JP4957305B2 - Resin sheet - Google Patents

Description

  The present invention relates to a cosmetic film using a laminated film in which layers composed of at least two kinds of resins are laminated.

  A decorative sheet using resin as a base material, or a decorative sheet or molded product obtained by laminating and integrating this decorative sheet on an adherend such as a wooden board or a resin molded product, etc. It is used for various applications such as products (parts) such as various home appliances and building materials. There is a metallic appearance as a kind of design expression in such cosmetics, and as one of them, hairline processing tone, spin processing tone, etc. expressed by many fine linear scratches applied by scratch processing There is a scratch design.

  As one method for obtaining a scratch design with a metallic appearance, there is a method in which scratching such as hairline processing or spin processing is actually performed on the surface of a metal plate itself such as aluminum or iron. When the metal plate is scratched, it becomes expensive compared to a decorative sheet using a resin as a base material or a decorative material imitating the scratch design using the decorative sheet. Furthermore, since it is a metal simple substance, there is a drawback that the strength is insufficient in a thin state, and on the other hand, if it is formed thick, it is heavy and lacks flexibility and workability.

  As another method for obtaining a scratch design with a metallic appearance, there is known a method for obtaining a hairline metallic luster by forming a hairline and a metal deposition layer on the surface of a resin such as plastic. Examples of such a method include an insert film having a hairline (see Patent Document 1), a metal-like decorative sheet (see Patent Document 2) provided with a hairline-like emboss on the surface, and scratching the surface. A metal-deposited plastic film (see Patent Document 3) having a metal-deposited surface is known. However, the method of forming the metal vapor deposition layer on the processed surface has problems that the adhesion between the plastic film and the metal vapor deposition layer is inferior and that the metal layer is difficult to recycle. Furthermore, since the electromagnetic shielding properties are generated due to the metal layer, there are cases where electromagnetic interference may occur when used as a decorative material for automobiles, mobile phones, home appliances, and the like, which is becoming a problem.

On the other hand, various films in which thermoplastic resins are laminated in multiple layers have been proposed. For example, by attaching a film laminated in multiple layers with excellent tear resistance to the glass surface, breakage and scattering of the glass can be largely prevented. (See Patent Document 4). In addition, there are films (see Patent Documents 5 and 6) that selectively reflect specific wavelengths by alternately laminating resin layers having different refractive indexes.
This film that selectively reflects a specific wavelength can be made metallic by making the reflection band visible light. However, in conventional laminated films, when scratching is performed, frictional heat is generated on the scratching surface and resin fusion occurs, which makes it difficult to process continuously, and scratched parts. However, there was a problem that delamination was very easy and solvent resistance was lowered.
Japanese Patent Laid-Open No. 10-15987 JP-A-8-216334 Japanese Patent Laid-Open No. 17-14530 JP-A-10-76620 JP-A-4-295804 Japanese Patent Laid-Open No. 9-506837

  In view of the problems of the prior art described above, the present invention continuously scratches a laminated film capable of selectively reflecting light of a specific wavelength, has excellent formability, and has excellent delamination. And providing a resin sheet having solvent resistance. It is another object of the present invention to provide a decorative film that has a small environmental load, is excellent in recyclability, and does not cause electromagnetic interference.

In order to solve the above problems, the resin sheet of the present invention comprises a layer (A layer) made of resin A which is polyethylene terephthalate or polyethylene naphthalate and a layer (B layer) made of resin B which is a polyester containing spiroglycol. A structure in which five or more layers are alternately laminated, and the surface of the laminated film having at least one reflection band having a relative reflectance of 30% or more is subjected to scratch processing that satisfies the relationship L> R. And

  Since the resin sheet of the present invention is characterized by the above-described constituent elements, it is possible to continuously scratch the resin sheet, and it is possible to provide a resin sheet having excellent moldability, no delamination, and solvent resistance.

  In addition, by setting the maximum depth (R) for scratching to 0.01 μm or more and 5 μm or less, it is possible to suppress a decrease in film strength and improve scratch processing continuity.

Moreover, when the film thickness of the laminated film is 10 μm or more, the scratch processability can be improved.
Moreover, the decorative film comprising the resin sheet of the present invention has a low environmental load, is excellent in recyclability, and does not cause electromagnetic interference.

Hereinafter, embodiments of the present invention will be described in detail.
The resin sheet of the present invention has 5 or more layers alternately composed of a layer made of resin A (A layer) which is polyethylene terephthalate or polyethylene naphthalate and a layer (B layer) made of resin B which is a polyester containing spiroglycol. The surface of the laminated film including the laminated structure and having at least one reflection band with a relative reflectance of 30% or more must be subjected to scratch processing that satisfies the relationship L> R. Such a film can be continuously scratched, has excellent moldability, has no delamination, and has solvent resistance.

Various additives in tree butter in the present invention, for example, antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, viscosity reducers, heat stabilizers, lubricants, infrared absorbing agents, ultraviolet absorbers, A dopant for adjusting the refractive index may be added.

  The thermoplastic resin of the present invention is particularly preferably polyester from the viewpoints of strength, heat resistance, and chemical resistance. The polyester referred to in the present invention refers to a homopolyester or a copolyester that is a polycondensate of a dicarboxylic acid component skeleton and a diol component skeleton. Here, typical examples of the homopolyester include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, and polyethylene diphenylate. In particular, polyethylene terephthalate is preferable because it is inexpensive and can be used in a wide variety of applications.

  The copolyester in the present invention is defined as a polycondensate comprising at least three or more components selected from the following dicarboxylic acid component skeleton and diol component skeleton. Examples of the dicarboxylic acid skeleton component include terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 4 4,4'-diphenylsulfone dicarboxylic acid, adipic acid, sebacic acid, dimer acid, cyclohexanedicarboxylic acid and ester derivatives thereof. Examples of the glycol skeleton component include ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentadiol, diethylene glycol, polyalkylene glycol, and 2,2-bis (4 '-Β-hydroxyethoxyphenyl) propane, isosorbate, 1,4-cyclohexanedimethanol and the like.

