection layer and the like.
Since the surface layer of the laminated film of the present invention contains the methacrylic resin (A), it has good surface hardness and can have good scratch resistance. Further, in order to increase the surface hardness and improve the scratch resistance, the laminated film of the present invention can have a hard coat layer (scratch resistant layer) on the surface layer. Examples of the hard coat layer include a cured film, which can be formed by a known method (see, for example, JP-A-2004-299199 and JP-A-2006-103169). The thickness of the hardcoat layer is preferably 2 to 30 μm, more preferably 5 to 20 μm, from the viewpoint of the effect of improving scratch resistance and the crack resistance during preform / trimming.

In the laminated film of the present invention, the surface layer contains the methacrylic resin (A), and the ratio of the thickness Tb of the binder layer to the total thickness T of the laminated film is less than 0.5 (Tb / T <0.5). , Has good surface hardness, has good scratch resistance, and has excellent toughness.
Since the laminated film of the present invention has Tb / T <0.5, it can be preformed satisfactorily even if the preform is performed at a temperature that does not deteriorate the surface roughness of the surface layer regardless of the constituent resin of the binder layer. Can be carried out.
In the laminated film of the present invention, the ratio of the concentration C of the acrylic acid alkyl ester unit having 6 to 12 carbon atoms contained in the constituent material of the surface layer to the thickness Ta of the surface layer is 25 to 100 (25 ≦ C / Ta ≦ 100). Therefore, it is possible to suppress cracks in the laminated film during preform and trimming without lowering the surface hardness of the laminated film.
As described above, according to the present invention, it is suitable for use in film insert molding, has good surface hardness, has good shapeability at the time of preformation, surface condition, and crack resistance, and is trimmed. It is possible to provide a laminated film having good crack resistance at the time.

[Manufacturing method of laminated film]
The laminated film of the present invention can be produced by a known film molding method. The extrusion molding method is preferable from the viewpoint of production efficiency and interlayer adhesion of each layer. In the case of the extrusion molding method, the resin for the surface layer and the resin for the binder layer, which have been melt-kneaded using different extruders, are extruded into films from different extrusion dies (film forming dies such as T-dies) and then bonded. The surface layer resin and the binder layer resin that have been melt-kneaded using different extruders may be co-extruded from a common extrusion die.
Examples of the coextrusion die method include a multi-manifold die method and a field block method. In the feed block method, the melted surface layer resin and the melted binder layer resin are laminated in the feed block, and then guided by a film forming die such as a T die to be formed into a film and extruded. .. In the multi-manifold method, the molten surface layer resin and the melted binder layer resin are laminated in the multi-manifold die, formed into a film, and extruded. In either method, the molten laminated film extruded from the film forming die is pressurized and cooled through the gaps between a plurality of cooling rolls adjacent to each other, and the laminated film that has been sufficiently cooled and solidified is a take-up roll. Will be taken over by. From the viewpoint of the uniformity of the thickness of each layer, a multi-manifold die is preferable.

In the above method, impurities and the like of the molten resin for each layer can be removed by using a polymer filter, if necessary. Examples of the polymer filter include a leaf type polymer filter and a pleated type polymer filter, and a pleated type polymer filter is preferable. The opening of the polymer filter is not particularly limited, and is preferably 5 to 40 μm.

[Laminate molded body]
The laminated molded product of the present invention has a layer made of the above-mentioned laminated film of the present invention on the surface of at least a part of the adherend molded product.
FIG. 2 shows a schematic cross-sectional view of a laminated molded article according to an embodiment of the present invention. The same components as in FIG. 1 are designated by the same reference numerals. In the figure, reference numeral 20 is a laminated molded body, and reference numeral 21 is an adherend molded body. The laminated molded body 20 of the present embodiment has a laminated structure of a surface layer 11 / a binder layer 12 / an adherend molded body 21. The binder layer 12 of the laminated film 10 has a function of satisfactorily adhering the adherend 21 and the surface layer 11. The adherend molded body 21 is manufactured by performing film insert molding for molding the adherend molded body 21 in the presence of a laminated film 10 preformed into a three-dimensional shape, if necessary.

