JP7307398B2 - laminated film - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention can be suitably used for a manufacturing method in which metal or resin parts such as outer panels of vehicles such as automobiles are coated with a coating substitute film instead of being painted, and has good adhesion to metals and resins, automobiles, etc. The present invention relates to a laminated film exhibiting an excellent appearance design required for outer panels and the like.

2. Description of the Related Art Conventionally, spray painting has generally been used to improve the design of vehicle exterior parts (for example, resin moldings such as fenders, bumpers, bonnets, wheel caps, etc.). However, in recent years, in the painting process including such spray painting, repeated painting and drying require a large amount of equipment and space, which reduces productivity. A method for improving the appearance of the product by laminating a decorative film (hereinafter referred to as a coating substitute film) to the exterior parts has been studied.

For example, as shown in FIG. 3, this type of conventional paint substitute film is configured by sequentially laminating a clear layer 4, a colored layer 31, and an adhesive layer 5 (see, for example, Patent Documents 1 and 2). ).

Here, the clear layer 4 is formed using a highly transparent resin material such as polyurethane, acrylic resin, polyester resin, silicon resin, PVDF (polyvinyl dene fluoride), or a mixture thereof, and protects the colored layer 31, It has functions such as polishing. Further, the colored layer 31 is formed by blending a metallic pigment into substantially the same resin material as the clear layer 4, thereby giving the colored layer 31 a metallic appearance similar to spray painting. Further, the adhesive layer 5 adheres the coating substitute film to the surface of the exterior parts of the automobile or the like by chemical bonding.

When the paint substitute film is adhered to the exterior parts or the like, the paint substitute film is heated in advance by irradiation with an infrared lamp or the like, and then the paint substitute film is formed into the surface shape of the exterior parts by in-mold molding, vacuum molding, or the like. They are molded together and bonded to the surface of the exterior component by means of the adhesive layer 5. - 特許庁Here, when the coating substitute film is laminated, the coating substitute film is stretched according to the contours of the mold and exterior parts while maintaining the layer structure shown in FIG. combined. However, when laminating a complex shape such as an exterior part of an automobile, etc., the coating substitute film 1 is partially stretched greatly at a curved surface portion, etc. , the following problems arise.

That is, when laminating the coating substitute film to exterior parts, etc., if the coating film is stretched and laminated via an adhesive, the bonding strength between the base material and the coating substitute film is locally strong and weak. occurs. As a countermeasure for this problem, it is effective to select an adhesive that has excellent chemical adhesion to the base material to be laminated, but there are some parts made of resin (resin parts) for the exterior parts of the vehicle. For example, there are members made of metal (metal members), and it is virtually impossible to select an adhesive that exhibits excellent adhesion to any member.

On the other hand, a heat-sealable film has been proposed as a film to be physically adhered to a metal foil or metal plate (see Patent Document 3, for example). The heat-sealable film proposed here is a film that bonds a plastic film and a metal foil without using an adhesive in a plastic film substrate laminated with a metal such as copper, which is used for a flexible printed circuit board or the like. . Specifically, a polyester substrate layer having a refractive index in the thickness direction of "1.500 or more" with little orientation in the plane direction and a heat seal layer with a thickness of 4 to 40 μm made of a polymer with a number average molecular weight of 15000 or more in contact with this. By using, delamination in the base material layer is suppressed and the decrease in adhesive strength is reduced.

However, when this technology is applied as a paint substitute film, it is not possible to obtain good image sharpness in terms of exterior appearance, which is particularly critically evaluated for exterior parts of vehicles. The inventors' examination revealed for the first time that the adhesion between the substitute films was not sufficient.

JP-A-63-123469 JP-A-9-183136 JP 2006-1114 A

An object of the present invention is to provide a laminated film that can exhibit excellent adhesive strength to metals and resins and that can exhibit excellent image sharpness as an external appearance required for vehicle exterior parts. be.

In order to achieve the above object, the present inventors have studied whether it is possible to laminate a paint substitute film without relying on an adhesive. It has been found that an excellent appearance is exhibited while ensuring the
Thus, according to the present invention, the following (1) to (14) are provided.

(1) A layer consisting of a layer B mainly made of crystalline polyester and having a refractive index in the thickness direction of less than 1.500 and a layer A having a thickness of 5 μm or more mainly made of polyester having an intrinsic viscosity of 0.60 or more. A laminated film, wherein the polyesters of the layers A and B have a melting point satisfying the following formula (1).
(TmB−TmA)≧20° C. (1)
(However, TmA indicates the melting point of the polyester in the A layer, and TmB indicates the melting point of the polyester in the B layer.)
(2) The laminated film as described in 1 above, wherein the absolute value of the difference between the refractive index in the MD direction and the refractive index in the TD direction of the B layer is 0.00 to 0.06.
(3) The laminated film as described in 1 or 2 above, wherein the intrinsic viscosity of the crystalline polyester used in the layer B is 0.60 or more.
(4) The laminated film as described in any one of 1 to 3 above, wherein the layer A is a layer mainly composed of crystalline polyester.
(5) The thickness ratio of the A layer and the B layer (XB/XA, where XA is the total thickness of the A layer and XB is the total thickness of the B layer) is 1.5 or more. 5. The laminated film according to any one of 4.
(6) At least one layer selected from the group consisting of an easily adhesive layer (layer C) having a functional group on the surface of the layer B side of the laminated film according to any one of the above 1 to 5, a surface protective layer and a colored layer A functional layer-attached laminated film in which functional layers (layer D) are laminated in this order.
(7) The laminated film with a functional layer as described in 6 above, wherein the layer C has a thickness of 10 nm to 200 nm.
(8) The laminated film with a functional layer as described in 6 or 7 above, wherein the colored layer contains 0.5% by weight or more and less than 40% by weight of the colorant based on the weight of the composition.
(9) The laminated film with a functional layer as described in any one of 6 to 8 above, wherein the surface protective layer is mainly composed of at least one resin selected from the group consisting of thermosetting resins and photocurable resins.
(10) A coating substitute film in which a colored layer and a surface protective layer are laminated in this order on the C-layer side surface of the functional layer-attached laminated film according to any one of the above 6 to 9.
(11) A film-coated laminate obtained by laminating a metal or resin on the layer A side of the laminated film, functional layer-attached laminated film, or paint substitute film described in any one of 1 to 10 above.
(12) A member using the film-covered laminate described in (11) above.
(13) A method for manufacturing a metal member, wherein the laminated film, the functional layer-attached laminated film, and the painting substitute film according to any one of the above 1 to 10 are used, and a metal plate is used at a temperature T that satisfies the following formula (2): A manufacturing method for obtaining a film-coated metal laminate by thermocompression bonding a heated metal plate to the layer A side of the laminated film.
TmA≦T≦TmB (2)
(However, TmA indicates the melting point of the polyester in the A layer, and TmB indicates the melting point of the polyester in the B layer.)
(14) A method for producing a metal member, which further comprises a step of cold press forming the film-coated metal laminate described in (13) above.

