JP2018104536A - Film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-reflecting film that is wide and has a small variation in coloring in the film width direction.SOLUTION: A film has a width of 1000 mm or more. In the width direction, the difference between the maximum and minimum b values is 0.5 or less; in a wavelength range from 380 nm to 780 nm, the average transmittance is 50% or more, and in a wavelength range from 850 nm to 1200 nm, the average reflectance is 60% or more.SELECTED DRAWING: None

Description

  The present invention relates to a film having a small variation in color in the film width direction in a wide film.

In recent years, under the restriction of carbon dioxide emission due to environmental protection, heat ray reflective glass that can suppress heat inflow due to sunlight, particularly in the summer, has attracted attention as vehicles such as trains and window glass of buildings. As an example of a combination of heat ray reflective glasses, a laminated glass having a polymer multilayer laminated heat ray reflective film in which polymers having different refractive indexes are alternately laminated is known (for example, Patent Document 1). While the spread of heat ray reflective films used for these heat ray reflective glasses is progressing, in recent years, the application to larger glass has become a problem, and in particular, there is a demand for films with small variations in color in the film width direction. ing. So far, a film with small variation in color in the width direction of the film has been disclosed in a film deposited with an inorganic oxide described in Patent Document 2, and b ^* value variation in the width direction has been achieved within ± 3.0. ing.

Japanese Patent No. 4310312 JP 2003-285387 A

In the technique described in Patent Document 2, the temperature and humidity at the time of vapor deposition are controlled to finish the vapor deposited film into a dense one, thereby controlling the gas barrier performance and variation in color, but it is limited to the vapor deposited film. It is a technology and cannot be applied to films other than vapor-deposited films. Since the vapor-deposited film does not have radio wave permeability, there is a problem that it cannot be used for applications that require radio wave transparency, for example, applications that are used in combination with glass (such as architectural glass applications).

  The object of the present invention is to improve the drawbacks of the prior art and to provide a wide film having a small color variation in the film width direction.

In order to solve the above problems, the present invention has the following configuration.
(1) A film having a film width of 1000 mm or more, wherein the difference between the maximum and minimum b ^* values in the width direction is 0.5 or less, and the average transmittance at wavelengths of 380 nm to 780 nm is 50% or more. A film having an average reflectance of 60% or more at a wavelength of 850 nm to 1200 nm.
(2) The film according to (1), wherein the difference between the maximum value and the minimum value of the thickness at the center portion in the width direction and the end portion in the width direction is 0.5 μm or more and 5.0 μm or less.
(3) The film according to (1) or (2), wherein the average b ^* value in the width direction is 3 or less.
(4) The film according to any one of (1) to (3), which is a laminated film having 50 or more layers.
(5) The film according to any one of (1) to (4), which is used in combination with glass.

According to the present invention, the film has a film width of 1000 mm or more, the difference between the maximum value and the minimum value of the b ^* value in the width direction is 0.5 or less, and the average transmittance at a wavelength of 380 nm to 780 nm is 50% or more. In addition, when the film has an average reflectance of 60% or more at a wavelength of 850 nm to 1200 nm, a film with small variation in color in the film width direction can be obtained.

The color matching function for a 2 ° field of view is shown.

The film of the present invention is a film having a film width of 1000 mm or more, and it is important that the difference between the maximum value and the minimum value of b ^* values in the width direction is 0.5 or less. The b ^* value is strongly related to the zet bar (blueness stimulus sensitivity, see FIG. 1), which is the stimulus value of 380 nm to 550 nm in the color matching function of the 2 ° field of view shown by the CIE (International Commission on Illumination). . That is, when the reflectance in the wavelength band of 380 nm to 550 nm is increased, the b ^* value is increased, and the coloring due to the reflected color (blue purple) is increased. That is, in order to suppress the colored variation in the width direction, it is preferable that the variation of the b ^* value is small. The difference between the maximum value and the minimum value of the b ^* value in the width direction is preferably as low as possible from the viewpoint of further improvement of coloring in the width direction, more preferably 0.4 or less, and even more preferably 0.3 or less. Particularly preferably, it is 0.2 or less, and most preferably 0.1 or less. If the difference between the maximum value and the minimum value of the b ^* value in the width direction is larger than 0.5, the variation in color in the width direction becomes large, and a film having a small target color variation cannot be achieved.

  The film of the present invention is not particularly limited as long as the effect of the present invention is not impaired, but from the viewpoint of further improvement of the colored variation in the width direction, the value of the reflectance (%) at each wavelength (5 nm interval) in 380 nm to 550 nm and It is preferable that the sum of the products of the stimulus values at the respective wavelengths (5 nm intervals) of 380 nm to 550 nm in the color matching function be a uniform value in the width direction. Maximum sum of products of stimulation values of wavelengths (380 nm to 550 nm) of each wavelength (5 nm interval) and reflectance values (%) of each wavelength (5 nm interval) at 380 nm to 550 nm of each width in the film width direction The difference between the value and the minimum value is preferably 50 or less, more preferably 30 or less, further preferably 15 or less, particularly preferably 5 or less, and most preferably 3 or less. A detailed calculation method will be described later.

The film of the present invention is not particularly limited as long as the effects of the present invention are not impaired, but from the viewpoint of reducing the coloration of the film itself, the average value of b ^* values in the width direction is preferably 3 or less. It is more preferably 5 or less, further preferably 2 or less, particularly preferably 1.5 or less, and most preferably 1.0 or less.

In the film of the present invention, the method for achieving the difference between the maximum value and the minimum value of the b ^* value in the width direction of 0.5 or less is not particularly limited. For example, the thickness of the film is changed in the width direction. There is a way to make adjustments. When adjusting the b ^* value variation by adjusting the film thickness, the reflectance (%) of each wavelength (5 nm interval) of each width in the film width direction from 380 nm to 550 nm is 380 nm to 550 nm in the color matching function. The total value of the products of the stimulation values of the respective wavelengths (5 nm intervals) may be calculated, and the thickness of the corresponding portion may be adjusted as appropriate so that this value falls within the above-described preferable value range. As a method for adjusting the thickness of the film at the corresponding position in the width direction, for example, in the film casting process, the die die bolt can be mechanically and thermally operated to change the die lip interval. It is also effective to change the stretchability by locally applying heat using a radiation heater or the like in the stretching step.