  In the laminated film of the present invention, the difference between the in-plane average refractive index of the A layer and the in-plane average refractive index of the B layer is preferably 0.03 or more. More preferably, it is 0.05 or more, More preferably, it is 0.1 or more. When the refractive index difference is smaller than 0.03, a sufficient reflectance cannot be obtained, which is not preferable. Moreover, it is more preferable that the difference between the in-plane average refractive index of the A layer and the refractive index in the thickness direction is 0.03 or less because the reflectance does not decrease even when the incident angle is increased.

  Including the structure in which layers of the resin A of the present invention (A layer) and layers of the resin B (B layer) are alternately laminated includes a structure in which the A layer and the B layer are regularly laminated in the thickness direction. Is defined to exist. That is, it is preferable that the order of arrangement in the thickness direction of the A layer and the B layer in the film of the present invention is not in a random state, and the order of arrangement of the third layer or more other than the A layer and the B layer is as follows. It is not particularly limited. In addition, in the case of having a C layer composed of an A layer, a B layer, and a thermoplastic resin C, they are laminated in a regular permutation such as A (BCA) n, A (BCBA) n, A (BABCBA) n. Is more preferable. Here, n is the number of repeating units. For example, in the case of A (BCA) n where n = 3, this indicates that the layers are stacked in a permutation of ABCABCABCA in the thickness direction.

  In the present invention, it is important that five or more layers each consisting of a resin A (A layer) and a resin B (B layer) are alternately included. More preferably, it is 50 layers or more, More preferably, it is 200 layers or more. If a structure in which five or more A layers and B layers are laminated is not included, sufficient reflectance cannot be obtained. Further, the upper limit is not particularly limited, but it is preferably 1500 layers or less in consideration of a decrease in wavelength selectivity accompanying a decrease in stacking accuracy due to an increase in the size of the device and an increase in the number of layers. .

  In addition, it is important that the resin sheet of the present invention has at least one reflection band with a relative reflectance of 30% or more. More preferably, it is 60% or more, More preferably, it is 80% or more. A relative reflectance of 80% or more is particularly preferable because a decorative film with high glossiness is obtained.

  Further, it is important that the resin sheet of the present invention is obtained by subjecting the surface of the laminated film to scratch processing that satisfies the relationship L> R. L is the thickness of the outermost layer of the laminated film on the side subjected to scratching, and R represents the maximum depth of scratching. Scratch processing is processing that gives fine line-shaped scratches and gives decorativeness. Scratch processing may be performed on both surfaces of the laminated film, or may be performed only on one of the surfaces. Considering film strength retention and design properties, it is preferable to process only one side of the laminated film. In addition, when the processing satisfying the relationship of L> R is performed, it is more preferable that the layer made of a resin having a high Tg is the outermost layer, thereby suppressing the fusion of the film due to frictional heat generated during the scratch processing, Scratch processing can be performed continuously. More preferably, the layer thickness of the outermost layer of the laminated film is 1.2 times or more and 7 times or less the maximum depth of scratch processing. This is because when the thickness of the outermost layer of the laminated film is less than 1.2 times the maximum depth of scratch processing, the film may swell due to the solvent used when the solvent resistance test is performed. .

  In the resin sheet of the present invention, it is preferable that at least one surface of the laminated film is a hard coat layer, and the hard coat layer is scratched. By making the surface a hard coat layer, it is possible to obtain a resin sheet having excellent scratch resistance, wear resistance and hardness. Furthermore, a hard coat layer having a refractive index equivalent to the refractive index of the laminated film is more preferable because light interference fringes are difficult to see. In addition, the hard coat layer mentioned here is only required to have a high hardness, excellent scratch resistance, and wear resistance, such as acrylic, urethane, melamine, organic silicate compound, silicone, metal oxide, etc. Can be configured. In particular, in terms of hardness and durability, further, in terms of curability and productivity, acrylic, particularly active ray curable acrylic composition, or thermosetting acrylic composition is preferable, More preferably, it is a thermosetting type. In the case of the thermosetting type, it is possible to complete the coating film curing simultaneously with the crystal orientation of the film by applying a hard coat coating solution to the laminated film before crystallization, stretching and heat treatment.

  The actinic ray curable acrylic composition and the thermosetting acrylic composition include a polyfunctional acrylate, an acrylic oligomer, or a reactive diluent, and other photoinitiators and photosensitizers as necessary. Further, a thermal polymerization initiator or a modifier may be added.

  When the typical thing of the acrylic composition which comprises a hard-coat layer is illustrated, the polyfunctional acrylate which has 3 (more preferably 4 or 5) or more (meth) acryloyloxy groups in 1 molecule, and its modified polymer, Specific examples include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylopropane tri (meth) acrylate, Pentaerythritol triacrylate hexanemethylene diisocyanate urethane polymer and the like can be used. These monomers can be used alone or in combination of two or more. In addition, commercially available polyfunctional acrylic compositions include Mitsubishi Rayon Co., Ltd. (trade name “Diabeam” series, etc.), Nagase Sangyo Co., Ltd. (trade name “Denacol” series, etc.), Shin-Nakamura Science Co., Ltd. (Trade name “NK ester” series, etc.), Dainippon Ink and Chemicals Co., Ltd. (trade name “UNIDIC”, etc.), Toagosei Chemical Industries, Ltd. (trade name “Aronix” series, etc.), Nippon Oil & Fats Co., Ltd. (“Blemmer” series, etc.), Nippon Kayaku Co., Ltd .; (trade name “KAYARAD” series, etc.), Kyoeisha Chemical Co., Ltd. (trade name “Light Ester” series, etc.), etc. Can be used. Various coating methods such as reverse coating method, gravure coating method, rod coating method, bar coating method, die coating method or spray coating method can be used as the coating means for the coating composition containing the composition for forming the hard coat layer. Etc. can be used.

  In the present invention, the pencil hardness of the hard coat layer is preferably HB or higher. More preferably, it is 2H or more. This is because when the pencil hardness is 2H or more, a sufficient hardness can be obtained and it can be sufficiently applied as a design property for a nameplate or a portable information terminal. In addition, pencil hardness represents the hardness of a coating film.