According to the laminated film of the present invention, it is possible to exhibit excellent adhesive strength to various metals and resins, and to exhibit excellent appearance design required for exterior parts of vehicles. The value of omitting the painting step in manufacturing can be tested.

Embodiment example of the paint substitute film of the present invention Embodiment example of the paint substitute film of the present invention Example Embodiments of Prior Art Paint Substitute Films

The present invention refers to a two-layer laminated film consisting of A layer and B layer, and as a preferred embodiment, at least one functional layer selected from the group consisting of a surface protective layer and a colored layer is provided on the B layer side surface via an easy-adhesion layer. A laminated film with a functional layer, a coating substitute film in which a colored layer and a surface protective layer are laminated in this order on the surface of the B layer via an easy-adhesion layer, and a film-coated laminate in which the A layer and a metal or resin are laminated. A body, a member using a film-coated laminate, a manufacturing method for laminating the A layer and a metal by thermocompression bonding, a film-coated metal plate thus obtained, and a film-coated metal plate by cold pressing Refers to a molded metal member.

The present invention will be described in detail below.

(Laminated film)
The laminated film in the present invention includes a B layer mainly composed of crystalline polyester and having a refractive index in the thickness direction of less than 1.500, and an A layer mainly composed of polyester having an intrinsic viscosity of 0.60 or more and having a thickness of 5 μm or more. A laminated film comprising layers, wherein the melting points of the polyesters of the layers A and B satisfy the following formula (1).
(TmB−TmA)≧20° C. (1)
(However, TmA indicates the melting point of the polyester of the A layer, and TmB indicates the melting point of the polyester of the B layer.) Here, the A layer is formed by thermocompression bonding with a metal or resin when creating a film-coated laminate. In addition to functioning as an adhesive layer, it has a function of relieving stress generated by physical adhesion with metal or resin. On the other hand, the B layer functions as a base material through a plurality of steps for creating a laminated film, and the stress generated by physical adhesion with the metal or resin relaxed by the A layer is reduced to the above It has a function of uniformly dispersing in the plane direction due to the in-plane orientation of the B layer. Since the A layer and the B layer have such functions, it is possible to exhibit excellent adhesion to various metals and resins, and to exhibit excellent appearance design required for exterior parts of vehicles. can. Each layer will be described in detail below.

(A layer and B layer)
The layers A and B in the present invention are mainly made of polyester. Here, the "main body" is preferably 60% by weight or more, more preferably 70% by weight or more, still more preferably 80% by weight or more, and even more preferably 90% by weight or more, based on the weight of the entire film. indicates that

A homopolyester or copolyester can be used for the polyester constituting the A layer and the B layer. As the homopolyester, a polyester having a melting point of more than 250° C. and not more than 260° C. is preferable, and homopolyethylene terephthalate is particularly preferable. The term "homopolyethylene terephthalate" as used herein does not exclude the inclusion of a diethylene glycol component that is unavoidably included. As the copolyester, a copolyester having a melting point of 160 to 250°C can be mentioned, and a copolyester having a melting point of 180 to 250°C is more preferable. Copolyester is preferably mainly composed of ethylene terephthalate units. Here, "mainly" means that the ethylene terephthalate unit is preferably 60 mol% or more, more preferably 70 mol% or more, and still more preferably 80 mol% or more in the copolyester.

The copolymer component of such copolyester may be either an acid component or an alcohol component. Examples of acid components include aromatic dicarboxylic acids other than the main acid components such as isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and the like. Examples of the alcohol component include ethylene glycol, trimethylene glycol, tetramethylene glycol and the like, and polyoxyalkylene glycol such as diethylene glycol and the like. Aliphatic diols such as 1,6-hexanediol and alicyclic diols such as 1,4-hexamethylenedimethanol can also be used. These can be used alone or in combination of two or more. Among these, isophthalic acid and sebacic acid are preferred, and isophthalic acid is particularly preferred.