The film of the present invention preferably has a layer that absorbs or reflects light in the wavelength region of 380 nm to 550 nm. As a means to provide a layer that absorbs or reflects light in the wavelength region of 380 nm to 550 nm, a color pigment (for example, a yellow pigment or a blue pigment) is added as a coating layer, and inline coating or offline coating is performed. And a method of laminating with a film having a colored pigment (for example, a yellow pigment or a blue pigment). When a layer that absorbs or reflects light in the wavelength region of 380 nm to 550 nm is provided to adjust the variation in the b ^* value in the width direction, each wavelength in the film width direction at 380 nm to 550 nm (5 nm The total value of the product of the stimulation value of each wavelength (5 nm interval) of 380 nm to 550 nm in the color matching function and the reflectance (%) value of the (interval) is calculated, and this value falls within the preferable value range described above. What is necessary is just to adjust the thickness of the coating layer of the applicable part suitably, and the thickness of the film which has the color pigment (for example, yellow pigment and blue pigment) to laminate.
As a method for adjusting the variation in the b ^* value in the width direction, a single method may be used, or several methods may be combined.

In addition, the film of the present invention tends to have large variations in color between the center and the end, particularly when the film is widened. This is considered to be due to a difference in the fluidity of the molten polymer in the die in the film casting process. From the viewpoint of further improving the variation in color in the width direction of the widened film, it is preferable that the difference between the maximum value and the minimum value of the thickness at the center and end in the width direction is 0.5 μm or more and 5.0 μm or less. 1.0 μm or more and 5.0 μm or less is more preferable, 1.5 μm or more and 5.0 μm or less is more preferable, 2.5 μm or more and 5.0 μm or less is particularly preferable, and 3.5 μm or more is preferable. Most preferably, it is 5.0 μm or less. If the difference between the maximum value and the minimum value of the thickness at the center and the end in the width direction is smaller than 0.5 μm, the effect of controlling the variation in b ^* value may not be obtained sufficiently for a film width of 1000 mm or more. If it is larger than 5.0 μm, it may be unfavorable from the viewpoint of the handling property and winding property of the film.

  The film width of the film of the present invention is important to be 1000 mm width or more in consideration of application to an enlarged glass. In consideration of application of a film that suppresses color variation in the width direction to a larger glass, the film width is preferably 1200 mm or more, more preferably 1500 mm or more, and further preferably 2000 mm or more. . When the film width is less than 1000 mm, it is difficult to apply to an enlarged glass. Although there is no upper limit to the film width, the realistic film width that can be manufactured is about 10,000 mm.

  In the film of the present invention, it is important that the average transmittance at a wavelength of 380 nm to 780 nm is 50% or more. Since the region of wavelength 380 nm to 780 nm is a visible light region where humans can sense light, the average transmittance of wavelength 380 nm to 780 nm is 50% or more, and thus, for applications such as building materials that require high transparency. It can be set as a suitable film. The average transmittance at a wavelength of 380 nm to 780 nm is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, and particularly preferably 90% or more. The higher the average transmittance at wavelengths of 380 nm to 780 nm, the higher the transparency.

  In the film of the present invention, it is important that the average reflectance at a wavelength of 850 nm to 1200 nm is 60% or more. Sunlight has an intensity distribution mainly in the visible light region, and the intensity distribution tends to decrease as the wavelength increases. However, the film of the present invention can hardly shield sunlight in the visible light region for use in applications requiring high transparency. Therefore, it is necessary to be able to provide high heat ray reflection performance by efficiently reflecting light having a wavelength of 850 nm to 1200 nm (about 18% of the intensity of total sunlight) slightly larger than the visible light region. is there. On the other hand, when the average reflectance at a wavelength of 850 nm to 1200 nm is less than 60%, the heat ray reflection performance becomes insufficient, which is not preferable. Preferably, the average reflectance at a wavelength of 850 nm to 1200 nm is 70% or more, more preferably the average reflectance at a wavelength of 850 nm to 1200 nm is 75% or more, and even more preferably, the average reflectance at a wavelength of 850 nm to 1200 nm. Is 80% or more, and an average reflectance at a wavelength of 850 nm to 1200 nm is particularly preferably 85% or more. As the average reflectance at a wavelength of 850 nm to 1200 nm increases, high heat ray reflection performance can be imparted.

  The film of the present invention is preferably made of a thermoplastic resin. Thermoplastic resins are generally cheaper than thermosetting resins and photocurable resins, and can be easily and continuously formed into films by known melt extrusion, so that films can be obtained at low cost. This is because it becomes possible.

  Further, the film of the present invention may be a single layer film or a laminated film as long as the effects of the present invention are not impaired, but at least two or more from the viewpoint of imparting heat ray reflection performance while maintaining high transparency. It is preferable that it is a laminated film in which 50 or more layers of thermoplastic resins having different optical properties are alternately laminated. The different optical properties referred to here mean that the refractive index is different by 0.01 or more in either of two orthogonal directions arbitrarily selected in the plane of the laminated film and a direction perpendicular to the plane. The term “alternately laminated” as used herein means that layers made of different resins are laminated in a regular arrangement in the thickness direction, for example, two thermoplastic resins A and B having different optical properties. When each layer is expressed as an A layer and a B layer, the layers are stacked in a regular arrangement of A (BA) n (n is a natural number). By alternately laminating resins with different optical properties in this way, it is possible to express interference reflection that can reflect the light of the designed wavelength from the relationship between the refractive index difference of each layer and the layer thickness. It becomes. Further, when the number of layers to be laminated is less than 50, it is not preferable because a high reflectivity cannot be obtained over a sufficient band in the infrared region and a sufficient heat ray reflection performance may not be obtained. Preferably, it is 400 layers or more, More preferably, it is 800 layers or more. As the number of layers increases, the above-described interference reflection can achieve a high reflectance with respect to light in a wider wavelength band, and a film having high heat ray reflection performance can be obtained. In addition, although there is no upper limit to the number of layers, as the number of layers increases, the manufacturing cost increases due to an increase in the size of the manufacturing apparatus, and the handling properties deteriorate due to the increase in film thickness, and in particular the film thickness increases. Then, since it may cause a process failure in the process of forming the laminated glass, in reality, about 10,000 layers are within the practical range.