A polyethylene terephthalate or polyethylene naphthalate resin A in the laminated film of the present invention, Ru polyester der resin B comprises a spiro glycol. The polyester comprising spiroglycol refers to a copolyester copolymerized with spiroglycol, a homopolyester, or a polyester blended with them. Polyesters containing spiroglycol are preferable because the absolute value of the difference in SP value from polyethylene terephthalate or polyethylene naphthalate is 1.0 or less and the same basic skeleton is included, so that delamination hardly occurs. Here, the basic skeleton is a repeating unit constituting the resin. More preferably, the resin A is polyethylene terephthalate or polyethylene naphthalate, and the resin B is a polyester containing spiroglycol and cyclohexanedicarboxylic acid. If the resin B is a polyester comprising spiroglycol and cyclohexanedicarboxylic acid, the difference in the in-plane refractive index from polyethylene terephthalate or polyethylene naphthalate is increased, so that high reflectance is easily obtained. Moreover, since the glass transition temperature difference with polyethylene terephthalate or polyethylene naphthalate is small, delamination is difficult.

  In the laminated film of the present invention, it is also preferable that the resin A is polyethylene terephthalate or polyethylene naphthalate and the resin B is a polyester comprising cyclohexanedimethanol. The ester comprising cyclohexanedimethanol refers to a copolyester copolymerized with cyclohexanedimethanol, a homopolyester, or a polyester blended with them. Polyester comprising cyclohexanedimethanol is preferable because it has a small glass transition temperature difference from polyethylene terephthalate or polyethylene naphthalate, and is difficult to delaminate. More preferably, the resin B is an ethylene terephthalate polycondensate having a copolymerization amount of cyclohexanedimethanol of 15 mol% to 60 mol%. By doing so, the laminating accuracy in the thickness direction is improved, and peeling between layers is difficult to occur while having high reflection performance. An ethylene terephthalate polycondensate having a copolymerization amount of cyclohexanedimethanol of 15 mol% or more and 60 mol% or less adheres very strongly to polyethylene terephthalate. In addition, the cyclohexanedimethanol group has a cis or trans isomer as a geometric isomer, and a chair type or a boat type as a conformational isomer. It is difficult to cause tearing during film formation.

  In the laminated film of the present invention, the relative reflectance is preferably 30% or more in the wavelength band of 350 nm or more and 1000 nm or less. When the relative reflectance in the wavelength band of 350 nm or more and 1000 nm or less is 30% or more, it is possible to obtain a metal glossy film with high luminance. Also, the color change hardly occurs depending on the viewing angle. This is because the relative reflectance is also 30% or more on the higher wavelength side (700 nm or more) than visible light, so even if the reflection band is shifted to the lower wavelength side depending on the viewing angle, the relative reflectance in the visible light region. This is because 30% or more can be maintained. More preferably, the relative reflectance in the wavelength band of 400 nm to 1000 nm is 60% or more, and more preferably 80% or more. The higher the relative reflectance, the higher the brightness of the metallic tone.

  In addition, the laminated film of the present invention preferably has a stress of 150 MPa or less when the elongation in the film longitudinal direction and / or the width direction is 100% in a tensile test at 150 ° C. More preferably, it is 120 MPa or less. When the stress is 120 MPa or less, since the moldability is good, it becomes easy to form into an arbitrary shape in various moldings such as insert molding, in-mold molding, vacuum pressure molding, vacuum molding, and press molding. More preferably, the stress at 100% elongation is 90 MPa or less. In such a case, molding with a higher drawing ratio is possible. In order to set the tensile stress at 150 ° C. to 90 MPa or less, it is preferable that either the resin A or the resin B is an amorphous resin such as cyclohexanedimethanol or spiroglycol. In such a case, even after biaxial stretching, the layer using the amorphous resin is hardly oriented and crystallized, so that the tensile stress is low. Further, it is preferable that the layer thickness is 20 nm or less because the orientation is difficult to proceed even if the layer is stretched and the tensile stress is reduced.

  Further, the resin sheet of the present invention preferably has a maximum depth (R) of scratch processing of 0.01 μm or more and 5 μm or less. Within this range, it is possible to suppress a decrease in film strength before and after scratch processing. Considering the effect of scratch processing, ease of processing, etc., the maximum depth (R) is preferably 0.1 μm to 5 μm, more preferably 0.2 μm to 3 μm.

  Moreover, it is preferable that the scratch process of the resin sheet of this invention is a hairline tone. This is because hairline-like decoration materials are used in various applications such as automobile-related parts, various home appliances, and building products (parts).

  Moreover, it is preferable that the direction of the hairline of the hairline tone resin sheet of this invention is parallel with respect to a film longitudinal direction. The production of the laminated film and the hairline-like scratch processing can be performed continuously in one film-forming process (from casting to winding), so that productivity is improved.

  Moreover, it is preferable that the film thickness of the laminated | multilayer film of this invention is 10 micrometers or more. More preferably, it is 14 μm or more. If the film thickness is less than 10 μm, the strength of the original fabric may not be sufficient at the time of scratch processing, and the appearance of the scratch pattern is likely to vary at the time of processing, which may cause a problem that the design quality is not stable. Although it does not specifically limit as an upper limit, 350 micrometers or less are preferable when the softness | flexibility of a resin sheet and the reflective performance of a laminated film are considered.

  In addition, the laminated film of the present invention has an easy-adhesion layer, an easy-slip layer, a hard coat layer, an antistatic layer, an anti-abrasion layer, an antireflection layer, a color correction layer, an electromagnetic wave shielding layer, an ultraviolet absorption layer, a printing on the surface. Functional layers such as a layer, a transparent conductive layer, a gas barrier layer, a hologram layer, a release layer, an adhesive layer, and an adhesive layer may be formed.

  The decorative film of the present invention must include the laminated film. In addition to the resin sheet of the present invention, any one of a color absorbing layer that absorbs black and a color complementary to the reflection peak, a hard coat layer, a weather resistant layer (UV cut layer), a colored layer, an adhesive layer, and a base resin layer It is also preferable to comprise. Such a decorative film can be composed of an all-polymer and does not contain metal or heavy metal. Therefore, the decorative film has a small environmental load, is excellent in recyclability, and does not cause electromagnetic interference. More preferably, in order to make it possible to adjust the color of the decorative film, it is preferable to have a color absorption layer that absorbs black or a color complementary to the reflection peak.