The polyester constituting layer B must be a crystalline polyester. If a polyester with too low crystallinity is used, sticking to the clips tends to occur when the polyester sheet is gripped with clips and stretched in the film-forming process. In addition, process handling during lamination of functional layers, which is a post-process, becomes difficult. The crystalline polyester referred to herein means that 10 mg of the polyester composition scraped from the layer B was heated to 290°C at a rate of 20°C/min using a TA Instruments Q100 DSC, then isothermally maintained for 3 minutes, and heated to 200°C/ When it was quenched at a rate of 10°C/min and again heated to 290°C at a rate of 10°C/min, a baseline shift corresponding to the glass transition point and a temperature higher than the baseline shift occurred due to crystal melting. It means that an endothermic peak of 05 J/g or more is observed.

The polyester constituting the layer A is preferably a crystalline polyester. If a polyester with too low crystallinity is used, there is concern about clip sticking in the film forming process, as in the case of the A layer, resulting in a decrease in productivity.

In the polyester film of the present invention, the non-laminated surface maintains good smoothness and good appearance while sufficiently ensuring melt-wetting with metal or resin during lamination by heat sealing. The melting point TmB of the B layer must be higher than the melting point TmA of the A layer, and the melting point difference (TmB-TmA) must be 20° C. or more. The melting point difference of (TmB-TmA) is more preferably 25°C or more, more preferably 30°C or more, and most preferably 35°C or more. When the melting point difference is at least the lower limit, even if the temperature during lamination is high, the layer B will not begin to melt, and the appearance will be good. It is preferable because it is possible to obtain excellent adhesion between the film and metal or resin, and both appearance and adhesion can be achieved.

Further, the melting point difference of (TmB-TmA) is more preferably 70°C or less, more preferably 60°C or less, and most preferably 50°C or less. When the melting point difference is equal to or less than the upper limit, it is preferable because the handleability during film formation is good.

The intrinsic viscosity of the polyester used for the A layer must be 0.60 or more. Furthermore, the intrinsic viscosity of the polyester used for the A layer and the B layer is preferably 0.60 or more and less than 0.95, more preferably 0.65 or more and less than 0.85. When the intrinsic viscosity is above the lower limit, it has the function of relieving the stress generated by physical adhesion with metals or resins, and can exhibit excellent adhesion to various metals and resins, and is also suitable for exterior parts of vehicles. It is preferable because it can express the desired excellent appearance design. In addition, the cohesive force of the polyester layer is strengthened, and peeling of the film due to cohesive failure of the polyester layer is less likely to occur when a steel sheet laminated with a polyester film is formed. On the other hand, if it is less than the upper limit, it is difficult for the adhesiveness to deteriorate over time due to residual stress generated during molding and lamination, which is preferable.

Here, the intrinsic viscosity (IV) of the polyester of each layer was obtained by shaving the polyester of each layer from the coating substitute film, dissolving it in o-chlorophenol, and measuring the intrinsic viscosity in an atmosphere of 35°C.

Next, the thickness of the laminated film can be appropriately changed as necessary, but the total thickness is preferably in the range of 15 to 200 μm, more preferably in the range of 20 to 150 μm, particularly preferably in the range of 30 to 100 μm. If the thickness is less than the lower limit, the handleability in the film formation, functional layer lamination and lamination steps is lowered. On the other hand, those exceeding the upper limit are not preferable because the load during molding becomes large.

Furthermore, the thickness of the A layer must be 5 μm or more, preferably 8 μm or more. If the A layer has a thickness of less than 5 μm, sufficient melt wetting is not ensured during lamination with a steel plate, and adhesion between the film and the metal plate is lowered, which is undesirable.

Furthermore, the thickness ratio of the A layer and the B layer (X _B /X _A : where X _A is the total thickness of the A layer, and X _B is the total thickness of the B layer) improves the adhesion between the film and the metal plate. It is preferably 1.5 or more, more preferably 2.0 or more, from the viewpoint of maintaining a good appearance.

Layers A and B may optionally contain other additives, such as coloring pigments, fluorescent brighteners, antioxidants, heat stabilizers, and ultraviolet absorbers, as long as they do not interfere with the object of the present invention. , an antistatic agent, etc. can be added. When a polyester film is used as a metal masking layer, it is preferable to add a coloring pigment, which may be inorganic or organic, but inorganic is preferred. Preferred inorganic pigments include alumina, titanium dioxide, calcium carbonate, barium sulfate, and the like, with titanium dioxide being more preferred. The content of the color pigment is preferably more than 2% by weight and 50% by weight or less, more preferably 5 to 40% by weight, more preferably 10 to 35% by weight, based on the weight of the B layer. . Fluorescent whitening agents are particularly effective for improving whiteness. Also, inert particles may be added in order to improve the handleability in the film-forming process and the molding process. The inert particles to be contained are not particularly limited as long as they can stably exist in the polymer, and those known per se can be employed, such as polystyrene, polymethyl acrylate, polyethyl acrylate, and polymethacryl. Polymers or copolymers of each monomer selected from acid methyl ester, polymethacrylic acid ethyl ester, and divinylbenzene, organic substances such as polytetrafluoroethylene, polyacrylonitrile, benzoguanamine, silicon, silica, kaolin, It is preferable to use one of inorganic materials such as talc and graphite. The preferred particle size of these inert particles is 0.1-10 μm, and the preferred content is in the range of 0.002-0.5% by weight.

The thickness direction refractive index of the B layer in the present invention is less than 1.500, preferably 1.498 or less, more preferably 1.496 or less. When the refractive index in the thickness direction of the B layer is equal to or less than the upper limit, the stress generated by physical adhesion with the metal or resin relaxed by the A layer is uniformly distributed in the plane direction by the orientation in the film plane of the B layer. The function of dispersing the particles into the particles can be expressed, and the excellent appearance design required for the exterior parts of the vehicle can be expressed.