  The thermoplastic resins used in the present invention are chain polyolefins such as polyethylene, polypropylene, poly (4-methylpentene-1), polyacetal, and ring-opening metathesis polymerization of norbornenes, addition polymerization, and addition copolymerization with other olefins. Biodegradable polymers such as alicyclic polyolefin, polylactic acid, and polybutyl succinate, polyamides such as nylon 6, nylon 11, nylon 12, and nylon 66, aramid, polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride , Polyvinyl alcohol, polyvinyl butyral, ethylene vinyl acetate copolymer, polyacetal, polyglycolic acid, polystyrene, styrene copolymer polymethyl methacrylate, polycarbonate, polypropylene terephthalate, polyethylene terephthalate Polyester, polybutylene terephthalate, polyethylene-2,6-naphthalate, etc., polyethersulfone, polyetheretherketone, modified polyphenylene ether, polyphenylene sulfide, polyetherimide, polyimide, polyarylate, tetrafluoroethylene resin, A trifluorinated ethylene resin, a trifluorinated ethylene resin, a tetrafluoroethylene-6 fluoropropylene copolymer, polyvinylidene fluoride, or the like can be used. Of these, polyester is particularly preferred from the viewpoint of strength, heat resistance, transparency and versatility. These may be a copolymer or a mixture.

  The polyester is preferably a polyester obtained by polymerization from a monomer mainly composed of an aromatic dicarboxylic acid or an aliphatic dicarboxylic acid and a diol. Here, as the aromatic dicarboxylic acid, for example, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyl Examples include dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, and the like. Examples of the aliphatic dicarboxylic acid include adipic acid, suberic acid, sebacic acid, dimer acid, dodecanedioic acid, cyclohexanedicarboxylic acid and ester derivatives thereof. Of these, terephthalic acid and 2,6 naphthalenedicarboxylic acid exhibiting a high refractive index are preferable. These acid components may be used alone or in combination of two or more thereof, and further may be partially copolymerized with oxyacids such as hydroxybenzoic acid.

  Examples of the diol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentanediol. 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis (4- Hydroxyethoxyphenyl) propane, isosorbate, spiroglycol and the like. Of these, ethylene glycol is preferably used. These diol components may be used alone or in combination of two or more.

  The thermoplastic resin of the present invention is, for example, among the above polyesters, polyethylene terephthalate and its polymer, polyethylene naphthalate and its copolymer, polybutylene terephthalate and its copolymer, polybutylene naphthalate and its copolymer, Furthermore, it is preferable to use polyhexamethylene terephthalate and its copolymer, polyhexamethylene naphthalate and its copolymer, and the like.

  When the film of the present invention is a laminated film, among the thermoplastic resins having different optical properties used for the laminated film, the difference in the in-plane average refractive index of each layer composed of at least two thermoplastic resins is 0.03 or more. It is preferable that More preferably, it is 0.05 or more, More preferably, it is 0.1-0.15. When the difference in the in-plane average refractive index is smaller than 0.03, sufficient reflectivity cannot be obtained, so that the heat ray reflection performance may be insufficient. As a method for achieving this, at least one thermoplastic resin is crystalline, and at least one thermoplastic resin is amorphous or a mixture of an amorphous thermoplastic resin and a crystalline thermoplastic resin. In this case, it is possible to easily provide a refractive index difference in the stretching and heat treatment steps in film production.

  When the film of the present invention is a laminated film, the preferred combination of the thermoplastic resins having different optical properties used in the laminated film is the absolute difference in SP values (also referred to as solubility parameters) of the thermoplastic resins. The value is preferably 1.0 or less. When the absolute value of the difference in SP value is 1.0 or less, delamination hardly occurs. More preferably, the polymers having different optical properties are preferably composed of a combination provided with the same basic skeleton. The basic skeleton here is a repeating unit constituting the resin. For example, when polyethylene terephthalate is used as one thermoplastic resin, it is the same as polyethylene terephthalate from the viewpoint of easily realizing a highly accurate laminated structure. It is preferable to contain ethylene terephthalate, which is the basic skeleton. When the thermoplastic resins having different optical properties are resins containing the same basic skeleton, the lamination accuracy is high, and delamination at the lamination interface is less likely to occur.

  Moreover, when the film of this invention is a laminated film, as a preferable combination of each thermoplastic resin which has a different optical property used for a laminated film, the glass transition temperature difference of each thermoplastic resin is 20 degrees C or less. Is preferred. When the difference in glass transition temperature is greater than 20 ° C., the thickness uniformity when the laminated film is formed becomes poor, which causes variations in heat ray reflection performance. Also, when a laminated film is formed, problems such as overstretching tend to occur.

  As an example of a combination of resins for satisfying the above conditions, when the film of the present invention is a laminated film, at least one thermoplastic resin used for the laminated film comprises polyethylene terephthalate or polyethylene naphthalate, and at least one The two thermoplastic resins are preferably polyesters comprising spiroglycol. The polyester comprising spiroglycol refers to a copolyester copolymerized with spiroglycol, a homopolyester, or a polyester blended with them. Polyesters containing spiroglycol are preferred because they have a small glass transition temperature difference from polyethylene terephthalate or polyethylene naphthalate, so that they are not easily stretched at the time of molding and are also difficult to delaminate. More preferably, at least one thermoplastic resin comprises polyethylene terephthalate or polyethylene naphthalate, and at least one thermoplastic resin is preferably a polyester comprising spiroglycol and cyclohexanedicarboxylic acid. In the case of a polyester comprising spiroglycol and cyclohexanedicarboxylic acid, the in-plane refractive index difference 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 and the adhesiveness is excellent, it is difficult to be over-stretched at the time of molding and is also difficult to delaminate.

  Further, when the film of the present invention is a laminated film, at least one thermoplastic resin used for the laminated film contains polyethylene terephthalate or polyethylene naphthalate, and even in a single composition, a small amount of other repeating units are present. It may be copolymerized or blended with small amounts of other polyester resins, and at least one thermoplastic resin is preferably a polyester comprising cyclohexanedimethanol. The polyester comprising cyclohexanedimethanol refers to a copolyester obtained by copolymerizing cyclohexanedimethanol, a homopolyester, or a polyester obtained by blending them. Polyesters containing cyclohexanedimethanol are preferred because they have a small glass transition temperature difference from polyethylene terephthalate or polyethylene naphthalate, so that they are unlikely to be overstretched during molding and are also difficult to delaminate. More preferably, at least one thermoplastic resin is an ethylene terephthalate polycondensate having a copolymerization amount of cyclohexanedimethanol of 15 mol% or more and 60 mol% or less. In this way, while having high heat ray reflection performance, the change in optical characteristics due to heating and aging is particularly small, and peeling between layers is less likely to occur. 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. The reflectance is such that the change in optical properties due to thermal history is even less, and blurring during film formation is less likely to occur.