  As the molded product of the present invention, in addition to the resin sheet of the present invention, a color absorbing layer that absorbs black or a color that is complementary to the reflection peak, a hard coat layer, a weather resistant layer, a colored layer, an adhesive layer, a base resin layer It is also preferable to comprise any of these. Such a molded body can be composed of an all polymer and does not cause electromagnetic interference.

Next, the preferable manufacturing method of the laminated | multilayer film of this invention is demonstrated below.
Two types of resins A and B are prepared in the form of pellets. If necessary, the pellets are pre-dried in hot air or under vacuum and supplied to an extruder. In the extruder, the resin heated and melted to a temperature equal to or higher than the melting point is made uniform in the amount of resin extruded by a gear pump or the like, and foreign matters and denatured resin are removed through a filter or the like.
The thermoplastic resin sent out from different flow paths using these two or more extruders is then sent into the laminating apparatus. As the laminating apparatus, a multi-manifold die, a field block, a static mixer, or the like can be used. Moreover, you may combine these arbitrarily. Here, in order to efficiently obtain the effect of the present invention, a multi-manifold die or a feed block capable of individually controlling the layer thickness for each layer is preferable. Furthermore, in order to control the thickness of each layer with high accuracy, a feed block provided with fine slits for adjusting the flow rate of each layer by electric discharge machining or wire electric discharge machining with a machining accuracy of 0.1 mm or less is preferable. At this time, in order to reduce nonuniformity of the resin temperature, heating by a heat medium circulation method is preferable. Moreover, in order to suppress the wall resistance in the feed block, the roughness of the wall surface is preferably 0.4 S or less, or the contact angle with water at room temperature is 30 ° or more. By using such an apparatus, high lamination accuracy is achieved, so that a laminated film having a reflection peak with a reflectance of 30% or more can be easily obtained.

Further, in order to have at least one reflection band where the relative reflectance is 30% or more, which is the first feature of the present invention, it is possible to alternately stack five or more A layers and B layers. is important. Further, the layer thickness of each layer needs to be designed so as to obtain a desired reflection band based on the following formula 1, and the in-plane average refractive index and the layer thickness are distributed within a range of 40% or less. Even if this occurs, it is acceptable. Moreover, in order that the reflectance of the reflection band which is a preferable aspect of the present invention is 60% or more, the number of stacked layers is preferably 25 or more. Moreover, in order that the reflectance of the reflection band which is a more preferable aspect of the present invention is 80% or more, the number of laminated layers is preferably 50 or more.
2 × (na · da + nb · db) = λ Equation 1
na: In-plane average refractive index of the A layer nb: In-plane average refractive index of the B layer da: Layer thickness (nm) of the A layer
db: Layer thickness of layer B (nm)
λ: main reflection wavelength (primary reflection wavelength)
In the present invention, in order to set the relative reflectance in the wavelength band from 350 nm to 1000 nm to 30% or more, the thickness of each layer is designed so that reflection occurs at least in the wavelength band from 350 nm to 1000 nm based on the above formula 1. There is a need. Furthermore, it is preferable to include at least a layer configuration in which the layer pair thickness gradually increases from one surface to the opposite surface. The reflectance is controlled by the difference in refractive index between the A layer and the B layer and the number of layers of the A layer and the B layer.

  As described above, it is important to have an optimum laminated structure according to the spectral characteristics of the reflective film to be designed, but in the present invention, these adjustments are made to a feed block having a fine slit corresponding to each wavelength band. It is particularly preferable to perform film formation.

  The molten laminate formed in the desired layer configuration in this way is then formed into a desired shape by a die and then discharged. And the sheet | seat laminated | stacked in the multilayer discharged | emitted from die | dye is extruded on cooling bodies, such as a casting drum, and is cooled and solidified, and a casting film is obtained. At this time, using a wire-like, tape-like, needle-like or knife-like electrode, it is brought into close contact with a cooling body such as a casting drum by electrostatic force and rapidly cooled and solidified, or from a slit-like, spot-like, or planar device. A method in which air is blown out and brought into close contact with a cooling body such as a casting drum and rapidly cooled and solidified, and a method in which the nip roll is brought into close contact with the cooling body and rapidly solidified is preferable.

  The casting film thus obtained is preferably biaxially stretched as necessary. Biaxial stretching refers to stretching in the longitudinal direction and the width direction. Stretching may be performed sequentially biaxially or simultaneously in two directions. Further, the film may be redrawn in the longitudinal and / or width direction. In particular, in the present invention, it is preferable to use simultaneous biaxial stretching from the viewpoint of suppressing in-plane orientation difference and suppressing surface scratches.

  First, the case of sequential biaxial stretching will be described. Here, stretching in the longitudinal direction refers to stretching for imparting molecular orientation in the longitudinal direction to the film, and is usually performed by a difference in peripheral speed of the roll, and this stretching may be performed in one step. Alternatively, a plurality of roll pairs may be used in multiple stages. Although it changes with kinds of resin as a magnification of extending | stretching, 2 to 15 times is preferable normally, and when polyethylene terephthalate is used for either of the resin which comprises a laminated | multilayer film, 2 to 7 times are used especially preferably. Moreover, as extending | stretching temperature, the glass transition temperature-glass transition temperature +100 degreeC of resin which comprises a laminated | multilayer film are preferable.

  The uniaxially stretched film thus obtained is subjected to surface treatment such as corona treatment, flame treatment, and plasma treatment as necessary, and then hard coat properties, slipperiness, easy adhesion properties, and antistatic properties. Such functions may be imparted by in-line coating.

  The stretching in the width direction refers to stretching for giving the film an orientation in the width direction. Usually, the tenter is used to convey the film while holding both ends of the film with clips, and the film is stretched in the width direction. Although it changes with kinds of resin as a magnification of extending | stretching, 2 to 15 times is preferable normally, and when polyethylene terephthalate is used for either of the resin which comprises a laminated | multilayer film, 2 to 7 times are used especially preferably. Moreover, as extending | stretching temperature, the glass transition temperature-glass transition temperature +120 degreeC of resin which comprises a laminated | multilayer film are preferable.