The difference between the refractive index in the MD direction and the refractive index in the TD direction of the B layer is preferably 0.00 to 0.06, more preferably 0.00 to 0.05. This range is preferable because the above-described function of uniformly dispersing the particles in the surface direction can be exhibited more effectively and excellent image sharpness can be obtained.

On the other hand, the orientation state of the A layer in the present invention is not particularly limited, and may be uniaxially or biaxially oriented as long as the object of the present invention can be achieved, or may be non-oriented. Biaxially oriented is preferred from the viewpoint of uniform film-forming properties of the film, productivity, and uniform moldability when molding the film-coated metal laminate.

The method for producing the A layer and the B layer in the present invention is not particularly limited, and conventionally known film forming methods can be applied. As an example, when producing a biaxially oriented laminated film, an unstretched laminated sheet may be first prepared and then stretched in two directions.

For example, for layer A, a polyester composition is prepared by adding inert particles to polyester, dried sufficiently, and then melted in an extruder at a temperature between the melting point and (melting point +50) °C. The melting point here is the melting point of the polyester used. At the same time, a polyester composition is prepared by adding inert particles to the crystalline polyester for the B layer, dried sufficiently, supplied to another extruder, and melted at a temperature of the melting point to (melting point + 50) ° C. Subsequently, a laminated unstretched laminated sheet is produced by a method of laminating both molten resins inside a die, for example, a simultaneous lamination extrusion method using a multi-manifold die. According to such a simultaneous lamination extrusion method, the melted resin that forms one layer and the melted resin that forms another layer are laminated inside the die, and are formed into a sheet from the die while maintaining the laminated form. be.

Then, the unstretched laminated sheet can be successively or simultaneously biaxially stretched and heat-set. When the film is formed by sequential biaxial stretching, the unstretched laminated sheet is first stretched in the longitudinal direction by heating with roll heating, infrared heating, or the like, and then transversely stretched with a stenter. At this time, the stretching temperature is preferably 20 to 50° C. higher than the glass transition point (Tg) of the polyester (preferably the polyester of the layer B), and the longitudinal stretching ratio is preferably 2.0 to 5.0 times. , more preferably 2.2 to 4.0 times, more preferably 2.5 to 3.6 times, and the transverse draw ratio is preferably 2.5 to 5.0 times, more preferably 2.6 to 4 times. 0.0 times, more preferably 2.8 to 3.8 times. The temperature of heat setting is preferably selected in the range of 150-240° C., more preferably 150-230° C., depending on the melting point of the polyester to adjust the film quality.

(Easy adhesion layer (C layer))
A mode in which an easily bonding layer C (layer C) is laminated on the surface of the layer B of the laminated film of the present invention is preferable. The C layer has a function of improving the adhesion between the laminated film and the functional layer described later. Further, the C layer preferably has a functional group from the viewpoint of obtaining excellent image sharpness. Although the cause is not clear, the presence of the functional group improves the interlayer adhesion, and the effect of the layer A as a stress relaxation layer and the transmission of the stress relieved by the layer B are uniformly distributed in the plane direction. It is presumed that the effect is easily transmitted to the functional layer through the easy-adhesion layer.

As the functional group, at least one functional group selected from the group consisting of an epoxy group, an oxazoline group, a silanol group, and an isocyanate group is preferred. Among these, it is preferable to contain an epoxy group or an oxazoline group from the viewpoint of obtaining excellent adhesion to the B layer and image sharpness. The easy-adhesion layer C in the present invention preferably has a thickness in the range of 10 to 200 nm, and the preferred lower limit of the thickness is 15 nm, further 20 nm, particularly 40 nm from the viewpoint of adhesion. On the other hand, the upper limit of the thickness is preferably 180 nm, more preferably 150 nm, particularly 120 nm, from the viewpoints of thickness unevenness reduction in coating and adhesion.

As described above, the easy-adhesion layer C in the present invention preferably contains at least one functional group selected from the group consisting of epoxy groups, oxazoline groups, silanol groups, and isocyanate groups. As the resin itself to be formed, as long as it has excellent adhesion to the laminated film and the functional layer, a known one can be adopted. can be suitably used to improve adhesion by blending, for example, polyurethane resin, vinyl chloride/vinyl acetate copolymer resin, vinyl chloride/vinyl acetate/acrylic copolymer resin, chlorinated Any of polypropylene-based resin, acrylic-based resin, polyester-based resin, polyamide-based resin, butyral-based resin, polystyrene-based resin, nitrocellulose-based resin, cellulose acetate-based resin, etc. may be used singly or in combination of two or more. used in combination with Molding by cold press in the present invention preferably reaches a molding temperature of about 150 ° C., so it is preferable that the glass transition temperature is designed to be lower than this temperature. It can be preferably used.

The easy-adhesion layer C may be applied by in-line coating in which coating is performed during film formation of the laminated film, or after the laminated film is formed, it is once wound into a roll and then fed out again to perform offline coating. can be

The easily adhesive layer C obtained in this way improves the adhesion between the laminated film and the functional layer due to the effects of bond formation between functional groups, reduction of interlayer interfacial energy, and interfacial mixing between layers when laminating the functional layers described later. contribute to

(functional layer)
It is preferable that the layer B surface of the laminated film of the present invention has at least one functional layer selected from the group consisting of a surface protective layer and a colored layer via an easy-adhesion layer C (C layer). Moreover, it is more preferable that the easily bonding layer C (layer C), the colored layer, and the surface protective layer are laminated in this order on the layer B surface of the laminated film of the present invention. By laminating each layer in this order, the adhesion between the laminated film and the functional layer is improved, and an excellent appearance design can be expressed, which is preferable.