  When the film of the present invention is a laminated film, at least one thermoplastic resin of thermoplastic resins having different optical properties used for the laminated film is a crystalline polyester (hereinafter referred to as crystalline polyester A). It is also preferable that the at least one thermoplastic resin is a polyester resin composed of amorphous polyester (hereinafter referred to as amorphous polyester B) and crystalline polyester (hereinafter referred to as crystalline polyester B). The crystallinity here means that the heat of fusion is 20 J / g or more in differential scanning calorimetry (DSC). On the other hand, the term “amorphous” means that the heat of fusion is 5 J / g or less. In the case of such a combination of resins, in addition to facilitating the provision of a difference in refractive index easily in the stretching and heat treatment steps in the production of the film, the melting point of the crystalline polyester B contained in the amorphous polyester B or less By performing the heat treatment at the heat treatment temperature, it is possible to control the orientation state of the crystalline polyester B in the amorphous polyester B and to increase the magnitude of the heat shrinkage. As a similar method, it is possible to use a crystalline or semi-crystalline polyester having a melting point lower than that of the crystalline polyester (referred to a polyester having a kidnapping calorific value larger than 5 J / g and smaller than 20 J / g). It is difficult to control the degree of melting of the resin. For example, when the heat treatment temperature is slightly low, the resin is not sufficiently melted, so that the magnitude of heat shrinkage can be increased, but the refractive index cannot be lowered sufficiently, and refraction with crystalline polyester A is not possible. In some cases, the rate difference cannot be given sufficiently. On the other hand, when the heat treatment temperature is slightly high, the resin melts sufficiently, so that a sufficient difference in refractive index from the crystalline polyester A can be imparted, but with the relaxation of the resin orientation, the thermal contraction is large. It may be difficult to increase the height. Also, for the layer made of crystalline polyester A, the degree of thermal shrinkage varies depending on the heat treatment temperature, but when using a resin made of crystalline polyester or semi-crystalline polyester as described above, In order to give sufficient heat ray reflection performance, a heat treatment temperature suitable for the melting behavior of the crystalline or semi-crystalline polyester must be selected, and the magnitude of the heat shrinkage derived from the crystalline polyester A can be sufficiently increased. There are cases where it is not possible. Thus, when the film of the present invention is a laminated film, when the reflection is induced by the difference in refractive index between the two kinds of laminated resins, the magnitude of heat shrinkage is increased while giving a sufficient refractive index difference. This is often difficult. On the other hand, when the amorphous polyester B and the crystalline polyester B are mixed and used, an alloy state in which the crystalline polyester B is finely dispersed in the amorphous polyester B is formed. The alloy state here refers to a state where the mixed amorphous polyester B and the crystalline polyester B are not completely compatible. For example, in the cross-sectional observation of the film, the amorphous or crystalline of 10 nm or more. It indicates a state in which the domain of the crystalline polyester can be confirmed, or the glass transition and the crystallization / melting peak derived from the amorphous polyester B and the crystalline polyester B can be observed in the DSC measurement. By forming an alloy state in this manner, the amorphous polyester B, which is less likely to be oriented in the stretching process and relaxed at the glass transition temperature or higher, retains the amorphous state regardless of the heat treatment temperature. A sufficient difference in refractive index from polyester A can be imparted. In addition, the crystalline polyester B forming the alloy state maintains the orientation provided in the stretching step up to the vicinity of the melting point, and the thermal shrinkage can be increased by controlling the orientation state. Thus, when amorphous polyester B and crystalline polyester B form an alloy state, by selecting a heat treatment temperature suitable for controlling the orientation state of crystalline polyester B, crystalline polyester A and It is possible to control the magnitude of thermal shrinkage while maintaining a sufficient refractive index difference. Similarly, the degree of thermal shrinkage of the crystalline polyester A can be controlled. Preferably, in the amorphous polyester B and the crystalline polyester B, the ratio of the amorphous polyester B is preferably 60% or more and 90% or less. When the ratio of the amorphous polyester B is larger than the ratio of the crystalline polyester B, the refractive index difference and the heat shrinkage behavior can be easily controlled, while the ratio of the amorphous polyester B is 90% or less, that is, the crystal When the ratio of the crystalline polyester B is 10% or more, the orientation control by the crystalline polyester B can be easily performed. Further, the size of the domain in the alloy state of the crystalline polyester B in the amorphous polyester B is preferably 100 nm or less. Since the amorphous polyester and the crystalline polyester have different refractive indexes, light scattering at the domain interface may occur and haze may increase as the domain size becomes larger than 100 nm. In order for the size of the alloyed domain of the crystalline polyester B in the amorphous polyester B to be 100 nm or less, only the refractive index difference from the polyester A and the size of the heat shrinkage are controlled without increasing the haze. It can be done.

  When the film of the present invention is a laminated film, the layer thickness of the laminated film is a thermoplastic resin having optical properties different from those of the thermoplastic resin A layer (A layer) and the thermoplastic resin A in particular. When layers made of B (B layers) are alternately stacked, the reflectance is determined according to the following formula 1. Usually, the laminated film used for this purpose is designed to reflect light having a wavelength of 850 to 1200 nm by designing the optical thickness ratio k defined by the following formula 2 to be 1. The secondary reflection of the laminated film is suppressed. Preferably, the layer having a large optical thickness is made of an amorphous thermoplastic resin. In this case, while imparting high heat ray reflection performance, it is possible to suppress the stress at the time of stretching generated in the curved surface portion of the glass in the process used in combination with glass, and suppress molding defects in the process used in combination with glass. It becomes possible.

2 × (na · da + nb · db) = λ Equation 1
| (Na · da) / (nb · db) | = k Equation 2
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)
k: Ratio of Optical Thickness Next, when the film of the present invention is a laminated film, a preferred production method of the laminated film will be described below by taking a laminated film made of thermoplastic resins A and B as an example. Of course, the present invention is not construed as being limited to such examples. Further, the formation of the laminated structure of the laminated film can be realized by referring to the description in paragraphs [0053] to [0063] of JP-A-2007-307893.