  The biaxially stretched film is preferably subjected to a heat treatment at a temperature not lower than the stretching temperature and not higher than the melting point in the tenter in order to impart flatness and dimensional stability. After being heat-treated in this way, it is gradually cooled down uniformly, then cooled to room temperature and wound up. Moreover, you may use a relaxation process etc. together in the case of annealing from heat processing as needed.

  Next, the case of simultaneous biaxial stretching will be described. In the case of simultaneous biaxial stretching, a difference in reflectance between reflection peaks in the width direction can be easily adjusted to ± 10% or less, which is preferable. In the case of simultaneous biaxial stretching, the obtained cast film is subjected to surface treatment such as corona treatment, flame treatment, and plasma treatment as necessary, and then hard coat properties, slipperiness, easy adhesion properties, electrification Functions such as prevention may be imparted by in-line coating.

  Next, the cast film is guided to a simultaneous biaxial tenter, and conveyed while holding both ends of the film with clips, and stretched in the longitudinal direction and the width direction simultaneously and / or stepwise. As simultaneous biaxial stretching machines, there are pantograph method, screw method, drive motor method, linear motor method, but it is possible to change the stretching ratio arbitrarily and drive motor method that can perform relaxation treatment at any place or A linear motor system is preferred. Although the stretching magnification varies depending on the type of resin, it is usually preferably 6 to 50 times as the area magnification. When polyethylene terephthalate is used as one of the resins constituting the laminated film, the area magnification is 8 to 30 times. Is particularly preferably used. In particular, in the case of simultaneous biaxial stretching, it is preferable to make the stretching ratios in the longitudinal direction and the width direction the same and to make the stretching speeds substantially equal in order to suppress the in-plane orientation difference. Moreover, as extending | stretching temperature, the glass transition temperature-glass transition temperature +120 degreeC of resin which comprises a laminated | multilayer film are preferable.

  The film thus biaxially stretched is preferably subsequently subjected to a heat treatment not less than the stretching temperature and not more than the melting point in the tenter in order to impart flatness and dimensional stability. In order to suppress the distribution of the main alignment axis in the width direction during this heat treatment, it is preferable to perform a relaxation treatment in the longitudinal direction immediately before and / or immediately after entering the heat treatment zone. After being heat-treated in this way, it is gradually cooled down uniformly, then cooled to room temperature and wound up. Moreover, you may perform a relaxation | loosening process in a longitudinal direction and / or the width direction at the time of annealing from heat processing as needed. Immediately before and / or immediately after entering the heat treatment zone, a relaxation treatment is performed in the longitudinal direction.

  Next, the laminated film thus obtained is subjected to scratching. As a scratch processing method, a known technique can be applied, but in order to suppress heat generation due to the scratch processing, a cooling mechanism should be provided so that the film and the medium for applying the scratch should not be heated to 60 ° C. or higher. It is. As for the hairline-like scratch processing, a method of scratching a film by bringing the film into contact with a roll having a polishing file surface is preferable for obtaining a suitable appearance. The film may be wound into a roll after film formation, and then scratched while being rewound, or a polishing roll may be installed immediately after stretching the film and scratched. In consideration of productivity and cost, it is preferable to perform a scratch process by installing a polishing roll immediately after film stretching. Here, the polishing roll can be obtained, for example, by adhering and fixing a sandpaper to a metal roll without a gap. It is also possible to combine a plurality of them, and a more preferable appearance can be obtained by rotating in the same direction as the film running direction or in the opposite direction.

An evaluation method of physical property values used in the present invention will be described.
(Method for evaluating physical properties)
(1) The layer thickness of the laminated thickness and the number of laminated films was determined by observation with an electron microscope for a sample cut out of a cross section using a microtome. That is, using a transmission electron microscope H-7100FA type (manufactured by Hitachi, Ltd.), the cross section of the film was magnified 40000 times at an acceleration voltage of 75 kV, a cross-sectional photograph was taken, and the layer configuration and each layer thickness were measured. In some cases, in order to obtain high contrast, a staining technique using a known RuO ₄ or OsO ₄ may be used.
A specific method for obtaining the laminated structure will be described. About 40,000 times as many TEM photographic images were captured with CanonScan D123U at an image size of 720 dpi. The image is saved in the JPEG format, and then image processing software Image-Pro Plus ver. 4 (sales company Planetron Co., Ltd.) was used to open this JPG file and perform image analysis. In the image analysis process, the relationship between the thickness in the thickness direction and the average brightness of the area sandwiched between the two lines in the width direction was read as numerical data in the vertical thick profile mode. Using the spreadsheet software (Excel2000), the position (nm) and brightness data were subjected to numerical processing of sampling step 6 (decimation 6) and 3-point moving average. Furthermore, the data obtained by periodically changing the brightness is differentiated, and the maximum value and the minimum value of the differential curve are read by the VBA program. Calculated. This operation was performed for each photograph, and the layer thicknesses of all layers were calculated.

(2) Relative Reflectance A spectrophotometer (U-3410 Spectrophotometer) manufactured by Hitachi, Ltd. was fitted with a φ60 integrating sphere 130-0632 (Hitachi Ltd.) and a 10 ° inclined spacer, and the reflectance was measured. The band parameter was set to 2 / servo, the gain was set to 3, and the range from 187 nm to 2600 nm was set to 120 nm / min. Measured at a detection speed of In order to standardize the reflectance, an attached Al ₂ O ₃ plate was used as a standard reflecting plate. In Examples 2, 3, and 4 and Comparative Example 3, the maximum value of the relative reflectance at a wavelength of 250 to 2600 nm was shown, and the wavelength was taken as the reflection wavelength.

  In addition, Example 1, Example 5, Example 6, and Comparative Example 1. For Comparative Example 2 and Comparative Example 4, the average relative reflectance in the wavelength band of 350 nm to 1000 nm was shown.