(Adhesion molded body)
The form of the adherend is not particularly limited, and examples thereof include a plate material (flat plate, curved plate, etc.), a three-dimensional object, and a sheet (or film). The present invention can be preferably applied when the adherend has a three-dimensional shape.
The material of the adherend may be any material as long as the laminated film of the present invention can be laminated by the film insert molding method. For example, acrylic resin, polyester resin, polystyrene resin, polyolefin resin such as polypropylene, ABS resin, polycarbonate resin, phenol resin, vinyl chloride resin, cellulose resin, rubber and the like can be mentioned. Polycarbonate-based resins are preferable from the viewpoints of transparency, impact resistance, and heat resistance.

Hereinafter, an example of a method for manufacturing a three-dimensional laminated molded body will be described.
A laminated film having a laminated structure of a surface layer / a binder layer produced by the above method is preformed into a desired three-dimensional shape by a vacuum forming method, a hot press forming method, or the like.
As described above, in the present invention, the preform can be satisfactorily carried out even if the preform is carried out at a temperature that does not deteriorate the surface roughness of the surface layer, regardless of the constituent resin of the binder layer. The upper limit of the preform temperature is set to a temperature at which the surface roughness of the surface layer does not deteriorate, and is preferably 130 ° C. or lower. The lower limit of the preform temperature is preferably 100 ° C. or higher as long as the preform can be carried out satisfactorily.
After preform, trim the unnecessary part by punching if necessary.
Next, the preformed laminated film is set in an injection molding die, and a resin is injected into the die from the binder layer side to perform injection molding of the adherend molded body. The temperature of the injection resin depends on the melt viscosity of the resin used, but is usually 150 to 300 ° C, preferably 180 to 280 ° C, and particularly preferably 200 to 260 ° C.

The laminated molded article of the present invention is manufactured by using the above-mentioned laminated film of the present invention. Therefore, according to the present invention, it is possible to provide a laminated molded product having good surface hardness, formability, and surface condition and reduced cracks.

[Use]
The laminated film of the present invention is suitable for surface protection or decoration of various molded products, and is suitable for applications requiring scratch resistance or design. The laminated film and laminated molded body of the present invention are signboard parts such as advertising towers, stand signs, sleeve signs, column signs, and roof signs; display parts such as showcases, dividers, and store displays; fluorescent lamp covers, moods, etc. Lighting components such as lighting covers, lamp shades, light ceilings, light walls, and chandeliers; Interior components such as furniture, pendants, and mirrors; doors, dome, safety window glass, partitions, staircase wainscots, balcony wainscots, and leisure buildings. Building parts such as roofs of objects; aircraft windshields, pilot visors, motorcycles, motor boat windshields, bus shading plates, automobile side visors, rear visors, head wings, headlight covers, automobile interior parts, and automobile exterior parts (bumpers and Transport machine related parts such as molds); Sound image plates and acoustic parts such as stereo covers; Electronic equipment parts such as TV protective masks, vending machines, mobile phones, and personal computers; Baby products such as incubators; Roentgen Medical equipment parts such as parts; Equipment-related parts such as machine covers, instrument covers, experimental equipment, rulers, dials, and observation windows; Traffic-related parts such as road signs, information boards, curved mirrors, and soundproof walls; Greenhouses; Bathroom parts such as large water tanks, box water tanks, bathtubs, and sanitary supplies; watch panels; office supplies such as desk mats; game parts and toys; decorative films and surface protection films for various parts such as face protection masks during welding. It is suitably used for wallpaper, marking film and the like.

Examples and comparative examples according to the present invention will be described.
[Evaluation items and evaluation methods]
The evaluation items and evaluation methods are as follows.
(Deflection temperature under load)
According to JIS-K 7191, the deflection temperature under load of the resin was measured.
(Pencil hardness)
A 30 mm × 30 mm test piece was cut out from the laminated film obtained by coextrusion molding. The test piece was set in a pencil hardness tester (pencil scratch coating film hardness tester manufactured by Toyo Seiki Seisakusho Co., Ltd.), and the pencil hardness on the surface layer side was measured in accordance with JIS-K5600-5-4.