  A thermoplastic resin is prepared in the form of pellets. Here, in order to make amorphous polyester and crystalline polyester alloy, it is preferable to prepare pellets kneaded in advance by a twin screw extruder or the like. Here, the dispersion state of the crystalline polyester B can be controlled by selecting the screw of the twin-screw extruder, controlling the discharge amount and the number of rotations of the screw, the kneading temperature, and the like. The dispersion state can also be controlled by adding a suitable compatibilizer. Thus, by preparing pellets kneaded in advance with a twin screw extruder or the like, the dispersion state and domain size of the crystalline polyester B in the amorphous polyester can be controlled. The pellets are dried in hot air or under vacuum as necessary, and then supplied to a separate extruder. In the extruder, the resin melted by heating 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 matter or denatured resin is removed through a filter or the like. These resins are 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, it is preferable to use a wire-like, tape-like, needle-like, or knife-like electrode to be brought into close contact with a cooling body such as a casting drum by an electrostatic force and rapidly solidify. Also preferred is a method in which air is blown out from a slit-like, spot-like, or planar device to be brought into close contact with a cooling body such as a casting drum and rapidly cooled and solidified, or brought into close contact with a cooling body with a nip roll and rapidly solidified.

  Moreover, when producing the multilayer laminated film which consists of a some thermoplastic resin, several resin is sent out from a different flow path using two or more extruders, and is sent into a multilayer lamination apparatus. As the multi-layer laminating apparatus, a multi-manifold die, a feed block, a static mixer, etc. can be used. In particular, in order to efficiently obtain the configuration of the present invention, at least two members having a large number of fine slits are separately provided. It is preferable to use the feed block including the above. When such a feed block is used, since the apparatus does not become extremely large, there is little foreign matter due to thermal degradation, and high-precision lamination is possible even when the number of laminations is extremely large. Also, the stacking accuracy in the width direction is significantly improved as compared with the prior art. It is also possible to form an arbitrary layer thickness configuration. In this apparatus, since the thickness of each layer can be adjusted by the shape (length, width) of the slit, any layer thickness can be achieved.

  The molten multilayer laminate formed in the desired layer structure in this way is led to a die, and a casting film is obtained in the same manner as described above.

  The casting film thus obtained is preferably biaxially stretched as necessary. Here, biaxial stretching refers to stretching in the longitudinal direction and the width direction. Stretching may be performed sequentially in two directions or simultaneously in two directions. Further, re-stretching may be performed in the longitudinal direction and / or the width direction. In particular, in the present invention, it is possible to use simultaneous biaxial stretching from the viewpoint of suppressing in-plane orientation difference, suppressing surface scratches, and isotropic mechanical properties such as heat shrinkage behavior and storage elastic modulus. preferable.

  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. The stretching ratio varies depending on the type of resin, but usually 2 to 15 times is preferable, and when polyethylene terephthalate is used for any of the resins constituting the multilayer laminated film, 2 to 7 times is particularly preferably used. . Moreover, as extending | stretching temperature, the glass transition temperature-glass transition temperature +100 degreeC of resin which comprises a multilayer laminated 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 functions such as slipperiness, easy adhesion, and antistatic properties are provided. It may be applied 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 the both ends with clips and stretch 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. By performing the heat treatment, the dimensional stability of the film is improved. 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.

  In the film of the present invention, the heat treatment temperature after stretching is preferably not higher than the melting point of at least one thermoplastic resin and not lower than at least one melting point of the remaining thermoplastic resin. In this case, one of the thermoplastic resins maintains a high orientation state, while the orientation of the other thermoplastic resin is relaxed, so that the refractive index difference between these resins can be easily provided, and High thermoplastic shrinkage behavior can be imparted by the thermoplastic resin that maintains the orientation. When at least one thermoplastic resin is crystalline polyester A and at least one thermoplastic resin is a polyester resin composed of amorphous polyester B and crystalline polyester B, the heat treatment temperature may be crystalline. The polyester A and the crystalline polyester B or less are preferable. In this case, since the orientation of the crystalline polyester B is maintained in addition to the orientation of the crystalline polyester A, a higher heat shrinkage behavior can be imparted.

  In addition, since the above relaxation treatment is performed to suppress the heat shrinkage behavior, it is also preferable that the film of the present invention is not subjected to the relaxation treatment, and the preferable degree of the relaxation treatment is the level before the relaxation treatment. The ratio of the relaxation treatment with respect to the film width is 0% or more and 5% or less.

  Next, the case of simultaneous biaxial stretching will be described. In the case of simultaneous biaxial stretching, the resulting cast film is subjected to surface treatment such as corona treatment, flame treatment, and plasma treatment as necessary, and then, such as slipperiness, easy adhesion, antistatic properties, etc. The function 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, an example of a process using the film of the present invention in combination with glass will be described below. First, a resin film used as an intermediate film, a cut film of the present invention, a resin film used as an intermediate film, and the other glass are placed on glass, and then heated and pre-pressed in a 120 ° C. atmosphere for about 1 hour. Subsequently, this glass is bonded to hold it for 30 minutes in a pressurized and heated state up to 140 ° C. and 1.5 MPa to obtain a laminated glass. As the intermediate film used here, ethylene vinyl acetate (EVA), polyvinyl briral, etc. are mainly used, but are not particularly limited. Further, the glass may be flat glass and curved glass, but by using the film of the present invention, a heat ray reflective glass excellent in appearance with small variation in color in the width direction even in a large-sized glass. Can be obtained.

Although the film of this invention is not specifically limited unless the effect of this invention is impaired, In order to improve heat ray reflective performance, it is also preferable to provide a heat ray reflective layer on a film. As a method of providing the heat ray reflective layer, there is a method of providing a metal layer on the obtained film by sputtering or the like. When these heat ray reflective layers are provided, it is necessary to provide them with a thickness and concentration at which the visible light transmittance does not decrease too much, but by providing these layers, higher heat ray reflective performance can be imparted to the film. it can. In the glass combined with the film of the present invention, the difference between the maximum value and the minimum value of the b ^* value in the width direction is 0.5 or less from the viewpoint of improving coloring in the width direction at a glass width of 1000 mm or more. It is preferable. The difference between the maximum value and the minimum value of the b ^* value in the width direction is preferably as low as possible from the viewpoint of further improvement of coloring in the width direction. More preferably, it is 0.4 or less, More preferably, it is 0.3 or less, Especially preferably, it is 0.2 or less, Most preferably, it is 0.1 or less.