The colored layer preferably contains at least one colorant selected from the group consisting of binder resins, pigments, and dyes, and the colorant is 0.5% by weight or more based on the weight of the composition used for the colored layer. , is preferably less than 40% by weight from the viewpoint of design. A more preferable range is 2% by weight or more and less than 30% by weight, and a particularly preferable range is 5% by weight or more and less than 25% by weight. If no binder resin is used, the elongation during molding will easily cause cracks in the colored layer, resulting in poor appearance. Also, by using pigments or dyes, a beautiful and excellent appearance can be formed. Pigments or dyes used include carbon black (ink), iron black, titanium white, antimony white, yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, cobalt blue, quinacridone red, isoindolinone yellow, and phthalocyanine. It is preferably one selected from the group consisting of blue, aluminum, brass, titanium dioxide, and pearlescent pigments. The use of other pigments and additives for toning is a preferred embodiment as long as it does not impair the present invention.

The method of forming the colored layer is not particularly limited, but the method of lamination by coating is simple and preferable. Adhesion between the colored layer and the B layer can be appropriately adjusted depending on the types of the B layer and the easily adhesive layer C and the binder resin used for the colored layer.

When the colored layer is used for the exterior of a vehicle, it may be multi-layered in order to express a beautiful design. For example, as shown in FIG. It is also preferable to form a two-layer colored layer by providing a colored layer containing a glitter pigment as the glitter layer 33, and considering the reflection characteristics from the viewing side, the colored layer on the side closest to the laminated film 1 It is also preferable to form a three-layer colored layer including a colored reflective layer made of an aluminum pigment, a colored pigment layer, and a bright pigment layer 33 of a clear coating film. The use of the colored layer as a single layer or as multiple layers does not negate the object of the present invention, in order to impart the required design properties. Similarly, it does not particularly impair the present invention to form a multilayer surface protective layer as necessary.

The resin used for the surface protective layer is mainly composed of at least one resin selected from the group consisting of thermosetting resins and photocurable resins in view of compatibility with manufacturing processes from coating substitute film manufacturing to metal member molding. preferable. In particular, acrylic resins are preferably used from the viewpoint of weather resistance, scratch resistance, and transparency.

The thickness of the surface protective layer in the present invention is preferably 5 to 80 μm after drying. Since the thickness of the surface protective layer is at least the above lower limit, the amount of resin material is small and it is economical. unable to maintain altitude. On the other hand, when the thickness is equal to or less than the upper limit, although the hard coat film is excellent in gloss expression and protective performance, it is not economical because the resin is used more than necessary. The lower limit of the thickness of the surface protective layer is preferably 10 μm, more preferably 15 μm, while the upper limit is 60 μm, more preferably 50 μm.

Furthermore, the surface protective layer in the present invention may be composed of a single layer or multiple layers. For example, when coating the same resin twice with multiple layers, the degree of curing can be adjusted by changing the drying conditions, and when providing a functional layer such as an antifouling layer further outside the surface protective layer Adhesion can be improved. In addition, a glossy surface can be developed by forming multiple layers within the range described above.

The surface protective layer in the present invention is preferably laminated on the laminated film by coating, and the method thereof may be a known coating method, but it is preferable to wind the film in a semi-cured state into a roll. When the hard coat paint is dried, the primary reaction proceeds due to heat, and the hard coat becomes a coating film in a semi-cured state, which makes it possible to take up. By designing the semi-cured surface protective layer so that the secondary reaction proceeds at a temperature higher than the drying temperature described above, the semi-cured surface protective layer is semi-cured by the heat generated during lamination to a metal plate or molding of a member. The degree of effectiveness can progress from cure to cure.

(Other lamination)
The coating substitute film in the present invention may be further laminated on the surface of the functional layer, if necessary. Examples include an antifouling layer for preventing contamination during outdoor use, and a laminate of a protective film for improving handling properties in the manufacturing process. In particular, when laminating the surface protective layer in a semi-cured state, it is preferable to laminate a protective film in order to improve handleability in the post-process. The protective film may be peeled off at any time, but it is preferable from the viewpoint of scratch resistance to peel off after thermocompression lamination with the metal plate and cold press molding of the film-coated metal laminate. Examples of protective films include polyethylene resins, polyester resins, copolymerized polyester resins, polypropylene resins, polyvinyl chloride resins, and films made of mixtures thereof. , copolyester resins are preferred. The thickness of the film is not particularly limited, but a thickness of 15 to 150 μm is preferable in order to sufficiently exhibit the protective function.

(Film coated resin laminate)
The film-coated resin laminate in the present invention is usually produced by insert molding in which the laminated film is set in a mold and resin is injected.

(Film-coated metal laminate)
The film-coated metal laminate in the present invention is obtained by laminating a metal plate and the layer A side of the laminate film by thermocompression bonding, and does not use an adhesive for lamination. A metal plate is usually wound into a roll, and a coating substitute film can also be used as a product in a roll.