(Formability at the time of preformation, surface condition, crack resistance)
A laminated film (300 mm × 210 mm) obtained by coextrusion molding was vacuum formed using a vacuum pressure forming machine (manufactured by Fuse Vacuum Co., Ltd., NGF type). The laminated film was set so that the binder layer side faced the rectangular parallelepiped mold having a size of 38 mm × 38 mm × height 7 mm, and vacuum forming was performed when the surface temperature of the laminated film reached 125 ° C. This vacuum forming was performed on five laminated films, and the following evaluations were carried out.

<Excipient>
The corners of the rectangular parallelepiped of the five laminated films after vacuum forming were visually observed, and the shapeability was evaluated according to the following criteria.
A (good): The shaping of the corners was good in all the laminated films.
B (possible): There was one laminated film in which the shaping was not perfect and the corners were rounded.
C (defective): The shaping was not perfect, and there were two or more laminated films with rounded corners.

<Surface condition>
The five laminated films after vacuum forming were visually observed from the surface layer side, and the surface condition was evaluated according to the following criteria.
A (Good): No change in surface is observed in all the laminated films as compared with the laminated film before vacuum forming.
B (possible): There was one laminated film in which the surface roughness was increased / or defects such as air bubbles were observed as compared with the laminated film before vacuum forming.
C (defective): There were two or more laminated films having a larger surface roughness / or defects such as air bubbles as compared with the laminated film before vacuum forming.

<Crack resistance>
The five laminated films after vacuum forming were visually observed, and the crack resistance was evaluated according to the following criteria.
A (good): No cracks occurred in all the laminated films.
B (OK): There was one laminated film with cracks.
C (defective): There were two or more laminated films in which cracks were generated.

(Crack resistance during trimming)
Each of the five laminated films after vacuum forming was trimmed at a temperature of 23 ° C. using a punching device (manufactured by Dumbbell Co., Ltd., SDL-200). A Thomson blade (manufactured by Dumbbell Co., Ltd., 38 mm × 38 mm) was used as the punching blade, and the punching blade was brought into contact with the surface layer side of the preformed portion. A cutting mat was used as an underlay for trimming. The trimmed part was visually observed and the crack resistance was evaluated according to the following criteria.
A (good): No cracks occurred in all the test pieces.
B (OK): There was one test piece with cracks.
C (defective): There were two or more test pieces with cracks.

[material]
The materials used are as follows.
(Thermoplastic resin (A))
<Methyl resin (X)>
(X-1) Copolymer of methyl methacrylate (MMA) and methyl acrylate (MA) (content of methyl acrylate unit: 2.5% by mass, viscosity average degree of polymerization: 1170, deflection temperature under load: 101 ℃).

<Multilayer structure rubber particles (Y)>
(Y-1) A multi-layered rubber particle (particle diameter: 0.23 μm) having a three-layer structure composed of an innermost layer (y-1), an intermediate layer (y-2), and an outermost layer (y-3). Composition of innermost layer (y-1): 32.91 parts by mass of MMA unit, 2.09 parts by mass of methyl acrylate (MA) unit, and 0.07 parts by mass of allyl methacrylate, which is a crosslinkable monomer unit. Composition of intermediate layer (y-2): 37.00 parts by mass of n-butyl acrylate unit, 8.00 parts by mass of styrene unit, and 0.90 parts by mass of allyl methacrylate, which is a crosslinkable monomer unit. Composition of outermost layer (y-3): 18.80 parts by mass of methyl methacrylate (MMA) unit and 1.20 parts by mass of methyl acrylate (MA) unit.

<Particles for dispersion (D)>
(D-1) Copolymer particles of methyl methacrylate (MMA) and methyl acrylate (MA) (content of methyl acrylate unit: 10.0% by mass, particle size: 0.11 μm).

<Multilayer structure rubber particle-containing powder (YP)>
(YP-1)
The latex containing the multilayer rubber particles (Y-1) and the latex containing the dispersion particles (D-1) were mixed at a solid content mass ratio of 67:33. The resulting mixed latex was frozen at −30 ° C. for 4 hours. This frozen latex is poured into twice the amount of frozen latex in warm water at 90 ° C. to dissolve it into a slurry, held at 90 ° C. for 20 minutes for dehydration, dried at 80 ° C., and has a multi-layered rubber particle (Y-). A powder (YP-1) containing 1) was obtained.