(3) In-plane refractive index difference between different thermoplastic resins A single film was formed under the same film forming conditions as the laminated film, using the thermoplastic resin constituting the laminated film alone. In this case, the unstretched film was formed by the same method up to casting. Next, a sample was cut out from the unstretched film to a size of 10 cm × 10 cm, stretched at the same magnification as the laminated film using a biaxial stretching apparatus (Toyo Seiki Co., Ltd.), and the obtained stretched film was further stretched to 20 cm × 20 cm. A single film was obtained by applying heat treatment at the same temperature as the laminated film using a tunnel oven (manufactured by Taishin Co., Ltd.). In addition, when the heat treatment temperature at the time of film formation was a temperature at which the thermoplastic resin was melted, it was sandwiched by a support such as a polyimide film and subjected to heat treatment in a tunnel oven. A sample was cut out from the center of the obtained single film in the width direction of the film in a dimension of 4 × length 3.5 cm, and the refractive index of MD and TD was measured using an Abbe refractometer 4T (manufactured by Atago Co., Ltd.). Asked. As a light source, a sodium D line wavelength of 589 nm was used. The average refractive index of MD and TD was determined as the in-plane refractive index, and the difference in in-plane refractive index between different thermoplastic resins was determined as the in-plane refractive index difference (absolute value) (| surface of thermoplastic resin A Internal refractive index—In-plane refractive index of thermoplastic resin B |). As the immersion liquid, methylene iodide and a test piece having a refractive index of 1.74 were used.

(4) Solution viscosity (IV)
It calculated from the solution viscosity measured at 25 degreeC in orthochlorophenol. The solution viscosity was measured using an Ostwald viscometer. The unit is [dl / g]. The n number was 3, and the average value was adopted.

(5) Strong elongation According to the method defined in JIS-K7127 (1999), the elongation was measured using an Instron type tensile tester. The measurement was performed under the following conditions.
Measuring device: “Tensilon AMF / RTA-100” automatic tensile strength measuring device manufactured by Orientec Co., Ltd.
Sample size: width 10mm x test length 50mm
Pulling speed: 300mm / min
Measurement environment: temperature 23 ° C., humidity 65% RH.

(6) Peel test A test was conducted according to JIS K5600 (2002). The film was regarded as a hard substrate, and 25 lattice patterns were cut at intervals of 2 mm. Further, a tape cut to a length of about 75 mm was adhered to the lattice portion, and the tape was peeled off at an angle close to 60 ° in a time of 0.5 to 1.0 seconds. Here, Sekisui's cello tape (registered trademark) no. 252 (width 18 mm) was used. The evaluation results were expressed as the number of gratings in which one grid was completely peeled or partly peeled.

(7) Maximum depth of scratch processing (R)
In accordance with the method defined in JIS-B0601 (1982), the maximum height (Rma) was measured using a three-dimensional fine shape measuring instrument, and this was taken as the maximum depth for scratching. The measurement conditions were as follows.
Measuring device: Three-dimensional fine shape measuring instrument “ET-30HK” manufactured by Kosaka Laboratory Ltd.
Three-dimensional roughness analyzer “SPA-11”
Measurement area: 0.3mm ²
Sampling pitch: 4 μm in the film longitudinal direction and 10 μm in the width direction
Tilt correction: Yes.

(8) Glass transition temperature It measured and calculated according to JIS-K-7122 (1987) using differential calorimetry (DSC). First, at 1st Run, 20 ° C./min. From 25 ° C. to 300 ° C. And then cooled rapidly to 25 ° C. In the 2nd Run that follows, from 20 ° C to 300 ° C, 20 ° C / min. The temperature was raised. As the glass transition temperature of the resin, the glass transition temperature at 2nd Run was used.
Equipment: “Robot DSC-RDC220” manufactured by Seiko Electronics Industry Co., Ltd.
Data analysis "Disc Session SSC / 5200"
Sample mass: 5 mg.

(9) Solvent resistance A test was conducted according to JIS-K7114 (2001). The test temperature was 23 ° C., the immersion time was 1 hour, and the peel test was performed before immersion and after removal from the test solution. For the peel test, when one of the lattices was completely peeled or partly peeled, the number of lattices was 0, the case of 1 to 3, the case of 4 to 5, the number of 6 or more being x.
The solvents used were 2N aqueous sodium hydroxide, 2N aqueous hydrochloric acid, methyl ethyl ketone, and ethyl acetate.

  The peel test was conducted according to JIS K5600 (2002). The film was regarded as a hard substrate, and 25 lattice patterns were cut at intervals of 2 mm. Further, a tape cut to a length of about 75 mm was adhered to the lattice portion, and the tape was peeled off at an angle close to 60 ° in a time of 0.5 to 1.0 seconds. Here, Sekisui's cello tape (registered trademark) no. 252 (width 18 mm) was used.

Next, although this invention is demonstrated based on an Example, this invention is not necessarily limited to these.
<Coating agent A>
Dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate mixture (KAYAEAD-DPHA: manufactured by Nippon Kayaku Co., Ltd.) 80 parts by weight, trimethylpropane / ethylene oxide modified triacrylate (M-350: manufactured by Toagosei Co., Ltd.) 10 Parts by weight, 5 parts by weight of N-vinylpyrrolidone, 5 parts by weight of fully alkylated melamine (Cymel C350: manufactured by Nippon Cytec Industries, Inc.), dimethanolamine salt of dodecylbenzenesulfonate (CYCAT602: Nippon Cytec Industries, Inc.) A mixed coating composition was prepared by adding 1.0 part by weight to 100 parts by weight of melamine.

Example 1
Resin A and Resin B were prepared as two types of resins. In Example 1, polyethylene terephthalate (PET) [Toray F20S] having an intrinsic viscosity of 0.65 was used as the resin A. The resin A was a crystalline resin. Further, a copolymer of polyethylene terephthalate having an intrinsic viscosity of 0.55 (polyethylene terephthalate copolymerized with 20 mol% cyclohexanedicarboxylic acid component and 15 mol% spiroglycol component (CHDC20 mol% / SPG 15 mol% copolymerized PET)) was used as resin B. These resins were used. A and B were each dried and then fed to separate extruders.