As a preferred method for producing the film-coated metal laminate, for example, the metal plate is heated and the A layer side of the supplied coating substitute film is crimped with a nip roll to bond the film to the metal plate. At that time, the temperature T of the metal plate during thermocompression bonding is set to be equal to or higher than the melting point TmA of the laminated film A layer and to be equal to or lower than the melting point TmB of the laminated film B layer, thereby ensuring melt wetting between the metal plate and the A layer. , B layers can be prevented from melting, so that excellent adhesive strength with a metal plate and appearance design can be obtained. A portion of the thermocompression-bonded coating substitute film is melted by the heat from the metal plate, but it solidifies and recrystallizes in the process of cooling, which reduces the moldability thereafter. In order to prevent this, it is preferable to rapidly cool the film-coated metal laminate after thermocompression bonding. Although the method of quenching is not particularly limited, a known method such as a method of immersing in a cold water bath or a method of spraying cold water can be used. The time from thermocompression bonding to quenching should be as short as possible, preferably within 5 seconds, more preferably within 3 seconds, particularly preferably within 1 second.

The metal plate used for thermocompression bonding can be appropriately selected from known ones according to the purpose of use of the metal member, and includes steel plate, galvanized steel plate, tin-free steel (chromium plated steel plate), tin plate, aluminum plate, stainless steel. Although a plate etc. are illustrated, it is not limited to these. In general, a metal plate having good formability and a thickness of about 0.3 to 1.0 mm is used, so it is preferable to use such a grade. For example, if it is a metal plate used for the exterior of a vehicle, a steel plate with a thickness of 0.4 to 0.8 mm and an aluminum plate with a thickness of 0.6 to 1.2 mm that has been zinc alloy plated as a rust prevention treatment. is a preferred embodiment.

(Metal member)
The film-coated metal laminate, in which the metal plate and the coating substitute film are integrated by thermocompression bonding, is press-molded into a shape according to its intended use. Cold pressing is preferred as the press molding method. When cold press forming is performed on the above-mentioned film-coated metal laminate, even if the end of the metal plate is stretched at high pressure, it is held at low pressure and the metal plate is sucked by forming (squeezing). Even in the case of molding), it is possible to cover the surface of the metal member with a coating substituting film by thermocompression bonding to the surface of the metal plate in advance as described above.
The above contents will be described in more detail using examples and comparative examples shown below.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited only to these Examples. Each characteristic value is measured by the following method. Also, parts and % in the examples mean parts by weight and % by weight, respectively, unless otherwise specified.
(Refractive index in thickness direction)
It was measured with an Abbe refractometer manufactured by Atago (D line 589 nm, measurement range 1.3 to 1.7). The sample was cut into a width of 2 cm and a length of 3 cm, the measurement was performed twice, and the average value was used as the result.
(melting point)
The melting point of each layer of the laminated film is measured using a TA Instruments Q100 DSC, and the melting peak is determined at a heating rate of 20° C./min. As a sample, 10 mg of the polyester composition scraped from each layer of the film is used.
Here, the melting point peak was defined as an endothermic peak of 0.05 J/g or more associated with crystal melting on the higher temperature side than the baseline shift corresponding to the glass transition point.
(Intrinsic viscosity)
Each layer of polyester was scraped out from the coating substitute film, dissolved in o-chlorophenol, and measured at 35° C. to determine the intrinsic viscosity.
(Thickness of each layer of coating substitute film)
A sample of 2 mm in the longitudinal direction and 2 cm in the width direction was cut out, fixed in an embedding capsule, and then embedded in an epoxy resin. Then, the embedded sample is cut perpendicularly to the width direction with a microtome (Supercut manufactured by Reichert-Jung) to obtain thin slices with a thickness of 50 μm. Using a scanning electron microscope (Hitachi 4300SE/N), observation and photography were performed at an acceleration voltage of 20 kV, the thickness of each layer was measured from the photograph, and the average thickness of five points was obtained.
(Average particle size of particles in easy-adhesion layer)
The surface of the ultra-thin section obtained above was observed with an SEM (scanning electron microscope), the diameters of 50 particles were measured, and the number-averaged particle diameter was obtained as the average particle diameter.
(Presence or absence of epoxy groups, oxazoline groups, silanol groups, and isocyanate groups in the easy contact layer)
The existence of the above functional groups was confirmed using H ¹ -NMR on the ultrathin section obtained above.

(Adhesion between film and metal plate)
When the A layer side of the coating substitute film and the metal plate are thermocompressed, heat-resistant paper is sandwiched to create a peeled edge. The obtained film-coated metal laminate with the peeled edge was cut into a size of 20 mm in width and 150 mm in length, and using Tensilon, one chuck held the metal plate and the other chuck held the film peeled edge, The average value of the maximum load when the tensile test was performed three times in the 180° direction was taken as the average value. The chuck-to-chuck distance is 50 mm, and the tensile speed is 50 mm/min.

(Film-colored interlayer adhesion)
From the functional layer side of the coating substitute film, make scratches in a grid pattern so as to reach the B layer, attach Nichiban 31B tape to the surface, and peel off the tape rapidly in the direction perpendicular to the film surface. A peeling test of 100 squares is performed by The obtained results are observed under a microscope, and evaluated as ⊚, ◯, Δ, and x according to the number of peeling points.
○: Peeling and cracking of the coating film are observed only 1/100 or less, which is good △: 2/100 to 10/100 peeling points or cracking of the coating film is observed in the grid ×: 11/ in the grid Over 100 delamination points or coating cracks observed

(Vividness)
The film-coated metal laminate is placed with the functional layer facing up at a position offset by 50 cm from directly below a fluorescent lamp at a height of 2.5 m. Next, the image of the fluorescent lamp projected onto the metal plate is visually observed from the position where the image of the fluorescent lamp appears reflected, and the evaluation is made according to the following criteria.
〇: There is almost no distortion in the image of the fluorescent light △: The image of the fluorescent light is partially distorted ×: The image of the fluorescent light is totally distorted

(Coating liquid)
As a coating liquid for coating the easy-adhesion layer C, the components shown below were used. The composition types and proportions are shown in Tables 1 and 2. The blending ratio of the paint is mainly composed of binder resin water-based paint, cross-linking agent water-based paint, and filler water-dispersed paint, and surfactant is added to make the total solid content 100%, and the solid content concentration of the coating liquid is 3. % to obtain a water-based coating liquid. Each water-based coating liquid is supplied by a pump, passed through a coating liquid filter through a route constructed for paint circulation, and after removing foreign matter, is accumulated in the coating liquid pan and applied to the film by reverse roll coating. By working, a coating film was formed.