  Since the glass thus obtained has high transparency and excellent heat ray reflectivity, it can be suitably used for heat ray reflective glass used for trains, buildings, etc., and further has little variation in color in the width direction. It can be particularly suitably used for a large curved glass having a curvature.

Hereafter, it demonstrates using the Example of the film of this invention.
[Methods for measuring physical properties and methods for evaluating effects]
The characteristic value evaluation method and the effect evaluation method are as follows.

(1) Layer thickness, number of layers, layered structure The layer structure of the film was determined by observation with a transmission electron microscope (TEM) for a sample obtained by cutting a cross-section from the center in the film width direction 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 10000 to 40000 times under the condition of an acceleration voltage of 75 kV, a cross-sectional photograph was taken, the layer configuration and the thickness of each layer Was measured. In some cases, in order to obtain high contrast, a staining technique using a known RuO ₄ or OsO ₄ was used.

(2) Coating layer thickness In the film width direction, a sample was cut out at a size of 5 cm × 5 cm at intervals of 10 cm. Using a microtome, a small piece was cut by cutting the sample in a direction perpendicular to the surface of the film, and the cross section was increased 10,000 times using a field emission scanning electron microscope JSM-6700F (manufactured by JEOL Ltd.). Photographed by magnifying. From the cross-sectional photograph, the coating layer thickness at the center and both ends was calculated. As for the thickness of the end portion, the thicker one of the coating layer thicknesses at both end portions was defined as the thickness of the end portion.

(3) Film thickness In the film width direction, a sample was cut out with a size of 5 cm in the width direction × 5 cm in the longitudinal direction at intervals of 10 cm toward the center in the film width direction and then to both ends in the film width direction. The thickness of the sample was measured using a dial gauge thickness gauge (JIS B7503 (1997), UPAIGHT DIAL GAUGE (0.001 × 2 mm), No. 25, measuring element 5 mmφ flat type) manufactured by PEACOCK. The film thickness at the center and both ends was calculated. (For example, in the case of a film having a film width of 1100 mm, sample 1 is centered at the center in the film width direction, sample 2, and sample 3 is centered at 10 cm points from the center in the width direction toward both ends of the film. Sample 4 and sample 5, each centered at a point of 20 cm from the center in the width direction toward both ends in the film width direction, and each point of 30 cm from the center in the width direction toward both ends in the film width direction. Sample 6, Sample 7, Sample 8 and Sample 9, each centered at a point of 40 cm from the center in the width direction toward both ends in the film width direction, respectively, from the center in the width direction toward both ends in the film width direction Measurement was performed using 11 samples of sample 10 and sample 11 centered on a 50 cm point, and the value of sample 1 was Central portion of the thickness of the sample 10, the value of the sample 11 to a value at both end portions in the width direction.)
(4) b ^* value of transmitted light of C65 light In the film width direction, the sample is cut out at a size of 5 cm in the width direction × 5 cm in the longitudinal direction at intervals of 10 cm toward the center in the film width direction and then to both ends in the film width direction. The b ^* value was measured using a spectrocolorimeter (Konica Minolta Sensing Co., Ltd., CM-3600d). (For example, in the case of a film having a film width of 1100 mm, sample 1 is centered in the center in the film width direction, and each point of 10 cm is centered from the center in the width direction toward both ends in the width direction in the film width direction. Sample 2, Sample 3, Sample 4 and Sample 5, each centered at a point of 20 cm from the center in the width direction to both ends in the film width direction, each 30 cm from the center in the width direction to both ends in the film width direction Samples 6 and 7 centered at the point No. 8 and Samples 9 centered at points 40 cm from the center in the width direction toward both ends of the film, and both ends in the film width direction from the center in the width direction Measurement was carried out using 11 samples, sample 10 and sample 11, each centered at a point of 50 cm. The maximum value of the b ^* value maximum value in the width direction of the b ^* value of Le, the minimum value of 11 one b ^* value the minimum value in the width direction of the b ^* values of the samples, the 11 one sample b ^* (The average value is the average value of b ^* values in the width direction.)
As a means of measurement, the zero configuration of the reflectance was performed in the zero configuration box attached to the spectrocolorimeter, and then 100% calibration was performed using the attached white calibration plate, and then measured under the following conditions. .
Mode: Transmission measurement diameter: 8mm
Light source: C65 (normal incidence)
(5) Refractive index of thermoplastic resins A and B Measured according to JIS K7142 (1996) A method.

(6) Heat of fusion of thermoplastic resins A and B A sample mass of 5 g is taken from the thermoplastic resins A and B, and a differential scanning calorimeter (DSC) is used with a robot DSC-RDC220 manufactured by Seiko Electronics Industry Co., Ltd. It was measured and calculated according to K-7122 (1987). In the measurement, the temperature was raised from 25 ° C. to 290 ° C. at 5 ° C./min, and the integral value from the baseline in the range of melting point ± 20 ° C. at this time was defined as the heat of fusion. In addition, the melting point here is the point where the difference from the baseline of DSC is maximized. Here, a resin having a heat of fusion of 20 J / g or more is a crystalline resin, and a resin having a heat of fusion of 5 J / g or less is an amorphous resin.

(7) Average transmittance at a wavelength of 380 nm to 780 nm / Average reflectance measurement at a wavelength of 850 nm to 1200 nm A sample was cut out at a size of 5 cm × 5 cm from the center in the film width direction. Subsequently, the transmittance | permeability and reflectance in incident angle (PHI) = 0 degree were measured using the spectrophotometer (Hitachi Ltd. make, U-4100 Spectrophotometer). The inner wall of the attached integrating sphere is barium sulfate, and the standard plate is aluminum oxide. The measurement wavelength was 250 to 2600 nm, the slit was 2 nm (visible) / automatic control (infrared), the gain was set to 2, and the measurement was performed at a scanning speed of 600 nm / min. Next, average transmittance and average reflectance at wavelengths of 380 nm to 780 nm and wavelengths of 850 nm to 1200 nm were calculated. The average transmittance and average reflectance are calculated by calculating the area surrounded by the waveform curve and wavelength band based on the Simpson method formula using the transmittance and reflectance data for each wavelength of 1 nm, and the width of the wavelength band. Then, the average transmittance and the average reflectance were obtained. A detailed explanation of the Simpson method is described in “Numerical calculation method I for electronic computers” (Baifukan) (1965) by Jiro Yamauchi et al.