  Resins A and B were each melted at 270 ° C. with an extruder, passed through 5 sheets of FSS type leaf disk filters, and then discharged at a gear pump with a thermoplastic resin A composition / thermoplastic resin B composition. While being measured so that the object = 1.2 / 1, the 801 layer feed block having a configuration using three slit plates with 267 slits was joined, and 801 layers were alternately stacked in the thickness direction. A laminated body was obtained. In the feed block, the merged resins A and B are changed so that the thickness of each layer gradually increases from the surface side toward the opposite surface side, and the thickness direction in which the resin A is 401 layers and the resin B is 400 layers. It was set as the structure laminated | stacked alternately. Moreover, the slit shape was designed so that both surface layer parts might be resin A, and the layer thickness of the adjacent A layer and B layer might become substantially the same. In this design, a reflection band exists between 350 nm and 1000 nm. The thus obtained laminate comprising 801 layers is supplied to a multi-manifold die, and further, a layer made of resin A supplied from another extruder is formed on the surface layer, and after forming into a sheet shape, Rapid solidification was effected on a casting drum maintained at a surface temperature of 25 ° C. by application of electricity. The flow path shape and the total discharge amount were set so that the time from when the resin A and the resin B merged to when rapidly solidified on the casting drum was about 8 minutes.

  The obtained cast film was heated with a roll group set at 75 ° C., and then stretched 3.0 times in the longitudinal direction while rapidly heating from both sides of the film with a radiation heater between 100 mm in the stretch section length. Cooled down. Next, this uniaxially stretched film was led to a tenter, preheated with hot air at 100 ° C., and stretched 3.3 times in the transverse direction at a temperature of 110 ° C. The stretched film was directly heat-treated with hot air at 230 ° C. in a tenter, subsequently subjected to a relaxation treatment of 5% in the width direction at the same temperature, and then gradually cooled to room temperature and wound up. The thickness of the obtained film was 91.7 μm. The obtained laminated film is scratched by running a plastic film while contacting a polishing roll in which a No. 600 sandpaper is attached to a metal roll with no gaps, and a resin sheet having a hairline having a maximum depth of 3 μm is obtained. It was. The obtained resin sheet was a resin sheet having no metallic delamination, excellent solvent resistance, and high metallic gloss. Also, the color change hardly occurred depending on the viewing angle, and because no metal was used, no electromagnetic interference was caused and the recyclability was excellent. The obtained results are shown in Table 1.

(Example 2)
In Example 1, the resins A and B were each melted at 270 ° C. with an extruder, passed through 5 sheets of FSS type leaf disk filters, and then discharged with a gear pump with a thermoplastic resin A composition / Thermoplastic resin B composition = 1.2 / 1 while being weighed so as to merge with a feed block having 201 fine slits, alternating in the thickness direction consisting of 101 layers of resin A and 100 layers of resin B It was set as the structure laminated | stacked on. The slit shape of the feed block was 45% (slit area on the thermoplastic resin non-supply side) / (slit area on the supply side), and the slit length was 100 mm. Both surface layer portions were made of resin A. The thickness of each layer is adjusted by the gap between fine slits (formed at a processing accuracy of 0.01 mm) in the feed block and the discharge amount of each resin, and the thickness ratio of the adjacent A layer and B layer (A layer thickness / B The layer thickness was 1.98. The laminate composed of a total of 201 layers thus obtained was supplied to a T-die and formed into a sheet shape (draft ratio 10), and then applied with static electricity (DC voltage 8 kV) using a tape-like electrode. And rapidly solidified on a casting drum kept at a surface temperature of 25 ° C.

  The obtained cast film was heated with a roll group set at 75 ° C., then stretched 3.0 times in the machine direction while rapidly heating from both sides of the stretch section with a radiation heater between 100 mm in length, and then cooled once. did. Next, the film was guided to a tenter, preheated with hot air at 90 ° C., and then stretched 6.0 times in the width direction. The stretched uniaxially stretched film was directly heat-treated with hot air at 230 ° C. in the tenter, subsequently subjected to a relaxation treatment of 5% in the width direction at the same temperature, and then cooled to room temperature and wound up. . The thickness of the obtained film was 100 μm. The film was scratched in the same manner as in Example 1 to obtain a resin sheet having a hairline having a maximum depth of 2.8 μm. The obtained resin sheet had no delamination, was excellent in solvent resistance, and was a resin sheet having high design properties. The results are shown in Table 1.

(Example 3)
In Example 2, film forming and scratching were performed under the same conditions as in Example 2 except that the feed block was changed to 51 layers. The thickness of the obtained laminated film was 100 μm, and the maximum depth of scratch processing was 3 μm. The obtained resin sheet had no delamination, was excellent in solvent resistance, and had a reflectance of 70%. The results are shown in Table 1.

Example 4
In Example 2, film formation and scratching were performed under the same conditions as in Example 2 except that the feed block was changed to 33 layers. The thickness of the obtained laminated film was 60 μm, and the maximum depth of scratch processing was 3.2 μm. The obtained resin sheet had no delamination and was excellent in solvent resistance. Since the number of laminated layers was reduced, the gloss was high but the reflectance was as low as 32%. The results are shown in Table 1.

( Reference Example 1 )
In Example 1, polyethylene terephthalate (CHDM copolymerized PET) obtained by copolymerizing 30 mol% of cyclohexanedimethanol with respect to ethylene glycol as resin B (PETG6763 manufactured by Eastman) and polyethylene terephthalate having an intrinsic viscosity of 0.65 by weight of 85:15 The film was formed and scratched under the same conditions as in Example 1 except that a resin kneaded and alloyed with a twin-screw extruder was used. The thickness of the obtained laminated film was 63 μm, and the maximum depth for scratching was 4.1 μm. The obtained resin sheet had no delamination, was excellent in solvent resistance, and had a reflectance of 63%. The results are shown in Table 1.

( Reference Example 2 )
In Example 1, except that the resin B was a polyethylene terephthalate copolymer (PET / I) obtained by copolymerizing 25 mol% of isophthalic acid with respect to terephthalic acid, film formation and scratching were performed under the same conditions as in Example 1. Went. The thickness of the obtained laminated film was 63 μm, and the maximum depth of the scratch processing was 3.2 μm. The obtained resin sheet had no delamination and was excellent in solvent resistance, but the reflectance was somewhat low at 35%. The results are shown in Table 1.