<Block Copolymer (Z)>
(Z-1) Monopolymer block of methyl methacrylate (MMA) [z1-1], homopolymer block of n-butyl acrylate [z2-1], and homopolymer block of methyl methacrylate (MMA). Triblock copolymer composed of [z1-2], [z1-1]: [z2-1]: [z1-2] (mass ratio) = 1: 3: 2, weight average molecular weight (Mw) = 60, 000.

<Styrene-maleic anhydride-MMA copolymer (SMM resin)>
(S-1) "Registry R-200" manufactured by Denka Corporation.

(Thermoplastic resin (B))
<Polycarbonate resin (PC)>
(PC-1) "300 series" manufactured by Sumika Stylon Polycarbonate, deflection temperature under load: 135 ° C.

[Production Example 1] [Preparation of methacrylic resin (A-1) for surface layer]
Using a single-screw extruder, 70 parts by mass of the methacrylic resin (X-1) and 30 parts by mass of the multi-layered rubber particle-containing powder (YP-1) are melt-kneaded to form a methacrylic resin (A) for the surface layer. -1) (Deflection temperature under load HDa = 86 ° C.) was obtained. The composition and HDa are shown in Table 1.

[Production Examples 2 to 6] [Preparation of methacrylic resins (A-2) to (A-6) for surface layer]
The methacrylic resins (A-2) to (A-6) for the surface layer were obtained in the same manner as in Production Example 1 except that the composition was changed to that shown in Table 1. The composition and HDa are shown in Table 1.

(Example 1)
The polycarbonate resin (PC-1) to be the binder layer was melt-extruded using a 30 mmφ vent type single-screw extruder at a discharge rate of 5 kg / hr. At the same time, the methacrylic resin (A-1) to be the surface layer was melt-extruded at 20 kg / hr using a 50 mmφ vent type single-screw extruder. Using a multi-manifold die with a width of 400 mm, the above two types of molten resins were laminated and extruded into a film at a temperature of 255 ° C. The molten laminated film extruded from the die was niped using a plurality of metal mirror surface rolls (surface temperature: 95 ° C.) and taken up at a speed of 4.0 m / min. In this way, a laminated film having a surface layer thickness Ta = 0.2 mm, a binder layer thickness Tb = 0.05 mm, and a total thickness T = 0.25 mm was obtained.
The obtained laminated film was vacuum formed (preform) under the condition of a sheet temperature of 125 ° C. by the method described in the evaluation of "formability at the time of preformation, surface condition, crack resistance". .. The pencil hardness of the laminated film, the shapeability at the time of preformation, the surface condition, the crack resistance, and the crack resistance at the time of trimming were evaluated. The main manufacturing conditions and evaluation results are shown in Tables 2 and 3.

(Example 2-7, Comparative Example 1-13)
The laminated film was formed and preformed in the same manner as in Example 1 except that the composition and thickness of each layer were changed as shown in Table 2, and evaluated. The main manufacturing conditions and evaluation results are shown in Tables 2 and 3.

[Summary of evaluation results]
In Examples 1 to 7 for producing a laminated film having a surface layer made of a methacrylic resin (A) and a binder layer made of a thermoplastic resin (B) and satisfying (Formula 1) to (Formula 3). However, the evaluation results of the pencil hardness of the laminated film, the shapeability at the time of preforming, the surface condition, the crack resistance, and the crack resistance at the time of trimming were good.

Comparative Examples 1 to 3 for producing a laminated film having Tb / T ≧ 0.5 and C / Ta> 100 mm ^-1 and not satisfying (Equation 2) and (Equation 3), and Tb / T ≧ 0.5. In Comparative Examples 4 to 6 in which the laminated films that did not satisfy the presence (Equation 2) were produced, the evaluation result of the shapeability at the time of preformation was poor.