(8) Method of calculating the total value of the product of the reflectance (%) at each wavelength (5 nm interval) at 380 nm to 550 nm and the stimulus value at each wavelength (5 nm interval) from 380 nm to 550 nm in the color matching function The sample was cut out at a size of 5 cm × 5 cm at intervals of 10 cm. Next, the reflectance at an incident angle Φ = 0 ° was measured using a spectrophotometer (manufactured by Hitachi, Ltd., U-4100 Spectrophotometer). Measurement conditions: The slit was 2 nm (visible) / automatic control (infrared), the gain was set to 2, and the scanning speed was 600 nm / min. From these results, the reflectance (%) at each wavelength (5 nm interval) at wavelengths of 380 nm to 550 nm was determined. In addition, the value described in JIS Z 8701 was used as the stimulus value for each wavelength (5 nm interval) of 380 nm to 550 nm in the color matching function.

The total value of the product of the reflectance (%) of each wavelength (5 nm interval) at 380 nm to 550 nm in each width of the film and the stimulation value of each wavelength (5 nm interval) from 380 nm to 550 nm in the color matching function was calculated.
Here, an example of a method for calculating the total value of the product of the reflectance (%) of each wavelength (5 nm interval) at 380 nm to 550 nm and the stimulus value of each wavelength (5 nm interval) of 380 nm to 550 nm in the color matching function It is described in Table 1.

The total value of the products of the reflectance (%) of each wavelength (5 nm interval) at 380 nm to 550 nm and the stimulus value of each wavelength (5 nm interval) of 380 nm to 550 nm in the color matching function is “233.91”.

(Coating layer composition C1)
-Aqueous dispersion of acrylic / urethane copolymer resin (a): Sannaron WG658 (solid content concentration 30% by weight), manufactured by Sannan Synthetic Chemical Co., Ltd.
-Aqueous dispersion of isocyanate compound (b): Elastron E-37 (solid content concentration: 28% by weight) manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
-Aqueous dispersion of epoxy compound (c): manufactured by DIC Corporation, CR-5L (solid content concentration: 100% by weight)
An aqueous dispersion of the composition (d) comprising a compound having a polythiophene structure and a compound having an anion structure (solid content concentration: 1.3% by weight)
-Aqueous dispersion of oxazoline compound (e): Nippon Shokubai Co., Ltd., Epocross WS-500 (solid content concentration 40% by weight)
-Aqueous dispersion of carbodiimide compound (f): Nisshinbo Co., Ltd., Carbodilite V-04 (solid content concentration 40%)
-Silica particles (g): JGC Catalysts & Chemicals, Spherica slurry 140 (solid content 40%)
-Acetylene diol-based surfactant (h): manufactured by Nissin Chemical Co., Ltd., Olfine EXP4051 (solid content concentration 50%)
-Aqueous solvent (i): pure water The above-mentioned (a) to (h) in terms of solid weight ratio (a) / (b) / (c) / (d) / (e) / (f) / ( g) / (h) = 100/100/75/25/60/60/10/15 and mixed so that the solid content concentration of the aqueous coating material is 3% by weight. Mix and adjust the concentration.

(Composition C2 of coating layer)
-Aqueous dispersion of acrylic / urethane copolymer resin (a): Sannaron WG658 (solid content concentration 30% by weight), manufactured by Sannan Synthetic Chemical Co., Ltd.
-Aqueous dispersion of isocyanate compound (b): Elastron E-37 (solid content concentration: 28% by weight) manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
-Aqueous dispersion of epoxy compound (c): manufactured by DIC Corporation, CR-5L (solid content concentration: 100% by weight)
An aqueous dispersion of the composition (d) comprising a compound having a polythiophene structure and a compound having an anion structure (solid content concentration: 1.3% by weight)
-Aqueous dispersion of oxazoline compound (e): Nippon Shokubai Co., Ltd., Epocross WS-500 (solid content concentration 40% by weight)
-Aqueous dispersion of carbodiimide compound (f): Nisshinbo Co., Ltd., Carbodilite V-04 (solid content concentration 40%)
-Silica particles (g): JGC Catalysts & Chemicals, Spherica slurry 140 (solid content 40%)
-Acetylene diol-based surfactant (h): manufactured by Nissin Chemical Co., Ltd., Olfine EXP4051 (solid content concentration 50%)
-Yellow pigment (i): manufactured by Dainichi Seika Co., Ltd., NAF1012 yellow (solid content: 40% by weight)
-Aqueous solvent (j): pure water The above-mentioned (a) to (h) in terms of solid weight ratio (a) / (b) / (c) / (d) / (e) / (f) / ( g) / (h) / (i) = 100/100/75/25/60/60/10/15/5, and the solid content concentration of the aqueous coating composition is 3% by weight. (J) was mixed so that the concentration was adjusted.

Example 1
As two types of thermoplastic resins having different optical properties, thermoplastic resin A is polyethylene terephthalate having an intrinsic viscosity of 0.65 and a melting point of 255 ° C. (hereinafter also referred to as PET, the refractive index of the film after stretching and heat treatment is about 1. 66) A copolymer of polyethylene terephthalate having an intrinsic viscosity of 0.72 and amorphous (using 20% by mole of spiroglycol component and 5% by mole of butylene glycol component) using [Toray F20S], hereinafter referred to as SPG copolymerization. (Also referred to as PET (refractive index 1.549)) was used.

  The thermoplastic resin A and the thermoplastic resin B thus prepared were each melted at 280 ° C. with a vented twin-screw extruder and then fed into a 401-layer feed block via a gear pump and a filter. Merged. Both the surface layer portions were made of the thermoplastic resin A, and the layer thicknesses of the layer A made of the thermoplastic resin A and the layer B made of the thermoplastic resin B were made substantially the same. Next, after joining the 401-layer feed block, the die die bolt is mechanically and thermally operated, and the die lip interval is adjusted so that the sheet thickness at the center is thicker than the end, and then led to the die. After forming into a sheet shape, it was rapidly cooled and solidified on a casting drum maintained at a surface temperature of 25 ° C. by applying an electrostatic force to obtain a cast film. The discharge amount was adjusted so that the weight ratio of the thermoplastic resin A and the thermoplastic resin B was about 1, and the thickness ratio of adjacent layers was about 1.