(Binder resin of easy adhesion layer C)
The binder resin used for the easy adhesion layer C is an acrylic resin composed of a copolymer component of 40 mol% methyl methacrylate/45 mol% ethyl acrylate/10 mol% acrylonitrile/5 mol% N-methylolacrylamide. was used. As the polyester resin, a blend of polyester resin 1 and polyester resin 2 composed of the following copolymer components was used. Specifically, a polyester resin 1 containing terephthalic acid as a carboxylic acid component, 60 mol % ethylene glycol as a glycol component, 65 mol % naphthalenedicarboxylic acid and 35 mol % isophthalic acid as a carboxylic acid component, and ethylene as a glycol component. A binder resin obtained by blending polyester resin 2 containing 60 mol % of glycol at a binder resin ratio of 1:1 was used. As the siloxane-based resin, a silane coupling agent composed of glycidoxypropyltrimethoxysilane modified with a functional group having a glycidyl group was used as the silicon in order to ensure adhesion with the B layer. As the urethane-based resin, a water-soluble urethane resin manufactured by Kusumoto Kasei Co., Ltd. under the trade name of NeoRezR986 was used.

(Crosslinking agent for easy adhesion layer C)
The cross-linking agent used for the easy adhesion layer C is, as an epoxy-based cross-linking agent, a bifunctional trade name “Denacol EX-313” manufactured by Nagase Chemical Industry Co., Ltd., and a tetrafunctional product manufactured by Mitsubishi Gas Chemical Co., Ltd. The product name "TETRAD-X" was mixed and used. Based on the film-forming property of the coating film applied to the film and the adhesion after molding, increase the bifunctional cross-linking agent ratio to increase the curing speed of the coating film, and 4 to slow down the curing speed. It is preferred to reduce the proportion of functional cross-linking agents. As the oxazoline-based cross-linking agent, trade name "Epocross WS-700" manufactured by Nippon Shokubai Co., Ltd. was used. Regarding cross-linking of silanol and isocyanate, it has a cross-linking form utilizing the reactive points contained in the binder resin described above.

(Filler for easy adhesion layer C)
The filler used for the easy adhesion layer C is the product name "Snowtex XS" and "ST-OL" manufactured by Nissan Chemical Industries, Ltd., the product name "Eposter MX200W" manufactured by Nippon Shokubai Co., Ltd., Nippon Shokubai Co., Ltd. The product name "Me-6u" manufactured by the company was used.

[Examples 1 to 10, Comparative Examples 1 to 3]
The polyester composition for layer A and the polyester composition for layer B shown in Tables 1 and 2 were dried independently at 140° C. and 160° C., and both the A layer and the B layer were melted at 280° C., and then subjected to a two-layer feed block. They were laminated in a two-layer configuration of A/B, co-extruded from adjacent dies, and rapidly solidified to obtain an unstretched laminated film. Next, after longitudinally stretching this unstretched film 3.0 times at 100 ° C., using a reverse roll coater, the easily adhesive layer C shown in Tables 1 and 2 is laminated on the surface of the B layer. The film was transversely stretched 3.5 times at 200° C. and heat-set at 200° C., and the obtained biaxially oriented polyester laminated film was wound into a roll. In addition, 0.1% by weight of silica particles having an average particle diameter of 2.0 μm were added as inert particles to the polyester compositions for the A layer and the B layer.

Next, the laminated film was unwound, and the colored layer was first coated with a comma coater. For the colored layer, a solvent paint containing 20% by weight of acrylic urethane resin as a binder component, 20% by weight of titanium particles as a pigment, and 35% by weight of non-volatile components was used. It was coated so as to have a thickness of 20 μm, dried in a drying oven at 90° C., and then wound up.

The raw fabric coated with the colored layer is fed out again, and subsequently, in order to form a surface protective layer, a hard coat paint (HC-1) described later is applied with a comma coater to a non-volatile content of 30% by weight of HC-1. After coating with a thickness of 15 μm (thickness after curing), it is sufficiently dried in a drying oven set at 90° C., and laminated with a polyethylene resin film having a thickness of 50 μm as a protective film before winding. Then, the film was wound into a roll to obtain a coating substitute film.

[Comparative Example 4]
After obtaining an unstretched laminated film in the same manner as in Example 1 using the polyester composition for layer A and the polyester composition for layer B shown in Table 2, it was longitudinally stretched 2.9 times at 100 ° C. and stretched at 140 ° C. A laminated film and a coating substitute film were obtained in the same manner as in Example 1, except that the film was laterally stretched 3.0 times.