In Comparative Examples 7 and 8 in which a laminated film having Tb / T <0.5 and satisfying (Equation 2) but not satisfying C / Ta <25 mm ^-1 (Equation 3) was produced, at the time of preform and The evaluation result of crack resistance at the time of trimming was poor.
Comparison in which Tb / T <0.5 and (Equation 2) is satisfied, but C / Ta <25 mm ^-1 and (Equation 3) is not satisfied and the total thickness T of the laminated film is increased to 0.5 mm. In Example 9, the evaluation result of the formability at the time of preform was poor.
Comparison in which Tb / T <0.5 and (Equation 2) is satisfied, but C / Ta <25 mm ^-1 and (Equation 3) is not satisfied and the total thickness T of the laminated film is increased to 1.0 mm. In Example 10, the evaluation result of the shapeability at the time of preform was poor as in Comparative Example 9, and the evaluation result of the crack resistance at the time of trimming was poor.
In Comparative Examples 11 to 13 in which the laminated films having Tb / T <0.5 and satisfying (Equation 2) but C / Ta> 100 mm ^-1 and not satisfying (Equation 3) were produced, the surface of the laminated film was obtained. The evaluation result of hardness was poor.

(Reference example 1)
The film formation, preform, and evaluation of the laminated film were carried out in the same manner as in Example 1 except that the sheet temperature at the time of preform was changed to 145 ° C. The evaluation results of formability and crack resistance were both A evaluations. However, since the sheet temperature was too high for the methacrylic resin, a bubble-like defect occurred on the surface layer side, and the evaluation result of the surface state was C evaluation. The preform temperature is preferably 130 ° C. or lower.

(Reference example 2)
The film formation, preform, and evaluation of the laminated film were carried out in the same manner as in Comparative Example 1 except that the sheet temperature at the time of preform was changed to 145 ° C. Since the sheet temperature approached the proper molding temperature of the thermoplastic resin (B), the evaluation results of the shapeability and the crack resistance were both improved to the A evaluation. However, since the sheet temperature was too high for the methacrylic resin, a bubble-like defect occurred on the surface layer side, and the evaluation result of the surface state was C evaluation. The preform temperature is preferably 130 ° C. or lower.

The present invention is not limited to the above embodiments and examples, and the design can be appropriately changed as long as the gist of the present invention is not deviated. The present invention includes all embodiments in which the various embodiments described in the above embodiments and examples are arbitrarily combined.

This application claims priority on the basis of Japanese application Japanese Patent Application No. 2017-107574 filed on May 31, 2017, and incorporates all of its disclosures herein.

10 Laminated film 11 Surface layer 12 Binder layer 20 Laminated molded body 21 Adhesive molded body

Claims (8)

A laminated film including a surface layer containing a methacrylic resin (A) and a binder layer containing a thermoplastic resin (B).
The deflection temperature under load of the constituent material of the surface layer is HDa, the deflection temperature under load of the constituent material of the binder layer is HDb, the total thickness of the laminated film is T (mm), and the thickness of the surface layer is Ta (however, Ta is). The thickness of the binder layer is Tb (mm) (where Tb is 0.01 to 0.2 mm) , and the number of carbon atoms contained in the constituent material of the surface layer is 6 to 0.35 mm. A laminated film satisfying the following (formula 1) , (formula 2A), and (formula 3A) when the concentration of the acrylic acid alkyl ester unit of 12 is C (mass%).
HDa <HDb ... (Equation 1),
0.1 ≤ Tb / T ≤ 0.3 ... (Equation 2 A ),
30 ≤ C / Ta (mm ^-1 ) ≤ 90 ... (Equation 3 A ). The methacrylic resin (A) contains a methacrylic resin (X) which is a homopolymer of methyl methacrylate or a copolymer of methyl methacrylate and a (meth) acrylic acid ester, and an acrylic rubber (R). ,
The laminated film according to claim 1, wherein the methacrylic resin (X) and / or the acrylic rubber (R) contains an acrylic acid alkyl ester unit having 6 to 12 carbon atoms. The laminated film according to claim 2, wherein the acrylic rubber (R) is a multilayer structure rubber particles (Y) . The laminated film according to any one of claims 1 to 3, wherein the thermoplastic resin (B) contains a polycarbonate resin. The laminated film according to any one of claims 1 to 4, further comprising a hard coat layer on the surface layer. A laminated molded product having a layer made of the laminated film according to any one of claims 1 to 5 on the surface of the adherend molded product. The method for producing a laminated film according to any one of claims 1 to 5, which comprises a step of coextruding the constituent material of the surface layer and the constituent material of the binder layer. The method for manufacturing a laminated molded product according to claim 6, wherein the laminated film is preformed at 130 ° C. or lower, and then film insert molding for molding the adherend molded product is performed in the presence of the preformed laminated film. ..

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