  The obtained cast film was heated with a group of rolls set at 75 ° C., and then stretched 3.5 times in the longitudinal direction while rapidly heating from both sides of the film with a radiation heater between 100 mm stretch length. Cooled down. The film temperature during stretching was 90 ° C. Subsequently, corona discharge treatment was applied to both surfaces of the uniaxially stretched film in air, the wetting tension of the base film was set to 55 mN / m, and the composition of the coating layer C-1 was formed on one surface of the film on the treated surface. The thickness was adjusted and applied so that the thickness of the coating layer having a thickness in the center in the width direction was 50 nm in the final film.

  This uniaxially stretched film was guided to a tenter, preheated with hot air at 100 ° C., and then stretched 3.8 times in the transverse direction at a temperature of 110 ° C. The stretched film is directly heat-treated with hot air at 230 ° C. in a tenter, subsequently subjected to a relaxation treatment of 3% in the width direction at the same temperature, and then gradually cooled to room temperature, so that the film width becomes 1100 mm. In this way, it was wound up. The thickness of the obtained film width direction center part was 78 micrometers. The results of the obtained film are shown in Tables 2 and 3.

(Example 2)
The film was formed in the same manner as in Example 1 except that the die die bolt was mechanically and thermally operated, and the base lip interval was adjusted so that the sheet thickness at the center in the width direction was thicker than that in Example 1. Obtained. The thickness of the obtained film width direction center part was 78 micrometers. The results are shown in Tables 2 and 3.

(Example 3)
The film was formed in the same manner as in Example 2 except that the die die bolt was mechanically and thermally operated, and the base lip interval was adjusted so that the sheet thickness at the center in the width direction was thicker than that in Example 2. Obtained and wound up to a film width of 1500 mm. The thickness of the obtained film width direction center part was 78 micrometers. The results are shown in Tables 2 and 3.

Example 4
The die die bolt is mechanically and thermally operated, and the die lip interval is adjusted so that the sheet thickness at the central portion in the width direction is thicker than that in Example 3, and the composition of the coating layer C-2 is prepared. Except for applying the thickness adjustment so that the thickness of the coating layer at the end of the film is 100 nm on the final film so that the thickness of the coating layer at the center thickness of the film is 50 nm in the final film on one side of the film, A film was obtained in the same manner as in Example 3, and wound up so as to have a film width of 1500 mm. The thickness of the obtained film width direction center part was 78 micrometers. The results are shown in Tables 2 and 3.

(Example 5)
The die die bolt is operated mechanically and thermally, and the die lip interval is adjusted so that the sheet thickness at the central portion in the width direction is thicker than that in Example 4, and the composition of the coating layer C-2 is prepared. Except for coating on one side of the film, the thickness of the coating layer at the center of the film is 50 nm in the final film, and the thickness is adjusted so that the thickness of the coating layer at the end of the film is 100 nm in the final film. A film was obtained in the same manner as in Example 4 and wound up so as to have a film width of 2000 mm. The thickness of the obtained film width direction center part was 78 micrometers. The results are shown in Tables 2 and 3.

(Example 6)
The die die bolt is operated mechanically and thermally, and the die lip interval is adjusted so that the sheet thickness at the central portion in the width direction is thicker than that in Example 5, and the composition of the coating layer C-2 is prepared. Except for coating on one side of the film, adjusting the thickness so that the thickness of the coating layer at the end of the film is 100 nm in the final film, so that the thickness of the coating layer in the center in the film width direction is 50 nm in the final film Obtained the film similarly to Example 5, and wound up so that it might become a film width of 2000 mm. The thickness of the obtained film width direction center part was 78 micrometers. The results are shown in Tables 2 and 3.

(Example 7)
The die die bolt is mechanically and thermally operated, and the die lip interval is adjusted so that the sheet thickness at the central portion in the width direction is thicker than that in Example 6, and only the film edge portion is exposed from both sides of the film. A film was obtained in the same manner as in Example 6 except that the film temperature at the end of the film was adjusted to 95 ° C. by increasing the output, and the film was wound up so as to have a film width of 2000 mm. The thickness of the obtained film width direction center part was 78 micrometers. The results are shown in Tables 2 and 3.

(Example 8)
The die die bolt is mechanically and thermally operated, and the base lip interval is adjusted so that the sheet thickness at the central portion in the width direction is thicker than that in Example 7, and only the film end portion is exposed from both sides of the film. A film was obtained in the same manner as in Example 6 except that the film temperature at the end of the film was adjusted to 100 ° C. by increasing the output, and the film was wound up so as to have a film width of 2000 mm. The thickness of the obtained film width direction center part was 78 micrometers. The results are shown in Tables 2 and 3.

(Comparative Example 1)
A film was obtained in the same manner as in Example 1 except that the base lip interval was adjusted so that the sheet thickness and the end of the central portion in the width direction were uniform, and the film was wound so as to have a film width of 1100 mm. The thickness of the obtained film width direction center part was 78 micrometers. The results are shown in Tables 2 and 3.

(Comparative Example 2)
A film was obtained in the same manner as in Example 1 except that the base lip interval was adjusted so that the sheet thickness and the end of the central portion in the width direction were uniform, and the film was wound so as to have a film width of 1500 mm. The thickness of the obtained film width direction center part was 78 micrometers. The results are shown in Tables 2 and 3.

(Comparative Example 3)
A film was obtained in the same manner as in Example 1 except that the base lip interval was adjusted so that the sheet thickness and the end of the central portion in the width direction were uniform, and the film was wound up so as to have a film width of 2000 mm. The thickness of the obtained film width direction center part was 78 micrometers. The results are shown in Tables 2 and 3.

  The present invention relates to a heat ray reflective film capable of cutting heat rays caused by sunlight or the like. More specifically, the present invention relates to a heat ray reflective film that can reflect heat rays with high efficiency while maintaining the transparency of transmitted light, and has little variation in color in the film width direction, and is suitable as a large-sized glass application in trains, buildings, etc. It is a thing.

Claims (5)

A film having a film width of 1000 mm or more, the difference between the maximum and minimum b ^* values in the width direction is 0.5 or less, the average transmittance at wavelengths of 380 nm to 780 nm is 50% or more, and the wavelength A film having an average reflectance of 850 nm to 1200 nm of 60% or more. The film according to claim 1, wherein the difference between the maximum value and the minimum value of the thickness at the center portion in the width direction and the end portion in the width direction is 0.5 μm or more and 5.0 μm or less. The film of Claim 1 or 2 whose average value of b ^* value of the width direction is 3 or less. The film according to claim 1, which is a laminated film having 50 or more layers. The film in any one of Claims 1-4 used in combination with glass.

Images