(Example 7)
After longitudinal stretching in the film forming process of Example 1, both surfaces of the film were subjected to corona discharge treatment in the air, and the above-mentioned coating agent A was applied to the surface of the laminated film to a thickness of 20 μm by the metabar method. Next, the film coated with coating agent A was guided to a tenter, preheated with hot air of 90 ° C., and stretched 3.3 times in the transverse direction at a temperature of 100 ° C. The stretched film was directly heat-treated in a tenter with hot air at 220 ° C., then subjected to a relaxation treatment of 5% in the width direction at the same temperature, and then gradually cooled to room temperature and wound up. The thickness of the laminated film was 91.7 μm, the hard coat layer was 5 μm, and a resin sheet having a layer thickness of 96.7 μm was obtained. The obtained resin sheet is scratched by running a plastic film while contacting a polishing roll in which a 600th sandpaper is bonded to a metal roll with no gaps to obtain a resin sheet having a hairline having a maximum depth of 3 μm. It was. The obtained resin sheet had no delamination, was excellent in abrasion resistance, scratch resistance, and solvent resistance, and had a high metallic gloss tone with high reflectivity. Also, the color change hardly occurred depending on the viewing angle, and because no metal was used, no electromagnetic interference was caused and the recyclability was excellent. The obtained results are shown in Table 1.

(Comparative Example 1)
A plastic film having a total thickness of 18 μm is formed by co-extrusion of a 15 μm polyethylene terephthalate layer, a 3 micron terephthalic acid and a copolymer polyester resin layer composed of ethylene glycol / 1,4-cyclohexanedimethanol (50/50 mol%). Obtained. The copolyester resin surface is scratched by running a plastic film while making contact with a polishing roll with 320 sandpaper affixed to a metal roll with no gaps, and a hairline with a maximum depth of 1.5 μm is applied. After that, metal aluminum was deposited in a thickness of about 500 angstroms by induction heating in vacuum. On this surface, a vinyl chloride copolymer consisting of 70% by weight of vinyl chloride / 30% by weight of vinyl acetate diluted with a solvent of 1: 1 weight ratio of toluene / methyl ethyl ketone is uniformly applied so that the film thickness after drying becomes 2 μm. By doing so, a metallic decorative sheet was obtained. Although the obtained sheet had a high reflectance, the interlayer adhesion was poor and peeling occurred in the peeling test. Moreover, since metal is used, it has electromagnetic wave shielding properties and cannot be recycled.

(Comparative Example 2)
A metal-deposited plastic film obtained in the same manner as in Comparative Example 1 was subjected to film formation and scratching under the same conditions except that it did not have a protective layer made of a vinyl chloride copolymer. Although the obtained sheet had a high reflectance, the correlation adhesion was poor and peeling occurred in the peeling test. Moreover, the solvent resistance in HCl aqueous solution and NaOH aqueous solution also fell. In addition, because it uses metal, it has electromagnetic shielding properties and cannot be recycled.

(Comparative Example 3)
In Example 2, the laminating apparatus was designed by discharge wire machining with a machining accuracy of 0.2 mm, the feed block having nine fine slits with a flow path surface roughness of 2.0 S, and the total cross-sectional area of the flow path was 200 mm 3. Three stages of a square mixer with a length of 30 mm and a joining plate were used, and the thermoplastic resin B was polyethylene terephthalate (PET / I 17.5 mol%) obtained by copolymerizing 17.5 mol% of isophthalic acid with terephthalic acid having an intrinsic viscosity of 0.67. The conditions were the same as in Example 2 except for the above. The thickness of the obtained laminated film was 14 μm and the number of laminated layers was 129 layers, but the lamination accuracy was insufficient. The obtained results are shown in Table 2. The resulting film has no reflection peak and even the highest reflectance is 25%. Moreover, since the scratch maximum depth (R) is deeper than the surface layer thickness, the interlayer adhesion and solvent resistance are low and the practical level has not been reached.

(Comparative Example 4)
In Example 1, the same conditions as in Example 1 were used except that the maximum depth of scratch processing was 3 μm and the relationship between the surface layer thickness and the maximum depth of scratch processing was L <R. The obtained film had a thickness of 100 μm and a surface layer thickness of 0.16 μm. The results are shown in Table 2. Although the reflectance of the obtained film was high, since the maximum scratch depth (R) was deeper than the surface layer thickness, interlayer adhesion and solvent resistance were low, and the practical level was not reached.

  TECHNICAL FIELD The present invention relates to a resin sheet having a solvent resistance that is continuously scratched on a laminated film capable of selectively reflecting light of a specific wavelength, has excellent moldability, has no delamination, and is resistant to solvent. Further, the present invention relates to a decorative film that has a low environmental load, is excellent in recyclability, and does not cause electromagnetic interference.

Claims (12)

Including a structure in which 5 layers or more of layers made of resin A which is polyethylene terephthalate or polyethylene naphthalate (layer A) and layers of resin B which is polyester containing spiroglycol (B layer) are alternately laminated,
On the surface of the laminated film having at least one reflection band having a relative reflectance of 30% or more,
A resin sheet subjected to scratch processing that satisfies the relationship L> R.
L: Thickness of the outermost layer on the side subjected to scratching R: Maximum depth of scratching The resin sheet according to claim 1, wherein a hard coat layer is provided on at least one surface of the laminated film, and the hard coat layer is scratched. The resin sheet according to claim 2 , wherein the hard coat layer is a thermosetting type. The resin sheet according to any one of claims 1 to 3, wherein the laminated film has a relative reflectance of 30% or more in a wavelength band of 350 nm or more and 1000 nm or less. The resin sheet according to any one of claims 1 to 4 , wherein the resin A is polyethylene terephthalate or polyethylene naphthalate, and the resin B is a polyester comprising spiroglycol and cyclohexanedicarboxylic acid. The resin sheet according to any one of claims 1 to 5 , wherein a stress when the elongation in the longitudinal direction and / or the width direction of the laminated film at 150 ° C is 100% is 150 MPa or less. The resin sheet according to any one of claims 1 to 6 , wherein the maximum depth (R) of scratch processing is 0.01 µm or more and 5 µm or less. The resin sheet according to any one of claims 1 to 7 , wherein the scratch processing is a hairline tone. The resin sheet according to claim 8 , wherein the direction of the hairline is parallel to the longitudinal direction of the film. Resin sheet according to any one of claims 1 to 9, the film thickness of the laminated film is characterized in that at 10μm or more. Decorative films using resin sheet according to claim 1 1 0. Molded using the resin sheet according to claim 1 1 0.