<Hard coat paint (HC-1)>
150 parts of methyl isobutyl ketone (MIBK) was charged into a four-necked flask equipped with a condenser, a stirrer, a thermometer and a nitrogen inlet tube, and the temperature was raised while stirring under a nitrogen atmosphere. When the temperature in the flask reached 74° C., this temperature was maintained as the synthesis temperature, and 3 parts of methyl methacrylate, 82.54 parts of n-butyl methacrylate, 12.85 parts of 4-hydroxybutyl acrylate, and 0 parts of methacrylic acid were added. .61 parts, 1 part of Fancryl FA-711MM (manufactured by Hitachi Chemical Co., Ltd., pentamethylpiperidinyl methacrylate), and 0.1 part of azobisisobutyronitrile were added dropwise over 2 hours. . 0.02 part of azobisisobutyronitrile was added every hour from 1 hour after the completion of dropping the monomer, and the reaction was continued until the unreacted monomer in the solution became 1% or less. When the amount of unreacted monomers decreased to 1% or less, the reaction was terminated by cooling to obtain an acrylic copolymer solution having a solid content of about 40%. To this acrylic copolymer solution, 59.9 parts by mass (solid mass) of Duranate "P301-75E" (manufactured by Asahi Kasei Chemicals, polyisocyanate of hexamethylene diisocyanate, hereinafter referred to as curing agent 1) is added as a polyisocyanate compound. In addition, methyl isobutyl ketone (MIBK) was added and stirred so that the solid content was 30%, to obtain a hard coat paint (HC-1).

Next, using the coating substitute film obtained above, thermocompression bonding was performed on a plated steel sheet JAC270F45/45 to prepare a film-coated metal laminate. Specifically, the paint substitute film is unwound (unrolled), the metal plate is heated and guided at the temperatures shown in Tables 1 and 2, and a laminate roll is used to heat and press the A layer side of the paint substitute film. and laminated. The laminated metal plate was introduced into a cooling water bath and cooled within 3 seconds to obtain a film-coated metal laminate. The line speed during lamination was 20 m/min.
After peeling off the protective film from the film-coated metal laminate, the adhesion between the film and the metal plate, the adhesion between the film and the colored layer, and the sharpness of the image were evaluated. Table 3 shows the results.

[Example 11]
A film-coated metal laminate prepared in the same manner as in Example 1 was subjected to cold press molding with the protective film laminated thereon. Using a die having a drawing ratio of 1.3, the peripheral portion of the metal plate was held with a load of 15 tons, and the central portion of the metal plate was cold-pressed at 50 tons for draw forming. The appearance of the obtained metal member was checked with the protective film removed, and it was found that the metal member had good moldability without peeling or tearing of the film.

In Tables 1 and 2, PET is homopolyethylene terephthalate, and IAx-PET is x mol % isophthalic acid-copolymerized polyethylene terephthalate. CHDMx-PET is x mol % cyclohexanedimethanol copolymerized polyethylene terephthalate.

The embodiment has been described as being applied to automobile parts and the like. However, the present invention is not limited to this, and for example, the paint substitute film may be used for vehicles other than automobiles (motorcycles, trucks, etc.), ships (motorboats, etc.), home appliances, audio products, construction members, steel plate products, etc. .

1 Laminated Film 11 A Layer 12 B Layer 2 Easily Adhesive Layer C
3 functional layer 31 colored layer 32 surface protective layer 33 glitter material layer 4 clear layer 5 adhesive layer

Claims (12)

A coating substitute film in which a laminated film, an easy-adhesion layer (C layer) having a functional group on the B layer side surface of the laminated film, a colored layer, and a surface protective layer are laminated in this order,
The laminated film includes a B layer mainly made of crystalline polyester and having a refractive index in the thickness direction of less than 1.500, and an A layer mainly made of polyester having an intrinsic viscosity of 0.60 or more and having a thickness of 5 μm or more. A painting substitute film in which the melting point of the polyester of the A layer and the B layer satisfies the following formula (1).
(TmB−TmA)≧20° C. (1)
(However, TmA indicates the melting point of the polyester in the A layer, and TmB indicates the melting point of the polyester in the B layer.) 2. The painting substitute film according to claim 1, wherein the absolute value of the difference between the refractive index in the MD direction and the refractive index in the TD direction of the layer B is 0.00 to 0.06. 3. The painting substitute film according to claim 1, wherein the crystalline polyester used for the layer B has an intrinsic viscosity of 0.60 or more. The painting substitute film according to any one of claims 1 to 3, wherein the layer A is a layer mainly composed of crystalline polyester. The thickness ratio between the A layer and the B layer (X _B /X _A : where _XA is the total thickness of the A layers, and X _B is the total thickness of the B layers) is 1.5 or more. 5. The painting substitute film according to any one of 1 to 4. The painting substitute film according to any one of claims 1 to 5, wherein the C layer has a thickness of 10 nm to 200 nm. The painting substitute film according to any one of claims 1 to 6, wherein the colored layer contains 0.5% by weight or more and less than 40% by weight of the coloring agent based on the weight of the composition. The painting substitute film according to any one of claims 1 to 7, wherein the surface protective layer is mainly composed of at least one resin selected from the group consisting of thermosetting resins and photocurable resins. A film-coated laminate obtained by laminating a metal or resin on the A layer side of the painting substitute film according to any one of claims 1 to 8. A member using the film-coated laminate according to claim 9 . A method for manufacturing a metal member, wherein the coating substitute film according to any one of claims 1 to 8 and a metal plate are used, and the metal plate is heated at a temperature T that satisfies the following formula (2), A manufacturing method for obtaining a film-coated metal laminate by thermocompression bonding to the A layer side of the laminated film of the paint substitute film .
TmA≦T≦TmB (2)
(However, TmA indicates the melting point of the polyester in the A layer, and TmB indicates the melting point of the polyester in the B layer.) A method for manufacturing a metal member, further comprising the step of cold press forming the film-coated metal laminate according to claim 11 .

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